Film having gas permeability
US6348271B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1999 |
| Grant date | Feb 19, 2002 |
| Priority date | — |
| Expiry date | Dec 2, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31909
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An object of the present invention is to provide a drawn polypropylene film as a wrapping material that has transparency and mechanical properties sufficient as a wrapping material yet having the needed gas permeability for maintaining the freshness of the enclosed goods and additionally enables control of permeability of gases to a certain proportion if needed even if secondary steps such as perforation processing, etc., are eliminated. The present invention provides a polypropylene film drawn at least monoaxially which comprises a propylene resin composition comprising a propylene polymer component and a copolymer component containing ethylene and propylene, wherein a content of the copolymer component is 7 to 70% by weight based on the weight of the composition, and the film has a thickness [D1] of 10 to 100&mgr;m and has the following characteristics (1) to (3):(1) [TH2O] (a permeability of water vapor)=9 to 50 (unit: g/m2·24 Hr, in accordance with JIS Z-0208),(2) [TO2] (a permeability of oxygen gas)=600-12,500 (unit: nmol (STP)/m2·s·100 kPa, in accordance with JIS K-7126A),(3) [Tethylene] (a permeability of ethylene gas)=600-22,500 (unit: nmol (STP)/m2&mid…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.