JP2002244402A - Electrifying member and image forming device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrifying member suitable for a close contact electrification system, and capable of preventing the fluctuation of an electrified potential, the dispersion of a resistance value, toner sticking and defective electrification due to the aforesaid factors, and also, whose resistance value is adjusted to be in an intermediate resistance area. SOLUTION: The electrifying roller 10 is constituted by forming a resistance regulating layer 12 of thermoplastic resin composition with high polymer ion conductive materials dispersed on a core bar 11, and the surface of the resistance regulating layer 12 is subjected to a hardened film coating with a hardening agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member such as a charging roller for charging a photosensitive member in an electrophotographic image forming apparatus such as a copying machine, a laser printer, a facsimile, and the like. The present invention relates to an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, as a charging member, for example, FIG.
The charging roller and the like in the electrophotographic image forming apparatus shown in FIG. The image forming apparatus 1 includes a charging roller 2, a power pack 3, a photosensitive drum 4, a surface voltmeter 5, a developing roller 6, a transfer roller 7, and a cleaning device 8.

The charging roller 2 receives power from a power pack 3 and charges the photosensitive drum 4. The photosensitive drum 4 is rotated in the direction of arrow A by a drive mechanism (not shown). The surface voltmeter 5 moves the charging roller 2 along the rotation direction.
And measures the potential of the surface 4 a of the photosensitive drum 4.

The developing roller 6 causes the toner to adhere to the charged photosensitive drum 4, and the transfer roller 7 transfers the toner attached to the photosensitive drum 4 to the recording paper S. The cleaning device 8 removes the toner remaining on the photosensitive drum 4 and cleans the photosensitive drum 4.

In the image forming process by the image forming apparatus 1, first, the surface 4 of the photosensitive drum 4 is charged by the charging roller 2.
a is charged to a negative high potential. Subsequently, the charged surface 4a is irradiated with an exposure L composed of reflected light from a document or laser light. This exposure L has a light quantity distribution corresponding to the black / white of the image to be formed, and the potential (negative potential) of each part of the surface 4a decreases in accordance with the amount of received light, so that the light quantity distribution on the surface 4a is reduced. , That is, the potential distribution corresponding to
An electrostatic latent image is formed.

When the photosensitive drum 4 rotates and the portion of the surface 4a where the electrostatic latent image is formed passes through the developing roller 6, toner corresponding to the potential distribution adheres to the surface 4a and the electrostatic latent image is formed. Are visualized as a toner image. This toner image is transferred onto a recording sheet S fed at a predetermined timing by a transfer roller 7.
The recording paper S is conveyed in the direction of arrow B toward a fixing unit (not shown).

On the other hand, the photoreceptor drum 4 after the transfer is cleaned by removing the toner remaining on the surface 4a by the cleaning device 8, and the residual charge is removed by a quenching lamp (not shown) to perform the next operation. The process proceeds to image processing.

[0008]

As a general charging method in the above-described image forming apparatus 1, there is a contact charging method in which the charging roller 2 is brought into contact with the photosensitive drum 4, and the contact charging method is as follows. There are the following issues.

[0009] The constituent material of the charging roller oozes out of the charging roller and adheres to the surface of the photosensitive drum, and as the adhesion proceeds, a trace of the charging roller remains on the surface of the photosensitive drum.

When an AC voltage is applied to the charging roller, the charging roller that is in contact with the photosensitive drum vibrates to generate a charging noise.

The toner on the surface of the photosensitive drum adheres to the charging roller, and the charging performance is reduced. In particular, when bleeding occurs on the charging roller, the toner is more likely to adhere.

If the photosensitive drum is not driven for a long time, the charging roller is permanently deformed.

In order to cope with such a problem, a proximity charging system has been devised in which the charging roller 2 is brought into close proximity to the photosensitive drum 4 instead of contacting it (see Japanese Patent Application Laid-Open No. 3-240076). In this proximity charging method, the closest distance between the charging roller 2 and the photosensitive drum 4 is 0.005 to 0.3 mm.
The photosensitive drum 4 is charged by applying a voltage to the charging roller 2 so that the photosensitive drum 4 is charged. In the proximity charging method, the charging roller 2 and the photosensitive drum 4 are not in contact with each other. Therefore, there are problems in the contact charging method, such as "adhesion of the constituent materials of the charging roller to the photosensitive drum" and "problem due to long-term non-use. "Permanent deformation of the charging roller" is not a problem. Regarding “the deterioration of the charging performance of the charging roller due to the adhesion of the toner”, the proximity charging method is superior because the amount of the toner adhering to the charging roller is reduced.

The required characteristics of the charging roller used in the proximity charging system are different from those of the charging roller used in the contact charging system. This is because, in the contact charging method, the charging roller needs to contact the photosensitive drum uniformly in order to uniformly charge the photosensitive drum. For this reason, the charging roller has an elastic body such as a vulcanized rubber around the cored bar. This is because such a charging roller has the following disadvantages when used in a proximity charging system.

In order to secure a certain gap between the charging roller and the photosensitive drum, it is necessary to provide a spacer or the like in a non-image area (an area not involved in image formation) at both axial ends of the charging roller. When the roller is made of an elastic material as described above, the charging roller is deformed when its spacers and the like are subjected to an external force (from the photosensitive drum). If the gap is not kept constant due to this deformation, the charging potential becomes unstable. And image unevenness resulting therefrom.

If the charging roller is made of vulcanized rubber, the charging roller may be deformed by its own weight and the gap may change, and the vulcanized rubber is liable to set or deform over time. There is also a concern that the above-mentioned void changes with time.

In order to cope with such a problem, it is conceivable to use a thermoplastic resin which is an inelastic material instead of vulcanized rubber or the like.

Here, it is known that the charging mechanism by the charging roller is a minute discharge according to Paschen's law between the charging roller and the photosensitive drum, and the surface of the photosensitive drum is maintained at a predetermined charging potential. In order to achieve this, the resistance value of the thermoplastic resin is set in a semiconductive region (10 ⁶ to 10 ⁹ Ω · c
m). As a method of adjusting the resistance value, a method of dispersing a conductive pigment such as carbon black in a thermoplastic resin is generally used. However, it is difficult to uniformly disperse the conductive pigment. Tends to increase,
Image defects due to partial charging failure are likely to occur.

On the other hand, as another method of adjusting the resistance value, there is a method of dispersing an ionic conductive agent (an electrolyte salt such as a Li salt) in a thermoplastic resin (see Japanese Patent Application Laid-Open No. 10-161397). Since the electrolyte salt is dispersed at the molecular level in the matrix resin, the dispersion of the resistance value is smaller than in the above-described method in which the conductive pigment is dispersed, and partial charging failure does not pose a problem in image quality. However, since the electrolyte salt has a property of easily bleeding out on the surface of the matrix resin, toner may be attached to the surface of the charging roller when bleeding out, which may cause an image defect.

In order to avoid such bleed-out, it is conceivable to use a nonionic polymer type conductive agent having a polyether group such as polyalkylene oxide. Since this conductive agent is a polymer, it is dispersed and fixed in the matrix resin, and bleed out to the surface of the charging roller hardly occurs. However, since the nonionic polymer type conductive agent alone has a resistance value of about 10 ⁸ to 10 ¹¹ Ω · cm, the effect of suppressing the resistance value is small compared to the electrolyte salt, and the medium resistance region required for the charging roller is small. (10 ⁶ ~
It is difficult to adjust to 10 ⁹ Ω · cm).

The present invention has been made in view of the above circumstances, and is suitable for a proximity charging method, and can prevent fluctuations in charging potential, variations in resistance value, adhesion of toner, and defective charging accompanying these. It is another object of the present invention to provide a charging member having a resistance value adjusted to a medium resistance region and an image forming apparatus having the charging member.

[0022]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to claim 1 provides a resistance adjusting layer made of a thermoplastic resin composition in which a polymer type ionic conductive material is dispersed on a conductive support. The charging member is formed and configured, and the surface of the resistance adjustment layer is subjected to a hardening treatment with a hardener.

According to the first aspect of the present invention, since the high-molecular ion conductive material is dispersed in the thermoplastic resin composition to form the resistance adjusting layer, fluctuations in charging potential and fluctuations in resistance are prevented. And the resistance adjustment layer can be easily made semiconductive (medium resistance region). Further, since the surface of the resistance adjusting layer is subjected to the cured coating treatment with the curing agent, it is possible to prevent the toner from adhering due to the bleed-out of the polymer-type ionic conductive material.

According to a second aspect of the present invention, in the charging member according to the first aspect, the curing agent contains an isocyanate-containing compound.

According to the second aspect of the present invention, since the isocyanate-containing compound which is easily cured is used as the curing agent, the charging member can be manufactured relatively easily at low cost.

According to a third aspect of the present invention, in the charging member according to the first aspect, the cured film treatment is an immersion treatment in which the resistance adjusting layer is immersed in a treatment solution containing an isocyanate-containing compound. I do.

According to the third aspect of the present invention, the isocyanate-containing compound which is easily cured is used as a curing agent, and the resistance adjusting layer is immersed in a treatment solution containing the curing agent to complete the cured film treatment. Therefore, a cured film having a small thickness and excellent charging characteristics can be easily formed, and the charging member can be manufactured relatively easily at low cost.

According to a fourth aspect of the present invention, in the charging member according to any one of the first to third aspects, the polymer-type ionic conductive material is a compound containing a quaternary ammonium base or a polyetheresteramide. It is a compound containing.

According to the fourth aspect of the present invention, since a compound containing a quaternary ammonium salt group or a compound containing a polyetheresteramide is used as the high-molecular-weight ionic conductive material, the resistance value of the medium resistance region required for the resistance adjusting layer can be improved. Can be easily obtained.

According to a fifth aspect of the present invention, in the charging member according to any one of the first to fourth aspects, the resistance adjusting layer is formed on the conductive support by injection molding or extrusion molding. It is characterized by having been done.

According to the fifth aspect of the present invention, since the resistance adjusting layer is formed on the conductive support by injection molding or extrusion molding, the thermoplastic resin composition (resistance adjusting layer) and the conductive support are Good adhesion can be easily secured.

According to a sixth aspect of the present invention, there is provided an image forming apparatus having the charging member according to any one of the first to fifth aspects.

According to the sixth aspect of the present invention, since the charging member according to any one of the first to fifth aspects is provided, the charging member has the effect of the invention according to any one of the first to fifth aspects. And images of excellent quality can be formed.

[0034]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a charging roller as a charging member according to the present invention. This charging roller 10 is the same as that shown in FIG.
1 is used in place of the charging roller 2 in the image forming apparatus 1 shown in FIG.
1 and a resistance adjusting layer 12 having a uniform thickness on the outer peripheral surface of the metal core 11.

The resistance adjusting layer 12 is formed of a thermoplastic resin composition in which a high molecular ion conductive agent is dispersed.
The volume resistivity value of the resistance adjusting layer 12 is 10 ⁶ to 10 ⁹
Ω · cm is desirable. Volume specific resistance value is 10
^If it exceeds ⁹ Ω · cm, the charge amount becomes insufficient,
Makes it impossible to obtain a sufficient charging potential to obtain an image without unevenness, while the volume resistivity value is 10 ⁶ Ω · c
This is because if it is smaller than m, leakage to the entire photosensitive drum 4 occurs.

The thermoplastic resin used for the resistance adjusting layer 12 is not particularly limited as long as it is an inelastic material.
Polyethylene (PE), polypropylene (PP), polymethyl methacrylate (PMMA), polystyrene (P
A general-purpose resin such as S) and a copolymer thereof (AS, ABS, etc.) is preferable because molding processing is easy.

As the high molecular weight ionic conductive agent dispersed in the thermoplastic resin, the resistance value of a single substance is 10 ⁶ to 10 ¹⁰ Ω.
A quaternary ammonium salt group-containing compound (preferably a quaternary ammonium salt group-containing polyolefin) or a polyetheresteramide-containing compound is used because the resin resistance is about cm and the resin resistance is easily lowered. In addition, as for the compounding amount, since the resistance value of the resistance adjusting layer 12 needs to be a desired value as described above, the compounding amount should be 30 to 50 parts by weight with respect to 100 parts by weight of the base material. Is preferred. Dispersion of this compound in a thermoplastic resin can be easily performed by using a means such as a biaxial kneader or a kneader, and the ionic conductive material is uniformly dispersed at a molecular level in a matrix polymer. Resistance adjustment layer 1
In No. 2, there is no variation in the resistance value due to poor dispersion of the conductive substance as seen in the resistance adjusting layer in which the conductive pigment is dispersed. In addition, since the above compound is a polymer, it is uniformly dispersed and fixed in the matrix polymer, and bleed-out hardly occurs.

The resistance adjusting layer 12 is formed on the metal core 11 by dispersing a semiconductive resin composition obtained by dispersing a compound containing a quaternary ammonium salt group or a compound containing a polyetheresteramide component in a thermoplastic resin. It can be easily performed by providing the core metal 11 on the peripheral surface of the core metal 11 by extrusion molding, injection molding, or the like, and coating the core metal 11 with the semiconductive resin composition. The surface of the resistance adjustment layer 12 thus formed may be cut or ground at any stage, whereby the surface accuracy required for the resistance adjustment layer 12 can be easily satisfied.

The surface of the resistance adjusting layer 12 is subjected to a hardening film treatment with a hardening agent. This cured film treatment is performed, for example, by immersing the resistance adjustment layer 12 in a treatment solution containing an isocyanate-containing compound, and may be performed by forming a cured treatment film layer on the surface of the resistance adjustment layer 12 again. Good.

Examples of the treatment solution containing an isocyanate-containing compound include a solution obtained by dissolving an isocyanate-containing compound in an organic solvent, a solution obtained by dissolving an isocyanate-containing compound and a polyol in an organic solvent, and a solution prepared by adding these solutions to a urethane-forming reaction. There are those to which auxiliary agents and the like used are added. Each processing solution may be further dispersed in water or another solvent.

Here, the isocyanate-containing compound includes:
An isocyanate compound, a silane compound having an isocyanate group, and a dimethylsiloxane compound having an isocyanate group are included. And, as the isocyanate compound, for example, diphenylmethane diisocyanate,
Examples include naphthalene diisocyanate, tolylene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, or prepolymers or modified products thereof.
On the other hand, as the polyol, polyester polyol,
Polyether polyol, polycarbonate polyol and the like can be mentioned. The auxiliary agent includes a chain extender, a crosslinking agent, and the like, and examples thereof include amines, glycols, hexanetriol, and trimethylolpropane.
The isocyanate-containing compound is preferably used by dissolving it in an aprotic polar organic solvent, particularly preferably ethyl acetate, dimethylformamide or a compound thereof.

The thickness of the cured film formed on the surface of the resistance adjusting layer 12 is not particularly limited, but is preferably about 1 to several tens μm. This is the resistance adjustment layer 1
In order to prevent bleed-out from 2, a thick film is more advantageous, but if the cured film is too thick, the photosensitive drum 4 cannot be sufficiently charged because the cured film is insulative. is there. Therefore, the use of an isocyanate-containing compound as a curing agent, which can effectively prevent bleed-out even when the thickness of the cured film is small,
Very informative.

[0044]

EXAMPLES Hereinafter, more specific examples of the charging roller according to the present invention (Examples 1 to 3) and examples of the charging roller manufactured for comparison (Comparative Examples 1 to 4) will be described. explain.

Example 1 8 m in diameter made of stainless steel
m, ABS resin (GR-150)
0, 100 parts by weight of Denki Kagaku Kogyo Co., Ltd.) and 30 parts by weight of an ion-conductive polymer compound containing a quaternary ammonium base (Leolex AS-1720, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) with 100 parts by weight. The composition (volume resistance value 1 × 10 ⁸ Ω · cm) was coated by injection molding to form a resistance adjusting layer 12.

Next, an isocyanate-containing compound (diphenylmethane diisocyanate, manufactured by Dainippon Ink and Chemicals, Inc.) was dissolved in methyl acetate to a weight concentration of 15% to prepare an ethyl acetate solution as a solution for treating a cured film. Resistance adjusting layer 1 formed above in this solution
2 was immersed for 15 seconds, dried at room temperature,
For 1 hour to complete the curing reaction of the isocyanate-containing compound on the surface of the resistance adjusting layer. Thereby, the diameter 12
mm of the charging roller 10 was obtained.

Example 2 After forming a resistance adjusting layer 12 in the same manner as in Example 1, an isocyanate-containing compound (hexamethylene diisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to methyl acetate so as to have a weight concentration of 15%. To prepare an ethyl acetate solution as a cured film treatment solution. Next, the resistance adjusting layer 12 formed above was immersed in this solution for 15 seconds, and dried at room temperature.
By heating at 0 ° C. for 1 hour, the curing reaction of the isocyanate-containing compound on the surface of the resistance adjusting layer was completed. Thus, a charging roller 10 having a diameter of 12 mm was obtained.

Example 3 8 m in diameter made of stainless steel
m, ABS resin (GR-150)
0, manufactured by Denki Kagaku Kogyo Co., Ltd.) and 100 parts by weight of an ionic conductive polymer compound containing a polyetheresteramide component (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) is mixed with 50 parts by weight. (Volume resistance value 1 × 10 ⁸ Ω · cm) was coated by injection molding to form a resistance adjusting layer 12.

Then, an isocyanate-containing compound (diphenylmethane diisocyanate, manufactured by Dainippon Ink and Chemicals, Inc.) was dissolved in methyl acetate to a weight concentration of 15% to prepare an ethyl acetate solution as a cured film treatment solution. Resistance adjusting layer 1 formed above in this solution
2 was immersed for 15 seconds, dried at room temperature,
For 1 hour to complete the curing reaction of the isocyanate-containing compound on the surface of the resistance adjusting layer. Thereby, the diameter 12
mm of the charging roller 10 was obtained.

[Comparative Example 1] 8 m in diameter made of stainless steel
A rubber composition (volume resistance value 3 × 10 ⁸ ) in which 100 parts by weight of epichlorohydrin rubber (Epichromer CG, manufactured by Daiso Co., Ltd.) and 3 parts by weight of ammonium perchlorate are blended on the peripheral surface of a metal core of m Ω · cm) through a vulcanization step and covered by extrusion molding to form a resistance adjusting layer.

Next, on the surface of the resistance adjusting layer, a polyvinyl butyral resin (Denka butyral 3000-K,
A protective layer was formed from a mixture of Denki Kagaku Kogyo Co., Ltd.), an isocyanate-based curing agent and tin oxide (60% by weight based on the total solid content) to obtain a charging roller having a diameter of 12 mm.

[Comparative Example 2] 8 m in diameter made of stainless steel
15 parts by weight of conductive carbon black (Ketjen Black EC, Ketjen Black International) per 100 parts by weight of ABS resin (GR-1500, manufactured by Denki Kagaku Kogyo Co., Ltd.) (Volume resistance value 4 × 10 ⁷ Ω · cm) was coated by injection molding to form a resistance adjusting layer.

Next, a protective layer was formed on the surface of the resistance adjusting layer with a mixture of a polyamide resin (Daiamide T-171, manufactured by Daicel Huls Co., Ltd.) and carbon black (10% by weight based on the total solid content). Thus, a charging roller having a diameter of 12 mm was obtained.

[Comparative Example 3] 8 m in diameter made of stainless steel
Composition containing 3 parts by weight of lithium perchlorate with respect to 100 parts by weight of ABS resin (GR-1500, manufactured by Denki Kagaku Kogyo Co., Ltd.)
× 10 ⁸ Ω · cm) by injection molding to form a resistance adjusting layer.

Then, a polyvinyl butyral resin (Denka butyral 3000-K,
A protective layer was formed from a mixture of Denki Kagaku Kogyo Co., Ltd.), an isocyanate-based curing agent and tin oxide (60% by weight based on the total solid content) to obtain a charging roller having a diameter of 12 mm.

[Comparative Example 4] 8 m in diameter made of stainless steel
On the peripheral surface of the m core metal, a polymer type nonionic conductive agent (Pelestat 6321, Sanyo Chemical Industry Co., Ltd.) 30 weight parts per 100 parts by weight of ABS resin (GR-1500, manufactured by Denki Kagaku Kogyo Co., Ltd.) The composition (volume resistance value 1 × 10 ¹¹ Ω · cm) obtained by mixing the parts was coated by injection molding to form a resistance adjusting layer.

Next, on the surface of the resistance adjusting layer, a polyvinyl butyral resin (Denka butyral 3000-K,
A protective layer was formed from a mixture of Denki Kagaku Kogyo Co., Ltd.), an isocyanate-based curing agent and tin oxide (60% by weight based on the total solid content) to obtain a charging roller having a diameter of 12 mm.

With respect to the charging rollers according to the above Examples and Comparative Examples, the charging potential of the photosensitive drum 4 was measured and the image was evaluated using the image forming apparatus 1 shown in FIG.
At this time, a spacer tape was adhered to the non-image areas at both ends in the axial direction of the charging roller, and the charging roller was installed so that the gap between the charging roller and the photosensitive drum 4 was 50 μm. Further, the voltage applied to the charging roller by the power pack 3 is set to DC = −800 V, AC = 2400 Vpp (frequency = 2 kHz), and voltage concentration on a defective portion (pinhole) of the photosensitive drum 4 and abnormal discharge (leak) occur. The presence or absence of the resulting abnormal image was evaluated.

Further, continuous printing (continuous copying) is performed by the image forming apparatus 1 in which each charging roller is set, and 10
Evaluation of toner adhesion and image evaluation on the surface of the charging roller after passing 000 sheets was performed. Table 1 shows the above measurement and evaluation results.

[0060]

[Table 1]

As can be seen from the measurement and evaluation results,
Charging roller 10 according to any one of Embodiments 1 to 3
Satisfies the performance of all items without a variation width of the charged potential, without an abnormal image due to image unevenness or leak, adhesion of toner after continuous copying and image unevenness.

On the other hand, the charging roller according to Comparative Example 1 has a large variation width of the charging potential, and has a problem with image unevenness and toner adhesion.

The charging roller according to Comparative Example 2 has a problem that the variation width of the charging potential is large and an abnormal image due to image unevenness or leak is observed.

The charging roller according to Comparative Example 3 has a relatively large variation range of the charging potential, and has a problem in performance (toner adhesion and image unevenness) after continuous copying.

The charging roller according to Comparative Example 4 has a problem with respect to image unevenness, though the variation width of the charging potential is acceptable.

In Table 1, the comprehensive evaluation is shown as "O" only when the performance of all items is satisfied, and the overall evaluation is shown as "X" when none of the performances is satisfied.

[0067]

As described above, according to the first aspect of the present invention, since the polymer type ion conductive material is dispersed in the thermoplastic resin composition to form the resistance adjusting layer, the charging potential can be reduced. It is possible to prevent fluctuations and variations in the resistance value, and easily make the resistance adjustment layer semiconductive (medium resistance region). Further, since the surface of the resistance adjusting layer is subjected to the cured coating treatment with the curing agent, it is possible to prevent the toner from adhering due to the bleed-out of the polymer-type ionic conductive material.

According to the second aspect of the present invention, since the isocyanate-containing compound which is easily cured is used as the curing agent, the charging member can be manufactured relatively easily at low cost.

According to the third aspect of the present invention, the isocyanate-containing compound which is easily cured is used as a curing agent, and the resistance adjusting layer is immersed in a treatment solution containing the curing agent to complete the cured film treatment. Therefore, a cured film having a small thickness and excellent charging characteristics can be easily formed, and the charging member can be manufactured relatively easily at low cost.

According to the fourth aspect of the present invention, since the compound containing a quaternary ammonium base or the compound containing a polyetheresteramide is used as the high-molecular-weight ionic conductive material, the resistance value of the medium resistance region required for the resistance adjusting layer is determined. Can be easily obtained.

According to the fifth aspect of the present invention, since the resistance adjusting layer is formed on the conductive support by injection molding or extrusion molding, the thermoplastic resin composition (resistance adjusting layer) and the conductive support are Good adhesion can be easily secured.

According to the sixth aspect of the invention, since the charging member according to any one of the first to fifth aspects is provided, the charging member has the effect of the invention according to any one of the first to fifth aspects. And images of excellent quality can be formed.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a charging roller according to the present invention.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of an image forming apparatus having a charging roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Photoreceptor drum 10 Charging roller (charging member) 11 Metal core (conductive support) 12 Resistance adjustment layer L Exposure S Recording paper

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H200 FA18 HA02 HB12 HB22 HB45 HB46 MA01 MA04 MA11 MA17 MB01 MB06 3J103 AA02 AA14 AA33 EA02 EA03 EA20 FA07 FA10 FA14 FA15 FA18 GA02 GA52 GA57 GA58 GA60 HA03 HA04 HA05 HA15 HA20 HA33 HA33

Claims (6)

[Claims] 1. A resistance adjusting layer comprising a thermoplastic resin composition in which a polymer type ionic conductive material is dispersed is formed on a conductive support, and the surface of the resistance adjusting layer is cured by a hardener to form a cured coating. A charging member characterized in that: 2. The charging member according to claim 1, wherein the curing agent contains an isocyanate-containing compound. 3. The charging member according to claim 1, wherein the cured film treatment is an immersion treatment in which the resistance adjusting layer is immersed in a treatment solution containing an isocyanate-containing compound. 4. The charging device according to claim 1, wherein the high molecular ion conductive material is a compound containing a quaternary ammonium salt group or a compound containing a polyetheresteramide. Element. 5. The charging member according to claim 1, wherein said resistance adjusting layer is formed on said conductive support by injection molding or extrusion molding. . 6. An image forming apparatus comprising the charging member according to claim 1. Description: