JPH04328756A - Member for electrification - Google Patents

Abstract

PURPOSE:To provide a member for electrification capable of stably feeding a high-grade image not causing spotted fog, image defects, etc. CONSTITUTION:A resin layer contg. nitrocellulose represented by a formula (C6H7O2(OH)3-m(NO2)m)n (where 0<m<=3 and 20<=n<=90) is formed on the electric conductive elastic layer of a member for electrification with the elastic layer on the electric conductive substrate to obtain a member for electrification hardly causing a change in the electric resistance due to environmental changes, capable of forming a stable image and almost inhibiting the escape of electric charges.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention 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.

0002

2. Description of the Related Art Conventionally, the charging process in an electrophotographic process using an electrophotographic photoreceptor has mostly involved applying a high voltage (DC 5 to 8 KV) to a metal wire, and charging the metal wire by the generated corona. However, with this method, deterioration of the photoreceptor surface due to corona products such as ozone and NOx during corona generation may cause image blurring and deterioration, or dirt on the wire may affect image quality, resulting in white spots or black lines in the image. There were problems such as causing On the other hand, the current flowing to the photoreceptor is only 5 to 30% of the input power, and most of it flows through the shield plate, making it ineffective as a charging means.

[0003] In order to compensate for these drawbacks, direct charging methods have been researched and many proposals have been made (Japanese Patent Laid-Open No. 57-1
Publication No. 78267, Japanese Unexamined Patent Publication No. 104351/1983,
JP-A-58-40566, JP-A-58-1391
56, JP-A-58-150975, etc.). However, in reality, even when a photoreceptor is charged by the contact charging method as described above, each part of the surface of the photoreceptor is not uniformly charged, resulting in spot-like charging unevenness. For example, in the reversal development method, even if processes after photoimage exposure are applied to a photoreceptor 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 spotted black dot image corresponding to the spotty charging unevenness. As a result, a high-quality image cannot be obtained as a result of the unevenness resulting in a speckled white spot image.

[0004]Also, although there are many proposals for direct charging methods, there is no market experience at all. Reasons for this include difficulty in achieving uniform charging, and 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 axial charge flows to the breakdown point, resulting in no charging.

[0005] In order to prevent this dielectric breakdown, a method of forming a resin layer on the surface has also been reported (Japanese Patent Laid-Open No. 1-20
5180, JP-A-1-211779).

However, these materials also cause large fluctuations in resistance under low temperature and low humidity, resulting in unstable charging properties, or when used in contact with an organic photoreceptor, the surface of the organic photoreceptor and charging This left defects such as the resin becoming compatibilized with the surface of the component and sticking together.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks, and to solve the problem of spot-like fog due to non-uniform charging.
There are almost no image defects caused by discharge dielectric breakdown of the photoreceptor,
An object of the present invention is to provide a charging member that can stably form high-quality images.

[0008]

[Means for Solving the Problems] That is, the present invention provides a charging member having a conductive elastic layer on a conductive support.
This is a charging member characterized by having a resin layer containing nitrocellulose on a conductive elastic layer.

The present invention will be explained in more detail below.

The basic form of the charging member of the present invention is a multilayer structure on a conductive substrate 1, as shown in FIG. The volume resistivity of its constituent resin layer is 106 to 1012Ω・
A range of cm is preferred. Further, as shown in Japanese Patent Application Laid-Open No. 1-73364, the volume resistivity of the resin layer 3 is preferably larger than the volume resistivity of the lower layer 2 in contact with the resin layer. The volume resistivity of the lower layer 2 is 100 to 1011Ω・c
m, particularly preferably in the range of 102 to 1010 Ω·cm. The lower layer 2 is made of a metal such as aluminum, iron, or copper, or a conductive polymer such as polyacetylene, polypyrrole, or polythiophene, carbon in the resin layer, or conductive treatment by dispersing metal, etc. in rubber or insulating resin. Materials or materials obtained by laminating and coating the surface of an insulating resin such as polycarbonate or polyester or rubber with metal or other conductive material can be used. Further, the lower layer 2 may have a multilayer structure in which functions are separated into each layer as necessary. As the conductive substrate 1, iron, copper, corrosion-resistant steel (stainless steel), etc. can be used.

As in the configuration 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 conductivity or surface roughness of the charging member.

In the case of a blade-shaped charging member as shown in FIG. 3, a conductive elastic layer (lower layer) 2 is provided on the conductive sheet metal 1b, and a resin layer 3 is further provided. Further, a protective layer may be provided.

The material used to prepare the charging member of the present invention is nitrocellulose represented by the following general formula.

General formula: [C6 H7 O2 (OH)3
-m (NO2)m ]n where m is 0<m≦3 and n is from 20 to 900.

[0015] Furthermore, the nitrocellulose used in the present invention is classified according to its nitrogen content, and usually has a nitrogen content of 5 to 15% by weight, preferably 9 to 12% by weight.

Furthermore, a binder resin may be added to the resin layer 3. However, the amount of binder resin added is preferably 30% by weight or less based on the total amount of resin. Examples of the binder resin in the resin layer include acrylic resins such as polymethyl methacrylate and polybutyl methacrylate, polyvinyl butyral, polyvinyl acetal, 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 the surface of the photoreceptor may become hard. In some cases, wrinkles may occur, resulting in image defects.

The charging member of the present invention substantially eliminates these drawbacks and provides high quality images.

The charging member having the resin layer containing nitrocellulose of the present invention is difficult to adhere to the electrophotographic photoreceptor;
Since it is also flexible, high-quality images can be formed, and there is little toner stain, and the volume resistance of the resin layer does not change much even under low temperature and low humidity conditions, so it can be used as a stable charging member.

The thickness of the resin layer 3 is selected in the range of 5 to 500 μm, preferably 20 to 200 μm. The charging member may have any shape such as a roller shape or a blade shape.
A roller shape is preferable in terms of uniform charging.

The basic structure of an electrophotographic photoreceptor is that a photosensitive layer is provided on a conductive support. As the conductive support, a support that itself has conductivity, such as a metal such as aluminum, aluminum alloy, corrosion-resistant steel (stainless steel), chromium, titanium, etc., can be used. In addition, the conductive support has a layer formed by vacuum deposition of aluminum, aluminum alloy, indium oxide-tin oxide alloy, etc.; plastic, conductive particles (e.g. carbon black, tin oxide particles, etc.) and a suitable binder. In addition, a support impregnated with plastic or paper; a plastic having a conductive binder, etc. can be used.

[0022] A subbing layer having barrier and adhesive functions can also be provided between the conductive support and the photosensitive layer. The subbing layer can be formed from 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. In order for the undercoat layer to perform its function, it is desirable that its volume resistivity is 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 vapor deposition. In addition, 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. be able to.

The charge generation layer is formed by depositing one or more charge generation materials such as azo pigments, quinone pigments, quinone anine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, and quinacridine pigments on a support. Alternatively, it can be formed by coating a coating liquid dispersed with a suitable binder (binder resin) (or without a binder).

The binder can be selected from a wide variety of insulating resins or organic photoconductive polymers. For example, insulating resins include polyvinyl butyral, polyarylate (
Polycarbonates, polyesters, phenoxy resins, acrylic resins, polyacrylamide resins, polyamides, cellulose resins, urethane resins, epoxy resins, casein, polyvinyl alcohol, etc. Also,
Organic photoconductive polymers include carbazole, polyvinylanthracene, polyvinylpyrene, and the like.

The thickness of the charge generation layer is 0.01 to 15 μm,
The thickness is preferably 0.05 to 5 μm, and the weight ratio of the charge generation layer to the binder is 10/1 to 1/20 (former/latter).

[0027] Solvents used in the paint for the charge generation layer include:
It can be selected based on the solubility and dispersion stability of the resin and charge transport material used. Examples of organic solvents include alcohols, sulfoxides, ethers, esters,
Aliphatic halogenated hydrocarbons or aromatic compounds can be used.

Coating methods include dip coating method, spray coating method, Mayer bar coating method,
This can be carried out using an appropriate coating method such as a blade coating method.

The charge transport layer can be formed by dissolving a charge transport material in a film-forming resin. Examples of organic charge transport materials used in the present invention include hydrazone compounds,
Examples include 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 binders used in the charge transport layer include:
Phenoxy resin, polyacrylamide, polyvinyl butyral, polyarylate, polysulfone, polyamide,
Acrylic resin, acrylonitrile resin, methacrylic resin,
Vinyl chloride resins, vinyl acetate resins, phenolic resins, epoxy 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, and the like. 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, and the weight ratio of the charge transport material to the binder is former/latter = 5/1 to 1/5, preferably 3/5. 1
It is about ~1/3. Coating can be performed using the coating method described above.

Furthermore, in order to compensate for the fact that dyes, pigments, organic charge transport substances, etc. are generally susceptible to UV rays, ozone, stains from oil, etc., and contact with metals, a protective layer is provided thereon as necessary. Good too. In order to form an electrostatic latent image on this protective layer, it is desirable that the surface resistivity is 10 11 Ω or more.

The protective layer is made of a suitable 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, etc. The photosensitive layer can be formed by applying a coating solution dissolved in an organic solvent onto the photosensitive layer and drying it. At this time, the thickness of the protective layer is generally 0.05
It is in the range of ~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 transfer charging means 9, a cleaning means 10, and a pre-exposure means 11 are arranged on the circumferential surface of an electrophotographic photoreceptor 12.

A voltage (for example, 200 V) is applied from the outside to the primary charging member 6 placed in contact with the electrophotographic photoreceptor 12.
DC voltage above 2000V and peak-to-peak voltage 4000V
A pulsating current voltage superimposed with an AC voltage of V or less is applied to charge the surface of the electrophotographic photoreceptor 12, and the image exposure means 7 exposes the image on the document onto the photoreceptor to form an electrostatic latent image. let Next, the electrostatic latent image on the photoreceptor is developed (visualized) by adhering the developer in the developing means 8 to the photoreceptor, and then the developer on the photoreceptor is transferred to the paper by the charging means 9. The cleaning means 10
Collects developer remaining on the photoreceptor without being transferred to paper during transfer.

Although an image can be formed by such an electrophotographic process, if residual charges remain on the photoreceptor, the pre-exposure means 11 is used before primary charging.
It is better to remove the residual charge by exposing the photoreceptor to light.

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. This device includes a corona charger 55 for primary charging, an image exposure means 53,
A developing means 54, a charging member 51 for transfer charging, a cleaning means 59, and a pre-exposure means 58 are arranged.

A voltage (for example, a DC voltage of 40
0 to 1000 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 elimination charging, it can be applied to, for example, an electrophotographic apparatus as shown in FIG. In this device, the electrophotographic photoreceptor 62
A corona charger 65 for primary charging and an image exposure means 6 are provided on the circumferential surface of the
3. A developing means 64, a corona charger 68 for transfer charging, and a cleaning means 67 are arranged.

Charges on the electrophotographic photoreceptor 62 can be removed by applying a voltage (for example, an AC peak-to-peak voltage of 500 to 2000 V) to the charging member 61 for charge removal that is placed in contact with the electrophotographic photoreceptor 62. .

When using the electrophotographic device equipped with the charging member of the present invention as a facsimile printer,
The optical image exposure L is exposure for printing received data. FIG. 7 is a block diagram showing an example of this case.

In FIG. 7, a controller 71 controls an image reading section 70 and a printer 79. The entire controller 71 is controlled by a CPU 77. The read data from the image reading section 70 is transmitted to the partner station through the transmitting circuit 73. Data received from the other station is sent to the printer 79 through the receiving circuit 72. Image memory 7
6 stores predetermined image data. A printer controller 78 controls a printer 79. 74 is a telephone.

After the image received from the line 75 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 72, the image information is decoded by the CPU 77 and sequentially stored in the image memory 75. is stored in next,
Once at least one page worth of images is stored in the memory 76,
Record an image of that page. The CPU 77 reads one page of image information from the memory 76 and sends it to the printer controller 7.
One page of image information decoded into 8 is sent. When the printer controller 78 receives one page of image information from the CPU 77, it controls the printer 79 to record the image information of that page.

Note that while the printer 79 is recording, the CPU 77 is receiving image information for the next page.

As described above, image information is received and recorded.

By applying the charging member of the present invention to an electrophotographic photoreceptor having a photosensitive layer containing an organic photoconductor that is susceptible to deterioration in terms of mechanical strength and chemical stability, the characteristics thereof can be significantly improved. able to demonstrate.

[0047] In the present invention, the method of installing the charging member in contact with the photoreceptor is not limited to a particular method. The charging member can be either a fixed type or a moving type such as rotating in the same direction or opposite direction to the photoreceptor. 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 method of applying it in the direct charging of the present invention, various methods can be adopted depending on the specifications of each electrophotographic apparatus. For example, in addition to the method of instantaneously applying a desired voltage, there is also a method of increasing the applied voltage in stages to protect the photoreceptor, and a method of applying a superimposed direct current and alternating current (DC → AC). Alternatively, a method can be adopted in which voltage is applied in the order of AC → DC.

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

[0050] When primary charging is applied only with DC voltage, uniform charging cannot be achieved. When used for transfer charging, only a DC voltage or a combination of a DC voltage and an AC voltage may be applied. When used for static electricity removal charging,
It is necessary to apply only alternating voltage.

Furthermore, in the present invention, any method known in the field of electrostatic photography can be adopted for processes such as image exposure, development, and cleaning, and the type of developer is not limited to a specific one. . The charging member of the present invention can be used not only in copiers but also in electrophotographic applications such as laser printers, CRT printers, and electrophotographic plate making systems.

[0052]

[Example] Example 1 An aluminum cylinder (outer diameter 6
0 mm x length 260 mm x wall thickness 0.5 mm) was prepared.

Copolymerized nylon [Product name: CM8000 (
(Manufactured by Toray Industries, Inc.)] 4 parts by weight and type 8 Nylon [Product name: Laccamide 5003 (manufactured by Dainippon Ink Co., Ltd.)] 4
Parts by weight were dissolved in a mixed solution of 50 parts by weight of methanol and 50 parts by weight of n-butanol, and the solution was dip-coated onto the above support to form an undercoat layer (0.6 μm thick).

10 parts by weight of a disazo pigment having the following structural formula,

[0055]

[Chemical formula 1] and polyvinyl butyral resin [Product name: S-LEC B
M2 (manufactured by Sekisui Chemical Co., Ltd.)] was mixed and dispersed with 120 parts by weight of cyclohexanone for 10 hours in a sand mill apparatus. A coating solution prepared by adding 30 parts by weight of methyl ethyl ketone to the resulting dispersion was applied onto the undercoat layer to form a charge generation layer (0.15 μm thick).

Prepare 10 parts by weight of polycarbonate Z resin [weight average molecular weight (manufactured by Mitsubishi Gas Chemical Co., Ltd.)], and prepare a hydrazone compound having the following structural formula:

[0057]

embedded image 10 parts by weight were dissolved in 80 parts by weight of monochlorobenzene. This was coated on the charge generation layer to form a charge transport layer (16 μm thick), and electrophotographic photoreceptor No. 1 was manufactured.

Next, 100 parts by weight of chloroprene rubber was melted and kneaded with 5 parts by weight of conductive carbon, and a stainless steel shaft (diameter 8 mm x length 260 mm) was passed through the center of the obtained mass so that the outer diameter was 20 mm x length 240 mm. Molded into
A conductive elastic layer of a roller-shaped charging member was provided. The volume resistivity of the conductive elastic layer of this charging member was measured in an environment of a temperature of 22° C. and a humidity of 60%, and was found to be 3×10 4 Ωcm.

Nitrocellulose [nitrogen content 10.7%,
Product name SS1/8 (manufactured by Daicel)] 10 parts by weight was dissolved in 90 parts by weight of ethyl acetate, and the solution was dip coated on the conductive elastic layer of the charging member, and after drying, a resin layer with a thickness of 200 μm was provided. Thus, a roller-shaped charging member was manufactured. A resin layer was similarly provided on an aluminum sheet, and its volume resistance was measured.

As shown in FIG. 3, this charging member is attached to a normal development type copying machine [product name: PC-20 (manufactured by Canon Inc.)] in place of the primary corona charger, and while being rotated by the electrophotographic photoreceptor. , the primary charging voltage is DC voltage -750V
was superimposed with an AC peak-to-peak voltage of 1500 V, the dark potential and bright potential of the electrophotographic photoreceptor were measured, and the images formed were evaluated. The results are shown in Table 1.

Furthermore, the volume resistance of the resin layer of the charging member, the potential characteristics and the image when this charging member is installed in a normal development type copying machine were similarly evaluated in a low-temperature, low-humidity condition of a temperature of 15° C. and a humidity of 10%. The results 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. Nitrocellulose [nitrogen content 11.2%, product name: S
S1/2 (manufactured by Daicel)] was dissolved in 91 parts by weight of ethyl acetate, and the resulting coating solution was dip-coated on the conductive elastic layer of the charging member to give a film thickness of 200 μm after drying. A roller-shaped charging member was manufactured by providing a resin layer of. This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1. Nitrocellulose [nitrogen content 11.4%, product name: S
S1/2a (manufactured by Daicel)] was dissolved in 91 parts by weight of an ether/ethanol (1/1) mixed solution, and the resulting coating solution was dip-coated onto the conductive elastic layer of the charging member. After drying, a resin layer with 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.

Example 4 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1. Nitrocellulose [nitrogen content 11.7%, trade name: R
S1/2 (manufactured by Daicel)] 8 parts by weight and methoxymethyl nylon 6 [methoxymethylation rate 30%; trade name: EF
-30T (manufactured by Teikoku Kagaku)] was dissolved in 90 parts by weight of ethyl acetate, and the resulting coating solution was dip coated onto the conductive elastic layer of the charging member, and after drying, the film thickness was 200 μm. A roller-shaped charging member was manufactured by providing a resin layer of. This was evaluated in the same manner as in Example 1, and the results are 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. Copolymerized nylon 6-66-610-12 [trade name: Amilan CM-8000 (manufactured by Toray Industries, Inc.)] was dissolved in 10 parts by weight and 87 parts by weight of methanol, and the solution was dip-coated onto the conductive elastic layer of the charging member. After drying, a resin layer with 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 2 A conductive elastic layer of a charging member was prepared in the same manner as in Example 1. 10 parts by weight of polyester polyol (Nipporan 121, manufactured by Nippon Polyurethane) and 3 parts by weight of tolylene diisocyanate were dissolved in 82 parts by weight of n-butanol, and the resulting coating liquid was applied onto the conductive elastic layer of the charging member. A roller-shaped charging member was manufactured by dip coating and providing a resin layer having a thickness of 200 μm after drying. This was evaluated in the same manner as in Example 1, and the results are 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. 10 parts by weight of silicone RTV rubber (manufactured by Toshiba Silicon Co., Ltd.) was dissolved in 84 parts by weight of toluene, dip-coated on the conductive elastic layer of the charging member, and after drying, a resin layer with a film thickness of 200 μm was provided, 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.

(1) Examples 1, 2, 3 and 4 and Comparative Example 1
By comparing the above, it can be seen that: According to the present invention, it is possible to prevent image defects caused by wavy fog caused by hardening of the resin layer at low temperature and low humidity.

(2) Examples 1, 2, 3 and 4 and Comparative Example 2
By comparing 3 and 3, it can be seen that: - It is possible to prevent the charging member from fusing with the photoreceptor, and to suppress the occurrence of horizontal streak images.

- As shown in Comparative Example 2, the polyurethane resin layer exhibits high volume resistance, but by incorporating nitrocellulose into the resin layer as in Examples 1, 2, 3, and 4, an appropriate volume can be achieved. The resistance can be adjusted to provide more useful charging characteristics.

Next, the characteristics as a transfer charger were investigated.

Example 5 A photoreceptor was produced in the same manner as in Example 1. Next, 100 parts by weight of chloroprene rubber was melted and kneaded with 5 parts by weight of conductive carbon, and a stainless steel shaft (diameter 8 mm) was placed in the center of the resulting mass.
x 260mm) through outer diameter 30mm x length 240mm
A conductive elastic layer of a roller-shaped charging member was provided.

The volume resistance of this transfer charging member was determined at a temperature of 22
When measured in an environment of ℃ and 60% humidity, it was 4 x 104 Ωcm. Nitrocellulose [nitrogen content 10.7%, SS1
/4a (manufactured by Daicel)] was dissolved in 90 parts by weight of ether/ethanol (1/1) mixed solution, and applied by dip coating onto the conductive elastic layer of the transfer charging member, and after drying, the film was formed. A roller-shaped transfer charging member was manufactured by providing a resin layer with a thickness of 100 μm. A resin layer was similarly provided on an aluminum sheet, and its volume resistance was measured.

This transfer charging member is used in a normal development type copying machine [
Product name: PC-20 (manufactured by Canon Inc.)] was used instead of a transfer corona charger, and -500 V DC was applied for transfer charging to evaluate the image and the state of the transfer charging member. The results are shown in Table 2.

Furthermore, the volume resistance of the resin layer of the transfer charging member under low temperature and low humidity conditions of 15° C. and 10% humidity, the image when this transfer charging member is installed in a normal development type copying machine, and the transfer charging member The results of evaluating the condition are shown in Table 2.

Example 6 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Nitrocellulose [nitrogen content 10.8%, SS1
/4b (manufactured by Daicel)] was dissolved in 88 parts by weight of ethyl acetate, and the resulting coating liquid was dip coated onto the conductive elastic layer of the transfer charging member, and the film thickness after drying was determined. 100μ
A roller-shaped transfer charging member was manufactured by providing m resin layers. Table 2 shows the results of evaluating this in the same manner as in Example 5.
Shown below.

Example 7 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Nitrocellulose [nitrogen content 10.9%, SS
1/8 (manufactured by Daicel)] was dissolved in 89 parts by weight of ethyl acetate, and the resulting coating solution was dip coated onto the conductive elastic layer of the transfer charging member, and the film was dried. Thickness 100μ
A roller-shaped transfer charging member was manufactured by providing m resin layers. Table 2 shows the results of evaluating this in the same manner as in Example 5.
Shown below.

Example 8 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Nitrocellulose [nitrogen content 11.4%, SS1
10 parts by weight of /2b (manufactured by Daicel) and 3 parts by weight of methoxymethylated nylon 6 (methoxymethylation rate 25%) were dissolved in 87 parts by weight of ethyl acetate, and the resulting coating liquid was applied to the conductive layer of the transfer charging member. A resin layer having a thickness of 100 μm after drying was provided on the elastic layer by dip coating to produce a roller-shaped transfer charging member. This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

Comparative Example 4 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Copolymerized nylon-6-66-610-12 1
0 parts by weight of methanol is dissolved in 84 parts by weight of methanol, and the resulting coating liquid is dip coated onto the conductive elastic layer of the transfer charging member to provide a resin layer with a thickness of 100 μm after drying, A roller-shaped transfer charging member was manufactured. Example 5
Table 2 shows the results of the same evaluation.

Comparative Example 5 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Next, 8 parts by weight of polyester polyol [trade name: Nipporan 121 (manufactured by Nippon Polyurethane Co., Ltd.)] and 2 parts by weight of tolylene diisocyanate were dissolved in 85 parts by weight of n-butanol, and the resulting coating liquid was applied to the transfer charging member. Dip coating on the conductive elastic layer of 100μ thick after drying.
A roller-shaped transfer charging member was manufactured by providing m resin layers. Table 2 shows the results of evaluating this in the same manner as in Example 5.
Shown below.

Comparative Example 6 A conductive elastic layer of a transfer charging member was prepared in the same manner as in Example 5. Next, add 10 parts by weight of silicone RTV rubber to 8 parts by weight of toluene.
The resulting coating solution was applied by dip coating onto the conductive elastic layer of the transfer charging member, and the film thickness after drying was 10.
A roller-shaped transfer charging member was manufactured by providing a 0 μm resin layer. This was evaluated in the same manner as in Example 5, and the results are shown in Table 2.

(1) Examples 5, 6, 7 and 8 and Comparative Example 4
Comparison of the results shows the following: - By using the charging member of the present invention, high image quality can be maintained even under low temperature and low humidity conditions without causing a decrease in density or wavy fog.

(2) Examples 5, 6, 7 and 8 and Comparative Example 5
Comparing 6 and 6 shows the following: According to the present invention, the transfer charging member does not fuse with the photoconductor, nor does it fuse with the toner, so that the transfer charging member does not adhere to the photoconductor or the charging member. Also, images can be formed without causing defects.

[0084] Next, the characteristics as a static eliminator were investigated.

Example 9 A photoreceptor was produced in the same manner as in Example 1.

Next, 100 parts by weight of chloroprene rubber was melted and kneaded with 5 parts by weight of conductive carbon, and the resulting mass was placed on a stainless steel plate (2 mm x 260 mm) in the shape of a plate (free length 10 mm x 240 mm) as shown in Figure 3. ), and a conductive elastic layer made of a blade-shaped charging member was provided. The volume electrical resistance of this static eliminating charging member is determined at a temperature of 22°C and a humidity of 60%.
When measured in the following environment, it was 4 x 104 Ωcm. 10 parts by weight of nitrocellulose [nitrogen content 11.0%, SS1/2 (manufactured by Daicel)] was mixed with ether/ethanol 90% (
1/1) Dissolve in 90 parts by weight of the mixed liquid and dip coat the obtained coating liquid on the conductive elastic layer of the static elimination charging member,
A resin layer having a thickness of 100 μm after drying was provided to produce a blade-shaped static elimination/charging member. A resin layer was similarly provided on an aluminum sheet, and its volume resistance was measured.

[0087] This static elimination charging member is used in a normal development type copying machine [
Product name: PC-20 (manufactured by Canon Inc.)] is installed in place of the pre-exposure static eliminator, and AC peak-to-peak voltage 10 is used for static charge removal.
00V was applied, and the residual potential after static elimination, the image, and the state of the static elimination charging member were evaluated. The results are shown in Table 3.

Furthermore, the volume resistance of the resin layer of the static eliminating charging member in a low temperature and low humidity condition of 15° C. and 10% humidity, the image when this static eliminating charging member is installed in a normal development type copying machine, and the static eliminating charging member The results of evaluating the condition are shown in Table 3.

Example 10 In the same manner as in Example 9, a conductive elastic layer of a static electricity removal/charging member was prepared. Nitrocellulose [nitrogen content 11.1%, SS1
/4a (manufactured by Daicel)] was dissolved in 88 parts by weight of an ether/ethanol (1/1) mixed solution, and the resulting coating solution was dip-coated on the conductive elastic layer of the static elimination/charging member. A blade-shaped static elimination/charging member was manufactured by providing a resin layer having a thickness of 100 μm after drying. Example 9
Table 3 shows the results of the same evaluation.

Example 11 In the same manner as in Example 9, a conductive elastic layer of a static elimination/charging member was prepared. Nitrocellulose [nitrogen content 11.4%, SS1
/2 (manufactured by Daicel)] 13 parts by weight was dissolved in 87 parts by weight of ethyl acetate, and the resulting coating liquid was dip coated on the conductive elastic layer of the static elimination/charging member to give a film thickness of 100 μm after drying. A blade-shaped static elimination/charging member was manufactured by providing a resin layer of. This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Example 12 In the same manner as in Example 9, a conductive elastic layer of a static electricity removal/charging member was prepared. Nitrocellulose [nitrogen content 11.9%, SS1
/4 (manufactured by Daicel)] 14 parts by weight was dissolved in 86 parts by weight of ethyl acetate, and the resulting coating liquid was dip coated on the conductive elastic layer of the static elimination/charging member, and the film thickness after drying was 100μm
A blade-shaped static elimination/charging member was manufactured by providing a resin layer of. This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 7 In the same manner as in Example 9, a conductive elastic layer of a static elimination/charging member was prepared.

[0093] The above-mentioned charge eliminating member was used as it was without being provided on the resin layer. This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 8 In the same manner as in Example 9, a conductive elastic layer of a static electricity removal/charging member was prepared. 12 parts by weight of polyester polyol (Nipporan 121, manufactured by Nippon Polyurethane) and 1 part by weight of tolylene diisocyanate were dissolved in 84 parts by weight of n-butanol,
The obtained coating liquid was dip-coated on the conductive elastic layer of the static elimination/charging member, and a resin layer having a thickness of 100 μm after drying was provided to produce a blade-shaped static eliminating/charging member. This was evaluated in the same manner as in Example 9, and the results are shown in Table 3.

Comparative Example 9 Table 3 shows the results of evaluation in the same manner as in Example 9, in which static electricity was removed during pre-exposure without using the charging member for charge removal of the present invention.

[0096]

[Table 1]

[0097]

[Table 2]

[0098]

[Table 3]

0099

Effects of the Invention The contact charging member of the present invention does not cause much change in electrical resistance due to environmental changes and can form stable images. In addition, charge loss is less likely to occur.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a contact charging device equipped with a contact charging member of the present invention.

FIG. 2 is a schematic cross-sectional view of a transfer type image forming apparatus equipped with a contact charging member of the present invention.

FIG. 3 is a schematic cross-sectional view of a flat plate form of the charging member of the present invention.

FIG. 4 is a schematic cross-sectional view of one embodiment of an electrophotographic apparatus equipped with a charging member of the present invention.

FIG. 5 is a schematic cross-sectional view of another embodiment of an electrophotographic apparatus equipped with a charging member of the present invention.

FIG. 6 is a schematic cross-sectional view of another embodiment of an electrophotographic apparatus equipped with a charging member of the present invention.

FIG. 7 is a block diagram of a facsimile machine whose constituent unit is a printer equipped with the charging member of the present invention.

[Explanation of symbols]

1 Conductive support 2 Lower layer 3 Resin layer 4 Protective layer 5 Insoluble resin powder 41 Charging member 42 Electrophotographic photoreceptor 43 Image exposure means 44 Developing means 45 Transfer charging means 47 Cleaning means 48 Pre-exposure means 51 Charging member 52 Electrophotographic photoreceptor 53 Image exposure means 54 Developing means 55 Transfer charging means 57 Cleaning means 58 Pre-exposure means 61 Charging member 62 Electrophotographic photoreceptor 63 Image exposure means 64 Developing means 65 Transfer charging means 67 Cleaning means 68 Pre-exposure means 70 Image reading section 71 Controller 72 Receiving circuit 73 Transmission circuit 74 Telephone 75 line 76 Image memory 77 CPU 78 Printer controller 79 Printer

Claims (8)

[Claims] 1. A charging member having a conductive elastic layer on a conductive support, characterized by having a resin layer containing the following nitrocellulose on the conductive elastic layer: [ C6 H7 O2 (OH)3-m
(NO2)m]nHere, 0<m≦3, and n is 20
≦n≦900. 2. The charging member according to claim 1, for charging an electrophotographic organic photoreceptor by contact with the photoreceptor. 3. The charging member according to claim 1, wherein the charging member is primarily charged by applying a DC voltage and an AC voltage in a superimposed manner. 4. The charging member according to claim 1, for transferring the developer from the electrophotographic photoreceptor to the transfer target member by applying a DC voltage and an AC voltage in a superimposed manner. 5. The charging member according to claim 1, for eliminating static electricity by applying an alternating current voltage. 6. The charging member according to claim 1 and a member to be charged that is charged by contacting the contact charging member are integrally supported together with at least an electrophotographic photoreceptor to form a unit, and the unit is detachably attached to an apparatus main body. An electrophotographic device unit characterized in that it is a single unit capable of forming an electrophotographic device. 7. An electrophotographic apparatus comprising an electrophotographic photoreceptor, a latent image forming means, a means for developing the formed latent image, and a means for transferring the developed image to a transfer material, wherein the charging member is the electrophotographic device according to claim 1. An electrophotographic device characterized by being as described in . 8. A facsimile machine comprising an electrophotographic apparatus equipped with the charging member according to claim 1 and a receiving means for receiving image information from a remote terminal.