MANUFACTURE OF PASTIFIABLE POLYMER OF VINYL CHLORIDE OR MIXTURE COMPRISING VINYL CHLORIDE AND MONOMER COPOLYMERIZABLE WITH VINYL CHLORIDE

摘要

1. A process for the preparation of a paste-making polymer of vinyl chloride or a mixture of vinyl chloride containing up to 30% by weight of copolymerisable monomer by batchwise polymerisation in the presence of a water-soluble or monomer-soluble catalyst and in the presence of a predispersion comprising a) 0.2 to 3.0 per cent by weight, based on the monomer, of an alkali metal salt or ammonium salt of a branched or unbranched fatty acid containing 12 to 18 C atoms, of a branched or unbranched alkylsulphonic acid containing 10 to 20 C atoms, of an alkylarylsulphonic acid containing 8 to 18 C atoms in the branched or unbranched alkyl chain, or of a sulfosuccinic acid ester containing 6 to 14 C atoms in the alcohol moiety, b) 50 to 200 per cent by weight, based on the surfactant employed, of a straight-chain or branched C12 -C20 -alkanol, c) water, and optionally d) a monomer-soluble catalyst, characterised in that the predispersion is prepared containing only 30 to 80 per cent by weight of the total amount of emulsifier (amount of surfactant) required and is added to the polymerisation batch, whereas the remainder of the emulsifier or of a component forming the emulsifier is added to the polymerisation mixture batchwise or continuously as an aqueous solution after a conversion of 10 to 60 per cent by weight has been reached.