Method reducing UV absorption in ethylene glycols, water, and mixtures
US5770777A · kind A · utility
1Cited by
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20Claims
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Assignee
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Key dates
| Filing date | May 9, 1996 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | May 9, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C45/79
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Disclosed is a method of reducing the UV absorption of a solvent that comprises water, an ethylene glycol, or a mixture thereof, where the solvent contains at least 0.1 ppm of a dione, particularly 3-methyl-2-hydroxy cyclopent-2-eneone or its tautomer, 3-methyl-1, 2-cyclopentanedione. The solvent is passed through an anionic exchange resin containing strong base sites. The UV absorbance of the effluent from the anionic exchange resin can be monitored and, when it increases, the resin can be reactivated by passing an aqueous solution of a base through it.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.