JP2006095838A - Seamless belt and method for producing seamless belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seamless belt which can obtain a high precision image by using it for a transfer unit transferring a toner on the drum of an image forming device to paper or an intermediate transfer unit mixing four primary colors when a latent image is formed in color. <P>SOLUTION: In a method for producing the seamless resin belt, a rolled sheet or film of a thermoplastic resin which satisfies one of the conditions that its glass transition temperature is 100-300°C and its melting point is 200-400°C is inserted into a tubular mold member, and the end parts of the sheet or the film are heated and welded together. A seat belt is obtained from the seamless belt. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for producing a resin seamless belt and a resin seamless belt. Specifically, a transport belt used for transporting precision parts to a predetermined position with a high accuracy of position accuracy, an annular belt for a sealed enclosure for storing and storing articles, The present invention relates to a method for manufacturing a resin seamless belt used as a functional component of an image forming apparatus and a resin seamless belt.
In particular, resistance (conductivity) suitable for use as a component of image forming apparatuses such as electrophotographic copying machines and laser printers, which are formed with high precision in shapes such as wall thickness, cylindricity, and roundness. The present invention relates to a controlled resin seamless belt and a method for producing a resin seamless belt. In addition, in this specification, a tube-shaped film molded object etc. are demonstrated as what is contained in a resin seamless belt.

When using a conductively controlled seamless belt as a transfer belt or an intermediate transfer belt of an image forming apparatus, the resin is a non-thermoplastic type polyimide resin considering durability or a fluorine resin considering toner releasability. Etc. are mainly used.

Conventionally, there are mainly the following four methods for producing a resin seamless belt.
(1) Extrusion hot melt molding method typified by inflation method (2) Resin or precursor thereof is put into a solution state, and a predetermined amount is applied onto the inner surface or outer surface of the tubular mold, followed by solvent removal treatment (heat treatment as necessary) (3) A method in which a sheet-like film is wound around a core body, and both ends of the sheet are welded to line the inner surface of the hollow tubular body (Japanese Patent Laid-Open Nos. 63-34120 and 63). Disclosed in Japanese Patent No. -34121)
(4) In a state where the sheet-like film is wound around the cylindrical member so that the winding start portion and the winding end portion are overlapped, the sheet-like film is fitted into the tubular mold member, and then the whole is heated, so that the overlapping portion of the sheet-like film is Method of forming a resin belt from a sheet-like film by bonding (disclosed in JP-A-8-187773)
In addition, in this method (4), it has already been disclosed that the shape of the belt to be completed can be controlled with high accuracy by setting the thermal expansion coefficients of the cylindrical member and the tubular mold member to be used to be cylindrical member> tubular mold member.
JP-A-63-34120 JP-A 63-34121 JP-A-8-187773

  In consideration of the durability of the transfer belt and the intermediate transfer belt, the non-thermoplastic type polyimide resin is often selected. However, as a seamless belt manufacturing method, the conventional method (2) (casting method) or similar is used. In this method, in order to obtain a film having a uniform thickness, it is necessary to perform concentration control of the solution, adjustment of the drying atmosphere, solvent treatment in the drying process, etc. There is a problem that the manufacturing process is complicated and the manufacturing cost is increased as a result. Particularly for polyimide resins, the time required for the imidization reaction is long, and in particular, it is often a high-price seamless belt.

In addition, the above-mentioned (1), (4) and the like have been put into practical use as a relatively inexpensive method for producing a seamless belt. In particular, in the conventional method (1) (extrusion hot melt molding method) described above, an inflation method or the like is used. The seamless resin belt manufactured by the method is crushed when the film is wound in the molding process, and the film can be folded. When this resin belt is used in a transfer device of an image forming apparatus, the folds in the film may cause inconvenience for normal image formation. Further, in the obtained extrusion hot melt molding method, the seamless resin belt has a large film thickness unevenness, which adversely affects image formation. In general, the conventional methods (1) and (4) cannot be selected for the polyimide resin that does not exhibit thermoplasticity.

  As a means for solving the above problems, it is considered to use a thermoplastic resin or a resin composition having similar mechanical properties to the polyimide resin. For example, as shown in JP-A-6-254941, polyether ether An example in which a ketone resin is used and manufactured using the conventional (1) has been reported.

However, according to this, it is difficult to obtain a desired cost and high accuracy (film thickness uniformity), and it is preferable to select (4) as a manufacturing method.
Therefore, an object of the present invention is to use a seamless belt manufacturing method capable of achieving high productivity, low cost, and high accuracy with the conventional method (4), and has a mechanical property and durability performance of a non-thermoplastic type. It is to provide a seamless belt similar to the characteristics of polyimide resin.

The present invention relates to a seamless resin in which a sheet or a sheet-like film made of a thermoplastic resin or a thermoplastic resin composition containing the same is fitted in a tubular mold member and the ends of the sheet or the sheet-like film are thermally welded together. Using the belt manufacturing method,
The thermoplastic resin to be wound is characterized in that it satisfies at least one of the glass transition point of 100 ° C. or more and 300 ° C. or less, or the melting point of 200 ° C. or more and 400 ° C. or less.

In particular, the thermoplastic resin composition is preferably a material mainly composed of a polyetheretheretherketone resin (PEEK) containing a conductive filler. The poly ether ether ketone resin (PEEK) includes poly ether ether ketone resin (PEEK), poly ether ketone resin (PEK), poly ether ketone ketone resin (PEKK). Poly, allyl ether, ketone resin (PAEK) and the like.
In addition, the thermoplastic resin composition contains a poly ether sulfone resin (PES), a poly ether imide resin (PEI), a liquid crystal polymer resin (LCP), a thermoplastic polyimide resin containing a conductive filler ( A material having TPI) as a main component is preferable.

The volumetric electrical resistivity of the seamless belt produced from the thermoplastic resin composition sheet containing the conductive filler is in the range of 10 ⁷ to 10 ¹⁶ Ωcm, preferably 10 ⁸ to 10 ¹² . It is effective that the maximum to minimum ratio of volume resistivity is less than 100, preferably 1 to 10.
The seamless resin belt produced by the present invention is effective as a transfer belt or an intermediate transfer belt for an image forming apparatus. That is, when the seamless resin belt of the present invention is used in a transfer unit that transfers toner on a drum to paper or an intermediate transfer unit that mixes four primary colors when a latent image is formed on a color in an image forming apparatus. Can be obtained.

According to the present invention, a sheet or a sheet-like film made of a thermoplastic resin or a thermoplastic resin composition containing the same is fitted into a tubular mold member and the ends of the sheet or the sheet-like film are heat-welded to each other. Use the seamless resin belt manufacturing method,
By using a resin that satisfies at least one of the conditions that the glass transition point of the thermoplastic resin to be wound is 100 ° C. or higher and 300 ° C. or lower, or the melting point is 200 ° C. or higher and 400 ° C. or lower. A seamless belt having the same durability as that of the polyimide resin seamless belt was obtained.

In particular, a more preferable seamless belt could be obtained by using a material in which the thermoplastic resin composition is composed mainly of a polyetheretherketone resin (PEEK) containing a conductive filler.
In addition, the thermoplastic resin composition contains a poly ether sulfone resin (PES), a poly ether imide resin (PEI), a liquid crystal polymer resin (LCP), a thermoplastic polyimide resin containing a conductive filler ( A preferable seamless belt could be obtained in the same manner even when a material mainly composed of TPI) was used.
The seamless resin belt produced according to the present invention was effective as a transfer belt or an intermediate transfer belt for an image forming apparatus. That is, when the seamless resin belt of the present invention is used in a transfer unit for transferring toner on a drum to paper in an image forming apparatus or an intermediate transfer unit for mixing four primary colors when a latent image is formed in a color, higher definition is achieved. I was able to get an image.

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

  FIG. 1 shows a step of winding the sheet-like film 1 into an annular shape as shown in FIG. 1 in the seamless resin belt manufacturing process of the present embodiment, with a gap between the winding start portion A and the winding end portion B. In such a state, the thermoplastic sheet-like film 1 is wound around the cylindrical member 2, and then heated in a state of being fitted in the tubular mold member 3 as shown in FIG. 2, including the overlapping portion of the sheet-like film 1, It is formed by welding each other. According to this, the uniformity of thickness can be improved over the entire resin belt, the manufacturing process is not very complicated, and the manufacturing cost can be kept low.

Hereinafter, specific examples of the present invention will be described in detail.
[Example 1]
In the present embodiment, as described above, the columnar member 2 (referred to as a columnar member including a cylindrical member in this specification) that is a mandrel member around which the sheet-like film 1 is wound, and the sheet-like film 1. In addition, a hollow tubular member 3 that covers the cylindrical member 2 is used.

In this embodiment, a thermoplastic sheet-like film 1 made of a polyether ether ketone resin (PEEK resin: Pictrex) is used. This thermoplastic sheet-like film 1 is kneaded and formed as a film having a thickness of 50 μm by a hot melt extrusion molding machine (not shown), mixed with ketjen black particles and a flame retardant reinforcement as internal additives, and has a volume resistance value of 10 ^It is formed so as to be ¹⁰ Ωcm, and is cut into a sheet having a length of 1890 mm × width of 330 mm.

The columnar member 2 of the present embodiment is a hollow member formed of an aluminum material having a wall thickness of 15 mm. The outer diameter is 300.00 mm, the inner diameter is 270.00 mm, the length is 350 mm, and the thermal expansion coefficient is It is larger than the thermal expansion coefficient of the tubular mold member and is 2.40 × 10 ⁻⁵ (/ ° C.).
On the other hand, the tubular mold member 3 is made of stainless steel, and its inner surface is subjected to nickel plating coating in consideration of releasability from the sheet-like film 1. The tubular mold member 3 has an outer diameter of 320.00 mm, an inner diameter of 300.60 mm, a length of 350 mm, and a thermal expansion coefficient of 1.20 × 10 ⁻⁵ (/ ° C.).
In the present embodiment, the dimensions of the cylindrical member 2 and the tubular mold member 3 are the same as the outer diameter of the cylindrical member 2 and the tubular mold member 3 at the time of heating in the heating step described later, that is, at a heating temperature of 370 ° C. It is designed so that the difference in the inner diameter dimension of each becomes 100 μm.

 Next, a method for manufacturing a resin belt according to this embodiment will be described.

  First, as shown in FIG. 1, the sheet-like film 1 is wound around the outer peripheral surface of the columnar member 2 twice. And as shown in FIG. 3, the clearance gap d between the position of the winding start part A of the sheet-like film 1 and the winding end part B shall be 3 mm.

Next, the columnar member 2 around which the sheet-like film 1 is wound is inserted into the hollow portion of the tubular mold member 3. This state is shown in FIG.
Then, it transfers to a heating process. The fitting body of the columnar member 2, the sheet-like film 1, and the tubular mold member 3 shown in FIG. 5 is inserted and arranged in the heating furnace 7 shown in FIG. In the heating furnace 7, the internal temperature is controlled by a temperature sensor and a temperature control device (not shown). In this embodiment, the fitting body of the cylindrical member 2, the sheet-like film 1, and the tubular mold member 3 is heated at 370 ± 5 ° C. for 60 minutes.
In the present embodiment, a method of leaving in a heating furnace was adopted as a heating method. For example, as shown in Japanese Patent Application No. 11-332065, a method of heating by rotating a lamp heater is used. Any heating method may be adopted as long as the temperature of the fitting body can be increased.

 In the heating process in the heating furnace 7, the fitting body of the cylindrical member 2, the sheet-like film 1, and the tubular mold member 3 changes as shown in FIGS.

As shown in FIG. 6, in the state before heating, the sheet-like film 1 is located between the columnar member 2 and the tubular mold member 3, and the gap between the outer diameter of the columnar member 2 and the inner diameter of the tubular mold member 3 is 1. 20 mm (600 μm on one side).
From this state, the fitting body of the cylindrical member 2, the tubular mold member 3, and the sheet-like film 1 is heated in the heating furnace 7, and the respective temperatures rise. The cylindrical member 2 and the tubular mold member 3 start to expand according to their respective thermal expansion coefficients. Moreover, the sheet-like film 1 starts to soften as the temperature rises. Since the thermal expansion coefficient of the cylindrical member 2 is larger than that of the tubular mold member 3, the gap between the tubular mold member 3 and the cylindrical member 2 becomes narrower during non-heating as shown in FIG.

  When the predetermined heating temperature is reached, the gap between the columnar member 2 and the tubular mold member 3 has a desired size of 0.2 mm (100 μm on one side). Therefore, the softened sheet-like film 1 has a desired film thickness (substantially the same thickness as the gap) due to the stress generated by the difference in the coefficient of thermal expansion between the cylindrical member 2 and the tubular mold member 3. It becomes). In particular, since the joining portion of the sheet-like film receives stress in the heating process, it is welded and joined as shown in FIG. Thereby, the thickness of the resin belt becomes uniform over the entire circumference.

After performing the above-mentioned heating process for 60 minutes, the fitting body of the cylindrical member 2, the tubular mold member 3, and the sheet-like film 1 is taken out from the heating furnace 7 and cooled to room temperature. When each member drops to about room temperature in the cooling step, the cylindrical member 2 and the sheet-like film 1 are removed from the tubular mold member 3, and the sheet-like film 1 is peeled from the cylindrical member 2.
The thickness of the film connecting portion of the PEEK resin seamless belt made of the sheet-like film 1 thus obtained is 100 μm ± 10 μm, and a seamless belt having a small variation in thickness over the entire resin belt can be obtained.
Next, an example of the usage pattern of the resin belt manufactured by this method will be described. In this embodiment, rubber rib members (not shown) for preventing meandering are adhered to both ends in the width direction of the resin belt manufactured by the above-described method, and the image forming apparatus (copier, laser) shown in FIG. It is used as a transfer belt 9 for conveying a toner carrier and transferring an image of a beam printer or the like.

  The image forming apparatus shown in FIG. 9 has a rotatable photosensitive drum 10, and around this photosensitive drum 10, a charging charger 11, an optical writing device 12 using laser light, and a developing device for containing toner. 13 are arranged. Further, the transfer belt 9 which is the resin belt of the present invention described above is stretched across four rollers (only two rollers 15 and 16 are shown in FIG. 9) and is arranged in the horizontal direction. A transfer blade 20 is provided in the vicinity of a part of the belt 9. Further, a fixing device 21 and a fixing film 22 are arranged on the downstream side (left side in FIG. 9) with respect to the traveling direction of the transfer paper 19.

  In the image forming apparatus having such a configuration, the photosensitive drum 10 is rotationally driven in the arrow direction at a constant speed Vf. First, the surface of the photosensitive drum 10 is uniformly charged by the charging charger 11, and an electrostatic latent image is formed by the optical writing device 12 using laser light. Then, the toner 14 charged with charge from the developing device 13 adheres to the electrostatic latent image portion, and is visualized as a toner image.

On the other hand, the transfer belt 9 circulates in the direction of the arrow at a constant speed Vf similarly to the photosensitive drum, and the transfer paper 19 is electrically attracted to the transfer belt 9 by the action of the transfer charger 20 and is conveyed at the constant speed Vf. The When the transfer paper 19 reaches the transfer area, the toner 14 visualized on the photosensitive drum 10 is transferred to the transfer paper 19 by the transfer charger 20. Thereafter, the transfer paper 19 is further conveyed downstream (left side in FIG. 9), and the toner image is fixed by the fixing device 21 and the fixing film 22.
In the configuration described above, the transfer belt 9 uses and processed a sheet shape that can be manufactured with extremely high film thickness accuracy to obtain a seamless belt, so the uniformity of the belt thickness is very high, High image quality was achieved. In addition, since PEEK resin is used as the thermoplastic resin, its mechanical properties are similar to those of polyimide resin (Table 1), and there is no occurrence of defects such as bending or breaking in long-term use, and a stable image can be obtained over a long period of time. I was able to get it.

[Examples 2 to 5]
In this example, a poly ether sulfone resin (PES), a poly ether imide resin (PEI), a liquid crystal polymer resin (LCP), and a thermoplastic polyimide resin (TPI) were used as the thermoplastic resin to be used. . The manufacturing method of the seamless resin belt is the same as that in Example 1.

Table 1 summarizes the temperature characteristics and mechanical characteristics of each thermoplastic resin at that time, and the durability results when each of them is used as an intermediate transfer belt for an image forming apparatus.
According to this, it was found that there is a correlation between the glass transition point and melting point of the resin and the durability of the image forming apparatus, and the higher the respective values, the better the durability of the actual machine.

[Comparative Example 1]
Table 1 shows an example in which a polyvinylidene fluoride resin (PVDF) is used as the thermoplastic resin and a seamless belt produced by the same production method as in Example 1 is used as an intermediate transfer belt.
According to this, the thermal properties and mechanical properties with the resins mentioned in the examples were clearly different from those of the polyimide resin, and the actual machine durability was inferior to the others.

It is explanatory drawing of the state which wound the sheet-like film around the column member. It is explanatory drawing of the combination of a cylindrical member and a tubular member. It is explanatory drawing which shows the clearance gap between the position of the winding start part A of the sheet-like film 1, and the winding end part B. FIG. It is explanatory drawing of a heating furnace. It is explanatory drawing of the relationship of a cylindrical member, a sheet-like film, and the fitting body of a tubular type member. It is explanatory drawing of the winding state of a sheet-like film. It is explanatory drawing of the state of the film between a cylindrical member and a tubular member. It is explanatory drawing of the state of the film between the cylindrical member and tubular member at the time of heat joining. It is explanatory drawing of an image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermoplastic sheet-like film 2 Cylindrical member 3 Tubular type | mold member 7 Heating furnace 9 Transfer belt 10 Photosensitive drum 11 Charging charger 12 Optical writing device 13 Developer 14 Toner 15 Drive roller 16 Drive roller 17 Drive roller 18 Drive roller 19 Paper ( Transfer paper)
20 Transfer blade 21 Fixing device 22 Fixing film

Claims (13)

(1) Glass transition point is 100 ° C. or higher and 300 ° C. or lower,
(2) A sheet obtained by extruding a thermoplastic resin satisfying at least one of the conditions of melting point of 200 ° C. or higher and 400 ° C. or lower or a thermoplastic resin composition containing the same is cut into a predetermined size. A method of manufacturing a seamless belt, characterized by winding it around a cylindrical member and joining the winding start and winding end.   Extruding and molding a thermoplastic resin satisfying at least one of a glass transition point of 100 ° C. or more and 300 ° C. or less, or a melting point of 200 ° C. or more and 400 ° C. or less The obtained sheet is cut into a predetermined size, wound around a cylindrical member, and an overlapping portion is formed so that a part of the winding start and the winding end overlap each other. The method for manufacturing a seamless belt according to claim 1, wherein the overlapping portions are joined with a time interval.   Extruding a thermoplastic resin satisfying at least one of the glass transition point of 100 ° C. or more and 300 ° C. or less, or the melting point of 200 ° C. or more and 400 ° C. or less, or a thermoplastic resin composition containing the same into a sheet, The sheet is wound around a cylindrical member, the winding start and end of the sheet are overlapped, a tubular mold member is fitted to the outside of the wound sheet, and then at least the sheet is heated to join the overlapping portion The method for producing a seamless belt according to claim 1, wherein the method is tubular. A seamless seat belt obtained by the production method according to claim 1.   The seamless thermoplastic resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a material mainly composed of a polyether ether ketone resin (PEEK) containing a conductive filler. A method for manufacturing a belt.   Examples of the poly ether ether ketone resin (PEEK) include poly ether ether ketone resin (PEEK), poly ether ketone resin (PEK), poly ether ketone ketone resin (PEKK), The method for producing a seamless belt according to claim 5, which is a polyallyl ether ketone resin (PAEK).   The seamless belt according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a material mainly composed of a poly ether sulfone resin (PES) containing a conductive filler. Production method.   The seamless belt according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a material mainly composed of a polyetherimide resin (PEI) containing a conductive filler. Production method.   The method for producing a seamless belt according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a material mainly composed of a liquid crystal polymer resin (LCP) containing a conductive filler.   The method for producing a seamless belt according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a material mainly composed of a thermoplastic polyimide resin (TPI) containing a conductive filler. . A seamless seat belt obtained by the production method according to claim 5. The volumetric electrical resistivity of the seamless belt manufactured by the thermoplastic resin composition sheet containing the conductive filler is in the range of 10 ⁷ to 10 ¹⁶ Ωcm, and the maximum and minimum ratios of the volume electrical resistivity in the respective parts. The seamless belt according to any one of claims 5 to 10, wherein is less than 100.   The seamless belt obtained by the production method according to claim 1, wherein the seamless belt is used as a film or belt for transfer, intermediate transfer and fixing of an image forming apparatus.

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