| 摘要 |
879,145. Solutions containing graft copolymers. POLYPLASTIC. Feb. 3, 1958 [Feb. 2, 1957], No. 3457/58. Class 2(6). A polymer is dissolved in a solvent in which it is not normally soluble by preparing a solution in the solvent of a graft copolymer of the monomer of the polymer to be dissolved and another monomer the homopolymer of which is soluble in the solvent, and then introducing the insoluble polymer into the solvent. The graft copolymer may be prepared in situ in the solvent by polymerization of either the monomer producing the insoluble polymer or the monomer producing the soluble polymer in the presence of the corresponding preformed polymer. Alternatively, the graft copolymer may be prepared in bulk, solution, emulsion or suspension. The graft polymerization is preferably carried out by the ozonization process described in Specification 791,453, but the reaction may also be effected by means of redox catalysts. The insoluble polymer may be added as such to the solution of the graft copolymer, or the monomer giving rise to the insoluble polymer may be polymerized in the aforesaid solution with the aid of catalysts such as benzoyl peroxide, a mixture of benzoyl peroxide and dimethyl aniline and azobisisobutyronitrile. The examples describe the preparation of : (1) a carbon tetrachloride solution of polyacrylonitrile and a polystyrene-acrylonitrile graft copolymer; (2) a benzene solution of a polymer mixture as in (1); (3) a carbon tetrachloride solution of polyvinyl chloride and a polystyrene-vinyl chloride graft copolymer; (4) a chloroform solution of polyvinylidene chloride and a polyvinyl acetate-vinylidene chloride graft copolymer; and (6) a carbon tetrachloride solution of polyacrylonitrile and a polyacrylonitrile-styrene graft copolymer. |
