PROCESS FOR APPLYING A DOUBLE-LAYERED COVERING LACQUER ON THE SURFACE OF A SUBSTRATE

摘要

A process is disclosed for producing a double-layered covering lacquer by using a transparent covering lacquer containing a hydroxyl group-containing polyacrylate resin produced by polymerizing (a) 10 to 51 % by weight 4-hydroxy-n-butylacrylate or 4-hydroxy-n-butylmethacrylate or a mixture of 4-hydroxy-n-butylacrylate and 4-hydroxy-n-butylmethacrylate; (b) 0 to 36 % by weight of a hydroxyl group-containing ester of acrylic acid different from (a) or a hydroxyl group-containing ester of methacrylic acid or a mixture of such monomers; (c) 28 to 85 % by weight of an aliphatic or cycloaliphatic ester of methacrylic acid different from (a) and (b) with at least 4 C atoms in the alcohol residue or a mixture of such monomers; (d) 0 to 3 % by weight of an ethylenically unsaturated carboxylic acid or a mixture of ethylenically unsaturated carboxylic acids and (e) 0 to 20 % by weight of an ethylenically unsaturated monomer different from (a), (b), (c) and (d) or a mixture of such monomers, into a polyacrylate resin with a hydroxyl number from 60 to 200, an acid number from 0 to 35 and a number average molecular weight from 1,500 to 10,000. The sum of the parts by weight of components (a), (b), (c), (d) and (e) is always 100 % by weight and the composition of the component (c) is selected so that when said component (c) is polymerized alone, a polymethacrylate resin having a glass transition temperature from +10 to +10 DEG C is obtained.