| 摘要 |
Method of preparation of latex of copolymers by polymerisation in microsuspension comprises: (i) reacting at least one monomer (A), chosen from 1-8C alkyl (meth)acrylates, with at least one vinyl ester of mono- or polycarboxylic acid with, eventually, a crosslinking or grafting agent, in presence of "seeding" polymer (P1) based on vinyl chloride previously prepared by polymerisation in microsuspension containing at least one organosoluble initiator; and (ii) eventually, introducing vinyl chloride with copolymerisable monomer for polymerisation on the previously prepared copolymer. Also claimed are latex produced by claimed method, copolymers produced from it, and plastisols, anti-shock additives, and foams produced from the copolymers. Preferably both stages of the process are carried out in presence of second "seeding" polymer, (P2); which is prepared in emulsion and which has particle size smaller than that of (P1). Second stage of process is carried out in presence of water-soluble initiator, preferably alkali metal or ammonium persulphate. Emulsifying agent is added before and/or during and/or after polymerisation, and speed of polymerisation is increased by activating initiator which is mixed with "seeding" polymers. Monomer (A) is selected from butyl acrylate and methyl acrylate.
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