Patent US4533616A successfully refreshed from Google Patents.
US4533616A
Expired / Lapsed
US
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Developer for electrophotography of toner and microencapsulated additive
Assignee: Canon Inc
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Filing: 1983-05-25
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Granted: 1985-08-06
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Expires: 2003-05-25
Abstract
Abstract Excellent durability is obtained by use of a developer for electrophotography containing toner and microcapsule type additive.
Inventors
- 👤 Ichiro Ohsaki
- 👤 Tetsuo Hasegawa
- 👤 Koushi Suematsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:14
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; G; G03; G03G; G03G9/00; G03G9/08; G03G9/093; G03G9/09307; G03G9/09335; G03G9/09342; G03G9/097
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
53 words
A developer for electrophotography which comprises a toner and a microencapsulated additive capable of gradual release into said developer during electrophotographic development by destruction of the microcapsule wall, said additive enhancing development of an electrostatic image and comprising a flowability improver, a charge control agent, an electroconductivizing agent, an abrasive or a lubricant.
Claim 2
Dependent Claim
53 words
A developer for electrophotography which comprises a toner and a microencapsulated additive capable of gradual release into said developer during electrophotographic development by destruction of the microcapsule wall, said additive enhancing development of an electrostatic image and comprising a flowability improver, a charge control agent, an electroconductivizing agent, an abrasive or a lubricant.
Claim 3
Dependent Claim
35 words
A developer for electrophotography according to claim 1, wherein said microencapsulated additive is a microcapsule particle of colloidal silica having a core of colloidal silica and a wall of a high polymer surrounding said core.
Claim 4
Dependent Claim
98 words
A developer for electrophotography according to claim 1, wherein said microencapsulated additive is a microcapsule particle obtained by dispersing colloidal silica into a hydrophobic organic solvent having dissolved any one or any combination of polybasic acid halides, bishalo-formates and polyisocyanates to prepare a slurry-in-liquid, dispersing the slurry-in-liquid into water to form oil droplets therein, permitting any or any combination of polyamines, glycols and polyhydric phenols to be dissolved in water, thereby causing interfacial polymerization to occur at the oil-water interface to form microcapsules of the slurry-in-liquid of colloidal silica, and then removing the hydrophobic organic solvent included therein.
Claim 5
Dependent Claim
27 words
A developer for electrophotography according to claim 1, wherein said microencapsulated additive is added in an amount of 0.05 to 10 wt. % based on the toner.
Claim 6
Dependent Claim
23 words
A developer for electrophotography according to claim 2, wherein said colloidal silica has an average primary particle size of 5 to 100 mμ.
Claim 7
Dependent Claim
55 words
An electrophotographic method for visualizing an electrostatic latent image by use of a developer containing a toner and an additive, which comprises using a microencapsulated additive capable of gradual release into the developer during the developing operation, said additive comprising a flowability improver, a charge controlling agent, an electroconductivizing agent, an abrasive or a lubricant.
Claim 8
Dependent Claim
55 words
An electrophotographic method for visualizing an electrostatic latent image by use of a developer containing a toner and an additive, which comprises using a microencapsulated additive capable of gradual release into the developer during the developing operation, said additive comprising a flowability improver, a charge controlling agent, an electroconductivizing agent, an abrasive or a lubricant.
Claim 9
Dependent Claim
16 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive includes a flowability improver therein.
Claim 10
Dependent Claim
34 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive is a microcapsule particle of colloidal silica having a core of colloidal silica and a wall of a high polymer surrounding said core.
Claim 11
Dependent Claim
97 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive is a microcapsule particle obtained by dispersing colloidal silica into a hydrophobic organic solvent having dissolved any one or any combination of polybasic acid halides, bishalo-formates and polyisocyanates to prepare a slurry-in-liquid, dispersing the slurry-in-liquid into water to form oil droplets therein, permitting any or any combination of polyamines, glycols and polyhydric phenols to be dissolved in water, thereby causing interfacial polymerization to occur at the oil-water interface to form microcapsules of the slurry-in-liquid of colloidal silica, and then removing the hydrophobic organic solvent included therein.
Claim 12
Dependent Claim
26 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive is added in an amount of 0.05 to 10 wt. % based on the toner.
Claim 13
Dependent Claim
17 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive includes a charging controlling agent therein.
Claim 14
Dependent Claim
15 words
An electrophotographic method according to claim 6, wherein said microencapsulated additive includes an electroconductivizing agent.
Claim 15
Dependent Claim
22 words
An electrophotographic method according to claim 8, wherein said colloidal silica has an average primary particle size of 5 to 100 mμ.
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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) | 1988-08-05 | 1989-02-04 | 1989-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-05 | 1993-02-04 | 1993-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-05 | 1997-02-04 | 1997-08-06 | $7700.00 | Window Closed / Lapsed |