US3719663A
Expired / Lapsed
US
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Preparation of cellulose ethers
Assignee: Hercules LLC
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Filing: 1971-06-07
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Granted: 1973-03-06
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Expires: 1991-06-07
Abstract
Abstract An improved process is provided for preparing cellulose ethers of the viscosity desired. Their viscosity is regulated during or after the etherification reaction used in their preparation. The viscosity regulating agents used are an organic hydroperoxide in conjunction with a metal catalyst. Now preferred are tert butyl hydroperoxide in conjunction with a cobalt or manganese salt.
Inventors
- 👤 E Klug
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:35
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20; C08B11/22; C08B11/02; C08B11/04; C08B11/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
80 words
In the preparation of a cellulose ether by reaction of a mixture of alkali and cellulose with an ether-ifying agent, the improvement which comprises regulating the viscosity of the cellulose ether by adding to the reaction mixture,per part of cellulose, 0.002 to 0.5 part of an or-ganic hydroperoxide and 10 to 100 parts of a transition metal, per million parts of cellulose, and conducting said reaction in the presence thereof, said metal being added in the form of a salt.
Claim 2
Dependent Claim
80 words
In the preparation of a cellulose ether by reaction of a mixture of alkali and cellulose with an ether-ifying agent, the improvement which comprises regulating the viscosity of the cellulose ether by adding to the reaction mixture,per part of cellulose, 0.002 to 0.5 part of an or-ganic hydroperoxide and 10 to 100 parts of a transition metal, per million parts of cellulose, and conducting said reaction in the presence thereof, said metal being added in the form of a salt.
Claim 3
Dependent Claim
54 words
Process of reducing the viscosity of a cellu-lose ether which comprises heating same in the presence of per part of cellulose, 0.002 to 0.5 part of an organic hydro-peroxide and 10 to 100 parts of a transition metal per million parts of cellulose ether, said metal being added in the form of a salt.
Claim 4
Dependent Claim
54 words
Process of reducing the viscosity of a cellu-lose ether which comprises heating same in the presence of per part of cellulose, 0.002 to 0.5 part of an organic hydro-peroxide and 10 to 100 parts of a transition metal per million parts of cellulose ether, said metal being added in the form of a salt.
Claim 5
Dependent Claim
83 words
In the preparation of a cellulose ether by reaction of a mixture of alkali and cellulose with an etherifying agent, the improvement which comprises regulating the viscosity of the cellulose ether by adding to the reaction mixture, per part of cellulose, 0.002 to 0.5 part of an organic hydroperoxide and 10 to 100 parts of manganese or cobalt per million parts of cellulose and conducting said reaction in the presence thereof, said manganese or cobalt being added in the form of a salt.
Claim 6
Dependent Claim
83 words
In the preparation of a cellulose ether by reaction of a mixture of alkali and cellulose with an etherifying agent, the improvement which comprises regulating the viscosity of the cellulose ether by adding to the reaction mixture, per part of cellulose, 0.002 to 0.5 part of an organic hydroperoxide and 10 to 100 parts of manganese or cobalt per million parts of cellulose and conducting said reaction in the presence thereof, said manganese or cobalt being added in the form of a salt.
Claim 7
Dependent Claim
12 words
Process of claim 1 wherein the organic hydroperoxide is tert butyl hydroperoxide.
Claim 8
Dependent Claim
23 words
Process of claim 1 wherein the cellulose ether is hydroxypropyl cellulose, carboxymethylcellulose or ethyl cellulose and the organic hydroperoxide is tert butyl hydroperoxide.
Claim 9
Dependent Claim
57 words
Process of reducing the viscosity of a cellulose ether which comprises heating same in the pre-sence of, per part of cellulose ether, 0.002 to 0.5 part of an organic hydroperoxide, and 10 to 100 parts of manganese or cobalt per million parts of cellulose ether, said manganese or cobalt being added in the form of a salt.
Claim 10
Dependent Claim
57 words
Process of reducing the viscosity of a cellulose ether which comprises heating same in the pre-sence of, per part of cellulose ether, 0.002 to 0.5 part of an organic hydroperoxide, and 10 to 100 parts of manganese or cobalt per million parts of cellulose ether, said manganese or cobalt being added in the form of a salt.
Claim 11
Dependent Claim
12 words
Process of claim 6 wherein the organic hydroperoxide is tert butyl hydroperoxide.
Claim 12
Dependent Claim
22 words
Process of claim 6 wherein the cellulose ether is hydroxypropyl cellulose, carboxymethylcellulose ether cellulose and the organic hydroperoxide is tert butyl hydroperoxide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |