EP0423743A2
Expired / Lapsed
EP
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Magnetic toner
Assignee: Canon Inc
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Filing: 1990-10-16
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Granted: —
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Expires: 2010-10-16
Abstract
Abstract A magnetic toner comprises a binder resin and a magnetic material. The magnetic toner has a volume average particle diameter of not more than 9 µm and the variation coefficient of particle size distribution, (σT/D) x 100, of the magnetic toner satisfies the following condition: 25 ≦ (σT/D) x 100 ≦ 35 where D represents a volume average particle diameter (µm) of the magnetic toner and σT represents a value of standard deviation of the volume particle size distribution of the magnetic toner, The magnetic material has a number average particle diameter of from 0.1 µm to 0.2 µm and the variation coefficient of particle size distribution, (σ/ X ) x 100, of the magnetic material satisfies the following condition: (σ/ X ) x 100 ≦ 40 where X represents a number average particle diameter (µm) of the magnetic material and σ represents a value of standard deviation of the number particle size distribution of the magnetic material.
Inventors
- 👤 Seiichi C/O Canon Kabushiki Kaisha Takagi
- 👤 Makoto C/O Canon Kabushiki Kaisha Unno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:27
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0831; G03G9/0834; G03G9/0819; G03G9/0835; G03G9/0838; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/104
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
160 words
A magnetic toner comprising a binder resin and a magnetic material, wherein; said magnetic toner has a volume average particle diameter of not more than 9 µm and the variation coefficient of particle size distribution, (σT/D) x 100, of said magnetic toner satisfies the following condition: 25 ≦ (σT/D) x 100 ≦ 35 wherein D represents a volume average particle diameter (µm) of the magnetic toner and σT represents a value of standard deviation of the volume particle size distribution of the magnetic toner; and said magnetic material has a number average particle diameter of from 0.1 µm to 0.2 µm and the variation coefficient of particle size distribution, (σ/ X ) x 100, of said magnetic material satisfies the following condition: (σ/ X ) x 100 ≦ 40 wherein X represents a number average particle diameter (µm) of the magnetic material and σ represents a value of standard deviation of the number particle size distribution of the magnetic material.
Claim 2
Dependent Claim
160 words
A magnetic toner comprising a binder resin and a magnetic material, wherein; said magnetic toner has a volume average particle diameter of not more than 9 µm and the variation coefficient of particle size distribution, (σT/D) x 100, of said magnetic toner satisfies the following condition: 25 ≦ (σT/D) x 100 ≦ 35 wherein D represents a volume average particle diameter (µm) of the magnetic toner and σT represents a value of standard deviation of the volume particle size distribution of the magnetic toner; and said magnetic material has a number average particle diameter of from 0.1 µm to 0.2 µm and the variation coefficient of particle size distribution, (σ/ X ) x 100, of said magnetic material satisfies the following condition: (σ/ X ) x 100 ≦ 40 wherein X represents a number average particle diameter (µm) of the magnetic material and σ represents a value of standard deviation of the number particle size distribution of the magnetic material.
Claim 3
Dependent Claim
34 words
A magnetic toner according to Claim 1, wherein said magnetic material is contained in an amount of from 20 to 150 parts by weight based on 100 parts by weight of said binder resin.
Claim 4
Dependent Claim
34 words
A magnetic toner according to Claim 1, wherein said magnetic material is contained in an amount of from 30 to 120 parts by weight based on 100 parts by weight of said binder resin.
Claim 5
Dependent Claim
36 words
A magnetic toner according to Claim 1, wherein said magnetic material has a number average particle diameter of from 0.14 to 0.19 µm and a variation coefficient of particle size distribution, of not more than 35.
Claim 6
Dependent Claim
36 words
A magnetic toner according to Claim 1, wherein said magnetic material has a number average particle diameter of from 0.15 to 0.19 µm and a variation coefficient of particle size distribution, of not more than 25.
Claim 7
Dependent Claim
24 words
A magnetic toner according to Claim 1, wherein said magnetic material has a variation coefficient of particle size distribution, of not more than 20.
Claim 8
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein said magnetic material has a bulk density of not less than 0.60 g/cc.
Claim 9
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein said magnetic material has a bulk density of not less than 0.70 g/cc.
Claim 10
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein said magnetic material has a bulk density of not less than 0.80 g/cc.
Claim 11
Dependent Claim
21 words
A magnetic toner according to Claim 1, wherein said magnetic material has a bulk density of not less than 0.90 g/cc.
Claim 12
Dependent Claim
20 words
A magnetic toner according to Claim 1, wherein said magnetic material is mainly comprised of magnetic particles with octahedral shape.
Claim 13
Dependent Claim
20 words
A magnetic toner according to Claim 1, wherein said magnetic material is mainly comprised of magnetic particles with spherical shape.
Claim 14
Dependent Claim
20 words
A magnetic toner according to Claim 1, wherein said magnetic material is mainly comprised of magnetic particles with hexahedral shape.
Claim 15
Dependent Claim
31 words
A magnetic toner according to Claim 1, wherein said magnetic material has a residual magnetization (σr) of from 5 to 10 emu/g when measured in a magnetic field of 1 kOe.
Claim 16
Dependent Claim
41 words
A magnetic toner according to Claim 1, wherein said magnetic material is prepared in a reaction system in which a water-soluble silicate is contained in an amount of from 0.1 to 5.0 atom % in terms of Si, based on Fe²⁺.
Claim 17
Dependent Claim
30 words
A magnetic toner according to Claim 1, wherein said magnetic material comprises magnetite particles and contains from 0.1 to 2.0 % by weight of silicon atom in terms of SiO₂.
References Cited (Backward Citations)
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