US4044198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for cold-milling cellulose derivatives
Assignee: Hoechst AG
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Filing: 1975-03-06
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Granted: 1977-08-23
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Expires: 1995-03-06
Abstract
Abstract This invention relates to an improvement in the method for the cold-milling of a cellulose derivative, in which the cellulose derivative is cooled by means of liquid nitrogen until it becomes brittle and the thus cooled cellulose derivative is milled in a mill, the improvement comprising cold-milling a cellulose derivative which is soluble or swellable in water and has a water content of between 40 and 150 percent by weight, based on its dry weight, and which is, at 20° C, able to absorb, during swelling, more than 150 percent by weight of water, based on its dry weight.
Inventors
- 👤 Michael Kostrzewa
- 👤 Arno Holst
- 👤 Gerhard Buchberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:28
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; B; B29; B29B; B29B13/00; B29B13/10; C08J2301/00; C08J2301/08; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10S; Y10S241/00; Y10S241/37
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
In the method for the cold-milling of a cellulose derivative, in which the cellulose derivative is cooled by means of liquid nitrogen until it becomes brittle and the thus cooled cellulose derivative is milled in a mill, the improvement comprising cold-milling to a milled product having a high proportion of fine grain, a cellulose derivative which is soluble or swellable in water and has a water content of between 40 and 150 per cent by weight, based on its dry weight, and which is, at 20° C, able to absorb, during swelling, more than 150 per cent by weight of water, based on its dry weight.
Claim 2
Dependent Claim
106 words
In the method for the cold-milling of a cellulose derivative, in which the cellulose derivative is cooled by means of liquid nitrogen until it becomes brittle and the thus cooled cellulose derivative is milled in a mill, the improvement comprising cold-milling to a milled product having a high proportion of fine grain, a cellulose derivative which is soluble or swellable in water and has a water content of between 40 and 150 per cent by weight, based on its dry weight, and which is, at 20° C, able to absorb, during swelling, more than 150 per cent by weight of water, based on its dry weight.
Claim 3
Dependent Claim
20 words
A method according to claim 1 in which the cellulose derivative which is cold-milled is a non-ionic water-soluble cellulose ether.
Claim 4
Dependent Claim
21 words
A method according to claim 1 in which the water content of the cold-milled cellulose derivative is reduced by heating it.
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) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |