JP2007025599A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of stably giving a high-quality image. <P>SOLUTION: In the developing device, a one-component developer is carried on a rotating developer carrier and transported, the layer thickness of the carried developer is regulated by an elastic developer regulating member which comes into contact with the developer carrier by way of the developer, the developer of which the layer thickness has been regulated is transported to a development region opposite to an image carrier, and an electrostatic latent image carried on the image carrier is visualized by development with the transported developer. The developer carrier comprises at least a substrate and a conductive resin coating layer on a surface of the substrate, and the conductive resin coating layer has a surface shape with a ten-point average roughness Rzjis of the surface of 2.0-5.5 μm, a variation coefficient of the Rzjis of ≤11% and an initial wear height Rpk of ≤0.80 μm. The developer regulating member has a contact pressure (linear pressure) of 5-22 N/m to the developer carrier. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developing device for developing and developing a latent image formed on an image carrier such as an electrophotographic photosensitive member or an electrostatic recording derivative.

  Conventionally, a number of methods are known as electrophotographic methods. Generally, a photoconductive substance is used to form an electrical latent image on an image carrier (photosensitive drum) by various means, and then The electrical latent image is developed with a developer (toner) to become a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat and pressure. To obtain a copy.

  Development methods in electrophotography are mainly divided into a one-component development method and a two-component development method. In recent years, since it is necessary to reduce the size of a copying apparatus for the purpose of reducing the weight and size of an electrophotographic apparatus, a developing apparatus using a one-component developing system is often used.

  The one-component development method does not require carrier particles such as glass beads or iron powder unlike the two-component development method, and therefore the development device itself can be reduced in size and weight. On the other hand, 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 it does not require such an apparatus and can be made small and light.

  In recent years, an electrophotographic apparatus such as a printer apparatus has become higher in the technical direction. For example, what is conventionally 300 or 600 dpi has become 1200 or 2400 dpi. Accordingly, the development method is also required to have higher definition. In addition, copiers are also becoming more sophisticated, and therefore are moving toward digitalization. In this direction, the method of forming an electrostatic image with a laser is the main method, so it is also proceeding in the direction of high resolution, and here again, a high-resolution and high-definition development method is required as in the printer device. Yes.

  Furthermore, colorization is progressing rapidly in the field of electrophotography. Since a color image is formed by appropriately overlapping and developing four color toners of yellow, magenta, cyan, and black, each color toner is required to have higher development characteristics than those of a single color. For this reason, in the one-component development system, it is important to uniformly control the chargeability of the nonmagnetic color toner.

  In general, as a developing device using a one-component developing system, an electrostatic latent image is formed on the surface of a photosensitive drum as an image carrier, friction between the developer carrier (developing sleeve) and toner, and / or on the developing sleeve. The toner is positively or negatively charged by friction with the developer regulating member (developing blade) for regulating the toner coating amount, and the toner is applied thinly on the developing sleeve, and the photosensitive drum and the developing sleeve face each other. There is known a technique in which an electrostatic latent image is visualized as a toner image by being conveyed to the developed area and developing the toner by flying and adhering to the electrostatic latent image on the surface of the photosensitive drum.

  However, when non-magnetic toner is used in such a one-component development system, it is difficult to adjust the charging of the toner, and various devices have been devised. However, problems relating to toner charging non-uniformity and charging durability stability have not been completely solved.

  In particular, while the developing sleeve is repeatedly rotated, the charge amount of the toner coated on the developing sleeve becomes too high due to contact with the developing sleeve, and the toner is attracted by the reflection force on the developing sleeve surface and developed. A so-called charge-up phenomenon is likely to occur in which the sleeve surface does not move and does not move from the developing sleeve to the latent image on the photosensitive drum. When such a charge-up phenomenon occurs, the toner in the upper layer is difficult to be charged and the development amount of the toner is reduced, which causes problems such as thin line images and thin image density of solid images. In addition, a toner that is not properly charged due to charge-up becomes poorly regulated and flows out onto the sleeve, resulting in a phenomenon of streaky, spotted, and wavy irregularities.

  In recent years, in order to digitize electrophotographic devices and achieve higher image quality, toner particles have been made smaller and finer, and waste toner has been reduced for the purpose of further reducing the weight and size of the devices. Therefore, the toner transfer efficiency is improved by making the shape of the toner close to a spherical shape.

  In addition, for the purpose of increasing gloss to give gloss to color images, shortening the first copy time, and saving power, the toner can be fixed by increasing the proportion of low softening point substances in the toner. It tends to lower the temperature.

  As described above, a polymerization method is suitable as a method for producing a toner that achieves a reduction in particle size, fine particle formation, spheroidization, and improvement in fixability.

  The polymerization method used for the toner production is a monomer composition in which a polymerizable monomer, a colorant, a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed. Then, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, such as an aqueous phase, using an appropriate stirrer, and simultaneously subjected to a polymerization reaction to have a desired particle size. This is a method for obtaining toner. Since this manufacturing method does not go through a pulverization step, it is not necessary to impart brittleness to the developer, and further, a material that can use a large amount of a low softening point material that could not be used in the conventional pulverization method. The selection range is widened and preferable. Further, the polymerization method has a characteristic that the particle size distribution of the toner can be sharpened relatively easily and the particle size can be reduced relatively easily, and a substantially spherical toner can be produced.

  However, when the toner obtained by the polymerization method having the above characteristics is used, the shape is spherical, so that the fluidity is too good to coat the toner on the developing sleeve in a uniform thin layer. Tend to be. Therefore, in order to uniformly coat the toner obtained by the polymerization method on the developing sleeve, it is necessary to increase the contact pressure of the developing blade. In particular, the amount of charge per unit mass increases under low temperature and low humidity. The toner easily adheres electrostatically onto the developing sleeve, and the toner is charged up, which tends to cause density reduction and density unevenness. Further, the toner tends to adhere to the surface of the developing blade, and the vertical streak image defect may occur by fusing in a streak shape.

  Also, under high temperature and high humidity, the toner easily changes its quality because it uses a material that easily fluidizes with physical force and heat, and the toner repeatedly rubs between the developing sleeve and the developing blade as copying is repeated. As a result of being subjected to stress, external additives for improving the fluidity of the toner are easily embedded in the toner surface, and it may be difficult to obtain stable developability and transferability due to toner deterioration. is there. Further, when the toner is deteriorated as described above, toner fusion to the surface of the developing sleeve and the surface of the developing blade is promoted, and image defects such as fogging, uneven image density, and vertical stripes tend to be remarkably deteriorated.

  For such toner charge-up and toner deterioration, measures have been taken to improve toner external additives. However, good durability is stable when used in different environments. It has not yet been maintained.

On the other hand, as a method for solving such a phenomenon with a developer carrier, a conductive resin coating layer in which conductive fine powders such as crystalline graphite and carbon, and conductive spherical particles are dispersed in a resin is provided on a metal substrate. A method of using the developing sleeve provided in the developing device in the developing device is disclosed in Patent Document 1. It is recognized that the above-described charge-up phenomenon is greatly reduced by using this method.

  However, in the above developing device, since the uneven shape on the surface of the conductive resin coating layer formed on the surface of the developing sleeve is not sufficiently uniform, the charging characteristics for imparting uniform and rapid charging to the toner are insufficient. . Also, in long-term durable use, particularly when using a spheroidized toner such as a polymerized toner, toner fusing and blade scratches are likely to occur from around the convex portion of the surface irregular shape, In some cases, the fogging is deteriorated due to non-uniform frictional charging of the toner, or vertical stripe-like image defects are generated. Furthermore, there is room for improvement because the toner is insufficiently deteriorated on the developing sleeve due to durability.

  In Patent Document 2, Patent Document 3, and the like, a developing sleeve in which a conductive resin coating layer containing a quaternary ammonium salt compound that is positively charged with respect to iron powder in a resin is provided on a metal substrate. There has been proposed a developing device that prevents excessive charging such as charge-up for a spheroidized toner or a negative toner manufactured by a polymerization method.

  By using this developing device, the effect of improving the prevention of charge-up phenomenon, the uniformity of triboelectric charging and the toner fusion on the developing sleeve is recognized, but the uneven shape on the surface of the developer carrier is still sufficient. Because it is not uniform, especially in high-temperature and high-humidity environments, it is a level sufficient for fusing to the developing sleeve and toner deterioration due to durability, especially for toners that exhibit high gloss fixability and are susceptible to thermal alteration. It has not reached.

Further, in order to improve toner fusion on the surface of the developer carrier, Patent Document 4 discloses a developing device that defines the value of the average inclination Δa of the developer carrier surface, and in Patent Document 5, Rz on the surface of the developer carrier.
Development devices that specify the value of the / Ra ratio have been proposed. However, even with these development devices, particularly in a high-temperature and high-humidity environment, the toner tends to be thermally denatured and exhibits high gloss fixability. Has not reached a sufficient level for fusing to the developing sleeve and toner deterioration due to durability.

  On the other hand, as means for reducing toner deterioration and toner fusion, it is effective to reduce the contact pressure between the developing sleeve and the developing blade. However, this means that the regulating force on the toner is weakened, so that the coating state of the spheroidized toner is particularly uneven and tends to increase, making it difficult to adjust the amount in an appropriate amount and uniform, and uniform and rapid friction on the toner. Charge imparting property is easily damaged.

It is also effective to reduce the surface roughness of the conductive resin coating layer formed on the developing sleeve as a means for controlling the toner coating amount. However, the combination of reducing the contact pressure of the developing blade and reducing the surface roughness of the conductive resin coating layer formed on the developing sleeve is not sufficient to make the surface of the conductive resin coating layer uniform. Therefore, there is still room for improvement with respect to uniform and rapid frictional charging of the toner. Furthermore, if the surface roughness of the conductive resin coating layer formed on the developing sleeve is reduced, it becomes difficult to coat the toner stably and uniformly on the developing sleeve, and vertical streaks are generated in the toner coating due to durability. There is a problem that becomes easy to do.
JP-A-8-240981 JP 2003-057951 A JP 2002-311636 A JP 2000-89572 A JP 2002-296898 A

The present invention has been made in view of the above-described problems, and the developer can be fused to the surface of the developer carrying member or the surface of the developer regulating member so that the developer does not deteriorate or charge up even during continuous copying over a long period of time. By maintaining the uniform coating state of the developer by preventing adhesion, and constantly and rapidly triboelectrically charging the developer, the image density is lowered and the density unevenness, sleeve under the usage conditions that require durability It is an object of the present invention to provide a developing device capable of obtaining a high-quality image free from ghost, fog, and vertical stripes.
In addition, the present invention does not cause problems such as image density reduction, image density unevenness, vertical stripes, and fog even under different environmental conditions, and development that can stably obtain a high-quality image with high image density. It is an object to provide an apparatus.
In addition, the present invention appears when an image is formed using a developer having a small particle diameter, a developer having a high degree of spheroidization, and a developer having improved fixing performance such as high glossiness and low-temperature fixability. Easy developer deterioration and charge-up are prevented, and the developer adhesion to the surface of the developer carrier or developer regulating member is reduced, thereby maintaining a uniform coating state of the developer. It is an object of the present invention to provide a developing device capable of obtaining a high-quality image free from image density reduction, density unevenness, sleeve ghost, fogging, and vertical stripes by constantly and quickly frictionally charging.

The developing device of the present invention that achieves the above object carries a single-component developer carried on a rotating developer carrying member, and has a development having elasticity in contact with the developer carrying member via the developer. After regulating the layer thickness of the carried developer by the agent regulating member, the developer having the regulated layer thickness is transported to the development area facing the image bearing member, and the image bearing is carried by the transported developer. In a developing device for developing and visualizing an electrostatic latent image carried on a body,
The developer carrying member has at least a substrate and a conductive resin coating layer on the substrate surface, and the conductive resin coating layer has a 10-point average roughness Rzjis of 2.0 μm to 5.5 μm. , Rzjis has a coefficient of variation of 11% or less and an initial wear height Rpk of 0.80 μm or less,
The developer regulating member has a contact pressure (linear pressure) with respect to the developer carrying member of 5 N / m to 22 N / m.

  According to the present invention, the developer carrying member has at least a substrate and a conductive resin coating layer on the substrate surface, and the conductive resin coating layer has a 10-point average roughness Rzjis of 2.0 μm to 5 μm. 0.5 μm, the coefficient of variation of Rzjis is 11% or less, the initial wear height Rpk is 0.80 μm or less, and the developer regulating member has a contact pressure against the developer carrying member ( (Linear pressure) of 5 N / m to 22 N / m makes it difficult for the developer to deteriorate even during continuous copying over a long period of time. The developer is uniformly and stably coated on the developer carrier. The surface of the developer carrier, even under different environmental conditions, can prevent the developer from fusing to the surface of the developer carrier or the surface of the developer regulating member and can uniformly and quickly frictionally charge the developer. Developer at Provided is a developing device capable of stably obtaining a high-quality image having a high image density without causing problems such as uniform and rapid frictional charge imparting property, no image density reduction, image density unevenness, vertical stripes, and fogging. can do.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

  First, the developing device of the present invention will be described.

  FIG. 1 is a schematic diagram showing an example of the configuration of the developing device of the present invention when a nonmagnetic one-component developer (sometimes referred to as a developer) is used. In FIG. 1, a photosensitive drum 1 as an image carrier that carries an electrostatic latent image formed by a known process is rotated in the arrow B direction. A developing sleeve 8 as a developer carrying member is composed of a metal cylindrical tube (base) 6 and a conductive resin coating layer 7 formed on the surface thereof. A columnar member can be used instead of the metal cylindrical tube.

  In the hopper 3 which is a developer container, a stirring blade 10 for stirring the developer (nonmagnetic one-component developer) 4 is provided.

  The developer supply / peeling roller 11 which is a developer supply / peeling member for supplying the developer 4 to the developing sleeve 8 and stripping off the developer 4 existing on the surface of the developed sleeve 8 after development is developed. It is in contact with the sleeve 8. When the developer supply / peeling roller 11 rotates in the same direction as the developing sleeve 8, the surface of the developer supplying / peeling roller 11 moves in the counter direction with the surface of the developing sleeve 8. As a result, the non-magnetic one-component developer supplied from the hopper 3 is supplied to the developing sleeve 8. When the developing sleeve 8 carries the developer 4 and rotates in the direction of arrow A, the developer 4 is conveyed to the developing area D that is the area facing the developing sleeve 8 on the surface of the photosensitive drum 1. The developer carried on the developing sleeve 8 has a developer layer thickness defined by the developer regulating member 2 that is in pressure contact with the surface of the developing sleeve 8 via the developer layer. The developer 4 obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 1 by friction with the developing sleeve 8.

  The thickness of the thin layer of the developer 4 formed on the developing sleeve 8 is preferably thinner than the minimum gap in the developing region D between the developing sleeve 8 and the photosensitive drum 1 in the developing portion. The present invention is particularly effective for a non-contact type developing apparatus that develops an electrostatic latent image with such a developer layer.

  A developing bias voltage is applied to the developing sleeve 8 by a developing bias power source 9 in order to cause the nonmagnetic one-component developer 4 carried on the developing sleeve 8 to fly. When a DC voltage is used as the developing bias voltage, the voltage of the value between the potential of the image portion of the electrostatic latent image (the region visualized by the developer 4 attached) and the potential of the background portion is the developing sleeve. 8 is preferably applied. In order to increase the density of the developed image or improve the gradation, it is more preferable to apply an alternating bias voltage to the developing sleeve 8 to form an oscillating electric field whose direction is alternately reversed in the developing portion. In this case, it is preferable that an alternating bias voltage on which a DC voltage component having a value between the image portion potential and the background portion potential is superimposed is applied to the developing sleeve 8.

  The SD distance, which is the minimum gap between the developing sleeve 8 and the photosensitive drum 1 in the developing portion, is preferably 150 μm to 450 μm, and more preferably 200 μm to 400 μm. If the distance between SDs is less than 150 μm, white-out images due to developing bias leaks are likely to occur. On the other hand, when the distance between SD exceeds 450 μm, the reciprocating motion of the developer due to the developing bias increases, so that the swept image or the developer may be easily scattered.

  In so-called regular development in which a developer is attached to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion for visualization, a developer that is frictionally charged to a polarity opposite to that of the electrostatic latent image is used. . In the so-called reversal development in which the developer is attached to the low potential portion of the electrostatic latent image for visualization, a developer that is frictionally charged to the same polarity as the polarity of the electrostatic latent image is used as the developer. Note that the high potential and the low potential are expressed by absolute values. In any case, the developer 4 frictionally charges the polarity for developing the electrostatic latent image by friction with the developing sleeve 8.

  The developer supplying / peeling member 11 is preferably an elastic roller member having an elastic layer formed of resin, rubber, sponge or the like. As the developer supply / peeling member 11, a belt member or a brush member may be used instead of the elastic roller. The developer that has not been transferred to the photosensitive member 1 is once peeled off from the surface of the developing sleeve 8 by the developer supply / peeling member 11, thereby preventing the generation of a stationary developer on the developing sleeve 8. The triboelectric charge is made uniform.

  When the developer supply / peeling roller 11 made of an elastic roller is used as the developer supply / peeling member 11, the circumferential speed of the developer supply / peeling roller 11 is such that the surface of the roller 13 is in relation to the developing sleeve 8. When rotating in the counter direction, it is preferably 20% to 120%, more preferably 30% to 100% with respect to the peripheral speed of 100% of the developing sleeve 8.

  When the peripheral speed of the developer supply / peeling roller 11 is 20% or more, the supply of the developer is sufficient, the followability of the solid image is improved, and the cause of the ghost image can be removed. If the peripheral speed is 120% or less, the developer supply amount is appropriate, the developer layer thickness can be regulated properly, the triboelectric charge amount is also appropriate, the cause of fogging is removed, and the developer is further damaged. Therefore, fogging due to deterioration of the developer and fusion of the developer can be prevented.

  When the rotation direction on the surface of the developer supply / peeling roller 11 is the same (forward) direction as the rotation direction of the surface of the development sleeve 8, the peripheral speed of the developer supply / peeling roller 11 is The developer supply amount is preferably 100% to 300%, more preferably 101% to 200% with respect to the peripheral speed.

  The rotation direction on the surface of the developer supply / peeling roller 11 is more preferably rotated in the direction of rotation on the surface of the developing sleeve 8 and the counter direction from the viewpoint of stripping property and supply property.

  The intrusion amount of the developer supply / peeling member 11 with respect to the developing sleeve 8 is preferably 0.5 mm to 2.5 mm from the viewpoint of developer supply and strippability. When the amount of penetration of the developer supply / peeling member 11 is 0.5 mm or more, the stripping becomes sufficient and ghosting can be prevented. Further, when the intrusion amount is 2.5 mm or less, the developer can be prevented from being damaged, and the developer can be prevented from being fused or fogged due to the deterioration of the developer.

  Next, the developer regulating member used in the developing device of the present invention will be described.

  In the developing device of FIG. 1, as the developer regulating member 11 for regulating the layer thickness of the developer 4 on the developing sleeve 8, a material having rubber elasticity such as urethane rubber or silicone rubber, or a metal such as phosphor bronze or stainless copper. An elastic regulating blade 2 manufactured using an elastic material is used. By pressing the elastic regulating blade 2 against the developing sleeve 8 in a posture opposite to the rotation direction of the developing sleeve 8, a thinner developer layer can be formed on the developing sleeve 8.

  In the present invention, the contact pressure (linear pressure) of the elastic regulating blade 2 with respect to the developing sleeve 8 is 5 N / m to 22 N / m, so that the surface of the developing sleeve 8 is not deteriorated without causing deterioration of the developer. Necessary for reducing the fusion of the developer to the surface of the elastic regulation blade 2, stabilizing the regulation of the developer, and suitably adjusting the developer layer thickness.

  A preferable range of the contact pressure (linear pressure) of the elastic regulating blade 2 with respect to the developing sleeve 8 is (8) N / m to (18) N / m.

  In the developing device of the present invention, the uneven shape of the surface of the conductive resin coating layer 7 on the developing sleeve 8 is less rough than the surface of the conventional developer carrying member, and there are no protruding protrusions. Therefore, the developer regulation can be stabilized even when the contact pressure (linear pressure) from the elastic regulating blade 2 is considerably reduced as described above. The developer layer thickness can be suitably adjusted. When the contact pressure (linear pressure) of the elastic regulation blade 2 with respect to the developing sleeve 8 is less than 5 N / m, the regulation of the developer becomes weak, causing density unevenness, fogging, and developer leakage. When the (linear pressure) exceeds 22 N / m, damage to the developer increases, which tends to cause deterioration of the developer and fusion to the developing sleeve and the elastic regulation blade 2.

  The elastic regulating blade 2 used in the present invention preferably has a ten-point average roughness Rzjis of 1.0 μm or less on the surface of the contact portion with the developing sleeve 8. When the 10-point average roughness Rzjis on the surface of the contact portion with the developing sleeve 8 is set to 1.0 μm or less, the coating state of the developer on the surface of the developing sleeve 8 can be easily controlled to a uniform thickness, and the developer transport amount is adjusted. This is preferable because the effect of triboelectrically charging the developer is improved. When Rzjis exceeds 1.0 μm, the amount of developer transported on the developer carrier becomes too small, and the coating state of the developer becomes uneven, causing streaky density unevenness and thin image density. May end up.

  The elastic regulating blade 2 used in the present invention has a free end on the upstream side in the moving direction of the developing sleeve 8 in order to coat the developer on the developing sleeve 8 in an appropriate amount and uniformly, and the elastic regulating blade 2 and the developing sleeve. 8, the distance NE between the most upstream contact position and the free end is preferably in the range of 0.3 mm to 1.5 mm, and more preferably in the range of 0.7 mm to 1.3 mm.

  When NE is 0.3 mm or more, the amount of developer taken in increases, and the amount of developer conveyed on the developing sleeve 8 increases, so that a sufficient image density can be obtained. Further, when NE is 1.5 mm or less, the amount of developer taken in becomes appropriate, it becomes easy to adjust the amount of developer on the developing sleeve 8 to an appropriate amount, and uniform triboelectric charge can be imparted to the developer. It becomes easy.

  The elastic regulating blade 2 preferably has a polyamide elastomer-containing rubber layer at a contact portion with the developing sleeve 8. In particular, a polyamide elastomer (PAE) -containing rubber layer is attached to the phosphor bronze plate surface that provides stable contact pressure for stable regulation and stable (negative) chargeability to the developer. It is preferable to use one.

  By adopting such a configuration, it becomes easy to control the coating state of the developer on the surface of the developing sleeve 8 to a more uniform thickness even under different environments, and uniform and quick friction charging performance to the developer can be achieved. More improved.

  The polyamide elastomer (PAE) is preferably a copolymer of polyamide and polyether. The polyamide / polyether copolymer exhibits a stable (negative) charge imparting property to the developer due to the polyamide component and exhibits elasticity due to the polyether component, so that the contact pressure of the elastic regulating blade 2 to the developing sleeve 8 is increased. Even if the (linear pressure) is small, the spherical developer can be stably and uniformly coated on the developing sleeve 8, and the developer can be easily triboelectrically charged.

  The polyamide component in the polyamide elastomer structure is preferably 20% by mass or more from the viewpoint of sufficiently and uniformly triboelectrically charging the developer, and from the point of facilitating uniform coating of the developer on the developing sleeve 8. In addition, it is possible to realize good elasticity of the polyamide elastomer, to further prevent the developer from being charged up, to make the coating of the developer on the developing sleeve 8 uniform, and to prevent deterioration of the developer. The polyamide component is preferably 80% by mass or less.

  Next, the developer carrier 8 used in the one-component developing device of the present invention will be described. The developer carrier 8 used in the present invention has at least a base 6 and a conductive resin coating layer 7 on the surface of the base 6. The conductive resin coating layer 7 has a surface ten-point average roughness Rzjis of 2.0 μm to 5.5 μm, a coefficient of variation of Rzjis of 11% or less, and an initial wear height Rpk of 0.80 μm or less. It is characterized by having a surface shape.

  As a result of intensive studies on the above-mentioned problems, the present inventors have found that a low contact pressure is applied to the developer carrier 8 on which the conductive resin coating layer 7 having the above-described uniform uneven shape is formed. When the developer on the developer carrier 8 is triboelectrically charged by the developer regulating member 2 brought into contact with (linear pressure), it is difficult for the developer to deteriorate even during continuous copying over a long period of time. Coating uniformly and stably on the developer carrier, preventing the developer from fusing to the surface of the developer carrier and the surface of the developer regulating member, and facilitating constant and rapid tribocharging of the developer at all times. Was found. Furthermore, it has been found that the configuration of the developing device as described above has an effect that the uniform and rapid frictional charge imparting property of the developer on the surface of the developer carrying member 8 is hardly changed even under different environmental conditions. It was.

  Conventionally, the arithmetic average roughness Ra has generally been used as an indicator of the surface roughness of the developer carrying member as a parameter correlated with the developer transportability. However, when the developer is regulated by a developer regulating member that is brought into contact with the developer carrying member at a low contact pressure (linear pressure) to be frictionally charged, the surface of the developer carrying member is relatively large. The present inventors have found that the value of the above and the uniformity thereof and the ratio of the protruding high convex portion tend to largely depend on the coating state of the developer, and therefore the surface roughness of the developer carrier used in the present invention. As indices, ten-point average roughness Rzjis and Rzjis coefficient of variation and initial wear height Rpk were used.

  The developer carrying member 8 used in the present invention has a surface roughness of the conductive resin coating layer 7 on the surface of which the ten-point average roughness Rzjis specified by JIS B 0601-2001 is 2.0 μm to 5.5 μm. It is in the range. A more preferable range of Rzjis is 2.5 μm to 5.0 μm.

  When the surface roughness Rzjis of the conductive resin coating layer 7 is less than 2.0 μm, the amount of developer transported on the developer carrying member is too small to obtain a sufficient image density, and on the developer carrying member. The coating state of the developer is likely to be uneven, and the developer is likely to be fused in a streak form on the surface of the developer carrying member or the surface of the developer regulating member. On the other hand, when the surface roughness Rzjis of the conductive resin coating layer 7 exceeds 5.5 μm, the level difference of the irregularities on the surface of the conductive resin coating layer 7 formed on the developer carrying member becomes too large, and the developer carrying When the developer is regulated by the developer regulating member 2 that is brought into contact with the body 8 with a low contact pressure (linear pressure) to be frictionally charged, the developer is less likely to be uniformly frictionally charged. Problems are likely to occur.

  The developer carrier 8 used in the present invention is characterized in that the coefficient of variation of Rzjis on the surface of the conductive resin coating layer 7 formed on the surface thereof is 11.0% or less. A more preferable range of the coefficient of variation of Rzjis is 10.5% or less. When the coefficient of variation is larger than 11%, the developer is uniformly developed when the developer is frictionally charged by the developer regulating member 2 that is in contact with the developer carrier 8 with a low contact pressure (linear pressure). The agent is difficult to be charged, and the problem of fog and density unevenness is likely to occur.

The developer carrier 8 used in the present invention is characterized in that the initial wear height Rpk of the conductive resin coating layer formed on the surface thereof is 0.80 μm or less. A more preferable range of Rpk is 0.60 μm or less.
When Rpk is 0.80 μm or less, there is almost no protruding portion that locally protrudes on the surface of the conductive resin coating layer 7 on the developer carrier 8, so that the surface of the developer regulating member 2 is hard to be damaged and further protruded. Since the developer does not adhere to the conductive resin coating layer 7 based on the raised protrusions, a uniform developer coating state can be stably maintained, so that the developer on the developer carrier 8 can be kept in a constant state. It becomes possible to apply frictional charging uniformly and rapidly. On the other hand, when Rpk exceeds 0.80 μm, a large number of protruding protrusions are formed, and the developer is likely to be fused from this point, making it difficult for the developer to be triboelectrically charged, causing fogging, uneven density, and development. Agent charge up occurs. Further, the surface of the developer regulating member 2 is damaged by the protruding convex portion, and the problem of vertical stripes also occurs.

  The initial wear height Rpk is a characteristic value obtained from the surface roughness curve, and is obtained as follows. First, the surface roughness of the developer bearing member is measured according to JIS B 0671, and a load curve (BAC) is obtained from the obtained roughness curve. FIG. 2 schematically shows the relationship between the roughness curve and the load curve (BAC). In FIG. 2, b1, b2, bi, and bn represent the respective cutting lengths obtained when the roughness curve is cut at a cutting level C parallel to the peak line of the roughness curve, and C represents the roughness curve. It represents the cutting level from the peak, m represents the average line of the roughness curve, L represents the reference length, and tp represents the load length ratio (%) obtained from the formula in FIG. Next, as shown in FIG. 3, the straight line having the smallest inclination among the straight lines passing through the two points A and B where the difference in load length ratio is 40% on the load curve (BAC) obtained as described above. Select. A point where this straight line intersects the axis with a load length rate of 0% is defined as a point C. Further, an intersection between the cutting height level passing through the point C and the load curve is defined as a point H, and an intersection between the load curve and an axis having a load length rate of 0% is defined as a point I. Then, a point J at which the area surrounded by the line segment CH, the curve HI, and the line segment IC is equal to the area of the triangle CHJ is obtained on the axis with a load length ratio of 0%. The distance between this point C and point J is defined as the initial wear height Rpk.

  The range of the initial wear height Rpk on the surface of the developer carrying member 8 in the present invention is preferably 0.2 to 0.8 μm, and more preferably 0.4 to 0.6 μm. If Rpk exceeds 0.8 μm, the amount of developer transported is too large, and it becomes difficult to uniformly charge the developer by friction.

  Rpk and Rzjis on the surface of the conductive resin coating layer 7 can be measured using Surfcoder SE-3500 (trade name) manufactured by Kosaka Laboratory. As measurement conditions, 100 points were measured at a cutoff of 0.8 mm, an evaluation length of 4 mm, and a feed rate of 0.5 mm / s, and the average value was taken. Further, the coefficient of variation of Rzjis at this time is a value obtained by dividing the deviation obtained from the 100 measured values of Rzjis by the average value and expressed as a percentage.

  When the coefficient of variation is larger than 11%, the developer supply stripping roller 11 is likely to cause uneven stripping of the developer, so that the developer layer on the developing sleeve 8 is likely to be non-uniform, and uneven transport or charging unevenness is caused. It is easy to become. Furthermore, problems such as ghost, half-tone unevenness, blade scratches, and developer fusion occur.

  The initial wear height Rpk and the ten-point average roughness Rzjis can be adjusted by the graphitization degree, the particle diameter, and the average circularity of the graphitized particles dispersed in the conductive resin coating layer 7.

  In order to control the surface roughness of the conductive resin coating layer 7 formed on the developer carrier 8 as described above, the volume average particle size, particle size distribution, etc. of the graphitized particles dispersed in the conductive resin coating layer The means for controlling is simple and preferred.

  Next, the conductive resin coating layer 7 will be described.

  The conductive resin coating layer 7 contains at least a binder resin and graphitized particles dispersed in the binder resin. The graphitized particles have a volume average particle size of 0.5 to 4.0 μm and a volume distribution of 10 μm. The proportion of the graphitized particles having the above volume particle diameter is preferably 5.0% by volume or less. When the conductive resin coating layer 7 is as described above, the conductive resin coating layer 7 on the surface of the developer carrier 8 has lubricity, thereby suppressing the charge-up of the developer and forming a uniform uneven surface shape. By doing so, the effect of preventing the fusion of the developer to the surface of the developer carrier 8 and the surface of the developer regulating member 2 is further improved.

  Next, the graphitized particles used in the present invention will be described.

  The graphitized particles used in the present invention form a uniform and minute uneven surface on the surface of the conductive resin coating layer 7 of the developer carrier 8 and at the same time impart lubricity and conductivity to the conductive resin coating layer 7. It is used to make it difficult for developer contamination and developer fusion to occur. Further, the graphitized particles also have an effect of improving uniform and rapid triboelectric chargeability to the developer.

  In the present invention, the graphitized particles dispersed in the conductive resin coating layer 7 of the developer carrier 8 preferably have a graphitization degree P (002) of 0.20 or more and 0.95 or less. When the degree of graphitization P (002) of the graphitized particles is within the above range, the conductive resin coating layer 7 on the surface of the developer carrier 8 can more easily form a uniform uneven surface shape, and the developer The transportability of the toner and the uniform and rapid triboelectric chargeability to the developer are further improved.

The graphitization degree P (002) is said to be the Franklin P value. By measuring the lattice spacing d (002) obtained from the X-ray diffraction diagram of graphite, d (002) = 3.440-0.086 (1- obtained by the P ^2). This P value indicates the proportion of disordered portions of the carbon hexagonal mesh plane stack, and the smaller the P value, the greater the degree of graphitization. The graphitized particles are obtained by solidifying an aggregate such as coke used in the coating layer on the surface of the developer carrying member in Patent Document 1 with tar pitch or the like and firing it at about 1000 to 1300 ° C. after molding. The raw material and manufacturing process of graphitized particles are different from those of artificial graphite obtained by graphitization at about 2500 to 3000 ° C. or crystalline graphite made of natural graphite. Therefore, although the graphitized particles have a slightly lower degree of graphitization P (002) than the crystalline graphite used heretofore, they have high conductivity and lubricity similar to the crystalline graphite used heretofore. Furthermore, the shape of the particles is different from the flake shape or needle shape of crystalline graphite, and is characterized by a lump shape.

  When the graphitization degree P (002) of the graphitized particles is 0.95 or less, the conductivity and lubricity of the conductive resin coating layer 7 are improved, the friction charge becomes non-uniform due to developer charge-up, and the developer carrier 8. It is possible to prevent the developer from fusing to the surface, and there is no deterioration in image quality such as fogging, density unevenness, image density reduction, and vertical stripes. Further, the hardness of the graphitized particles is also suitable, and the surface of the developer regulating member 2 is not damaged. On the other hand, when the graphitization degree P (002) of the graphitized particles is 0.20 or more, the hardness of the graphitized particles themselves is improved, and when the graphitized particles are dispersed in the conductive resin coating layer 7, ultra fine powders are generated. It becomes difficult to prevent the graphitized particles from aggregating in the paint used to form the conductive resin coating layer 7. As a result, a uniform uneven shape is easily formed on the surface of the conductive resin coating layer 7, and the uniform and quick imparting of triboelectric charge to the developer is improved.

The degree of graphitization P (002) is determined by measuring the X-ray diffraction spectrum of the graphitized particles using a powerful fully automatic X-ray diffractometer “MXP18” system (trade name) manufactured by Mac Science Co. (002) is obtained, and d (002) = 3.440−0.086 (1−P (002) ² ).
In order to measure the graphitization degree P (002) of the graphitized particles in the conductive resin coating layer in the present invention, the graphitization of the graphitized particles dispersed in the paint used to form the conductive resin coating layer The degree P (002) may be measured. Also, the graphitized degree P (002) of the graphitized particles dispersed in the paint is determined by the graphitized particles obtained by suction-filtering the paint on a filter paper, washing the graphitized particles of the filtration residue, and drying. It may be measured using.
As the X-ray source, CuKα rays obtained by removing CuKβ rays with a nickel filter are used. High-purity silicon is used as the standard substance, and the calculation is performed from the peak positions of the C (002) and Si (111) diffraction patterns. The main measurement conditions are as follows.
X-ray generator: 18 kW
Goniometer: Horizontal goniometer Monochromator: Working tube voltage: 30.0kV
Tube current: 10.0mA
Measurement method: Continuous method Scan axis: 2θ / θ
Sampling interval: 0.020 deg
Scan speed: 6.000 deg / min
Divergence slit: 0.50deg
Scattering slit: 0.50deg
Receiving slit: 0.30mm
In the present invention, the graphitized particles dispersed in the conductive resin coating layer of the developer carrying member preferably have a volume average particle size of 0.5 μm to 4.0 μm. When the volume average particle diameter of the graphitized particles is 0.5 μm or more, the effect of imparting lubricity to the surface of the conductive resin coating layer is increased, which is preferable. In addition, the ten-point average roughness Rzjis on the surface of the conductive resin coating layer can be easily set within an appropriate range, and it becomes easy to control Rzjis within the above-described range. As a result, the developer transportability and developer fusing are suppressed, and problems such as image density reduction, fogging, density unevenness, and vertical stripes can be easily avoided. On the other hand, when the volume average particle diameter of the graphitized particles is 4.0 μm or less, the ten-point average roughness Rzjis on the surface of the conductive resin coating layer becomes an appropriate size, and the developer on the developer carrier is uniformly distributed. The effect of frictional charging is improved.

  Further, the graphitized particles dispersed in the conductive resin coating layer in the present invention preferably have a ratio of the graphitized particles having a volume particle size of 10 μm or more in the volume particle size distribution of 5.0% by volume or less. When the ratio of graphitized particles having a volume particle size of 10 μm or more in the volume particle size distribution is 5.0% by volume or less, the uneven shape on the surface of the conductive resin coating layer tends to be uniform, and the Rzjis value, its coefficient of variation, and Rpk are It becomes easy to control small. This improves the effect of imparting quick and uniform triboelectric charge to the developer, and prevents the developer from fusing to the surface of the developer carrying member or the surface of the developer regulating member. Problems such as image density unevenness and vertical stripes can be avoided.

  The proportion of particles having a volume particle size of 10 μm or more in the volume average particle size and volume particle size distribution of graphitized particles dispersed in the conductive resin coating layer is a laser diffraction particle size distribution meter Coulter LS-230 particle size distribution meter. (Beckman Coulter, Inc .; trade name). As a measuring method, a small module is used, and isopropyl alcohol (IPA) is used as a measuring solvent. Wash the measurement system of the particle size distribution analyzer with IPA for about 5 minutes, and execute the background function after washing. Next, 1 to 25 mg of a measurement sample is added to 50 ml of IPA. The solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes to obtain a sample solution, and the sample solution is gradually added into the measurement system of the measurement device, and the sample solution is displayed on the screen of the device. Measured by adjusting the sample concentration in the measurement system so that the PIDS (display of sample concentration by polarized scattering intensity difference measurement method) is 45 to 55%, and the particle size calculated from the volume average particle size and volume particle size distribution An abundance ratio can be obtained.

  Particularly preferred graphitized particles used in the present invention are graphitized particles obtained by graphitizing bulk mesophase pitch particles or mesocarbon microbead particles. When such graphitized particles are used, the conductive resin coating layer on the surface of the developer carrying member can more easily form a uniform uneven surface shape and uniform lubricity, thereby suppressing developer charge-up. Further, the effect of preventing the developer from being fused to the surface of the developer carrying member or the surface of the developer regulating member is further improved. Furthermore, the effect of imparting uniform and rapid frictional charge to the developer is further improved by the effect of the graphitized particles contained in the conductive resin coating layer on the surface of the developer carrying member.

  As a method for obtaining graphitized particles particularly preferably used in the present invention, the following methods are preferable, but are not necessarily limited to these methods.

  In the method of obtaining graphitized particles obtained by graphitizing particularly preferred bulk mesophase pitch particles and mesocarbon microbead particles used in the present invention, the raw material is optically anisotropic and consists of a single phase. And a method using particles such as mesocarbon microbeads and bulk mesophase pitch. Use of such bulk mesophase pitch particles and mesocarbon microbead particles is preferable because the degree of graphitization of the obtained graphitized particles can be set to a desired value and a massive shape can be maintained. The optical anisotropy of the above-mentioned raw material is caused by the lamination of aromatic molecules, and the ordering thereof is further developed by graphitization treatment, and graphitized particles having high crystallinity are obtained.

  In the case of using the bulk mesophase pitch, it is preferable to use a material that is softened and melted by heating in order to obtain graphitized particles that are massive and have a high degree of graphitization. The bulk mesophase pitch used in the present invention is obtained, for example, as follows. It can be obtained by extracting β-resin from a coal tar pitch or the like by solvent fractionation, and performing hydrogenation and heavy treatment. Moreover, you may use what was obtained by pulverizing after the said heavyening process, and then removing a solvent soluble part with benzene or toluene. The bulk mesophase pitch in the present invention preferably has a quinoline soluble content of 95% by mass or more. When the quinoline-soluble component is 95% by mass or more, the inside of the particle is liable to be liquid-phase carbonized, the particle becomes granular, and a nearly spherical shape is easily obtained. In order to make the quinoline soluble content 95% by mass or more, it is adjusted by the temperature and treatment time in the heavy treatment.

  Examples of a method for obtaining graphitized particles used in the present invention by graphitization using the bulk mesophase pitch include the following methods. First, the bulk mesophase pitch is finely pulverized to 2 to 25 μm, and this is lightly oxidized by heat treatment in air at a temperature of about 200 to 350 ° C. By this oxidation treatment, only the surface of the bulk mesophase pitch is infusible, and internal melting and fusion are prevented during the graphitizing heat treatment in the next step. This oxidized bulk mesophase pitch preferably has an oxygen content of 5 to 15% by mass. When the oxygen content is 5% by mass or more, there is little fusion between particles during heat treatment, which is preferable. On the other hand, when the oxygen content is 15% by mass or less, it is difficult to oxidize to the inside of the particles, and it is graphitized in a state in which the shape is nearly spherical, and it is easy to obtain graphitized particles that are nearly spherical. The oxygen content of the oxidized bulk mesophase pitch is adjusted by the temperature and time of the oxidation treatment. Next, desired graphitized particles are obtained by firing the oxidized bulk mesophase pitch at about 2000 to 3500 ° C. in an inert atmosphere such as nitrogen or argon.

  The mesocarbon microbeads are obtained by the following method. For example, coal-based heavy oil or petroleum-based heavy oil is heat-treated at a temperature of 300 to 500 ° C. and polycondensed to produce crude mesocarbon microbeads, which are subjected to processes such as filtration, stationary sedimentation, and centrifugation. In this method, the mesocarbon microbeads are separated, washed and purified with a solvent such as benzene, toluene, xylene and the like, and further dried.

  As a method of obtaining graphitized particles for use in the present invention by graphitizing using the mesocarbon microbeads, first, the mesocarbon microbeads that have been dried are first mechanically dispersed with a mild force that does not cause destruction. This is preferable for preventing coalescence of the graphitized particles and obtaining a uniform particle size. Next, the mesocarbon microbeads after the primary dispersion are subjected to primary heat treatment at a temperature of 200 to 1500 ° C. in an inert atmosphere to be carbonized. In order to prevent coalescence of the particles after graphitization and obtain a uniform particle size, it is preferable to mechanically disperse the carbide after the primary heat treatment with a mild force that does not destroy the carbide. The desired graphitized particles can be obtained by firing (secondary heat treatment) the carbide after the secondary dispersion treatment at about 2000 to 3500 ° C. in an inert atmosphere.

  Regardless of the production method, the graphitized particles obtained by the above method should have a volume average particle size of 0.5 to 4.0 μm by classification and a uniform particle size distribution to some extent. It is preferable to make the surface shape of the film uniform.

  Regardless of which raw material is used, the firing temperature for graphitization is preferably from 2000 to 3500 ° C, more preferably from 2300 to 3200 ° C. When the firing temperature is 2000 ° C. or higher, the graphitized particles have a sufficient graphitization degree, and the conductivity and lubricity are improved, thereby preventing the developer from being charged up. As a result, image quality deterioration such as ghosting and image density reduction can be prevented, and further, when an elastic blade is used as a developer regulating member, blade scratches and adhesion of the developer to the blade are prevented. It is possible to prevent the occurrence of stripes and density unevenness. When the firing temperature is 3500 ° C. or less, the graphitization degree of the graphitized particles is in a suitable range, and the triboelectric chargeability to the developer is improved.

  In the conductive resin coating layer, Rzjis may be adjusted, and irregularities-imparting particles may be further added to improve wear resistance. The unevenness-imparting particles used preferably have a volume average particle diameter of 3 to 8 μm. When the volume average particle diameter of the unevenness imparting particles is 3 μm or more, the unevenness formation on the surface of the conductive resin coating layer can be effectively performed. Further, when the volume average particle size is 8 μm or less, the unevenness of the surface of the conductive resin coating layer becomes an appropriate size, and it becomes easy to apply the developer with uniform and rapid frictional charging.

The true density of unevenness imparting particles, 3 g / cm ³ or less, preferably 2.7 g / cm ³ or less, it is better and more preferably from 0.9~2.3g / cm ^3. When the true density of the unevenness-imparting particles is 3 g / cm ³ or less, the dispersibility of the unevenness-imparting particles in the conductive resin coating layer becomes good, and uniform unevenness is easily obtained on the surface of the conductive resin coating layer, which is stable. The developer can be conveyed. Furthermore, it is preferable because a uniform strength of the conductive resin coating layer can be obtained. Furthermore, when the true density of the unevenness-imparting particles is 0.9 g / cm ³ or more, the dispersibility of the unevenness-imparting particles in the conductive resin coating layer is stable, which is preferable.

  Known particles can be used as the irregularity imparting particles. For example, there are resin particles, metal oxide particles, carbonized particles and the like, and a preferable shape is spherical. As these spherical irregularity imparting particles, for example, spherical resin particles obtained by suspension polymerization, dispersion polymerization method or the like are preferably used. Spherical resin particles can provide a suitable surface roughness with a smaller addition amount, and a more uniform surface shape. Examples of such spherical unevenness-imparting particles include acrylic resin particles such as polyacrylate and polymethacrylate, polyamide resin particles such as nylon, polyolefin resin particles such as polyethylene and polypropylene, silicone resin particles, and phenol resin particles. , Polyurethane resin particles, styrene resin particles, benzoguanamine particles, and the like.

  The resin particles obtained by the pulverization method may be used after being subjected to thermal or physical spheronization treatment. Among the irregularity-providing particles, it is particularly preferable to use conductive irregularity-providing particles. That is, by imparting conductivity to the unevenness imparting particles, it is difficult to accumulate charges on the particle surface due to the conductivity, and it is possible to reduce the adhesion of the developer and improve the triboelectric charge imparting property to the developer. .

In the present invention, the conductivity of the irregularity imparting particles is preferably 10 ⁶ Ω · cm or less, more preferably 10 ⁻³ to 10 ⁶ Ω · cm. When the volume resistance value of the unevenness imparting particles is 10 ⁶ Ω · cm or less, it is preferable that the developer is not easily contaminated or fused with the uneven particles as a core, and quick and uniform frictional charging is easily performed. In particular, when conductive spherical unevenness-imparting particles as shown below are used, a better effect can be obtained.

  Particularly preferable conductive spherical unevenness-imparting particles include, for example, low density and highly conductive spherical carbon particles obtained by carbonizing and / or graphitizing by firing spherical resin particles or mesocarbon microbeads. . Examples of spherical resin particles used for carbonization and / or graphitization include resins such as phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, and polyacrylonitrile. And spherical particles.

  More preferable conductive spherical unevenness-imparting particles are mechanochemical on the surface of spherical resin particles made of phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, polyacrylonitrile, etc. Bulk mesophase pitch is coated by a method, and the coated particles are heat-treated in an oxidizing atmosphere, and then calcined in an inert atmosphere or vacuum to be carbonized and / or graphitized.

  In any of the above methods, the conductivity of the spherical unevenness-imparting particles obtained by changing the firing conditions can be controlled, so that the method is preferably used in the present invention. In addition, in some cases, the spherical irregularity-imparting particles obtained by the above-described method may have a conductive metal and / or metal oxidation within a range in which the true density of the conductive spherical irregularity-imparting particles does not become too large in order to further increase the conductivity. An object may be plated.

  The volume average particle diameter of the unevenness imparting particles can be adjusted by classification operation, the degree of sphericity can be adjusted by thermal or mechanical treatment, and the true density can be adjusted by material, molecular weight and plating treatment.

In the present invention, the volume resistance of the conductive resin coating layer of the developer carrying member is preferably 10 ⁻² to 10 ⁵ Ω · cm, more preferably 10 ⁻² to 10 ³ Ω · cm. When the volume resistance of the conductive resin coating layer is 10 ⁵ Ω · cm or less, the developer is not charged up and the developer is not fused to the conductive resin coating layer.

  The volume resistance of the conductive resin coating layer was measured by forming a 7-20 μm conductive resin coating layer on a 100 μm thick PET sheet, and measuring a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Chemical Corporation). Measurement can be performed using a 4-terminal probe. The measurement environment was 20 to 25 ° C. and 50 to 60% RH.

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

  Other conductive fine particles preferably have a number average particle diameter of preferably 1 μm or less, more preferably 0.01 to 0.8 μm. When the number average particle diameter of the other conductive fine particles is 1 μm or less, the volume resistance of the conductive resin coating layer 7 can be easily controlled, and the developer can be easily triboelectrically charged.

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

  The content of other conductive fine particles that can be contained in the conductive resin coating layer together with the graphitized particles is preferably 40 parts by mass or less, more preferably 2 to 35 parts by mass with respect to 100 parts by mass of the binder resin. In this case, the volume resistance can be adjusted to a desired value as described above without impairing other physical properties required for the conductive resin coating layer, which is preferable. When the content of the other conductive fine particles is 40 parts by mass or less, the strength of the conductive resin coating layer does not decrease, which is preferable.

  As the binder resin of the conductive resin coating layer constituting the developer carrying member of the present invention, it is possible to use a known resin that has been conventionally used for the conductive resin coating layer of the developer carrying member. is there. 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, those with releasability such as silicone resin and fluororesin, or excellent mechanical properties such as polyethersulfone, polycarbonate, polyphenylene oxide, polyamide, phenol, polyester, polyurethane, styrene resin, acrylic resin Is more preferable.

  In the present invention, in order to adjust the triboelectric chargeability of the developer carrier, a charge control agent may be contained in the conductive resin coating layer in combination with the graphitized particles. In that case, the content of the charge control agent is preferably 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the binder resin. When the content of the charge control agent is 1 part by mass or more, the effect of charge controllability by addition is exhibited, and when it is 100 parts by mass or less, the dispersion in the conductive resin coating layer is improved and the strength of the conductive resin coating layer is increased. There will be no decline.

  Examples of charge control agents include modified products of nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Onium salts such as phosphonium salts and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) Etc.), metal salts of higher fatty acids; diorganotin oxides such as butyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; diorgana such as thibutyltin borate, dioctyltin borate, dicyclohexyltin borate Suzuboreto like; guanidines, imidazole compounds.

Among these charge control agents, in particular, when a quaternary ammonium salt compound is contained in the conductive resin coating layer, the aggregation of graphitized particles in the coating in the coating step when forming the conductive resin coating layer. Is preferably used, because the surface roughness of the conductive resin coating layer at the time of coating can be made uniform, and the surface properties can be easily controlled.
In addition, the quaternary ammonium salt compound preferably does not have ionic conductivity. If an ion conductive material is used, the water absorption of the conductive resin coating layer tends to increase especially at high temperature and high humidity, and the triboelectric chargeability to the developer may decrease and the developability may deteriorate. is there.

  Further, the inclusion of a quaternary ammonium salt compound that is positively triboelectrically charged with respect to iron powder as a charge control agent in the conductive resin coating layer improves the favorable triboelectric chargeability to the developer. More preferred. At this time, the conductive resin coating layer contains a binder resin having at least one of an amino group, ═NH group, and —NH— bond in the resin structure. It is further preferable in view of imparting a good triboelectric charge to a high negative triboelectric developer.

  By providing a conductive resin coating layer formed on the developer carrier in combination with the quaternary ammonium salt compound and the binder resin having the specific structure, the degree of spheroidization Therefore, it is possible to control the application of triboelectric charge to the negative triboelectric developer. As a result, it is possible to prevent the developer from being charged up on the developer carrying member, to prevent developer fusion from occurring on the surface of the conductive resin coating layer, and to maintain uniform triboelectric charging stability of the developer. As a result, it is possible to provide a high-definition image having environmental stability and long-term stability.

  The reason for this is not clear, but is presumed as follows. A quaternary ammonium salt compound which is preferably used in the present invention and is positively triboelectrically charged to iron powder itself, when added, has an amino group, ═NH group or —NH— bond in the structure. The binder resin itself is uniformly dispersed in the binder resin containing at least one, and further incorporated into the structure of the binder resin when the conductive resin coating layer is formed. It is thought to have negative frictional charging properties. For this reason, it is presumed that the negative triboelectric charge developer works in a direction that prevents the negative triboelectric charge amount from becoming excessive in the developer, and as a result, the negative triboelectric charge amount can be appropriately controlled.

  As the quaternary ammonium salt compound having the above-described function, which is preferably used in the present invention, any quaternary ammonium salt compound may be used as long as it has a positive triboelectric chargeability with respect to iron powder. The compound represented by these is mentioned.

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl group, and R _{1 to} R _4. May be the same or different, and X ⁻ represents an anion of an acid.)
In the above general formula, as the acid ion X ⁻ , an organic sulfate ion, an organic sulfonate ion, an organic phosphate ion, a molybdate ion, a tungstate ion, a heteropolyacid ion containing a molybdenum atom, or a tungsten atom is preferably used. .

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

  In addition, as a preferable binder resin containing at least one of an amino group, ═NH group or —NH— bond in the structure in combination with the quaternary ammonium salt, it is produced using a nitrogen-containing compound as a catalyst in the production process. And phenol resins, polyamide resins, epoxy resins using polyamide as a curing agent, urethane resins, or copolymers containing these resins in part. The quaternary ammonium salt compound is easily taken into the structure of the conductive resin coating layer when forming the conductive resin coating layer containing these binder resins.

  In the present invention, the phenol resin that can be suitably used in combination with the quaternary ammonium salt includes a nitrogen-containing compound as a catalyst in the production process, for example, an acidic catalyst such as ammonium sulfate, ammonium phosphate, ammonium sulfamate, Examples thereof include phenol resins produced using ammonium salts or amine salts such as ammonium carbonate, ammonium acetate, and ammonium maleate. In addition, 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, dimethyl Ethanolamine, diethylethanolamine, ethyldiethanolamine, n-butyldiethanolamine, di-n-butylethanolamine, triisopropanolamine, ethylenediamine, hexa Amino compounds such as tylenetetramine; pyridines such as pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, and derivatives thereof; , 4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, imidazole such as 2-heptadecylimidazole, and nitrogen-containing heterocyclic compounds such as derivatives thereof. The phenol resin manufactured using is mentioned.

  In the present invention, the polyamide resin suitably used in combination with the quaternary ammonium salt is, for example, nylon 6, 66, 610, 11, 12, 9, 13, Q2 nylon, or the like, or a main component thereof. Any of Nylon copolymer, N-alkyl-modified nylon, N-alkoxylalkyl-modified nylon, and the like can be suitably used. Furthermore, any resin containing a polyamide resin such as various resins modified with polyamide such as a polyamide-modified phenol resin or an epoxy resin using a polyamide resin as a curing agent may be used. Can be used.

  In the present invention, any urethane resin suitably used in combination with the quaternary ammonium salt as the binder resin and constituting the conductive resin coating layer may be used as long as it contains a urethane bond. Can do. This urethane bond is obtained by polyaddition reaction of polyisocyanate and polyol. Polyisocyanates that are the main raw materials for this polyurethane resin include TDI (tolylene diisocyanate), pure MDI (diphenylmethane diisocyanate), polymeric MDI (polymethylene polyphenyl polyisocyanate), TODI (tolidine diisocyanate), NDI (naphthalene diisocyanate), and the like. Aromatic polyisocyanates such as: HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), XDI (xylylene diisocyanate), hydrogenated XDI (hydrogenated xylylene diisocyanate), aliphatic MDI (dicyclohexylmethane diisocyanate), etc. And polyisocyanates.

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

  Next, the configuration of the developer carrier in the present invention will be described. The developer carrier in the present invention has at least a base and a conductive resin coating layer formed on the surface of the base.

  The base of the developer carrying member used in the present invention includes a cylindrical member, a columnar member, a belt-like member, etc. In a developing method that is not in contact with the drum, a rigid cylindrical tube such as metal or a solid member is used. A rod is preferably used. As such a substrate, a non-magnetic metal or alloy such as aluminum, stainless steel, or brass, which is molded into a cylindrical shape or a cylindrical shape, and subjected to polishing, grinding, or the like, is preferably used. 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 or 20 μm or less, more preferably 10 μm or less, and the gap between the developer carrying member and the photosensitive drum may be varied, for example, through a uniform spacer with respect to the vertical surface. When the developing sleeve is rotated, the fluctuation of the gap with the vertical surface is preferably 30 μm or less, 20 μm or less, and more preferably 10 μm or less. Aluminum is preferably used because of material cost and ease of processing. The base of the present invention may be a cylindrical member having a layer structure including a rubber or elastomer such as urethane, EPDM, or silicon on a metal core.

  Next, the composition ratio of each component constituting the conductive resin coating layer will be described. This composition ratio is a particularly preferable range in the present invention, but the present invention is not limited to this.

  The content of graphitized particles dispersed in the conductive resin coating layer is preferably 40 to 15.0 parts by mass, more preferably 50 to 120 parts by mass with respect to 100 parts by mass of the binder resin. The formation of a uniform surface irregularity shape of the carrier and the improvement of lubricity, uniform and rapid imparting of triboelectric charge to the developer, and the effect of preventing the fusion of the developer are more exhibited. When the content of the graphitized particles is 40 parts by mass or more, the effect of adding the graphitized particles is large. When the content of the graphitized particles is 150 parts by mass or less, the uneven shape of the conductive resin coating layer is easily formed and adhesion is improved. Abrasion resistance is improved.

The layer thickness of the conductive resin coating layer having the above-described configuration is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 4 to 20 μm in order to obtain a uniform layer thickness. It is not limited to the layer thickness. Although these layer thicknesses depend on the material used for the conductive resin coating layer, they can be obtained when the adhesion mass is about 4000 to 20000 mg / m ² .

  As a method for obtaining the conductive resin coating layer in the present invention, for example, each component constituting the conductive resin coating layer can be dispersed and mixed in a solvent to form a paint and applied onto the substrate. It is. 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 the dispersion and mixing of the components constituting the conductive resin coating layer. Moreover, as a coating method, well-known methods, such as a dipping method, a spray method, and a roll coat method, are applicable.

  Next, the developer used in the developing device of the present invention will be described. The developer (toner) used in the developing device of the present invention is a one-component developer (toner), and is preferably a non-magnetic one-component developer (toner). When the developer is a one-component developer (toner) or a non-magnetic one-component developer (toner), the effect of easily controlling the developer coating state on the surface of the developer carrying member to a more uniform thickness is improved.

  Further, the one-component developer used in the developing device of the present invention has an average circularity of 0.970 or more in developer particles having an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring device for developer particles. Preferably there is. When the average circularity of developer particles having an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring apparatus for a one-component developer is 0.970 or more, the developer is deteriorated even in continuous copying over a long period of time. It is hard to occur, and the developer is uniformly and stably coated on the developer carrier to prevent the developer from fusing to the surface of the developer carrier and the surface of the developer regulating member, and the developer is always uniformly and quickly. It becomes easy to triboelectrically charge. Furthermore, even under different environmental conditions, there is an effect that the uniform and rapid triboelectric chargeability of the developer on the surface of the developer carrier is less likely to change, and problems such as image density reduction, image density unevenness, vertical stripes, and fogging. And a high-quality image with a high image density can be stably obtained.

  In the conventional developing apparatus, if the average circularity of the developer particles is high within the above range, the flowability of the developer is increased, so that the individual developer particles can move freely and deteriorate the developer. However, in the developing device of the present invention, the uneven shape on the surface of the developer carrier is small and uniform, and further development on the developer carrier is difficult. Since the contact pressure of the agent regulating member can be reduced, the developer can be stably and uniformly frictionally charged without deteriorating the developer.

  The average circularity of the developer particles in the present invention is used as a simple method for quantitatively expressing the shape of the developer particles. For example, the flow type particle image analyzer FPIA-2100 manufactured by Sysmex Corporation (trade name) ). In the present invention, the measurement is performed in an environment of 23 ° C. and 60% RH, and for each developer particle, an equivalent circle diameter which is the diameter of a circle having the same area as the projected area of the particle image of each developer particle. The circularity of each developer particle is determined by the following formula (1) for the developer particles having an equivalent circle diameter of 0.60 μm to 400 μm, and the developer particles having an equivalent circle diameter of 3 μm to 400 μm. The value obtained by dividing the sum of the circularity by the total number of particles is defined as the average circularity.

Circularity a = L ₀ / L (1)
[In the formula, L ₀ indicates the circumference of a circle having the same projected area as the developer particle image, and L is the image processing resolution when the image processing resolution is 512 × 512 (pixels of 0.3 μm × 0.3 μm). Indicates the perimeter of the projected particle image. ]
The average circularity used in the present invention is an index of the degree of unevenness of the developer particles, and indicates 1.00 when all the developer particles are perfectly spherical, and the average circularity is increased as the surface shape of the developer particles becomes more complicated. Is a small value. The measuring device “FPIA-2100” (trade name) used in the present invention calculates the circularity of each developer particle, and then calculates the average circularity by calculating the circularity of each developer particle. A calculation method is used in which 0.4 to 1.0 is divided into 61 divided classes, and the average circularity is calculated using the center value and frequency of the dividing points. However, the difference between the average circularity calculated by this calculation method and the average circularity calculated by the calculation formula using the sum of the circularity of each developer particle is very small and can be substantially ignored. In the present invention, for the purpose of handling data such as shortening the calculation time and simplifying the calculation formula, the concept of the calculation formula using the sum of the circularity of each developer particle is used, You may use the average circularity calculated | required by such a calculation method changed partially. Furthermore, “FPIA-2100” (trade name), which is a measuring apparatus used in the present invention, is compared with “FPIA-1000” (trade name), which has been conventionally used for calculating the shape of developer particles. In addition, by improving the magnification of the processed particle image and further improving the processing resolution of the captured image (256 × 256 → 512 × 512), the accuracy of measuring the shape of the developer particles has been improved, thereby making sure that the fine particles are more reliable. It is a device that has achieved a good capture. Therefore, when it is necessary to more accurately measure the shape and particle size distribution of the developer particles as in the present invention, “FPIA-2100” can be obtained more accurately regarding the shape and particle size distribution of the developer particles. (Product name) is more useful.

As a specific measurement method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant in 200 to 300 ml of water from which impurities have been removed in advance, and a measurement sample is further added to 0.1 to 0.5 ml. Add about 0.5g. The suspension in which the sample is dispersed is dispersed with an ultrasonic disperser for 2 minutes, and the circularity distribution of the developer particles is measured at a dispersion concentration of 0.2 to 10,000,000 / μl. As an ultrasonic disperser, for example, the following apparatus can be used, and the following dispersion conditions can be used.
UH-150 (manufactured by SMT Corporation; trade name)
OUTPUT level: 5
The outline of constant mode measurement is as follows.

  The sample dispersion is passed through a flow path (expanded along the flow direction) of a flat and flat flow cell (thickness: about 200 μm). The strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other so as to form an optical path that passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the developer particles flowing through the flow cell, so that each developer particle is parallel to the flow cell. Photographed as a two-dimensional image having a certain range. From the area of the two-dimensional image of each developer particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. The circularity of each developer particle is calculated from the projected area of the two-dimensional image of each developer particle and the perimeter of the projected image using the above circularity calculation formula.

  The developer (toner) used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method. In the case where a polymerized toner manufacturing method is used for the developer (toner) manufacturing method, the toner can be manufactured by the following manufacturing method. A monomer system in which a release agent, polar resin, colorant, charge control agent, polymerization initiator, cross-linking agent and other additives are added to the monomer and dissolved or dispersed uniformly by a homogenizer, ultrasonic disperser, etc. Is dispersed in an aqueous phase containing a dispersion stabilizer by an ordinary stirrer, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the monomer-based droplets have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 ° C. to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction. Further, in order to remove unreacted monomers and by-products that cause odors during toner fixing, the temperature is increased in the latter half of the reaction or after the completion of the reaction. The partial aqueous medium may be distilled off. After completion of the reaction, the produced toner particles are collected by filtration and washing and dried. In the suspension polymerization method, it is usually preferable to use 300 parts by mass to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

  Examples of the monomer that can be used in the method for producing the polymerized toner include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Acrylic esters such as phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, Methacryl Stearyl, phenyl methacrylate, dimethylaminoethyl methacrylate, such as methacrylic acid esters other acrylonitrile diethylaminoethyl methacrylate, methacrylonitrile, and such monomers of acrylamide. These monomers can be used alone or in admixture of two or more. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of developing properties and durability of the toner.

  Examples of the crosslinking agent that can be used in the method for producing the polymerized toner include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate. Examples thereof include carboxylic acid esters having two double bonds; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. Particularly preferred is divinylbenzene. As a preferable addition amount of a crosslinking agent, it is preferable that a crosslinking agent is 0.01 mass part-1.0 mass part per 100 mass parts of monomers. More preferably, it is 0.1 mass part-0.9 mass part.

  Examples of the polymerization initiator that can be used in the method for producing the polymerized toner include an oil-soluble initiator and / or a water-soluble initiator. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, cumene Examples thereof include peroxide-based initiators such as hydroperoxide. Examples of water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, azobis (isobutylamidine) hydrochloride, 2,2′-azo. Examples include sodium bisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide. Furthermore, in order to control the degree of polymerization of the polymerizable monomer, it is possible to add and use a chain transfer agent, a polymerization inhibitor or the like.

  In addition, any appropriate dispersion stabilizer is used for the dispersion medium used in the method for producing the polymerized toner. Specifically, for example, as an inorganic compound, tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, Examples thereof include fine powders of inorganic compounds such as calcium sulfate, barium sulfate, bentonite, silica, and alumina. As the organic compound, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salt, polymethacrylic acid and its salt, starch and the like are used. These dispersion stabilizers are preferably used in an amount of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the monomer.

  As a release agent that can be used in the above-described method for producing a polymerized toner, a wax that is solid at room temperature is preferable. Specific examples include paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, and derivatives such as graft compounds and block compounds. These waxes can also be suitably used in the pulverized toner manufacturing method.

  It is preferable to add the wax so that the toner usually contains 5% by mass to 30% by mass. When a wax is added as a release agent so as to contain 5% by mass or more in the toner, the high temperature offset resistance is improved, and the back side image does not cause an offset phenomenon even when fixing a double-sided image. When the wax content in the toner is 30% by mass or less, the toner particles do not coalesce during granulation in the production by the polymerization method, and a toner having a narrow particle size distribution can be obtained. Further, the encapsulation of the wax becomes sufficient, the developability, transferability and blocking resistance are improved, and the uniformity of the image is also improved.

  As the charge control agent that can be used in the method for producing the polymerized toner, known ones can be used, but those having no polymerization inhibition or water phase migration are preferable. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, guanidine derivatives, imidazole derivatives, amine compounds, and the like. Examples of negative charge control agents include metal-containing salicylic acid copolymers, metal-containing monoazo dye compounds, urea derivatives, styrene-acrylic acid copolymers, and styrene-methacrylic acid copolymers. The addition amount of these charge control agents is preferably 0.1% by mass to 10% by mass of the monomer.

  Known colorants can be used as the colorant that can be used in the method for producing the polymerized toner.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  In addition, it is necessary to pay attention to the polymerization inhibitory property and water phase transferability of the colorant used in the method for producing the polymerized toner. The colorant is preferably used after being subjected to surface modification, for example, a hydrophobic treatment without polymerization inhibition. In particular, dyes and carbon blacks have a polymerization inhibition property, so care must be taken when using them. As a preferred method for surface-treating the dye system, there can be mentioned a method in which a polymerizable monomer is polymerized in the presence of these dyes and the resulting colored polymer is added to the monomer system. Carbon black may be treated with a substance that reacts with the surface functional group of carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

  The particle size distribution control and particle size control of the polymerized toner can be controlled by changing the type and amount of the poorly water-soluble inorganic salt and the dispersing agent that acts as a protective colloid, as well as mechanical equipment conditions such as the rotor speed and path. It can be performed by controlling the stirring conditions such as the number of times and the shape of the stirring blade, the shape of the container, or the solid content concentration in the aqueous solution. By these methods, a toner having a predetermined particle size and particle size distribution can be obtained.

  When the pulverized toner manufacturing method is used for the developer (toner) manufacturing method, the pulverized toner can be manufactured by the following manufacturing method. As a pulverized toner manufacturing method, a known method is used. For example, binder resin, charge control agent, if necessary, wax, magnetic substance, colorant, other additives, etc. are thoroughly mixed by a mixer such as a Henschel mixer or a ball mill, and then heated rolls, kneaders, extruders Using such a heat kneader, the mixture is melt-kneaded, cooled, solidified, pulverized, and classified to obtain colored particles. Surface treatment may be performed as necessary. Thereafter, an inorganic fine powder is added and mixed to obtain a toner. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier using the Coanda effect in terms of production efficiency.

  For spheroidization and surface smoothing for the purpose of improving transferability, a pulverized toner particle is dispersed in water and heated, a heat treatment method through which it passes through a hot air current, and mechanical energy is applied. And mechanical impact method. In the mechanical impact method, a thermomechanical impact in which the treatment temperature is a temperature in the vicinity of the glass transition point Tg (Tg ± 10 ° C.) of the toner particles is preferable from the viewpoint of aggregation prevention and productivity.

  Examples of the binder resin that can be used in the method for producing the pulverized toner include polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-p-chlorostyrene copolymer, styrene such as styrene-vinyltoluene copolymer, and the like. Homopolymers of the substituted products and their copolymers; styrene and acrylate esters such as styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-n-butyl acrylate copolymer Copolymers; Copolymers of styrene and methacrylic esters such as styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-n-butyl methacrylate copolymer; styrene and acrylic acid ester and methacrylic acid Multi-component copolymer with acid ester; styrene-acrylonitrile copolymer Styrene and other such as styrene-vinyl methyl ether copolymer, styrene-butadiene copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid ester copolymer Styrene copolymer with vinyl monomer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyester, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid, phenol resin, aliphatic or alicyclic hydrocarbon resin, Examples include petroleum resin and chlorinated paraffin. These can be used alone or in combination. In particular, binder resins for toners used in pressure fixing systems include low molecular weight polyethylene, low molecular weight polypropylene, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, higher fatty acids, polyamide resins, and polyester resins. Can be used alone or in combination. The comonomer for constituting the above styrene copolymer includes acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid. Acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, monocarboxylic acid having a double bond such as acrylamide or a derivative thereof, maleic acid, butyl maleate, methyl maleate, Examples thereof include dicarboxylic acids having a double bond such as dimethyl maleate and derivatives thereof.

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

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

  In order to improve the image quality, it is preferable that the toner has a weight average particle diameter of 4 μm to 8 μm for both the polymerized toner and the pulverized toner. When the weight average particle size is 4 μm or more, it is preferable because peelability and transferability are improved, and image uniformity is improved. Further, it is preferable that the thickness is 8 μm or less because deterioration of image quality such as scattering can be prevented.

  An external additive may be added to the toner for the purpose of imparting various properties.

The external additive preferably has a particle size of 1/10 or less of the volume average diameter of the toner particles from the viewpoint of durability when added to the toner. The particle size of the external additive means the average particle size obtained by observing the surface of the toner particles with an electron microscope. As external additives for the purpose of imparting these characteristics, for example, the following are used.
1) Fluidity imparting agent: metal oxide (silicon oxide, aluminum oxide, titanium oxide), carbon black, and carbon fluoride. Those subjected to hydrophobic treatment are more preferable.
2) Abrasive: metal oxide (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide), nitride (silicon nitride), carbide (silicon carbide) and metal salt (calcium sulfate, barium sulfate, calcium carbonate) ).
3) Lubricant: fluororesin powder (vinylidene fluoride, polytetrafluoroethylene) and fatty acid metal salt (zinc stearate, calcium stearate).
4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide) and carbon black.

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

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

[Graphitized Particle Production Example A-1]
As a raw material for graphitized particles, β-resin is extracted from coal tar pitch by solvent fractionation, and after heavy treatment by hydrogenation, bulk soluble mesophase is removed by removing the solvent soluble component with toluene. Got the pitch. This bulk mesophase pitch is finely pulverized, oxidized in air at about 300 ° C., and then first baked and carbonized at 1200 ° C. in a nitrogen atmosphere, followed by secondary calcination at 3000 ° C. in a nitrogen atmosphere. Graphitized and further classified to obtain graphitized particles A-1 having a volume average particle size of 3.1 μm.
Table 1 shows the physical properties of the graphitized particles A-1.

[Graphitized Particle Production Examples A-2 to 7 and A-11 to 12]
Graphitized particles A-2 to A-7 and A-11 to A-12 were produced in the same manner as in the production example of graphitized particles A-1, except that the firing temperature and the particle size were as shown in Table 1, respectively. . The physical properties of the obtained graphitized particles A-2 to 7 and A-11 to 12 are shown in Table 1, respectively.

[Graphitized Particle Production Example A-8]
As raw materials for graphitized particles, heavy coal oil is heat-treated, and the resulting crude mesocarbon microbeads are centrifuged, washed with benzene, dried and then mechanically dispersed in an atomizer mill. Carbon microbeads were obtained. The mesocarbon microbeads were subjected to primary firing at 1200 ° C. in a nitrogen atmosphere and carbonized, followed by secondary dispersion in an atomizer mill, followed by secondary firing at 3000 ° C. in a nitrogen atmosphere for graphitization and further classification. As a result, graphitized particles A-8 having a volume average particle size of 3.0 μm were obtained. Table 1 shows the physical properties of the graphitized particles A-8.

[Graphitized Particle Production Example A-9]
As a raw material for the graphitized particles, a mixture of 70 parts of petroleum coke and 30 parts of tar pitch is used. The mixture is kneaded at a temperature equal to or higher than the softening point of tar pitch, extruded, and subjected to primary firing at 1000 ° C. in a nitrogen atmosphere. And then carbonized and subsequently impregnated with coal tar pitch, followed by secondary firing in a nitrogen atmosphere at 2800 ° C. to graphitize, and further pulverize and classify to graphitized particles A-9 having a volume average particle size of 4.3 μm Got. Table 1 shows the physical properties of the graphitized particles A-9.

[Graphitized particle production examples A-10 and A-13]
Graphitized particles A-10 and A-13 were produced in the same manner as Graphitized Particle Production Example A-9, except that the firing temperature and particle size of the graphitized particles were changed. The physical properties of the obtained graphitized particles A-10 and A-13 are shown in Table 1, respectively.

[Developer carrier production example B-1]
-300 parts of a resol-type phenol resin solution (containing 50% methanol) produced using ammonia as a catalyst-100 parts of graphitized particles (A-1)-150 parts of methanol Add 1 mm diameter glass beads to the above materials as media particles, Dispersion was performed with a sand mill, and the solid content of the dispersion was diluted to 40% with methanol to obtain a coating solution. The volume average particle diameter of the graphitized particles dispersed in the coating solution was 1.8 μm, and the ratio of the graphitized particles having a volume particle diameter of 10 μm or more was 2.5% by volume. Further, the graphitized degree P (002) of the dispersed graphitized particles was 0.39. Table 2 shows the physical properties of the graphitized particles dispersed in the coating solution.

  Using this coating solution, a conductive resin coating layer is formed on an aluminum cylindrical tube having an outer diameter of 16 mmφ by a spray method, followed by heating and curing in a hot air drying furnace at 150 ° C./30 minutes for developer carrier B- 1 was produced. When the surface roughness of developer carrier B-1 was measured, Rzjis was 3.5 μm, Rzjis had a coefficient of variation of 9.4%, and Rpk was 0.52 μm. Table 2 shows the constitution and physical properties of the conductive resin coating layer of the obtained developer carrier B-1.

[Developer carrier production examples B-2 to 9]
In the developer carrier production example B-1, except that the graphitized particles A-1 were changed to A-2 to A-9, respectively, the coating liquid was prepared in the same manner as in the developer carrier production example B-1. Each developer carrier B-2 to 9 was prepared. Table 2 shows the constitution and physical properties of the conductive resin coating layers of the obtained developer carriers B-2 to B-9.

[Developer carrier production example B-10]
In developer carrier production example B-1, the graphitized particles A-1 are changed to A-3, and the quaternary ammonium salt compound represented by the following formula in which the triboelectric charge amount with iron powder is positive. Except for adding 50 parts of (2), the coating liquid was dispersed in the same manner as in Developer Carrier Production Example B-1, to produce Developer Carrier B-10. Table 2 shows the constitution and physical properties of the conductive resin coating layer of the resulting developer carrier B-10.

[Developer carrier production examples B-11 to 12]
In the production of developer carrier production example B-10, the same procedure as in developer carrier production example B-10 was performed except that graphitized particle A-3 was changed to A-7 and A-10, respectively. A coating solution was prepared for each of developer carriers B-11 to B-12. Table 2 shows the constitution and physical properties of the conductive resin coating layers of the obtained developer carriers B-11 to B-12.

[Developer carrier production examples B-13 to 16]
In developer carrier production example B-1, developer carrier production example B except that graphitized particles A-1 were changed to A-11, A-12, A-10, and A-13, respectively. The coating liquids were respectively prepared in the same manner as in -1, and developer carriers B-13 to 16-16 were produced. Table 2 shows the constitution and physical properties of the conductive resin coating layer of the obtained developer carrier B-13-16.

[Developer Carrier Production Example B-17]
In developer carrier production example B-10, except that graphitized particle A-3 was changed to A-11, a coating liquid was prepared in the same manner as developer carrier production example B-10, Developer carrier B-17 was produced. Table 2 shows the constitution and physical properties of the conductive resin coating layer of the resulting developer carrier B-17.

[Developer Production Example 1]
A polymerized toner was prepared by the following procedure.
Add 3 parts of tricalcium phosphate to 900 parts of ion-exchanged water heated to 60 ° C., and stir at 10,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo; trade name). Created media.

  Further, the following formulation was put into a homogenizer (manufactured by Nippon Seiki Co., Ltd.), heated to 60 ° C., stirred at 9,000 rpm, dissolved and dispersed.

Styrene 150 parts n-butyl acrylate 50 parts C.I. I. Pigment Blue 15: 3 18 parts ・ Aluminium salicylate compound 2 parts (Bontron E-88: manufactured by Orient Chemical Co., Ltd., trade name)
Polyester resin 15 parts (polycondensation product of propylene oxide modified bisphenol A and isophthalic acid, Tg = 65 ° C., weight average molecular weight (Mw) = 10000, number average molecular weight (Mn) = 6000)
Stearate stearate 30 parts (differential scanning calorimeter (DSC) main peak 60 ° C.)
-0.4 parts of divinylbenzene 5 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) polymerization initiator was dissolved in this to prepare a monomer composition.

The monomer composition was charged into the aqueous medium, and granulated by stirring at 8,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo; trade name) in a nitrogen atmosphere at 60 ° C. .
Then, the temperature was raised to 70 ° C. over 2 hours while being transferred to a propeller type stirring device, and further heated up to 80 ° C. at a rate of temperature rise of 40 ° C./h after 4 hours, and reacted at 80 ° C. for 5 hours. To produce polymer particles. After completion of the polymerization reaction, the slurry containing the particles is cooled, washed with an amount of water 10 times that of the slurry, filtered and dried, and then the particle size is adjusted by classification to form base toner particles (weight average particle size of 6. 1 μm and an average circularity of 0.981) were obtained.

  To 100 parts of the toner particles, 1.0 part of hydrophobic silica fine powder surface-treated with hexamethylene disilazane (average primary particle diameter 7 nm), 0.15 part of rutile titanium oxide fine powder (average primary particle diameter 45 nm). ), 0.5 part of rutile titanium oxide fine powder (average primary particle size 200 nm) is dry-mixed for 5 minutes with a Henschel mixer (Mitsui Mining Co., Ltd.), and the non-magnetic one-component developer (toner) used in the present invention is mixed. Obtained.

(Examples 1-12, Comparative Examples 1-5)
The developer carrying member thus manufactured was modified with a cyan cartridge EP-85 (manufactured by Canon Inc .; product name) for a commercially available laser beam printer LBP-2510 (Canon Corp .; product name) to produce a developing device. This developing apparatus was mounted on the above laser beam printer, filled with the nonmagnetic one-component developer (toner) produced in Developer Production Example 1, and evaluated by the following method.
In remodeling cyan cartridge EP-85 (manufactured by Canon Inc .; trade name) to produce a developing device, charging assistance mounted on the developer carrier from cyan cartridge EP-85 (manufactured by Canon Inc .; trade name) The roller was removed, and the rollers attached to the left and right sides of the developer carrying member were changed to those having a large diameter, and the SD distance between the developer carrying member and the photosensitive drum was 280 μm. Further, as an elastic regulating blade (sometimes referred to as a blade) as a developer regulating member, the surface of the phosphor bronze plate has a thickness of 30 μm made of a copolymer of polyamide and polyether (copolymerization ratio 1: 1). A rubber layer attached was used. Further, the contact pressure (linear pressure) of the elastic regulating blade with respect to the developer carrying member was adjusted to be 13 N / m. At this time, the contact width of the elastic regulating blade with respect to the developer carrying member was 0.8 mm.

  Further, the rubber layer Rzjis of the elastic regulating blade at the portion in contact with the developer carrying member had a thickness of 0.6 μm. Further, the distance NE between the most upstream contact position between the elastic regulating blade and the developer carrier and the free end was adjusted to 1 mm.

  Next, the developing device was installed in the cyan station of the laser beam printer, and dummy cartridges were installed in the other stations, and single color evaluation was performed.

The development conditions were the following jumping development conditions.
The dark portion potential (Vd) of the non-image portion of the photosensitive drum was set to -500 V, and the bright portion potential (Vl) of the image on which the electrostatic latent image was formed was set to -100 V. Further, the developer carrier is subjected to jumping development using a DC bias of −250 V as a developing bias and an AC bias composed of a rectangular wave having a frequency of 3 kHz and a peak-to-peak voltage (Vpp) of 1.8 kV. It was.

  The evaluation environment is a low temperature / low humidity environment of 15 ° C./10% RH (may be expressed as L / L), and a normal temperature / normal humidity environment of 23 ° C./60% RH (may be expressed as N / N). Durability tests were conducted under three conditions: under 30 ° C / 85% RH high temperature / high humidity environment (sometimes referred to as H / H), and up to 10,000 images with a print ratio of 2%. Print out and evaluate the image density, fog, halftone uniformity, vertical stripes, and other image quality of the resulting image, as well as the toner charge amount (Q / M) and toner transport on the developer carrier before and after the durability test. The amount (M / S) of the toner carrier on the developer carrier and the elastic regulation blade after the durability test was evaluated.

  The above evaluation was performed by the following method.

(1) Image density Using a normal copying machine plain paper (basis weight 75 g / m ² ), a solid image was output before and after the durability test, and the density was measured for evaluation. The image density was measured using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co., Ltd .; product name), the relative density with respect to an image of a white background portion having a document density of 0.00, and the image density was evaluated according to the following criteria.
A: Very good 1.40 or more B: Good 1.35 or more, less than 1.40 C: No practical problem 1.00 or more, less than 1.35 D: Practical problem Less than 1.00

(2) Fog The whiteness of the white portion of the printout image and the transfer paper, the fog density (%) of the image at the end of the endurance test measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd .; trade name) The image fog was evaluated based on the following criteria. An amberlite filter was used as the filter.
A: Very good Less than 0.5% B: Good 0.5% or more and less than 1.0% C: No practical problem 1.0% or more and less than 1.5% D: Practical problem 1.5 %more than

(3) Halftone uniformity (difference between haze and band)
The formed image was visually observed and evaluated according to the following criteria for the haze-like shade difference generated in the halftone and the strip-like shade difference running in the image formation progress direction.
A: Very good (cannot confirm the difference in shading in the image)
B: Good (a slight difference in light and shade can be confirmed if you look closely)
C: No problem in practical use.
D: There is a problem in practical use (the difference in density can be confirmed clearly)

(4) Longitudinal streaks For vertical streaks that occur in the halftone or solid black and run in the direction of image formation, the formed images were observed visually and evaluated according to the following criteria.
A: Very good (No vertical stripes can be confirmed in the image)
B: Good (If you look closely, you can see vertical stripes with halftone lightly)
C: No problem in practical use (Slight in halftone, but vertical stripe cannot be confirmed in solid black)
D: Practical problem (can be confirmed clearly in halftone, minor in solid black, but vertical stripes can be confirmed)
E: Inferior (a lot of vertical stripes can be confirmed with solid black)

(5) Toner charge amount (Q / M) and toner transport amount (M / S)
The toner carried on the developer carrying member (sometimes referred to as a sleeve) is collected by suction with a metal cylindrical tube and a cylindrical filter, and the amount of charge Q stored in the condenser is collected through the metal cylindrical tube. From the toner mass M and the area S where the toner is sucked, a charge amount Q / M (mC / kg) per unit mass and a toner mass M / S (dg / m ² ) per unit area are calculated, respectively. The charge amount (Q / M) and the toner transport amount (M / S) were used.

(6) Toner fusion on developer carrier The surface of the developer carrier after the endurance test was observed at a magnification of about 200 times using an ultra-deep shape measurement microscope manufactured by KEYENCE. Evaluation based on the criteria of.
A: Very good (only minor contamination is observed)
B: Good (slight fusion is observed)
C: No problem in practical use (a minute granular toner fusion product is partially observed)
D: Practical problem (significant fusion is observed over the entire surface)

(7) Toner fusion on the elastic regulating blade The surface of the contact portion with the developer carrying member of the elastic regulating blade after the endurance test was observed at a magnification of about 200 times using a KEYENCE ultra-deep shape measuring microscope. The degree of toner fusion was evaluated based on the following criteria.
A: Very good (only minor contamination is observed)
B: Good (a fine granular toner fusion product is slightly observed)
C: No problem in practical use (a small but slightly elongated toner fusion product is partially observed in the circumferential direction)
D: Practical problem (significant streak-like fusion is observed)

  Table 3 summarizes the evaluation results of the above image quality (image density, fog, halftone uniformity, vertical stripes). Table 4 shows evaluation results of toner charge amount (Q / M) and toner transport amount (M / S) on the developer carrier (sleeve) and toner fusion on the developer carrier and the elastic regulation blade surface. .

(Example 13)
Example 1 except that the contact pressure (linear pressure) of the elastic regulating blade to the developer carrying member is 7 N / m and the rubber layer Rzjis of the elastic regulating blade is changed to 0.9 μm. In the same manner as in Example 1, a developing device was produced and evaluated. The obtained results are shown in Tables 3 and 4.

(Example 14)
Example 1 except that the contact pressure (linear pressure) of the elastic regulating blade to the developer carrying member is 20 N / m and the rubber layer Rzjis of the elastic regulating blade is changed to 0.3 μm. A developing device was manufactured and evaluated in the same manner as described above. The obtained results are shown in Tables 3 and 4.

(Comparative Example 6)
In Example 13, a developing device was produced and evaluated in the same manner as in Example 13 except that the contact pressure (linear pressure) of the elastic regulating blade against the developer carrying member was 4 N / m. The obtained results are shown in Tables 3 and 4.

(Comparative Example 7)
In Example 14, a developing device was produced and evaluated in the same manner as in Example 14 except that the contact pressure (linear pressure) of the elastic regulating blade with respect to the developer carrying member was set to 25 N / m. The obtained results are shown in Tables 3 and 4.

1 is a schematic diagram illustrating an embodiment of a developing device of the present invention. It is a schematic diagram which shows the relationship between a roughness curve and a load curve (BAC). It is a figure for demonstrating how to obtain | require initial wear height Rpk.

Explanation of symbols

1 Photosensitive drum (image carrier)
2 Elasticity regulating blade (developer regulating member)
3 Hopper (developer container)
4 Developer 6 Metal cylindrical tube (base)
7 Conductive resin coating layer 8 Development sleeve (developer carrier)
9 Development bias power supply (bias means)
10 Stirring blade 11 Developer supply / peeling roller (Developer supply / peeling member)
A Development sleeve rotation direction B Photosensitive drum rotation direction D Development area

Claims (9)

A one-component developer is carried and conveyed on a rotating developer carrying member, and an elastic developer regulating member abutting on the developer carrying member via the developer is used for the loading of the carried developer. After regulating the layer thickness, the developer having the regulated layer thickness is transported to the development area facing the image carrier, and the electrostatic latent image carried on the image carrier is developed by the transported developer. In the developing device visualized by
The developer carrying member has at least a substrate and a conductive resin coating layer on the substrate surface, and the conductive resin coating layer has a 10-point average roughness Rzjis of 2.0 μm to 5.5 μm. , Rzjis has a coefficient of variation of 11% or less and an initial wear height Rpk of 0.80 μm or less,
The developing device according to claim 1, wherein the developer regulating member has a contact pressure (linear pressure) with respect to the developer carrying member of 5 N / m to 22 N / m.   The conductive resin coating layer contains at least a binder resin and graphitized particles dispersed in the binder resin, and the graphitized particles have a volume average particle size of 0.5 to 4.0 μm in a volume particle size distribution. 2. The developing device according to claim 1, wherein the proportion of the graphitized particles having a volume particle diameter of 10 μm or more is 5.0% by volume or less.   The developing device according to claim 1, wherein the graphitized particles have a graphitization degree P (002) of 0.20 or more and 0.95 or less.   4. The developing device according to claim 1, wherein the graphitized particles are obtained by graphitizing bulk mesophase pitch particles.   The developing device according to claim 1, wherein the graphitized particles are obtained by graphitizing mesocarbon microbead particles.   The developing device according to claim 1, wherein the developer regulating member has a ten-point average roughness Rzjis of a surface in contact with the developer carrying member of 1.0 μm or less. .   The developing device according to claim 1, wherein the developer regulating member includes a polyamide elastomer-containing rubber layer at a contact portion with the developer carrying member.   The developing device according to claim 1, wherein the one-component developer is a non-magnetic one-component developer.   The single-component developer has an average circularity of 0.970 or more in developer particles having an equivalent circle diameter of 3 μm or more and 400 μm or less as measured by a flow type particle image measuring apparatus for the developer particles. Item 9. The developing device according to any one of Items 1 to 8.

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