Microporous film and process for production thereof
US4791144A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1987 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Jun 12, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/10
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a microporous polyproplene film comprising a propylene homopolymer, a copolymer of propylene with other copolymerizable monomer or a blend thereof, which has an intrinsic viscosity (.eta.) of 1.9 to 3.0 dl/g, especially 2.0 to 3.0 dl/g, as measured at 135.degree. C. in tetralin, said microporous film having a network structure comprising intercommunicating pores having a maximum pore size smaller than 1.mu. and an average pore size of 0.005 to 0.6.mu. and having a porosity of 30 to 90%, an air permeability of 5 to 500 sec/100 cc and a thickness of 5 to 200.mu., said microporous film being molecularly oriented by stretching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.