EP2091983A1

EP2091983A1 - Amphiphilic graft polymers

Info

Publication number: EP2091983A1
Application number: EP07819174A
Authority: EP
Inventors: Matthias Schrod
Original assignee: Sued Chemie AG
Current assignee: Sued Chemie AG
Priority date: 2006-10-19
Filing date: 2007-10-19
Publication date: 2009-08-26
Also published as: DE102006049381A1; JP2010506984A; WO2008046652A1

Abstract

The invention relates to a graft polymer obtainable for copolymerizing: at least one macromonomer of the formula (I) in which: X is a divalent branched or unbranched alkylene radical having from 1 to 12 carbon atoms; R1, R2, R3 are each independently a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms; R4, R5 are each independently a hydrogen atom or a methyl group; R6 is hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, a sulfate group, a phosphate group or a monoester of a dicarboxylic acid, and salts thereof; n is from 5 to 500; and at least one further monomer which has a polymerizable ethylenically unsaturated double bond.

Description

AMPHIPHILE PFROPP POLYMERS

The invention relates to graft polymers, a process for the preparation of these graft polymers, and their use as dispersants.

When solids are dispersed in liquid media, for example in the production of paints and varnishes, the solids are divided into fine primary particles which are wetted by the liquid dispersion medium. If possible, the fine primary particles should be evenly distributed in the dispersion medium so that a homogeneous dispersion is obtained. After dispersing, the dispersion should remain stable, ie the fine primary particles should not agglomerate again into larger aggregates, which then sink, so that the dispersion separates again. As a result of incomplete dispersion, agglomerates remain in the dispersion or flocculation of the primary particles occurs, leading to undesirable effects, such as an increase in viscosity in liquid systems, color drift and gloss loss in paints and coatings and reduction of mechanical properties Strength of plastics. In order to keep the energy required for dispersing and the time required as low as possible, dispersants are used. Dispersants are surface-active compounds which can mediate between the surface of the solid and the dispersion medium and thus make it possible to break up the pigment agglomerates into primary particles. Dispersing medium and solid usually have a different polarity, so that the surface of the solid is not readily wetted by the dispersing medium. Dispersants are usually polymeric compounds comprising portions of different polarity. Thus, one portion of the dispersant may preferentially interact with the surface of the solid and another with the dispersing medium. To obtain regions of different polarity, the dispersants may comprise anionic, cationic or neutral charge portions. As a further effect, the dispersants cause reagglomeration of the dispersed primary particles by steric hindrance or repulsion between equally charged groups.

In particular in the production of pigment concentrates, the highest possible degree of pigmentation or a small proportion of binder or solvent should be realized. However, with sufficient stabilization of pigments or solids in the dispersing medium, many dispersants show insufficient ability to lower the viscosity of the dispersion. This particularly causes difficulties when water is used as a dispersing medium. When dispersed in water, the viscosity of the material to be ground can rise sharply, so that more dispersant, solvent or co-solvent must be added in order to be able to process the dispersion further. As a result, however, the proportion of the pigment or solid in the dispersion decreases. For reasons of environmental protection, it is endeavored to keep the proportion of organic solvents as low as possible or to use only water as the dispersing medium. Next is one strives, for cost reasons, to minimize the number of additives added to the dispersions. Defoamers must usually be added to the dispersions in order to suppress foaming during dispersion. Although many additives improve certain properties of a dispersion. At the same time, however, a deterioration of other properties often has to be accepted. The problem is, for example, the moisture sensitivity or water resistance, which increases or decreases when using hydrophilic additives. Also dispersants usually comprise hydrophilic sections, so that their addition to, for example, a paint deteriorates its resistance to moisture.

In addition to the requirement not to impair the water resistance of a paint film produced, for example, from the dispersion, if possible, the dispersants should also improve other colorimetric properties, such as color strength and gloss of a color coat.

EP 1 081 169 A1 describes branched polymers bearing imidazole groups which are obtained by free-radical polymerization from a monomer mixture comprising from 50 to 93% by weight of at least one ethylenically unsaturated monomer, from 2 to 25% by weight of at least one ethylenically unsaturated one Macro-monomers having a molecular weight of 1,000 to 20,000 g / mol and 5 to 25 wt .-% of at least one polymerizable imidazole derivative, wherein the components to 100 wt .-% complementary. The ethylenically unsaturated macromonomer forms the side chains to the polymer backbone. The ethylenically unsaturated monomer used is preferably acrylates and / or methacrylates of straight-chain or branched alcohols having 1 to 22 carbon atoms. Other suitable ethylenically unsaturated comonomers are, for example, styrene, α-methylstyrene, triethylene glycol mono (meth) acrylate, acrylonitrile, methoxy - -

polyethylene glycol (meth) acrylate, butoxypropylene glycol (meth) acrylate, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether. As the imidazole group-containing monomer, vinylimidazole is preferably used. The macromonomers are prepared, for example, by polymerization of meth (acrylic) acid esters of straight-chain or branched alcohols having 1 to 22 carbon atoms, the polymerization being carried out in such a way that a single terminal (meth) acryl function is retained. Other suitable macromonomers are, for example, mono-vinyl-terminated polydimethylsiloxanes, which are e.g. by reaction of monohydroxy-functional polysiloxanes with meth (acrylic) acid. The polymers can be used, for example, as dispersants in the production of paints, pastes and / or molding compositions containing pigments and / or fillers.

EP 1 197 536 A2 describes a graft polymer which is suitable as a dispersant in aqueous systems. The polymer backbone is hydrophobic compared to the side chains and is formed from hydrophobic monomeric (meth) acrylic acid derivatives to form up to 30% by weight of the polymer backbone of monomers bearing functional groups which enhance the bonding of the polymer to a pigment surface. The polymer backbone carries hydrophilic side chains which either carry anionic groups or are neutral. The anionic side chains are formed from anionic hydrophilic macromonomers obtained by polymerization of (meth) acrylic acid derivatives, the macromonomers comprising from 2 to 100% by weight of polymerized acid group-carrying monomers. The nonionic side chains are formed from hydrophilic poly (alkylene glycol) (meth) acrylic macromonomers which carry a terminal (meth) acrylic acid group which is copolymerized into the backbone of the graft polymer. As the polyalkylene glycol, polyethylene glycol or polypropylene glycol is preferably used. - -

WO 01/10918 describes dispersants for paints whose side chains carry a terminal phosphate group. The dispersants are prepared by copolymerization of ethylenically unsaturated monomers bearing a phosphate group. The ethylenically unsaturated polymer carrying phosphate groups is derived from (meth) acrylic acid esterified with a polyalkylene oxide, wherein the terminal hydroxy group may be esterified with a phosphate group or a terminal epoxy group is provided. The monomer has a structure of the general formula:

CH ₂ = C (R ¹ ) C (O) OX _α (C ₂ H ₄ O) _p - (C ₃ H ₄ O) _γ -R II

where α can be 0 or 1, where furthermore if α = 1 X stands for a bivalent alkyl, aryl or arylalkyl group, B and Y are each independently a number between 0 and 100, without β and Y simultaneously being the value 0 R ^{1 is} a hydrogen atom or a methyl group and R ^{11 is} selected from a PO ₃ H ₂ group, a hydroxy group and an epoxy group.

EP 1 348 724 A1 describes a polymer suitable as a dispersant obtained by polymerizing (A) an unsaturated monomer bearing a sulfone group, (B) a nonionic unsaturated monomer comprising a polyoxyalkylene chain, (C) a monomeric one (Meth) - acrylic acid ester having two tertiary alkyl groups per molecule (CI) or a monomeric (meth) acrylic acid ester having a tertiary alkyl group and a secondary hydroxy group per molecule, and (D) further ethylenically unsaturated monomers. Suitable monomers (B) have a structure of the following formula:

CH ₂ = C (R ¹¹¹ ) COO (C ₅ H ₂₅ O) _ε -R ^IV Wherein R ^{111 is} hydrogen or a methyl group, R ^{IV is} hydrogen or an alkyl group having 1 to 4 carbon atoms, ε can be an integer between 6 and 50 and δ can be 2 or 3, where for the oxyalkylene _units (C _δ H _2δ O) the number ε can be the same or different.

EP 0 311 157 A1 describes a polymer which can be used as a dispersant and which is obtained by polymerization of (a) 0-80 mol% of styrene which may be substituted by alkyl groups, (b) 0-70 mol -% of a (meth) acrylic acid esterified with a long-chain alcohol, wherein the alkyl chain of the alcohol may also be interrupted by oxygen atoms, (c) 5 to 50 mol% of at least one monomer containing at least one heterocyclic group with at least a basic nitrogen atom, (d) 0-10 mol% of a monomer comprising a crosslinkable group and 0 to 20 mol% of other monomers.

No. 5,231,134 describes a process for the preparation of an amine group-modified polymer which can be used as a dispersant for pigments. The polymer is prepared by polymerizing an ethylenically unsaturated monomer bearing an isocyanate group together with other monomers which do not bear groups capable of reacting with the isocyanate group. The isocyanate groups are reacted during or after the polymerization with a compound selected from the group consisting of polyalkylene glycol monoalkyl ethers and polyalkylene glycol monoalkyl ethers bearing a terminal amino group, and with a compound having at least one tertiary amino group and a functional group, which can react with the isocyanate group, and optionally with another compound which has a functional group which can react with the isocyanate group. EP 0 661 357 A2 describes a dispersant for pigments, which is obtained by reaction

(a) a functionalized copolymer obtained by polymerization

(i) an ethylenically unsaturated monomer bearing as a functional group an isocyanate group, an anhydride group or an epoxy group;

(ii) at least one ethylenically unsaturated monomer bearing no functional group capable of reacting with the functional group of the monomer (i);

(b) at least one compound selected from the group of polyalkylene glycol homopolymers, copolymers and mixtures thereof; and

(c) a compound having a group which can interact with the pigment surface and which is selected from the group of

(i) hydrazides which may be substituted with aliphatic, aromatic and substituted aromatic groups,

(ii) imines of the formula

Wherein R ^v is OH or NHR ¹ , and R ^'is hydrogen, an alkyl or an aryl group, and R ^VI and R ^{VI1 may be the} same or different and represent a functional group selected from the group of aliphatic, aromatic or condensed aromatic groups, a benzoyl or alkanoyl group, these groups being replaced by an alkyl, an alkoxy or a hydroxy group or may be substituted by a halogen atom.

EP 0 826 751 A2 describes a graft polymer which can be used as a dispersant in aqueous dispersing media. The graft polymer is constructed so that either the polymer backbone or side chains are hydrophilic and the other chains are hydrophobic. Both the polymer backbone and the side chains are obtained by polymerization of ethylenically unsaturated monomers. The hydrophobic part is prepared from ethylenically unsaturated monomers, wherein based on the hydrophobic portion of the graft polymer, at least 50% by weight is derived from a monomer selected from the group consisting of aromatic esters and amides of (meth) acrylic acid as well as vinylaryl esters. In the case of anionic polymers, the hydrophilic part of the graft polymer is formed from monomers which have an optionally protected acid group. Suitable monomers are (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid. Suitable protected monomers are trimethylsilyl (meth) acrylate, 1-butoxyethyl (meth) acrylate, 1-ethoxy (meth) acrylate, and 2-tetrahydropyranyl (meth) acrylate. For cationic graft polymers, the cationic portion may be derived from monomers comprising an amino group. Suitable monomers are N, N-dimethylaminoethyl (meth) acrylate, 4-amino-styrene, or 2-vinylpyridine. The nonionic hydrophilic monomers have a structure of the formula

CH ₂ = C (R ^VI11 ) (C (O) OX _ζ (CH ₂ CH ₂ O) _n ) -R IX in which ζ is 0 or 1, wherein when ζ = 1 X is a divalent alkyl, aryl or aralkyl group, η is selected between 1 and 100, R ^{VI11 is} hydrogen or a methyl group and R ^{IX is} selected from the group of Hydrogen and alkyl groups having 1 to 4 carbon atoms.

WO 99/66004 describes a dispersant which is obtained by copolymerization of hydrophobic monomers which are selected from the group of (meth) acrylamides and (meth) acrylates, and hydrophilic monomers which are selected from the group of (meth) acrylamidosulfonic acids, (meth) acrylamididisulfonic acids and styrenesulfonic acids.

EP 1 197 536 A2 describes a graft polymer which can be used as a dispersant in aqueous systems. The graft polymer comprises a hydrophobic polymer backbone to which anionic or nonionic hydrophilic side chains are attached. The nonionic side chains are introduced into the graft polymer by copolymerizing a polyalkylene glycol terminated with a (meth) acrylic acid into the polymer backbone.

DE 10 2004 005 434 A1 describes a copolymer based on unsaturated mono- or dicarboxylic acid derivatives and oxyalkylene glycol alkenyl ethers which is suitable as an additive for aqueous suspensions based on mineral or bituminous binders, such as concrete mixtures. The copolymers contain at least 3, but preferably at least 4 components (a), (b), (c) and (d). The first group (a), which is contained in a proportion of 25 to 98.99 mol%, represents a mono- or dicarboxylic acid derivative having the general formula Ia, Ib or Ic.

Ib Ib

In the monocarboxylic acid derivative Ia, R ^{x is} hydrogen or an aliphatic hydrocarbon radical having 1 to 20 carbon atoms. In the formulas Ia and Ib, X represents -0M _θ and / or -O- _(C? H ₂ O) -R _K ^XI or -NH- (C ₁ H ₂₁ O) KR * ^1, where M is hydrogen or a monovalent or divalent metal cation, ammonium or an organic amine radical and θ = 0.5 or 1, depending on whether M is a monovalent or divalent metal cation. R ^XI is hydrogen, an aliphatic hydrocarbon radical having 1 to 20 carbon atoms, a cycloaliphatic or an aromatic radical and L = 2 and K = 0 to 200.

The second assembly, which is contained in a proportion of 1 to 48.9 mol%, corresponds to the formula II:

II

and is derived from oxyalkenylglycol-alkenyl ethers, where ι 'is 2 to 4, K' + K "is 250 to 500 and λ is 0 to 3 and R -, XI or ι have the meanings indicated above or an aliphatic hydrocarbon having 1 to 5 carbon atoms. _ _

The most simple and lightest building block of the oxyalkenyl glycol chain, it has a molecular weight of at least 11,000 g / mol.

The third component (c), which is contained in a proportion of 0.01 to 6 mol%, corresponds to the formula IHa or IHb

IHa IHb

wherein R ^{XI11 is} hydrogen or a methyl group, Q is -H, -COOM ₉ or -COOR ^XIV , wherein R ^{XIV is} an aliphatic or aromatic hydrocarbon radical and M and θ have the meaning described above. If T = -COOR ^XIV , Q stands for -COOM ₆ or -COOR ^XIV . T can also have the following structure:

where μ can take a value of 1 to 150 and v of 0 to 15. U ¹ can mean -CO-NH-, -O- or -OCH ₂ -.

T can furthermore be (CH ₂ ) _ω -V- (CH ₂ ) _ω -CH = CH-R ^XI , where ω can be 0 to 4 and V is a radical -O-CO-C ₆ H ₆ -CO-O - is.

The fourth component (d), which is contained in a proportion of 0 to 60 mol%, is derived from an unsaturated dicarboxylic acid derivative of the formula IVa and / or IVb: HHHH

-c c -C C

I I I I

COONL COX

IVa IVb

EP 1 069 139 A1 describes an aqueous polymer dispersion which is obtained by polymerization of an olefinically unsaturated, water-insoluble compound in the presence of a water-soluble allyl or vinyl ether of the formula

worxn

o is 0 or 1 π 0 or 1 is an integer from 1 to 20

AC ₂ - C ₄ - alkylene is an integer from 5 to 900, and R ^XVI : H or Ci - C ₄ - alkyl

mean. The macromonomers of the above formula can be used as emulsifiers or dispersants (dispersants) for emulsion polymerization or suspension polymerization. The macromonomer is given in very small amounts to the emulsion of water-insoluble monomers. The amounts of macromonomer used in the examples are in the range of about 0.1 mol%. The addition of the macromonomers stabilizes the droplets formed from monomers. Because of their hydrophilic polyglycol chain, the macromonomers in the first place at the interface of monomer droplets and water phase, so that the macromonomers are not homogeneously incorporated into the polymer. Their share in the polymer is therefore very low, so that after the collapse of the latex the properties of the polymer are no longer significantly influenced by the polymerized macromonomers. The individual droplets in the emulsion each form a kind of microreactor, within which the polymerization of the monomers takes place. Therefore, in each droplet, there is almost only one polymer each having a correspondingly high molecular weight. The high molecular weight of the polymer leads to high viscosities in solutions and dispersions. The polymers described in EP 1 069 139 A1 are therefore not suitable as dispersants, for example for paints and varnishes.

The object of the invention was first to provide a graft copolymer which can be used as a dispersant, it being possible to produce pigment concentrates using the graft copolymer which have a high pigment concentration and a low viscosity, ie are good process, have a high color strength and a high gloss in a paint binder and form a stable dispersion over a longer period of time.

This object is achieved with a graft copolymer having the features of patent claim 1. Advantageous embodiments of the graft copolymer are the subject of the dependent claims.

The invention therefore provides a graft polymer obtainable by copolymerization of:

at least one macromonomer of the formula 1 _ _

formula 1

in which means:

X: a divalent branched or unbranched alkylene radical having 1 to 12 carbon atoms;

R ¹ , R ² , R ³ : each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;

R ⁴ , R ⁵ : each independently, a hydrogen atom or a methyl group;

R ⁶ : a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a sulfate group, a phosphate group or a monoester of a dicarboxylic acid, and their salts;

n: 5 to 500;

and at least one other monomer having a polymerizable ethylenically unsaturated double bond.

The reactivity of the vinyl group of the macromonomer of formula 1 is relatively low because of its molecular size and the associated steric hindrance. In itself, it was therefore to be expected that the reactivity of the macromonomer of the formula 1 is too low compared to the other monomers to a greater extent in the polymer chain to be polymerized. Surprisingly, however, it has now been found that the vinyl group of the macromonomer of formula 1 has a sufficient reactivity to be copolymerized to an extent in a polymer chain formed from the other monomers, that a dispersant is obtained. In the preparation of the graft copolymer, the reaction is controlled so that the graft copolymer does not receive too high a molar mass and thus remains sufficiently small in order to be able to act as a dispersant for solid particles, for example pigment particles. The average molecular weight of the graft polymers of the invention, determined according to DIN 55 672-1 by size exclusion chromatography over polystyrene standards, is preferably 5,000 to 200,000 g / mol, preferably 7,500 to 100,000 g / mol, particularly preferably 10,000 to 75,000 g / mol.

The pendant polyalkylene glycol chains cause compatibility of the graft copolymer with polar, in particular aqueous, solvents but also with various paint binders. Polyethylene glycol chains and / or polypropylene glycol chains are particularly preferably used. It can be used for all side chains the same polyalkylene glycol. However, it is also possible to provide different polyalkylene glycol chains in the molecule. It is also possible that the polyalkylene glycol chain is made up of different glycols, for example a mixed polyethylene / polypropylene glycol. The polyalkylene glycol chains have an average chain length n of from 5 to 500, preferably from 10 to 150, in particular from 20 to 50.

The vinyl group of the macromonomer of the formula 1 may be substituted by short-chain alkyl radicals, but preferably an unsubstituted vinyl radical is used, ie R ¹ = R ² = R ³ = H, in order to achieve sufficient reactivity of the macromonomer in the polymerization. The vinyl group is connected via a divalent branched or unbranched radical X with the polyalkylene glycol chains having 1 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Preferably, the radical X is an unbranched alkylene group. More preferably, X is an n-butylene group.

The free end of the polyalkylene glycol chain may carry a hydroxy group. However, the hydroxy group may also be modified to affect, for example, the dispersing properties of the graft polymer. For this purpose, the OH group can be esterified, for example, with a diacid, for example, to introduce ionic groups into the graft copolymer. For the esterification, both inorganic and organic polyacids are suitable. Suitable inorganic acids are, for example, phosphoric acid or sulfuric acid, so that the polyalkylene glycol chains terminally carry a phosphate or sulfate group. Suitable organic acids are in particular dicarboxylic acids having 2 to 10 carbon atoms. Examples of suitable dicarboxylic acids are succinic acid, malonic acid or maleic acid, which can be elegantly introduced into the graft copolymer, for example via their anhydride as monoester. The ionic groups may be present both in the protonated acid form and as a salt, for example as an alkali metal salt, such as a sodium or potassium salt. Likewise, the ionic groups may be in the form of ammonium salts, for example as a tetraalkylammonium salt, such as a tetraethylammonium salt.

The graft copolymer according to the invention is obtained by polymerizing the macromonomer of the formula 1 with at least one further ethylenically unsaturated polymerizable monomer. The at least one further ethylenically unsaturated monomer forms the backbone of the graft copolymer, from which the polyalkylene glycol chains protrude like a comb. By selecting the other polymers, the inventive _ _

Graft copolymer to the polarity of the surface of the dispersing solid, in particular pigment, are tuned.

The selection of the other monomers is initially not subject to any particular limitations. The at least one other monomer may carry aromatic or aliphatic groups and may have an acidic, basic or neutral character. Only one more monomer can be used. But it is also possible to use several other monomers. For example, groups may be introduced into the polymer backbone in this manner which facilitate the attachment of the graft copolymer to the surface of the solid particle.

As the at least one further monomer, it is possible to use low molecular weight compounds which preferably have one or two polymerizable carbon-carbon double bonds. But it is also possible to use a macromonomer as the at least one other monomer. These macromonomers have been prepared from low molecular weight compounds and preferably have at least one polymerizable carbon-carbon double bond. The at least one further monomer preferably has a molecular weight of at most 5,000 g / mol, more preferably of at most 4,000 g / mol and particularly preferably of at most 2,500 g / mol.

In particular, the further monomers preferably have a molecular weight which is substantially lower than the molecular weight of the macro-monomer of formula 1. The molar mass of the at least one further monomer is preferably at most 350 g / mol, more preferably less than 300 g / mol especially preferably in the range from 70 to 250 g / mol. If macromonomers are used as the at least one further monomer, these preferably have a molecular weight of more than 220 g / mol. _

The further monomers are preferably selected from the group of acrylic acid, methacrylic acid and the derivatives of these acids, in particular the esters and amides of these acids with straight-chain, branched and cycloaliphatic alkyl groups having 1 to 22 carbon atoms, styrene and styrene derivatives, and maleic anhydride.

According to one embodiment of the invention, at least 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol%, particularly preferably at least 80 mol% and according to a further embodiment at least 90 mol% of the further monomers are formed by monomers which can be attributed to acrylic acid or methacrylic acid. This preferred group of further monomers thus comprises acrylic acid, methacrylic acid and derivatives of acrylic acid and of methacrylic acid.

A preferred derivative of acrylic acid or methacrylic acid is selected from the group of alkyl esters, hydroxyalkyl esters and aminoalkyl esters of (meth) acrylic acid in which the alkyl group may each have from 1 to 22 carbon atoms and further the free hydroxy group of the hydroxyalkyl group or the free amino group the aminoalkyl group can also carry one or two alkyl groups having 1 to 4 carbon atoms or the hydroxy or amino group also reacted with a mono- or dicarboxylic acid to the ester or monoester of the dicarboxylic acid, or to the amide or imide of a mono- or dicarboxylic acid can be.

Suitable further monomers are, for example, alkyl (meth) acrylates of straight-chain, branched or cycloaliphatic alcohols having 1 to 22 carbon atoms, for example methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, t-butyl ( meth) acrylate, aryl (meth) acrylates, such as benzyl (meth) acrylate or phenyl (meth) - acrylate, wherein the aryl radicals may each be unsubstituted or substituted up to twice, for example 4-nitrophenyl methacrylate; Acrylic acid, methacrylic acid, maleic acid, their salts and reaction products of succinic anhydride with hydroxyalkyl (meth) acrylates, for example 2-hydroxyethyl methacrylate; Hydroxyalkyl (meth) acrylates of straight-chain, branched or cycloaliphatic diols having 2 to 36 carbon atoms, for example 3-hydroxypropyl methacrylate, 3,4-dihydroxybutylmono-methacrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl methacrylate, 2,5-dimethyl-1,6-hexanediol monomethacrylate; Mono (meth) acrylates of ethers, polyethylene glycols, polypropylene glycols or mixed polyethylene / polypropylene glycols having 5 to 80 carbon atoms, such as, for example, tetrahydrofurfuryl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, 1-butoxypropyl (meth) acrylate, Cyclohexyloxymethyl (meth) acrylate, methoxymethoxyethyl (meth) acrylate, benzyloxymethyl (meth) acrylate, furfuryl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, allyloxymethyl (meth) acrylate, 1-ethoxybutyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, poly (ethylene glycol) methyl ether (meth) acrylate, poly (propylene glycol) methyl ether (meth) acrylate; Caprolactone and / or valerolactone-modified hydroxyalkyl (meth) acrylates or alcohol-initiated caprolactone and / or valerolactone esters which have been reacted with maleic acid with a molar mass of 220 to 5,000 g / mol, where the hydroxy (meth) - acrylates are preferably derived from straight-chain, branched or cycloaliphatic diols having 2 to 8 carbon atoms; Aminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate, 2-trimethylammoniumethyl (meth) acrylate chloride and N, N-dimethylaminopropyl (meth) acrylate; (Meth) acrylates of halogenated alcohols, such as perfluoroalkyl (meth) acrylates having 6 to 20 carbon atoms; Oxiranyl (meth) acrylates such as 2, 3-epoxybutyl (meth) acrylate, 3, 4-epoxybutyl (meth) acrylate and glycidyl (meth) acrylate; styrene _

and substituted styrenes such as 4-methylstyrene, 4-vinylbenzoic acid and sodium 4-vinylbenzoate; (Meth) acrylonitrile; ethylenically unsaturated heterocycles such as 4-vinylpyridine and 1- [2- (methacryloyloxy) ethyl] -2-imidazolinone; Phosphoric acid-containing monomers such as tripropylene glycol methacrylate phosphate and ethylene glycol methacrylate phosphate; ethylenically unsaturated sulfonic acids and sulfates and salts thereof, such as potassium [3- (methacryloyloxy) propyl] sulfonate, ammonium [2- (methacryloyloxy) ethyl] sulfate; Vinyl esters of carboxylic acids having 1 to 20 carbon atoms, such as vinyl acetate; Maleimide, N-phenylmaleimide and N-substituted maleimides having straight, branched or cycloaliphatic alkyl groups of 1 to 22 carbon atoms, such as N-ethylmaleimide and N-octylmaleimide; (Meth) acrylamide and N-alkyl and N, N-dialkyl substituted (meth) acrylamides having straight-chain, branched or cycloaliphatic alkyl groups having 1 to 22 carbon atoms, such as N- (t-butyl) acrylamide and N, N-dimethylacrylamide; silyl-containing (meth) acrylates such as (meth) acrylic acid (trimethylsilyl ester) and methacrylic acid [3- (trimethylsilyl) propyl ester].

According to a further embodiment, the further monomers comprise a proportion of styrene and / or styrene derivatives of at least 2 mol%, preferably at least 4 mol%, particularly preferably at least 6 mol%. The proportion of styrene and / or styrene derivatives in the other monomers is, according to one embodiment, less than 30 mol%, preferably less than 20 mol%.

In order to achieve a sufficient dispersing effect, the proportion of the macromonomer of the formula 1 is preferably at least 1 mol%, more preferably at least 2 mol%, and according to a further embodiment, at least 3 mol% of the graft copolymer according to the invention. Preferably, the proportion of the macromonomer _ _

of formula 1 on the graft copolymer according to the invention between 1 and 20 mol%, more preferably 2 and 15 mol%, particularly preferably 3 and 10 mol% selected.

The proportion of free carboxylic acid groups in the backbone of the graft copolymer according to the invention is preferably 0 to 50 mol%, particularly preferably 5 to 40 mol%, particularly preferably 10 to 30 mol%. The percentages in this case relate to the monomer with which the free carboxylic acid groups are introduced into the backbone of the graft copolymer according to the invention and relate to the fraction of the other monomers. The presence of free carboxylic acid groups improves the adhesion of the graft copolymer of the invention to the surface of solid particles, in particular pigments. The carboxylic acid groups are preferably prepared via acrylic acid or methacrylic acid or via the above-mentioned reaction products of hydroxyalkyl (meth) acrylates and e.g. Succinic anhydride introduced into the backbone of the graft copolymer.

The invention further relates to a process for the preparation of a graft copolymer as described above. According to the invention, the above-described at least one macromonomer of formula 1 and the at least one further monomer are provided and the monomers are radically polymerized. For this purpose, for example, a solution of the above-described at least one macromonomer of formula 1 and of the at least one further monomer in a solvent can be prepared and the monomers can be radically polymerized in homogeneous solution. Furthermore, the polymerization in heterogeneous phase as emulsion or suspension polymerization is possible.

In order to be used as a dispersant, the molecular weight of the graft polymer of formula 1 according to the invention must not be too high. The polymerization is therefore preferably carried out in a suitable solvent in which the monomers _ -

can be solved. In the polymerization, the molecular weight of the graft copolymer is then held by chain termination reactions in the desired range. Suitable solvents are those whose boiling point is in the preferred range of the reaction temperature and which have no groups which can react with groups of the macromonomer of the formula 1 or the other monomers. The solvent is preferably selected in such a way that the reaction can be carried out at the boiling point of the solvent. Suitable solvents are e.g. Ketones, such as acetone, methyl ethyl ketone or methyl propyl ketone; Esters, such as butyl acetate and pentyl propionate; Ethers, such as diethyl ether, tert-butyl methyl ether, dioxane and tetrahydrofuran; N-methylpyrrolidone; keto ester; aromatic hydrocarbons, such as toluene or the xylenes; as well as mixtures of these solvents.

Conveniently, the reaction is carried out at temperatures in the range of 20 to 200 ^° C. The solvent or the solvent mixture is preferably first heated to the reaction temperature and then the monomer or the monomer mixture is added dropwise over a relatively long period of time. The period is suitably chosen so that a uniform reaction is achieved. The period depends on the size of the approach. It is preferably between 30 minutes and 6 hours.

The radical polymerization can be started in the usual way. For example, radicals can be generated by heating or by irradiation with light. Preferably, however, a conventional radical initiator is added to the monomer mixture. Suitable free-radical initiators are, for example, peroxides, such as dialkyl peroxides, peroxyesters, peroxydicarbonates, diacyl peroxides, hydroperoxides and peroxyketals, and azo compounds, such as 2,2'-azobis (2-methylbutanenitrile) and 1,1'-azobis (cyclohexanecarbonitrile). The radical starter exhibits at the temperature, at wel- - -

rather, the free-radical polymerization is carried out, preferably a half-life of about one to 30 minutes.

In order to adjust the molecular weight of the graft copolymer of the invention in the desired range, the reaction mixture is preferably added to a chain transfer agent. Suitable chain transfer agents are mercaptans, such as octyl mercaptan, n- or tert. Dodecyl mercaptan, halogenated compounds, thiosalicylic acid, mercaptoacetic acid, mercaptoethanol, butylene-ol and dimeric α-methylstyrene. Mercaptans are preferably used as chain transfer agents.

For workup, initially unreacted monomers are decomposed by addition of free radical initiator. Subsequently, the solvent is removed and optionally replaced by water.

Furthermore, the invention relates to a dispersion which contains at least one dispersing medium, a solid and the graft polymer according to the invention. It is particularly preferred to use as the solid a pigment to produce, for example, a paint or a lacquer.

The dispersion is prepared per se in the usual way, for example by milling a dispersion containing the dispersing medium, the solid and the graft polymer. A suitable dispersing medium is, for example, water. In addition to the components mentioned, the dispersion may also contain customary components for paints and coatings.

The invention will be explained in more detail with reference to examples. - -

Example 1 :

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 100 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 43.96 g of butyl acrylate, 22.91 g of methyl methacrylate, 24.4 g of butyl methacrylate, 14.77 g of methacrylic acid, 26.98 g of dimethylaminoethyl methacrylate, 116.97 g of vinylpolyethylene glycol having an average molecular weight of 2000 g / mol (VPEG 2000 Clariant GmbH, Frankfurt, DE), 1.16 g of dodecyl mercaptan and 9.39 g 2, 2 '-dimethyl- 2, 2' -azodipropiononitril (Peroxan ^® AZDN; Pergan Chemie, Bocholt, DE ) submitted in 70 g of toluene and added dropwise for about 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® AZDN reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 2:

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 300 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 42.10 g of butyl acrylate, 16.06 g of methyl methacrylate, 22.81 g of butyl methacrylate, 20.72 g of methacrylic acid, 37.83 g of dimethylaminoethyl methacrylate, 33.42 g of styrene, 328.06 g VPEG submitted in 2000, 1.62 g of dodecyl mercaptan and 13.17 Peroxan ^® AZDN in 170 g of toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers, if appropriate by addition of small amounts Peroxan ^® AZDN reacted until complete conversion is achieved. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 3

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 240 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 61.00 g of butyl acrylate, 39.73 g of methyl methacrylate, 41.33 g of styrene, 33.5 g of reaction product of hydroxyethyl methacrylate and phosphoric acid, 324.59 g of VPEG 2000, 34.33 g tert. Butyl peroxy-2-ethyl hexanoate (Peroxan ^® PO, Pergan Chemie) and 6.41 g of dibenzoyl peroxide (Peroxan ^® BP-25WD, Pergan Chemie) in 150 g of toluene and added dropwise over about 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® PO reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 4

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 35.92 g of butyl acrylate, 16.84 g of methyl methacrylate, 23.92 g of butyl methacrylate, 23.36 g of styrene, 35.27 g of dimethylaminoethyl methacrylate, 114.68 g of VPEG 2000, 0.92 g of dodecyl mercaptan and 18.42 g Peroxan ^® Submitted AZDN in 110 g of toluene and added dropwise for about 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® AZDN reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 5

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 17.9 g of butyl methacrylate, 12.6 g of methyl methacrylate, 26.2 g of styrene, 21.6 g of methacrylic acid, 171.6 g of VPEG 2000, 9.1 g of Peroxan ^® PO in 62.5 g of toluene submitted and added dropwise for about 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® PO reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 6

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 14.2 g of butyl acrylate, 11.1 g of methyl methacrylate, 23.0 g of styrene, 101.9 g _ -

Reaction product of succinic anhydride and 2-hydroxyethyl methacrylate (50% in toluene), 150.8 g VPEG 2000 20.7 g PO Peroxan ^®, 3.9 g Peroxan ^® BP-25 WD placed in 60 g of toluene, and during ca. 2 hours dripped. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® PO reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 7

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 30.54 g of methyl methacrylate, 31.77 g of styrene, 131.96 g of reaction product of hydroxyethylpyridine and α, α-dimethyl-meta-isoprenylbenzylisocyanat (TMI, Cytec Industries INC., West Paterson, NJ, USA, 50% in toluene), 8.75 g of methacrylic acid, 131.97 g VPEG 1100 (Clariant GmbH), 13.2 g Peroxan ^® PO presented in 62.5 g of toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® PO reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water. - o -

Example 8

Preparation of the polyester 1

In a round bottom flask with reflux condenser 333.9 g ε-caprolactone and 65.9 g decanol for about 30 minutes erhizt to 140 ⁰ C. Then dibutyltin oxide (Bu ₂ SnO, Fascat ^® 4201, Atofina Chemicals Inc., Philadelphia, PA, USA) is added and the temperature increased to 150 ⁰ C. For a solids greater than 98%, maleic anhydride is added and the reaction followed by determination of the acid number. At an acid number of less than 55 mg KOH / g, the reaction is stopped and the product is poured out.

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 33.30 g of butyl acrylate, 17.35 g of methyl methacrylate, 6.16 g of butyl methacrylate, 9.02 g of styrene, 99.73 g of reaction product of succinic anhydride and 2-hydroxyethyl methacrylate (50% in toluene), provided 45.72 g of polyester 1, 88.59 g VPEG 2000 23.43 g Peroxan ^® PO, 5.25 g Peroxan ^® BP-25 WD in 75 g toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® PO reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water. _ -

Example 9

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 25.94 g of butyl acrylate, 6.76 g of methyl methacrylate, 4.80 g of butyl methacrylate, 7.03 g of styrene, 31.83 g of dimethylaminoethyl methacrylate, 35.62 g of polyester 1, 138.03 g of VPEG submitted in 2000, 0.68 g of dodecyl mercaptan, 5.54 g AZDN Peroxan ^® in 70 g toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® AZDN reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 10

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 34.61 g of butyl acrylate, 18.03 g of methyl methacrylate, 6.40 g of butyl methacrylate, 9.38 g of styrene, 41.46 g of reaction product of succinic anhydride and 2-hydroxyethyl methacrylate (50% in toluene), provided 21.24 g of dimethylaminoethyl methacrylate, 47.52 g of polyester 1, 92.08 g VPEG 2000 1.00 g of dodecyl mercaptan and 8.13 g of AZDN Peroxan ^® in 70 g toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® AZDN reacted until complete conversion is reached. For the tion, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Example 11

In a three-necked flask equipped with stirrer, dropping funnel and reflux condenser, 125 g of toluene are introduced, heated to boiling and purged with nitrogen. In the dropping funnel, a mixture of 25.63 g of butyl acrylate, 10.02 g of methyl methacrylate, 4.74 g of butyl methacrylate, 6.95 g of styrene, 30.71 g of reaction product of succinic anhydride and 2-hydroxyethyl methacrylate (50% in toluene), provided 15.73 g of dimethylaminoethyl methacrylate, 35.19 g of polyester 1, 136.39 g VPEG 2000 0.74 g of dodecyl mercaptan and 6.02 g of AZDN Peroxan ^® in 70 g toluene and added dropwise during approximately 2 hours. During the addition, the contents of the flask are kept at boiling heat and stirred. After the end of the addition, the conversion is checked by analysis of the solid and unreacted monomers if necessary by adding small amounts Peroxan ^® AZDN reacted until complete conversion is reached. For workup, the toluene is distilled off and replaced by water. Residual amounts of toluene are removed as an aqueous azeotrope. The solids content of the solution is finally adjusted to about 40% by weight with water.

Testing the graft polymers obtained in Examples 1 to 11

The Colorimetric values were determined with the device spectro-guide ^® from. Byk-Gardner. The calculation of the corresponding color intensity was carried out using the Kubelka-Munk theory. Details of this theory are in Kittel, "Textbook of coatings and coatings", Volume 5, S. Hirzel Verlag Stuttgart, 2003, pages 277-360, described. Test 1: Color intensity and gloss when using organic color pigments

From the graft polymers obtained in Examples 5 and 7 and with a commercially available dispersant (Disperbykl90, BYK-Chemie, Wesel, DE), the pigment paste concentrates listed in Table 1 were prepared on the basis of water. These colored pigment paste concentrates were then incorporated into a white pigmented painter paint and applied the resulting paint color with a 200 micron doctor blade on cardboard cards (byko-charts ^® , Byk-Gardner GmbH, Geretsried, DE). To determine the quality of dispersion, color strength and gloss were then determined in comparison with the commercially available dispersant.

For the preparation of the pigment pastes, the following pigments were used:

Heliogen ^® Green L9361 BASF AG, Ludwigshafen, DE

Hostaperm ^® Rosa E Clariant GmbH

Hostaperm ^® Rubine D3B Clariant GmbH Heliogen ^® Blue L6989F BASF AG

Novoperm ^® Red F5RK Clariant GmbH

Table 1: Composition of the pigment paste concentrates

¹ : Tego

² : 2-amino-2-methylene-1-propanol, Angus Chemie GmbH, Ibbenbüren, DE

The colored pigment paste concentrates were incorporated in a ratio of 1:25 into a white lacquer (Opus 1, white, gloss, J.W. Ostendorf, Coesfeld, DE). The color strength and gloss respectively achieved for the different-colored paints are given in Tables 2a and 2b.

Table 2a: Delta color strength Nos. 5 and 7 for different colored paints

L9361 Pink E D3B L9689F F5RK

No. 5 0.8 6, 4 0 12.7 2, 2

No. 7 2.2 3, 2 1.0 11.9 9, 5

Table 2b: Delta Gloss Nos. 5 and 7 for different colored paints

L9361 Pink E D3B L9689F F5RK

No. 5 o, 1 19, 3 0.8 o, 5 4.8

No. 7 1, 1 12, 0 3.0 1, 6 0.4 - -

Test 2: Color intensity and gloss when using inorganic color pigments

With the graft polymer obtained from Example 6, the pigment paste concentrates listed in Table 3 were prepared, incorporated the concentrates in a white paste and applied the resulting varnish in the manner described in the test 1 on cardboard cards and measured each color strength and gloss. For the preparation of the pigment paste concentrates, the following pigments were used.

Bayferrox ^® 130 M Lanxess AG, Leverkusen, DE Bayferrox ^® 3920 Lanxess AG Sicopal ^® L 1120, BASF AG, Ludwigshafen, DE Sicopal ^® L 1600, BASF AG

Table 3: Composition of the pigment paste concentrates

L 1120 L 1600 130 M 3920

Pigment 50 50 60, 5 60, 5

Dispersant 17.5 17.5 13, 5 13, 5

Water 32.5 32.5 24, 5 24, 5

The pigment paste concentrates were incorporated in a ratio of 1:10 into a white painter's paint (Opus 1, white, glossy), applied to cardboard cards in the manner described above, and the color strength and gloss were determined. The results are summarized in Tables 4a and 4b. - -

Table 4a: Delta color strength No. 6 for different colored paints

Table 4b: Delta Gloss No. 6 for different colored paints

Test 3: Color intensity and gloss when using pigmented blacks

With the results obtained in Examples 2, 6 and 11 the graft polymer, the pigment paste concentrates listed in Table 5 were prepared, the concentrates in a non-pigmented binder (Necowel ^® 5088; Ashland-Südchemie-Kernfest GmbH, Hilden, DE) incorporated, and the varnish thus obtained in the test described on the test 1 on glass plates. For the preparation of the pigment paste concentrates, the following pigment blacks were used.

FW 200 Degussa AG, Dusseldorf, DE FW 285 Degussa AG Table 5: Composition of the pigment paste concentrates

The pigment paste concentrates were incorporated in a ratio of 1:25. The dispersing quality was determined by the black degree My, the blue shift ddM and the gloss. This colorimetric determination was carried out according to Mathias J. Lippok-Lohmer K., Welt der Farben, 10/1997, pp. 28-30, "Method for measuring color-deep pigment blacks." The results are summarized in Tables 6a, 6b and 6c ,

Table 6a: Black grade dMy for different colored paints

Table 6b: Blue shift ddM for different colored paints

- -

Test 4: Color intensity and gloss when using white pigments

(Ashland-Südchemie-Kernfest GmbH, Hilden, DE Necowel ^® 5088) are incorporated for producing a titanium oxide coating painter were in a base resin. The recipe is shown in Table 7. The following white pigments were used:

Titanoxid 2160 Kronos Worldwide Inc., Dallas, USA Titanoxid 2190 Kronos Titanoxid 2310 Kronos

Table 7: Composition of the paintwork

3. Elementis Specialties, Inc., Hightstown, NJ, USA

The paintwork was applied to cardboard cards as explained in test 1. To determine the quality of dispersion, the differences in gloss with respect to the samples were measured with the reference dispersant. The results are shown in Tables 8a and 8b. - -

Table 8a: Delta gloss for various white pigments

Furthermore, the white pastes were incorporated into a black pigmented paint from test 3. Here, the whitening power was determined as color strength. The greater the lightening of the black lacquer, the higher the whitening power or the color intensity.

Table 8b: Delta color strengths (whitening power) for various white pigments

2160 2190 2310

No. 1 2,1 o, 8 2,4

No. 2 2,8 6, 0 11,3

No. 6 3.5 o, 8 8.5

No. 8 5.9 13, 8 4.4

No. 9 8,1 15, 9 11,2

No. 10 0,1 1, 9 1,5

No. 11 0.6 0, 7 7.0

Claims

Patentanspüche

1. Graft polymer obtainable by copolymerization of:

at least one macromonomer of the formula 1

formula 1

in which means:

R ⁴ , R ⁵ : each independently, a hydrogen atom or a methyl group;

R ⁶ : a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a sulfate group, a phosphate group or a monoester of a dicarboxylic acid, and salts thereof;

n: 5 to 500; and at least one other monomer having a polymerizable ethylenically unsaturated double bond.

2. A graft polymer according to claim 1, wherein the at least one further monomer has a molecular weight of less than 5,000 g / mol.

3. Graft polymer according to one of the preceding claims, having an average molecular weight of 5,000 to 200,000 g / mol, determined by Gößeausschlusschromatographie.

The graft polymer according to any one of the preceding claims, wherein the at least one macromonomer of formula 1 is contained in a proportion of at least 1 mol% in the graft polymer.

5. Graft polymer according to one of the preceding claims, wherein the at least one further monomer is selected from acrylic acid, methacrylic acid, derivatives of these acids, and styrene.

The graft polymer according to claim 5, wherein the derivative of (meth) acrylic acid is selected from alkyl esters, hydroxyalkyl esters and alkylamides of (meth) acrylic acid in which the alkyl group has 1 to 22 carbon atoms.

7. A process for the preparation of a graft polymer according to claim 1, wherein at least one macromonomer of formula 1 and at least one further monomer having a polymerizable ethylenically unsaturated double bond is provided and the monomers are radically polymerized in a homogeneous or heterogeneous phase. _

8. The method of claim 7, wherein a solution or an aqueous emulsion of the at least one macromonomer of formula 1 and the at least one other monomer is prepared in a solvent or water and the monomers are radically polymerized.

9. The method of claim 7 or 8, wherein for the radical polymerization, a radical initiator is added to the solution or to the aqueous emulsion.

10. The method according to any one of claims 7 to 9, wherein the solution is added to a chain transfer agent.

A dispersion at least comprising a dispersion medium and a solid and a graft polymer according to any one of claims 1 to 6.

The dispersion of claim 11, wherein the solid is a pigment.