JP2700011B2 - Charging member - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a charging member, and more particularly to a charging member used for temporary charging, transfer charging, and charge removal in electrophotography.

[Problems to be Solved by the Related Art and the Invention] In the charging process in the electrophotographic process using the electrophotographic photosensitive member, a high voltage (DC)
(5-8 kV) is applied and charging is performed by the corona generated. However, in this method, ozone and NO _x
There is a problem that the surface of the photoreceptor is deteriorated by corona products such as the above, causing image blurring and deterioration, and contamination of the wire affects the image quality, resulting in image white spots and black stripes.
On the other hand, the electric current flowing toward the photoreceptor was only 5 to 30% of the electric current, and most of the electric current flowed to the shield plate and was ineffective as a charging means.

In order to compensate for such disadvantages, direct charging methods have been studied and many proposals have been made (JP-A-57-178267, JP-A-56-104351, JP-A-58-40566, JP-A-58-40566). -139156, JP-A-58-150975, etc.). However, even if the photoconductor is charged by the contact charging method as described above, each portion of the photoconductor surface is not uniformly charged,
Spot-like uneven charging occurs. For example, in the reversal development method, even if a process of light image exposure or less is applied to the photoreceptor in the spot-like uneven charging state, the output image becomes a black spot image on the spot corresponding to the spot-like charging unevenness, and the spot development in the normal development method. The image becomes a spot-like white image with respect to the unevenness, and a high-quality image cannot be obtained.

Further, the direct charging method has no market record in spite of many proposals. The reasons for this include the uniformity of charging and the occurrence of discharge breakdown of the photoconductor due to the direct application of voltage. One breakdown point of the discharge breakdown, for example, in the case of a cylindrical photosensitive member, has a drawback that the charge in the entire axial direction flows to the breakdown point and is not charged.

Accordingly, it is an object of the present invention to provide a charging member that has stable potential characteristics and does not cause image defects such as blurred images, missing images, and black stripes.

[Means for Solving the Problems] That is, the present invention provides a charging member having a conductive elastic layer on a conductive support, wherein the conductive elastic layer has a resin layer containing a polyamide and an isocyanate compound on the conductive elastic layer. A charging member characterized in that:

 Hereinafter, the present invention will be described in more detail.

In the charging member of the present invention, as shown in FIG. 1, a conductive elastic layer 2 is provided on a conductive support 1a, and a resin layer 3 containing a polyamide and an isocyanate compound is further provided on the elastic layer 2. The basic form is to have a three-layer structure.

The polyamide contained in the resin layer 3 includes nylon 6, Ninelon 6-66-10, and nylon 6-66-10-12.
And alkoxymethylated nylon such as methoxymethylated nylon and ethoxymethylated nylon.

As the isocyanate compound used for the resin layer, an isocyanate compound such as toluylene diisocyanate and hexamethylene diisocyanate, or a blocked isocyanate compound is used.

 Hereinafter, specific examples of the isocyanate compound will be described.

Further, other binder resins and additives may be added to the resin layer.

Examples of the binder resin which may be added to the resin layer include acrylic resins such as polymethyl methacrylate and polybutyl methacrylate, polyvinyl butyral, polyvinyl acetal, polyarylate, polycarbonate, polyester, phenoxy resin, polyvinyl acetate, polyvinyl pyrazine, and cellulose resin. And so on.

As the charging member, it is necessary that the electric resistance is not affected by changes in the external environment, particularly changes in the humidity in the atmosphere. For example, when the resin layer is made of nylon only, it is particularly low temperature and low humidity (for example, 15 ° C.). , 10% RH), the volume resistance is increased by three digits.

On the other hand, in the present invention, by including the polyamide and the isocyanate compound in the resin layer, it is possible to obtain a stable charging member with little change in volume resistance.
Further, since the isocyanate compound binds to the polyamide, when it is used for a charging member, it does not migrate to the contacting photoconductor like a low-molecular substance, and does not contaminate the photoconductor. Furthermore, in the present invention, since the polyamide is cured, even if the polyamide is in contact with the photoconductor for a long time, the compatibilization phenomenon with the photoconductor binder does not occur, and the polyamide does not adhere to the photoconductor.

The thickness of the resin layer is preferably in the range of 5 to 500 μm, particularly preferably in the range of 20 to 200 μm.

The volume resistivity of the resin layer is preferably in the range of 10 ⁶ to 10 ¹² Ω · cm. Further, as disclosed in Japanese Patent Application No. 62-230334, the volume resistivity of the resin layer is preferably larger than the volume resistivity of the lower conductive elastic layer in contact with the resin layer. 10 ⁰ to 10 ¹¹ Omega is a volume resistivity of the elastic layer · cm, preferably in the range of particularly ^{10 2} ~10 10 Ω · cm. Aluminum, iron,
Metals such as copper, conductive polymers such as polyacetylene, polypyrrole, and polythiophene; rubber and thermoplastic elastomers in which carbon and metal are dispersed and conductively treated; and metal and other conductive substances on the surface of rubber and thermoplastic elastomers Can be used. Further, the elastic layer 2 may have a multilayer structure in which functions are separated as necessary.
Iron, copper, stainless steel, or the like can be used as the conductive support 1a.

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 may be mixed with conductive particles therein to control conductivity and insoluble resin powder 5 to control 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 a conductive sheet metal 1b, and a resin layer 3
Can be provided.

 Further, a protective layer may be provided.

The shape of the charging member may be any of a roller shape and a blade shape, but a roller shape is preferable in terms of uniform charging.

The electrophotographic photoreceptor is based on a configuration in which a photosensitive layer is provided on a conductive support. As the conductive support, a support having conductivity itself, for example, aluminum, an aluminum alloy, stainless steel, chromium, titanium, or the like can be used.In addition, aluminum, an aluminum alloy, an indium oxide-tin oxide alloy, or the like can be used. A conductive support having a layer formed by vacuum deposition, plastic, a support in which conductive particles (eg, carbon black, tin oxide particles, etc.) are impregnated with a suitable binder into plastic or paper, and a conductive binder. Plastic or the like can be used.

An undercoat layer having a barrier function and an adhesive function may 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, polyurethane, gelatin, aluminum oxide, or the like. The thickness of the undercoat layer is 5 μm or less, preferably 0.5 to 3 μm.
m is appropriate. The undercoat layer preferably has a resistivity of 10 ⁷ Ω · cm or more in order to exhibit its function.

The photosensitive layer is formed, for example, by coating a photoconductor such as an organic photoconductor, amorphous silicon, or selenium with a binder as required, and applying or forming the coating or vacuum deposition.
When an organic photoconductor is used, a photosensitive layer composed of a combination of a charge generation layer that generates charge carriers upon exposure and a charge transport layer capable of transporting the generated charge carriers can also be used effectively.

The charge generation layer is formed by depositing one or more kinds of charge generation materials such as azo pigments, quinone pigments, quinone anine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, and quinacdrine pigments, or It can be formed by dispersing together with a binder (even without a binder) and coating.

The binder can be selected from a wide range of insulating resins or organic photoconductive polymers. For example, as the insulating resin, polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, acrylic resin, polyacrylamide resin, polyamide, cellulose resin, urethane resin, epoxy resin, Casein, polyvinyl alcohol and the like can be mentioned. Examples of the organic photoconductive polymer include carbazole, polyvinyl anthracene, and polyvinyl pyrene.

The thickness of the charge generation layer is 0.01 to 15 μm, preferably 0.05 to
5 μm, and the weight ratio between the charge generation layer and the binder is 10: 1 to
1:20.

The solvent used for the coating for the charge generation layer is selected from the solubility and dispersion stability of the resin and the charge transporting material used. As the organic solvent, alcohols, sulfoxides, ethers, esters, and aliphatic halides are used. Hydrocarbons or aromatic compounds can be used.

Coating can be performed using a coating method such as a dip coating method, a spray coating method, a Meyer bar coating method, and a blade coating method.

The charge transport layer is formed by dissolving a charge transport material in a film-forming resin. Examples of the organic charge transporting material used in the present invention include hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds. These charge transport materials can be used alone or in combination of two or more.

Examples of the binder used for 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, epoxy Resin, polyester, alkyd resin, polycarbonate,
Polyurethane or a copolymer containing two or more of the repeating units of these resins, such as a styrene-butadiene copolymer, a styrene-acrylonitrile copolymer, and a styrene-maleic acid copolymer can be used. Further, it can 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.
m, and the weight ratio of the charge transport material to the binder is 5: 1 to 1:
5, preferably about 3: 1 to 1: 3. The coating can be performed by the coating method as described above.

Furthermore, since dyes, pigments, organic charge transporting substances, and the like are generally vulnerable to contamination by ultraviolet rays, ozone, oil, and the like, metals, and the like, a protective layer may be provided as necessary. To form an electrostatic latent image on this protective layer, the surface resistivity must be 10 ¹¹ Ω
It is desirable that this is the case.

The protective layer of the photoreceptor is preferably a resin such as polyvinyl butyral, polyester, polycarbonate, acrylic resin, methacrylic resin, nylon, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer. A solution dissolved by an organic solvent can be formed on the photosensitive layer by coating and drying. At this time, the thickness of the protective layer is generally in the range of 0.05 to 20 μm. The 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 unit 7, a developing unit 8, a corona charger 9 for transfer charging, a cleaning unit 10, and a pre-exposure unit 11 are arranged on a peripheral surface of an electrophotographic photosensitive member 12. .

A voltage (for example, a pulsating voltage in which a DC voltage of 200 V or more and 2000 V or less and an AC voltage of 4000 V or less between peaks are superimposed) is externally applied to the primary charging member 6 which is arranged in contact with the electrophotographic photosensitive member 12. Then, the surface of the electrophotographic photosensitive member 12 is charged, and the image on the original is image-exposed to the photosensitive member by the image exposure means 7 to form an electrostatic latent image. Next, an electrostatic latent image on the photoconductor is developed (visualized) by attaching the developer in the developing unit 8 to the photoconductor, and the developer on the photoconductor is transferred to paper by the transfer charging unit 9. The developer remaining on the photosensitive member without being transferred onto the paper at the time of transfer by the cleaning unit 10 is collected by the transfer member 13.

An image can be formed by such an electrophotographic process, but if residual charges remain on the photoconductor, light is applied to the photoconductor by the pre-exposure means 11 before primary charging to remove the residual charges. You had better.

When the charging member of the present invention is used for transfer charging, it can be applied to, for example, an electrophotographic apparatus as shown in FIG. In this apparatus, a primary charging corona charger 14, an image exposure means 7, a developing means 8, a transfer charging member 15, a cleaning means 10, and a pre-exposure means 11 are arranged on the peripheral surface of an electrophotographic photosensitive member 12. I have.

A voltage (for example, a DC voltage of 400 to 1000 V) is applied to the transfer charging member 15 that is arranged in contact with the electrophotographic photosensitive member 12 to transfer the developer on the electrophotographic photosensitive member to a transfer member such as paper. Can be.

When the charging member of the present invention is used for static elimination charging, it can be applied to, for example, an electrophotographic apparatus as shown in FIG. In this apparatus, a primary charging corona charger 14, an image exposure unit 17, a developing unit 8, a transfer charging corona charger 9, and a cleaning unit 10 are arranged on a peripheral surface of an electrophotographic photosensitive member 12.

A voltage (for example, an AC peak-to-peak voltage of 500 to 2000)
V) can be applied to eliminate charges on the electrophotographic photosensitive member.

The charging member of the present invention exerts its characteristics remarkably by being applied to an electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductor, which is susceptible to deterioration in mechanical strength and chemical stability. can do.

The charging member to be brought into contact with the photoreceptor in the present invention is not limited to a specific method, and the charging member may be a fixed type or a moving type such as rotating in the same direction or the opposite direction to the photoreceptor. it can. Further, it is possible for the charging member to function as a developer cleaning device on the photosensitive member.

Applied voltage to the charging member in the direct charging of the present invention,
Regarding the application method, it depends on the specifications of each electrophotographic apparatus, but in addition to the method of applying the desired voltage instantaneously, the method of gradually increasing the applied voltage for the purpose of protecting the photoreceptor, the method of applying DC to AC Can be applied in the order of DC AC or AC DC in the case of superimposing.

In the present invention, processes such as image exposure, development, and cleaning can employ any method known in the field of electrostatography, and are not limited to a specific type such as a type of developer. The charging member of the present invention can be used not only in copying machines but also in electrophotographic application fields such as laser printers, CRT printers, and electrophotographic plate making systems.

EXAMPLES Hereinafter, the present invention will be described with reference to Examples.

Example 1 As a conductive support, an aluminum cylinder having a thickness of 0.5 and a diameter of 60 mm × 260 mm was prepared.

Copolymer nylon (trade name: CM8000, manufactured by Toray Industries, Inc.) 4
Part and type 8 nylon (trade name: Lacamide 500
3, Dainippon Ink Co., Ltd.) 4 parts methanol 50 parts, n
-Dissolved in 50 parts of butanol and dip-coated on the support to form a 0.6 μm thick undercoat layer.

10 parts of disazo pigment of the following structural formula, And polyvinyl butyral resin (trade name: Eslec BM
2, Sekisui Chemical Co., Ltd.) and 10 parts of cyclohexanone were dispersed in a sand mill for 10 hours. Add 30 parts of methyl ethyl ketone to the dispersion and apply on the undercoat layer,
A charge generation layer having a thickness of 0.15 μm was formed.

Prepare 10 parts of polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a weight average molecular weight of 120,000, and prepare a hydrazone compound having the following structural formula. It was dissolved in 80 parts of monochlorobenzene together with 10 parts. This was applied on the charge generation layer to form a charge transport layer having a thickness of 16 μm, thereby producing an electrophotographic photosensitive member No. 1.

Next, conductive carbon 5 was added to 100 parts by weight of chloroprene rubber.
Melt and knead parts by weight, φ8 ×
It was formed into a diameter of 20 × 240 mm through a stainless steel shaft of 260 mm, and a conductive elastic layer (hereinafter referred to as a base layer) of a roller-shaped charging member was provided.

The volume resistance of the charging member base layer was adjusted to a temperature of 22 ° C and a humidity of 60
%, It is 3 × 10 ⁴ Ω · cm.

Next, 8 parts by weight of the nylon 6-66-10 copolymer and 2 parts by weight of the isocyanate compound (4) were dissolved in 90 parts by weight of methanol, and the resultant was applied by dip coating on the charging member base layer. A 200 μm resin layer was provided to produce a roller-shaped charging member. A resin layer was similarly provided on the aluminum sheet, and the volume resistance was measured.

As shown in FIG. 3, this charging member is used in a regular development type copying machine.
Installed in place of PC-20 (Canon) primary corona charger, primary charging is performed by superimposing DC voltage -750V and AC peak-to-peak voltage 1500V, measuring potential of dark potential and bright potential and 1mm on photoconductor The image when the pinhole was opened was examined.

 The results are shown in Table 1.

Furthermore, the volume resistance of the resin layer of the charging member in a low-temperature and low-humidity state at a temperature of 15 ° C. and a humidity of 10%, the potential characteristics when the charging member is attached to a positive development type copier, and an image are similarly examined. 1 is shown.

Example 2 A charging member base layer was prepared in the same manner as in Example 1.

Next, 8 parts by weight of nylon 6-66-10-128 and 2 parts by weight of the isocyanate compound (5) were dissolved in 90 parts by weight of methanol, and dip-coated on the charging member base layer.
A 0 μm resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 A charging member base layer was prepared in the same manner as in Example 1.

Next, 8 parts by weight of methoxymethylated nylon-6 (methoxymethylation rate: 20%, the same applies hereinafter) and 2 parts by weight of the isocyanate compound (3) are dissolved in 90 parts by weight of methanol and dip-coated on the charging member base layer. After drying, a resin layer having a thickness of 200 μm was provided after drying to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 4 A charging member base layer was prepared in the same manner as in Example 1.

Next, 77 parts by weight of methoxymethylated nylon-67 and 3 parts by weight of the isocyanate compound (2) are dissolved in 90 parts by weight of methanol, dip-coated on the charging member base layer, and dried to form 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 the results are shown in Table 1.

Comparative Example 1 The roller-shaped charging member base layer of Example 1 was directly attached to a copying machine PC-20 (manufactured by Canon) instead of the primary corona charger.

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 A charging member base layer was prepared in the same manner as in Example 1.

Next, conductive carbon was added to 10 parts by weight of chloroprene rubber.
2 parts by weight and 90 parts by weight of methyl ethyl ketone were added and dispersed by a ball mill.

This dispersion was applied onto the charging member base layer by dip coating, and after drying, a 200 μm-thick resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 3 A charging member base layer was prepared in the same manner as in Example 1.

Next, 90 parts by weight of dimethylformamide was dissolved in 10 parts by weight of nylon-66, dip coating was performed on the charging member base layer, and a resin layer having a thickness of 200 μm after drying was provided to produce a roller-shaped charging member. .

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 4 A charging member base layer was prepared in the same manner as in Example 1.

Next, 5 parts by weight of non-conductive titanium oxide particles, 5 parts by weight of polybutyl methacrylate, and 90 parts by weight of methanol were dispersed in a ball mill, dip-coated on the charging member base layer, and dried to form a 200 μm-thick resin layer. And a roller-shaped charging member was manufactured.

This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

As can be seen by comparing Examples 1, 2, 3, and 4 with Comparative Example 1,
By keeping the volume resistance of the resin layer at 10 ⁶ Ωcm or more,
Leakage due to pinholes is hindered, and horizontal streaking is prevented. Further, even if the volume resistance of the resin layer is about the same, by the resin film composed of the polyamide and the isocyanate compound of the present invention, the charge is stable and the image density is kept appropriate,
The occurrence of image defects is suppressed.

In Comparative Example 3 using a conventionally known material and Comparative Example 4 using titanium oxide particles as they are, charging is not sufficiently performed, the image density is low, and the image result is poor.

Further, Examples 1, 2, 3, and 4 show more stable charging characteristics than a resin film composed of a polyamide and an isocyanate compound even under low temperature and low humidity, and the image density is appropriate and no image defects occur.

Example 5 A photoconductor was produced in the same manner as in Example 1.

Next, 100 parts by weight of chloroprene rubber and 5 parts by weight of conductive carbon are melted and kneaded, and a stainless steel shaft of φ8 × 260 mm is formed at the center to form φ30 × 240 mm to form a conductive elastic layer of a roller-shaped charging member. Provided.

The volume resistance of the charging member is 4 × 10 ⁴ Ω · cm when measured in an environment at a temperature of 22 ° C. and a humidity of 60%.

Next, 7 parts by weight of the nylon 6-66-10 copolymer and 3 parts by weight of the isocyanate compound (3) are dissolved in 90 parts by weight of methanol, and dip-coated on the conductive elastic layer of the charging member. After drying, a resin layer having a thickness of 100 μm was provided to produce a roller-shaped charging member. A resin layer was similarly provided on the aluminum sheet, and the volume resistance was measured.

Copying machine PC-
20 (manufactured by Canon) Replaces the primary corona charger. Primary charging is performed with a DC voltage of -750 V and an AC peak-to-peak voltage of 15 V.
00V was superimposed to examine the state of the image and the charging member.

 The results are shown in Table 2.

In addition, the volume resistance of the resin layer of the charging member in a low-temperature and low-humidity state at a temperature of 15 ° C and a humidity of 10%, and the state of the image and the charging member when the charging member is mounted on a reversal developing type copying machine are examined. 2 is shown.

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

Next, 7 parts by weight of nylon 6-66-10-127 and 3 parts by weight of the isocyanate compound (4) are dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the charging member, and dried. A 100 μm-thick resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Example 7 In the same manner as in Example 5, a conductive elastic layer of a charging member was prepared.

Next, 8 parts by weight of methoxymethylated nylon-6 (methoxymethylation rate 20%) and isocyanate compound (6)
Dissolve 2 parts by weight in 90 parts by weight of methanol, dip-coat on the conductive elastic layer of the charging member, and dry to a thickness of 100 μm.
m, and a roller-shaped charging member was manufactured.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Example 8 In the same manner as in Example 5, a conductive elastic layer of a charging member was prepared.

Next, 77 parts by weight of methoxymethylated nylon-67 and 3 parts by weight of the isocyanate compound (4) are dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the charging member, and dried. A 100 μm resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Comparative Example 5 Instead of the primary corona charger of the copying machine PC-20 (manufactured by Canon Inc.), the roller-shaped charging member base layer of Example 5 was modified as it was to the reversal development system.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Comparative Example 6 A charging member base layer was prepared in the same manner as in Example 5.

Next, conductive carbon was added to 10 parts by weight of chloroprene rubber.
2 parts by weight and 90 parts by weight of methyl ethyl ketone were added and dispersed by a ball mill.

This dispersion was applied onto the charging member base layer by dip coating, and after drying, a 200 μm-thick resin layer was provided to produce a roller-shaped charging member.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Comparative Example 7 A charging member base layer was prepared in the same manner as in Example 5.

Next, 90 parts by weight of dimethylformamide was dissolved in 10 parts by weight of nylon-66, dip coating was performed on the charging member base layer, and a resin layer having a thickness of 200 μm after drying was provided to produce a roller-shaped charging member. .

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Comparative Example 8 A charging member base layer was prepared in the same manner as in Example 5.

Next, 5 parts by weight of non-conductive titanium oxide particles, 5 parts by weight of polybutyl methacrylate, and 90 parts by weight of methanol were dispersed in a ball mill, dip-coated on the charging member base layer, and dried to form a 200 μm-thick resin layer. And a roller-shaped charging member was manufactured.

This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

As can be seen by comparing Examples 5, 6, 7, 8 and Comparative Examples 5, 6, 7, 8 in the present invention, a reduction in image density at normal temperature and normal humidity, low temperature and low humidity, image defects, and prevention of leaks due to pinholes are prevented. it can.

Example 9 Hereinafter, characteristics as a transfer charger were examined.

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

Next, 100 parts by weight of chloroprene rubber and 5 parts by weight of conductive carbon are melted and kneaded, and a stainless steel shaft of φ8 × 260 mm is formed at the center to form φ30 × 240 mm to form a conductive elastic layer of a roller-shaped charging member. Provided.

The volume resistance of the transfer charging member is set at a temperature of 22 ° C. and a humidity of 60
It is 4 × 10 ⁴ Ω · cm when measured in a% environment.

Next, 7 parts by weight of the nylon 6-66-10 copolymer and 3 parts by weight of the isocyanate compound (3) are dissolved in 90 parts by weight of methanol, and dip-coated on the conductive elastic layer of the transfer charging member. After drying, a resin layer having a thickness of 100 μm was provided to produce a roller-shaped transfer charging member. A resin layer was similarly provided on the aluminum sheet, and the volume resistance was measured.

This transfer charging member was attached in place of the transfer corona charger of the positive development type copying machine PC-20 (manufactured by Canon), and DC-500 V was applied for transfer charging, and the state of the image and the transfer charging member was examined.

 The results are shown in Table 3.

Furthermore, the volume resistance of the resin layer of the transfer charging member in a low-temperature and low-humidity state of a temperature of 15 ° C. and a humidity of 10%, and the image and the state of the transfer charging member when the transfer charging member is attached to a positive development type copying machine. The results are shown in Table 3.

Example 10 In the same manner as in Example 9, a conductive elastic layer of a transfer charging member was prepared.

Next, 7 parts by weight of nylon 6-66-10-127 and 3 parts by weight of the isocyanate compound (4) are dissolved in 90 parts by weight of methanol and dip-coated on the conductive elastic layer of the transfer charging member. After drying, a resin layer having a thickness of 100 μm was provided to produce a roller-shaped transfer charging member.

 This was evaluated in the same manner as in Example 9 and shown in Table 3.

Example 11 In the same manner as in Example 9, a conductive elastic layer of a transfer charging member was prepared.

Next, 8 parts by weight of methoxymethylated nylon-6 (methoxymethylation rate 20%) and isocyanate compound (6)
2 parts by weight, dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the transfer charging member, and dried to a film thickness of 10 parts.
A 0 μm resin layer was provided to produce a roller-shaped transfer charging member.

 This was evaluated in the same manner as in Example 9 and shown in Table 3.

Example 12 In the same manner as in Example 9, a conductive elastic layer of a transfer charging member was prepared.

Next, 77 parts by weight of methoxymethylated nylon-67 and 3 parts by weight of the isocyanate compound (4) are dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the transfer charging member, and dried. A resin layer having a thickness of 100 μm was provided, and a roller-shaped transfer charging member was manufactured.

 This was evaluated in the same manner as in Example 9 and shown in Table 2.

Comparative Example 9 The roller-shaped charging member base layer of Example 9 was directly attached to the copy base PC-20 (manufactured by Canon) instead of the corona charger for transfer charging as shown in FIG.

This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 10 A charging member base layer was prepared in the same manner as in Example 9.

Next, conductive carbon was added to 10 parts by weight of chloroprene rubber.
2 parts by weight and 90 parts by weight of methyl ethyl ketone were added and dispersed by a ball mill.

This dispersion was applied onto the charging member base layer by dip coating, and after drying, a 200 μm-thick resin layer was provided to produce a roller-shaped transfer charging member.

This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 11 A charging member base layer was prepared in the same manner as in Example 9.

Next, dissolve 90 parts by weight of dimethylformamide in 10 parts by weight of nylon-66, dip-coat on the charging member base layer, provide a 200 μm-thick resin layer after drying, and manufacture a roller-shaped transfer charging member. did.

This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 12 A charging member base layer was prepared in the same manner as in Example 9.

Next, 5 parts by weight of non-conductive titanium oxide particles, 5 parts by weight of polybutyl methacrylate, and 90 parts by weight of methanol were dispersed in a ball mill, dip-coated on the charging member base layer, and dried to form a 200 μm-thick resin layer. And a roller-shaped transfer charging member was manufactured.

This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

As can be seen by comparing Examples 9, 10, 11, 12 and Comparative Examples 9, 10, 11, 12, the present invention prevents image density reduction at normal temperature and normal humidity, low temperature and low humidity, image defects, and leakage due to pinholes. it can.

Example 13 Hereinafter, characteristics as a static eliminator were examined.

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

Next, 100 parts by weight of chloroprene rubber and 5 parts by weight of conductive carbon are melted and kneaded, and molded on a 2 mm × 260 mm stainless steel plate at the center so as to have a free length of 10 mm × 240 mm as shown in FIG. The conductive elastic layer of the charging member was provided. The volume resistance of the static elimination charging member is calculated at a temperature of 22 ° C. and humidity
When measured in a 60% environment, it is 4 × 10 ⁴ Ω · cm.

Next, 8 parts by weight of the nylon 6-66-10 copolymer and 2 parts by weight of the isocyanate compound (4) are dissolved in 90 parts by weight of methanol, and dip-coated on the conductive elastic layer of the charge removing member. After drying, a resin layer having a thickness of 100 μm was provided to produce a blade-shaped member for static elimination and charging. A resin layer was similarly provided on the aluminum sheet, and the volume resistance was measured.

This static charge member is attached in place of the pre-exposure static remover of the positive development type copying machine PC-20 (manufactured by Canon).
The state of the image and the charge removing member was examined.

 The results are shown in Table 4.

Furthermore, the volume resistance of the resin layer of the charge-eliminating member in a low-temperature and low-humidity state at a temperature of 15 ° C. and a humidity of 10%, and the image and the state of the charge-eliminating member when the charge-eliminating member is attached to the positive development type copying machine are shown. The results are shown in Table 4.

Example 14 In the same manner as in Example 13, a conductive elastic layer of a member for discharging and charging was prepared.

Next, 8 parts by weight of nylon 6-66-10-128 and 2 parts by weight of the isocyanate compound (5) were dissolved in 90 parts by weight of methanol, and dip-coated on the conductive elastic layer of the charge removing member. After drying, a resin layer having a thickness of 100 μm was provided to produce a roller-shaped member for static elimination and charging.

 This was evaluated in the same manner as in Example 13 and shown in the table.

Example 15 In the same manner as in Example 13, a conductive elastic layer of a member for discharging and charging was prepared.

Next, 8 parts by weight of methoxymethylated nylon-6 (methoxymethylation rate 20%) and isocyanate compound (3)
2 parts by weight, dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the charge removing member, and dried.
A 0 μm resin layer was provided, and a blade-shaped transfer charging member was manufactured.

 This was evaluated in the same manner as in Example 13 and shown in Table 4.

Example 16 In the same manner as in Example 12, a conductive elastic layer of a charge removing member was prepared.

Next, methoxymethylated nylon-6 (methoxylation rate 28
%) 7 parts by weight and 3 parts by weight of the isocyanate compound (2) are dissolved in 90 parts by weight of methanol, dip-coated on the conductive elastic layer of the charge removing member, and dried to form a resin layer having a thickness of 100 μm. Then, a blade-shaped member for static elimination charging was manufactured.

 This was evaluated in the same manner as in Example 13 and shown in Table 4.

Comparative Example 13 In the same manner as in Example 13, a conductive elastic layer of a member for discharging and charging was prepared. The charge removing member was used without providing a resin layer. This was evaluated in the same manner as in Example 13 and shown in Table 4.

Comparative Example 14 A charge removing / charging member base layer was prepared in the same manner as in Example 13.

Next, conductive carbon was added to 10 parts by weight of chloroprene rubber.
2 parts by weight and 90 parts by weight of methyl ethyl ketone were added and dispersed by a ball mill.

This dispersion is applied by dip coating on the charge-removing member base layer,
After drying, a resin layer having a thickness of 200 μm was provided to produce a blade-shaped member for static elimination and charging.

This was evaluated in the same manner as in Example 13, and the results are shown in Table 4.

Comparative Example 15 In the same manner as in Example 13, a charge removing member base layer was prepared.

Next, 90 parts by weight of dimethylformamide was dissolved in 10 parts by weight of nylon-66, dip coating was performed on the base layer of the charge eliminating member, and after drying, a resin layer having a thickness of 200 μm was provided. Manufactured.

This was evaluated in the same manner as in Example 13, and the results are shown in Table 4.

Comparative Example 16 In the same manner as in Example 13, a charge eliminating member base layer was prepared.

Next, 5 parts by weight of non-conductive titanium oxide particles, 5 parts by weight of polybutyl methacrylate, and 90 parts by weight of methanol were dispersed in a ball mill and dip-coated on the base layer of the member for static elimination and charging. Was provided to produce a blade-shaped charge removing and charging member.

This was evaluated in the same manner as in Example 13, and the results are shown in Table 4.

As can be seen by comparing Examples 13, 14, 15, and 16 with Comparative Example 13, in the present invention, the leak due to pinholes is suppressed, and the occurrence of image defects is prevented.

Further, as can be seen by comparing Examples 13, 14, 15, and 16 with Comparative Examples 14 and 15, the material of the present invention can suppress image defects even when the volume resistance is almost the same as the surface resistance of the charging member.

In Comparative Example 16, the volume resistance of the surface of the charging member was high, the static elimination performance was low, and a fog defect occurred at low temperature and low humidity.

[Effects of the Invention] As is clear from the above effects, by using the charging member of the present invention, stable potential characteristics can be obtained, image defects are reduced, and leakage due to pinholes can be reduced. In particular, stable potential characteristics and image characteristics can be obtained even under low temperature and low humidity.

[Brief description of the drawings]

1 and 2 are cross-sectional views in the direction of the central axis of a roller-shaped charging member, FIG. 3 is a cross-sectional view of a blade-shaped charging member, FIG. 4, FIG. 5, and FIG. FIG. 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: developing means 9: Transfer charging corona charger 10: Cleaning means, 11: Pre-exposure means 12: Electrophotographic photoreceptor 14: Primary charging corona charger 15: Transfer charging member 16: Static elimination charging member.

Claims (5)

(57) [Claims] 1. A charging member having a conductive elastic layer on a conductive support, comprising: a resin layer containing a polyamide and an isocyanate compound on the conductive elastic layer. 2. A charging member according to claim 1, wherein said charging member contacts said electrophotographic photosensitive member to charge said photosensitive member. 3. The charging member according to claim 1, wherein a DC voltage and an AC voltage are superimposed as an applied voltage to primary charge the electrophotographic photosensitive member. 4. The charging member according to claim 1, wherein a DC voltage is used as an applied voltage or a DC voltage and an AC voltage are superimposed to transfer a developer from an electrophotographic photosensitive member to a member to be transferred. . 5. The charging member according to claim 1, wherein the electrophotographic photosensitive member is neutralized by using an AC voltage as an applied voltage.