JP2010210795A - Developer carrier and developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier allowing uniform distribution of triboelectric charge amount of toner on the developer carrier, stable image density in durable use, and suppressing image failures such as ghost or density unevenness. <P>SOLUTION: The developer carrier 105 comprises a substrate 102 and a resin layer 101, wherein the resin layer contains at least polyethylene imine, and conductive ceramic particles. A developing device has the developer carrier. It is preferable that the polyethylene imine is alkyl isocyanate modified polyethylene imine, the resin layer contains phenolic resin, and the conductive ceramic particles are boron carbide or silicon carbide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developer carrier used in an image forming apparatus using electrophotography such as a copying machine and a printer, and a developing device using the same.

As a developer carrier used in an electrophotographic image forming method, Patent Document 1 proposes a developer carrier having a surface layer made of a thermosetting resin containing a fibrous conductive agent. The developer carrying member contains a fibrous conductive agent in the surface layer, whereby the wear resistance of the surface layer is improved.
Patent Document 2 proposes a developer carrier having a surface layer containing particles having a Mohs hardness of 6 or more and a charge control agent.

  By the way, with recent demands for higher image quality and improved toner transfer efficiency, finely divided and spherical toners are increasingly used. However, such a toner tends to have an excessive charge due to frictional charging. In addition, the triboelectric charge amount tends to be non-uniform. For this reason, non-uniform density (hereinafter sometimes referred to as “image density unevenness” in some cases), ghost, and the like are likely to occur in a halftone image. Here, the ghost is a phenomenon in which the previous latent image remains in the image to which the toner is to be transferred, and the image appears white or appears black. In addition, in order to improve the image quality, it is necessary to make the toner triboelectric charge distribution more stable and make the volume resistance value more uniform for the purpose of faithfully developing the electrostatic latent image. It has become. Therefore, a developer carrier that further stabilizes the ability to impart triboelectric charge to the toner is desired.

Japanese Patent Laid-Open No. 60-230175 JP 2005-140915 A

  The object of the present invention is to develop a toner that has a uniform triboelectric charge distribution on the developer carrier, has a stable image density throughout its durable use, and can suppress the occurrence of image defects such as ghosts and uneven image density. The object is to provide an agent carrier. Another object of the present invention is to provide a developing device that can provide an electrophotographic image in which the image density is stable throughout durable use and image defects such as ghosts and image density unevenness are suppressed.

  The developer carrier according to the present invention has a base and a resin layer, and the resin layer contains at least polyethyleneimine and conductive ceramic particles. Further, the developing device according to the present invention includes a negatively charged developer having toner particles, a container containing the developer, a developer carrier for carrying and transporting the developer stored in the container, A developing device having a developer layer thickness regulating member for forming a developer layer on the developer carrier, wherein the developer carrier is the developer carrier described above. Features.

  According to the present invention, there is provided a developer carrying member having high durability and capable of controlling the triboelectric charge amount of a negative triboelectric developer to a moderately high level and uniformly. Further, the volume resistance value of the resin layer can be uniformly controlled by the synergistic effect of the polyethyleneimine and the conductive ceramic particles. As a result, it is easy to control the abrasion resistance of the resin layer, the volume resistance value, and the triboelectric charge amount of the developer, the image density is stable throughout the endurance use, and image defects such as ghost and image density unevenness are prevented. Occurrence can be suppressed.

1 is a schematic configuration diagram showing an example in which a developing device of the present invention is applied to a magnetic one-component contact developing device. FIG. 2 is a schematic configuration diagram illustrating an example in which the developing device of the present invention is applied to a magnetic one-component non-contact developing device. 1 is a schematic configuration diagram showing an example in which a developing device of the present invention is applied to a non-magnetic one-component non-contact developing device. 1 is a schematic configuration diagram illustrating an example in which a developing device of the present invention is applied to a two-component developing device.

  The developer carrying member of the present invention has a substrate and a resin layer. This resin layer is usually disposed on the surface of the substrate. Further, this resin layer contains at least polyethyleneimine and conductive ceramic particles. When the polyethyleneimine used in the present invention is contained in the resin layer, the triboelectric charge amount of the negative triboelectric developer can be improved. Furthermore, since polyethyleneimine has electrical conductivity, the volume resistance value of the resin layer can be controlled to be low and uniform. As a result, excessive frictional charging of the developer is prevented during durable use, the image density is easily stabilized, and the occurrence of ghost is easily suppressed.

  The polyethyleneimine is preferably an alkyl isocyanate-modified polyethyleneimine containing units represented by the following general formulas (1) and (2). When the polyethyleneimine is an alkyl isocyanate-modified polyethyleneimine, the effect of improving the triboelectric charge amount of the negative triboelectric developer is further enhanced. Further, the volume resistance value of the resin layer is more easily made uniform due to a synergistic effect with the conductive ceramic particles. As a result, the image density tends to be more stable during durable use.

  The alkyl isocyanate-modified polyethyleneimine can be obtained, for example, by subjecting a commercially available polyethyleneimine (Epomin (trade name), manufactured by Nippon Shokubai Co., Ltd.) to an alkyl isocyanate addition reaction. As the alkyl group of the alkyl isocyanate to be subjected to the addition reaction, the following alkyl groups having 8 to 20 carbon atoms are preferable. An octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an eicosyl group. The alkyl group may be a straight chain or a branched structure, but a linear alkyl group that is excellent in flexibility is preferred. When the carbon number of the alkyl group of the alkyl isocyanate is 8 or more, it is easy to obtain an effect of further enhancing the tribocharging property of the negatively chargeable developer. Further, the volume resistance value of the resin layer is more easily made uniform due to a synergistic effect with the conductive ceramic particles. As a result, the image density is easily stabilized. When the carbon number of the alkyl group of the alkyl isocyanate is 20 or less, the compatibility is easily improved when a resin other than polyethyleneimine is contained in the resin layer. Further, the volume resistance value of the resin layer is more easily made uniform due to a synergistic effect with the conductive ceramic particles. As a result, image density unevenness hardly occurs.

The addition rate of alkyl isocyanate is preferably 0.8 to 1.3 molar equivalents relative to the amine value of polyethyleneimine. When the addition ratio is 0.8 molar equivalent or more, the effect of further enhancing the tribocharging property of the negatively chargeable developer is easily obtained, and the image density is easily stabilized. Further, when the addition rate is 1.3 molar equivalents or less, unreacted alkyl isocyanate is less likely to bleed out over time, and other members are less likely to be contaminated.
The weight average molecular weight of polyethyleneimine is preferably 300 to 10,000. When the weight average molecular weight is 300 or more, the triboelectric charge amount of the negatively chargeable developer is easily improved, and the image density is easily stabilized during durable use. When the weight average molecular weight is 10,000 or less, when a resin other than polyethyleneimine is contained in the resin layer, compatibility is likely to be improved and image density unevenness is less likely to occur.

The conductive ceramic particles used in the present invention can improve the wear resistance of the resin layer by being contained in the resin layer. Moreover, the volume resistance value of the resin layer can be further reduced uniformly due to the synergistic effect with polyethyleneimine. As a result, the image density is likely to be stabilized during durable use, and the occurrence of ghosts is easily suppressed. The electrical resistivity of the conductive ceramic particles is preferably 10 ⁶ Ω · cm or less. If the electrical resistivity is 10 ⁶ Ω · cm or less, the volume resistance value of the resin layer can be easily controlled to be low, so that it is easy to suppress the occurrence of ghosts. Further, since the volume resistance value of the resin layer can be easily controlled uniformly, it is easy to suppress the occurrence of image density unevenness. Examples of the conductive ceramic particles include carbide ceramic particles such as boron carbide, silicon carbide, and titanium carbide. Among these, boron carbide and silicon carbide are preferable because they have a relatively low specific gravity and are therefore easily present uniformly in the resin layer and easily suppress uneven image density.

  The primary average particle diameter of the conductive ceramic particles is preferably 0.3 μm or more and 3.0 μm or less. By setting the primary average particle size to 0.3 μm or more, the abrasion resistance of the resin layer can be further improved, and the image density is likely to be stable throughout durable use. By setting the primary average particle size to 3.0 μm or less, the conductive ceramic particles are likely to be uniformly present in the resin layer, and image density unevenness is easily suppressed. The content of the conductive ceramic particles in the resin layer is preferably 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin component such as polyethyleneimine or phenol resin. By setting the amount to 5 parts by mass or more, it is easy to improve the wear resistance of the resin layer, and the image density is likely to be stabilized during durable use. By setting it to 20 parts by mass or less, the conductive ceramic particles are likely to be uniformly present in the resin layer, and image density unevenness is easily suppressed.

  The conductive ceramic particles are preferably substantially spherical. By making it substantially spherical, it becomes easy to exist uniformly in the resin layer, and it becomes easy to suppress image density unevenness. In addition, substantially spherical means that the ratio of the major axis / minor axis of the particles is 1.0 to 2.0. In the present invention, it is more preferable to use substantially spherical particles having a major axis / minor axis ratio of 1.0 to 1.5.

  In order to contain a resin other than polyethyleneimine in the resin layer and improve the abrasion resistance of the resin layer, it is preferable to use a phenol resin. As content of a phenol resin and polyethyleneimine, it is preferable that content of polyethyleneimine is 0.1 mass part or more and 10 mass parts or less with respect to 100 mass parts of phenol resins. By setting the content of polyethyleneimine to 10 parts by mass or less, the effect of wear resistance due to the inclusion of the phenolic resin is easily obtained, and further, the polyethyleneimine is easily present uniformly in the phenolic resin. As a result, the image density is likely to be stabilized during durable use, and image density unevenness is less likely to occur. By setting the polyethyleneimine content to 0.1 parts by mass or more, the triboelectric charge amount of the negatively chargeable developer can be easily improved, and the image density can be easily stabilized. As the phenol resin, a resol type phenol resin is preferable in that it easily improves the wear resistance of the resin layer.

The volume resistance value of the resin layer is preferably 10 ⁴ Ω · cm or less, more preferably 10 ⁻³ Ω · cm or more and 10 ³ Ω · cm or less. When the volume resistance value of the resin layer is 10 ⁴ Ω · cm or less, it is effective for suppressing the occurrence of ghost. As a method for adjusting the volume resistance value of the resin layer, there is a method in which another conductive agent is dispersed and contained in the resin layer in combination with the conductive ceramic particles. As the other conductive agent, conductive fine particles having a number average particle diameter of 1 μm or less, preferably 0.01 to 0.8 μm are used. By setting the number average particle size of the conductive fine particles to 1 μm or less, it is easy to uniformly control the volume resistance value of the resin layer and to suppress the generation of ghost.

  Moreover, the following are mentioned as a material of a electrically conductive agent. Fine powder of metal powder such as aluminum, copper, nickel, silver, antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide, metal oxide such as potassium titanate, carbon fiber, furnace black, lamp Carbon black such as black, thermal black, acetylene black and channel black, and carbide such as graphite. Among these, in the present invention, carbon black, particularly conductive amorphous carbon is preferably used. This is because carbon black is particularly excellent in electrical conductivity, and can be obtained to some extent by simply filling the polymer material with conductivity or controlling the amount of addition.

  Moreover, you may control the volume resistance value of a resin layer using 2 or more types of these electrically conductive agents. When two or more kinds of conductive agents are used, graphitized particles such as carbon black and graphite are preferable. When carbon black and graphitized particles are used as a conductive agent, it is easy to obtain a resin layer having a uniform volume resistance and good conductivity. Furthermore, since the surface roughness of the developer carrying member can be obtained to some extent, the triboelectric charging property of the toner on the developer carrying member can be easily controlled uniformly. Moreover, it is preferable that the addition amount of these electrically conductive agents suitable in this invention shall be the range of 1 mass part-100 mass parts with respect to 100 mass parts of resin components, such as a polyethyleneimine and a phenol resin. It becomes easy to control the volume resistance value of a resin layer to a desired level as it is 1 mass part or more. When the amount is 100 parts by mass or less, it is easy to suppress a decrease in the strength (wear resistance) of the resin layer, which is likely to occur particularly when a fine powder having a particle size on the order of submicron is used. Although the preferred range of the surface roughness of the resin layer varies depending on the development method, it is generally preferred that the arithmetic average roughness Ra (JIS B0601 (2001)) is 0.15 μm to 3.00 μm. When Ra is 0.15 μm or more, the developer transport amount can be sufficient, so that the occurrence of image defects due to insufficient image density due to insufficient developer transport amount and uneven coating of the developer coat layer can be prevented. easy. Further, when Ra is 3.00 μm or less, the developer conveyance amount is stabilized, and triboelectric charging can be performed so that the toner triboelectric charge distribution is uniform.

  As the surface roughness of the resin layer, a measurement value obtained by a measurement method according to JIS B0601 (2001) can be adopted. As a method of setting the roughness of the resin layer to a desired value, a surface roughness is imparted to the substrate by sandblasting, and a resin layer is formed thereon, or a surface roughness is obtained by adding irregularities-providing particles to the resin layer. There is a way to get it. From the viewpoint of controlling the surface roughness at a low surface cost and durability of the surface roughness, a method of incorporating the unevenness-imparting particles in the resin layer is preferable. By adding irregularity-providing particles, the surface of the resin layer of the developer carrier is maintained at an appropriate surface roughness to improve developer transport, increase the chance of contact between the developer and the resin layer, and friction It becomes easy to improve the chargeability.

  As the irregularity imparting particles, in order to form appropriate irregularities on the surface of the resin layer, the volume average particle diameter is preferably 1 to 20 μm, and more preferably 2 to 10 μm. If the volume average particle size is 1 μm or more, an appropriate surface roughness can be imparted to the resin layer even if the content is small. If the volume average particle size of the unevenness imparting particles is 20 μm or less, the surface roughness of the resin layer becomes nonuniform and the roughness becomes too large to prevent the developer from being insufficiently triboelectrically charged, It is possible to suppress deterioration in image quality such as fogging and low density in the obtained image. As such unevenness-imparting particles, resin particles, metal oxide particles, carbonized particles, and the like can be used, and as the unevenness-imparting particles, a spherical shape or a similar shape is uniform in the resin layer. Since it becomes easy to disperse | distribute, it is preferable. The measured value measured using the laser diffraction type particle size distribution meter can be employ | adopted for the volume average particle diameter of uneven | corrugated provision particle | grains.

  Examples of the substrate of the developer carrying member used in the present invention include a cylindrical member, a columnar member, and a belt-like member. Among them, a rigid cylindrical tube or a solid rod such as a metal is preferable because it has excellent processing accuracy and durability. As such a substrate, a non-magnetic metal or alloy such as aluminum, stainless steel, or brass formed into a cylindrical shape or a cylindrical shape and subjected to processing such as polishing or grinding is preferably used. Moreover, you may use what formed the rubber layer or the resin layer on the said base | substrate as a base | substrate. These substrates are used after being molded or processed with high accuracy in order to improve the uniformity of the image. For example, the straightness in the longitudinal direction is preferably 30 μm or less, preferably 20 μm or less, more preferably 10 μm or less. As the runout of the gap between the developer carrying member and the photosensitive drum, the runout of the gap between the vertical surface when the developer sleeve is rotated by abutting the vertical surface with a uniform spacer is 30 μm or less, preferably It is preferably 20 μm or less, more preferably 10 μm or less. Aluminum is preferably used for the substrate because of material cost and ease of processing.

  Next, a method for producing a developer carrying member by forming a resin layer on the surface of the substrate will be described. The resin layer can be formed, for example, by dispersing and mixing the respective raw material components in a solvent to form a paint, coating the substrate, drying and solidifying or curing. First, 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 dispersing and mixing the respective raw material components in the paint. At this time, the particle diameter of the beads is preferably 0.8 mm or less in order to uniformly disperse and mix each component in the coating liquid, and more preferably 0.6 mm or less. In addition, as a method of applying the obtained paint to the substrate, known methods such as dipping method, spray method, roll coating method can be applied, but in order to make each component in the resin layer uniform, spraying is possible. The method is preferred. Furthermore, the film thickness of the resin layer is preferably 50 μm or less, more preferably 40 μm or less, and further preferably 4 μm to 30 μm because it is easy to form a uniform film thickness.

  The developing device includes a negatively chargeable developer having toner particles, a container containing the developer, the developer carrier, and a developer layer thickness for forming a developer layer on the developer carrier. And a regulating member. In the present invention, any of a non-contact developing device and a contact developing device using a magnetic one-component developer or a non-magnetic one-component developer, a developing device using a two-component developer, and the like can be used. In particular, the present invention relates to non-contact type development such as a magnetic one-component non-contact type developing device and a non-magnetic one-component non-contact type developing device having a tendency to vary in the charge amount of the developer on the developer carrying member. Effective for the device.

  An example in which the developing device of the present invention is applied to a magnetic one-component non-contact developing device is shown in the schematic block diagram of FIG. The developing device carries and conveys a container (developing container 109) for containing the developer and a magnetic one-component developer (not shown) (also referred to as toner) having magnetic toner particles stored in the container. The developer carrying member 105 of the present invention. The developer carrying member 105 is provided with a developing sleeve 103 in which a resin layer 101 is coated on a metal cylindrical tube serving as a base 102, and a magnet (magnet roller) 104 is disposed inside the developing sleeve 103, and toner is placed on the surface. Are magnetically guided and held on the surface. On the other hand, the electrostatic latent image carrier, for example, the photosensitive drum 106 rotates in the direction of arrow B, and the development on the developer carrier 105 is performed in the development region D where the developer carrier 105 and the photosensitive drum 106 face each other. The agent is attached to the electrostatic latent image to form a toner image.

  A developing method in such a developing apparatus will be described below. Toner is fed into the developer container 109 from a developer supply container (not shown) via a developer supply member (such as a screw) 118. The developing container 109 is divided into a first chamber 112 and a second chamber 111, and the toner sent to the first chamber 112 passes through a gap formed by the developing container 109 and the partition member 113 by the stirring and conveying member 110. To the second chamber 111. A stirring member 114 is provided in the second chamber 111 to prevent the developer from staying.

  A magnetic blade 107 as a developer layer thickness regulating member is attached to the developer container so as to face the developer carrier 105 with a gap of about 50 μm or more and 500 μm or less. The magnetic force lines from the magnetic pole N 1 of the magnet roller 104 are concentrated between the magnetic blades, and the developer carrying member rotates in the direction of arrow A to form a thin layer of toner on the developer carrying member 105. Instead of the magnetic blade 107, a nonmagnetic developer layer thickness regulating member may be used. The toner obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 106 by friction between the toner layers and between the resin layers 101 on the surface of the developer carrier 105. The thickness of the toner layer formed on the developer carrier 105 is preferably thinner than the minimum gap between the developer carrier 105 and the photosensitive drum 106 in the development region D.

  Further, in order to cause the toner carried on the developer carrying member 105 to fly to the electrostatic latent image on the photosensitive drum and develop it, a developing bias voltage is applied to the developer carrying member 105 from the developing bias power source 108. Is preferred. When a DC voltage is used as the developing bias voltage applied to the developer carrier 105, a voltage corresponding to an intermediate value between the electrostatic latent image potential and the background potential is preferable. In order to increase the density of the developed image and improve the gradation, an alternating bias voltage may be applied to the developer carrier 105 to form an oscillating electric field whose direction is alternately reversed in the development region D. . Also in this case, the voltage applied to the developer carrying member 105 is preferably an alternating bias voltage in which a DC voltage component corresponding to an intermediate value between the electrostatic latent image potential and the background potential is superimposed. At this time, in the case of so-called regular development in which toner is attached to a high-potential electrostatic latent image, a magnetic one-component developer that is frictionally charged to a polarity opposite to the polarity of the electrostatic latent image is used. In the case of so-called reversal development in which toner is attached to a low-potential electrostatic latent image, a magnetic one-component developer that is frictionally charged to the same polarity as that of the electrostatic latent image is used. Here, the high potential and the low potential are expressions based on absolute values.

  FIG. 2 shows another example in which the developing device of the present invention is applied to a magnetic one-component non-contact type developing device. The developing device shown in FIG. 2 includes an elastic blade 215 made of an elastic plate made of rubber such as urethane rubber or silicone rubber, or metal such as phosphor bronze or stainless steel. The elastic blade 215 is brought into contact with or pressed against the developer carrying member 205 via a magnetic one-component developer, and the developer is subjected to development more strongly than the non-contact type developing device shown in FIG. A thin layer is formed on the agent carrier 205. In this type of developing device, the toner is easily affected by non-uniform conductivity on the surface of the developer carrier, and the toner layer on the developer carrier varies in the amount of triboelectric charge, resulting in a broad triboelectric charge amount distribution. Prone. However, even in such a developing apparatus, by using the developer carrier of the present invention, since the conductivity of the surface of the developer carrier is uniform, the toner triboelectric charge distribution can be sharpened.

  Here, the contact pressure of the elastic blade 215 with respect to the developer carrier 205 is a linear pressure of 4.9 N / m or more and 49 N / m or less, so that the regulation of the toner is stabilized and the thickness of the toner layer is preferable. It is preferable in that it can be regulated. When the contact pressure of the elastic blade 215 is set to a linear pressure of 4.9 N / m or more, the thickness of the toner layer formed on the developer carrying member can be controlled with high precision, and fog and magnetic properties are obtained in the obtained image. Occurrence of component developer leakage can be suppressed. Further, when the linear pressure is 49 N / m or less, the rubbing force of the magnetic one-component developer becomes an appropriate level, and it is possible to prevent toner deterioration and fusion to the developer carrier 205 and the elastic blade 215. . Although the above example is a magnetic one-component non-contact type, the developing device of the present invention has a layer thickness of the magnetic one-component developer on the developer carrying member between the developer carrying member and the photosensitive drum in the developing region D. The present invention can be suitably applied to a magnetic one-component contact type developing device formed with a thickness equal to or greater than the gap distance between them.

  FIG. 3 shows another example in which the developing device of the present invention is applied to a non-magnetic one-component non-contact developing device. In the developing device shown in FIG. 3, an electrostatic latent image carrier that carries an electrostatic latent image, for example, a photosensitive drum 306 is rotated in the arrow B direction. A developing sleeve 303 as a developer carrying member is composed of a base (metal cylindrical tube) 302 and a resin layer 301 formed on the surface thereof. A columnar member can be used in place of the metal cylindrical tube as the substrate, and since a non-magnetic one-component developer is used, no magnet is provided inside the substrate 302.

  A developing method in such a developing apparatus will be described below. In the developing container 309, an agitating / conveying member 310 for agitating and conveying a non-magnetic one-component developer 317 (also referred to as toner) is provided. Further, a developer supply / peeling member (developer supply / peeling member) for supplying the developer to the development sleeve 303 and stripping off the toner remaining on the surface of the development sleeve 303 after development in the developing container. Roller) 316 is provided in contact with the developing sleeve 303. When the member 316 rotates in the same direction as or opposite to the developing sleeve 303, the toner remaining on the developing sleeve 303 is peeled off in the developing container 309, and new toner is supplied. The developing sleeve 303 carries the supplied toner and rotates in the direction of arrow A to convey the toner to the developing area D where the developing sleeve 303 and the photosensitive drum 306 face each other. The toner carried on the developing sleeve 303 is pressed against the surface of the developing sleeve 303 by the developer layer thickness regulating member 315, and the thickness thereof is formed constant. The toner is charged enough to develop the electrostatic latent image on the photosensitive drum 306 by friction between the toner, the developing sleeve 303, and the developer layer thickness regulating member 315. The thickness of the toner layer formed on the developing sleeve 303 is preferably thinner than the minimum gap between the developing sleeve 303 and the photosensitive drum 306 in the developing portion. The present invention is particularly effective for such a non-contact type developing apparatus.

  In order to cause the toner carried on the developing sleeve 303 to fly to the electrostatic latent image on the photosensitive drum and develop the toner, it is preferable to apply a developing bias voltage from the developing bias power source 308 to the developing sleeve. The development bias voltage may be either a DC voltage or an alternating bias voltage, and the voltage is preferably the same voltage as described above. As the developer supply / peeling member 316, for example, an elastic roller such as resin, rubber, or sponge, a belt, a brush member, or the like can be used. When the elastic roller is used, the rotation direction of the developing sleeve 303 can be selected appropriately in the same direction or in the opposite direction. Usually, the rotation in the same direction (the direction of arrow C) can be peeled off. And preferred in terms of supply. The penetration amount of the elastic roller with respect to the developing sleeve 303 is preferably 0.5 mm or more and 2.5 mm or less in terms of developer supply and stripping properties. When the intrusion amount of the elastic roller is 0.5 mm or more, the peelability is improved and the occurrence of ghost can be suppressed. When the intrusion amount is 2.5 mm or less, there is little stress on the toner, and toner deterioration, fusing and fogging can be suppressed.

  The elastic blade 315 preferably has the same material and the same curved shape as the elastic blade 215 of the magnetic one-component non-contact type developing device shown in FIG. 2 and is installed so as to be pressed against the developing sleeve 303. The elastic blade 315 has a structure in which a polyamide elastomer (PAE) is attached to the surface of a phosphor bronze plate that can obtain a stable pressurizing force, particularly for a stable regulation force and a stable (negative) triboelectric chargeability to the toner. It is preferable to use those. Examples of the polyamide elastomer (PAE) include a copolymer of polyamide and polyether. The contact of the elastic blade 315 with the developing sleeve 303 is preferably based on the same contact force as that of the elastic blade 215 with respect to the developer carrier 205 in the magnetic one-component non-contact type shown in FIG. In the developing device of the present invention, the non-magnetic one-component developer on the developing sleeve has a non-magnetic one-component developer having a thickness greater than or equal to the gap distance between the developing sleeve and the photosensitive drum in the developing region D. The present invention can also be suitably applied to a component contact type developing device.

  FIG. 4 shows another example in which the developing device of the present invention is applied to a two-component developing device. The developing device shown in FIG. 4 uses a two-component developer containing a magnetic carrier and a toner, and supplies the toner to the electrostatic latent image on the photosensitive drum 406 to develop the two-component magnetic brush developing type reversal developing device. It is. The developing sleeve 403 as a developer carrying member has a base body 402 made of a metal cylinder such as aluminum and a resin layer 401, and a part of the outer peripheral surface thereof is exposed to the outside so that it can be rotated in the developing container 409. It is installed. A magnet roller 404 is inserted into the developing sleeve 403 and is fixed by supporting the developing sleeve, and a developer is formed on the surface of the developing sleeve like a brush. In the developing container, a coating blade 419 is installed so that the tip thereof faces the developing sleeve 403. Inside the developing container 409, a developer stirring member 414 is stored on the bottom side, and replenishment toner is stored on the upper side. A toner hopper 420 is provided.

  Reference numeral 423 denotes a charging device that uniformly charges the peripheral surface of the photosensitive drum 406. In this example, the charging device is a magnetic brush type charging device. A magnetic brush made of magnetic particles 421 is formed on the surface of the conveying sleeve 423 as a charging device by the magnetic force of the magnet roller 422, and the magnetic brush is brought into contact with the surface of the photosensitive drum 406 to charge the photosensitive drum 406. . Note that a charging bias is applied to the transport sleeve 423 by bias applying means (not shown). In the developing container 409, a two-component developer (not shown) of a mixture of toner and magnetic carrier is accommodated and stirred by the developer agitating member 414 so that the toner has a negative polarity mainly due to rubbing with the magnetic carrier. Is triboelectrically charged. The toner present in the vicinity of the developing sleeve 403 is also frictionally charged by sliding with the developing sleeve 403. A part of the developer in the developing container 409 adheres to the surface of the developing sleeve due to the magnetic force of the magnet roller 404 in the developing sleeve, and the magnetic brush layer adjusted to a predetermined thickness by the coating blade 419 is rotated with the rotation of the developing brush. It is sequentially formed on the top and conveyed to the developing unit.

  The developing sleeve 403 is disposed so as to face the photosensitive drum 406 with an SD gap, and a developing portion is formed in the SD gap. The SD gap preferably has a distance that can prevent the carrier from adhering to the photosensitive drum and improve the dot reproducibility. Specifically, the SD gap is preferably 100 μm or more and 1000 μm or less, for example, 350 μm. can do. When the SD gap is 100 μm or more, it is possible to keep the density of an image obtained by sufficiently supplying the toner to the photosensitive drum. Further, if the SD gap is 1000 μm or less, the density of the magnetic lines of force of the magnet roller can be kept high in the developing unit, the carrier is restrained to suppress adhesion to the photosensitive drum, and deterioration of dot reproducibility is suppressed. be able to. The developing sleeve 403 is rotationally driven in the same direction as the photosensitive drum 406, and the magnetic brush layer comes into contact with the surface of the photosensitive drum 406 in the developing portion and rubs the photosensitive drum surface appropriately.

  In this two-component developing device, it is preferable to apply a developing bias having an oscillating voltage obtained by superimposing a DC voltage (Vdc) and an AC voltage (Vac) to the developing sleeve 403. The voltage between the peaks of the oscillating voltage is preferably 300 V to 3000 V, and the frequency is 500 Hz to 10000 Hz, preferably 1000 Hz to 7000 Hz, which can be appropriately selected depending on the process. In this case, a triangular wave, a rectangular wave, a sine wave, a waveform with a changed duty ratio, an intermittent alternating superimposed electric field, or the like can be selected and used as the waveform. The toner from the magnetic brush layer conveyed to the developing unit by the rotating developing sleeve 403 adheres to the electrostatic latent image formed on the photosensitive drum 406 by the electric field due to the developing bias, and the electrostatic latent image is developed as a toner image. Is done. In addition, when an electrostatic latent image on the surface of the photosensitive drum 406 is formed as an exposure bright portion, toner is attached to the low potential electrostatic latent image and reversal development is performed.

  The toner remaining on the developing sleeve 403 that has passed through the developing portion is continuously returned to the developer reservoir in the developing container 409 as the developing sleeve 403 rotates. In order to maintain the toner concentration of the two-component developer in the developing container 409 within a predetermined range, the toner concentration is detected by a toner concentration detection sensor, and the toner is developed in the two-component developer in the developing container 409 according to the detection information. It is replenished to the medicine. The toner concentration detection sensor detects the toner concentration of the developer in the developing container 409 based on the measured value of the magnetic permeability of the developer using, for example, the inductance of the coil. The toner hopper 420 is driven and controlled in accordance with the detection of the toner concentration detection sensor, and the toner in the toner hopper 420 is replenished to the two-component developer in the developing container 409, stirred by the stirring member 414, and uniformly mixed with the carrier. Stir.

  The developing device shown in FIGS. 1 to 4 is an example of the developing device of the present invention. The developing device of the present invention includes a developer carrier shape, a developing container shape, the presence / absence of a stirring / conveying member, the arrangement of magnetic poles, The shape of the developer supply member, the presence / absence of a supply container, and the like are not limited to these examples.

  Next, the developer (toner) used in the developing device according to the present invention will be described. The toner used in the present invention is a mixture of a developer binder resin with a colorant, a charge control agent, a release agent, inorganic fine particles, and the like. There are non-magnetic developers that do not contain materials. The format is appropriately selected according to the developing device. Further, the toner used in the present invention has a weight average particle diameter in the range of 4 μm or more and 11 μm or less in any type, so that the triboelectric charge amount or image quality and image density of the toner are balanced. Since it becomes a thing, it is preferable. When the weight average particle diameter of the toner is 11 μm or less, it is possible to suppress a decrease in reproducibility of the minute dot image. On the other hand, when the weight average particle diameter of the toner is 4 μm or more, it is possible to suppress the occurrence of fogging, low density, and the like due to charging failure.

  As the binder resin for toner, for example, vinyl resin, polyester resin, polyurethane resin, epoxy resin, phenol resin and the like can be used, and among these, vinyl resin and polyester resin are preferable. For the purpose of improving the triboelectric charge characteristics, the toner can contain a charge control agent in the toner particles (internal addition), or can be mixed with the toner particles (external addition). The charge control agent facilitates optimal charge amount control according to the development system.

  The following can be used as a positive charge control agent. Modified products with nigrosine, triaminotriphenylmethane dyes and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. These can be used alone or in combination of two or more. As the negative charge control agent, an organometallic compound and a chelate compound are effective. Examples thereof include aluminum acetylacetonate, iron (II) acetylacetonate, and 3,5-ditertiary butyl salicylate. In particular, acetylacetone metal complexes, monoazo metal complexes, naphthoic acid or salicylic acid metal complexes or salts are preferred.

  When the toner is a magnetic toner, the following can be used as the magnetic material. Iron oxide-based metal oxides such as magnetite, maghemite, and ferrite; magnetic metals such as Fe, Co, and Ni; these metals and Al, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Alloys with metals such as Cd, Ca, Mn, Se, Ti, W, V, and mixtures thereof. These magnetic materials can also serve as a colorant. Pigments and dyes can be used as the colorant to be blended with the toner, and these may be appropriately selected and used.

  It is preferable to add a release agent to the toner. Examples of the release agent include the following. Waxes mainly composed of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax and paraffin wax, and fatty acid esters such as carnauba wax, Fischer-Tropsch wax, sazol wax and montan wax. Further, the toner is externally added with inorganic fine particles such as silica, titanium oxide, and alumina in order to improve environmental stability, charging stability, developability, fluidity, storage stability and cleaning properties, that is, a developer. It is preferable to exist in the vicinity of the surface.

  The addition amount of the inorganic fine particles is preferably 0.1% by mass to 5.0% by mass in the toner, and more preferably 0.5% by mass to 4.0% by mass. Further, various external additives may be used in combination. In addition to the above, external additives can be appropriately added to the toner. Examples of applicable external additives include lubricants such as polytetrafluoroethylene, zinc stearate, and polyvinylidene fluoride, and abrasives such as cerium oxide, strontium titanate, and strontium silicate.

  In order to produce the toner, first, a binder resin, a pigment or dye as a colorant, a release agent, and if necessary, a magnetic material, a charge control agent, and other additives are mixed as in a Henschel mixer or a ball mixer. Mix thoroughly by machine. Next, this is melted using a heat kneader such as a heating roll, a kneader, or an extruder, and the release agent, pigment, dye, and magnetic substance are dispersed or dissolved while the resins are mutually compatible. The melt is cooled and solidified, and then pulverized and classified to obtain toner particles. Furthermore, a desired additive may be added as necessary, and mixed well by a mixer such as a Henschel mixer to obtain a developer (toner). When such a developer is used after being subjected to a spheroidizing treatment or a surface smoothing treatment by various methods, it is preferable because transferability is good. Examples of such a method include the following. In a device having a stirring blade or blade and a liner or casing, for example, when the developer is passed through a minute gap between the blade and the liner, the surface is smoothed or the developer is made spherical by mechanical force. A method is mentioned. Further, there are a method of suspending toner in warm water and making it spherical, and a method of making toner spherical by exposing the toner to a hot air stream.

  Further, as a method for directly producing a spherical developer, there is a method in which a mixture containing a monomer as a developer binder resin as a main component is suspended in water and polymerized to obtain a toner. In general, first, a polymerizable monomer, a colorant, a polymerization initiator and, if necessary, a crosslinking agent, magnetic material, charge control agent, release agent, and other additives are uniformly dissolved or dispersed in a single amount. A body composition. Next, the monomer composition is dispersed in appropriate droplets using a suitable stirrer in a continuous phase containing a dispersion stabilizer, such as an aqueous phase, and further subjected to a polymerization reaction to develop a toner having a desired particle size. It is a method of obtaining an agent. In the case of a two-component developer, the carrier preferably has a volume average particle diameter (Dv) of 15.0 μm to 70.0 μm. By controlling within the above range, the shape of the magnetic carrier can be controlled to be substantially spherical and uniform, so that good charge imparting performance can be maintained. More preferably, the volume average particle diameter (Dv) is 20.0 μm to 50.0 μm, which is excellent in terms of high image quality and durability stability.

The true specific gravity of the carrier is preferably 3.0 g / cm ^{3 to} 5.0 g / cm ³ , more preferably 3.2 g / cm ^{3 to} 4.0 g / cm ³ . When the true specific gravity is within this range, the load on the toner is reduced in the stirring and mixing of the carrier and the toner, the toner spent on the carrier is suppressed, and the toner separation can be maintained well for a long period of time. This is preferable because carrier adhesion to the substrate is suppressed. As the magnetic carrier, one having a resin component on at least its surface is used. For example, magnetic metal such as iron, copper, nickel, cobalt, or the like having a resin layer on the core material of magnetic oxide such as magnetite or ferrite, or magnetic fine particle dispersion type in which magnetic fine particles as described above are dispersed in resin A carrier or the like can be used.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in the following mixing | blending are a mass part and the mass%, respectively.
Below, the measuring method of the physical property in connection with this invention is demonstrated.
1. 1. Measuring method of developer carrier 1-1. Primary average particle diameter of conductive ceramic particles Using a focused ion beam (trade name: FB-2000C; manufactured by Hitachi, Ltd.), the cross section of the developer carrier is perpendicular to the axial direction of the developer carrier. And cut every 20 nm. Each cut section was photographed using an electron microscope (trade name: H-7500; manufactured by Hitachi, Ltd.). The particle diameters of 100 ceramic particles were measured by taking the measured value of the image in which the sum of the major axis and the minor axis is the maximum for each particle from a plurality of captured images, with the major axis and minor axis of the particle being the major axis and minor axis, respectively. The particle diameter of the particles was the average value of the measured major axis and minor axis. The arithmetic average particle size was obtained from each particle size and used as the primary average particle size. The measurement magnification was 20,000 times.

1-2. Ratio of major axis / minor axis of conductive ceramic particles For measurement of the major axis and minor axis of the conductive ceramic particles, an enlarged photograph taken at an magnification of 20,000 using an electron microscope was used. About 100 samples randomly sampled from this enlarged photograph, the major axis and minor axis were measured in the same manner as in 1-1, the ratio of major axis / minor axis was determined, and the average value of the major axis / minor axis of the particle was determined. Ratio.
1-3. Electric resistivity of conductive ceramic particles The powder was measured under a pressure of 10 MPa using a powder measurement system MCP-PD41 (manufactured by Dia Instruments Co., Ltd.). The electrical resistivity was measured by a four-point probe method using Lorester GP or Hi-Lester UP (both manufactured by Mitsubishi Chemical Corporation). The measurement environment was 20 ° C. to 25 ° C., 50% RH to 60% RH.
1-4. Volume resistivity of resin layer A resin layer of 7 μm to 20 μm is formed on a PET sheet having a thickness of 100 μm, and a resin is measured using a 4-terminal probe with a resistivity meter “Loresta AP” (trade name, manufactured by Mitsubishi Chemical). The volume resistance value of the layer was measured. The measurement environment was 20 ° C. to 25 ° C., 50% RH to 60% RH.

1-5. Arithmetic mean roughness Ra of developer carrier surface
Based on JIS B0601 (2001), Ra was measured using a surface roughness meter “Surf Coder SE-3500” (trade name, manufactured by Kosaka Laboratory Ltd.). The measurement conditions were a cut-off of 0.8 mm, an evaluation length of 4 mm, a feed rate of 0.5 mm / s, measurement of 3 points in the axial direction × 3 points in the circumferential direction = 9 points, and the average value was Ra.
1-6. A laser diffraction type particle size distribution meter (trade name: Coulter LS-230 type particle size distribution meter; manufactured by Beckman Coulter Co., Ltd.) was used as a volume average particle size measuring device of the unevenness imparting particles. A small amount module was used for the measurement, and isopropyl alcohol (IPA) was used as the measurement solvent. First, the measurement system of the measuring apparatus was washed with IPA for about 5 minutes, and a background function was executed after washing. Next, about 10 mg of a measurement sample was added to 50 ml of IPA. Disperse the sample suspension for about 2 minutes with an ultrasonic disperser to obtain a sample solution, and then gradually add the sample solution into the measurement system of the measurement device. The PIDS on the screen of the device is 45%. The sample concentration in the measurement system was adjusted to be 55% to 55%. Thereafter, measurement was performed, and a volume average particle diameter calculated from the volume distribution was obtained.

1-7. Film thickness of resin layer Laser dimension measuring instrument (manufactured by Keyence Corporation; controller “LS-5500” (trade name) and sensor head “LS-5040T” (trade name)) that measures the outer diameter of the cylinder with laser light Using. A sensor unit was separately fixed to an apparatus equipped with a developer carrier fixing jig and a developer carrier feeding mechanism, and the outer diameter of the developer carrier was measured. The measurement was carried out at 30 locations by dividing the developer carrier in the longitudinal direction into 30 parts, and further rotating the developer carrier 90 ° in the circumferential direction, followed by 30 locations, a total of 60 locations. The average value of the measured values obtained was taken as the outer diameter of the sample. The outer diameter of the substrate was measured before the resin layer was formed, the outer diameter was measured again after the resin layer was formed, and the difference was taken as the film thickness of the resin layer.

2. 2. Measuring method of developer 2-1. Weight average particle diameter D4 of developer (magnetic toner)
The particle size was measured using a particle size measuring apparatus (trade name: Coulter Multisizer III; manufactured by Beckman Coulter, Inc.). As the electrolytic solution, a 1% NaCl aqueous solution prepared using first grade sodium chloride was used. About 0.5 ml of alkylbenzene sulfonate was added as a dispersant to about 100 ml of the electrolyte, and about 5 mg of a measurement sample was further added to suspend the sample. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the volume and number distribution of the measurement sample are measured using the 100 μm aperture with the measuring device to obtain the volume distribution and the number distribution. Calculated. From this result, the weight-based weight average particle diameter (D4) determined from the volume distribution was determined.

2-2. Average circularity of developer The average circularity was measured using a flow particle image measuring device “FPIA-2100” (trade name, manufactured by Sysmex Corporation) in an environment of 23 ° C. and 60% RH. The developer having a circle equivalent diameter of 0.60 μm to 400 μm was measured, and the individual circularity of the particles measured there was determined by the following formula. The average circularity of the sample is a value obtained by dividing the total circularity of particles having an equivalent circle diameter of 3 μm or more and 400 μm or less by the total number of particles.
Circularity = L ₀ / L
[Where L ₀ is the perimeter of a circle having the same projection area as the particle image, and L is the particle projection when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm). The perimeter of the image. ]. In the above apparatus, after calculating the circularity of each particle, in calculating the average circularity, each particle is divided into a class having a circularity of 0.4 to 1.0 divided into 61 classes according to the obtained circularity. The average circularity is calculated using the center value and frequency of the dividing points.

3. 3. Raw material for developer carrier 3-1. Polyethyleneimine 3-1-1. Production of polyethyleneimine a-1 In a reactor equipped with a stirrer, a cooler and a dropping funnel, 100 parts by mass of polyethyleneimine (trade name Epomin SP-012, manufactured by Nippon Shokubai Co., Ltd.) was dispersed in 1600 parts by mass of toluene. Next, 310 parts by mass of n-octyl isocyanate was added and reacted at 80 ° C. for 3 hours, and then cooled to 25 ° C. The obtained reaction mixture solution was mixed with 1600 parts by mass of methanol to precipitate a reaction product, and then filtered and dried to obtain a powdered alkyl isocyanate-modified polyethyleneimine a-1.
3-1-2. Production of polyethyleneimine a-2 to a-7 The types and amounts of ethyleneimine and alkylisocyanate are as shown in Table 1, and the other conditions are the same as those described above, and the alkylisocyanate-modified polyethyleneimine a-2 to a-7 is used. Manufactured.
3-1-3. Polyethyleneimine a-8
Polyethyleneimine (trade name Epomin SP-012, manufactured by Nippon Shokubai Co., Ltd.) was used as polyethyleneimine a-8.

3-2. Ceramic particles The ceramic particles shown in Table 2 were used.

3-3. Resins Other than polyethyleneimine, the following resins were used as the developer carrier.
C-1: Resol type phenol resin solution containing 40% methanol (trade name: J-325; Dainippon Ink Co., Ltd.).
C-2: Silicone resin (trade name: SR2410; manufactured by Toray Dow Corning Silicone Co., Ltd.)
3-4. Conductive agent Toka Black # 5500 (trade name, manufactured by Tokai Carbon Co., Ltd.) was used as the conductive agent.
3-5. Asperity imparting particles Nika beads ICB-0520 (volume average particle size = 6.2 μm: manufactured by Nippon Carbon Co., Ltd .; trade name) was used as the irregularity imparting particles.

4). Production of developer 4-1. Production of Developer d-1 Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 7.0 mol
Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 3.0 mol
Terephthalic acid 3.0mol
Trimellitic anhydride 1.9 mol
Fumaric acid 5.0 mol
Dibutyltin oxide 0.2g
The above material was put into a 4-liter 4-neck flask made of glass, and a thermometer, a stirring rod, a condenser and a nitrogen introduction tube were attached, and placed in a mantle heater.
Styrene 1.9 mol
2-Ethylhexyl acrylate 0.21 mol
Fumaric acid 0.15 mol
α-Methylstyrene dimer 0.03 mol
Dicumyl peroxide 0.05 mol
The said material was put into the dropping funnel as a vinyl polymer raw material. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the vinyl polymer raw material was dropped from the dropping funnel over 4 hours while stirring at a temperature of 145 ° C. Next, the temperature was raised to 200 ° C. and reacted for 4 hours to obtain a hybrid resin.

Hybrid resin 100 parts Magnetic iron oxide (average particle size: 0.18 μm, Hc: 9.6 kA / m, σs: 81 Am ² / kg, σr: 13 Am ² / kg) 75 parts Monoazo iron complex “T-77” ( Trade name, manufactured by Hodogaya Chemical Co., Ltd.) 2 parts Low molecular weight ethylene-propylene copolymer (trade name; Viscol 550-P, manufactured by Sanyo Chemical Co., Ltd.) 5 parts A twin screw extruder in which a mixture of the above materials was heated to 130 ° C After being melt-kneaded with, the melt-kneaded mixture was cooled and solidified. The cooled and solidified mixture is coarsely pulverized with a hammer mill, and the resulting coarsely pulverized product is finely pulverized with a turbo mill (manufactured by Turbo Kogyo Co., Ltd.) and then classified with an air classifier to obtain a magnetic material having a weight average particle diameter of 5.4 μm. A toner was obtained. To 100 parts of this magnetic toner, 1.0 part of hydrophobic silica fine powder (BET 180 m ^{2 /} g) is externally added with a Henschel mixer “FM-75 type” (trade name, manufactured by Mitsui Miike Chemical Co., Ltd.). Thus, developer d-1 having a circularity of 0.935 was obtained.

4-2. Production of developer d-2 Styrene 66 parts Butyl acrylate 12 parts Monobutyl maleate 9 parts Di-tert-butyl peroxide 0.8 part The mixture of the above materials is refluxed (temperature: 145 ° C to 155 ° C). The solution was dropped into 200 parts of cumene over 4 hours to complete solution polymerization under reflux of cumene. Furthermore, cumene was removed while raising the temperature to 200 ° C. under reduced pressure to obtain a styrene-butyl acrylate copolymer.
Styrene 50 parts Butyl acrylate 20 parts Monobutyl malate 2 parts Divinylbenzene 0.4 part Benzoyl peroxide 0.8 part tert-Butylperoxy-2-ethylhexanoate 0.6 part

30 parts of the styrene-butyl acrylate copolymer was dissolved in a mixture of the above materials to obtain a mixed solution. To this mixed solution, 170 parts of water in which 0.15 part of polyvinyl alcohol partially saponified product was dissolved was added to prepare a suspension dispersion with vigorous stirring. Further, 100 parts of water was added, and the above suspension dispersion was added to a reactor substituted with a nitrogen atmosphere, and polymerized at about 80 ° C. for 8 hours. After completion of the polymerization, the mixture was filtered off, sufficiently washed with water, dehydrated and dried to obtain a styrene-butyl acrylate copolymer composition.
Styrene-butyl acrylate copolymer composition 100 parts Magnetic body (average particle size: 0.20 μm) 75 parts Monoazo iron complex “T-77” (trade name, manufactured by Hodogaya Chemical Co., Ltd.) 1.5 parts Low Molecular weight ethylene-propylene copolymer “Biscol 550-P” (trade name, manufactured by Sanyo Chemical Industries) 4 parts

The mixture of the above materials was premixed with a Henschel mixer and then melt-kneaded with a twin-screw extruder heated to 115 ° C. Thereafter, the mixture was cooled and solidified, and coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner. The obtained coarsely pulverized toner was coated with a mechanical pulverizer turbo mill (manufactured by Turbo Kogyo Co., Ltd., coated with chromium alloy plating containing chromium carbide on the rotor and stator surfaces (plating thickness 150 μm, surface hardness HV1050)). Was mechanically pulverized. The finely pulverized product was classified and removed at the same time by a multi-division classifier “Elbow Jet Classifier” (trade name, manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect. Through the above steps, negative triboelectrically chargeable toner particles having a weight average particle diameter (D4) of 5.8 μm and an average circularity of 0.947 were obtained.
100 parts of the toner particles and 1.2 parts of hydrophobic silica fine powder treated with hexamethyldisilazane and then treated with dimethyl silicone oil were mixed with a Henschel mixer to obtain developer d-2.

4-3. Production of developer d-3 4-3-1. Manufacture of cyan toner 450 parts of 0.12 mol / l-Na ₃ PO ₄ aqueous solution was added to 710 parts of ion-exchanged water, heated to 60 ° C., and then a TK homomixer (trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.) Was stirred at 11000 rpm. To this, 70 parts of a 1.2 mol / l-CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .
Styrene 162 parts n-butyl acrylate 38 parts ester wax CH ₃ (CH ₂ ) ₂₀ COO (CH ₂ ) ₂₁ CH ₃ (maximum endothermic peak temperature 72 ° C., Mw 650, Mn 500) 20 parts 3,5-di-tert-butylsalicylic acid Aluminum compound 1 part Saturated polyester (terephthalic acid-propylene oxide modified bisphenol A; acid value 15, Mw 23000, Mn 3500) 10 parts C.I. I. Pigment Blue 15: 3 12 parts The above materials were heated to 60 ° C., and uniformly dissolved and dispersed at 10,000 rpm using a TK homomixer (trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.). In this, 8 parts of polymerization initiators 2,2′-azobis (2,4-dimethylvaleronitrile) were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was put into an aqueous medium and stirred at 11000 rpm for 10 minutes with a TK homomixer at 60 ° C. in a nitrogen atmosphere to granulate the polymerizable monomer composition. Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. and reacted for 10 hours. After completion of the polymerization reaction, the residual monomer is distilled off under reduced pressure, and after cooling, hydrochloric acid is added to dissolve Ca ₃ (PO ₄ ) _{2 and the} like, followed by filtration, washing with water, and drying to obtain a weight average particle size of 7. Cyan particles having a size of 1 μm and an average circularity of 0.984 were obtained.
Titanium oxide particles (number distribution based maximum peak particle size 40 nm, hydrophobicity 65%): 0.5 parts silica particles (number distribution based maximum peak particle size 30 nm, hydrophobicity 95%): 0.8 parts The above materials are added to 100 parts of cyan particles and mixed with a Henschel mixer “FM-75 type” (trade name, manufactured by Mitsui Miike Chemical Co., Ltd.), and the weight average particle size is 6.0 μm and the average circularity is 0.984. Of cyan toner was obtained.

4-3-2. Production of magnetic carrier 4.0% by mass of a silane coupling agent (3- (2-aminoethylaminopropyl) trimethoxysilane) on magnetite powder having a number average particle size of 250 nm and a specific resistance of 5.1 × 10 5 Ω · cm. In addition, the mixture was surface-treated by mixing and stirring at 110 ° C. in a container. Similarly, hematite powder having a number average particle size of 260 nm and a specific resistance of 4.9 × 10 7 Ω · cm was surface-treated. 10 parts of phenol, 6 parts of formaldehyde solution (37% by weight formaldehyde aqueous solution), 76 parts of magnetite treated as described above and 8 parts of hematite treated as described above were placed in a flask and mixed well at 40 ° C. The amount of dissolved oxygen in the reaction medium at this time was 7.3 g / m ³ . Subsequently, nitrogen gas was introduced into the reaction medium at a flow rate of 1.5 × 10 ⁻² m ³ / h, and substitution was performed for 20 minutes. At this time, the amount of dissolved oxygen in the reaction medium was 1.0 g / m ³ . Next, 5 parts of 28% by weight ammonia water and 10 parts of water are added, and then the amount of nitrogen introduced is suppressed to 0.3 × 10 ⁻² m ³ / h and heated from room temperature at an average rate of temperature increase of 3.0 ° C./min. Then, the temperature was raised and maintained while stirring up to 85 ° C., and the reaction was allowed to cure by polymerization for 3 hours. The stirring blade peripheral speed at this time was 1.8 m / s. Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Next, this was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C. to obtain a spherical magnetic carrier core in which a magnetic material was dispersed.

Methanol was volatilized while applying a 3% by mass methanol solution of γ-aminopropyltrimethoxysilane represented by the following chemical formula to the surface of the obtained carrier core while applying shear stress continuously.
NH ₂ —CH ₂ CH ₂ CH ₂ —Si— (OCH ₃ ) ₃
Further, a silicone resin “SE2410” (trade name, manufactured by Toray Dow Corning) was diluted with toluene so that the silicone resin solid content was 20%. While stirring the carrier core treated with the silane coupling agent in the processing machine at 50 ° C., the diluted silicone resin was added under reduced pressure, and 1.0 mass% resin coating was performed on the carrier core. . Thereafter, the toluene was volatilized while stirring in a nitrogen gas atmosphere for 2 hours, and then the heat treatment was performed at 140 ° C. for 2 hours in a nitrogen atmosphere to loosen the aggregates. Then, coarse particles were removed with a sieve having an opening of 76 μm. Thus, a magnetic carrier having a volume average particle size of 34.07 μm and an average circularity of 0.921 was obtained. To 92 parts of the obtained magnetic carrier, 8 parts of cyan toner was added and mixed for 2 minutes by a tumbler mixer to obtain developer d-3.

Example 1
<Manufacture of developer carrier e-1>
Developer carrier e-1 was produced by the following method. First, the following materials were mixed and processed in a horizontal sand mill (filling ratio of zirconia beads having a diameter of 0.6 mm: 85%) to obtain a coating liquid f-1.
Polyethyleneimine a-2 10 parts by weight Resin c-1 400 parts by weight (solid content 240 parts by weight)
Ceramic particles b-1 25 parts by mass Conductive agent (Toker Black # 5500) 100 parts by mass Concavity and convexity imparted particles (Nikabead ICB-0520) 25 parts by mass Toluene 1000 parts by mass An aluminum cylindrical tube having an outer diameter of 20 mm (Ra = 0. 4 μm; reference length (lr) = 4 mm) was prepared. After masking both ends 6 mm of the substrate, the substrate was placed so that its axis was in the vertical direction. And the said base | substrate was rotated at 1200 rpm, the coating liquid f-1 was apply | coated while lowering | hanging an air spray gun at 30 mm / sec, and the coating film was formed so that the thickness after hardening might be set to 12 micrometers. Subsequently, the coating film was cured by heating in a hot air drying oven at 150 ° C. for 30 minutes to obtain a developer carrier e-1.

<Assembly of electrophotographic image forming apparatus and image evaluation using it>
A magnet roller was inserted into the obtained developer carrying member e-1, and flanges were attached to both ends, and the developer was mounted as a developing roller of a developing device of an electrophotographic image forming apparatus (trade name: iR3045; manufactured by Canon Inc.). The gap between the magnetic doctor blade and the developer carrier e-1 was 230 μm. Further, the developer d-1 was introduced into the electrophotographic image forming apparatus, and the following image evaluation was performed. That is, an image output test of 1000 copies of a character image having a printing ratio of 3% by A4 horizontal feeding was performed, and an initial image output test was performed. After that, an image printing test for continuous copying was performed up to 1 million sheets, and an image printing test after endurance was performed. The image evaluation was image density, density unevenness, ghost, and abrasion resistance, and was determined by the following evaluation method and evaluation criteria. The image evaluation was performed in a normal temperature and normal humidity environment (23 ° C., 60% RH; N / N). For image evaluation, A4 office planner paper (trade name, manufactured by Canon Sales; 64 g / m ² ) was used. The results are shown in Table 4.

(1) Image density A solid image was output in the image output test, the density was measured at five points, the average value was taken as the image density, and the relative density with respect to the white background image with a document density of 0.00 was measured. . From the result, the following criteria were evaluated. The image density was “Macbeth reflection densitometer RD918” (manufactured by Macbeth).
A: 1.35 or more.
B: 1.20 or more and less than 1.35.
C: 1.00 or more and less than 1.20.
D: Less than 1.00.

(2) Density Unevenness A halftone and solid black image was output, and linear and belt-like light and shade differences running in the image traveling direction were evaluated according to the following criteria. Image density unevenness due to ghost and blotch factors was excluded and evaluated. The density unevenness was evaluated by ranking based on the following criteria.
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 band in which the density difference can be visually confirmed is confirmed on the halftone image.
D: A density difference that can be clearly measured with a reflection densitometer appears in a strip shape on the halftone image, and the density difference can be visually confirmed even on a solid black image.

(3) Ghost Output image of the printer (image chart in the case of a copier) with a solid black hieroglyph image (square, perfect circle, etc.) equally spaced on a white background corresponding to one round of the developing sleeve at the front of the image The other part was halftone. In the output image, ranking was performed according to how the ghost of the hieroglyph image appeared on the halftone. (Positive ghost indicates a ghost having a higher image density than halftone, and negative ghost indicates a ghost having a lower image density than halftone.) The ghost was ranked and evaluated based on the following criteria.
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.
D: Ghost appears clearly as shading, and density difference can be measured with a reflection densitometer.
(4) Abrasion resistance 1-5. According to the method for measuring the arithmetic average roughness Ra on the surface of the developer carrier, the surface roughness of the developer carrier before and after the image-copying test for 1 million sheets of continuous copying is measured, and the difference between them is defined as the change in surface roughness ΔRa. The wear resistance was evaluated.

(Examples 2 to 13 and Comparative Examples 1 to 4)
Developer carriers e-2 to e-13 and e-26 to e-29 were produced in the same manner as in Example 1 except that the coating solutions shown in Table 3 were used. An agent carrier was incorporated to obtain an improved developing device. Using this, image evaluation was performed in the same manner as in Example 1. The results are shown in Table 4.

(Example 14)
<Manufacture of developer carrier e-14>
Developer carrier e-14 was produced by the following method. First, the following materials were mixed and processed with a horizontal sand mill (filling ratio of zirconia beads having a diameter of 0.6 mm: 85%) to obtain a coating liquid f-14.
Polyethyleneimine a-2 200 parts by weight Ceramic particles b-6 20 parts by weight Conductive agent (Toker Black # 5500) 100 parts by weight Concavity and convexity imparted particles (Nikabead ICB-0520) 30 parts by weight Toluene 900 parts by weight Aluminum having an outer diameter of 20 mm as a substrate A cylindrical tube (Ra = 0.4 μm; reference length (lr) = 4 mm) was prepared. After masking 6 mm at both ends of the substrate, the substrate was placed so that its axis was parallel to the vertical. And the said base | substrate was rotated at 1500 rpm, the coating liquid f-14 was apply | coated while lowering | hanging an air spray gun at 40 mm / sec, and the coating film was formed so that the thickness after hardening might be set to 8 micrometers. Then, it heated for 30 minutes in a 150 degreeC hot-air drying furnace, the coating film was hardened, and the developing agent carrier e-14 was obtained.

<Assembly of electrophotographic image forming apparatus and image evaluation using it>
A magnet roller was assembled to the obtained developer carrying member e-14, and this was assembled into a genuine cartridge of a printer (trade name: LASER JET4350; manufactured by Hewlett Packard) to obtain a developing device. This was mounted on the printer, and the next image evaluation was performed using developer d-2. That is, an image output test of 500 copies of a character image having a printing ratio of 3% by A4 vertical feeding was performed, and an initial image output test was performed. After that, an image printing test for continuous copying was performed up to 50,000 sheets, and an image printing test after endurance was performed. The image evaluation was image density, density unevenness, and ghost, and was determined by the following evaluation method and the same evaluation criteria as in Example 1. The image evaluation was performed in a normal temperature and normal humidity environment (23 ° C., 60% RH; N / N). For image evaluation, letter-sized Business 4200 paper (trade name, manufactured by XEROX; 75 g / m ² ) was used. The results are shown in Table 6.

(Examples 15 to 17 and Comparative Examples 5 to 8)
Developer carriers e-15 to e-17 and e-30 to e-33 were produced in the same manner as in Example 14 except that the coating solutions shown in Table 4 were used. An agent carrier was incorporated to obtain an improved developing device. Using this, image evaluation was performed in the same manner as in Example 14. The results are shown in Table 6.

(Example 18)
<Manufacture of developer carrier e-18>
Developer carrier e-18 was produced by the following method. First, the following materials were mixed and treated with a horizontal sand mill (filling ratio of zirconia beads having a diameter of 0.6 mm: 85%) to obtain a coating liquid f-18.
Polyethyleneimine a-2 10 parts by weight Resin c-1 290 parts by weight Ceramic particles b-1 30 parts by weight Conductive agent (Toker Black # 5500) 100 parts by weight Concavity and convexity imparting particles (Nikabead ICB-0520) 50 parts by weight Toluene 1500 parts by weight An aluminum cylindrical tube (Ra = 0.5 μm; reference length (lr) = 4 mm) having an outer diameter of 20 mm was prepared as a substrate. After masking 6 mm at both ends of the substrate, the substrate was placed so that its axis was parallel to the vertical. And the said base | substrate was rotated at 1000 rpm, the coating liquid f-18 was apply | coated, moving down an air spray gun at 20 mm / sec, and the coating film was formed so that the thickness after hardening might be set to 15 micrometers. Then, it heated for 30 minutes in a 150 degreeC hot-air drying furnace, the coating film was hardened, and the developing agent carrier e-18 was obtained.

<Assembly of electrophotographic image forming apparatus and image evaluation using it>
A magnetic roller is incorporated into the obtained developer carrying member e-18, flanges are attached to both ends, this is replaced with a cyan developer, developer d-3 is filled, and a digital multifunction machine (trade name: iRC6800) ; Canon Inc.). Further, the gap (SD distance) between the developer carrying member and the photosensitive drum was changed to 380 μm. As development conditions, the dark part potential (Vd) of the image area of the photosensitive drum was set to 400V, and the bright part potential (Vl) of the non-image area was set to 120V. A 250 V DC bias and a Vpp (voltage between peaks) 1.8 kV, AC bias consisting of a rectangular wave with a frequency of 2.7 kHz were applied as superimposed on the developer carrying member. Using the evaluation machine under the above conditions, an image output test was performed for 1000 copies of a character image with a printing ratio of 3% at A4 horizontal feed, and an initial image output test was performed. After that, a continuous copying image printing test was performed up to 100,000 sheets, and a post-durability image printing test was performed. The image evaluation was image density, density unevenness, and ghost, and was determined by the same evaluation method and evaluation standard as in Example 1. The results are shown in Table 8.

(Examples 19 to 25 and Comparative Examples 9 to 12)
Developer carriers e-19 to e-25 and e-34 to e-37 were produced in the same manner as in Example 18 except that the coating solutions shown in Table 7 were used. An agent carrier was incorporated to obtain an improved developing device. Using this, image evaluation was performed in the same manner as in Example 18. The results are shown in Table 8.

101, 201, 301, 401: Resin layer 102, 202, 302, 402: Substrate 103, 203, 303, 403: Development sleeve 104, 204, 404: Magnet roller 105, 205, 405: Developer carrier 106, 206 , 306, 406: Photosensitive drum (electrostatic latent image carrier)
107: Magnetic blade (developer layer regulating member)
215, 315: Elastic blade (developer layer regulating member)
317: Non-magnetic one-component developer 421: Magnetic particles 422: Magnet roller

Claims (6)

  A developer carrier comprising a substrate and a resin layer, wherein the resin layer contains at least polyethyleneimine and conductive ceramic particles. The developer carrier according to claim 1, wherein the polyethyleneimine is an alkyl isocyanate-modified polyethyleneimine having at least units represented by the general formulas (1) and (2).

  The resin layer contains a phenol resin, and the content of the polyethyleneimine is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the phenol resin. The developer carrier described in 1.   4. The developer carrying member according to claim 1, wherein a primary average particle size of the conductive ceramic particles is 0.3 μm or more and 3.0 μm or less.   The developer carrying member according to claim 1, wherein the conductive ceramic particles are boron carbide or silicon carbide.   A negatively charged developer having toner particles, a container containing the developer, a developer carrier for carrying and transporting the developer stored in the container, and a developer on the developer carrier A developing device having a developer layer thickness regulating member for forming a layer, wherein the developer carrying member is the developer carrying member according to any one of claims 1 to 5. A developing device.

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