| 摘要 |
PROBLEM TO BE SOLVED: To contain a microbubble and thereby improve mechanical strength by containing an organic solvent through holding a thermoplastic polyester resin sheet in a vapor of an organic solvent and containing an inert gas through holding the polyester resin sheet in a high pressure inert gas. SOLUTION: A thermoplastic polyester resin sheet is held in a container filled with the vapor of an organic solvent whose compatibility with a resin is high. Next, the thermoplastic polyester resin sheet containing the organic solvent is loaded into a pressure container, and is caused to contain an inert gas by holding the polyester resin sheet in a high pressure inert gas atmosphere, and further, is heated under normal pressure to generate a bubble. The containing of the organic solvent into the resin sheet is enabled by holding the resin sheet in the vapor of the organic solvent. Therefore, it is possible to minimize the usage of the organic solvent to the allowable necessary extent and save on a manufacturing cost. In addition, after the containing of the organic solvent into the resin sheet, the eluation of an additive from the resin sheet and the dripping of a solvent droplet when the resin sheet is handled, never occur. |
