| 摘要 |
PURPOSE:To provide the display board which has high hardness, is resistant to flawing and is highly resistant to chemicals by using polybutyrene naphthalene dicarboxylate. CONSTITUTION:This display board is molded by using polyester consisting of naphthalene dicarboxylic acid, more preferably naphthalene-2,6-dicarboxylic acid as an essential acid component and 1,4-butanediol as an essential glycol component, i.e., the polyester, the whole or the greater part of the repeating units of which is the butyrene naphthalene dicarboxylate. This polyester is obtd. by subjecting naphthalene dicarboxylic acid and/or its functional deriv. and butyrene glycol and/or its functional deriv. to polycondensation by using a process for production of arom. polyester. The higher degree of crystallization and higher hardness are resulted by setting mold temp. at the time of the molding at 80 to 140 deg.C. |
