JPH11190928A - Electrifying member and image forming device using that - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrifying member having little irregularity in resistance with which uniform electrification property is obtd., which shows little changes after repeated use, which is not adhesive, which does not cause sticking to a photoreceptor or contamination, and which shows little variance among production lots, and to provide an electrophotographic device using this member. SOLUTION: The electrifying member 2 with voltage applied is used to electrify the surface of a body not electrified. In this process, a conductive elastic material which constitutes the electrifying member consists of an epichlorohydrin rubber or, if necessary, a vulcanized compd. prepared by mixing and vulcanizing 6-methylquinoxaline 2,3-dithiocarbonate, nitrile rubber and nonpolar polymer. Further, hydrotalcite is incorporated into the vulcanized product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member used in an electrophotographic apparatus, and more particularly, to a charging member for charging, developing, transferring, etc., which charges a surface of an object to be charged with a charging member to which a voltage is applied. The present invention relates to an electrophotographic apparatus using the same.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus such as a copying machine or an optical printer, as a device for charging a surface of an image carrier as an object to be charged such as a photoconductor or a dielectric. Has conventionally used a corona charger.

A corona discharge device is effective as a means for uniformly charging a surface of an object to be charged such as an image carrier to a predetermined potential. However, since a high-voltage power supply is required and corona discharge is used, there is a problem that undesired ozone is generated.

A contact charging device for charging a surface of a charged object by bringing a charging member to which the above-described voltage is applied close to or in contact with the charged object with respect to the corona discharge device described above,
The power supply can be reduced in pressure and has advantages such as a small amount of ozone generated.

[0005] Such a charging member is required to be semiconductive in order to prevent the leakage caused by pinholes or scratches on the surface of the charged object such as the photoreceptor, etc.

For example, in the case of a transfer roller used in an image forming apparatus such as a copying machine, the transfer roller is a member for transferring a toner image on an image carrier such as a photoreceptor, an intermediate transfer member, and a transfer drum onto transfer paper. The transfer roller is pressed against the photoreceptor or the like on which the toner image has been developed via the transfer paper as a charged body to supply a charge having a polarity opposite to that of the toner of the toner image, thereby transferring the toner of the photoreceptor or the like to the paper. While the image is adsorbed and transferred, the magnitude of the charge density supplied to the transfer paper has a great effect on the image quality. That is, if the charge density is low, the toner adsorbing power is weakened.
In contrast, when the amount is large, "bleeding" occurs due to the opposite polarity charging of the toner, and a high quality image cannot be obtained.

[0007] Further, if the charge density is non-uniform, uneven density occurs in the solid black transferability, and uneven transfer occurs on spots such as sand. Therefore, it is desired that the conductivity of the surface be uniform.

[0008] In response to this requirement, carbon black, graphite, titanium oxide,
Metal oxides such as tin oxide, metal powders such as Cu and Ag, and conductive rubber rollers in which conductive particles such as particles obtained by coating the surfaces of these particles and dielectricizing them are used.

However, the rubber roller in which the conductive particles are dispersed needs to disperse a large amount of the conductive particles in order to adjust the resistance value thereof. As a result, there has been a problem that charging unevenness is caused or the photosensitive member is destroyed due to a partial leak.

[0010] In addition, as conductive means other than conductive particles, L
An ion conductive rubber whose resistance value is adjusted by adding an ionic electrolyte such as iClO ₄ , NaSCN, LiCFSO ₄ or the like is used.

In this case, there is a problem that the electrolyte migrates to the surface and the resistance value changes with time, the photosensitive member is contaminated, or the resistance is changed by charging up by applying a voltage.

On the other hand, a method for obtaining conductivity using hydrin rubber has been widely used, in particular, because good uniform conductivity can be obtained without a conductive additive. The hydrin rubber uses various acid acceptors to absorb halogens such as hydrogen chloride generated during vulcanization. However, magnesium oxide, for example, is inferior in dispersibility, tends to cause variations in physical properties, has a large hygroscopic property of the powder itself, and has a problem of wettability after vulcanization. Zinc oxide is not practical because of low reactivity and poor physical properties. In addition, calcium hydroxide has a poor pot life of the material.
Although trilead tetroxide as disclosed in No. 30 has excellent reactivity, its use amount has been restricted because it contains heavy metals.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a small resistance unevenness, a uniform charging property, a small fluctuation due to durability, and a non-adhesive property with a photosensitive member. An object of the present invention is to provide a charging member having no sticking property and no contamination and having a small variation in a production lot, and an electrophotographic apparatus using the same.

[0014]

The above object is achieved by the following means.

That is, the present invention relates to a charging member for charging a surface of an object to be charged by applying a voltage to the charging member.
The elastic body constituting the charging member is a vulcanized product obtained by mixing and vulcanizing epichlorohydrin rubber, and the vulcanized product contains hydrotalcite. Furthermore,
It is constituted by mixing and vulcanizing 6-methylquinoxaline 2,3 dithiocarbonate, and is further constituted by mixing and vulcanizing a nitrile rubber and a non-polar polymer. Further, the non-polar polymer is constituted as EPDM.

[0016] The method also includes irradiating the surface of the charging member with ultraviolet light.

Further, the present invention proposes an electrophotographic apparatus characterized by using the above charging member.
The charging member may be a transfer roller.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The present invention is characterized in that a mixed vulcanizate of epichlorohydrin rubber containing hydrotalcite is used as a conductive elastic material on a conductive substrate.

In other words, when epichlorohydrin rubber is used as the polymer used for the elastic body, the localization mechanism is caused by the material polymer itself. It is known that typical resistance value unevenness is small.

Further, when hydrin rubber is used, a double bond is not included in the bond, so that the material is hardly changed due to the application of a voltage. In addition, since there is a characteristic that deterioration due to oxygen, ozone, or the like is unlikely to occur, stability due to durability can be expected.

Further, the use of hydrotalcite as an acid acceptor is preferable for the following reasons. That is, hydrotalcite has a structural formula of Mg _1-x Al _x
(OH) ₂ (CO ₃ ) _{x / 2} · mH ₂ O (0 <x ≦ 0.5, m
Is a basic magnesium / aluminum / hydroxide / carbonate / hydrate represented by the following formula: Hydrogen chloride generated in the reaction process is easily replaced by carbonate ion in the water-containing layered compound, and chloride ion Is incorporated into the crystal structure. Unlike the other metal chlorides, the resulting compound is insoluble in water. Furthermore, it is excellent in dispersibility, and therefore hardly affects the physical properties due to the kneading state and processing. In addition, Mg _1-x Al _x O _{1 + x / 2} obtained by treating the above compound at a high temperature similarly adsorbs anions together with water, and thus has the same effect.

Ethylenethiourea, which is used as a crosslinking agent because of its high reactivity, is pointed out for its teratogenicity, carcinogenicity, and the like.

As an alternative to ethylenethiourea, a 2,3-dimethylquinoxaline derivative is preferred, and in particular, 6-methylquinoxaline 2,3-dithiocarbonate is suitable as having both reactivity and work safety.

It is also effective to mix and cure nitrile rubber. This is because blending of the nitrile rubber improves the level of settling due to long-term pressure contact, and also improves processability such as extrusion.

The nitrile content of the nitrile rubber used is preferably 45% by weight or less and 15% by weight or more.
If it is 45% by weight or more, the polarity becomes strong, so that the tackiness becomes large, the compatibility with the non-polar polymer becomes poor, and the physical properties of the mixed vulcanizate are deteriorated. Further, permanent deformation after long-term pressing becomes large, and in the case of a transfer roller, the transferability of the transfer material is affected, resulting in poor transfer. On the other hand, if the content is less than 15% by weight, adverse effects such as poor conductivity and ozone deterioration are likely to occur.

Further, polymers having strong polarity such as hydrin rubber generally have strong adhesiveness. Mixing and vulcanizing a non-polar polymer is also effective in increasing the level of tackiness after long-term pressure contact with a member to be charged such as a photoreceptor. Here, the non-polar polymer is a polymer having no large dipole moment in the molecule, and generally a polymer having a small dielectric constant.

Specific examples of such nonpolar polymers include NR (IR) (isoprene rubber), BR (butadiene rubber), SBR (styrene butadiene rubber), and EP
DM (ethylene propylene diene terpolymer), II
R (butyl rubber), olefin elastomer, SEBS
Elastomers and polystyrene elastomers. In addition, by blending these polymers, it is possible to adjust the resistance to the high resistance side, and it is possible to cope with various resistance specifications of the electrophotographic apparatus.

In particular, when weather resistance such as ozone resistance is a problem, and when aging resistance is taken into consideration, the use of EPDM is suitable. Particularly in the case of sulfur vulcanization, the iodine value of EPDM used is preferably 20 or more, and more preferably 30 or more, from the viewpoint of co-vulcanization.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 3 is an example of a schematic sectional view showing the configuration of a transfer roller according to the present invention.

In the transfer roller of this embodiment, a semiconductive elastic layer 32 is provided on a cylindrical conductive cylindrical base material 31 made of metal or the like.

In the present invention, the semiconductive elastic layer is not particularly limited as long as it can apply a transfer bias voltage to the paper and has elasticity enough to uniformly press the paper against the paper. Is the volume resistance value 1E + 5Ω to 1E
It has about + 12Ω.

In addition, it is preferable that the nip width with the member to be charged is sufficient to obtain a uniform charge, and particularly in the case of a transfer member, low hardness is preferable as a countermeasure against "center missing" in which the central portion of the line drawing comes off.

Liquid NBR is particularly effective for reducing the hardness. That is, since liquid NBR has the same molecular structure as nitrile rubber, it has good compatibility with nitrile rubber and excellent non-migratory properties. Further, the hardness can be reduced without affecting the resistance value.

The degree of low hardness is expressed as sponge hardness (a
(kerC) is preferably in the range of 20 ° to 80 °.

As a use form, a solid or foam may be used.

The fixability to a non-charged member such as a photoreceptor can be improved by blending with a polymer. As a means for further improvement, surface modification can be considered.

For example, blending of release particles such as silicone particles and fluororesin particles, surface treatment with a coupling agent or a reactive fluorine-based surfactant, surface cleaning with a chlorine-based solvent such as dilute hydrochloric acid and the like can be mentioned.

However, UV (ultraviolet) irradiation treatment is particularly preferred from the viewpoint of simplicity and effectiveness of the treatment. This has the effect of oxidizing the rubber surface and de-adhering the surface by a crosslinking reaction between diene bonds. Further, it is also preferable that the influence on physical properties is small as compared with an additive or a coating treatment.

The wavelength as the UV irradiation condition is 180 nm
It is preferably in the range of -600 nm. The irradiation intensity is preferably in the range of 10 mW / cm @ 2 to 100 mW / cm @ 2.

When the charging member is in the form of a roller, if the irradiation is performed while rotating the roller, UV is uniformly applied to the entire surface, and the treatment can be performed effectively in a short time.

In addition, this treatment imparts high releasability to the surface of the charging member, so that excess toner and paper dust that have adhered can be easily cleaned.

FIG. 1 is a cross-sectional view of a schematic configuration of an electrophotographic apparatus using the charging member according to the present invention. The rotary photoreceptor 1 is an image carrier as a member to be charged. In this embodiment, a drum-type photoreceptor having a conductive base layer 1b of aluminum or the like and a photoconductive layer 1a formed on the outer peripheral surface thereof as a basic constituent layer is used. It is an electrophotographic photosensitive member. It is driven to rotate around the support shaft 1d clockwise in the drawing at a predetermined peripheral speed.

The charging member 2 is a charging member that contacts the surface of the rotating photoreceptor 1 to perform a primary charging process on the photoreceptor surface to a predetermined polarity and potential uniformly, and is required to have uniform conductivity. This example is of a roller type. The charging member 2 includes a center metal core 2c and a lower conductive elastic layer 2b formed on the outer periphery thereof.
And an upper resistive layer 2a formed on the outer periphery thereof, and both end portions of the cored bar 2c are driven by the pressing means (not shown) as the rotary photosensitive member 1 is driven to rotate. It is also effective to use the material of the present invention for the resistance layer 2a and the conductive elastic layer 2b.

A predetermined direct current (DC) bias or a direct current + alternating current (DC + AC) bias of the metal core 2c is applied by the rubbing power source 3a of the power source 3, so that the peripheral surface of the rotary photosensitive member 1 is predetermined. Contact charge to the polarity and potential of The surface of the rotating photoreceptor 1 which has been uniformly charged by the charging member 2 is then subjected to exposure of target image information (laser beam scanning exposure, document image slit exposure, etc.) by the exposure means 10 so that the peripheral surface thereof has image information. , An electrostatic latent image is formed.

The latent image is then sequentially visualized as a toner image by the developing means 11. Next, the toner image is periodically cycled from a paper feeding unit (not shown) by the transfer unit 12 to the rotation of the rotary photoconductor 1 and is conveyed to the transfer unit between the rotary photoconductor 1 and the transfer unit 12 at an appropriate timing. Are sequentially transferred to the surface of the transferred transfer material 14.

The transfer means 12 in this embodiment is a transfer roller, and the surface of the rotating photoconductor 1 is transferred to the front side of the transfer material 14 by performing charging of a polarity opposite to that of the toner from the back of the transfer material 14.

The transfer material 14 to which the toner image has been transferred is separated from the surface of the rotating photoreceptor 1, conveyed to an image fixing means (not shown), subjected to image fixing, and output as an image formed product. Alternatively, in the case of forming an image on the back surface, the sheet is conveyed to a re-conveying unit to the transfer unit.

After the image is transferred, the surface of the rotating photoreceptor 1 is cleaned by the cleaning means 13 to remove adhered contaminants such as untransferred toner, and is repeatedly provided for image formation.

The charging member 2 may be of a blade type, a block type, a rod type, a belt type, or the like in addition to the roller type which is used as a charging unit for the image carrier 1 in the image forming apparatus of FIG. Can be configured.

The roller-type charging member 2 may be driven by the rotating photosensitive member 1 driven to move in a plane, may be non-rotating, or may be in the forward direction in the surface moving direction of the rotating photosensitive member 1. Alternatively, the motor may be positively driven to rotate at a predetermined peripheral speed in the opposite direction.

In the electrophotographic apparatus, among the components such as the above-described photosensitive member, developing means, and cleaning means,
A plurality of process cartridges may be integrally connected as a process cartridge, and this process cartridge may be configured to be detachable from an image forming apparatus main body, for example, a copying machine, a laser beam printer, or the like. For example, at least one of the charging unit, the developing unit, and the cleaning unit is integrally supported together with the photoreceptor to form a cartridge, and the process cartridge is detachable from the apparatus main body. May be adopted. At this time, the process cartridge may be provided with a charging unit and / or a developing unit.

In the case of using an electrophotographic apparatus as a copier printer, the light image exposure is performed by reflecting light or transmitted light from an original, or reading the original and converting it into a signal. , Or by driving a liquid crystal shutter array.

When used as a facsimile printer, light image exposure is exposure for printing received data. FIG. 2 is a block diagram showing an example of this case. The controller 21 controls the image reading unit 20 and the printer 29. The controller 21 is controlled by the CPU 27. The read data from the image reading unit is sent to the printer 29 through the transmission circuit 23. Predetermined image data is stored in the image memory. The printer controller 28 controls a printer 29. 24 is a telephone.

The image received from the circuit 25 (image information from a remote terminal connected via a line) is demodulated by the receiving circuit 22, and then the CPU 27 performs a composite processing of the image information and sequentially stores it in the memory 26. Is done. When the image of at least one page is stored in the memory 26, the image of the page is recorded. The CPU 27 reads out one page of image information from the memory 26 and sends out the combined one-page image information to the printer controller 28.
The printer controller 28 receives 1
When the image information of the page is received, the printer 29 is controlled to record the image information of the page.

The CPU 27 is receiving the next page during recording by the printer 29. Image reception and recording are performed as described above.

The photosensitive member is provided on a conductive support. As the conductive support, there can be used a support having conductivity itself, for example, a metal such as aluminum, aluminum alloy, stainless steel, nickel, etc., such as aluminum, aluminum alloy, indium oxide-tin oxide and the like. , Glass, etc. having a layer formed by vacuum evaporation.

An undercoat layer having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer.

The undercoat layer can be formed of casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon, etc.), polyurethane, gelatin, aluminum oxide and the like. The thickness of the undercoat layer is 5 μm or less, preferably 0.5 to 3 μm.
Is appropriate. The undercoat layer desirably has a thickness of 1E + 7 Ω · cm or more in order to exhibit its function.

The photosensitive layer can be formed by applying an organic or inorganic photoconductor together with a binder resin as necessary, or can be formed by vapor deposition.

The form of the photoreceptor is preferably a function-separated type photosensitive layer having a charge generation layer and a charge transport layer.

The charge generation layer can be formed by depositing a charge generation substance such as an azo pigment, a phthalocyanine pigment, a quinone pigment or the like, or by coating with a suitable binder resin (without a binder).

The thickness of the charge generation layer is 0.01 to 30 μm.
m, particularly preferably in the range of 0.05 to 2 μm. The charge transport layer can be formed by dissolving a charge transport substance such as a hydrazone compound, a styryl compound, an oxazole compound, or a triarylamine compound in a binder resin having a film-forming property. The thickness of the charge transport layer is 5
-50 μm, particularly preferably 10-30 μm. Note that a protective layer may be provided on the photosensitive layer to prevent deterioration due to ultraviolet light or the like.

Hereinafter, embodiments of the present invention will be described.

Example 1 FIG. 3 is a sectional view of a transfer roller according to the present invention, wherein 32 is a semiconductive elastic body, and 31 is a conductive cylindrical base material.

A semiconductive elastic layer 32 is formed on a core made of a conductive columnar substrate 31 of 6 mm in diameter made of stainless steel, iron, or iron whose surface is nickel or nickel-chrome plated for rust prevention. A roller consisting of

The material of the elastic body is 40 parts of Epichromer H (epichlorohydrin 100%: manufactured by Daiso Corporation) as hydrin rubber, 40 parts of N240S (nitrile content 26%: manufactured by Nippon Synthetic Rubber Co., Ltd.) as NBR, E
EPT4070 as PDM (iodine value 22: Mitsui Petrochemical Co., Ltd., trade name) 20 parts, hydrotalcite _{(Mg 4.3 Al 2 (OH)} 12.6 CO 3 · mH 2 O) 3 parts of zinc oxide, 3 parts of stearic 2 parts acid, calcium carbonate 40
Parts, liquid NBR 20 parts, sulfur 0.5 part, 6-methylquinoxaline 2.3 dithiocarbonate 1.2 parts, vulcanization accelerator DM 2 parts, and TRA 1.5 parts were added and kneaded.

This rubber was formed into a tube by extrusion, and primary vulcanization was performed at 160 ° C. and 30 ° C. by steam vulcanization.
And secondary vulcanization in an electric furnace at 150 ° C for 3 minutes.
After 0 minutes, a vulcanized product was obtained. The tube thus formed was pressed into a core metal coated with an adhesive and polished to obtain an elastic roller having a diameter of 16 mm.

The resistance value of the obtained elastic roller was measured using an apparatus shown in FIG. 4 while rotating the aluminum drum. The resistance value was measured by applying a DC voltage of 2 kV after standing for 24 hours in an NN environment. The variation of the resistance value in the same lot was 1.39E + 8 to 1.49E + 8Ω (1.07 times), and the hardness was 61 ゜ askerC. As a measure of the reactivity, tc50 of the curast meter ((max. Torque-m
in. (Torque) * 50% time / 160 ° C.) before and after extrusion did not change. In FIG. 4, 41 is a semiconductive roller, 42 is an aluminum drum, 43 is a conductive metal core, and 44 is an ammeter.

Evaluation was performed using the electrophotographic apparatus shown in FIG. 1 with the above roller as a transfer roller. The process speed is 100 mm / sec. The diameter of the photosensitive drum is 30mm
It is. The photosensitive drum is negatively charged OPC, the toner is positively charged, and the voltage applied to the transfer roller is -3k during transfer.
V, +1.5 kV during cleaning.

When the line drawing, solid black, and halftone image were evaluated using a dryer with the above rollers, the L / L (10
° C, 15% R.C. H. ) To (32.5 ° C, 80% R.I.
H. A good image was obtained under any of the above conditions.

When a double-sided transfer image was evaluated using dry paper in an L / L environment, a clear image was obtained.

Further, the durability was evaluated continuously for 200,000. However, no image defect occurred due to the change in the resistance value. In addition, there was no problem on the image due to the change in the outer diameter of the roller.

Next, at 40.degree. H. In this environment, the organic photoreceptor was pressed against the organic photoreceptor at a total pressure of 1 kg and left for 2 weeks. No adverse effects such as sticking occurred.

Further, this roller is connected to an ultraviolet irradiation device (1).
40nW using 85nm and 245nm wavelength main components)
/ Cm ＾ 2 for 4 minutes and the resulting roller
° C, 95% R.C. H. Photoreceptor and total pressure 1kg
When pressed under a load and left for 30 days, no adverse effects such as sticking occurred. Next, using this photoreceptor, image evaluation was performed under an N / N environment, and a good image was obtained without any trace of contact.

Comparative Example 1 A roller was obtained in the same manner as in Example 1 except that 3 parts of MgO was used as an acid acceptor and 1.2 parts of ethylenethiourea was used as a vulcanizing agent. Regarding the physical properties of the obtained roller, the variation of the resistance value in the same lot was 1.87E + 8 to 2.95E +
It has increased to 8Ω (1.57 times). Hardness is 6
0 ° askerC. Other evaluations were the same as in Example 1.

As a measure of the reactivity, tc50 ((max. Torque-min. Torque) * 50 of the curast meter)
% Time / 160 ° C.) before and after extrusion, it was 2.8 times longer. That is, there was a large variation in physical properties due to fluctuations in processing conditions, and the formulation was not productive.

Example 2 A roller was prepared in the same manner as in Example 1 except that 3 parts of hydrotalcite was used as an acid acceptor and 1.5 parts of 2,4,6-trimercapto-S-triazine was used as a vulcanizing agent. I got
Regarding the physical properties of the obtained roller, the variation of the resistance value within the same lot was 2.66E + 8 to 2.88E + 8Ω (1.08E).
Times) and good. Hardness was 63 ° askerC. Other evaluation results were the same as in Example 1.

As a measure of the reactivity, tc50 of the curast meter ((max. Torque-min. Torque) * 50)
% Time / 160 ° C.) before and after extrusion.

Example 3 To the formulation of Example 1, 8 parts of oxybisbenzenesulfonylhydrazine was added as a blowing agent, and the secondary vulcanization condition was 160
A roller was obtained in the same manner as in Example 1, except that the temperature was 30 ° C. and 30 minutes. Regarding the physical properties of the obtained roller, the variation of the resistance value in the same lot was 3.5E + 8 to 3.8E + 8Ω (1.
09 times). The hardness was 35 ° askerC. Other evaluation results were the same as in Example 1.

As a measure of the reactivity, tc50 of the curast meter ((max. Torque-min. Torque) * 50)
% Time / 160 ° C.) before and after extrusion.

Comparative Example 2 A roller was obtained in the same manner as in Example 3, except that 5 parts of zinc oxide was used as an acid acceptor and 2 parts of ethylenethiourea was used as a vulcanizing agent. Regarding the physical properties of the obtained roller, the variation of the resistance value in the same lot was 5.1E + 8 to 5.6E + 8Ω (1.
1 times). Hardness was 33 ° askerC.

Further, the durability was evaluated continuously for 200,000. As a result, no image defect due to the change in the resistance value occurred. However, the change in the outer diameter (due to the settling) was large, and the paper conveyance force fluctuated. A void occurred.

The other evaluation results were the same as in Example 1.

As a measure of the reactivity, tc50 of the curast meter ((max. Torque-min. Torque) * 50)
% Time / 160 ° C.) before and after extrusion.

[0087]

As described above, in a charging member to which a surface to be charged is charged by applying a voltage to the charging member, an elastic body constituting the charging member is formed by mixing and vulcanizing epichlorohydrin rubber. By containing hydrotalcite in the vulcanized product, a uniform charging property with small resistance unevenness, excellent durability, and a small variation in a production lot can be obtained. further,
By mixing and vulcanizing the nitrile rubber and the non-polar polymer, a charging member which is non-adhesive, has no sticking property to the photoreceptor, and has no contamination is obtained. In addition, by mixing and vulcanizing 6-methylquinoxaline 2,3 dithiocarbonate, a charging member can be obtained in consideration of the working environment during roller production.

Further, by irradiating the surface of the charging member with ultraviolet rays, the non-adhesiveness to the member to be charged is further improved, and the transfer of the additives in the charging member to the surface of the non-charging member is suppressed. As a result, a good image can be obtained even after long-term contact.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus using a charging member of the present invention.

FIG. 2 is a block diagram of a facsimile using an electrophotographic apparatus using the charging member of the present invention in a printer.

FIG. 3 is a schematic cross-sectional view illustrating a configuration of a charging roller of the present invention.

FIG. 4 is a diagram showing a configuration of a device for measuring a resistance value of a semiconductive elastic roller.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotating photoreceptor 1 a photoconductive layer 1 b conductive base layer 1 d support shaft 2 charging member 2 a resistance layer 2 b conductive elastic body 2 c cored bar 3 power supply 3 a rubbing power supply 10 exposure means 11 developing means 12 transfer means 13 cleaning means 14 transfer Materials 18, 28 Printer controller 20 Image reading unit 21 Controller 22 Receiving circuit 23 Transmitting circuit 24 Telephone 25 circuit 26 Memory 27 CPU 29 Printer 31 Conductive cylindrical base material 32 Semiconductive elastic body layer 41 Semiconductive elastic roller 42 Aluminum drum 43 Conductive core bar 44 Ammeter

Claims (8)

[Claims] 1. A charging member for charging an uncharged body surface with a charging member to which a voltage is applied, wherein the conductive elastic body constituting the charging member is a vulcanizate formed by mixing and vulcanizing epichlorohydrin rubber. And a charging member comprising hydrotalcite in the vulcanized product. 2. The charging member according to claim 1, wherein 6-methylquinoxaline 2,3-dithiocarbonate is mixed and vulcanized to the conductive elastic body. 3. The charging member according to claim 1, wherein nitrile rubber is further mixed and vulcanized to the conductive elastic body. 4. The charging member according to claim 1, wherein a non-polar polymer is further mixed and vulcanized to the conductive elastic body. 5. The charging member according to claim 4, wherein said non-polar polymer is EPDM. 6. The charging member according to claim 1, wherein the surface of the charging member is irradiated with ultraviolet rays. 7. An electrophotographic apparatus using the charging member according to claim 1. Description: 8. An electrophotographic apparatus according to claim 7, wherein said charging member is a transfer roller.