Patent US4754064A successfully refreshed from Google Patents.
US4754064A
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Preparation of cyclohexane dicarboxylic acids
Assignee: BP Corp North America Inc
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Filing: 1983-10-24
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Granted: 1988-06-28
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Expires: 2003-10-24
Abstract
Abstract Cyclohexane dicarboxylic acids are prepared by hydrogenating phthalic acids in presence of a rhodium catalyst wherein a portion of the product stream is isolated and recycled to the reactor.
Inventors
- 👤 Lawrence D. Lillwitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:28
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/36
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
127 words
An improved process for preparation of a cyclohexane dicarboxylic acid from a phthalic acid reactant which comprises the steps of (a) hydrogenating said phthalic acid reactant in a polar solvent in the presence of a supported rhodium catalyst at a temperature within the range of 90° C. to 140° C. and a pressure of from 300 to 1800 psig, (b) filtering the catalyst from reactor effluent at a temperature within the range of from 15° C. to 110° C., (c) crystallizing the filtrate at a temperature of from 15° C. to 60° C., (d) the improvement in combination therewith comprising recycling back to the reactor mother liquor containing from about 5 (wt)% to about 25 (wt)% reaction product based on the weight of the phthalic acid reactant.
Claim 2
Dependent Claim
127 words
An improved process for preparation of a cyclohexane dicarboxylic acid from a phthalic acid reactant which comprises the steps of (a) hydrogenating said phthalic acid reactant in a polar solvent in the presence of a supported rhodium catalyst at a temperature within the range of 90° C. to 140° C. and a pressure of from 300 to 1800 psig, (b) filtering the catalyst from reactor effluent at a temperature within the range of from 15° C. to 110° C., (c) crystallizing the filtrate at a temperature of from 15° C. to 60° C., (d) the improvement in combination therewith comprising recycling back to the reactor mother liquor containing from about 5 (wt)% to about 25 (wt)% reaction product based on the weight of the phthalic acid reactant.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein said solvent is selected from the group consisting of water, ethyl acetate and tetrahydrofuran.
Claim 4
Dependent Claim
36 words
The process of claim 1 wherein said phthalic acid is isophthalic acid, said solvent is water, said supported rodium catalyst is 5 (wt)% rhodium-on-carbon and catalyst:isophthalic acid weight ratio is from about 1:20 to about 1:50.
Claim 5
Dependent Claim
37 words
The process of claim 1 wherein said phthalic acid is terephthalic acid, said solvent is ethyl acetate, said supported rhodium catalyst is 5 (wt)% rhodium-oncarbon and catalyst:terephthalic acid weight ratio is from about 1:3 to about 1:5.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein said phthalic acid is present in the form of an aqueous slurry.
Claim 7
Dependent Claim
29 words
The process of claim 1 wherein said temperature is within the range of from about 100° C. to about 125° C. and pressure is from 500 to 1500 psig.
Claim 8
Dependent Claim
32 words
The process of claim 1 wherein support of said supported catalyst is selected from the group consisting of activated carbon, alumina, dehydrated zirconium oxide, chromium oxide, kieselguhr, bentonite, asbestos and silica gel.
Claim 9
Dependent Claim
22 words
The process of claim 1 wherein support of said supported catalyst is selected from the group consisting of activated carbon and alumina.
Claim 10
Dependent Claim
25 words
The process of claim 1 wherein said mother liquor recycled back to said reactor contains from about 5 (wt)% to about 25 (wt)% reaction product.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein said process is a batch process.
Claim 12
Dependent Claim
12 words
The process of claim 1 wherein said process is a continuous process.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |