GRAFT COPOLYMER PREPARATION PROCESS Russian patent published in 2003 - IPC

FIELD: polymer production. SUBSTANCE: invention, in particular, relates to graft copolymer of butadiene/styrene copolymer grafted by (meth)acrylic monomer as modifier for polyvinylchloride. In order to reduce weight portion of elastomer in graft copolymer retaining its cross-linking degree and also to improve impact elasticity of modified polyvinylchloride, when performing polymerization of butadiene/styrene copolymer with monomer to be grafted in aqueous medium and in presence of lowsoluble radical-type initiator and high-molecular dispersant, butadiene/styrene copolymer is preliminarily mixed with acetone at weight ratio 1:(1.5-3) under no-heating conditions, then with low-soluble radical-type initiator and monomer to be grafted, after which acetone is distilled off, aqueous phase added, and graft polymerization is conducted at weight ratio of butadiene/styrene copolymer to grafting monomer (10-35): (90-65), the latter, in particular, being (meth)acrylic monomer. Graft copolymer thus obtained is characterized by weight portion of elastomer 10 to 35%, cross-linking degree 41 to 99%, average particle size 40 to 110 mcm, and impact elasticity of standard non-plasticized polyvinylchloride composition with graft copolymer of invention 30 to 88 kJ/sq.m. EFFECT: improved consumer's quality of products manufactured from modified polyvinylchloride. 5 cl, 37 ex