PACKAGING MATERIAL FOR FLAT TYPE ELETROCHEMICAL CELL

摘要

A packaging material for a flat type electrochemical cell is provided to prevent cracks at a bent portion even in bending the inner edge of a seal part around an exterior body by keeping uniform flexibility and durability of a heat-adhesive resin layer even after the heat-adhesive resin layer is crystallized by a heat seal. A packaging material for a flat type electrochemical cell is composed of a base layer(6), a metal thin layer(7) having a chemically treated layer(7a) on at least one surface, an acid modified polyolefin layer(9), and a heat-adhesive resin layer(8), which are laminated in order. The acid modified polyolefin layer is a resin layer made of acid modified polyolefin resin. The heat-adhesive resin layer has a resin layer made of propylene resin. Propylene elastomer resin is mixed with acid modified polyolefin resin or polyolefin resin. Propylene elastomer resin is copolymer consisting of a constituent unit derived from propylene and a constituent unit provided with 2~20 carbons and derived from alpha-olefin except for propylene. A constituent unit derived from propylene is included over 50mol.% to the sum of a constituent unit derived from propylene and a constituent unit derived from alpha-olefin of 100mol.%. Shore hardness of the packaging material is 65~90. A melting point is 130~170°C. Density is 860~875kg/m^3. Glass transition temperature measured by a DSC(Differential Scanning Calorimeter) is -25~-35°C.