PURPOSE: To enhance the flotage retaining power by a structure wherein the balloon concerned is made of composite film having a biaxially oriented gas barrier resin layer and a heat-sealing layer, both of which have specified layer thickness respectively.
CONSTITUTION: The balloon concerned is made of composite film having a biaxially oriented gas barrier resin layer with the layer thickness of 3-30μm and a heat-sealing layer with the layer thickness of 5-30μm. As the biaxially oriented gas barrier resin layer, biaxially oriented film of gas barrier resin, film, which is produced by coextruding gas barrier resins and biaxially stretching them, and film, which is produced by vacuum-depositing metal such as aluminum or the like onto the films just mentioned above, the exampled. Further, as the gas barrier resin, vinyl alcohol-based resin and vinylidene chloride-based resin are exampled. Furthermore, as the heat sealing layer, high- density polyethylene, medium-density polyethylene, low-density polyethylene and the like are exampled. Thus, both the flotage retaining power and the shape retaining power can be improved.
MATSUMOTO JUNICHI
HIROFUJI SATOSHI
| JPS62111734A | 1987-05-22 | |||
| JPS58166046A | 1983-10-01 | |||
| JPS5822163A | 1983-02-09 | |||
| JPS5343198A | 1978-04-19 | |||
| JPS516276A | 1976-01-19 |