US5066560A
Expired / Lapsed
US
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Process for producing toner for electrophotography
Assignee: Resonac Corp
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Filing: 1990-09-07
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Granted: 1991-11-19
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Expires: 2010-09-07
Abstract
Abstract A toner for electrophotography produced by polymerizing a monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder, followed by coagulation is excellent in properties, particularly in cleaning properties, charge stability and caking resistance.
Inventors
- 👤 Ryoji Tan
- 👤 Shigeyoshi Tanaka
- 👤 Ken-ichi Kishi
- 👤 Yasuyuki Iguchi
- 👤 Takeo Kudo
- 👤 Takashi Amano
- 👤 Hideki Kohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:50
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0802; G03G9/0804; G03G9/0806
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
79 words
A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid by adding a coagulating agent and at a temperature now lower than the glass transition point of the principal resin component so that the particles in the liquid after coagulation have diameters suitable as a toner.
Claim 2
Dependent Claim
79 words
A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid by adding a coagulating agent and at a temperature now lower than the glass transition point of the principal resin component so that the particles in the liquid after coagulation have diameters suitable as a toner.
Claim 3
Dependent Claim
32 words
A process according to claim 1, wherein the coagulation is conducted at a temperature not lower than the glass transition point of the principal resin component and not higher than 150° C.
Claim 4
Dependent Claim
29 words
A process according to claim 1, wherein the coagulation is conducted at a temperature 25° to 60° C. higher than the glass transition point of the principal resin component.
Claim 5
Dependent Claim
33 words
A process according to claim 1, wherein the coagulating agent is added in the coagulation in an amount of 0.1 to 5 times the weight of the emulsifier present in the polymerization liquid.
Claim 6
Dependent Claim
26 words
A process according to claim 4, wherein the addition of the coagulating agent is conducted by the addition of a aqueous solution of the coagulating agent.
Claim 7
Dependent Claim
31 words
A process according to claim 4, wherein the coagulating agent is at least one compound selected from the group consisting of inorganic acids, organic acids and water soluble metal salts thereof.
Claim 8
Dependent Claim
24 words
A process according to claim 1, wherein the polymerization initiator used in the polymerization is an oil soluble initiator and/or a water soluble initiator.
Claim 9
Dependent Claim
41 words
A process according to claim 7, wherein the polymerization initiator is an oil soluble one or a combination of an oil soluble one and a water soluble one which is smaller in amount than the weight of the oil soluble one.
Claim 10
Dependent Claim
21 words
A process according to claim 1, wherein the dispersion by emulsification is conducted by means of a high-speed shear dispersing machine.
Claim 11
Dependent Claim
24 words
A process according to claim 1, wherein the polymerizable monomer comprises 40 to 100% by weight of styrene or one or more derivatives thereof.
Claim 12
Dependent Claim
33 words
A process according to claim 1, wherein a liquid dispersion of an offset prevention agent is added to the polymerization liquid at the time when the conversion is 90% by weight or higher.
Claim 13
Dependent Claim
29 words
A process according to claim 1, wherein a liquid dispersion of an offset prevention agent is added to and mixed with the polymerization liquid before or after the coagulation.
Claim 14
Dependent Claim
18 words
A process according to claim 11, wherein the offset prevention agent is a low molecular weight olefin polymer.
Claim 15
Dependent Claim
36 words
A process according to claim 11, wherein a liquid dispersion of the offset prevention agent is added so as to give a content of the agent in the toner obtained of 0.1 to 30% by weight.
Claim 16
Dependent Claim
17 words
A process according to claim 1, wherein the particles after the coagulation are washed with warm water.
Claim 17
Dependent Claim
18 words
A process according to claim 15, wherein the temperature of the warm water is 40° to 100° C.
Claim 18
Dependent Claim
18 words
A process according to claim 15, wherein the temperature of the warm water is 40° to 60° C.
Claim 19
Dependent Claim
11 words
A toner for electrophotography produced by the process of claim 1.
Claim 20
Dependent Claim
11 words
A toner for electrophotography produced by the process of claim 11.
Claim 21
Dependent Claim
61 words
A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid in such a way that the particles in the liquid after coagulation have diameters suitable as a toner.
Claim 22
Dependent Claim
61 words
A process for producing a toner for electrophotography which comprises polymerizing a polymerizable monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder to prepare a principal resin component, and then effecting the coagulation of the resulting polymerization liquid in such a way that the particles in the liquid after coagulation have diameters suitable as a toner.
Claim 23
Dependent Claim
16 words
A process according to claim 20, wherein a coagulating agent is added in the coagulation step.
References Cited (Backward Citations)
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Cited
US3391082A
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GB1404061A
Cited
GB2070029A
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US4514487A
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US4473628A
Cited
US4983488A
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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) | 1994-11-18 | 1995-05-20 | 1995-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-18 | 1999-05-20 | 1999-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-18 | 2003-05-20 | 2003-11-19 | $7700.00 | Window Closed / Lapsed |