JPH11316486A - Electrifying member, image forming device and intermediate transfer body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable good electrification of a body to be electrified such as a photoreceptor, without causing the peeling of a protective layer or the like due to the driving of the photoreceptor in a high-temperature high-humidity environment even when a water-based resin is used as a material for the protective layer or a resistor layer. SOLUTION: An electrifying roller 10, on a conductive supporting body 11 which also acts as a feeder electrode, is formed by providing an elastic layer 12, a resistor layer 13 made of a water-based material and a protective layer 14 made of a water-based material successively. The rate of change of the volume of the material due to the absorption of water accompanied with the environmental changes from 23 deg.C temperature and 50% relative humidity to 40 deg.C temperature and 95% relative humidity is larger in the protective layer 14 than the material of the resistor layer 13 directly under the layer 14 and the difference value between the volume change rates is made to be equal to or less than <=2.5%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member which is used in an image forming apparatus such as a copying machine or a printer and which is charged by contacting an image carrier, an image forming apparatus, and an intermediate transfer member.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, as a charging device for performing a primary charging process of a photosensitive member as an image carrier, a high voltage is applied to a wire to generate a corona discharge, and the corona is applied to the wire. Corona chargers that expose a member to be charged have been widely used.

In recent years, the development of a contact charging type charging device, that is, a charging device in which a charging member is arranged in contact with a member to be charged and a voltage is applied thereto to charge the surface of the member to be charged has been developed. Contact charging is advantageous in that compared to corona charging, which is a non-contact type, the applied voltage required to obtain a desired potential on the surface of the member to be charged is low, and the amount of ozone generated during charging is small. In particular, a roller charging method using a conductive roller as a charging member is preferable in terms of charging stability, and is widely used.

FIGS. 11 and 12 show an example of a charging roller as a charging member in a conventional electrophotographic image forming apparatus.

The charging member 1 includes a conductive shaft 2 also serving as a power supply electrode, an elastic layer 3, a resistance layer 4, and a protective layer 5. Examples of the resin for the elastic layer 3 include solid rubber such as styrene-butadiene rubber (SBR), isoprene rubber, and silicone rubber. By dispersing a conductive agent such as carbon black or metal powder in these resins,
It has conductivity.

[0006] The resistance layer 4 is a layer provided for imparting an appropriate resistance to the charging member 1. Examples of the material include acrylic resin, hydrin rubber, urethane, and silicone rubber. By dispersing an appropriate amount of a conductive agent such as metal powder, appropriate conductivity can be imparted.

The protective layer 5 is provided to ensure the surface properties of the charging member 1 and to prevent the surface of the photoconductor from being contaminated by the material of the resistance layer 4. Examples of the material include an acrylic resin, a nylon-based synthetic resin material such as N-methoxymethylated nylon, and an acrylic modified urethane.

At this time, the protective layer 5 must not disturb the resistance imparted evenly by the resistive layer 4, but if the protective layer 5 is made conductive, a low level of pinholes or the like may occur on the surface of the photoreceptor. When a resistance portion is generated, a leak is likely to occur, so that it is necessary to have the same resistance as the resistance layer. That is, the protective layer 5 must be a uniform material with no resistance unevenness, and have good dispersibility of the conductive agent.

The purpose of ensuring the surface properties of the charging member by the protective layer 5 is to prevent resistance unevenness caused by contamination of the charging member due to durability. Therefore, for the purpose of lowering the surface energy of the protective layer 5, it has been studied to disperse a material containing fluorine (for example, ethylene tetrafluoride powder) in the material of the protective layer 5.

In order to satisfy these strict conditions and obtain a protective layer 5 having good surface properties and no resistance unevenness, at present,
A layer made of a coating material in which a material resin, a conductive agent, a material containing fluorine, and the like are dispersed in an organic solvent is formed on the resistance layer 4,
The protective layer 5 is obtained by air-drying at a low temperature of about ℃ or less.

It is known that when such a material is dried at a high temperature of 120 ° C. or more, wrinkles and cracks are formed on the surface, and the surface property is impaired. In addition, when drying is performed at a high temperature, the base layer and the like are deformed by heat, and the surface properties may be impaired. Therefore, it is preferable that the resistance layer is also formed by air drying at a low temperature.

Further, in recent years, a charging member using a water-based resin instead of a conventional organic solvent-soluble resin as a material for the resistance layer 4 and the protective layer 5 has been devised. This is the elastic layer 3
When an organic solvent-soluble resin is used to form the resistive layer 4 thereon, it is to prevent the organic solvent from swelling the elastic layer 3 as a foam and impairing the surface smoothness.

The use of an aqueous resin eliminates the need for an organic solvent, is advantageous in terms of cost, and has advantages such as easy management and handling.

[0014]

However, when a water-based material is used, the charging member 1 sticks to the image carrier in a high temperature and high humidity environment when the charging member 1 is actually used. When the image carrier is driven, the protective layer 5
It has been found that a phenomenon (hereinafter referred to as “scraping”) in which the particles are peeled easily occurs.

The following mechanism is considered as a cause of peeling.

Since the material of the protective layer 5 is water-based, in a high-temperature and high-humidity environment, the material of the protective layer 5 absorbs moisture and adheres to the image carrier side, thereby forming the protective layer 5 of the charging member 1 and the image carrier. Sticking occurs between them.

In particular, when dew condensation occurs on the surface of the charging member 1 and the image carrier and the dew surfaces contact each other, moisture is trapped in the contact nip portion between the charging member 1 and the image carrier, and It has been found that the adhesion between the image carrier and the protective layer 5 of the charging member 1 becomes particularly large because the image carrier is easily welded.

Further, when the swelling ratios of the protective layer 5 and the resistance layer 4 are different, a shear force is applied to the interface between the protection layer 5 and the resistance layer 4. Due to this shearing force, the adhesive force between the resistance layer 4 and the protective layer 5, which had been bonded with a strong force immediately after manufacturing, was weakened.
When sticking occurs between the protective layer 5 and the image carrier, only the protective layer 5 easily remains on the image carrier side, and peeling occurs.

The magnitude of the shearing force between the protective layer 5 and the resistance layer 4 depends on the material of the protection layer 5 and the material of the resistance layer 4 when the charging member 1 is brought from a normal environment to a high temperature and high humidity environment. Depends on the difference in the swelling ratio. That is, when the swelling ratio of the resistance layer 4 is extremely small, a large shearing force is applied even if the swelling ratio of the protective layer 5 is relatively low.

When peeling occurs, the charging member 1
In the portion where the material of the protective layer 5 adheres to the surface of the image carrier,
The toner image cannot be satisfactorily formed, and appears as an abnormal image.

In addition, in a portion where the protective layer 5 is peeled off on the charging member 1, since the resistance of the charging member 1 is different from other portions, charging unevenness occurs and appears as an abnormal image.

If the protective layer 5 is lost, if this portion is left in contact with the image carrier again, the surface of the image carrier may be further contaminated.

It is an object of the present invention to provide a charging member which can use a paint using water as a dispersion medium of a resin material, an image forming apparatus and an intermediate transfer member using the same.

It is another object of the present invention to provide a charging member which does not cause peeling of the surface layer even when the surface layer swells due to moisture absorption, an image forming apparatus using the same, and an intermediate transfer member.

Still another object of the present invention is to provide a conductive substrate to which a voltage is applied, a first resin layer, and a second resin layer provided on the first resin layer. A resin layer and the second resin layer are coated with a coating material in which a resin material is dispersed in an aqueous medium,
An object of the present invention is to provide a charging member formed by drying.

[0026]

The above object is achieved by a charging member, an image forming apparatus and an intermediate transfer member according to the present invention. In summary, the present invention includes a conductive substrate to which a voltage is applied, a first resin layer, and a second resin layer provided on the first resin layer, wherein the first resin layer The second resin layer is a charging member characterized by being formed by applying and drying a paint in which a resin is dispersed in an aqueous medium.

According to the present invention, the second resin layer is a surface layer that comes into contact with the member to be charged. The second resin layer has a fluorine resin. The first resin layer has an acrylic resin.
The drying temperature of the second resin layer is 120 ° C. or less. The charging member further has an elastic layer between the conductive substrate and the first resin layer. Difference in volume change rate between a material forming the first resin layer and a material forming the second resin layer due to an environmental change from a temperature of 23 ° C. and a relative humidity of 50% to a temperature of 40 ° C. and a relative humidity of 95%. Is 2.5% or less. The charging member has a roller shape. The charging member is a charging roller that charges the photoconductor. The charging member is a transfer roller that transfers a toner image to a transfer material. The first resin layer is thicker than the second resin layer and has a lower resistance value.

Further, the present invention provides a photosensitive member, a charging member which contacts the surface of the photosensitive member and charges the photosensitive member, and an electrostatic image formed by imagewise exposing the charged photosensitive member. Developing means for developing, wherein the charging member includes a conductive base to which a voltage is applied, a first resin layer,
A second resin layer provided on the resin layer, wherein the first resin layer and the second resin layer are formed by applying and drying a paint in which a resin is dispersed in an aqueous medium; An image forming apparatus.

According to the present invention, the photosensitive member has an organic photosensitive layer. The photosensitive member and the charging member constitute a process cartridge configured as an integrated unit that can be attached to and detached from the apparatus main body.

Further, the present invention relates to an intermediate transfer member in an intermediate transfer type image forming apparatus, wherein the intermediate transfer member includes a conductive base to which a voltage is applied, a first resin layer, and a first resin layer. And a second resin layer provided on the first substrate.
The intermediate transfer member is characterized in that the resin layer and the second resin layer are formed by applying and drying a coating material in which a resin is dispersed in an aqueous medium.

[0031]

Embodiments of the present invention will be described below in more detail with reference to the drawings.

Embodiment 1 FIG. 1 is a sectional view showing a charging member according to a first embodiment of the present invention. In this embodiment, the charging member 10 has a roller shape, that is, a charging roller.

In FIG. 1, reference numeral 11 denotes a shaft-shaped conductive support made of metal or plastic which also serves as a power supply electrode. The charging roller 10 includes a conductive elastic layer 12, a resistance layer 13 having a resistance higher than the elastic layer 12, and a protective layer 14 having a resistance higher than the resistance layer 13 on a conductive support 11. 14 mm.

In this embodiment, a urethane sponge foam is used as the elastic layer 12. A metal oxide is added to the foam as a conductive agent for imparting conductivity.

The resistance layer 13 is prepared by adding carbon to a dispersion of an aqueous acrylic resin and a butyral resin, stirring and dispersing the dispersion to about 300 μm by dipping.
And dried in an environment at a temperature of 100 ° C. for 5 to 6 hours.

As the protective layer 14, a dispersion of PTFE (polytetrafluoroethylene), a vinylidene emulsion and a butyral resin, which are water-based fluorocarbon resins to which carbon is added, is formed to a thickness of about 10 μm by dipping. In addition, the temperature is 100 ° C
Drying is carried out by leaving in the environment for 5 to 6 hours. The drying temperature of this protective layer, particularly the protective layer and the resistance layer, is preferably 120 ° C. or less.

As described above, by forming both the protective layer and the resistance layer by applying a coating material in which a resin material is dispersed in an aqueous medium and drying the coating, the difference in the swelling ratio between the protective layer and the resistance layer can be reduced. it can.

Next, an experimental example in which the swelling ratio of the protective layer and the resistance layer is changed will be described.

(Experimental Example 1) The charging roller 10 described above was used in this experiment. FIG. 2 shows the resistance layer 13 of the charging roller 10,
The swelling ratio of the material of the protective layer 14 is shown.

Here, the swelling ratio refers to a volume change rate when a material alone is brought from an environment at a temperature of 23 ° C. and a relative humidity of 50% to an environment at a temperature of 40 ° C. and a relative humidity of 95%.
A higher swelling ratio indicates a greater degree of wetting due to the material absorbing water.

As shown in FIG. 2, the resistance layer 13, the protection layer 1
In all cases, the swelling ratio started to rise immediately after standing,
Saturation is reached in about 20 hours.

According to FIG. 2, the swelling ratio of the resistance layer 13 is about 1.2% at the maximum. The maximum swelling ratio of the protective layer 14 is about 2.8%, and the difference is about 1.6%.

FIG. 3 is a sectional view showing a photosensitive drum as an image carrier in this experimental example.

The photosensitive drum 40 has an undercoat layer 42 on an aluminum cylinder 41 having a diameter of 30 mm, a charge generation layer 43 on the undercoat layer, and a charge transport using bisphenol Z type polycarbonate resin as a resin on the charge generation layer. Layer 4
And 4 having an organic photoreceptor layer.

The charging roller 10 is connected to the photosensitive drum 40
Then, as shown in FIG. 4, a load was applied to both ends of the charging roller 10 by a spring 52 using a charging roller terminal 51. At this time, the load of the charging roller terminal 51 on one side is 700
g weight, and a total load of 1400 g weight was applied to the charging roller 10.

As described above, when the charging roller 10 is in contact with the photosensitive drum 40, the temperature is 40 ° C. and the relative humidity is 95%.
After leaving in the environment for one month, no peeling occurred and no particular problem occurred on the image.

Further, when the charging roller 10 and the photosensitive drum 40 are dew-condensed, and the dew surfaces are in contact with each other, the charging roller 10 and the photosensitive drum 40 are left in an environment of 32.5 ° C. and a relative humidity of 80% for 2 weeks. Protective layer 14 of roller 10
And the photosensitive drum 40 were in close contact with each other, but could be easily peeled off, and no peeling occurred.

(Experimental Example 2) In this experimental example, the charging member was the same as the charging roller 10 in Experimental Example 1. Resistance layer 13
Was the same as in Experimental Example 1.

The material of the protective layer 14 is different from the material of the protective layer in that the amount of butyral resin is set to 1.5 times that of the experimental example 1. Other conditions are the same as those in Experimental Example 1.

FIG. 5 is a graph showing the transition of the swelling ratio of the resistance layer 13 and the protective layer 14 in this experimental example.

As shown in the figure, the swelling ratio of the resistance layer 13 is 1.2%,
The swelling ratio of the protective layer 14 is 3.2%. Therefore, the difference between the swelling ratio of the protective layer 14 and the resistance layer 13 is 2.0%.

The charging roller 10 was brought into contact with the photosensitive drum 40 in the same manner as in Experimental Example 1, and the temperature was 40 ° C. and the relative humidity was 95%.
When the charging roller 10 was left in the environment for one month, the charging roller 10 was in close contact with the photosensitive drum 40. However, when the photosensitive drum 40 was rotated by hand, the charging roller 10 could be easily rotated. Was.

Further, the charging roller 10 and the photosensitive drum 40 are dew-condensed, and the dew surface is brought into contact with the dew surface. Then, the charging roller 10 is left in an environment of 32.5 ° C. and 80% relative humidity for 2 weeks. 10 and the photosensitive drum 40 adhered firmly, but the photosensitive drum 40 could be rotated by hand. At this time, slight peeling of the protective layer occurred at the end of the photosensitive drum 40, but since it was outside the image area,
No image defects occurred, and no other problems occurred.

(Experiment 3) In this experiment, the charging roller 10 was used as the charging member in the same manner as in Experiment 1.

The resistive layer 1 of the charging roller 10 according to this experimental example
3 used the same thing as Experimental example 1. In addition, the protective layer 1
As No. 4, the amount of butyral resin was 2 in the material of Experimental Example 1.
The one that is doubled is used. Other conditions are the same as those in Experimental Example 1.

FIG. 6 is a graph showing the transition of the swelling ratio of the resistance layer 13 and the protective layer 14 in this experimental example.

As can be seen from the figure, at this time, the resistance layer 1
3 has a swelling rate of 1.2%, and the protective layer 14 has a swelling rate of 3.7%.
And the difference was 2.5%.

The charging roller 10 was brought into contact with the photosensitive drum 40 in the same manner as in Experimental Example 1, and the temperature was 40 ° C. and the relative humidity was 95%.
When the charging roller 10 was left in the environment for one month, the charging roller 10 was firmly adhered to the photosensitive drum 40, but the photosensitive drum 40 could be rotated by hand, and there was no particular abnormality on the image.

Further, the charging roller 10 and the photosensitive drum 40 are dew-condensed, and the dew surface is brought into contact with the condensing roller. Then, the charging roller 10 is left in an environment of 32.5 ° C. and 80% relative humidity for 2 weeks. 10 and the photosensitive drum 40 adhered firmly, but the photosensitive drum 40 could be rotated by hand. At this time, slight peeling of the protective layer occurred at the end of the photosensitive drum 40, but since it was outside the image area,
No image defects occurred, and no other problems occurred.

(Experimental Example 4) This experimental example is a comparative example.

The amount of butyral resin in the material of the protective layer 14 was doubled while the material of the resistance layer 13 and the drying conditions in Experimental Example 1 were kept as they were. The drying temperature was 75 ° C.

At this time, the protective layer 14 of the charging roller 10
FIG. 7 shows the transition of the swelling ratio of the material. As shown in the figure,
The maximum swelling ratio is about 3.8%. Therefore, the difference in the swelling ratio between the material of the resistance layer 13 and the material of the protective layer 14 is as follows.
It is about 2.6%.

The charging roller 10 was brought into contact with the photosensitive drum 40 in the same manner as in Experimental Example 1, and the temperature was 40 ° C. and the relative humidity was 95%.
When left in the environment for one month, the charging roller 10 and the photosensitive drum 40 adhered to each other, and it was difficult to rotate the photosensitive drum 40 by hand.

Further, the charging roller 10 and the photosensitive drum 40 are dew-condensed, and the dew surface is brought into contact with the condensing roller, and then left for two weeks in an environment at a temperature of 32.5 ° C. and a relative humidity of 80%. Although a very small part of the portion, peeling occurred, and in a portion where the components of the protective layer 14 adhered to the photosensitive drum 40, an image was not formed, and a phenomenon that the image was whitened out occurred. This is because the swelling ratio of the protective layer 14 is larger than the swelling ratio of the resistance layer 13,
This is because a shearing force acts between the protective layer 14 and the protective layer 14, and the protective layer 14 is easily peeled off from the resistance layer 13.

(Experiment 5) This experiment also shows a comparative example. A material obtained by removing butyral resin from the material of the resistance layer 13 of the charging roller 10 used in Experimental Example 4 is used. The same material as that of Experimental Example 1 was used for the material of the protective layer 14.

FIG. 8 shows the transition of the swelling ratio of the protective layer 14 of the charging roller 10 in this experimental example.

According to the figure, the swelling ratio of the resistance layer of the charging roller in this experimental example is 0.1% at the maximum, and the swelling ratio of the protective layer is about 2.8% at the maximum. Therefore, the resistance layer 13 and the protection layer 1
The difference in the swelling ratio from that of No. 4 is about 2.7%.

The charging roller 10 was brought into contact with the photosensitive drum 40 in the same manner as in Experimental Example 1, and the temperature was 40 ° C. and the relative humidity was 95%.
When the charging roller 10 and the photosensitive drum 40 came into close contact with each other after being left in the environment for one month, and were peeled off, the charging roller protection layer 14 was linearly formed along the contact nip between the charging roller 10 and the photosensitive drum 40. It was peeled off and adhered to the photosensitive drum 40.

This is because the charging roller protection layer 14 and the resistance layer 1
3, the resistance layer 13 and the protective layer 14
When the protective layer 14 is in close contact with the photosensitive drum, the holding force between the resistance layer 13 and the protective layer 14 does not work, and the protective layer 14 is peeled off. .

The dew condensation test in this test example was omitted because the protective layer 14 had already peeled off.

The results of Experimental Examples 1 to 5 are summarized in the following table.

[0072]

[Table 1] From these results, it is understood that if the difference between the swelling ratios of the resistance layer 13 and the protective layer 14 is within 2.5%, a charging roller having no practical problem can be formed.

As described above, the difference in swelling ratio can be reduced by using an aqueous resin for the resistance layer in addition to the protective layer, but the difference in swelling ratio is more preferably 2.5% or less. .

Embodiment 2 Another embodiment of the present invention will be described. The present embodiment is characterized in that a blade-shaped member is used in the same material configuration as in the first embodiment.

As shown in FIG. 9, the charging blade 100
Is a conductive support 101 made of metal or plastic, also serving as a power supply electrode, a base material 102 of urethane foam,
It comprises a resistance layer 103 and a protection layer 104. Resistance layer 103,
The material, forming conditions, and the like of the protective layer 104 are the same as those of the resistance layer 13 and the protective layer 14 of the charging roller 10 in the first embodiment.

The charging blade 100 is fixed by fixing members (not shown) at both ends in the longitudinal direction of the support 101, thereby ensuring an appropriate nip width and a contact pressure with the photosensitive drum 40. Charging blade 10
0 is adjusted and fixed so that the linear pressure is 43 gf / cm.

The charging blade 100 was brought into contact with the photosensitive drum 40 in the same manner as in the first embodiment and left for one month in an environment at a temperature of 40 ° C. and a relative humidity of 95%. No adhesion occurred, and no abnormality occurred on the image.

Further, when both the charging blade 100 and the photosensitive drum 40 are dew-condensed and the dew surface is brought into contact, the charging blade 100 is left in an environment of 32.5 ° C. and a relative humidity of 80% for 2 weeks. Although slight sticking occurred between the photosensitive drum 100 and the photosensitive drum 40, the protective layer 104 did not peel off, and no particular abnormality was observed on the image.

Embodiment 3 Still another embodiment of the present invention will be described.

In this embodiment, the charging member of the present invention is
It is characterized in that it is configured as a process cartridge of an image forming apparatus, which is incorporated in an integral housing together with functional components such as a photosensitive drum, a cleaning device, and a developing device.

FIG. 10 shows a process cartridge 110 in this embodiment. As the charging member in this embodiment, the same charging roller 10 as in the first embodiment was used. The configuration of the photosensitive drum 40 as an image carrier is also the same as in the first embodiment.

The developing device 111 includes a developing sleeve 112,
It is composed of a developing blade 113. Developing sleeve 11
The toner 114 held on the developing blade 113
Is regulated to a certain thickness. Developing sleeve 112
Is applied with a power supply (not shown), and the toner on the developing sleeve 112 flies toward the photosensitive drum 40, and selectively and electrostatically adheres to the electrostatic latent image formed on the photosensitive drum 40. As a result, a toner image is formed.

The cleaning device 115 comprises a cleaning blade 116 and a waste toner container 117. The residual toner that is not transferred after the image formation is scraped off by the cleaning blade 116 of the cleaning device 115 and collected in the waste toner container 117.

The photosensitive drum 40 and the charging member 10 are assembled together with the developing device 111 and the cleaning device 115 in an integral housing 118, and are configured as a process cartridge 110 which is detachably mountable to an image forming apparatus (not shown).

In the process cartridge 110,
As in the case of the first embodiment, the charging roller 10 receives a load of a total pressure of 1400 g at both ends by the charging roller terminal 51 and the spring 52.

When the process cartridge 110 is set
When left for one month in an environment of 0 ° C. and a relative humidity of 95%, no close contact occurred between the photosensitive drum 40 and the charging roller 10,
No abnormalities occurred on the image.

Further, the charging roller 10 and the photosensitive drum 40 are dew-condensed, and are left in an environment of a temperature of 32.5 ° C. and a relative humidity of 80% for two weeks in a state where the dew surfaces are in contact with each other. Although slight adhesion was observed between the photosensitive drum 40 and the photosensitive drum 40, no peeling occurred and no particular abnormality occurred on the image.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications within the technical concept of the present invention are possible.

For example, in the above-described embodiment, the primary charging member for uniformly charging the photosensitive drum for performing exposure has been described. However, other charging members formed on the photosensitive drum may be used. The present invention may be applied to a transfer member that applies a charge for transferring a toner image to a transfer material to the transfer material. Various shapes such as a roller shape, a belt shape, and a blade shape can be considered.

Further, in the color image forming apparatus, the present invention is applied to an intermediate transfer body for temporarily carrying a toner image to form a plurality of color toner images and then performing collective transfer to a transfer material. You may. In this case, the intermediate transfer member may have various shapes such as a drum shape and a belt shape.

[0091]

As described above, according to the present invention,
By applying a voltage between the member and the member to be charged by contacting the member, the surface layer of the charging member having a plurality of structures for charging the member is formed from a material containing an aqueous resin. , Relative humidity 50% to temperature 40 ° C, relative humidity 9
The volume change rate (swelling rate) due to water absorption accompanying the environmental change to 5% is greater than the material forming the surface layer above the material forming the surface layer, and the difference in the volume change rate is 2.5%. As described below, even if an aqueous material is used for the surface layer, the protective layer or the like is not peeled off by driving the photoreceptor in a high-temperature and high-humidity environment, and the object to be charged such as the photoreceptor can be satisfactorily charged. Thus, it is possible to form a high-quality image.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a charging roller according to a first embodiment of the present invention.

FIG. 2 is a graph showing changes in the swelling ratio of a resistance layer and a protective layer of the charging roller according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a photosensitive drum.

FIG. 4 is a diagram illustrating a contact state between a charging roller and a photosensitive drum.

FIG. 5 is a graph showing changes in the swelling ratio of the resistance layer and the protective layer of the charging roller in Experimental Example 2 of the present invention.

FIG. 6 is a graph showing changes in the swelling ratio of the resistance layer and the protective layer of the charging roller in Experimental Example 3 of the present invention.

FIG. 7 is a graph showing changes in the swelling ratio of the resistance layer and the protective layer of the charging roller in Experimental Example 4 of the present invention.

FIG. 8 is a graph showing changes in the swelling ratio of the resistance layer and the protective layer of the charging roller in Experimental Example 5 of the present invention.

FIG. 9 is a sectional view showing a charging blade according to a second embodiment of the present invention.

FIG. 10 is a sectional view showing a process cartridge according to a third embodiment of the present invention.

FIG. 11 is a sectional view showing a conventional charging roller.

FIG. 12 is a perspective view showing a conventional charging roller.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 charging roller 11 support 12 elastic layer 13 resistive layer 14 protective layer 40 photosensitive drum 100 charging blade 103 resistive layer 104 protective layer 110 process cartridge

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Sunahara Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo

Claims (32)

[Claims] A first resin layer; and a second resin layer provided on the first resin layer, wherein the first resin layer and the second resin layer are connected to each other. A charging member, wherein the resin layer is formed by applying a coating material in which a resin is dispersed in an aqueous medium and drying the coating. 2. The charging member according to claim 1, wherein the second resin layer is a surface layer that contacts a member to be charged. 3. The charging member according to claim 2, wherein said second resin layer comprises a fluorine resin. 4. The charging member according to claim 3, wherein said first resin layer comprises an acrylic resin. 5. The charging member according to claim 2, wherein the drying temperature of the second resin layer is 120 ° C. or less. 6. The charging member according to claim 1, wherein said charging member further has an elastic layer between said conductive base and said first resin layer. 7. A temperature of 23 ° C. and a relative humidity of 5 ° C. between a material forming the first resin layer and a material forming the second resin layer.
2. The charging member according to claim 1, wherein a difference in a volume change rate according to an environmental change from 0% to a temperature of 40 ° C. and a relative humidity of 95% is 2.5% or less. 8. The charging member according to claim 1, wherein the charging member has a roller shape.
Charging member. 9. The charging member according to claim 8, wherein said charging member is a charging roller for charging a photosensitive member. 10. The charging member according to claim 8, wherein said charging member is a transfer roller for transferring a toner image to a transfer material. 11. The charging member according to claim 1, wherein the first resin layer is thicker than the second resin layer and has a lower resistance value. 12. A photoconductor, a charging member that contacts the surface of the photoconductor and charges the photoconductor, and a developing unit that develops an electrostatic image formed by exposing the charged photoconductor to an image. The charging member comprises: a conductive base material to which a voltage is applied;
A resin layer, and a second resin layer provided on the first resin layer, wherein the first resin layer and the second resin layer are formed by applying and drying a paint in which a resin is dispersed in an aqueous medium. An image forming apparatus, comprising: 13. The image forming apparatus according to claim 12, wherein said photosensitive member has an organic photosensitive layer. 14. The image forming apparatus according to claim 12, wherein the photosensitive member and the charging member form a process cartridge configured as an integrated unit that can be attached to and detached from the apparatus main body. 15. The image forming apparatus according to claim 12, wherein said second resin layer is a surface layer in contact with said photoconductor. 16. The image forming apparatus according to claim 12, wherein said second resin layer comprises a fluororesin. 17. The image forming apparatus according to claim 16, wherein said first resin layer comprises an acrylic resin. 18. The drying temperature of the second resin layer is 120 ° C.
The image forming apparatus according to claim 15, wherein: 19. The image forming apparatus according to claim 12, wherein said charging member further has an elastic layer between said conductive base and said first resin layer. 20. An environment change of a material forming the first resin layer and a material forming the second resin layer from a temperature of 23 ° C. and a relative humidity of 50% to a temperature of 40 ° C. and a relative humidity of 95%. 2. The method according to claim 1, wherein the difference in the volume change rate is 2.5% or less.
2 image forming apparatus. 21. The image forming apparatus according to claim 12, wherein said charging member has a roller shape. 22. The image forming apparatus according to claim 12, wherein said first resin layer is thicker than said second resin layer and has a lower resistance value. 23. An intermediate transfer member in an intermediate transfer type image forming apparatus, wherein the intermediate transfer member is provided on a conductive base to which a voltage is applied, a first resin layer, and the first resin layer. An intermediate transfer member having a second resin layer, wherein the first resin layer and the second resin layer are formed by applying and drying a paint in which a resin is dispersed in an aqueous medium. 24. The intermediate transfer member according to claim 23, wherein said second resin layer is a surface layer in contact with said photoconductor. 25. The intermediate transfer member according to claim 23, wherein said second resin layer comprises a fluororesin. 26. The intermediate transfer member according to claim 25, wherein the first resin layer includes an acrylic resin. 27. The drying temperature of the second resin layer is 120 ° C.
The intermediate transfer member according to claim 24, wherein: 28. The intermediate transfer member according to claim 23, wherein the charging member further has an elastic layer between the conductive substrate and the first resin layer. 29. A change in the environment of the material forming the first resin layer and the material forming the second resin layer from a temperature of 23 ° C. and a relative humidity of 50% to a temperature of 40 ° C. and a relative humidity of 95%. 3. The difference in volume change rate is 2.5% or less.
3. Intermediate transfer member. 30. The intermediate transfer member according to claim 23, wherein the intermediate transfer member has a drum shape. 31. The intermediate transfer member according to claim 23, wherein the intermediate transfer member has a belt shape. 32. The intermediate transfer member according to claim 23, wherein the first resin layer is thicker than the second resin layer and has a lower resistance value.