Patent US4863972A successfully refreshed from Google Patents.
US4863972A
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US
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Porous cross-linked polyvinyl alcohol particles, process for producing the same, and separating agent composed of the same
Assignee: Mitsubishi Chemical Corp
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Filing: 1987-07-07
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Granted: 1989-09-05
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Expires: 2007-07-07
Abstract
Abstract Porous cross-linked polyvinyl alcohol particles which is used for a chromatographic medium is prepared by: dispersing an aqueous solution of a mixture of polyvinyl alcohol and a salt in an organic solvent; allowing a gel to form spontaneously from the dispersion; and reacting the gel with a cross-linking agent.
Inventors
- 👤 Takaharu Itagaki
- 👤 Hiroshi Kusano
- 👤 Eiji Miyata
- 👤 Takayuki Tashiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:07
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08J9/283; B; B01; B01D; B01D15/00; B01D15/08; B01D15/26; B01D15/34; B01J; B01J20/00; B01J20/22; B01J20/26; B01J20/261; B01J20/265; B01J20/267; C08J3/00; C08J3/12; C08J3/16; B01D15/32; B01D15/325; B01D15/327; B01D15/36; B01D15/361; B01D15/38; B01D15/3804; C08J2329/00; C08J2329/02; C08J2329/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
Porous cross-linked polyvinyl alcohol particles prepared by; dispersing an aqueous solution of a mixture of polyvinyl alcohol and a salt in an organic solvent to spontaneously form a porous and water-insoluble gel in the absence of a cross-linking agent; and reacting said gel with a cross-linking agent.
Claim 2
Dependent Claim
47 words
Porous cross-linked polyvinyl alcohol particles prepared by; dispersing an aqueous solution of a mixture of polyvinyl alcohol and a salt in an organic solvent to spontaneously form a porous and water-insoluble gel in the absence of a cross-linking agent; and reacting said gel with a cross-linking agent.
Claim 3
Dependent Claim
17 words
Porous cross-linked polyvinyl alcohol particles according to claim 1, wherein the cross-linking agent is a dialdehyde compound.
Claim 4
Dependent Claim
26 words
Porous cross-linked polyvinyl alcohol particles according to claim 1, wherein the reaction with a cross-linking agent is carried out in the presence of an acid catalyst.
Claim 5
Dependent Claim
23 words
Porous cross-linked polyvinyl alcohol particles according to claim 1, wherein the reaction with a cross-linking agent is carried out in an aqueous medium.
Claim 6
Dependent Claim
17 words
Porous cross-linked polyvinyl alcohol particles according to claim 1, wherein the organic solvent is a halogenated hydrocarbon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |