| 摘要 |
1,166,223. Vinyl nitrile polymerization. TOYO RAYON K.K. 23 Jan., 1968 [23 Jan., 1967], No. 3591/68, Heading C3P. The process for preparing by aqueous dispersion polymerization a vinyl copolymer containing at the most 40% of a vinyl monomer of formula wherein R is hydrogen or a methyl group is characterized in that 0À01-5 parts by weight of a higher saturated aliphatic alcohol, C n H 2n+1 OH (wherein n is an integer of 12-18) is added per 100 parts of monomer. Preferably the copolymer comprises not more than 40% of a cyanated vinyl monomer (see above formula) and not less than 60% of either (wherein R and R<SP>1</SP> are hydrogen or a methyl group) or (wherein R 1 is hydrogen or a methyl group and R 2 is an alkyl group of 1-4 carbon atoms). Preferred monomers are acrylonitrile, styrene and methyl methacrylate. In the examples, (1) styrene and acrylonitrile and/or methacrylonitrile are copolymerized using azobisisobutyronitrile, n-dodecyl mercaptan and barium sulphate, and in the presence of cetyl alcohol and optionally also with stearyl alcohol, (2) styrene and acrylonitrile are copolymerized using lauroyl peroxide, n-dodecyl mercaptan and polyvinyl alcohol, and in the presence of lauryl alcohol, myristyl alcohol or cetyl alcohol, (3) as (2) except that the free radical forming component is a mixture of azobisisobutyronitrile and 2,2<SP>1</SP> - azobis - (2,4 - dimethylvaleronitrile); and (4) styrene, acrylonitrile and methyl methacrylate are copolymerized using azobisisobutyronitrile, n-dodecyl mercaptan and barium sulphate, in the presence of cetyl alcohol. Bead polymer is obtained which is compression moulded into sheets. The products are resistant to coloration. |
