| 摘要 |
PROBLEM TO BE SOLVED: To provide a low heat shrinking polyimide film improved in shrinking property by heat and its efficient manufacturing method. SOLUTION: This low heat shrinking polyimide film comprises a polyimide using 4,4'-oxydianiline and 3,4'-oxydianiline as diamines, and has shrinkage after a heat treatment at 200°C for one hour of not higher than 0.07% in both MD direction and TD direction, and in this manufacturing method of the low heat shrinking polyimide film, 10-90 mol% 4,4'-oxydianiline and 90-10 mol% of 3,4'-oxydianiline based on pyromellitic acid dianhydride and a diamine are polymerized and a polyamic acid solution is obtained, it is casted or extruded in a film, dried, and heat-treated, and the thus obtained polyimide film is heat-treated while keeping the tensile strength in the direction of the film length not lower than 1 kg/m but not higher than 10 kg/m, then a treatment for cooling is carried out. COPYRIGHT: (C)2007,JPO&INPIT |
