JP2002014548A - Intermediate transfer body image forming device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer body which is less changed in shape at a temperature supposed in the environment for using M/C, prevents the degradation in resistance by transfer voltage, improves the uniformity of the electric resistance, has lower dependence on electric fields, is less changed in the resistance by the environment and make it possible to obtain high image quality as well as an image forming device with which the high-quality transfer images may be obtained. SOLUTION: This intermediate transfer body is constituted by incorporating electron conductive fillers which develop electrical conductivity by electron conduction and have a pH of <=5.0 in a resin molding containing a thermoplastic resin having a coefficient of thermal expansion of <=70 ppm/ deg.C in a range of 10 to 50 deg.C and the image forming device having the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate transfer member used in an electrophotographic image forming apparatus such as a copying machine or a printer, and an image forming apparatus having the same.
An intermediate transfer member used in an image forming apparatus in which a toner image formed on a latent image carrier is temporarily transferred to an intermediate transfer member and then transferred to a transfer target such as paper to obtain a reproduced image, and The present invention relates to an image forming apparatus having the same.

[0002]

2. Description of the Related Art An image forming apparatus using an electrophotographic method is:
A uniform charge is formed on an image carrier made of a photoconductive photoreceptor made of an inorganic or organic material, and an electrostatic latent image is formed with a laser beam or the like that modulates an image signal. The latent image is developed into a visualized toner image. Then, the required reproduced image is obtained by electrostatically transferring the toner image via an intermediate transfer member or directly to a transfer material such as recording paper.

[0003] In particular, 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 Application Laid-Open No. 62-206567 and the like are known.

[0004] Materials used in an image forming apparatus employing the intermediate transfer member system include polycarbonate resin (JP-A-06-095521), PVDF (polyvinylidene fluoride) (JP-A-5-200904, and JP-A-6-200904). JP-A-228335), polyalkylene phthalate (JP-A-6-149081), a blend material of PC (polycarbonate) / PAT (polyalkylene terephthalate) (JP-A-6-149083), ETFE
(Ethylene tetrafluoroethylene copolymer) / PC, E
It has been proposed to use a semiconductive endless belt in which carbon black is added to a thermoplastic resin such as a blended material of TFE / PAT and PC / PAT (Japanese Patent Application Laid-Open No. 6-149079).

However, it is very difficult to control the resistance value of the resin material in the semiconductive region, and it is difficult to obtain a desired resistance value stably by adding ordinary conductive carbon black to ordinary resin material. Almost not. For this reason, it is necessary to measure and select the resistance values of all the semiconductive endless belts, thereby increasing the cost. "Polymer processing,
43, No. 4, 1977, Sumita ", etc., when carbon black is added into a polymer such as a resin material, the conductivity is small while the addition of carbon black is small. This is because carbon black forms a conductor circuit from a certain threshold value, and the conductivity is rapidly improved, so that a medium resistance value cannot be obtained.

In the case of the above-described carbon black-dispersed polycarbonate or carbon black-dispersed ethylene tetrafluoroethylene copolymer, after continuously transferring 1,000 or more sheets shorter than the width of the intermediate transfer member such as a postcard, When a half-tone (magenta 30%) image is transferred, a problem arises in that the paper running portion slips through. This white spot defect was particularly remarkable in a low-temperature and low-humidity environment of 10 ° C. and 15% RH. The paper running part slips off because the surface resistivity of the paper running part of the intermediate transfer body is lower than that of the peripheral part due to the peeling discharge between the intermediate and the paper at the time of peeling the paper at the secondary transfer part. This is because the transfer efficiency is lower than that of the peripheral site. The electric field dependence of the surface resistivity of the carbon black-dispersed polycarbonate and the carbon black-dispersed ethylene tetrafluoroethylene copolymer is 0.8 to 1.5 digits (log Ω /
□) level, and it is considered that the electric field concentration due to the transfer voltage caused the deterioration of the resin component in the vicinity of the highly conductive portion, and the surface resistivity decreased.

[0007] The large electric field dependence of surface resistivity is due to
As described above, it is difficult to uniformly disperse the carbon black in the resin component constituting the intermediate transfer member, so the carbon black is unevenly dispersed in the resin, and therefore, locally, the conductivity is large. It is considered that there is a site where the electric field concentrates.

In order to impart conductivity to the material constituting the intermediate transfer member, a method of imparting a conductive agent for imparting electronic conductivity, such as carbon black, to a composition material and a method of imparting a conductive agent for imparting ionic conductivity are provided. There is a way to do that. But,
When a conductive agent for imparting ionic conductivity is provided, the change in the electric resistance value in the plane of the intermediate transfer member is extremely small.
It is desirably five digits or less, and there is little problem that the surface resistance is locally reduced and the surface resistance is reduced due to the concentration of the electric field there. On the other hand, the electrical resistance changes greatly due to environmental changes in temperature and humidity.
8 ℃, 85% RH high temperature and high humidity environment (H / H environment) and 10
There is a problem that the difference in electric resistance between the low-temperature and low-humidity environment (L / L environment) of 15 ° C. and 15% RH is 1.5 to 4 digits (logΩ).

Further, in general, the conductive agent of the ionic conductive type has an electric resistance value at a low temperature and a low humidity, and it is necessary to increase the amount of the conductive agent of the ionic conductive type in order to obtain a predetermined resistance value. If the amount is increased, the ionic conductive agent oozes out of the surface of the intermediate transfer member and migrates (bleeds out) to the surface of the image carrier, which causes a new problem that image deterioration, contamination, and erosion of the photosensitive material are likely to occur. Occurs.

[0010]

As a countermeasure, Japanese Patent Laid-Open Publication No. Hei 8-110711 discloses a method of laminating a material in which an ion conductive type conductive agent is dispersed and a material in which an electron conductive type conductive agent is dispersed. A proposal has been made to use it. However, in both cases, the higher resistance layer governs the resistance of the belt, so that when two or more layers are used, the behavior of the material of the high resistance layer is exhibited. For example, when the layer of the material in which the conductive agent of the electron conduction type is dispersed has a higher resistance than the layer of the material in which the conductive agent of the ion conductive type is dispersed, variation in resistance is large, There are problems such as high dependency.

The electrical resistance of the intermediate transfer member is controlled within a predetermined range in order to obtain a high quality transfer image, and the in-plane variation of the intermediate transfer member (maximum and minimum resistance values). However, it is required that the electrical resistance value does not change significantly even when the use environment conditions change, and that high quality can be stably obtained.

For example, in practice, the in-plane variation of the electric resistance value of the intermediate transfer member is within one digit (logΩ / □), and the low-temperature and low-humidity environment (L / L environment) of 10 ° C. and 15% RH.
It is required that the change in electric resistance value in a high-temperature and high-humidity environment (H / H environment) of 28 ° C. and 85% RH be within 1.5 digits.

[0013] In the above-mentioned prior art, the belt is driven using two or more metal rolls, a roll formed by coating a resin layer on a metal surface, a rubber roll, or the like.
Conventional high-cost full-color copiers and printers intended for some corporate users are now being applied to a wider range of users, including small and medium offices and ordinary households. Full-color copiers and printers for such users require ever more compact, low-cost, and high-speed main units.

[0014] For this reason, it has become necessary to reduce the cost of the belt drive system by making it simple. Miniaturization of the body,
In order to simplify the belt drive system, it is difficult to obtain a stable belt drive speed when the belt circumference changes greatly and the belt tension changes. (Hereinafter referred to as “M / C use environment”), it is required that the belt circumference does not change within a certain range.

[0015] When the temperature of the environment in which the M / C is used changes, the circumference of the belt changes beyond a certain range or more, so that the belt tension deviates from the range in which the belt speed can be controlled stably. . For example, when the belt circumference becomes longer, the belt tension becomes weaker, the gripping force with the roll that drives the belt becomes weaker, and the belt speed fluctuates due to slipping, so that when multicolor toners are stacked, The problem of displacement occurs.

In the case of the above-described polycarbonate dispersed in carbon black and ethylene tetrafluoroethylene copolymer dispersed in carbon black, the thermal expansion coefficient is 80 ppm / ° C. for polycarbonate and 150 ppm / ° C. for ethylene tetrafluoroethylene copolymer. In the range of 10 ° C. to 50 ° C. assumed in the M / C use environment,
In an image forming apparatus employing an intermediate transfer method in which a plurality of toner images are superimposed on each other by changing the belt circumferential length, this causes color misregistration.

Heretofore, the present applicant has filed Japanese Patent Application No. 2000-287.
In the specification No. 04, the surface resistivity of the sheet traveling portion of the intermediate transfer member is lower than that of the peripheral portion due to a peeling discharge between the intermediate and the sheet when the sheet is peeled in the secondary transfer portion, and the transfer efficiency is reduced. As a measure for solving the problem of lowering than the peripheral portion, an intermediate transfer member containing oxidized carbon black has been proposed. However, the proposed intermediate transfer belt still has a problem in that the belt circumference changes in the range of 10 ° C. to 50 ° C. assumed in the above-described M / C use environment. .

An object of the present invention is to solve the above conventional problems and achieve the following objects. That is, the present invention has a small shape change at a temperature assumed in an M / C use environment, prevents a decrease in resistance due to a transfer voltage, improves the uniformity of electric resistance, has a small electric field dependency, and has a low electric field dependency. It is an object of the present invention to provide an intermediate transfer member and a charging member capable of obtaining high image quality with little change in resistance due to image formation, and an image forming apparatus capable of stably obtaining high quality transfer image quality.

[0019]

The above object is achieved by the following means. That is, the present invention provides: <1> a coefficient of thermal expansion in the range of 10 ° C. to 50 ° C. of 70 p
An intermediate transfer member characterized in that a resin composition containing a thermoplastic resin having a temperature of pm / ° C. or less contains an electron conductive filler having a pH of 5.0 or less that exhibits conductivity by electron conduction. <2> The intermediate transfer member according to <1>, wherein the electron conductive filler is carbon black having a pH of 5.0 or less. <3> The intermediate transfer member according to <2>, wherein carbon black having a pH of 5.0 or less is produced by a contact method. <4> The intermediate transfer member according to any one of <1> to <3>, wherein the thermoplastic resin has a glass transition temperature of 90 ° C or higher. <5> The intermediate transfer according to any one of claims 1 to 4, wherein the thermoplastic resin is at least one selected from polyetherimide, polyphenylene sulfide, polyether sulfone, and poly-ether ether ketone. Body. <6> The intermediate transfer member according to any one of <1> to <4>, wherein the thermoplastic resin is a polyetherimide. <7> The electric field dependency of the surface resistivity is 0.6 digits (log Ω).
/ <1> to <6>.
The intermediate transfer member according to any one of the above. <8> Any one of the above items <1> to <7>, wherein a difference between common logarithmic values of the surface resistivity ρs at 30 ° C. 85% RH and 10 ° C. 15% RH is 1.0 digit or less. Or an intermediate transfer member described in <9> An image forming apparatus including the intermediate transfer member according to any one of <1> to <8>.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The intermediate transfer member of the present invention has a temperature of 10 ° C.
A resin composition containing a thermoplastic resin having a thermal expansion coefficient of 70 ppm / ° C. or less in a range of 50 ° C. contains an electron conductive filler having a pH of 5.0 or less, which expresses conductivity by electron conduction.

In the intermediate transfer member of the present invention, the pH of the intermediate transfer member in the resin composition containing the non-crystalline polyester resin is 5.5.
The electron conductive filler of 0 or less is partially affected by excessive current flowing, is less susceptible to oxidation due to repeated voltage application, and further has the effect of an oxygen-containing functional group attached to its surface. The dispersion in the inside is high, the resistance variation can be reduced, the electric field dependence is also reduced, and the electric field concentration due to the transfer voltage becomes difficult. As a result, resistance reduction due to transfer voltage is prevented,
An intermediate transfer member that improves uniformity of electric resistance, has low electric field dependence, has little change in resistance due to the environment, and is capable of obtaining high image quality in which the occurrence of image quality defects such as whitening of a paper running portion is suppressed. Becomes Also, 10 ° C to 50 ° C
By using a thermoplastic resin having a coefficient of thermal expansion of 70 ppm / ° C. or less in the range of (1), there is little change in shape in the range of 10 ° C. to 50 ° C. assumed in an M / C use environment. In this case, the amount of change in the belt circumference is reduced, and the problem of occurrence of color shift is reduced. Prevention of this color shift is particularly effective for an image forming apparatus employing an intermediate transfer method in which a plurality of toner images are superimposed.

Here, the drop in resistance due to the transfer voltage and the occurrence of white spots due to the drop in resistance will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating a reduction in resistance of a secondary transfer portion of an intermediate transfer member. As shown in FIG. 1, a support roller 1 is interposed via a belt-shaped intermediate transfer body 101.
A transfer voltage is applied to the secondary transfer portion (nip portion) formed by the transfer roller 02 and the transfer roller 103 at the same time as the sheet (transfer object) 104 is passed, and secondary transfer is performed. Immediately after the secondary transfer, the surface (paper side) of the belt-shaped intermediate transfer body 101 is charged to the plus side, and the surface of the paper 104 (intermediate transfer body side) is charged to the minus side. Separation discharge occurs between the semiconductor device and the semiconductor device 104. Due to this discharge phenomenon, the surface of the intermediate transfer member 101 is altered, a new conductive path is formed, and the resistance is reduced. If the electric field dependency is large, the electric field is concentrated on the surface of the intermediate transfer member 101, and the surface of the intermediate transfer member 101 is easily deteriorated, so that the resistance is reduced.

FIG. 2 is a schematic diagram illustrating a situation in which white spots occur in halftone. As shown in FIG.
Paper running unit 2 in intermediate transfer body 200 after continuous copying of 00 sheets (for example, in a low temperature and low humidity environment of 10 ° C. and 15% RH)
01, the resistance is reduced as shown in FIG.
Middle (a)). When a halftone of 30% of magenta is copied in such a state, it is difficult to print on the paper traveling unit 201 having lower resistance than the non-paper traveling unit 202 ((b) in FIG. 2). As a result, white spots occur. In particular, the occurrence of this white spot is caused by the surface resistivity of the paper traveling unit 201 being 1.1 digits (logΩ /
□) It is easy to occur when the temperature is lower than the above.

The thermoplastic resin has a coefficient of thermal expansion in the range of 10 ° C. to 50 ° C. of 70 ppm / ° C. or less.
It is preferably at most 50 ppm / ° C. If this coefficient of thermal expansion exceeds 70, the temperature of 10 ° C. assumed in the M / C use environment
In the range from to 50 ° C., the amount of change in the belt circumferential length is large, and color shift and the like are likely to occur.

The thermoplastic resin has a glass transition temperature of 9
The temperature is preferably 0 ° C. or higher, more preferably 150 ° C. or higher, and even more preferably 200 ° C. or higher. When the glass transition temperature is 90 ° C. or higher, there is little change in the properties of the resin material in a temperature range up to 50 ° C. assumed in the use environment of M / C, and the resin material can be used stably in the use environment. .

The thermoplastic resin is not particularly limited as long as the coefficient of thermal expansion satisfies the above conditions. Examples thereof include polyimide, polyetherimide, polyphenylene sulfide, polyether sulfone, polyether ether ketone, polyamide, polycarbonate, and the like. Resin materials such as polyester, polyvinylidene fluoride (PVDF), and polyfluoroethylene-ethylene copolymer (ETFE), and resin materials using these as main raw materials are exemplified. These resin materials can be used by blending with an elastic material. Examples of the elastic material include polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, and a material obtained by blending two or more types of silicone rubber.

As the thermoplastic resin, polyetherimide (thermal expansion coefficient: 49 ppm / ° C., glass transition point: 216)
℃), polyphenylene sulfide (coefficient of thermal expansion 30p
pm / ° C, glass transition point 92 ° C), polyether sulfone (coefficient of thermal expansion 55 ppm / ° C, glass transition point 225)
C.) and polyetheretherketone (coefficient of thermal expansion 50 ppm / ° C., glass transition point 143 ° C.). Among them, polyetherimide is particularly preferred. Each resin material satisfies the above-mentioned coefficient of thermal expansion of 70 ppm / ° C. or less and a glass transition point of 90 ° C. or more, and the amount of deformation in a temperature range of 10 ° C. to 50 ° C. assumed in an M / C use environment. With little change in the properties of the resin material, and can be used stably in the use environment.

The electron conductive filler develops conductivity by electron conduction and has a pH of 5.0 or less, but preferably has a pH of 4.5 or less, and more preferably has a pH of 4.0. Specifically, as an electron conductive filler, pH 5.
0 or less (hereinafter sometimes referred to as “acidic carbon black”).

The acidic carbon black can be obtained by oxidizing the surface of the carbon black to impart an oxygen-containing functional group (for example, a carboxyl group, a quinone group, a lactone group, a hydroxyl group, etc.) to the surface. . This oxidation treatment is carried out in a high-temperature atmosphere by contacting and reacting with air in the air, by a method of reacting with nitrogen oxides or ozone at room temperature, and by a method of oxidizing air at a high temperature and then oxidizing ozone at a low temperature. And the like. Specifically, acidic carbon black can be produced by a contact method. The contact method includes a channel method, a gas black method, and the like, which can be appropriately selected and performed.

The acidic carbon black has a pH of 5.0 or less, but preferably has a pH of 4.5 or less, and more preferably has a pH of 4.0. This pH can be determined by preparing an aqueous suspension of carbon black and measuring with a glass electrode. Further, the pH can be adjusted by conditions such as a processing temperature and a processing time.

The acidic carbon black has a volatile content of 3.5% or more, preferably 5 to 25%, more preferably 10 to 15%. If this volatile content is less than 3.5%, it becomes difficult to obtain the effect of the oxygen-containing functional group attached to the surface, the adhesion between the resin composition and the acidic carbon black is deteriorated, and May decrease in dispersibility. On the other hand, if the volatile matter content is higher than 25%, when dispersed in the resin composition, it may decompose, or the resulting molded article may have a poor appearance, which is not preferable.

The volatile components in the acidic carbon black are as follows:
When carbon black is heated at 950 ° C. for 7 minutes,
It can be determined from the ratio of the organic volatile components (oxygen-containing functional groups such as carboxyl groups, quinone groups, lactone groups, and hydroxyl groups) that come out.

Specific examples of the acidic carbon black include:
Cabot's "REGAL 400R" (pH 4.
0, volatile content 3.5%), “Col” by Degussa, Germany
or Black FW200 "(pH 2.5, volatile matter 2
0%), "SPECIALBLACK 4" (pH 3,
Volatile 14%), "Printex U" (pH 4.
5, volatile matter 5%), “Printex 150T” (p
H4, volatile content 10%), "Printex 140T"
(PH 4.5, volatile content 5%). In addition,
The acidic carbon black may be used alone or in combination with other carbon blacks as long as it is used as an electron conductive filler that exhibits main conductivity.

The addition amount of the electron conductive filler is suitably 5 to 40% by weight, preferably 10 to 25% by weight, more preferably 15 to 20% by weight, based on the resin composition.

Preferred physical properties of the intermediate transfer member of the present invention are shown below. The physical properties can be controlled by appropriately selecting the types and amounts of the above-described materials.

In the intermediate transfer member of the present invention, the electric field dependency of the surface resistivity is preferably 0.6 digits (logΩ / □) or less, and more preferably 0.5 digits (logΩ / □) or less. . By using the electron conductive filler, the electric field dependency of the surface resistivity becomes 0.6 digits (log Ω / □) or less, and the electric field concentration due to the transfer voltage as described above is less likely to occur. It is possible to prevent the occurrence of image quality defects such as a decrease in the surface resistance of the sheet running section and the whitening of the sheet running section in a halftone image. The electric field dependence of the surface resistivity indicates the electric field dependence of the surface resistivity on the transfer surface.

In the intermediate transfer member of the present invention, the electric field dependence of the surface resistivity is determined by applying an applied voltage of 100 V (an electric field of 143 V / c).
m) and a common logarithmic value of the surface resistivity under the conditions of an applied voltage of 1000 V (electric field of 1429 V / cm).
The surface resistivity can be measured according to a measuring method described later.

The intermediate transfer member of the present invention has a temperature of 30 ° C. and 85% RH.
The difference between the common logarithm of the surface resistivity at 10 ° C. and 15% RH is preferably 1.0 digit (logΩ / □) or less, more preferably 0.6 digit (logΩ / □) or less. Yes, more preferably 0.5 digit (logΩ / □) or less. By using the electron conductive type of the electron conductive filler, the difference in the common logarithmic value of the surface resistivity due to the environment of 30 ° C. 85% RH and 10 ° C. 15% RH can be suppressed to 1.0 digit or less, It is possible to improve the environmental resistance generated when the ion conduction type is used. In addition,
The surface resistivity is a value under the condition of an applied voltage of 100 V,
It can be measured according to the measurement method described later.

The intermediate transfer member of the present invention has a surface resistivity of 1 ×
10 ¹⁰ Ω / □ to 1 × 10 ¹⁴ Ω / □, preferably 1 × 10
It is preferable that the resistance is ¹¹ Ω / □ to 1 × 10 ¹³ Ω / □.
If the surface resistivity is higher than 10 ¹⁴ Ω / □, peeling discharge is likely to occur at the post nip portion where the image transfer member and the intermediate transfer member of the primary transfer portion are peeled off. Missing image quality defects may occur. on the other hand,
If it is less than 10 ⁹ Ω / □, the electric field strength in the pre-nip portion becomes strong, and the gap discharge in the pre-nip portion is likely to occur, which may cause a problem that the graininess of the image quality deteriorates. Therefore, by setting the surface resistivity within the above range, it is possible to prevent the occurrence of white spots due to discharge that occurs when the surface resistivity is high and the deterioration of image quality that occurs when the surface resistivity is low. The surface resistivity indicates the surface resistivity on the transfer surface.

In the intermediate transfer member of the present invention, the surface resistivity can be measured according to JIS K6991 using a circular electrode (for example, HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.). Specifically, for example, it can be measured using the circular electrode shown in FIG. FIG.
3A is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode for measuring surface resistivity. The circular electrode shown in FIG. 3 includes a first voltage application electrode A and a plate-shaped insulator B. The first voltage applying electrode A has a columnar electrode portion C and a cylindrical ring-shaped electrode 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. Part D
And The intermediate transfer member T is sandwiched between the columnar electrode portion C and the ring-shaped electrode portion D of the first voltage applying electrode A and the plate-shaped insulator B, and the cylindrical electrode portion C and the ring of the first voltage applying electrode A are interposed. A current I (A) flowing when a voltage V (V) is applied between the electrode and the electrode D is measured, and the following equation (1) is obtained.
As a result, the surface resistivity ρs (Ω / □) of the intermediate transfer body T can be calculated. Here, in the following equation (1), d (m
m) indicates the outer diameter of the columnar electrode portion C. D (mm) indicates the inner diameter of the ring-shaped electrode portion D.

Equation (1) ρs = π × (D + d) / (D−d) × (V / I)

The intermediate transfer member of the present invention has a volume resistivity of 1 ×.
10 ⁸ Ωcm to 1 × 10 ¹⁴ Ωcm, preferably 1 × 10
Is suitably a ^{10 Ωcm~1} × ^{10 12 Ωcm.}
If the volume resistivity is less than 10 ⁸ ΩCm, an electrostatic force for holding 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 static electricity between the toners is reduced. Due to the electric repulsion and the force of the fringe electric field near the image edge, the toner may be scattered around the image (blurring), and a problem that an image with large noise is formed may occur. On the other hand, the volume resistivity is 10 ¹⁴ Ωcm
If it is higher, the charge retaining force is large, so that there is a case where a problem that a charge eliminating mechanism is required because the surface of the intermediate body is charged by the transfer electric field in the primary transfer. Therefore, by setting the volume resistivity within the above range, it is possible to prevent the toner from scattering or a problem requiring a charge eliminating mechanism.

In the intermediate transfer member of the present invention, the volume resistivity can be measured using a circular electrode (for example, HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.) according to JIS K6991. Specifically, for example, FIG.
Can be measured using a circular electrode shown in FIG. FIG.
FIGS. 3A and 3B are a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode for measuring volume resistivity. The circular electrode shown in FIG. 4 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 ′. Columnar electrode part C 'and ring-shaped electrode part D' in the first voltage applying electrode A '
The intermediate transfer member T 'is sandwiched between the first voltage applying electrode B' and the second voltage applying electrode B ', and the voltage V ( The current I (A) flowing when V) is applied is measured, and 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

The intermediate transfer member of the present invention may have either a belt shape or a drum shape, but the belt shape is preferable in terms of the degree of freedom of arrangement of other subsystems and ease of handling. The intermediate transfer member of the present invention, when in the form of a belt, comprises a single layer or a plurality of elastic layers, and has a thermal expansion coefficient of 70 ppm / ° C.
A thermoplastic resin comprising:
It contains an H5 or less electron conductive filler. On the other hand, in the case of a drum shape, a thermoplastic resin having a single layer or a plurality of elastic layers on a substrate and having a thermal expansion coefficient of 70 ppm / ° C. or less is used as a constituent material of at least one of the elastic layers. And the composition material contains an electron conductive filler having a pH of 5 or less. A configuration in which a surface coat layer is provided on the elastic layer may be adopted. Further, in the intermediate transfer member of the present invention, a composition other than using a thermoplastic resin having a thermal expansion coefficient of 70 ppm / ° C. or less as a composition material of at least one elastic layer and an electron conductive filler having a pH of 5 or less as a conductive agent, For example, a conventionally known configuration can be adopted for the layer configuration, the type of the base, and the like.

The intermediate transfer member of the present invention comprises a first transfer means for primarily transferring a toner image formed on an image carrier onto the intermediate transfer member, and a transfer member for transferring the toner image transferred on the intermediate transfer member to a transfer member. This is used for an image forming apparatus provided with a second transfer unit for performing secondary transfer to the image forming apparatus. Further, the intermediate transfer member of the present invention, in the case of a belt shape, in a transfer area for transferring a toner image to a transfer target,
It may be used as a transfer / conveying belt for conveying the transfer object. Also, a charger (a charging roll, a charging belt (film), a charging brush, a charging blade, etc.) used for a charging unit,
Each of the above-mentioned materials is applied to a charging member (charging member) such as a transfer device (transfer belt, transfer roller, transfer belt (film), transfer rubber blade, etc.) used for the transfer means, similarly to the intermediate transfer member of the present invention. Can be done. For example, in the case of a charging roll or a transfer roll, as a composition material of at least one layer constituting a layer (for example, a conductive elastic layer) provided on a conductive support, the thermal expansion coefficient is 70 ppm /
An electronic conductive filler having a pH of 5 or less is used as a thermoplastic resin and a conductive agent at a temperature of 5 ° C. or less. In the case of a charging belt (film) or a transfer belt (film), a thermoplastic resin having a thermal expansion coefficient of 70 ppm / ° C. or less is used as a composition material of at least one layer constituting the belt, and an electronic material having a pH of 5 or less is used as a conductive agent. Use a conductive filler. The configuration other than these, for example, the layer configuration, the type of the base, and the like can be a conventionally known configuration.

(Image Forming Apparatus) The image forming apparatus of the present invention includes the above-mentioned intermediate transfer member of the present invention. An image forming apparatus according to the present invention includes a first transfer unit that primarily transfers a toner image formed on an image carrier onto an intermediate transfer body, and a secondary transfer unit that transfers the toner image transferred onto the intermediate transfer body onto a transfer target body. An image forming apparatus of an intermediate transfer system including a second transfer unit for transferring, and using the intermediate transfer body of the present invention as the intermediate transfer body. Also,
An image forming apparatus of an intermediate transfer system (in which tertiary or higher transfer is performed) having a mechanism for transferring the toner image transferred onto the intermediate transfer body to another intermediate transfer body may be used. Further, an image forming apparatus provided with the intermediate transfer body of the present invention as a transfer conveyance belt for conveying a transfer target body to a transfer area where a toner image is transferred to a transfer target body may be used. By providing the intermediate transfer member of the present invention, a high-quality transfer image can be obtained stably for a long period of time.

The image forming apparatus of the present invention is not particularly limited as long as it is an intermediate transfer type image forming apparatus. For example, a normal mono-color image containing only a single color toner in a developing device Forming apparatus, a color image forming apparatus that repeats primary transfer of a toner image carried on an image carrier to an intermediate transfer body sequentially, and a plurality of image carriers having developing units for each color are serially arranged on the intermediate transfer body. And a tandem type color image forming apparatus arranged. Specifically, the image carrier, charging means for uniformly charging the image carrier surface, exposure means for exposing the image carrier surface to form an electrostatic latent image, and developing the latent image formed on the image carrier surface Developing means for developing a toner image by using an agent, a fixing means for fixing a toner image on a transfer-receiving material, a cleaning means for removing toner and dust adhered to an image carrier, and a toner remaining on the surface of the image carrier. It can be arbitrarily provided by a known method, if necessary, such as a static eliminator for removing the electrostatic latent image.

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

The charging means is not particularly limited. For example, conductive or semiconductive rollers, brushes, films,
Known chargers such as a contact-type charger using a rubber blade and the like, a scorotron charger and a corotron charger using corona discharge, and the like can 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 exposure means is not particularly limited. For example, a semiconductor laser beam, an LE
A light source such as D light and liquid crystal shutter light, or an optical system device capable of exposing these light sources to a desired image through a polygon mirror is exemplified.

The developing means can be appropriately selected according to the purpose. For example, there is 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 roller to develop. And a developing device.

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

Examples of the second transfer means include a contact-type transfer charger such as a transfer roller exemplified as the first transfer means, a scorotron transfer charger, and a corotron transfer charger. 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 roller 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 roller is pressed at the position of the roller for guiding the intermediate transfer member, the operation of transferring the toner image from the intermediate transfer member to the transfer target member can be performed in a good state. become.

Examples of the light neutralizing means include a tungsten lamp and an LED. Examples of the light quality used in the light neutralizing process include white light from a tungsten lamp and the like, red light such as LED light and the like. . The intensity of the irradiation light in the photo neutralization process is usually set so as to be several times to 30 times the amount of light showing the half-life exposure sensitivity of the electrophotographic photosensitive member.

The fixing means is not particularly limited, and includes a fixing device known per se, such as a heat roller fixing device and an oven fixing device.

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

Hereinafter, as an example of the image forming apparatus of the present invention, a color image forming apparatus in which primary transfer is repeated will be described. FIG. 5 is a schematic configuration diagram illustrating an example of the image forming apparatus of the present invention. The image forming apparatus shown in FIG. 5 includes a photosensitive drum 1 as an image carrier, a transfer belt 2 as an intermediate transfer member, a bias roller 3 as a transfer electrode, a tray 4 for supplying a sheet as a transfer target, and B ( A developing device 5 using black (toner) toner, a developing device 6 using Y (yellow) toner, a developing device 7 using M (magenta) toner, a developing device 8 using C (cyan) toner, a belt cleaner 9, a peeling claw 13, a belt roller 21, 23 and 24, backup roller 2
2, conductive roller 25, electrode roller 26, cleaning blade 31, sheet bundle 41, pickup roller 42,
And a feed roller 43.

In the image forming apparatus shown in FIG. 5, the photosensitive drum 1 rotates in the direction of arrow A, and its surface is uniformly charged by a charging device (not shown). An electrostatic latent image of the first color (for example, B) is formed on the charged photosensitive drum 1 by image writing means such as a laser writing device. This electrostatic latent image is developed with toner by the 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 is disposed by the rotation of the photosensitive drum 1, and the toner image T is made static by applying an electric field of opposite polarity to the toner image T from the conductive roller 25. While being electrically attracted to the transfer belt 2, primary transfer is performed by rotation of the transfer belt 2 in the direction of arrow B.

Hereinafter, similarly, the second color toner image, the third color toner image
A color toner image and a fourth color toner image are sequentially formed and superimposed on the transfer belt 2 to form a multiple toner image.

The multi-toner image transferred to the transfer belt 2 reaches the secondary transfer section where the bias roller 3 is installed by the rotation of the transfer belt 2. The secondary transfer section includes a bias roller 3 provided on the surface of the transfer belt 2 on which the toner image is carried, a backup roller 22 disposed from the back side of the transfer belt 2 so as to face the bias roller, and the backup roller 22. The electrode roller 26 is configured to rotate while being pressed against.

Sheets 41 are taken out one by one from a sheet bundle stored in a sheet tray 4 by a pickup roller 42, and are fed by a feed roller 43 at a predetermined timing between the transfer belt 2 of the secondary transfer section and the bias roller 3. Sent by The toner image carried on the transfer belt 2 is transferred to the fed sheet 41 by the pressure conveyance by the bias roller 3 and the backup roller 22 and the rotation of the transfer belt 2.

The sheet 41 onto which the toner image has been transferred is separated from the transfer belt 2 by operating the separation claw 13 at the retracted position until the primary transfer of the final toner image is completed, and is conveyed to a fixing device (not shown) to be pressed. / The toner image is fixed by the heat treatment to be a permanent image. The transfer belt 2 on which the transfer of the multi-toner image onto the paper 41 has been completed is subjected to removal of residual toner by a belt cleaner 9 provided downstream of the secondary transfer unit to prepare for the next transfer. Also, the bias roller 3
Is a cleaning blade 31 made of polyurethane or the like.
Are attached so that they are always in contact with each other, and foreign matters such as toner particles and paper dust adhered by 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 transfer belt 2 and the rotation of the photosensitive drum 1 are synchronized so that the toner images of the respective colors exactly coincide with each other in the primary transfer portion, and the toner images of the respective colors are shifted. Not to be. 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 transfer belt 2. The toner image is transferred to the paper 41 by electrostatic repulsion. As described above, an image can be formed.

[0065]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these embodiments do not limit the present invention.

Example 1 "Ultem 10" manufactured by Nippon DI Plastics Co., Ltd. was used as a polyetherimide resin.
00 "and 100 parts by weight of carbon black
"Prin" manufactured by Degussa of Germany with a volatile content of 5% and 4.5
tex140T "was added thereto, and carbon black was kneaded with the polyetherimide resin to obtain polyetherimide resin pellets obtained by adding 14 parts by weight of carbon black. Further, the resin pellets were extruded into a tube shape using a single screw extruder to obtain a thickness of 150 mm.
An endless belt having an outer diameter of 168 mm and a width of 350 mm was obtained. The surface resistivity of this belt was 10 ^12.0 Ω / □, and the volume resistivity was 10 ^10.5 Ωcm.

Example 2 As a polyetherimide resin, "Ultem 10" manufactured by Nippon DI Plastics Co., Ltd.
00 "and 100 parts by weight of carbon black
"Prin" manufactured by Degussa of Germany with a volatile content of 5% and 4.5
tex150 "was added by 16 parts by weight, carbon black was kneaded with the polyetherimide resin, and polyetherimide resin pellets obtained by adding 16 parts by weight of carbon black were obtained. Further, this resin pellet was extruded into a tube shape using a single screw extruder, and the thickness was 150 μm.
m, an endless belt having a width of 350 mm and an outer diameter of 168 mm was obtained. The surface resistivity of this belt was 10 ^11.8 Ω / □, and the volume resistivity was 10 ^10.2 Ωcm.

Example 3 As a polyether ether ketone resin, "381G" 10 manufactured by VICTREX CO., LTD.
0 parts by weight, volatile matter 1 at pH 4 as carbon black
16% by weight of 0% "Printex 150T" manufactured by Cabot Corp. of the United States was added, and carbon black was kneaded with a polyether-etherketone resin using a twin-screw extruder.
Polyetheretherketone resin pellets obtained by adding 16 parts by weight of carbon black were obtained. Further, this resin pellet is extruded into a tube shape using a single screw extruder, and has an outer diameter 168 of 150 μm thickness and 350 mm width.
mm endless belt was obtained. The surface resistivity of this belt is 1
0 ^11.9 Ω / □ and volume resistivity was 10 ^10.0 Ωcm.

Example 4 A thermoplastic polyimide resin was used.
100 parts by weight of "Aurum 450" manufactured by Mitsui Chemicals, Inc.
And 3.5% volatiles at pH 4 as carbon black
Added 16 parts by weight of "Regal400" manufactured by Cabot, USA
In addition, using a twin screw extruder, thermoplastic polyimide resin
Knead carbon black into the material
16 parts by weight of thermoplastic polyimide resin pellet
I got it. Furthermore, this resin pellet is used with a single screw extruder.
And extruded into a tube shape, 150μm thick
To obtain an endless belt with a width of 350 mm and an outer diameter of 168 mm.
Was. The surface resistivity of this belt is 10 ^11.8Ω / □, volume resistance
Resistance rate is 10^10.1Ωcm.

(Comparative Example 1) As a polyether-etherketone resin, "381G" 10 manufactured by VICTREX CO., LTD.
0 parts by weight, "Volcan XC72" manufactured by Cabot, USA, having a pH of 8.5 and a volatile content of 1.5% as carbon black.
X "was added to 14 parts by weight, and carbon black was kneaded with a polyether ether ketone resin using a twin-screw extruder to obtain a polyether ether ketone resin pellet obtained by adding 14 parts by weight of carbon black. Further, this resin pellet was extruded into a tube shape using a single screw extruder to obtain an endless belt having a thickness of 150 μm, a width of 350 mm and an outer diameter of 168 mm. The surface resistivity of this belt was 10 ^11.9 Ω / □, and the volume resistivity was 10 ^9.6 Ωcm.

(Comparative Example 2) "381G" 10 manufactured by VICTREX Co., Ltd. as a polyether-etherketone resin
To 0 part by weight, 12 parts by weight of "Ketchen Black EC", a neutral carbon black having a pH of 9.0 and a volatile content of 1.5% manufactured by Lion Agusso Co., as a carbon black, was added,
Using a twin screw extruder, carbon black is kneaded with a polyether ether ketone resin to form a carbon black 12
Polyether ether ketone resin pellets were obtained by adding parts by weight. Further, the resin pellet was extruded into a tube shape using a single screw extruder, and the thickness was 150 μm.
m, an endless belt having a width of 350 mm and an outer diameter of 168 mm was obtained. The surface resistivity of the belt was 10 ^12.1 Ω / □, and the volume resistivity was ^108.8 Ωcm.

Comparative Example 3 "6876" 100 manufactured by Eastman Chemical Co., Ltd. was used as a non-crystalline polyester resin.
12 parts by weight of granular acetylene black manufactured by Denki Kagaku Kogyo Co., Ltd. having a pH of 5.7 and a volatile content of 0.9% as a carbon black were added to parts by weight, and the mixture was converted into an amorphous polyester resin using a twin-screw extruder. Carbon black was kneaded, and amorphous polyester resin pellets obtained by adding 12 parts by weight of carbon black were obtained. Furthermore, this resin pellet is extruded into a tube shape using a single screw extruder,
An endless belt having a thickness of 150 μm and an outer diameter of 168 mm and a width of 350 mm was obtained. The surface resistivity of this belt is 10 ^11.9 Ω
/ □, volume resistivity was 10 ^10.2 Ωcm.

(Comparative Example 4) As a polycarbonate-carbonate resin, “LEXAN 1” manufactured by Nippon GE Plastics Co., Ltd.
No. 31 "100 parts by weight" was kneaded with Sanyo Kasei Kogyo Co., Ltd. "Pelestat 6321" which is a block type polymer having polyether as a main segment as an ion conductive polymer using a twin screw extruder to obtain pellets. . Next, at a heating temperature of 220 ° C., the pellet was molded into a tube shape using a single-screw extruder to a thickness of 0.15 mm.
Thus, an endless belt having a width of 350 mm and an outer diameter of 168 mm was obtained. The surface resistivity of this belt is 10 ^12.3 logΩ / □,
The volume resistivity was 10 ^12.5 logΩcm.

(Evaluation 1) In-plane variations in surface resistivity, volume resistivity, and surface resistivity of the endless belts obtained in Examples 1 to 4 and Comparative Examples 1 to 4 (difference between the maximum value and the minimum value). The environmental fluctuation width of the surface resistivity and the electric field dependence of the surface resistivity were examined. Further, the endless belt is mounted on the image forming apparatus shown in FIG. 5 as the transfer belt 2, and after continuously copying 1,000 postcards (sheets), the amount of decrease in the surface resistivity of the sheet traveling portion and the halftone of 30% of magenta are reduced. The occurrence of white spots and the occurrence of color misregistration at the time of copying were examined. Table 1 shows the results. In addition, each measurement was performed as shown below.

-Surface Resistivity- The surface resistivity in this example was measured using a circular electrode shown in FIG. 3 (HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd .; Using the inner diameter Φ30 mm and the outer diameter Φ40 mm of the ring-shaped electrode part D, the voltage 1
00V was applied, and the current value after 10 seconds was obtained and calculated as described above.

-Measurement of Volume Resistivity- The volume resistivity in the present embodiment was measured using a circular electrode shown in FIG. 4 (HR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd .: external system of cylindrical electrode portion C). Φ16 mm, inner diameter Φ30 mm of ring-shaped electrode part D, outer diameter Φ40 mm) and voltage 1
A current value of 30 seconds after application of 00 V was obtained, and the current value was calculated as described above.

-In-plane variation of surface resistivity-In-plane variation (ΔR) of surface resistivity in the present embodiment is:
The endless belt was divided into eight parts in the length direction and three parts in the width direction. The surface resistivity was measured at 24 points on the belt surface, the logarithmic value of the surface resistivity was obtained, and the difference between the maximum value and the minimum value was calculated. .

-Environmental Fluctuation Range of Surface Resistivity-The environmental fluctuation width in this embodiment is a high-temperature high-humidity (H / H) environment (30 ° C./85% RH) and a low-temperature low humidity (L / L) (10 ° C.)
/ 15% RH) was calculated as the difference between the logarithmic value of the surface resistivity and the environment.

-Electric Field Dependence of Surface Resistivity-The electric field dependence of the surface resistivity in the present embodiment is obtained by applying an applied voltage of 1
00V (electric field 143V / cm) and applied voltage 1000V
(Electric field 1429 V / cm) as the difference in logarithmic value of the surface resistivity under the condition of (electric field 1429 V / cm).

The amount of decrease in surface resistivity after continuous copying of 1000 sheets is determined by the initial surface resistivity and the surface resistance after continuous copying of 1000 sheets in this embodiment. It was calculated as the difference between the logarithm and the ratio.

-Occurrence of white spots after continuous copying of 1000 sheets-The occurrence of white spots in this embodiment is visually determined.
A level having no problem in image quality was evaluated as ○, and a level having a problem in image quality was evaluated as x.

—Color Shift Occurrence Status After Continuous Copying of 1000 Sheets— The color misregistration occurrence status in this embodiment is visually determined.
A level having no problem in image quality was evaluated as ○, and a level having a problem in image quality was evaluated as x.

[0083]

[Table 1]

From Table 1, it can be seen that Comparative Examples 1 to 3 use electron conductive neutral carbon, have large surface resistivity variations (ΔR) in the belt surface, and It can be seen that there is a large problem that there is a large amount of decrease in the surface resistivity of the paper running portion after continuous copying of 1000 postcards, indicating a situation where white spots occur when halftone is copied.

Further, the belt material of Comparative Example 4 in which the ion conductive polymer is dispersed has a small variation in surface resistivity in the belt surface (ΔR), and there is no problem that the surface resistivity of the paper running portion is reduced. Humid (H / H) environment and low temperature and low humidity (L
/ L) It can be seen that there is a problem that the fluctuation of the surface resistivity in the environment is as large as 1.8 digits. In Comparative Examples 3 and 4, a resin material having a high coefficient of thermal expansion was used.
It can be seen that color misregistration occurred after copying 0 sheets.

[0086]

As described above, according to the present invention, the shape change is small under the temperature assumed in the M / C use environment, the resistance is prevented from lowering due to the transfer voltage, and the uniformity of the electric resistance is improved.
Little dependence on electric field, little change in resistance due to environment,
It is possible to provide an intermediate transfer body and a charging member capable of obtaining high image quality, and an image forming apparatus capable of stably obtaining high quality transfer image quality.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a reduction in resistance of a secondary transfer portion of an intermediate transfer member.

FIG. 2 is a schematic diagram illustrating a situation in which white spots occur in halftone.

FIG. 3 is a schematic plan view (a) and a schematic cross-sectional view (b) showing an example of a circular electrode for measuring surface resistivity.

FIG. 4 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. 5 is a schematic configuration diagram illustrating an example of the image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Intermediate transfer body 102 Support roller 103 Transfer roller 104 Paper 200 Intermediate transfer body 201 Paper running part 202 Non-paper running part A First voltage application electrode B Second voltage application electrode C Column-shaped electrode part D Ring-shaped electrode part A ' One voltage application electrode B 'Plate-shaped insulator C' Column-shaped electrode part D 'Ring-shaped electrode part T, T' Intermediate transfer member 1 Photosensitive drum (image carrier) 2 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 Belt cleaner 13 Peeling claw 21, 23, 24 Belt roller 22 Backup roller 25 Conductive roller 26 Electrode roller 31 Cleaning blade 41 Paper (transfer object) ), Sheet bundle 42 pickup roller 43 feed roller T toner

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 81/06 C08L 81/06 101/00 101/00 F term (reference) 2H032 AA05 BA09 BA23 4J002 AA011 AC072 AC092 AC112 AC122 BB152 BB182 BD141 CF001 CG001 CH001 CH091 CK022 CL001 CM041 CM051 CN011 CN031 CP032 DA036 FD116 GQ00

Claims (9)

[Claims] 1. A resin composition containing a thermoplastic resin having a coefficient of thermal expansion of not more than 70 ppm / ° C. in a range of 10 ° C. to 50 ° C. has a pH of 5.0 which exhibits conductivity by electronic conduction.
An intermediate transfer member comprising the following electron conductive filler: 2. The intermediate transfer member according to claim 1, wherein the electron conductive filler is carbon black having a pH of 5.0 or less. 3. The intermediate transfer member according to claim 2, wherein carbon black having a pH of 5.0 or less is produced by a contact method. 4. The thermoplastic resin has a glass transition temperature of 90.
The intermediate transfer member according to any one of claims 1 to 3, wherein the intermediate transfer member is at least 0C. 5. The thermoplastic resin is a polyetherimide,
Polyphenylene sulfide, polyether sulfone,
5. The intermediate transfer member according to claim 1, wherein the intermediate transfer member is at least one member selected from the group consisting of polyether ether ketone and polyether ether ketone. 6. The intermediate transfer member according to claim 1, wherein the thermoplastic resin is a polyetherimide. 7. The electric field dependency of surface resistivity is within 0.6 digits (logΩ / □).
7. The intermediate transfer member according to any one of claims 1 to 6. 8. The method according to claim 1, wherein a difference between a common logarithmic value of the surface resistivity ρs at 30 ° C. 85% RH and a temperature at 10 ° C. 15% RH is 1.0 digit or less. 3. The intermediate transfer member according to item 1. 9. An image forming apparatus comprising the intermediate transfer member according to claim 1.