Patent US1387677A successfully refreshed from Google Patents.
Patent US4331812A successfully refreshed from Google Patents.
US4331812A
Expired / Lapsed
US
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Treatment of dibasic esters with alkali metal methylates
Assignee: EIDP Inc
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Filing: 1980-10-30
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Granted: 1982-05-25
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Expires: 2000-10-30
Abstract
Abstract Process for reducing the color forming tendency of alkanedioic acid methyl esters by contact with an alkali metal methylate.
Inventors
- 👤 Robert A. Smiley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:16
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/62
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
59 words
A method of reducing the color-forming tendency of methyl esters obtained from alkanedioic acids having 4-12 carbon atoms produced by the nitric acid oxidation of cycloaliphatic hydrocarbons selected from the class consisting of ketones, alcohols and mixtures of the foregoing which method consists of contacting said esters with an alkali metal methylate and thereafter recovering the thus treated esters.
Claim 2
Independent Claim
59 words
A method of reducing the color-forming tendency of methyl esters obtained from alkanedioic acids having 4-12 carbon atoms produced by the nitric acid oxidation of cycloaliphatic hydrocarbons selected from the class consisting of ketones, alcohols and mixtures of the foregoing which method consists of contacting said esters with an alkali metal methylate and thereafter recovering the thus treated esters.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the methylate is sodium methylate.
References Cited (Backward Citations)
US4076948A
Cited
US3642871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |