| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion battery exterior material, inhibiting whitening during forming and having superior heat sealing resistance.SOLUTION: A lithium ion battery exterior material includes: a base material layer 1b; and an adhesive layer 2b, an aluminum layer 3b provided with a corrosion prevention treated layer 4b, and an adhesive resin layer 5b, which are sequentially laminated on one surface of the base material layer. The adhesive resin layer contains an acid-modified polyolefin resin and a miscible elastomer dispersed in the acid-modified polyolefin resin at a dispersed phase size of 1 nm or more and less than 1 μm. When, in a test piece of the lithium ion battery exterior material having a width of 15 mm, the luminosity before drawing on the adhesive resin layer side is defined as L*1, and the luminosity after being drawn by 150% is defined as L*2, the luminosity difference &Dgr;L* before and after drawing, which is determined as L*2-L*1, is 25 or less. |
