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AssigneeFuji Photo Film Co., Ltd.
InventorsMutsuo Akao, Makoto Kawamura
Estimating the term…
A packaging material for photographic photosensitive materials consisting essentially of a cushioning sheet having a density of less than 0.5 g/cm.sup.3, a wear-resistant heat-resistant flexible sheet having a Young's modulus of not less than 50 kg/mm.sup.2 provided on one side of the cushioning sheet, and a wear-resistant flexible sheet having a Young's modulus of not less than 50 kg/mm.sup.2 provided on the other side of the cushioning sheet, the outer most layer provided on said the other side having heat sealability, and the packaging material having complete light-shielding ability as a whole, and a light-shielding bag for photographic photosensitive materials made by fusion to join the layers having heat sealability in the above packaging material. The packaging material for photographic photosensitive materials can be heat-sealed entirely and can continuously be made into a bag automatically by a simple general purpose heat sealer, such as a heat sealing bar or a heat sealing belt, while retaining its physical strength and at a high productivity.
A packaging material for photographic photosensitive materials usable for packaging a roll or sheets of photographic film or photographic paper having a sharp edge and a weight of not less than 500 grams, said packaging material consisting essentially of a cushioning sheet having a density of less than 0.5 g/cm.sup.3 wherein the cushioning sheet is a foamed crosslinked polyolefin resin sheet having a thickness of 0.3 to 3 mm and an expansion ratio of 10 to 50 times, a wear-resistant and heat-resistant flexible sheet having a Young's modulus of not less than 50 kg/mm.sup.2 provided on one side of the cushioning sheet wherein the wear-resistant and heat-resistant flexible sheet is a metallized flexible sheet having a metal membrane with a thickness of 55 to 1200 angstroms, an oxygen permeability of not more than 50 cc/m.sup.2.24 hr.1 atm.20.degree. C. and a moisture permeability of not more than 5 g/m.sup.2.24 hr, and a wear-resistant flexible sheet having heat-sealability and a Young' s modulus of not less than 50 kg/mm.sup.2 provided on the other side of the cushioning sheet, wherein the wear-resistant heat-resistant flexible sheet has a greater heat resistance than the wear-resistant flexible sheet, and has a melting point higher than the wear-resistant flexible sheet by not less than 20.degree. C., an outer most layer provided on said other side having heat sealability, and the packaging material having complete light-shielding ability as a whole.
A light-shielding bag for photographic photosensitive materials in the form of a roll or sheets of photographic film or photographic paper having a sharp edge and a weight of not less than 500 grams, said light-shielding bag being made of a packaging material for photographic photosensitive materials consisting essentially of a wear-resistant and heat-resistant flexible sheet having a Young's modulus of not less than 50 kg/mm.sup.2 wherein the wear-resistant and heat-resistant flexible sheet is a metallized flexible sheet having a metal membrane with a thickness of 55 to 1200 angstroms, an oxygen permeabilty of not more than 50 cc/m.sup.2.24 hr.1 atm.20.degree. C. and a moisture permeability of not more than 5 g/m.sup.2.24 hr, a cushioning sheet having a density of less than 0.5 g/cm.sup.3 wherein the cushioning sheet is a foamed crosslinked polyolefin resin sheet having a thickness of 0.3 to 3 mm and an expansion ratio of 10 to 50 times, and a wear-resistant flexible sheet having a light-shielding ability and heat sealability laminated in this order from the outside each through or without an adhesive layer wherein the wear-resistant heat-resistant flexible sheet has a greater heat resistance than the wear-resistant flexible sheet, and has a melting point higher than the wear-resistant flexible sheet by not less than 20.degree. C.
Dependencies are inferred from the claim text.