Porous polytetrafluoroethylene film and process for preparation thereof
US5772884A · kind A · utility
87Cited by
5References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1994 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Dec 22, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249978
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A porous polytetrafluoroethylene film which is excellent as an air filter used in clean rooms in a semiconductor industry, which is suitable for the collection of microparticles floating in a gas such as air and exhibits a low pressure drop is provided. The film has an average pore size of from 0.2 to 0.4 .mu.m and exhibits a pressure drop of from 20 to 50 mmH.sub.2 O when air is passed through it at a flow rate of 5.3 cm/sec. The film is prepared by stretching biaxially unsintered polytetrafluoroethylene at specific temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.