| 摘要 |
PROBLEM TO BE SOLVED: To improve antistatic characteristics of a laminate and adhesion and peeling properties of a cover material by a method wherein initial impact strength based on a loop stiffness method is a specific value, stiffness strength is at most the initial impact strength, and a relation between the stiffness strength and elapsed time after start of measurement is made specifically proportional. SOLUTION: A laminate 1 of a cover material is obtained by laminating a heat resistant base material layer 2, an adhesive layer 3, an intermediate layer 4, and a heat sealant layer 5 in this order. The laminate is within a range of 5-20g in initial impact strength P based on a loop stiffness method, its stiffness strength (f) is at most the initial impact strength P, and a relation between the stiffness strength (f) and elapsed time after start of measurement (t) (t is at least 3min) is proportional, and its proportional constant (a) satisfies -0.1<=a<0. Consequently nerve of the laminate is large, and when the cover material is peeled off, interlayer peeling between the intermediate layer and the heat sealant layer, or cohesive failure peeling inside the heat sealant layer is generated. Then, good peeling properties of low zipping up can be obtained. |
