JP5578417B2 - Intermediate transfer belt and electrophotographic apparatus using the same - Google Patents

Description

  The present invention relates to a method of manufacturing a seamless belt provided in an image forming apparatus such as a copy printer, and an image forming apparatus using the same, and more particularly to an intermediate transfer belt suitable for full color image formation and an image forming apparatus using the same.

Conventionally, seamless belts have been used as members for various uses in electrophotographic apparatuses.
Particularly in recent full-color electrophotographic apparatuses, an intermediate transfer belt system in which developed images of four colors of yellow, magenta, cyan, and black are once overlaid on an intermediate transfer medium, and then collectively transferred to a transfer medium such as paper. Is used.
Such an intermediate transfer belt system has been used in a system that uses four color developing devices for one photoconductor, but has a drawback in that the printing speed is slow. For this reason, as a high-speed print, a four-tandem tandem method is used in which the photoreceptors are arranged for four colors and each color is continuously transferred to paper. However, in this method, there are fluctuations due to the environment of the paper, etc., and it is very difficult to match the position accuracy of overlapping each color image, causing a color misregistration image. Therefore, in recent years, it has become the mainstream to adopt the intermediate transfer method for the quadruple tandem method.

  Under such circumstances, the required characteristics (high-speed transfer, positional accuracy) of the intermediate transfer belt are also stricter than before, and it is necessary to satisfy the characteristics corresponding to these requirements. Yes. In particular, for positional accuracy, it is required to suppress fluctuations due to deformation such as elongation of the belt itself due to continuous use. Further, the intermediate transfer belt is laid out over a wide area of the apparatus, and is required to be flame retardant because a high voltage is applied for transfer. In order to meet such requirements, polyimide resins, polyamideimide resins, and the like that are high elastic modulus and high heat resistance resins are mainly used as intermediate transfer belt materials.

  However, since the intermediate transfer belt made of polyimide resin has high strength and high surface hardness, a high pressure is applied to the toner layer when the toner image is transferred, and the toner locally aggregates and a part of the image is formed. A so-called hollow image that is not transferred may occur. In addition, contact followability with a contact member at a transfer portion such as a photoconductor or paper is inferior, so that a partial contact failure portion (gap) may occur in the transfer portion, and transfer unevenness may occur.

In recent years, full-color electrophotography has been used to form images on various types of paper. In addition to ordinary smooth paper, recycled paper and embossed paper can be used not only from smooth paper but also from slippery and highly smooth paper such as coated paper. Roughly surfaced materials such as Japanese paper and kraft paper are increasingly used. Such followability to papers having different surface properties is important. If the followability is poor, uneven unevenness of color and uneven color tone occur.
In order to solve this problem, various intermediate transfer belts in which a relatively flexible layer is laminated on a base layer have been proposed.
However, when the surface layer is a relatively flexible layer, the transfer pressure is reduced and the followability to paper irregularities is improved, but the toner cannot be released well due to the poor surface releasability. There is a problem that transfer efficiency is lowered and the former effect cannot be utilized. There is also a problem that it is inferior in wear resistance and scratch resistance.

In order to solve this problem, there is a method of newly providing a protective layer, but when coated with a material having sufficiently high transfer performance, the flexibility of the flexible layer cannot be followed, and cracking or peeling occurs. There is not preferable.
On the other hand, proposals have been made to improve transferability by attaching fine particles to the surface.
JP-A-9-230717 of Patent Document 1 proposes coating with beads having a diameter of 3 μm or less.
However, the formation of this publication is not sufficient in terms of the durability required of recent electrophotographic apparatuses because particles are detached.
Japanese Patent Application Laid-Open No. 2002-162767 of Patent Document 2 and Japanese Patent Application Laid-Open No. 2004-354716 of Patent Document 3 propose forming a layer with a material having affinity for hydrophobized particles. In these, particles having a very small particle size are preferably used.
However, the particle layer is thick, or there are non-uniform portions due to particle aggregation, resulting in variations in transfer performance, and a product that can satisfy the high level of image quality required of recent electrophotographic devices can be obtained. Absent.
Japanese Patent Application Laid-Open No. 2007-328165 and Japanese Patent Application Laid-Open No. 2009-75154 of Patent Document 4 propose a configuration that realizes durability by using relatively large particles and embedding in resin to some extent. Yes. However, even in this proposal, non-uniformity occurs in the presence of particles, and it is impossible to obtain a product that can satisfy the high level of image quality required for recent electrophotographic apparatuses.
In all of Patent Documents 1 to 5, silica is preferably used. However, since silica particles have a strong cohesive force, a uniform particle layer cannot be formed as described above. In addition, inorganic particles such as silica tend to scratch and wear the surface of the organic photoreceptor due to contact with the organic photoreceptor that is preferably used as a latent image carrier for image formation, and reduce durability. This causes the problem of

The present invention has been made in view of the above prior art, is flexible, has excellent toner releasability, can achieve a high transfer rate regardless of the transfer medium, and is sustainable over a long period of time. An object of the present invention is to obtain an intermediate transfer belt for realizing a durable and high-quality electrophotographic apparatus.
Hereinafter, the “electrophotographic apparatus” may be referred to as an “image forming apparatus”.

As a result of intensive studies, the present inventors have determined that the surface of the intermediate transfer belt is formed of a resin layer in which uniform spherical shapes are formed by a single particle layer in which independent spherical resin particles are arranged in the plane direction. It was found that it can be realized.
That is, the said subject is solved by invention described in the following (1)-(10).
(1) “In an electrophotographic apparatus using an intermediate transfer belt, the surface of the intermediate transfer belt is formed by arranging individual spherical resin particles in a plane direction between each of a uniform convex portion and the convex portion. And the fine particle layer region contains fine particles having a smaller particle size and different material than the resin particles, and the intermediate transfer belt surface has a thermosetting elastomer or rubber material. The spherical resin particles are formed in the depth direction of the resin layer before heat curing of the resin layer containing the heat-curable elastomer or rubber material. An intermediate transfer belt characterized by being embedded at a burial rate exceeding 50% and less than 100%, and then being fixed to the resin layer by heat-curing ",
(2) “Intermediate transfer belt according to item (1), wherein the surface of the intermediate transfer belt further contains a lubricant”,
(3) “Intermediate transfer belt according to item (2), wherein the lubricant is zinc stearate”;
(4) "Intermediate transfer belt according to any one of (1) to (3) above, wherein the spherical resin particles are silicone resin fine particles",
(5) "Intermediate transfer belt according to any one of items (1) to (4), wherein the fine particles are fine particles of calcium carbonate",
(6) “The spherical resin particles are monodisperse particles having an average particle diameter of 0.5 μm to 5.0 μm, and any one of the items (1) to (5),” Intermediate transfer belt ",
(7) “Intermediate transfer belt according to any one of (1) to (6) above, wherein the 60 ° glossiness of the surface of the intermediate transfer belt is 20 or more”,
(8) "Electrophotographic apparatus comprising the intermediate transfer belt according to any one of (1) to (7)",
(9) "The electrophotographic apparatus according to item (8) above, wherein the electrophotographic apparatus having an intermediate transfer belt has a mechanism for applying a lubricant to the surface of the intermediate transfer belt".
(10) “In the intermediate transfer belt manufacturing method, the intermediate transfer belt has a uniform convex shape in which the surface of the intermediate transfer belt contains a lubricant and at least independent spherical resin particles are arranged in the surface direction. And a fine particle layer region existing between the convex portion, the fine particle layer region includes fine particles of a smaller particle size and different material than the resin particles, and the intermediate transfer belt surface is heat curable. The spherical resin particles are embedded at a burial rate of more than 50% and less than 100% in the depth direction of the resin layer. a least, the step of forming a uniform particle layer by arranging and embedding step of uniformly dry coated spherical shaped resin particles in the resin layer of the intermediate transfer belt, the leveling process, the resin Step of heat curing and then, the production method of the intermediate transfer belt, characterized in that it comprises the step of the fine particles dry coating, the step of homogenizing the particles, a step of dry-coated with a lubricant, a step of equalizing the lubricant "

  According to the present invention, it is possible to provide a highly durable and high-quality electrophotographic apparatus capable of maintaining high transfer performance not only initially but also for a long period of time regardless of the type and surface properties of the transfer medium. it can.

FIG. 3 is a schematic diagram illustrating a layer configuration example of an intermediate transfer belt in the present invention. The schematic diagram of the cross-sectional form of the surface layer of the intermediate transfer belt in this invention is shown. The schematic diagram of the apparatus for apply | coating and fixing the powder particle in this invention is shown. It is a principal part schematic diagram for demonstrating the image forming apparatus equipped with the seamless belt obtained by the manufacturing method which concerns on this invention as a belt member. FIG. 3 is a schematic diagram of a main part showing an example of a configuration of an image forming apparatus in which a plurality of photosensitive drums are arranged in parallel along one intermediate transfer belt formed of a seamless belt according to the present invention. FIG. 2 shows a schematic diagram of a cross section of an intermediate transfer belt having a surface layer containing a plurality of particles.

The intermediate transfer belt of the present invention has a sea-island structure in which each surface has a uniform convex portion in a concave region, and the concave region is basically formed by a fine particle layer. . Sea areas that may be substantially flat are referred to herein as concave areas because each is relatively concave compared to a uniform convex portion.
That is, as described above, in the intermediate transfer belt according to the present invention, the surface of the intermediate transfer belt has at least independent spherical resin particles arranged in the surface direction, and each has a uniform convex portion and the convex portion. The fine particle layer region includes fine particles of a smaller particle size and different material than the resin particles.
The intermediate transfer belt of the present invention will be described below.

The intermediate transfer belt of the present invention is an intermediate transfer belt type electrophotographic apparatus [so-called a plurality of color toner developed images sequentially formed on an image carrier (for example, a photosensitive drum) are sequentially superimposed on the intermediate transfer belt. Thus, the apparatus is suitably equipped as an intermediate transfer belt in an apparatus that performs primary transfer and batch-transfers the primary transfer image onto a recording medium. The intermediate transfer belt can typically be a seamless belt, but is not necessarily limited thereto.
FIG. 1 shows a layer structure of an intermediate transfer belt preferably used in the present invention.
However, it is not limited to this configuration.
As a constitution, a flexible resin layer (12) filled with fine particles is laminated on a rigid base layer (11) capable of obtaining relatively flexibility, and the resin layer (fine particle region) (12) On the outermost surface, preferably, a convex array portion (13) of spherical resin particles partially embedded in a resin layer (12) provided with a lubricant layer (14) is formed in layers. .

First, the base layer (11) will be described.
Examples of the constituent material include a material containing a filler (or additive) for adjusting electric resistance in the resin, that is, a so-called electric resistance adjusting material.
As such a resin, from the viewpoint of flame retardancy, for example, a fluorine-based resin such as PVDF, ETFE, a polyimide resin or a polyamide-imide resin is preferable, and particularly from the viewpoint of mechanical strength (high elasticity) and heat resistance. A polyimide resin or a polyamideimide resin is preferred.

Examples of the electrical resistance adjusting material include a metal oxide, carbon black, an ionic conductive agent, and a conductive polymer material.
Examples of the metal oxide include zinc oxide, tin oxide, titanium oxide, zirconium oxide, aluminum oxide, and silicon oxide. In addition, in order to improve dispersibility, the metal oxide may be subjected to surface treatment in advance.
Examples of carbon black include ketjen black, furnace black, acetylene black, thermal black, and gas black.
Examples of the ionic conductive agent include tetraalkylammonium salts, trialkylbenzylammonium salts, alkylsulfonates, alkylbenzenesulfonates, alkyl sulfates, glycerol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acids. Alcohol ester, alkyl betaine, lithium perchlorate, etc. are mentioned, and these may be used in combination.
The electrical resistance adjusting material in the present invention is not limited to the above exemplary compounds.
In addition, the coating liquid containing at least the resin component in the method for producing the intermediate transfer belt of the present invention may further include additives such as a dispersion aid, a reinforcing material, a lubricant, a heat conduction material, and an antioxidant as necessary. You may contain.

The electric resistance adjusting material contained in the belt substrate suitably equipped as the intermediate transfer belt is preferably 1 × 10 ⁸ to 1 × 10 ¹³ Ω / □ in surface resistance and 1 × 10 ⁶ to 1 in volume resistance. The amount is set to × 10 ¹² Ω · cm, but it is necessary to select and add an amount in a range where the molded film is brittle and does not easily break from the viewpoint of mechanical strength.
In other words, in the case of an intermediate transfer belt, an electrical characteristic (for example, a coating liquid in which the blending of the resin component (for example, a polyimide resin precursor or a polyamideimide resin precursor) and an electrical resistance adjusting material is appropriately adjusted is used. It is preferable to manufacture and use a seamless belt having a balance between surface resistance and volume resistance) and mechanical strength.

  In the case of carbon black, the content of the electric resistance adjusting material in the present invention is 10 to 25 wt%, preferably 15 to 20 wt% of the total solid content in the coating liquid. Moreover, as content in the case of a metal oxide, it is 1-50 wt% of the total solid of a coating liquid, Preferably it is 10-30 wt%. If the content is less than the range of the respective electric resistance adjusting materials, the effect cannot be sufficiently obtained, and if the content is greater than the respective range, the mechanical strength of the intermediate transfer belt (seamless belt) decreases. This is not preferable for practical use.

Next, the resin layer (layer serving as a basis for forming the fine particle region) (12) laminated on the base layer (11) will be described.
As a constituent material, materials such as general-purpose resins, elastomers, and rubbers can be used. However, it is preferable to use a material having sufficient flexibility (elasticity) to sufficiently express the effects of the present invention. It is preferable to use an elastomer material or a rubber material.
Examples of the elastomer material include thermoplastic elastomers such as polyester, polyamide, polyether, polyurethane, polyolefin, polystyrene, polyacryl, polydiene, silicone-modified polycarbonate, and fluorine copolymer. . Examples of thermosetting include polyurethane, silicone-modified epoxy, and silicone-modified acrylic.
Examples of the rubber material include isoprene rubber, styrene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, butyl rubber, silicone rubber, chloroprene rubber, acrylic rubber, chlorosulfonated polyethylene, fluorine rubber, urethane rubber, and hydrin rubber. .
A material capable of obtaining performance is appropriately selected from the various elastomers and rubbers.
In particular, it is preferable to select a soft material as much as possible in order to follow the surface state of a paper such as a resack paper having irregularities in the surface properties of the paper as a transfer material.
In the present invention, in order to form a spherical resin particle layer on the surface of this material, a thermosetting material is preferable to a thermoplastic material. The thermosetting material is excellent in adhesiveness with the resin particles due to the effect of the functional group contributing to the curing reaction, and can be reliably fixed.
Vulcanized rubber is likewise preferred.

  To the selected material, a resistance adjusting agent for adjusting electrical characteristics, a flame retardant for obtaining flame retardancy, and materials such as an antioxidant, a reinforcing agent, a filler, and a vulcanization accelerator as necessary. Mixing appropriately included.

As the resistance adjuster for adjusting the electrical characteristics, the above-mentioned various materials can be applied. However, since carbon black, metal oxide, and the like impair flexibility, it is preferable to suppress the use amount, and the ionic conductive agent and the conductive agent are used. It is also effective to use a functional polymer. Moreover, you may use these together.
The resistance value of the resin layer is preferably adjusted so that the surface resistance is 1 × 10 ⁸ to 1 × 10 ¹³ Ω / □ and the volume resistance is 1 × 10 ⁶ to 1 × 10 ¹² Ω · cm. .
The thickness of the resin layer is preferably about 200 μm to 2 mm. If the film thickness is thin, the followability to the surface properties of the transfer medium and the effect of reducing the transfer pressure are low, which is not preferable. If it is too thick, the film becomes heavier and more likely to bend, resulting in instability in running performance, and because cracks are likely to occur due to bending at the roller curvature portion for stretching the belt, such being undesirable.

Next, the spherical resin particles formed on the surface of the resin layer will be described.
The material is not particularly limited, and examples thereof include spherical particles mainly composed of resins such as acrylic resin, melamine resin, polyamide resin, polyester resin, silicone resin, and fluororesin. Further, the surface of particles made of these resin materials may be subjected to a surface treatment with a different material.
Further, the resin particles referred to here include a rubber material. A structure in which the surface of spherical particles made of a rubber material is coated with a hard resin is also applicable.
Moreover, it may be hollow or porous.
Among these resins, silicone resin particles are most preferred as those having a slipperiness and a high function capable of imparting releasability to toner and abrasion resistance.
It is preferable that the resin is a particle formed into a spherical shape by a polymerization method or the like using these resins.
Moreover, as for the particle size, a volume average particle size is 0.5 micrometer-5.0 micrometers, and it is desirable that it is monodisperse with a sharp distribution. When the particle size is 0.5 μm or less, the effect of transfer performance due to the particles cannot be sufficiently obtained. On the other hand, when the particle size is 5.0 μm or more, the surface roughness increases and the gap between the particles increases, so that the toner works well. Problems such as inability to transfer or defective cleaning occur.
Furthermore, since the particles are often insulative, if the particle size is too large, a residual charging potential due to the particles causes a problem that image disturbance occurs due to accumulation of this potential during continuous image output.
Such monodispersed spherical resin particles can be easily and uniformly aligned by directly applying the powder directly onto the resin layer and smoothing.

By forming the spherical resin particles, it is possible to achieve high toner transfer performance even with a rough surface property of the transfer material to some extent, but this is not sufficient for paper with large irregularities. Specifically, for a paper such as Lessac paper having a continuous amount of 175 kg or more, where the peak height of the unevenness is 100 μm or more, the resin layer extends due to deformation when following the unevenness depth, and the particles The interval is widened and the resin layer is exposed.
When the space between the particles spreads, the toner comes into contact with the resin layer between the particles, which causes a decrease in transfer performance.
In addition, since the surface on which the spherical resin particle layer is formed is a minute uneven surface, there is a problem in that it tends to be a blurred image on a smooth paper such as coated paper having no unevenness. .

Therefore, in the present invention, the spherical resin particles are formed in a state where the spherical resin particles are arranged on the resin layer, so that gaps between the particles that can be formed into the spherical resin particle layer can be obtained by including fine particles having a particle diameter smaller than that of the spherical resin particles. Filling and surface smoothness can be improved, and a good image can be transferred to paper with deep irregularities and paper with high smoothness.
Further, by including a lubricant in combination with the fine particles, further excellent transfer can be realized.
The fine particles and the lubricant are applied after fixing the spherical resin particles to the resin layer.
It is not preferable to apply the spherical resin particles, the fine particles, and the lubricant at the same time, because the arrangement of the spherical resin particles becomes non-uniform and immobilization is inhibited.
The fine particles may be indefinite or spherical as long as they are smaller than the spherical resin particles. In addition, any of organic and inorganic materials can be used.
As the organic material, the aforementioned general resin or rubber fine particles can be used.
Examples of inorganic substances include silica, calcium carbonate, magnesium carbonate, mica, kaolin, aluminum hydroxide, magnesium hydroxide, metal oxides such as titanium oxide, aluminum oxide, and zinc oxide, carbon black, and carbon nanotubes.
Moreover, what surface-treated the surface of these various particles can also be applied.
A mixture of these may also be used.
However, if fine particles harder than the spherical resin particles used earlier are used, care must be taken because the spherical resin particles are easily dropped in the step of attaching the fine particles.
More preferably, it is preferable to select a material that is soft enough not to drop the spherical resin particles.

In addition, fluororesin fine particles and molybdenum disulfide such as those having lubricating performance can also be used.
Of the various particles described above, white powder is preferable from the viewpoint of adhesion to a transfer material and color mixing, and calcium carbonate is preferable from the viewpoint of compatibility with the underlying rubber and safety.
By applying and leveling the fine particles to the surface of the spherical resin particles, the gaps between the spherical resin particles can be filled with the fine particles.
The lubricant can be applied by mixing with the fine particles. In addition, after applying the fine particles, a lubricant may be applied and uniformed thereon. Furthermore, it is more preferable in terms of transfer performance and durability to repeat this step.
The lubricant may be in any form such as oil, wax, powder, etc., but preferably selected in consideration of the releasability of the toner, and a long chain fatty acid metal salt is preferred. In particular, zinc stearate is suitable.
In the application of a long chain aliphatic metal salt such as zinc stearate, it is possible to apply it by a wet method. The coating is preferably performed by directly coating or rubbing a solid molded product. In particular, it is preferable to apply the fine powder to fill the gaps between the spherical resin fine particles. After coating in powder form, excess material is removed by smoothing. At this time, zinc stearate is formed into a thin film by heating at a specified pressure and as necessary, and firmly fixed. can do. Thereby, the smoothness of the surface is further improved, and the glossiness of the surface is also improved.
When the glossiness increases, position control by a sensor using reflected light on the belt surface becomes possible, which is effective for models that require high accuracy.

Next, FIG. 2 shows an enlarged schematic sectional view of the belt surface.
In the belt of the present invention, as described above, the outermost surface of the intermediate transfer belt is composed of a region having a uniform convex shape with independent spherical resin particles arranged in the surface direction, and a region having a convex shape of the spherical resin particle. It is composed of a concave region of the lubricant layer in between, and the preferred area ratio between the particle convex portion and the concave region is preferably 60 to 90% as the projected sectional area of the particles. This projected cross-sectional area is obtained by photographing the surface at a magnification which is an electron microscope and calculating the area ratio between the particle image portion and the other portion from the photographed image using image processing software.
The image magnification at this time is determined as appropriate depending on the size of the particle and the like, and is the magnification when the number of particles included in the field of view is about 100 to 300.
In the present invention, the spherical resin particles are preferably embedded in the resin, and the burying rate is preferably more than 50% and less than 100%. If it is 50% or less, particle detachment tends to occur during long-term use in an electrophotographic apparatus, resulting in poor durability. On the other hand, 100% is not preferable because the effect of the particles on the transferability is reduced.
The adjustment of the burying rate of the particles in the resin layer may be possible by other methods, but can be easily achieved by, for example, adjusting the pressing force of the pressing member (43). For example, when the pressing force is in the range of 1 mN / cm to 1000 mN / cm, the above-mentioned 50% <burial ratio <100% can be achieved relatively easily.
The burial rate is measured by observing the cross section of the belt with an electron beam microscope.
Furthermore, this particle layer is preferably formed as a single layer in the thickness direction with respect to the resin layer.
As shown in FIG. 6, in the configuration including a plurality of particles in the thickness direction, the distribution of the particles becomes uneven, and the electric characteristics of the belt surface become uneven due to the influence of the electric resistance value of the particles. Disturbs. Specifically, the electrical resistance value in the portion where many particles are present becomes high, a surface potential is generated due to the residual charge, and the surface potential varies on the belt surface, resulting in the image density in the adjacent portion. Image disturbance due to a difference or the like becomes obvious.

Next, an example of a method for producing the belt having the configuration of the present invention will be described.
First, a method for manufacturing the base layer will be described.

A method for producing a base layer using the coating liquid containing at least the resin component of the present invention, that is, the coating liquid containing the polyimide resin precursor or the polyamideimide resin precursor will be described.
While slowly rotating a cylindrical mold, for example, a cylindrical metal mold, a coating liquid containing at least a resin component (for example, a coating liquid containing a polyimide resin precursor or a polyamideimide resin precursor) is used as a nozzle or Application and casting (formation of a coating film) is performed uniformly on the entire outer surface of the cylinder by a liquid supply device such as a dispenser. Thereafter, the rotation speed is increased to a predetermined speed, and when the predetermined speed is reached, the rotation speed is maintained at a constant speed and the rotation is continued for a desired time. And the solvent in a coating film is evaporated at the temperature of about 80-150 degreeC, heating up gradually while rotating. In this process, it is preferable to efficiently circulate and remove atmospheric vapor (such as a volatilized solvent). When a self-supporting film is formed, the mold is transferred to a heating furnace (firing furnace) capable of high-temperature processing, and the temperature is raised stepwise, and finally high-temperature heat processing (firing is performed at about 250 ° C. to 450 ° C. Then, the polyimide resin precursor or the polyamideimide resin precursor is fully imidized or polyamideimided.
After sufficiently cooling, a resin layer is subsequently laminated.
The resin layer can be formed on the base layer by injection molding, extrusion molding, or the like. Here, a method of coating and forming on the base layer using a thermosetting liquid elastomer material will be described. The coating liquid containing at least a liquid thermosetting elastomer material is made uniform over the entire outer surface of the cylinder by a liquid supply device such as a nozzle or dispenser while slowly rotating the cylindrical metal mold like the base layer. Apply and cast (form a coating film).
Thereafter, the rotation speed is increased to a predetermined speed, and when the predetermined speed is reached at a desired time, the rotation speed is maintained at a constant speed and the rotation is continued. Then, when sufficiently leveled, as shown in FIG. 3, a powder coating device (35) and a pressing member (33) are installed, and spherical particles are uniformly applied to the surface from the powder coating device (35) while rotating. The spherical particles applied to the surface are pressed with a pressing member (33) at a constant pressure. The pressing member (33) removes excess particles while embedding particles in the resin layer. In the present invention, in particular, since monodispersed spherical particles are used, it is possible to form a uniform single particle layer by a simple process of only the leveling process using such a pressing member.
After the formation of a uniform particle layer, the resin layer is cured by heating at a predetermined temperature and a predetermined time while rotating to form a resin layer.

Next, fine particles finer than the spherical resin particles and a lubricant are applied and uniformed using the apparatus of FIG. 3 as described above. Although the spherical resin particles are applied only once, it is preferable to repeat application and leveling here. The fine particles and the lubricant may be applied separately.
By performing this step, the space between the spherical resin particles is filled with fine particles and a lubricant.
After that, more preferably, the lubricant is fixed firmly by applying only the lubricant at the end and repeating it while pressing it slightly stronger.
In particular, when zinc stearate is used as a lubricant, if it is repeatedly strongly pressed while slightly warming as necessary, the lubricant becomes an adhesive between the zinc stearate and fine particles such as calcium carbonate having a high affinity. By acting as described above, the fine particles can be firmly bonded to each other.
Furthermore, on the outermost surface, a thin film with zinc stearate can be formed.
On the surface of the spherical resin particle layer, the surface of the belt is a matte surface. However, as described above, the surface becomes smooth by the action of the fine particles and the lubricant.
Specifically, the surface gloss by the 60-degree gloss meter is almost 0 on the surface of the spherical resin particle layer, whereas the configuration of the present invention can achieve a gloss of 30 or more.
As a result, in an electrophotographic apparatus, it becomes possible to use an optical sensor for controlling position control, toner image adhesion amount, and the like using the surface reflected light of the intermediate transfer belt, and applying more advanced device control. Is possible.
Thereafter, the entire base layer is detached from the mold to obtain a desired seamless belt (intermediate transfer belt).

For example, the seamless belt manufactured by the above-described method performs primary transfer by sequentially superimposing a plurality of color toner developed images sequentially formed on an image carrier on an intermediate transfer belt, and the primary transfer image is recorded. It can be suitably used as an intermediate transfer belt of a so-called intermediate transfer type electrophotographic apparatus in which secondary transfer is collectively performed on a medium, and can form an electrophotographic apparatus (image forming apparatus) capable of forming a high-quality image.
A seamless belt used in a belt constituting unit provided in an electrophotographic apparatus (hereinafter referred to as “image forming apparatus”) in the present invention will be described in detail below with reference to a schematic diagram of a main part. The schematic diagram is an example, and the present invention is not limited to this.
FIG. 4 is a schematic diagram of a main part for explaining an image forming apparatus equipped with a seamless belt obtained by the manufacturing method according to the present invention as a belt member.
The intermediate transfer unit (500) including the belt member shown in FIG. 4 includes an intermediate transfer belt (501) that is an intermediate transfer member stretched around a plurality of rollers. Around the intermediate transfer belt (501), there are a secondary transfer bias roller (605) as a secondary transfer charge applying means of the secondary transfer unit (600), and a belt cleaning blade (504) as an intermediate transfer body cleaning means. A lubricant application brush (505), which is a lubricant application member of the lubricant application means, is disposed so as to face each other.

  Further, position detection marks (not shown) are provided on the outer peripheral surface or inner peripheral surface of the intermediate transfer belt (501). However, on the outer peripheral surface side of the intermediate transfer belt (501), it is necessary to devise a position detection mark that avoids the passing area of the belt cleaning blade (504), which may be difficult to arrange. In this case, a position detection mark may be provided on the inner peripheral surface side of the intermediate transfer belt (501). The optical sensor (514) serving as a mark detection sensor is provided at a position between the primary transfer bias roller (507) and the belt driving roller (508) on which the intermediate transfer belt (501) is stretched.

  The intermediate transfer belt (501) includes a primary transfer bias roller (507), a belt driving roller (508), a belt tension roller (509), a secondary transfer counter roller (510), which are primary transfer charge applying means, and a cleaning device. It is stretched between the counter roller (511) and the feedback current detection roller (512). Each roller is made of a conductive material, and each roller other than the primary transfer bias roller (507) is grounded. The primary transfer bias roller (507) is controlled by a primary transfer power source (801) controlled by a constant current or a constant voltage so that the current or voltage is controlled to a predetermined magnitude according to the number of superimposed toner images. A bias is applied.

The intermediate transfer belt (501) is driven in the direction of the arrow by a belt drive roller (508) that is driven to rotate in the direction of the arrow by a drive motor (not shown).
The intermediate transfer belt (501) as the belt member is usually a semiconductor or an insulator and has a single-layer or multi-layer structure, but in the present invention, a seamless belt is preferably used, thereby improving durability. In addition, excellent image formation can be realized. In addition, the intermediate transfer belt is set to be larger than the maximum sheet passing size in order to superimpose the toner images formed on the photosensitive drum (200).

  A secondary transfer bias roller (605), which is a secondary transfer means, is in contact with / separating means, which will be described later, with respect to the belt outer peripheral surface of a portion of the intermediate transfer belt (501) stretched around the secondary transfer counter roller (510) It is comprised so that contact / separation is possible by the contact / separation mechanism. The secondary transfer bias roller (605) sandwiches the transfer paper (P) as a recording medium between the secondary transfer counter roller (510) and the intermediate transfer belt (501) stretched between the secondary transfer counter roller (510). A transfer bias having a predetermined current is applied by a secondary transfer power source (802) that is arranged and controlled at a constant current.

  The registration roller (610) is a transfer sheet as a transfer material at a predetermined timing between the secondary transfer bias roller (605) and the intermediate transfer belt (501) stretched around the secondary transfer counter roller (510). Send (P). Further, a cleaning blade (608) as a cleaning unit is in contact with the secondary transfer bias roller (605). The cleaning blade (608) removes and removes adhering material adhering to the surface of the secondary transfer bias roller (605).

  In the color copying machine having such a configuration, when the image forming cycle is started, the photosensitive drum (200) is rotated in a counterclockwise direction indicated by an arrow by a driving motor (not shown), and the photosensitive drum (200) In addition, Bk (black) toner image formation, C (cyan) toner image formation, M (magenta) toner image formation, and Y (yellow) toner image formation are performed. The intermediate transfer belt (501) is rotated clockwise by the belt driving roller (508) as indicated by an arrow. As the intermediate transfer belt (501) rotates, the primary transfer of the Bk toner image, the C toner image, the M toner image, and the Y toner image is performed by the transfer bias by the voltage applied to the primary transfer bias roller (507). Finally, toner images are formed on the intermediate transfer belt (501) in the order of Bk, C, M, and Y.

For example, the Bk toner image formation is performed as follows.
In FIG. 4, a charging charger (203) uniformly charges the surface of the photosensitive drum (200) to a predetermined potential with a negative charge by corona discharge. The timing is determined based on the belt mark detection signal, and raster exposure with laser light is performed based on the Bk color image signal by a writing optical unit (not shown). When this raster image is exposed, the charge proportional to the exposure light amount disappears in the exposed portion of the surface of the photosensitive drum (200) that is initially charged uniformly, and a Bk electrostatic latent image is formed. When the negatively charged Bk toner on the developing roller of the Bk developing device (231K) comes into contact with this Bk electrostatic latent image, the toner adheres to the portion where the charge of the photosensitive drum (200) remains. In other words, toner is attracted to a portion having no charge, that is, an exposed portion, and a Bk toner image similar to the electrostatic latent image is formed.

  The Bk toner image formed on the photosensitive drum (200) in this way is primary on the belt outer peripheral surface of the intermediate transfer belt (501) rotating at a constant speed while being in contact with the photosensitive drum (200). Transcribed. Some untransferred residual toner remaining on the surface of the photoreceptor drum (200) after the primary transfer is cleaned by the photoreceptor cleaning device (201) in preparation for reuse of the photoreceptor drum (200). Is done. On the photosensitive drum (200) side, the process proceeds to the C image forming process after the Bk image forming process, and reading of the C image data by the color scanner starts at a predetermined timing. A C electrostatic latent image is formed on the surface of the body drum (200).

  Then, after the rear end portion of the previous Bk electrostatic latent image passes and before the front end portion of the C electrostatic latent image reaches, the revolver developing unit (230) is rotated, and the C developing machine (231) C is set at the development position, and the C electrostatic latent image is developed with C toner. Thereafter, development of the C electrostatic latent image area is continued, but when the rear end portion of the C electrostatic latent image passes, the revolver developing unit is rotated as in the case of the previous Bk developing machine (231K). Then, the next M developing machine (231M) is moved to the developing position. This is also completed before the leading edge of the next Y electrostatic latent image reaches the developing position. Note that the M and Y image forming steps are the same as the Bk and C steps described above because the operations of reading color image data, forming an electrostatic latent image, and developing are the same as those described above.

The Bk, C, M, and Y toner images sequentially formed on the photosensitive drum (200) in this manner are sequentially aligned on the same surface on the intermediate transfer belt (501) and primarily transferred. As a result, a toner image having a maximum of four colors superimposed on the intermediate transfer belt (501) is formed. On the other hand, at the time when the image forming operation is started, the transfer paper (P) is fed from a paper feed unit such as a transfer paper cassette or a manual feed tray, and is waiting at the nip of the registration roller (610).
Then, on the intermediate transfer belt (501), the intermediate transfer belt (501) stretched around the secondary transfer counter roller (510) and the secondary transfer bias roller (605) form a nip. When the leading edge of the toner image approaches, the registration roller (610) is driven so that the leading edge of the transfer paper (P) coincides with the leading edge of the toner image, and is transferred along the transfer paper guide plate (601). The paper (P) is conveyed and registration of the transfer paper (P) and the toner image is performed.

  In this way, when the transfer paper (P) passes through the secondary transfer portion, the intermediate transfer belt (501) is transferred by the transfer bias generated by the voltage applied to the secondary transfer bias roller (605) by the secondary transfer power source (802). ) The four-color superimposed toner image on the top is transferred onto the transfer paper (P) at once (secondary transfer). This transfer paper (P) is conveyed along the transfer paper guide plate (601) and passes through a portion facing the transfer paper neutralization charger (606) comprising a static elimination needle disposed downstream of the secondary transfer portion. After being neutralized by this, the belt is conveyed toward the fixing device (270) by the belt conveying device (210) which is a belt component (see FIG. 1). Then, after the toner image is melted and fixed at the nip portion of the fixing rollers (271) and (272) of the fixing device (270), the transfer paper (P) is sent out of the apparatus main body by a discharge roller (not shown). Stacked face up on a copy tray (not shown). Note that the fixing device (270) may be configured to include a belt component if necessary.

  On the other hand, the surface of the photosensitive drum (200) after the belt transfer is cleaned by the photosensitive member cleaning device (201) and is uniformly discharged by the discharging lamp (202). The residual toner remaining on the outer peripheral surface of the intermediate transfer belt (501) after the toner image is secondarily transferred to the transfer paper (P) is cleaned by the belt cleaning blade (504). The belt cleaning blade (504) is configured to contact and separate at a predetermined timing with respect to the belt outer peripheral surface of the intermediate transfer belt (501) by a cleaning member separating and contacting mechanism (not shown).

  On the upstream side of the belt cleaning blade (504) in the moving direction of the intermediate transfer belt (501), a toner seal member (502) contacting and separating from the belt outer peripheral surface of the intermediate transfer belt (501) is provided. Yes. The toner seal member (502) receives the falling toner that has dropped from the belt cleaning blade (504) during cleaning of the residual toner, and prevents the falling toner from scattering on the transfer path of the transfer paper (P). It is preventing. The toner seal member (502) is brought into contact with and separated from the belt outer peripheral surface of the intermediate transfer belt (501) together with the belt cleaning blade (504) by the cleaning member separating and contacting mechanism.

The lubricant (506) scraped by the lubricant application brush (505) is applied to the belt outer peripheral surface of the intermediate transfer belt (501) from which the residual toner has been removed in this way. The lubricant (506) is made of, for example, a solid body such as zinc stearate, and is disposed so as to come into contact with the lubricant application brush (505). Further, residual charges remaining on the outer peripheral surface of the intermediate transfer belt (501) are removed by a neutralizing bias applied by a belt neutralizing brush (not shown) in contact with the outer peripheral surface of the intermediate transfer belt (501).
Here, the lubricant application brush (505) and the belt neutralizing brush are brought into and out of contact with the outer peripheral surface of the intermediate transfer belt (501) at a predetermined timing by a contact / separation mechanism (not shown). It has become.

  Here, in the case of repeat copy, the operation of the color scanner and the image formation on the photosensitive drum (200) are performed at a predetermined timing following the image formation process for the fourth color (Y) of the first sheet. The process proceeds to the image forming process for the first color (Bk). The intermediate transfer belt (501) has two sheets in the area cleaned by the belt cleaning blade (504) on the outer peripheral surface of the belt following the batch transfer process of the first four-color superimposed toner image to the transfer paper. The Bk toner image of the eye is primarily transferred. After that, the operation is the same as the first sheet. The above is a copy mode for obtaining a four-color full-color copy. In the three-color copy mode and the two-color copy mode, the same operation as described above is performed for the designated color and number of times. In the case of the single color copy mode, only the developing device of the predetermined color of the revolver developing unit (230) is set in the developing operation state until the predetermined number of sheets is completed, and the belt cleaning blade (504) is moved to the intermediate transfer belt (501). The copy operation is performed with the touch panel kept in contact.

In the above-described embodiment, the copying machine having only one photosensitive drum has been described. However, the present invention can seamlessly include a plurality of photosensitive drums as shown in an exemplary configuration in a schematic diagram of a main part in FIG. The present invention can also be applied to an image forming apparatus arranged side by side along one intermediate transfer belt made of a belt.
FIG. 5 shows four drums including four photosensitive drums (21BK), (21Y), (21M), and (21C) for forming toner images of four different colors (black, yellow, magenta, and cyan). 1 shows an example of the configuration of a type digital color printer.

  In FIG. 5, the printer main body (10) includes an image writing unit (12), an image forming unit (13), and a paper feeding unit (14) for forming a color image by electrophotography. Based on the image signal, the image processing unit converts the image into black (BK), magenta (M), yellow (Y), and cyan (C) color signals for image formation, and the image writing unit (12). Send to. The image writing unit (12) is a laser scanning optical system including, for example, a laser light source, a deflector such as a rotary polygon mirror, a scanning imaging optical system, and a mirror group, and corresponds to each color signal described above. There are four writing optical paths, and image carriers (photoconductors) (21BK), (21M), (21Y), and (21C) provided for each color of the image forming unit (13) according to the respective color signals. Perform image writing.

The image forming unit (13) is a photoconductor (21BK), (21M), (21Y) which is an image carrier for black (BK), magenta (M), yellow (Y), and cyan (C). ), (21C).
As each photoconductor for each color, an OPC photoconductor is usually used. Around each photosensitive member (21BK), (21M), (21Y), (21C), there is a charging device, an exposure unit for laser light from the writing unit 12, and black, magenta, yellow, and cyan colors. Developing devices (20BK), (20M), (20Y), (20C), primary transfer bias rollers (23BK), (23M), (23Y), (23C) as primary transfer means, and cleaning devices (not shown) ), And a photosensitive member static elimination device (not shown). The developing devices (20BK), (20M), (20Y), and (20C) use a two-component magnetic brush developing system. The intermediate transfer belt (22), which is a belt component, includes the photosensitive members (21BK), (21M), (21Y), and (21C) and the primary transfer bias rollers (23BK), (23M), and (23Y). , (23C), and the toner images of the respective colors formed on the respective photoreceptors are sequentially superimposed and transferred.

  On the other hand, the transfer paper (P) is fed from the paper feeding section (14) and then carried on the transfer conveyance belt (50), which is a belt constituting section, via the registration rollers (16). When the intermediate transfer belt (22) and the transfer conveying belt (50) come into contact with each other, the toner image transferred onto the intermediate transfer belt (22) is transferred to a secondary transfer bias roller (60) as a secondary transfer unit. ) For secondary transfer (collective transfer). Thereby, a color image is formed on the transfer paper (P). The transfer paper (P) on which the color image is formed is conveyed to the fixing device (15) by the transfer conveying belt (50). After the image transferred by the fixing device (15) is fixed, the transfer paper (P) is removed from the printer main body. To be discharged.

Residual toner remaining on the intermediate transfer belt (22) without being transferred during the secondary transfer is removed from the intermediate transfer belt (22) by the belt cleaning member (25).
A lubricant application device (27) is disposed downstream of the belt cleaning member (25). The lubricant application device (27) includes a solid lubricant and a conductive brush that rubs the intermediate transfer belt (22) to apply the solid lubricant. The conductive brush is always in contact with the intermediate transfer belt (22) and applies a solid lubricant to the intermediate transfer belt (22). The solid lubricant has an effect of improving the cleaning property of the intermediate transfer belt (22), preventing the occurrence of filming and improving the durability.
In the lubricant application apparatus in the apparatus shown in FIGS. 4 and 5, the same type of lubricant used in the intermediate transfer belt is used to replenish a lubricant component that can be removed by wear or the like in long-term use. The fine particles also contain calcium carbonate, which is a component contained in the paper that is the transfer material, and the amount removed by contact with the paper in the transfer region is appropriately attached to the belt, and the lubricant application device Therefore, the initial state can always be maintained together with the lubricant, and the performance can be maintained permanently.

  EXAMPLES Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited by these examples, and these examples are appropriately modified without departing from the gist of the present invention. Is also within the scope of the present invention.

A base layer coating solution was prepared as follows, and a seamless belt base layer was produced using this coating solution.
<Preparation of base layer coating solution>
First, carbon black (Special Black 4; Evonik Degussa Co., Ltd.) dispersed in N-methyl-2-pyrrolidone with a bead mill in advance in a polyimide varnish (U-varnish A; Ube Industries, Ltd.) containing a polyimide resin precursor as a main component. (Manufactured) was prepared so that the carbon black content was 17% by weight of the polyamic acid solid content, and well stirred and mixed to prepare a coating solution.

[Manufacture of seamless belts]
Next, a metal cylinder having an outer diameter of 320 mm and a length of 360 mm roughened by blasting is used as a mold, and the cylinder layer is rotated at 50 rpm (times / minute) while the base layer coating liquid is used. Was applied by a dispenser so as to be uniformly cast on the outer surface of the cylinder. When the predetermined amount was completely poured and the coating film was spread evenly, the number of revolutions was increased to 100 rpm, introduced into a hot air circulating dryer, gradually heated to 110 ° C. and heated for 60 minutes. Further, the temperature is raised and heated at 200 ° C. for 20 minutes, the rotation is stopped, and it is slowly cooled to take out the cylindrical mold on which the formed film is formed, and this is introduced into a heating furnace (firing furnace) capable of high-temperature processing. Thus, the temperature was raised to 320 ° C. and heat treatment (firing) was performed for 60 minutes.

After sufficiently cooling, a resin layer was formed on the base layer using a resin layer coating solution having the following constitution.
<Adjustment of coating solution for resin layer>
[Preparation of coating solution for resin layer]
First, the constituent materials shown below were mixed and sufficiently kneaded using a biaxial kneader to prepare a master batch.
<Component material of carbon master batch A for intermediate layer>
-Epoxy-silicone copolymer ALBIFLEX 348 (silicone 60 wt% Nanoresins)
20 parts by weight / carbon black VULCAN XC72 (manufactured by Cabot) 100 parts by weight Using the carbon master batch A, the following constituent materials were mixed to obtain a coating solution.
<Coating liquid constituent material for resin layer>
-Carbon masterbatch A 8 parts by weight-Epoxy-silicone copolymer ALBIFLEX 348 (silicone 60 wt% Nanoresins)
40 parts by weight-methyltetrahydrophthalic anhydride HN-2000 (manufactured by Hitachi Chemical Co., Ltd.) 8 parts by weight

[Production of resin layer on base layer]
On the polyimide base layer produced previously, the resin layer coating solution was similarly cast on the outer surface using a dispenser. The coating amount was such that the final film thickness was 300 μm. When the coating has spread evenly after the predetermined amount has been poured, acrylic resin spherical particles (Techpolymer MBX-SS series (volume average particle size 1 μm)) are used as spherical resin particles using the method of FIG. 4; Sekisui (Manufactured by Kasei Kogyo Kogyo Co., Ltd.) was evenly applied to the surface, and the pressing member of the polyurethane rubber blade was pressed with a pressing force of 100 mN / cm to be fixed to the resin layer.
After finishing the entire surface of the belt, it was put into a hot air circulating dryer while rotating as it was, heated up to 120 ° C. at a heating rate of 4 ° C./min, and heated for 30 minutes. Then, it heated up to 250 degreeC with the temperature increase rate of 4 degree-C / min, and heat-processed for 120 minutes. After stopping the heating, it was gradually cooled to room temperature.
Next, using the same method as in FIG. 4, calcium carbonate (TunexE (manufactured by Shiraishi Calcium Co., Ltd.); particle size 0.3 μm) powder was uniformly applied to the surface, and the pressing member of the polyurethane rubber blade was pressed to make uniform.
The intermediate transfer belt A was obtained by removing from the mold.

It was the same except that [Production of resin layer on base layer] in Example 1 was as follows.
[Production of resin layer on base layer]
On the polyimide base layer produced previously, the resin layer coating solution was similarly cast on the outer surface using a dispenser. The coating amount was such that the final film thickness was 300 μm. When the coating has spread evenly after the predetermined amount has been poured, acrylic resin spherical particles (Techpolymer MBX-SS series (volume average particle size 1 μm)) are used as spherical resin particles using the method of FIG. 4; Sekisui (Made by Kasei Kogyo Kogyo Co., Ltd.) was evenly applied to the surface, and the pressing member of the polyurethane rubber blade was pressed to fix it to the resin layer.
After finishing the entire surface of the belt, it was put into a hot air circulating dryer while rotating as it was, heated up to 120 ° C. at a heating rate of 4 ° C./min, and heated for 30 minutes. Then, it heated up to 250 degreeC with the temperature increase rate of 4 degree-C / min, and heat-processed for 120 minutes. After stopping the heating, it was gradually cooled to room temperature.
Next, using the same method as in FIG. 4, calcium carbonate (TunexE (manufactured by Shiraishi Calcium Co., Ltd.); particle size 0.3 μm) powder was uniformly applied to the surface, and the pressing member of the polyurethane rubber blade was pressed to make uniform.
Next, using the method of FIG. 4, zinc stearate (zinc stearate GF-200; manufactured by NOF Corporation) powder was evenly spread over the surface, and the pressing member of the polyurethane rubber blade was pressed to make uniform.
The intermediate transfer belt B was obtained by removing from the mold.

  An intermediate transfer belt C was obtained in the same manner except that the spherical resin particles in Example 2 were replaced with silicone resin particles (X-52-854 (volume average particle system 0.8 μm product); manufactured by Shin-Etsu Chemical Co., Ltd.).

  An intermediate transfer belt D was obtained in the same manner except that the spherical resin particles in Example 2 were replaced with silicone resin particles (Tospearl 120 (volume average particle system 2.0 μm product); manufactured by Momentive Performance Materials).

  An intermediate transfer belt E was obtained except that the spherical resin particles in Example 2 were replaced with silicone resin particles (KMP701 (volume average particle system 3.5 μm product); manufactured by Shin-Etsu Chemical Co., Ltd.).

  An intermediate transfer belt F was obtained except that the spherical resin particles in Example 2 were replaced with silicone resin particles (Tospearl 2000B (volume average particle system 6.0 μm product); manufactured by Momentive Performance Materials).

  An intermediate transfer belt G was obtained in the same manner except that the spherical resin particles in Example 2 were replaced with acrylic resin spherical particles (Techpolymer XX-16FM (volume average particle size 0.3 μm product); manufactured by Sekisui Plastics Co., Ltd.). .

  An intermediate transfer belt H was obtained in the same manner as in Example 2 except that zinc stearate (zinc stearate GF-200; manufactured by NOF Corporation) was replaced with calcium stearate (calcium stearate GF-200; manufactured by NOF Corporation). It was.

  Intermediate transfer is the same as in Example 2 except that the calcium carbonate (TunexE (manufactured by Shiraishi Calcium); particle size 0.3 μm) is replaced with titanium oxide (MT-150W (Taika); particle size 0.15 μm). Belt I was obtained.

  Calcium carbonate in Example 2 (TunexE (manufactured by Shiraishi Calcium); particle size 0.3 μm) is the same except that it is replaced with spherical silica (Seahoster KEP-30 (manufactured by Nippon Shokubai Co., Ltd.); particle size 0.3 μm). An intermediate transfer belt J was obtained.

  Calcium carbonate in Example 1 (TunexE (manufactured by Shiraishi Calcium); particle size 0.3 μm) is the same except that it is replaced with spherical silica (Seahoster KE-P30 (manufactured by Nippon Shokubai Co., Ltd.); particle size 0.3 μm). An intermediate transfer belt K was obtained.

[Comparative Example 1]
An intermediate transfer belt L was prepared in the same manner as in Example 1 except that fine particles (calcium carbonate (TunexE (manufactured by Shiraishi Calcium); particle size 0.3 μm)) were not included.

[Comparative Example 2]
Fine particles (spherical silica (Seahoster KE-P30 (manufactured by Nippon Shokubai Co., Ltd.); particle size 0.3 μm)) in Example 11 were formed into spherical silica (Seahoster KE-P250 (manufactured by Nippon Shokubai Co., Ltd.); particle size 2.5 μm). The intermediate transfer belt M was manufactured in the same manner except that it was changed.

The intermediate transfer belts A to M of the above examples and comparative examples were mounted on the electrophotographic apparatus of FIG. 5 and the following various evaluations were performed.
In addition, zinc stearate powder was used for the lubricant application device (27).

The projected cross-sectional area ratio and burial ratio of the spherical resin particles on the belt surface in each of the above examples and comparative examples are as shown in Table 1 below.
In addition, Example 8-10 is the same as Example 2, Example 11 and Comparative Examples 1-2 are the same as Example 1.

(1) Measurement of transfer rate As a transfer paper, a paper having a concavo-convex pattern on the surface (continuous amount 175 kg paper resack paper) is used, and an operation for outputting a blue solid image is performed on this and transferred to the paper. The amount of image toner on the previous intermediate transfer belt and the amount of toner remaining on the intermediate transfer belt after transfer to paper were measured to calculate the transfer rate.

（２）１万枚連続画像出力時点における転写率の測定
テストチャートを連続１万枚連続画像出力した後、停止し、上記（１）の方法に従い、転写率を測定した。
（３）１万枚連続画像出力時点における画像評価
テストチャートを連続１万枚連続画像出力した後、連量１７５ｋｇ紙レザック紙及びコート紙（ＦＣ光沢紙（厚口）；リコー製）に全面シアン単色のハーフトーン画像を出力し、異常画像を観察した。

(2) Measurement of transfer rate at the time of continuous image output of 10,000 sheets After outputting 10,000 continuous images of the test chart, the test was stopped and the transfer rate was measured according to the method of (1) above.
(3) Image evaluation at the time of continuous image output of 10,000 sheets After continuous output of 10,000 test charts, the entire surface is cyan on 175kg rezac paper and coated paper (FC glossy paper (thick mouth); manufactured by Ricoh). A monochromatic halftone image was output and an abnormal image was observed.

  The belt of Example 4 was mounted on the apparatus of FIG. 6 from which the lubricant (zinc stearate) coating apparatus (27) was removed, and the same evaluation as described above was performed.

  The results are shown in Table 2.

  As described above, with the configuration of the present invention, an intermediate transfer belt for realizing a high durability and high image quality electrophotographic apparatus that can achieve a high transfer rate irrespective of a transfer medium and can be sustained for a long time is obtained. Can be realized.

In the step of applying and homogenizing calcium carbonate and zinc stearate in Example 4, the same operations were repeated 10 times, 100 times, and 500 times, respectively.
The other conditions were the same, and an intermediate transfer belt X was obtained.
The 60 degree surface glossiness of the belt was measured with a gloss meter (PG-1; manufactured by Nippon Denshoku).
It was tested whether the signal of the optical sensor by the surface of the belt X was detectable.
The results are shown in Table 3.

In the step of applying and homogenizing calcium carbonate and zinc stearate in Example 4, the same operations were repeated 10 times, 100 times, and 500 times, respectively.
The other conditions were the same, and an intermediate transfer belt Y was obtained.
The 60 degree surface glossiness of the belt was measured with a gloss meter (PG-1; manufactured by Nippon Denshoku).
It was tested whether the signal of the surface of the belt Y could be detected by the optical sensor.
The results are shown in Table 3.

In the step of applying and homogenizing calcium carbonate and zinc stearate in Example 4, the same operations were repeated 10 times, 100 times, and 500 times, respectively.
The other conditions were the same, and an intermediate transfer belt Z was obtained.
The 60 degree surface glossiness of the belt was measured with a gloss meter (PG-1; manufactured by Nippon Denshoku).
It was tested whether the signal could be detected by the optical sensor on the surface of the belt Z.
The results are shown in Table 3.

  Thus, by increasing the surface smoothness and glossiness according to the application conditions of the fine particles and the lubricant, the optical sensor can be detected by reflected light, and control using the optical sensor becomes possible.

(Reference in FIG. 1)
11 Base layer 12 Resin layer 13 Particle 14 Lubricant layer (reference numeral in FIG. 2)
21 Resin layer 22 Particles 23 Lubricant layer (reference numeral in FIG. 3)
31 Die drum 32 Belt 33 coated with base layer and resin layer Pressing member 34 Particle 35 Powder coating device (reference numeral in FIG. 4)
P Transfer paper L Laser light 70 Static elimination roller 80 Ground roller 200 Photosensitive drum 201 Photosensitive drum cleaning device 202 Static elimination lamp 203 Charging charger 204 Potential sensor 205 Image density sensor 210 Belt conveying device 230 Revolver developing unit 231Y Y developing machine 231K Bk developing machine 231C C developing machine 231M M developing machine 270 fixing device 271 and 272 fixing roller 500 intermediate transfer unit 501 intermediate transfer belt 502 toner seal member 503 charging charger 504 belt cleaning blade 505 lubricant application brush 506 lubricant 507 primary transfer bias roller 508 Belt drive roller 509 Belt tension roller 510 Secondary transfer counter roller 511 Cleaning counter roller 512 Feedback current detection sensor 513 Toner image 514 Optical sensor 600 Secondary transfer unit 601 Transfer paper guide plate 605 Secondary transfer bias roller 606 Transfer paper neutralization charger 608 Cleaning blade 610 Registration roller 801 Primary transfer power source 802 Secondary transfer power source (reference numeral in FIG. 5) )
P Transfer paper 10 Printer body 12 Image writing unit 13 Image forming unit 14 Paper feeding unit 15 Fixing device 16 Registration roller 20BK, 20M, 20Y, 20C Developing device 21BK, 21M, 21Y, 21C Photoconductor 22 Intermediate transfer belt 23BK, 23M , 23Y, 23C Primary transfer bias roller 25 Belt cleaning member 26 Drive roller 27 Lubricant coating device 50 Transfer conveyor belt 60 Secondary transfer bias roller 70 Static elimination means (reference numeral in FIG. 6)
61 resin layer 62 particles

JP-A-9-230717 JP 2002-162767 A JP 2004-354716 A JP 2007-328165 A JP 2009-75154 A

Claims (10)

In an electrophotographic apparatus using an intermediate transfer belt, the surface of the intermediate transfer belt is composed of independent spherical resin particles arranged in a plane direction, and each fine particle exists between a uniform convex portion and the convex portion. The fine particle layer region comprises fine particles of a smaller particle size and different material than the resin particles, and the surface of the intermediate transfer belt contains a thermosetting elastomer or rubber material. The spherical resin particles are 50% in the depth direction of the resin layer before the heat curing of the resin layer containing the thermosetting elastomer or rubber material. An intermediate transfer belt, wherein the intermediate transfer belt is embedded at an embedding rate of less than 100%, and then fixed to the resin layer by heat curing .   The intermediate transfer belt according to claim 1, wherein the surface of the intermediate transfer belt further contains a lubricant.   The intermediate transfer belt according to claim 2, wherein the lubricant is zinc stearate.   4. The intermediate transfer belt according to claim 1, wherein the spherical resin particles are silicone resin fine particles.   The intermediate transfer belt according to claim 1, wherein the fine particles are calcium carbonate fine particles.   The intermediate transfer belt according to claim 1, wherein the spherical resin particles are monodisperse particles having an average particle diameter of 0.5 μm to 5.0 μm.   The intermediate transfer belt according to any one of claims 1 to 6, wherein the surface of the intermediate transfer belt has a 60-degree glossiness of 20 or more.   An electrophotographic apparatus comprising the intermediate transfer belt according to claim 1.   9. The electrophotographic apparatus according to claim 8, further comprising a mechanism for applying a lubricant to the surface of the intermediate transfer belt. In the intermediate transfer belt manufacturing method, the intermediate transfer belt includes a uniform convex portion in which the surface of the intermediate transfer belt contains a lubricant and at least independent spherical resin particles are arranged in the surface direction, and the convex portion. The fine particle layer region includes fine particles of a smaller particle size and different material than the resin particles, and the surface of the intermediate transfer belt is a thermosetting elastomer or rubber. Formed on a resin layer containing a material, the spherical resin particles are embedded in the depth direction of the resin layer at an embedding rate of more than 50% and less than 100%, at least, the step of forming a uniform particle layer by arranging and embedding step of uniformly dry coated spherical shaped resin particles in the resin layer of the intermediate transfer belt, the leveling process, hard heating said resin layer Step of, then, the production method of the intermediate transfer belt, characterized in that it comprises the step of the fine particles dry coating, the step of homogenizing the particles, a step of dry-coated with a lubricant, a step of equalizing the lubricant.

Images