METHOD FOR PRODUCTION OF ETHYLENE-VINYL ACETATE COPOLYMERS IN MULTIZONE TUBULAR REACTOR Russian patent published in 2000 - IPC

FIELD: polymer production. SUBSTANCE: method consists in high-pressure radical copolymerization of ethylene with vinyl acetate in reactor wherein reaction mixture is cooled in each reaction zone with hot water supplied into reactor jacket. Radical initiator is fed into each reaction zone and unreacted reactants are separated from copolymer in high- and low- pressure recycle systems, whereas high- and low-pressure recycle mixtures are added to ethylene-vinyl acetate stream directed into reactor. Working characteristics of resulting copolymer are improved because of its higher homogeneity achieved by supplementary vinyl acetate added into reaction mixture stream in the initial part of each but the first reactor zone, amount of which being found from equation: G_va=K*G_rm*Cq, wherein G_va is amount of supplementary vinyl acetate in each zone, kg/hr; G_rm amount of reaction mixture in each zone, kg/hr; C content of vinyl acetate in the mixture, wt %; and q is conversion of reaction mixture in zone, wt %; and K is constant equal to (0.90-1.3)/100 wt %. EFFECT: increased homogeneity of copolymer. 1 dwg, 1 tbl, 10 ex