Process for the polymerization of vinyl chloride according to the microsuspension process

Claim 1

In the process for the manufacture of vinyl chloride polymers or copolymers according to the microsuspension process by the polymerization of vinyl chloride monomers or vinyl chloride monomers and up to 20% by weight, based on the vinyl chloride content, of α-olefinically unsaturated monomers copolymerizable with vinyl chloride in water in the presence of monomer-soluble radical-initiators using emulsifiers in the pre-homogenized aqueous phase, the improvement consisting of employing from 0.01 to 0.5% by weight, based on the weight of the water, of a water-soluble acidic polymer comprising a homopolymer of an acid selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and itaconic acid, or an acid anhydride thereof, or a copolymer of said acid with up to 80% by weight of monoolefinically unsaturated monomer copolymerizable with said acid, or a water-soluble salt thereof in the pre-homogenized aqueous phase, the emulsifiers comprising in part from about 0.001 to 0.1% by weight, based on the weight of the water, of an emulsifier having at least one perfluorinated alkyl group having a chain length of from about 6 to 20 carbon atoms.