Multi-layer resin films having excellent oxygen gas barrier properties and process for their production
US6489021B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2001 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Mar 12, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31928
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention provides a multi-layer resin film having excellent oxygen gas barrier properties, particularly even at high humidity, and further having no chlorine content. The multi-layer resin film of the present invention has a biaxially-stretched polypropylene resin film, an adhesive layer formed on at least one surface of the polypropylene resin film, and a polyvinyl alcohol resin layer formed on the adhesive layer, wherein the polyvinyl alcohol resin layer has a value of crystallinity parameter (CP (M//) ⊥) not less than 0.8. The multi-layer resin film of the present invention can be prepared by forming an adhesive layer on at least one surface of an unstretched polypropylene resin film; stretching the film in one direction; forming a polyvinyl alcohol resin layer on the adhesive layer; and stretching the film in another direction perpendicular to the direction of previous stretching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.