| 摘要 |
PURPOSE:To permit an inexpensive manufacture of a cap excellent in oxygen- and carbon dioxide-gas barrier character by forming a thermoplastic liquid crystal resin layer on the inner surface of the cap body. CONSTITUTION:A thermoplastic liquid crystal resin layer 2 is formed on the inner surface of a cap body 1, i.e., its side face coming in contact with a container. The cap body 1 may be an injection molding of any of the thermoplastic resin materials, e.g. polyethylene, polypropylene and polycarbonate. The thermoplastic liquid crystal resin 2 has the orientation of the molecules in a liquid state and is known as polyester liquid crystal resin, i.e., a copolymer of hydroxynaphthoic acid and hydroxybenzoic acid. This method permits an inexpensive manufacture of the cap having a highly oxygen- and carbon dioxide- gas barrier character. |
