| 摘要 |
The invention relates to the preparation of paste-making polymers of vinyl chloride by discontinuous polymerisation in the presence of a predispersion of a) an alkali metal salt or ammonium salt of a fatty acid, of an alkylsulphonic acid, of an alkylarylsulphonic acid or of a sulphosuccinate, b) a C12-C20alkanol, c) water, and if appropriate d) a monomer-soluble catalyst, the predispersion being prepared with more than 60 to 80% by weight of the total required amount of emulsifier (amount of surfactant), whereas the remainder of the emulsifier or of a component forming the emulsifier is metered in to the polymerisation mixture after a conversion of 10 to 60% by weight batchwise or continuously as an aqueous solution. The polymers obtained lead to pastes of especially low viscosity, even at high shear loading, and produce predominantly open-celled flexible foams with good rebound resilience.
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