Porous polyester film
US6287680A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1999 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Dec 7, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A porous polyester film comprising a composition comprising a polyester resin and a thermoplastic resin incompatible with the polyester resin, and a number of voids formed by dispersing the incompatible thermoplastic resin to provide particles in the polyester resin and stretching same, wherein the incompatible thermoplastic resin comprises a polyolefin resin, and the film satisfies the following requirements (a) to (c): PA1 (a) an apparent specific gravity of not more than 1.3; PA1 (b) an average size d of dispersed particles of the polyolefin resin of not more than 15 .mu.m; and PA1 (c) a ring crush strength G (unit:kg/mm) and a film thickness t (unit:mm) satisfying the following formula EQU G>15.times.t.sup.3 is provided. According to the invention, a film having superior properties derived from a porous structure (e.g., cushioning property, low dielectric property, light weight) and good handling property.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.