| 摘要 |
Articles of cellular, rigid, polyvinyl chloride are made by expansion and hardening of a moulded and gelled mixture of polyvinyl chloride, an isocyanate, one or more blowing agents, and optionally one or more stabilisers; the process is carried out in a sealed chamber in an atmosphere of water vapour having a partial pressure of about 1 bar and a temperature of about 373 DEG K or more. Utilisation of such temperature and pressure parameters enables a considerable reduction to be obtained in the expansion and hardening treatment period. |
