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US4584254A
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Silicone resin coated carrier particles for use in a two-component dry-type developer
Assignee: Ricoh Co Ltd
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Filing: 1985-03-26
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Granted: 1986-04-22
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Expires: 2005-03-26
Abstract
Abstract Carrier particles for use in a two-component dry-type developer for developing latent electrostatic images are disclosed, which core particle comprises a core particle and a silicone resin layer coated on the core particles, and the silicone resin layer contains an organic tin compound, which serves as a catalyst for hardening the silicone resin layer in the course of the formation of the silicone resin layer on the core particle under application of heat thereto, with a concentration gradient in the direction of the thickness of the silicone resin layer towards the outer surface of the carrier particles.
Inventors
- 👤 Nobuhiro Nakayama
- 👤 Tetsuo Isoda
- 👤 Yoichiro Watanabe
- 👤 Mitsuo Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:23
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1135; G03G9/1136; G03G9/1131; G03G9/1137; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
In carrier particles for use in a two-component dry-type developer for developing latent electrostatic images, the improvement wherein the core particle comprises a core particle and a silicone resin layer coated on said core particle, said silicone resin layer containing an organic tin compound, which serves as a catalyst for hardening said silicone resin layer in the course of the formation of said silicone resin layer on said core particle under application of heat thereto, with a concentration gradient in the direction of the thickness of said silicone resin layer towards the outer surface of said carrier particles.
Claim 2
Dependent Claim
98 words
In carrier particles for use in a two-component dry-type developer for developing latent electrostatic images, the improvement wherein the core particle comprises a core particle and a silicone resin layer coated on said core particle, said silicone resin layer containing an organic tin compound, which serves as a catalyst for hardening said silicone resin layer in the course of the formation of said silicone resin layer on said core particle under application of heat thereto, with a concentration gradient in the direction of the thickness of said silicone resin layer towards the outer surface of said carrier particles.
Claim 3
Dependent Claim
41 words
Carrier particles as claimed in claim 1, wherein said organic tin compound is represented by the formula of R 1 Sn(OCOR 2 ) 2 wherein R 1 and R 2 each represent an alkyl group having 1 to 12 carbon atoms.
Claim 4
Dependent Claim
20 words
Carrier particles as claimed in claim 1, wherein said organic tin compound is selected from the group consisting of: ##STR5##
Claim 5
Dependent Claim
40 words
Carrier particles as claimed in claim 1, wherein the concentration gradient of said organic tin compound in the direction of the thickness of said silicone resin layer is in the range of from 0.01 wt. %/μm to 1.0 wt. %/μm.
Claim 6
Dependent Claim
42 words
Carrier particles as claimed in claim 1, wherein the amount of said organic tin compound in said silicone resin layer is in the range of from 0.1 wt. % to 5 wt. % of the solid components of said silicone resin layer.
Claim 7
Dependent Claim
26 words
Carrier particles as claimed in claim 1, wherein the particle size of said core particle is in the range of from 30 μm to 700 μm.
Claim 8
Dependent Claim
26 words
Carrier particles as claimed in claim 1, wherein the thickness of said silicone resin layer is in the range of from 0.1 μm to 10 μm.
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) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |