| 摘要 |
PURPOSE:To easily obtain a crystalline polymer oriented material having an especially large cross-sectional area of 0.1mm<2> and simultaneously satisfying both characteristics of high strength and high elasticity, by compressing a gel like film A obtained by casting a crystalline polymer solution to remove a part of the solvent contained in the film A before orienting said film A. CONSTITUTION:A crystalline polymer solution is obtained by a method wherein a crystalline polymer is added to a selected solvent suitable for said polymer in an adequate wt. ratio and the resulting mixture is heated to the decomposition temp. or less of said crystalline polymer and stirred and mixed by a stirrer to dissolve said crystalline polymer. This crystalline polymer solution is case to form a gel like film A which is, in turn, compressed at a temp. of a melting temp. or less of said film A to form a film B while a part of the solvent contained in the film A is removed. If compression molding is performed at the melting temp. or more of said film A, high magnification orientation in the succeeding orientation process can not achieved and a high strength and high elasticity oriented material is not obtained. In order to form an oriented material having a circular cross-section from the compressed material. said compressed material is passed through a die D provided with an orifice having a circular cross-section to perform pull-off orientation. |
