摘要 |
PURPOSE:To provide a resin film having excellent mechanical properties such as tear resistance and suitable for use as an electrical insulating film, containing a block copolymer composed of a polyphenylene sulfide and a polysulfone as an essential ingredient. CONSTITUTION:A polyphenylene sulfide mainly composed of a structural unit of formula I is copolymerized with a polysulfone composed of structural units of formulas II, III, etc. to produce a block copolymer. The copolymer alone or a mixture thereof with a polyphenylene sulfide and/or a polysulfone is fed to an extruder, etc. and molded into a film. The film is oriented and heat-treated to obtain the desired resin film. In this way, a film having excellent tear resistance, etc. can be obtd. as compared with films obtd. from a simple blend of a polyphenylene sulfide and a polysulfone. |