JP2002265642A - Seamless semiconductive belt - Google Patents

Abstract

[PROBLEMS] To provide a seamless semiconductive belt which can be suitably used as a transfer belt 6 or the like in an electrophotographic image forming apparatus capable of stably forming a high quality image. SOLUTION: A seamless semiconductive belt is made of a fluorine-based thermoplastic resin composition containing an ion-conductive additive or an ion-conductive polymer and a coloring agent, and has a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm. The configuration is as follows. This seamless semiconductive belt has excellent resistance uniformity and has sufficient light-shielding properties. Therefore, when this seamless semiconductive belt is used as the transfer belt 6, the toner images formed on the photosensitive drums of the image forming apparatuses 201 to 204 can be stably and satisfactorily transferred onto the transfer paper 205. Automatic correction of registration and control of toner density can be satisfactorily performed by a method of irradiating light to the substrate and detecting the reflected light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seamless belt which is used as a material for a seamless belt used as a component of an intermediate transfer device, a transfer transfer device and the like in an image forming apparatus such as an electrophotographic copying machine and a laser beam printer. The present invention relates to a semiconductive belt.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus which forms an electrostatic latent image by irradiating light onto a photoreceptor and forms an image using the electrostatic latent image, a toner image formed on the electrostatic latent image is formed on the photoreceptor. Various functional belts, such as a transfer belt and an intermediate transfer belt, are used for transferring to a recording paper by electrostatic force. FIG. 1 shows a schematic configuration diagram of a general example of an electrophotographic image forming apparatus using a transfer belt.

This electrophotographic image forming apparatus has a cylindrical photosensitive drum 101 made of a photosensitive member. The photosensitive drum 101 is rotatably supported, and is driven to rotate clockwise in FIG. 1 by a driving device (not shown). The transfer belt 107 includes three stretching rollers 108, 1
09, 111 and the drive roller 110, and is supported so as to be able to circulate on a circulation path passing near the lower end of the photosensitive drum 101. The drive roller 110 is driven to rotate by a drive device (not shown). 1 circulates counterclockwise in FIG.

Around the photosensitive drum 101, a charging charger 102, an optical writing device 103, and a developing device 105 are provided upstream of a lower end position passing near the transfer belt 107 when viewed in the rotation direction of the photosensitive drum 101. They are arranged in order toward the downstream side. The charged charger is a photosensitive drum 10
1 is uniformly charged. The optical writing device 103 irradiates the surface of the photoconductor with laser light in a desired pattern. The optical writing device 103 may be configured to emit reflected light. The developing device 105 contains the toner 106,
The charged toner 106 is supplied to the surface of the photosensitive drum 101.

The above-mentioned 3 supporting the transfer belt 103 by stretching it.
When viewed in the direction of movement of the transfer belt 107, one of the stretching rollers 108, 109, and 111 has a paper roller that charges the transfer belt 107 on the upstream of a position that passes near the lower end of the photosensitive drum 101. The adsorber 113 is connected. Further, a power supply for applying a voltage for discharging the charged transfer belt 101 is connected to the stretching roller 111 downstream of a position passing near the lower end of the photosensitive drum 101. A transfer charger 114 for applying a predetermined voltage for transferring the toner 106 is disposed below a position of the transfer belt 107 passing near the lower end of the photosensitive drum 101, and a transfer area is formed above the transfer charger 114. ing.

A paper feeding means (not shown) for supplying the transfer paper (recording paper) 112 onto the transfer belt 112 at a predetermined timing is provided on the circulation orbit of the transfer belt 112 on the upstream side of the transfer area. . Further, a fixing device 115 for fixing the transferred toner on the transfer paper 112 is provided on the downstream side of the transfer area in the circulation path of the transfer belt 112.

[0007] Image formation by this electrophotographic image forming apparatus is performed as follows. First, the photosensitive drum 101
The transfer belt 107 is driven at a constant speed Vf.

At this time, on the photosensitive drum 101 side, first, the surface of the photosensitive drum 101 is uniformly charged by the charging charger 102. Next, light is irradiated on the charged surface by the optical writing device 103 in a predetermined pattern corresponding to an image to be formed, and an electrostatic latent image is formed. Next, on the surface on which the electrostatic latent image is formed, the developing device 105
The charged toner is supplied, and the electrostatic latent image is visualized as a toner image.

On the other hand, on the transfer belt 107 side, the transfer belt 107 is first charged by the paper charging and adsorbing unit 113. Then, at a predetermined timing, the transfer paper 112 is supplied onto the charged transfer belt 107, and the supplied transfer paper 112 is attracted onto the transfer belt 107 by electrostatic force, and at the same constant speed Vf as the transfer belt 107. Conveyed.

When the transfer paper 112 reaches the transfer area near the lower end of the photosensitive drum 101, the toner 106 visualized on the photosensitive drum 101 is transferred onto the transfer paper 112 by the electrostatic force generated by the transfer charger 114. Transcribed.
Then, the transfer paper 112 is further conveyed to the fixing device 11.
5, where the transferred toner 106 is fixed on the transfer paper 112.

As described above, in the image forming apparatus described with reference to FIG. 1, the case where the number of the photosensitive drums 101 is one is shown. However, in a full-color image forming apparatus, for example, a plurality of photosensitive drums are used. FIG. 2 shows a schematic configuration diagram of such a general example of a full-color image forming apparatus.

In this full-color image forming apparatus, an image forming apparatus having a photosensitive drum, a charging charger, an optical writing device, a developing device, and a transfer charging device having the same configuration as that provided in the image forming device shown in FIG. 201 to 204 are magenta (M), cyan (C), yellow (Y), black (B
k) are independently arranged for image formation of each color. Then, the transfer belt 206 is connected to these image forming apparatuses 201.
２０４204 so as to circulate on a circulating trajectory passing through each transfer area where transfer is performed.

In this full-color image forming apparatus, when the transfer paper 205 is conveyed while being held on the transfer belt 206, first, a magenta (M) toner image is transferred by the magenta (M) image forming apparatus 201. Formed on paper 205. Next, when the transfer paper 205 is further transported,
The cyan (C) image forming apparatus 202 causes the cyan (C)
Is formed on the transfer paper 205. Next, a yellow (Y) toner image is formed on the transfer paper 205 by the yellow (Y) image forming device 203, and then a black (Bk) toner image is formed by the black (Bk) image forming device 204. It is formed on the transfer paper 205.

After the images of magenta (M), cyan (C), yellow (Y), and black (Bk) are accurately developed and transferred in this way, the fixing device 207 transfers the toner image to the transfer paper. The image is fixed on the image 205 and the image formation is completed.

In the full-color image forming apparatus as shown in FIG. 2, the transfer sheet 112 is likely to be displaced in the feed direction. Therefore, as a method of avoiding this, as shown in FIG. 3, a registration mark 302 for registration correction is transferred onto the transfer belt 206, and light having a wavelength of, for example, 400 to 1000 nm is irradiated from a light source 303 and reflected. A method of detecting the reflected light with the photo sensor 304 is used. That is, by doing so, the photosensor 3
Since the transfer signal of the transfer paper 205 can be detected from the detection signal of 04, the operation timing of the image forming apparatuses 201 to 204 is automatically corrected in accordance with this detection timing, so that the image formation position of each color can be determined. It can be adjusted with high accuracy.

The photo sensor 304 may be used not only to detect the position of the transfer paper 205 but also to detect the color of each color image. By doing so, the toner is changed according to the output of the photo sensor 304.
The density can be controlled, and a high-quality image can be formed.

Here, in an image forming apparatus for forming a high-precision full-color image, the transfer belt is controlled in resistance by adding an electronic conductive filler, for example, a thermoplastic resin such as a nylon resin or a fluorine resin. To
A seamless resistance control (semi-conductive) belt manufactured from a material obtained by mixing an appropriate amount of carbon black has been used. In the image forming apparatus, there is also known a configuration in which a toner image formed on a photoreceptor is primarily transferred to an intermediate transfer belt, and a toner image transferred on the intermediate transfer belt is secondarily transferred onto recording paper. A similar seamless resistance control (semiconductive) belt is used as such an intermediate transfer belt.

[0018]

However, in recent years, higher image quality has been demanded for the above-described image forming apparatus, and the transfer belt having the above-described configuration meets this demand. It's getting harder.

That is, in the transfer belt having the above-described configuration, since the filler-based additive is used, the filler-based additive is not always sufficiently dispersed in the thermoplastic resin, and the uniformity of the transfer belt resistance is not sufficient. . For this reason, the transfer of the toner image is unstable, and uneven transfer may be observed.

Also, by controlling the conductivity of the transfer belt by adding an ionic conductive additive or an ionic conductive polymer, it is possible to perform relatively good conductivity control. It becomes transparent or translucent. For this reason, it is difficult to irradiate the transfer belt with light as described above, detect the reflected light with a photosensor, and correct the registration and control the toner density based on the detection result.

That is, a part of the light emitted from the light source onto the transfer belt passes through the transfer belt, and the amount of the transmission affects the detection result. Further, a part of the transmitted light is reflected on the surface of the transfer belt opposite to the light incident surface, and the reflected light also affects the detection result.

The transfer belt is driven by being suspended by a plurality of rollers as described above. Therefore, this roller is in contact with the transfer belt, and various other members such as a transfer paper, a cleaning blade, The transfer paper transport roller contacts. For this reason, the transfer belt is finely scratched or stained, and this causes a temporal change in the amount of transmitted light, the amount and direction of reflected light, and the like, and the transfer position and the hue are accurately detected by the photo sensor. It becomes difficult. In particular, the back surface of the transfer belt is easily scratched or stained, and the change in the amount of light reflected from the back surface of the transfer belt shows a large change in long-term use.

As described above, when the transfer belt having the conventional configuration is used, registration correction and toner density control cannot be performed with high accuracy, and it is impossible to cope with high image quality.

The present invention has been made based on such a background, and an object of the present invention is to provide an image forming apparatus which can stably form high-quality images, has excellent durability, and can be manufactured at low cost. An object of the present invention is to provide a seamless semiconductive belt suitable as a material for a seamless belt used as a transfer belt or an intermediate transfer belt.

[0025]

In order to achieve the above-mentioned object, a seamless semiconductive belt according to the present invention comprises a fluorine-containing thermoplastic resin containing an ionic conductive additive or an ionic conductive polymer and containing a coloring agent. Consisting of a resin composition,
It is characterized in that the volume resistance value is 10 ⁸ to 10 ¹⁴ Ωcm.

At this time, as the fluorine-based thermoplastic resin,
In particular, an ethylene tetrafluoride ethylene copolymer and / or an ethylene trifluoride ethylene chloride copolymer can be suitably used. In another embodiment, particularly, polyvinylidene fluoride can be suitably used as the fluorine-based thermoplastic resin.

As a coloring additive, carbon black can be particularly preferably used. Further, the addition amount A of the carbon black used as the coloring additive is 0.2 <A <3 with respect to 100 parts by weight of the fluorine-based thermoplastic resin.
It is particularly preferred that the amount is by weight.

According to this configuration, the resistance of the seamless semiconductive belt mainly composed of the fluoroplastic resin can be uniformly and precisely controlled by using the ionic conductive additive or the ionic conductive polymer as the conductive agent. can do. In addition, by adding a colorant, the light transmittance of the seamless semiconductive belt is appropriately regulated, and the automatic correction of the registration and the toner density control using the photo sensor as described above can be performed satisfactorily. it can.

[0029]

Next, an embodiment of the seamless semiconductive belt of the present invention will be described. First, each component will be described.

The ionic conductive additives used in the seamless semiconductive belt of the present invention include polyvalent metal salts and quaternary ammonium salts.

The quaternary ammonium salt includes, as a cation moiety, a tetraethylammonium ion, a tetrapropylammonium ion, a tetraisopropylammonium ion, a tetrabutylammonium ion, a tetrapentylammonium ion, a tetrahexylammonium ion, and the like. Examples thereof include a halogen ion, a fluoroalkyl sulfate ion having 1 to 10 carbon atoms in a fluoroalkyl group, a fluoroalkyl sulfite ion, and a fluoroalkyl borate ion.

In particular, in the present invention, the ionic conductive additive is
Perfluoroalkyl quaternary ammonium salts are preferred because they are added to the fluorine-based thermoplastic resin.

Examples of the ionic conductive polymer used in the seamless semiconductive belt of the present invention include, for example, various copolymers such as a styrene copolymer with a (meth) acrylate having a quaternary ammonium base bonded to a carboxyl group. And a polymer that binds a quaternary ammonium base, such as a copolymer of maleimide and methacrylate that binds to a quaternary ammonium base. Further, a polymer that binds an alkali metal salt of sulfonic acid found in sodium polysulfonate and the like can be used. In addition, a polymer that binds at least a hydrophilic unit of an alkyl oxide in a molecular chain may be used. Further, for example, polyethylene oxide, a polyethylene glycol-polyamide copolymer, a polyethylene oxide-epichlorohydrin copolymer, polyetheramide imide, a block type polymer having a polyether as a main segment, and the like can be mentioned. It is necessary to check the compatibility of these polymers with the fluorine-based thermoplastic resin serving as the matrix, the relationship with the heat resistance, and the like, and select an appropriate polymer according to the fluorine-based thermoplastic resin used. In many cases, a relatively high molecular weight polymer that binds the hydrophilic units of the alkyl oxide can be selected as the preferred ionic conductive polymer.

The fluorine-based thermoplastic resin used for the seamless semiconductive belt of the present invention includes ethylene-tetrafluoroethylene copolymer and / or ethylene-3-fluoroethylene chloride copolymer, polyvinylidene fluoride, Although there is a fluorinated ethylene-6-fluorinated propylene copolymer, an ethylene-tetrafluoroethylene copolymer and / or an ethylene-3-fluorochlorinated ethylene copolymer and polyvinylidene fluoride having particularly high mechanical strength are preferred.

As the coloring additive used in the seamless semiconductive belt of the present invention, any coloring agent may be used as long as it is dispersed in a fluorine-based thermoplastic resin. A pigment can also be used.

Examples of the inorganic pigments include titanium oxide, zinc oxide, cadmium yellow, titanium chrome yellow, titanium yellow, cadmium orange, heat-resistant vermillion,
Cadnium red, kinkridone red, chromium oxide green, cobalt nickel green, cobalt blue,
You can choose iron chrome brown, red iron, or cobalt violet.

As organic pigments, polyazo yellow,
Polyazo red, berylen red, DPP red, cyanine green, cyanine blue, quinacridone violet and carbon black can be selected.

In particular, when the colorant has conductivity, it is necessary to pay attention to the selection of the type and the amount of the colorant.

It is particularly preferable to use carbon black as a coloring agent because it is added as an image forming member, is well compatible with a fluorine-based thermoplastic resin, and can be colored black. .

When carbon black is used as the coloring additive, the compounding amount A of carbon black is preferably 0.2 <A <3 parts by weight based on 100 parts by weight of the fluorine-based thermoplastic resin. . If the amount of carbon black exceeds this range, the seamless semiconductive belt after molding has electronic conductivity due to the carbon black. As a result, the resistance distribution of the seamless semiconductive belt depends on the dispersion state of carbon black, and the uniformity of resistance tends to be impaired. Further, when the addition amount of the carbon black is less than the above range, when the molded fluorocarbon thermoplastic resin is used as a transfer belt, the transfer belt cannot sufficiently block light, and It is difficult to uniformly disperse the carbon black in each part of the belt. For this reason, in the detection for performing the automatic correction of the registration and the toner density control as described above, the light from the light source cannot be completely blocked, and the amount of light blocking in each part of the belt is different. Could not stably receive the reflected light.

Next, in the present invention, each part of the belt
Volume electric resistance value of 10⁸-10¹⁴Ωcm range
The necessity is described. First, the seamless semiconductor of the present invention
The conductive belt is, for example, an intermediate transfer belt in a copying machine.
The basics of the image forming apparatus
The principle will be explained. Solid toner generally called toner
Ink is deposited on the photoreceptor in a desired pattern.
-The image is intermediately transferred from the photoconductor by electrostatic action.
The image is transferred to the belt (primary transfer). Thus transcribed
The toner is further transferred from the intermediate transfer belt to the transfer paper (secondary
Transfer) to form a desired image. This intermediate transfer base
Volume electric resistance value at each part ⁸Less than Ωcm
When the transfer voltage is applied, the intermediate transfer bell
Electricity flows on the belt
It is difficult to produce on top, suitable primary transfer, secondary transfer
The photo will not be taken. Also, each intermediate transfer belt
Volume electric resistance in the part is 10¹⁴If it exceeds Ωcm,
The belt insulation becomes too strong, causing toner to be transferred.
Even if an electric field is generated to capture an image, a desired amount of current can be obtained
Can not be performed, also suitable primary transfer and secondary transfer are performed
Not. Therefore, in the present invention, seamless
Electric resistance of each part of the conductive belt is 10⁸
-10¹⁴Ωcm range.

The use of the present invention is not particularly limited.
It was useful as various functional belts used in image forming apparatuses and the like, and was suitably used as a transfer belt or an intermediate transfer belt as an example.

As an example, FIG. 4 shows a schematic configuration diagram of a full-color image forming apparatus using a seamless conductive belt according to the present invention as a transfer belt 6. This full-color image forming apparatus has the same configuration as the general full-color image forming apparatus shown in FIG. 2 except that a seamless conductive belt having the configuration of the present invention is used as the transfer belt 6. Is omitted.

In this full-color image forming apparatus, since the transfer belt 6 has excellent resistance uniformity, the transfer of the toner image onto the transfer paper 205 can be performed stably and favorably. Further, since the transfer belt 6 has a sufficient light shielding property, by irradiating the transfer belt 6 with light and detecting the reflected light, the position of the transfer paper 205 and each image forming apparatus 20 are determined.
The color of the formed image in Nos. 1 to 204 can be detected well.
Therefore, high-quality image formation can be performed by satisfactorily performing automatic registration and toner density control.

The seamless conductive belt of the present invention may be blended with a fluorine-containing thermoplastic resin and an ionic conductive additive / an ionic conductive polymer and a coloring agent, if necessary, with appropriate components. Good. For example, a lubricant such as wax, silicone oil, or a low-molecular-weight fluorine-based thermoplastic resin (oligomer of the resin used) can be appropriately compounded. The lubricant is usually added in an amount of, for example, 1.5 parts by weight or less, preferably about 0.5 to 1.5 parts by weight, based on the total weight of the raw materials used, but the lubricant may not be used.

It is often preferable to mix an inorganic filler or an organic filler in the seamless semiconductive belt according to the present invention in order to improve creep characteristics and durability, but there is no particular limitation. At this time, as the inorganic filler,
Although there is no particular limitation, for example, talc, whisker titanate, mica, or the like can be used, and it is preferable to use one having a particle size of about 1 to 2 μm in consideration of the surface accuracy of the belt. The organic filler is not particularly limited,
Examples thereof include a liquid crystal polymer and an aramid fiber. The amount of the filler added is not particularly limited and may be any suitable amount. Generally, 20 parts by weight or less, preferably 5 to 20 parts by weight is often mixed, but it is not always necessary to add the filler. It is not necessary to add it.

The seamless semiconductive belt of the present invention comprises:
Although it can be manufactured as follows, the following merely shows an example of the manufacturing method, and the present invention is not particularly limited by this manufacturing method.

Here, as the fluorine-based thermoplastic resin,
The case where a polyvinylidene fluoride resin is used will be briefly described.

First, the respective raw materials described above are blended. The method of blending is not particularly limited, but for example,
The mixing blend method can be mentioned. The mixer used for the mixing blend is not particularly limited. However, considering that the ionic conductive additive / ionic conductive polymer and the colorant are uniformly dispersed in the fluorine-based thermoplastic resin as a base. For example, it is preferable to use an extruder having a twin screw. Further, when it is desired to further improve the dispersibility, the polyvinylidene fluoride resin powder and the powder of the ion conductive additive / ion conductive polymer and the colorant are physically and mechanically mixed, for example, hybridization. The mixing can be performed by the method described above, but this is not particularly limited.

The raw material thus mixed and blended is usually extruded into pellets. The raw material that has been blended and formed, for example, in the form of pellets as described above may foam at the time of film formation if it is not completely dried, so if necessary, the moisture content should be about 0.05 part by weight or less. It may be dehumidified and dried as needed. In addition, when mixing and pelletizing are performed in a gas atmosphere having a low reactivity such as nitrogen gas or carbon dioxide gas or an inert gas such as helium gas, fluctuation in molecular weight of the polyvinylidene fluoride resin can be suppressed. Is often preferred. It should be noted that the volume electric resistance value of the obtained pellets may fluctuate depending on the mixing blend. It is often more preferable to dry the thus obtained composition in a gas having low reactivity or an inert gas as described above. Mixing and pelletization are preferably performed at a low temperature. Addition of a lubricant can often prevent a decrease in molecular weight, and it is preferable to add a lubricant as needed, but it is not particularly necessary to add a lubricant.

Next, the blended and, if necessary, pelletized raw materials are formed into a seamless film. The seamless film here includes a sheet-shaped thick film (up to 1 mm). The film forming method is not particularly limited, but an extrusion film forming method from an annular die is preferable.
When forming a film by extrusion from an annular die, in order to obtain a material having a high dimensional accuracy such as a constant diameter and a constant thickness, it is desirable to control the size by a sizing portion such as an inside or outside mandrel. The cooling temperature of the sizing portion is particularly important, and it is desirable to carefully select the temperature of the cooling water, the material of the sizing portion, and the like according to the type of polyvinylidene fluoride resin, the electric resistance value, the film thickness, and the like. Appropriate selection is often preferred, as it improves the film formability of the tube and at the same time reduces the amount of decomposed monomer adhering to the sizing surface. In the production method according to the present invention, for example, it is preferable to perform cooling by circulating cooling water in a cylindrical sizing portion,
The temperature of the circulating cooling water is not particularly limited, but is usually 0 to 90 ° C, preferably 20 to 60 ° C. The extruded seamless film is preferably taken off without any fold. As a preferred method of taking out the sheet, for example, a caterpillar method of using a caterpillar conveyor pair having a soft holding claw portion and lightly pushing the seamless film to such an extent that no fold remains so as to be taken out can be exemplified.
It is desirable to increase the area of contact with the film as described above so that the film is not creased.

The volume electric resistance of the obtained seamless film is determined mainly by the amount of the ionic conductive additive / ion conductive polymer to be blended. The volume electric resistance of each part of the seamless film depends on the film forming conditions. Also vary considerably. Therefore, in order to control the volume electric resistance value to a predetermined value and to keep the fluctuation range of the volume electric resistance value of each part of the film within a certain value, sufficient attention must be paid to the film forming conditions. For example, when performing extrusion film formation,
Fluidity and viscosity of the blended raw materials, pressure applied in the extruder, and other factors may cause fluctuations in the volume electrical resistance of each part of the film. It is desirable to do well. At this time, in order to control the pressure in the extruder, a polyvinylidene fluoride resin may be charged into the extruder via a gear pump. Such a gear pump may be of any type as long as it can guide the molten resin to the die quantitatively, and a commercially available gear pump can be used.

When higher dimensional accuracy is required, for example, after extrusion film formation, processing suitable for improving dimensional accuracy, such as regulation with a fixed size guide or stretching, may be performed. Good. When stretching is performed, the distribution of the contact state of the conductive carbon fluctuates depending on the degree of the stretching ratio in the vertical and horizontal directions (the axial direction and the circumferential direction of the seamless film). Since the resistance value fluctuates,
It is desirable to set conditions accurately in advance. The stretching ratio may be, for example, 3 to 5% in each of the vertical and horizontal directions. The stretching temperature is 60 to 180 ° C, preferably 120 to 180 ° C.
The stretching temperature and the stretching temperature are not limited to the above ranges.

By using the above-mentioned additives under the conditions described above, it is possible to control the dispersion of the volume electric resistance so as to be small.
In addition, it becomes possible to manufacture a seamless film excellent in dimensional accuracy such as diameter and thickness. Of course, if it is not necessary to make the electrical resistance value, dimensional accuracy, etc. too high, it is free to make any tube-like film,
When used as a functional belt in an image forming apparatus for electrostatic control, conveyance, and the like, it is often desirable that the above-described characteristics be excellent.

According to the present invention, the seamless film thus obtained is sequentially cut into a predetermined length at a predetermined length in a direction (circumferential direction) perpendicular to the axial direction (machine direction, extrusion direction). Can be obtained. In the exemplified manufacturing method by extrusion film formation, the belt width can be arbitrarily adjusted only by changing the cutting length, and a belt having a desired width can be easily manufactured.

[0056]

The present invention will be described below with reference to more specific examples.

Example 1 100 parts by weight of ethylene-tetrafluoroethylene copolymer, 1 part by weight of (C ₃ H ₇ ) ₄ NB (C ₂ F ₅ ) ₄ and 1 part by weight of Ketjen black were mixed with nitrogen. Blending was performed using a hybridization system in a gas atmosphere. The obtained blend was subsequently charged into an extruder having a twin screw in nitrogen gas, and pelletized raw materials were granulated. This pellet-like raw material is φ65 mm with L / D = 24.
It was introduced into an extruder, led to an annular die via a gear pump, and melt-extruded into a tube. Next, the melt-extruded product was taken out while cooling from the inside with a sizing sleeve having an outer diameter of 60 mm, and a film having a thickness of 160 μm was formed. At this time, the temperature in the annular die was controlled at 300 ° C. Further, a 20-mesh basket-shaped stainless steel filter was mounted between the screw tip of the extruder and the die. The thus-obtained seamless film was stretched at a temperature of 140 ° C. in the machine direction and the circumferential direction by 3% each. The stretched film is then brought to 350
By cutting at intervals of mm, a seamless semiconductive belt of this width was obtained.

Example 2 100 parts by weight of a polyvinylidene fluoride resin, 0.8 parts by weight of (C ₃ H ₇ ) ₄ NSO ₄ (C ₆ F ₁₃ ) and 1.5 parts by weight of acetylene black were mixed with nitrogen. The blend was blended using a hybridization system in a gas atmosphere, and the obtained blend was subsequently charged into an extruder having a twin screw in a nitrogen gas atmosphere to prepare a pellet-shaped raw material. This pellet-shaped raw material is φ6 with L / D = 19.
It was introduced into a 5 mm extruder, guided to a spiral annular die through a gear pump, and melt-extruded into a tube directly below the slit opening. Then, the melt-extruded product was used for the inner diameter 5
Cooling while regulating with a sizing sleeve in a 20 mm immersion vacuum water cooling tank, nip only the middle part using 12 nip rolls with a width of 50 mm, take off so as not to make folds, seamless film with a thickness of 160 μm and a diameter of 500 mm The film was formed in the shape of Next, the seamless film was stretched at a temperature of 130 ° C. in the machine direction and the circumferential direction by 3% each. At this time, the four-piece heater was arranged stepwise in the circumferential direction of the annular die, and the temperature inside the annular die was controlled at 200 ° C. Further, a 20-μm mesh basket-shaped stainless steel filter was mounted between the screw tip of the extruder and the die.
The seamless film thus obtained was cut at 350 mm intervals in a direction perpendicular to the axial direction (circumferential direction) to obtain a seamless semiconductive belt of this width.

Example 3 100 parts by weight of a polyvinylidene fluoride resin, 30 parts by weight of a block type ion conductive polymer Perestat 6321 (manufactured by Sanyo Chemical Industries, Ltd.) having polyether as a main segment, and acetylene black 2 2.9 parts by weight were blended in a nitrogen gas atmosphere using a hybridization system, and the resulting blend was subsequently charged into an extruder having a twin screw in a nitrogen gas atmosphere to produce a pellet-shaped raw material. did.
This pellet-form raw material was put into a φ65 mm extruder with L / D = 19, led to a spiral annular die through a gear pump, and melt-extruded into a tube directly below the slit opening.
Next, the melt-extruded product was cooled while being regulated by a sizing sleeve in a submerged vacuum water cooling tank having an inner diameter of 520 mm, and only the middle portion was nipped using 12 nip rolls having a width of 50 mm, and taken out so as not to make a fold.
The film was formed into a seamless film having a thickness of 160 μm and a diameter of 500 mm. Next, this seamless film was subjected to 3% each in the longitudinal and circumferential directions at a temperature of 130 ° C.
Stretched. At this time, the four-split heater is arranged stepwise in the circumferential direction of the annular die, and the temperature in the annular die is set to 200 ° C.
Was controlled. Further, a 20-μm mesh basket-shaped stainless steel filter was mounted between the screw tip of the extruder and the die. The seamless film thus obtained was cut at 350 mm intervals in a direction perpendicular to the axial direction (circumferential direction) to obtain a seamless semiconductive belt of this width.

Next, the configuration of a seamless semiconductive belt of a comparative example prepared for comparison with the seamless semiconductive belt of the present invention will be described.

Comparative Example 1 100 parts by weight of ethylene-tetrafluoroethylene copolymer and 10 parts by weight of Ketjen black were blended in a nitrogen gas atmosphere using a hybridization system. The obtained blend was subsequently charged into an extruder having a twin screw in nitrogen gas, and pelletized raw materials were granulated. This pellet-shaped raw material
It was introduced into a φ65 mm extruder with L / D = 24, guided to an annular die via a gear pump, and melt-extruded into a tube.
Next, the melt-extruded product was taken out while being cooled from the inside by a sizing sleeve having an outer diameter of 60 mm, and a film having a thickness of 160 μm was formed. At this time, the temperature in the annular die was controlled at 300 ° C. further,
A 20 μm mesh basket-shaped stainless steel filter was attached between the screw tip of the extruder and the die. The seamless film obtained in this way was
The film was stretched 3% in the axial and circumferential directions at a temperature of ° C. Next, the stretched film was cut at intervals of 350 mm to obtain a seamless semiconductive belt of this width.

Comparative Example 2 100 parts by weight of a polyvinylidene fluoride resin, 0.8 parts by weight of (C ₃ H ₇ ) ₄ NSO ₄ (C ₆ F ₁₃ ) and 0.2 parts by weight of acetylene black were mixed with nitrogen. The mixture was blended in a gas atmosphere using a hybridization system, and the obtained blend was subsequently charged into an extruder having a twin screw in a nitrogen gas atmosphere to produce a pellet-shaped raw material. This pellet-shaped raw material is L / D = φ19.
It was charged into a 65 mm extruder, guided into a spiral annular die through a gear pump, and melt-extruded into a tube directly below the slit opening. Next, the melt-extruded material was used for the inner diameter 5
Cooling while regulating with a sizing sleeve in a 20 mm immersion vacuum water cooling tank, nip only the middle part using 12 nip rolls with a width of 50 mm, take off so as not to make folds, seamless film with a thickness of 160 μm and a diameter of 500 mm The film was formed in the shape of Next, the seamless film was stretched at a temperature of 130 ° C. in the machine direction and the circumferential direction by 3% each. At this time, the four-piece heater was arranged stepwise in the circumferential direction of the annular die, and the temperature inside the annular die was controlled at 200 ° C. Further, a 20-μm mesh basket-shaped stainless steel filter was mounted between the screw tip of the extruder and the die.
The seamless film thus obtained was cut at 350 mm intervals in a direction perpendicular to the axial direction (circumferential direction) to obtain a seamless semiconductive belt of this width.

Examples 1 to 3 described above and Comparative Examples 1 and 2
Table 1 summarizes the configuration of the seamless semiconductive belt according to the present invention.

[0064]

[Table 1]

{Comparison Evaluation of Examples and Comparative Examples} Next, the results of comparative evaluation of the seamless semiconductive belts obtained in Examples 1 to 3 and Comparative Examples 1 and 2 will be described. Each of the examples and comparative examples was evaluated by measuring the resistance and the reflectance of the obtained seamless semiconductive belt, and incorporating the image into an image forming apparatus as shown in FIG. 2 to form an image. did. At this time, the resistance measurement and the reflectance measurement were performed by the following methods.

{Resistance Measurement Method} A high resistance measuring machine (Hiresta manufactured by Mitsubishi Chemical Corporation) was used for measuring the volume resistance value. An HA probe was used as a probe serving as an electrode. The applied voltage was 500 V. After applying this voltage for 30 seconds, the volume resistance was measured.

{Reflectance Measurement Method} A spectrophotometer (U4000 manufactured by Hitachi, Ltd.) was used for measurement of the reflectance of the belt surface. Light having a wavelength of 680 nm is used as incident light from the light source, and the incident light is made incident on the belt surface at an incident angle of 30 °, and the reflected light reflected at a reflection angle of 30 ° is received. Reflectance was measured as reflection intensity / incident intensity.

Table 2 shows the evaluation results. In addition, in Table 2, the comprehensive evaluation shows the result of judging whether or not the transfer belt is suitable for a high-quality image, and "○" indicates that the transfer belt is suitable, and "X" indicates that the transfer belt is not sufficiently suitable. Is shown.

[0069]

[Table 2]

When the seamless semiconductive belts obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were used as transfer belts in a full-color image forming apparatus as shown in FIG. In addition, because the volume resistance of the seamless semiconductive belt is uniform and the reflectivity is sufficiently large,
High quality images could be obtained.

However, in the seamless semiconductive belt shown in Comparative Example 1, the conductivity was obtained depending on the electronic conductivity of the conductive carbon black, and the volume resistance was 1 × 10 ^10-
Since the fluctuation width is large and uneven at 1 × 10 ¹¹ Ωcm, when used as a transfer belt of a full-color image forming apparatus,
Image defects such as color omission and color unevenness have occurred.

In the seamless semiconductive belt shown in Comparative Example 2, the initial reflectance was as large as 45%.
When the A4 (landscape) paper was passed, the reflectance decreased with time. In this evaluation, after passing 2000 sheets, the reflectance of the seamless semiconductive belt was 25%.
Down to This is because, in the initial state, when the reflectance was measured, light from the light source passed through the transfer belt, and the transmitted light was reflected by the back surface of the belt, and the reflected light was also incident on the sensor. Although reflected light was detected,
It is considered that after passing 2,000 sheets, the amount of reflected light from the back surface incident on the sensor was reduced due to changes in the surface roughness of the back surface. When the seamless semiconductive belt of Comparative Example 2 is used as a transfer belt of a full-color image forming apparatus, when performing automatic correction of registration using the above-described photosensor and control of toner density, It is difficult to satisfactorily perform correction and control because the detection result of the photosensor fluctuates in the end. Therefore, when this seamless semiconductive belt is used as a transfer belt for image formation,
It is difficult to form a high quality image due to misregistration of the toner image or inappropriate toner density.

[0073]

As described above, the seamless semiconductive belt according to the present invention has excellent resistance uniformity, and can maintain a good reflectance without causing a change with time. Therefore, the seamless semiconductive belt of the present invention is very effective as a functional belt such as a transfer belt or an intermediate transfer belt used in an image forming apparatus for forming a high quality image. By using the belt, it is possible to provide an image forming apparatus that can stably form high-quality images, has excellent durability, and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a general example of an image forming apparatus.

FIG. 2 is a schematic configuration diagram of a general example of a full-color image forming apparatus.

FIG. 3 is a diagram illustrating a detection method used to perform automatic correction of registration and control of toner density in the full-color image forming apparatus of FIG. 2;

FIG. 4 is a schematic structural view of a full-color image forming apparatus using a seamless semiconductor belt as a transfer belt according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 101 photosensitive drum 102 charging charger 103 optical writing device 105 developing device 106 toner 6, 107, 206 transfer belt 108, 109, 111 stretching roller 110 drive roller 112, 205 transfer paper 113 paper charging adsorber 114 transfer charger 115, 207 Fixing device 201 Image forming device (M) 202 Image forming device (C) 203 Image forming device (Y) 204 Image forming device (Bk) 302 Registration mark 303 Light source 304 Photo sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H200 JB07 JB45 JB46 JC04 JC15 JC16 MA02 MA14 MA20 MB02 MB04 4F071 AA01 AA15X AA26 AA26X AA27X AA31 AA36 AA51 AA60 AA75 AB03 AC12 AE09 AE15 AF37YXAB12 BC BG07W BH02W BP00W CH02W CM04W DA036 EN137 FD096 FD117 GM01

Claims (5)

[Claims] 1. A seamless semiconductive material comprising a fluorine-based thermoplastic resin composition containing a colorant and containing an ion conductive additive or an ion conductive polymer and having a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm. belt. 2. The method according to claim 1, wherein the fluorine-based thermoplastic resin is ethylene-
Ethylene tetrafluoride copolymer and / or ethylene-3
The seamless semiconductive belt according to claim 1, which is a fluorinated ethylene copolymer. 3. The seamless semiconductive belt according to claim 1, wherein the fluorine-based thermoplastic resin is polyvinylidene fluoride. 4. The seamless semiconductive belt according to claim 1, wherein the coloring additive is carbon black. 5. An addition amount A of the carbon black used as the coloring additive is 0.2 <A <3 parts by weight with respect to 100 parts by weight of the fluorine-based thermoplastic resin.
The seamless semiconductive belt according to claim 4.