METHOD FOR OBTAINING (METH)ACRYLATE COPOLYMER, WHICH CONTAINS QUATERNARY AMMONIUM GROUPS, BY FREE-RADICAL POLYMERISATION IN SOLUTION Russian patent published in 2016 - IPC C08F220/12 C08F220/34 

FIELD: chemistry.

SUBSTANCE: invention relates to method for obtaining (meth)acrylate copolymer, which contains quarternary ammonium groups. Method for copolymer obtaining is realised from mixture of monomers, selected from a) from 80 to 99 wt % of alkyl ether of acrylic acid or methacrylic acid with number of carbon atoms in alkyl groups from one to four, b) from 20 to 1 wt % of alkyl ether of acrylic acid or methacrylic acid with quaternary ammonium group in alkyl radical and c) from 0 to 10% of other copolymerisable vinyl monomers, with addition of one or several polymerisation initiators, in case of necessity one or several molecular weight regulators and one or several solvents to mixture of monomers, with obtaining polymerisable mixture, which is polymerised at temperatures from 30 to 120°C for time period from 2 to 24 hours; for polymerisable mixture eventually consumed are at least 98 wt % of the total quantity of the following components: from 50 to less than 80 wt % of monomers, from 0.01 to 5 wt % of one or several polymerisation initiators, from 0 to 2 wt % of one or several molecular weight regulators, from less than 50 to 20 wt % of solvent or mixture of solvents, in which monomers, included into composition of mixture of monomers, polymerisation initiators and molecular weight regulators, are dissolved, and the remaining up to 2 wt % of polymerisable mixture, being composed by additional additives, such as UV-light absorbers, colorants or colouring substances, with polymerisable mixture being polymerised with formation of polymer syrup with degree of conversion of monomers into copolymer not less than 99 wt %, after that polymer syrup is depleted of gases by distillation or extrusion, and polymer syrup, depleted from gases, is further directed to obtaining copolymer in form of granules or powder, with obtained copolymer being characterised by molecular weight (Mw) from 25000 to 50000, polydispersity index from 2.0 to 3.0 and residual solvent content less than 10000 ppm.

EFFECT: obtaining polymer, satisfying modern pharmaceutical standards, by polymerisation in solution.

8 cl, 11 tbl, 3 ex