HERMETICALLY SEALING FILM FOR METAL CONTAINER

摘要

PURPOSE:To enable the high frequency welding to a metal container, to keep strong seal strength and hermetical sealability and to prevent the release from an aluminum foil layer by laminating a polyester hot-melt layer to the aluminum foil layer as a high frequency welding layer through a polyethylene terephthalate layer. CONSTITUTION:A hermetically sealing film for a metal container is formed by laminating a high frequency welding layer to an aluminum layer and welded to the opening part of the metal container through the high frequency welding layer by a high frequency induction heating system to hermetically seal the opening part of the metal container. Herein, the thickness of the aluminum foil layer 11 is pref. 7-40mum and a polyethylene terephthalate layer 13 is pref. laminated to the aluminum foil layer 11 in a thickness of 5-40mum and a polyester hot-melt layer 12 is laminated to the layer 13 pref. in a thickness of 5-40mum as the high frequency welding layer. Since hot-melt polyester having a low m.p. and having a large number of polar groups in its molecule is used in the high frequency welding layer, strong seal strength and hermetical sealability can be kept.