Patent ID: 6013739
Filing Date: 2000-01-11
Classification: C08G,C09D

Abstract:
A coating composition comprising a binder consisting of(A) a hydroxyl group containing polyacrylate resin, and(B) at least one crosslinking agent, wherein1.) component (A) consists of the reaction product obtained by polymerizing(a) from 10 to 51% by weight of a mixture comprising(a1) one or more monomers selected from the group consisting of 4-hydroxy-n-butyl acrylate, 4-hydroxy-n-butyl methacrylate, 3-hydroxy-n-butyl acrylate, 3-hydroxy-n-butyl methacrylate, and(a2) one or more monomers selected from the group consisting of 3-hydroxy-n-propyl acrylate, 3-hydroxy-n-propyl methacrylate, 2-hydroxy-n-propyl acrylate, 2-hydroxy-n-propyl methacrylate,(b) from 0 to 20% by weight of one or more monomers selected from the group consisting of hydroxyl group-containing esters of acrylic acid or of methacrylic acid which are different from (a) and have at least 5 carbon atoms in the alcohol residue and hydroxyl group-containing esters of polymerizable ethylenically unsaturated carboxylic acids, which are different from (a),(c) from 28 to 85% by weight of an aliphatic or cycloaliphatic ester of acrylic acid or of methacrylic acid which is different from (a) and (b) and has at least 4 carbon atoms in the alcohol residue, or of a mixture of such monomers,(d) from 0 to 25% by weight of an aromatic vinyl hydrocarbon which is different from (a), (b) and (c), or a mixture of such monomers,(e) from 0 to 5% by weight of an ethylenically unsaturated carboxylic acid, or of a mixture of ethylenically unsaturated carboxylic acids, and(f) from 0 to 20% by weight of an ethylenically unsaturated monomer which is different from (a), (b), (c), (d) and (e), or of a mixture of such monomers,to give a polyacrylate resin having a hydroxyl number of from 60 to 200 mg of KOH/g, an acid number of from 0 to 35 mg of KOH/g and a number average molecular weight of from 1000 to 5000, the sum of the proportions by weight of components (a) to (f) being in each case 100% by weight, and further wherein(2.) component (B) is a mixture comprising(B 1) at least one polymer selected from the group consisting of aliphatic, cycloaliphatic, and araliphatic di- and polyisocyanates having an average functionality of from 3 to 4 and having a uretdione group content of not more than 5%,(B2) optionally, at least one member selected from the group consisting of polymers of aliphatic, cycloaliphatic, and araliphatic di and polyisocyanates having an average functionality of from 2 to 3 and having a uretedione group content of from 20 to 40%, and(B3) optionally, at least one aliphatic, cycloaliphatic, or araliphatic di- or polyisocyanate.