JP2001109231A - Conductive member and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive member which is nearly constant in electric resistance regardless of the varying magnitude of an impressed voltage, i.e., is nearly linear in the relation between the impressed voltage and current and is small in the dependence of the electric resistance on the environment. SOLUTION: The conductive member which is the conductive elastic member having a structure obtained by coating a conductive elastic layer with a conductive coating layer, in which the conductive elastic layer consists of polar rubber containing at least an ion conductive member and is ρ2<ρ1 when the specific volume resistivity of the conductive elastic layer is defined as ρ1 and the specific volume resistivity of the conductive coating layer as ρ2 and the image forming device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive member suitably used in an electrophotographic apparatus such as a copying machine, a facsimile, a printer, or an electrostatic recording apparatus, and an image forming apparatus equipped with the conductive member.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine, a facsimile, and a printer, charging,
To perform development, transfer, intermediate transfer, toner layer formation, toner conveyance, cleaning or recording paper conveyance, a belt,
Various members in the form of rollers, drums or blades are used. These members are usually required to be conductive, and are generally made of rubber or resin to which a conductive material such as carbon or metal oxide is added. However, the conductive mechanism of a conductive member to which a conductive material such as carbon or a metal oxide is added is based on conduction by electrons carrying electric charges,
That is, since the electric resistance is due to electronic conduction, the electric resistance of the conductive member changes according to the applied voltage applied to the conductive member. That is, the electrical resistance of the conductive member whose electronic conduction mechanism is electronically conductive has voltage dependency.
As shown in FIG. 1, the conductive member of the electronic conductive system has a small current up to a certain applied voltage, but the current rapidly increases when the applied voltage exceeds that value. Therefore, when trying to control the conductive member to a constant current, the current control becomes complicated. On the other hand, as a conductive member having a conductive mechanism other than electronic conductivity, an ionic conductive type conductive member to which an ionic conductive material is added has been proposed. The electrical resistance of an ion conductive type conductive member is substantially constant regardless of the applied voltage, and as shown in FIG. 2, the relationship between the applied voltage and the current becomes almost linear. And humidity). Furthermore, in the case of an ionic conductive type conductive member, the electric resistance does not decrease as much as that of an electronic conductive type conductive member, so that there is a problem that a sufficient and sufficient current cannot be obtained as a conductive member.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the electric resistance is almost constant regardless of the magnitude of the applied voltage, that is, the relationship between the applied voltage and the current is almost linear. Further, it is an object of the present invention to provide a conductive member having low environmental resistance of electric resistance and an image forming apparatus equipped with the conductive member.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have formed a conductive member by laminating a conductive coating layer on an ion conductive conductive elastic layer. By adopting a structure, and making the volume resistivity of the conductive coating layer smaller than the volume resistivity of the conductive elastic layer, the electrical resistance is almost constant regardless of the magnitude of the applied voltage.
That is, the relationship between the applied voltage and the current is almost linear,
In addition, it has been found that a conductive member having a small environmental resistance of electric resistance can be obtained. The present invention has been completed based on such findings. That is, the present invention provides a conductive member having a structure in which a conductive coating layer is laminated on a conductive elastic layer, wherein the conductive elastic layer is made of a polar rubber containing at least an ionic conductive material. Is the volume resistivity of ρ1, and the volume resistivity of the conductive coating layer is ρ2.
It is intended to provide a conductive member characterized by satisfying ρ2 <ρ1, and an image forming apparatus provided with the conductive member.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the conductive member of the present invention has a structure in which a conductive coating layer is laminated on a conductive elastic layer. The conductive member of the present invention can be in various forms such as a roller shape, a blade shape, a block shape, a belt shape, and the like. However, when used in an image forming apparatus, it can be used as a roller shape. It is suitable.
When the conductive member is formed in a roller shape, for example, FIG.
As shown in the figure, a conductive elastic layer 2
And a structure in which the conductive coating layer 3 is sequentially laminated. Here, as the conductive support, any one can be used as long as it has good conductivity, but usually, a metal core or a metal solid body is hollowed out. A metal shaft such as a metal cylinder is used. As the metal forming the shaft, a steel material such as sulfur free-cutting steel plated with zinc or the like, or a material made of aluminum, stainless steel, phosphor bronze, or the like can be used. The conductive elastic layer is made of a polar rubber containing an ionic conductive material, and is formed of a rubber composition obtained by adding an ionic conductive material to a polar rubber material. Examples of the polar rubber include nitrile rubber, urethane rubber, acrylic rubber, chloroprene rubber, epichlorohydrin rubber, and the like, and these may be used alone or in combination of two or more. Among these, one or a mixture of two or more selected from nitrile rubber, urethane rubber and epichlorohydrin rubber is particularly preferred. These polar rubbers can be synthesized by a known method. For example, in the case of urethane rubber, a polyol component such as polyether polyol, polyester polyol, polyolefin polyol, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), It can be obtained by curing a urethane rubber material comprising an isocyanate component such as crude diphenylmethane diisocyanate (crude MDI) using a catalyst such as dibutyltin dilaurate.

The ionic conductive materials added to these polar rubbers include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium, lauryltrimethylammonium, octadecyltrimethylammonium such as hexadecyltrimethylammonium and stearyltrimethylammonium, and benzyltrimethyl. Ammonium perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate such as ammonium and modified aliphatic dimethylethylammonium Organic ion conductive materials such as acid salts; perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides of alkali metals or alkaline earth metals such as lithium, sodium, calcium, and magnesium Periodate, trifluoromethyl sulfate, and inorganic ion conductive material such as sulfonate. Among these, ammonium perchlorate is preferred from the viewpoint that an increase in resistance during energization of the conductive elastic layer can be suppressed. The addition amount of the ionic conductive material is appropriately selected according to the type of the polar rubber, but is preferably 0.01 to 5 parts by weight, particularly preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the polar rubber material. . By adjusting the addition amount of the ionic conductive material, the volume resistivity ρ1 of the conductive elastic layer is preferably 10 ⁷ to 10 ¹⁰ Ω · cm, particularly preferably 10 ⁷ to 1 Ω · cm.
It can be adjusted to ⁰⁹ Ω · cm. In addition to the ionic conductive material, other rubber additives such as a filler, a crosslinking agent, and a foaming agent can be appropriately added to the polar rubber material forming the conductive elastic layer, if necessary.

In the present invention, the conductive coating layer laminated on the conductive elastic layer has a volume resistivity ρ2 smaller than the volume resistivity ρ1 of the conductive elastic layer. The conductive coating layer is made of a resin or rubber containing an electronic conductive material, and can be formed of a resin composition or a rubber composition obtained by adding a conductive material to a resin material or a rubber material. Resins include polyvinyl acetal resin, urethane resin, polyester resin, polyamide resin, epoxy resin, polybutadiene resin, cellulose resin, alkyd resin, melamine resin, phenol resin, fluororesin, acrylic resin, urethane modified acrylic resin, alkyl silicone resin, Acrylic urethane resin, silicone resin, amino resin, urea resin, vinylidene chloride resin, chlorinated polyethylene resin, ethylene vinyl acetate resin, ethylene ethyl acrylate resin, silicone-modified urethane resin, alkyd-modified silicone resin, epoxy-modified silicone resin, acrylic urethane silicone Resins and the like may be used, and these may be used alone or in combination of two or more. Among these, one or a mixture of two or more selected from urethane resins, polyester resins and acrylic resins is particularly preferred.

The rubber includes natural rubber, nitrile rubber, ethylene propylene rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, silicone rubber, urethane rubber, acrylic rubber, chloroprene rubber,
Epichlorohydrin rubber may be used, and these may be used alone or in combination of two or more. Among these, one or a mixture of two or more selected from nitrile rubber, urethane rubber and epichlorohydrin rubber is particularly preferred. As the conductive material added to the resin or rubber, it is preferable to use an electronic conductive material from the viewpoint that the volume resistivity of the conductive coating layer can be reduced. Examples of the electronic conductive material include conductive carbon black such as Ketjen black and acetylene black; SA
F, ISAF, HAF, FEF, GPF, SRF, F
Carbon black for rubbers such as T and MT; carbon oxide black, pyrolytic carbon black, graphite; conductive metal oxides such as tin oxide, titanium oxide, zinc oxide; barium sulfate, boric acid coated with conductive metal oxide Metal salts such as aluminum; metals such as nickel and copper; carbon whiskers, graphite whiskers, titanium carbide whiskers, conductive potassium titanate whiskers, conductive barium titanate whiskers, conductive titanium oxide whiskers, conductive zinc oxide whiskers, etc. Conductive whiskers are exemplified. Among these, conductive whiskers can be used because a small amount of the conductive whisker can reduce the electric resistance of the conductive coating layer and improve the durability of the conductive coating layer during energization. Is preferred. The addition amount of the electronic conductive material is appropriately selected according to the type of resin or rubber, but is preferably 1 to 200 parts by weight, particularly preferably 10 to 100 parts by weight, per 100 parts by weight of the resin material or rubber material. By adjusting the addition amount of the electronic conductive material, the volume resistivity ρ2 of the conductive coating layer is preferably set to 10 ¹ to 10 ⁸ Ω ·
cm, particularly preferably 10 ² to 10 ⁷ Ω · cm.

The thickness of the conductive coating layer is preferably from 3 to 300 μm, particularly preferably from 10 to 200 μm. If the layer thickness is too small, the sneak current decreases, and the effect of lowering the electric resistance may not be exhibited. Also,
If this layer thickness is too large, the hardness of the conductive member will increase. As a method of forming the conductive coating layer on the outer periphery of the conductive elastic layer, there are a method of coating as a coating film, a method of covering an extruded seamless tube, and the like. In the case of coating as a coating film, both aqueous and organic solvent-based coating liquids can be used. As the aqueous coating liquid, any resin may be used as long as the resin is dispersed in water, and a water-soluble type, an emulsion type, a suspension type and the like can be used. Further, as the organic solvent-based coating liquid, those prepared using an organic solvent can be used. Examples of the organic solvent include methanol,
Alcohol solvents such as ethanol, isopropanol and butanol; ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane; alicyclic solvents such as cyclohexane Hydrocarbon solvents, ester solvents such as ethyl acetate, ether solvents such as isopropyl ether and tetrahydrofuran, amide solvents such as dimethylformamide, halogenated hydrocarbon solvents such as chloroform and cycloloethane, and the like, and mixed solvents thereof And the like. When the conductive elastic layer is a foam, the use of an aqueous coating liquid does not cause the foam to swell, so that the surface roughness of the conductive member can be reduced, which is preferable. In addition, other additives such as a cross-linking agent can be appropriately added to the resin material or the rubber material forming the conductive coating layer, if necessary, in addition to the electronic conductive material.

The role of the conductive coating layer is to cover the outer periphery of the conductive elastic layer with this layer, thereby lowering the electric resistance of the conductive member as compared with the case where only the conductive elastic layer is used. The reason why the electric resistance of the conductive member formed by covering the conductive elastic layer with the conductive coating layer is reduced is that when the conductive member is brought into contact with another member, the contact portion of the conductive elastic layer is In addition to the current that flows in the vicinity, the current that flows away from the contact portion of the conductive elastic layer flows through the conductive coating layer,
As a result, it is assumed that the resistance of the conductive member is reduced. In the present invention, the volume resistivity ρ2 of the conductive coating layer
Is set to be lower than the volume resistivity ρ1 of the conductive elastic layer for this reason. It is preferable that the volume resistivity ρ1 and the volume resistivity ρ2 have a relationship of logρ2 ≦ logρ1-1. That is, the volume resistivity ρ2 of the conductive coating layer is one unit smaller than the volume resistivity ρ1 of the conductive elastic layer.
It is preferably smaller than an order of magnitude. In particular, it is preferable that it is smaller by two digits or more. In addition, the role of the conductive coating layer is to be able to suppress a change in electric resistance of the conductive member due to an environmental change as compared with the case where only the conductive elastic layer is used. The reason why such a change in electric resistance can be suppressed is that the conductive coating layer is conductive by an electronic conductive material, and therefore, the resistance change due to an environmental change is different from the conductive elastic layer that is conductive by an ionic conductive material. This is presumed to be due to the inverse correlation resulting in the offset of the resistance change.

[0011] The electric resistance of the conductive member of the present invention.
When evaluating the magnitude of the pressure dependence, 10
The resistance when a DC voltage of 0 V is applied is represented by R₁₀₀(Ω),
The resistance when a 500 V DC voltage is applied is represented by R
₅₀₀R when (Ω)₁₀₀/ R_{50 0}To ask for
The voltage dependency can be evaluated more. R₁₀₀/ R
₅₀₀Is closer to 1, the smaller the voltage dependency is. R
₁₀₀/ R₅₀₀Is preferably in the range of 1-2, and 1
~ 1.5 is particularly preferred. In addition, the conductive member of the present invention
When evaluating the environmental dependence of electrical resistance in
Resistance of conductive members in humidity (32.5 ° C, 85% RH)
To R_high(Ω), low temperature and low humidity (10 ° C, 15% RH)
The resistance of the conductive member_lowR when (Ω)
_low/ R_highEnvironmental dependency by asking for
be able to. In the conductive member of the present invention, R_low
/ R_highCan be 1 to 10. Environmental dependency
R as an index_low/ R_highExceeds 10
Needs means to control the conductivity of conductive members
Which leads to an increase in complexity and cost of the image forming apparatus.
I will.

The volume resistivity of the conductive member of the present invention can be set to 10 ⁵ Ω · cm to 10 ¹⁰ Ω · cm. Therefore, the conductive member of the present invention is useful as a developing member, a charging member, a transfer member, an intermediate transfer member, a developer layer forming member, a developer conveying member, a roller, a belt, a drum, a blade, and the like as a cleaning member. The volume resistivity of the conductive member can be appropriately selected according to the image forming apparatus to which the conductive member is mounted. When the conductive member of the present invention is used for such a purpose, the frictional force is controlled on the outer periphery of the conductive coating layer as long as the effect of the present invention is not impaired. A surface coating layer having various functions such as non-staining or developer charge control can be formed. In this case, the surface coating layer can be formed in the same manner using the same resin as the conductive coating layer. The thickness of the surface coating layer is preferably from 1 to 20 μm, particularly preferably from 2 to 10 μm.

[0013]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, about the roller etc. obtained by the Example and the comparative example, the characteristic test was performed as follows. (1) Resistance of conductive member The surface of the aluminum tube was plated with gold to form an electrode drum, and the conductive member was 500 g each on one end of the shaft end.
g of the electrode drum with a load of 20 g.
The conductive member was driven to rotate by rotating at rpm. In this state, the current value when an arbitrary voltage was applied between the electrode drum and the conductive member shaft from the DC voltage power supply was measured, and the resistance value was calculated. Regarding the resistance value in each environment, the conductive member was subjected to high temperature and high humidity (32.5 ° C., 85%
RH), normal temperature and normal humidity (22 ° C., 50% RH) or low temperature and low humidity (10 ° C., 15% RH) for at least 24 hours, and then apply a DC voltage of 100 V to measure the current value. The resistance value was calculated from the current value and the voltage. (2) Volume resistivity of conductive elastic layer Urethane rubber used for forming the elastic layer of each conductive member. The raw material was cast into a flat mold and cured under the same conditions as the respective conductive members to obtain a urethane rubber sheet having a thickness of 5 mm. The resistance of this sheet was measured and defined as the volume resistivity of the conductive elastic layer. (3) Volume Specific Resistance of Conductive Coating Layer A copper plate was prepared, the coating liquid used for forming the coating layer of each conductive member was applied on the copper plate, and dried under the same conditions as each conductive member. The resistance between the copper plate and the measurement electrode was measured and defined as the volume specific resistance of the conductive coating layer.

Example 1 Polyether polyol having a weight average molecular weight of 7,000
(OH value: 18 mg KOH / g) Perchlorine in 100 parts by weight
Contains 0.5 part by weight of sodium acid salt and 0.5 part by weight of black pigment
These are mixed using a mixer, and the polyol composition
Was prepared. The polyol composition was stirred under reduced pressure for 30 minutes.
After stirring and defoaming, crude MDI (crude meta-xylylene
Diisocyanate) (NCO weight%: 30.9) to 6.47
Parts by weight and 0.004 parts by weight of dibutyltin dilaurate
And stirred for 3 minutes. Next, this was added to a diameter of 6 mm and a length of 25.
Place 8mm metal shaft and heat to 100 ℃ in advance
Cast at 75 ° C for 10 hours.
A conductive elastic layer was formed on the outer periphery of the roller to obtain a roller. Get
The thickness of the conductive elastic layer of the set roller is 3 mm, and the conductive elastic layer
The volume resistivity ρ1 of the layer is 2.7 × 10⁸Ω · cm
Was. Next, a water-dispersed urethane resin (solid content: 25%, glass
Transition temperature Tg: −40 ° C.)
Li-based conductive whiskers (fiber length: 10-20 μm,
(Fiber diameter: 0.4 to 0.7 μm)
A working solution was prepared. Immerse the above roller in this coating liquid
Pull it up and dry it at 100 ° C for 2 hours after air drying
Form a more conductive coating layer to obtain a roller-shaped conductive member
Was. The thickness of the conductive coating layer of the conductive member is 20 μm,
The volume resistivity ρ2 of the conductive coating layer is 3.6 × 10^FiveΩ ・ c
m. For the obtained conductive member, the applied voltage is
When the current flowing at that time was measured,
The relationship between the applied voltage and the current is substantially linear as shown in FIG.
Was. The resistance R when the applied voltage is 100 V
₁₀₀(Ω) and the resistance when the applied voltage is 500 V₅₀₀
(Ω) ratio R₁₀₀/ R₅₀₀Was 1.39. Further
In addition, the applied voltage was set to 100 V, and the temperature and humidity (32.5 ° C,
85% RH), room temperature and normal humidity (20 ° C, 50% RH) and low
In each environment of temperature and humidity (10 ° C, 15% RH), conductive part
When the electrical resistance of the material was measured, as shown in Table 1,
Environment-dependent, stable conductive member
It has been certified. To compare the magnitude of environmental dependence,
Ratio R between resistance under humidity and resistance under low temperature and low humidity
_low/ R_highWas 5.5. Example 2 In Example 1, the conductive material contained in the conductive coating layer was
To replace the potassium titanate-based conductive whiskers with F
Same as Example 1 except that 30 parts by weight of T carbon was used
Thus, a roller-shaped conductive member was obtained. Of this conductive member
The volume resistivity ρ2 of the conductive coating layer is 2.6 × 10⁶Ω ・ c
m. For the obtained conductive member, the applied voltage is
When the current flowing at that time was measured,
The relationship between the applied voltage and the current is substantially linear as shown in FIG.
Was. Also, R₁₀₀/ R₅₀₀Was 1.35. Further
Next, the electrical resistance of the conductive member was measured in each environment.
In addition, as shown in Table 1, environmental dependency is small and stable.
It was confirmed that it was a conductive member. R_{lo w}/ R_highIs
It was 4.4.

Comparative Example 1 In the same manner as in Example 1, except that 20 parts by weight of Ketjen black carbon was used instead of sodium perchlorate as the conductive material to be contained in the conductive elastic layer, Was obtained. The volume resistivity ρ1 of the conductive elastic layer of the conductive member is 1.6 × 10 ⁷ Ω · cm.
Met. With respect to the obtained conductive member, when the applied voltage was changed and the current flowing at that time was measured, the relationship between the applied voltage and the current showed a sharp increase in the current value with the applied voltage as shown in FIG. It was observed. Also, R ₁₀₀ /
R ₅₀₀ was 2.52. Further, when the electric resistance of the conductive member was measured under each environment, it was confirmed that the environment dependency was very small as shown in Table 1. R _low
/ R _high was 1.4. Comparative Example 2 A roller-shaped conductive member was obtained in the same manner as in Example 2, except that the amount of FT carbon to be contained in the conductive coating layer was changed to 20 parts by weight. The volume resistivity ρ2 of the conductive coating layer of this conductive member is 4.8 × 10 ⁸ Ω ·
cm and did not satisfy ρ2 <ρ1. With respect to the obtained conductive member, when the applied voltage was changed and the current flowing at that time was measured, the relationship between the applied voltage and the current suddenly increased with the applied voltage as shown in FIG. It was observed. R ₁₀₀ / R ₅₀₀ is 2.
37. Further, when the electric resistance of the conductive member was measured under each environment, it was confirmed that the environment dependency was large as shown in Table 1. R _low / R _high was 11. Comparative Example 3 A conductive member having only the conductive elastic layer of Example 1 without forming the conductive coating layer was used. With respect to the obtained conductive member, when the applied voltage was changed and the current flowing at that time was measured, the relationship between the applied voltage and the current was almost a straight line as shown in FIG. R ₁₀₀ / R ₅₀₀ is 1.33
Met. Further, when the electric resistance of the conductive member was measured under each environment, it was confirmed that the environment dependency was large as shown in Table 1. R _low / R _high was 10.

[0016]

[Table 1]

[0017]

According to the conductive member of the present invention, the electric resistance is substantially constant irrespective of the magnitude of the applied voltage, so that the current can be easily controlled, and the electric resistance is less dependent on the environment. It is suitable as a conductive member to be mounted on an electrostatic recording device.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between an applied voltage and a current in a conductive member of an electronic conductive system.

FIG. 2 is a graph showing a relationship between an applied voltage and a current in a conductive member of an ion conductive system.

FIG. 3 is a schematic sectional view showing an example of the conductive member of the present invention.

FIG. 4 is a graph showing a relationship between an applied voltage and a current in the conductive member of Example 1.

FIG. 5 is a graph showing a relationship between an applied voltage and a current in the conductive member of Example 2.

FIG. 6 is a graph showing a relationship between an applied voltage and a current in the conductive member of Comparative Example 1.

FIG. 7 is a graph showing a relationship between an applied voltage and a current in a conductive member of Comparative Example 2.

FIG. 8 is a graph showing a relationship between an applied voltage and a current in a conductive member of Comparative Example 3.

[Explanation of symbols]

 1: conductive support 2: conductive elastic layer 3: conductive coating layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/06 H01B 1/20 B 5G301 H01B 1/20 1/22 B 1/22 1/24 B 1 / 24 G03G 21/00 340 (72) Inventor Takahiro Kawagoe 1302-57 Aobadai, Tokorozawa-shi, Saitama F-term (reference) 2H003 BB11 BB14 BB16 CC05 2H032 AA05 BA08 BA16 2H035 AA15 3J103 AA02 AA14 AA33 AA51 GA41 GA02 GA41 GA64 GA66 GA68 GA73 GA74 HA03 HA04 HA05 HA12 HA19 HA20 HA32 HA33 HA37 HA41 HA45 HA48 HA53 HA54 HA55 HA60 4J002 AC071 AC091 BG041 CH041 CK021 DE196 EN136 FD116 GQ02 GT00 5G301 DA01 DA18 DA22 DA28 DA42 DA53 DA59 DD08 DD10

Claims (12)

[Claims] 1. A conductive member having a structure in which a conductive coating layer is laminated on a conductive elastic layer, wherein the conductive elastic layer is made of a polar rubber containing at least an ionic conductive material. When the volume resistivity is ρ1 and the volume resistivity of the conductive coating layer is ρ2, ρ2 <ρ
1. A conductive member, which is 1. 2. A volume resistivity ρ1 of 10 ⁷ to 10 ¹⁰ Ω ·
The conductive member according to claim 1, wherein cm, volume resistivity ρ2 is 10 ¹ to 10 ⁸ Ω · cm, and log ρ2 ≦ log ρ1-1. 3. The conductive member has a voltage of 100 V
R ₁₀₀ (Ω) when the DC voltage of
The electric resistance when a DC voltage of 500 V is applied is R ₅₀₀
The conductive member according to claim 1, wherein R ₁₀₀ / R ₅₀₀ when (Ω) is in the range of 1 to 2. 4. High temperature and high humidity (32.5 ° C., 85% R)
H) is R _high (Ω), and R _low / R _high is 1 when the electrical resistance of the conductive member at low temperature and low humidity (10 ° C., 15% RH) is R _low (Ω).
The conductive member according to claim 3, which is in a range of from 10 to 10. 5. The conductive member according to claim 1, wherein the polar rubber is at least one selected from urethane rubber, epichlorohydrin rubber, and nitrile rubber. 6. The conductive member according to claim 1, wherein the ionic conductive material is an inorganic ionic conductive material or an organic ionic conductive material. 7. The conductive member according to claim 1, wherein the conductive coating layer has a thickness of 3 to 300 μm. 8. The conductive member according to claim 1, wherein the conductive coating layer is made of a resin or rubber containing an electronic conductive material. 9. The conductive member according to claim 8, wherein the electronic conductive material is a conductive whisker. 10. The conductive member according to claim 8, wherein the resin is at least one selected from a urethane resin, a polyester resin, and an acrylic resin. 11. The conductive member according to claim 8, wherein the rubber is at least one selected from urethane rubber, epichlorohydrin rubber, and nitrile rubber. 12. An image forming apparatus comprising the conductive member according to claim 1.