JP2008238552A - Manufacturing method of intermediate transfer belt for electronic photography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method, of an intermediate transfer belt for electronic photography, which enables sufficient inhibiting of the interference by a reflected light on an interface of a surface layer/a belt base material and a reflected light on the surface of the surface layer, and adequate securing of an absolute amount of light of the reflected light. <P>SOLUTION: This manufacturing method is to manufacture the intermediate transfer belt for electronic photography which has a belt base material molded of a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant and polyetherester amide as a conducting material, and a surface layer formed on the belt base material. In addition, the manufacturing method comprises a process to mold a preform 104 from the thermoplastic resin composition, a process to mold a bottle-like molded object from the preform, a process to prepare the belt base material from the bottle-like molded object, and a process to form the surface layer on the belt base material surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electrophotographic intermediate transfer belt (such as an intermediate transfer belt or a transfer material conveying belt) used in an electrophotographic apparatus that employs an image forming system such as an electrophotographic system or an electrostatic recording system.

  An electrophotographic apparatus develops an electrostatic latent image formed on the surface of an electrophotographic photosensitive member with toner of a developing device, and forms an image by transferring the developed image (toner image) onto a transfer material such as paper. This is an image forming apparatus that employs this method.

  In recent years, there has been an increasing demand for electrophotographic apparatuses (color electrophotographic apparatuses) capable of outputting color images, such as color copiers and color printers. A color image is formed by transferring a plurality of color toner images onto a transfer material. For this reason, it is necessary to align the positions of the toner images of a plurality of colors and transfer them onto the transfer material.

Examples of a method for transferring a multi-color toner image onto a transfer material include the following.
One is the provision of an electrophotographic photoconductor for each color, and the toner images of each color formed on the surface of each electrophotographic photoconductor are sequentially superimposed and transferred onto a transfer material carried and conveyed by a transfer material conveyance belt. It is a method to do. In addition, an electrophotographic photoreceptor is provided for each color, and the toner images of each color formed on the surface of each electrophotographic photoreceptor are sequentially superimposed on the surface of the intermediate transfer belt for primary transfer, and the superimposed toner images are transferred. A method of performing secondary transfer collectively on the material can be mentioned. Further, a developing device for each color is provided around one electrophotographic photosensitive member, a toner image of the first color is formed on the surface of the electrophotographic photosensitive member, and this is primarily transferred onto the surface of the intermediate transfer belt. Can be listed as many times as possible. In this type of electrophotographic apparatus, a toner image in which the respective colors are superimposed is formed on the surface of the intermediate transfer belt, and then this is secondarily transferred onto a transfer material all at once.

  A color electrophotographic apparatus employing the above-described method forms a mark on the surface of a transfer member (transfer material conveyance belt or intermediate transfer belt) in order to perform registration alignment (position alignment of the image leading edge) between the colors. Many use a mechanism that detects the reflected light from the mark.

  The mark may be formed on the surface of the transfer member in advance on the transfer member, or the mark may be formed with toner. Also, the first transferred image can be used as a mark.

  For example, in Patent Document 1, a mark is formed with toner on the surface of an intermediate transfer member, the toner density of the mark is detected using an optical toner density sensor, and the image density is controlled based on the detection result. Technology is disclosed.

  Further, a surface layer is often provided on the surface of the transfer member for suppressing scratches caused by magnetic substances such as ferrite contained in the toner and inorganic fine particles such as silica. Generally as this surface layer, the layer which has a volume resistivity (high resistance) higher than the base material layer located under this surface layer is provided.

For example, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6 disclose a transfer member having a multilayer structure. Specifically, in Patent Document 2, a conductive layer and a surface layer are formed in this order on a substrate, and the volume resistivity of the conductive layer is lower than the volume resistivity of the substrate and the surface layer. An intermediate transfer belt of 10 ⁷ Ω · cm or less is described. In Patent Document 3, the ratio (E1 / E2) between the relative dielectric constant (E1) of the surface layer of the transfer member and the relative dielectric constant (E2) of the electrophotographic photosensitive member is 0.02 ≦ (E1 / E2). A technique for making ≦ 0.7 is disclosed. Patent Document 4 discloses an intermediate transfer belt that satisfies the relationship E1> E2 where the Young's modulus of the surface layer is E1 and the Young's modulus of the substrate is E2. Further, Patent Document 5 and Patent Document 6 are provided with a reinforcing / releasing layer formed of fluororubber in which a fluororesin is dispersed above and below an elastic layer made of polyurethane rubber, and a surface treatment layer on the surface thereof. A belt-shaped transfer member having a total of four layers provided is disclosed.

  However, when a transfer member having a multilayer structure is used, if the toner position detection and density detection are optically performed with reference to the mark formed on the surface of the transfer member, the accuracy of toner density detection and position detection is reduced. There is. This is because, when the transfer member is a laminate of a surface layer and a base material, incident light transmitted through the surface layer is reflected at the surface layer-base material interface (base material surface), and this reflected light is reflected on the surface layer surface ( This is because it interferes with another reflected light reflected by the transfer member surface. It is considered that slight layer thickness unevenness of the surface layer causes the interference light to be reflected or prevented from being reflected and the accuracy of toner density detection and position detection to be reduced.

  Patent Document 7 discloses a display surface in which the outermost surface layer is formed of a material having a lower refractive index than that of the base layer, and the reflection on the surface layer surface is eliminated by setting the transmittance to 100% and the reflectance to 0%. An antireflective film is disclosed.

  In Patent Document 8, the refractive index of the charge transport layer, the charge generation layer, and the conductive basic surface of the multilayer photoreceptor is made substantially the same, and the reflected light of the light irradiated by the coherent light source at each layer interface is 0. A technique for preventing reflected light interference of each layer by making the content of% is disclosed.

  However, the techniques disclosed in Patent Document 7 and Patent Document 8 cannot be diverted to a transfer member that optically detects toner concentration and position using reflected light on the surface layer surface (transfer member surface). This is difficult because the absolute amount of reflected light is reduced.

JP 2004-0669805 A JP 2000-056585 A Japanese Patent Laid-Open No. 08-278708 JP 2000-330390 A Japanese Patent Laid-Open No. 11-161036 US Pat. No. 6,094,558 JP 07-287102 A JP 04-229871 A

  The present invention has been made in view of the above prior art, and interference between reflected light on the surface layer-belt base material interface and reflected light on the surface layer surface is sufficiently suppressed, and the absolute value of the reflected light is not limited. An object of the present invention is to provide a method for producing an electrophotographic intermediate transfer belt in which a sufficient amount of light is secured.

  The present invention that has solved the above problems is a belt base material molded from a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant, and a polyether ester amide as a conductive agent, and on the belt base material. A process for producing an electrophotographic intermediate transfer belt having a formed surface layer, the step of molding a preform from the thermoplastic resin composition, the preform being preheated and preheated in a mold A preform is stretched using a stretching rod that moves at a predetermined speed, and a gas is flown into the preform stretched by the stretching rod to swell the preform in the mold to form a bottle-shaped molded product. A step of forming, a step of preparing a belt base material by cutting the mouth side portion and the bottom side portion of the bottle-shaped molded product, a coating liquid is applied to the surface of the belt base material, and this is dried and cured And forming the surface layer DOO is a manufacturing method of the electrophotographic intermediate transfer belt, characterized in that it comprises a.

  According to the present invention, the interference between the reflected light on the surface layer-belt base material interface and the reflected light on the surface layer surface is sufficiently suppressed, and the absolute light quantity of the reflected light is sufficiently secured. An intermediate transfer belt can be manufactured and provided.

The present invention relates to a belt base material molded from a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant, and a polyether ester amide as a conductive agent, and a surface layer formed on the belt base material The present invention relates to a method for producing an electrophotographic intermediate transfer belt comprising: This method of manufacturing an electrophotographic intermediate transfer belt includes the following steps.
(A) A step of molding a preform from the thermoplastic resin composition (sometimes referred to as a preform molding step (a)).
(B) A step of preheating the preform (sometimes referred to as a preform preheating step (b)).
(B ′) The preheated preform is stretched in a mold by using a stretching rod that moves at a predetermined speed, and a gas is introduced into the preform stretched by the stretching rod in the mold. A process of forming a bottle-shaped product by inflating a preform. This step may be referred to as a bottle-shaped molded product forming step (b ′).
(C) A step of preparing a belt base material by cutting the mouth side portion and the bottom side portion of the bottle-shaped molded product (sometimes referred to as a belt base material preparation step (c)).
(D) A step of applying a coating liquid to the surface of the belt base material, drying and curing the coating solution to form a surface layer (sometimes referred to as a surface layer forming step (d)).

  FIG. 1 shows a cross-sectional configuration of an electrophotographic intermediate transfer belt manufactured by the above-described method for manufacturing an electrophotographic intermediate transfer belt of the present invention. As shown in FIG. 1, the electrophotographic intermediate transfer belt produced according to the present invention has a belt substrate 15 and a surface layer 16 formed on the belt substrate. The belt base material 15 is molded from a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant, and a polyether ester amide as a conductive agent. On the other hand, the surface layer 16 is formed by applying a coating liquid to the surface of the belt base material 15 and drying and curing it.

  When the smoothness of the surface of the belt base material is high, generally, a lot of reflected light is generated at the surface layer-belt base material interface, and interference with the reflected light on the surface layer surface occurs. For this reason, slight layer thickness unevenness of the surface layer causes interference light to be reflected or prevented from being reflected, and the accuracy of toner density detection and position detection is lowered. Therefore, in the present invention, a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant, and a polyether ester amide as a conductive agent is used as the thermoplastic resin composition used for preparing the belt base material.

  First, the thermoplastic resin composition used in the present invention will be described. The thermoplastic resin composition contains a thermoplastic resin, a solid lubricant, and polyether ester amide as a conductive agent.

  Examples of the thermoplastic resin that can be used in the present invention include polycarbonate, polyvinylidene fluoride (PVDF), polyethylene, polypropylene, polymethylpentene-1, polystyrene, polyamide, polysulfone, polyarylate, polyethylene naphthalate (PEN), Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate / terephthalate copolymer, polyphenylene sulfide, polyether sulfone, polyether nitrile, thermoplastic polyimide, polyether ether ketone, thermotropic liquid crystal polymer, polyamic acid And other thermoplastic resins. These can be used alone or in admixture of two or more.

  Among these thermoplastic resins, particularly preferred resins include polyester resins and fluorine resins in that the physical properties of the electrophotographic intermediate transfer belt are satisfied.

  More preferable resins for the polyester resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene naphthalate / terephthalate copolymer, and mixtures thereof. Since these thermoplastic resins are suitable for stretch blow molding, it is preferable when a belt base material is prepared by stretch blow molding.

  In the present invention, it is preferable to use polyether ester amide (PEEA) as the conductive material. In the present invention, when polyether ester amide is used as the conductive material, resistance uniformity can be obtained and deterioration of brittleness can be suppressed. Examples of the polyether ester amide used in the present invention include copolymers comprising polyamide block units such as nylon 6, nylon 66, nylon 11 and nylon 12, and polyether ester units. In addition, for example, lactam (for example, caprolactam, lauryl lactam) or aminocarboxylic acid salt, polyethylene glycol and dicarboxylic acid (for example, terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. ) And the like. The polyether ester amide used in the present invention can be produced, for example, by a known polymerization method such as melt polymerization. Moreover, 1 type may be used for the polyetheresteramide used in this invention, and it may use it in combination of 2 or more type.

  The addition amount of these polyetheresteramides is usually preferably 10% by mass or more, and more preferably 15% by mass or more with respect to the total mass of the thermoplastic resin composition. Moreover, the addition amount of the polyether ester amide is usually preferably 30% by mass or less and more preferably 23% by mass or less with respect to the total mass of the thermoplastic resin composition. When the addition amount of the polyether ester amide is 10% by mass or more, a sufficient conductivity control effect can be obtained. Moreover, when it is 30 mass% or less, what has sufficient tensile elasticity modulus as an intermediate transfer belt for electrophotography is obtained, and it is preferable.

  In the present invention, a conductive material other than polyetheresteramide may be added to the thermoplastic resin composition. Examples of such conductive materials include tetraalkylammonium salts, trialkylbenzyls, ammonium salts, sulfonates, alkyl sulfates, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty alcohol esters, alkylbetaines. And lithium perchlorate. In particular, potassium perfluorobutanesulfonate that can achieve both conductivity and bleed property is particularly preferable.

  Examples of the solid lubricant that can be used in the present invention include silicone powder, boron nitride, graphite, molybdenum disulfide, and the like. Of these, silicone powder is preferred. The addition amount of the solid lubricant is usually preferably 1% by mass or more and 5% by mass or less, and more preferably 1% by mass or more and 3% by mass or less with respect to the total mass of the thermoplastic resin composition. When the amount of solid lubricant added is 1% by mass or more, in the process of forming a bottle-shaped product by injecting gas into the preform and expanding the preform in the mold, the inner surface of the mold and the preform By improving the slipperiness of the outer surface, it is easy to obtain the dimensional accuracy of the molded bottle. Moreover, when the addition amount of a solid lubricant shall be 5 mass% or less, it can suppress that thermoplastic resin itself becomes weak by solid lubricant addition.

  In the present invention, a filler may be added to the thermoplastic resin composition. The filler that can be added is not particularly limited, and examples thereof include inorganic fillers. Examples of inorganic fillers include mica, glass fiber, glass sphere, cryolite, zinc oxide, titanium oxide, calcium carbonate, clays, talc, silica, wollastonite, zeolite, diatomaceous earth, silica sand, and pumice powder. , Slate powder, alumina, alumina white, aluminum sulfate, barium sulfate, lithopone, calcium sulfate, molybdenum disulfide, graphite, aluminum doped zinc oxide, tin oxide coated titanium oxide, tin oxide, tin oxide coated barium sulfate, potassium titanate, Examples thereof include aluminum metal powder and nickel metal powder, but are not limited thereto.

  Organic fillers include tetrafluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin, and these Resin particles made of the above copolymer, rubber powder made of silicone compounds such as fluorocarbon, silicone resin, silicone rubber, ebonite powder, shellac, wood powder, coconut and coconut shell powder, cork powder, cellulose powder, wood One or more kinds are appropriately selected from pulp and the like. Moreover, it is not necessarily limited to these.

  Carbon black may be used for coloring. The amount of carbon black added is preferably 0.5% by mass or more and 3% by mass or less with respect to the total mass of the thermoplastic resin composition. When the content is 0.5% by mass or more and 3% by mass or less, a sufficient coloring effect is obtained, which is preferable.

  In addition, a resin compatibilizer may be added to the thermoplastic resin composition. Examples of the resin compatibilizer that can be added include, but are not limited to, epoxy acrylic.

Preferred thermoplastic resin compositions that can be used in the present invention include, for example, those having the following composition.
PEN resin 70% by mass or more and 82% by mass or less Carbon black 1% or more and 3% or less Polyetheresteramide 15% by mass or more and 23% by mass or less Silicon powder 1% by mass or more and 5% by mass or less Epoxy acrylic 0% by mass or more 5% by mass or less

  The thermoplastic resin composition in the present invention can be produced by uniformly mixing the thermoplastic resin, the solid lubricant, the polyether ester amide used as a conductive material, and other additives. There is no particular limitation on the mixing method, and it can be prepared by mixing with a single screw extruder, twin screw kneading extruder, Banbury mixer, roll, Brabender, plastograph, kneader, etc. It is particularly preferable to use after mixing and pelletizing.

Next, a method for preparing a belt base material according to the present invention will be described with reference to FIGS.
In the method for preparing the belt base material, first, in the preform molding step (a), a molded product called a preform is molded from the thermoplastic resin composition. The shape of the preform is not particularly limited as long as a belt base material having a uniform thickness can be obtained, but a shape having a test tube shape is usually preferable. Also, the molding method is not particularly limited, but it is preferable to use injection molding that is easy to stabilize the shape. For example, as shown in FIG. 2, the pelletized thermoplastic resin composition is heated and melted by an injection molding apparatus 101 and injected into, for example, a cavity of an injection mold including a cavity mold 102 and a core mold 103. The preform 104 may be formed. In FIG. 2, 105 is the bottom of the preform 104, and 106 is the preform mouth.

Next, for example, stretch blow is performed by the method shown in FIG. First, in the preform preheating step (b), the preform 104 is placed in the preheating furnace 107 and preheated to the stretching temperature. Next, in the bottle-shaped molded product forming step (b ′), the preheated preform 104 is put into a blow mold 108, and the preform is stretched in the vertical direction using a stretching rod 109 that moves at a predetermined speed. . This stretching is called primary stretching. After this primary stretching, a gas 110 is caused to flow into the stretched preform from the preform mouth portion 106 and the preform is expanded in the lateral direction to form a bottle-shaped molded product 112. This is called secondary stretching. The bottle-shaped molded product 112 is obtained by performing these primary stretching and secondary stretching.
Since the bottle-shaped molded product 112 is stretched in both the vertical and horizontal directions, the molded product has a high strength.

  Next, in the belt base material preparation step (c), the mouth side portion and the bottom side portion of the bottle-shaped molded product are removed by cutting as shown in FIG. . The method for cutting the mouth side portion and the bottom side portion of the bottle-shaped molded product is not particularly limited. For example, an ultrasonic cutter may be used.

  The stretch blow mold used for the preparation of the belt base material in the present invention is preferably a transversely divided cylindrical mold. When a vertically-divided cylindrical mold of the type in which the cylindrical body portion shown in FIG. 5 is divided vertically is used, the image transfer portion as shown in FIG. And a step is generated on the parting line. For this reason, horizontal stripes appear in the image, and when the belt is rotated, vibration may occur at the level difference of the parting portion, and banding may occur.

  After the preform is expanded to form the bottle-shaped molded product 112, the bottle-shaped molded product 112 is removed from the blow mold. The inner surface of the blow mold that contacts the bottle-shaped molded product is preferably a smooth surface in order to achieve good mold separation between the bottle-shaped molded product and the blow mold. Specifically, the value of the surface roughness Rzjis (JIS B0601-2001) on the surface of the belt base material prepared by the above method (the surface of the belt base material in contact with the inner surface of the stretch blow mold) is 0.1 μm or less. It is preferable that

  Next, a surface layer is formed in the surface layer formation step (d) on the surface of the belt substrate prepared in the belt substrate preparation step. In the surface layer forming step (d), a coating liquid is applied to the surface of the belt base material, and this is dried and cured to form a surface layer.

  The coating liquid used for forming the surface layer is used as a binder component from the viewpoint of increasing the hardness of the surface layer of the electrophotographic intermediate transfer belt and improving the durability (wear resistance). It is preferable to include a curable material that is cured by irradiation with a line or the like. Among the curable materials, examples of the organic material include curable resins such as melamine resin, urethane resin, alkyd resin, acrylic resin, and fluorine-containing curable resin. Examples of the inorganic material include an alkoxylane / alkoxyzirconium-based material and a silicate-based material. Examples of the organic / inorganic hybrid material include inorganic fine particle acrylic radical materials, inorganic fine particle dispersed organic polymer materials, inorganic fine particle dispersed organoalkoxysilane materials, acrylic silicon materials, and organoalkoxysilane materials.

  Among these, from the viewpoint of the wear resistance of the surface layer, a curable resin is preferable as the binder component. Among the curable resins, an acrylic resin is preferable, and among the acrylic resins, dipentaerythritol hexaacrylate is preferable. Dipentaerythritol hexaacrylate is available, for example, as Desolite Z7501 (trade name, manufactured by JSR Corporation, acrylic ultraviolet curable hard coat material).

  The surface layer is usually a layer having a smaller volume resistivity (lower resistance) than that of the belt base material. In order to make the surface layer have a low volume resistivity, the above-mentioned coating solution is made of a conductive material. This can be achieved by adding a filler.

  Examples of the conductive filler include particulate, fibrous or flaky carbon conductive fillers such as carbon black, PAN-based carbon fiber and expanded graphite pulverized product, silver, nickel, copper, zinc, aluminum, and stainless steel. Particulate, fibrous or flaky metallic conductive fillers such as iron and particulate metallic oxide conductive particles such as antimony-doped tin oxide, tin-doped indium oxide and aluminum-doped zinc oxide. Among these, particulate metal oxide conductive particles are preferable in that the addition amount is small and a surface layer having excellent surface smoothness can be obtained.

  The method for preparing the coating liquid is not particularly limited. For example, the components such as the binder component and the conductive filler are mixed in a solvent, and dissolved or dispersed using a device such as a homogenizer or a bead mill. That's fine. Examples of the solvent include isopropyl alcohol, methyl ethyl ketone, and isobutanol.

  Moreover, there is no restriction | limiting in particular in the coating method to a belt base-material surface, What is necessary is just to employ | adopt the coating method suitable for this invention. For example, methods such as coating using a roll coater, spraying, and dip coating can be used.

  There is no particular limitation on the drying method and curing method of the coating solution applied on the belt substrate, and it is suitable for drying and curing the binder component contained in the coating solution applied to form the surface layer. Any drying method or curing method may be employed. As a drying method suitable for the present invention, for example, a hot air electric furnace or the like can be used as a means for eliminating residual solvent before curing. Further, as a curing method suitable for the present invention, for example, when the binder component is thermosetting, it may be cured by heating to a temperature suitable for curing the binder component. Moreover, what is necessary is just to irradiate an ultraviolet-ray, if it contains an ultraviolet curing binder component.

  The abrasion resistance of the surface layer formed by the above method is preferably such that ΔHaze after the test is 10% or less in the ASTM-D-1175 Taber abrasion test (wear wheel CS-10F, load 500 g, 500 rotations). When ΔHaze after the surface layer test is 10% or less, when the belt is used as an intermediate transfer belt for electrophotography, the belt surface has high wear resistance. There is no change. Thereby, it is possible to stably measure items detected by reflected light from the belt surface such as toner density over a long period of time.

  The layer thickness of the surface layer is usually preferably 0.5 μm or more and 5 μm or less. When the thickness of the surface layer is 0.5 μm or more, the surface layer is not scraped and the belt base material is not exposed when repeatedly used, and the reflectance of the surface of the electrophotographic intermediate transfer belt changes. There is no risk of problems. On the other hand, when the thickness of the surface layer is 5 μm or less, it is possible to prevent the surface layer from cracking when used repeatedly due to the difference in flexibility between the surface layer and the belt base material.

Furthermore, it is usually preferable to adjust the volume resistance value of the belt, and the range of the volume resistivity at which a good image can be obtained is usually 10 ⁶ Ω · cm or more and 10 ¹³ Ω · cm or less when 100 V is applied. When the volume resistivity is less than 10 ⁶ Ω · cm, the volume resistivity is low, so that a sufficient transfer electric field may not be obtained, and image omission and roughness may occur. On the other hand, if the volume resistivity is higher than 10 ¹⁴ Ω · cm, it is necessary to increase the transfer voltage, which may increase the size and cost of the power supply. However, depending on the transfer process, good transfer may be possible even outside this range, so the volume resistivity of the belt is not necessarily limited to the above range.

Next, the usage form of the electrophotographic intermediate transfer belt produced by the method for producing the electrophotographic intermediate transfer belt of the present invention will be described.
FIG. 6 is a schematic sectional view of an electrophotographic apparatus using the electrophotographic intermediate transfer belt of the present invention as an intermediate transfer belt.

  In FIG. 6, a drum-shaped electrophotographic photosensitive member (hereinafter also referred to as “photosensitive drum”) 1 is rotationally driven in a direction of an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive drum 1 is charged to a predetermined polarity and a predetermined potential by the primary charger 2, and then receives exposure light 3 from an image exposure unit (not shown). S1 is a bias power source for the primary charger. In this manner, an electrostatic latent image corresponding to the first color component image (for example, yellow toner image) of the target color image is formed on the photosensitive drum 1.

  Next, the electrostatic latent image is developed into a yellow toner image which is the first color by the first developing device 41 (yellow Y developing device). At this time, the second, third, and fourth developing units, that is, the magenta M developing unit 42, the cyan C developing unit 43, and the black BK developing unit 44 are not operated and do not act on the photosensitive drum 1. Therefore, the yellow toner image of the first color is not affected by the magenta M developing unit 42, the cyan C developing unit 43, and the black BK developing unit 44.

  The intermediate transfer belt 7 is stretched around the roller groups 64, 65 and 66, is disposed so as to contact the photosensitive drum 1, and is rotationally driven in the direction of arrow B at the same peripheral speed as the photosensitive drum 1. Then, the yellow component image of the first color formed on the photosensitive drum 1 is primarily transferred onto the surface of the intermediate transfer belt 7 in the process of passing through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 7.

  The primary transfer is performed by an electric field formed by a primary transfer bias (polarity opposite to the toner) applied from the bias power source S4 to the primary transfer roller 62.

  The yellow toner remaining on the photosensitive drum 1 without being primarily transferred is cleaned by the cleaning device 13. Similarly, a magenta toner image of the second color, a cyan toner image of the third color, and a black toner image of the fourth color are sequentially superimposed and transferred onto the intermediate transfer belt, and a composite color toner image corresponding to the target full-color image. Is formed.

  The composite full color toner image formed on the intermediate transfer belt 7 is secondarily transferred to the transfer material P. That is, the transfer material P passes through the transfer material supply roller 10 and the transfer material guide 11 from a cassette (not shown) and is supplied to the nip portion between the intermediate transfer belt 7 and the secondary transfer roller 63. At the same time, the secondary transfer bias is applied from the bias power source S5 to the secondary transfer roller 63, whereby the composite color toner image on the intermediate transfer belt 7 is secondarily transferred to the transfer material P. The transfer material P onto which the composite full color toner image has been transferred is introduced into the fixing device 14, and the composite color toner image is fixed to the transfer material P.

  In addition, the toner remaining on the intermediate transfer belt 7 without being transferred to the transfer material P during the secondary transfer is charged by the charging device 8 and is transferred to the photosensitive drum 1 at the nip portion between the photosensitive drum 1 and the intermediate transfer belt 7. It is collected by the cleaning device 13.

  FIG. 7 is a schematic cross-sectional view of an example of an electrophotographic apparatus of a type in which four photosensitive drums 1 for forming toner images of respective colors are mounted and each photosensitive drum is disposed so as to contact the intermediate transfer belt 7. is there. The intermediate transfer belt for electrophotography in the present invention is used as the intermediate transfer belt 7.

  8 and 9 are schematic cross-sectional views of an electrophotographic apparatus using the electrophotographic intermediate transfer belt according to the present invention as the transfer material conveying belt 12. FIG.

  In FIG. 8, the transfer material P is supplied from a cassette (not shown) through the transfer material supply roller 10 and the transfer material guide 11 onto the transfer material conveyance belt 12. The transfer material P is carried and conveyed by the transfer material conveyance belt 12 and passes through the nip portion between the photosensitive drum 1 and the transfer material conveyance belt 12, and the toner image formed on the photosensitive drum 1 at that time is transferred. Transferred onto the transfer material P. S3 is a bias power source. The transfer material P on which the four color toner images are superimposed and transferred and a composite color toner image corresponding to the target full color image is formed is introduced into the fixing device 14, and the composite color toner image is fixed to the transfer material P.

  In FIG. 9, four photosensitive drums 1 for forming toner images of respective colors are mounted, and each photosensitive drum is arranged so as to form a nip with the transfer material conveyance belt 12. The transfer material P is supplied from a cassette (not shown) through the transfer material supply roller 10 and the transfer material guide 11 onto the transfer material conveyance belt 12. The transfer material P is carried on the transfer material conveyance belt 12 and sequentially conveyed, and passes through the nip between each photosensitive drum 1 and the transfer material conveyance belt. At that time, the toner images of the respective colors formed on the photosensitive drum. Is superimposed and transferred onto the transfer material P. 6 is a bias applying means, and S3 is its bias power source. The transfer material P on which the four color toner images are superimposed and transferred and a composite color toner image corresponding to the target full color image is formed is introduced into the fixing device 14, and the composite full color toner image is fixed to the transfer material P.

Hereinafter, the present invention will be described in detail with reference to examples.
In this example, a cylindrical endless belt (endless belt) having a cross-sectional structure shown in FIG. 7 was manufactured as an intermediate transfer belt. The intermediate transfer belt having the configuration shown in FIG. 7 is formed by laminating a surface layer 16 on a belt substrate 15 as shown in FIG.

  The bottle-shaped molded product, belt base material and intermediate transfer belt produced in this example were evaluated by the following methods.

(Evaluation of surface roughness Rzjis of bottle-shaped molded product and belt substrate)
According to JIS B0601-2001, surface roughness meter SE-3500 (trade name) manufactured by Kosaka Laboratory Ltd., arithmetic average roughness (Rzjis) for 3 points in the axial direction × 3 points in the circumferential direction = total of 9 points. Was measured and the average value was taken. The measurement was performed under the conditions of a cutoff of 0.8 mm, a measurement distance of 8.0 mm, and a feed rate of 0.5 mm / s.

(Evaluation of appearance of bottle-shaped molded product and belt base material)
The appearance was evaluated by visually checking the swell.

(Evaluation of regular reflectance of intermediate transfer belt)
The regular reflectance and reflectance of the obtained transfer belt were measured using a photosensor (spectrophotometer U-4000 (trade name), manufactured by Hitachi, Ltd.). A near infrared light having a wavelength of 950 nm from a light emitting element such as a light emitting diode is applied to the intermediate transfer belt at an incident angle of 12 °, and the reflected light at a reflection angle of 12 ° is received by a light receiving element such as a photodiode and output. The intensity of reflected light was measured from (V). The percentage of reflected light with respect to the intensity of irradiated light was defined as regular reflectance. The average value of 10 points measured at the central portion of the intermediate transfer belt in the belt width direction was defined as regular reflectance.

(Evaluation of variation in reflectance at each position of the intermediate transfer belt)
In addition, the variation in reflectance at each position in the intermediate transfer belt is determined by the intermediate transfer at an incident angle of 12 ° from a position 30 mm away from the belt surface using near infrared light having the same wavelength as described above using the same photosensor. The belt was irradiated and the specular reflection intensity at a reflection angle of 12 ° was measured. The intensity of reflected light at 8 points is measured every 16 mm pitch in the circumferential direction of the intermediate transfer belt, and the average value of the measured 8 points is used as the center value, and the percentage of the maximum deviation from the center value with respect to the average value varies. The amount.

(Evaluation of color shift of output image)
After adhering rubber rib members for preventing meandering to both ends in the width direction of the intermediate transfer belt obtained in this example, this was attached to a color electrophotographic apparatus (color laser beam printer, LBP-5900) manufactured by Canon Inc. (Product name)) as an intermediate transfer belt,
Dark part potential (non-image part potential): -700 V
Bright part potential (image part potential): -150V
Developer: Non-magnetic one-component toner (all 4 colors)
Transfer voltage: 1.5 kV
Process speed: 122mm / s
The image was output by, and the color misregistration amount (μm) of each color of the image was visually measured using a microscope.

Example 1
[Preparation of belt substrate]
-PEN (TN-8065S manufactured by Teijin Chemicals) 74% by mass
-PEEA (Fuji Kasei Kogyo TPAE-10) 21% by mass
・ Solid lubricant (silicone powder) 3% by mass
(Toray Dow Corning Silicone DC4-7081)
Carbon black (CB) (Mitsubishi Chemical MA-100) 2% by mass

The above materials were melted and kneaded with a twin-screw extruder to prepare pellets. This was made into the thermoplastic resin composition for belt base material preparation, and the preform was produced with the injection molding machine using this. That is, after the thermoplastic resin composition is completely melted at 290 ° C., metering / compression / injection is performed by an injection screw, and then injected into a molding die. After holding the pressure, a cooling step in the die Then, the molded product was taken out to obtain a preform. The obtained preform was uniformly preheated to 145 ° C. with a halogen heater and transferred to a stretch blow step. Here, the temperature of the preform was measured with a radiation thermometer 5 seconds before the blow mold was tightened. When the length in the longitudinal direction of the preform is 100%, the measurement location is 40% from the preform center toward the preform mouth and 40% from the preform center toward the preform bottom. It was. The average temperature (° C.) of the preform measured at these points (sometimes referred to as preform temperature (° C.)) was 145 ° C. Next, stretch blow molding was performed at a preform temperature of 145 ° C. to form a bottle-shaped molded product. After molding, the blow mold was opened to obtain a bottle-shaped molded product. In the visual inspection of the obtained bottle-shaped molded product, no swell was observed in the bottle-shaped molded product.
Thereafter, the mouth and bottom of the bottle-shaped molded product were cut with an ultrasonic cutter, and a belt base material having a width of 280 mm was cut out. About the obtained belt base material, the surface roughness Rzjis was evaluated by the said method. The obtained belt base material had a very small Rzjis value, which was an unmeasurable level.

[Preparation of coating solution for surface layer formation]
Acrylic ultraviolet curable hard coat containing Celnax (trade name, manufactured by Nissan Chemical Industries, Ltd., isopropanol sol of zinc antimonate) and dipentaerythritol hexaacrylate as conductive particles in a container shielded from ultraviolet rays After mixing with OPSTAR (trade name, manufactured by JSR Corporation) as a material, methyl isobutyl ketone was added to obtain a coating solution for forming a surface layer. The coating liquid contains 12.6% by mass of Cellux, 50% by mass of OPSTAR, and 37.4% by mass of methyl isobutyl ketone based on the mass of the coating liquid.

[Preparation of intermediate transfer belt with surface layer]
The above coating solution was dip-coated on the belt base material, and a surface layer having a thickness of 1 μm was formed by irradiating it with ultraviolet rays to obtain an intermediate transfer belt.
The regular reflectance and reflectance variation of the obtained intermediate transfer belt and the color shift amount of the output image when this intermediate transfer belt was used were evaluated by the above method. The regular transfer rate of the intermediate transfer belt of this example was 4.45%, and the variation in reflectivity was suppressed to 3.6% within one cycle of the intermediate transfer belt. The color shift amount of the output image was 80 μm. The obtained results are summarized in Table 1.

(Example 2)
An intermediate transfer belt was produced in the same manner as in Example 1 except that the thickness of the surface layer was 5 μm, and the intermediate transfer belt was evaluated in the same manner as in Example 1.
The intermediate transfer belt of this example is less affected by the surface of the belt base material by increasing the thickness of the surface layer, and the surface layer has improved surface smoothness, so that the regular reflectance is 4.90. % Became large. Also, the variation in reflectance was suppressed to 2.4% within one cycle of the intermediate transfer belt because the absolute value of the reflectance was large and noise was reduced. The color shift amount of the output image was 30 μm. The obtained results are summarized in Table 1.

(Comparative Example 1)
An intermediate transfer belt was prepared and evaluated in the same manner as in Example 1 except that epoxy acrylic was added as a resin compatibilizing agent in place of the solid lubricant silicone powder. The stretch blow conditions of this comparative example are the same as those of Example 1 except that the preform temperature of 145 ° C. in Example 1 is changed to 160 ° C.
In the case of this comparative example, unlike Example 1, the thermoplastic resin composition used for the preparation of the belt substrate does not contain a solid lubricant. For this reason, the optimization of the combination with the coating material for forming the surface layer is insufficient, and the interference between the reflected light at the surface layer-belt base material interface and the reflected light at the surface layer surface is large. As a result, the regular reflectance was 4.40% and the variation in reflectance was 9.4%. The color shift amount of the output image was 300 μm. When the color misregistration amount exceeds 150 μm, the color misregistration can be discriminated visually. For this reason, in the case of this comparative example, the image quality of the output image was clearly inferior to that of the example. The obtained results are summarized in Table 1.

(Comparative Example 2)
A belt substrate was prepared in the same manner as in Example 1 except that the surface layer was not formed on the belt substrate, and this belt substrate was used as an intermediate transfer belt and evaluated in the same manner as in Example 1.
The intermediate transfer belt of this comparative example did not have a surface layer, so that sufficient regular reflectance was not obtained, and the regular reflectance was 1.90%. For this reason, the specularly reflected light is buried in noise, and the variation in reflectance is 4.0% within one belt period. In addition, the amount of specular reflection light was small and the sensor could not detect, so that a sufficient image could not be output and the color misregistration amount could not be measured. The obtained results are summarized in Table 1.

1 is a schematic cross-sectional view of an electrophotographic intermediate transfer belt in the present invention. It is the schematic of an example of the injection molding apparatus which can be used for this invention. It is the schematic of an example of the stretch blow molding apparatus which can be used for this invention. It is explanatory drawing which shows the cut position of the bottle-shaped molded product in this invention. It is explanatory drawing of an example of a vertically divided cylindrical metal mold | die. 1 is a schematic cross-sectional view of an example of an electrophotographic apparatus having an intermediate transfer belt manufactured according to the present invention. 1 is a schematic cross-sectional view of an example of an electrophotographic apparatus having an intermediate transfer belt manufactured according to the present invention. 1 is a schematic cross-sectional view of an example of an electrophotographic apparatus using an intermediate transfer belt manufactured according to the present invention as a transfer material conveying belt. 1 is a schematic cross-sectional view of an example of an electrophotographic apparatus using an intermediate transfer belt manufactured according to the present invention as a transfer material conveying belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Injection molding apparatus 102 Cavity type | mold 103 Core type | mold 104 Preform 105 Preform bottom part 106 Preform mouth part 107 Preheating furnace 108 Blow mold 109 Drawing rod 110 Gas 112 Bottle-shaped molding 113 Belt base material 1 Photosensitive drum 2 Primary charger 3 Exposure light 6 Bias applying means 7 Intermediate transfer belt 8 Charging device 10 Transfer material supply roller 11 Transfer material guide 12 Transfer material transport belt 13 Cleaning device 14 Fixing device 41 Developing device 42 Developing device 43 Developing device 44 Developing device 62 Primary transfer roller 63 Secondary transfer roller 64 Roller 65 Roller 66 Roller S1 Bias power source S3 Bias power source S4 Bias power source S5 Bias power source P Transfer material 15 Belt substrate 16 Surface layer

Claims (6)

An electron having a belt substrate formed from a thermoplastic resin composition containing a thermoplastic resin, a solid lubricant, and a polyether ester amide as a conductive agent, and a surface layer formed on the belt substrate A method of manufacturing an intermediate transfer belt for photography,
Forming a preform from the thermoplastic resin composition;
The preform is preheated, the preform heated in the mold is stretched using a stretching rod that moves at a predetermined speed, and a gas is introduced into the preform stretched by the stretching rod. A step of inflating a preform in a mold to form a bottle-shaped product,
Cutting the mouth side and bottom side of the bottle-shaped molded product to prepare a belt substrate;
And a step of applying a coating solution to the surface of the belt substrate, drying and curing the coating solution to form a surface layer, and a method for producing an electrophotographic intermediate transfer belt.   2. The process for producing an electrophotographic intermediate transfer belt according to claim 1, wherein the thermoplastic resin is polyethylene naphthalate, polyethylene terephthalate, polyethylene naphthalate-terephthalate copolymer, or a mixture thereof.   3. The method for producing an electrophotographic intermediate transfer belt according to claim 1, wherein the coating liquid contains dipentaerythritol hexaacrylate and conductive particles made of a metal oxide.   4. The method for producing an electrophotographic intermediate transfer belt according to claim 1, wherein the solid lubricant is silicone powder.   The method for producing an electrophotographic intermediate transfer belt according to claim 1, wherein the belt base material has a surface roughness Rzjis of 0.1 μm or less.   6. The method for producing an electrophotographic intermediate transfer belt according to claim 1, wherein the surface layer has a layer thickness of 0.5 μm or more and 5 μm or less.

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