US3818071A
Expired / Lapsed
US
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Reduction of acidity in the production of esters
Assignee: Imperial Chemical Industries Ltd
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Filing: 1971-02-18
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Granted: 1974-06-18
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Expires: 1991-02-18
Abstract
Abstract The residual acidity of the product of an esterification process is reduced by contacting it with steam and a finely divided solid alkali such as sodium carbonate at a temperature in excess of 100*C. The process is particularly applicable to plasticiser esters such as dialkyl phthalates and possesses the added advantage of cleanly removing a titanium catalyst if the latter has been used in the esterification process.
Inventors
- 👤 J Chilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:12
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/60
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
41 words
The process of claim 1 in which the carboxylic acid is adipic acid, azelaic acid, sebacic acid, a phthalic acid, a hydrogenated phthalic acid, phthalic anhydride, hemimellitic acid, trimellitic acid, trimesic acid or an anhydride of hemimellitic, trimellitic or trimesic acid.
Claim 2
Dependent Claim
16 words
The process of claim 1 in which wet steam at a temperature of 120*C is used.
Claim 3
Dependent Claim
118 words
The process of claim 1 in which the ester product is derived by: a. heating phthalic anhydric or orthophthalic acid with a titanium catalyst and an alkanol selected from the group consisting of butanol, isoheptanol, iso-octanol, 2-ethylhexanol, nonanol, decanol, tridecanol and a mixture of alkanols containing 7 to 9 carbon atoms derived from olefine mixtures by the OXO process until a temperature of 220* to 270*C is attained, the alkanol being in 10 to 30 mole percent excess of the stoichiometric and thereafter, b. solid sodium carbonate is added, c. the pressure is reduced, d. steam is admitted when the temperature has fallen to 200* to 210* and, e. excess alcohol is finally removed at 140* to 210*C.
Claim 4
Dependent Claim
21 words
The process of claim 2 in which the ester product is derived from an alkanol containing 4 to 14 carbon atoms.
Claim 5
Dependent Claim
16 words
The process of claim 1 in which the temperature is in the range 100* to 270*C.
Claim 6
Dependent Claim
34 words
The process of claim 1 in which the solid alkali is added at a temperature of 240* to 250*C under reduced pressure and the steam is subsequently introduced when the temperature falls to 200*C.
Claim 7
Dependent Claim
21 words
The process of claim 1 in which 0.1 to 10.0 kilograms of solid alkali are added per ton of ester product.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |