| 摘要 |
<p>PURPOSE: To obtain a cover coat ink which is excellent in heat resistance and processibility and has a low water absorption by molding a specific arom. polyamic acid polymer, imidating the molding, and dissolving it in an org. good solvent. CONSTITUTION: This ink is obtd. from an arom. polyimide polymer represented by formula I (wherein Ar1 and Ar2 are each a divalent org. group; Ar3 is a tetravalent org. group; l and n are each 1 or higher; and m is 0, 1, or higher) and is produced by molding an arom. polyamic acid polymer represented by formula II (wherein Ar4 and Ar5 are each a divalent org. group; Ar6 is a tetravalent org. group; s and u are each 1 or higher; and t is O, 1, or higher) into films, threads, or blocks, imidizing the molded polyamic acid polymer, and dissolving the resulting polyimide molding in an org. good solvent therefor. The polyimide molding can be dissolved more easily when it is crushed with a mixer, etc. When the imidation is incomplete, it can be completed by further heating.</p> |
