JP2002023514A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which has high transfer efficiency and can stably supply an image of high picture quality free of the void phenomenon. SOLUTION: The image forming device having an intermediate transfer body has a surface layer containing resin having silicon as a terminal base. Here, the surface layer of the intermediate transfer body, preferably, contains fluororesin powder and/or a conductive agent, has a friction coefficient of 0.2 to 0.5, and has surface roughness Rz (10-point mean roughness) of less than 1.5 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine or a printer, and more particularly, to a method of transferring a toner image formed on an image carrier to an intermediate transfer member once and then transferring the toner image to the intermediate transfer member. The present invention relates to an image forming apparatus that obtains a reproduced image by transferring the image to a recording medium such as a sheet.

[0002]

2. Description of the Related Art An image forming apparatus using an electrophotographic method is:
Photoconductive photoreceptor (image carrier) made of inorganic or organic material
A uniform charge is formed thereon, an electrostatic latent image is formed by a laser beam or the like that modulates an image signal, and then the electrostatic latent image is developed with a charged toner to obtain a visualized toner image. And
The required reproduced image is obtained by electrostatically transferring the toner image to a transfer material such as a recording paper via an intermediate transfer member or directly. Particularly, as an image forming apparatus adopting a system in which a toner image formed on the image carrier is primarily transferred to an intermediate transfer member, and a toner image on the intermediate transfer member is secondarily transferred to recording paper, Japanese Patent Laid-Open No. The one disclosed in 206567 and the like is known.

The materials used for the image forming apparatus employing the above-mentioned intermediate transfer member system include polycarbonate resin (JP-A-6-095521) and PVDF (polyvinylidene fluoride) (JP-A-5-200904, JP-A-6-200904).
228335), polyalkylene phthalate (JP-A-6-149081), PC (polycarbonate) / P
AT (polyalkylene terephthalate) blend material (JP-A-6-149083), ETFE (ethylene tetrafluoroethylene copolymer) / PC, ETFE / PA
T, PC / PAT blend material (Japanese Unexamined Patent Publication No.
No. 79) has been proposed using a conductive endless belt made of a thermoplastic resin.

When carbon black is dispersed in a fluorine-based resin such as an ethylene tetrafluoroethylene copolymer, the adhesion between the fluorocarbon resin and the carbon black is poor. There is a problem that the chain state of black changes and the resistance decreases.
Further, in the case of a polycarbonate-based resin material in which carbon black is dispersed, the polarity of the polycarbonate is strong, so the toner releasability is poor, and the toner adheres to the transfer surface over time. In addition, since stress cracking is likely to occur, cracks may occur on the belt transfer surface due to stress at the roll bending portion during belt driving and stress applied to the belt edge portion, and problems such as breakage of the belt may occur. The above-mentioned complicated replacement of the intermediate transfer body due to a decrease in resistance of a part of the transfer surface, a breakage of the belt, or the like is not preferable because it leads to an increase in maintenance labor and running costs.

A belt material used in an image forming apparatus employing the intermediate transfer member system is disclosed in JP-A-9-30.
No. 5038 and Japanese Patent Application Laid-Open No. Hei 10-240020 propose an elastic belt containing a reinforcing material formed by laminating a woven fabric such as polyester and an elastic member. The above-mentioned elastic belt with a reinforcing material, which has elasticity by itself, runs in a state of being displaced in the axial direction of the roll, so that the occurrence of so-called offset running or meandering is reduced, but the Young's modulus is 3MP.
a (3 kg / mm ² ), a problem of color misregistration due to elongation, creep and the like of the belt material occurs.

A material having excellent mechanical properties includes a polyimide resin.
560727 (JP-A-63-31263) proposes a carbon black-dispersed polyimide seamless belt. Since the polyimide resin material has excellent mechanical properties, the recording paper is pressed against the recording medium using a bias roll, an electric field is applied, and the toner image is electrostatically transferred. Since the deformation due to the pressing force is small, the pressing force by the bias roller concentrates. For this reason, there is a problem that an image defect such as a hollow image of a line image occurs due to a cause such as agglomeration of the toner and an increase in the charge density, causing an internal discharge in the toner layer and changing the polarity of the toner. .

On the other hand, Japanese Patent Application Laid-Open No. 5-129555 proposes an image forming apparatus using a belt-shaped image carrier and a drum-shaped intermediate transfer body. In this image forming apparatus, as an intermediate transfer member, a conductive species such as carbon black is added to polycarbonate or Teflon (registered trademark) on a substrate of an aluminum drum to obtain a volume resistivity of 10 ⁷ to 1.
A high-rigidity intermediate transfer drum having a semiconductive layer of 0 ¹¹ Ω · cm is used. After the toner image formed on the image carrier belt is once electrostatically transferred to this intermediate transfer drum,
The image is electrostatically transferred from the intermediate transfer drum to recording paper.

When such a high rigidity intermediate transfer drum is used in combination with an image carrier belt whose substrate is soft and deformable, the image carrier belt flexes during transfer and comes into close contact with the intermediate transfer drum, and Although a nip region having a desired size can be formed between the body belt and the intermediate transfer drum, it is difficult to reduce the size of the image forming apparatus by using such a belt-type image carrier. Therefore, it is conceivable to use a drum-type image carrier instead of a belt-type image carrier. However, a high-rigidity image carrier using a high-rigidity intermediate transfer drum and an aluminum drum as a base is used as the image carrier. When combined with a drum, a sufficiently large nip area is not formed between the image carrier drum and the intermediate transfer drum, and it is difficult to obtain high transfer efficiency.

Therefore, a method for lowering the hardness of the elastic layer of the intermediate transfer body to make the stress distribution in the transfer area uniform is as follows.
A method using a foam layer as an elastic layer is disclosed in Japanese Patent Laid-Open No. 4-287.
070 publication. However, when a foamed layer is used, since it is used while being pressed by the image carrier drum, there is a problem that the pressed portion is deformed with time. Japanese Patent Application Laid-Open No. 8-73680 discloses a rubber composition having a low hardness and a small compression set composed of EDPM (ethylene-propylene-diene terpolymer) and acrylic rubber, which is used for a transfer roller or the like. Is disclosed. However, even with these rubber compositions, a material having a low hardness, a resistance value within a predetermined narrow range, which is suitable for the above-mentioned intermediate transfer member, and which does not have a problem that the pressed portion is deformed with time is used. It is difficult to get.

For example, Japanese Patent Application Laid-Open No. 7-152262 discloses an intermediate transfer drum in which an elastic layer made of urethane rubber having appropriate elasticity and appropriate conductivity is formed on the surface of an aluminum drum having a thickness of 3 mm. Is disclosed in combination with a highly rigid image carrier drum. It has been proposed to improve the toner transferability (primary transfer) from the image carrier drum to the intermediate transfer drum by making the releasability of the intermediate transfer drum worse than the releasability of the image carrier drum. However, in this case, there is a problem that toner transferability from the intermediate transfer drum to the recording medium (secondary transfer) is deteriorated. Further, in this image forming apparatus, in order to make the stress distribution of the intermediate transfer drum in the transfer area uniform,
Since urethane rubber is used for the surface layer of the intermediate transfer drum, and the frictional force of the urethane rubber with respect to the image carrier drum is large, minute deformation due to stick slip occurs with the rotating image carrier drum. For this reason, the stress distribution in the nip region formed between the image carrier drum and the intermediate transfer drum becomes locally uneven, and a hollow image occurs in a detailed image such as a character image.

As a material for forming the transfer surface, a material having a low surface energy with a toner releasing property is used to improve the image quality defect in which the line image is lost in the intermediate transfer belt or the intermediate transfer drum. There is a method, and Japanese Patent Application Laid-Open No. 9-269676 proposes a belt material composed of a material mainly composed of a silicone resin in a laminated structure of two or more layers having a transfer surface made of a material having excellent toner release properties. ing. However, when a silicon-based material is used as the transfer layer material, there is a problem that a slight deformation due to stick slip occurs on the transfer surface due to stickiness of the surface and a large friction coefficient with respect to the opposing photosensitive member. The stress distribution in the nip region formed between the photosensitive member and the photosensitive member becomes locally uneven, and a hollow image (hollow character) occurs in a detailed image such as a character image. Further, there is a problem that contamination of the photoreceptor by low molecular components such as siloxane occurs.

Japanese Patent Application Laid-Open No. Hei 7-92825 proposes a fluororesin as a material constituting the transfer surface. However, fluororesin has a high surface hardness,
There has been a problem that stability over time is poor, such as scratches are easily generated and minute cracks are generated on the surface due to bending of the roll portion during driving.

Japanese Patent Application Laid-Open No. 11-15294 proposes using a fluorine-based latex containing fine fluorine particles as a material for forming a transfer surface.
However, in the case of the above-mentioned fluorine-based latex, since the polarity of the frictional charging sequence of the fluorine-based latex is on the minus side, the negatively charged toner on the transfer surface is positively charged to have the opposite polarity (with the plus charge). Further, there is a problem that toner is generated. When the toner of the opposite polarity scatters during transfer, a problem that transfer efficiency is reduced occurs. Further, at a temperature of 230 to 300 ° C. for vulcanizing the fluorine latex, the dispersed fine particles of fluorine are deposited on the transfer surface to form a layer. However, since this layer formation is not uniform, the transfer surface has There are problems such as an increase in surface roughness and loss of transfer uniformity.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide an image forming apparatus which has a high transfer efficiency and is capable of stably supplying a high-quality image without causing a hollow phenomenon.

[0015]

Means for solving the above problems are as follows. That is, <1> an image forming apparatus provided with an intermediate transfer member, wherein the intermediate transfer member has a surface layer containing a resin having silicon as a terminal group. <2> The image forming apparatus according to <1>, wherein the surface layer of the intermediate transfer body contains a fluororesin powder. <3> The image forming apparatus according to <1> or <2>, wherein the surface layer of the intermediate transfer member contains a conductive agent. <4> The friction coefficient of the surface layer of the intermediate transfer member is 0.5
An image forming apparatus according to any one of <1> to <3> below. <5> The surface roughness of the surface layer of the intermediate transfer member is Rz
<1> in which the (10-point average roughness) is 1.5 μm or less.
To the image forming apparatus according to any one of <4> to <4>. <6> The intermediate transfer body has a metallic cylindrical substrate, and has two or more layers on the cylindrical substrate, and the layer in contact with the cylindrical substrate has a JIS-A hardness of 30 degrees or less, An elastic material having a compressive strain of 5% or less is contained, and the layer thickness is 3 to
The image forming apparatus according to any one of the above items <1> to <5>, which is 10 mm. <7> An image forming apparatus including a charging member, wherein the charging member has a surface layer containing a resin having silicon as a terminal group.

Since the intermediate transfer member in the image forming apparatus of the present invention contains a resin having silicon as a terminal group in the material constituting the transfer surface, the polarity of the triboelectric charging sequence is positive, and the fluorine The tendency of negatively charged toner to be positively charged as in the case of using a resin is reduced, and the problem of generating toner of opposite polarity is eliminated. Therefore, it is possible to stably supply a high-quality image which has high transfer efficiency and does not cause the hollow phenomenon.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Image forming apparatus of the first invention] The image forming apparatus of the first invention is provided with an intermediate transfer body, and the intermediate transfer body has a surface layer containing a resin having silicon as a terminal group. . The intermediate transfer member has a surface layer on a substrate,
If necessary, another layer such as an elastic layer is provided between the substrate and the surface layer.

(Surface Layer of Intermediate Transfer Body) The surface layer contains at least a resin having silicon as a terminal group and, if necessary, other components.

-Resin Having Silicon as Terminal Group- Examples of the resin having silicon as a terminal group include silicone-modified acrylic resin, silicone-modified urethane resin, silicone-modified epoxy resin, and silicone-modified polyamide resin. Specifically, X-22-8004 (silicone-modified acrylic resin), X-22-2760 (silicone-modified urethane resin), ES-100T (silicone-modified epoxy resin), and X-22-made by Shin-Etsu Chemical Co., Ltd. 8941 (silicone-modified polyamide resin). These can be used by adding a certain amount to a resin component mainly composed of a urethane resin, a polyester resin or the like.

The content of the resin having silicon as a terminal group in the total binder resin can be appropriately selected depending on the purpose. For example, 10 to 120 parts by weight based on 100 parts by weight of the resin such as urethane is used. Part is preferred, and 40 to 10
0 parts by weight is more preferred. If the content is less than 10 parts by weight, the effect of introducing silicon into the terminal group may be lost, while if the content exceeds 120 parts by weight,
The surface layer may be too hard, causing problems such as the generation of minute cracks due to the roll during driving.

-Other components--Fluororesin powder-The surface layer of the intermediate transfer member according to the present invention is excellent in toner releasability when a fluororesin powder is dispersed as the other component, and is resistant to This is preferable because the coefficient of friction with respect to the photoreceptor becomes small, and the above-described minute deformation of the transfer surface due to stick slip with the photoreceptor eliminates the problem of deteriorating the transfer image quality of details. The fluororesin powder is not particularly limited. For example, polyvinyl fluoride, PVDF, tetrafluoroethylene (TFE) resin, chlorotrifluoroethylene (C
TFE) resin, ETFE, CTFE-ethylene copolymer, PFA (TFE-perfluoroalkylvinyl ether copolymer), FEP (TFE-hexafluoropropylene (HFP) copolymer), EPE (TFE-HFP)
-Perfluoroalkyl vinyl ether copolymer) or one or more of them. More specifically,
As the TFE resin powder, the average particle size is 0.3 to 0.7 μm
KTL-500F manufactured by Kitamura Co., Ltd.

The addition amount of the fluororesin powder is preferably 10 to 50% by weight based on the total solid weight of the surface layer.
20-40% by weight is more preferred. If the amount is less than 10% by weight, the effect of the releasing property of the fluororesin may be lost. On the other hand, if the amount exceeds 50% by weight, there arises a problem that a reverse polarity toner is generated. There is.

--Conductive Agent-- In the surface layer of the intermediate transfer member of the present invention, when a conductive agent is dispersed as the other component, the electric resistance of the surface layer can be stably obtained at a desired value. It is preferable because it can be performed. As the conductive agent, for example, carbon black,
Metals or alloys such as graphite, aluminum, nickel, and copper alloys, and metal oxides such as tin oxide, zinc oxide, potassium titanate, tin oxide-indium oxide or tin oxide-antimony oxide composite oxides, and the like are commonly used. Examples of the conductive agent used for imparting the required conductivity include carbon black such as furnace black, Ketjen black, and channel black. More specifically, granular acetylene black manufactured by Electrochemical Co., Ltd., HS-500 manufactured by Asahi Carbon Co., Ltd., Asahi Thermal FT, Asahi Thermal MT, Ketjen Black manufactured by Lion Aguso Co., Ltd., Vulcan XC manufactured by Cabot Co., Ltd. -72 and the like. These may be used alone or in combination of two or more.

The amount of the conductive agent to be added is preferably 1 to 10% by weight, more preferably 2 to 6% by weight, based on the total solid weight of the surface layer. When the amount is less than 1% by weight,
In some cases, the electric resistance becomes too high to obtain a desired electric resistance stably. On the other hand, when the addition amount exceeds 10% by weight, the electric resistance becomes too low,
A desired electric resistance may not be obtained.

The thickness of the surface layer of the intermediate transfer member in the present invention varies depending on the shape (belt shape, drum shape) of the intermediate transfer member, but is preferably 2 to 50 μm, and more preferably 10 to 30 μm.
μm is more preferred. When the thickness is less than 2 μm, uneven coating may occur, while the thickness is less than 50 μm.
If it exceeds μm, the thickness of the coating film may not be uniformly obtained due to dripping or the like.

<Friction Coefficient> In the intermediate transfer member of the present invention, the friction coefficient of the surface layer is preferably 0.5 or less, more preferably 0.2 to 0.5. If the coefficient of friction exceeds 0.5, the transfer surface may be slightly deformed due to stick slip with the photoreceptor, thereby deteriorating the transfer image quality of details. The coefficient of friction is
Static friction coefficient meter as shown in Fig. 5 (manufactured by Kyowa Interface Science Co., Ltd.)
Can be measured. The static friction coefficient meter shown in FIG. 5 includes a steel ball (diameter: 3 mm) 303, a balance for zero adjustment 3
04, a load cell 305, and a load (100 g) 306. Specifically, a film having a thickness of 20 μm is formed using the material 301 constituting the surface layer of the intermediate transfer member, and the film is set on the fixed base 302, and has a moving speed of 0.1 cm /
The friction coefficient is measured under the conditions of a load of 100 g for a second.

<Surface Roughness> In the intermediate transfer member of the present invention, the surface layer has a surface roughness of Rz (10-point average roughness) of 1.
It is preferably at most 5 μm, more preferably at most 1.0 μm. When the surface roughness is larger than 1.5 μm, transfer uniformity may be impaired. The surface roughness is measured in accordance with JIS B0601 and has a measurement length of 2.5.
mm, cutoff 0.8mm, measuring speed 0.6mm / s
It measures under the condition of ec.

<Surface Resistivity> The intermediate transfer member of the present invention has a transfer surface having a surface resistivity of 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ω /.
□, preferably 1 × 10 ¹¹ to 1 × 10 ¹³ Ω /
□ is more preferable. This surface resistivity is 1 × 1
If it is higher than 0 ¹⁴ Ω / □, peeling discharge is likely to occur at the post nip where the image transfer member and the intermediate transfer member of the primary transfer portion are peeled off, and the portion where the discharge is generated is a blank image defect. May occur. On the other hand, the surface resistivity is 1 ×
If it is less than 10 ¹⁰ Ω / □, the electric field strength in the pre-nip portion becomes strong, and the gap discharge in the pre-nip portion is easily generated, so that the granularity of the image quality may be deteriorated. Therefore, by setting the surface resistivity in the above range, it is possible to prevent white spots due to discharge generated when the surface resistivity is high and deterioration of image quality generated when the surface resistivity is low.

In the intermediate transfer member of the present invention, the surface resistivity of the transfer surface is determined by a circular electrode (for example, Mitsubishi Yuka Co., Ltd.).
High-Rester IP “HR Probe”)
It can be measured according to SK6991. The method for measuring the surface resistivity will be described with reference to the drawings. FIG. 6 is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode. The circular electrode shown in FIG. 6 includes a first voltage application electrode A and a plate-shaped insulator B. First voltage application electrode A
Includes a columnar electrode portion C and a cylindrical ring-shaped electrode portion D having an inner diameter larger than the outer diameter of the columnar electrode portion C and surrounding the columnar electrode portion C at regular intervals. Columnar electrode portion C and ring-shaped electrode portion D in first voltage application electrode A
When the intermediate transfer member T is sandwiched between the first electrode V and the plate-shaped insulator B, and a voltage V (V) is applied between the columnar electrode portion C and the ring-shaped electrode portion D in the first voltage application electrode A. Flowing current I
By measuring (A), the surface resistivity ρs (Ω / □) of the transfer surface of the intermediate transfer body T can be calculated by the following equation (1). Here, in the following formula (1), d (mm) indicates the outer diameter of the columnar electrode portion C, and D (mm) indicates the inner diameter of the ring-shaped electrode portion D. Equation (1) ρs = π × (D + d) / (D−d) × (V
/ I)

<Volume Resistivity> The intermediate transfer member of the present invention preferably has a volume resistivity of 1 × 10 ⁸ to 1 × 10 ¹⁴ Ωcm, preferably 1 × 10 ¹⁰ to 1 × 10 ¹² Ωcm. More preferred. This volume resistivity is 1 × 10 ⁸ Ωc
If it is less than m, the electrostatic force that holds the charge of the unfixed toner image transferred from the image carrier to the intermediate transfer member is less likely to work, so that the electrostatic repulsion between the toners and the image edge Due to the force of the nearby fringe electric field, toner may be scattered around the image (blurring), and an image with large noise may be formed. On the other hand, the volume resistivity is 1 ×
Is higher than 10 ¹⁴ [Omega] cm, in order retention of charge is large, it may be necessary to neutralizing mechanism for the intermediate transfer member surface by the transfer electric field at the primary transfer is charged. Therefore,
By setting the volume resistivity in the above range, it is possible to solve the problem that the toner is scattered or that a static elimination mechanism is required.

When the intermediate transfer member of the present invention has a belt shape, the volume resistivity is measured according to JIS K6991 using a circular electrode (for example, HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.). be able to. A method for measuring the volume resistivity will be described with reference to the drawings.
FIG. 7 is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode. The circular electrode shown in FIG. 7 includes a first voltage applying electrode A ′ and a second voltage applying electrode B ′. The first voltage applying electrode A ′ has a cylindrical electrode portion C ′ and an inner diameter larger than the outer diameter of the cylindrical electrode portion C ′, and has a cylindrical shape surrounding the cylindrical electrode portion C ′ at a constant interval. And a ring-shaped electrode portion D ′. The intermediate transfer member T is sandwiched between the cylindrical electrode portion C ′ and the ring-shaped electrode portion D ′ of the first voltage application electrode A ′ and the second voltage application electrode B ′, and the circle of the first voltage application electrode A ′ is formed. Columnar electrode part C 'and second voltage applying electrode B'
Current I flowing when a voltage V (V) is applied between
By measuring (A), the volume resistivity ρv (Ωcm) of the intermediate transfer body T can be calculated by the following equation (2). Here, in the following equation (2), t indicates the thickness of the intermediate transfer body T. Equation (2) ρv = 19.6 × (V / I) × t

(Substrate of Intermediate Transfer Body) The intermediate transfer body of the present invention may be in the form of a belt or a drum. In the case of a belt shape, as the resin material used as the base material of the intermediate transfer body, for example, polyimide,
Polyester, polyetheretherketone, polyamide, polycarbonate, polyvinylidene fluoride (PVD
F), polyfluoroethylene-ethylene copolymer (ETF)
Resin materials such as E) and resin materials containing these as main raw materials. Further, a resin material and an elastic material can be blended and used. Elastic materials include polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber,
A material obtained by blending one kind or two or more kinds of silicone rubber or the like can be used. If necessary, one or a combination of two or more conductive agents for imparting electronic conductivity or ionic conductivity are added to the resin material and the elastic material used for these base materials.

When the intermediate transfer member in the present invention is in the form of a drum, it is preferable to use a cylindrical substrate made of, for example, aluminum, stainless steel (SUS), copper or the like as the substrate. . On this cylindrical substrate,
If necessary, the surface layer can be formed on the elastic layer by covering the elastic layer.

(Other Layers of Intermediate Transfer Body) When the intermediate transfer body of the present invention is in the form of a drum, it is preferable to have an elastic layer as the other layer between the substrate and the surface layer. In particular, the intermediate transfer member has a metallic cylindrical substrate and two or more layers on the surface of the cylindrical substrate, and a layer (elastic layer) in contact with the cylindrical substrate has a JIS-A hardness of 30 degrees. In the following, it is preferable that an elastic material having a compressive strain of 5% or less be contained and the layer thickness be 3 to 10 mm.
As the intermediate transfer member, the roll hardness that can stably obtain a uniform nip width and nip pressure is 30 to 6 as Asker C.
0 °, and the material constituting the elastic layer is JI
By using an elastic material having an SA hardness of preferably 10 degrees or more and 30 degrees or less, more preferably 15 degrees or more and 25 degrees or less, preferably in the range of 3 to 10 mm, more preferably in the range of 4 to 7 mm, A stable nip width and nip pressure can be obtained. The elastic material used for the elastic layer preferably has a compression set of 5% or less, preferably 3% or less at 70 degrees for 22 hours so as not to hinder the recovery of the elastic deformation of the cylindrical elastic layer. Is more preferable.
As the elastic material forming the elastic layer, silicon rubber, urethane rubber, or the like can be used. However, any other material that satisfies the above characteristics may be used.

Since the image forming apparatus of the present invention includes the intermediate transfer member having the above-described structure, it has a high transfer efficiency and can stably supply a high-quality image without causing a hollow phenomenon. . The present invention is not particularly limited as long as it is an intermediate transfer body type image forming apparatus. For example, a normal mono-color image forming apparatus in which only a single-color toner is stored in a developing device, or a color image forming in which a toner image carried on an image carrier such as a photosensitive drum is repeatedly primary-transferred sequentially to an intermediate transfer body The image forming apparatus may be any of an apparatus, a tandem-type color image forming apparatus in which a plurality of image carriers each having a developing unit for each color are arranged in series on an intermediate transfer member.

Hereinafter, an embodiment of the image forming apparatus of the present invention will be described with reference to the drawings. A first embodiment of an image forming apparatus according to the present invention includes an image carrier that forms an electrostatic latent image according to image information, and visualizes the electrostatic latent image formed on the image carrier as a toner image with toner. Developing device,
A primary transfer unit for transferring the toner image carried on the image carrier onto an intermediate transfer member; and a secondary transfer unit for transferring the toner image on the intermediate transfer member to a recording medium. And a belt-shaped intermediate transfer member having the above-described configuration.

FIG. 1 is a schematic view of a color image forming apparatus according to a first embodiment using a belt-shaped intermediate transfer member. The image forming apparatus includes a photosensitive drum 1 as an image carrier, an intermediate transfer belt 2 as an intermediate transfer member, a bias roller 3 (second transfer unit) as a transfer electrode, and a sheet for supplying a recording sheet as a transfer medium. Tray 4, developing device 5 using Bk (black) toner, developing device 6 using Y (yellow) toner, M
(Magenta) toner developing device 7, C (cyan) toner developing device 8, intermediate transfer member cleaner 9, peeling claw 1
3, belt rollers 21, 23 and 24, backup roller 22, conductive roller 25 (first transfer means), electrode roller 26, cleaning blade 31, recording paper 41, pickup roller 42, and feed roller 43. .

In FIG. 1, the photosensitive drum 1 rotates in the direction of arrow A, and its surface is uniformly charged by a charging device (not shown). An image writing unit such as a laser writing device writes a first color (for example, B
k) An electrostatic latent image is formed. This electrostatic latent image is developed with toner by the black developing device 5 to form a visualized toner image T. The toner image T reaches the primary transfer portion on which the conductive roller 25 (first transfer unit) is disposed by the rotation of the photosensitive drum 1, and an electric field having a reverse polarity is applied to the toner image T from the conductive roller 25. As a result, the toner image T
Is primarily transferred by rotation of the intermediate transfer belt 2 in the direction of arrow B while being electrostatically attracted to the intermediate transfer belt 2.

Hereinafter, the second color toner image, the third color toner image
A color toner image and a fourth color toner image are sequentially formed, and are superimposed on the intermediate transfer belt 2 to form a multiple toner image. The multi-toner image transferred to the intermediate transfer belt 2 reaches a secondary transfer section provided with a bias roller 3 (second transfer unit) by rotation of the intermediate transfer belt 2. The secondary transfer unit includes a bias roller 3 provided on the surface of the intermediate transfer belt 2 on which the toner image is carried, a backup roller 22 disposed to face the bias roller 3 from the back side of the intermediate transfer belt 2, and This backup roller 22
The electrode roller 26 is configured to rotate while being pressed against.

The recording paper 41 is taken out one by one from a recording paper bundle stored in the paper tray 4 by a pickup roller 42, and is fed between the intermediate transfer belt 2 of the secondary transfer portion and the bias roller 3 by a feed roller 43. The paper is fed at a predetermined timing. The fed recording paper 41 is applied to the bias roller 3.
The toner image carried on the intermediate transfer belt 2 is transferred by the press-contact conveyance by the backup roller 22 and the rotation of the intermediate transfer belt 2.

The recording paper 41 onto which the toner image has been transferred is placed on the separation claw 13 at the retracted position until the primary transfer of the final toner image is completed.
Is actuated to separate from the intermediate transfer belt 2,
The toner image is conveyed to a fixing device (not shown) and fixed by a pressure / heat treatment to form a permanent image. The intermediate transfer belt 2 on which the transfer of the multi-toner image onto the recording paper 41 has been completed is subjected to removal of residual toner by an intermediate transfer body cleaner 9 provided downstream of the secondary transfer unit, and is ready for the next transfer. Further, the bias roller 3 is attached so that a cleaning blade 31 made of polyurethane or the like always contacts.
Foreign matters such as toner particles and paper dust adhered by the transfer are removed.

In the case of transferring a single-color image, the primary-transferred toner image T is immediately secondary-transferred and conveyed to a fixing device.
In the case of transferring a multicolor image by superimposing a plurality of colors, the rotation of the intermediate transfer belt 2 and the rotation of the photosensitive drum 1 are synchronized so that the toner images of the respective colors are accurately matched in the primary transfer section, so that the toner images of the respective colors are formed. Do not shift. In the secondary transfer section, an output pressure (transfer voltage) having the same polarity as the polarity of the toner image is applied to the electrode roller 26 which is in pressure contact with the backup roller 22 disposed opposite to the bias roller 3 via the intermediate transfer belt 2. Then, the toner image is transferred to the recording paper 41 by electrostatic repulsion.

According to a second embodiment of the image forming apparatus of the present invention, there is provided an image carrier for forming an electrostatic latent image corresponding to image information;
A developing device for visualizing the electrostatic latent image formed on the image carrier as a toner image with toner, a primary transfer unit for transferring the toner image carried on the image carrier onto an intermediate transfer body, and the intermediate transfer Secondary transfer means for transferring a toner image on the body to a recording medium, wherein the intermediate transfer body is the drum-shaped intermediate transfer body having the above-described configuration. FIG. 2 is a schematic diagram of a color image forming apparatus according to a second embodiment using a drum-shaped intermediate transfer member. The surface of a photoconductor (image carrier) 101 formed by coating a photoconductor material on an aluminum pipe is
Then, the electrostatic latent image is formed on the surface of the photoconductor by the scanning exposure 104b emitted from the image writing device 104a according to the image information. This electrostatic latent image is developed and visualized by the developing device 105 of the developing device 105 corresponding to the color information of the electrostatic latent image formed this time.

The visualized toner image is applied to the photosensitive member 10
In the transfer area P _{1 where the first} transfer roller 1 and the intermediate transfer drum (intermediate transfer member) 110 are in contact with each other, a voltage is applied between the intermediate transfer drum 110 and the photosensitive member 101 from a power source (not shown) to the surface of the intermediate transfer drum 110 Is transferred by applying. The surface of the photoreceptor 101 after the transfer is irradiated with light from a discharge lamp 108 to be discharged, and the toner remaining on the surface of the photoreceptor 101 is removed by the cleaning device 103.

The above process is repeated a plurality of times, and each time a developing device 105K having a developer of a different color according to the image information,
The toner images are developed and visualized by 105Y, 105M, and 105C, sequentially transferred and laminated from the surface of the photoconductor 101 to the intermediate transfer drum 110, and a plurality of toner images are laminated and formed on the surface of the intermediate transfer drum 110.

The color toner image formed on the surface of the intermediate transfer drum 110 is formed by coating the intermediate transfer drum 110 and a metal shaft with an elastic material having a resistance of about 10 ⁸ Ω. 106 (secondary transfer unit), the intermediate transfer drum 110
Due to the voltage applied between the transfer roller 106 and the transfer roller 106, the image is collectively transferred from the surface of the intermediate transfer drum 110 to the recording material 111 conveyed by the paper conveyance roller 109. A peeling charger may be used instead of the transfer roller. Further, a peeling charger may be provided near the transfer area together with the transfer roller. The toner image collectively transferred to the surface of the recording material 111 is conveyed to the fixing device 107 and fixed by the fixing device 107.

Next, an example of the structure of the intermediate transfer drum 110 will be described with reference to FIG. In the intermediate transfer drum 110 of the present embodiment, a rubber elastic layer 203 for forming a stable transfer area is formed on a base material 204, and a leakage prevention and a rubber elastic layer An intermediate layer 202 functioning as a bleed block layer that blocks bleeding of the bleed component is formed, and a surface layer 201 having a high toner release property is formed on the intermediate layer 202.

According to a third embodiment of the image forming apparatus of the present invention, there is provided an image carrier for forming an electrostatic latent image according to image information;
A developing device for visualizing the electrostatic latent image formed on the image carrier as a toner image with toner, and a primary transfer unit for transferring the toner image carried on the image carrier to one or more first intermediate transfer members And transferring the toner image on the first intermediate transfer member to a second
And a tertiary transfer unit for transferring the toner image on the second intermediate transfer member to a recording medium. At least one of the one or more first intermediate transfer members One is a drum-shaped intermediate transfer member having the above-described configuration.

FIG. 4 is a schematic view of a color image forming apparatus according to a third embodiment using a drum-shaped intermediate transfer member. This image forming apparatus is a drum-shaped photosensitive member (image carrier) 101K having a photosensitive layer on the surface corresponding to four colors of black (K), yellow (Y), magenta (M), and cyan (C). ,
101Y, 101M, and 101C, and chargers 102K, 102Y, and 10 that uniformly charge these photosensitive members, respectively.
2M, 102C, and an image writing device 104 that irradiates image light onto a uniformly charged photoconductor to form an electrostatic latent image.
K, 104Y, 104M, 104C and K, Y, M, C
Developing units 105K, 10 containing developers of respective colors
5Y, 105M, 105C and the four photoconductors 101
K, 101Y, 101M, and 101C, a first intermediate transfer drum (intermediate transfer member) 110A that contacts two photosensitive members 101K and 101Y, and another two photosensitive members 101
M, first intermediate transfer drum 110B in contact with 101C
And these two first intermediate transfer drums 110A, 110A
10B, a second intermediate transfer drum 110C that contacts both
A transfer roller 106 (tertiary transfer unit) for collectively transferring the toner image superimposed and transferred on the second intermediate transfer drum 110C onto a recording material 111 conveyed by a paper conveying roller 109; And a fixing device 107 for fixing the toner image on the fixing device 111.

Each photoconductor 101K, 101Y, 101M,
An electrostatic latent image corresponding to each color is formed on 101C,
Each of the developing devices 105K, 105Y, 105M, and 105C is developed with each color toner to form a toner image of each color. Each photoconductor 101K, 101Y, 101M, 101C
Of the upper color toner images, the toner images on the photoconductors 101K and 101Y are superimposed and transferred to one first intermediate transfer drum 110A, and the toner images on the photoconductors 101M and 101C are the other toner images. 1 intermediate transfer drum 110
B is over-transferred. Each color toner image transferred to the two first intermediate transfer drums 110A and 110B is
The toner image on the second intermediate transfer drum 110C is superimposed and transferred onto the second intermediate transfer drum 110C, and the toner image on the second intermediate transfer drum 110C is collectively transferred onto the recording material 111 as described above.
7, the image is fixed on the recording material 111.

[Image Forming Apparatus of the Second Invention] The image forming apparatus of the second invention comprises a charging member, and the charging member has a surface layer containing a resin having silicon as a terminal group. I do. The surface layer of the charging member further contains other components as necessary. The charging member,
By having a surface layer containing a resin having silicon as a terminal group, problems such as generation of toner of opposite polarity can be prevented. The charging member referred to in the present invention is:
The concept includes a transfer roller in addition to the charger. The resin having silicon as a terminal group used in the second invention is the same as the resin having silicon as a terminal group used in the first invention described above.

[0052]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.
In the following description, “parts” means “parts by weight”. (Example 1) -Preparation of Intermediate Transfer Drum- [Preparation of Substrate] The vicinity of both ends of an aluminum pipe blank having a length of 248 mm and an outer diameter of 32 mm was lathe-processed, and a flange having a rotating shaft was press-fitted into the processed portion. . Further, based on the rotation axis of the flange, the surface of the aluminum tube was finished by lathing and polishing to an outer diameter tolerance of 0.01 mm or less and an outer diameter deflection accuracy of 0.01 mm as a base material.

[Formation of Rubber Elastic Layer] After blasting the surface of this pipe and applying a primer, it is inserted and set in a mold, and cured at a low temperature with a JIS-A hardness of 15 degrees and a compressive strain of 5%. A conductive liquid silicone rubber having a volume resistivity of 10 ⁵ Ωcm was injected, cured and molded. This is removed from the mold, and further cured at 200 ° C. for 30 minutes.
A rubber elastic layer was formed. The thickness of this rubber elastic layer is 5 mm
Met.

[Formation of Intermediate Layer] Next, after the application of the primer,
A solution in which a butyl acetate solution is mixed with a fluororubber, a conductive material, a silane coupling agent, and a curing agent is applied on the rubber elastic layer by a spray gun, and then air-dried for 10 minutes. Dry for 10 minutes, thickness 2
An intermediate layer of 0 μm was formed. The hardness of the fluororubber used was 65 degrees in JISA hardness and the volume resistivity was 10 ⁸ Ωcm.

[Formation of Surface Layer] Next, an acrylic resin and a urethane resin (4
0 parts: 60 parts), spray-coated with JYL841 manufactured by Acheson Japan Ltd. in which a conductive agent (2% by weight) and a fluororesin powder (30% by weight) are dispersed, and left at room temperature for 10 minutes. After preliminary drying in an atmosphere at 50 ° C. for 30 minutes, the film was held at 180 ° C. for 30 minutes and cured to prepare an intermediate transfer drum (intermediate transfer body) having a surface layer having a thickness of 20 μm.

Table 1 below shows the measurement results of the volume resistivity, the coefficient of friction, and the surface roughness of the obtained intermediate transfer drum.
The volume resistivity of the intermediate transfer drum is determined by pressing the intermediate transfer drum against a metal plate with a load of 1 kg, applying a voltage of 500 V to the metal plate and the metal substrate of the intermediate transfer drum, and measuring the current value after 10 seconds. I asked. Volume resistivity is 1 × 10 ^8.0 Ωcm
Met.

-Preparation of Image Forming Apparatus- The image forming apparatus of the second embodiment incorporating the obtained intermediate transfer drum was prepared.

<Evaluation of Transferability> After the obtained image forming apparatus was left in an environment of a temperature of 45 ° C. and a humidity of 85% for one week, an image was recorded and the transferability was evaluated. The transferability was evaluated for transfer uniformity (transfer unevenness), toner scattering, line image dropout, and nip deformation. A level having no problem in image quality was evaluated as "good", and a problematic level was evaluated as "x". . Also, the photoreceptor and the intermediate transfer drum are 50g.
/ Cm linear pressure. The evaluation was performed with an average particle size of 7.5 μm.
m of toner was used. The results are shown in Table 1 below.

(Example 2) In the preparation of the intermediate transfer drum of Example 1, except that when the surface layer was formed, it was held and cured at 150 ° C for 30 minutes instead of being held and cured at 180 ° C for 30 minutes. An intermediate transfer drum was manufactured in the same manner as in Example 1. When measured in the same manner as in Example 1, the volume resistivity was 5 × 10 ^8.0 Ωcm. Next, Example 1
An image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1 below.

(Example 3) In the production of the intermediate transfer drum of Example 1, when forming the rubber elastic layer, the conductive liquid silicone rubber used had a JIS-A hardness of 30 degrees and a compressive strain of 2%. Low volume curing type volume resistivity of 10 ⁶
When forming the surface layer instead of the conductive liquid silicone rubber of Ωcm, instead of holding and curing at 180 ° C. for 30 minutes, instead of holding and curing at 150 ° C. for 30 minutes, in the same manner as in Example 1, An intermediate transfer drum was manufactured. Example 1
As a result, the volume resistivity was 5 × 10 ^9.0 Ω.
cm. Next, an image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1 below.

(Comparative Example 1) In the production of the intermediate transfer drum of Example 1, when forming the surface layer, instead of using JYL841 manufactured by Acheson Japan, carbon black and fluororesin were fluorinated to fluororubber. Spray the latex with particles and hardener, and allow
After leaving it for 0 minutes and then pre-drying in an atmosphere of 50 ° C. for 30 minutes, it was kept at 230 ° C. for 30 minutes to be cured, and the thickness 2
An intermediate transfer drum was produced in the same manner as in Example 1 except that a surface layer of 0 μm was formed. The volume resistivity of the obtained intermediate transfer drum was determined by pressing the intermediate transfer drum against a metal plate under a load of 1 kg, applying a voltage of 500 V to the metal plate and the metal base material of the intermediate transfer drum, and measuring the volume resistivity after 10 seconds. It was determined from the current value. The volume resistivity was 1 × 10 ^8.0 Ωcm. Next, an image forming apparatus was manufactured in the same manner as in the first embodiment.
The same evaluation was performed. The results are shown in Table 1 below.

(Comparative Example 2) In the preparation of the intermediate transfer drum of Comparative Example 1, except that when forming the surface layer, instead of holding and curing at 230 ° C. for 30 minutes, it was held and cured at 280 ° C. for 30 minutes. An intermediate transfer drum was manufactured in the same manner as in Comparative Example 1. When measured in the same manner as in Comparative Example 1, the volume resistivity was 1 × 10 ¹⁰ Ωcm. Next, an image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1 below.

(Comparative Example 3) In the production of the intermediate transfer drum of Example 1, when forming the surface layer, instead of using JYL841 manufactured by Acheson Japan, a urethane-based paint was applied by spraying, and the temperature was kept at room temperature for 10 minutes. Leave it, then
After preliminary drying in an atmosphere of 50 ° C. for 30 minutes, an intermediate transfer drum was manufactured in the same manner as in Example 1 except that the surface layer having a thickness of 20 μm was formed by holding at 120 ° C. for 30 minutes and curing. When measured in the same manner as in Comparative Example 1, the volume resistivity was 1 × 10 ¹⁰ Ωcm. Next, an image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1 below.

Comparative Example 4 A metal substrate having a diameter of 32 mm was
5m thick with conductivity added by adding carbon black
m of ethylene propylene sponge rubber
A 2 mm roller was used, and a conductive fluorine film (polyvinylidene fluoride) having a thickness of 40 μm was adhered onto the roller to produce an intermediate transfer drum. When measured in the same manner as in Comparative Example 1, the volume resistivity was 1 × 10 ^9.0 Ω · cm. Next, an image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1 below.

[0065]

[Table 1]

From the results shown in Table 1, the image forming apparatuses of Examples 1 to 3 according to the present invention have excellent transferability. on the other hand,
In Comparative Examples 1 and 2, the surface roughness of the transfer surface (surface layer) was large, and image quality defects such as scattering of toner and uneven transfer occurred in transferability. Comparative Example 3
In Example 2, stick slip occurred between the transfer member and the photosensitive member due to a large friction coefficient of the transfer surface, and transfer unevenness occurred. Also,
In Comparative Example 4, uneven streaks occurred at a contact position between the image carrier and the intermediate transfer drum, which were considered to be caused by a step due to compression set.

(Example 4) -Preparation of Intermediate Transfer Belt- [Preparation of Substrate] In a polyimide U varnish A for heat-resistant film manufactured by Ube Industries, Ltd., 100 parts of resin component and 16 parts of carbon black were mixed by a mixer. Mixed. The obtained base material forming solution is poured into a cylindrical mold, and the temperature is raised stepwise from 100 ° C. to 200 ° C. and heated, and 500 to 2000 rpm.
The cylindrical mold was rotated at the number of revolutions, and a film was formed by a centrifugal molding method. Next, the resulting semi-cured film is subjected to a polyimide-forming reaction (ring-closing reaction of polyamic acid) at a high temperature of 350 ° C. to be fully cured, and has a surface resistivity of 1 × 10 ^11.7 Ω / □ and a volume resistivity. Rate is 1 × 10 ^9.8
Ωcm, thickness 90 μm, width 350 mm, outer diameter 16
A polyimide endless belt as a base material of 8 mm was produced.

[Formation of Surface Layer] On the surface of the obtained polyimide endless belt, an acrylic resin and a urethane resin (40 parts: 60 parts) having silicon as a terminal group, a conductive agent (2% by weight) and a fluororesin powder ( JYL841 manufactured by Acheson Japan Co., Ltd. (30% by weight) dispersed therein, spray-coated, allowed to stand at room temperature for 10 minutes, then pre-dried in a 50 ° C. atmosphere for 30 minutes, and then held at 180 ° C. for 30 minutes to cure. Let
An intermediate transfer belt (intermediate transfer member) having a surface layer having a thickness of 20 μm was prepared.

Table 2 shows the measurement results of the surface resistivity, volume resistivity, friction coefficient, and surface roughness of the obtained intermediate transfer belt. The surface resistivity of the obtained intermediate transfer belt is 1
× 10 ^11.9 Ω / □ and volume resistivity was 1 × 10 ^10.5 Ωcm. The surface resistivity and the volume resistivity were measured by the following methods.

<Surface Resistivity> As described above, the surface resistivity was measured using the circular electrode (HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.) as shown in FIG. A voltage of 100 (V) was applied between the columnar electrode portion C and the ring-shaped electrode portion D in the above, and the current value was obtained after 10 seconds.

<Volume Resistivity> As described above, the volume resistivity was measured using the circular electrode (HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.) as shown in FIG. A voltage of 100 (V) was applied between the columnar electrode portion C ′ and the second voltage application electrode B ′ in the ′ ′, and the current value was obtained after 30 seconds.

-Preparation of Image Forming Apparatus- The image forming apparatus of the first embodiment incorporating the obtained intermediate transfer belt was prepared.

<Evaluation of Transferability> Images were recorded by the obtained image forming apparatus, and the transferability was evaluated. The transferability was evaluated with respect to the lack of a line image and the uniformity of transfer, and a level having no problem in image quality was judged as ○, and a level having a problem was judged as ×. For evaluation, a toner having an average particle size of 7.5 μm was used. The results are shown in Table 2 below.

(Comparative Example 5) In the production of the intermediate transfer belt of Example 4, when forming the surface layer, instead of using JYL841 manufactured by Acheson Japan Ltd., carbon black and fluororesin obtained by fluorinating fluororubber were used. Latex containing particles and a curing agent (GL manufactured by Daikin Industries, Ltd.)
S-213) was spray-coated, allowed to stand at room temperature for 10 minutes, and then pre-dried in a 50 ° C. atmosphere for 30 minutes, and then held and cured at 230 ° C. for 30 minutes to form a 20 μm thick surface layer. An intermediate transfer belt was produced in the same manner as in Example 4. When measured in the same manner as in Example 4, the surface resistivity of the obtained intermediate transfer belt was 1 × 10
^12.1 Ω / □, and volume resistivity was 1 × 10 ^10.8 Ωcm. Next, an image forming apparatus was manufactured in the same manner as in Example 4, and the same evaluation as in Example 4 was performed. The results are shown in Table 2 below.

(Comparative Example 6) In the production of the intermediate transfer belt of Example 4, when forming the surface layer, instead of using JYL841 manufactured by Nippon Acheson Co., Ltd., carbon black and fluororesin were fluorinated to fluororubber. Latex containing particles and a curing agent (GL manufactured by Daikin Industries, Ltd.)
S-213) was spray-coated, allowed to stand at room temperature for 10 minutes, and then pre-dried in a 50 ° C. atmosphere for 30 minutes, and then held and cured at 230 ° C. for 30 minutes to form a 20 μm thick surface layer. An intermediate transfer belt was produced in the same manner as in Example 4. When measured in the same manner as in Example 4, the surface resistivity of the obtained intermediate transfer belt was 1 × 10
^12.4 Ω / □ and volume resistivity was 1 × 10 ^11.8 Ωcm. Next, an image forming apparatus was manufactured in the same manner as in Example 4, and the same evaluation as in Example 4 was performed. The results are shown in Table 2 below.

(Comparative Example 7) In preparing the intermediate transfer belt of Example 4, when forming the surface layer, instead of using JYL841 manufactured by Acheson Japan, a silicone-based paint (manufactured by Dow Corning Toray Silicone Co., Ltd.) was used. SR241
An intermediate transfer belt was produced in the same manner as in Example 4 except that 1) was used. When measured in the same manner as in Example 4,
The surface resistivity of the obtained intermediate transfer belt is 1 × 10 ^11.6 Ω.
/ □, volume resistivity was 1 × 10 ^10.2 Ωcm. Next, an image forming apparatus was manufactured in the same manner as in the fourth embodiment.
The same evaluation was performed. The results are shown in Table 2 below.

(Comparative Example 8) In the preparation of the intermediate transfer belt of Example 4, when forming the surface layer, instead of using JYL841 manufactured by Acheson Japan, a urethane-based paint was spray-applied and allowed to stand at room temperature for 10 minutes. Leave it, then
After preliminary drying in an atmosphere at 50 ° C. for 30 minutes, an intermediate transfer belt was produced in the same manner as in Example 4 except that the surface layer having a thickness of 30 μm was formed by curing at 120 ° C. for 30 minutes. When measured in the same manner as in Example 4, the surface resistivity of the obtained intermediate transfer belt was 1 × 10 ^11.1 Ω / □, and the volume resistivity was 1 × 10 ^10.1 Ωcm. Next, Example 4
An image forming apparatus was manufactured in the same manner as in Example 1, and the same evaluation as in Example 4 was performed. The results are shown in Table 2 below.

[0078]

[Table 2]

The results shown in Table 2 indicate that the image forming apparatus of the present invention of Example 4 has excellent transferability. On the other hand, in Comparative Examples 5 and 6, the surface roughness of the transfer surface was large, and image quality defects such as uneven transfer occurred in transferability. Further, in Comparative Examples 7 and 8, stick slip occurred between the transfer member and the photosensitive member due to a large friction coefficient of the transfer surface, and a dropout of a line image occurred.

[0080]

According to the present invention, it is possible to provide an image forming apparatus having a high transfer efficiency and capable of stably supplying a high-quality image which does not cause a hollow phenomenon.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a color image forming apparatus according to a first embodiment using a belt-shaped intermediate transfer member.

FIG. 2 is a schematic diagram illustrating a color image forming apparatus according to a second embodiment using a drum-shaped intermediate transfer member.

FIG. 3 is a schematic diagram illustrating a color image forming apparatus according to a third embodiment using a drum-shaped intermediate transfer member.

FIG. 4 is a schematic configuration diagram illustrating an example of an intermediate transfer drum in the present invention.

FIG. 5 is a schematic configuration diagram of a static friction coefficient meter.

FIG. 6 is a diagram showing a method of measuring surface resistivity.

FIG. 7 is a diagram showing a method of measuring volume resistivity.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 photoconductor drum (image carrier) 2 intermediate transfer belt (intermediate transfer member) 3 bias roller 4 paper tray 5 black developing device 6 yellow developing device 7 magenta developing device 8 cyan developing device 9 intermediate transfer member cleaner 10 transfer roller 13 peeling Claw 21 Belt roller 22 Backup roller 23 Belt roller 24 Belt roller 25 Conductive roller 26 Electrode roller 31 Cleaning blade 41 Recording paper 42 Pickup roller 43 Feed roller T Toner image 101 Photoconductor (image carrier) 101 (K, Y, M) , C) Black, yellow, magenta, cyan photoconductor 102 Charger 102 (K, Y, M, C) Black, yellow, magenta, cyan charger 103 Cleaning device 104a Image writing device 104b Scanning exposure 104 (K, Y , M, C) Black, yellow, magenta, cyan image writing device 105 (K, Y, M, C) black, yellow, magenta, cyan developing device 106 transfer roller 107 fixing device 108 static elimination lamp 109 paper transport roller 110 intermediate transfer drum (intermediate) Transfer member) 110 (A, B) first intermediate transfer drum (intermediate transfer member) 110C second intermediate transfer drum (intermediate transfer member) 111 recording material 201 surface layer 202 intermediate layer 203 rubber elastic layer 204 base material 301 surface Layer material 302 Fixed base 303 Steel ball 304 Balance for zero adjustment 305 Load cell 306 Load

Claims (7)

[Claims] 1. An image forming apparatus having an intermediate transfer member, wherein the intermediate transfer member has a surface layer containing a resin having silicon as a terminal group. 2. The image forming apparatus according to claim 1, wherein the surface layer of the intermediate transfer body contains a fluororesin powder. 3. The image forming apparatus according to claim 1, wherein the surface layer of the intermediate transfer member contains a conductive agent. 4. The friction coefficient of the surface layer of the intermediate transfer member is as follows:
The image forming apparatus according to claim 1, wherein the ratio is 0.5 or less. 5. The surface roughness of a surface layer of the intermediate transfer member is as follows:
The image forming apparatus according to claim 1, wherein Rz (10-point average roughness) is 1.5 μm or less. 6. The intermediate transfer body has a metallic cylindrical substrate and two or more layers on the cylindrical substrate, and a layer in contact with the cylindrical substrate has a JIS-A hardness of 30 degrees or less. The image forming apparatus according to claim 1, further comprising an elastic material having a compressive strain of 5% or less and a layer thickness of 3 to 10 mm. 7. An image forming apparatus including a charging member, wherein the charging member has a surface layer containing a resin having silicon as a terminal group.