Patent US4461892A successfully refreshed from Google Patents.
US4461892A
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US
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Process for preparing porous spherical cellulose particles
Assignee: JNC Corp
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Filing: 1983-02-23
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Granted: 1984-07-24
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Expires: 2003-02-23
Abstract
Abstract A process for preparing porous, spherical cellulose particles which comprises suspending a cellulose organic ester solution dissolved in a chlorinated hydrocarbon solvent into an aqueous medium to form droplets of the solution, evaporating the chlorinated hydrocarbon solvent in the droplets to form cellulose organic ester spherical particles, and saponifying the cellulose organic ester spherical particles. In the aforesaid process, an acid or alkaki is added and mixed with the cellulose organic ester solution prior to suspending the cellulose organic ester solution into the aqueous medium to control the porosity of the porous, spherical cellulose particles with high reproducibility.
Inventors
- 👤 Masahiko Nishikawa
- 👤 Hiroaki Ishibashi
- 👤 Hidenori Furukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:18
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; C08B; C08B3/00; C08B3/22; C08B3/24; C08J9/00; C08J9/28; C08J2201/00; C08J2201/04; C08J2201/05; C08J2201/0502; C08J2301/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
131 words
Porous, spherical cellulose particles with high reproducibility, produced by dissolving a cellulose organic ester in a solvent consisting essentially of a chlorinated hydrocarbon, adding 0.001-20 wt.% (based on said cellulose organic ester) of an acid or alkali to the dissolved cellulose organic ester solution, mixing the resultant solution at a temperature from 0° to 45° C. for a period of time from 0.2 to 30 hours, suspending said cellulose organic ester solution in an aqueous medium to thereby form droplets, removing said solvent by evaporation to form cellulose organic ester particles, and saponifying said cellulose particles, the excluded critical molecular weight and the degree of porosity of the porous, spherical cellulose particles being capable of being varied as desired by varying the amount of the acid or alkali to be added.
Claim 2
Dependent Claim
131 words
Porous, spherical cellulose particles with high reproducibility, produced by dissolving a cellulose organic ester in a solvent consisting essentially of a chlorinated hydrocarbon, adding 0.001-20 wt.% (based on said cellulose organic ester) of an acid or alkali to the dissolved cellulose organic ester solution, mixing the resultant solution at a temperature from 0° to 45° C. for a period of time from 0.2 to 30 hours, suspending said cellulose organic ester solution in an aqueous medium to thereby form droplets, removing said solvent by evaporation to form cellulose organic ester particles, and saponifying said cellulose particles, the excluded critical molecular weight and the degree of porosity of the porous, spherical cellulose particles being capable of being varied as desired by varying the amount of the acid or alkali to be added.
Claim 3
Dependent Claim
45 words
Particles according to claim 1 wherein the concentration of said cellulose organic ester in the solution of cellulose organic ester dissolved in said solvent is in the range of from 1 to 15 parts by weight based on 100 parts by volume of the solvent.
Claim 4
Dependent Claim
27 words
Particles according to claim 1 wherein said solvent consists essentially of at least one chlorinated hydrocarbon selected from dichloromethane, trichloromethane, carbon tetrachloride, trichloroethane, tetrachloroethane, trichloroethylene and tetrachloroethylene.
Claim 5
Dependent Claim
31 words
Particles according to claim 1 wherein said solvent is a mixed solvent containing chlorinated hydrocarbon as the major component and at least one material selected from methanol, ethanol, acetone and nitromethane.
Claim 6
Dependent Claim
10 words
Particles according to claim 1 wherein an acid is added.
Claim 7
Dependent Claim
12 words
Particles according to claim 5 wherein said acid is an inorganic acid.
Claim 8
Dependent Claim
29 words
Particles according to claim 5 wherein said acid is at least one selected from hydrochloric acid, hydrobromic acid, hydrofluoric acid, sulfuric acid, sulfurous acid, phosphoric acid and nitric acid.
Claim 9
Dependent Claim
11 words
Particles according to claim 5 wherein said acid is sulfonic acid.
Claim 10
Dependent Claim
10 words
Particles according to claim 1 wherein an alkali is added.
Claim 11
Dependent Claim
19 words
Particles according to claim 9 wherein said alkali is an alkali metal hydroxide or an alkaline earth metal hydroxide.
Claim 12
Dependent Claim
28 words
Particles according to claim 1 wherein said acid or alkali is added to an amount of from 0.001 to 20% by weight based on said cellulose organic ester.
Claim 13
Dependent Claim
28 words
Particles according to claim 11, wherein said acid or alkali is added in an amount of from 0.05 to 10% by weight based on said cellulose organic ester.
Claim 14
Dependent Claim
32 words
Particles according to claim 1 wherein said acid or alkali is added and mixed with the cellulose organic ester solution after the cellulose organic ester is dissolved in said chlorinated hydrocarbon solvent.
Claim 15
Dependent Claim
55 words
Particles according to claim 12 wherein after dissolving said acid or alkali in the cellulose organic ester solution, the resulting solution is mixed with stirring at a temperature of from 0° to 45° C. for a period of time of from 0.2 to 30 hours, and added to the aqueous medium to be suspended therein.
Claim 16
Dependent Claim
29 words
Particles according to claim 1 wherein said acid or alkali is added and mixed with the solvent before the cellulose organic ester is dissolved in said chlorinated hydrocarbon solvent.
Claim 17
Dependent Claim
144 words
Porous, spherical cellulose particles with high reproducibility, produced by dissolving a cellulose organic ester in a solvent consisting essentially of a chlorinated hydrocarbon, mixing the resultant solution at a temperature from 0° to 45° C. for a period of time of from 0.2 to 30 hours, suspending said cellulose organic ester solution in an aqueous medium to thereby form droplets, removing said solvent by evaporation to form cellulose organic ester particles, and saponifying said cellulose particles, 0.001 to 20 wt% (based on said cellulose organic ester) of an acid or alkali being added to said solvent while the cellulose organic ester is being dissolved or prior to said dissolution, the excluded critical molecular weight and the degree of porosity of the porous, spherical cellulose particles being capable of being varied as desired by varying the amount of the acid or alkali to be added.
Claim 18
Dependent Claim
144 words
Porous, spherical cellulose particles with high reproducibility, produced by dissolving a cellulose organic ester in a solvent consisting essentially of a chlorinated hydrocarbon, mixing the resultant solution at a temperature from 0° to 45° C. for a period of time of from 0.2 to 30 hours, suspending said cellulose organic ester solution in an aqueous medium to thereby form droplets, removing said solvent by evaporation to form cellulose organic ester particles, and saponifying said cellulose particles, 0.001 to 20 wt% (based on said cellulose organic ester) of an acid or alkali being added to said solvent while the cellulose organic ester is being dissolved or prior to said dissolution, the excluded critical molecular weight and the degree of porosity of the porous, spherical cellulose particles being capable of being varied as desired by varying the amount of the acid or alkali to be added.
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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) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |