Liquid crystal display device comprising an alignment film that includes a first alignment film formed of a precursor of polyamide acid or polyamide acid ester and a second alignment film underlying the first alignment film wherein the first alignment film accounts for between 30% and 60% of the alignment film
US8648988B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 16, 2011 |
| Grant date | Feb 11, 2014 |
| Priority date | — |
| Expiry date | Oct 13, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2323/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention enables forming a photo-alignment film having a large LC anchoring strength in an IPS type liquid crystal display device. An alignment film is adapted to have a two-layer structure including a photo-alignment film and an alignment film with enhanced film strength. The photo-alignment film is formed of a precursor of polyamide acid ester, 80 percent or more of which is polyamide acid ester including cyclobutane. The alignment film with enhanced film strength is formed of a precursor of polyamide acid. After irradiating the substrate with ultraviolet light for photo-alignment, the substrate is heated. Thus, it is possible to achieve a high LC anchoring strength of the alignment film as the whole for photo-alignment, without degrading the mechanical strength of the alignment film with enhanced film strength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.