| 摘要 |
PROBLEM TO BE SOLVED: To realize a multilayered film, which has a stable heat seal strength (or a peel strength) and the peeled part of which shows not string but favorable appearance by a method wherein the total thickness of a peel ply and polyethylene-based resin layer is set to have the specified value. SOLUTION: This multilayered film 10 for heat sealant is formed by laminating a supporting layer 1 made of polypropylene, a peel ply 2 made of a blend of low density polyethylene and polypropylene and a polyethylene layer to one another in the order named. In addition, the total thickness of the peel ply 2 and the polyethylene layer 3 is set to have 2.5-5μm. If the total thickness is below 2.5μm, heat seal stability is not enough. If the total thickness exceeds 5μm, the string develops at the peeled part. The peel ply 2 is required so as to have a strong adhesion to the polyethylene layer 3 at the formation of a filmy peel ply and weak strippability to the supporting layer 1 made of polypropylene, which tends to cause condensate failure between the peel ply 2 and the supporting layer 1. In order to satisfy the above-mentioned requirements, the blending ratio of the low density polyethylene to the polypropylene in the peel ply is set to be 1:2.0-8.5.
|
