EP0468811A2 - Véhiculeur pour le développement d'une image électrostatique - Google Patents

Véhiculeur pour le développement d'une image électrostatique Download PDF

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Publication number
EP0468811A2
EP0468811A2 EP91306853A EP91306853A EP0468811A2 EP 0468811 A2 EP0468811 A2 EP 0468811A2 EP 91306853 A EP91306853 A EP 91306853A EP 91306853 A EP91306853 A EP 91306853A EP 0468811 A2 EP0468811 A2 EP 0468811A2
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EP
European Patent Office
Prior art keywords
particles
resin
carrier
fluorocarbon
resin particles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91306853A
Other languages
German (de)
English (en)
Other versions
EP0468811A3 (en
Inventor
Kenji Tsujita
Ken Ohmura
Shigenori Kouno
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Konica Minolta Inc
Original Assignee
Konica Minolta Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Konica Minolta Inc filed Critical Konica Minolta Inc
Publication of EP0468811A2 publication Critical patent/EP0468811A2/fr
Publication of EP0468811A3 publication Critical patent/EP0468811A3/en
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/10—Developers with toner particles characterised by carrier particles
    • G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1132—Macromolecular components of coatings
    • G03G9/1133—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/10—Developers with toner particles characterised by carrier particles
    • G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1131—Coating methods; Structure of coatings
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/10—Developers with toner particles characterised by carrier particles
    • G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1132—Macromolecular components of coatings
    • G03G9/1133—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/1134—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds containing fluorine atoms
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/10—Developers with toner particles characterised by carrier particles
    • G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1132—Macromolecular components of coatings
    • G03G9/1135—Macromolecular components of coatings obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/10—Developers with toner particles characterised by carrier particles
    • G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1132—Macromolecular components of coatings
    • G03G9/1135—Macromolecular components of coatings obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/1136—Macromolecular components of coatings obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds containing silicon atoms

Definitions

  • the present invention relates to carrier for developing electrostatic image employed in electrophotography, electrostatic recording or electrostatic printing, more specifically, to carrier for developing electrostatic image obtained by coating the surfaces of carrier core particles with resin particles by a dry method.
  • Two-component developer used in electrophotography consists of toner and carrier.
  • Carrier serves to give toner an appropriate amount of electrostatic charge of suitable polarity.
  • resin-coated carrier obtained by providing on each surface of carrier core particles a resin layer has been employed widely due to its various merits.
  • the above resin layers due to the presence of a fluorocarbon, enable carrier to have a lower surface energy, and eventually make it less subject to toner spent.
  • the provision of the above resin layers by a wet process involves such a problem that the fluorocarbon particles are unstably present in a coating composition in the form of large secondary particles which are formed by the agglomeration of fluorocarbon elementary particles that cannot be dispersed as they are due to their strong cohesiveness.
  • the poor dispersion stability of the agglomerated fluorocarbon particles makes the handling of the coating composition more difficult, and, in addition, inhibits the uniform dispersion of the fluorocarbon particles in the resin layer, and prevents the fluorocarbon particles from being in close contact with the resin particles.
  • Carrier having such resin coating layer is poor in durability. When it is employed in repeated copying, its characteristics are likely to change considerably with the lapse of time, since the fluorocarbon particles contained in the resin layers tend to be removed therefrom.
  • Carrier having the above-mentioned resin layer on its respective core particle since fluorocarbon particles are dispersed ununiformly in its outermost surface, cannot make toner uniformly charged by mutual friction due to a difference in chargeability between the fluorocarbon and the coating resin, causing such image troubles as fogging and a lowering in solid image density.
  • Japanese Patent Publication Open to Public Inspection No. 87168/1990 discloses a method of coating the surfaces of magnetic particles with resin particles by a dry process which comprises adding to magnetic particles with a weight average particle size of 10 to 200 ⁇ m resin particles of which the weight average particle size is less than 1/200 of that of the magnetic particles to form a homogeneous mixture, and giving impact repeatedly to this mixture in a mixing apparatus of which the temperature has been set at 50 to 110°C to allow the surfaces of the magnetic particles to be coated with the resin particles.
  • white powder When a large amount of white powder is present on the surface of a carrier particle, it tends to be transferred selectively to a photoreceptor during development, affecting adversely developing and cleaning conditions. That is, since white powder has a charging polarity opposite to that of toner, it selectively sticks to the non-image forming portion of a photoreceptor, and is sent to a cleaning part without being transferred. This leads to the overloading of the cleaning part, and then to insufficient cleaning. If cleaning cannot be performed sufficiently, the surface of a photoreceptor is subjected to filming. As a result, the light sensitivity of the photoreceptor is lowered, causing an image to be fogged.
  • porous resin particles with a specific BET specific surface area and a specific volume average particle size together with fluorocarbon particles resin coating efficiency can be increased drastically, the uniform dispersion of fluorocarbon particles in a resin layer can be attained to a sufficient level, and the thickness of a resin layer can be controlled freely.
  • the carrier of the invention is obtained by coating the surface of each carrier core particle with porous resin particles (secondary resin particles) which satisfy the following requirements and fluorocarbon particles:
  • porous resin particles which each comprise small-sized elementary resin particles fused on their surfaces, and have a specific BET specific surface area and a specific volume average particle size. These porous resin particles exhibit good compatibility with fluorocarbon particles, allowing a homogeneous mixture to be formed. Such uniform mixture, when applied on the surface of a carrier core particle, permits the formation of a resin coating layer in which fluorocarbon particles are quite uniformly dispersed.
  • the carrier of the invention which is obtained by coating core particles with these resin particles and fluorocarbon particles, contains an extremely small amount of white powder, and therefore, is capable of giving toner an appropriate amount of electrostatic charge.
  • the carrier of the invention can maintain its low surface energy characteristics and low resistance characteristics for a long time, and eventually has good durability.
  • the carrier of the invention in which the fluorocarbon particles are uniformly dispersed in its resin coating layer to form "composites" with the porous resin particles, can give toner an appropriate amount of charging of suitable polarity.
  • the carrier of the invention it is possible to produce repeatedly a high quality copy image free from fogging and other troubles.
  • the use of this carrier effectively prevents toner particles from flying within a copy machine.
  • the carrier of the invention can be free from toner spent.
  • carrier containing fluorocarbon particles is employed as the negative-charged carrier that makes toner charged positively, since fluorocarbon particles have strong negative chargeability.
  • the chargeability of the carrier depends on the charging characteristics of the porous resin particles, and hence, the carrier can be used also as the positive-charged carrier that gives toner negative charge.
  • the charging characteristics of the porous resin particles can be fully manifested without being affected by those of the fluorocarbon particles, and at the same time, the fluorocarbon particles can exhibit their toner spent prevention effect sufficiently.
  • the carrier of the invention comprises carrier core particles each coated with a resin coating layer.
  • the resin coating layer consists of porous resin particles and fluorocarbon particles.
  • the porous resin particles must satisfy the following requirements: (1) being composed of elementary resin particles with a volume average particle size of not more than 0.5 ⁇ m that are fused on their surfaces; (2) having a BET specific surface area of 5 to 150 m2/g;, preferably 10 to 120 m2/g;, more preferably 20 to 100 m2/g; and (3) having a volume average particle size of 1.5 to 5.0 ⁇ m.
  • the BET specific surface area is measured with, for instance, a micromeritics flow sorb (Type II2300; manufactured by Shimazu Corp).
  • the volume average particle size is measured by means of, for instance, a laser diffraction type size distribution measuring machine (HEROS; sold by Japan Electronics Corp).
  • HEROS laser diffraction type size distribution measuring machine
  • the dispersion of the porous resin particles is performed over a period of two minutes by means of a ultrasonic homogenizer with an output power of 150 W after the resin particles, a surfactant and water as a disperse medium are put in a beaker of 50 cc capacity.
  • the BET specific surface area of the porous resin particles are satisfactory when it is in the range of 5 to 150 m2/g;. Since impact power to be applied to the porous resin particles during dry coating depends on the sizes of the core particles, it is preferred that the porous resin particles have a larger BET specific surface area when the sizes of the core particles are small. If the BET specific surface area is large enough, the porous resin particles can exhibit good spreadability to the surface of the carrier core particle with minimum impact power. Meanwhile, simple, non-porous resin particles with particle sizes of about 2 ⁇ m have a BET specific surface area of smaller than 5 m2/g;.
  • the porous resin particles have a BET specific surface area smaller than 5 m2/g; they have poor spreadability to the surface of the core particle, making it difficult to obtain a coating layer of uniform thickness.
  • the porous resin particles tend to agglomerate to form white powder, which may stick to the respective particle surface of the carrier electrostatically, hindering successful development.
  • a considerable amount of the porous resin particles are present in a free state without forming a layer on the surface of the core particle, there may be a substantial lowering in resin coating efficiency.
  • volume average particle size is smaller than 1.5 ⁇ m, though spreadability is improved due to an increased BET specific area, handling of the resin particles is difficult because of their small particle sizes, and as a result, fly loss of the resin particles tends to occur, resulting in a lowered resin coating efficiency.
  • the porous resin particles have a volume average particle size exceeding 5.0 ⁇ m, their spreadability to the surface of the core particle is lowered due to the excessive agglomeration of the elementary resin particles. In this case, since the porous resin particles have a smaller BET specific surface area, and their film-forming property is so poor as will cause themselves to agglomerate to form white powder. The presence of such white powder, as mentioned before, hinders successful development.
  • the elementary resin particles that constitute the porous resin particle of the invention are small particles with a volume average particle size of not more than 0.5 ⁇ m. By the fusion of these small-sized elementary particles on their surfaces, it is possible to obtain without fail the porous resin particles with the above-defined BET specific surface area and volume average particle size. When the volume average particle size of the elementary particles exceeds 0.5 ⁇ m, the spreadability of the porous resin particles is poor since they have an extremely small BET specific surface area.
  • Resins for the elementary resin particles are not limitative.
  • resins hardly soluble in solvents are also usable. Therefore, there is a wide choice in the kind of usable resin.
  • usable resins include styrene resins, acryl resins, styrene-acryl resins, vinyl resins, ethylene resins, rosin-modified resins, polyamide resins, polyester resins, silicone resins, fluororesins and mixtures thereof. Of them, styrene-acryl resins and acryl resins are preferable.
  • a styrene-acryl resin is prepared by the copolymerization of a styrene monomer and an acryl monomer.
  • styrene monomers are styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-butylstyrene, p-t-butylstyrene, p-hexylstyrene, p-octylstyrene, p-nonylstyrene, p-decylstyrene, p-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, and mixtures thereof.
  • acryl monomers are acrylic acid and its esters such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, propyl acrylate, octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate and methyl ⁇ -chloroacrylate; methacrylic acid and its esters such as methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate;
  • the weight ratio of a styrene monomer to an acryl monomer is preferably 9:1 to 1:9.
  • the styrene component makes the resin coating layer harder, and the acryl component makes it sturdier.
  • the fluorocarbon particles used in the invention are the particles of carbon monofluoride, polydicarbon monofluoride or polytetracarbon monofluoride, which can be obtained by heating at a higher temperature a carbon source such as carbon black, crystalline graphite and petroleum coke in the presence of fluorine gas, and generally described simply as CFx, wherein x represents the content of fluorine (normally, not more than 1.2, preferably not more than 0.5).
  • CFx carbon source
  • x represents the content of fluorine (normally, not more than 1.2, preferably not more than 0.5).
  • These fluorocarbon particles can impart the carrier of the invention with a suitable level of conductivity. As a result, the specific resistance of the carrier can be in an appropriate range, allowing the carrier to have an improved developability.
  • the fluorocarbon particles are contained in the resin coating layer in a proportion of 5 to 60 wt%.
  • the fluorocarbon content exceeds 60 wt%, the fluorocarbon particles are likely to be removed from the surface of the carrier, since they cannot be dispersed sufficiently in the resin coating layer. If the fluorocarbon content is smaller than 5 wt%, the carrier has poor durability.
  • the combined amount of the porous resin particles and the fluorocarbon particles accounts for 0.3 to 5 wt% of the amount of the core particles.
  • the carrier core particles magnetic particles can be employed preferably.
  • the magnetic particles preferably have a weight average particle size of 10 to 200 ⁇ m, as measured by Microtrack Type 7981-OX (manufactured by Leeds & North Rup).
  • Substances usable as the magnetic particles include those which are strongly magnetized by a magnetic field in its direction, such as ferromagnetic metals (e.g. iron, cobalt, nickel) and alloys or compounds containing such ferromagnetic metals (e.g. ferrite, magnetite).
  • ferromagnetic metals e.g. iron, cobalt, nickel
  • alloys or compounds containing such ferromagnetic metals e.g. ferrite, magnetite
  • Ferite is a general term for iron-containing magnetic oxides, and represented by MO ⁇ Fe2O3, wherein M represents a divalent metal such as nickel, copper, zinc, manganese, magnesium and lithium.
  • the carrier of the invention can be prepared by the following method:
  • the core particles, porous resin particles and fluorocarbon particles according to the invention are mixed uniformly by means of a normal stirrer. To this mixture, impact is repeatedly given over a period of 10 to 60 minutes, preferably 15 to 30 minutes, by means of a high-speed stirring mixer of which the temperature has been set at 50 to 110°C. By this dry process, the porous resin particles and the fluorocarbon particles are allowed to stick to and spread over the surface of each core particle, thus forming a resin coating layer thereon.
  • the intensity of impact to be applied to the mixture of the porous resin particles, the core particles and the fluorocarbon particles is not limitative, as long as it is not too much to crush the core particles.
  • the film-forming properties of the porous resin particles and the fluorocarbon particles are improved by increasing impact power within such a range as will not cause the core particles to be crushed.
  • Fig. 1 shows a high-speed stirring mixer suitable for use in a dry process.
  • the upper lid 2 of a mixing chamber 1 is provided with a raw material input port 4, a filter 5 and an inspection port 6.
  • the raw material input port is equipped with an input valve 3.
  • Raw material particles are put in the chamber from the raw material input port through the input valve 3, and stirred by rotary blades 8a, 8b and 8c of a rotator 8 that rotates horizontally by a motor 7. By this, impact is given to the raw material particles.
  • this rotator consists of a central part 8d, and three rotary blades (8a, 8b and 8c) provided symmetrically with respect to the central part 8d. Each rotary blade extends obliquely from the bottom 1a of the mixing chamber. By these blades, the raw material particles are stirred upwardly. The particles then collide with the upper or lower inner wall of the chamber, and then fall down within the rotating range of the rotator blades 8a, 8b and 8c.
  • a rotator 9 that rotates vertically is provided above the rotator 8.
  • This rotator 9 has two rotator blades that rotate vertically to collide with the particles that have been rebounded from the inner wall of the chamber.
  • the rotator 9 serves to accelerate the stirring of the raw material particles and to prevent them from agglomeration.
  • the raw material particles repeatedly collide with the horizontal rotator 8, the vertical rotator 9, and the inner wall of the chamber 1, or collide with each other.
  • the raw material particles are given mechanical impact, and the porous resin particles and the fluorocarbon particles are caused to stick to the surface of each core particle to form a resin coating layer thereon.
  • the so-obtained carrier particles open a discharging valve 10, and are withdrawn from a product discharging port 11.
  • a jacket 12 serves, for example, to heat the raw material particles when they are stirred, and to cool them after stirring. It covers 3/4 of the height of the mixing chamber's outer wall (i.e. covers to a position at which the vertical rotator is provided). The mixer temperature is measured by a thermometer 13.
  • the provision of the vertical rotator is optional.
  • the carrier have a resistivity of 107 to 1014 ⁇ cm, more preferably 108 to 1012 ⁇ cm.
  • the carrier of the invention is mixed with toner to form two-component developer.
  • the kind of toner is not limitative.
  • part means “parts by weight”
  • BA means butyl acrylate
  • BMA means butyl methacrylate
  • St means styrene
  • Porous resin particles each being composed of MMA/BA (weight ratio: 75/25) copolymer particles (elementary particles) with a volume average particles size of 0.1 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 39 m2/g; and having a volume average particle size of 3.0 ⁇ m.
  • Porous resin particles each being composed of MMA/BMA (weight ratio: 70/30) copolymer particles (elementary particles) with a volume average particles size of 0.20 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 150 m2/g; and having a volume average particle size of 1.6 ⁇ m.
  • MMA/BMA weight ratio: 70/30 copolymer particles
  • Porous resin particles each being composed of MMA/BA (weight ratio: 75/25) copolymer particles (elementary particles) with a volume average particles size of 0.20 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 5 m2/g; and having a volume average particle size of 4.9 ⁇ m.
  • Porous resin particles each being composed of MMA/St (weight ratio: 60/40) copolymer particles (elementary particles) with a volume average particles size of 0.08 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 75 m2/g; and having a volume average particle size of 2.9 ⁇ m.
  • Non-porous resin particles each being composed of MMA/BMA (weight ratio: 80/20) copolymer particles (elementary particles) with a volume average particles size of 0.10 ⁇ m; and having a BET specific surface area of 65 m2/g.
  • Porous resin particles each being composed of MMA/BA (weight ratio: 75/25) copolymer particles (elementary particles) with a volume average particles size of 0.06 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 4.5 m2/g; and having a volume average particle size of 3.9 ⁇ m.
  • Porous resin particles each being composed of MMA/St (weight ratio: 70/30) copolymer particles (elementary particles) with a volume average particles size of 0.04 ⁇ m as measured upon the completion of polymerization, which are fused to each other on their surfaces; having a BET specific surface area of 10 m2/g; and having a volume average particle size of 5.1 ⁇ m.
  • the resin coating ratio is defined by the following formula:
  • Resin coating efficiency is defined by the following formula:
  • the resin coating ratio in the above formula is the value obtained by the method (1), and includes the amount of white powder (explained later).
  • the measurement of white powder transmittance is aimed at examining the amount of resin particles or agglomerates thereof that fail to form a film and electrostatically stick to and remain on the surface of a carrier particle in a free state.
  • the white powder transmittance was measured by a process comprising introducing 20 g of each carrier sample and 15 ml of methanol into a 20 ml-sample tube, stirring by a wave rotor at 46 rpm, and putting the supernatant into a cell for an electrimetric colorimeter (wavelength: 522 nm) to examine the transmittance of white powder.
  • a voltage of 100 V was applied to a 0.5-thick carrier layer (electrode area: 1 cm2, load: 1 kg). The current after 30 seconds from the beginning of the voltage application was measured, and the carrier resistivity was calculated from the value obtained.
  • Each of the above-obtained carrier samples was mixed with toner for a copying machine (Type: U-Bix, manufactured by Konica Corp) at a mixing ratio shown in Table 2, thereby to obtain two-component developer samples.
  • Dsd the distance between a development drum and a development sleeve
  • Hcut the distance between a thickness-controlling blade and a development sleeve
  • the density of the solid portion of a copy was measured by means of a Sakura densitometer (manufactured by Konica Corp) and indicated as a value relative to the density of the solid portion of an original (reflection density: 1.2). Durability was expressed in terms of the number of copies that were taken over which this relative solid image density fell below 1.0.
  • Table 2 shows that the carrier samples obtained in Examples 1 to 7 were each improved in durability and could repeatedly produce a copy image free from fogging and having a higher solid image density.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Developing Agents For Electrophotography (AREA)
EP19910306853 1990-07-27 1991-07-26 Carrier for developing electrostatic image Withdrawn EP0468811A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2197890A JPH0484143A (ja) 1990-07-27 1990-07-27 静電荷像現像用キャリア
JP197890/90 1990-07-27

Publications (2)

Publication Number Publication Date
EP0468811A2 true EP0468811A2 (fr) 1992-01-29
EP0468811A3 EP0468811A3 (en) 1992-03-18

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EP19910306853 Withdrawn EP0468811A3 (en) 1990-07-27 1991-07-26 Carrier for developing electrostatic image

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EP (1) EP0468811A3 (fr)
JP (1) JPH0484143A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2444848A1 (fr) * 2009-06-19 2012-04-25 Canon Kabushiki Kaisha Procédé de fabrication d'un support magnétique et support magnétique obtenu à l'aide de ce procédé

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2172122A1 (en) * 1972-02-14 1973-09-28 Ibm Toner carrier particles coating - used in electrostatic copiers
US3873355A (en) * 1971-01-28 1975-03-25 Ibm Coated carrier particles
EP0020181A1 (fr) * 1979-06-04 1980-12-10 Xerox Corporation Procédé de préparation de particules véhiculatrices revêtues pour des développateurs électrostatographiques
EP0132611A2 (fr) * 1983-07-25 1985-02-13 Allied Corporation Supports électrophotographiques incorporant du carbone fluoré et procédé de leur utilisation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3873355A (en) * 1971-01-28 1975-03-25 Ibm Coated carrier particles
FR2172122A1 (en) * 1972-02-14 1973-09-28 Ibm Toner carrier particles coating - used in electrostatic copiers
EP0020181A1 (fr) * 1979-06-04 1980-12-10 Xerox Corporation Procédé de préparation de particules véhiculatrices revêtues pour des développateurs électrostatographiques
EP0132611A2 (fr) * 1983-07-25 1985-02-13 Allied Corporation Supports électrophotographiques incorporant du carbone fluoré et procédé de leur utilisation

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2444848A1 (fr) * 2009-06-19 2012-04-25 Canon Kabushiki Kaisha Procédé de fabrication d'un support magnétique et support magnétique obtenu à l'aide de ce procédé
EP2444848A4 (fr) * 2009-06-19 2013-09-18 Canon Kk Procédé de fabrication d'un support magnétique et support magnétique obtenu à l'aide de ce procédé

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Publication number Publication date
EP0468811A3 (en) 1992-03-18
JPH0484143A (ja) 1992-03-17

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