| 摘要 |
The mechanical resistance of a polycellular body obtained by the expansion of a gas within a plastic material, e.g. polyvinyl chloride, is increased by adding a plasticizing agent to the plastic material before producing the cellular body and transforming this plasticizer, by chemical reaction with a substance introduced into the body or formed therein, into a material of greatly reduced plasticizing power. The plasticizing agent may be organic acid generating substances such as the anhydrides of organic acids or ketenes, e.g. phthalic, maleic or acetic anhydride, the plasticizing power of which is decreased by the introduction of water, or monomeric or lower polymeric styrene or methyl methacrylate, the plasticizing power of which is decreased by polymerization in the presence of a catalyst such as oxygen formed by incorporating in the starting mix a metal peroxide such as barium peroxide which reacts with subsequently introduced water. In the examples, mixes of polyvinyl chloride, azoisobutyric acid dinitrile, phthalic anhydride and (1) p tricresyl phosphate, (2) turpentine oil, barium peroxide and methyl methacrylate are converted into cellular bodies and then treated with steam so as to introduce water into the body. |
