JP2006154062A - Thermoplastic resin endless belt for electrophotography, electrophotographic apparatus with thermoplastic resin endless belt for electrophotography and method for manufacturing thermoplastic resin endless belt for electrophotography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endless belt for electrophotography which is low in cost, is easily controlled to a desired electric resistance, and excels in mechanical characteristics, and also to provide an electrophotographic apparatus with the endless belt for electrophotography and a method for manufacturing the endless belt for electrophotography. <P>SOLUTION: The thermoplastic resin endless belt for electrophotography contains composite particles obtained by coating surfaces of base particles comprising inorganic particles whose aspect ratio is ≤10 with a carbon-based conductive substance, a content of the composite particles is 5-100 parts by mass based on 100 parts by mass of the thermoplastic resin, and an electric resistance of the endless belt is in a range of 1×10<SP>4</SP>to 1×10<SP>12</SP>Ω. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic endless belt such as a transfer material conveying belt, an intermediate transfer belt, and a photosensitive belt used in an electrophotographic apparatus, an electrophotographic apparatus having the electrophotographic endless belt, and a method of manufacturing the electrophotographic endless belt. It is about.

  In addition to a rigid drum shape, a flexible endless belt shape is used for a transfer conveyance member, an intermediate transfer member, an electrophotographic photosensitive member, a fixing member, etc. used in an electrophotographic apparatus such as a copying machine or a laser beam printer. (Endless belt for electrophotography) is used.

  In recent years, color (full color, etc.) electrophotographic apparatuses have been put into practical use, and the demand for transfer material conveyance belts, intermediate transfer belts, and the like is also increasing.

  This electrophotographic endless belt generally uses a method in which a conductive filler such as carbon black is dispersed in a binder component such as resin, rubber, or elastomer, and is currently not affected by the temperature and humidity of electrical resistance. This is the main method of adjusting electrical resistance in many fields. In particular, carbon black is inexpensive and has an effect of lowering electrical resistance with a small amount of addition, and many studies have been made, but it is very difficult to uniformly disperse it in a binder component. In endless belts with resistance adjustment, the resistance variation within the same electrophotographic endless belt is very large, and at the same time, images are obtained using endless belts with electrical resistance adjustment using conductive filler. When output, there is also a problem that it is difficult to obtain a uniform image.

For such problems, an endless belt manufactured from a raw material obtained by combining organic polymer powder and conductive powder using a powder surface modification device has been proposed. (For example, refer to Patent Document 1). A belt manufactured from a composition in which carbon black, an inorganic filler, and a titanate coupling agent are blended with a thermoplastic resin has been proposed (see, for example, Patent Document 2). However, these methods are insufficient in effect, and when used as an electrophotographic endless belt, image defects may occur.
Japanese Patent No. 3191979 JP 2003-177612 A

  Accordingly, the inventors of the present invention propose a novel seamless belt for an image forming apparatus that solves the above-described problems and is different from the conventional one.

  Accordingly, an object of the present invention is to provide an electrophotographic endless belt having excellent mechanical properties and an electrophotographic apparatus having the electrophotographic endless belt, which can easily control the electric resistance to a desired value at low cost. It is to provide a method for producing the electrophotographic endless belt.

  In order to reduce the environmental fluctuation of the electric resistance, the present inventors are advantageous in that a method of dispersing the conductive filler in the binder component as a method of adjusting the electric resistance, and the manufacturing process is relatively simple. Since it has great merit in terms of cost, it has been intensively studied paying attention to the fact that it is advantageous to use a thermoplastic resin as the binder component of the endless belt.

  An endless belt using a thermoplastic resin has the above-mentioned merits, but there are cases where the characteristics of the endless belt cannot be satisfied depending on the type of conductive agent to be added and the kneading method when dispersing the conductive agent.

  Specifically, an endless belt made of a thermoplastic resin is generally formed by extrusion molding (including inflation molding). If an additive with a large aspect ratio is blended in the molding material during extrusion molding, the additive with a large aspect ratio is oriented in the extrusion direction, and when used as an endless belt, it tears from the end. There was a problem such as. In addition, if an attempt is made to adjust the electrical resistance value of the endless belt using a conductive metal oxide or the like, the amount of conductive agent added increases, the flexibility of the endless belt is impaired, and the belt becomes brittle. . On the other hand, carbon black is an example of a conductive agent that does not exhibit anisotropy when added and can reduce the electrical resistance when added in a small amount. However, as described above, it is very difficult to uniformly disperse carbon black in the binder component. In the endless belt in which the resistance is adjusted by such a method, the resistance within the endless belt for the same electrophotography is reduced. The variation in the angle tends to become very large, and at the same time, the pressure resistance of the endless belt tends to be a problem. For such problems, although carbon black used has a tendency to have better dispersibility than powdered carbon black than pressed products and granulated products, the effect is insufficient. Furthermore, powdered carbon black has a very low bulk specific gravity and is scattered during weighing, making precise weighing difficult, and at the same time, it is scattered during the mixing with thermoplastic resin and the desired blending amount is not blended. As a result, an endless belt having stable electric resistance could not be obtained.

  Therefore, as a result of intensive studies on conductive agents that are easy to disperse and handle while taking advantage of carbon black as described above, the present inventors have made carbon a main component on the surface of inorganic particles having a specific shape. By combining the composite particles obtained by fixing the conductive material to be used as a conductive agent for an electrophotographic endless belt, the so-called medium resistance region, which has been very difficult to control with conventional conductive fillers. It was found that an electrophotographic endless belt having excellent mechanical properties can be obtained.

That is, the present invention contains composite particles coated with a conductive material mainly composed of carbon on the surface of mother particles composed of inorganic particles having an aspect ratio of 10 or less, and the content of the composite particles is thermoplastic. An endless belt made of a thermoplastic resin for electrophotography which is 5 to 100 parts by mass with respect to 100 parts by mass of the resin and has an electric resistance in the range of 1 × 10 ⁴ to 1 × 10 ¹² Ω.

  The present invention also provides an electrophotographic apparatus having the above-described electrophotographic thermoplastic resin endless belt.

  The present invention also provides a method for producing the above-mentioned electrophotographic thermoplastic resin endless belt.

  In the present invention, it is important that the surface of the mother particle made of inorganic particles contains composite particles coated with a conductive material mainly composed of carbon.

  Here, Japanese Patent No. 3191979 proposes a tubular film obtained by extruding a raw material obtained by compounding a mixture of conductive powder and organic polymer powder using a surface modification device. There is a description that an inorganic filler may be contained. However, in the configuration and production method as described in the publication, since the surface of the inorganic particles, which is an essential requirement of the present invention, is not covered with a conductive material mainly composed of carbon, an endless belt (tube-like shape) is obtained. Only films with low pressure resistance can be obtained. That is, in Japanese Patent No. 3191979, a raw material for molding is prepared by compounding conductive powder on the surface of a thermoplastic powder to prepare a kneaded raw material, and melt kneading the kneaded raw material. ing. In other words, since the particles of the conductive powder are compounded on the surface of the thermoplastic resin mother particles, the mother particles melt during melt kneading, and the child particles lose the supported mother particles. Aggregates. As a result, the pressure resistance of the endless belt (tubular film) obtained was low.

  Japanese Patent Application Laid-Open No. 2003-177612 proposes a semiconductive belt composed of a composition in which carbon black, an inorganic filler, and a titanate coupling agent are blended with a thermoplastic resin. Even in such a configuration and production method, the surface of the inorganic particles, which is an essential requirement of the present invention, is not covered with a conductive material mainly composed of carbon. Can only get low. That is, in Japanese Patent Application Laid-Open No. 2003-177612, carbon black is deposited on the surface of inorganic particles by treating the inorganic particles of barium sulfate and carbon black with a titanate coupling agent diluted with a solvent with a ball mill and evaporating the solvent. The mixture is further mixed with the thermoplastic resin to obtain a molding raw material having the inorganic particle-carbon black mixture adhered to the surface of the thermoplastic resin. The effect regarding the improvement of the phenomenon which a thermoplastic resin and carbon black isolate | separate is seen. However, since carbon black is attached to the surface of the inorganic particles, the carbon black falls off from the surface of the inorganic particles during the melt kneading with the thermoplastic resin, and the carbon black is aggregated in the thermoplastic resin. Since it exists, the endless belt (semiconductive flat belt) obtained has low pressure resistance. Further, in the step of evaporating the solvent, the inorganic particles and the carbon black mixed particles are blocked to generate coarse particles, and as an endless belt obtained in the same manner, satisfactory characteristics regarding pressure resistance could not be obtained. .

  Conventionally, when extruding and kneading multiple types of powders, the powders are mixed to some extent by premixing them with a mixing device such as a Henschel mixer (made by Mitsui Mining) or a super mixer (made by Kawata). The extruding and kneading process after this is a commonly performed technique, but when such an operation is performed, carbon black is attached to the surface of the inorganic particles, so that it is contained in the thermoplastic resin. Even when kneading and dispersing, the carbon black is peeled off from the surface of the inorganic particles, and the peeled carbon black is dispersed in an aggregated state in the thermoplastic resin. Thus, only those with low pressure resistance were obtained.

  In the present invention, the determination as to whether or not the surface of the mother particle made of inorganic particles is a composite particle coated with a conductive material mainly composed of carbon is performed using an endless belt, a microtome, or the like. A thin section is prepared, and the ultrathin section for observation is observed with a transmission electron microscope (TEM). Here, if the crystal structure of carbon can be confirmed on the surface of the inorganic particles, it is determined that the surface of the mother particle made of inorganic particles is a composite particle covered with a conductive substance mainly composed of carbon.

  In the present invention, the aspect ratio of the inorganic particles needs to be 10 or less. When plate-like, scale-like, or needle-like inorganic particles having an aspect ratio exceeding 10 are used, when the thermoplastic resin composition is molded, these inorganic particles are oriented in the molding direction. As a result, it becomes electrically and mechanically anisotropic and is not preferable as an electrophotographic endless belt. In the present invention, the aspect ratio of the inorganic particles is a value obtained by measuring the longest part and the shortest part of any 50 inorganic particles from an electron micrograph of the inorganic particles and dividing the average value of the longest part by the average value of the shortest part. It is. The longest part is the absolute maximum length when the electron micrograph is analyzed using the image processing analyzer Luzex III, and the shortest part is the minimum width of the ferret diameter when the same analysis is performed. In the present invention, the particle size of the inorganic particles is an average value of absolute maximum lengths when an arbitrary 50 electron micrographs of the inorganic particles are analyzed using the image processing analyzer Luzex III.

  Moreover, in this invention, content of the said composite particle needs to be 5-100 mass parts with respect to 100 mass parts of thermoplastic resins. If the addition amount is less than 5 parts by mass, even if the electric resistance can be adjusted to a desired value, the variation in electric resistance and the pressure resistance are very low, and it cannot be used. When the added amount of the composite particles exceeds 100 parts by mass, the endless belt becomes brittle and the bending resistance and tear resistance are remarkably lowered, so that it cannot be used.

Further, the endless belt in the present invention needs to have an electric resistance in the range of 1 × 10 ⁴ to 1 × 10 ¹² Ω. If the electrical resistance is lower than 1 × 10 ⁴ Ω, when used as an intermediate transfer member, excessive current flows through the photosensitive member, so that background fog occurs on the image, and when used as a transfer belt. , Paper adsorption force becomes insufficient. On the other hand, if the electric resistance is higher than 10 ¹² Ω, image defects due to discharge occur in both the intermediate transfer belt and the transfer belt.

  In the present invention, the composite particles preferably have a particle size of 0.01 to 10 μm. When the particle diameter is out of this range, the electric resistance of the endless belt obtained tends to vary and at the same time the pressure resistance decreases.

  The inorganic particles that can be used in the present invention are not particularly limited as long as the aspect ratio is 10 or less, but silica, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, Metal oxides such as antimony oxide, ferrites, metal hydroxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, metals such as calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dosonite, hydrotalcite Carbonates, calcium silicates (wollastonite, zonolite), talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, etc. are dispersible, mainly composed of carbon This is preferable from the viewpoint of easy fixation of the conductive substance.

  In addition, the thermoplastic resin that can be used in the present invention can be used without any particular limitation, but is preferably a crystalline resin because of the flexibility of the belt. Specifically, polyamide resin, polyphenylene sulfide resin, thermoplastic fluororesin , Polyalkylene terephthalate resin, polyalkylene naphthalate resin and the like, but are not limited thereto.

  In addition, other components can be added to the electrophotographic endless belt of the present invention within a range not impairing the effects of the invention. Examples of other components include antioxidants, processing aids, lubricants, mold release agents, plasticizers, colorants, nucleating agents, and anti-aging agents.

  The electrophotographic endless belt of the present invention preferably has a thickness of 50 to 250 μm. If the electrophotographic endless belt is too thick, the belt running performance is lowered due to high rigidity and poor flexibility, and there are cases in which bending or shifting occurs during running. On the other hand, if the electrophotographic endless belt is too thin, the tensile strength may decrease or creep may occur due to durable use.

  In addition, the electrophotographic endless belt of the present invention may have a single-layer structure or a multilayer structure composed of a plurality of layers, and may be provided with a meandering prevention member (such as a rib).

  Moreover, as a manufacturing method of the endless belt of the present invention, the following manufacturing methods (a) to (c) are preferable.

  As a manufacturing method with the endless belt of this invention, it is preferable to include at least the following processes (manufacturing method (I)).

(I) A step of obtaining composite particles by combining base particles composed of inorganic particles having a particle size of 0.5 to 10 μm and carbon black by a powder surface modification device (ii) The composite particles and thermoplasticity Step of obtaining raw material for molding by kneading resin with biaxial extruder (iii) Step of extruding the raw material for molding with an extruder having a molding die System (manufactured by Nara Machinery Co., Ltd.), mechano-fusion system (manufactured by Hosokawa Micron), cosmos (manufactured by Kawasaki Heavy Industries), surfing system (manufactured by Nippon Pneumatic Industry), etc. can be used, but carbon black is efficiently applied to the surface of inorganic particles. Hybridization system or mechano-fusion system can be fixed uniformly. It is preferable to use Temu. Here, examples of carbon black that can be used include furnace black, thermal black, gas black, acetylene black, and ketjen black. These carbon blacks are easily available on the market. For example, Denka black (powdered product, granular product, press product, HS-100, etc.) manufactured by Denki Kagaku Kogyo as acetylene black, Ketjen Black manufactured by Lion (EC, EC600JD), Degussa Color Black, Special Black, Printex, High Black, Lamp Black, Colombian Carbon Raven, Cabot Vulcan, Monarch, Legal, Black Pearls, Mogal, Asahi Carbon In addition, Toka Black made by Tokai Carbon and the like are exemplified, but not limited thereto. As a particle size of carbon black to be used, an average particle size is preferably 0.015 to 0.1 μm, and more preferably 0.025 to 0.05 μm. Moreover, it is preferable that carbon black is compounded at a ratio of 0.05 to 30% by mass with respect to the inorganic particles, and more preferably, the conductive material containing carbon as a main component is 30 to 100 with respect to the inorganic particles. It is a percentage by mass.

  Moreover, as another manufacturing method of the endless belt of this invention, it is preferable that at least the following processes are included (manufacturing method (b)).

(I) A step of coating polysiloxane with mother particles composed of inorganic particles having a particle diameter of 0.01 to 10 μm on the surface of the inorganic particles using a grinding device. (Ii) Polysiloxane-coated inorganic particles and carbon Step of obtaining composite particles by compounding black using a grinding device (iii) Step of obtaining a molding raw material by kneading the composite particles and a thermoplastic resin with a biaxial extruder (iv) ) A step of extruding the raw material for molding with an extruder having a molding die. Here, as polysiloxane, polysiloxane ([Chemical Formula 1]), modified polysiloxane ([Chemical Formula 2]), terminal-modified polysiloxane ([Chemical Formula 3]) and the like can be used alone or in combination.

カーボンブラック微粒子粉末の付着効果及び脱離率を考慮すると、メチルハイドロジェンシロキサン単位を有するポリシロキサン、ポリエーテル変成ポリシロキサン及び末端がカルボン酸で変成された末端カルボン酸変成ポリシロキサンが好ましい。ポリシロキサンの被覆量は、無機粒子に対して０．０２〜２０．０質量部であることが好ましい。より好ましくは、０．０３〜１０質量部、更により好ましくは０．０５〜５．０質量部である。０．０２質量部未満の場合には、無機粒子表面にカーボンブラックを固着させることが困難となり、２０．０質量部を超える場合には、無機粒子表面にポリシロキサンが過剰に被覆されることから、その状態でカーボンブラックとの複合化を行った場合、カーボンブラックが凝集しやすくなる。本発明で使用できる摩砕装置としては、ニーダー、バンバリーミキサー、アトライター、エッジランナーミル、ロールミル、ボールミル、サンドミル、SPEXミル、ホモミキサー、プラネタリーミキサー、ナウタミキサー、ディスパーザー、アジター、ジョークラッシャー、スタンプミル、カッターミル、マイクロナイザー等あるがこれらに限定されるものではなく、無機粒子表面にカーボンブラックを効率よく均一に固着させることができることからマイクロス（奈良機械製作所製）が好ましい。また、使用できるカーボンブラックとしては例えば、ファーネスブラック、サーマルブラック、ガスブラック、アセチレンブラック、ケッチェンブラックなどが挙げられる。これらのカーボンブラックは、市場で容易に入手可能であり、例えば、アセチレンブラックとして電気化学工業製のデンカブラック（粉状品、粒状品、プレス品、ＨＳ−１００など）、ライオン製のケッチェンブラック（ＥＣ、ＥＣ６００ＪＤ）、デグサ製のカラーブラック、スペシャルブラック、プリンテックス、ハイブラック、ランプブラック、コロンビアンカーボン製のラーベン、キャボットのバルカン、モナーク、リーガル、ブラックパールズ、モーガル、旭カーボン製の旭カーボン、東海カーボン製のトーカブラックなどが挙げられるがこれらに限定されるものではない。使用するカーボンブラックの粒径としては、平均粒子径が０．０１５〜０．１μmが好ましく、より好ましくは０．０２５〜０．０５μmである。また、無機粒子に対してカーボンブラックが５〜２００質量％の割合で複合化されていることが好ましく、更に好ましくは無機粒子に対して炭素を主成分とする導電性物質が３０〜１００質量％の割合である。

Considering the adhesion effect and desorption rate of the carbon black fine particle powder, polysiloxane having a methylhydrogensiloxane unit, polyether-modified polysiloxane, and terminal carboxylic acid-modified polysiloxane having a terminal modified with a carboxylic acid are preferable. The coating amount of polysiloxane is preferably 0.02 to 20.0 parts by mass with respect to the inorganic particles. More preferably, it is 0.03-10 mass parts, More preferably, it is 0.05-5.0 mass parts. When the amount is less than 0.02 parts by mass, it is difficult to fix carbon black on the surface of the inorganic particles, and when the amount exceeds 20.0 parts by mass, the surface of the inorganic particles is excessively coated with polysiloxane. When composited with carbon black in this state, the carbon black tends to aggregate. As the grinding apparatus that can be used in the present invention, a kneader, a Banbury mixer, an attritor, an edge runner mill, a roll mill, a ball mill, a sand mill, a SPEX mill, a homomixer, a planetary mixer, a nauta mixer, a disperser, an agitator, a jaw crusher, Although there are a stamp mill, a cutter mill, a micronizer, and the like, it is not limited to these, and Micros (manufactured by Nara Machinery Co., Ltd.) is preferable because carbon black can be efficiently and uniformly fixed on the surface of the inorganic particles. Examples of carbon black that can be used include furnace black, thermal black, gas black, acetylene black, and ketjen black. These carbon blacks are easily available on the market. For example, Denka black (powdered product, granular product, press product, HS-100, etc.) manufactured by Denki Kagaku Kogyo as acetylene black, Ketjen Black manufactured by Lion (EC, EC600JD), Degussa Color Black, Special Black, Printex, High Black, Lamp Black, Colombian Carbon Raven, Cabot Vulcan, Monarch, Legal, Black Pearls, Mogal, Asahi Carbon In addition, Toka Black made by Tokai Carbon and the like are exemplified, but not limited thereto. As a particle size of carbon black to be used, an average particle size is preferably 0.015 to 0.1 μm, and more preferably 0.025 to 0.05 μm. Moreover, it is preferable that carbon black is compounded at a ratio of 5 to 200% by mass with respect to the inorganic particles, and more preferably 30 to 100% by mass of the conductive material mainly composed of carbon with respect to the inorganic particles. Is the ratio.

  As another manufacturing method of the endless belt of the present invention, it is preferable to include at least the following steps. (Manufacturing method (c)).

(I) A step of heating and firing inorganic particles in a hydrocarbon atmosphere or a mixed gas atmosphere of a hydrocarbon and a reducing gas and / or an inert gas (ii) Cooling the superheated inorganic particles in an inert gas atmosphere (Iii) A step of obtaining a molding raw material by kneading the composite particles and a thermoplastic resin with a biaxial extruder. iv) Step of Extruding the Molding Raw Material Using an Extruder Having a Molding Die Here, as the hydrocarbon used, both aliphatic hydrocarbons and aromatic hydrocarbons can be used. Examples of the aliphatic hydrocarbon include C1-C20 saturated hydrocarbon, ethylene hydrocarbon, acetylene hydrocarbon, and the like. Examples of aromatic hydrocarbons include benzene, toluene, xylene and the like, polynuclear aromatic hydrocarbons such as naphthalene and anthracene, and halides of the above-mentioned various hydrocarbons. These hydrocarbons can be used individually by 1 type or in mixture of 2 or more types. Examples of the reducing gas used include hydrogen gas, hydrogen monoxide gas, and ammonia gas. Examples of the inert gas include nitrogen gas, argon gas, helium gas, xenon gas, and carbon dioxide gas, and the above reducing gas and inert gas may be used alone or in combination of two or more. You may mix and use. When the reducing gas is mixed with the hydrocarbon and used, the mixing ratio of the reducing gas and the hydrocarbon is usually preferably in the range of 90:10 to 10:90. Is preferred. The temperature for the heating and firing is preferably a temperature within the range of 1300 ° C. or lower and higher than the temperature of decomposition of the hydrocarbon used, that is, carbon deposition. If the temperature for heating and baking is too low, the carbon conductive layer cannot be formed on the surface of the inorganic material, and if the temperature for heating and baking is too high, the shape of the inorganic material as the core material may collapse. The decomposition temperature of the hydrocarbon varies depending on the hydrocarbon used. For example, the deposition temperature range of carbon in the case of methane is about 900 to 950 ° C., and in the case of n-propane, it is about 950 to 1000 ° C. In the case of benzene, the temperature is low, and carbon is deposited at about 750 to 800 ° C. From the viewpoint of the conductivity of the deposited carbon conductive layer, it is desirable that the treatment be performed at a temperature as high as possible, for example, 1150 to 1300 ° C. In the atmosphere of heating and firing, a reducing gas is not necessarily required. For example, by introducing hydrocarbon at about 500 to 1000 ° C. under an inert gas stream such as nitrogen gas, the carbon layer is decomposed. Can also be deposited. After depositing the carbon conductive layer on the surface of the inorganic material, the temperature is lowered to room temperature. Since this may occur, it is preferable to lower the temperature while flowing an inert gas, a hydrogen gas, a hydrocarbon gas, or a mixed gas thereof even when the temperature is lowered. For example, a tunnel kiln, an electric furnace, a rotary kiln, or a fluidized firing method can be used for heating and firing in a hydrocarbon atmosphere or a mixed gas atmosphere, but is not limited thereto.

  Here, the steps of extrusion molding with an extruder having a molding die in the production methods (A) to (C) above are an extrusion sheet molding method using a T die and an extrusion tube molding using an annular die. Method, an inflation molding method using an annular die, an extrusion blow molding method using an annular die, and the like, but since a seamless belt (seamless belt) can be obtained, a molding method using an annular die is preferable. .

  FIG. 1 is a diagram showing an example of a schematic configuration of an apparatus for producing an electrophotographic endless belt that employs an inflation molding method using an annular die.

  First, a thermoplastic raw material, inorganic particle-conductive material composite particles, and other additives as necessary are premixed based on a prescribed formulation, and kneaded and dispersed to obtain a molding material obtained. The hopper 102 is charged into the extruder 101. The temperature and screw configuration in the extruder 101 are selected so that the forming raw material is in a uniform molten state and has a melt viscosity that allows belt forming.

  The forming raw material is melted and kneaded in the extruder 101 to become a melt and enters the annular die 103. The annular die 103 is provided with a gas introduction path 104. When a gas 105 such as air is blown into the annular die 103 from the gas introduction path 104, the melt that has passed through the annular die 103 expands and expands in the radial direction. To do. The molding may be performed without blowing the gas 105 into the gas introduction path 104.

  The expanded molded body 106 is pulled upward while being cooled by the cooling ring. By passing between the dimension stabilizing guides 107 having a predetermined dimension when pulled up, the circumferential length (circumferential length) of the electrophotographic endless belt is determined, and the electrophotographic endless belt is cut into a desired length by the cutter 109. Thus, the length (width) of the electrophotographic endless belt in the bus line direction is determined.

  In this way, an electrophotographic endless belt can be obtained.

  The above description relates to a method of manufacturing an electrophotographic endless belt having a single layer structure. However, in the case of an electrophotographic endless belt having a two layer structure, as shown in FIG. A second hopper) is installed, and the melt from the extruder 101 and the melt from the extruder 201 are simultaneously fed to the annular die 103, and the two layers are expanded and expanded simultaneously, thereby electrophotographic endless having a two-layer structure. A belt can be obtained. When there are three or more layers, an extruder may be prepared according to the number of layers.

  In addition, as a method of removing the endless belt crease generated by the inflation molding method or smoothing the endless belt surface, for example, a pair of cylindrical shapes made of materials having different coefficients of thermal expansion are used. The method to use is mentioned.

  Specifically, after the thermal expansion coefficient of the small-diameter cylindrical mold (inner mold) is larger than the thermal expansion coefficient of the large-diameter cylindrical mold (outer mold), the endless belt molded on this inner mold is covered. The inner mold is inserted into the outer mold so that the cylindrical film is sandwiched between the inner mold and the outer mold. The gap between the inner mold and the outer mold is obtained by calculating the difference between the heating temperature and the coefficient of thermal expansion between the inner mold and the outer mold and the required pressure.

  From the inside, the mold set in the order of the inner mold, endless belt, and outer mold is heated to near the softening point temperature of the thermoplastic resin used for the endless belt. Since the inner mold having a large coefficient of thermal expansion tends to expand beyond the inner diameter of the outer mold by heating, a uniform pressure is applied to the entire endless belt. At this time, the surface of the endless belt that has reached the vicinity of the softening point is pressed against the inner surface of the outer mold, and the crease can be removed. Then, the endless belt from which the crease has been removed can be obtained by cooling and removing the endless belt from the mold. According to this method, it is possible to adjust the dimensions and improve the surface properties at the same time. Moreover, if the endless belt which covers the inner mold is stacked, a multi-layered endless belt can be obtained.

  Also, after joining the film ends by ultrasonic welding or by winding the sheet film around the inner mold as described above, the outer mold is set and heated. It is good also as an endless belt by joining.

In addition, as a particularly preferable production method (d) of the endless belt of the present invention, the composite particles and the thermoplastic resin in the production methods (a) to (c) above are kneaded and kneaded with a biaxial extruder. In the process of obtaining the raw material for molding,
(I) a thermoplastic resin charging step of charging the thermoplastic resin into a twin screw extruder;
(Ii) A production method including a composite particle charging step of charging the composite particles into the twin screw extruder when the thermoplastic resin charged into the twin screw extruder is melted. As described above, by introducing the composite particles in a molten state of the thermoplastic resin, peeling of the conductive material mainly composed of carbon from the surface of the composite particles is suppressed, and the composite particles are introduced into the thermoplastic resin. Dispersion can be further improved. For this reason, it is preferable that the variation in electric resistance can be made extremely small, and at the same time, the pressure resistance of the endless belt can be improved.

  Here, in the manufacturing methods of (i) to (d) above, there is no particular limitation on the twin-screw extruder, for example, TEX made by Nippon Steel Works (JSW), TEM made by Toshiba Machine, PCM made by Ikegai, etc. Can be used.

  FIG. 3 shows an example of a schematic configuration of the biaxial extruder.

  The components constituting the molding material are generally charged from the hopper 302 into the biaxial extruder 301 at a time, but effectively prevent the conductive material from peeling off from the inorganic particle surface as described above. In addition, since dispersion of the inorganic particle-conductive substance composite particles in the thermoplastic resin can be further improved, a thermoplastic resin or the like is introduced into the upstream hopper 302 of the biaxial extruder 301, and the thermoplastic resin is melted. A method in which the inorganic particle-conductive substance composite particles are introduced into the downstream hopper 302 ′ of the biaxial extruder 301 in the stage is particularly preferable. The material melt-kneaded by the biaxial extruder is extruded from the strand die 303 as a strand 304, cooled through a water tank 305, and then passed through a strand cutter 306 to become a molding material. Here, it is preferable that the components constituting the molding raw material are fed to the hoppers 302 and 302 using a gravimetric weighing feeder because a molding raw material having stable characteristics can be obtained.

  The kneading with the biaxial extruder may be carried out once, or the one once passed through the biaxial extruder may be kneaded again (twice kneaded) with the biaxial extruder.

  FIG. 4 shows an example of a schematic configuration of an intermediate transfer type color electrophotographic apparatus. Transfer of the toner image from the electrophotographic photosensitive member to the transfer material is mainly performed by a primary transfer member, an intermediate transfer belt, and a secondary transfer member.

  In FIG. 4, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed.

  The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by the primary charging member 3, and then output from an exposure means (not shown) such as slit exposure or laser beam scanning exposure. The exposure light (image exposure light) 4 is received. The exposure light at this time is exposure light corresponding to the first color component image (for example, yellow component image) of the target color image. In this way, the first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the electrophotographic photoreceptor 1.

  The intermediate transfer belt 11 stretched by the stretching roller 12 and the secondary transfer counter roller 13 has substantially the same peripheral speed as that of the electrophotographic photosensitive member 1 in the direction of the arrow (for example, 97 to 97% of the peripheral speed of the electrophotographic photosensitive member 1). 103%).

  The first color component electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is the first color contained in the developer carried on the first color developer carrying body (yellow developer carrying body) 5Y. The first toner image (yellow toner image) is developed by developing with toner (yellow toner). Next, the first color toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is transferred between the electrophotographic photosensitive member 1 and the primary transfer member 6p by the primary transfer bias from the primary transfer member (primary transfer roller) 6p. Primary transfer is sequentially performed on the surface of the intermediate transfer belt 11 that passes between them.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the first color toner image is cleaned by the cleaning member 7 to remove the developer (toner) remaining after the primary transfer, and then used for image formation of the next color. The

  The second color toner image (magenta toner image), the third color toner image (cyan toner image), and the fourth color toner image (black toner image) are also formed on the surface of the electrophotographic photoreceptor 1 in the same manner as the first color toner image. And are sequentially transferred onto the surface of the intermediate transfer belt 11. Thus, a synthetic toner image corresponding to the target color image is formed on the surface of the intermediate transfer belt 11. During primary transfer of the first to fourth colors, the secondary transfer member (secondary transfer roller) 6 s and the charge applying member (charge applying roller) 7 r are separated from the surface of the intermediate transfer belt 11.

  The composite toner image formed on the surface of the intermediate transfer belt 11 is transferred from the transfer material supply means (not shown) to the secondary transfer counter roller 13 and the intermediate transfer belt 11 by the secondary transfer bias from the secondary transfer member 6s. Secondary transfer is sequentially performed on the transfer material (paper or the like) P taken out and fed between the next transfer member 6s (contact portion) in synchronization with the rotation of the intermediate transfer belt 11.

  The transfer material P, which has received the transfer of the synthetic toner image, is separated from the surface of the intermediate transfer belt 11 and introduced into the fixing means 8 to receive image fixing, thereby printing out as a color image formed product (print, copy) outside the apparatus. Out.

  The charge applying member 7r is brought into contact with the surface of the intermediate transfer belt 11 after the synthetic toner image is transferred. The charge imparting member 7r imparts a charge having a reverse polarity to that of the secondary transfer remaining developer (toner) on the surface of the intermediate transfer belt 11 to the primary transfer. The developer (toner) remaining in the secondary transfer to which a charge having a polarity opposite to that at the time of primary transfer is applied is in contact with the electrophotographic photosensitive member 1 and the intermediate transfer belt 11 and in the vicinity thereof. It is electrostatically transferred to the surface. In this way, the surface of the intermediate transfer belt 11 after the transfer of the synthetic toner image is cleaned by receiving the developer (toner) remaining after transfer. The secondary transfer residual developer (toner) transferred to the surface of the electrophotographic photosensitive member 1 is removed by the cleaning member 7 together with the primary transfer residual developer (toner) of the surface of the electrophotographic photosensitive member 1. Transfer of the remaining secondary transfer developer (toner) from the intermediate transfer belt 11 to the electrophotographic photosensitive member 1 can be performed at the same time as the primary transfer, so that the throughput is not reduced.

  In addition, the surface of the electrophotographic photosensitive member 1 after removal of the developer (toner) remaining after transfer by the cleaning member 7 may be subjected to static elimination treatment with pre-exposure light from the pre-exposure means, but as shown in FIG. When contact charging using a roller-shaped primary charging member (charging roller) or the like is employed for charging the surface of the electrophotographic photosensitive member, pre-exposure is not necessarily required.

  FIG. 5 shows an example of a schematic configuration of an inline type color electrophotographic apparatus. Transfer of the toner image from the electrophotographic photosensitive member to the transfer material is mainly performed by a transfer material conveyance belt and a transfer member.

  In FIG. 5, reference numerals 1Y, 1M, 1C, and 1K denote cylindrical electrophotographic photosensitive members (first to fourth color electrophotographic photosensitive members), and the directions of the arrows are about axes 2Y, 2M, 2C, and 2K, respectively. Are rotated at a predetermined peripheral speed.

  The surface of the first color electrophotographic photosensitive member 1Y that is rotationally driven is uniformly charged to a predetermined positive or negative potential by the primary charging member 3Y for the first color, and then subjected to slit exposure, laser beam scanning exposure, or the like. Exposure light (image exposure light) 4Y output from exposure means (not shown) is received. The exposure light 4Y is exposure light corresponding to a first color component image (for example, a yellow component image) of a target color image. Thus, a first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the first color electrophotographic photoreceptor 1Y.

  The transfer material conveyance belt 14 stretched by the stretching roller 12 has substantially the same peripheral speed (for example, the first color to the first color) as the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K in the direction of the arrow. The four-color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K are rotated at a rotational speed of 97 to 103%. Further, the transfer material (paper or the like) P fed from the transfer material supply means (not shown) is electrostatically carried (adsorbed) on the transfer material transport belt 14 and is electrophotographic for the first to fourth colors. The photosensitive members 1Y, 1M, 1C, and 1K are sequentially conveyed between the transfer material conveyance belts (contact portions).

  The first color component electrostatic latent image formed on the surface of the first color electrophotographic photosensitive member 1Y is developed with the first color toner contained in the developer carried on the first color developer carrying member 5Y. Thus, a first color toner image (yellow toner image) is obtained. Next, the first color toner image formed and supported on the surface of the first color electrophotographic photosensitive member 1Y is transferred to the first color by the transfer bias from the first color transfer member (first color transfer roller) 6Y. The image is sequentially transferred onto the transfer material P carried on the transfer material conveying belt 14 that passes between the electrophotographic photosensitive member 1Y and the first color transfer member 6Y.

  The surface of the first color electrophotographic photoreceptor 1Y after the transfer of the first color toner image is subjected to removal of the transfer residual developer (toner) by the first color cleaning member (first color cleaning blade) 7Y. After the surface is cleaned, it is repeatedly used for forming a first color toner image.

  The first color electrophotographic photosensitive member 1Y, the first color primary charging member 3Y, the first color exposure means, the first color developer carrying member 5Y, and the first color transfer member 6Y are collectively used for the first color. This is called an image forming unit.

  Second color image having second color electrophotographic photoreceptor 1M, second color primary charging member 3M, second color exposure means, second color developer carrying member 5M, and second color transfer member 6M. A third portion having a forming portion, a third color electrophotographic photosensitive member 1C, a third color primary charging member 3C, a third color exposure means, a third color developer carrier 5C, and a third color transfer member 6C. A color image forming section, a fourth color electrophotographic photosensitive member 1K, a fourth color primary charging member 3K, a fourth color exposure means, a fourth color developer carrying member 5K, and a fourth color transfer member 6K. The operation of the fourth color image forming unit is the same as the operation of the first color image forming unit, and is carried on the transfer material P that is carried on the transfer material conveyance belt 14 and to which the first color toner image is transferred. A two-color toner image (magenta toner image), a third color toner image (cyan toner image), and a fourth color toner image (black toner image) are sequentially transferred. We are. In this way, a composite toner image corresponding to the target color image is formed on the transfer material P carried on the transfer material conveyance belt 14.

  The transfer material P on which the synthetic toner image is formed is separated from the surface of the transfer material conveying belt 14 and introduced into the fixing means 8 to receive image fixing, thereby printing out as a color image formed product (print, copy) outside the apparatus. Out.

  Also, the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K after the remaining developer (toner) after transfer is removed by the first to fourth color cleaning members 7Y, 7M, 7C, and 7K. The surface of the toner may be neutralized by pre-exposure light from pre-exposure means, but as shown in FIG. 5, a roller-shaped primary charging member (charging roller) is used for charging the surface of the electrophotographic photosensitive member. In the case of adopting the conventional contact charging, the pre-exposure is not necessarily required.

  In FIG. 5, reference numeral 15 denotes an adsorption roller for adsorbing the transfer material onto the transfer material conveyance belt, and 16 denotes a separation charger for separating the transfer material from the transfer material conveyance belt.

  FIG. 6 shows another example of the schematic configuration of an intermediate transfer type color electrophotographic apparatus. In the case of this intermediate transfer method, the transfer of the toner image from the electrophotographic photosensitive member to the transfer material is mainly performed by a primary transfer charging member, an intermediate transfer belt, and a secondary transfer charging member.

  In FIG. 6, reference numerals 1Y, 1M, 1C, and 1K denote cylindrical electrophotographic photosensitive members (first to fourth color electrophotographic photosensitive members), and the directions of the arrows are about axes 2Y, 2M, 2C, and 2K, respectively. Are rotated at a predetermined peripheral speed.

  The surface of the first color electrophotographic photosensitive member 1Y that is rotationally driven is uniformly charged to a predetermined positive or negative potential by the primary charging member 3Y for the first color, and then subjected to slit exposure, laser beam scanning exposure, or the like. Exposure light (image exposure light) 4Y output from exposure means (not shown) is received. The exposure light 4Y is exposure light corresponding to a first color component image (for example, a yellow component image) of a target color image. Thus, a first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the first color electrophotographic photoreceptor 1Y.

  The intermediate transfer belt 11 stretched by the stretching roller 12 and the secondary transfer counter roller 13 has substantially the same peripheral speed as that of the electrophotographic photosensitive member 1 in the direction of the arrow (for example, 97 to 97% of the peripheral speed of the electrophotographic photosensitive member 1). 103%).

  The first color component electrostatic latent image formed on the surface of the first color electrophotographic photosensitive member 1Y is developed with the first color toner contained in the developer carried on the first color developer carrying member 5Y. Thus, a first color toner image (yellow toner image) is obtained. Next, the first color toner image formed and supported on the surface of the first color electrophotographic photoreceptor 1Y is transferred by the primary transfer bias from the first color primary transfer member (first color primary transfer roller) 6pY. Primary transfer is sequentially performed on the surface of the intermediate transfer belt 11 passing between the first color electrophotographic photoreceptor 1Y and the first color primary transfer member 6pY.

  The surface of the first color electrophotographic photoreceptor 1Y after the transfer of the first color toner image is subjected to removal of the transfer residual developer (toner) by the first color cleaning member (first color cleaning blade) 7Y. After the surface is cleaned, it is repeatedly used for forming a first color toner image.

  The first color electrophotographic photosensitive member 1Y, the first color primary charging member 3Y, the first color exposure means, the first color developer carrying member 5Y, and the first color primary transfer charging member 6pY are grouped together as a first. This is called a color image forming unit.

  Second color electrophotographic photosensitive member 1M, second color primary charging member 3M, second color exposure means, second color developer carrying member 5M, second color primary transfer member 6pM The image forming unit includes a third color electrophotographic photosensitive member 1C, a third color primary charging member 3C, a third color exposure unit, a third color developer carrier 5C, and a third color primary transfer member 6pC. Third color image forming portion, fourth color electrophotographic photosensitive member 1K, fourth color primary charging member 3K, fourth color exposure means, fourth color developer carrier 5K, fourth color primary transfer. The operation of the fourth color image forming unit having the member 6pK is the same as the operation of the first color image forming unit, and the second color toner image (magenta toner image) and the third color are formed on the surface of the intermediate transfer belt 11. A color toner image (cyan toner image) and a fourth color toner image (black toner image) are sequentially primary transferred. Thus, a synthetic toner image corresponding to the target color image is formed on the surface of the intermediate transfer belt 11.

  The composite toner image formed on the surface of the intermediate transfer belt 11 is transferred from the transfer material supply means (not shown) to the secondary transfer counter roller 13 and the intermediate transfer belt 11 by the secondary transfer bias from the secondary transfer member 6s. Secondary transfer is sequentially performed on the transfer material (paper or the like) P taken out and fed between the next transfer member 6s (contact portion) in synchronization with the rotation of the intermediate transfer belt 11.

  The transfer material P, which has received the transfer of the synthetic toner image, is separated from the surface of the intermediate transfer belt 11 and introduced into the fixing means 8 to receive image fixing, thereby printing out as a color image formed product (print, copy) outside the apparatus. Out.

  The surface of the intermediate transfer belt 11 after the transfer of the composite toner image is cleaned by receiving the developer (toner) remaining after the secondary transfer by the intermediate transfer belt cleaning member 7 ′, and then the next composite toner image. Used for forming.

  Also, the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K after the remaining developer (toner) after transfer is removed by the first to fourth color cleaning members 7Y, 7M, 7C, and 7K. The surface of the toner may be neutralized by pre-exposure light from pre-exposure means. However, as shown in FIG. 6, a roller-shaped primary charging member (primary charging roller) is used to charge the surface of the electrophotographic photosensitive member. When the contact charging used is adopted, pre-exposure is not always necessary.

  The electrophotographic endless belt of the present invention can be suitably used for the above-described intermediate transfer belt, transfer material conveyance belt, and the like.

  As described above, the electrophotographic endless belt of the present invention has been described mainly focusing on the case where it is used as an intermediate transfer belt or a transfer material conveying belt. However, the electrophotographic endless belt of the present invention is an intermediate transfer belt or a transfer material conveying belt. In addition, the present invention can be applied to all endless belts used in electrophotographic apparatuses such as photosensitive belts, transfer belts, conveying belts other than transfer material conveying belts, fixing belts, developing belts, charging belts, and paper feeding belts.

  The electrophotographic endless belt of the present invention may be mounted on the electrophotographic apparatus main body as it is, or may be used as an endless belt cartridge that is detachable from the electrophotographic apparatus main body. For example, a process cartridge in which the electrophotographic endless belt of the present invention is integrated with an electrophotographic process member such as an electrophotographic photosensitive member or a primary charging member may be used.

  As described above, according to the present invention, the electrical resistance can be easily controlled to a desired value at a low cost, the environmental variation of the electrical resistance is small, and the mechanical characteristics are excellent. And an electrophotographic endless belt that does not cause breakage, an electrophotographic apparatus having the electrophotographic endless belt, and a method of manufacturing the electrophotographic endless belt.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.

Preparation of composite particles by powder surface modification device (Preparation of composite particles 1-1)
Using a hybridizer (manufactured by Nara Machinery Co., Ltd.), which is a powder surface modification device, 100 parts by mass of magnesium hydroxide (particle size 3 μm, aspect ratio 2) and 5 parts by mass of carbon black (particle size 0.03 μm) Composite particles having carbon black fixed on the surface of magnesium hydroxide were prepared.

(Production of Composite Particle 1-2 to Composite Particle 1-11)
Composite particles were produced in the same manner as composite particles 1-1 except that the blending amounts of the inorganic particle species, CB species, and CB were changed as shown in Table 1.

（実施例１）
下記配合からなる成形用原料を作製した。

Example 1
A forming raw material having the following composition was prepared.

Compounding thermoplastic resin component Polyamide 610 resin 60 parts by mass
Polyamide 12 resin 40 parts by weight Composite particles Composite particles 1-1 30 parts by weight A twin-screw extruder provided with two raw material hoppers (TEX65: manufactured by Nippon Steel) as shown in FIG. Was used.

  Here, the two types of materials of the thermoplastic resin component are pre-weighed, and the uniformly mixed pellets using a tumbler mixer are charged from the upstream hopper 302 using a gravimetric weighing feeder, The composite particles were added from the downstream hopper 302 'using a weight-type weighing feeder and kneaded. The discharge amount during kneading was 100 kg / hr, and the set temperature of the extruder was 260 ° C.

  A tube-shaped film was formed by inflation molding of the obtained molding raw material using an apparatus having the configuration shown in FIG. The temperature of the molding machine was 260 ° C.

  Next, using a set of cylindrical molds made of materials having different coefficients of thermal expansion and having different diameters, the folds of the obtained endless belt were removed, the surface smoothness was adjusted, and the size was obtained as described above. Was adjusted. In addition, heating of the mold set in the order of the inner mold, the obtained endless belt, and the outer mold from the inside was performed at 220 ° C. for 20 minutes.

  Next, both ends of the endless belt subjected to crease removal, surface smoothness adjustment, and size adjustment were precisely cut to obtain an electrophotographic endless belt having a circumference of 480 mm, a width of 250 mm, and a thickness of 100 μm. . The electrophotographic endless belt was provided with a meandering prevention member on the back surface.

  The mechanical characteristics and electrical characteristics of the obtained electrophotographic endless belt were evaluated by the following methods. In addition, the above-described method was used to confirm whether or not the surface of the inorganic particles in the endless belt was coated with a conductive material mainly composed of carbon. The results are shown in Table 3.

Evaluation of mechanical properties-Evaluation of bending resistance Bending resistance was evaluated by a bending test apparatus having a configuration shown in FIG.

  The electrophotographic endless belt is cut into a strip shape having a width of 20 mm and a length of 200 mm, and the strip sample 700 is set on the chucks 702 and 703 of the bending test apparatus. The chuck 703 is connected to the crank 704 side, and a load (F) of 1 kg is applied to the chuck 702. By driving the crank 704 (rotating the disk in the direction of the arrow), the strip-shaped sample 700 reciprocates on the roller (free rotation) 701 and repeatedly performs bending and stretching operations 1 million times.

  The roller 701 has a diameter of 10 mm, a moving stroke of 20 mm, and a speed of 1 reciprocation / 0.5 seconds.

  The strip-shaped sample after this test was visually inspected, and it was judged that Δ or more was practical.

○: No cracks or fractures △: Very slight cracks are observed ×: Significant cracks are observed or fractured ・ Evaluation of tear resistance Evaluation of tear resistance using the bending test apparatus shown in FIG. Went.

  Cut the electrophotographic endless belt into a strip with a width of 20 mm and a length of 200 mm, and insert a 3 mm long notch into the position of 100 mm in length using a sharp blade (razor, etc.) and sample as in the bending resistance test. Was repeatedly bent and stretched.

  When the operation was repeated 10,000 times, the tear resistance was evaluated as follows, and those with Δ or more were judged to be practical.

Evaluation criteria for tear resistance ○: The length of the cut portion is less than 5 mm. Δ: The length of the cut portion is 5 mm or more and less than 10 mm. X: The length of the cut portion is 10 mm or more or has been torn in the middle. Measurement of variation in electrical resistance As an electrical characteristic measuring apparatus, an apparatus as shown in FIG. 8 is used. The endless belt 500 is stretched by a driving roller 501 (made of JIS A hardness 60 ° rubber, diameter 30 mm), an electrode roller 502 (aluminum, diameter 30 mm) and a tension roller 504 (aluminum, diameter 20 mm, tension load 50 N). It is built. Further, the power supply roller 503 is in contact with the electrode roller 502 with a force of 20 N, and the power supply roller 503 is a rubber roll having a sufficiently low resistance with respect to a belt for measuring resistance, and has a JIS A hardness of 60 °, The diameter is 30 mm.

  The endless belt 500 is driven in the direction of the arrow at a speed of 100 mm / sec by the driving roller 501, and a voltage of +100 V is applied to the power supply roller 503 from a high voltage power supply HV (for example, MODEL610C manufactured by TREK). Between the two ends of the resistor R having a known electric resistance disposed between the recorder Rec. (Oscilographic recorder ORM1200 manufactured by Yokogawa Electric Corporation), and the current flowing between the power supply roller 503 and the electrode roller 502 via the endless belt is calculated from the potential difference and the electrical resistance of the resistor, The resistance value of the transfer conveyance seamless belt is obtained by calculating from the current and the applied voltage of 100V. Here, the recorder Rec. With the sampling rate of 100 Hz, the resistance value for one revolution of the belt is measured, the average value of the data for one revolution is defined as the resistance value Rave of the seamless belt, and the highest resistance data Rmax within one revolution of the belt Rmax / Rmin divided by the lowest data Rmin is defined as a variation in resistance value of the transfer / conveyance seamless belt.

<Measurement conditions>
Measurement atmosphere: 23 ° C./55% RH (N / N)
In addition, the measurement sample is allowed to stand in an environment of 23 ° C. and 55% RH for 12 hours or more in advance.

-Confirmation of pressure resistance In a N / N environment, a 300V, 500V and 1000V DC voltage is applied to the feeding roller 503 from the high voltage power supply HV of the electrical characteristic measuring apparatus shown in FIG. The presence or absence of dielectric breakdown of the belt 500 was confirmed.

  The pressure resistance of the endless belt was evaluated as follows, and Δ or more was judged to be practical.

◎: Dielectric breakdown did not occur even when 1000V was applied. ○: Dielectric breakdown did not occur when 500V was applied, but did not break when 1000V was applied. △: Dielectric breakdown did not occur when 300V was applied. What causes dielectric breakdown when 300V is applied Image output test In addition, the obtained electrophotographic endless belt is mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 4 as an intermediate transfer belt, and N / N, L / Under each environment of L and H / H, an output test of a full color image was performed, and initial image evaluation was performed. As a result of the evaluation, it was possible to obtain a good image having no image defect under any environment.

  Thereafter, an endurance test of 10,000 output images was performed under each environment. Observation of the electrophotographic endless belt (transfer material transport belt) after the durability test revealed no abnormalities such as cracks, cracks and tears. The evaluation results are shown in Table 3.

(Example 2, Example 3)
An endless belt was prepared in the same manner as in Example 1 except that the composition of the raw material for molding, kneading temperature, and molding temperature were as shown in Table 2, and the same evaluation as in Example 1 was performed. The results are shown in Table 3.

(Example 4 to Example 7)
The endless belt was prepared in the same manner as in Example 1 except that the composition of the raw materials for molding, the kneading temperature, and the molding temperature were as shown in Table 2, and the circumference of the endless belt was changed to 750 mm, and mechanical characteristics and electrical characteristics were evaluated. Performed as in Example 1. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 5 as a transfer conveyance belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Examples 8 to 12)
The endless belt was prepared in the same manner as in Example 1 except that the composition of the molding raw material, the kneading temperature and the molding temperature were as shown in Table 2, and the circumference of the endless belt was changed to 850 mm, and the mechanical characteristics and electrical characteristics were evaluated. Performed as in Example 1. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 6 as an intermediate transfer belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Example 13)
An endless belt was prepared in the same manner as in Example 1 except that the thermoplastic resin component and the composite particles were added from the upstream hopper 302 in FIG. And an image output test was conducted. The evaluation results are shown in Table 3.

(Comparative Example 1)
An endless belt was produced in the same manner as in Example 1 except that the molding raw material was changed as follows.

Compounding thermoplastic resin component Polyamide 610 resin 60 parts by mass
40 parts by mass of polyamide 12 resin
Carbon black (particle size: 0.03 μm) 30 parts by mass The obtained endless belt was evaluated for mechanical and electrical properties and subjected to an image output test in the same manner as in Example 1. As shown in Table 3, since significant transfer unevenness due to the resistance variation of the belt was confirmed from the beginning, the durability test was not performed.

(Comparative Example 2)
An endless belt was produced in the same manner as in Example 1 except that the molding raw material was changed as follows.

Compounding thermoplastic resin component Polyamide 610 resin 60 parts by mass
40 parts by mass of polyamide 12 resin
Polyetheresteramide 30 parts by mass The obtained endless belt was subjected to evaluation of mechanical properties and electrical properties and an image output test in the same manner as in Example 1. As shown in Table 3, since the remarkable image defect considered to be caused by the resistance increase in the L / L environment was confirmed, the durability test was not performed.

(Comparative Example 3, Comparative Example 4)
An endless belt was produced in the same manner as in Example 1 except that the forming raw material was changed as shown in Table 2, and the same evaluation as in Example 1 was performed. The results are shown in Table 3.

(Comparative Example 5)
Polyvinylidene fluoride resin powder with 100 parts by weight of polyvinylidene fluoride resin powder and 10 parts by weight of carbon black (particle size 0.03 μm) using a hybridizer (manufactured by Nara Machinery Co., Ltd.) as a powder surface modification device Composite particles having carbon black fixed on the surface were prepared.

  An endless belt was produced in the same manner as in Example 1 except that 110 parts by mass of the composite particles and 10 parts by mass of zinc oxide were mixed using a Henschel mixer (Mitsui Mine) and then kneaded in the same manner as in Example 13. Characteristics and electrical characteristics were evaluated and an image output test was performed. As shown in Table 3, since significant transfer unevenness due to the resistance variation of the belt was confirmed from the beginning, the durability test was not performed.

摩砕装置による複合粒子の作製
（複合粒子２−１の作製）
シリカ（粒径０．０３μm、アスペクト比１．１）１００質量部とメチルハイドロジェンポリシロキサン３質量部を、摩砕装置であるマイクロス（奈良機械製作所製）を用いてシリカ表面にメチルハイドロジェンポリシロキサン処理を行い、その後シリカ１００質量部に対して１００質量部のカーボンブラック（粒径０．０３μm）を添加して摩砕処理を行い、シリカ表面にカーボンブラックが固着した複合粒子を作製した。

Production of composite particles by grinding device (Production of composite particles 2-1)
100 parts by mass of silica (particle size: 0.03 μm, aspect ratio: 1.1) and 3 parts by mass of methylhydrogenpolysiloxane were added to the surface of the methylhydrogen using Micros (manufactured by Nara Machinery Co., Ltd.). Polysiloxane treatment was performed, and then 100 parts by mass of carbon black (particle size: 0.03 μm) was added to 100 parts by mass of silica, and grinding treatment was performed to produce composite particles in which carbon black was fixed on the silica surface. .

(Production of Composite Particle 2-2 to Composite Particle 2-14)
Composite particles were produced in the same manner as composite particles 2-1, except that the inorganic particle species, polysiloxane species and their blending amounts, CB species and their blending amounts were changed as shown in Table 4.

(Preparation of composite particles 2-15)
Compounding Titanium oxide (particle size 0.3 μm, aspect ratio 2) 100 parts by weight Carbon black (particle size 0.03 μm) 110 parts by weight Titanate coupling agent 10 parts by weight Methanol 110 parts by weight The product was taken out and dried at 120 ° C. to prepare composite particles 2-15.

（実施例１４〜１８）
成形用原料の配合を表５のようにし、エンドレスベルトの周長を７５０ｍｍにした以外は実施例１と同様にエンドレスベルトを作製し、機械特性、電気特性の評価を実施例１と同様に行った。また、得られた電子写真エンドレスベルトを転写搬送ベルトとして図５に示す構成の電子写真装置（カラーレーザープリンター）に装着し、実施例１と同様に画像出力試験を行った。評価結果を表６に示す。

(Examples 14 to 18)
An endless belt was prepared in the same manner as in Example 1 except that the composition of the molding raw material was as shown in Table 5 and the circumference of the endless belt was changed to 750 mm, and the mechanical characteristics and electrical characteristics were evaluated in the same manner as in Example 1. It was. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 5 as a transfer conveyance belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 6.

(Examples 19 to 21)
An endless belt was prepared in the same manner as in Example 1 except that the composition of the raw materials for molding was as shown in Table 5 and the circumference of the endless belt was changed to 850 mm, and mechanical characteristics and electrical characteristics were evaluated in the same manner as in Example 1. It was. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 6 as an intermediate transfer belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 6.

(Examples 22 to 24)
An endless belt was produced in the same manner as in Example 1 except that the composition of the forming raw material was changed as shown in Table 5, and the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 6.

(Examples 25 to 28)
The endless belt was prepared in the same manner as in Example 1 except that the composition of the raw materials for molding, the kneading temperature and the molding temperature were as shown in Table 5, and the circumference of the endless belt was changed to 750 mm, and the mechanical and electrical characteristics were evaluated. Performed as in Example 1. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 5 as a transfer conveyance belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 6.

(Comparative Example 6)
An endless belt was prepared in the same manner as in Example 1 except that the composition of the molding raw material was as shown in Table 5 and the circumference of the endless belt was changed to 750 mm, and the mechanical characteristics and electrical characteristics were evaluated in the same manner as in Example 1. It was. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 5 as a transfer conveyance belt, and an image output test was conducted in the same manner as in Example 1. As shown in Table 7, since remarkable transfer unevenness due to the resistance variation of the belt was confirmed from the initial stage, the durability test was not performed.

(Comparative Example 7 to Comparative Example 9)
An endless belt was prepared in the same manner as in Example 1 except that the composition of the molding raw material was as shown in Table 5 and the circumference of the endless belt was changed to 750 mm, and the mechanical characteristics and electrical characteristics were evaluated in the same manner as in Example 1. It was. The obtained electrophotographic endless belt was mounted on an electrophotographic apparatus (color laser printer) having the configuration shown in FIG. 5 as a transfer conveyance belt, and an image output test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 6.

ガス分解法による複合粒子の作製
（複合粒子３−１の作製）
酸化チタン（粒径０．３μm、アスペクト比２）１００質量部を、メタン：水素＝５０：５０の混合ガス雰囲気下で、電気炉を用いて１１００℃で加熱焼成処理を行うことにより、表面に導電性物質であるカーボン析出層を有する複合粒子を作製した。

Production of composite particles by gas decomposition method (Production of composite particles 3-1)
By subjecting 100 parts by mass of titanium oxide (particle size: 0.3 μm, aspect ratio: 2) to 1100 ° C. using an electric furnace in a mixed gas atmosphere of methane: hydrogen = 50: 50, the surface is heated. Composite particles having a carbon deposition layer, which is a conductive substance, were produced.

(Production of composite particles 3-2 and composite particles 3-3)
A composite particle was produced in the same manner as the composite particle 3-1, except that the inorganic particle type and the hydrocarbon type were changed as shown in Table 7.

（実施例２９、実施例３０）
成形用原料の配合を表８のようにした以外は実施例１と同様にエンドレスベルトを作製し、実施例１と同様の評価を行った。評価結果を表９に示す。

(Example 29, Example 30)
An endless belt was produced in the same manner as in Example 1 except that the composition of the forming raw material was as shown in Table 8, and the same evaluation as in Example 1 was performed. Table 9 shows the evaluation results.

(Example 31 to Example 34)
An endless belt was produced in the same manner as in Example 1 except that the composition of the raw material for molding, kneading temperature, and molding temperature were as shown in Table 8, and the same evaluation as in Example 1 was performed. Table 9 shows the evaluation results.

(Comparative Example 10)
An endless belt was produced in the same manner as in Example 1 except that the composition of the forming raw material was changed as shown in Table 6, and the same evaluation as in Example 1 was performed. Table 9 shows the evaluation results.

It is a figure which shows an example of schematic structure of the apparatus which manufactures the electrophotographic endless belt which employ | adopted the inflation molding method. It is a figure which shows another example of schematic structure of the apparatus which employ | adopts an inflation molding method and manufactures the electrophotographic endless belt. It is a figure which shows an example of schematic structure of a biaxial extruder. 1 is a diagram illustrating an example of a schematic configuration of an intermediate transfer type color electrophotographic apparatus. FIG. 1 is a diagram illustrating an example of a schematic configuration of an in-line color electrophotographic apparatus using a transfer conveyance belt. It is a figure which shows another example of schematic structure of the in-line type color electrophotographic apparatus using an intermediate transfer belt. It is a figure which shows schematic structure of a bending test apparatus. It is a figure which shows schematic structure of the electrical property measuring apparatus of an endless belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Extruder 102 Hopper 103 Annular die 104 Gas introduction path 105 Gas 106 Molded body 107 Dimensional stability guide 108 Pinch roller 109 Cutter 201 Extruder 201
202 Hopper 301 Biaxial Extruder 302 Hopper 302 ′ Hopper 303 Strand Die 304 Strand 305 Water Tank 306 Strand Cutter 1 Electrophotographic Photoconductor 2 Axis 3 Primary Charging Member 4 Exposure Light (Image Exposure Light)
DESCRIPTION OF SYMBOLS 5 Developer carrier 6 Transfer member 7 Cleaning member 8 Fixing means 11 Intermediate transfer belt 12 Stretching roller 5Y First color developer carrier 5M Second color developer carrier 5C Third color developer carrier 5K 4th color developer carrying member 6p primary transfer member 6s secondary transfer member 7r charge imparting member 1Y first color electrophotographic photosensitive member 1M second color electrophotographic photosensitive member 1C third color electrophotographic photosensitive member 1K first 4 color electrophotographic photoreceptor 2Y axis 2M axis 2C axis 2K axis 3Y primary charging member for first color 3M primary charging member for second color 3C primary charging member for third color 3K primary charging member for fourth color 4Y exposure light 4M exposure light 4C exposure light 4K exposure light 6Y first color transfer member 6M second color transfer member 6C third color transfer member 6K fourth color transfer member 7Y first color cleaning member 7M second color cleaner Member 7C cleaning member for third color 7K cleaning member for fourth color 13 secondary transfer counter roller 14 transfer material transport belt 15 suction roller 16 separation charger 6pY primary transfer member for first color 6pM primary transfer member for second color 6pC Primary transfer member for third color 6pK Primary transfer member for fourth color 7 'Intermediate transfer belt cleaning member P Transfer material 500 Endless belt 501 Drive roller 502 Electrode roller 503 Feed roller 504 Tension roller HV High voltage power supply R Known resistor Rec. Recorder 701 Strip sample 702 Chuck 703 Chuck 704 Crank 705 Roller F Load

Claims (9)

The surface of the mother particle composed of inorganic particles having an aspect ratio of 10 or less contains composite particles coated with a conductive material mainly composed of carbon, and the content of the composite particles is 100 parts by mass of the thermoplastic resin. An endless belt made of a thermoplastic resin for electrophotography, characterized in that it is 5 to 100 parts by mass and has an electric resistance in the range of 1 × 10 ⁴ to 1 × 10 ¹² Ω.   2. The electroless thermoplastic resin endless belt according to claim 1, wherein the composite particles have a particle size of 0.01 to 10 [mu] m.   3. The electrophotography according to claim 1, wherein the composite particles have at least one selected from the group consisting of oxides, hydroxides, carbonates, and silicates. Endless belt made of thermoplastic resin.   The thermoplastic resin endless belt for electrophotography according to any one of claims 1 to 3, wherein the thermoplastic resin is a crystalline resin.   An electrophotographic apparatus comprising the electroless thermoplastic resin endless belt according to any one of claims 1 to 4. A method for producing an electrophotographic thermoplastic resin endless belt according to any one of claims 1 to 4, comprising at least the following steps. Production method.
(I) A step of obtaining composite particles by combining base particles composed of inorganic particles having a particle size of 0.5 to 10 μm and carbon black by a powder surface modification device (ii) The composite particles and thermoplasticity A step of obtaining a molding raw material by kneading the resin with a biaxial extruder (iii) A step of extruding the molding raw material with an extruder having an annular die A method for producing an electrophotographic thermoplastic resin endless belt according to any one of claims 1 to 4, comprising at least the following steps. Production method.
(I) A step of coating polysiloxane with mother particles composed of inorganic particles having a particle diameter of 0.01 to 10 μm on the surface of the inorganic particles using a grinding device. (Ii) Polysiloxane-coated inorganic particles and carbon Step of obtaining composite particles by compounding black using a grinding device (iii) Step of obtaining a molding raw material by kneading the composite particles and a thermoplastic resin with a biaxial extruder (iv) ) Extruding the raw material for molding with an extruder having an annular die A method for producing an electrophotographic thermoplastic resin endless belt according to any one of claims 1 to 4, comprising at least the following steps. Production method.
(I) A step of heating and firing inorganic particles in a hydrocarbon atmosphere or a mixed gas atmosphere of a hydrocarbon and a reducing gas and / or an inert gas (ii) Cooling the superheated inorganic particles in an inert gas atmosphere (Iii) A step of obtaining a molding raw material by kneading and kneading the composite particles and a thermoplastic resin with a biaxial extruder. (Iv) A step of extruding the forming raw material with an extruder having an annular die. In the step of kneading the composite particles and the thermoplastic resin with a biaxial extruder,
(I) a thermoplastic resin charging step of charging the thermoplastic resin into a twin screw extruder;
And (ii) a composite particle charging step of charging the composite particles into the twin screw extruder when the thermoplastic resin charged into the twin screw extruder is melted. A process for producing an endless belt made of thermoplastic resin for electrophotography according to any one of the above.

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