Method for producing ο-phthalate polyester polyols with low cyclic ester content
US9487467B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 2012 |
| Grant date | Nov 8, 2016 |
| Priority date | — |
| Expiry date | Mar 18, 2033 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09J175/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for producing a polyester polyol is disclosed. The method comprises reacting phthalic anhydride with a diol selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, polyethylene glycols having a number average molecular weight within the range of 200 g/mol to 600 g/mol, and mixtures thereof at a diol to phthalic anhydride molar ratio within the range of 1.1 to 1.6. The resulting o-phthalate polyester polyol has a hydroxyl value in the range of 18 to 400 mg KOH/g, an acid value in the range of 0.2 to 5.0 mg KOH/g, and 1 wt. % or less of cyclic esters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.