Patent US4339574A successfully refreshed from Google Patents.
US4339574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of alkyl cellulose
Assignee: Henkel AG and Co KGaA
•
Filing: 1980-07-07
•
Granted: 1982-07-13
•
Expires: 2000-07-07
Abstract
Abstract This invention is directed to a method for the continuous production of alkyl cellulose by reacting alkali cellulose with alkylating agents in the presence of inert liquids, wherein: (a) powdered cellulose is reacted with aqueous-alcoholic alkali metal hydroxide solution at temperatures of from about 20° to 80° C. to form alkali cellulose; (b) oxygen is completely removed from the alkali cellulose reaction mixture of step (a) and the water content is reduced to about 2.5 to 6.0 moles per anhydroglucose unit; and (c) the reaction mixture from step (b) is reacted with at least a stoichiometric amount, but not more than with a molar excess of up to about 50%, based on the alkali metal hydroxide, of an alkylating agent in an inert liquid boiling at a temperature of from about 80° to 160° C., the reaction being carried out continuously in stirred tanks-in-series with 2 to 10 units.
Inventors
- 👤 Willi Wust
- 👤 Hasso Leischner
- 👤 Wilfried Rahse
- 👤 Franz-Josef Carduck
- 👤 Norbert Kuhne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:29
CPC Classifications
C; C08; C08B; C08B17/00; C08B17/06; C08B11/00; C08B11/02; C08B11/193
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
156 words
A method for the continuous production of alkyl cellulose by reacting alkali cellulose with alkylating agents in the presence of inert liquids, wherein: (a) powdered cellulose in an inert organic liquid is continuously reacted with aqueous-alcoholic alkali metal hydroxide solution at temperatures of from about 20° to 80° C. to form alkali cellulose; (b) oxygen is continuously completely removed from the alkali cellulose reaction mixture of step (a) and the water content is continuously reduced to from about 2.5 to 6.0 moles per anhydroglucose unit; and (c) the reaction mixture from step (b) is reacted with at least a stoichiometric amount, but not more than with a molar excess of up to about 50%, based on the alkali metal hydroxide, of an alkylating agent in an inert liquid boiling at a temperature of from about 80° to 160° C., the reaction being carried out continuously in a cascade of stirred tanks-in-series with 2 to 10 units.
Claim 2
Independent Claim
156 words
A method for the continuous production of alkyl cellulose by reacting alkali cellulose with alkylating agents in the presence of inert liquids, wherein: (a) powdered cellulose in an inert organic liquid is continuously reacted with aqueous-alcoholic alkali metal hydroxide solution at temperatures of from about 20° to 80° C. to form alkali cellulose; (b) oxygen is continuously completely removed from the alkali cellulose reaction mixture of step (a) and the water content is continuously reduced to from about 2.5 to 6.0 moles per anhydroglucose unit; and (c) the reaction mixture from step (b) is reacted with at least a stoichiometric amount, but not more than with a molar excess of up to about 50%, based on the alkali metal hydroxide, of an alkylating agent in an inert liquid boiling at a temperature of from about 80° to 160° C., the reaction being carried out continuously in a cascade of stirred tanks-in-series with 2 to 10 units.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein step (a) takes place at a temperature of from about 30° to 60° C.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein in step (b) the water is reduced to from about 3.5 to 4.0 moles per anhydroglucose unit.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein the powdered cellulose has a mean particle size diameter of from about 20 to 120μ.
Claim 6
Dependent Claim
21 words
The method of claim 4, wherein the powdered cellulose has a mean particle size diameter of from about 40 to 60μ.
Claim 7
Dependent Claim
17 words
The method of claim 1, wherein the inert organic liquid is toluene, xylene, or a mixture thereof.
Claim 8
Dependent Claim
14 words
The method of claim 1, wherein the cascade comprises a series of separate vessels.
Claim 9
Dependent Claim
21 words
The method of claim 7, wherein in the series each vessel after the first vessel is larger than the preceding vessel.
Claim 10
Dependent Claim
16 words
The method of claim 1, wherein the cascade comprises a column subdivided into chambers (compartment reactor).
Claim 11
Dependent Claim
151 words
In the method for the preparation of alkyl cellulose by alkalizing cellulose to form alkali cellulose, alkylating the alkali cellulose to form alkyl cellulose, and recovering the alkyl cellulose, the improvement which comprises continuously reacting powdered cellulose in an inert organic liquid with an aqueous-alcoholic alkali metal hydroxide solution at temperatures of from about 20° to 80° C. to form alkali cellulose; continuously removing oxygen from the alkali cellulose reaction mixture and reducing the water content to from about 2.5 to 6.0 moles per anhydroglucose unit; and reacting the reaction mixture with at least a stoichiometric amount, but not more than with a molar excess of up to about 50%, based on the alkali metal hydroxide, of an alkylating agent in an inert liquid boiling at a temperature of from about 80° to 160° C., the reaction being carried out continuously in a stirred cascade reactor with 2 to 10 units.
Claim 12
Dependent Claim
151 words
In the method for the preparation of alkyl cellulose by alkalizing cellulose to form alkali cellulose, alkylating the alkali cellulose to form alkyl cellulose, and recovering the alkyl cellulose, the improvement which comprises continuously reacting powdered cellulose in an inert organic liquid with an aqueous-alcoholic alkali metal hydroxide solution at temperatures of from about 20° to 80° C. to form alkali cellulose; continuously removing oxygen from the alkali cellulose reaction mixture and reducing the water content to from about 2.5 to 6.0 moles per anhydroglucose unit; and reacting the reaction mixture with at least a stoichiometric amount, but not more than with a molar excess of up to about 50%, based on the alkali metal hydroxide, of an alkylating agent in an inert liquid boiling at a temperature of from about 80° to 160° C., the reaction being carried out continuously in a stirred cascade reactor with 2 to 10 units.
Claim 13
Dependent Claim
21 words
The method of claim 4, wherein the powdered cellulose has a degree of polymerization value of from about 600 to 1600.
References Cited (Backward Citations)
BE458977A
Cited
CA496725A
Cited
US1683682A
Cited
GB200816A
Cited
GB250617A
Cited
GB526061A
Cited
GB546647A
Cited
US2296829A
Cited
GB625962A
Cited
US2619483A
Cited
US2977355A
Cited
DE1060374B
Cited
US3255071A
Cited
SU385453A3
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-12 | 1986-01-11 | 1986-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-12 | 1990-01-11 | 1990-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-12 | 1994-01-11 | 1994-07-13 | $7700.00 | Window Closed / Lapsed |