EP0331393A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic toner for developing electrostatic image
Assignee: Canon Inc
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Filing: 1989-02-27
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Granted: —
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Expires: 2009-02-27
Abstract
Abstract A magnetic toner for developing electrostatic images, comprising at least a binder resin and a magnetic powder; the binder resin having 10 to 70 wt. % of a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that it provides a rate (Mw/Mn) of weight-average molecular weight (Mw)/number-average molecular weight (Mn) ≧ 5, there are a peak in the molecular weight range of 2,000 to 10,000 and a peak or shoulder in the molecular weight range of 15,000 to 100,000, and a component having a molecular weight of 10,000 or smaller is contained in an amount of 10 - 50 wt. % based on the binder resin; the magnetic powder comprising spherical magnetic particles having a bulk density of 0.6 g/ml or larger.
Inventors
- 👤 Koichi Tomiyama
- 👤 Seiichi Takagi
- 👤 Ichiro Ohsaki
- 👤 Satoshi Yasuda
- 👤 Yoshihiko Hyosu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 03:24
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0836; G03G9/0837; G03G9/087; G03G9/08784; G03G9/08793; G03G9/08795; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/104; Y10S524/00; Y10S524/901; Y10S524/904; Y10S525/00; Y10S525/934; Y10S526/00; Y10S526/934
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
136 words
A magnetic toner for developing electrostatic images, comprising at least a binder resin and a magnetic powder; said binder resin having 10 to 70 wt. % of a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that it provides a rate (Mw/Mn) of weight-average molecular weight (Mw)/number-average molecular weight (Mn) ≧ 5, there are a peak in the molecular weight range of 2,000 to 10,000 and a peak or shoulder in the molecular weight range of 15,000 to 100,000, and a component having a molecular weight of 10,000 or smaller is contained in an amount of 10 - 50 wt. % based on the binder resin; said magnetic powder comprising spherical magnetic particles having a bulk density of 0.6 g/ml or larger.
Claim 2
Dependent Claim
136 words
A magnetic toner for developing electrostatic images, comprising at least a binder resin and a magnetic powder; said binder resin having 10 to 70 wt. % of a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that it provides a rate (Mw/Mn) of weight-average molecular weight (Mw)/number-average molecular weight (Mn) ≧ 5, there are a peak in the molecular weight range of 2,000 to 10,000 and a peak or shoulder in the molecular weight range of 15,000 to 100,000, and a component having a molecular weight of 10,000 or smaller is contained in an amount of 10 - 50 wt. % based on the binder resin; said magnetic powder comprising spherical magnetic particles having a bulk density of 0.6 g/ml or larger.
Claim 3
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles have a bulk density of 0.7 g/ml or larger.
Claim 4
Dependent Claim
22 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles have a bulk density of .9 g/ml to 1.5 g/ml.
Claim 5
Dependent Claim
30 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles are contained in an amount of 40 - 200 wt. parts per 100 wt. parts of binder resin.
Claim 6
Dependent Claim
30 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles are contained in an amount of 50 - 150 wt. parts per 100 wt. parts of binder resin.
Claim 7
Dependent Claim
22 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles have an average particle size of 0.1 - 1 micron.
Claim 8
Dependent Claim
22 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles have an average particle size of 0.1 - 0.5 micron.
Claim 9
Dependent Claim
35 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles comprise 70 % by number or more of magnetic particles having a ratio of longer axis to shorter axis of 1.2 or smaller.
Claim 10
Dependent Claim
35 words
A magnetic toner according to Claim 1, wherein the spherical magnetic particles comprise 80 % by member or more of magnetic particles having a ratio of longer axis to shorter axis of 1.2 or smaller.
Claim 11
Dependent Claim
38 words
A magnetic toner according to Claim 1, wherein the THF-soluble of the binder resin contains 20 - 39 wt. % of a component having a molecular weight of 10,000 or smaller based on the weight of the THF-soluble.
Claim 12
Dependent Claim
53 words
A magnetic toner according to Claim 1, wherein the THF-soluble of the binder resin provides a molecular weight distribution in the GPC chromatogram thereof such that there are a peak in the molecular weight range of 2,000 to 10,000 and a peak or shoulder in the molecular weight range of 15,000 to 100,000.
Claim 13
Dependent Claim
22 words
A magnetic toner according to Claim 1, wherein the THF-soluble of the binder resin has a ratio (Mw/Mn) of 5 - 80.
Claim 14
Dependent Claim
22 words
A magnetic toner according to Claim 1, wherein the THF-soluble of the binder resin has a ratio (Mw/Mn) of 10 - 60.
Claim 15
Dependent Claim
20 words
A magnetic toner according to Claim 1, wherein the binder resin contains 15 - 49 wt. % of the THF-insoluble.
Claim 16
Dependent Claim
66 words
A magnetic toner according to Claim 3, wherein the THF-soluble of the binder resin provides a ratio h₁/h₂ in the range of 0.4/1 to 4.0/1 in the GPC chromatogram thereof, wherein h₁ denotes the height of the highest peak in the molecular weight range of 2,000 to 10,000, and h₂ denotes the height of the highest peak in the molecular weight range of 15,000 to 100,000.
Claim 17
Dependent Claim
15 words
A magnetic toner according to Claim 1, wherein the binder resin comprises a vinyl-type polymer.
Claim 18
Dependent Claim
21 words
A magnetic toner according to Claim 16, wherein the binder resin comprises a styrene-type polymer, styrene-type copolymer, or a mixture thereof.
Claim 19
Dependent Claim
16 words
A magnetic toner according to Claim 17, wherein the binder resin comprises a crosslinked styrene-type copolymer.
Claim 20
Dependent Claim
21 words
A magnetic toner according to Claim 17, wherein the binder resin comprises a crosslinked styrene-type polymer and a crosslinked styrene-type copolymer.
Claim 21
Dependent Claim
23 words
A magnetic toner according to Claim 17, wherein the styrene-type copolymer is a styrene-acrylic acid ester copolymer or a styrene-methacrylic acid ester copolymer.
Claim 22
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein the binder resin has a glass transition point of 40 - 80 °C.
Claim 23
Dependent Claim
14 words
A magnetic toner according to Claim 1, which further comprises a monoazo-type metal complex.
Claim 24
Dependent Claim
31 words
A magnetic toner according to Claim 22, wherein the monoazo-type metal complex is contained in an amount of 0.1 - 5 wt. parts per 100 wt. parts of the binder resin.
Claim 25
Dependent Claim
165 words
A magnetic toner obtained by mixing a binder resin and magnetic powder having a bulk density of 0.6 g/ml or larger in their powder states, thermally kneading the resultant mixture and pulverizing the kneaded product; said binder resin comprising substantially spherical particles having an average particle size of 0.1 - 7 mm or aggregates thereof; said binder resin having 10 to 70 wt. % of a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that it provides a rate (Mw/Mn) of weight-average molecular weight (Mw)/number-average molecular weight (Mn) ≧ 5, there are at least one peak in the molecular weight range of 2,000 to 10,000 and at least one peak or shoulder in the molecular weight range of 15,000 to 100,000, and a component having a molecular weight of 10,000 or smaller is contained in an amount of 10 - 50 wt. % based on the weight of the binder resin.
Claim 26
Dependent Claim
165 words
A magnetic toner obtained by mixing a binder resin and magnetic powder having a bulk density of 0.6 g/ml or larger in their powder states, thermally kneading the resultant mixture and pulverizing the kneaded product; said binder resin comprising substantially spherical particles having an average particle size of 0.1 - 7 mm or aggregates thereof; said binder resin having 10 to 70 wt. % of a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that it provides a rate (Mw/Mn) of weight-average molecular weight (Mw)/number-average molecular weight (Mn) ≧ 5, there are at least one peak in the molecular weight range of 2,000 to 10,000 and at least one peak or shoulder in the molecular weight range of 15,000 to 100,000, and a component having a molecular weight of 10,000 or smaller is contained in an amount of 10 - 50 wt. % based on the weight of the binder resin.
Claim 27
Dependent Claim
33 words
A magnetic toner for developing electrostatic images comprising a binder resin which is partly soluble in a polar organic solvent and spherical magnetic particles having a bulk density of 0.6 g/ml or above.
Claim 28
Dependent Claim
33 words
A magnetic toner for developing electrostatic images comprising a binder resin which is partly soluble in a polar organic solvent and spherical magnetic particles having a bulk density of 0.6 g/ml or above.
Claim 29
Dependent Claim
52 words
A magnetic toner for developing electrostatic images comprising magnetic particles and a binder resin made by: (a) forming a first resin by solution polymerization; (b) disolving the first resin in a polymerization monomer; and (c) suspension polymerizing the polymerizable monomer in the presence of the first resin and of a crosslinking agent.
Claim 30
Dependent Claim
52 words
A magnetic toner for developing electrostatic images comprising magnetic particles and a binder resin made by: (a) forming a first resin by solution polymerization; (b) disolving the first resin in a polymerization monomer; and (c) suspension polymerizing the polymerizable monomer in the presence of the first resin and of a crosslinking agent.
Claim 31
Dependent Claim
48 words
A magnetic toner for developing electrostatic images comprising magnetic particles and a binder resin that is partly soluble in tetrahydrofuran and that has a distribution of molecular weights showing a first peak at a relatively low molecular weight and a second peak at a relatively high molecular weight.
Claim 32
Dependent Claim
48 words
A magnetic toner for developing electrostatic images comprising magnetic particles and a binder resin that is partly soluble in tetrahydrofuran and that has a distribution of molecular weights showing a first peak at a relatively low molecular weight and a second peak at a relatively high molecular weight.
References Cited (Backward Citations)
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