| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyimide oriented film without causing defective orientation due to mechanical or thermal stress by using a specified amt. of an arom. diamine having a methylene group on the principal chain. SOLUTION: At the time of producing a compsn. for a liq. crystal alignment film contg. polyamic acid obtd. by allowing an arom. diamine to react with tetracarboxylic acid anhydride, an arom. diamine having a methylene group on the principal chain is used by 10-55mol% of the arom. diamine. A bendable structure is introduced into the structure of the principal chain of polyimide and mechanical or thermal stress applied to a film to be oriented by treatment after film formation, especially by rubbing is easily relieved. The film is efficiently oriented and liq. crystal orienting property is improved. The pref. amt. of the arom. diamine having a methylene group on the principal chain is 10-50mol%, especially 10-30mol%. |
