prov:value
| - In Japanese Patent Application Laid-Open No. 5-2105, as the material of an annular film constituting the film material, for example, thermoplastic resins and thermosetting resins such as polyethylene, polypropylene, polyvinyl chloride, polyamide, polystyrene, polyisobutylene, polycarbonate, polyvinilydene chloride, polyvinyl acetal, polymethyl methacrylate, polyacrylonitrile, polyimide, cellulose-
|