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US4885350A
Expired / Lapsed
US
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Method of producing polymer particles having narrow particle size distribution
Assignee: Ricoh Co Ltd
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Filing: 1987-08-24
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Granted: 1989-12-05
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Expires: 2007-08-24
Abstract
Abstract A method of producing polymer particles having a particle size distribution of ±25% with respect to each average particle size in an amount of 95 wt. % or more, within the average particle sizes ranging from 1 μm to 100 μm, is disclosed, which comprises the steps of: (1) adding a polymer dispersion stabilizer in an amount of 0.1 to 10 wt. % to a hydrophilic organic liquid in which the polymeric dispersion stabilizer is soluble; (2) adding thereto at least one vinyl monomer in an amount of not more than 50 times by weight the amount of the polymeric dispersion stabilizer, which monomer is soluble in the hydrophilic organic liquid, but a polymer synthesized from the monomer being swelled or substantially insoluble in the hydrophilic organic liquid; and (3) polymerizing the monomer under the condition that the amount of the vinyl monomer is 200 wt. % or less of the hydrophilic organic liquid.
Inventors
- 👤 Hiroshi Yamashita
- 👤 Kenkichi Muto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:03
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/04; C08F2/06; C08F2/08; Y; Y10; Y10S; Y10S526/00; Y10S526/909
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
232 words
A method of producing polymer particles having a particle size distribution of ±25% with respect to each average particle size in an amount of 95 wt. % or more, within the average particle sizes ranging from 1 μm to 100 μm, comprising the steps of: (1) adding polymeric dispersion stabilizer in an amount of 0.1 to 10 wt. % to a hydrophilic organic liquid in which said polymeric dispersion stabilizer is soluble; (2) adding thereto at least one vinyl monomer in an amount of said polymeric dispersion stabilizer so that a minimum amount of at least 5 wt. % of said polymeric dispersion stabilizer relative to the amount of vinyl monomer is present, which monomer is soluble in said hydrophilic organic liquid, but when polymerized, said polymer is swellable or is substantially insoluble in said hydrophilic organic liquid wherein said polymeric dispersion stabilizer is selected from the group consisting of homopolymers and copolymers of vinylpyridine, vinylpyrrolidone, N-vinylimidazole and ethyleneimine; and (3) polymerizing said monomer under the condition that the amount of said vinyl monomer is 200 wt. % or less of said hydrophilic organic liquid, wherein said hydrophilic organic liquid is selected from the group consisting of methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl alcohol benzyl alcohol, cyclohexanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, glycerol and diethylene glycol.
Claim 2
Independent Claim
232 words
A method of producing polymer particles having a particle size distribution of ±25% with respect to each average particle size in an amount of 95 wt. % or more, within the average particle sizes ranging from 1 μm to 100 μm, comprising the steps of: (1) adding polymeric dispersion stabilizer in an amount of 0.1 to 10 wt. % to a hydrophilic organic liquid in which said polymeric dispersion stabilizer is soluble; (2) adding thereto at least one vinyl monomer in an amount of said polymeric dispersion stabilizer so that a minimum amount of at least 5 wt. % of said polymeric dispersion stabilizer relative to the amount of vinyl monomer is present, which monomer is soluble in said hydrophilic organic liquid, but when polymerized, said polymer is swellable or is substantially insoluble in said hydrophilic organic liquid wherein said polymeric dispersion stabilizer is selected from the group consisting of homopolymers and copolymers of vinylpyridine, vinylpyrrolidone, N-vinylimidazole and ethyleneimine; and (3) polymerizing said monomer under the condition that the amount of said vinyl monomer is 200 wt. % or less of said hydrophilic organic liquid, wherein said hydrophilic organic liquid is selected from the group consisting of methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl alcohol benzyl alcohol, cyclohexanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, glycerol and diethylene glycol.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-12-04 | 1993-06-05 | 1993-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-04 | 1997-06-05 | 1997-12-05 | $3760.00 | Window Closed / Lapsed |
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