| 摘要 |
Process for the prepn. of highly insulating polystyrene (copolymer) cellular plastic by (1) melting the polymer, pref. in an extruder, (2) adding and blending a blowing agent, pref. under pressure and (3) extruding the material through a mouthpiece whilst depressurising and cooling, uses a blowing agent comprising a chlorine-free halogenated hydrocarbon (e.g. HFC cpd.), low mol. wt. alcohol and water. |
