JPH0728338A - Intermediate transfer body and image forming method using it - Google Patents

Abstract

PURPOSE:To obtain a high-quality image with excellent reproducibility as for an image forming method using an intermediate transfer body because the intermediate transfer body is provided with excellent durability and excellent transfer property. CONSTITUTION:As for the intermediate transfer body used for the image forming method by which an electrostatic latent image on an electrostatic latent image carrier is developed by liquid toner, the developed image developed by this developing is electrostatically transferred on the intermediate transfer body and the developed image on the intermediate transfer body is transferred again on a material to be transferred thereafter; a surface peeling layer including at least silicone rubber and adhesion imparting agent and an electrical conductive fluoro-rubber layer are provided in this turn from an outside surface side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention develops an electrostatic latent image on an electrostatic latent image carrier with liquid toner, and electrostatically transfers the visualized image developed by this development to an intermediate transfer body. The present invention relates to an intermediate transfer member used in an image forming method for subsequently retransferring a visible image on the intermediate transfer member onto a transfer target material. For example, it is used in an image forming method used in a copying machine or a laser beam printer. It relates to an intermediate transfer member.

[0002]

2. Description of the Related Art The following intermediate transfer members are used in the above-described image forming method.

For example, Japanese Patent Application Laid-Open No. 3-154085 (Prior Art 1) discloses an intermediate transfer member having an elastic layer composed of a dielectric layer having a smooth surface and a thin dielectric layer and a conductive layer supporting the dielectric. Regarding the material of the dielectric layer, there is only a description that a material such as a silicone coat or a fluorine coat may be used.

Further, JP-A-3-243973 (Prior Art 2) discloses an intermediate transfer member having an elastic layer having a smooth surface and having a property of absorbing a solvent in a liquid toner. This elastic layer is composed of a dielectric layer and a conductor layer, and specifically, an intermediate body obtained by coating a conductive silicone rubber with an insulating silicone rubber is mentioned.

Further, Japanese Patent Application Laid-Open No. 1-273075 (conventional example 3) discloses an intermediate transfer member having a dielectric layer formed on a conductive base material. Specifically, the intermediate transfer member is formed by providing a dielectric layer made of a polytetrafluoroethylene layer on a conductive base material made of urethane rubber.

[0006]

The requirements for the intermediate transfer member used in the above-described image forming method include the following items.

(1) The visible image is efficiently transferred to the intermediate transfer member.

(2) The visible image on the intermediate transfer member is efficiently retransferred onto the transfer material.

(3) The intermediate transfer member has durability.

However, none of the above-mentioned conventional examples 1 to 3 satisfy all of the above requirements (1) to (3).

For example, as in the case of the conventional example 1, simply using a material such as a silicone coat or a fluorine coat cannot provide sufficient durability. Further, in Conventional Example 2, since conductive silicone rubber is used for the elastic layer, there is a problem that the visible image on the intermediate transfer member is disturbed because the elastic layer swells with the solvent used for the liquid toner. Further, in Conventional Example 3, since polyurethane rubber is used for the elastic layer, there is a problem that the heat resistance of the polyurethane rubber is insufficient when the method of retransferring onto the transfer material with a heat roller is used. there were.

The present invention was conceived in view of the above-mentioned drawbacks, and it is an object of the present invention that a visible image is efficiently transferred to an intermediate transfer member, and that the visible image on the intermediate transfer member is transferred. An object is to provide an intermediate transfer member which satisfies the three requirements of being efficiently retransferred onto a material and having durability of the intermediate transfer member.

[0013]

The object of the present invention is as follows.
The electrostatic latent image on the electrostatic latent image carrier is developed with liquid toner, the developed image visualized by this development is electrostatically transferred to the intermediate transfer body, and then the developed image on the intermediate transfer body. In the intermediate transfer member used in the image forming method of re-transferring
This is achieved by an intermediate transfer member characterized in that a surface release layer containing at least silicone rubber and an adhesion promoter and a conductive fluororubber layer are provided in this order from the outer surface side.

The present invention will be described in detail below.

The intermediate transfer member of the present invention comprises a surface peeling layer containing at least silicone rubber and an adhesiveness-imparting agent and a conductive fluororubber layer, which are provided in this order from the outer surface side. At least a conductive fluororubber layer on a substrate such as a film may be in the form of a belt in which a surface release layer containing a silicone rubber and an adhesion promoter is sequentially laminated, or a drum such as aluminum or iron, It may be in the form of a drum in which at least a conductive fluororubber layer and a surface release layer containing a silicone rubber and an aminosilane coupling agent are sequentially laminated. Further, an adhesive layer may be provided between the conductive fluororubber layer and the substrate or between the conductive fluororubber layer and the drum.

A surface peeling layer containing silicone rubber and an adhesion promoter is provided on the outer surface of the intermediate transfer member.

The silicone rubber contained in the surface peeling layer has a function of lowering the adhesive force of the liquid toner to the intermediate transfer member and improving the transferability from the intermediate transfer member to the transfer material. Further, by absorbing the carrier solvent of the toner by the intermediate transfer member, the toner image on the intermediate transfer member is fixed to some extent, and the multiple transfer property (from the electrostatic latent image carrier to the intermediate transfer member) is also improved. As the silicone rubber, known methyl silicone rubber, methylphenyl silicone rubber, methyl vinyl silicone rubber and the like are used, but the silicone rubber is not limited thereto.

As the adhesiveness-imparting agent contained in the surface release layer, an aminosilane coupling agent can be used. The aminosilane coupling agent has a function of enhancing the adhesion between the surface release layer and the conductive fluororubber layer and improving the durability of the intermediate transfer member. As aminosilane coupling agents, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3
-Aminopropyldiethylmethylsilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, p-aminophenyltrimethoxysilane and the like can be mentioned, but the invention is not limited thereto.

The aminosilane coupling agent is preferably contained in the surface release layer in an amount of 1% by weight or more and 20% by weight or less, more preferably 2% by weight or more and 10% by weight or less. Here, when the amount of the aminosilane coupling agent is less than 1% by weight, the adhesive force between the surface peeling layer and the conductive fluororubber layer is insufficient, and the durability of the intermediate transfer member becomes poor. In addition, 20 aminosilane coupling agents
When it is contained in excess of the weight%, the adhesive force of the liquid toner to the intermediate transfer body becomes high, and the transferability from the intermediate transfer body to the transfer material becomes poor.

The surface release layer may contain a crosslinking agent for silicone rubber such as methyltrimethoxysilane.

The thickness of the surface release layer is 0.2
It is preferable that it is not less than μm and not more than 5 μm. More preferably, it is 0.5 μm or more and 3 μm or less. If it is less than 0.2 μm, the transfer rate from the intermediate transfer member to the transfer target is not sufficient, and if it exceeds 5 μm, there is a problem in color superimposition.

In the intermediate transfer member of the present invention, a conductive fluororubber layer is provided below the surface peeling layer. The conductive fluororubber layer is used as a conductive elastic layer. That is, when using a heat roller containing a heat source when transferring from the intermediate transfer member to the transfer material,
The conductive elastic layer is required to have heat resistance, and further, it is required not to swell in the hydrocarbon solvent used for the liquid toner. Therefore, it is necessary to use the conductive fluororubber layer.

Specific examples of the conductive fluororubber layer used in the intermediate transfer member of the present invention include vinylidene fluoride-hexafluoropropene-based, vinylidene fluoride-chlorotrifluoroethylene-based, vinylidene fluoride-penta. Examples include fluoropropene-based, tetrafluoroethylene-propylene-based, fluorine-containing silicon-based, fluorine-containing nitroso-based, fluorine-containing triazine-based, and fluorine-containing phosphazene-based dispersions of carbon black for imparting conductivity. .

As the carbon black dispersed in the fluororubber, any known carbon black can be used, but it is preferable to use Ketjen black in order to impart good conductivity. The dispersion amount of carbon black is preferably 2% by weight or more and 10% by weight or less. If it is less than 2% by weight, the conductivity becomes insufficient, and 10
When the content exceeds the weight%, there is a problem that the smoothness of the surface of the conductive layer is lost.

The conductive fluororubber layer preferably has a volume specific resistance of 10 ⁸ (Ω · cm) or less.
It is more preferably ⁵ (Ω · cm) or less. When the volume resistivity exceeds 10 ⁸ (Ω · cm), an image is formed by superimposing multiple colors on the intermediate transfer member, and the visible image on the intermediate transfer member is transferred by one transfer. In the case of re-transferring onto the body, when the image on the photoconductor is transferred onto the already transferred image on the intermediate transfer body, there is a problem that the transferability is lowered. The hardness of the conductive fluororubber layer is preferably Shore D10 or more and 50 or less. When the Shore D is less than D10, there is a problem that the image is disturbed when a visible image is transferred from the electrostatic latent image carrier (photoconductor) to the intermediate transfer member. If the Shore D50 is exceeded, when the intermediate transfer member is transferred to the transfer target, the transfer rate tends to be poor when the transfer target has poor surface smoothness such as paper.

The thickness of the conductive fluororubber layer is 5
It is preferably 0 μm or more and 5,000 μm or less.
It is more preferably 500 μm or more and 3,000 μm or less. When it exceeds 5,000 μm, there is a problem that the image is disturbed when a visible image is transferred from the electrostatic latent image carrier (photoreceptor) to the intermediate transfer member. Further, when it is less than 50 μm, when transferring from the intermediate transfer member to the transfer material, the transfer rate tends to be inferior when the transfer material has poor surface smoothness such as paper.

It is also possible to replace the lower side (substrate, drum side) of the conductive fluororubber layer with a layer made of another material. For example, a non-conductive fluororubber layer, a butyl rubber layer, a polyurethane rubber layer, a neoprene rubber layer, etc. which have a function as a cushion layer can be used. The thickness that can be replaced with another material such as a cushion layer is 40 to 4,000 μm.

Next, an image forming method using the intermediate transfer member of the present invention will be described.

The intermediate transfer member of the present invention develops the electrostatic latent image on the electrostatic latent image carrier with liquid toner, and electrostatically transfers the visualized image developed by this development to the intermediate transfer member. After that, it is used in the image forming method of re-transferring the visible image on the intermediate transfer member onto the transfer material. This image forming method is used, for example, in a copying machine or a laser beam printer.

The intermediate transfer member of the present invention is, among other things, an image forming method in which the transfer material is brought into close contact with the intermediate transfer member by a pressure roller when the transferred image is retransferred onto the transfer material. It is preferably used. Examples of the pressure roller used here include a metal roller, and a roller in which the surface of the metal roller is covered with a highly heat-resistant rubber such as silicone rubber or fluororubber in order to enhance the adhesion with the intermediate transfer member. Especially, it is preferable that the pressure roller is used in the image forming method, which is a heat roller including a heat source. As such a pressure roller, one having a cylindrical structure and including a heat source such as a ceramic heater or a halogen lamp can be mentioned.

Further, the image forming method is a color image forming method, in which multiple colors are superimposed on the intermediate transfer member to form a color image, and a visible image on the intermediate transfer member is formed by one transfer. An image forming method of re-transferring onto a transfer material is preferable.

The transfer material referred to in the present invention may be of any type as long as it can be normally printed, such as paper, plastic film, metal, cloth and board.

[0033]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these.

Example 1 Tetrafluoroethylene-propylene rubber type "Aflas"# 150 (made by Asahi Glass Co., Ltd.) was added on a 200 .mu.m aluminum plate, and 5% by weight of Ketjen Black was added to the composition.
An electrically conductive fluororubber layer of 0 μm vulcanized and molded Shore D20 was provided, and a surface release layer having the following constitution was provided thereon by bar coating to be 2 μm to form an intermediate transfer member.

3-aminopropyltriethoxysilane 5% by weight Deoxime room temperature curable methylsilicone rubber 95% by weight Using a Se drum as a photoreceptor, development with a liquid developer,
An image is formed in order of yellow, red, indigo, and black on the intermediate transfer body attached on the drum, a full color image is formed on the intermediate transfer body, and the full-color image is applied with a linear pressure of 20 kg on the paper. Further, when the transfer was performed under the condition that the temperature of the pressure roller was 150 ° C., a good printed matter could be obtained. Further, 2,000 sheets were continuously printed, but a printed matter equivalent to the first sheet was obtained, and the intermediate transfer body could be used without any defect.

Example 2 Tetrafluoroethylene-propylene rubber system "Aflas"# 15 on a 180 mm diameter aluminum drum.
0 (manufactured by Asahi Glass Co., Ltd.) was provided with a conductive fluororubber layer of 500 μm vulcanized and molded Shore D20 to which 5 wt% of Ketjen black was added, and a surface release layer having the following constitution was formed thereon by bar coating. An intermediate transfer member was formed by providing 5 μm.

3-Aminopropyltrimethoxysilane 3% by weight Deacetic acid type room temperature curing type methylsilicone rubber 97% by weight Using this intermediate transfer member, printing was performed in the same manner as in Example 1, and a good printed matter was obtained. I was able to get it. further,
Although 2,000 sheets were continuously printed, the same printed matter as the first sheet was obtained, and the intermediate transfer member could be used without any defect.

Example 3 A vinylidene fluoride-hexafluoropropene rubber system, Daier G, was placed on a 200 .mu.m stainless steel plate.
-501 (manufactured by Daikin Industries) with 6 Ketjen Black
800 μm vulcanization molded Shore D30 added with wt%
An electroconductive fluororubber layer of 1 was provided, and a surface peeling layer having the following constitution was provided thereon by bar coating in an amount of 1 μm to form an intermediate transfer member.

N- (2-aminoethyl) -3-aminopropyltrimethoxysilane 3% by weight Deacetic acid type room temperature curable methyl silicone rubber 97% by weight This intermediate transfer member was shaped like a belt and the same as in Example 1. When printed on, good prints could be obtained. In addition, 2,000 sheets were printed continuously,
A printed matter equivalent to that of the first sheet was obtained, and the intermediate transfer body could be used without any defect.

Comparative Example 1 Tetrafluoroethylene-propylene rubber type "Aflas"# 150 (made by Asahi Glass Co., Ltd.) was added on a 200 μm aluminum plate, and 5 wt% of Ketjen Black was added to the composition.
An electroconductive fluororubber layer of 0 μm vulcanized and molded Shore D20 was provided, and a deoxime type room temperature curable silicone rubber layer was directly provided thereon by 2 μm by bar coating to form an intermediate transfer member.

When printing was performed in the same manner as in Example 1, good printed matter was obtained up to the 100th sheet, but 10
Defects began to appear on the printed matter from the time when the number of sheets exceeded zero. When the intermediate transfer member was removed and examined, it was found that the silicone rubber layer was peeled from the conductive fluororubber layer.

Comparative Example 2 Volume resistivity of 10 ³ Ω · cm on a 200 μm aluminum plate
A conductive silicone rubber having a thickness of 1 mm was provided, and a deoxime type room temperature curing type silicone rubber layer was provided thereon by bar coating to have a thickness of 1.5 μm to form an intermediate transfer member.

When printing was performed in the order of yellow, red, and indigo in the same manner as in Example 1, the intermediate transfer member swelled with the liquid toner and the visible image was disturbed, and a good printed matter could not be obtained.

Comparative Example 3 On a 200 μm aluminum plate, the volume resistivity was 10 ³ Ω · cm.
A conductive urethane rubber having a thickness of 1 mm was provided, and a surface peeling layer having the following constitution was provided thereon by bar coating for 1 μm to form an intermediate transfer member.

N- (2-aminoethyl) -3-aminopropyltrimethoxysilane 3% by weight Deacetic acid type room temperature curable methyl silicone rubber 97% by weight When printing was carried out in the same manner as in Example 1, the urethane rubber layer was found to be Due to thermal deformation, the transfer from the intermediate transfer body to the paper became defective, and good printed matter could not be obtained.

[0046]

Since the intermediate transfer member of the present invention uses the conductive fluororubber layer as the conductive elastic layer, a heat source is used when the image on the intermediate transfer member is retransferred onto the transfer material. The heat resistance is sufficient even when using a heat roller that contains, and it has excellent transferability. Furthermore, since the surface release layer contains an adhesion-imparting agent such as an aminosilane-based silane coupling agent, the durability of the intermediate transfer member itself is sufficiently practical. Therefore, when an image is formed using the intermediate transfer member of the present invention, a high quality image can be obtained with good reproducibility.

Claims (9)

[Claims] 1. An electrostatic latent image on an electrostatic latent image carrier is developed with liquid toner, the developed image visualized by this development is electrostatically transferred to an intermediate transfer body, and then the intermediate transfer is carried out. In an intermediate transfer member used in an image forming method for retransferring a visible image on a body to a transfer material, at least a surface release layer containing a silicone rubber and an adhesiveness-imparting agent and a conductive fluororubber layer are provided from the outer surface side. An intermediate transfer member, which is provided in this order. 2. The intermediate transfer member according to claim 1, wherein the adhesiveness-imparting agent is an aminosilane coupling agent. 3. The intermediate transfer member according to claim 1, wherein the surface release layer contains the aminosilane coupling agent in an amount of 1% by weight or more and 20% by weight or less. 4. The surface release layer has a thickness of 0.2 μm or more and 5 μm or more.
It is the following, The intermediate transfer body in any one of Claims 1-3. 5. The conductive fluororubber layer has a thickness of 50 μm or more and 5,000 μm or less.
4. The intermediate transfer member according to any one of 4 above. 6. An electrostatic latent image on an electrostatic latent image carrier is developed with liquid toner, the developed image visualized by this development is electrostatically transferred to an intermediate transfer body, and then the intermediate transfer is carried out. An image forming method for re-transferring a visible image on a body onto a transfer material, wherein the intermediate transfer member is an image forming method for re-transferring a visible image on the intermediate transfer material to the transfer material. 5. An image forming method using the intermediate transfer member according to any one of 5 above. 7. The image forming method according to claim 6, wherein when the visible image on the intermediate transfer member is retransferred onto the transfer material, the transfer material is brought into close contact with the intermediate transfer member with a pressure roller. Method. 8. The image forming method according to claim 7, wherein the pressure roller is a heat roller including a heat source. 9. The image forming method is a color image forming method, wherein a color image is formed by superimposing multiple colors on an intermediate transfer member, and the image is formed on the intermediate transfer member by one transfer. 9. The image forming method according to claim 6, wherein the image is retransferred onto the transfer material.