JP2002214927A - Intermediate transfer body and transfer member, method for manufacturing them and image forming device using them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer body and a transfer member by which the occurrence of transfer unevenness at a transfer time from a first image carrier to the intermediate transfer body and also at a transfer time from the intermediate transfer body to a second image carrier and the occurrence of leakage and a defective image in the case of applying high voltage are prevented. SOLUTION: In the transfer member used in a transfer device to electrostatically transfer a toner image formed on the intermediate transfer body or the first image carrier used in an image forming device by which an image formed on the first image carrier is transferred to the second image carrier after transferring it on the intermediate transfer body to the second image carrier, a material constituting the intermediate transfer body and the transfer member incorporates a filler and surface processing is applied to the filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an intermediate transfer member and a transfer member, a method of manufacturing the intermediate transfer member and a transfer member, and an image forming apparatus using the intermediate transfer member and a transfer member.

[0002]

2. Description of the Related Art An image forming apparatus using an intermediate transfer member includes:
A color image forming apparatus, a multi-color image forming apparatus, or a color image forming apparatus that sequentially transfers a plurality of component color images of color image information or multi-color image information and outputs an image formed product by combining and reproducing the color image or the multi-color image. It is effective as an image forming apparatus having a function and a multicolor image forming function.

FIG. 1 is a schematic view showing an example of an image forming apparatus using an intermediate transfer belt as an intermediate transfer member.

FIG. 1 is a cross-sectional view of a main part of a color image forming apparatus (copier or laser beam printer) using an electrophotographic process. An elastic body is used.

In FIG. 1, reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) which is repeatedly used as a first image bearing member. It is driven to rotate at a peripheral speed (process speed).

The photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by a primary charger 2 in the course of rotation, and then is subjected to image exposure means (not shown) (a color separation / imaging exposure optical system for a color original image, A first color component image of a target color image (e.g., a scanning exposure system using a laser scanner that outputs a laser beam that is modulated in accordance with a time-series electric digital pixel signal of image information). ,
An electrostatic latent image corresponding to the yellow component image is formed.

Then, the electrostatic latent image is developed by a first developing device (yellow developing device 41) with yellow toner Y as a first color. At this time, the developing units of the second to fourth developing units (the magenta developing unit 42, the cyan developing unit 43, and the black developing unit 44) are turned off and do not act on the photosensitive drum 1, The first color yellow toner image is not affected by the second to fourth developing units 42, 43, and 44.

The intermediate transfer belt 20 is driven to rotate clockwise at the same peripheral speed as the photosensitive drum 1. The first color yellow toner image formed and carried on the photosensitive drum 1 is applied from the primary transfer roller 62 to the intermediate transfer belt 20 while passing through the nip between the photosensitive drum 1 and the intermediate transfer belt 20. The intermediate transfer (primary transfer) is sequentially performed on the outer peripheral surface of the intermediate transfer belt 20 by the electric field formed by the primary transfer bias.

The surface of the photosensitive drum 1 after the transfer of the yellow toner image of the first color corresponding to the intermediate transfer belt 20 is cleaned by the cleaning device 13.

Hereinafter, similarly, the second color magenta toner image, the third color cyan toner image, and the fourth color black toner image are sequentially superimposed on the intermediate transfer belt 20 and transferred to correspond to the target color image. Thus, a combined color toner image is formed.

Reference numeral 63 denotes a secondary transfer roller which is supported in parallel with the secondary transfer opposing roller 64 and is disposed on the lower surface of the intermediate transfer belt 20 so as to be separated therefrom.

A primary transfer bias for sequentially superimposing transfer of the first to fourth color toner images from the photosensitive drum 1 to the intermediate transfer belt 20 is applied from a bias power supply 29 with a polarity (+) opposite to that of the toner. You. The applied voltage is, for example, +100
V to 2 kV. In the primary transfer process of the toner images of the first to third colors from the photosensitive drum 1 to the intermediate transfer belt 20, the secondary transfer roller 63
It is also possible to move away from zero.

In transferring the composite color toner image transferred onto the intermediate transfer belt 20 to a transfer material P as a second image carrier, the secondary transfer roller 63 is brought into contact with the intermediate transfer belt 20 and The transfer material P is fed from the paper feed roller 11 through the transfer material guide 10 to the contact nip between the intermediate transfer belt 20 and the secondary transfer roller 63 at a predetermined timing, and the secondary transfer bias is It is applied to the next transfer roller 63. Then, the composite color toner image is transferred (secondary transfer) from the intermediate transfer belt 20 to the transfer material P as the second image carrier by the secondary transfer bias.

The transfer material P to which the toner image has been transferred is introduced into the fixing device 15 and is fixed by heating. And the transfer material P
After the transfer of the image to the transfer member P, the cleaning charging member 7 is brought into contact with the intermediate transfer belt 20 and is not transferred to the transfer material P by applying a bias having a polarity opposite to that of the photosensitive drum 1 to the cleaning charging member 7. And the intermediate transfer belt 2
A charge having a polarity opposite to that of the photosensitive drum 1 is applied to the toner (transfer residual toner) remaining on the photosensitive drum 1. Reference numeral 26 denotes a bias power supply.

The transfer residual toner is electrostatically transferred to the photosensitive drum 1 in a nip portion with the photosensitive drum 1 and in the vicinity thereof, so that the intermediate transfer belt 20 is cleaned.

In a color electrophotographic apparatus having an image forming apparatus using the above-mentioned intermediate transfer belt, a second image carrier is stuck or adsorbed on a transfer drum, which is a conventional technique, and the first image carrier is attached thereto. A color electrophotographic apparatus having an image forming apparatus for transferring an image from the body, for example,
As compared with the transfer device described in Japanese Patent Application Laid-Open No. 3-301960, the transfer material as the second image carrier requires some processing and control (for example, gripping by a gripper, suctioning, giving a curvature, etc.). Since the image can be transferred from the intermediate transfer belt without using a thin paper (40 g / m ² paper) such as an envelope, a postcard, a label paper, etc.
It has the advantage that the second image carrier can be selected in various ways, regardless of its width, length, or thickness, up to m ² paper).

Due to such advantages, color copiers and color printers using an intermediate transfer belt have already begun to operate in the market.

Next, an example of an image forming apparatus using a transfer belt as a transfer member is shown in FIG.

The image forming apparatus shown in FIG. 2 is one type of a color image forming apparatus of the color separation image superimposing transfer system, in which toner images of different colors are formed on a plurality of photoconductors, respectively. The toner images on the respective photoconductors are transferred while being positioned on one transfer material that is sequentially contacted and conveyed, whereby a full-color image is obtained.

The image forming apparatus shown in FIG.
0, four image forming units I, II, III, and IV are arranged side by side as electrophotographic process means.
To IV are photosensitive drums 301Y and 301 as image carriers.
M, 301C, 301BK, primary charging rollers 302Y, 302M, 302C, 302BK as primary charging devices,
The exposure unit 303Y, 303M, 303C, 303BK includes developing units 304Y, 304M, 304C, 304BK and cleaners 305Y, 305M, 305C, 305BK. The developing units 304Y, 304M,
304C and 304BK contain yellow (Y), magenta (M), cyan (C), and black (BK) toners, respectively.

A transfer device 310 is provided below the image forming units I to IV.
Endless transfer belt 314 stretched between drive roller 311 and driven roller 312 and tension roller 313
And the photosensitive drums 301Y and 301 of the image forming units I to IV.
M, 301C, and 301BK are each configured to include a transfer charger 315 disposed to face each other.

On the other hand, at the bottom of the apparatus main body 320, a cassette 306 having a plurality of recording papers P stacked therein as a recording medium is installed, and the recording papers P in the cassette 306 are fed by paper feed rollers 307. Is sent out one by one,
The sheet is conveyed to the registration roller 309 via the conveyance guide 308.

The recording paper P in the apparatus main body 320 is
The separation charging device 316 and the fixing device 31
7, and a paper discharge tray 318 is attached outside the apparatus main body 320.

In each of the image forming units I to IV, the photosensitive drums 301Y, 301M, 301C, and 301BK are driven to rotate at a predetermined speed in the direction of the arrow shown in the figure, and these are primary charging rollers 302Y, 302M, 302C, and 302BK.
Are uniformly charged. The photosensitive drums 301Y, 301M, 301 thus charged are processed.
When the exposure units 303Y, 303M, 303C, and 303BK perform exposure on C and 301BK in accordance with image information, the photosensitive drums 301Y, 301M, and 301BK.
An electrostatic latent image is formed on each of C and 301BK, and each electrostatic latent image is developed by each of the developing units 304Y, 304M, 304C and 304BK to form a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image, respectively. It is visualized.

On the other hand, the recording paper P conveyed from the cassette 306 to the registration roller 309 via the conveyance guide 308 as described above is sent out to the transfer device 310 at a proper timing by the registration roller 309, and the transfer paper 310 is transferred. The toner is attracted to the belt 314 and moves together with the belt 314 to pass through the image forming units I to IV. In the process, the yellow toner image, the magenta toner image, the cyan toner image, and the The black toner image is transferred in an overlapping manner.

The recording paper P, to which the respective color toner images have been transferred as described above, is discharged by the separation charger 316 and separated from the transfer belt 314.
The sheet is conveyed to the printer 17 and is heated and fixed by the color toner image. Finally, the sheet is discharged from the apparatus main body 320 and stacked on the sheet discharge tray 318. In the color image forming apparatus using the transfer belt, the color image is formed in one process because the respective color images are superimposedly transferred while sequentially transferring the transfer paper to each recording device.
There is an advantage that the image output time is fast. Due to such advantages, a color copying machine, a color printer, and the like using a transfer belt have already started operating in the market.

[0027]

However, a color electrophotographic apparatus using such an intermediate transfer belt or a transfer belt fully utilizes the above-mentioned advantages, and is expected and satisfied by the user. It does not function as a device. Providing an image forming apparatus using such an intermediate transfer belt or a transfer belt still has the following problems to be overcome.

That is, a filler may be mixed into the intermediate transfer belt or the transfer belt to make it conductive or to improve toner releasability. When the surface energy of this filler is higher than the surface energy of the resin, The fillers may be aggregated with each other. As a result, the dispersibility and the diffusibility of the fillers are deteriorated, and local concentration unevenness occurs. In some cases, bumps or the like are generated on the belt surface, and image defects due to the bumps may occur, or leaks due to the bumps may occur, making it difficult to obtain a satisfactory product. In some cases, the cost is increased due to a decrease in the yield.

The present invention has been made in view of the above-mentioned problems, and its purpose is to perform the transfer from the first image bearing member to the intermediate transfer member and the transfer from the intermediate transfer member to the second image bearing member. An intermediate transfer member and a transfer member capable of preventing the occurrence of transfer unevenness during transfer and the occurrence of leakage and image defects when a high voltage is applied, a method of manufacturing the intermediate transfer member and the transfer member, and an intermediate transfer member and a transfer member. An object of the present invention is to provide an image forming apparatus using the same.

[0030]

In order to achieve the above object, the present invention provides a method for transferring an image formed on a first image carrier onto an intermediate transfer member, and then transferring the image onto a second image carrier. Transfer used in a transfer device that electrostatically transfers an intermediate transfer member used in an image forming apparatus or a toner image formed on a first image carrier to a second image carrier. The member is characterized in that the intermediate transfer member and the transfer member contain a filler in a constituent material, and the filler is subjected to a surface treatment.

Further, the present invention is characterized in that the intermediate transfer member or the transfer member is manufactured as a seamless belt extruded with an annular die.

Further, according to the present invention, there is provided an image forming apparatus or a first image forming apparatus for transferring an image formed on a first image bearing member onto an intermediate transfer member and further transferring the image on a second image bearing member. In an image forming apparatus for electrostatically transferring a toner image formed on a carrier to a second image carrier, a filler is contained in a material constituting the intermediate transfer body and the transfer member, and the filler is It is characterized by surface treatment.

[0033]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

According to the present invention, an image formed on a first image bearing member is transferred to an intermediate transferring member, and then further transferred onto a second image bearing member. A transfer member for electrostatically transferring a toner image formed on the image carrier to the second image carrier, wherein the intermediate transfer member and the transfer member include filler in a material constituting the transfer member. And subjecting the filler to a surface treatment.

That is, by subjecting the filler to a surface treatment, the surface activity of the filler is reduced, the aggregation of the filler is prevented, and the dispersion of the filler is stabilized. And preventing leakage.

As the filler used in the present invention, for example, when controlling the resistance, for example, carbon black, graphite,
Examples include, but are not limited to, aluminum-doped zinc oxide, tin oxide-coated titanium oxide, tin oxide, tin oxide-coated barium sulfate, potassium titanate, aluminum metal powder, nickel metal powder, and the like. When it is desired to impart lubricity to the belt, as a highly lubricating filler, for example, ethylene tetrafluoride resin, ethylene trifluoride resin, ethylene tetrafluoride hexafluoropropylene resin, vinyl fluoride resin,
Silicone compounds such as vinylidene fluoride resin, ethylene dichloride ethylene chloride resin and their copolymers, fluorocarbon, silicone resin, silicone rubber, silicone elastomer, polyethylene, polypropylene, polystyrene, acrylic resin, nylon resin, Phenolic resin,
One or more of epoxy resins and their compounds, mixtures, inorganic substances such as silica and alumina are appropriately selected, and particularly, tetrafluoroethylene resin and tetrafluoroethylene hexafluoropropylene resin are preferable. preferable. In addition, it is not necessarily limited to these.

In addition, fillers such as barium sulfate and various whiskers can be used according to other purposes.

As the surface treatment agent used in the present invention, a surface treatment agent containing at least one of silicon, fluorine, titanium and aluminum is preferable. The surface treatment agents containing these elements include the following, which can be selected according to the purpose of use.

The surface treatment agent used in the present invention is preferably silicone oil. Usually, in order to disperse the filler well, a dispersing agent such as wax or metal soap is used, but these need to be equal to or more than the amount of the filler to be used, for example, realizing conductivity. If it is desired, the amounts of the conductive agent and the dispersant may be close to half of the total amount, and the physical properties of the mixture may be significantly reduced.

However, since the above-mentioned silicone oil has a low surface tension and can cover the filler surface even in a small amount, the surface treatment can be carried out in a much smaller amount than a usual dispersant, and the physical properties of the mixture can be reduced. Can be improved without reducing the dispersibility of the filler. Further, since the silicone oil has its methyl group oriented on the surface of the intermediate transfer member and the transfer member, the effect of improving the surface releasability can be obtained at the same time.

The silicone oils described above include dimethyl silicone oil, phenylmethyl silicone oil, chlorophenyl silicone oil, alkyl silicone oil, fluorosilicone oil, polyoxyalkylene-modified silicone oil, fatty acid ester-modified silicone oil, methyl hydrogen silicone oil, silanol Examples include, but are not limited to, group-containing silicone oil, alkoxy group-containing silicone oil, acetoxy group-containing silicone oil, amino-modified silicone oil, carboxylic acid-modified silicone oil, and alcohol-modified silicone oil.

The surface treatment agent used in the present invention is preferably a fluorine-based surfactant. Fluorosurfactants also have a low surface tension, similar to linear silicon compounds, and can cover the filler surface even in a small amount, so surface treatment can be performed in a much smaller amount than ordinary dispersants. ,
The dispersibility of the filler can be improved without lowering the physical properties of the mixture.

Examples of the above-mentioned fluorine-based surfactant include ammonium perfluoroalkyl sulfonic acid, potassium perfluoroalkyl sulfonic acid, potassium perfluoroalkyl carboxylate, and perfluoroalkyl quaternary carboxylic acid.
Quaternary ammonium iodide, perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl esters, and the like, but are not limited thereto.

The surface treatment agent used in the present invention is preferably a coupling agent. Since the coupling agent can reduce the surface activity of the filler by reacting the hydrophilic group side with the filler and releasing an organic chain on the filler surface, the dispersibility of the filler can be improved.

Further, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, etc. are selected according to the use, but are not limited thereto.

The silane coupling agent has high reactivity with silica, talc, barium sulfate, carbon, and the like, and is therefore preferred when these are used. Examples of the silane coupling agent include vinyl trichlorosilane, vinyl triethoxy silane, and vinyl-tris- (β-methoxyethoxy).
Silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N
-Β- (aminoethyl) -7-aminopropyltrimethoxysilane, N- (dimethoxydimethylsilylpropyl) -ethylenediamine, N- (trimethoxysilylpropyl) -ethylenediamine, and the like, but are not limited thereto.

Titanate-based coupling agents have high reactivity with titanium oxide, calcium carbonate, carbon black and the like, and are therefore preferred when they are used. Examples of titanate-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl trioctanoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl (N-aminoethyl- (Aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate, and the like, but are not limited thereto.

Aluminum-based coupling agents have high reactivity with carbon black, titanium oxide, and the like, and are therefore preferred when they are used. Examples of the aluminum-based coupling agent include, but are not limited to, acetoalkoxyaluminum diisopropylate.

When the surface treatment of the present invention is carried out, examples of the treatment method include a dry method and a wet method. Examples of the dry method include, but not limited to, a method of performing a surface treatment by mixing a surface treating agent and a filler with various mixers or the like.
Examples of the wet method include, but not limited to, a method in which a surface treatment agent is diluted with various solvents, a filler is added to the solution, mixed, and then the solvent is removed with various dryers. The wet method is more preferable because the surface treatment agent is uniformly attached to the filler surface, but the cost is high, so that a dry method or a wet method can be used depending on the purpose.

In order to confirm that the surface treatment has been performed on the filler which has been surface-treated with these surface treatment agents, the cross section of the molded product is observed with an electron microscope, and the surface of the filler is subjected to X-ray microanalysis (hereinafter referred to as X-ray microanalysis). , SEM-XMA) and detecting the elements of the surface treatment agent.

[0051] The volume resistivity of the intermediate transfer member and the transfer member used in the present invention is preferably from 10 ⁰ Omega is 10 ¹⁴ Omega, and particularly preferably from 10 ⁶ ~10 ¹² Ω.
The surface resistivity of the intermediate transfer member and the transfer member used in the present invention is preferably from 10 ⁰ to 10 ¹⁷ Omega, particularly 1
It is preferably 0 ⁶ ~10 ¹⁴ Ω.

In order to function as the intermediate transfer member of the present invention, it is desirable that the maximum value of the volume resistance and the surface resistance of each part of the belt be within 100 times the minimum value. In particular, it is desirable that the maximum value of the volume resistance in the circumferential direction of the belt be within 100 times the minimum value. This is because, when the maximum value of the volume resistance in the circumferential direction of the belt is larger than 100 times the minimum value, transfer unevenness occurs in the circumferential direction or when a voltage is applied to a plurality of locations, a part of the voltage is applied. This is because current may flow from one portion to another applied portion through a portion having a low resistance in the circumferential direction, and normal operation may not be performed due to disturbance of voltage control at other portions.

It is desirable that the maximum value of the surface resistance in the circumferential direction of the belt be within 100 times the minimum value. This is because when the maximum value of the surface resistance in the circumferential direction of the belt is larger than 100 times the minimum value, transfer unevenness occurs in the circumferential direction, or when a voltage is applied at a plurality of locations, a part of the voltage is applied. This is because current flows from one portion to another applied portion through a portion having a low resistance in the circumferential direction, and normal operation cannot be performed due to disturbance of voltage control at other portions.

It is desirable that the maximum value of the volume resistance in the longitudinal direction of the belt be within 100 times the minimum value.
If the maximum value of the volume resistance in the longitudinal direction of the belt is larger than 100 times the minimum value, uneven transfer may occur in the longitudinal direction, or an excessive current may flow into the minimum resistance portion, and the device may malfunction. Because there is.

It is desirable that the maximum value of the surface resistance in the longitudinal direction of the belt be within 100 times the minimum value.
If the maximum value of the surface resistance in the longitudinal direction of the belt is larger than 100 times the minimum value, uneven transfer occurs in the longitudinal direction, or a predetermined charge is applied to the residual toner, and the toner is returned onto the photosensitive drum. This is because, when used, an excessive current flows from the charging member that applies the electric charge to the portion having the minimum surface resistance of the belt, and a sufficient electric field does not act in the longitudinal direction of the portion, so that cleaning unevenness may occur in the longitudinal direction. .

In order to achieve the above resistance range, the compatibility between the resin of the present invention and the resistance control agent, the amount of the resistance control agent, the process conditions at the time of dispersion processing and the belt production shown in FIG. By examining each process condition in detail, it can be within the above range.

In the present invention, the volume resistance and the surface resistance are not merely differences in measurement conditions but show completely different electric characteristics. That is, when the voltage / current applied to the intermediate transfer member is applied in the thickness direction, the movement of the charge of the intermediate transfer member mainly depends on the structure and physical properties inside the intermediate transfer member, in other words, the layer structure of the intermediate transfer member. Are determined by the type and dispersion state of the intermediate transfer member, the additive, and the resistance control agent.

On the other hand, when a voltage / current is applied so that charges are transferred only on the surface of the intermediate transfer member, the additive and resistance on the surface hardly depend on the internal structure and layer structure of the intermediate transfer member. Charging and discharging are determined only by the proportion of the control agent.

However, in the present invention, the transfer resistance is maintained so that these two resistances are in mutually preferable ranges. The uniform transferability of the intermediate transfer member and no defects such as filming are observed over the entire image. This is a necessary and sufficient condition for obtaining good image quality.

The method for measuring the electrical resistance of the intermediate transfer member of the present invention is as follows.

<Measuring machine> Resistance meter; Ultra-high resistance meter R8340A (manufactured by Advantest) Sample box: Material box TR42 for ultra-high resistance measurement (manufactured by Advantest) However, the main electrode has a diameter of 25 mm, and the guard ring electrode has an inner diameter. 41 mm and an outer diameter of 49 mm.

<Sample> The belt is cut into a circle having a diameter of 56 mm. After cutting, one surface is provided with electrodes on the entire surface by a Pt-Pd vapor deposition film, and the other surface is a Pt-Pd vapor deposition film on a main electrode having a diameter of 25 mm, an inner diameter of 38 mm, and an outer diameter of 50 mm.
mm guard electrode is provided. The Pt-Pd vapor-deposited film can be obtained by performing a vapor deposition operation for 2 minutes with mild sputter E1030 (manufactured by Hitachi, Ltd.). The sample after the vapor deposition operation is used as a measurement sample.

<Measurement Conditions> Measurement atmosphere: 23 ° C./55%. The measurement sample is left in an atmosphere of 23 ° C./55% for 12 hours or more.

Measurement mode: Program mode 5 (discharge 10 seconds, charge and measure 30 seconds) Applied voltage: 1 to 1000 (V) The applied voltage is applied to the intermediate transfer member and the transfer member used in the image forming apparatus of the present invention. It can be arbitrarily selected from 1 to 1000 V which is a part of the range of the applied voltage. Further, the applied voltage used can be changed as appropriate within the range of the applied voltage according to the resistance value, thickness, dielectric breakdown strength and the like of the sample. Further, if the volume resistivity and the surface resistance at a plurality of points measured at any one of the applied voltages are included in the resistance range of the present invention, it is determined that the resistance range is the object of the present invention. .

FIG. 3 shows an example of a molding apparatus according to the present invention.

The device basically comprises, but is not limited to, an extruder, an annular die and, if necessary, an air blowing device.

The molding apparatus shown in FIG. 3 includes two extruders 100 and 110 for molding a two-layer belt.
In the present invention, at least one group may be provided.

Next, a method for producing a single-layer intermediate transfer member will be described.

First, after preliminarily mixing a molding resin, a conductive agent, an additive and the like based on a desired prescription, the kneaded and dispersed molding raw material is put into a hopper 120 provided in the extruder 100. The extruder 100 has a melt viscosity at which the raw material for molding can be used to form a belt in a subsequent process,
The set temperature and the screw configuration of the extruder are selected so that the raw materials are evenly dispersed. The raw material for molding is melt-kneaded in the extruder 100 to form a molten material, and enters the annular die 140. The annular die 140 is used for the air introduction path 1
50 is provided, and when the air is blown into the annular die 140 from the air introduction path 150, the melt that has passed through the annular die 140 expands and expands in the radial direction. The molding may be performed without blowing air into the air introduction path 150.

The expanded molded body is pulled up while being cooled by the cooling ring 160. At this time, the final shape and size 180 are determined by passing between the dimensional stability guides 170. Further, by cutting this into a desired width, the intermediate transfer belt 190 of the present invention can be obtained.

The extrusion molding ratio in the present invention indicates the ratio of the diameter of the annular die 140 to the diameter of the molded die 180 which has passed through the annular die and whose diameter has expanded and expanded to obtain the molded shape 180. That is, the extrusion molding ratio = the diameter after molding / the diameter of the annular die.

Although the above description has been made with respect to a single-layer belt, in the case of a two-layer belt, as shown in FIG.
The kneaded melt of the extruder 110 is fed to the annular die 140 for two layers simultaneously with the kneaded melt of the extruder 110, and the two layers are simultaneously expanded and expanded to obtain a two-layer belt. In the case of three or more layers, an extruder may be prepared according to the number of layers.

FIGS. 4 to 6 show two-layer and three-layer intermediate transfer belts. Thus, the present invention is not limited to a single layer,
It is possible to mold a multi-layered intermediate transfer belt in a single-step process and with high dimensional accuracy in a short time. The fact that short-time molding is possible suggests that mass production and low-cost production are sufficiently possible.

It is preferable to make the formed belt thinner than the die gap of the annular die. This means that, for example, when a 150 μm film is to be produced with a 150 μm die gap, the die gap is set to 50 μm.
When the film is moved by m, the film changes by 50 μm as it is, but it is difficult to actually adjust the die gap in 1 μm units, and as a result, a film having a non-uniform film thickness is easily formed.

However, for example, when a die gap of 150 μm is formed with a die gap of 1.5 mm, the die gap is 50 μm.
Even in the case of the deviation, the final deviation of the film thickness is 1/10, and the actual deviation of the film thickness is 5 μm. As a result,
Finally, a film can be made with high accuracy. Therefore, it is desirable to make the formed belt thinner than the die gap of the annular die.

As a method for making the thickness of the formed belt thinner than the die gap of the annular die, the discharge speed of the tubular molten material discharged from the end of the annular die by extrusion of an extruder is more than the discharge speed of the film. There is a way to increase the pick-up speed. For example, the extrusion speed of a tubular melt extruded from the tip of the die without taking out the film is 1 m / min, the diameter of the die is the same as the diameter of the film to be formed, and the take-up speed is 1 m / min.
At 0 m / min, the film thickness is 1/10 of the die gap of the annular die, and the thickness of the formed belt can be made smaller than the die gap of the annular die.

Further, as a method of making the thickness of the formed belt smaller than the die gap of the annular die, there is a method of making the extrusion molding ratio larger than 1. That is, even if the take-up speed is equal to the extrusion speed by making the film diameter larger than the diameter of the die, the film thickness becomes thinner by the increase in the diameter. The maximum value of the molding ratio at this time is desirably 4.0 or less. If it is larger than this, the stability of the expanded film may deteriorate, and at this time, the film thickness may become unstable.

Even if the extrusion molding ratio is set to 1 or less, the thickness of the formed belt can be made smaller than the die gap of the annular die by increasing the take-up speed. This is useful under conditions such as low molecular weight of the resin. That is, when the viscosity at the time of melting is low, if the molding ratio is larger than 1, a hole may be formed in the film, and in this case, the molding ratio is 1
By doing so, the thickness of the formed belt can be made smaller than the die gap of the annular die. At this time, the minimum value of the molding ratio is desirably 0.5 or more. If it is less than 0.5, it is necessary to greatly increase the film take-up speed during film take-up, which is not preferable because molding becomes unstable.

As a method of setting the extrusion ratio to be larger than 1, a method of expanding the tube by blowing a gas having a pressure equal to or higher than the atmospheric pressure into the tubular molten material discharged from the end of the annular die by the extrusion of the extruder. There is a molding method in which the molding is performed continuously while being performed. in this case,
When the gas having a pressure higher than the atmospheric pressure is blown into the tube, the tube expands, and the extrusion ratio can be made larger than 1. In addition to air, nitrogen, carbon dioxide, argon and the like can be selected as the gas blown at this time, but it does not sleep.

When cutting to a predetermined width, it is preferable that the tubular film discharged from the tip of the annular die by extrusion of an extruder is continuously cut in a direction perpendicular to the longitudinal direction. This is because, when cutting continuously, there is a time difference between the beginning and end of cutting when the cutter teeth are stopped while cutting, and the cutting is performed diagonally. Is increased. As a method for continuously cutting the tubular film in the vertical direction toward the longitudinal direction, there is a method using a cutter device which moves at the same speed as the tube pushing speed, but this is not sleepy.

The range of the thickness of the intermediate transfer member after molding is 45 to 45.
300 μm is preferred, and more preferably 50 to 270 μm
m, more preferably 55 to 260 μm. 300μ
When the belt having this large film thickness is used as an intermediate transfer member, a thickness of at least m prevents smooth running due to considerable rigidity and poor flexibility, and the belt is fortunate and deviated during running. It will be easier. A thickness of 45 μm or less has practical problems such as a decrease in the tensile strength as an intermediate transfer member, loosening during the rotation of the belt while being stretched, and gradual elongation.

In the production method of the present invention, the production of a belt of 45 μm or less is a thin layer, so that the electric resistance can be stabilized and the like can be dealt with, but it is not suitable because of the above-mentioned practical problems.

The extruder for extruding the tubular melt may be a twin screw extruder. In this case, since the conductive agent is directly charged into the twin-screw extruder and molded without previously compounding, the process is more complicated than the method of extruding after compounding the tetrafluoroethylene / perfluoroalkylvinyl ether copolymer resin. The cost can be reduced at a low cost. Also, because there are few processes,
The number of times of dispersion is reduced, and the resistance variation factor due to dispersion strength is reduced.
In addition, it goes without saying that the extruder used in the present invention may be a single-screw extruder, and various extruders can be used in various shapes and methods.

As the first image bearing member, it is preferable to use a photosensitive drum containing at least the outermost layer containing a fine powder of PTFE, since higher primary transfer efficiency can be obtained. This is because by containing the fine powder of PTFE,
This is considered to be because the surface energy of the outermost layer of the photosensitive drum is reduced, and the releasability of the toner is improved.

Hereinafter, the present invention will be described in detail with reference to examples.

Example 1 100 parts by weight of polypropylene resin (MI = 2) 17.5 parts by weight of conductive carbon black 0.5 part by weight of dimethyl silicone oil Of the above-mentioned composition, conductive carbon black and dimethyl silicone oil were mixed. After mixing with a Henschel mixer,
The mixture obtained by adding the polypropylene resin and further mixing was kneaded with a biaxial extrusion kneader, and this was further kneaded with a particle size of 2 to 3 mm to obtain a molding raw material (1).

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
By adjusting and extruding in the range of 80-200 ° C,
It was a melt. The melt is subsequently cooled to a die diameter of 100
mm and a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the die tip was 1 m / min. Further, there, air is blown in from the air introduction path 150 to expand and expand, and while taking up at a take-up speed of 5 m / min, the tube-shaped film is cut continuously at every 230 mm in a direction perpendicular to the longitudinal direction while being formed. In this way, a belt was obtained. The extrusion molding ratio at this time was 1.6. As a result, the final shape and dimensions were 160 mm in diameter, 150 μm in thickness, and belt width 230.
mm, and an intermediate transfer belt 190 was obtained. This is referred to as an intermediate transfer belt (1).

The central value of the measured resistance value of the intermediate transfer belt (1) was 1.5 × 10 ⁹ Ω. Further, by using an electric resistance measuring device, 100 V is applied to the intermediate transfer belt (1) as shown in FIG.
As shown in the figure, the electrical resistance variation in the belt was measured by measuring eight places, four places in the circumferential direction and two places in the axial direction at each position. It was in. Further, the resistance was measured by applying 500 V, but no leak occurred. This is presumably because the silicone oil had a high dispersing effect and no carbon aggregates were generated. In addition, the dispersion of the thickness measurement at the same position was larger than that of the formed belt because the die gap was wider and the control of the film thickness was easier.
The range was 0 μm ± 10 μm. Visual observation of the intermediate transfer belt (1) revealed no foreign matters such as bumps and fish eyes and poor molding on the surface. This intermediate transfer belt (1) was mounted on the full-color electrophotographic apparatus shown in FIG. 1, a full-color image was printed on 80 g / m ² paper, and the transfer efficiency was measured by defining the transfer efficiency as follows. .

Primary transfer efficiency (transfer efficiency from photosensitive drum to intermediate transfer belt) = image density on intermediate transfer belt /
(Transfer residual image density on photosensitive drum + image density on intermediate transfer belt) Secondary transfer efficiency (transfer efficiency from intermediate transfer belt to paper) =
Image density on paper / (image density on paper + transfer residual image density on intermediate transfer belt) In this embodiment, as the photosensitive drum 1, the outermost layer is made of PTFE.
Organic photosensitive drum (OPC photosensitive drum) containing fine powder of Therefore, high primary transfer efficiency is obtained,
Furthermore, high primary transfer efficiency was obtained also by the effect of improving the releasability of dimethyl silicone oil. Primary transfer efficiency, 2
The secondary transfer efficiencies were 97% and 95%, respectively.

The cleaning method for the intermediate transfer belt is a primary transfer simultaneous cleaning method using an elastic roller having a resistance of 1 × 10 ⁸ Ω for the charging member 7 for cleaning, and can continuously print 50,000 full-color images. went.

From the beginning, there is no unevenness in image density due to uneven resistance of the belt, no transfer omission due to leakage or the like even after 50,000 sheets have been used, and it is possible to obtain a good image free from defective cleaning. did it. Further, there was no toner filming on the surface, and no cracking, abrasion and abrasion occurred, and the surface properties were the same as those at the initial stage.

Further, the belt is cut after the endurance test, and
The cut surface was observed with an electron microscope, and especially when SEM-XMA was applied to the carbon surface, silicone atoms were detected. Thus, it was confirmed that the carbon surface was treated with silicone oil.

Example 2 100 parts by weight of polypropylene resin (MI = 2) 17.5 parts by weight of conductive carbon black 0.5 part by weight of potassium perfluoroalkylsulfonate Of the above composition, conductive carbon black and After mixing potassium perfluoroalkylsulfonate with a Henschel mixer, adding a polypropylene resin and further mixing the mixture, the mixture was added to a twin-screw extruder kneader attached in place of the single-screw extruder 100 shown in FIG. , And the mixture was extruded by adjusting the set temperature to a range of 180 to 200 ° C. to obtain a melt. The melt was subsequently guided to a cylindrical single layer extrusion die 140 having a diameter of 100 mm and a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the tip of the die is 1 m.
/ Min. Further, there, air is blown in from the air introduction path 150 to expand and expand, and the take-up speed is 5 m / mi.
While forming while taking up with n, the tubular film was continuously cut in the vertical direction toward the longitudinal direction at every 230 mm to obtain a belt. The extrusion molding ratio at this time was 1.6. As a result, the final shape and dimensions were 160 mm in diameter, 150 μm in thickness, and 230 mm in belt width, and an intermediate transfer belt 190 was obtained. This is referred to as an intermediate transfer belt (2).

The use of a twin-screw extruder as a belt molding machine reduced the number of steps and improved the productivity. The central value of the measured resistance value of the intermediate transfer belt (2) is 9.0 × 10
⁸ Ω. Also, use an electric resistance measuring device and
The intermediate transfer belt (2) is applied at four locations in the circumferential direction as shown in FIG. 7 and at two locations in the axial direction at each location for a total of eight locations to measure the variation in electrical resistance in the belt. However, since it was a belt molding machine using a twin-screw extruder, the measured resistance values at eight locations were within eight times. Further, the resistance was measured by applying 500 V, but no leak occurred. This is presumably because the dispersion effect of the fluorine-based surfactant was high, and no carbon aggregates were generated. In addition, the dispersion of the thickness measurement at the same position was as large as 150 μm ± 10 μm because the die gap was wider than the molded belt and the control of the film thickness was easy.
m.

According to the visual observation of the intermediate transfer belt (2), no foreign matters such as bumps and fish eyes and poor molding were found on the surface. The intermediate transfer belt (2) was mounted on the full-color electrophotographic apparatus shown in FIG. 1, and a full-color image was printed on 80 g / m ² paper to measure transfer efficiency.

In this embodiment, as the photosensitive drum 1, an organic photosensitive drum (OP) containing PTFE fine powder in the outermost layer is used.
C photosensitive drum). Therefore, high primary transfer efficiency was obtained. The primary transfer efficiency and the secondary transfer efficiency are each 9
6% and 94%. The cleaning method of the intermediate transfer belt is such that the cleaning charging member 7 is 1 × 10 ⁸ Ω.
The primary transfer simultaneous cleaning method using an elastic roller having the following resistance was used to continuously print 50,000 full-color images. From the beginning, there was no image density unevenness due to non-uniform belt resistance, no transfer omission due to leakage or the like even after 50,000 sheets of durability, and a good image free from cleaning failure was obtained.

Further, there was no filming of the toner on the surface, and no cracking, abrasion and abrasion occurred, and the surface properties were the same as those at the initial stage. The belt was cut after the endurance test, and the cut surface was observed with an electron microscope. In particular, when the carbon surface was subjected to SEM-XMA, fluorine atoms were detected. It was confirmed that there was.

Example 3 Polypropylene resin (MI = 20) 80 parts by weight Barium sulfate 20 parts by weight γ-aminopropyltriethoxysilane 1.0 part by weight Lithium perchlorate 0.5 part by weight After mixing barium sulfate and γ-aminopropyltriethoxysilane with a Henschel mixer, the polypropylene resin and lithium perchlorate were further added and mixed, and the mixture was kneaded with a biaxial extrusion kneader, and the mixture was further mixed to a thickness of 2 to 3 mm. A kneaded product having a particle size was obtained, and a molding raw material (2) was obtained.

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
By adjusting and extruding in the range of 80-200 ° C,
It was a melt. Since the melt had a low melt viscosity, a method was used in which the thickness of the formed belt was made thinner than the die gap of the annular die by setting the extrusion ratio to 1 or less and increasing the take-up speed.

The die was guided to a cylindrical single-layer extrusion die 140 having a diameter of 200 mm and a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min. Further, the tubular film is continuously reduced in the direction perpendicular to the longitudinal direction at every 230 mm while forming while reducing the diameter of the dies without blowing air from the air introduction path 150 and taking it at a take-up speed of 10 m / min. Into a belt. The extrusion molding ratio at this time was 0.8. As a result, the final shape and dimensions were 160 mm in diameter, 150 μm in thickness, and belt width 2
The intermediate transfer belt 190 was obtained. This is referred to as an intermediate transfer belt (3).

The central value of the measured resistance value of the intermediate transfer belt (3) was 2.0 × 10 ⁸ Ω. Using an electric resistance measuring device, the belt (3) was measured at four locations in the circumferential direction and two locations in the axial direction at each location by applying 100 V, as shown in FIG. The variation in the electrical resistance was measured, and the measured resistance values at eight locations were within 10 times. In addition, the dispersion of the thickness measurement at the same position was 150 μm ± 10 μm because the die gap was wider than the formed belt and the control of the film thickness was easy.
Was in the range.

According to the visual observation of the intermediate transfer belt (3), no foreign matters such as bumps and fish eyes and defective molding were found on the surface. This is presumably because barium sulfate aggregates did not occur because the silane coupling agent had a high dispersing effect. The intermediate transfer belt (3) was mounted on the full-color electrophotographic apparatus shown in FIG.
m ² was printed a full-color image on paper were measured transfer efficiency.

In this embodiment, as the photosensitive drum 1, an organic photosensitive drum (OP) containing PTFE fine powder in the outermost layer is used.
C photosensitive drum). Therefore, high primary transfer efficiency was obtained. The primary transfer efficiency and the secondary transfer efficiency are each 9
6% and 94%.

The cleaning method for the intermediate transfer belt is a primary transfer simultaneous cleaning method using an elastic roller having a resistance of 1 × 10 ⁸ Ω for the cleaning charging member 7 to continuously print 50,000 full-color images. went. From the beginning, there was no unevenness in image density due to uneven resistance of the belt, no peeling of barium sulfate was observed even after 50,000 sheets of durability, no deterioration in surface properties, no filming of toner, and the same as the initial stage. Surface properties remained. The belt was cut after the endurance test, and the cut surface was observed with an electron microscope.
, Silicon atoms were detected, and it was confirmed that the surface of barium sulfate had been treated with a silane coupling agent.

Example 4 100 parts by weight of a polypropylene resin (MI = 25) Conductive carbon black 17.0 parts by weight 1.0 part by weight of isopropyl triisostearoyl titanate 1.0 part by weight of the above composition, conductive carbon black and isopropyl tri Isostearoyl titanate was charged into 800 parts by weight of methyl ethyl ketone and mixed with a Henschel mixer. This was placed in an oven at 100 ° C. to remove methyl ethyl ketone, and the surface of the conductive carbon black was treated with a titanate coupling agent. A polypropylene resin was added to the mixture, and the mixture was further kneaded with a biaxial extrusion kneader to obtain a kneaded product having a particle size of 2 to 3 mm, thereby obtaining a molding material (3).

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
By adjusting and extruding in the range of 80-200 ° C,
It was a melt. Since the melt had a low melt viscosity, a method was used in which the extrusion molding ratio was set to 1 or less and the take-up speed was continued to reduce the thickness of the formed belt from the die gap of the annular die.

The die was guided to a cylindrical single-layer extrusion die 140 having a diameter of 200 mm and a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min. Further, the melt was reduced from the diameter of the die without blowing air from the air introduction path 150, and was formed while being drawn at a drawing speed of 10 m / min. , A tubular film was continuously cut in the direction perpendicular to the longitudinal direction at every 230 mm to form a belt. The extrusion molding ratio at this time was 0.8. As a result, the final shape and dimensions were 160 mm in diameter, 150 μm in thickness, and belt width 23.
0 mm, and an intermediate transfer belt 190 was obtained. This is referred to as an intermediate transfer belt (4).

The central value of the measured resistance value of the intermediate transfer belt (4) was 6.0 × 10 ⁹ Ω. Further, the intermediate transfer belt (4) is applied by applying 100 V using an electric resistance measuring device.
As shown in FIG. 7, the measurement was carried out at four locations in the circumferential direction and two locations in the axial direction at each location, for a total of eight locations, and the variation in the electrical resistance in the belt was measured. It was within 10 times. Further, the resistance was measured by applying 500 V, but no leak occurred. This is presumably because the dispersion effect of the titanate-based coupling agent was high, and no carbon aggregates were generated. or,
The variation in the thickness measurement at the same position was in the range of 150 μm ± 10 μm because the die gap was wider than the formed belt and the control of the film thickness was easy.

According to the visual observation of the intermediate transfer belt (4), no foreign matters such as bumps and fish eyes and defective molding were found on the surface. The intermediate transfer belt (4) was mounted on the full-color electrophotographic apparatus shown in FIG. 1, and a full-color image was printed on 80 g / m ² paper to measure transfer efficiency.

In this embodiment, as the photosensitive drum 1, an organic photosensitive drum (OP) containing PTFE fine powder in the outermost layer is used.
C photosensitive drum). Therefore, high primary transfer efficiency was obtained. The primary transfer efficiency and the secondary transfer efficiency are each 9
6% and 94%.

The cleaning method for the intermediate transfer belt is a primary transfer simultaneous cleaning method using an elastic roller having a resistance of 1 × 10 ⁸ Ω for the cleaning charging member 7, and is capable of continuously printing 50,000 full-color images. went. From the beginning, there was no image density unevenness due to uneven resistance of the belt, and after 50,000-sheet running, there was no toner filming on the surface, and the surface properties remained the same as at the beginning. The belt was cut after the endurance test, and the cut surface was observed with an electron microscope.
, A titanium atom was detected, and it was confirmed that the carbon surface was treated with a titanate coupling agent.

Example 5 100 parts by weight of a polypropylene resin (MI = 2) 15.5 parts by weight of a conductive carbon black 1.0 part by weight of acetoalkoxyaluminum diisopropylate After mixing the alkoxyaluminum diisopropylate with a Henschel mixer, adding a polypropylene resin and further mixing the resulting mixture, the mixture is kneaded with a twin-screw extruder, which is further kneaded with a particle diameter of 2 to 3 mm. (4) was obtained.

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
A melt was obtained by extruding after adjusting to a range of 80 to 200 ° C. The melt is subsequently 200 mm in diameter,
It was guided to a cylindrical single layer extrusion die 140 having a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min. Further, the tubular film is continuously expanded in the direction perpendicular to the longitudinal direction every 310 mm while forming while expanding by blowing air from the air introduction path 150 and taking it at a take-up speed of 4.5 m / min. The belt was obtained by cutting. The extrusion molding ratio at this time was 1.55. As a result, the final shape and dimensions were 355 mm in diameter, 150 μm in thickness, and 310 in belt width.
mm, and a transfer belt 190 was obtained. This is referred to as a transfer belt (1).

The center value of the measured resistance value of the transfer belt (1) was 6.0 × 10 ¹⁰ Ω. Further, by applying an electric resistance of 100 V using an electric resistance measuring device, the transfer belt (1) was moved to the position shown in FIG.
As shown in the figure, the electrical resistance variation in the belt was measured by measuring eight places, four places in the circumferential direction and two places in the axial direction at each position. It was in. Further, the resistance was measured by applying 500 V, but no leak occurred. This is presumably because the aluminum-based coupling agent had a high dispersing effect and no carbon aggregates were generated. The variation in the thickness measurement at the same position was in the range of 150 μm ± 10 μm because the die gap was wider than the formed belt and the control of the film thickness was easy.

According to the visual observation of the transfer belt (1), no foreign matters such as bumps and fish eyes and defective molding were found on the surface. The transfer belt (1) was mounted on the full-color electrophotographic apparatus shown in FIG. 2, and 50,000 full-color images were continuously printed on 80 g / m ² paper. From the beginning, there was no image density unevenness due to non-uniform belt resistance, no transfer omission due to leakage etc. even after 50,000 sheets of durability,
In addition, a good image without cleaning failure could be obtained. Further, there was no toner filming on the surface, and no cracking, abrasion and abrasion occurred, and the surface properties were the same as those at the initial stage.

Further, this belt was cut after the endurance test, and
The cut surface was observed with an electron microscope, and when SEM-XMA was applied to the carbon surface in particular, aluminum atoms were detected. Thus, it was confirmed that the carbon surface was treated with an aluminum-based coupling agent.

Comparative Example 1 100 parts by weight of a polypropylene resin (MI = 2) 17.5 parts by weight of a conductive carbon black The above composition was kneaded and dispersed by a twin-screw extruder to obtain a uniform kneaded product and molding. Material (5) was obtained.

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
A melt was obtained by extruding after adjusting to a range of 80 to 200 ° C. The melt is subsequently 160 mm in diameter,
It was guided to a cylindrical single layer extrusion die 140 having a die gap width of 150 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min. Next, the tubular film was continuously cut in the direction perpendicular to the longitudinal direction at intervals of 230 mm while forming at a take-up speed of 1 m / min while forming, thereby forming a belt. The extrusion molding ratio at this time was 1.0. As a result, a diameter of 16
0mm, thickness 150μm, belt width 230mm,
An intermediate transfer belt 190 was obtained. This is referred to as an intermediate transfer belt (5).

The center value of the measured resistance value of the intermediate transfer belt (5) was 4.0 × 10 ⁷ Ω. A voltage of 100 V was applied using an electric resistance measuring device, and the intermediate transfer belt (5) was measured at four locations in the circumferential direction and two locations in the axial direction at each location as shown in FIG. The variation of the electrical resistance in the belt was measured, and the resistance measured at eight locations was 900 times. This is because the dispersion and diffusion of carbon black were non-uniform, and the die gap was the same as the belt in which the variation in thickness measurement at the same position as the resistance measurement value at eight positions was formed. It is considered that the film thickness was in the range of 150 μm ± 50 μm.

Further, the resistance was measured by applying a voltage of 500 V. As a result, a leak occurred due to lumps. Observation of the cross-section of the bumps of the intermediate transfer belt (5) revealed carbon aggregates. The intermediate transfer belt (5) was mounted on the full-color electrophotographic apparatus shown in FIG.
m. A full-color image was printed on paper and the transfer efficiency was measured. The measured resistance variation was large, the maximum part of the transfer efficiency was 90%, and the minimum was 80%, and the transfer efficiency was not sufficient for an image having transfer unevenness.

Further, the toner was not sufficiently transferred to the bumps, and white spots occurred in the bumps. The durability test was not performed because the initial image was not good.

Further, the belt was cut, and the cut surface was observed with an electron microscope.
When multiplied by A, atoms other than carbon were not detected.

Comparative Example 2 Polypropylene resin (MI = 2) 80 parts by weight Barium sulfate 20 parts by weight Lithium perchlorate 0.5 part by weight The above composition was kneaded and dispersed by a twin-screw extruder to obtain a uniform mixture. A wrought product was obtained and used as a molding material (6).

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
A melt was obtained by extruding after adjusting to a range of 80 to 200 ° C. The melt is subsequently 160 mm in diameter,
It was guided to a cylindrical single layer extrusion die 140 having a die gap width of 150 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min.

Next, while forming at a take-up speed of 1 m / min while forming, the tubular film was continuously cut in the direction perpendicular to the longitudinal direction every 230 mm to form a belt. The extrusion molding ratio at this time was 1.0. As a result, the final shape and dimensions were 160 mm in diameter, 150 μm in thickness, and belt width 23.
0 mm, and an intermediate transfer belt was obtained. This is referred to as an intermediate transfer belt (6).

The center value of the measured resistance value of the intermediate transfer belt (6) was 7.0 × 10 ⁸ Ω. A voltage of 100 V was applied using an electric resistance measuring device, and the intermediate transfer belt (6) was measured at four locations in the circumferential direction and two locations in the axial direction at each location as shown in FIG. 7, for a total of eight locations. The variation of the electrical resistance in the belt was measured, and the measured resistance value at eight locations was within 10 times.

According to the visual observation of the intermediate transfer belt (6), bumps were generated on the surface. When the cross section of the bumps was observed, barium sulfate aggregates were observed. The intermediate transfer belt (6) was mounted on the full-color electrophotographic apparatus shown in FIG. 1, and a full-color image was printed on 80 g / m ² paper. From the beginning, there was no image density unevenness due to the non-uniform resistance of the belt.

Further, when continuous printing of 50,000 full-color images was performed, peeling of barium sulfate began to be observed after about 30,000-sheet running, and surface roughness was generated. When filming occurred and durability was further continued, filming deteriorated. For this reason,
It became a belt with no durability.

The belt was cut, and the cut surface was observed with an electron microscope.
When M-XMA was applied, atoms other than those used for barium sulfate were not detected.

Comparative Example 3 100 parts by weight of a polypropylene resin (MI = 2) 15.5 parts by weight of a conductive carbon black The above components were mixed with a Henschel mixer, and then kneaded with a twin-screw extruder. Was made into a kneaded product having a particle size of 2 to 3 mm to obtain a molding raw material (7).

Next, the single-screw extruder 100 shown in FIG.
The kneaded material is put into the hopper 120 of
A melt was obtained by extruding after adjusting to a range of 80 to 200 ° C. The melt is subsequently 200 mm in diameter,
It was guided to a cylindrical single layer extrusion die 140 having a die gap width of 1200 μm. At this time, the discharge speed of the melt discharged from the tip of the die was 1 m / min. Further, the tubular film is continuously expanded in the direction perpendicular to the longitudinal direction every 310 mm while forming while expanding by blowing air from the air introduction path 150 and taking it at a take-up speed of 4.5 m / min. The belt was obtained by cutting. The extrusion molding ratio at this time was 1.55. As a result, the final shape and dimensions were 355 mm in diameter, 150 μm in thickness, and 310 in belt width.
mm, and a transfer belt 190 was obtained. This is referred to as a transfer belt (2).

The central value of the measured resistance value of the transfer belt (2) was 8.5 × 10 ¹⁰ Ω. Further, a voltage of 100 V was applied using an electric resistance measuring device, and the transfer belt (2) was moved to the position shown in FIG.
As shown in the figure, the variation of the electric resistance in the belt was measured by measuring eight places, four places in the circumferential direction and two places in the axial direction at each position. there were. This is probably because the dispersion and diffusion of the carbon black were non-uniform. Further, when the resistance was measured by applying 500 V, a leak was caused due to lumps. Observation of the cross section of the bumps of the transfer belt (2) revealed carbon aggregates. The variation in the thickness measurement at the same positions as the resistance measurement values at the eight locations was in the range of 150 μm ± 10 μm because the die gap was wider than the formed belt and the thickness control was easy.

The transfer belt (2) was mounted on the full-color electrophotographic apparatus shown in FIG. 2, and a full-color image was printed on 80 g / m ² paper to measure transfer efficiency. The measured resistance variation was large, the maximum portion of the transfer efficiency was 92%, and the minimum was 85%, and the transfer efficiency was not sufficient for an image having uneven transfer.

Further, the toner was not sufficiently transferred to the bumps, and white spots occurred in the bumps. The durability test was not performed because the initial image was not good.

Further, this belt was cut, and the cut surface was observed with an electron microscope.
When XMA was applied, atoms other than carbon were not detected.

[0136]

As is apparent from the above description, according to the present invention, in the intermediate transfer body and the transfer member containing a filler in the material, the filler is subjected to a surface treatment to cause poor dispersion of the filler. An intermediate transfer member and a transfer member free from uneven resistance, image failure and leaks can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a color image forming apparatus.

FIG. 2 is a longitudinal sectional view of the color image forming apparatus.

FIG. 3 is a configuration diagram of a molding device.

FIG. 4 is a partial perspective view of an intermediate transfer belt having a two-layer structure.

FIG. 5 is a partial perspective view of an intermediate transfer belt having a three-layer configuration.

FIG. 6 is a perspective view of an intermediate transfer belt having a three-layer structure.

FIG. 7 is a perspective view showing a portion where an electric resistance of the intermediate transfer belt is measured.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum (first image carrier) 3 image exposure means 10 transfer device 20 intermediate transfer drum (intermediate transfer member) 62 primary transfer roller 63 secondary transfer roller 100 extruder 110 extruder 140 annular die 190 intermediate transfer drum (Intermediate transfer member)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 16 B29K 105: 16 483: 00 483: 00 505: 00 505: 00 B29L 29:00 B29L 29: 00 (72) Inventor Akira Shimada Inside Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo (72) Inventor Akihiko Nakazawa Inside Canon Inc. 3- 30-2 Shimomaruko 3-chome, Ota-ku, Tokyo (72) Inventor Takashi Kusaba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hidekazu Matsuda 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo F-term (reference) 2H032 AA05 AA15 BA09 BA18 BA23 4F210 AA11 AB11 AB28 AG08 QA01 QA03 QC02 QG04 QK01 QW21

Claims (24)

[Claims] An intermediate transfer member used in an image forming apparatus for transferring an image formed on a first image carrier onto an intermediate transfer member and further transferring the image onto a second image carrier. A transfer member used in a transfer device for electrostatically transferring a toner image formed on a first image carrier to a second image carrier, wherein the intermediate transfer member and the transfer member are made of a material An intermediate transfer member and a transfer member, characterized in that the intermediate transfer member contains a filler therein, and the filler is subjected to a surface treatment. 2. An intermediate transfer member and a transfer member according to claim 1, wherein said filler is surface-treated by a surface treatment agent containing at least one of silicon, fluorine, titanium and aluminum elements. . 3. The intermediate transfer member and transfer member according to claim 2, wherein the surface treatment agent is a silicone oil. 4. The intermediate transfer member and transfer member according to claim 2, wherein said surface treatment agent is a fluorine-based surfactant. 5. The intermediate transfer member and transfer member according to claim 2, wherein the surface treatment agent is a coupling agent. 6. The intermediate transfer member and the transfer member according to claim 5, wherein the coupling agent is a silane coupling agent. 7. The intermediate transfer body and the transfer member according to claim 5, wherein the coupling agent is a titanate coupling agent. 8. The intermediate transfer member and transfer member according to claim 5, wherein the coupling agent is an aluminum-based coupling agent. 9. The intermediate transfer member and transfer member according to claim 1, wherein the filler is conductive. 10. The intermediate transfer member and transfer member according to claim 9, wherein the conductive filler is carbon black. 11. A method for manufacturing an intermediate transfer body and a transfer member, wherein the intermediate transfer body or the transfer member is a seamless belt extruded with an annular die. 12. From a die gap of the annular die,
12. The method for manufacturing an inter-image transfer member and a transfer member according to claim 11, wherein the formed belt has a smaller thickness. 13. The intermediary transfer member according to claim 11, wherein the film take-up speed is higher than the discharge speed of the tubular molten material discharged from the tip of the annular die by extrusion of an extruder. A method for manufacturing a transfer member. 14. The extrusion molding ratio of the tube discharged from the tip of the annular die by extrusion of an extruder is 0.5 to 4.0.
A method for producing the intermediate transfer member and the transfer member according to the above. 15. A molding method for continuously molding while expanding a tube by blowing a gas having a pressure higher than the atmospheric pressure into a tubular molten material discharged from a tip of the annular die by extrusion of an extruder. The method for manufacturing an intermediate transfer member and a transfer member according to claim 11, wherein: 16. The method according to claim 11, wherein the extruder for extruding the tubular melt is a twin-screw extruder. 17. A belt formed by continuously cutting a tubular film discharged from an end of said annular die by extrusion of an extruder in a vertical direction toward a longitudinal direction. A method for producing the intermediate transfer member and the transfer member according to the above. 18. A volume resistor of the intermediate transfer member or the transfer member.
Anti 10⁰ Ω-10 ¹⁴Ω.
2. The intermediate transfer member and the transfer member according to 1. 19. A surface resistance of the intermediate transfer member or the transfer member.
Anti 10⁰ Ω-10 ¹⁷Ω.
2. The intermediate transfer member and the transfer member according to 1. 20. The intermediate transfer member and transfer member according to claim 11, wherein the maximum value of the volume resistance in the circumferential direction of the belt is within 100 times the minimum value. 21. The intermediate transfer member and transfer member according to claim 11, wherein the maximum value of the surface resistance in the circumferential direction of the belt is within 100 times the minimum value. 22. The intermediate transfer member and transfer member according to claim 11, wherein the maximum value of the volume resistance in the longitudinal direction of the belt is within 100 times the minimum value. 23. The intermediate transfer member and transfer member according to claim 11, wherein the maximum value of the surface resistance in the longitudinal direction of the belt is within 100 times the minimum value. 24. An image forming apparatus or an image forming apparatus for transferring an image formed on a first image carrier onto an intermediate transfer member and further transferring the image onto a second image carrier. In an image forming apparatus for electrostatically transferring the formed toner image to a second image carrier, a filler is contained in a material constituting the intermediate transfer body and the transfer member, and the filler is subjected to a surface treatment. And an image forming apparatus.