Patent US4822708A successfully refreshed from Google Patents.
US4822708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier for use in developing device of electrostatic latent image and production thereof
Assignee: Minolta Co Ltd
•
Filing: 1987-07-29
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Granted: 1989-04-18
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Expires: 2007-07-29
Abstract
Abstract The present invention provides a carrier coated by a polymer particle layer containing fine magnetic particles around a magnetic core, which may contain an electrical charge controlling agent, and the core may be pre-treated with a coupling reagent; the carrier gives excellent clearness to the copy and durability at repeating use.
Inventors
- 👤 Junji Machida
- 👤 Junji Ohtani
- 👤 Eiichi Sano
- 👤 Masahiro Anno
- 👤 Toshitaro Kohri
- 👤 Yukio Tanigami
- 👤 Makoto Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:19
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1139; G03G9/1131
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
56 words
A carrier for use in a developing device for an electrostatic latent image, which carrier comprises a magnetic core and a coating layer formed over said magnetic core, said coating layer comprising fine magnetic particles in an amount sufficient to provide said carrier with an electrical resistance of from 10 10 to 10 15 ohm cm.
Claim 2
Dependent Claim
56 words
A carrier for use in a developing device for an electrostatic latent image, which carrier comprises a magnetic core and a coating layer formed over said magnetic core, said coating layer comprising fine magnetic particles in an amount sufficient to provide said carrier with an electrical resistance of from 10 10 to 10 15 ohm cm.
Claim 3
Dependent Claim
20 words
A carrier of the claim 1, in which the average diameter of the core is from 20 to 200 micrometers.
Claim 4
Dependent Claim
21 words
A carrier of the claim 1, in which the average diameter of the polymer particles is from 0.6 to 10 micrometers.
Claim 5
Dependent Claim
22 words
A carrier of the claim 1, in which the average diameter of the fine magnetic particles is from 0.01 to 3 micrometers.
Claim 6
Dependent Claim
29 words
A carrier of the claim 1, in which the ratio of the coating layer containing the fine magnetic particles to the core is from 0.05:100 to 50:100 by weight.
Claim 7
Dependent Claim
26 words
A carrier of the claim 1, in which the ratio of the fine magnetic particles to the coating layer is from 100:100 to 800:100 by weight.
Claim 8
Dependent Claim
28 words
A carrier of the claim 1, in which the core is selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel alloy, cobalt, and cobalt alloy.
Claim 9
Dependent Claim
36 words
A carrier of the claim 1, in which the polymer particles are selected from the group consisting of homo- or copolymer of styrenes, acryl monomers, methacryl monomers, vinyl monomers, polyfunctional acrylates, polyfunctional methacrylates, and divinyl monomers.
Claim 10
Dependent Claim
30 words
A carrier of the claim 1, in which the fine magnetic particles are selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel alloy, cobalt, and cobalt alloy.
Claim 11
Dependent Claim
15 words
A carrier of the claim 1, in which the core is treated with coupling reagents.
Claim 12
Dependent Claim
31 words
A carrier of the claim 10, in which the coupling reagents are selected from the group consisting of silicone coupling reagents, titanate coupling reagents, zilconium coupling reagents and aluminium coupling reagents.
Claim 13
Dependent Claim
62 words
A carrier for use in a developing device for an electrostatic latent image, which carrier comprises a magnetic core and a coating layer formed over said magnetic core, wherein said coating layer comprises fine magnetic particles and electrical charge controlling agents in an amount sufficient to provide said carrier with an electrical resistance of from 10 10 to 10 15 ohm cm.
Claim 14
Dependent Claim
62 words
A carrier for use in a developing device for an electrostatic latent image, which carrier comprises a magnetic core and a coating layer formed over said magnetic core, wherein said coating layer comprises fine magnetic particles and electrical charge controlling agents in an amount sufficient to provide said carrier with an electrical resistance of from 10 10 to 10 15 ohm cm.
Claim 15
Dependent Claim
26 words
A carrier of the claim 12, in which said coating layer comprises polymer particles containing both said electrical charge controlling agents and said fine magnetic particles.
Claim 16
Dependent Claim
50 words
A carrier of the claim 12, in which the coating layer comprises polymer particles and electrical charge controlling agents, said polymer particles containing said fine magnetic particles and formed over the magnetic core, and said electrical charge controlling agents are formed to adhere to the surface of said polymer particles.
Claim 17
Dependent Claim
35 words
A carrier of the claim 12, in which the coating layer comprises two different types of polymer particles, one of which contains electrical charge controlling agents and the other of which contains fine magnetic particles.
Claim 18
Dependent Claim
34 words
A carrier of the claim 12, in which the electrical charge controlling agents are selected from the group consisting of nigrosines, thioindigos, salicylic acid metal chelating agents, and sulfonyl amine derivatives of copper phthalocyanines.
Claim 19
Dependent Claim
20 words
A carrier of the claim 12, in which the average diameter of the core is from 20 to 200 micrometers.
Claim 20
Dependent Claim
24 words
A carrier of the claim 13, 14 or 15, in which the average diameter of the polymer particles is from 0.6 to 10 micrometers.
Claim 21
Dependent Claim
22 words
A carrier of the claim 12, in which the average diameter of the fine magnetic particles is from 0.01 to 3 micrometers.
Claim 22
Dependent Claim
29 words
A carrier of the claim 12, in which the ratio of the coating layer containing the fine magnetic particles to the core is from 0.05:100 to 50:100 by weight.
Claim 23
Dependent Claim
29 words
A carrier of the claim 13, 14 or 15, in which the ratio of the fine magnetic particles to the polymer particles is from 100:100 to 800:100 by weight.
Claim 24
Dependent Claim
28 words
A carrier of the claim 12, in which the core is selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel alloy, cobalt, and cobalt alloy.
Claim 25
Dependent Claim
39 words
A carrier of the claim 13, 14 or 15, in which the polymer particles are selected from the group consisting of homo- or copolymer of styrenes, acryl monomers, methacryl monomers, vinyl monomers, polyfunctional acrylates, polyfunctional methacrylates, and divinyl monomers.
Claim 26
Dependent Claim
30 words
A carrier of the claim 12, in which the fine magnetic particles are selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel, alloy, cobalt, and cobalt alloy.
Claim 27
Dependent Claim
15 words
A carrier of the claim 12, in which the core is treated with coupling reagents.
Claim 28
Dependent Claim
31 words
A carrier of the claim 25, in which the coupling reagents are selected from the group consisting of silicone coupling reagents, titanate coupling reactant, zirconium coupling reagents and aluminium coupling reagents.
Claim 29
Independent Claim
62 words
A method of preparing a carrier for use in a developing device for an electrostatic latent image, which comprises homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles and having a smaller diameter than that of the magnetic cores, and welding the polymer particles on said magnetic core at a temperature higher than the softening point of the polymer particles.
Claim 30
Independent Claim
62 words
A method of preparing a carrier for use in a developing device for an electrostatic latent image, which comprises homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles and having a smaller diameter than that of the magnetic cores, and welding the polymer particles on said magnetic core at a temperature higher than the softening point of the polymer particles.
Claim 31
Dependent Claim
28 words
A method of preparing a carrier of the claim 27, in which the magnetic cores are treated with coupling reagents before mixing the cores and the polymer particles.
Claim 32
Dependent Claim
18 words
A method of the claim 27, in which the welding process is carried out under an inert atmosphere.
Claim 33
Dependent Claim
20 words
A method of the claim 27, in which the average diameter of the cores is from 20 to 200 micrometers.
Claim 34
Dependent Claim
21 words
A method of the claim 27, in which the average diameter of the polymer particles is from 0.6 to 10 micrometers.
Claim 35
Dependent Claim
22 words
A method of the claim 27, in which the average diameter of the fine magnetic particles is from 0.01 to 3 micrometers.
Claim 36
Dependent Claim
29 words
A carrier of the claim 27, in which the ratio of the polymer particles containing the fine magnetic particles to the core is from 0.05:100 to 50:100 by weight.
Claim 37
Dependent Claim
26 words
A method of the claim 27, in which the ratio of the fine magnetic particles to the polymer particles is from 100:100 to 800:100 by weight.
Claim 38
Dependent Claim
28 words
A method of the claim 27, in which the core is selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel alloy, cobalt, and cobalt alloy.
Claim 39
Dependent Claim
36 words
A method of the claim 27, in which the polymer particles are selected from the group consisting of homo- or copolymer of styrenes, acryl monomers, methacryl monomers, vinyl monomers, polyfunctional acrylates, polyfunctional methacrylates, and divinyl monomers.
Claim 40
Dependent Claim
30 words
A method of the claim 27, in which the fine magnetic particles are selected from the group consisting of ferrite, iron, iron alloy, nickel, nickel alloy, cobalt, and cobalt alloy.
Claim 41
Independent Claim
65 words
A method of preparing carriers for use in a developing device for an electrostatic latent image, which comprises homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles and electrical charge controlling agents, in which the polymer particle is smaller than the cores, and welding the polymer particles on the magnetic cores at a temperature higher than the softening point of the polymer particle.
Claim 42
Independent Claim
65 words
A method of preparing carriers for use in a developing device for an electrostatic latent image, which comprises homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles and electrical charge controlling agents, in which the polymer particle is smaller than the cores, and welding the polymer particles on the magnetic cores at a temperature higher than the softening point of the polymer particle.
Claim 43
Dependent Claim
20 words
A method of the claim 38, in which the welding process is carried out under atmosphere of an inert gas.
Claim 44
Dependent Claim
25 words
A method of the claim 38, in which the magnetic cores are treated with coupling reagents before the cores and the polymer particles are mixed.
Claim 45
Independent Claim
57 words
A method of preparing carriers for use in a developing device for an electrostatic latent image comprising homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles, in which the polymer particles are smaller than the cores, and welding the polymer particles on the magnetic cores, and coating electrical charge controlling agents on the polymer-welded cores.
Claim 46
Independent Claim
57 words
A method of preparing carriers for use in a developing device for an electrostatic latent image comprising homogeneously mixing magnetic cores with polymer particles containing fine magnetic particles, in which the polymer particles are smaller than the cores, and welding the polymer particles on the magnetic cores, and coating electrical charge controlling agents on the polymer-welded cores.
Claim 47
Dependent Claim
19 words
A method of claim 41, in which the welding process is carried out under atmosphere of an inert gas.
Claim 48
Dependent Claim
24 words
A method of claim 41, in which the magnetic cores are treated with coupling reagents before the cores and the polymer particles are mixed.
Claim 49
Dependent Claim
18 words
A carrier of the claim 1, in which the coating layer comprises polymer particles containing fine magnetic particles.
Claim 50
Dependent Claim
25 words
A carrier of claim 1, in which the ratio of the fine magnetic particles to the coating layer is from 300:100 to 700:100 by weight.
Claim 51
Dependent Claim
25 words
A carrier of claim 1, in which the ratio of the fine magnetic particles to the coating layer is from 400:100 to 600:100 by weight.
Claim 52
Dependent Claim
29 words
A carrier of the claim 13, 14 or 15, in which the ratio of the fine magnetic particles to the polymer particles is from 300:100 to 700:100 by weight.
Claim 53
Dependent Claim
29 words
A carrier of the claim 13, 14 or 15, in which the ratio of the fine magnetic particles to the polymer particles is from 400:100 to 600:100 by weight.
Claim 54
Dependent Claim
26 words
A method of the claim 27, in which the ratio of the fine magnetic particles to the polymer particles is from 300:100 to 700:100 by weight.
Claim 55
Dependent Claim
26 words
A method of the claim 27, in which the ratio of the fine magnetic particles to the polymer particles is from 400:100 to 600:100 by weight.
References Cited (Backward Citations)
US31072A
Cited
US3533835A
Cited
US3669885A
Cited
US3720617A
Cited
US3840464A
Cited
US3873356A
Cited
US3795618A
Cited
US3898170A
Cited
US3916065A
Cited
USRE31072E
Cited
US4013573A
Cited
US4596812A
Cited
US4062693A
Cited
JPS57122449A
Cited
JPS57190957A
Cited
US4518673A
Cited
JPS5937553A
Cited
US4555466A
Cited
JPS5969762A
Cited
US4493855A
Cited
JPS59200262A
Cited
JPS59201064A
Cited
JPS59223458A
Cited
US4517268A
Cited
JPS60107038A
Cited
JPS60147750A
Cited
US4600675A
Cited
JPS60170865A
Cited
US4609603A
Cited
US4672016A
Cited
US4717720A
Cited
JPH0650543A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |