Process of centrifugally removing inorganic compounds from polyester glycol recovery bottoms
US5158651A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1990 |
| Grant date | Oct 27, 1992 |
| Priority date | — |
| Expiry date | Jun 11, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C29/76
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for removing inorganic compounds from glycol recovery still bottoms resulting from the manufacture of poly(ethylene terephthalate), the novel process using a small amount of phosphoric acid to precipitate the antimony and then removing the titanium dioxide and antimony compound by a centrifuge. The novel process for removing the inorganic compounds from the recovery polyester bottoms includes the steps of distilling ethylene glycol from the spent glycol until the remaining bottoms have a solids concentration from about 15% to about 45%; adding phosphoric acid to the bottoms to form an antimony compound and removing the antimony and titanium precipitates from the bottoms by a centrifuge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.