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US5041351A
Expired / Lapsed
US
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One component developer for developing electrostatic image and image forming method
Assignee: Canon Inc
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Filing: 1989-03-28
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Granted: 1991-08-20
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Expires: 2009-03-28
Abstract
Abstract A developer for developing electrostatic images, comprising: at least, 100 wt. parts of a negatively chargeable magnetic toner having a volume-average particle size of 5 to 30 microns; 0.1 to 3 wt. parts of potitively chargeable resin particles having an average particle size of 0.1 to 1.0 micron; and 0.05 to 3 wt. parts of hydrophobic silica fine powder having a triboelectric chargeability of -100 to -300 μc/g.
Inventors
- 👤 Naoto Kitamori
- 👤 Hisayuki Ochi
- 👤 Tetsuya Kuribayashi
- 👤 Manabu Ohno
- 👤 Tetsuhito Kuwashima
- 👤 Hitoshi Uchide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:53
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/09708; G03G9/09725; G03G9/0819; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/104
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
68 words
A developer for developing electrostatic images, comprising, at least, 100 wt. parts of a negatively chargeable magnetic toner having a volume-average particle size of 5 to 30 microns; 0.1 to 3 wt. parts of positively chargeable resin particles having an average particle size of 0.1 to 1.0 micron; and 0.05 to 3 wt. parts of hydrophobic silica fine powder having a triboelectric chargeability of -100 to -300 μc/g.
Claim 2
Dependent Claim
68 words
A developer for developing electrostatic images, comprising, at least, 100 wt. parts of a negatively chargeable magnetic toner having a volume-average particle size of 5 to 30 microns; 0.1 to 3 wt. parts of positively chargeable resin particles having an average particle size of 0.1 to 1.0 micron; and 0.05 to 3 wt. parts of hydrophobic silica fine powder having a triboelectric chargeability of -100 to -300 μc/g.
Claim 3
Dependent Claim
22 words
A developer according to claim 1, wherein the positively chargeable resin particles have a triboelectric chargeability of +50 μc/g to +600 μc/g.
Claim 4
Dependent Claim
22 words
A developer according to claim 1, wherein the positively chargeable resin particles have a triboelectric chargeability of +100 μc/g to +600 μc/g.
Claim 5
Dependent Claim
22 words
A developer according to claim 1, wherein the positively chargeable resin particles have an average particle size of 0.2 to 1.0 micron.
Claim 6
Dependent Claim
25 words
A developer according to claim 1, wherein the positively chargeable resin particles have a ratio of longer axis to shorter axis of 1.0 to 1.02.
Claim 7
Dependent Claim
18 words
A developer according to claim 5, wherein the positively chargeable resin particles have a spherical or spheroidal shape.
Claim 8
Dependent Claim
51 words
A developer according to claim 1, wherein the positively chargeable resin particles have a triboelectric chargeability of +50 μc/g to +600 μc/g and an average particle size of 0.2 to 1.0 micron and a spherical or spheroidal shape having a ratio of longer axis to shorter axis of 1.0 to 1.02.
Claim 9
Dependent Claim
21 words
A developer according to claim 7, wherein the positively chargeable resin particles have a triboelectric chargeability +100 μc/g to +600 μc/g.
Claim 10
Dependent Claim
24 words
A developer according to claim 1, wherein the positively chargeable resin particles comprise a resin having a weight-average molecular weight of 100,000 to 200,000.
Claim 11
Dependent Claim
46 words
A developer according to claim 1, wherein the positively chargeable resin particles comprise a resin obtained by polymerizing a vinyl monomer or a mixture thereof selected from the group consisting of methyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, N-methyl-N-phenylaminoethyl methacrylate, diethylaminoethyl methacrylamide, dimethylaminoethyl methacrylamide, 4-vinylpyridine and 2-vinylpyridine.
Claim 12
Dependent Claim
24 words
A developer according to claim 7, wherein the positively chargeable resin particles comprise a resin having a weight-average molecular weight of 100,000 to 200,000.
Claim 13
Dependent Claim
46 words
A developer according to claim 11, wherein the positively chargeable resin particles comprise a resin obtained by polymerizing a vinyl monomer or a mixture thereof selected from the group consisting of methyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, N-methyl-N-phenylaminoethyl methacrylate, diethylaminoethyl methacrylamide, dimethylaminoethyl methacrylamide, 4-vinylpyridine and 2-vinylpyridine.
Claim 14
Dependent Claim
24 words
A developer according to claim 1, wherein the positively chargeable resin particles have a specific electric resistance of 10 8 to 10 14 ohm/cm.
Claim 15
Dependent Claim
28 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner comprise at least a binder resin comprising a vinyl-type polymer or copolymer and a magnetic material.
Claim 16
Dependent Claim
30 words
A developer according to claim 14, wherein the negatively chargeable magnetic toner contains a binder resin selected from the group consisting of styrene-n-butyl acrylate, styrene-n-butyl methacrylate, and styrene-n-butyl acrylate-2-ethylhexyl methacrylate.
Claim 17
Dependent Claim
28 words
A developer according to claim 14, wherein the negatively chargeable magnetic toner contains a binder resin of which tetrahydrofuran-soluble has a weight-average molecular weight of 100,000 to 200,000.
Claim 18
Dependent Claim
29 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner contains a magnetic material having a BET specific surface areas of 2 to 20 m 2 /g.
Claim 19
Dependent Claim
29 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner contains a magnetic material having a BET specific surface area of 2.5 to 12 m 2 /g.
Claim 20
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner contains a magnetic material having a Mohs' hardness of 5-7.
Claim 21
Dependent Claim
26 words
A developer according to claim 1, wherein the negatively chargeable toner contains 10 to 70wt.% of a magnetic material based on the weight of the toner.
Claim 22
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a volume resistivity of 10 10 ohm.cm or larger.
Claim 23
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a volume resistivity of 10 12 ohm/cm or larger.
Claim 24
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a triboelectric chargeability of -8 μc/g to -40 μc/g.
Claim 25
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a triboelectric chargeability of -8 μc/g to -20 μc/g.
Claim 26
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a volume-average particle size of 5 to 30 microns.
Claim 27
Dependent Claim
22 words
A developer according to claim 11, wherein the negatively chargeable magnetic toner has a volume-average particle size of 6 to 15 microns.
Claim 28
Dependent Claim
22 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a volume-average particle size of 7 to 15 microns.
Claim 29
Dependent Claim
23 words
A developer according to claim 1, wherein the hydrophobic silica fine powder has a BET specific surface area of 70-300 m 2 /g.
Claim 30
Dependent Claim
22 words
A developer according to claim 1, wherein the hydrophobic silica fine powder has an average particle size of 5 to 30 microns.
Claim 31
Dependent Claim
25 words
A developer according to claim 1, wherein the hydrophobic silica fine powder has a hydrophobicity of 30 to 80 according to a methanol titration test.
Claim 32
Dependent Claim
34 words
A developer according to claim 1, wherein he hydrophobic silica fine powder has been mixed with 100 wt. parts of the negatively chargeable magnetic toner in an amount of 0.1 to 2 wt. parts.
Claim 33
Dependent Claim
28 words
A developer according to claim 1, wherein the addition amount of the hydrophobic silica fine powder to that of the positively chargeable resin particles is 1:0.1 to 1:60.
Claim 34
Dependent Claim
28 words
A developer according to claim 1, wherein the addition amount of the hydrophobic silica fine powder to that of the positively chargeable resin particles is 1:0.1 to 1:10.
Claim 35
Dependent Claim
162 words
A developer according to claim 1, wherein the negatively chargeable magnetic toner has a volume-average particle size of 5-30 microns, a triboelectric chargeability of -8 μc/g to -20 μc/g and a volume resistivity of 10 12 or larger, and comprises a binder resin comprising a vinyl-type polymer or copolymer, 10 to 70 wt.% of a magnetic material and a negative charge control agent; the positively chargeable resin particles have a triboelectric chargeability of +100 μc/g to +600 μc/g, an average particle size of 0.2 to 1.0 micron, a spherical or spheroidal shape having a ratio of longer axis to shorter axis of 1.0 to 1.02, and a specific electric resistance of 10 8 -10 14 ohm.cm, and comprise a vinyl-type resin having a weight-average molecular weight of 100,000 to 200,000; and the hydrophobic silica fine powder has a BET specific surface area of 70 to 300 m 2 /g and a hydrophobicity of 30 to 80 based on a methanol titration test.
Claim 36
Dependent Claim
31 words
A developer according to claim 34, wherein the ratio of the addition amount of the hydrophobic silica fine powder to that of the positively chargeable resin particles is 1:01.1 to 1:60.
Claim 37
Dependent Claim
13 words
A developer according to claim 34, which has an agglomeration degree of 70-95%.
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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) | 1994-08-19 | 1995-02-18 | 1995-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-19 | 1999-02-18 | 1999-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-19 | 2003-02-18 | 2003-08-20 | $7700.00 | Window Closed / Lapsed |