EP0801335A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic coated carrier, two-component type developer and developing method
Assignee: Canon Inc
•
Filing: 1997-04-07
•
Granted: —
•
Expires: 2017-04-07
Abstract
Abstract A magnetic coated carrier suitable for constituting a two-component type developer for use in electrophotography is composed of magnetic coated carrier particles comprising magnetic coated carrier particles comprising magnetic carrier core particles each comprising a binder resin and metal oxide particles, and a coating layer surface-coating each carrier core particle. The metal oxide particles have been subjected to a surface lipophilicity-imparting treatment. The magnetic carrier core particles have a resistivity of at least 1x10 10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm. The magnetic coated carrier has a particle size distribution such that (i) it has a number-average particle size Dn of 5 - 100 µm, (ii) it satisfies a relationship of Dn/σ ≧ 3.5, wherein σ denotes a standard deviation of number-basis particle size distribution of the carrier, and (iii) it contains at least 25 % by number of particles having particle sizes of at most Dn x 2/3.
Inventors
- 👤 Yoshinobu Baba
- 👤 Takeshi Ikeda
- 👤 Yuko Sato
- 👤 Hitoshi Itabashi
- 👤 Yuzo Tokunaga
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 07:39
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0821; G03G9/0827; G03G9/10; G03G9/107; G03G9/1075; G03G9/108; G03G9/1085; G03G9/1088; G03G9/10882; G03G9/10884; G03G9/113; G03G9/1132; G03G9/1135; G03G9/1136
Claims Analysis
Total Claims: 89
Claim 1
Independent Claim
141 words
A magnetic coated carrier, comprising: magnetic coated carrier particles comprising magnetic carrier core particles each comprising a binder resin and metal oxide particles, and a coating layer surface-coating each carrier core particle, wherein the metal oxide particles have been subjected to a surface lipophilicity-imparting treatment, the magnetic carrier core particles have a resistivity of at least 1x10 10 ohm.cm, the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, and the magnetic coated carrier has a particle size distribution such that (i) it has a number-average particle size Dn of 5 - 100 µm, (ii) it satisfies a relationship of Dn/σ ≧ 3.5, wherein σ denotes a standard deviation of number-basis particle size distribution of the carrier, and (iii) it contains at least 25 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 2
Dependent Claim
14 words
The magnetic coated carrier according to Claim 1, wherein the binder resin is crosslinked.
Claim 3
Dependent Claim
16 words
The magnetic coated carrier according to Claim 1, wherein the binder resin comprises a thermosetting resin.
Claim 4
Dependent Claim
15 words
The magnetic coated carrier according to Claim 1, wherein the coating layer comprises a resin.
Claim 5
Dependent Claim
31 words
The magnetic coated carrier according to Claim 1, wherein the magnetic carrier core particles have been prepared by polymerization, and the carrier has a shape factor SF-1 of 100 - 130.
Claim 6
Dependent Claim
44 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been lipophilized by at least one species selected from the group consisting of a silane coupling agent, a titanate coupling agent, an aluminum coupling agent and a surface active agent.
Claim 7
Dependent Claim
105 words
The magnetic coated carrier according to Claim 1, wherein the magnetic carrier core particles comprise at least two species of metal oxide particles in a total amount of 50 - 99 wt. % including at least one species of ferromagnetic metal oxide particles and another species of non-magnetic metal oxide particles having a higher resistivity than the ferromagnetic metal oxide particles; said another species of metal oxide particles have a number-average particle size which is larger than and at most 5 times that of the ferromagnetic metal oxide particles; and the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/g.
Claim 8
Dependent Claim
22 words
The magnetic coated carrier according to Claim 1, wherein the binder resin of the magnetic carrier core particles comprise a phenolic resin.
Claim 9
Dependent Claim
26 words
The magnetic coated carrier according to Claim 7, wherein said ferromagnetic metal oxide particles comprise magnetite and said another species of metal oxide particles comprise hematite.
Claim 10
Dependent Claim
35 words
The magnetic coated carrier according to Claim 7, wherein the metal oxide particles are exposed to the surface of the magnetic coated carrier particles at an average rate of 0.1 - 10 particles/µm 2 .
Claim 11
Dependent Claim
24 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier has a number-average particle size (Dn) of 10 - 70 µm.
Claim 12
Dependent Claim
22 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier has a shape factor SF-1 of 100 - 130.
Claim 13
Dependent Claim
31 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier contains at most 15 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 14
Dependent Claim
31 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier contains at most 10 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 15
Dependent Claim
17 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier satisfies Dn/σ ≧ 4.0.
Claim 16
Dependent Claim
24 words
The magnetic coated carrier according to Claim 7, wherein said ferromagnetic metal oxide particles have a number-average particle size of 0.02 - 2 µm.
Claim 17
Dependent Claim
24 words
The magnetic coated carrier according to Claim 7, wherein said non-magnetic metal oxide particles have a number-average particle size of 0.05 - 5 µm.
Claim 18
Dependent Claim
23 words
The magnetic coated carrier according to Claim 7, wherein said ferromagnetic metal oxide particles have a resistivity of at least 1x10 3 ohm.cm.
Claim 19
Dependent Claim
23 words
The magnetic coated carrier according to Claim 7, wherein said non-magnetic metal oxide particles have a resistivity of at least 1x10 8 ohm.cm.
Claim 20
Dependent Claim
23 words
The magnetic coated carrier according to Claim 7, wherein said non-magnetic metal oxide particles have a resistivity of at least 1x10 10 ohm.cm.
Claim 21
Dependent Claim
32 words
The magnetic coated carrier according to Claim 7, wherein the ferromagnetic metal oxide particles occupy 30 - 95 wt. % of the total metal oxide particles in the magnetic carrier core particles.
Claim 22
Dependent Claim
25 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been treated with a silane coupling agent having an amino group.
Claim 23
Dependent Claim
34 words
The magnetic coated carrier according to Claim 22, wherein said silane coupling agent having an amino group is a compound selected from the group consisting of: γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.
Claim 24
Dependent Claim
25 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been treated with a silane coupling agent having a hydrophobic group.
Claim 25
Dependent Claim
42 words
The magnetic coated carrier according to Claim 24, wherein said silane coupling agent having a hydrophobic group is a silane coupling agent having alkyl group, alkenyl group, halogenated alkyl group, halogenated alkenyl group, phenyl group, halogenated phenyl group, or alkyl phenyl group.
Claim 26
Dependent Claim
53 words
The magnetic coated carrier according to Claim 24, wherein said silane coupling agent having a hydrophobic group comprises an alkoxysilane represented by the following formula: R m SiY n , wherein R denotes an alkoxy group, Y denotes an alkyl or vinyl group, and m and n are integers of 1 - 3.
Claim 27
Dependent Claim
41 words
The magnetic coated carrier according to Claim 24, wherein said silane coupling agent having a hydrophobic group is a compound selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, and vinyltris(β-methoxy)silane.
Claim 28
Dependent Claim
39 words
The magnetic coated carrier according to Claim 24, wherein said silane coupling agent having a hydrophobic group is a compound selected from the group consisting of vinyltrichlorosilane, hexamethyldisilazane, trimethylsilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, a-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, and chloromethyldimethylchlorosilane.
Claim 29
Dependent Claim
25 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been treated with a silane coupling agent having an epoxy group.
Claim 30
Dependent Claim
25 words
The magnetic coated carrier according to Claim 29, wherein said coupling agent is a compound selected from the group consisting of γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)trimethoxysilane.
Claim 31
Dependent Claim
42 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a silane coupling agent or a titanate coupling agent in an amount of 0.1 - 10 wt. parts per 100 wt. parts thereof.
Claim 32
Dependent Claim
42 words
The magnetic coated carrier according to Claim 1, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a silane coupling agent or a titanate coupling agent in an amount of 0.2 - 6 wt. parts per 100 wt. parts thereof.
Claim 33
Dependent Claim
24 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/g.
Claim 34
Dependent Claim
24 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier has a magnetization at 1 kilo-oersted of 50 - 230 emu/g.
Claim 35
Dependent Claim
158 words
A two-component type developer for developing an electrostatic image, comprising: a toner and a magnetic coated carrier; wherein the magnetic coated carrier comprises magnetic coated carrier particles comprising magnetic carrier core particles each comprising a binder resin and metal oxide particles, and a coating layer surface-coating each carrier core particle, wherein the metal oxide particles have been subjected to a surface lipophilicity-imparting treatment, the magnetic carrier core particles have a resistivity of at least 1x10 10 ohm.cm, the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, and the magnetic coated carrier has a particle size distribution such that (i) it has a number-average particle size Dn of 5 - 100 µm, (ii) it satisfies a relationship of·Dn/σ ≧ 3.5, wherein σ denotes a standard deviation of number-basis particle size distribution of the carrier, and (iii) it contains at least 25 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 36
Dependent Claim
20 words
The developer according to Claim 35, wherein the toner has a weight-average particle size (D4) of 1 - 10 µm.
Claim 37
Dependent Claim
19 words
The developer according to Claim 35, wherein the toner has a weight-average particle size of 3 - 8 µm.
Claim 38
Dependent Claim
54 words
The developer according to Claim 35, wherein the toner contains at most 20 % by number of toner particles having sizes of at most a half its number-average particle size (D1) and contains at most 10 % by volume of toner particles having sizes of at last two times its weight-average particle size (D4).
Claim 39
Dependent Claim
35 words
The developer according to Claim 35, wherein the magnetic coated carrier has a number-average particle size (Dn) of 15 - 50 µm, and the toner has a weight-average particle size (D4) of 3 - 8.
Claim 40
Dependent Claim
28 words
The developer according to Claim 35, wherein the toner has a shape factor SF-1 of 100 - 140, and a residual monomer content of at most 1000 rpm.
Claim 41
Dependent Claim
19 words
The developer according to Claim 40, wherein the toner has a residual monomer content of at most 500 ppm.
Claim 42
Dependent Claim
28 words
The developer according to Claim 35, wherein the toner has a shape factor SF-1 of 100 - 130, and a residual monomer content of at most 300 rpm.
Claim 43
Dependent Claim
17 words
The developer according to Claim 35, wherein the toner comprises toner particles each having a core/shell structure.
Claim 44
Dependent Claim
28 words
The developer according to Claim 43, wherein each toner particle has a core comprising a low-softening point substance, which has a melting point of 40 - 90 °C.
Claim 45
Dependent Claim
22 words
The developer according to Claim 44, wherein the toner particles contain 5 - 30 wt. % thereof of the low-softening point substance.
Claim 46
Dependent Claim
27 words
The developer according to Claim 35, wherein the toner comprises toner particles and a powdery external additive having a number-average particle size of at most 0.2 µm.
Claim 47
Dependent Claim
29 words
The developer according to Claim 46, wherein the external additive is contained in an amount of 0.01 - 10 wt. parts per 100 wt. parts of the toner particles.
Claim 48
Dependent Claim
29 words
The developer according to Claim 46, wherein the external additive is contained in an amount of 0.05 - 5 wt. parts per 100 wt. parts of the toner particles.
Claim 49
Dependent Claim
24 words
The developer according to Claim 35, wherein the toner has a triboelectric chargeability of 5 - 100 µC/g in terms of an absolute value.
Claim 50
Dependent Claim
24 words
The developer according to Claim 35, wherein the toner has a triboelectric chargeability of 5 - 60 µC/g in terms of an absolute value.
Claim 51
Dependent Claim
12 words
The developer according to Claim 35, wherein the binder resin is crosslinked.
Claim 52
Dependent Claim
14 words
The developer according to Claim 35, wherein the binder resin comprises a thermosetting resin.
Claim 53
Dependent Claim
13 words
The developer according to Claim 35, wherein the coating layer comprises a resin.
Claim 54
Dependent Claim
29 words
The developer according to Claim 35, wherein the magnetic carrier core particles have been prepared by polymerization, and the carrier has a shape factor SF-1 of 100 - 130.
Claim 55
Dependent Claim
42 words
The developer according to Claim 35, wherein the metal oxide particles have been lipophilized by at least one species selected from the group consisting of a silane coupling agent, a titanate coupling agent, an aluminum coupling agent and a surface active agent.
Claim 56
Dependent Claim
103 words
The developer according to Claim 35, wherein the magnetic carrier core particles comprise at least two species of metal oxide particles in a total amount of 50 - 99 wt. % including at least one species of ferromagnetic metal oxide particles and another species of non-magnetic metal oxide particles having a higher resistivity than the ferromagnetic metal oxide particles; said another species of metal oxide particles have a number-average particle size which is larger than and at most 5 times that of the ferromagnetic metal oxide particles; and the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/g.
Claim 57
Dependent Claim
20 words
The developer according to Claim 35, wherein the binder resin of the magnetic carrier core particles comprise a phenolic resin.
Claim 58
Dependent Claim
24 words
The developer according to Claim 35, wherein said ferromagnetic metal oxide particles comprise magnetite and said another species of metal oxide particles comprise hematite.
Claim 59
Dependent Claim
33 words
The developer according to Claim 56, wherein the metal oxide particles are exposed to the surface of the magnetic coated carrier particles at an average rate of 0.1 - 10 particles/µm 2 .
Claim 60
Dependent Claim
22 words
The developer according to Claim 35, wherein the magnetic coated carrier has a number-average particle size (Dn) of 10 - 70 µm.
Claim 61
Dependent Claim
20 words
The developer according to Claim 35, wherein the magnetic coated carrier has a shape factor SF-1 of 100 - 130.
Claim 62
Dependent Claim
29 words
The developer according to Claim 35, wherein the magnetic coated carrier contains at most 15 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 63
Dependent Claim
29 words
The developer according to Claim 35, wherein the magnetic coated carrier contains at most 10 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 64
Dependent Claim
15 words
The developer according to Claim 35, wherein the magnetic coated carrier satisfies Dn/σ ≧ 4.0.
Claim 65
Dependent Claim
22 words
The developer according to Claim 56, wherein said ferromagnetic metal oxide particles have a number-average particle size of 0.02 - 2 µm.
Claim 66
Dependent Claim
22 words
The developer according to Claim 56, wherein said non-magnetic metal oxide particles have a number-average particle size of 0.05 - 5 µm.
Claim 67
Dependent Claim
21 words
The developer according to Claim 56, wherein said ferromagnetic metal oxide particles have a resistivity of at least 1x10 3 ohm.cm.
Claim 68
Dependent Claim
21 words
The developer according to Claim 56, wherein said non-magnetic metal oxide particles have a resistivity of at least 1x10 8 ohm.cm.
Claim 69
Dependent Claim
21 words
The developer according to Claim 56, wherein said non-magnetic metal oxide particles have a resistivity of at least 1x10 10 ohm.cm.
Claim 70
Dependent Claim
30 words
The developer according to Claim 56, wherein the ferromagnetic metal oxide particles occupy 30 - 95 wt. % of the total metal oxide particles in the magnetic carrier core particles.
Claim 71
Dependent Claim
23 words
The developer according to Claim 35, wherein the metal oxide particles have been treated with a silane coupling agent having an amino group.
Claim 72
Dependent Claim
32 words
The developer according to Claim 71, wherein said silane coupling agent having an amino group is a compound selected from the group consisting of: γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.
Claim 73
Dependent Claim
23 words
The developer according to Claim 35, wherein the metal oxide particles have been treated with a silane coupling agent having a hydrophobic group.
Claim 74
Dependent Claim
40 words
The developer according to Claim 73, wherein said silane coupling agent having a hydrophobic group is a silane coupling agent having alkyl group, alkenyl group, halogenated alkyl group, halogenated alkenyl group, phenyl group, halogenated phenyl group, or alkyl phenyl group.
Claim 75
Dependent Claim
51 words
The developer according to Claim 73, wherein said silane coupling agent having a hydrophobic group comprises an alkoxysilane represented by the following formula: R m SiY n , wherein R denotes an alkoxy group, Y denotes an alkyl or vinyl group, and m and n are integers of 1 - 3.
Claim 76
Dependent Claim
39 words
The developer according to Claim 73, wherein said silane coupling agent having a hydrophobic group is a compound selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, and vinyltris(β-methoxy)silane.
Claim 77
Dependent Claim
37 words
The developer according to Claim 73, wherein said silane coupling agent having a hydrophobic group is a compound selected from the group consisting of vinyltrichlorosilane, hexamethyldisilazane, trimethylsilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, and chloromethyldimethylchlorosilane.
Claim 78
Dependent Claim
23 words
The developer according to Claim 35, wherein the metal oxide particles have been treated with a silane coupling agent having an epoxy group.
Claim 79
Dependent Claim
23 words
The developer according to Claim 78, wherein said coupling agent is a compound selected from the group consisting of γ-glycidoxy-propylmethyldiethoxysilane, γ-glycidoxypropyl-triethoxysilane, and β-(3,4-epoxycyclohexyl)-trimethoxysilane.
Claim 80
Dependent Claim
40 words
The developer according to Claim 35, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a silane coupling agent or a titanate coupling agent in an amount of 0.1 - 10 wt. parts per 100 wt. parts thereof.
Claim 81
Dependent Claim
40 words
The developer according to Claim 35, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a silane coupling agent or a titanate coupling agent in an amount of 0.2 - 6 wt. parts per 100 wt. parts thereof.
Claim 82
Dependent Claim
22 words
The developer according to Claim 35, wherein the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/g.
Claim 83
Dependent Claim
22 words
The developer according to Claim 35, wherein the magnetic coated carrier has a magnetization at 1 kilo-oersted of 50 - 230 emu/g.
Claim 84
Dependent Claim
216 words
A developing method, comprising: carrying a two-component type developer on a developer-carrying member enclosing therein a magnetic field generating means, forming a magnetic brush of the two-component type developer on the developer-carrying member, causing the magnetic brush to contact an image-bearing member, and developing an electrostatic image on the image-bearing member while applying an alternating electric field to the developer-carrying member; wherein the two-component type developer comprises a toner and a magnetic coated carrier; wherein the magnetic coated carrier comprises magnetic coated carrier particles comprising magnetic carrier core particles each comprising a binder resin and metal oxide particles, and a coating layer surface-coating each carrier core particle, wherein the metal oxide particles have been subjected to a surface lipophilicity-imparting treatment, the magnetic carrier core particles have a resistivity of at least 1x10 10 ohm.cm, the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, and the magnetic coated carrier has a particle size distribution such that (i) it has a number-average particle size Dn of 5 - 100 µm, (ii) it satisfies a relationship of Dn/σ ≧ 3.5, wherein σ denotes a standard deviation of number-basis particle size distribution of the carrier, and (iii) it contains at least 25 % by number of particles having particle sizes of at most Dn x 2/3.
Claim 85
Dependent Claim
28 words
The method according to Claim 84, wherein the alternating electric field has a peak-to-peak voltage of 500 - 5000 volts and a frequency of 500 - 10,000 Hz.
Claim 86
Dependent Claim
19 words
The method according to Claim 85, wherein the alternating electric field has a frequency of 500 - 3000 Hz.
Claim 87
Dependent Claim
26 words
The method according to Claim 84, wherein said developer-carrying member and said image-bearing member are disposed with a minimum spacing therebetween of 100 - 1000 µm.
Claim 88
Dependent Claim
23 words
The method according to Claim 84, wherein said two-component type developer is a developer according to any one of Claims 32 - 66.
Claim 89
Dependent Claim
45 words
The method according to Claim 84, wherein the developer carrying member has a surface unevenness satisfying the following conditions: 0.2 µm ≦ center line-average roughness (Ra) ≦ 5.0 µm, 10 µm ≦ average unevenness spacing (Sm) ≦ 80 µm and 0.05 ≦ Ra/Sm ≦ 0.5.
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