JP2003094462A - Seamless tubular article, its manufacturing method, and image forming apparatus using obtained seamless tubular article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for inexpensively manufacturing a seamless tubular article having a high product yield and the seamless tubular article having a high accuracy obtained by the method and to provide an image forming apparatus using the obtained seamless tubular article. SOLUTION: The method for manufacturing the seamless tubular article made of a heat resistant resin composition comprises a coating step of coating the surface of a core made of a metal covered with a coating layer made of an organoalkoxide layer with a liquid-like heat resistant resin composition, a solidifying step of solidifying or curing the liquid-like heat resistant resin composition coating on the surface of the core, and a separating step of separating the solidified or cured heat resistant resin composition from the core. The seamless tubular article is obtained by the method. The image forming apparatus uses the seamless tubular article.

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 seamless tubular article which is preferably used for a photoconductor, a transfer belt, a fixing belt, a bias roll and the like in electrophotographic equipment such as copying machines and printers.

[0002]

2. Description of the Related Art In electrophotographic equipment, a rotating body made of metal, various plastics or rubber is used for a transfer belt, a fixing belt, a bias roll and the like. In order to reduce the size and improve the performance of the device, it may be preferable that these rotating bodies be deformable to some extent. In that case, a tubular member made of a thin plastic film is used. At that time, if there is a seam in the tubular object, a defect due to the seam occurs in the output image. Therefore, it is necessary to use a seamless tubular object (seamless tubular object).

Regarding a method for producing a seamless tubular article, for example, JP-A-60-170862 discloses a method of forming a film on the inner peripheral surface of a mold by a rotational molding method, and JP-A-6-202513 discloses. A method of melting and extruding a resin into a ring to form a film, and JP-A-6-222695 discloses a method of applying a resin solution to the outer surface of a cylindrical mold by dipping to a constant thickness, and then pulling out the mold after heating and forming a film. Have been described.

Examples of the resin material for forming this seamless tubular material include polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyphenylene sulfide, and the like. Among these, strength, heat resistance, and dimensional stability. A polyimide resin is particularly preferable from the viewpoint of the property.

In the meantime, in order to manufacture a seamless tubular product made of a polyimide resin, there is a problem that extrusion molding, inflation or vacuum molding cannot be performed like a tubular product made of a thermoplastic resin. Therefore, as a method for producing a seamless tubular product made of polyimide, there is no choice but to adopt a method in which the precursor polyamic acid solution is applied to a mold or the like, and is imidated by heating to remove the mold.

[0006] On the other hand, in these methods for producing a seamless tubular article, a metal such as aluminum or stainless steel is generally used as the material of the die. However, the polyimide resin is a resin used as an adhesive, and when a polyamic acid solution is applied to a mold or the like and the imide is converted by heating, the polyimide tubular material shrinks and adheres or adheres to the mold, Due to the binding force, it is difficult to remove the polyimide tubing from the mold.

When the polyimide precursor solution is applied to the surface of the mold (core) and heated to convert the imide to obtain a seamless tubular product, the seamless tubular product is smoothly separated from the mold. Therefore, a method of coating the surface of the mold with a mold-releasing resin to reduce the adhesive energy on the surface is considered. However, lowering the adhesive energy on the surface of the core causes many problems such as cissing and flow that occur when the liquid polyimide precursor is applied to the surface of the core.

With respect to the above problems, Japanese Patent Laid-Open No. 10-159
In the '68 publication, a porous ceramic cylindrical core is used as a core to form a polyimide tubular body, and then a liquid is exuded from pores from the inside to the outside of the cylindrical core by the exuded liquid, A method has been proposed in which the adhesive force between the outer surface of the core body and the polyimide tubular material is weakened and then the polyimide tubular material is separated. However, this method has a problem that the manufacturing process is complicated.

Further, in Japanese Patent Application Laid-Open No. 3-261518,
As a method of improving the cissing phenomenon and flow phenomenon of the polyimide precursor solution and smoothly separating the tubular body and the core body, a method of providing a hydrophilic coating film such as polyvinyl alcohol on the release layer is proposed. Has been done. However, in the method of using the core body coated with the release resin, to form a thin coating film having hydrophilicity on the outer surface thereof, and further coating a polyimide precursor solution on the hydrophilic film to obtain a tubular article, The polyimide precursor solution, which is a thermosetting resin, needs to be completely converted into an imide, and a temperature of 250 to 450 ° C. is necessary.

Further, in the production of a seamless tubular article made of a polyimide resin, for example, as disclosed in JP-A-10-1000171 and JP-A-10-296761, a polyimide precursor is formed on the inner surface of a cylindrical body. A centrifugal molding method in which the solution is developed and dried while rotating. JP-A-1-
The inner surface coating method disclosed in Japanese Patent No. 139228 is mentioned. However, all of these methods require a temperature of 250 to 450 ° C. in order to completely convert the polyimide precursor solution, which is a thermosetting resin, into an imide.

In the production of a seamless tubular product made of a polyimide resin, which requires the complete imide conversion of the polyimide precursor solution, as described above, 250 to 450.
A temperature of ℃ is required, but there is no mold release agent or mold release resin that can withstand these high temperatures, and therefore, the polyimide precursor solution is applied to the surface of the core body coated with the mold release resin as the first step. After the imidization proceeds at 100 to 200 ° C. to form an intermediate, the intermediate is separated from the core, and as a second step, the tubular body is again inserted into the metal-only core to obtain 250 to 45.
It was necessary to complete the imidization at 0 ° C. That is,
The manufacturing method is not only complicated in the manufacturing process,
Since the tubular object is taken out at the intermediate stage of imidization and attached to another metal core body, foreign matter such as dust is caught between the polyimide film and the core body at the time of remounting. This also causes a problem that the yield is reduced.

Further, in Japanese Patent Laid-Open No. 1-156017,
In order to obtain a tubular product with a uniform thickness, the polyimide acid solution is poured onto the inner surface of a molded tube such as a glass tube or a stainless steel tube having a smooth inner surface, and then the molded tube is held vertically, A method has been proposed in which a running body such as a bullet-shaped body or a spherical body is dropped by its own weight to form a certain thickness, and then dried and imidized by heating to form a tubular body, and then extracted from a molded pipe. However, with the above-mentioned method, it is very difficult to remove the polyimide tubular material from the inner surface of the molded tube such as a glass tube or a stainless tube. In addition, since the polyimide tubular product is taken out from the inside of the molded tube, it is difficult to produce a tubular product having a small inner diameter, and it is also very difficult to produce a long product.

Therefore, Japanese Patent Application Laid-Open No. 7-76025 proposes a method of forming an inorganic coating layer made of an inorganic compound on the surface of a metal core. But,
The method of coating the surface of the metal core body with a heat-resistant material such as an inorganic coating layer is not sufficient in releasing performance of the inorganic coating layer, and in addition, heating at 250 ° C. or higher is required in the ceramicizing step after coating. Since it was necessary, workability was poor, and the adhesive strength between the surface of the metal core and the inorganic coating layer was not sufficient.

Furthermore, since there is a difference in the coefficient of thermal expansion between the surface of the metal core and the inorganic coating layer, there is a problem that the inorganic coating layer is cracked when heating and cooling are repeated (for example, the metal core). The coefficient of linear expansion of the SiO ₂ used as the inorganic coating layer is as small as 7 to 8 × 10 ⁻⁶ ° C. while the coefficient of linear expansion of stainless steel used as 1.15 × 10 ⁻⁵ ° C.). The above problems also occur with other heat-resistant resin compositions having the same properties as polyimide.

[0015]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a seamless tubular article having a high product yield and low cost, and a highly accurate seamless tubular article obtained by the production method, and an obtained seamless article. An object of the present invention is to provide an image forming apparatus using a tubular product.

[0016]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be achieved by the following invention, and completed the invention. It was That is, the present invention is

<1> A method for producing a seamless tubular article made of a heat-resistant resin composition, wherein a liquid heat-resistant resin composition is applied to the surface of a metal core covered with a coating layer made of an organoalkoxide compound. The application step of applying, a solidification step of solidifying or curing the liquid heat-resistant resin composition applied to the surface of the metal core, and the solidified or cured heat-resistant resin composition, the metal core A method for producing a seamless tubular article, comprising: a separation step of separating from a body.

<2> The coating step is a step of coating the polyimide precursor solution as the liquid heat-resistant resin composition to a uniform thickness on the surface of the metal core covered with the coating layer. The solidification step is a step of heating the applied polyimide precursor solution to cause an imide conversion reaction, which is a method for producing a seamless tubular article according to <1>.

<3> The method for producing a seamless tubular article according to <2>, wherein a conductive agent is dispersed in the polyimide precursor solution. <4> The coating layer made of the organoalkoxide compound is a coating layer obtained by coating the metal core with a coating liquid of an organoalkoxide compound and baking the coating by heating. 3> The method for producing a seamless tubular product according to any one of 3>.

<5> In the coating step, the metal core is rotated to move at a constant speed in the axial direction of the metal core covered with the coating layer, and a certain amount of liquid heat resistance is obtained. The method for producing a seamless tubular article according to any one of <1> to <4>, which is a step of applying the resin composition to the surface of the metal core body. <6> A seamless tubular article produced by the method for producing a seamless tubular article according to any one of <1> to <5>.

<7> The arithmetic average roughness Ra of the coating layer made of the organoalkoxide compound is 0.5.
The seamless tubular article according to <6>, wherein the seamless tubular article has a thickness of up to 1.5 μm. <8> An image forming apparatus including a roll type transfer device, wherein the bias roll of the transfer device is <6> or <
7> is an image forming apparatus characterized by using the seamless tubular article.

According to the method for producing a seamless tubular article of the present invention, a liquid heat-resistant resin composition such as a polyimide precursor solution is provided on the surface of a metal core body covered with a coating layer made of an organoalkoxide compound. By applying a uniform thickness and heating to solidify or cure the imide conversion reaction or the like, and by separating the seamless tubular product from the metal core, the manufacturing process can be made one process, A seamless tubular product whose main component is a heat-resistant resin such as high polyimide can be obtained at a high product yield and at low cost.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a seamless tubular article of the present invention comprises a coating step of coating a liquid heat-resistant resin composition on the surface of a metal core body covered with a coating layer made of an organoalkoxide compound. A solidifying step of solidifying or curing the liquid heat-resistant resin composition applied to the surface of the metal core, and a separation for separating the solidified or cured heat-resistant resin composition from the metal core And a process.

The method for producing a seamless tubular article made of the heat-resistant resin composition of the present invention will be described below by taking polyimide, which is a typical heat-resistant resin composition, as an example. The method for producing a seamless tubular product containing polyimide as a main component (hereinafter, simply referred to as “polyimide seamless tubular product”) can be applied to a heat resistant resin composition having the same properties as polyimide. . Specifically, instead of the polyimide precursor solution, a liquid heat-resistant resin composition other than polyimide is applied to the surface of the metal core covered with the coating layer, and the liquid heat-resistant resin composition is applied. A solid tubular product made of a heat-resistant resin composition other than polyimide can be obtained by a method of solidifying or curing the resin and separating it from the metal core.

The method for producing the seamless tubular article of the present invention comprises:
Start with the coating process. First, the coating process in the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a metal core body on the surface of which a coating layer made of an organoalkoxide compound and a coating layer made of a polyimide precursor are formed.
In FIG. 1, reference numeral 11 denotes a metal core body. Metal core 1
The surface of 1 is covered with a coating layer 12 made of an organoalkoxide compound, and further, with a polyimide precursor,
The coating layer 13 is formed. The coating step in the present invention refers to a step of coating the surface of the metal core 11 covered with the coating layer 12 made of an organoalkoxide compound with a polyimide precursor solution to obtain a coating layer.

<Coating Layer Made of Organoalkoxide Compound> The coating layer made of an organoalkoxide compound covering the surface of the metal core is made of an organoalkoxide compound of an inorganic element described later. The organoalkoxide compound has excellent compatibility with the polyimide precursor solution and is not affected by the organic polar solvent in the precursor solution at all. Therefore, by providing a coating layer composed of the organoalkoxide compound,
Even in the coating step of forming the polyimide precursor solution on its surface in a liquid state, neither the cissing phenomenon nor the flow phenomenon of the polyimide precursor solution occurs. Also in the separating step, the metal core body and the final product, the polyimide seamless tubular article, are excellent in separability.

Due to the effect of the coating layer composed of the above-mentioned organoalkoxide compound, starting from the step of applying the polyimide precursor in the form of a solution, the step of keeping the core in the core until a seamless tubular product is obtained is performed in one step. It can be manufactured. Further, since the surface of the metal core is covered with the coating layer made of the organoalkoxide compound having a uniform thickness, appearance defects such as protrusions do not occur in the seamless tubular product of the final product.
Furthermore, the coating layer made of the organoalkoxide compound is used for thermal expansion of the metal core in the heating step (including solvent drying of the polyimide precursor solution and imide conversion reaction), and subsequent cooling of the metal core. It is possible to prevent the occurrence of cracks and the like in the coating layer made of an organoalkoxide compound due to shrinkage. The metal core body coated with the coating layer made of the organoalkoxide compound can be repeatedly used in the coating step, the solidifying step, and the separating step.

(Organoalkoxide Compound) The organoalkoxide compound which is a constituent of the coating layer comprising the organoalkoxide compound in the present invention is
It is an organoalkoxide compound of an inorganic element represented by the following general formula (1).

[0029]

[Chemical 1]

In the general formula (1), M is a Si atom, A
1 atom and Zn atom are represented. R is a methyl group (-CH _3),
Represents an ethyl group (-C ₂ H _5). In the general formula (1),
M is preferably a Si atom. The R is preferably a methyl group (-CH _3).

Specific examples of the above-mentioned organoalkoxide compounds include the following ceramic ceramics G90 and G manufactured by Nippa Institute.
92-5 can be mentioned. In G92-5, m represents 1 and n represents 2.

[0032]

[Chemical 2]

(Surface Roughness) Since the surface roughness of the coating layer made of the organoalkoxide compound is transferred to the back surface of the seamless tubular product of the final product, it can be adapted to the purpose of use of the seamless tubular product. . The surface roughness of the coating layer composed of the organoalkoxide compound applied to the metal core is the arithmetic average roughness Ra.
0.5-1.5 μm is preferable, and 0.6-1.2 μm
Is more preferable, and 0.7 to 1.1 μm is still more preferable.

When the surface roughness Ra is more than 1.5 μm, the surface roughness of the polyimide seamless tubular product may be so rough that the surface roughness required for the surface layer of the bias roll described later may not be obtained. is there. On the other hand, the surface roughness R
When a is less than 0.5 μm, the generated gas component may accumulate inside the polyimide resin film, and the film of the seamless tubular product may be formed in a convex shape.

(Method for applying coating layer made of organoalkoxide compound) Examples of the method for applying the coating liquid made of the organoalkoxide compound to the metal core include spray coating, dipping treatment and roll coating.

(Thickness of Coating Layer Made of Organoalkoxide Compound) The thickness of the coating layer made of the organoalkoxide compound is 0.1 μm to 5 μm.
Is more preferable, 0.5 μm to 3 μm is more preferable, and 0.8 μm to 2 μm is further preferable. If the thickness is less than 0.1 μm, unevenness of the film thickness may not be obtained, and coating unevenness may occur. If the thickness exceeds 5 μm, the coating film may be dripping or the like. There may occur a problem that the thickness is not uniform.

<Polyimide Precursor Solution> Examples of the polyimide precursor solution usable in the present invention include those obtained by reacting an aromatic tetracarboxylic acid component and an aromatic diamine component in an organic polar solvent. Examples of the aromatic tetracarboxylic acid component include pyromellitic acid, naphthalene-1,4,5,8-tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid, 2,3,5,6.
-Biphenyltetracarboxylic acid, 2,2 ', 3,3'-
Biphenyltetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 3,3', 4,4'-diphenylethertetracarboxylic acid, 3,3 ', 4,4'
-Benzophenone tetracarboxylic acid, 3,3 ', 4,
4'-diphenylsulfone tetracarboxylic acid, 3,
3 ', 4,4'-azobenzenetetracarboxylic acid, bis (2,3-dicarboxyphenyl) methane, bis (3,3
4-dicarboxyphenyl) methane, β, β-bis (3,4-dicarboxyphenyl) propane, β, β-
Examples thereof include bis (3,4-dicarboxyphenyl) hexafluoropropane, and a mixture of these tetracarboxylic acids may be used.

The aromatic diamine component is not particularly limited, and is m-phenyldiamine, p-phenyldiamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diaminochlorobenzene, m-xylyl. Diamine, p-xylylenediamine, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2,6
-Diaminonaphthalene, 2,4'-diaminonaphthalebiphenyl, benzidine, 3,3-dimethylbenzidine,
3,3'-dimethoxybenzidine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether (oxy-p, p'-dianiline; ODA),
4,4'-diaminodiphenyl sulfide, 3,3'-
Diaminobenzophenone, 4,4'-diaminophenyl sulfone, 4,4'-diaminoazobenzene, 4,4 '
-Diaminodiphenylmethane, β, β-bis (4-aminephenyl) propane and the like.

Examples of the organic polar solvent include N-
Methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide and the like can be mentioned. These organic polar solvents may be mixed with phenols such as cresol, phenol and xylenol, and hydrocarbons such as hexane, benzene and toluene, if necessary. The polar solvent may be used alone or as a mixture of two or more kinds.

(Conducting Agent of Polyimide Precursor Solution) The polyimide seamless tubular product as the final product may be required to have conductivity depending on the purpose of use, and in that case, a conducting agent is added to the polyimide precursor solution. By doing so, conductivity can be imparted to the final product polyimide seamless tubular article. Examples of the conductive agent include electron conductive conductive agents and ion conductive conductive agents.

As the electron conductive type conductive agent, carbon black, graphite, aluminum, nickel,
Metals or alloys such as copper alloys; metal oxides such as tin oxide, zinc oxide, kalim titanate, tin oxide-indium oxide, and tin oxide-antimony oxide composite oxides.
Examples of the ion-conducting conductive agent include sulfonates, ammonia salts, and various surfactants such as cation-based, anion-based, and nonionic-based surfactants.

Further, as a means for imparting conductivity to the polyimide seamless tubular product of the final product, there is a method of blending a conductive polymer with the polyimide precursor solution. As the conductive polymer, for example, a copolymer of a (meth) acrylate whose carboxyl group binds a quaternary ammonium salt group and another compound (for example, styrene); a maleimide which binds a quaternary ammonium salt group,
Polymers that bind quaternary ammonium salt groups such as copolymers with methacrylates; polymers that bind alkali metal salts of sulfonic acids such as sodium polysulfonate; polyethylene oxide, polyethylene glycol-based polyamide copolymers, polyethylene oxid-epichlorohydrin Copolymers polyether amide imides, polymers having a hydrophilic unit of at least an alkyl oxide bonded in the molecular chain such as block-type polymers having a polyether as a main segment, and the like, and further, an electron-conducting conductive agent Examples thereof include polyaniline, polythiophene, polyacetylene, polypyrrole, and polyphenylene vinylene. These conductive polymers can be used in a dedoped state or a doped state. The above-mentioned resistance value can be stably obtained by using one kind or a combination of two or more kinds of the above-mentioned conductive agent or conductive polymer and the surfactant.

The viscosity of the polyimide precursor solution is 50.
It is preferably in the range of up to 1000 poise, and 100
More preferably, it is in the range of up to 200 poise. When the viscosity of the polyimide precursor solution is in the range of 50 to 1000 poise, it is convenient and preferable for forming a uniform film thickness.

(Method of Applying Polyimide Precursor Solution) As a method of applying the polyimide precursor solution to a substantially uniform thickness on the surface of the metal core covered with the coating layer made of the organoalkoxide compound, Although not limited, the following coating method is preferable in that the polyimide precursor solution can be coated efficiently and reasonably in a substantially uniform thickness. A method for applying such a preferable polyimide precursor solution will be described with reference to the drawings. Figure 2 (A) shows
It is the schematic which showed the method of apply | coating the polyimide precursor solution in this invention to the metal core body covered by the coating layer which consists of an organoalkoxide compound. On the other hand, FIG.
2B is a cross-sectional view of a coated portion of the metal core body covered with the coating layer made of the organoalkoxide compound shown in FIG. 2A. In FIG. 2, 21 is a metal core covered with a coating layer composed of the organoalkoxide compound, 22 is a plate,
Reference numeral 23 is a container, and 24 is a polyimide precursor solution applied to the surface of the metal core body 21 covered with a coating layer made of an organoalkoxide compound.

While rotating the metal core 21 in the direction of arrow A at a constant speed, a predetermined amount of the polyimide precursor solution is dropped from the container 23 containing the polyimide precursor solution 24 on the surface of the metal core 21. Then, it is a method of applying this while smoothing it with the plate 22 that is in contact with the surface of the metal core 21, and as a result, the uniformly smoothed polyimide precursor solution 24 is a coating layer composed of an organoalkoxide compound. It is applied to the surface of the covered metal core 21. In the present invention, the method of applying the polyimide precursor solution to the metal core covered with the coating layer made of the organoalkoxide compound is not limited to this method, and other methods such as dip coating may be used. .

<Seamless tubular product> The seamless tubular product containing polyimide as a main component of the present invention is a polyimide precursor coated on the outer surface of a metal core covered with a coating layer made of an organoalkoxide compound as described above. A solid solution in which the body solution is heated to carry out an imide conversion reaction;
The polyimide obtained by the solidification step can be manufactured by a separation step of separating the polyimide from the metal core body.

The polyimide seamless tubular article of the present invention will be described below with reference to the drawings. FIG. 3A is a longitudinal sectional view of the polyimide seamless tubular article of the present invention. On the other hand, FIG. 3B is a cross-sectional view taken along the line aa of the polyimide seamless tubular product shown in FIG. In FIG. 3, 3
0 indicates the polyimide seamless tubular article of the present invention. The polyimide seamless tubular article 30 is composed of a polyimide layer 31.

(Surface Roughness of the Surface of the Seamless Tubular Material) The surface roughness of the surface of the seamless tubular material has a ten-point average roughness Rz of 0.01 to 10 in terms of toner cleaning property and paper releasability. The thickness is preferably in the range of 10 μm, and 0.
The range of 1 to 5 μm is more preferable.

(Inner Diameter of Seamless Tubular Material) The inner diameter of the seamless tubular material is determined according to the outer diameter of the metal core. The inner diameter of the seamless tubular product is 10 mm to 1
It is preferably in the range of 000 mm, and 15 mm to 6
The range of 00 mm is more preferable. When the inner diameter of the seamless tubular product is in the range of 10 mm to 1000 mm, it is preferable for forming a uniform film thickness.

(Thickness of Seamless Tubular Material) The thickness of the seamless tubular material is preferably in the range of 10 to 100 μm, more preferably in the range of 20 to 80 μm. The thickness of the seamless tubular product is 10 to 100 μm.
The range of m is preferable for forming a uniform film thickness.

The polyimide seamless tubular article of the present invention is
For example, it can be used as a surface coating material for the bias roll having the structure shown in FIG. FIG. 4 is a sectional view of a bias roll using the polyimide seamless tubular article of the present invention. FIG. 4 shows the elastic layer 42 on the surface of the metal shaft 41.
And the surface of the elastic layer 42 is covered with the polyimide seamless tubular article 43 according to the present invention.

<Image forming apparatus> When the bias roll using the polyimide seamless tubular article of the present invention as the surface coating material is used in the image forming apparatus shown in FIG. 5, the polyimide film is a material having excellent abrasion resistance. It can be used as a bias roll that is stable over time. FIG. 5 is a schematic view showing an example of an image forming apparatus including a bias roll using the polyimide seamless tubular article of the present invention as a surface coating material.

In FIG. 5, the surface of an electrophotographic photosensitive member 51 formed by coating a photosensitive material on an aluminum pipe is uniformly charged by a charger 52, and then an image emitted from a writing device 54a. Scanning exposure 54b according to information
Thus, an electrostatic latent image is formed on the surface of the photoconductor. This electrostatic latent image is developed and visualized by the developing device 55K of the developing devices 55 corresponding to the color information of the electrostatic latent image formed this time.

The visualized toner image is transferred from the electrophotographic photosensitive member 51 to the surface of the intermediate transfer member 60 in the transfer region P ₁ where the electrophotographic photosensitive member 51 and the intermediate transfer member 60 are in contact with each other from a power source (not shown). It is transferred by applying a voltage between the drum and the photoconductor. The surface of the photoconductor after the transfer is irradiated with the light from the charge eliminating lamp 58 to be eliminated,
The toner remaining on the surface of the photoconductor is removed by the cleaning device 53.

The above steps are repeated a plurality of times, and developing devices 55K and 5K each having a developing agent of a different color according to the image information.
Developed and visualized by 5Y, 55M, 55C, and transferred and laminated sequentially from the surface of the photoconductor to the intermediate transfer drum 60.
A plurality of toner images are laminated on the surface of the intermediate transfer drum.

The color toner image laminated on the surface of the intermediate transfer drum 60 is conveyed by the sheet conveying roll 59, and the contact area between the intermediate transfer body 60 and the recording material 61 located between the bias roll 56. At the time, the voltage is applied between the intermediate transfer drum 60 and the bias roll 56, and the image is collectively transferred from the surface of the intermediate transfer drum to the recording material. A peeling charger may be used instead of the transfer roll. Further, a peeling charger may be provided in the vicinity of the transfer area together with the bias roll. The toner images collectively transferred to the surface of the recording material 61 are conveyed to the fixing device 57 and fixed by the fixing device 57. In addition, in FIG. 5, the intermediate transfer body 60 is shown as a drum type, but a belt type is also applicable.

Although the description has been centered on the seamless tubular product containing polyimide as a main component, which is a typical heat-resistant resin composition, the seamless tubular product made of a heat-resistant resin composition other than polyimide is also described above. What is obtained by the method for producing a seamless tubular article is a seamless tubular article having a friction coefficient on the back surface smaller than the friction coefficient on the surface and having a high degree of accuracy, and the same effect as that of the polyimide seamless tubular article can be obtained.

[0058]

EXAMPLES The present invention will be described in more detail with reference to the following examples.
Specifically, the present invention is only limited to these examples.
It is not limited. (Example 1) As a metal core, arithmetic mean roughness Ra1.
7μm, outer diameter 20.2mm, thickness 1mm aluminum tube
Ceramica G92-5 (Al₂O₃-S
iO ₂Of the organoalkoxide compound containing
Make the mass ratio of the main agent liquid A and the curing agent liquid B to be 3: 1.
Mix and ripen at 40 ° C for 3 hours.
A coating solution was obtained. Remove the coating surface of the metal core
After greasing, the coating liquid of G92-5 is applied to the metal core.
Dip, apply evenly, dry at room temperature, then at 150 ° C
It was dried for 5 minutes.

Further, ceramic plate G90 (Si
Main agent A solution of the organo alkoxide compound) to the O ₂ as a main component and a curing agent solution B in a weight ratio of 3: 1 and were mixed so that, perform aging for 3 hours at 40 ° C., the coating liquid G90 Obtained. The obtained coating liquid of G90 is dipped on the metal core body coated with the coating liquid of G92-5 and uniformly coated, and dried at room temperature.
Heating was performed at 0 ° C. for 30 minutes to obtain a metal core body covered with a coating layer made of an organoalkoxide compound. The thickness of the coating layer made of an organoalkoxide compound is 1 μm, and the arithmetic average roughness Ra is 1.5 μm.
It was m.

A metal core covered with a coating layer made of the above-mentioned organoalkoxide compound, polyimide varnish R manufactured by Ube Industries (solid content 18% by mass, viscosity 150 poise), SB4 manufactured by Degussa Japan Co., Ltd. By mass part addition and dispersion by Dynamill, a polyimide precursor solution having a viscosity of 150 poise was obtained.

The resulting polyimide precursor solution was dropped while the container 23 was moved at a constant speed in the axial direction of the metal core as shown in FIG. The polyimide precursor solution easily became a solution coating film of the polyimide precursor.

Then, the metal core body on which the coating film of the polyimide precursor solution is formed is dried at 80 ° C. for 30 minutes,
By heating to 300 ° C. and heating at 300 ° C. for 2 hours, the solvent was removed and imidization was performed. Finally, after cooling to room temperature, the polyimide seamless tubular product was removed from the metal core. The obtained polyimide seamless tubular product had a thickness of 40 μm, a volume resistance value of 6.3: logΩ as measured at an applied voltage of 100 V, and a ten-point average roughness Rz of the surface of 0.6 μm. The polyimide seamless tubular article could be easily removed from the core even though the surface of the metal core was not coated with a release agent. The obtained metal core covered with the coating layer composed of the organoalkoxide compound was reusable up to 100 times.

(Example 2) As a metal core, an aluminum tube having an arithmetic mean roughness Ra of 1.7 µm, an outer diameter of 20.2 mm and a thickness of 1 mm was used, and G92 was prepared in the same manner as in Example 1.
The coating liquid of -5 and the coating liquid of G90 were prepared and applied to obtain a metal core covered with a coating layer made of an organoalkoxide compound. The thickness of the coating layer made of an organoalkoxide compound is
It was 1 μm, and the arithmetic average roughness Ra was 0.5 μm.

A polyimide precursor solution was applied to the metal core covered with the coating layer composed of the organoalkoxide compound in the same manner as in Example 1. At this time, the polyimide precursor solution easily became a coating film of the polyimide precursor solution. Then, a polyimide seamless tubular product was obtained by the same method as in Example 1. The obtained polyimide seamless tubular article has a volume resistance value of the polyimide tubular article of 6.2: log when measured at an applied voltage of 100V.
Ω, the thickness was 40 μm, and the ten-point average roughness Rz of the surface was 0.2 μm. Further, the polyimide seamless tubular article could be easily removed from the core body even though the surface of the metal core body was not subjected to a treatment such as coating with a release agent. Further, the metal core body coated with the organoalkoxide compound could be repeatedly used up to 100 times.

(Example 3) As a metal core, an aluminum tube having an arithmetic mean roughness Ra of 1.0 µm, an outer diameter of 20.2 mm and a thickness of 1 mm was used, and G92 was prepared in the same manner as in Example 1.
The coating liquid of -5 and the coating liquid of G90 were prepared and applied to obtain a metal core covered with a coating layer made of an organoalkoxide compound. The thickness of the coating layer made of an organoalkoxide compound is
It was 0.8 μm, and the arithmetic mean roughness Ra was 0.8 μm.

Using the metal alkoxide compound-coated metal core described above, a solution of the polyimide precursor was applied in the same manner as in Example 1. At this time, the solution of the polyimide precursor was easily prepared. A coating film of the solution was obtained. Then, a polyimide seamless tubular product was obtained by the same method as in Example 1. The volume resistance value of the obtained polyimide seamless tubular product was 6.2: logΩ, the thickness was 40 μm, and the ten-point average roughness Rz of the surface was 0.3 μm as measured at an applied voltage of 100 V. In addition, although the surface of the core was not subjected to treatment such as coating with a release agent,
The polyimide seamless tubular article could be easily removed from the core. Further, the metal core body coated with the organoalkoxide compound could be repeatedly used up to 100 times.

(Comparative Example 1) As a metal core, arithmetic mean roughness Ra is 1.0 μm, outer diameter is 20.2 mm, thickness is 1 mm.
After degreasing the coated surface of the metal core using the aluminum tube of, the silicon-based mold release agent KS- manufactured by Shin-Etsu Chemical Co., Ltd.
700 (nonvolatile content 14.4% by mass) was applied, dried at room temperature, and then dried at 150 ° C. for 5 minutes. The polyimide precursor solution was applied in the same manner as in Example 1, but cissing occurred and the polyimide precursor coating could not be formed.

(Comparative Example 2) A metal core body having an arithmetic average roughness Ra of 1.0 μm, an outer diameter of 20.2 mm and a thickness of 1 mm.
After degreasing the coated surface of the metal core using the aluminum tube of, the silicon-based mold release agent KS- manufactured by Shin-Etsu Chemical Co., Ltd.
700 was applied, dried at room temperature, and then dried at 350 ° C. for 30 minutes. The polyimide precursor solution was applied in the same manner as in Example 1. The cissing phenomenon that occurred in Comparative Example 1 did not occur, and a film of the polyimide precursor could be formed.

Then, after drying at 80 ° C. for 30 minutes, 300
By heating to 0 ° C. for 2 hours, the solvent was removed and imidization was performed. Finally, after cooling to room temperature, the polyimide tubular body was removed from the metal core body. However, when the coating of the polyimide precursor is repeatedly formed on this metal core, and the step of removing the polyimide tubular material is performed, the metal core and the polyimide tubular material are firmly adhered at the third time, It can no longer be separated as a seamless tubular object.

(Comparative Example 3) As a metal core body, an aluminum tube having a arithmetic mean roughness Ra of 0.2 μm or less, an outer diameter of 20.2 mm and a thickness of 1 mm, which was mirror-finished by buffing, was used.
After degreasing the coated surface of the metal core, a silicone release agent KS-700 manufactured by Shin-Etsu Chemical Co., Ltd. was applied, dried at room temperature, and then dried at 350 ° C. for 30 minutes. The polyimide precursor solution was applied in the same manner as in Example 1. However, in the same manner as in Example 1, the gas component generated in the process of removing the solvent and performing imidization caused unevenness on the surface of the tubular product, and a normal polyimide seamless tubular product could not be obtained. .

(Comparative Example 4) A metal core body having an arithmetic mean roughness Ra of 2.5 μm, an outer diameter of 20.2 mm and a thickness of 1 mm.
The surface of the metal core was coated with polytetrafluoroethylene resin using the stainless steel of. A solution of a polyimide precursor was applied to this in the same manner as in Example 1. Next, after drying at 80 ° C. for 30 minutes, by heating at 300 ° C. for 2 hours, the solvent is removed and imidization is performed,
Finally, after cooling to room temperature, I tried to remove the polyimide seamless tubular product from the core, but the polyimide coating on the surface of the core had many locally swollen parts to obtain a normal polyimide seamless tubular product. I couldn't.

[0072]

INDUSTRIAL APPLICABILITY The present invention uses a method for producing a seamless tubular article having a high product yield and a low cost, a highly accurate seamless tubular article obtained by the production method, and the obtained seamless tubular article. The image forming apparatus can be provided.

[0073]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a metal core body on the surface of which a coating layer made of an organoalkoxide compound of the present invention and a coating layer made of a polyimide precursor are formed.

FIG. 2 (A) is a schematic view showing a method of applying the polyimide precursor solution of the present invention to a metal core body covered with a coating layer made of an organoalkoxide compound. (B) is a cross-sectional view of a coated portion of the metal core body covered with the coating layer made of the organoalkoxide compound according to (A).

FIG. 3A is a cross-sectional view of the polyimide seamless tubular article of the present invention as seen in the longitudinal direction. (B) is
It is an aa sectional view of the polyimide seamless tubular article described in (A).

FIG. 4 is a sectional view of a bias roll using the polyimide seamless tubular article of the present invention.

FIG. 5 is a schematic view showing an example of a full-color image forming apparatus using the polyimide seamless tubular article of the present invention as a bias roll.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Metal core 12 Coating layer 13 consisting of organoalkoxide compound 13 Coating layer 21 Metal core 22 covered with coating layer consisting of organoalkoxide compound 22 Plate 23 Container 24 Polyimide precursor coated on the surface of metal core 21 Body solution 30 Polyimide seamless tubular material 31 Polyimide layer 41 Metal shaft 42 Elastic layer 43 Polyimide seamless tubular material 51 Photoreceptor (image carrier) 52 Charging device 53 Cleaning device 54a Image writing device 54b Scanning exposure 55 (K, Y, M , C) Black, yellow, magenta, cyan developing device 56 Bias roll 57 Fixing device 58 Electrification lamp 59 Paper transport roller 60 Intermediate transfer drum (intermediate transfer member) 61 Recording material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takeshi Kawai             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Hideaki Kago             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. F-term (reference) 2H200 FA13 JA02 JA25 JB10 MA04                       MA20                 4F205 AA40 AB13 AC05 AG08 AH04                       AJ02 AJ07 AJ09 AR13 GA06                       GB01 GC01 GF02 GN01 GN28

Claims (8)

[Claims] 1. A method for producing a seamless tubular product made of a heat-resistant resin composition, comprising applying a liquid heat-resistant resin composition to the surface of a metal core body covered with a coating layer made of an organoalkoxide compound. And a solidification step of solidifying or curing the liquid heat-resistant resin composition applied to the surface of the metal core, the solidified or cured heat-resistant resin composition, the metal core And a separation step of separating from the seamless tubular article. 2. The applying step is a step of applying the polyimide precursor solution as the liquid heat-resistant resin composition to a uniform thickness on the surface of the metal core covered with the coating layer, The method for producing a seamless tubular article according to claim 1, wherein the solidifying step is a step of heating the applied polyimide precursor solution to cause an imide conversion reaction. 3. The method for producing a seamless tubular article according to claim 2, wherein a conductive agent is dispersed in the polyimide precursor solution. 4. The coating layer made of the organoalkoxide compound is a coating layer obtained by baking the metal core body with a coating solution of the organoalkoxide compound and heating the metal core body. 4. The method for producing a seamless tubular article according to any one of 3 to 3. 5. The application step comprises rotating the metal core and moving a fixed amount of liquid heat-resistant resin in the axial direction of the metal core covered with the coating layer at a constant speed. The method for producing a seamless tubular article according to any one of claims 1 to 4, which is a step of applying the composition to the surface of the metal core. 6. A seamless tubular article produced by the method for producing a seamless tubular article according to claim 1. 7. The arithmetic average roughness Ra of the coating layer made of the organoalkoxide compound is 0.5 to 1.
The seamless tubular article according to claim 6, which has a thickness of 5 μm. 8. An image forming apparatus including a roll-type transfer device, wherein the seamless tubular article according to claim 6 or 7 is used as a bias roll of the transfer device.