Cellulose acylate film, method of producing the same, cellulose derivative film, optically compensatory film using the same, optically-compensatory film incorporating polarizing plate, polarizing plate and liquid crystal display device
US8313814B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 2006 |
| Grant date | Nov 20, 2012 |
| Priority date | — |
| Expiry date | Feb 12, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31971
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of producing a cellulose derivative film, the method comprising: forming a film with a solvent cast method from a dope including a cellulose derivative satisfying following conditions (a) and (b): (a) at least one among three hydroxyl groups included in a glucose unit of cellulose is substituted by a substituent of which a polarizability anisotropy Δα represented as following Expression (1) is 2.5×10−24 cm3 or higher: Expression (1): Δα=αx−(αy+αz)/2, wherein αx, αy and αz is as defined in the specification; and (b) when a substitution degree by a substituent of which Δα is 2.5×10−24 cm3 or higher is PA, and a substitution degree by a substituent of which Δα is lower than 2.5×10−24 cm3 is PB, the PA and PB satisfy following Expressions (3) and (4): Expression (3): 2PA+PB>3.0; and Expression (4): PA>0.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.