US4357467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Depolymerized cellulosic material with low crystallinity obtained from cellulosic fibers and process for its manufacture
Assignee: Battelle Memorial Institute Inc
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Filing: 1979-10-23
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Granted: 1982-11-02
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Expires: 1999-10-23
Abstract
Abstract Depolymerized cellulose powder having substantially an amorphous structure which is obtained by letting cellulose fibers dissolve in concentrated hydrochloric acid of about 40% and at a temperature of at least 38° C. A homogeneous acid hydrolysis is carried out under well controlled conditions in order to depolymerize the dissolved cellulose and is stopped when the cellulose has achieved a mean degree of polymerization between 10 and 200. The depolymerized dissolved cellulose is then separated and processed in order to obtain the aforesaid powder of amorphous depolymerized cellulose.
Inventors
- 👤 Jean-Pierre Sachetto
- 👤 Jean-Pierre Michel
- 👤 Sergio Cuccolo
- 👤 Alain Regnault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:32
CPC Classifications
C; C08; C08B; C08B15/00; C08B15/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
57 words
Depolymerized cellulose material having a degree of crystallinity of at least 17% but not exceeding 70%, an average degree of polymerization DP m corresponding to 10 to 200 units of anhydroglucose and being in powdered form with a low moisture content, the particles of the powdered material being microporous and having a globular shape with rounded angles.
Claim 2
Dependent Claim
57 words
Depolymerized cellulose material having a degree of crystallinity of at least 17% but not exceeding 70%, an average degree of polymerization DP m corresponding to 10 to 200 units of anhydroglucose and being in powdered form with a low moisture content, the particles of the powdered material being microporous and having a globular shape with rounded angles.
Claim 3
Dependent Claim
44 words
Material according to claim 1, characterized by the fact that the size of the particles of said powder are of the order of 50 to 100 μm and that at least half of its molecules have a DP equal to the DP m .
Claim 4
Dependent Claim
25 words
Material according to claim 1, characterized by the fact that the density of the powder in the free state is from 0.3 to 0.7 kg/l.
Claim 5
Dependent Claim
20 words
Material according to claim 1, characterized by the fact that it is hydrophilic and compatible with starches, proteins and lipids.
Claim 6
Dependent Claim
79 words
A process for manufacturing the material of claim 1, comprising dissolving cellulosic material in concentrated aqueous hydrochloric acid at a temperature in the range of from 30° to 50° C. and maintaining the solution at this temperature for 15 to 60 minutes whereby the fibres of the material, under these conditions, depolymerize by homogeneous hydrolysis, then interrupting the hydrolysis either by dilution of the reaction medium or by cooling and separating the depolymerized cellulose material from the hydrolyzing solution.
Claim 7
Dependent Claim
41 words
Process according to claim 5, characterized by the fact that the acid is 37-42% aqueous HCl and that interrupting the hydrolysis is effected by diluting the hydrolyzing medium with water, such dilution causing a separation by precipitation of the depolymerized material.
Claim 8
Dependent Claim
38 words
Process according to claim 6, characterized by the fact that this separation is carried out by progressive dilution and fractionated precipitation, the fractions obtained, in turn, having an increasing level of depolymerization and a decreasing level of crystallinity.
Claim 9
Dependent Claim
29 words
Process according to claim 5, characterized by the fact that interrupting the hydrolysis is effected by cooling and the separation is effected by a fast evaporation of the solution.
Claim 10
Dependent Claim
27 words
Process according to claim 8, characterized by the fact that the solution is evaporated by spray drying in a heated air stream between 160° and 80° C.
Claim 11
Dependent Claim
37 words
Process according to claim 6, characterized by the fact that the precipitated product is collected by draining, filtration or centrifugation and that it is dried and ground finely so as to homogenize the dimensions of its particles.
Claim 12
Dependent Claim
22 words
Process according to claim 10, characterized by the fact that there is used for grinding a hammer mill or a ball mill.
Claim 13
Dependent Claim
19 words
The depolymerized cellulose material of any one of claims 1, 2-4 wherein the material is a dietetic foodstuff additive.
Claim 14
Dependent Claim
18 words
The depolymerized cellulose material of any one of claims 1, 2-4 wherein the material is a pharmaceutical excipient.
Claim 15
Dependent Claim
18 words
The depolymerized cellulose material of any one of claims 1, 2-4 wherein the material is a cosmetic excipient.
References Cited (Backward Citations)
DE482727C
Cited
FR748428A
Cited
US2305833A
Cited
US2978446A
Cited
US3278519A
Cited
US3345357A
Cited
US3397198A
Cited
US3954727A
Cited
US4058411A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |