Process for adding methine UV light absorbers to PET prepared by direct esterification
US7541407B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 2004 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Oct 10, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for incorporating a UV light absorbing compound into a polyester prepared using direct esterification of reactants selected from a dicarboxylic acid and a diol. The method comprises reacting the reactants in an esterifying reactor under conditions sufficient to form an esterified product including at least one of an ester, an oligomer, or mixture having an ester and a mixture of low molecular weight polyester; polymerizing the esterified product in a polycondensation reactor to form a polyester; and adding the UV absorbing compound to the esterified products when at least 50% of the carboxy groups initially present in the reactants have been esterified to obtain a yield of UV absorbing compound incorporated into the polyester of greater than 25%. Articles utilizing the UV protected polyester prepared by the method of the invention are additionally disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.