Preparation of gas permeable porous film
US4814124A · kind A · utility
89Cited by
7References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1987 |
| Grant date | Mar 21, 1989 |
| Priority date | — |
| Expiry date | Jan 20, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/47
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A gas permeable porous film which is prepared by stretching a film made from a mixture containing a polyolefin resin and an inorganic filler at least uniaxially and possesses a rugged pattern on its surface. One process for producing the film comprises forming the aforesaid mixture into a film, providing on the surface of the film a rugged pattern, stretching the resulting film at least uniaxially, and forming on the stretched film thus-formed a rugged pattern by means of a heated emboss roll and simultaneously allowing the stretched film to contract.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.