GB2212166A - Curable resin compositions - Google Patents

Description

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i0 2212166 CURABLE RESIN COMPOSITIONS The present invention relates to novel curable resin compositions.

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Curable resin compositions heretofore widely used for coating or other purposes include those which cumprise a resin containing hydroxyl group_ as func+.ic-i group and a crcsslinking agent able to thermally react with the hydroxyl group, such as melamine resin, blocked isocyanate or the like. However, these compositions have the drawback of producing byproducts when heat-cured such as water, alcohol or the like which would contaminate the interior of a drying furnace and would adversely affect the appearance of cured coat.

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Also known are curable resin compositions comprising a resin containing s, s-unsaturated carbonyl group and a polyamino Compound (U.S. Patent No. 3975251). When heated, this composition is crosslinked and cured by michael addition reaction of the polyamino compound with the,8unsaturated carbonyl group. Yet this composition is likely to entail the disadvantages that the cured coat is susceptible to discoloration and is impaired in the water resistance due to the poiyamino compound remaining in the cured coat. The composition is further defective in diminishing the storage stability because of the micha=__l addition reaction gradually proceeding during storage.

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An object of the present invention is to provide a novel curable resin composition which has overcome the foregoing drawbacks.

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Another objecúof the invention is to provide a ove!Eurab!e resin composion which produces no byproduc during heat-curing w which, when cured, gives coats free of discoloration and outstanding in water resistance.

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A further object of the invention is to provide a novel curable resin composition which is excellent in storage stability.

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These and other objects of the invention will become more apparent from the following description.

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The present invention provides a curable resin composition consisting essentially of:

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(i) a resin (A) containing a,8-unsaturated carbonyl group and primary and/or secondary hydroxyl group, or (ii) a mixture of a resin (B) containing,8-unsaturated carbonyl group and a resin (C) containing primary and/or secondary hydroxyl group, and (iii) at least one curing catalyst selected from the group consisting of alkali m! alkxides, metal hydroxides, organic acid salts of metals, quaternary amonium i0 hydroxides, quaternary phosphonium hydroxides, tertiary sulfonium hydro and or gani= acid salts of these onium hydroxides.

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We conducted extensive research to overcome the foregoing drawbacks of known curable resin compositions and found the following.

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(1) composition c-Trr'=Ising (I) a specific azing catalyst and a resin couhaining =,s-unsaturated carbony! group and primary and/or secondary hydroxyl group, or (i-i) the specific curing catalyst and a mixture of a resin containing the carbonyl group and a resin containing the hydroxyl group is curable on crosslinking at a relatively low temperature and is excellent in storage stability.

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(2) Since the heat-curing is caused mainly by addition reaction of hydroxyl group with unsaturated group, the composition is unlikely to encounter the disadvantages attributabie to the production of by-product or to provide a discolored coat when cured. Further the compositions afford coats outstanding in water resistance, surface smoothness and the like.

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The present invention has been accomplished based on these novel findings.

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This invention provides a curable resin composition consisting essentially of the resin (A) as component (i) and the curing catalyst as the component i0 (iii) and also provides a curable resin composition consisting essentia!ly of the resin mixtnre as he component (ii) and the curing catalyst as the component (iii).

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In the resin (A) as the ccp. onent (i) containing the =,8-unsaturated carbonyl group and primary andor secondary hydroxyl group in the invnticm, the =,S- unsaturated carbonyl group is represented by the formula I -C=C-C-, such as acryloyl, methacryloyl, itaconoyl, maleoyl, fumaroyl, crotonoyl, cinnamoyl, acrylamido, methacrylamido and the like. Of primary and secondary hydroxyl groups, a primary one is preferred in view of curability.

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Insofar as the resin (A) has u,8-unsaturated carbonyl group and primary and/or secondary hydroxyl i group, the resin is not limited to specific type and can be any of known resins including acrylic resins, polyester resins, urethane resins, polybutadiene resins, alkyd resins, epoxy resins, phenol resins, polyether resins and polyamide resins. Further the resin (A) can be prepared by any of known processes.

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The molecular weight of the resin (A) is not specifica!!y limited. Genera!!ythe rin (A) is preferably about 250 to about 100000, more preferably i0 about 500 to about 20000, in peak molecular weight as determined by gel permeation chromatography in view of curability ad solubility in a solvent. From the viewpoints of curability and water resistance of coat, it is suitable that the resin (A) contain about 0.01 to about 20 les, preferably about 0.i to about 5 moles, of he =,8-aturated carbonl group, and about 0.01 to about 5-0 mo!s, preferably about 0.i to about I0 moles, cf the hydroxyl group, per kilogram of the resin.

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Preferred examples of the resin (A) include urethane resins which have the residue of adduct of Nmethylol acrylamide or methacrylamide with isocyanate, the residue being represented by the formula CH2=C-CONH-CH2-OC-NH- (I) wherein R1 is hydrogen'atom or methyl group and which have primary and/or secondary hydroxyl group. These resins serve to give a coat excellent in adhesion because they have an amide linkage and urethane linkage. The resins also provide a coat which remains firmly adhered after immersion in boiling water because of high adhesion of the resin on one hand and the mmde and urethane linkages thereof beim less prone to hydrolysis than an ester! e or the!_ike on the other hand.

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The resin containing the functional group rep_resentd by the formula (I) and the hydroxyl group can beasily prepared, for example, by reacting i mole of N, methy!ol acrylamide or methacrylamide with i mole of a diisocyanate compound in the absence of a catalyst or in the presence of a basic catalyst at a temperature of about 2U to about 150 C for about 1 to about i0 hours; mixing he Iting adduct of isocyanate-containing N-methy!oi acrylmide or methacrylamide (hereinafter referred to as "mdduct (a)") with a hydroxyl-containing resin; and reacting the isocyanate group of the adduct (a) with part of hydroxyl groups in the hydroxyl-containing resin in an inactive organic solvent in the absence of a catalyst or in the presence of a basic catalyst under the same reaction conditions as above.

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Preferred examples of useful diisocyanate compounds are those having two free isocyanate groups per molecule, the two groups being different in reactivity from each other, such as 2,4-tolylene diisocyanate, mxylylene diisocyanate, methylcyclohexane-2,4-diisocyanate, 1,3-diisocyanate methyl cyclohexane, isophorone diisocyanate, etc.

Examples of useful basic catalysts are tertiary mnes such as triethylamine dimethyl ethanol, pyridine, tributy]ne and the like.

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Useful inactive organic solvents are those in which the adduct (a) and the resin (C) can be dissolved or dispersed and which is reeof active hydrogen atom reactive with the isocyanate group of the adduct (a). Exemplary of such solvents are aromatic hydrocarbons such as xylene, toluene and the like; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone nd the like; ethers such as ethylene glycol dimethyl ether, diethy!ene glycol mthyl ether and the like; esters such as methyl cellosolve acetate, ethyl acetate, methyl acetate and the like; etc.

Useful hydroxyl-containing resins are not limited to specific type and can be any of known ones insofar as the resins have at least 2.0 hydroxyl groups on the average per molecule. Examples of such resins are acryl polyol, polyester polyol, polyether polyol, alkyd, caprolactone polyol, epoxy, urethane polyol and like types.

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The,s-unsaturated carbonyl group of the resin (B) in the resin composition of the invention consisting essentially of the resin mixture as the component (ii) and the curing catalyst as the component (iii) is represented by the formula l -C=C-C- III Examples of the group are acryloy!, methacryloyl, i0 nonoy!, maleoyl, fumaroyl, crotonoyl, cinnamoyl, acry1do, methacryl, etc. Of the hydroxyl groups in the resin (C) having primary and/or secondary hydroxyl group, a primary one is preferred in view of curability.

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The kind of the resin (B) is not critical insofar as the resin has m,Bnnaturated carbonyl group. The ind of the resin (C) is not specifically limited if the resin has primary and/or secondary hydroxyl group. The resins (B) and (C) are not limited to specific types and can be any of known ones including acrylic resins, polyester resins, urethane resins, polybutadiene resins, alkyd resins, epoxy resins, phenol resins, polyether resins, polyamide resins and the like. The resins (B) and (C) can be prepared by any of known processes.

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The molecular weights of the resins (B) and (C) are not specifically limited. Generally the resins (B) and {C) have a peak molecular weight of preferably about 250 to about 100000, more preferably about 500 to about 20000, as determined by gel permeation chromatography, in view of curability and solubility in a solvent. From the viewpoints of curability and water resistance of coat, it is suitable that the resin (B) contain about 0.01 to about 20 moles, preferably abQut 0.I to about 5 moles, of the,S-unsaturated ca rbonyl group, per kilogram of the =resin and that the resin (C) contain about 0.01 to about 59 i0 moles, preferably about 0.i to abot!0 moles, of the hydroxyl group, per kilogram of the resin.

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Preferred examples of the resin (B) are urethane resins which have the residue of adduct of N-methylol acrylamide or methacrylamide with isocyanate which is represented by the formula (I). These resins serve to give a coat particularly excellent in adhes/n and resistance to boiling water.

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The resin having the functional group of the formula (I) can be easily prepared, for example, by reacting the adduct (a) with the whole hydroxyl group present in the resin having at least 1.0 hydroxyl group on the average per molecule under the same reaction conditions as those described hereinbefore or reacting Nmethylol acrylamide or methacrylamide with an isocyanatecontaining resin. Examples of useful isocyanatecontaining resins are a homopolymer prepared by homopolymerizing an unsaturated monomer such as isocyanate ethyl acrylate or methacrylate, a,s-dimethyl-m-' isopropenylbenzyl isocyanate, or a reaction product of 1 mole of hydroxyl-containing acrylate or methacrylate with 1 mole of the diisocyanate compound; a copolymer prepared by copolymerizing the same with other radically polymerizable unsaturated monomer; and a resin prepared by reaction of hydroxyl- containing resin with said i0 - l0 diisocyanate compound, etc.

The mixing ratio of the resins (B) and (C) in the resin mixture as the component (ii) according to the i invention is preferably about 99.99 to about 50% by wight, more preferably about 99.9 to about 70% by weight, mf the resin (B) and preferably about 0.01 to about 50% by t, more preferably about 0. I to about 30% by weight, of the resin (C).

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The curing catalyst as the component (iii) in the present invention is at least one species selected from the group consisting of alkali metal alkoxides, metal hydroxides, organic acid salts of metals, quaternary ammonium hydroxides, quaternary phosphonium hydroxides, tertiary sulfonium hydroxides and organic acid salts of these onium hydroxides.

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Representative metals for metal hydroxides are alkali metals, alkaline earth metals, cobalt, nickel, t i copper, molybdenum, lead, iron, chromium, manganese, zinc, etc.

Illustrative alkali metal alkoxides are sodium ethoxide, sodium methoxide, potassium methoxide, potassium ethoxide, etc.

Typical alkali metal hydroxides are sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. Representative alkaline earth metal hydroxides ate calcium ! - i! - l0 hydroxide, gnesi hydro, bari hydroxide, etc.

Useful atezr ammonium hydroxides, aternary phosphoni hydroxides and tertiary sulfonium hydroxides include the hydroxides each represented by the formulas (iI), (Ii!) and (), respectively:

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!- R Go (i!) i- -R @OH (III) l- @OH (IV) In the formulas, Rl, R2, R3 and R4 are the same or different and each represent hydrogen atom or organic group having 1 to 14 carbon atoms, at least one of the RI, R2 and R3 groups is an organic group having 1 to 14 carbon atoms, and the R1 and R2 groups or the RI, R2 and R3 groups when taken together with nitrogen atom, phosphorus atom or sulfur atom to which they e-ached ay form a heteroyc!ic gro.

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The te of organic groups represented by Ri, i0 R2, R3 and R4 and having 1 to 14 carbon atoms is not critical insoZar as the groups substantially do not hinder ionization of ammonium hydroxides, phosphonium hydroxides or sulfonium hydroxides. Generally usable as such organic groups are hydrocarbon groups of 1 to 14 carbon atoms which may contain hereto-atom such as oxygen atom. Examples of organic groups ntaining oxygen atom are hydrocarbon groups substituted with hydroxyl or alkoxy " group.

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Examples of such hydrocarbon groups are aliphatic, alicyclic or aromatic hydrocarbons such as alkyl, cycloalkyl, cyc!oalkylalkyl, aryl and aralkyl groups. The alkyl groups may be any of straight chain or branched chain ones and include those of 8 or less carbon atoms. Preferable alkyl groups are lower ones and include methyl, ethyl, n- or iso-propyl, n-, iso-, secor tertbutyl, pentyl, heptyl and octyl groups. Preferred examples of the cycloalkyl groups or cycloalkylalkyl groups are those having 5 to 8 carbon atoms such as l cyclopentyl, cyclohexyi, cyclohexylmethyl, cyclohexylethyl, etc. Useful aryl groups are phenyl, tolyl, xylyl and the like. Benzyl group is suitable as ara!kyl group.

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Preferred examples of hydrocarbon groups containing hetero-atom such as oxygen atom are --13 - l0 hydroxyalkyl (particularly hydroxy-lower a!kyl), specific examples being hydroxymethyl, hydroxythy!, hydroxybutyl, hydroxypentyl, hydroxyheptyl, hydroxyoctyl, alkoxyalkyl (particularly lower alkoxy-lower a!kyll such as methoxymethy!, ethoxymethyl, ethoxyethy!, n-propoxyethy!, iso- propox_vmethy!, n-butoxymehhyl, iso-butoxyethy!, tertbutoxyethy!, etc.

Given below are exp!es of heterocyc!ic groups fored by the R1 and R2 groups or the R!, R2 and R3 groups when taken together with nitrogen atom, phosphorus atom or" sulfur atom to which they are attached:

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CH3- CH3- CH S CH3 CH3 CH3 - 0 CH3 CH - 0 CH3 - e CH=CHa CH3 CH3 CH-., CH3 CH2 -, CH3 - Curing catalysts useful in the invention include the organic acid salts of hydroxides of these alkali metals, alkaline earth metals and other metals and organic acid salts of said onium hyroxidas.

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Examples of organic acids useful for forming l0 organic acid salts are formic acid, acetic acid, lactic acid, trimethylacetic acid, acrylic acid, methacrylic acid, chloroacetic acid, hydroxyacetic acid, crotonic acid, monomethyl maleate, monoethyl fumarate, monomethy! itaconate, etc. Of these organic acids, those having a dissociation constant (pKa value) of 1 X 10-5 or more, particularly acetic acid, formic acid and acrylic acid are preferred.

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A suitable amount of the curing catalyst useful as the component (iii) is about 0.001 to about 30 parts by weight per i00 parts of the resin (A) as the component (i) or the mixture of resins (B) and (C) as the component (ii). A smaller amount of curing catalyst used results in unsatisfactory curability, hence undesirable. On the other hand, a larger amount of curing catalyst used is undesirable because the catalyst used tends to remain in the cured coat, reducing the water resistance. A preferable amount of curing catalyst is about 0.01 to about 20 parts by weight.

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When required, the curable resin composition of the invention consisting essentially of the resin component as the component (i) or (ii) and the curing catalyst as the component (ii/) may contain additives such as a coloring pigment, extender pigment, corrosionresisting pigment, leveling agent, anti-foaming agent, I0 anti-sagging agent andlthe like.

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he curable esin composition of the invention can be cured on crossllnking by heating at a relatively low temperature. It is suitable that the composition be heated at about 60 to about 300 C, preferably about 100 to about 170PC, for about 5 to about 120 minutes, preferably about i0 to about 30 minutes.

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According to the invention, the resin (A) having a,8-unsaturated carbonyl group and primary and/or secondary hydroxyl group, or alternatively a mixture of the resin (B) having o8-unsaturated carbonyl group and the resin (C) having said hydroxyl group is combined with the specific curing catalyst, thereby affording the advantages that the addition reaction of hydroxyl group with unsaturated group is caused at a relatively low temperature and that the addition reaction produces no byproduct nor entails any color change of cured coat. The compositions of the invention are also advantageous in being excellent in storage stability and forming a coat excellent in water resistance, surface smoothness and the like when cured and are therefore suitable for use as coating compositions, particularly as paints.

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The compositions of the invention prepared using the functional group of the formula (I) as the a,B-unsaturated carbonyl group can produce coats I0 particularly high in adhesion aud resi=-tance to boiling at er.

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The present invention will bedescribed below in greater detail with reference to the following Preparation Examples, Examples and Comparison Examples wherein the parts and the percentages are all by weight.

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]reparation of resin (A) h=vlng =,s--unsaturated carbonyl roup and primary and/or secondary hydroxyl group Preparation Examp!e 1 Glycidyl methacrylate 142 parts 2-Hydroxyethyl acrylate116 parts n-Butyl methacrylate 742 parts Azobis isobutyronitrile25 parts The above mixture was added dropwise to i000 parts of toluene in a 4- necked flask at 120 C over a period of 3 hours. 120 C for 5 hours.

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Methacrylic acid Hydroquinone Tetraethyl ammonium bromide Toluene Thereafter the mixture was aged at 86 parts 0.2 part 1.0 part 87 parts The above mixture was added thereto and the resulting admixture was reacted at 120 C. When an acid value reached! or less, the reaction was terminated, giving an acrylic resin solution. The thus obtained resin l0 solution had a novo!t/!e cDntent of 50.0% and a viscosity of M (as detrmlned at 25 C by a Gardner-Ho!dt bubble viscometer, the same hereinafter). The resin was about 25000 in peak molecular weight as determined by gel permeatien chromatography and had an a,6-unsaturated carbonyl group content of 0.92 mole, a primary hydroxyl group content of 0.92 and a secondary hydrcxy! group content of 0.92 mole, all per kilogram of the resin solid.

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Preparation ExamD.!e 2 "Epikoat #154" (i) 627 parts Acrylic acid 252 parts Hydroquinone 1 part Tributylamine 3 parts Ethylene glycol monobuty ether 883 parts The above mixture was charged into a 4-necked flask and reacted at 100 C. When an acid value reached 0, the reaction was terminated, giving an epoxy resin solution. The thus obtained resin solution had a nonvolatile content of 49.7% and a viscosity of H. The resin was about i000 in peak molecular weight as determined by gel permeation chromatography, and had an,S-unsaturated carbony! group content of 3.98 moles and a secondary hydroxyl group content of 3.98 moles, per kilogram of the resin solid.

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Note: (i) "Epikoat #154": t-ademark, product of Yuka -- 18 - i0 Shell Epoxy Co., Ltd., _nhenol-novo!ak type eq3cxy resin, about 500 in number-average molecular weight, about 174 in epoxy equivalent.

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Preparation Example 3 Ethylene glycol Fumar ic acid rimethylolp=paae 496 parts i044 parts 240 parts The above mixture was charged into a 4-necked flask and subjected to condensation reaction=-= 200 C. When an acid value reached 10 or less, the reaction was terminated. Thereafter 1456 parts of butyl acetate was added thereto, giving an polyester resin solution. The thus obtained resin solution had a nonvolatile content of 50.4% and a viscosity of G. The resin was about 5000 in peak molecular weight as determined by gel permeation chromatography, and had an a,B-unsaturated carbonyl group content of 6.18 moles and a primary hydroxyl group content of 2.34 moles, per kilogram of the resin solid.

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Preparation Example 4 "Placcel #308" (2) i000 parts Isophorone diisocyanate444 parts Methyl ethyl ketone 1444 parts The above mixture was placed into a 4-necked flask, and reacted at 70 C. When an NCO value reached 30, the reaction was terminated.

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l0 2--Hydrxyethyl acrylate ydroone Methyl ethyl ketone 232 parts 1 part 233 parts The above mixture was added thereto and the resultimg admixture was reacted at 80 C. When an NCO value reached! or less, the reaction was terminated, giving a orethane resin solution. The thus obtained resin solution had a nonvolatile cenent of 50.0% and a viscosity of X. The resin was about 2000 in peak molecular weight as determined by gel permeation chromatography and had an s,8-unsaturated carbonyl group content of 1.19 moles and a primary hydroxyl group content of 0.89 mole, per kilogram of the resin solid.

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Note: (2) "Placcel #308": trademark, product of Daicel Chemical Industries, Ltd., -caprolactone type trifunctional polycaprolactone polyol, about 1280 in weight-average molecular weight, 198 in hydroxyl value.

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Preparation Example 5 Isophorone diisocyanate 444 parts 2-Hydroxyethyl acrylate232 parts Methyl ethyl ketone 290 parts The above mixture was charged into a 4-necked flask and reacted at 80 C until n NCO value reached 87, whereupon an isocyanate-containing unsaturated monomer I0 solution was obtained. "Lpikoat #1002" (3) Diethano!amine Methyl ethyl ketone 1256 parts 210 parts 628 parts Aside from the above procedure, the above ture was charged into a 4- necked flask and reacted at 80 C ver a period of 3 hours, giving a hydroxylconta/ning resin solution.

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The monomer solution (966 parts) and 2094 parts of the hydroxylcontaining resin solution were mixed and reacted at 80 C for 10 hours, giving an epoxy urethane resin solution. The obtained resin solution had a nonvolatile content of 70.0% and a viscosity of X. The resin was about 2300 in peak molecular weight as determined by gel permeation chromatography, and had an a,s-unsaturated carbonyl group content of 0.93 mole and a primary hydroxyl group content of 0.93 mole, per kilogram of the resin solid.

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Note: (3) "Epikoat #1002": trademark, product of Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin, about 1256 in number-average molecular weight, about 630 in epoxy equivalent Examples 1 to 17 The c,_rabie res-'cEp_sitions of the present invention were prepared by homogeneously mixing the resin solutions obtained in Preparation Examples and the curing catalysts as shown below in Table 1 in the amounts listed therein.

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Table 1 .DTD:

Component Resin (as solids, part) Preparation Example 1 Praparahion Example 2 Praparation Example 3 Praparation Example 4 Curing catalyst (active component, part) Potassium hydroxide Potassium formate SodJ, Um ethylate Ca],cium hydroxide Calcium acetate i00 i00 Example 4 5 m I00 i00 i00 i00 i00 L Component Resin ([rJ t:(11ids, part) Prepa1:nt.un Example 2 Prepal:atlon Example 3 Preparatlon Example 4 Prepn,:al:J.on Example 5 Curing catalyst (active. component, part) Tet ramP. hyiammonium hydroxide Tet ramethylammonium acetate Ethyldime thylsul fonium hydroxide Ethyldimethylsulfonium acetate Compound A (4) Acetate of Compound A Compound B ('5) Acetate of Compound B Cobalt acetate Table 1 (continued) 9 10 ii 12 i00 i00 - - - - i00 i00 0.i 0.2 - 0.05 0.07 Example 13 i00, 0.01 N i00 m O.02 i00 i0 i 0() L..

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t,..

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I I,,3 L I Note: ('4} Coond A is a ccmp_ represented by (5) Compound B is a compound represented by Each of the compositions prepared in Examples 1 to 17 was applied to a glass plate to form a layer having a thickness of about 20 #m when dried. The layer deposited on the glass plate was cured by baking#in an oven. The coated glass plate was checked for the water resistance and gel fraction ratio. The compositions were also tested for the storage stability. The baking was performed under the following conditions and the tests were conducted by the methods described below. Baking conditions The coated glass plate was baked at!40 C for 30 minutes in Examples i to 5 and 17, and-t!00 C for I0 iinutes_. cie __ 6,-!20=C for l0.mi._utes in - _x-_.i-, = 7 and 8 a_d =-!40 C for!0 minutes =zx---D=_ ies m to!5.

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Water resistance i0 The appearance of the coated glass plate was Ehcke, d after 7 days of immersion in warm water at 40 C. Gel fraction ratio The layer formed and cured on the glass plate was peeled and placed into a container of 300-mesh stainless steel netting whereupon the layer wms extracted with a SYhlet's extractoT for 6 hours using, a solvent xture of acetone and methanoi in e uua! amounts in terms of weight. The gel fraction ratio was calculated according to the following equation:

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Gel fraction ratio (%)= (weight of layer after extraction/weight of layer before extraction) X i00 Storage stability Into a hermetically closed can 250 cc in internal volume was charged 200 g of each of the compositions obtained in Examples and Comparison Examples. The composition was checked for properties after 30 days of storage at 50 C. The composition involving neither significant increase of viscosity nor gelation was expressed with a mark "A". Resistance to discoloration The layer formed and cured on the glass pl-ate was visually inspected for the degree of color change. The layer which had no color change was expressed as A, and the layer which turned yellow as B. Table 2 below shows the test results.

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Table 2 .DTD:

Properties Water resistance Gel fraction ratio Storage stability Resistance to discoloration 1 2 3 NC NC NC NC 98.2 96.6 90.4 95.8 A A A A A A A A Example 4 5 .DTD:

6 7 8 NC NC NC NC 95.6 98.8 96.2 96.0 A A A A A A A A Table 2 (continued) ... Properties Water resistance Gel fraction ratio Storage stability Resistance to discoloration 9 i0 ii NC NC NC NC 95.8 95.6 90.9 90.7 A A A A A A A A Example 12 13 .DTD:

14 15 16 17 NC NC NC NC NC 95.0 94.8 93.8 93.5 90.3 A A A A A A A A A A ! -4 I ( NC=No change) i0 Resistance to boilin water ach af the compositions was checked for the resistance to boiling water by the following method.

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The composition was applied to a steel plate treated with zinc phosphate to form a layer having a 20 m thickness when dried. The coated p!ate was baked and then mersed in huiling wher for 1 hour or 2 hours and withdrawn to evaluate the appearance of layer and the adhesion.

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(i) Appearance of coating layer The coating layer was checked for cracking, peeling and blistering. (ii) Adhesion A coated plate was cut crosswise to the substrate to produce i00 squares having l-mm side, and cellophane adhesive tape was adhered and peeled off after uniformly pressing the tape-covered surface with an even force. Then the number of squares remaining adhered was counted.

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Table 3 below shows the results.

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Table 3 .DTD: Resistance to boiling water 1 hour of immersion Adhesion Appearance 2

hours oE immersion Adhesion Appearance Baking conditions Temperature ( C) Time (min) 1 2 3 Example 4 5 .DTD:

I00 i00 I00 i00 I00 i00 i00 i00 i00 Good Good Good Good Good Good Good Good Good 60 60 60 60 80 80 60 SB SB SB SB SB SB Good Good SB 170 170 170 170 170 170 170 30 30 30 30 30 30 30 (St{=Sllght blistering) Table 3 (continued) Resistance to boiling water 1 hour of immersion Adhesion Appearance 2 hours of immersion Adhesion Appearance Baking conditions Temperature ( C) Tme (min) i0 ii 12 i00 i00 i00 Good Good Good 80 SB Good Good 170 30 30 30 Example 13 14 i00 i00 i00 I00 i00 Good Good Good Good Good 80 80 Good Good Good Good 2O Blistering 170 170 160 30 30 30 (SB=Silght blistering) -3i- i0 Preparation of resin (B) having,8-unsaturated carbonyl roup Preparation Example 6 Glycidyl methacrylate 142 parts n-Butyl methacrylate 858 parts Azobisisobutyronitrile 25 parts The above mixture w-=s added dropwise to i000 parts of toluene in a 4- Decked flask at!20 C over a 3 hours' period. The resu!ting mixture was aged t 120 C for 5 hours. Methacrylic acid Hydroquinone Tetraethyl ammonium bromide Toluene 86 parts 0.2 part i.0 part 87 parts The above mixture was added thereto and the resulting admixture was reacted at 120 C. When an acid value reached 1 or less, the reaction was terminated, giving an acrylic resin solution. The resin solution had a nonvolatile content of 50.0% and a viscosity of H. The resin was about 25000 in peak molecular weight as determined by gel permeation chromatography and had an u,8-unsaturated carbonyl group content of 0.92 mole and a secondary hydroxyl _urup content of 0.92 mole, per kilogram of the resin solid.

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Preparation Ex-=mple 7 l0 "Epik oat #154" Arylic acid Hydroquinone Tr ibutylamine Ethylene glycol monobutyl ether 627 parts 252 parts 1 part 3 parts 883 parts The above mixture was introduced into a 4-necked flask and reacted at 100"C. When an acid value reached 0, the reaction was terminated, giving an epoxy resin solution. The resin solution had a nonvolatile content of 49.7% and a viscosity of H. The resin was about 1000 in peak molecular weight as determined by gel permeation chromatography and had an a,B- unsaturated carbonyl group content of 3.96 moles and a secondary hydroxyl group content of 3.96 moles, per kilogram of the resin solid.

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Ethylene glycol Fumaric acid Preparation Example 8 496 parts t 1044 parts The above mixture was placed into a 4-necked flask and subjected to condensation reaction at 200 C. On completion of dehydration, the reaction was terminated. Thereafter 1252 parts of butyl acetate was added to the reaction mixture, giving a polyester resin solution. The resin solution had a nonvolatile content of 50..2% and a viscosity of Q. The resin was about 3500 in peak molecular weight as determined by gel permeaon l0 ch[omatography and had an a,8-unsaturated carbany! group content of 7.19 rubles per kilogram of the resin solid but no hydroxyl group.

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Preparation Example 9 "21acce! #308" Isophorone diisocyanate Methyl ethyl ketmne I000 parts 666 parts 1666 parts when an NCO value reached 38. 2-Hydroxyethyl acrylate Hydroquinone Methyl ethyl ketone 348 parts 1.5 parts 350 parts The above mixture was added thereto and the resulting admixture was reacted at 80 C. When an NCO value reached 1 or less, the reaction was terminated, giving a urethane resin solution. The resin solution had a nonvolatile content of 49.8% and a viscosity of Z. The resin was about 2000 in peak molecular weight as determined by gel permeation chromatography and had an s,S-unsaturated carbony! group content of 1.49 moles per kilogram of the resin solid but no hydroxyl group. Preparation of resin (C)having primary and/or secondary hydroxyl group Preparation Example I0 The above mixture was placed into a 4-necked flask and reacted at 70 C. The reaction was terminated i0 2-Hydroxyethy! acrylate n-Butyl methacrylate Azobisisobutyr onitrile 116 parts 884 parts parts The above mixture was added dropwise to 1000 parts of toluene in a 4- necked flask at 120 C over a 3 hours' period. The mixture was aged at 120 C for 5 hours, giving n acrylic resin solution. The resin solution had a nonvolatile content of 50.0% and a viscosity of O. The resin was about 30000 in peak molecular weight as determined by gel permeation chromatography and had a primary hydroxyl group content of 1.00 mole per kilogram of the resin solid but no a,s-unsaturated carbonyl group.

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Preparation Example ii "Epikoat #154" 627 parts Diethanolamine 245 parts Ethylene glycol monobutyl ether 872 parts The above mixture was introduced into a 4-necked flask and reacted at 100 C for 1 hour, giving an epoxy resin solution.

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The resin solution had a nonvolatile content of 49.7% and a viscosity of V. The resin was about 1000 in peak molecular weight as determined by gel permeation chromatography. The resin had a primary hydroxyl group conhent of 5.45 moles and a secondary hydro! group content of 2.73 moles, per kilogram of e resin solid but i0 no =,8-unsaturated carbonyl group.

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Preparation Ex-ample 12 Ethylene glycol 496 parts Phthalic acid 1332 parts Trimethylolpropane 240 parts The above mixture was charged into a 4-necked flask and subjected tm condensation reection at 200 C. When an acid value reached!0 or less, the reaction was terminated. Thereto added was!906 parts of butyl acetate, giving a polyester resin solution. The resin solution had a nonvolatile content of 50.5% and a viscosity of M. The resin was about 5000 in peak molecular weight as determined by gel permeation chromatography. The resin contained no u,8-unsaturated carbonyl group but had a primary hydroxyl group content of 1.78 moles per kilogram of the resin solid.

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Examples 18 to 30 and Comparison Examples 1 to 3 The curable resin compositions of the present invention and comparative curable resin compositions were prepared by homogeneously mixing the resin solutions obtained in Preparation Examples and the curing catalysts shown below in Table 4 in the amounts listed therein.

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Table 4 .DTD:

Compon e n t Resin LB[ Preparal:.[on Example No.

Soli(s eont:ent of resin (part) Resin IC[ Prapnl:ah].on Example No.

Solids cont:ent of resin (part) Curing catalyst (active component, part) Potassium hydroxide Potassium formate Sodium ethylate Calcium hydroxide Calcium reehate Tetramethy3ammonium hydroxide Teúra,lehhy]ammonium acetate Ethyld [mf.] I: hylsu Ifonium hydroxide Example .DTD:

21 22 6 6 9 9 9 7 7 8 95 95 95 80 80 30 i0 I0 ii Ii ii Ii 5 5 5 0 2 - 5 0.1 ii m I I Table 4 (continued) Component Resin (B Preparation Example No.

Solids content of resin (part) Resin (Cl Preparation Example No.

Solids content of resin (part) "Placcel @308" (part) Hexameth[lenedlamine (part) Curing catalyst (active component, part) Potass]t]m hydroxide Ethyldimethylsulfonium acetate Compound A (4) Acetate of Compound A Compound B (5) Acetate of Compound B Example .DTD:

27 28 29 8 9 9 6 90 50 _ Comparison Example 30 1 2 3 6 9 6 9 i00 50 80 12 - - I0]0 - i0 - - 50 50 - 50 - 10 i0....

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0.02 m i0 m 0.01 Q I t -4 I I0 of the compositions prepared in Examples 18 to 30 nd Ccmparison Examples 1 to 3 was applied tom glass plate to form a layer having a thickness of about 20 m when dried. The layer deposited on the glass plate was cured by baking in an oven. The cured coated plate was checked for the water resistance and gel fraction ratio. The copositions were also tested for the storage stability. The coated glass plates were baked at 140 C for 30 minutes in Examples 18, 19 and 27 to 30 and Comparison Examples! to 3, at 140 C for I0 minutes in Examples 20 to 22, at 120 C for 30 minutes in Examples 23 and 24 and at 100 C for I0 minutes in Examples 25 and 26. Table 5 below shows the results.

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Each of the compositions was checked for the resistance to boiling water by the same method as the foregoing one.

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Table 6 below shows the results.

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Table 5 .DTD:

Properties 18 19 20 Water resistance NC NC NC Gel f[action ratio94.8 94.5 92.8 Storage stabilityA A A ResiStance to discoloration A A A Example .DTD:

21 22 23 24 25 NC NC NC NC NC 92.9 92.6 95.5 95,4 94.6 A A A A A A A A A A Table 5 (continued) ProPerties Water resistance Gel fraction ratio Storage stability Example .DTD:

27 28 29 NC NC NC NC NC 94.4 90.9 90.9 91.5 91.3 A A A,A A Resistance to discoloration A A A A A Comparlson Example 1 2 3 Blush- Dis- Blister- ]ng solved ing 75.2 0 98.7 A A Gelled In 2 days A A B I ( NC=No change) Table 6 .DTD:

Resistance to boiling water 1 hour of immersion Adhesion Appearance 2 hours of immersion Adhesion Appearance Baking conditions Temperature ( C) Time (min) Example .DTD:

18 19 20 21 22 23 24 26 i00 i00 i00, I00 I00 i00 I00 i00 100 Good Good Good Good Good Good Good Good Good 60 80 80 60 60 80 80 SB SB SB Good Good SB SB Good Good 170 170 170 170 170].70 170 30 30 30 30 30 30 30 I o I (SB=Slight blistering) Table 6 (continued) Resistance to boiling water 1 hour of immersion Adhesion Appearance 2 hours of immersion Adhesion Appearance Baking conditions Ten,perature ( C) Time (min) Example 28 29 i00 i00 i00 i00 Good Good Good Good 8O 80 8O 8O Good Good Good Good 170 170 30 30 Compar i son Example 1 2 3 Peeling Dissol- Peeling of tlon of of coat coat coat u m m m 170].70 170 30 ! I I0 Examples illustrative of curable resin compositions containing u,8- unsaturahed carbnyl group, as the functional group of the formula (l) Example 31 "Epikoat #1002" 1256 parts Diethano!amine 210 parts Methyl ethyl ketone 628 parts The above mixture was charged into a 4-necked flask and reacted at 80 C for 3 hours, giving a hydroxyl- containing resin solution. Isophorone diisocyanate N-methy!ol acrylamide Methyl ethyl ketone 444 parts 202 parts 277 parts Aside from the above procedure, the above mixture was placed into a 4necked flask and reacted at 80 C until an NCO value of 91 was reached, whereupon an isocyanate-containing unsaturated monomer solution was obtained.

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The hydroxyl-containing resin solution (2094 parts) was mixed with 923 parts of the isocyanatecontaining unsaturated monomer. The mixture was subjected to reaction at 80 C for 10 hours, giving an epoxy urethane resin solution. The rsin solution had a solids content of 70% and a viscosity of Z5. The resin was about 2200 in peak molecular weight as determined by gel permeation l0 chromatora!Dhy and had an s,B-unsaturated carbony! group content of 0.95 mole and a primary hydroxyl group content of 0.95 mole, per kilogram of the resin solid. One part of cobalt acetate was added to 100 parts of the resin solution (as solids), followed by mixing them, whereupon the curable resin composition of the invention was obtained.

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mp!e 32 The curable resin composition of the present invention was produced by carrying out the same procedure as done in Example 31 with the exception of using the same amount of calcium acetate in place of cobalt acetate.

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Example 33 .DTD:

The curable resin composition of the present invention was produced by carrying out the same procedure as done in Example 31 with the exception of using 0.5"part of trimethylsulfonium acetate in place of cobalt acetate.

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Example 34 .DTD:

The curable resin composition of the present invention was produced by carrying out the same procedure as done in Example 31 with the exception of using 0.2 part of sodium formate in place of cobalt acetate.

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Examp!e 35,=--Dimethy!--m-isnyl benzyl isocyanate 210 parts -- 44- l0 n-Butyl acrylate Styrene Azobis i s obuty r onitr ile 649 parts 150 partm parts One thousand parts of toluene was charged into a 4-necked flask and heated with stirring to 120 C and the above mixture was added dropwise over a 3 hours' leriod. The resulting arure was aged at the same tempe_ratur for 2 hours, giving an isocyanate-containing acrylic resin solution having a solids content of 50% and a viscosity of P.

N-methylol acrylamide 101 parts Methyl ethyl ketone i01 parts Hydroquinone 0.i part The above mixture was added dropwise to 1029 parts of the resin solution and the resulting admixture was reacted for 5 hours until an NCO value of 1 or less was achieved, whereby an acryl urethane resin solution was obtained. The resin solution had a solids content of 50% and a viscosity of Z. The resin was about 26000 in peak molecular weight as determined by gel permeation chromatography and had an a,s-unsaturated carbony! group content of 0.90 mole per kilogram of the resin solid.

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2-Hydroxyethyl acrylate n--Buty!methacry!ate Azobisisobutyronitrile 232 parts 768 parts parts i0 Aside from the above procedune,!000 parts of toluen was placed into a 4- necked flask and heated with stirring to 120 C. The above mixture was added dropwise over a 3 hours' period, and the resulting admixture was ged at the same temperature for 2 hours, giving an acrylic resin solution. The resin solution had a solids cntent of 50% and a viscosity of E. The rin was about 2400 in pek molecular weight as determined by gel permeation chromatography and had a primary hydroxyl group content of 2. 00 moles per kilogram of the resin solid.

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Tetramethylammonium hydroxide (0.5 part) was mixed with 100 parts of a mixture of 50 parts of the acryl urethane resin solution (as solids) and 50 parts of the acrylic resin solution (as solids), whereby the curable resin composition of the invention was obtained.

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Example 36 .DTD:

The curable resin composition of the invention was prepared in the same manner as done in Example 35 with the exception of using a different amount, i.e. 1.0 part, of tetramethylammonium hydroxide.

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Example 37 .DTD:

The curable resin composition of the invention was prepared in the same manner as done in Example 35 with the exception of using 1.0 part of cobalt acetate in place of tetramethylaonium hydroxide.

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i0 Example 38 .DTD:

The curable Tesin composi%ion of the invent_ion was prepared in the mm manner as done in Example 35 with the exception of using 0.5 part of sodium formate in place of tetramethylmmonium hydroxide.

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Each of the compositions obtained in Examples 31 to 38 was applied ko a glass plate to form a layer hving a thickness of about 20 m when dried. The layer deposited on the glass plate was cured by baking in a dryer. The coated plate was checked for the water resistance and the gel fraction ratio. Also the compositions were tested for the storage stability. The baking was conducted by the same method as described hereinbefore, at 140 C for 30 minutes in Examples 31 to 33, 35 and 37 and at 130 C for 30 minutes in Examples 34, 36 and 38. Table 7 below shows the results.

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Each of the compositions was checked for the resistance to boiling water by the same method as the foregoing one with the results shown below in Table 8.

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Table 7 .DTD:

Properties 31 32 33 Water resistance NC NC NC Gel fraction ratio 95.5 92.8 94.2 Storage stability A A A Resistance to discoloration A A A Example 34 35 .DTD:

NC NC NC NC NC 98.8 94.0 94.5 93.3 97.9 A A A A A A A A A A l ( NC=No change) Table 8 .DTD:

Resistance toboiling water 1 hour of immersion Adhesion Appearance 2 hours of immersion Adhesion Appearance Bakinq conditions Temperature ("C) Time (min) Example .DTD:

32 33 34 35 36 37 38 i00 i00 i00 i00 I00 I00 i00 I00 Good Good Good Good Good Good Good Good i00 i00 i00 i00 100].00 I00 i00 Good Good Good Good Good Good Good Good 160 130 160 130 160 130 30 30 30 30 30 30 i0 .CLME:

Claims (7)

1. CLAIMS:

   .CLME:

   i. A curable esin composition cnnisting essentially of:

   .CLME:

   (i) a resin (A) containing,,B-unsaturated carbonyl group and primary and/or secondary hydroxyl group, or (ii) a mixture of a resin {B) containing =,s-unsaturated carbonyl groupnd a resin (C) contain/mg primary and/or secondary hydroxyl group, and (iii) at least one curing catalyst selected from the group consisting of alkali metal alkoxides, metal hydroxides, organic acid salts of metals, quaternary ammonium hydroxides, quaternary phosphonium hydroxides, tertiary sulfonium hydroxides and organic acid salts of these onium hydroxides.

   .CLME:
2. 2. A composition according to claim 1 wherein the resin (A) is a resin which has the residue of adduct of N-methylol acrylamide or methacrylamide with isocyanate, the residue being represented by the formula 0 II CH2=C-CONH-CH2-OC-NH- (I) wherein R1 is hydrogen atom or methyl group and which has hydroxyl group.

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3. 3. A composition according to claim i wherein the resin (B) is a resin which ha the residue of adduct of N-methylo! acrylamide or mthacrylamide with i0 isocyanate, the residue being represented by the formula H CH2=C-CONH-CH2-OC-NH- (I) wherein R! is hydrogen atom or methyl group.

   .CLME:
4. 4. A composition according to claim 1 wherein the resin (A) is a resin having about 0.0! to about 20 moles of the,s-unsaturated carbonyl group and about 0.0! to about 50 moles of the hydroxyl group, per kilogram of the resin.

   .CLME:
5. 5. A composition according to claim 1 wherein the resin (B) has about 0. 0! to about 20 moles of the s,Sunsaturated carbonyl group, per kilogram of the resin, and the resin (C)has about 0.01 to about 50 moles of the hydroxyl group, per kilogram of the resin.

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6. 6. A composition according to claim 1 wherein the resin mixture as the component (ii) consists of about 99.99 to about 50% by weight of the resin (B) and about 0.01 to about 50% by weight of the resin (C).

   .CLME:
7. 7. A composition according to claim 1 wherein the amount of the curing catalyst as the component (iii) is about 0.001 to about 30 parts by weight per 100 parts by weight of the resin (A) as the component (i) or the mixture of the resin (B) and the resin (C) as the component (i i).

   .CLME:

   Published 1989 at The Patent Office, State House.66ql Hzgh Ho]born. London WCI]% 4TP.Furer copies may be obtazned from The Patent Office. Sales Branch, St Mary Cray, 0rpLngton, Kent BR,5 3RD. Printed by Multiplex techniques ltd, St Mary Oray, Kent, Con. 1/87