JP2018060016A - Intermediate transfer belt, transfer unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer belt that suppresses a reduction in cleanability after image formation is repeated.SOLUTION: An intermediate transfer belt has a plurality of concave parts with the major axis in a belt axial direction. The plurality of concave parts have an average major axis of 20 μm or more and 1000 μm or less; the plurality of concave parts have an average minor axis of 3 μm or more and 800 μm or less; the concave part has an abundance of 1/mmor more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intermediate transfer belt, a transfer unit, and an image forming apparatus.

For example, Patent Document 1 discloses a belt-shaped transfer material carrier that carries a transfer material onto which a toner image on an image carrier is transferred, and carries the transfer material when used for carrying the transfer material. There is disclosed a transfer material carrier characterized in that a coating layer is provided on the surface so that the width of a crack generated on the surface is equal to or less than the size of the deposit attached to the surface.
In Patent Document 2, in an endless transfer belt that is used in an electrophotographic image forming apparatus and is rotationally driven when a toner image is transferred, at least an elastic layer and a surface layer harder than the elastic layer are provided on the inner side. Are stacked in this order from the surface facing the final medium to the outside facing the final medium, and at least the area of the surface layer that can be in contact with the final medium as viewed in the width direction of the transfer belt. A plurality of grooves having an angle of 45 degrees or less with respect to the direction are formed at intervals in the width direction of the transfer belt, and the interval is 10 mm or less at the longest. It is disclosed.

JP 2005-284320 A JP 2014-219505 A

In the intermediate transfer belt having a plurality of recesses having a major axis in the belt axial direction, the present invention has an average major axis of the plurality of recesses of less than 20 μm, an average minor axis of the plurality of recesses of less than 3 μm, or It is an object of the present invention to provide an intermediate transfer belt that suppresses deterioration in cleaning properties after repeated image formation as compared with a case where the existence ratio of the recesses is less than 1 piece / mm ² .

In order to achieve the above object, the following means are provided.
The invention according to claim 1
A plurality of recesses having a major axis in the belt axis direction, wherein the average major axis of the plurality of recesses is 20 μm or more and 1000 μm or less, and the average minor axis of the plurality of recesses is 3 μm or more and 800 μm or less; Is an intermediate transfer belt of 1 piece / mm ² or more.

The invention according to claim 2
The intermediate transfer belt according to claim 1, wherein an average depth of the plurality of recesses is 1 μm or more and 5 μm or less.

The invention according to claim 3
The intermediate transfer belt according to claim 1, comprising a thermoplastic resin.

The invention according to claim 4
The intermediate transfer belt according to claim 3, wherein the thermoplastic resin is a polyetherimide and a siloxane-modified polyetherimide.

The invention according to claim 5
The intermediate transfer belt according to claim 3 or 4, wherein the intermediate transfer belt is a tubular extruded product.

The invention according to claim 6
The intermediate transfer belt according to any one of claims 1 to 5,
A plurality of rolls that hang the intermediate transfer belt in a tensioned state;
And a transfer unit that is detachable from the image forming apparatus.

The invention according to claim 7 provides:
An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing a latent image on the surface of the image carrier with toner to form a toner image;
The intermediate transfer belt according to any one of claims 1 to 5,
Primary transfer means for primarily transferring the toner image formed on the surface of the image carrier onto the outer peripheral surface of the intermediate transfer belt;
Secondary transfer means for secondary transfer of the toner image primarily transferred to the outer peripheral surface of the intermediate transfer belt to a recording medium;
Fixing means for fixing the toner image secondarily transferred to the recording medium;
Cleaning means comprising a cleaning blade for removing toner remaining on the surface of the intermediate transfer belt;
An image forming apparatus.

According to the first, third, fourth, or fifth aspect of the present invention, in the intermediate transfer belt having a plurality of recesses having a major axis in the belt axial direction, the average major axis of the plurality of recesses is less than 20 μm. Provided is an intermediate transfer belt that suppresses deterioration in cleaning properties after repeated image formation as compared with a case where the average minor axis is less than 3 μm or a case where the existence ratio of the recesses is less than 1 piece / mm ^2. .

  According to the second aspect of the present invention, there is provided an intermediate transfer belt that suppresses deterioration in cleaning properties after repeated image formation as compared with the case where the average depth of the plurality of recesses exceeds 5 μm.

According to the invention of claim 6 or 7, when an intermediate transfer belt having a plurality of recesses having a major axis in the belt axis direction and having an average major axis of the plurality of recesses of less than 20 μm is applied, Compared to the case where an intermediate transfer belt having an average minor axis of recesses of less than 3 μm is applied, or the case where an intermediate transfer belt having an existence ratio of recesses of less than 1 piece / mm ² is applied, after image formation is repeated. Provided is a transfer unit or an image forming apparatus that suppresses a decrease in cleaning performance.

It is a photograph which shows the major axis and minor axis of a crevice observed by SEM. It is a figure which shows the depth of the recessed part measured with the laser microscope. FIG. 3 is a schematic perspective view illustrating an example of an intermediate transfer belt according to the present embodiment. It is a schematic perspective view which shows an example of the transfer unit which concerns on this embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Hereinafter, an embodiment which is an example of the present invention will be described with reference to the accompanying drawings. In the following description, reference numerals may be omitted.

[Intermediate transfer belt]
The intermediate transfer belt according to the present embodiment has a plurality of recesses having a major axis in the belt axis direction, the average major axis of the plurality of recesses is 20 μm or more and 1000 μm or less, and the average minor axis of the plurality of recesses is 3 μm or more. It is 800 μm or less, and the existence ratio of the recesses is 1 piece / mm ² or more.
The intermediate transfer belt according to the present embodiment has a plurality of recesses having a long diameter in the belt axis direction on the surface thereof, but this does not exclude the presence of a recess having no long diameter in the belt axis direction. However, the recesses present on the belt surface are preferably recesses having a major axis in the belt axis direction. Specifically, 60% or more of the recesses present on the belt surface are recesses having a major axis in the belt axis direction. More preferably, 80% or more of the recesses have a major axis in the belt axis direction.

Here, in the intermediate transfer type image forming apparatus, the toner image formed on the image carrier is primarily transferred to the intermediate transfer belt and then secondarily transferred from the intermediate transfer belt to the recording medium. After the secondary transfer, the toner remaining on the surface of the intermediate transfer belt may be scraped off (cleaned) by a cleaning blade.
However, in an intermediate transfer type image forming apparatus, when an image is repeatedly formed, cracks in the axial direction may occur on the surface of the intermediate transfer belt (hereinafter also simply referred to as “belt surface”).
When cracks occur on the belt surface, residual toner (particularly external additives) is easily embedded in the cracks. The residual toner embedded in the crack is not easily scraped by the cleaning blade, and the residual toner accumulates inside the crack. As a result, the cleaning blade becomes slippery in this accumulation portion, and the cleaning property can be maintained. The image quality was poor due to the sliding of the cleaning blade.

  Further, in a secondary transfer type image forming apparatus, a decrease in cleaning property due to repeated image formation is more likely to occur in a low-temperature, low-humidity environment (for example, 10 ° C., 15% RH environment). This is considered to be because the cleaning blade becomes hard in a low temperature and low humidity environment, and the followability to the belt surface tends to decrease.

In contrast, the intermediate transfer belt according to the present embodiment has a plurality of recesses having a major axis in the belt axial direction, and the average major axis and the minor minor axis of the plurality of recesses are controlled to a specific size. Further, the existence ratio of the recesses is controlled to be 1 piece / mm ² or more.
Thereby, the deterioration of the cleaning property after repeating the image formation is suppressed. The reason is not clear, but is thought to be due to the following reasons.
First, the average major axis and average minor axis of the plurality of recesses being in the above range is an indicator that the size of the recesses is relatively large. Specifically, the size of a crack generated on the belt surface by repeatedly forming an image is, for example, about 5 μm to 15 μm in the major axis and about 1 μm to less than 3 μm in the minor axis. The average major axis and the average minor axis of the recesses on the surface are larger than this.
Further, the presence ratio of the recesses of 1 piece / mm ² or more is an indicator that a relatively large number of recesses having a major axis in the belt axial direction exist on the belt surface.
In other words, it can be said that the intermediate transfer belt according to the present embodiment is an intermediate transfer belt in which a concave portion relatively larger than a crack generated by repeatedly forming an image is formed on the surface in advance.

In the intermediate transfer belt according to the present embodiment, the plurality of recesses have the average major axis and the average minor axis (the recesses are relatively large) and have a major axis in the belt axial direction, so the cleaning blade is pressed against the belt surface. When the residual toner is scraped off, the cleaning blade easily enters the concave portion of the belt surface and easily follows the concave portion shape.
Here, the residual toner may be embedded in the concave portion of the belt surface, but the residual toner in the concave portion is easily scraped off by causing the cleaning blade to enter the concave portion. As a result, the cleaning performance is easily maintained even after the image formation is repeated, and the accumulation of residual toner inside the concave portion is suppressed, and as a result, the cleaning blade slipping that occurs in the residual toner accumulation portion is less likely to occur.
Further, in the intermediate transfer belt having the concave portion, the stress during driving of the belt tends to concentrate on the concave portion. Therefore, even if a crack occurs on the belt surface due to repeated image formation, the crack is not located on the belt surface. Instead, it is considered that it is likely to be formed inside the recess. As a result, the occurrence of cracking that makes it difficult to scrape the residual toner with the cleaning blade is suppressed at places other than the recesses on the belt surface. The sliding of the cleaning blade is suppressed. That is, even if a crack occurs on the belt surface, it is difficult to affect the deterioration of the cleaning property.
Further, in the intermediate transfer belt according to the present embodiment, the existence ratio of the concave portions is 1 piece / mm ² or more, and a relatively large number of the concave portions are present on the belt surface. Occurrence of cracks is suppressed satisfactorily, and this also suppresses deterioration of the cleaning property.
From the above, according to the intermediate transfer belt according to the present embodiment, it is possible to suppress a decrease in cleaning performance after repeated image formation.
Furthermore, according to the intermediate transfer belt according to the present embodiment, it is possible to suppress a decrease in cleaning properties after repeated image formation even in a low temperature and low humidity environment.

  In addition, a transfer belt having only a plurality of concave portions having a major axis in a direction (belt circumferential direction) orthogonal to the belt axis direction has been proposed (for example, Patent Document 2 described above). Cleaning properties after repeated formation are difficult to ensure. This is because the concave portion is formed to have a long diameter in the belt circumferential direction, and when the cleaning blade is pressed against the belt surface and the residual toner is scraped off, the cleaning blade hardly enters the concave portion on the belt surface. This is thought to be because it is difficult to follow the shape.

The intermediate transfer belt according to the present embodiment has a plurality of recesses having a long diameter in the belt axial direction.
Here, the “belt axial direction” refers to a direction that is the axial direction of a roll when the belt is wound around a plurality of rolls.
Further, “having a major axis in the belt axis direction” means that the major axis exists in a direction where the angle (acute angle) with respect to the “belt axis direction” is 40 ° or less (preferably 30 ° or less).
The major axis of the recess refers to the longest portion and the length of the opening surface of the recess.
The minor axis of the recess refers to the longest part and its length in the direction orthogonal to the major axis.
The depth of the recess refers to the distance from the opening surface of the recess to the deepest portion of the recess.

FIG. 1 is a photograph showing a major axis and a minor axis of a recess observed with an SEM. In FIG. 1, the “belt circumferential direction” refers to a direction orthogonal to the belt axial direction.
FIG. 2 is a diagram showing the depth of the recesses measured by a laser microscope.
In addition, the shape of a recessed part is not specifically limited.

  In the intermediate transfer belt according to the present embodiment, from the viewpoint of suppressing deterioration in cleaning properties after repeated image formation, the average major axis of the concave part, the average minor axis of the concave part, the presence ratio of the concave part, and the average depth of the concave part Preferred ranges are as follows.

-Average major axis of recess-
The average major axis of the recesses is 20 μm or more and 1000 μm or less, preferably 40 μm or more and 800 μm or less.
When the average major axis of the recesses is 20 μm or more, the cleaning blade easily enters the recesses on the belt surface and easily follows the shape of the recesses.
When the average major axis of the recesses is 1000 μm or less, the sliding of the blade due to the cracks generated in the recesses is suppressed, and cleaning maintainability is obtained.

-Average minor axis of recess-
The average minor axis of the recess is 3 μm or more and 800 μm or less, preferably 10 μm or more and 400 μm or less, more preferably 15 μm or more and 100 μm or less.
If the average minor axis of the recesses is 3 μm or more, the residual toner in the recesses is easily scraped off by the cleaning blade.
When the average minor axis of the recesses is 800 μm or less, the sliding of the blade due to the cracks generated in the recesses is suppressed, and cleaning maintainability is obtained.

-Ratio of recesses-
The existence ratio of the recesses is 1 piece / mm ² or more, preferably 3 pieces / mm ² or more.
When the presence ratio of the recesses is 1 piece / mm ² or more, the occurrence of cracks at locations other than the recesses on the belt surface is easily suppressed favorably.
The area ratio of the region occupied by the recesses on the belt surface (where the cleaning blade comes into contact) is preferably 60% or less, more preferably 45% or less, and even more preferably 30% or less.
When the area ratio of the area occupied by the recesses on the belt surface is 60% or less, the occurrence of cracks other than the recesses on the belt surface is suppressed, and the cleaning maintainability is improved.

-Average depth of recesses-
The average depth of the recesses is preferably 1 μm or more and 5 μm or less, more preferably 2 μm or more and 4 μm or less.
If the average depth of the recesses is 1 μm or more, cracks that occur during belt running are less likely to occur inside the belt recesses.
When the average depth of the recesses is 5 μm or less, the residual toner in the recesses is easily scraped off by the cleaning blade.

-Measurement of average major axis of recess and average minor axis of recess-
The belt axis direction, one of the 1 mm ² around the position spaced 50mm from the side area, 1 mm ² area centered on the position spaced 50mm from the other side, 1 mm ² region of the belt center, against further the region , Regions that are 120 ° apart from each other in the circumferential direction are specified. Observe the surface of the recesses in the specified 9 regions (however, the recesses having a major axis in the belt axis direction) with a scanning electron microscope (SEM) to take images, and measure the major axis and minor axis of each recess. .
The average major axis of the recess is the average value of the major axis of all the measured recesses, and the average minor axis of the recess is the average value of the minor axis of all the measured recesses.

-Measurement of the existence ratio of recesses and the average depth of recesses-
The above nine areas are observed with a laser microscope to take an image, and the number of concave portions present in the nine areas and the depth of each concave portion are measured.
The presence ratio of the recesses is a value obtained by dividing the number of all recesses existing in the 9 region by the total area (9 mm ² ) of the 9 region.
Let the average depth of a recessed part be the average value of the depth of all the measured recessed parts.
As shown in FIG. 2, the depth of the recess is the difference between the highest peak and the lowest peak of the recess when noise occurs.

In this embodiment, as a method of obtaining an intermediate transfer belt in which the size of the recesses (average major axis and average minor axis (preferably average depth)) and the presence ratio of the recesses are controlled in the above ranges, for example, a thermoplastic resin The intermediate transfer belt is subjected to a process of kneading a thermoplastic resin other than the siloxane-modified resin and a resin material containing the siloxane-modified resin and extruding the resin material into a tubular shape (extruding process) and a process of taking out the extruded resin material (extracting process). Is preferred. In the take-up step, it is preferable to adjust the speed (take-up speed) when taking up the resin material.
In particular, as a thermoplastic resin, a resin material containing polyetherimide (excluding siloxane-modified polyetherimide, the same applies hereinafter) and siloxane-modified resin (preferably siloxane-modified polyetherimide (hereinafter also referred to as “siloxane-modified PEI”)) is used. It is preferable to carry out the extrusion step and the take-up step. This makes it easy to realize an intermediate transfer belt in which deterioration in cleaning properties after image formation is repeated is suppressed.

The reason is not clear, but is thought to be due to the following reasons.
In the step of kneading and extruding the resin material containing polyetherimide and siloxane-modified resin (preferably siloxane-modified PEI) into a tubular shape (extrusion step), the siloxane bond of the siloxane-modified resin is locally decomposed on the surface of the resin material. It is considered that a recess having a relatively small diameter is formed. On the other hand, it is considered that the polyetherimide has high heat resistance and is not easily decomposed, that is, it is difficult to form a recess in a portion where the polyetherimide exists. Then, in the subsequent step of taking out the resin material (take-off step), the concave portion having a relatively small diameter is extended in the axial direction (belt axial direction) of the resin material to form a concave portion having a long diameter in the belt axial direction. It is thought.
It is considered that there are more siloxane-modified resin (preferably siloxane-modified PEI) components in the formed recesses, that is, the recesses formed by decomposition of the siloxane-modified resin (preferably siloxane-modified PEI) and its periphery. A siloxane-modified resin (preferably siloxane-modified PEI) is a relatively soft material compared to a thermoplastic resin such as polybutylene naphthalate or polyphenylene sulfide resin used as a material for an intermediate transfer belt. Due to the presence of many in the recess and its periphery, the stress is relieved even if the stress is concentrated on the recess when the belt is driven. Accordingly, it is considered that even the occurrence of cracks that can occur in the recesses is suppressed, and as a result, the accumulation of residual toner in the recesses is reduced, and the deterioration in cleaning properties is further suppressed.
Further, in the intermediate transfer belt having the above-described configuration, a large amount of the siloxane-modified resin component is present in and around the concave portion, and the siloxane-modified resin (preferably siloxane-modified PEI) has a siloxane chain, so The mold releasability with respect to the external additive is also excellent. Therefore, the accumulation of residual toner in the recess is further reduced.
From the above, in the intermediate transfer having a concave portion formed by decomposing a siloxane-modified resin (preferably siloxane-modified PEI), it becomes easier to suppress a decrease in cleaning property after repeated image formation.

  Further, in the intermediate transfer belt obtained by using polyetherimide and siloxane-modified PEI as the thermoplastic resin, a sea-island structure in which polyetherimide is the sea part and siloxane-modified PEI is the island part is easily formed in the surface layer part. . Due to this characteristic (easy to form sea-island structure), it is considered that the siloxane-modified PEI component is more likely to be present in the recess, and this also facilitates the above effect.

The amount of the siloxane-modified resin component present in the concave portion and its periphery of the intermediate transfer belt and in the portion having no concave portion is measured by FTIR (Fourier transform infrared spectrophotometer). Specifically, the concave portion of the intermediate transfer belt and its peripheral surface are polished with a file, and powder is collected from a region within a range from the surface to a depth of 1 μm to 5 μm (Sample 1). In the same manner as in sample 1, the surface of the portion having no recess is polished with a file to collect powder (sample 2). About the obtained samples 1 and 2, an infrared absorption spectrum is measured using FT / IR-6100 (made by JASCO Corporation).
For example, when the siloxane-modified resin is a siloxane-modified PEI, the amount of the siloxane-modified PEI component present in the recess and its surroundings and in the portion having no recess is determined based on the siloxane skeleton of the siloxane-modified PEI relative to the peak derived from the polyetherimide skeleton. It is calculated from the ratio of the peaks derived from each. By comparing the calculated amount of the siloxane-modified PEI component of Samples 1 and 2, it is confirmed that a larger amount of the siloxane-modified PEI component is contained in the concave portion and the periphery thereof.

  The intermediate transfer belt according to this embodiment is obtained by using a known method, and then using, for example, a brush (such as a brass brush) on the belt surface, the above-described sizes (average major axis and average minor axis ( A recess having an average depth)) and a presence ratio may be formed. Also in this case, the deterioration of the cleaning property after the image formation is repeated is suppressed.

Hereinafter, materials constituting the intermediate transfer belt according to the present embodiment will be described in detail.
FIG. 3 is a schematic perspective view showing an example of the intermediate transfer belt according to the present embodiment.
The intermediate transfer belt 10 shown in FIG. 3 is an endless belt formed of a single layer body.
Further, the intermediate transfer belt 10 shown in FIG. 3 has a plurality of recesses having a major axis in the belt axial direction, the size of the recesses (average major axis and average minor axis (preferably average depth)), and the presence ratio of the recesses. Is controlled within the above range.
The intermediate transfer belt 10 includes, for example, a thermoplastic resin, and may further include a conductive agent and other components.

<Thermoplastic resin>
The thermoplastic resin is not particularly limited, and a general thermoplastic resin used for an intermediate transfer belt can be used. For example, polyphenylene sulfide (PPS), polyamide (PA), polyetheretherketone (PEEK), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysulfone (PES), polyethersulfone (PES), polyetherimide (PEI), liquid crystal polymer (LCP), polyacetal (POM), polycarbonate (PC) and the like. Moreover, what modified | denatured the said thermoplastic resin is applicable. As the thermoplastic resin, only one of the above may be used, or two or more may be used in combination.
The thermoplastic resin preferably contains a polyetherimide from the viewpoint of obtaining scratch resistance and flame retardancy of the belt.
Further, from the viewpoint of controlling the size of the recesses having a major axis in the belt axis direction and the presence ratio of the recesses within the above range, the thermoplastic resin preferably includes both polyetherimide and siloxane-modified resin. The siloxane-modified resin is not particularly limited, and examples thereof include siloxane-modified polyetherimide (siloxane-modified PEI) and siloxane-modified polycarbonate (hereinafter also referred to as “siloxane-modified PC”). Of these, siloxane-modified PEI is preferable.

(Polyetherimide (polyetherimide other than siloxane-modified PEI))
The polyetherimide is a polyetherimide which does not contain a siloxane bond, and is, for example, a resin having a melt moldability containing an aliphatic, alicyclic or aromatic ether unit and a cyclic imide group as repeating units.

  Examples of the polyetherimide include those obtained by a polymerization reaction between a dicarboxylic dianhydride containing an ether bond and a diamine. That is, examples of the polyetherimide include a polyetherimide having at least a repeating unit structure derived from a dicarboxylic dianhydride containing an ether bond and a diamine.

  Examples of the dicarboxylic acid non-hydrate containing an ether bond include 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 4,4′-bis (3,4). Dicarboxyphenoxy) diphenyl ether dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) benzophenone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane dianhydride, 4,4'- Bis (2,3-dicarboxyphenoxy) diphenyl ether dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenyl sulfide 4,4′-bis (2,3-dicarboxyphenoxy) benzophenone dianhydride, 4,4′-bis (2,3-dicarboxyphenoxy) diphenylsulfone dianhydride, 4- (2,3- Dicarboxyphenoxy) -4 '-(3,4-dicarboxyphenoxy) diphenyl-2,2-propane dianhydride, 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxy Phenoxy) diphenyl ether dianhydride, 4- (2,3-dicarboxyphenoxy) -4 '-(3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4- (2,3-dicarboxyphenoxy) -4 '-(3,4-Dicarboxyphenoxy) benzophenone dianhydride and 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxyl Phenoxy) diphenyl sulfone dianhydride, and the like. These dicarboxylic dianhydrides may be used individually by 1 type, and may use together 2 or more types selected among them.

  Examples of the diamine include aliphatic diamines, alicyclic diamines, aromatic diamines, aromatic diamines containing a heterocyclic ring, and the like.

The diamine is not particularly limited as long as it is a diamine compound having two amino groups in the molecular structure.
Examples of the diamine include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3- Trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 4,4′-diaminobenzanilide, 3,5-diamino-3′-trifluoromethylbenzanilide, 3,5-diamino-4′-trifluoromethylbenzanilide, 3,4′-diaminodiphenyl ether, 2,7-di Minofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4' -Diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2, 2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1 , 4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) -biphenyl, 1,3′-bis (4-aminophenoxy) benzene, 9,9-bis (4-a Nophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoro) Aromatic diamines such as methylphenoxy) phenyl] hexafluoropropane, 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; aromatic rings such as diaminotetraphenylthiophene An aromatic diamine having two bonded amino groups and a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octa Methylenediamine, nonamethylenediamine, 4,4-diaminoheptamethyle Diamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene cyclopentadienylide diamine, hexahydro-4,7-meth Noin mite range diamine, tricyclo [6,2,1,0 ^2.7] - undecylenic Examples thereof include aliphatic diamines such as dimethyldiamine and 4,4′-methylenebis (cyclohexylamine), and alicyclic diamines. These diamines may be used alone or in combination of two or more selected from them.

  The polyetherimide contained in the intermediate transfer belt 10 may be a modified polyetherimide other than the siloxane-modified resin described later (for example, cyano-modified polyetherimide, fluorine-containing polyetherimide).

  A commercially available product may be used as the polyetherimide, and examples thereof include ULTEM series such as ULTEM 1000, 1010 and 1100 manufactured by SABIC Innovative Plastics.

(Siloxane modified resin)
The siloxane-modified resin is not particularly limited, and examples thereof include siloxane-modified polyetherimide (siloxane-modified PEI) and siloxane-modified polycarbonate (siloxane-modified PC) as described above.

-Siloxane-modified PEI-
Siloxane-modified PEI is a polyetherimide obtained by modifying polyetherimide with a silicone resin and having a siloxane bond.
Specific examples of the siloxane-modified PEI include siloxane-modified polyetherimide obtained by modifying the above-mentioned polyetherimide with a silicone resin. For example, aromatic bis (ether anhydride), amine-terminated organosiloxane and organic diamine These reactants can be mentioned.
Examples of commercially available siloxane-modified PEI (a copolymer of polyetherimide resin and silicone resin) include SILTEM STM1500, 1600, and 1700 manufactured by SABIC Innovative Plastics.

-Siloxane-modified PC-
Siloxane-modified PC is a polycarbonate obtained by modifying a polycarbonate with a silicone resin and having a siloxane bond.
It does not specifically limit as siloxane modified PC, A well-known thing can be used.

When the intermediate transfer belt 10 includes both polyetherimide and a siloxane-modified resin (preferably siloxane-modified PEI) as the thermoplastic resin, the content of the siloxane-modified resin (preferably siloxane-modified PEI) is included in the intermediate transfer belt 10. 5 parts by mass or more and 50 parts by mass or less are preferable, 8 parts by mass or more and 40 parts by mass or less are preferable, and 10 parts by mass or more and 30 parts by mass or less are more preferable.
Here, “all resins” means all resin components when the intermediate transfer belt 10 includes only polyetherimide and siloxane-modified resin as resin components, and other resins include other resins. Means all resin components including the resin.
When the intermediate transfer belt is a multilayer body, the content of the siloxane-modified resin (preferably siloxane-modified PEI) is at least 100 parts by mass of the total resin contained in the outermost layer (outermost layer). It is preferable that it is the said range with respect to.

<Conductive agent>
The intermediate transfer belt 10 preferably contains a conductive agent.
Examples of the conductive agent include carbon black; metals such as aluminum and nickel; metal oxides such as yttrium oxide and tin oxide; ionic conductive substances such as potassium titanate and potassium chloride; polyaniline, polypyrrole, polysulfone, and polyacetylene. Examples thereof include conductive polymers.
Among these, carbon black is preferable from the viewpoint of conductivity and economy. Carbon black is excellent in conductivity and can impart high conductivity even with a small content.

Examples of the carbon black include ketchen black, oil furnace black, channel black, acetylene black, and carbon black whose surface is oxidized (hereinafter referred to as “surface-treated carbon black”). Of these, surface-treated carbon black is preferable from the viewpoint of electrical resistance stability over time.
The surface-treated carbon black is obtained by adding, for example, a carboxyl group, a quinone group, a lactone group, a hydroxyl group or the like to the surface. Examples of the surface treatment method include an air oxidation method in which a reaction is caused by contact with air in a high temperature atmosphere, a method of reacting with nitrogen oxide or ozone at a normal temperature (for example, 22 ° C.), and air in a high temperature atmosphere. A method of oxidizing with ozone at a low temperature after oxidation is exemplified.

The content of the conductive agent in the intermediate transfer belt 10 is, for example, preferably from 10 parts by weight to 30 parts by weight, and preferably from 12 parts by weight to 28 parts by weight with respect to 100 parts by weight of the total resin. More preferably, it is 15 parts by mass or more and 25 parts by mass or less.
When the content of the conductive agent in the intermediate transfer belt 10 is within the above range, the conductive points by the conductive agent in the intermediate transfer belt 10 become high density, and the discharge energy received on the surface of the intermediate transfer belt 10 is easily dispersed. Therefore, deterioration is suppressed.
Further, when the content of the conductive agent is in the above range, the intermediate transfer belt 10 can easily obtain the desired conductivity, and the high-density conductive points can be easily formed in the intermediate transfer belt 10.

  From the viewpoint of electrical resistance stability over time, the conductive agent preferably has a pH of 5 or less, desirably 4.5 or less, and more desirably 4.0 or less.

<Other ingredients>
The intermediate transfer belt 10 can include components (other components) other than the components described above.
For example, an antioxidant for preventing thermal deterioration of the intermediate transfer belt 10, a surfactant for improving fluidity, a heat-resistant anti-aging agent, and the like, particularly known in the intermediate transfer belt 10 of an image forming apparatus. These additives may be mentioned.

  The thickness of the intermediate transfer belt 10 is not particularly limited, but is preferably 60 μm or more and 150 μm or less.

  In the intermediate transfer belt 10 shown in FIG. 3, the intermediate transfer belt constituted by a single layer has been described, but the intermediate transfer belt 10 may be constituted by a laminate of two or more layers. In this embodiment, the outermost layer of the intermediate transfer belt has a plurality of recesses having a major axis in the belt axis direction, the size of the recesses (average major axis and average minor axis (preferably average depth)), and the presence of the recesses. It becomes the aspect by which the ratio is controlled by the said range.

[Method of manufacturing intermediate transfer belt]
The method for producing the intermediate transfer belt is not particularly limited. For example, a resin material is obtained by blending and kneading constituent materials such as a thermoplastic resin, a conductive agent, and other components, and then the resin material is extruded into a tubular shape. A method of producing an intermediate transfer belt through a step (extrusion step) and a step of taking out the extruded resin material (takeout step) is preferable. That is, the intermediate transfer belt according to the present embodiment is preferably a tubular extruded product.

  Hereinafter, as an example of a method for producing an intermediate transfer belt, a method for producing an intermediate transfer belt including polyetherimide and a siloxane-modified resin (preferably siloxane-modified PEI) as a thermoplastic resin and a conductive agent will be described.

  Specifically, a polyether imide, a siloxane-modified resin (preferably siloxane-modified PEI), and a conductive agent are blended and kneaded in predetermined amounts, respectively, to produce a resin material (for example, resin pellets). For the production of the resin material, it is preferable to use a biaxial melt extruder from the viewpoint of dispersing the conductive agent in the resin material with high uniformity. In addition, you may produce the resin material containing polyetherimide and the resin material containing siloxane modified resin, respectively.

Next, the obtained resin material is put into a melt extruder and extruded from a die into a tubular shape (extrusion process). The resin material extruded into a tubular shape is taken up by a take-up machine (take-off step).
In the extrusion process, since the siloxane-modified resin is contained in the resin material, when the resin material is extruded, the siloxane bond of the siloxane-modified resin is locally decomposed to form a recess having a relatively small diameter on the surface of the resin material. It is thought that it is done. In the subsequent take-up process, when the resin material is further taken up by the take-up machine, the concave portion having a relatively small diameter is extended in the axial direction (belt axial direction) of the resin material, and the major axis is increased in the belt axial direction. It is thought that the recessed part which has is formed.
Next, the resin material is cooled by bringing the outer peripheral surface of the cylindrical core into contact with the inner peripheral surface of the resin material to obtain a resin tubular body. In this way, a resin tubular body in which the size of the recesses and the existence ratio of the recesses are controlled in the above range is obtained.
Next, the obtained resin tubular body is cut into a target length to obtain an intermediate transfer belt.
The method of manufacturing the intermediate transfer belt is not limited to the above method. For example, after the intermediate transfer belt is obtained by a known method, a brush or the like (for example, a brass brush) is used on the surface of the belt. And you may form the recessed part with an existing ratio.

In the method of manufacturing the intermediate transfer belt, a siloxane-modified resin (preferably a siloxane-modified resin) with respect to polyetherimide in the resin material is used from the viewpoint of controlling the size of the recess having a major axis in the belt axis direction and the presence ratio of the recess to the above range. It is preferable to control the mass ratio of PEI) and the take-up speed of the resin material in the take-up step to the following ranges.
The mass ratio of siloxane-modified resin (preferably siloxane-modified PEI) to polyetherimide (siloxane-modified resin (preferably siloxane-modified PEI) / polyetherimide) is preferably 5 parts by mass or more and 50 parts by mass or less, and 8 parts by mass. It is preferably no less than 40 parts by mass and no greater than 10 parts by mass and no greater than 30 parts by mass.
When the mass ratio is increased, the size of the recesses having a major axis in the belt axis direction and the existence ratio of the recesses are easily controlled. Further, when the mass ratio is reduced, the size of the concave portion having a major axis in the belt axis direction and the existence ratio of the concave portion are easily controlled.

The take-up speed of the resin material is preferably 0.5 m / min or more and 2 m / min or less, more preferably 0.5 m / min or more and 1.5 m / min or less.
When the take-up speed is increased, the major axis of the concave part having a major axis in the belt axis direction is large, and the minor axis of the concave part is easily controlled to be small. Further, when the take-up speed is lowered, the major axis of the concave part having the major axis in the belt axis direction is small, and the minor axis of the concave part is easily controlled.
The temperature of the die in the extrusion process (preferably 300 ° C. or more and 330 ° C. or less) and the time (preferably 0.5 minutes or more and 2 minutes or less) until the resin material is cooled from the extrusion process through the take-off process. By adjusting, that is, by adjusting the total heat amount, the size of the concave portion having a major axis in the belt axis direction and the existence ratio of the concave portion can be easily controlled.

[Transfer unit]
The intermediate transfer belt 10 according to the present embodiment is suitably applied as an intermediate transfer belt 10 for an image forming apparatus, for example.
The transfer unit according to the present embodiment includes the intermediate transfer belt 10 according to the above-described embodiment and a plurality of rolls that span the intermediate transfer belt 10 in a tensioned state, and is detachable from the image forming apparatus. .

FIG. 4 is a schematic perspective view showing the transfer unit according to the present embodiment. As shown in FIG. 4, the transfer unit 130 according to this embodiment includes the intermediate transfer belt 10 according to the above-described embodiment. For example, the intermediate transfer belt 10 has a driving roll 131 and a driven roll disposed so as to face each other. 132 is stretched in a tensioned state (hereinafter, sometimes referred to as “stretching”).
Here, the transfer unit 130 according to the present embodiment includes a roll for primarily transferring the toner image on the surface of the photoreceptor (image holding member) onto the intermediate transfer belt 10 as a roll for stretching the intermediate transfer belt 10. A roll for secondary transfer of the toner image primarily transferred onto the intermediate transfer belt 10 to the recording medium is disposed.
The number of rolls on which the intermediate transfer belt 10 is stretched is not limited and may be arranged according to the usage mode. The transfer unit 130 having such a configuration is used by being incorporated in the apparatus, and rotates with the intermediate transfer belt 10 stretched along with the rotation of the drive roll 131 and the driven roll 132.

[Image forming apparatus]
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms a latent image on the surface of the charged image carrier, and an image carrier. The latent image on the surface of the toner image is developed with toner to form a toner image, the intermediate transfer belt according to the above embodiment, and the toner image formed on the surface of the image holding member is Primary transfer means for primary transfer, secondary transfer means for secondary transfer of the toner image primarily transferred onto the outer peripheral surface of the intermediate transfer belt to the recording medium, and fixing for fixing the toner image secondary transferred to the recording medium And a cleaning unit including a cleaning blade for removing toner remaining on the surface of the intermediate transfer belt (hereinafter also referred to as “intermediate transfer belt cleaning unit”).

  The image forming apparatus according to the present embodiment is, for example, a normal monocolor image forming apparatus in which only a single color toner is accommodated in a developing device, and a toner image held on an image holding member is sequentially subjected to primary transfer to an intermediate transfer member. Examples include a repetitive color image forming apparatus and a tandem type color image forming apparatus in which a plurality of image holding bodies each having a developing device for each color are arranged in series on an intermediate transfer body.

Hereinafter, an image forming apparatus according to the present embodiment will be described with reference to the drawings.
FIG. 5 is a schematic configuration diagram illustrating the image forming apparatus according to the embodiment.

As shown in FIG. 5, the image forming apparatus 100 according to the present embodiment is, for example, a so-called tande.

Charging device 102a to 102d (an example of a charging unit) and exposure devices 114a to 114d (latent) around four image carriers 101a to 101d made of an electrophotographic photosensitive member in order along the rotation direction. An example of image forming means), developing devices 103a to 103d (an example of developing means), primary transfer devices (primary transfer rolls) 105a to 105d (an example of primary transfer means), and image carrier cleaning devices 104a to 104d are arranged. Yes. Note that a static eliminator may be provided in order to remove residual potential remaining on the surfaces of the image carriers 101a to 101d after transfer.

The intermediate transfer belt 107 (an example of the intermediate transfer belt according to the present embodiment) is supported while applying tension by the support rolls 106a to 106d, the driving roll 111, and the opposing roll 108, and the transfer unit 107b (transfer according to the present embodiment). An example of a unit).
With the support rolls 106a to 106d, the driving roll 111, and the opposing roll 108, the intermediate transfer belt 107 is in contact with the surfaces of the image carriers 101a to 101d, and the image carriers 101a to 101d and the primary transfer rollers 105a to 105d. Can be moved in the direction of arrow A. A portion where the primary transfer rolls 105a to 105d come into contact with the image carriers 101a to 101d via the intermediate transfer belt 107 is a primary transfer portion, and a primary contact portion between the image carriers 101a to 101d and the primary transfer rollers 105a to 105d is a primary transfer portion. A transfer voltage is applied.

  As a secondary transfer device (an example of a secondary transfer unit), an opposing roll 108 and a secondary transfer roll 109 are disposed to face each other with an intermediate transfer belt 107 and a secondary transfer belt 116 interposed therebetween. The recording medium 115 such as paper moves in the direction of the arrow B while being in contact with the surface of the intermediate transfer belt 107 while being in contact with the surface of the intermediate transfer belt 107, and then passes through the fixing device 110. A portion where the secondary transfer roll 109 comes into contact with the opposing roll 108 via the intermediate transfer belt 107 and the secondary transfer belt 116 is a secondary transfer portion, and the secondary transfer roll 109 and the opposing roll 108 are in contact with the secondary transfer portion. A transfer voltage is applied. Further, intermediate transfer belt cleaning devices 112 and 113 (an example of an intermediate transfer belt cleaning unit) are disposed so as to come into contact with the intermediate transfer belt 107 after transfer.

  In the multi-color image forming apparatus 100 having this configuration, the image carrier 101a rotates in the direction of the arrow C, and the surface is charged by the charging device 102a, and then the first color static light is exposed by the exposure device 114a such as laser light. An electrostatic latent image is formed. The formed electrostatic latent image is developed (visualized) with toner by a developing device 103a containing toner corresponding to the color to form a toner image. The developing devices 103a to 103d contain toners (for example, yellow, magenta, cyan, and black) corresponding to the electrostatic latent images of the respective colors.

  The toner image formed on the image carrier 101a is electrostatically transferred (primary transfer) onto the intermediate transfer belt 107 by the primary transfer roll 105a when passing through the primary transfer portion. Thereafter, the first, second and third color toner images are primarily transferred onto the intermediate transfer belt 107 holding the first color toner image by the primary transfer rolls 105b to 105d so that the toner images of the second color, the third color, and the fourth color are sequentially superimposed. Finally, a multi-colored multiple toner image is obtained.

  The multiple toner images formed on the intermediate transfer belt 107 are electrostatically collectively transferred to the recording medium 115 when passing through the secondary transfer portion. The recording medium 115 onto which the toner image has been transferred is conveyed to the fixing device 110, fixed by heating and pressing, or heating or pressing, and then discharged outside the apparatus.

  Residual toner is removed from the image carriers 101a to 101d after the primary transfer by the image carrier cleaning devices 104a to 104d. On the other hand, residual toner is removed from the intermediate transfer belt 107 after the secondary transfer by the intermediate transfer belt cleaning devices 112 and 113 to prepare for the next image forming process.

-Image carrier-
As the image carriers 101a to 101d, known electrophotographic photoreceptors are widely applied. As the electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer made of an inorganic material, an organic photoreceptor having a photosensitive layer made of an organic material, or the like is used. In organic photoconductors, a function-separated type organic photoconductor that stacks a charge generation layer that generates charge upon exposure and a charge transport layer that transports charge, or a single layer that performs the function of generating charge and the function of transporting charge Type organic photoreceptors are preferably used. In addition, as the inorganic photoconductor, a photoconductive layer composed of amorphous silicon is preferably used.

  The shape of the image carrier is not particularly limited, and a known shape such as a cylindrical drum shape, a sheet shape, or a plate shape is employed.

-Charging device-
The charging devices 102a to 102d are not particularly limited, and are, for example, conductive (here, “conductive” in the charging device means, for example, a volume resistivity of less than 10 ⁷ Ω · cm) or semiconductive. (Here, “semiconductive” in the charging device means, for example, a volume resistivity of 10 ^{7 to} 10 ¹³ Ωcm.) A contact-type charger or corona using a roller, brush, film, rubber blade or the like Known chargers such as scorotron chargers and corotron chargers using discharge are widely applied. Among these, a contact charger is preferable.

  The charging devices 102a to 102d normally apply a direct current to the image carriers 101a to 101d, but an alternating current may be further superimposed and applied.

-Exposure device-
There are no particular limitations on the exposure apparatuses 114a to 114d, and for example, a light source such as a semiconductor laser light, a light emitting diode (LED) light, or a liquid crystal shutter light on the surface of the image carriers 101a to 101d, or these A well-known exposure apparatus such as an optical system apparatus capable of performing imagewise exposure from a light source via a polygon mirror is widely applied.

-Developer-
The developing devices 103a to 103d are selected according to the purpose. For example, a known developing device that develops a one-component developer or a two-component developer in contact or non-contact with a brush or roller or the like may be used.

-Primary transfer roll-
The primary transfer rolls 105a to 105d may be either a single layer or a multilayer. For example, in the case of a single layer structure, it is composed of a roll in which an appropriate amount of conductive particles such as carbon black is blended in foamed or non-foamed silicone rubber, urethane rubber, EPDM, or the like.

-Image carrier cleaning device-
The image carrier cleaning devices 104a to 104d are for removing residual toner adhering to the surfaces of the image carriers 101a to 101d after the primary transfer process. In addition to the cleaning blade, brush cleaning or roll cleaning is performed. Used. Among these, it is desirable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

-Secondary transfer roll-
The layer structure of the secondary transfer roll 109 is not particularly limited. For example, in the case of a three-layer structure, the secondary transfer roll 109 includes a core layer, an intermediate layer, and a coating layer covering the surface. The core layer is a foamed material such as silicone rubber, urethane rubber, or EPDM in which conductive particles are dispersed, and the intermediate layer is composed of these non-foamed materials. Examples of the material for the coating layer include tetrafluoroethylene-hexafluoropropylene copolymer or perfluoroalkoxy resin. The volume resistivity of the secondary transfer roll 109 is desirably 10 ⁷ Ωcm or less. Moreover, it is good also as a two-layer structure except an intermediate | middle layer.

-Opposed roll-
The counter roll 108 forms a counter electrode of the secondary transfer roll 109. The layer structure of the facing roll 108 may be either a single layer or a multilayer. For example, in the case of a single layer structure, it is composed of a roll in which an appropriate amount of conductive particles such as carbon black is blended in silicone rubber, urethane rubber, EPDM or the like. In the case of a two-layer structure, it is composed of a roll in which the outer peripheral surface of the elastic layer made of the rubber material is covered with a high resistance layer.

  A voltage of 1 kV or more and 6 kV or less is normally applied to the shafts of the opposing roll 108 and the secondary transfer roll 109. Instead of applying a voltage to the shaft of the opposing roll 108, a voltage may be applied to the electrically conductive electrode member brought into contact with the opposing roll 108 and the secondary transfer roll 109. Examples of the electrode member include a metal roll, a conductive rubber roll, a conductive brush, a metal plate, or a conductive resin plate.

-Fixing device-
As the fixing device 110, for example, a known fixing device such as a heat roller fixing device, a pressure roller fixing device, or a flash fixing device is widely applied.

-Intermediate transfer belt cleaning device-
As the intermediate transfer belt cleaning devices 112 and 113, brush cleaning or roll cleaning is used in addition to the cleaning blade. Among these, it is desirable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  Although the intermediate transfer belt according to the present embodiment and the transfer unit and the image forming apparatus using the intermediate transfer belt according to the present embodiment have been described above, the present invention is not limited to the above aspect.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Example 1]
<Preparation of mixed resin pellets>
Carbon as a conductive agent with respect to a total of 100 parts by mass of 90 parts by mass of polyetherimide (Ultem 1010, manufactured by Sabic) as a thermoplastic resin and 10 parts by mass of siloxane-modified PEI (Siltem 1500, manufactured by Sabic) and PEI and siloxane-modified PEI 20 parts by mass of black (Printex alpha, manufactured by Orion Engineered Carbon Co., average primary particle size: 20 nm), and a biaxial extrusion melt kneader (biaxial melt kneader extruder L / D60 (manufactured by Parker Corporation) ) Was melt kneaded at a resin heating temperature of 340 ° C./screw rotation speed of 200 rpm. The kneaded melt was put in a water bath, cooled and solidified, and then cut to obtain mixed resin pellets in which carbon black was blended with PEI resin and siloxane-modified PEI resin.

<Preparation of intermediate transfer belt>
Mixed resin pellets obtained by melt-kneading (hereinafter also referred to as “resin material”) are put into a uniaxial melt extruder (L / D24, melt-extrusion apparatus, manufactured by Mitsuba Seisakusho), and the resin heating temperature is 320 ° C. / The melted resin material was melted at a screw speed of 20 rpm, and the molten resin material was extruded into a tubular shape from the gap between the mold die and the nipple set at 300 ° C. (extrusion process). In order to fix the shape and the diameter of the tube while taking up the resin material extruded into a tube at a take-up speed of 1.0 m / min so that the thickness in the circumferential direction becomes an average of 100 μm (take-off step) The resin material was cooled by bringing the outer peripheral surface of the cylindrical core into contact with the inner peripheral surface of the material. This obtained the resin tubular body. The obtained resin tubular body was cut to produce an intermediate transfer belt (hereinafter also referred to as “belt”) 1.
In the production of the belt 1, a plurality of concave portions having a major axis in the belt axis direction are formed by decomposition of the siloxane-modified PEI. The same applies to the belt 2, the belt 3, and the belts 2C to 4C described later.

[Example 2]
In Example 1, a belt 2 was obtained in the same procedure as in Example 1 except that the take-up speed was changed to 1.2 m / min.

[Example 3]
In Example 1, belt 3 was obtained in the same procedure as in Example 1 except that the take-up speed was changed to 0.7 m / min.

[Example 4]
In Example 1, a belt was obtained in the same procedure as in Example 1 except that the temperature setting of the die and the nipple was changed to 285 ° C. Thereafter, a belt 4 was obtained by forming a plurality of recesses having a major axis in the belt axial direction on the surface of the belt using a brass brush.

[Comparative Example 1]
After obtaining a belt in the same manner as in Example 4, a plurality of recesses having a long diameter in the direction orthogonal to the belt axial direction (belt circumferential direction) are formed on the surface of the belt using a brass brush. Got.

[Comparative Example 2]
Same as Example 1 except that the resin heating temperature was 320 ° C./screw rotation speed 12 rpm in the extrusion process of Example 1 and that the take-up speed was changed to 0.4 m / min in the take-up process. A belt 2C was obtained by the procedure described above.

[Comparative Example 3]
In Example 1, belt 3C was obtained in the same procedure as in Example 1 except that the take-up speed was changed to 2.5 m / min.

[Comparative Example 4]
A belt 4C was obtained in the same procedure as in Example 1 except that PEI was changed to 98 parts by mass and siloxane-modified PEI was changed to 2 parts by mass in Example 1.

[Evaluation]
<Average major axis of recess, average minor axis of recess, ratio of presence of recess, average depth of recess, and angle with respect to belt axis direction>
The belt surface obtained in each example and each comparative example was observed by the method described above, and the average major axis of the recesses, the average minor axis of the recesses, the presence ratio of the recesses, the average depth of the recesses, and the belt axial direction The angle (angle on the acute angle side) was measured. The results are shown in Table 1.
“Angle with respect to the belt axis direction” in Table 1 indicates a range of the measured angles of all the concave portions (range of the lower limit value and the upper limit value).

<Cleaning maintenance>
The belt (intermediate transfer belt) obtained in each example was incorporated into DocuPrint CP200W manufactured by Fuji Xerox Co., Ltd., and C2 paper A4 paper manufactured by Fuji Xerox Co., Ltd. was used under a low temperature and low humidity environment (10 ° C, 15% RH environment). And 10,000 total patterns with patches.
Cleaning maintainability refers to whether or not streaks due to poor cleaning occur on the output paper, and whether or not external additives adhere to the recesses on the belt surface after output (external additive adhesion state). ) From both results. In addition, the adhesion state of the external additive was determined by SEM observation. Judgment criteria are as follows.

-Judgment criteria (streaks due to poor cleaning)-
G1 (◯): no streaks were generated (the number of generated sheets was 0).
G2 (Δ): Streaks occurred and the number of generated sheets was less than 5.
G3 (x): Streaks occurred, and the number of generated sheets was 5 or more and 50 or less.

-Judgment criteria (attachment of external additives)-
G1 (◯): No external additive adhered to the concave portion of the belt surface.
G2 (Δ): An external additive is adhered in the concave portion of the belt surface.
G3 (x): An external additive has embedded toner or the like as a binder resin in the concave portion of the belt surface.

From the above results, compared to the comparative example, this example suppresses the generation of streaks due to poor cleaning, and also suppresses the adhesion of external additives into the recesses on the belt surface after output, and maintains the cleaning. It can be seen that the properties are good.
That is, it can be seen that in this example, deterioration of the cleaning property after repeated image formation is suppressed even in a low temperature and low humidity environment (10 ° C., 15% RH environment) as compared with the comparative example.
Further, in Examples 1, 2, and 4 in which the average depth of the recesses is 1 μm or more and 5 μm or less, compared to Example 3 in which the average depth of the recesses exceeds 5 μm, generation of streaks due to poor cleaning is suppressed, It can be seen that adhesion of the external additive into the concave portion of the belt surface after output is also suppressed.

10 Intermediate transfer belt 100 Image forming apparatus 101a, 101b, 101c, 101d Image carrier 102a, 102b, 102c, 102d Charging device (an example of charging unit)
103a, 103b, 103c, 103d Developing device (an example of developing means)
104a, 104b, 104c, 104d Image carrier cleaning devices 105a, 105b, 105c, 105d Primary transfer roll (an example of primary transfer means)
106a, 106b, 106c, 106d Support roll 107 Intermediate transfer belt 107b Transfer unit 108 Opposing roll 109 Secondary transfer roll (an example of secondary transfer means)
110 Fixing device 111 Drive roll 112, 113 Intermediate transfer belt cleaning device (an example of intermediate transfer belt cleaning means)
114a, 114b, 114c, 114d Exposure device (an example of latent image forming means)
115 Recording Medium 131 Drive Roll 132 Followed Roll

Claims (7)

A plurality of recesses having a major axis in the belt axis direction, wherein the average major axis of the plurality of recesses is 20 μm or more and 1000 μm or less, and the average minor axis of the plurality of recesses is 3 μm or more and 800 μm or less; Is an intermediate transfer belt of 1 piece / mm ² or more.   The intermediate transfer belt according to claim 1, wherein an average depth of the plurality of recesses is 1 μm or more and 5 μm or less.   The intermediate transfer belt according to claim 1, comprising a thermoplastic resin.   The intermediate transfer belt according to claim 3, wherein the thermoplastic resin is a polyetherimide and a siloxane-modified polyetherimide.   The intermediate transfer belt according to claim 3 or 4, wherein the intermediate transfer belt is a tubular extruded product. The intermediate transfer belt according to any one of claims 1 to 5,
A plurality of rolls that hang the intermediate transfer belt in a tensioned state;
And a transfer unit that is detachable from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing a latent image on the surface of the image carrier with toner to form a toner image;
The intermediate transfer belt according to any one of claims 1 to 5,
Primary transfer means for primarily transferring the toner image formed on the surface of the image carrier onto the outer peripheral surface of the intermediate transfer belt;
Secondary transfer means for secondary transfer of the toner image primarily transferred to the outer peripheral surface of the intermediate transfer belt to a recording medium;
Fixing means for fixing the toner image secondarily transferred to the recording medium;
Cleaning means comprising a cleaning blade for removing toner remaining on the surface of the intermediate transfer belt;
An image forming apparatus.