Low birefringence film
US6808780B2 · kind B2 · utility
2Cited by
9References
36Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Oct 26, 2004 |
| Priority date | — |
| Expiry date | Apr 4, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31909
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a coextruded film comprising a transparent polymeric inner core layer of thickness less than 250 &mgr;m and two peelable outer polymeric layers wherein the inner layer constitutes a low enough proportion, less than 40%, of the total film thickness and exhibits a low enough melt flow index value to achieve a birefringence of not more than 1×10−4 nm/nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.