JPH10296761A - Manufacture of seamless rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a seamless rotor which can be easily released from a mold by releasing a formed film from an inner surface of a cylinder, covering a flexible cylinder made of metal with it, and thermosetting it. SOLUTION: First, an intermediate film is manufactured by coating an interior of a rigid cylinder having no flexibility with solution of thermosetting film forming resin, heating it to evaporate solvent, and then releasing a film from an inner surface of the cylinder. Then, after unnecessary parts of bottom and end of the film are cut, it is covered with a flexible cylinder 5 made of metal. The cylinder 5 covered with the film is then heated to a predetermined temperature so that curing reaction of the thermosetting film forming resin is advanced, the film is hence shrunk to form a seamless rotor 6. The formed rotor 6 can be easily released from the cylinder 5 of metal and removed by suitably deforming or recessing the cylinder 5.

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 rotary member, that is, a seamless belt or a seamless film used for a photosensitive member, a transfer belt, a fixing belt and the like in an electrophotographic apparatus such as a copying machine and a printer.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, a rotating body made of metal, various plastics, or rubber is used for a photosensitive member, a transfer belt, a fixing belt, and the like. In order to reduce the size or increase the performance of the device, it is preferable that these rotating bodies be deformable to some extent. However, as these rotating bodies, a rotating body made of a thin plastic film is used. Have been. At that time, if there is a seam in the rotating body, a defect due to the seam occurs in the output image. Therefore, it is preferable that there is no seam.

[0003] As a method for producing a seamless rotary body, for example, Japanese Patent Application Laid-Open No. Sho 60-170862 discloses a method of forming the inner peripheral surface of a mold by a rotational molding method.
JP-A-202513 discloses a method of forming a film by melt-extrusion of a resin in a ring shape, and JP-A-6-222695 discloses a method of applying a resin solution to the outer surface of a cylindrical mold to a constant thickness by dipping, forming a film by heating. It describes how to pull out the mold.

[0004]

As the material of the rotating body, a thermosetting resin represented by polyimide is preferable, particularly from the viewpoint of strength. However, the method of extruding the thermosetting resin in a ring shape has a problem in surface smoothness. Therefore, it is difficult to use it for electrophotographic equipment, and it is difficult to produce a rotating body having a large diameter. Further, in the method of forming a film on the inner surface of the mold, a strong shrinkage force acts upon the thermosetting of the thermosetting resin, and the film is detached from the mold in an irregular shape, so that the shape tends to be distorted. On the other hand, in the method of forming a film on the outer surface of the mold, since the thermosetting resin firmly adheres to the mold due to a strong shrinkage force at the time of thermosetting, when the formed seamless rotary body is smoothly peeled from the mold. In addition, there was a problem that the number of work steps required for peeling increased.

There is also a method in which a thermosetting resin is formed on the inner surface of a mold, only the solvent is dried, the formed film is peeled off, and then thermosetting is performed on the outer surface of another mold. Since the film is firmly adhered to the mold due to the contraction force, it is difficult to peel the film.

Accordingly, an object of the present invention is to provide a method for forming a seamless rotary member made of a thermosetting resin, which method can easily peel off the rotary member from a mold.

[0007]

According to the present invention, there is provided a method for producing a seamless rotary body, comprising applying a solution of a thermosetting film-forming resin to an inner surface of a rigid cylindrical body, heating the solvent, and evaporating the solvent.
By peeling the formed film from the inner surface of the cylindrical body and covering it with a metal flexible cylindrical body and thermosetting,
A seamless rotary body made of a thermosetting film is obtained. Hereinafter, the seamless film before the heat curing is referred to as “intermediate film”.

In the present invention, when the intermediate film is thermally cured, the metal flexible cylinder covered with the intermediate film may be fitted to another rigid cylinder. Further, after applying the solution of the thermosetting film-forming resin to the inner surface of the rigid cylindrical body, when heating, the cylindrical body may be rotated and centrifugal force may be applied to improve the uniformity of the film when heating. .

In order to prevent the intermediate film from adhering to the inner surface of the rigid cylinder, a mold release agent is applied to the inner surface of the cylinder in advance, or a mold release resin layer is formed beforehand. Is also good. If the uniformity of the film is thereby impaired, a leveling agent may be added to the film-forming resin solution. Further, a release agent may be applied in advance also to the surface of the flexible metal cylinder covered with the intermediate film. Further, the surface of the metal flexible cylinder on which the intermediate film is covered may be roughened. Furthermore, when applying the solution of the thermosetting film-forming resin to the inner surface of the rigid cylindrical body, the solution may be heated to 50 to 200 ° C. for application.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, examples of the thermosetting film-forming resin include polyimide, polyamideimide, polybenzimidazole, phthalic polyester, and polyurethane. Among them, polyimide is particularly preferable in view of strength and dimensional stability. In the present invention, when the seamless rotary member is used as an electrical component, a conductive substance may be dispersed in the solution of the thermosetting film-forming resin.

First, an intermediate film is produced using a solution of the above-mentioned thermosetting film-forming resin. For example, a method for producing an intermediate film is as follows. A method is used in which a solution of the forming resin is put in, applied to the inner surface of the cylinder, heated to evaporate the solvent, and then the film is peeled off from the inner surface of the cylinder. FIG. 1 shows an example of this and is a cross-sectional view of a rigid cylindrical body. When the resin solution is put into the rigid cylinder 2 and the solution flows down from the open end, the resin solution is applied to the entire inside of the rigid cylinder 2 including the inclined surface 3 to form a coating. When this coating is heated to evaporate the solvent, a seamless intermediate film 1 is formed. A raised portion 4 of the resin solution is formed at the apex of the inclined surface 3, but the film can be easily peeled from the inner surface of the cylinder by pulling the raised portion 4 of the resin after evaporating the solvent.

When a solution of a thermosetting film-forming resin is applied to the inner surface of a cylinder and applied, the lower the viscosity of the solution, the better the flowability, and the higher the uniformity of the film thickness and the like. However, the above-mentioned solutions of the thermosetting film-forming resin all have considerably high viscosities and may not easily flow. Therefore, a method of heating the solution can be adopted to reduce the viscosity of the solution. In that case, the heating temperature of the solution depends on the boiling point of the solvent used, but it is 50 to 20.
A range of 0 ° C. is preferred. By heating the solution, viscosity decreases, fluidity increases, and uniformity improves,
Since the evaporation of the solvent is promoted, there is also an effect that the heating and drying time after application to the inner surface of the rigid cylindrical body can be reduced.
Furthermore, if water is mixed as an impurity in the solution, a dent defect may occur in the seamless rotary member that is formed, but even in such a case, if the solution is heated, the water is removed. No defects occur. The heating temperature at this time is preferably in the range of 100 to 200 ° C.

When the intermediate film is in close contact with the inner surface of the rigid cylindrical body, a release agent may be applied to the inner surface in advance, or a release resin layer may be formed. As the release agent, various commercially available products of silicone oil or rubber can be used. Considering the durability of the release agent, a thermosetting type is preferable. Further, the releasable resin layer can be formed by powder coating lining using a fluororesin or a polyethylene resin.

When a film is formed, the resin solution is easily repelled by the water repellency and oil repellency of the release agent or the releasable resin layer, and if the uniformity is impaired, the thermosetting film-forming resin may be used. A leveling agent may be added to the above solution. The leveling agent is an additive that lowers the surface energy of the solution to prevent repelling, and various types of silicone oils and surfactants can be used. The addition amount is preferably in the range of 0.001 to 1% of the resin component.

When the resin solution is heated to evaporate the solvent, it is preferable to rotate the rigid cylinder 2 horizontally. In that case, the uniformity of the film thickness can be improved by the action of the centrifugal force. Rotation speed is 100-5000
The rpm range is preferred.

The intermediate film peeled off from the inner surface of the cylinder,
Since it is a film in which the solvent is only evaporated, it does not have the original strength, but has strength enough to maintain its shape.

Next, unnecessary portions at the bottom and the end of the intermediate film are cut, and the intermediate film is covered with a flexible metal cylinder. In the present invention, the reason why the metal flexible cylinder is used is that the intermediate film can be easily peeled off from the mold even when the intermediate film is heat-cured on the outer surface of the mold. FIG. 2 is a perspective view of a metal flexible cylinder, in which an intermediate film is covered with a metal flexible cylinder 5 and a seamless rotary body 6 is provided.
Shows a state in which is formed. The outer diameter of the metal flexible cylinder determines the inner diameter of the target seamless rotary body 6, and is 2 to 1 times smaller than the inner diameter of the rigid cylinder.
It is preferable that it is smaller by about 0 mm. In addition, since the surface shape of the metal flexible cylindrical body 5 is transferred to the inner surface of the seamless rotary member, there must be no seams, protrusions, scratches, defects, and the like. When it is desired to roughen the inner surface of the seamless rotary member 6 in order to increase the frictional resistance or the like, the surface of the metal flexible cylindrical member 5 is matted, and sandblasting, honing, and etching are performed. The surface may be roughened by a method such as a grinding wheel treatment. By roughening, an air layer is formed between the metal-made flexible cylindrical body and the seamless rotary body, so that there is also an effect that the two hardly adhere to each other. Examples of the flexible cylinder made of metal include a seamless belt made of nickel, stainless steel, or the like, and the thickness thereof is preferably about 0.05 to 0.5 mm. The metal-made flexible cylinder covered with the intermediate film is then heated at a predetermined temperature, whereby the curing reaction of the thermosetting film-forming resin proceeds, and the film shrinks to form a seamless rotary body. The formed seamless rotating body 6 can be easily peeled off from the metal flexible cylinder 5 by appropriately deforming or denting the metal flexible cylinder 5. In order to further ensure peeling, it is preferable to apply a release agent in advance also to the surface of the flexible metal cylinder. Furthermore, it is preferable to use a metal having a roughened surface as a flexible cylinder made of metal.

If the metal flexible cylinder itself deforms during heating, it is fitted to another rigid cylinder having no further flexibility (for example, a metal pipe or glass tube made of stainless steel or the like). To prevent deformation. The outer diameter is preferably smaller by about 0.1 to 5 mm than the inner diameter of the flexible metal cylinder. After heating, the metal flexible cylinder is removed from the other rigid cylinders, deformed appropriately and the film is peeled off, so that the desired seamless rotary body can be obtained. The obtained seamless rotary body is further subjected to slit processing, punching hole punching processing, tape winding processing, and the like as necessary.

When the seamless rotary member is applied to an electrophotographic photosensitive member, a contact charging belt for the photosensitive member, or a transfer belt for transferring toner from the photosensitive member to paper, it is necessary to impart conductivity. There is a method for dispersing a conductive substance in a resin solution, for example. Examples of the conductive substance include powders of conductive carbon, metal powder, titanium black, conductive zinc oxide, copper oxide, tin oxide, tin oxide / antimony, and tin oxide / indium. As another method for imparting conductivity to the seamless rotary member, there is a method of performing a conductive treatment on the surface. As the conductive treatment, formation of a metal film by vapor deposition or the like, application of a conductive paint in which the conductive substance is dispersed, or the like can be employed.

Using a seamless rotating body provided with conductivity as a substrate, an undercoat layer is formed as necessary, and a charge generation layer (CGL) and a charge transport layer (CTL) or a single-layer photosensitive layer is formed thereon. This forms an electrophotographic photosensitive member. When a seamless rotating body is used as a base, the electrophotographic photosensitive member is flexible and can be freely deformed. For example, a flat portion is used in a charging portion, a curved surface portion is used in a transfer portion, and the like. The effect of being able to be transformed into a curvature is produced.

[0021]

【Example】

(Example 1) Inner diameter 121 mmφ × 360 mm length × 2.0
A SUS304 rigid cylindrical body having a thickness of mm was prepared, and a cylindrical lid having a height of 20 mm and having a height of 20 mm was attached to one end of the rigid cylindrical body. A baking mold release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the inner surface of the mold, and 300
Heated at 0 ° C. for 1 hour. On the other hand, N-methylpyrrolidone solution of polyamic acid (trade name: U Varnish, manufactured by Ube Industries)
0.01% of a silicone leveling agent (trade name: KP322, manufactured by Shin-Etsu Chemical Co., Ltd.) and a viscosity of 1600 mP
The solution was diluted with dioxane to a.sec. Dioxane is used for adjusting the drying property and is a poor solvent for the polyamic acid, but it is possible to dilute the solution. The resin solution was placed in the mold, and then the mold was inverted to drain the resin solution. After 5 minutes, the solvent was dried by blowing hot air at 150 ° C. while rotating the mold horizontally at 800 rpm.

After drying for 1 hour, the top of the convex portion at the end was pinched and the film was pulled to peel off the intermediate film. After cutting off the ends and the like, the intermediate film was fitted into a nickel-made flexible cylindrical body having an outer diameter of 120 mmφ and a thickness of 0.1 mm. This cylindrical body is a seamless body made by electroforming,
The surface roughness was a mirror surface with Ra = 0.03 μm. Further, this was fitted into a SUS cylindrical body having an outer diameter of 119 mmφ and a thickness of 3 mm. Next, the resin was cured by heating at 350 ° C. for 1 hour. Thereafter, the flexible cylinder was extracted from the SUS cylinder, and the cured film was peeled off by appropriately bending or denting. Cut both ends to 120mmφ, 3
A seamless rotary member having a length of 40 mm and a thickness of 50 μm was obtained. This seamless rotary body had a mirror-finished inner surface and excellent dimensional stability, and could be used as a transport belt for an electrophotographic printer.

(Comparative Example 1) The intermediate film peeled from the mold was fitted into a SUS cylindrical body having an outer diameter of 120 mmφ and a thickness of 3 mm, and heated at 350 ° C. for 1 hour to cure the resin in the same manner as in Example 1. Was. Thereafter, an effort was made to peel off the hardened seamless rotary member, but peeling was difficult because of the strong shrinkage of the resin.

(Example 2) Carbon black (trade name: R330, manufactured by Cabot) having a solid content of 15% by weight was added to the polyamic acid solution of Example 1 and dispersed by a ball mill. Next, the dispersion was placed in the cylindrical mold used in Example 1, and thereafter, a seamless rotary member was obtained in the same manner. However, the film thickness was 60 μm. The obtained seamless rotary member had a resistivity of 10 ¹² Ωcm in the thickness direction and could be used as a transfer belt of an electrophotographic photosensitive printer.

Example 3 In the polyamic acid solution of Example 1, 20% by weight of solids of carbon black (same as in Example 2) and 3% by weight of dioctyl sulfosuccinate surfactant (commercially available) (Name: Sanmorin, manufactured by Sanyo Chemical Co., Ltd.) and dispersed with a ball mill. Then the inner diameter 8
SUS304 of 0mmφ × 360mm length × 2.0mm thickness
Prepare a cylinder, and at one end, the height is 10m
m with a conical lid attached. A baking release agent layer was formed on the inner surface of the mold in the same manner as in Example 1. The dispersion obtained as described above was placed in a mold and then the mold was inverted to drain the dispersion. After 5 minutes, the solvent was dried by blowing hot air at 150 ° C. while rotating the mold horizontally at 900 rpm.

After drying, the top of the convex portion at the end was pinched, and the film was pulled and peeled. After separating the end portion from the peeled intermediate film, it was fitted into a nickel-made flexible cylindrical body having an outer diameter of 80 mm and a thickness of 0.1 mm, and this was further outer diameter of 78 m.
It was fitted into a SUS cylinder having a diameter of 3 mm and a diameter of 3 mm. Then 3
It was cured by heating at 50 ° C. for 1 hour. After that, Example 1
Peel off the seamless rotary body in the same manner as
A seamless body of 340 mm length and 50 μm thickness was obtained.
This seamless rotator had a resistivity of 10 ¹⁰ Ωcm and could be used as a substrate for an organic photoconductive (OPC) photoreceptor.

As a method of manufacturing the OPC photoreceptor, first, a seamless rotary member is fixed to an Al pipe having an outer diameter of 80 mmφ with a polyester adhesive tape so as not to be impregnated with a liquid, and a type 8 nylon resin (trade name: lactamide, Dainippon Japan) Dip coating with 2% methanol solution
A thick undercoat layer was formed. On the other hand, 1 part (parts by weight, hereinafter the same) of a polyvinyl butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 19 parts of cyclohexanone, and 8 parts of dibromoanthanthrone was added thereto and dispersed by a sand mill. Further, 20 parts of 2-butanone was added and dip-coated on the undercoat layer to form a 0.8 μm thick CGL.
Next, N, N'-diphenyl-N, N '-(m-tolyl)
36 parts of benzidine and 64 parts of polycarbonate Z resin are dissolved in 300 parts of mochlorobenzene, dip-coated on CGL, and dried at 110 ° C. for 40 minutes to form a CTL of 18 μm thickness.
Was formed. Thereafter, the seamless rotary member was removed from the Al pipe to obtain an OPC photosensitive member.

(Example 4) In Example 1, the surface of the nickel-made flexible cylinder when the intermediate film was cured by heating was roughened by sandblasting. The surface roughness was a mirror surface with Ra = 0.03 μm. A seamless rotary member was produced in exactly the same manner as in Example 1 except that the resin was heated and cured using this. The obtained seamless rotary body had a rough inner surface, and the peelability of the film was easier than in Example 1. Although this seamless rotary member could be used as a transport belt for an electrophotographic printer, the frictional force was somewhat improved because the inner surface was roughened.

Example 5 A solution of the polyamic acid in N-methylpyrrolidone in Example 1 was applied to a solution having a viscosity of 1600 mP.
The mixture was diluted with dioxane so as to be a second and heated at 120 ° C. for 5 minutes. Due to the short heating time, the dioxane did not evaporate immediately. About 90 viscosity by heating
Since the flow rate was reduced to 0 mPa · s and the fluidity was increased, the addition of a silicone leveling agent was unnecessary. The resin solution was placed in the same mold as in Example 1, and then the mold was inverted to drain the resin solution. After 2 minutes, level the mold to 800
While rotating at rpm, hot air at 150 ° C. was blown to dry the solvent. After drying for 40 minutes, the top of the convex portion at the end is pinched, the film is pulled, and the intermediate film is peeled off. Thereafter, as in Example 1, 120 mmφ, 340 m
A seamless rotating body having a length of 50 m and a length of 50 m was obtained. Example 1
In the case of the rotary member having no seam, the error of the film thickness was ± 2.0 μm, but in the case of this embodiment, the error was improved to ± 1.4 μm.

[0030]

As described above, in the present invention, the metal-made flexible cylindrical body is used as the mold when the cured seamless rotary body is peeled from the mold, so that it can be flexed moderately. It can be dented and deformed,
Thereby, the seamless rotary body can be easily separated from the mold.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rigid cylindrical body.

FIG. 2 is a perspective view of a flexible metal cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Intermediate film, 2 ... Rigid cylindrical body, 3 ... Inclined surface, 4 ...
Resin swell, 5 ... flexible metal cylinder, 6 ...
Seamless rotating body.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/16 G03G 15/16 15/20 103 15/20 103 // B29K 101: 10

Claims (4)

[Claims] 1. A method of applying a solution of a thermosetting film-forming resin to an inner surface of a rigid cylinder, heating the solvent to evaporate the solvent, and peeling the formed film from the inner surface of the cylinder.
A method for producing a seamless rotary body, characterized in that a seamless rotary body made of a thermosetting film is obtained by covering the flexible cylindrical body made of metal with thermosetting. 2. The method for producing a seamless rotary member according to claim 1, wherein a metal-made flexible cylinder covered with a film is fitted into a rigid cylindrical member during the heat curing. 3. The method for producing a seamless rotary body according to claim 1, wherein the flexible cylindrical body made of metal has a roughened surface. 4. A method for applying a solution of a thermosetting film-forming resin to an inner surface of a rigid cylindrical body, the solution comprising 50 to 2 times.
The method for producing a seamless rotary member according to claim 1, wherein the rotary member is heated to 00 ° C.