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US4680245A
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Electrophotographic positively chargeable developer containing silica treated with a nitrogen containing silane coupling agent and method of developing
Assignee: Canon Inc
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Filing: 1986-11-12
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Granted: 1987-07-14
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Expires: 2006-11-12
Abstract
Abstract An electrostatic image is developed by disposing an electrostatic image bearing member which holds an electrostatic image on its surface and a developer carrying member which carries an insulating developer on its surface with a certain gap provided therebetween, at a developing section bringing an insulating developer containing a nitrogen-containing compound to a thickness thinner than the gap on the developer carrying member and transferring said developer onto the above electrostatic image bearing member at the developing section. The nitrogen-containing compound has nitrogen in the form of a heterocyclic ring and imparts stable positive chargeability to the developer.
Inventors
- 👤 Koshi Suematsu
- 👤 Eiichi Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:54
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/09733; G03G9/09758; G03G13/00; G03G13/06; G03G13/08; G03G9/09; G03G9/0906; G03G9/0918; G03G9/09708; G03G9/09716; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
186 words
A dry developing method, which comprises: (a) disposing an electrostatic image bearing member having an electrostatic image on its surface and a developer carrying member having a surface for carrying an insulating dry developer thereon with a gap between said electrostatic image bearing member and said developer carrying member; and (b) coating said insulating dry developer on said developer carrying member, wherein said insulating dry developer is positively chargeable and comprises toner particles containing a binder resin and a colorant or a magnetic powder, and fine silica particles treated with a nitrogen-containing silane coupling agent represented by the formula: R.sub.m SiY.sub.n wherein R is an alkoxy group or chlorine, m is an integer of from 1 to 3, Y is an unsaturated nitrogen-containing heterocyclic group or derivative thereof, and n is an integer of from 1 to 3, wherein m+n is 4; and (c) bringing the coated insulating developer to said gap, wherein the insulating developer on said developer carrying member surface at said gap has a thickness thinner than said gap and causing the insulating developer to jump to the electrostatic image to effect development.
Claim 2
Dependent Claim
186 words
A dry developing method, which comprises: (a) disposing an electrostatic image bearing member having an electrostatic image on its surface and a developer carrying member having a surface for carrying an insulating dry developer thereon with a gap between said electrostatic image bearing member and said developer carrying member; and (b) coating said insulating dry developer on said developer carrying member, wherein said insulating dry developer is positively chargeable and comprises toner particles containing a binder resin and a colorant or a magnetic powder, and fine silica particles treated with a nitrogen-containing silane coupling agent represented by the formula: R.sub.m SiY.sub.n wherein R is an alkoxy group or chlorine, m is an integer of from 1 to 3, Y is an unsaturated nitrogen-containing heterocyclic group or derivative thereof, and n is an integer of from 1 to 3, wherein m+n is 4; and (c) bringing the coated insulating developer to said gap, wherein the insulating developer on said developer carrying member surface at said gap has a thickness thinner than said gap and causing the insulating developer to jump to the electrostatic image to effect development.
Claim 3
Dependent Claim
14 words
A developing method according to claim 1, wherein said insulating developer contains carrier particles.
Claim 4
Dependent Claim
21 words
A developing method according to claim 1, wherein said unsaturated nitrogen-containing heterocyclic group is selected from the group consisting of: ##STR23##
Claim 5
Dependent Claim
32 words
A developing method according to claim 1, wherein said insulating developer has a saturation magnetization of 10 emu/g or less at an external magnetic field of 5000 Oersted and is substantially non-magnetic.
Claim 6
Dependent Claim
12 words
A developing method according to claim 1, wherein the developer is magnetic.
Claim 7
Dependent Claim
80 words
An insulating, positively chargeable dry developer comprising (i) toner particles containing a binder resin and a colorant or a magnetic powder and (ii) fine silica particles treated with a nitrogen-containing silane coupling agent represented by the formula: R.sub.m SiY.sub.n wherein R is an alkoxy group or chlorine, m is an integer of from 1 to 3, Y is an unsaturated nitrogen-containing heterocyclic group or derivative thereof and n is an integer of from 1 to 3, wherein m+n is 4.
Claim 8
Dependent Claim
80 words
An insulating, positively chargeable dry developer comprising (i) toner particles containing a binder resin and a colorant or a magnetic powder and (ii) fine silica particles treated with a nitrogen-containing silane coupling agent represented by the formula: R.sub.m SiY.sub.n wherein R is an alkoxy group or chlorine, m is an integer of from 1 to 3, Y is an unsaturated nitrogen-containing heterocyclic group or derivative thereof and n is an integer of from 1 to 3, wherein m+n is 4.
Claim 9
Dependent Claim
20 words
A developer according to claim 6, wherein said unsaturated nitrogen-containing heterocyclic group is selected from the group consisting of: ##STR24##
Claim 10
Dependent Claim
12 words
A developer according to claim 6, wherein the developer contains carrier particles.
Claim 11
Dependent Claim
22 words
A developer according to claim 6, wherein said silica particles are fumed silica particles resulting from vapor phase oxidation of silicon halide.
Claim 12
Dependent Claim
29 words
A developing method according to claim 1, wherein the toner particles have 0.01 to 3% by weight of the fine silica particles treated with the nitrogen-containing silane coupling agent.
Claim 13
Dependent Claim
28 words
A developer according to claim 6, wherein the toner particles have 0.01 to 3% by weight of the fine silica particles treated with the nitrogen-containing silane coupling agent.
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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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |