JP2002196590A - Endless belt, belt for image forming device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt which does not distort an output image because a toner, paper dust, etc., are less liable to stick to the surface and can be easily and inexpensively produced without affecting physical properties and characteristics. SOLUTION: The endless belt is made of a synthetic resin surface-treated with an alkylsilazane. A belt for an image forming device using the endless belt and an image forming device using the belt for an image forming device are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless endless belt having good surface slipperiness and free from image disturbance due to adhesion of toner or paper powder in an image forming apparatus. And a belt for an image forming apparatus such as an intermediate transfer belt, a transfer belt and a photoreceptor belt used in an electrophotographic copying machine, a laser beam printer, a facsimile machine and the like, and an image forming apparatus including the belt for the image forming apparatus. .

[0002]

2. Description of the Related Art Conventionally, as an endless belt such as an intermediate transfer belt of an image forming apparatus, an organic antistatic agent or a conductive filler is kneaded into a synthetic resin to form a conductive synthetic resin. The belt is used.

FIG. 1 is a schematic diagram showing an intermediate transfer device using an intermediate transfer belt. The surface of the photosensitive drum 1 is uniformly charged by the charger 3, and an electrostatic latent image corresponding to the image is formed by the exposure device 2. This electrostatic latent image is developed by the developing device 5 to become a toner image. The toner image is transferred to the intermediate transfer belt 6 by the electrostatic transfer device 10. Intermediate transfer belt 6
The upper toner image is transferred to the recording paper 11 by the pressing roller 12. Residual toner on the photosensitive drum is cleaner 4
To prepare for the next charging cycle.

[0004] An intermediate transfer belt 6 composed of an endless belt is supported by a plurality of rollers 7, 8, 9 in contact with the inner surface thereof, and is used for transferring a toner image and conveying a recording sheet. At least one of the plurality of rollers is a driving roller connected to a driving source such as a motor, and the other is a driven roller that rotates freely as the endless belt moves. The toner adhered to the intermediate transfer belt 6 is usually scraped off by a cleaning blade 13 made of urethane.

A conventional endless belt formed by kneading an organic antistatic agent and a conductive filler into a synthetic resin to form a conductive synthetic resin, and molding and processing the same into a belt shape,
For example, when used as an intermediate transfer belt of an image forming apparatus, toner, paper powder, and the like adhere to the surface after long-term continuous use. If toner or paper dust adheres to the endless belt in this way, the output image may be disturbed.Therefore, the toner is removed with a cleaning blade. Was a problem.

In order to solve this problem, an endless belt mainly composed of a fluorine resin having a small surface energy such as ethylene / tetrafluoroethylene copolymer (ETFE) or polyvinylidene fluoride (PVdF) has been formed.
Forming the outermost layer of a composition with low surface energy on the surface as a multilayer structure by co-extrusion or dip coating, or performing surface treatment or surface coating with a silane coupling agent or alkyl silanol, etc. A device has been devised to make it difficult for paper powder to adhere.

[0007]

However, in the case of a belt composed of a single layer containing a fluororesin as a main component, the fluororesin generally has a low elastic modulus, so that the belt is easily stretched, and the fluororesin is generally expensive. Therefore, the cost of the belt also increases.

In the case of a multilayer belt, the outermost layer is
If the thickness is more than μm, the insulating layer cannot exhibit the characteristics of a conductive belt.If the outermost layer is also a conductive layer, the inner and outer layers must be adjusted to the specified resistance. Not without technical difficulties.

Although a method of surface treatment or surface coating with a silane coupling agent or an alkylsilanol is effective, it is generally necessary to go through a heat treatment step at 80 ° C. or higher, and this heat treatment causes the resistance of the endless belt to decrease. Since there is a possibility of causing a change, a change in physical properties, a change in dimensions, or the like, there is a problem that processing conditions are limited.

[0010] An endless belt which solves the above-mentioned conventional problems and does not easily disperse an output image by preventing toner or paper dust from adhering to the surface, and is easy and inexpensive without affecting physical properties and characteristics. Endless belts that can be manufactured
It is an object of the present invention to provide an image forming apparatus belt and an image forming apparatus using the endless belt.

[0011]

The endless belt of the present invention is characterized in that the endless belt is made of a synthetic resin and is surface-treated with alkylsilazane.

That is, as a result of the inventor's intensive studies for the above purpose, the surface treatment of an endless belt made of synthetic resin with alkylsilazane improves the slipperiness of the surface,
The present inventors have found that image disorder due to adhesion of toner, paper dust, and the like in an image forming apparatus is suppressed, and arrived at the present invention.

Alkylsilazanes are very reactive and can form bonds with most of the functional groups, so that good surface treatment can be performed on any synthetic resin substrate.

For example, an ester resin such as polycarbonate, polybutylene terephthalate, or polyethylene terephthalate reacts with a hydroxyl group terminal, a carboxylic acid terminal, or an ester portion and reacts with a polyolefin having a low reactivity such as polypropylene. Forms a bond to a secondary carbon.

[0015] Even a fluororesin such as ethylene / tetrafluoroethylene copolymer exists on the surface of carbon black if a filler such as carbon black is blended to impart conductivity. Since it forms a bond with a hydroxyl group terminal or a carboxylic acid terminal, it can be used practically without any restriction on the material of the endless belt.

Further, in the case of a fluororesin coating or the like, a problem may occur that the adhesion between the surface layer and the substrate is weak.
Alkylsilazane quickly forms the above-mentioned chemical bond with the synthetic resin base material, and therefore is excellent in that it is firmly adhered.

Further, in the case of a fluorine resin coat or the like, the thickness is 1 μm.
m, it is difficult to form a thin film with a uniform thickness.
When a film thickness of about 0 μm or more is formed, an insulating layer is formed on the surface of the endless belt, so that it cannot function as a conductive endless belt. Since it does not have a substantial thickness only by introducing a functional group into the endless belt, it can be used without affecting the conductivity of the endless belt.

Further, unlike the silane coupling agent and the alkylsilanol, the alkylsilazane does not require a high temperature and quickly forms a bond at room temperature, so that the surface treatment does not cause deformation or deterioration of the substrate.

The alkylsilazane used in the present invention preferably has a functional group represented by the following structural formula, particularly a functional group having a fluoroalkyl group.

[0020]

Embedded image

The endless belt of the present invention has a surface resistivity of 1 to 1 × 10 ¹⁶ Ω, and in one endless belt, the maximum value of the resistivity is the minimum value of 10 × 10 ¹⁶ Ω.
It is preferably 0 times or less.

The belt for an image forming apparatus of the present invention is an intermediate transfer belt, a transfer belt or a photosensitive belt made of the endless belt.

The image forming apparatus of the present invention has the belt for the image forming apparatus.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

(Base Resin for Endless Belt) The synthetic resin material constituting the base of the endless belt of the present invention is not particularly limited. The one obtained by adjusting is most preferably used in the image forming apparatus.

As the synthetic resin, either a thermoplastic resin or a thermosetting resin can be used.

This is due to the high reactivity of the alkylsilazane. For example, if polyester or polyamide is the base resin, the hydroxyl group, carboxylic acid residue or amino group of the resin reacts with the alkylsilazane. Form a chemical bond. In addition, even with polypropylene or the like which is generally considered to have poor reactivity, alkylsilazane forms a chemical bond. This is considered to be because nitrogen is eliminated from tertiary carbon to generate a reaction active site. In addition, when carbon black is blended to develop conductivity, the surface functional group of carbon black present on the belt surface may react with the alkylsilazane, and therefore any synthetic resin may be used. Applicable.

As the thermoplastic resin, polypropylene, polyethylene (high density, medium density, low density, linear low density), propylene ethylene block or random copolymer, rubber or latex component, for example, ethylene / propylene copolymer rubber , Styrene-butadiene rubber, styrene-butadiene-styrene-styrene block copolymer or a hydrogenated derivative thereof, polybutadiene, polyisobutylene, polyamide, polyamideimide, polyacetal, polyarylate, polycarbonate, polyimide,
Liquid crystalline polyester, polysulfone, polyphenylene sulfide, polybisamide triazole, polyetherimide, polyetheretherketone, acrylic,
Polyfluorinated vinylidene, polyvinyl fluoride, chlorotrifluoroethylene, ethylene tetrafluoroethylene copolymer, hexafluoropropylene, perfluoroalkyl vinyl ether copolymer, alkyl acrylate copolymer, polyester ester copolymer, poly An ether ester copolymer, a polyether amide copolymer, a polyurethane copolymer or the like or a mixture thereof can be used.

As the thermosetting resin, for example, one composed of one kind of epoxy resin, melamine resin, phenol resin, unsaturated polyester resin and the like, or a mixture thereof can be used.

One of these resins may be used alone, or two or more of them may be used in combination. As the thermoplastic resin, it is preferable to use a crystalline resin and an amorphous resin in combination. In this case, as the crystalline resin, PAT (polyalkylene terephthalate) is preferable.
T (polybutylene terephthalate), PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) are more preferable. As the amorphous resin, PC
Polyesters such as (polycarbonate) and PAr (polyarylate) and resins having an ester bond in a side chain such as PMMA (polymethyl methacrylate) are preferable. Among them, polyester is preferable, and PC can be particularly preferably used.

The weight ratio between the crystalline resin and the amorphous resin is not particularly limited, but generally, the crystalline resin has excellent chemical resistance and bending resistance, and the amorphous resin has good molding dimensional stability. Because it is excellent, the weight ratio of crystalline resin / amorphous resin is from 1/99 to 99/1, preferably from 40/60 to 9 depending on the purpose of use.
7/3, more preferably 60/40 to 95/5, particularly preferably 70/30 to 90/10.

(Conductive Filler) In the present invention, when it is necessary to adjust the electric resistance value, a conductive filler may be added. In particular, in a seamless belt or the like used in an image forming apparatus, it is necessary to adjust the surface resistivity and the volume specific resistivity according to the application in order to electrically attract and transfer toner and paper.

The conductive filler to be compounded is not particularly limited as long as it satisfies the performance required for the application.
Various types can be used, and specifically, carbon-based fillers such as carbon black, carbon fiber, and graphite, metal-based conductive fillers, and metal-oxide-based conductive fillers are used.

A particularly preferred conductive filler is carbon black which is excellent in dispersibility.

(Carbon Black) It is preferable to mix the following carbon black as a conductive filler in the base resin of the endless belt of the present invention in order to exhibit conductivity.

There are no particular restrictions on the type of carbon black used in the present invention. For example, channel black, acetylene black,
Furnace black and the like can be mentioned, and one of these can be used alone or as a mixture of two or more.

Specific surface area of carbon black The carbon black used in the present invention is intended to exhibit conductivity.
Is what you do. Generally, carbon black has a specific surface area
Is larger, the powder resistance is lower and the conductivity is easier to develop.
It is said that it is conductive by adding a small amount of carbon black
It is preferable that the specific surface area is large in order to express the property. Ingredient
Physically 10m as measured by BET method ²/ G or better
Best, 50m²/ G or more is more preferable.

On the other hand, if the specific surface area is too large, poor dispersion of carbon black in the resin will occur, or the contact area with the resin per unit weight of carbon black will increase, resulting from the catalytic action of carbon black. There is a problem that a decomposition reaction of the resin occurs. For this reason,
The specific surface area is preferably 1000 m ² / g or less, and 500 m ² / g or less.
It is particularly preferred that it is not more than ² / g.

The specific surface area is, in particular, 80 to 400 m ² /
g is preferable.

Particle Size of Carbon Black The particle size of carbon black is not particularly limited. Generally, carbon black having a small particle size has a large specific surface area, high conductivity, and is liable to cause a decomposition reaction of a resin. The range in which the blending effect can be most effectively exhibited is a particle size of 15 to 40.
nm range.

The DBP oil absorption of carbon black The DBP oil absorption is not particularly limited, but the carbon black used in the present invention is intended to exhibit conductivity.
Generally, it is said that the larger the DBP oil absorption, the lower the powder resistance and the higher the conductivity of carbon black. Therefore, the larger the DBP oil absorption, the more preferable it is to exhibit conductivity by adding a small amount of carbon black. . Specifically, J
The measured value according to IS K6221 is preferably 35 ml / 100 g or more, more preferably 45 ml / 100 g or more.

Further, carbon black having an excessively large DBP oil absorption may empirically cause poor dispersion in the resin.
00ml / 100g or less, preferably 300ml / 10
0 g or less, more preferably 200 ml / 100 g
g or less is particularly preferable.

The blending amount of carbon black The appropriate blending amount of carbon black varies depending on the conductivity of carbon black, the desired level, and the production conditions, and cannot be unconditionally specified. However, if the blending amount is too small, the conductivity is sufficient. Therefore, the content in the resin composition constituting the endless belt is preferably 3% by weight or more, more preferably 10% by weight or more. If the amount is too large, the mechanical properties of the resin composition may be reduced. Therefore, it is preferable that the amount is small to some extent, specifically, 30% by weight or less, and 20% by weight.
It is more preferable that the following is satisfied.

(Additional Component; Optional Component) The base resin of the endless belt of the present invention may contain, in addition to carbon black, any additional component according to various purposes.

Specifically, as various fillers, for example, calcium carbonate (heavy and light), talc, mica, silica, alumina, aluminum hydroxide, zeolite, wollastonite, diatomaceous earth, glass fiber, glass beads, Bentonite, asbestos, hollow glass beads, graphite,
Fillers such as molybdenum disulfide, titanium oxide, carbonate fiber, aluminum fiber, styrene steel fiber, brass fiber, aluminum powder, wood powder, rice hull, graphite, metal powder, conductive metal oxides, organometallic compounds, and organic metal salts And other additives such as antioxidants (phenolic,
Sulfur-based, phosphate-based, etc.), lubricants, various organic and inorganic pigments, UV inhibitors, antistatic agents, dispersants, neutralizers, foaming agents, plasticizers, copper damage inhibitors, flame retardants, cross-linking agents And various additives such as a crosslinking aid, a flow improver, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antifogging agent, an antiblocking agent, a slip agent, and a coloring agent.

(Method of Melt Kneading and Molding) The resin composition containing the base resin, carbon black and optional components to be blended as necessary is prepared by a single-screw extruder, a twin-screw extruder, a multi-screw extruder, a Banbury mixer, Rolls, Brabender, Plastograph, kneaded using ordinary kneading machines such as kneaders and compounded into pellets and molded into a belt, but in special cases, each component is directly supplied to the molding machine, It is also possible to mold while kneading the compounding components with a molding machine.

The method of forming the endless belt is not particularly limited, but includes injection molding for injecting a molten resin, extrusion molding for extruding the molten resin, compression molding for compressing the molten resin, and dissolving in a solvent. Rotational molding, in which a resin is adhered to the inside of a cylindrical rotating body, and molding, and casting, in which a melted resin is poured into a mold and solidified, are used. Films, sheets, and the like obtained by these methods can be joined to form a belt. Also, a seamless endless belt can be formed using any of the methods described above. Considering practical performance and productivity, an endless belt formed by melt extrusion using a mold having an annular extrusion opening is preferable.

(Surface Resistivity of Endless Belt) The endless belt used in the present invention has a surface resistivity of 1 to 10 ^16.
Ω is selected from the range.

The preferable range varies depending on the application. For example, when used as a photoreceptor belt, the surface resistivity is from 1 × 10 ¹ to 1 × 10 ⁹ Ω so that electric charges on the outer surface can be released to the inner surface as necessary. When used as an intermediate transfer belt, the surface resistivity is preferably 1 × 10 ⁶ to 1 × 10 ¹³ Ω, which facilitates charge-transfer, and when used as a transfer belt, it is easy to be charged. 1 × 10 ¹⁰ -1 × 10 ¹⁶ Ω
And a high region is preferable.

It is preferable that the distribution of the surface resistivity in one endless belt is narrow. In each of the preferable surface resistivity regions, the difference between the maximum value and the minimum value in one belt is two.
It is preferable that the value is within the order of magnitude (the maximum value is 100 times or less of the minimum value).

The surface resistivity of the endless belt can be easily measured by, for example, Hiresta and Loresta manufactured by Dia Instruments Co., Ltd. and R8340A manufactured by Advantest Co., Ltd.

(Thickness of Endless Belt) If the thickness of the endless belt is excessively large, the deformation difference between the outer side and the inner side of the belt becomes large easily when the curvature with the roller is large. Further, the toner transferred to the outer portion is deformed and scattered, so that the image is deformed. On the other hand, if the thickness of the endless belt is excessively small, cracks easily occur due to dust entering between a small roller and the belt, or scratches caused by contact with a photoconductor, and the belt is easily damaged. Therefore, the thickness of the endless belt needs to be 70 to 300 μm, and particularly preferably 100 to 200 μm.

(Alkylsilazane) In the present invention, the endless belt formed as described above is subjected to a surface treatment with alkylsilazane.

As the alkylsilazane, one having an arbitrary functional group X bonded to nitrogen represented by the following structural formula is preferable. By introducing this functional group X, it is possible to transfer toner or paper powder to an endless belt. Adhesion can be further reduced.

[0055]

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Specific examples include alkylsilazanes represented by the following structural formula.

[0057]

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Here, X includes an alkyl group and a silyl group, and R ¹ , R ² and R ³ have 1 to 3 carbon atoms.
Examples thereof include an alkyl group and an aryl group of 0, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.

As the alkylsilazane, an alkyldisilazane represented by the following structural formula is also preferably used.

[0060]

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Here, R ^{1 to} R ⁶ may be each independently substituted, and may be an alkyl group having 1 to 30 carbon atoms, an aryl group, etc., specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, A butyl group.

As the alkylsilazane, hexamethyldisilazane represented by the following structural formula is particularly preferable.

[0063]

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(Surface Treatment Method) As described above, since the alkylsilazane quickly forms a functional group on the surface of the substrate of the endless belt, the surface treatment method is not particularly limited. Generally, surface treatment is easily performed by applying a liquid obtained by diluting an alkylsilazane with a solvent such as meta-xylene hexafluoride to an endless belt by a known method such as spray coating, dip coating, bar coating, and then drying. Can be applied.

The concentration of the alkylsilazane solution to be used is not particularly limited, but is preferably 0.1 to 10% by weight, particularly preferably about 1 to 3% by weight, in view of workability of coating and the like.

Further, drying after application is only required to be left at normal temperature and normal humidity, whereby the surface of the base material and the alkylsilazane are quickly bonded. The leaving time is preferably 3 hours or more, and particularly preferably one day.

Further, after coating, depending on the application, 60-150
Although it may be heated to about ° C, this heat treatment is not particularly required.

As described above, the adhesion amount of the alkylsilazane by the surface treatment is about 0.0001 to 10 g / m ² , preferably about 0.01 per area of the surface of the endless belt.
About 1 g / m ² is good. If the adhesion amount of the alkylsilazane is small, the effect of the present invention is not sufficiently exhibited,
If the amount is too large, a residue remaining without reacting with the substrate may become a contamination source.

(Use of Endless Belt) The use of the endless belt of the present invention is not particularly limited, but it is preferably used in the field of OA equipment having strict required physical properties such as dimensional accuracy, bending resistance, and tensile elongation at break, especially for functional members. be able to. When this endless belt is made into a seamless belt shape,
This is suitable because there are few defects such as cracks and elongation.

This endless belt can be suitably used, for example, as an electrophotographic intermediate transfer belt, a transfer belt, and a photosensitive belt.

[0071]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

The materials used in the production of the endless belt in the examples and comparative examples are as follows, and the composition was as shown in Table 1.

(Carbon Black) “MA100” manufactured by Mitsubishi Chemical Corporation Specific surface area: 110 m ² / g, DBP oil absorption: 100 ml
/ 100 g, primary particle size: 24 nm (resin) ・ PC "Iupilon E200" manufactured by Mitsubishi Engineering-Plastic Corporation
0 ”・ PBT“ Novadur 504 ”manufactured by Mitsubishi Engineering-Plastic Corporation
0ZS "・ ETFE" Aflon COP C55 "manufactured by Asahi Glass Co., Ltd.
AP ”(Other components) ・ Heat stabilizer“ Clariant Japan K.K. ”PEP
Q (Surface treatment agent) ・ 1% by weight solution of perfluorohexamethyldisilazane (solvent is meta-xylene hexafluoride)

The obtained endless belt was evaluated by the following method, and the results are shown in Table 1.

(Thickness) Measured at a pitch of 20 mm in the circumferential direction of the seamless belt using a micrometer manufactured by Tokyo Seimitsu Co., Ltd.

(Surface Resistivity) The surface resistivity can be suitably measured in different regions depending on the measuring instrument. Sample having a surface resistivity of 1 to 10 ⁶ Ω: “Loresta” (trade name) manufactured by Dia Instruments Co., Ltd. Sample having a surface resistivity of 10 ⁶ to 10 ¹³ Ω: manufactured by Dia Instrument Co., Ltd. `` Hiresta '' (product name)
(Applied voltage: 500 V) Sample having a surface resistivity of 10 ¹³ to 10 ¹⁶ Ω: “R8340A” (trade name) manufactured by Advantest Co., Ltd. (Applied voltage: 500 V) Measurement time was set to 10 seconds, and one endless belt was used. The measurement was performed at a pitch of 20 mm in the circumferential direction, and the ratio of the maximum value and the minimum value to the maximum value / minimum value was obtained.

(Wetting Test) The wetting index of an endless belt and a surface-treated endless belt was measured using a wetting index standard solution manufactured by Wako Pure Chemical Industries, Ltd.

(Evaluation of Mounting of Image Forming Apparatus) The endless belt was mounted on the image forming apparatus, a standard image was continuously output, and the final image after continuous output and the degree of dirt on the endless belt were visually evaluated.

Comparative Example 1 As shown in Table 1, an endless belt was produced by blending PC / PEPQ / carbon black.

First, the mixture was kneaded into pellets using a twin-screw kneading extruder (“PCM45” manufactured by Ikegai Kihan Co., Ltd.) with the composition shown in Table 1. The obtained pellets were dried at 130 ° C. for 8 hours and had a diameter of φ180 mm. A 40 mmφ extruder with a 6 mm spiral type annular die having a lip width of 1 mm, extruded in the form of a molten tube below the annular die, and the extruded molten tube was mounted on the same axis as the annular die via a support rod via a support rod. While being in contact with the outer surface of a 170 mm cooling mandrel and cooling and solidifying, the core is installed inside the seamless belt and the rolls installed outside take it off while holding the seamless belt in a cylindrical shape. While 3
The extruded amount and the take-up speed were adjusted so as to obtain a predetermined thickness by cutting into a ring having a length of 40 mm to obtain a resin endless belt (seamless belt) having a diameter of 169 mm.

The thickness of the endless belt was targeted at 140 μm, and was adjusted to be ± 14 μm. The residence time was adjusted in the range of 5 to 20 minutes so that thermal deterioration did not become severe.

The endless belt has a surface resistivity of 10
It was about ⁸ Ω, which was a level suitable for an intermediate transfer belt. The wetting index was 39 mN / m.

This endless belt was mounted on an image forming apparatus as an intermediate transfer belt, and image evaluation was performed. As a result, a good initial image was obtained. Further, continuous image output was continued, but since the PC was weak in bending fatigue resistance, cracks occurred in the seamless belt at the time of output of about 5126 sheets, and subsequent image output was not possible. The 5000th image was so good that it could not be distinguished from the initial image. However, when the cracked belt was visually observed, dirt was slightly fixed. As a result of analyzing the stain, it was found that the toner was the main component.

Example 1 An endless belt was manufactured in the same manner as in Comparative Example 1, and a 1% by weight solution of perfluorohexamethyldisilazane was sprayed on the endless belt by spraying. m ² and left in the air-dried state for one day.

An attempt was made to measure the film thickness of the surface-treated layer of this surface-treated product using a laser measuring instrument, but the measurement was not possible because the film thickness was too thin. Effective thickness is 1μ due to the capability of the measuring instrument
m.

When the surface resistance of this endless belt was measured, it was about 10 ⁸ Ω, which was almost the same as before the surface treatment of Comparative Example 1.

The surface wetting index was measured to be 31 m
Even at N / m, the surface did not wet (ie, less than 31 mN).

This endless belt was mounted on an image forming apparatus as an intermediate transfer belt, and a good initial image was obtained when image evaluation was performed. Further, continuous image output was continued, but since the PC was weak in bending fatigue resistance, cracks occurred in the seamless belt when about 5643 sheets were output.
No further image output was possible. The 5000th image was so good that it could not be distinguished from the initial image. Further, when the cracked belt was visually observed, no contamination was confirmed.

Comparative Example 2 As shown in Table 1, an endless belt was manufactured in the same manner as in Comparative Example 1 except that the blending ratio of PC / PBT / PEPQ / carbon black was used.

The surface resistivity of this endless belt is 10
It was about ⁸ Ω, which was a level suitable for an intermediate transfer belt. The wetting index was 39 mN / m.

This endless belt was mounted on an image forming apparatus as an intermediate transfer belt, and image evaluation was performed. As a result, a good initial image was obtained. Further, when the image output was continuously performed, 50,000 sheets could be output without generating a crack unlike in Comparative Example 1 (the operation was terminated at the time of output of 50,000 sheets). The final image was slightly distorted as compared with the initial image, such as blurring in a halftone portion or the like. Visual observation of the endless belt after output revealed that contaminants had adhered.

Example 2 An endless belt was manufactured in the same manner as in Comparative Example 2, and the endless belt was subjected to a surface treatment in the same manner as in Example 1.

The surface resistivity of this endless belt is 10
^{The value was} about ⁸ Ω, which was almost equal to that before the surface treatment of Comparative Example 2.
Also, the wetting index was less than 31 mN / m.

This endless belt was mounted on an image forming apparatus as an intermediate transfer belt, and a good initial image was obtained when image evaluation was performed. Further, when the image output was continuously performed, 50,000 sheets could be output without generating a crack as in Comparative Example 2 (the output was completed at the time of output of 50,000 sheets). The final image was also good and little difference from the initial image was observed. When the endless belt after the output was visually observed, contaminants were slightly adhered, but the level was extremely small as compared with Comparative Example 2. When the attached matter was analyzed, the toner was the main component.

Comparative Example 3 An endless belt was manufactured in the same manner as in Comparative Example 1 except that the blending of PC / PBT / PEPQ / carbon black shown in Table 1 was performed.

The surface resistivity of this endless belt is 10
It was about ¹² Ω, which was a level suitable for a transfer belt.
The wetting index was 40 mN / m.

This endless belt was mounted on an image forming apparatus as a transfer belt, and image evaluation was performed. As a result, a good initial image was obtained. Further, when the image output was continuously performed, 50,000 sheets could be output without generating a crack as in Comparative Example 2 (the output was completed at the time of output of 50,000 sheets). The final image was slightly disturbed, such as blurring in a halftone portion. When the endless belt after output was visually observed, contaminants were confirmed although slightly less than in Comparative Example 2. It is presumed that the reason why the number is smaller than that of Comparative Example 2 is that the toner does not directly contact the belt surface due to the configuration in the transport transfer method.

Example 3 An endless belt was manufactured in the same manner as in Comparative Example 3, and the endless belt was subjected to a surface treatment in the same manner as in Example 1.

The surface resistivity of this endless belt is 10
^{The value was} about ¹² Ω, which was almost equal to that before the surface treatment of Comparative Example 3. Also, the wetting index was less than 31 mN / m.

This endless belt was mounted on an image forming apparatus as a transfer belt and image evaluation was performed. As a result, a good initial image was obtained. Further, when the image output was continuously performed, 50,000 sheets could be output without generating a crack as in Comparative Example 3 (the output was completed at the time of output of 50,000 sheets). The final image was also good and little difference from the initial image was observed. When the endless belt after the output was visually observed, slight contaminants were attached, but the level was extremely small as compared with Comparative Example 3. When the attached matter was analyzed, the toner was the main component.

[0101]

[Table 1]

[0102]

As is clear from the above Examples and Comparative Examples, according to the present invention, the surface treatment of the endless belt can be easily performed without impairing the physical properties and characteristics of the substrate by treating the surface with alkylsilazane. To improve adhesion of toner and paper powder. Therefore, with an image forming apparatus belt and an image forming apparatus using the endless belt of the present invention having such excellent stain resistance, a good image can be obtained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a side view of a conventional intermediate transfer device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Exposure device 3 Charger 4 Cleaner 5 Developing device 6 Intermediate transfer belt 7, 8, 9 Conveyance roller 10 Electrostatic transfer device 11 Recording paper

Continued on the front page (72) Inventor Makoto Morikoshi 1 Tohocho, Yokkaichi-shi, Mie Pref. Inside the Yokkaichi Office of Mitsubishi Chemical Corporation (72) Inventor Norihiro Otsu 1 Tohocho, Yokkaichi-shi, Mie Yokkaichi Mitsubishi Chemical Corporation In-house F-term (reference) 2H032 BA09 BA18 2H035 CA05 CB06 CF00 2H068 AA55 AA58 BA58 FA04 FA30 4F073 AA10 BA04 BA07 BA08 BA09 BA15 BA19 BA23 BA26 BA27 BA31 BA34 BB01 BB07 EA01 EA64

Claims (6)

[Claims] 1. An endless belt made of a synthetic resin, which is surface-treated with an alkylsilazane. 2. The endless belt according to claim 1, wherein said alkylsilazane has a functional group represented by the following structural formula. Embedded image 3. The method of claim 1 or 2, a surface electric resistivity of 1 to 1 × 10 ^{1 6} Omega, and 100 times the maximum value of the In the one endless belt of the resistivity minimum An endless belt characterized by the following. 4. An endless belt according to claim 1, wherein said alkylsilazane has a fluoroalkyl group. 5. A belt for an image forming apparatus, which is an intermediate transfer belt for an image forming apparatus, a transfer belt, or a photosensitive belt, comprising the endless belt according to any one of claims 1 to 4. 6. An image forming apparatus comprising the belt for an image forming apparatus according to claim 5.