Patent ID: 8859697

Claim:
A process for preparing a (meth)acrylate copolymer comprising a tertiary amino group, the process comprising: polymerizing a polymerization mixture by free-radical polymerization in solution at temperatures from 30 to 120° C. over a period of 2 to 24 hours, thereby obtaining a polymerization syrup, degassing the polymerization syrup by distillation or by extrusion, thereby obtaining a degassed polymerization syrup, and comminuting the degassed polymerization syrup, thereby obtaining the (meth)acrylate copolymer in a form of a granulate or powder, wherein: the polymerization mixture of which at least 98% by weight comprises: from 40 to 75% by weight of a monomer mixture, from 0.01 to 5% by weight of at least one polymerization initiator, optionally from 0 to 2% by weight of at least one molecular weight regulator, and from 25 to 50% by weight of a solvent or a solvent mixture, wherein the monomer mixture, the at least one polymerization initiator, and the at least one molecular weight regulator are soluble in the solvent or the solvent mixture; the monomer mixture comprises, based on a total amount of the monomer mixture, from 30 to 70% by weight of a C 1 -C 4 -alkyl ester of acrylic acid or methacrylic acid, from 70 to 30% by weight of an alkyl ester of acrylic acid or methacrylic acid with an alkyl radical and a tertiary amino group in the alkyl radical, and optionally from 0 to 10% by weight of other copolymerizable vinyl monomers; in said polymerizing, at least 99% by weight of monomers in the monomer mixture are converted to the (meth)acrylate copolymer; and the (meth)acrylate copolymer has a weight average molecular weight of from 25,000 to 75,000 g/mol, a polydispersity index of from 2.1 to 2.9, and a residual solvent concentration of less than 1,000 ppm by weight.