COVER MATERIAL

摘要

A cover material used for a container has a seal part formed from a polypropylene resin. The cover material includes a base material and a sealant layer. The sealant layer has a laminated structure obtained through lamination of a first thermoplastic resin layer, adhesive to the base material, and a second thermoplastic resin layer, adhesive to the seal part formed from the polypropylene resin. Thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer satisfy: thickness of first thermoplastic resin layer≦thickness of second thermoplastic resin layer. The layer of the second thermoplastic resin has a dispersion structure obtained by dispersing, in the first thermoplastic resin, the second thermoplastic resin that is non-compatible or partially compatible to the first thermoplastic resin such that a ratio l/s of a domain longer diameter l and a domain shorter diameter s of the second thermoplastic resin is within 1.5≦l/s≦10.

主权项

1. A cover material used for a container formed from a polypropylene resin or a container having a seal part formed from a polypropylene resin, the cover material comprising
a base material and a sealant layer, the sealant layer having a laminated structure obtained through lamination of a layer of a first thermoplastic resin having adhesiveness with respect to the base material, and a layer of a second thermoplastic resin having adhesiveness with respect to the seal part formed from the polypropylene resin, thicknesses of the layer of the first thermoplastic resin and the layer of the second thermoplastic resin satisfying: a thickness of the layer of the first thermoplastic resin a thickness of the layer of the second thermoplastic resin, and the layer of the second thermoplastic resin having a dispersion structure obtained by dispersing, in the first thermoplastic resin, the second thermoplastic resin that is non-compatible or partially compatible with respect to the first thermoplastic resin such that a ratio l/s of a domain longer diameter L and a domain shorter diameter s of the second thermoplastic resin falls in a range of 1.5≦s/s≦10.