Abstract: A resin composition can impart high insulating properties, sealing properties, and moldability to a battery packaging material. A resin composition minimizes cracks when used in the sealant layer of a battery packaging material and a heat seal section of the material is bent, and can impart high insulating properties. A resin composition for use in the sealant layer of a battery packaging material contains: at least one of a propylene-ethylene random copolymer having a melting point of 156° C. or more and an ethylene content of 5 mass % or less and a propylene-ethylene block copolymer having a melting point of 158° C. or more and an ethylene content of 7 mass % or less; and a polyolefin elastomer having a melting point of 135° C. or more. A resin composition for the sealing layer of a battery packaging material contains a polyolefin resin having an isotactic fraction of 99% or less.

Abstract: Presented is battery packaging material which is made of a laminate including, as the essentials, a base material layer, a metal layer and a sealant layer in this order. When a product obtained by packaging a battery element with the packaging material in a hermetically sealed state through heat sealing is heated, the packaging material delaminates at least at a part of the interface between the metal layer and the outside surface of the sealant layer with the hermetically sealed state being kept, and thereafter works so as to make the product unsealed.

Abstract: A resin composition can impart high insulating properties, sealing properties, and moldability to a battery packaging material. A resin composition minimizes cracks when used in the sealant layer of a battery packaging material and a heat seal section of the material is bent, and can impart high insulating properties. A resin composition for use in the sealant layer of a battery packaging material contains: at least one of a propylene-ethylene random copolymer having a melting point of 156° C. or more and an ethylene content of 5 mass % or less and a propylene-ethylene block copolymer having a melting point of 158° C. or more and an ethylene content of 7 mass % or less; and a polyolefin elastomer having a melting point of 135° C. or more. A resin composition for the sealing layer of a battery packaging material contains a polyolefin resin having an isotactic fraction of 99% or less.

Abstract: Presented is battery packaging material which is made of a laminate including, as the essentials, a base material layer, a metal layer and a sealant layer in this order. When a product obtained by packaging a battery element with the packaging material in a hermetically sealed state through heat sealing is heated, the packaging material delaminates at least at a part of the interface between the metal layer and the outside surface of the sealant layer with the hermetically sealed state being kept, and thereafter works so as to make the product unsealed.