AU743111B2 - Aqueous composition comprised of a carbonyl polymer dispersion, a pigment, and a polyamine - Google Patents

Description

O.Z. 0050/48506 AQUEOUS COMPOSITIONS COMPOSED OF CARBONYL POLYMER DISPERSIONS, PIGMENT AND POLYAMINE The present invention relates to emulsion paints comprising as binder at least one aqueous polymer dispersion (component A) whose polymer is functionalized with keto and/or aldehyde groups.

Emulsion paints are one of the largest product groups of the paints and coatings industry (see Ullmanns Enzyklopddie der technischen Chemie, 4th Ed., Vol. 15, Verlag Chemie, Weinheim 1978, p. 665). Emulsion paints generally include as binder a film-forming polymer and as color-imparting constituent at least one inorganic pigment, and also inorganic fillers and auxiliaries such as defoamers, thickeners, wetting agents and, in some cases, film-forming auxiliaries.

The quality of emulsion paint is critically determined by the ability of the film-forming polymer to bind the non-film-forming constituents, the pigments and the inorganic fillers, equally.

The pigment-binding capacity of the binder is particularly important in emulsion paints having a high content of inorganic pigments and fillers, characterized by a pigment volume concentration of 40%. The p.v.c. is usually defined as the quotient of the overall volume of the solid inorganic constituents (pigment fillers) divided by the overall volume of the solid inorganic constituents and of the polymer particles of the aqueous binder polymer dispersion; see Ullmanns Enzyklopddie der technischen Chemie, 4th Ed., Vol. 15, p. 668. A low pigment-binding capacity leads to poor mechanical stability of the coating, which is manifested, for example, in a low wet abrasion resistance. The desire, however, is for a high wet abrasion resistance, especially in the case of washable emulsion paints. It must also be ensured that the binder has a sufficiently low film-forming temperature to permit the coating material to be used even at low temperatures. At the same time, the binder polymer must not be so soft that it does not ensure sufficient strength or so tacky that it fails to avoid becoming soiled.

Especially in the case of exterior applications, the emulsion paints should be stable to environmental influences such as sunlight, moisture and fluctuations in temperature. In addition, 4 the coating should adhere well to a variety of substrates, which again depends on the chosen binder polymer.

Another property dependent on the binder polymer is the blocking resistance of the coatings.

EP-A-184 091 describes coating compositions based on aqueous polymer dispersions which have a low film-forming temperature and form films of high blocking resistance. The polymer dispersions disclosed therein may also comprise, in copolymerized form, monomers having a crosslinking action. The coating materials described include only small amounts of inorganic substances and pigments.

EP-A-327 006 and EP-A-327 376 disclose emulsion paints based on aqueous polymer dispersions comprising siloxane-functional monomers in copolymerized form. Such monomers, however, are expensive, with even a small amount pushing up the binder preparation costs sharply. It must also be reckoned that hydrolysis of the siloxane groups will alter the properties of the binder in the course of storage.

US-A 4,219,454 describes binders for coating materials, such as emulsion paints, which are based on aqueous polymer dispersions comprising, in copolymerized form, urea-functional monomers for improving the adhesion of the coatings in the moist state (wet adhesion). The coatings described therein, however, again have only low pigment contents. The problem of the wet abrasion resistance of coating materials with a p.v.c. of 40% is hence not adequately solved by the polymers described therein.

DE-A-25 35 374 discloses emulsion paint binders comprised of copolymerized monomers having cyanoacetyl or acetoacetyl groups.

The coatings feature improved wet adhesion and also good adhesion to hydrophobic substrates. The emulsion paints described therein, however, have only a low content of inorganic pigments.

US-A-3,345,336 describes polymers having carbonyl groups which can be crosslinked with hydrazides of polybasic carboxylic acids.

In the crosslinked state the polymers are resistant to solvents.

They are used to treat leather, textile materials and paper.

The prior patent application US 08/720,977 discloses sealing-compound binders comprising at least one compound having two primary amino groups, and at least one keto-functionalized polymer. Use of the binders in emulsion paints having a p.v.c. of 40% is not proposed. Similar binders are employed in EP-A-5167 3 for coating compositions with a low pigment content and for colored stone plasters.

The prior art binders are able to go only some of the way toward meeting the requirements placed on emulsion paints with a p.v.c.

of It is an object of the present invention to provide an emulsion paint having a p.v.c. of 40% and possessing a high pigmentbinding capacity, and hence a high wet abrasion resistance, good wet adhesion to a very wide variety of substrates, and good blocking resistance.

We have found that this object is achieved by using for the emulsion paints, binders based on aqueous polymer dispersions whose polymers have been modified with aldehyde and/or keto groups.

The present invention accordingly provides emulsion paints comprising i. as binder a formulation comprising as component A at least one aqueous polymer dispersion whose polymer P possesses functional groups of the formula 0

II

C-R

1 where

R

1 is hydrogen, alkyl, cycloalkyl, aryl or aralkyl and X is attached to a carbon of the polymer chain and is a single bond, alkylene, arylene, -R 2 -0-R 3

-R

2

-Z-O-R

3

-R

2

-Z-CH

2

-R

3

-R

2

-Z-N(R

4

-R

3

R

2 -O-Z-0-R 3

-R

2

-O-Z-CH

2

-R

3

-R

2

-O-Z-N(R

4

)-R

3

-R

2

-N(R

5

)-Z-O-R

3

-R

2

-N(R

5

-Z-CH

2

-R

3 or -R 2

-N(R

5

)-Z-N(R

4

)-R

3 where

-R

2 -is a single bond, alkylene, oxyalkylene, polyoxyalkylene or arylene and is attached to the polymer,

-R

3 is C 1

-C

4 -alkylene or arylene, Z is SO 2 or C=O, and

R

4 and R 5 independently are hydrogen, alkyl, cycloalkyl, aryl, aralkyl or -R 3

-(CO)-R

1 where R 1 and R 3 are as defined above and as component B comprises at least one compound having at least two NH 2 groups that are reactive toward the carbonyl groups of the polymer of component A; ii. at least one inorganic pigment, iii.if desired, one or more inorganic fillers, and iv. customary auxiliaries, the ratio of binder to the overall amount of the constituents ii 2and iii being reflected in a characteristic pigment volume concentration of In the text below alkyl is preferably linear or branched

C

1

-C

12 -alkyl, especially C 1

-C

8 -alkyl, such as methyl, ethyl, n-propyl, isopropyl, 1-butyl, 2-butyl, isobutyl, t-butyl, 1-pentyl, 2-pentyl, 3-pentyl, 1-hexyl or 2-ethylhexyl. Cycloalkyl is preferably cyclopentyl or cyclohexyl. Aryl is preferably phenyl or naphthyl unsubstituted or substituted by 1 to 4 substituents selected independently from C 1

-C

4 -alkyl, especially methyl or ethyl, C 1

-C

4 -alkoxy, such as methoxy or ethoxy, hydroxyl, which can also if desired be ethoxylated, and halogen.

Alkylene is a linear or branched divalent alkyl, preferably a

C

1

-C

12 -alkyl, such as methylene, 1,1- or 1,2-ethylene, 1,2-, 2,2-propylene, l-methyl-l,2-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene and 1,8-octylene. Arylene is a divalent aryl, preferably 1,2- or 1,4-phenylene. Aralkyl is an aryl attached to the respective center via an alkylene.

Oxyalkylene is an alkylene attached to the polymer via an oxygen and hence polyoxyalkylene denotes alkylene units each attached to one another by way of oxygens.

The polymers P present in the binder formulations of the invention share the characteristic feature of having carbonyl groups which are able to undergo reaction with NH 2 groups to form a bond and yet do not react with one another. The carbonyls (CO) are attached to the polymer either directly or via a bridge X.

The carbonyls may carry the substituents customary for them.

Accordingly, the functional groups present in the polymers can be described by the formula -X-(CO)-R 1

R

1 is preferably hydrogen or Cl-C 4 -alkyl, especially hydrogen or methyl. In the preferred embodiments the bridge X can be a single bond, C 1

-C

6 -alkylene or, in particular, -R 2

-Z-O-R

3 or

-R

2

-Z-N(R

4

)-R

3 In these latter groups R 2

R

3 and Z are as defined above, Z preferably being CO, R 2 a single bond or

C

1

-C

4 -alkylene and R 3

C

1

-C

6 -alkylene, especially methylene, or 1-methyl-1,2-propylene, or p-phenylene. R 4 is preferably hydrogen,

C

1

-C

4 -alkyl or -R 3 where R 1 and R 3 are as defined above, preferably with the preferred definitions above. With particular preference, X, Z, R 1

R

2

R

3

R

4 and R 5 all have the above preferred definitions.

Polymers P which comprise the keto or aldehyde groups of the invention are obtainable in a variety of ways. For instance, keto or aldehyde groups can be generated by converting existing functionalities in the manner of a polymer-analogous reaction.

Examples of this are the reaction of any double bonds present in the polymer with carbonylating reagents or the oxidation of aliphatic OH groups to give carbonyl groups. The CO groups of the invention can also be introduced into the polymer, in the manner of a polymer-analogous reaction, with the aid of low molecular mass compounds which in turn include both one or more keto or aldehyde groups and at least one different functional group which is able to react, forming bonds, with the functional groups present in the polymer. The second type of reaction can be implemented, for example, by reacting the OH and/or NH 2 groups that may be present in the polymer with compounds which are amenable to nucleophilic substitution reactions, examples being a-halocarbonyl compounds such as chloroacetone.

Preferably, however, the polymers P are prepared by free-radical copolymerization of at least one ethylenically unsaturated monomer a with at least one ethylenically unsaturated monomer b of the formula I

R

7

-CH=C(R

6 (CO)-Rl (I) where R 6 is hydrogen or methyl, R 7 is hydrogen, C 1

-C

4 -alkyl or a functional group -X-(CO)-R 1 and X and R 1 are as defined above. R 7 is preferably hydrogen. With very particular preference, the monomers b are the esters of a,p-ethylenically unsaturated C 3

-C

8 mono- or dicarboxylic acids with alcohols which carry a carbonyl group, or are the amides of said carboxylic acids that carry on the nitrogen one or two substituents containing a carbonyl group.

6 Examples of suitable a,p-ethylenically unsaturated C 3

-C

8 carboxylic acids are acrylic, methacrylic, crotonic, maleic, itaconic, citraconic and fumaric acid. Examples of suitable alcohols are glycol aldehyde, hydroxyacetone, P-hydroxypropanal, 1-hydroxybutan-2-one, 3-hydroxybutan-2-one, 4-hydroxybutan-2-one, 4-hydroxypentan-2-one, p-hydroxyacetophenone, etc. Examples of suitable substituents on the amide nitrogen are 1-oxoethan-2-yl, 1-oxopropan-2-yl, 2-oxopropan-1-yl, 2-oxobutan-1-yl, 2-oxobutan-3-yl, 2-oxobutan-4-yl, 2-oxopentan-4-yl, 2-oxo-4-methylpentan-4-yl or p-acetylphenyl. Further suitable monomers b are ethylenically unsaturated aldehydes, such as acrolein, methacrolein, formylstyrene and (meth)acryloxyalkylpropanals, such as 3-acryloxy-2,2-dimethylpropanal acryloxypivalyl aldehyde), which are obtainable in accordance with DE-A-27 22 097 by esterifying P-hydroxyalkylpropanals with acrylic or methacrylic acid. Also suitable are alkyl and aryl vinyl ketones, such as methyl, ethyl, isobutyl and phenyl vinyl ketone and corresponding allyl alkyl ketones and allyl aryl ketones. Preference is given to the diacetoneamides of the abovementioned ethylenically unsaturated carboxylic acids and their esters with hydroxyacetone or diacetonyl alcohol 1,1-dimethyl-3-oxobutan-1-ol), especially the amides and/or the esters of acrylic or methacrylic acid. Diacetoneacrylamide or diacetonemethacrylamide (1-acrylamido- or 1-methacrylamido-1,1l-dimethyl-3-oxobutane, respectively) are used especially as monomers b. Such monomers preferably make up from 0.1 to 10% by weight and, in particular, from 0.5 to 5% by weight and, with particular preference, from 1 to 3% by weight of the overall monomer amount.

Suitable monomers a are selected from vinylaromatic monomers such as styrene, a-methylstyrene, ortho-chlorostyrene or vinyltoluenes, vinyl esters of C 1

-C

18 preferably C 1

-C

12 monocarboxylic acids, such as vinyl acetate, propionate, butyrate, valerate, hexanoate, 2-ethylhexanoate, decanoate, laurate and stearate and vinyl esters of Versatic® acids (Versatic acids are branched, aliphatic carboxylic acids having to 11 carbons). Also suitable are esters of a,p-ethylenically unsaturated C 3

-C

8 mono- or dicarboxylic acids with preferably 4 C 1

-C

1 2 and especially C 1 -CB-alkanols or Cs-C 8 -cycloalkanols.

Examples of suitable C 1

-C

1 2 -alkanols are methanol, ethanol, n-propanol, i-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, n-hexanol and 2-ethylhexanol. Examples of suitable cycloalkanols are cyclopentanol or cyclohexanol. Particularly suitable are esters of acrylic, methacrylic, crotonic, maleic, itaconic, citraconic or fumaric acid. Specifically these are methyl, ethyl, isopropyl, n-butyl, isobutyl, 1-hexyl, tert-butyl or 2-ethylhexyl (meth)acrylates, dimethyl maleate or di-n-butyl maleate. Also suitable are nitriles of a,p-monoethylenically unsaturated C 3

-C

8 carboxylic acids, such as acrylonitrile or methacrylonitrile. It is also possible to employ C 4 -C8 conjugated dienes, such as 1,3-butadiene, isoprene or chloroprene, C 2

-C

6 olefins, such as ethylene, propene, 1-butene and isobutene, or vinyl chloride as monomers a. Said monomers a make up preferably from 80 to 99.9% by weight, in particular from 90 to 99.9% by weight and, especially, from 95 to 99.7% by weight, based on the overall weight of the monomers employed. The monomers a preferably include at least two different monomers al and a2.

These are preferably selected from the abovementioned vinylaromatic monomers, from the esters of acrylic and methacrylic acid with Ci-C 12 -alkanols, from the vinyl esters of aliphatic

C

1

-C

12 carboxylic acids and from ethylene and vinyl chloride. The two latter monomers are preferably employed in combination with vinyl acetate or vinyl propionate.

The polymer P may also include monomers c in copolymerized form, the homopolymers of which are of increased solubility or swellability in water. These monomers can be copolymerized in amounts of up to 10% by weight, preferably up to 5% by weight, based on the overall monomer amount. Such monomers raise the stability of the polymer dispersions employed as binders. They include monomers cl containing acid groups, such as a,3-monoethylenically unsaturated mono- and dicarboxylic acids of 3 to 10 carbons, and ethylenically unsaturated sulfonic acids, phosphonic acids or dihydrogenphosphates and the water-soluble salts thereof. Examples of monomers c having acid groups are the abovementioned ethylenically unsaturated C 3

-C

8 carboxylic acids or

C

4

-C

8 dicarboxylic acids, especially acrylic or methacrylic acid, and also sulfonic acids, such as vinyl- and allylsulfonic acid, (meth)acrylamidoethanesulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, phosphonic acids such as vinylphosphonic acid, allylphosphonic acid, 2-acrylamido-2-methylpropane-lphosphonic acid, phosphonoethyl acrylate and the alkali metal salts thereof, especially the sodium salts. The monomers c also embrace neutral or nonionic, modifying monomers c2, examples being the amides, N-alkylolamides or hydroxyalkyl esters of the above carboxylic acids, for instance acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, 2-hydroxyethylacrylamide, 2-hydroxyethylmethacrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate.

«t 8 It is also possible for the polymer P to contain crosslinking monomers d in copolymerized form. These monomers d are used if desired in a minor amount, that is, in amounts from 0.1 to 5% by weight and, in particular, of up to 1% by weight, based on the overall monomer amount. They preferably comprise monomers having two nonconjugated, ethylenically unsaturated bonds, examples being the diesters of dihydric alcohols with a,p-monoethylenically unsaturated C 3

-C

8 carboxylic acids, such as glycol bisacrylate, or esters of a,p-unsaturated carboxylic acids with alkenols, such as bicyclodecenyl (meth)acrylate. In a preferred embodiment the polymer P contains no copolymerized monomers d.

The polymers P can of course also comprise monomers which are known to improve the pigment binding power. Examples of these include siloxane-functional monomers, such as the vinyltrialkoxysilanes, vinyltrimethoxysilane for example, the alkylvinyldialkoxysilanes or the (meth)acryloxyalkyltrialkoxysilanes, such as (meth)acryloxyethyltrimethoxysilane or (meth)acryloxypropyltrimethoxysilane. These monomers can be used in amounts of up to 1% by weight, preferably from 0.05 to 0.5% by weight, based on the overall monomer amount.

The polymers P can of course also include in copolymerized form the prior art monomers known to improve wet adhesion. These include ethylenically unsaturated compounds with urea groups, such as N-vinyl- and N-allylurea, and polymerizable derivatives 3of imidazolidin-2-one, such as N-vinyl- and N-allylimidazolidin-2-one, N-vinyloxyethylimidazolidin-2-one, N-(2-(meth)acrylamidoethyl)imidazolidin-2-one, N-(2-(meth)acryloxyethyl)imidazolidin-2-one, N-[2-((meth)acryloxyacetamido)ethyl]imidazolidin-2-one etc.

The character of the emulsion paints of the invention is also dependent on the glass transition temperature (DSC, midpoint temperature, ASTM D 3418-82) of the polymer P. If Tg is too low, the coating is not very strong and tears when subjected to mechanical loading. If it is too high, the polymer no longer forms a film and the coating thus exhibits a reduced wet abrasion resistance. The glass transition temperature of the binder polymers P in question is therefore generally below 800C, preferably below 600C and, with particular preference, below 400C.

In general, however, it is above -600C, preferably above -10 0

C

and, in particular, above 0OC. In this context it proves useful to estimate the glass transition temperature Tg of the dispersed polymer. According to Fox Fox, Bull. Am. Phys. Soc. (Ser.

II) 123 [1956] and Ullmanns Enzyklopddie der technischen Chemie, Weinheim (1980), p. 17, 18) the glass transition temperature of copolymers at high molar masses is given in good approximation by 1 X 1 x 2 Xn T, Tg 1 Tg2 Tg where X 1

X

2 X" are the mass fractions 1, 2, n and Tg 1 Tg 2 Tg" are the glass transition temperatures of the homopolymers of 1, 2, n, in degrees Kelvin. These temperatures are known, for example, from Ullmann's Encyclopedia of Industrial Chemistry, VCH, Weinheim, Vol. A 21 (1992) p. 169 or from J. Brandrup, E.H. Immergut, Polymer Handbook 3 r d ed., J.

Wiley, New York 1989.

From what has been said above it is clear that the glass transition temperature of the polymer P can be adjusted both by means of an appropriate principal monomer a having a glass transition temperature within the desired range and by a combination of at least one monomer al whose homopolymer has a high glass transition temperature and at least one monomer a2 whose homopolymer has a low glass transition temperature.

In a preferred embodiment of the present invention the monomers a making up the polymer of component A include at least one monomer al whose homopolymer, for the limiting case of a very high molecular weight, has a glass transition temperature Tg of 300C, and at least one monomer a2 whose homopolymer has a glass transition temperature Tg of 200C. Monomers al suitable for this purpose are, for example, styrene, a-methylstyrene, methyl methacrylate, ethyl methacrylate, n- and isopropyl methacrylate, iso- and tert-butyl methacrylate, vinyl acetate and also tert-butyl acrylate, and acrylonitrile and methacrylonitrile, the nitriles preferably making up not more than 30% by weight of the monomers al. Examples of suitable monomers a2 are the Ci-C 12 -alkyl acrylates, butadiene, vinyl propionate, vinyl esters of Versatic® acids, and especially ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate. Particular preference is given to monomer combinations al/a2 which comprise styrene and/or methyl methacrylate and also n-butyl acrylate with or without 2-ethylhexyl acrylate.

4In a particularly preferred embodiment of the present invention the binder polymer is composed of: i) from 25 to 70% by weight, preferably from 35 to 60% by weight of monomers al, especially styrene and/or methyl methacrylate, ii) from 30 to 70% by weight, preferably from 40 to 60% by weight of monomers a2, especially n-butyl acrylate and/or 2-ethylhexyl acrylate, iii) from 0.1 to 5% by weight, preferably from 0.5 to 3% by weight, of at least one monomer b, especially diacetoneacrylamide and/or diacetonemethacrylamide, and iv) from 0.1 to 5% by weight, preferably from 0.2 to 3% by weight of monomers c, in particular an ethylenically unsaturated carboxylic acid, the amides thereof, ethylenically unsaturated phosphonic acids and, with particular preference, acrylic, methacrylic and vinylphosphonic acid, the parts by weight of the monomers al, a2, b and c adding up to 100% by weight.

It has additionally proven advantageous if the polymer particles of the binder dispersion (component A) have a median polymer particle diameter in the range from 50 to 1000 nm (determined by means of an ultracentrifuge or by photon correlation spectroscopy; regarding the determination of particle size see W.

Machtle, Angew. Makromolekulare Chemie 1984, 185, 1025-1039, W.

Machtle op. cit. 1988, 162, 35-42). In the case of binders having high solids contents, such as 50% by weight, based on the overall weight of the binder dispersion, it is advantageous on grounds of viscosity for the ponderal median particle diameter of the polymer particles of the dispersion to be 250 nm. The median particle diameter will preferably not exceed 600 nm.

The aqueous polymer dispersions employed in accordance with the invention are prepared preferably by free-radical aqueous emulsion polymerization of the abovementioned monomers in the presence of at least one free-radical polymerization initiator with or without a surface-active substance.

Suitable free-radical polymerization initiators are all those capable of triggering a free-radical aqueous emulsion polymerization. They can be peroxides, for example alkali metal peroxodisulfates, or azo compounds. It is preferred to use redox initiator systems, which are composed of at least one organic reducing agent and at least one peroxide and/or hydroperoxide, examples being tert-butyl hydroperoxide with a sulfur compound such as the sodium salt of hydroxymethanesulfinic acid, sodium sulfite, sodium disulfite, sodium thiosulfate or acetone bisulfite, or hydrogen peroxide with ascorbic acid. It is also possible to use for this purpose redox initiator systems which comprise a small amount of a metal compound which is soluble in the polymerization medium and whose metal component can exist in a plurality of valence states, an example of such a system being ascorbic acid/iron(II) sulfate/hydrogen peroxide, where the ascorbic acid is frequently replaced by the sodium salt of hydroxymethanesulfinic acid, acetone bisulfite, sodium sulfite, sodium hydrogensulfite or sodium bisulfite and the hydrogen peroxide by organic peroxides, such as tert-butyl hydroperoxide, alkali metal peroxodisulfates and/or ammonium peroxodisulfate.

Initiators which are likewise preferred are peroxodisulfates, such as sodium peroxodisulfate or ammonium peroxodisulfate. The amount of the free-radical initiator systems employed, based on the overall amount of the monomers to be polymerized, is preferably from 0.1 to 2% by weight.

Surface-active substances suitable for conducting the emulsion polymerization are the emulsifiers and protective colloids commonly employed for this purpose. The surface-active substances are normally employed in amounts of up to 10% by weight, preferably from 0.5 to 5% by weight and, in particular, from 1 to 4% by weight, based on the monomers to be polymerized.

Examples of suitable protective colloids are polyvinyl alcohols, starch and cellulose derivatives, or vinylpyrrolidone copolymers.

An exhaustive description of further suitable protective colloids is given in Houben-Weyl, Methoden der organischen Chemie, Volume XIV/1, Makromolekulare Stoffe [macromolecular substances], Georg-Thieme Verlag, Stuttgart 1961, pp. 411-420. Mixtures of emulsifiers and/or protective colloids can also be used. As surface-active substances it is preferred to employ exclusively emulsifiers, whose relative molecular weights, unlike those of the protective colloids, are usually below 2000. They can be 4anionic, cationic or else nonionic in nature. The anionic emulsifiers include alkali metal and ammonium salts of alkyl sulfates (alkyl: C 8

-C

12 of sulfuric monoesters of ethoxylated alkanols (EO units: 2 to 50, alkyl: C 12 to C 18 and of ethoxylated alkylphenols (EO units: 3 to 50, alkyl: C 4

-C

9 of alkylsulfonic 4acids (alkyl: C 12

-C

18 and of alkylarylsulfonic acids (alkyl: C 9

C

18 Further suitable emulsifiers are given in Houben-Weyl, loc.

Scit., pp 192-208.

The anionic surface-active substances also include compounds of the formula II,

R

1

R

2

(II)

SO

3 X SO 3

Y

where R 1 and R 2 are hydrogen or C 4

-C

24 -alkyl but are not both hydrogen, and X and Y can be alkali metal and/or ammonium ions.

In the formula II R 1 and R 2 are preferably linear or branched

C

6

-C

18 alkyls or hydrogen, and especially have 6, 12 or 16 carbons but are not both hydrogen. X and Y are preferably sodium, potassium or ammonium, with sodium being particularly preferred.

Particularly advantageous compounds II are those in which X and Y are sodium, R 1 is a branched alkyl of 12 carbons and R 2 is hydrogen or is the same as R 1 Use is frequently made of technical-grade mixtures which have a proportion of from 50 to 90% by weight of the monoalkylated product, an example being Dowfax® 2A1 (trademark of Dow Chemical Company). The compounds II are widely known, for example from US-A-4,269,749, and are obtainable commercially.

In addition to these anionic emulsifiers it is also possible to use nonionic emulsifiers. Suitable nonionic emulsifiers are araliphatiic or aliphatic nonionic emulsifiers, examples being ethoxylated mono-, di- and trialkylphenols (EO units: 3 to alkyl: C 4

-C

9 ethoxylates of long-chain alcohols (EO units: 3 to 50, alkyl: C 8

-C

36 and also polyethylene oxide/polypropylene oxide block copolymers. Preference is given to ethoxylates of long-chain alkanols (alkyl: C 10

-C

22 mean degree of ethoxylation: 3 to 50) and, of these, particular preference to those based on oxo alcohols and naturally occurring alcohols having a linear or branched C 12

-C

18 -alkyl radical and a degree of ethoxylation of from 8 to 50. It is preferred to use anionic emulsifiers or combinations of at least one anionic and one nonionic emulsifier.

The molecular weight of the polymers can be adjusted by adding small amounts, generally up to 2% by weight, based on the monomers to be polymerized, of one or more molecular weight regulators, such as organic thio compounds, silanes, allyl alcohols or aldehydes, for example.

The emulsion polymerization can be conducted either continuously or by the batch procedure, preferably by a semicontinuous procedure. In this case the monomers to be polymerized can be 13 supplied continuously, including by a stepwise or gradient procedure, to the polymerization batch.

In addition to the seed-free preparation mode it is also possible, in order to establish a defined polymer particle size, to conduct the emulsion polymerization by the seed latex process or in the presence of seed latex prepared in situ. Processes for this purpose are known and can be taken from the prior art (see EP-B 40419, EP-A-614 922, EP-A-567 812 and literature cited therein, and also 'Encyclopedia of Polymer Science and Technology', Vol. 5, John Wiley Sons Inc., New York 1966, p.

847).

The polymerization is preferably conducted in the presence of from 0.01 to 3% by weight and, in particular, from 0.05 to by weight of a seed latex (solids content of the seed latex, based on overall monomer amount), preferably with a seed latex included in the initial charge (initial-charge seed). The latex generally has a weight average particle size of from 10 to 100 nm and, in particular, from 20 to 50 nm. Examples of its constituent monomers are styrene, methyl methacrylate, n-butyl acrylate and mixtures thereof, and to a minor amount it may also include monomers c, preferably less than 10% by weight, based on the overall weight of the monomer particles in the seed latex, in copolymerized form.

The pressure and temperature of polymerization are of minor importance. It is normal to operate at between room temperature and 1200C, preferably at from 40 to 95 0 C and, with particular preference, at from 50 to 900C.

Following the actual polymerization reaction it is possible if desired to render the aqueous polymer dispersions of the invention substantially free from odoriferous substances, such as residual monomers and other volatile organic constituents. This can be done physically in a manner known per se, by distillative removal (especially by steam distillation) or by stripping with an inert gas. The residual monomer content can also be lowered chemically by means of free-radical post polymerization, especially under the action of redox initiator systems, as are set out, for example, in DE-A 44 35 423, DE-A 44 19 518 and DE-A 44 35 422. The post polymerization is preferably conducted with a redox initiator system comprising at least one organic peroxide and one organic sulfite.

14 This makes it possible to obtain polymer dispersions having polymer contents of up to 80% by weight based on the overall weight of the dispersion. As component A it is preferred for practical reasons to employ dispersions having polymer contents in the range from 30 to 70% by weight, especially from 45 to by weight. Dispersions having polymer contents 50% by weight are particularly preferred.

The preparation of polymers which are not provided with the functional groups until afterward (see above) can be carried out by the customary polymerization techniques for ethylenically unsaturated monomers, preferably by free-radical aqueous emulsion polymerization. Suitable monomers are in principle all those specified under a, provided that there is sufficient copolymerization preferably in an amount of from 0.1 to 15% by weight of monomers having functional groups which are able to enter into the desired polymer-analogous reaction (see above).

Particularly suitable for this purpose are conjugated dienes and the monomers c and d. Where the polymers are prepared by emulsion polymerization, the reaction conditions (emulsifiers, initiators, initial charge/feed regime, pressure and temperature) are subject to the comments made above.

In accordance with the invention the binder i of the emulsion paint of the invention comprises, in addition to the aqueous dispersion of the polymer P (component at least one compound having at least two or more NH 2 groups per molecule (component B).

By NH 2 groups are meant the amino functions of primary amines and 3the NH 2 groups in hydrazides of carboxylic or sulfonic acids or of hydrazines. Examples of suitable amines are diamines as are also used in the synthesis of polyamides. Examples of suitable diamines are aliphatic diamines of 4 to 16 carbons, especially 6 to 12 carbons, such as hexamethylenediamine, its alkyl derivatives, such as 2-methylhexamethylenediamine and 3-methylhexamethylenediamine, and also bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane and isophoronediamine. Also suitable are C 4

-C

20 -alkylenediamines in which the alkylene is interrupted by one or more oxygens or by one or more NH and/or N-C 1

-C

4 -alkyl groups, examples being 1,10-diamino-4,7-dioxadecane, 1,12-diamino-4,9-dioxadodecane, diethylenetriamine, triethylenetetramine, dipropylenetriamine, 1,7-diamino-4-azamethylheptane, and also C 4

-C

20 -alkoxydiamines such as bisaminooxybutane. It is preferred as component B to use di- or polyhydrazides of an organic di- or polycarboxylic acid.

The dihydrazides of dicarboxylic acids are used in particular.

Suitable dihydrazides are derived, in particular, from aliphatic

C

2

-C

14 or aromatic C 8

-C

22 dicarboxylic acids. Examples of suitable aliphatic C 2 -C1 4 dicarboxylic acids are oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic and sebacic acid.

Likewise preferred are the dihydrazides of aromatic dicarboxylic acids, for example the dihydrazide of phthalic, isophthalic, terephthalic, 2,6-naphthalenedicarboxylic, 4,4-diphenyl sulfone dicarboxylic, 4,4-diphenylmethanedicarboxylic or 4,4'-diphenyl-2,2-propanedicarboxylic acid, etc. The hydrazides of these dicarboxylic acids can be employed alone, in a mixture with each other, or else in a mixture with diamines. Component B may additionally comprise the compounds having more than two NH 2 groups. These compounds, however, are employed only in a minor amount. In one special embodiment adipic dihydrazide is employed as sole component B.

Component B, which is used in amounts of from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight and, in particular, from 0.2 to 2% by weight, based on the polymer, can be added either directly to the polymer dispersion or not until during the preparation of the coating material.

The emulsion paints of the invention generally contain from 30 to by weight and preferably from 50 to 65% by weight of nonvolatile constituents; by these are meant all those constituents of the emulsion paint except for water or any other solvent, but at least the total amount of binder, filler, pigment and solvents of low volatility, such as plasticizers, and of polymeric auxiliaries. Of these, the amounts accounted for by each class of constituent are i from 5 to 40% by weight, preferably from 10 to 35% by weight, by solid binder constituents solids content of components A and B), ii from 5 to 60% by weight, preferably from 10 to 50% by weight, by at least one inorganic pigment, iii from 0 to 85% by weight, preferably from 20 to 70% by weight, by inorganic fillers, and iv from 0.1 to 40% by weight, preferably from 0.5 to 15% by weight, by customary auxiliaries.

The p.v.c. of the emulsion paints is in accordance with the invention above 40%, preferably above 45%, and can be up to In one embodiment of the present invention it lies above Typical pigments are, for example, titanium dioxide, preferably in the rutile form, barium sulfate, zinc oxide, zinc sulfide, basic lead carbonate, antimony trioxide, and lithopones (zinc sulfide barium sulfate). However, the emulsion paints may also comprise color pigments, such as iron oxides, carbon black, graphite, luminescent pigments, zinc yellow, zinc green, ultramarine, manganese black, antimony black, manganese violet, Paris blue or Schweinfurt green. In addition to the inorganic pigments the emulsion paints of the invention may also include organic color pigments, examples being sepia, gamboge, Cassel brown, toluidine red, para red, Hansa yellow, indigo, azo dyes, anthraquinonoid and indigoid dyes, and also dioxazine, quinacridone, phthalocyanine, isoindolinone and metal complex pigments.

Suitable fillers include alumosilicates, such as feldspars, silicates, such as kaolin, talc, mica, magnesite, alkaline earth metal carbonates, such as calcium carbonate, in the form of calcite or chalk, for example, magnesium carbonate, dolomite, alkaline earth metal sulfates, such as calcium sulfate, silicon dioxide, etc. The fillers can be employed as individual components. In practice, however, filler mixtures have proven especially suitable, such as calcium carbonate/kaolin and calcium carbonate/talc.

To increase the hiding power and to save on the use of white pigments it is common to employ finely divided extenders, such as finely divided calcium carbonate or mixtures of different calcium carbonates with different particle sizes. To adjust the hiding power, the shade and the depth of color it is preferred to employ blends of color pigments and extenders.

The customary auxiliaries iv include wetting agents or dispersants, such as sodium or potassium polyphosphates, alkali metal salts of polyacrylic acids, alkali metal salts of polymaleic acid, polyphosphonates, such as sodium 1-hydroxyethane-1,1-diphosphonate, and the salts, especially the sodium salts, of naphthalenesulfonic acids. The dispersants and/or wetting agents are generally employed in an amount of from 0.1 to 0.6% by weight, based on the overall weight of the emulsion paint.

The auxiliaries iv may also include thickeners, examples being cellulose derivatives, such as methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose, and also casein, gum arabic, tragacanth gum, starch, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, sodium and ammonium salts of polyacrylic acids, water-soluble copolymers based on acrylic and methacrylic acid, such as acrylic acid/acrylamide and methacrylic acid/acrylate copolymers, and also associated thickeners, such as styrene-maleic anhydride, copolymers or, preferably, hydrophobically modified polyether urethanes, as are described, for example, by M. Chen et al. in J. Coatings Techn. Vol. 69, No.

867, 1997, p. 73, and by R.D. Hester et al. in J. Coatings Techn.

Vol. 69, No. 864, 1997, 109. The disclosure content of these documents is hereby incorporated in its entirety by reference.

Examples of hydrophobically modified polyether urethanes are compounds of the formula Rf-HN-C-HN-Sp--NH-C-0-(EtOC-NH-Sp--NH-C-NH-R k 1 where R f is a hydrophobic radical, preferably a linear or branched 2alkyl of 10 to 20 carbons, and Et is 1,2-ethylene, Sp is

C

2

-C

0 i-alkylene, cycloalkylene or arylene, k is from 50 to 1000 and 1 is from 1 to 10, the product k 1 preferably being from 300 to 1000.

Inorganic thickeners, such as bentonites or hectorite, can also be used. Thickeners are generally used in amounts of from 0.1 to 3% by weight, preferably from 0.1 to 1% by weight, based on the overall weight of the aqueous formulation.

The auxiliaries iv generally also include defoamers, preservatives or hydrophobicizing agents, biocides, fibers or other constituents. Furthermore, in order to establish the film-forming properties of the binder polymers, the coating materials may also comprise what are known as film-forming consolidating agents and/or plasticizers. Examples of these include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, alkyl ethers and alkyl ether esters of glycols and polyglycols, butylene glycol and hexylene glycol, such as diethylene glycol monoethyl ether and diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether and diethylene glycol monobutyl ether acetate, hexylene glycol diacetate, propylene glycol monoethyl ether, propylene glycol monophenyl

RA

18 ether, propylene glycol monopropyl ether, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether and propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol n-butyl ether acetate, tripropylene glycol monobutyl ether, alkyl esters of aliphatic mono- and dicarboxylic acids, such as Texanol® from Eastman, for example, or technical-grade mixtures of the dibutyl esters of succinic, glutaric and adipic acid, and also hydrocarbons and/or mixtures thereof with or without aromatic constituents, such as white spirits in the boiling range of from 140 0 C to 2100C. Film-forming auxiliaries are customarily employed in amounts of from 0.1 to 40% by weight, based on the polymer P present in the formulation, so that the formulation has a minimum film-forming temperature of 15 0 C and preferably from 0 to 100C.

The emulsion paints of the invention are stable fluid systems which can be used to coat a large number of substrates. Examples of suitable substrates are wood, concrete, metal, glass, ceramics, plastic, plaster, wallpaper and coated, primed or weathered substrates.

The coatings produced using the emulsion paints of the invention 2 are notable for high wet abrasion resistance and good adhesion in the wet state. Furthermore, they are not tacky, and feature a high blocking resistance.

The advantageous properties of the emulsion paints of the invention, and especially their high blocking resistance, are probably based on the fact that the crosslinking component B is present not in the polymer phase but primarily in the aqueous phase. One consequence of this is that the reaction takes place not until the drying step and then, primarily, at the carbonyl groups on the surface of the polymer particles. There is thus primarily crosslinking between the polymer particles and not within the polymer particles. This raises the blocking resistance of the coatings. Surprisingly, the pigment binding power, and hence the wet abrasion resistance of the emulsion paints, are improved at the same time. An improved wet abrasion resistance, in other words an improved mechanical stability of the coating in the wet state, especially with regard to abrasive influences, is advantageous for the weathering stability of the coatings and also has the effect of rendering the coatings washable. At the same time, the elasticity of the coating is retained.

R

19 The advantageous properties of the binder based on component A are also in evidence in emulsion paints having relatively low pigment volume concentrations. Accordingly, the present invention likewise provides for the use of the binders comprising component A with or without component B for improving the wet abrasion resistance of aqueous emulsion paints.

The examples below are intended to illustrate the invention without restricting it.

I. Preparing and characterizing the polymer dispersions (component A) The average particle size (z-average) of the polymer particles was found by dynamic light scattering (photon correlation spectroscopy) on a 0.01% by weight dispersion in water at 23 0 C using an Autosizer IIc from Malvern Instruments, England. The value stated is the cumulant z-average of the measured autocorrelation function.

The minimum film-forming temperature (MFT) of the polymer dispersions was determined in accordance with Ullmanns Enzyklopddie der technischen Chemie, 4. Ed. Vol. 19, VCH Weinheim 1980, p. 17. The measuring device used was a film formation bench (a metal plate to which a temperature gradient is applied and on which temperature sensors are mounted at different points for the purpose of temperature calibration, the temperature gradient being chosen so that one end of the film formation bench has a temperature above the anticipated MFT and the other end has a temperature below the anticipated MFT). The aqueous polymer dispersion is applied to the film formation bench. In those regions of the bench whose temperature is above the MFT the dispersion dries to form a clear film, whereas in the cooler regions it forms a white powder. The MFT is determined visually on the basis of the known temperature profile of the plate.

Comparison Dispersion CD1 A reactor was charged with 234 g of deionized water, 38 g of aqueous sodium pyrophosphate solution strength by weight) and 4.61 g of a polystyrene seed latex (particle size about 45 30 nm, solids content about 33% by weight). This initial charge was heated to 850C under nitrogen. Then 7.24 g of aqueous initiator solution were added. A monomer emulsion was then added over the course of 3 hours, and the remainder of the initiator solution over the course of 4 hours. After the end of the addition of initiator the temperature was maintained for 1 hour and then lowered to 60 0 C. Subsequently, 6.36 g of a 15% strength by weight aqueous solution of tert-butyl hydroperoxide and 7.25 g of an aqueous 13.1% strength by weight solution of acetone bisulfite was supplied to the reactor by way of separate feeds. The 600C were maintained for 1 hour. The batch was then cooled to room temperature and its pH adjusted to 9.1 using 10% strength by weight sodium hydroxide solution. The resulting dispersion was free from coagulum and had a solids content of 59.8% by weight. The weight-average particle diameter of the polymer was 275 nm.

Initiator solution: Monomer emulsion: 2.38 g of sodium peroxodisulfate 70.00 g of deionized water 227.73 g of deionized water 21.11 g of emulsifier solution 1 47.50 g of emulsifier solution 2 418.48 g of methyl methacrylate 512.53 g of butyl acrylate 19.00 g of methacrylic acid 45% strength by weight solution of sodium (dodecylsulfonylphenoxy)benzenesulfonate (Dowfax®2Al from Dow Chemicals) in water 30% strength by weight solution of the sodium salt of a sulfuric monoester mixture of alkyl-Clo-C 16 -ethoxylate (mean degree of EO of 30) in water (Disponil®FES 77 from R6hm GmbH).

Emulsifier solution 1: Emulsifier solution 2: Comparison Dispersion CD2 In the manner described for CD1, a comparison dispersion CD2 with a different monomer composition was prepared.

Following the polymerization reaction, the pH was adjusted to 7.2 using 10% strength by weight sodium hydroxide solution.

The resulting dispersion was free from coagulum and had a solids content of 60.5% by weight. The average diameter of the polymer particles was 269 nm.

Monomer emulsion: 227.73 g of water 21.11 g of emulsifier solution 1 47.50 g of emulsifier solution 2 356.25 g of methyl methacrylate 502.55 g of n-butyl acrylate 19.00 g of methacrylic acid 72.20 g of a 25% strength by weight solution of N-(2-methacryloxyethyl)imidazolidin- 2-one in methyl methacrylate.

Dispersion D1 In the manner described for CD1, the dispersion D1 of the invention was prepared.

Following the polymerization, the pH was adjusted to 9.1 using 10% strength by weight sodium hydroxide solution. The resulting dispersion was free from coagulum and had a solids content of 59.9% by weight. The average diameter of the polymer particles was 267 nm.

Monomer emulsion: 227.73 g of deionized water 21.11 g of emulsifier solution 1 47.50 g of emulsifier solution 2 410.40 g of methyl methacrylate 502.55 g of n-butyl acrylate 19.00 g of methacrylic acid 18.05 g of diacetoneacrylamide 18.05 g of diacetoneacrylamide ,1 22 Formulation Fl (in accordance with the invention) 0.3 g of adipic dihydrazide by weight, based on the polymer) was added to 100 g of the aqueous polymer dispersion D1, with thorough stirring.

Formulation F2 (in accordance with the invention) In the same way as for formulation Fl, 0.6 g of adipic dihydrazide was added to 100 g of the polymer dispersion D1 by weight based on the polymer).

II. Preparing the emulsion paints of the invention A vessel was charged with the following constituents: 105.60 g 2.00 g 0.80 g 1.00 g 3.40 g 1.70 g 3.40 g 10.10 g 10.10 g 190.10 g 181.60 g 50.70 g of water of thickener 1 of 2-amino-2-methylpropanol with 5% water of dispersant 2 of tetrapotassium pyrophosphate in water, by weight of commercial biocide 3 of commercial defoamer 4 of propylene glycol of dipropylene glycol n-butyl ether of titanium dioxide pigment 5 of feldspar 6 of calcined kaolin 7 The constituents were mixed for 20 minutes in a high-speed disperser. Then the following constituents were added with stirring: 266.01 g 2.50 g 11.80 g 159.00 g of dispersion or formulation from I (approximately 60% by weight); see Table 1 of commercial defoamer 4 of commercial thickener 8 of water 23 The performance properties of the emulsion paints are summarized in Table 1.

1) Hydroxyethylcellulose having a viscosity of 30 Pas (determined as a 2% strength solution in water at 25 oC); Natrosol® 250 HR from Hercules GmbH, DUsseldorf 2) 30% strength by weight aqueous solution of an ammonium polyacrylate; Pigmentverteiler (pigment dispersant) A from BASF AG, Ludwigshafen 3) Proxel®GXL from Zeneca GmbH, Frankfurt 4) Foammaster®S from Henkel KGaA, DUsseldorf Kronos®2101 from Kronos, Houston, Texas 6) Minex®4 from Unimin Speciality Minerals Inc., Elco, Illinois, average particle size 7.5 pm 7) Icecap® from Burgess Pigment Co., Sandersville, Georgia 8) 20% strength by weight solution of a polyurethane associated thickener, Acrysol RM 2020 from Rohm and Haas Deutschland GmbH, Frankfurt III. Determining the performance properties (Examples Cl C3, 1, 2) 1. Abrasion resistance The abrasion resistance was determined in accordance with ASTM D2486 using a Gardner abrasion machine and a standardized abrasive medium (abrasive type SC-2).

The emulsion paints from II were applied with a box-type doctor blade (gap height 175 pm, 7 MIL) to Leneta sheets.

The sheets were then dried in a climatically controlled chamber for 14 days under standard climatic conditions (230C, 50% relative atmospheric humidity). The dry thickness was about 50 pm.

For each emulsion paint the abrasion test was carried out on 3 sheets. For this purpose, metal strips 250 pm thick were placed underneath the center of the sheets. Then abrasive paste was applied and abrasion was carried out with a nylon brush until the coating had been abraded right through at the point lying above the metal. The parameter indicated is the number of double strokes N required to bring about this complete abrasion at one P1 24 point. It is stated as the average of two values which deviate by less than 2. Blocking resistance The blocking resistance was determined in accordance with ASTM D4946. For this purpose the emulsion paints from II were applied with a box-type doctor blade (3 MIL; gap height 75 CAm) to Leneta sheets. The sheets were then dried for 24 hours under standard climatic conditions.

The dried and coated sheets were subsequently cut into 3.8 cm squares. The squares were placed on top of one another with the coated sides facing and inserted between two glass plates. A weight of 2 kg was placed on top of these glass plates. This arrangement was stored at 500C for 24 hours. The behavior of the coating on removal of the sheets from one another was then examined. The results were based on a rating scale of 0 to 0 75 to 100% tearing of the coating 1 50 to 75% tearing 2 25 to 50% tearing 3 5 to 25% tearing 4 very tacky: 0 to 5% tearing moderate tack 6 slight tack 7 slight to very slight tack 8 extremely slight tack 9 barely any tack no tack 3. Wet adhesion The wet adhesion was determined as follows: in a first step, the Leneta sheets were coated with a solventborne alkyd resin lacquer (Glasurit EA, high-gloss lacquer from BASF deco GmbH, Cologne) using a box-type doctor blade (gap height 180 pm). The sheets were dried for 24 hours in a standard-climate chamber and then in an oven at 500C for 14 days. The emulsion paints from II were then applied to the resin-coated Leneta sheets as a second coating, using an applicator (gap height 250 pm, 10 MIL).

The resulting sheets were dried under standard climatic conditions for 3 days. Three test specimens were cut out from each sheet. Each test specimen was scribed horizontally using a razor blade, and then a freeze/thaw test was conducted. For this, the test specimens were wetted with water and stored in a deep freeze at -200C for 16 hours. This procedure was repeated twice. The samples were subsequently allowed to warm to room temperature, and then wetted with water again for minutes. The adhesion of the coating at the scribe mark was subsequently assessed by scratching with the fingernail, on the basis of a rating scale of 0 to where 0 is optimum adhesion and 5 denotes no adhesion (flawless removal). The ratings 1 to 4 denote intermediate values.

The results are summarized in Table 1.

Table 1: S" 20 Exam- Dis- Funct- Cross- MFT Blocking Wet Abrasion ple per- ional linker 2) resi- adhesion resision monomer 1) stance stance by wt.] C CD1 0 5 0 4-5 1350 25 C2 CD2 UMA 3 0 6 0 1 1200 (1.9) C3 D1 DAAM 0 5 1 4-5 1450 (1.9 S* 1 F1 DAAM 0.5 by 6 2 1-2 1750 30 30 wt.

2 F2 DAAM 1.0 7 4 1 2000 1 by wt.

1) Crosslinker adipic dihydrazide 2) MFT minimum film-forming temperature 3) UMA ureidomethacrylate (N-methacryloxyethylimidazolidin-2one) 4) DAAM diacetoneacrylamide (CH 2

=CH-CO-NH-C(CH

3 2

-CH

2

-CO-CH

3 "Comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims (8)

1. An emulsion paint comprising i. as binder a formulation comprising as component A at least one aqueous polymer dispersion whose polymer P possesses functional groups of the formula O C-R 1 where R 1 is hydrogen, alkyl, cycloalkyl, aryl or aralkyl and X is attached to a carbon of the polymer chain and is a single bond, alkylene, arylene, -R 2 -O-R 3 -R 2 -Z-0-R 3 -R 2 -Z-CH 2 -R 3 -R 2 -Z-N(R 4 )-R 3 R 2 -O-Z-O-R 3 -R 2 -O-Z-CH 2 -R 3 -R 2 -O-Z-N(R 4 -R 3 -R 2 -N(R 5 )-Z-O-R 3 -R 2 -N(R 5 )-Z-CH 2 -R 3 or -R 2 -N(R 5 )-Z-N(R 4 )-R 3 where -R 2 is a single bond, alkylene, oxyalkylene, polyoxyalkylene or arylene and is attached to the polymer, -R 3 is C 1 -C 4 -alkylene or arylene, Z is SO 2 or C=O, and R 4 and R 5 independently are hydrogen, alkyl, cycloalkyl, aryl, aralkyl or -R 3 -(CO)-R 1 where R 1 and R 3 are as defined above and as component B comprises at least one compound having at least two NH 2 groups that are reactive toward the carbonyl groups of the polymer of component A; 40 ii. at least one inorganic pigment, iii.if desired, one or more inorganic fillers, and iv. customary auxiliaries, 27 where R 6 is hydrogen or methyl, R 7 is hydrogen, alkyl or -X-(CO)-R 1 and X and R 1 are as defined previously with or without further monomers, the monomers b making up from 0.1 to 25% by weight of the overall monomer amount, and as component B comprises at least one compound having at least two NH 2 groups that are reactive toward the carbonyl groups of the polymer of component A; ii. at least one inorganic pigment, iii.if desired, one or more inorganic fillers, and iv. customary auxiliaries, the emulsion point comprising no organotin compounds and the ratio of inorganic constituents to polymer P being reflected in a characteristic pigment volume concentration of S'ooo 20

2. An emulsion paint as claimed in claim 1, wherein component B is a di- or polyhydrazide of a di- or polycarboxylic acid.

3. An emulsion paint as claimed in claim 1, where the monomers b are selected from methyl vinyl ketone, ethyl vinyl ketone, o isobutyl vinyl ketone, acrolein, methacrolein, formylstyrene, 3-acryloxy-2,2-dimethylpropanal, phenyl vinyl ketone, 0.0: 30 diacetoneacrylamide and diacetonemethacrylamide.

4. An emulsion paint as claimed in either of claims 2 and 3, where the monomers a comprise at least two different monomers al and a2 selected from vinylaromatic monomers, from the esters of acrylic acid with Ci-Cl2-alkanols, from the esters of methacrylic acid with C 1 -C 12 -alkanols, from the vinyl esters of aliphatic C 1 -C 12 monocarboxylic acids, from ethylene and from vinyl chloride.

5. An emulsion paint as claimed in any one of claims 2 to 4, where the polymers P comprise from 0.1 to 5% by weight of monomers c selected from monomers cl which have an acid group and from the amides, N-alkylolamides and hydroxyalkyl esters of ethylenically unsaturated C 3 -C carboxylic acids (monomers c2). 28

6. An emulsion paint as claimed in claim 5, wherein the polymer P of component A is composed essentially of S from 25 to 70% by weight of at least one ethylenically unsaturated monomer al whose homopolymer has a glass transition temperature Tg of 300C, S from 25 to 70% by weight of at least one ethylenically unsaturated monomer a2 whose homopolymer has a glass transition temperature Tg of 20 0 C, from 0.1 to 5% by weight of at least one monomer b, and from 0.1 to 5% by weight of at least one ethylenically unsaturated monomer c, the overall amount of the monomers al, a2, b and c adding up to 100% by weight.

7. An emulsion paint as claimed in any one of the preceding claims 20 comprising, based on the solids content of the emulsion paint, i) from 5 to 60% by weight of binder i as set forth in any of claims 1 to 8 (calculated as solids), ii) from 5 to 60% by weight of at least one inorganic oe. pigment, iii) from 0 to 85% by weight of inorganic fillers, and iv) from 0.1 to 40% by weight of customary auxiliaries, Sthe proportions by weight of the constituents i) to iv) adding up to 100% by weight.

8. The use of a binder as defined in any one of claims 1 to 6 for improving the wet abrasion resistance of polymer-bound emulsion paints. DATED this 3 0 th day of October 2001 WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P17392AU00 LCG:BJD:SLB