JPH0477767A - Electrifying member - Google Patents

Abstract

PURPOSE:To provide the electrifying member which can stably supply high-trade images which are free from image dotty fogging by the nonuniformity of electrification and image defects by the discharge breakdown of a photosensitive body by providing a resin layer contg. a hydroquinone deriv. resin on a conductive elastic layer. CONSTITUTION:This electrifying member is made into the three-layered constitution consisting of the conductive elastic layer 2 provided on a conductive base 1a and further, the resin layer 3 contg. the hydroquinone deriv. resin on the elastic layer 2. Polyvinyl hydroquinone, hydroquinone/phenol/formalin copolymer resin, etc., are preferably used as the hydroquinone deriv. resin. Further, a binder resin may be added to the resin layer. The electrifying member having the resin layer contg. the hydroquinone deriv. resin in such a manner has the low adhesiveness to the electrophotographic sensitive body and has resilience as well and, therefore, the member imparts high image quality, lessens the contamination with toners, and lessens the fluctuation in the volumetric resistance of the resin layer even at and under a low temp. and low humidity. This member is thus usable as the stable electrifying member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a charging member, and more particularly to a charging member used for primary charging, transfer charging, and static elimination charging in electrophotography.

[Conventional technology]

The charging process in the electrophotographic process using an electrophotographic photoreceptor has conventionally applied a high voltage (DC) to a metal wire.
5 to 8 kV) is applied, and charging is performed by the generated corona. However, with this method, corona products such as ozone and NOX change the surface of the photoreceptor when corona occurs, causing blurring and deterioration of the image, and dirt on the wire affects the image quality, resulting in white spots and black lines in the image. There were other problems. On the other hand, in terms of electric power, the current flowing toward the photoreceptor is
The amount was only ~30%, and most of it flowed to the shield plate, making it ineffective as a charging means.

In order to compensate for these drawbacks, many methods of direct charging have been researched and proposed (Japanese Unexamined Patent Publication Nos. 178267-1982, 104351-1980, 5840-1982).
566, JP-A-58-139156, JP-A-58-150975, etc.). However, in reality, even if the photoreceptor is charged by the contact charging method as described above, the surface of the photoreceptor is not uniformly charged at each part, and uneven charging occurs. For example, in the reversal development method, even if a process below photoimage exposure is applied to a photoconductor with spotty charging unevenness, the output image will be a spotty black dot image corresponding to the spotty charging unevenness, whereas in the regular development method, the output image will be a spotty black dot image corresponding to the spotty charging unevenness. In contrast to the unevenness, the image becomes a speckled white dot image, making it impossible to obtain a high-quality image.

Furthermore, although there are many proposals for direct charging, there is no market track record for the direct charging method. The reason for this is the uniformity of charging,
Examples of such problems include the occurrence of discharge dielectric breakdown of the photoreceptor due to direct voltage application. For example, in the case of a cylindrical photoreceptor, one breakdown point due to discharge dielectric breakdown has the disadvantage that the entire charge in the axial direction flows to the breakdown point and is no longer charged.

[Problem to be solved by the invention]

In order to prevent this dielectric breakdown, a method of forming a resin layer on the surface has also been reported. (JP-A-1205180, JP-A-1-211779) However, these materials also have large fluctuations in resistance under low temperature and low humidity conditions, have unstable charging properties, and cannot be used in contact with an organic photoreceptor. The problem was that the resin on the surfaces of the charging member and the charging member became compatible and stuck together.

Therefore, it is an object of the present invention to provide a charging method that can solve the above-mentioned drawbacks and stably provide high-quality images without spotting caused by non-uniform charging or image defects caused by discharge dielectric breakdown of the photoreceptor. The objective is to provide members for use in the field.

(Means for solving the problem) Zunawa, the present invention provides a charging member having a conductive elastic layer on a conductive support, which has a resin layer containing a hydroquinone derivative resin on the conductive elastic layer. This is a charging member characterized by the following.

The present invention will be explained in more detail below.

In the charging member of the present invention, as shown in FIG. 1, a conductive elastic layer 2 is provided on a conductive support la, and a resin layer 3 containing a hydroquinone derivative resin is further provided on the elastic N2. The basic form is a three-layer structure.

In the present invention, as the hydroquinone derivative resin, polyvinylhydroquinone, hydroquinone phenol-formalin copolymer resin, etc. are preferably used.

Furthermore, a binder resin may be added to the resin layer.

However, the amount of binder resin added is preferably 30% by weight or less based on the total resin. Examples of the binder resin in the resin layer include acrylic resins such as polymethyl methacrylate and polybutyl methacrylate, polyvinyl butyral, polyvinyl acecool, polyarylate, polycarbonate, phenoxy resin, polyvinyl acetate, and polyvinylpyridine.

Conventional charging members have surfaces made of rubber or polyurethane, so if they come into contact with an electrophotographic photoreceptor, the photoreceptor and charging member may stick together, or if the surface is hard, wrinkles may occur. Lived image defects.

On the other hand, the charging member having a resin layer containing the hydroquinone derivative resin of the present invention has low adhesion to the electrophotographic photoreceptor and is flexible, so it provides high-quality images.
There is little toner stain, and there is little variation in the volume resistivity of the resin layer even under low temperature and low humidity conditions, so it can be used as a stable charging member.

The thickness of the resin layer is 5 to 500 μm, particularly 20 to 200 μm.
A range of pm is preferred.

As the elastic layer 2, metals such as aluminum, iron, copper, etc., conductive polymers such as polyacetylene, polypyrrole, polythiophene, etc., rubber or plastic elastomer treated to be conductive by dispersing carbon, metal, etc., or the surface of rubber or plastic elastomer can be used. A laminate coated with metal or other conductive material can be used. Moreover, this elastic layer 2 may have a multilayer structure with separate functions as required. As the conductive support 1a, iron, copper, stainless steel, etc. can be used.

Further, as shown in FIG. 2, a protective layer 4 may be provided on the surface of the charging member to protect the charging member. This protective layer is formed of a resin layer, and insoluble resin powder 5 may be mixed therein to control the conductivity and the surface roughness of the charging member.

In the case of a blade-shaped charging member as shown in FIG. 3, a conductive elastic layer 2 is provided on the conductive sheet metal 1b, and a resin layer 3
will be established.

Further, a protective layer may be provided.

The 1F charging member may have any shape such as a roller shape or a plate shape, but a roller shape is preferable in terms of uniform charging.

Electrophotographic photoreceptors basically have a structure in which a photosensitive layer is provided on a conductive support. As the conductive support, materials that are conductive themselves such as aluminum, aluminum alloy, stainless steel, chromium, titanium, etc. can be used. In addition, aluminum, aluminum alloy, indium oxide-tin oxide alloy, etc. can be used. The above-mentioned conductive support having a layer formed by vacuum evaporation, a support made of plastic or paper impregnated with conductive particles (e.g. carbon blank, tin oxide particles, etc.) together with a suitable binder, a conductive binder. It is possible to use plastics having the following characteristics.

A subbing layer having barrier and adhesive functions can also be provided between the conductive support and the photosensitive layer.

The subbing layer is casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer polyamide,
It can be formed from polyurethane, gelatin, aluminum oxide, etc. The thickness of the undercoat layer is suitably 5 μm or less, preferably 0.5 to 3 μm. In order for the undercoat layer to perform its function, it is desirable that the undercoat layer has a resistance of 10 7 Ω·cm or more.

The photosensitive layer is formed, for example, by coating a photoconductor such as an organic photoconductor, amorphous silicon, selenium, etc. together with a binder if necessary, or by vacuum deposition. Furthermore, when using an organic photoconductor, a photosensitive layer consisting of a combination of a charge generation layer that generates charge carriers upon exposure to light and a charge transport layer that has the ability to transport the generated charge carriers can also be effectively used.

The charge generating layer may be formed by depositing one or more charge generating materials such as azo pigments, quinone pigments, quinone anine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, and quinacitrine pigments, or by depositing a suitable material. It can be formed by dispersing it with a binder (°ζ without a binder is also possible) and coating it.

The binder can be selected from a wide range of insulating resins or organic photoconductive polymers. For example, insulating materials include polyvinyl methylal, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, acrylic resin, polyacrylamide resin, polyamide, cellulose resin,
Examples include urethane resin, epoxy resin, casein, and polyvinyl alcohol. Further, examples of the organic photoconductive polymer include carbazole, polyvinylanthracene, polyvinylpyrene, and the like.

The thickness of the charge generation layer is 0.01 to 15 μm, preferably 0.01 to 15 μm.
．． 05 to 5 μm, and the weight ratio of the charge generation layer to the binder is 10:1 to 1:20.

The solvent used in the paint for the charge generation layer is selected based on the solubility and dispersion stability of the resin and charge transport material used, and examples of organic solvents include alcohols, sulportites, ethers, esters, and aliphatic halogenated solvents. Hydrocarbons or aromatic compounds can be used.

Coating can be carried out using a coating method such as a dip coating method, a spray coating method, a Mayer-Barcoch ink method, or a Fried coating method.

The charge transport layer is formed by dissolving a charge transport material in a film-forming resin. Examples of organic charge transport materials used in the present invention include ζ, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds,
Examples include thiazole compounds and triarylmethane compounds.

These charge transport materials can be used alone or in combination of two or more.

Examples of binders used in the charge transport layer include phenoxy resin, polyacrylamide, polyvinyl butyral, polyarylate, polysulfone, polyamide, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenolic resin, and epoxy. Examples include resins, polyesters, alkyd resins, polycarbonates, polyurethanes, or copolymers containing two or more repeating units of these resins, such as styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, etc. can. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene.

The thickness of the charge transport layer is 5 to 50 μm, preferably 8 to 20 μm.
μm, and the weight ratio of charge transport material and binder is 5:1
-1:5, preferably 3:1-1; 3 degrees. The coating method described above can be used for coating.

Furthermore, dyes, pigments, organic charge transport substances, and the like are generally susceptible to ultraviolet rays, ozone, stains caused by oil, and metals, so a protective layer may be provided as necessary. In order to form an electrostatic latent image on this protective layer, the surface resistivity is 1011.
It is desirable that it is Ω or more.

The protective layer of the photoreceptor is made of polyvinyl butyral, polyester, polycarbonate, acrylic resin, methacrylic resin,
It can be formed by dissolving a resin such as nylon, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer, etc. in a suitable organic solvent on the photosensitive layer and drying it. . At this time, the thickness of the protective layer is generally in the range of 0.05 to 20 μm.

This protective layer may contain an ultraviolet absorber or the like.

The charging member of the present invention can be applied to, for example, an electrophotographic apparatus as shown in FIG. In this apparatus, a primary charging member 6, an image exposure means 7, a developing means 8, a corona charger 9 for transfer charging, a cleaning means 10, and a pre-exposure means 11 are arranged on the circumferential surface of an electrophotographic photoreceptor 2. There is.

The primary charging member 6 placed in contact with the electrophotographic photoreceptor 12 is applied with an external voltage (for example, 200V or more
A pulsating current voltage (which is a superimposition of a DC voltage of V or less and an AC voltage of a peak-to-peak voltage of 4000 V or less) is applied to the electrophotographic photoreceptor 1.
2, the surface of the document is charged, and the image on the document is image-exposed onto the photoreceptor by the image exposure means 7 to form an electrostatic latent image. Next, by attaching the developer in the developing means 8 to the photoreceptor, the electrostatic latent image on the photoreceptor is developed (visualized), and the developer on the photoreceptor is transferred to a corona charger for transfer charging. 9 transfers the developer onto a transfer member 13 such as paper, and a cleaning means 10 collects the developer remaining on the photoreceptor without being transferred to the paper during transfer.

Images can be formed by such an electrophotographic process, but if residual charges remain on the photoreceptor, the photoreceptor is exposed to light by the pre-exposure means 11 to remove the residual charges before primary charging. It is better to eliminate static electricity.

When using the charging member of the present invention for transfer charging, for example,
It can be applied to an electrophotographic apparatus as shown in FIG. In this apparatus, a corona charger 14 for primary charging, an image exposure means 7, a developing means 8, a charging member 15 for transfer charging, a cleaning means 10, and a pre-exposure means 11 are arranged on the circumferential surface of an electrophotographic photoreceptor 120. .

A voltage (for example, a DC voltage of 400 to 100 O
V) can be applied to transfer the developer on the electrophotographic photoreceptor to a transfer member such as paper.

When the charging member of the present invention is used for static electricity removal charging, for example,
It can be applied to an electrophotographic apparatus as shown in FIG. In this apparatus, a corona charger 14 for primary charging, an image exposure means 7, a developing means 8, a corona charger 9 for transfer charging, and a cleaning means 10 are arranged on the circumferential surface of the electrophotographic photoreceptor 2.

A voltage (for example, an AC peak-to-peak voltage of 500 to 500
2000V) can be applied to remove the electric charge on the electrophotographic photoreceptor.

The charging member of the present invention exhibits its characteristics significantly when applied to an electrophotographic photoreceptor having a photosensitive layer containing an organic photoconductor, which easily deteriorates in terms of mechanical strength and chemical stability. can do.

In the present invention, the method for installing the charging member in contact with the photoreceptor is not limited to a specific method.
Any method of movement such as rotation in the same direction as the photoreceptor or in the opposite direction can be used. Furthermore, it is also possible to cause the charging member to function as a developer cleaning device on the photoreceptor.

Regarding the voltage applied to the charging member and the application method in the direct charging of the present invention, it depends on the specifications of each electrophotographic device, but in addition to the method of instantly applying the desired voltage, there are also methods for protecting the photoreceptor. A method can be adopted in which the applied voltage is increased stepwise, or in the case of applying a superimposed alternating current on a direct current, a method can be adopted in which the voltage is applied in the order of direct current → alternating current or alternating direct current.

When the charging member of the present invention is used for primary charging of an electrophotographic device, it is necessary to superimpose a DC voltage and an AC voltage on the electrophotographic photoreceptor in the image output area.

When primary charging is applied only with DC voltage, uniform charging cannot be achieved.

When used for transfer charging, a DC voltage alone or a DC voltage and an AC voltage may be superimposed.

When used for static elimination charging, it is necessary to apply only an alternating current voltage.

Further, in the present invention, processes such as image exposure, development, and cleaning can be performed using any method known in the field of electrostatic photography, and are not limited to a specific type of developer.

The charging member of the present invention can be used not only in copying machines but also in electrophotographic applications such as laser printers, CRT printers, electrophotographic plate-making systems, and facsimile machines having a receiving means for receiving image information from a remote terminal. can.

〔Example] The present invention will be explained below using examples.

Example 1 As a conductive support, 60φ×260 with a wall thickness of 0.5 mm
A mm aluminum cylinder was prepared.

Copolymerized nylon (product name: CM8000, manufactured by Toshi ■) 4
Type 8 nylon (trade name Niratsukamite 50)
03, manufactured by Dainippon Ink ■) and 50 parts of methanol, n
- It was dissolved in 50 parts of butanol and applied on the above support by dip coating to form a 0.6 μm thick undercoat layer.

10 parts of a disazo pigment with the following structural formula, 10 parts of polyvinyl butyral resin (trade name: Esle Tsuku BM2, manufactured by Tsukuki Kagaku ■), 1 part of cyclohexanone
Dispersion was carried out with 20 parts in a sand mill apparatus for 10 hours. 30 parts of methyl ethyl ketone was added to the dispersion and coated on the undercoat layer to form a charge generation layer with a thickness of 0.15 μm.

Polycarbonate Z resin with an average molecular weight of 1,120,000 ff (
(manufactured by Mitsubishi Gas Chemical Co., Ltd.) was prepared and dissolved in 80 parts of monochlorobenzene together with 10 parts of a hydrazone compound having the following structural formula. This was coated on the charge generation layer to form a charge transport layer of 16 μmyJ- to form an electrophotographic photoreceptor N.

manufactured.

Next, conductive carbon 5 was added to 100 parts by weight of chloroprene rubber.
Melt and knead the weight part and form φ8X in the center as a conductive support.
φ20X240mm through a 260mm stainless steel shaft
A conductive elastic layer of a roller-shaped charging member was provided.

The volume resistance of the conductive elastic layer of this charging member is determined at a temperature of 22
"C, when measured in an environment with 60% humidity, it is 3 x 10' Ωcm.

Next, 40 parts by weight of polyvinylhydroquinone +10 is dissolved in 50 parts by weight of 1,2-dichloroethane, and the solution is dip coated onto the conductive elastic layer of the charging member,
After drying, a resin layer having a thickness of 200 μm was provided to produce a roller-shaped charging member.

This charging member is connected to a normal development type copying machine PC as shown in Fig. 3.
-20 (manufactured by Canon) - Installed in place of the next corona charger and rotated in accordance with the electrophotographic photoreceptor. Potential measurements and images of dark potential and bright potential were examined.

The results are shown in Table 1.

Furthermore, the potential characteristics and images obtained when the charging member was attached to a normal development type copying machine under low temperature and low humidity conditions of 15° C. and 10% humidity were similarly investigated and are shown in Table 1.

Example 2 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1.

Next, 50 parts by weight of hydroquinone-phenol-formalin cocondensation resin (phenol/hydroquinone-1/1) (number average molecular weight 50,000) was dissolved in 50 parts by weight of 1,2-dichloroethane, and the conductive elasticity of the charging member was dissolved. A resin layer having a thickness of 200 μm after drying was provided on the layer by dip coating to produce a roller-shaped charging member.

The dirt was evaluated in the same manner as in Example 1 and is shown in Table 1.

Comparative Example 1 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1.

Next, 5 parts by weight of 6-66-10-12 nylon was dissolved in 90 parts by weight of methanol, and the solution was dip coated onto the conductive elastic layer of the charging member, and after drying, a resin layer with a thickness of 200 pm was formed. A roller-shaped (1) heavy duty member was manufactured.

This was evaluated in the same manner as the example construction and is shown in Table 1.

Comparative Example 2 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1.

Next, 5 parts by weight of methoxymethylated nylon 6 (methoxymethylation rate 25%) was dissolved in 90 parts by weight of methanol, and the solution was dip-coated onto the conductive elastic layer of the charging member to give a film thickness of 200 μm after drying. A resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 1 and is shown in Table 1.

Comparative Example 3 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1.

Next, to the polyester polyol, Tuboran 121, 4 parts by weight of Nippon Polyurethane (manufactured by Nippon Polyurethane) and tolylene diisocyanate were added.
Dissolve 1.1 parts by weight in 90 iii parts of n-butanol and apply by dip coating on the conductive elastic layer of the charging member,
After drying, a resin layer having a thickness of 200 μm was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 1 and is shown in Table 1.

Comparative Example 4 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1.

Next, 5 parts by weight of silicone RTV rubber was dissolved in 90 parts by weight of toluene, and the solution was applied by dip coating onto the conductive elastic layer of the charging member, and after drying, a resin layer with a film thickness of 200 μm was provided, and a roller-shaped charging member was manufactured.

This was evaluated in the same manner as in Example 1 and is shown in Table 1.

As can be seen by comparing Examples 1 and 2 with Comparative Examples 1 and 2, the present invention can prevent image defects such as wavy fog caused by hardening of the resin layer at low temperature and low humidity.

Further, as can be seen by comparing Examples 1 and 2 with Comparative Examples 3 and 4, it is possible to prevent the charging member from fusing with the photoreceptor and to suppress the occurrence of horizontal streak images.

Example 3 Below, the characteristics as a transfer charger were investigated.

A photoreceptor was produced in the same manner as in Example 1.

Next, conductive carbon 5 was added to 100 parts by weight of chloroprene rubber.
The weight parts were melt-kneaded, passed through a stainless steel shaft of 8 mm x 260 mm in the center, and molded to a size of 30 mm x 240 mm, and a conductive elastic layer of a roller shape transfer charging member was provided.

The volume resistance for transfer charging is 4×10′Ωcm when measured in an environment with a temperature of 22°C and a humidity of 60%.

Next, 20 parts by weight of polyvinylhydroquinone +10 is dissolved in 50 parts by weight of 1,2-dichloroethane, and the solution is dip coated on the conductive elastic layer of the transfer charging member, and after drying, a resin layer with a thickness of 100 μm is provided. A roller shape transfer charging member was manufactured.

This transfer charging member was installed in place of the transfer corona charger of a normal development type copying machine I) C20 (Canon type), and a direct current of -500 cm was applied for transfer charging, and the state of the image and the transfer charging member was examined. .

The results are shown in Table 2.

Further, the image and the state of the transfer charging member when the transfer charging member was installed in a normal development type copying machine at a low temperature and low humidity condition of 15''C and 10% humidity were investigated and are shown in Table 2.

Example 4 In the same manner as in Example 3, a conductive elastic layer of a transfer charging member was prepared.

Next, 25 parts by weight of hydroquinone-phenol-pormarine cocondensation resin (phenol/hydroquinone-1/1) (number average molecular weight 50,000) was dissolved in 50 parts by weight of 1,2-dichloroethane, and the conductivity of the transfer charging member was dissolved. A resin layer having a thickness of 100 pm after drying was provided on the elastic layer by dip coating to produce a roller shape transfer charging member.

This was evaluated in the same manner as in Example 3 and is shown in Table 2.

Comparative Example 5 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 3.

Next, 5 parts by weight of 6-66-10-12 nylon was dissolved in 90 parts by weight of methanol, and the solution was dip coated onto the conductive elastic layer of the transfer charging member, and after drying, a resin layer with a thickness of 100 μm was provided. , a roller shape transfer charging member was manufactured.

This was evaluated in the same manner as in Example 3 and is shown in Table 2.

Comparative Example 6 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 3.

Next, 5 parts by weight of methoxymethylated nylon 6 (methoxymethylation rate 25%) was dissolved in 90 parts by weight of methanol, and the solution was dip coated onto the conductive elastic layer of the transfer charging member, and after drying, the film thickness was 100 μM. A roller shape transfer charging member was manufactured by providing a resin layer of.

This was evaluated in the same manner as in Example 3 and is shown in Table 2.

Comparative Example 7 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 3.

Next, 4 parts by weight of Tuboran 121 (Japan Polyurethanes) and 1 part by weight of tolylene diisocyanate were dissolved in 90 parts by weight of n-butanol in polyester polyol, and the solution was dip coated onto the conductive elastic layer of the transfer charging member. A resin layer having a thickness of 100 μm after drying was provided to produce a roller shape transfer charging member.

This was evaluated in the same manner as in Example 3 and is shown in Table 2.

Comparative Example 8 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 3.

Next, the silicone RTV rubber 5-fold foot part was dissolved in 90 parts by weight of toluene and dip coated on the conductive elastic layer of the transfer charging member, and after drying, a resin layer with a film thickness of 100μ was provided, and the roller shape was applied. A transfer charging member was manufactured.

This was evaluated in the same manner as in Example 3 and is shown in Table 2.

As can be seen from Example 3.4 and Comparative Example 5.6, the present invention can maintain high image quality without causing a decrease in density or wavy fog even under low temperature and low humidity conditions.

Furthermore, as can be seen from Examples 3 and 4 and Comparative Examples 7 and 8, in the present invention, the transfer charging member does not fuse with the photoreceptor, nor does it fuse with the toner, so no defects occur in the photoreceptor or the charging member. Can be used.

Example 5 Below, we investigated its characteristics as a static eliminator.

A photoreceptor was produced in the same manner as in Example 1.

Next, conductive carbon 5 was added to 100 parts by weight of chloroprene rubber.
Melt and knead the weight part and place it on a 2mm x 260mm stainless steel plate with a free length of 10mm x 240mm as shown in Figure 3.
The conductive elastic layer of the plate shape transfer charging member was provided. The volume resistivity of this static eliminator charging member is 4X10 when measured in an environment with a temperature of 22°C and a humidity of 60%.
' Ωcm.

Next, 20 parts by weight of polyvinylhydroquinone +10 was dissolved in 50 parts by weight of 1,2-dichloroethane, and the solution was applied by dip coating onto the conductive elastic layer of the static elimination/charging member, and after drying, a resin layer with a film thickness of 100 μm was provided. , a plate-shaped static elimination/charging member was manufactured.

This static eliminator charging member was installed in place of the pre-exposure static eliminator of the normal development type copying machine PC20 (manufactured by Canon), and an AC peak-to-peak voltage of 1000 V was applied for static neutralization, and the residual potential after static elimination, the image, and the static neutralization charging member We examined the state of

The results are shown in Table 3.

Furthermore, the image and the state of the static eliminating charging member when the static eliminating charging member was attached to a normal development type copying machine under a low temperature and low humidity condition of 15° C. and 10% humidity were investigated and are shown in Table 3.

Example 6 In the same manner as in Example 5, a conductive elastic layer of a static elimination/charging member was prepared.

Next, 50 parts by weight of hydroquinone-phenol-formalin cocondensation resin (phenol/hydroquinone-1/1) (number average molecular weight 50,000) was dissolved in 50 parts by weight of 1,2-dichloroethane to conduct the defrosting and charging member. A resin layer having a thickness of 100 μm was provided on the elastic layer by dip coating, and after drying, a blade-shaped static elimination/charging member was manufactured.

This was evaluated in the same manner as in Example 5 and is shown in Table 3.

Comparative Example 9 In the same manner as in Example 5, a conductive elastic layer of a static elimination/charging member was prepared.

The static elimination/charging member was used as it was without providing a resin layer.

This was evaluated in the same manner as in Example 5 and is shown in Table 3.

Comparative Example 10 In the same manner as in Example 5, a conductive elastic layer of a static elimination/charging member was prepared.

Next, 10 parts by weight of methoxymethylated nylon-6 (methoxymethylation rate 25%) was dissolved in 90 parts by weight of methanol, and the solution was dip-coated onto the conductive elastic layer of the static eliminating charge member, and after drying, the film thickness was A resin layer of 100 μm was provided to produce a blade-shaped static elimination/charging member.

This was evaluated in the same manner as in Example 5 and is shown in Table 3.

Comparative Example 11 In the same manner as in Example 5, a conductive elastic layer of a static elimination/charging member was prepared.

Next, polyester polyol, Tuboran 121, Nippon Polyurethane Co., Ltd.) 8-fold part, and 2 parts by weight of toluylene diisocyanate are dissolved in 90 parts by weight of n-butanol, and the solution is dip-coated onto the conductive elastic layer of the static elimination/charging member. After drying, a resin layer with a thickness of 100 μm was provided to produce a blade-shaped static elimination/charging member.

This was evaluated in the same manner as in Example 5 and is shown in Table 3.

Comparative Example 12 Static electricity was removed by pre-exposure without using the charging member for charge removal of the present invention, and this was evaluated in the same manner as in Example 5, and the results are shown in Table 3.

As can be seen by comparing Examples 5 and 6 with Comparative Examples 9 and 11, the present invention prevents the charging member and the photoreceptor from being fused together, thereby preventing the occurrence of image defects in the form of horizontal stripes.

Further, as can be seen by comparing Examples 5 and 6 with Comparative Example 10, stable static elimination performance was exhibited even under low temperature and low humidity conditions, and the material of the present invention can suppress image defects.

In Comparative Example 12, the static elimination performance of the conventional pre-exposure type static elimination was low, and residual potential was likely to remain at low temperature and low humidity, causing soil burr defects.

(Effects of the Invention) As is clear from the above results, by using the charging member of the present invention, the adhesion to the electrophotographic photoreceptor is low;
Since it is also flexible, it produces high-quality images and produces less toner stains. In particular, stable potential characteristics and image characteristics can be obtained even under low temperature and low humidity conditions.

[Brief explanation of the drawing]

Figures 1 and 2 are sectional views in the central axis direction of a roller-shaped charging member, Figure 3 is a sectional view of a blade-shaped charging member, and Figures 4, 5, and 6 are cross-sectional views of an electrophotographic device. It is a diagram. 1a... Conductive support, 1b... Conductive sheet metal, 2.
... Conductive elastic layer, 3... Resin layer, 4... Protective layer,
5... Resin powder, 6... Charging member, 7... Image exposure means, 8 Development means, 9... Corona charger for transfer charging, 10... Cleaning means, 11... Pre-exposure means, 12... Electrophotographic photoreceptor, Step 4... Corona charger for secondary charging, 15... Charging member for transfer charging, 16...
・Charging member for static electricity removal. Figure: Agent, Patent Attorney, Minoru Yamashita, Children:

Claims (4)

[Claims] (1) A charging member having a conductive elastic layer on a conductive support, the charging member having a resin layer containing a hydroquinone derivative resin on the conductive elastic layer. (2) The charging member according to claim 1, wherein the charging member contacts an electrophotographic photoreceptor to charge the photoreceptor. (3) The charging member according to claim 1, wherein the electrophotographic photoreceptor is primarily charged by superimposing a DC voltage and an AC voltage as applied voltages. (4) The charging member according to claim 1, wherein the developer is transferred from the electrophotographic photoreceptor to the transfer member by using a DC voltage as the applied voltage or by superimposing a DC voltage and an AC voltage. (5) The charging member according to claim 1, wherein the electrophotographic photoreceptor is neutralized using an alternating current voltage as the applied voltage.