Polyester film, process for producing the same and use thereof
US8030434B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2006 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Feb 1, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24802
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a polyester film produced by melt-extruding a polyester composed of a dicarboxylic acid unit and a diol unit, wherein 1 to 80 mol % of the diol unit is a unit containing a cyclic acetal skeleton, and the polyester film has an in-plane retardation of 20 nm or less at a wavelength of 550 nm. The polyester film is an optically isotropic polyester film which is easily produced by an extrusion-molding method and has an economical advantage. The polyester film is useful for production of optical members or optical products such as phase difference films, protective films for polarizing plates, light diffusion films, lens sheets, anti-reflection films and optical information recording media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.