Heat-sealing sheet material
AssigneeHosokawa Yoko Co., Ltd.
InventorSusumu Niwa
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Abstract
A heat-sealing sheet material can be obtained by forming, on one side of a sheet base material such as aluminum foil, a sealant layer composed of a graft copolymer comprising a trunk polymer of a 20 to 60% saponification product of an ethylene/vinyl acetate copolymer having a vinyl acetate content of 15 to 45% by weight and a branch polymer of an unsaturated carboxylic acid in a proportion of 10% by weight or less of the partially-saponified product. This sheet material exhibits excellent heat-sealing strength with respect to glass containers, and, moreover, there is almost no decrease in the sealing strength even when the material has been in contact with water. Accordingly, the sheet material is suitable as a sealing material for the opening rims of glass containers for water-containing food products such as jams and pickles.
Claims8
A heat-sealing sheet material which comprises a base sheet and a sealant layer formed on one side of the base sheet, said sealant being a graft copolymer comprising a trunk polymer of a 20 to 60% saponification product of an ethylene/vinyl acetate copolymer (EVA) of a vinyl acetate content of 15 to 45% by weight and a branch polymer of an unsaturated carboxylic acid in a proportion of 10% by weight or less of the graft-copolymer.
Dependencies are inferred from the claim text.