| 摘要 |
PURPOSE:To obtain an aromatic polyimide tubular product having excellent machanical characteristics by a method in which a polyimide precursor doping liquid is extruded into a tubular form, a core material having a higher thermal expansion coefficient than polyimide is inserted into the hole of the coagulum, the precursor dope tube is imidized and dried for solidification, and the core material is removed out. CONSTITUTION:An aromatic polyimide precursor is dissolved in an organic polar solvent, the solution is extruded into a tubular form, and 5-80wt% of the organic polar solvent in the tubular doping liquid is extracted and removed by a coagulation liquid compatible with the organic polar solvent. A core material of a higher thermal expansion coefficient than polyimide is inserted into the hole of the tubular dope liquid coagulum and dried by heating for solidification, and the polyimide precursor is imidized. To imidize the precursor completely, it should be heated at 300 deg.C or higher for 20min or more. After the solidification, the core material is removed out to obtain an aromatic polyimide tubular product. |
