US4298728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing hydroxyethyl ethers of cellulose
Assignee: Aqualon Co
•
Filing: 1980-06-03
•
Granted: 1981-11-03
•
Expires: 2000-06-03
Abstract
Abstract In preparation of hydroxyethyl ethers of cellulose, ethylene oxide efficiency of the reaction and solubility characteristics of the product are improved by using alkali cellulose which has been prepared in the presence of boric acid or a boric acid salt.
Inventors
- 👤 Thomas G. Majewicz
- 👤 Walter S. Ropp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:54
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/08; C08B1/00; C08B1/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
70 words
In the process for preparing hydroxyethyl cellulose wherein a cellulose furnish is reacted with an alkali metal hydroxide to prepare alkali cellulose and said alkali cellulose is slurried in a lower aliphatic alcohol and reacted with ethylene oxide, the improvement which comprises carrying out the alkali cellulose preparation in the presence of about 1 to 30%, based on the weight of cellulose of boric acid or a boric acid salt.
Claim 2
Dependent Claim
70 words
In the process for preparing hydroxyethyl cellulose wherein a cellulose furnish is reacted with an alkali metal hydroxide to prepare alkali cellulose and said alkali cellulose is slurried in a lower aliphatic alcohol and reacted with ethylene oxide, the improvement which comprises carrying out the alkali cellulose preparation in the presence of about 1 to 30%, based on the weight of cellulose of boric acid or a boric acid salt.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the boric acid or boric acid salt is present in amount equal to about 3 to 20%.
Claim 4
Dependent Claim
15 words
The process according to claim 2 wherein the lower aliphatic alcohol is tertiary butyl alcohol.
Claim 5
Dependent Claim
14 words
The process according to claim 2 wherein the lower aliphatic alcohol is isopropyl alcohol.
Claim 6
Dependent Claim
17 words
The process according to claim 1 wherein the reaction is carried out in the presence of borax.
Claim 7
Dependent Claim
17 words
The process according to claim 3 wherein the reaction is carried out in the presence of borax.
Claim 8
Dependent Claim
17 words
The process according to claim 4 wherein the reaction is carried out in the presence of borax.
Claim 9
Dependent Claim
78 words
In the process for preparing a mixed cellulose ether wherein a cellulose furnish is reacted with an alkali metal hydroxide to prepare alkali cellulose and said alkali cellulose is slurried in a lower aliphatic alcohol and reacted with ethylene oxide and a second etherifying reagent, the improvement which comprises carrying out the alkali cellulose preparation in the present of about 1 to 30 %, based on the weight of cellulose, of boric acid or a boric acid salt.
Claim 10
Dependent Claim
78 words
In the process for preparing a mixed cellulose ether wherein a cellulose furnish is reacted with an alkali metal hydroxide to prepare alkali cellulose and said alkali cellulose is slurried in a lower aliphatic alcohol and reacted with ethylene oxide and a second etherifying reagent, the improvement which comprises carrying out the alkali cellulose preparation in the present of about 1 to 30 %, based on the weight of cellulose, of boric acid or a boric acid salt.
Claim 11
Dependent Claim
16 words
The process of claim 8 wherein the second etherifying agent is a long chain alkyl halide.
Claim 12
Dependent Claim
17 words
The process according to claim 9 wherein the reaction is carried out in the presence of borax.
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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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |