WO2013129507A1 - Electrophotography carrier, and two-component developer containing same - Google Patents

Electrophotography carrier, and two-component developer containing same Download PDF

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Publication number
WO2013129507A1
WO2013129507A1 PCT/JP2013/055205 JP2013055205W WO2013129507A1 WO 2013129507 A1 WO2013129507 A1 WO 2013129507A1 JP 2013055205 W JP2013055205 W JP 2013055205W WO 2013129507 A1 WO2013129507 A1 WO 2013129507A1
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WIPO (PCT)
Prior art keywords
carrier
toner
resin
fine particles
weight
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PCT/JP2013/055205
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French (fr)
Japanese (ja)
Inventor
統 和田
加本 貴則
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シャープ株式会社
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Publication of WO2013129507A1 publication Critical patent/WO2013129507A1/en

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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00Developers
    • G03G9/08Developers with toner particles
    • G03G9/10Developers with toner particles characterised by carrier particles
    • G03G9/113Developers with toner particles characterised by carrier particles having coatings applied thereto
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00Developers
    • G03G9/08Developers with toner particles
    • G03G9/10Developers with toner particles characterised by carrier particles
    • G03G9/107Developers with toner particles characterised by carrier particles having magnetic components
    • G03G9/108Ferrite carrier, e.g. magnetite
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00Developers
    • G03G9/08Developers with toner particles
    • G03G9/10Developers with toner particles characterised by carrier particles
    • G03G9/113Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1131Coating methods; Structure of coatings
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00Developers
    • G03G9/08Developers with toner particles
    • G03G9/10Developers with toner particles characterised by carrier particles
    • G03G9/113Developers with toner particles characterised by carrier particles having coatings applied thereto
    • G03G9/1139Inorganic components of coatings

Definitions

  • the present invention relates to an electrophotographic carrier and a two-component developer including the same.
  • an image forming apparatus using an electrophotographic method a charging process in which the surface of a rotationally driven photoreceptor is uniformly charged by a charging device; the surface of the photoreceptor is irradiated with laser light by an exposure device.
  • An image is formed through a transfer step of transferring onto a transfer material (recording medium) by a transfer device; and a fixing step of fixing the toner image onto the transfer material by heating of the fixing device.
  • the transfer residual toner remaining on the surface of the photoconductor after the image forming operation is removed by a cleaning device in a cleaning process and collected in a predetermined recovery unit, and the residual charge on the surface of the photoconductor after the cleaning becomes the next image formation.
  • the charge is removed by the charge removal device in the charge removal step.
  • the developer for developing the electrostatic latent image on the surface of the photoreceptor includes a one-component developer containing only toner, and a two-component developer containing toner and an electrophotographic carrier (hereinafter also referred to as “carrier”); There is.
  • the functions of stirring, transporting and charging the toner are given by the carrier, and the toner itself does not need to have the function of the carrier, and the function can be separated between the toner and the carrier.
  • the controllability is improved as compared with the one-component developer contained in, and a high-quality image is easily obtained. For this reason, research on the toner and carrier constituting the two-component developer and the combined use has been actively conducted.
  • the carrier has two basic functions: a function of stably charging the toner to a desired charge amount and a function of transporting the toner to the photoreceptor.
  • the carrier is stirred in the developing tank, conveyed onto the magnet roller, forms a magnetic spike, passes through the regulating blade, returns to the developing tank again, and is repeatedly used. Accordingly, the carrier is required to have a stable basic function, particularly a function of stably charging the toner as it is continuously used.
  • the surface of the carrier core is made of a resin coating layer (hereinafter referred to as “resin layer” with a styrene-acrylic copolymer resin or polyurethane resin having a high surface tension or a fluororesin having a low surface tension.
  • resin layer with a styrene-acrylic copolymer resin or polyurethane resin having a high surface tension or a fluororesin having a low surface tension.
  • a resin having a high surface tension has good adhesion to the carrier core material, but there is a problem that the toner tends to be spent (consumed).
  • a resin with low surface tension is effective for toner spent, but has poor adhesion to the carrier core material.
  • the resin layer is peeled off to stabilize the charge. There is a problem that it cannot be planned.
  • JP-A-1-284862 proposes a carrier in which a carrier core material is coated with a silicone resin containing an aminosilane coupling agent in order to obtain a desired chargeability.
  • toner for example, external additives that are externally added to the toner surface has been actively performed.
  • the external additive imparts fluidity to the toner and functions as a charge amount control aid.
  • the particle size of the external additive is increased for the purpose of increasing the transfer efficiency of the toner, the contact opportunity between the toner and the carrier is hindered, and it becomes difficult to stably charge the toner.
  • the color toner has higher insulation than the monochrome toner due to its material, and it is difficult to stabilize the charging. Therefore, the carrier of Patent Document 1 has a problem that the toner cannot be sufficiently charged when the particle diameter of the external additive is increased in order to improve the transfer efficiency of the toner.
  • Patent Document 2 proposes a carrier in which a carrier core material (core particle) is coated with a resin containing nonmagnetic fine particles in order to stably charge the toner.
  • the carrier of Patent Document 2 even if the resin layer is worn by stirring with the toner, the non-magnetic fine particles serve as a spacer and the distance between the toner and the carrier core is kept constant. An increase in van der Waals force can be suppressed, and adhesion of toner to the carrier can be suppressed to maintain the charge imparting ability to the toner.
  • Patent Document 3 includes a resin layer containing conductive fine particles coated with a noble metal such as gold, platinum, and palladium, and the noble metal has a chain having an average number of connected particles of 4 or more.
  • a carrier in which a structure is formed is disclosed. According to the carrier of Patent Document 3, the ability to impart charge to the toner can be improved by forming a chain structure in the resin layer and providing a conductive path.
  • Patent Document 4 discloses a carrier in which carbon fine particles having an average particle diameter of 1 to 20 ⁇ m or carbon fine particles plated with a conductive material are contained in a resin layer. According to the carrier of Patent Document 4, the adhesion of toner to the carrier can be suppressed, and the rise of charging can be accelerated.
  • Patent Document 5 discloses a carrier in which specific metal oxide fine particles are contained in a resin layer. According to the carrier of Patent Document 5, the toner physically attached to the photoreceptor can be peeled off, and a good image can be formed.
  • JP-A-2001-22131 Patent Document 6
  • JP-A-2002-162792 Patent Document 7
  • a carrier contained in a resin layer is disclosed.
  • JP 2011-209678 A discloses a carrier in which barium sulfate fine particles are contained in a resin coating layer. According to the carrier of Patent Document 8, it is possible to suppress toner spent and to form a resin coating layer that is difficult to scrape.
  • Patent Documents 2 to 4 are insufficient in maintaining the ability to impart charge to the toner for a long period of time and cannot stably charge the toner.
  • Patent Document 5 does not describe a toner to which an external additive is externally added, and transfer efficiency becomes insufficient depending on a toner combined with a resin-coated carrier.
  • the resistance value as a carrier is lowered simply by including metal oxide fine particles, carrier adhesion is induced, and the above-described problems occur in practice.
  • the surface-treated magnetite increases the amount of charge in the initial charging stage in actual use, but the amount of charge decreases as the number of printed sheets increases, resulting in the effect of surface treatment.
  • an object of the present invention is to provide an electrophotographic carrier that has good transfer efficiency and can stably charge a toner for a long period of time, and a two-component developer including the carrier.
  • the present inventors have performed a predetermined high resistance treatment such as surface oxidation, and do not break down (conduct) under an applied voltage of 1000 V and 10 It has been found that by adding barium ferrite fine particles having a resistance value of 7 to 10 9 ⁇ ⁇ cm to the resin layer, a decrease in the charge amount can be suppressed and the above problems can be solved, and the present invention has been completed. It was.
  • the carrier core material made of ferrite and the carrier core material are coated and do not conduct as magnetic fine particles under an applied voltage of 1000 V and have a resistance value of 10 7 to 10 9 ⁇ ⁇ cm.
  • An electrophotographic carrier comprising a resin layer containing barium ferrite fine particles is provided.
  • a two-component developer comprising the above-described electrophotographic carrier and toner.
  • the present invention it is possible to provide a carrier having good transfer efficiency and capable of stably charging a toner for a long period of time and a two-component developer including the carrier. Specifically, by adding barium ferrite fine particles to the resin layer, a decrease in charge amount can be suppressed. This is because even if the resin layer peels off and the barium ferrite fine particles are exposed in the latter half of the life when the number of printed sheets is increased, the barium ferrite fine particles themselves have the charge supply performance and suppress the decrease in the charge amount to extend the life. This is thought to be due to the contribution. That is, by forming an image using the two-component developer of the present invention, a high-quality image is reproduced with high definition, good color reproducibility, high image density, and few image defects such as fog. It can be formed stably.
  • the barium ferrite fine particles have a volume average particle diameter of 0.08 to 0.8 ⁇ m, they are contained in a proportion of 0.05 to 65 parts by weight with respect to 1000 parts by weight of the carrier core material. The above effects are further exhibited.
  • the carrier of the present invention further exhibits the above effects when the resin layer further contains conductive fine particles.
  • the carrier of the present invention includes a carrier core material made of ferrite, and barium ferrite that covers the carrier core material and does not conduct as magnetic fine particles under a voltage of 1000 V and has a resistance value of 10 7 to 10 9 ⁇ ⁇ cm. And a resin layer containing fine particles (hereinafter also referred to as “Ba ferrite fine particles”).
  • “average particle size” means “volume average particle size”.
  • the resin layer covering the carrier core material contains Ba ferrite fine particles having specific physical properties, so that the toner can be stably charged over a long period of time. Therefore, by forming an image using such a two-component developer containing a carrier, the image can be reproduced with high definition, color reproducibility is good, the image density is high, and image defects such as fog are high. A quality image can be formed stably.
  • the resin layer covering the carrier core material contains a conductive agent such as carbon black instead of Ba ferrite fine particles as in the prior art
  • a conductive agent such as carbon black instead of Ba ferrite fine particles
  • the conductive agent can easily flow the electric charge between the toner and the carrier to sufficiently charge the toner.
  • the charge is depleted, that is, the carrier rises, and the toner cannot be sufficiently charged. This phenomenon becomes more prominent when the average particle diameter of the external additive externally added to the toner is increased in order to improve the transfer efficiency, and the contact between the toner and the carrier is inhibited.
  • the carrier of the present invention has optimum conductivity (conductivity), and the surface of the resin layer is scraped little by little to suppress adhesion of toner or the like to the surface, so that charging can be stabilized.
  • conductivity conductivity
  • the surface of the resin layer is scraped little by little to suppress adhesion of toner or the like to the surface, so that charging can be stabilized.
  • Ba ferrite fine particles in the resin layer it is considered that electric charge is supplied from the inside of the resin layer to the toner via the Ba ferrite fine particles, so that the average particle diameter of the external additive externally added to the toner is large.
  • the toner can be stably charged over a long period of time.
  • the Ba ferrite fine particles have a resistance value of 10 7 to 10 9 ⁇ ⁇ cm, that is, appropriate conductivity, white spots (pinholes) in an image are improved when a two-component developer is used.
  • conductive fine metal particles when conductive fine metal particles are added, the electric conduction increases as the electric field strength increases, and carrier adhesion increases due to induction charging of the carriers.
  • Ba ferrite fine particles are conductive even under a high voltage (1000 V applied voltage). Therefore, carrier adhesion can be suppressed.
  • Carrier of the present invention includes a carrier core material and a resin layer (also referred to as a “coat layer”) that includes (forms) a Ba ferrite fine particle having specific electrical characteristics as a magnetic fine particle. ).
  • Carrier core material also referred to as “core particles”
  • the carrier core material is not particularly limited as long as it is commonly used in the technical field, and examples thereof include magnetic metals such as iron, copper, nickel, and cobalt, and magnetic metal oxides such as ferrite and magnetite.
  • a carrier suitable for a developer used in the magnetic brush development method can be obtained.
  • particles containing a ferrite component are preferable. Since ferrite has a high saturation magnetization and a low density coat carrier, the use of the developer in the developer makes it difficult for the coat carrier to adhere to the photoreceptor, and a soft magnetic brush is formed, resulting in high dot reproduction. An image is obtained.
  • ferrites include zinc ferrite, nickel ferrite, copper ferrite, nickel-zinc ferrite, manganese-magnesium ferrite, copper-magnesium ferrite, manganese-zinc ferrite, manganese-copper-zinc ferrite, Examples thereof include manganese-magnesium-strontium ferrite.
  • Ferrite can be produced by a known method. For example, ferrite raw materials such as Fe 2 O 3 and Mg (OH) 2 are mixed, and this mixed powder is heated in a heating furnace and calcined. After cooling the obtained calcined product, it is pulverized by a vibration mill so as to become particles of about 1 ⁇ m, and a dispersant and water are added to the pulverized powder to prepare a slurry. The slurry is wet pulverized with a wet ball mill, and the resulting suspension is granulated and dried with a spray dryer to obtain ferrite particles.
  • ferrite raw materials such as Fe 2 O 3 and Mg (OH) 2 are mixed, and this mixed powder is heated in a heating furnace and calcined. After cooling the obtained calcined product, it is pulverized by a vibration mill so as to become particles of about 1 ⁇ m, and a dispersant and water are added to the pulverized powder to prepare a slurry. The s
  • the average particle diameter of the carrier core material is preferably 25 to 100 ⁇ m, and more preferably 25 to 90 ⁇ m. If the average particle diameter of the carrier core material is in the above range, the toner can be stably conveyed to the electrostatic latent image formed on the photoreceptor, and a high-definition image can be formed over a long period of time. it can. When the average particle size of the carrier core material is less than 25 ⁇ m, it may be difficult to control carrier adhesion. On the other hand, when the average particle diameter of the carrier core material exceeds 100 ⁇ m, a high-definition image may not be formed.
  • the resin forming the resin layer is not particularly limited as long as it is a resin commonly used in the technical field, and examples thereof include acrylic resins, acrylic-modified resins, and silicone resins. In the present invention, one of the above resins can be used alone or in combination of two or more.
  • acrylic resin examples include polyacrylate, polymethyl methacrylate, polyethyl methacrylate, poly-n-butyl methacrylate, polyglycidyl methacrylate, polyfluorinated acrylate, styrene-methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene. -Ethyl acrylate copolymer.
  • Commercially available acrylic resins include, for example, product names manufactured by Mitsubishi Rayon Co., Ltd .: Dainar SE-5437, product names manufactured by Sekisui Chemical Co., Ltd .: product names manufactured by S-LEC PSE-0020, products manufactured by Sanyo Chemical Industries, Ltd. ST95, Mitsui Chemicals product name: FM601, etc.
  • the silicone resin suppresses toner spent and can improve the adhesion between the carrier core material and the resin layer, and is preferably a cross-linked silicone resin.
  • the cross-linked silicone resin is a known silicone resin in which hydroxyl groups bonded to Si atoms or a hydroxyl group and an OX group are crosslinked and cured by a heat dehydration reaction, a room temperature curing reaction, or the like.
  • the crosslinkable silicone resin either a heat curable silicone resin or a room temperature curable silicone resin can be used.
  • the resin is heated to about 200 to 250 ° C. Further, although heating is not required to cure the room temperature curable silicone resin, it may be heated at 150 to 280 ° C. in order to shorten the curing time.
  • crosslinkable silicone resins those in which the monovalent organic group represented by R is a methyl group are preferable.
  • This cross-linked silicone resin has a fine cross-linked structure, and when this is used to form a resin layer of a carrier core material, a good carrier such as water repellency and moisture resistance can be obtained.
  • a good carrier such as water repellency and moisture resistance can be obtained.
  • the cross-linked structure becomes too dense, the resin layer tends to become brittle, so selection of the molecular weight of the cross-linked silicone resin is important.
  • the weight ratio of silicon to carbon (Si / C) in the cross-linked silicone resin is preferably 0.3 to 2.2. If Si / C is less than 0.3, the hardness of the resin layer may be reduced, and the carrier life may be reduced. On the other hand, if Si / C exceeds 2.2, the charge imparting property of the carrier to the toner is easily affected by the temperature change, and the resin layer may become brittle.
  • Examples of commercially available cross-linked silicone resins include product names manufactured by Toray Dow Corning Co., Ltd .: BA2400, BA2410, BA2411, BA2510, BA2405, 840RESIN, 804RESIN, product names manufactured by Shin-Etsu Chemical Co., Ltd .: KR350, KR271, KR272. , KR274, KR216, KR280, KR282, KR261, KR260, KR255, KR266, KR251, KR155, KR152, KR214, KR220, X-4040-171, KR201, KR5202, and KR3093.
  • the resin is preferably a silicone resin, particularly a cross-linked silicone resin, and may contain other resins as long as the preferred characteristics are not impaired.
  • other resins include epoxy resins, urethane resins, phenol resins, acrylic resins, styrene resins, polyamides, polyesters, acetal resins, polycarbonates, vinyl chloride resins, vinyl acetate resins, cellulose resins, polyolefins, and copolymers thereof.
  • Resin, compounded resin, etc. are mentioned, Among these, an acrylic resin is preferable at a point with high charge provision ability.
  • a bifunctional silicone oil may be included in order to further improve the moisture resistance, releasability, and the like of a resin layer formed of a silicone resin (particularly a cross-linked silicone resin).
  • the carrier of the present invention has a resistance value of 10 7 to 10 9 ⁇ ⁇ cm as a magnetic fine particle on the resin layer covering the carrier core material, and does not conduct under an applied voltage of 1000 V. It is characterized by containing Ba ferrite fine particles.
  • the charge imparting ability of the carrier to the toner can be further improved, the toner can be stably charged over a long period of time, and the mechanical strength of the resin layer and the adhesion of the resin layer to the carrier core material can be improved. Can be improved. Therefore, by forming an image using the two-component developer containing the carrier of the present invention, the image can be reproduced with high definition, color reproducibility is good, image density is high, and image defects such as fog are high. A quality image can be formed stably.
  • FIG. 1 is a schematic diagram of a measuring jig used for measuring the resistance value of Ba ferrite fine particles.
  • the measuring jig 1 includes a magnet 2, an aluminum electrode 3, and a base (acrylic resin plate) 4.
  • the distance between the electrodes 3 is 1 mm, and parallel plate electrodes having a size of 10 mm ⁇ 40 mm are formed.
  • the Ba ferrite fine particles ferrite fine particles of the same material as the carrier core material are used.
  • the Ba ferrite fine particles preferably have an average particle size of 0.08 to 0.8 ⁇ m, and more preferably have an average particle size of 0.2 to 0.8 ⁇ m. If the average particle diameter of the Ba ferrite fine particles is within the above range, it is possible to stably prevent the Ba ferrite fine particles from being unevenly distributed in the resin layer and between the carriers when the resin layer is formed on the surface of the carrier core material. In addition, since no irregularities are formed on the surface of the resin layer by the Ba ferrite fine particles, a uniform resin layer can be formed.
  • Ba ferrite fine particles used as a raw material do not have an appropriate average particle size, they may be subjected to pulverization or classification using a known device such as a sand mill in advance before the high resistance treatment. Good. Specific processing will be described in the embodiment.
  • the blending amount of the Ba ferrite fine particles is not particularly limited, but is preferably 0.05 to 65 parts by weight and more preferably 10 to 40 parts by weight with respect to 1000 parts by weight of the carrier core material. If the compounding quantity of Ba ferrite fine particle is said range, the outstanding effect of this invention will be exhibited. That is, the compounding amount of the Ba ferrite fine particles in the resin layer is preferably 0.05 to 65 parts by weight and more preferably 10 to 40 parts by weight with respect to 100 parts by weight of the resin. When the blending amount of the Ba ferrite fine particles is less than 0.05 parts by weight, the effect of the Ba ferrite fine particles may not be sufficiently obtained. On the other hand, when the compounding amount of the Ba ferrite fine particles exceeds 65 parts by weight, the resin layer may not be formed uniformly.
  • the resin layer preferably further contains conductive fine particles.
  • the ability of the carrier to impart charge to the toner can be more stably improved, that is, the carrier can be prevented from being charged up.
  • the conductive fine particles are not particularly limited as long as they are conductive fine particles commonly used in the technical field, and examples thereof include conductive carbon black, oxides such as conductive titanium oxide and tin oxide. Carbon black can exhibit conductivity with a small addition amount and is suitable for black toner. On the other hand, conductive titanium oxide doped with antimony is suitable for the color toner because there is a concern about the detachment of carbon black from the resin layer.
  • the blending amount of the conductive fine particles is not particularly limited, but is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the resin. If the amount of the conductive fine particles is less than 0.1 parts by weight, the effect may not be sufficiently obtained. On the other hand, if the blending amount of the conductive fine particles exceeds 30 parts by weight, the resin layer may not be formed uniformly.
  • the resin layer may further contain a coupling agent such as a silane coupling agent for the purpose of adjusting the toner charge amount.
  • the alkyl group represented by R is, for example, a straight chain or branched chain having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, and tert-butyl group.
  • examples thereof include a chain alkyl group, and among these, a methyl group and an ethyl group are preferable.
  • the alkoxy group include linear or branched alkoxy groups having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, and a tert-butoxy group.
  • a methoxy group and an ethoxy group are preferable.
  • the hydrocarbon group containing an amino group represented by Y include-(CH 2 ) a-X (wherein X is an amino group, an aminocarbonylamino group, an aminoalkylamino group, a phenylamino group or a dialkylamino group).
  • A represents an integer of 1 to 4, and -Ph-X (wherein X is the same as above, -Ph- represents a phenylene group).
  • amino group-containing silane coupling agent examples include the following. H 2 N (H 2 C) 3 Si (OCH 3 ) 3 H 2 N (H 2 C) 3 Si (OC 2 H 5 ) 3 H 2 N (H 2 C) 3 Si (CH 3 ) (OCH 3 ) 2 H 2 N (H 2 C) 2 HN (H 2 C) 3 Si (CH 3 ) (OCH 3 ) 2 H 2 NOCHN (H 2 C) 3 Si (OC 2 H 5 ) 3 H 2 N (H 2 C) 2 HN (H 2 C) 3 Si (OCH 3 ) 3 H 2 N—Ph—Si (OCH 3 ) 3 (wherein —Ph— represents a p-phenylene group) Ph-HN (H 2 C) 3 Si (OCH 3 ) 3 (wherein Ph- represents a phenyl group) (H 9 C 4 ) 2 N (H 2 C) 3 Si (OCH 3 ) 3
  • one of the above coupling agents may be used alone or in combination of two.
  • the blending amount of the coupling agent is not particularly limited, but is preferably 0.01 to 10 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the resin. When the blending amount of the coupling agent is within the above range, the toner is sufficiently charged and the mechanical strength of the resin layer is not significantly reduced.
  • Organic fine particles may further contain organic fine particles for the purpose of more stably controlling the chargeability.
  • the organic fine particles may be selected from those that do not dissolve in the solvent of the resin liquid for forming the resin layer described later. As a result, the organic fine particles can be dissolved and finely dispersed in the resin layer to avoid the expiration of the charge control function of the organic fine particles.
  • the organic fine particles include benzoguanamine resin fine particles, melamine resin fine particles, and organic fine particles containing a triazine ring. Among these, organic fine particles containing a triazine ring are preferable.
  • the average particle diameter is preferably 0.1 to 1 ⁇ m.
  • the blending amount of the organic fine particles is not particularly limited, but is preferably 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the resin. If the amount of the organic fine particles is less than 0.1 parts by weight, the effect may not be sufficiently obtained. On the other hand, if the amount of the organic fine particles exceeds 50 parts by weight, the resin layer may not be formed uniformly.
  • the carrier of the present invention is obtained by applying a resin solution in which the constituent material of the resin layer is dissolved or dispersed in a solvent to the surface of the carrier core material, and then volatilizing and removing the solvent. It can be produced by forming a coating layer and further heat-curing or simply curing the coating layer during or after drying.
  • the solvent is not particularly limited as long as it can dissolve the resin to be used.
  • aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and higher alcohols.
  • Organic solvents such as A solvent can be used individually by 1 type or in combination of 2 types.
  • a known method can be adopted.
  • a dipping method in which the carrier core material is immersed in the resin liquid a spray method in which the resin liquid is sprayed on the carrier core material, a fluidized bed method in which the resin liquid is sprayed in a state where the carrier core material is floated by flowing air, a kneader coater Among them, a kneader coater method in which a carrier core material and a resin liquid are mixed and a solvent is removed may be used.
  • the dipping method is preferable in that film formation is easy.
  • a drying accelerator may be used for drying the coating layer.
  • Known drying accelerators can be used, and examples thereof include lead such as naphthylic acid and octylic acid, metal soap such as iron, cobalt, manganese and zinc salts, and organic amines such as ethanolamine.
  • a drying accelerator can be used individually by 1 type or in combination of 2 types. The amount added is about 0.1 to 5 parts by weight per 100 parts by weight of the solvent.
  • the curing of the coating layer may be performed by appropriately setting the heating temperature according to the type of resin or solvent, for example, heating at about 150 to 280 ° C.
  • heating is not required, but it is about 150 to 280 ° C. for the purpose of improving the mechanical strength of the formed resin layer and shortening the curing time. You may heat to.
  • the film thickness of the cured resin layer is usually 5 ⁇ m or less, preferably about 0.1 to 3 ⁇ m, taking into consideration the workability of application to the carrier core material. It may be adjusted as follows.
  • the carrier thus obtained preferably has a high electrical resistance and a spherical shape, but the effect of the present invention is not lost even if it is conductive or non-spherical.
  • the two-component developer of the present invention includes the carrier of the present invention and a toner.
  • the toner will be described in the next section (3).
  • the two-component developer of the present invention can be produced by mixing the carrier of the present invention and a toner.
  • the mixing ratio of the carrier and the toner is not particularly limited, but considering that it is used in a high-speed image forming apparatus (40 sheets / min or more for A4 size images), the average particle diameter Dk of the carrier / the average particle diameter Dt of the toner is In a state of 5 or more, the ratio (St / Sk ⁇ 100) of the total projected area St (total projected area of all toner particles) of the toner to the total surface area Sk (total of the surface areas of all carrier particles) of the carrier is 30 to 70 It is preferable to mix so that it may become%.
  • the chargeability of the toner can be stably maintained in a sufficiently good state, and it can be used as a suitable two-component developer that can stably form a high-quality image for a long period of time even in a high-speed image forming apparatus.
  • the “surface area of the resin-coated carrier” can be measured as follows.
  • the average particle diameter of the carrier is measured by a particle size distribution measuring apparatus (manufactured by Nikkiso Co., Ltd., model: Microtrac MT3000), and based on this, the specific gravity of the carrier is set to 4.7, and calculation is performed from the weight of the carrier to be mixed.
  • the “projection area of toner” can be measured as follows.
  • the average particle diameter of the toner is measured by a particle size distribution measuring device (manufactured by Beckman Coulter, Inc., model: Coulter Counter Multisizer II), and based on this, the toner weight is 1.0
  • the number of toners is calculated, and the total toner area is calculated by toner number ⁇ toner area (calculated assuming a circle). From the above result, St / Sk ⁇ 100 is calculated.
  • Toner is not particularly limited as long as it is a toner commonly used in the technical field, and includes a binder resin and a colorant as essential components, and known additions such as a release agent and a charge control agent as necessary. It consists of toner base particles containing an agent, and an external additive may be added as necessary.
  • the binder resin is not particularly limited as long as it is a resin for toners commonly used in the technical field.
  • polyester resin polystyrene, styrene-acrylate copolymer resin, and the like.
  • Styrene resins acrylic resins such as polymethyl methacrylate
  • polyolefin resins such as polyethylene, polyurethane, and epoxy resins.
  • one of the above binder resins can be used alone or in combination of two or more.
  • polyester resins (hereinafter referred to as “polyester resins”) can be suitably used.
  • the polyester resin usually includes at least one selected from a divalent alcohol component and a trihydric or higher polyhydric alcohol component, and at least one selected from a divalent carboxylic acid and a trivalent or higher polyvalent carboxylic acid. It can be obtained by a polycondensation reaction, esterification or transesterification by a known method.
  • the conditions in the condensation polymerization reaction may be set as appropriate depending on the reactivity of the monomer component, and the reaction may be terminated when the polymer has suitable physical properties.
  • the reaction temperature is about 170 to 250 ° C.
  • the reaction pressure is about 5 mmHg to normal pressure.
  • divalent alcohol component examples include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxy).
  • trihydric or higher polyhydric alcohol component examples include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1 , 2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3, And 5-trihydroxymethylbenzene.
  • one of the above divalent alcohol component and trihydric or higher polyhydric alcohol component can be used alone or in combination of two or more.
  • divalent carboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malon
  • examples include acids, n-dodecenyl succinic acid, n-dodecyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, and acid anhydrides or lower alkyl esters thereof.
  • Examples of the trivalent or higher polyvalent carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, and 1,2,4-naphthalene.
  • Tricarboxylic acid 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, Examples thereof include tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, and acid anhydrides or lower alkyl esters thereof.
  • one of the above divalent carboxylic acids and trivalent or higher polyvalent carboxylic acids can be used alone or in combination of two or more.
  • the polyester resin preferably has an acid value of 5 to 30 mg KOH / g. If the acid value of the polyester resin is less than 5 mgKOH / g, the charging characteristics of the resin will be lowered, and the charge control agent will be difficult to disperse in the polyester resin, which will adversely affect the charge build-up property and the charging stability during continuous use. There is. On the other hand, when the acid value of the polyester resin exceeds 30 mgKOH / g, the hygroscopicity becomes high and the chargeability may become unstable.
  • colorant various types of organic and inorganic pigments and dyes commonly used in the technical field can be used. For example, black (black), white, yellow (Yellow), orange, red (magenta), purple, blue (cyan) and green colorants.
  • black colorant examples include inorganic pigments such as carbon black and composite oxide black; and organic pigments such as aniline black.
  • Carbon black is classified into channel black, roller black, disk black, gas furnace black, oil furnace black, thermal black, acetylene black, etc. according to its manufacturing method, etc., and from these, the design characteristics of the toner to be obtained Depending on the case, an appropriate carbon black may be appropriately selected.
  • white colorant examples include inorganic pigments such as calcium carbonate, barium sulfate, zinc oxide (zinc white), lithopone, titanium oxide, antimony white, and zinc sulfide.
  • inorganic pigments such as calcium carbonate, barium sulfate, zinc oxide (zinc white), lithopone, titanium oxide, antimony white, and zinc sulfide.
  • yellow colorants include inorganic pigments such as yellow lead, cadmium yellow, yellow iron oxide, composite oxide yellow, bismuth yellow, chrome yellow, nickel titanium yellow, and ocher; C classified by color index Pigment Yellow 1, CI Pigment Yellow 5, CI Pigment Yellow 12, CI Pigment Yellow 15, and CI Pigment Yellow 17, CI Pigment Yellow 74, C.I.
  • Organic pigments such as CI Pigment Yellow 93, CI Pigment Yellow 180 and CI Pigment Yellow 185; Nitro dyes such as CI Acid Yellow 1; CI Solvent Yellow 2 and CI Solvent Yellow 6, CI Solvent Yellow 14, CI Solvent Yellow 15, C And oil-soluble dyes such as CI Solvent Yellow 19 and CI Solvent Yellow 21.
  • Orange colorants include, for example, inorganic pigments such as red yellow lead and molybdenum orange; permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G and indanthrene brilliant orange GK, classified by color index C. I. Pigment orange 31 and C.I. I. And organic pigments such as CI Pigment Orange 43.
  • red (magenta) colorants examples include inorganic pigments such as Bengala, cadmium red, red lead, mercury sulfide, and molybdenum red; CI Pigment Red 49 and CI Pigment Red classified by color index. 57, CI Pigment Red 81, CI Pigment Red 122, CI Solvent Red 19, CI Solvent Red 49, CI Solvent Red 52, CI Basic Red 10 and And organic pigments such as CI Disperse Red 15.
  • purple colorants include inorganic pigments such as manganese purple; organic pigments such as fast violet B and methyl violet lake.
  • blue (cyan) colorant examples include, for example, inorganic pigments such as bitumen and cobalt blue; CI pigment blue 15, CI pigment blue 16, and CI solvent classified by color index. Blue 55, CI Solvent Blue 70, CI Direct Blue 25, CI Direct Blue 86 and KET. And organic pigments such as BLUE111.
  • green colorant examples include inorganic pigments such as chrome green and chrome oxide; final green green G and C. which are classified by pigment green B, micalite green lake, and color index. I. And organic pigments such as CI Pigment Green 7.
  • a pigment is preferable as a colorant because the pigment is excellent in light resistance and color developability as compared with a dye, and a toner excellent in light resistance and color developability can be obtained.
  • one of the above colorants may be used alone or in combination of two, and these combinations may be different colors or the same color.
  • Two or more colorants may be used as composite particles.
  • the composite particles can be produced, for example, by adding an appropriate amount of water, lower alcohol or the like to two or more colorants, granulating with a general granulator such as a high speed mill, and drying. Further, in order to uniformly disperse the colorant in the binder resin, a master batch may be used. The composite particles and the master batch are mixed into the toner composition during dry mixing.
  • the binder resin and the colorant are dry-mixed with a mixer, the obtained powder mixture is kneaded with a kneader, and the obtained kneaded product is pulverized to, for example, a particle size of about 2 mm to 3 mm.
  • the binder resin the same kind as that of the toner binder resin or a resin having good compatibility with the toner binder resin is used.
  • the mixing ratio of the binder resin and the colorant is not particularly limited, but the colorant is about 30 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
  • a known apparatus commonly used in the technical field can be used.
  • Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd. (currently Nihon Coke Industries)
  • super mixer trade name
  • Henshell type mixing devices such as Mechanomyl (trade name, manufactured by Okada Seiko Co., Ltd.), Ongmill (trade name, manufactured by Hosokawa Micron Corporation), Hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.) )
  • Cosmo system trade name, manufactured by Kawasaki Heavy Industries, Ltd.
  • melt-kneading of the masterbatch known apparatuses commonly used in the technical field can be used, such as a single-screw, twin-screw or multi-screw extruder (extruder), a kneader, two or three roll mills, a lab blast mill, etc.
  • extruder twin-screw or multi-screw extruder
  • kneader two or three roll mills
  • lab blast mill etc.
  • the following general kneaders may be mentioned. Specifically, TEM-100B (model, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of these models, manufactured by Ikegai Co., Ltd.), etc. Examples thereof include open roll type kneaders such as trade name, Mitsui Mining Co., Ltd.
  • the kneading temperature depends on conditions such as the softening temperature of the binder resin, but is usually about 50 to 150 ° C, preferably about 50 to 120 ° C. Other melt kneading conditions may be appropriately set depending on the kneader to be used, the master batch raw material, and the like.
  • the blending amount of the colorant is not particularly limited, but is preferably 5 to 20 parts by weight, and more preferably 5 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
  • the amount of the masterbatch used may be adjusted so that the blending amount of the colorant is within the above range.
  • an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
  • release agents commonly used in the art can be used, for example, petroleum wax such as paraffin wax and microcrystalline wax and derivatives thereof; Fischer-Tropsch wax, polyolefin wax (polyethylene wax, Hydrocarbon waxes such as polypropylene wax), low molecular weight polypropylin wax and polyolefin polymer wax (such as low molecular weight polyethylene wax) and derivatives thereof; carnauba wax, rice wax and candelilla wax and derivatives thereof, wood wax Plant waxes such as beeswax, animal waxes such as beeswax and spermaceti; oils and fats synthetic waxes such as fatty acid amides and phenol fatty acid esters; long chain carboxylic acids and derivatives thereof Body; long-chain alcohols and derivatives thereof; silicone polymer; such as higher fatty acids.
  • petroleum wax such as paraffin wax and microcrystalline wax and derivatives thereof
  • Fischer-Tropsch wax polyolefin wax (polyethylene wax, Hydrocarbon waxes such
  • Derivatives include oxides, block copolymers of vinyl monomers and waxes, graft modified products of vinyl monomers and waxes, and the like.
  • 1 type of said mold release agent can be used individually or in combination of 2 or more types.
  • the release agent is preferably a hydrocarbon release agent. Moreover, it is preferable that the melting
  • the compounding amount of the release agent is not particularly limited, but is preferably 0.2 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. When the amount of the release agent is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
  • Charge control agent also referred to as “charge control agent” or “charge control agent”
  • charge control agents for positive charge control and negative charge control that are commonly used in the art can be used.
  • Examples of the charge control agent for positive charge control include nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, triphenylmethane. Derivatives, guanidine salts, amidine salts and the like can be mentioned.
  • Examples of charge control agents for controlling negative charges include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, naphthenic acid metal salts, metal complexes and metal salts of salicylic acid and its derivatives ( Examples of the metal include chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, and resin acid soaps. Among these, boron compounds are particularly preferable because they do not contain heavy metals.
  • one of the above charge control agents may be used alone or in combination of two or more.
  • the blending amount of the charge control agent is not particularly limited, but is preferably 0.5 to 3 parts by weight, particularly preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the binder resin. If the blending amount of the charge control agent is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
  • Toner manufacturing method The toner is a known method such as a general toner production method, for example, a dry method such as a pulverization method, a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsion method. Can be produced.
  • a dry method such as a pulverization method, a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsion method.
  • the pulverization method is particularly preferable in that the number of steps is small and the amount of capital investment is small as compared with the wet method.
  • a toner material containing at least a binder resin, a colorant and a release agent, and optionally a charge control agent is mixed and melt-kneaded to obtain a kneaded product, and then the kneaded product is cooled, solidified and pulverized. Thereafter, particle size adjustment such as classification is performed as necessary to obtain toner particles.
  • a known apparatus can be used for each step of mixing, melt-kneading, pulverization, and classification.
  • External additive an external additive commonly used in the technical field can be used, and examples thereof include silica, titanium oxide, silicon carbide, aluminum oxide, barium titanate and the like. Those that have been surface treated (hydrophobized) with a silicone resin, a silane coupling agent or the like are preferred. In the present invention, one of the above external additives may be used alone or in combination of two or more.
  • a plurality of external additives having different average particle diameters in combination.
  • at least one of the plurality of external additives has an average particle diameter of 0.1 ⁇ m or more, and the average particle diameter of the plurality of external additives is 0.2 ⁇ m or less.
  • the smaller one has an average particle diameter of 0.007 to 0.5 ⁇ m, and the larger one has an average particle diameter of 0.5 to 0.2 ⁇ m.
  • the ratio of the smaller average particle diameter to the larger average particle diameter is preferably 1: 5 to 1:20.
  • the amount of the external additive added is not particularly limited, but is preferably 0.1 to 3.0 parts by weight, particularly preferably 0.3 to 2 parts by weight, based on 100 parts by weight of the toner base particles.
  • amount of the external additive is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
  • the image forming method using the two-component developer of the present invention comprises a step of forming a latent image on the image carrier and a latent image formed on the image carrier using the two-component developer. Including a step of developing and forming a toner image, and is excellent in image reproducibility including color reproducibility, and can form a high-definition and high-image density image stably and for a long time.
  • Coating resin 100 parts by weight of 20% toluene solution of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR350) (20 parts by weight of resin), Magnetic fine particles: Ba ferrite fine particles (average particle diameter 0.8 ⁇ m, resistance value 10 8 ⁇ ⁇ cm, not conducting even under 1000 V applied voltage) 30 parts by weight
  • Conductive fine particles conductive carbon black toluene dispersion (solid concentration 15%, 5 parts by weight manufactured by Cabot Corporation, product name: VULCAN XC72
  • Coupling agent silane coupling agent (100% solution, manufactured by Toray Dow Corning Co., Ltd., product name: SH6020) 4 parts by weight
  • Solvent 100 parts by weight of toluene
  • the mixture containing the above components was stirred for 5 minutes at a rotational speed of 500 rpm using a general-purpose stirrer (manufactured by Shinto Kagaku Co., Ltd., model: Three-One Motor BLh1200) to prepare a coating resin solution.
  • 1000 parts by weight of a carrier core material (Mn—Mg ferrite) having an average particle diameter of 35 ⁇ m was added to and mixed with the obtained coating resin liquid, and further mixed for 5 minutes at a rotation speed of 500 rpm using the above stirrer.
  • the obtained mixture was depressurized (about 6.0 ⁇ 10 4 Pa) and heated (about 100 ° C.) to remove the toluene solvent, thereby forming a coating layer on the surface of the carrier core material.
  • the obtained carrier core material having the coating layer is heated at 200 ° C. for 1 hour using a safety oven (manufactured by ESPEC Corporation, model: SPH (H) 102) to cure the coating layer to form a resin layer. Then, it was passed through a 100 mesh screen to obtain about 2000 g of resin-coated carrier (1) (30 parts by weight of magnetic fine particles with respect to 1000 parts by weight of carrier core material). Table 1 shows each component of the resin-coated carrier 1 and the blending amount thereof.
  • Resin-coated carriers 2 to 15 were obtained in the same manner as the resin-coated carrier 1, except that the respective components of the resin-coated carrier shown in Table 1 and their blending amounts were used. Only in the case of the resin-coated carrier 2, an acrylic resin (styrene-methyl methacrylate copolymer, copolymerization ratio 20:80, molecular weight 85) instead of a 20% toluene solution of a silicone resin (indicated as (R1) in Table 1). , 000, (indicated as (R2) in Table 1) 20% toluene solution.
  • an acrylic resin styrene-methyl methacrylate copolymer, copolymerization ratio 20:80, molecular weight 85
  • Ba ferrite fine particles (average particle size 0.8 ⁇ m, expressed as (B1) in Table 1) as magnetic fine particles
  • Ba ferrite fine particles ((B2) to (Denoted as (B5)) was used.
  • the Ba ferrite fine particles (B1) to (B5) do not conduct even under an applied voltage of 1000V.
  • Table 1 shows the components of the resin-coated carriers 2 to 15 and their blending amounts.
  • toner 1 Binder resin: Polyester resin (acid value 21 mgKOH / g, aromatic alcohol component: PO-BPA and EP-BPA, acid component: fumaric acid and merit anhydride) 87.5 parts by weight Colorant: C.I. I. Pigment Blue 15: 1 5 parts by weight Mold release agent: nonpolar paraffin wax, melting point 78 ° C., weight average molecular weight: Mw832) 6 parts by weight Charge control agent: negatively charged salicylic acid compound 1.5 parts by weight
  • the above components are premixed for 5 minutes using a Henschel mixer and then melt kneaded using a twin screw extruder at a cylinder setting temperature of 110 ° C., a barrel rotation speed of 300 rpm, and a raw material supply speed of 20 kg / hour. Got.
  • the obtained melt-kneaded product is cooled by a cooling belt, it is coarsely pulverized using a cutting mill, then finely pulverized using a jet type pulverizer, and further classified using an air classifier. 2000 g of toner particles having a diameter of 6.5 ⁇ m were obtained.
  • toner particles were subjected to a hydrophobic treatment with 1.2% by weight of silica fine particles (average particle size 100 nm) hydrophobized with i-butyltrimethoxysilane and hexamethyldisilazane (HMDS).
  • silica fine particles average particle diameter: 12 nm
  • the silica fine particles were added in an amount of 1.0% by weight and mixed using a Henschel mixer to obtain 2000 g of toner 1 (cyan toner).
  • Example 2 to 14 and Comparative Example 1 Two-component developers of Examples 2 to 14 and Comparative Examples 1 and 2 were obtained and evaluated in the same manner as in Example 1 except that the toner shown in Table 2 was combined with the resin-coated carrier.
  • the charge amount ( ⁇ C / g) was measured in the same manner for the two-component developer obtained in the same manner except that the stirring time was 1 minute. From the absolute value of the difference in charge amount between the obtained stirring time of 1 minute and 3 minutes, the charge rising characteristics were evaluated according to the following criteria. ⁇ : Good (charge difference is 5 ⁇ C / g or less) ⁇ : Acceptable (Charge amount difference exceeds 5 ⁇ C / g and 10 ⁇ C / g or less) X: Defect (charge amount difference exceeds 10 ⁇ C / g)
  • a two-component developer is set in a commercially available copying machine (manufactured by Sharp Corporation, model: MX-6000N) having a two-component developing device remodeled for measurement. The image density of the image area, the whiteness of the non-image area, and the charge amount of the two-component developer were measured.
  • Image Density was measured using a spectrocolorimetric densitometer (manufactured by Nihon Himeki Kaisha, Ltd., model: X-Rite 938), and evaluated according to the following criteria. ⁇ : Good (image density is 1.4 or more) X: Defect (image density is less than 1.4)
  • Carrier adhesion A two-component developer was set in the copying machine, and the number of carriers adhered in a fixed area (297 mm ⁇ 24 mm) in the non-image area on the image carrier was counted. At this time, a DC bias voltage of 200 V, an AC bias voltage of 1100 V, and a frequency of 9 kHz were applied to the developer carrier, and the surface of the image carrier was not charged. Carrier adhesion was evaluated from the obtained carrier adhesion number according to the following criteria. ⁇ : Good (number of carriers attached is less than 15) ⁇ : Possible (Number of carriers attached is 15 or more and 20 or less) X: Defect (number of carriers attached exceeds 20)
  • Image quality A two-component developer is set in the above-mentioned copying machine, an image test chart is printed, and a granularity score value when the color difference from white is 30, 50, and 70 is calculated using an automatic printer image quality evaluation system ( Measurement was performed using Oji Scientific Instruments Co., Ltd., model: APQS). The image quality (granularity) was evaluated from the maximum score value obtained according to the following criteria. Note that the lower the score value, the less the roughness of the image and the higher the image quality. ⁇ (good): Maximum score value is less than 11500 ⁇ (possible): Maximum score value is 11500 or more and 12000 or less ⁇ (Poor): Maximum score value is more than 12000
  • the toners (Examples 1 to 14) containing the carrier of the present invention have good chargeability, carrier adhesion, image quality, and coating state of the resin layer, particularly life characteristics.
  • the toner containing a carrier containing no Ba ferrite fine particles in the resin layer (Comparative Example 1) is inferior in chargeability, carrier adhesion, image quality, and coating state of the resin layer, particularly in life characteristics.

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Abstract

An electrophotography carrier characterized by being configured from: a carrier core material formed from a ferrite; and a resin layer for covering the carrier core material and containing barium ferrite fine particles as magnetic fine particles, the barium ferrite fine particles not exhibiting conductivity at a voltage application lower than 1000V and having a resistance value between 107 and 109 Ω∙cm.

Description

電子写真用キャリアおよびそれを含む2成分現像剤Electrophotographic carrier and two-component developer containing the same
 本発明は、電子写真用キャリアおよびそれを含む2成分現像剤に関する。 The present invention relates to an electrophotographic carrier and a two-component developer including the same.
 近年、OA機器の目覚しい発達に伴い、電子写真方式を利用した複写機、プリンタ、ファクシミリ装置などの画像形成装置が広く普及している。 In recent years, with the remarkable development of OA equipment, image forming apparatuses such as copying machines, printers, and facsimile machines using an electrophotographic system have been widely spread.
 電子写真方式を利用した画像形成装置では、通常、回転駆動する感光体の表面を帯電装置により均一に帯電する帯電工程;帯電した感光体表面に露光装置によりレーザ光を照射して、感光体表面に静電潜像を形成する露光工程;感光体表面の静電潜像を現像装置によりトナーを用いて現像して、感光体表面にトナー像を形成する現像工程;感光体表面のトナー像を転写装置により転写材(記録媒体)上に転写する転写工程;および定着装置の加熱によりトナー像を転写材上に定着する定着工程を経て画像が形成される。
 そして、画像形成動作後に感光体表面上に残留した転写残留トナーは、クリーニング工程においてクリーニング装置により除去されて所定の回収部に回収され、クリーニング後の感光体表面における残留電荷は、次の画像形成に備えるために、除電工程において除電装置により除電される。
In an image forming apparatus using an electrophotographic method, a charging process in which the surface of a rotationally driven photoreceptor is uniformly charged by a charging device; the surface of the photoreceptor is irradiated with laser light by an exposure device. An exposure step for forming an electrostatic latent image on the surface; a development step for developing the electrostatic latent image on the surface of the photoconductor with toner using a developing device to form a toner image on the surface of the photoconductor; and a toner image on the surface of the photoconductor An image is formed through a transfer step of transferring onto a transfer material (recording medium) by a transfer device; and a fixing step of fixing the toner image onto the transfer material by heating of the fixing device.
Then, the transfer residual toner remaining on the surface of the photoconductor after the image forming operation is removed by a cleaning device in a cleaning process and collected in a predetermined recovery unit, and the residual charge on the surface of the photoconductor after the cleaning becomes the next image formation. In order to prepare for this, the charge is removed by the charge removal device in the charge removal step.
 感光体表面の静電潜像を現像するための現像剤には、トナーのみを含む1成分現像剤と、トナーと電子写真用キャリア(以下「キャリア」ともいう)とを含む2成分現像剤とがある。
 2成分現像剤は、キャリアにより、トナーの撹拌、搬送および帯電という機能が付与され、トナー自体がキャリアの機能を併せもつ必要がなく、トナーとキャリアとで機能を分離できるので、トナーのみを単独で含む1成分現像剤よりも制御性が向上し、高画質画像が得られ易いという特徴を有する。このため、2成分現像剤を構成するトナーおよびキャリアならびに併用に関する研究が盛んに行われている。
The developer for developing the electrostatic latent image on the surface of the photoreceptor includes a one-component developer containing only toner, and a two-component developer containing toner and an electrophotographic carrier (hereinafter also referred to as “carrier”); There is.
In the two-component developer, the functions of stirring, transporting and charging the toner are given by the carrier, and the toner itself does not need to have the function of the carrier, and the function can be separated between the toner and the carrier. The controllability is improved as compared with the one-component developer contained in, and a high-quality image is easily obtained. For this reason, research on the toner and carrier constituting the two-component developer and the combined use has been actively conducted.
 キャリアは、トナーを所望の帯電量に安定して帯電させる機能と、トナーを感光体に搬送する機能という2つの基本機能を有する。キャリアは、現像槽内で撹拌され、マグネットローラー上に搬送され、磁気穂を形成して規制ブレードを通過して再び現像槽内に戻り、繰り返し使用される。したがって、キャリアには、継続して使用される中で、安定した基本機能、特に安定的にトナーを帯電させる機能が求められる。 The carrier has two basic functions: a function of stably charging the toner to a desired charge amount and a function of transporting the toner to the photoreceptor. The carrier is stirred in the developing tank, conveyed onto the magnet roller, forms a magnetic spike, passes through the regulating blade, returns to the developing tank again, and is repeatedly used. Accordingly, the carrier is required to have a stable basic function, particularly a function of stably charging the toner as it is continuously used.
 キャリアの基本機能を維持するために、例えば、キャリア芯材表面を、表面張力の高いスチレン-アクリル共重合体樹脂やポリウレタン樹脂で、または表面張力の低いフッ素樹脂で樹脂被覆層(以下「樹脂層」ともいう)を形成する方法が提案されている。
 しかしながら、表面張力の高い樹脂では、キャリア芯材との密着性は良好であるが、トナーがスペント(消耗)し易いという問題がある。また、表面張力の低い樹脂では、トナースペントに対しては有効であるが、キャリア芯材との密着性に劣り、キャリアを現像槽内で撹拌すると、樹脂層が剥れて帯電の安定化が図れないという問題がある。
In order to maintain the basic function of the carrier, for example, the surface of the carrier core is made of a resin coating layer (hereinafter referred to as “resin layer” with a styrene-acrylic copolymer resin or polyurethane resin having a high surface tension or a fluororesin having a low surface tension. Is also proposed.
However, a resin having a high surface tension has good adhesion to the carrier core material, but there is a problem that the toner tends to be spent (consumed). A resin with low surface tension is effective for toner spent, but has poor adhesion to the carrier core material. When the carrier is stirred in the developing tank, the resin layer is peeled off to stabilize the charge. There is a problem that it cannot be planned.
 そこで、特開平1-284862号公報(特許文献1)では、所望の帯電性を得るために、アミノシランカップリング剤を含有するシリコーン樹脂でキャリア芯材を被覆したキャリアが提案されている。
 他方、近年では電子写真のフルカラー化が進み、それに伴ってトナーの改良、例えば、トナー表面に外添させる外添剤の改良も盛んに行われている。外添剤は、トナーに流動性を付与すると共に、帯電量のコントロール助剤として機能する。
 フルカラー化において、トナーの転写効率を高める目的で外添剤の粒子径を大きくすると、トナーとキャリアとの接触機会が阻害され、トナーを安定的に帯電させることが困難になる。また、カラートナーは、その材料に起因して、モノクロトナーに比べて絶縁性が高く、帯電を安定化させることが困難である。
 したがって、特許文献1のキャリアは、トナーの転写効率を向上させるために外添剤の粒子径を大きくすると、トナーを充分に帯電させることができないという問題がある。
In view of this, JP-A-1-284862 (Patent Document 1) proposes a carrier in which a carrier core material is coated with a silicone resin containing an aminosilane coupling agent in order to obtain a desired chargeability.
On the other hand, in recent years, full-color electrophotography has progressed, and accordingly, improvement of toner, for example, external additives that are externally added to the toner surface has been actively performed. The external additive imparts fluidity to the toner and functions as a charge amount control aid.
In full color, when the particle size of the external additive is increased for the purpose of increasing the transfer efficiency of the toner, the contact opportunity between the toner and the carrier is hindered, and it becomes difficult to stably charge the toner. Further, the color toner has higher insulation than the monochrome toner due to its material, and it is difficult to stabilize the charging.
Therefore, the carrier of Patent Document 1 has a problem that the toner cannot be sufficiently charged when the particle diameter of the external additive is increased in order to improve the transfer efficiency of the toner.
 そこで、特開2007-121911号公報(特許文献2)では、トナーを安定して帯電させるために、非磁性微粒子を含有する樹脂でキャリア芯材(コア粒子)を被覆したキャリアが提案されている。特許文献2のキャリアによれば、樹脂層がトナーとの撹拌により摩耗しても、非磁性微粒子がスペーサーの役割を果たしてトナーとキャリア芯材との距離が一定に保たれるので、両者間のファンデルワールス力の増大を抑制でき、トナーのキャリアへの付着を抑制してトナーへの帯電付与能力を維持することができる。 In view of this, Japanese Patent Application Laid-Open No. 2007-121911 (Patent Document 2) proposes a carrier in which a carrier core material (core particle) is coated with a resin containing nonmagnetic fine particles in order to stably charge the toner. . According to the carrier of Patent Document 2, even if the resin layer is worn by stirring with the toner, the non-magnetic fine particles serve as a spacer and the distance between the toner and the carrier core is kept constant. An increase in van der Waals force can be suppressed, and adhesion of toner to the carrier can be suppressed to maintain the charge imparting ability to the toner.
 また、特開2009-93135号公報(特許文献3)には、樹脂層に金、白金、パラジウムなどの貴金属でコートした導電性微粒子を含有させ、その貴金属により平均連結粒子数4個以上の連鎖状構造体を形成させたキャリアが開示されている。特許文献3のキャリアによれば、樹脂層に連鎖状構造体を形成して導電経路を設けることにより、トナーへの帯電付与能力を向上させることができる。 Japanese Patent Application Laid-Open No. 2009-93135 (Patent Document 3) includes a resin layer containing conductive fine particles coated with a noble metal such as gold, platinum, and palladium, and the noble metal has a chain having an average number of connected particles of 4 or more. A carrier in which a structure is formed is disclosed. According to the carrier of Patent Document 3, the ability to impart charge to the toner can be improved by forming a chain structure in the resin layer and providing a conductive path.
 また、特開平10-333363号公報(特許文献4)には、平均粒径1~20μmの炭素微粒子または導電性材料でメッキ処理された炭素微粒子を樹脂層に含有させたキャリアが開示されている。特許文献4のキャリアによれば、トナーのキャリアへの付着を抑制でき、帯電の立ち上がりを速くすることができる。 Japanese Patent Application Laid-Open No. 10-333363 (Patent Document 4) discloses a carrier in which carbon fine particles having an average particle diameter of 1 to 20 μm or carbon fine particles plated with a conductive material are contained in a resin layer. . According to the carrier of Patent Document 4, the adhesion of toner to the carrier can be suppressed, and the rise of charging can be accelerated.
 さらに、特開昭61-296363号公報(特許文献5)には、特定の金属酸化物微粒子を樹脂層に含有させたキャリアが開示されている。特許文献5のキャリアによれば、感光体に物理的に付着したトナーを剥離することができ、良好な画像を形成することができる。 Furthermore, Japanese Patent Application Laid-Open No. 61-296363 (Patent Document 5) discloses a carrier in which specific metal oxide fine particles are contained in a resin layer. According to the carrier of Patent Document 5, the toner physically attached to the photoreceptor can be peeled off, and a good image can be formed.
 また、特開2001-22131号公報(特許文献6)および特開2002-162792号公報(特許文献7)には、3級アミン化合物やシランカップリング剤、シリコーンオイルなどで表面処理されたマグネタイトを樹脂層に含有させたキャリアが開示されている。 JP-A-2001-22131 (Patent Document 6) and JP-A-2002-162792 (Patent Document 7) describe a magnetite surface-treated with a tertiary amine compound, a silane coupling agent, silicone oil or the like. A carrier contained in a resin layer is disclosed.
 また、特開2011-209678号公報(特許文献8)には、樹脂被覆層中に硫酸バリウム微粒子を含有させたキャリアが開示されている。特許文献8のキャリアによれば、トナースペントを抑制し、削れ難い樹脂被覆層を形成させることができる。 Further, JP 2011-209678 A (Patent Document 8) discloses a carrier in which barium sulfate fine particles are contained in a resin coating layer. According to the carrier of Patent Document 8, it is possible to suppress toner spent and to form a resin coating layer that is difficult to scrape.
特開平1-284862号公報JP-A-1-284862 特開2007-121911号公報JP 2007-121911 A 特開2009-93135号公報JP 2009-93135 A 特開平10-333363号公報JP 10-333363 A 特開昭61-296363号公報JP 61-296363 A 特開2001-22131号公報Japanese Patent Laid-Open No. 2001-22131 特開2002-162792号公報JP 2002-162792 A 特開2011-209678号公報JP 2011-209678 A
 しかしながら、特許文献2~4の樹脂被覆キャリアでは、長期間にわたるトナーへの帯電付与能力の維持が不充分であり、トナーを安定して帯電させることができない。
 また、特許文献5には、外添剤が外添されたトナーについての記載がなく、樹脂被覆キャリアと組合せるトナーによっては転写効率が不充分になる。さらには、単に金属酸化物微粒子を含むだけではキャリアとしての抵抗値が下がるため、キャリア付着を誘発し、実用上、上記のような課題が生じることになる。
 さらに、特許文献6および7の樹脂被覆キャリアでは、表面処理されたマグネタイトにより、実使用上の帯電初期における帯電量は高くなるが、印字枚数が増加すると帯電量が低下して、表面処理した効果が事実上なくなるという問題がある。これは、マグネタイト粒子自体の抵抗値が低いために、マグネタイト粒子自体が電荷のリークポイントとして働くためと推察される。
 また、印字枚数が増加すると樹脂層が剥離して、キャリア芯材が露出し、帯電量が低下するという問題があった。
 さらに、特許文献8の樹脂被覆キャリアでは、実施例にて使用している導電性硫酸バリウム微粒子の抵抗値がコート樹脂、キャリア芯材に対し低いため、長期の使用において硫酸バリウムが露出し、キャリア抵抗値の低下によるキャリア付着の誘発と、電荷のリークポイントが形成されることによる帯電の低下が懸念される。
However, the resin-coated carriers of Patent Documents 2 to 4 are insufficient in maintaining the ability to impart charge to the toner for a long period of time and cannot stably charge the toner.
Further, Patent Document 5 does not describe a toner to which an external additive is externally added, and transfer efficiency becomes insufficient depending on a toner combined with a resin-coated carrier. Furthermore, since the resistance value as a carrier is lowered simply by including metal oxide fine particles, carrier adhesion is induced, and the above-described problems occur in practice.
Furthermore, in the resin-coated carriers of Patent Documents 6 and 7, the surface-treated magnetite increases the amount of charge in the initial charging stage in actual use, but the amount of charge decreases as the number of printed sheets increases, resulting in the effect of surface treatment. There is a problem that is virtually eliminated. This is presumably because the magnetite particles themselves act as charge leak points because the resistance of the magnetite particles themselves is low.
Further, when the number of printed sheets increases, the resin layer is peeled off, the carrier core material is exposed, and there is a problem that the charge amount is lowered.
Furthermore, in the resin-coated carrier of Patent Document 8, since the resistance value of the conductive barium sulfate fine particles used in the examples is lower than that of the coating resin and the carrier core material, barium sulfate is exposed in a long-term use. There are concerns about induction of carrier adhesion due to a decrease in resistance value and a decrease in charging due to the formation of charge leakage points.
 したがって、本発明は、転写効率が良好で、長期間にわたってトナーを安定して帯電させることができる電子写真用キャリアおよびそれを含む2成分現像剤を提供することを課題とする。 Therefore, an object of the present invention is to provide an electrophotographic carrier that has good transfer efficiency and can stably charge a toner for a long period of time, and a two-component developer including the carrier.
 本発明者らは、上記の課題を解決するために鋭意研究を行った結果、表面酸化のような所定の高抵抗化処理を行った、1000V印加電圧下でもブレイクダウン(導通)せずかつ107~109Ω・cmの抵抗値を有するバリウムフェライト微粒子を樹脂層に添加することにより、帯電量の低下を抑えることができ、上記の課題を解決できることを見出し、本発明を完成するに到った。 As a result of intensive studies to solve the above-mentioned problems, the present inventors have performed a predetermined high resistance treatment such as surface oxidation, and do not break down (conduct) under an applied voltage of 1000 V and 10 It has been found that by adding barium ferrite fine particles having a resistance value of 7 to 10 9 Ω · cm to the resin layer, a decrease in the charge amount can be suppressed and the above problems can be solved, and the present invention has been completed. It was.
 かくして、本発明によれば、フェライトからなるキャリア芯材と、前記キャリア芯材を被覆し、かつ磁性微粒子として1000V印加電圧下で導通せずかつ107~109Ω・cmの抵抗値を有するバリウムフェライト微粒子を含む樹脂層とで構成されることを特徴とする電子写真用キャリアが提供される。 Thus, according to the present invention, the carrier core material made of ferrite and the carrier core material are coated and do not conduct as magnetic fine particles under an applied voltage of 1000 V and have a resistance value of 10 7 to 10 9 Ω · cm. An electrophotographic carrier comprising a resin layer containing barium ferrite fine particles is provided.
 また、本発明によれば、上記の電子写真用キャリアとトナーとを含むことを特徴とする2成分現像剤が提供される。 Further, according to the present invention, there is provided a two-component developer comprising the above-described electrophotographic carrier and toner.
 本発明によれば、転写効率が良好で、長期間にわたってトナーを安定して帯電させることができるキャリアおよびそれを含む2成分現像剤を提供することができる。
 具体的には、バリウムフェライト微粒子を樹脂層に添加することにより、帯電量の低下を抑えることができる。
 これは、印字枚数が増加したライフ後半に樹脂層が剥離してバリウムフェライト微粒子が露出しても、バリウムフェライト微粒子自体が電荷供給性能を有し、帯電量の低下を抑制してロングライフ化に寄与することによるものと考えられる。
 すなわち、本発明の2成分現像剤を用いて画像を形成することにより、画像を高精細に再現し、色再現性が良好でかつ画像濃度が高く、かぶりなどの画像欠陥の少ない高画質画像を安定して形成することができる。
According to the present invention, it is possible to provide a carrier having good transfer efficiency and capable of stably charging a toner for a long period of time and a two-component developer including the carrier.
Specifically, by adding barium ferrite fine particles to the resin layer, a decrease in charge amount can be suppressed.
This is because even if the resin layer peels off and the barium ferrite fine particles are exposed in the latter half of the life when the number of printed sheets is increased, the barium ferrite fine particles themselves have the charge supply performance and suppress the decrease in the charge amount to extend the life. This is thought to be due to the contribution.
That is, by forming an image using the two-component developer of the present invention, a high-quality image is reproduced with high definition, good color reproducibility, high image density, and few image defects such as fog. It can be formed stably.
 本発明のキャリアは、バリウムフェライト微粒子が0.08~0.8μmの体積平均粒子径を有することにより、キャリア芯材1000重量部に対して0.05~65重量部の割合で含まれることにより、上記の効果がさらに発揮される。
 また、本発明のキャリアは、樹脂層が導電性微粒子をさらに含むことにより、上記の効果がさらに発揮される。
In the carrier of the present invention, since the barium ferrite fine particles have a volume average particle diameter of 0.08 to 0.8 μm, they are contained in a proportion of 0.05 to 65 parts by weight with respect to 1000 parts by weight of the carrier core material. The above effects are further exhibited.
In addition, the carrier of the present invention further exhibits the above effects when the resin layer further contains conductive fine particles.
バリウムフェライト微粒子の抵抗値測定に用いる測定冶具の模式図である。It is a schematic diagram of the measuring jig used for resistance value measurement of barium ferrite fine particles.
 本発明のキャリアは、フェライトからなるキャリア芯材と、前記キャリア芯材を被覆し、かつ磁性微粒子として1000V印加電圧下で導通せずかつ107~109Ω・cmの抵抗値を有するバリウムフェライト微粒子(以下「Baフェライト微粒子」ともいう)を含む樹脂層とで構成されることを特徴とする。
 本明細書において、特に断わりのない限り「平均粒子径」は「体積平均粒子径」を意味する。
The carrier of the present invention includes a carrier core material made of ferrite, and barium ferrite that covers the carrier core material and does not conduct as magnetic fine particles under a voltage of 1000 V and has a resistance value of 10 7 to 10 9 Ω · cm. And a resin layer containing fine particles (hereinafter also referred to as “Ba ferrite fine particles”).
In this specification, unless otherwise specified, “average particle size” means “volume average particle size”.
 本発明のキャリアは、キャリア芯材を被覆する樹脂層が特定の物性を有するBaフェライト微粒子を含むことにより、長期間にわたりトナーを安定して帯電させることができる。したがって、このようなキャリアを含む2成分現像剤を用いて画像を形成することにより、画像を高精細に再現し、色再現性が良好でかつ画像濃度が高く、かぶりなどの画像欠陥の少ない高画質画像を安定して形成することができる。 In the carrier of the present invention, the resin layer covering the carrier core material contains Ba ferrite fine particles having specific physical properties, so that the toner can be stably charged over a long period of time. Therefore, by forming an image using such a two-component developer containing a carrier, the image can be reproduced with high definition, color reproducibility is good, the image density is high, and image defects such as fog are high. A quality image can be formed stably.
 従来技術のように、キャリア芯材を被覆する樹脂層がBaフェライト微粒子の代わりに、カーボンブラックのような導電剤を含むキャリアでは、これを絶縁性の高いカラートナーと2成分現像剤とした場合の初期には、導電剤がトナーとキャリアとの間の電荷を流れ易くしてトナーを充分に帯電させることができる。しかしながら、印刷枚数が増加する、すなわちキャリア表面のトナーが入れ替わると、電荷が枯渇して、つまりキャリア上がりが生じて、トナーを充分に帯電させることができなくなる。この現象は、転写効率を向上させるためにトナーに外添する外添剤の平均粒子径を大きくすると、トナーとキャリアとの接触が阻害され、より顕著に表れる。 In the case where the resin layer covering the carrier core material contains a conductive agent such as carbon black instead of Ba ferrite fine particles as in the prior art, when this is a highly insulating color toner and a two-component developer In the initial stage, the conductive agent can easily flow the electric charge between the toner and the carrier to sufficiently charge the toner. However, when the number of printed sheets increases, that is, when the toner on the carrier surface is replaced, the charge is depleted, that is, the carrier rises, and the toner cannot be sufficiently charged. This phenomenon becomes more prominent when the average particle diameter of the external additive externally added to the toner is increased in order to improve the transfer efficiency, and the contact between the toner and the carrier is inhibited.
 一方、本発明のキャリアは、導通性(導電性)が最適であり、樹脂層表面を少しずつ削り表面にトナーなどの付着を抑制するので、帯電を安定化させることができる。
 Baフェライト微粒子を樹脂層に含有させることにより、樹脂層内部からBaフェライト微粒子を介して電荷がトナーに供給されるものと考えられるので、トナーに外添された外添剤の平均粒子径が大きくても、長期間にわたってトナーを安定して帯電させることができる。
 また、Baフェライト微粒子が107~109Ω・cmの抵抗値、すなわち適度な導通性を有することにより、2成分現像剤とした場合に画像の白抜け(ピンホール)が改善される。
 さらに、通常、導電性の金属微粒子を添加すると電界強度が強くなるにしたがって導通し、キャリアが誘導帯電することによりキャリア付着が多くなるが、Baフェライト微粒子は高電圧(1000V印加電圧)下でも導通しないため、キャリア付着を抑制することができる。
On the other hand, the carrier of the present invention has optimum conductivity (conductivity), and the surface of the resin layer is scraped little by little to suppress adhesion of toner or the like to the surface, so that charging can be stabilized.
By including Ba ferrite fine particles in the resin layer, it is considered that electric charge is supplied from the inside of the resin layer to the toner via the Ba ferrite fine particles, so that the average particle diameter of the external additive externally added to the toner is large. However, the toner can be stably charged over a long period of time.
Further, since the Ba ferrite fine particles have a resistance value of 10 7 to 10 9 Ω · cm, that is, appropriate conductivity, white spots (pinholes) in an image are improved when a two-component developer is used.
In addition, when conductive fine metal particles are added, the electric conduction increases as the electric field strength increases, and carrier adhesion increases due to induction charging of the carriers. However, Ba ferrite fine particles are conductive even under a high voltage (1000 V applied voltage). Therefore, carrier adhesion can be suppressed.
 以下、(1)キャリア、(2)2成分現像剤、(3)トナーおよび(4)画像形成方法の項目に分けて説明する。本発明の特徴であるBaフェライト微粒子については、(1)キャリアの(1-3)Baフェライト微粒子の項目で詳述する。 Hereinafter, the description will be divided into items of (1) carrier, (2) two-component developer, (3) toner, and (4) image forming method. The Ba ferrite fine particles that are the characteristics of the present invention will be described in detail in the section of (1) carrier (1-3) Ba ferrite fine particles.
(1)キャリア
 本発明のキャリアは、キャリア芯材と、その表面を被覆する(形成される)、磁性微粒子として特定の電気的特性を有するBaフェライト微粒子を含む樹脂層(「コート層」ともいう)とで構成される。
(1) Carrier The carrier of the present invention includes a carrier core material and a resin layer (also referred to as a “coat layer”) that includes (forms) a Ba ferrite fine particle having specific electrical characteristics as a magnetic fine particle. ).
(1-1)キャリア芯材(「コア粒子」ともいう)
 キャリア芯材としては、当該技術分野で常用されるものであれば特に限定されず、例えば、鉄、銅、ニッケル、コバルトなどの磁性金属、フェライト、マグネタイトなどの磁性金属酸化物などが挙げられる。これらのキャリア芯材であれば、磁気ブラシ現像法に用いる現像剤に好適なキャリアが得られる。
 これらの中でも、フェライト成分を含む粒子が好ましい。フェライトは、飽和磁化が高く、密度の小さいコートキャリアを得ることができるので、現像剤におけるその使用により、感光体へのコートキャリア付着が起こり難く、ソフトな磁気ブラシが形成されてドット再現の高い画像が得られる。
(1-1) Carrier core material (also referred to as “core particles”)
The carrier core material is not particularly limited as long as it is commonly used in the technical field, and examples thereof include magnetic metals such as iron, copper, nickel, and cobalt, and magnetic metal oxides such as ferrite and magnetite. With these carrier core materials, a carrier suitable for a developer used in the magnetic brush development method can be obtained.
Among these, particles containing a ferrite component are preferable. Since ferrite has a high saturation magnetization and a low density coat carrier, the use of the developer in the developer makes it difficult for the coat carrier to adhere to the photoreceptor, and a soft magnetic brush is formed, resulting in high dot reproduction. An image is obtained.
 フェライトとしては、例えば、亜鉛系フェライト、ニッケル系フェライト、銅系フェライト、ニッケル-亜鉛系フェライト、マンガン-マグネシウム系フェライト、銅-マグネシウム系フェライト、マンガン-亜鉛系フェライト、マンガン-銅-亜鉛系フェライト、マンガン-マグネシウム-ストロンチウム系フェライトなどが挙げられる。 Examples of ferrites include zinc ferrite, nickel ferrite, copper ferrite, nickel-zinc ferrite, manganese-magnesium ferrite, copper-magnesium ferrite, manganese-zinc ferrite, manganese-copper-zinc ferrite, Examples thereof include manganese-magnesium-strontium ferrite.
 フェライトは、公知の方法で作製できる。例えば、Fe23やMg(OH)2などのフェライト原料を混合し、この混合粉を加熱炉で加熱して仮焼する。得られた仮焼品を冷却後、振動ミルでほぼ1μm程度の粒子となるように粉砕し、粉砕粉に分散剤と水を加えてスラリーを作製する。このスラリーを湿式ボールミルで湿式粉砕し、得られる懸濁液をスプレードライヤーで造粒乾燥することによって、フェライトの粒子が得られる。 Ferrite can be produced by a known method. For example, ferrite raw materials such as Fe 2 O 3 and Mg (OH) 2 are mixed, and this mixed powder is heated in a heating furnace and calcined. After cooling the obtained calcined product, it is pulverized by a vibration mill so as to become particles of about 1 μm, and a dispersant and water are added to the pulverized powder to prepare a slurry. The slurry is wet pulverized with a wet ball mill, and the resulting suspension is granulated and dried with a spray dryer to obtain ferrite particles.
 キャリア芯材の平均粒子径は、25~100μmであるのが好ましく、25~90μmであるのがより好ましい。
 キャリア芯材の平均粒子径が上記の範囲であれば、感光体に形成された静電潜像にトナーを安定して搬送することができると共に、長期間にわたって高精細な画像を形成することができる。
 キャリア芯材の平均粒子径が25μm未満では、キャリア付着のコントロールが困難になることある。一方、キャリア芯材の平均粒子径が100μmを超えると、高精細な画像を形成できないことがある。
The average particle diameter of the carrier core material is preferably 25 to 100 μm, and more preferably 25 to 90 μm.
If the average particle diameter of the carrier core material is in the above range, the toner can be stably conveyed to the electrostatic latent image formed on the photoreceptor, and a high-definition image can be formed over a long period of time. it can.
When the average particle size of the carrier core material is less than 25 μm, it may be difficult to control carrier adhesion. On the other hand, when the average particle diameter of the carrier core material exceeds 100 μm, a high-definition image may not be formed.
(1-2)樹脂
 樹脂層を形成する樹脂としては、当該技術分野で常用される樹脂であれば特に限定されず、例えば、アクリル樹脂、アクリル変性樹脂、シリコーン樹脂などが挙げられる。
 本発明においては、上記の樹脂の1種を単独でまたは2種以上を組み合わせて用いることができる。
(1-2) Resin The resin forming the resin layer is not particularly limited as long as it is a resin commonly used in the technical field, and examples thereof include acrylic resins, acrylic-modified resins, and silicone resins.
In the present invention, one of the above resins can be used alone or in combination of two or more.
 アクリル樹脂としては、例えば、ポリアクリレート、ポリメチルメタクリレート、ポリエチルメタクリレート、ポリ-n-ブチルメタクリレート、ポリグリシジルメタクリレート、ポリ含フッ素アクリレート、スチレン-メタクリレート共重合体、スチレン-ブチルメタクリレート共重合体、スチレン-アクリル酸エチル共重合体などが挙げられる。
 市販のアクリル樹脂としては、例えば、三菱レイヨン株式会社製の製品名:ダイヤナールSE-5437、積水化学工業株式会社製の製品名:エスレックPSE-0020、三洋化成工業株式会社製の製品名:ハイマーST95、三井化学株式会社製の製品名:FM601などが挙げられる。
Examples of the acrylic resin include polyacrylate, polymethyl methacrylate, polyethyl methacrylate, poly-n-butyl methacrylate, polyglycidyl methacrylate, polyfluorinated acrylate, styrene-methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene. -Ethyl acrylate copolymer.
Commercially available acrylic resins include, for example, product names manufactured by Mitsubishi Rayon Co., Ltd .: Dainar SE-5437, product names manufactured by Sekisui Chemical Co., Ltd .: product names manufactured by S-LEC PSE-0020, products manufactured by Sanyo Chemical Industries, Ltd. ST95, Mitsui Chemicals product name: FM601, etc.
 シリコーン樹脂は、トナースペントを抑制すると共に、キャリア芯材と樹脂層との密着性を良好にすることができ、架橋型シリコーン樹脂が好ましい。
 架橋型シリコーン樹脂は、下記に示すように、Si原子に結合する水酸基同士または水酸基とOX基とが加熱脱水反応、常温硬化反応などによって架橋して硬化する公知のシリコーン樹脂である。
The silicone resin suppresses toner spent and can improve the adhesion between the carrier core material and the resin layer, and is preferably a cross-linked silicone resin.
As shown below, the cross-linked silicone resin is a known silicone resin in which hydroxyl groups bonded to Si atoms or a hydroxyl group and an OX group are crosslinked and cured by a heat dehydration reaction, a room temperature curing reaction, or the like.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
(式中、複数のRは同一または異なって1価の有機基を示し、基OXはアセトキシ基、アミノキシ基、アルコキシ基、オキシム基などを示す) (In the formula, plural Rs are the same or different and represent a monovalent organic group, and the group OX represents an acetoxy group, an aminoxy group, an alkoxy group, an oxime group, etc.)
 架橋型シリコーン樹脂としては、加熱硬化型シリコーン樹脂、常温硬化型シリコーン樹脂のいずれをも使用できる。加熱硬化型シリコーン樹脂を架橋させるには、該樹脂を200~250℃程度に加熱する。また、常温硬化型シリコーン樹脂を硬化させるには、加熱を必要としないが、硬化時間の短縮のために150~280℃で加熱してもよい。 As the crosslinkable silicone resin, either a heat curable silicone resin or a room temperature curable silicone resin can be used. In order to crosslink the thermosetting silicone resin, the resin is heated to about 200 to 250 ° C. Further, although heating is not required to cure the room temperature curable silicone resin, it may be heated at 150 to 280 ° C. in order to shorten the curing time.
 架橋型シリコーン樹脂の中でも、Rで示される1価の有機基がメチル基であるものが好ましい。この架橋型シリコーン樹脂は架橋構造が緻密であり、これを用いてキャリア芯材の樹脂層を形成すると、撥水性、耐湿性などの良好なキャリアが得られる。但し、架橋構造が緻密になり過ぎると、樹脂層が脆くなる傾向があるので、架橋型シリコーン樹脂の分子量の選択が重要である。 Among the crosslinkable silicone resins, those in which the monovalent organic group represented by R is a methyl group are preferable. This cross-linked silicone resin has a fine cross-linked structure, and when this is used to form a resin layer of a carrier core material, a good carrier such as water repellency and moisture resistance can be obtained. However, if the cross-linked structure becomes too dense, the resin layer tends to become brittle, so selection of the molecular weight of the cross-linked silicone resin is important.
 また、架橋型シリコーン樹脂中の珪素と炭素の重量比(Si/C)は、0.3~2.2であるのが好ましい。
 Si/Cが0.3未満では、樹脂層の硬度が低下し、キャリア寿命などが低下することがある。一方、Si/Cが2.2を超えると、キャリアのトナーに対する電荷付与性が温度変化による影響を受け易くなり、樹脂層が脆化することがある。
The weight ratio of silicon to carbon (Si / C) in the cross-linked silicone resin is preferably 0.3 to 2.2.
If Si / C is less than 0.3, the hardness of the resin layer may be reduced, and the carrier life may be reduced. On the other hand, if Si / C exceeds 2.2, the charge imparting property of the carrier to the toner is easily affected by the temperature change, and the resin layer may become brittle.
 市販の架橋型シリコーン樹脂としては、例えば、東レダウコーニング株式会社製の製品名:BA2400、BA2410、BA2411、BA2510、BA2405、840RESIN、804RESIN、信越化学工業株式会社製の製品名:KR350、KR271、KR272、KR274、KR216、KR280、KR282、KR261、KR260、KR255、KR266、KR251、KR155、KR152、KR214、KR220、X-4040-171、KR201、KR5202、KR3093などが挙げられる。 Examples of commercially available cross-linked silicone resins include product names manufactured by Toray Dow Corning Co., Ltd .: BA2400, BA2410, BA2411, BA2510, BA2405, 840RESIN, 804RESIN, product names manufactured by Shin-Etsu Chemical Co., Ltd .: KR350, KR271, KR272. , KR274, KR216, KR280, KR282, KR261, KR260, KR255, KR266, KR251, KR155, KR152, KR214, KR220, X-4040-171, KR201, KR5202, and KR3093.
 樹脂としては、シリコーン樹脂、特に架橋型シリコーン樹脂が好ましく、その好ましい特性を損なわない範囲で他の樹脂を含んでもよい。
 他の樹脂としては、例えば、エポキシ樹脂、ウレタン樹脂、フェノール樹脂、アクリル樹脂、スチレン樹脂、ポリアミド、ポリエステル、アセタール樹脂、ポリカーボネート、塩化ビニル樹脂、酢酸ビニル樹脂、セルロース樹脂、ポリオレフィン、これらの共重合体樹脂、配合樹脂などが挙げられ、これらの中でも、帯電付与能力が高い点でアクリル樹脂が好ましい。例えば、シリコーン樹脂(特に架橋型シリコーン樹脂)により形成される樹脂層の耐湿性、離型性などをさらに向上させるために、二官能性シリコーンオイルを含んでいてもよい。
The resin is preferably a silicone resin, particularly a cross-linked silicone resin, and may contain other resins as long as the preferred characteristics are not impaired.
Examples of other resins include epoxy resins, urethane resins, phenol resins, acrylic resins, styrene resins, polyamides, polyesters, acetal resins, polycarbonates, vinyl chloride resins, vinyl acetate resins, cellulose resins, polyolefins, and copolymers thereof. Resin, compounded resin, etc. are mentioned, Among these, an acrylic resin is preferable at a point with high charge provision ability. For example, a bifunctional silicone oil may be included in order to further improve the moisture resistance, releasability, and the like of a resin layer formed of a silicone resin (particularly a cross-linked silicone resin).
(1-3)Baフェライト微粒子
 本発明のキャリアは、キャリア芯材を被覆する樹脂層に、磁性微粒子として、1000V印加電圧下で導通せずかつ107~109Ω・cmの抵抗値を有するBaフェライト微粒子を含むことを特徴とする。
 これにより、キャリアのトナーへの帯電付与能力を一層向上させることができ、長期間にわたってトナーを安定して帯電させることができ、樹脂層の機械的強度およびキャリア芯材に対する樹脂層の密着性を向上させることができる。
 したがって、本発明のキャリアを含む2成分現像剤を用いて画像を形成することにより、画像を高精細に再現し、色再現性が良好でかつ画像濃度が高く、かぶりなどの画像欠陥の少ない高画質画像を安定して形成することができる。
(1-3) Ba Ferrite Fine Particles The carrier of the present invention has a resistance value of 10 7 to 10 9 Ω · cm as a magnetic fine particle on the resin layer covering the carrier core material, and does not conduct under an applied voltage of 1000 V. It is characterized by containing Ba ferrite fine particles.
Thereby, the charge imparting ability of the carrier to the toner can be further improved, the toner can be stably charged over a long period of time, and the mechanical strength of the resin layer and the adhesion of the resin layer to the carrier core material can be improved. Can be improved.
Therefore, by forming an image using the two-component developer containing the carrier of the present invention, the image can be reproduced with high definition, color reproducibility is good, image density is high, and image defects such as fog are high. A quality image can be formed stably.
 Baフェライト微粒子の1000V/cmの電界下における体積抵抗値は、図1に示すような測定冶具によって測定することができる。
 図1は、Baフェライト微粒子の抵抗値測定に用いる測定冶具の模式図である。
 測定冶具1は、磁石2、アルミニウム製の電極3、基盤(アクリル樹脂板)4から構成される。電極3の間隔は1mmであり、大きさ10mm×40mmの平行平板電極を形成する。この電極間にBaフェライト微粒子を200mg挿入し、次いで磁石2(表面磁束密度1500ガウス、対向する部分の磁石面積10mm×30mm)をN極とS極とが対向するように配置してBaフェライト微粒子を電極間に保持する。この電極3に直流電圧1Vステップで1000Vまで印加したときの電流値を計測してブリッジ抵抗値を算出し、その値をBaフェライト微粒子の体積抵抗値とする。
The volume resistance value of the Ba ferrite fine particles under an electric field of 1000 V / cm can be measured with a measuring jig as shown in FIG.
FIG. 1 is a schematic diagram of a measuring jig used for measuring the resistance value of Ba ferrite fine particles.
The measuring jig 1 includes a magnet 2, an aluminum electrode 3, and a base (acrylic resin plate) 4. The distance between the electrodes 3 is 1 mm, and parallel plate electrodes having a size of 10 mm × 40 mm are formed. 200 mg of Ba ferrite fine particles were inserted between the electrodes, and then a magnet 2 (surface magnetic flux density 1500 gauss, magnet area 10 mm × 30 mm of the opposing portion) was placed so that the N pole and the S pole were opposed to each other. Is held between the electrodes. The bridge resistance value is calculated by measuring the current value when 1000 V is applied to the electrode 3 at a DC voltage of 1 V step, and this value is set as the volume resistance value of the Ba ferrite fine particles.
 Baフェライト微粒子としては、キャリア芯材と同様の材質のフェライト微粒子が用いられる。
 Baフェライト微粒子は、0.08~0.8μmの平均粒子径を有するのが好ましく、0.2~0.8μmの平均粒子径を有するのがより好ましい。
 Baフェライト微粒子の平均粒子径が上記の範囲であれば、キャリア芯材の表面に樹脂層を形成する際、Baフェライト微粒子が樹脂層中およびキャリア間で偏在化することを安定して防ぐことができると共に、Baフェライト微粒子によって樹脂層の表面に凹凸が形成されることがないので、均一な樹脂層を形成することができる。この理由は定かではないが、小さな金属酸化微粒子が互いの磁力によって均一に保持されるためではないかと推察される。
 原料となるBaフェライト微粒子が適度な平均粒子径を有さない場合には、予め上記の高抵抗化処理の前にサンドミルのような公知の装置を用いて粉砕処理や分級処理に付してもよい。具体的な処理ついては実施例において説明する。
As the Ba ferrite fine particles, ferrite fine particles of the same material as the carrier core material are used.
The Ba ferrite fine particles preferably have an average particle size of 0.08 to 0.8 μm, and more preferably have an average particle size of 0.2 to 0.8 μm.
If the average particle diameter of the Ba ferrite fine particles is within the above range, it is possible to stably prevent the Ba ferrite fine particles from being unevenly distributed in the resin layer and between the carriers when the resin layer is formed on the surface of the carrier core material. In addition, since no irregularities are formed on the surface of the resin layer by the Ba ferrite fine particles, a uniform resin layer can be formed. The reason for this is not clear, but it is presumed that small metal oxide fine particles are held uniformly by the mutual magnetic force.
If the Ba ferrite fine particles used as a raw material do not have an appropriate average particle size, they may be subjected to pulverization or classification using a known device such as a sand mill in advance before the high resistance treatment. Good. Specific processing will be described in the embodiment.
 Baフェライト微粒子の配合量は特に限定されないが、キャリア芯材1000重量部に対して0.05~65重量部であるのが好ましく、10~40重量部であるのがより好ましい。
 Baフェライト微粒子の配合量が上記の範囲であれば、本発明の優れた効果が発揮される。
 すなわち、樹脂層中のBaフェライト微粒子の配合量は、樹脂100重量部に対して0.05~65重量部であるのが好ましく、10~40重量部であるのがより好ましい。
 Baフェライト微粒子の配合量が0.05重量部未満では、Baフェライト微粒子の効果が充分に得られないことがある。一方、Baフェライト微粒子の配合量が65重量部を超えると、樹脂層を均一に形成できないことがある。
The blending amount of the Ba ferrite fine particles is not particularly limited, but is preferably 0.05 to 65 parts by weight and more preferably 10 to 40 parts by weight with respect to 1000 parts by weight of the carrier core material.
If the compounding quantity of Ba ferrite fine particle is said range, the outstanding effect of this invention will be exhibited.
That is, the compounding amount of the Ba ferrite fine particles in the resin layer is preferably 0.05 to 65 parts by weight and more preferably 10 to 40 parts by weight with respect to 100 parts by weight of the resin.
When the blending amount of the Ba ferrite fine particles is less than 0.05 parts by weight, the effect of the Ba ferrite fine particles may not be sufficiently obtained. On the other hand, when the compounding amount of the Ba ferrite fine particles exceeds 65 parts by weight, the resin layer may not be formed uniformly.
(1-4)導電性微粒子
 樹脂層は、導電性微粒子をさらに含むのが好ましい。
 樹脂層が導電性微粒子を含有することにより、より安定してキャリアのトナーへの帯電付与能力を向上させる、すなわちキャリアをチャージアップさせないことができる。
(1-4) Conductive fine particles The resin layer preferably further contains conductive fine particles.
When the resin layer contains conductive fine particles, the ability of the carrier to impart charge to the toner can be more stably improved, that is, the carrier can be prevented from being charged up.
 導電性微粒子としては、当該技術分野で常用される導電性微粒子であれば特に限定されず、例えば、導電性カーボンブラック、導電性酸化チタンおよび酸化スズなどの酸化物が挙げられる。
 カーボンブラックは、少ない添加量で導電性を発現させることができ、ブラックトナーには好適である。一方、樹脂層からのカーボンブラックの脱離が懸念されることから、カラートナーにはアンチモンをドープさせた導電性酸化チタンなどが好適である。
The conductive fine particles are not particularly limited as long as they are conductive fine particles commonly used in the technical field, and examples thereof include conductive carbon black, oxides such as conductive titanium oxide and tin oxide.
Carbon black can exhibit conductivity with a small addition amount and is suitable for black toner. On the other hand, conductive titanium oxide doped with antimony is suitable for the color toner because there is a concern about the detachment of carbon black from the resin layer.
 導電性微粒子の配合量は特に限定されないが、樹脂100重量部に対して0.1~30重量部であるのが好ましく、1~20重量部であるのがより好ましい。
 導電性微粒子の配合量が0.1重量部未満では、効果が充分に得られないことがある。一方、導電性微粒子の配合量が30重量部を超えると、樹脂層を均一に形成できないことがある。
The blending amount of the conductive fine particles is not particularly limited, but is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the resin.
If the amount of the conductive fine particles is less than 0.1 parts by weight, the effect may not be sufficiently obtained. On the other hand, if the blending amount of the conductive fine particles exceeds 30 parts by weight, the resin layer may not be formed uniformly.
(1-5)カップリング剤
 樹脂層は、トナー帯電量を調整する目的で、シランカップリング剤のようなカップリング剤をさらに含んでいてもよい。
 シランカップリング剤の中でも、電子供与性の官能基を有するシランカップリング剤が好ましく、例えば、次式で示されるアミノ基含有シランカップリング剤が挙げられる。
   (Y)nSi(R)m
(式中、Rは同一または異なってアルキル基、アルコキシ基または塩素原子を示し、Yは同一または異なってアミノ基を含有する炭化水素基を示し、mおよびnはそれぞれ1~3の整数を示し、m+n=4である)
(1-5) Coupling Agent The resin layer may further contain a coupling agent such as a silane coupling agent for the purpose of adjusting the toner charge amount.
Among the silane coupling agents, a silane coupling agent having an electron donating functional group is preferable, and examples thereof include an amino group-containing silane coupling agent represented by the following formula.
(Y) nSi (R) m
(In the formula, R is the same or different and each represents an alkyl group, an alkoxy group or a chlorine atom, Y represents the same or different hydrocarbon group containing an amino group, and m and n each represents an integer of 1 to 3) M + n = 4)
 上記の式において、Rで示されるアルキル基としては、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、tert-ブチル基などの炭素数1~4の直鎖または分岐鎖状のアルキル基が挙げられ、これらの中でも、メチル基、エチル基が好ましい。
 アルコキシ基としては、例えば、メトキシ基、エトキシ基、プロポキシ基、イソプロポキシ基、ブトキシ基、イソブトキシ基、tert-ブトキシ基などの炭素数1~4の直鎖または分岐鎖状のアルコキシ基が挙げられ、これらの中でも、メトキシ基、エトキシ基が好ましい。
 Yで示されるアミノ基を含有する炭化水素基としては、例えば、-(CH2)a-X(式中、Xはアミノ基、アミノカルボニルアミノ基、アミノアルキルアミノ基、フェニルアミノ基またはジアルキルアミノ基を示し、aは1~4の整数である)、-Ph-X(式中、Xは前記に同じであり、-Ph-はフェニレン基を示す)などが挙げられる。
In the above formula, the alkyl group represented by R is, for example, a straight chain or branched chain having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, and tert-butyl group. Examples thereof include a chain alkyl group, and among these, a methyl group and an ethyl group are preferable.
Examples of the alkoxy group include linear or branched alkoxy groups having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, and a tert-butoxy group. Among these, a methoxy group and an ethoxy group are preferable.
Examples of the hydrocarbon group containing an amino group represented by Y include-(CH 2 ) a-X (wherein X is an amino group, an aminocarbonylamino group, an aminoalkylamino group, a phenylamino group or a dialkylamino group). A represents an integer of 1 to 4, and -Ph-X (wherein X is the same as above, -Ph- represents a phenylene group).
 アミノ基含有シランカップリング剤の具体例としては、次のようなものが挙げられる。
 H2N(H2C)3Si(OCH3)3
 H2N(H2C)3Si(OC25)3
 H2N(H2C)3Si(CH3)(OCH3)2
 H2N(H2C)2HN(H2C)3Si(CH3)(OCH3)2
 H2NOCHN(H2C)3Si(OC25)3
 H2N(H2C)2HN(H2C)3Si(OCH3)3
 H2N-Ph-Si(OCH3)3(式中、-Ph-はp-フェニレン基を示す)
 Ph-HN(H2C)3Si(OCH3)3(式中、Ph-はフェニル基を示す)
 (H94)2N(H2C)3Si(OCH3)3
Specific examples of the amino group-containing silane coupling agent include the following.
H 2 N (H 2 C) 3 Si (OCH 3 ) 3
H 2 N (H 2 C) 3 Si (OC 2 H 5 ) 3
H 2 N (H 2 C) 3 Si (CH 3 ) (OCH 3 ) 2
H 2 N (H 2 C) 2 HN (H 2 C) 3 Si (CH 3 ) (OCH 3 ) 2
H 2 NOCHN (H 2 C) 3 Si (OC 2 H 5 ) 3
H 2 N (H 2 C) 2 HN (H 2 C) 3 Si (OCH 3 ) 3
H 2 N—Ph—Si (OCH 3 ) 3 (wherein —Ph— represents a p-phenylene group)
Ph-HN (H 2 C) 3 Si (OCH 3 ) 3 (wherein Ph- represents a phenyl group)
(H 9 C 4 ) 2 N (H 2 C) 3 Si (OCH 3 ) 3
 本発明においては、上記のカップリング剤の1種を単独でまたは2種を組み合わせて用いることができる。
 カップリング剤の配合量は特に限定されないが、樹脂100重量部に対して0.01~10重量部であるのが好ましく、1~10重量部であるのがより好ましい。
 カップリング剤の配合量が上記の範囲であれば、トナーに充分な電荷を付与し、かつ樹脂層の機械的強度などを著しく低下させることがない。
In the present invention, one of the above coupling agents may be used alone or in combination of two.
The blending amount of the coupling agent is not particularly limited, but is preferably 0.01 to 10 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the resin.
When the blending amount of the coupling agent is within the above range, the toner is sufficiently charged and the mechanical strength of the resin layer is not significantly reduced.
(1-6)有機微粒子
 樹脂層は、帯電性をより安定して制御する目的で、有機微粒子をさらに含んでいてもよい。
 有機微粒子は、後述する樹脂層形成用の樹脂液の溶剤に対して溶解しないものから選択すればよい。これにより、有機微粒子が溶解し樹脂層中に微分散して、有機微粒子の帯電制御機能の失効を回避できる
 有機微粒子としては、ベンゾグアナミン樹脂微粒子、メラミン樹脂微粒子およびトリアジン環を含む有機微粒子などが挙げられ、これらの中でも、トリアジン環を含む有機微粒子が好ましい。また、その平均粒子径は、0.1~1μmであるのが好ましい。
(1-6) Organic fine particles The resin layer may further contain organic fine particles for the purpose of more stably controlling the chargeability.
The organic fine particles may be selected from those that do not dissolve in the solvent of the resin liquid for forming the resin layer described later. As a result, the organic fine particles can be dissolved and finely dispersed in the resin layer to avoid the expiration of the charge control function of the organic fine particles. Examples of the organic fine particles include benzoguanamine resin fine particles, melamine resin fine particles, and organic fine particles containing a triazine ring. Among these, organic fine particles containing a triazine ring are preferable. The average particle diameter is preferably 0.1 to 1 μm.
 有機微粒子の配合量は特に限定されないが、樹脂100重量部に対して0.1~50重量部であるのが好ましく、1~30重量部であるのがより好ましい。
 有機微粒子の配合量が0.1重量部未満では、効果が充分に得られないことがある。一方、有機微粒子の配合量が50重量部を超えると、樹脂層を均一に形成できないことがある。
The blending amount of the organic fine particles is not particularly limited, but is preferably 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the resin.
If the amount of the organic fine particles is less than 0.1 parts by weight, the effect may not be sufficiently obtained. On the other hand, if the amount of the organic fine particles exceeds 50 parts by weight, the resin layer may not be formed uniformly.
(1-7)キャリアの製造
 本発明のキャリアは、キャリア芯材の表面に、上記の樹脂層の構成材料を溶剤中に溶解または分散させた樹脂液を塗布した後、溶剤を揮発除去して塗布層を形成し、さらに乾燥時または乾燥後に塗布層を加熱硬化または単に硬化させることによって製造することができる。
(1-7) Production of Carrier The carrier of the present invention is obtained by applying a resin solution in which the constituent material of the resin layer is dissolved or dispersed in a solvent to the surface of the carrier core material, and then volatilizing and removing the solvent. It can be produced by forming a coating layer and further heat-curing or simply curing the coating layer during or after drying.
 溶剤としては、使用する樹脂を溶解できるものであれば特に限定されず、例えば、トルエン、キシレンなどの芳香族炭化水素類、アセトン、メチルエチルケトンなどのケトン類、テトラヒドロフラン、ジオキサンなどのエーテル類、高級アルコール類のような有機溶剤が挙げられる。溶剤は1種を単独でまたは2種を組み合わせて用いることができる。 The solvent is not particularly limited as long as it can dissolve the resin to be used. For example, aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and higher alcohols. Organic solvents such as A solvent can be used individually by 1 type or in combination of 2 types.
 キャリア芯材の表面に樹脂液を塗布する方法としては、公知の方法が採用できる。例えば、樹脂液中にキャリア芯材を浸漬させる浸漬法、樹脂液をキャリア芯材に噴霧するスプレー法、キャリア芯材を流動エアにより浮遊させた状態で樹脂液を噴霧する流動床法、ニーダーコーター中でキャリア芯材と樹脂液とを混合し、溶媒を除去するニーダーコーター法などが挙げられる。これらの中でも、膜形成が容易である点で浸漬法が好ましい。 As a method of applying the resin liquid to the surface of the carrier core material, a known method can be adopted. For example, a dipping method in which the carrier core material is immersed in the resin liquid, a spray method in which the resin liquid is sprayed on the carrier core material, a fluidized bed method in which the resin liquid is sprayed in a state where the carrier core material is floated by flowing air, a kneader coater Among them, a kneader coater method in which a carrier core material and a resin liquid are mixed and a solvent is removed may be used. Among these, the dipping method is preferable in that film formation is easy.
 塗布層の乾燥には、乾燥促進剤を用いてもよい。
 乾燥促進剤としては公知のものを使用でき、例えば、ナフチル酸、オクチル酸などの鉛、鉄、コバルト、マンガン、亜鉛塩などの金属石鹸、エタノールアミンなどの有機アミン類などが挙げられる。乾燥促進剤は1種を単独でまたは2種を組み合わせて用いることができる。その添加量は、溶剤100重量部に対して0.1~5重量部程度である。
A drying accelerator may be used for drying the coating layer.
Known drying accelerators can be used, and examples thereof include lead such as naphthylic acid and octylic acid, metal soap such as iron, cobalt, manganese and zinc salts, and organic amines such as ethanolamine. A drying accelerator can be used individually by 1 type or in combination of 2 types. The amount added is about 0.1 to 5 parts by weight per 100 parts by weight of the solvent.
 塗布層の硬化は、樹脂や溶剤の種類に応じて加熱温度を適宜設定すればよく、例えば、150~280℃程度の加熱が挙げられる。樹脂として常温硬化型シリコーン樹脂を用いる場合には、加熱を必要としないが、形成される樹脂層の機械的強度を向上させること、硬化時間を短縮することなどを目的として、150~280℃程度に加熱してもよい。 The curing of the coating layer may be performed by appropriately setting the heating temperature according to the type of resin or solvent, for example, heating at about 150 to 280 ° C. When a normal temperature curable silicone resin is used as the resin, heating is not required, but it is about 150 to 280 ° C. for the purpose of improving the mechanical strength of the formed resin layer and shortening the curing time. You may heat to.
 樹脂液の全固形分濃度は特に限定されないが、キャリア芯材への塗布作業性などを考慮しつつ、硬化後の樹脂層の膜厚が通常5μm以下、好ましくは0.1~3μm程度になるように調整すればよい。
 このようにして得られるキャリアは、高電気抵抗でかつ球形であることが好ましいが、導電性または非球形であっても本発明の効果が失われるものではない。
Although the total solid content concentration of the resin liquid is not particularly limited, the film thickness of the cured resin layer is usually 5 μm or less, preferably about 0.1 to 3 μm, taking into consideration the workability of application to the carrier core material. It may be adjusted as follows.
The carrier thus obtained preferably has a high electrical resistance and a spherical shape, but the effect of the present invention is not lost even if it is conductive or non-spherical.
(2)2成分現像剤
 本発明の2成分現像剤は、本発明のキャリアとトナーとを含む。トナーについては次項(3)において説明する。
(2) Two-component developer The two-component developer of the present invention includes the carrier of the present invention and a toner. The toner will be described in the next section (3).
 本発明の2成分現像剤は、本発明のキャリアとトナーとを混合することにより製造できる。
 キャリアとトナーとの混合割合は特に限定されないが、高速画像形成装置(A4サイズの画像で40枚/分以上)に用いることを考慮すると、キャリアの平均粒子径Dk/トナーの平均粒子径Dtが5以上の状態で、キャリアの総表面積Sk(全キャリア粒子の表面積の総和)に対するトナーの総投影面積St(全トナー粒子の投影面積の総和)の割合(St/Sk×100)が30~70%になるように混合するのが好ましい。これにより、トナーの帯電性が充分良好な状態で安定的に維持され、高速画像形成装置においても高画質画像を安定的にかつ長期的に形成できる好適な2成分現像剤として使用できる。
The two-component developer of the present invention can be produced by mixing the carrier of the present invention and a toner.
The mixing ratio of the carrier and the toner is not particularly limited, but considering that it is used in a high-speed image forming apparatus (40 sheets / min or more for A4 size images), the average particle diameter Dk of the carrier / the average particle diameter Dt of the toner is In a state of 5 or more, the ratio (St / Sk × 100) of the total projected area St (total projected area of all toner particles) of the toner to the total surface area Sk (total of the surface areas of all carrier particles) of the carrier is 30 to 70 It is preferable to mix so that it may become%. As a result, the chargeability of the toner can be stably maintained in a sufficiently good state, and it can be used as a suitable two-component developer that can stably form a high-quality image for a long period of time even in a high-speed image forming apparatus.
 「樹脂被覆キャリアの表面積」は、次のようにして測定することができる。
 例えば、粒度分布測定装置(日機装株式会社製、型式:マイクロトラックMT3000)によりキャリアの平均粒子径を測定し、これに基づき、キャリアの比重を4.7として、混合するキャリアの重量から算出する。
 また、「トナーの投影面積」は、次のようにして測定することができる。
 例えば、粒度分布測定装置(ベックマン・コールター株式会社製、型式:コールターカウンタ・マルチサイザーII)によりトナーの平均粒子径を測定し、これに基づき、トナーの比重を1.0として、混合するトナー重量に対するトナー個数を算出し、トナー個数×トナー面積(円と仮定して算出)でトナー総面積とする。
 上記の結果から、St/Sk×100を算出する。
The “surface area of the resin-coated carrier” can be measured as follows.
For example, the average particle diameter of the carrier is measured by a particle size distribution measuring apparatus (manufactured by Nikkiso Co., Ltd., model: Microtrac MT3000), and based on this, the specific gravity of the carrier is set to 4.7, and calculation is performed from the weight of the carrier to be mixed.
The “projection area of toner” can be measured as follows.
For example, the average particle diameter of the toner is measured by a particle size distribution measuring device (manufactured by Beckman Coulter, Inc., model: Coulter Counter Multisizer II), and based on this, the toner weight is 1.0 The number of toners is calculated, and the total toner area is calculated by toner number × toner area (calculated assuming a circle).
From the above result, St / Sk × 100 is calculated.
 例えば、Dk=90μm、Dt=6.5μmであるとき、St/Sk×100を30~70%にするには、2成分現像剤におけるキャリア100重量部に対するトナーを2.2~5.3重量部程度になるようにすればよい。
 このような2成分現像剤で高速現像すると、トナー消費量とトナーの消費に応じて現像装置の現像槽に供給されるトナー供給量とがそれぞれ最大になり、それでも需給バランスが損なわれることがない。
 2成分現像剤におけるキャリアの量が多い場合、帯電量がより低くなる傾向があり、所望の現像特性が得られないばかりか、トナー供給量よりもトナー消費量の方が多くなり、トナーに充分な電荷を付与できなくなり、画質の劣化を招くことがある。一方、キャリアの量が少ない場合、帯電量が高くなる傾向があり、樹脂被覆キャリアからトナーが電界によって分離し難くなり、結果として画質の劣化を招くことがある。
For example, when Dk = 90 μm and Dt = 6.5 μm, in order to make St / Sk × 100 30 to 70%, 2.2 to 5.3 weight of toner with respect to 100 parts by weight of carrier in the two-component developer What is necessary is just to be about a part.
When high-speed development is performed with such a two-component developer, the toner consumption amount and the toner supply amount supplied to the developing tank of the developing device according to the toner consumption are maximized, and the balance between supply and demand is not lost. .
When the amount of the carrier in the two-component developer is large, the charge amount tends to be lower, and not only the desired development characteristics cannot be obtained, but the toner consumption amount is larger than the toner supply amount, which is sufficient for the toner. May not be able to provide a sufficient charge, which may lead to degradation of image quality. On the other hand, when the amount of the carrier is small, the charge amount tends to be high, and it becomes difficult for the toner to be separated from the resin-coated carrier by an electric field, resulting in deterioration of image quality.
(3)トナー
 トナーは、当該技術分野で常用されるトナーであれば特に限定されず、結着樹脂および着色剤を必須成分とし、必要に応じて離型剤、荷電制御剤などの公知の添加剤を含むトナー母粒子からなり、必要に応じて外添剤が添加されていてもよい。
(3) Toner The toner is not particularly limited as long as it is a toner commonly used in the technical field, and includes a binder resin and a colorant as essential components, and known additions such as a release agent and a charge control agent as necessary. It consists of toner base particles containing an agent, and an external additive may be added as necessary.
(3-1)結着樹脂
 結着樹脂としては、当該技術分野で常用されるトナー用の樹脂であれば特に限定されず、例えば、ポリエステル系樹脂、ポリスチレン、スチレン-アクリル酸エステル共重合樹脂などのスチレン系樹脂、ポリメチルメタクリレートなどのアクリル系樹脂、ポリエチレンなどのポリオレフィン系樹脂、ポリウレタン、エポキシ樹脂などが挙げられる。また、原料モノマー混合物に離型剤を混合し、重合反応を行って得られる樹脂を用いてもよい。
 本発明においては、上記の結着樹脂の1種を単独でまたは2種以上組み合わせて用いることができる。
(3-1) Binder Resin The binder resin is not particularly limited as long as it is a resin for toners commonly used in the technical field. For example, polyester resin, polystyrene, styrene-acrylate copolymer resin, and the like. Styrene resins, acrylic resins such as polymethyl methacrylate, polyolefin resins such as polyethylene, polyurethane, and epoxy resins. Moreover, you may use resin obtained by mixing a raw material monomer mixture with a mold release agent and performing a polymerization reaction.
In the present invention, one of the above binder resins can be used alone or in combination of two or more.
 上記の結着樹脂の中でも、ポリエステル系樹脂(以下「ポリエステル樹脂」という)を好適に用いることができる。
 ポリエステル樹脂は、通常、2価のアルコール成分および3価以上の多価アルコール成分から選ばれる1種以上と、2価のカルボン酸および3価以上の多価カルボン酸から選ばれる1種以上とを、公知の方法により縮重合反応もしくはエステル化、エステル交換反応により得られる。
 縮重合反応における条件は、モノマー成分の反応性により適宜設定すればよく、また重合体が好適な物性になった時点で反応を終了させればよい。例えば、反応温度は170~250℃程度、反応圧力は5mmHg~常圧程度である。
Among the above binder resins, polyester resins (hereinafter referred to as “polyester resins”) can be suitably used.
The polyester resin usually includes at least one selected from a divalent alcohol component and a trihydric or higher polyhydric alcohol component, and at least one selected from a divalent carboxylic acid and a trivalent or higher polyvalent carboxylic acid. It can be obtained by a polycondensation reaction, esterification or transesterification by a known method.
The conditions in the condensation polymerization reaction may be set as appropriate depending on the reactivity of the monomer component, and the reaction may be terminated when the polymer has suitable physical properties. For example, the reaction temperature is about 170 to 250 ° C., and the reaction pressure is about 5 mmHg to normal pressure.
 2価のアルコール成分としては、例えば、ポリオキシプロピレン(2.2)-2,2-ビス(4-ヒドロキシフェニル)プロパン、ポリオキシプロピレン(3.3)-2,2-ビス(4-ヒドロキシフェニル)プロパン、ポリオキシプロピレン(2.0)-2,2-ビス(4-ヒドロキシフェニル)プロパン、ポリオキシプロピレン(2.0)-ポリオキシエチレン(2.0)-2,2-ビス(4-ヒドロキシフェニル)プロパン、ポリオキシプロピレン(6)-2,2-ビス(4-ヒドロキシフェニル)プロパンなどのビスフェノールAのアルキレンオキシド付加物;エチレングリコール、ジエチレングリコール、トリエチレングリコール、1,2-プロピレングリコール、1,3-プロピレングリコール、1,4-ブタンジオール、ネオペンチルグリコール、1,4-ブテンジオール、1,5-ペンタンジオール、1,6-ヘキサンジオール、1,4-シクロヘキサンジメタノール、ジプロピレングリコール、ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコールなどのジオール類;ビスフェノールA;ビスフェノールAのプロピレン付加物;ビスフェノールAのエチレン付加物;水素添加ビスフェノールAなどが挙げられる。 Examples of the divalent alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxy). Phenyl) propane, polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis ( Alkylene oxide adducts of bisphenol A such as 4-hydroxyphenyl) propane and polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene Glycol, 1,3-propylene glycol, 1,4-butanediol, ne Diols such as pentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol Bisphenol A; propylene adduct of bisphenol A; ethylene adduct of bisphenol A; hydrogenated bisphenol A and the like.
 3価以上の多価アルコール成分としては、例えば、ソルビトール、1,2,3,6-ヘキサンテトロール、1,4-ソルビタン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、スクロース(蔗糖)、1,2,4-ブタントリオール、1,2,5-ペンタントリオール、グリセロール、2-メチルプロパントリオール、2-メチル-1,2,4-ブタントリオール、トリメチロールエタン、トリメチロールプロパン、1,3,5-トリヒドロキシメチルベンゼンなどが挙げられる。
 本発明においては、上記の2価のアルコール成分および3価以上の多価アルコール成分の1種を単独でまたは2種以上を組み合わせて用いることができる。
Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1 , 2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3, And 5-trihydroxymethylbenzene.
In the present invention, one of the above divalent alcohol component and trihydric or higher polyhydric alcohol component can be used alone or in combination of two or more.
 2価のカルボン酸として、例えば、マレイン酸、フマル酸、シトラコン酸、イタコン酸、グルタコン酸、フタル酸、イソフタル酸、テレフタル酸、シクロヘキサンジカルボン酸、コハク酸、アジピン酸、セバチン酸、アゼライン酸、マロン酸、n-ドデセニルコハク酸、n-ドデシルコハク酸、n-オクチルコハク酸、イソオクテニルコハク酸、イソオクチルコハク酸およびこれらの酸無水物もしくは低級アルキルエステルなどが挙げられる。 Examples of divalent carboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malon Examples include acids, n-dodecenyl succinic acid, n-dodecyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, and acid anhydrides or lower alkyl esters thereof.
 3価以上の多価カルボン酸としては、例えば、1,2,4-ベンゼントリカルボン酸、1,2,5-ベンゼントリカルボン酸、2,5,7-ナフタレントリカルボン酸、1,2,4-ナフタレントリカルボン酸、1,2,4-ブタントリカルボン酸、1,2,5-ヘキサントリカルボン酸、1,3-ジカルボキシル-2-メチル-2-メチレンカルボキシプロパン、1,2,4-シクロヘキサントリカルボン酸、テトラ(メチレンカルボキシル)メタン、1,2,7,8-オクタンテトラカルボン酸、ピロメリット酸、エンポール三量体酸およびこれらの酸無水物もしくは低級アルキルエステルなどが挙げられる。
 本発明においては、上記の2価のカルボン酸および3価以上の多価カルボン酸の1種を単独でまたは2種以上を組み合わせて用いることができる。
Examples of the trivalent or higher polyvalent carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, and 1,2,4-naphthalene. Tricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, Examples thereof include tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, and acid anhydrides or lower alkyl esters thereof.
In the present invention, one of the above divalent carboxylic acids and trivalent or higher polyvalent carboxylic acids can be used alone or in combination of two or more.
 ポリエステル樹脂は、5~30mgKOH/gの酸価を有するのが好ましい。
 ポリエステル樹脂の酸価が5mgKOH/g未満では、樹脂の帯電特性が低下し、また荷電制御剤がポリエステル樹脂中に分散し難くなり、帯電立ち上がり性や連続使用時の帯電安定性に悪影響を及ぼすことがある。一方、ポリエステル樹脂の酸価が30mgKOH/gを超えると、吸湿性が高くなり帯電性が不安定になることがある。
The polyester resin preferably has an acid value of 5 to 30 mg KOH / g.
If the acid value of the polyester resin is less than 5 mgKOH / g, the charging characteristics of the resin will be lowered, and the charge control agent will be difficult to disperse in the polyester resin, which will adversely affect the charge build-up property and the charging stability during continuous use. There is. On the other hand, when the acid value of the polyester resin exceeds 30 mgKOH / g, the hygroscopicity becomes high and the chargeability may become unstable.
(3-2)着色剤
 着色剤としては、当該技術分野で常用される有機系および無機系の様々な種類および色の顔料および染料を用いることができ、例えば、黒色(ブラック)、白色、黄色(イエロー)、橙色、赤色(マゼンタ)、紫色、青色(シアン)および緑色の着色剤が挙げられる。
(3-2) Colorant As the colorant, various types of organic and inorganic pigments and dyes commonly used in the technical field can be used. For example, black (black), white, yellow (Yellow), orange, red (magenta), purple, blue (cyan) and green colorants.
 黒色(ブラック)の着色剤としては、例えば、カーボンブラックおよび複合酸化物ブラックなどの無機顔料;アニリンブラックのような有機顔料が挙げられる。
 カーボンブラックは、その製造法などにより、チャンネルブラック、ローラーブラック、ディスクブラック、ガスファーネスブラック、オイルファーネスブラック、サーマルブラックおよびアセチレンブラックなどに分類され、これらの中から、得ようとするトナーの設計特性に応じて、適切なカーボンブラックを適宜選択すればよい。
Examples of the black colorant include inorganic pigments such as carbon black and composite oxide black; and organic pigments such as aniline black.
Carbon black is classified into channel black, roller black, disk black, gas furnace black, oil furnace black, thermal black, acetylene black, etc. according to its manufacturing method, etc., and from these, the design characteristics of the toner to be obtained Depending on the case, an appropriate carbon black may be appropriately selected.
 白色の着色剤としては、例えば、炭酸カルシウム、硫酸バリウム、酸化亜鉛(亜鉛華)、リトポン、酸化チタン、アンチモン白および硫化亜鉛などの無機顔料が挙げられる。 Examples of the white colorant include inorganic pigments such as calcium carbonate, barium sulfate, zinc oxide (zinc white), lithopone, titanium oxide, antimony white, and zinc sulfide.
 黄色(イエロー)の着色剤としては、例えば、黄鉛、カドミウムイエロー、黄色酸化鉄、複合酸化物イエロー、ビスマスイエロー、クロムイエロー、ニッケルチタンイエローおよび黄土などの無機顔料;カラーインデックスによって分類されるC.I.ピグメントイエロー1、C.I.ピグメントイエロー5、C.I.ピグメントイエロー12、C.I.ピグメントイエロー15、およびC.I.ピグメントイエロー17、C.I.ピグメントイエロー74、C.I.ピグメントイエロー93、C.I.ピグメントイエロー180およびC.I.ピグメントイエロー185などの有機顔料;C.I.アシッドイエロー1などのニトロ系染料、C.I.ソルベントイエロー2、C.I.ソルベントイエロー6、C.I.ソルベントイエロー14、C.I.ソルベントイエロー15、C.I.ソルベントイエロー19およびC.I.ソルベントイエロー21などの油溶性染料などが挙げられる。 Examples of yellow colorants include inorganic pigments such as yellow lead, cadmium yellow, yellow iron oxide, composite oxide yellow, bismuth yellow, chrome yellow, nickel titanium yellow, and ocher; C classified by color index Pigment Yellow 1, CI Pigment Yellow 5, CI Pigment Yellow 12, CI Pigment Yellow 15, and CI Pigment Yellow 17, CI Pigment Yellow 74, C.I. Organic pigments such as CI Pigment Yellow 93, CI Pigment Yellow 180 and CI Pigment Yellow 185; Nitro dyes such as CI Acid Yellow 1; CI Solvent Yellow 2 and CI Solvent Yellow 6, CI Solvent Yellow 14, CI Solvent Yellow 15, C And oil-soluble dyes such as CI Solvent Yellow 19 and CI Solvent Yellow 21.
 橙色の着色剤としては、例えば、赤色黄鉛およびモリブデンオレンジなどの無機顔料;パーマネントオレンジGTR、ピラゾロンオレンジ、バルカンオレンジ、インダスレンブリリアントオレンジRK、ベンジジンオレンジGおよびインダスレンブリリアントオレンジGK、カラーインデックスによって分類されるC.I.ピグメントオレンジ31およびC.I.ピグメントオレンジ43などの有機顔料が挙げられる。 Orange colorants include, for example, inorganic pigments such as red yellow lead and molybdenum orange; permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G and indanthrene brilliant orange GK, classified by color index C. I. Pigment orange 31 and C.I. I. And organic pigments such as CI Pigment Orange 43.
 赤色(マゼンタ)の着色剤としては、例えば、ベンガラ、カドミウムレッド、鉛丹、硫化水銀およびモリブデンレッドなどの無機顔料;カラーインデックスによって分類されるC.I.ピグメントレッド49、C.I.ピグメントレッド57、C.I.ピグメントレッド81、C.I.ピグメントレッド122、C.I.ソルベントレッド19、C.I.ソルベントレッド49、C.I.ソルベントレッド52、C.I.ベーシックレッド10およびC.I.ディスパーズレッド15などの有機顔料が挙げられる。 Examples of red (magenta) colorants include inorganic pigments such as Bengala, cadmium red, red lead, mercury sulfide, and molybdenum red; CI Pigment Red 49 and CI Pigment Red classified by color index. 57, CI Pigment Red 81, CI Pigment Red 122, CI Solvent Red 19, CI Solvent Red 49, CI Solvent Red 52, CI Basic Red 10 and And organic pigments such as CI Disperse Red 15.
 紫色の着色剤としては、例えば、マンガン紫のような無機顔料;ファストバイオレットBおよびメチルバイオレットレーキなどの有機顔料が挙げられる。 Examples of purple colorants include inorganic pigments such as manganese purple; organic pigments such as fast violet B and methyl violet lake.
 青色(シアン)の着色剤としては、例えば、例えば、紺青およびコバルトブルーなどの無機顔料;カラーインデックスによって分類されるC.I.ピグメントブルー15、C.I.ピグメントブルー16、C.I.ソルベントブルー55、C.I.ソルベントブルー70、C.I.ダイレクトブルー25、C.I.ダイレクトブルー86およびKET.BLUE111などの有機顔料が挙げられる。 Examples of the blue (cyan) colorant include, for example, inorganic pigments such as bitumen and cobalt blue; CI pigment blue 15, CI pigment blue 16, and CI solvent classified by color index. Blue 55, CI Solvent Blue 70, CI Direct Blue 25, CI Direct Blue 86 and KET. And organic pigments such as BLUE111.
 緑色の着色剤としては、例えば、クロムグリーンおよび酸化クロムなどの無機顔料;ピクメントグリーンB、マイカライトグリーンレーキ、カラーインデックスによって分類されるファイナルイエローグリーンGおよびC.I.ピグメントグリーン7などの有機顔料が挙げられる。 Examples of the green colorant include inorganic pigments such as chrome green and chrome oxide; final green green G and C. which are classified by pigment green B, micalite green lake, and color index. I. And organic pigments such as CI Pigment Green 7.
 顔料は染料に比べて耐光性および発色性に優れ、耐光性および発色性に優れるトナーを得ることができるので、着色剤としては顔料が好ましい。
 本発明においては、上記の着色剤の1種を単独でまたは2種を組み合わせて用いることができ、それらの組み合わせは異色であっても同色であってもよい。
 2種以上の着色剤を複合粒子化して用いてもよい。複合粒子は、例えば、2種以上の着色剤に適量の水、低級アルコールなどを添加し、ハイスピードミルなどの一般的な造粒機で造粒し、乾燥させることによって製造できる。
 また、結着樹脂中に着色剤を均一に分散させるために、マスターバッチ化して用いてもよい。
 複合粒子およびマスターバッチは、乾式混合の際にトナー組成物に混入される。
A pigment is preferable as a colorant because the pigment is excellent in light resistance and color developability as compared with a dye, and a toner excellent in light resistance and color developability can be obtained.
In the present invention, one of the above colorants may be used alone or in combination of two, and these combinations may be different colors or the same color.
Two or more colorants may be used as composite particles. The composite particles can be produced, for example, by adding an appropriate amount of water, lower alcohol or the like to two or more colorants, granulating with a general granulator such as a high speed mill, and drying.
Further, in order to uniformly disperse the colorant in the binder resin, a master batch may be used.
The composite particles and the master batch are mixed into the toner composition during dry mixing.
 マスターバッチは、例えば、結着樹脂および着色剤を混合機で乾式混合し、得られた粉体混合物を混練機で混練し、得られた混練物を、例えば粒子径2mm~3mm程度に粉砕することにより製造することができる。結着樹脂には、トナーの結着樹脂と同種のものかまたはトナーの結着樹脂に対して良好な相溶性を有するものが使用される。
 結着樹脂と着色剤との配合割合は特に限定されないが、結着樹脂100重量部に対する着色剤は30~100重量部程度である。
In the master batch, for example, the binder resin and the colorant are dry-mixed with a mixer, the obtained powder mixture is kneaded with a kneader, and the obtained kneaded product is pulverized to, for example, a particle size of about 2 mm to 3 mm. Can be manufactured. As the binder resin, the same kind as that of the toner binder resin or a resin having good compatibility with the toner binder resin is used.
The mixing ratio of the binder resin and the colorant is not particularly limited, but the colorant is about 30 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
 マスターバッチの乾式混合には、当該技術分野で常用される公知の装置を使用でき、例えば、ヘンシェルミキサ(商品名、三井鉱山株式会社(現 日本コークス工業株式会社)製)、スーパーミキサ(商品名、株式会社カワタ製)、メカノミル(商品名、岡田精工株式会社製)などのヘンシェルタイプの混合装置、オングミル(商品名、ホソカワミクロン株式会社製)、ハイブリダイゼーションシステム(商品名、株式会社奈良機械製作所製)、コスモシステム(商品名、川崎重工業株式会社製)などの混合機が挙げられる。
 混合の条件は、使用する混合機やマスターバッチ原料などにより適宜設定すればよい。
For dry mixing of the masterbatch, a known apparatus commonly used in the technical field can be used. For example, Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd. (currently Nihon Coke Industries)), super mixer (trade name) Henshell type mixing devices such as Mechanomyl (trade name, manufactured by Okada Seiko Co., Ltd.), Ongmill (trade name, manufactured by Hosokawa Micron Corporation), Hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.) ) And Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.).
What is necessary is just to set the conditions of mixing suitably with the mixer, masterbatch raw material, etc. to be used.
 マスターバッチの溶融混練には、当該技術分野で常用される公知の装置を使用でき、一軸、二軸または多軸の押出機(エクストルーダ)、ニーダ、二本または三本のロールミル、ラボブラストミルなどの一般的な混練機が挙げられる。具体的には、TEM-100B(型式、東芝機械株式会社製)、PCM-65/87、PCM-30(以上いずれも型式、株式会社池貝製)などの一軸または二軸押出機、ニーデックス(商品名、三井鉱山株式会社(現 日本コークス工業株式会社)製)などのオープンロール方式の混練機が挙げられる。これらの混練機の1種を単独でまたは2種以上を組み合わせて用いることができる。
 混練温度は、結着樹脂の軟化温度などの条件によるが、通常50~150℃程度、好ましくは50~120℃程度である。
 他の溶融混練の条件は、使用する混練機やマスターバッチ原料などにより適宜設定すればよい。
For the melt-kneading of the masterbatch, known apparatuses commonly used in the technical field can be used, such as a single-screw, twin-screw or multi-screw extruder (extruder), a kneader, two or three roll mills, a lab blast mill, etc. The following general kneaders may be mentioned. Specifically, TEM-100B (model, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of these models, manufactured by Ikegai Co., Ltd.), etc. Examples thereof include open roll type kneaders such as trade name, Mitsui Mining Co., Ltd. (currently Nihon Coke Industries Co., Ltd.). One of these kneaders can be used alone or in combination of two or more.
The kneading temperature depends on conditions such as the softening temperature of the binder resin, but is usually about 50 to 150 ° C, preferably about 50 to 120 ° C.
Other melt kneading conditions may be appropriately set depending on the kneader to be used, the master batch raw material, and the like.
 着色剤の配合量は特に限定されないが、結着樹脂100重量部に対して5~20重量部であるのが好ましく、5~10重量部であるのがより好ましい。
 マスターバッチを用いる場合には、着色剤の配合量が上記の範囲内になるように、マスターバッチの使用量を調整すればよい。
 着色剤の配合量が上記の範囲内であれば、トナーの各種物性を損なうことなしに、高い画像濃度および画質品位を有する画像を形成することができる。
The blending amount of the colorant is not particularly limited, but is preferably 5 to 20 parts by weight, and more preferably 5 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
When using a masterbatch, the amount of the masterbatch used may be adjusted so that the blending amount of the colorant is within the above range.
When the blending amount of the colorant is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
(3-3)離型剤(「ワックス」ともいう)
 離型剤としては、当該技術分野で常用される離型剤を用いることができ、例えば、パラフィンワックスおよびマイクロクリスタリンワックスならびにそれらの誘導体などの石油系ワックス;フィッシャートロプシュワックス、ポリオレフィンワックス(ポリエチレンワックス、ポリプロピレンワックスなど)、低分子量ポリプロピリンワックスおよびポリオレフィン系重合体ワックス(低分子量ポリエチレンワックスなど)ならびにそれらの誘導体などの炭化水素系合成ワックス;カルナバワックス、ライスワックスおよびキャンデリラワックスならびにそれらの誘導体、木蝋などの植物系ワックス;蜜蝋、鯨蝋などの動物系ワックス;脂肪酸アミドおよびフェノール脂肪酸エステルなどの油脂系合成ワックス;長鎖カルボン酸およびその誘導体;長鎖アルコールおよびその誘導体;シリコーン系重合体;高級脂肪酸などが挙げられる。なお、誘導体には、酸化物、ビニル系モノマーとワックスとのブロック共重合物、ビニル系モノマーとワックスとのグラフト変性物などが含まれる。
 本発明においては、上記の離型剤の1種を単独でまたは2種以上を組み合わせて用いることができる。
(3-3) Release agent (also called “wax”)
As the release agent, release agents commonly used in the art can be used, for example, petroleum wax such as paraffin wax and microcrystalline wax and derivatives thereof; Fischer-Tropsch wax, polyolefin wax (polyethylene wax, Hydrocarbon waxes such as polypropylene wax), low molecular weight polypropylin wax and polyolefin polymer wax (such as low molecular weight polyethylene wax) and derivatives thereof; carnauba wax, rice wax and candelilla wax and derivatives thereof, wood wax Plant waxes such as beeswax, animal waxes such as beeswax and spermaceti; oils and fats synthetic waxes such as fatty acid amides and phenol fatty acid esters; long chain carboxylic acids and derivatives thereof Body; long-chain alcohols and derivatives thereof; silicone polymer; such as higher fatty acids. Derivatives include oxides, block copolymers of vinyl monomers and waxes, graft modified products of vinyl monomers and waxes, and the like.
In this invention, 1 type of said mold release agent can be used individually or in combination of 2 or more types.
 離型剤は、炭化水素系離型剤であるのが好ましい。また、その融点は70℃以下であるのが好ましく、その下限は60℃程度である。
 離型剤の配合量は特に限定されないが、結着樹脂100重量部に対して0.2~20重量部であるのが好ましく、1~10重量部であるのがより好ましい。
 離型剤の配合量が上記の範囲内であれば、トナーの各種物性を損なうことなしに、高い画像濃度および画質品位を有する画像を形成することができる。
The release agent is preferably a hydrocarbon release agent. Moreover, it is preferable that the melting | fusing point is 70 degrees C or less, and the minimum is about 60 degreeC.
The compounding amount of the release agent is not particularly limited, but is preferably 0.2 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
When the amount of the release agent is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
(3-4)荷電制御剤(「電荷制御剤」、「帯電制御剤」ともいう)
 荷電制御剤としては、当該技術分野で常用される正電荷制御用および負電荷制御用の荷電制御剤を用いることができる。
(3-4) Charge control agent (also referred to as “charge control agent” or “charge control agent”)
As the charge control agent, charge control agents for positive charge control and negative charge control that are commonly used in the art can be used.
 正電荷制御用の荷電制御剤としては、例えば、ニグロシン染料、塩基性染料、四級アンモニウム塩、四級ホスホニウム塩、アミノピリン、ピリミジン化合物、多核ポリアミノ化合物、アミノシラン、ニグロシン染料およびその誘導体、トリフェニルメタン誘導体、グアニジン塩、アミジン塩などが挙げられる。
 負電荷制御用の荷電制御剤としては、例えば、オイルブラック、スピロンブラックなどの油溶性染料、含金属アゾ化合物、アゾ錯体染料、ナフテン酸金属塩、サリチル酸およびその誘導体の金属錯体および金属塩(金属はクロム、亜鉛、ジルコニウムなど)、ホウ素化合物、脂肪酸石鹸、長鎖アルキルカルボン酸塩、樹脂酸石鹸などが挙げられる。
 これらの中でもホウ素化合物は重金属を含まないことから特に好ましい。
Examples of the charge control agent for positive charge control include nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, triphenylmethane. Derivatives, guanidine salts, amidine salts and the like can be mentioned.
Examples of charge control agents for controlling negative charges include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, naphthenic acid metal salts, metal complexes and metal salts of salicylic acid and its derivatives ( Examples of the metal include chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, and resin acid soaps.
Among these, boron compounds are particularly preferable because they do not contain heavy metals.
 本発明においては、上記の荷電制御剤の1種を単独でまたは2種以上を組み合わせて用いることができる。
 荷電制御剤の配合量は特に限定されないが、結着樹脂100重量部に対して0.5~3重量部であるのが好ましく、0.5~2重量部であるのが特に好ましい。
 電荷制御剤の配合量が上記の範囲内であれば、トナーの各種物性を損なうことなしに、高い画像濃度および画質品位を有する画像を形成することができる。
In the present invention, one of the above charge control agents may be used alone or in combination of two or more.
The blending amount of the charge control agent is not particularly limited, but is preferably 0.5 to 3 parts by weight, particularly preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the binder resin.
If the blending amount of the charge control agent is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
(3-5)トナーの製造方法
(トナーの製造方法)
 トナーは、一般的なトナーの製造方法、例えば粉砕法などの乾式法、懸濁重合法、乳化凝集法、分散重合法、溶解懸濁法および溶融乳化法などの湿式法のような公知の方法により作製することができる。これらの中でも、粉砕法は、湿式などに比較して工程が少なく設備投資額も少なく済むなどの点で特に好ましい。
 粉砕法によるトナーの作製では、少なくとも結着樹脂、着色剤および離型剤、任意に荷電制御剤を含むトナー材料を混合・溶融混練して混練物を得、次いで混練物を冷却固化・粉砕し、その後必要に応じて分級などの粒度調整を行い、トナー粒子を得る。
 混合、溶融混練、粉砕および分級の各工程には、公知の装置を用いることができる。
(3-5) Toner manufacturing method (Toner manufacturing method)
The toner is a known method such as a general toner production method, for example, a dry method such as a pulverization method, a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsion method. Can be produced. Among these, the pulverization method is particularly preferable in that the number of steps is small and the amount of capital investment is small as compared with the wet method.
In the preparation of toner by a pulverization method, a toner material containing at least a binder resin, a colorant and a release agent, and optionally a charge control agent is mixed and melt-kneaded to obtain a kneaded product, and then the kneaded product is cooled, solidified and pulverized. Thereafter, particle size adjustment such as classification is performed as necessary to obtain toner particles.
A known apparatus can be used for each step of mixing, melt-kneading, pulverization, and classification.
(3-6)外添剤
 外添剤としては、当該技術分野で常用される外添剤を用いることができ、例えば、シリカ、酸化チタン、炭化ケイ素、酸化アルミニウム、チタン酸バリウムなどが挙げられ、シリコーン樹脂、シランカップリング剤などにより表面処理(疎水化処理)されているものが好ましい。
 本発明においては、上記の外添剤の1種を単独でまたは2種以上を組み合わせて用いることができる。
(3-6) External additive As the external additive, an external additive commonly used in the technical field can be used, and examples thereof include silica, titanium oxide, silicon carbide, aluminum oxide, barium titanate and the like. Those that have been surface treated (hydrophobized) with a silicone resin, a silane coupling agent or the like are preferred.
In the present invention, one of the above external additives may be used alone or in combination of two or more.
 本発明においては、平均粒子径が異なる複数の外添剤を併用するのが好ましい。転写効率の向上の観点から、複数の外添剤のうち少なくとも1種は、0.1μm以上の平均粒子径を有し、複数の外添剤の平均粒子径が0.2μm以下であるのが好ましい。
 例えば、平均粒子径の異なる2種類の外添剤を用いる場合、小さい方が0.007~0.5μmの平均粒子径を有し、大きい方が0.5~0.2μmの平均粒子径を有し、小さい方の平均粒子径と大きい方の平均粒子径との比率が1:5~1:20であるのが好ましい。
In the present invention, it is preferable to use a plurality of external additives having different average particle diameters in combination. From the viewpoint of improving transfer efficiency, at least one of the plurality of external additives has an average particle diameter of 0.1 μm or more, and the average particle diameter of the plurality of external additives is 0.2 μm or less. preferable.
For example, when two types of external additives having different average particle diameters are used, the smaller one has an average particle diameter of 0.007 to 0.5 μm, and the larger one has an average particle diameter of 0.5 to 0.2 μm. The ratio of the smaller average particle diameter to the larger average particle diameter is preferably 1: 5 to 1:20.
 外添剤の添加量は特に限定されないが、トナー母粒子100重量部に対して0.1~3.0重量部であるのが好ましく、0.3~2重量部であるのが特に好ましい。
 外添剤の添加量が上記の範囲内であれば、トナーの各種物性を損なうことなしに、高い画像濃度および画質品位を有する画像を形成することができる。
The amount of the external additive added is not particularly limited, but is preferably 0.1 to 3.0 parts by weight, particularly preferably 0.3 to 2 parts by weight, based on 100 parts by weight of the toner base particles.
When the amount of the external additive is within the above range, an image having a high image density and image quality can be formed without impairing various physical properties of the toner.
(4)画像形成方法
 本発明の2成分現像剤を用いる画像形成方法は、像担持体に潜像を形成する工程と、2成分現像剤を用いて、像担持体に形成された潜像を現像してトナー像を形成する工程とを含み、色再現性をも含めた画像再現性に優れ、高精細かつ高画像濃度の画像を安定的にかつ長期的に形成することができる。
(4) Image Forming Method The image forming method using the two-component developer of the present invention comprises a step of forming a latent image on the image carrier and a latent image formed on the image carrier using the two-component developer. Including a step of developing and forming a toner image, and is excellent in image reproducibility including color reproducibility, and can form a high-definition and high-image density image stably and for a long time.
 以下に製造例、実施例および比較例により本発明を具体的に説明するが、これらの製造例および実施例により本発明が限定されるものではない。
 製造例、実施例および比較例において、各物性値を以下に示す方法により測定した。
The present invention will be specifically described below with reference to production examples, examples and comparative examples, but the present invention is not limited to these production examples and examples.
In Production Examples, Examples and Comparative Examples, each physical property value was measured by the following method.
[キャリア芯材、Baフェライト微粒子および導電性粒子の平均粒子径:μm]
 エーテル型非イオン性界面活性剤(ポリオキシラウリルエーテル、HLB=13.6、花王株式会社製、製品名:エマルゲン109P)の5%水溶液10mLに、測定試料約10~15mgを添加し、超音波分散機(株式会社エスエムテー製、型式:UH-50)を用いて周波数20kHzで1分間分散処理する。得られた分散液約1mLを粒度分布測定装置(日機装株式会社製、型式:マイクロトラックMT3000)で体積粒度分布を測定し、その結果から体積平均粒径を求める。
[Average particle diameter of carrier core material, Ba ferrite fine particles and conductive particles: μm]
About 10 to 15 mg of a measurement sample is added to 10 mL of a 5% aqueous solution of an ether type nonionic surfactant (polyoxylauryl ether, HLB = 13.6, manufactured by Kao Corporation, product name: Emulgen 109P), and ultrasonic waves are added. Dispersion treatment is performed for 1 minute at a frequency of 20 kHz using a disperser (manufactured by SMT Co., Ltd., model: UH-50). About 1 mL of the obtained dispersion is measured with a particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., model: Microtrac MT3000), and the volume average particle size is obtained from the result.
[トナー母粒子の平均粒子径:μm]
 電解液(ベックマン・コールター株式会社製、商品名:ISOTON-II)50mlに、トナー母粒子20mgおよびアルキルエーテル硫酸エステルナトリウム1mlを加え、超音波分散機(株式会社エスエムテー製、型式:UH-50)を用いて周波数20kHzで3分間分散処理する。得られた分散液約1mLを粒度分布測定装置(ベックマン・コールター株式会社製、型式:コールターカウンターMultisizer3)の専用セルに充填した後、1分間撹拌して散乱光強度が安定したことを確認して、アパーチャ径100μm、測定粒子数500000カウントの条件下で体積粒度分布を測定し、その結果から体積平均粒径を求める。
[Average particle diameter of toner base particles: μm]
To 50 ml of electrolyte (Beckman Coulter, trade name: ISOTON-II), 20 mg of toner mother particles and 1 ml of sodium alkyl ether sulfate are added, and an ultrasonic dispersing machine (manufactured by SMT Co., Ltd., model: UH-50) For 3 minutes at a frequency of 20 kHz. About 1 mL of the obtained dispersion was filled into a dedicated cell of a particle size distribution analyzer (Beckman Coulter, Model: Coulter Counter Multisizer 3) and stirred for 1 minute to confirm that the scattered light intensity was stable. The volume particle size distribution is measured under the conditions of an aperture diameter of 100 μm and the number of measured particles of 500,000 counts, and the volume average particle size is obtained from the result.
[ワックスの融点:℃]
 示差走査熱量計(株式会社パーキンエルマージャパン製、型式:Diamond DSC)を用いて、試料0.01gを温度20℃から昇温速度10℃/分で200℃まで加熱し、次いで200℃から20℃に急冷する操作を2回繰返し、DSC曲線を測定する。2回目の操作で測定したDSC曲線の融解に相当する吸熱ピークの温度をワックスの融点とする。
[Melting point of wax: ° C]
Using a differential scanning calorimeter (manufactured by PerkinElmer Japan Co., Ltd., model: Diamond DSC), 0.01 g of a sample is heated from a temperature of 20 ° C. to 200 ° C. at a heating rate of 10 ° C./min, and then from 200 ° C. to 20 ° C. The DSC curve is measured by repeating the rapid cooling operation twice. The endothermic peak temperature corresponding to the melting of the DSC curve measured in the second operation is defined as the melting point of the wax.
[樹脂被覆キャリアの製造]
(樹脂被覆キャリア1)
 被覆樹脂:シリコーン樹脂(信越化学株式会社製、製品名:KR350)の20%トルエン溶液100重量部(樹脂20重量部)、
 磁性微粒子:Baフェライト微粒子(平均粒子径0.8μm、抵抗値108Ω・cm、1000V印加電圧下でも導通しない)30重量部
 導電性微粒子:導電性カーボンブラックトルエン分散液(固形濃度15%、キャボット株式会社製、製品名:VULCAN XC72)5重量部
 カップリング剤:シランカップリング剤(100%溶液、東レ・ダウコーニング株式会社製、製品名:SH6020)4重量部
 溶剤:トルエン100重量部
[Manufacture of resin-coated carriers]
(Resin coated carrier 1)
Coating resin: 100 parts by weight of 20% toluene solution of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR350) (20 parts by weight of resin),
Magnetic fine particles: Ba ferrite fine particles (average particle diameter 0.8 μm, resistance value 10 8 Ω · cm, not conducting even under 1000 V applied voltage) 30 parts by weight Conductive fine particles: conductive carbon black toluene dispersion (solid concentration 15%, 5 parts by weight manufactured by Cabot Corporation, product name: VULCAN XC72 Coupling agent: silane coupling agent (100% solution, manufactured by Toray Dow Corning Co., Ltd., product name: SH6020) 4 parts by weight Solvent: 100 parts by weight of toluene
 上記の成分を含む混合物を汎用撹拌機(神東科学株式会社製、型式:スリーワンモータBLh1200)を用いて、回転数500rpmで5分間攪拌して、コート樹脂液を調製した。得られた被覆樹脂液に、平均粒子径35μmのキャリア芯材(Mn-Mgフェライト)1000重量部を添加混合し、さらに上記の撹拌機を用いて、回転数500rpmで5分間混合した。得られた混合物を減圧(6.0×104Pa程度)および加熱(100℃程度)することにより溶剤のトルエンを除去して、キャリア芯材表面に塗布層を形成した。
 得られた塗布層を有するキャリア芯材を、セーフティーオーブン(エスペック株式会社製、型式:SPH(H)102)を用いて、200℃で1時間加熱して塗布層を硬化させて樹脂層を形成し、100メッシュのふるいにかけて樹脂被覆キャリア(1)(キャリア芯材1000重量部に対して磁性微粒子30重量部)約2000gを得た。
 表1に樹脂被覆キャリア1の各成分とそれらの配合量を示す。
The mixture containing the above components was stirred for 5 minutes at a rotational speed of 500 rpm using a general-purpose stirrer (manufactured by Shinto Kagaku Co., Ltd., model: Three-One Motor BLh1200) to prepare a coating resin solution. 1000 parts by weight of a carrier core material (Mn—Mg ferrite) having an average particle diameter of 35 μm was added to and mixed with the obtained coating resin liquid, and further mixed for 5 minutes at a rotation speed of 500 rpm using the above stirrer. The obtained mixture was depressurized (about 6.0 × 10 4 Pa) and heated (about 100 ° C.) to remove the toluene solvent, thereby forming a coating layer on the surface of the carrier core material.
The obtained carrier core material having the coating layer is heated at 200 ° C. for 1 hour using a safety oven (manufactured by ESPEC Corporation, model: SPH (H) 102) to cure the coating layer to form a resin layer. Then, it was passed through a 100 mesh screen to obtain about 2000 g of resin-coated carrier (1) (30 parts by weight of magnetic fine particles with respect to 1000 parts by weight of carrier core material).
Table 1 shows each component of the resin-coated carrier 1 and the blending amount thereof.
(樹脂被覆キャリア2~15)
 表1に示す樹脂被覆キャリアの各成分とそれらの配合量とすること以外は、樹脂被覆キャリア1と同様にして樹脂被覆キャリア2~15を得た。
 樹脂被覆キャリア2の場合のみ、シリコーン樹脂(表1において(R1)と表記)の20%トルエン溶液の代わりに、アクリル樹脂(スチレン-メタクリル酸メチル共重合体、共重合比20:80、分子量85,000、表1において(R2)と表記)の20%トルエン溶液を用いた。
(Resin coated carriers 2 to 15)
Resin-coated carriers 2 to 15 were obtained in the same manner as the resin-coated carrier 1, except that the respective components of the resin-coated carrier shown in Table 1 and their blending amounts were used.
Only in the case of the resin-coated carrier 2, an acrylic resin (styrene-methyl methacrylate copolymer, copolymerization ratio 20:80, molecular weight 85) instead of a 20% toluene solution of a silicone resin (indicated as (R1) in Table 1). , 000, (indicated as (R2) in Table 1) 20% toluene solution.
 また、磁性微粒子としてBaフェライト微粒子(平均粒子径0.8μm、表1において(B1)と表記)の代わりに、それぞれ下記のように平均粒子径の異なるBaフェライト微粒子(表1において(B2)~(B5)と表記)を用いた。
  Baフェライト微粒子
       (B2):平均粒子径2.0μm、抵抗値109Ω・cm
       (B3):平均粒子径0.1μm、抵抗値107Ω・cm
       (B4):平均粒子径2.5μm、抵抗値108Ω・cm
       (B5):平均粒子径0.08μm、抵抗値108Ω・cm
 なお、Baフェライト微粒子(B1)~(B5)は、1000V印加電圧下でも導通しない。
 表1に樹脂被覆キャリア2~15の各成分とそれらの配合量を示す。
Further, instead of Ba ferrite fine particles (average particle size 0.8 μm, expressed as (B1) in Table 1) as magnetic fine particles, Ba ferrite fine particles ((B2) to (Denoted as (B5)) was used.
Ba ferrite fine particles (B2): average particle diameter 2.0 μm, resistance 10 9 Ω · cm
(B3): average particle diameter 0.1 μm, resistance 10 7 Ω · cm
(B4): Average particle size 2.5 μm, resistance 10 8 Ω · cm
(B5): Average particle diameter 0.08 μm, resistance 10 8 Ω · cm
The Ba ferrite fine particles (B1) to (B5) do not conduct even under an applied voltage of 1000V.
Table 1 shows the components of the resin-coated carriers 2 to 15 and their blending amounts.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
[トナーの製造]
(トナー1)
 結着樹脂:ポリエステル樹脂(酸価21mgKOH/g、芳香族系アルコール成分:PO-BPAとEP-BPA、酸成分:フマル酸と無水メリット酸)                         87.5重量部
 着色剤:C.I.Pigment Blue 15:1    5重量部
 離型剤:無極性パラフィンワックス、融点78℃、重量平均分子量:Mw832)                          6重量部
 荷電制御剤:負帯電サリチル酸系化合物         1.5重量部
[Production of toner]
(Toner 1)
Binder resin: Polyester resin (acid value 21 mgKOH / g, aromatic alcohol component: PO-BPA and EP-BPA, acid component: fumaric acid and merit anhydride) 87.5 parts by weight Colorant: C.I. I. Pigment Blue 15: 1 5 parts by weight Mold release agent: nonpolar paraffin wax, melting point 78 ° C., weight average molecular weight: Mw832) 6 parts by weight Charge control agent: negatively charged salicylic acid compound 1.5 parts by weight
 ヘンシェルミキサを用いて、上記の成分を5分間前混合した後、二軸押出機を用いて、シリンダ設定温度110℃、バレル回転数300rpm、原料供給速度20kg/時間で溶融混練して溶融混練物を得た。
 得られた溶融混練物を、冷却ベルトで冷却させた後、カッテングミルを用いて粗粉砕し、次いでジェット式粉砕機を用いて微粉砕し、さらに風力分級機を用いて分級して、平均粒子径6.5μmのトナー粒子2000gを得た。
The above components are premixed for 5 minutes using a Henschel mixer and then melt kneaded using a twin screw extruder at a cylinder setting temperature of 110 ° C., a barrel rotation speed of 300 rpm, and a raw material supply speed of 20 kg / hour. Got.
After the obtained melt-kneaded product is cooled by a cooling belt, it is coarsely pulverized using a cutting mill, then finely pulverized using a jet type pulverizer, and further classified using an air classifier. 2000 g of toner particles having a diameter of 6.5 μm were obtained.
 次いで、トナー粒子97.8重量%に、i-ブチルトリメトキシシランで疎水化処理されたシリカ微粒子(平均粒子径100nm)1.2重量%と、ヘキサメチルジシラザン(HMDS)で疎水化処理されたシリカ微粒子(平均粒子径12nm)1.0重量%とを加え、ヘンシェルミキサを用いて混合する外添処理を行い、トナー1(シアントナー)2000gを得た。 Next, 97.8% by weight of toner particles were subjected to a hydrophobic treatment with 1.2% by weight of silica fine particles (average particle size 100 nm) hydrophobized with i-butyltrimethoxysilane and hexamethyldisilazane (HMDS). The silica fine particles (average particle diameter: 12 nm) were added in an amount of 1.0% by weight and mixed using a Henschel mixer to obtain 2000 g of toner 1 (cyan toner).
[2成分現像剤の製造とその評価]
(実施例1)
 トナー1と樹脂被覆キャリア1とを混合比トナー濃度8%(トナー/キャリア=1/12.5)になるように組合せ、V型混合機(株式会社徳寿工作所製、型式:V-5)で20分間攪拌混合することにより、実施例1の2成分現像剤2000gを得た。
 得られた2成分現像剤における帯電性、キャリア付着、画質および樹脂層の被覆状態を評価した。
[Production and Evaluation of Two-Component Developer]
(Example 1)
Toner 1 and resin-coated carrier 1 are combined so that the mixing ratio toner concentration is 8% (toner / carrier = 1 / 12.5), and a V-type mixer (manufactured by Tokuju Kogyo Co., Ltd., model: V-5) The mixture was stirred and mixed for 20 minutes to obtain 2000 g of the two-component developer of Example 1.
The chargeability, carrier adhesion, image quality, and coating state of the resin layer in the obtained two-component developer were evaluated.
(実施例2~14および比較例1)
 表2に示すトナーと樹脂被覆キャリアとを組み合わせること以外は、実施例1と同様にして実施例2~14および比較例1~2の2成分現像剤を得て評価した。
(Examples 2 to 14 and Comparative Example 1)
Two-component developers of Examples 2 to 14 and Comparative Examples 1 and 2 were obtained and evaluated in the same manner as in Example 1 except that the toner shown in Table 2 was combined with the resin-coated carrier.
[評価]
(1)帯電性
(1-1)帯電立ち上がり特性
 2成分現像剤の樹脂被覆キャリアとトナーとの組み合わせにおいて、前者の0.95gと後者の0.05gとを容量5mlのガラス瓶に入れ、これを回転培養機(タイテック株式会社製、型式:RT-50)を用いて回転数32rpmで1分間撹拌した。得られた2成分現像剤を採取し、吸引式帯電量測定装置(トレック株式会社製、型式:Model210HS)を用いて帯電量(μC/g)を測定した。また、攪拌時間1分間を3分間にすること以外は同様にして得られた2成分現像剤についても同様にして帯電量(μC/g)を測定した。
 得られた攪拌時間1分間と3分間との帯電量の差の絶対値から、次の基準で帯電立ち上がり特性を評価した。
  ○:良好(帯電量の差が5μC/g以下)
  △:可 (帯電量の差が5μC/gを超えて10μC/g以下)
  ×:不良(帯電量の差が10μC/gを超える)
[Evaluation]
(1) Charging property (1-1) Charging rise characteristic In the combination of a resin-coated carrier of two-component developer and toner, 0.95 g of the former and 0.05 g of the latter are put in a glass bottle with a capacity of 5 ml. The mixture was stirred for 1 minute at a rotational speed of 32 rpm using a rotary incubator (manufactured by Taitec Co., Ltd., model: RT-50). The obtained two-component developer was collected, and the charge amount (μC / g) was measured using a suction type charge amount measuring device (manufactured by Trek Co., Ltd., model: Model 210HS). Further, the charge amount (μC / g) was measured in the same manner for the two-component developer obtained in the same manner except that the stirring time was 1 minute.
From the absolute value of the difference in charge amount between the obtained stirring time of 1 minute and 3 minutes, the charge rising characteristics were evaluated according to the following criteria.
○: Good (charge difference is 5 μC / g or less)
Δ: Acceptable (Charge amount difference exceeds 5 μC / g and 10 μC / g or less)
X: Defect (charge amount difference exceeds 10 μC / g)
(1-2)帯電のライフ特性
 測定用に改造した2成分現像装置を有する市販の複写機(シャープ株式会社製、型式:MX-6000N)に2成分現像剤をセットし、常温常湿(25℃、50%RH)下においてベタ画像を5000枚実写した後、画像部の画像濃度および非画像部の白色度、2成分現像剤の帯電量を測定した。
(1-2) Charging life characteristics A two-component developer is set in a commercially available copying machine (manufactured by Sharp Corporation, model: MX-6000N) having a two-component developing device remodeled for measurement. The image density of the image area, the whiteness of the non-image area, and the charge amount of the two-component developer were measured.
(1-2-1)画像濃度
 分光測色濃度計(日本平版機材株式会社製、型式:X-Rite938)を用いて、画像濃度を測定し、次の基準で評価した。
  ○:良好(画像濃度が1.4以上)
  ×:不良(画像濃度が1.4未満)
(1-2-1) Image Density Image density was measured using a spectrocolorimetric densitometer (manufactured by Nihon Himeki Kaisha, Ltd., model: X-Rite 938), and evaluated according to the following criteria.
○: Good (image density is 1.4 or more)
X: Defect (image density is less than 1.4)
(1-2-2)白色度
 分光式色差計(日本電色工業株式会社製、型式:SZ90型)を用いて、三刺激値X、YおよびZを測定し、得られたZの値から、次の基準で白色度を評価した。
  ○:良好(Zの値が0.5以下)
  △:可 (Zの値が0.5を超えて0.7以下)
  ×:不良(Zの値が0.7を超える)
(1-2-2) Whiteness Using a spectroscopic color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., model: SZ90 type), tristimulus values X, Y and Z are measured, and the obtained Z value is used. The whiteness was evaluated according to the following criteria.
○: Good (Z value is 0.5 or less)
Δ: Acceptable (Z value exceeds 0.5 and is 0.7 or less)
X: Defect (Z value exceeds 0.7)
(1-2-3)帯電量
 吸引式帯電量測定装置(トレック株式会社製、型式:Model210HS)を用いて、帯電量(μC/g)を測定し、初期およびベタ画像5000枚実写後の帯電量を測定し、それらの差の絶対値から、次の基準で帯電量を評価した。
  ○:良好(帯電量の差が5μC/g以下)
  △:可 (帯電量の差が5μC/gを超えて10μC/g以下)
  ×:不良(帯電量の差が10μC/gを超える)
(1-2-3) Charge Amount Charge amount (μC / g) was measured using a suction-type charge amount measuring device (manufactured by Trek Co., Ltd., model: Model 210HS), and charged after initial and 5000 solid images were taken. The amount of charge was measured, and the charge amount was evaluated from the absolute value of the difference according to the following criteria.
○: Good (charge difference is 5 μC / g or less)
Δ: Acceptable (Charge amount difference exceeds 5 μC / g and 10 μC / g or less)
X: Defect (charge amount difference exceeds 10 μC / g)
(2)キャリア付着
 上記の複写機に2成分現像剤をセットし、像担持体上の非画像部における一定面積(297mm×24mm)中のキャリア付着個数を計数した。この際、直流バイアス電圧200V、交流バイアス電圧1100Vおよび周波数9kHzを現像剤担持体に印加し、像担持体の表面には帯電させなかった。得られたキャリア付着個数から、次の基準でキャリア付着を評価した。
  ○:良好(キャリア付着個数が15個未満)
  △:可 (キャリア付着個数が15個以上20個以下)
  ×:不良(キャリア付着個数が20個を超える)
(2) Carrier adhesion A two-component developer was set in the copying machine, and the number of carriers adhered in a fixed area (297 mm × 24 mm) in the non-image area on the image carrier was counted. At this time, a DC bias voltage of 200 V, an AC bias voltage of 1100 V, and a frequency of 9 kHz were applied to the developer carrier, and the surface of the image carrier was not charged. Carrier adhesion was evaluated from the obtained carrier adhesion number according to the following criteria.
○: Good (number of carriers attached is less than 15)
Δ: Possible (Number of carriers attached is 15 or more and 20 or less)
X: Defect (number of carriers attached exceeds 20)
(3)画質
 上記の複写機に2成分現像剤をセットし、画像のテストチャートを印刷して、白色との色差が30、50および70における粒状性のスコア値を、自動プリンタ画質評価システム(王子計測機器株式会社製、型式:APQS)を用いて測定した。得られたスコア値の最大値から、次の基準で画質(粒状性)を評価した。なお、スコア値が低いほど画像のざらつきが少なく、高画質であることを示す。
  ○(良好):スコア値の最大値が11500未満
  △(可) :スコア値の最大値が11500以上12000以下
  ×(不良):スコア値の最大値が12000を超える
(3) Image quality A two-component developer is set in the above-mentioned copying machine, an image test chart is printed, and a granularity score value when the color difference from white is 30, 50, and 70 is calculated using an automatic printer image quality evaluation system ( Measurement was performed using Oji Scientific Instruments Co., Ltd., model: APQS). The image quality (granularity) was evaluated from the maximum score value obtained according to the following criteria. Note that the lower the score value, the less the roughness of the image and the higher the image quality.
○ (good): Maximum score value is less than 11500 Δ (possible): Maximum score value is 11500 or more and 12000 or less × (Poor): Maximum score value is more than 12000
(4)樹脂層の被覆状態
 表1に示す製造直後の樹脂被覆キャリアを電子顕微鏡(倍率1000)で観察し、樹脂層の状態を観察した。
 また、(1-2)帯電のライフ特性の試験後の2成分現像剤から樹脂被覆キャリアを取り出し、(倍率1000)で観察し、樹脂層の状態を観察した。
 製造時と対比した試験後の樹脂被覆キャリアの状態から、次の基準で樹脂層の状態を評価した。
  ○(良好):樹脂層の変化が少ない
  △(やや劣る):実使用には耐え得る程度であるが、キャリア芯材の露出部分が少し観察される
  ×(不良):樹脂層が明らかに摩耗し、キャリア芯材の露出部分が多い
(4) Covering state of resin layer The resin-coated carrier immediately after production shown in Table 1 was observed with an electron microscope (magnification 1000), and the state of the resin layer was observed.
Also, (1-2) the resin-coated carrier was taken out of the two-component developer after the test of the charge life characteristics, and observed at (magnification 1000) to observe the state of the resin layer.
The state of the resin layer was evaluated according to the following criteria from the state of the resin-coated carrier after the test compared with the time of manufacture.
○ (Good): Little change in the resin layer Δ (Slightly inferior): Although it can withstand actual use, the exposed part of the carrier core is slightly observed. X (Bad): The resin layer is clearly worn And there are many exposed parts of the carrier core
(5)総合評価
 上記(1)~(4)の評価結果に基づいて、次の基準で総合評価を行った。
  ◎:すべての評価項目について○
  ○:1つの評価項目にでも△がある
  ×:1つの評価項目にでも×がある
 表2に2成分現像剤の各成分とそれらの混合比および評価結果を示す。
(5) Comprehensive evaluation Based on the evaluation results (1) to (4) above, comprehensive evaluation was performed according to the following criteria.
◎: For all evaluation items ○
○: There is Δ even in one evaluation item ×: There is × in one evaluation item Table 2 shows each component of the two-component developer, a mixing ratio thereof, and an evaluation result.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
 表2の結果によれば、本発明のキャリアを含有するトナー(実施例1~14)は、帯電性、キャリア付着、画質および樹脂層の被覆状態、特にライフ特性が良好であることがわかる。
 一方、Baフェライト微粒子を樹脂層に含まないキャリアを含有するトナー(比較例1)は、帯電性、キャリア付着、画質および樹脂層の被覆状態、特にライフ特性に劣ることがわかる。
According to the results of Table 2, it can be seen that the toners (Examples 1 to 14) containing the carrier of the present invention have good chargeability, carrier adhesion, image quality, and coating state of the resin layer, particularly life characteristics.
On the other hand, it can be seen that the toner containing a carrier containing no Ba ferrite fine particles in the resin layer (Comparative Example 1) is inferior in chargeability, carrier adhesion, image quality, and coating state of the resin layer, particularly in life characteristics.
 1 測定冶具
 2 磁石
 3 電極
 4 基盤
1 Measuring jig 2 Magnet 3 Electrode 4 Base

Claims (5)

  1.  フェライトからなるキャリア芯材と、前記キャリア芯材を被覆し、かつ磁性微粒子として1000V印加電圧下で導通せずかつ107~109Ω・cmの抵抗値を有するバリウムフェライト微粒子を含む樹脂層とで構成されることを特徴とする電子写真用キャリア。 A carrier core material made of ferrite, and a resin layer that covers the carrier core material and contains barium ferrite fine particles that do not conduct as magnetic fine particles under an applied voltage of 1000 V and have a resistance value of 10 7 to 10 9 Ω · cm. An electrophotographic carrier comprising:
  2.  前記バリウムフェライト微粒子が、0.08~0.8μmの体積平均粒子径を有する請求項1に記載の電子写真用キャリア。 2. The electrophotographic carrier according to claim 1, wherein the barium ferrite fine particles have a volume average particle diameter of 0.08 to 0.8 μm.
  3.  前記バリウムフェライト微粒子が、キャリア芯材1000重量部に対して0.05~65重量部の割合で含まれる請求項1または2に記載の電子写真用キャリア。 3. The electrophotographic carrier according to claim 1, wherein the barium ferrite fine particles are contained in an amount of 0.05 to 65 parts by weight with respect to 1000 parts by weight of the carrier core material.
  4.  前記樹脂層が、導電性微粒子をさらに含む請求項1~3のいずれか1つに記載の電子写真用キャリア。 The carrier for electrophotography according to any one of claims 1 to 3, wherein the resin layer further contains conductive fine particles.
  5.  請求項1~4のいずれか1つに記載の電子写真用キャリアとトナーとを含むことを特徴とする2成分現像剤。 A two-component developer comprising the electrophotographic carrier according to any one of claims 1 to 4 and a toner.
PCT/JP2013/055205 2012-03-01 2013-02-27 Electrophotography carrier, and two-component developer containing same WO2013129507A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61296363A (en) * 1985-06-26 1986-12-27 Mitsubishi Chem Ind Ltd Coated carrier for electrophotography
JPH10282728A (en) * 1997-04-08 1998-10-23 Ricoh Co Ltd Developer
JP2000098666A (en) * 1998-09-25 2000-04-07 Fuji Xerox Co Ltd Coated carrier for development of electrostatic latent image, developer for electrostatic latent image and image forming method
JP2001051456A (en) * 1999-08-10 2001-02-23 Fuji Xerox Co Ltd Electrostatic latent image developing carrier
JP2002229273A (en) * 2001-01-29 2002-08-14 Ricoh Co Ltd Carrier for electrophotographic developer and developer
JP2007033631A (en) * 2005-07-25 2007-02-08 Sharp Corp Carrier and two-component developer
JP2012083389A (en) * 2010-10-06 2012-04-26 Sharp Corp Resin coated carrier and two-component developer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61296363A (en) * 1985-06-26 1986-12-27 Mitsubishi Chem Ind Ltd Coated carrier for electrophotography
JPH10282728A (en) * 1997-04-08 1998-10-23 Ricoh Co Ltd Developer
JP2000098666A (en) * 1998-09-25 2000-04-07 Fuji Xerox Co Ltd Coated carrier for development of electrostatic latent image, developer for electrostatic latent image and image forming method
JP2001051456A (en) * 1999-08-10 2001-02-23 Fuji Xerox Co Ltd Electrostatic latent image developing carrier
JP2002229273A (en) * 2001-01-29 2002-08-14 Ricoh Co Ltd Carrier for electrophotographic developer and developer
JP2007033631A (en) * 2005-07-25 2007-02-08 Sharp Corp Carrier and two-component developer
JP2012083389A (en) * 2010-10-06 2012-04-26 Sharp Corp Resin coated carrier and two-component developer

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