JP2001201948A - Semiconductive belt, and image forming device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductive belt with less resistance variation due to an applied voltage or the expansion and contraction at a supporting roll part, etc., and to provide an image forming device capable of stably obtaining an image of high image quality. SOLUTION: In the semiconductive belt a relation between an initial volume resistivity ρv1 (Ω cm) and a volume resistivity ρv2 (Ω cm) after applying a tensile repeated distortion of 3% 10,000 times satisfies the following expression (1); (1) |logρv1-logρv2|<=0.5 and the image forming device is equipped with the belt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
The present invention relates to a semiconductive belt used for a belt transfer, a toner image transfer, a sheet conveyance portion, and the like in an image forming apparatus using an electrophotographic method, such as a printer, a facsimile, and a multifunction peripheral thereof.

[0002]

2. Description of the Related Art Conventionally, as a transfer / transport belt for image formation used in a transfer / transport device of an image forming apparatus,
Elastic materials such as rubber and thermoplastic elastomers have been proposed because of the ease of control during belt driving. For example,
JP-A-2-10389 proposes a belt using a thermoplastic elastomer. However, a belt made of a thermoplastic elastomer is liable to be deformed due to the properties of the material, and if the belt is movably stretched between roll-shaped supports, it is considered that the belt has been stopped for a long time. Deformation is likely to occur following the curvature of the support, and there is a problem that the transfer material may not be stably conveyed due to electrostatic attraction.

Further, Japanese Patent Application Laid-Open No. 2-264277 proposes to use a belt in which a polyethylene film is laminated on EPDM rubber having a volume resistivity of 10 ¹⁵ to 10 ¹⁶ Ωcm. Further, Japanese Patent Application Laid-Open No. 63-83764 proposes a belt using an elastic material as a material having a volume resistivity of about 10 ¹⁰ to 10 ¹³ Ωcm. This belt is
Since the material is an elastic body, it has a higher tensile strength than the elastomer. Here, a transfer belt for image formation is required to have not only high tensile strength but also a predetermined paper passing durability. This paper passing durability is obtained by setting the thickness of the belt to a predetermined thickness.

In order to obtain the high tensile strength and the predetermined paper-passing durability, a transfer / conveying belt having a volume resistivity of 10 ¹⁵ to 10 ¹⁶ Ωcm described in JP-A-2-264277 is disclosed. In the case of using a belt having a high volume resistivity of about 10 ¹⁰ to 10 ¹³ Ωcm, such as the transfer conveyance belt described in JP-A-63-83764,
There is a problem that an electric field required for transfer increases and a load on a power supply for applying a voltage to the belt increases. Further, since the transfer conveyance belt holds the transfer material via electrostatic attraction, discharge may occur when the transfer material is separated from the belt. In this case, the transfer image on the transfer material may be disturbed. This discharge tends to occur particularly in a low-temperature and low-humidity environment. However, when a belt having a high volume resistivity is used as the transfer conveyance belt, a discharge is likely to occur because the belt needs a high voltage to hold the transfer material. A part of the upper toner becomes reverse polarity, and a transfer failure occurs, and an image defect such as a partial white spot occurs on the transfer material. Therefore, the transfer image is likely to be disturbed, and it is difficult to obtain good image quality. is there.

Further, the volume resistivity of the transfer / conveying belt is set to 10
If it is less than ⁸ Ωcm, there is a problem that it becomes difficult to hold the transfer material via electrostatic attraction because the charge easily flows.

Japanese Patent Application Laid-Open No. 8-185068 discloses a transfer conveyance.
As a belt, the volume resistivity is 10 ⁹Ωcm or less
The surface of an elastic body such as chloroprene rubber is coated with nylon.
Or a belt of urethane coat has been proposed. Chloro
When the surface layer is coated with nylon resin on plain rubber
Has a hard coat layer, so it supports roll shape
Follow the transfer belt deformation at the curvature of the body
Can cause cracks in the surface layer.
Live. In the case of a urethane coat, the coat layer
Of the coating layer described above.
There is no problem of racking, but toner adheres easily and becomes dirty.
Have problems such as being apt to be disturbed.

In the case where an elastic material such as chloropyrene rubber in which carbon black or the like is dispersed is used as the transfer / conveying belt, a semiconductive resistance region at the level of 10 ⁹ Ωcm is a region where resistance control is difficult. Therefore, it is almost impossible to stably obtain a desired resistance value by adding ordinary conductive carbon black to ordinary rubber material. One-digit variation in resistance of the elastic belt (logΩcm
Value), it is difficult to stably manufacture the transfer voltage, and if the in-plane variation of the resistance is greater than one digit, the transfer voltage cannot be applied uniformly, so that the transfer image quality is not stable.

Further, the belt holds the transfer material and applies a transfer voltage of 1 kV to 5 KV in order to transfer the toner image to the transfer material. The applied voltage changes the resistance value of the belt material. There has been a problem that the resistance value changes between a portion having a transfer material and a portion having no transfer material.

In Japanese Patent Application Laid-Open No. 8-292648, in order to improve the aging of the resistance of the belt material and the unevenness of the belt resistance, the transfer / conveying belt is made up of three layers and the volume resistivity of the first layer (surface layer) is reduced. 1 × 10 ¹⁰ to 1 × 10 ¹⁶ Ω
cm, and the second layer (intermediate layer) has a volume resistivity of
Using a rubber layer utilizing the conductivity of the polymer itself in the range of 1 × 10 ⁷ to 1 × 10 ¹⁰ Ωcm, the volume resistivity of the third layer (base layer) is set in the range of 1 × 10 ¹⁰ to 1 × 10 ¹⁶ Ωcm. Proposals have been made. It is stated that the resistance unevenness can be improved by the rubber layer utilizing the conductivity of the polymer itself of the second layer (intermediate layer), but in the case of a laminated belt, the resistance value is dominated by the layer having the higher resistance. However, the improvement of the resistance unevenness was not sufficient.

Japanese Patent Application Laid-Open No. Hei 9-179414 proposes a rubber material composed of chloroprene rubber and EPDM (ethylene propylene diene monomer) as a measure against the aging of the resistance of the belt material. It was not sufficient to improve the variation over time of the resistance and the unevenness of the belt resistance.

As measures against the above-mentioned fluctuation of the resistance of the belt material with time and unevenness of the belt resistance, Japanese Patent Application Laid-Open No.
No. 04 proposes to use a rubber material of a strong polarity such as hydrin rubber and use an ion conductive type rubber material. However, when using an electron conductive type rubber material using a conductive agent such as carbon black,
Although there is no problem of the resistance value changing in an environment of high temperature and high humidity and low temperature and low humidity, the ion conduction type has a problem that the resistance value changes by one digit or more in an environment of high temperature and high humidity and low temperature and low humidity.

[0012] Further, there is no prior art in a material system using a conductive agent such as carbon black in which the resistance of a belt material is changed over time and the resistance is changed by repeated tensile strain.

[0013]

As described above, in the prior art, the resistance value of the belt material is 10 ⁸ Ωcm to 10 ¹¹ Ωcm where the transfer image on the transfer material is not disturbed. There is a problem that the in-plane variation is large and the resistance of a part of the belt material is changed by the transfer voltage. In particular, if the change in the belt resistance due to the transfer voltage (applied voltage) or the like is large, there is a problem in that good image quality cannot be stably obtained because transfer failure occurs partially.

A complicated exchange of the belt material due to a change in the resistance of a part of the belt material due to the transfer voltage is not preferable because it leads to an increase in maintenance time and running costs.

Conventionally, full-color copying machines and printers intended for some corporate users at a high price have been used for a wider range of users including small and medium-sized offices and ordinary households. For full-color copiers and printers for these users, the size and cost of the main unit must be reduced more than ever, and it is even more important to reduce maintenance work and associated running costs. Therefore, extending the life of the belt material is a major improvement task.

An object of the present invention is to solve the above conventional problems and achieve the following objects. That is, the present invention provides a semiconductive belt having a small resistance change amount due to an applied voltage or expansion and contraction at a support roll portion, and an image forming apparatus capable of stably obtaining a high quality image. With the goal.

[0017]

Means for Solving the Problems The inventors of the present invention have found that if the amount of resistance change in the semiconductive belt when the amount of repetitive strain is given is large, the applied voltage in repeated use (actual use), The present inventors have found that the amount of change in resistance due to expansion and contraction of the film is large, and have reached the present invention. That is,
The present invention

<1> Initial volume resistivity ρv1 (Ωcm)
And a volume resistivity .rho.v2 (.OMEGA.cm) after applying a tensile repetitive strain of 3% 10,000 times (10K) times satisfies the following expression (1).

Equation (1) | logρv1-logρv
2 | ≦ 0.5

<2> Initial volume resistivity is 10 ⁸ Ωcm
The semiconductive belt according to the item <1>, wherein the thickness is from 10 to 10 ¹¹ Ωcm.

<3> The semiconductive belt according to <1> or <2>, wherein the semiconductive belt contains at least two kinds of incompatible materials.

<4> The semiconductive belt according to any one of <1> to <3>, further comprising a surface coat layer, wherein the surface coat layer is made of a material having a low surface energy. It is.

<5> The semiconductive belt according to <4>, wherein the low surface energy material is a material in which fluororesin particles are dispersed.

<6> An image forming apparatus provided with a transfer / conveying belt for conveying a transfer object in a transfer area for transferring a toner image onto a transfer object, wherein the transfer / conveyance belt is the above-described <1>.
An image forming apparatus comprising the semiconductive belt according to any one of <1> to <5>.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The semiconductive belt of the present invention has an initial volume resistivity ρv1 (Ωcm) and a volume resistivity ρ after a tensile repetitive strain of 3% is given 10,000 (10K) times.
The relationship with v2 (Ωcm) satisfies the following expression (1), preferably the following expression (1-A), and more preferably the following expression (1-B). Note that the volume resistivity ρv1 and the volume resistivity ρv
2 is the volume resistivity in the thickness direction.

Equation (1) | logρv1-logρv2 | ≦ 0.5 Equation (1-A) | logρv1-logρv2 | ≦ 0.4 Equation (1-B) | logρv1-logρv2 | ≦ 0.3

In the semiconductive belt of the present invention, if the change in volume resistivity is out of the range of the above-mentioned expression (1), the applied voltage, the amount of resistance change due to expansion and contraction at the support roll portion, and the like become large. The service life in use (actual use) is shortened. Generally, a semiconductive belt has a configuration in which a conductive agent is dispersed in a binder resin. Therefore, in the semiconductive belt of the present invention, by satisfying the above expression (1), it is considered that the formation of a new conductive path due to a change in the resistance of the binder resin itself or a change in the dispersion state of the conductive agent is suppressed. .
Selection of various materials such as binder resin, conductive agent and the like constituting the semiconductive belt of the present invention and adjustment of the blending amount / dispersion condition, layer constitution,
Further, the volume resistivity change in the semiconductive belt of the present invention can be adjusted to a range satisfying the above-described formula (1) by means such as optimization of the manufacturing method.

In the semiconductive belt of the present invention, the tensile repetition strain of 3% means that a sheet (semiconductive belt) cut to a width of 50 mm and a length of 200 mm is placed between chucks 15.
Attach it to the tensile tester at 0 mm
4.5 mm (3% strain) and 150 mm are alternately changed at a chuck speed of 12 mm / min to show the amount of strain.

In the semiconductive belt of the present invention, the volume resistivity is determined by using a circular electrode (for example, Hiresta I manufactured by Mitsubishi Yuka).
P HR probe) according to JIS K6991. Specifically, for example, it can be measured using the circular electrode shown in FIG. FIG. 2 is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of the circular electrode shown in FIG. The circular electrode shown in FIG. 1 includes a first voltage applying electrode A and a second voltage applying electrode B. The first voltage applying electrode A has a cylindrical electrode C and a cylindrical ring-shaped electrode part D having an inner diameter larger than the outer diameter of the cylindrical electrode C and surrounding the cylindrical electrode part C at regular intervals. And A semiconductive belt T is sandwiched between the cylindrical electrode portion C and the ring-shaped electrode portion D of the first voltage applying electrode A and the second voltage applying electrode B, and the cylindrical electrode portion C of the first voltage applying electrode A is sandwiched. A current I (A) flowing when a voltage V (V) is applied between the second voltage applying electrode B and the second voltage applying electrode B is measured.
The volume resistivity ρv (Ωcm) of the semiconductive belt T can be calculated. Here, in the following equation (2), t indicates the thickness of the semiconductive belt T.

Equation (2) ρv = 19.6 × (V / I) × t

The semiconductive belt of the present invention has an initial volume resistivity of 10 ⁸ Ωcm to 10 ¹¹ Ωcm, preferably 10 ⁹ Ωcm.
Ωcm to ^{10 10} Ωcm is preferable from the viewpoint that the transfer material can be satisfactorily and stably held through electrostatic attraction. This initial volume resistivity is 10 ⁸ Ω
If it is less than cm, the charge tends to flow easily, so that it may not be possible to hold the transfer material via electrostatic attraction. On the other hand, if it exceeds 10 ¹¹ Ωcm, a discharge is likely to occur because the belt requires a high voltage to hold the transfer material, and this discharge phenomenon causes a part of the toner on the transfer material to have a reverse polarity, resulting in poor transfer. Occurs, and image defects such as partial white spots occur on the transfer material. Therefore, the transferred image is likely to be disturbed, and it may be difficult to obtain good image quality.

Hereinafter, the configuration of the semiconductive belt of the present invention will be described in detail. The semiconductive belt of the present invention preferably comprises an elastic layer containing a binder resin and a conductive agent. In the semiconductive belt of the present invention, the elastic layer may be composed of a single layer or a plurality of layers. In addition, a configuration in which a surface coat layer is provided on the surface of the elastic layer as necessary may be employed.

As the binder resin, rubber materials (for example, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene,
Butyl rubber, silicone rubber, a rubber blend material obtained by blending two or more of these, and a resin material (eg, polyester, polyether ether ketone, polyamide, polycarbonate, polyvinylidene fluoride, and a blend of two or more of these) And a rubber-resin blend material obtained by blending two or more of these. However, polyether ether ketone, polycarbonate,
Use of polyvinylidene fluoride alone is not preferred because cracks may occur when the above-described tensile repetitive strain is given.

As the conductive agent, carbon black (for example, furnace black, acetylene black, ketchen black, channel black, etc.) which is generally advantageous in terms of cost and the like is used. , A surfactant, a conductive polymer and the like. These conductive agents can be used alone or in combination of two or more.

Examples of the metal include graphite, aluminum, nickel, copper, and alloys thereof. Examples of the metal oxide include tin oxide, zinc oxide, kalim titanate, tin oxide-indium oxide, and tin oxide-antimony oxide composite oxide. Examples of the surfactant include a surfactant such as a sulfonate or an ammonium salt, and various surfactants such as a cationic, anionic, and nonionic surfactant. Examples of the conductive polymer include, for example, various (eg, styrene) copolymers of (meth) acrylate binding a quaternary ammonium base to a carboxyl group, and copolymers of maleimide and methacrylate binding a quaternary ammonium base, etc. Of 4
Examples of the polymer include a polymer that binds a quaternary ammonium base, a polymer that binds an alkali metal salt of sulfonic acid such as sodium polysulfonate, and a polymer that binds at least a hydrophilic unit of an alkyl oxide in a molecular chain. Specific examples of the conductive polymer include, for example, polyethylene oxide, polyethylene glycol-based polyamide copolymer, polyethylene oxide-epichlorohydrin copolymer, polyether amide imide, a block polymer having a polyether as a main segment, and Examples thereof include polyaniline, polythiophene, polyacetylene, polypyrrole, polyphenylenevinylene, and the like. These conductive polymers can be used in a undoped state or a doped state.

It is preferable to use two or more conductive agents having different characteristics in combination, from the viewpoint of stably obtaining a specific volume resistivity.

When two or more carbon blacks are used in combination as two or more conductive agents, it is preferable to use two or more carbon blacks having different DBP oil absorption properties. By using two or more types of carbon blacks having different DBP oil absorptions at a specific ratio, it is possible to suppress a rapid change in volume resistance (for example, a region of 10 ⁸ to 10 ¹⁰ Ωcm), and to use a relatively small amount. Conduction with less variation is possible.

In the material composition of the semiconductive belt to which carbon black is added, carbon black tends to bond in a chain shape, and the resistance value differs depending on the length of the chain bond. That is, the longer the chain bond, the higher the conductivity of the material of the semiconductive belt and the lower its resistance. On the other hand, if the chain bond is short, the conductivity decreases and the resistance value increases. Therefore, when carbon black that forms a long chain bond is added to the material composition, the resistance value greatly changes as compared with the case where the same amount of carbon black that forms a short chain bond is added. .

Here, the length of the above-mentioned chain bond depends on the particle size and surface activity of the individual particles of carbon black, and one of the indicators indicating this is ASTM (American Standard Test Method) D2414-. DBP defined in 6TT
There is oil absorption. This DBP oil absorption refers to dibutyl phthalate (DBP) absorbed by 100 g of carbon black.
It is considered that carbon black having a higher DBP oil absorption amount forms a longer chain bond.

If the resistance value of the semiconductive belt is adjusted by adding only carbon black having a high DBP oil absorption, the resistance value tends to greatly change even if the addition amount is slightly increased or decreased. In some cases, the target resistance value cannot be given to the semiconductive belt unless the addition amount of S is strictly defined.

If the resistance value of the semiconductive belt is controlled by adding only carbon black having a low DBP oil absorption, the rate of change of the resistance with the increase / decrease of the addition amount is small, and the high DBP oil absorption is high. Compared to the case where only carbon black is added, carbon black is more easily dispersed in the material composition almost uniformly, and the above-mentioned problem is more easily avoided. However, in order to provide a desired resistance value to the semiconductive belt,
A larger amount of carbon black is often added than when only carbon black having a high DBP oil absorption is added, and the compounding ratio of carbon black in the material composition tends to increase. When a rubber material is used, when kneading with a Banbury mixer, a kneader, or the like, processing may be difficult due to high viscosity.

For this reason, it is preferable to use two or more carbon blacks having different DBP oil absorbing properties.

Two or more types of carbon blacks having different DBP oil absorbing properties may be used as long as there is a difference between these DBP oil absorbing properties, but if the difference is too small, one type of carbon black may be used. The same problem as when black is added may occur. Therefore, D
Two or more types of carbon blacks having different BP oil absorption properties
It is preferable that there is some difference between the DBP oil absorptions. Specifically, it is preferable that the carbon black having a high DBP oil absorption has a DBP oil absorption of 250 ml / 100 g or more, and the carbon black having a low DBP oil absorption has a DBP oil absorption of 100 ml / 100 g or less.

Examples of carbon black having a high DBP oil absorption include granular acetylene black (oil absorption: 288 ml / 100 g) manufactured by Electrochemical Co., Ltd., Ketchen Black (oil absorption: 360 ml / 100 g) manufactured by Lion Aguso, and Cabot Corporation. Vulcan XC-72 (oil absorption 265m)
1/100 g), and HS-500 (oil absorption: 477 ml / 100 g) manufactured by Asahi Carbon Co., Ltd. DBP
Asahi Carbon FT's Asahi Thermal FT (oil absorption 28 ml / 100
g), Asahi Thermal MT manufactured by Asahi Carbon Co., Ltd. (oil absorption: 35 ml / 100 g). As a combination of two or more kinds of carbon blacks having different DBP oil absorbing properties, when two kinds are used in combination, granular acetylene black (oil absorption amount 288 ml / 100 g) manufactured by Electrochemical Co., Ltd. as a carbon black having a high DBP oil absorption, and DBP oil absorption A combination of Asahi Carbon Co., Ltd. Asahi Thermal FT (oil absorption: 28 ml / 100 g) is preferably used as a low-carbon black.

The semiconductive belt of the present invention has at least 2
It is preferable to include various types of incompatible materials. Specifically, for example, from the viewpoint of containing at least two types of incompatible binder resins, the dispersion state of the conductive agent is improved, and a specific volume resistivity can be stably obtained. preferable.

The at least two incompatible binder resins are combinations of binder resins having a difference in solubility parameter δ (SP value). Here, the difference in solubility parameter δ (SP value) is, for example, 1.3 J ^1/2 cm ^2/3.
It is preferable to have the above.

The solubility parameter δ (SP value) is represented by the following equation (3). In the following formula (3), δ2d, δ2
p ′ and δ2h are SP values due to dispersive force, polar effect, and hydrogen bond, respectively. In general, the solubility parameter δ
(SP value) represents the cohesive energy as E (cal = 4.18).
68J), assuming that the molecular volume is Vm, δ = (E / Vm) 1
/ 2, which indicates that the greater the value of δ, the greater the polarity.

Equation (3) δ = δ2d + δ2p ′ + δ2h

As rubber materials having a large SP value, polyurethane (SP value = 10), chlorinated polyisoprene (SP
Value = 9.35), NBR (SP value = 9.3), and chloropyrene rubber (SP value = 8.71). As a rubber material having a small SP value, EPDM (SP value = 8.
0), hydrogenated polybutadiene (SP value = 8.08),
Butyl rubber (SP value = 7.85), silicone rubber (S
P value = 7.45). As a resin material having a large SP value, polyacrylonitrile (SP value = 13.5)
5), polyvinyl alcohol (SP value = 12.60),
Epoxy resin (SP value = 10.9), polyvinyl chloride (SP value = 9.74), polyvinyl acetate (SP value = 9.
57) and polystyrene (SP value = 9.03). As resin materials having a small SP value, polyethylene (SP value = 7.88), polyisobutylene ((SP value =
7.7) Polytetrafluoroethylene (SP value = 6.2).

When at least two kinds of incompatible binder resins are used in combination, a phase having a sea phase and an island phase is obtained because they do not mix with each other. For this reason, when the conductive agent is dispersed in at least two types of incompatible binder resins, the conductive agent is separated into a phase containing a small amount of the conductive agent and a phase containing a large amount of the conductive agent. A dispersed conductive phase is obtained.
That is, the conductive agent is densely dispersed only at the interface between the two types of binder resins to be in a non-uniform dispersion state, and the dense portion contributes to conductivity, so that the amount of the conductive agent can be reduced,
In addition, a stable conductive path can be formed. further,
When the amount of the conductive agent increases, the belt hardness of the elastic body increases, but since the amount of the conductive agent can be reduced,
An increase in belt hardness can be suppressed. At least 2
By adjusting the mixing ratio of the types of incompatible binder resins and the amount of the conductive agent, the desired volume resistivity (for example, 1) is obtained.
0 ⁸ to 10 ¹¹ Ωcm) can be stably obtained.

FIG. 2 shows EPDM (SP value = 8.0) and N
The schematic diagram which shows the dispersion state of carbon black in the binder resin incompatible with BR (SP value = 9.3) is shown.
As shown in FIG. 2, N having an affinity for carbon black
By blending BR with EPDM having poor compatibility with NBR, a phase having a sea phase (EPDM) and an island phase (NBR) is present, and a phase (EPDM) containing a small amount of carbon black is contained. A phase in which carbon black is highly dispersed (NBR) is separated, and a conductive phase in which carbon black is densely dispersed is present at the interface.

The conductive belt of the present invention is preferably provided with a surface coat layer, if necessary. The surface coating layer is preferably made of a material having a low surface energy, from the viewpoint of preventing toner contamination on the semiconductive belt and preventing the transfer material from being contaminated by the toner on the belt.

As the low surface energy material, a material in which fluororesin particles are dispersed is preferable. The fluororesin particles are not particularly limited. For example, polyvinyl fluoride, PVDF, tetrafluoroethylene (TFE) resin, chlorotrifluoroethylene (CTF)
E) Resin, ETFE, CTFE-ethylene copolymer, P
FA (TFE-perfluoroalkyl vinyl ether copolymer), FEP (TFE-hexafluoropropylene (HFP) copolymer), EPE (TFE-HFP-perfluoroalkyl vinyl ether copolymer), and the like. More specifically, as TFE resin powder, KTL-50 manufactured by Kitamura Co., Ltd. having a particle size of 0.3 to 0.7 μm.
0F.

The fluororesin particles are used by being dispersed in a resin material.
Byron 30SS, Byron 200, Byron 30
Examples thereof include an aliphatic polyester resin in which polymer segments such as 0 are linearly bonded, a polyurethane resin having a soft segment in a molecule, and a fluoro rubber. Since these resin materials have flexibility in themselves, flexibility can be given to the surface coat layer, so that generation of cracks and the like can be prevented.

The surface coat layer may contain a conductive agent. Examples of the conductive agent include the conductive agents described above, and carbon black is particularly preferred from the viewpoint of cost.

The surface coat layer is formed, for example, by dispersing PTFE (polytetrafluoroethylene) resin particles and carbon black in an appropriate amount in an aliphatic polyester resin such as Byron 30SS, Byron 200, or Byron 300 manufactured by Toyobo. Emuralon 345 ESD and Emuralon JYL601ES of Acheson Japan, in which carbon black is dispersed in a water-emulsion paint containing PTFE (polytetrafluoroethylene) resin.
D, NF manufactured by Daikin Industries, Ltd. obtained by dispersing FEP (tetrafluoroethylene-hexafluoropropylene copolymer) resin particles and carbon black in fluororubber.
It can be formed by applying -940 or the like on the elastic layer.

As the coating method, a brush coating, a dipping method, a spray method, a roll coater method and the like can be adopted.
It is suitable to form a surface coat layer having a thickness of 0 μm, preferably 15 to 30 μm. When the film thickness is less than 10 μm, the semiconductive belt repeatedly presses the intermediate transfer member or the image carrier through the paper, so that the surface coat layer is worn and the elastic layer is exposed. In some cases, when the surface coat layer is formed by a coating method, it may be difficult to form a uniform film. On the other hand, when the film thickness is 6
When the thickness exceeds 0 μm, when the elastic layer is coated by a coating method, liquid dripping easily occurs on the surface, and it may be difficult to stably form a smooth and uniform coating film.

(Image Forming Apparatus) The image forming apparatus of the present invention is provided with a transfer / conveying belt for conveying the transfer object in a transfer area where the toner image is transferred to the transfer object, and the transfer / convey belt is the same as that of the present invention. It is a semiconductive belt. The transfer / transport belt electrostatically attracts and conveys the transfer material, and the transfer material is applied with a voltage by a transfer unit to be described later via the transfer / transport belt, and the toner image is transferred by an electric field due to the voltage application.

The image forming apparatus of the present invention comprises an electrostatic latent image carrier, charging means for uniformly charging the surface of the electrostatic latent image carrier, and exposing the surface of the electrostatic latent image carrier to form an electrostatic latent image. Developing means for developing an electrostatic latent image formed on the surface of the electrostatic latent image carrier using an electrostatic image developer to form a toner image, and transferring the toner image onto a transfer material Means, fixing means for fixing a toner image on the transfer-receiving material, cleaning means for removing toner and dust adhered to the electrophotographic photosensitive member, and removing the electrostatic latent image remaining on the surface of the electrostatic latent image carrier. It is provided by a known method as necessary, such as a static elimination means for removing.

As the electrostatic latent image carrier, conventionally known ones can be used, and as the photosensitive layer, known ones such as organic and amorphous silicon can be used. When the electrostatic latent image carrier is cylindrical, it can be obtained by a known manufacturing method such as extruding aluminum or an aluminum alloy and processing the surface. It is also possible to use the belt-like electrostatic latent image carrier.

The charging means is not particularly limited.
For example, a known charger such as a contact-type charger using a conductive or semi-conductive roll, brush, film, rubber blade, or the like, a scorotron charger using a corona discharge, or a corotron charger may be used. Among these, a contact-type charger is preferable because of its excellent charge compensation ability. The charging unit normally applies a direct current to the electrophotographic photoreceptor, but may apply an alternating current further superimposed. The charging can be suitably performed using the charging unit. The electrophotographic photoreceptor usually has a charge of -300 to
It is charged to -1000V.

The exposure means is not particularly limited.
For example, a semiconductor laser beam on the surface of the electrophotographic photosensitive member,
Examples include light sources such as LED light and liquid crystal shutter light, and optical devices capable of exposing these light sources to a desired image through a polygon mirror.

The developing means can be appropriately selected according to the purpose. For example, a known developing method in which a one-component developer or a two-component developer is brought into contact or non-contact with a brush or a roll for development. And the like.

As the transfer means, a transfer roll or the like is brought into thick contact with the back surface of a semiconductive belt, and a contact type transfer for transferring a toner image to a transfer target, or a non-contact transfer for transferring to a transfer target using a corotron or the like. Pattern transfer and the like. Further, the semiconductive belt of the present invention can be used as an intermediate transfer member in an intermediate transfer type image forming apparatus. In this case, the semiconductive belt is transferred to the intermediate transfer member by a first transfer unit (hereinafter, referred to as “first transfer member”). Is transferred from the intermediate transfer member to the transfer target by the second transfer means (hereinafter, may be referred to as “second transfer”).

As the first transfer means, for example, a contact-type transfer charger using a belt, a roll, a film, a rubber blade, or the like, a scorotron transfer charger using corona discharge, or a corotron transfer charger itself can be used. Known transfer chargers can be used. Among these, a contact-type transfer charger is preferable because of its excellent transfer charge compensation ability. In addition,
In the present invention, a peeling charger and the like may be used in addition to the transfer charger.

The second transfer means includes a contact transfer charger such as a transfer roll exemplified as the first transfer means, a scorotron transfer charger, a corotron transfer charger, and the like. Among these, a contact-type transfer charger is preferable as in the first transfer unit. When the contact type transfer charger such as a transfer roll is pressed strongly, an image transfer state can be maintained in a good state. Also, when a contact-type transfer charger such as a transfer roll is pressed at the position of the roll for guiding the intermediate transfer body, the operation of transferring the toner image from the intermediate transfer body to the transfer target body can be performed in a good state. become.

The light neutralizing means includes, for example, a tungsten lamp and an LED, and the light quality used in the light neutralizing process includes, for example, white light such as a tungsten lamp and red light such as an LED light. Can be The intensity of the irradiation light in the photostatic process is usually several times to 30 times the amount of light indicating the half-reduction exposure sensitivity of the electrophotographic photosensitive member.
The output is set to be about twice.

The fixing means is not particularly limited.
A fixing device known per se, for example, a hot roll fixing device, an oven fixing device and the like can be mentioned.

The cleaning means is not particularly limited, and a known cleaning device may be used.

Hereinafter, an example of the image forming apparatus of the present invention will be described. FIG. 3 and FIG. 4 are schematic configuration diagrams showing an example of the image forming apparatus of the present invention.

The image forming apparatus shown in FIG. 3 has an electrophotographic photosensitive member (electrostatic latent image carrier) 20, a recording paper transport belt (transfer transport belt) 21, and a transfer roll (bias roll as a transfer electrode). 22, a recording paper (transfer object) tray 23
And a fixing device 24. Recording paper transport belt 2
1 is provided with the semiconductive belt of the present invention.

Around the electrophotographic photosensitive member 20, there are provided a developing device 25 using B (black) toner, and an exposure device and a charging device (not shown). Electrophotographic photoreceptor 20
Are rotatably arranged in the clockwise direction of the arrow with a predetermined peripheral speed (process speed).

The recording paper transport belt 21 is
7 and 28, it is possible to rotate in the counterclockwise direction of the arrow at the same peripheral speed as that of the electrophotographic photoreceptor 20, so that a part of the intermediate portion between the support rolls 27 and 28 is in contact with the electrophotographic photoreceptor 20. Are located in

The transfer roll 22 is provided on the recording paper transport belt 2.
1 and at a position facing a portion where the recording paper transport belt 21 and the electrophotographic photosensitive member 20 are in contact with each other, and the toner is transferred via the electrophotographic photosensitive member 20 and the recording paper transport belt 21. A transfer area (nip) for transferring the image T to a recording paper (transfer material) P is formed.

The recording paper tray 23 has a pickup roll 26. The recording paper P is transported from the recording paper tray 23 to the recording paper transport belt 21 by the pickup roll 26.

The fixing device 9 is arranged so that it can be conveyed after passing through a transfer area (nip portion) between an electrophotographic photosensitive member 20 and a transfer roll 22 via a recording paper conveying belt 21.

In the image forming apparatus shown in FIG. 3, the electrophotographic photosensitive member 20 rotates in the direction of the arrow, and its surface is uniformly charged by a charging device (not shown). B (black) is applied to the charged electrophotographic photosensitive member 20 by an exposure device (not shown).
Is formed. This electrostatic latent image is developed
As a result, a toner image T that has been developed and visualized is formed. The toner image T reaches the transfer area (nip portion) where the transfer roll 22 is disposed by the rotation of the electrophotographic photosensitive member 20, and at the same time, the recording paper P electrostatically attracts to the recording paper transport belt 21. The toner image T is conveyed to the transfer area (nip portion), and the toner image T is applied to the toner image T from the transfer roll 22 by the reverse polarity. Transcribed above. The recording paper P on which the toner image T has been transferred by the transfer roll 22 is further conveyed to the fixing device 9 where fixing is performed. Thus, a desired image is formed on the recording paper P.

The image forming apparatus shown in FIG. 4 can be used as a copying machine, a laser beam printer or the like.
The image forming apparatus shown in FIG. 4 includes units Y, M, C, and Bk.
A recording paper (transfer object) transport belt 6, transfer rolls 7Y, 7M, 7C, 7Bk, a recording paper transport roll 8,
A fixing device 9 is provided. The semiconductive belt of the present invention is provided as a recording paper (transferred object) conveying belt 6.

The units Y, M, C and Bk are rotatable clockwise as indicated by arrows at a predetermined peripheral speed (process speed).
k (the flange is fixed to the electrophotographic photosensitive member, not shown). Electrophotographic photoreceptor 1Y, 1M,
Around 1C and 1Bk, a corotron charger 2Y, 2
M, 2C, 2Bk and the exposure units 3Y, 3M, 3C, 3Bk
And each color developing device (yellow developing device 4Y, magenta developing device 4M, cyan developing device 4C, black developing device 4Bk),
Electrophotographic photoreceptor cleaners 5Y, 5M, 5C, and 5Bk are arranged, respectively.

The four units Y, M, C, and Bk are arranged in parallel with the recording paper conveying belt 6 so that the units Y, M, C, and
Bk, but the units Bk, Y, C,
An appropriate order, such as the order of M, can be set according to the image forming method.

The recording paper transport belt 6 is supported by the support roll 1
By means of 0, 11, 12, and 13, the photosensitive drums 1Y, 1M, 1C, and 1Bk can be rotated in the counterclockwise direction at the same peripheral speed as that of the electrophotographic photosensitive members 1Y, 1M, 1C, and 1Bk. Parts are electrophotographic photoreceptors 1Y, 1M,
1C and 1Bk.
The recording paper transport belt 6 is provided with the belt cleaning device 1.
4 are provided.

The transfer rolls 7Y, 7M, 7C and 7Bk are
The electrophotographic photoconductor 1Y is disposed inside the recording paper conveyance belt 6 at a position facing the portion where the recording paper conveyance belt 6 and the electrophotographic photosensitive members 1Y, 1M, 1C, and 1Bk are in contact with each other. , 1M, 1C, and 1Bk, and a toner image on a recording paper (transfer material) via a recording paper transport belt 21
A transfer region (nip portion) to be transferred to P is formed.

The fixing device 9 is arranged so that it can be conveyed after passing through the respective transfer areas (nip portions) of the recording paper conveying belt 6 and the electrophotographic photosensitive members 1Y, 1M, 1C and 1Bk.

The recording paper P is transported to the recording paper transport belt 6 by the recording paper transport roll 8.

In the image forming apparatus shown in FIG. 4, in the unit Y, the electrophotographic photosensitive member 1Y is driven to rotate. In conjunction with this, the corotron charger 2Y is driven to uniformly charge the surface of the electrophotographic photosensitive member 1Y to a predetermined polarity and potential. Electrophotographic photosensitive member 1Y whose surface is uniformly charged
Next, is exposed imagewise by the exposure device 3Y to form an electrostatic latent image on the surface thereof.

Subsequently, the electrostatic latent image is transferred to the yellow developing device 4Y.
Developed by Then, a toner image is formed on the surface of the electrophotographic photosensitive member 1Y. Note that the toner at this time may be a one-component toner or a two-component toner, but is a two-component toner here.

The recording paper P is electrostatically attracted to the recording paper transport belt 21 in the same manner as the toner image passes through the transfer area (nip portion) between the electrophotographic photosensitive member 1Y and the recording paper transport belt 6. Then, the recording paper P is conveyed to a transfer area (nip portion), and is sequentially transferred to the outer peripheral surface of the recording paper P by an electric field formed by a transfer bias applied from the transfer roll 7Y.

Thereafter, the toner remaining on the electrophotographic photosensitive member 1Y is cleaned and cleaned by the electrophotographic photosensitive member cleaner 5Y.
Removed. Then, the electrophotographic photosensitive member 1Y is subjected to the next transfer cycle.

The above-described transfer cycle includes the units M, C,
The same applies to Bk.

The recording paper P, on which the toner image has been transferred by the transfer rolls 7Y, 7M, 7C, 7Bk, is further conveyed to the fixing device 9, where fixing is performed. Thus, a desired image is formed on the recording paper.

[0091]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these embodiments do not limit the present invention. In the description, “parts” means “parts by weight”.

-Measurement of Volume Resistivity- The volume resistivity in the present embodiment was measured using a circular electrode (HR probe of Hiresta IP manufactured by Mitsubishi Yuka: external system Φ16 mm of the first voltage application electrode A, shown in FIG. 1). Using the inner diameter Φ30 mm and the outer diameter Φ40 of the ring-shaped electrode B, a voltage of 500 V was applied, a current value after 30 seconds was obtained, and the value was calculated as described above.

Example 1 The material of the following Formulation Example 1 was kneaded with a Banbury mixer, extruded into a cylindrical shape with an extruder, and heated to 120 ° C. at a steam pressure of 1.5 kg / cm ² using a vulcanizing can. By heating and vulcanizing to a temperature, a conductive rubber belt is obtained. Further, this rubber belt is coated on the outside of the metal base material, the surface is polished, and the width is 320 mm and the circumference is 264.
A rubber belt (seamless belt) having a thickness of 0.5 mm and a thickness of 0.5 mm is obtained. On the surface of the obtained rubber belt, a water-emulsion paint (Emuralon JYL-345ES of Nippon Acheson Co., Ltd.) containing a urethane-modified fluorotetrafluoroethylene resin in which 8 parts of carbon black is dispersed as a urethane-modified fluororesin coating material is applied. Spray coating was performed at 20 μm, and the coating was heated at 120 ° C. for 35 minutes to form a coating layer having a thickness of 20 μm. Thus, the semiconductive belt of Example 1 was obtained.

-Formulation Example 1-EPDM: Nippon Synthetic Rubber EP33 ... 70 parts NBR: Nippon Synthetic Rubber N230SH ... 30 parts Granular acetylene black (Electric Chemical Industry) ... 10 parts FT carbon (Asahi Carbon Co., Ltd. 20 parts Vulcanizing agent 5 parts Vulcanization accelerator 2 parts Dispersing aid 0.5 part

The initial volume resistivity ρv1 of the obtained semiconductive belt of Example 1 was 10 ^9.5 Ωcm. The in-plane unevenness (difference between the maximum value and the minimum value) of the volume resistivity when a belt having a width of 320 mm and a circumferential length of 264 mm was divided into five in the width direction and divided into five in the circumferential direction and measured at 25 points was 0.1%. It was three digits (log Ωcm).

Example 2 The material of the following Formulation Example 2 was kneaded with a Banbury mixer, extruded into a cylindrical shape with an extruder, and heated to 120 ° C. at a steam pressure of 1.5 kg / cm ² using a vulcanizing can. By heating and vulcanizing to a temperature, a conductive rubber belt is obtained. Furthermore, this rubber belt is coated on the outside of the metal base material, the surface is polished, and the width is 320 mm and the circumference is 264.
A rubber belt (seamless belt) having a thickness of 0.5 mm and a thickness of 0.5 mm is obtained. On the surface of the obtained rubber belt, a water-emulsion paint (Emuralon JYL-345 ESD of Acheson Japan Co., Ltd.) containing a urethane-modified fluorotetrafluoroethylene resin in which 8 parts of carbon black is dispersed as a urethane-modified fluororesin coating material is applied. Spray coating was performed at 20 μm, and heating was performed at 120 ° C. for 35 minutes to form a surface coating layer having a thickness of 20 μm. Thus, a semiconductive belt of Example 2 was obtained.

-Formulation Example 2-EPDM: Nippon Synthetic Rubber EP33 ... 70 parts NBR: Nippon Synthetic Rubber N230SH ... 30 parts Granular acetylene black (Denki Kagaku Kogyo) ... 8 parts FT carbon (Asahi Carbon Co., Ltd. ) 20 parts Vulcanizing agent (organic peroxide) 1 part Vulcanization accelerator 2 parts Dispersing aid 0.5 part

The initial volume resistivity ρv1 of the obtained semiconductive belt of Example 2 was 10 ^10.1 Ωcm. The in-plane unevenness (difference between the maximum value and the minimum value) of the volume resistance when a belt having a width of 320 mm and a circumference of 264 mm was divided into five in the width direction and divided into five in the circumferential direction and measured at 25 points was 0.2. Digit (l
ogΩcm).

(Comparative Example 1) The material of the following Formulation Example 3 was kneaded with a Banbury mixer, extruded into a cylindrical shape with an extruder, and heated to 120 ° C at a steam pressure of 1.5 kg / cm ² using a vulcanizing can. By heating and vulcanizing to a temperature, a conductive rubber belt is obtained. Furthermore, this rubber belt is coated on the outside of the metal base material, the surface is polished, and the width is 320 mm and the circumference is 264.
A rubber belt (seamless belt) having a thickness of 0.5 mm and a thickness of 0.5 mm is obtained. On the surface of the obtained rubber belt, a water-emulsion paint (Emuralon JYL-345 ESD of Acheson Japan Co., Ltd.) containing a urethane-modified fluorotetrafluoroethylene resin in which 8 parts of carbon black is dispersed as a urethane-modified fluororesin coating material is applied. Spray coating was performed at 20 μm, and heating was performed at 120 ° C. for 35 minutes to form a surface coating layer having a thickness of 20 μm. Thus, a semiconductive belt of Comparative Example 1 was obtained.

-Formulation Example 3-CR: 100 parts Ketchen Black (Lion Aguso Co., Ltd.): 13 parts Vulcanizing agent (organic peroxide): 1 part Vulcanization accelerator: 2 Part Anti-aging agent 1.5 parts

The initial volume resistivity ρv1 of the obtained semiconductive belt was 10 ^9.4 Ωcm. In addition, width 320
mm, a belt having a circumference of 264 mm was divided into 5 parts in the width direction and five parts in the circumferential direction, and the in-plane unevenness (difference between the maximum value and the minimum value) of the volume resistance when measuring 25 points was 1.1 digits (logΩcm). )
Met.

(Comparative Example 2) The material of the following Formulation Example 4 was kneaded with a Banbury mixer, extruded into a cylindrical shape with an extruder, and heated to 120 ° C. at a steam pressure of 1.5 kg / cm ² using a vulcanizing can. By heating and vulcanizing to a temperature, a conductive rubber belt is obtained. Furthermore, this rubber belt is coated on the outside of the metal base material, the surface is polished, and the width is 320 mm and the circumference is 264.
A rubber belt (seamless belt) having a thickness of 0.5 mm and a thickness of 0.5 mm is obtained. On the surface of the obtained rubber belt, a water-emulsion paint (Emuralon JYL-345 ESD of Acheson Japan Co., Ltd.) containing a urethane-modified fluorotetrafluoroethylene resin in which 8 parts of carbon black is dispersed as a urethane-modified fluororesin coating material is applied. Spray coating was performed at 20 μm, and heating was performed at 120 ° C. for 35 minutes to form a surface coating layer having a thickness of 20 μm. Thus, a semiconductive belt of Comparative Example 2 was obtained.

-Formulation Example 4-EPDM: 100 parts Ketchen Black: Lion Aguso Co., Ltd .: 13 parts Vulcanizing agent: 2 parts Vulcanization accelerator: 2 parts Antioxidant: 1.5 parts

[0104] The resulting initial volume resistivity of the semiconductive belt of Comparative Example 2 Robui1 was 10 ^9.7 [Omega] cm. The in-plane unevenness (difference between the maximum value and the minimum value) of the volume resistance when a belt having a width of 320 mm and a circumferential length of 264 mm was divided into five in the width direction and five in the circumferential direction and measured at 25 points was 0.9. Digit (l
ogΩcm).

(Comparative Example 3) Using a twin-screw extruder, ETF
13 parts of Ketchen Black (Lion Aguso Co., Ltd.) are kneaded with 100 parts of E resin to obtain carbon dispersed ETFE resin pellets. Further, this resin pellet was extruded into a cylindrical shape using a single screw extruder to obtain a carbon-dispersed ETFE resin belt having a width of 320 mm, a circumference of 264 mm and a thickness of 150 μm. This was used as the semiconductive belt of Comparative Example 3.

[0106] The resulting initial volume resistivity of the semiconductive belt of Comparative Example 3 Robui1 was 10 ^8.4 [Omega] cm. The in-plane unevenness (difference between the maximum value and the minimum value) of the volume resistance when a belt having a width of 320 mm and a circumferential length of 264 mm is divided into five in the width direction and divided into five in the circumferential direction and measured at 25 points is 0.6 Digit (l
ogΩcm).

<Evaluation 1> The semiconductive belts obtained in Examples 1 to 2 and 1 to 3 were subjected to 1% tensile repetition strain of 3%.
000 (1K) times, 2000 (2K) times, 3000 (3
K) times and 10,000 (10K) times, the volume resistivity ρv2 was measured. FIG. 5 shows that the amount of tensile repetition strain of 3% was 1000 (1K) times, 2000 (2K) times,
It is a figure which shows the change of volume resistivity (rho) v2 at the time of giving 3000 (3K) times and 10,000 (10K) times. According to FIG. 5, the amount of change ΔR (ΔR = |
logρv1-logρv2 |) are 0.5 digits (logΩcm) and 0.4 digits (logΩcm), respectively, whereas Comparative Example 1 is one digit (logΩcm) and Comparative Example 2
Is 0.9 digits (log Ωcm), and Comparative Example 3 is 0.7 digits (l
og Ωcm) and the volume resistivity ρv changed significantly.

<Evaluation 2> The semiconductive belts obtained in Examples 1 to 2 and 1 to 3 were arranged as recording paper transport belts 6 in the image forming apparatus shown in FIG. The volume resistivity ρv3 at that time was measured. The semiconductive belts obtained in Examples 1 to 2 and 1 to 3 had a thickness of 0.8 mm, a width of 320 mm, and a circumference of 845. FIG. 6 shows Examples 1-2 and 1-2.
3 was placed in the image forming apparatus shown in FIG. 4, and a volume resistivity ρv when a running test was performed.
FIG. According to FIG. 6, the change amount ΔR (ΔR = | logρv1-log) of the volume resistivity of the first and second embodiments.
ρv3 |) is 0.4 digits (logΩcm),
0.3 digit (log Ωcm), while Comparative Example 1
Is 1.2 digits (logΩcm) and Comparative Example 2 is 0.9 digits (l
og Ωcm) and that of Comparative Example 3 was 0.8 (log Ωcm), indicating that the volume resistivity changed.

<Evaluation 3> The semiconductive belts obtained in Examples 1 to 2 and 1 to 3 were arranged as recording paper transport belts 21 in the image forming apparatus shown in FIG. The volume resistivity ρv4 at the time is measured, and the change amount of the volume resistivity ΔR (ΔR = | logρv1-logρ
v4 |) was determined. A metal roll having an outer diameter of 10.5 mm was used as the support rolls 27 and 28 in the image forming apparatus shown in FIG. FIG. 7 shows the change amount ΔR of the volume resistivity when the semiconductive belts obtained in Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to 10,000% (10K) times of the tensile repetitive strain of 3%. ΔR = | logρv1-logρv
2 |) and the semiconductive belts obtained in Examples 1 to 2 and 1 to 3 are arranged in the image forming apparatus shown in FIG. 3 and a change in volume resistivity ΔR ( ΔR = | l
ogρv1-logρv4 |). FIG.
The amount of change in volume resistivity ΔR (ΔR = | logρv1-l when a tensile repetitive strain of 3% is given 10K times,
ogρv2 |) is less than 0.5 digits in Examples 1 and 2, even in a 300 kcycle running test, the change in volume resistivity ΔR of the semiconductive belt (ΔR = | log
It can be seen that ρv1−logρv4 |) is as small as 0.4 digits or less. On the other hand, 3%
The amount of change ΔR in volume resistivity when given 0K times is 0.5
In the case of Comparative Examples 1, 2, and 3, which exceed the above, it can be seen that the resistance change is large even in the running test.

[0110]

As described above, according to the present invention, it is possible to obtain a semiconductive belt having a small resistance change amount due to an applied voltage or expansion and contraction at a supporting roll portion, and a stable high quality image. An image forming apparatus that can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode for measuring volume resistivity.

FIG. 2 shows an EPDM (SP value = 8.0) and an NBR (SP
FIG. 4 is a schematic diagram showing a dispersion state of carbon black in an incompatible binder resin having a value of 9.3).

FIG. 3 is a schematic configuration diagram illustrating an example of the image forming apparatus of the present invention.

FIG. 4 is a schematic configuration diagram illustrating another example of the image forming apparatus of the present invention.

FIG. 5 shows that the amount of 3% tensile strain is 1000
(1K) times, 2000 (2K) times, 3000 (3K)
Volume resistivity ρ given 10,000 times (10K) times
It is a figure showing change of v2.

FIG. 6 shows the volume resistivity ρv when the semiconductive belts obtained in Examples 1 to 2 and 1 to 3 are arranged in the image forming apparatus shown in FIG. 2 and a running test is performed. FIG.

FIG. 7 shows that the semiconductive belts obtained in Examples 1 and 2 and Comparative Examples 1 to 3 had a tensile repetition strain of 3% of 1000%.
Change in volume resistivity ΔR when given 0 (10K) times
FIG. 6 is a diagram illustrating the amount of change in volume resistivity when the semiconductive belts obtained in Examples 1 to 2 and 1 to 3 are arranged in the image forming apparatus illustrated in FIG. 3 and a running test is performed. is there.

[Explanation of symbols]

A first voltage applying electrode B second voltage applying electrode C cylindrical electrode part D ring-shaped electrode part T semiconductive belt Y, M, C, Bk unit 1Y, 1M, 1C, 1Bk Electrophotographic photoreceptor 2Y, 2M, 2C, 2Bk Corotron charger 3Y, 3M, 3C, 3Bk Exposure unit 4Y, Yellow developing unit 4M Magenta developing unit 4C Cyan developing unit 4Bk Black developing unit 5Y, 5M, 5C, 5Bk Electrophotographic photosensitive member cleaner 6 Recording paper transport belt (Transfer Conveying Belt) 7Y, 7M, 7C, 7Bk Transfer Roll 8 Recording Paper Conveying Roll 9 Fixing Device 10, 11.12, 13 Support Roll 14 Belt Cleaning Device 20 Electrophotographic Photoreceptor 21 Recording Paper Conveying Belt (Transfer Conveying) Belt) 22 transfer roll 23 recording paper tray 24 fixing device 25 developing device 26 pickup roll 27, 8 support rolls T toner image P recording paper

Claims (6)

[Claims] 1. An initial volume resistivity ρv1 (Ωcm),
A semiconductive belt characterized in that the relation with the volume resistivity ρv2 (Ωcm) after giving a tensile repetitive strain of 3% 10,000 (10K) times satisfies the following expression (1). Expression (1) | logρv1−logρv2 | ≦ 0.5 2. An initial volume resistivity of 10 ⁸ Ωcm to 1
The semiconductive belt according to claim 1, wherein the belt has a resistance of 0 ¹¹ Ωcm. 3. The semiconductive belt according to claim 1, comprising at least two kinds of incompatible materials. 4. The semiconductive belt according to claim 1, further comprising a surface coat layer, wherein said surface coat layer is made of a low surface energy material. 5. The material according to claim 4, wherein the low surface energy material is a material obtained by dispersing fluororesin particles.
5. The semiconductive belt according to claim 1. 6. An image forming apparatus comprising a transfer conveyance belt for conveying a transfer object in a transfer area for transferring a toner image to a transfer object, wherein the transfer conveyance belt is provided.
An image forming apparatus, wherein the image forming apparatus is the semiconductive belt according to any one of the above.