Title of Invention	A METHOD OF PRODUCING A COLOURED ENGINEERING PLASTIC BASED ON POLYAMIDE
Abstract	PL/2-23557Abstract Engineering plastics, especially polyamide, are coloured with improved fastness and stability properties using pigment compositions comprising an organic pigment wholly overlaid with a crosslinked (meth)acryiic resin or copolymer ■■ thereof. Preference is given to the use of diketopyrrolopyrrole, azo, pteridine, i\| isoindoline and isoindolinone pigments. Processes for the preparation of the pigment compositions are also claimed. !i

Title of Invention

A METHOD OF PRODUCING A COLOURED ENGINEERING PLASTIC BASED ON POLYAMIDE

Abstract

PL/2-23557Abstract Engineering plastics, especially polyamide, are coloured with improved fastness and stability properties using pigment compositions comprising an organic pigment wholly overlaid with a crosslinked (meth)acryiic resin or copolymer ■■ thereof. Preference is given to the use of diketopyrrolopyrrole, azo, pteridine, i| isoindoline and isoindolinone pigments. Processes for the preparation of the pigment compositions are also claimed. !i

Full Text	Heat-stable encapsulated pigments i The present invention relates to novel pigment compositions, to processes for the preparation thereof and to the use thereof for producing coloured engineering plastics (thermoplastics that maintain dimensional stability and most mechanical properties above 100°C or below 0°C), especially those based on polyamide. Mass-colouring of polymer processed at high temperatures, such as engineering plastics and in particular polyamides is usually carried out using so-called solvent dyes, which are soluble in the polyamide mass at high processing temperatures and which, besides having the requisite high heat resistance, also have adequate chemical stability with respect to, for example, the highly reductive medium of the polyamide melt. However, soluble dyes generally have much poorer ji lightfastness, as compared with pigments. ■\|i ji The use of pigments in such polymers is restricted almost exclusively to inorganic i\| pigments, most of which contain heavy metals, and to a very small selection of specific organic pigments, mainly from the phthalocyanine or quinacridone class. Inorganic pigments, however, have generally low chroma and low colour \| strength. Organic pigments have disadvantages such as crystal phase and colour changes, migration, a frequent tendency of the coloured materials to fluoresce, and often a reactive interaction with the polymer, leading to degradation of the pigment and/or deterioration of the polymer's mechanical properties. (j ii ,i There is therefore a need for new colourants which in mass-coloured engineering j! plastics processed at high temperature result in highly saturated, strongly ;i coloured, non-fluorescent colourations that are light-fast and have high- J il temperature stability, and which exhibit good allround fastness properties, without affecting negatively the physical properties of the polymeric material. j i. FR1 551 400 and EP 0046 729 disclose azopyrimidine colourants. EP 0 061'426 discloses diketopyrrolopyrrole pigments. WO 98/18 866 discloses pteridine\| pigments. US 3,826,670 discloses encapsulated pigments with an intermediate ionically crossiinked polymeric salt and a skin consisting essentially of dense, amorphous, hydrated oxide or hydroxide of silicon, titanium or zirconium. EP 0 744448 discloses pigments suitable for stencil inks, which are encapsulated in a polymeric matrix obtained from the reaction of polyisocyanates with polyols. WO 2006/089 933 discloses aqueous dispersions comprising pigments that are at least partially sheathed in radiation-curable polyurethane, their production and use especially for inkjet printing. US 5,905,111 discloses a continuous process for preparing acrylate based pigment preparations. However, such pigment preparations do not provide satisfactory results in engineering plastics. US 6,800,127 discloses pigment preparations comprising polyamide particles with an average size of below 50j.im and an average pigment size below 0.2 \xm. However, especially the fastness properties are still not fully satisfactory. WO 06/111 493 is a patent application according to Art. 54(3) EPC and Rule 64.3 PCT, which is directed to pigments encapsulated by polymers which are not crossiinked. It has now been found that the pigment compositions according to the invention surprisingly meet the above-mentioned criteria to a larger extent. The present invention accordingly relates to a pigment composition comprising solid particles, which particles comprise from 20 to 75% by weight of an organic pigment and from 80 to 25% by weight of a crossiinked polymer, preferably from 25 to 60% by weight of an organic pigment and from 75 to 40% by weight of a crossiinked polymer, each based on the total weight of the solid particles, wherein the surface of the solid particles consists essentially of the crossiinked polymer and the crossiinked polymer is obtainable from a crosslinking agent and a prepolymer of average molecular weight Mw from 2000 to 200000, preferably 3 epoxy or primary or secondary amino groups or (b2) unsaturated bonds, wherein Ri is H, CrC4alkyl, C2-C4a!kenyl or COOR5, R2 and R3 are independently from one another H, OR6, NHR6, Ci-C4alkyl or C2-C4alkenyl, R4, R5 and R6 are independently from one another H, unsubstttuted CrC6alkyl or C2-C6aikenyi, or C2-C6alkyl or C2-C6alkenyl each substituted by one or more hydroxy and/or epoxy groups, and n is a number from 2 to 2000, preferably from 5 to 1500. The organic pigment is either directly embedded in the crosslinked polymer, or it is chemically or physically surface-modified or encapsulated, for example with a pigment derivative, a polymer or a layer of one or more transition metal oxides adsorbed on or bound to its surface. However, the pigment and any optional additional components should be fully surrounded by crosslinked polymer, as the surface of the solid particles should consist essentially of the crosslinked polymer, in order the desired properties to be obtained. The prepolymers are most suitably homo- or copolymers based on unsaturated monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and their derivatives, such as esters and amides thereof and maleic acid anhydride, which monomers may be copolymerized with less polar monomers such as vinyl chloride, vinyl alcohol or preferably styrene. Preferably, the prepolymers comprise at least 30% by weight of repeating blocks of formula (I). These prepolymers are crosslinked with any known crosslinking agent, for example reactive crosslinking agents such as polyisocyanates, polyhydrazides, polycarboxylic acids, polyoxazolines, polyaziridines, polyepoxides, polysulfonazides, poiyketimines, melamine-formaldehyde resins, urea-formaldehyde resins, or with crosslinking agents forming salts for example with carboxy groups of the prepolymer, such as polyamines or metal ions. Polyfunc- 4 tional crosslinking agents comprise generally from 2 to 10, preferably 2, 3 or 4, especially 2 functional groups. A particularly preferred aspect of the invention, however, is the use of self crosslinking prepolymers, which comprise both crosslinkable and crosslinking groups such as described above. The crosslinkable and crosslinking groups may be on the same backbone, optionally as blocks of a copolymer, or also on different backbones imbricated together. Suitable prepolymers are known and a large choice thereof is available commer¬cially, too. Suitable prepolymers are for example disclosed in WO 01 /74 735. Commercially available self crosslinking prepolymers are for example Acronal® LR 8977, Acronal® S 760 na (both BASF AG, Ludwigshafen/DE) and Glascol® C 44 (CIBA Specialty Chemicals Inc.). The amount of crosslinking agent is generally from 1 to 25% by weight, based on the amount of prepolymer. When the crosslinking agent is separately added to the prepolymer, its amount is preferably from 2 to 20% by weight, most preferably from 3 to 10% by weight, based on the amount of prepolymer. When the crosslinking agent is physically comprised in a self crosslinking prepolymer, its amount is preferably from 1 to 20% by weight, most preferably from 4 to 10% by weight, based on the amount of prepolymer. When the crosslinking agent is part of a self crosslinking prepolymer backbone, the amount of monomers comprising self crosslinking groups used to make the prepolymer is preferably from 1 to 20% by weight, most preferably from 4 to 10% by weight, based on the total amount of monomers used to make the prepolymer. Crosslinking reactions are known in the art of coatings (see for example Ullmann's Encyclopedia of Industrial Chemistry, Paints and Coatings, 2. Types of Paints and Coatings (Binders), Wiley-VCH Verlag GmbH & Co. KGaA, 6th Edition 2002). The crosslinking reaction can take place simply at room temperature, such as in the case of aqueous acrylic prepolymer dispersions to which bishydrazides or aziridines are subsequently added, or at elevated temperature, such as from I i 50 to 300°C, especially from 130 to 200°C, optionally in the presence of a jj suitable catalyst, for example acids, metal compounds, amines, ammonium'or hydroxy ions, such as hydrochloric acid, dibutyl tin laurate, triethylamine or j- tetrabutylammonium iodide. \| i i! ii The instant pigment compositions generally comprise pigment particles having a size of from 0.01 to 10 ^m, preferably up to 5 jam, most preferred from 0.05 to 2 ]im, especially from 0.1 to 1 \|.im. The capsules comprising the pigment ll preferably have an average volume from 10"20 to 10~8 m3, especially from 10~18 to 10"10m3. \| i The instant pigment compositions comprise adequately from 0 to 20% by weight of other components, preferably from 0 to 3% by weight of volatile components, most preferred up to 2% by weight of volatile components, based on the total pigment composition. The volatile components preferably consist of organic-! solvents or water, most preferred water. Any organic pigment can be used, for example diketopyrrolopyrrole, quinacrido-ne, azo, quinophthalone, phthalocyanine, indanthrone, flavanthrone, pyranthrone, anthraquinone, perylene, dioxazine, perinone, thioindigo, isoindolinone, isoindoline, pteridine and metal complex pigments. However, preference is given to the use of diketopyrrolopyrrole, azo, pteridine, isoindoline and isoindolinone pigments, especially 'v wherein R7 and R8 are each independently of the other a group of formula j naphthyl which are each unsubstituted or substituted by halogen, OH, NH2l i Ci-C4alkyl or CrC4alkoxy, preferably NH2, OH, hydrogen, methyl, ethyl, NHCOR37, NHCOOR37, NHCONHR37, NHCONR36R37 or phenyl which is ;, unsubstituted or substituted by OH or NH2, most preferred NH2, OH, hydrogen, methyl, NHCOR37 or phenyl which is unsubstituted or substituted by NH2) wherein R3e is Ci-C4alkyl; phenyl which is unsubstituted or substituted by halogen, i] Ci-C4a)kyl or d-C4-alkoxy, COR37, COOR37 or CONHR37; and j] R37 is Ci-C4alkyl or phenyl which is unsubstituted or substituted by halogen/1 Ci-C4alkyl or Ci-C4-alkoxy, preferably Ci-C4alkyl or phenyl which is unsubstituted or substituted by chloro, methyl, ethyl, methoxy or ethoxy, most preferred methyl, ethyl or phenyl, with the proviso that at least two of the radicals R32, ^33, R34,and R35 are NH2 or OH, most preferred wherein R32 and R35 are identical, and R33 and ;L R34 are identical and at least one of the pairs R32 and R35 or R33 and R34 is N'H2 or OH; \|\| trimethylcyclohexyl, menthyl, thujyl, bornyl, 1-adamantyl or 2-adamantyl. C2-Ci2Alkenyl or C3-Ci2cycloalkenyl is respectively C2-C12alkyl or C3-Ci2cycloalkyl that is mono- or poly-unsaturated, wherein two or more double bonds may be isolated or conjugated, for example vinyl, allyl, 2-propen-2-yl, 2-buten-1 -yl, 3-buten-1-yl, 1,3-butadien-2-yl, 2-cyclobuten-1-yl, 2-penten-1-yl, 3-penten-2-yl, 2-methyl-1-buten-3-yl, 2-methy!-3-buten-2-yl, 3-methyl-2-buten-1-yl, 1,4-pentadien-3-yl, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl, 3-cyclohexen-1-yl, 2,4-cyclohexadien-1-yl, 1-p-menthen-8-yl, 4{10)-thujen-10-yl, 2-norbornen-1-yl, 2,5-norbornadien-1 -yl, 7,7-dimethyl-2,4-norcaradien-3-yl or the various isomers of hexenyl, octenyl, nonenyl, deceny! ordodecenyl. The pigments preferably have a specific surface area of from 10 to 150 rn2/g. Special preference is given to opaque pigments having a specific surface area of from 12 to 50 m2/g and to transparent pigments having a specific surface area of from 50 to 100 m2/g. The instant pigment compositions are suitably prepared by dispersing the pigment and the prepolymer in an inert liquid medium, such as an organic solvent or preferably water, then crosslinking the prepolymer by addition of a crosslinking agent, addition of a crosslinking catalyst and/or heating. The instant pigment compositions are then preferably isolated by filtration and dried. Alternatively, it is also possible to isolate and optionally dry the dispersion of pigment in the prepolymer, optionally also comprising a thermally crosslinking agent, and then only to perform crosslinking by heating. Crosslinking, or optionally the final part of crosslinking, can also be effected upon final processing of the engineering plastic to be coloured. The pigment and the prepolymer can be dispersed together, or the pigment can be dispersed in a dispersion or solution of the prepolymer, or the prepolymer can be dispersed or dissolved in a dispersion of the pigment, or the prepolymer can be prepared by emulsion or suspension polymerisation in presence of the 14 pigment, for example by adding the pigment to the polymerisable monomer or mixture of monomers before the subsequent polymerisation reaction. The present invention also relates to a method of producing a coloured engineering plastic, wherein an engineering plastic and a tinctorially effective amount of at least one pigment composition according to the invention are processed together at a temperature of 200°C or above, preferably from 220 to 350°C, most preferred from 240 to 330°C. Generally, the amount of instant pigment composition will be from 0.001 to 70% by weight, based on the total weight of the engineering plastic and instant pigment composition. Preferred are in the case of coloured items from 0.01 to 10% by weight, and in the case of masterbatches from 30 to 60% by weight, each based on the total weight of the engineering plastic and instant pigment composition. The engineering plastics to be colored with the instant pigment compositions are generally polymers having a molecular weight in the range of from 104to108g/mol. Colouring the engineering plastics with the pigment composition according to the invention is carried out, for example, by mixing such a pigment composition into the substrates using roll mills or mixing or grinding apparatuses, as a result of which the pigment composition is finely distributed in the engineering plastic. The high engineering plastic comprising the admixed pigment composition is then processed by methods known perse, such as calendering, compression moulding, extrusion, spread-coating, melt-spinning, casting or by injection moulding, whereby the coloured material acquires its final shape. Admixture of the pigment composition can also be effected immediately prior to the actual processing step, for example by continuously feeding a solid, for example pulverulent, pigment composition and, at the same time, a granulated or powdered engineering plastic, and optionally also additional ingredients such as, for example, additives, directly into the intake zone of the processing equipment, where mixing takes place immediately before processing. Crosslinking may also be effected or completed at this stage. Generally, however, it is preferable to mix 15 me pigment composition into the engineering plastic beforehand, since more uni¬formly coloured products can be achieved. Remarkably, the instant pigment compositions largely retain their structure upon processing, so that the instant crosslinked polymer remains around the pigments, thus preventing a direct contact between the pigment and the engineering plastic. The instant pigment compositions also have an excellent compatibility with engineering plastics. In order to produce non-rigid mouldings or to reduce their brtttleness, it is possible to incorporate so-called plasticisers into the engineering plastics prior to shaping. There may be used as plasticisers, for example, esters of phosphoric acid, phthalic acid or sebacic acid. In the method according to the invention, the plasticisers may be incorporated into the polymers before or after incorporation of the colorant. It is also possible, in order to achieve different colour shades, to add to the engineering plastics, in addition to the pigment composition according to the invention, further pigments or other colorants in any desired amounts, optionally together with further additional ingredients such as, for example, fillers or siccatives (drying agents). On the other hand, it is sometimes desirable to increase the rigidity and/or solidity, for example by incorporating glass fibers or other known reinforcing agents. Preferred engineering plastics suitable for colouring in accordance with the invention are very generally polymers having a dielectric constant >2.5 at 20°C, preferably polyester (e.g. PET), polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), polyamide, polyethylene, polypropylene, styrene/acrylonitrile (SAN) or acrylonitrile/butadiene/styrene (ABS). Special preference is given to polyester and very special preference is given to polyamide, for example polyamide 6, polyamide 6.6, polyamide 12 and aramid. The pigment compositions according to the invention are well dispersible in the 16 Examples 4-6: Test plates made of polyamide 6 (Ultramid® B3K, BASF) ■ i! containing 0.2% of the encapsulated pigments according to examples 1-3 are i prepared by injection molding from a pre-concentrate compounded in a twin- ii screw extruder. The processing temperatures are between 240 and 300QC. So produced test plates show excellent temperature and light stability, as well as excellent wash stability, no migration of the colorants and no fluorescence, j 18 Claims: 1. A pigment composition comprising solid particles, which particles comprise from 20 to 75% by weight of an organic pigment and from 80 to 25% by weight of a crosslinked polymer, preferably from 25 to 60% by weight of an organic pig¬ment and from 75 to 40% by weight of a crosslinked polymer, each based on the total weight of the solid particles, wherein the surface of the solid particles ;; consists essentially of the crosslinked polymer and the crosslinked polymer is obtainable from a crosslinking agent and a prepolymer of average molecular amino groups or (b2) unsaturated bonds, wherein R, is H, C1-C4alkyl, !! C2-C4alkenyl or COOR5, R2 and R3 are independently from one another H, 0,R6, NHR6l Ci-C4alkyl or C2-C4alkenyl, R4, R5 and R6 are independently from one another H, unsubstituted Ci-C6alkyl or C2-C6alkenyl, or C2-C6alkyl or C2-C6alkenyl each substituted by one or more hydroxy and/or epoxy groups, and n is a number from 2 to 2000, preferably from 5 to 1500. \|! it R9 and R10 are each independently of the other hydrogen, halogen, Ci-C24alkyl, imidazolyl, pyrazolyl, triazolyl, piperazinyl, pyrrolyl, oxazolyl, benzoxazolyl, i benzothiazolyl, benzimidazolyl, morpholinyl, piperidinyl or pyrrolidinyl, preferably hydrogen, halogen, cyano, carbamoyl, nitro, trifluoromethyl, phenyl, CrC6all Ci-C6alkoxy, CrC6alkylthio or C,-C6atkylamino; ; i i R11 and R12 are each independently of the other hydrogen, halogen or Ci-C6alkyl; ij R13 is -CH2-, -CH(CH3)-, -C(CH3)2-, -CH=N-, ~N=N-, -0-, -S-, -SO-, -S02-, NH;\|or -NCi-C6alkyl-;and \| i! R14 and R15 are each independently of the other hydrogen, halogen, Ci-C6alkyl, j li i wherein R16, R17 and RIB are independently from one another hydrogen; j Ci-C6alkyl, C3-C6cycloalkyl, benzyl or phenyl each unsubstituted or substitute^ by halogen, OH, OR26l COR26, SR26) S02R26, SO3R26, CN, COOH, COO"+Mi, jj . COOR26, CONH2l CONHR26 or CONR26R27, preferably Ri6, R17 or Ri8 are 20 unsubstituted or substituted by OH or NH2, most preferred NH2l OH, hydrogen, methyl, NHCOR37 or phenyl which is unsubstituted or substituted by NH2, wherein !] R36 is CrC4alkyl; phenyl which is unsubstituted or substituted by halogen, \| Ci-C4alkyl or CrC4-alkoxy, COR37, COOR37 or CONHR37; and \R37 is CrC4alkyl or phenyl which is unsubstituted or substituted by halogen, ii CrC4alkyl or CrC4-a!koxy, preferably d-C4alkyt or phenyl which is unsubstituted or substituted by chloro, methyl, ethyl, methoxy or ethoxy, most preferred methyl, il ethyl or phenyl, with the proviso that at least two of the radicals R32, R33, R34 and R35 are NH2 or OH, most preferred wherein R32 and R35 are identical, and R33 and R34 are identical and at least one of the pairs R32 and R35 or R33 and R34 is NH2-or OH; j! 3. A pigment composition according to claims 1 or 2, wherein the prepolymer is selected from the group consisting of homo- or copolymers based on unsaturated monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and their derivatives, such as esters and amides thereof and maleic acid anhydride, which monomers may be copolymerized with less polar \{ monomers such as vinyl chloride, vinyl alcohol or preferably styrene and comprises at least 30% by weight of repeating blocks of formula (1). !\| ■i 4. A pigment composition according to claims 1, 2 or 3, wherein the amount !of crosslinking agent is from 1 to 25% by weight, based on the amount of prepolymer. 1 5. A pigment composition according to claims 1, 2, 3 or 4, comprising pigment particles having a size of from 0.01 to 10 jam, preferably up to 5 f.im, most ;j preferred from 0.05 to 2 /.im, especially from 0.1 to 1 f.tm. 6. A pigment composition according to claims 1, 2, 3, 4 or 5, which comprises li from 0 to 20% by weight of other components, preferably from 0 to 3% by weight of volatile components, most preferred up to 2% by weight of volatile 24 components, based on the total pigment composition. 7. A composition comprising an engineering plastic and a tinctorially effective! amount of at least one pigment composition according to claims 1,2, 3, 4 5 or 6 'I 8. A composition according to claim 7, wherein the engineering plastic is a ; polymer of dielectric constant >2.5 at 20°C, preferably polyester (including PET), polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), I polyamide, polyethylene, polypropylene, styrene/acrylonitrile (SAN) or \|j acrylonitrile/butadiene/styrene (ABS). i i 9. A method of producing a coloured engineering plastic, wherein an engineering plastic and a tinctorially effective amount of at least one pigment composition ■! according to the invention are processed together at a temperature of 200°C or i] above, preferably from 220 to 350°C, most preferred from 240 to 330°C. !j I 10. The preparation of a pigment composition according to claims 1, 2, 3, 4, 5 or li 6, wherein the pigment and the prepolymer are dispersed together, or the \|j pigment is dispersed in a dispersion or solution of the prepolymer, or the j prepolymer is dispersed or dissolved in a dispersion of the pigment, or the the pigment. " \|i li 11. The use of a pigment composition according to claims 1, 2, 3, 4, 5 or 6 for j colouring engineering plastics. ij

Full Text

Heat-stable encapsulated pigments
i The present invention relates to novel pigment compositions, to processes for the
preparation thereof and to the use thereof for producing coloured engineering plastics (thermoplastics that maintain dimensional stability and most mechanical properties above 100°C or below 0°C), especially those based on polyamide.
Mass-colouring of polymer processed at high temperatures, such as engineering
plastics and in particular polyamides is usually carried out using so-called solvent
dyes, which are soluble in the polyamide mass at high processing temperatures
and which, besides having the requisite high heat resistance, also have adequate
chemical stability with respect to, for example, the highly reductive medium of the
polyamide melt. However, soluble dyes generally have much poorer ji
lightfastness, as compared with pigments.
■|i
ji
The use of pigments in such polymers is restricted almost exclusively to inorganic
i| pigments, most of which contain heavy metals, and to a very small selection of
specific organic pigments, mainly from the phthalocyanine or quinacridone class.
Inorganic pigments, however, have generally low chroma and low colour |
strength. Organic pigments have disadvantages such as crystal phase and colour
changes, migration, a frequent tendency of the coloured materials to fluoresce,
and often a reactive interaction with the polymer, leading to degradation of the
pigment and/or deterioration of the polymer's mechanical properties. (j
ii ,i
There is therefore a need for new colourants which in mass-coloured engineering
j! plastics processed at high temperature result in highly saturated, strongly ;i
coloured, non-fluorescent colourations that are light-fast and have high- J
il temperature stability, and which exhibit good allround fastness properties, without
affecting negatively the physical properties of the polymeric material. j
i. FR1 551 400 and EP 0046 729 disclose azopyrimidine colourants. EP 0 061'426 discloses diketopyrrolopyrrole pigments. WO 98/18 866 discloses pteridine| pigments.

US 3,826,670 discloses encapsulated pigments with an intermediate ionically crossiinked polymeric salt and a skin consisting essentially of dense, amorphous, hydrated oxide or hydroxide of silicon, titanium or zirconium.
EP 0 744448 discloses pigments suitable for stencil inks, which are encapsulated in a polymeric matrix obtained from the reaction of polyisocyanates with polyols.
WO 2006/089 933 discloses aqueous dispersions comprising pigments that are at least partially sheathed in radiation-curable polyurethane, their production and use especially for inkjet printing.
US 5,905,111 discloses a continuous process for preparing acrylate based pigment preparations. However, such pigment preparations do not provide satisfactory results in engineering plastics.
US 6,800,127 discloses pigment preparations comprising polyamide particles with an average size of below 50j.im and an average pigment size below 0.2 \xm. However, especially the fastness properties are still not fully satisfactory.
WO 06/111 493 is a patent application according to Art. 54(3) EPC and Rule 64.3 PCT, which is directed to pigments encapsulated by polymers which are not crossiinked.
It has now been found that the pigment compositions according to the invention surprisingly meet the above-mentioned criteria to a larger extent.
The present invention accordingly relates to a pigment composition comprising solid particles, which particles comprise from 20 to 75% by weight of an organic pigment and from 80 to 25% by weight of a crossiinked polymer, preferably from 25 to 60% by weight of an organic pigment and from 75 to 40% by weight of a crossiinked polymer, each based on the total weight of the solid particles, wherein the surface of the solid particles consists essentially of the crossiinked polymer and the crossiinked polymer is obtainable from a crosslinking agent and a prepolymer of average molecular weight Mw from 2000 to 200000, preferably
3

epoxy or primary or secondary amino groups or (b2) unsaturated bonds, wherein Ri is H, CrC4alkyl, C2-C4a!kenyl or COOR5, R2 and R3 are independently from one another H, OR6, NHR6, Ci-C4alkyl or C2-C4alkenyl, R4, R5 and R6 are independently from one another H, unsubstttuted CrC6alkyl or C2-C6aikenyi, or C2-C6alkyl or C2-C6alkenyl each substituted by one or more hydroxy and/or epoxy groups, and n is a number from 2 to 2000, preferably from 5 to 1500.
The organic pigment is either directly embedded in the crosslinked polymer, or it is chemically or physically surface-modified or encapsulated, for example with a pigment derivative, a polymer or a layer of one or more transition metal oxides adsorbed on or bound to its surface. However, the pigment and any optional additional components should be fully surrounded by crosslinked polymer, as the surface of the solid particles should consist essentially of the crosslinked polymer, in order the desired properties to be obtained.
The prepolymers are most suitably homo- or copolymers based on unsaturated monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and their derivatives, such as esters and amides thereof and maleic acid anhydride, which monomers may be copolymerized with less polar monomers such as vinyl chloride, vinyl alcohol or preferably styrene. Preferably, the prepolymers comprise at least 30% by weight of repeating blocks of formula (I).
These prepolymers are crosslinked with any known crosslinking agent, for example reactive crosslinking agents such as polyisocyanates, polyhydrazides, polycarboxylic acids, polyoxazolines, polyaziridines, polyepoxides, polysulfonazides, poiyketimines, melamine-formaldehyde resins, urea-formaldehyde resins, or with crosslinking agents forming salts for example with carboxy groups of the prepolymer, such as polyamines or metal ions. Polyfunc-
4

tional crosslinking agents comprise generally from 2 to 10, preferably 2, 3 or 4, especially 2 functional groups.
A particularly preferred aspect of the invention, however, is the use of self crosslinking prepolymers, which comprise both crosslinkable and crosslinking groups such as described above. The crosslinkable and crosslinking groups may be on the same backbone, optionally as blocks of a copolymer, or also on different backbones imbricated together.
Suitable prepolymers are known and a large choice thereof is available commer¬cially, too. Suitable prepolymers are for example disclosed in WO 01 /74 735. Commercially available self crosslinking prepolymers are for example Acronal® LR 8977, Acronal® S 760 na (both BASF AG, Ludwigshafen/DE) and Glascol® C 44 (CIBA Specialty Chemicals Inc.).
The amount of crosslinking agent is generally from 1 to 25% by weight, based on the amount of prepolymer. When the crosslinking agent is separately added to the prepolymer, its amount is preferably from 2 to 20% by weight, most preferably from 3 to 10% by weight, based on the amount of prepolymer. When the crosslinking agent is physically comprised in a self crosslinking prepolymer, its amount is preferably from 1 to 20% by weight, most preferably from 4 to 10% by weight, based on the amount of prepolymer. When the crosslinking agent is part of a self crosslinking prepolymer backbone, the amount of monomers comprising self crosslinking groups used to make the prepolymer is preferably from 1 to 20% by weight, most preferably from 4 to 10% by weight, based on the total amount of monomers used to make the prepolymer.
Crosslinking reactions are known in the art of coatings (see for example Ullmann's Encyclopedia of Industrial Chemistry, Paints and Coatings, 2. Types of Paints and Coatings (Binders), Wiley-VCH Verlag GmbH & Co. KGaA, 6th Edition 2002). The crosslinking reaction can take place simply at room temperature, such as in the case of aqueous acrylic prepolymer dispersions to which bishydrazides or aziridines are subsequently added, or at elevated temperature, such as from

I
i
50 to 300°C, especially from 130 to 200°C, optionally in the presence of a jj suitable catalyst, for example acids, metal compounds, amines, ammonium'or hydroxy ions, such as hydrochloric acid, dibutyl tin laurate, triethylamine or j-
tetrabutylammonium iodide. |
i
i! ii
The instant pigment compositions generally comprise pigment particles having a
size of from 0.01 to 10 ^m, preferably up to 5 jam, most preferred from 0.05 to
2 ]im, especially from 0.1 to 1 |.im. The capsules comprising the pigment ll
preferably have an average volume from 10"20 to 10~8 m3, especially from 10~18 to
10"10m3. |
i The instant pigment compositions comprise adequately from 0 to 20% by weight
of other components, preferably from 0 to 3% by weight of volatile components,
most preferred up to 2% by weight of volatile components, based on the total
pigment composition. The volatile components preferably consist of organic-!
solvents or water, most preferred water.
Any organic pigment can be used, for example diketopyrrolopyrrole, quinacrido-ne, azo, quinophthalone, phthalocyanine, indanthrone, flavanthrone, pyranthrone, anthraquinone, perylene, dioxazine, perinone, thioindigo, isoindolinone, isoindoline, pteridine and metal complex pigments.
However, preference is given to the use of diketopyrrolopyrrole, azo, pteridine,
isoindoline and isoindolinone pigments, especially 'v

wherein R7 and R8 are each independently of the other a group of formula j

naphthyl which are each unsubstituted or substituted by halogen, OH, NH2l
i Ci-C4alkyl or CrC4alkoxy, preferably NH2, OH, hydrogen, methyl, ethyl,
NHCOR37, NHCOOR37, NHCONHR37, NHCONR36R37 or phenyl which is ;,
unsubstituted or substituted by OH or NH2, most preferred NH2, OH, hydrogen,
methyl, NHCOR37 or phenyl which is unsubstituted or substituted by NH2) wherein
R3e is Ci-C4alkyl; phenyl which is unsubstituted or substituted by halogen, i]
Ci-C4a)kyl or d-C4-alkoxy, COR37, COOR37 or CONHR37; and
j]
R37 is Ci-C4alkyl or phenyl which is unsubstituted or substituted by halogen/1
Ci-C4alkyl or Ci-C4-alkoxy, preferably Ci-C4alkyl or phenyl which is unsubstituted
or substituted by chloro, methyl, ethyl, methoxy or ethoxy, most preferred methyl,
ethyl or phenyl, with the proviso that at least two of the radicals R32, ^33, R34,and
R35 are NH2 or OH, most preferred wherein R32 and R35 are identical, and R33 and
;L R34 are identical and at least one of the pairs R32 and R35 or R33 and R34 is N'H2 or
OH; ||

trimethylcyclohexyl, menthyl, thujyl, bornyl, 1-adamantyl or 2-adamantyl.
C2-Ci2Alkenyl or C3-Ci2cycloalkenyl is respectively C2-C12alkyl or C3-Ci2cycloalkyl that is mono- or poly-unsaturated, wherein two or more double bonds may be isolated or conjugated, for example vinyl, allyl, 2-propen-2-yl, 2-buten-1 -yl, 3-buten-1-yl, 1,3-butadien-2-yl, 2-cyclobuten-1-yl, 2-penten-1-yl, 3-penten-2-yl, 2-methyl-1-buten-3-yl, 2-methy!-3-buten-2-yl, 3-methyl-2-buten-1-yl, 1,4-pentadien-3-yl, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl, 3-cyclohexen-1-yl, 2,4-cyclohexadien-1-yl, 1-p-menthen-8-yl, 4{10)-thujen-10-yl, 2-norbornen-1-yl, 2,5-norbornadien-1 -yl, 7,7-dimethyl-2,4-norcaradien-3-yl or the various isomers of hexenyl, octenyl, nonenyl, deceny! ordodecenyl.
The pigments preferably have a specific surface area of from 10 to 150 rn2/g. Special preference is given to opaque pigments having a specific surface area of from 12 to 50 m2/g and to transparent pigments having a specific surface area of from 50 to 100 m2/g.
The instant pigment compositions are suitably prepared by dispersing the pigment and the prepolymer in an inert liquid medium, such as an organic solvent or preferably water, then crosslinking the prepolymer by addition of a crosslinking agent, addition of a crosslinking catalyst and/or heating. The instant pigment compositions are then preferably isolated by filtration and dried.
Alternatively, it is also possible to isolate and optionally dry the dispersion of pigment in the prepolymer, optionally also comprising a thermally crosslinking agent, and then only to perform crosslinking by heating.
Crosslinking, or optionally the final part of crosslinking, can also be effected upon final processing of the engineering plastic to be coloured.
The pigment and the prepolymer can be dispersed together, or the pigment can be dispersed in a dispersion or solution of the prepolymer, or the prepolymer can be dispersed or dissolved in a dispersion of the pigment, or the prepolymer can be prepared by emulsion or suspension polymerisation in presence of the
14

pigment, for example by adding the pigment to the polymerisable monomer or mixture of monomers before the subsequent polymerisation reaction.
The present invention also relates to a method of producing a coloured engineering plastic, wherein an engineering plastic and a tinctorially effective amount of at least one pigment composition according to the invention are processed together at a temperature of 200°C or above, preferably from 220 to 350°C, most preferred from 240 to 330°C.
Generally, the amount of instant pigment composition will be from 0.001 to 70% by weight, based on the total weight of the engineering plastic and instant pigment composition. Preferred are in the case of coloured items from 0.01 to 10% by weight, and in the case of masterbatches from 30 to 60% by weight, each based on the total weight of the engineering plastic and instant pigment composition. The engineering plastics to be colored with the instant pigment compositions are generally polymers having a molecular weight in the range of from 104to108g/mol.
Colouring the engineering plastics with the pigment composition according to the invention is carried out, for example, by mixing such a pigment composition into the substrates using roll mills or mixing or grinding apparatuses, as a result of which the pigment composition is finely distributed in the engineering plastic. The high engineering plastic comprising the admixed pigment composition is then processed by methods known perse, such as calendering, compression moulding, extrusion, spread-coating, melt-spinning, casting or by injection moulding, whereby the coloured material acquires its final shape. Admixture of the pigment composition can also be effected immediately prior to the actual processing step, for example by continuously feeding a solid, for example pulverulent, pigment composition and, at the same time, a granulated or powdered engineering plastic, and optionally also additional ingredients such as, for example, additives, directly into the intake zone of the processing equipment, where mixing takes place immediately before processing. Crosslinking may also be effected or completed at this stage. Generally, however, it is preferable to mix
15

me pigment composition into the engineering plastic beforehand, since more uni¬formly coloured products can be achieved.
Remarkably, the instant pigment compositions largely retain their structure upon processing, so that the instant crosslinked polymer remains around the pigments, thus preventing a direct contact between the pigment and the engineering plastic. The instant pigment compositions also have an excellent compatibility with engineering plastics.
In order to produce non-rigid mouldings or to reduce their brtttleness, it is possible to incorporate so-called plasticisers into the engineering plastics prior to shaping. There may be used as plasticisers, for example, esters of phosphoric acid, phthalic acid or sebacic acid. In the method according to the invention, the plasticisers may be incorporated into the polymers before or after incorporation of the colorant. It is also possible, in order to achieve different colour shades, to add to the engineering plastics, in addition to the pigment composition according to the invention, further pigments or other colorants in any desired amounts, optionally together with further additional ingredients such as, for example, fillers or siccatives (drying agents).
On the other hand, it is sometimes desirable to increase the rigidity and/or solidity, for example by incorporating glass fibers or other known reinforcing agents.
Preferred engineering plastics suitable for colouring in accordance with the invention are very generally polymers having a dielectric constant >2.5 at 20°C, preferably polyester (e.g. PET), polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), polyamide, polyethylene, polypropylene, styrene/acrylonitrile (SAN) or acrylonitrile/butadiene/styrene (ABS).
Special preference is given to polyester and very special preference is given to polyamide, for example polyamide 6, polyamide 6.6, polyamide 12 and aramid.
The pigment compositions according to the invention are well dispersible in the
16

Examples 4-6: Test plates made of polyamide 6 (Ultramid® B3K, BASF) ■
i!
containing 0.2% of the encapsulated pigments according to examples 1-3 are
i
prepared by injection molding from a pre-concentrate compounded in a twin-
ii screw extruder. The processing temperatures are between 240 and 300QC. So
produced test plates show excellent temperature and light stability, as well as
excellent wash stability, no migration of the colorants and no fluorescence, j
18

Claims:
1. A pigment composition comprising solid particles, which particles comprise from 20 to 75% by weight of an organic pigment and from 80 to 25% by weight of a crosslinked polymer, preferably from 25 to 60% by weight of an organic pig¬ment and from 75 to 40% by weight of a crosslinked polymer, each based on the total weight of the solid particles, wherein the surface of the solid particles ;; consists essentially of the crosslinked polymer and the crosslinked polymer is obtainable from a crosslinking agent and a prepolymer of average molecular

amino groups or (b2) unsaturated bonds, wherein R, is H, C1-C4alkyl, !!
C2-C4alkenyl or COOR5, R2 and R3 are independently from one another H, 0,R6,
NHR6l Ci-C4alkyl or C2-C4alkenyl, R4, R5 and R6 are independently from one
another H, unsubstituted Ci-C6alkyl or C2-C6alkenyl, or C2-C6alkyl or C2-C6alkenyl
each substituted by one or more hydroxy and/or epoxy groups, and n is a number
from 2 to 2000, preferably from 5 to 1500. |!

it R9 and R10 are each independently of the other hydrogen, halogen, Ci-C24alkyl,

imidazolyl, pyrazolyl, triazolyl, piperazinyl, pyrrolyl, oxazolyl, benzoxazolyl, i benzothiazolyl, benzimidazolyl, morpholinyl, piperidinyl or pyrrolidinyl, preferably hydrogen, halogen, cyano, carbamoyl, nitro, trifluoromethyl, phenyl, CrC6all Ci-C6alkoxy, CrC6alkylthio or C,-C6atkylamino; ;
i
i
R11 and R12 are each independently of the other hydrogen, halogen or Ci-C6alkyl;
ij R13 is -CH2-, -CH(CH3)-, -C(CH3)2-, -CH=N-, ~N=N-, -0-, -S-, -SO-, -S02-, NH;|or
-NCi-C6alkyl-;and |
i!
R14 and R15 are each independently of the other hydrogen, halogen, Ci-C6alkyl,
j
li i
wherein R16, R17 and RIB are independently from one another hydrogen; j Ci-C6alkyl, C3-C6cycloalkyl, benzyl or phenyl each unsubstituted or substitute^ by halogen, OH, OR26l COR26, SR26) S02R26, SO3R26, CN, COOH, COO"+Mi, jj . COOR26, CONH2l CONHR26 or CONR26R27, preferably Ri6, R17 or Ri8 are
20

unsubstituted or substituted by OH or NH2, most preferred NH2l OH, hydrogen, methyl, NHCOR37 or phenyl which is unsubstituted or substituted by NH2, wherein
!]
R36 is CrC4alkyl; phenyl which is unsubstituted or substituted by halogen, |
Ci-C4alkyl or CrC4-alkoxy, COR37, COOR37 or CONHR37; and \R37 is CrC4alkyl or phenyl which is unsubstituted or substituted by halogen, ii
CrC4alkyl or CrC4-a!koxy, preferably d-C4alkyt or phenyl which is unsubstituted
or substituted by chloro, methyl, ethyl, methoxy or ethoxy, most preferred methyl,
il ethyl or phenyl, with the proviso that at least two of the radicals R32, R33, R34 and
R35 are NH2 or OH, most preferred wherein R32 and R35 are identical, and R33 and
R34 are identical and at least one of the pairs R32 and R35 or R33 and R34 is NH2-or
OH; j!

3. A pigment composition according to claims 1 or 2, wherein the prepolymer is
selected from the group consisting of homo- or copolymers based on unsaturated
monomers selected from the group consisting of acrylic acid, methacrylic acid,
maleic acid and their derivatives, such as esters and amides thereof and maleic
acid anhydride, which monomers may be copolymerized with less polar \{
monomers such as vinyl chloride, vinyl alcohol or preferably styrene and
comprises at least 30% by weight of repeating blocks of formula (1). !|
■i
4. A pigment composition according to claims 1, 2 or 3, wherein the amount !of
crosslinking agent is from 1 to 25% by weight, based on the amount of
prepolymer.
1
5. A pigment composition according to claims 1, 2, 3 or 4, comprising pigment
particles having a size of from 0.01 to 10 jam, preferably up to 5 f.im, most ;j
preferred from 0.05 to 2 /.im, especially from 0.1 to 1 f.tm. 6. A pigment composition according to claims 1, 2, 3, 4 or 5, which comprises
li from 0 to 20% by weight of other components, preferably from 0 to 3% by weight
of volatile components, most preferred up to 2% by weight of volatile
24

components, based on the total pigment composition.
7. A composition comprising an engineering plastic and a tinctorially effective!
amount of at least one pigment composition according to claims 1,2, 3, 4 5 or 6
'I
8. A composition according to claim 7, wherein the engineering plastic is a ;
polymer of dielectric constant >2.5 at 20°C, preferably polyester (including PET),
polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), I
polyamide, polyethylene, polypropylene, styrene/acrylonitrile (SAN) or |j
acrylonitrile/butadiene/styrene (ABS). i
i
9. A method of producing a coloured engineering plastic, wherein an engineering
plastic and a tinctorially effective amount of at least one pigment composition ■!
according to the invention are processed together at a temperature of 200°C or
i]
above, preferably from 220 to 350°C, most preferred from 240 to 330°C. !j
I
10. The preparation of a pigment composition according to claims 1, 2, 3, 4, 5 or
li
6, wherein the pigment and the prepolymer are dispersed together, or the |j
pigment is dispersed in a dispersion or solution of the prepolymer, or the j
prepolymer is dispersed or dissolved in a dispersion of the pigment, or the the pigment. " |i
li
11. The use of a pigment composition according to claims 1, 2, 3, 4, 5 or 6 for j
colouring engineering plastics.
ij

Documents:

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Patent Number

269650

Indian Patent Application Number

2235/CHENP/2009

PG Journal Number

45/2015

Publication Date

06-Nov-2015

Grant Date

30-Oct-2015

Date of Filing

22-Apr-2009

Name of Patentee

BASF SE

Applicant Address

67056 LUDWIGSHAFEN, GERMANY

Inventors:

#	Inventor's Name	Inventor's Address
1	RUIZ GOMEZ, GLORIA,	2, RUE DU MARECHAL DE LATTRE DE TASSIGNY, F-68300 SAINT-LOUIS
2	RUCH, THOMAS,	RUE DES REGAINS 10, CH-2800 DELEMONT,
3	PRICE, CHRISTINE,	REBENSTRASSE 3, CH-4125 RIEHEN,

PCT International Classification Number

C09B 67/08

PCT International Application Number

PCT/EP07/60944

PCT International Filing date

2007-10-15

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	6122940.7	2006-10-25	EUROPEAN UNION