Copolymer solutions based on addition products of .alpha., .beta.-unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha., .beta.-unsaturated monomers

A process for preparing a hydroxyl-containing copolymer solution containing inert organic solvents and copolymers based on addition products of .alpha., .beta.-unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha., .beta.-unsaturated monomers with or without hydroxyl groups, wherein said copolymer solution comprises the components:

• A) 15 to 50% by weight of inert organic solvents,
• B) 50 to 85% by weight of hydroxyl-containing copolymers, wherein said hydroxyl-containing copolymers are obtained by means of simultaneous addition, condensation and polymerization in inert organic solvents or mixtures thereof which exhibit a boiling range between 160.degree. C. and 200.degree. C., and by heating under reflux in the presence of polymerization initiators, optionally chain transfer agents, optionally carboxy-epoxy catalysts, of
• a) 10 to 30% by weight of glycidyl esters of .alpha.-alkylalkanemonocarboxylic acids and/or .alpha.,.alpha.-dialkylalkanemonocarboxylic acids,
• b) 5 to 12% by Weight of methacrylic acid,
• c) 10 to 27% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxyalkyl radical,
• d) 10 to 38% by weight of styrene,
• e) 1 to 5% by weight of polypropylene glycol monomethacrylate having an average molecular weight of 350 to 387,
• f) 3 to 20% by weight of alkyl methacrylate having 1 to 8 carbon atoms in the alkyl radical,
• g) 9 to 20% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight,
• said method comprising heating said inert solvent and said glycidyl ester of .alpha.-alkylalkane monocarboxylic acids and/or .alpha.,.alpha.-dialkylalkane monocarboxylic acids as initial charge into which the necessary monomers a, b, c, d, e, f and component g, polymerization initiators, optionally chain transfer agents, optionally carboxy-epoxy catalysts are subsequently gradually introduced over a period of 12 to 20 hours;
• and subsequently maintaining the temperature from 140.degree. to 195.degree. C. for 2 to 5 hours, with or without the addition of further polymerization initiator, to thereby form said copolymer solution.