Title of Invention	NON - AQUEOUS PIGMENT CONCENTRATE
Abstract	Non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: (a) branched hydrocarbons, (b) hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms.

Title of Invention

NON - AQUEOUS PIGMENT CONCENTRATE

Abstract

Non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: (a) branched hydrocarbons, (b) hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms.

Full Text	PIGMENT CONCENTRATE The present invention relates to a non-aqueous pigment concentrate comprising one or more pigments, one or more pigment dispersants, one or more resins, and optionally one or more solvents and/or diluents. In the paint industry, stock control and logistics are often rationalized by using colour mixing systems. These include systems where the paint formulation selected by a user is produced by selecting a base paint from a limited number of available base paints and tinting the selected base paint with the aid of one or more pigment concentrates or tinting pastes. In other systems, pigment concentrates are mixed with resin compositions to form a paint or toner of a colour and in a next step an appropriate selection of these toners is mixed to form a paint of a desired end colour. Pigment concentrates generally distinguish themselves from pigmented coating compositions in that they have higher pigment loads than colour strength requires. Pigment concentrates differ from coating compositions in their generally higher pigment concentration and the limited number of pigment types they contain - usually one, sometimes two. The pigments present in pigment concentrates are colouring pigments, whereas coating compositions generally also contain extender pigments and other functional pigments. Further, although pigment concentrates may be film-forming, the resultant films will not have the performance - as to solvent resistance, for instance - associated with coating compositions. For environmental reasons, it is desirable to reduce the emission of volatile organic compounds and, hence, the solvent content. To balance pigment concentrate viscosity requirements with a minimized volatile organic content (VOC), additional resins typically having a relatively low molecular weight can be used. Such resins can help also to prevent the agglomeration of pigments at the moment when the pigment concentrate is mixed into the base paint and help to compatibilize the pigment concentrate content with the base paint binder system. Non-volatile reactive and/or non-reactive diluents may also be used to reduce the VOC. Pigments of the various colours, pigment dispersants, diluents, and solvents can vary considerably in nature. Hence, it is often necessary to use a compatibilizer resin which is compatible not only with various types of dispersants and solvents but also with various types of base paint binder systems or let-down resins used to make toners. Also, the compatibilizer aids the incorporation of the colorant into the base paint. A pigment concentrate comprising a polyester resin is disclosed for example in WO 02/096997. These polyesters are oxidatively drying alkyds which do not have broad compatibility with other binder systems. WO 03/089522 discloses pigment dispersions comprising carbamate-functional polyester pigment dispersants. The carbamate groups serve as an anchoring group which is affinitive with pigment particles. The volatile organic content is high and substantially above 350 g/l. The object of the present invention is to provide a non-aqueous pigment concentrate comprising a resin which is widely compatible with different binder systems. A further object is to provide a resin which allows the formulation of pigment concentrates having a low volatile organic content (VOC). This object is achieved by a non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: (a) branched hydrocarbons, (b) hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms. The concentrate may further comprise one or more solvents and/or diluents, as long as the pigment concentrate remains non-aqueous, which is defined as containing less than 5 wt% of water, based on the total weight of the pigment concentrate. More preferably, the pigment concentrate contains less than 2.5 wt%, even most preferably less than 1 wt% of water. The oligo-ester building blocks can be formed by reacting one or more anhydrides and/or the corresponding dicarboxylic acids with one or more diols and/or monoepoxides having a pendant hydrophobic group, thereby forming ester linkages. An example of a suitable monoepoxide is glycidyl neodecanoate. Surprisingly, it was found that such polyesters are compatible with a wide range of binder resins and solvent types. The term "oligo-ester building block" is defined as a building block which contains at least one ester group and is linked to other building blocks of the polyester by at least one ester group. The polyester present in the pigment concentrate according to the present invention contains on average at least 1, preferably 2-7, more preferably 2-5, and most preferably 3-5 oligo-ester building blocks. The oligo-ester building block can have a structure according to the following formula: wherein: Q = a covalent bond or a hydrocarbon radical with at least one, preferably 1-4, more preferably 2-4, and most preferably 2 carbon atoms; X = a divalent, optionally branched and/or substituted, radical, e.g., a saturated or unsaturated hydrocarbon radical containing at least 2 carbon atoms, optionally comprising further ester groups; Y = a trivalent hydrocarbon radical; Z = a group linking the hydrophobic tail to the oligo-ester building block, or a covalent bond. Examples of suitable linking groups are ester groups, ether groups, C-C single or double bonds R = the hydrophobic tail. Alternatively, building blocks having a similar structure but without the X group can be used. In another embodiment, oxalic acid can be used to introduce the ester groups. In that case, both Q and X are absent from the building block. As can be seen in the above structure, the oligo-ester building block contains at least one ester group and can be linked to other building blocks by ester groups. Oligo-ester building blocks wherein Q and X are present to form a ring can for example be obtained by esterifying cyclic anhydrides or their corresponding dicarboxylic acids possessing cyclic groups with groups bearing a hydrophobic tail. The anhydride can for example be a cyclic anhydride of unsaturated, aromatic and/or saturated cyclic or acyclic dicarboxylic acids. The anhydride can for example be phthalic anhydride, hexahydrophthalic anhydride, methyl- hexahydrophthalic anhydride, tetrahydrophthalic anhydride, or mixtures thereof. Suitable dicarboxylic acids are, for example, the carboxylic acids of the aforementioned anhydrides or, e.g., 1,3-cyclohexane dicarboxylic acid or 1,4- cyclohexane dicarboxylic acid, or their cyclopentane or cycloheptane counterparts. Acyclic oligo-ester building blocks, wherein X is absent, can be obtained using for instance succinic anhydride, maleic anhydride, malonic anhydride, the corresponding dicarboxylic acids, or oxalic acid. Oligo-ester building blocks wherein X comprises an ester group can for example be obtained using tricarboxylic acids or their anhydrides, such as trimellitic anhydride. Any combination or mixture of the listed acids and/or anhydrides can also be used to obtain oligo-ester building blocks. The carboxylic acids or anhydrides can be linked by esterification with a monoepoxide bearing a hydrophobic tail to form the oligo-ester building block. Suitable monoepoxides are, for example, epoxidized olefins, such as cyclohexene oxide or epoxidized a-olefins, e.g., dodecene oxide, tetradecene oxide, and octadecene oxide; glycidyl ethers, such as ethylhexyl glycidyl ether, n-butyl glycidyl ether, t-butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether; and the glycidyl esters of carboxylic acids, such as versatic acid glycidyl ester, e.g., glycidyl neodecanoate, commercially available from Hexion as Cardura® E10P or mixtures thereof. Other suitable examples are epoxy- containing aromatic hydrocarbons such as styrene oxide. Instead of or in addition to monoepoxides, diols can be reacted with the carboxylic acids or anhydrides to form the oligo-ester building block. Suitable diols include 1,3-propane diol, 1,2-ethane diol, 1,4-butane diol, 1,5-pentane diol, 1,6-hexane diol, diethylene glycol, triethylene glycol, polyethylene glycols, dipropylene glycol, and polytetrahydrofuran. Suitable branched diols include dimethylol propane, neopentyl glycol, 2-propyl-2-methyl-1,3-propane diol, 2- butyl-2-ethyl-1,3-propane diol, 2,2-diethyl-1,3-propane diol, 1,2-propane diol, 1,3-butane diol, 2,2,4-trimethylpentane-1,3-diol, trimethylhexane-1,6-diol, 2- methyl-1,3-propane diol, tripropylene glycol, and polyoxypropylene glycols. Suitable cycloaliphatic diols include 1,4-cyclohexane diol, cyclohexane dimethanol and cyclic formals of pentaerythritol, and 1,3-dioxane-5,5- dimethanol. Suitable aralkyl diols include 1,4-xylylene glycol and 1-phenyl-1,2- ethane diol. If it is desired to obtain a branched polyester, polyols and/or polyacids may be used. Polyols include polyfunctional phenols, triols, and tetrols. Suitable triols include glycerol, trimethylol propane, trimethylol ethane, trimethylol butane, 3,5,5- trimethyl-2,2-dihydroxyrnethylhexan-1-ol, and 1,2,6-hexane triol. Alternatively, cycloaliphatic and aralkyl triols and/or corresponding adducts with alkylene oxides or derivatives thereof can be used. Suitable tetrols include erythritol, pentaerythritol, ditrimethylol propane, diglycerol, and ditrimethylol ethane. It is also possible to use cycloaliphatic and/or aralkyl tetrols as well as corresponding adducts with alkylene oxides or derivatives thereof. Polyols with even more hydroxyl groups, such as dipentaerythritol, dulcitol, and threitol, can also be used. Such polyols are particularly useful as starter molecules to obtain branched star-shaped molecules. Suitable polyacids include 1,2,4-butane tricarboxylic acid and trimellitic acid. Acid alcohols, such as tartaric acid and 2,2-bis(hydroxymethyl) propanoic acid, can be used additionally or alternatively. A polyester prepared with pentaerythritol as a starter molecule can have the following structure: wherein R is the hydrophobic tail. Optionally, the polyesters may contain a repetition of oligo-ester building blocks formed from the alternating reaction of a cyclic anhydride or diacid with a (mono)epoxide or diol. This can for example be initiated by a monofunctional, difunctional or polyfunctional starter molecule and can be catalyzed, for instance by catalysts such as zinc salts, e.g., zinc acetate. Monoalcohols can for instance be used as a starter molecule. Suitable mono- functional alcohols for use as starter molecules include linear alcohols, such as methanol, ethanol, hexanol, butanol, octanol, hexadecanol, etc., branched alcohols, such as iso-propanol, 2-ethylhexanol, etc., cycloaliphatic alcohols, such as cyclohexanol, aralkyl alcohols, such as benzyl alcohol, or phenol. For example, a polyester prepared with 2-ethylhexanol, hexahydrophthalic anhydride, and a glycidyl ester can have the following structure: wherein R is the hydrophobic tail, e.g. a hydrocarbon group, and n > 0, preferably 0-6, more preferably 1-5, and most preferably 2-4. Another example is a similar polyester with groups derived from glycidyl ethers. Other possible starter molecules are amines. Suitable primary amines include monoamines, e.g. alkyl amines such as butyl amine, and diamines, e.g., alkylene diamines such as ethylene diamine. Secondary monoamines, such as piperidine, dialkyl amine, e.g. dibutyl amine, or diamines, such as piperazine, can also be used. Suitable carboxylic acid-functional starter molecules include monoacids, such as 2-ethylbutyric acid, or cyclohexane carboxylic acid, diacids, such as adipic acid or 1,4-cyclohexane dicarboxylic acid, and polyacids, such as 1,2,4-butane tricarboxylic acid. Monothiols, such as dodecane thiol, dithiols, or polythiols, such as pentaerythritol tetrakis (3-mercaptopropionate), can also be used as starter molecules. Further, blends of two or more of the aforementioned starter molecules can be used. Alternatively or additionally, starter molecules of mixed functionality can be used, such as acid alcohols, amine alcohols, aminoacids, aminothiols, acid thiols, thiol alcohols or starters having more than two different functionalities. Suitable acid alcohols include tartaric acid and 2,2-bis- (hydroxymethyl) propanoic acid. Suitable amine alcohols include diethanolamine and 1-(2-hydroxyethyl) piperazine. A suitable example of an acid thiol is 3-mercaptopropanoic acid. A suitable example of a thiol alcohol is 2-thioethanol. Polymeric starters, such as acrylic polyols and acrylic acid alcohols, may also be used. If desired, the hydroxy-functional starter molecules may be generated in situ, for instance via the reaction of an epoxide with a monocarboxylic acid. A suitable epoxide is for example glycidyl neodecanoate. Other means of generating the hydroxyl group in situ include the reaction of an epoxide with an amine, thiol or phenol or the reaction of a cyclic lactone, e.g., £-caprolactone, with an amine, an alcohol or a thiol. If a monofunctional starter molecule is used, the resulting polyester will contain a tail originating from said starter molecule on one end of the polymer chain. The present invention therefore also relates to a polyester consisting of (i) at least one, preferably 1-7, more preferably 2-6, and most preferably 3-5 oligo- ester building blocks with the hydrophobic tail linked thereto, and (ii) a tail originating from a monofunctional starter molecule on one end of the polymer chain, said monofunctional starter molecule being selected from the group consisting of alcohols, amines, carboxylic acids, and thiols. Preferably, the hydrophobic tail is linked to the oligo-ester building block by an ester group. The monofunctional starter molecule preferably is a branched mono-alcohol, such as 2-alkyl alkanol, e.g. 2-ethylhexanol. So, when the monofunctional starter molecule is 2-ethylhexanol, the resulting polymer chain will contain a 2-ethylhexyl tail on one end. The polyester used in the present invention possesses hydrophobic tails. The term hydrophobic describes the tendency of a molecule or molecular group to pass out of or not penetrate into water, as defined in ISO 862: 1995. Hydro- phobic properties of molecules or groups are generally linked to the presence of hydrocarbon groups. The hydrophobic tails preferably comprise 4-20, more preferably 6-16, even more preferably 8-10, and most preferably about 9 carbon atoms. The hydrocarbon tails can be saturated, unsaturated, or aromatic hydrocarbon groups and they may be branched, linear, or cyclic. The hydrophobic tails can for example also contain ether and/or ester groups, such as groups obtainable by the ring opening of e-caprolactone by an acid or an alcohol. However, it is essential that when the hydrophobic tail is a linear hydrocarbon linked to the oligo-ester building block via an ester group (i.e. when Z is an ester group), the linear hydrocarbon contains 3 to 12 carbon atoms. Preferably, the polyester has an acid value below 20 mg KOH/g, more preferably below 10 mg KOH/g, most preferably below 5 mg KOH/g. To reduce the acid value of the end product, an acid-reactive compound, such as a monoalcohol or monoepoxide, can be used for reaction with the terminal carboxylic acid groups of the polyester. Suitable compounds include the monoepoxides and monoalcohols listed above. Optionally, the polyester resin may have hydroxyl-functional groups. In that case, they can be reacted in paint systems based on crosslinking with OH- reactive crosslinkers, such as isocyanates. The polyester preferably has a hydroxyl value of 0-250 mg KOH/g, more preferably 0-160 mg KOH/g. The hydroxyl value can be lowered, for example by reaction with OH-reactive compounds, such as acetic anhydride. Whereas in WO 03/089522 polyesters with carbamate pigment anchoring groups are used as dispersants, the polyesters of the present invention are used as compatibilizer resins and combined with dispersants in the pigment concentrate. These dispersants typically comprise a polymeric part and one or more pigment-affinitive groups. Often, these dispersants are built as comb polymers having one or more polymer chains and one or more pigment-affinitive groups. Generally, a dispersant with a single polymer chain has a pigment- affinitive group at a terminal position. Other types of dispersants can have a backbone with pigment-affinitive groups and have polymeric tails which are soluble in the solvent to be used. In order to be soluble in organic solvents, the polymeric tails can for example consist mainly of aliphatic hydrocarbon parts. Generally, the pigment-affinitive groups are groups with high polarity, e.g. ionic groups, such as carboxylic, sulphate, sulphonate, amine salts, phosphate or phosphonate groups. Non-ionic groups, such as carbamate, urea, amide or amine groups, can also be suitable pigment-affinitive groups. Suitable dispersants are for instance the Solsperse®, Solplus® and Ircosperse® dispersants, available from Lubrizol Advanced Materials, the Disperbyk® dispersants from Byk Chemie, the Efka® dispersants from Ciba, the Tego® dispersants from Degussa, and the Nuosperse® dispersants from Elementis Specialies. The amount of dispersant can for example be at least about 0.1% by weight of the pigments used, e.g., at least about 2% by pigment weight. The amount of dispersant can for example be below 100% by weight of the pigments used, e.g., below about 10% by pigment weight. The pigment concentrate can contain solvents but may also be solvent-free if so desired. Suitable solvents include for example aromatic solvents, such as xylene, mesitylene, or the solvents marketed as Solvesso® 100 of Exxon. Aromatic-free solvents, such as aliphatic hydrocarbon solvents, e.g. isoparaffins; esters, such as n-butyl acetate; ethers, such as butoxy ethanol; ether esters, such as methoxy propyl acetate, or ketones, and alcohols, such as n-butanol, can also be used, as can white spirit. Alternatively or additionally, the composition may contain non-volatile reactive diluents, such as hexane diol diglycidyl ether, glycidyl neodecanoate, epoxidized linseed oil or benzyl alcohol, and/or non-reactive diluents, such as for instance dibutyl phthalate and liquid aromatic hydrocarbon resins, such as the hydrocarbons of the commercially available Hirenol® PL and CL series ex Kolon Chemical Company. Mixtures of any combination of two or more of the aforementioned solvents and/or diluents can also be used. The pigments to be used can be inorganic or organic pigments. Examples of inorganic pigments include titanium dioxide, zinc oxide, carbon black, iron oxides, bismuth vanadates, raw and burnt sienna or umber, chromium oxide green, cadmium pigments, and chromium pigments. Examples of organic pigments include phthalocyanines, quinacridones, anthraquinones, isoindolines, pyranthrones, indanthrones, derivatives of dioxazine, diketopyrrolopyrroles, and azo-compounds. The pigment concentrates of the present invention can also comprise effect pigments or luster pigments. These are platelet-shaped mono- or multi-layer pigments showing visual effects marked by the interplay of interference, reflection, and absorption phenomena. Examples are aluminium platelets and aluminium, iron oxide, and pearlescent or mica platelets bearing one or more coats, especially of metal oxides. Dichroic or colour shift pigments can also be used. Optionally, filler pigments may be added, such as clay, barytes, silica, talc, mica, wollastonite, and the like. High pigment contents can be realized in the pigment concentrates according to the present invention without the need to increase the solvent content, while maintaining a satisfactory viscosity. If organic pigments are used, the pigment content suitably ranges from 5-45% by weight, preferably from 25-40% by weight, based on the total weight of the pigment concentrate. If inorganic pigments are used, the pigment content may be more than 30% by weight, e.g., 40-60% by weight, or even higher, for instance in the case of titanium dioxide. If translucent pigments, e.g. translucent iron oxides, are used, the pigment content can be over 5% by weight, preferably over 20% by weight or even over 30% by weight. If carbon black is used, the pigment content may for instance be 10-20% by weight. Preferably, the pigment concentrate has a volatile organic content VOC not exceeding 250 g/l, measured according to EPA method 24 of the US Environmental Protection Agency. Preferably, the VOC of the pigment concentrate is low enough to allow formulation of paints with a VOC not exceeding 100 g/l. Optionally, the pigment concentrate comprises an additional resin, such as an acrylate resin or a urea-aldehyde resin. Suitable acrylic resins are for instance Setalux® 1385-51 available from Nuplex Resins. The mixing ratio between the additional resin and the polyester is preferably 0:1 - 4:1, more preferably 1:1 - 3:1. The pigment concentrate according to the present invention can for example be prepared by grinding a pigment with a dispersant. The polyester is added during or after grinding. Optionally, further resins, such as an acrylic resin, may be added during or after grinding. The pigment concentrate according to the present invention is suitable to tint various types of base paints. The base paints can be based on inorganic binders, such as polysiloxanes, or organic binders, such as acrylates, polyesters, alkyds or polyurethanes, or mixtures or hybrids thereof. Solvent borne base paints can for example be based on aliphatic or aromatic solvents. The pigment concentrate according to the invention can also be used in toner systems as described above. The invention is further illustrated by the following examples. EXAMPLES Materials In these examples the compositions listed below are available as indicated. Bayferrox® Yellow 3920 yellow iron oxide pigment, of Bayer; Cardura® E10P glycidyl neodecanoate, available from Hexion; Dowanol® PM Acetate 1-methoxy-2-propyl acetate, available from Dow; Disperbyk® 170 dispersant, available from Byk Chemie; Fascat®4101 butyl chlorotin dihydroxide catalyst, available from Arkema; Intermediate® 3074 polysiloxane, available from Dow Corning; Irgazin® Red 2030 red pigment, available from Ciba Specialty Chemicals; Laropal® A81 urea aldehyde resin, available from BASF; Monastral® Blue CSN blue copper (II) phthalocyanine pigment, available from Heubach; Setal®164, polyester polyol resin, available from Nuplex Resins; Setalux® 1161 acrylate, available from Nuplex Resins; Setalux® 1385-51 acrylic polyol, available from Nuplex Resins; Solsperse® 38500 pigment synergist, available from Lubrizol Advanced Materials; Solsperse® 5000 dispersant, available from Lubrizol Advanced Materials; Special Black 100 carbon black, available from Degussa; Sunfast® Blue 15.2 blue pigment, available from Sun Chemical; Synocure® 892 BA70 acrylic polyamine, available from Cray Valley; Tioxide®TR92 titanium dioxide pigment, available from Huntsman; Trigonox®21 tert-butyl peroxy-2-ethyl hexanoate, available from Akzo Nobel Chemicals. In the Examples, all amounts are in grams, unless indicated otherwise. Example 1 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 104.3 g of neopentyl glycol were mixed with 308.7g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at 150°C for 1 hour. Then 52.1 g of neopentyl glycol were added together with 0.23 g of Fascat® 4101. The mixture was heated to 200°C and kept at 200°C for approximately 6 hours, after which it was cooled to 150°C and 0.38 g triphenyl phosphine was added. Then 212.2 g of Cardura® E10P were added over 3 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P the mixture was kept at the same temperature until an acid value Example 2 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 90.7 g of neopentyl glycol were mixed with 268.4 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at 150°C for 1 hour. Then 62.8 g of cyclohexane dimethanol were added together with 0.21 g of Fascat® 4101. The mixture was heated to 200°C and kept at 200°C for approximately 4 hours, after which it was cooled to 150°C and 0.4 g triphenyl phosphine was added. Then 209.6 g of Cardura® E10P were added over 2 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P the mixture was kept at the same temperature until an acid value Example 3 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 71.6 g of 2-butyl-2- ethyl-1,3-propanediol were mixed with 192.5 g cyclohexane-1,2-dicarboxylic acid and 0.13 g of Fascat® 4101. The mixture was heated to 200°C and kept at this temperature for 1 hour, after which it was cooled to 150°C and 0.55 g of triphenyl phosphine was added. Then 301.5g of Cardura® E10P were added over 2 hours whilst maintaining the reaction at 150°C. The mixture was kept at the same temperature for a further 2 hours until an acid value was obtained. Example 4 In a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 31.6 g of 2-butyl-2-ethyl-1,3-propanediol were mixed with 79.4 g of hexahydrophthalic anhydride. The mixture was heated to 140°C and kept at this temperature for 1 hour, after which 0.25 g of triphenyl phosphine was added. Then 142.2 g of Cardura® E10P were added over 2 hours whilst maintaining the reaction at 140°C. Then the mixture was kept at the same temperature until an acid value Example 5 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 53.4 g of 2-ethylhexanol were mixed with 252.6 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.7 g of triphenyl phosphine was added. 393.3 g of Cardura® E10P were then added over 4 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value KOH/g was obtained. Example 6 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 50.0 g of 2-ethylhexanol were mixed with 236.8 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.57 g of triphenyl phosphine was added. Then 286.1 g of 2-ethylhexyl glycidyl ether were added over 4 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value Example 7 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 69.9 g of pentaerythritol were mixed with 316.6 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.91 g of triphenyl phosphine was added. Then 513.5 g of Cardura® E10P were added over 2.5 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value Example 8 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 72.5 g of pentaerythritol were mixed with 328.4 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.98 g of triphenyl phosphine was added. 533.3 g of 2-ethylhexyl glycidyl ether were added over 4 hours whilst maintaining the reaction at 150°C. Subsequently, the mixture was kept at the same temperature until an acid value Example 9 An amount of 87.8 g of hexahydrophthalic anhydride was charged into a 0.5- litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle. The charge was heated to 50°C and 18.4 g of dibutyl amine were added over 30 minutes. The mixture was heated to 150°C and kept at 150°C for 1 hour, after which 0.25 g of triphenyl phosphine was added. 136.7 g of Cardura® E10P were then added to the mixture over 4 hours whilst maintaining the reaction at 150°C. Subsequently, the mixture was kept at the same temperature until an acid value Example 10 An amount of 20.8 g of dibutyl amine was charged into a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle. The reactor flask was heated to 80°C and 38.6 g of Cardura® E10P were added over 1 hour whilst maintaining the temperature at 80°C. The mixture was then heated to 125°C for 4 hours. The reaction was cooled to 60°C and 74.4 g of hexahydrophthalic anhydride were added. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.25 g of triphenyl phosphine was added. Subsequently 115.9 g of Cardura® E10P were added over 2.5 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until the acid value was below 5 mg KOH/g. Example 11 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 73.3 g of 2-butyl-2- ethyl-1,3-propanediol were mixed with 98.5 g of cyclohexane-1,2-dicarboxylic acid, 98.5 g of cyclohexane-1,4-dicarboxylic acid, and 0.14 g of Fascat® 4101. The mixture was heated to 200°C and kept at this temperature for 1 hour, after which it was cooled to 150°C and 0.54 g of triphenyl phosphine was added. Then 286.6 g of Cardura® E10P were added over 2 hours whilst maintaining the reaction at 150°C. The mixture was kept at the same temperature until an acid value Example 12 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 41.7 g of 2,2- bis(hydroxymethyl) propanoic acid were mixed with 239.0 g of hexahydro- phthalic anhydride and 0.7 g of triphenyl phosphine. The mixture was heated to 150°C and kept at 150°C for a further hour. Then 425.5 g of Cardura® E10P were added over 3 hours whilst maintaining the reaction at 150°C. The mixture was kept at the same temperature until an acid value obtained. Example 13 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 129.4 g of hexahydro- phthalic anhydride were mixed with 302.4 g of Cardura® E10P and 0.43 g of zinc acetate. The mixture was heated to 90°C and kept at this temperature for 4 hours. The acid value of the product was Example 14 Into a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 227.6 g of the polyester prepared according to Example 7 were charged and heated to 100°C. Then 54.3g of acetic anhydride were added and the mixture was kept at 120°C for 2 hours. The mixture was then heated to 150°C and acetic acid collected in the Dean-Stark trap. The mixture was heated at the same temperature until an acid value Example 15 In a 500 ml reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 45.1 g of 2-ethylhexanol were mixed with 80.1 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.25 g of triphenyl phosphine was added. 124.6 g of Cardura® E10P were then added over 3 hours whilst maintaining the reaction at 150°C. After the addition of Cardura® E10P, the mixture was kept at the same temperature until an acid value KOH/g was obtained. Example 16 In a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 37.6 g of trimethylol propane, 21.6 g of hexahydrophthalic anhydride, and 0.03 g of Fascat® 4101 were mixed and heated to 200°C and kept at 200°C for 4 hours. The mixture was then cooled to 120°C and 86.3 g of hexahydrophthalic anhydride were added and the whole was kept at 120°C for a further 2 hours. The mixture was then heated to 150°C and 0.27 g of triphenyl phosphine was added. 134.3 g of Cardura® E10P were then added over 3 hours whilst maintaining the temperature at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value Example 17 Into a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 177.0 g of 1-methoxy- 2-propyl acetate (Dowanol® PM Acetate) were charged and heated to 150X. Then 93.9 g of hydroxypropyl methacrylate, 90.0 g of butyl methacrylate, 60.0 g of methyl methacrylate, 8.8 g of 1-octanethiol, and 6.5 g of tert-butyl peroxy-2- ethylhexanoate (Trigonox® 21, available from Akzo Nobel Chemicals) were added to a 1-litre conical flask. This mixture was added to the reactor over 3 hours, whilst maintaining the temperature of the reaction at 150°C. The mixture was kept at 150°C for a further hour and 5.0 g of Trigonox® 21 were then added. The reaction was kept at 150°C for another hour. The mixture was then cooled to 80°C and 100.5 g of hexahydrophthalic anhydride were added. The temperature of the mixture was then increased to 150°C and kept there for 2 hours, after which 0.51 g of triphenyl phosphine was added. Then 162.9 g of Cardura® E10P were added over 2 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value Example 18 In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a heating mantle, 69.9 g of pentaerythritol were mixed with 205.5 g of succinic anhydride. The mixture was heated to 150°C and kept at the same temperature for 1 hour, after which 0.91 g of triphenyl phosphine was added. Then 513.5 g of Cardura® E10P were added over 2.5 hours whilst maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the mixture was kept at the same temperature until an acid value was obtained. Compatibility evaluation of the resins of Examples 1 -15 To test the compatibility of the compatibilizer resins of Examples 1-15 with a range of base paint binder systems, the following evaluation procedure was carried out. The evaluation was carried out with the following base resins: an acrylic polyol, an oxidatively drying alkyd based on tall oil fatty acid and pentaerythritol with an oil length of 64%, an acrylic polyamine, Synocure® 892 BA70 available from Cray Valley, and a polysiloxane (Dow Corning® 3074 Intermediate). The base resins and the compatibilizer resins were mixed in a mixing ratio of 10:1. Approximately 0.25 g of the compatibilizer resin was weighed accurately into four glass vials. Into each vial approximately 2.5 g of the required base resin were then weighed accurately. Then into each vial approximately 2.75g of the solvent (1 -methoxy-2-propyl acetate) were weighed accurately. The samples were mixed until completely dissolved. In the case of the vial containing Dow Corning® 3074 Intermediate, 0.125 g of 3-aminopropyl triethoxysilane and 0.05 g of dibutyl tin dilaurate were added. Then films were applied for all samples using a 400 urn film applicator bar on a glass panel and stored at 25°C for 24 hours. The tests were repeated with a storage temperature of 10°C. The compatibility was evaluated visually and categorized as either OK (clear film), slightly cloudy or cloudy. In all cases, the films remained clear and no cloudiness was observed, indicating that the compatibilizer resins are fully compatible with the various binder resins. Compatibility evaluation of the resin of Example 18 The compatibility of the compatibilizer resin of Example 18 was tested with the following resins: acrylic resins Setalux® 1385 and Setalux® 1161 available from Nuplex Resins, Setal® 164, a polyester polyol resin available from Nuplex Resins, and a blend of two cellulose acetate butyrate resins available from Eastman Chemical Company. Each resin, or resin blend in the case of the cellulose acetate butyrates, was mixed with the compatibilizer resin in a 100 ml glass bottle using a mixing ratio of 10:1. To 1 g of compatibilizer resin were added 10 g of the resin being tested. Then to each bottle 11 grams of 1-methoxy-2-propyl acetate solvent were added. The bottles were shaken vigorously until the resin sample had dissolved. The samples were initially judged in the bottle for any indication of incompatibility such as phase separation or haziness. After storage at 25°C for 24 hours all the samples appeared homogenous and clear. The samples were then applied as a wet film using a 200-micron applicator bar on acetate sheets and stored at 25°C for 24 hours. The drawdowns were evaluated visually and categorized as either OK (clear film), slightly cloudy or cloudy. In all cases the resin films remained clear and no cloudiness was observed, which demonstrates that the compatibilizer resin is fully compatible with the tested resins. Viscosity A pigment concentrate was formulated comprising 25 wt.% of a blue pigment, Sunfast® Blue 15.2, 15 wt.% of a 30% solution of the polyester prepared in Example 7, 26 wt.% of a thermosetting acrylic resin, Setalux® 1385 BX51, 24 wt.% of a dispersant, Disperbyk® 170, and 10 wt.% of butyl acetate solvent. The solid content was about 50 wt.%. The pigment to binder ratio was about 1. Zirconia beads (200 g) of diameter 1.25 - 1.6 mm were added to a glass bottle of volume 370 ml. Next, 125 g of the pigment paste premix were added to the bottle. A further 190 g of the zirconia beads were added. A screwtop lid was fitted and the bottle placed in a shaker. The bottle was shaken for 90 minutes in order to achieve a pigment paste Hegman grind of The paste viscosity was measured using a CAP2000 cone and plate viscometer at a shear rate of 75 rpm and 750 rpm, respectively. At a shear rate of 75 rpm, the paste had a viscosity of 2.0 - 2.5 cPs, while the 750 rpm viscosity was 1.5 - 1.8 cPs. This means that although the pigment content was more than 30% higher than that of the prior art pastes, the viscosity was still lower. Determination of achievable VOC Pigment concentrates were prepared using the compatibilizer resins of Examples 1, 2, 3, 5, 7, and 14. A comparative test was carried out using Laropal® A81, available from BASF. In the pigment concentrates Solsperse® 38500, available from Noveon Performance Coatings, was used as a dispersant. The evaluation was carried out with the following pigments- a titamum dioxide (Tioxide® TR92, available from Huntsman), yellow iron oxide (Bayferrox® Yellow 3920 of Bayer), carbon black (Special Black 100, available from Degussa), a blue copper (II) phthalocyanine pigment (Monastral® Blue CSN, available from Heubach), and a red pigment (Irgazin® Red 2030, available from Ciba Specialty Chemicals). The pigment concentrates were prepared by dissolving the compatibilizer resins in 1-methoxy-2-propyl acetate. The compatibilizer resin solution was then mixed with further solvent and the dispersant, Solsperse® 38500. Pigment was added under agitation at a temperature of 40°C. Glass beads of 1 mm diameter were added in a 1:1 weight ratio with respect to the total colorant weight. For the Bayferrox® Yellow 3920 colorant, a 1:1.4 weight ratio was used. The mixture was then mixed with a speed of 8,000 - 10,000 rpm and filtered using a 250 urn polyester mesh for separation from the grinding media. In all cases the product was a fluid, pourable pigment concentrate. Table 1 shows that a VOC of 250 g/l or less can be achieved. Table 2 shows the formulations of the pigment concentrates. CLAIMS 1. Non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: - branched hydrocarbons, - hydrocarbons containing a cyclic group, and - linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms. 2. Pigment concentrate according to claim 1, wherein at least part of said oligo-ester building blocks is obtainable from a cyclic carboxylic anhydride or an ester-forming derivative thereof. 3. Pigment concentrate according to claim 2, wherein the cyclic carboxylic anhydride is hexahydrophthalic anhydride. 4. Pigment concentrate according to any one of claims 1-3, wherein at least part of the oligo-ester building blocks is obtainable by reacting a dicarboxylic acid or a carboxylic anhydride with a monoepoxide. 5. Pigment concentrate according to claim 4, wherein the monoepoxide is a glycidyl ester of an aliphatic acid. 6. Pigment concentrate according to claim 4, wherein the monoepoxide is a glycidyl ether. 7. Pigment concentrate according to any one of the preceding claims, wherein the resin comprises at least one group originating from a mono-, di- or polyfunctional compound selected from the group of alcohols, amines, carboxylic acids, or thiols. 8. Pigment concentrate according to claim 7, wherein said compound is selected from the group consisting of 2-ethylhexanol, neopentyl glycol, trimethylol propane, trimethylol ethane, trimethylol butane, 3,5,5- trimethyl-2,2-dihydroxymethylhexane-1-ol, glycerol, 1,2,6-hexane triol, erythritol, pentaerythritol, dipentaerythritol, ditrimethylol propane, diglycerol, and ditrimethylol ethane. 9. Pigment concentrate according to claim 7, wherein the resin comprises on one end of the polymer chain a tail originating from a monofunctional compound selected from the group of alcohols, amines, carboxylic acids, or thiols. 10. Pigment concentrate according to any one of the preceding claims, wherein the concentrate has a volatile organic content VOC not exceeding 250 g/l. 11. Pigment concentrate according to any one of the preceding claims, further comprising an additional resin. 12. Pigment concentrate according to claim 11, wherein the additional resin is an acylate resin. 13. Process to prepare a polyester with hydrophobic tails by reacting one or more monoepoxides with one or more dicarboxylic acids or anhydrides and a monofunctional starter molecule selected from the group of alcohols, amines, carboxylic acids, or thiols. 14. Process according to claim 13, wherein the starter molecule is a branched mono-alcohol, such as a 2-alkyl alkanol, e.g., 2-ethylhexanol. 15. Process according to claim 13 or 14, wherein at least part of the starter molecule is formed in situ. 16. Polyester consisting of (i) at least one oligo-ester building block with a hydrophobic tail linked thereto and (ii) a tail originating from a monofunctional compound on one end of the polymer chain, said mono- functional compound being selected from the group consisting of alcohols, amines, carboxylic acids, and thiols. 17. Polyester according to claim 16, wherein the monofunctional compound is 2-ethylhexanol. 18. Coating composition comprising the polyester of claim 15 or 16. 19. Use of the pigment concentrate of any one of claims 1-12 in a coating composition. 20. Method for preparing the pigment concentrate of any one of claims 1-12 by grinding the one or more pigments with the one or more dispersants and adding the resin during or after grinding. Non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: (a) branched hydrocarbons, (b) hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms.

Full Text

PIGMENT CONCENTRATE
The present invention relates to a non-aqueous pigment concentrate comprising
one or more pigments, one or more pigment dispersants, one or more resins,
and optionally one or more solvents and/or diluents. In the paint industry, stock
control and logistics are often rationalized by using colour mixing systems.
These include systems where the paint formulation selected by a user is
produced by selecting a base paint from a limited number of available base
paints and tinting the selected base paint with the aid of one or more pigment
concentrates or tinting pastes. In other systems, pigment concentrates are
mixed with resin compositions to form a paint or toner of a colour and in a next
step an appropriate selection of these toners is mixed to form a paint of a
desired end colour. Pigment concentrates generally distinguish themselves from
pigmented coating compositions in that they have higher pigment loads than
colour strength requires.
Pigment concentrates differ from coating compositions in their generally higher
pigment concentration and the limited number of pigment types they contain -
usually one, sometimes two. The pigments present in pigment concentrates are
colouring pigments, whereas coating compositions generally also contain
extender pigments and other functional pigments. Further, although pigment
concentrates may be film-forming, the resultant films will not have the
performance - as to solvent resistance, for instance - associated with coating
compositions.
For environmental reasons, it is desirable to reduce the emission of volatile
organic compounds and, hence, the solvent content. To balance pigment
concentrate viscosity requirements with a minimized volatile organic content
(VOC), additional resins typically having a relatively low molecular weight can
be used. Such resins can help also to prevent the agglomeration of pigments at

the moment when the pigment concentrate is mixed into the base paint and
help to compatibilize the pigment concentrate content with the base paint binder
system. Non-volatile reactive and/or non-reactive diluents may also be used to
reduce the VOC.
Pigments of the various colours, pigment dispersants, diluents, and solvents
can vary considerably in nature. Hence, it is often necessary to use a
compatibilizer resin which is compatible not only with various types of
dispersants and solvents but also with various types of base paint binder
systems or let-down resins used to make toners. Also, the compatibilizer aids
the incorporation of the colorant into the base paint.
A pigment concentrate comprising a polyester resin is disclosed for example in
WO 02/096997. These polyesters are oxidatively drying alkyds which do not
have broad compatibility with other binder systems.
WO 03/089522 discloses pigment dispersions comprising carbamate-functional
polyester pigment dispersants. The carbamate groups serve as an anchoring
group which is affinitive with pigment particles. The volatile organic content is
high and substantially above 350 g/l.
The object of the present invention is to provide a non-aqueous pigment
concentrate comprising a resin which is widely compatible with different binder
systems. A further object is to provide a resin which allows the formulation of
pigment concentrates having a low volatile organic content (VOC).
This object is achieved by a non-aqueous pigment concentrate comprising one
or more pigments, one or more dispersants, and at least one resin,
characterized in that the resin is a polyester comprising at least one oligo-ester
building block with a hydrophobic tail linked thereto, wherein the hydrophobic
tail is selected from the group consisting of: (a) branched hydrocarbons, (b)

hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided
that when said linear hydrocarbon is linked to the oligo-ester building block via
an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms.
The concentrate may further comprise one or more solvents and/or diluents, as
long as the pigment concentrate remains non-aqueous, which is defined as
containing less than 5 wt% of water, based on the total weight of the pigment
concentrate. More preferably, the pigment concentrate contains less than 2.5
wt%, even most preferably less than 1 wt% of water.
The oligo-ester building blocks can be formed by reacting one or more
anhydrides and/or the corresponding dicarboxylic acids with one or more diols
and/or monoepoxides having a pendant hydrophobic group, thereby forming
ester linkages. An example of a suitable monoepoxide is glycidyl neodecanoate.
Surprisingly, it was found that such polyesters are compatible with a wide range
of binder resins and solvent types.
The term "oligo-ester building block" is defined as a building block which
contains at least one ester group and is linked to other building blocks of the
polyester by at least one ester group.
The polyester present in the pigment concentrate according to the present
invention contains on average at least 1, preferably 2-7, more preferably 2-5,
and most preferably 3-5 oligo-ester building blocks.
The oligo-ester building block can have a structure according to the following
formula:

wherein: Q = a covalent bond or a hydrocarbon radical with at least
one, preferably 1-4, more preferably 2-4, and most
preferably 2 carbon atoms;
X = a divalent, optionally branched and/or substituted,
radical, e.g., a saturated or unsaturated hydrocarbon
radical containing at least 2 carbon atoms, optionally
comprising further ester groups;
Y = a trivalent hydrocarbon radical;
Z = a group linking the hydrophobic tail to the oligo-ester
building block, or a covalent bond. Examples of suitable
linking groups are ester groups, ether groups, C-C
single or double bonds
R = the hydrophobic tail.
Alternatively, building blocks having a similar structure but without the X group
can be used. In another embodiment, oxalic acid can be used to introduce the
ester groups. In that case, both Q and X are absent from the building block.
As can be seen in the above structure, the oligo-ester building block contains at
least one ester group and can be linked to other building blocks by ester
groups.
Oligo-ester building blocks wherein Q and X are present to form a ring can for
example be obtained by esterifying cyclic anhydrides or their corresponding

dicarboxylic acids possessing cyclic groups with groups bearing a hydrophobic
tail. The anhydride can for example be a cyclic anhydride of unsaturated,
aromatic and/or saturated cyclic or acyclic dicarboxylic acids. The anhydride
can for example be phthalic anhydride, hexahydrophthalic anhydride, methyl-
hexahydrophthalic anhydride, tetrahydrophthalic anhydride, or mixtures thereof.
Suitable dicarboxylic acids are, for example, the carboxylic acids of the
aforementioned anhydrides or, e.g., 1,3-cyclohexane dicarboxylic acid or 1,4-
cyclohexane dicarboxylic acid, or their cyclopentane or cycloheptane
counterparts.
Acyclic oligo-ester building blocks, wherein X is absent, can be obtained using
for instance succinic anhydride, maleic anhydride, malonic anhydride, the
corresponding dicarboxylic acids, or oxalic acid.
Oligo-ester building blocks wherein X comprises an ester group can for example
be obtained using tricarboxylic acids or their anhydrides, such as trimellitic
anhydride.
Any combination or mixture of the listed acids and/or anhydrides can also be
used to obtain oligo-ester building blocks.
The carboxylic acids or anhydrides can be linked by esterification with a
monoepoxide bearing a hydrophobic tail to form the oligo-ester building block.
Suitable monoepoxides are, for example, epoxidized olefins, such as
cyclohexene oxide or epoxidized a-olefins, e.g., dodecene oxide, tetradecene
oxide, and octadecene oxide; glycidyl ethers, such as ethylhexyl glycidyl ether,
n-butyl glycidyl ether, t-butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl
ether; and the glycidyl esters of carboxylic acids, such as versatic acid glycidyl
ester, e.g., glycidyl neodecanoate, commercially available from Hexion as
Cardura® E10P or mixtures thereof. Other suitable examples are epoxy-
containing aromatic hydrocarbons such as styrene oxide.

Instead of or in addition to monoepoxides, diols can be reacted with the
carboxylic acids or anhydrides to form the oligo-ester building block. Suitable
diols include 1,3-propane diol, 1,2-ethane diol, 1,4-butane diol, 1,5-pentane diol,
1,6-hexane diol, diethylene glycol, triethylene glycol, polyethylene glycols,
dipropylene glycol, and polytetrahydrofuran. Suitable branched diols include
dimethylol propane, neopentyl glycol, 2-propyl-2-methyl-1,3-propane diol, 2-
butyl-2-ethyl-1,3-propane diol, 2,2-diethyl-1,3-propane diol, 1,2-propane diol,
1,3-butane diol, 2,2,4-trimethylpentane-1,3-diol, trimethylhexane-1,6-diol, 2-
methyl-1,3-propane diol, tripropylene glycol, and polyoxypropylene glycols.
Suitable cycloaliphatic diols include 1,4-cyclohexane diol, cyclohexane
dimethanol and cyclic formals of pentaerythritol, and 1,3-dioxane-5,5-
dimethanol. Suitable aralkyl diols include 1,4-xylylene glycol and 1-phenyl-1,2-
ethane diol.
If it is desired to obtain a branched polyester, polyols and/or polyacids may be
used.
Polyols include polyfunctional phenols, triols, and tetrols. Suitable triols include
glycerol, trimethylol propane, trimethylol ethane, trimethylol butane, 3,5,5-
trimethyl-2,2-dihydroxyrnethylhexan-1-ol, and 1,2,6-hexane triol. Alternatively,
cycloaliphatic and aralkyl triols and/or corresponding adducts with alkylene
oxides or derivatives thereof can be used. Suitable tetrols include erythritol,
pentaerythritol, ditrimethylol propane, diglycerol, and ditrimethylol ethane. It is
also possible to use cycloaliphatic and/or aralkyl tetrols as well as
corresponding adducts with alkylene oxides or derivatives thereof. Polyols with
even more hydroxyl groups, such as dipentaerythritol, dulcitol, and threitol, can
also be used. Such polyols are particularly useful as starter molecules to obtain
branched star-shaped molecules.
Suitable polyacids include 1,2,4-butane tricarboxylic acid and trimellitic acid.
Acid alcohols, such as tartaric acid and 2,2-bis(hydroxymethyl) propanoic acid,
can be used additionally or alternatively.

A polyester prepared with pentaerythritol as a starter molecule can have the
following structure:

wherein R is the hydrophobic tail.
Optionally, the polyesters may contain a repetition of oligo-ester building blocks
formed from the alternating reaction of a cyclic anhydride or diacid with a
(mono)epoxide or diol. This can for example be initiated by a monofunctional,
difunctional or polyfunctional starter molecule and can be catalyzed, for
instance by catalysts such as zinc salts, e.g., zinc acetate.
Monoalcohols can for instance be used as a starter molecule. Suitable mono-
functional alcohols for use as starter molecules include linear alcohols, such as
methanol, ethanol, hexanol, butanol, octanol, hexadecanol, etc., branched
alcohols, such as iso-propanol, 2-ethylhexanol, etc., cycloaliphatic alcohols,
such as cyclohexanol, aralkyl alcohols, such as benzyl alcohol, or phenol.

For example, a polyester prepared with 2-ethylhexanol, hexahydrophthalic
anhydride, and a glycidyl ester can have the following structure:

wherein R is the hydrophobic tail, e.g. a hydrocarbon group, and n > 0,
preferably 0-6, more preferably 1-5, and most preferably 2-4. Another example
is a similar polyester with groups derived from glycidyl ethers.
Other possible starter molecules are amines. Suitable primary amines include
monoamines, e.g. alkyl amines such as butyl amine, and diamines, e.g.,
alkylene diamines such as ethylene diamine. Secondary monoamines, such as
piperidine, dialkyl amine, e.g. dibutyl amine, or diamines, such as piperazine,
can also be used.
Suitable carboxylic acid-functional starter molecules include monoacids, such
as 2-ethylbutyric acid, or cyclohexane carboxylic acid, diacids, such as adipic
acid or 1,4-cyclohexane dicarboxylic acid, and polyacids, such as 1,2,4-butane
tricarboxylic acid.
Monothiols, such as dodecane thiol, dithiols, or polythiols, such as
pentaerythritol tetrakis (3-mercaptopropionate), can also be used as starter
molecules. Further, blends of two or more of the aforementioned starter
molecules can be used. Alternatively or additionally, starter molecules of mixed
functionality can be used, such as acid alcohols, amine alcohols, aminoacids,
aminothiols, acid thiols, thiol alcohols or starters having more than two different
functionalities. Suitable acid alcohols include tartaric acid and 2,2-bis-
(hydroxymethyl) propanoic acid. Suitable amine alcohols include

diethanolamine and 1-(2-hydroxyethyl) piperazine. A suitable example of an
acid thiol is 3-mercaptopropanoic acid. A suitable example of a thiol alcohol is
2-thioethanol. Polymeric starters, such as acrylic polyols and acrylic acid
alcohols, may also be used.
If desired, the hydroxy-functional starter molecules may be generated in situ, for
instance via the reaction of an epoxide with a monocarboxylic acid. A suitable
epoxide is for example glycidyl neodecanoate. Other means of generating the
hydroxyl group in situ include the reaction of an epoxide with an amine, thiol or
phenol or the reaction of a cyclic lactone, e.g., £-caprolactone, with an amine,
an alcohol or a thiol.
If a monofunctional starter molecule is used, the resulting polyester will contain
a tail originating from said starter molecule on one end of the polymer chain.
The present invention therefore also relates to a polyester consisting of (i) at
least one, preferably 1-7, more preferably 2-6, and most preferably 3-5 oligo-
ester building blocks with the hydrophobic tail linked thereto, and (ii) a tail
originating from a monofunctional starter molecule on one end of the polymer
chain, said monofunctional starter molecule being selected from the group
consisting of alcohols, amines, carboxylic acids, and thiols. Preferably, the
hydrophobic tail is linked to the oligo-ester building block by an ester group. The
monofunctional starter molecule preferably is a branched mono-alcohol, such
as 2-alkyl alkanol, e.g. 2-ethylhexanol.
So, when the monofunctional starter molecule is 2-ethylhexanol, the resulting
polymer chain will contain a 2-ethylhexyl tail on one end.
The polyester used in the present invention possesses hydrophobic tails. The
term hydrophobic describes the tendency of a molecule or molecular group to
pass out of or not penetrate into water, as defined in ISO 862: 1995. Hydro-
phobic properties of molecules or groups are generally linked to the presence of
hydrocarbon groups. The hydrophobic tails preferably comprise 4-20, more

preferably 6-16, even more preferably 8-10, and most preferably about 9 carbon
atoms. The hydrocarbon tails can be saturated, unsaturated, or aromatic
hydrocarbon groups and they may be branched, linear, or cyclic. The
hydrophobic tails can for example also contain ether and/or ester groups, such
as groups obtainable by the ring opening of e-caprolactone by an acid or an
alcohol. However, it is essential that when the hydrophobic tail is a linear
hydrocarbon linked to the oligo-ester building block via an ester group (i.e. when
Z is an ester group), the linear hydrocarbon contains 3 to 12 carbon atoms.
Preferably, the polyester has an acid value below 20 mg KOH/g, more
preferably below 10 mg KOH/g, most preferably below 5 mg KOH/g. To reduce
the acid value of the end product, an acid-reactive compound, such as a
monoalcohol or monoepoxide, can be used for reaction with the terminal
carboxylic acid groups of the polyester. Suitable compounds include the
monoepoxides and monoalcohols listed above.
Optionally, the polyester resin may have hydroxyl-functional groups. In that
case, they can be reacted in paint systems based on crosslinking with OH-
reactive crosslinkers, such as isocyanates. The polyester preferably has a
hydroxyl value of 0-250 mg KOH/g, more preferably 0-160 mg KOH/g. The
hydroxyl value can be lowered, for example by reaction with OH-reactive
compounds, such as acetic anhydride.
Whereas in WO 03/089522 polyesters with carbamate pigment anchoring
groups are used as dispersants, the polyesters of the present invention are
used as compatibilizer resins and combined with dispersants in the pigment
concentrate. These dispersants typically comprise a polymeric part and one or
more pigment-affinitive groups. Often, these dispersants are built as comb
polymers having one or more polymer chains and one or more pigment-affinitive
groups. Generally, a dispersant with a single polymer chain has a pigment-
affinitive group at a terminal position. Other types of dispersants can have a

backbone with pigment-affinitive groups and have polymeric tails which are
soluble in the solvent to be used. In order to be soluble in organic solvents, the
polymeric tails can for example consist mainly of aliphatic hydrocarbon parts.
Generally, the pigment-affinitive groups are groups with high polarity, e.g. ionic
groups, such as carboxylic, sulphate, sulphonate, amine salts, phosphate or
phosphonate groups. Non-ionic groups, such as carbamate, urea, amide or
amine groups, can also be suitable pigment-affinitive groups. Suitable
dispersants are for instance the Solsperse®, Solplus® and Ircosperse®
dispersants, available from Lubrizol Advanced Materials, the Disperbyk®
dispersants from Byk Chemie, the Efka® dispersants from Ciba, the Tego®
dispersants from Degussa, and the Nuosperse® dispersants from Elementis
Specialies. The amount of dispersant can for example be at least about 0.1% by
weight of the pigments used, e.g., at least about 2% by pigment weight. The
amount of dispersant can for example be below 100% by weight of the
pigments used, e.g., below about 10% by pigment weight.
The pigment concentrate can contain solvents but may also be solvent-free if so
desired. Suitable solvents include for example aromatic solvents, such as
xylene, mesitylene, or the solvents marketed as Solvesso® 100 of Exxon.
Aromatic-free solvents, such as aliphatic hydrocarbon solvents, e.g.
isoparaffins; esters, such as n-butyl acetate; ethers, such as butoxy ethanol;
ether esters, such as methoxy propyl acetate, or ketones, and alcohols, such as
n-butanol, can also be used, as can white spirit. Alternatively or additionally, the
composition may contain non-volatile reactive diluents, such as hexane diol
diglycidyl ether, glycidyl neodecanoate, epoxidized linseed oil or benzyl alcohol,
and/or non-reactive diluents, such as for instance dibutyl phthalate and liquid
aromatic hydrocarbon resins, such as the hydrocarbons of the commercially
available Hirenol® PL and CL series ex Kolon Chemical Company. Mixtures of
any combination of two or more of the aforementioned solvents and/or diluents
can also be used.

The pigments to be used can be inorganic or organic pigments. Examples of
inorganic pigments include titanium dioxide, zinc oxide, carbon black, iron
oxides, bismuth vanadates, raw and burnt sienna or umber, chromium oxide
green, cadmium pigments, and chromium pigments. Examples of organic
pigments include phthalocyanines, quinacridones, anthraquinones, isoindolines,
pyranthrones, indanthrones, derivatives of dioxazine, diketopyrrolopyrroles, and
azo-compounds.
The pigment concentrates of the present invention can also comprise effect
pigments or luster pigments. These are platelet-shaped mono- or multi-layer
pigments showing visual effects marked by the interplay of interference,
reflection, and absorption phenomena. Examples are aluminium platelets and
aluminium, iron oxide, and pearlescent or mica platelets bearing one or more
coats, especially of metal oxides. Dichroic or colour shift pigments can also be
used.
Optionally, filler pigments may be added, such as clay, barytes, silica, talc,
mica, wollastonite, and the like.
High pigment contents can be realized in the pigment concentrates according to
the present invention without the need to increase the solvent content, while
maintaining a satisfactory viscosity. If organic pigments are used, the pigment
content suitably ranges from 5-45% by weight, preferably from 25-40% by
weight, based on the total weight of the pigment concentrate. If inorganic
pigments are used, the pigment content may be more than 30% by weight, e.g.,
40-60% by weight, or even higher, for instance in the case of titanium dioxide. If
translucent pigments, e.g. translucent iron oxides, are used, the pigment
content can be over 5% by weight, preferably over 20% by weight or even over
30% by weight. If carbon black is used, the pigment content may for instance be
10-20% by weight.

Preferably, the pigment concentrate has a volatile organic content VOC not
exceeding 250 g/l, measured according to EPA method 24 of the US
Environmental Protection Agency. Preferably, the VOC of the pigment
concentrate is low enough to allow formulation of paints with a VOC not
exceeding 100 g/l.
Optionally, the pigment concentrate comprises an additional resin, such as an
acrylate resin or a urea-aldehyde resin. Suitable acrylic resins are for instance
Setalux® 1385-51 available from Nuplex Resins. The mixing ratio between the
additional resin and the polyester is preferably 0:1 - 4:1, more preferably 1:1 -
3:1.
The pigment concentrate according to the present invention can for example be
prepared by grinding a pigment with a dispersant. The polyester is added during
or after grinding. Optionally, further resins, such as an acrylic resin, may be
added during or after grinding.
The pigment concentrate according to the present invention is suitable to tint
various types of base paints. The base paints can be based on inorganic
binders, such as polysiloxanes, or organic binders, such as acrylates,
polyesters, alkyds or polyurethanes, or mixtures or hybrids thereof. Solvent
borne base paints can for example be based on aliphatic or aromatic solvents.
The pigment concentrate according to the invention can also be used in toner
systems as described above.
The invention is further illustrated by the following examples.

EXAMPLES
Materials
In these examples the compositions listed below are available as indicated.
Bayferrox® Yellow 3920 yellow iron oxide pigment, of Bayer;
Cardura® E10P glycidyl neodecanoate, available from Hexion;
Dowanol® PM Acetate 1-methoxy-2-propyl acetate, available from
Dow;
Disperbyk® 170 dispersant, available from Byk Chemie;
Fascat®4101 butyl chlorotin dihydroxide catalyst, available
from Arkema;
Intermediate® 3074 polysiloxane, available from Dow Corning;
Irgazin® Red 2030 red pigment, available from Ciba Specialty
Chemicals;
Laropal® A81 urea aldehyde resin, available from BASF;
Monastral® Blue CSN blue copper (II) phthalocyanine pigment,
available from Heubach;
Setal®164, polyester polyol resin, available from Nuplex
Resins;
Setalux® 1161 acrylate, available from Nuplex Resins;
Setalux® 1385-51 acrylic polyol, available from Nuplex Resins;
Solsperse® 38500 pigment synergist, available from Lubrizol
Advanced Materials;
Solsperse® 5000 dispersant, available from Lubrizol Advanced
Materials;
Special Black 100 carbon black, available from Degussa;
Sunfast® Blue 15.2 blue pigment, available from Sun Chemical;
Synocure® 892 BA70 acrylic polyamine, available from Cray Valley;
Tioxide®TR92 titanium dioxide pigment, available from
Huntsman;

Trigonox®21 tert-butyl peroxy-2-ethyl hexanoate, available
from Akzo Nobel Chemicals.
In the Examples, all amounts are in grams, unless indicated otherwise.
Example 1
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 104.3 g of neopentyl
glycol were mixed with 308.7g of hexahydrophthalic anhydride. The mixture was
heated to 150°C and kept at 150°C for 1 hour. Then 52.1 g of neopentyl glycol
were added together with 0.23 g of Fascat® 4101. The mixture was heated to
200°C and kept at 200°C for approximately 6 hours, after which it was cooled to
150°C and 0.38 g triphenyl phosphine was added. Then 212.2 g of Cardura®
E10P were added over 3 hours whilst maintaining the reaction at 150°C. After
the addition of the Cardura® E10P the mixture was kept at the same
temperature until an acid value Example 2
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 90.7 g of neopentyl
glycol were mixed with 268.4 g of hexahydrophthalic anhydride. The mixture
was heated to 150°C and kept at 150°C for 1 hour. Then 62.8 g of cyclohexane
dimethanol were added together with 0.21 g of Fascat® 4101. The mixture was
heated to 200°C and kept at 200°C for approximately 4 hours, after which it was
cooled to 150°C and 0.4 g triphenyl phosphine was added. Then 209.6 g of
Cardura® E10P were added over 2 hours whilst maintaining the reaction at
150°C. After the addition of the Cardura® E10P the mixture was kept at the
same temperature until an acid value

Example 3
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 71.6 g of 2-butyl-2-
ethyl-1,3-propanediol were mixed with 192.5 g cyclohexane-1,2-dicarboxylic
acid and 0.13 g of Fascat® 4101. The mixture was heated to 200°C and kept at
this temperature for 1 hour, after which it was cooled to 150°C and 0.55 g of
triphenyl phosphine was added. Then 301.5g of Cardura® E10P were added
over 2 hours whilst maintaining the reaction at 150°C. The mixture was kept at
the same temperature for a further 2 hours until an acid value was obtained.
Example 4
In a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser,
a nitrogen inlet, and a heating mantle, 31.6 g of 2-butyl-2-ethyl-1,3-propanediol
were mixed with 79.4 g of hexahydrophthalic anhydride. The mixture was
heated to 140°C and kept at this temperature for 1 hour, after which 0.25 g of
triphenyl phosphine was added. Then 142.2 g of Cardura® E10P were added
over 2 hours whilst maintaining the reaction at 140°C. Then the mixture was
kept at the same temperature until an acid value Example 5
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle, 53.4 g of 2-ethylhexanol were mixed with
252.6 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and
kept at the same temperature for 1 hour, after which 0.7 g of triphenyl
phosphine was added. 393.3 g of Cardura® E10P were then added over 4 hours
whilst maintaining the reaction at 150°C. After the addition of the Cardura®
E10P, the mixture was kept at the same temperature until an acid value KOH/g was obtained.

Example 6
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle, 50.0 g of 2-ethylhexanol were mixed with
236.8 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and
kept at the same temperature for 1 hour, after which 0.57 g of triphenyl
phosphine was added. Then 286.1 g of 2-ethylhexyl glycidyl ether were added
over 4 hours whilst maintaining the reaction at 150°C. After the addition of the
Cardura® E10P, the mixture was kept at the same temperature until an acid
value Example 7
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle, 69.9 g of pentaerythritol were mixed with
316.6 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and
kept at the same temperature for 1 hour, after which 0.91 g of triphenyl
phosphine was added. Then 513.5 g of Cardura® E10P were added over 2.5
hours whilst maintaining the reaction at 150°C. After the addition of the
Cardura® E10P, the mixture was kept at the same temperature until an acid
value Example 8
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle, 72.5 g of pentaerythritol were mixed with
328.4 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and
kept at the same temperature for 1 hour, after which 0.98 g of triphenyl
phosphine was added. 533.3 g of 2-ethylhexyl glycidyl ether were added over 4
hours whilst maintaining the reaction at 150°C. Subsequently, the mixture was
kept at the same temperature until an acid value

Example 9
An amount of 87.8 g of hexahydrophthalic anhydride was charged into a 0.5-
litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle. The charge was heated to 50°C and 18.4 g
of dibutyl amine were added over 30 minutes. The mixture was heated to 150°C
and kept at 150°C for 1 hour, after which 0.25 g of triphenyl phosphine was
added. 136.7 g of Cardura® E10P were then added to the mixture over 4 hours
whilst maintaining the reaction at 150°C. Subsequently, the mixture was kept at
the same temperature until an acid value Example 10
An amount of 20.8 g of dibutyl amine was charged into a 0.5-litre reaction flask
equipped with a stirrer, a thermocouple, a condenser, a nitrogen inlet, and a
heating mantle. The reactor flask was heated to 80°C and 38.6 g of Cardura®
E10P were added over 1 hour whilst maintaining the temperature at 80°C. The
mixture was then heated to 125°C for 4 hours. The reaction was cooled to 60°C
and 74.4 g of hexahydrophthalic anhydride were added. The mixture was
heated to 150°C and kept at the same temperature for 1 hour, after which 0.25
g of triphenyl phosphine was added. Subsequently 115.9 g of Cardura® E10P
were added over 2.5 hours whilst maintaining the reaction at 150°C. After the
addition of the Cardura® E10P, the mixture was kept at the same temperature
until the acid value was below 5 mg KOH/g.
Example 11
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 73.3 g of 2-butyl-2-
ethyl-1,3-propanediol were mixed with 98.5 g of cyclohexane-1,2-dicarboxylic
acid, 98.5 g of cyclohexane-1,4-dicarboxylic acid, and 0.14 g of Fascat® 4101.
The mixture was heated to 200°C and kept at this temperature for 1 hour, after
which it was cooled to 150°C and 0.54 g of triphenyl phosphine was added.
Then 286.6 g of Cardura® E10P were added over 2 hours whilst maintaining the

reaction at 150°C. The mixture was kept at the same temperature until an acid
value Example 12
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 41.7 g of 2,2-
bis(hydroxymethyl) propanoic acid were mixed with 239.0 g of hexahydro-
phthalic anhydride and 0.7 g of triphenyl phosphine. The mixture was heated to
150°C and kept at 150°C for a further hour. Then 425.5 g of Cardura® E10P
were added over 3 hours whilst maintaining the reaction at 150°C. The mixture
was kept at the same temperature until an acid value obtained.
Example 13
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
Dean-Stark trap, a nitrogen inlet, and a heating mantle, 129.4 g of hexahydro-
phthalic anhydride were mixed with 302.4 g of Cardura® E10P and 0.43 g of
zinc acetate. The mixture was heated to 90°C and kept at this temperature for 4
hours. The acid value of the product was Example 14
Into a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a
condenser, a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 227.6 g of
the polyester prepared according to Example 7 were charged and heated to
100°C. Then 54.3g of acetic anhydride were added and the mixture was kept at
120°C for 2 hours. The mixture was then heated to 150°C and acetic acid
collected in the Dean-Stark trap. The mixture was heated at the same
temperature until an acid value

Example 15
In a 500 ml reaction flask equipped with a stirrer, a thermocouple, a condenser,
a nitrogen inlet, and a heating mantle, 45.1 g of 2-ethylhexanol were mixed with
80.1 g of hexahydrophthalic anhydride. The mixture was heated to 150°C and
kept at the same temperature for 1 hour, after which 0.25 g of triphenyl
phosphine was added. 124.6 g of Cardura® E10P were then added over 3 hours
whilst maintaining the reaction at 150°C. After the addition of Cardura® E10P,
the mixture was kept at the same temperature until an acid value KOH/g was obtained.
Example 16
In a 0.5-litre reaction flask equipped with a stirrer, a thermocouple, a condenser,
a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 37.6 g of trimethylol
propane, 21.6 g of hexahydrophthalic anhydride, and 0.03 g of Fascat® 4101
were mixed and heated to 200°C and kept at 200°C for 4 hours. The mixture
was then cooled to 120°C and 86.3 g of hexahydrophthalic anhydride were
added and the whole was kept at 120°C for a further 2 hours. The mixture was
then heated to 150°C and 0.27 g of triphenyl phosphine was added. 134.3 g of
Cardura® E10P were then added over 3 hours whilst maintaining the
temperature at 150°C. After the addition of the Cardura® E10P, the mixture was
kept at the same temperature until an acid value Example 17
Into a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser,
a Dean-Stark trap, a nitrogen inlet, and a heating mantle, 177.0 g of 1-methoxy-
2-propyl acetate (Dowanol® PM Acetate) were charged and heated to 150X.
Then 93.9 g of hydroxypropyl methacrylate, 90.0 g of butyl methacrylate, 60.0 g
of methyl methacrylate, 8.8 g of 1-octanethiol, and 6.5 g of tert-butyl peroxy-2-
ethylhexanoate (Trigonox® 21, available from Akzo Nobel Chemicals) were
added to a 1-litre conical flask. This mixture was added to the reactor over 3
hours, whilst maintaining the temperature of the reaction at 150°C. The mixture

was kept at 150°C for a further hour and 5.0 g of Trigonox® 21 were then
added. The reaction was kept at 150°C for another hour. The mixture was then
cooled to 80°C and 100.5 g of hexahydrophthalic anhydride were added. The
temperature of the mixture was then increased to 150°C and kept there for 2
hours, after which 0.51 g of triphenyl phosphine was added. Then 162.9 g of
Cardura® E10P were added over 2 hours whilst maintaining the reaction at
150°C. After the addition of the Cardura® E10P, the mixture was kept at the
same temperature until an acid value Example 18
In a 1-litre reaction flask equipped with a stirrer, a thermocouple, a condenser, a
nitrogen inlet, and a heating mantle, 69.9 g of pentaerythritol were mixed with
205.5 g of succinic anhydride. The mixture was heated to 150°C and kept at the
same temperature for 1 hour, after which 0.91 g of triphenyl phosphine was
added. Then 513.5 g of Cardura® E10P were added over 2.5 hours whilst
maintaining the reaction at 150°C. After the addition of the Cardura® E10P, the
mixture was kept at the same temperature until an acid value was obtained.
Compatibility evaluation of the resins of Examples 1 -15
To test the compatibility of the compatibilizer resins of Examples 1-15 with a
range of base paint binder systems, the following evaluation procedure was
carried out.
The evaluation was carried out with the following base resins: an acrylic polyol,
an oxidatively drying alkyd based on tall oil fatty acid and pentaerythritol with an
oil length of 64%, an acrylic polyamine, Synocure® 892 BA70 available from
Cray Valley, and a polysiloxane (Dow Corning® 3074 Intermediate).
The base resins and the compatibilizer resins were mixed in a mixing ratio of
10:1. Approximately 0.25 g of the compatibilizer resin was weighed accurately

into four glass vials. Into each vial approximately 2.5 g of the required base
resin were then weighed accurately. Then into each vial approximately 2.75g of
the solvent (1 -methoxy-2-propyl acetate) were weighed accurately. The
samples were mixed until completely dissolved. In the case of the vial
containing Dow Corning® 3074 Intermediate, 0.125 g of 3-aminopropyl
triethoxysilane and 0.05 g of dibutyl tin dilaurate were added. Then films were
applied for all samples using a 400 urn film applicator bar on a glass panel and
stored at 25°C for 24 hours. The tests were repeated with a storage
temperature of 10°C. The compatibility was evaluated visually and categorized
as either OK (clear film), slightly cloudy or cloudy.
In all cases, the films remained clear and no cloudiness was observed,
indicating that the compatibilizer resins are fully compatible with the various
binder resins.
Compatibility evaluation of the resin of Example 18
The compatibility of the compatibilizer resin of Example 18 was tested with the
following resins: acrylic resins Setalux® 1385 and Setalux® 1161 available from
Nuplex Resins, Setal® 164, a polyester polyol resin available from Nuplex
Resins, and a blend of two cellulose acetate butyrate resins available from
Eastman Chemical Company.
Each resin, or resin blend in the case of the cellulose acetate butyrates, was
mixed with the compatibilizer resin in a 100 ml glass bottle using a mixing ratio
of 10:1. To 1 g of compatibilizer resin were added 10 g of the resin being tested.
Then to each bottle 11 grams of 1-methoxy-2-propyl acetate solvent were
added. The bottles were shaken vigorously until the resin sample had dissolved.
The samples were initially judged in the bottle for any indication of
incompatibility such as phase separation or haziness. After storage at 25°C for
24 hours all the samples appeared homogenous and clear. The samples were

then applied as a wet film using a 200-micron applicator bar on acetate sheets
and stored at 25°C for 24 hours. The drawdowns were evaluated visually and
categorized as either OK (clear film), slightly cloudy or cloudy. In all cases the
resin films remained clear and no cloudiness was observed, which
demonstrates that the compatibilizer resin is fully compatible with the tested
resins.
Viscosity
A pigment concentrate was formulated comprising 25 wt.% of a blue pigment,
Sunfast® Blue 15.2, 15 wt.% of a 30% solution of the polyester prepared in
Example 7, 26 wt.% of a thermosetting acrylic resin, Setalux® 1385 BX51, 24
wt.% of a dispersant, Disperbyk® 170, and 10 wt.% of butyl acetate solvent. The
solid content was about 50 wt.%. The pigment to binder ratio was about 1.
Zirconia beads (200 g) of diameter 1.25 - 1.6 mm were added to a glass bottle
of volume 370 ml. Next, 125 g of the pigment paste premix were added to the
bottle. A further 190 g of the zirconia beads were added. A screwtop lid was
fitted and the bottle placed in a shaker. The bottle was shaken for 90 minutes in
order to achieve a pigment paste Hegman grind of The paste viscosity was measured using a CAP2000 cone and plate viscometer
at a shear rate of 75 rpm and 750 rpm, respectively. At a shear rate of 75 rpm,
the paste had a viscosity of 2.0 - 2.5 cPs, while the 750 rpm viscosity was 1.5 -
1.8 cPs. This means that although the pigment content was more than 30%
higher than that of the prior art pastes, the viscosity was still lower.
Determination of achievable VOC
Pigment concentrates were prepared using the compatibilizer resins of
Examples 1, 2, 3, 5, 7, and 14. A comparative test was carried out using
Laropal® A81, available from BASF. In the pigment concentrates Solsperse®
38500, available from Noveon Performance Coatings, was used as a

dispersant. The evaluation was carried out with the following pigments- a
titamum dioxide (Tioxide® TR92, available from Huntsman), yellow iron oxide
(Bayferrox® Yellow 3920 of Bayer), carbon black (Special Black 100, available
from Degussa), a blue copper (II) phthalocyanine pigment (Monastral® Blue
CSN, available from Heubach), and a red pigment (Irgazin® Red 2030, available
from Ciba Specialty Chemicals).
The pigment concentrates were prepared by dissolving the compatibilizer resins
in 1-methoxy-2-propyl acetate. The compatibilizer resin solution was then mixed
with further solvent and the dispersant, Solsperse® 38500. Pigment was added
under agitation at a temperature of 40°C. Glass beads of 1 mm diameter were
added in a 1:1 weight ratio with respect to the total colorant weight. For the
Bayferrox® Yellow 3920 colorant, a 1:1.4 weight ratio was used. The mixture
was then mixed with a speed of 8,000 - 10,000 rpm and filtered using a 250 urn
polyester mesh for separation from the grinding media. In all cases the product
was a fluid, pourable pigment concentrate. Table 1 shows that a VOC of 250 g/l
or less can be achieved. Table 2 shows the formulations of the pigment
concentrates.

CLAIMS
1. Non-aqueous pigment concentrate comprising one or more pigments,
one or more dispersants, and at least one resin, characterized in that the
resin is a polyester comprising at least one oligo-ester building block with
a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected
from the group consisting of:
- branched hydrocarbons,
- hydrocarbons containing a cyclic group, and
- linear hydrocarbons, provided that when said linear hydrocarbon is
linked to the oligo-ester building block via an ester group, the linear
hydrocarbon contains 3 to 12 carbon atoms.

2. Pigment concentrate according to claim 1, wherein at least part of said
oligo-ester building blocks is obtainable from a cyclic carboxylic
anhydride or an ester-forming derivative thereof.
3. Pigment concentrate according to claim 2, wherein the cyclic carboxylic
anhydride is hexahydrophthalic anhydride.
4. Pigment concentrate according to any one of claims 1-3, wherein at least
part of the oligo-ester building blocks is obtainable by reacting a
dicarboxylic acid or a carboxylic anhydride with a monoepoxide.
5. Pigment concentrate according to claim 4, wherein the monoepoxide is a
glycidyl ester of an aliphatic acid.
6. Pigment concentrate according to claim 4, wherein the monoepoxide is a
glycidyl ether.

7. Pigment concentrate according to any one of the preceding claims,
wherein the resin comprises at least one group originating from a mono-,
di- or polyfunctional compound selected from the group of alcohols,
amines, carboxylic acids, or thiols.
8. Pigment concentrate according to claim 7, wherein said compound is
selected from the group consisting of 2-ethylhexanol, neopentyl glycol,
trimethylol propane, trimethylol ethane, trimethylol butane, 3,5,5-
trimethyl-2,2-dihydroxymethylhexane-1-ol, glycerol, 1,2,6-hexane triol,
erythritol, pentaerythritol, dipentaerythritol, ditrimethylol propane,
diglycerol, and ditrimethylol ethane.
9. Pigment concentrate according to claim 7, wherein the resin comprises
on one end of the polymer chain a tail originating from a monofunctional
compound selected from the group of alcohols, amines, carboxylic acids,
or thiols.
10. Pigment concentrate according to any one of the preceding claims,
wherein the concentrate has a volatile organic content VOC not
exceeding 250 g/l.
11. Pigment concentrate according to any one of the preceding claims,
further comprising an additional resin.
12. Pigment concentrate according to claim 11, wherein the additional resin
is an acylate resin.
13. Process to prepare a polyester with hydrophobic tails by reacting one or
more monoepoxides with one or more dicarboxylic acids or anhydrides
and a monofunctional starter molecule selected from the group of
alcohols, amines, carboxylic acids, or thiols.

14. Process according to claim 13, wherein the starter molecule is a
branched mono-alcohol, such as a 2-alkyl alkanol, e.g., 2-ethylhexanol.
15. Process according to claim 13 or 14, wherein at least part of the starter
molecule is formed in situ.
16. Polyester consisting of (i) at least one oligo-ester building block with a
hydrophobic tail linked thereto and (ii) a tail originating from a
monofunctional compound on one end of the polymer chain, said mono-
functional compound being selected from the group consisting of
alcohols, amines, carboxylic acids, and thiols.
17. Polyester according to claim 16, wherein the monofunctional compound
is 2-ethylhexanol.
18. Coating composition comprising the polyester of claim 15 or 16.

19. Use of the pigment concentrate of any one of claims 1-12 in a coating
composition.
20. Method for preparing the pigment concentrate of any one of claims 1-12
by grinding the one or more pigments with the one or more dispersants
and adding the resin during or after grinding.

Non-aqueous pigment concentrate comprising one or more pigments, one or more dispersants, and at least one resin, characterized in that the resin is a polyester comprising at least one oligo-ester building block with a hydrophobic tail linked thereto, wherein the hydrophobic tail is selected from the group consisting of: (a) branched hydrocarbons, (b) hydrocarbons containing a cyclic group, and (c) linear hydrocarbons, provided that when said linear hydrocarbon is linked to the oligo-ester building block via an ester group, the linear hydrocarbon contains 3 to 12 carbon atoms.

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Patent Number

269237

Indian Patent Application Number

1469/KOLNP/2009

PG Journal Number

42/2015

Publication Date

16-Oct-2015

Grant Date

12-Oct-2015

Date of Filing

20-Apr-2009

Name of Patentee

AKZO NOBEL COATINGS INTERNATIONAL B. V.

Applicant Address

VELPERWEG 76, NL-6824 BM ARNHEM

Inventors:

#	Inventor's Name	Inventor's Address
1	GANESH, BHUVANESWARAN	C/O AKZO NOBEL CAR REFINISHES (1) PVT. LTD., INTERNATIONAL RESEARCH CENTRE, PLOT NO. 62P, HOSKOTE INDUSTRIAL AREA, HOSKOTE, BANGALORE 562144
2	VAN DEN HAAK, HENDRIK JAN WILLEM	VLIEGENIERSWEG 46, NL-2171 PC SASSENHEIM
3	DI LULLO, CLAUDIO ARGENTINO	BURNT WALLS FARM, GREENHEAD BRAMPTON CA8 7HX
4	CAMERON, COLIN	20 BIRKDENE, STOCKSFIELD NORTHUMBERLAND NE43 7EN
5	SOLDAVINI, LORENZO	VIA AOSTA 9, I-20020 GALLARATE (VA)
6	ROY, JAMIE MACLIVER	MULTATULIPLEIN 7, NL-2332 EC LEIDEN

PCT International Classification Number

C09B 67/00

PCT International Application Number

PCT/EP2007/060079

PCT International Filing date

2007-09-24

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	06123764.0	2006-11-09	India
2	60/858,290	2006-11-10	India
3	981/KOL/2006	2006-09-26	India