JP2000047496A - Intermediate transfer member and image forming device with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer member used for an electrophotographic image forming device, preventing the fixation of a toner and having improved durability by setting the surface hardness of the intermediate transfer member to a specific value or below in the universal hardness at the depth corresponding to the average grain size of the toner used for forming a toner image. SOLUTION: This intermediate transfer member is arranged between an image forming body and a recording medium, temporarily holds the transfer record of a toner image formed on the surface of the image forming body on its surface, and transfers it to a recording medium. The surface hardness of the intermediate transfer member is set to 80 N/mm2 or below in the universal hardness at the depth corresponding to the average grain size of the toner used for forming the toner image. When the universal hardness exceeds 80 N/mm2, the fixation preventing effect of the toner is not fully exerted, the universal hardness in the range of 0.1-80 N/mm2 is preferable in view of the fixation preventing effect of the toner, and the range of 1-30 N/mm2 is particularly preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate transfer member and an image forming apparatus using the same. For more information,
The present invention relates to an intermediate transfer member used in an electrophotographic image forming apparatus such as a copying machine, a facsimile, a laser printer, and the like, in which toner is prevented from sticking to improve the durability, and an image forming apparatus equipped with the intermediate transfer member. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a printer, first, the surface of a photosensitive member (image forming member) is uniformly charged by a charging roller or the like. An electrostatic latent image is formed by projecting an image and erasing the charge of the light-exposed portion. Then, toner is supplied to the electrostatic latent image by a developing roller or the like, and the toner image is formed by electrostatic adhesion of the toner. Is formed, transferred to a recording medium such as paper by a transfer roller or the like, and further heated and fixed by a fixing roller or the like to obtain a print image. In this case, a color printer or a color copier basically performs printing in accordance with the above process, but in the case of color printing, the color tone is reproduced using magenta, yellow, cyan, and black toners. Therefore, a process for obtaining a desired color tone by superposing these toners at a predetermined ratio is required, and several methods have been proposed for performing this process. First, similarly to the case of performing monochrome printing, when the electrostatic latent image is visualized by supplying the toner on the photoconductor, the toners of the four colors of magenta, yellow, cyan, and black are sequentially applied. There is a multi-developing method in which development is performed by superimposing, and a color toner image is formed on a photoconductor. In this system, the device can be constructed relatively compact, but there is a problem in that it is very difficult to control the gradation and high image quality cannot be obtained.

Secondly, by providing four photoconductors and developing the latent images of the respective photoconductors with magenta, yellow, cyan, and black toners, respectively, a magenta toner image, a yellow toner image, and a cyan toner Forming four toner images of an image and a toner image of black,
There is a tandem system that reproduces a color image by arranging the photoconductors on which these toner images are formed in one line, sequentially transferring each toner image to a recording medium such as paper, and superimposing the toner images on the recording medium. However, in this method, although a good image can be obtained, the four photoconductors, and a charging mechanism and a developing mechanism provided for each photoconductor are arranged in a line, so that the apparatus becomes large and expensive. I can't help but becoming something. Third, a recording medium such as paper is wound around a transfer drum and rotated four times, and magenta, yellow, cyan, and black on a photoreceptor are sequentially transferred to the recording medium for each rotation to reproduce a color image. There is also a method. However, according to this method, a relatively high image quality can be obtained. However, when the recording medium is thick paper such as a postcard, it is difficult to wind the recording medium around the transfer drum, and the type of recording medium is limited. There is a problem.

In contrast to the multiple developing system, the tandem system and the transfer drum system, excellent image quality can be obtained, the apparatus is not particularly enlarged, and the type of recording medium is particularly limited. As a method without such a problem, an intermediate transfer method has been proposed. In this intermediate transfer method, an intermediate transfer member including a drum and a belt for temporarily transferring and holding a toner image on a photoconductor is provided, and four color toner images on the photoconductor, that is, a magenta toner image, a yellow toner image, and a cyan toner image are provided. The color image is formed on the intermediate transfer member by sequentially transferring the toner image of the black toner image and the toner image of black on the intermediate transfer member, and the color image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the four color toner images, it is possible to obtain high image quality, and it is not necessary to arrange the photoconductors in a line as in the tandem method. In particular, there is no need to increase the size of the recording medium, and there is no need to wind the recording medium around the drum, so that the type of the recording medium is not limited.

However, in such an intermediate transfer system, durability tends to be a problem because the intermediate transfer member contacts the photosensitive member, the secondary transfer member, the cleaning member, and the like. It is known that the durability is greatly affected by residual toner. That is, the toner primarily transferred from the photoconductor and held on the surface of the intermediate transfer member should be secondarily transferred to a recording medium such as paper in the following process. However, in practice, due to the secondary transfer failure and further the cleaning failure, a part of the toner remains on the intermediate transfer member, and is gradually embedded and fixed on the surface of the intermediate transfer member. It begins to accumulate and begins to appear in the image as a defect. Basically, the fundamental measure is to improve the transfer efficiency and the cleaning efficiency so that the toner does not remain on the intermediate transfer member. However, it is difficult to eliminate 100% of the residual toner with the current technology. Therefore, in order to prevent the residual toner from sticking to the surface of the intermediate transfer member, it has been attempted to coat the surface of the intermediate transfer member with a fluorine-based material having excellent antifouling properties, but there are some effects. However, at present, sufficient durability has not been obtained.

[0006]

Under such circumstances, the present invention is used in an electrophotographic image forming apparatus such as a copying machine, a facsimile, a laser printer, etc., and improves the durability by preventing toner from sticking. It is an object of the present invention to provide an intermediate transfer member having the above configuration, and an image forming apparatus equipped with the intermediate transfer member.

[0007]

The inventors of the present invention have conducted intensive studies to develop an intermediate transfer member having improved durability by preventing toner sticking. Focusing on the fact that a hardness at a desired depth can be obtained in an extremely shallow range of the member surface, and that when the toner is fixed by biting, a concave portion is formed on the member surface by the average particle diameter of the toner. It has been found that, by optimizing the universal hardness at the same depth as the average particle diameter, it is possible to effectively prevent the toner from sticking due to biting. Even when the average particle diameter of the toner to be used is unknown, the universal hardness at a depth of 7 μm, which is the average particle diameter of a general toner, is optimized, so that the toner adhesion preventing effect sufficient for practical use is obtained. I found that I can get it.

The present invention has been completed based on such findings. That is, the present invention provides an intermediate transfer device that is disposed between an image forming body and a recording medium, temporarily transfers and holds the toner image formed on the surface of the image forming body to the surface, and transfers this to a recording medium. The member is characterized in that the surface hardness of the member is 80 N / mm ² or less as a universal hardness at a depth corresponding to the average particle diameter of the toner used for forming the toner image or at a depth of 7 μm. An intermediate transfer member is provided. The present invention also provides an image forming apparatus provided with the above-mentioned intermediate transfer member.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An intermediate transfer member according to the present invention is disposed between an image forming body and a recording medium, and temporarily transfers, records and holds a toner image formed on the surface of the image forming body,
It has a function of transferring this to a recording medium. In the intermediate transfer member of the present invention, the surface hardness is defined by a universal hardness as shown below. The universal hardness is obtained by pushing the indenter into a measurement object while applying a load to the formula (I). ) Universal hardness = [test load] / [contact surface area of indenter with test object under test load] (I), and the unit is expressed in N / mm ² . The measurement of the universal hardness can be performed using a commercially available hardness measuring device, for example, an ultra-micro hardness meter H-100V
(Manufactured by Fisher Co.) or the like. In this measuring device, a quadrangular pyramid or triangular pyramid-shaped indenter is pressed into the object under test load, and the indenter comes into contact with the object from the depth at which the desired depth is reached. The universal hardness is calculated from the above formula (I).

In the intermediate transfer member of the present invention, the universal hardness at a depth corresponding to the average particle diameter of the toner used to form a toner image on the surface of the image forming body is 80 N / mm ² or less. This universal hardness is 8
If it exceeds 0 N / mm ² , the effect of preventing the toner from being fixed is not sufficiently exhibited, and the object of the present invention cannot be achieved. The universal hardness is 0.1 to 80 from the viewpoint of an effect of preventing toner from sticking.
The range of N / mm ² is preferable, and especially 1 to 30 N / mm ²
Is preferable. Specifically, if the average particle diameter of the toner used in the image forming apparatus using the intermediate transfer member of the present invention is 5 μm, the universal at the time when the indenter of the measuring device is pushed 5 μm from the surface of the intermediate transfer member. The hardness is adjusted to the above range. Further, in the present invention, when the average particle size of the toner used in the image forming apparatus using the intermediate transfer member is unknown, the universal hardness at 7 μm, which is the average particle size of a general toner, is set to the above value. Adjustment within the range can provide a practically sufficient effect.

The conditions for measuring the universal hardness are not particularly limited, and any conditions may be used as long as the universal hardness can be determined based on the indentation depth.
For example, when measuring the universal hardness using the ultra-micro hardness tester H-100V (manufactured by Fischer),
The following conditions can be exemplified, and the indenter is gradually pushed into the intermediate transfer member to a predetermined indentation depth under the following conditions, and the contact area between the load and the indenter when the indentation depth reaches a desired depth. From this, the universal hardness can be determined. Measurement condition example Indenter: square pyramid diamond indenter with facing angle of 136 degrees Initial load: 0.02 mN Maximum load: 5 to 400 mN Increase time from initial load to maximum load: 10 to 60 seconds The intermediate transfer member of the present invention is as described above. Any material may be used as long as it has a universal hardness. However, due to the electrostatic action of temporarily transferring and holding the toner image on its surface and transferring the toner image to a recording medium, the volume specific resistance of the member is 10 ³ to 10 ¹⁶ Ω · cm. Is particularly preferable, and a range of 10 ⁸ to 10 ¹⁶ Ω · cm is particularly preferable.

The shape of the intermediate transfer member of the present invention is not particularly limited as long as it has the above-mentioned universal hardness. For example, a drum shape and a belt shape can be preferably mentioned. FIGS. 1 and 2 are schematic views of an example of a color image forming apparatus using the intermediate transfer member of the present invention in a drum shape and a belt shape, respectively. In each of the drawings, reference numeral 1 denotes a drum-shaped photoconductor, which rotates in the direction of an arrow. The photoreceptor 1 is charged by the primary charger 2, and then the image exposure 3 forms an electrostatic latent image corresponding to the first color component. Next, the image is developed with the first color magenta toner M by the developing device 41. The intermediate transfer member 20a or 20b rotates at the same peripheral speed as the photoconductor 1 in the direction of the arrow. In the nip portion between the photoconductor 1 and the intermediate transfer member 20a or 20b, the intermediate transfer member 20a or 20b
b, the toner image on the photoreceptor 1 is changed by the primary transfer bias applied from the power supply 61 to the intermediate transfer member 20a or 20b.
Is transferred to the outer peripheral surface of. After the transfer, the surface of the photoconductor 1 is cleaned by the cleaning device 14. Developing units 42-4
4 is sequentially used, and the same operation is repeated thereafter. The second color cyan toner image, the third color yellow toner image, the fourth color
The black toner images of the colors are sequentially superimposed and transferred onto the intermediate transfer member 20a or 20b, and a composite color toner image corresponding to the target color image is formed.

Next, a transfer roller 25 is brought into contact with the intermediate transfer member 20a or 20b, and a recording medium 24 such as paper is fed from the paper feed cassette 9 to a nip portion thereof. At the same time, a secondary transfer bias is applied from the power supply 29, and the composite color toner image is transferred from the intermediate transfer member 20a or 20b to the recording medium 24.
Is transferred to The recording medium 24 is introduced into the fixing device 15 and heat-fixed to form a final image. The transfer residual toner on the intermediate transfer member 20a or 20b is cleaned by contacting the cleaning device 35. The configuration of the intermediate transfer member of the present invention may be any as long as it has the universal hardness.
Although there is no particular limitation, it is preferable that the elastic layer and a coating layer provided thereon are formed from the viewpoint that the universal hardness can be easily adjusted to a desired value, and a metal or plastic core is provided as necessary. Gold, reinforcing thread, reinforcing cloth, and the like can be used. Note that the coating layer may be a plurality of layers as necessary.

FIG. 3 is a cross-sectional view showing an example of the structure of a drum-shaped intermediate transfer member of the present invention. In the drum-shaped intermediate transfer member 20a, an elastic layer 201 is provided around a cylindrical cored bar 200. And a drum-shaped structure in which a coating layer 202 is further provided thereon. FIG. 4 is a cross-sectional view illustrating a configuration of an example of a belt-shaped intermediate transfer member of the present invention.
1 has a belt-shaped structure in which a coating layer 202 is provided. Here, the material used for the elastic layer and the coating layer is not particularly limited, but is set forth below in order to control the universal hardness to a desired range and to ensure good bondability even during long-term use. A combination of materials is preferred.

The elastic layer is preferably composed mainly of a rubber material. Examples of the rubber material include nitrile rubber, ethylene propylene rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, silicone rubber, urethane rubber, and the like. Acrylic rubber, chloroprene rubber,
Butyl rubber, epichlorohydrin rubber and the like.
These may be used alone or in combination of two or more. Among these rubber materials, epichlorohydrin rubber, ethylene propylene rubber, and mixtures of these with other rubber materials are particularly suitable. Further, a conductive agent is usually added to the elastic layer in order to impart conductivity. The conductive agent includes an ionic conductive agent and an electronic conductive agent. Examples of the ionic conductive agent include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium, lauryltrimethylammonium, and the like.
Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluoroacids such as octadecyltrimethylammonium such as stearyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified aliphatic dimethylethylammonium Ammonium salts such as salts, sulfates, alkyl sulfates, carboxylates, sulfonates; lithium, sodium,
Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, trifluoromethyl sulfates, sulfonates, etc. of alkali metals or alkaline earth metals such as calcium and magnesium No.

On the other hand, as an example of the electronic conductive agent, Ketsch
Conductive carbon black such as carbon black and acetylene black.
Rack; SAF, ISAF, HAF, FEF, GPF,
Carbon black for rubber such as SRF, FT, MT; oxidation
Treated carbon black for ink, pyrolysis carb
Black, graphite; tin oxide, titanium oxide, acid
Conductive metal oxides such as zinc oxide; metals such as nickel and copper
Is mentioned. These conductive agents may be used alone,
A combination of more than one species may be used. In addition,
There is no particular limitation on the addition amount of the electric agent, and it depends on various situations.
Is selected as appropriate.
0.01 to 5 parts by weight, preferably 100 parts by weight
Or 0.05 to 2 parts by weight. Also, electronic conductivity
In the case of an agent, it is usually 1 to 50 parts by weight, preferably 5 to 40 parts by weight.
It is in the range of parts by weight. Thereby, the volume of the conductive elastic layer
Specific resistance value of 10^Three-10^TenΩ · cm, especially 10 ^Four~ 1
0⁸It is preferable to adjust to Ω · cm.

On the other hand, as a material of the coating layer, a material which has good followability to the elongation of the elastic layer and can be controlled within a desired universal hardness range is preferable, and for example, a polyurethane resin is preferable. As the polyol component of the polyurethane resin, known ones conventionally used as raw materials for the polyurethane resin, for example, polyether-based polyols, polyester-based polyols, polyolefin-based polyols and the like are used. Polyolefin-based polyols are preferred.

Examples of the polyester polyol include a condensation polyester polyol obtained by condensation of a dicarboxylic acid with a diol or a triol, a lactone polyester polyol obtained by ring-opening polymerization of a lactone in the presence of a diol or a triol, An ester-modified polyol obtained by ester-modifying the end of an ether polyol with a lactone is preferably used. Preferred examples of the polyolefin polyol include, for example, polyisoprene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, and the like. These polyol components may be used alone or in combination of two or more. On the other hand, as the polyisocyanate component, known polyisocyanate compounds (having two or more isocyanate groups in one molecule) conventionally used as raw materials for polyurethane resins, such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, Trizine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, cyclohexane diisocyanate, lysine ester diisocyanate, lysine ester triisocyanate, undecane triisocyanate,
Examples include hexamethylene triisocyanate, triphenylmethane triisocyanate, and polymers, derivatives, modified products, and hydrogenated products of these polyisocyanate compounds.

In the present invention, among these polyisocyanate compounds, at least one selected from aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds and hydrogenated aromatic polyisocyanate compounds has an ozone resistance. It is possible to provide a polyurethane resin having good stiffness, which is preferable. Particularly, modified hexamethylene diisocyanate and modified isophorone diisocyanate are preferable, and among them, isocyanurate-modified, buret-modified or adduct-modified hexamethylene diisocyanate and isophorone diisocyanate are preferable because of their good heat resistance.

In order to prevent toner from adhering, to reduce friction and adhesion, or to control electrostatic behavior of the toner, the coating layer has properties such as chargeability, capacitance and resistance. For the purpose of adjustment, if necessary, other resins such as fluororesin, silicone resin, polyester resin, acrylic resin, acrylic urethane resin, acrylic silicone resin, epoxy resin, phenol resin, melamine resin, or fine particles of fluororesin, silicone Resin fine particles, and further, a charge control agent and the like can be added. The resistance of this coating layer is preferably set higher than that of the elastic layer, and is 10 ⁶ to 10 ¹⁶ in volume specific resistance.
It is advantageous to set it to about Ω · cm. When a conductive agent is used for adjusting the resistance, the conductive agent described in the description of the elastic layer can be used as the conductive agent. The present invention also provides an image forming apparatus equipped with the intermediate transfer member. Examples of the image forming apparatus include those shown in FIGS. 1 and 2.

[0021]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A woven fabric was wound on a mandrel, and an elastic layer made of a rubber material whose resistance was adjusted by adding carbon black to a mixture of ethylene propylene rubber and nitrile rubber was provided thereon, and vulcanized. 240mm width, 450m circumference
A rubber belt having a thickness of 1 mm and a thickness of 1 mm was produced. The volume specific resistance of this rubber belt was 2.1 × 10 ⁶ Ωcm. On the other hand, the polyester polyol-containing material “Nipporan 31”
24 "[manufactured by Nippon Polyurethane Co., Ltd., one-component solvent dry type, solid content concentration: 50% by weight] 50 parts by weight, modified tolylene diisoanate" Coronate L "[manufactured by Nippon Polyurethane Co.,
Solid content concentration: 75% by weight] 11 parts by weight, 10 parts by weight of polytetrafluoroethylene powder (average particle size: 0.3 μm) and 100 parts by weight of methyl ethyl ketone were mixed to prepare a urethane resin paint.

Next, this coating material was spray-coated on the elastic layer of the rubber belt to produce a belt-shaped intermediate transfer member (intermediate transfer belt) having a polyurethane resin coating layer having a thickness of 30 μm. The volume specific resistance of the intermediate transfer belt was 3.5 × 10 ¹³ Ωcm. Indenter: square pyramid diamond indenter with facing angle of 136 degrees, initial load: 0.02 mN, maximum load:
A depth of 7 μm was obtained by setting the conditions of 100 mN and a load increase time from the initial load to the maximum load: 10 seconds.
Was 11.5 N / mm ² . The intermediate transfer belt was mounted on the full-color printer illustrated in FIG. 2, and an image durability test was performed at a 10% density of cyan. The average particle size of the used toner is about 7 μm
It is. As a result, no abnormality occurred in the image even after printing 20,000 sheets.

Example 2 As a urethane resin coating in Example 1, 50 parts by weight of "Nipporan 3124" (described above) and a modified product of hexamethylene diisocyanate "Duranate 22A-75PX" were used.
[Asahi Kasei Kogyo Co., Ltd., solid content 75% by weight] 11 parts by weight, polytetrafluoroethylene powder (average particle size 0.3 μm) 1
A belt-shaped intermediate transfer member (intermediate transfer belt) was produced in the same manner as in Example 1 except that a toner containing 0 parts by weight and 100 parts by weight of methyl ethyl ketone was used. The volume resistivity of the intermediate transfer belt was 5.1 × 10 ¹³ Ωcm. Universal hardness, ultra-micro hardness tester H-100
V (manufactured by Fisher), indenter: facing angle 13
6 degree quadrangular pyramid diamond indenter, initial load: 0.02m
N, the maximum load: 100 mN, the load increase time from the initial load to the maximum load: 10 seconds, the universal hardness at a depth of 7 μm was 15.4 N /
mm ² . The intermediate transfer belt was mounted on the full-color printer illustrated in FIG. 2, and an image durability test was performed at a 10% density of cyan. The average particle size of the used toner is about 7 μm. As a result, no abnormality occurred in the image even after printing 20,000 sheets.

Comparative Example 1 Carbon black 10 was added to 100 parts by weight of polycarbonate.
The weight was added and the mixture was melt-kneaded to prepare a pellet-shaped resin composition. Next, the resin composition is extruded by an extruder.
It was extruded in a molten tube state, and was cooled and solidified by contacting it on a cooling mandrel to produce an intermediate transfer belt having a thickness of 170 μm. The volume resistivity of the intermediate transfer belt is 4.3 ×
It was 10 ¹² Ωcm. Universal hardness was measured using an ultra-micro hardness tester H-100V (manufactured by Fisher), indenter: square pyramid diamond indenter with facing angle of 136 degrees, initial load: 0.02 mN, maximum load: 100 mN, maximum load to maximum load The time required to increase the load until: 10 seconds, the universal hardness at a depth of 7 μm was 89.2 N / mm ² . The intermediate transfer belt,
The image was mounted on the full-color printer illustrated in FIG. 2 and subjected to an image durability test at a cyan concentration of 10%. The average particle size of the used toner is about 7 μm. As a result, a point-like image defect began to occur after printing 8,000 sheets. When the intermediate transfer belt was taken out and observed, it was found that many toner particles were embedded on the surface.

Comparative Example 2 9 parts by weight of carbon black was added to 100 parts by weight of polybutylene terephthalate, and the mixture was melt-kneaded to prepare a pellet-shaped resin composition. Next, this resin composition was extruded in a molten tube state by an extruder, and was brought into contact with a cooling mandrel to be cooled and solidified, thereby producing an intermediate transfer belt having a thickness of 175 μm. The volume specific resistance of the intermediate transfer belt was 2.1 × 10 ¹² Ωcm. Indenter: square pyramid diamond indenter with facing angle of 136 degrees, initial load: 0.02 mN, maximum load: 100
mN, load increase time from initial load to maximum load: 10
When determined under the condition of seconds, the universal hardness at a depth of 7 μm was 92.3 N / mm ² . The intermediate transfer belt was mounted on the full-color printer illustrated in FIG. 2, and an image durability test was performed at a 10% density of cyan. The average particle size of the used toner is about 7 μm. As a result, a point-like image defect started to occur after printing 7,500 sheets. When the intermediate transfer belt was taken out and observed, it was found that many toner particles were embedded on the surface.

[0026]

As described above, the intermediate transfer member of the present invention can fix the toner by fixing the universal hardness at a depth corresponding to the average particle diameter of the toner used in the electrophotographic image forming apparatus to which the intermediate transfer member is applied. Is prevented, and the effect of improving durability is achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a color image forming apparatus using a drum-shaped intermediate transfer member of the present invention.

FIG. 2 is a schematic view of an example of a color image forming apparatus using a belt-shaped intermediate transfer member of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of an example of a drum-shaped intermediate transfer member of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of an example of a belt-shaped intermediate transfer member of the present invention.

[Explanation of symbols]

 1: Photoconductor 9: Paper feed cassette 14: Cleaning device 15: Fixing device 20a: Intermediate transfer member (drum shape) 20b: Intermediate transfer member (belt shape) 24: Recording medium 25: Transfer roller 35: Cleaning device 41: Development Device 42: developing device 43: developing device 44: developing device 200: core metal 201: elastic layer 202: coating layer

Claims (10)

[Claims] 1. An intermediate transfer member disposed between an image forming body and a recording medium, for temporarily transferring and holding a toner image formed on the surface of the image forming body onto the surface, and transferring the toner image to a recording medium. ^{2. The} intermediate transfer member according to claim 1, wherein the surface hardness of the member is 80 N / mm ² or less as a universal hardness at a depth corresponding to an average particle diameter of the toner used for forming the toner image. 2. An intermediate transfer member disposed between an image forming body and a recording medium, temporarily transferring and holding a toner image formed on the surface of the image forming body to the surface, and transferring the toner image to a recording medium. ^{3. The} intermediate transfer member according to claim 1, wherein the surface hardness of the member is 80 N / mm ² or less as a universal hardness at a depth of 7 μm. 3. A volume resistivity value of 10 ³ to 10 ¹⁶ Ω · c.
3. The intermediate transfer member according to claim 1, wherein m is m. 4. The intermediate transfer member according to claim 1, comprising an elastic layer and a coating layer provided on the surface of the elastic layer. 5. The intermediate transfer member according to claim 4, wherein the coating layer contains at least a polyurethane resin. 6. The intermediate transfer member according to claim 5, wherein the polyurethane resin uses a polyester polyol and / or a polyolefin polyol as a polyol component. 7. The polyurethane resin wherein at least one selected from aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds and hydrogenated aromatic polyisocyanate compounds is used as the polyisocyanate component. 6. The intermediate transfer member according to 5. 8. The intermediate transfer member according to claim 7, wherein the polyisocyanate component is modified hexamethylene diisocyanate or modified isophorone diisocyanate. 9. The intermediate transfer member according to claim 4, wherein the elastic layer contains ethylene propylene rubber, epichlorohydrin rubber, or a mixture thereof with another rubber material. 10. An image forming apparatus comprising the intermediate transfer member according to claim 1.