Patent US4312980A successfully refreshed from Google Patents.
US4312980A
Expired / Lapsed
US
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Process for preparing porous cellulose spherical particles
Assignee: JNC Corp
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Filing: 1980-07-30
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Granted: 1982-01-26
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Expires: 2000-07-30
Abstract
Abstract A solution of cellulose triacetate in a mixed solvent consisting essentially of a chlorinated hydrocarbon with a boiling point lower than that of an aqueous medium and an aliphatic higher alcohol with 6 or more than 6 carbon atoms is suspended into the aqueous medium to form droplets of the above-mentioned solution, and then the chlorinated hydrocarbon in the droplets is removed by evaporation to obtain spherical particles of cellulose triacetate containing the aliphatic higher alcohol. The spherical particles thus obtained are saponified and removed of the aliphatic higher alcohol, to prepare porous cellulose spherical particles.
Inventors
- 👤 Yoshiaki Motozato
- 👤 Hiroaki Ishibashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:43
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; B; B01; B01D; B01D15/00; B01D15/08; C08J9/00; C08J9/28; C08L; C08L1/00; C08L1/08; C08L1/10; C08L1/12; B01D15/26; B01D15/34; B01D15/36; B01D15/361; B01D15/38; B01D15/3804; C08J2201/00; C08J2201/04; C08J2201/05; C08J2201/0502; C08J2301/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A process for preparing porous cellulose spherical particles which comprises (a) forming a solution of cellulose triacetate in a mixed solvent that consists essentially of (1) a chlorinated hydrocarbon and (2) an aliphatic higher alcohol with at least six carbon atoms, (b) suspending said solution in an aqueous medium to thereby form a plurality of droplets of said solution in said medium, said aqueous medium having a boiling point higher than said chlorinated hydrocarbon, (c) removing the chlorinated hydrocarbon from said droplets by evaporation, and (d) subjecting the thus obtained spherical particles of cellulose triacetate containing said aliphatic higher alcohol to saponification in order to remove said aliphatic higher alcohol from the spherical particles.
Claim 2
Dependent Claim
114 words
A process for preparing porous cellulose spherical particles which comprises (a) forming a solution of cellulose triacetate in a mixed solvent that consists essentially of (1) a chlorinated hydrocarbon and (2) an aliphatic higher alcohol with at least six carbon atoms, (b) suspending said solution in an aqueous medium to thereby form a plurality of droplets of said solution in said medium, said aqueous medium having a boiling point higher than said chlorinated hydrocarbon, (c) removing the chlorinated hydrocarbon from said droplets by evaporation, and (d) subjecting the thus obtained spherical particles of cellulose triacetate containing said aliphatic higher alcohol to saponification in order to remove said aliphatic higher alcohol from the spherical particles.
Claim 3
Dependent Claim
17 words
The process according to claim 1 wherein said aliphatic alcohol has from 6 to 18 carbon atoms.
Claim 4
Dependent Claim
17 words
The process according to claim 1 when said aliphatic alcohol has from 6 to 12 carbon atoms.
Claim 5
Dependent Claim
26 words
The process according to claim 1 wherein from 0.1 to 15 times by weight of the aliphatic higher alcohol based on the cellulose triacetate is used.
Claim 6
Dependent Claim
28 words
The process according to claim 1 characterized in that from 0.3 to 7 times by weight of the aliphatic higher alcohol based on the cellulose triacetate is used.
Claim 7
Dependent Claim
35 words
The process according to claim 1 characterized in that the content of cellulose triacetate in said solution is from 0.1 to 15% based on the total amount of the chlorinated hydrocarbon and the cellulose triacetate.
Claim 8
Dependent Claim
37 words
The process according to claim 1 characterized in that the temperature for evaporating and removing chlorinated hydrocarbon from said droplets is between the freezing point of said aqueous medium and the boiling point of said chlorinated hydrocarbon.
Claim 9
Dependent Claim
17 words
The process according to claim 7, characterized in that said evaporating temperature is at least 15° C.
Claim 10
Dependent Claim
28 words
The process according to claim 7 or 8 characterized in that said evaporating temperature is at least 2° C. lower than the boiling point of the chlorinated hydrocarbon.
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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) | 1985-01-25 | 1985-07-27 | 1986-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-25 | 1989-07-27 | 1990-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-25 | 1993-07-27 | 1994-01-26 | $7700.00 | Window Closed / Lapsed |