| abstract |
PURPOSE:To contrive improvement of heat resistance, mechanical characteristics and oil resistance of aromatic polyester film by melting and extruding for film forming the aromatic polyester prepared from aromatic dicarbonic acid, aromatic hydroxy carbonic acid and a specific quantity of 4,4'-dihydroxy diphenyl and other compound. CONSTITUTION:The aromatic polyester obtained from compound (A) selected from aromatic dicarbonic acid and its derivatives, compound (B) selected from aromatic hydroxycarbonic acid and its derivatives, compound (C) selected from hydroxy compound and its derivatives (total of C and D), 4,4'-dihydroxy diphenyl of 20-70mol% and its derivatives, and compound (D) selected from dihydroxy compound of, likely, 30-80mol% and its derivatives is melted and extruded to cast film. 50mol% min of the above compound B is preferred to be selected from p-hydroxy benzoic acid and its derivatives. The polyester consisting mainly of this p-hydroxy benzoic acid is excellent in crystallinity. Workability, strength and heat resistance can be improved by combining aromatic carbonic acid and dihydroxy compound. |