EP0801334A1
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 carrier core particles and a resinous surface coated layer coating the magnetic carrier core particles. The carrier is suitably constituted so as to satisfy the condition of: (a) the magnetic carrier core particles has a resistivity of at least 1x10 10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, (b) the magnetic coated carrier has a number-average particle size of 1- 100 µm and has such a particle size distribution that particles having particle sizes of at most a half of the number-average particle size occupy an accumulative percentage of at most 20 % by number, (c) the magnetic coated carrier has a shape factor SF-1 of 100 - 130, (d) the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/cm 3 , and (e) the resinous surface coating layer comprises a coating resin composition which in turn comprises a straight silicone resin and a coupling agent. The straight silicone resin includes trifunctional silicon and difunctional silicon in an atomic ratio of 100:0 - 40:60.
Inventors
- 👤 Yoshinobu Baba
- 👤 Yuko Sato
- 👤 Yuzo Tokunaga
- 👤 Takeshi Ikeda
- 👤 Hitoshi Itabashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 18:10
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1135; G03G9/1136; G03G9/107; G03G9/1075; G03G9/108; G03G9/1085; G03G9/1088; G03G9/10882; G03G9/10884
Claims Analysis
Total Claims: 72
Claim 1
Independent Claim
179 words
A magnetic coated carrier, comprising: magnetic coated carrier particles comprising magnetic carrier core particles and a resinous surface coating layer coating the magnetic carrier core particles, wherein (a) the magnetic carrier core particles has a resistivity of at least 1x10 10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, . (b) the magnetic coated carrier has a number-average particle size of 1 - 100 µm and has such a particle size distribution that particles having particle sizes of at most a half of the number-average particle size occupy an accumulative percentage of at most 20 % by number, (c) the magnetic coated carrier has a shape factor SF-1 of 100 - 130, (d) the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/cm 3 , and (e) the resinous surface coating layer comprises a coating resin composition which in turn comprises a straight silicone resin and a coupling agent, said straight silicone resin comprising trifunctional silicon and difunctional silicon in an atomic ratio of 100:0 - 40:60.
Claim 2
Dependent Claim
22 words
The magnetic coated carrier according to Claim 1, wherein said magnetic carrier core particles comprise a binder resin and metal oxide particles.
Claim 3
Dependent Claim
21 words
The magnetic coated carrier according to Claim 2, wherein the metal oxide particles are dispersed and contained in the binder resin.
Claim 4
Dependent Claim
30 words
The magnetic coated carrier according to Claim 3, wherein the metal oxide particles are contained in a proportion of 50 - 99 wt. % in the magnetic coated carrier particles.
Claim 5
Dependent Claim
30 words
The magnetic coated carrier according to Claim 3, wherein the metal oxide particles are contained in a proportion of 55 - 99 wt. % in the magnetic coated carrier particles.
Claim 6
Dependent Claim
32 words
The magnetic coated carrier according to Claim 3, wherein the binder resin of the magnetic carrier core particles comprises a thermosetting resin, and the metal oxide particles comprise magnetic metal oxide particles.
Claim 7
Dependent Claim
96 words
The magnetic coated carrier according to Claim 6, wherein the metal oxide particles comprise at least two species of metal oxide particles including at least one species of ferromagnetic metal oxide particles, and another species of metal oxide particles having a higher resistivity than the ferromagnetic material; said another species of metal oxide particles have number-average particle size which is larger than and at most 5 times that of the ferromagnetic metal oxide particles; and the ferromagnetic metal oxide particles occupy 30 - 95 wt. % of the total metal oxide particles in the core particles.
Claim 8
Dependent Claim
37 words
The magnetic coated carrier according to Claim 6, wherein the binder resin of the magnetic carrier core particles comprises a thermosetting resin. and has been formed by direct polymerization in the presence of the metal oxide particles.
Claim 9
Dependent Claim
16 words
The magnetic coated carrier according to Claim 8, wherein the metal oxide particles have been lipophilicity-imparted.
Claim 10
Dependent Claim
27 words
The magnetic coated carrier according to Claim 1, wherein the straight silicone resin comprises trifunctional silicon and difunctional silicon in an atomic ratio of 90:10 - 45:55.
Claim 11
Dependent Claim
32 words
The magnetic coated carrier according to Claim 1, wherein said coating resin composition contains 0.001 - 0.2 wt. part of the coupling agent per 1 wt. part of the straight silicone resin.
Claim 12
Dependent Claim
32 words
The magnetic coated carrier according to Claim 1, wherein said coating resin composition contains 0.01 - 0.1 wt. part of the coupling agent per 1 wt. Part of the straight silicone resin.
Claim 13
Dependent Claim
17 words
The magnetic coated carrier according to Claim 11, wherein said coupling agent comprises a silane coupling agent.
Claim 14
Dependent Claim
33 words
The magnetic coated carrier according to Claim 11, wherein said coupling agent comprises a mixture of a silane coupling agent having an amino group and a silane coupling agent having a hydrophobic group.
Claim 15
Dependent Claim
34 words
The magnetic coated carrier according to Claim 14, wherein the coupling agent having an amino group and the coupling agent having a hydrophobic group are mixed in a weight ratio of 10:1 to 1:10.
Claim 16
Dependent Claim
32 words
The magnetic coated carrier according to Claim 1, wherein the magnetic coated carrier particles are coated with 0.05 - 10 wt. parts of said coating resin composition per 100 wt. parts thereof.
Claim 17
Dependent Claim
59 words
The magnetic coated carrier according to Claim 1, wherein said straight silicone resin comprises an organosiloxane unit having difunctional silicon and an organosiloxane unit having tri-functional silicon of Formulae 1 and 2, respectively, shown below in combination: wherein R 1 , R 2 , R 3 and R 4 independently denote hydrogen atom, methyl group, phenyl group, or hydroxylgroup.
Claim 18
Dependent Claim
29 words
The magnetic coated carrier according to Claim 17, wherein R 1 , R 2 , R 3 .and R 4 independently denote a methyl group or a phenyl group.
Claim 19
Dependent Claim
21 words
The magnetic coated carrier according to Claim 1, wherein said coupling agent is a silane coupling agent having an amino group.
Claim 20
Dependent Claim
33 words
The magnetic coated carrier according to Claim 19, 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 21
Dependent Claim
21 words
The magnetic coated carrier according to Claim 1, wherein said coupling agent is a silane coupling agent having a hydrophobic group.
Claim 22
Dependent Claim
42 words
The magnetic coated carrier according to Claim 21, 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 23
Dependent Claim
53 words
The magnetic coated carrier according to Claim 22, 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 24
Dependent Claim
41 words
The magnetic coated carrier according to Claim 23, 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 25
Dependent Claim
39 words
The magnetic coated carrier according to Claim 22, 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 26
Dependent Claim
21 words
The magnetic coated carrier according to Claim 1, wherein said coupling agent is a silane coupling agent having an epoxy group.
Claim 27
Dependent Claim
24 words
The magnetic coated carrier according to Claim 26, wherein said coupling-agent is a compound selected from the group consisting of γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)-trimethoxysilane.
Claim 28
Dependent Claim
34 words
The magnetic coated carrier according to Claim 3, wherein the metal oxide particles are exposed to the surface of the magnetic coated carrier particles at a rate of 0.1 - 10 particles/µm 2 .
Claim 29
Dependent Claim
32 words
The magnetic coated carrier according to Claim 9, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a titanate coupling agent or a silane coupling agent having an amino group.
Claim 30
Dependent Claim
28 words
The magnetic coated carrier according to Claim 7, wherein said ferromagnetic metal oxide particles comprise magnetite particles, and said another species of metal oxide particles comprise hematite particles.
Claim 31
Dependent Claim
196 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 and a resinous surface coated layer coating the magnetic carrier core particles, wherein (a) the magnetic carrier core particles has a resistivity of at least 1x10 10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, (b) the magnetic coated carrier has a number-average particle size of 1 - 100 µm and has such a particle size distribution that particles having particle sizes of at most a half of the number-average particle size occupy an accumulative percentage of at most 20 % by number, (c) the magnetic coated carrier has a shape factor SF-1 of 100 - 130, (d) the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/cm 3 , and (e) the resinous surface coating layer comprises a coating resin composition which in turn comprises a straight silicone resin and a coupling agent, said straight silicone resin comprising trifunctional silicon and difunctional silicon in an atomic ratio of 100:0 - 40:60.
Claim 32
Dependent Claim
68 words
The developer according to Claim 31, wherein the toner has a weight-average particle size (D4) of 1 - 10 µm, contains at most 20 % by number of particles having sizes of at most a half its number-average particle size (D1), contains at most 10 % by volume of particles having sizes of at least two times D4, and has a shape factor SF-1 of 100 - 140.
Claim 33
Dependent Claim
46 words
The developer according to Claim 31, wherein said toner comprises toner particles, and an external additive added thereto comprising inorganic fine particles having a number-average particle size of at most 0.2 µm or organic fine particles having a number-average particle size of at most 0.2 µm.
Claim 34
Dependent Claim
33 words
The developer according to Claim 33, wherein said toner particles have a surface area of which 5-99 % is covered with the inorganic fine particles, the organic fine particles or a mixture thereof.
Claim 35
Dependent Claim
21 words
The developer according to Claim 33, wherein the toner particles have structure including a core and a shell coating the core.
Claim 36
Dependent Claim
23 words
The developer according to Claim 35, wherein the core comprises a low-softening point substance having a melting point of 40 - 90 °C.
Claim 37
Dependent Claim
26 words
The developer according to Claim 36, wherein the low-softening point substance is contained in a proportion of 5 - 30 wt. % in the toner particles.
Claim 38
Dependent Claim
20 words
The developer according to Claim 31, wherein said magnetic carrier core particles comprise a binder resin and metal oxide particles.
Claim 39
Dependent Claim
19 words
The developer according to Claim 38, wherein the metal oxide particles are dispersed and contained in the binder resin.
Claim 40
Dependent Claim
28 words
The developer according to Claim 39, wherein the metal oxide particles are contained in a proportion of 50 - 99 wt. % in the magnetic coated carrier particles.
Claim 41
Dependent Claim
28 words
The developer according to Claim 39, wherein the metal oxide particles are contained in a proportion of 55 - 99 wt. % in the magnetic coated carrier particles.
Claim 42
Dependent Claim
30 words
The developer according to Claim 39, wherein the binder resin of the magnetic carrier core particles comprises a thermosetting resin, and the metal oxide particles comprise magnetic metal oxide particles.
Claim 43
Dependent Claim
94 words
The developer according to Claim 42, wherein the metal oxide particles comprise at least two species of metal oxide particles including at least one species of ferromagnetic metal oxide particles, and another species of metal oxide particles having a higher resistivity than the ferromagnetic material; said another species of metal oxide particles have number-average particle size which is larger than and at most 5 times that of the ferromagnetic metal oxide particles; and the ferromagnetic metal oxide particles occupy 30 - 95 wt. % of the total metal oxide particles in the core particles.
Claim 44
Dependent Claim
35 words
The developer according to Claim 42, wherein the binder resin of the magnetic carrier core particles comprises a thermosetting resin and has been formed by direct polymerization in the presence of the metal oxide particles.
Claim 45
Dependent Claim
14 words
The developer according to Claim 44, wherein the metal oxide particles have been lipophicity-imparted.
Claim 46
Dependent Claim
25 words
The developer according to Claim 31, wherein the straight silicone resin comprises trifunctional silicon and difunctional silicon in an atomic ratio of 90:10 - 45:55.
Claim 47
Dependent Claim
30 words
The developer according to Claim 31, wherein said coating resin composition contains 0.001 - 0.2 wt. part of the coupling agent per 1 wt. part of the straight silicone resin.
Claim 48
Dependent Claim
30 words
The developer according to Claim 31, wherein said coating resin composition contains 0.01 - 0.1 wt. part of the coupling agent per 1 wt. part of the straight silicone resin.
Claim 49
Dependent Claim
15 words
The developer according to Claim 47, wherein said coupling agent comprises a silane coupling agent.
Claim 50
Dependent Claim
31 words
The developer according to Claim 47, wherein said coupling agent comprises a mixture of a silane coupling agent having an amino group and a silane coupling agent having a hydrophobic group.
Claim 51
Dependent Claim
32 words
The developer according to Claim 50, wherein the coupling agent having an amino group and the coupling agent having a hydrophobic group are mixed in a weight ratio of 10:1 to 1:10.
Claim 52
Dependent Claim
30 words
The developer according to Claim 31, wherein the magnetic coated carrier particles are coated with 0.05 - 10 wt. parts of said coating resin composition per 100 wt. parts thereof.
Claim 53
Dependent Claim
57 words
The developer according to Claim 31-, wherein said straight silicone resin comprises an organosiloxane having difunctional silicone and an organosiloxane unit having trifunctional silicone of Formulae 1 and 2, respectively, shown below in combination: wherein R 1 , R 2 , R 3 and R 4 independently denote hydrogen atom, methyl group, phenyl group, or hydroxyl group.
Claim 54
Dependent Claim
27 words
The developer according to Claim 53, wherein R 1 , R 2 , R 3 and R 4 independently denote a methyl group or a phenyl group.
Claim 55
Dependent Claim
19 words
The developer according to Claim 31, wherein said coupling agent is a silane coupling agent having an amino group.
Claim 56
Dependent Claim
33 words
The developer according to Claim 55, 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 57
Dependent Claim
19 words
The developer according to Claim 31, wherein said coupling agent is a silane coupling agent having a hydrophobic group.
Claim 58
Dependent Claim
40 words
The developer according to Claim 57, 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 59
Dependent Claim
51 words
The developer according to Claim 58, 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 60
Dependent Claim
39 words
The developer according to Claim 59, 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 61
Dependent Claim
37 words
The developer according to Claim 58, 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 62
Dependent Claim
19 words
The developer according to Claim 31, wherein said coupling agent is a silane coupling agent having an epoxy group.
Claim 63
Dependent Claim
23 words
The developer according to Claim 62, 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 64
Dependent Claim
32 words
The developer according to Claim 39, wherein the metal oxide particles are exposed to the surface of the magnetic coated carrier particles at a rate of 0.1 - 10 particles/µm 2 .
Claim 65
Dependent Claim
30 words
The developer according to Claim 45, wherein the metal oxide particles have been lipophilicity-imparted by treatment with a titanate coupling agent or a silane coupling agent having an amino group.
Claim 66
Dependent Claim
26 words
The developer according to Claim 43, wherein said ferromagnetic metal oxide particles comprise magnetite particles, and said another species of metal oxide particles comprises hematite particles.
Claim 67
Dependent Claim
253 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 and a resinous surface coated layer coating the magnetic carrier core particles, wherein (a) the magnetic carrier core particles has a resistivity of at least 1x10 10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1x10 12 ohm.cm, (b) the magnetic coated carrier has a number-average particle size of 1 - 100 µm and has such a particle size distribution that particles having particle sizes of at most a half of the number-average particle size occupy an accumulative percentage of at most 20 % by number, (c) the magnetic coated carrier has a shape factor SF-1 of 100 - 130, (d) the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40 - 250 emu/cm 3 , and (e) the resinous surface coating layer comprises a coating resin composition which in turn comprises a straight silicone resin and a coupling agent, said straight silicone resin comprising trifunctional silicon and difunctional silicon in an atomic ratio of 100:0 - 40:60.
Claim 68
Dependent Claim
28 words
The method according to Claim 67, wherein the alternating electric field has a peak-to-peak voltage of 500 - 5000 volts and a frequency of 500 - 10,000 Hz.
Claim 69
Dependent Claim
17 words
The method according to Claim 68, wherein the alternating electric field has a frequency of 500-3000 Hz.
Claim 70
Dependent Claim
26 words
The method according to Claim 67, wherein said developer-carrying member and said image-bearing member are disposed with a minimum spacing therebetween of 100 - 1000 µm.
Claim 71
Dependent Claim
23 words
The method according to Claim 67, wherein said two-component type developer is a developer according to any one of Claims 32 - 66.
Claim 72
Dependent Claim
44 words
The method according to Claim 67, 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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