| 摘要 |
PURPOSE:To prepare resin particles giving a foam which is highly safe in terms of protection of the global environment while maintaining excellent characteristics of the base resin comprising an amorphous vinylidene chloride copolymer by impregnating the resin with a specific fluorinated hydrocarbon blowing agent using a specific impregnation aid. CONSTITUTION:100 pts.wt. amorphous vinylidene chloride copolymer (a copolymer of vinylidene chloride, an N-substd. maleimide, and a copolymerizable monomer; having a glass transition point of 85 deg.C or higher) is impregnated with 4-40 pts.wt., pref. 6-20 pts.wt., fluorinated hydrocarbon blowing agent [selected from the group consisting of monochlorodifluoroethane (R-142b, 0.06), difluoroethane (R-152a, 0), 2,2-dichloro-1,1,1-trifluoroethane (R123, 0.02), 1,1,1,2- tetrafluoroethane (R-134a, 0), and 2-chloro-1,1,1-trifluoroethane (R-124, 0.02); here in the parentheses are indicated the code name and ozone depleting power of each compd.] using an impregnation aid (having a dielectric constant of 5.0 or higher and a b.p. of 65 deg.C or lower; e.g. chloromethane) to give expandable vinylidene chloride resin particles. |
