Calendered polyester films or sheets having a haze value of less than five percent
US6551688B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2001 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Feb 28, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24413
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A calendered film or sheet of a polyester resin composition has a haze value of less than 5 percent. The polyester resin composition comprises a polyester having a crystallization half-time from a molten state of at least 5 minutes and an additive comprising (i) a fatty acid or a salt of a fatty acid containing more than 18 carbon atoms and (ii) an ester wax comprising a fatty acid containing more than 18 carbon atoms with an alcohol containing from 2 to 28 carbon atoms, wherein the ratio of the fatty acid or salt of the fatty acid to the ester wax is 1:1 or greater. Also, the present invention is a process for producing such calendered film or sheet having a haze value of less than 5 percent. The steps of the process comprise (1) calendering such polyester resin composition, (2) forming on a calendering roll a film or sheet from such polyester resin composition, and (3) removing the film or sheet from the calendering roll at an angle of less than 90° to form a film or sheet having a haze value of less than 5 percent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.