JP2005157270A - Developer carrying member and developing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier which is obtained by forming a resin coating layer having a uniform surface shape on a surface of a developer carrier, and in which the resin coating layer has good durability even when repeatedly used in any environment over a prolonged period of time, and to provide a developing apparatus using the developer carrier. <P>SOLUTION: The developer carrier is used in the developing apparatus for converting an electrostatic latent image formed on an electrostatic latent image carrier to a visible image by development with a developer carried and conveyed by a developer carrier. The developer carrier comprises at least a substrate and the resin coating layer on a surface of the substrate, wherein the resin coating layer contains at least a binder resin and graphitized particles, and an average value A and a standard deviation σ obtained from a hardness distribution of universal hardness measurements HU of a surface of the resin coating layer are 100≤A≤800 [N/mm<SP>2</SP>] and σ<30 [N/mm<SP>2</SP>], respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a developing device for forming a toner image by developing an electrostatic latent image formed on an electrostatic latent image carrier such as an electrophotographic photosensitive member or an electrostatic recording derivative with a developer in electrophotography. In addition, the present invention relates to a developer carrying member used in the above, and further to a developing device using the developer carrying member. Furthermore, the present invention relates to a developer carrier having an improved resin coating layer provided on a substrate of the developer carrier, and further relates to a developing device using the developer carrier.

  Conventionally, electrophotography uses a photoconductive substance, forms an electrostatic latent image on an electrostatic latent image carrier (photosensitive drum) by various means, and then develops the electrostatic latent image with toner. The toner image is developed with an agent to form a toner image. If necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat, pressure, or heating-pressurization to produce a copy. Or to obtain a print. Development methods in electrophotography are divided into a one-component development method that does not require a carrier and a two-component development method that has a carrier.

  The one-component development method includes a powder cloud method in which toner is used in a sprayed state, and development is performed by directly contacting the toner on a developer carrier having flexibility or elasticity with the surface of the electrostatic latent image carrier. There is a contact development method and a jumping development method in which the toner is caused to fly toward the surface of the electrostatic latent image carrier by the action of an electric field between the electrostatic latent image carrier and the developer carrier without directly contacting the toner. In general, a contact one-component development method or a one-component jumping development method is used.

  A developing device using the one-component developing method does not require a carrier and does not require a toner and carrier density adjusting mechanism in the developing device, and thus has an advantage that the developing device itself can be reduced in size and weight.

As a toner used in such a developing method, a toner having a small particle diameter has recently been used in order to digitize an electrophotographic apparatus and further improve image quality. For example, in order to improve resolution and character sharpness and faithfully reproduce an electrostatic latent image, toner having a weight average particle diameter of about 4 to 10 μm is used. From the viewpoint of ecology, for the purpose of further reducing the power consumption of the device, to lower the toner fixing temperature to improve the toner fixing property, and to further reduce the size and weight of the electrophotographic device, In order to reduce waste toner, it is required to improve toner transfer efficiency. In order to improve the fixability of the toner, the glass transition point (Tg) of the binder resin used in the toner is lowered or the low molecular weight component in the molecular weight distribution of the binder resin is increased. Further, in order to improve the offset resistance of the toner, a method is known in which a wax that enhances the plasticity of the binder resin is added to the toner particles. In order to improve the transfer efficiency of the toner, a transfer efficiency improver having an average particle diameter of 0.1 to 3 μm and a hydrophobic silica fine powder having a BET specific surface area of 50 to 300 m ² / g are externally added to the toner particles. Also known is a method of spheroidizing toner particles by mechanical impact force.

  As a first method for controlling the charge amount of the toner, a charge control agent is added to the toner particles. However, dyes and pigments used as charge control agents tend to be easily fused to each member when added in a large amount to the toner particles.

  As a second method for controlling the charge amount of the toner, a method for optimizing the charge amount of the toner by using an appropriate material for the frictional charge imparting member has been proposed.

  In the developing device using the one-component developing method, when the toner passes between the developer carrier and the developer layer thickness regulating member and is thinned, it contacts the developer carrier and the developer layer thickness regulating member. Therefore, these members greatly influence the optimization of the charge amount of the toner. In particular, in the case of a developing device using the magnetic one-component developing method, the magnetic toner moves on the developer carrying member due to the magnetic force of a magnet built in the developer carrying member. The selection of the developer carrier material has a great influence on the chargeability of the magnetic toner.

  As the developer carrying member used in the one-component developing method, in the contact developing method, an elastic body such as urethane rubber, EPDM rubber or silicone rubber is formed into a cylindrical shape on a main shaft of a metal such as stainless steel, or aluminum. In general, an elastomer layer is formed on the surface of a cylindrical member of stainless steel. In this case, the elastic body contains components such as a plasticizer, a vulcanizing agent, a release agent, and a low molecular weight component. In order to prevent these components from bleeding from the elastic body and adversely affecting each member, it has been proposed to provide a barrier layer or a protective layer on the surface of the elastic body layer. Further, it has been proposed to form a surface layer on the outermost surface using a material having good releasability and a resin having good charge imparting property for the toner.

  In Patent Documents 1 and 2, as a developer carrying member (developing sleeve) used in a non-contact type one-component developing method, a conductive material such as carbon black or graphite is contained in a binder resin having good charge imparting properties. A developing sleeve has been proposed in which a resin coating layer in which a solid lubricant is dispersed is formed on the surface of the developing sleeve. However, the influence of the surface shape of the developing sleeve is great. Therefore, if the surface shape of the developing sleeve changes due to repeated use, it is difficult to stabilize the toner coating amount and the developability tends to become unstable. A low-capacity process cartridge that does not require much durability can provide sufficient performance, but in the case of a high-capacity process cartridge that requires high durability, the surface shape of the developing sleeve changes due to scraping of the resin coating layer. And the toner coating amount tends to change greatly. The change in the toner coating amount also affects the chargeability of the toner because the frequency of sliding between the toner and the developing sleeve changes.

  Patent Document 3 proposes a developing sleeve in which spherical fine particles are added to the surface of the developing sleeve to form irregularities on the surface of the developing sleeve. The method of adding spherical particles is a good means for forming a uniform uneven surface shape and stabilizing the toner coating amount. However, in the long-term repeated use and the development method in which the surface of the developing sleeve is subjected to strong stress, when spherical resin particles are used as the spherical fine particles, scraping occurs during repeated use over a long period of time. The surface roughness of the resin coating layer is reduced, the toner coating amount is reduced, and toner fusing is likely to occur.

Patent Document 4 proposes a developing sleeve in which conductive spherical particles having a true density of 3 g / cm ³ or less are added to the resin layer of the developing sleeve to form irregularities on the surface of the developing sleeve. In such a developing sleeve, since the coating amount of the toner is stabilized and the wear resistance of the conductive spherical particles themselves is good, the stress of the toner between the developing sleeve and the regulating member is relieved, and the resin The durability of the coating layer itself is improved. However, the resin portion existing between the conductive spherical particles is selectively scraped by repeated use over a long period of time or by rubbing with the toner, and the surface roughness of the resin coating layer changes. The amount of coating tends to change.

In a developing device using a one-component developing method, a developing sleeve in which the resin coating layer forming the surface layer of the developing sleeve is further improved is desired.
Japanese Patent Laid-Open No. 02-105181 (lower column on page 2) Japanese Unexamined Patent Publication No. 03-036570 (2nd page) Japanese Patent Laid-Open No. 03-200986 (lower right column on page 3) Japanese Patent Laid-Open No. 08-240981 (paragraph 0008)

  The object of the present invention is to form a resin coating layer having a uniform surface shape on the surface of the developer carrying member, and the resin coating layer has good durability even when used repeatedly for a long time in each environment. , A developer carrying member that is less prone to selective scraping on the resin coating layer, suppresses changes in surface roughness, controls the toner coating amount to a constant amount, and gives the toner an appropriate charge amount And a developing device using the developer carrying member.

  In addition, the object of the present invention is that problems such as low image density, fogging, and character scattering are less likely to occur even with repeated use over a long period of time in each environment, and a high-quality image can be stably obtained. , A developer carrying member that hardly causes fusing of toner and a rubbing scratch on the surface of the developer layer thickness regulating member and hardly causes streaks and unevenness in a toner image, and a developing device using the developer carrying member are provided. It is to be.

It is an object of the present invention to develop a developer carrying member used in a developing device that develops an electrostatic latent image formed on an electrostatic latent image bearing member with a developer carried on the developer bearing member and visualizes it. In the body,
The developer carrier has a resin coating layer on at least the substrate and the substrate surface,
The resin coating layer contains at least a binder resin, and graphitized particles having a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95,
The surface of the resin coating layer has the following formula (1)
Universal hardness value HU = K × F / h ² [N / mm ² ] (1)
[Wherein, K represents a constant, F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter. ]
The average value A and the standard deviation σ determined from the hardness distribution of the measured value HU of the universal hardness in the surface film physical property test calculated in
100 ≦ A ≦ 800 [N / mm ² ],
σ <30 [N / mm ² ]
Another object is to provide a developer carrying member.

Another object of the present invention is to provide a developer container, a developer carrier for carrying and transporting the developer contained in the developer container, and a developer disposed near or in pressure contact with the developer carrier. A developer layer thickness regulating member for forming a thin layer of developer on the developer carrying member, and carrying and transporting the developer to the developing region facing the electrostatic latent image carrying member by the developer carrying member; In the present apparatus for developing the electrostatic latent image formed on the electrostatic latent image carrier with a developer to form a toner image,
The developer carrier has a resin coating layer on at least the substrate and the substrate surface,
The resin coating layer contains at least a binder resin, and graphitized particles having a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95,
The surface of the resin coating layer has the following formula (1)
Universal hardness value HU = K × F / h ² [N / mm ² ] (1)
[Wherein, K represents a constant, F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter. ]
The average value A and the standard deviation σ determined from the hardness distribution of the measured value HU of the universal hardness in the surface film physical property test calculated in
100 ≦ A ≦ 800 [N / mm ² ],
σ <30 [N / mm ² ]
Another object is to provide a developing device.

  According to the present invention, a resin coating layer having a uniform surface shape is formed on the surface of a developer carrying member, and the resin coating layer has good durability even when used repeatedly over a long period of time in each environment. , A developer carrying member that is less prone to selective scraping on the resin coating layer, suppresses changes in surface roughness, controls the toner coating amount to a constant amount, and gives the toner an appropriate charge amount And a developing device using the developer carrying member can be provided.

  In addition, according to the present invention, problems such as low image density, fogging, and scattering of characters are less likely to occur due to repeated use over a long period of time in each environment, and high-quality images can be stably obtained. , A developer carrying member that hardly causes fusing of toner and a rubbing scratch on the surface of the developer layer thickness regulating member and hardly causes streaks and unevenness in a toner image, and a developing device using the developer carrying member are provided. can do.

  By adopting the above-described configuration, the present inventors can uniformize the shape of the coating layer surface of the resin coating layer on the surface of the developer carrying member at the initial stage of durability. The change in the surface roughness of the layer is small, the change in the toner coat amount is also small, the toner can be properly charged even in the latter half of the endurance of many sheets, and a good image can be obtained over a long period of time even in each environment. The effect of being able to be found.

  The present invention will be described in more detail with reference to FIG.

  FIG. 1 is a schematic view showing a cross section of a developer carrying member (developing sleeve) of the present invention. The developing sleeve includes a magnet 5 having a predetermined magnetic force and magnetic pole configuration incorporated in a cylindrical substrate 4, and graphitized particles 1 are uniformly dispersed in the binder resin 2 on the surface of the substrate 4. A resin coating layer 3 having a uniform surface shape is formed.

  The graphitized particles 1 used for the resin coating layer 3 on the surface of the developing sleeve of the present invention have a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95 and exhibit good conductivity. Therefore, the toner charge can be optimized, and the wear resistance is superior compared to conventional graphite particles such as graphite. The amount of toner coating can be stabilized over a long period of time.

The resin coating layer 3 on the surface of the developing sleeve of the present invention contains at least graphitized particles 1 having excellent wear resistance, and an average value A and standard deviation obtained from the hardness distribution of the universal hardness measurement value HU. σ is 100 ≦ A ≦ 800 [N / mm ² ] and σ <30 [N / mm ² ], respectively. Preferably, the resin coating layer 3 on the surface of the developing sleeve of the present invention has an arithmetic average roughness Ra (hereinafter also abbreviated as “low Ra type”) of 0.20 to 0.70 μm according to JIS-B0601. . The developing sleeve of the present invention does not cause selective abrasion to the coating layer as compared with a low Ra type of graphite particles such as conventional graphite, and also when abrasion occurs due to repeated use over a long period of time. The surface of the coating layer can be evenly shaved and has minute irregularities to maintain low Ra, thereby suppressing changes in the surface shape of the coating layer and further stabilizing the charge amount and toner coat amount of the toner. The effect that can be demonstrated.

  Next, the developer carrying member of the present invention and the developing device using the same will be described in more detail.

  The graphitized particles 1 used for the resin coating layer 3 of the developer carrying member of the present invention will be described.

  The graphitized particles 1 used in the present invention have a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95.

Graphitization degree p (002) is said to be Franklin's p value, and d (002) = 3.440-0 by measuring the lattice spacing d (002) obtained from the X-ray diffraction pattern of graphite. .086 (1-P ² ). This p value indicates the proportion of the disordered portion of the carbon hexagonal mesh plane stack, and the smaller the p value, the greater the degree of graphitization.

  Graphitized particles 1 used in the present invention are obtained by using a bone agent such as coke which is used in a resin coating layer on the surface of a developer carrier in Japanese Patent Laid-Open No. 02-105181 or Japanese Patent Laid-Open No. 03-036570. The raw material and the manufacturing process are different from crystalline graphite made of artificial graphite or natural graphite obtained by hardening with pitch and firing at about 1000 to 1300 ° C. and then graphitizing at about 2500 to 3000 ° C. The graphitized particles 1 used in the present invention are slightly lower in graphitization than the previously used crystalline graphite, but have high conductivity and lubricity similar to the conventional crystalline graphite. Further, unlike the conventional graphite graphite flakes or needles, the particles are generally spherical and have a relatively high hardness. Therefore, since the developer carrying member of the present invention has a resin coating layer containing graphitized particles having good conductivity and high lubricity, the charge amount of the toner can be optimized, and the surface of the coating layer can be optimized. It is possible to suppress the fusion of the toner to the toner. Further, since the graphitized particles having the shape as described above are easily dispersed uniformly in the resin coating layer, the surface of the resin coating layer is given a uniform surface shape and abrasion resistance, and the graphitized particles themselves Since the shape is difficult to change, the resin coating layer can be prevented from being scraped even by repeated use over a long period of time, and the charge amount and toner coat amount of the toner can be stabilized over a long period of time.

  The graphitization degree p (002) of the graphitized particles used in the present invention is 0.20 ≦ p (002) ≦ 0.95, and more preferably 0.25 ≦ p (002) ≦ 0.75. preferable.

  When the graphitization degree p (002) exceeds 0.95, the wear resistance is excellent, but the conductivity and lubricity are lowered, and the image density is reduced due to the toner charge-up phenomenon, and blotches are generated. Further, when an elastic member is used as the restricting member, a rubbing scratch may occur on the surface of the restricting member, and streaks and unevenness are likely to occur in the solid image. When the degree of graphitization p (002) is less than 0.20, the mechanical strength of the coating layer may decrease due to the decrease in the wear resistance of the graphitized particles, and the selective abrasion of the coating layer may occur. Image defects are likely to occur. The graphitized particles used in the present invention have good conductivity and high lubricity by setting the degree of graphitization p (002) to 0.20 ≦ p (002) ≦ 0.95, and the resin coating layer. It is possible to prevent the mechanical strength of the resin from being lowered and to suppress selective scraping of the resin coating layer. Furthermore, by setting the graphitization degree p (002) of the graphitized particles to a specific range, the hardness of the graphitized particles is close to the hardness of the resin, so that when the surface of the resin coating layer is worn, By uniformly shaving, the graphitized particles are exposed again from the resin coating layer, so that the change in the surface composition is small, and uniform fine irregularities can be maintained in the surface shape.

  The graphitized particles used in the present invention preferably have a volume average particle size of 0.5 to 4.0 μm. The surface roughness of the resin coating layer of the present invention is preferably such that the arithmetic average roughness Ra of JIS-B0601 is 0.20 to 0.70 μm, so that the volume average particle diameter of the graphitized particles is less than 0.5 μm. The effect of imparting uniform roughness to the surface of the resin coating layer is small, and it becomes difficult to set the surface roughness Ra to 0.20 μm or more, and the rapid and uniform charge imparting property to the developer is lowered. The toner charge-up phenomenon due to abrasion of the surface of the resin coating layer tends to cause image density reduction and blotch. In the case of graphitized particles, when the volume average particle diameter exceeds 4.0 μm, it becomes difficult to set the surface roughness Ra of the resin coating layer to 0.70 μm or less, or depending on repeated use over a long period of time. As the surface roughness of the resin coating layer increases and the amount of toner coating increases, image defects such as a decrease in image density due to insufficient charging of the toner, fogging, and scattering of characters are likely to occur. The graphitized particles used in the present invention have a volume average particle size of 0.5 to 4.0 μm, so that the surface roughness of the coating layer can be easily controlled, and the toner charge amount and the toner coating layer can be further increased. Can be stabilized.

  As a method for obtaining graphitized particles used in the present invention, the following methods are preferred. It is not necessarily limited to these methods.

  As a method for obtaining graphitized particles used in the present invention, graphitization using particles consisting of a single phase that is optically anisotropic, such as mesocarbon microbeads and bulk mesophase pitch, is used as a raw material. It is preferable for increasing the graphitization degree of the graphitized particles and maintaining the spherical shape. The optical anisotropy of the raw material is caused by the lamination of aromatic molecules, and the order is further developed by the graphitization treatment, and graphitized particles having a high degree of graphitization are obtained.

  When bulk mesophase pitch is used as a raw material for obtaining graphitized particles used in the present invention, it is preferable to use bulk mesophase pitch that is softened and melted by heating in order to obtain spherical and highly graphitized particles. For example, the bulk mesophase pitch is a mesophase pitch obtained by extracting β-resin from the coal tar pitch by solvent fractionation and hydrogenating the β-resin for heavy treatment. Further, mesophase pitch obtained by pulverizing after the heavy treatment of β-resin and then removing the solvent soluble component with benzene or toluene can also be used. The bulk mesophase pitch preferably has a quinoline soluble content of 95% by mass or more. When the amount less than 95% by mass is used, the inside of the particles is hard to be liquid phase carbonized, and solid phase carbonization is performed, so that the shape of the carbonized particles remains crushed and it is difficult to obtain a spherical shape.

  Next, as a method for graphitizing the mesophase pitch, the bulk mesophase pitch is finely pulverized to a volume average particle diameter of 1 to 6 μm to obtain particles, and the particles are heat-treated in air at about 200 ° C. to about 350 ° C. As a result, it is lightly oxidized. By this oxidation treatment, the bulk mesophase pitch particles are infusible only on the surface, and the melting and fusion of the particles during the subsequent graphitizing heat treatment are prevented. The oxidized mesophase pitch particles preferably have an oxygen content of 5% by mass to 15% by mass. If it is less than 5% by mass, the particles at the time of heat treatment are likely to be fused with each other, and if it exceeds 15% by mass, the inside of the particle is oxidized and graphitized in a crushed form, making it difficult to obtain a spherical product . Next, desired graphitized particles are obtained by heat-treating the oxidized bulk mesophase pitch particles at 2000 ° C. to 3500 ° C. in an inert atmosphere such as nitrogen or argon.

  In addition, a method for obtaining mesocarbon microbeads, which are another preferred raw material for obtaining graphitized particles used in the present invention, is obtained by heating coal-based heavy oil or petroleum-based heavy oil at a temperature of 300 ° C to 500 ° C. After heat treatment and polycondensation to produce crude mesocarbon microbeads, the reaction product is subjected to treatment such as filtration, stationary sedimentation, and centrifugal separation, and then the mesocarbon microbeads are separated, followed by benzene, toluene, and xylene. This is a method of obtaining mesocarbon microbeads by washing the mesocarbon microbeads with such a solvent and further drying. As a method of graphitization using mesocarbon microbeads, it is possible to prevent the coalescence of the particles after graphitization by first mechanically dispersing mesocarbon microbeads that have been dried, with a gentle force that does not destroy them. It is preferable for obtaining a uniform particle size. The mesocarbon microbeads that have finished the primary dispersion are subjected to primary heat treatment at a temperature of 200 ° C. to 1500 ° C. in an inert atmosphere and carbonized. Carbide particles that have undergone the primary heat treatment are mechanically dispersed with a mild force that does not destroy the carbide particles, preventing coalescence of the particles after graphitization and uniform particle size. It is preferable to obtain The carbide particles after the secondary dispersion treatment are subjected to secondary heat treatment at 2000 to 3500 ° C. in an inert atmosphere to obtain desired graphitized particles.

  Moreover, it is preferable that the obtained graphitized particles have a uniform particle size distribution to some extent by classification in order to make the surface shape of the resin coating layer uniform.

  Moreover, 2000-3500 degreeC is preferable and the firing temperature of graphitized particle | grains has more preferable 2300 degreeC-3200 degreeC. When the firing temperature is lower than 2000 ° C., the graphitized particles have a low graphitization degree, and the conductivity and lubricity are lowered, which may cause image density reduction and blotch due to toner charge-up phenomenon, Further, when an elastic member is used as the restricting member, rubbing scratches may occur on the surface of the restricting member, and streaks and unevenness are likely to occur in the solid image. When the firing temperature is higher than 3500 ° C., the degree of graphitization of the graphitized particles may be too high, so that the hardness of the graphitized particles is lowered and the wear resistance of the graphitized particles is reduced. As a result, the mechanical strength of the coating layer decreases, and the coating layer may be selectively scraped off, which is likely to cause image defects.

  The content of graphitized particles dispersed in the resin coating layer is preferably 2 to 150 parts by mass, more preferably 4 to 100 parts by mass with respect to 100 parts by mass of the binder resin in the coating layer. Particularly favorable results are given. When the content of the graphitized particles is less than 2 parts by mass, the effect of adding the graphitized particles is small. When the content of the graphitized particles exceeds 150 parts by mass, the adhesion of the resin coating layer is lowered and the wear resistance is reduced. May end up.

  Next, the average value A and the standard deviation σ obtained from the surface roughness, hardness and hardness distribution of the resin coating layer in the present invention will be described.

The surface of the resin coating layer has the following formula (1)
Universal hardness value HU = K × F / h ² [N / mm ² ] (1)
[Wherein, K represents a constant, F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter. ]
The average value A and the standard deviation σ obtained from the hardness distribution of the universal hardness measurement value HU in the surface film physical property test on the surface of the resin coating layer calculated in
100 ≦ A ≦ 800 [N / mm ² ],
σ <30 [N / mm ² ]
Set to

  As for the surface of a resin coating layer, it is preferable that arithmetic mean roughness Ra of JIS-B0601 is set to 0.20-0.70 micrometer.

  The preferred surface roughness Ra differs depending on the developing method. However, as shown in FIG. 2, a developing device having a magnetic blade arranged with a gap between the developing sleeve and the developing sleeve as shown in FIG. In a developing device having an elastic blade pressed against the developing sleeve with a predetermined pressing pressure as the regulating member 302, in a thin layer system in which a magnetic toner having a small particle diameter is thinly coated on the developing sleeve, a resin coating is used. The surface roughness of the surface of the layer is preferably low Ra, and Ra is preferably 0.20 to 0.70 μm. If it is smaller than 0.20 μm, the toner coating amount is small, and the low image density due to the small toner coating amount, the toner charge-up phenomenon, and the blotch tend to occur. On the other hand, if it is larger than 0.70 μm, the toner coating amount tends to be increased, the uniformity of frictional charging to the toner is lowered, and characters are scattered and fogged, and image density is reduced due to insufficient toner charging. It becomes easy to do.

When the average value A obtained from the hardness distribution of the universal hardness measurement value HU on the surface of the resin coating layer is smaller than 100 N / mm ² , the resin coating layer is easily scraped, wear resistance is reduced, and image defects occur. It becomes easy. When the average value A is greater than 800 N / mm ² , the developer layer thickness regulating member is applied to a developing device of a type (elastic regulating blade) in which the developer layer thickness regulating member is elastically pressed against the developing sleeve (via toner). Since the surface of the elastic regulating blade is easily scratched at the initial stage of endurance of a large number of sheets, toner coating unevenness is likely to occur, solid images are likely to cause streaks and unevenness, and image quality is likely to deteriorate. The average value A obtained from the hardness distribution on the surface of the resin coating layer is preferably in the range of 100 ≦ A ≦ 800 [N / mm ² ], but in order to suppress the deterioration of the image quality over a longer period of time, The average value A is more preferably in the range of 200 ≦ A ≦ 700 [N / mm ² ]. Further, when the standard deviation σ obtained from the hardness distribution of the universal hardness measurement value HU on the surface of the resin coating layer is 30 N / mm ² or more, even if the shape of the surface of the coating layer in the initial stage of the durability of many sheets is uniform As the durability of a large number of sheets increases, the surface roughness of the resin coating layer tends to increase because wear selectively occurs from a portion having a low hardness on the surface of the resin coating layer. As a result, the amount of toner coating increases in the latter half of the endurance of a large number of sheets, and fogging and character scattering are likely to occur particularly under low temperature and low humidity. Further, even when the standard deviation σ is smaller than 30 N / mm ² , in the conventional coating layer using graphite particles such as graphite, wear occurs selectively from the convex portions on the surface of the coating layer. The surface roughness tends to be small. As a result, toner charge-up phenomenon and blotches are likely to occur, especially at low temperatures and low humidity, and image degradation such as image density reduction and solid image streaks and unevenness due to insufficient toner coating amount, especially at high temperatures and high humidity. Is likely to occur. In addition, when a low-temperature fixable toner is used, it tends to cause toner fusion to the developing sleeve.

  Next, in the present invention, the binder resin used for the resin coating layer includes phenolic resin, epoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyolefin resin, silicone resin, and fluorine resin. Styrene resin, vinyl resin, cellulose resin, melamine resin, urea resin, polyurethane resin, polyimide resin, and acrylic resin. In consideration of mechanical strength, a thermosetting or photocurable resin is more preferable, but a thermoplastic resin can also be applied as long as it has sufficient mechanical strength.

In the present invention, the resin coating layer formed on the surface of the developing sleeve by the above-described forming material is adhered to the surface of the developing sleeve due to toner charge-up, or from the surface of the developing sleeve that occurs due to toner charge-up. In order to suppress poor charging of toner, it is preferable that the toner is conductive. The volume resistance value of the resin coating layer is preferably 10 ⁵ Ω · cm or less, more preferably 10 ³ Ω · cm or less. If the volume resistance value of the resin coating layer on the surface of the developing sleeve exceeds 10 ⁵ Ω · cm, poor charge application to the toner is likely to occur, and as a result, charge-up phenomenon and blotch are likely to occur.

  In the present invention, in order to adjust the resistance value of the resin coating layer to the above value, the following conductive materials may be contained in the resin coating layer. Examples of the conductive fine powder used at this time include fine powders of metal powders such as aluminum, copper, nickel and silver; antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide and titanium. Examples include metal oxides such as potassium acid; carbon fibers; carbon blacks such as furnace black, lamp black, thermal black, acetylene black, and channel black; carbons such as graphite; and metal fibers. Of these, carbon black, especially conductive amorphous carbon, has excellent electrical conductivity, and can be given a certain degree of conductivity by filling the resin with conductivity or controlling the amount added. Therefore, it is preferably used. The dispersion stability when the resin composition is used as a paint can also be improved. In the present invention, when these conductive fine powders are used, the amount of the conductive fine powder added is preferably in the range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin. If it is less than 1 part by weight, it is difficult to lower the resistance value of the coating layer to a desired level, and toner fusion to the binder resin used for the coating layer of the developing sleeve tends to occur. When the amount exceeds 100 parts by weight, the strength (wearability) of the coating layer tends to decrease particularly when a fine powder having a particle size on the order of submicron is used.

  In the present invention, a solid lubricant may be dispersed in the resin coating layer, and generally known solid lubricants can be used. Examples thereof include fatty acid metal salts such as graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-selenium niobium, calcium chloride-graphite, talc, and zinc stearate. In particular, graphite is preferably used because it does not impair the conductivity of the resin coating layer. The addition amount of the solid lubricant is preferably in the range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin. If the amount is less than 1 part by weight, the effect of improving the toner fusion to the binder resin surface of the resin coating layer is small. On the other hand, if it exceeds 100 parts by weight, a material containing a large amount of fine powder having a submicron order particle size is used. When it exists, there exists a tendency for the intensity | strength (wearability) of a resin coating layer to fall. As these solid lubricants, those having a volume average particle diameter of preferably 0.5 to 4.0 μm are used. When the volume average particle size of the solid lubricant is less than 0.5 μm, it is not preferable because sufficient lubricity is hardly obtained. When the volume average particle size exceeds 4.0 μm, the shape of the resin coating layer surface is reduced. The surface effect is likely to be non-uniform and the toner is uniformly frictionally charged, and the strength of the coating layer is not preferable.

  In the present invention, it is also possible to use the resin coating layer in combination with graphitized particles and to add a charge control agent as necessary in order to further stabilize the chargeability of the toner.

  As the negatively chargeable control agent, an organometallic salt, an organometallic complex, or a chelate compound is effective. For example, a monoazo metal complex, an acetylacetone metal complex, a metal complex or a metal salt of an aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid. Other examples include aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters and phenol derivatives such as bisphenol. These can be used alone or in combination of two or more.

  Examples of positively chargeable control agents include modified nigrosine modified with nigrosine and fatty acid metal salts; quaternary compounds such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. Phosphonium salts such as ammonium salts, tributylbenzylphosphonium-1-hydroxy-4-naphthosulfonate, tetrabutylphosphonium tetrafluoroborate and lake pigments thereof; triphenylmethane dyes and lake pigments thereof ( Phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanic acid, ferrocyanic compound, etc.); metal salts of higher fatty acids; dibutyltin oxide, dioctyltin Kisaido, such as diorganotin oxide dicyclohexyl tin oxide; dibutyl tin borate, dioctyl tin borate, include such diorgano tin borate dicyclohexyl tin borate. These can be used alone or in combination of two or more.

  In the present invention, as a charge control agent used for the purpose of improving the chargeability of a negatively chargeable toner and suppressing the chargeability of a positively chargeable toner, a nitrogen-containing heterocyclic ring as described in JP-A-10-293454 is used. A compound is preferably used. As methods for controlling the chargeability of the toner for the purpose of suppressing the chargeability of the negatively chargeable toner and improving the chargeability of the positively chargeable toner, Japanese Patent Laid-Open Nos. 10-3204040, 11-052711, and 11 A combination of a resin having a nitrogen-containing group and a quaternary ammonium salt compound as described in JP-A No. 249414 is preferably used.

  In the present invention, it is also possible to use spherical particles (hereinafter referred to as concavo-convex forming particles) for forming irregularities on the surface of the coating layer in combination with graphitized particles in the resin coating layer.

  Examples of such irregularity-forming particles include resin particles of vinyl polymers and vinyl copolymers such as polymethyl methacrylate, polyethyl acrylate, polybutadiene, polyethylene, polypropylene, and polystyrene; benzoguanamine resins, phenol resins, polyamides, Resin particles of fluororesin, silicone resin, epoxy resin, polyester resin; oxide particles such as alumina, zinc oxide, silica, titanium oxide, tin oxide; carbon particles; conductivity such as resin particles subjected to a conductive treatment Particles. It is also possible to use an organic compound such as a charge control agent described later in the form of particles. In this case, it also serves to impart triboelectric charge to the toner.

Of these irregularities-forming particles, spherical resin particles produced by suspension polymerization or dispersion polymerization are preferably used as the resin particles. Here, the spherical shape refers to particles having a major axis / minor axis ratio of 1.0 to 1.5. It is preferable to use particles having a major axis / minor axis ratio of 1.0 to 1.2, more preferably spherical particles. Spherical resin particles can obtain a suitable surface roughness with a smaller addition amount, and a uniform surface shape can be easily obtained. Examples of such spherical resin particles include acrylic resin particles such as polyacrylate and polymethacrylate; polyamide resin particles such as nylon; polyolefin resin particles such as polyethylene and polypropylene; silicone resin particles, phenolic resin particles, Examples include polyurethane resin particles, styrene resin particles, and benzoguanamine particles. The resin particles obtained by the pulverization method may be used after thermally or physically spheroidizing.
When the irregularity-forming particles are spherical, the contact area with the developer layer thickness regulating member to be pressed is reduced, so that the increase in sleeve rotation torque due to frictional force and toner adhesion can be reduced. preferable.

The surface of such spherical resin particles may be used with inorganic fine powder attached thereto or fixed thereto. Examples of the inorganic fine powder include SiO ₂ , SrTiO ₃ , CeO ₂ , CrO, Al ₂ O ₃ , ZnO, MgO, TiO ₂ , oxides such as Si ₃ N ₄ , carbides such as SiC, CaSO ₄ , Sulfates such as BaSO ₄ ; carbonates such as CaCO ₃ .

  The inorganic fine powder may be used after being treated with a coupling agent. In particular, a coupling agent can be preferably used for the purpose of improving the adhesion to the binder resin or for imparting hydrophobicity to the particles. Examples of such coupling agents include silane coupling agents, titanium coupling agents, and zircoaluminate coupling agents. More specifically, silane coupling agents include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyl. Dimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethyldi Ethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyl Dimethylpolysiloxane having 2 to 12 siloxane units per molecule and having hydroxyl groups bonded to one silicon atom each in a terminal unit and having 2 to 12 siloxane units per molecule. Can be mentioned. By treating the surface of the spherical resin particles with inorganic fine powder in this way, dispersibility in the paint, uniformity of the coating surface, stain resistance of the coating layer surface, charge imparting property to the toner, coating The wear resistance of the layer can be improved.

  In order to further improve the stain resistance and wear resistance of the surface of the coating layer, it is more preferable to impart conductivity to the unevenness forming particles. As the conductive spherical particles, the surface of metal oxide particles such as titanium oxide, niobium oxide, manganese oxide, lead oxide or pigment particles such as barium sulfate is coated with a good conductive material such as tin oxide. Conductive conductive spherical particles, or spherical particles made conductive by doping metals having different oxidation numbers into an insulating metal oxide such as zinc oxide, copper oxide, iridium oxide, and further, Examples thereof include conductive spherical particles described in 240981.

The volume resistivity of such conductive spherical particles is preferably 10 ⁶ Ω · cm or less, more preferably 10 ⁻³ to 10 ⁶ Ω · cm. When the volume resistance exceeds 10 ⁶ Ω · cm, toner contamination and fusion are likely to occur due to the spherical particles exposed on the surface of the resin coating layer due to abrasion, and rapid and uniform charging is difficult to be performed. . This is because by imparting conductivity to the spherical particles, it is difficult for charges to accumulate on the surface of the spherical particles due to the conductivity, and toner adhesion can be reduced and toner chargeability can be improved.

The true density of the irregularity-forming particles to be added is preferably ³ g / cm ³ or less. When the true density exceeds ³ g / cm ³ , the true density difference from the binder resin becomes large, and therefore, the dispersion state of the unevenness forming particles tends to be non-uniform during the production of the coating material for forming the resin coating layer. The dispersion state of the unevenness forming particles in the resin coating layer also tends to be non-uniform. Therefore, it becomes difficult to impart a uniform roughness to the surface of the coating layer, uniform charging to the toner and insufficient strength of the coating layer, and contamination resistance and abrasion resistance, which are the advantages of these irregularities forming particles. There is a possibility that it will not be possible to demonstrate.

  Examples of the unevenness forming particles include spherical carbon particles, spherical resin particles surface-treated with a conductive substance, and spherical resin particles in which conductive fine particles are dispersed.

  The irregularity-forming particles preferably have a volume average particle size of 0.5 to 4.0 μm. When the volume average particle size is less than 0.5 μm, it is difficult to form uniform surface irregularities, and when an attempt is made to increase the surface roughness, the amount of addition becomes excessive, the resin coating layer becomes brittle, and the wear resistance tends to decrease. On the other hand, if the volume average particle size is larger than 4.0 μm, the unevenness forming particles protrude too much from the surface of the resin coating layer, so that the thickness of the toner coating layer becomes too large, and the toner charge is lowered, and the durability of a large number of sheets is increased. As the process proceeds, the surface roughness increases and the toner coating amount may change.

  In the present invention, the resin coating layer can be obtained by preparing a paint by dispersing and mixing each component in a solvent, and applying the paint onto a substrate described later. For dispersion mixing of each component, a known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, and a pearl mill can be suitably used. As a coating method, a dipping method, a spray method, or a roll coating method can be applied.

  The layer thickness of the resin coating layer is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 4 to 20 μm in order to obtain a uniform layer thickness.

  In the present invention, as the substrate of the developing sleeve having the resin coating layer, a metal, an alloy thereof or a compound thereof is preferably used. In particular, stainless steel, aluminum and alloys thereof formed into a cylindrical shape are preferably used. Of these, aluminum is preferable because of its excellent workability. For example, in the case of a cylindrical substrate, aluminum is particularly preferable because axial deflection, circumferential roundness, and mechanical accuracy are improved. The surface of these substrates may be further processed to have a predetermined surface roughness by blasting, filing or cutting, or may be processed by electrolytic plating or electroless plating.

  In the present invention, the substrate of the developing sleeve having the resin coating layer may have an elastic layer on the outer peripheral surface of a stainless steel core. As the elastic layer formed on the outer peripheral surface of the metal core, a material obtained by molding rubber such as silicone rubber or urethane rubber is preferably used. Furthermore, what contains the electrically conductive agent for adjusting an electrical resistance in rubber | gum is especially preferable. The elastic layer preferably has a predetermined hardness and surface roughness in order to improve the adhesion of the resin coating layer serving as the surface layer. An intermediate layer may be further provided on the surface of the elastic layer, and a resin coating layer may be formed on the intermediate layer. In addition, the surface of the cored base may be processed to a predetermined surface roughness by blasting, filing or cutting. The surface of the cored base may be treated by electrolytic plating or electroless plating.

  Next, a developing device using a developing sleeve having a resin coating layer will be described in detail.

  Examples of the developing device include developing devices schematically shown in FIGS. 2 and 3, an electrostatic latent image carrier (for example, a photosensitive drum) 301 carrying an electrostatic latent image formed by a known process is rotated in the direction of arrow A. A developing sleeve 308 as a developer carrying member carries a developer 304 made of a one-component magnetic toner housed in a developer container 303 and rotates in the direction of arrow B, thereby developing sleeve 308 and photosensitive drum 301. The developer 304 is transported to the development area D facing each other. As shown in FIGS. 2 and 3, the developing sleeve 308 has a resin coating layer 307 formed on a metal cylindrical tube 306 as a base. A magnet roller 305 is disposed in the developing sleeve 308 in order to magnetically attract and hold the developer 304 on the developing sleeve 308, and the magnet roller 305 is fixed. The developing sleeve 308 and the magnet roller 305 are in a non-contact state.

  In the developer container 303, by rotating in the direction of arrow C, stirring blades 309, 310 and 314 for stirring the developer 304, a screw 311 for supplying the developer 304 into the developer container 303, and the developer container 303 A stirring wall 312 is provided for adjusting the amount of developer inside.

  The developer 304 obtains a triboelectric charge that can develop the electrostatic latent image on the photosensitive drum 301 by friction between the magnetic toners and the resin coating layer 307 on the developing sleeve 308. In the example of FIG. 3, in order to regulate the layer thickness of the developer 304 conveyed to the development area D, a material having rubber elasticity such as urethane rubber or silicone rubber, or phosphor bronze as a developer layer thickness regulating member. An elastic regulating blade 302 made of an elastic plate made of a material having metal elasticity such as stainless steel is used. The elastic regulating blade 302 is pressed against the developing sleeve 308 in a posture opposite to the rotation direction of the developing sleeve 308 through the developer, and a thin layer of the developer 304 is formed on the developing sleeve 308. As the elastic regulating blade 302, a polyamide elastomer (PAE) is pasted on the surface of a phosphor bronze plate capable of obtaining a stable pressurizing force in order to provide a stable regulating force and a stable (negative) chargeability to the toner. It is preferable to use a structure. Examples of the polyamide elastomer (PAE) include a copolymer of polyamide and polyether.

  The contact pressure of the regulating member 302 for regulating the developer layer thickness with respect to the developing sleeve 308 is a linear pressure of 5 to 50 N / m, so that the regulation of the developer is stabilized and the developer layer thickness is suitably set. It is preferable at the point which can be made.

  When the contact pressure of the regulating member 302 for regulating the developer layer thickness is less than the linear pressure of 5 N / m, the regulation of the developer is weakened, which is likely to cause fogging and toner leakage. When it exceeds m, damage to the toner is likely to increase, and this tends to cause deterioration of the toner and fusion to the developing sleeve and the elastic regulation blade.

  In the present invention, instead of the elastic regulating blade, a magnetic regulating blade 302 made of a ferromagnetic metal as shown in FIG. 2 faces the developing sleeve 308 with a gap width of about 50 to 500 μm from the surface of the developing sleeve 308. Alternatively, a thin layer of the developer 304 may be formed on the developing sleeve 308 by hanging from the developer container 303 and concentrating the magnetic lines of force from the N pole of the magnet roller 305 on the magnetic regulation blade 302.

  The thickness of the thin layer of the developer 304 formed on the developing sleeve 308 in this manner is preferably thinner than the minimum gap between the developing sleeve 308 and the photosensitive drum 301 in the developing region D.

  The developing sleeve of the present invention is particularly effective when incorporated in a developing device (for example, a non-contact developing device) that develops an electrostatic latent image with a thin layer of developer. The developer carrier of the present invention is also applied to a developing device (contact type developing device) in which the thickness of the developer layer in the development region D is equal to or greater than the minimum gap between the developing sleeve 308 and the photosensitive drum 301. can do.

  In FIG. 4, an electrostatic latent image carrier (for example, a photosensitive drum) 301 carrying an electrostatic latent image formed by a known process is rotated in the direction of arrow A. A developing roller 318 as a developer carrying member carries a developer 304 formed of a one-component nonmagnetic toner contained in a developer container 303 and rotates in the direction of arrow B, thereby developing roller 318. The developer 304 is transported to the development area D where the upper developer layer is in contact with the photosensitive drum 301. As shown in FIG. 4, the developing roller 318 has an elastic layer 316 and a surface layer 317 formed on a metal support 315 as a base.

  The developer 304 obtains a triboelectric charge that can develop the electrostatic latent image on the photosensitive drum 301 by friction between the non-magnetic toners and the surface layer 317 on the surface of the developing roller 318. In the example of FIG. 4, in order to regulate the layer thickness of the developer 304 conveyed to the development area D, the developer layer thickness regulating member 302 similar to that in FIG. 3 is used, and further, as shown in FIG. The developer supply / peeling member 319 is used to supply the developer to the surface of the developing roller 318 and / or to strip off the developer on the surface of the developing roller 318.

  When the developer supply-peeling roller 319 made of an elastic roller is used as the developer supply-peeling member 319, the peripheral speed of the developer supply-peeling roller 319 is such that the surface rotates in the counter direction. It is preferably 20 to 120%, more preferably 30 to 100% with respect to 100% of the peripheral speed of the roller 318.

  When the peripheral speed of the developer supply-peeling roller 319 is less than 20%, the supply of the developer is insufficient, the followability of the solid image is deteriorated, and a ghost image is caused. When the peripheral speed exceeds 120% In addition, the developer supply amount increases, which causes fogging due to poor regulation of the developer layer thickness and insufficient charge amount, and further tends to cause damage to the toner, which is likely to cause fogging and toner fusion due to toner deterioration.

  When the rotation direction of the developer supply-peeling roller 319 is the same (forward) direction as the surface of the developing roller 318, the peripheral speed of the developer supply-peeling roller 319 is preferably relative to the peripheral speed of the developing roller. 100 to 300%, more preferably 101 to 200% is sufficient in terms of the amount of toner supplied.

  As for the rotation direction of the developer supply-peeling roller 319, it is more preferable to rotate in the counter direction with respect to the surface of the developing roller 318 in terms of stripping property and feeding property.

  The intrusion amount of the developer supply-peeling roller 319 with respect to the developing roller 318 is preferably 0.5 to 2.5 mm from the viewpoint of developer supply and stripping property.

  When the penetration amount of the developer supply-peeling roller 319 is less than 0.5 mm, a ghost is likely to occur due to insufficient peeling, and when the penetration amount exceeds 2.5 mm, the toner damage is large. Therefore, the toner is likely to cause fusing and fogging due to toner deterioration.

  In the following description, an example of the non-contact type developing device will be described.

  A developing bias voltage is applied to the developing sleeve 308 by a developing bias power source 313 as biasing means in order to cause the one-component developer 304 having magnetic toner carried on the developing sleeve 308 to fly. When a DC voltage is used as the development bias voltage, a voltage having a value between the potential of the image portion of the latent image (the region where the developer 304 adheres and the toner image is formed) and the background portion is developed. Application to the sleeve 308 is preferred.

  In order to increase the density of the developed image or improve the gradation, an alternating bias voltage may be applied to the developing sleeve 308 to form an oscillating electric field whose direction is alternately reversed in the developing region D. In this case, it is preferable to apply to the developing sleeve 308 an alternating bias voltage in which a DC voltage component having an intermediate value between the potential of the developed image portion and the background portion is superimposed. In the case of normal development in which a toner image is formed by attaching toner to a high potential portion of a latent image having a high potential portion and a low potential portion, toner that is charged with a polarity opposite to that of the electrostatic latent image is used. For reversal development in which a toner image is formed by attaching toner to the low potential portion of an electrostatic latent image having a high potential portion and a low potential portion, toner that is charged to the same polarity as the electrostatic latent image is used. To do. High potential and low potential are expressed in absolute values. In any of these cases, the developer 304 is charged by at least friction with the developing sleeve 308.

  2 to 4 schematically illustrate the developing device of the present invention, and there are various forms of the developer container 303, the presence or absence of the stirring blades 309 and 310, and the arrangement of the magnetic poles. These apparatuses can also be used for development using a two-component developer containing toner and carrier.

  Next, an example of an image forming apparatus using the developing device of the present invention illustrated in FIGS. 2 to 4 will be described with reference to FIG. The surface of the photosensitive drum 101 as an electrostatic latent image holding member is negatively charged by a contact (roller) charging unit 119 as a primary charging unit, and a digital latent image is formed on the photosensitive drum 101 by image scanning by laser beam exposure 115. Formed. Next, a developing device having an elastic regulating blade 111 as a regulating member for regulating the developer layer thickness, and having a developing sleeve 108 as a developer carrying member in which a multipolar permanent magnet 105 is included. Thus, the digital latent image is reversely developed by the one-component developer 104 having the magnetic toner in the hopper 103. As shown in FIG. 5, the conductive substrate of the photosensitive drum 101 is grounded in the developing region D, and an alternating bias, a pulse bias, and / or a DC bias is applied to the developing sleeve 108 by a bias applying unit 109. Next, when the recording material P such as paper is conveyed and arrives at the transfer section, voltage application means from the back surface (opposite side to the photosensitive drum side) of the recording material P by contact (roller) transfer means 113 as transfer means. By being charged at 114, the developed image (toner image) formed on the surface of the photosensitive drum 101 is transferred onto the recording material P by the contact transfer unit 113. Next, the recording material P separated from the photosensitive drum 101 is conveyed to a heat and pressure roller fixing device 117 as fixing means, and the fixing device 117 fixes the toner image on the recording material P. .

  The one-component developer 104 remaining on the photosensitive drum 101 after the transfer process is removed by a cleaning unit 118 having a cleaning blade 118a. When the amount of the remaining one-component developer 104 is small, the cleaning process can be omitted. The photosensitive drum 101 after cleaning is neutralized by erase exposure 116 as necessary, and the above process starting from the charging process by the contact (roller) charging unit 119 as the primary charging unit is repeated.

  In the above series of steps, the photosensitive drum (that is, electrostatic latent image carrier) 101 has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. A nonmagnetic cylindrical developing sleeve 108 which is a developer carrying member rotates so as to advance in the same direction as the surface of the photosensitive drum 101 in the developing region D. Inside the developing sleeve 108, a multi-pole permanent magnet (magnet roll) 105, which is a magnetic field generating means, is arranged so as not to rotate. The one-component developer 104 in the developer container 103 is applied and carried on the developing sleeve 108 and is tribocharged (for example, minus) due to friction with the surface of the developing sleeve 108 and / or friction between magnetic toners. Tribo charge). Further, the elastic regulating blade 111 is provided so as to elastically press the developing sleeve 108, and the thickness of the developer layer is made thin (30 μm to 300 μm) and uniformly regulated so that the photosensitive drum 101 and the developing sleeve in the developing region D are provided. A developer layer that is thinner than the gap with 108 is formed. By adjusting the rotation speed of the developing sleeve 108, the surface speed of the developing sleeve 108 is made substantially equal to or close to the speed of the surface of the photosensitive drum 101. In the developing region D, an AC bias or a pulse bias may be applied to the developing sleeve 108 as a developing bias voltage by the bias applying unit 109. As for this AC bias, f is preferably 200 to 4,000 Hz and Vpp is preferably 500 to 3,000 V.

  The developer (magnetic toner) in the development area D is transferred to the electrostatic latent image side by the electrostatic force on the surface of the photosensitive drum 101 and the development bias voltage such as an AC bias or a pulse bias.

  Instead of the elastic regulating blade 111, a magnetic doctor blade such as iron may be used. The primary charging unit has been described using the charging roller 119 as the contact charging unit as described above, but may be a contact charging unit such as a charging blade or a charging brush, or a non-contact corona charging unit. However, the contact charging means is preferable in that ozone generation due to charging is small. Although the transfer means has been described using the contact transfer means such as the transfer roller 113 as described above, a non-contact corona transfer means may be used. However, the contact transfer means is preferable in that ozone generation by transfer is small.

  Next, the toner used in the developing device of the present invention will be described. The toner is prepared from a fine powder in which a binder resin, a release agent, a charge control agent, a colorant, and the like are melt-kneaded, solidified and then pulverized, and the pulverized product is classified to obtain a uniform particle size distribution. As the binder resin used for the toner, a known binder resin can be used.

  For example, a styrene homopolymer; a homopolymer of a styrene derivative such as α-methylstyrene or p-chlorostyrene; a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate Copolymer, Styrene-dimethylaminoethyl methacrylate copolymer, Styrene-vinyl methyl ether copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene-male Acid copolymer, styrene-maleic acid Styrenic copolymers such as steal copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, temper resin, phenolic resin, aliphatic or Examples thereof include alicyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, and carnauba wax. These can be used alone or in combination.

  Colorants used in toners include carbon black, nigrosine dye, lamp black, Sudan black SM, first yellow G, benzidine yellow, pigment yellow, Indian first orange, irgadin red, paranitroaniline red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Bio Red B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant・ Green B, Phthalocyanine Green, Oil Yellow GG, Pomelo ・ First Yellow CGG, Kaya Set Y963, Kaya Set YG, Pomelo First Orange RR, Oil Scar Tsu door, the colorant Orasol Brown B, pomelo First Scarlet CG, include the oil pink OP.

  When the toner is a magnetic toner, the toner particles contain magnetic powder. As such magnetic powder, a substance that is magnetized in a magnetic field is used. Examples of the magnetic powder include powders of ferromagnetic metals such as iron, cobalt and nickel; powders of magnetic oxides such as magnetite, hematite and ferrite; and powders of alloys of iron, cobalt and nickel. The content of the magnetic powder is preferably 15 to 70% by mass with respect to the toner mass.

  Waxes can be incorporated into the toner for the purpose of improving releasability during fixing and improving fixing properties. Examples of the wax include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer Tropus wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof. Examples of the derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products. In addition, as waxes, long-chain alkyl alcohol, fatty acid having a long-chain alkyl group, acid amide having a long-chain alkyl group, ester having a long-chain alkyl group, ketone having a long-chain alkyl group, hydrogenated castor oil and derivatives thereof Plant waxes, animal waxes, mineral waxes and petrolactams.

  If necessary, the toner may contain a charge control agent. Charge control agents include negative charge control agents and positive charge control agents. For example, an organic metal complex or a chelate compound can be used to control the toner to be negatively charged. Examples thereof include monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Others include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives of bisphenol. Further, as a substance for positively charging the toner, nigrosine, a modified product of nigrosine modified with a fatty acid metal salt; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Quaternary ammonium salts; phosphonium salts such as tributylbenzylphosphonium-1-hydroxy-4-naphthosulfonate, tetrabutylphosphonium tetrafluoroborate; these lake pigments (the rake agents include phosphotungstic acid, phosphomolybdic acid Phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) higher fatty acid metal salts; guanidine compounds and imidazole compounds.

  If necessary, the toner is used by externally adding a powder such as an inorganic fine powder for the purpose of improving fluidity. Examples of such fine powder include inorganic fine powder. As the inorganic fine powder, silica fine powder; fine powder of metal oxide such as alumina, titania, germanium oxide and zirconium oxide; fine powder of carbide such as silicon carbide and titanium carbide; nitride such as silicon nitride and germanium nitride Fine powder. These fine powders may be organically treated with an organosilicon compound or a titanium coupling agent. Examples of organosilicon compounds include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, and bromomethyldimethyl. Chlorsilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyl Diethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3 -Diphenyltetramethyldisiloxane and dimethylpolysiloxanes having 2 to 12 siloxane units per molecule and containing hydroxyl groups bound to one Si each in the terminal unit. Moreover, you may use what processed the untreated fine powder with the nitrogen-containing silane coupling agent. In particular, in the case of a positive toner, a toner treated with a nitrogen-containing silane coupling agent is preferable. Nitrogen-containing silane coupling agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, Monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethylaminophenyltrimethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ -Propylbenzylamine, trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine Emissions include trimethoxysilyl -γ- propyl imidazole.

  Methods for treating inorganic fine powder with the silane coupling agent include 1) spray method, 2) organic solvent method, and 3) aqueous solution method. In general, the treatment by the spray method is a method in which the inorganic fine powder is stirred and sprayed with an aqueous solution or solvent solution of the coupling agent, and then the water or solvent is removed and dried at about 120 to 130 ° C. The treatment by the organic solvent method is a method in which a coupling agent is dissolved in an organic solvent (alcohol, benzene, halogenated hydrocarbon, etc.) containing a hydrolysis catalyst together with a small amount of water, and an inorganic fine powder is immersed therein. Then, it is a method of performing solid-liquid separation by filtration or pressing and drying at about 120 to 130 ° C. In the aqueous solution method, a coupling agent of about 0.5% is hydrolyzed in water or a water-solvent having a constant pH, and the inorganic fine powder is immersed therein, followed by solid-liquid separation in the same manner and drying. Is.

It is also possible to use fine powder treated with silicone oil as another organic treatment. As a preferable silicone oil, one having a viscosity at 25 ° C. of 0.5 to 10000 mm ² / s, preferably 1 to 1000 mm ² / s is used. Examples thereof include methyl hydrogen silicone oil, dimethyl silicone oil, phenylmethyl silicone oil, chlorophenyl methyl silicone oil, alkyl-modified silicone oil, fatty acid-modified silicone oil, polyoxyalkylene-modified silicone oil, and fluorine-modified silicone oil. Moreover, you may use the silicone oil which has a nitrogen atom in a side chain. Particularly in the case of a positive toner, it is preferable to use a silicone oil having a nitrogen atom in the side chain. In the treatment with silicone oil, the inorganic fine powder is vigorously disturbed while being heated and sprayed or vaporized with the silicone oil or a solution thereof, or the inorganic fine powder is made into a slurry and stirred. It is carried out by dropping silicone oil or a solution thereof. These silicone oils are used singly or as a mixture of two or more or in combination or multiple treatments. Moreover, you may use together with the process by a silane coupling agent.

  Toner particles are preferably used after being subjected to spheroidizing treatment and surface smoothing treatment by various methods, since transferability is good. As such a method, in a device having a stirring blade or blade and a liner or casing, when the toner particles are passed through a minute gap between the blade and the liner, the surface of the toner particles is smoothed by a mechanical force. And a method of spheroidizing toner particles; a method of suspending toner in warm water to spheroidize; and a method of spheroidizing by exposing the toner to a hot air stream. Alternatively, spherical toner particles can be directly produced by suspending a mixture containing a monomer as a binder resin for toner particles in an aqueous medium and polymerizing the monomers to prepare toner particles. The method of doing is mentioned. As a general method, a polymerizable monomer, a colorant, a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, a release agent, and other additives are uniformly dissolved or dispersed in a single amount. After preparing the body composition, the monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer to an appropriate particle size using an appropriate stirrer, and further subjected to a polymerization reaction to obtain a desired particle size. This is a method for obtaining toner particles having the following.

  The toner can be mixed with a carrier and used as a two-component developer.

  Carriers include hematite, magnetite, manganese-zinc ferrite, nickel-zinc ferrite, manganese-magnesium ferrite, lithium ferrite, copper-zinc ferrite particles, and mixtures thereof, magnetic Resin powder containing a body is mentioned. A carrier having an average particle diameter of 20 to 200 μm, preferably 20 to 80 μm is used.

  Such a carrier may use the above-mentioned granular materials directly as carrier particles, but in order to adjust the triboelectric charge of the toner or prevent toner spent on the carrier, silicone resin, fluororesin, The surface of the particles can be appropriately coated with a coating agent such as an acrylic resin or a phenol resin.

  The physical property measuring method according to the present invention will be described below.

Measuring method (1) Graphitization degree of graphitized particles p (002)
The degree of graphitization p (002) is determined by measuring the lattice spacing d (002) obtained from the X-ray diffraction spectrum of graphite using, for example, a powerful fully automatic X-ray diffractometer “MXP18” system manufactured by Mac Science.
d (002) = 3.440−0.086 [1-p (002) ² ]
Ask for.

The lattice spacing d (002) uses CuKα as an X-ray source, and CuKβ rays are removed by a nickel filter. High-purity silicon is used as the standard material, and the lattice spacing d (002) is calculated from the peak positions of the C (002) and Si (111) diffraction patterns. The main measurement conditions are as follows.
X-ray generator: 18 kW
Goniometer: Horizontal goniometer Monochromator: Working tube voltage: 30.0kV
Tube current: 10.0 mA
Measurement method: Continuous method Scan axis: 2θ / θ
Sampling interval: 0.020 deg
Scan speed: 6.000 deg / min
Divergence slit: 0.50deg
Scattering slit: 0.50deg
Receiving slit: 0.30mm

(2) Surface roughness measurement of resin coating layer surface The arithmetic average roughness Ra of the resin coating layer surface is measured based on the surface roughness of JIS-B0601, for example, using a surf coder SE-3500 manufactured by Kosaka Laboratory. taking measurement. As measurement conditions, measurement was performed for 3 points in the axial direction × 3 points in the circumferential direction = 9 points at a cutoff of 0.8 mm, an evaluation length of 4 mm, and a feed rate of 0.5 mm / s, and an average value thereof was taken.

(3) Measurement of hardness of resin coating layer surface The hardness of the resin coating layer surface is a hardness value obtained from a surface film physical property test using, for example, a Fisherscope H100V manufactured by Fischer Instruments. In the measurement, a diamond indenter with a square pyramid with a facing angle of 136 ° was used, and when the measurement load was stepped into the film, the indentation depth with the load applied was electrically measured. The hardness value is displayed as a ratio obtained by dividing the test load by the surface area of the indentation generated by the test load, and the universal hardness value HU is expressed by the following formula (1). It is represented by the hardness value at the maximum indentation depth.
Universal hardness value HU = K × F / h2 [N / mm2] (1)
[Wherein K represents a constant (1 / 26.43), F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter]

  The hardness value is preferably used because it can be measured with a smaller load than other hardness measurements, and a material having elasticity and plasticity can obtain hardness including elastic deformation and plastic deformation.

  The sample prepared for the hardness measurement is a sample with a resin coating layer formed on the surface of the substrate, but the measurement accuracy is improved when the surface of the resin coating layer is smooth. More preferably, the measurement is performed after the treatment. In the present invention, the surface of the resin coating layer is subjected to a polishing process using a # 2000 polishing tape, and the surface roughness Ra after the polishing process is set to 0.2 or less.

The test load and the maximum indentation depth of the indenter are preferably in a range that is not affected by the surface roughness of the surface of the resin coating layer and that is not affected by the underlying substrate. A test load is applied so that the indentation depth is 1 to 2 μm. The measurement environment is a temperature of 23 ° C. and a humidity of 50% RH, the number of measurements is 100 at different measurement points, the average value obtained from the hardness distribution is A, and the standard deviation is σ.
(4) Measurement of volume resistance value of resin coating layer A conductive resin coating layer is formed on a PET sheet having a thickness of 100 μm with a thickness of 7 to 20 μm. For example, resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka Co., Ltd.) ) To measure the volume resistance value using a four-terminal probe. The measurement environment is a temperature of 20 to 25 ° C. and a humidity of 50 to 60% RH.
(5) Particle size measurement of conductive material The particle size of a conductive material such as graphitized particles is measured using a Coulter LS-230 type particle size distribution meter (manufactured by Coulter, Inc.) of a laser diffraction type particle size distribution meter. As a measuring method, an aqueous module is used, and pure water is used as a measuring solvent. The measurement system of the particle size distribution analyzer is washed with pure water for about 5 minutes, and 10 to 25 mg of sodium sulfite is added to the measurement system as an antifoaming agent to execute the background function.

Next, 3 to 4 drops of a surfactant is added to 10 ml of pure water, and 5 to 25 mg of a measurement sample is further added. The aqueous solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes to obtain a sample solution. The sample solution is gradually added into the measurement system of the measurement device, and the PIDS on the screen of the device is Measurement is performed by adjusting the sample concentration in the measurement system to be 45 to 55%, and the volume average particle diameter calculated from the volume distribution is obtained.
(6) Measurement of true density of unevenness-forming particles The true density of unevenness-forming particles is measured using, for example, a dry density meter Accupic 1330 (manufactured by Shimadzu Corporation).
(7) Measurement of volume resistance value of irregularity forming particles A sample is put in an aluminum ring having a diameter of 40 mm, and is pressure-formed at 2500 N. For example, a four-terminal probe using a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka) Is used to measure the volume resistance value. The measurement environment is a temperature of 20 to 25 ° C. and a humidity of 50 to 60% RH.
(8) Measurement of scraping amount of resin coating layer For example, the outer diameter before and after durability is measured with a laser length measuring device (manufactured by KEYENCE: controller LS-5500, sensor head LS5040T). From the measured values before and after that, the average value of 60 points is taken as the scraping amount (μm).
(9) Particle size measurement of toner and resin particles 0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added to 100 to 150 ml of the electrolyte solution, and 2 to 20 mg of a measurement sample is added thereto. The electrolytic solution in which the sample is suspended is dispersed for 1 to 3 minutes using an ultrasonic disperser, and 0.3 to 40 μm on the basis of volume using an aperture adjusted to a toner size such as 17 μm or 100 μm by a Coulter counter multisizer. The particle size distribution is measured. From the data measured under these conditions, the number average particle diameter and the weight average particle diameter are obtained by computer processing. Further, the cumulative ratio of the number average particle diameter below the 1/2 double cumulative distribution is calculated from the number-based particle size distribution to obtain the cumulative value below the 1/2 double cumulative distribution. Similarly, a cumulative ratio equal to or greater than the double diameter cumulative distribution of the weight average particle diameter is calculated from the volume-based particle size distribution, and a cumulative value equal to or greater than the double diameter cumulative distribution is obtained.

  Hereinafter, the present invention will be described in more detail with specific examples. “Part” represents “part by mass” and “%” represents “% by mass”.

(Graphitized particle production example 1)
Graphitized particles used for the resin coating layer formed on the surface of the developing sleeve were prepared. As a graphitized particle, β-resin is extracted from coal tar pitch by solvent fractionation, hydrogenated β-resin and subjected to heavy treatment, and then solvent-soluble content is removed with toluene to remove mesophase pitch. A bulk was obtained. Volume obtained by finely pulverizing bulk mesophase pitch, oxidizing the mesophase pitch particles in air at about 300 ° C., firing at 3000 ° C. in a nitrogen atmosphere, graphitizing, and further classifying Graphitized particles having an average particle size of 2.4 μm were designated as a-1. Table 1 shows the physical properties of the graphitized particles a-1.

(Graphitized particle production examples 2 to 5)
Graphitized particles a-2 to a-5 having volume average particle diameters shown in Table 1 were produced in the same manner as in Graphitized Particle Production Example 1 except that the firing temperature and classification conditions were changed. Table 1 shows the physical properties of the obtained graphitized particles a-2 to a-5.

(Graphitized particle production example 6)
As graphitized particles, mesocarbon microbeads obtained by heat-treating coal-based heavy oil are washed and dried, then mechanically dispersed with an atomizer mill, and subjected to primary heat treatment at 1200 ° C. in a nitrogen atmosphere. Carbonized. Subsequently, the carbonized beads were subjected to secondary dispersion with an atomizer mill, then heat-treated at 2800 ° C. in a nitrogen atmosphere, and further classified to obtain a graphitized particle having a volume average particle diameter of 2.6 μm as a-6. It was. Table 1 shows the physical properties of the graphitized particles a-6.

(Graphitized particle production examples 7 to 8)
Graphitized particles a-7 to 8 having a volume average particle diameter shown in Table 1 were produced in the same manner as in Graphitized Particle Production Example 6 except that the firing temperature and classification conditions were changed. Table 1 shows the physical properties of the graphitized particles a-7 to 8 obtained.

(Graphitized particle production examples 9 to 10)
Graphitized particles a-9 and a-10 having volume average particle diameters of 2.5 μm and 4.0 μm are produced by graphitizing by calcining coke and tar pitch at 2800 ° C. as the graphitized particles, and further classifying them. did. Table 1 shows the physical properties of the graphitized particles a-9 to 10 obtained.

(Graphitized particle production examples 11-12)
As graphitized particles, spherical phenol resin particles having a volume average particle size of 3.0 μm and spherical phenol resin particles having a volume average particle size of 4.5 μm are graphitized by firing at 2200 ° C. in a nitrogen atmosphere, and further classified to obtain a volume average particle. Graphitized particles a-11 having a diameter of 2.3 μm and graphitized particles a-12 having a diameter of 3.8 μm were prepared. Table 1 shows the physical properties of the graphitized particles a-11 to 12 obtained.

(Irregularity forming particle production example 1)
Concavity and convexity formation particles used for the resin coating layer formed on the surface of the developing sleeve were prepared. As the irregularity forming particles, a coal-based bulk mesophase pitch powder having a number average particle diameter of 1.0 μm or less using a raikai machine (automatic mortar, manufactured by Ishikawa Factory) on 100 parts by weight of a spherical phenol resin having a volume average particle diameter of 3.0 μm. 14 parts by weight were uniformly coated, thermally stabilized in an oxidizing atmosphere, and then fired at 2,000 ° C. to produce conductive spherical carbon particles. The spherical carbon particles were designated as unevenness forming particles e-1. Table 2 shows the physical properties of the unevenness-forming particles e-1.

(Concavity and convexity formation particle production example 2)
Spherical carbon particles were produced in the same manner as in the irregularity-forming particle production example 1 except that a spherical phenol resin having a volume average particle size of 4.0 μm was used, and spherical carbon particles having a volume average particle size of 3.8 μm were obtained. The obtained spherical carbon particles were designated as unevenness forming particles e-2. Table 2 shows the physical properties of the unevenness-forming particles e-2.

(Concavity and convexity formation particle production example 3)
As the unevenness forming particles, 100 parts by weight of polymethyl methacrylate resin (PMMA resin) and 25 parts by weight of carbon black are melt-mixed, kneaded, pulverized, and classified to contain carbon black having a volume average particle diameter of 3.1 μm. Spherical carbon black-dispersed PMMA resin particles having a volume average particle diameter of 2.3 μm were prepared by performing spheronization using a hybridizer (manufactured by Nara Machinery) after obtaining the PMMA resin particles. Spherical carbon black-dispersed PMMA resin particles were used as the unevenness forming particles e-3. Table 2 shows the physical properties of the unevenness forming particle e-3.

(Concavity and convexity formation particle production example 4)
Carbon black-dispersed PMMA resin particles having a volume average particle size of 4.6 μm were prepared in the same manner as in the irregularity-forming particle production example 3, and then spherical carbon having a volume-average particle size of 3.9 μm in the same manner as the irregularity-forming particle production example 3. Black dispersed PMMA resin particles were obtained. The obtained spherical carbon black-dispersed PMMA resin particles were designated as unevenness forming particles e-4. Table 2 shows the physical properties of the unevenness-forming particles e-4.

(Development sleeve production example 1)
A paint for applying a resin coating layer on the surface of the developing sleeve was prepared.
Resol type phenol resin solution (50% methanol solution): 200 parts Graphitized particles a-1: 45 parts Conductive carbon black: 5 parts Isopropyl alcohol: 220 parts The above materials were dispersed using a sand mill. Dilute the phenolic resin solution with a portion of isopropyl alcohol. Graphitized particles a-1 and conductive carbon black were added thereto, and sand mill dispersion was performed using glass beads having a diameter of 1 mm as media. The remaining phenol resin solution and isopropyl alcohol were added to obtain a paint having a solid content of about 32%. After spraying this paint to form a resin coating layer of about 12 μm on the surface of an aluminum cylindrical substrate having an outer diameter of 24.5 mm, this was dried and cured at 150 ° C. for 30 minutes in a hot air dryer. Then, a magnet roller and a flange were attached to obtain a developing sleeve B-1. Table 3 shows the structure and physical properties of the obtained resin coating layer.

(Development sleeve production examples 2 to 21)
Developing sleeves B-2 to 13 and C-1 to 8 were produced in the same manner as in developing sleeve production example 1, except that the paint was produced with the materials and mixing ratios shown in Table 3. For the developing sleeves B-9 to 13 and C-5 to 8, a base having an outer diameter of 20.0 mm was used as the aluminum cylindrical base. Table 3 shows the structure and physical properties of the obtained resin coating layer. For the developing sleeves B-2, B-4, B-8, and B-10, the following compounds 1 and 2 were used as charge control agents.

(Toner Production Example 1)
An insulating negatively chargeable magnetic toner as a one-component developer was prepared.
・ Styrene-acrylic resin: 100 parts ・ Magnetite: 90 parts ・ Negative charge control agent (chromium complex of salicylic acid): 2 parts ・ Hydrocarbon wax: 5 parts The above materials are mixed with a Henschel mixer to produce a biaxial type Melting and kneading dispersion was performed with a ruder. After the kneaded product is cooled, it is finely pulverized by a pulverizer using a jet stream, and further classified using an air stream classifier. The number ratio of particles having a weight average particle diameter of 6.7 μm and a particle diameter of 4 μm or less is 14. Magnetic toner particles having a distribution of 0.6% and a mass ratio of particles having a particle diameter of 10.1 μm or more of 3.0% were obtained. Next, 100 parts of magnetic toner particles are externally mixed with 1.0 part of hydrophobic colloidal silica fine powder and 3.0 parts of strontium titanate fine particles using a Henschel mixer, and magnetic toner α as a one-component developer is mixed. Got.

(Toner Production Example 2)
An insulating negatively chargeable magnetic toner as a one-component developer was prepared.
・ Styrene-acrylic resin: 100 parts ・ Magnetite: 90 parts ・ Negative charge control agent (azo-based iron complex): 2 parts ・ Hydrocarbon-based wax: 5 parts Melt-kneading dispersion was performed with an extruder. After the kneaded product is cooled, it is finely pulverized by a pulverizer using a jet stream, and further classified using an air stream classifier. The number ratio of particles having a weight average particle diameter of 6.2 μm and a particle diameter of 4 μm or less is 16. Magnetic toner particles having a distribution of 0.8% and a weight ratio of particles having a particle diameter of 10.1 μm or more of 2.2% were obtained. Next, the hydrophobic colloidal silica fine powder was externally added and mixed with 100 parts by weight of the magnetic toner particles using a 1.0 part by weight Henschel mixer to obtain a magnetic toner β as a one-component developer.

(Example 1)
Using the developing sleeve B-1 and the magnetic toner α, it was incorporated into the developing device shown in FIG. The image was evaluated by applying a predetermined developing bias using a modified machine of imagerunner 6000 manufactured by Canon Co. The image was drawn at 23 ° C. and 60% RH normal temperature and humidity (N / N), 23 ° C. and 5% RH normal temperature and low humidity (N / L), and 30 ° C. and 80% RH high temperature and high humidity (H / H). H) Up to 500,000 sheets under the environment. Table 4 shows the evaluation results obtained by the following evaluation methods.

Evaluation method (1) Charge amount (Q / M) and toner transport amount (M / S) of magnetic toner on the developing sleeve
The magnetic toner carried on the developing sleeve is sucked and collected by a metal cylindrical tube and a cylindrical filter. At that time, the charge amount Q stored in the condenser through the metal cylindrical tube, the collected magnetic toner weight M, and the magnetic toner The charge amount Q / M (mC / kg) per unit weight and the weight of the magnetic toner per unit area [M / S (mg / cm ² )] are calculated from the area S where the magnetic toner is sucked, and the charge amount of the magnetic toner is calculated respectively. (Q / M) and magnetic toner transport amount (M / S).
(2) Image Density The density of a solid black image was measured with a reflection densitometer RD918 (manufactured by Macbeth), and an average value of five points was taken as the image density.
(3) Fog and reversal fog Measure the reflectance of the solid white image, and further measure the reflectance of the unused transfer paper (the worst value of the reflectance of the solid white image-the highest reflectance of the unused transfer paper. Value) was the fog density. The reflectance was measured with TC-6DS (manufactured by Tokyo Denshoku). However, when the measured value is judged visually, 1.5 or less is a level that can hardly be confirmed by visual observation, 2.0 to 3.0 is a level that can be confirmed by careful observation, and if it exceeds 4.0, fog can be clearly confirmed. Is a level.
(4) Character scattering Using a character chart with an image ratio of about 6.0%, characters on the obtained image are magnified 100 times with an optical microscope, the degree of scattering is observed, and the evaluation result is an index of A to E ranks. It showed in.
(5) Solid image streaks and unevenness Solid black images and halftone (HT) images were developed, and streaks and unevenness were visually observed in the respective images, and the evaluation results were shown by indices of A to E ranks.
(6) Toner contamination and toner fusion (contamination and fusion) to the developing sleeve surface
After evaluating the image under each environment, the developing sleeve is removed, and the adhesion degree of the toner on the sleeve is observed with a field emission-scanning microscope (FE-SEM). Indicated.

(Examples 2-8, Comparative Examples 1-4)
Images were evaluated in the same manner as in Example 1 except that the developing sleeves B-2 to 8 and C-1 to 4 were used instead of the developing sleeve B-1 used in Example 1. The evaluation results are shown in Tables 4-5.

Example 9
Using the developing sleeve B-9 and magnetic toner β, it was incorporated into the developing device shown in FIG. The image was evaluated by applying a predetermined developing bias using a modified laser beam printer LBP930EX manufactured by Canon. The images were drawn at 23 ° C. and 60% RH normal temperature and humidity (N / N), 15 ° C. and 10% RH low temperature and low humidity (L / L), and 32.5 ° C. and 85% RH high temperature and high humidity (L / L). H / H) Up to 50,000 sheets in an environment. The evaluation method was the same as in Example 1, and the obtained evaluation results are shown in Table 6.

(Examples 10-13, Comparative Examples 5-8)
The image formation was evaluated in the same manner as in Example 9 except that the developing sleeves B-10 to 13 and C-5 to 8 were used instead of the developing sleeve B-9 used in Example 9. The evaluation results are shown in Tables 6-7.

It is a schematic diagram which shows the cross section on the developer carrier used for this invention. It is a schematic diagram which shows an example of the image development apparatus used for this invention. It is a schematic diagram which shows another example of the image development apparatus used for this invention. It is a schematic diagram which shows another example of the image development apparatus used for this invention. 1 is a schematic diagram illustrating an image forming apparatus used in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Graphitized particle 2 Binder resin 3 Resin coating layer 4 Cylindrical base | substrate 5 Magnet N, N1, N2, S, S1, S2 Magnetic pole 301 Photosensitive drum (electrostatic latent image carrier)
302 Restriction member 303 Hopper (developer container)
304 Developer 305 Magnet Roller (Magnet)
306 Metal cylindrical tube (base)
307 Resin coating layer 308 Development sleeve (developer carrier)
309, 310, 314 Stirring blade 311 Screw 312 Stirring wall 313 Development bias power source (bias means)
315 Metal support 316 Elastic layer 317 Surface layer 318 Developing roller 319 Developer supply-peeling member 101 Photosensitive drum (electrostatic latent image carrier)
103 Hopper (developer container)
104 one-component developer 105 multipolar permanent magnet 108 developing sleeve 109 bias applying means 111 regulating member 113 contact transfer means 114 charge applying means 115 exposure 116 erase exposure 117 fixing means 118 cleaning means 118a cleaning blade 119 contact charging means 120
D Development area P Recording material

Claims (8)

In the developer carrier used in the developing device that develops the electrostatic latent image formed on the electrostatic latent image carrier with the developer carried on the developer carrier and visualizes it,
The developer carrier has a resin coating layer on at least the substrate and the substrate surface,
The resin coating layer contains at least a binder resin, and graphitized particles having a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95,
The surface of the resin coating layer has the following formula (1)
Universal hardness value HU = K × F / h ² [N / mm ² ] (1)
[Wherein, K represents a constant, F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter. ]
The average value A and the standard deviation σ determined from the hardness distribution of the measured value HU of the universal hardness in the surface film physical property test calculated in
100 ≦ A ≦ 800 [N / mm ² ],
σ <30 [N / mm ² ]
A developer carrying member characterized by the above.   The developer carrying member according to claim 1, wherein the surface of the resin coating layer has an arithmetic average roughness Ra of 0.20 to 0.70 μm according to JIS-B0601.   The developer carrying member according to claim 1, wherein the resin coating layer further contains a charge control agent for adjusting the charge of the developer.   The developer-carrying member according to any one of claims 1 to 3, wherein the graphitized particles contain at least one obtained by graphitizing bulk mesophase pitch particles.   5. The developer carrying member according to claim 1, wherein the graphitized particles contain at least one obtained by graphitizing mesocarbon microbead particles.   The developer-carrying member according to claim 1, wherein the graphitized particles have a volume average particle diameter of 0.5 to 4.0 μm. A developer container, a developer carrier for carrying and transporting the developer contained in the developer container, and a developer carrier on the developer carrier disposed in proximity to or in pressure contact with the developer carrier; A developer layer thickness regulating member for forming a thin layer is provided, and the developer carrying member carries and conveys the developer to a developing area facing the electrostatic latent image carrying member, and the electrostatic latent image carrying In the developing device for developing the electrostatic latent image formed on the body with a developer to form a toner image,
The developer carrier has a resin coating layer on at least the substrate and the substrate surface,
The resin coating layer contains at least a binder resin, and graphitized particles having a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0.95,
The surface of the resin coating layer has the following formula (1)
Universal hardness value HU = K × F / h ² [N / mm ² ] (1)
[Wherein, K represents a constant, F represents the test load (N), and h represents the maximum indentation depth (mm) of the indenter. ]
The average value A and the standard deviation σ determined from the hardness distribution of the measured value HU of the universal hardness in the surface film physical property test calculated in
100 ≦ A ≦ 800 [N / mm ² ],
σ <30 [N / mm ² ]
A developing device characterized by the above.   The developing device according to claim 7, wherein the developer carrying member is the developer carrying member according to claim 2.

Images