Patent US4666813A successfully refreshed from Google Patents.
US4666813A
Expired / Lapsed
US
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Developer for developing electrostatic latent images contains vinylidene fluoride polymer
Assignee: Canon Inc
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Filing: 1986-01-03
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Granted: 1987-05-19
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Expires: 2006-01-03
Abstract
Abstract A developer for developing electrostatic latent images, comprising toner particles and particles of a fluorine-containing substance as represented by a vinylidene fluoride polymer having a specific randomness in molecular structure or crystalline structure. The randomness of the vinylidene fluoride polymer is defined by the absorption peak ratio in the F19 nuclear magnetic resonance spectrum in acetone or by the absolute beta -crystal content of the vinylidene fluoride polymer. The vinylidene fluoride polymer provides a friction reducing characteristic to the developer while retaining good developing characteristic under various conditions.
Inventors
- 👤 Kiichiro Sakashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:25
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/087; G03G9/08702; G03G9/08713; G03G9/0872
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
68 words
A developer for developing electrostatic latent images, comprising toner particles and particles of a fluorine-containing substance, said fluorine-containing substance satisfying the relationship based on the F 19 nuclear magnetic resonance spectrum thereof in acetone of: (Sb+Sc+Sd)/Sa≧0.20, wherein Sa, Sb, Sc and Sd are areas of absorption peaks at about -23.5±1 ppm, about -27.5±1 ppm, about -45.8±1 ppm, and about 48.1±1 ppm, respectively, with 1,1,2-trichloro-1,2,2-trifluoroethane as the reference substance.
Claim 2
Dependent Claim
68 words
A developer for developing electrostatic latent images, comprising toner particles and particles of a fluorine-containing substance, said fluorine-containing substance satisfying the relationship based on the F 19 nuclear magnetic resonance spectrum thereof in acetone of: (Sb+Sc+Sd)/Sa≧0.20, wherein Sa, Sb, Sc and Sd are areas of absorption peaks at about -23.5±1 ppm, about -27.5±1 ppm, about -45.8±1 ppm, and about 48.1±1 ppm, respectively, with 1,1,2-trichloro-1,2,2-trifluoroethane as the reference substance.
Claim 3
Dependent Claim
38 words
A developer according to claim 1, wherein said fluorine-containing substance is a vinylidene fluoride polymer selected from the group consisting of homopolymer of vinylidene fluoride and a copolymer of vinylidene fluoride with ethylene, vinyl fluoride, trifluoroethylene or tetrafluoroethylene.
Claim 4
Dependent Claim
24 words
A developer according to claim 2, wherein said vinylidene fluoride polymer is contained in an amount of 0.01 to 2.0 wt.% of the toner.
Claim 5
Dependent Claim
20 words
A developer according to claim 2, wherein said vinylidene fluoride polymer has a weight-average molecular weight of 100,000 to 800,000.
Claim 6
Dependent Claim
21 words
A developer according to claim 4, wherein said vinylidene fluoride polymer has an average particle size of 0.05 to 1 μm.
Claim 7
Dependent Claim
31 words
A developer according to claim 1, which further comprises inorganic fine powder having a BET specific surface area according to the nitrogen adsorption method of 0.5 to 500 m 2 /g.
Claim 8
Dependent Claim
16 words
A developer according to claim 6, wherein said inorganic fine powder is hydrophobic colloidal silica powder.
Claim 9
Dependent Claim
49 words
A developer according to claim 1, wherein said toner particles contain magnetic particles having a BET specific surface area according to the nitrogen adsorption method of 2 to 20 m 2 /g with a Mohs' hardness of 5-7, and hydrophobic colloidal silica powder is co-present with the fluorine-containing substance.
Claim 10
Dependent Claim
23 words
A developer according to claim 8, wherein said magnetic powder is contained in an amount of 10 to 70 wt.% of the toner.
Claim 11
Dependent Claim
11 words
A developer according to claim 1, which further comprises carrier particles.
Claim 12
Dependent Claim
26 words
A developer for developing electrostatic latent images, comprising toner particles and particles of a vinylidene fluoride polymer having an absolute β-crystal content of 0.30 or above.
Claim 13
Dependent Claim
26 words
A developer for developing electrostatic latent images, comprising toner particles and particles of a vinylidene fluoride polymer having an absolute β-crystal content of 0.30 or above.
Claim 14
Dependent Claim
39 words
A developer according to claim 11, wherein said vinylidene fluoride polymer is homopolymer of vinylidene fluoride or a copolymer of vinylidene fluoride with a monomer selected from the group consisting of vinyl fluoride, trifluroethylene, tetrafluoroethylene, ethylene, propylene and butene.
Claim 15
Dependent Claim
24 words
A developer according to claim 11, wherein said vinylidene fluoride polymer is contained in an amount of 0.01 to 20 wt.% of the toner.
Claim 16
Dependent Claim
20 words
A developer according to claim 11, wherein said vinylidene fluoride polymer has a weight-average molecular weight of 100,000 to 800,000.
Claim 17
Dependent Claim
21 words
A developer according to claim 11, wherein said vinylidene fluoride polymer has an average particle size of 0.05 to 1 μm.
Claim 18
Dependent Claim
31 words
A developer according to claim 11, which further comprises inorganic fine powder having a BET specific surface area according to the nitrogen adsorption method of 0.5 to 500 m 2 /g.
Claim 19
Dependent Claim
16 words
A developer according to claim 16, wherein said inorganic fine powder is hydrophobic colloidal silica powder.
Claim 20
Dependent Claim
50 words
A developer according to claim 11, wherein said toner particles contain magnetic powder having a BET specific surface area according to the nitrogen adsorption method of 2 to 20 m 2 /g with a Mohs' hardness of 5-7, and hydrophobic colloidal silica powder is co-preset with the vinylidene fluoride polymer.
Claim 21
Dependent Claim
23 words
A developer according to claim 18, wherein said magnetic powder is contained in an amount of 10 to 70 wt.% of the toner.
Claim 22
Dependent Claim
11 words
A developer according to claim 11, which further comprises carrier particles.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |