Negative birefringent polyimide films
US5480964A · kind A · utility
56Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1994 |
| Grant date | Jan 2, 1996 |
| Priority date | — |
| Expiry date | Apr 21, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.