Polyethylene superthin film and a process for the production of the same
US4600633A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1985 |
| Grant date | Jul 15, 1986 |
| Priority date | — |
| Expiry date | Apr 29, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A polyethylene superthin film having a thickness of at most 3 .mu.m, a tensile modulus of at least 2000 kg/cm.sup.2, a breaking strength of at least 500 kg/cm.sup.2 and a haze of at most 10% is produced by heating and dissolving polyethylene having a weight average molecular weight of at least 5.times.10.sup.5 in a solvent, forming a gel sheet from the resulting solution, subjecting the gel sheet to a solvent removal treatment to adjust the amount of the solvent in the gel sheet to 10 to 80% by weight, heating and stretching the sheet, removing the residual solvent therefrom and then subjecting the stretched product to a compressing treatment at a temperature of at most the melting point of the polyethylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.