US5275901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer for electrophotography
Assignee: Minolta Co Ltd
•
Filing: 1992-04-30
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Granted: 1994-01-04
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Expires: 2012-04-30
Abstract
Abstract The present invention relates to a developer for developing electrostatic latent images obtained by mixing toner particles comprising a binder resin and a coloring agent with fine magnetic particles treated by hydrophobic agent.
Inventors
- 👤 Masahiro Anno
- 👤 Eiichi Sano
- 👤 Makoto Kobayashi
- 👤 Junji Machida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:36
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0836; G03G9/0839; G03G9/087; G03G9/08784; G03G9/08795
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
41 words
A developer for developing electrostatic latent images obtained by mixing toner particles which comprises a binder resin and a coloring agent with fine magnetic particles treated by a hydrophobic agent and having a mean particle size of 100 nm or less.
Claim 2
Dependent Claim
41 words
A developer for developing electrostatic latent images obtained by mixing toner particles which comprises a binder resin and a coloring agent with fine magnetic particles treated by a hydrophobic agent and having a mean particle size of 100 nm or less.
Claim 3
Dependent Claim
20 words
The developer of claim 1, wherein the magnetic fine particles have an electrical resistance of 10 6 Ω·cm or more.
Claim 4
Dependent Claim
19 words
The developer of claim 1, wherein the magnetic fine particles have a degree of hydrophobicity of 30% or more.
Claim 5
Dependent Claim
16 words
The developer of claim 1, wherein the magnetic fine particles are treated by a coupling agent.
Claim 6
Dependent Claim
24 words
The developer of claim 1, wherein the amount of the magnetic fine particles is 0.05 to 30 parts-by-weight on the basis of the toner.
Claim 7
Dependent Claim
20 words
The developer of claim 1, wherein the magnetic fine particles have a smallest diameter/largest diameter ratio of 0.7 or more.
Claim 8
Dependent Claim
45 words
A developer for developing electrostatic latent images obtained by mixing toner particles which comprises a binder resin and a coloring agent, with a fluidizing agent and fine magnetic particles treated by a hydrophobic agent and having a mean particle size of 100 nm or less.
Claim 9
Dependent Claim
45 words
A developer for developing electrostatic latent images obtained by mixing toner particles which comprises a binder resin and a coloring agent, with a fluidizing agent and fine magnetic particles treated by a hydrophobic agent and having a mean particle size of 100 nm or less.
Claim 10
Dependent Claim
36 words
The developer of claim 1, wherein the binder resin has a relationship between the number average molecular weight (Mn), weight average molecular weight (Mw) and Z average molecular weight (Mz) as shown below: 1,000≦Mn≦7,000 40≦Mw/Mn≦70 2,000≦Mz/Mn≦7,000.
Claim 11
Dependent Claim
19 words
The developer of claim 7, wherein the magnetic fine particles have a degree of hydrophobicity of 30% or more.
Claim 12
Dependent Claim
24 words
The developer of claim 7, wherein the amount of the magnetic fine particles is 0.05 to 30 parts-by-weight on the basis of the toner.
Claim 13
Dependent Claim
23 words
The developer of claim 7, wherein the amount of the fluidizing agents is 0.05 to 1.0 part-by-weight on the basis of the toner.
Claim 14
Dependent Claim
15 words
The developer of claim 11, wherein the fluidizing agents are treated by a hydrophobic agent.
Claim 15
Dependent Claim
15 words
The developer of claim 4, wherein the coupling agent comprises a long chain alkyl group.
References Cited (Backward Citations)
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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) | 1997-01-03 | 1997-07-05 | 1998-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-03 | 2001-07-05 | 2002-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-03 | 2005-07-05 | 2006-01-04 | $7700.00 | Window Closed / Lapsed |