| abstract |
PURPOSE: To obtain an orientated material of polyester resin having improved degree of orientation and mechanical strength, by extruding a polyester resin having a specific unit in a molten state, followed by orientation. n CONSTITUTION: A polyester resin having an intrinsic viscosity of 0.35W1.4 dl/g comprising a dicarboxylic acid component consisting of not less than 80 mole % of a terephthalic acid unit, a glycol component consisting of not less than 80 mole % of an alkylene glycol unit alone, and not more than 20 mole % of units shown by the formula I, II, and III based on 100 mole % of the dicarboxylic acid is extruded at a temperature 20W40°C higher than its melting point, taken off at a draw ratio of I: not less than 20, and cooled to 10W100°C to be orientated. n COPYRIGHT: (C)1979,JPO&Japio |