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US5424810A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic toner, magnetic developer, apparatus unit, image forming apparatus and facsimile apparatus

Assignee: Canon Inc
•
Filing: 1992-09-10
•
Granted: 1995-06-13
•
Expires: 2012-09-10
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Abstract

Abstract A magnetic toner for electrophotography is composed from a binder resin and a silicon-containing magnetic iron oxide. The magnetic toner has a weigh-average particle size o at most 13.5 μm and has a particle size distribution such that it contains o more than 50 wt, % of magnetic toner particles having a particle size of at least 12.7 μm. The magnetic toner is able to show high developing performances because of richness in fine particles and is also provided with an improved environmental stability because the magnetic iron oxide used therein contains 0.5-4 wt, % silicon (based on total iron content) and has a specific silicon distribution such that the magnetic iron oxide has a total silicon content (A), a silicon content (B) dissolved together with the magnetic iron oxide when the magnetic iron oxide is dissolved up to 20 wt, % dissolution of iron, and a superficial silicon content (C), satisfying relations of B/A=44-84% and C/A=10-55%. The performances are enhanced if the magnetic toner is blended with additives such as inorganic fine powder or resin fine particles.

Inventors

  • 👤 Koichi Tomiyama
  • 👤 Hiroyuki Suematsu
  • 👤 Masayoshi Kato
  • 👤 Hiroshi Yusa
  • 👤 Takakuni Kobori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 05:50
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0831; G03G9/0834

Claims Analysis

Total Claims: 137
Claim 1
Independent Claim 160 words
A magnetic toner, comprising a binder resin and a silicon-containing magnetic iron oxide; wherein the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B) attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100 %≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 2
Dependent Claim 160 words
A magnetic toner, comprising a binder resin and a silicon-containing magnetic iron oxide; wherein the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B) attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100 %≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 3
Dependent Claim 22 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content.
Claim 4
Dependent Claim 22 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 5
Dependent Claim 17 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide satisfies a relation of 60%≦(B/A)×100%≦80%.
Claim 6
Dependent Claim 17 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide satisfies a relation of 25%≦(C/A)×100%≦40%.
Claim 7
Dependent Claim 29 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content and satisfy relations of 60%≦(B/A)×100%≦80% and 25%≦(C/A)×100%≦40%.
Claim 8
Dependent Claim 22 words
The magnetic toner according to claim 6, wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 9
Dependent Claim 20 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has an average particle size of 0.1-0.4 μm.
Claim 10
Dependent Claim 20 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has an average particle size of 0.1-0.3 μm.
Claim 11
Dependent Claim 21 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a triboelectric chargeability of -25 to -70 μC/g.
Claim 12
Dependent Claim 21 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a triboelectric chargeability of -40 to -60 μC/g.
Claim 13
Dependent Claim 22 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a volume resistivity of 5×10 3 -1×10 8 Ω.cm.
Claim 14
Dependent Claim 22 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a volume resistivity of 5×10 4 -5×10 7 Ω.cm.
Claim 15
Dependent Claim 18 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has an agglomeration degree of 3-40%.
Claim 16
Dependent Claim 18 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has an agglomeration degree of 5-30%.
Claim 17
Dependent Claim 18 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a smoothness D of 0.2-0.6.
Claim 18
Dependent Claim 18 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a smoothness D of 0.3-0.5.
Claim 19
Dependent Claim 20 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a sphericity φ of at least 0.8.
Claim 20
Dependent Claim 20 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a sphericity φ of at least 0.85.
Claim 21
Dependent Claim 20 words
The magnetic toner according to claim 1, wherein the magnetic iron oxide has a sphericity φ of at least 0.9.
Claim 22
Dependent Claim 19 words
The magnetic toner according to claim 1, wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm.
Claim 23
Dependent Claim 19 words
The magnetic toner according to claim 1, wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm.
Claim 24
Dependent Claim 39 words
The magnetic toner according to claim 1, wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 25
Dependent Claim 39 words
The magnetic toner according to claim 1, wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 26
Dependent Claim 130 words
The magnetic toner according to claim 1, wherein the magnetic toner has a weight-average particle size of 6-8 μm and has a particle size distribution such that it contains 17-60 % by number of toner particles having a particle size of at most 5 μm, 5-50% by number of toner particles having a particle size of 6.35-10.08 μm and at most 2.0% by volume of toner particles having a particle size of at least 12.7 82 m, and the amount of the toner particles having a particle size of at most 5 μm in terms of % by number (N %) and % by volume (V %) satisfy a relationship of N/V=-0.05N+k, wherein k is a positive number of 4.6 to 6.7, and N is a positive number of 17-60.
Claim 27
Dependent Claim 26 words
The magnetic toner according to claim 1, wherein 20-200 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 28
Dependent Claim 26 words
The magnetic toner according to claim 1, wherein 30-150 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 29
Dependent Claim 15 words
The magnetic toner according to claim 1, wherein the binder resin comprises a styrene copolymer.
Claim 30
Dependent Claim 15 words
The magnetic toner according to claim 1, wherein the binder resin comprises a polyester resin.
Claim 31
Dependent Claim 178 words
A magnetic developer, comprising: a magnetic toner, and inorganic fine powder, hydrophobic inorganic fine powder or resin fine particles; wherein the magnetic toner comprises a binder resin and a silicon-containing magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 32
Dependent Claim 178 words
A magnetic developer, comprising: a magnetic toner, and inorganic fine powder, hydrophobic inorganic fine powder or resin fine particles; wherein the magnetic toner comprises a binder resin and a silicon-containing magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 33
Dependent Claim 18 words
The magnetic developer according to claim 30, wherein said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder.
Claim 34
Dependent Claim 27 words
The magnetic developer according to claim 31, wherein 0.1-5 wt. parts of the hydrophobic silica fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 35
Dependent Claim 27 words
The magnetic developer according to claim 31, wherein 0.1-3 wt. parts of the hydrophobic silica fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 36
Dependent Claim 35 words
The magnetic developer according to claim 30, wherein said resin fine particles has a chargeability of a polarity which is identical in polarity to a negative chargeability or a positive chargeability of the magnetic toner.
Claim 37
Dependent Claim 20 words
The magnetic developer according to claim 34, wherein the resin fine particles have an average particle size of 0.03-2.0 μm.
Claim 38
Dependent Claim 26 words
The magnetic developer according to claim 30, wherein 0.1-5 wt. parts of the inorganic fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 39
Dependent Claim 26 words
The magnetic developer according to claim 30, wherein 0.1-3 wt. parts of the inorganic fine powder is mixed with 100 wt. parts oi the magnetic toner.
Claim 40
Dependent Claim 22 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content.
Claim 41
Dependent Claim 22 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 42
Dependent Claim 17 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide satisfies a relation of 60%≦(B/A)×100%≦80%.
Claim 43
Dependent Claim 17 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide satisfies a relation of 25%≦(C/A)×100%≦40%.
Claim 44
Dependent Claim 30 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content and satisfy relations of 60%≦(B/A)×100%≦80% and 25% ≦(C/A)×100%≦40%.
Claim 45
Dependent Claim 22 words
The magnetic developer according to claim 42, wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 46
Dependent Claim 20 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has an average particle size of 0.1-0.4 μm.
Claim 47
Dependent Claim 20 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has an average particle size of 0.1-0.3 μm.
Claim 48
Dependent Claim 21 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a triboelectric chargeability of -25 to -70 μC/g.
Claim 49
Dependent Claim 21 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a triboelectric chargeability of -40 to -60 μC/g.
Claim 50
Dependent Claim 22 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a volume resistivity of 5×10 3 -1×10 8 Ω.cm.
Claim 51
Dependent Claim 22 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a volume resistivity of 5×10 4 -5×10 7 Ω.cm.
Claim 52
Dependent Claim 18 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has an agglomeration degree of 3-40%.
Claim 53
Dependent Claim 18 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has an agglomeration degree of 5-30%.
Claim 54
Dependent Claim 18 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a smoothness D of 0.2-0.6.
Claim 55
Dependent Claim 18 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a smoothness D of 0.3-0.5.
Claim 56
Dependent Claim 20 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a sphericity φ of at least 0.8.
Claim 57
Dependent Claim 20 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a sphericity φ of at least 0.85.
Claim 58
Dependent Claim 20 words
The magnetic developer according to claim 30, wherein the magnetic iron oxide has a sphericity φ of at least 0.9.
Claim 59
Dependent Claim 19 words
The magnetic developer according to claim 30, wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm.
Claim 60
Dependent Claim 19 words
The magnetic developer according to claim 30, wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm.
Claim 61
Dependent Claim 39 words
The magnetic developer according to claim 30, wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 62
Dependent Claim 39 words
The magnetic developer according to claim 30, wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 63
Dependent Claim 128 words
The magnetic developer according to claim 30, wherein the magnetic toner has a weight-average particle size of 6-8 μm and has a particle size distribution such that it contains 17-60% by number of toner particles having a particle size of at most 5 μm, 5-50% by number of toner particles having a particle size of 6.35-10.08 μm and at most 2.0% by volume of toner particles having a particle size of at least 12.7 μm, and the amount of the toner particles having a particle size of at most 5 μm in terms of % by number (N %) and % by volume (V %) satisfy a relationship of N/V=-0.05N+k, wherein k is a positive number of 4.6 to 6.7, and N is a positive number of 17-60.
Claim 64
Dependent Claim 26 words
The magnetic developer according to claim 30, wherein 20-200 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 65
Dependent Claim 26 words
The magnetic developer according to claim 30, wherein 30-150 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 66
Dependent Claim 15 words
The magnetic developer according to claim 30, wherein the binder resin comprises a styrene copolymer.
Claim 67
Dependent Claim 15 words
The magnetic developer according to claim 30, wherein the binder resin comprises a polyester resin.
Claim 68
Independent Claim 249 words
An apparatus unit, comprising: a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member, and a regulating blade for regulating the developer carried and conveyed by the developer-carrying membe4r into a prescribed thickness to form a thin layer of the developer on the developer carrying member; wherein the developer comprising a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 69
Independent Claim 249 words
An apparatus unit, comprising: a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member, and a regulating blade for regulating the developer carried and conveyed by the developer-carrying membe4r into a prescribed thickness to form a thin layer of the developer on the developer carrying member; wherein the developer comprising a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 70
Dependent Claim 219 words
An image forming apparatus, comprising: a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, and a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member; wherein the developer comprises a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 71
Dependent Claim 219 words
An image forming apparatus, comprising: a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, and a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member; wherein the developer comprises a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 72
Dependent Claim 269 words
A facsimile apparatus, comprising: an electrophotographic apparatus and a receiving means for receiving image data from a remote terminal; wherein said electrophotographic apparatus comprises a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member, and a regulating blade for regulating the developer carried and conveyed by the developer-carrying member into a prescribed thickness to form a thin layer of the developer on the developer carrying member; wherein the developer comprises a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 73
Dependent Claim 269 words
A facsimile apparatus, comprising: an electrophotographic apparatus and a receiving means for receiving image data from a remote terminal; wherein said electrophotographic apparatus comprises a latent image-bearing member for bearing a latent image thereon and a developing apparatus for developing the latent image; the developing apparatus including a developer container for containing a developer, a developer-carrying member for carrying and conveying the developer from the developer container to a developing zone facing the latent image-bearing member, and a regulating blade for regulating the developer carried and conveyed by the developer-carrying member into a prescribed thickness to form a thin layer of the developer on the developer carrying member; wherein the developer comprises a magnetic toner comprising a binder resin and a magnetic iron oxide; the magnetic iron oxide contains 0.5-4 wt. % silicon based on total iron content, provided that the magnetic iron oxide has a total silicon content (A), a silicon content (B), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved up to 20 wt. % iron dissolution by hydrochloric acid solution or a mixture of hydrochloric acid solution and hydrofluoric acid solution and a superficial silicon content (C), attributable to siliceous compound contained in a surface layer of the magnetic iron oxide particles and dissolved by an alkali solution, satisfying relations of 44%≦(B/A)×100%≦84% and 10%≦(C/A)×100%≦55%; and the magnetic toner has a weight-average particle size of at most 13.5 μm and has a particle size distribution such that it contains no more than 50 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 74
Dependent Claim 25 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content.
Claim 75
Dependent Claim 25 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 76
Dependent Claim 20 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide satisfies a relation of 60%≦(B/A)×100%≦80%.
Claim 77
Dependent Claim 20 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide satisfies a relation of 25%≦(C/A)×100%≦40%.
Claim 78
Dependent Claim 32 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content and satisfy relations of 60%≦(B/A)×100%≦80% and 25%≦(C/A)×100%≦40%.
Claim 79
Dependent Claim 22 words
The magnetic toner according to claim 71, wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 80
Dependent Claim 23 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has an average particle size of 0.1-0.4 μm.
Claim 81
Dependent Claim 23 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has an average particle size of 0.1-0.3 μm.
Claim 82
Dependent Claim 24 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a triboelectric chargeability of -25 to -70 μC/g.
Claim 83
Dependent Claim 24 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a triboelectric chargeability of -40 to -60 μC/g.
Claim 84
Dependent Claim 25 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a volume resistivity of 5×10 3 -1×10 8 Ω.cm.
Claim 85
Dependent Claim 25 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a volume resistivity of 5×10 4 -5×10 7 Ω.cm.
Claim 86
Dependent Claim 21 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has an agglomeration degree of 3-40%.
Claim 87
Dependent Claim 21 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has an agglomeration degree of 5-30%.
Claim 88
Dependent Claim 21 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a smoothness D of 0.2-0.6.
Claim 89
Dependent Claim 21 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a smoothness D of 0.3-0.5.
Claim 90
Dependent Claim 23 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a sphericity φ of at least 0.8.
Claim 91
Dependent Claim 23 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a sphericity φ of at least 0.85.
Claim 92
Dependent Claim 23 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic iron oxide has a sphericity φ of at least 0.9.
Claim 93
Dependent Claim 22 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm.
Claim 94
Dependent Claim 22 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm.
Claim 95
Dependent Claim 42 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 96
Dependent Claim 42 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 97
Dependent Claim 132 words
The magnetic toner according to claims 66, 67 or 68 wherein the magnetic toner has a weight-average particle size of 6-8 μm and has a particle size distribution such that it contains 17-60% by number of toner particles having a particle size of at most 5 μm, 5-50% by number of toner particles having a particle size of 6.35-10.08 μm and at most 2.0% by volume of toner particles having a particle size of at least 12.7 μm, and the amount of the toner particles having a particle size of at most 5 μm in terms of % by number (N %) and % by volume (V %) satisfy a relationship of N/V=-0.05 N+k, wherein k is a positive number of 4.6 to 6.7, and N is a positive number of 17-60.
Claim 98
Dependent Claim 29 words
The magnetic toner according to claims 66, 67 or 68 wherein 20-200 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 99
Dependent Claim 29 words
The magnetic toner according to claims 66, 67 or 68 wherein 30-150 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 100
Dependent Claim 18 words
The magnetic toner according to claims 66, 67 or 68 wherein the binder resin comprises a styrene copolymer.
Claim 101
Dependent Claim 18 words
The magnetic toner according to claims 66, 67 or 68 wherein the binder resin comprises a polyester resin.
Claim 102
Dependent Claim 25 words
The magnetic developer according to claims 66, 67 or 68 which additionally includes an inorganic fine powder, hydrophobic inorganic fine powder or resin fine particles.
Claim 103
Dependent Claim 18 words
The magnetic developer according to claim 97 wherein said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder.
Claim 104
Dependent Claim 28 words
The magnetic developer according to claim 98 wherein 0.1-5 wt. % parts of the hydrophobic silica fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 105
Dependent Claim 28 words
The magnetic developer according to claim 98 wherein 0.1-3 wt. % parts of the hydrophobic silica fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 106
Dependent Claim 35 words
The magnetic developer according to claim 97 wherein said resin fine particles have a chargeability of a polarity which is identical in polarity to a negative chargeability or a positive chargeability of the magnetic toner.
Claim 107
Dependent Claim 20 words
The magnetic developer according to claim 101 wherein the resin fine particles have an average particle size of 0.03-2.0 μm.
Claim 108
Dependent Claim 26 words
The magnetic developer according to claim 97 wherein 0.1-5 wt. parts of the inorganic fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 109
Dependent Claim 26 words
The magnetic developer according to claim 97 wherein 0.1-3 wt. parts of the inorganic fine powder is mixed with 100 wt. parts of the magnetic toner.
Claim 110
Dependent Claim 22 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content.
Claim 111
Dependent Claim 22 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 112
Dependent Claim 17 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide satisfies a relation of 60%≦(B/A)×100%≦80%.
Claim 113
Dependent Claim 17 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide satisfies a relation of 25%≦(C/A)×100%≦40%.
Claim 114
Dependent Claim 29 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide contains 0.8-3.0 wt. % silicon based on total iron content and satisfy relations of 60%≦(B/A)×100%≦80% and 25%≦(C/A)×100%≦40%.
Claim 115
Dependent Claim 22 words
The magnetic developer according to claim 109 wherein the magnetic iron oxide contains 0.9-3.0 wt. % silicon based on total iron content.
Claim 116
Dependent Claim 20 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has an average particle size of 0.1-0.4 μm.
Claim 117
Dependent Claim 20 words
The magnetic developer according to claim 95 wherein the magnetic iron oxide has an average particle size of 0.1-0.3 μm.
Claim 118
Dependent Claim 21 words
The magnetic developer according to claim 95 wherein the magnetic iron oxide has a triboelectric chargeability of -25 to -70 μC/g.
Claim 119
Dependent Claim 21 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a triboelectric chargeability of -40 to -60 μC/g.
Claim 120
Dependent Claim 22 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a volume resistivity of 5×10 3 -1×10 8 Ω.cm.
Claim 121
Dependent Claim 22 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a volume resistivity of 5×10 4 -5×10 7 Ω.cm.
Claim 122
Dependent Claim 18 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has an agglomeration degree of 3-40%.
Claim 123
Dependent Claim 18 words
The magnetic developer according to claim 95 wherein the magnetic iron oxide has an agglomeration degree of 5-30%.
Claim 124
Dependent Claim 18 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a smoothness D of 0.2-0.6.
Claim 125
Dependent Claim 18 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a smoothness D of 0.3-0.5.
Claim 126
Dependent Claim 20 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a sphericity φ of at least 0.8.
Claim 127
Dependent Claim 20 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a sphericity φ of at least 0.85.
Claim 128
Dependent Claim 20 words
The magnetic developer according to claim 97 wherein the magnetic iron oxide has a sphericity φ of at least 0.9.
Claim 129
Dependent Claim 19 words
The magnetic developer according to claim 97 wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm.
Claim 130
Dependent Claim 19 words
The magnetic developer according to claim 97 wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm.
Claim 131
Dependent Claim 39 words
The magnetic developer according to claim 97 wherein the magnetic toner has a weight-average particle size of 3.5-13.5 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 132
Dependent Claim 39 words
The magnetic developer according to claim 97 wherein the magnetic toner has a weight-average particle size of 5.0-13.0 μm and contains at most 40 wt. % of magnetic toner particles having a particle size of at least 12.7 μm.
Claim 133
Dependent Claim 128 words
The magnetic toner according to claim 98, wherein the magnetic toner has a weight-average particle size of 6-8 μm and has a particle size distribution such that it contains 17-60% by number of toner particles having a particle size of at most 5 μm, 5-50% by number of toner particles having a particle size of 6.35-10.08 μm and at most 2.0% by volume of toner particles having a particle size of at least 12.7 μm, and the amount of the toner particles having a particle size of at most 5 μm in terms of % by number (N %) and % by volume (V %) satisfy a relationship of N/V=0.05N+k, wherein k is a positive number of 4.6 to 6.7, and N is a positive number of 17-60.
Claim 134
Dependent Claim 26 words
The magnetic developer according to claim 97 wherein 20-200 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 135
Dependent Claim 26 words
The magnetic developer according to claim 97 wherein 30-150 wt. parts of the magnetic iron oxide is contained per 100 wt. parts of the binder resin.
Claim 136
Dependent Claim 15 words
The magnetic developer according to claim 97 wherein the binder resin comprises a styrene copolymer.
Claim 137
Dependent Claim 15 words
The magnetic developer according to claim 95 wherein the binder resin comprises a polyester resin.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-06-12 1998-12-12 1999-06-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-06-12 2002-12-12 2003-06-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-06-12 2006-12-12 2007-06-13 $7700.00 Window Closed / Lapsed

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