| 摘要 |
PROBLEM TO BE SOLVED: To obtain a glass-fiber-reinforced polyester composition having a high intrinsic viscosity and the capability of giving a product with improved mechanical properties by incorporating a polyester resin with pyromellitic dianhydride so as to obtain a composition having a specified intrinsic viscosity. SOLUTION: A polyester resin obtained by the polycondensation of an aromatic dicarboxylic acid (derivative) or a naphthalenedicarboxylic acid and a 2-12C diol is mixed with 0.05-2 wt.% pyromellitic diahydride, 10-50 wt.% 0.2-1 mm long glass fiber treated with a surface treating agent such as vinyltrichlorosilane or Cr-methacrylate, and, optionally, additives such as a stabilizer, an antioxidant, a plasticizer, a plasticizer, a nucleator, a pigment, and a flame retardant to obtain a polyester resin composition having an intrinsic viscosity of 0.7 dl/g or above. This composition is melt-kneaded at 300 deg.C or below, desirably, 260-280 deg.C for 120 sec or below, desirably, 20-100 sec, and then molded. The molding is crystallized by heat treatment at 100 deg.C or above, desirably, 140-170 deg.C. |
