| 摘要 |
The invention relates to a process for the preparation of an emulsifier-free copolymer latex by emulsion polymerisation of a monomer mixture containing from 2 to 10% by weight of olefinically unsaturated carboxylic acids and from 90 to 98% by weight of a plurality of monomers which can be copolymerised therewith, in the presence of a polymerisation initiator. In order to prepare an emulsifier-free latex which is free from microcoagulates in a one-step process in a reactor, a) from 2 to 5% by weight of at least one olefinically unsaturated dicarboxylic acid dissolved in the majority of the total amount of water is initially introduced and adjusted to a pH of from 3.0 to 6.0 by addition of alkali metal hydroxide, b) this mixture is heated to a temperature of from 30 to 100@C, preferably from 80 to 90@C, c) the polymerisation is initiated by injecting from 15 to 25% of the total amount of initiator, of from 0.5 to 3.0% by weight, necessary for the polymerisation d) a nonaqueous stream of a monomer mixture containing - based on the total amount of monomer - from 5 to 30% by weight of acrylonitrile and from 63 to 93% by weight of other monomers which can be copolymerised with acrylonitrile and olefinically unsaturated dicarboxylic acid is fed in continuously, e) an aqueous stream containing the remainder of the initiator and the remainder of the alkali metal hydroxide is simultaneously fed in continuously. where the reactor contents at a pH of 3.0 to 6.0 and a temperature of from 30 to 100@C, preferably from 80 to 100@C, ... until virtually complete... Original abstract incomplete.
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