Acrylate polymers based on polyester resins or polyester oligomers

Abstract

Acrylate copolymers AB obtainable by polymerization of a monomer mixture A in an organic solvent or in bulk, the monomer mixture A comprising proportions by mass of from 25 to 80% of C.sub.1 -C.sub.20 -alkyl (meth)acrylates whose alkyl radicals can be linear, branched or cyclic, from 1 to 28% of C.sub.2 -C.sub.20 -hydroxyalkyl (meth)acrylates whose hydroxyalkyl radicals can be linear, branched or cyclic, from 0.5 to 20% of .alpha.,.beta.-unsaturated carboxylic acids and from 0 to 55% of aromatic vinyl compounds or aliphatic vinyl esters and vinyl ethers, vinyl halides, olefinically unsaturated ketones or aldehydes, esters of glycidyl alcohol or methylglycidyl alcohol with olefinically unsaturated carboxylic acids, or nitriles of .alpha.,.beta.-unsaturated carboxylic acids, in the presence of free-radical polymerization initiators and of at least one polyester or polyester oligomer B obtaintable by polycondensation of polyoles and polycarboxylic acids and having a hydroxyl number of from 50 to 350 mg/g, an acid number of from 1 to 50 mg/g and a weight-average molar mass M.sub.w of up to 5000 g/mol, with the provisos that the polyester or the polyester oligomers are free from olefinic double bonds, that the proportion by mass of component B in the end product AB is less than 10% of its mass and that this end product has an acid number of from 5 to 45 mg/g, a hydroxyl number of from 40 to 125 mg/g and a weight-average molar mass M.sub.w of not more than 10,000 g/mol and a polydispersity (=M.sub.w /M.sub.n) of 3 or less than 3. The copolymers can be employed in coating compositions for metals, plastics, wood, leather, textiles, paper and building materials.