JP6048202B2 - Intermediate transfer belt, image forming apparatus, and method of manufacturing intermediate transfer belt - Google Patents

Description

  The present invention relates to an intermediate transfer belt, an image forming apparatus, and an intermediate transfer belt manufacturing method.

  Conventionally, seamless belts have been used as members for various uses in electrophotographic apparatuses. Particularly in recent full-color electrophotographic apparatuses, an intermediate transfer belt system in which developed images of four colors of yellow, magenta, cyan, and black are once overlaid on an intermediate transfer medium, and then collectively transferred to a transfer medium such as paper. Is used.

  Such an intermediate transfer belt system has been used in a system that uses four color developing devices for one photoconductor, but has a drawback in that the printing speed is slow. For this reason, as a high-speed print, a four-tandem tandem method is used in which the photoreceptors are arranged for four colors and each color is continuously transferred to paper. However, in this method, there are fluctuations due to the environment of the paper, etc., and it is very difficult to match the position accuracy of overlapping each color image, causing a color misregistration image. Therefore, in recent years, it has become the mainstream to adopt the intermediate transfer method for the quadruple tandem method.

  Under such circumstances, the required characteristics (high-speed transfer, positional accuracy) of the intermediate transfer belt are also stricter than before, and it is necessary to satisfy the characteristics corresponding to these requirements. Yes.

The intermediate transfer belt has a primary transfer function of receiving toner from the image carrier and a secondary transfer function of transferring toner to the paper, and both require an improvement in transfer rate.
In particular, in the secondary transfer, if the transfer rate is low, the toner that could not be transferred onto the paper remains on the intermediate transfer belt, which is liable to cause image defects and filming.

In recent years, the demand for printing not only on plain paper but also on uneven paper has increased, and the development of intermediate transfer belts that can support uneven paper is also becoming increasingly common.
In general, printing on uneven paper tends to have a lower secondary transfer rate than plain paper. The cause is that the intermediate transfer belt does not adhere to the concave portion of the paper, so that the toner cannot be transferred onto the paper and the toner is not transferred onto the intermediate transfer belt. Can be left behind.

Therefore, development of an intermediate transfer belt having a multilayer structure and an elastic layer in the layer and having good followability to uneven paper has been actively conducted.
For the elastic layer, rubber or elastomer is generally used in order to provide followability to the uneven paper, but transfer to the uneven paper is increased by using rubber having lower hardness.
In general, when kneading rubber, fatty acids are added for the purpose of vulcanization accelerators and lubricants for processing aids.

However, when the intermediate transfer belt is stored, there is a problem that the fatty acid remaining in the rubber blooms on the surface over time. In particular, bloom is likely to occur when stored at low temperature after being stored at high temperature and high humidity. Since the intermediate transfer belt is in contact with the photoconductor, the bloomed fatty acid adheres to the photoconductor, and the contaminated photoconductor may be deteriorated and the image quality may be deteriorated. Therefore, as a means for preventing bloom in general, a resin surface layer is laminated. (Patent Document 1, Patent Document 2)
However, when the rubber hardness of the elastic layer is low, cracks and wrinkles are generated when a relatively hard surface layer such as a resin or an elastomer is laminated. In the case of a highly flexible surface layer, the toner releasability is poor and the transfer rate of toner from the intermediate transfer belt to the paper tends to be poor, and it is difficult to achieve both.

  SUMMARY An advantage of some aspects of the invention is that it provides an intermediate transfer belt that can prevent bloom and can perform stable transfer over a long period of time.

As a result of intensive studies, the present inventors have found that the above problem can be solved by controlling the amount and type of fatty acid contained in the elastic layer of the intermediate transfer belt.
That is, according to the present invention, in the intermediate transfer belt having an elastic layer, the amount of the fatty acid contained in the elastic layer is 0.005% by mass to 0.020% by mass with respect to the weight of the elastic layer, and the fatty acid is 2%. It is an intermediate transfer belt characterized in that there are more than one type.

  According to the present invention, it is possible to provide an intermediate transfer belt that can prevent bloom from occurring regardless of the storage environment and can perform stable transfer over a long period of time.

FIG. 3 is a schematic diagram of a main part showing an example of a configuration of an image forming apparatus in which a plurality of photosensitive drums are arranged in parallel along one intermediate transfer belt formed of a seamless belt according to the present invention.

  As an embodiment for carrying out the present invention, the intermediate transfer belt includes at least an elastic layer. However, in consideration of mechanical characteristics, an elastic layer is formed on a base layer having a high mechanical strength, and resin particles are further formed thereon. A structure having a layer (hereinafter referred to as a resin particle layer) having releasability from the toner using a toner is preferable.

(Base layer)
The resin of the base layer is preferably a fluorine-based resin such as PVDF or ETFE, a polyimide resin or a polyamide-imide resin in consideration of, for example, flame retardancy, and particularly from the viewpoint of mechanical strength (high elasticity) and heat resistance. A polyimide resin or a polyamideimide resin is preferred. Examples of the electrical resistance adjusting material include metal oxide, carbon black, ionic conductive agent, and conductive polymer material.

  Examples of the metal oxide include zinc oxide, tin oxide, titanium oxide, zirconium oxide, aluminum oxide, and silicon oxide. Moreover, in order to improve dispersibility, the metal oxide may be subjected to surface treatment in advance.

  Examples of carbon black include ketjen black, furnace black, acetylene black, thermal black, and gas black.

  Examples of the ionic conductive agent include tetraalkylammonium salts, trialkylbenzylammonium salts, alkylsulfonates, alkylbenzenesulfonates, alkyl sulfates, glycerol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acids. Alcohol ester, alkyl betaine, lithium perchlorate, etc. are mentioned, and these may be used in combination.

The electrical resistance adjusting material is preferably in an amount of 1 × 10 ⁸ to 1 × 10 ¹³ Ω / □ in terms of surface resistance and 1 × 10 ⁶ to 1 × 10 ¹² Ω · cm in terms of volume resistance. It is necessary to select and add an amount in a range where the molded film is brittle and does not easily break from the surface. That is, when the base layer of the intermediate transfer belt is used, an electrical property (surface) is obtained by using a base layer coating liquid in which the blending of the resin component (for example, polyimide resin, polyamideimide resin, etc.) and the electrical resistance adjusting material is appropriately adjusted. It is preferable to manufacture and use a base layer having a balance between resistance and volume resistance) and mechanical strength.

(Elastic layer)
Various rubbers and elastomers can be used for the elastic layer. Specifically, acrylic rubber, nitrile hydroxide rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, epihalohydrin rubber, fluorine rubber, silicone rubber, polyolefin elastomer, polyester elastomer, polyurethane elastomer, polyamide elastomer, polyethylene vinyl acetate A copolymer etc. are mentioned. Moreover, it is necessary to adjust suitably with an electrical resistance adjusting material similarly to the said base layer from which electrical resistance changes with kinds of rubber | gum or resin.
Among these, acrylic rubber and hydrogenated nitrile rubber are preferable from the viewpoint of obtaining characteristics required for paper followability such as hardness, elastic modulus, and creep characteristics.

In the present invention, the content of the fatty acid in the intermediate transfer belt is preferably 0.005% by mass to 0.020% by mass with respect to 100% by mass of the elastic layer component. If the content of the fatty acid exceeds 0.020% by mass, the fatty acid bloom may occur over time. On the other hand, when the amount is less than 0.005% by mass, followability to the uneven paper cannot be obtained, and transferability is deteriorated.
The fatty acid is preferably added as a lubricant to the elastic layer and melted at the temperature of rubber kneading, and examples thereof include lauric acid, myristic acid, palmitic acid, and stearic acid.
When different types of fatty acids are mixed, the melting point is lower than that of a single type. Therefore, it is preferable that two or more types of fatty acids exist in the elastic layer. In the present invention, it is most preferable to use stearic acid and palmitic acid in combination.

Here, the content of the fatty acid can be measured, for example, as follows.
(1) The produced intermediate transfer belt is cut into 1 cm × 1 cm, and each is immersed in methanol for 3 hours in a sealed container with a lid closed, and fatty acids are extracted from the elastic layer of each intermediate transfer belt.
(2) In order to carry out methyl esterification of fatty acid, methanolic hydrochloric acid is added to the container, and the lid is closed again and heated at 80 ° C. for 2 hours.
(3) Gas chromatograph mass spectrometry (hereinafter referred to as GC-MS) measurement of the obtained solution is performed. The GC-MS measurement can be performed in a total ion mode in order to identify fatty acids in the solution using GC-MS2010 (manufactured by Shimadzu Corporation), and the ions to be used can be selected. In this case, ions are selected and fatty acids are quantified in a SIM (Selected ion monitor) mode.
A calibration curve is created from the chromatogram area in the SIM mode using a reagent corresponding to the detected fatty acid (for example, in the case of stearic acid, a stearic acid reagent having a purity of 99% or more).
(4) The content of fatty acid in the extract of the intermediate transfer belt can be obtained from the created calibration curve, and the fatty acid content (mass%) relative to 100 parts by mass of the elastic layer component can be calculated from this value.

  The fatty acid content of the intermediate transfer belt can be controlled, for example, by adjusting the heating temperature and the heating time in the heat treatment step in the method for producing the intermediate transfer belt described later.

  If the thickness of the elastic layer is too thin, the unevenness transfer property to the paper is not improved, and is preferably 50 μm or more, and more preferably 100 μm or more. In consideration of pressurization with a roller, 500 μm or less is preferable.

(Resin particle layer)
The surface of the elastic layer preferably contains resin particles. The material of the resin particles is not particularly limited, and examples thereof include spherical particles mainly composed of resins such as acrylic resin, melamine resin, polyamide resin, polyester resin, silicone resin, and fluorine resin. Further, the surface of particles made of these resin materials may be subjected to surface treatment with a different material. “Included on the surface of the elastic layer” means that the resin particles are embedded in at least a part of the surface of the elastic layer, and a part of the resin particles may be exposed.
Further, the resin particles referred to here include a rubber material. A structure in which the surface of spherical particles made of a rubber material is coated with a hard resin is also applicable. Moreover, it may be hollow or porous.

Among these resins, silicone resin particles are most preferred as those having a slipperiness and a high function capable of imparting releasability to toner and abrasion resistance.
It is preferable that the resin is a particle formed into a spherical shape by a polymerization method or the like using these resins. In the present invention, a particle closer to a true sphere is more preferable. Silicone resin particles suitable for use in the present invention are commercially available, and examples include trade name: Tospearl (manufactured by Momentive Performance Materials).

(Method for manufacturing intermediate transfer belt)
The method for producing an intermediate transfer belt of the present invention is a method for producing the intermediate transfer belt of the present invention, which preferably includes at least an elastic layer forming step and a heat treatment step, and preferably includes a base layer forming step. According to other steps.

<Base layer forming step>
The base layer forming step is a step of forming a base layer using a base layer coating solution, and is not particularly limited and can be appropriately selected depending on the purpose.

<Elastic layer formation process>
The elastic layer forming step is a step of forming an elastic layer having spherical fine particles on the surface by applying resin particles as necessary after applying an elastic layer coating liquid containing an elastic layer material on the base layer. There are the following elastic layer forming treatment and elastic layer surface forming treatment.

An example of the elastic layer coating solution is shown below.
Knead rubber with a kneader, add lubricant and flame retardant, and knead further. After cooling with a roll, a vulcanizing agent and a vulcanization aid are added and further kneaded. As the lubricant, fatty acids can be used, and those that melt at the temperature of rubber kneading are preferred. Two or more types of lubricants are heated and melted to form a mixture, which is then allowed to stand at room temperature and used as a powder. The kneaded rubber, solvent, conductive agent and leveling agent are added to the planetary mixer and stirred to obtain a rubber coating solution.

-Elastic layer formation treatment-
There is no restriction | limiting in particular as said elastic layer formation process, According to the objective, it can select suitably, For example, the method of forming an elastic layer on the said base layer by injection molding, extrusion molding, etc., The material which forms an elastic layer And a method of applying an elastic layer coating solution containing the above-mentioned base layer to form an elastic layer.

An example of the formation process of the elastic layer will be specifically described.
While slowly rotating the endless base layer fitted with a cylindrical metal mold, the coating liquid containing the material that forms the elastic layer is uniformly applied to the entire outer surface of the cylinder with a liquid supply device such as a nozzle or dispenser. And then cast (form a coating). Thereafter, the rotation speed is increased to a predetermined speed, and when the predetermined speed is reached at a desired time, the rotation speed is maintained at a constant speed, the rotation is continued, and the elastic layer is formed by sufficiently leveling. During the rotation, heating may be performed as necessary.

-Surface treatment of elastic layer-
The formation process of the surface of the said elastic layer can be used as needed. As the formation process of the surface of the elastic layer, after applying resin particles to the elastic layer of the belt in which the base layer and the elastic layer are laminated by the formation process of the elastic layer, and forming a uniform uneven shape on the surface of the elastic layer, Examples include a method of curing by heating at a predetermined temperature and a predetermined time while rotating.

<Heat treatment process>
The heat treatment step is a step of heating after vulcanizing the elastic layer. The heat treatment is sometimes referred to as post-cure treatment.

The fatty acid content of the intermediate transfer belt can be controlled by adjusting the heating temperature and heating time in the heat treatment step. There are no particular restrictions on the heating conditions in the heat treatment step, but the deterioration temperature varies depending on the type of rubber in the elastic layer, so it is necessary to set the post cure temperature and time according to the material. When the post-cure temperature is lowered, it is necessary to increase the post-cure time.
For example, when stearic acid is used as the fatty acid to be used, it is preferable to post-cure at 150 ° C. or higher in consideration of weight reduction. However, at 150 ° C., it takes time to reduce the weight of the mixed fatty acid. It is preferable to carry out at 2 degreeC for 2 hours or more.

  ADVANTAGE OF THE INVENTION According to this invention, the addition method of the fatty acid which a fatty acid tends to melt | dissolve during processing for a short time and lower temperature, and is easy to decompose | disassemble and lose | disappear at a postcure temperature can be provided. Specifically, fatty acids that are lubricants are mixed and used, making it difficult to cause crystallization of fatty acids so that the fatty acids are easily melted during processing and easily decomposed and lost at the post-cure temperature. Is mentioned. Therefore, since the processing can be performed at a lower temperature for a shorter time, an intermediate transfer belt with less resistance fluctuation due to energization can be obtained.

(Image forming device)
An example of a configuration of a four-drum digital color printer including four photosensitive drums for forming toner images of four different colors (black, yellow, magenta, and cyan) is shown.

  In FIG. 1, the printer main body 1 includes an image writing unit 12, an image forming unit 13, and a paper feeding unit 14 for performing color image formation by electrophotography. Based on the image signal, the image processing unit converts the image into black (BK), magenta (M), yellow (Y), and cyan (C) color signals for image formation and transmits them to the image writing unit 12. To do. The image writing unit 12 is a laser scanning optical system including, for example, a laser light source, a deflector such as a rotary polygon mirror, a scanning imaging optical system, and a mirror group. Image writing corresponding to each color signal is performed on image carriers (photoconductors) 21BK, 21M, 21Y, and 21C that have a writing optical path and are provided for each color of the image forming unit.

  The image forming unit 13 includes photoconductors 21BK, 21M, 21Y, and 21C that are image carriers for black (BK), magenta (M), yellow (Y), and cyan (C). As each photoconductor for each color, an OPC photoconductor is usually used. The transfer belts 22 of the photoconductors 21BK, 21M, 21Y, and 21C are arranged around the primary transfer biases of the photoconductors 21BK, 21M, 21Y, and 21C. Development unit 20BK, 20M, 20Y, 20C for each color of exposure unit, black, magenta, yellow, cyan, primary transfer bias rollers 23BK, 23M, 23Y, 23C as primary transfer means, cleaning device (not shown), In addition, a photosensitive member neutralizing device and the like (not shown) are provided. The developing devices 20BK, 20M, 20Y, and 20C use a two-component magnetic brush developing system. The toner images of the respective colors formed on the respective photoreceptors are sequentially superimposed and transferred while being interposed between the intermediate rollers 23BK, 23M, 23Y, and 23C, which are belt constituent portions.

  On the other hand, the transfer paper P is fed from the paper feed unit 14 and then carried by the transfer conveyance belt 50, which is a belt component, via the registration roller 16. When the intermediate transfer belt 22 and the transfer conveyance belt 50 come into contact, the toner image transferred onto the intermediate transfer belt 22 is subjected to secondary transfer (collective transfer) by a secondary transfer bias roller 60 as a secondary transfer unit. ) As a result, a color image is formed on the transfer paper P. The transfer paper P on which the color image is formed is conveyed to the fixing device 15 by the transfer conveying belt 50, and after the image transferred by the fixing device 15 is fixed, it is discharged out of the printer main body.

  The residual toner that is not transferred during the secondary transfer and remains on the intermediate transfer belt 22 is removed from the intermediate transfer belt 22 by the belt cleaning device 25. A lubricant application device (not shown) is disposed on the downstream side of the belt cleaning device 25. This lubricant application device includes a solid lubricant and a conductive brush that rubs the intermediate transfer belt 22 to apply the solid lubricant. The conductive brush is in constant contact with the intermediate transfer belt 22 and applies a solid lubricant to the intermediate transfer belt 22. The solid lubricant has an effect of improving the cleaning property of the intermediate transfer belt 22, preventing the occurrence of filming, and improving the durability.

  Examples of the lubricant include zinc stearate, calcium stearate, zinc palmitate, zinc laurate and the like, and examples of the higher fatty acid include stearic acid, palmitic acid, lauric acid, and the like, and fatty acid metal salts are preferable. Is most preferably zinc stearate.

  Further, a position detection mark (not shown) is provided on the outer peripheral surface or inner peripheral surface of the intermediate transfer belt 22. However, on the outer peripheral surface side of the intermediate transfer belt 22, it is necessary to devise a position detection mark so as to avoid the passing area of the belt cleaning device 25, which may be difficult to arrange. A position detection mark may be provided on the inner peripheral surface side of the intermediate transfer belt 22. The optical sensor 28 as a mark detection sensor is provided at a position between the secondary transfer bias roller 60 and the belt driving roller 24. Position detection is performed by detecting light reflection from the surface of the intermediate transfer belt. Therefore, detection becomes unstable when the glossiness of the surface of the intermediate transfer belt decreases or becomes non-uniform. By using the intermediate transfer belt of the present invention, it is possible to suppress a decrease in surface glossiness and to stabilize detection.

  The seamless belt according to the present invention can be suitably applied to the intermediate transfer belt 22 or the intermediate transfer belt type image forming apparatus equipped with the intermediate transfer belt 22 as described above. The present invention can also be applied to a transfer / conveying belt type image forming apparatus equipped with a belt. Further, in the case of an image forming apparatus using a transfer / conveying belt system, the present invention can be applied to either the 1-photosensitive drum system or the 4-photosensitive drum system.

  The intermediate transfer belt is preferably an endless belt, that is, a seamless belt. The peripheral length of the intermediate transfer belt when the intermediate transfer belt is an endless belt is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1,000 mm or more, preferably 1,100 mm to 3, 000 mm is more preferable.

  EXAMPLES Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited by these examples, and these examples are appropriately modified without departing from the gist of the present invention. Is also within the scope of the present invention.

  An elastic layer coating solution described below was prepared, and an elastic layer was laminated on the base layer using this coating solution, and then dried at 100 ° C. to apply the resin particles so as to form a single particle layer. After vulcanization at 1 ° C. for 1 hour, post-cure under the following conditions was performed to obtain an intermediate transfer belt.

(Elastic layer material used in Examples)
<Acrylic rubber>
100 parts acrylic rubber (manufactured by Nippon Zeon Co., Ltd., trade name: NipolAR12)
Hexanediamine carbamate 0.6 parts (Dupon, product name: Diak No. 1)
DBU 0.6 parts (Vulcofac, trade name: ACT55)
10 parts of red phosphorus (Rin Chemical Industry Co., Ltd., trade name: Nova Excel)
60 parts of aluminum hydroxide (manufactured by Showa Denko KK, Hijilite H42M)
Tetrabutylammonium perchlorate 0.1 part (Nippon Carlit Co., Ltd., QAP-01)
Solvent (Kyowa Hakko Co., Ltd., 2-heptanone)
Palmitic acid (trade name: Palmitic acid, manufactured by Wako Pure Chemical Industries, Ltd.)
Stearic acid (manufactured by Hiroshima Wako, trade name: stearic acid)
Lauric acid (trade name: stearic acid, manufactured by Wako Pure Chemical Industries, Ltd.)
In addition, about palmitic acid, stearic acid, and lauric acid, it mix | blended like the Example and comparative example which are mentioned later.

<Hydrogenated nitrile rubber>
100 parts of hydrogenated nitrile rubber (manufactured by Nippon Zeon Co., Ltd., trade name: Zettopol 2020L)
Sulfur 1 part (Tsurumi Chemical Co., Ltd., trade name: 200 mesh sulfur)
Zinc oxide 5 parts (manufactured by Shodo Chemical Industry Co., Ltd., trade name: Zinc Hana)
Tetramethylthiuram monosulfide 0.5 parts (Ouchi Shinsei Chemical Co., Ltd., trade name: Noxeller TS)
10 parts of red phosphorus (Rin Chemical Industry Co., Ltd., trade name: Nova Excel)
40 parts of aluminum hydroxide (manufactured by Showa Denko KK, Hijilite H42M)
Solvent (Kyowa Hakko Co., Ltd., 2-butanone)
Palmitic acid (trade name: Palmitic acid, manufactured by Wako Pure Chemical Industries, Ltd.)
Stearic acid (manufactured by Hiroshima Wako, trade name: stearic acid)
In addition, about palmitic acid and stearic acid, it mix | blended like the Example and comparative example which are mentioned later.

The above vulcanized rubber was post-cured under the following conditions.
<Example 1>
Acrylic rubber was used as the elastic layer, and 0.25 part of stearic acid and 0.75 part of palmitic acid were used as the lubricant. Before adding the processing aid to the rubber, the processing aid was mixed and heated to form a solid at room temperature before use. Post cure was performed at 170 ° C. for 3 hours.

<Example 2>
Acrylic rubber was used as the elastic layer, and 0.75 parts of stearic acid and 0.25 parts of palmitic acid were used as the lubricant. Before adding the processing aid to the rubber, the processing aid was mixed and heated to form a solid at room temperature before use. Post cure was performed at 170 ° C. for 3 hours.

<Example 3>
Acrylic rubber was used as the elastic layer, and 0.7 part of stearic acid, 0.2 part of palmitic acid and 0.1 part of lauric acid were used as the lubricant. Before adding the processing aid to the rubber, the processing aid was mixed and heated to form a solid at room temperature before use. Post cure was performed at 170 ° C. for 3 hours.

<Example 4>
Hydrogenated nitrile rubber was used as the elastic layer, and 0.25 part of stearic acid and 0.75 part of palmitic acid were used as the lubricant. Before adding the processing aid to the rubber, the processing aid was mixed and heated to form a solid at room temperature before use. Post cure was performed at 170 ° C. for 3 hours.

<Example 5>
Acrylic rubber was used as the elastic layer, and 0.25 part of stearic acid and 0.75 part of palmitic acid were used as the lubricant. Before adding the processing aid to the rubber, the processing aid was mixed and heated to form a solid at room temperature before use. Post cure was performed at 180 ° C. for 2 hours.

<Comparative Example 1>
Acrylic rubber was used as the elastic layer, and 1 part of palmitic acid was used as the lubricant. Post cure was performed at 170 ° C. for 3 hours.

<Comparative example 2>
Acrylic rubber was used as the elastic layer and 1 part of stearic acid was used as the lubricant. Post cure was performed at 170 ° C. for 3 hours.

<Comparative Example 3>
Acrylic rubber was used as the elastic layer, and 1 part of lauric acid was used as the lubricant. Post cure was performed at 170 ° C. for 3 hours.

<Comparative example 4>
Hydrogenated nitrile rubber was used as the elastic layer, and 1 part of palmitic acid was used as the lubricant. Post cure was performed at 170 ° C. for 3 hours.

<Comparative Example 5>
Acrylic rubber was used as the elastic layer, and 1 part of palmitic acid was used as the lubricant. Post cure was performed at 170 ° C. for 5 hours.

<Comparative Example 6>
Acrylic rubber was used as the elastic layer, and 1 part of palmitic acid was used as the lubricant. Post cure was performed at 180 ° C. for 4 hours.

≪Fatty acid measurement method≫
<Fatty acid extraction>
(1) The intermediate transfer belts of Examples 1 to 5 and Comparative Examples 1 to 6 were cut out, and each was immersed in methanol for 3 hours in a sealed container with the lid closed, and the fatty acid in the elastic layer was extracted. It was.
(2) In order to perform methyl esterification, hydrochloric acid methanol was added to the test tube, and the lid was closed again and heated for 2 hours.
(3) GC-MS measurement of the above solution was performed. In the measurement, GC-MS2010 (manufactured by Shimadzu Corporation) was used. GC-MS measurement was performed in total ion mode to identify fatty acids in the solution, and the ions to be used were selected. A calibration curve was created from the area of the chromatogram in the SIM mode using the detected fatty acid reagent. Ions were selected and quantified in SIM mode.
(4) The amount of fatty acid per rubber weight was calculated.

<Bloom acceleration evaluation>
For the acceleration evaluation of bloom, the intermediate transfer belt was cut out, stored at 90% humidity and 45 ° C. for 1 day, immersed in water, and then visually checked for bloom.

<Electrical fatigue assessment>
Using a Hiresta UP MCP-HT450 (manufactured by Dia Instruments Co., Ltd.), the amount of resistance fluctuation after 300 times of application was measured with 1000V applied for 60 seconds and 10 seconds of standby as one time.
The initial value and the amount of resistance fluctuation after fatigue were allowed to be less than 0.8 (Log Ω · cm), and 0.8 (Log Ω · cm) or more were made impossible.

Table 1 shows the results of the above measurements for the above examples. Similarly, Table 2 shows the results of the above measurement results for the comparative example.
Examining Table 1 and Table 2, it can be seen that the results of Bloom acceleration evaluation are good in Examples 1 to 5 and Comparative Examples 5 and 6. Moreover, as for the result of electrical conduction fatigue evaluation, it turns out that Examples 1-5 and Comparative Examples 1-4 are favorable.
Therefore, according to the present invention, it is possible to provide an intermediate transfer belt which does not generate bloom and can perform stable transfer over a long period of time.

P Transfer paper 10 Printer body 12 Image writing unit 13 Image forming unit 14 Paper feeding unit 15 Fixing device 16 Registration roller 20BK, 20M, 20Y, 20C Developing device 21BK, 21M, 21Y, 21C Photoconductor 22 Intermediate transfer belt 23BK, 23M , 23Y, 23C Primary transfer bias roller 24 Drive roller 25 Belt cleaning device 27 Belt cleaning member 50 Transfer conveyance belt 60 Secondary transfer bias roller

JP 2006-091497 A JP 2004-198713 A

Claims (7)

  In the intermediate transfer belt having an elastic layer, the amount of the fatty acid contained in the elastic layer is 0.005% by mass to 0.020% by mass with respect to the weight of the elastic layer, and two or more types of the fatty acid are present. An intermediate transfer belt characterized by   The intermediate transfer belt according to claim 1, wherein the fatty acid is stearic acid and palmitic acid.   The intermediate transfer belt according to claim 1, wherein the elastic layer is acrylic rubber.   The intermediate transfer belt according to claim 1, wherein resin particles are included on a surface of the elastic layer.   5. The intermediate transfer belt according to claim 1, wherein the intermediate transfer belt is a seamless belt.   An image forming apparatus comprising the intermediate transfer belt according to claim 1. A method for producing an intermediate transfer belt according to any one of claims 1 to 5,
A step of applying an elastic layer coating liquid containing an elastic layer material containing a fatty acid on the base layer, and a heat treatment step of heating the elastic layer,
By adjusting the temperature and time of the heat treatment step, the amount of fatty acid contained in the elastic layer is controlled to be 0.005% by mass to 0.020% by mass with respect to the weight of the elastic layer. A method for producing an intermediate transfer belt, which is characterized.

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