| 摘要 |
PURPOSE: To reduce a dependency of a peel-off strength on a sealing temperature by a method wherein an outer layer is made a biaxially oriented film of a polyester or the like, an intermediate layer is made of polyethylene, a sealant is made of a mixture of polyethylene and polystyrene, and the surface of the sealant is subjected to a corona discharge treatment. CONSTITUTION: In a cover tape for heat-sealing a plastic-made carrier tape with storage pockets continuously provided for containing electronic parts, an outer layer 2 is made of a biaxially oriented film of a polyester, polypropylene, or a nylon, and an intermediate layer 3 is made of polyethylene. A sealant 4 is a mixture containing 5-100 pts.wt. polystyrene having a melt flow rate 10-30g/10min per 100 pts.wt. of polyethylene having a melt flow rate of 10-30g/10min. The surface of the sealant is subjected to a corona discharge treatment to have a surface tension of 35-50dyne/cm. The visible light transmission of the cover tape 1 is adjusted to be not less than 75%. In this manner, ideal characteristics can be held. |
