公开(公告)号：DE2212962A1

公开(公告)日：1973-09-20

申请号：DE2212962

申请日：1972-03-17

Applicant: BASF AG

Inventor： DEUSCHEL WALTER DR ,  GULBINS ERICH DR ,  HAUSS ALFRED DR ,  LAUSBERG DIETRICH DR ,  SIGMUND WILHELM DR

IPC: C08F14/00 ,  C08F2/00 ,  C08F2/18 ,  C08F14/06 ,  C08F3/30

Abstract: 1414714 Suspension polymerization BADISCHE ANILIN- & SODA-FABRIK AG 16 March 1973 [17 March 1972] 12765/73 Heading C3P In the polymerization of vinyl chloride, optionally with up to 30% by weight of one or more comonomers, in aqueous suspension in the presence of a free-radical initiator and a watersoluble protective colloid in a stirred reactor, the polymerization mixture is heated to the desired polymerization temperature in a heat-up stage which constitutes not more than one third of the time required for the full polymerization cycle, whereupon polymerization is carried out in a polymerization stage at a substantially constant temperature, while (a) using one or more free-radical initiators having a half-life at 50‹ C. of less than 10 hours, (b) maintaining the polymerization mixture at a pH of less than 8 during the heat-up stage, and (c) maintaining the temperature of the reactor walls at not more than 20‹ C. above the temperature of the polymerization mixture during the heat-up stage and maintaining the temperature of the reactor walls at a lower value than that of the polymerization mixture during the polymerization stage. At least 30% of the monomers are grafted on to the protective colloid in the heat up stage.