US3900463A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing alkali carboxymethyl cellulose
Assignee: DKS Co Ltd
•
Filing: 1971-08-13
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Granted: 1975-08-19
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Expires: 1991-08-13
Abstract
Abstract A process for preparing alkali carboxymethyl cellulose having a uniform distribution of the degree of substitution which comprises treating cellulose with an etherifying agent selected from the group consisting of alkali monochloroacetate and lower alkyl monochloroacetate in the presence of a solvent system consisting of at least one organic solvent and water until the uniform distribution of the etherifying agent into the cellulose is attained, the etherifying agent being used in 0.4 to 2.0 mol per cellulose glucose anhydride unit, and adding an alkali to the resultant mixture, the alkali being used in not less than an equimolar amount to alkali monochloroacetate or not less than a twice molar amount to lower alkyl monochloroacetate, followed by treatment at a temperature from room temperature to reflux temperature until the etherification is completed.
Inventors
- 👤 Akira Yada
- 👤 Yuji Hori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:38
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/10; C08B11/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
A PROCESS FOR PREPARING ALKALI CARBOXYMETHYL CELLULOSE HAVING A UNIFORM DISTRIBUTION OF THE DEGREE OF SUBSTITUTION WHICH COMPRISES TREATING CELLULOSE WITH AN ETHERIFYING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI MONOCHLOROACETATE AND LOWER ALKYL MONOCHLOROACETATE IN THE PRESENCE OF WATER AND AT LEAST ONE ORGANIC SOLVENT THEREFOR, UNTIL THE UNIFORM DISTRIBUTION OF THE ETHERIFYING AGENT INTO THE CELLULOSE IS ATTAINED, AND THEN ADDING AN ALKALI TO THE RESULTING MIXTURE, SAID ETHERIFYING AGENT BEING PRESENT IN AN AMOUNT OF 0.4 TO 2.0 MOL PER CELLULOSE GLUCOSE ANHYDRIDE UNIT, AND WATER IS USED IN THE AMOUNT SATISFYING THE FOLLOWING INEQUALITY:
Claim 2
Dependent Claim
99 words
A PROCESS FOR PREPARING ALKALI CARBOXYMETHYL CELLULOSE HAVING A UNIFORM DISTRIBUTION OF THE DEGREE OF SUBSTITUTION WHICH COMPRISES TREATING CELLULOSE WITH AN ETHERIFYING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI MONOCHLOROACETATE AND LOWER ALKYL MONOCHLOROACETATE IN THE PRESENCE OF WATER AND AT LEAST ONE ORGANIC SOLVENT THEREFOR, UNTIL THE UNIFORM DISTRIBUTION OF THE ETHERIFYING AGENT INTO THE CELLULOSE IS ATTAINED, AND THEN ADDING AN ALKALI TO THE RESULTING MIXTURE, SAID ETHERIFYING AGENT BEING PRESENT IN AN AMOUNT OF 0.4 TO 2.0 MOL PER CELLULOSE GLUCOSE ANHYDRIDE UNIT, AND WATER IS USED IN THE AMOUNT SATISFYING THE FOLLOWING INEQUALITY:
Claim 3
Dependent Claim
14 words
The process according to claim 1, wherein the etherifying agent is lower alkyl monochloroacetAte.
Claim 4
Dependent Claim
17 words
The process according to claim 1, wherein water is used in the amount satisfying the following inequality:
Claim 5
Dependent Claim
22 words
The process according to claim 1 wherein the organic solvent is isopropanol, ethanol, acetone, benzene, or a mixture of ethanol and benzene.
Claim 6
Dependent Claim
23 words
The process according to claim 1 wherein said lower alkyl monochloroacetate is methyl monochloroacetate, ethyl monochloroacetate, propanol monochloroacetate, isopropanol monochloroacetate or butanol monochloroacetate.
Claim 7
Dependent Claim
141 words
A process for preparing alkali carboxymethyl cellulose having a uniform distribution of the degree of substitution which comprises treating cellulose with an etherifying agent selected from the group consisting of alkali monochloroacetate and lower alkyl monochloroacetate in the presence of water and at least one organic solvent therefor, until the uniform distribution of the etherifying agent into the cellulose is attained, the etherifying agent being used in an amount of 0.4 to 2.0 mol per cellulose glucose anhydride unit, and adding an alkali to the resultant mixture, the alkali being present in not less than an amount equimolar with alkali monochloroacetate or not less than a twice molar amount to lower alkyl monochloroacetate, followed by treatment at a temperature from room temperature to reflux temperature until the etherification is completed, said water being present in an amount satisfying the following inequality:
Claim 8
Dependent Claim
141 words
A process for preparing alkali carboxymethyl cellulose having a uniform distribution of the degree of substitution which comprises treating cellulose with an etherifying agent selected from the group consisting of alkali monochloroacetate and lower alkyl monochloroacetate in the presence of water and at least one organic solvent therefor, until the uniform distribution of the etherifying agent into the cellulose is attained, the etherifying agent being used in an amount of 0.4 to 2.0 mol per cellulose glucose anhydride unit, and adding an alkali to the resultant mixture, the alkali being present in not less than an amount equimolar with alkali monochloroacetate or not less than a twice molar amount to lower alkyl monochloroacetate, followed by treatment at a temperature from room temperature to reflux temperature until the etherification is completed, said water being present in an amount satisfying the following inequality:
Claim 9
Dependent Claim
14 words
The process according to claim 6, wherein the etherifying agent is lower alkyl monochloroacetate.
Claim 10
Dependent Claim
17 words
The process according to claim 6 wherein water is used in the amount satisfying the following inequality:
Claim 11
Dependent Claim
22 words
The process according to claim 6, wherein the organic solvent is isopropanol, ethanol, acetone, benzene or a mixture of ethanol and benzene.
Claim 12
Dependent Claim
23 words
The process according to claim 6 wherein said lower alkyl monochloroacetate is methyl monochloroacetate, ethyl monochloroacetate, propanol monochloroacetate, isopropanol monochloroacetate or butanol monochloroacetate.
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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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |