JP2002318485A - Electrostatic charging member and electrostatic charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charging member which makes it possible to obtain good image quality with a copying machine, printer, etc., is hardly tightly adherable to a photoreceptor, is small in friction, obviates the adhesion of toners and is excellent in electrostatic charge characteristics and electrostatic charge environmental stability and an electrostatic charging device using this electrostatic charging member. SOLUTION: The electrostatic charging member is composed of an elastic layer and a resin layer. The extreme surface layer of this resin layer is formed of a resin containing 1 to 80 wt.% fluorine-containing acrylic monomer, more preferably such a urethane denatured acrylic resin that the acrylic resin components are contained at 5 to 80 wt.% and 1 to 100 wt.% acrylic monomer among the acrylic resin components contains fluorine.

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 an object to be charged such as a photosensitive member used in an electrostatic latent image process in a copying machine, a printer, or the like, and a charging member provided with the charging member. It concerns the 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 toner to the latent image, forming a toner image by the adhesion of 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 photoreceptor 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 form a resin layer by applying a resin solution of polyethylene, epoxy, polyester, polyether, polystyrene, phenol, polyamide, urethane-modified acrylic, or the like by dipping or spraying. In particular, the urethane-modified acrylic resin described above is excellent in charging characteristics and charging environment stability, and further has such characteristics that there is no variation in charging performance in manufacturing, as already described in JP-A-7-31493. This is introduced in Japanese Patent Application Laid-Open No. Hei 8-21696.
In addition, since this resin has a urethane portion, it has characteristics such as high elasticity and coating film strength, and is excellent in reversion to deformation.

[0003]

However, in this charging contact system, the resin contacts the photosensitive member for a long time, causing close contact with the photosensitive member. May be peeled off and the surface of the photoreceptor may be contaminated. Also, depending on the strength of the adhesion, poor charging due to the adhesion of the toner to the charging member may occur, or friction between the photosensitive member and the toner may cause toner fusion or scraping of the photosensitive member, resulting in image defects. In some cases. Therefore, it is required that the coating film used for the charging member has low adhesion / adhesion to the photoreceptor and low toner adhesion. As a remedy, the urethane prepolymer in the main chain contains silicone, and the side chain has a molecular weight of 200 to 50.
A method has been proposed in which a silicone component is contained in a urethane-modified acrylic resin by a prescription such as grafting of 000 polysiloxane-containing acrylic. However, according to this method, although the adhesiveness / frictional property to the photoreceptor is improved, the effect on the toner adhesion is not so significant.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional problems, and is capable of obtaining good image quality in a copying machine, a printer, and the like. It is an object of the present invention to provide a charging member which is free from adhesion and has excellent charging characteristics and charging environment stability, and 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 the charging member is composed of an elastic layer and a resin layer, and the outermost layer in the resin layer is 0.05 to 0.05. 8
A resin containing 0% by weight of a fluorine-containing acrylic monomer, in particular, an acrylic resin component is contained in an amount of 5 to 80% by weight, and 1 to 100% by weight of the acrylic resin component contains fluorine. The present inventors have found that the above object can be achieved by forming a resin layer formed of a urethane-modified acrylic resin, and have reached the present invention. That is, the invention described in claim 1 is:
A charging member that contacts the member to be charged, applies a voltage between the member to be charged, and charges the member to be charged, an elastic layer,
And at least one resin layer formed outside the elastic layer.
It is characterized by being formed from a resin containing 80% by weight of a fluorine-containing acrylic monomer, which makes it difficult to adhere to a member to be charged, has low friction, and has no toner adhesion. It is possible to obtain a charging member having excellent environmental stability.

According to a second aspect of the present invention, the acrylic resin component contains 5-80% by weight of the resin, and the acrylic monomer accounts for 1-100% by weight of the acrylic resin component to contain fluorine. It is characterized by comprising a urethane-modified acrylic resin as described above. The invention described in claim 3 is characterized in that the resin contains 1 to 60% by weight of a silicone component. The invention according to claim 4 is characterized in that the resin layer contains an isocyanate crosslinking agent having two or more functional groups. According to a fifth aspect of the present invention, the resin layer contains a conductive powder. The invention according to claim 6 is characterized in that the elastic layer is made of urethane foam having a density of 0.05 to 0.9 g / cm ³ . The charging member according to claim 7, when applying a load of 100gf to the charging member, cellulose ^{100%, 30g / m 3,} 70
The friction coefficient of the resin layer with respect to the mesh cloth is 1.0 or less.

[0008] The invention according to claim 8 is an object of the present invention is to provide a member to be charged, a charging member which contacts the member to be charged and charges the member to be charged, and a member between the charging member and the member 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 7 is used, whereby toner adhesion and deterioration of the surface of the member to be charged can be prevented. , It is possible to obtain good image quality.

[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 resin layer, and an elastic body is used as the elastic layer. For example, as a roll-shaped charging member, FIGS. 1 (a) and 1 (b)
As shown in FIG. 1, a metal or plastic shaft 21 and an elastic layer 2 formed on the outer periphery of the shaft 21 are provided.
2 and a resin roller 23 formed on the surface of the elastic layer 22 and made of a resin to which a conductive agent is added. The resin layer 23 is
For example, as shown in FIG. 2, a two-layer structure including a surface layer 23A forming the surface of the charging roller 20 and an intermediate layer 23B formed between the surface layer 23A and the elastic layer 22 may be used. It may be composed of three or more layers.

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 Although a composition is illustrated, polyurethane is particularly preferable, and a 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 this elastic layer by adding a conductive agent such as an ionic conductive agent or 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.

The resin 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 resin used as the outermost layer, that is, the surface layer, acrylic, urethane, nylon, polyethylene,
Examples include resins such as epoxy, polyester, polyether, polystyrene, phenol, polyamide, and urethane-modified acrylic. These resins and fluorine-containing acrylic monomers are grafted, copolymerized, or bonded by using a formula such as bonding using an active hydrogen group and an isocyanate group. By forming a resin layer to be a surface layer by using the above, the above-described effects of reducing friction, preventing adhesion, and reducing toner adhesion can be obtained. Examples of the fluorine-containing acrylic monomer include perfluorooctylethyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, and trifluoroethyl methacrylate. And a fluorine-modified acrylate in which a fluoroalkyl group or the like is bonded to a methacrylate terminal.

A urethane-modified acrylic resin is preferably used as the resin. The urethane-modified acrylic resin of the present invention is effective in chemically bonding the urethane resin and the acrylic resin component from the viewpoint of compatibility, liquid stability, film flexibility, and the like. Reaction of a polymer having a hydroxyl group introduced into an acrylic polymer with β-hydroxyethyl methacrylate or the like and a urethane polymer having an isocyanate group at a molecular terminal, or
(A; acrylic acid, acrylic acid ester monomer or oligomer) by reacting an acrylic component having a hydroxyl group at a molecular terminal (one or both terminals) as shown in (1) with a urethane prepolymer.

Embedded image In the polymer thus obtained, the urethane chain and the acrylic chain may be bonded to each other in a block type or may be bonded in a graft type. In addition, a urethane prepolymer serving as a main chain is produced using several kinds of polyols and a bifunctional isocyanate (for example, HDI), and a mercapto group is contained in a side chain portion of the urethane prepolymer, and an acrylic monomer is used. A method of combining with a radical accelerator, grafting an acrylic monomer to the urethane portion, or simultaneously polymerizing the acrylic monomer to synthesize the acrylic monomer is also often used.

The method for synthesizing the urethane-modified acrylic resin of the present invention is not limited to the above method.
In addition, it can also be obtained by a method of adding isocyanate to an acrylic diol mixed system, a method of adding a terminal isocyanate polyester or a terminal isocyanate polyether to an acrylic monomer, and polymerizing the urethane acrylate. As the acrylic resin component used in the synthesis, those having a glass transition temperature Tg as a polymer from room temperature to 80 ° C. are preferable. In addition to the above β-hydroxyethyl methacrylate, for example, ethyl methacrylate, isobutyl methacrylate, Those containing glycidyl methacrylate or the like are used. At this time, the composition of the acrylic resin component in the urethane-modified acrylic resin is preferably 5 to 80% by weight, particularly preferably 10 to 60% by weight, and more preferably 20 to 50% by weight.

Further, from the viewpoint of improving the adhesion to the photoreceptor,
A silicone component can be included in the urethane-modified acrylic resin. Specifically, for example, a method of synthesizing by reacting a urethane prepolymer and an acrylic component using a polyol containing a silicone chain as a raw material can be considered. In this case, the composition of the silicone component in the urethane prepolymer is 2 to 80% by weight, particularly 5 to 50% by weight.
% By weight. The composition of the silicone component in the urethane-modified acrylic resin after the reaction is preferably 1 to 50% by weight, particularly preferably 3 to 30% by weight. Alternatively, a polysiloxane having a molecular weight of 200 to 50,000 may be grafted to the side chain of the urethane prepolymer. In this case, as the composition of the silicone component in the urethane-modified acrylic resin,
The content is preferably 2 to 50% by weight, particularly preferably 5 to 20% by weight, and if contained excessively, the resin solution becomes cloudy.

Further, by grafting a fluorine-containing acrylic resin to these urethane-modified acrylic resins,
A fluorine-containing urethane-modified acrylic resin may be generated and used as a resin for forming a resin layer serving as a surface layer. The fluorine content at this time depends on the acrylic content in the urethane-modified acrylic resin, and the fluorine-containing acrylic is desirably 90% or less, preferably 80% or less, based on the entire acrylic part. In such a case, the resin solution becomes cloudy or the glass transition temperature Tg cannot be adjusted.

The urethane-modified acrylic resin such as the above-mentioned fluorine-containing urethane-modified acrylic resin may be contained alone in the surface layer of the charging member, or may be contained in two or more kinds. You may use it. In this case, examples of the resin other than the urethane-modified acrylic resin include polyester, phenol resin, polyamide, epoxy resin, urea resin, urethane resin and the like. In some cases, the surface properties can be improved by adding an external additive such as a release agent to the surface layer. 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 5 to 20 μm. If it exceeds 30 μm, the surface layer becomes hard and the flexibility of the resin layer is impaired.

The urethane-modified acrylic resin preferably contains an active hydrogen group at the terminal or side chain of the resin and is crosslinked with a polyisocyanate compound or the like.
The polyisocyanate compound added as the cross-linking agent is a compound having two or more isocyanate groups in a molecule, and the same polyisocyanate generally used as a raw material for producing polyurethane can be used. Specifically, tolylene diisocyanate (TD
I), diphenylmethane diisocyanate (MDI),
Naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IP
DI), phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), cyclohexane diisocyanate, lysine ester triisocyanate, undecane triisocyanate, hexamethylene triisocyanate, triphenylmethane triisocyanate, and the Polymers, derivatives, modified products, hydrogenated products and the like can be mentioned. Among them, particularly preferred are aliphatic or alicyclic isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and polymers, derivatives and modified products thereof because of their excellent ozone resistance and heat resistance.

The method of forming the resin layer is not particularly limited, but a method of preparing a paint containing each component forming each layer and applying the paint by dipping or spraying is preferably used. . The fluorine-containing urethane-modified acrylic resin used in the outermost layer in the resin layer of the present invention may be either a water-based solvent or a solvent-based solvent.
From the viewpoint of uniform charging and stabilizing the production, it is preferable to sandwich one or more aqueous resins between the elastic layer and the elastic layer. The water-based resin may be of any type as long as the solvent is water, and includes a water-soluble type, an emulsion type and a suspension type. In particular, a resin having an active hydrogen such as a carboxyl group, a hydroxyl group or an amino group is preferably used. . Examples thereof include polyester-based, acrylic-based, urethane-based, hot-water-soluble systems such as polydioxolane, and the like. 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, and the charging noise is improved. In particular, among the acrylic resins, the glass transition temperature Tg is -50 ° C or more and 10 ° C or less, and the content of carboxyl groups and hydroxyl groups is 2%.
Up to 5% by weight, 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 layer has 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
About 20% by weight.

In any structure, the resistance suitable for the charging member of the present invention is preferably such that the volume resistivity is from 10 ² to 10 ¹² Ω · cm, especially from 10 ⁵ to obtain good images. It is preferably 10 to 10 ¹⁰ Ω · cm. Also, if the surface of the charging member produced as described above has irregularities, the toner is clogged and causes an image defect, so the surface is preferably as smooth as possible,
Specifically, the JIS ten-point average roughness Rz is 4 μm or less,
Further, it is preferably 3 μm or less, particularly preferably 2 μm or less.

In the charging member formed by the above method, a load of 100 gf was applied to the charging member to
When the coefficient of friction of the resin layer with respect to a cloth of 00%, 30 g / m ³ and 70 mesh was measured, the coefficient of friction was 1.0%.
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 10 is used as a mating material for friction.
The reason why the cloth of 0%, 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, FIG.
As shown in FIG. 5, the charging roller 20 serving as the charging member of the present invention is driven to rotate while being in contact with the photosensitive drum 10 serving as a charged member, and the voltage applying means 30 causes the photosensitive drum 10 to move between the photosensitive drum 10 and the charging roller 20. A charging device configured to charge the photosensitive drum 10 by applying a DC voltage or a voltage obtained by superimposing an AC voltage on the DC 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.

When the charging member formed by the above method was used in the above-described charging device, toner adhesion was small, and there was no significant difference in glossiness before and after image output. The surface gloss was measured using a surface gloss meter “Haze-Gloss Meter” manufactured by Big Gardner.
Was measured by the following measurement method. First,
The charging member is installed at the measurement port of the above-mentioned device so that the uppermost surface of the charging member is the measurement surface. Here, when the charging member has a roller shape, the roller is adjusted to a length of 10 cm, and the roller is fixed to a black fixing base that can be fitted according to the roller diameter. Then, the incident light angle 85 ° (measurement area 8
(mm × 60 mm). In this case, the measured value is obtained as a value when the reflection index 1.567 of the black glass standard plate according to DIN 67530 is set to 100.

<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 resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer B having a thickness of 10 μm was further formed thereon to prepare a charging roller. . The resin 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. The resin layer B is made of a urethane-modified acrylic resin (glass transition temperature Tg) in which the acrylic component is 50% by weight and the fluorine-containing acrylic monomer accounts for 40% by weight of the total acrylic monomer.
= 27 ° C) was dissolved in a MEK solvent and an isocyanate crosslinking agent was added. The surface roughness of the above roller is JIS
The ten-point average roughness Rz was 0.8 μm. 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 0.43. . When the above roller was mounted on a printer cartridge and left at a temperature of 40 ° C./95% RH for 2 weeks, no close contact with OPC was observed. When an image was formed using the cartridge, a good image was obtained. Furthermore, even if continuous 8000 images are output,
No image deterioration was observed. In addition, before and after image output,
The surface gloss at a roller incident angle of 85 ° was measured. As a result, it was confirmed that the value was 49.5 before the image was output, but was 49.3 after the image was output, which was almost unchanged.

Example 2 A resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer C having a thickness of 10 μm was further formed thereon. Was prepared. The resin layer A was formed by applying a paint obtained by adding carbon to a water-based acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The resin layer C
A urethane-modified acrylic resin (Tg) in which the acrylic component is 50% by weight and the fluorine-containing acrylic monomer accounts for 30% by weight of the total acrylic monomer
= 80 ° C) in a MEK solvent and added with an isocyanate crosslinking agent. The surface roughness of the above roller is JIS
The ten-point average roughness Rz was 0.7 μm. This roller was subjected to a friction test using a cloth of 100% cellulose, 30 g / m ³ , and 70 mesh at a temperature of 22 ° C./humidity of 50% RH, and the friction coefficient was 0.30.
Also, the above roller is attached to the printer cartridge,
When 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. Furthermore, no image deterioration was observed even after 8,000 continuous images were output. In addition, when the surface glossiness at a roller incident angle of 85 ° before and after image output was measured,
While it was 57.0 before the image was displayed, it was confirmed that there was almost no change to 56.1 after the image was output.

Example 3 A resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer D having a thickness of 10 μm was further formed thereon. Was prepared. The resin layer A was formed by applying a paint in which carbon was added to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The resin layer D
The acrylic component is 50% by weight, and the fluorine-containing acrylic monomer is 20% of the total acrylic monomer.
The urethane-modified acrylic resin (Tg = 27 ° C.), in which the siloxane-containing acrylic monomer occupies 20% by weight and the siloxane-containing acrylic monomer, respectively, was dissolved in a MEK solvent and an isocyanate crosslinking agent was added. The surface roughness of the roller was 0.9 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 0.31. Further, when the 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 OPC was observed. When an image was formed using the cartridge, a good image was obtained. Furthermore, no image deterioration was observed even after 8,000 continuous images were output. Also, the surface gloss before and after image output was measured at a roller incident angle of 85 °. The result was 54.5 before image output and 53.2 after image output, showing little change. Was confirmed.

Comparative Example 1 A resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer E having a thickness of 10 μm was further formed thereon. Was prepared. The resin layer A was formed by applying a paint in which carbon was added to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The resin layer E is
A urethane-modified acrylic resin (Tg = 27 ° C.) whose acrylic component is 50% by weight and whose acrylic monomer does not contain fluorine or silicone is dissolved in a MEK solvent, and an isocyanate crosslinking agent is added. 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 2.5. Further, the above-mentioned roller is mounted on a printer cartridge, and the temperature is 40 ° C./humidity 95%.
When left at 2% RH for 2 weeks, adhesion with 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. The surface gloss before and after image output was measured at a roller incident angle of 85 °. The surface gloss before image output was 51.0, and the surface gloss after image output was 27.9. Dropped.

Comparative Example 2 A resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer F having a thickness of 10 μm was further formed thereon. Was prepared. The resin layer A was formed by applying a paint in which carbon was added to an aqueous acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The resin layer F
A urethane-modified acrylic resin (Tg = 80 ° C.) in which the acrylic component is 50% by weight and the acrylic monomer does not contain fluorine or silicone is dissolved in a MEK solvent, and an isocyanate crosslinking agent is added. The surface roughness of the roller is JIS ten point average roughness Rz, 0.8
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 1.1. Further, the above-mentioned roller is mounted on a printer cartridge, and the temperature is 40 ° C./humidity 95%.
When left at 2% RH for 2 weeks, adhesion with OPC occurred. Further, when an image was formed using the cartridge, one streak pattern was observed in the horizontal direction at the photoconductor cycle. The surface gloss before and after image output was measured at a roller incident angle of 85 °. The surface gloss before image output was 57.0, but after the image output was 44.5, the surface gloss decreased. .

Comparative Example 3 A resin layer A having a thickness of 100 μm was formed on the surface of an elastic layer made of conductive urethane foam, and a resin layer G having a thickness of 10 μm was further formed thereon. Was prepared. The resin layer A was formed by applying a paint obtained by adding carbon to a water-based acrylic resin, and the volume resistivity was adjusted to 5 × 10 ⁷ Ω · cm. The resin layer G is
The acrylic component is 50% by weight, and the total acryl monomer contains 4% of siloxane-containing
A urethane-modified acrylic resin (Tg = 27 ° C.) occupying 0% by weight was dissolved in a MEK solvent, and an isocyanate crosslinking agent was 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 under the conditions of a temperature of 22 ° C. and a humidity of 50% RH.
49. Further, when the above roller was attached to a printer cartridge and left at a temperature of 40 ° C./95% RH for 2 weeks, no close contact with the OPC was observed. However, when 8,000 images were continuously output, 5
From about 000 sheets, the image started to be fogged. The surface gloss before and after image output was measured at a roller incident angle of 85 °. As a result, the surface gloss was 54.0 before image output and 40.3 after image output. .

[0031]

As described above, according to the present invention,
The charging member is composed of an elastic layer and a resin layer,
The resin layer is formed of a resin containing 0.05 to 80% by weight of a fluorine-containing acrylic monomer, in particular, an acrylic resin component of 5%.
Since the resin layer is formed from a urethane-modified acrylic resin in which the acrylic monomer contains fluorine in an amount of 1 to 100% by weight of the acrylic resin component, the adhesive layer adheres to the member to be charged. Hard to do, and
It is possible to obtain a charging member having a small friction and no toner adhesion and having excellent charging characteristics and charging environment stability. 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 a configuration example of a charging member of the present invention.

FIG. 2 is a cross-sectional view showing one configuration 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 resin layer, 30 voltage applying means.

Claims (8)

[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. A charging member comprising: at least one resin layer formed on the outside; and wherein the resin layer is formed from a resin containing 0.05 to 80% by weight of a fluorine-containing acrylic monomer. 2. The resin according to claim 1, wherein the acrylic resin component is 5 to 8
2. The charging device according to claim 1, wherein the urethane-modified acrylic resin contains 0% by weight and 1 to 100% by weight of the acrylic resin component contains fluorine. 3. Element. 3. The resin according to claim 1, wherein the silicone component is 1 to 60.
The charging member according to claim 1, wherein the charging member is contained by weight%. 4. The charging member according to claim 1, wherein the resin layer contains a bifunctional or more isocyanate crosslinking agent. 5. The charging member according to claim 1, wherein the resin layer contains a conductive powder. 6. The elastic layer having a density of 0.05 to 0.9.
The charging member according to any one of claims 1 to 5, characterized in that consisted urethane foam is g / cm ^3. 7. The resin layer has a thickness of 100 g on the charging member.
100% cellulose, 30g when a load of f is applied
/ M ^3, 70 charging member according to any one of claims 1 to 6, the friction coefficient with respect to the fabric of the mesh, characterized in that less than 1.0. 8. 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 using the charging member according to claim 7.