US4868082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Binder type carrier
Assignee: Minolta Co Ltd
•
Filing: 1988-01-27
•
Granted: 1989-09-19
•
Expires: 2008-01-27
Abstract
Abstract The present invention relates binder type carriers, the surface of which is firmly adhered with charge controlling agents, by which the elastic charge of the carriers can be controlled to a desirable polarity and a level without the influence of the chargeability inherent to the magnetic powders themselves.
Inventors
- 👤 Toshitaro Kohri
- 👤 Junji Machida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:34
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1138; G03G9/107; G03G9/1088; G03G9/10882
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
40 words
A binder type carrier comprising: a core which comprises thermoplastic resin, magnetic powder, and particles of charge controlling agents adhered on the surface of said core; said binder type carrier having a particle size of from 50 to 70 microns.
Claim 2
Dependent Claim
40 words
A binder type carrier comprising: a core which comprises thermoplastic resin, magnetic powder, and particles of charge controlling agents adhered on the surface of said core; said binder type carrier having a particle size of from 50 to 70 microns.
Claim 3
Dependent Claim
31 words
A binder type carrier of the claim 1, in which the thermoplastic resin in a member selected from the group consisting of copolymers of acrylic monomers and styrene, and polyester resins.
Claim 4
Dependent Claim
23 words
A binder type carrier of the claim 1, in which the core is formed by dispersing said magnetic powder in said thermoplastic resin.
Claim 5
Dependent Claim
24 words
A binder type carrier of the claim 1, in which the particle size of the charge controlling agent is from 0.02 to 15 microns.
Claim 6
Dependent Claim
38 words
A binder type carrier of the claim 1, in which the amount of the charge controlling agents adhered on the surface of the core is from 0.1 to 10% by weight based on the weight of the core.
Claim 7
Dependent Claim
48 words
A binder type carrier of the claim 1, in which said binder type carrier is obtained by electrostatically dusting the charge controlling agent on the surface of the core, and then adhering the charge controlling agent dusted on the surface of the core by melting the thermoplastic resin.
Claim 8
Dependent Claim
31 words
A binder type carrier of the claim 1, in which the charge controlling agent is a member selected from the group consisting of nigrosine dyes, metal-containing dyes and quaternary ammonium salts.
Claim 9
Dependent Claim
47 words
A binder type carrier of the claim 1, in which the core has a magnetic property; and the particles of the charge controlling agent are obtained by being electrostatically dusted on the surface of the core and then being thermally adhered to the surface of the core.
Claim 10
Dependent Claim
24 words
A binder type carrier of the claim 1, in which the core has a volumetric specific resistance of more than 10 13 ohm cm.
Claim 11
Dependent Claim
32 words
A binder type carrier of the claim 1, in which the ratio of the binder resin of the magnetic powder is 100 parts by weight to 200 to 900 parts by weight.
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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) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |