| 摘要 |
PURPOSE:To obtain a foamed resin molding of improved isotropy by forming the molecule of the resin from aromatic dicarboxylic acid units, glycol units, aromatic diol units and hydroxybenzoic acid units in a specified molar ratio and form-molding the resin so that the cell fraction may fall within a specified range. CONSTITUTION:An aromatic condensation polymer which can develop optical anisotropy when melted is prepared by forming its molecule by combining units selected from among aromatic dicarboxylic acid units (A) of formula I (wherein R<1> is a bivalent aromatic ring residue), glycol units (B) of formula II (wherein R<2> is a bivalent aliphatic residue), aromatic diol units (C) of formula III (wherein R<3> is a bivalent residue having an aromatic ring) and hydroxybenzoic acid units (D) of formula IV in such amounts that units B are present in an amount of below 25mol% based on the total of units B, C and D. This polymer is mixed with a blowing agent, and the mixture is foam- molded to produce a foamed resin molding having a cell fraction of 5-50vol.% and improved in isotropy of the crystalline polymer. |
