MXPA01005005A - Curable compositions comprising acetoacetoxy and imine functionality - Google Patents

Abstract

A multi-component curable composition which is reactive upon admixing of the components and which comprises:(i) an acrylic polymer having acetoacetoxy functionality;and (ii) an acetoacetoxy functional derivative of a low molecular weight polyol;and (iii) a crosslinking component comprising at least one imine functional compound having an average of at least two imine groups per molecule which are reactive with acetoacetoxy functionality.

Description

CURABLE COMPOSITIONS THAT COMPRISE THE FUNCTIONAL GROUP OF ACETOACETOXI AND IMINA BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a multi-component curable composition which is reactive upon mixing the components and which comprises: (i) an acrylic polymer having an acetoacetoxy functional group; and (ii) an acetoacetoxy functional derivative of a low molecular weight polyol; and (iii) a crosslinking component comprising at least one imine functional compound, having an average of at least two imine groups per molecule, which are reactive with the acetoacetoxy functional group; and (iv) optionally, a polyamine having an average of at least two primary imine groups per molecule. The curable compositions of this invention are especially useful as coatings, particularly primer. The reactive coatings of this invention can be cured at room temperature or dried under pressure at temperatures ranging up to about 350 ° F. The combination of functional materials of acetoacetoxy and functional imine materials provides durable coatings of rapid reaction and excellent adhesion. 2. Description of the Prior Art The use of functional acetoacetoxy materials in Michael-type reactions is known in the art. For example, in the United States patent 3,668,183, the reaction of polyacetoacetates and polyimines is explained. European Patent Application 744,450 explains the reactive compositions of acetoacetates and multifunctional amines. However, the prior art has not explained the combination of an acrylic polymer with acetoacetoxy functional groups and an acetoacetoxy functional derivative of a low molecular weight polyol and a material with imine functional group and, optionally, a polyamine to provide coatings that are cured at low temperature and have excellent durability, adhesion and performance.

A BRIEF SUMMARY OF THE INVENTION This invention relates to a multi-component curable composition which comprises: (a) a first component consisting of: (i) an acrylic polymer having an acetoacetoxy functional group; and (ii) a functional acetoacetoxy derivative of a low molecular weight polyol; and (b) a crosslinking component comprising at least one functional imine compound. In a preferred formula, the curable composition also comprises a functional imine compound having an average of at least two primary amine groups per molecule. In addition, in some applications, it may be preferable to incorporate an organosilane material into the curable composition to obtain improved performance and adhesion properties. In particular, it is preferred to use the curable composition of this invention in combination with about 5 to 80% and, especially, 5 to 50% by weight of an inert solvent, such as esters, ketones, aromatic and aliphatic hydrocarbons, etc. It is convenient to provide the coating composition as a multi-component system that is reactive when mixing the components. In particular, a two-pack system is preferred in which the acetoacetoxy functional materials are combined in one package and the imine compound and, optionally, the amine compound are provided in a second pack.

The two packages can be mixed together to provide the curable coatings immediately before application. Accordingly, an object of this invention is to provide improved curable compositions of excellent reactivity at low temperatures. Another object of this invention is to provide coating compositions which can be used as primer paints, final coat paints or other coating compositions. Another object of this invention is to provide an improved two-pack coating composition, wherein one package comprises acetoacetoxy functional materials and the other package comprises imine functional materials and, optionally, amine functional materials. Another object of this invention is to provide improved coating compositions, which can be cured at room temperature or dried under pressure at elevated temperatures. These and other objects of the invention will be apparent from the following analyzes.

DETAILED DESCRIPTION OF THE INVENTION 1. ACRYLIC POLYMERS THAT HAVE FUNCTIONAL GROUP ACETOACETOXI Acrylic polymers with an acetoacetoxy functional group useful for this invention are those having an average of at least two acetoacetoxy groups per molecule. The polymers can be conveniently prepared by the addition polymerization of one or more unsaturated monomers. A practical process for preparing these polymers involves the polymerization of unsaturated monomers with acetoacetate function, usually together with one or more copolymerizable unsaturated monomers. A monomer with acetoacetate function especially preferred due to its reactivity and commercial availability is acetoacetoxy ethyl methacrylate. Other unsaturated monomers which are useful for introducing acetoacetate functional groups include: acetoacetoxy ethylacrylate, acetoacetoxy propyl methacrylate, allylacetoacetate, acetoacetoxy butyl methacrylate, 2,3-di (acetoacetoxy) propyl methacrylate, etc. In general, it is possible to convert the functional polymerizable monomers of hydroxy into acetoacetates by direct reaction with diketene or other suitable acetoacetyl converting agent. See, for example, Journal of Coatina Technolov, volume 62, page 101 (1990) "Comparison of Methods for the Preparation of the Acetoacetylated Coating Resins" ("Comparison of methods for the preparation of acetoacetylated coating resins"). Alternatively, a hydroxy functional polymer can be prepared by the free radical polymerization of unsaturated monomers with hydroxy function and the resulting hydroxy functional polymer can be converted to acetoacetoxy functional groups by direct reaction with diketene, by transesterification by reaction with suitable alkyl acetoacetates , as tert-butyl acetoacetate or with the thermal reaction of 2, 2, 6-trimethyl-4H-1,3-dioxin-4-one. The acetoacetoxy functional monomer will be present at a level of at least one weight percent of the entire monomer mixture for the acrylic polymer and, in general, will comprise between about 10 and 75% and, preferably, 25 to 50% of all the monomer mixture. Normally monomers with acetoacetoxy function would be copolymerized with one or more ethylenically unsaturated monomers such as: (i) esters of acrylic, methacrylic, cnic, tíglicos acids or other unsaturated acids such as: methyl acrylate, ethyl acrylate, propyl acrylate, acrylate isopropyl, butyl acrylate, isobutyl acrylate, ethylhexyl acrylate, amyl acrylate, 3, 5, 5-trimethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobornyl methacrylate, dimethylaminoethyl methacrylate, tiglato of ethyl, methyl cnate, ethyl cnate, etc .; (ii) vinyl compounds such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl m-chlorobenzoate, vinyl p-methoxybenzoate, vinyl a-chloroacetate, vinyltoluene, vinyl chloride , etc.; (iii) styrene-based materials such as styrene, α-methylstyrene, α-ethylstyrene, β-bromostyrene, 2, 6-dichlorostyrene, etc .; (iv) allyl compounds such as allyl chloride, allyl acetate, allyl benzoate, allyl methacrylate, etc.; (v) other unsaturated copolymerizable monomers such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, acrylonitrile, methacrylonitrile, dimethyl maleate, isopropenyl acetate, isopropenyl isobutyrate, acrylamide, methacrylamide and dienes such as 1,3-butadiene, etc. The polymers are suitably prepared by conventional free radical addition polymerization techniques. Frequently, the polymerization will be initiated by conventional initiators known in the art to generate a free radical such as azobis (isobutyronitrile), cumene hydroperoxide, tert-butyl perbenzoate, tert-butyl peroctoate., ter-amyl peroctoate, di-tert-butyl peroxide, etc. Normally, the monomers are heated in the presence of the initiator and an inert solvent at temperatures ranging from about 35 ° C to 200 ° C and in particular from 75 ° C to 150 ° C, to effect the polymerization. The molecular weight of the polymer can be controlled, if desired, by the selection of the monomers and the initiator, the rate of addition, the temperature and the reaction time and / or the use of chain transfer agents as they are known in the art. The technique. The number average molecular weight of the acrylic functional acetoacetoxy polymer will normally be at least 1,000 as determined by GCP. In general, in applications where a relatively low viscosity is preferred, such as for spraying applications with relatively low levels of volatile organic compounds (VOC), the numerical average molecular weight of the acrylic functional acetoacetoxy polymer will preferably be less than 10,000. and the weighted average molecular weight of preference will be less than 20,000. If the functional acrylic acetoacetoxy polymer must be prepared by the conversion of a hydroxy functional polymer through the methods discussed above, then the monomer with h-idroxy function must be present essentially at the same preferred levels for the acetoacetoxy functional monomer. 2. ACETOACETOXY FUNCTION DERIVATIVE OF POLYOLES In addition to the acetoacetoxy functional acrylic polymer, especially in the practice of this invention, it is preferred to include a functional acetoacetoxy derivative of a low molecular weight polyol, in particular a monomeric polyol. As used herein, the term "acetoacetoxy function derivative of polyols" means compounds having acetoacetoxy function generally obtained by the chemical conversion of at least some of the hydroxyl groups of the polyol to an acetoacetoxy group or a group containing one or more acetoacetoxy groups. These acetoacetoxy function derivatives of low molecular weight polyols help to provide additional crosslinking sites and reduce the overall viscosity of the final curable composition. The polyol raw material must have an average of at least two hydroxy functional groups per molecule and must have a number average molecular weight of less than about 1000 and preferably less than about 500. The preferred polyols are aliphatics, polyols of polyether, polyester and polyurethane, especially diols and triols. Suitable polyols, for example, include diols such as ethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 2, 3 -butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4- bis (2-hydroxyethoxy) cyclohexane, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycol, 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 and polyols such as trimethylolethane, trimethylolpropane, trimethylolhexane, triethylolpropane, 1,2,4-butanetriol, glycerol, pentaerythritol, dipentaerythritol, polycaprolactone polyols, etc. Acetoacetylation to convert the hydroxyl groups of the polyols to the corresponding acetoacetoxy functional derivatives can be conveniently carried out by transesterification with a suitable acetoacetoxy ester, by direct reaction with diketene, or some other method known in the art. The functional acetoacetoxy derivative must have a range of at least about 1.01 acetoacetate groups per molecule and, preferably, at least about 2.0 acetoacetoxy groups per molecule. It is especially preferred that the functional acrylic acetoacetoxy polymer blend and the functional polyol acetoacetoxy derivative be such that at least 1% and preferably from 10% to about 80% of the total acetoacetoxy equivalents are obtained from the derivative of low molecular weight polyol. 3. IMINE COMPOUNDS The imine compounds which are useful in the present invention can generally be represented by the formula: wherein n is from 1 to 30 and, preferably, n is from 1 to 5; Ri and R2 are hydrogen, an alkyl, aryl, cycloaliphatic, or substituted alkyl, aryl, or cycloaliphatic group; and Ri and R2 may be the same or different; and R3 is an aliphatic, aromatic, arylaliphatic or cycloaliphatic group which may also contain heteroatoms such as O, N, S or Si. These imine compounds are generally prepared by the reaction of certain carbonyl compounds such as aldehydes and ketones with amines. Representative carbonyl compounds that can be used to form the imine include ketones such as acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diethyl ketone, benzyl methyl ketone, diisopropyl ketone, cyclopentanone and cyclohexanone and aldehydes such as acetaldehyde, formaldehyde, propionaldehyde, isobutyraldehyde, n-butyraldehyde, heptaldehyde and cyclohexyl aldehydes. Representative amines that can be used to form the imine include ethylenediamine, ethylenetriamine, propylene diamine, tetramethylenediamine, 1,6-hexamethylenediamine, bis (6-aminohexyl) ether, tricyclodecane diamine, N, N'-dimethyldiethyltriamine, cyclohexyl-1, 2, 4 -triamine, cyclohexyl- 1, 2, 4, 5-tetraamine, 3,4,5-triaminopyran, 3,4-diaminofuran and cycloaliphatic diamines as those having the following structures: The imines are conveniently prepared by reacting a stoichiometric excess of the ketone or aldehyde with the polyamine in an azeotropic solvent and removing the water as it is formed. In order to minimize side reactions and avoid delays due to the prolonged process, it is often advisable to avoid the prolonged heating necessary to remove all excess ketone or aldehyde and raw materials without reaction, as long as their presence does not affect the adversely affects the performance of the final product. A preferred type of imine compound for reaction with acetoacetoxy functional materials in the practice of this invention is an adduct obtained by reacting an imine having an additional reactive group other than an imine, such as a hydroxyl group or, preferably, a group amine with a compound, such as an isocyanate, or an epoxide, having one or more chemical groups or sites capable of reacting with the additional reactive group. For example, an imine obtained from the reaction of two moles of an aldehyde or ketone with a triamine having two primary amine groups and a secondary amine group, such as diethylenetriamine, will have an unreacted secondary amine group, which could make subsequently reacting with a monoepoxide and / or polyepoxide, or a monoisocyanate or polyisocyanate to produce the functional amine adduct. A particularly preferred commercial imine having an additional reactive group is Shell Epicure 3501 which is the reaction product of diethylenetriamine and methyl isobutyl ketone. The polyisocyanates useful for reaction with the hydroxyl or amine group of the imine in the preferred configuration have an average of at least two isocyanate groups per molecule. Representative polyisocyanates useful for the preparation of this adduct include aliphatic compounds such as ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, 1,2-propylene, 1,2-butylene, 2,3-butylene, 1,3-butylene, ethylidene. and 1,2-butylidene diisocyanates; cycloalkylene compounds such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and the diisocyanates of 1,3-cyclopentane, 1,3-cyclohexane and 1,2-cyclohexane; the aromatic compounds such as m-phenylene, p-phenylene, 4,4-diphenyl, 1,5-naphthalene and 1,4-naphthalene diisocyanates; aromatic aliphatic compounds such as 4,4-diphenylenediame or diisocyanates, 2,4- or 2,6-toluene or mixtures thereof, 4,4'-toluidine and 1,4-xylylene; substituted nuclear aromatic compounds such as dianisidine diisocyanate, 4,4'-diphenylether diisocyanate and chlorodiphenylene diisocyanate; triisocyanates such as triphenylmethane-4,4 ', 4"-triisocyanate toluene and tetraisocyanates such as 4,4'-diphenyl-dimethylmethane-2, 2', 5, 5'-tetraisocyanate, polyisocyanates polymerized as dimers and trimers and other polyisocyanates containing biuret, urethane and / or allophanate ligatures Preferred polyisocyanates include dimers and trimers of hexamethylene diisocyanate and mixtures thereof For the reaction with imines having amine groups without reaction, useful representative monoperoxides include the monoglycidyl ethers of aliphatic or aromatic alcohols such as butylglycidyl ether, octylglycidyl ether, nonylglycidyl ether, decylglycidyl ether, dodecylglycidyl ether, p-tert-butylphenylglycidyl ether, o-cresylglycidyl ether and 3-glycidoxypropyl trimethoxysilane. monoepoxy as versic acid glycidyl ester (commercially available from CARDURA E of Shell Chemical Company or as Glydexx N-10 from Exxon Chemical Company), or the glycidyl esters of other acids such as non-anoic tertiary acid, tertiary decanoic acid, tertiary undecanoic acid, etc. Similarly, if desired, unsaturated monoepoxy esters such as glycidyl acrylate, glycidyl methacrylate or glycidyl laurate could be used. further, 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. Especially preferred as the polyfunctional epoxy compounds, due to their reactivity and durability, are the cycloaliphatic, bisphenol and novolac epoxies with polyepoxy function. Preferably, the polyepoxies will have a number average molecular weight of less than about 2,000 to minimize the viscosity of the adduct. In particular, for some applications it is preferred to use a combination of both an imine adduct prepared by the reaction of an imine having a secondary amine group and a polyepoxide, and of an imine adduct obtained by the reaction of an imine having a group of secondary amine and a monoepoxide, 4. AMINO FUNCTIONAL COMPOUNDS In the practice of this invention, it is often preferred to include an amine functional compound in combination with the acetoacetoxy functional materials and the imine functional materials. It is known that amine groups react with acetoacetoxy functional groups and the presence of primary amine functional compounds having an average of at least two amine groups per molecule can improve the curable compositions of this invention. The polyamines can be prepared by methods well known in the art such as by the free radical polymerization of acrylic monomers or other unsaturated monomers having a primary amine functional group, or by the reaction of amines having at least two primary amine groups by molecule with a polycarboxylic acid to form polyamide amines. The polyamines can be polymeric and have, in general, a number average molecular weight greater than 800, or materials with lower molecular weight, such as tetraethylenepentamine, 1,3-diaminopropane, 1,6-diaminohexane, etc. The primary polyamines mentioned in Section 3 of this disclosure are also useful in the practice of this invention. Other useful amines include tricyclodecane dimethanoamine and the primary polyamine functional phenols such as Cardolite NC559 from Cardolite, Inc. In general, the amine will be present at a level that provides up to 70% of the total amine and imine equivalents desired for reaction to all of the acetoacetoxy functional group. The ratios of acetoacetoxy groups to other functional groups in the curable compositions can be widely varied within the practice of this invention. It is only necessary to combine the functional materials of acetoacetoxy and other reactive materials in sufficient amounts to provide the desired degree of crosslinking in curing. However, it is usually preferred to use a slight excess of imine and amine equivalents and in general the equivalent ratio of imine and amine, if any, with respect to the total equivalents of acetoacetoxy is at least 1.01 to 1. In the compositions Curable small amounts (eg, normally less than 10% by weight of the total resin solids) of other amine-reactive materials, such as epoxies and in particular polyepoxies, such as cycloaliphatic, bisphenol or novolac polyepoxies can also be used. The curable compositions of this invention can be cured at temperatures ranging from room temperature to about 350 ° F. When the curable compositions are used as coatings, the coatings can be transparent or can contain pigments as is well known in the art. Representative opacifying pigments include white pigments such as titanium dioxide, zinc oxide, antimony oxide, etc., and organic and inorganic chromatic pigments such as iron oxide, carbon black, phthalocyanine blue, etc. The coatings may also contain extension pigments such as calcium carbonate, clay, silica, barytes, talc, etc. 'Coatings may also contain other additives such as flow agents, catalysts, thinners, solvents, ultraviolet light absorbers, flexibilizers (such as thermoplastic acrylic polymers, etc.), adhesion promoters, etc. Preferred adhesion promoters are organosilanes and, in particular, amine silanes or epoxy silanes. The representative organosilanes are explained in Silane Couplina Aerents (Silane Coupling Agents) by E.P. Pluddemann (Plenum Press, New York, 1982). Specific useful silanes include 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane. In general, the organosilane will be present at a level of at least 0.01% by weight of the total resin solids and preferably 0.1 to around 5%. In the curable compositions of this invention it is especially preferred to include a catalyst for the reaction of acetoacetoxy groups and imine and amine groups. Representative catalysts include acids such as benzoic acid and isostearic acid. The catalyst will normally be present at a level of at least 0.01% by weight of the reactants. Since the curable compositions of this invention are generally provided as multi-pack systems, which must be mixed together before use, the pigments, catalysts and other additives can be conveniently added to any or all of the appropriate individual packages. Due to the hydrolysis potential of the reactive groups, for most applications it is particularly preferred that the curable compositions of this invention be non-aqueous systems. The curable compositions of this invention can be applied primarily to any substrate such as metal, plastic, wood, glass, synthetic fibers, etc., by brushing, dipping, roll coating, flow coating, spraying, mold coating or other conventionally employed method. in the coatings industry. The following examples have been selected to illustrate specific convenient modalities and practices for a more complete understanding of the invention. Unless stated otherwise, "parts" means parts by weight and "percent" is the percentage by weight, the equivalent weight is on a basis of weight of solids and the molecular weight was determined by GPC in relation to the standards of polystyrene.

Acrylic Acetoacetoxy Functional Acrylic Resins Acetoacetoxy functional resins can be prepared representatively by a process of (i) feeding a reaction vessel with a suitable solvent and heating to a suitable reaction temperature; (ii) adding a mixture of solvent and initiator and monomers to the heated solvent over a period of three hours; (iii) maintaining the mixture at the reaction temperature; (iv) adding solvent and initiator to the reaction mixture and maintaining the reaction temperature until the polymerization or reaction is sufficiently complete.

Example Al A four-neck reactor equipped with an overhead stirrer, temperature controller, condenser, initiator and monomer feed tubes and nitrogen layer with n-butyl acetate (590.0 parts) was fed, after the solvent was heated at 115 ° C, a homogenous mixture of n-butyl acetate (250.0 parts) and VAZO 67 (172.5 parts) and a mixture of 2- (acetoacetoxy) ethyl methacrylate were supplied gradually to the reactor for 3 hours at 115 ° C. 1000.0 parts), methyl methacrylate (500.0 parts), n-butylacrylate (500.0 parts), styrene (500.0 parts) and 2-mercaptoethanol (47.5 parts). The reaction solution was then kept for 1 hour at 115 ° C. A mixture of n-butyl acetate (10.0 parts) and VAZO 67 (7.5 parts) was supplied to the reactor for 20 minutes and the solution was held for another hour. before it cooled and emptied. The resulting resin had a NVM of 72.9%, a weight per gallon of 8.91, a color of 1, a Gardener-Holdt viscosity of V +, a numerical average molecular weight of 2052 and a weighted average molecular weight of 3540.

Examples A2-All In the same manner as Example Al, representative functional polymers of acetoacetoxy were prepared as shown in the following table: Example Al2 A four-neck reactor equipped with an overhead stirrer, temperature controller, condenser, initiator and monomer feed tubes and nitrogen blanket was fed n-butyl acetate (731.0 parts). After the solvent was heated to 115 ° C, a homogenous initiator mixture of n-butyl acetate (35.0 parts) and tertiary amyl peroctoate (174.0 parts) was gradually fed into the reactor for 3.5 hours at 115 ° C. At the same time, a mixture of 2- (acetoacetoxy) ethyl methacrylate (1048.6 parts), n-butyl methacrylate (256.2 parts), isobornyl methacrylate (505.8 parts) was also gradually supplied to the reactor for 3 hours at 115 ° C. , 2-ethylhexyl acrylate (485.5 parts), styrene (211.8 parts) and 2-mercaptoethanol (55.0 parts). The reaction solution was then held for 2 hours at 115 ° C before it was cooled. Then, the reactor was fed with n-butyl acetate (73.2 parts) as wash solvent.

Polyol Derivatives with Acetoacetoxy Function Example Bl A four-neck reactor equipped with an overhead stirrer, temperature controller, distillation head, condenser, receiver and nitrogen layer was fed with a mixture of tert-butyl acetoacetate (2185.2 parts) and 1,6-hexanediol (814.8 parts). The solution was heated to 115 ° C and the t-BuOH generated from the reaction was distilled off from the solution (reduced pressure can be applied to remove the t-BuOH and keep the temperature below 130 ° C). After the theoretical amount of t-BuOH was collected, the solution was cooled and emptied.

Example B2-BIO In the same manner as Example Bl, representative additional polyol derivatives with acetoacetoxy function were prepared as shown in the following table (in parts by weight): Imine Compounds Example Cl A four-neck reactor equipped with an overhead stirrer, temperature controller, distillation head, condenser and nitrogen blanket was fed with a mixture of tricyclodecanedimethanolamine (300.0 parts) and methyl isobutyl ketone (MIBK) (407.0 parts). The solution was heated to reflux temperature (100-132 ° C) for 5 hours. The water generated from the reaction (53.7 parts) of the water separator was collected. The solution was then cooled and emptied.

Example C2 A four-neck reactor equipped with an overhead stirrer, temperature controller, distillation head, water separator, condenser and nitrogen blanket was fed with a PTHF p-aminobenzoic ester mixture commercially available as Versalink P250 (288.5 parts), isobutyraldehyde (88.4 parts) and toluene (123.1 parts). The solution was heated to reflux temperature (116-150 ° C) for 5 hours. The water generated from the reaction (19 parts) of the water separator was collected. The solution was then cooled and emptied.

Example C3 A four-neck reactor equipped with an overhead stirrer, temperature controller, distillation head, condenser and nitrogen blanket was fed with a mixture of functional secondary amine ketimine prepared by the reaction of diethylenetriamine and methyl isobutyl ketone, available from the market as EPICURE 3501 (900.0 parts), EPON 826 (646.0 parts) and methyl isobutyl ketone (MIBK) (580.0 parts). The mixture was heated to 120-130 ° C and held for 2 hours before it was cooled and emptied.

Example C4 A four-neck reactor equipped with an overhead stirrer, temperature controller, feed inlet, condenser and nitrogen blanket was fed with isophorone diisocyanate (63.9 parts). After the reactor was heated to 50 ° C, a mixture of polycaprolactone polyol Tone 0200 (76.1 parts), dibutyltin dilaurate (0.06 parts) and n-butyl acetate ( 60.0 parts). The solution was heated to 70 ° C and kept for 2 hours before it cooled. This product was described as "Solution I". Another reactor equipped with an overhead stirrer, temperature controller, water separator, condenser and nitrogen layer was fed with bis-hexamethylenetriamine (62.0 parts), isobutyraldehyde (41.6 parts) and toluene (95.6 parts). The solution was heated to reflux temperature (up to 125 ° C) for 3 hours. The water generated from the reaction (10.4 parts) of the water separator was collected. The solution was then cooled to room temperature. "Solution I" was added and mixed with this solution which was then subjected to a chemical reaction with heat development at 60 ° C. The reaction mixture was then heated to 75 ° C and maintained for 1 hour before that cooled and emptied.

Example C5 (Cetimine / Epoxy Adducts) A four-neck reactor equipped with an overhead stirrer, temperature controller, condenser and nitrogen blanket was fed with a mixture of 571.9 parts of the reaction product of diethylenetriamine and methyl isobutyl ketone (obtained by a variation of the process in the commercial product EPICURE 3501 to provide a product containing 10% MIBK, 85% ketimine and about 5% impurities and raw materials without reaction), Epalloy 8240 (an epoxy novolac commercially available from CVC Specialty Chemicals) (256.0 parts), Cardura E-10 (80.0 parts) and methyl isobutyl ketone (MIBK) (93.0 parts). The mixture was heated to 120-125 ° C and kept for 2 hours before it was cooled and emptied.

Examples C6-C11 In the same manner as the previous examples, the following representative imines were prepared: Different curable compositions were prepared as follows and spray applied to cold rolled steel substrates. Unless otherwise stated, the viscosity is measured using a # 2 Zahn cup according to ASTM 4212-93, the time without tack is determined in accordance with ASTM D1640 with a weight of 50 g to 75 ° F and 50% relative humidity , the salt fog test was performed according to ASTM B117 for 500 hours, the wet adhesion test was performed in accordance with ASTM 1735-92 and both wet and dry adhesion were measured according to ASTM 3359-95a.

As demonstrated in Examples DI, D2 and D3, the addition of the silane improves the adhesion and the addition of the functional B2 polyol of AcAc minimizes the VOCs (volatile organic compounds) without adversely affecting viscosity, adhesion or time without tack.

As was demonstrated in Examples D4-D8, the addition of the AcAc functional polyol B2 and the combination of C7 and C8 imines can reduce the viscosity of the coatings while providing acceptable yield. An abrasive paste was prepared by mixing the following materials: A clear coating solution was prepared by mixing the following ingredients: A pigmented coating was prepared as shown below: Additional pigmented coatings were prepared and tested as shown below: In the following examples the combinations of the curable compositions of this invention together with a polyepoxide are demonstrated: Although this invention has been described by a specific amount of embodiments, other variations and modifications may be made without departing from the spirit and scope of the invention set forth in the appended claims. The full disclosure of all applications, patents and publications cited herein are hereby incorporated by reference.

Claims (37)

1. CLAIMS: 1. A multi-component curable composition that is reactive upon mixing the components and comprising: (i) an acrylic polymer having an acetoacetoxy functional group; and (ii) a functional acetoacetoxy derivative of a low molecular weight polyol; and (iii) a crosslinking component comprising at least one imine functional compound having an average of at least two imine groups per molecule, which are reactive with the acetoacetoxy functional group. The curable composition according to claim 1, wherein the curable composition also comprises an amine functional compound having an average of at least two primary amine groups per molecule. 3. The composition according to claim 1, wherein the imine functional compound is an adduct obtained by the reaction of: (i) an imine having at least one hydroxyl group or amine with (ii) one or more compounds having an epoxy or isocyanate functional group that is reactive with the hydroxyl or amine group. 4. The composition according to claim 1, wherein the composition also includes an organosilane. 5. The composition according to claim 4, wherein the organosilane is an organosilane with an epoxy function. 6. The composition according to claim 4, wherein the organosilane is an organosilane with an amine function. The composition according to claim 3, wherein the epoxy functional compound is selected from the group consisting of monoepoxy, epoxy novolak, cycloaliphatic epoxies, Bisphenol A epoxies and mixtures thereof. The composition according to claim 3, wherein the imine crosslinker comprises the reaction products of an imine having at least one primary or secondary amine group with a monoepoxy. The composition according to claim 3, wherein the imine crosslinker comprises the reaction product of an imine having at least one primary or secondary amine group and a polyepoxide having an average of at least two epoxy groups per molecule . The composition according to claim 3, wherein the imine crosslinker comprises the reaction product of an imine having at least one primary or secondary amine group and a monoepoxide and the reaction product of an imine having at least one a primary or secondary amine group and a polyepoxide having an average of at least two epoxy groups per molecule. The reactive composition according to claim 1, wherein the equivalent ratio of the imine functional group to the acetoacetoxy functional group is at least 1.01 to 1.0. The reactive composition according to claim 2, wherein the equivalent ratio of amine and imine functional groups to acetoacetoxy functional groups is at least 1.01 to 1. 13. The curable composition according to claim 1, wherein the acrylic polymer is obtained by polymerizing a monomer mixture comprising from 10 to 75% by weight of an unsaturated functional acetoacetoxy monomer. 14. The curable composition according to claim 13, wherein the acrylic polymer is obtained by the polymerization of a monomer mixture comprising from 25 to 50% by weight of an unsaturated monomer with acetoacetoxy function. The curable composition according to claim 1, wherein the acrylic polymer having an acetoacetoxy functional group is obtained by converting a functional acrylic hydroxy polymer into a functional acetoacetoxy polymer. The curable composition according to claim 1, wherein at least 1% of the total equivalents of the acetoacetoxy functional group are provided by the polyol derivative with acetoacetoxy function. The curable composition according to claim 1, wherein from 10 to 80% of the total equivalents of acetoacetoxy functional group are provided by the polyol derivative with acetoacetoxy function. 18. The curable composition according to claim 1, wherein the low molecular weight polyol is selected from the group of aliphatic polyols, polyester, polyether and polyurethane. 19. The curable composition according to claim 1, wherein the low molecular weight polyol has a number average molecular weight of less than about 1,000. The curable composition according to claim 1, wherein the low molecular weight polyol has a number average molecular weight of less than about 500. The curable composition according to claim 1, wherein the acrylic polymer having a functional group Acetoacetoxy has a number average molecular weight of at least 1,000. 22. The curable composition according to claim 1, wherein the acrylic polymer having an acetoacetoxy functional group has a number average molecular weight of less than 20,000. 23. The curable composition according to claim 1, wherein the acrylic polymer having an acetoacetoxy functional group has a number average molecular weight of less than 10,000. The composition according to claim 3, wherein the imine having at least one amine group is the reaction product of ethylenetriamine and an aldehyde or ketone. 25. The composition according to claim 1, wherein the composition also comprises a polyepoxide. 26. The composition according to claim 2, wherein the composition also comprises a polyepoxide. 27. The composition according to claim 1, wherein the composition is non-aqueous. 28. A multi-component curable composition which is reactive in the mixture of the components and which comprises: (i) an acrylic polymer having an acetoacetoxy functional group and a weight average molecular weight of at least about 1,000; and (ii) a functional acetoacetoxy derivative of a low molecular weight polyol wherein the low molecular weight polyol has a number average molecular weight of less than 1,000; and (iii) at least one functional imine compound having an average of at least two imine groups per molecule, which are reactive with the acetoacetoxy functional group; and (iv) at least one amine functional compound having an average of at least two primary amine groups per molecule. 29. The composition according to claim 28, wherein the low molecular weight polyol has a number average molecular weight of less than 500. The composition according to claim 28, wherein the imine functional compound comprises the reaction product of: (i) an imine having at least two imine groups and at least one reactive group other than an imine; and (ii) a compound having one or more chemical groups capable of reacting with the reactive group. The composition according to claim 28, wherein the imine functional compound comprises the reaction product of an imine having at least one primary or secondary amine group and a monoepoxide and the reaction product of an imine which has at least one primary or secondary amine group and one polyepoxide having an average of at least two epoxy groups per molecule. 32. A multi-component curable composition that is reactive upon mixing the components and comprising: (i) at least one functional acetoacetoxy compound having an average of at least two acetoacetoxy groups per molecule; and (ii) a functional imine compound having an average of at least two imine groups per molecule and comprising the reaction product of an imine having at least one primary and secondary amine group and a polyepoxide; and (iii) a functional imine compound having an average of at least two imine groups per molecule and comprising the reaction product of an imine having at least one primary and secondary amine group and a monoepoxide. The composition according to claim 32, wherein the acetoacetoxy functional compound comprises an acrylic polymer having an acetoacetoxy functional group. 34. The composition according to claim 32, wherein the functional acetoacetoxy compound comprises a functional acetoacetoxy derivative of a low molecular weight polyol. 35. The composition according to claim 32, wherein the composition also comprises an organosilane. 36. The composition according to claim 32, wherein the composition also comprises an amine functional compound having an average of at least two primary amine groups per molecule. 37. The composition according to claim 32, wherein the composition also comprises a polyepoxide.