JP2008304838A - Two-component developer for electrostatic charge image development, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress image deletion, image defects resulting from a discharge product, such as a streak defect, and lowering of print density and toner fogging attended with the deterioration of a developing unit, even in high-speed printing over a long period of time. <P>SOLUTION: A two-component developer for electrostatic charge image development is provided, which is used in a two-component developing device for electrostatic charge image development using a developing method by which a magnetic brush by a developer is formed on a developing sleeve 26 having magnetism to develop an electrostatic latent image, wherein the developing sleeve 26 is operated at a peripheral velocity of 350-1,000 mm/s. The two-component developer includes toner 34 including at least a binder resin and a color material, a carrier 32 including at least a magnetic carrier core material and a resin, and a lubricant 38 or silicone oil-treated inorganic fine particles 36 or both the lubricant 38 and the silicone oil-treated inorganic fine particles 36, wherein zeolite particles subjected to coupling treatment are dry-deposited on the surface of the carrier 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a two-component developer for developing an electrostatic image and an image forming apparatus.

  In image forming apparatuses such as copying machines and printers using electrophotographic technology, a charging process for charging the surface of a photosensitive member as an electrostatic latent image (electrostatic charge) carrier, and image light is exposed to the surface of the charged photosensitive member. An exposure step for forming an electrostatic latent image, a development step for forming a toner image by attaching an electrostatic charge image developing toner (hereinafter sometimes referred to simply as “toner”) to the electrostatic latent image, and a toner. A transfer process in which an image is transferred to a transfer medium such as paper through an intermediate transfer body or by direct transfer, a fixing process in which a toner image on the transfer medium such as paper is fixed, and a transfer process. An image is formed by a series of processes called a cleaning process for removing toner and foreign matters remaining on the toner. Developers used for development include a two-component developer composed of a toner and a carrier, and a one-component developer used alone, such as a magnetic toner, and the two-component developer includes a carrier as a developer. Since the functions such as agitation, conveyance and charging are shared and the functions are separated as a developer, the controllability is good, and it is widely used at present. A two-component developing device (hereinafter referred to as a developing device) has a wide variety of methods for developing and developing a toner surface latent image through a magnetic cylindrical sleeve by charging the developer composed of the toner and the carrier with stirring and mixing. It is used.

  In the charging process in which the surface of the photoreceptor is charged by applying a high electric field, discharge products such as nitrogen oxides and ammoniums are likely to be generated due to discharge of moisture, air, etc., and are particularly remarkable under high humidity. The generated discharge product adheres to the surface of the photoconductor to form filming (fixed material) on the surface of the photoconductor, which causes charging and electrostatic latent image formation defects, resulting in an image formed on the transfer target. May cause image defects such as image flow and streak defects.

  Such an image defect can be avoided by removing the discharge product together with the residual toner in the cleaning process. However, in order to remove discharge products with a cleaning member such as a blade or brush, it is necessary to apply strong rubbing, which leads to a decrease in the life of the photoconductor due to wear on the surface of the photoconductor. From the point of view, it is not optimal.

  Therefore, it is expected that image defects can be avoided while suppressing wear on the surface of the photoreceptor, if the discharge product can be removed by using a chemical action instead of strong physical rubbing.

  For example, Patent Document 1 discloses a method of removing a discharge product by bringing a polar adsorbent into contact with the surface of a photoconductor. For example, the polar adsorbent is supplied to a brush-like cleaning device to remove the surface of the photoconductor. Although rubbing is described, it is not necessarily optimal from the viewpoint of increasing the number of parts and space.

  Patent Document 2 describes mixing a polar adsorbent with a developer in order to remove a discharge product by bringing the polar adsorbent into contact with the surface of the photoreceptor. Patent Document 3 discloses a method in which a polar adsorbent is contained in a two-component developer carrier and used as discharge product removal particles. In this method, since the activity of the polar adsorbent is reduced by coating, it is difficult to obtain a sufficient adsorption capacity.

  On the other hand, Patent Document 4 discloses a configuration in which powders such as activated carbon, inorganic gel, and zeolite are added to a developer or externally added to a toner for the purpose of deodorization. In the method of adding directly into the developer, these additives have low chargeability, there is a problem in the durability of the effect due to the blowout from the inside of the developing device, and the toner is discharged from the developing device due to the adverse effect on the toner charging property. Problems such as jetting are also likely to occur.

  Further, as the output speed of copiers and printers increases in recent years, the developing sleeve of the developing unit is subjected to loads such as an increase in peripheral speed and an increase in internal stress in order to follow the toner supply. As a result, there are problems of image quality problems such as developer transportability due to deterioration of the sleeve surface and the magnetic brush control member, output image density reduction due to poor mixing, and toner fog on non-image areas.

JP 2003-005601 A Japanese Patent Laid-Open No. 2003-091223 Japanese Patent Application Laid-Open No. 2003-0666808 Japanese Patent Laid-Open No. 04-338970

  The main purpose of the present invention is that image flow even during high-speed printing, image defects due to discharge products such as streak defects, print density reduction due to developing device deterioration, and occurrence of image quality troubles such as toner fog Is a carrier for developing an electrostatic charge image and a two-component developer for developing an electrostatic charge image.

  The present invention is as follows.

  (1) Static using a developing method in which a magnetic brush is formed by a developer on a developing sleeve having magnetic force to develop an electrostatic latent image, and the developing sleeve is operated at a peripheral speed of 350 mm / s to 1000 mm / s. An electrostatic charge image developing two-component developer used in a charge image developing two-component developing device, wherein the electrostatic charge image developing two-component developer includes a toner including a binder resin and a coloring material, and a magnetic carrier. Two-component for electrostatic image development, comprising a carrier containing a core material and a resin, and a lubricant or silicone oil or both a lubricant and silicone oil, wherein the surface of the carrier is attached with coupled zeolite particles Developer.

  (2) The two-component developer for developing an electrostatic charge image according to (1), wherein the coupling treatment is a silane coupling treatment.

  (3) The two-component developer for developing an electrostatic charge image according to the above (1), wherein the lubricant is a higher-component alcohol.

  (4) The two-component developer for developing an electrostatic charge image according to (1) above, wherein the lubricant is a fatty acid metal salt.

  (5) The two-component developer for developing an electrostatic charge image according to the above (1), wherein the silicone oil is supported on inorganic fine particles and contained as inorganic particles treated with silicone oil. It is.

  (6) The two-component developer for developing an electrostatic charge image according to (5), wherein the inorganic fine particles are silica.

  (7) a latent image forming means for forming a latent image on the latent image carrier; a developing means for developing the latent image using a developer for developing electrostatic charge; and the developed toner image via an intermediate transfer member. Alternatively, the image forming apparatus includes: a transfer unit that transfers the toner image on the transfer body without being interposed; and a fixing unit that adds and fixes the toner image on the transfer body. An image forming apparatus which is the two-component developer for developing an electrostatic charge image according to any one of 1) to (6).

  According to the invention of claim 1 of the present application, the zeolite particles present on the surface of the carrier rub against the surface of the photoconductor via the carrier conveyed by magnetic force on the developing sleeve, so that image defects such as image flow can be prevented. It is possible to effectively adsorb and remove the discharge products generated on the surface of the photosensitive member.

  Further, according to the first aspect of the present invention, since the developer contains a lubricant or silicone oil, a decrease in print density and a toner fog that occur gradually due to a high developing sleeve peripheral speed or deterioration of the developing device due to long-term use. It was discovered that image quality problems such as The reason for this is not fully understood, but it is thought to be as follows.

  That is, these image quality troubles are due to the deterioration of the wear of the surface of the developing sleeve and the magnetic brush forming member (trimmer member) in the developing device. The deterioration of the developing sleeve reduces the conveyance and changeability of the developer, and the desired development. It becomes difficult to supply a sufficient toner for obtaining the density to the surface of the photoreceptor. In addition, the deterioration of the magnetic brush forming member hinders normal magnetic brush formation and easily causes development failure. It is considered that the deterioration in the developing device is triggered to cause image quality troubles such as density reduction and toner fog.

  In response to the above problems, the lubricant or silicone oil according to the present invention forms a lubricating layer on the surface of the developing sleeve and the surface of the magnetic brush forming member through the zeolite particles on the surface of the carrier, thereby reducing the wear of the member. It is considered that the effect of the present invention was generated.

  Furthermore, according to the invention according to claim 2 of the present application, the affinity between the zeolite particles and the carrier surface is achieved by adopting a structure in which the zeolite particles subjected to silane coupling treatment, for example, alkylsilane coupling treatment, are dry-adhered to the carrier surface. Therefore, even under the above-described high sleeve peripheral speed, dropping of zeolite is suppressed, and the effect of removing discharge products is maintained over a long period of time.

  As described above, according to the present invention, the structure in which the zeolite particles are dry-attached to the surface of the carrier and the developer contains a lubricant or silicone oil allows image flow and streak even during high-speed printing. It is possible to suppress the occurrence of image defects such as image defects such as image defects and image quality problems such as print density reduction and toner fog due to deterioration of the developing device.

  Embodiments of the present invention will be described below.

<Developer for developing electrostatic image>
The developer for developing an electrostatic image according to the exemplary embodiment is a two-component developer including a toner and a carrier. Here, the “two-component developer for developing an electrostatic image” in the present embodiment may be abbreviated as “developer” hereinafter.

<Toner>
The toner is a powder material for image formation containing at least a binder resin and a colorant. If necessary, a release agent, generally added as fine particles called an external additive, is used.

  Examples of toner binder resins include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, methyl acrylate, and ethyl acrylate. , Esters of α-methylene aliphatic monocarboxylic acids such as butyl acrylate, decyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate; vinyl methyl ether, vinyl Specific examples include vinyl ethers such as ethyl ether and vinyl butyl ether; homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone. Examples of the binder resin include polystyrene, styrene / alkyl acrylate copolymer, styrene / alkyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyethylene. And polypropylene. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin waxes and the like.

  Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brillianthamine 3B, and brillianthamine. 6B, DuPont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, etc. Or acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thio Various dyes such as Ndico, Dioxazine, Thiazine, Azomethine, Indico, Thioindico, Phthalocyanine, Aniline Black, Polymethine, Triphenylmethane, Diphenylmethane, Thiazine, Thiazole, and Xanthene Or in combination of two or more.

  In the toner according to the exemplary embodiment, the content of the colorant is preferably in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the toner binder resin. It is also effective to use a processed colorant or a pigment dispersant. By appropriately selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner and the like can be obtained.

  Examples of mold release agents include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point upon heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide; Plant waxes such as ester wax, carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, etc .; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, fisher Mineral waxes such as Tropsch wax, petroleum waxes, and modified products thereof can be used. The addition amount of the release agent can be added in the range of 50% by weight or less with respect to the toner. Although depending on the inherent properties of the material such as the hardness of the release agent, it is not preferable that the amount is 50% by weight or more because the toner tends to be deformed or fixed as the use is reduced.

  Other materials added to the toner include magnetic materials such as ferrite, magnetite, reduced iron, cobalt, nickel, manganese, alloys thereof, compounds containing these metals, silica, alumina, titania, calcium carbonate, etc. Metal oxides can be used. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salts, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. In order to control the ionic strength that affects the stability at the time of aggregation and fusion integration and to reduce wastewater contamination, a charge control agent that is difficult to dissolve in water is preferable.

  Examples of the external additive include known external additives such as inorganic particles and organic particles. Among them, silica, titania, alumina, cerium oxide, strontium titanate, calcium carbonate, magnesium carbonate, and phosphorus can be used. Organic particles such as inorganic particles such as calcium oxide, metal soap such as zinc stearate, fluorine-containing resin particles, silica-containing resin particles, and nitrogen-containing resin particles are preferred. Further, the surface of the external additive may be subjected to a surface treatment according to the purpose.

  The volume average particle size of the toner according to the exemplary embodiment is preferably in the range of 4 μm to 13 μm, more preferably in the range of 5 μm to 10 μm, and the number average particle size is preferably in the range of 3 μm to 9 μm. The range of 6 μm is more preferable.

  The volume average particle size and the number average particle size can be measured by measuring with a multisizer type II (manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm. At this time, the measurement is performed after the particles to be measured, here the toner, are dispersed in an electrolyte aqueous solution (isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds. When the measurement particles are hydrophobic, a few drops of a 10% by weight aqueous sodium dodecylbenzenesulfonate solution are dropped into the electrolyte solution until the measurement particles become familiar, and then ultrasonic dispersion is performed for an additional 30 seconds to perform measurement. .

  In addition, the volume average particle size distribution index GSDv of the toner according to the exemplary embodiment is preferably 1.27 or less, and more preferably 1.25 or less. When GSDv exceeds 1.27, the particle size distribution is not sharp, resolution is deteriorated, and image defects such as toner scattering and fogging are caused.

  The volume average particle diameter D50v and the volume average particle size distribution index GSDv can be obtained as follows. For the particle size range (channel) divided based on the particle size distribution of the toner measured by the above-mentioned Multisizer II type (manufactured by Beckman Coulter, Inc.) The particle size that is 16% cumulative is defined as volume D16v and several D16p, the particle size that is cumulative 50% is defined as volume D50v and several D50p, and the particle size that is cumulative 84% is defined as volume D84v and several D84p. At this time, D50v represents the volume average particle diameter, and the volume average particle size distribution index (GSDv) is obtained as (D84v / D16v) 1/2. In addition, (D84p / D16p) 1/2 represents a number average particle size distribution index (GSDp).

  The toner charge amount is preferably 10 to 70 μC / g, more preferably 15 to 50 μC in absolute value, although it depends on the particle size of the toner and carrier, material, material composition, toner carrier mixing ratio, developing device structure and developing mechanism. / g. If it is less than 10 μC / g, fogging and toner scattering are likely to occur, and if it is 70 μC / g or more, a sufficient print density may not be obtained.

  The toner charge amount is blown off in a room adjusted to an air temperature of 25 ° C. and a humidity of 55% by mixing 40 g of toner conditioned and humidified for 24 hours or more and 500 g of carrier in a V-type blender at 40 rpm for 20 minutes. It is the value measured with a charge amount measuring device (Toshiba Chemical Co., Ltd .: TB200).

<Career>
The carrier used in the present embodiment has the zeolite particles subjected to the coupling treatment dry-attached on the surface thereof, and the other configuration may be the same as or similar to the conventionally known electrophotographic carrier. It is not limited.

  In order to achieve the configuration of the present embodiment to be described later, an inorganic compound such as magnetic ferrite and iron powder is used as a magnetic carrier core material, and at least a resin component is included for the purpose of resistance adjustment and charge adjustment, and resin A magnetic powder-dispersed carrier in which fine particles are used as a matrix and magnetic fine particles are internally added is preferable.

<Magnetic carrier core material>
As the carrier core material and the magnetic fine particles, any conventionally known materials can be used, but ferrite and magnetite are particularly preferably selected. For example, iron powder is known as another carrier core material. In the case of iron powder, since the specific gravity is large and the toner is likely to be deteriorated, ferrite and magnetite are more stable. An example of ferrite is generally represented by the following formula.

(MO) X (Fe ₂ O ₃ ) Y
(In the formula, M contains at least one selected from Cu, Zn, Fe, Mg, Mn, Ca, Li, Ti, Ni, Sn, Sr, Al, Ba, Co, Mo, etc. X, Y represents a weight mol ratio and satisfies the condition X + Y = 100).

As a raw material of the carrier core material, Fe ₂ O ₃ is an essential component, and magnetic particles used include ferromagnetic iron oxide particles such as magnetite and maghemite, metals other than iron (Mn, Ni, Zn, Mg, Spinel ferrite particle powder containing one or more of Cu, etc., magnet plumbite type ferrite particle powder such as barium ferrite, and iron or iron alloy particle powder having an oxide film on the surface thereof can be used.

<Carrier resin>
The resin contained in the carrier of the present invention is a polyolefin resin such as polyethylene, polypropylene; polyvinyl and polyvinylidene resin such as polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole. , Polyvinyl ether and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer; styrene-acrylic copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; fluororesin such as polytetrafluoroethylene, polyvinyl fluoride, Polyvinylidene fluoride, polychlorotrifluoroethylene; polyester; polyurethane; polycarbonate, amino resin, such as urea-formaldehyde resin ; It is possible to use an epoxy resin or the like. These may be used alone or in combination with a plurality of resins.

  Among them, a polymer or copolymer of at least one monomer selected from styrene, acrylic acid ester and methacrylic acid ester is preferable. Specifically, polymers such as polystyrene, polymethyl methacrylate and polybutyl acrylate, and copolymers such as styrene-methyl methacrylate and styrene-ethyl methacrylate. These thermoplastic resins are preferable because they are excellent in chargeability and zeolite particle retention.

  Mixing of the carrier core material and the resin for carrier is performed by spraying on the surface of the carrier core material, fluidized bed method in which the solution for forming the resin coating layer is sprayed in a state where the carrier core material is suspended by flowing air, in a kneader coater. Examples of the kneader coater method and dry coating method in which the carrier core material and the resin coating layer forming solution are mixed and then the solvent is removed include a powder coating method in which the resin fine particles and the carrier core material are overheated and coated. .

<Zeolite particles>
Zeolite is also called zeolite and has the general formula MxO.Al ₂ O ₃ .ySiO ₂ .zH ₂ O.
(M is a metal element, x, y, and z are integers)
It is an alkali (earth) metal salt of crystalline hydrous aluminosilicate represented by

  Zeolite has an ion exchange capacity and a property of holding water reversibly, and is widely used as an adsorbent, a humidity control agent, an ion exchange material, and the like. Further, there are roughly classified natural zeolite obtained as a mineral resource, synthetic zeolite synthesized using silica, alumina and the like as raw materials, and artificial zeolite obtained by treating lime ash and the like. Although there is no restriction | limiting in particular as a zeolite used by this embodiment, The synthetic zeolite or artificial zeolite excellent in adsorption | suction performance, ion exchange ability, etc. is preferable. Specific examples include Zeolum (manufactured by Tosoh Corporation), HSZ series (manufactured by Tosoh Corporation), Zeostar (manufactured by Nippon Chemical Industry Co., Ltd.), and Cyculus (manufactured by Chubu Electric Power Co., Inc.).

  The addition amount of the zeolite particles is preferably in the range of 0.05 to 5.0% by weight, more preferably in the range of 0.1 to 1.0% by weight based on the total weight of the carrier. If the amount of zeolite added is less than 0.05% by weight, the above effect may not be obtained, and if it exceeds 5.0% by weight, the charge imparting property to the toner, which is the original function of the carrier, may be reduced. Absent.

  Examples of the material exhibiting an adsorption action similar to zeolite include light-colored adsorbent particles such as sepiolite and hydroxyapatite.

<Coupling agent>
Examples of the coupling agent used in the present invention include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together. Of these, silane coupling agents are preferred.

  As the silane coupling agent, any type of chlorosilane, alkoxysilane, silazane, and special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N-bis (Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxy Silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

  Examples of the titanate coupling agent include “Plenact KR TTS”, “Plenact KR 46B”, “Plenact KR 55”, “Plenact KR 41B”, “Plenact KR 38S”, “Plenact KR 138S”, “Plenact KR” , “Plenact KR 44”, “Plenact KR 9SA”, and “Plenact KR ET” (all of which are manufactured by Ajinomoto Fine Techno Co., Ltd.). Examples of the aluminum coupling agent include alkyl aceto Examples thereof include acetate aluminum diisopropylate (“Plenact AL-M” manufactured by Ajinomoto Fine Techno Co., Ltd.).

<Silicone oil>
Examples of the silicone oil added to the developer of the present embodiment include dimethyl syl corn oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, methyl phenyl silicone oil, cyclic dimethyl silicone oil, epoxy-modified silicone oil, and carboxyl-modified silicone. Known oils such as oil, carbinol-modified silicone oil, methacryl-modified silicone oil, mercapto-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, alkyl-modified silicone oil, and fluorine-modified silicone oil can be used. Of these, dimethyl silicone oil is preferred.

<Adding silicone oil supported on inorganic fine particles>
The silicone oil added to the developer in the present embodiment is mixed with inorganic fine particles from the viewpoint of maintaining effect, fluidity in the developer, and dispersibility. It is preferably used in a supported form. Examples of inorganic fine particles include carbon black, silica, alumina, titania, zinc oxide, cerium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, cerium chloride, bengara, chromium oxide, antimony trioxide, and oxide. Examples thereof include magnesium, zirconium oxide, silicon carbide, silicon nitride, and calcium carbonate. Of these, the use of silica is particularly effective. From the viewpoint of developer charge control and fluidity, the number average particle size of the inorganic fine particles is suitably 10 to 500 nm. The number average particle diameter of the inorganic fine particles was determined from the average value of 100 particle radii by converting the particle image observed with an electron microscope into a spherical shape by image processing.

  In the present embodiment, silicone oil can be used by adding to inorganic fine particles, and can be used by mixing with silicone oil in an amount of 0.2 to 20.0 parts by weight with respect to 100 parts by weight of inorganic fine particles. .

  The inorganic fine particles treated with silicone oil are preferably added in an amount of 0.3 to 3.0 parts by weight with respect to 100 parts by weight of the developer.

<Lubricant>
In this embodiment, the lubricant added to the developer refers to a powder that imparts solid lubricity at room temperature. Specific examples include higher alcohols and fatty acid metal salts.

  As the higher alcohol, those having a melting point of 45 to 130 ° C. and a carbon number of 10 to 60 are preferable. Specific examples include cetyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol, aralkyl alcohol, and behenyl alcohol. These may be pure substances, mixtures having a carbon number distribution, or those containing functional groups such as hydrocarbons having no alcohol terminal, carboxylic acids, amino groups, etc. as impurities. It may be processed or otherwise modified. The volume average particle diameter of the higher alcohol of the present invention is 3 μm or more and 20 μm or less, preferably 5 μm or more and 15 μm or less. The volume average particle diameter can be determined by the same method as the toner particle measuring method described above.

  The higher alcohol is added in an amount of 0.2 to 3.0 parts by weight with respect to 100 parts by weight of the developer.

  The fatty acid metal salt is preferably in the form of a solid at normal temperature, and includes higher fatty acid metal salts. Specific examples include metal stearates such as zinc stearate, aluminum stearate, copper stearate and magnesium stearate, zinc oleate, manganese oleate, iron oleate, copper oleate and magnesium oleate. Metal salts, metal palmitates such as zinc palmitate, copper palmitate, magnesium palmitate, metal linoleate such as zinc linoleate and zinc linoleate, metal ricinoleate such as zinc ricinoleate and lithium ricinoleate, etc. Can be mentioned.

  The fatty acid metal salt is preferably added in an amount of 0.2 to 3.0 parts by weight with respect to 100 parts by weight of the developer. The fatty acid metal salt of the present invention is used in powder form, and the volume average particle size is 3 μm or more and 50 μm or less, preferably 5 μm or more and 20 μm or less. The volume average particle diameter can be determined by the same method as the toner particle measuring method described above.

<Dry adhesion>
The method for producing a carrier for developing an electrostatic charge image contained in the developer according to the present embodiment includes a resin on the surface of a magnetic powder-dispersed carrier or magnetic carrier core material in which magnetic fine particles are internally added using the resin fine particles described above as a matrix. Production by mixing resin-coated carrier with a coating layer and zeolite particles, and applying the shear force while stirring the mixed mixture to attach the zeolite particles to the surface of the above-mentioned magnetic powder-dispersed carrier or resin-coated carrier The method is preferred. By this method, it is possible to obtain a structure in which zeolite particles are attached to the surface of the above-described magnetic powder-dispersed carrier or resin-coated carrier, that is, a structure in which part of the zeolite particles are embedded in the magnetic powder-dispersed carrier or the coated resin layer. . As the dry processing apparatus, it is preferable to use a dry combined processing apparatus capable of applying not only a mixing stirring force but also a shearing force. Specifically, for example, an apparatus such as Nobilta (manufactured by Hosokawa Micron) is suitable for achieving the adhesion structure of this embodiment.

<Dry adhesion structure>
In the present embodiment, the “adhesion” of the zeolite particles is different from the structure in which the particles are not adhered to the surface of the carrier (hereinafter referred to as carrier mother particles) before the adhesion treatment and are magnetic as shown in FIG. In the powder dispersion type carrier, it means a state in which a part of the zeolite particles 2 in the carrier 1 is partly embedded and fixed on the surface of the carrier base particles 3. That is, the attachment state of the zeolite particles to the surface of the carrier base particles 3 is different from the state of being easily detached from the surface of the carrier base particles 3.

  Similarly, in the resin-coated carrier shown in FIG. 2, “adhesion” of zeolite particles means that a part of the zeolite particles 2 in the carrier 1 is on the surface of the resin-coated layer 4 formed on the surface of the magnetic carrier core material 5. A state where a part is buried and fixed. That is, the attachment state of the zeolite particles to the surface of the resin coating layer 4 is different from the state in which the zeolite particles are easily detached from the surface of the resin coating layer 4.

  In the case of the resin-coated carrier in which a resin coating layer is formed on the surface of the magnetic powder-dispersed carrier shown in FIG. 1, the “adhesion” of the zeolite particles means that a part of the zeolite particles is the surface of the magnetic powder-dispersed carrier. The state where a part of the resin coating layer is embedded and fixed on the surface of the resin coating layer, and the adhesion state of the zeolite particles to the resin coating layer surface is easily detached from the surface of the resin coating layer. It is different from the state to do.

  The confirmation of the state in which the zeolite particles 2 are attached to the surface of the carrier base particles 3 and the state in which the zeolite particles 2 are attached to the surface of the resin coating layer 4 in the present embodiment is shown in FIGS. When the carrier in the form is washed and removed by the following treatment, the ratio of the number of zeolite particles adhering per 50 carriers observed with a scanning electron microscope (SEM) and the number after treatment is confirmed. Can do.

  The ratio of the number after treatment to the number before treatment is obtained as an adhesion rate (%), and “attachment” in the present invention indicates a state where the adhesion rate is 60% or more.

  The above-described cleaning removal processing method will be described below. 5 g of carrier according to this embodiment, 100 g of ion-exchanged water, and 0.5 g of sodium dodecylbenzenesulfonate are placed in a 200 mL beaker, and the beaker is dispersed for 5 minutes with an ultrasonic cleaner (USK-4A: manufactured by ASONE Corporation). After processing, a magnet is attached to the bottom of the beaker so that the magnetic powder does not flow out, the carrier is fixed, the supernatant is removed, and then the carrier is air-dried to obtain a washed carrier (treated carrier).

  When zeolite particles are present inside the carrier base particles, or when, for example, a resin component, zeolite particles and a solvent are mixed to form a resin coating layer forming solution, and the carrier core material is coated, or the carrier core material is coated If the resin coating layer contains zeolite, the function of the zeolite cannot be sufficiently exerted, and the effect of removing the discharge product is weak.

  In addition, when zeolite particles are simply added as an external additive and the zeolite particles do not adhere to the carrier surface and are released, the zeolite particles are detached and released over time, and the surface of the photoreceptor is not sufficiently rubbed. This is not preferable.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes a charging unit that charges the surface of the electrostatic charge image carrier and exposure that forms an electrostatic latent image (electrostatic charge image) by exposing the charged electrostatic charge image carrier surface. A developing means for developing an electrostatic latent image formed on the surface of the electrostatic charge image carrier using a developer carried on the developer carrier, and forming a toner image on the surface of the electrostatic charge image carrier. The developer of the present invention is used, including a transfer unit that transfers the formed toner image to the surface of the transfer medium and a fixing unit that fixes the toner image transferred to the surface of the transfer body. The image forming apparatus according to the present embodiment may include means other than the above-described means.

  An example of the image forming apparatus according to the present embodiment is schematically shown in FIG. The image forming apparatus 8 includes a charging unit 10, an exposure unit 12, an electrophotographic photosensitive member 14 that is an electrostatic charge image carrier, a developing unit 16, a transfer unit 18, a cleaning unit 20, and a fixing unit 22. Prepare.

  In the image forming apparatus 8, around the electrophotographic photosensitive member 14, a charging unit 10 that is a charging unit that charges the surface of the electrophotographic photosensitive member 14 and the charged electrophotographic photosensitive member 14 are exposed and according to image information. Formed on the surface of the electrophotographic photoreceptor 14, an exposure unit 12 that is an exposure unit that forms an electrostatic charge image, a development unit 16 that is a development unit that develops the electrostatic charge image with toner and forms a toner image. A transfer unit 18 that is a transfer unit that transfers the toner image onto the surface of the transfer material 24 and a cleaning unit 20 that is a cleaning unit that removes toner remaining on the surface of the electrophotographic photosensitive member 14 after transfer are in this order. Has been placed. A fixing unit 22 that is a fixing unit (image fixing device) for fixing the toner image transferred to the transfer material 24 is disposed on the left side of the transfer unit 18.

  An operation of the image forming apparatus 8 according to the present embodiment will be described. First, the surface of the electrophotographic photosensitive member 14 is uniformly charged by the charging unit 10. Next, light is applied to the surface of the electrophotographic photosensitive member 14 by the exposure unit 12, and the charged charges in the irradiated portion are removed, and an electrostatic charge image is formed according to image information. Thereafter, the electrostatic image is developed by the developing unit 16, and a toner image is formed on the surface of the electrophotographic photoreceptor 14. For example, in the case of a digital electrophotographic copying machine using an organic photoconductor as the electrophotographic photoconductor 14 and using a laser beam as the exposure unit 12, the surface of the electrophotographic photoconductor 14 is negatively charged by the charging unit 10. Then, a digital latent image is formed in a dot shape by the laser beam light, and toner is applied to the portion irradiated with the laser beam light by the developing unit 16 to be visualized. In this case, a negative bias is applied to the developing unit 16. Next, in the transfer unit 18, a transfer material 24 such as paper is superimposed on the toner image, and a charge having a polarity opposite to that of the toner is applied to the transfer material 24 from the back side of the transfer material 24. Is transferred to the transfer material 24. The transferred toner image is subjected to heat and pressure by a fixing member in the fixing unit 22 and is fused and fixed to the transfer material 24. On the other hand, toner remaining on the surface of the electrophotographic photoreceptor 14 without being transferred is removed by the cleaning unit 20. One cycle is completed in a series of processes from charging to cleaning. In FIG. 3, the toner image is directly transferred to the transfer material 24 such as paper by the transfer unit 18, but it may be transferred via a transfer body such as an intermediate transfer body.

  Hereinafter, the charging unit, electrostatic charge image carrier, exposure unit, developing unit, transfer unit, cleaning unit, and fixing unit in the image forming apparatus 8 of FIG. 3 will be described.

(Charging means)
For example, a charging device such as a corotron as shown in FIG. 3 is used as the charging unit 10 as a charging unit, but a conductive or semiconductive charging roll may be used. A contact charger using a conductive or semiconductive charging roll may apply a direct current to the electrophotographic photosensitive member 14 or may superimpose an alternating current. For example, the charging unit 10 charges the surface of the electrophotographic photosensitive member 14 by generating a discharge in a minute space near the contact portion with the electrophotographic photosensitive member 14. Normally, it is charged from -300V to -1000V. The conductive or semiconductive charging roll may have a single layer structure or a multiple structure. Further, a mechanism for cleaning the surface of the charging roll may be provided.

(Static charge image carrier)
The electrostatic charge image carrier has a function of forming at least a latent image (electrostatic charge image). A preferable example of the electrostatic image bearing member is an electrophotographic photosensitive member. The electrophotographic photoreceptor 14 has a coating film containing an organic photoreceptor or the like on the outer peripheral surface of a cylindrical conductive substrate. The coating film is a substrate in which a subbing layer and a photosensitive layer including a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are formed in this order on the substrate as necessary. is there. The order of stacking the charge generation layer and the charge transport layer may be reversed. These are laminated photoconductors in which a charge generation material and a charge transport material are contained in separate layers (charge generation layer, charge transport layer), but both the charge generation material and the charge transport material are the same. A single-layer type photoreceptor included in the above layer may be used, and a laminated photoreceptor is preferable. Further, an intermediate layer may be provided between the undercoat layer and the photosensitive layer. In addition, other types of photosensitive layers such as an amorphous silicon photosensitive film may be used in addition to the organic photoreceptor.

(Exposure means)
There is no particular limitation on the exposure unit 12 that is an exposure unit, and for example, an optical system device that can expose a light source such as semiconductor laser light, LED light, or liquid crystal shutter light on the surface of the electrostatic charge image carrier in a desired image-like manner. Etc.

(Development means)
The developing unit 16 as developing means has a function of developing a latent image formed on the electrostatic charge image carrier with a developer containing toner to form a toner image. Such a developing device is not particularly limited as long as it has the above-mentioned function, and can be appropriately selected according to the purpose. For example, toner for developing an electrostatic image is used using a brush, a roller, or the like. A known developing device having a function of adhering to the electrophotographic photosensitive member 14 may be used. For the electrophotographic photosensitive member 14, a DC voltage is usually used, but an AC voltage may be superimposed and used.

  Further, the developing unit 16 will be described in detail with reference to FIG. A developing sleeve 26 that is a developer carrying member is provided in the developing unit 16. Electric charges are applied to the sleeve 26, and a developer layer 30 using a magnetic brush carried on the developing sleeve 26 is used. The electrostatic latent image is developed on the electrophotographic photosensitive member 14 which is the electrostatic latent image carrier shown in 3 to form an image. Further, the developing unit 16 is configured to scrape a part of the developer layer 30 formed by the magnetic brush, and to transport the developer layer 30 between the developing sleeve 26 and the electrophotographic photosensitive member 14 with only an appropriate amount of the developer layer 30. A magnetic brush forming member (trimmer member) 25 is formed. As can be seen from the structure of FIG. 4, the area between the developing sleeve 26 and the magnetic brush forming member 25 is narrow, so that physical stress is applied to the developing sleeve 26, the magnetic brush forming member 25, and the developer. The surfaces of the developing sleeve 26 and the magnetic brush forming member 25, which are constituent members, are likely to be worn, resulting in a decrease in developer transport capability, and deterioration in developer transport and replacement by the developing sleeve.

  The developer layer 30 has the above-described silicone oil-treated inorganic fine particles 36 or lubricant 38 added to the developer, with the toner 34 electrically attached to the carrier 32 made of the above-described magnetic powder dispersed carrier or resin-coated carrier. Alternatively, both of the silicone oil-treated inorganic fine particles 36 or the lubricant 38 are detachably attached. When the developing sleeve 26 rotates and a part of the developer layer 30 formed by the magnetic brush is scraped off by the magnetic brush forming member (trimmer member) 25, the silicone oil-treated inorganic fine particles 36 and the lubricant 38 are removed. A part of the magnetic brush forming member (trimmer member) 25 adheres to the magnetic brush forming member (trimmer member) 25, and the lubricating layer 28 is formed at the contact portion of the magnetic brush forming member (trimmer member) 25 with the developer layer 30. Similarly, the silicone oil-treated inorganic fine particles 36 and the lubricant 38 added to the developer come into contact with the surface of the developing sleeve 26 and form a lubricating layer on the surface of the developing sleeve 26 when forming the developer layer 30 with a magnetic brush. Form. As a result, even when the developing sleeve 26 is rotated at a high peripheral speed, the lubricating layer is formed on the surface of the developing sleeve 26 and the surface of the magnetic brush forming member 25. The transport and changeability of the developer is stabilized over time, and sufficient toner for obtaining a desired development density can be supplied to the surface of the photoreceptor. In addition, the magnetic brush forming member can stably form a normal magnetic brush over time, so that desired development can be stably performed, and image quality problems such as image density reduction and toner fogging can be prevented. Can be suppressed.

(Transfer means)
As the transfer unit 18 serving as transfer means, for example, a charge opposite in polarity to the toner is applied to the transfer material 24 from the back side of the transfer material 24 as shown in FIG. 3, and the toner image is transferred to the transfer material 24 by electrostatic force. A transfer roll and a transfer roll pressing device using a conductive roll or a semiconductive roll that transfers directly to the surface of the transfer material 24 via the transfer material 24 can be used. . A direct current may be applied to the transfer roll as a transfer current applied to the electrostatic image carrier, or an alternating current may be applied in a superimposed manner. The transfer roll can be arbitrarily set depending on the width of the image area to be charged, the shape of the transfer charger, the opening width, the process speed (circumferential speed), and the like. Further, a single layer foam roll or the like is suitably used as a transfer roll for cost reduction. As a transfer method, a method of transferring directly to the transfer material 24 such as paper or a method of transferring to the transfer material 24 via an intermediate transfer member may be used.

  A known intermediate transfer member can be used as the intermediate transfer member. Materials used for the intermediate transfer member include polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene phthalate, PC / polyalkylene terephthalate (PAT) blend material, ethylene tetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend materials, and the like can be mentioned. From the viewpoint of mechanical strength, an intermediate transfer belt using a thermosetting polyimide resin is preferable.

(Cleaning means)
The cleaning unit 20 as a cleaning means may be appropriately selected as long as it cleans the residual toner on the electrostatic image carrier, such as a blade cleaning method, a brush cleaning method, or a roll cleaning method. . Among these, it is preferable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber. Among them, it is particularly preferable to use a polyurethane elastic body because of its excellent wear resistance. However, there may be a mode in which the cleaning unit 20 is not used when toner having high transfer efficiency is used.

(Fixing means)
The fixing unit 22 serving as a fixing unit (image fixing device) fixes the toner image transferred to the transfer material 24 by heating, pressing, or heating and pressing, and includes a fixing member.

(Transfer material)
Examples of the transfer material (paper) 24 to which the toner image is transferred include plain paper, OHP sheets, and the like used in electrophotographic copying machines and printers. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer material is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with resin, art paper for printing, etc. Can be preferably used.

  Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereto. In the examples, “parts” represents “parts by weight” and “%” represents “% by weight” unless otherwise specified.

<Measuring method of various characteristics>
First, methods for measuring physical properties of toners and the like used in Examples and Comparative Examples will be described.

(Volume average particle diameter of higher alcohol, toner, carrier core):
The volume average particle size and the number average particle size can be measured by measuring with a multisizer type II (manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm. At this time, the measurement is performed after the particles to be measured are dispersed in an electrolyte aqueous solution (isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds. When the measurement particles are hydrophobic, a few drops of a 10% by weight aqueous sodium dodecylbenzenesulfonate solution are dropped into the electrolyte solution until the measurement particles become familiar, and then ultrasonic dispersion is performed for an additional 30 seconds to perform measurement. .

  The volume average particle diameter D50v can be obtained as follows. For the particle size range (channel) divided on the basis of the particle size distribution measured with the above-mentioned Multisizer type II (manufactured by Beckman-Coulter), the cumulative distribution is drawn by drawing the cumulative distribution from the small diameter side in terms of volume and number. % Particle size is defined as volume D16v and number D16p, particle size at cumulative 50% is defined as volume D50v and number D50p, and particle size at cumulative 84% is defined as volume D84v and number D84p. At this time, D50v represents a volume average particle diameter.

  The number average particle diameter of the carrier core material can be confirmed by converting the projected area of 50 carriers observed with a scanning electron microscope (SEM) into a spherical shape by image processing.

(Volume average particle diameter of resin fine particles, colorant particles, etc.)
Volume average particle diameters of resin fine particles, colorant particles, and the like were measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

(Measuring method of melting point of higher alcohol and fatty acid metal salt)
The melting points of higher alcohols and fatty acid metal salts were determined using a differential scanning calorimeter (Perkin Elmer: DSC-7) according to ASTM D3418-97. The temperature correction of the detection part of this apparatus (DSC-7) uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. The sample was measured using an aluminum pan and an empty pan set for control.

<Preparation of developer>
(Production of zeolite particles A)
Synthetic zeolite (HSZ-500KOA, manufactured by Tosoh Corporation) 100 parts by weight γ-aminopropyltriethoxysilane (2.0% by weight ethanol solution) 50 parts by weight The above components are mixed in a rotary evaporator and dried under reduced pressure, and silane coupling treatment Zeolite A was obtained.

(Production of zeolite particles B)
In addition, zeolite B was used as an untreated zeolite for comparison.

(Production of zeolite particles C):
Synthetic zeolite (HSZ-500KOA, manufactured by Tosoh Corporation) 100 parts by weight Alkylacetoacetate aluminum diisopropylate 2.0% by weight 2-butanone solution ("Plenact AL-M" manufactured by Ajinomoto Fine Techno Co., Ltd.) 50 parts by weight Were mixed and dried under reduced pressure using a rotary evaporator to obtain zeolite C treated with silane coupling.

(Production of silicone oil-treated silica particles A)
Silica fine particles having a particle size of 50 nm 100 parts by weight Dimethyl silicone oil (15% by weight toluene solution) 100 parts by weight The above was mixed and dried under reduced pressure using a rotary evaporator to obtain silicone oil-treated silica particles A.

(Production of silicone oil-treated silica particles B): Silica fine particles having a particle size of 50 nm 100 parts by weight Methylphenyl silicone oil ( 15% by weight toluene solution) 100 parts by weight The above was mixed in a rotary evaporator and dried under reduced pressure. Got.

(Production of higher alcohol particles A)
Higher alcohol (UNILIN manufactured by Baker Hughes) was subjected to reduced pressure treatment at 100 ° C. in a heating and vacuum oven to remove volatile components, kneaded and pulverized at 80 ° C., pulverized with a jet mill, and then subjected to particle size adjustment by air classification. As a result, higher alcohol particles A having a volume average particle size of 10 μm and a melting point of 84 ° C. were obtained.

(Production of higher alcohol particles B):
Higher alcohol (UNILIN, manufactured by Baker Hughes) was subjected to reduced pressure treatment at 150 ° C. in a heating and vacuum oven to remove volatile components, kneaded and pulverized at 85 ° C., pulverized with a jet mill, and then subjected to particle size adjustment by air classification. As a result, higher alcohol particles B having a volume average particle size of 10 μm and a melting point of 89 ° C. were obtained.

(Production of fatty acid metal salt particles A)
Zinc stearate (reagent: Wako Pure Chemical Industries, Ltd.) was kneaded and pulverized at 120 ° C., then pulverized with a jet mill, and then the particle size was adjusted by air classification. As a result, fatty acid metal salt particles A having a volume average particle size of 12 μm and a melting point of 130 ° C. were obtained.

(Production of fatty acid metal salt particles B)
Aluminum stearate and tri (reagent: Nacalai Tesque Co., Ltd.) were kneaded and pulverized at 90 ° C. and then pulverized with a jet mill, and then the particle size was adjusted by air classification. As a result, fatty acid metal salt particles B having a volume average particle size of 12 μm and a melting point of 99 ° C. were obtained.

(Manufacture of toner A)
Styrene / n-butyl acrylate copolymer (copolymerization ratio 80:20) 88 parts by weight Polypropylene wax 5 parts by weight Carbon black (Regal 330, manufactured by Cabot Corp.) 7 parts by weight Extruder (TEM48, manufactured by Toshiba Machine Co., Ltd.) ), And the kneaded product was pulverized with a jet mill and then classified with an air classifier to obtain toner base particles having a volume average particle size of 8.0 μm. 0.5 parts by weight of titanium oxide particles (manufactured by STT-30EHJ Titanium Industry Co., Ltd.) and 1.0 parts by weight of silica particles (manufactured by Nippon Aerosil Co., Ltd., R972) were added thereto, and 3 times at 3,000 rpm with a Henschel mixer Toner A was obtained by mixing for a minute.

(Manufacture of carrier mother particle A)
Ferrite particles (Powder Tech Co., Ltd., number average particle size = 46 μm) 1000 parts by weight Styrene-methyl methacrylate copolymer resin (copolymerization ratio 20:80, Tg 84 ° C.)
30 parts by weight Carbon black (Regal 330, manufactured by Cabot Corporation) 3 parts by weight Toluene 300 parts by weight The above composition was put into a vacuum heating type kneader, mixed and dried under reduced pressure while heating to 70 ° C. The obtained product was sieved with a 75 μm mesh to obtain carrier base particles A in which a resin coating layer was formed on ferrite particles as a carrier core material.

<Example 1>
Toner A 100 parts by weight Silicone oil-treated silica A 1.0 part by weight Higher alcohol particles A 0.6 part by weight or more was mixed with a Henschel mixer at 3,000 rpm for 3 minutes to obtain toner 1.

Carrier base particle A 1000 parts by weight Zeolite particle A 3 parts by weight The above components were put into a dry processing apparatus (Nobilta NOB130, manufactured by Hosokawa Micron Corporation), the jacket temperature was adjusted to 60 ° C., and the internal temperature was adjusted at 1000 rpm. Treated for 5 minutes. The treated sample was taken out and sieved with a 75 μm mesh to obtain Carrier 1.

  Next, 100 parts by weight of carrier 1 and 8 parts by weight of toner 1 were mixed in a V-type blender at 25 ° C. and room temperature at 40 rpm for 20 minutes to obtain Example Developer 1.

<Example 2>
Example Developer 2 was obtained in the same manner as in Example 1 except that the fatty alcohol metal salt particles A were changed to 0.5 parts by weight instead of 0.6 parts by weight of the higher alcohol particles A.

<Example 3>
Example Developer 3 was obtained in the same manner as in Example 1 except that the silicone oil-treated silica A was not added.

<Example 4>
Example developer 4 was obtained in the same manner as in Example 2 except that the silicone oil-treated silica A was not added.

<Example 5>
Example Developer 5 was obtained in the same manner as in Example 1 except that the higher alcohol particles A were not added.

<Example 6>
Example Developer 6 was obtained in the same manner as in Example 1 except that zeolite particle A was replaced with zeolite particle C.

<Example 7>
Example Developer 7 was obtained in the same manner as in Example 1 except that the silicone oil-treated silica A was replaced with the silicone oil-treated silica B.

<Example 8>
Example Developer 7 was obtained in the same manner as in Example 1 except that the higher alcohol particle A was replaced with the higher alcohol particle B.

<Example 9>
Example Developer 7 was obtained in the same manner as in Example 2 except that the fatty acid metal salt particles A were replaced with the fatty acid metal salt particles B.

<Comparative Example 1>
The same processing as in Example 1 was performed except that the zeolite particles A were replaced with the zeolite particles B, whereby a comparative developer 1 was obtained.

<Comparative example 2>
The same processing as in Example 2 was performed except that the carrier 1 was changed to carrier base particles A to which zeolite was not attached, whereby a comparative developer 2 was obtained.

<Comparative Example 3>
The same processing as in Example 5 was performed except that the silicone oil-treated silica A was changed to silica fine particles having a particle diameter of 50 nm, which were untreated particles, to obtain Comparative Developer 3.

<Comparative Example 4>
The same procedure as in Example 3 was performed except that the higher alcohol particles A were not added, whereby a comparative developer 4 was obtained.

(Evaluation)
Occurrence of image defects such as image flow, image defects derived from discharge products such as streak defects, print density reduction due to developing device deterioration, and toner fogging, which are the effects of the present invention under the following conditions. Evaluated.

  In the evaluation machine, in DocuCenter 719 (made by Fuji Xerox Co., Ltd.) shown in FIG. 3, the latent image forming method was changed such that the amorphous silicon was replaced with a photosensitive member and the exposed portion became a non-image portion. A modified machine in which the peripheral speed of the developing sleeve was 550 mm / s and 850 mm / s was used.

  The toner and developer of each Example and Comparative Example were used in the developing device and the toner supply device. The evaluation environment was an air temperature of 28 ° C. and a humidity of 85 RH%. The paper was A4 paper (P paper, manufactured by Fuji Xerox Co., Ltd.). The image density was adjusted using an X-Rite 938 (manufactured by Nihon Himeki Kaisha Co., Ltd.), and the development conditions were adjusted every 1000 sheets so that the density of the evaluation image was obtained. The evaluation image is a solid image having an area of 4 cm × 10 cm and an image density ID = 1.3 to 1.4 on one A4 sheet, and a halftone image having an area of 4 cm × 10 cm and an image density ID of 0.4 to 0.6. Printed.

  For the evaluation, the output images of the 9995th sheet to the 10,000th sheet of continuous printing were used for evaluating image quality problems such as density reduction, density unevenness, and toner fog. After printing the 10,000th sheet, the sheet is stopped for 12 hours (that is, under the condition that discharge products are generated at high temperature and high humidity), and after the stop, a halftone image having a density ID of 0.4 to 0.6 is displayed on the entire surface. It was used for evaluation of image defects derived from discharge products such as image flow and streak defects when images were output. The above evaluation was taken as the 10,000th sheet evaluation result. Note that ID is an abbreviation for Image Density.

  The evaluation was further continued. When the peripheral speed of the developing sleeve was 550 mm / s, the evaluation was performed up to the 50,000th sheet. When the peripheral speed of the developing sleeve was 850 mm / s, the evaluation was performed until the 30,000th sheet.

The following grade evaluation was made for the image flow on the evaluation image and the degree of streak-like image defects.
◎: No problem ○: Minor, no problem in actual use △: Obviously the image flow and vertical stripes are visible visually ×: The image flow and defects are remarkably seen and cannot be used

The image quality state such as density reduction, density unevenness, and toner fog was evaluated visually and by image density as follows.
A: No problem O: Minor density unevenness or slight fogging is observed, but there is no problem in actual use. Δ: Density unevenness or fogging is clearly seen.
×: Unevenness in density or fogging is noticeable and unusable. XX: The set image density cannot be obtained by density adjustment. (Evaluation will be canceled)

  Regarding the above two evaluations, visual sensory grading was performed by 10 evaluators, and the maximum number of evaluation grades was used as the final evaluation result.

The evaluation results of each example and comparative example are shown in Table 1.

  The electrostatic charge developing toner of the present invention is particularly useful for uses such as electrophotography and electrostatic recording.

It is a schematic sectional drawing which shows an example of the surface state of the carrier which concerns on embodiment of this invention. It is a schematic sectional drawing which shows an example of the surface state of the carrier which concerns on embodiment of this invention. 1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. It is a schematic diagram of magnetic brush formation in an example of the structure of the developing unit in the present embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Carrier, 2 Zeolite particle, 3 Carrier base particle, 4 Resin coating layer, 5 Carrier core material, 8 Image forming apparatus, 10 Charging part, 12 Exposure part, 14 Electrophotographic photoreceptor, 16 Developing part, 18 Transfer part, 20 Cleaning section, 22 fixing section, 24 material to be transferred, 25 magnetic brush forming member, 30 developer layer, 32 carrier, 34 toner, 36 silicone oil-treated inorganic fine particles, 38 lubricant.

Claims (7)

Development of an electrostatic image using a developing method in which a magnetic brush is formed by a developer on a developing sleeve having magnetic force to develop an electrostatic latent image, and the developing sleeve is operated at a peripheral speed of 350 mm / s to 1000 mm / s. A two-component developer for developing an electrostatic charge image used in a two-component developing device for
The electrostatic charge image developing two-component developer includes a toner containing a binder resin and a color material, a carrier containing a magnetic carrier core material and a resin, and a lubricant or silicone oil or both a lubricant and silicone oil.
A two-component developer for developing an electrostatic charge image, wherein zeolite particles subjected to coupling treatment are attached to the surface of the carrier. The two-component developer for developing an electrostatic charge image according to claim 1,
A two-component developer for developing an electrostatic charge image, wherein the coupling treatment is a silane coupling treatment. The two-component developer for developing an electrostatic charge image according to claim 1,
A two-component developer for developing an electrostatic image, wherein the lubricant is a higher alcohol. The two-component developer for developing an electrostatic charge image according to claim 1,
A two-component developer for developing an electrostatic image, wherein the lubricant is a fatty acid metal salt. The two-component developer for developing an electrostatic charge image according to claim 1,
The two-component developer for developing an electrostatic charge image, wherein the silicone oil is supported on inorganic fine particles and contained as inorganic fine particles treated with silicone oil. In the two-component developer for electrostatic image development according to claim 5,
A two-component developer for developing an electrostatic charge image, wherein the inorganic fine particles are silica. A latent image forming unit that forms a latent image on the latent image carrier, a developing unit that develops the latent image using a developer for developing an electrostatic charge, and the developed toner image via an intermediate transfer member or not. An image forming apparatus including: a transfer unit that transfers the toner image on the transfer member; and a fixing unit that adds and fixes the toner image on the transfer member.
7. The image forming apparatus according to claim 1, wherein the developer for developing an electrostatic charge is the two-component developer for developing an electrostatic charge image according to claim 1.

Images