Title of Invention	NOVEL INTERFERENCE PIGMENTS AND PROCESS FOR THEIR PREPARATION
Abstract	The present invention relates to a pigment, the particles of which generally have a length of from 2 J.!m to 5 mm, a width of from 2 J.!m to 2 mm, and a thickness of from 20 nm to 2 J.!m, and a ratio of length to thickness of at least 2: 1, characterized in that the particles contain a core of SiOy with 1.1 y 1.95, especially 1.1 y 1.8, having two substantially parallel faces, the distance between which is the shortest axis of the core, comprising (a) a layer of a metal oxide having a high index of refraction; (b) optionally a metal oxide of low refractive index, wherein the difference of the refractive indices is at least 0.1. (c) optionally a layer of a metal oxide having a high index of refraction; and (d) optionally an outer protective layer; or (b) a thin semi-transparent metal layer, or (b) a layer of a metal having a thickness of> 25 nm to 100 nm, preferably 30 to 50 nm.

Title of Invention

NOVEL INTERFERENCE PIGMENTS AND PROCESS FOR THEIR PREPARATION

Abstract

The present invention relates to a pigment, the particles of which generally have a length of from 2 J.!m to 5 mm, a width of from 2 J.!m to 2 mm, and a thickness of from 20 nm to 2 J.!m, and a ratio of length to thickness of at least 2: 1, characterized in that the particles contain a core of SiOy with 1.1 y 1.95, especially 1.1 y 1.8, having two substantially parallel faces, the distance between which is the shortest axis of the core, comprising (a) a layer of a metal oxide having a high index of refraction; (b) optionally a metal oxide of low refractive index, wherein the difference of the refractive indices is at least 0.1. (c) optionally a layer of a metal oxide having a high index of refraction; and (d) optionally an outer protective layer; or (b) a thin semi-transparent metal layer, or (b) a layer of a metal having a thickness of> 25 nm to 100 nm, preferably 30 to 50 nm.

Full Text	Interference pigments on the basis of silicon oxides The present invention relate: to (interference) pigments having a core of SiOy with 0.70 plastics, cosmetics, giazes fo" ceramics and glass. Interference pigments having a core of Si02 are known (Gerhard Pfaff and Peter Reynders, Chem. Rev. 99 (1999) 1963-1981): The Si02 flakes are produced, for example, by a process described in WO93/08237, wherein a sodium water glass solution is applied as a thin film on an endless band, solidified and dried. WO93/08237 also describes the coating of the Si02 flakes with a metal oxide having a high index of refraction or a tnin semi-transparent metal layer. W098/53011 discloses multi-coated interference pigments consisting of a transparent carrier material which is coated with alternating metal oxide layers with a high and low refractive index, wherein the difference between the respective refractive indexes is 0.1. The metal oxide layers are obtained in a wet process by hydrolysis of the corresponding water-soluble metal compounds, by separating, drying and optionally calcinating the pigment thus obtained. WO01/57257 Describes a orocess comprising the production of a substrate material, for example, silicon oxide, by physical vapor deposition and the wet chemical coating of the obtained fiakes with, for exanoie, Ti02. According to Example 4 of WO01/57287 silicon cxiae fiakes having a thickness of 200 nm and a particle size of 1 to 100 ^m are obtained by ?VD and then coatee by a wet chemical process with Ti02. EF-A-8Q35-S discloses coloured pigments containing (a) a core consisting of an essentially transparent o: metallic reflecting material, and (b) at least a coating consisting essentially of one or more silicone oxides, the moiar ratio of oxygen to a silicon being 0.25 to 0.95; it is the object of the present invention to provide interference pigments, having higher color strength and color purity as compared with interference pigments known from the state of the Said object has been soivecd by pigments, the particles of which generally have a length of from 2 μm to 5 mm, a width of from 2 \|μm to 2 mm, and a thickness of from 20 nm to 2 μm, and a ratio of length to thickness of at least 2:1, wherein the particles contain a core of SiOy with 0.70 Tne term "SiC. with C.7C ≤ \ ≤ 1.95" means that the molar ratio of oxygen to silicon at the average value of the silicon oxide layer is from 0.70 to 1.95. The composition of the silicon oxide layer can be determined by ESCA (electron spectroscopy for chemical analysis). According t: the presen; indention the term "aluminum" comprises aluminum and alloys of aluminum. Alloys of aiuminum are, for example described in G. Wassermann in Ullmanns Enzykiopadie der tocustrieiier Cnemie, 4. Auflage, Verlag Chernie, Weinheim, Band 7, S. 2£1 to 292. Especially suitaoie are the corrosion stable aluminum alloys described on page 1C to "12 of WO00/12SS4. wnich comprise besides" o'f aluminum silicon, magnesium, manganese, copper, zinc, nick©;, vanadium, lead, antimony, tin, cadmium, bismuth, titanium, Chromium and/or iron in amounts of less than 20 % by weight, preferably less than 10 % by weight. Suitable metals for the sem:-t:ansparent metal layer are, for example. Cr: Ti, Mc, W, A!, Cu, Ac. Au, or J\;. The $emi-:ra~;sparen: metal layer has typically a thickness of between 5 and 25 nm. especiai'y between 5 and 1c nm. The SiOy substrates can have a metal layer only on one paraiie' surface, but prefsraoiv the metal layer is present on both parallel faces of the suostrate. The metal/SiOy/metal flakes are prepared by a PVD process comprising the steps: a) vapour-deposition of a separating agent onto a (movable) carrier to produce a separating agent layer, b) vapour-deposition of a metal layer onto the separating agent layer, c) vapour-deposition of an SiCy layer onto the metal layer, wherein 0.70 £ y £ 1.80, d) vapour-deposition of a metal layer onto the SiOy layer, e) dissolution of the separating agent layer in a solvent, and 0 separation of the metal'SiGyme-ia!-flakes from the solvent. Alternatively the metal layer can be obtained by wet chemical coating or by chemical vapor deposition, to: example, gas pnase deposition of metal carbonyls. The substrate is suspended in an aqueous and'or organic solvent containing medium in the presence of a metal compound and is deposited onto the substrate by addition of a reducing agent. The metal compound is, for examplel, silver nitrate or nickel acetyl acetonate (WO03/37993). According to US-5-3,536,520 nickel chloride can be used as metal compound and hypophosphite can be used as reducing agent. According to EP-A-353544 the following compounds can be used as reducing agents for the wet chemical coating: aldehydes (formaldehyde, acetaldehyde: oenzalaldehyde), ketones (acetone), carbonic acids and salts thereof (tar:aric acid, ascorbinic acid), reductones (isoascorbinic acid, triosereductone, reductine acid}, and reducing sugars (glucose). If semi-transparent metal layers are desired, the thickness of the metal layer is generally between 5 anc 25 nm, especially between 5 and 15 nm. If pigments witr metallic appearance are desired, the thickness of the metal layer is > 25 nm tc IOC nm, preferably 30 tc 50 nm. If pigments with colored metal effects are desired, aoditionai layers of colored or colorless metal oxides, metal nitrides, metai suldfides and/or metais ca~ oe deposited, ~~hese layers are transparent or semi-transparent, it is preferred tr.a: iaye-s :" nigr index o* refraction and layers of low index of refraction alternate or that :ne layer := present, whereir- within the layer the index of refraction is gradually changing. It is possible 'or the weatherinc resistance to be increased by means of an additional coating, which at the same time causes an optima! adaption to the binder system (EP-A-268918 and EP-A-632109r, one pre;e~ec emoodirnen: of tne present invention, the interference pigments comprise materials ha,ving "nign1 inae> o; redaction, which is defined herein as an index o£ refraction of greater man about 1.65, and optionally materials having a "low" index of refraction, which is defined herein as an index of refraction of about 1.65 or less. Various (dielectric) materials that can be utilized including inorganic materials such as metal oxides, metal suboxides, rnetai fluorides, metal oxyhahces, metal sulfides, metal chaicogenides, metal nitrides, metal oxynitrides, metal carbides, combinations thereof, and the like, as well as organic dielectric materials. These materials are readily available and easily applied by physical, or chemical vapor deposition processes, o' ry wet chemical coating processes. - - in an especially preferred emdociment, the interference pigments on the basis of the silicon oxide substrate comprises a further lc/e* of a dielectric material having a "high" refractive index, that is to say a refractive index greate' than about 1.65, preferably greater than about 2.0, most preferred greater than about 2.2. which is applied to the entire surface of the silicon/silicon oxide substrate. Examples of such a dielectric material are zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (Zr02), titaniur dioxide (Ti02), carbon, indium oxide (ln203), indium tin oxide (ITO), tantalum pentoxide (Ta2O2;, chromium oxide (Cr203), cerium oxide (Ce02), yttrium oxide (Y203)( europium oxide (Eu203;, iron oxides such as iron(ll)/iron(lll) oxide (Fe304) and iron(lll) oxide (Fe2C3); hafnium nitride HfN), hafnium carbide (HfC), hafnium oxide (Hf02), lanthanum oxide (La202), magnesium oxide (MgO), neodymium oxide (Nd203), praseodymium oxide (Pr6Or), samarium oxide (Sm2C5;. antimony trioxide (Sb203), silicon monoxides (SiO), selenium1 trioxide (Se2O3).. tin oxide (3nC2i. tungsten trioxide (W03) or combinations thereof. The dielectric material is preferably a metai oxioe. It being possible for the metal oxide to be a single oxide or a mixture of cxces. witr. or without absorbing properties, for example, Ti02l Zr02l Fe203) Fe^O, C^npz or Z.nC witn ~I02 being esoeciaily preferred. It is possible to obtain pigments that are more intense in colour and more transparent by applying, or to: o; the TiO^ laye', a metai oxide of low refractive index, such as Si02i Al^Os, AlOOK, B23: or 5 mixture thereof, preferably Si02, and optionally applying a further Ti02 iayer on tor of the latter lave- EF-A-892832, EP-A-753545, WO93/08237, W098/53C"-. W036-225S. W09S3E25^. WD99/20695, WOOO/42111, and EP-A-1213330). Nonlimitinc examples c suitable iovv index dielectric materials that can be usee include silicon dioxide (SiO:), aluminum oxide ;AI2G3 . and meta! fluorides such as magnesium fluoride (MgF2!, aluminum f;uoride (AIF3): cerium ^joride (CeF3), lanthanum fluoride (LaF3), sodium aluminum fluorides (e.g., Na3AiF€ or Na2A6-, neodymium fluoride (NdF3), samarium fluoride (SmF3;., barium! fiuo:ae (BsF2). calcium fluoride (CaF2), lithium fluoride (LiF), combinations thereof, or any otner ;cv index materia! having an index of refraction of about 1.65 or less. For example, organic monomers anc polymer can be utilized as low index.materials, including dienes or alkenes such as acrylates (e.g., methacrylate), polymers of perfluoroalkenes, polytetrafluoroethylene (TEFLON), polymers of fluorinated ethylene propylene (FEP), parylene, p-xylene, combinations thereof, and the like. Additionally, the foregoing materials include evaporated, condenses and cross-linked transparent acrylate layers, which may be Deposited by methods described in U.S. Pat. No. 5,877,895, the disclosure of which is incorporatec herein by reference. Accoraingly, preferred interference pigments comprise besides (a) a metal oxide of high 'efractlve index in addition and 't, a metal oxide of low refractive index, wherein the difference o' the tractive indices is a: leas: C\1. Pigments on the basis of silicon oxide (SiOy) substrates, which have been coated by a wet chemical methoc, in the indicated order are particularly preferred: ~iO; (substrate: silicon oxide: iayer: Ti02, preferably in the rutile modification), (Sn02)Ti02, Fe203. Fe3C4l TiFe205, Cr203l Zr02, Sn{Sb)02, BiOCI, Al203f Ce2S3, MoS2( Fe203Ti02 i substrate: silicon oxide; mixec iayer of Fe203 and Ti02), TiO^Fe^ (substrate: silicon oxide; firs: iayer: TiC2: second layer: Fe203), Ti02/Berlin blau, TiOa/Cr203lorTi02/FeTi03. In genera! the iayer thickness ranges from : to 1000 nm, preferably from 1 to 300 nm. in anotner panicuiariy preferred embodiment the present invention relates to interference olgmsnts containing at ieas: tnree alternating layers of high and low refractive index, such as, for exampie. TiCySiCg/TjC^ 'SnG^TiCySiCVTiCk TiOa/SiOa/TiCVSKVTiOz or Ti02/Si02/Fe203: ^eferaby tn~ lave- structure is as TOIIOWS: .-.. a coating navng a refractive mosx > 1.65, ■5 a coating navng a refractive inoex 1,65, and 'D; ootional!} an outer protective iayen ~v: tnicKness c' tne ndivbua; ;svers of hiah and low refractive index on the base substrate is essentia to- :~e ootioa! ore-Denies of tne pigment. The thickness of the individual layers, especially me:a oxide ieyers: depends on the field of use and is generally 10 to 1000 nm, oreferabiv 15 :: S00 nm. In oartbuia 20 to 600 nm. The thicKness o: iayer (A) is : 0 :o 55C nm, preferably 15 to 400 nm and, in particular, 20 to 350 nm. Tne thickness o* iayer ;3 is IC ;c '000 nm, preferably 20 to 800 nm and, in particular. 30 to 50: nm. ~ne :- .coess o: is ye" \Z is ' l to 550 nm, preferably 15 to 400 nm and, in particular, 20 to 350 nm. Particularly suitable materials for iayer (A) are metal oxides, metal sulfides, or metal oxide mixtures, such as Ti02) Fe2C,. 7iFe205, Fe304, BiOCl, CoO, C03O4, Cr203, V02, V203, 3n(Sb)02l SnG2l Zr02l iron titanates, iron oxide hydrates, titanium suboxides (reduced titanium species having oxicatic- states from 2 to Particularly suitable materials ~or iayer (B) are metal oxides or the corresponding oxide hydrates, such as Si02) MgF: A;s03, AIOOH, B203 or a mixture thereof, preferably Si02. Particularly suitable materials for iayer (C) are colorless or colored metal oxides, such as Ti02, Fe203 TiFe205! Fe30, BiOC . OoC, Co304, Cr203, V02, V203, Sn(Sb)02, Sn02, Zr02, iron titanates, iron oxide hydrates Titanium suboxides (reduced titanium species having oxidation states from 2 to intenayers c absorbing or nonaoso-oinc materials can be present between layers (A), (3), (C and \D). The thickness 0** tne r.ieriayers is 1 to 50 nm, preferably 1 to 40 nrr. and, in particular, 1 -^ %r nrr, The pigments of the present invention are characterized by the precisely defined thickness and smooth surface of the thir. SiCv flakes. The metal oxide layers can be applied by CVD (chemical vapour deposition) or by wet chemical coaling. Tne metai oxide layers can be obtained by decomposition of metal carbonyis in tne presence of water vapour (relatively low molecular weight metal oxides SUCH as magnetite"' or r, the presence of oxygen and, where appropriate, water vapour (e.g. nickel oxide and cooait oxide}. The metal oxide layers are especially applied by means of oxidative gaseous ohase decomposition of meta! carbonyls (e.g. iron pentacarbonyl, chromium: nexacaroony:: Er-A-45 85".). by means of hydrolytic gaseous phase decomposition of metal ascohoiates e o. titanium and zirconium tetra-n- and -iso-propanolate; DE-A-41 40 900) c o* meta' haiioe^ e.c. titanium tetraohioride; EP-A-338 428), by means o* oxidative decomposition y croany; tin compounds (especially alky! tin compounds such as tetrabutyftir and tetrametny!;;-, DE-A-44 Zc £78, or by means of the gaseous phase hydrolysis of organy silicon compound (especially C:-ten-butoxyacetoxysiIane) described in EP-A-668 329, it oeinc oossbie fc tne coating ooeration to be carried out in a fluidisec-Dec reactor :'EP-A-04£ Eft ano EF-A-105 235\ Ai2Os layers (B) can advantageous1)' be obtained by conrolied ox^oaTiO" curing tne cool;':: of aluminium-coated pigments, which is otherwise cameo out -nae- met gas (DE-A--. ?5 16 161). Pnosphate-. cremate- and'b' vanac'ate-containing and also phosphate- and SiOj-containin: meta1 oxide ;avers can be aooiieo r accordance with the passivation methoos described r DE-A-42 3r 332 and \r EP-A-S7E 561 by means of hydrolytic or oxidative gaseous phase decomposition o" cxide-nalides o* tne metais (e.g. CrC2C\2. VOCi3), especially of phosphorus cxynaiices ,e.c PCC^;. phosphoric and phosphorous acid esters (e.g. df- ano tri-metnyi ano di- and tri-etny! phosphite) and of amino-group-containing organyl silicon compounds (e.g. 3-aminopropyi-triethoxy- and -trimethoxy-silane). Levers of oxides of the metais zirconium, titanium, iron and zinc, oxide hydrates of those metals, iron titanates, titanium suboxides or mixtures thereof are preferably applied by precipitation by a wet chemical method, it Deing possible, where appropriate, for the metal oxides to be reduced. In the case of the wet chemical coating, the wet chemical coating methods developed for the -production o\ peariescent pigments may be used; these are described, for example, in DE-A-14 67 458, DE-A-19 5S 988, DE-A-20 09 566, DE-A-22 14 545, DE-A-22 15 191, DE-A-22 44 298: DE-A-2S rf2 331, DE-A-25 22 572, DE-A-31 37 808, DE-A-31 37 809, DE-A-31 51 343, DE-A-31 51 354, DE-A-31 51 355, DE-A-32 11602 and DE-A-32 35 017, DE 195 99 88. WO 93/08237, WO 98/53001 and WO03/6558. The metal oxide of high refractive index is preferably Ti02 and/or iron oxide, and the metal oxide of low refractive index is preferably Si02. Layers of T1O2 can be in the rutile or anastase modification, wherein the rutile modification is preferred. Ti02 layers can also be reduced by known means, for example ammonia, hydrogen, hydrocarbon vapor or mixtures thereof, or metal powders, as described in EP-A-735,114, DE-A-3433657, DE-A-4125134, EP-A-332071, EP-A-707,050 or W093'19131. "or the purpose of coating, tne substrate particles are suspended in water and one or more hydrolysabie metal salts are aooec at a pH suitable for the hydrolysis, which is so selected that tne metal oxides or "metal cxiae nydrates are precipitated directly onto the particles without subsidiary precipitation, occurring. Tne pH is usually kept constant by simultaneously metering in a base. The pigments are tner separated off, washed, dried and, where appropriate, calcinated, it being possible tc optimise tne calcinating temperature with respect to the coating in question. If desired, after individual coatings nave been applied, the pigments can be separated off, dried and, wnere appropnate, calcinate! and then again re-suspended for the purpose of precipitating turner levers. Tne metai cxibe layers are a:sc obtainable, for example, in analogy to a methoc described in DE-A-195 C 307, by producing the metal oxide layer by controlled hydrolysis of one or more metai acic esters, where appropriate in the presence of an organic solvent and a basic catalyst, b\. means 0' a so-ge process. Suitable basic catalysts are, for example, amines, such as thethyiamine, e:~yienediamine, tributylamine, dimethylethanolamine and methcxy-prooylamine Tne prganic so'ven* T a water-miscible organic solvent such as a C^aicoho!. especially isopropanol. Suitable metal acid esters are selected from alkyl and aryl alcoholates, carboxylates, and carboxyl-radicai- or alkyl-radicai- or aryl-radical-substituted alkyl alcoholates or carboxylates of vanadium, titanium, zirconium, silicon, aluminium and boron. The use of triisopropyi aluminate, teuaisopropy! titanate, tetraisopropyl zirconate, tetraethyl orthosilicate and triethy1 borate is preferred. In addition, acetylacetonates and acetoacetylacetonates of the aforementioned metals may be used. Preferred examples of that type of metal acid ester are zirconium acetylacetonate, aluminium acetylacetonate, titanium acetylacetonate and diisobutyloleyl acetoacetylaiuminate or diisopropyloleyl acetoacetylacetonate and mixtures of metal acid esters, for example Dynasi® (Huls), a mixed aluminium/silicon metal acid ester. As a metal oxide having a high refractive index, titanium dioxide is preferably used, the method described in US-B-3 552 001 being used, in accordance with an embodiment of the present invention, for application of the titanium dioxide layers. An aqueous titanium salt solution is slowly added to a suspension of the material being coated, whic~ suspension has-been heated to about 50-100°C, especially 70-80°C, and a substantially constant pH vaiue of about from 0.5 to 5, especially about from 1.2 to 2.5, is maintained Dy simultaneously metering in a base such as, for example, aqueous ammonia solution or aoueous alkali metal hydroxide solution. As soon as the desired layer thickness of precipitated "HO: nas been achieved, the addition of titanium salt solution and base is stopped. This metnoc a: so referred tc as the "titration method", is distinguished by the fact that an excess of titanium salt is avoided. That is achieved by feeding in for hydrolysis, per unit time, only that amount whic~ is necessary for even coating with the hydrated Ti02 and which can be taken UP per unit time :: tie avaiiaoie surface of the particles being coated. In principle, the anatase form: of TiQ2 forms o- tne surface of tne starting pigment. By adding small amounts of Sn02, however, it is possible tc force the rutiie structure to be formed. For example, as described in WO 93/0823". tin dioxide can be deposited before titanium dioxide precipitation and the product coated with minium dioxioe can be calcined at from 800 to 900CC. The TiO: car optionally oe reoucec by usual procedures: US-B-4,948,631 (NH3, 750-850 °C -, W083. r" 3 (rv, > 9X °2, or DE-A-19843014 (solid reduction agent, such as, for example, silicon, > 600 °C). Where appropriate, an Si02 (protective) layer can be applied on top of the titanium dioxide layer, for which the following method may be used: A soda waterglass solution is metered in to a suspension of the materia! being coated, which suspension has been heated to about 50-100°C, especially 70-80cC. The.pH is maintained at from 4 to 10, preferably from 6.5 to £.5 by simultaneously adding 10 % hydrochloric acid. After addition of the waterglass solution, stirring is carried out for 30 minutes. It is possioie tc obtain pigments that are more intense in colour and more transparent by applying, or top of the Ti02 layer a metal oxide of "low" refractive index, that is to say a refractive index smalier than about 1.65, such as Si02, Ai203, AIOOH, B2O3 or a mixture thereof, preferably Si02, and applying a further Fe2C3 and/or Ti02 layer on top of the latter layer. Such multi-coated interference pigments comprising a silicon oxide substrate and alternating metal oxide layers of with high and low refractive index can be prepared in analogy to the processes described in WO9&'530-J and WO99/20695. It is, in addrJon. possible to modify the powder colour of the pigment by applying further layers such as, for example, coloured metal oxides or Berlin Blue, compounds of transition metals, e.g. Fe, Cu. Ni. Zz, Cn or organic compounds such as dyes or colour lakes. ir, addition, re pigmen; according to the invention can also be coated with poorly soluble, firmiy adhering, inorganic or organic coiourants. Preference is given to the use of colour lakes anc. especially, ajminiurr: colour iaKes. For that purpose an aluminium hydroxide layer is precipitate'. . whicr- is, in a second step, lakec by using a colour lake (DE-A-24 29 762 and DE 29 28 287). Furthermore tne piemen: according tc the invention may also have an additional coating witr complex sa!: elements, especially cyanoferrate complexes (EP-A-141 173 and DE-A-23 13 332;. ""0 enhance tne weatne- and iign: stability the muttiplayer silicon oxide flakes can be, depending c- the fieic 0' application, subjected to a surface treatment- Useful surface treatments £-£. for example, desonoed in DE-A-2215191, DE-A-3151354, DE-A-3235017, DE-A-333459S, DE-A-4C30727, EF-A-649886, WO97/29059, WO99/57204, and US-A-5;759,25£. Sad surraoe treatment night also facilitate the handling of the pigment, especially :ts incorporat c~ into va-ious aep:;oation media. The SiOy flakes are prepared by a process comprising the steps (WO03/68868): a) vapour-deposition o' a separating agent onto a (movable) carrier to produce a separating agent layer, b) vapour-deposition of an SiOy layer onto the separating agent layer, wherein 0.70 s y s 1.8, c; dissolution of the separating agent layer in a solvent, and - - d; separation of the SiO; frorr: tne solvent. SfOvWith y > 1.0 car- be obtained by evaporation of SiO in the presence of oxygen. Layers, which are essentially free of absorption, can be obtained, if the growing SiOy layer is irradiated with UV light during evaporation (DE-A-1621214). It is possible to obtain SiO-,.5 layers, which do not aosorb in the visible region and have a refractive index of 1.55 at 550 nm, by so-called "reactive evaporation" of SiO in a pure oxygen atmosphere (E. Ritter, J. Vac. Sci. Techno!. 3 (1966) 225). ~~he SiOy layer in stec b; being vapour-deposited from a vaporiser containing a charge comprising a mixture of S\ anc Si02) SiOy or a mixture thereof, the weight ratio of Si to Si02 being preferably in the range from 0.15:1 to 0.75:1, and especially containing a stoichiometric mixture of Si and Si02 or c vaporiser containing a charge comprising silicon monoxide containing silicon in a-, amount up to 20 % by weight (0.70 £ y "ne silicon ex oe .aye: r step :. is formed preferably from silicon monoxide vapour produced in tne vaporise- by reaction of £ mixture of Si and Si02 at temperatures of more than 1300cC. Tne vapour-cepcsition in steps i) and b) is carried out preferably under a vacuum of esoec;ai;v The separating agent vapour-deposited onto the carrier in step a) may be a lacquer (coating), a polymer, such as, for example, the (thermoplastic) polymers, in particular acryl- or styrene polymers or mixtures thereof, as described in US-B-6,398,999, an organic substance soluble in organic solvents or water and vaporisable in vacuo, such as anthracene, anthraquhone, acetamidophenol, acetylsalicylic acid, camphoric anhydride, benzimidazole, benzene-',2.4-tricarboxylic acid, biphenyl-2,2-dicarboxylic acid, bis(4-nydroxyphenyl)sulfone, dihyaroxyanthraquinone, hydantoin, 3-hydroxybenzoic acid, 8-hydroxyquinoline-5-suifonic acid monohydrate, 4-hydroxycoumarinf 7-hydroxycoumarin, 3-nydroxynaphthaiene-2-ca'bcr/iic acid, isophthalic acid, 4,4-methylene-bis-3-hydroxy-naphthalene-2-carboxylic ace naphthalene-1,8-dicarboxylic anhydride, phthalimide and its potassium salt, phenolphthafein, phenothiazine, saccharin and its salts, tetraphenylmethane, triphenylene, triphenylmethanoi or a mixture of at least two of those substances. The separating agent is preferably an inorganic salt soluble in water and vaporisable in vacuo (see, for example, DE 198 44 357), such as sodium chloride, potassium chloride, lithium chloride, sodium fluoride, potassium fluoride, lithium fluoride, calcium fluoride, sodium aluminium fluoride and disodium tetraborate. The movable carrier may consist of one or more discs, cylinders or other rotationally symmetrica: bodies, which rotate about an axis (cf. WO01/25500), and consists preferably of one or mo'e continuous metai belts with or without a polymeric coating or of one or more poiyimide or oolyethyiene terephthalate belts (US-B-6,270,840). Step d; may'comprise washino-out and subsequent filtration, sedimentation, centrifugation, decanting and'or evaporation. 7ne plane-parallel structures of SiOy may, however, also be frozen together with the soiven* in step d) and subsequently subjected to a process of freeze-dryinc. whereupon the soiven; is separated off as a result of sublimation below the triple Doint and the dry SiOy remains oehind in the form of individual plane-parallel structures. ~ns ihver/iic* re;ates aisc iz plane-parallel structures of SiOy that are obtainable by tnis method arc nave a thickness preferably in the range from 20 to 2000 nm, especially 20 tc 50C nm, mes: preferred 50 tc 350 nm. Except unce' an ultra-high vacuum, in technical vacuums of a few 10' Pa vaporised SiO always concenses as S»C\ wherein 1 On its further course, the beit-form carrier, which is closed to form a loop, runs through dynamic vacuum lock chambers of known mode of construction (cf. US-B-6,270,840) into a region of from 1 tc 5 x 1Q4 Pa pressure, preferably from 600 to 104 Pa pressure, and . especially from 10~ tc 5 x 1Cfc" Fa pressure, where it is immersed in a dissolution bath. The temperature of the solvent snouic be so selected that its vapour pressure is in the indicated pressure range. With mechanical assistance, the separating agent layer rapidly dissolves and the product layer breaks up into flakes, which are then present in the solvent in the form of a suspension. On its further course, the belt is dried and freed from any contaminants still adhering to it. It runs through a second group of dynamic vacuum lock chambers back into the vaporisation chamber, where the process of coating with separating agent and product iayer of SiO is repeated. The suspension ther. present in both cases, comprising product structures and solvent, and the separating agent dissolved therein, is then separated in a further operation in accordance with a known technique. For that purpose, the product structures are first concentrated in the liquid and rinsec severa! times with fresh solvent in order to wash out the dissolved separating agent. The product, in the form of a solid that is still wet, is then separated off by filtration, sedimentation, cemrifugation, decanting or evaporation. T.ne product ca^ the~ be brought to the desired particle size by means of ultrasound or by mechanical means using nigh-speed stirrers in a liquid medium, or after drying the fragments in an air-jet mil; having a rotary classifier, or means of grinding or air-sieving and delivered for further use. h t.ne productior' o the smcorvsiiicon oxide flakes, variants are possible: It Is possible tc arrange severa; separating agent and product vaporisers one after the other in the running direction of the be!', r the vaporisation zone. By that means there is obtained, with little additional outlay in terms of apparatus, a layer sequence of S + P + S + P, wherein £ is the separating agent iayer and P is the product layer. If the number of vaporisers is doubled anc t.ne belt soeec is iT)e same, twice the amount of product is obtained. Separating o~ tne piar»e-para!ie: structures after washing-out at atmospheric pressure can oe carried out under gentle conditions Dy freezing the suspension, which has been concentrated to a solids content of about 50 % and subjecting it in known manner to freeze-drying at about -1QCC anc 50 Pa pressure. The dry substance remains behind as product, which can be subjected tc the steps of further processing by means of coating or chemical conversion. instead of using a continuous celt, it is possible to produce the product by carrying out the steps o; vapour-depositior. o\ separating agent and SiO, of dissolution, and of drying the carrier, in an apparatus having a rotary body, in accordance with WO01/25500. The rotary body may oe one or T;O~£ discs a cylinder or any other rotationally symmetrica! body. The SiOy flakes may be cxitiisec using an oxygen-containing gas such as, for example, air at a temperature of at leas: 230°C, especially at above 400°C, preferably in the form of loose material, in a fluidised bee or by introduction into an oxidising flame, preferably at a temperature in the range from 500 to 1000°C, to form plane-parallel structures of SiOy {WO03/068868}. At present, i; can not be exciuded, that by heating TiCVSiOy particles at a temperature above £00 GC( especially 400 TC I 100°C, reduction of Ti02 by SiOy TiO£ + SiOy -> SiOy+t + Ti02^ andor disp-oportionatio" c' SiCy in Si02 and Si occurs. SiOv -r (y/y+a) SiOy+a + (1 - (y/y+a)) Si in this disproportion S'C,.-. f.akes are formed, containing (1 - (y/y+a)) Si, wherein 0.03 Tne fiakes of tne oresen: invention are not of a uniform shape. Nevertheless, for purposes of orevity, the fiakes wit: be referred to as having a "diameter." The SiOy flakes have a high Diane-para!ie::srr. anc a aefinec thickness in the range of ± 10 %, especially r 5 % o: the average thickness. The SiCv fiakes nave a thickness of from 20 to 2000 nm, especially from 2: ic 500 nm. most preferec 50 tc 350 nm. It is presently preferred that the diameter of the f.akes be in a oreferred range of about 1-50 nm with a mor^referred range of aboul 5-40 am. Thus, tne aspect ratio o' the fiakes of tne present invention is in a preferred range of about 2 to 3000 with a more preferee' range of about 14 to 800. If a TiOr layer is depositee as a materia o; nigh refractive index, the Ti02 layer has a thickness of 20 to 200 nm:. especially 20 to : 00 nm, anc mora especially 20 to 50 nm. Due to the smaller thickness distribution of the SiOy flakes as compared to commercially available Si02 flakes effect pigments having a higher color purity result. V. trie SiOy substrates of the present invention are used instead of mica flakes or Si02 substrates obtained according tc the process described in WO93/08237, interference pigments having superior brilliance, clear and intense colors, intense color flop, improved color strength and color purity can be obtained. - , in another preferred embodiment of the present invention the SiOy flakes have a thickness of from 20 tc 200 nm, especially from 40 to 150 nm, most preferred 60 to 120 nm. The SiCy fiakes have a high piane-paraiieiism and a defined thickness in the range of ± 30 %, especially = 10 % of the average thickness. It is presently preferred that the diameter of the flakes be in a preferred range of about 1 to 60 \xm, especially 2 to 50 nm, with a more preferred range of about 5-40 urn. Thus, the aspect ratio of the flakes of the present invention is in a preferred range of about 4 to 1250 with a more preferred range of about 42 tc 670. If a TiO: layer is deposited as a material of high refractive index, the Ti02 layer has a thickness of 20 to 200 nm, especially 50 to 200 nm. The total thickness of the Ti02-coated SiOy flakes is especially 150 to 450 nm. Starting, for example, from SiOy flakes (y = 1.4 to 1.8) having a thickness of 90 nm r 30 % it is possible to obtain red (ca. 73 nm), green (ca. 150 nrr.V or biue [ca. 130 nm) interference pigments by selecting the thickness of the Ti02 ieyer. Due i: the small thickness distribution of the SiOyflakes effect pigments result having a high coio- ounty. The SiOy fiakes may be oxidised using an oxygen-containing gas such as, to- exampie. ar at a temperature of at least 200°C, especially at above 400°C, preferably in the form of loose materia!, ir a fiuidised bed or by introduction into an oxidising flame, preferably a: a temperature ir the range from 500 to 1000°C, to form plane-parallel structures of S'Oz (WO03/063868;. Alternatively, the SiOy fiakes can be heated in an oxygen-free atmosphere'such as, to example, argon and/or helium or under a vacuum of less than 13 Pa ' 0'* ~o- a, a temperafjre o a: ieast 400°C, especially at above 400°C, preferably in the orrr of ioose materia!., in £ fiJiOised be6, preferably at a temperature in the range from 900 xz : :0C~C. tc Torrr. the silicon/silicon oxide flakes. Both the Si02 flakes as well as the siiicon/siiicor. cxide fiakes car. be used instead of the SiOy flakes as substrate for effect Metallic or nor-metallic. inorganic piateiet-shaped particles or pigments are effect pigments, ■especially me;a' effect pigments or interference pigments), that is to say, pigments that, oesiaes imparling colou- tc a" app'ication medium, impart additional properties, for example angle dependency of the colour (flop), lustre (not surface gloss) or texture. On metal effect pigments, substantially oriented reflection occurs at directionally oriented pigment particles. in the case o interference pigments, the colour-imparting effect is due to the phenomenon of interference o' light in thin, highly refractive layers. The .-freer; pigments according tc the invention can be used for ail customary purposes, for example for colouring polymers in the mass, coatings (including effect finishes, including those for the automotive sectc; and printing inks (including offset printing, intaglio printing, bronzing anc flexocraphic phnting;, and also, for example, for applications in cosmetics, in ink-jet printing, for dyeing textiles, glazes for ceramics and glass as well as laser marking of papers and plastics. Such applications are known from reference works, for example ' industrielie Organische Pigmente" (W. Herbst and K. Hunger, VCH Verlagsgesellschaft mbH, Weinheirrv'New York, 2nd, completely revised edition, 1995). When the pigments according to the invention are interference pigments (effect pigments), tney are gonioenromatic and result in brilliant, highly saturated (lustrous) colours. They are accordingly ver> especially suitable for combination with conventional, transparent pigments, for example organic pigments sucn as, for example, diketopyrrolopyrroles, quinacridones, dicxazines, pe-yteries jsoindoiinones etc., it being possible for the transparent pigment tc have a simiie.- colour tc the effect pigment. Especially interesting combination effects are ootained, noweven in analogy tc, ?or example, EP-A-388 932 or EP-A-402 943, when the coiour of the vansparen; pigment and that of the effect pigment are complementary. "~ne pigments according tc the invention can be used with excellent results for pigmenting high moiecu.a' weight organic material "ne hig- mo-ecu.ar weight organic material for the pigmenting of which the pigments or pigment compositions according tc the invention may be used may be of natural or synthetic origin. High moiecjia weight organic materials usually have molecular weights of about from 1C:' TC \0S z ~-o D" eve- mce. ""hey may be, for example, natural resins, drying oiis; rupee-or casei^.. z- -.a:j-a; sucstanoes ceriveti therefrom, such as chlorinated rubber, oi'-modifiec ateyc resins. , iscose. ceiiuiose etners or esters, such as ethylceliuicse, celiulose acetate, ceiijicse prop'onate, celuiose acetooutyrate or nitrocellulose, but especially totally synthetic organic polymers : thermosetting plastics and thermoplastics), as are obtained by poiymerisatb- pciyconcensaticn or polyaddition. From the class of the polymerisation resins there may ce mentioned, especially, polyolefins, such as polyethylene, polypropylene or posy:sopjryie~e anc ais: suostitutec potyolefins. such as polymerisation products of viny; cnionoe, v;~: ^cetai- sye^e. atryionirriie, acryiic acid esters, methacrylic acid esters or butadiene, anc aiso copoiymerisation products of the said monomers, such as especially ABS or EVA. From the series of the polyaddition resins and poiycondensation resins there may be mentioned, for example, condensation products of formaldehyde with phenols, so-called phenopiasts, and condensation products of formaldehyde with urea, thiourea or meiamine, so-called aminopiastsr.anc tne polyesters used as surface-coating resins, either saturated, such as aikyc resins, or unsaturates such as maieate resins; also linear polyesters and polyamides, DO;vurethanes or silicones. """->£ said hig.u molecular weicm compounds may be present singly or in mixtures, in the form Q:* clastic masses or melts. They may also be present in the form of their monomers or in the poiymerised state in dissolved form as film-formers or binders for coatings or printing inks, sucn as, for example, boiied linseed oil, nitrocellulose, alkyd resins, melamine resins and urea-formaldehvde resins or acrviic resins. Depending on the intended purpose, it has proved advantageous to use the effect pigments or effect pigment compositions according to the invention as toners or in the form of preparations. Depending on tne conditioning method or intended application, it may be advantageous to add certain amounts of texture-improving agents to the effect pigment before or after the conditioning process, provided that this has no adverse effect on use of the effect pigments for colouring high molecular weight organic materials, especially povethyiene. Suitaoie agents are, especially, fatty acids containing at least 18 carbon atoms, tcr exampie stearic or behenic acid, or amides or metal salts thereof, especially magnesium salts, and ais: piasticisers waxes, resin acids, such as abietic acid, rosin soap, alkylphenois c aliphatic aicohois, such as stearyl alcohol, or aliphatic 1,2-dihydroxy compounds containing from £ to 22 carbon atoms, such as 1,2-dodecanedio!, and also . modified edrophonium maieate resins o: fumaric acid colophonium resins. The texture-improving agents are acdec in amounts of preferably from 0.1 to 30 % by weight, especially from 2 to * 5 % by 'weight, based on tne end product. ~ne .'effect- pigments according to tne invention can be addec in any tinctorialiy effective amcjn; :c tne mgn noiecjia: weight organic material being pigmented. A pigmented supstance composition comprising t high molecular weight organic materia! and from 0.01 tc SC % by weight, preferably from: 0.1 tc 30 % by weight, based on the high molecular weight organic materia., of an pigment according to the invention is advantageous. Concentrations o\ from : to 20% by weight, especially of about 10% by weight, can often be used in practice. -\\Z' cor.cen::-a:;cns. :o- examoie tncse above 30% by weight, are usually in tne form c* concentrates ;masterbatches"} whicn can be used as colorants for producing pigmented materials having a relatively low pigment content, the pigments according to the invention having an extraordinarily low viscosity in customary formulations so that they can stilt be processed well. For the purpose of pigmenting organic materials, the effect pigments according to the invention may be used singly, it is, however, also possible, in order to achieve different hues or colour effects, to adc any desired amounts of other colour-imparting constituents, such as white, coloured, black or effect pigments, to the high molecular weight organic substances in addition to the effect pigments according to the invention. When coloured pigments are usee in admixture with the effect pigments according to the invention, the total amount is preferably from 0.1 to 10 % by weight, based on the high molecular weight organic material. Especially high goniochromicity is provided by the preferred combination of an effect pigment according to the invention with a coloured pigment of another colour, especially of a complementary colour, with colorations made using the effect pigment and colorations made using the coloured pigment having, at a measurement angle of 10°, a difference in hue (AH) of from 20 to 340, especially from 150 to 210. Preferably, tne effect pigments according to the invention are combined with transparent coloured pigments, it being possible for the transparent coloured pigments to be present either in the same medium as the effect pigments according to the invention or in a neighbouring medium. An exampie of an arrangement in which the effect pigment and the coloured pigment are advantageously present in neighbouring media is a multi-layer effect coating. The pigmenting of high moiecuia" weight organic substances with the pigments according to the invention is carried out. for example, by admixing such a pigment, where appropriate in the form o* a masteroatch. with the substrates using roll mills or mixing or grinding apparatuses. The pigmented material is then brought into the desired finai form using methods known per $e, sucr. as calendering, compression moulding, extrusion, coating, Douring or n ection moulding. Any additives customary in the plastics industry, such as piasttcisers. fibers or stabilisers, oar, be added to the polymer, in customary amounts, before or afte* hco'ooration of the pigment. In particular, in order to produce non-rigid shaped articles c TC -educe their brittieness. if is desirable to add plasticisers, for example esters of phosphoric ac;d; phthalic acta or seoacic acid, to the high molecular weight compounds prior to shaping. For pigmem.ng coatings anc ormtinc inks, the high molecular weight organic materials and tne effect pigments accorofnc t: tne invention, where appropriate together with customary additives sucn as, for example, fillers, other pigments, siccatives or plasticisers, are finely dispersed or dissolved in the same organic solvent or solvent mixture, it being possible for the individual components to be dissolved or dispersed separately or for a number of components tc De dissolved o* dispersed together, and only thereafter for all the components to be brought together. Dispersing an effect pigment according to the invention in the high molecular weight organic material being pigmented, anc processing a pigment composition according to the invention, are preferably carriec out suojec; to conditions under which only relatively weak shear forces occur so that the effect pigment is not broken up into smaller portions. Plastics comprising the pigment of the invention in amounts of 0.1 to 50 % by weight, in particular C.5 tc 7 % by weight, in the coating sector, the pigments of the invention are employed in amounts of C.l tc 10 % by weight. In the pigmentation of binder systems, for example for paints and printing inks for intaglio, offset or screen printing, the pigment is incorporated into the printing ink in amounts of 0.1 to 50 % by weight, preferably 5 to 30 % by weight and in particular 8 tc 15 % by weight. The colorations obtained, for example in plastics, coatings or printing inks, especially in coatings or printing inks, more especially in coatings, are distinguished by excellent properties, especially by extremely high saturation, outstanding fastness properties, high color purity and hign goniochromicity. Wnen the high molecular weight material being pigmented is a coating, it is especially a speciality coathc, very especially an automotive finish. The-effect pigments according to the invention are also suitable for making-up the lips or the skin and for coiourinc the hair or tne naiis. The invention accordingly relates also to a cosmetic preparation or formulation comprising from G-0001 tc 9C % by weight o; a pigment, especially an effect pigment, according to the Invention anc f-om 10 to 9S.999? % of a cosmetically suitable carrier material, based on the iota! weight of the cosmetic preparation or formulation. £ucn cosmetc preparations or formulations are, for example, lipsticks, blushers, foundations. nai; varnishes and hair shampoos. "The pigments may be usee singly or in the form of mixtures. It is, in addition, possible to use pigments according tc the invention together with other pigments and/or colorants. for example in coronations as Described hereinbefore or as known in cosmetic preparations. Tne cosmetic preparations anc formulations according to the invention preferably contain the oicment acceding tc trie invention ir an amount from 0.005 to 50 % by weight, based on the total weight of the preparation. Suitable carrier materials for the cosmetic preparations and formulations according to the invention include the customary materials used in such compositions. The cosmetic preparations and formulations according to the invention may be in the form of, for example, sticks, ointment creams, emulsions, suspensions, dispersions, powders or solutions. They are, for exempt, lipsticks, mascara preparations, blushers, eye-shadows, foundations, evelne-r rowoer c nail varnishes. It' the preparations are in tne form of sticks, for example lipsticks, eye-shadows, blushers or foundations, the preparations consist for a considerable part of fatty components, which may consist of one c~ nee -.•axes. 'c- example ozokerite, lanolin, lanolin alcohol, hydrogenated lanolin, acetyiated lanolin, lanoim wax, beeswax, candelilla wax, microcrystalline wax, carnauba wax. cetyl aicoho:. stearyl alcohol, cocoa butter, lanolin fatty acids, petrolatum, petroleum jelly, mono-, di- or tn-glycerides or fatty esters thereof that are solid at 25°C, silicone waxes, such as metnyloctadecane-oxypolysiloxane and poly(dimethylsiloxy)-stearoxysiloxane, stearic acio monoethanolamine, colophane and derivatives thereof, such as glycol abietates anc giycero abietates, hydrogenated oils that are solid at 25°C, sugar glycerides anc olea:esT myristates. lanolates, stearates and dihydroxystearates of calcium, magnesium, zirconium anc aluminium. The fatty component ma\ aisc consist, of a mixture of at least one wax and at least one oii, in which case tne following oils, for example, are suitable: paraffin oil, purcelline oil, perhyarosquaiene, sweet a;monc oil, avocado oil calophyllum oil, castor oii, sesame oil, ioiooa oi!. mineral oiis having a coiling point of about from 310 to 410°C, silicone oils, such as dimethylpoiysiicxane, iinoiey accnoi, linolenyl alcohol, oleyi alcohol, cereal grain oils, such as wneatgerm ol.: isop-opy. .a~o,a:e. isopropyl paimitate, isopropyl myristate, butyl myristate, cetyi myristate. hexaoec/ stea-ate. butyl stearate, decyl oieate, acetyl glycerides, octanoates anc oecanoates o: aiconois an: ooiyaicohols, for example of glycol and glycerol, ricinoleates of aicohois anc poiy&ioonois. for example of cetyl alcohol, isosteary! alcohol, isocetyl ianoiate, isooropy: adipaie ne>:y ;aurate and octy! dodecanol. The :at~\' components r sue** cecarations in the form: of sticks may generally constitute u: tc 99.t* c/c D> weight o- tne i:;a weight of the preparation. Tne cosmetic prepa-at:ons anc crmulations according to the invention may additionally comprise runner constituents, such as, for example, glycols, polyethylene glycols, polypropylene glycols., monoalkanolamides, non-coloured polymeric, inorganic or organic fillers, preservatives. JV friters c- other adjuvants and additives customary in cosmetics, for example a natural or syntnetic o: carnally synthetic di- or tri-giyceride, a mineral oil, a silicone oi., a wax. a 'atty aiconc. c 3.-erre; aicoho! or ester thereof, a lipophilic functional cosmetic active ingredient, including sun-protection filters, or a mixture of such substances. A lipophilic functional cosmetic active ingredient suitable for skin cosmetics, an active ingredient composition or an active ingredient extract is an ingredient or a mixture of ingre- dients that is approved for oermal or topical application. The following may be mentioned by way of example: active ingredients having t cleansing action on the skin surface and the hair; these include all substances the: serve to cleanse the skin, such as oils, soaps, synthetic detergents and solid suostances; active ingredients having a deodorising and perspiration-inhibiting action: they include antiperspirants based on aluminium salts or zinc salts, deodorants comprising bactericidal or bacteriostatic deodorising substances, for example triclosan, hexachlorophene, alcohols and cationic substances, such as, for example, quaternary ammonium salts, and odour absorbers, for example "'Grillocin (combination of zinc ricinoleate and various additives) or triethyl citrate (optionally in combination with an antioxidant, such as, for example, butyl hydroxytoluene) or ion-exchange resins; active ingredients that offer protection against sunlight (UV filters): suitable active ingredients are filter substances (sunscreens) that are able to absorb UV radiation from sunlight and convert it into heat; depending on the desired action, the following light-protection agents are preferred: light-protection agents that selectively absorb sunburn-causing high-energy UV radiation in the range of approximately from 280 to 315 nm (UV-B absorbers) and transmit the longer-wavelength range of, for example, from 315 to 400 nm (UV-A range), as well as light-protection agents that absorb only the longer-wavelength radiation of the UV-A range of from 315 to 400 nm (UV-A absorbers); suitable light-protection agents are, for example, organic UV absorbers from the class of the p-aminobenzoic acid derivatives, salicylic acid derivatives, benzophenone derivatives, dibenzoylmethane derivatives, dipheny! acrylate derivatives, benzofuran derivatives, polymeric UV absorbers comprising one or more organosiiicon radicals, cinnamic acid derivatives, camphor derivatives, trianilino-s-triazine derivatives, phenyi-benzimidazoiesulfonic acid and salts thereof, menthyi anthraniiates, benzotriazoie derivatives, and/or an inorganic micropigment selected from aluminium oxide- or silicon dioxide-coated Ti02, zin: oxide or mica; active ingredients against insects (repellents) are agents that are intended to prevent insects products and lanolin for protection against aqueous solutions, film-forming agents, such as sodium alginate, triethanolamine alginate, polyacrylates, polyvinyl alcohol or cellulose ethers for protection against the effect of organic solvents, or substances based on mineral oils, vegetable oils or silicone oils as "lubricants" for protection against severe mechanical stresses on the skin; moisturising substances: the following substances, for example, are used as moisture-controlling agents (moisturisers): sodium lactate, urea, alcohols, sorbitol, glycerof, propylene glycol, collagen, elastin and hyaluronic acid; active ingredients having a keratoplasty effect: benzoyl peroxide, retinoic acid, colloidal sulfur and resorcinol; antimicrobial agents, such as, for example, triclosan or quaternary ammonium compounds; oily or oil-soluble vitamins or vitamin derivatives that can be applied dermally: for example vitamin A (retinol in the form of the free acid or derivatives thereof), panthenol, pantothenic acid, folic acid, and combinations thereof, vitamin E (tocopherol), vitamin F; essential fatty acids; or niacinamide (nicotinic acid amide); vitamin-based placenta extracts: active ingredient compositions comprising especially vitamins A, C, E, Bi, B2, B6, B«2, folic acid and biotin, amino acids and enzymes as well as compounds of the trace elements magnesium, silicon, phosphorus, calcium, manganese, iron or copper; skin repair complexes: obtainable from inactivated and disintegrated cultures of bacteria of the bifidus group; plants and plant extracts: for example arnica, aloe, beard lichen, ivy, stinging nettle, ginseng, henna, camomile, marigold, rosemary, sage, horsetail or thyme; animal extracts: for example royal jelly, propolis, proteins or thymus extracts; cosmetic oils that can be applied dermally: neutral oils of the Miglyol 812 type, apricot kernel oil, avocado oil, babassu oil, cottonseed oil, borage oil, thistle oil, groundnut oil, gamma-oryzanol, rosehip-seed oil, hemp oil, hazelnut oil, blackcurrant-seed oii, jojoba oil, cherry-stone oii, salmon oil, linseed oil, cornseed oil, macadamia nut oil, almond oil, evening primrose oil, mink oil, olive oil, pecan nut oil, peach kernel oil, pistachio nut oil, rape oil. rice-seed oil, castor oil, safflower oil, sesame oil, soybean oil, sunflower oil, tea tree oii, grapeseed oii or wheatgerm oil. The preparations in stick fornn are preferably anhydrous but may in certain cases comprise a certain amount of water which, however, in general does not exceed 40 % by weight, based on the total weight of the cosmetic preparation. If the cosmetic preparations and formulations according to the invention are in the form of semi-solid products, that is to say in the form of ointments or creams, they may likewise be anhydrous or aqueous. Such preparations and formulations are, for example, mascaras, ~ eyeliners, foundations, blushers, eye-shadows, or compositions for treating rings under the eyes. If, on the other hand, such ointments or creams are aqueous, they are especially emulsions of the water-in-oil type or of the oil-in-water type that comprise, apart from the pigment, from 1 to 98.8 % by weight of the fatty phase, from 1 to 98.8 % by weight of the aqueous phase and from 0.2 to 30 % by weight of an emulsifier. Such ointments and creams may also comprise further conventional additives, such as, for example, perfumes, antioxidants, preservatives, gel-forming agents, UV filters, colorants, pigments, pearlescent agents, non-coloured polymers as well as inorganic or organic fillers. If the preparations are in the form of a powder, they consist substantially of a mineral or inorganic or organic filler such as, for example, talcum, kaolin, starch, polyethylene powder or polyamide powder, as well as adjuvants such as binders, colorants etc.. Such preparations may likewise comprise various adjuvants conventionally employed in cosmetics, such as fragrances, antioxidants, preservatives etc.. If the cosmetic preparations and formulations according to the invention are nail varnishes, they consist essentially of nitrocellulose and a natural or synthetic polymer in the form of a solution in a solvent system, it being possible for the solution to comprise other adjuvants, for example pearlescent agents. In that embodiment, the coloured polymer is present in an amount of approximately from 0.1 to 5 % by weight. The cosmetic preparations and formulations according to the invention may also be used for colouring the hair, in which case they are used in the form of shampoos, creams or gels that are composed of the base substances conventionally employed in the cosmetics industry and a pigment according to the invention. The cosmetic preparations and formulations according to the invention are prepared in conventional manner, for example by mixing or stirring the components together, optionally with heating so that the mixtures melt. The Examples that follow illustrate the invention without limiting the scope thereof. Unless otherwise indicated, percentages and parts are percentages and parts by weight, respectively. Examples example in a vacuum system which n its fundamental points is constructed analogously to the system described ir. 115-5-6,270,5^0, the following are vaporised, from vaporisers, in succession: sodium chloride (Nad) as separating agent at about 900°C, and silicon monoxide (SiO) as reaction product ol 5. ana Si02 at trom 1350 to 1550°C. The layer thickness of NaCi is typically 30-50 nm., that of SiOy being, depending on the intended purpose of the end product, from 100 tc 2000 nm. in ne present case 200 nm. Vaporisation is carried out at about 0.02 Pa, amounting to about 11 g of Nad and 72 c of SiO per minute. For subsequently detaching the layers by dissolution of the separating agent the carrier on which vapour-deposition has taken place is sprayed at about 3000 Pa with deionised water and treated with mechanical assistance using scrapers and with ultrasound. Tne NaCi dissolves and the SiOy layer, which is insoluble, breaks up into flakes, Tne suspension is continuously removed from the dissolution chamber and, at atmospheric pressure, is concentrated by filtration and rinsed several times with deionised water in order to remove Na~ and 3" ions that are present. That is followed by the steps of drying and heating the plane-parallel SiCX structures in the form of loose material at 500 to 600°C for two hours in an oven through which air heated to 500 to 600°C is passed. After cooling, comminution and grading by ar-sieving are camiec out. Seispie! 2 "wc Layer System * TiO? Layer- :00 g ol the SiC, f.aKes octanec ir. example 1 are suspended in 1,5 I fully deionized water ano heated tc " £D. To tnis suspension 160 ml of an aqueous solution of TiCL (400 g TiCL-1; is rnetereo witn:n 90 minutes. Tne or is kept constant at pH=2.2 by means of 32% sodium hydrcxioe solution. After tnis soL'tio- nas been added, the mixture is stirred for a further 2 SiC-Level Tne pK of the suspension, is increased by means of sodium hydroxide solution to 7,5 and within 3.5 hou-s 720 m! a sodiu~ water glass solution is metered (125 g SiCyi) at 75 °C. Dunne tne aod :;on the pr is kept constant by means of 10% hydrochloric acid. After this solution has Pee" adoec. the m;x:u*e is stirred for a further 30 minutes at 75 °C "he tnus ootarec oigmem is cna'acterized intense blue interference color. Example 3 3 Layer System comprising a Fer03 Layer 1) TiO? Layer: The Ti02 layer is obtained as described in Example 1. 2) SiO? Layer: The Si02 layer is obtained as described in Example 1, 3) Fe?Q, Layer: The pH of the suspension of the silicon oxide flakes coated succesively with Ti02 and Si02 is controlled by means of 10% hydrochloric acid to 3.0. Then 1750 ml of an aqueous FeClr Losung (35 g Fe/I) are added at 75 °C within 5 h. The pH is kept constant by simultaneously adding 32% NaOH. After this solution has been added, the mixture is stirred for a further approximately 45 minutes at 75 °C. After the suspension has cooled to room temperature, the product is filtered, washed saltfree with water and dried at 110 °C. Then the pigment is calcinated 30 minutes at 850 °C. Example 4 250 mg of 295 nm thick SiOv (y - 1.7-1.8) flakes (average diameter - 50 microns), which have a green color on a black background, are mixed in 35 ml deionized water and then heated to 60°C. The pH is adjusted to 1.4with 1N hydrochloric acid. 10 ml of TiOCI2 (diluted w'rth 1N HCI, such that the solution comprises 1.5 % of titanium) are added to the solution during 5-.hours, while maintaining the pH at 1.4 by continuous addition of sodium hydroxide. The liquid is cooled to room temperature and filtered with a 20 micron sieve. The obtained powder is dried for 1 hour at 60°C in air. White looking flakes are obtained which have a bright blue color when viewed on a black background. The color depends on the observation angle and turns violet and then yeliow when increasing the viewing angle. Claims 1. A pigment, the particles of which generally have a length of from 2μ m to 5 mm, a width of from 2 urn to 2 mm, and a thickness of from 20 nm to 2 μm, and a ratio of length to thickness of at least 2:1, wherein the particles contain a core of SiOy with 0.70 1.95, especially 1.1 2. The pigment, the particles of which generally have a length of from 2 μm to 5 mm, a width of from 2 μm to 2 mm, and a thickness of from 20 nm to 2μm, and a ratio of length to thickness of at least 2:1, wherein the particles contain a core of SiOy with 0.70 distance between which is the shortest axis of the core, comprising (a) a thin semi-transparent metal layer. 3. The pigment according to claim 1, wherein the pigment comprises in addition (b) a metal oxide of low refractive index, wherein the difference of the refractive indices is at least 0,1. 4. The pigment according to claim 1 or 3, wherein the metal oxide of high refractive index is TiC2, Zr02t Fe2Q5, Fe304, Cr203, ZnO or a mixture of these oxides or an iron titanate, an iron oxide hydrate, a titanium suboxide or a mixture and/or mixed phase of these compounds. 5 The pigment according tc any of claims 1,3, or 4, wherein the metai cxide of low index of refraction is Si02, Ai2Os. AIOOH, Bo03, or a mixture thereof, wherein alkali or earth alkali metal oxides can be contained as additional component. 6. The pigment according to any of claims 1 to 5, wherein the SiOy core nas a thickness of from 20 tc 200 nm, especially from 50 to 150 nm, most preferred 6C to 120 nm. 7. A process for producing the interference pigment according to any of claims 1 and 3 to 6, by alternately coating SiOy flakes with a metal oxide with a high refractive index and a metal oxide with a low refractive index in a wet process by hydrolysis of the corresponding water-soluble metal compounds, by separating, drying and optionally calcinating the pigment thus obtained. 8. A process for producing the pigment according to claim 2, wherein SKDy flakes are suspended in an aqueous and/or organic solvent containing medium in the presence of a metal compound and the metal compound is deposited onto SiOy flakes by addition of a reducing agent. 9. A pigment, the particles of which generally have a length of from 2 μm to 5 mm, a width of from 2 μm to 2 mm, and a ratio of length to thickness of at least 2:1, wherein the particles contain a core of Si02or a silicon/silicon oxide core obtainable by heating SiOy flakes with 0.70 temperature of at least 400°C, having two substantially parallel faces, the distance between which is the shortest axis of the core, comprising a material, especially a metal oxide, having a high index of refraction, or a thin semi-transparent metal layer and optionally further layers, wherein the core has a thickness of from 20 to 200 μm, especially from 40 to 150 nm, most preferred 60 to 120 nm. 10. Use of the pigments according to any of claims 1 to 6 or 9 in paints, ink-jet printing, for dyeing textiles, for pigmenting coatings, printing inks, plastics, cosmetics, glazes for ceramics and glass. 11. Paints, printing inks, plastics, cosmetics, ceramics and glass, which are pigmented with a pigment Pigment according to any of claims 1 to 6 or 9.

Full Text

Interference pigments on the basis of silicon oxides
The present invention relate: to (interference) pigments having a core of SiOy with 0.70 plastics, cosmetics, giazes fo" ceramics and glass.
Interference pigments having a core of Si02 are known (Gerhard Pfaff and Peter Reynders, Chem. Rev. 99 (1999) 1963-1981):
The Si02 flakes are produced, for example, by a process described in WO93/08237, wherein a sodium water glass solution is applied as a thin film on an endless band, solidified and dried. WO93/08237 also describes the coating of the Si02 flakes with a metal oxide having a high index of refraction or a tnin semi-transparent metal layer.
W098/53011 discloses multi-coated interference pigments consisting of a transparent carrier material which is coated with alternating metal oxide layers with a high and low refractive index, wherein the difference between the respective refractive indexes is 0.1. The metal oxide layers are obtained in a wet process by hydrolysis of the corresponding water-soluble metal compounds, by separating, drying and optionally calcinating the pigment thus obtained.
WO01/57257 Describes a orocess comprising the production of a substrate material, for example, silicon oxide, by physical vapor deposition and the wet chemical coating of the obtained fiakes with, for exanoie, Ti02. According to Example 4 of WO01/57287 silicon cxiae fiakes having a thickness of 200 nm and a particle size of 1 to 100 ^m are obtained by ?VD and then coatee by a wet chemical process with Ti02.
EF-A-8Q35-S discloses coloured pigments containing (a) a core consisting of an essentially transparent o: metallic reflecting material, and (b) at least a coating consisting essentially of one or more silicone oxides, the moiar ratio of oxygen to a silicon being 0.25 to 0.95;
it is the object of the present invention to provide interference pigments, having higher color strength and color purity as compared with interference pigments known from the state of the

Said object has been soivecd by pigments, the particles of which generally have a length of from 2 μm to 5 mm, a width of from 2 |μm to 2 mm, and a thickness of from 20 nm to 2 μm, and a ratio of length to thickness of at least 2:1, wherein the particles contain a core of SiOy with 0.70 Tne term "SiC. with C.7C ≤ \ ≤ 1.95" means that the molar ratio of oxygen to silicon at the average value of the silicon oxide layer is from 0.70 to 1.95. The composition of the silicon oxide layer can be determined by ESCA (electron spectroscopy for chemical analysis).
According t: the presen; indention the term "aluminum" comprises aluminum and alloys of aluminum. Alloys of aiuminum are, for example described in G. Wassermann in Ullmanns Enzykiopadie der tocustrieiier Cnemie, 4. Auflage, Verlag Chernie, Weinheim, Band 7, S. 2£1 to 292. Especially suitaoie are the corrosion stable aluminum alloys described on page 1C to "12 of WO00/12SS4. wnich comprise besides" o'f aluminum silicon, magnesium, manganese, copper, zinc, nick©;, vanadium, lead, antimony, tin, cadmium, bismuth, titanium, Chromium and/or iron in amounts of less than 20 % by weight, preferably less than 10 % by weight.
Suitable metals for the sem:-t:ansparent metal layer are, for example. Cr: Ti, Mc, W, A!, Cu, Ac. Au, or J\;. The $emi-:ra~;sparen: metal layer has typically a thickness of between 5 and 25 nm. especiai'y between 5 and 1c nm. The SiOy substrates can have a metal layer only on one paraiie' surface, but prefsraoiv the metal layer is present on both parallel faces of the
suostrate.
The metal/SiOy/metal flakes are prepared by a PVD process comprising the steps:
a) vapour-deposition of a separating agent onto a (movable) carrier to produce a separating agent layer,
b) vapour-deposition of a metal layer onto the separating agent layer,

c) vapour-deposition of an SiCy layer onto the metal layer, wherein 0.70 £ y £ 1.80,
d) vapour-deposition of a metal layer onto the SiOy layer,
e) dissolution of the separating agent layer in a solvent, and 0 separation of the metal'SiGyme-ia!-flakes from the solvent.
Alternatively the metal layer can be obtained by wet chemical coating or by chemical vapor deposition, to: example, gas pnase deposition of metal carbonyls. The substrate is suspended in an aqueous and'or organic solvent containing medium in the presence of a metal compound and is deposited onto the substrate by addition of a reducing agent. The metal compound is, for examplel, silver nitrate or nickel acetyl acetonate (WO03/37993).
According to US-5-3,536,520 nickel chloride can be used as metal compound and hypophosphite can be used as reducing agent. According to EP-A-353544 the following compounds can be used as reducing agents for the wet chemical coating: aldehydes (formaldehyde, acetaldehyde: oenzalaldehyde), ketones (acetone), carbonic acids and salts thereof (tar:aric acid, ascorbinic acid), reductones (isoascorbinic acid, triosereductone, reductine acid}, and reducing sugars (glucose).
If semi-transparent metal layers are desired, the thickness of the metal layer is generally between 5 anc 25 nm, especially between 5 and 15 nm.
If pigments witr metallic appearance are desired, the thickness of the metal layer is > 25 nm tc IOC nm, preferably 30 tc 50 nm. If pigments with colored metal effects are desired, aoditionai layers of colored or colorless metal oxides, metal nitrides, metai suldfides and/or metais ca~ oe deposited, ~~hese layers are transparent or semi-transparent, it is preferred tr.a: iaye-s :" nigr index o* refraction and layers of low index of refraction alternate or that :ne layer := present, whereir- within the layer the index of refraction is gradually changing. It is possible 'or the weatherinc resistance to be increased by means of an additional coating, which at the same time causes an optima! adaption to the binder system (EP-A-268918 and
EP-A-632109r, one pre;e~ec emoodirnen: of tne present invention, the interference pigments comprise materials ha,ving "nign1 inae> o; redaction, which is defined herein as an index o£ refraction of greater man about 1.65, and optionally materials having a "low" index of refraction, which is defined herein as an index of refraction of about 1.65 or less. Various (dielectric) materials that can be utilized including inorganic materials such as metal oxides, metal suboxides,

rnetai fluorides, metal oxyhahces, metal sulfides, metal chaicogenides, metal nitrides, metal
oxynitrides, metal carbides, combinations thereof, and the like, as well as organic dielectric
materials. These materials are readily available and easily applied by physical, or chemical
vapor deposition processes, o' ry wet chemical coating processes. - -
in an especially preferred emdociment, the interference pigments on the basis of the silicon oxide substrate comprises a further lc/e* of a dielectric material having a "high" refractive index, that is to say a refractive index greate' than about 1.65, preferably greater than about 2.0, most preferred greater than about 2.2. which is applied to the entire surface of the silicon/silicon oxide substrate. Examples of such a dielectric material are zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (Zr02), titaniur dioxide (Ti02), carbon, indium oxide (ln203), indium tin oxide (ITO), tantalum pentoxide (Ta2O2;, chromium oxide (Cr203), cerium oxide (Ce02), yttrium oxide (Y203)( europium oxide (Eu203;, iron oxides such as iron(ll)/iron(lll) oxide (Fe304) and iron(lll) oxide (Fe2C3); hafnium nitride HfN), hafnium carbide (HfC), hafnium oxide (Hf02), lanthanum oxide (La202), magnesium oxide (MgO), neodymium oxide (Nd203), praseodymium oxide (Pr6Or), samarium oxide (Sm2C5;. antimony trioxide (Sb203), silicon monoxides (SiO), selenium1 trioxide (Se2O3).. tin oxide (3nC2i. tungsten trioxide (W03) or combinations thereof. The dielectric material is preferably a metai oxioe. It being possible for the metal oxide to be a single oxide or a mixture of cxces. witr. or without absorbing properties, for example, Ti02l Zr02l Fe203) Fe^O*, C^npz or Z.nC witn ~I02 being esoeciaily preferred.
It is possible to obtain pigments that are more intense in colour and more transparent by applying, or to: o; the TiO^ laye', a metai oxide of low refractive index, such as Si02i Al^Os, AlOOK, B23: or 5 mixture thereof, preferably Si02, and optionally applying a further Ti02 iayer on tor of the latter lave- EF-A-892832, EP-A-753545, WO93/08237, W098/53C"-. W036-225S. W09S3E25^. WD99/20695, WOOO/42111, and EP-A-1213330). Nonlimitinc examples c suitable iovv index dielectric materials that can be usee include silicon dioxide (SiO:), aluminum oxide ;AI2G3 . and meta! fluorides such as magnesium fluoride (MgF2!, aluminum f;uoride (AIF3): cerium ^joride (CeF3), lanthanum fluoride (LaF3), sodium aluminum fluorides (e.g., Na3AiF€ or Na2A6-, neodymium fluoride (NdF3), samarium fluoride (SmF3;., barium! fiuo*:ae (BsF2). calcium fluoride (CaF2), lithium fluoride (LiF), combinations thereof, or any otner ;c*v index materia! having an index of refraction of about 1.65 or less. For example, organic monomers anc polymer can be utilized as low index.materials, including dienes or alkenes such as acrylates (e.g., methacrylate), polymers of perfluoroalkenes, polytetrafluoroethylene (TEFLON), polymers of fluorinated ethylene propylene (FEP), parylene, p-xylene, combinations thereof, and the like. Additionally, the foregoing materials

include evaporated, condenses and cross-linked transparent acrylate layers, which may be Deposited by methods described in U.S. Pat. No. 5,877,895, the disclosure of which is
incorporatec herein by reference.
Accoraingly, preferred interference pigments comprise besides (a) a metal oxide of high 'efractlve index in addition and 't, a metal oxide of low refractive index, wherein the difference
o*' the tractive indices is a: leas: C\1.
Pigments on the basis of silicon oxide (SiOy) substrates, which have been coated by a wet
chemical methoc, in the indicated order are particularly preferred:
~iO; (substrate: silicon oxide: iayer: Ti02, preferably in the rutile modification), (Sn02)Ti02,
Fe203. Fe3C4l TiFe205, Cr203l Zr02, Sn{Sb)02, BiOCI, Al203f Ce2S3, MoS2( Fe203*Ti02 i substrate: silicon oxide; mixec iayer of Fe203 and Ti02), TiO^Fe^ (substrate: silicon oxide;
firs: iayer: TiC2: second layer: Fe203), Ti02/Berlin blau, TiOa/Cr203lorTi02/FeTi03. In genera! the iayer thickness ranges from : to 1000 nm, preferably from 1 to 300 nm.
in anotner panicuiariy preferred embodiment the present invention relates to interference olgmsnts containing at ieas: tnree alternating layers of high and low refractive index, such as, for exampie. TiCySiCg/TjC^ 'SnG^TiCySiCVTiCk TiOa/SiOa/TiCVSKVTiOz or Ti02/Si02/Fe203:
^eferab*y tn~ lave- structure is as TOIIOWS: .-.. a coating navng a refractive mosx > 1.65, ■5 a coating navng a refractive inoex 1,65, and 'D; ootional!} an outer protective iayen
~v: tnicKness c*' tne ndivbua; ;svers of hiah and low refractive index on the base substrate is essentia to- :~e ootioa! ore-Denies of tne pigment. The thickness of the individual layers, especially me:a oxide ieyers: depends on the field of use and is generally 10 to 1000 nm,
oreferabiv 15 :: S00 nm. In oartbuia* 20 to 600 nm.
The thicKness o: iayer (A) is : 0 :o 55C nm, preferably 15 to 400 nm and, in particular, 20 to 350 nm. Tne thickness o* iayer ;3 is IC ;c '000 nm, preferably 20 to 800 nm and, in particular. 30 to 50: nm. ~ne :- .coess o: is ye" \Z is ' l to 550 nm, preferably 15 to 400 nm and, in particular, 20 to 350 nm.

Particularly suitable materials for iayer (A) are metal oxides, metal sulfides, or metal oxide mixtures, such as Ti02) Fe2C,. 7iFe205, Fe304, BiOCl, CoO, C03O4, Cr203, V02, V203, 3n(Sb)02l SnG2l Zr02l iron titanates, iron oxide hydrates, titanium suboxides (reduced titanium species having oxicatic- states from 2 to Particularly suitable materials ~or iayer (B) are metal oxides or the corresponding oxide hydrates, such as Si02) MgF: A;s03, AIOOH, B203 or a mixture thereof, preferably Si02.
Particularly suitable materials for iayer (C) are colorless or colored metal oxides, such as Ti02, Fe203 TiFe205! Fe30*, BiOC . OoC, Co304, Cr203, V02, V203, Sn(Sb)02, Sn02, Zr02, iron titanates, iron oxide hydrates Titanium suboxides (reduced titanium species having oxidation states from 2 to intenayers c* absorbing or nonaoso-oinc materials can be present between layers (A), (3), (C and \D). The thickness 0** tne r.ieriayers is 1 to 50 nm, preferably 1 to 40 nrr. and, in particular, 1
-^ %r nrr,

The pigments of the present invention are characterized by the precisely defined thickness and smooth surface of the thir. SiCv flakes.
The metal oxide layers can be applied by CVD (chemical vapour deposition) or by wet chemical coaling. Tne metai oxide layers can be obtained by decomposition of metal carbonyis in tne presence of water vapour (relatively low molecular weight metal oxides SUCH as magnetite"' or r, the presence of oxygen and, where appropriate, water vapour (e.g. nickel oxide and cooait oxide}. The metal oxide layers are especially applied by means of oxidative gaseous ohase decomposition of meta! carbonyls (e.g. iron pentacarbonyl, chromium: nexacaroony:: Er-A-45 85".). by means of hydrolytic gaseous phase decomposition of metal ascohoiates e o. titanium and zirconium tetra-n- and -iso-propanolate; DE-A-41 40 900) c o* meta' haiioe^ e.c. titanium tetraohioride; EP-A-338 428), by means o* oxidative decomposition y croany; tin compounds (especially alky! tin compounds such as tetrabutyftir and tetrametny!;;-, DE-A-44 Zc £78, or by means of the gaseous phase hydrolysis of organy silicon compound (especially C:-ten-butoxyacetoxysiIane) described in EP-A-668 329, it oeinc oossbie fc tne coating ooeration to be carried out in a fluidisec-Dec reactor :'EP-A-04£ Eft ano EF-A-105 235\ Ai2Os layers (B) can advantageous1)' be obtained by conrolied ox^oaTiO" curing tne cool;':: of aluminium-coated pigments, which is otherwise cameo out -nae- met gas (DE-A--. ?5 16 161).
Pnosphate-. cremate- and'b' vanac'ate-containing and also phosphate- and SiOj-containin: meta1 oxide ;avers can be aooiieo r accordance with the passivation methoos described r DE-A-42 3r 332 and \r EP-A-S7E 561 by means of hydrolytic or oxidative gaseous phase decomposition o" cxide-nalides o* tne metais (e.g. CrC2C\2. VOCi3), especially of phosphorus cxynaiices ,e.c PCC^;. phosphoric and phosphorous acid esters (e.g. df- ano tri-metnyi ano di- and tri-etny! phosphite) and of amino-group-containing organyl silicon compounds (e.g. 3-aminopropyi-triethoxy- and -trimethoxy-silane).

Levers of oxides of the metais zirconium, titanium, iron and zinc, oxide hydrates of those metals, iron titanates, titanium suboxides or mixtures thereof are preferably applied by precipitation by a wet chemical method, it Deing possible, where appropriate, for the metal oxides to be reduced. In the case of the wet chemical coating, the wet chemical coating methods developed for the -production o\ peariescent pigments may be used; these are described, for example, in DE-A-14 67 458, DE-A-19 5S 988, DE-A-20 09 566, DE-A-22 14 545, DE-A-22 15 191, DE-A-22 44 298: DE-A-2S rf2 331, DE-A-25 22 572, DE-A-31 37 808, DE-A-31 37 809, DE-A-31 51 343, DE-A-31 51 354, DE-A-31 51 355, DE-A-32 11602 and DE-A-32 35 017, DE 195 99 88. WO 93/08237, WO 98/53001 and WO03/6558.
The metal oxide of high refractive index is preferably Ti02 and/or iron oxide, and the metal oxide of low refractive index is preferably Si02. Layers of T1O2 can be in the rutile or anastase modification, wherein the rutile modification is preferred. Ti02 layers can also be reduced by known means, for example ammonia, hydrogen, hydrocarbon vapor or mixtures thereof, or metal powders, as described in EP-A-735,114, DE-A-3433657, DE-A-4125134, EP-A-332071, EP-A-707,050 or W093'19131.
"or the purpose of coating, tne substrate particles are suspended in water and one or more hydrolysabie metal salts are aooec at a pH suitable for the hydrolysis, which is so selected that tne metal oxides or "metal cxiae nydrates are precipitated directly onto the particles without subsidiary precipitation, occurring. Tne pH is usually kept constant by simultaneously metering in a base. The pigments are tner separated off, washed, dried and, where appropriate, calcinated, it being possible tc optimise tne calcinating temperature with respect to the coating in question. If desired, after individual coatings nave been applied, the pigments can be separated off, dried and, wnere appropnate, calcinate! and then again re-suspended for the purpose of precipitating turner levers.
Tne metai cxibe layers are a:sc obtainable, for example, in analogy to a methoc described in DE-A-195 C 307, by producing the metal oxide layer by controlled hydrolysis of one or more metai acic esters, where appropriate in the presence of an organic solvent and a basic catalyst, b\. means 0' a so-ge process. Suitable basic catalysts are, for example, amines, such as thethyiamine, e:~yienediamine, tributylamine, dimethylethanolamine and methcxy-prooylamine Tne prganic so'ven* T a water-miscible organic solvent such as a C^aicoho!. especially isopropanol.

Suitable metal acid esters are selected from alkyl and aryl alcoholates, carboxylates, and carboxyl-radicai- or alkyl-radicai- or aryl-radical-substituted alkyl alcoholates or carboxylates of vanadium, titanium, zirconium, silicon, aluminium and boron. The use of triisopropyi aluminate, teuaisopropy! titanate, tetraisopropyl zirconate, tetraethyl orthosilicate and triethy1 borate is preferred. In addition, acetylacetonates and acetoacetylacetonates of the aforementioned metals may be used. Preferred examples of that type of metal acid ester are zirconium acetylacetonate, aluminium acetylacetonate, titanium acetylacetonate and diisobutyloleyl acetoacetylaiuminate or diisopropyloleyl acetoacetylacetonate and mixtures of metal acid esters, for example Dynasi® (Huls), a mixed aluminium/silicon metal acid ester.
As a metal oxide having a high refractive index, titanium dioxide is preferably used, the method described in US-B-3 552 001 being used, in accordance with an embodiment of the present invention, for application of the titanium dioxide layers.
An aqueous titanium salt solution is slowly added to a suspension of the material being coated, whic~ suspension has-been heated to about 50-100°C, especially 70-80°C, and a substantially constant pH vaiue of about from 0.5 to 5, especially about from 1.2 to 2.5, is maintained Dy simultaneously metering in a base such as, for example, aqueous ammonia solution or aoueous alkali metal hydroxide solution. As soon as the desired layer thickness of precipitated "HO: nas been achieved, the addition of titanium salt solution and base is stopped.
This metnoc a: so referred tc as the "titration method", is distinguished by the fact that an excess of titanium salt is avoided. That is achieved by feeding in for hydrolysis, per unit time, only that amount whic~ is necessary for even coating with the hydrated Ti02 and which can be taken UP per unit time :: tie avaiiaoie surface of the particles being coated. In principle, the anatase form: of TiQ2 forms o- tne surface of tne starting pigment. By adding small amounts of Sn02, however, it is possible tc force the rutiie structure to be formed. For example, as described in WO 93/0823". tin dioxide can be deposited before titanium dioxide precipitation and the product coated with minium dioxioe can be calcined at from 800 to 900CC.
The TiO: car optionally oe reoucec by usual procedures: US-B-4,948,631 (NH3, 750-850 °C -, W083. r" 3 (rv, > 9X °2, or DE-A-19843014 (solid reduction agent, such as, for example, silicon, > 600 °C).

Where appropriate, an Si02 (protective) layer can be applied on top of the titanium dioxide layer, for which the following method may be used: A soda waterglass solution is metered in to a suspension of the materia! being coated, which suspension has been heated to about 50-100°C, especially 70-80cC. The.pH is maintained at from 4 to 10, preferably from 6.5 to £.5 by simultaneously adding 10 % hydrochloric acid. After addition of the waterglass solution, stirring is carried out for 30 minutes.
It is possioie tc obtain pigments that are more intense in colour and more transparent by applying, or top of the Ti02 layer a metal oxide of "low" refractive index, that is to say a refractive index smalier than about 1.65, such as Si02, Ai203, AIOOH, B2O3 or a mixture thereof, preferably Si02, and applying a further Fe2C3 and/or Ti02 layer on top of the latter layer. Such multi-coated interference pigments comprising a silicon oxide substrate and alternating metal oxide layers of with high and low refractive index can be prepared in analogy to the processes described in WO9&'530-J and WO99/20695.
It is, in addrJon. possible to modify the powder colour of the pigment by applying further layers such as, for example, coloured metal oxides or Berlin Blue, compounds of transition metals, e.g.
Fe, Cu. Ni. Zz, Cn or organic compounds such as dyes or colour lakes.
ir, addition, re pigmen; according to the invention can also be coated with poorly soluble, firmiy adhering, inorganic or organic coiourants. Preference is given to the use of colour lakes anc. especially, ajminiurr: colour iaKes. For that purpose an aluminium hydroxide layer is precipitate'. . whicr- is, in a second step, lakec by using a colour lake (DE-A-24 29 762 and DE 29 28 287).
Furthermore tne piemen: according tc the invention may also have an additional coating witr complex sa!: elements, especially cyanoferrate complexes (EP-A-141 173 and DE-A-23 13 332;.
""0 enhance tne weatne- and iign: stability the muttiplayer silicon oxide flakes can be, depending c- the fieic 0' application, subjected to a surface treatment- Useful surface treatments £-£. for example, desonoed in DE-A-2215191, DE-A-3151354, DE-A-3235017, DE-A-333459S, DE-A-4C30727, EF-A-649886, WO97/29059, WO99/57204, and US-A-5;759,25£. Sad surraoe treatment night also facilitate the handling of the pigment, especially :ts incorporat c~ into va-ious aep:;oation media.
The SiOy flakes are prepared by a process comprising the steps (WO03/68868):

a) vapour-deposition o' a separating agent onto a (movable) carrier to produce a separating agent layer,
b) vapour-deposition of an SiOy layer onto the separating agent layer, wherein 0.70 s y s 1.8, c; dissolution of the separating agent layer in a solvent, and - -
d; separation of the SiO; frorr: tne solvent.
SfOvWith y > 1.0 car- be obtained by evaporation of SiO in the presence of oxygen. Layers, which are essentially free of absorption, can be obtained, if the growing SiOy layer is irradiated with UV light during evaporation (DE-A-1621214). It is possible to obtain SiO-,.5 layers, which do not aosorb in the visible region and have a refractive index of 1.55 at 550 nm, by so-called "reactive evaporation" of SiO in a pure oxygen atmosphere (E. Ritter, J. Vac. Sci. Techno!. 3 (1966) 225).
~~he SiOy layer in stec b; being vapour-deposited from a vaporiser containing a charge comprising a mixture of S\ anc Si02) SiOy or a mixture thereof, the weight ratio of Si to Si02 being preferably in the range from 0.15:1 to 0.75:1, and especially containing a stoichiometric mixture of Si and Si02 or c vaporiser containing a charge comprising silicon monoxide containing silicon in a-, amount up to 20 % by weight (0.70 £ y "ne silicon ex oe .aye: r step :. is formed preferably from silicon monoxide vapour produced in tne vaporise- by reaction of £ mixture of Si and Si02 at temperatures of more than 1300cC.
Tne vapour-cepcsition in steps i) and b) is carried out preferably under a vacuum of esoec;ai;v The separating agent vapour-deposited onto the carrier in step a) may be a lacquer (coating), a polymer, such as, for example, the (thermoplastic) polymers, in particular acryl-

or styrene polymers or mixtures thereof, as described in US-B-6,398,999, an organic substance soluble in organic solvents or water and vaporisable in vacuo, such as anthracene, anthraquhone, acetamidophenol, acetylsalicylic acid, camphoric anhydride, benzimidazole, benzene-',2.4-tricarboxylic acid, biphenyl-2,2-dicarboxylic acid, bis(4-nydroxyphenyl)sulfone, dihyaroxyanthraquinone, hydantoin, 3-hydroxybenzoic acid, 8-hydroxyquinoline-5-suifonic acid monohydrate, 4-hydroxycoumarinf 7-hydroxycoumarin, 3-nydroxynaphthaiene-2-ca'bcr/iic acid, isophthalic acid, 4,4-methylene-bis-3-hydroxy-naphthalene-2-carboxylic ace naphthalene-1,8-dicarboxylic anhydride, phthalimide and its potassium salt, phenolphthafein, phenothiazine, saccharin and its salts, tetraphenylmethane, triphenylene, triphenylmethanoi or a mixture of at least two of those substances. The separating agent is preferably an inorganic salt soluble in water and vaporisable in vacuo (see, for example, DE 198 44 357), such as sodium chloride, potassium chloride, lithium chloride, sodium fluoride, potassium fluoride, lithium fluoride, calcium fluoride, sodium aluminium fluoride and disodium tetraborate.
The movable carrier may consist of one or more discs, cylinders or other rotationally symmetrica: bodies, which rotate about an axis (cf. WO01/25500), and consists preferably of
one or mo'e continuous metai belts with or without a polymeric coating or of one or more poiyimide or oolyethyiene terephthalate belts (US-B-6,270,840).
Step d; may'comprise washino-out and subsequent filtration, sedimentation, centrifugation, decanting and'or evaporation. 7ne plane-parallel structures of SiOy may, however, also be frozen together with the soiven* in step d) and subsequently subjected to a process of freeze-dryinc. whereupon the soiven; is separated off as a result of sublimation below the triple Doint and the dry SiOy remains oehind in the form of individual plane-parallel structures.
~ns ihver/iic* re;ates aisc iz plane-parallel structures of SiOy that are obtainable by tnis method arc nave a thickness preferably in the range from 20 to 2000 nm, especially 20 tc
50C nm, mes: preferred 50 tc 350 nm.
Except unce' an ultra-high vacuum, in technical vacuums of a few 10*' Pa vaporised SiO always concenses as S»C\ wherein 1
On its further course, the beit-form carrier, which is closed to form a loop, runs through dynamic vacuum lock chambers of known mode of construction (cf. US-B-6,270,840) into a region of from 1 tc 5 x 1Q4 Pa pressure, preferably from 600 to 104 Pa pressure, and . especially from 10~ tc 5 x 1Cfc" Fa pressure, where it is immersed in a dissolution bath. The temperature of the solvent snouic be so selected that its vapour pressure is in the indicated pressure range. With mechanical assistance, the separating agent layer rapidly dissolves and the product layer breaks up into flakes, which are then present in the solvent in the form of a suspension. On its further course, the belt is dried and freed from any contaminants still adhering to it. It runs through a second group of dynamic vacuum lock chambers back into the vaporisation chamber, where the process of coating with separating agent and product iayer of SiO is repeated.
The suspension ther. present in both cases, comprising product structures and solvent, and the separating agent dissolved therein, is then separated in a further operation in accordance with a known technique. For that purpose, the product structures are first concentrated in the liquid and rinsec severa! times with fresh solvent in order to wash out the dissolved separating agent. The product, in the form of a solid that is still wet, is then separated off by filtration, sedimentation, cemrifugation, decanting or evaporation.
T.ne product ca^ the~ be brought to the desired particle size by means of ultrasound or by mechanical means using nigh-speed stirrers in a liquid medium, or after drying the fragments in an air-jet mil; having a rotary classifier, or means of grinding or air-sieving and delivered for further use.
h t.ne productior' o* the smcorvsiiicon oxide flakes, variants are possible:
It Is possible tc arrange severa; separating agent and product vaporisers one after the other in the running direction of the be!', r the vaporisation zone. By that means there is obtained, with little additional outlay in terms of apparatus, a layer sequence of S + P + S + P, wherein £ is the separating agent iayer and P is the product layer. If the number of vaporisers is doubled anc t.ne belt soeec is iT)e same, twice the amount of product is obtained.
Separating o~ tne piar»e-para!ie: structures after washing-out at atmospheric pressure can oe carried out under gentle conditions Dy freezing the suspension, which has been concentrated to a solids content of about 50 % and subjecting it in known manner to freeze-drying at

about -1QCC anc 50 Pa pressure. The dry substance remains behind as product, which can be subjected tc the steps of further processing by means of coating or chemical conversion.
instead of using a continuous celt, it is possible to produce the product by carrying out the steps o; vapour-depositior. o\ separating agent and SiO, of dissolution, and of drying the carrier, in an apparatus having a rotary body, in accordance with WO01/25500. The rotary
body may oe one or T;O~£ discs a cylinder or any other rotationally symmetrica! body.
The SiOy flakes may be cxitiisec using an oxygen-containing gas such as, for example, air at a temperature of at leas: 230°C, especially at above 400°C, preferably in the form of loose material, in a fluidised bee or by introduction into an oxidising flame, preferably at a temperature in the range from 500 to 1000°C, to form plane-parallel structures of SiOy
{WO03/068868}.
At present, i; can not be exciuded, that by heating TiCVSiOy particles at a temperature above £00 GC( especially 400 TC I 100°C, reduction of Ti02 by SiOy
TiO£ + SiOy -> SiOy+t + Ti02^
andor disp-oportionatio" c' SiCy in Si02 and Si occurs.
SiOv -r (y/y+a) SiOy+a + (1 - (y/y+a)) Si in this disproportion S'C,.-. f.akes are formed, containing (1 - (y/y+a)) Si, wherein 0.03 Tne fiakes of tne oresen: invention are not of a uniform shape. Nevertheless, for purposes of orevity, the fiakes wit: be referred to as having a "diameter." The SiOy flakes have a high Diane-para!ie::srr. anc a aefinec thickness in the range of ± 10 %, especially r 5 % o: the average thickness. The SiCv fiakes nave a thickness of from 20 to 2000 nm, especially from 2: ic 500 nm. most preferec 50 tc 350 nm. It is presently preferred that the diameter of the f.akes be in a oreferred range of about 1-50 nm with a mor^referred range of aboul 5-40 am. Thus, tne aspect ratio o*' the fiakes of tne present invention is in a preferred range of about 2 to 3000 with a more preferee' range of about 14 to 800. If a TiOr layer is depositee as a materia o; nigh refractive index, the Ti02 layer has a thickness of 20 to 200 nm:. especially 20 to : 00 nm, anc mora especially 20 to 50 nm. Due to the smaller thickness distribution of the SiOy flakes as compared to commercially available Si02 flakes effect pigments having a higher color purity result.

V. trie SiOy substrates of the present invention are used instead of mica flakes or Si02 substrates obtained according tc the process described in WO93/08237, interference pigments having superior brilliance, clear and intense colors, intense color flop, improved
color strength and color purity can be obtained. - ,
in another preferred embodiment of the present invention the SiOy flakes have a thickness of from 20 tc 200 nm, especially from 40 to 150 nm, most preferred 60 to 120 nm. The SiCy fiakes have a high piane-paraiieiism and a defined thickness in the range of ± 30 %, especially = 10 % of the average thickness. It is presently preferred that the diameter of the flakes be in a preferred range of about 1 to 60 \xm, especially 2 to 50 nm, with a more preferred range of about 5-40 urn. Thus, the aspect ratio of the flakes of the present invention is in a preferred range of about 4 to 1250 with a more preferred range of about 42 tc 670. If a TiO: layer is deposited as a material of high refractive index, the Ti02 layer has a thickness of 20 to 200 nm, especially 50 to 200 nm. The total thickness of the Ti02-coated SiOy flakes is especially 150 to 450 nm. Starting, for example, from SiOy flakes (y = 1.4 to 1.8) having a thickness of 90 nm r 30 % it is possible to obtain red (ca. 73 nm), green (ca. 150 nrr.V or biue [ca. 130 nm) interference pigments by selecting the thickness of the Ti02 ieyer. Due i: the small thickness distribution of the SiOyflakes effect pigments result having a high coio- ounty. The SiOy fiakes may be oxidised using an oxygen-containing gas such as, to- exampie. ar at a temperature of at least 200°C, especially at above 400°C, preferably in the form of loose materia!, ir a fiuidised bed or by introduction into an oxidising flame, preferably a: a temperature ir the range from 500 to 1000°C, to form plane-parallel structures of S'Oz (WO03/063868;. Alternatively, the SiOy fiakes can be heated in an oxygen-free atmosphere'such as, to* example, argon and/or helium or under a vacuum of less than 13 Pa ' 0'* ~o- a*, a temperafjre o* a: ieast 400°C, especially at above 400°C, preferably in the *orrr of ioose materia!., in £ fiJiOised be6, preferably at a temperature in the range from 900 xz : :0C~C. tc Torrr. the silicon/silicon oxide flakes. Both the Si02 flakes as well as the siiicon/siiicor. cxide fiakes car. be used instead of the SiOy flakes as substrate for effect
Metallic or nor-metallic. inorganic piateiet-shaped particles or pigments are effect pigments, ■especially me;a' effect pigments or interference pigments), that is to say, pigments that, oesiaes imparling colou- tc a" app'ication medium, impart additional properties, for example angle dependency of the colour (flop), lustre (not surface gloss) or texture. On metal effect pigments, substantially oriented reflection occurs at directionally oriented pigment particles.

in the case o* interference pigments, the colour-imparting effect is due to the phenomenon of interference o*' light in thin, highly refractive layers.
The .-freer; pigments according tc the invention can be used for ail customary purposes, for example for colouring polymers in the mass, coatings (including effect finishes, including those for the automotive sectc; and printing inks (including offset printing, intaglio printing, bronzing anc flexocraphic phnting;, and also, for example, for applications in cosmetics, in ink-jet printing, for dyeing textiles, glazes for ceramics and glass as well as laser marking of papers and plastics. Such applications are known from reference works, for example ' industrielie Organische Pigmente" (W. Herbst and K. Hunger, VCH Verlagsgesellschaft mbH, Weinheirrv'New York, 2nd, completely revised edition, 1995). When the pigments according to the invention are interference pigments (effect pigments), tney are gonioenromatic and result in brilliant, highly saturated (lustrous) colours. They are accordingly ver> especially suitable for combination with conventional, transparent pigments, for example organic pigments sucn as, for example, diketopyrrolopyrroles, quinacridones, dicxazines, pe-yteries jsoindoiinones etc., it being possible for the transparent pigment tc have a simiie.- colour tc the effect pigment. Especially interesting combination effects are ootained, noweven in analogy tc, ?or example, EP-A-388 932 or EP-A-402 943, when the coiour of the vansparen; pigment and that of the effect pigment are complementary. "~ne pigments according tc the invention can be used with excellent results for pigmenting high moiecu.a' weight organic material
"ne hig- mo-ecu.ar weight organic material for the pigmenting of which the pigments or pigment compositions according tc the invention may be used may be of natural or synthetic origin. High moiecjia* weight organic materials usually have molecular weights of about from 1C:' TC \0S z ~-o D" eve- mce. ""hey may be, for example, natural resins, drying oiis; rupee-or casei^.. z- -.a:j-a; sucstanoes ceriveti therefrom, such as chlorinated rubber, oi'-modifiec ateyc resins. , iscose. ceiiuiose etners or esters, such as ethylceliuicse, celiulose acetate, ceiijicse prop'onate, celuiose acetooutyrate or nitrocellulose, but especially totally synthetic organic polymers : thermosetting plastics and thermoplastics), as are obtained by poiymerisatb- pciyconcensaticn or polyaddition. From the class of the polymerisation resins there may ce mentioned, especially, polyolefins, such as polyethylene, polypropylene or posy:sopjryie~e anc ais: suostitutec potyolefins. such as polymerisation products of viny; cnionoe, v;~: ^cetai- sye^e. atryionirriie, acryiic acid esters, methacrylic acid esters or butadiene, anc aiso copoiymerisation products of the said monomers, such as especially ABS or EVA.

From the series of the polyaddition resins and poiycondensation resins there may be mentioned, for example, condensation products of formaldehyde with phenols, so-called phenopiasts, and condensation products of formaldehyde with urea, thiourea or meiamine, so-called aminopiastsr.anc tne polyesters used as surface-coating resins, either saturated, such as aikyc resins, or unsaturates such as maieate resins; also linear polyesters and polyamides, DO;vurethanes or silicones.
"""->£ said hig.u molecular weicm compounds may be present singly or in mixtures, in the form Q:* clastic masses or melts. They may also be present in the form of their monomers or in the poiymerised state in dissolved form as film-formers or binders for coatings or printing inks, sucn as, for example, boiied linseed oil, nitrocellulose, alkyd resins, melamine resins and urea-formaldehvde resins or acrviic resins.
Depending on the intended purpose, it has proved advantageous to use the effect pigments or effect pigment compositions according to the invention as toners or in the form of preparations. Depending on tne conditioning method or intended application, it may be advantageous to add certain amounts of texture-improving agents to the effect pigment before or after the conditioning process, provided that this has no adverse effect on use of the effect pigments for colouring high molecular weight organic materials, especially povethyiene. Suitaoie agents are, especially, fatty acids containing at least 18 carbon atoms, tcr exampie stearic or behenic acid, or amides or metal salts thereof, especially magnesium salts, and ais: piasticisers waxes, resin acids, such as abietic acid, rosin soap, alkylphenois c aliphatic aicohois, such as stearyl alcohol, or aliphatic 1,2-dihydroxy compounds containing from £ to 22 carbon atoms, such as 1,2-dodecanedio!, and also . modified edrophonium maieate resins o: fumaric acid colophonium resins. The texture-improving agents are acdec in amounts of preferably from 0.1 to 30 % by weight, especially from 2 to * 5 % by 'weight, based on tne end product.
~ne .'effect- pigments according to tne invention can be addec in any tinctorialiy effective amcjn; :c tne mgn noiecjia: weight organic material being pigmented. A pigmented supstance composition comprising t high molecular weight organic materia! and from 0.01 tc SC % by weight, preferably from: 0.1 tc 30 % by weight, based on the high molecular weight organic materia., of an pigment according to the invention is advantageous. Concentrations o\ from : to 20% by weight, especially of about 10% by weight, can often be used in practice.
-\\Z' cor.cen::-a:;cns. :o- examoie tncse above 30% by weight, are usually in tne form c* concentrates ;*masterbatches"} whicn can be used as colorants for producing pigmented materials having a relatively low pigment content, the pigments according to the invention

having an extraordinarily low viscosity in customary formulations so that they can stilt be processed well.
For the purpose of pigmenting organic materials, the effect pigments according to the invention may be used singly, it is, however, also possible, in order to achieve different hues or colour effects, to adc any desired amounts of other colour-imparting constituents, such as white, coloured, black or effect pigments, to the high molecular weight organic substances in addition to the effect pigments according to the invention. When coloured pigments are usee in admixture with the effect pigments according to the invention, the total amount is preferably from 0.1 to 10 % by weight, based on the high molecular weight organic material. Especially high goniochromicity is provided by the preferred combination of an effect pigment according to the invention with a coloured pigment of another colour, especially of a complementary colour, with colorations made using the effect pigment and colorations made using the coloured pigment having, at a measurement angle of 10°, a difference in hue (AH*) of from 20 to 340, especially from 150 to 210.
Preferably, tne effect pigments according to the invention are combined with transparent coloured pigments, it being possible for the transparent coloured pigments to be present either in the same medium as the effect pigments according to the invention or in a neighbouring medium. An exampie of an arrangement in which the effect pigment and the coloured pigment are advantageously present in neighbouring media is a multi-layer effect coating.
The pigmenting of high moiecuia" weight organic substances with the pigments according to the invention is carried out. for example, by admixing such a pigment, where appropriate in the form o* a masteroatch. with the substrates using roll mills or mixing or grinding apparatuses. The pigmented material is then brought into the desired finai form using methods known per $e, sucr. as calendering, compression moulding, extrusion, coating, Douring or n ection moulding. Any additives customary in the plastics industry, such as piasttcisers. fibers or stabilisers, oar, be added to the polymer, in customary amounts, before or afte* hco'ooration of the pigment. In particular, in order to produce non-rigid shaped articles c TC -educe their brittieness. if is desirable to add plasticisers, for example esters of phosphoric ac;d; phthalic acta or seoacic acid, to the high molecular weight compounds prior to shaping.
For pigmem.ng coatings anc ormtinc inks, the high molecular weight organic materials and tne effect pigments accorofnc t: tne invention, where appropriate together with customary additives sucn as, for example, fillers, other pigments, siccatives or plasticisers, are finely dispersed or dissolved in the same organic solvent or solvent mixture, it being possible for the individual components to be dissolved or dispersed separately or for a number of

components tc De dissolved o* dispersed together, and only thereafter for all the components to be brought together.
Dispersing an effect pigment according to the invention in the high molecular weight organic material being pigmented, anc processing a pigment composition according to the invention, are preferably carriec out suojec; to conditions under which only relatively weak shear forces occur so that the effect pigment is not broken up into smaller portions. Plastics comprising the pigment of the invention in amounts of 0.1 to 50 % by weight, in particular C.5 tc 7 % by weight, in the coating sector, the pigments of the invention are employed in amounts of C.l tc 10 % by weight. In the pigmentation of binder systems, for example for paints and printing inks for intaglio, offset or screen printing, the pigment is incorporated into the printing ink in amounts of 0.1 to 50 % by weight, preferably 5 to 30 % by weight and in particular 8 tc 15 % by weight.
The colorations obtained, for example in plastics, coatings or printing inks, especially in coatings or printing inks, more especially in coatings, are distinguished by excellent properties, especially by extremely high saturation, outstanding fastness properties, high
color purity and hign goniochromicity.
Wnen the high molecular weight material being pigmented is a coating, it is especially a
speciality coathc, very especially an automotive finish.
The-effect pigments according to the invention are also suitable for making-up the lips or the
skin and for coiourinc the hair or tne naiis.
The invention accordingly relates also to a cosmetic preparation or formulation comprising
from G-0001 tc 9C % by weight o; a pigment, especially an effect pigment, according to the
Invention anc f-om 10 to 9S.999? % of a cosmetically suitable carrier material, based on the
iota! weight of the cosmetic preparation or formulation.
£ucn cosmetc preparations or formulations are, for example, lipsticks, blushers, foundations.
nai; varnishes and hair shampoos.
"The pigments may be usee singly or in the form of mixtures. It is, in addition, possible to use
pigments according tc the invention together with other pigments and/or colorants. for
example in coronations as Described hereinbefore or as known in cosmetic preparations.
Tne cosmetic preparations anc formulations according to the invention preferably contain the
oicment acceding tc trie invention ir an amount from 0.005 to 50 % by weight, based on the
total weight of the preparation.
Suitable carrier materials for the cosmetic preparations and formulations according to the
invention include the customary materials used in such compositions.

The cosmetic preparations and formulations according to the invention may be in the form of, for example, sticks, ointment creams, emulsions, suspensions, dispersions, powders or solutions. They are, for exempt, lipsticks, mascara preparations, blushers, eye-shadows, foundations, evelne-r rowoer c nail varnishes.
It' the preparations are in tne form of sticks, for example lipsticks, eye-shadows, blushers or foundations, the preparations consist for a considerable part of fatty components, which may consist of one c~ nee -.•axes. 'c- example ozokerite, lanolin, lanolin alcohol, hydrogenated lanolin, acetyiated lanolin, lanoim wax, beeswax, candelilla wax, microcrystalline wax, carnauba wax. cetyl aicoho:. stearyl alcohol, cocoa butter, lanolin fatty acids, petrolatum, petroleum jelly, mono-, di- or tn-glycerides or fatty esters thereof that are solid at 25°C, silicone waxes, such as metnyloctadecane-oxypolysiloxane and poly(dimethylsiloxy)-stearoxysiloxane, stearic acio monoethanolamine, colophane and derivatives thereof, such as glycol abietates anc giycero abietates, hydrogenated oils that are solid at 25°C, sugar glycerides anc olea:esT myristates. lanolates, stearates and dihydroxystearates of calcium, magnesium, zirconium anc aluminium.
The fatty component ma\ aisc consist, of a mixture of at least one wax and at least one oii, in which case tne following oils, for example, are suitable: paraffin oil, purcelline oil, perhyarosquaiene, sweet a;monc oil, avocado oil calophyllum oil, castor oii, sesame oil, ioiooa oi!. mineral oiis having a coiling point of about from 310 to 410°C, silicone oils, such as dimethylpoiysiicxane, iinoiey accnoi, linolenyl alcohol, oleyi alcohol, cereal grain oils, such as wneatgerm ol.: isop-opy. .a~o,a:e. isopropyl paimitate, isopropyl myristate, butyl myristate, cetyi myristate. hexaoec/ stea-ate. butyl stearate, decyl oieate, acetyl glycerides, octanoates anc oecanoates o: aiconois an: ooiyaicohols, for example of glycol and glycerol, ricinoleates of aicohois anc poiy&ioonois. for example of cetyl alcohol, isosteary! alcohol, isocetyl ianoiate, isooropy: adipaie ne>:y ;aurate and octy! dodecanol.
The :at~\' components r sue** cecarations in the form: of sticks may generally constitute u: tc 99.t* c/c D> weight o- tne i:;a weight of the preparation.
Tne cosmetic prepa-at:ons anc *crmulations according to the invention may additionally comprise runner constituents, such as, for example, glycols, polyethylene glycols, polypropylene glycols., monoalkanolamides, non-coloured polymeric, inorganic or organic fillers, preservatives. JV friters c- other adjuvants and additives customary in cosmetics, for example a natural or syntnetic o: carnally synthetic di- or tri-giyceride, a mineral oil, a silicone oi., a wax. a 'atty aiconc. c 3.-erre; aicoho! or ester thereof, a lipophilic functional cosmetic active ingredient, including sun-protection filters, or a mixture of such substances. A lipophilic functional cosmetic active ingredient suitable for skin cosmetics, an active ingredient composition or an active ingredient extract is an ingredient or a mixture of ingre-

dients that is approved for oermal or topical application. The following may be mentioned by
way of example:
active ingredients having t cleansing action on the skin surface and the hair; these include all substances the: serve to cleanse the skin, such as oils, soaps, synthetic detergents and solid suostances;
active ingredients having a deodorising and perspiration-inhibiting action: they include antiperspirants based on aluminium salts or zinc salts, deodorants comprising bactericidal or bacteriostatic deodorising substances, for example triclosan, hexachlorophene, alcohols and cationic substances, such as, for example, quaternary ammonium salts, and odour absorbers, for example "'Grillocin (combination of zinc ricinoleate and various additives) or triethyl citrate (optionally in combination with an antioxidant, such as, for example, butyl hydroxytoluene) or ion-exchange resins; active ingredients that offer protection against sunlight (UV filters): suitable active ingredients are filter substances (sunscreens) that are able to absorb UV radiation from sunlight and convert it into heat; depending on the desired action, the following light-protection agents are preferred: light-protection agents that selectively absorb sunburn-causing high-energy UV radiation in the range of approximately from 280 to 315 nm (UV-B absorbers) and transmit the longer-wavelength range of, for example, from 315 to 400 nm (UV-A range), as well as light-protection agents that absorb only the longer-wavelength radiation of the UV-A range of from 315 to 400 nm (UV-A absorbers); suitable light-protection agents are, for example, organic UV absorbers from the class of the p-aminobenzoic acid derivatives, salicylic acid derivatives, benzophenone derivatives, dibenzoylmethane derivatives, dipheny! acrylate derivatives, benzofuran derivatives, polymeric UV absorbers comprising one or more organosiiicon radicals, cinnamic acid derivatives, camphor derivatives, trianilino-s-triazine derivatives, phenyi-benzimidazoiesulfonic acid and salts thereof, menthyi anthraniiates, benzotriazoie derivatives, and/or an inorganic micropigment selected from aluminium oxide- or silicon dioxide-coated Ti02, zin: oxide or mica;
active ingredients against insects (repellents) are agents that are intended to prevent insects
products and lanolin for protection against aqueous solutions, film-forming agents, such as sodium alginate, triethanolamine alginate, polyacrylates, polyvinyl alcohol or cellulose ethers for protection against the effect of organic solvents, or substances based on mineral oils, vegetable oils or silicone oils as "lubricants" for protection against severe mechanical stresses on the skin;
moisturising substances: the following substances, for example, are used as moisture-controlling agents (moisturisers): sodium lactate, urea, alcohols, sorbitol, glycerof, propylene glycol, collagen, elastin and hyaluronic acid;
active ingredients having a keratoplasty effect: benzoyl peroxide, retinoic acid, colloidal sulfur and resorcinol;
antimicrobial agents, such as, for example, triclosan or quaternary ammonium compounds;
oily or oil-soluble vitamins or vitamin derivatives that can be applied dermally: for example vitamin A (retinol in the form of the free acid or derivatives thereof), panthenol, pantothenic acid, folic acid, and combinations thereof, vitamin E (tocopherol), vitamin F; essential fatty acids; or niacinamide (nicotinic acid amide);
vitamin-based placenta extracts: active ingredient compositions comprising especially vitamins A, C, E, Bi, B2, B6, B«2, folic acid and biotin, amino acids and enzymes as well as compounds of the trace elements magnesium, silicon, phosphorus, calcium, manganese, iron or copper;
skin repair complexes: obtainable from inactivated and disintegrated cultures of bacteria of the bifidus group;
plants and plant extracts: for example arnica, aloe, beard lichen, ivy, stinging nettle, ginseng, henna, camomile, marigold, rosemary, sage, horsetail or thyme; animal extracts: for example royal jelly, propolis, proteins or thymus extracts; cosmetic oils that can be applied dermally: neutral oils of the Miglyol 812 type, apricot kernel oil, avocado oil, babassu oil, cottonseed oil, borage oil, thistle oil, groundnut oil, gamma-oryzanol, rosehip-seed oil, hemp oil, hazelnut oil, blackcurrant-seed oii, jojoba oil, cherry-stone oii, salmon oil, linseed oil, cornseed oil, macadamia nut oil, almond oil, evening primrose oil, mink oil, olive oil, pecan nut oil, peach kernel oil, pistachio nut oil, rape oil. rice-seed oil, castor oil, safflower oil, sesame oil, soybean oil, sunflower oil, tea tree oii, grapeseed oii or wheatgerm oil.
The preparations in stick fornn are preferably anhydrous but may in certain cases comprise a certain amount of water which, however, in general does not exceed 40 % by weight, based on the total weight of the cosmetic preparation.

If the cosmetic preparations and formulations according to the invention are in the form of semi-solid products, that is to say in the form of ointments or creams, they may likewise be anhydrous or aqueous. Such preparations and formulations are, for example, mascaras, ~ eyeliners, foundations, blushers, eye-shadows, or compositions for treating rings under the eyes.
If, on the other hand, such ointments or creams are aqueous, they are especially emulsions of the water-in-oil type or of the oil-in-water type that comprise, apart from the pigment, from 1 to 98.8 % by weight of the fatty phase, from 1 to 98.8 % by weight of the aqueous phase and from 0.2 to 30 % by weight of an emulsifier.
Such ointments and creams may also comprise further conventional additives, such as, for example, perfumes, antioxidants, preservatives, gel-forming agents, UV filters, colorants, pigments, pearlescent agents, non-coloured polymers as well as inorganic or organic fillers. If the preparations are in the form of a powder, they consist substantially of a mineral or inorganic or organic filler such as, for example, talcum, kaolin, starch, polyethylene powder or polyamide powder, as well as adjuvants such as binders, colorants etc.. Such preparations may likewise comprise various adjuvants conventionally employed in cosmetics, such as fragrances, antioxidants, preservatives etc..
If the cosmetic preparations and formulations according to the invention are nail varnishes, they consist essentially of nitrocellulose and a natural or synthetic polymer in the form of a solution in a solvent system, it being possible for the solution to comprise other adjuvants, for example pearlescent agents.
In that embodiment, the coloured polymer is present in an amount of approximately from 0.1 to 5 % by weight.
The cosmetic preparations and formulations according to the invention may also be used for colouring the hair, in which case they are used in the form of shampoos, creams or gels that are composed of the base substances conventionally employed in the cosmetics industry and a pigment according to the invention.
The cosmetic preparations and formulations according to the invention are prepared in conventional manner, for example by mixing or stirring the components together, optionally with heating so that the mixtures melt.
The Examples that follow illustrate the invention without limiting the scope thereof. Unless otherwise indicated, percentages and parts are percentages and parts by weight, respectively.
Examples

example
in a vacuum system which n its fundamental points is constructed analogously to the system described ir. 115-5-6,270,5^0, the following are vaporised, from vaporisers, in succession: sodium chloride (Nad) as separating agent at about 900°C, and silicon monoxide (SiO) as reaction product ol 5. ana Si02 at trom 1350 to 1550°C. The layer thickness of NaCi is typically 30-50 nm., that of SiOy being, depending on the intended purpose of the end product, from 100 tc 2000 nm. in *ne present case 200 nm. Vaporisation is carried out at about 0.02 Pa, amounting to about 11 g of Nad and 72 c of SiO per minute. For subsequently detaching the layers by dissolution of the separating agent the carrier on which vapour-deposition has taken place is sprayed at about 3000 Pa with deionised water and treated with mechanical assistance using scrapers and with ultrasound. Tne NaCi dissolves and the SiOy layer, which is insoluble, breaks up into flakes, Tne suspension is continuously removed from the dissolution chamber and, at atmospheric pressure, is concentrated by filtration and rinsed several times with deionised water
in order to remove Na~ and 3" ions that are present. That is followed by the steps of drying and heating the plane-parallel SiCX structures in the form of loose material at 500 to 600°C for two hours in an oven through which air heated to 500 to 600°C is passed. After cooling, comminution
and grading by ar-sieving are camiec out.
Seispie! 2
"wc Layer System
* TiO? Layer-
:00 g ol the SiC, f.aKes octanec ir. example 1 are suspended in 1,5 I fully deionized water ano heated tc " £D. To tnis suspension 160 ml of an aqueous solution of TiCL (400 g TiCL-1; is rnetereo witn:n 90 minutes. Tne or is kept constant at pH=2.2 by means of 32% sodium hydrcxioe solution. After tnis soL'tio- nas been added, the mixture is stirred for a further
2 SiC-Level
Tne pK of the suspension, is increased by means of sodium hydroxide solution to 7,5 and within 3.5 hou-s 720 m! a sodiu~ water glass solution is metered (125 g SiCyi) at 75 °C. Dunne tne aod :;on the pr is kept constant by means of 10% hydrochloric acid. After this solution has Pee" adoec. the m;x:u*e is stirred for a further 30 minutes at 75 °C "he tnus ootarec oigmem is cna'acterized intense blue interference color.
Example 3
3 Layer System comprising a Fer03 Layer
1) TiO? Layer:

The Ti02 layer is obtained as described in Example 1.
2) SiO? Layer:
The Si02 layer is obtained as described in Example 1,
3) Fe?Q, Layer:
The pH of the suspension of the silicon oxide flakes coated succesively with Ti02 and Si02 is controlled by means of 10% hydrochloric acid to 3.0. Then 1750 ml of an aqueous FeClr Losung (35 g Fe/I) are added at 75 °C within 5 h. The pH is kept constant by simultaneously adding 32% NaOH. After this solution has been added, the mixture is stirred for a further approximately 45 minutes at 75 °C. After the suspension has cooled to room temperature, the product is filtered, washed saltfree with water and dried at 110 °C. Then the pigment is calcinated 30 minutes at 850 °C.
Example 4
250 mg of 295 nm thick SiOv (y - 1.7-1.8) flakes (average diameter - 50 microns), which have a green color on a black background, are mixed in 35 ml deionized water and then heated to 60°C. The pH is adjusted to 1.4with 1N hydrochloric acid. 10 ml of TiOCI2 (diluted w'rth 1N HCI, such that the solution comprises 1.5 % of titanium) are added to the solution during 5-.hours, while maintaining the pH at 1.4 by continuous addition of sodium hydroxide. The liquid is cooled to room temperature and filtered with a 20 micron sieve. The obtained powder is dried for 1 hour at 60°C in air. White looking flakes are obtained which have a bright blue color when viewed on a black background. The color depends on the observation angle and turns violet and then yeliow when increasing the viewing angle.

Claims
1. A pigment, the particles of which generally have a length of from 2μ m to 5 mm, a width
of from 2 urn to 2 mm, and a thickness of from 20 nm to 2 μm, and a ratio of length to
thickness of at least 2:1, wherein the particles contain a core of SiOy with 0.70 1.95, especially 1.1 2. The pigment, the particles of which generally have a length of from 2 μm to 5 mm, a
width of from 2 μm to 2 mm, and a thickness of from 20 nm to 2μm, and a ratio of
length to thickness of at least 2:1, wherein the particles contain a core of SiOy with
0.70 distance between which is the shortest axis of the core, comprising
(a) a thin semi-transparent metal layer.
3. The pigment according to claim 1, wherein the pigment comprises in addition (b) a metal
oxide of low refractive index, wherein the difference of the refractive indices is at least
0,1.
4. The pigment according to claim 1 or 3, wherein the metal oxide of high refractive index is
TiC2, Zr02t Fe2Q5, Fe304, Cr203, ZnO or a mixture of these oxides or an iron titanate, an
iron oxide hydrate, a titanium suboxide or a mixture and/or mixed phase of these
compounds.
5 The pigment according tc any of claims 1,3, or 4, wherein the metai cxide of low index of refraction is Si02, Ai2Os. AIOOH, Bo03, or a mixture thereof, wherein alkali or earth alkali metal oxides can be contained as additional component.
6. The pigment according to any of claims 1 to 5, wherein the SiOy core nas a thickness of from 20 tc 200 nm, especially from 50 to 150 nm, most preferred 6C to 120 nm.
7. A process for producing the interference pigment according to any of claims 1 and 3 to 6, by alternately coating SiOy flakes with a metal oxide with a high refractive index and a metal oxide with a low refractive index in a wet process by hydrolysis of the

corresponding water-soluble metal compounds, by separating, drying and optionally calcinating the pigment thus obtained.
8. A process for producing the pigment according to claim 2, wherein SKDy flakes are
suspended in an aqueous and/or organic solvent containing medium in the presence
of a metal compound and the metal compound is deposited onto SiOy flakes by
addition of a reducing agent.
9. A pigment, the particles of which generally have a length of from 2 μm to 5 mm, a width
of from 2 μm to 2 mm, and a ratio of length to thickness of at least 2:1, wherein the
particles contain a core of Si02or a silicon/silicon oxide core obtainable by heating SiOy
flakes with 0.70 temperature of at least 400°C, having two substantially parallel faces, the distance
between which is the shortest axis of the core, comprising
a material, especially a metal oxide, having a high index of refraction, or
a thin semi-transparent metal layer and optionally further layers, wherein
the core has a thickness of from 20 to 200 μm, especially from 40 to 150 nm, most
preferred 60 to 120 nm.
10. Use of the pigments according to any of claims 1 to 6 or 9 in paints, ink-jet printing, for
dyeing textiles, for pigmenting coatings, printing inks, plastics, cosmetics, glazes for
ceramics and glass.
11. Paints, printing inks, plastics, cosmetics, ceramics and glass, which are pigmented
with a pigment Pigment according to any of claims 1 to 6 or 9.

Documents:

919-chenp-2005 abstract-duplicate.pdf

919-CHENP-2005 ABSTRACT.pdf

919-CHENP-2005 CLAIMS GRANTED.pdf

919-chenp-2005 claims-duplicate.pdf

919-CHENP-2005 CORRESPONDENCE OTHERS.pdf

919-CHENP-2005 CORRESPONDENCE PO.pdf

919-chenp-2005 description (complete)-duplicate.pdf

919-CHENP-2005 FORM 1.pdf

919-CHENP-2005 FORM 3.pdf

919-CHENP-2005 PETITIONS.pdf

919-CHENP-2005 POWER OF ATTORNEY.pdf

919-chenp-2005-abstract.pdf

919-chenp-2005-claims.pdf

919-chenp-2005-correspondnece-others.pdf

919-chenp-2005-correspondnece-po.pdf

919-chenp-2005-description(complete).pdf

919-chenp-2005-form 1.pdf

919-chenp-2005-form 18.pdf

919-chenp-2005-form 3.pdf

919-chenp-2005-form 5.pdf

919-chenp-2005-pct.pdf

« Previous Patent

Next Patent »

Patent Number

222681

Indian Patent Application Number

919/CHENP/2005

PG Journal Number

47/2008

Publication Date

21-Nov-2008

Grant Date

20-Aug-2008

Date of Filing

13-May-2005

Name of Patentee

CIBA SPECIALTY CHEMICALS HOLDING INC

Applicant Address

KLYBECKSTRASSE 141, CH-4057 BASEL,

Inventors:

#	Inventor's Name	Inventor's Address
1	BUJARD, PATRICE	OBERER REBBERGWEG 29, CH-4153 REINACH,
2	LEYBACH, HOLGER	AM PLATZ 15, 79689 MAULBURG,

PCT International Classification Number

C09C /00

PCT International Application Number

PCT/EP03/11077

PCT International Filing date

2003-10-07

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	02406009.7	2002-11-21	EUROPEAN UNION
2	02405887.7	2002-10-16	EUROPEAN UNION