Abstract: A process for the radical polymerization of ethylenically unsaturated monomers in an aqueous medium has (a) the starting solution used for the polymerization and the educts required for polymerization such as monomers, germ latex, buffering agents, emulsifiers and/or protective colloids are introduced into a pre-mixing device and thoroughly mixed, heated before being transferred to the polymerization vessel to the polymerization temperature, no initiator being used if a thermal radical initiator is used and only individual initiator components being used where a redox initiator system is used; (b) once the mixture has reached polymerization temperature, it is transferred to a polymerization vessel, the wall of which during the transfer and polymerization is maintained by cooling at a temperature below the polymerization temperature; polymerization is started by adding the thermal initiator or additional initiator components of the redox initiator system, the other educts being added at the start of and/or dur

Abstract: A process for the manufacture of vinyl chloride polymers or copolymers by microsuspension polymerization of vinyl chloride or vinyl chloride and up to 30% by weight, based on the total monomer content, of .alpha.-olefinically unsaturated monomers copolymerizable with vinyl chloride comprising the steps of:(1) dispersing the monomer or the monomer mixture in water in the presence of from 0.1 to 3% by weight, based on the total weight of the monomer content, of microsuspension dispersion auxiliaries and from 0.001 to 3% by weight, based on the total weight of the monomer content, of microsuspension monomer - soluble radical - initiators;(2) homogenizing said dispersion so that monomer droplets mostly having a mean diameter of from 0.1 to 3 .mu.

Abstract: The subject of the invention is a microsuspension polymerization in water of vinyl chloride, which is carried out in the presence of monomer-soluble radical-initiators and emulsifiers. According to the invention, from about 0.01 to 0.5% by weight, based on the weight of the water, of polymers containing mono-basic or dibasic carboxylic acid units and/or salts thereof are added. Furthermore, in a preferred embodiment, emulsifiers containing perfluorinated alkyl groups are also used. Stabilization of the microsuspension latex, which is per se sensitive to shearing action, and reduction in the amount of emulsifiers used are achieved.