Biaxially oriented polyoxymethylene film
US4946930A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Jul 20, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/91
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
There is disclosed a biaxially oriented film formed of film forming composition comprising a polyoxymethylene polymer in which the major constituent of the main chains of said polymer each of consists substantially of repeating units of oxymethylene group --CH.sub.2 --O--, said film being characterized in that, when said film is remelted at a temperature above the melting point of said film and the resulting melt is recrystallized isothermally at 140.degree. C. into a solid in film form, the number of polyoxymethylene spherulites in the crystal structure at the surface of the resulting film would be at least 50 per 0.1 mm.sup.2 area of the resulting film surface, as measured with a polarizing microscope through cross-polarizers, and a process for manufacturing the same.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.