CA2139379A1 - Anhydride-functional monomers and polymers and reactive compositions prepared from same - Google Patents

Abstract

Anhydride-functional polymerizable monomers having the structure:

Description

~ 2139379 ., . . ~
i ... .. .

ANHYDRIDE-F[JNCTIONAL MONOMERS AND POLYMERS
AND ~EACTrVE COMPOSITIONS PREPARED FROM SAl~E
BACKGROUND OF THE INVENTION
5 1. Field of the Invention.
This invention involves novel anhydride-functional polymerizable monomers and -polymers and reactive compositions prepared from those monomers. The anhydride-functional monomers have the structure:
R' H2C=C
lS b \ 0/
wherein R', R2, R3 and R4 are each indlvidually hydrogen or methyl.
This invention also relates to anhydride-functional polymers having an average of at least two anhydride groups per molecule and which are obtained by polymerizing, under free radical addition polymerization conditions, (i~-the anhydride-functional monomer of this invention; and (ii) optionally, at least one other unsaturated monomer copolymerizable` with the anhydride-functional monomer.
The anhydride-functional polymers are useful as corrosion or scale inhibitors, thickeners, dispersants and as reactive agents and/or crosslinking agents for compounds having functional .
groups, such as epoxy, hydroxyl or amine groups, which are reactive witll anhydride groups.
The anhydride polymers can, therefore, be utilized in a variety of materials such as plastics, fibers, adhesives, paper sizing, inks and, particularly, coating composltions.
This invention also relates to novel reactive compositions which utilize the anhydride-S functional polymer. The reactive compositions can be reacted at room temperature or force dried at temperatures ranging up to about 350F or higher if desired. When utilized as reactive crosslinking agents for coatings, the anhydride-functional polymers may be utilized in a variety of coating applications, including primers and topcoats as well as clearcoats and/or basecoats in clearcoat/basecoat compositions. The monomers themselves can be utilized as crosslinkers, neutralizers, scale preventatives, thickeners and many other applications.
The reactive compositions typically involve the combination of the anhydride-functional polymer with materials reactive with anhydrides such as polyepoxides, polyamines, polyols, etc.
One preferred curable coating combination comprises the anhydride-functional polymer and a polyol, preferably a hydroxy-functional polymer, optionally in combination with an epoxide or polyepoxide. Another preferred reactive composition comprises the anhydride-functional polymer, an acid-functional polymer,~an epoxide or polyepoxide, and, optionally, a polyol. All of these combinations provide fast reacting, durable coatings which may minimi7e the toxicity problems whlch may be associated with other low temperature curing systems.

2. Description of the Prior Art.
Unsaturated anhydrides, such as maleic anhydride, and copolymers made from maleic anhydride are known in the art. Such anhydride copolymers are heterogeneous with respect to the distribution of anhydride groups along the backbone of the polymer due to the abnormal copolymerization behavior of maleic anhydride with other monomers, and the acid groups gen-erated from opening these anhydrides by reaction with hydroxyl or amine groups are not highly reactive for further cure reactions, e.g. with epoxy groups, due to steric hindrance arising from the proximity of the anhydride ring to the polymer backbone. Such anhydride-functional 5 polymers are also relatively viscous and are difficult to utilize in combination with low levels of solvent. Additionally, such polymers may form dark colored materials when certain base catalysts, such as N-methyl imidazole, are used to accelerate a subsequent reaction of the polyanhydride with reactive materials such as hydroxy-functional compounds.
Coating compositions comprising polyanhydrides and hydroxy-functional compounds are known in the art. For example, U.S. 4,946,744 teaches clearcoat/basecoat combinations involving (i) a polyanhydride, for example, such as that prepared by copolymerization of maleic anhydride with (meth)acrylic monomers, and (ii) a polyol. U.S. patent 5,227,243 teacbes curable compositions comprising a polyanhydride, a polyol and an epoxy-functional compound.
U.S. patent 4,871,806 teaches curable compositions comprising a polyanhydride, a polyacid, a polyol and an epoxy-functional compound. U.S. patent 4,859,758 teaches an acid-functional cellulose ester-based polymer which could be used in combination with a polyanhydride and a polyepoxide. U.S. patent 4,927,868 teaches copolymers of ~ olefins and unsaturated anhydrides which could be used with a polyepoxide and, preferably, a polyacid. U.S. patent 4,374,235 teaches anhydride-functional polymers prepared by the polymerization of an alkenyl succinic 20 anhydride and a vinyl monomer. The prior art has not, however, taught polymers obtained by the polymerization of the novel anhydride monomers of this invention.

BRIEF SUMI\~ARY OF THE INVENTION
This invention involves polymerizable (Meth)acrylic unsaturated monomers having pendent anhydride functionality. These versatile monomers have a variety of potential applications due to their combination of reactive sites. Either the anhydride or the unsaturation functionality could be reacted first, followed, if desired, by subsequent reaction of the other functionality. For example, the anhydride group could be reacted with hydroxyl groups on a alcohol or polyol to provide a product having one or more pendent, polymerizable unsaturation sites. Such a product could be subsequently polymerized, either with or without additional copolymerizable monomers such as styrene or (meth)acrylate monomers, by peroxide initiation or by exposure to high energy radiation such as electron beam or ultraviolet light. The anhydride-functional monomer could also be hydrolyzed to produce a diacid-functional monomer.
A particularly preferred use for the monomers of this invention involves their use in polymers derived by polymerizing the anhydride monomer through its unsaturation either as a homopolymer or, preferably, in combination with one or more additional copolymerizable monomers. The anhydride-functional polymers can be, if desired, fully or partially hydrolyzed, or ring opened e.g. by half-ester or half-amide reactions, to produce acid-functional polymers, or they can be directly utilized as crosslinking agents for materials having functionality which .
is reactive with anhydride groups such as epoxy, hydroxyl or amine functionality.
Therefore, this invention also relates to curable compositions which comprise (i) anhydride-functional polymers prepared using the monomers of this invention, and (ii) a compound having an average of at least two functional groups per molecule which are reactive 213937~

, with anhydride groups. A particularly preferred curable composition comprises (i) the anhydride-functional polymer and (ii) a hydroxy-functional compound having an average of at least two hydroxyl groups per molecule, optionally in combination with an epoxide or polyepoxide. Another preferred combination comprises (i) the anhydride-functional polymer, S (ii) an acid-functional compound having an average of at least two acid groups per molecule, (iii) an epoxide or polyepoxide, and, optionally, (iv) a hydroxy-functional compound having an average of at least two hydroxyl groups per molecule. Another useful composition comprises (i) the anhydride-functional polymer and (ii) a polyamine compound having an average of at least two primary and/or secondary amine groups per molecule. Another useful composition 10 comprises (i) the anhydride-functional polymer and (ii) a polyepoxide. The term "compound"
is used in its broadest sense to include monomers, oligomers and polymers.
Although the curable compositions of this invention can be utilized without solvent in many applications, it is frequently preferred to utilize them in combination with about 5% to about 75% by weight of an inert solvent. It is convenient to provide the curable composition 15 as a multicomponent system which is reactive upon mixing the components. Especially preferred is a two-component systern wherein the anhydride-functional polymer and the acid-functional compound, if utilized, are combined in one package and the epoxy-functional compound and/or the hydroxy-functional compound provide a second package. The two packages can then be mixed together to provide the curable composition immediately prior to 20 use.
In one preferred application, this invention also relates to coated substrates having a multi-layer decorative and/or protective coating which comprises:

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i (a) a basecoat comprising a pigmented film-forrning polymer; and (b) a transparent clearcoa~ comprising a film-forrning polymer applied to the surface of the basecoat composition;
wherein the clearcoat and/or the basecoat comprises the curable compositions of this invention.
5 The terrn "film forming polymer" means any polymeric material that can form a film from evaporation of any carrier or solvent.
Accordingly, one obiect of this invention is to provide novel unsaturated anhydride-functional monomers and polymers therefrom. Another object is to provide improved curable compositions having excellent reactivity at low temperatures. It is a further object to provide 10 coating compositions whicll may be utilized as primers, topco~ts, or clearcoats and/or basecoats in clearcoat/basecoat compositions. Another object is to provide an improved t~vo-pacl~age coat-ing composition wherein one package comprises a novel anhydride-functional polymer and, optionally, an acid-functional compound and the other package comprises an epoxy-functional compound and/or a hydroxy-functional compound. Another object is to provide coatings havin~
lS excellent reactivity, exterior durability and corrosion resistance. A further object is to provide improved coating compositions which can be cured at room temperature or force dried at elevated temperatures. It is also an object of this invention to provide curable compositions which are relatively low in viscosity and which can be utilized with reduced amounts of volatile organic solvents. These and other objects of the invention will become apparent from the 20 following discussions.

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DETAILED DESCRIPI ION OF THE INVENTION
The unsaturated anhydride monomers of this invention ean be conveniently prepared by the reaetion of a halogenated alkyl sueeinie anhydride with a (meth)acrylie acid, or preferably, a (meth)aerylic acid salt. Halogenated alkyl succinic anhydrides having a primary halide are 5 espeically preferred due to their reactivity and ready availability of starting materials. The (meth)acrylic acid salt is prepared by treating acrylic or methacrylic acid with a suitable base, such as a tertiary amine or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. The halogenated alkyl suecinie anhydride ean be readily prepared by, for example, the Anti-Markovnikov addition of hydrogenbromide to an alkenyl succinic anhydride.
Representative alkenyl succinic anhydride monomers include vinyl succinic anhydride, allyl succinic anhydride, 2-(1-methyl-2-propenyl)succinic anhydride, 2-(2,3-dimetllyl-2-propenyl)suceinie anhydride,2-(1,1-dimethyl-2-propenyl)succinic anhydride,2-(1,1,2-trimethyl-2-propenyl)sueeinie anhydride, ete. A wide variety of alkenyl suceinic anhydrides are eommereially available from The Humphrey Chemical Company, P.O. Box 325, North Haven, Connecticut. Alkenyl suceinie anhydrides are routinely prepared by the reaction of maleic anhydride and olefins, optionally in the presenee of solvents, diluents, antioxidants, eatalysts, additives, ete. at temperatures ranging from about 170C to about 270C. Representative pre-parations are taught in U.S. patents 2,411,215, 3,819,660, 3,855,251, 3,953,475, 4,388,471, 4,599,433, 4,761,488, 5,021,169 and many others.
Allyl sueeinie anhydride (somPtimes ealled propenyl succinic anhydride) is especially preferred as the alkenyl suceinie anhydride due to its reaetivity and cornmercial availability. The synthesis of allyl succinie anhydride has been representatively taught by Alder, et al., Chem Ber.

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1983, 76, 27; and Phillips, et al., J. Am. Chem. Soc. 1958, 80, 3663; and Anderson, et al., U.S. patent 3,243,480 issued March 29, 1966. The synthesis taught in these references involves the ene reaction, in a bomb at 200C for approximately 12 hours, of maleic anhydride and propylene in the presence of a diluent such as benzene and a polymerization inhibitor such as 5 p-t-butylcatechol. Allyl succinic anhydride is commercially available from a variety of sources, including Polysciences, Inc. at 400 Valley Road, Warrington, Pennsylvania, and from Wacker Chemicals (USA), Inc. at 50 Locust Avenue, New Haven, Connecticut. When allyl succinic anh~,~dride is utilized as the alkenyl succinic anhydride and converted to the halogenated alkyl succinic anhydride by Anti-Markovnikov addition of HBr followed by reaction ~vith a (meth)-10 acrylic acid salt, the unsaturated anhydride monomer product ~vill have R~ as H or CH3 and R',R3 and R4 will each be H.
The hydrogen halides which are reacted with the alkenyl succinic anhydride to produce the halogenated alkyl succinic anhydride, are commercially available, or can be generated by contacting an aqueous hydrogen halide solution with phosphorous pentoxide. When Anti-15 Markovnikov addition is desired, the hydrogen halide should be hydrogen bromide, and shouldbe used in combination with a peroxide catalyst, such as dibenzoyl peroxide at temperatures typically ranging from 10 to about 40C. In the absence of peroxides, Markovnikov addition will take place across the double bond.
The acid salt preferably utilized for reaction with the halogenated alkyl succinic anhydride 20 is prepared by admixing the (meth)acrylic acid monomer with a suitable base in approximately a one-to-one equivalent ratio. The reaction is exothermic and normally can be conducted at about 20-50C. Suitable bases include tertiary amines such as triethyl amine, N,N-213~373 dimethylaniline, diazobicyclo [5.4.0] undec-7-ene, 1,4-diazobicyclo[2.2.2] octane, etc., and alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, etc. The acid or acid salt and the halogenated alkyl succinic anhydride are admixed, typically in an equivalent ratio of acid or acid salt to halide ranging from 1 to 1 to about 2 to 1 and m~int~ined at about 70 to 100C for 1 to 4 hours.
The polymerization of the novel monomers of this invention either alone or with other unsaturated copolymerizable monomers, such as (meth)acrylic monomers or styrene, proceeds at excellent yield and provides polymers having excellent reactivity, flexibility and overall performance. The reactivity and flexibility are due, at least in part, to the fact that the anhydride groups are separated by several carbon atoms away from the backbone of the poly-mer. Furthermore, the pendent succinic anhydride group is monosubstituted, rather than disubstituted as is the case for maleic anhydride copolymers resulting in greater flexibility, lower viscosity and enh~nce~ reactivity. Also, since the (meth)acrylate-based anhydride monomers of this invention copolymerize more readily with other typical unsaturated monomers than does maleic anhydride, a wider practical selection of copolymerizable monomers is available. In many applications, the anhydride-funrctional polymers of this invention will also provide less color development in the presence of basic catalysts such as N-methyl imidazole than will the maleic anhydride-based polymers.
1. ANHYDl~IDE-FUNCTIONAL POLYMERS
The anhydride-functional polymers which are useful in the practice of this invention will have an average of at least two anhydride groups per molecule and are prepared by polymerizing a monomer mixture comprising the anhydride monomers and normally at least one other 2139~7g copolymerizable monomer under free radical addition polymerization conditions. Polymerizing under free radical addition polymerization conditions means that the monomers are reacted in the presence of a free radical source at a temperature suf~lcient for polymerization. The mono-mers which are copolymerized with the anhydride monoMer should be free of any functionality which could react with the anhydride group during the polymerization. The anhydride-functional polymers can be conveniently prepared by conventional free radical addition polymerization techniques. Typically the polymerization will be conducted in an inert solvent and hl the presence of an initiator, such as a peroxide or azo compound, at temperatures ranging from 35C to about 200C, and especially 75C to about 150C. Representative initiators include di-t-butyl peroxide, cumene hydroperoxide, and azobis(isobu~yronitrile).
The anhydride-functional monomer should generally comprise about S~O to 100% by weight of the monomer mixture used to prepare the anhydride-functional polymer. The rem~ining ~% to 95% by weight of the monomer mixture will comprise other reactants copolym-erizable with the anhydride-functional monomer.
Representative useful copolymerizable (meth)acrylate monomers include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, ethyl hexyl acrylate, amyl acrylate, 3,5,5-trimethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobornyl methacrylate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide and methacrylamide.
Represe~t~tive monomers which are free of (meth)acrylate functionality and which are copolymerizable with the anhydride-functional monomer include vinyl acetate, vinyl propionate, 10 ' -"

-- - 213~373 .
vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl m-chlorobenzoate, vinyl p-methoxy benzoate, vinyl chloride, styrene, ~-methyl styrene and maleic anhydride.
An especially preferred anhydride-functional free radical addition polymer comprises the free radical addition polymerization product of (a) 5 to 75, and especially 15 to about 50, weight percent of the anhydride monomer; and (b) 25 to 95, and especially 50 to about 85, weight percent of at least one (meth)acrylic monomer; and, optionally (c) 0 to 70, and especially 0 to about 35 weight percent of at least one unsaturated monomer which is free of (meth)acrylate functionality and is copolymerizable with the anhydride monomer.
2. ACID-FUNCTIONAL COMPOUNDS.
The acid-functional compounds which, optionally, can be used in combination with the anhydride-functional polymers of this invention in preparing curable compositions should have an average of at least two carboxylic acid groups per molecule. Although low molecular wei~ht diacids and polyacids such as phthalic acid, succinic acid, adipic acid, azelaic acid, maleic acid, fumaric acid, trimellitic acid and trimesic acid can be utilized in combination with the anhydride-functional polymers in the practice of this invention, it is especially preferred to utilize polymeric acid-functional compounds.
Preferably the acid-functional polymer will have a number average molecular weight of at least about 400. Typlcal number average molecular weights of the carboxylic acid-functional polymers will range from about 500 to about 30,000. Representative acid-functional polymers include acrylics, polyesters and polymers prepared by the reaction of anhydrides with hydroxy-functional polymers as discussed more fully below.

.. . . ..

, 2.A. Carboxylic acid-functional polymers prepared by the half-ester forming reaction of -anhydrides and hydroxy-functional polymers.
S Especially preferred as acid-functional compounds in the curable compositions of this invention are the carboxylic acid-functional polymers prepared by the half-ester opening of the cyclic anhydride by reaction with a hydroxyl group on the hydroxy-functional polymer to form one ester group and one acid group.
Typically, the hydroxy-functional polymers will have number average molecular weiohts of at least about 400 and typical number average molecular weights will range from about 400 to about 30,000, and especially 1,000 to about 15,000. Methods of preparino hydro~y-functional polymers are well known in the art and the method of preparation of the hydro.~;v-functional molecule or polymer which is reacted with the cyclic carboxylic anhydride to produce the optional acid-functional polymer is not critical to the practice of this invention. Representa-tive polymers which can be reacted with anhydrides to produce the acid-functional polymers includethehydroxy-functionalpolyethers, polyesters, acrylics, polyurethanes, polycaprolactones, etc. as generally discussed in Sections 2.A.l. through 2.A.5. below.
2.A.1. Polyether polyols are well known in the art and are conveniently prepared by the reaction of a diol or polyol with the corresponding alkylene oxide.
These materials are commercially available and may be prepared by a known process such as, for example, the processes described in Encyclopedia of Chemical Technolo~v, Volume 7, pages 257-262, published by Interscience Publishers, Inc., 1951. Representa-tive examples include the polypropylene ether glycols and polyethylene ether glycols such as those marketed as Niax~9 Polyols from Union Carbide Corporation.

2.A.2. Another useful class of hydroxy-functional polymers are those prepared by condensation polymerization reaction techniques as are well known in the art. Representative condensation polymerization reactions include polyesters prepared by the condensation of polyhydric alcohols and polycarboxylic acids or anhydrides, with S or without the inclusion of drying oil, semi-drying oil, or non-drying oil fatty acids. By adjusting the stoichiometry of the alcohols and the acids while maintaining an excess of hydroxyl groups, hydroxy-functional polyesters can be readily produced to provide a wide range of desired molecular weights and performance characteristics.
The polyester polyols are derived from one or more aromatic and/or aliphatic polycarboxylic acids, the anhydrides thereof, and one or more aliphatic and/or aromatic polyols. The carboxylic acids include the saturated and unsaturated polycarboxylic acids and the derivatives thereof, such as maleic acid, fumaric acid, succinic acid, adipic acid, azelaic acid, and dicyclopentadiene dicarboxylic acid. The carboxylic acids also include the aromatic polycarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, etc. Anhydrides .such as maleic anhydride, phthalic anhydride, trimelliticanhydride, or Nadic Methyl Arlhydride (brand name for methylbicyclo[2.2 .1]heptene-2, 3-dicarboxylic anhydride isomers) can also be used.
Representative saturated and unsaturated polyols which can be reacted in stoichiometric excess with the carboxylic acids to produce hydroxy-functional polyesters include diols such as ethylene glycol, dipropylene glycol, 2,2,4-trimethyl 1 ,3-pentanediol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclo-213937~

hexanedirnethanol, 1,2-cyclohex~neAimethanol, 1,3-cyclohexanedimet}lanol, 1,4-bis(2-hydroxyethoxy)cyclohexane, trimethylene glycol, tetra methylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycoi, diethylene glycol, triethylene glycol, tetraethylene glycol, norbornylene glycol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 2,4-dimethyl-2-ethylenehexane-1 ,3-diol, 2-butene-1 ,4-diol, andpolyols such as trimethylolethane, trimethylolpropane, trimethylolhexane, triethylolpropane, 1,2,4-butanetriol, glycerol, pentaerythritol, dipentaerythritol, etc.
Typically, the reaction between the polyols and the polycarboxylic acids is conducted at about 120C to about 200C in the presence of an esterification catalyst such as dibutyl tin oxide.
2.A.3. Additionally, hydroxy-functionai polymers can be prepared by the ring opening reaction of epoxides and/or polyepoxides with primary or, preferably, secondary amines or polyamines to produce hydroxy-functional polymers. Representative amines and polyamines include ethanol amine, N-methylethanol amine, dimethyl amine, ethylene diamine, isophorone diamine, etc. Representative polyepoxides include those prepared by condensing a polyhydric alcohol or polyhydric phenol with an epihalohydrin, such as epichlorohydrin, usually under alkaline conditions. Some of these condensation products are available commercially under the designations EPON or DRH from Shell Chemical Compa~y, and methods of preparation are representatively taught in U.S.patents 2,592,560; 2,582,985 and 2,694,694.
2.A.4. Other useful hydroxy-functional polymers can be prepared by the reaction of an excess of at least one polyol, such as those representatively described in 213~73 - s Section 2.A.2 above, with polyisocyanates to produce hydroxy-functional urethanes.
Representative polyisocyanates having two or more isocyanate groups per molecule~ include the aliphatic compounds such as ethylene, trimethylene, tetramethylene, penta-methylene, hexamethylene, 1,2-propylene, 1,2-butylene, 2,3-butylene, 1,3-butylene, ethylidene and butylidene diisocyanates; the cycloalkylene compounds such as 3-isocya-natomethyl-3,5,5-trimethylcyclohexylisocyanate, and the 1,3-cyclopentane, 1,3-cyclo-hexane, and 1 ,2-cyclohexane diisocyanates; the aromatic compounds such as m-phenylene, p-phenylene, 4,4'-diphenyl, 1,5-naphthalene and 1,4-naphthalene diisocyan-ates; the aliphatic-aromatic compounds such as 4,4'-diphenylene methane, 2,4- or 2,6-toluene, or mixtures thereof, 4,4'-toluidine, and 1,4-xylylene diisocyanates; the nuclear substituted aromatic compounds such as dianisidine diisocyanate, 4,4'-diphenylether di-isocyanate and chlorodiphenylene dlisocyanate; the triisocyanates such as triphenyl methane-4,4',4"-triisocyanate, 1,3,5-triisocyanate benzene and 2,4,6-triisocyanate toluene; and the tetraisocyanates such as 4,4'-diphenyl-dimethyl methane-2,2-5,5'-tetraisocyanate; the polymerized polyisocyanates such as tolylene diisocyanate dimers and trimers, and other various polyisocyanates cont~ining biuret, urethane, and/or allophanate linkages. The polyisocyanates and the polyols are typically reacted at temperatures of 25C to about 150C to forrn the hydroxy-functional polymers.
2.A.5. Useful hydroxy-functional polymers can also be conveniently prepared by free radical polymerization techniques such as in the production of acrylic resins. The polymers are typically prepared by the addition polymerization of one or more monomers. At least one of the monomers will contain, or can be reacted to 2139~79 , produce, a reactive hydroxyl group. Representative hydroxy-functional monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 4-hydroxypentyl acrylate, 2-hydroxyethyl ethacrylate, 3-S hydroxybutyl methacrylate, 2-hydroxyethyl chloroacrylate, diethylene glycol methacry-late, tetra ethylene glycol acrylate, para-vinyl benzyl alcohol, etc. T.ypically the hydroxy-functional monomers would be copolymerized with one or more monomers having ethylenic unsaturation such as:
(i) esters of acrylic, methacrylic, crotonic, tiglic, or other unsaturated acids such as:
methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, ethylhexyl acrylate, amyl acrylate, 3,5,5-trimethylhexyl acryl-ate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, dimethylamin-oethyl methacrylate, isobornyl methacrylate, t-butyl methacrylate, ethyl tiglate, methyl crotonate, ethyl crotonate, etc.;
(ii) vinyl compounds such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzroate, vinyl m-chlorobenzoate, vinyl p-methoxybenzoate, vinyl ~-chloroacetate, vinyl toluene, vinyl chloride, etc.;
(iii) styrene-based materials such as styrene, ~-methyl styrene, ~-ethyl styrene, cY-bromo styrene, 2,6- dichlorostyrene, etc.;
(iv) allyl compounds such as allyl chloride, allyl acetate, allyl benzoate, allyl methacrylate, etc.;

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(v) other copolymerizable unsaturated monomers such as ethylene, acrylonitrile, methacrylonitrile, dimethyl maleate, isopropenyl acetate, isopropenyl isobutyrate, acrylamide, methacrylamide, and dienes such as 1,3-butadiene, etc.
The polymers are conveniently prepared by conventional free radical addition polymerization techniques. Frequently, the polymerization will be catalyzed by conventional initiators known in the art to generate a free radical such as azobis(iso-butyronitrile), cumene hydroperoxide, t-butyl perbenzoate, etc. Typically, the acrylic monomers are heated in the presence of the catalyst at temperatures ranging from abou 35C to about 200C, and especially 75C to 150C, to effect the polymerization. Tlle molecular weight of the polymer can be controlled, if desired, by the monomer selection, reaction temperature and time, and/or the use of chain transfer agents as is well known in the art.
Especially preferred polymers in the practice of this invention for reaction with the cyclic anhydride to produce the carboxylic acid-functional polymers are hydroxy-functional polyesters and hydroxy-functional acrylic polymers. An especially preferred hydroxy-functional polymer is the addition polymerization reaction product of (a) 5 to 100, and especially 10 to about 40, weight percent of a hydroxy-functional ethylenically unsaturated monomer and (b) 0 to 95, and especially 60 to about 90, weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.
The cyclic carboxylic acid anhydrides useful in the practice of this invention to produce the carboxylic acid-functional half- ester product by reaction with the hydroxy-functional compound can be any monomeric aliphatic or aromatic cyclic anhydride having one anhydride group per molecule. Representative anhydrides include, phthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, 3-flourophthalic arihydride, 4-chlorophthalic anhydride, tetrachlorophthalic anhydride, tetra bromophthalic anhydride, tetrahydrophthalic anhydride, 5 hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, dodecenylsuccinic anhydride, octy!succinic anhydride, maleic anhydride, dichloromaleic anhydride, glutaric anhydride, adipic anhydride, chlorendic anhydride, itaconic anhydride, citraconicanhydride,endo-methylenetetrahydrophthalicanhydride,cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 4-methyl-4-cyclohexene-2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 1 ,4-cyclohexadiene-1 ,2-dicarboxylic anhy-dride, 1,3-cyclopentanedicarboxylic anhydride, diglycolic acid anhydride, etc. Maleic anhydride is especially preferred because of its reactivity and relatively low cost. Other useful anhydrides include those anhydrides having a free carboxyl group in addition to the anhydride group such as trimellitic anhydride, aconitic anhydride, 2,6,7-naphthalene tricarboxylic anhydride, 1,2,4-15 butane tricarboxylic anhydride, 1,3,4-cyclopentane tricarboxylic anhydride, etc.
The reaction of the hydroxy-functional compound and the cyclic anhydride can be conduct~Pd at temperatures ranging up to about 150C, but should normally be conducted at temperatures less than about 75C, preferably less than 65C, and most preferably between about 35C to 60C. The reaction temperature is m~int~inPd until the reaction has proceeded 20 to provide the desired amount of half-ester groups on the acid-functional compound. Normally, as a convenient measure of the extent of the reaction, the reaction will be continued until no change in the amount of residual unreacted anhydride can be observed, and will generally 213~37~

involve reacting at least about 70%, and preferably at least 95%, of the available anhydride.
If the subsequent end use of the acid-functional polymer can tolerate the rem~ining free anhydride, if any, no separation or removal of the excess unreacted anhydride is necessary. If the end use of the acid-functional polymer requires that it be free of any unreacted anhydride, 5 the reaction can be continued until substantially all of the anhydride has reacted, or the free anhydride may be removed by vacuum distillation or other techniques well known in the art.
The level of anhydride reacted with the hydroxy-functional compound need only be sufficient to provide the final desired acid value of the acid-functional compound. Typically the reaction would be conducted by admixing the polyol and the anhydride at levels to provide at lO least about 0.3 and normally about 0.7 to 1.0 anhydride groups for each hydroxyl group. By conducting the reaction at temperatures less than about 75C the carboxylic acid groups formed as part of the half-ester are not appreciably reactive with the hydroxyl groups themselves and so they do not compete with the ring opening half-ester reaction of the remaining anhydrides.
In order to conduct the reaction at these relatively low temperatures, it is preferred to 15 utilize an esterification catalyst. The catalyst should be present in sufficient amount to catalyze the reaction and typically will be present at a level of at least about .01%, and normally from about .05% to about 3.0%, based upon the weight of the cyclic anhydride. Catalysts which are useful in the esterification reaction of the anhydride with the hydroxy-functional molecule include mineral acids such as hydrochloric acid and sulfuric acid; alkali metal hydroxides such as sodium 20 hydroxide; tin compounds such as stannous octoate, or dibutyltin oxide; aliphatic or aromatic amines, especially tertiary alkyl amines, such as triethylamine; and aromatic heterocyclic amines 213937g such as N-methyl imidazole and the like. Especially preferred are N-methyl imidazole and triethylamine.
Although the reaction between the hydroxy-functional compound and the anhydride can be conducted in the absence of solvent if the materials are liquid at the reaction temperature, it 5 is normally preferred to conduct the reaction in the presence of an inert solvent such as esters, ketones, ethers or aromatic hydrocarbons.. If desired, the acid-functional molecule can be utilized as the solvent solution, or, optionally, all or part of the inert solvent may be removed, e.g. by distillation, after the reaction is completed.
After the reaction is completed, it is frequently desirable to add a low molecular weigllt 10 alcohol solvent, such as isobutanol or isopropanol, to the acid-functional compound at a level of about 5 to 35 percent by weight to provide stabilization on storage.

2.B. Carboxylic Acid-Functional Polymers Prepared From Unsaturated Acid-Functional Monomers.
Useful acid-functional polymers can also be conveniently routinely prepared by the free radical addition polymerization of unsaturated acids such as maleic acid, acrylic acid, methacrylic acid, crotonic acid, etc. along with one or more unsaturated monomers.
Representative monomers include the esters of unsaturated acids, vinyl compounds, styrene-based materials, allyl compounds and other copolymerizable monomers as representatively taught 20 . in Section 2.A.5. of this specification. The monomers which are co-polymerized with the unsaturated acid should be free of any functionality which could react with the acid groups dur-ing the polymerization.

2.C. Carboxylic Acid-Functional Polymers Prepared From Polyols and Polyacids.
Other useful acid-functional polymers include polyester polymers obtained from the 5 reaction of one or more aromatic and/or aliphatic carboxylic acids or their anhydrides and one or more aliphatic and/or aromatic polyols wherein the acid functionality is present in a stoichiometric excess over the hydroxy functionality. Representative carboxylic acids and polyols include those listed in Section 2.A.2. of this specification.
3. EPOXY-FUNCTIONAL COMPOUNDS.
The curable coatings of this invention may also incorporate at least one epoxy-functional compound. The epoxy compounds can, if there are sufficient other reactive materials to provide crosslinking, be monoepoxies or, preferably, a polyepoxide having an average of at least t~o epoxy groups per molecule.
Representative useful monoepoxides include the monoglycidyl ethers of aliphatic or 15 aromatic alcohols such as butyl glycidyl ether, octyl glycidyl ether, nonyl glycidyl ether, decyl glycidyl ether, dodecyl glycidyl ether, p-tert-butylphenyl glycidyl ether, and o-cresyl glycidyl ether. Monoepoxy esters such as the glycidyl ester of versatic acid (commercially available as CARDURA~ E from Shell Chemical Company), or the glycidyl esters of other acids such as tertiary-nonanoic acid, tertiary-decanoic acid, tertiary-undecanoic acid, etc. are also useful.
20 Similarly, if desired, unsaturated mono;epoxy esters such as glycidyl acrylate, glycidyl methacry-late or glycidyl laurate could be used. Additionally, monoepoxidized oils can also be used.
Other useful monoepoxies include styrene oxide, cyclohexene oxide, 1,2-butene oxide, 2,3-butene oxide, 1,2-pentene oxide, 1,2-heptene oxide, 1,2-octene oxide, 1,2-nonene oxide, 1,2-decene oxide, and the like.

It is only necessary that the monoepoxide compounds have a sufficiently low volatility to remain in the coating composition under the applicable conditions of cure.
Polyepoxides are especially preferred in the reactive coatings of this invention.
Especially preferred as the poly-functional epoxy compounds, due to their reactivity and 5 durability, are the polyepoxy-functional cycloaliphatic epoxies. Preferably, the cycloaliphatic epoxies will have a number average molecular weight less than about 2,000 to minimize tlle viscosity. The cycloaliphatic epoxies are conveniently prepared by methods well known in the art such as epoxidation of dienes or polyenes, or the epoxidation of unsaturated esters by reaction with a peracid such as peracetic and/or performic acid.
10Commercial examples of representative preferred cycloaliphatic epoxies include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (e.g. "ERL-4221" from Union Carbide Corp.); bis(3,4-epoxycyclohexylmethyl)adipate (e.g. "ERL-4299" from Union Carbide Corporation); 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate (e.g. "ERL-4201" from UnionCarbideCorp.); bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate 15(e.g. "ERL-4289" from Union Carbide Corp.); bis(2,3-epoxycyclopentyl) ether (e.g. "ERL-0400" from Union Carbide Corp.); dripentene dioxide (e.g. "ERL-4269" from Union Carbide Corp.); 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-metadioxane (e.g. "ERL-4234"
from Union Carbide Corp.). Other cornrnercially available cycloaliphatic epoxies are available from Ciba-Geigy Corporation such as CY 192, a cycloaliphatic diglycidyl ester epoxy resin 20 having an epoxy equivalent weight of about 154. The manufacture of representative cyclo-aliphatic epoxies is taught in various patents including U.S. 2,884,408, 3,027,357 and 3,247,144.

Other polyepoxides potentially useful in the practices of this invention include aliphatic and aromatic polyepoxies, such as those prepared by the reaction of an aliphatic polyol or polyhydric phenol and an epihalohydrin. Other useful epoxies include epoxidized oils and epoxy-functional copolymers such as acrylic polymers derived from ethylenically unsaturated epoxy-functional monomers such as glycidyl acrylate or glycidyl methacrylate in combination with other copolymerizable monomers such as those listed in 2.A.5 above.

4. HYDROXY-FUNCTIONAL COMPOUNDS
The hydroxy-functional compounds which are useful in combination with the anl~ydride-functional polymers to prepare curable compositions in the practice of this invention sl1ould have an average of at least two hydroxyl groups per molecule. Although low molecular weight diols and polyols such as propylene glycol, 1;6-hexanediol, triethanol amine and pentaerythritol can be utilized in the practice of this invention, it is especially preferred to utilize polymeric hydroxy-functional compounds such as polyethers, polyesters, acrylics, polyurethanes, polycaprolactones, etc.
Preferably the hydroxy-functional polymer will have a number average molecular weight of at least about 400. Typical number average molecular weights will range from about 400 to about 30,000, and especially 1,000 to about 15,000. In order to provide the fastest rate of reaction during cure it is preferred to utilize hydroxy-functional compounds having predominant-ly, and preferably ali, primary hydroxy functionality.
Representative hydroxy-functional polymers are taught in Sections 2 . A. 1. through 2 . A . 5 .
Especially preferred as the hydroxy-functional polymer is a hydroxy-functional polymer com-prising the addition polymerization of (a) 10 to about 60 weight percent of a hydroxy-functional ..

ethylenically unsaturated monomer and (b) 40 to about 90 weight percent of at least one ethylen-ically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

5. AMINE-FUNCTIONAL COMPOUNDS
Amine-Functional compounds which are useful in combination with the anhydride-5 functional polymers to prepare curable compositions in the practice of this invention should havean average of at least two primary or secondary amine groups per molecule. Polyamines can be prepared by methods well known in the art such as by the free radical polymerization of acrylic or other unsaturated monomers having primary or secondary amine functionality, or by the reaction of amines having at least two amine groups per molecule with a polycarobxylic acid 10 to form polyamide amines, or by the reaction of primary amines with epoxy materials to produce secondary amine and hydroxyl functionality. The polyamines can be polymeric, typically having a number average molecular weight over 400, or lower molecular materials, such as piperazine, tetraethylenepentamine, 1,2-diaminopropane, 1,6-diaminohexane, etc. Also useful are the materials having a primary or secondary amine group and a hydroxyl group such as isopropanol 15 amine, isobutanol amine, ethanol amine, etc.
The ratios of anhydride to other functional groups in the curable compositions can be widely varied within the practice of this invention as long as at least some of each group is present in the reactive composition. It is only necessary to combine the anhydride-functional polymer and other reactive materials in amounts to provide the desired degree of crosslinking 20 upon cure. When the anhydride-functional polymer is used as one component, and a polyol or polyamine or polyepoxide is used as the only other reactive component in the curable composition, it is preferred to provide about 0.3 to about 10 hydroxyl or amine or epoxy groups 21~9379 .
.. ..

for each anhydride group, and especially 1 to about 5 hydroxyl or amine or epoxy groups for each anhydride group. When the curable composition involves a combination of only the anhydride-functional polymer, an epoxide or polyepoxide, and a polyol it is preferred to provide 0.3 to about 6.0 hydroxyl groups, and about 0.3 to about 6.0 epoxy groups for each anhydride group, and especially to provide 0.5 to 2.5 hydroxyl groups and 0.5 to 2.5 epoxy groups for each anhydride group. When the curable composition involves the anhydride-functional polymer, an acid-functional compound and a polyepoxide, it is preferred to provide 0.3 to 6.0 acid groups and 0.6 to 12.0 epoxy groups for each anhydride group, and especially 2.0 to about 5.0 acid groups and 3.0 to about 8.0 epoxide groups for eacl1 anhydride group. If the reactive curable composition comprises the anhydride-functional polymer, an acid-functional compound, an epoxide or polyepoxide, and a hydroxy-functional compound, it is preferred to provide from 0.05 to about 3.0 acid groups and about 0.5 to about 4.0 epoxy groups and about 0.05 to 6.0 hydroxyl groups for each anhydride group in the reactive system. It is especially preferred to provide 1.0 to about 2.0 acid groups and 1.0 to about 3.0 epoxy groups and about 1.0 to about 4.0 hydroxyl groups for each anhydride group.
The curable compositions of this invention can be cured at temperatures ranging from about room temperature up to about 350F. When the curable compositions are utilized as coatings, the coatings can be used as clear coatings or they may contain pigments as is ~vell known in the art. Representative opacifying pigments include white pigments such as titanium dioxide, zinc oxide, antimony oxide, etc. and organic or inorganic chromatic pigments such as iron oxide, carbon black, phthalocyanine blue, etc. The coatings may also contain extender pigments such as calcium carbonate, clay, silica, talc, etc.

'` ,' 213937g The coatings may also contain other additives such as flow agents, catalysts, diluents, solvents, ultraviolet light absorbers, etc.
- It is especially preferred in the curable compositions of this invention to include a catalyst for the reaction of anhydride groups and hydroxyl groups and/or a catalyst for the reaction of 5 epoxy and acid groups, if present in the curable composition. It is especially preferred in the practice of this invention to utilize tertiary amines and especially N-methylimidazole as a catalyst for the anhydride/hydroxyl reaction. The catalyst for the anhydride/hydroxyl reaction will typically be present at a level of at least 0.01% by weight of the anhydride compound and preferably 1.0 to about 5.0%.
Tertiary amines, secondary amines such as ethyl imidazole, quaternary ammonium salts, nucleophilic catalysts, such as lithium iodide, phosphonium salts, and phosphines such as tri-phenyl phosphine are especially useful as catalysts for epoxy/acid reactions. The catalyst for - the epoxy/acid reaction will typically be present at a level of at least 0.01% by weight of the total acid-functional compound and epoxy-functional compound and will be present a~ 0.1 to 15 about 3.0%.
Since the curable compositions of this invention are typically provided as multi-package systems which must be mixed together prior to use, the pigments, catalysts and other additives can be conveniently added to any or all of the appropriate individual packages.

.
The coatings of this invention may typically be applied to any substrate such as metal, 20 plastic, wood, glass, synthetic fibers, etc. by brushing, dipping, roll coating, flow coating, spraying or other method conventionally employed in the coating industry.

213~37~

One preferred application of the curable coatings of this invention relates to their use as clearcoats and/or basecoats in clearcoat/basecoat formulations.
Clearcoat/basecoat systems are well known, especially in the automobile industry where it is especially useful to apply a pigmented basecoat, which may contain metallic pigments, to 5 a substrate and allow it to form a polymer film followed by the application of a clearcoat W}liCh will not mix with or have any appreciable solvent attack upon the previously applied basecoat.
Typically, at least some of the solvent will be allowed to evaporate from the basecoat prior to the application of the clearcoat. In some applications the basecoat may even be allowed to cure, at least partially, prior to application of the clearcoat. The basecoat composition may be any 10 of the polymers known to be useful in coating compositions including the reactive compositions of this invention.
One useful polymer basecoat includes the acrylic addition polymers, particularly polymers or copolymers of one or more alkyl esters of acrylic acid or methacrylic acid, optionally together with one or more other ethylenically unsaturated monomers. These polymers may be of either 15 the thermoplastic type or the thermosetting, crosslinking type which contain hydroxyl or amine or other reactive functionality which can be crosslinked. Suitable acrylic esters for either type of polymer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, vinyl acetate, acrylonitrile, acrylamide, etc. Where the polymers are required to be of the crosslinking type; suitable functional monomers which 20 can be used in addition to those already mentioned include acrylic or methacrylic acid, hydroxy ethyl acrylate, 2-hydroxy propyl methacrylate, glycidyl acrylate, tertiary-butyl amino ethyl methacrylate, etc. The basecoat composition may, in such a case, also contain a crosslinking ~139373 agent such as a carbodiimide, a polyanhydride, a polyisocyanate, a polyepoxide, or a nitrogen resin such as a con~len.cate of an aldehyde such as formaldehyde with a nitrogenous compound such as ureaj melamine or benzogll~n~mine or a lower alkyl ether of such a condensate. Other polymers useful in the basecoat composition include vinyl copolymers such as copolymers of 5 vinyl esters of inorganic or organic acids, such as vinyl chloride, vinyl acetate, vinyl propionate, etc., which copolymers may optionally be partially hydrolyzed so as to introduce vinyl alcohol units.
Other polymers useful in the manufacture of the basecoat include alkyd resins- or polyesters which can be prepared in a known maMer by the condensation of polyhydric alcohols 10 and polycarboxylic acids, with or without the inclusion of natural drying oil fatty acids as described elsewhere in this specification The polyesters or alkyds may contain a proportion of free hydroxyl and/or carboxyl groups which are available for reaction, if desired Wit}l suitable crosslinking agents as discussed above.
If desired, the basecoat composition may also contain waxes, rheology modifiers, 15 cellulose esters, or other additives to alter the appearance, drying or viscosity charaeteristics of the basecoat. r Typically, the basecoat will include pigments conventionally used for coating compositions and after being applied to a substrate, which may or may not previously have been primed, the basecoat will norrnally be allowed sufficient time to form a wet polymer film which 20 will not be lifted during the application of the clearcoat. The clearcoat is then applied to the surface of the basecoat, and the system can be allowed to dry or, if desired, can be force dried by baking the coated substrate at temperatures typically ranging up to about 250F.

21~9~73 .
Typically, the clearcoat may contain ultraviolet light absorbers or stabilizers, such as hindered phenols or hindered amines at a level ranging up to about 6% by weight of the vehicle - solids. The clearcoat can be applied by any application Method known in the art, but preferably will be spray applied. If desired, multiple layers of basecoat and/or clearcoat can be applied.
5 Typically, both the basecoat and the clearcoat will each be applied to give a dry film thickness of about 0.01 to about 6.0, and especially about 0.5 to about 3.0 mils.
The following examples have been selected to illustrate specific embodiments and practices of advantage to a more complete understanding of the invention. Unless otherwise stated, "parts" means parts-by-weight, "percent" is percent-by-weight and molecular ~veight is lO based on GPC versus polystyrene standard.

2-(3-Bromopropvl)-Succinic Anhvdride A cooled (10C; ice/water) solution of 1200g (8.56 mol) allyl succinic anhydride, 6500 ml of toluene (dried over MgSO4), and 6.3g of dibenzoyl peroxide in 100 ml of toluene was stirred under a nitrogen atmosphere., Next, hydrogen bromide gas was bubbled in (volatile cont~ in~n~c and water condensed out of the gas by cooling a cold trap to -23C with CCl,/dry ice bath) at a constant rate such that the reaction mixture absorbed all incoming hydrogen bro-mide (HBr) gas. After about two hours, an additional 2.0 grams, and again approxirnately two 20 hours later 1.0 grams of dibenzoyl peroxide were added after the reaction temperature increased to about 15C. A shiny beige solid formed as hydrogen bromide bubbling continued. The 213~37~

mixture was allowed to warm to room temperature. Shortly thereafter, FT-infrared analysis indicated e~senti~lly all of the vinyl groups were consumed, and the reaction was stopped.
Filtrating and drying the reaction mixture yielded I533.5g (81.0%) of beige solid bromopropyl succinic anhydride having a melting point of 91-92.5C. Cryst~11i7~tion of the solid from toluene (5g solid/25g toluene) gave 1275g (67.3% yield) of beige needles having a meltlng point of 92-94C. The material was characterized by FT-infrared and lH NMR to be the desired 2-(3-bromopropyl)-succinic anhydride. The filtrate from the crystals was concen-trated to give an additional 119.2g (6.3 %) of dried bromopropyl anhydride beige crystals having a melting point of 89.5-92.5C.

2-(3-Methacrvloxvpropvl)-Succinic Anhvdride To a room tempeMture solution of 0.12g of butylated hydroxy toluene, 55.0g (0.638 moles) of methacrylic acid in 440 ml of toluene, and 57.2g (0.565 moles) of triethylamine in 440 ml of toluene prepared under nitrogen, was added 110g of the 2-(3-bromopropyl)-succinic anhydride of Example 1. The reaction was then stirred and heated at 100C for 12.5 hours.
The reaction was then cooled to 40C and 11.00g (0.127 moles) of methacrylic acid and 11.44g (0.113 moles) of triethylamine were added to the 9ask and heated to 100C. Heating at 100C

was continued for an additional 6.5 hours. Progress of the reaction was followed by monitoring the intensity of the infrared C-O band for the methacrylate ester at ~ 1168 cm-l.
The reaction mixture was then filtered and the collected salt was washed with toluene.
The combined toluene filtrates were then washed with 500 ml of aq. NaCl solution, 3 x 1000 ml of an 4:1.5 (volume ratio) sat. NaCI/sat. NaHCO3 solution, and a final washing with sat.
NaCl solution, and then dried over MgSO4. The volatiles were removed to give 76.49g (68%) of a light brown liquid which was characterized by FT-infrared and NMR as the desired 2-(3-methacryloxypropyl)-succinic anhydride.

2-(3-Methacrvloxypropvl)-Succinic Anhvdride Potassium methacrylate was prepared by the dropwise addition of a solution of 16.29 grams potassium hydroxide in 50 mls methanol into a solution of 25 grams methacrylic acid in 25 mls methanol. The reaction mixture was maintained at between 10C and 15C. The white solid precipitate of potassium methacrylate was filtered and washed with anhydrous ether and then dried. A heterogeneous mixture of 2.88g (0.0232 mol) of the potassium methacrylate was then dispersed in 20 ml of dried toluene (MgSO4),- ~.OSOg (0.000219 mol) of benzyl triethyl ammonium chloride and a small amount of butylated hydroxy toluene inhibitor was prepared lS under nitrogen in dried glassware. Next, a heated solution of 5g (0.02262 mol) of 2-(3-bromopropyl)-succinic anhydride in 25 ml of dried toluene was added to the potassium meth--acrylate/benzyl triethyl ammonium chloride/toluene mixture at 80C over about 10 minutes.
Heating was con~inue~1 at 80C for one hour. Approximately 0.08g (0.000206 mol) of benzyl triphenyl phosphonium chloride was then added. Heating was m~int~ined at 90C for 3 hours, 20 giving a redder reaction mixture.
The reaction mixture was cooled to room temperature and then filtered and the collected salt was washed with 30 ml of toluene. The toluene solutions were combined and the solution . 213~373 , .
was washed twice with 50 ml of a 4:1.5 (volume ratio) sat. NaCl/sat. NaHCO3 solution, 75 ml of sat. NaCl, and then dried (MgSO~). Volatiles were removed to give 2.73g (53.3 % of theory) of a brown liquid which was confirmed to be the desired 2-(3-methacryloxypropyl)-succinic anhydride.

s 2-(3-Methacrvloxvpropvl)-Succinic Anh~dride Into a dried glassware setup were charged 2.88g (0.0232 mol) of potassium methacrylate dispersed in 30 ml of dried toluene (MgSO4), a small amount of butylated hydroxy toluene in-hibitor, 5g (0.02262 mol) of 2-(3-bromopropyl)-succinic anhydride and 15 ml of toluene. Next, 0.050g (0.000219) of benzyl triethyl amrnonium chloride was added to the reaction mixture an~
heated to 100C under a nitrogen atmosphere for 6 hours.
The reaction mixture was then cooled and filtered. The collected salt was washed with toluene and the combined toluene layers were dried (MgSO.,). A small amount of butylated hydroxy toluene was added. Volatiles were removed to give 4.54g (90.8% of theory) of a brown liquid confirmed to be the desired anhydride-functional methacrylate by FT-infrared and lH NMR.

2-(3-Methacrvloxvpropyl)-Succinic Acid A suspension of approximately 2.5g (0.0110 mol) of the 2-(3-methacryloxypropyl)-succinic anhydride from Example 3, 15 ml of toluene, a catalytic amount of butylated hydroxy 213937~

toluene and 7 ml of deionized water was stirred under nitrogen. The reaction mixture was heated to 100C under a nitrogen atmosphere. An additional 3 ml of water was added over 10 minlltes at reflux and the mixture was then held at reflux for 2 hours and then allowed to cool to room temperature.
The cooled reaction mixture was washed witll sat. NaCI solution and then dried (MgSO.,).
Butylated hydroxy toluene was added, and the volatiles were removed to give 2.87g (106~ of theory) of a light tan solid. This material was characterized by FT-infrared and lH NMR to be the desired 2-(3-methacryloxypropyl)-succinic acid.

Anhydride Monomer/EA/ST Copolymer A flask was charged with 136.4g of metllyl isobutyl ketone. Next, a monomer and initiator solution of 72.9g (0.3223 mol) of the 2-(3-methacryloxypropyl)-succinic anhydride of Example 2, 63.5g (0.634 mol) of ethyl acrylate, 30.6g (0.2938 mol) of styrene, 14.7g (0.0696 mol) of Vazo~ 67 (azobis(isobutyronitrile)) imtiator, and 34. lg of methyl isobutyl ketone was added at 93C over a 3 hour period. After complete addition, the mixture was held at 93C for 15 minutes, after which an additional 0.156g of Vazo 67 initiator was added and the mixture was held at 93C for 15 minlltes. Lastly, 0.156g of Vazo 67 initiator was added and the mixture was again held at 93C for 30 mimltes. The anhydride functional polymer product was then cooled to room temperature and characterized as having an anhydride equivalent weight of 551.5 (theoretical 526); a % NVM of 48.9; a weight per gallon of 8.00 Ib/gal; and a glass transition 213~373 ;

temperature (Tg) of 36C. The number average molecular weight (Mn) and polydispersity (Pd) were 3257 and 1.8, respectively.

S Preparation of Clear Coating A curable, two-package, clear coating having a ratio of anhydride groups/hydro~;y groups/epoxy groups of 2/1/2 was prepared according to the followillg recipe:
Packa~e 1 Raw Material Parts-Bv-Wei~ht Anhydride-Functional Polymer of Example 6 496.23 Packa~e 2 Hydroxy-Functional Acrylic Polymer' 150.43 ERL 42292 88.00 Solvent Blend3 30.62 Byk 3004 2.5 Tinuvin 2925 9.01 20% N-methylimidazole in Methyl Isobutyl Ketone 42.47 Packages 1 and 2 were mixed together and this coating was reduced with suitable solvents and spray applied over a basecoat/primer system coated on Bonderite~-1000 panels (iron phosphate treatment on cold rolled steel). The basecoat/primer system consisted of basecoat (Ultra Base 7~ Metallic Basecoat, commercially available from The Sherwin-Williams Company) and a primer (Q-Seal~ primer PlA60 commercially available from The Sherwin-Williams Com-pany). The dry film thicknesses were approximately one mil for primer, one mil for basecoat and two mils for clear coat. The coating system was allowed to cure twenty-four (24) hours under ambient conditions prior to initial testing. The cured panels exhibited a 20 gloss of 71, lCopolymer of hydroxy ethyl methacrylate/hydroxy ethyl acrylate/styrene/methyl methacry-late/butyl methacrylate/butyl acrylate/ethyl hexyl acrylate in a weight ratio of 20/11.2/16/14/
14112.81616 extended with two moles of caprolactone per mole of hydroxyl and reduced to 807O
NVM. The polymer had a hydroxyl equivalent weight of 544.3, a number average molecular weight (GPC) of 3200 and a weight per gallon of 8.73.
2Tra~lem~rk of Union Carbide for bis(3,4-epoxycyclohexylmethyl)adipate.
3n-butyl acetate/propylene glycol monomethyl ether acetate/ ethyl 3-ethoxypropionate/
dimethyl glutarate in a 65.5/10.6/16.7/7.2 weight ratio.
4Flow control agent sold by Byk-Malinkrodt.
5Trademark of Ciba-Geigy for di[4(2,2,6,6-tetramethyl piperdinyl)]sebacate light stabilizer.

213~373 ;

.

a konig pendulum hardness (KPH) of 23 after four (4) weeks, and excellent resistance to methyl ethyl ketone and gasahol after four (4) days of air dry cure.

Preparation of Clearcoat A curable, two-package, clear coating, having a ratio of anhydride groups/hydroxyl groups/epoxy groups of 2/112 was prepared according to the following recipe:
Packa e 1 Raw Materials Pal ts-Bv-Wei~ht Anhydride-Functional Polymer of Example 6 290.9 Packa~e 2 Hydroxy-Functional Resin6 151.3 ERL 4229 51.6 Solvent Blend7 269.31 Byk 300 2 .5 Tinuvin 292 5.66 20% N-methylimidazole in Methyl Isobutyl Ketone - 24.9 Packages 1 and 2 were mixed together and this coating was reduced with suitable solvents spray applied and allowed to cure as described in Example 11. The cured panels exhibited a 20 6Acrylic polymer of styrene/methyl methacrylatetbutyl acrylate/Tone~ M-100 hydroxy-functional caprolactone adduct/hydroxy ethyl acrylate in a weight ratio of 37.5/12.5/15/27.5/7.5.
307Same as Example 7 solvent blend.

gloss of 88, a konig pendulum hardness (KPH) of 29 after four (4) weeks, and excellent resistance to methyl ethyl ketone and gasahol after four (4) days of air dry cure.

Preparation of Colored Base Coat A curable, two-package, pigmented coating, which could be suitable as a pigmented topcoat or as a basecoat, and having one anhydride group per two hydroxyl groups could be prepared according to the follo~ving recipe:
Packa~e 1 Ra~v Materials Parts-Bv-Wei~ht Anhydride-Functional Polymer of Example 6 34.80 Packa~e 2 Hydroxy-Functional Resin8 36.18 Non-Leafing Alllminum Paste Reynolds 5-10 AV 27.32 Methylethylketone 12 . 9 Toluene 12.9 N-methyl imidazole 0 . 9 ..
The two packages can be mixed together, reduced to a suitable spraying viscosity and applied as a curable two-package pigmented coating.

8Same as used in Example 8.

Other reactive systems, such as the combination of a polyepoxy-functional material, an acid functional material and the anhydride-functional polymer of this invention are also practical, and could, optionally, also incorporate hydroxy-functional materials as well.
While this invention has been described by a specific number of embodiments, it is 5 obvious that other variations and modifications may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims (91)

1. An anhydride-functional polymer which comprises the polymerization reaction product of:
(i) an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each hydrogen or methyl; and optionally, (ii) at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

2. The anhydride-functional polymer of claim 1 wherein the polymer comprises the free radical addition polymerization reaction product of a monomer mixture comprising 5 to 100% by weight of the anhydride-functional monomer and 0 to 95% by weight of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

3. The anhydride-functional polymer of claim 1 wherein R1 is hydrogen.

4. The anhydride-functional polymer of claim 1 wherein R1 is methyl.

5. The anhydride-functional polymer of claim 1 wherein at least one of the unsaturated monomers is ethyl acrylate.

6. The anhydride-functional polymer of claim 4 wherein R2, R3 and R4 are each hydrogen.

7. The anhydride-functional polymer of claim 1 wherein the polymer comprises the free-radical addition polymerization product of:
(i) 5 to 75 weight percent of the anhydride-functional monomer;
(ii) 25 to 95 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 70 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

8. The anhydride-functional polymer of claim 1 wherein the polymer comprises the free-radical addition polymerization product of:
(i) 15 to 50 weight percent of the anhydride-functional monomer;
(ii) 50 to 85 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 35 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

9. The anhydride-functional polymer of claim 7 or 8, wherein R2, R3 and R4 are each hydrogen and R1 is hydrogen or methyl in the anhydride-functional monomer.

10. The anhydride-functional polymer of claim 7 or 8, wherein the (meth)acrylic monomer is at least one member selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, ethylhexyl acrylate, amyl acrylate, 3,5,5-trimethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobornyl methacrylate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide and methacrylamide.

11. The anhydride-functional polymer of claim 10, wherein the other unsaturated monomer when used is at least one member selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl m-chlorobenzoate, vinyl p-methoxy benzoate, vinyl chloride, styrene, .alpha.-methyl styrene and maleic anhydride.

12. The anhydride-functional polymer of claim 11, wherein the anhydride-functional monomer is 2-(3-methacryloxypropyl)-succinic anhydride.

13. The anhydride-functional polymer of claim 11, wherein the (meth)acrylic monomer is ethyl acrylate and the other unsaturated monomer is used and is styrene.

41a

14. A process of preparing an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each individually hydrogen or methyl; which process comprises the steps of:
(i) admixing under reaction conditions (a) a halogenated alkyl succinic anhydride; and (b) a (meth)acrylic acid or acid salt; and (ii) maintaining the reaction mixture at a sufficient temperature to provide the anhydride product.

15. The process of claim 14 wherein the halogenated alkyl succinic anhydride is 2-(3-bromopropyl)-succinic anhydride.

16. A curable composition which comprises:
(i) an anhydride-functional polymer which comprises the polymerization reaction product of:
(a) an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each hydrogen or methyl; and, optionally (b) at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer; and (ii) a compound having an average of at least two functional groups per molecule which are reactive with anhydride groups.

17. The curable composition of claim 16 wherein R2, R3 and R4 are each hydrogen.

18. The curable composition of claim 16 wherein the anhydride-functional polymer comprises the free radical addition polymerization product of a monomer mixture comprising 5 to 100% by weight of the anhydride-functional monomer and 0 to 95% by weight of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

19. The curable composition of claim 16 wherein the anhydride-functional polymer comprises the free-radical addition polymerization product of:
(i) 5 to 75 weight percent of the anhydride-functional monomer; and (ii) 25 to 95 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 70 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

20. The curable composition of claim 16 wherein the anhydride-functional polymer comprises the free-radical addition polymerization product of:
(i) 15 to 50 weight percent of the anhydride-functional monomer; and (ii) 50 to 85 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 35 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

21. The curable composition of claim 16 wherein the compound having an average of at least two functional groups per molecule reactive with anhydride groups is a polyamine.

22. The curable composition of claim 16 wherein the compound having an average of at least two functional groups per molecule reactive with anhydride is a hydroxy-functional compound.

23. The curable composition of claim 22 wherein the anhydride-functional polymer and the hydroxy-functional compound are each present at a level to provide 0.3 to about 10 hydroxyl groups for each anhydride group.

24. The curable composition of claim 22 wherein the hydroxy-functional compound is a hydroxy-functional polymer.

25. The curable composition of claim 24 wherein the hydroxy-functional polymer comprises the addition polymerization reaction product of:
(i) 10 to about 60 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 40 to about 90 weight percent of at least one ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

26. The curable composition of claim 22 wherein the composition also comprises a catalyst for reaction of hydroxy groups and anhydride groups.

27. The curable composition of claim 22 wherein the composition also comprises an epoxy-functional compound having an average of at least one epoxy group per molecule.

28. The curable composition of claim 27 wherein the anhydride-functional polymer, the hydroxy-functional compound, and the epoxy-functional compound are each present at a level to provide 0.3 to about 6.0 hydroxyl groups, and about 0.3 to about 6.0 epoxy groups for each anhydride group.

29. The curable composition of claim 27 wherein the epoxy-functional compound is a monoepoxide.

30. The curable composition of claim 27 wherein the epoxy-functional compound is a polyepoxide having an average of at least two epoxy groups per molecule.

31. The curable composition of claim 30 wherein the polyepoxide is a cycloaliphatic polyepoxide.

32. The curable composition of claim 30 wherein the polyepoxide is a copolymer obtained by the copolymerization of an ethylenically unsaturated epoxy-functional monomer and at least one other copolymerizable ethylenically unsaturated monomer.

33. The curable composition of claim 27 wherein the composition also comprises an acid-functional compound having an average of at least two carboxylic acid groups per molecule.

34. The curable composition of claim 33 wherein the composition also comprises a catalyst for the reaction of hydroxy groups and anhydride groups and a catalyst for the reaction of epoxy groups and acid groups.

35. The curable composition of claim 33 wherein the acid-functional compound is an acid-functional polymer.

36. The curable composition of claim 35 wherein the acid-functional polymer is prepared by the half-ester opening of a cyclic anhydride by reaction with a hydroxy-functional polymer.

37. The curable composition of claim 36 wherein the hydroxy-functional polymer is the addition polymerization reaction product of:
(i) 5 to 100 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 0 to 95 weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

38. The curable composition of claim 33 wherein the anhydride-functional polymer, the hydroxy-functional compound, the acid-functional compound and the epoxy-functional compound are each present at a level to provide 0.05 to about 3.0 acid groups and about 0.5 to about 4.0 epoxy groups an about 0.05 to about 6.0 hydroxyl groups for each anhydride group.

39. A curable composition which comprises:
(i) an anhydride-functional polymer which comprises the polymerization reaction product of:
(a) an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each individually hydrogen or methyl; and, optionally, (b) at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer; and (ii) an acid-functional compound having an average of at least two carboxylic acid groups per molecule; and (iii) an epoxy-functional compound.

40. The curable composition of claim 39 wherein R2, R3 and R4 are each hydrogen.

41. The curable composition of claim 39 wherein the anhydride-functional polymer comprises the free radical addition polymerization product of a monomer mixture comprising 5 to 100% by weightof the anhydride-functional monomer and 0 to 95% by weight of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

42. The curable composition of claim 39 wherein the anhydride-functional polymer comprises the free radical additional polymerizable product of:
(i) 5 to 75 weight percent of the anhydride-functional monomer; and (ii) 25 to 95 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 70 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

43. The curable composition of claim 39 wherein the anhydride-functional polymer comprises the free radical additional polymerizable product of:
(i) 15 to 50 weight percent of the anhydride-functional monomer; and (ii) 50 to 85 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 35 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

44. The curable composition of claim 39 wherein the acid-functional compound is an acid-functional polymer.

45. The curable composition of claim 44 wherein the acid-functional polymer is prepared by the half-ester opening of a cyclic anhydride by reaction with a hydroxy-functional polymer.

46. The curable composition of claim 45 wherein the hydroxy-functional polymer is the addition polymerization reaction product of:
(i) 5 to 100 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 0 to 95 weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

47. The curable composition of claim 39 wherein the epoxy-functional compound is a monoepoxide.

48. The curable composition of claim 39 wherein the epoxy-functional compound is a polyepoxide having an average of at least 2 epoxy groups per molecule.

49. The curable composition of claim 48 wherein the polyepoxide is a cycloaliphatic polyepoxide.

50. The curable composition of claim 48 wherein the polyepoxide is a copolymer obtained by the copolymerization of an ethylenically unsaturated epoxy-functional monomer and at least one other copolymerizable ethylenically unsaturated monomer.

51. The curable composition of claim 39 wherein the anhydride-functional polymer and the acid-functional compound and the epoxy-functional compound are each present at a level to provide 0.3 to about 6.0 acid groups and 0.6 to 12.0 epoxy groups for each anhydride group.

52. The curable composition of claim 39 wherein the composition also comprises a catalyst for the reaction of acid groups and epoxy groups and a catalyst for the reaction of anhydride groups and hydroxyl groups.

53. In a substrate coated with a multi-layer decorative and/or protective coating which comprises:
(i) a basecoat comprising a pigmented film-forming polymer; and (ii) a transparent clearcoat comprising a film-forming polymer applied to the surface of the basecoat composition;
the improvement which comprises utilizing as the clearcoat and/or the basecoat a multi-component curable composition which is reactive upon mixing of the components, wherein the multi-component curable composition comprises:
(i) an anhydride-functional polymer which comprises the polymerization which comprises the polymerization reaction product of:
(a) an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each individually hydrogen or methyl; and, optionally, (b) at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer; and (ii) a hydroxy-functional compound having an average of at least two hydroxyl groups per molecule.

54. The coated substrate of claim 53 wherein R2, R3 and R4 are each hydrogen.

55. The coated substrate of claim 53 wherein the anhydride-functional polymer comprises the free radical polymerization reaction product of a monomer mixture comprising 5 to 100%
by weight of the anhydride-functional monomer and 0 to 95% by weight of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

56. The coated substrate of claim 53 wherein the anhydride-functional polymer comprises the free-radical addition polymerization product of:
(i) 5 to 75 weight percent of the anhydride-functional monomer; and (ii) 25 to 95 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 70 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

57. The coated substrate of claim 53 wherein the anhydride-functional polymer comprises the free-radical addition polymerization reaction product of:
(i) 15 to 50 weight percent of the anhydride-functional monomer; and (ii) 50 to 85 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 35 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

58. The coated substrate of claim 53 wherein the anhydride-functional polymer and the hydroxy-functional compound are each present at a level to provide 0.3 to about 10 hydroxyl groups for each anhydride group.

59. The coated substrate of claim 53 wherein the hydroxy-functional compound is a hydroxy-functional polymer.

60. The coated substrate of claim 59 wherein the hydroxy-functional polymer comprises the addition polymerization reaction product of:
(i) 10 to about 60 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 40 to about 90 weight percent of at least one ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

61. The coated substrate of claim 53 wherein the curable composition also comprises a catalyst for reaction of hydroxy groups and anhydride groups.

62. The coated substrate of claim 53 wherein the curable composition also comprises an epoxy-functional compound having an average of at least one epoxy group per molecule.

63. The coated substrate of claim 62 wherein the anhydride-functional polymer, the hydroxy-functional compound, and the epoxy-functional compound are each present in the curable composition at a level to provide 0.3 to about 6.0 hydroxyl groups, and about 0.3 to about 6.0 epoxy groups for each anhydride group.

64. The coated substrate of claim 62 wherein the epoxy-functional compound is a monoepoxide.

65. The coated substrate of claim 62 wherein the epoxy-functional compound is a polyepoxide having an average of at least two epoxy groups per molecule.

66. The coated substrate of claim 65 wherein the polyepoxide is a cycloaliphatic polyepoxide.

67. The coated substrate of claim 65 wherein the polyepoxide is a copolymer obtained by the copolymerization of an ethylenically unsaturated epoxy-functional monomer and at least one other copolymerizable ethylenically unsaturated monomer.

68. The coated substrate of claim 62 wherein the curable composition also comprises an acid-functional compound having an average of at least two carboxylic acid groups per molecule.

69. The coated substrate of claim 68 wherein the curable composition also comprises a catalyst for the reaction of hydroxy groups and anhydride groups and a catalyst for the reaction of epoxy groups and acid groups.

70. The coated substrate of claim 68 wherein the acid-functional compound is an acid-functional polymer.

71. The coated substrate of claim 70 wherein the acid-functional polymer is prepared by the half-ester opening of a cyclic anhydride by reaction with a hydloxy-functional polymer.

72. The coated substrate of claim 71 wherein the hydroxy-functional polymer is the addition polymerization reaction product of:
(i) 5 to 100 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 0 to 95 weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

73. The coated substrate of claim 68 wherein the anhydride-functional polymer, the hydroxy-functional compound, the acid-functional compound and the epoxy-functional compound are each present in the curable composition at a level to provide 0.05 to about 3.0 acid groups and about 0.5 to about 4.0 epoxy groups an about 0.05 to about 6.0 hydroxyl groups for each anhydride group.

74. In a substrate coated with a multi-layer decorative and/or protective coating which comprises:
(i) a basecoat comprising a pigmented film-forming polymer; and (ii) a transparent clearcoat comprising a film-forming polymer applied to the surface of the basecoat composition;
the improvement which comprises utilizing as the clearcoat and/or the basecoat a multi-component curable composition which is reactive upon mixing of the components, wherein the multi-component curable composition comprises:
(i) an anhydride-functional polymer which comprises the polymerization reaction product of:
(a) an anhydride-functional monomer having the structure:

wherein R1, R2, R3 and R4 are each individually hydrogen or methyl; and, optionally, (b) at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer; and (ii) an acid-functional compound having an average of at least two carboxylic acid groups per molecule; and (iii) an epoxy-functional compound.

75. The coated substrate of claim 74 wherein R2, R3 and R4 are each hydrogen.

76. The coated substrate of claim 74 wherein the anhydride-functional polymer comprises the free radical addition polymerization product of a monomer mixture comprising 5 to 100%
by weight of the anhydride-functional monomer and 0 to 95% by weight of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer.

77. The coated substrate of claim 74 wherein the anhydride-functional polymer comprises the free radical additional polymerization reaction product of:
(i) 5 to 75 weight percent of the anhydride-functional monomer; and (ii) 25 to 95 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 70 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

78. The coated substrate of claim 74 wherein the anhydride-functional polymer comprises the free radical additional polymerizable product of:
(i) 15 to 50 weight percent of the anhydride-functional monomer; and (ii) 50 to 85 weight percent of at least one (meth)acrylic monomer; and (iii) 0 to 35 weight percent of at least one other unsaturated monomer copolymerizable with the anhydride-functional monomer and the (meth)acrylic monomer.

79. The coated substrate of claim 74 wherein the acid-functional compound is an acid-functional polymer.

80. The coated substrate of claim 79 wherein the acid-functional polymer is prepared by the half-ester opening of a cyclic anhydride by reaction with a hydroxy-functional polymer.

81. The coated substrate of claim 80 wherein the hydroxy-functional polymer is the addition polymerization reaction product of (i) 5 to 100 weight percent of a hydroxy-functional ethylenically unsaturated monomer; and (ii) 0 to 95 weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the hydroxy-functional monomer.

82. The coated substrate of claim 74 wherein the epoxy-functional compound is a monoepoxide.

83. The coated substrate of claim 74 wherein the epoxy-functional compound is a polyepoxide having an average of at least 2 epoxy groups per molecule.

84. The coated substrate of claim 83 wherein the polyepoxide is a cycloaliphatic polyepoxide.

85. The coated substrate of claim 83 wherein the polyepoxide is a copolymer obtained by the copolymerization of an ethylenically unsaturated epoxy-functional monomer and at least one other copolymerizable ethylenically unsaturated monomer.

86. The coated substrate of claim 74 wherein the anhydride-functional polymer and the acid-functional compound and the epoxy-functional compound are each present in the curable composition at a level to provide 0.3 to about 6.0 acid groups and 0.6 to 12.0 epoxy groups for each anhydride group.

87. The coated substrate of claim 74 wherein the composition also comprises a catalyst for the reaction of acid groups and epoxy groups and a catalyst for the reaction of anhydride groups and hydroxyl groups.

88. A method of using a monomer to impart anhydride functionality to a polymer which process comprises polymerizing:

(i) a monomer having the structure:

wherein R1R2, R3 and R4 are each individually hydrogen or methyl; and, optionally (ii) at least one other monomer copolymerizable therewith.

89. The method of claim 88 wherein R2, R3 and R4 are each hydrogen.

90. A method of using an anhydride-functional polymer as a crosslinker, which method comprises admixing the anhydride-functional polymer with a compound having a average of at least two functional groups per molecule which are reactive with anhydride groups;
wherein the anhydride-functional polymer has an average of at least two anhydride groups per molecule and comprises the free radical addition polymerization reaction product of:

(i) an anhydride-functional monomer having the structure:

wherein R1R2, R3 and R4 are each individually hydrogen or methyl; and, optionally (ii) at least one other unsaturated monomer copolymerizable With the anhydride-functional monomer.

91. The method of claim 90 wherein R2, R3 and R4 are each hydrogen.