Field of the Invention

The present invention relates to compositions and methods useful in forming a film on a substrate, which film has particular utility as a binder for an

ink or varnish.

Background of the Invention

U.S. Patent No. 4,690,712 (Janusz) relates to the preparation of publication gravure inks by the neutralization of an amine-reactive polyamide with a metal resinate. The products are made in toluene or mixtures of aromatic and aliphatic solvents and are reported to exhibit improved holdout (non-penetration)

on porous paper stock. This reference pertains only to solvent based systems which employ metal resinates as one of the ingredients (reactants).

European Patent Publication No. 359,129, published March 21 , 1990, discloses that commercial polyamides are modified with carboxyl containing materials, such as maleated, fumarated, itaconated and acrylated rosins; polyvinyl maleic acid copolymers, such as styrene-maleic resins and polybasic acids, such as citric, tartaric, etc. These carboxylated polyamide products were manufactured by fusion of the components over extended periods of time at temperatures of 180°C-250°C. The new resins had different physical and chemical properties from their original components, although retaining some of the desirable characteristics of parent polyamides, such as flexibility, high gloss,

^* and adhesion to a variety of surfaces, especially plastic films.

European Patent Publication No. 363,698, published April 18, 1990, discloses that carboxylated polyamide products are obtained by fusion of polyamides with carboxylated rosins and styrene-acrylic poiyelectrolytes for extended periods of time at temperatures 180°C-250°C. It is disclosed that the products of these publications contained no toxic volatiles or residual monomers and could be dissolved in organic solvents for applications as non-aqueous coatings and ink vehicles. In addition they could be rendered waterbome by neutralization with alkali or amines.

U.S. Patent N. 5,180,782 (Stone et al.) discloses compositions and methods of producing water soluble resins and particularly of producing water-soluble polyamide-acrylic, polyamide-styrene-acrylic or polyamide-styrene-maleic resins. It is disclosed that such resins are especially

useful as vehicles in aqueous inks and coatings and as pigment dispersants. The process involves simply heating an aqueous solution of carboxylated polyamide or polyamides containing free primary amine functionality with an aqueous solution of styrene-acrylic, styrene-maleic or all-acrylic resin until the two resins are compatible.

Summary of the Invention

This invention relates to a composition of matter comprising an aqueous mixture of a major amount of a polymer comprised of an aromatic monomer and an acid monomer, said polymer having a glass transition temperature above room temperature, and a minor amount of a fatty material, a major proportion of

^* said fatty material being carboxylates of fatty acids selected from the group consisting of mono- and polybasic acids having fatty aliphatic groups containing at least about 8 carbon atoms. This invention also relates to pigment dispersions and/or printing inks comprising a pigment and a mixture as described above in an aqueous medium.

This invention also relates to a method of coating a substrate comprising contacting a surface of a substrate with a composition comprising a mixture as described above and drying said surface to form a film of said composition in contact with said surface.

With respect to certain embodiments, the polymer described above is produced by the process of polymerizing monomers consisting essentially of:

(i) an aromatic monomer having the formula CH ₂ =C(R ¹ )(R ² ) wherein R ¹ is an aromatic group having from 6 to 10 carbon atoms, and R ² is hydrogen,

(ii) an aromatic monomer having the formula CH ₂ =C(R ³ )(R ⁴ ) wherein R ³ is an aromatic group having from 6 to 10 carbon atoms, and R" is lower (e.g. C _r C ₄ ) alkyl, preferably methyl, and

(iii) an acid monomer having the formula CH ₂ =C(C(O)OH)(R ⁵ ) wherein R ⁵ is hydrogen or methyl, or mixtures thereof.

In typical embodiments, the monomers consist essentially of one or more of said aromatic monomers having an unsubstituted ethylenic group in an amount of from about 20% to about 40% by weight, one or more of said aromatic monomers having an alkyl-substituted ethylenic group in an amount of from about 30% to about 50% by weight, and one or more of said acid monomers in an amount of from about 20% to about 40% by weight. Preferred polymers are

-based on styrene as the aromatic monomer with an unsubstituted ethylenic group, alpha-methylstyrene as the aromatic monomer with an alkyl-substituted ethylenic group and acrylic acid as the acid monomer. The polymer typically has a molecular weight (e.g. weight average) of from about 1 ,000 to about 20,000.

Detailed Description of the Invention

In certain aspects, this invention relates to mixtures of certain polymers and certain fatty materials in an aqueous medium. In still other aspects, this invention also relates to ink compositions comprised of a pigment and to such a mixture as the binder for the pigment. Further, this invention relates to a method of coating a substrate which employs such mixtures and to the coatings produced thereby. Each of these aspects will be addressed in turn below.

The polymers used in the mixtures of this invention are comprised of an aromatic monomer and an acid monomer, the specific types and amounts of the monomer yielding a polymer having a glass transition temperature (T _g ) above room temperature (i.e. greater than about 25°C). Glass transition temperatures can be measured by a variety of means as described in Encyclopedia of Polvmer

Science and Engineering, vol. 3, pp. 308-312 (John Wiley & Sons, Inc., N.Y.,

N.Y., 1985), two common means being by differential scanning calorimetry or by dynamic mechanical analysis. Preferred polymers will have a T _g of greater than about 40°C, typically greater than about 50°C, and more typically greater than about 60°C, and even more typically from about 80°C to about 100°C. Such a polymer will, thus, possess a hardness that is useful in a coating, e.g. for

- resistance of the coating to abrasion. However, such a polymer will also tend to be brittle, which brittleness can cause the coating to crack when subjected to impact forces. Thus, a material which can impart a degree of flexibility to the coating is needed to ensure that the coating has impact resistance as well as abrasion resistance. Examples of such polymers include the styrene-maleic anhydride polymers, e.g. SMA® 1000H, a 40% by weight aqueous ammoniacal solution of a styrene-maleic anhydride copolymer which is a trademark product of ELF Atochem, North America, Inc. The polymers preferred for use in this invention can be generally characterized as terpolymers, i.e. they have repeating units derived from at least three different monomers: an aromatic monomer having an unsubstituted ethylenic group, an aromatic monomer having an alkyl-substituted ethylenic group, and an acid monomer. Thus, the starting materials for preparing these

polymers of this invention are an ethylenically unsaturated aromatic compound wherein the ethylenic group is unsubstituted, an ethylenically unsaturated aromatic compound wherein the ethylenic group bears an alkyl group as a substituent, and an ethylenically unsaturated acid compound. The monomeric unit A is derived from an ethylenically unsaturated aromatic compound wherein the ethylenic group is unsubstituted. Examples of the ethylenically unsaturated aromatic compounds include monovinyl aromatic hydrocarbons containing from 8 to 12 carbon atoms and halogenated derivatives thereof having halo-substituted aromatic moieties. Specific examples include styrene, vinyl toluene (e.g. a 60/40 mixture by weight of meta-methylstyrene and para-methylstyrene), meta-methylstyrene, para-methylstyrene, para-ethylstyrene,

- para-n-propylstyrene, para-isopropylstyrene, para-tert-butylstyrene, ortho- chlorostyrene, para-chlorostyrene, and tert-butyl styrene. Certain vinyl aromatic compounds are discussed in "Styrene Polymers", Encyclopedia of Polvmer Science and Engineering, vol. 16, pp. 1-21 (John Wiley & Sons, Inc., N.Y., N.Y.,

1989), the disclosure of which is incorporated by reference herein.

The monomeric unit B is derived from an ethylenically unsaturated aromatic compound wherein one of the carbon atoms which make up ethylenic unsaturation bears an alkyl group. Examples of such compounds include alpha-methylstyrene, alpha-methyl-meta-methylstyrene, alpha-methyl-para- methylstyrene, alpha-methyl-ortho-chlorostyrene, alpha-methyl-para- chlorostyrene, alpha-ethylstyrene, alpha-ethyl-meta-methylstyrene, alpha-ethyl- para-methylstyrene, alpha-ethyl-ortho-chlorostyrene, alpha-ethyl-para- chlorostyrene, beta-methylstyrene, beta-methyl-meta-methylstyrene, beta-

methyl-para-methyistyrene, beta-methyl-ortho-chlorostyrene, beta-methyl-pa ra- chlorostyrene, beta-ethylstyrene, beta-ethyl-meta-methylstyrene, beta-ethyl-para- methylstyrene, beta-ethyl-ortho-chlorostyrene, and beta-ethyl-para-chlorostyrene. The monomeric unit C is derived from an ethylenically unsaturated acid monomer. Examples of alpha, beta-ethylenically unsaturated carboxylic acids which may also be useful as comonomers to prepare the polymer of the invention include acrylic acid, beta-acryloxypropionic acid and higher oligomers of acrylic acid and mixtures thereof, methacrylic acid, itaconic acid, aconitic acid, crotonic acid, citraconic acid, maleic acid, fumaric acid, alpha-chloroacrylic acid, cinnamic acid, mesaconic acid and mixtures thereof. Preferred examples are acrylic acid and methacrylic acid. Such acids are described in "Acrylic and Methacrylic Acid

-Polymers", Encyclopedia of Polvmer Science and Engineering, vol. 1 , pp. 211-

234 (John Wiley & Sons, Inc., N.Y., N.Y., 1985), the disclosure of which is incorporated herein by reference. Further examples of acid monomers that may be useful include the partial esters of unsaturated aliphatic dicarboxylic acids and particularly the alkyl half esters of such acids. Examples of such partial esters are the alkyl half esters of itaconic acid, fumaric acid and maleic acid wherein the alkyl group contains 1 to 6 carbon atoms. Representative members of this group of compounds include methyl acid itaconic, butyl acid itaconic, ethyl acid fumarate, butyl acid fumarate, and methyl acid maleate. These acid monomers generally have greater molecular bulk than the preferred monomer, acrylic acid, and thus, may have less hydrophilic character than the preferred monomer, acrylic acid.

The amount of the A monomeric unit will generally be a minor amount, e.g. from about 20% to about 40% by weight of the polymer, preferably from about 25% to about 35%. The amount of the B monomeric unit will typically be a minor amount, e.g. from about 30% to about 50% by weight of the polymer, more typically from about 35% to about 45%. The amount of the C monomeric unit will typically be a minor amount, e.g. from about 20% to about 40% by weight of the polymer, more typically from about 25% to about 35%.

While the preferred polymers are prepared without additional comonomers, other monoethylenically unsaturated polymerizable monomers useful in minor proportion (e.g. less than 10% by weight of the total monomer composition) as comonomers with the aromatic and acid monomers may be

- useful in preparing the polymers of this invention. Examples of other monomers include the vinylidene halides, vinyl halides, acrylonitrile, methacrylonitrile, vinyl esters such as vinyl formate, vinyl acetate and vinyl propionate, and mixtures of ethylene and such vinyl esters, acrylic and methacrylic acid esters of alcohol ethers such as diethylene glycol monoethyl or monobutyl ether methacrylate, 0,-0, ₀ alkyl esters of beta- acryloxypropionic acid and higher oligomers of acrylic acid, mixtures of ethylene and other alkylolefins such as propylene, butylene, pentene and the like, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, vinyl 2-methoxyethyl ether, vinyl 2-chloroethyl ether and the like, hydroxy functional vinyl monomers such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl methacrylate, butanediol acrylate,

3-chloro-2-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate.

In addition to mono-ethylenically unsaturated monomers, the monomers from which the polymer is prepared may also be comprised of an ethylenically unsaturated monomer having at least two sites of ethylenic unsaturation, i.e. a di- or higher multi-ethylenically unsaturated monomer. Examples of multiethylenic monomers include alkenyl acrylates or methacrylates (e.g. allyl methacrylate), di-alkenyl arenes, particularly di-alkenyl benzenes (e.g. divinyl benzene), di-alkenyl ethers (e.g. ethylene glycol di-allyl ether and pentaerythritol di-allyl ether), di-acrylamides (e.g. methylene-bis-acrylamide, trimethylene-bis- acrylamide, hexamethylene-bis-acrylamide, N,N'-diacryloylpiperazine, m- phenylene-bis-acrylamide, and p-phenylene-bisacrylamide), di- or higher multi- acrylates (e.g. diethylene glycol diacrylate, propylene glycol dimethacrylate,

- ethylene glycol dimethacrylate, polyethylene glycol diacrylate, bis(4-acryloxypolyethoxyphenyl)-propane, 1 ,3-butylene glycol dimethacrylate,

1 ,5-pentanediol diacrylate, neopentyl glycol diacrylate, 1 ,6-hexanediol diacrylate, and polypropylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and triethylene glycol dimethacrylate). The amount of the multiethylenic monomers will be a minor amount, typically from about 0.1% to about 3% by weight of total monomers, because the polymer should not be so highly crosslinked that it is rendered insoluble.

While it is thus conceivable that the polymer will contain monomeric units derived from monomers other than the aromatic monomer and the acid monomer, in preferred embodiments, the polymer is prepared by polymerization of monomers consisting of:

(a) from about 10% to about 60%, more typically from about 20% to about 40%, and preferably from about 25% to about 35%, by weight based on the total weight of monomers, of an ethylenically unsaturated aromatic monomer having less than twelve carbon atoms and an unsubstituted ethylenic unsaturation, said monomer preferably being styrene,

(b) from about 20% to about 70%, more typically from about 30% to about 50%, and preferably from about 35% to about 45%, by weight based on the total weight of monomers, of an ethylenically unsaturated aromatic monomer having less than twelve carbon atoms and an alkyl-substituted ethylenic unsaturation, said monomer preferably being alpha-methyl styrene, and

(c) from about 10% to about 60%, more typically from about 20% to about -40%, and preferably from about 25% to about 35%, by weight based on the total weight of monomers of an ethylenically unsaturated carboxylic acid having less than six carbon atoms, preferably acrylic acid and/or methacrylic acid. In general, the polymer will have a molecular weight (e.g. weight average) of from about 1 ,000 to about 20,000, typically from about 1 ,500 to about 10,000, and more typically from about 2,000 to about 8,500. The acid value (expressed as mg of KOH per gram of polymer) of the polymer should be less than about 250, typically about 110 to about 240, more typically from about 190 to about 220. These typical acid values are based on polymers in which acrylic acid is the acid monomer and the acid value of other polymers, given the same mole ratio of acid monomer to other monomers will depend, of course, on the molecular weight of the particular acid monomer used.

The fatty acids are saturated and/or unsaturated aliphatic monocarboxylic or polycarboxylic acids containing 8 to 24 carbon atoms or saturated or unsaturated hydroxycarboxylic acids containing 8 to 24 carbon atoms or ketofatty acids containing 12 to 22 carbon atoms. The carboxylic acids and/or hydroxycarboxylic acids may be of natural and/or synthetic origin. Examples of suitable monocarboxylic acids are caprylic acid, 2-ethylhexanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, elaeostearic acid, ricinoleic acid, arachic acid, gadoleic acid, behenic acid, erucic acid and brassidic acid and the technical mixtures thereof obtained, for example, in the pressure hydrolysis of natural fats and oils, in the oxidation of aldehydes

- from Roelen's oxo synthesis, or as monomer fraction in the dimerization of unsaturated fatty acids. Examples of suitable hydroxymonocarboxylic acids are ricinoleic acid and 12-hydroxystearic acid. In a particularly preferred embodiment, the fatty acid is derived from technical mixtures of the fatty acids mentioned which are obtainable in the form of the technical mixtures typically encountered in oleochemistry after the pressure hydrolysis of oils and fats of animal or vegetable origin, such as coconut oil, palm kernel oil, sunflower oil, rape oil, rapeseed oil and coriander oil and beef tallow. However, the fatty acid may also contain a branched fatty acid residue, for example the residue of 2- ethyl hexanoic acid, isopalmitic acid or isostearic acid. The fatty acid may also be a ketofatty acid containing 12 to 22 carbon atoms. Typical and preferred representatives of these ketofatty acids are the various isomers of ketostearic acid which are described in Acta Chemica Scandinavica vol. 6, pp. 1157 to 1174

(published by the Chemical Societies of Denmark, Finland, Norway and Sweden, Copenhagen, Denmark, 1952). Of these isomeric ketostearic acids, 4-, 9(10)and 12-ketostearic acids are particularly preferred because they can be obtained particularly easily from natural raw materials. Preferred fatty acids are mixtures obtained from natural sources, e.g. palm oil, palm kernel oil, coconut oil, rapeseed oil (from old high-erucic acid plants or from new low-erucic acid plants, a.k.a. canola oil), sunflower oil (from old low- oleic plants or from new high-oleic plants), castor oil, soybean oil, cottonseed oil, peanut oil, olive oil, olive kernel oil, coriander oil, castor oil, meadowfoam oil, chaulmoogra oil, tea seed oil, linseed oil, beef tallow, lard, fish oil and the like.

Naturally occurring fatty acids typically are present as triglycerides of mixtures of fatty acids wherein all fatty acids have an even number of carbon atoms and a major portion by weight of the acids have from about 12 to 18 carbon atoms and are saturated or mono-, di-, or tri-unsaturated. Preferred polycarboxylic acids having a higher alkylene chain are described in Encyclopedia of Polvmer Science and Technology, vol. 11 , pp.476- 489, (John Wiley & Sons, Inc. N.Y., N.Y., 1988), the disclosure of which is incorporated herein by reference. Preferred polycarboxylic acids are dimer or trimer acids (produced by the dimerization or trimerization of fatty acids, e.g. dimerization of oleic acid results in a fatty alkylene group which is a divalent hydrocarbon having 36 carbon atoms and trimerization results in a fatty group having 54 carbon atoms). Dimer acids are also described in detail in U.S. Patent No. 5,138,027 (Van Beek), the disclosure of which is incorporated herein by reference. Diacids also include the C9 azaleic acid (produced by the ozonolysis

of oleic acid), C13 tridecanedioc acid (produced by the ozonolysis of erucic acid), C19 diacid (produced by the hydroformylation of oleic acid with carbon monoxide) and C21 diacid (produced by the reaction of tall oil fatty acid with acrylic acid). The amount of the fatty material will, in relation to the amount of the polymer, be a minor amount, i.e. the amount of the fatty material will be less than the amount of the polymer. The amount of fatty material will typically range from about 5% to about 35%, more typically from about 10% to about 30%, and even more typically from about 15% to about 25%, by weight of the sum of the weights of the polymer and the fatty material. The precise amount of the fatty material in any given mixture is preferably selected in relation to the hardness of the

- polymer to achieve the degree of flexibility desired in a dried coating of the mixture of polymer and fatty material. The degree of flexibility of the coating can be determined by application of the coating to a flexible substrate which is then moderately flexed. The coating is deemed flexible if flexure does not cause visible cracks in the coating.

At least a portion of the acid groups of both the polymer and the fatty material in the mixture will be in the form of a carboxylate anion rather than the free acid group. Thus, either the polymer or the fatty material, or both, will be at least partially neutralized before or after the two components are mixed. As examples of bases that can be used to neutralize the acid groups, there can be mentioned sodium hydroxide, potassium carbonate, soda ash, etc. Preferably, however, the base used to neutralize at least a portion of the acid groups is ammonia or a volatile organic amine. Typically, only ammonia is used to

neutralize the acid groups to avoid any contribution to the volatile organic content of the mixture, but examples of suitable organic amines that can be used in place of or with ammonia include primary, secondary, and tertiary amines which can act as a base to salt polymer. Specific examples of organic amines are the dialkyl aminoalkanols such as 2-(N,N-dimethylamino)ethanol and 2-(N,N-diethylamino)ethanol.

The ammonia or organic amine is preferably present in the aqueous solution in an amount sufficient to neutralize all of the acids groups of the polymer and the fatty material, i.e., the amount of ammonia or organic amine is stoichiometrically equivalent to or greater than the acid value of the polymer and the fatty material. A large excess of organic amine should be avoided because - retention of the organic amine in the dried coating may adversely affect the water resistance of the coating.

The mixture will be an aqueous mixture and while water will typically be the component present in the greatest amount by weight, the precise amount of water may vary broadly. Typically, the mixture will contain water in an amount of from about 40% to about 80% by weight, more typically from about 50% to about 70% by weight, and most typically from about 55% to about 65% by weight, of the aqueous composition. The mixture will typically be essentially free of organic solvents, e.g. alcohol solvents such as the short chain aliphatic alcohols having from 2 to 4 carbon atoms, e.g. the lower alkanols, ethanol, n-propanol, isopropanol and n-butanol. These solvents can contribute to the volatile organic content (a.k.a.

VOC) of the mixture and any ink prepared therefrom, which has environmental disadvantages.

One of the ingredients of the inks of this invention is a pigment or colorant.

The generic term pigment includes both colorant pigments and opacifying pigments. The term "colorant pigment" is specifically used in this specification to refer to both pigments and dyes which impart a distinct color to the composition.

The pigment may be a colorant pigment, i.e. the pigment will impart a color to the pigment dispersion, to a printing ink prepared therefrom, and to the surface of a substrate printed with such a printing ink. The colorant pigments useful in this invention will typically include black, organic red, organic yellow, as

'well as violet, orange, green, and brown. Useful pigments include for instance calcium lithol (red), diarylide yellow, raw sienna and burnt sienna, raw and burnt umber, carbon black, lampblack. The pigment may be an opacifying pigment. Opacifying pigments are generally pigments having a refractive index of at least about 1.8. Typical white opacifying pigments include rutile and anatase titanium dioxide. The ink may contain non-opacifying filler or extender pigments often referred to in the art as inerts and include clays, such as kaolinite clays, silica, talc, mica, barytes, calcium carbonate, and other conventional filler pigments. All filler or extender pigments have fairly low refractive indices and can be described generally as pigments other than opacifying pigments.

A pigment dispersion may be prepared as follows. The pigment is mixed with an aqueous mixture of the polymer and fatty material and, at a properly

adjusted viscosity, dispersed thereinto with a ball mill, sand mill, high-shear fluid flow mill, Cowles Dissolver, Katy Mill or the like. Because the fatty material may tend to foam, a defoaming agent may be added to the mixture. The process of dispersing causes agglomerates of the pigment particles to deagglomerate and the polymer may cause the deagglomerated particles of pigment to be wetted with the aqueous solution. This wetting thus tends to inhibit the reagglomeration of the pigment particles. Alternatively, a pigment that is pre-dispersed using a separate dispersing agent, e.g. Nopcosperse 44, available from Henkel Corporation, Ambler, Pennsylvania, can also be used. This invention also relates to a method of coating a substrate comprising contacting a surface of a substrate with a composition comprising a mixture of

-this invention and drying said surface to form a film of said polymer in contact with said surface. Methods of coating substrates, e.g. roll coating and spray coating, are described in "Coating Methods", Encyclopedia of Polvmer Science and Engineering, vol. 3, pp. 553-575 (John Wiley & Sons, Inc., N.Y., N.Y., 1985), the disclosure of which is incorporated herein by reference.

The printing processes most advantageously used with the inks or varnishes of this invention are the fiexographic and/or gravure printing processes. One characteristic of such printing processes, is that the aqueous dispersion of ink or varnish (a varnish being a printing vehicle that is un- pigmented and which is useful, for example, as an overprint) is supplied to said surface by a hydrophilic cylindrical transfer roll. Printing processes are described by T. Sulzberg et al., "Printing Ink Vehicles", Encyclopedia of Polymer Science and Engineering, vol. 13, pp. 368-398 (John Wiley & Sons, Inc., N.Y, N.Y., 1988),

the disclosure of which is incorporated herein by reference. Thus, this invention relates to a method of printing comprising applying a first portion of an aqueous mixture of this invention to a first essentially impervious printing surface, said surface having recesses therein which define a resolvable image, contacting said surface with a printable substrate, and repeating said applying and said contacting with a second portion of said aqueous mixture and a second printable surface. This method may be a letterpress printing method (wherein said recesses define raised portions of the surface which carry the aqueous dispersion to the substrate, e.g. flexography) or a gravure printing method (wherein said recesses carry the aqueous dispersion to the substrate). In fiexographic printing in particular, an aqueous mixture of this invention is applied

-to a flexible plate mounted on a plate cylinder. The flexible plate is then contacted with a printable substrate by rotation of the plate cylinder. In preferred embodiments, the aqueous mixture is applied to the flexible plate with a hydrophilic cylindrical transfer roll which is rotated to successively take up and then apply successive portions of the aqueous dispersion.

The following examples will serve to further illustrate the invention, but should not be construed to limit the invention, unless expressly set forth in the appended claims. All parts, percentages, and ratios are by weight unless otherwise indicated in context.

EXAMPLES Example 1

A solution of 40% by weight of styrenated acrylic resin (available as G- CRYL ® 399 from Henkel Corp., Ambler, Pennsylvania) in an amount of 37.64 parts by weight was mixed with 4 parts by weight of linoleic acid (available as EMERSOL® 315 from Henkel Corp., Cincinnati, Ohio), 5 parts by weight of deionized water and 1 part by weight of 28% by weight aqueous ammonia. G- CRYL 399 is described as a styrenated acrylic resin having an acid number of 215, Tg of 88°C, a weight average molecular weight of 4,900, and a softening point of 125°C. The resulting varnish was drawn down on an N2A Leneta chart with #10 Meyer Rod. The coating was allowed to dry. The film exhibited a water resistance at 3 minutes and 10 minutes of 9.5 and a 60° gloss of 93.7.

-Example 2

Example 1 was repeated, but a mixture of soy oil fatty acids (available as

EMERY® 610 Soya Fatty Acid, from Henkel Corporation, Cincinnati, Ohio) was substituted for the linoleic acid in the same amount (i.e. 4 parts by weight). The film exhibited a water resistance at 3 minutes and 10 minutes of 10 and a 60° gloss of 91.3.

Example 3

Example 1 was repeated, but a mixture of 66.7% by weight canola fatty acids and 33.3% by weight soya fatty acids (which mixtures yields a fatty acid distribution similar to the distribution of fatty acids in commercial tall oil fatty acid and is available as CS100 fatty acids, from Henkel Coφoration, Cincinnati, Ohio)

was substituted for the linoleic acid in the same amount (i.e. 4 parts by weight). The film exhibited a water resistance at 3 minutes and 10 minutes of 10 and a 60° gloss of 90.0.

Example 4

A mixture similar to the mixture of Example 1 was prepared, but employing tall oil fatty acids (Aliphat 44A) was substituted for the linoleic acid. The film exhibited a water resistance at 3 minutes and 10 minutes of 10 and 9.5 and a 60° gloss of 90.2.

Example 5

A mixture similar to the mixture of Example 1 was prepared, but employing C21 diacid (available as Diacid 550 from Westvaco, Charleston Heights, SC) was substituted for the linoleic acid. The film exhibited a water resistance at 3 minutes and 10 minutes of 6 and 4 (poor) and a 60° gloss of 90.2.

Example 6 A mixture similar to the mixture of Example 1 was prepared, but employing a dimer acid (available as VERSADYME 204 from Henkel Corporation, Ambler, Pennsylvania) was substituted for the linoleic acid. The film exhibited a water resistance at 3 minutes and 10 minutes of 10 and 8 and a 60° gloss of 89.7.

Example 7

A mixture similar to the mixture of Example 1 was prepared, but employing a trimer acid (available as VERSATRYME 213 from Henkel Coφoration, Ambler, Pennsylvania) was substituted for the linoleic acid. The film exhibited a water resistance at 3 minutes and 10 minutes of 7 and 6 and a 60° gloss of 93.7.