JP2002214879A - Charging member and charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging member which hardly sticks to a photoreceptor and having low friction with which proper image quality can be obtained in a copying machine, printer or the like, and to provide an electrifying device which uses the electrifying member. SOLUTION: The charging member 20 which is to be in contact with the body to be electrified for applying a voltage between the member and the objective body to charge the objective body is composed of an elastic layer 22, and at least one coating film layer 23 formed in the outside of the elastic layer. The coating layer is formed of a fluorocarbon resin, having active hydrogen in the molecular end is which 0.05 to 30 parts by weight of silicone oil, having one or two reactive functional groups in one molecular end, is added with respect to 100 parts by weight of the fluorocarbon resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member for charging a member to be charged such as a photoreceptor used in an electrostatic latent image process in a copying machine, a printer, or the like, and the charging member provided with the charging member. The present invention relates to a charging device.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic process in a copying machine, a printer, or the like, first, the surface of a photoreceptor is uniformly charged, and an image is projected on the photoreceptor from an optical system, and a portion of the photoreceptor exposed to light is exposed. A method of forming a latent image by erasing the charge, then supplying a toner to the latent image, forming a toner image by attaching the toner, and transferring the toner image to a recording medium such as paper for printing. Is adopted. As a method for charging the photoconductor, a corona discharge method has been generally adopted. However, this corona discharge method requires application of a high voltage of 6 to 10 kV, which is not only unfavorable from the viewpoint of machine safety and maintenance, but also generates harmful substances such as ozone during corona discharge. There was a problem above. Therefore, charging can be performed at a lower voltage than the corona discharge, and
Efforts have been made to a charging method capable of suppressing generation of harmful substances such as ozone. As an attempt of such a charging method, a so-called contact method has been proposed in which a charging member to which a voltage is applied is brought into contact with a charged object such as a photosensitive member with a predetermined pressing force to charge the charged object. As a charging member used in this contact charging method, for example, acrylic, urethane, nylon, nylon, or the like is used on the surface of an elastic layer such as rubber or urethane foam in order to ensure surface smoothness, adjust resistance, and improve charging properties. It is known to have a coating layer formed by applying a resin solution such as ethylene or epoxy by a dipping method or a spray method.

[0003]

However, in this charging contact system, the resin constituting the coating layer contacts the photosensitive member for a long period of time, so that close contact with the photosensitive member occurs,
As a result, a part of the coating layer may be peeled off and the surface of the photoreceptor may be contaminated. Furthermore, depending on the strength of the adhesiveness of the resin, friction between the resin and the photoconductor may cause toner fusion or photoreceptor shaving, which may cause an image defect. The coating film is required to have low tackiness. So recently,
Attempts have been made to reduce the tackiness of the charging member by applying a fluorine-based resin to the outermost surface of the coating film layer, but it is difficult to sufficiently cope with high image quality using only the above method. Was. As a remedy, a method of adding a non-reactive silicone oil to the resin of the coating layer has been proposed.If the addition amount is too large, the silicone oil bleeds to the surface of the coating layer, and on the contrary, However, there is a problem that the photoconductor is contaminated.

[0004] The present invention has been made in view of the conventional problems, and a charging member that can obtain good image quality in a copying machine, a printer, and the like, is difficult to adhere to a photoreceptor, and has low friction. It is an object to provide a charging device using the charging member.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a charging member is added with an elastic layer and a silicone oil having one or two reactive functional groups at one end. And a coating layer formed from a fluororesin having an active hydrogen at the terminal, thereby achieving the above object, and the present invention has been accomplished. That is, the invention according to claim 1 contacts the member to be charged,
A charging member for applying a voltage between the charged body and the charged body to charge the charged body includes an elastic layer and at least one coating layer formed outside the elastic layer. A silicone oil having one or two reactive functional groups at one end of a fluororesin,
It is characterized by being formed from a fluororesin having an active hydrogen at the end added in an amount of 0.05 to 30 parts by weight with respect to parts by weight. By reducing friction between the charged member and the surface of the charged member, it is possible to prevent the surface of the charged member from deteriorating due to peeling of the coating layer, fusion of the toner, or scraping of the photosensitive member.

The invention according to claim 2 is characterized in that the coating layer (resin layer) formed from the fluororesin contains a bifunctional or more functional isocyanate crosslinker. The invention described in claim 3 is characterized in that the resin layer contains a conductive powder. In the invention according to claim 4, the elastic layer has a density of 0.05 to 0.05.
It is composed of urethane foam of 0.9 g / cm ³ . The invention according to claim 5 is characterized in that, when a load of 100 gf is applied to the charging member, cellulose 100 is charged.
%, 30 g / m ³ , 70 mesh cloth, the coefficient of friction of the resin layer is 0.4 or less.

According to a sixth aspect of the present invention, there is provided an object to be charged, a charging member for contacting the object to be charged and charging the object to be charged, and a charging member between the charging member and the object to be charged. A voltage applying means for applying a voltage,
As the charging member, the charging member according to any one of claims 1 to 5 is used, which can prevent deterioration of the surface of the member to be charged. Good image quality can be obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Since the charging member of the present invention is used in a contact charging system, its shape is not particularly limited as long as it contacts the member to be charged. Various shapes such as a shape can be applied, and a roll shape is usually preferable. In the case of a roll shape, a metal or plastic shaft may be provided inside these. The structure of the charging member provided by the present invention includes an elastic layer and at least one coating layer, wherein an elastic body is used as the elastic layer, and a resin layer is used as the coating layer. As the roll-shaped charging member, for example, as shown in FIGS. 1A and 1B, a metal or plastic shaft 21, an elastic layer 22 formed on the outer periphery of the shaft 21, The charging roller 20 includes a coating layer 23 formed on the surface of the substrate 22 and formed of a resin to which a conductive agent is added. The coating layer 23 is, for example, as shown in FIG.
The charging roller 20 may be formed as a two-layer structure including a surface layer 23A constituting the surface of the charging roller 20 and an intermediate layer 23B formed between the surface layer 23A and the elastic layer 22, or may be formed from three or more layers. You may.

The elastic layer used in the charging member of the present invention is not particularly limited, but can be formed of rubber, resin, or foam which has been conventionally used as the elastic layer of the charging member. Specifically, a rubber having a base rubber of polyurethane, silicone rubber, butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, polynorbornene rubber, styrene-butadiene-styrene rubber, epichlorohydrin rubber, or the like The composition is exemplified, but polyurethane is particularly preferable, and polyurethane foam having an expansion ratio of 1.5 to 50 is more preferably used. In this case, the density of the foam is 0.05
About 0.9 g / cm ³ is appropriate. A predetermined conductivity can be imparted to the elastic layer by adding a conductive agent such as an ionic conductive agent and an electronic conductive agent.

Here, examples of the ion conductive agent include tetraethylammonium, tetrabutylammonium, lauryltrimethylammonium, dodecitrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified aliphatic. Ammonium such as perchlorate such as dimethylethylammonium, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate, etc. Salts or perchlorates, chlorates, hydrochlorides, bromates, iodates, borohydrofluorides, trifluorides of alkali metals or alkaline earth metals such as lithium, sodium, calcium, magnesium, etc. Oromechiru sulfate, and sulfonic acid salts.

On the other hand, examples of the electronic conductive agent include conductive carbon black such as Ketjen black and acetylene black, SAF, ISAF, HAF, FEF, GPF, and the like.
Rubber carbon black such as SRF, FT, MT, etc., carbon black for ink subjected to oxidation treatment, pyrolytic carbon black, graphite, or conductive metal oxide such as tin oxide, titanium oxide, zinc oxide, nickel,
Examples include metals such as copper. One of these conductive agents may be used, or two or more thereof may be used in combination. Also, the amount of these conductive agents is not particularly limited,
Although it is appropriately selected according to various situations, in the case of the ionic conductive agent, it is usually 0.01 to 100 parts by weight of the rubber material.
To 5 parts by weight, preferably 0.05 to 2 parts by weight. In the case of an electronic conductive agent, the amount is usually 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight. Thereby, the volume resistivity of the elastic layer is 10 ³ to 10 ¹⁰ Ω · cm,
In particular, it is preferable to adjust to 10 ⁴ to 10 ⁸ Ω · cm.
In addition, the conductive elastic layer may include other conductive agents, fillers, cross-linking agents, foaming agents, and the like, if necessary, in addition to the above-described conductive agents.
Other rubber additives can be appropriately added.

Further, the coating layer is composed of a resin layer to which one or more conductive materials are added. In the resin layer of the present invention, as the fluororesin used in the surface layer, for example, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer,
Tetrafluoroethylene-hexafluoropropylene-
Perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene-ethylene copolymer, tetrafluoroethylene-vinylidene fluoride copolymer, polyvinylidene fluoride and polyvinyl Fluoride and the like. These fluororesins include an aqueous resin type and an organic resin type. The organic resin type is particularly excellent in water resistance and does not depend on the environment, particularly, polytetrafluoroethylene and tetrafluoroethylene-perfluoroalkylvinyl ether. Organic resin types such as copolymers, tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymers, and tetrafluoroethylene-ethylene copolymers are preferred. These fluorine-based resins may be used alone or in combination of two or more. The water-based resin type means a resin that can be dissolved or dispersed in water using water as a solvent. Further, the organic solvent-based resin type means a resin that can be dissolved or dispersed in an organic solvent using a solvent as an organic solvent.

In the present invention, another resin can be added to the fluororesin as required. At this time, examples of other resins used include acrylic resin, polyurethane resin, nylon resin, silicone resin, polyester resin, epoxy resin, cellulose, melamine resin, and the like.From the viewpoint of improving dispersibility, acrylic resin is used. , Polyurethane resin and nylon resin are preferred. These may be added alone or in combination as appropriate.

The surface layer of the charging member of the present invention can be controlled to a predetermined resistance value by adding a conductive agent such as carbon black. The resistance of this surface layer is
The volume resistivity is preferably 10 ³ to 10 ¹² Ω · cm, more preferably 10 ⁵ to 10 ¹⁰ Ω · cm.
When carbon black is used as the conductive agent, it is added usually at a rate of 0.01 to 40% by weight, preferably 5 to 20% by weight, based on the total amount of the surface layer. Although the thickness of this surface layer is not particularly limited, it is 50 μm or less, particularly 1 to 30 μm.
The thickness is preferably set to μm, and if it exceeds 50 μm, the surface layer becomes hard, and the flexibility of the surface layer may be impaired.
Further, it is also possible to form a multilayer structure, in which case the outermost surface layer has a specific surface area of at least 10% with the fluororesin.
It is sufficient that the carbon black contains 0 m ² / g or more, and the lower layer may be made of any resin. Here, the resin and the conductive agent used for the lower layer may be the same as the resin and the conductive agent exemplified for the surface layer. In addition, a crosslinking agent, a thickener,
A thixotropy-imparting agent, a structural viscosity-imparting agent, and the like can be appropriately added as needed. The above-mentioned thickener, thixotropy-imparting agent and structural viscosity-imparting agent are appropriately selected from inorganic and organic ones. The method for forming the surface layer is not particularly limited as long as the surface layer that satisfies the above-mentioned conditions is formed from a fluororesin and carbon black, and is not particularly limited.
A spray method, an extrusion method, or the like can be used.

In the present invention, by adding a silicone oil having one or two reactive functional groups at one end to the resin layer, adhesion and friction with the member to be charged are successfully reduced. did. Since the above-mentioned silicone oil can appropriately select an isocyanate cross-linking agent and a silicone functional group, it is easy to design, manufacture and control, and a large amount can be blended. Examples of the functional unit include an amino group, a hydroxyl group, a carboxyl group, an epoxy group, and an acrylic group. In a silicone oil having an amino group, a hydroxyl group, and a carboxyl group, the silicone oil is fixed to the resin through a reaction with an isocyanate. You. In the case of silicone oil having an epoxy group, it reacts with the active hydrogen of the fluororesin and is directly fixed to the resin. As a result, the adhesion / frictional force on the surface of the coating film layer is reduced, and these can also prevent bleeding of silicone oil. Also,
Naturally, a large amount of silicone oil can be contained. In the case of such a composition, in the silicone oil, the side having no functional group tends to be occupied by the surface due to the non-polar nature of silicone.
That is, while the silicone oil modified at both ends is uniformly distributed as a whole, the silicone oil having a reactive functional group at one end used in the present invention is the silicone oil on the surface side in the surface layer. The occupancy is high, so that an inclined structure is taken. As a result, even with the same amount of silicone oil, the adhesion and frictional force of the surface of the coating layer are more likely to be reduced than in the case of modifying both ends. In addition, the silicone oil is a fluororesin 100
It is preferable to add 0.05 to 30 parts by weight based on parts by weight.

It should be noted that gelation, phase separation,
When unreacted substances are generated, a method of prepolymerizing silicone oil and isocyanate, or silicone oil and fluororesin, or adding a catalyst may be used. Further, by combining the external additive with silica particles, the contact area may be reduced and the adhesion may be further improved. A desired conductivity can be imparted to this surface layer by adding the same conductive agent as that described above, preferably carbon. The thickness of the surface layer is not particularly limited, but is preferably 30 μm or less, particularly preferably 3 to 20 μm, and more preferably 30 μm.
If it exceeds m, it becomes hard and the flexibility of the coating film layer is impaired.

The polyisocyanate compound added as a cross-linking agent is a compound having two or more isocyanate groups in the molecule, and can be the same as the polyisocyanate generally used as a raw material for producing polyurethane. . Specifically, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI),
Trizine diisocyanate (TODI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), cyclohexane diisocyanate, lysine ester triisocyanate, undecane triisocyanate, Hexamethylene triisocyanate, triphenylmethane triisocyanate, and polymers, derivatives, modified products, hydrogenated products, and the like of these isocyanate compounds. Among them, particularly, aliphatic or alicyclic isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and polymers, derivatives and modified products thereof are preferably used because of their excellent ozone resistance and heat resistance.

The fluororesin used as the outermost layer in the coating film layer of the present invention may be either an aqueous resin type or an organic solvent type resin. From the viewpoints of securing, durability, uniform charging, and stabilizing production, it is preferable to sandwich one or more aqueous resins between the elastic layer and the elastic layer. The aqueous resin type used here may be any type as long as the solvent is water, and includes a water-soluble type, an emulsion type, and a suspension type. Particularly, a resin having active hydrogen such as a carboxyl group, a hydroxyl group, and an amino group. Is preferably used. For example, polyester, acrylic, urethane,
Examples thereof include hot water-soluble systems such as polydioxolan, and the like. Particularly, when an acrylic resin is used, compared to urethane and nylon which have been conventionally cited as resins for a charging member,
Since the dielectric constant is considerably small, the capacitance is also small, and the electric attraction and repulsion between the charging member and the photoreceptor due to the application of the alternating current is reduced, so that the charging noise is improved. Particularly, among acrylic resins, the glass transition temperature is −50 ° C.
A soap-free emulsion type having a carboxyl group or hydroxyl group content of 2 to 5% by weight at a temperature of 10 ° C. or lower and a soap-free emulsion type is preferable because of its good crosslinking effect and low hardness. The intermediate layer may be provided with conductivity by adding a conductive agent, but the conductive agent to be used is not limited, and carbon is particularly used.

In this case, the carbon used is particularly limited.
Although not specified, the oxygen content is 5% or more, especially
It is preferably at least 7%, more preferably at least 9%.
PH must be 5 or more, especially 6 or more, and more preferably 7 or more.
Is preferred. That is, the normal oxygen content of carbon
Is about 0.1 to 3%. In addition, oxidation treatment is partially applied.
Although some carbon has been treated,
The pH increases with increasing oxygen content as the oxygen content increases slightly.
Tend to shift to the acidic side,
In some cases, the stability may decrease when added to aqueous resins.
There is. On the other hand, a camera preferably used in the present invention is used.
Carbon is not neutral despite its high oxygen content
The sashimi is maintained alkaline, and stable
It can be added to fats. In addition, gull on the carbon surface
Add functional groups such as boxyl group, hydroxyl group, ketone group, etc.
Some of the hydrogen contained in these groups also
Those substituted with potassium metal are preferably used. these
The resistance of the layer is a volume resistivity of 10^Three-10¹²Ω · cm,
Especially 10^Five-10 ^TenΩ · cm.
The addition amount of ordinary carbon is 0.01 to 40% by weight, especially 5 to 40% by weight.
About 20% by weight.

The method for forming the coating layer is not particularly limited, but is a method in which a paint containing each component forming each of these layers is prepared, and the paint is applied by dipping or spraying. Is preferably used. In any configuration, the resistance suitable for the charging member of the present invention is preferably such that the volume resistivity is 10 ² to 10 ¹² Ω · cm, particularly 10 ⁵ to ¹⁰ 10 to obtain a good image. It is preferably Ω · cm. Also,
If the surface of the charging member manufactured as described above has irregularities, the toner is clogged and causes a defective image. Therefore, it is preferable that the surface is as smooth as possible. In Rz, 4 μm or less, and 3
It is preferably at most 2 μm, particularly preferably at most 2 μm.

In the charging member formed by the above method, a load of 100 gf was applied to the charging member, and cellulose 1
When the coefficient of friction of the above-mentioned coating layer was measured with respect to a 00%, 30 g / m ³ , 70 mesh cloth, the coefficient of friction was found to be 0.4.
It was below. Hereinafter, a method of measuring a coefficient of friction performed in an embodiment of the present invention described below will be described with reference to FIG. The measurement was performed using a friction tester “H” manufactured by Shinto Kagaku Co., Ltd.
EIDON Tribokia "was used. First, the roll-shaped charging member 1 is moved to a movable stage 5 provided on a base 51.
2 fixed on 100% cellulose, 30 g /
m ³ , 70 mesh cloth (Bencott lint free) 2
To the charging member 1 and pressurizing means 5
3. Apply a load of 100 gf according to 3, friction speed 100 mm
/ Min, and the friction resistance at this time is measured by the load cell 54, and the friction coefficient of the charging member 1 with respect to the Bencot lint-free 2 is obtained from the measured friction resistance value. In addition, cellulose 1 was used as a mating material for friction.
The reason why the cloth of 00%, 30 g / m ³ and 70 mesh is selected is that it has the highest correlation with the surface properties of the charging member and that the measuring range of the measuring device is appropriate.

As the charging device of the present invention, for example, as shown in FIG.
In addition, the charging roller 20 serving as the charging member of the present invention is driven to rotate while being in contact with the charging roller 20, and a DC voltage or an AC voltage is superimposed on the DC voltage between the photosensitive drum 10 and the charging roller 20 by the voltage applying unit 30. A charging device configured to charge the photosensitive drum 10 by applying the applied voltage can be exemplified. Note that the charging device to which the charging member of the present invention is attached is not limited to this, and the form of the member to be charged or the charging member, the voltage application method by the voltage application unit, or the like may be appropriately changed.

<Examples> The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following. Example 1 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer B having a thickness of 10 μm was further formed thereon. Produced. The coating layer A is formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and has a volume resistivity of 5 × 1.
It was adjusted to 0 ⁷ Ω · cm. Coating layer B is made of fluororesin LF
200 (Asahi Glass KK) was dissolved in a mixed solvent of MEK / toluene, and an isocyanate crosslinking agent and carbon were added.
2 parts by weight of DX (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by weight of the fluororesin. The surface roughness of the roller was 0.8 μm in JIS ten-point average roughness Rz. This roller was heated at a temperature of 22 ° C./humidity of 50% RH under the conditions of 100% cellulose, 30 g / m ³ , 70%
When a friction test was performed using a mesh cloth, the friction coefficient was 0.25. Further, when the above roller was mounted on a printer cartridge and left at a temperature of 40 ° C./humidity of 95% RH for 2 weeks, no close contact with the OPC was observed. When an image was formed using the cartridge, a good image was obtained. Further, no image deterioration was observed even when 6,000 images were continuously output.

Example 2 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer C having a thickness of 10 μm was further formed thereon. A charging roller was manufactured. The coating layer A was formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. Coating layer C
After dissolving the fluororesin LF200 (Asahi Glass KK) in a mixed solvent of MEK / toluene and adding an isocyanate crosslinking agent and carbon, a bifunctional alcohol-modified silicone oil X-22-176DX (manufactured by Shin-Etsu Chemical Co., Ltd.) is added to the fluororesin 100 1 part by weight was added to the parts by weight. The surface roughness of the roller is JIS ten point average roughness Rz
Was 0.6 μm. This roller is heated at a temperature of 22 ° C. /
Under the condition of a humidity of 50% RH, the above-mentioned cellulose 100
%, 30 g / m ³ , and a 70-mesh cloth, a friction test showed a coefficient of friction of 0.22. Also,
Attach the above roller to the printer cartridge,
When left at 0 ° C / 95% RH for 2 weeks, OP
No close contact with C was observed. When an image was formed using the cartridge, a good image was obtained. Further, no image deterioration was observed even when 6,000 images were continuously output.

Example 3 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer D having a thickness of 10 μm was further formed thereon. A charging roller was manufactured. The coating layer A was formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The coating layer D is
Dissolve fluororesin LF600 (Asahi Glass KK) in a mixed solvent of MEK / toluene, add isocyanate cross-linking agent and carbon,
22-173DX (Shin-Etsu Chemical Co., Ltd.)
1 part by weight was added to 00 parts by weight. The surface roughness of the roller is JIS ten point average roughness Rz, 0.7
μm. This roller was heated at a temperature of 22 ° C and a humidity of 50%.
Under the condition of RH, the above-mentioned cellulose 100%, 30 g /
When a friction test was performed using a cloth of m ³ and 70 mesh, the coefficient of friction was 0.20. Further, the above roller is mounted on a printer cartridge, and the temperature is set to 40 ° C./humidity 9
When left at 5% RH for 2 weeks, no close contact with OPC was observed. When an image was formed using the cartridge, a good image was obtained.

Comparative Example 1 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer E having a thickness of 10 μm was further formed thereon. A charging roller was manufactured. The coating layer A was formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The coating layer E is
Fluororesin LF600 (Asahi Glass KK) was dissolved in a mixed solvent of MEK / toluene, and an isocyanate crosslinking agent and carbon were added. The surface roughness of the roller was 0.7 μm in JIS ten-point average roughness Rz. This roller was subjected to a friction test using a cloth of 100% cellulose, 30 g / m ³ , and 70 mesh under the conditions of a temperature of 22 ° C. and a humidity of 50% RH. As a result, the friction coefficient was 0.60. . Further, when the roller was mounted on a printer cartridge and left at a temperature of 40 ° C./95% RH for 2 weeks, adhesion to OPC occurred. Further, when an image was formed using the cartridge, one streak pattern was seen in the horizontal direction at the period of the photoconductor.

Comparative Example 2 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer F having a thickness of 10 μm was further formed thereon. A charging roller was manufactured. The coating layer A was formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The coating layer F
Fluororesin LF200 (Asahi Glass KK) was dissolved in a mixed solvent of MEK / toluene, and an isocyanate crosslinking agent and carbon were added. The surface roughness of the roller was 0.8 μm in JIS ten-point average roughness Rz. This roller was subjected to a friction test using a cloth of 100% cellulose, 30 g / m ³ , and 70 mesh as described above under the conditions of a temperature of 22 ° C. and a humidity of 50% RH. As a result, the friction coefficient was 0.55. . Further, when the roller was mounted on a printer cartridge and left at a temperature of 40 ° C./95% RH for 2 weeks, adhesion to OPC occurred. Further, when an image was formed using the cartridge, one streak pattern was seen in the horizontal direction at the period of the photoconductor.

Comparative Example 3 A coating layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a coating layer G having a thickness of 10 μm was further formed thereon. A charging roller was manufactured. The coating layer A was formed by applying a paint obtained by adding carbon to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The coating layer G is
Fluororesin LF600 (Asahi Glass KK) is dissolved in a mixed solvent of MEK / toluene, and isocyanate curing agent and carbon are added.
(Toray Dow Corning) was added in an amount of 40 parts by weight based on 100 parts by weight of the fluororesin. The surface roughness of the roller was 0.7 μm in JIS ten-point average roughness Rz. This roller is heated at a temperature of 22 ° C./humidity of 50% RH under the conditions of 100% cellulose, 30 g / m ³ , 7
When a friction test was performed using a 0-mesh cloth, the friction coefficient was 0.17. In addition, the above roller was mounted on a printer cartridge, and the temperature was 40 ° C./humidity 95% RH.
When the cartridge was left for 2 weeks, no close contact with the OPC was observed. However, when an image was formed using the cartridge, one streak pattern was observed in the horizontal direction at the photoconductor cycle.

[0029]

As described above, according to the present invention,
The above-mentioned coating layer of the charging member consisting of the elastic layer and the coating layer formed on the surface thereof is obtained by adding a silicone oil having one or two reactive functional groups at one end and having active hydrogen at the end. Since it is made of a fluororesin, it is difficult to adhere to the member to be charged, and the friction between the member and the member to be charged can be reduced. Therefore, the contamination of the surface of the member to be charged caused by contact with the member to be charged such as a photoreceptor can be significantly reduced. Further, by using the charging member for a contact-type charging device, a charging device capable of obtaining a good image over a long period of time can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a charging member of the present invention.

FIG. 2 is a sectional view showing an example of the charging member of the present invention.

FIG. 3 is a diagram illustrating a method of measuring a friction coefficient of a charging member.

FIG. 4 is a diagram showing a schematic configuration of a charging device of the present invention.

[Explanation of symbols]

Reference Signs List 10 photosensitive drum, 20 charging roller, 21 shaft, 22 elastic layer, 23 coating layer, 30 voltage applying means.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H003 BB11 CC05 4J038 CD091 CD101 CD111 CD121 CD131 CE051 DG262 DL032 DL052 DL082 DL102 GA01 GA03 GA06 GA07 GA12 HA026 KA03 KA08 NA20 PB06 PC08

Claims (6)

[Claims] 1. A charging member that contacts an object to be charged and charges the object by applying a voltage between the object and the object to be charged. At least one coating layer formed on the outside, and the coating layer is formed by adding silicone oil having one or two reactive functional groups at one end to 100 parts by weight of a fluororesin. 0.05 to 30 parts by weight,
A charging member formed from a fluororesin having active hydrogen at its terminal. 2. The charging member according to claim 1, wherein the resin layer contains a bifunctional or more functional isocyanate crosslinking material. 3. The charging member according to claim 1, wherein the resin layer contains a conductive powder. 4. The elastic layer has a density of 0.05 to 0.9.
The charging member according to any one of claims 1 to 3, wherein the charging member is made of urethane foam having a g / cm < ³ >. 5. The resin layer according to claim 1, wherein the charging member has a thickness of 100 g.
100% cellulose, 30g when a load of f is applied
/ M ^3, 70 charging member according to any one of claims 1 to 4, the friction coefficient with respect to the fabric of the mesh, characterized in that not more than 0.4. 6. An object to be charged, a charging member for contacting the object to be charged and charging the object to be charged, and voltage applying means for applying a voltage between the charging member and the object to be charged. 2. The charging device according to claim 1, wherein the charging member is used as the charging member.
A charging device, comprising the charging member according to claim 5.