| 摘要 |
1402323 Graft polymers DOW CHEMICAL CO 21 Sept 1972 [22 Sept 1971] 43790/72 Heading C3G A graft polymer comprises the polymerization product of (a) a non-equimolar random copolymer of from 65 to 95 parts by weight of an alkenyl aromatic monomer containing up to 12 carbon atoms and having the alkenyl group attached directly to the benzene nucleus and from 35 to 5 parts of an unsaturated dicarboxylic acid anhydride and (b) from 5 to 35 parts of a rubber per 100 parts of (a) plus (b) the rubber having an inherent viscosity of 0À9 to 2À5 dl/g. and being in the form of a plurality of particles having diameters in the range of from 0À02 to 3fl microns dispersed throughout the matrix of the copolymer, at least a major portion of the rubber particles containing occlusions of the copolymer. The graft polymer is prepared by a process in which a solution of the rubber and alkenyl aromatic monomer is agitated, polymerization is initiated therein and the anhydride is added at a rate substantially less than the rate of polymerization of the alkenyl aromatic monomer, the addition being continued in a manner such that monomeric anhydride is present throughout the polymerization. Examples are given in which (i) styrene and maleic anhydride are grafted on to styrene-butadiene block copolymer, polybutadiene or butadienestyrene rubber and (ii) styrene, maleic anhydride and methyl acrylate are grafted on to said block copolymer. Samples of the grafted block copolymer are exposed to ethylene diamine vapour or solution and sprayed with an automobile primer or lacquer containing said diamine. |
