초록 ▼

This invention teaches using blends of polyisobutylene and polypropylene copolymer in the formation of single layer films and multiple layer sheet materials. The films and sheet materials are useful as flexible packaging materials. The multiple layer sheet materials may be entirely polymeric or may

This invention teaches using blends of polyisobutylene and polypropylene copolymer in the formation of single layer films and multiple layer sheet materials. The films and sheet materials are useful as flexible packaging materials. The multiple layer sheet materials may be entirely polymeric or may include layers having nonpolymeric components, such as metal. The blends of polyisobutylene and polypropylene copolymer unexpectedly have the capability of being extruded through a slot die to form a film having a functionally useful mixture of its components. Thus the invention further includes methods of forming film-like layers of the blends of polyisobutylene and polypropylene copolymer.

대표청구항 ▼

A multiple layer sheet material, comprising: (a) a first polypropylene-based layer having two opposing surfaces, said first layer consisting essentially of greater than 60%, to 75% by weight polypropylene copolymer and conversely 25% to less than 40% by weight polyisobutylene, said polypropylene cop

A multiple layer sheet material, comprising: (a) a first polypropylene-based layer having two opposing surfaces, said first layer consisting essentially of greater than 60%, to 75% by weight polypropylene copolymer and conversely 25% to less than 40% by weight polyisobutylene, said polypropylene copolymer comprising 70 to 98 mole percent propylene moieties and conversely 30 to 2 mole percent ethylene moieties; (b) a second layer of polyamide having two opposing surfaces, said second layer being adhered, on one of its said surfaces to one of said surfaces of said first layer; (c) a third barrier layer having two opposing surfaces adhered on one of its said surfaces to the other said surface of said second layer of polyamide, the composition of said third layer comprising an ethylene vinyl alcohol copolymer; and (d) a fourth layer of a polyamide, having two opposing surfaces, adhered on one of its said surfaces to the other said surface of said third layer.