JP2007147734A - Developing method and developer carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier and a developing method which are capable of stably obtaining an image of high density and high quality without bringing about problems such as the reduction in image density, image density unevenness, image stripes, sleeve ghost, and blotches due to charge-up of developer and unevenness and instability of triboelectric charges, which accompany a condition of initial development. <P>SOLUTION: With respect to the developer carrier, a resin layer which will be worn out by use is formed on a part or the whole of a conductive coating layer provided on a cylindrical substrate, and carrier particles are uniformly carried on the resin layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer used in an image forming apparatus for developing and developing an electrostatic latent image formed on an electrostatic image bearing member such as an electrophotographic photosensitive member or an electrostatic recording derivative with a developer. The present invention relates to a carrier and an image forming method using the developer carrier.

  Conventionally, many methods are known as electrophotographic methods. Generally, a photoconductive material is used to form an electrostatic latent image on an electrostatic latent image carrier (photosensitive drum) by various means. Then, the electrostatic latent image is developed with a developer (toner) to be visualized, and the toner image is transferred to a recording material such as paper as necessary, and then the toner is applied onto the recording material by heat, pressure, or the like. Fix the image to get a copy.

  The development method in electrophotography is mainly divided into a one-component development method and a two-component development method. If it is necessary to reduce the size of the copying apparatus for the purpose of reducing the weight and size of the electrophotographic apparatus, the one-component development method is used. The used developing device is often used. The one-component development method does not require the use of carrier particles such as iron powder unlike the two-component development method, so that the developing 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, a device for detecting the toner concentration and supplying a necessary amount of toner is required. Therefore, the developing device is also large and heavy here. The one-component development method is preferable because such an apparatus is not necessary and can be made small and light.

  As a developing device using the one-component developing method, a device as shown in FIG. 5 is known.

  In the developing device, a developer carrying member (developing sleeve) 8 is provided at an opening of a container 3 that accommodates the developer 4, and the developer carrying member 8 is uniformly coated with the developer 4 and the developer carrying member 8. In addition, a developer layer thickness regulating member (elastic blade) 11 that frictionally charges (trebo) the developer 4 is provided. Here, the developer 4 is a magnetic one-component toner. Therefore, the developer carrying member 8 comprises at least a cylindrical base 6 made of a nonmagnetic metal such as aluminum and a conductive coating layer 7 provided thereon. A multipolar magnet (magnet roller) 5 is inserted into the developer carrier 8. On the other hand, a stirring blade 10 for stirring the developer 4 and sending it to the developer carrier 8 is provided in the developer storage container 3.

  In this figure, the developer layer thickness regulating member 11 is made of an elastic member and is in contact with the developer carrier 8. However, the developer 4 is magnetically coupled to the multipolar magnet 5. In some cases, the metal magnetic blade 2 may be restricted (see FIG. 6).

  When the developer is a non-magnetic one-component developer, the base 6 of the developer carrier 8 does not have to be cylindrical (sleeve shape), and may be cylindrical. In this case, since at least the surface needs to be conductive, it is usually made of metal, and the developer 4 that has returned to the developer remaining on the developer carrier 8 is scraped off and newly developed. A developer supply member (elastic roller) 13 for feeding the agent 4 onto the developer carrier 8 is provided in contact with the developer carrier 8 at the upper position of the elastic blade 11 in the developer container 3. (See FIG. 7).

  In the electrophotographic apparatus, the developing device is placed so that the developer carrier 8 is set against the photosensitive drum 1. Further, when the electrostatic latent image on the photosensitive drum 1 is visualized (developed), it is controlled that the developer 4 is transferred (flyed / attached) from the surface of the developer carrier 8 to the electrostatic latent image. For this purpose, a power source 9 for applying a bias voltage to the developer carrier 8 is provided.

  In the one-component development method, the electrostatic latent image formed on the surface of the photosensitive drum 1 is moved to the developing region D where the developer carrying member 8 and the photosensitive drum 1 face each other by rotating the photosensitive drum 1 in the direction of arrow B. On the other hand, the positively or negatively charged toner 4 is thinly carried on the developer carrier 8 due to friction with the developer carrier 8 and the elastic blade 11 and the like, and in the development area D, an electrostatic latent image is formed. The electrostatic latent image that has moved by flying and adhering is successively visualized and visualized as a toner image, that is, developed.

  When such a one-component development system is used, it is difficult to adjust the triboelectric charge amount of the toner, and various attempts have been made to improve the toner composition and physical properties. Problems related to sustainability have not been completely solved. In particular, while the developer carrier is repeatedly rotated, the toner carried on the developer carrier becomes too charged, and the surface of the developer carrier and the electrostatic attractive force (mirror force) The so-called charge-up phenomenon that is attracted to the surface of the developer carrying member and becomes immobile on the surface of the developer carrying member and does not move to the electrostatic latent image is likely to occur particularly under low humidity. When such a charge-up phenomenon occurs, the toner on the surface layer portion of the toner layer carried on the surface of the developer carrying member becomes only the friction between the toners substantially, so that it becomes difficult to be charged and the toner is developed (moved). The amount is reduced, causing problems such as thin line images and insufficient density of solid images.

  In addition, toner that is not properly charged due to the charge-up phenomenon becomes poorly regulated, flows out of the surface of the developer carrying member to the surface of the photosensitive drum, and is observed as spotted or wavy unevenness on the fixed image, so-called blotch. The phenomenon occurs.

  Further, the toner layer carried on the surface of the developer carrying member has different formation states between a portion where the toner is consumed for development (image portion) and a portion where the toner is hardly consumed (non-image portion). In addition, the charged state of the toner is different. For this reason, for example, when the position where a solid image having a high image density is once developed on the developer carrying member comes to the developing position at the next rotation of the developer carrying member and the halftone image is developed, a solid image is formed on the image. A so-called sleeve ghost phenomenon is also likely to occur, in which a trace of developing the toner appears.

  As a method for solving such a phenomenon, it has been proposed to use a developer carrier in which a conductive coating layer in which conductive fine powders such as crystalline graphite and conductive carbon are dispersed in a resin is provided on a metal substrate. (For example, Patent Documents 1 and 2).

  By using this method, it is recognized that the above phenomenon is greatly reduced. However, in this method, a large amount of conductive fine powder is added to the conductive resin layer, which is good for preventing the occurrence of charge-up and sleeve ghosting, but is insufficient in charging the toner, It is difficult to obtain a sufficient image density in a high temperature and high humidity environment. In addition, the conductive coating layer to which a large amount of conductive fine powder is added becomes brittle and easy to scrape, and the surface shape tends to be non-uniform, and the surface roughness and surface composition of the coating layer change with long-term use, Toner conveyance failure and non-uniform charge application to the toner are likely to occur. On the other hand, when there is little addition of the conductive fine powder to the conductive coating layer, the effect of adding the conductive fine powder is poor, and there remains a problem that measures against charge-up and sleeve ghost are insufficient.

  In order to solve these problems, in addition to conductive fine powders such as crystalline graphite and carbon, a developer carrying layer in which a conductive coating layer made of a resin composition in which spherical particles are dispersed is provided on a metal substrate. A body has been proposed (for example, Patent Document 3).

  This developer carrier improves the wear resistance of the conductive coating layer, makes the surface of the conductive coating layer uniform, and has relatively little change in surface roughness due to long-term use. The toner is stably carried on the toner, and the toner is uniformly charged. For this reason, there are no problems such as sleeve ghost, image density, and image density unevenness, and the image quality is stabilized. However, even with this developer carrier, the stability of quick and uniform charge controllability to the toner and appropriate charge imparting ability to the toner is insufficient.

  Furthermore, a developer carrier having a conductive coating layer in which the spherical particles have a low specific gravity and conductivity has been proposed (for example, Patent Document 4).

  By using such spherical particles, it is possible to uniformly disperse the conductive spherical particles in the conductive coating layer, thereby making the wear resistance and surface shape of the conductive coating layer uniform and uniform to the toner. The charge imparting property is improved, and toner contamination and toner fusion are suppressed even if the conductive coating layer is somewhat worn. However, this developer carrier is not perfect in terms of quick and uniform charge imparting property to the toner and moderate charge imparting capability to the toner.

  In order to carry the above-mentioned one-component developing type toner thinly on the developer carrying member, the elastic blade is usually brought into contact with the developer carrying member in the counter direction with respect to the rotation direction of the developer carrying member, and the elastic blade and the developing member are developed. A method is adopted in which the toner carrying amount on the surface of the developer carrying member is regulated by the contact pressure of the developer carrying member and the contact portion (nip portion) between the elastic blade and the developer carrying member. For this reason, as the elastic blade, a hard material such as a support member made of a metal or a hard synthetic resin and having an elastic body such as silicon rubber or urethane rubber fixed thereto is often used.

  In such an apparatus having a configuration in which the elastic blade is in contact with the developer carrying member, when the toner seal is not opened, that is, the toner is sealed in the storage container, and there is no toner on the developer carrying member. In this state, since the elastic blade is in direct contact with the surface of the developer carrier, sticking is caused by the contact pressure, and if the developer carrier is rotated as it is, the elastic blade is turned over or elastic A sticking scar may be generated on the blade and / or the developer carrying member, resulting in a problem that the toner cannot be uniformly applied onto the surface of the developer carrying member. In order to prevent these, a method of applying a powder lubricant dispersed in a volatile liquid on the elastic blade surface is used (for example, Patent Document 5).

  Such a lubricant is easily charged by friction with a developer carrying member, an elastic blade, etc., similarly to the case where the toner is frictionally charged, and depending on the charge series and chargeability, the charge of the toner is affected. There is a case. In particular, since the lubricant is adhered on the surface of the developer carrying member at the initial stage when the apparatus is operated, the influence becomes remarkable.

  If the charge polarity of the lubricant to the iron powder is opposite to that in the toner, if the charge series distance between the two is large, the lubricant will also become a charge imparting member, and the toner will be extremely charged, and the toner will carry the developer. It attracts by the mirror surface force and becomes immobile on the surface of the developer carrying member, and does not move from the developer carrying member to the latent image on the photosensitive drum.

  When such a charge-up phenomenon occurs, the toner on the surface layer of the toner carried on the surface of the developer carrying member tends to be non-uniformly charged, and sleeve ghost is likely to occur on the image. Further, since the toner development amount is reduced, problems such as thin line images, uneven solid images, and low image density occur.

  Furthermore, toner particles that are not sufficiently charged due to charge-up become poorly regulated and flow out of the developer carrying member onto the surface of the photosensitive drum, causing a phenomenon in which spotted or wavy irregularities appear in the fixed image, so-called blotch phenomenon.

  On the other hand, if the lubricant has the same charge polarity with respect to the iron powder as the toner, and easily retains the charge, the triboelectric charge is not sufficiently applied to the toner, and the toner charge is also likely to be uneven, and the image density Unevenness and thin image density may occur.

  Therefore, as a lubricant, in the initial stage of operation of the apparatus until the toner is sufficiently carried on the surface of the developer carrier, the development characteristics vary and the lubricant is non-uniformly transferred onto the surface of the developer carrier. Therefore, it is necessary to use a lubricant having an appropriate shape, charging characteristics and the like so as not to cause image defects due to the above.

  For this reason, non-uniform toner charging is achieved by using a lubricant that has an average particle size and circularity defined as a lubricant and that is configured so that the chargeability of the lubricant itself can be set within an appropriate range. A developing device that can reduce image quality and charge-up and prevent image defects such as sleeve ghost has been proposed (for example, Patent Document 6).

  On the other hand, LED and LBP printers are the mainstream in the recent market as printer devices, and the direction of technology is higher resolution, that is, the conventional 300 dpi, 400 dpi has become 600 dpi, 800 dpi, 1200 dpi. . Along with this, a higher-definition development method has been demanded.

  Also, copying machines are becoming more sophisticated, and therefore are moving toward digitalization. In such a trend, digital copying machines mainly use a method of forming an electrostatic latent image with a laser beam, and are also proceeding in the direction of high resolution. Here, as with printers, high resolution and high definition are also achieved. A developing method is required, and therefore, the toner has a small particle size and fine particles.

  Such a toner having a small particle size has a large surface area per unit mass, so that the charge amount tends to be excessive in frictional charging, and image defects such as sleeve ghost and density unevenness due to a charge-up phenomenon tend to occur.

  Further, in terms of energy saving and space saving in offices, printers and copier bodies are required to be smaller. At that time, the container for storing the toner inevitably needs to be downsized, and a low consumption toner that can print a large number of sheets with a small amount, that is, can cover the same image with a smaller amount of toner. It has been demanded.

  As such a toner, a toner whose shape is made closer to a sphere by a manufacturing method such as a method of spheroidizing the toner itself by a mechanical impact force, a spray granulation method, a solution dissolution method, or a polymerization method has been used.

  Such a spherical toner has a smoother surface than the pulverized toner. In particular, since the magnetic one-component developer contains a magnetic material, frictional charging tends to become unstable. Also here, image defects such as the above-mentioned sleeve ghost, blotch phenomenon, density unevenness and the like tend to occur.

  In order to suppress this tendency, a quaternary ammonium salt compound having a positive charge polarity with respect to the iron powder is added, and excessive charging such as charge-up is applied to the spheroidized toner or the negative toner produced by the polymerization method. A method using a developer carrying member for preventing it has been proposed (for example, Patent Document 7, Patent Document 8, etc.).

  When such a method is used, the effect of preventing the charge-up phenomenon in durability and improving the charging uniformity is recognized. However, since the lubricant affects the triboelectric charging of the developer, it is difficult to completely solve the problem.

  In this way, as the particle size and spheroidization of the toner progresses to improve the performance of the electrophotographic apparatus, the charging of the toner tends to become unstable and non-uniform, and this tendency has a large amount of lubricant. This is noticeable in the early stage of image output.

  In the above prior art, such a charged state of the initial toner can be controlled to some extent, but no system that can be satisfied in any environment or development system has been found.

Accordingly, there is a demand for further prevention of charge-up phenomenon, improvement of charging uniformity, and improvement of image defects such as sleeve ghost phenomenon and density unevenness caused by them.
Japanese Patent Laid-Open No. 2-105181 JP-A-3-36570 Japanese Patent Laid-Open No. 3-200986 JP-A-8-240981 JP-A-2-298971 JP 11-119551 A JP 2003-57951 A JP 2002-311636 A

  That is, the problem of the present invention is to charge up the developer that occurs in the initial stage of image output, uneven frictional charging, image density reduction that occurs due to instability, image density unevenness, image streak, An object of the present invention is to provide a developer carrying member and a developing method capable of stably obtaining a high-quality image having a high image density without causing problems such as sleeve ghost and blotch.

  The present inventors have intensively studied in order to pass the above-mentioned problems, and in a developer carrier having a conductive coating layer, a resin layer formed of a resin composition different from the conductive coating layer and worn according to use. Further, particles having the same charging polarity with respect to the resin layer and the iron powder are used as particles for preventing the adhesion between the developer carrying member and the elastic blade. This prevents the occurrence of image defects due to developer charge-up, which is likely to occur especially in the early stage of image output, and can form a good image from the beginning, and also in repeated use and durable use The present invention has been completed by finding that a good and stable image can be obtained.

  That is, the present invention is as follows.

(1) A developer carrying member provided with at least a conductive coating layer on a substrate, wherein the developer layer is further partially or entirely formed on the conductive coating layer and is worn by use. Carrier.

(2) The developer carrying member according to the above (1), wherein the resin layer has a hardness (pencil hardness) of H or less.

(3) The developer carrier of the above (1) and (2), wherein the resin layer is conductive.

(4) The developer carrier of the above (1) to (3), wherein the resin layer is further coated with fine particles having the same charging polarity with respect to the iron powder as the resin layer.

(5) Image information is formed as an electrostatic latent image on the electrostatic image bearing member, a magnetic one-component developer is supplied to the formed electrostatic latent image by a developer bearing member, and the electrostatic latent image is developed. An image forming method in which a developer image is visualized, and then the developer image is transferred onto a recording material, and the developer is melted and solidified to fix the image on the recording material. A conductive coating layer is provided on the conductive coating layer, and a resin layer that is worn by use is partially or entirely formed on the conductive coating layer, and at least the surface of the developer carrier and / or the developer. An image forming method, wherein fine particles having a charge polarity with respect to iron powder that is the same as that of a resin layer are supported on a contact surface of a layer thickness regulating member with a developer carrier.

(6) The image forming method according to (5), wherein the resin layer has a hardness (pencil hardness) of H or less.

(7) The image forming method according to the above (5) or (6), wherein the resin layer is conductive.

(8) The image forming method according to the above (5) to (7), wherein fine particles having the same charging polarity with respect to the iron powder as the resin layer are supported on the surface of the developer bearing member.

  According to the developer carrying member of the present invention, as the image formation proceeds, the resin layer disappears from the conductive coating layer due to wear. A stable and high-quality image can be obtained from the beginning without being excessively charged by the layer.

  In addition, according to the present invention, it is possible to further suppress excessive charging to the toner at the initial stage of image formation by making the fine particles supported on the resin layer and the surface have the same polarity as the chargeability to the iron powder. It is possible to provide an image free from problems such as image density reduction due to charge-up, uneven image density due to non-uniform charge distribution, and sleeve ghost.

  In the developer carrying member of the present invention, a conductive coating layer formed of a resin containing conductive fine particles is formed on a substrate whose surface is conductive at least, and a part or the whole of the surface is covered on the surface. A resin layer made of a resin composition different from the conductive coating layer, which is scraped off (worn) while in use, is formed.

  This developer carrier is basically the same as a conventional developer carrier comprising a substrate and a conductive coating layer, but further has a resin layer that is worn by use. This prevents problems caused by fine particles, charge-up, sleeve ghost, etc., that the agent carrier has to prevent sticking to the elastic blade at the start.

  The structure of the developer carrying member of the present invention will be described with reference to FIG.

  FIGS. 1A and 1B are schematic cross-sectional views showing an example of the basic configuration of the developer carrier of the present invention.

  In FIG. 1, a developer carrier (developing sleeve) 300 includes a metal cylindrical tube (base) 302, a conductive coating layer 304 mainly covering a surface of the cylindrical tube 302, and a binder resin 309, and the conductive layer. It consists of a resin layer 312 covering the surface of the coating layer 304, and in a preferred form of use, it is composed of supported particles 310 supported on the surface. In the conductive coating layer 304, a conductive agent 308, unevenness imparting particles 306, and a solid lubricant 307 are dispersed in a binder resin 309.

  1A, the resin layer 312 is present on the entire surface of the conductive coating layer 304. In FIG. 1B, the resin layer 312 is present on a part of the surface of the conductive coating layer 304. Show.

  Since the resin layer 312 disappears as the number of printed images (image formation) is increased (used), the resin layer may be thin, or may be unevenly distributed as shown in FIG.

  FIG. 2 is a partial cross-sectional view showing an example of a basic configuration when the developer carrying member of the present invention is incorporated in an image forming apparatus and toner is supplied.

  In FIG. 2, as the developer layer thickness regulating member (elastic blade) 301 in contact with the developing sleeve 300, an elastic member such as urethane rubber is used.

  The developing sleeve 300 includes a conductive coating layer 304 made of a binder resin 309 in which a substrate 302, a conductive agent 308, unevenness-imparting particles 306 and a solid lubricant 307 are dispersed, and a resin layer 312 covering the entire surface or a part of the conductive coating layer. The carrier particles 310 are carried on the surface of the developing sleeve 300. Further, the carrier particles 310 are also carried on the contact surface of the elastic blade 301 with the developing sleeve 300.

  The supported particles 310 may be supported on the entire surface of the developing sleeve 300 in advance, or may be supported at a high concentration on the contact portion of the elastic blade 301 with the developing sleeve 300. In the case where the carrier particles 310 are carried at a high concentration on the elastic blade 301, the developing sleeve 300 is rotated before the toner is supplied after the elastic blade 301 or the like is incorporated (before image use or before image formation). The carrier particles 310 are uniformly applied to the surface of the developing sleeve 300.

  Since toner does not exist on the developing sleeve before use for image output, the carrier particles 310 are also attached to the developer regulating member 301 at a portion where the developing sleeve 300 and the developer layer thickness regulating member 301 are in contact with each other. . For this reason, the developing sleeve 300 and the elastic blade 301 are not in direct contact with each other even before image formation where no toner is carried on the surface of the developing sleeve 300, and the developing sleeve 300 is prevented from sticking to the elastic blade 301 and being damaged. Is done.

  In the initial stage of image formation (image formation), there are many opportunities for contact between the surface of the developing sleeve 300 and the carrier particles 310, and depending on the selection of the material, charging of the carrier particles may occur. By making the resin layer 312 and the support particles 310 present in the same charge polarity with respect to the iron powder, the resin layer 312 and the support particles 310 do not have an excessive charge.

  The triboelectric charge held by the toner 311 is controlled so as to be appropriate, and the charge-up phenomenon can be alleviated. As a result, image defects such as sleeve ghost and blotch can be eliminated.

  As the number of images to be printed increases, the carrier particles 310 are consumed together with the toner 311, and the amount of the carrier particles 310 on the developing sleeve 300 decreases.

  Further, the resin layer 312 is scraped by the developer 311 and the carrier particles 310 and disappears (wears).

  However, since the conductive coating layer 304 exists as it is, a good charged state of the toner 311 is maintained, and the toner 311 is not charged insufficiently or charged up. Formation can be achieved.

  In the following, “charging polarity” means the charging polarity as measured with respect to iron powder unless otherwise specified. That is, when the object to be rubbed is rubbed with iron powder, the charging polarity is “negative” (also referred to as “negative chargeability”) when it is negatively charged. Conversely, when the object to be rubbed is positively charged, the charging polarity is It is said to be “positive” (also referred to as “positive charging”). In the following, it may be simply referred to as “negative chargeability” or “positive chargeability”.

  The configuration of the developer carrying member used in the present invention will be described in more detail.

  As the base of the developer carrying member, there are a cylindrical member, a columnar member, a belt-like member and the like, but in a developing method which is not in contact with the drum, a rigid cylindrical tube or a solid rod such as metal is preferable.

  As such a substrate, a non-magnetic metal or alloy such as aluminum, stainless steel, brass or the like formed into a cylindrical shape or a cylindrical shape, and then subjected to polishing, grinding, or the like is preferably used. Aluminum is preferable from the viewpoint of material cost and ease of processing. When the developer is a non-magnetic one-component system, it may be made of a magnetic metal such as iron.

  These substrates are desirably molded or processed with high precision in order to improve image uniformity.

  For example, the straightness in the longitudinal direction is suitably 30 μm or less, preferably 20 μm or less, more preferably 10 μm or less, and the gap between the developer carrying member and the photosensitive drum, for example, through a uniform spacer with respect to the vertical surface. When the developer carrying member is rotated, the fluctuation of the gap with the vertical surface is also 30 μm or less, preferably 20 μm or less, more preferably 10 μm or less.

  Further, the surface of the substrate may be provided with unevenness by processing with a sandpaper or a blast material in order to improve the developer transportability.

  Note that the blasting apparatus shown in FIG. 3 can be preferably used to provide unevenness on the surface of the substrate with a blasting material. That is, the base body 108 to which the masking jig 107 is attached at both ends is placed on the rotary base 100 vertically and is rotated in the direction of the arrow on the base 100. On the other hand, the blast nozzle 101 is held by a nozzle holder 102. The nozzle holder 102 is fixed to a fixing base 110 with fixing screws 105, and the fixing base 110 is attached to a pole screw 109. The rotation of the pole screw 109 causes the fixing base 110 to move up and down, and the blast nozzle 101 moves up and down together with the fixing base 110.

  A gas flow path 103 and a blast material flow path 104 for injecting a blast material are connected to the blast nozzle 101, and the blast material 106 passes through the blast material flow path 104 when gas is introduced into the gas flow path 103. After that, it is ejected from the tip of the blast nozzle 101.

  The blast material 106 sprayed from the blast nozzle 101 gives unevenness to the formation region of the conductive coating layer of the base 108 rotating on the rotary base 100. The degree of unevenness is appropriately set according to the material and particle size of the blasting material 106 to be used, the material and diameter of the base material 108, the flow rate of gas and the amount used for the blasting material, the rotational speed of the base material 108, the moving speed of the blast nozzle 101, etc. it can.

  In the present invention, a conductive coating layer is further provided on the substrate surface. The conductive coating layer may be a resin coating layer formed by arranging a conductive agent, irregularities-providing particles, a solid lubricant, etc. in a binder resin as shown in FIGS. A plating layer formed by plating a conductive metal on the surface of the substrate may also be used.

  As a method for forming the plating layer on the surface of the substrate, there are electrolytic plating and electroless plating, either of which may be used. In particular, the electroless plating can form a plating layer uniformly and accurately regardless of the rough surface of the convex portion.

  Specifically, the plating layer is preferably formed from a layer made of a nonmagnetic metal, alloy, or metal compound selected from the group consisting of nickel, chromium, molybdenum, and palladium. For example, electroless Ni-P plating Electroless Ni-B plating, electroless Pd plating, electroless Pd-P plating, electroless Cr plating, electrolytic Mo plating, or electroless Mo plating. The physical properties of the plating layer are preferably nonmagnetic or weakly magnetic when a magnet roll is disposed inside the sleeve.

  The thickness of the plating layer is 0.5 μm to 20 μm, preferably 3 μm to 15 μm. When the thickness of the plating layer is less than 0.5 μm, the layer thickness is thin, so that the effect of providing the plating layer is difficult to be exhibited. When the thickness of the plating layer exceeds 20 μm, the plating layer existing on the substrate surface It becomes difficult to maintain the thickness of the film uniformly in the longitudinal direction.

  For example, regarding the Ni—P plating, Ni is a ferromagnetic substance by itself, but becomes amorphous by reacting with phosphorus or boron during electroless plating, and the magnetism is weakened. Also in the case of electroless Cr plating, if the plating layer is 20 μm or less, it can be used sufficiently rather than actually disturbing the magnetic field of the internal magnet.

  Further, when the conductive coating layer is made of resin, generally known resins can be used as the binder resin material. For example, thermoplastic resins such as styrene resins, vinyl resins, polyethersulfone resins, polycarbonate resins, polyphenylene oxide resins, polyamide resins, fluororesins, fiber resins, acrylic resins, epoxy resins, polyester resins, alkyd resins Thermal or photo-curable resins such as phenol resin, melamine resin, polyurethane resin, urea resin, silicone resin, polyimide resin, etc. can be used.

  Among them, releasable resins such as silicone resins and fluororesins, or polyether sulfone resins, polycarbonate resins, polyphenylene oxide resins, polyamide resins, phenol resins, polyester resins, polyurethane resins, styrene resins, acrylic resins A resin having excellent mechanical properties is more preferable.

The volume resistance value of the conductive coating layer in the present invention is preferably 10 ⁴ Ω · cm or less, more preferably 10 ³ Ω · cm or less. If the volume resistance value exceeds 10 ⁴ Ω · cm, poor charging of toner tends to occur, and as a result, blotch may occur.

  In order to adjust the volume resistance value of the conductive coating layer to the range of this value, it is preferable to contain the following conductive substance (conductive agent) in the coating layer. Examples of the conductive material used at this time include metal powders such as aluminum, copper, nickel, and silver, metal oxides such as antimony oxide, indium oxide, and tin oxide, carbon fiber, carbon black, and graphite. Examples thereof include carbonized substances.

  Among these, carbon black, especially conductive amorphous carbon, is excellent in conductivity and can be set to some degree of conductivity simply by filling the polymer material to impart conductivity and controlling the amount of addition. This is preferable.

  When carbon black is used as the conductive material, the amount added is suitably in the range of 1 to 100 parts by mass with respect to 100 parts by mass of the binder resin.

  In order to make the surface roughness of the conductive coating layer uniform and maintain an appropriate surface roughness, a more preferable result can be obtained by adding solid particles (concave / convex imparting particles) for forming the unevenness.

  As the solid particles that can be used for this purpose, spherical particles are preferable because a desired surface roughness can be obtained with a smaller addition amount and irregularities with a uniform surface shape can be formed as compared with amorphous particles.

  The spherical particles used here have a volume average particle size of 0.3 μm to 30 μm, preferably 2 μm to 20 μm. By adding such spherical particles, it is possible to maintain a uniform surface roughness on the conductive coating layer in the developer carrier, and even if the surface of the conductive coating layer is worn, the surface roughness of the conductive coating layer is maintained. The change in the thickness is small, the change in the toner layer thickness on the developer carrying member hardly occurs, the charge of the toner is made uniform, the sleeve ghost does not occur, and the stripe and the unevenness hardly occur. Further, it is possible to exert the effect of preventing the occurrence of sleeve contamination and fusion due to toner on the developer carrying member over a long period of time.

  When the volume average particle diameter of the spherical particles is less than 0.3 μm, it is impossible to impart a uniform surface roughness to the surface of the conductive coating layer, and the toner is charged up due to wear of the conductive coating layer. The sleeve is easily contaminated and fused. As a result, image deterioration and image density reduction due to sleeve ghost may occur. On the other hand, if it exceeds 30 μm, the surface roughness of the conductive coating layer becomes too large, the amount of toner transport increases, the toner coat on the surface of the developing sleeve becomes non-uniform, and the toner is uniformly charged. It becomes difficult. Further, since coarse particles protrude on the surface, it causes white spots and black spots due to image streaks and bias leaks. Furthermore, the mechanical strength of the conductive coating layer may decrease.

  The spherical shape in the spherical particles used herein means that the ratio of major axis / minor axis of the particles is about 1.0 to 1.5. In particular, particles having a major axis / minor axis ratio of 1.0 to 1.2, preferably spherical particles are preferably used. When the ratio of the major axis / minor axis of the spherical particles exceeds 1.5, the dispersibility of the spherical particles in the conductive coating layer decreases, and a large number of particles are added to obtain the desired surface roughness. Necessary. Therefore, the surface shape of the coating layer is likely to be non-uniform, and there are cases where the toner is uniformly charged and the strength of the coating layer is insufficient.

  As the spherical particles used here, any conventionally known spherical particles can be used as long as their volume average particle diameter is 0.3 μm to 30 μm. Examples include spherical resin particles, spherical metal oxide particles, and spherical carbonized particles.

  Among these, spherical resin particles are preferable because when they are added to the conductive coating layer, a suitable surface roughness can be obtained with a smaller addition amount and a uniform surface shape can be easily obtained. The spherical resin particles used here can be easily obtained, for example, by suspension polymerization, dispersion polymerization, or the like. Of course, particles obtained by spheroidizing resin particles obtained by a pulverization method by thermal and physical spheronization treatment may be used.

  Specific examples of the spherical resin particles include, for example, acrylic resins such as polyacrylate resins and polymethacrylate resins, polyamide resins such as polyamide-6,6 and polyamide-6, polyolefin resins such as polyethylene and polypropylene, Examples thereof include spherical particles made of a generally known resin such as a silicone resin, a phenol resin, a polyurethane resin, a styrene resin, and a benzoguanamine resin.

  In addition, the spherical particles used in the present invention may be adhered or fixed with inorganic fine powder on the surface thereof. For example, by treating the spherical resin particle surface with the inorganic fine powder as described below, the dispersibility of the spherical particles in the conductive coating layer is improved, and the uniformity of the surface of the formed conductive coating layer In addition, the contamination resistance of the conductive coating layer, the charge imparting property to the toner, the wear resistance of the conductive coating layer, and the like can be improved.

Examples of the inorganic fine powder used at this time include oxides such as SiO ₂ , SrTiO ₃ , CeO ₂ , CrO, Al ₂ O ₃ , ZnO and MgO, nitrides such as Si ₃ N ₄ , and SiC. Examples thereof include sulfates and carbonates such as carbides, CaSO ₄ , BaSO ₄ , and CaCO ₃ . These inorganic fine powders may be treated with a coupling agent. For the purpose of improving the adhesion between the spherical particles and the binder resin, or for the purpose of imparting hydrophobicity to the spherical particles, an inorganic fine powder treated with a coupling agent can be preferably used.

  Examples of the coupling agent used at this time include a silane coupling agent, a titanium coupling agent, a zircoaluminate coupling agent, and the like. Specifically, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchloro as silane coupling agents. Silane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethyldiethoxysilane , Dimethyldimethoxysilane, diphenylethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisilo Xylene, 1,3-diphenyltetramethyldisiloxane, and dimethyl having 2 to 12 siloxane units per molecule and containing a hydroxyl group bonded to one silicon atom in each terminal unit Polysiloxane etc. are mentioned.

True density of spherical particles, as used herein, 3 g / cm ³ or less, preferably 2.7 g / cm ³ or less, it is more preferably at ^{0.9g / cm 3 ~2.5g / cm 3} . That is, when the true density of the spherical particles exceeds ³ g / cm ³ , it is necessary to add a large amount of particles to impart an appropriate surface roughness to the conductive coating layer. In addition, the density difference between the spherical particles and the binder resin is too large, the dispersibility of the spherical particles in the conductive coating layer becomes insufficient, and it becomes difficult to impart a uniform surface roughness to the conductive coating layer. It becomes difficult to uniformly charge the toner.

  Further, the spherical particles are preferably conductive. By imparting conductivity to the spherical particles, electric charges are less likely to accumulate on the particle surface compared to insulating particles. Therefore, the inclusion of such conductive spherical particles in the conductive coating layer has the effect of uniforming the surface roughness of the conductive coating layer through durable use, and also reduces the adhesion of toner spherical particles. This further suppresses the occurrence of contamination of the developer carrying member by the toner, fusion of the toner to the developer carrying member, and the like. Thereby, the charge imparting property to the toner is further improved, and the developability is further improved.

The conductivity of the conductive spherical particles means that the volume resistance value is 10 ⁶ Ω · cm or less, preferably 10 ⁶ Ω · cm to 10 ⁻³ Ω · cm. When the volume resistivity of the conductive spherical particles exceeds 10 ⁶ Ω · cm, the effect of making the spherical particles conductive, that is, the toner that is likely to be generated with the spherical particles exposed on the surface of the conductive coating layer due to abrasion as the nucleus. The effect of suppressing sleeve contamination and fusion cannot be obtained.

  The method for obtaining the conductive spherical particles is preferably the method described below, but is not necessarily limited thereto. For example, a method of obtaining highly conductive spherical carbon particles by carbonizing and / or graphitizing by firing resin-based spherical particles or mesocarbon microbeads. Examples of the resin used for the resin-based spherical particles include phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, polyacrylonitrile, and the like. In addition, mesocarbon microbeads can be usually produced by washing spherical crystals formed in the process of heating and firing the medium pitch with a large amount of a solvent such as tar, medium oil, and quinoline.

  As a more preferable method for obtaining conductive spherical particles, the surface of spherical resin particles made of phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, polyacrylonitrile, etc. Examples thereof include a method in which bulk mesophase pitch is coated by a mechanochemical method, then heat-treated in an oxidizing atmosphere, and then calcined to be carbonized and / or graphitized to obtain conductive spherical carbon particles as conductive spherical particles.

The conductive spherical carbon particles obtained by the method described above are preferably used because any method can control the conductivity of the spherical carbon particles obtained by changing the firing conditions to some extent. In some cases, the obtained spherical carbon particles may be plated with a conductive metal and / or metal oxide within a range where the true density of the conductive spherical particles does not exceed ³ g / cm ³ in order to further increase the conductivity. May be given.

  As another method for obtaining conductive spherical particles, a non-conductive spherical resin particle is used as a core particle, and conductive fine particles smaller than the particle size of the core particle are mechanically mixed at an appropriate blending ratio to obtain a fan. After the conductive fine particles are uniformly adhered around the core particles by Delwars force and electrostatic force, the core particle surface is softened by, for example, local temperature rise caused by applying mechanical impact force. There is a method of fixing conductive fine particles to obtain spherical resin particles obtained by conducting a conductive treatment.

  For the core particles of the conductive spherical particles, it is preferable to use spherical resin particles having a small true density made of an organic compound. Examples of the resin include PMMA resin, acrylic resin, polybutadiene resin, polystyrene resin, polyethylene resin, Polypropylene resins, polybutadiene resins, or copolymers thereof, benzoguanamine resins, phenol resins, polyamide resins, fluorine resins, silicone resins, epoxy resins, polyester resins, and the like can be used.

  The conductive fine particles (small particles) fixed on the surface of the core particles (mother particles) are small particles having a particle size of 1/8 or less of the particle size of the mother particles in order to uniformly coat the conductive particles. It is preferred to use particles.

  As another method for obtaining conductive spherical particles, there is a method in which conductive fine particles are uniformly dispersed in spherical resin particles to obtain conductive spherical particles in which conductive fine particles are dispersed and encapsulated. As a method for uniformly dispersing the conductive fine particles in the spherical resin particles, for example, the raw material resin and the conductive fine particles are kneaded to disperse the conductive fine particles, then cooled and solidified, and pulverized to a predetermined particle size. , A method of obtaining conductive spherical particles by spheronizing by mechanical treatment and thermal treatment, and adding a polymerization initiator, conductive fine particles and other additives into a polymerizable monomer which is a raw material of raw material resin, and dispersing The monomer composition uniformly dispersed by a machine was suspended in an aqueous phase containing a dispersion stabilizer so as to have a predetermined particle size by a stirrer and polymerized to disperse conductive fine particles. There is a method for obtaining spherical particles.

  Even in the conductive spherical particles in which the conductive fine particles obtained by these methods are dispersed, they are further mechanically mixed with the conductive fine particles having a particle diameter smaller than that of the core particles at an appropriate blending ratio to obtain van der Waals. After the conductive fine particles are uniformly deposited around the conductive spherical particles by the action of force and electrostatic force, the surface of the conductive spherical particles is softened by a local temperature rise caused by applying a mechanical impact force, for example. The conductive fine particles may be fixed to the surface to further increase the conductivity.

  The spherical particles dispersed in the conductive coating layer optimize the surface roughness of the surface of the developing sleeve and further uniformize the surface shape, thereby uniforming the toner transport on the sleeve and causing wear. Even in this case, the change in the surface roughness is suppressed, the change in the transport amount of the developer due to endurance use is suppressed, and the toner is quickly and uniformly charged and charged. As a result, the effect of preventing charge-up and preventing sleeve ghost, and the effect of preventing sleeve contamination and fusing by toner can be exhibited over a long period of time. Among these, spherical carbon particles are particularly preferable because they do not impair the conductivity of the conductive coating layer and can prevent toner adhesion / fusion with the particles as a core.

  In addition, it is preferable to disperse the solid lubricant in combination with the spherical particles in the conductive coating layer because the surface lubricity is increased and the durability of the conductive coating layer is improved. Examples of the solid lubricant include substances composed of fatty acid metal salts such as crystalline graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, talc, and zinc stearate. Etc. Among these, crystalline graphite is preferable because it does not impair the conductivity of the conductive coating layer even when used in combination with spherical particles.

  As this solid lubricant, one having a volume average particle diameter of preferably 0.2 μm to 20 μm, more preferably 1 μm to 15 μm is used. When the volume average particle size of the solid lubricant is less than 0.2 μm, sufficient lubricity may not be imparted. When the volume average particle size exceeds 20 μm, the surface roughness of the conductive coating layer is greatly affected, and it is easy to be scraped by durable use. Therefore, the developer coating on the developer carrying member and the charged state of the developer may become unstable. Since the solid lubricant is added to increase the lubricity of the conductive coating layer, it is desirable that the volume average particle size is smaller than the spherical particles when used in combination with the spherical particles.

  Further, in order to adjust the chargeability of the developer carrying member, a charge control agent may be contained in the conductive coating layer.

  Examples of charge control agents include, for example, modified products of nigrosine and its fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Analogous onium salts such as phosphonium salts and lake pigments (including phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) ), Metal salts of higher fatty acids; diorganotin oxides such as butyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; diols such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate Nosuzuboreto like; guanidines, imidazole compounds.

  Among these charge control agents, when a negative toner having a particularly high sphericity is used as a developer, a quaternary ammonium salt compound having a positive charge polarity may be included in the conductive coating layer as the charge control agent. The toner is preferably charged with good charge. At this time, the binder resin further preferably has at least an amino group, ═NH group or —NH— bond in its structure.

  In other words, by providing a conductive coating layer in which a quaternary ammonium salt compound and a specific binder resin are combined, it becomes possible to prevent the negative toner having a high degree of spheroidization from being excessively charged, and to provide appropriate frictional charging. Can do. As a result, it is possible to prevent the toner on the developer carrying member from being charged up, to prevent toner fusion on the surface of the conductive coating layer, and to maintain high charging stability of the toner. A high-definition image having stability and long-term stability can be provided.

  The quaternary ammonium salt compound that can be used here may be any compound as long as the charge polarity is positive. For example, a compound represented by the following general formula (1) may be mentioned.

一般式（１）中、Ｒ１、Ｒ２、Ｒ３およびＲ４は、それぞれ独立に、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、アラルキル基を表し、Ｘ^-は酸の陰イオンを表す。

In general formula (1), R 1, R 2, R 3 and R 4 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl group, and X ⁻ represents Represents the acid anion.

The acid ion of X ⁻ in the general formula (1) is preferably an organic sulfate ion, an organic sulfonate ion, an organic phosphate ion, a molybdate ion, a tungstate ion, a heteropolyacid containing a molybdenum atom, or a tungsten atom.

  Examples of the quaternary ammonium salt compound that is preferably used in the present invention and has a positive charge polarity per se include those described in Tables 1 to 3 below.

  Phenol resin produced using a nitrogen-containing compound as a catalyst in the production process as a preferred resin containing an amino group, ═NH group or —NH— bond in the structure in combination with these quaternary ammonium salts; polyamide resin An epoxy resin using polyamide as a curing agent; a urethane resin; a copolymer partially containing these resins, and the like. The quaternary ammonium salt compound is easily taken into the structure of the coating resin when the mixture with the coating resin is formed.

  As a phenol resin that can be suitably used in combination with a quaternary ammonium salt, a nitrogen-containing compound used as a catalyst in the production process is, for example, ammonium sulfate, ammonium phosphate, ammonium sulfamate, ammonium carbonate, Ammonium salts or amine salts such as ammonium acetate and ammonium maleate are also used as basic catalysts such as 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, tri Amino compounds such as isopropanolamine, ethylenediamine, hexamethylenetetramine; pyridines such as pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine; and derivatives thereof; quinoline compounds, imidazole, 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecyl Imidazole and nitrogen-containing heterocyclic compounds such derivatives such as imidazole and the like.

  Moreover, as a polyamide resin, for example, polyamide (PA) -6, PA-6,6, PA-6,10, PA-11, PA-12, PA-9, PA-13, etc. are mainly composed of these. Any of polyamide copolymers, N-alkyl-modified polyamides, N-alkoxylalkyl-modified polyamides and the like can be suitably used. Furthermore, any resin containing an amide bond 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 can be used. it can.

  Any urethane resin may be used as long as it contains a urethane bond. The urethane resin is obtained by a polymerization addition reaction of polyisocyanate and polyol. As the polyisocyanate that is the main raw material of this urethane resin, tolylene diisocyanate (TDI), pure diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), tolidine diisocyanate (TODI), naphthalene diisocyanate (NDI), xylylene Aromatic polyisocyanates such as range isocyanate (XDI); aliphatic polyisocyanates such as hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated XDI, and hydrogenated MDI; Polyether polyol such as polyoxypropylene glycol (PPG), polymer polyol, polytetramethylene glycol (PTMG); Polyester polyols such as polyadipate, polycaprolactone, polycarbonate polyol; polyether modified polyols such as urea / urethane modified polyol (PHD polyol) and polyether ester polyol; other epoxy modified polyols; ethylene-vinyl acetate copolymer Partially saponified polyol (saponified EVA); flame retardant polyol and the like.

  As a method for forming the conductive coating layer, for example, each component can be dispersed and mixed in a solvent to form a paint, and then coated on the substrate. For dispersion mixing of each component, a known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, a pearl mill or the like can be suitably used. Moreover, as a coating method, well-known methods, such as a dipping method, a spray method, and a roll coat method, are applicable.

  The roughness of the surface of the developer carrying member, that is, the surface of the resin coating layer (Ra: JIS arithmetic average roughness) varies depending on the developing method, but is generally in the range of 0.2 μm to 3.5 μm. preferable.

  For example, in the developing device as shown in FIG. 6 using a magnetic one-component toner and having a magnetic blade disposed as a developer layer thickness regulating member with a developer carrier and a gap, Ra is about 0.3 μm to 2.5 μm. It is desirable that If the thickness is less than 0.3 μm, the developer is not sufficiently conveyed, and the image density is thin due to lack of developer, and scattering or blotch due to excessive charging is likely to occur. The frictional charge of the image becomes uneven, and stripe unevenness, reversal fog, and low image density due to insufficient charging are likely to occur.

  For example, in the case of a developing device in which the elastic member is used in pressure contact with the developer carrying member as shown in FIGS. 5 and 7, Ra is desirably about 0.5 μm to 3.5 μm. If the thickness is less than 0.5 μm, the developer may not be sufficiently conveyed, and image density may be thin due to insufficient developer, scattering or blotch may occur due to excessive charging, and toner fusion to the developer carrier may occur. Wear is also likely to occur. On the other hand, if it exceeds 3.5 μm, the frictional charge of the toner becomes non-uniform, and streaks, reversal fogging, and low image density due to insufficient charging are likely to occur.

  Next, the resin composition used for the resin layer on a part or the entire surface of the developer carrying member important in the present invention will be described.

  As the resin material of the resin composition used for the resin layer, generally known resins can be used. However, the same applies to the lubricating particles (supported particles) and iron powder to be supported on the resin layer, which will be described later. A resin having a charged series on the polar side is used. For example, those having a negative charge polarity include, for example, silicone resins; fluorine-containing resins such as polyvinylidene fluoride, polyfluorinated ethylene, polytetrafluoroethylene, and polyfluorinated carbon; single amounts such as styrene, acrylic acid, and acrylate esters. Examples of the vinyl-based resin obtained by polymerizing the body and having a positive charging polarity include melamine resin, guanamine resin, aniline resin, urea resin, and polymethyl methacrylate.

  It is also possible to use a charge control resin obtained by copolymerizing a monomer having a polar group with a basic monomer, or by adding this to the above resin.

  For example, the negatively chargeable charge control resin includes a copolymer of at least a vinyl polymerizable monomer and a sulfonic acid group-containing acrylamide monomer.

  More specifically, the vinyl polymerizable monomer includes styrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl methacrylate, cyclohexyl. (Meth) acrylate, dimethyl (amino) ethyl (meth) acrylate, diethyl (amino) (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylic acid, vinyl acetate, vinyl propionate, and the like. Or a mixture of two or more. A combination of styrene and an acrylic ester or methacrylic ester is preferred.

  Examples of the sulfonic acid group-containing acrylamide monomer include 2-acrylamidopropanesulfonic acid, 2-acrylamide-n-butanesulfonic acid, 2-acrylamide-n-hexanesulfonic acid, 2-acrylamide-n-octanesulfonic acid, 2-acrylamide-n-dodecanesulfonic acid, 2-acrylamide-n-tetradecanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-phenylpropanesulfonic acid, 2-acrylamide-2,2, 4-trimethylpentanesulfonic acid, 2-acrylamido-2-phenylpropanesulfonic acid, 2-acrylamido-2- (4-chlorophenyl) propanesulfonic acid, 2-acrylamido-2-carboxymethylpropanesulfonic acid, 2-acrylic Mido-2- (2-pyridyl) propanesulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 3-acrylamido-3-methylbutanesulfonic acid, 2-methacrylamide-n-decanesulfonic acid, 2-methacrylamide -N-tetradecanesulfonic acid etc. can be mentioned. 2-acrylamido-2-methylpropanesulfonic acid is preferred.

  Further, as a positively chargeable charge control resin, a copolymer of at least a vinyl polymerizable monomer and a nitrogen-containing vinyl monomer can be mentioned.

  The same vinyl polymerizable monomer as described in the negatively chargeable charge control resin can be used.

  The nitrogen-containing vinyl monomer may be any nitrogen-containing vinyl monomer that can be copolymerized with a vinyl polymerizable monomer, and the nitrogen atom may be quaternary ammonium.

  Examples of nitrogen-containing vinyl monomers include p-dimethylaminostyrene, dimethylaminomethyl acrylate, dimethylaminoethyl acrylate, dimethylaminopropyl acrylate, diethylaminomethyl acrylate, diethylaminoethyl acrylate, dimethylaminomethyl methacrylate, dimethylaminomethyl methacrylate, Dimethylaminopropyl methacrylate, diethylaminomethyl methacrylate, diethylaminoethyl methacrylate and the like, and N-vinylimidazole, N-vinylbenzimidazole, N-vinylcarbazole, N-vinylpyrrole, N-vinylpiperidine, N-vinylmorpholine, There are nitrogen-containing heterocyclic N-vinyl compounds such as N-vinylindole. In particular, nitrogen-containing vinyl compounds represented by the following chemical formula (2) such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate are preferred.

式中、Ｒ５〜Ｒ８は、それぞれ独立に、水素原子あるいは炭素数１〜４の飽和炭化水素基であり、ｎは１〜４の整数である。

In formula, R5-R8 is respectively independently a hydrogen atom or a C1-C4 saturated hydrocarbon group, and n is an integer of 1-4.

  Further, when the nitrogen-containing vinyl monomer is a quaternary ammonium group-containing vinyl monomer, its structure is not particularly limited as long as it is copolymerizable with the vinyl polymerizable monomer, but more preferably, It is a quaternary ammonium group-containing vinyl monomer represented by the formula (3).

式中、Ｒ９は、水素原子又はメチル基であり、Ｒ１０〜１２は、それぞれ独立に、メチル基、エチル基又はプロピル基であり、Ｘは、−Ｏ−又は−ＮＨ−であり、Ａ^-は、Ｃ１^-、（１／２）ＳＯ₄ ^2-のようなアニオンであり、ｍは１〜４の整数である。

In the formula, R 9 is a hydrogen atom or a methyl group, R 10 to 12 are each independently a methyl group, an ethyl group or a propyl group, X is —O— or —NH—, and A ⁻ is , C1 ⁻ , (1/2) SO ₄ ²⁻ , and m is an integer of 1 to 4.

  Moreover, it is also preferable to use a polymer having an imidazolium salt represented by the following general formula (4) as a structural unit as a positively chargeable charge control resin.

式中、Ｒ１３〜Ｒ１５は、それぞれ独立に、水素、置換基を有していてもよいシクロアルキル基、置換基を有していてもよいアリール基、置換基を有していてもよいアリル基、置換基を有していてもよいアラルキル基、置換基を有していてもよいアルコキシ基、置換基を有していてもよいアミノ基、ハロゲン又は置換基を有していてもよい複素環類であり、また、Ｒ１３とＲ１４は互に連結して環を形成してもよい。Ｄは、置換基を有していてもよいアルキレン基（主鎖中にエーテル結合を有していてもよく、また、不飽和結合を有していてもよい）、置換基を有していてもよいアルキリデン基、置換基を有していてもよいシクロアルキレン基又は置換基を有していてもよいフェニル基であり、Ｂ^-は、対イオンである。ｋは２〜１００の整数である。

In the formula, R13 to R15 each independently represent hydrogen, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, or an allyl group which may have a substituent. , An aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an amino group which may have a substituent, a halogen or a heterocyclic ring which may have a substituent R13 and R14 may be linked to each other to form a ring. D is an alkylene group that may have a substituent (may have an ether bond in the main chain or may have an unsaturated bond), and has a substituent. Or an alkylidene group, an optionally substituted cycloalkylene group, or an optionally substituted phenyl group, and B ⁻ is a counter ion. k is an integer of 2 to 100.

  Here, examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, an allyl group, an aralkyl group, an alkoxy group, an amino group, an amide group, a halogen, and a heterocyclic ring. Further, these substituents are ether bonds, You may have a sulfide bond.

  These combinations are not uniquely limited, but in order to impart high positive chargeability to the toner, in general formula (4), R13 to R15 are hydrogen, an alkyl group, a cycloalkyl group, an aryl group. , An allyl group, an aralkyl group or a heterocyclic group, which may be the same or different. These substituents may further have a substituent. In addition, as carbon number, it is preferable that it is 1-40. Moreover, what formed the aromatic ring and the heterocyclic ring by mutually connecting by R13 and R14 is also preferable. D is preferably a C 1-8 alkylene group or a C 1-8 alkylene group containing an ether bond in the main chain.

  A polymer comprising an imidazolium salt having the general formula (4) as a constituent component is a polymerized reaction of an imidazolium represented by the following general formula (5) with a dihalide, and if necessary, the halogen salt is converted to another anion. (See JP-A-10-20562, JP-A-2004-333666, etc.).

上記において、Ｒ１３〜Ｒ１５、Ｂ、Ｄ及びｋは一般式（４）におけると同じ意味を表し、Ｘはハロゲン原子を表す。

In the above, R13 to R15, B, D, and k represent the same meaning as in general formula (4), and X represents a halogen atom.

  In addition, it is more preferable that D is graft-bonded to a polymer main chain composed of a vinyl polymerizable monomer because a resin layer can be easily formed on the conductive coating layer. In addition, when the above polymerization reaction is performed in the presence of another thermoplastic polymer, it can be graft-polymerized to the thermoplastic polymer.

  As thermoplastic polymer, polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer Polymer, styrene-methacrylic acid ester copolymer, styrene-σ-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene -Styrene copolymers such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, and styrene-acrylonitrile-indene copolymer: polypinyl chloride; phenol resin; modified phenol resin; resin Modified male Acid resins; Acrylic resins; Methacrylic resins; Polyvinyl acetate; Silicone resins; Polyester resins; Polyurethane resins; Polyamide resins; Furan resins; Epoxy resins; Xylene resins; Polyvinyl butyral resins; A coumarone indene resin; a petroleum resin and the like.

  Among them, in particular, polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester copolymer, methacrylic resin, acrylic resin easily form a resin layer. This is preferable because it is possible.

  The graft polymer need not have a structure in which only one end of the polymer chain of the imidazolium salt is bonded to the main chain, but has a structure in which both ends are bonded to the main chain (block polymer structure). It includes what is.

  In general formula (4) of imidazolium salts, R13 to R15 preferably have 1 to 40 carbon atoms, but more preferably have 20 or less carbon atoms. That is, when any of R13 to R15 has more than 20 carbon atoms, the softening point of the polymer itself containing imidazolium salts as a structural unit is lowered, and the mechanical properties of the resin layer provided on the developer carrier The strength may decrease.

Polymer as constituent units imidazolium salts, in B the general formula (4) ^- as shown as having an anion.

This anion can be used regardless of whether it is inorganic or organic. Specifically, F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , OH ⁻ , S 0 ₄ ²⁻ , NO ³⁻ , PO ₄ ^{3 _{-, BF 4 -, MoO 4}} 2-, WO 4 2-, ClO 4 -, SiF 6 2- , etc. inorganic ^{_{anion, [TeMo 6 O 24] 6-}} , [H 2 W 12 O 42] 10- , [PMo ₁₂ O ₄₀ ] ³⁻ , [PW ₁₂ O ₄ ] ^3−, etc., heteropolyacid ions, CH ₃ COO ⁻ , C ₂ H ₅ COO ⁻ , C ₁₇ H ₃₅ COO ^−, etc. carboxylate ^{_{ion, CH 3 S0 3 -, CH}} 3 C 6 H 4 SO 3 - carbon atoms 1 to 24 sulfonic acid ion, C ₂ H ₅ OS0 ₃ such ^- sulfuric monoalkyl esters having 1 to 24 carbon atoms, such as Organic anions such as anions and tetraphenylboron ions are exemplified. Among these, halogen ions, SO ₄ ²⁻ , MoO ₄ ²⁻ , WO ₄ ²⁻ , hydroxynaphthosulfonate ion, benzoate ion, and monoalkyl sulfate ion having 1 to 6 carbon atoms are easy in production. From the viewpoint of storage stability of the compound. More preferred is a halogen ion.

  Furthermore, for the purpose of suppressing the charge-up of the supported particles in the initial state of image output and preventing the electrostatic aggregation of the particles and the strong adhesion to the surface of the developer carrier, the resin layer has the following conductive properties. It is preferable to add a conductive material to impart conductivity.

  Since the amount of the resin layer present on the surface of the developer carrying member is very small, it is desirable that the conductive material contained in the resin layer is fine, and the particle size is preferably 1 μm or less.

  Examples of the conductive material that can be used here include metal powders such as aluminum, copper, nickel, and silver, metal oxides such as antimony oxide, indium oxide, and tin oxide, carbon fiber powder, carbon such as carbon black, and graphite. Thing etc. are mentioned.

  Of these, fine carbon black having a primary particle size of 1 μm or less is suitable. In particular, conductive amorphous carbon is particularly excellent in conductivity, and it has an arbitrary conductivity only by controlling its addition amount. This is preferable because it can be achieved.

  The resin layer of the present invention is a known coating material obtained by dispersing the above-mentioned components together with a resin for the resin layer in a solvent on the conductive coating layer, such as a dipping method, a spray method, and a roll coating method. It is formed by coating by a method and then drying and solidifying. In addition, a known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, and a pearl mill can be suitably used for forming a paint.

The resin layer is preferably formed so as to be 5.0 × 10 ⁻⁴ kg / m ^{2 to} 2.0 × 10 ⁻³ kg / m ² . If it exceeds 2.0 × 10 ⁻³ kg / m ² , the resin layer will remain indefinitely even after the carrier particles have disappeared, and the performance of the surface of the developer carrier will not be the original performance of the conductive coating layer. In some cases, the chargeability of the resin layer becomes unstable, and if it is less than 5.0 × 10 ⁻⁴ kg / m ² , the effect of forming the resin layer, for example, the effect of imparting charge to the support particles may be reduced. .

  The resin layer is preferably formed on the surface of the conductive coating layer, but it is not necessary that the conductive coating layer is completely covered with the resin layer as long as a homogeneous surface is formed. . That is, the resin layer may be formed on a part of the surface of the conductive coating layer.

  The developer carrying body in which the resin layer is formed on the conductive coating layer has fine particles in advance on the entire surface of the developer carrying body or / and the contact portion of the developer layer thickness regulating member with the developer carrying body. It is used by being incorporated in an image forming apparatus and its process cartridge. When fine particles are applied and incorporated in the developer layer thickness regulating member, the developer carrier is rotated prior to use so that the fine particles are uniformly carried on the surface of the developer carrier.

  Next, the fine particles (carrying particles) carried on the surface of the developer carrying member and / or the developer layer thickness regulating member used here will be described in more detail.

  It is important that the supported particles have the same charging polarity as the resin layer formed on the conductive coating layer.

  As the support particles, fine particles made of a resin appropriately selected from the resin group shown to be suitable for the resin layer can be used. Preferably, the organic fine particles are formed of a resin such as silicone resin, PMMA, polyurethane, acrylic resin, polystyrene, melamine-formaldehyde resin, phenol resin, polytetrafluoroethylene, polytrifluoroethylene, or polyvinylidene fluoride. . Further, inorganic fine particles such as boron nitride, molybdenum disulfide, strontium titanate, silica, talc and the like are also preferably used.

  In the present invention, at least before the image forming apparatus incorporating the developer carrier is used for the first image output, that is, before the first developer is supplied to the surface of the developer carrier. Support particles are supported on the surface of the support.

  In the present invention, “supported particles are carried on the surface of the developer carrying member” means a state in which the carried particles are mainly electrostatically attached to the surface of the developer carrying member. That is, the supported particles are not firmly fixed on the surface of the developer carrying member (so that they are not detached even if the developing process is performed) or are not contained in the surface material of the developer carrying member. According to (increase in the number of images to be printed), it is gradually detached from the developer carrier.

  The supported particles preferably have at least a primary average particle size of 0.01 μm to 30.0 μm, preferably 0.1 μm to 20.0 μm. When the primary average particle diameter of the carrier particles is less than 0.01 μm, charging of the developer tends to be hindered and the image density may be lowered. Further, when the primary average particle diameter of the supported particles exceeds 30.0 μm, it is difficult to make the particles uniformly exist on the surface of the developer bearing member, and as a result, image defects such as vertical stripes may be caused.

The supported particles preferably have a true density of 3 g / cm ³ or less. If the true density of the support particles exceeds ³ g / cm ³ , it may be difficult to make the support particles uniformly exist on the surface of the developer support.

  The supported particles may have a particle size larger than that of the developer (toner particles) as long as the particle size is in the range specified above. This is because the carrier particles are preliminarily coated on the surface of the resin layer on the developer carrier, so that the carrier particles 1 are present on or in the rugged portion of the developer carrier surface as shown in FIG. As a result, the amount of the developer (toner particles) 5 carried on the developer carrying member is suppressed to a small amount, and the amount of toner developed during printing and the amount of toner newly supplied after the toner consumption are newly supplied to the developer carrying member. This is because the difference between the toner charge amount and the toner coat amount becomes small, so that the difference in developing power between the two becomes small, and as a result, the occurrence of sleeve ghost can be suppressed.

The amount to be carried on the developer carrying member surface of the carrier particles are also to other particles added as necessary, is preferably in the range of 0.2g / m ² ~2g / m ² in total. If the coating amount is less than 0.2 g / m ² , the coating amount is small, and coating unevenness is likely to occur. Improvement effects may not appear. If it exceeds ² g / m ² , the coating amount is too large, and these fine particles themselves may cover the entire surface of the developing sleeve, which may impair charging of the toner, resulting in density unevenness. In some cases.

  The carrier particles are supported on the surface of the developer carrier by directly coating the developer carrier, or by coating the developer layer thickness regulating member on the surface in contact with the developer carrier and supplying the developer in the image forming apparatus. There is a method of rotating the developer carrier before, and any of them may be used in the present invention.

  Note that the method described in Patent Document 5 can be applied to the surface of the developer particles on the surface of the developer layer thickness regulating member that contacts the developer carrier. That is, a method in which the supported particles are dispersed in a solvent and applied to the developer layer thickness regulating member with a nozzle connected to a brush, spray, spoid, pump, etc., and the tip of the developer layer thickness regulating member is placed in the dispersion of the supported particles. There are a method of dipping, a method of pressing the developer layer thickness regulating member while rotating a sponge roller carrying the carrier particles, and transferring the carrier particles.

  The method of directly applying the support particles on the surface of the developer support is achieved by supporting the support particles on a brush or the like and applying the support particles on the surface of the developer support. Preferably, the method as shown in FIG. Can be taken.

  In this method, the carrier particles 29 are coated on the sponge roller 26 and applied to the developer carrier 27 in contact therewith. The developer carrier 27 is disposed in the coating container 28 in parallel with the sponge roller 26. The developer carrier 27 is installed in such a manner that both end portions in the longitudinal direction of the developing sleeve 27 are pressed by a rotatable bearing (not shown) from the direction indicated by the arrow G in the drawing, and are uniformly introduced in the longitudinal direction from the surface of the sponge roller 26. Yes. The sponge roller 26 and the developing sleeve 27 rotate counter to each other (indicated by an arrow F in the figure), and the supported particles 29 on the sponge roller 26 are rubbed against the surface of the resin layer on the developing sleeve 27. Apply to. The amount of the carrier particles on the developing sleeve 27 is determined by the penetration amount of the developing sleeve 27 into the sponge roller 26, the rotational speed and relative speed of the developing sleeve 27 / sponge roller 26, and the absolute amount of the carrier particles 29 in the coating container. Is done. Further, in the subsequent assembly process or the like, when the developing sleeve 27 is rotated, a bias is applied to develop it on the photosensitive drum, so that the amount of the coating agent remaining on the developing sleeve 27 can be reduced as a result. Such a method of applying the carrier particles to the developer carrier does not transfer from the developer layer thickness regulating member in contact with the developer carrier to the resin layer surface on the developer carrier. Applicable not only to developing devices with a developer layer thickness regulating member of the elastic blade type, but also to developing devices of a magnetic blade type in which the developer layer thickness regulating member is mounted with a certain gap from the developer carrier. This is preferable because it can be used for a wider range of applications.

  The developer carrier of the present invention has a hardness measured from the top of the resin layer excluding the carrier particles (JIS K5600-1999 (General coating test method, Part 5: Mechanical properties of coating film, Section 4). : Scratch hardness (pencil method)) (pencil hardness) is preferably not more than H. When it is harder than H, the resin layer hardly peels off, and the resin layer remains even after the carrier particles disappear. Depending on the charge polarity of the resin layer, the toner is excessively charged or insufficiently charged due to friction, causing a sleeve ghost or blotch phenomenon or insufficient image density. Since it is a value when the outermost resin layer is peeled off by a pencil, there is no problem even if the hardness of the conductive coating layer exceeds H.

(Developer)
FIG. 5 is a diagram schematically illustrating an example of a developing device unit of an image forming apparatus used in the image forming method of the present invention.

  An electrostatic latent image carrier (photosensitive drum) 1 for carrying an electrostatic latent image is rotated in the direction of arrow B. The developing sleeve 8 facing the photosensitive drum 1 is composed of a metal cylindrical tube (base) 6 and a conductive coating layer 7 formed on the surface thereof. In the hopper 3, a stirring blade 10 for stirring the magnetic one-component toner 4 is provided. The magnetic one-component toner 4 supplied from the hopper 3 to the developing sleeve 8 is carried on the developing sleeve 8, and the developing sleeve 8 and the photosensitive drum 1 face each other when the developing sleeve 8 rotates in the direction of arrow A. The developed area D is conveyed. In the developing sleeve 8, a magnet 5 for magnetically attracting and holding the magnetic one-component toner 4 on the developing sleeve 8 is disposed. The magnetic one-component toner 4 is triboelectrically charged so that the electrostatic latent image on the photosensitive drum 1 can be developed by friction with the developing sleeve 8 and / or the elastic blade 11.

  The thin layer of magnetic one-component toner 4 formed by the elastic blade 11 on the developing sleeve 8 is preferably thinner than the minimum gap between the developing sleeve 8 and the photosensitive drum 1 in the developing region D. . That is, the present invention is particularly effective for a developing device that develops an electrostatic latent image with such a thin toner layer, that is, a so-called non-contact developing device. A developing bias voltage is applied to the developing sleeve 8 by a power source 9 in order to cause the magnetic one-component toner 4 carried on the developing sleeve 8 to fly. When a DC voltage is used as the developing bias voltage, the developing sleeve 8 is set to a voltage value between the potential of the image portion of the electrostatic latent image (the region visualized by toner adhesion) and the potential of the background portion. It is preferable to apply to. On the other hand, 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 8 to form an oscillating electric field whose direction is alternately reversed in the developing portion. In this case, an alternating bias voltage on which a DC voltage component having a value between the above-described image portion potential and background portion potential is superimposed is applied to the developing sleeve 8.

  In the so-called regular development, in which toner is attached to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion for visualization, toner charged to a polarity opposite to that of the electrostatic latent image is applied. On the other hand, in so-called reversal development, in which toner is attached to a low potential portion of an electrostatic latent image for visualization, toner charged with the same polarity as that of the electrostatic latent image is used. Note that high potential and low potential are expressions based on absolute values. In any case, the magnetic one-component toner 4 is charged to a polarity for developing the electrostatic latent image by friction with the developing sleeve 8.

  The toner image formed on the photosensitive drum 1 moves to a transfer portion (not shown) by the rotation of the photosensitive drum, and electrostatically is transferred onto a transfer member (not shown) supplied in synchronization with the rotation of the photosensitive drum 1 there. Is transcribed. The transfer member to which the toner image has been transferred is further sent to the fixing unit and fixed to form an image.

  In the present invention, it is important that the developing sleeve 8 is provided with a resin layer on the surface of the conductive coating layer 7. Further, immediately after the assembly of the developing device, it is important that the supported particles are present at the contact portion of the elastic blade 11 with the developing sleeve 8 or the supported particles are supported on the entire surface of the developing sleeve 8. When the carrier particles are carried on the elastic blade 11, the developing sleeve 8 is rotated several times before the magnetic one-component toner 4 is filled in the hopper 3, and the carrier particles on the elastic blade 11 are transferred to the developing sleeve 8. Then, it is evenly carried on the surface of the developing sleeve.

  It is not necessary for the elastic blade 11 to control the layer thickness of the magnetic one-component toner 4 on the developing sleeve 8, and a magnetic blade 2 opposed to the magnet 5 may be used as shown in FIG. . In this case, as the developing sleeve 8, one in which supporting particles are previously supported on a resin layer is used. The gap between the magnetic blade 2 and the developing sleeve 8 is usually 50 to 500 μm. In FIG. 6, the magnetic line of force from the N1 pole of the magnet 5 is concentrated on the magnetic blade 2, whereby a thin layer of the magnetic one-component toner 4 is formed on the developing sleeve 8.

  When the developer 4 is a non-magnetic one-component toner, as shown in FIG. 7, the developer carrier 8 does not necessarily have a cylindrical base 6, and may have a cylindrical shape. In addition, it is necessary that the conductive coating layer 7 is formed on the base 6 and a resin layer is further formed on the surface thereof. An elastic roller that supplies new non-magnetic one-component toner to the developer carrier 8 and scrapes off the non-magnetic one-component toner that returns to the hopper 3 without being used for development. 13 is in contact. The elastic roller 13 functions to frictionally charge the nonmagnetic one-component toner 4 together with the developer carrier 8 and the developer layer thickness regulating member (elastic blade) 11.

  The non-magnetic one-component toner carried on the developer carrying member 8 is regulated in layer thickness (carrying amount) by the elastic blade 11 and charged to develop the electrostatic latent image formed on the photosensitive drum 1. Further, the toner is fed to the developing area D facing the photosensitive drum 1 by the rotation of the developer carrier 8.

  In the developing region D, the non-magnetic one-component toner electrostatically flies or contacts the electrostatic latent image from the developer carrier 8 to develop the electrostatic latent image. In this development, a static voltage is applied from the power source 9 between the photosensitive drum 1 and the developer carrier 8 in order to efficiently transfer the nonmagnetic one-component toner to the electrostatic latent image. At this time, an alternating voltage as described above can be applied in order to increase the contrast of the developed toner image.

  The developer carrying member 8 further rotates and returns to the hopper 3 while carrying the non-magnetic one-component toner that has not been used for development, where the non-magnetic one-component toner is scraped off from the surface by the elastic roller 13, and The non-magnetic one-component toner is newly carried by the elastic roller 13.

  On the other hand, the toner image formed on the photosensitive drum 1 moves to the transfer region as the photosensitive drum 1 rotates, and is electrostatically transferred to the transfer member supplied in synchronization therewith. The transfer member to which the toner image has been transferred is carried to the fixing region, where the toner image is fixed to the transfer member.

  In assembling the apparatus, it is preferable to carry the supported particles on the elastic blade 11 and the developer carrier 8. When assembling the elastic blade 11 with the carrier particles, the developer carrier 8 is rotated in advance several times before supplying the non-magnetic one-component toner to the hopper 3, and the carrier particles are formed on the surface of the developer carrier 8. Is supported evenly. However, it is preferable to carry the carrier particles on the developer carrier 8 in advance to assemble the carrier particles, because such an operation is unnecessary and problems such as the developer carrier 8 sticking to the elastic roller 11 at the contact portion can be prevented.

  Next, the toner used in the present invention will be described.

  The toner is a fine powder having a relatively spherical shape and a uniform particle size distribution, mainly composed of a binder resin, a release agent, a charge control agent, a colorant and the like.

  As the binder resin to be used, generally known thermoplastic resins can be used. For example, styrene such as styrene, α-methylstyrene, p-chlorostyrene, and substituted homopolymers thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-ethyl acrylate copolymer, styrene -Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer Polymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid Copolymer, styrene-maleic acid ester Copolymers such as styrene copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic resin, polyester, rosin, modified rosin, temper resin, phenol resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, carnauba wax and the like can be used alone or in combination.

  The colorant may be appropriately selected from known dye pigments depending on the color of the toner. For example, carbon black, nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgadin Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Bio Red B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Pomelo First Yellow CGG, Kaya Set Y963, Kaya Set YG, Pomelo First Orange RR, Oil Scarlet, Orazole Bra Down B, pomelo First Scarlet CG, Oil Pink OP, or the like can be used.

  When the toner is a magnetic one-component toner, magnetic powder is contained in the toner. As such magnetic powder, a substance that is magnetized in a magnetic field is used, and there are powders of ferromagnetic metals such as iron, cobalt, and nickel, and alloys and compounds such as magnetite, hematite, and ferrite. The content of the magnetic powder is preferably 15 to 70% by mass with respect to the toner mass. Magnetic powder is also useful as a colorant.

  The toner usually contains a wax for the purpose of improving releasability at the time of fixing and improving fixability. Examples of such waxes include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof, and the like. The derivatives are oxides, block copolymers with vinyl monomers, and graft modified products. In addition, alcohols, fatty acids, acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, mineral waxes, petrolactams and the like can also be used as waxes.

  In order to control the chargeability of the toner, a charge control agent may be used. Charge control agents include negative charge control agents and positive charge control agents.

  In order to control the toner to be negatively charged, for example, an organometallic complex or a chelate compound is effective. Specifically, a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid series, or the like. There are metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Further, as a substance for positively charging the toner, modified products such as nigrosine and fatty acid metal salts; quaternary ammonium such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc. Onium salts such as phosphonium salts and analogs thereof, and lake pigments thereof (the rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricia Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin Diorgano tin borate such as rate; guanidine compounds, and imidazole compounds.

  In the toner, a colorant, wax, and charge control agent are mixed with the binder resin for the toner described above, and magnetic powder is also blended, melt-kneaded, solidified, pulverized, and pulverized powder. Are classified by various methods. In addition, when the binder resin is dispersed and suspended in an aqueous system for polymerization, a colorant, wax, charge control agent and, if necessary, magnetic powder may be dispersed in the binder resin monomer composition.

  In addition, when toner is manufactured by a pulverization method, the pulverized fine powder is often indefinite and has poor properties as a toner. Therefore, after pulverization, spheroidization and surface smoothing may be performed by various methods. Is preferred.

  As a method of spheroidizing and surface smoothing, a method in which pulverized powder is placed in a high-speed air stream and made to collide with a blade, liner, casing, etc. to smooth or spheroidize the surface, or pulverized powder in warm water. There are a method for spheroidizing and spheroidizing, a method for exposing the pulverized powder to a hot air stream and spheroidizing.

  FIG. 8 shows an example of a surface modification device as an example. FIG. 8B is a view of the dispersion rotor as viewed from above.

  The surface reforming apparatus includes a casing 30, a jacket (not shown) through which cooling water or antifreeze liquid can be passed, a rectangular disk or a cylindrical pin 40 on the upper surface, which is attached to the central rotating shaft in the casing 30. A plurality of dispersion rotors 36 on a disk rotating at high speed, a liner 34 arranged at regular intervals from the outer periphery of the dispersion rotor 36, and a classification rotor for classifying the surface-modified toner powder into a predetermined particle size 31, a cold air introduction port 35 for introducing cold air, a raw material supply port 33 for introducing treatment raw material, and a discharge valve 38 installed so as to be openable and closable so that the surface modification time can be freely adjusted. The powder discharge port 37 and the cylindrical guide ring 39 are used to discharge the processed powder. The guide ring 39 includes a first space 41 that introduces particles to be treated into a space between the classification rotor 31 that is classification means, the dispersion rotor 36 that is surface modification means, and the liner 34, and fine powder in the classification means. The particles from which particles are removed are partitioned into a second space 42 for introducing the particles into the surface treatment means. A gap portion between the dispersion rotor 36 and the liner 34 is a surface modification zone, and the classification rotor 31 and its peripheral portion are classification zones.

  As shown in FIG. 8, the classifying rotor 31 may be installed vertically or horizontally. Moreover, the classification rotor 31 may be single or plural.

  In this surface reforming apparatus, when pulverized powder is introduced from the raw material supply port 33 with the discharge valve 38 closed, the crushed powder is first sucked by a blower (not shown) and classified by the classification rotor 31. The At that time, the fine powder is continuously discharged out of the apparatus, and the pulverized powder having a predetermined particle diameter or more is circulated by the dispersing rotor 36 along the inner periphery (second space 42) of the guide ring 39 by centrifugal force. It rides in the flow and is led to the surface modification zone. The raw material guided to the surface modification zone is subjected to a mechanical impact between the dispersion rotor 36 and the liner 34 and subjected to surface modification treatment. The surface-modified particles ride on the cold air passing through the apparatus, and are guided to the classification zone along the outer periphery (first space 41) of the guide ring 39. Therefore, the fine powder generated during the surface modification again is discharged out of the apparatus by the classification rotor 31. On the other hand, the treated pulverized powder having a predetermined particle size or more rides on the circulation flow again, returns to the surface modification zone, and repeatedly undergoes surface modification. After a certain period of time, the discharge valve 38 is opened, and the surface-modified particles are collected from the discharge port 37.

  Further, as a method for producing a spherical toner, there is a method in which a mixture containing a monomer as a toner binder resin as a main component is suspended in water and polymerized to form a toner. Generally, a monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer, a colorant, a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, a release agent, and other additives. Then, the monomer composition is dispersed in a continuous layer containing a dispersion stabilizer, for example, in an aqueous phase with an appropriate stirrer, and polymerized to obtain a desired particle size. A developer having is obtained.

  The toner obtained as described above is used by externally adding a powder such as an inorganic fine powder for the purpose of improving fluidity. Examples of such fine powder include silica fine powder, metal oxides such as alumina, titania, germanium oxide, and zirconium oxide; carbides such as silicon carbide and titanium carbide; inorganic fine powders such as nitrides such as silicon nitride and germanium nitride. Used.

  EXAMPLES Hereinafter, although a manufacture example and an Example demonstrate this invention concretely, this does not limit this invention at all.

  The physical properties related to the present invention were measured as follows.

(1) Particle size of toner (developer) As a measuring device, a particle size distribution measuring device “Coulter Counter TA-II type”, “Coulter Multisizer II” or “Coulter Multisizer III” (both trade names, Beckman Coulter Use). Further, as the electrolytic solution, reagent grade 1 sodium chloride is used, and an about 1% NaCl aqueous solution is prepared and used. A commercially available ISOTON-II (trade name, manufactured by Beckman Coulter, Inc.) can also be used as the electrolytic solution. As a measurement method, an appropriate amount of a surfactant (for example, alkylbenzene sulfonate) as a dispersant is added to 100 to 150 ml of the electrolytic solution (0.1 to 5 ml in a liquid form), and finally 2 to 20 mg of a measurement sample is added. . The electrolytic solution in which this sample is suspended is dispersed for 1 to 3 minutes with an ultrasonic disperser, set in a measuring cell of a measuring apparatus, and the volume and number are measured. A 100 μm aperture or a 30 μm aperture is used as the aperture. A volume distribution and a number distribution are calculated from the obtained volume and number, and a weight-based weight average particle diameter obtained from the volume distribution (the median value of each channel is a representative value for each channel) is obtained.

(2) Average Circularity of Developer Particles The average circularity of developer particles is measured using a flow type particle image measuring device “FPIA-2100 type” (trade name, manufactured by Sysmex Corporation), and the following formula is used. To calculate.
Equivalent circle diameter = 2 × (particle projected area / π) ^1/2
Circularity = (perimeter of a circle with the same area as the particle projection area) / (perimeter of the particle projection image)
Here, the “particle projected area” is the area of the binarized particle image, and “peripheral length of the particle projected image” is defined as the length of the contour line obtained by connecting the edge points of the particle image. The measurement is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm), and the peripheral length and area of the particle image when image processing is performed based on the resolution are used.

  The circularity in the present invention is an index indicating the degree of unevenness of toner particles, and is 1.000 when the toner particles are completely spherical, and the circularity becomes smaller as the surface shape becomes more complicated. The average circularity C, which means the average value of the circularity frequency distribution, is given by the following equation, where ci is the circularity (center value) at the division point i of circularity and mi is the number of particles contained in the division point i. Calculated from (I).

  In the measurement apparatus “FPIA-2100” used in the present invention, after calculating the circularity of each particle, the circularity of 0.4 to 1.0 is determined every 0.01 depending on the obtained circularity. The class is divided into equally divided classes, and the average circularity is calculated using the center value of the division points and the number of measured particles.

  Specifically, after adding a trace amount of a surfactant (for example, alkylbenzene sulfonate) as a dispersant to 10 ml of ion exchange water from which impure solids have been removed in advance, 0.02 g of a measurement sample is added, and an ultrasonic disperser is added. A measurement solution is prepared by performing a dispersion treatment for 2 minutes using “Tetora 150 type” (trade name, manufactured by Nikka Ki Bios Co., Ltd.). In this dispersion, the dispersion is appropriately cooled so that the temperature of the dispersion does not exceed 40 ° C. Moreover, in order to suppress the variation in circularity, the installation environment of the apparatus is controlled to 23 ° C. ± 0.5 ° C. so that the temperature in the analyzer is 26 to 27 ° C. In addition, automatic focus adjustment is performed using 2 μm latex particles at regular intervals (preferably every 2 hours).

  In measuring the circularity of the developer particles, the dispersion concentration is adjusted so that the particle concentration at the time of measurement is 30 million to 10,000 particles / μl, and then 1000 particles or more are measured. Thereafter, the average circularity is calculated as described above by excluding data with an equivalent circle diameter of less than 2 μm (to eliminate the influence of externally added particles).

(3) Roughness of developer carrier surface (Ra)
The surface of the developer carrying member is measured for arithmetic average roughness (Ra) using a surf coder SE-3500 (trade name) manufactured by Kosaka Laboratory based on JIS B0601 (2001). The measurement conditions are a cutoff of 0.8 mm, an evaluation length of 4 mm, and a feed rate of 0.5 mm / s. Ra on the surface of the developer carrying member is an average value of the measured values at a total of 9 points of 3 in the axial direction and 3 in the circumferential direction.

(4) Particle size of conductive particles The particle size of conductive particles such as graphite is measured using a laser diffraction particle size distribution meter (Coulter LS-230 particle size distribution meter (trade name) manufactured by Beckman Coulter, Inc.). . A small amount module is used for the measurement, and the solvent is isopropyl alcohol (IPA). The background function is executed after washing the measuring system of the measuring apparatus with IPA for about 5 minutes. Next, 1 to 25 mg of a measurement sample is added to 50 ml of IPA, and a sample solution prepared by dispersing for 1 to 3 minutes with an ultrasonic disperser is gradually added to the measurement system of the measurement apparatus, and PIDS on the screen of the apparatus is added. The measurement is performed after adjusting the sample concentration in the measurement system so as to be 45 to 55%, and the volume average particle diameter calculated from the volume distribution is obtained.

(5) Particle size of supported particles The particle size of the supported particles is measured using an electron microscope (manufactured by (trade name)). The shooting magnification is 60,000 times, and it is printed on a photograph. If it is difficult to obtain a print directly at 60,000 times, the photograph is enlarged and printed at 60,000 times after shooting at a low magnification. The major axis and minor axis of the primary particles are measured on the obtained print, and the average value is taken as the particle size of the measured particles. This particle size is determined for any 100 particles, and the 50% value is taken as the particle size of the supported particles.

(6) Measurement of electrification polarity of conductive coating layer and resin layer <Method for producing sample plate>
Apply a sample solution prepared by dissolving or dispersing the material used to form the conductive coating layer and resin layer to measure the charging polarity in an organic solvent with a bar coater (# 60), and then drying and heating. Thus, a sample plate having a resin layer with a thickness of about 20 μm is produced. For the measurement of the charging property, a sample plate is used that has been left to stand overnight at 23 ° C. and 60% RH in a state of being grounded.

<Method for adjusting carrier particles>
100 mesh pass-200 mesh-on spherical iron powder carrier (made by Dowa Iron Powder Co., Ltd., trade name: spherical iron powder DSP138) was left to stand overnight at 23 ° C. and 60% RH in a state of grounding. Use things.

<Measurement method>
The measurement is performed in an environment of 23 ° C. and 60% RH. The sample plate 83 produced by the above-described sample plate production method is set in the surface charge amount measuring apparatus TS-100AS (manufactured by Toshiba Chemical Co., Ltd.) shown in FIG. 9, and the electrometer 85 is grounded to make the value zero. The iron powder carrier 81 conditioned by the above carrier particle adjustment method is put in the dropping device 82, the START switch is pressed, and the iron powder carrier 81 is dropped on the sample plate 83 for 20 seconds, and is received by the receiver 84 which has been grounded in advance. . At this time, the polarity indicated by the electrometer 85 is read to obtain the charging polarity of the conductive coating layer and the resin layer with respect to the iron powder carrier. Reference numeral 86 denotes a condenser.

(7) Measurement of Charged Polarity of Supported Particles and Developer 0.2 g of supported particles left overnight in an environment of 23 ° C. and 60% RH was added to a spherical iron powder carrier of 100 mesh pass-200 mesh on (trade name) ; Put together with 10 g of spherical iron powder DSP138) into a jar with a polyethylene lid with an internal volume of about 50 ml and mix thoroughly. In addition, mixing is carried out by holding this wide-mouthed bowl up and down approximately 125 times (about 50 seconds).

  Next, about 2 g of this mixture was taken, and a 400-mesh screen 93 was provided on the bottom placed through an insulator on a suction machine 91 having a vacuum gauge 95, an air volume control valve 96 and a suction port 97 shown in FIG. A metal lid 94 is placed in a metal measuring vessel 92. Thereafter, suction is performed from the suction port 97 and the air volume control valve 96 is adjusted so that the pressure of the vacuum gauge 95 is 250 mmHg. In this state, suction is performed for 5 minutes to remove the supported particles by suction. At this time, the polarity indicated by the electrometer 99 connected to the measurement container 92 is read to obtain the charged polarity of the supported particles with respect to the iron powder carrier. Reference numeral 98 denotes a condenser. Here, when a developer is used instead of the supported particles, the charged electrode with respect to the iron powder carrier of the developer can be measured by this method.

  The developer used for evaluation of the developer carrying member in the present invention was manufactured as follows.

Production Example 1 (Production of Developer T1)
After thoroughly mixing 100 parts by mass of a styrene-butyl acrylate resin, 100 parts by mass of magnetite, 2 parts by mass of an azo iron complex compound (negatively chargeable charge control agent) and 5 parts by mass of low molecular weight polypropylene using a Henschel mixer, The mixture was melt kneaded and dispersed with a shaft extruder to obtain a kneaded product. After cooling this, it is coarsely pulverized with a cutter mill, then pulverized with a jet type pulverizer, and the resulting pulverized product is classified with a multi-division type classifier to obtain a fine powder having a weight average particle size of 5.9 μm. Got the body. 1 part by mass of hydrophobic colloidal silica was added to 100 parts by mass of the fine powder, and sufficiently mixed and dispersed with a Henschel mixer to produce a magnetic one-component developer T1.

Production Example 2 (Production of Developer T2)
100 parts by mass of a styrene-butyl acrylate resin, 95 parts by mass of magnetite, 2 parts by mass of an azo-based iron complex compound (negatively chargeable charge control agent) and 4 parts by mass of paraffin wax are sufficiently mixed with a Henschel mixer, and then biaxial. A kneaded product was obtained by melt-kneading and dispersing with a type extruder. After cooling this, it is coarsely pulverized with a cutter mill, then pulverized with a jet type pulverizer, and the resulting pulverized product is classified with a multi-division type classifier to obtain a fine powder having a weight average particle size of 6.6 μm. Got the body. The fine powder was subjected to spheronization and fine powder removal using a surface modification apparatus shown in FIG. The obtained fine powder after the spherical treatment had a weight average particle diameter measured by a Coulter counter method of 6.9 μm and a circularity of 0.959. 1 part by mass of hydrophobic colloidal silica was added to 100 parts by mass of the fine powder, and mixed and dispersed with a Henschel mixer to produce a magnetic one-component developer T2.

Production Example 3 (Production of Developer T3)
After thoroughly mixing 100 parts by weight of a polyester resin, 90 parts by weight of magnetite, 2 parts by weight of an azo-based iron complex compound (negatively chargeable charge control agent) and 4 parts by weight of Fischer-Tropsch wax with a Henschel mixer, a biaxial type A kneaded product was obtained by melt-kneading and dispersing with a loader. This was cooled and then coarsely pulverized with a cutter mill to obtain a coarsely pulverized product. The obtained coarsely pulverized product was mechanically pulverized with a mechanical pulverizer turbo mill (turbo industry, the surface of the rotor and stator being coated with chromium alloy plating containing chromium carbide). Finely pulverized, and the resulting finely pulverized product was classified using a multi-division classifier to obtain a fine powder having a weight average particle diameter of 6.4 μm. To 100 parts by mass of this fine powder, 1.5 parts by mass of hydrophobic colloidal silica treated with hexamethyldisilazane and dimethylsilicone oil and 0.5 parts by mass of strontium titanate are added, and mixed and dispersed with a Henschel mixer. A magnetic one-component developer T3 was produced.

Production Example 4 (Production of Developer T4)
After thoroughly mixing 100 parts by weight of a polyester resin, 95 parts by weight of magnetite, 2 parts by weight of an azo iron complex compound (negatively chargeable charge control agent) and 3 parts by weight of a polyethylene wax with a Henschel mixer, a biaxial type A kneaded product was obtained by melt-kneading and dispersing with a loader. After cooling this, coarsely pulverizing with a cutter mill, and then pulverizing with a jet type pulverizer, then classifying the resulting finely pulverized product with a multi-division type classification device, A fine powder having a diameter of 7.1 μm and a circularity of 0.925 was obtained. 1 part by mass of hydrophobic colloidal silica was added to 100 parts by mass of the fine powder, and mixed and dispersed with a Henschel mixer to obtain a magnetic one-component developer T4.

Production Example 5 (Production of developer T5)
After thoroughly mixing 100 parts by mass of styrene-butyl acrylate resin, 95 parts by mass of magnetite, 3 parts by mass of imidazole compound (positive charge control agent) and 4 parts by mass of polyethylene wax with a Henschel mixer, biaxial type A kneaded product was obtained by melt-kneading and dispersing with a loader. After cooling this, coarsely pulverizing with a cutter mill, and then pulverizing with a jet type pulverizer, then classifying the resulting finely pulverized product with a multi-division type classification device, A fine powder having a diameter of 6.4 μm and a circularity of 0.924 was obtained. To 100 parts by mass of this fine powder, 1.2 parts by mass of colloidal silica treated with an aminosilane coupling agent and amino-modified silicone oil and 2.5 parts by mass of strontium titanate fine powder are added and mixed in a Henschel mixer. Dispersion was carried out to produce a magnetic one-component developer T5.

  The conductive spherical particles arranged to form the unevenness of the conductive coating layer were produced as follows.

Production Example 6 <Production of Spherical Particle P-1>
Rykai machine (automatic mortar, manufactured by Ishikawa Plant Co., Ltd.) with 14 parts by mass of coal-based bulk mesophase pitch powder (volume average particle size 2 μm or less) to 100 parts by mass of spherical phenol resin particles (volume average particle size 5.8 μm) Used to coat uniformly. Next, after heat stabilization treatment at 280 ° C. in the air, it was calcined and graphitized at 2000 ° C. in a nitrogen atmosphere, and then classified, and spherical particles P-1 having a volume average particle size of 6.0 μm (spherical conductive carbon particles) ) Was manufactured.

Production Example 7 <Production of Spherical Particle P-2>
Produces spherical particles P-2 (spherical conductive carbon particles) having a volume average particle size of 12.5 μm in the same manner as in the conductive spherical particle production example 6 except that the spherical phenol resin particles have a volume average particle size of 12.2 μm. did.

Production Example 8 <Production of Resin Composition V9 Formed on Surface of Conductive Coating Layer>
300 parts by mass of methanol, 100 parts by mass of toluene, 468 parts by mass of styrene, 90 parts by mass of 2-ethylhexyl acrylate, 42 parts by mass of 2-acrylamido-2-methylpropanesulfonic acid, and 6 parts by mass of lauroyl peroxide were stirred and a temperature measuring device. The mixture was charged in a flask equipped with a nitrogen introducing device and held at 65 ° C. for 10 hours under a nitrogen atmosphere to conduct a polymerization reaction. The obtained polymer was dried under reduced pressure and pulverized to obtain a resin composition V9 having a weight average molecular weight of 8,000.

  Table 4 shows the resin composition formed on the surface of the conductive coating layer in this example.

  Table 5 shows particles carried on the developer carrying member in this example.

Example 1
440 parts by mass of a resol-type phenolic resin (Mw 1700 produced using ammonia as a catalyst, 50% methanol solution) is diluted with IPA, and 80 parts by mass of crystalline graphite (volume average particle size 5.8 μm) and conductivity While adding 20 parts by mass of carbon black and dispersing in a sand mill using glass beads having a diameter of 1 mm as media particles, conductive spherical particles P-1 dispersed in IPA (produced in Production Example 6) 20 masses A coating liquid was prepared by further adding sand mill dispersion. IPA used a total of 430 parts by mass.

Put the prepared coating liquid in the spray gun reservoir, stand vertically and rotate at a constant speed, while lowering the spray gun at a constant speed on an aluminum cylindrical tube with an outer diameter of 16 mmφ with the upper and lower ends masked Spray coating was performed so that the coat width was 220 mm in the longitudinal direction to form a coating liquid layer. Subsequently, the coating liquid layer was cured by heating at 160 ° C. for 20 minutes in a hot air drying furnace, to produce a developer carrier A4 having a conductive coating layer. The adhesion weight after drying of the conductive coating layer at this time was 1.05 × 10 ⁻⁴ kg. Further, the surface roughness (Ra) of the developer carrier A4 was 1.07 μm.

Next, the resin composition V1 shown in Table 4 was dissolved in a mixed solvent of chlorobenzene and ethyl acetate so as to have a solid content of 25%, and the deposited amount was 1.5 g / m on the conductive coating layer of the developer carrier A4. ² was applied by a spray method. Subsequently, a developer carrier A2 in which a resin layer made of the resin composition V1 was formed on the conductive coating layer was produced by heating and drying in a hot air drying oven at 150 ° C. for 30 minutes. The developer carrying member A2 had a surface roughness Ra of 1.03 μm. In addition, this resin composition V1 shows a positive charge polarity.

  Next, PMMA particles (primary average particle size 4.6 μm, particle R1 in Table 5) were applied as carrier particles onto the resin layer of developer carrier A2 using the lubricant application device shown in FIG. That is, the coated particles were applied to a sponge roller, and the coated particles were brought into contact with the developer carrier A2 to transfer and apply the coated particles to the developer carrier. The developer carrier to which the PMMA particles are attached is referred to as “developer carrier A1”. The charged polarity of the particle R1 is positive. When the hardness of the resin layer of the developer carrier A1 was measured by removing the carrier particles, the pencil hardness was HB.

  The performance evaluation of the produced developer carrying member was performed as follows using a laser beam printer “LBP1760” (manufactured by Canon Inc.).

  The developer regulating blade was incorporated into a process cartridge “EP-52” modified to a urethane specification, after attaching a magnet and a flange so that the produced developer carrying member could be incorporated into the modified cartridge. Thereafter, the developer produced above suitable for the developer carrying member is filled in the cartridge and attached to the printer, and the low temperature and low humidity environment (15 ° C./10% RH, L / L), the normal temperature and normal humidity environment (23 C./50% RH, N / N) or high temperature and high humidity environment (30.degree. C./85% RH, H / H). Test images corresponding to the following evaluation items were output after 10 images, 100 images, 500 images, 1000 images, 2000 images, and 10,000 images, and evaluation images were created and evaluated.

[1] 5 black corner image density A 5 mm square (or 5 mm circle) solid black is output at each location of the character pattern (or character chart), and the image density at 10 predetermined locations is measured by a reflection densitometer RD918. The average value was defined as 5 black corner image density.

[2] Solid black image density Solid black was output, and the image density at 10 predetermined locations was measured with a reflection densitometer in the same manner as the 5 black corner image density, and the average value was defined as the solid black image density. Even if the 5 black corner image density is excellent, depending on the state of the toner carried on the developer carrier (friction charge amount, developer carrying amount), the developer to be developed is insufficient, and the 5 black corner image The value may be smaller than the concentration.

[3] Sleeve ghost In the output image of the printer (image chart in the case of a copying machine), a solid black image (such as ●) is placed at equal intervals on a white background in the area corresponding to one round of the sleeve at the tip of the image. Other than that, halftones were used, and the following ranking was performed according to how the ghost of the hieroglyph images appeared on the halftones. A positive ghost indicates a ghost having a higher image density than that of a halftone, and a negative ghost indicates a ghost whose image density is lower than that of a halftone, but is not distinguished in the determination.
A: No difference in shading is observed.
B: A slight shade difference can be confirmed depending on the viewing angle.
C: A ghost is clearly confirmed visually. Practical lower limit.
D: A ghost can be clearly confirmed as shading. The density difference can be measured with a reflection densitometer. Not practical.
E: A ghost appears over two or more sleeves.

[4] Image Unevenness A linear or belt-like streak (shading difference) that outputs halftone and solid black and runs in the image traveling direction was evaluated according to the following criteria. The image density unevenness generated based on sleeve ghost and blotch (described later) was excluded and evaluated.
A: Neither image nor sleeve can be confirmed at all.
B: A slight density difference can be confirmed on the halftone image, but there is no problem on the solid black image.
C: Although the density difference is slight on the solid black image, a streak or band in which the density difference can be visually confirmed is confirmed on the halftone image. Practical lower limit.
D: A density difference that can be clearly measured with a reflection densitometer appears as a streak or a band on the halftone image. A density difference can be visually confirmed even on a solid black image. This is a problem level for graphic images.
E: Appears as a solid black image in a solid black image.

[5] Blotch A solid black image and a halftone image are output, and a blotch (spotted, rippled, or carpet-like) image that is likely to be generated due to excessive charging of toner in each image is visually observed and evaluated according to the following criteria. did.
A: No blotch is observed on the image or on the developer carrying member (observed when the developer is coated).
B: Slight blotch is confirmed on the developer carrying member, but no influence is exerted on the image.
C: A blotch image appears slightly on the halftone image. Practical lower limit.
D: A clear blotch appears on a halftone image or a solid black image. Not practical.
E: Blotch appears almost on the entire surface.

  Table 6 shows the constitution of developer carrier A1 and the types of developers used for evaluation. Moreover, the result of each said evaluation in each environment is shown to Tables 7-9.

Comparative Example 1
The same evaluation as in Example 1 was performed using the developer carrier A2, that is, without attaching the carrier particles. Table 6 shows the constitution and developer of developer carrier A2, and Tables 7 to 9 show the evaluation results.

Comparative Example 2
Without providing a resin layer on the developer carrier A4, the carrier particles R1 are applied in the same manner as in Example 1 to produce a developer carrier A3. Using this, the same evaluation as in Example 1 is performed. It was. Table 6 shows the configuration of the developer carrier A3, and Tables 7 to 9 show the evaluation results.

Comparative Example 3
The same evaluation as in Example 1 was performed using the developer carrier A4, that is, without the resin layer and the carrier particles. Table 6 shows the constitution of the developer carrying member A4 and the developer, and Tables 4 to 6 show the evaluation results.

In addition, a measurement relating to the charge amount of the developer was also performed. That is, in the L / L environment and the H / H environment, the developer carriers A1 to A4 are separately manufactured, and at the time of the 100th sheet from the start of image output, on the photoreceptor, A solid black image was prepared, the apparatus was stopped in the middle of the image output, and the developer carried on the developer carrying member was collected by suction with a metal cylindrical tube and a cylindrical filter. At that time, the charge amount Q stored in the condenser through the metal cylindrical tube, the mass M of the collected developer, and the area S where the toner was sucked were measured. From these values, the charge amount per unit weight Q / M (mC / kg) (development charge amount) and developer transport amount M / S (dg / m ² ) were calculated. These results are shown in Table 10.

  In the initial stage of image output, the developer carrier A1 (Example 1) did not cause a decrease in image density in any environment, and neither image unevenness nor ghost occurred. On the other hand, in the developer carrier A2 (Comparative Example 1) and the developer carrier A3 (Comparative Example 2), an image density decrease, image unevenness, and a ghost image occur in the environment L / L, and the H / H environment Also, the density reduction and image unevenness of the solid black image occurred at the initial stage of image output. In the developer carrier A4 (Comparative Example 3), ghosts were observed in both L / L and H / H environments at the initial stage of image output, and a decrease in density was also observed. However, in any developer carrier, the image defect was improved as the number of images printed increased, and good images were obtained after 2000 images were printed (Example 1, Comparative Examples 1 to 3).

  Further, as shown in Table 10, in the developer carriers A2 to A4, the developer transport amount (M / S) despite the high charge amount (Q / M) of the developer in the environment L / L. Is a low value. This is thought to be due to a charge-up phenomenon.

  That is, in the developer carriers A2 to A4, the developer present on the developer carrier is attracted strongly on the developer carrier because the charge amount is too high in the lower layer portion, and the developer is charged in the upper layer of the developer. Therefore, it is difficult for the upper layer developer to be developed (transferred) onto the photoconductor, thereby reducing the M / S on the photoconductor. In particular, in the developer carrier A2, the resin layer V1 is positively charged, and in the developer carrier A3, the carrier particles R1 are weakly positively charged. An excessive and non-uniform charge is imparted to the developer, and the above-described image defects such as a decrease in initial image density, image unevenness, and blotch are remarkably exhibited.

  On the other hand, it can be seen that the developer carrier A1 has appropriate Q / M and M / S. This is because the charge polarity of the resin layer V1 on the developer carrier and the carrier particle R1 is the same polarity, so that the carrier particles are not excessively charged by friction and sufficient and appropriate triboelectric charge is imparted to the initial developer. It is presumed that this is because it can be done.

  Further, in the H / H environment, there is a slight decrease in the triboelectric chargeability of the developer. In particular, in the developer carrier A4, sufficient initial developability is not obtained because the initial triboelectric chargeability is insufficient.

  As the durability test proceeds, the developer is stirred and frictional charging is repeatedly performed, and as a result, an appropriate amount of frictional charge can be maintained. That is, the developer carrying bodies A1 to A4 were used to print up to 2000 images, and when the developer was suctioned and observed from the developer carrying body, almost no carried particles were seen therein. Further, observation was also made on the developer carrying member after the developer was collected by suction, but no carried particles were observed, and almost no resin layer remained.

Example 2
400 parts by mass of a resol-type phenolic resin (Mw 1700 manufactured using ammonia as a catalyst, 50% methanol solution) is diluted with methanol, and 80 parts by mass of crystalline graphite (volume average particle size 5.4 μm) and conductivity While adding 20 parts by mass of carbon black and dispersing in a sand mill using glass beads having a diameter of 1 mm as media particles, 20 parts by mass of spherical particles P-2 (produced in Production Example 7) and the following formula A dispersion in which 10 parts by mass of the quaternary ammonium salt compound represented by (A) was dispersed was further subjected to sand mill dispersion to obtain a coating solution. The added methanol was 250 parts by mass.

The coating solution was applied on an aluminum cylindrical tube having an outer diameter of 20 mmφ using a spray method so that the coating width was 315 mm in the longitudinal direction, and then heated in a hot air drying furnace at 160 ° C. for 20 minutes, Developer carrier B7 having a conductive coating layer was produced. At this time, the weight of the conductive coating layer after drying was 1.82 × 10 ⁻⁴ kg. The developer carrier B7 had a surface roughness Ra of 1.40 μm.

Next, the resin composition V2 (methyl methacrylate / dimethylaminoethyl methacrylate copolymer (molar ratio 90:10)) in Table 4 was dissolved in ethyl acetate so as to have a solid content of 40%. On the conductive coating layer, it is applied by a spray method so as to have an adhesion amount of 1.2 g / m ² , followed by drying by heating at 150 ° C. for 30 minutes in a hot air drying oven, and developer carrier B1 'Made. The surface roughness Ra of the developer carrier B1 ′ was 1.33 μm.

  Melamine-formaldehyde resin particles (primary average particle size 5.7 μm) (particles R2 in Table 5) were applied on the surface of this developer carrier B1 ′ in the same manner as in Example 1 to produce developer carrier B1. In addition, when the hardness of the resin layer of developer carrier B1 was measured, it was B in pencil hardness.

  A magnet and a flange were attached so that the developer carrier B1 could be attached to a process cartridge for a printer LaserJet 9000 (manufactured by Hewlett Packard), and attached to the process cartridge. The hopper of this process cartridge was filled with developer T2 (manufactured in Production Example 2) and incorporated into a LaserJet 9000 machine for image output. In addition, the same evaluation as Example 1 was performed at the time of 10 sheets, 100 sheets, 500 sheets, 1000 sheets, 3000 sheets, and 30000 sheets. Table 11 shows the constitution of the developer carrier B1 and the developer, and Tables 12 to 14 show the evaluation results.

Example 3
A developer carrier B2 was produced in the same manner as in Example 2 except that boron nitride particles (primary average particle size 5.8 μm) (particles R3 in Table 5) as carrier particles were used. The produced developer carrying member B2 was evaluated in the same manner as in Example 2. Table 11 shows the constitution of the developer carrier B2 and the developer, and Tables 12 to 14 show the evaluation results.

Example 4
On the conductive coating layer of developer carrier B7 produced in Example 2, PMMA resin (resin composition V3 in Table 4) was dissolved in toluene so as to have a solid content of 30%. It was applied by a spray method so as to be m ^2, and then dried by heating at 150 ° C. for 30 minutes in a hot air drying oven to prepare a developer carrier B3 ′. The developer carrier B3 ′ had a surface roughness Ra of 1.35 μm.

  Hereinafter, in the same manner as in Example 2, the carrier particles R2 were applied onto the resin layer of the developer carrier B3 'to produce a developer carrier B3. The hardness of the resin layer of this developer carrier B3 was F. The same evaluation as in Example 2 was performed on the created developer carrier B3. Table 11 shows the constitution of the developer carrier B3 and the developer, and Tables 12 to 14 show the evaluation results.

Example 5
100 parts by mass of methyl methacrylate-dimethylaminoethyl methacrylate copolymer (same as V2) is added to toluene so that the solid content is 30% by mass on the conductive coating layer of developer carrier B7 produced in Example 2. Dissolve, put 25 parts by mass of conductive carbon black in it, and apply a coating liquid (resin composition V4 in Table 4) prepared by dispersing it in a sand mill using 1 mm diameter glass beads as media particles. It apply | coated by the spray method so that it might become the amount of 1.2 g / m < ² >. Subsequently, it was dried by heating at 150 ° C. for 30 minutes in a hot air drying furnace, to produce a developer carrier B4 ′. The developer carrier B4 ′ had a surface roughness Ra of 1.39 μm.

  Thereafter, the carrier particles R2 were applied onto the resin layer of the developer carrier B4 'in the same manner as in Example 2 to produce a developer carrier B4. The hardness of the resin layer of this developer carrier B4 was F. The produced developer carrier B4 was evaluated in the same manner as in Example 2. Table 11 shows the constitution of the developer carrier B5 and the developer, and Tables 12 to 14 show the evaluation results.

Comparative Example 4
A developer carrier B5 was produced in the same manner as in Example 2 except that the supported particles were titanium oxide particles (primary average particle size 3.1 μm) (particles R4 in Table 5) having a negative charge polarity. The produced developer carrier B5 was evaluated in the same manner as in Example 2. Table 11 shows the constitution of the developer carrier B5 and the developer, and Tables 12 to 14 show the evaluation results.

Comparative Example 5
On the conductive coating layer of the developer carrier B7 produced in Example 2, a polyester resin having a negative charge polarity (resin composition V5 in Table 4) was dissolved in toluene so as to have a solid content of 30%. It apply | coated by the spray method so that it might become 1.3 g / m < ² > of adhesion amounts. Subsequently, it was dried by heating at 150 ° C. for 30 minutes in a hot air drying furnace, to produce developer carrier B6 ′. The developer carrier B6 ′ had a surface roughness Ra of 1.33 μm.

  Subsequently, the carrier particles R2 were applied to the developer carrier B6 'in the same manner as in Example 2 to produce a developer carrier B6. The hardness of the resin layer of this developer carrier B6 was HB. The produced developer carrier B6 was evaluated in the same manner as in Example 2. Table 11 shows the constitution of the developer carrier B6 and the developer, and Tables 12 to 14 show the evaluation results.

Comparative Example 6
The developer carrying member B7 produced in Example 2 was mounted on the process cartridge as it was, and the same evaluation as in Example 2 was performed. Table 11 shows the configuration of the developer carrier B7 and the developer, and Tables 12 to 14 show the evaluation results.

  The toner particles that have been spheroidized have a smoother surface than the pulverized toner particles, and it is observed that the magnetic material is likely to be encapsulated. With this effect, it is possible to suppress the consumption of the developer.

  However, the charge amount of the developer may become too high, resulting in charge-up. Therefore, the charge of the developer may be locally increased, and the charge distribution may be non-uniform. As a result, image defects such as density unevenness are likely to occur.

  In Examples 2 to 5, in order to compensate for this disadvantage, a coating liquid in which a phenol resin is mixed with a quaternary ammonium salt compound is applied as a developer carrier for the purpose of suppressing the triboelectric charge to the developer to some extent. The one having a conductive coating layer formed by thermosetting was used.

  Due to the effect of mixing this quaternary ammonium salt compound, it is possible to cope with problems such as a charge-up phenomenon due to an endurance test. However, even in this system, the initial triboelectric charge is unstable, and as a result, the ghost and image unevenness at the initial stage of image generation as seen in Comparative Examples 4 to 6 occur.

  For example, in the developer carrier B6 (Comparative Example 5), if the resin layer provided on the conductive coating layer is negatively charged and the carrier particles applied thereon are positively charged, these charges are charged. Since the polarities are different, the supported particles are excessively triboelectrically charged, and a charge-up phenomenon occurs particularly in the L / L environment. As a result, image density reduction, image unevenness, sleeve ghost, and blotch are observed. On the contrary, in the developer carrier B5 (Comparative Example 4), the resin layer is positively charged and the carrier particles are negatively charged. Therefore, the frictional charge imparting force to the developer is weakened, and in the L / L environment Image unevenness occurred, and initial density thinness and sleeve ghost were remarkable in the H / H environment. Also in the developer carrier B7 (Comparative Example 6), image unevenness and sleeve ghost occurred in the L / L environment and the H / H environment because the frictional charging at the initial stage of image output was unstable.

  Compared to this, as in the developer carriers B1 to B4 (Examples 2 to 5), since the charging polarity of the resin layer and the supporting particles are the same, negative chargeability to the developer at the initial stage of image output Granting can be performed appropriately. In particular, since the developer carrier B4 (Example 5) has a conductive resin layer, the carrier particles can be appropriately charged and good results are obtained.

Example 6
460 parts by mass of a resol-type phenolic resin (Mw = 1700 produced using ammonia as a catalyst, 50% methanol solution) is diluted with methanol, and 80 parts by mass of crystalline graphite (volume average particle size 5.4 μm) is contained therein. 20 parts by mass of conductive carbon black is added and dispersed in a sand mill using glass beads having a diameter of 1 mm as media particles, 20 parts by mass of spherical particles P-1 (produced in Production Example 6) and the following formula 10 parts by mass of the quaternary ammonium salt compound represented by (B) was dispersed in methanol and added, and further sand mill dispersion was performed to obtain a coating solution. The added methanol was 250 parts by mass.

The coating liquid was applied on an aluminum cylindrical tube having an outer diameter of 20 mmφ by using a spray method so that the coating width was 220 mm in the longitudinal direction, and then heated in a hot air drying furnace at 160 ° C. for 20 minutes, A developer carrying member C4 having a conductive coating layer was produced. At this time, the weight of the conductive coating layer after drying was 1.45 × 10 ⁻⁴ kg. Further, the surface roughness Ra of the developer carrier C4 was 1.04 μm.

Next, a copolymer of quaternary ammonium group-containing vinyl and methyl methacrylate (resin composition V6 in Table 4) is dissolved in ethyl acetate so as to have a solid content of 40%. On the coating layer, the coating amount is 1.4 g / m ² by spraying, followed by drying by heating in a hot air drying oven at 150 ° C. for 30 minutes to obtain developer carrier C1 ′. Produced. The developer carrying member C1 ′ had a surface roughness Ra of 1.01 μm.

  Further, the silicone resin particles (primary average particle diameter 7.1 μm) (particles R5 in Table 5) surface-treated with an aminosilane coupling agent as the support particles are treated on the surface of the developer support C1 ′ in the same manner as in Example 1. To give a developer carrier C1. The hardness of the resin layer of this developer carrying member C1 was B.

  A magnet and a flange are attached to the developer carrier C1, a process cartridge for a printer LaserJet 4200 (manufactured by Hewlett Packard) is mounted, and then the developer T3 manufactured in Production Example 3 is filled in the hopper of this process cartridge, and the printer LaserJet 4200 is filled. After incorporation, the image was printed out, and the same evaluation as in Example 1 was performed at the time of printing 10, 100, 500, 1000, 3000, and 12000 sheets. Table 15 shows the composition and developer of the produced developer carrying member C1, and Tables 16 to 18 show the evaluation results.

Comparative Example 7
A bisphenol A type epoxy resin (resin composition V7 in Table 4) was used as the material of the resin layer formed on the conductive coating layer of the developer carrying member C4 produced in Example 6, and this was obtained with a solid content of 30%. So that it is dissolved in toluene and applied on the conductive coating layer of the developer carrying member C4 by a spray method so as to have an adhesion amount of 1.3 g / m ² , followed by 150 ° C. in a hot air drying furnace. A developer carrying member C3 ′ was produced by heating for 30 minutes to cure. The developer carrying member C3 ′ had a surface roughness Ra of 1.05 μm.

  Next, in the same manner as in Example 6, the carrier particles R5 were applied on the resin layer of the developer carrier C3 'to produce a developer carrier C3. The hardness of the coating layer of this developer carrying member C3 was 3H. The produced developer carrying member C3 was evaluated in the same manner as in Example 6. Table 15 shows the configuration of the developer carrying member C3 and the developer, and Tables 16 to 18 show the evaluation results.

Comparative Example 8
The developer carrying member C4 produced in Example 6 was mounted on the process cartridge as it was, and the same evaluation as in Example 6 was performed. Table 15 shows the configuration of the developer carrying member C4 and the developer, and Tables 16 to 18 show the evaluation results.

Example 7
After washing, aluminum zinc tube (surface roughness Ra = 1.15 μm) with an outer diameter of 20 mmφ surface-blasted with # 150 spherical glass beads was first treated with zincate, and then zinc was adhered. The cylindrical tube was immersed in a molybdic acid solution to form a molybdenum plating layer having a film thickness of 6 μm, and a developer carrying member C5 was produced. The developer carrier C5 had a surface roughness Ra of 1.10 μm. For the zincate treatment, a commercially available zincate treatment agent (manufactured by Nippon Kanisen Co., Ltd., trade name: Schuma K-102) was used.

  On the molybdenum plating layer of this developer carrier C5, the resin composition V6 was applied in the same manner as in Example 6, and then the carrier particles R5 were carried to produce a developer carrier C2. The hardness of the resin layer of this developer carrying member C2 was B. The produced developer carrying member C2 was evaluated in the same manner as in Example 6. Table 15 shows the configuration of the developer carrying member C2 and the developer, and Tables 16 to 18 show the evaluation results.

Comparative Example 9
The developer carrier C5 produced in Example 7 was mounted on the process cartridge as it was, and the same evaluation as in Example 6 was performed. Table 15 shows the configuration of the developer carrying member C5 and the developer, and Tables 16 to 18 show the evaluation results.

  Developer (toner) particles produced using a mechanical pulverizer are not as spheroidized, but are slightly spheroidized compared to those produced using an airflow pulverizer. Because it is in a state close to that given, charging up is likely to occur.

  In Example 6 and Comparative Examples 7 and 8, a conductive coating layer formed by mixing a quaternary ammonium salt compound with a phenol resin was used. However, in this system, it is possible to cope with problems such as a charge-up phenomenon due to an endurance test, but frictional charging at the initial stage of image output tends to become unstable. As a result, in the developer carrying member C4 (Comparative Example 8), ghost and image unevenness occur at the initial stage of image output. On the other hand, in the developer carrying member C1 (Example 6), such a problem at the initial stage of image output did not occur. Regarding the developer carrier C3 (Comparative Example 7), since the resin layer V7 has a high hardness, the resin layer does not disappear from the surface of the developer carrier even when the image is advanced. During this period, the triboelectric charge of the developer tends to gradually increase, and in particular in the environment L / L, blotch occurred due to charge-up in the vicinity of 3000 sheets.

  The developer carrying member C5 whose conductive coating layer is a molybdenum plating layer can adjust the triboelectric chargeability of the developer and suppress the occurrence of charge-up, but it is particularly effective in environment H / H. The initial triboelectric chargeability is insufficient (Comparative Example 9). In Example 7 (developer carrier C2), since the triboelectric chargeability is good even in the environment H / H of the carrier particles R5, it was possible to compensate for a decrease in image performance at the initial stage of image output.

Example 8
500 parts by mass of a resol-type phenolic resin (Mw = 1700 produced using ammonia as a catalyst, 50% methanol solution) is diluted with IPA, and 80 parts by mass of crystalline graphite (volume average particle size 5.4 μm) and 20 parts by mass of conductive carbon black is added, and 10 parts by mass of conductive spherical particles P-1 (produced in Production Example 6) are dispersed in a sand mill using glass beads having a diameter of 1 mm as media particles. The dispersion was added to IPA and further subjected to sand mill dispersion to obtain a coating solution. The IPA used was 250 parts by mass.

The above coating solution is applied onto an aluminum cylindrical tube having an outer diameter of 24.5 mmφ by using a spray method so that the coat width is 310 mm in the longitudinal direction, followed by 160 ° C. for 20 minutes in a hot air drying furnace. A developer carrier D3 having a conductive coating layer was prepared by heat curing. At this time, the weight of the conductive coating layer after drying was 2.61 × 10 ⁻⁴ kg. Further, the surface roughness Ra of the developer carrier D3 was 0.69 μm.

Next, a polymer containing imidazolium salts (resin composition V8 in Table 4) is dissolved in a mixed solvent of chlorobenzene and ethyl acetate so as to have a solid content of 25%, and a conductive coating of developer carrier D3 is obtained. The developer is applied on the layer by a spraying method so that the amount of adhesion is 1.2 g / m ^2, and then dried by heating at 150 ° C. for 30 minutes in a hot air drying furnace to produce a developer carrier D1 ′. did. The developer carrier D1 ′ had a surface roughness Ra of 0.67 μm.

  Further, the carrier particles R1 were applied on the resin layer of the developer carrier D1 'in the same manner as in Example 1 to produce a developer carrier D1. The hardness of the resin layer of this developer carrier D1 was B.

  A magnet and a flange are attached to the developer carrier D1 and mounted on a developing device for a digital copying machine IR-6000 (manufactured by Canon Inc.). The developer T4 manufactured in Manufacturing Example 4 is filled in the hopper of this developing device. Then, the image was printed out, and the same evaluation as in Example 1 was performed at the time of printing 10, 100, 1000, 3000, and 30000 sheets. Table 19 shows the configuration of the developer carrier D1 and the developer, and Tables 20 to 22 show the evaluation results.

Comparative Example 10
The developer carrying member D3 produced in Example 8 was mounted on the developing device as it was, and the same evaluation as in Example 8 was performed. Table 19 shows the configuration of the developer carrier D3 and the developer, and Tables 20 to 22 show the evaluation results.

Example 9
After washing an aluminum cylindrical tube (surface roughness Ra = 0.72 μm) with an outer diameter of 24.5 mmφ blasted with spherical glass beads of # 200, zincate was applied to the zinc tube, and then the cylindrical tube was A developer carrying body D4 was manufactured by immersing in a Ni-P solution to form an electroless Ni-P plating layer having a film thickness of 6 μm (P concentration in the plating layer was 10.3% by mass). The developer carrier D4 had a surface roughness Ra of 0.64 μm. A commercially available zincate treatment agent (manufactured by Nippon Kanisen Co., Ltd., trade name: Schuma K-102) was used for the zincate treatment, and a commercially available plating solution (Nihon Kanisen Co., Ltd.) was used to form the electroless Ni-P plating layer. Product name; S-754).

  A resin layer of the resin composition V8 was formed on the Ni—P plating layer of the developer carrier D4 in the same manner as in Example 8, and then the carrier particles R5 were carried to produce a developer carrier D2. The hardness of the coating layer of this developer carrier D2 was B. Hereinafter, the same evaluation as in Example 8 was performed. Table 19 shows the configuration and developer of developer carrier D2, and Tables 20 to 22 show the evaluation results.

Comparative Example 11
The developer carrier D4 produced in Example 9 was mounted on the developing device as it was, and the same evaluation as in Example 9 was performed. Table 19 shows the configuration and developer of developer carrier D4, and Tables 20 to 22 show the evaluation results.

  The developing device for IR-6000 used for the evaluation here is a developing device having a magnetic regulating blade shown in FIG. 6, and this magnetic regulating blade is spaced apart from the developer carrier at a constant interval. Is provided. Even in such a developing device, an image defect may occur due to charge-up in the early stage of image output. In the developer carrier D3 (Comparative Example 10), some initial blotches were observed. In addition, the developer carrier (D4) in which the conductive coating layer is a Ni-P plating layer is excellent in durability, but is likely to be charged up at the initial stage of image formation. In the developer carrier D4 (Comparative Example 11), the occurrence of blotch was remarkable at the initial stage of image printing under the environment L / L, and the image density was also lowered. On the other hand, in the developer carrying bodies D1 (Example 8) and D2 (Example 9) using the same polarity resin layer and carrier particles, no defect was observed in the initial image.

Example 10
500 parts by mass of a resol-type phenolic resin (Mw = 1700 produced using ammonia as a catalyst, 50% methanol solution) is diluted with methanol, and 80 parts by mass of crystalline graphite (volume average particle size 5.8 μm) is diluted therein. And 20 parts by mass of conductive carbon black, and dispersed in a sand mill using glass beads having a diameter of 1 mm as media particles, 70 parts by mass of spherical particles P-1 (produced in Production Example 6) and the above formula A dispersion in which 70 parts by mass of the quaternary ammonium salt compound represented by (A) was dispersed in methanol was added, followed by sand mill dispersion to prepare a coating solution. The added methanol was 250 parts by mass.

This coating solution is applied on an aluminum cylindrical tube having an outer diameter of 32 mmφ by a spray method so that the coat width is 220 mm in the longitudinal direction, and then heated and cured in a hot air drying oven at 160 ° C. for 20 minutes. Thus, a developer carrier E2 having a conductive coating layer was produced. At this time, the weight of the conductive coating layer after drying was 3.96 × 10 ⁻⁴ kg. Further, the surface roughness Ra of the developer carrying member E2 was 0.69 μm.

Next, the sulfonic acid-containing copolymer produced in Production Example 8 (resin composition V9 in Table 4) was dissolved in toluene so as to have a solid content of 30%, and the conductivity of the developer carrier E2 produced as described above was obtained. On the coating layer, it was applied by a spray method so as to have an adhesion amount of 1.1 g / m ^2, and then heated and dried in a hot air drying oven at 150 ° C. for 30 minutes to prepare a developer carrier E1 ′. The developer carrying member E1 ′ had a surface roughness Ra of 0.66 μm.

  Further, polyvinylidene fluoride resin particles (primary average particle size 5.3 μm) (particles R6 in Table 5) as support particles were applied to the surface of the developer support E1 ′ in the same manner as in Example 1, and developed. An agent carrier E1 was produced. The hardness of the resin layer of this developer carrying member E1 was B.

  A magnet and a flange are attached to the developer carrier E1 and mounted on a developing device for a digital copying machine GP-605 (manufactured by Canon Inc.), and the developer T5 produced in Production Example 5 is filled in the hopper of this developing device. Then, the image was printed out, and the same evaluation as in Example 1 was performed at the time of printing 10, 100, 1000, 3000, and 30000 sheets. Table 23 shows the configuration of the developer carrier E1 and the developer, and Table 24 shows the evaluation results.

Comparative Example 12
The developer carrying member E2 produced in Example 10 was mounted on the developing device as it was, and the same evaluation as in Example 10 was performed. Table 23 shows the configuration of the developer carrier E2 and the developer, and Table 24 shows the evaluation results.

  A positively chargeable developer usually uses only a positively chargeable charge control agent (charge control resin), a positively chargeable external additive, etc. as a material that is easily positively charged in the developer material. For this reason, in a developing device using a positively chargeable developer, ghosts and blotches due to charge-up hardly occur. Therefore, in Example 10 and Comparative Example 12, for the purpose of increasing the triboelectric charge amount of the positively chargeable developer, a conductive coating layer obtained by adding a quaternary ammonium salt compound to a phenol resin is used. The developer carrying member was configured so as to have negative chargeability by the action. In the developer carrier having such a conductive coating layer, in some cases, the conductive crystalline graphite is present on the surface in part in the unused state, but in part, the crystalline resin covers the binder resin. It has been broken. Therefore, even if an attempt is made to increase the triboelectric charge amount of the positively chargeable developer by adding a quaternary ammonium salt to the resin coating layer, if the developer carrier has insufficient conductivity, it is sufficient for the developer. May not be able to hold a positive charge.

  In the developer carrying member E2 (Comparative Example 12), since the rise of the image density was slow at the initial stage of image output, streaks were generated in the halftone or solid black image, and in addition, ghost was also observed. This is because the triboelectric charge amount of the positively chargeable developer is insufficient. On the other hand, as in the developer carrier E1 (Example 10), the coating particles R6 and the resin composition V9, both of which are negatively chargeable, are applied to the surface of the developer carrier, so that it can be carried even at the initial stage of image output. Appropriate positive chargeability was imparted to the developer via the particles R6, and the above phenomenon could be suppressed. Usually, the resin conductive coating layer wears the resin on the surface by durable use, and the probability of existence of crystalline graphite on the surface of the developer carrier increases, so that conductivity is ensured and sufficient image performance is obtained. become.

It is a schematic diagram which shows the cross section of a developing agent carrier. FIG. 4 is a schematic diagram illustrating a state in the vicinity of a developer carrier and a developer layer thickness regulating member. It is a schematic diagram which shows the example of a blasting apparatus. It is a schematic diagram which shows the example of the application means of a coating particle. It is a schematic diagram which shows an example of a developing device. It is a schematic diagram which shows an example of a developing device. It is a schematic diagram which shows an example of a developing device. It is a schematic sectional drawing of an example of the surface modification apparatus of a developer particle. It is a schematic explanatory drawing for measuring the charging polarity of a conductive coating layer and a resin layer. It is a schematic explanatory drawing for measuring the charge polarity of a covering particle.

Explanation of symbols

1 Electrostatic latent image carrier (photosensitive drum)
2 Developer layer thickness regulating member (magnetic blade)
3 Container (hopper)
4 Developer magnetic toner 5 Multipolar magnet (magnet roller)
6 Substrate (metal cylindrical tube)
7 Conductive coating layer 8 Developer carrier (developing sleeve)
9 Power supply 10 Stirring blade 11 Developer layer thickness regulating agent (elastic blade)
26 Sponge roller 26a Sponge layer 26b Sponge roller shaft 27 Developer carrier (developing sleeve)
28 Coating container 29 Coating (supporting) particle 30 Casing 31 Classification rotor 32 Fine powder collection port 33 Raw material supply port 34 Liner 35 Cold air introduction port 36 Dispersion rotor 37 Product discharge port 38 Discharge valve 39 Guide ring 40 Square disk 41 First space 42 Second space 81 Iron powder carrier 82 Dropper 83 Sample plate 84 Receptor 85 Electrometer 86 Condenser 91 Suction machine 92 Measuring vessel 93 Mesh screen 94 Metal lid 95 Vacuum gauge 96 Air volume control valve 97 Suction port 98 Condenser 99 Potential Total 100 Turntable 101 Blast nozzle 102 Nozzle holder 103 Gas flow path 104 Blast material flow path 105 Screw 106 Blast material 107 Masking jig 108 Developer carrier (development sleeve)
109 Ball screw 110 Fixing base 300 Developing sleeve 301 Developer layer thickness regulating member 302 Base 303 Magnet roller 304 Conductive coating layer 306 Concavity / convexity imparting particle 307 Lubricating particle 308 Conductive agent 309 Binder resin 310 Carrier particle 311 Developer (toner)
312 Resin layer

Claims (8)

  A developer carrier having at least a conductive coating layer provided on a substrate, wherein a resin layer that is worn by use on the conductive coating layer is partially or entirely formed.   The developer carrier according to claim 1, wherein the resin layer has a hardness (pencil hardness) of H or less.   The developer carrying member according to claim 1, wherein the resin layer is conductive.   The developer carrying member according to any one of claims 1 to 3, wherein the resin layer is coated with fine particles having the same charging polarity with respect to the iron powder as the resin layer. Image information is formed as an electrostatic latent image on the electrostatic image carrier, a magnetic one-component developer is supplied to the formed electrostatic latent image by a developer carrier, and the electrostatic latent image is used as a developer image. An image forming method for visualizing and then transferring the developer image onto a recording material, melting and solidifying the developer, and fixing the image on the recording material,
The developer carrying member is provided with a conductive coating layer on a cylindrical substrate, and a resin layer that is worn by use on the conductive coating layer is formed in part or on the entire surface.
And at least on the surface of the developer carrying member or the contact surface of the developer layer thickness regulating member with the developer carrying member, fine particles having the same charging polarity with respect to the iron powder as the resin layer are carried. An image forming method.   The image forming method according to claim 5, wherein the resin layer has a hardness (pencil hardness) of H or less.   The image forming method according to claim 5, wherein the resin layer is conductive.   The image forming method according to any one of claims 5 to 7, wherein fine particles having the same charging polarity with respect to the iron powder as the resin layer on the surface of the developer carrying member are carried on the surface of the developer carrying member.

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