CZ20001205A3 - Latex composition resistant to abrasion - Google Patents

Abstract

The latex compositions comprise a first polymer prepared by polymerization from at least one carboxyl monomer or anhydride functional groups, and a second polymer, prepared by polymerization of carboxyl free monomers or anhydride functional groups, wherein at least one from polymers is prepared by polymerization from a monomer which is contains a nitrogen function. Coating composition said latex composition, water and pigment.

Description

The invention generally relates to latex polymers, and more particularly to abrasion-resistant latex polymers having enhanced wet adhesion characteristics.

BACKGROUND OF THE INVENTION

Latex paints are generally applied to substrates and then dried to form continuous films for both decorative and substrate protection purposes. If the coatings are fluid enough to be cast to form a continuous film of paint and dry at ambient temperature, then such coatings are often applied to interior or exterior building surfaces.

La.tex paints usually contain an organic polymeric binder, i.e. latex polymer, pigments and various coating additives. In dried coating films, the polymeric binder acts as a pigment binder and imparts adhesion of the dried coating film to the substrate. The pigments may be organic or inorganic and, in addition to durability and hardness, functionally contribute to opacity and coloration, although some coatings contain little or no opacifying pigments and are referred to as clear coatings. The production of paints involves the preparation of polymeric binder, mixing of constituent materials, grinding of pigments in a dispersing medium, and dilution to commercial standards.

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Latexes produced for building interior or exterior surfaces often need a wet adhesion property. Wet adhesion is usually tested by pouring a 0.18 mm thick latex paint film onto a glossy alkyd (oil based) film that has been allowed to dry for at least 3 weeks, but not more than 6 weeks. The latex coating is allowed to dry for 24 hours, then the film is cross-hatched, placed in water for 30 minutes, then removed from the water and placed in a scouring machine. The cross-hatched section is scrubbed for 500 cycles using a 5% lava-soap solution and a standard scrub brush. Optimal wet adhesion values are obtained when no film of paint is removed during the test. The percentage of film remaining is recorded. This property essentially allows the paint to adhere to surfaces previously coated with alkyd paints.

One of the latex polymers commonly used in latex paints that require wet adhesion comprises acrylic or styrene-acrylic monomers. There are a number of methods for producing latexes from these types of monomers. One of these methods utilizes a general reaction scheme to form two-stage latices. The first step consists of monomers and chain transfer agents polymerized in the presence of water and optionally wetting agents to obtain a polymeric latex which is water-soluble or slightly water-soluble. In the second stage, polymerization is then carried out in the presence of the first stage to form a more hydrophobic polymer. The resulting polymer is referred to in the art as a composite latex with an internal hydrophobic second stage and an external first stage that is water soluble or sparingly soluble or swellable. Alternatively, the water-soluble or swellable polymer is added simultaneously

Β βββ with a second degree. EP 0 587 333 A2 discloses water-resistant multistage polymers having an alkaline-insoluble polymer and an alkaline-soluble polymer prepared by sequential emulsion polymerization of a mixture of monomers having an acidic functional group at the alkaline-soluble stage, and an alkaline-insoluble polymer, optionally having an amine functional group to bind or join the first stage polymer to the second stage polymer.

Functional groups have also been incorporated into the latex to allow cross-linking with other polymers. U.S. Patent No. 5,326,843 discloses a latex to which hydroxyethyl acrylate has been added to the polymerizable monomer system to provide a reactive functional group. Functional hydroxyl groups can react with aminoplasts and polyisocyanates to form a cured film. Crosslinkable latices are also disclosed in International Patent Applications WO 95/29963 and WO 95/29944.

Latex polymer compositions containing wet adhesion latex polymers are disclosed in U.S. Patent No. 5,208,285. However, the authors disclose relatively small amounts of carboxylic acid containing monomers, which are often required in latex compositions. Accordingly, latex polymer compositions polymerized from monomers having an acid or anhydride functional group and wet adhesion properties, i.e., abrasion resistance, are suitable.

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SUMMARY OF THE INVENTION

The present invention provides compositions of latex polymerized from monomers having a functional acid group or an anhydride group and having a wet adhesion property.

The process of the invention allows the preparation of a first stage polymer which swells, partially dissolves or almost dissolves upon addition of the base, so as to provide an environment for polymerizing the second stage of the alkali-insoluble polymer, providing stability for the alkali-insoluble polymer. The latex polymers of the present invention have an acid content of up to 10% or more based on the total weight of the polymer containing the acid or anhydride functional group. Surprisingly, when the wet-adhesion functional group is added, it has been surprisingly found that latex polymers of this type, when used in paint compositions, provide excellent wet-adhesion regardless of the presence of the acid or anhydride functional group.

The present invention provides polymers that can be suitably used in such compositions as building coatings, industrial coatings, automotive coatings, sealants such as adhesives, paper coating compositions such as inks, lacquers and the like .

The latex compositions of the present invention can be prepared by two-stage polymerization of a first-stage polymer and a second-stage polymer.

The first-stage polymer is formed by emulsion polymerization (00).

A monomer mixture comprising at least one carboxylic acid or anhydride functional monomer or monomer which imparts sensitivity to the first stage polymer to alkaline reagents reacting with various comonomers, optionally in the presence of a wet adhesion promoter.

Suitable monomers having a functional acid group or anhydride group include acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid, crotonic acid, citraconic acid, mesaconic acid, itaconic acid, maleic acid, fumaric acid, 3-acrylamido-3- methylbutanoic acid, acrylic anhydride, methacrylic anhydride, ethacrylic anhydride, crotonic anhydride, citraconic anhydride, mesaconic anhydride, itaconic anhydride, maleic anhydride, fumaric anhydride, p-styrene carboxylic acid, p-styrene sulfonic acid, vinylsulfonic acid ,

2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate,

3-Sulfopropyl acrylate, acid

2-acrylamido-2-methylpropanesulfonic acid and the like, including mixtures thereof. In one embodiment of the present invention, the preferred acidic monomer is selected from the group consisting of acrylic acid and methacrylic acid.

The amount of functional acid groups or anhydride groups present in the first stage emulsion polymerization determines the degree of solubility of the first stage after addition of the base. The solubility of the polymer requires a minimum amount of acid or anhydride functional groups depending on the hydrophobicity of the comonomers, the molecular weight of the polymer, the chemical nature of the acid or anhydride monomer, and the sequence of monomer distribution in the polymer. Acid- or anhydride-modified polymers can improve or deteriorate adhesion, depending on the coating system and substrate. When used in excess, acidic or anhydride groups will impart water sensitivity to the coating film and thereby impair wet adhesion. According to the above criteria, the preferred weight of the acidic or anhydride functional monomers present in the first stage polymerization is at least 2% by weight, preferably at least 3% by weight, more preferably about 5% to 50% by weight; even more preferably from about 8% to about 30% by weight, and most preferably from about 10% to 20% by weight, based on the total weight of the monomers used in the first stage reaction.

Examples of coraonomers suitable for carrying out the polymerization of the first step include monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, hydroxy styrene methacrylate, methylstyrene, acrylonitrile, vinyl acetate, and other C1 -C12 alkyl acrylates or hydroxyalkyl acrylates and methacrylates, vinyl 2-ethylhexanoate, vinyl propionate, vinyl neodecanoate, vinyl neonanoate, vinyl versatate, vinyl pivalate, and the like, and / or mixtures thereof.

The first stage polymer may have different molecular weights. The molecular weight is controlled by the addition of a suitable chain transfer agent, as is well known in the art. Examples of suitable chain transfer agents include: &lt; 00 &gt;

Alkyl mercaptans such as octyl mercaptan and decyl mercaptan, mercaptoacetic acid esters such as mercaptoacetic acid ethyl ester and mercaptoacetic acid 2-ethylhexyl ester, and mercaptopropionic acid esters such as mercaptopropionic acid esters. In a preferred embodiment, the chain transfer agent may be selected from the group consisting of 4-ethylhexyl mercaptopropionate and isooctyl mercaptopropionate, or mixtures thereof. The size of the usually obtained average molecular weight Mn ranges from 500 to 100,000.

Optionally, a wet adhesion promoter is added to the first-stage polymerization to provide the alkaline-soluble polymer to impart wet-adhesion properties to the first-stage polymer and the final latex product. The wet adhesion promoter is preferably a monomer having a nitrogen functional group effective to increase the wet adhesion properties of the latex composition.

Preferred wet adhesion promoters include compounds having an amino group, an ureide group, or an N-heterocyclic group, such as dialkylaminoalkyl esters and dialkylaminoalkylamides of acrylic acid or methacrylic acid, and especially those having 1 to 5 carbon atoms in the alkyl group, the compounds obtained by free radical polymerization of urea, ethylene urea or propylene urea; and polymerizable imidazolidinones with the -NC (O) N- group as part of the cyclic structure of the five-membered ring.

Examples of wet adhesion promoters which provide the desired wet adhesion property include dimethylaminoethyl acrylate, diethylaminoacrylate, dimethylaminopropyl acrylate, and the like.

• · ι ··· ·· ·

3-dimethylamino-2,2-dimethylpropyl-1-acrylate,

2-N-morpholinoethyl acrylate, 2-N-piperidinoethylacrylate,

N- (3-dimethylaminopropyl) acrylamide (used herein includes methacrylamide),

N- (3-dimethylamino-2,2-dimethylpropyl) acrylamide,

N-dimethylaminomethyl acrylamide,

N- (4-morpholinomethyl) acrylamide,

N- (2-methacryloyloxoethyl) ethyleneurea, methacrylamidoethylethyleneurea,

N- (2-methacryloxyacetamidoethyl-N, Ν, N ´, N´-ethyleneurea, allylalkylethyleneurea, N-methacrylamidomethylurea, N-methacryloylurea,

N- [3- (1,3-diazacyclohexan-2-one-propyl)] methacrylamide,

2- (1-imidazolyl) ethyl methacrylate,

2- (1-imidazolidin-2-one) ethyl methacrylate, vinylimidazole, vinylpyrrolidone and 3-allyl-4,5-methoxy-2-imidazolidinone.

Preferred wet adhesion promoters include N- (2-methacryloyloxyethyl) ethylene urea and methacrylamidoethylethylene urea. In addition, it has been found that propyleneimine can additionally react with an alkaline-soluble first-stage polymer to impart a wet adhesion property and act as a base to neutralize the alkaline-soluble first-stage polymer. It may also react with the first stage polymer after the second stage polymer has formed.

The amount of wet adhesion promoter present in the first-stage emulsion polymerization process is generally from about 0.1 to 20% by weight, more preferably from about 1 to 10% by weight, and most preferably from about 1.9 to 5% by weight, calculated on the total weight of the monomer composition in the first stage feed.

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In performing the emulsion polymerization, at least one initiator or catalyst is used at a concentration sufficient to initiate or catalyze the polymerization reaction. The concentration of initiator and / or catalyst will vary depending on the weight of monomers employed. The particular concentration used at any given time will depend on the specific monomer mixture that reacts and the specific initiator used, which is well known to those skilled in the art, and often ranges from about 0.01 to 3. % by weight; more preferably from about 0.05 to 2% by weight, and most preferably from about 0.1 to 1% by weight, based on the weight of the monomers employed. It is also known in the art that traces of metal ions can be added as activators, if desired, to improve the polymerization rate. Examples of suitable initiators are hydrogen peroxide, peracetic acid, t-butyl hydroperoxide, ammonium persulfate, potassium persulfate, sodium persulfate, and any other known initiator. Also suitable are redox catalyst systems, such as sodium persulfate, sodium formaldehyde sulfoxylate, sodium cumene hydroperoxide, sodium metabisulphite, hydrogen peroxide-ascorbic acid, and other known redox systems.

The sprayable polymerizable compositions may also contain any of the other known additives commonly used in emulsion polymerization processes, such as crosslinking agents, dispersing aids, emulsifiers, photosensitizers, dyes, bactericides, fungicides, etc.

At the end of the polymerization of the first stage, the polymer is introduced

· · · • · · · · · · ·

The alkaline-soluble first step adds a neutralizing agent or base in such a way that the polymer swells, partially dissolves, or completely dissolves. Suitable bases include ammonia, monoethanolamine, dimethylaminoethanol, ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide and all other hydroxides of elements of Groups IA and IIA and the like. As mentioned above, propyleneimine can also be effective in neutralizing the first-stage polymer soluble in alkaline substances, which at the same time provides the end product with a wet adhesion property.

Depending on the equivalents of acid in the alkaline-soluble polymer, 0.01-1.5 equivalents of base are usually added to the polymer to swell, partially dissolve, or substantially dissolve to provide a stabilized dispersion medium for the second stage polymerization.

According to one aspect of the present invention, the prepared first stage latex polymer may be stored for later neutralization. According to another aspect of the present invention, the first stage polymer may be neutralized and used as a dispersant for other latex polymers, including the second stage emulsion polymerization process of the invention.

By using the first stage polymer as the medium for the second stage emulsion polymerization of alkaline insoluble monomers, it has been found that the end product exhibits improved film-forming, wet adhesion and other properties.

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The monomers useful for the second stage polymerization include any alkali-insoluble monomers, i.e., those substantially free of carboxylic acid or anhydride functional groups, such as those containing acrylic, styrene, vinyl functional group or versatate group. As used herein, the term substantially free means less than about 10% by weight, preferably less than about 5% by weight, and more preferably less than about 2% by weight, based on the total weight of the polymer. Examples of such monomers are acrylate and methacrylate esters, styrene, alkylstyrenes, vinyltoluene, vinyl acetate, vinyl alcohol, acrylonitrile, vinylidene chloride and vinyl ketones. Other examples of monomers useful in this invention include for example propyl, isopropylmethakrylát, butyl methacrylate, n-amylmethakrylát, sek.amylmethakrylát methacrylate, hexyl methacrylate, lauryl methacrylate, stearyl methacrylate, ethylhexyl methacrylate, Crotyl, cinnamylmethakrylát, oleylmethakrylát, ricinoleylmethakrylát, hydroxyethyl methacrylate, hydroxypropyl methacrylate, vinyl propionate, vinyl butyrate, vihyl- tert-butyrate, vinyl caprate, vinyl stearate, vinyl laurate, vinyl oleate, vinyl methyl ether, vinyl ether, vinyl n-propyl ether, vinyl isopropyl ether, vinyl n-butyl ether, vinyl isobutyl ether, vinyl isooctyl ether, vinyl phenyl ether, alpha-chlorvinyl methyl ether, acrylamide, acrylamide; , N-arylacrylamides,

N-vinylpyrrolidone, N-vinyl-3-morpholinones,

N-vinyloxazolidone, N-vinylimidazole and the like, including mixtures thereof.

• · · · · · · ·

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Κ optional additives that may be contained in alkaline-insoluble second-stage polymerization polymers, for example, include other monomers such as vinyl esters, monomers with acid and / or anhydride groups, crosslinking agents, chain transfer agents and other agents which are well known in the art. The number average molecular weight can range from 500 to 500,000 or more up to infinity when suitable chain transfer agents or crosslinking agents are used. Optionally, a wet adhesion promoter is also added to the second stage polymerization to give the final latex product wet adhesion properties; provided, however, that it has been incorporated into at least one of the first stage polymers or the second stage polymer.

The desired ratio of monomer feed for the second stage polymerization introduced into the first stage polymer environment covers a wide range depending on the desired properties of the final latex composition and the acid level at each stage. For example, the amount of first stage polymer incorporated in the second stage polymerization may be small when using a material with a higher carboxyl group content [e.g., 10 parts per hundred parts, i.e. first stage plus second stage (phr,), first stage polymer that contains 20% methacrylic acid] or greater when using a material with a lower carboxylic acid content [e.g. 20 phr of a first stage polymer containing 10% methacrylic acid]. Suitable ranges are from 1:99 to 99: 1. The weight ratio of the second stage monomer introduced is preferably from about 5:95 to 95: 5, and more preferably from about 10:80 to 80:10.

For example, the resulting final latex compositions can be used as binders for building coatings, industrial coatings, automotive coatings, sealants, adhesives, paper coatings, printing inks, for varnishes and the like.

In the coating composition, the alkali-insoluble polymers dispersed in the neutralized first-stage polymer may be used in amounts based on the weight of the solids, which may range from about 5% to about 90% of the total weight of the coating composition. Coating compositions containing these unique polymers have been shown to exhibit excellent wet adhesion, high gloss and improved block resistance. The coating compositions may contain, in addition to the polymers of the present invention, conventional additives such as pigments, fillers, dispersants, wetting agents, coalescing additives, rheology modifiers, drying retardants, biocides, antifoams and the like.

The following description is a general description of an emulsion polymerization process for preparing alkaline-insoluble polymers dispersed in a substantially soluble alkaline polymer. In a conventional reaction, a mixture of acrylic acid or methacrylic acid, acrylate and methacrylate esters and / or styrene monomers, wet adhesion monomer and other optional additives is introduced into the reactor where they are polymerized in an emulsion in the presence of a chain transfer agent and an initiator. The polymerization is conveniently carried out using a surfactant or emulsifier and in an aqueous medium. The temperature may range from about 35 ° C to about 90 ° C or above; the preferred temperature is between about 70 ° C and about 85 ° C. The pressure is not critical and depends on the nature 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 · 0 · 9

0 β 0 00 0 00. 0 0

0 · 0 0 0 0 0 0 0 0 · 00 of the monomers used, with normally gaseous monomers requiring excess pressure. Upon completion of the first stage monomer feed, the reaction is maintained at the reaction temperature until the residual monomer level is less than about 5000 ppm, followed by addition of the desired neutralizing agent until the first stage polymer swells, partially dissolves, or substantially dissolves. Thereafter, second stage monomers, including optional additives such as wet adhesion monomers, are introduced into the first stage polymer environment at the above temperatures. After the second stage monomer feed is complete, the reactor is maintained at a temperature for about one hour, then cooled and the latex product collected. At this point, the latex may optionally be further neutralized.

Examples

In the following examples, the present invention will be explained in more detail, but these examples are illustrative only and are not intended to limit the scope of the invention in any way.

ExampleA

Synthesis of styrene acrylic polymer

In a 1 liter monomer feed roller, a mixture of monomers was prepared by weighing 100 grams of styrene, grams of methyl methacrylate (Aldrich) and 7 grams of 2-ethylhexyl mercaptopropionate (Hampshire Chemicals). A second 1 liter metering roller was prepared to prepare a second monomer mixture by weighing 210 grams of styrene, 250 grams of methyl methacrylate (Aldrich), 330 grams of butyl acrylate (Union Carbide) and 50 grams of methyl methacrylate with 25% by weight N- (2-methacryloyloxyethyl) (ROHAMERE 6844-0) (Rohm Tech).

• · • ···

For a batch of 925 grams of water and 2.5 grams of GR-9M (Union Carbide), a two-liter plastic flask with jacket was used, equipped with a four-blade mechanical stainless steel stirrer, Claisen connecting tube, Friedrichs water cooler, nitrogen and condensation flushing, thermometer and inlets. for monomer feed.

In a separate vessel, an initial oxidant solution was prepared by dissolving 2.5 grams of ammonium persulfate in 320 grams of water. A delayed oxidation solution was also prepared in a separate vessel by dissolving 5 grams of ammonium persulfate in 100 grams of water. While flushing with nitrogen, the reactor was heated to 80 ° C with controlled temperature water circulating in the reactor jacket.

After the reactor charge reached 80 ° C, an initial oxidant solution was added to the reactor. Two minutes later, the monomer feed was fed to the reaction vessel with constant stirring while maintaining the reaction temperature between 79-81 ° C over a period of 40 minutes using FMI pumps with a Teflon tube, maintaining the reaction temperature between 79 and 81 ° C. minutes, the reaction was allowed to proceed at 80 ° C. 20 grams of a 15% ammonium hydroxide solution was added to the product. After a further 15 minutes, a second monomer mixture was fed to the reactor over a period of 2 hours in parallel with the delayed oxidant solution. The product was maintained at 80 ° C for 1 hour.

An additional 20 grams of a 15% ammonium hydroxide solution was added to the resulting product. Then the product was cooled to room temperature. The resulting latex containing 48% solids had a pH of 8, and an average particle diameter of 252 nanometers (nm) as measured by a Microtrac particle size analyzer (Leeds-Northrop).

• 99 Φ Φ Φ Φ · Φ Φ Φ Φ Φ Φ · · · · · · · · • · • • • • • • 9 9 9 9 9

Three samples were prepared as above with a styrene content of 30% by weight (Al), 10% by weight (A2) and 20% by weight (A3).

Example B

Manufacture of paints

A pigment paste was prepared by mixing the following ingredients, respectively: 30 grams of water, 40 grams of propylene glycol, 9 grams of Tamol 165 dispersant (Rohm and Haas), 2.5 grams of Triton ^R CF-10 surfactant (Union Carbide Corp.), 1.5 grams of Strodex PK-90 (Dexter), 1.0 grams of AMP-95 (Angus), 2.0 grams of Nyosept 145 (Huls), 2.0 grams of Foamaster AP (Henkel), and 225 grams of titanium dioxide TiONA RCL-535 (SCM). The mixture was rubbed in a speed disperser for 20 minutes to achieve a fineness of 6+ on the Hegman scale.

The paint was prepared by mixing the following ingredients with gentle agitation, respectively: 550 grams of the latex of Example A, 313 grams of pigment paste prepared above, 26 grams of Texel (Eastman) coalescing solvent, 10.5 grams of Polyphase P-20-T antifungal agent ( Troy), 13.0 grams of Acrysol RM-2020 (Rohm & Haas), grams of Butyl Carbitol solvent (Union Carbide Corp.) and 134 grams of water.

Example C

Wet adhesion testing

The wet adhesion was tested by pouring a wet layer of this to this to this to this to «♦ ·· ·· latex paints with a thickness of 0.18 millimeters for a glossy film of an alkyd paint (oil-based) which has been allowed to dry for at least 3 weeks but not more than 6 weeks. The latex coating was allowed to dry for 24 hours, then the film was cross-hatched, placed in water for 30 minutes, then removed from the water and placed in an abrasion testing machine. The cross-hatched section was scrubbed for 500 cycles using a 5% lava-soap solution and a standard scrub brush. The results are shown in Table A below.

TABLE A

Example Styrene content Wet adhesion after 24 hours remaining% Al 30% 100% A2 10% 100% A3 * 20% 15%

* The wet adhesion monomer has been omitted

In accordance with the present invention, the wet adhesion value after 24 hours is preferably at least 90%, more preferably 95% and most preferably 100%.

While the invention has been described with respect to specific aspects, it will be apparent to those skilled in the art that this description is not intended to limit the scope of the following claims.

Claims (20)

A latex composition comprising: (i) a first polymer polymerized from at least one monomer having acidic or anhydride functional groups; and (ii) a second polymer, polymerized from monomers substantially free of acid or anhydride functional groups; characterized in that at least one of said first polymer or said second polymer is polymerized from a monomer having a nitrogen functional group effective to enhance the wet adhesion property of the latex composition. 2. The latex composition of claim 1 wherein said first polymer comprises at least 2.0% by weight of an acid or anhydride functional monomer based on the total weight of said first monomer. The latex composition of claim 1, wherein said first polymer comprises at least 5.0% by weight of an acid or anhydride functional monomer based on the total weight of said first monomer. The latex composition of claim 1, wherein said first polymer comprises at least 10.0% by weight of an acid or anhydride functional monomer based on the total weight of said first monomer. ·· »· 0 0 0 · · 8 · · 4 · · · ··· β β 0 0 0 0 0 • ·· 9 0 0 0 • · 0 · 0 0 0 0 0 0 '· 0' 0 0 0 0 0 ' 0 0 0 0 0 0 0 0 0 «00 The latex composition of claim 1, wherein said first polymer is in the form of a solution. 6. The latex composition of claim 1, wherein said first polymer is in swollen or partially dissolved form. The latex composition of claim 1, wherein said first polymer is in particulate form. The latex composition of claim 1, wherein said first polymer and said second polymer are at least partially copolymerized. The latex composition of claim 1, wherein the acid or anhydride functional monomer is selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid, crotonic acid, citraconic acid, mesaconic acid. , itaconic acid, maleic acid, fumaric acid, 3-acrylamido-3-methylbutanoic acid, acrylic anhydride, methacrylic anhydride, ethacrylic anhydride, crotonic anhydride, citraconic anhydride, mesaconic anhydride, itaconic anhydride, maleic anhydride fumaric anhydride, p-styrene carboxylic acid, p-styrene sulfonic acid, vinylsulfonic acid, 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, 3-sulfopropylacrylate, 2-acrylamido-2-methylpropanesulfonic acid and mixtures thereof. A latex composition according to claim 1, characterized in that the latex composition is characterized in that the latex composition is as defined in claim 1. 9, wherein at least one of said first stage polymer or said second stage polymer is polymerized with at least one comonomer selected from the group consisting of methyl acrylate , ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, styrene, substituted styrene, such as alpha-methylstyrene, acrylonitrile, alkyl acrylate portions, alkyl or alkyl acrylate up to 12 carbon atoms, vinyl-2-ethylhexanoate, vinylpropionate, vinylneodecanoate, vinylneononanoate, vinyl versatate, vinyl pivalate and mixtures thereof. 11. The latex composition of claim 1 wherein said wet-adhesion monomer is selected from the group consisting of dimethylaminoethyl acrylate, diethylaminoacrylate, dimethylaminopropyl acrylate, 3-dimethylamino-2,2-dimethylpropyl-1-acrylate, 2-N-morpholinoethyl acrylate, 2-N-piperidinoethylacrylate, N- (3-dimethylaminopropyl) acrylamide (used herein includes methacrylamide), N- (3-dimethylamino-2,2-dimethylpropyl) acrylamide, N-dimethylaminomethyl acrylamide, N- (4-morpholinomethyl) acrylamide, N- (2-methacryloyloxyethyl) ethyleneurea, methacrylamidoethylethyleneurea, N- (2-methacryloxyacetamidoethyl-N, N, N ', N' -ethyleneurea, allylalkylethyleneurea, N-methacrylamidomethylurea, N-methacryloylurea, N- [3- (1,3-diazacyclohexan-2-one-propyl)] methacrylamide, 2- (1-imidazolyl) ethyl methacrylate, fefe 2- (1-imidazolidin-2-one) ethyl methacrylate, vinylimidazole, vinylpyrrolidone and 3-allyl-4,5-methoxy-2-imidazolidinone. The latex composition of claim 11, wherein said nitrogen-functional monomer is selected from the group consisting of: N- (2-methacryolyloxyethyl) ethyleneurea and methacrylamidoethylethyleneurea. 13. The latex composition of claim 1 further comprising a neutralizing agent selected from the group consisting of ammonia, triethylamine, monoethanolamine, dimethylaminoethanol, ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, and propyleneimine. 14. The latex composition of claim 1 wherein said substantially acid-free or anhydride-functional monomer is selected from the group consisting of propyl methacrylate, isopropyl methacrylate, butyl methacrylate, n-amyl methacrylate, sec. ethylhexyl methacrylate, crotyl methacrylate, cinnamyl methacrylate, oleyl methacrylate, ricinoleyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, vinyl propionate, vinyl butyrate, vinyl n-butyl ether, vinyl n-butyl ether, vinyl n-ethyl ether, vinyl stearate, vinyl stearate, vinyl stearate, vinyl stearate, vinyl stearate vinylisobutyl ether, vinylisoctyl ether, n vinylphenyl ether, alpha-chlorvinylphenyl ether, vinylnaphthyl ether, methacrylonitrile, acrylamide, methacrylamide, N-alkyl acrylamides, N-arylacrylamides, • 0 0 0 £ '0 · 9 0 0 0 0 0 0 β · 0 0 0 0 · N-vinylpyrrolidone, Ν-vinyl-3-morpholinones, N-vinyloxazolidone, N-vinylimidazole and mixtures thereof. 15. The latex composition of claim 1, wherein said second stage comprises less than about 5% by weight of acid or anhydride functional monomers based on the total weight of the second polymer. The latex composition of claim 1, wherein the first polymer is polymerized from methacrylic acid, butyl acrylate and methyl methacrylate and optionally methacrylamidoethylethylene urea. 17. The latex composition of claim 1 wherein the second polymer is polymerized from butyl acrylate and methyl methacrylate and optionally methacrylamidoethylethylene urea. The latex composition of claim 1, wherein the first polymer is polymerized from methacrylic acid, styrene and methyl methacrylate, butyl acrylate and optionally methacrylamidoethylethylene urea. The latex composition of claim 1, wherein the second polymer is polymerized from butyl acrylate, styrene and methyl methacrylate and optionally methacrylamidoethylethylene urea. A coating composition comprising water, a pigment and a latex composition according to claim 1.