| 摘要 |
PURPOSE:To obtain a molded foam usable as a lightweight engineering material which has an excellent balance between mechanical properties and heat resistance and is uniform in foam structure and mechanical property by subjecting a specific copolyester to foam molding. CONSTITUTION:Foam molding is conducted using a copolyester or a composition obtained by mixing a copolyester with at least one ingredient selected from a filler, an organic-polymer flame retardant, and a thermoplastic polymer. The copolyester is constituted by the structural units shown by formulae I to IV, with units I and II accounting for 80-93mol% of units I, II, and III, unit III accounting for 20-7mol% of units I, II, and III, and the molar ratio of unit I to unit II being 78:22 to 3:7. The copolyester has a melting point (Tm, deg.C) satisfying relation V (wherein X is the proportion (mol%) of unit III to units I, II, and III), has an inherent viscosity of 1.0-3.0dl/g, and shows melt anisotropy. Thus, a molded foam is obtained which has been greatly improved in anisotropy to show good isotropy in mechanical property and is useful as a lightweight engineering material. |
