| abstract |
A polyorganosiloxane-based high-impact thermoplastic graft copolymer superior in impact resistance, light resistance, surface gloss and color fastness produced by the emulsion graft polymerization of at least one vinyl monomer on an emulsion-polymerized polyorganosiloxane which consists of n 90 to 99.8 mole % of an organosiloxane unit represented by the formula n n R'.sub.2 SiO.sub.2/2 (I) n n wherein R' is the same or different and denotes methyl, ethyl, propyl, or phenyl, n 0.1 to 10 mole % of a unit derived from a graft-linking agent, said unit being represented by the formula ##STR1## wherein; R 2 denotes methyl, ethyl, propyl, or phenyl; n denotes a number of 0, 1, and 2; and p denotes a number of 1 to 6, and n 0.1 to 10 mole % of a unit derived from a tetrafunctional silane crosslinking agent, said unit being represented by the formula n n SiO.sub.4/2 (III), n n said polyorganosiloxane showing a degree of swelling of 5 to 15 in toluene, and n said graft copolymer containing said polyorganosiloxane in an amount of 10 to 70% by weight; and a process for producing the said graft copolymer. |