Dense articles formed from tetrafluoroethylene core shell copolymers and methods of making the same
US9644054B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2014 |
| Grant date | May 9, 2017 |
| Priority date | — |
| Expiry date | Dec 19, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2207/53
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A dense article that includes a dense TFE copolymer film is provided. The dense TFE copolymer film includes a first endotherm between about 50° C. and about 300° C., a second endotherm between about 320° C. and about 350° C., and a third endotherm between about 350° C. and about 400° C. To form the dense article, a core shell TFE copolymer is formed into a pellet, ram extruded into a tape, dried into a dried preform, and then stretched into a dense TFE copolymer film that exhibits improved physical and mechanical properties. The dense TFE copolymer film is produced directly from the dried preform at a deformation temperature less than about 335° C. and without increasing the porosity of the dried preform, as would conventionally be done in expansion processes. The dense TFE copolymer films have a methane permeability less than about 20 μg*micron/cm2/min. The dense articles have a void volume less than about 20%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.