US4055510A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing of spherical cellulose particles
Assignee: Czech Academy of Sciences
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Filing: 1975-05-21
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Granted: 1977-10-25
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Expires: 1995-05-21
Abstract
Abstract The invention relates to a method for manufacturing of spherical cellulose particles in bead form which enables to control the partial shape and porosity of the particles. Resulting cellulose sorbents are suitable carriers and materials for chromatography. The invented methods consists in heating a viscose (an aqueous solution of sodium cellulose xanthate) suspension in a water-immiscible liquid to 30°-100° C under stirring to form spherical droplets and solidify them and in the subsequent acidic decomposition of the solid xanthate globules either directly by addition of an acid soluble in the dispersion medium, or additionally after isolation and eventual washing of the particles to achieve the required wet volume. Liquids with the viscosity up to 100 cSt are advantageously used as dispersion medium and surfactants and/or modifying reagents (e.g. epichlorohydrine) may be added to the suspension.
Inventors
- 👤 Jan Peska
- 👤 Jiri Stamberg
- 👤 Zdenko Blace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:15
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; B; B01; B01J; B01J13/00; B01J13/0052; B01J13/0065; B01J2/00; C08K; C08K5/00; C08K5/0008; C08K5/0025; C08K5/04; C08K5/15; C08J2301/00; C08J2301/08; C08J2301/22; C08J2301/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
84 words
A method of producing spherical cellulose particles, which consists of the sequence of steps of providing a dispersion of viscose droplets in a water-immiscible liquid, heating such dispersion at a temperature of at least 30° to 100° C. with continuous agitation under stationary hydrodynamic conditions for a time sufficient to partially regenerate the cellulose in the viscose and to thereby, and solely as a result of said heating, solidify the viscose droplets into shape-stable particles, and thereafter completing the regeneration of the cellulose in
Claim 2
Independent Claim
84 words
A method of producing spherical cellulose particles, which consists of the sequence of steps of providing a dispersion of viscose droplets in a water-immiscible liquid, heating such dispersion at a temperature of at least 30° to 100° C. with continuous agitation under stationary hydrodynamic conditions for a time sufficient to partially regenerate the cellulose in the viscose and to thereby, and solely as a result of said heating, solidify the viscose droplets into shape-stable particles, and thereafter completing the regeneration of the cellulose in
Claim 3
Dependent Claim
12 words
A method according to claim 1, in which the water-immiscible liquid has
Claim 4
Dependent Claim
11 words
A method according to claim 2, in which the water-immiscible liquid
Claim 5
Dependent Claim
11 words
A method according to claim 2, in which the water-immiscible liquid
Claim 6
Dependent Claim
11 words
A method according to claim 2, in which the water-immiscible liquid
Claim 7
Dependent Claim
13 words
A method according to claim 1, in which the acid comprises acetic acid.
Claim 8
Dependent Claim
12 words
A method according to claim 1, in which the acid comprises sulfuric
Claim 9
Dependent Claim
22 words
A method according to claim 1, in which the acid regeneration of the heat-solidified particles is effected directly in the dispersion medium.
Claim 10
Dependent Claim
22 words
A method according to claim 1, in which the heat-solidified particles are separated from the dispersion medium, and such separated particles are
Claim 11
Dependent Claim
12 words
A method according to claim 9, in which the separated particles are
Claim 12
Dependent Claim
12 words
A method according to claim 10, in which the organic solvent comprises
Claim 13
Dependent Claim
12 words
A method according to claim 1, in which the dispersion includes a
Claim 14
Dependent Claim
11 words
A method according to claim 12, in which the surface-active agent
Claim 15
Dependent Claim
15 words
A method according to claim 1, in which the heating is effected at 90° C.
References Cited (Backward Citations)
US3179587A
Cited
US3562289A
Cited
US3597350A
Cited
US3737337A
Cited
US3671463A
Cited
US3864327A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |