JPH0531821A - Manufacture of semiconductive endless belt - Google Patents

Abstract

PURPOSE:To constitute the above method so that neither generation of positional deviation during running nor contamination of a roller are caused and the manufacturing is simple. CONSTITUTION:A heat-resistant resin pipe 3 where a groove is formed in the outer circumferential surface in a circumferential direction is arranged within a steel pipe, a beltlike body 6 made of thermoplastic resin is held in the groove 7 in the outer circumference of the resin pipe 3 and a thermoplastic sheet 1 molded into a state of an endless belt is arranged on the outer circumference of the resin pipe 3. Then at least the resin pipe 3 and thermoplastic sheet 1 are heated under that state, the thermoplastic sheet 1 and thermoplastic beltlike body 6 are softened by this heating, the resin pipe 3 is expanded, the outer circumferential surface of the beltlike body 6 made of thermoplastic resin is pressure-contacted to the inner circumferential surface of the thermoplastic sheet 1 of the outer circumferential surface of the resin pipe 3 and the beltlike body 6 made of thermoplastic resin is bonded integrally to the inner circumferential surface of the thermoplastic sheet 1 in the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a semiconductive endless belt such as an intermediate transfer belt, a photosensitive belt and a contact developing sleeve used in various OA equipment such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art An electrophotographic copying machine, particularly a full-color electrophotographic copying machine, temporarily transfers a full-color toner image formed on a photosensitive member onto an outer peripheral surface of an intermediate transfer endless belt made of a thermoplastic resin endless belt. It is designed to be re-transferred to copy paper. Such a full-color electrophotographic copying machine is usually constructed as shown in FIG. That is, the electrophotographic copying machine includes an optical device 12 that guides reflected light of a document 11, a filter 13 that separates the reflected light of the document into three primary colors of red, green, and blue, and a belt-shaped photoconductor having photoconductivity. 14, a developing device 15, and a photoconductor 14
Intermediate transfer endless belt 17 for temporarily transferring the toner image formed on the outer peripheral surface of the copy paper 16 before copying the toner image onto the copy paper 16.
And a fixing device 18. More specifically,
A charging charger 19 is provided in the vicinity of the start end side portion of the belt-shaped photoconductor 14 having photoconductivity, and three developing portions 15a to 15c are provided in the middle part of the photoconductor 14. The belt-shaped photoconductor 14 is charged by the charging charger 19 and then exposed by the reflected light of the document projected from the optical device 12, and an electrostatic latent image is formed thereon. In this case, in the projection path of the optical device 12 for projecting the reflected light of the original onto the photoconductor 14, the filter 13 for separating the reflected light of the original into the three primary colors of red, green and blue as described above.
The primary color lights separated by the above are sequentially guided to the belt-shaped photoconductor 14 in the order of, for example, red is first, and then green, and each electrostatic latent image is formed. The developing device 15 includes three developing units 15a, 15b, and 15c so as to correspond to the above-mentioned three types of primary colors, and respectively stores toners of three types of colors corresponding to the above-described separated three primary colors. .. Then, the latent image formed by the color-separated light is color-developed with the toner corresponding to the color. That is, a colored toner image is formed for each color by the toners of the above three types of colors, and this is the primary transfer roller 20.
By this action, the toner images are sequentially transferred to the outer surface of the intermediate transfer endless belt 17, and a full-color toner image is formed on the intermediate transfer endless belt 17. As described above, the copying machine sequentially transfers the colored toner image formed for each color onto the copy paper 16,
An intermediate transfer endless belt 17 that does not form a colored toner image on the copy paper 16 and does not expand or contract due to humidity or the like.
First, a colored toner image is formed. Then, the toner image is transferred onto the copy paper 16 supplied from the paper cassette 21.
Then, it is retransferred by the action of the secondary transfer roller 22. The retransferred full-color toner image is sent to the fixing device 18 as the copy paper 16 is conveyed and fixed, and the copy paper 16 on which the toner image has been fixed is sent out from the copying machine as indicated by an arrow. The toner remaining on the intermediate transfer endless belt 17 is collected by the cleaning blade 25 of the cleaning device 24 after the transfer and is ready for the next transfer. Two
3 is a conveyor belt, and 26 to 28 are rollers.

The above-mentioned intermediate transfer endless belt 17
Is by extrusion molding, polycarbonate (PC), polypropylene a dispersion of (PP) conductive material such as carbon black in thermoplastic resin such as, 10 ⁸ to 10 ¹¹ Omega
It is obtained by forming a semi-conductive endless belt-shaped (cylindrical) sheet having a size of cm. This endless belt-like sheet runs while being stretched by three rollers 26 to 28 as shown in FIG. 9, and a deviation occurs during the running. Therefore, conventionally, to prevent deviation (positional deviation) of the belt,
As shown in FIG. 8, a running guide 2 made of rubber or elastomer is provided on the inner surface of both ends of the intermediate transfer endless belt 17.
9 is fixed along the circumference with a double-sided adhesive tape 30, and the running guides 29 are fitted into guide grooves (not shown) formed at both ends of the rollers 26 to 28 to prevent deviation. It was

[0004]

However, in the method of fixing the traveling guide 29 to the belt 17 using the adhesive tape 30 as described above, since the fixing force of the adhesive tape 30 is weak, the traveling guide 29 itself is offset. However, the problem of positional deviation still occurring during traveling still remains, and the rollers 26 to 28 and the like are contaminated with the adhesive. Further, the traveling guide 29 has to be fixed while being positioned, which requires time and effort.

The present invention has been made in view of the above circumstances, and is semi-conductive endless which is easy to manufacture without causing a positional deviation during running or soiling a roller or the like with an adhesive. The purpose is to provide a belt manufacturing method.

[0006]

In order to achieve the above object, a method of manufacturing a semi-conductive endless belt according to the present invention comprises an inner cylindrical body having grooves formed circumferentially on an outer peripheral surface thereof. It is arranged in an outer cylindrical body having a thermal expansion coefficient smaller than the thermal expansion coefficient, the thermoplastic resin strip is housed in the groove of the outer periphery of the inner cylindrical body, and is formed into an endless belt shape on the outer periphery of the inner cylindrical body. In this state, at least the inner cylindrical body and the thermoplastic sheet are heated, and this heating softens the thermoplastic sheet and the thermoplastic resin strip and expands the inner cylindrical body. ,
The outer peripheral surface of the inner cylindrical body is pressed against the outer peripheral surface of the thermoplastic sheet against the inner peripheral surface of the outer cylindrical body, and the outer peripheral surface of the thermoplastic resin strip is pressed against the inner peripheral surface of the thermoplastic sheet. The thermoplastic resin strip is integrally fused in the circumferential direction on the inner peripheral surface of the.

[0007]

That is, in the method of manufacturing the semiconductive endless belt of the present invention, first, the inner cylindrical body having grooves formed on the outer peripheral surface in the circumferential direction is provided with a thermal expansion coefficient smaller than that of the inner cylindrical body. It is disposed in the outer cylindrical body having. Then, prior to the disposition of the inner cylindrical body, or after the disposing, while accommodating the thermoplastic resin strip in the outer peripheral groove of the inner cylindrical body, on the outer periphery of the inner cylindrical body, by an extrusion molding method. A thermoplastic sheet shaped like an endless belt is provided. Next, in that state, at least the inner cylindrical body and the thermoplastic sheet are heated. As a result, the thermoplastic sheet and the thermoplastic resin strip are softened, and at the same time, the inner cylindrical body is expanded, and the outer peripheral surface of the softened thermoplastic sheet is expanded by the outer cylindrical surface of the inner cylindrical body by the expansion. The inner peripheral surface of the body is pressed and the outer peripheral surface of the thermoplastic resin strip is pressed against the inner peripheral surface of the thermoplastic sheet. Therefore, at the same time that the thermoplastic resin strip is integrally fused with the thermoplastic sheet in the circumferential direction, the inner peripheral surface of the outer cylindrical body, for example, a mirror surface is transferred and formed on the outer peripheral surface thereof. As described above, according to the manufacturing method of the present invention, the thermoplastic resin strip is integrally formed in the circumferential direction on the inner peripheral surface of the semiconductive endless belt. When it is used by straddling between a plurality of rollers, by fitting the thermoplastic resin strip into the running guide groove formed in these rollers, it can be used as a conventional running guide portion. You can Further, since the traveling guide portion is integrally formed with the semi-conductive endless belt, it is possible to eliminate the positional deviation during traveling. Moreover, since no adhesive tape is used, the rollers and the like will not get dirty. Further, the thermoplastic resin strip can be integrally formed only by heating and fusing the thermoplastic resin strip, and the production can be easily performed.

Next, the present invention will be described in detail.

The semiconductive endless belt of the present invention accommodates the thermoplastic resin strip in the grooves formed at both ends of the inner cylindrical body, and forms an endless belt between the inner cylindrical body and the outer cylindrical body. A molded thermoplastic sheet is provided and heated in that state.

Polycarbonate (PC), polypropylene (PP) and the like are used as the material of the thermoplastic sheet. The thickness of the sheet is set to 100 to 200 μm. Moreover, PP has a coefficient of thermal expansion of 0.9 to 1.5 × 1.
0 ^-4 (5 to 10 times that of metal), PC is 0.75 x 1
It is 0 ⁻⁴ (4 to 5 times that of metal).

A steel pipe is used as the outer cylinder. The thermal expansion coefficient of this steel pipe is 1.2 × 10 ⁻⁵ . The outer surface temperature (correction temperature) of PP is 160 to 170 ° C.
In the case of PC, the temperature is set to 170 to 180 ° C. The inner peripheral surface of this steel pipe is mirror-finished. As a method of finishing to a mirror surface, a method of honing the inner peripheral surface and then hard chrome plating, a method of coating a heat resistant resin such as silicon, polyimide, or polyethersulfone (PES) on the inner peripheral surface, a method of combining the two, etc. There is. The outer cylindrical body is not limited to the steel pipe, and may be made of a material having a thermal expansion coefficient smaller than that of the heat resistant resin pipe.

A heat resistant resin pipe is used as the inner cylinder. The material of this heat-resistant resin pipe must have heat resistance that can withstand the heating temperature described below and a thermal expansion coefficient of approximately 1 × 10 ⁻⁴ (approximately the same as the thermal expansion coefficient of the thermoplastic sheet). Is required and Teflon is used. In particular, in the case of PTFE (tetrafluoroethylene resin), it can be used even in an atmosphere of a continuous maximum operating temperature of 260 ° C., and the core temperature rises to 140 to 150 ° C.
~ 3mm / diameter about 200 expansion, and coefficient of thermal expansion is 1
It is × 10 ^−4, which is preferable. Also, an aluminum pipe can be used as the inner cylinder. The coefficient of thermal expansion of aluminum is as small as 2.4 × 10 ^-5 , but 140 ~
The temperature rises to 150 ° C and the diameter is 0.4-0.6 mm / diameter 200
Expands to some extent. Due to the Teflon coating on the outer surface of the aluminum pipe, the endless belt having a larger coefficient of thermal expansion (larger contraction) can be demolded.

A groove is formed at one end of the resin pipe. That is, the groove is formed by detachably fitting the ring-shaped body to the small diameter portion on the one end side of the resin pipe. The rotation prevention of the ring-shaped body is performed by fitting the protrusion formed on the ring-shaped body into the groove formed on the small diameter portion.

The material of the thermoplastic resin strip is the same as the material of the thermoplastic sheet (PC, PP).
Etc.) or a material having hardness less than that is used.

As the heating means, for example, a conventionally known oven is used.

As the cooling means, for example, conventionally known air supply means (air blowing pipe, etc.) is used.

The semiconductive endless belt of the present invention is manufactured, for example, as follows. That is, first, the thermoplastic resin strip is housed in the groove formed in the heat resistant resin pipe. In this state, a thermoplastic sheet extruded into an endless belt by an extrusion method is covered on the outside of the resin pipe and inserted into the steel pipe. Next, the whole is put in an oven and heated uniformly. As a result, the thermoplastic sheet and the thermoplastic resin strip are softened, and at the same time, the steel pipe and the resin pipe are expanded. At the time of this expansion, the coefficient of thermal expansion of the resin pipe is larger than the coefficient of thermal expansion of the steel pipe, so the degree of diameter increase of the resin pipe with respect to the steel pipe increases, and the outer peripheral surface of the resin pipe causes the outer circumference of the thermoplastic sheet in the softened state. The surface is pressed against the inner peripheral surface of the steel pipe, and the outer peripheral surface of the thermoplastic resin strip in the softened state is pressed against the inner peripheral surface of the thermoplastic sheet. Therefore, the thermoplastic resin strip is integrally fused to the inner peripheral surface of the thermoplastic sheet. Then, the thermoplastic resin band-shaped body integrally fused serves as a running guide portion. Next, it is cooled and the thermoplastic sheet is removed from the steel pipe and the resin pipe. As a result, the desired semiconductive endless belt is obtained.

However, if the temperature of the steel pipe is too high when the thermoplastic sheet is removed, peeling marks remain on the outer peripheral surface of the thermoplastic sheet. At this time, if the cooling rate of the steel pipe is set to be higher than that of the thermoplastic sheet, it is preferable that air is blown around the steel pipe to cool the steel pipe because the peeling traces do not remain. By this cooling, the thermoplastic sheet and the resin pipe are reduced in diameter in a state of being in close contact with each other. Then,
The ring-shaped body is removed from the small diameter portion of the resin pipe, and the thermoplastic sheet on which the running guide portion is formed is pulled out from the small diameter portion side. As a result, even if the travel guide portion is formed, it does not become an obstacle during the above extraction. At the time of this withdrawal, it is preferable that air is blown between the thermoplastic sheet and the resin pipe to slightly float the thermoplastic sheet from the outer peripheral surface of the resin pipe. During the step of blowing air around the steel pipe and the step of removing the thermoplastic sheet while blowing air between the thermoplastic sheet and the resin pipe, the steel pipe and the resin pipe around which the thermoplastic sheet is wound are loosened. Rotate (1 rpm)
Preferably.

Next, examples will be described.

[0020]

1 is a perspective view of a running guide portion forming apparatus showing an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view thereof. In the figure, 1 is a sheet-shaped thermoplastic resin extruded into an endless belt by an extruder (not shown), and has an inner diameter of 200 to 202 mm and a thickness of 150 to
The width is set to 200 μm and the width is set to 360 mm. PP is used as the thermoplastic resin. 3 is a heat resistant resin pipe, and PTFE is used as the material thereof. As shown in FIG. 2, a small diameter portion 6a is formed at one end of the resin pipe 3, and a groove 7 is formed by detachably fitting the ring-shaped body 5 to the small diameter portion 6a. There is. The small diameter portion 6a and the ring-shaped body 5 are fixed to each other by fitting the groove 3a formed in the small diameter portion 6a and the protrusion 5a formed in the ring-shaped body 5. The thermoplastic resin strip 6 is housed in the groove 7. Further, PTFE is used as the ring-shaped body 5 and PP is used as the thermoplastic resin band-shaped body 6. Reference numeral 4 is a steel pipe having an inner diameter of 202 mm and a width of 380 mm. The inner peripheral surface of the steel pipe 4 is mirror-finished by honing. In some cases, after this mirror-finishing, the surface may be further coated with silicon, polyimide, polyether sulfone or the like to prevent the molten thermoplastic resin from adhering to the surface.

In the above structure, first, the resin pipe 3
The thermoplastic resin strip 6 is disposed in the groove 7 of the above, and in that state, the thermoplastic sheet 1 formed into an endless belt by extrusion molding is covered on the outside of the resin pipe 3 and inserted into the steel pipe 4. .. Then, the whole is placed in an oven and uniformly heated to 175 ° C. As a result, as shown in FIG. 4, the thermoplastic sheet 1 and the thermoplastic resin strip 6 are softened, the resin pipe 3 is expanded, and the outer peripheral surface of the softened thermoplastic sheet 1 is expanded. The outer peripheral surface of 3 is pressed against the inner peripheral surface of the steel pipe 4, and the outer peripheral surface of the softened thermoplastic resin strip 6 is pressed against the inner peripheral surface of the thermoplastic sheet 1. Therefore, the thermoplastic sheet 1
At the same time, the outer peripheral surface of is transferred to a mirror surface, and at the same time, the thermoplastic resin strip 6 is integrally fused to the inner peripheral surface of the thermoplastic sheet 1 (see FIG. 5). Next, it is cooled and the thermoplastic sheet 1 is removed from the steel pipe 4. In this case, air is blown to the steel pipe 4 to remove the steel pipe 4 and the thermoplastic sheet 1. Next, the ring-shaped body 5 is removed from the small-diameter portion 6a of the resin pipe 3, and then air is blown between the thermoplastic sheet 1 and the resin pipe 3 to remove the thermoplastic sheet 1 from the resin pipe 3. After that, as shown in FIG. 6, the cutter 8 cuts the surplus portion at one end of the thermoplastic sheet 1.

When the semiconductive endless belt 10 thus obtained is bridged over the rollers, the thermoplastic resin strip 6 integrally fused with the belt is used as the running guide portion 2.
And is fitted into the running guide grooves formed at both ends of the roller. Therefore, it is possible to eliminate the occurrence of displacement during traveling, and since the adhesive tape is not used, the rollers and the like are not contaminated. Further, the traveling guide portion 2 can be integrally formed on the belt 10 by simply fusing the thermoplastic resin strip 6 to the semiconductive endless belt 10 by heating, and the traveling guide portion 2 can be easily formed. Further, there is an advantage that the outer peripheral surface of the semiconductive endless belt 10 can be transferred and formed on a mirror surface.

In the above embodiment, the inner peripheral surface of the steel pipe 4 is finished to be a mirror surface, but the invention is not limited to this, and the inner peripheral surface of the steel pipe 4 may be finished to a satin finish by shot blasting.

Further, although the resin pipe 3 in which the ring-shaped body 5 is detachably provided is used in the above embodiment, the resin pipe 3 in which the ring-shaped body 5 is integrally provided may be used. In this case, it is necessary to forcefully remove the thermoplastic sheet 1, but if the resin pipe 3 made of Teflon is used, the slipperiness is good, so there is no problem. Alternatively, the thermoplastic resin strip 6 may be fused to both ends of the semiconductive endless belt 10.

[0025]

As described above, according to the semiconductive endless belt obtained by the present invention, since the running guide portion can be formed in the circumferential direction on the inner peripheral surface of the semiconductive endless belt, the semiconductive endless belt can be formed. When the conductive endless belt is used while being stretched between a plurality of rollers, by fitting the above-mentioned running guide portion into the running guide groove formed in these rollers,
It is possible to eliminate misalignment during traveling. Moreover, since no adhesive tape is used, the rollers and the like will not get dirty. Further, according to the manufacturing method of the present invention, the running guide portion can be integrally formed only by heat-sealing the thermoplastic resin strip to the thermoplastic sheet, and the manufacturing can be easily performed.

[Brief description of drawings]

FIG. 1 is a perspective view of a running guide portion forming apparatus showing an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view thereof.

FIG. 3 is a perspective view of a heat resistant resin pipe used in the above apparatus.

FIG. 4 is an enlarged cross-sectional view of a main part of the device in a heated state.

FIG. 5 is an enlarged cross-sectional view of a main part of the apparatus in a cooled state.

FIG. 6 is an enlarged cross-sectional view of an end portion of a semiconductive endless belt molded by the above device.

FIG. 7 is a cross-sectional view of the semiconductive endless belt with the end portions cut off.

FIG. 8 is an enlarged cross-sectional view showing an end portion of a conventional semiconductive endless belt.

FIG. 9 is a configuration diagram of a full-color copying machine incorporating an intermediate transfer endless belt.

[Explanation of symbols]

 1 Thermoplastic Sheet 2 Travel Guide 3 Heat Resistant Resin Pipe 4 Steel Pipe 6 Thermoplastic Resin Band 7 Groove

Claims (1)

Claim: What is claimed is: 1. An inner cylindrical body having a groove formed in a circumferential direction on an outer peripheral surface thereof is disposed in an outer cylindrical body having a thermal expansion coefficient smaller than that of the inner cylindrical body. The thermoplastic resin strip is housed in the groove of the outer periphery of the inner cylinder and the outer periphery of the inner cylinder is provided with a thermoplastic sheet molded into an endless belt, and in that state, at least the inner cylinder and The thermoplastic sheet is heated, and by this heating, the thermoplastic sheet and the thermoplastic resin strip are softened, and the inner cylinder is expanded, and the inner peripheral surface of the inner cylindrical body is heated to the inner peripheral surface of the outer cylindrical body. The outer peripheral surface of the thermoplastic sheet is pressed against the inner peripheral surface of the thermoplastic sheet, and the outer peripheral surface of the thermoplastic resin is pressed against the inner peripheral surface of the thermoplastic sheet. To be fused to Preparation of semiconductive endless belt to symptoms.