Polyurethane dispersant

Abstract

The invention relates to a polymer comprising: a) a core comprising at least one of urethane or isocyanurate groups based on a linear aliphatic diisocyanate, and b) an average of 2.6 to 6.0 pendant groups covalently linked to the core via a group comprising at least one of a urethan group and a urea group, wherein the pendant groups comprise i) hydrocarbyl groups having 6 to 40 carbon atoms, ii) hydrocarbyl terminated polyether groups, and iii) at least one of tertiary amine groups and slats of tertiary amine groups.

Description

[0001] POLYURETHANE DISPERSANT

[0002] The invention relates to a polymer comprising a core and pendant groups, to the use of the polymer as a dispersant for solid particles, to a composition comprising the polymer and solid particles dispersed in the composition, and to a process of dispersing solid particles in a dispersion medium.

[0003] US 2011 / 0021699 A relates to addition compounds and salts thereof that are suitable as wetting agents and dispersants. The addition compounds are prepared by reacting a polyisocyanate, a polyetheralcohol, optionally a polyol, and a tertiary amine-functional alcohol or amine.

[0004] US 2016 / 0257848 A relates to a polyurethane resin system. The resin system comprises a cardanol-modified epoxy polyol and a polyisocyanate.

[0005] US 2016 / 0083502 A pertains to an addition compound, prepared by reacting a a) polyisocyanate, b) one or more compounds selected from polyester, polyether, polyacrylate, polyurethane, and polyolefin, and having at least one amino group, and c) one or more compounds selected from N-(3-aminopropyl)imidazole, benzoguanamine, and N-(2-amino- ethyl)piperazine.

[0006] There is an ongoing need for new and improved dispersants for pigments and fillers used in coating compositions. In particular, there is a need for dispersants having a low viscosity and which need a low amount or no solvent to dilute them to a required application viscosity. Moreover, it is desirable to have dispersants which can be used in water-based compositions as well an inorganic solvent-based liquid compositions. In a further aspect, dispersants should be suitable for a variety of different pigments and fillers, for examples organic pigments and inorganic pigments. The invention seeks to provide dispersants which lead to improvements in one or more of the above-mentioned aspects.

[0007] The invention provides a polymer comprising a) a core comprising at least one of urethane or isocyanurate groups based on a linear aliphatic diisocyanate, and b) an average of 2.6 to 6.0 pendant groups covalently linked to the core via a linking group comprising at least one of a urethane group and a urea group, wherein the pendant groups comprise i) hydrocarbyl groups having 6 to 40 carbon atoms, ii) hydrocarbyl terminated polyether groups, and iii) at least one of tertiary amine groups and salts of tertiary amine groups.

[0008] The polymer of the invention is very suitable as dispersant for solid particles. The polymer provides one or more of the following advantages. The polymer has a low viscosity and / or needs a low amount of solvent to achieve a required application viscosity. The polymer is suitable as a dispersant for a variety of different pigments and fillers, for examples organic pigments and inorganic pigments. The polymer can be used as a dispersant in water-based compositions as well an in organic solvent-based liquid compositions. Thus, the polymer is universally suitable to be used for both organic and inorganic pigments and in water-based as well as in solvent-based compositions, in each case providing high-performance properties.

[0009] The polymer of the invention comprises a core comprising at least one of urethane or isocyanurate groups based on a linear aliphatic diisocyanate.

[0010] In some embodiments, the core comprises a plurality of urethane groups. Such cores may be obtained by reacting a diisocyanate with a compound having 3 or 4 hydroxyl groups. Examples of suitable diisocyanates include 1 ,2-propylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, 2,3-butylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylene diisocyanate, and co, w’-di propylether diisocyanate. Examples of suitable compounds having 3 or 4 hydroxyl groups are trimethylol propane and pentaerythritol. For preparation of the core, the diisocyanate and the compound having 3 or 4 hydroxyl groups are reacted with a molar excess of isocyanate groups. Specific examples include the adduct of 1 molecule of trimethylol propane to 3 molecules of hexamethylene diisocyanate, the adduct of 1 molecule of trimethylol propane to 3 molecules of 2,2,4-trimethyl hexamethylene diisocyanate, and the adduct of 1 molecule of pentaerythritol to 4 molecules of hexamethylene diisocyanate.

[0011] In other embodiments, the core is based on adducts and oligomers of polyisocyanate, in particular isocyanurate oligomers of diisocyanates. Examples thereof include the isocyanurate trimer of 1,6-diisocyanato hexane and the isocyanurate trimer of 2,2,4-trimethyl hexamethylene diisocyanate.

[0012] In preferred embodiments, wherein the linear aliphatic diisocyanate is hexamethylene diisocyanate. This leads to polymers having low viscosity and having good dispersant properties.

[0013] The polymer of the invention has an average of 2.6 to 6.0 pendant groups covalently linked to the core via a linking group. In some embodiments, the polymer of the invention has an average of 2.8 to 5.0 pendant groups, or 2.8 to 4.5 pendant groups, covalently linked to the core via a linking group.

[0014] The pendant groups of the polymer are covalently linked to the core via a linking group comprising at least one of a urethane group and a urea group. Individual pendant groups may be linked by different linking groups. Generally, each linking group comprises one urea group or one urethane group. In view of achieving a low viscosity of the polymer, it is preferred that at least some of the pendant groups are linked to the core via a urethane group. It is generally preferred that at least 40 %, preferably at least 50 %, of the pendant groups are linked to the core via a urethane linking group. In some embodiments, up to 100 % of the pendant groups are linked to the core via urethane groups.

[0015] The pendant groups comprise hydrocarbyl groups having 6 to 40 carbon atoms. In one embodiment, the hydrocarbyl groups are cycloaliphatic groups or non-cyclic aliphatic groups having 6 to 40 carbon atoms. In a further embodiment, the non-cyclic aliphatic group is a linear aliphatic group or a branched aliphatic group. In a preferred embodiment, the hydrocarbyl groups having 6 to 40 carbon atoms comprise linear aliphatic groups.

[0016] In a still further embodiment, the non-cyclic aliphatic group is a linear or branched aliphatic group comprising at least one olefinically unsaturated group. Suitably, 1 or 2 olefinically unsaturated groups are present.

[0017] In other embodiments the hydrocarbyl groups have 8 to 40 carbon atoms and comprise an aryl group. In preferred embodiments, the aryl group is substituted by a hydrocarbyl group having two to 34 carbon atoms, preferably 8 to 20 carbon atoms. The hydrocarbyl substituent of the aryl group may be saturated or unsaturated. In preferred embodiments, the hydrocarbyl group of the substituent has 1 to 3 olefinically unsaturated groups. Preferred hydrocarbyl substituted aryl groups are based on cardanol, which is a phenolic liquid and a by-product of cashew nut processing.

[0018] Suitably, the polymer of the invention comprises an average of 0.4 to 3.0, preferably 0.5 to 2.0, pendant hydrocarbyl groups.

[0019] The polymer of the invention comprises pendant hydrocarbyl terminated polyether groups. Generally, the polyether groups are non-cyclic ether groups. In preferred embodiments, the polyether groups comprise polymerized units of at least one of ethylene oxide and propylene oxide.

[0020] In some embodiments, the polyether groups consist of polymerized groups of ethylene oxide. In other embodiments, the polyether groups consist of polymerized units of propylene oxide. In further embodiments, the polyether groups consist of polymerized units of ethylene oxide and propylene oxide. In this case, the polymerized units of ethylene oxide and propylene oxide may be present in the form of two or more polymer blocks or in random order.

[0021] Generally, the molar ratio of polymerized groups of ethylene oxide to propylene oxide is in the range of 100:0 to 0:100. In preferred embodiments, the molar ratio of ethylene oxide to propylene oxide is in the range of 70:30 to 30:70, more preferably 60:40 to 40:60.

[0022] The polyether groups are terminated by hydrocarbyl groups. In some embodiments, the terminal hydrocarbyl groups are alkyl groups having 1 to 10 carbon atoms. Typically, the hydrocarbyl groups are linear alkyl groups. In preferred embodiments, the polyether groups are terminated by hydrocarbyl groups having 1 to 4 carbon atoms.

[0023] Suitably, the polymer of the invention comprises an average of 1.0 to 4.0, preferably 1.5 to 3.0, pendant hydrocarbyl terminated polyether groups.

[0024] The polymer of the invention further comprises at least one of tertiary amine groups and salts of tertiary amine groups as pendant groups.

[0025] These groups can suitably be included by reaction of a tertiary amine compound having additionally a hydroxyl group or a secondary or primary amine group with an isocyanate functional group of the core. Examples of suitable tertiary amines include monohydroxy amines having a tertiary amino group, or aliphatic diamines having a tertiary amino group and a primary or secondary amino group, such as, for example, (N,N-diethylamino)ethanol, (N,N-dimethylamino)ethanol, (N,N-dimethylamino)propanol, 2-(diethylamino)ethylamine, 3- (dimethylamino)propylamine, 3-(diethylamino)propylamine, N , N-diethyl- 1 ,4-butanediamine, 1-diethylamino-4-aminopentane, of which 3-(dimethylamino)propylamine and (N,N- diethylamino)ethanol are preferred.

[0026] Further examples are N-(3-aminopropyl)imidazole, N-(3-aminopropyl) morpholine, N-(2- aminoethyl)piperidine, 1 -methylpiperazine, aminoethylpiperazine. It is characteristic of these compounds that they contain per molecule at least 1 reactive group with at least 1 Zerewitinoff hydrogen atom which is able to react with the NCO groups, and that they additionally possess a nitrogen-containing basic group without reactive hydrogen.

[0027] Suitably, the polymer of the invention comprises an average 0.4 to 3.0, preferably 0.5 to 2.0, pendant tertiary amine groups, salts thereof or a combination of pendant tertiary amine groups and salts thereof.

[0028] The polymer of the invention generally has an amine number in the range of 4 to 80 mg KOH / g, preferably 5 to 10 mg KOH / g. The amine number can be determined by titration of a sample of the polymer with perchloric acid in acetic acid according to ISO 25761. The tertiary amine groups are capable of forming salts by reaction with acid. In certain cases, by means of partial or complete salt formation it is possible to obtain an improvement in activity and / or an enhanced solubility or compatibility. Even in applications where the basicity of the products is a disrupting factor, as for example, in acid-catalyzed systems, it is frequently possible to achieve improvements by means of partial or complete neutralization.

[0029] The salts are obtained from the resultant reaction product by neutralization with one or more organic or inorganic acids. The amount of acid to be used is guided by the field of use. Depending on each individual case, the acid components may be used in equimolar, substoichiometric or super-stoichiometric amounts. From polycarboxylic acids, for example, it is also possible to use up to one equivalent of polycarboxylic acid per basic group to be neutralized in order to give the products an acidic character. It is preferred to carry out approximately equimolar neutralization. Preference is given to salts with organic carboxylic acids or acidic phosphoric acid esters such as organic carboxylic acids or acidic phosphoric acid esters having an aliphatic group of 5 to 10 carbons. Examples of such acidic phosphoric acid esters are given in EP 893 155, EP 417490 and U.S. Pat. No. 5,143,952. The acid phosphoric ester may be an acidic polyphosphoric acid ester.

[0030] Examples of carboxylic acids are aliphatic and / or aromatic carboxylic acids such as shortchain or long-chain fatty acids, preferably fatty acids having 5 to 10 carbons, formic acid, acetic acid, neodecanoic acid, oleic acid, tall oil fatty acid, stearic acid, ricinoleic acid, natural saturated or unsaturated plant or animal fatty acids and their maleic anhydride adducts, maleic acid, fumaric acid, succinic acid, dodecenylsuccinic acid, 5-norbornene-2,3- dicarboxylic acid, adipic acid, glutaric acid, benzoic acid, nitrobenzoic acid, phthalic acid, tetrahydrophthalic acid, isophthalic acid, terephthalic acid, dimerized or trimerized fatty acids, citric acid and abietic acid. In further embodiments, a sulfonic acid is used as neutralizing agent, for example toluene sulfonic acid or dodecyl sulfonic acid.

[0031] The acidic phosphoric acid ester suitably has an acid value in the range of 500 to 700 mg KOH / g, preferably 550 to 650 mg KOH / g. The carboxylic acid suitably has an acid value in the range of 300 to 500 mg KOH / g.

[0032] The polymer of the invention suitably has a number average molecular weight in the range of 1000 g / mol to 40000 g / mol, preferably 4000 g / mol to 18000 g / mol. The number average molecular weight can be determined by gel permeation chromatography using a polystyrene calibration and tetrahydrofuran as eluent.

[0033] The polymer of the invention is suitably prepared by a process comprising the steps: a) providing a polyfunctional core comprising at least one of urethane or isocyanurate groups based on a linear aliphatic diisocyanate, and having an average of 2.6 to 6.0 isocyanate groups, b) combining the polyfunctional core with i) a compound consisting of a hydrocarbyl group having 6 to 40 carbon atoms and one hydroxyl group or one secondary or primary amine group, ii) a polyether compound having a terminal hydrocarbyl group and second terminal group which is a hydroxyl group or a primary or secondary amine group, and, iii) a tertiary amine compound having additionally a hydroxyl group or a secondary or primary amine group, c) reacting the isocyanate groups of the polyfunctional core with the compounds provided in step b).

[0034] The polyfunctional core is typically a polyisocyanate. Suitable polyisocyanates are those described above in relation to the core, in particular isocyanurate trimers and oligomers based on diisocyanates.

[0035] Suitable monoalcohols include those having the formula R-OH, wherein R represents a hydrocarbyl group having 6 to 40 carbon atoms. Suitable and preferred hydrocarbyl groups are as defined above. Urethane links are formed when the isocyanate groups of the polyfunctional core react with hydroxyl groups of a monoalcohol.

[0036] Suitable monoamines include those of the formula R-NH2 and R2-NH, wherein R represents a hydrocarbyl group having 6 to 40 carbon atoms. Suitable and preferred hydrocarbyl groups are as defined above. Urea links are formed when the isocyanate groups of the polyfunctional core react with amine groups of a monoamine.

[0037] Suitable polyether compounds having a terminal hydrocarbyl group and second terminal group which is a hydroxyl group or a primary or secondary amine group are generally linear polyethers, terminated by a hydrocarbyl group, such as a butyl or methyl group, at one end and terminated by a hydroxyl or primary or secondary amine group at the other end. Other features of such compounds are as described above for the hydrocarbyl terminated polyether groups.

[0038] Suitable tertiary amine compounds having additionally a hydroxyl group or a secondary or primary amine group are those mentioned above. In the process of preparing the polymer of the invention the components i), ii) and iii) can be combined in step b) with the polyfunctional core in any suitable order. It is also possible to add a premix of two or more of the components to the polyfunctional core. In a further embodiment, it is possible to react one or more of the components i), ii) or iii) partially or completely with the isocyanate groups of the polyfunctional core before adding any remaining components and reacting these with the isocyanate groups.

[0039] In the process of preparing the polymer of the invention the molar ratio of isocyanate groups to isocyanate-reactive groups is selected in such a way that the resulting product is free or essentially free of isocyanate groups. This is generally achieved when the molar ratio of isocyanate groups to isocyanate-reactive groups in the in the range 0.9 to 1.10.

[0040] As mentioned above, the polymer of the invention is very suitable as a dispersant for solid particles. Therefore, the invention relates to the use of the polymer according to the invention as a dispersant for solid particles.

[0041] In preferred embodiments, the solid particles comprise at least one of filler particles and pigment particles.

[0042] Pigments used are the pigments known to those skilled in the art. Frequently, combinations of various pigments are used to obtain the desired properties. Examples of pigments are monoazo, diazo, triazo and polyazo pigments, oxazine pigments, dioxazine pigments, thiazine pigments, diketopyrrolopyrroles, phthalocyanines, ultramarine and other metal complex pigments, indigoid pigments, diphenylmethane pigments, triarylmethane pigments, xanthene pigments, acridine pigments, quinacridone pigments, methine pigments, anthraquinone, pyranthrone pigments and perylene pigments and other polycyclic carbonyl pigments, inorganic pigments such as carbon black pigments and / or pigments based on carbon black, graphite, zinc, titanium dioxide, zinc oxide, zinc sulfide, zinc phosphate, barium sulfate, lithopone, iron oxide, ultramarine, manganese phosphate, cobalt aluminate, cobalt stannate, cobalt zincate, antimony oxide, antimony sulfide, chromium oxide, zinc chromate, mixed metal oxides based on nickel, bismuth, vanadium, molybdenum, cadmium, titanium, zinc, manganese, cobalt, iron, chromium, antimony, magnesium, aluminum (for example nickel titanium yellow, bismuth vanadate molybdate yellow or chromium titanium yellow), magnetic pigments based on pure iron, iron oxides and chromium oxides or mixed oxides, metal effect pigments comprising aluminum, zinc, copper or brass and also pearlescent pigments or fluorescent and phosphorescent luminous pigments. Further examples are nanoscale organic or inorganic solids having particle sizes below 100 nm in at least one dimension, such as certain types of carbon black or other allotropic forms of carbon, such as single-wall CNTs, multiwall CNTs and graphene. The particle size is determined, for example, by means of transmission electron microscopy, analytical ultracentrifugation or methods of light scattering. Mention should likewise be made of particles consisting of a metal or semimetal oxide or hydroxide, and also particles consisting of mixed metal and / or semimetal oxides or hydroxides. For example, the oxides and / or oxide hydroxides of aluminum, silicon, zinc, titanium, etc., can be used to produce such extremely finely divided solids. These oxide or hydroxide or oxi de- hydroxi de particles can be produced by a wide variety of different processes, for example ion exchange processes, plasma processes, sol-gel processes, precipitation, comminution (for example by grinding) or flame hydrolysis. All the aforementioned pigments may be in surface-modified form and have basic, acidic or neutral groups at the surface.

[0043] Further examples are the following pigments listed under their Color Index number (C.I.):

[0044] Examples of red pigments are C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 50:1, 52:1, 52:2, 53, 53:1, 53:2, 53:3, 57, 57:1, 57:2, 58:4, 60, 63, 63:1, 63:2, 64, 64:1, 68, 69, 81, 81:1, 81:2, 81:3 ,81:4, 83, 88, 90:1, 101, 101:1, 104 ,108, 108:1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151, 166, 168, 169, 170, 172, 173, 174, 175, 176, 177, 178, 179, 181, 184, 185,

[0045] 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 216, 220, 221, 224, 230,

[0046] 231, 232, 233, 235.236, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255,

[0047] 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274,

[0048] 275, and 276.

[0049] Examples of blue pigments are C. I. Pigment Blue 1, 1:2, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 19, 25, 27, 28, 29, 33, 35, 36, 56, 56:1, 60, 61, 61:1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, and 79.

[0050] Examples of green pigments are C. I. Pigment Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 45, 48, 50, 51 , 54, 55, 58 or 59.

[0051] Examples of yellow pigments are C. I. Pigment Yellow 1, 1:1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 41, 42, 43, 48, 53, 55, 61, 62, 62:1,

[0052] 63, 65, 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116,

[0053] 117, 119, 120, 126, 127, 127:1, 128, 129, 133, 134, 136, 138, 139, 142, 147, 148, 150, 151, 153, 154, 155, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 172,

[0054] 173, 174, 175, 176, 180, 181, 182, 183, 184, 185, 188, 189, 190, 191, 191:1, 192, 193, 194,

[0055] 195, 196, 197, 198, 199, 200, 202, 203, 204, 205, 206, 207, and 208. Examples of violet pigments are C. I. Pigment Violet 1 , 1 :1 , 2, 2:2, 3, 3:1 , 3:3, 5, 5:1 , 14, 15, 16, 19, 23, 25, 27, 29, 31 , 32, 37, 39, 42, 44, 47, 49, and 50.

[0056] Examples of orange pigments are C. I. Pigment Orange 1 , 2, 5, 13, 16, 17, 19, 20, 21 , 22, 23, 24, 34, 36, 38, 39, 43, 46, 48, 49, 61 , 62, 64, 65, 67, 68, 69, 70, 71 , 72, 73, 74, 75, 77, 78, and 79.

[0057] Examples of black pigments are C. I. Pigment Black 7, 11 , 30, 33.

[0058] Examples of pulverulent or fibrous fillers are, for example, those formed from pulverulent or fibrous particles of aluminum oxide, aluminum hydroxide, silicon dioxide, kieselguhr, siliceous earth, quartz, silica gel, talc, kaolin, mica, perlite, feldspar, ground shale, calcium sulfate, barium sulfate, calcium carbonate, calcite, dolomite, glass or carbon. The fibers used may be organic and / or inorganic in nature and may likewise be used as reinforcing agents.

[0059] Examples of other solid particles include aluminum hydroxide or magnesium hydroxide, and flatting agents, such as silicas.

[0060] In a further embodiment, the invention relates to a composition comprising the polymer of the invention and solid particles dispersed in the composition.

[0061] The composition may be a paint, printing ink, other ink, for example inkjet ink, paper coating, leather and textile colour, paste, pigment concentrate, ceramic and cosmetic preparation.

[0062] The polymers of the invention are used preferably for producing pigment- and / or fillercomprising pigment concentrates, paints, pastes and / or moulding compositions.

[0063] In some embodiments, the composition further comprises a polymeric film-forming binder, which is different from the polymer of the invention. Examples of typical binders are resins based on polyurethanes, cellulose nitrates, cellulose acetobutyrates, alkyds, melamines, polyesters, chlorinated rubbers, epoxides and acrylates. Examples of water-based coatings are cathodic or anodic electrodeposition coatings for car bodies, for example. Further examples are renders, silicate paints, emulsion paints, aqueous paints based on waterdilutable alkyds, alkyd emulsions, hybrid systems, 2-component systems, polyurethane dispersions and acrylate dispersions.

[0064] The polymers of the invention are suitable for preparing concentrates of solids, such as pigment concentrates, for example. For that purpose, the polymers of the invention are optionally introduced in a carrier medium such as organic solvents, plasticizers and / or water, and the solids to be dispersed are added with stirring. Additionally, these concentrates may include binders and / or other auxiliaries. It is also possible using the polymers of the invention to prepare liquid concentrates of solids from pigment presscakes. In this case the polymer of the invention is admixed to the presscake, which may additionally contain organic solvents, plasticizers and / or water, and the resulting mixture is dispersed.

[0065] The polymers of the invention are very suitable for preparing pigment concentrates for tinting architectural paints, for example for tinting architectural white paints at points of sale or by an end-user to a desired color.

[0066] Very good results have been obtained with compositions comprising the polymer of the invention, solid particles dispersed in the composition, and comprising a further organic polymer.

[0067] In a typical embodiment, the composition comprises organic solvent and the organic polymer is an alkyd resin.

[0068] In an alternative embodiment, the composition comprises water and the organic polymer is present in the form of particles dispersed in the water.

[0069] Such compositions are very suitable as solvent-borne architectural paint or as water-borne architectural paint.

[0070] The polymers of the invention can also be used to produce cosmetic preparations such as, for example, makeup, powder, lipsticks, hair colorants, creams, nail varnishes and sun protection products. These may be present in the customary forms, as for example W / O or O / W emulsions, solutions, gels, creams, lotions or sprays. The polymers of the invention can be used with advantage in dispersions that are used for preparing these preparations. These dispersions may contain the carrier media that are typical for these purposes, such as, for example, water, castor oils or silicone oils, and solids, such as organic and inorganic pigments such as titanium dioxide or iron oxide, for example.

[0071] The polymers of the invention are added preferably in an amount of 0.01% to 10.00% by weight, based on the total formulation amount. Based on the solid to be dispersed, they are used in an amount of preferably 0.50% to 100.00% by weight. Where difficult-to-disperse solids are used, the amount of inventive polymer employed may well be higher. The amount of polymer is generally dependent on the surface that is to be coated of the substance that is to be dispersed. For example, if titanium dioxide is used as a pigment, the amount of dispersant is lower than in the case of, say, carbon black. Generally speaking, the amount of dispersant needed to disperse inorganic pigments is less than for organic pigments, since the latter have a higher specific surface area and, consequently, a greater amount of dispersant is needed. Typical addition levels for inorganic pigments are 1-10% by weight, for organic pigments 10-30% by weight (in each case expressed as polymer relative to pigment). In the case of very finely divided pigments (e.g. some carbon blacks), amounts of 30-80% by weight or more need to be added, even.

[0072] In a further aspect, the invention relates to a process of dispersing solid particles in a dispersion medium, comprising i) mixing a dispersion medium, solid particles, and the polymer according to the invention, and ii) subjecting the mixture to shear force.

[0073] Examples

[0074] Preparation of polymers

[0075] Example 1

[0076] 11.08 g of an aliphatic polyisocyanate (Desmodur® N 3300 ex Covestro) with an isocyanate content of 21 .7% NCO and an equivalent weight of 193.5 g / mol was mixed with 84.5 g of a butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 50:50) with a hydroxyl equivalent weight of 2450 g / mol, and 3.37 g of cashew nutshell liquid with a hydroxyl equivalent weight of 293.5 g / mol. The reaction mixture was heated to 70 °C under nitrogen with stirring. When 70 °C was reached, 0.03 g of a bismuth carboxylate (K- KAT-XK 651 ex King Industries) was added as a catalyst. The reaction mixture was given two hours to react. Then, 1.02 g of 2-dimethylaminoethanol was added. The reaction mixture was allowed to react for 30 minutes, then cooled to 50 °C and removed from the reaction vessel.

[0077] Example 2

[0078] Following the procedure described for Example 1 , Example 2 was produced by replacing the 3.37 g cashew nutshell liquid with 2.2 g of lauryl alcohol.

[0079] Example 3

[0080] Following the procedure described for Example 1 , Example 3 was produced by replacing 1.02 g of 2-dimethylaminoethanol with 1.17 g of dimethylaminopropylamine. The resulting viscosity was considerably higher than Example 1.

[0081] Example 4

[0082] 99.4 g of the polymer produced in Example 1 was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel. Example 5

[0083] 98.3 g of the polymer produced in Example 1 was added to a reaction vessel and heated to 50 °C. 1.67 g of an aliphatic carboxylic acid with an acid value of 389 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0084] Example 6

[0085] 99.4 g of the polymer produced in Example 2 was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0086] Example 7

[0087] Following the procedure described for Example 1 , a polymer was produced by replacing the

[0088] 3.37 g cashew nutshell liquid with 3.44 g of a partially hydrogenated cashew nutshell liquid with an average equivalent weight of 300.5 g / mol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0089] Example 8

[0090] Following the procedure described for Example 1 , a polymer was produced by replacing the

[0091] 3.37 g cashew nutshell liquid with 1.20 g of 1-hexanol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0092] Example 9

[0093] Following the procedure described for Example 1 , a polymer was produced by replacing the

[0094] 3.37 g cashew nutshell liquid with 1.52 g of 2-ethylhexanol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0095] Example 10

[0096] Following the procedure described for Example 1 , a polymer was produced by replacing the

[0097] 3.37 g cashew nutshell liquid with 1.52 g of 1-octanol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of a phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0098] Example 11

[0099] Following the procedure described for Example 1 , a polymer was produced by replacing the 3.37 g cashew nutshell liquid with 3.58 g of a fully hydrogenated cashew nut liquid with a hydroxyl equivalent weight of 313.6 g / mol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of a phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0100] Example 12

[0101] Following the procedure described for Example 1 , a polymer was produced by replacing the 84.5 g of the butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 50:50) with a hydroxyl equivalent weight of 2450 g / mol with 84.75 g of a butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 70:30) with a hydroxyl equivalent weight of 2493 g / mol. 99.4 g of the polymer was added to a reaction vessel and heated to 50 °C. 0.6 g of a phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0102] Comparative Example C1

[0103] 80.0 g of an aromatic polyisocyanate in ethyl acetate (Desmodur® ultra IL EA ex Covestro) with an isocyanate content of 8% was combined with 224.96 g of a butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 50:50) with a hydroxyl equivalent weight of 2450 g / mol, and 8.97 g of cashew nutshell liquid with a hydroxyl equivalent weight of 293.5 g / mol. The reaction mixture was heated to 50 °C under nitrogen with stirring. The initial solution had a turbid appearance and gel-like consistency. Heating was continued and 0.01 g of K-KAT-XK 651 was added as a catalyst. The viscosity decreased, but a white precipitate formed in the reaction vessel. 2.72 g of 2- dimethylaminoethanol was added. The amine did not react completely, and unreacted isocyanate groups were detected in the precipitate. The reaction mixture was disposed of due to unreacted isocyanate.

[0104] Comparative Example C2 Following the procedure described for Comparative Example 1 , a polymer was produced by omitting the 3.37 g of cashew nutshell liquid with a hydroxyl equivalent weight of 293.5 g / mol and instead increasing the 84.5 g of a butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 50:50) with a hydroxyl equivalent weight of 2450 g / mol to 113.2 g of the same butanol-initiated polyether.

[0105] Comparative Example C3

[0106] 99.4 g of the polymer produced in Comparative Example C2 was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0107] Comparative Example C4

[0108] 98.7 g of the polymer produced in Comparative Example C2 was added to a reaction vessel and heated to 50 °C. 1.3 g of an aliphatic carboxylic acid with an acid value of 389 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0109] Comparative Example C5

[0110] 11.08 g of an aliphatic polyisocyanate (Desmodur® N 3300 ex Covestro) with an isocyanate content of 21.7% NCO and an equivalent weight of 193.5 g / mol was mixed with 89.0 g of a methanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 70:30) with a hydroxyl equivalent weight of 1934.5 g / mol. The reaction mixture was heated to 70 °C under nitrogen with stirring. When 70 °C was reached, 0.03 g of a bismuth carboxylate (K-KAT-XK 651 ex King Industries) was added as a catalyst. The reaction mixture was given two hours to react. Then, 1.02 g of 2-dimethylaminoethanol was added. The reaction mixture was allowed to react for 30 minutes, then cooled to 50 °C and removed from the reaction vessel.

[0111] Comparative Example C6

[0112] 99.4 g of the polymer produced in Comparative Example C5 was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0113] Comparative Example C7 98.4 g of the polymer produced in Comparative Example C5 was added to a reaction vessel and heated to 50 °C. 1.6 g of an aliphatic carboxylic acid with an acid value of 389 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0114] Comparative Example C8

[0115] 11.08 g of an aliphatic polyisocyanate (Desmodur® N 3300 ex Covestro) with an isocyanate content of 21.7% NCO and an equivalent weight of 193.5 g / mol was mixed with 113.3 g of a butanol-initiated polyether prepared from ethylene oxide and propylene oxide (weight ratio 50:50) with a hydroxyl equivalent weight of 2450 g / mol. The reaction mixture was heated to 70 °C under nitrogen with stirring. When 70 °C was reached, 0.03 g of a bismuth carboxylate (K-KAT-XK 651 ex King Industries) was added as a catalyst. The reaction mixture was given two hours to react. Then, 1.4 g of 1H-lmidazole-1-propanamine was added. The reaction mixture was allowed to react for 30 minutes, then cooled to 50 °C and removed from the reaction vessel.

[0116] Comparative Example C9

[0117] 99.4 g of the polymer produced in Comparative Example C8 was added to a reaction vessel and heated to 50 °C. 0.6 g of an aliphatic phosphate ester with an acid value of 600 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0118] Comparative Example C10

[0119] 98.6 g of the polymer produced in Comparative Example C8 was added to a reaction vessel and heated to 50 °C. 1.4 g of an aliphatic carboxylic acid with an acid value of 389 mg / g KOH was added and mixed for 30 minutes and the resulting product was removed from the reaction vessel.

[0120] Application tests of polymers in pigmented compositions

[0121] Preparation of pigment concentrates

[0122] Pigment Yellow 4 Concentrate, using a yellow iron oxide pigment

[0123] 31.13 g of deionized water, 0.10 g of a preservative, 0.49 g of BYK-094, and 0.10 g of Optigel WX were added to a Flacktek Max 100 long cup with screw top lid and hand mixed with a metal spatula. 11.36 g of a polymer as prepared above and specified in Table 1 below was added and hand mixed with a metal spatula. 56.82 g of Pigment Yellow 4 was added to the jar followed by 100 g of 0.8-1mm of glass beads. The lid of the jar was tightened, and Teflon tape was used to ensure a complete seal. The sample jar was then placed in a Flacktek Speedmixer at 1400 RPM for 7 minutes. Once the mixing was completed the pigment concentrate was filtered through a 4000 pm filter to remove the glass beads. Pigment Blue 5 Concentrate, using a phthalo blue pigment

[0124] 51.41 g of deionized water, 0.11 g of a preservative, and 0.49 g of BYK-017 were added to a Flacktek Max 100 long cup with screw top lid and hand mixed with a metal spatula. 0.16 g of a polymer as prepared above and specified in Table 1 was added and hand mixed with a metal spatula. 16.0 g of Pigment Blue 5 followed by 32.0 g of barium sulfate was added to the jar followed by 100 g of 0.8-1mm of glass beads. The lid of the jar was tightened, and Teflon tape was used to ensure a complete seal. The sample jar was then placed in a Flacktek Speedmixer at 1400 RPM for 7 minutes. Once the mixing was completed the pigment concentrate was filtered through a 4000 pm filter to remove the glass beads.

[0125] Table 1: Overview of pigment concentrates prepared

[0126] Comparative pigment concentrates are marked by

[0127] Preparation of inorganic yellow pigmented coating compositions

[0128] One 1.0 g of a pigment concentrate as indicated in Table 2 below was mixed into 40 g of a commercial alkyd-based solvent-borne white paint and was shaken for 3 minutes using a Chameleon paint shaker.

[0129] One 1.0 g of a pigment concentrate as indicated in Table 3 below was mixed into 40 g of a commercial acrylic latex-based water-borne white paint and was shaken for 3 minutes using a Chameleon paint shaker.

[0130] Table 2: Overview of solvent-borne yellow pigmented coating compositions

[0131] Table 3: Overview of water-borne yellow pigmented coating compositions

[0132] Preparation of organic blue pigmented coating compositions

[0133] One 1.0 g of a pigment concentrate as indicated in Table 4 below was mixed into 40 g of a commercial alkyd-based solvent-borne white paint and was shaken for 3 minutes using a Chameleon paint shaker.

[0134] One 1.0 g of a pigment concentrate as indicated in Table 5 below was mixed into 40 g of a commercial acrylic latex-based water-borne white paint and was shaken for 3 minutes using a Chameleon paint shaker.

[0135] Table 4: Overview of solvent-borne blue pigmented coating compositions

[0136] Table 5: Overview of water-borne blue pigmented coating compositions

[0137] Evaluation of pigmented coating compositions Test Methods:

[0138] Tint Paint

[0139] A white base (either solvent-based or water-based) was tinted with the created pigment concentrates shown above by adding 1g of pigment concentrate to 40g base paint, then shaking on a Chameleon Paint Shaker for 3-6 minutes. Tint Strength

[0140] Tint strength was determined using a BYK-Gardner Spectro-guide sphere with the index set to StrMaxAbs to measure color strength compared to a selected sample at a determined wavelength of light (selected by software and Control sample). The comparative examples were used as the control samples. Over 100% indicates stronger color strength and under 100% indicated weaker color strength.

[0141] Flooding / Floating Color Stability

[0142] Tinted paint was drawn down onto a BYKO chart using a 6-mil wet-film-thickness draw-down bar. The paint was allowed to sit until it began to become tacky (20 mins for solvent-based paint and 3-5 minutes for water-based paint in this testing). Once the paint became tacky, a finger was passed over the paint’s surface to purposefully disturb it. The sample was allowed to dry overnight before measuring. The same was measured using a BYK-Gardner Spectro-guide sphere, with the index set to AE* and the color system set to Cl ELab. The portion of the card that was not rubbed was considered the standard. The standard and then the sample (disturbed side) were measured. The calculated total change (Rub out, AE) is determined based on the color measurements of the standard and the sample. A value less than 1.0 is preferable and a value less than 0.5 is even more preferable.

[0143] Table 6: Properties of solvent-borne yellow pigmented coating compositions Table 7: Properties of water-borne yellow pigmented coating compositions

[0144] Table 8: Properties of solvent-borne blue pigmented coating compositions

[0145] Table 9: Properties of water-borne blue pigmented coating compositions

[0146] The preceding examples demonstrate an overall improvement in dispersal of both organic and inorganic pigments. This is evidenced by equaling or improving on the tint strength and / or rub out (A E) of currently available dispersing agents regardless of whether the composition is a water borne composition or a solvent borne composition. This is a marked advantage over current systems in which a different dispersing agent can be required depending on the nature of the pigment (organic or inorganic) and / or the nature of the base composition (water borne or solvent borne) in order to achieve adequate performance. None of the comparative polymers, especially without the pendant groups comprising hydrocarbyl groups having 6 to 40 carbon atoms (i.e. structural unit b) i)), can be universally used with organic and inorganic pigments in both water-borne and solvent-borne compositions: for example, the polymer of comparative example C5 provides good results when used with inorganic particles, however when used with organic particles inferior properties result and these respective coating compositions are not usable.

Claims

Claims1) A polymer comprising a) a core comprising at least one of urethane or isocyanurate groups based on a linear aliphatic diisocyanate, and b) an average of 2.6 to 6.0 pendant groups covalently linked to the core via a linking group comprising at least one of a urethane group and a urea group, wherein the pendant groups comprise i) hydrocarbyl groups having 6 to 40 carbon atoms, ii) hydrocarbyl terminated polyether groups, and iii) at least one of tertiary amine groups and salts of tertiary amine groups.2) The polymer according to claim 1, wherein the linear aliphatic diisocyanate is hexamethylene diisocyanate.3) The polymer according to any one of the preceding claims, wherein the hydrocarbyl groups have 8 to 40 carbon atoms and comprise an aryl group or a cycloaliphatic group and a non-cyclic aliphatic group.4) The polymer according to claim 3, wherein the non-cyclic aliphatic group is a linear or branched aliphatic group, optionally comprising at least one olefi nically unsaturated group.5) The polymer according to any one of the preceding claims, wherein the hydrocarbyl groups have 6 to 40 carbon atoms comprise linear aliphatic groups.6) The polymer according to any one of the preceding claims, wherein the hydrocarbyl terminated polyether groups comprise polymerized units of at least one of ethylene oxide and propylene oxide.7) The polymer according to any one of the preceding claims, wherein the polyether groups are terminated by hydrocarbyl groups having 1 to 4 carbon atoms.8) The polymer according to any one of the preceding claims, wherein the pendant groups comprise salts of tertiary amine groups.9) Use of the polymer according to any one of the preceding claims as a dispersant for solid particles.10) The use according to claim 9, wherein the solid particles comprise at least one of filler particles and pigment particles.11) A composition comprising the polymer according to any one of the preceding claims 1 to 8, and solid particles dispersed in the composition. 12) The composition according to claim 11, wherein the composition comprises a further organic polymer which is different from the polymer according to preceding claims 1 to 8.13) The composition according to claim 12, wherein the composition comprises an organic solvent and wherein the organic polymer is an alkyd resin. 14) The composition according to claim 12, wherein the composition comprises water and wherein the organic polymer is present in the form of particles dispersed in the water.15) A process of dispersing solid particles in a dispersion medium, comprising i) mixing a dispersion medium, solid particles, and the polymer according to any one of the preceding claims 1 to 8, and ii) subjecting the mixture to shear force.

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