JP2005077870A - Developer carrier and developing method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing method using a developer carrier which does not cause problems, such as density degradation, sleeve ghost, sleeve fusion, blotch, and fogging, even under different environments, and can stably obtain a high grade image having high image density without density unevenness. <P>SOLUTION: The developer carrier, which caries a one-component developer for visualizing the electrostatic latent image carried on an electrostatic latent image carrier, has at least a substrate 5 and a resin coating layer 6 formed on the substrate surface. The resin coating layer 6 contains at least a resin 6 and graphitized particles (a). The graphitized particles are 0.20≤p(002)≤0.95 in the degree of graphitization p (002) and the initial wear height Rpk on the surface of the resin coating layer is 0.2 to 1.0 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a developer carrier and an electron used for developing and developing a latent image formed on an image carrier such as an electrophotographic photosensitive member or an electrostatic recording dielectric in electrophotography. The present invention relates to a photographic development method.

  Conventionally, a number of methods are known as electrophotographic methods. Generally, a photoconductive material is used to form an electric latent image on an electrostatic latent image holding member (photosensitive drum) by various means. Then, the electrostatic latent image is developed with a developer (toner) to be visualized, and if necessary, the toner image is transferred to a transfer material such as paper, and then applied onto the transfer material by heat, pressure, or the like. A toner image is fixed to obtain a copy.

  Although image formation by these electrophotographic methods has reached a satisfactory level for document copying, it will continue to be used for output images of full-color images required by the development of computers and the spread of high-resolution digital cameras. Further improvement in image quality and quality is desired.

  Development methods in electrophotography are mainly divided into a one-component development method and a two-component development method.

  Conventionally, two-component developers have been used to output these full-color images. In this developing method, the carrier imparts electric charge to the toner by triboelectric charging, and carries the toner on its surface by electrostatic attraction due to this electric charge. The developer having toner and carrier is coated on the developing sleeve containing the magnet to a predetermined layer thickness by a developer layer thickness regulating member, and the electrostatic latent image is obtained by utilizing the magnetic force and the frictional resistance of the developing sleeve surface. It is conveyed and developed in a development area formed between a carrier (photosensitive member) and a developing sleeve. However, in recent years, a developing device using a one-component developing system is often used for the purpose of reducing the weight and size of the electrophotographic apparatus.

  The one-component development method does not require carrier particles such as glass beads or iron powder unlike the two-component development method, and therefore the development device itself can be reduced in size and weight. Furthermore, since the two-component development method needs to keep the toner concentration in the developer constant, an apparatus that detects the toner concentration and replenishes the necessary amount of toner is required. Therefore, the developing device is also large and heavy here. In the one-component development system, such an apparatus is not necessary, so it is preferable because it can be made small and light.

  In the one-component development system, a non-magnetic toner containing no magnetic material and a magnetic toner containing a magnetic material may be used in the toner, but when using for a full color image, the magnetic material is included from the viewpoint of color reproducibility. Non-magnetic single component developers are often used.

  As a developing device using a one-component developing system, an electrostatic latent image is formed on the surface of a photosensitive drum as a developing electrostatic latent image holding member, and friction between a developer carrying member (developing sleeve) and toner, and / or The toner is positively or negatively charged by friction with the developer layer thickness regulating member for regulating the toner coat amount on the developing sleeve, and the toner is applied thinly on the developing sleeve, and the photosensitive drum and the developing sleeve Are transported to a developing area facing each other, and in the developing area, toner is developed by flying and adhering to the electrostatic latent image on the surface of the photosensitive drum to develop the electrostatic latent image as a toner image.

  Recently, in order to digitize electrophotographic devices and further increase image quality, the toner has been reduced in particle size and particle size, and in order to reduce waste toner for the purpose of further reducing the weight and size of the device. In addition, the toner transfer efficiency is improved. Further, for the purpose of shortening the first copy time and power saving, the toner fixing temperature tends to be lowered by increasing the ratio of the low softening point substance in the toner.

  It tends to be difficult only by the conventional pulverization method such as the above-mentioned reduction in toner particle size and particle size, improvement in transfer efficiency, and achievement of low-temperature fixing.

  The polymerization method used for toner production is a monomer composition in which a polymerizable monomer, a colorant, a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed. Then, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, such as an aqueous phase, using a suitable stirrer, and simultaneously subjected to a polymerization reaction, whereby a toner having a desired particle size is obtained. Is the way to get.

  Since this manufacturing method does not go through a pulverization step, it is not necessary to impart brittleness to the developer, and further, a material that can use a large amount of a low softening point material that could not be used in the conventional pulverization method. The selection range is widened and preferable.

  Furthermore, the polymerization method has characteristics that the particle size distribution is relatively easy and the toner having a spherical shape and high transfer efficiency can be produced relatively easily.

  However, even in the case of using the toner by the polymerization method having the above characteristics, the formation of the toner layer on the developer carrying member depends on the environmental state, the physical properties of the toner, the state of the surface of the developer carrying member, and the like. . In particular, under low temperature and low humidity, the amount of charge per unit mass increases, so that it is more likely to adhere electrostatically on the developing sleeve. Under high temperature and high humidity, the toner may be exposed to physical force from the outside. Since a material that is easily fluidized is used, the material is easily changed in quality, and the toner is easily contaminated with the sleeve and fused with the sleeve.

  Further, as the copying is repeated, the toner is repeatedly rubbed against the developer carrier, so that additives for improving the fluidity of the toner are released from the toner, and these free substances are deposited on the developer carrier. Alternatively, since the low softening point substance in the toner forms a film on the developer carrying member, there is a problem that the surface state of the developer carrying member changes and the developability of the toner changes.

  Further, when the toner obtained by the polymerization method is used in such a developing device, the toner obtained by the polymerization method has extremely good fluidity compared to the toner obtained by the pulverization method, and therefore, the toner is separated from the developer carrier. There may be a case where a phenomenon of slipping between the regulating members is likely to occur. For this reason, the charge amount between the developer particles is likely to be non-uniform, and the toner is likely to be in a non-uniform coating state on the developer carrying member, and as a result, a defective image with background fog and image unevenness is likely to occur. Become. Further, toner is likely to enter the bearing or the like during repeated endurance image formation, and a toner fusion product is likely to be generated thereby, so that transfer defects are likely to occur during transfer.

  In general, a toner using polymerization is substantially spherical, so that it is easy to close-pack in the developing device, and the developer is densely packed in the downstream portion of the regulating member in the developing device. In some cases, so-called sleeve contamination occurs in which the toner is fused on the developer carrying member due to an increase in the mechanical load force. Sleeve contamination is undesirable because it causes a reduction in image density and fogging.

  When the polymerization method is used, it is difficult to adjust the charge of the toner, and various devices have been devised by external additives, but it is related to durability stability such as non-uniformity of toner charge and occurrence of fusion to the sleeve surface. The problem is not fully resolved.

  Furthermore, as the developing sleeve rotates repeatedly, the charge amount of the toner coated on the developing sleeve becomes too high due to contact with the developing sleeve, and the toner attracts by the mirroring force with the surface of the developing sleeve. A so-called charge-up phenomenon that becomes stationary on the surface of the developing sleeve and does not move from the developing sleeve to the latent image on the electrostatic latent image holding member (drum) is likely to occur particularly under low humidity. When such a charge-up phenomenon occurs, the toner in the upper layer is difficult to be charged, and the development amount of the toner is reduced, which causes problems such as thin line images and thin image density of solid images. In addition, the toner that is not properly charged due to charge-up becomes poorly regulated and flows out onto the sleeve, causing a so-called blotch phenomenon that becomes spotted and uneven on the wave. Furthermore, since the toner layer formation state of the image portion (toner consumption portion) and the non-image portion is changed and the charging state is different, for example, the position where the solid image having a high image density is once developed is next to the developing sleeve. When a halftone image is developed when the developing position is reached during rotation, a phenomenon that a solid image appears on the image, that is, a so-called sleeve ghost phenomenon is likely to occur.

  As a method for solving such a phenomenon, in Patent Document 1, Patent Document 2, and the like, a coating layer in which conductive fine powder such as crystalline graphite and carbon is dispersed in a resin is provided on a substrate. A method using a developing sleeve has been proposed.

  Although this method is effective for preventing the charge-up phenomenon and improving the uniformity of charging, it is still insufficient, and when a large amount of the above powder is added, charge-up and sleeve ghost are not affected. However, in particular, when a non-magnetic one-component developer is used, the ability to impart charge to the toner becomes insufficient, and transportability and density unevenness tend to occur. Further, when a large amount of the above powder is added, the coating layer becomes brittle and becomes easy to be scraped, and the surface becomes non-uniform, resulting in a detrimental effect on the durability of the sleeve. In addition, when a coating layer in which the crystalline graphite is dispersed is used, the coating layer surface has lubricity due to the scaly structure of the crystalline graphite. Although the improvement is observed, since the shape is scaly, the state of the surface of the coating layer becomes non-uniform and the initial wear height becomes a large value. When the regulating force such as the contact pressure by the regulating member is strengthened to regulate the toner layer on the developer carrying member, if the initial wear height is large, the regulating member is likely to be scratched, and toner fusing and streaks may occur. Likely to happen. Furthermore, since the hardness of the crystalline graphite is low, the crystalline graphite itself is likely to be worn and detached on the surface of the coating layer, and the surface roughness and surface composition of the coating layer change when the durability is advanced, and the toner Inadequate transport and non-uniform charging of toner.

  In Patent Document 3, Patent Document 4, and the like, the toner is manufactured by a spheroidizing toner or a polymerization method by adding a quaternary ammonium salt compound that is positively charged to iron powder into the resin. Prior art using a developing sleeve that prevents excessive charging such as charge-up for a negative toner has been proposed.

  Although this method is effective for preventing the charge-up phenomenon and improving the uniformity of charging, the charging stability and the conveyance stability for the toner are still insufficient.

  In particular, when using a non-magnetic one-component toner that does not have a magnetic material produced by a polymerization method and uses a non-contact type developing device that performs development in a non-contact state between a photosensitive drum and a developer carrier as described below, The charging stability and the conveyance stability for a non-magnetic toner having no magnetic material as used in the present invention have not been sufficiently solved.

Japanese Patent Laid-Open No. 02-105181 Japanese Unexamined Patent Publication No. 03-036570 JP 2003-057951 A JP 2002-311636 A

  The object of the present invention is that no problems such as density reduction, sleeve ghost, sleeve fusion, blotch and fog occur even under different environmental conditions, there is no density unevenness, and high quality images with high image density are stable. The developer carrying body which can be obtained in this way and a developing method using the developer carrying body are provided.

  An object of the present invention is to provide a developer carrier capable of controlling the charging of a toner through durability and stably forming and transporting a toner layer on a sleeve even when a non-magnetic one-component spherical toner is used. It is to provide a developing method using a developer carrier.

  An object of the present invention is to reduce toner adhesion to the surface of a developer carrying member through durability even when a non-magnetic one-component spherical toner is used. It is an object of the present invention to provide a developer carrying member capable of giving a sufficient charge and a developing method using the developer carrying member.

  An object of the present invention is to use a developer carrying body and a developer carrying body that are less likely to cause deterioration of the resin coating layer on the surface of the developer carrying body due to repeated copying or durability, have high durability, and provide stable image quality. Development method.

  The object of the present invention is to prevent deterioration of the surface coating layer, such as partial scraping of the resin coating layer on the surface of the developer carrying member due to repeated copying or durability, and is excellent in chargeability to toner and stability in transportability. It is to provide a developer carrying body and a developing method using the developer carrying body.

  An object of the present invention is to provide a developer carrying body that is less likely to cause scratches and fusion to a regulating member, is less likely to cause streak-like image defects, and has a stable image quality, and a developing method using the developer carrying body. It is to be.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have configured the resin coating layer on the surface of the developer carrier to have graphitized particles having a graphitization degree in a specific range dispersed in the resin. In addition, by setting the initial wear height Rpk of the resin coating layer surface to 0.2 to 1.0 μm, the toner transportability and the charge imparting property to the toner are stabilized, and toner contamination and toner charge up occur. The present inventors have found that there is an effect of imparting an appropriate charge amount quickly and uniformly. In addition, since the resin coating layer surface has the above-described configuration, irregular irregularities can be reduced, resulting in generation of streak-like image defects that are less likely to cause rubbing scratches and toner fusion to a regulating member (blade, etc.). We found an effect that it is difficult to obtain a stable image quality.

  These effects are more effective when a non-magnetic one-component developer having no magnetic holding force on the sleeve is used. Furthermore, it is difficult to control the charge, and since the fluidity is high, a further effect can be obtained when a spherical toner is used due to a stable regulation and a polymerization method that is difficult to stably convey.

  In order to make the initial wear height Rpk on the surface of the resin coating layer within the above range, it can be controlled by the dispersion condition and coating condition of the coating liquid used to form the coating layer, but the volume distribution is sharp in the particle size distribution of the particles. It is preferable to use graphitized particles.

  The following effects can be further obtained by using graphitized particles having a specific degree of graphitization and a sharp volume distribution in the particle size distribution. In other words, a resin coating layer having a surface shape and lubricity, which is excellent in stability of transporting toner and providing stable charge, is formed, and the graphitized particles are less likely to be worn or detached from the surface of the resin coating layer. Since the developer carrier is obtained, and the hardness of the graphitized particles is close to the hardness of the resin, even if the resin coating layer is worn, it is evenly scraped, and the graphitized particles are exposed again from the resin coating layer. The change is small. For this reason, even when a large number of images are printed, it is possible to suppress the roughness of the surface coating layer of the developer carrier, the uniformity of the surface shape, and the change in the material composition of the surface, and a stable image can be obtained.

That is, the object of the present invention is achieved by the following.
(1) A developer carrying member carrying a one-component developer for visualizing an electrostatic latent image carried on an electrostatic latent image carrying member, the developer carrying member comprising at least a substrate and the substrate A resin coating layer formed on the surface, wherein the resin coating layer contains at least a resin and graphitized particles, and the graphitized particles have a graphitization degree p (002) of 0.20 ≦ p (002). ≦ 0.95, and the initial wear height Rpk of the resin coating layer surface is 0.2 to 1.0 μm.
(2) The developer carrying member according to (1), wherein the graphitized particles are obtained by graphitizing mesocarbon microbead particles.
(3) The developer carrying member according to (1), wherein the graphitized particles are obtained by graphitizing bulk mesophase pitch particles.
(4) The developer carrying member according to any one of (1) to (3), wherein the resin coating layer contains at least a quaternary ammonium salt compound that is positively charged with respect to iron powder.
(5) The resin coating layer contains at least a phenol resin, and the phenol resin is a phenol resin produced using a nitrogen-containing compound as a catalyst, and the structure includes —NH ₂ groups and ═NH groups. (4) The developer carrying member according to (4), which is a phenol resin having any of —NH— bonds.
(6) A developer container that contains a one-component developer, and a developer carrier that carries the developer contained in the developer container in layers, and development that faces the electrostatic latent image carrier In the developing method for transporting the carried developer to an area and developing and visualizing the electrostatic latent image carried on the electrostatic latent image carrier by the carried developer,
The developer carrier has at least a substrate and a resin coating layer formed on the surface of the substrate, the resin coating layer contains at least a resin and graphitized particles, and the graphitized particles have a graphitization degree. p (002) is 0.20 ≦ p (002) ≦ 0.95, and initial wear height Rpk of the resin coating layer surface is 0.2 to 1.0 μm. .
(7) The developing method according to (6), wherein the graphitized particles are obtained by graphitizing mesocarbon microbead particles.
(8) The developing method according to (6), wherein the graphitized particles are obtained by graphitizing bulk mesophase pitch particles.
(9) The developer carrying member has at least a substrate and a resin coating layer, and the resin coating layer contains at least a quaternary ammonium salt compound that is positively charged with respect to iron powder. (6) to (8).
(9) The resin coating layer contains at least a phenol resin, and the phenol resin is a phenol resin produced using a nitrogen-containing compound as a catalyst, and the structure includes —NH ₂ groups and ═NH groups. Or the development method according to (8), which is a phenol resin having either an —NH— bond.
(10) The developer is a non-magnetic one-component developer, and the non-magnetic one-component developer has an average circularity of 0.970 or more obtained from the following formulas (1) and (2). The developing method of (6) to (9).

Circularity a = L0 / L (1)
[In the formula, L0 represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. ]

［式中、ａ_aveは平均円形度であり、粒度分布の分割点Ｉでの円形度（中心値）をａ_I、頻度をｆａ_iとする。］

[ _Where a _ave is the average circularity, the circularity (center value) at the dividing point I of the particle size distribution is a _I , and the frequency is fa _i . ]

  According to the developer carrying member of the present invention and the developing device using the same, the toner is excellent in charge imparting property and wear resistance, and the toner charging uniformity and long-term durability under high temperature and high humidity and low temperature and low humidity. To provide a developer carrying member having stable toner transportability, effectively preventing blotch, toner fusion, sleeve ghosting, fogging, density reduction, etc., and obtaining a high-quality image, and a developing device using the same. it can.

  According to the present invention, the resin coating layer on the surface of the developer carrying member due to repeated copying or durability is hardly peeled off, scratched, partially scraped, etc., and the surface shape is less uniform, and the chargeability to the toner and the stability of the transportability are improved. An excellent developer carrying member and a developing method using the developer carrying member can be provided.

  Furthermore, it is possible to provide a developer carrying body that is less likely to cause scratches and fusion to the regulating member, is less likely to cause streak-like image defects, and has a stable image quality, and a developing method using the developer carrying body.

  Furthermore, even when a toner obtained by a polymerization method having extremely high fluidity is used as compared with a toner obtained by a pulverization method, a phenomenon such as the toner slipping between the developer carrying member and the regulating member may occur. It is possible to provide a developer carrying member that can prevent, achieve stable transportability, and can obtain a good image free from background fog and image unevenness, and a developing device using the same.

  According to the present invention, even when a non-magnetic one-component toner, particularly a spherical toner obtained by polymerization or the like, is used, the developer capable of satisfactorily controlling the charging of the toner through durability and stably forming the toner layer on the sleeve A carrier and a developing device using the same can be provided.

  Further, even when a non-magnetic one-component spherical toner is used according to the present invention, toner adhesion to the surface of the developer carrying member can be reduced through durability, and the toner charge can be controlled well and the toner can be sufficiently charged. Therefore, it is possible to provide a developer carrying member capable of stably forming a toner layer on a sleeve and a developing method using the same.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments. First, the developer carrier used in the one-component developing device of the present invention will be described.

  The developing device of the present invention includes a developer carrying member that carries and conveys a developer, and a developer layer thickness regulating member that regulates the thickness of the developer layer on the developer carrying member, and the layer thickness regulating member and the developer carrying member The developer layer of the one-component developer formed between the bodies is carried and conveyed to the development area facing the latent image carrier, and the latent image formed on the latent image carrier by the toner on the developer carrier. A developing device for developing and visualizing an image, wherein a developer carrier used in the image forming apparatus has at least a substrate and a resin coating layer formed on the surface of the substrate, and the resin coating layer includes at least a coating resin and Containing graphitized particles having a degree of graphitization p (002) of 0.20 ≦ p (002) ≦ 0.95 dispersed in the coating resin, and an initial wear height Rpk of the resin coating layer surface is It is 0.2 to 1.0 μm.

  By making the resin coating layer have the above surface shape, it is possible to uniformly and stably charge the toner, and it is possible to obtain a resin coating layer that is less likely to cause streaks and fusion and is less likely to be charged up. Further, by using graphitized particles having a specific degree of graphitization for the resin coating layer, good chargeability and lubricity for the toner can be obtained through durability.

The degree of graphitization p (002) is said to be the Franklin p-value. By measuring the lattice spacing d (002) obtained from the X-ray diffraction diagram of graphite, the following formula (2) is used. This is the required value.
d (002) = 3.440-0.086 (1-p (002) ² ) (2)

  This p (002) value indicates the proportion of the disordered portion of the hexagonal mesh plane stacking of carbon, and the smaller the p (002) value, the greater the degree of graphitization.

  The graphitized particles are obtained by solidifying a coke or the like described in Patent Document 1 or Patent Document 2 with tar pitch or the like, firing it at about 1000 to 1300 ° C. and then firing it at about 2500 to 3000 ° C. The raw material and the manufacturing process are different from the crystalline graphite disclosed in Patent Document 1 or the like made of artificial graphite or natural graphite. Although the degree of graphitization used in the present invention is slightly lower than that of the crystalline graphite, the graphitized particles have high conductivity and lubricity like the crystalline graphite. Further, the graphitized particles used in the present invention are different from the shape of crystalline graphite in the form of flakes or needles, and the shape of the particles is in the form of particles and the hardness of the particles themselves is relatively high. It is a feature.

  Further, the graphitized particles are different from the low specific gravity and conductive spherical particles described in Patent Document 3 in terms of the lubricity and charge imparting characteristics of the particles themselves due to the difference in raw material and manufacturing method. Low specific gravity and conductive spherical particles described in Patent Document 3 are spherical resin particle surfaces such as phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, polyacrylonitrile. In addition, a bulk mesophase pitch is coated by a mechanochemical method, and the coated particles are heat-treated in an oxidizing atmosphere and then baked in an inert atmosphere or vacuum to be carbonized and / or graphitized. Therefore, since the spherical resin particles themselves are difficult to graphitize, even if the surface is graphitized, the inside of the particles is carbonized, and the degree of graphitization p (002) of the particles themselves is large and cannot be measured. The crystallinity is different from the graphitized particles used in the present invention. Further, when the conductive spherical particles are dispersed in the resin coating layer, the toner conveying force is increased by forming a relatively large uneven shape, and the contact opportunity of the toner with the resin coating layer is controlled. It is characterized in that the resin coating layer has a function of improving the wear resistance of the layer.

  On the other hand, the graphitized particles used in the present invention provide uniform and minute irregularities on the surface of the resin coating layer, thereby providing uniform properties such as lubricity, conductivity, chargeability, and abrasion resistance. It is added to give to the layer.

  That is, when the graphitized particles having the characteristics used in the present invention as described above are used in the resin coating layer, they are easily dispersed uniformly and finely in the coating layer, and the micro unevenness formed on the surface of the resin coating layer. It becomes easy to control the shape to an appropriate size. Then, by forming the micro unevenness on the surface of the resin coating layer, the contact area with the toner particle surface is controlled, and the charge property of the graphitized particles makes it possible to charge up the toner on the surface of the resin coating layer or the toner. It is possible to stably and quickly impart uniform charging to the toner without causing contamination or toner fusion.

  In addition, the graphitized particles themselves used in the present invention have excellent lubricity, and the hardness difference between the resin and the coating resin is small due to having an appropriate hardness. It is durable and difficult to cut. In addition, even if the surface of the resin coating layer of minute uneven portions is scraped, it is easy to cut evenly, so that the minute uneven shape is maintained and the composition and characteristics of the resin coating layer surface are difficult to change even if it is durable. .

  By adopting such a configuration, the initial wear height of the surface coating layer of the developer carrying member can be controlled to 0.2 to 1.0 μm even in a large number of images, and the surface shape uniformity and surface material can be controlled. A change in composition can be suppressed and a stable image can be obtained. In addition, since the resin coating layer surface has the above-described configuration, irregular irregularities can be reduced, resulting in generation of streak-like image defects that are less likely to cause rubbing scratches and toner fusion to a regulating member (blade, etc.). We found an effect that it is difficult to obtain a stable image quality.

  That is, when the graphitized particles having the characteristics used in the present invention as described above are used, it becomes possible to disperse uniformly and finely in the resin coating layer, and the uneven shape that the graphitized particles form on the surface of the resin coating layer. The surface roughness is small and uniform, and wear resistance can be imparted to the surface of the coating layer while maintaining excellent lubricity.

  In addition to this, by setting the degree of graphitization of the particles within a specific range, the hardness of the graphitized particles becomes close to the hardness of the resin, so even if the resin coating layer is worn, it is evenly scraped, and the graphite coating again from the resin coating layer. The change in the surface composition is small because the exposed particles are exposed. For this reason, the initial wear height of the surface coating layer of the developer carrying member can be controlled to 0.2 to 1.0 μm even when a large number of images are printed, and the surface shape uniformity and surface material composition change are suppressed. In addition, it is possible to stabilize toner charging and transportability. In addition, since the surface of the resin coating layer has the above-described configuration, irregular irregularities are reduced and moderate lubricity is obtained, so that it is difficult to cause rubbing scratches and toner fusion to a regulating member (such as a blade). Found that streak-like image defects do not easily occur and a stable image quality can be obtained.

  Further, when the above-mentioned graphitized particles are contained in the resin coating layer on the surface of the developer carrier, the lubricity, conductivity, and charge imparting property of the coating layer surface become uniform, and toner charge up and toner fusion are performed on the coating layer surface. Without causing adhesion, it is possible to improve the ability of imparting triboelectric charge to toner more quickly and uniformly than when crystalline graphite is used.

  Therefore, when using a non-magnetic toner that carries toner on its surface due to the uneven shape of the developer carrier surface and electrostatic attraction due to electric charge, or spherical toner by a mechanical impact force etc. When used, the above effects can be more exhibited. In addition, as with conventional crystalline graphite, it has the effect of suppressing the mirror power of the developer and sleeve, preventing the developer from forming a non-moving layer on the sleeve and preventing proper charging. Stable charging can be performed. Furthermore, by incorporating the above graphitized particles in the resin coating layer on the surface of the developer carrying member, it is possible to improve the ability to impart quick and uniform frictional charge to the toner as compared with the case of using conventional crystalline graphite. This makes it possible to obtain a good image over a long period of time.

  The initial wear height Rpk here is a parameter of the surface property measured based on JIS B0671. As shown in FIG. 6, two points (A, B) are taken on the load curve (BAC) obtained from the measurement so that the difference in load length ratio (tp) is 40%, and these two points A, B Among the straight lines passing through, a straight line having the smallest inclination is obtained, and an intersection of this straight line and tp 0% is set as a point C. An intersection of the cutting level passing through the point C and the load curve is a point D, and an intersection of the load curve and tp 0% is a point E. At this time, when the point F is taken on tp0% so that the area surrounded by the line segment CD, the line segment CE, and the curve DE is equal to the area of the triangle CDF, the distance between the point C and the point F is set to the initial wear height. Rpk.

  The graphitization degree p (002) of the graphitized particles used in the present invention is 0.20 to 0.95. This p (002) is preferably 0.25 to 0.75, and more preferably 0.25 to 0.70.

  If p (002) exceeds 0.95, the resin coating layer is excellent in abrasion resistance, but the conductivity and lubricity may be reduced, causing toner charge-up, fogging, and image density. Etc., the image quality is likely to deteriorate. On the other hand, when p (002) is less than 0.20, the wear resistance of the graphitized particles is deteriorated, so that the wear resistance of the coating layer surface, the mechanical strength and transportability of the resin coating layer, and the rapid application to the toner. In addition, the uniform charge imparting property is lowered.

  It is preferable to set the initial wear height Rpk on the surface of the resin coating layer within the above range because irregular irregularities on the surface of the coating layer are reduced, rubbing scratches on the regulating blade are less likely to occur, and toner fusion can be suppressed. In order to control the initial wear height Rpk on the surface of the resin coating layer within a predetermined range, it is preferable to use graphitized particles having a sharp volume distribution in the particle size distribution. The ratio of the graphitized particles dispersed in the resin coating layer to a volume average particle size of 10 μm or more is preferably 5% by volume or less, and more preferably 2% by volume or less. When the ratio of the volume average particle diameter of 10 μm or more does not exceed 5% by volume, the initial wear height on the surface of the resin coating layer is easily controlled within a predetermined range.

  The graphitized particles in the resin coating layer are preferably dispersed in a volume average particle size of 0.5 to 4.0 μm. When the above volume average particle size is 0.5 μm or more, it is easier to obtain the effect of imparting lubricity and abrasion resistance to the resin coating layer, and it is possible to charge up the toner, wear the resin coating layer, and fuse the toner. It is hard to wake up. In particular, it is preferable to use an elastic blade and toner having a high degree of spheroidization in the developing process, because an effect of toner fusion is observed, and streaks, density unevenness, and the like are suppressed in the image. On the other hand, if the volume average particle size exceeds 4.0 μm, the initial wear height tends to exceed 1.0 μm, irregular irregularities increase on the surface of the resin coating layer, and rubbing scratches on the regulating blade easily occur. Wear is likely to occur.

  The particle size of the conductive particles such as the graphitized particles is measured using a Coulter LS-230 particle size distribution meter (manufactured by Beckman Coulter, Inc.) of a laser diffraction type particle size distribution meter. As a measuring method, a small amount module is used, and isopropyl alcohol (IPA) is used as a measuring solvent. Wash the measurement system of the particle size distribution analyzer with IPA for about 5 minutes, and execute the background function after washing.

  Next, 1 to 25 mg of a measurement sample is added to 50 ml of IPA. The solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser to obtain a sample solution. The sample solution is gradually added to the measurement system of the measurement device, and PIDS on the screen of the device is obtained. Is measured by adjusting the sample concentration in the measurement system such that the volume average particle diameter is calculated from the volume distribution.

  Control of the volume average particle size of the graphitized particles in the resin coating is achieved by adjusting the particle size distribution of the graphitized particles used by pulverization or classification and adjusting the dispersion strength of the graphitized particles in the resin coating. Is possible.

  As a method for obtaining graphitized particles having the above graphitization degree p (002), the following methods are preferable, but are not necessarily limited to these methods. A particularly preferable method for obtaining graphitized particles used in the present invention is to use particles having optical anisotropy such as mesocarbon microbeads and bulk mesophase pitch as raw materials and having a single phase. Graphitization is preferable in order to increase the degree of graphitization of the graphitized particles and maintain moderate hardness and a substantially spherical shape while maintaining lubricity.

  The optical anisotropy of the above-mentioned raw material is caused by the lamination of aromatic molecules, and the ordering is further developed by the graphitization treatment, and graphitized particles having a high degree of graphitization are obtained.

  When using the above bulk mesophase pitch as a raw material for obtaining graphitized particles used in the present invention, it is preferable to use a material that is softened and melted by heating in order to obtain spherical graphitized particles having a high degree of graphitization. .

  A typical method for obtaining the above-mentioned bulk mesophase pitch is, for example, a method for obtaining a bulk mesophase pitch by extracting β-resin from a coal tar pitch or the like by solvent fractionation, and performing hydrogenation and heavy processing. It is. Further, in the above-described method, the bulk mesophase pitch may be obtained by pulverizing after the heavy treatment and then removing the solvent-soluble component with benzene or toluene.

  This 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 hardly liquid-phase carbonized, and solid-phase carbonization causes the particles to remain in a crushed state, making it difficult to obtain a spherical one.

  A method for graphitizing the bulk mesophase pitch obtained as described above will be described below. First, the bulk mesophase pitch is finely pulverized to 2 to 25 μm, and this is lightly oxidized by heat treatment at about 200 ° C. to 350 ° C. in air. By this oxidation treatment, only the surface of the bulk mesophase pitch is infusible, and melting and fusing during the graphitization firing in the next step are prevented. The oxidized bulk mesophase pitch preferably has an oxygen content of 5 to 15% by mass. If the oxygen content is less than 5% by mass, it is not preferable because the fusion of particles during heat treatment is severe, and if it exceeds 15% by mass, the inside of the particles will be oxidized, and the shape will be graphitized and spherical while being crushed. Is difficult to obtain.

  Next, the oxidized bulk mesophase pitch is carbonized by primary firing at about 800 ° C. to 1200 ° C. in an inert atmosphere such as nitrogen and argon, and then secondary at about 2000 ° C. to 3500 ° C. By firing, desired graphitized particles are obtained.

  In addition, representative examples of methods for obtaining mesocarbon microbeads, which are another preferred raw material for obtaining graphitized particles used in the present invention, are given below. First, coal-based heavy oil or petroleum-based heavy oil is heat-treated at a temperature of 300 ° C. to 500 ° C. and polycondensed to produce crude mesocarbon microbeads. Obtained by separating the mesocarbon microbeads by subjecting the obtained reaction product to treatments such as filtration, stationary sedimentation, and centrifugation, followed by washing with a solvent such as benzene, toluene, xylene, and drying. .

  When graphitizing the obtained mesocarbon microbeads, it is possible to prevent the coalescence of the particles after graphitization by first mechanically dispersing the mesocarbon microbeads after drying with a gentle force that does not cause destruction. It is preferable for obtaining a uniform particle size.

  The mesocarbon microbeads that have finished primary dispersion are primarily fired and carbonized at a temperature of 200 ° C. to 1500 ° C. in an inert atmosphere. It is preferable for the carbide after the primary firing to mechanically disperse the carbide with a mild force that does not destroy the carbide in order to prevent coalescence of the particles after graphitization and to obtain a uniform particle size.

  The carbide that has undergone the primary firing is subjected to secondary firing at about 2000 ° C. to 3500 ° C. in an inert atmosphere to obtain desired graphitized particles.

  In order to make the surface shape of the resin coating layer uniform for the graphitized particles obtained from any of the above raw materials, it is possible to keep the particle size distribution uniform to some extent by classification, regardless of which method is used. Is preferable.

  In any method for producing graphitized particles using any raw material, the graphitization firing temperature is preferably 2000 ° C to 3500 ° C, more preferably 2300 ° C to 3200 ° C.

  When the graphitization firing temperature is less than 2000 ° C., the graphitized particles have insufficient degree of graphitization, which may lower the conductivity and lubricity and cause toner charge-up. Etc., the image quality is likely to deteriorate. In addition, when the firing temperature is higher than 3500 ° C., the graphitized particles may have a too high degree of graphitization, so that the hardness of the graphitized particles is lowered and the wear resistance of the graphitized particles is deteriorated. The abrasion resistance, the mechanical strength of the resin coating layer, the toner transport stability, and the charge imparting property to the toner are likely to deteriorate.

  In the present invention, in addition to the above resin coating layer structure, further specific characteristics can be obtained by further adding the specific quaternary ammonium salt compound shown below.

  In Patent Documents 3 and 4, toners that have been spheroidized by adding a quaternary ammonium salt compound that is positively charged with respect to iron powder into the resin, or negative toners that are produced by a polymerization method are disclosed in Patent Documents 3 and 4. On the other hand, a prior art using a developing sleeve that prevents excessive charging such as charge-up has been proposed.

  Although this method is effective for preventing the charge-up phenomenon and improving the uniformity of charging, it is still insufficient.

  In particular, when using a non-magnetic one-component toner that does not have a magnetic material produced by a polymerization method and uses a non-contact type developing device that performs development in a non-contact state between a photosensitive drum and a developer carrier as described below, The charging stability and conveyance stability for toner have not been sufficiently solved yet.

  As a result of various studies to solve the above-mentioned problems, the resin coating layer of the developer carrying member containing the graphitized particles having a specific degree of graphitization used in the present invention and having a specific initial wear height Rpk is used. Furthermore, it has been found that charging stability and conveying stability for the toner can be obtained by including a quaternary ammonium salt compound that is positively charged with respect to the iron powder.

  In particular, by using the developer carrying member having the constitution of the present invention, good charging stability to a non-magnetic and highly spheroidized negatively charged toner produced by a spheroidizing toner or a polymerization method, etc. Performance and conveyance stability can be exhibited.

  In general, a developer produced by a polymerization method has a great advantage in that transferability of toner is remarkably improved and transfer efficiency is improved as compared with a developer produced by a conventional jet milling method. On the other hand, since a coloring material such as carbon is taken into the inside of the particle, it is difficult for the charge to escape on the surface of the toner particle, and it is easy to charge up. As a result, uneven development, blotches, and density reduction due to toner sleeve fixation are likely to occur. This is particularly noticeable in non-magnetic developers that do not have a magnetic material.

  In addition to the developer carrier structure of the present invention, by adding a specific quaternary ammonium salt compound to a specific resin as a binder material, it contains graphitized particles having a specific degree of graphitization. In addition to the effect of rapid and highly stable charge application and transport stability by the developer carrying member of the present invention having an initial wear height Rpk, the toner is negatively chargeable and non-magnetic and has a high degree of spheroidization that tends to be excessively charged. On the other hand, by suppressing the charge imparting ability of the resin coating layer of the developer carrying member as a whole, it is possible to prevent excessive charging and to obtain toner charge quickly, appropriately and uniformly.

  The exact reason why a quaternary ammonium salt compound, which has been known as a positive charge control agent for conventional toners, contributes to charge stabilization of negatively chargeable toners is not clear, but is presumed as follows. When a quaternary ammonium salt compound that is positively charged with respect to iron powder is added to the resin coating layer on the developer carrying member having the structure according to the present invention, the resin is uniformly dispersed in the resin, and the resin is formed when the coating is formed. It is considered that the binder resin composition itself becomes negatively charged by being incorporated into the structure of a resin having a functional group such as amino group, ═NH or —NH— in the inside. For this reason, the negatively chargeable toner works in a direction that prevents the toner from having an excessive negative charge amount, and as a result, the negative charge amount can be stably controlled.

  Also in the present invention, by containing the quaternary ammonium salt compound in the developer-carrying resin coating layer having the configuration of the present invention, the charge imparting property to the resin coating layer by the graphitized particles having a specific degree of graphitization, Coupled with effects such as lubricity, it is possible to obtain high charging stability and conveyance stability for a non-magnetic polymer toner that is particularly susceptible to charge-up.

  As the quaternary ammonium salt compound having the above-mentioned function suitably used in the present invention, any compound may be used as long as it has a positive chargeability with respect to iron powder. And the compounds represented.

（式中のＲ₁，Ｒ₂，Ｒ₃及びＲ₄は、夫々置換基を有してもよいアルキル基、置換基を有してもよいアリール基、アルアルキル基を表し、Ｒ₁〜Ｒ₄は夫々同一でも或いは異なっていても良い。Ｘ^-は酸の陰イオンを表す。）

(Wherein R ₁ , R ₂ , R ₃ and R ₄ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, and an aralkyl group, respectively, R _{1 to} R ₄ may be the same or different, and X ⁻ represents an anion of an acid.)

In the aforementioned general formula, specific examples of the acid ion of X ⁻ include organic sulfate ion, organic sulfonate ion, organic phosphate ion, molybdate ion, tungstate ion, heteropoly acid containing molybdenum atom or tungsten atom, and the like. Preferably used.

    Specific examples of the quaternary ammonium salt compound that is preferably used in the present invention and is positively charged with respect to iron powder include the following. However, it is not limited to these.

  The amount of the quaternary ammonium salt compound used in the present invention as described above is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the binder resin. If the amount is less than 1 part by mass, the effect of controlling the charge amount due to the addition is not observed. If the amount exceeds 100 parts by mass, the abundance in the binder resin becomes excessive and the properties of the original resin are impaired, and the coating strength is liable to decrease. .

  In addition, as a preferable resin containing at least one of an amino group, = NH or -NH- in the structure in combination with the quaternary ammonium salt, phenol produced using a nitrogen-containing compound as a catalyst in the production process Examples thereof include a resin, a polyamide resin, an epoxy resin using polyamide as a curing agent, a urethane resin, or a copolymer partially containing these resins. The quaternary ammonium salt compound is easily taken into the structure of the coating resin when the mixture with the coating resin is formed.

  In the present invention, as a phenol resin that can be suitably used in combination with the quaternary ammonium salt compound, a nitrogen-containing compound used as a catalyst in the production process includes, for example, ammonium sulfate and ammonium phosphate as acidic catalysts. , Ammonium salts such as ammonium sulfamate, ammonium carbonate, ammonium acetate, and ammonium maleate, or amine salts. Basic catalysts include ammonia or dimethylamine, diethylamine, diisopropylamine, diisobutylamine, diamylamine, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, dimethylbenzylamine, diethylbenzylamine, dimethylaniline, diethylaniline. N, N-di-n-butylaniline, N, N-diamilaniline, N, N-di-t-amylaniline, N-methylethanolamine, N-ethylethanolamine, diethanolamine, triethanolamine, dimethylethanolamine , Diethylethanolamine, ethyldiethanolamine, n-butyldiethanolamine, di-n-butylethanolamine, triisopropanolamine, ethylenediamine, hexamethyl Amino compounds such as tetramine; pyridines such as pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, and derivatives thereof; quinoline compounds, imidazole, 2-methylimidazole, 2, Examples include nitrogen-containing heterocyclic compounds such as 4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, imidazole such as 2-heptadecylimidazole, and derivatives thereof. It is done.

  Further, examples of the polyamide resin constituting the coating resin suitably used in the present invention include nylon 6, 66, 610, 11, 12, 9, 13, Q2 nylon, and the like, or nylons mainly composed of these. Any of polymers, N-alkyl-modified nylon, N-alkoxylalkyl-modified nylon, and the like can be used preferably. Furthermore, any resin containing a polyamide resin such as various resins modified with polyamide such as a polyamide-modified phenol resin or an epoxy resin using a polyamide resin as a curing agent may be used. Can be used.

  Moreover, as a urethane resin which comprises the coating resin used suitably in combination with the said quaternary ammonium salt compound by this invention, all can be used if it is resin containing a urethane bond. This urethane bond is obtained by polymerization addition reaction of polyisocyanate and polyol. Polyisocyanates that are the main raw materials for this polyurethane resin include TDI (tolylene diisocyanate), pure MDI (diphenylmethane diisocyanate), polymeric MDI (polymethylene polyphenyl polyisocyanate), TODI (tolidine diisocyanate), NDI (naphthalene diisocyanate), and the like. Aromatic polyisocyanates such as: HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), XDI (xylylene diisocyanate), hydrogenated XDI (hydrogenated xylylene diisocyanate), aliphatic MDI (dicyclohexylmethane diisocyanate), etc. And polyisocyanates.

  Polyols that are the main raw materials for this polyurethane resin include polyether polyols such as PPG (polyoxypropylene glycol), polymer polyols, and polytetramethylene glycol (PTMG); polyester polyols such as adipate, polycaprolactone, and polycarbonate polyols. Polyether modified polyols such as PHD polyol and polyether ester polyol; other epoxy-modified polyols; partially saponified polyols of ethylene-vinyl acetate copolymer (saponified EVA); flame retardant polyols and the like.

In the present invention, the volume resistance of the resin coating layer of the developer carrying member is preferably 10 ⁻² to 10 ⁵ Ω · cm, and more preferably 10 ⁻² to 10 ⁴ Ω · cm. When the volume resistance of the resin coating layer exceeds 10 ⁵ Ω · cm, the toner is likely to be charged up and toner contamination to the resin coating layer is likely to occur.

  In the present invention, in order to adjust the volume resistance of the resin coating layer to the above value, other conductive fine particles may be dispersed in the resin coating layer in combination with the graphitized particles.

  The conductive fine particles preferably have a number average particle diameter of preferably 1 μm or less, more preferably 0.01 to 0.8 μm. When the number average particle size of the conductive fine particles dispersed and contained in combination with the graphitized particles in this resin coating layer is 1 μm or less, the volume resistance of the resin coating layer is easily controlled to be low, and the charge of the toner is increased. It is possible to prevent toner contamination.

  Examples of the conductive fine particles that can be used in the present invention include carbon black such as furnace black, lamp black, thermal black, acetylene black, channel black; titanium oxide, tin oxide, zinc oxide, molybdenum oxide, potassium titanate. And metal oxides such as antimony oxide and indium oxide; metals such as aluminum, copper, silver and nickel; and inorganic fillers such as metal fibers and carbon fibers.

  As the addition amount of the conductive fine particles in the coating layer described above, a preferable result is a range of 100 parts by mass or less with respect to 100 parts by mass of the binder resin. When the addition amount exceeds 100 parts by mass, the coating strength is likely to decrease.

  Next, the configuration of the developer carrying member used in the present invention will be described.

  The developer carrying member of the present invention is mainly composed of a substrate and a resin layer surrounding and covering the substrate. Examples of the substrate of the developer carrier include a cylindrical member, a columnar member, and a belt-like member. In the development method without contact with the drum, a resin molded body or a rigid cylindrical tube or solid rod such as a nonmagnetic metal or alloy such as aluminum, stainless steel, or brass is preferably used. These substrates are used after being molded or processed with high accuracy in order to improve the uniformity of the image. Aluminum is preferably used because of material cost and ease of processing.

  Further, as the substrate having an elastic layer, a core member and a cylindrical member having a layer structure including rubber, elastomer such as urethane, EPDM, silicon, etc. are particularly preferable in the case of a developing method in which a developer carrier is directly brought into contact with a drum. Used.

  The composition ratio of each component constituting the resin coating layer will be described, but this is a particularly preferable range in the present invention.

  The content of the 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 coating resin. The effect of maintaining the surface shape and imparting charge to the toner is more exhibited. 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 becomes too low and the wear resistance deteriorates. May end up.

  The content of the conductive fine particles that can be contained in the resin coating together with the graphitized particles is preferably 40 parts by mass or less, more preferably 2 to 35 parts by mass with respect to 100 parts by mass of the coating resin. This is more preferable because the volume resistance can be adjusted to a desired value as described above without impairing other physical properties required for the layer. The case where the content of the conductive fine particles is 40 parts by mass or less is more preferable because sufficient strength can be obtained in the resin coating layer.

  In the present invention, the initial wear height Rpk of the resin coating layer (hereinafter referred to as “Rpk”) is preferably 0.2 to 1.0 μm, more preferably 0.2 to 0.8 μm. preferable. When the Rpk on the surface of the resin coating layer is less than 0.2 μm, the toner is likely to be fused to a regulating member such as a regulating blade, and the toner is transported to the surface of the resin coating layer at an initial stage where charging to the toner is insufficient. It is difficult to form unevenness for sufficient performance, and the toner transportability on the developer carrying member cannot be kept stable. When Rpk on the surface of the resin coating layer is larger than 1.0 μm, the rubbing force applied to the developer is likely to increase, and streak-like scratches on the regulation blade due to irregular irregularities are likely to occur. Further, the change in the surface shape of the developer carrying member during durability tends to increase, and the mechanical strength of the resin coating layer tends to decrease. Further, since proper transportability of the developer cannot be obtained, it is difficult to obtain uniform toner charging.

The layer thickness of the resin coating layer having the above-described structure 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 film thickness. It is not limited. Although these layer thicknesses depend on the material used for the resin coating layer, they can be obtained when the adhesion weight is about 4000 to 20000 mg / m ² .

  1 and 2, graphitized particles a having a specific degree of graphitization used in the present invention are dispersed in a binder resin b to form a resin coating layer b having a specific initial wear height. It is a schematic diagram of the cross section which shows a mode. Reference numeral 5 denotes a substrate made of a metal cylindrical tube. In FIG. 1, graphitized particles a are dispersed in a binder resin b, and relatively small irregularities are formed on the surface of the resin coating layer 7, conductivity is imparted, releasability to toner, and charge impartability to toner. It contributes to. In FIG. 2, the graphitized particles a form relatively large irregularities on the surface of the resin coating layer 6, and the conductive fine particles c are added to the binder resin b in addition to the graphitized particles a to make the conductivity. The conductive fine particle c itself does not contribute much to the formation of substantial unevenness. However, not only the conductive fine particles c but also a mode in which minute irregularities are formed by another added solid particle is included.

  As described above, in the present invention, according to the additional function required for the developer carrier and the difference in the development method, the particle sizes of the graphitized particles and the conductive fine particles are respectively adjusted to adjust the particle sizes of the above-described aspects. It is possible to form a resin coating layer.

  The method for forming the resin coating layer of the present invention is not particularly limited. For example, a coating solution containing the composition of the present invention is dipped, sprayed, or brushed onto a substrate of a developer carrier. The developer carrier of the present invention can be obtained by applying and drying by the above method.

  Next, the developing device of the present invention in which the developer carrier of the present invention as described above is incorporated will be described. The developer carrying member of the present invention exhibits its effect particularly when a nonmagnetic one-component developer is used, but it can also be used for a magnetic developer or a two-component developer.

  FIG. 3 schematically shows an example of the configuration of a developing device used when a nonmagnetic one-component developer is used.

  In FIG. 3, an image carrier that carries an electrostatic latent image formed by a known process, for example, an electrophotographic photosensitive drum 1 is rotated in the direction of arrow B. A developing sleeve 7 as a developer carrying member is composed of a metal cylindrical tube (base) 5 and a resin coating layer 6 formed on the surface thereof. In order to use a non-magnetic one-component developer, no magnet is provided in the metal cylindrical tube 5. A columnar member can be used instead of the metal cylindrical tube.

  A stirring blade 9 for stirring the nonmagnetic one-component developer 3 is provided in the hopper 2 that is a developing device.

  A developer supplying / peeling member 12 for supplying the developer 3 to the developing sleeve 7 and stripping off the developer 4 existing on the surface of the developing sleeve 7 after development is in contact with the developing sleeve 7. When the supply / peeling roller 12 as a developer supply / peeling member rotates in the same direction as the developing sleeve 7, the surface of the supply / peeling roller 12 moves in the counter direction with the surface of the developing sleeve 7. The one-component non-magnetic developer 3 supplied from the hopper 2 is supplied to the developer sleeve 7, and the developing sleeve 7 carries the one-component developer 3 and rotates in the direction of arrow A, thereby developing. The non-magnetic one-component developer 3 is conveyed to the developing portion D where the sleeve 7 and the photosensitive drum 1 face each other. The developer layer thickness of the one-component developer 3 carried on the developing sleeve 7 is defined by a developer layer thickness regulating member 10 that is pressed against the surface of the developing sleeve 7 via the developer layer. The nonmagnetic one-component developer 3 obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 1 by friction with the developing sleeve 7.

  The thickness of the thin layer of the nonmagnetic one-component developer 3 formed on the developing sleeve 7 is preferably thinner than the minimum gap D between the developing sleeve 7 and the photosensitive drum 1 in the developing portion. The present invention is particularly effective for a non-contact type developing apparatus that develops an electrostatic latent image with such a developer layer. However, the present invention can also be applied to a contact-type developing device in which the thickness of the developer layer in the developing portion is equal to or greater than the minimum gap D between the developing sleeve 7 and the photosensitive drum 1.

  In order to avoid complicated explanation, in the following explanation, a non-contact developing device is taken as an example.

  A developing bias voltage is applied to the developing sleeve 7 by a power source 8 in order to fly the one-component nonmagnetic developer 3 having nonmagnetic toner carried on the developing sleeve 7. When a DC voltage is used as the developing bias voltage, a voltage having a value between the potential of the image portion of the electrostatic latent image (the region visualized with the nonmagnetic developer 3 attached) and the potential of the background portion is It is preferable to apply to the developing sleeve 7. 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 7 to form an oscillating electric field whose direction is alternately reversed in the developing portion. In this case, it is preferable that an alternating bias voltage on which a DC voltage component having a value between the image portion potential and the background portion potential is superimposed is applied to the developing sleeve 7.

  In so-called regular development in which a developer is attached to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion for visualization, a developer charged with a polarity opposite to that of the electrostatic latent image is used. In so-called reversal development in which toner is attached to a low potential portion of an electrostatic latent image for visualization, a developer charged with the same polarity as the polarity of the electrostatic latent image is used. High potential and low potential are expressed by absolute values. In any case, the nonmagnetic one-component developer 3 is charged with a polarity for developing the electrostatic latent image by friction with the developing sleeve 7.

  As the developer supply / peeling member, an elastic roller member such as resin, rubber or sponge is preferable. As the stripping member, a belt member or a brush member can be used instead of the elastic roller. The developer that has not been transferred to the photosensitive member 1 is once peeled off from the sleeve surface by the developer supply / peeling member 12 to prevent the development of a stationary developer on the sleeve, or to uniformly charge the developer. Has the function of

  When the supply / peeling roller 12 made of an elastic roller is used as the developer supply / peeling member, the peripheral speed of the supply / peeling roller 12 is the peripheral speed of the developing sleeve 8 when the surface rotates in the counter direction. It is preferably 20 to 120%, more preferably 30 to 100% with respect to 100%.

  When the peripheral speed of the supply / peeling roller 12 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. The supply amount of the developer is increased, causing fogging due to poor regulation of the developer layer thickness and insufficient charge amount, and further easily damaging the toner, which is likely to cause fogging and toner fusion due to toner deterioration.

  When the rotation direction of the supply / peeling roller is the same (forward) direction as the surface of the developing sleeve, the peripheral speed of the supply roller is preferably 100 to 300%, more preferably 101 to 100% of the sleeve peripheral speed. The toner supply amount may be 200%.

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

  The penetration amount of the developer supply / peeling member 12 with respect to the developing sleeve 7 is preferably 0.5 to 2.5 mm from the viewpoint of developer supply and peelability.

  When the amount of penetration of the developer supply / peeling member 13 is less than 0.5 mm, ghosting is likely to occur due to insufficient peeling, and when the penetration amount exceeds 2.5 mm, toner damage is large. Therefore, the toner is likely to cause fusing and fogging due to toner deterioration.

  In the developing device of FIG. 3, as a member for regulating the layer thickness of the non-magnetic one-component developer 3 on the developing sleeve 8, a material having rubber elasticity such as urethane rubber or silicone rubber, or phosphor bronze, stainless copper or the like is used. The elastic regulating blade 10 made of a material having metal elasticity is used, and the elastic regulating blade 10 is brought into pressure contact with the developing sleeve 7 in a posture opposite to the rotation direction in the developing device of FIG. Can be formed.

  As this elastic regulating blade 10, a polyamide elastomer (PAE) is pasted on the surface of a phosphor bronze plate which can obtain a stable pressure, particularly for a stable regulating force and a stable (negative) chargeability to the toner. It is preferable to use one having a different structure. Examples of the polyamide elastomer (PAE) include a copolymer of polyamide and polyether.

  The contact pressure of the developer layer thickness regulating member 10 against the developing sleeve 7 is that the linear pressure is 5 to 50 g / cm, so that the regulation of the developer can be stabilized and the developer layer thickness can be made suitable. Is preferable.

  When the contact pressure of the developer layer thickness regulating member 10 is less than the linear pressure of 5 g / cm, the regulation of the developer becomes weak, causing fogging and toner leakage, and when the linear pressure exceeds 50 g / cm. In addition, damage to the toner is increased, and the toner is likely to be deteriorated and fused to the sleeve and the blade.

  The developer carrying member of the present invention is particularly effective when applied to an apparatus in which the developer supply / stripping member 12 and the developer layer thickness regulating member 10 are pressed against such a developing sleeve 7.

  That is, when the developer supply / peeling member 12 and the developer layer thickness regulating member 10 are pressed against the developing sleeve 7, the surface of the developing sleeve 7 is worn or the developer is not pressed by these pressed members. Since it is in a use environment in which fusion is more likely to occur, the effect of the developer carrier having the resin coating layer excellent in durability of a large number of sheets of the present invention is effectively expressed.

  FIG. 4 is a schematic configuration diagram showing another embodiment of the developing device of the present invention.

  The developing device shown in FIG. 4 is characterized in that a developer layer thickness regulating member that regulates the layer thickness of the developer 3 on the developing sleeve 7 is in pressure contact with the rotation direction of the developing sleeve 7 in the forward direction. is there. The other basic configuration of the developing device of FIG. 4 is the same as that of the developing device shown in FIG. 3, and the components having the same reference numerals basically indicate the same members.

  3 and 4 merely illustrate the developing device of the present invention to the last, and it goes without saying that there are various forms such as the shape of the developer container (hopper 2) and the presence or absence of the stirring blade 9. FIG. 5 is a schematic diagram of a developing device according to an embodiment having the developer carrying member of the present invention used when a magnetic one-component developer is used.

  In FIG. 5, a magnet roller 4 is disposed in the developing sleeve 7 in order to magnetically attract and hold the developer 3 on the developing sleeve 7.

  Hereinafter, the developer used in the present invention will be described.

  The toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method. When the polymerization method is used in the toner manufacturing method of the present invention, the toner can be specifically manufactured by the following manufacturing method. Add a release agent, polar resin, colorant, charge control agent, polymerization initiator and other additives to the monomer, and disperse the monomer system that has been uniformly dissolved or dispersed by a homogenizer, ultrasonic disperser, etc. Disperse in an aqueous phase containing a stabilizer with a normal stirrer, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the monomer droplets have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. Polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the latter half of the reaction, or the completion of the reaction. A part of the aqueous medium may be distilled off later. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

  Cross-linking agents include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline , Divinyl ether, divinyl sulfide, divinyl compounds such as divinyl sulfone; and compounds having three or more vinyl groups. Particularly preferred is divinylbenzene.

  As a preferable addition amount of the crosslinking agent, the crosslinking agent is preferably 0.01 to 1.0 part by mass per 100 parts by mass of the vinyl polymer or vinyl copolymer. More preferably, it is 0.1-0.9 mass part.

  The wax contained in the yellow toner, magenta toner, and cyan toner used in the present invention is preferably a solid wax that is solid at room temperature. There are no restrictions on polymerized toner and pulverized toner. Specific examples include paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, and derivatives such as graft compounds and block compounds.

  In the present invention, the wax is preferably added to the toner particles in an amount of 5 to 30% by mass, and the toner used in the present invention preferably contains 5 to 30% by mass of the wax. When the addition amount is less than 5% by mass, the high-temperature offset resistance is deteriorated, and further, the image on the back surface may show an offset phenomenon when fixing a double-sided image. When the amount is more than 30% by mass, toner particles are likely to be coalesced during granulation in the production by the polymerization method, and those having a wide particle size distribution are likely to be generated. Further, from this, the encapsulation of the wax becomes insufficient, and developability, transferability, and blocking resistance deteriorate. Therefore, the uniformity of the image is also inferior.

  For the purpose of controlling the chargeability of the toner, it is preferable to add a charge control agent to the toner particles.

  Of these known charge control agents, those having little polymerization inhibition and aqueous phase transfer are preferred. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, guanidine derivatives, imidazole derivatives, amine compounds, and the like. Examples of negative charge control agents include metal-containing salicylic acid copolymers, metal-containing monoazo dye compounds, urea derivatives, styrene-acrylic acid copolymers, and styrene-methacrylic acid copolymers.

  The addition amount of these charge control agents is preferably 0.1 to 10% by mass of the binder resin or polymer monomer.

  Known colorants can be used as the colorant used in the toner of the present invention.

  For example, examples of the black pigment include carbon black, aniline black, nonmagnetic ferrite, and magnetite.

  Examples of yellow pigments include yellow iron oxide, navel yellow, naphthol yellow S, hanzer yellow G, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake.

  Examples of the orange pigment include permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK.

  Examples of red pigments include Bengala, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red C, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Eoxin Lake, Rhodamine Lake B, and Alizarin Lake. It is done.

  Examples of the blue pigment include alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, first sky blue, and indanthrene blue BG.

  Examples of purple pigments include fast violet B and methyl violet lake.

  Examples of the green pigment include Pigment Green B, Malachite Green Lake, and Final Yellow Green G.

  Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.

  These colorants can be used alone or in combination, and further in a solid solution state.

  The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The added amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  As the colorant when the toner of the present invention is used as a translucent color toner, various types and pigments of various colors as shown below can also be used.

  For example, C.I. I. 10316 (Naphthol Yellow S), C.I. I. 11710 (Hansa Yellow 10G), C.I. I. 11660 (Hanza Yellow 5G), C.I. I. 11670 (Hanza Yellow 3G), C.I. I. 11680 (Hansa Yellow G), C.I. I. 11730 (Hansa Yellow GR), C.I. I. 11735 (Hansa Yellow A), C.I. I. 117408 (Hansa Yellow RN), C.I. I. 12710 (Hansa Yellow R), C.I. I. 12720 (Pigment Yellow L), C.I. I. 21090 (benzidine yellow), C.I. I. 21095 (Benzidine Yellow G), C.I. I. 21100 (Benzidine Yellow GR), C.I. I. 20040 (Permanent Yellow NCR), C.I. I. 21220 (Vulcan Fast Yellow 5), C.I. I. 21135 (Vulcan Fast Yellow R).

  Examples of red pigments include C.I. I. 12055 (Starlin I), C.I. I. 12075 (permanent orange), C.I. I. 12175 (Risor Fast Orange 3GL), C.I. I. 12305 (permanent orange GTR), C.I. I. 11725 (Hansa Yellow 3R), C.I. I. 21165 (Vulcan Fast Orange GG), C.I. I. 21110 (Benzidine Orange G), C.I. I. 12120 (Permanent Red 4R), C.I. I. 1270 (Para Red), C.I. I. 12085 (Fire Red), C.I. I. 12315 (Brilliant Fast Scarlet), C.I. I. 12310 (Permanent Red F2R), C.I. I. 12335 (Permanent Red F4R), C.I. I. 12440 (Permanent Red FRL), C.I. I. 12460 (Permanent Red FRLL), C.I. I. 12420 (Permanent Red F4RH), C.I. I. 12450 (Light Fast Red Toner B), C.I. I. 12490 (Permanent Carmine FB), C.I. I. 15850 (brilliant carmine 6B).

  Examples of blue pigments include C.I. I. 74100 (metal-free phthalocyanine blue), C.I. I. 74160 (phthalocyanine blue), C.I. I. 74180 (Fast Sky Blue).

  An external additive may be added to the toner of the present invention for the purpose of imparting various properties. The external additive preferably has a particle size of 1/10 or less of the volume average diameter of the toner particles from the viewpoint of durability when added to the toner. The particle diameter of the external additive means the average particle diameter obtained by observing the surface of the toner particles with an electron microscope. As external additives for the purpose of imparting these characteristics, for example, the following are used.

  1) Fluidity imparting agent: metal oxide (silicon oxide, aluminum oxide, titanium oxide), carbon black and carbon fluoride. Those subjected to hydrophobic treatment are more preferable.

  2) Abrasive: metal oxide (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide), nitride (silicon nitride), carbide (silicon carbide) and metal salt (calcium sulfate, barium sulfate, calcium carbonate) ).

  3) Lubricant: fluororesin powder (vinylidene fluoride, polytetrafluoroethylene) and fatty acid metal salt (zinc stearate, calcium stearate).

  4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide) and carbon black.

  These external additives may be used preferably in the range of 0.1 to 10 parts by mass, more preferably in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner particles. These external additives may be used alone or in combination.

  Toner particle size distribution control and particle size control can be done by changing the type and amount of a poorly water-soluble inorganic salt or protective colloid dispersant and mechanical device conditions such as rotor peripheral speed, number of passes, and stirring blades. The predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape, the container shape, or the solid content concentration in the aqueous solution.

  In the present invention, any appropriate stabilizer is used for the dispersion medium used in the production of the polymerization toner. For example, as an inorganic compound, tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Fine powders of inorganic compounds such as bentonite, silica and alumina. Organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, polymethacrylic acid and salts thereof, and starch may be used.

  In the present invention, it is necessary to pay attention to the polymerization inhibitory property and water phase migration property of the colorant as the colorant used in the polymerization method toner. The colorant is preferably used for surface modification, for example, polymerization inhibition. It is better to apply a hydrophobic treatment. In particular, dyes and carbon blacks have a polymerization inhibition property, so care must be taken when using them. A preferable method for surface-treating the dye system includes a method of polymerizing a polymerizable monomer in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system. Carbon black may be treated with a substance that reacts with the surface functional group of carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

  The toner of the present invention may contain a charge control agent.

  For high image quality, the toner preferably has a weight average particle diameter (D4) of 4 to 8 μm. A toner having a weight average particle diameter of less than 4 μm is not preferable because it tends to cause uneven image unevenness due to fogging or transfer failure. If the toner has a weight average particle diameter exceeding 8 μm, fusion or the like is likely to occur. .

  The average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Beckman Coulter, Inc.). ) And a PC9801 personal computer (manufactured by NEC) and an interface for outputting the number distribution and volume distribution are connected, and an approximately 1% NaCl aqueous solution is prepared using first-grade sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number distribution are measured by measuring the volume and number of toners of 2 μm or more using the Coulter Multisizer with a 100 μm aperture. And calculate.

  Then, a volume-based weight average particle diameter (D4) obtained from the volume distribution and a number-based number average particle diameter (D1) obtained from the number distribution are obtained.

  Further, in the circularity (frequency distribution) based on the number of toners measured by the flow type particle image measuring apparatus, the average circularity is preferably 0.970 or more from the viewpoint of transfer rate.

The circularity of the toner in the present invention is used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow type particle image measuring device “FPIA-1000” (manufactured by Toa Medical Electronics Co., Ltd.) is used. ) And measured using the following formula.
Circularity a calculated from the following formula (1)
Circularity a = L0 / L (1)
[In the formula, L0 represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. ]

  Here, the same projected area as the particle image is the area of the binarized toner particle image, and the peripheral length of the particle image is defined as the length of the contour line obtained by connecting the edge points of the toner particle image. .

  The circularity in the present invention is an index indicating the degree of unevenness of the toner, and is 1.000 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity.

The average circularity a _ave, which means the average value of the circularity frequency distribution, is calculated from the following equation where the circularity (center value) at the dividing point I of the particle size distribution is a _I and the frequency is fa _i .

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “UH-50 type” (manufactured by SMT Co., Ltd.) equipped with a 5φ titanium alloy chip as a vibrator is used, and a dispersion for measurement is performed using a dispersion treatment for 5 minutes. To do. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more.

  For the toner shape measurement, the flow type particle image measuring device is used, the concentration of the dispersion is adjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl, and 1000 or more toner particles are measured. After measurement, the circularity frequency distribution of the toner is obtained using this data.

  In the case of a pulverized toner, a known method is used. For example, binder resin, charge control agent, if necessary, wax, magnetic substance, colorant, other additives, etc. are thoroughly mixed by a mixer such as a Henschel mixer or a ball mill, and then heated rolls, kneaders, extruders Using such a heat kneader, the mixture is melt-kneaded, cooled, solidified, pulverized, and classified to obtain colored particles. Surface treatment may be performed as necessary. Thereafter, an inorganic fine powder is added and mixed to obtain a toner. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier using the Coanda effect in terms of production efficiency. In order to improve the image quality, the weight average particle diameter (D4) of the toner is preferably 3 to 8 μm, and more preferably 4 to 8 μm.

  For spheroidization and surface smoothing for the purpose of improving transferability, the pulverized toner particles are dispersed in water, heated in a bath, heated in a hot air stream, and treated by applying mechanical energy. And mechanical impact method. In the mechanical impact method, a thermomechanical impact in which the treatment temperature is a temperature in the vicinity of the glass transition point Tg (Tg ± 10 ° C.) of the toner particles is preferable from the viewpoint of aggregation prevention and productivity.

  The binder resin used in the pulverized toner includes polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-p-chlorostyrene copolymer, styrene vinyltoluene copolymer, and styrene and its substituted single weight. Copolymers and copolymers thereof; copolymers of styrene and acrylate esters such as styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-n-butyl acrylate copolymer; styrene- Copolymers of styrene and methacrylic ester such as methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-n-butyl methacrylate copolymer; multi-component copolymer of styrene, acrylic ester and methacrylic ester Polymer: Styrene-acrylonitrile copolymer, styrene-vinyl Styrene and other vinyl monomers such as dimethyl ether copolymer, styrene-butadiene copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile indene copolymer, styrene-maleic acid ester copolymer. Styrene copolymer: polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyester, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid, phenol resin, aliphatic or alicyclic hydrocarbon resin, petroleum resin, chlorination Paraffin is exemplified. These can be used alone or in combination. In particular, low-molecular-weight polyethylene, low-molecular-weight polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, higher fatty acid, polyamide resin, and polyester resin are used alone as a binder resin for toners used in the pressure fixing method. Or you can use it together.

  As comonomer for constituting the styrene copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, Monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a derivative thereof, maleic acid, butyl maleate, methyl maleate, maleic acid Examples thereof include dicarboxylic acids having a double bond such as dimethyl and derivatives thereof.

  Particularly preferred resins for non-magnetic pulverized toners (yellow, magenta, cyan, black) include styrene-acrylic acid ester resins and polyester resins.

  As the colorant, the same colorant as that of the polymerization toner can be used. The content is 12 parts by mass or less, preferably 0.5 to 9 parts by mass with respect to 100 parts by mass of the binder resin.

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

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

The lattice interval d (002) is CuKα as an X-ray source, and the CuKβ line is removed by a nickel filter. High-purity silicon is used as the standard substance, and the calculation is performed 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: 10.0mA
Measurement method: Continuous scan axis: 2θ / θ
Sampling interval: 0.020 deg
Scan speed: 6.000 deg / min
Divergence slit: 0.50deg
Scattering slit: 0.50 deg
Light receiving slit: 0.30 mm

(2) Measurement of Toner Particle Size The average particle size and particle size distribution of the toner were measured using a Coulter Multisizer (manufactured by Beckman Coulter, Inc.), an interface (manufactured by Nikkiki) that outputs the number distribution and volume distribution, and a PC9801 personal computer (NEC). The electrolyte is prepared with about 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number distribution are measured by measuring the volume and number of toners of 2 μm or more using the Coulter Multisizer with a 100 μm aperture. And calculate.

  Then, a volume-based weight average particle diameter (D4) obtained from the volume distribution and a number-based number average particle diameter (D1) obtained from the number distribution are obtained.

(3) Toner circularity The toner circularity in the present invention is used as a simple method for quantitatively expressing the shape of toner particles. In the present invention, a flow type particle image measuring apparatus “FPIA-1000 type” is used. ”(Manufactured by Toa Medical Electronics Co., Ltd.) and measurement was performed using the following formula.
Circularity a calculated from the following formula (1)
Circularity a = L0 / L (1)
[In the formula, L0 represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. ]

Here, the same projected area as the particle image is the area of the binarized toner particle image, and the peripheral length of the particle image is defined as the length of the contour line obtained by connecting the edge points of the toner particle image. .

  The circularity in the present invention is an index indicating the degree of unevenness of the toner, and is 1.000 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity.

The average circularity a _ave, which means the average value of the circularity frequency distribution, is calculated from the following equation where the circularity (center value) at the dividing point I of the particle size distribution is a _I and the frequency is fa _i .

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “UH-50 type” (manufactured by SMT Co., Ltd.) equipped with a 5φ titanium alloy chip as a vibrator is used, and a dispersion for measurement is performed using a dispersion treatment for 5 minutes. To do. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more.

  The dispersion concentration is adjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 or more toner particles are measured. After measurement, the circularity frequency distribution of the toner is obtained using this data.

(4) Measurement of initial wear height Rpk and arithmetic average roughness Ra of developer carrying member surface Based on JIS B0601, B0671, a surf coder SE-3500 manufactured by Kosaka Laboratories was used as a measurement condition with a cutoff of 0. At 8 mm, an evaluation length of 4 mm, and a feed rate of 0.5 mm / s, each of 3 points in the axial direction × 3 points in the circumferential direction = 9 points was measured, and the average value was taken.

(5) Measurement of volume resistance of resin coating layer A coating layer having a thickness of 7 to 20 μm is formed on a PET sheet having a thickness of 100 μm, and ASTM standard (D-991-82) and Japan Rubber Association standard SRIS. It measured using the voltage drop type digital ohmmeter (made by Kawaguchi Electric Mfg. Co., Ltd.) which provided the electrode of the 4-terminal structure for volume resistance measurement of conductive rubber and plastics based on (2301-1969). The measurement environment is 20 to 25 ° C. and 50 to 60 RH%.

(6) Particle size measurement of conductive particles The particle size of conductive particles such as graphitized particles is measured using a Coulter LS-230 type particle size distribution meter (manufactured by Beckman Coulter, Inc.) of a laser diffraction type particle size distribution meter. As a measuring method, a small amount module is used, and isopropyl alcohol (IPA) is used as a measuring solvent. Wash the measurement system of the particle size distribution analyzer with IPA for about 5 minutes, and execute the background function after washing.

  Next, 1 to 25 mg of a measurement sample is added to 50 ml of IPA. The solution in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser to obtain a sample solution. The sample solution is gradually added to 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.

(7) Measurement of film thickness (scraping amount) of fat coating layer For measurement of the scraping amount (film scraping) of the coating layer, a laser dimension measuring device manufactured by KEYENCE was used. Using the controller LS-5500 and the sensor head LS-5040T, the sensor part was separately fixed to an apparatus equipped with a sleeve fixing jig and a sleeve feeding mechanism, and measurement was performed from the average value of the outer diameters of the sleeves. The measurement was divided into 30 with respect to the longitudinal direction of the sleeve and measured at 30 points. Further, after rotating the sleeve 90 ° in the circumferential direction, measurements were further made at 30 points, a total of 60 points, and the average value was taken. The outer diameter of the sleeve before application of the surface coating layer was measured in advance, the outer diameter after forming the surface coating layer and the outer diameter after durable use were measured, and the difference between them was taken as the coating film thickness and the amount of abrasion.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, a present Example does not limit this invention at all. In the examples and comparative examples, “%” and “part” are all based on mass unless otherwise specified.

<Example 1>
As raw materials for graphitized particles, heavy coal oil is heat-treated, and the resulting crude mesocarbon microbeads are centrifuged, washed with benzene, dried and then mechanically dispersed in an atomizer mill. Carbon microbeads were obtained. The mesocarbon microbeads were subjected to primary firing at 1200 ° C. in a nitrogen atmosphere and carbonized, followed by secondary dispersion in an atomizer mill, followed by secondary firing at 3000 ° C. in a nitrogen atmosphere for graphitization and further classification. As a result, graphitized particles A-1 having a volume average particle size of 3.3 μm were obtained. Table 1 shows the physical properties of the graphitized particles A-1.

Resol type phenol resin solution (containing 50% methanol) 450 parts Graphitized particles (A-1) 150 parts Methanol 150 parts Add 1 mm diameter glass beads to the above materials as media particles and disperse in a sand mill. The solid content of the dispersion was diluted to 33% with methanol to obtain a coating solution.

  Using this coating solution, a resin coating layer is formed on an aluminum cylindrical tube having an outer diameter of 16 mmφ by a spray method, and subsequently heated and cured in a hot air drying oven at 150 ° C./30 minutes to form developer carrier B-1. Produced. Table 2 shows the physical properties of the resin coating layer of the resulting developer carrier B-1.

  A polymerization toner was prepared according to the following procedure.

  To 900 g of ion-exchanged water heated to 60 ° C., 3 parts of tricalcium phosphate was added and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous medium. .

Further, the following formulation was put into a homogenizer (manufactured by Nippon Seiki Co., Ltd.), heated to 60 ° C., and then stirred at 9,000 rpm to dissolve and disperse.
Styrene 155 parts n-butyl acrylate 45 parts C.I. I. Pigment Blue 15: 3 17 parts, aluminum salicylate compound 3 parts (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
-Polyester resin 18 parts (polycondensate of propylene oxide modified bisphenol A and isophthalic acid,
Tg = 65 ° C., Mw = 10000, Mn = 6000)
-Stearyl stearate wax (DSC main peak 60 ° C) 30 parts-Divinylbenzene 0.5 parts

  In this, 5 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

  The polymerizable monomer composition was put into the aqueous medium, and granulated by stirring at 8,000 rpm using a TK homomixer at 60 ° C. in a nitrogen atmosphere.

  Then, the temperature was raised to 70 ° C. over 2 hours while stirring by transferring to a propeller type stirring device, and further 4 hours later, the temperature was raised to 80 ° C. at a rate of temperature rise of 40 ° C./Hr and reacted at 80 ° C. for 5 hours. To produce polymer particles. After completion of the polymerization reaction, the slurry containing the particles is cooled, washed with an amount of water 10 times that of the slurry, filtered and dried, and then the particle diameter is adjusted by classification to form base toner particles (weight average diameter 6.4 μm). The average circularity was 0.973).

  To 100 parts of the cyan toner base particles, 1.2 parts of silica (R812 manufactured by Aerosil Co., Ltd.) was mixed using a Henschel mixer (manufactured by Mitsui Miike Co., Ltd.) to obtain toner A of the present invention.

  The developer carrier B-1 was mounted on a commercially available laser beam printer (LBP2040 manufactured by Canon Inc.) with a modified EP83 cartridge, and evaluated for durability of 15,000 sheets while supplying the toner A. went. The elastic regulating member used was a phosphor bronze thin plate modified with a polyamide polyether elastomer having a Shore D hardness of 40 degrees by injection molding.

  Durability tests were conducted on the evaluation items listed below, and each developer carrier of Examples and Comparative Examples was evaluated.

  Image evaluation such as image density, fog, sleeve ghost, blotch, halftone uniformity, toner charge amount (Q / M) and toner transport amount (M / S) on developer carrier, and abrasion resistance of resin coating layer In terms of performance, it can be used in a 20 ° C / 60% normal temperature and normal humidity (N / N) environment, a 24 ° C / 10% normal temperature low humidity (N / L) environment, and a 30 ° C / 80% high temperature high humidity (H / H) environment. Each was evaluated for durability. The results are shown in Table 3. Good results were obtained for both image and durability.

(1) Measurement of initial wear height Rpk and arithmetic mean roughness Ra With Surfcoder SE-3500 manufactured by Kosaka Laboratory, the initial wear height Rpk and arithmetic mean roughness Ra of the developer carrier surface before the durability test were determined. It was measured. Measurements were taken for 3 points in the axial direction × 2 points in the circumferential direction = 9 points, and the average value was taken.

(2) Image density Using a reflection densitometer RD918 (manufactured by Macbeth), the density of a solid black portion when solid printing was measured was measured at five points, and the average value was used as the image density.

(3) Toner contamination on the surface of the developer carrying member (contamination resistance)
The surface of the developer carrying body after durability was evaluated under the following evaluation criteria by microscopic observation.
A: No contamination at all.
B: Although there is some contamination, there is no practical problem.
C: Level where contamination is considerably large, affects the image, and causes a practical problem.
D: Contamination and image deterioration are severe.

(4) fog The reflectance of a solid white image was measured, the reflectance of an unused transfer paper was measured, and the highest reflectance of the unused transfer paper was subtracted from the worst reflectance of the solid white image. The thing was made into fog density and evaluated as follows. The reflectance was measured with TC-6DS (manufactured by Tokyo Denshoku).
A: 1.5% or less, which can hardly be visually confirmed Level B: about 2.0 to 3.0%, which can be confirmed by careful observation C: When it exceeds 4.0%, fog is confirmed at a glance Possible level

(5) Sleeve ghost The halftone image is developed so that the position of the developing sleeve that develops the image in which the solid white portion and the solid black portion are adjacent comes to the developing position at the next rotation of the developing sleeve and develops the halftone image. The shade difference appearing above was visually evaluated based on the following criteria.
A: No difference in shading is observed.
B: A slight shading difference is observed.
C: A considerable difference in shading is observed.
D: The difference in light and shade, which is a problem in practical use, appears for one or more rounds of the sleeve.

(6) Blotch Image formation of various images such as solid black, halftone, line image, etc., image defects such as wavy unevenness and blotch (spotted unevenness) of the formed image, and development when image formation is performed The evaluation results were evaluated based on the following criteria with reference to the visual observation of toner coat defects on the sleeve.
A: Neither image nor sleeve can be confirmed at all.
B: Although it can be confirmed slightly on the sleeve, it can hardly be confirmed on the image.
C: Can be confirmed with a halftone image or a solid black image. D: An image defect that is a practical problem can be confirmed on a solid white image. .

(7) Toner charge amount (Q / M) and toner transport amount (M / S)
The 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, the collected toner mass M, and the toner are sucked through the metal cylindrical tube. From the area S, the charge amount Q / M (mC / kg) per unit mass and the toner mass M / S (dg / m ² ) per unit area are calculated, and the toner charge amount (Q / M) and toner transport are calculated respectively. Amount (M / S).

(8) Image streaks (blade scratches, fusion)
In particular, with respect to linear and belt-like streaks that occur in the halftone and run in the direction of image formation, the formed images were visually observed and evaluated according to the following criteria.
A: Neither image nor sleeve can be confirmed at all.
B: At halftone, streaks can be confirmed, but with solid black, minor levels can be confirmed.
C: Although a difference in shading can be confirmed even in a solid black image, it can be used practically.
D: The density difference which is a practical problem in the whole solid black image is conspicuous.

(9) Abrasion resistance of the resin coating layer The arithmetic average roughness (Ra) of the surface of the developer carrier before and after the durability test and the amount of abrasion of the film thickness of the resin coating layer were measured.

  For measurement of the amount of abrasion (film abrasion) of the resin coating layer, a laser dimension measuring device manufactured by KEYENCE was used. Using the controller LS-5500 and the sensor head LS-5040T, the sensor part was separately fixed to an apparatus equipped with a sleeve fixing jig and a sleeve feeding mechanism, and measurement was performed from the average value of the outer diameters of the sleeves. The measurement was divided into 30 with respect to the longitudinal direction of the sleeve and measured at 30 points. Further, after rotating the sleeve 90 ° in the circumferential direction, measurements were further made at 30 points, a total of 60 points, and the average value was taken. The outer diameter of the sleeve before application of the surface coating layer was measured in advance, the outer diameter after forming the surface coating layer and the outer diameter after durable use were measured, and the difference between them was taken as the coating film thickness and the amount of abrasion.

<Examples 2 and 3>
Graphitized particles A-2 and A-3 were obtained using the same method except that the classification conditions of the graphitized particles A-1 used in Example 1 were changed. Table 1 shows the physical properties of the obtained graphitized particles A-2 and A-3. The developer carrier B- was used in the same manner as in Example 1 except that these graphitized particles A-2 and A-3 were used as graphitized particles in the resin coating layer instead of the graphitized particles A-1. 2 and B-3 were prepared and evaluated in the same manner as in Example 1. Table 2 shows the physical properties of the resin coating layer of the developer carrier, and Table 3 shows the evaluation results.

<Examples 4 and 5>
Graphitized particles A-4 and A-5 were obtained using the same method except that the secondary firing temperature of graphitized particles A-1 used in Example 1 was changed. Table 1 shows the physical properties of the obtained graphitized particles A-4 and A-5. The developer carrier B- was used in the same manner as in Example 1 except that these graphitized particles A-4 and A-5 were used as graphitized particles in the resin coating layer instead of the graphitized particles A-1. 4 and B-5 were prepared and evaluated in the same manner as in Example 1. Table 2 shows the physical properties of the resin coating layer of the developer carrier, and Table 3 shows the evaluation results.

<Example 5>
In Example 1, a developer carrier B-5 was produced in the same manner as in Example 1 except that graphitized particles A-5 using bulk mesophase pitch particles as raw materials were used instead of graphitized particles A-1. Then, the same evaluation as in Example 1 was performed. Table 1 shows the physical properties of the graphitized particles A-5. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 3 shows the evaluation results.

<Examples 6 and 7>
Graphitized particles A-6 and A-7 were obtained using the same method except that the secondary firing temperature of the graphitized particles A-5 used in Example 1 was changed. Table 1 shows the physical properties of the obtained graphitized particles A-6 and A-7. The developer carrier B- was used in the same manner as in Example 1 except that these graphitized particles A-6 and A-7 were used as graphitized particles in the resin coating layer instead of the graphitized particles A-5. 6, B-7 were produced and evaluated in the same manner as in Example 1. Table 2 shows the physical properties of the resin coating layer of the developer carrier, and Table 3 shows the evaluation results.

<Examples 7 and 8>
Graphitized particles A-4 are graphitized particles A-7 and A-8 using the same method except that the pulverization conditions of the bulk mesophase pitch of the raw materials used and the classification conditions after secondary firing were changed. Obtained. Table 1 shows the physical properties of the obtained graphitized particles A-7 and A-8. Developer carrying bodies B-7 and B-8 were prepared in the same manner as in Example 1 except that the graphitized particles A-7 and A-8 were used instead of the graphitized particles A-1, and the same evaluation was performed. Went. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 3 shows the evaluation results.

<Example 9>
Resol type phenol resin solution (containing 50% methanol) 450 parts Graphitized particles (A-1) 150 parts Quaternary ammonium salt compound of the following formula (1) 30 parts Methanol 150 parts

（式（１）の第４級アンモニム塩化合物１について、鉄粉との摩擦帯電量を摩擦帯電量測定器ＴＢ−２００型（東芝ケミカル製）を用いてブローオフ法により測定したところ、正極性であった。）

(For the quaternary ammonium salt compound 1 of the formula (1), the triboelectric charge amount with the iron powder was measured by a blow-off method using a triboelectric charge meter TB-200 type (manufactured by Toshiba Chemical). there were.)

  Glass beads having a diameter of 1 mm were added as media particles to the above material, dispersed with a sand mill, and the solid content of the dispersion was diluted to 30% with methanol to obtain a coating solution.

  Using this coating solution, a resin coating layer was formed on an aluminum cylindrical tube having an outer diameter of 16 mmφ by a spray method in the same manner as in Example 1, and then heated and cured in a hot air drying furnace at 150 ° C. for 30 minutes. Developer carrier B-9 was produced. Table 2 shows the physical properties of the resin coating layer of the resulting developer carrier B-9. Using toner A, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 3.

<Examples 10 and 11>
Developer carrying bodies B-10 and B-11 were obtained in the same manner except that graphitized particles A-4 and A-5 were used instead of the graphitized particles A-1 used in Example 9. Table 2 shows the physical properties of the resin coating layers of the obtained developer carriers B-10 and B-10. Using toner A, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 3.
Resol type phenol resin solution (containing 50% methanol) 450 parts Graphitized particles (A-4 or A-5) 150 parts Quaternary ammonium salt compound of formula (1) 30 parts Methanol 150 parts

<Example 12>
Developer carrier B-12 was produced in the same manner except that the quaternary ammonium salt compound of the following formula (2) was used instead of the quaternary ammonium salt compound of the formula (1) in Example 9. Table 2 shows the physical properties of the resin coating layer of the resulting developer carrier B-12. Using toner A, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 3.

（鉄粉との摩擦帯電量を測定したところ、正極性であった。）

(When the triboelectric charge with the iron powder was measured, it was positive.)

<Example 13>
A developer carrier B-13 was prepared in the same manner as in Example 1 except that the coating material made of the following material was used instead of the phenol resin used in Example 1, and toner A was used in the same manner as in Example 1. evaluated. Table 2 shows the physical properties of the resin coating layer, and Table 3 shows the evaluation results.
Urethane resin (solid content 50%) 450 parts Graphitized particles (A-1) 150 parts Quaternary ammonium salt compound of formula (1) 30 parts Methanol 150 parts

<Comparative example 1>
As a raw material for graphitized particles, a mixture of coke and tar pitch is used, and the mixture is kneaded at a temperature equal to or higher than the softening point of tar pitch, extruded, and subjected to primary firing at 1000 ° C. in a nitrogen atmosphere to be carbonized. Subsequently, after impregnating with coal tar pitch, it was graphitized by secondary firing at 2800 ° C. in a nitrogen atmosphere, and further pulverized and classified to obtain graphitized particles a-1 having a number average particle size of 7.5 μm. Table 1 shows the physical properties of the graphitized particles a-1.

  In Example 1, a developer carrier b-1 was prepared and evaluated in the same manner except that the graphitized particle a-1 was used instead of the graphitized particle A-1. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative example 2>
Spherical phenol resin particles were used as raw materials for graphitized particles, fired at 2200 ° C. in a nitrogen atmosphere, and further classified to obtain graphitized particles a-2 having a number average particle size of 6.2 μm. Table 1 shows the physical properties of the graphitized particles a-2. In Example 1, a developer carrier b-2 was produced and evaluated in the same manner as in Example 1 except that graphitized particles a-2 were used instead of graphitized particles A-1. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 3>
Graphitized particles a-3 were obtained in the same manner as the graphitized particles A-1, except that the secondary firing temperature was changed. Table 1 shows the physical properties of the obtained graphitized particles a-3. A developer carrier b-3 was produced in the same manner as in Example 1 except that this graphitized particle a-3 was used instead of the graphitized particle A-1 in Example 1, and the same evaluation was performed. went. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Examples 4 and 5>
With graphitized particles A-1, the classification conditions of graphitized particles a-3 obtained by changing the secondary firing temperature were changed to obtain graphitized particles a-4 and a-5. Table 1 shows the physical properties of the obtained graphitized particles a-4 and a-5. The developer-carrying bodies b-4 and b- are the same as in Example 1 except that these graphitized particles a-4 and a-5 are used in place of the graphitized particles A-1 in Example 1. 5 was produced and the same evaluation was performed. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 6>
A developer carrier b-6 was prepared and evaluated in the same manner as in Example 1 except that the graphitized particles A-1 used in Example 1 were replaced with graphitized particles a-6 produced from a mixture of coke and tar pitch. Went. Table 1 shows the physical properties of the obtained graphitized particles a-6. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 7>
Graphitized particles a-7 were obtained in the same manner as graphitized particles A-6 except that the secondary firing temperature was changed. Table 1 shows the physical properties of the obtained graphitized particles a-7. A developer carrier b-7 was produced in the same manner as in Example 1 except that this graphitized particle a-7 was used instead of the graphitized particle A-1 in Example 1, and the same evaluation was performed. went. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 8>
Graphitized particles a-7 obtained by changing the secondary firing temperature of graphitized particles A-6 were classified to obtain graphitized particles a-8. Table 1 shows the physical properties of the obtained graphitized particles a-8. A developer carrier b-8 was produced in the same manner as in Example 1 except that this graphitized particle a-8 was used instead of the graphitized particle A-1 in Example 1, and the same evaluation was performed. went. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 9>
The classification conditions of graphitized particle a-2 were changed to obtain graphitized particle a-9. Table 1 shows the physical properties of the obtained graphitized particles a-9. A developer carrier b-9 was produced in the same manner as in Example 1 except that this graphitized particle a-9 was used instead of the graphitized particle A-1 in Example 1, and the same evaluation was performed. went. Table 2 shows the physical properties of the resin coating layer of this developer carrier, and Table 4 shows the evaluation results.

<Comparative Example 10>
Using the coating liquid used in Example 2, the coating conditions for forming the resin coating layer by a spray method were changed to obtain developer carrier b-10. Table 2 shows the physical properties of the resin coating layer of the developer carrier b-10. Using these, evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 4.

<Comparative Examples 11 and 12>
The dispersion conditions (dispersion time) when preparing the coating liquid using the graphitized particles A-3 in Example 3 were changed, and developer carriers b-11 and b-12 were obtained by a spray method. Table 2 shows the physical properties of the resin coating layers of the developer carriers b-11 and b-12. Using these, evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 4.

FIG. 3 is a schematic cross-sectional view showing a part of the developer carrier of the present invention. FIG. 3 is a schematic cross-sectional view showing a part of the developer carrier of the present invention. 1 is a schematic configuration diagram illustrating an embodiment of a developing device of the present invention. It is a structure schematic diagram which shows the other embodiment of the image development apparatus of this invention. It is a structure schematic diagram which shows the other embodiment of the image development apparatus of this invention. It is explanatory drawing of initial wear height Rpk.

Explanation of symbols

a graphitized particles b coating resin c conductive fine particles 1 electrophotographic photosensitive drum 2 hopper 3 developer 4 magnet roller 5 metal cylindrical tube (substrate)
6 Resin coating layer 7 Development sleeve 8 Power supply 9 Stirring blade 10 Developer layer thickness regulating member 11 Gap 12 Developer supply / stripping member

Claims (11)

A developer carrier for carrying a one-component developer for visualizing an electrostatic latent image carried on an electrostatic latent image carrier, wherein the developer carrier is formed on at least a substrate and the surface of the substrate The resin coating layer contains at least a resin and graphitized particles, and the graphitized particles have a graphitization degree p (002) of 0.20 ≦ p (002) ≦ 0. 95, and an initial wear height Rpk on the surface of the resin coating layer is 0.2 to 1.0 μm. 2. The developer carrying member according to claim 1, wherein the graphitized particles are obtained by graphitizing mesocarbon microbead particles. 2. The developer carrier according to claim 1, wherein the graphitized particles are obtained by graphitizing bulk mesophase pitch particles. 4. The developer carrying member according to claim 1, wherein the resin coating layer contains a quaternary ammonium salt compound that is positively charged with respect to iron powder. The resin coating layer contains at least a phenol resin, and the phenol resin is a phenol resin produced by using a nitrogen-containing compound as a catalyst, and the structure includes —NH ₂ group, ═NH group, or — The developer carrying member according to claim 4, which is a phenol resin having any of NH-bonds. A developer container that contains a one-component developer; and a developer carrier that carries the developer contained in the developer container; and the developer container is carried on the development area facing the electrostatic latent image carrier. In the developing method for transporting the developed developer and developing and visualizing the electrostatic latent image carried on the electrostatic latent image carrier by the carried developer,
The developer carrier has at least a substrate and a resin coating layer formed on the surface of the substrate, the resin coating layer contains at least a resin and graphitized particles, and the graphitized particles have a graphitization degree. p (002) is 0.20 ≦ p (002) ≦ 0.95, and initial wear height Rpk of the resin coating layer surface is 0.2 to 1.0 μm. . The developing method according to claim 6, wherein the graphitized particles are obtained by graphitizing mesocarbon microbead particles. The developing method according to claim 6, wherein the graphitized particles are obtained by graphitizing bulk mesophase pitch particles. The developer carrier has at least a substrate and a resin coating layer, and the resin coating layer contains a quaternary ammonium salt compound that is positively charged at least with respect to iron powder. Item 9. The developing method according to any one of Items 6 to 8. The resin coating layer contains at least a phenol resin, and the phenol resin is a phenol resin produced by using a nitrogen-containing compound as a catalyst, and the structure includes —NH ₂ group, ═NH group, or — The developing method according to claim 9, which is a phenol resin having any of NH-bonds. 3. The developer according to claim 1, wherein the developer is a non-magnetic one-component developer, and the non-magnetic one-component developer has an average circularity of 0.970 or more obtained from the following formulas (1) and (2). The developing method according to any one of 6 to 10.
Circularity a = L0 / L (1)
[In the formula, L0 represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. ]

[ _Where a _ave is the average circularity, the circularity (center value) at the dividing point I of the particle size distribution is a _I , and the frequency is fa _i . ]

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