JP2005049861A - One-component magnetic toner for electrostatic charge development, process cartridge, and process cartridge reproduction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-component magnetic toner for electrostatic charge development which does not cause image defects due to toner aggregation and fusion even when the apparatus is miniaturized and speeded up, and can easily recycle a toner cartridge.
A one-component magnetic toner for electrostatic charge development comprising toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, The maximum permeability (μm _A ) of the magnetic fine particles (A) contained in the toner particles and the maximum permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles are represented by the following formula (1). One-component magnetic toner for electrostatic charge development satisfying the above condition is used.
μm _B / μm _A ≦ 1.8 (1)
[Selection figure] None

Description

  The present invention relates to a one-component magnetic toner for developing electrostatic images used in electrophotography.

  In recent years, the dry development method in the electrostatic copying method is not only used in a copying machine as in the past, but also has been expanded to the field of personal use such as a printer, a facsimile machine, and a multifunction machine with a copying machine. Therefore, there is a strong demand for downsizing and weight reduction of the device itself. In addition, due to the rapid market expansion of personal use image input devices typified by digital video and digital cameras, higher image quality is demanded as image output devices.

  Further, from the viewpoint of environmental consideration, in order to save power and realize a recycling-type consumption society, the demand for designing the apparatus and toner cartridge to be easy to recycle has become more severe. In order to meet these demands, various improvements or new developments in image forming methods have been studied and attempted.

  As dry development methods in various electrostatic copying systems currently in practical use, a two-component development system using a carrier such as toner and iron powder and a one-component development system not using such a carrier are known. . The two-component development method is the most widely used method. However, the developer deteriorates due to the toner particles adhering to the carrier surface, and the concentration ratio of the toner in the developer is reduced because only the toner is consumed. Therefore, it is difficult to keep the mixing ratio of the carrier and the toner constant, so that there is a disadvantage that the developing device is enlarged.

  The one-component development method does not use a carrier and does not have the above-described drawbacks, and is advantageous in downsizing the apparatus. The one-component development method is classified into a non-magnetic one-component development method using a non-magnetic toner and a magnetic one-component development method using a magnetic toner. The non-magnetic one-component development system is suitable for colorization because no magnetic material is used for the toner. However, in the non-magnetic one-component development method, the developer is supported on the developer support by electrostatic force due to mutual frictional charging between the developer support and the developer. There is a problem that fogging of the image portion is likely to occur and a problem of in-machine contamination due to toner scattering is likely to occur. On the other hand, the magnetic one-component development method uses a developer carrying member provided with a magnetic field generating means such as a magnet for development while holding the magnetic toner. When compared with the system, there is a problem that a development ghost is likely to occur as a common problem of the one-component development system.

  Various attempts have been made to remedy these problems. For example, a method of forming a film made of a material mainly composed of Mo, O, and H on the surface of the developer carrying member or a specific resin layer containing conductive fine particles has been proposed (for example, Patent Documents 1 and 2). Certainly, by using such a developer carrying member, it is possible to suppress the charge-up of the toner, and as a result, it is possible to prevent the development ghost from occurring. However, when the developer carrying member having such a configuration is used, the ability of the sleeve itself to impart charge to the developer is low. Therefore, particularly when the image is formed after being left in a high temperature and high humidity environment. As a result, the chargeability of the toner is lowered, resulting in a problem of low image density and uneven image density.

In order to simultaneously solve the problem of development ghost and the problem of low image density and uneven image density as described above, there is a method using a magnetic material as an external additive for toner. These methods solve the above-mentioned problems by using a magnetic material having a specific particle size distribution, a magnetic material having a specific shape, and a magnetic material subjected to a specific treatment as an external additive for toner. (For example, see Patent Documents 3 to 5).

  By using such various magnetic materials as external additives for toner, the problems of development ghost, low image density and image density unevenness are improved. However, in recent years, the following various problems have been pointed out due to the needs for downsizing, high speed, power saving, high image quality, and easy recycling design of the apparatus.

  In a magnetic toner containing a magnetic substance in toner particles, when a magnetic substance is further used as an external additive, the externally added magnetic substance is considered to adhere to the surface of the magnetic toner mainly by Coulomb force. Normally, the magnetic external additive is stably present on the surface of the toner particles by the Coulomb force. However, when the magnetic toner is held in the vicinity of or on the developer carrying member provided with a magnetic field generating means such as a magnet in the developing process, the toner particles containing the magnetic substance and the external additive In some cases, a difference in the force applied by the magnetic field from the developer carrying member may occur. If this difference is large, the magnetic external additive cannot stably exist on the toner particle surface as a result, and the magnetic external additive is peeled (released) from the toner particle surface, causing various problems.

  This phenomenon of liberation of the magnetic external additive is a major obstacle to the toner design for reducing the diameter and speed of the developer carrier for achieving downsizing of the apparatus, designing for easy recycling, and power saving. That is, as the release (peeling) of the magnetic external additive proceeds, the contact probability of other toner particles or various members including the developer carrying member with respect to the resin component and the wax component on the toner surface increases. Cause aggregation of toner particles and fusion of toner particles to various members, and causes image defects such as image white streaks. These phenomena become more prominent as the diameter of the developer carrier is reduced and the speed is increased. Further, due to the recent demand for higher image quality, attempts have been made to further reduce the particle size of the toner and to add a high-performance external additive. As the content of small-sized particles increases, the above problem becomes more prominent. In addition, the toner material design such as low-temperature fixing for power saving is hindered.

Further, the small particle size particles such as the released magnetic external additive are then applied to the narrow uneven portions on the surface of the developer carrying member provided with a magnetic field generating means such as a magnet. It is fixed by frictional force with the regulating member. For this reason, a charging failure of the toner at the time of development may be caused. In addition, more steps are required to disassemble and recycle the toner cartridge after use. For this reason, it also hinders from the viewpoint of easy recycling design.
JP-A-1-276174 JP-A-7-281517 Japanese Patent Laid-Open No. 11-84714 Japanese Patent Laid-Open No. 11-143121 Japanese Patent Laid-Open No. 11-174729

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a one-component magnetic toner for electrostatic charge development that does not cause image defects due to toner aggregation or fusion even when the apparatus is downsized and speeded up. And

Another object of the present invention is to provide a one-component magnetic toner for electrostatic charge development that does not cause image fogging due to toner and can maintain high image quality even when the apparatus is downsized and speeded up. Another object of the present invention is to provide a one-component magnetic toner for electrostatic charge development that is easy to disassemble and recycle members after use of the toner cartridge.

As a result of earnest research on the magnetic properties of the developer, the present inventor has found that the maximum magnetic permeability (μm _A ) of the magnetic fine particles contained in the toner particles and the toner in the one-component magnetic toner to which magnetic fine particles are externally added. It has been found that the above-mentioned problems can be achieved by using a one-component magnetic toner that satisfies a certain relationship with the maximum magnetic permeability (μm _B ) of the magnetic fine particles externally added to the particles. Furthermore, the present inventors have found that the above-mentioned one-component magnetic toner contains a certain amount of small-diameter particles, whereby a better effect can be obtained, and the present invention has been completed.

That is, the one-component magnetic toner for electrostatic charge development of the present invention has toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles. The maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) contained in the toner particles and the maximum magnetic permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles are expressed by the following formula (1). It is characterized by satisfying the relationship.
μm _B / μm _A ≦ 1.8 (1)
Further, the present invention is a process cartridge that integrally includes at least one selected from an image carrier, a cleaning member, and a charging member, and a developing device, and is detachably attached to an electrophotographic apparatus,
The developing device is provided in contact with the housing portion for housing the developer, the developer carrying body having the nonmagnetic sleeve having the fixed magnet therein, and carrying the developer on the nonmagnetic sleeve, and the developer carrying body. A regulating member that regulates the amount of the developer on the developer carrying member,
The developer includes toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, and the magnetic fine particles contained in the toner particles. maximum permeability ([mu] m _a) and maximum magnetic permeability ([mu] m _B) and the electrostatic latent image developing one-component magnetic satisfies the relation of the formula (1) of externally added to the magnetic particles in the toner particles (B) of (a) A process cartridge is provided that is toner.
Furthermore, the present invention is a method of remanufacturing a process cartridge that has at least one selected from an image carrier, a cleaning member, and a charging member, and a developing device, and is detachably attached to an electrophotographic apparatus. And
The developing device is provided in contact with the housing portion for housing the developer, the developer carrying body having the nonmagnetic sleeve having the fixed magnet therein, and carrying the developer on the nonmagnetic sleeve, and the developer carrying body. A regulating member that regulates the amount of developer on the developer carrying member;
The process cartridge is taken out of the electrophotographic apparatus when the electrostatic charge developing one-component magnetic toner is used up or the process cartridge cannot perform the desired performance, and the use history information of the process cartridge is accumulated. Or have means to display;
According to the usage history information, the reproduction method cleans or replaces a member constituting the process cartridge or the developing device, or replenishes the developing device with one-component magnetic toner for developing an electrostatic charge, so that the electrophotographic apparatus can be used again. A process of remanufacturing so that it can be installed and used;
Storing or displaying updated use history information of a process cartridge in the means for storing or displaying the use history when the reproduction is performed;
The developer includes toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, and the magnetic fine particles contained in the toner particles. wherein the maximum magnetic permeability ([mu] m _a) and the maximum magnetic permeability of the magnetic fine particles externally added to the toner particles and ([mu] m _B) is a component magnetic toner for electrostatic charge development satisfies the relation of the formula (1) A process cartridge remanufacturing method is provided.

The magnetic one-component developer of the present invention has the maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) contained in the toner particles and the maximum magnetic permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles. When the image forming apparatus is downsized and speeded up, the magnetic fine particles (B) as the external additive have high adhesion stability to the toner particle surface and are not easily released. However, it can have high image quality and high image durability.

  Further, the magnetic one-component developer of the present invention is less likely to release the magnetic fine particles (B) as an external additive from the surface of the toner particles, so that the amount of adhesion to the developing carrier is small, and the member can be regenerated after using the process cartridge. Can be easily.

The one-component magnetic toner for electrostatic charge development of the present invention (hereinafter, also simply referred to as “one-component magnetic toner”) includes toner particles containing at least magnetic fine particles (A) and a binder resin, and the magnetic toner particles include The magnetic fine particles (B) externally added, and the maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) contained in the toner particles and the maximum permeability of the magnetic fine particles (B) externally added to the toner particles. Magnetic permeability (μm _B ) satisfies the relationship of the following formula (1).
μm _B / μm _A ≦ 1.8 (1)

In the present invention, the magnetic fine particles (A) contained in the toner particles (added internally) and the magnetic fine particles (B) added externally to the toner particles (that is, used by being mixed with the toner particles) include: Known magnetic materials, for example, metals such as iron, cobalt, nickel and alloys thereof; metal oxides such as FeSO ₄ , γ-Fe ₂ O ₃ , cobalt-added iron oxide; Mn—Zn ferrite, Ni—Zn ferrite Various ferrites such as: powders mainly composed of magnetite, hematite, etc. can be used, and those whose surfaces are treated with a surface treatment agent such as a silane coupling agent or titanate coupling agent, or those coated with a polymer are preferred. Used.

The maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) internally added in the toner particles is preferably 2.0 to 20.0 μH / m from the viewpoint of toner transportability and developability. More preferably, it is 5 to 6.0 μH / m. Moreover, it is preferable that the magnetic strength of the magnetic fine particles (A) at 79.6 kA / m is 25 to 100 Am ² / kg.

  The number average particle diameter of the magnetic fine particles (A) internally added in the toner particles is preferably about 0.05 to 1 μm from the viewpoint of dispersibility in the binder resin. The mixing ratio of the magnetic fine particles (A) is preferably 40 to 200 parts by mass, more preferably 45 to 150 parts by mass with respect to 100 parts by mass of the binder resin. It is particularly preferable to use in the range of ˜120 parts by mass.

The maximum magnetic permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles is preferably 2.0 to 6.5 μH / m in view of the ease of recycling after using the toner cartridge. Is preferably 2.5 to 6.0 μH / m, and more preferably 2.5 to 5.4 μH / m. Moreover, it is preferable that the strength of magnetization of the magnetic fine particles (B) at 79.6 kA / m is 20 to 80 Am ² / kg.

  The number average particle diameter of the magnetic fine particles (B) externally added to the toner particles is preferably about 0.05 to 3 μm, and the mixing ratio is 0.1 to 3 based on the mass of the toner particles. It is preferable that it is the range of 2.0 mass%.

The number average particle size of the magnetic fine particles (A) internally added in the toner particles and the magnetic fine particles (B) externally added to the toner particles can be determined by measuring a photograph taken with a transmission electron microscope or the like with a digitizer or the like. Can be sought.

The relationship between the magnetic flux density, the magnetic field, and the magnetic permeability μ is expressed by the following equation.
B = μ · H
In the above formula, B represents the magnetic flux density, and H represents the magnetic field. It can be seen that a material having a higher magnetic permeability exhibits a higher magnetization with respect to a constant magnetic field, and when the magnetic field is generated by a magnet, the material is strongly attracted to the magnet.

The value of the maximum magnetic permeability in the present invention can be measured using various measuring methods.
For example, as a method for directly measuring a magnetic material in powder form, a vibrating sample magnetometer (manufactured by Toei Kogyo Co., Ltd .: VSM-3) is used, a predetermined amount of magnetic powder to be measured is set in a holder, and maximum application is performed. It can be obtained from a BH curve obtained with a magnetic field of 796 (kA / m). Also, a measurement method can be used in which a toroidal magnetic core is uniformly wound, an appropriate alternating magnetic field is applied, and an inductance change at that time is obtained.

  Furthermore, as the magnetic fine particles (A) and (B) used in the present invention, those subjected to the hydrophobic treatment as described above are also preferably used. By applying the hydrophobizing treatment, the humidity characteristics of the toner itself are increased, and changes in development characteristics due to environmental fluctuations are reduced.

  As a method for hydrophobizing the magnetic fine particles, for example, the hydrophobizing treatment is performed with a titanium coupling agent, a silane coupling agent, or the like at a ratio of 0.01 to 5 parts by mass with respect to 100 parts by mass. Specific treatment agents include titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate and bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2 -Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β-vinylbenzylaminoethyl-N-γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxy Examples include silane coupling agents such as silane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. Hydrophobic treatment is generally performed by stirring the dried magnetic powder in various mills and adding the coupling agent solubilized in a solvent in which a coupling agent such as toluene or benzene is soluble and then dropping at a sufficiently dispersed rate. After mixing and reacting, the solvent and reaction by-products are evaporated and removed.

The magnetic fine particles (B) adhering to the toner particles (that is, externally added to the toner particles) in the magnetic field such as on the developer carrier are stably present on the toner particle surface. The ratio (μm _B / μm _A ) of the maximum magnetic permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles to the maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) internally added to the toner It must be 1.8 or less. This ratio (μm _B / μm _A ) is preferably 1.4 or less, particularly preferably 0.9 or less.

In order to set the ratio (μm _B / μm _A ) within the above range, the type and amount of the magnetic fine particles (A) contained in the toner particles and the externally added magnetic fine particles (B) are appropriately selected during toner production. A method is mentioned. Further, the maximum magnetic permeability (μm _A ) of the magnetic fine particles (A) internally added to the toner particles and the maximum magnetic constant (μm _B ) of the magnetic fine particles (B) externally added to the toner particles are set to predetermined values. For this purpose, a method of selecting a magnetic material or performing a known treatment such as a heat treatment or a treatment in a rotating magnetic field on the magnetic material can be used.

  The binder resin contained in the toner particles constituting the one-component magnetic toner of the present invention is, for example, a styrene-substituted homopolymer such as polystyrene, poly-p-chlorostyrene, or polyvinyltoluene, or a styrene copolymer. Styrene resin, polyvinyl chloride, phenol resin, naturally modified phenolic resin, naturally modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene Examples thereof include resins, polyvinyl butyral, terpene resins, coumarone indene resins, and petroleum resins. Of these, crosslinked styrene resins and polyester resins are preferable binder resins.

  Examples of the styrene copolymer include styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer. Polymer, styrene-α-chloromethacrylic acid methyl copolymer, styrene-acrylonitrile copolymer, styrene vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Examples thereof include a polymer, a styrene-isoprene copolymer and a styrene-acrylonitrile-indene copolymer.

As comonomer for styrene monomer of styrene copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methacrylic acid Monocarboxylic acids having a double bond such as methyl, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile and acrylamide or substituted products thereof; maleic acid, butyl maleate, methyl maleate and maleic acid Dicarboxylic acids having a double bond such as dimethyl or its substitutes; vinyl chloride; vinyl esters such as vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; And vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; and vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more with the styrene monomer.

  Examples of the crosslinking agent that can be used in obtaining the styrene copolymer include compounds having two or more polymerizable double bonds. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; And divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These crosslinking agents are used alone or in admixture of two or more.

  The polyester resin is obtained by condensation polymerization of alcohol and carboxylic acid. Examples of the alcohol used include polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,4-butane. Diols such as diol, neopentyl glycol, 1,4-butenediol; 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, and polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A And the like. Etherified bisphenols such as: divalent alcohols having these substituted with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms; other divalent alcohols alone.

  Examples of the carboxylic acid used to obtain the polyester resin include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, Adipic acid, sebacic acid, malonic acid, divalent organic acid monomers in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, acid anhydrides thereof, lower alkyl esters and linolenic acid A double body and other divalent organic acid monomers can be mentioned.

  In order to obtain a polyester resin used as a binder resin, not only a polymer composed of only the above bifunctional monomer but also a polymer containing a component composed of a trifunctional or higher polyfunctional monomer may be used. Is preferred. Examples of the trihydric or higher polyhydric alcohol monomer that is such a polyfunctional monomer include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaesitol, Dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4- Examples include butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, and others.

  Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Examples thereof include carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empor trimer acid, acid anhydrides thereof, and the like.

  In the one-component magnetic toner of the present invention, it is preferable to use a charge control agent in the toner particles (internal addition) or mixed with the toner particles (external addition). With the charge control agent, the charge amount of the toner can be optimally controlled according to the development system. The following materials are used to control the one-component magnetic toner to be negatively charged.

  For example, organometallic complexes and chelate compounds are effective, and there are monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acid metal complexes, and aromatic dicarboxylic acid metal complexes. Others include aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids and aromatic polycarboxylic acids, or metal salts or esters of carboxylic acids selected from these carboxylic acid groups, anhydrides of aromatic polycarboxylic acids, bisphenols And phenol derivatives.

  The following materials are used to control the one-component magnetic toner of the present invention to be positively charged. Modified products with nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate; and oniums such as phosphonium salts thereof. Salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, Russian salts, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin Such as diorgano tin borate of the rate, and the like. These can be used alone or in combination of two or more.

The above-described charge control agent is preferably used in the form of fine particles. In this case, the number average particle diameter of these charge control agents is preferably 2 μm or less, and more preferably 1 μm or less. When these charge control agents are internally added to the toner particles, the amount is preferably 0.1 to 20 parts by weight, particularly preferably 0.2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  In the one-component magnetic toner of the present invention, it is preferable to use a wax in the toner particles (internal addition). Petroleum waxes and derivatives thereof such as paraffin wax, microcrystalline wax, petrolatum; montan wax and derivatives thereof; Fischer-Tropsch wax and derivatives thereof; polyolefin waxes and derivatives thereof typified by polyethylene; natural products such as carnauba wax and candelilla wax Wax and derivatives thereof, which include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, and animal waxes are exemplified. In the case of using a new wax, an improvement in offset resistance of the toner is achieved.

  When the wax is used, the one-component magnetic toner of the present invention preferably has a content in the range of 0.5 to 50 parts by mass with respect to 100 parts by mass of the binder resin.

  In addition, other additives may be mixed in the one-component magnetic toner of the present invention as necessary. Examples of additives include lubricants such as fluororesin and zinc stearate; abrasives such as cerium oxide and silicon carbide; anti-caking agents; conductivity imparting agents such as carbon black and tin oxide; or fixing such as low molecular weight polyolefins. There are auxiliaries. In addition, as the inorganic fine particles used as a fluidity imparting agent in the one-component magnetic toner of the present invention, any known inorganic fine particles such as silicon oxide, aluminum oxide, titanium oxide, barium titanate and their hydrophobized products can be used alone. Or 2 or more types can be mixed and used. Examples of the inorganic fine particle surface treatment agent used in the present invention include various silicone oils such as methyl hydrogen polysiloxane, dimethyl polysiloxane, and methylphenyl polysiloxane; methyltrimethoxysilane, ethyltrimethoxysilane, and hexyltrimethoxy. Various alkylsilanes such as silane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, n-octadecyldimethyl (3- (trimethoxysilyl) propyl) ammonium chloride; Various fluoroalkylsilanes such as fluoromethylethyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane; in particular vinyltrimethoxysilane and γ-aminopro Any treatment agent of silane-based, titanium-based, aluminum-based, and alumina-zirconia-based metal coupling agents represented by silane coupling agents such as rutrimethoxysilane can be used. It is preferable to mix and use.

  As a method for producing the toner particles in the present invention, after sufficiently mixing the toner constituent materials as described above with a ball mill or other mixer, the mixture is thoroughly kneaded using a heat kneader such as a hot roll kneader or an extruder, and cooled. A method of obtaining toner particles by mechanically pulverizing after solidification and classifying the pulverized powder is preferable. In addition, a toner manufacturing method by a polymerization method in which a predetermined material is mixed with a monomer to constitute a binder resin to obtain an emulsion suspension, and then polymerized to obtain toner particles; resin fine particles and a predetermined material In a so-called microcapsule toner composed of a core material and a shell material, a method in which a predetermined material is contained in the core material or the shell material, or both of them; There is a method in which toner particles are obtained by dispersing constituent materials in a solution and then spray drying. Furthermore, the magnetic fine component (B) in the present invention and, if necessary, the desired additive and toner particles are sufficiently mixed by a mixer such as a Henschel mixer to produce the magnetic one-component toner of the present invention.

The toner particles in the present invention preferably have a weight average particle diameter of 3.0 to 12.0 μm, and more preferably 5.0 to 9.0 μm.
In addition, the toner of the present invention achieves a reduction in size and weight of the apparatus, a high image quality, and easy recycling of the toner cartridge, and the toner having a particle size of 0.6 μm or more and 4 μm or less contained in the toner. Is preferably 10 to 50% by number, more preferably 10 to 40%, particularly preferably 10 to 10% in the measurement for particles having a particle size of 0.6 μm or more and 4 μm or less. 30%.

  The cumulative proportion of toner having a particle size of 0.6 μm or more and 4 μm or less contained in the toner is measured using a flow type particle size analyzer (FPIA-1000 type) manufactured by Toa Medical Electronics.

  The flow type particle size analyzer will be described below. First, an outline of a measuring apparatus used in the present invention is shown in FIG. Moreover, FIG. 2 is a figure for demonstrating the principal part of this measuring apparatus. As shown in FIG. 1, this apparatus introduces a sheath liquid supply source 27 used for measurement, a sheath liquid chamber 26 for temporarily storing the sheath liquid and delivering a predetermined amount, and the sheath liquid chamber 26. A sample is introduced from a supply source (not shown) together with the sheath liquid thus formed to form a sample flow, a flat sea throw cell 21, a waste liquid chamber 25 provided below the flat sea throw cell 21, and the flat sea throw cell 21. A strobe 22 and an objective lens 23 that are arranged on both sides of the central portion and emit light at regular intervals, and a CCD camera 24 provided behind the objective lens 23 are provided.

  In measurement, a sample suspension in which toner particles are dispersed and suspended in an aqueous surfactant solution is used, and a predetermined amount is absorbed from a suction pipette (not shown). The absorbed sample suspension is guided to a flat sea throw cell 21 through a sample filter (not shown). As shown in FIG. 2, in the flat sea throw cell 21, sheath liquid is introduced from the chamber, and a flat sample flow is formed by the sheath liquid. The sample suspension passes through the central portion of the flat sea throw cell 21 in a form sandwiched between sheath liquids.

  As shown in FIG. 1, the sample suspension passing through the flat sea throw cell 21 is irradiated with light from the strobe 22 at regular intervals. At this time, the toner particles in the sample suspension are transferred to the objective lens 23. And is taken as a still image by the CCD camera 24. The particle image captured by the CCD camera 24 is subjected to image analysis. Thereby, the equivalent circle diameter and the circularity are calculated from the projected area and the perimeter of the particle image, and the particle size distribution, the circularity distribution, and the like can be obtained.

  Further, the one-component magnetic toner for electrostatic charge development of the present invention has at least one selected from an image carrier, a cleaning member, and a charging member, and a developing device, and is detachably attached to an electrophotographic apparatus. It can be used by being incorporated in a process cartridge. In particular, a storage portion for storing a developer; a developer carrier having a nonmagnetic sleeve having a fixed magnet therein and carrying the developer on the nonmagnetic sleeve; and provided in contact with the developer carrier And is suitably used for a process cartridge having a developing device having a regulating member that regulates the amount of developer on the developer carrying member.

  By using the magnetic toner for one-component electrostatic charge development of the present invention in the process cartridge having such a configuration, the magnetic substance as the external additive is hardly separated from the surface of the toner particles, so that the amount of adhesion to the developer carrier is small. In addition to the effect of suppressing the occurrence of image white streaks and fogging, it is possible to easily regenerate the member after using the process cartridge, and to realize the effect of increasing the number of times of reproduction. This is a preferred form.

As the image carrier used in the process cartridge of the present invention, an amorphous silicon photosensitive layer or a photosensitive member having an organic photosensitive layer is preferably used, and a photosensitive member having an organic photosensitive layer is particularly preferable. The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation material and a material having charge transport performance in the same layer, or a functional separation type photosensitive layer including a charge transport layer and a charge generation layer. There may be. A laminated photosensitive layer having a structure in which a charge generation layer and a charge transport layer are laminated in this order on a conductive substrate is one preferred example.

  As the cleaning member, a blade, a fur brush, or the like can be used. In particular, it is preferable to use a material obtained by molding urethane or silicone rubber into a blade shape as a material.

  As the charging member, there are a non-contact type using a corona charger and a contact type using a conductive roller, a conductive brush, a conductive sheet and the like, and any of them can be used. The contact type does not require a high voltage, and is a preferable configuration for efficient uniform charging, simplification, low ozone generation, and the like, and particularly a contact type using a charging roller is preferably used.

  As a preferable process condition when a charging roller is used as the charging member, the contact pressure of the charging roller with respect to the image carrier is 4.9 to 490 N / m (5 to 500 g / cm), and an AC voltage is applied to the DC voltage. In the case of using a superimposed one, it is preferable that AC voltage = 0.5 to 5 kVpp, AC frequency = 50 Hz to 5 kHz, DC voltage = ± 0.2 to ± 1.5 kV. DC voltage is preferably ± 0.2 to ± 5 kV.

  The developing device is provided in contact with the developer carrying body, a developer carrying body comprising a nonmagnetic sleeve having a fixed magnet inside, a housing portion for containing the developer, and carried on the nonmagnetic sleeve. And a regulating member that regulates the amount of the developer.

  The amount of the developer carried on the developing sleeve is regulated by a regulating member provided in contact with the developing sleeve during rotation. Thus, the developer is carried on the developing sleeve as a layer having a certain thickness. The contact pressure of the regulating member that regulates the layer thickness of the developer with respect to the developer carrying member (developing sleeve) is 5 to 50 g / cm of linear pressure, so that the regulation of the developer is stabilized and the magnetic toner layer This is preferable in that the thickness can be made suitable. When the contact pressure of the regulating member that regulates the layer thickness of the developer is less than a linear pressure of 5 g / cm, the force that regulates the developer becomes weak, and the developer leaks from fogging or the developing sleeve. It may become. When the linear pressure exceeds 50 g / cm, damage to the developer from the regulating member increases, and the developer to the regulating member regulating the deterioration of the developer and the layer thickness of the developer carrying member and the developer. It is easy to cause the fusion of.

  As the material of the regulating member that regulates the layer thickness of the developer, an elastic plate made of a material having rubber elasticity such as urethane rubber or silicone rubber or a material having metal elasticity such as phosphor bronze or stainless steel is used. Among these, urethane rubber and silicone rubber are particularly preferably used that uniformly regulate the developer layer thickness, weaken the load on the developer, and have an advantageous effect on the developer carrying member scraping.

  As the non-magnetic sleeve for carrying the developer used for the developer carrying member, the outer surface of a metallic cylinder such as aluminum or stainless steel is roughened by sandblasting, or the outer surface of the cylinder is carbon black, Those having a surface layer formed of a resin in which conductive particles such as graphite are dispersed are preferably used. As the resin for forming the surface layer, phenol resin, styrene resin, polyamide resin or the like is used. Particularly preferred is a phenolic resin.

In the process cartridge, each component member such as an image carrier, a charging member, a developing device, and a cleaning member can be provided with means for accumulating or displaying usage history information of these members or the process cartridge itself. In addition, the process cartridge itself may be provided with means for accumulating or displaying process history information for each member provided in the process cartridge or the process cartridge. In these cases, when the process cartridge is remanufactured, in accordance with the accumulated or displayed usage history information, preset member replacement or cleaning is performed. Thereby, the inspection of each member at the time of reproduction can be reduced or omitted.

  Examples of the usage history information accumulation or display method include the following. Affix a sticker displaying the number of times according to the number of times of use; attach a color marker corresponding to the number of times of use; write the number of times of use directly by engraving etc .; install a memory in the process cartridge; The process cartridge can be identified, and the history information of each member is stored in correspondence with the identification information.

  When the one-component toner for electrostatic charge development is used up or the process cartridge cannot exhibit the desired performance, the process cartridge is taken out from the electrophotographic apparatus. The removed process cartridge is subjected to reproduction such as cleaning or exchanging members constituting the process cartridge or supplying the developing device with one-component magnetic toner for electrostatic charge development in accordance with the use history information. When this reproduction is performed, the usage history information is updated by a predetermined method, and the updated usage history information is used at the next reproduction of the process cartridge.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, all the parts in an Example show a mass part.

<Example 1>
As binder resin, 100 parts of styrene-butyl acrylate copolymer (molar ratio of styrene to butyl acrylate = 80/20, Mn = 7200, Mw = 280000), magnetic iron oxide (Fe ₂ O ₃ , average particle size: 0) 90 parts of .25 μm, maximum permeability 2.0 μH / m), 3 parts of monoazo iron complex (T-77, manufactured by Hodogaya Chemical Co., Ltd.) as negative charge control agent, Fischer-Tropsch wax (melting point = 107 C., Mn = 550, Mw = 910) and 2 parts of alcohol wax (Unilin 700 (manufactured by Toyo Petrolite Co., Ltd.)) were previously mixed uniformly and heated to 130.degree. C. Was melt kneaded. The obtained kneaded product is cooled, coarsely pulverized with a hammer mill, the coarsely pulverized product is finely pulverized with a jet mill, and the obtained finely pulverized product is classified with an air classifier to obtain black toner particles (weight average particle size). Diameter 6.8 μm). Silica fine powder having a hydrophobic property and 0.5 parts of magnetic iron oxide (average particle diameter: 0.30 μm, maximum permeability 3.6 μH / m) treated with silicone oil with respect to 100 parts of the obtained black toner particles 1.2 parts of hydrophobized with hexamethyldisilazane (BET specific surface area = 200 m ² / g) were added and stirred and mixed at 1500 rpm for 2 minutes with a Henschel mixer, and then sieved with 150 mesh (aperture 100 μm) Coarse particles were removed at 1 to obtain a one-component magnetic toner 1. The cumulative proportion of toner 1 having a particle size of 0.6 μm or more and 4 μm or less was 19% by number.

<Examples 2 to 25>
In Example 1, the same method as in Example 1 was used, except that the magnetic fine particles (A) internally added to the toner particles and the magnetic fine particles (B) added externally were replaced with the magnetic iron oxide shown in Table 1. 1-component magnetic toners 2 to 25 were obtained. In addition, the magnetization intensity at 79.6 kA / m of the magnetic fine particles (A) used in Example 13 is 69 Am ² / kg, and the magnetization intensity at 79.6 kA / m of the magnetic fine particles (B) is 35 Am ² / kg.

<Comparative Examples 1 and 2>
In Example 1, the same method as in Example 1 was used, except that the magnetic fine particles (A) internally added to the toner particles and the magnetic fine particles (B) added externally were replaced with the magnetic iron oxide shown in Table 1. One-component magnetic toners 26 and 27 were obtained.

Table 1 shows the maximum magnetic permeability of the internally added magnetic fine particles (A) and the externally added magnetic fine particles (B) used for each toner, and the ratio of the maximum magnetic permeability (μm _B / μm _A ) of both.

<Evaluation>
Using the image forming apparatus shown in FIG. 3 to which the process cartridge 16 shown in FIG. Evaluation was performed according to the following image evaluation method. The evaluation results are shown in Tables 2-5.

The process cartridge and the image forming apparatus used in this embodiment are a photosensitive member 1 that is an image carrier.
Are arranged with a primary charging device 2, an exposure optical system 3, a developing device 4, a transfer device 9 and a cleaning member 11 in that order. Here, the primary charging device uses a contact charging roller in contact with the surface of the photoreceptor, and a charging voltage of DC voltage: −625 V, AC voltage: peak-to-peak voltage of 1.8 kV, and frequency of 370 Hz is applied to the charging roller. The photosensitive member is primarily charged.

  The exposure optical system 3 forms an electrostatic latent image by irradiating the primary charged photoconductor 1 with laser light whose ON / OFF is controlled according to the image to be formed.

  The developing device 4 is a roller-shaped developer carrier 5 provided so as to face the surface of the photoreceptor 1 and have a rotation axis parallel to the rotation axis of the photoreceptor 1, and an opening in the vicinity of the developer carrier 5. A toner container 15 (contains as a container) for containing the one-component magnetic toner 13, and the toner container 15 for agitating and conveying the one-component magnetic toner in the toner container 15 to the developer carrier 5. A toner agitation means 7 (not shown in FIG. 4) provided in the toner layer for regulating the amount of toner conveyed by the toner agitation means 7 and carried on the surface of the developer carrier 5 to have a uniform thickness. A thickness regulating member 6 and a developing bias power source 8 for applying a developing bias to the developer carrier 5 are provided. The outer diameter of the developer carrier 5 is 10 mm, and the angular velocity during development is 21.0 rad / sec. The electrostatic latent image formed on the photoreceptor 1 by the exposure optical system 3 is developed with the one-component magnetic toner by the developing device 4 and visualized as a toner image.

  The toner image on the photoreceptor 1 is transferred to a contact portion (nip) between the photoreceptor 1 and the transfer device 9 by a transfer device 9 to which a transfer bias is applied from the transfer current generator 10. The image is transferred onto the material P and fixed by the fixing device 12 to form a fixed image. On the other hand, toner (transfer residual toner) remaining on the surface of the photoreceptor 1 after the toner image is transferred to the transfer material P is removed by the cleaning member 11, and the removed transfer residual toner is accumulated in the waste toner container 14. The

  Further, in this image forming apparatus, as shown in FIG. 4, a process cartridge 16 that integrally holds the photosensitive member 1, the primary charging device 2, the developing device 4, the cleaning member 11, and the waste toner container 14 is included in the main body of the image forming apparatus. It is detachably mounted.

Below, the evaluation performed using each said magnetic toner is demonstrated.
(1) Evaluation of durability:
i) Image white stripes 5000 images of an image area ratio of about 3% were printed out in a high temperature and high humidity environment (33.0 ° C., 95% RH (relative humidity)). A halftone image (1 dot / 2 spaces in the sub-scanning direction) is printed out during the initial printout (10th sheet) and every 1000 sheets, and the white streak level for each durable sheet is shown below. Evaluation was performed according to the evaluation criteria. The evaluation results are shown in Table 2.

[Evaluation criteria for image white streaks]
A: No white streak occurs.
C: White streaks appear but cannot be clearly grasped with the naked eye.
E: Many white stripes can be clearly identified with the naked eye.
B is an intermediate level between A and C, and D is an intermediate level between C and E.

ii) Image fog Using the image white stripe evaluation image, the fog was evaluated based on the following evaluation criteria. The evaluation results are shown in Table 3.
[Evaluation criteria for fogging]
A: No fog occurs at all.
C: Fog is easily recognized.
E: Fog is recognized on the entire surface.
B is an intermediate level between A and C, and D is an intermediate level between C and E.

(2) Evaluation of recyclability:
After the end of the durability evaluation in (1) above, the process cartridge is disassembled, the developer carrying member with the toner attached is taken out, and air is blown for 30 seconds with an air gun (air gun) to adhere onto the developer carrying member. The toner was removed. After confirming that no toner adheres to the developer carrying member by visual observation, the developer carrying member and another new process cartridge constituting member were used, and the process cartridge was assembled again. This process cartridge was mounted again on the image forming apparatus described above, and image white streaks and image fogging were evaluated in the same manner as the durability evaluation. The evaluation results are shown in Tables 4 and 5.

The figure which shows the structure of the particle size meter used for the cumulative measurement of the toner number of the particle size 0.6 to 4 micrometer contained in a toner. The figure explaining the main part of the granulometer of FIG. The figure which shows schematic structure of one Example of the image forming apparatus which can use suitably the one-component magnetic toner of this invention. The figure which shows the structure of one Example of the process cartridge which can use suitably the one-component magnetic toner of this invention.

Explanation of symbols

1 Photoconductor (image carrier)
2 Primary charging device (charging member)
DESCRIPTION OF SYMBOLS 3 Exposure optical system 4 Developing apparatus 5 Developer carrier 6 Toner layer thickness control member 7 Toner stirring means 8 Developing bias power supply 9 Transfer apparatus 10 Transfer current generator 11 Cleaning means (cleaning member)
DESCRIPTION OF SYMBOLS 12 Fixing device 13 One-component magnetic toner 14 Waste toner container 15 Toner container 21 Flat sea throw cell 22 Strobe 23 Objective lens 24 CCD camera 25 Waste liquid chamber 26 Sheath liquid chamber 27 Supply source

Claims (4)

One-component magnetic toner for electrostatic charge development comprising toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, that the maximum permeability of maximum magnetic permeability of the magnetic fine particles contained (a) ([mu] m _a) and externally added to the magnetic particles in the toner particles (B) and ([mu] m _B) satisfies the following relationship formula (1) One-component magnetic toner for electrostatic charge development.
μm _B / μm _A ≦ 1.8 (1) 2. The one-component magnetic toner for electrostatic charge development according to claim 1, wherein the cumulative proportion of toner having a particle size of 0.6 [mu] m to 4 [mu] m is 10 to 50% by number. A process cartridge that integrally includes at least one selected from an image carrier, a cleaning member, and a charging member, and a developing device, and is detachably attached to an electrophotographic apparatus,
The developing device is provided in contact with the housing portion for housing the developer, the developer carrying body having the nonmagnetic sleeve having the fixed magnet therein, and carrying the developer on the nonmagnetic sleeve, and the developer carrying body. A regulating member that regulates the amount of the developer on the developer carrying member,
The developer includes toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, and the magnetic fine particles contained in the toner particles. One-component magnetism for electrostatic charge development in which the maximum permeability (μm _A ) of ( _A ) and the maximum permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles satisfy the relationship of the following formula (1): A process cartridge which is toner.
μm _B / μm _A ≦ 1.8 (1) A process cartridge remanufacturing method that integrally includes at least one selected from an image carrier, a cleaning member, and a charging member, and a developing device, and is detachably attached to an electrophotographic apparatus,
The developing device is provided in contact with the housing portion for housing the developer, the developer carrying body having the nonmagnetic sleeve having the fixed magnet therein, and carrying the developer on the nonmagnetic sleeve, and the developer carrying body. A regulating member for regulating the amount of the developer on the developer carrying member;
The process cartridge is removed from the electrophotographic apparatus when the developer is used up or the process cartridge cannot perform the desired performance, and has a means for storing or displaying usage history information of the process cartridge;
According to the usage history information, the reproduction method can be used again by attaching or re-installing the electrophotographic apparatus by cleaning or exchanging the members or the developing apparatus constituting the process cartridge or supplying the developer to the developing apparatus. The process of re-production,
Storing or displaying updated use history information of a process cartridge in the means for storing or displaying the use history when the reproduction is performed;
The developer includes toner particles containing at least magnetic fine particles (A) and a binder resin, and magnetic fine particles (B) externally added to the toner particles, and the magnetic fine particles contained in the toner particles. One-component magnetism for electrostatic charge development in which the maximum permeability (μm _A ) of ( _A ) and the maximum permeability (μm _B ) of the magnetic fine particles (B) externally added to the toner particles satisfy the relationship of the following formula (1): A process cartridge remanufacturing method, wherein the process cartridge is toner.
μm _B / μm _A ≦ 1.8 (1)

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