JPH1026891A - Intermediate transfer member and intermediate transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deposition or sticking of toner on the surface of an intermediate member and to obtain a high-quality image without blur or misalignment by forming a specified resin layer on the surface of the intermediate transfer member which temporarily holds a toner image of a latent image holding body and then transfers the image to a recording medium. SOLUTION: The intermediate transfer member 1 is disposed between an image holding body 2a-2d such as a photosensitive drum and a recording medium 3 such as a paper sheet. The member 1 temporarily transfers and holds a toner image formed on the surface of the latent image holding body 2a-2d on its surface and then transfers the image to a recording medium. A resin layer 4 of <30μm thickness containing a fluorocarbon resin is formed on the surface of the intermediate transfer member 1. The fluorocarbon resin in the resin layer is a dispersion type water-based fluorocarbon resin and its amt. is preferably controlled to >=60wt.%. Moreover, it is preferable that the resin layer contains carbon having >=6% oxygen content and pH>5 and at least one kind of resin selected from polyvinylacetal resin, polyester resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording process in an electrophotographic apparatus such as a copying machine or a printer or an electrostatic recording apparatus or the like, and develops the image on a surface of a latent image holding member having an electrostatic latent image on the surface. An intermediate transfer member for temporarily transferring and holding the toner image formed by supplying the agent before transferring the toner image to a recording medium such as paper, and transferring this to the recording medium, and an intermediate transfer member using the intermediate transfer member More specifically regarding the transfer device,
When performing color printing by the intermediate transfer method, blurring, misregistration, an intermediate transfer member capable of achieving high image quality by minimizing the occurrence of color misregistration, and using the intermediate transfer member The present invention relates to an intermediate transfer device.

[0002]

2. Description of the Related Art Conventionally, in an electrostatic recording process in a copying machine, a printer, or the like, first, the surface of a photosensitive member (latent image holding member) is uniformly charged. The electrostatic latent image is formed by projecting an image from the optical system to eliminate the charge of the light-irradiated portion, and then supplying toner to the electrostatic latent image and electrostatically attaching the toner to the toner. 2. Related Art A method of printing by forming an image and transferring the image to a recording medium such as paper is employed.

In this case, even in a color printer or a color copying machine, printing is basically performed in accordance with the above-described process. In the case of color printing, magenta, yellow, cyan, and black toners are used. To reproduce the color tone, it is necessary to perform a process of superimposing these toners at a predetermined ratio to obtain a necessary color tone,
Several schemes have been proposed for performing this step.

First, as in the case of monochrome printing, when the electrostatic latent image is visualized by supplying toner onto the photoreceptor, the above four colors of magenta, yellow, cyan and black are used. There is a multiple development system in which development is performed by sequentially superimposing toner to form a color toner image on a photoconductor. According to this method, it is possible to configure the apparatus relatively compact, but in this method, there is a problem that it is very difficult to control the gradation and high image quality cannot be obtained.

Second, by providing four photosensitive drums and developing the latent images of the respective drums with magenta, yellow, cyan, and black toners, a magenta toner image, a yellow toner image, and a cyan toner image are formed. And four toner images of a black toner image are formed, the photosensitive drums on which the toner images are formed are arranged in a line, and each toner image is sequentially transferred to a recording medium such as paper, and is superimposed on the recording medium. There is a tandem system for reproducing a color image. In this method, although a good image can be obtained, four photosensitive drums, and a charging mechanism, a developing mechanism, and a transfer mechanism provided for each photosensitive drum are arranged in a line, which increases the size of the apparatus and It will be expensive.

Third, a recording medium such as paper is wound around a transfer drum and rotated four times, and magenta, yellow, cyan, and black on the photoreceptor are sequentially transferred to the recording medium for each revolution to reproduce a color image. There is also a transfer drum system that performs the transfer. According to this method, a relatively high image quality can be obtained, but when the recording medium is thick paper such as a postcard, it is difficult to wind it around the transfer drum, and the type of recording medium is limited. There is.

As compared with the above-described multiple developing system, tandem system and transfer drum system, good image quality can be obtained, the apparatus is not particularly enlarged, and the type of recording medium is particularly limited. An intermediate transfer method has been proposed as a method without such a method.

That is, in this intermediate transfer system, an intermediate transfer member including a drum or a belt for temporarily transferring and holding a toner image on a photosensitive member is provided, and a magenta toner image, a yellow toner image, By arranging four photoconductors on which a toner image of cyan and a toner image of black are formed and sequentially transferring toner images of four colors onto an intermediate transfer member, a color image is formed on the intermediate transfer member. A color image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the toner images of four colors, it is possible to obtain high image quality, and four sets of a charging member, a developing member, a transfer member and a photosensitive member as in a tandem system. Since there is no need to arrange the bodies in a line, the size of the apparatus is not particularly increased, and the recording medium does not need to be wound around the drum, so that the type of recording medium is not limited.

However, in this intermediate transfer system, the transfer of the toner image from the photosensitive member to the intermediate transfer member and the transfer of the toner image from the intermediate transfer member to the recording medium must be performed twice. Therefore, trouble may occur particularly when transferring the toner image from the intermediate transfer member to the recording medium.
This is because the toner adheres and fuses on the intermediate transfer member as the number of prints increases, and the transfer efficiency to the recording medium is reduced, or an accurate toner image is transferred from the photoconductor due to the adhered toner. This may be because it may be difficult to do so.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to prevent toner from adhering and fusing to the surface of an intermediate transfer member when printing is performed by an intermediate transfer method in an electrostatic recording process. It is an object of the present invention to provide an intermediate transfer member capable of preventing the occurrence of a high-quality image free from blurring, positional shift, color shift, and the like, and an intermediate transfer device using the intermediate transfer member.

[0011]

Means for Solving the Problems and Embodiments of the Invention The present inventor has conducted intensive studies to achieve the above object, and as a result, when printing is performed by the intermediate transfer method, fluorine is applied to the surface of the intermediate transfer member. By forming the resin layer containing the resin and having a thickness of less than 30 μm, adhesion and fusion of the toner are prevented as much as possible, and a high-quality image without blur, misregistration, color misregistration, etc. can be reliably obtained. It has been found that the present invention has been completed.

Therefore, the present invention is provided between the latent image holding member and the recording medium, temporarily transfers and holds the toner image formed on the surface of the latent image holding member to its own surface, and transfers the toner image to the recording medium. And a resin layer containing a fluororesin and having a thickness of less than 30 μm is formed on the surface of the intermediate transfer member.

Further, the present invention is provided between a latent image holding member and a recording medium, and transfers and holds the toner image formed on the surface of the latent image holding member once to its own surface to record the toner image. An intermediate transfer device comprising an intermediate transfer member for transferring to a medium and voltage applying means for applying a voltage to the intermediate transfer member, wherein the intermediate transfer member of the present invention is used. Provide equipment.

In this case, the voltage applying means is used to transfer the toner image from the latent image holding member such as a photosensitive drum to the intermediate transfer member and to transfer the toner image from the intermediate transfer member to a recording medium such as paper. Thus, the applied voltage is switched between positive and negative to smoothly transfer the toner image.

Hereinafter, the present invention will be described in more detail.
As shown by reference numeral 1 in FIG. 1, the intermediate transfer member of the present invention has, for example, four photosensitive drums (latent image holders) 2a to 2a.
2d and a recording medium 3 such as paper, for temporarily transferring and holding the toner images formed on the surfaces of the photosensitive drums 2a to 2d, and transferring the toner images to the recording medium 3.
A resin layer 4 containing a fluororesin and having a thickness of less than 30 μm is formed on the surface.

In this case, the apparatus shown in FIG. 1 performs color printing by an intermediate transfer system, and includes a first developing device 6a for developing an electrostatic latent image on a photosensitive drum 2a with magenta, and a photosensitive drum. A second developing device 6b for developing the electrostatic latent image on the photosensitive drum 2c with cyan, and a third developing device 6c for developing the electrostatic latent image on the photosensitive drum 2c with cyan.
And a fourth developing device 6d for developing the electrostatic latent image on the photosensitive drum 2d with black is disposed around the intermediate transfer member 1, and the intermediate transfer member 1 is rotated so that each of the developing devices 6a-6
By sequentially transferring the four-color toner images formed on the photosensitive drums 2a to 2d to the intermediate transfer member 1, a color image is formed on the intermediate transfer member 1, and the color image is formed on paper or the like. This is transferred onto the recording medium 3 and printed. In the figure, reference numeral 5 denotes a main body of the intermediate transfer member 1, and reference numeral 7 denotes a recording medium feed roller. In the drawing, reference numeral 8 denotes the intermediate transfer member 1.
The power supply 8 applies a voltage to the intermediate transfer member 1 when transferring a toner image from the photosensitive drums 6 a to 6 d to the recording medium 3. The polarity of the applied voltage can be reversed between the time of transferring the image and the time of transferring the image.

The main body 5 of the intermediate transfer member 1 can be formed of metal or plastic. Here, in FIG. 1 described above, the drum-shaped intermediate transfer member 1 is shown, but the shape of the intermediate transfer member of the present invention is such that the intermediate transfer member is stably contacted or brought close to a latent image holding member such as the photoconductors 2a to 2d. Any shape other than the drum shape may be used as long as it can be formed. For example, the shape may be a belt shape. In the case of a belt shape,
A driving roller or a driving gear for driving the belt can be provided.

The resin layer 4 contains a fluororesin as described above, preferably at least 60% by weight.
More preferably, it contains 70% by weight or more, further preferably 80% by weight or more, particularly preferably 90% by weight or more. In addition, the thickness of the resin layer 4 is less than 30 μm, and preferably 1 to 20 μm in order to obtain good flexibility. In this case, the thickness is 30
If the thickness is more than μm, problems such as cracking due to long-time use and increase in cost will occur.

Examples of the fluororesin include polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer, and tetrafluoroethylene-
Ethylene copolymer, polychlorotrifluoroethylene,
Examples thereof include chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, and polyvinyl fluoride. Among them, a dispersion type aqueous fluororesin in which fine particles such as polytetrafluoroethylene are dispersed in water is preferably used. The particle size of the fine particles in this case is not particularly limited, but may be 0.01 to 1
It is preferably set to 00 μm.

As the resin mixed with the above fluororesin, polyvinyl acetal resin, urethane resin, polyester resin, acrylic resin, nylon resin, etc. can be used. It is preferable to use a polyvinyl acetal resin, a urethane resin, or a polyester resin, and a polyvinyl acetal resin is particularly preferable. That is, when a water-based fluororesin and a water-based polyvinyl acetal resin are combined, a uniform coating film can be formed while increasing the ratio of the water-based fluororesin.

It is also possible to mix isocyanate, melamine resin, glyoxal and the like, whereby a resin other than a fluorine resin such as a polyvinyl acetal resin can be crosslinked to improve the strength. In this case, a block polyisocyanate that can be emulsified in water is particularly preferably used. It is appropriate that the amount of these additives is about 5 to 40 parts by weight per 100 parts by weight of the resin other than the fluororesin.

Further, although not particularly limited, carbon is usually added to the resin layer 4 in order to impart appropriate conductivity. In this case, the oxygen content of ordinary carbon is about 0.1 to 3%, but in the present invention, carbon having an oxygen content of 6% or more, particularly 7% or more, and further preferably 9% or more is used. preferable. Further, the pH of carbon is preferably 5 or more, particularly 6 or more, and more preferably 7 or more.

That is, the oxygen content of carbon is usually 0.1.
Although it is about 1 to 3%, carbon has a higher dispersibility as the oxygen content is higher, and on the other hand, when the pH is low and acidic, there is a problem that the stability is reduced particularly when added to an aqueous resin. Becomes In this case, carbon partially oxidized is known, and the oxygen content of the carbon is increased by the oxidizing treatment, but the pH is shifted to the acidic side, and the above problem is easily caused. On the other hand, carbon suitably used in the present invention has a high oxygen content and maintains neutrality or alkalinity, as described above. Specifically, although the detailed structure is not clear, And those having a carboxyl group, a hydroxyl group, a ketone group and the like on the carbon surface, and a part of hydrogen of these groups is substituted by an alkali metal such as sodium.

When such carbon is used,
Other conductive substances may be used as a mixture, and examples of the other conductive substances include ordinary carbon, metal oxides, and conductive polymers.

The amount of the conductive material such as carbon is not particularly limited, and is appropriately selected according to a desired resistance value. Suitable surface resistance of the intermediate transfer member of the present invention is such that the volume resistance is 10 ⁵ to 10 ¹⁸ Ωcm, and the amount of the conductive substance can be selected so as to obtain such a resistance value. 0.001 to 100 parts by weight of the resin component
It is about 80 phr.

Further, the resin layer 4 may contain additives such as a thixotropy-imparting agent and a structural viscosity-imparting agent. These may be either inorganic or organic and may be, for example, a silica compound. be able to.

The resin layer 4 is formed on the intermediate transfer member 1 of the present invention.
Although it can be formed directly on the main body 5, it is usually preferable to provide an elastic layer inside the resin layer 1.

The elastic layer is not particularly limited, and may be a resin such as urethane, rubber, or a foam thereof. However, it is preferable that the main material contains nitrile rubber (NBR). From the viewpoint of increasing hardness, the content of the NBR rubber is preferably contained in the range of 10 to 90% by weight in the elastic base material. The rubber components other than the NBR type include chloroprene rubber (CR), isoprene rubber (IR), styrene butadiene rubber (SBR), ethylene propylene rubber (EPDM), and butyl rubber (II).
R), natural rubber (NR), butadiene rubber (BR), acrylic rubber (ACR), epichlorohydrin rubber (EC
O) and other thermoplastic rubbers such as styrene-butadiene-styrene rubber (SBS) or its water additive (SEBS), and foams thereof, and are not particularly limited. , Workability of elastic layer,
From the viewpoint of hardness and the like, it is preferable to add BR or IR having a low viscosity to NBR. In this case, a preferable mixing ratio is NBR: (BR + IR) = 10 to 90:90 by weight% when the whole rubber material of the elastic layer is 100.
10 to 10.

Further, a conductive material can be added to the elastic layer to impart or adjust the conductivity. In this case, the conductive material is not particularly limited, and lauryltrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, perchlorate of a modified fatty acid / dimethylethylammonium salt, chloric acid Cationic surfactants such as quaternary ammonium salts such as salts, borofluorides, sulfates, ethosulfate salts, benzyl halide salts (verzyl bromide salts, benzyl chloride salts, etc.); aliphatic sulfonic acids, higher Anionic surfactants such as alcohol sulfates, higher alcohol ethylene oxide addition sulfates and higher alcohol phosphates; amphoteric surfactants such as various betaines; higher alcohols ethylene oxide and polyethylene glycol Le fatty acid esters, antistatic agents such as nonionic antistatic agents such as polyhydric alcohol fatty acid _{esters; LiCF 2 SO 2, NaClO 4} , LiBF 4, NaC
1; metal salts of the first group of the periodic table such as l; metal salts of the second group of the periodic table such as Ca (ClO ₄ ) ₂ ; and groups having an active hydrogen in which these antistatic agents react with isocyanate (hydroxyl group,
And those having one or more carboxyl groups, primary or secondary amine groups, and the like. Further, ions such as complexes of these with polyhydric alcohols (1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, etc.) or derivatives thereof, or complexes with ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. Conductive agent; conductive carbon such as Ketjen black, acetylene black, etc .; SA
F, ISAF, HAF, FEF, GPF, SRF, F
Rubber carbon such as T and MT; carbon for oxidation color ink, pyrolytic carbon, natural graphite, artificial graphite, etc .; metals and metal oxides such as tin oxide, titanium oxide, zinc oxide, nickel and copper; Examples thereof include conductive polymers such as polyaniline, polypyrrole, and polyacetylene.

The amount of the conductive material to be added to the elastic layer can be 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the resin or rubber component. The resistance value of the elastic layer is 10 ⁵ to 10 ¹¹ Ωcm
Can be adjusted.

Further, another resin layer or a rubber layer can be formed between the elastic layer and the resin layer 4 according to the purpose.

Other materials for forming the resin layer or the rubber layer include chlorinated polyethylene, chlorosulfonated polyethylene, polyester resin, acrylic resin, urethane resin, polydioxolane resin, urethane-modified acrylic resin, nylon Examples include a resin, an epoxy resin, a styrene resin, and a polyvinyl acetal resin. Of these, chlorinated polyethylene and chlorosulfonated polyethylene are particularly preferably used.

In the other resin layer or rubber layer, the same conductive material as that of the elastic layer is used in an amount of 0.01 to 50 parts by weight, preferably 0.1 to 50 parts by weight, based on 100 parts by weight of the resin or rubber component.
About 30 parts by weight, and the resistance value is 10 ⁵ to 10 ¹¹ Ω
cm. The thickness of the other resin layer or rubber layer is not particularly limited, but can be generally about 1 to 600 μm.

The intermediate transfer member of the present invention is not particularly limited, but has a surface roughness of JIS 10 point average roughness Rz.
It is preferably 10 μm or less, particularly 6 μm or less, and more preferably 3 μm or less. Further, as in the apparatus shown in FIG. 1, a voltage can be applied to the intermediate transfer member of the present invention. In this case, the application conditions are appropriately selected such as application of DC only or application of superimposing AC on DC. can do.

[0035]

According to the intermediate transfer member of the present invention and the intermediate transfer apparatus using the intermediate transfer member, the toner adheres and fuses on the surface of the intermediate transfer member when printing is performed by an intermediate transfer method in an electrostatic recording process. Wearing is prevented as much as possible, and a high-quality image free from blurring, positional deviation, color deviation, and the like can be reliably obtained.

[0036]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. [Example 1] On a drum-shaped main body having a rubber layer shown in Table 1, a coating layer A having a thickness of 90 µm and a coating layer B having a thickness of 10 µm were further formed, followed by intermediate transfer. A member was obtained.
In this case, the coating layer A is formed using a coating material in which 15 parts by weight of carbon, 100 parts by weight of polyethylene chloride and 20 parts by weight of silica are mixed, and the coating layer B is formed of a water-dispersible fluororesin and polyvinyl acetal. 0.1 parts of carbon SMP-4 was added to 100 parts by weight of a resin component obtained by mixing a resin and 9/1.
It was formed by using a paint mixed with parts by weight. The carbon SMP-4 has an oxygen content of 10% and a pH of 7.33, and the obtained intermediate transfer member has a surface roughness of:
The JIS 10 point average roughness Rz was 1.1 μm.

[0037]

[Table 1]

This intermediate transfer member was mounted as an intermediate transfer drum 1 on a color printer having the same mechanism as that shown in FIG. 1, and 4,000 images were continuously output. The obtained image was good to the end and no trouble occurred.
After the test, the intermediate transfer drum was removed and the surface thereof was examined. As a result, there was almost no toner adhesion, and there was no abnormality in the shape of the coating film.

Comparative Example 1 An intermediate transfer member was prepared in the same manner as in Example 1 except that the coating layer C was used instead of the coating layer B. Coating C is alcohol soluble nylon 100
It is formed using a paint in which 17 parts by weight of carbon 2350 for ink is added to parts by weight. The carbon 2350 for ink has a pH of 2.0, and the surface roughness of the intermediate transfer member is JIS 10 point average roughness Rz.
Was 17 μm.

Using this intermediate transfer member, an image output test was conducted in the same manner as in Example 1. As a result, the image was blurred and lacked sharpness. After the test, the intermediate transfer drum was removed and its surface was examined. As a result, it was found that the toner adhered badly and was partially fused.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an intermediate transfer member of the present invention and an intermediate transfer device using the intermediate transfer member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intermediate transfer member 2a-2d Photosensitive drum (latent image holding body) 3 Recording medium 4 Resin layer 5 Main body of intermediate transfer member 6a-6d Developing device 7 Paper feed roller 8 Power supply device (voltage applying means)

Claims (9)

[Claims] An intermediate device which is disposed between a latent image holding member and a recording medium, temporarily transfers and holds a toner image formed on the surface of the latent image holding member to its own surface, and transfers this to a recording medium. In the transfer member, the thickness containing the fluororesin on the surface is 30
An intermediate transfer member having a resin layer of less than μm. 2. The fluororesin content in said resin layer is 6
2. The intermediate transfer member according to claim 1, wherein the amount is 0% by weight or more. 3. The intermediate transfer member according to claim 1, wherein the fluororesin is a dispersion type aqueous fluororesin. 4. The resin layer according to claim 1, wherein said resin layer contains carbon having an oxygen content of 6% or more and a pH of 5 or more.
4. The intermediate transfer member according to any one of claims 1 to 3. 5. The resin layer according to claim 1, wherein the resin layer contains one or more selected from a polyvinyl acetal resin, a polyester resin, a polyurethane resin, a nylon resin, and an acrylic resin. 14. The intermediate transfer member according to item 13. 6. The method according to claim 1, wherein the resin layer is an isocyanate compound,
The intermediate transfer member according to claim 1, wherein the intermediate transfer member is cross-linked with glyoxal or a melamine resin. 7. The surface roughness is JIS 10 point average roughness Rz
The intermediate transfer member according to claim 1, wherein the intermediate transfer member has a scale of 10 μm or less. 8. The intermediate transfer member according to claim 1, wherein the resin layer is formed on an elastic layer. 9. A toner image formed between a latent image holding member and a recording medium, and a toner image formed on the surface of the latent image holding member is temporarily transferred and held on its own surface, and is transferred to a recording medium. An intermediate transfer device comprising: an intermediate transfer member; and a voltage application unit for applying a voltage to the intermediate transfer member, wherein the intermediate transfer member according to any one of claims 1 to 8 is used as the intermediate transfer member. An intermediate transfer device characterized by using: