| 摘要 |
PROBLEM TO BE SOLVED: To obtain a resin compsn. for coating having a good adhesion property to glass substrates and color filters, coatability, transparency and orientability in addition to heat resistance and chemical resistance by using a specific polyimide resin. SOLUTION: The polyimide resin contg. diamine having sulfone and/or sulfide on the main chain at >=30mol% of the total molar number of the diamine and contg. aliphat. and/or alicyclic tetracarboxylic acid dianhydride at >=30mol% of the total molar number of the acid dianhydride is used. As a result, the resin compsn. has the good light transparency and orientability. Further, a high-concn. and low-viscosity soln. is prepd. by a heat treatment and half esterification of the tetracarboxylic acid dianhydride, by which the use of the compsn. as a resin for coating and a liquid crystal oriented film in common use as a protective film for LCD(liquid crystal display) having an excellent flattening function is made possible. Consequently, the differences in level of color filters, TFTs, common electrodes, etc., are eliminated and, therefore, flat substrates are obtd. The orientation defect which is heretofore resulted from the ruggedness of the substrates is eliminated and the domain and contrast ratio are improved. |
