| 摘要 |
PURPOSE:To obtain the titled foam which is uniform and has a high expansion ratio and a large cross-sectional area, by blending a polyfunctional glycidyl ester compd., a polyfunctional carboxylic acid anhydride and a specified blowing agent with a thremoplastic polyester resin, extruding the mixture and expanding it. CONSTITUTION:0.03-2.5mol% of a polyfunctional glycidyl ester compd. such as diglycidyl terephthalate is blended with a thermoplastic polyester resin having an arom. dicarboxylic acid content of 85% or above and an intrinsic viscosity of 0.4-1, such as polyethylene terephthalate. The mixture is melt-kneaded. 0.01- 2mol% of a polyfunctional carboxylic acid anhydride such as pyromellitic dianhydride and a blowing agent having a b.p. of 150 deg.C or below under atmospheric pressure such as methylene chloride are added thereto. The resulting mixture is extruded and expanded. EFFECT:A uniform, fine foam having excellent mechanical strength and resistance to heat and chemicals at an expansion ratio of 20-30 can be obtd. |
