| abstract |
A process for producing an emulsion graft copolymer, which comprises grafting a vinyl aromatic monomer and a comonomer onto a rubber latex in the presence of an iron (II) redox system as polymerization catalyst and coagulating the graft copolymer latex with an alkaline earth metal compound, characterized in that the pH of the coagulated slurry is adjusted to a value ranging from 8 to 12 a) by addition of an alkali metal hydroxide to the obtained slurry after coagulation, b) by addition of an alkali metal hydroxide to the graft copolymer latex before coagulation, or c) by coagulating the graft copolymer latex with an alkaline earth metal hydroxide, with the proviso that the solidified product of the slurry obtained according to a), b) or c) is not washed with acidified water in a subsequent processing step. Graft copolymers are used e.g. for reinforcement of natural rubber, modification of rubber-based adhesives, in fibres, or in films. |