JP2000181100A - Bobbin for producing electrophotographic photoreceptor and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defects of a coating film on the surface caused by worn particles produced by friction between a work and a bobbin, so as to obtain satisfactory photoreceptor by using a polymer alloy consisting of polyphenylene sulfide(PPS) and fluororesin as the base material. SOLUTION: This bobbin for producing a photoreceptor 1 is obtained, by using the polymer alloy consisting of PPS and fluororesin as the base material. It is desirable that the bobbin 1 has blade type structure have three or more blade parts 2 fit to the internal surface of the work (has four blade parts), and the blade part 2 be inclined so that the angle θ of its end inserted in the work to an inserting direction is 5 deg. to 45 deg.. BY making the bobbin 1 have such a blade type structure, the contact area of the bobbin fit to the internal surface of the work is made small. By adjusting the insertion angle θ of the end of the blade part 2 inserted in the work, collision and wear caused by attaching/ detaching the work are reduced and the worn particles are prevented from being produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin for producing an electrophotographic photosensitive member (hereinafter, also simply referred to as "photosensitive member") used for carrying a work in a process of coating a photosensitive layer, and a method for producing the same. Here, the work refers to a photoconductor in a manufacturing process, and is composed of only a conductive substrate before a coating process of a photosensitive layer, and is generally a raw aluminum tube.

[0002]

2. Description of the Related Art In general, the coating process of an organic photoreceptor using an organic material for a photosensitive layer is performed by washing an aluminum pipe as a substrate, and then forming an undercoat layer, a charge generation layer and a charge transport layer on the outer surface thereof. It consists of a series of steps of successively applying and drying to form. Throughout this process, a bobbin is inserted into the work and transported, and the work is detached from the bobbin for each process, and washing, coating, and drying are performed.

[0003] Such bobbins are generally formed by injection molding, and as a resin material to be used, have good moldability and are resistant to the coating process of an organic photoreceptor (heat resistance of 150 ° C or higher, solvent resistance, abrasion resistance). ) And is also economical, so polyphenylene sulfide (hereinafter referred to as “PP
S ").

[0004]

However, the conventional bobbin made of PPS has a problem that a surface defect of a coating film is caused by abrasion powder in the process of repeated use. Since an aluminum element tube is generally used for the photoreceptor substrate, when the resin bobbin and the element tube come into contact with each other, the bobbin wears to generate abrasion powder, and the abrasion powder adheres to the workpiece. When coating is carried out in the above manner, surface defects occur in the coating film.

[0005] Usually, a fiber such as glass fiber is added to a bobbin made of PPS to obtain the strength of the bobbin, and a filler such as calcium carbonate is added for economy. As a result, the cross section of the formed bobbin is
As shown in FIG. 3, it is composed of a PPS skin layer 4 and a bulk layer 5 in which PPS, fibers and additives are mixed. The portion of the skin layer 4 has good wear resistance with the work because the characteristics of PPS are utilized, but since it is a thin layer, it is worn in the process of repeated use, and once the bulk layer 5 is used.
Appears, wear progresses remarkably, and the surface defects of the work coating film frequently occur.

Further, since the bobbin is made of resin, there is a problem that environmental dust easily adheres to the surface of the bobbin electrostatically. If this dust adheres to the workpiece and is applied, it will cause a surface defect of the coating, or if it enters the coating tank and contaminates the coating liquid, it will also cause photoreceptor characteristics due to surface defects and deterioration of the coating liquid. It may cause abnormalities.

As another problem, there is a structure of a molding die for bobbins. Conventionally, as shown in FIG. 5, a mold cavity 10 divided for economy is used. In this case, as shown in FIG.
A separate line (divided portion) 13 of the mold cavity is provided at the ridge line of the blade portion 12 of the above. As a result, burrs are formed along the separate line at the ridge line of the blade portion 12 of the formed bobbin 11. . The burrs easily generate abrasion powder upon contact with the work, causing a coating film defect on the work.

Accordingly, an object of the present invention is to provide a bobbin for manufacturing a photoreceptor capable of preventing the occurrence of coating film defects on the surface due to abrasion powder generated by friction between a work and a bobbin and obtaining a good photoreceptor. It is in.

Another object of the present invention is to provide a bobbin for manufacturing a photoreceptor in which dust does not adhere to the bobbin surface due to static electricity in addition to the above.

Another object of the present invention is to provide a method of manufacturing a bobbin for manufacturing an electrophotographic photoreceptor, in which burrs do not occur at the ridges of the blades in a molded product of a bobbin.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer alloy of PPS and a fluororesin is used as a base material of a bobbin used for transferring a work. The present inventors have found that it is possible to prevent the occurrence of coating film defects on the surface due to abrasion powder generated by friction between the photoreceptor and the bobbin, and have completed the present invention.

That is, the bobbin for producing a photoreceptor of the present invention is a bobbin for producing a photoreceptor used for transporting a work in a process of coating a photosensitive layer, wherein the bobbin is made of a polymer alloy of PPS and a fluororesin. It is a feature.

In the bobbin for producing a photoreceptor of the present invention,
A skin layer is formed during the injection molding, and the skin layer preferably has a thickness of 0.5 μm or more. In addition, at least one of a filler, a reinforcing material, and a conductive material can be added to the base material. Preferably, carbon black or carbon fiber is added as the conductive material. Further, the photoreceptor manufacturing bobbin of the present invention has a blade-type structure having three or more blade portions fitted to the inner surface of the work, and the insertion end of the blade portion into the work is 5 mm in the insertion direction.
Preferably, it is inclined at ~ 45 °. Furthermore,
Preferably, the kinetic friction coefficient of the bobbin surface is 0.3 or less, and the kinetic friction coefficient of the inner bulk layer is 0.35 or less.

The present invention also relates to a method of manufacturing the photoconductor-producing bobbin. In this manufacturing method, the molding of the photoconductor-producing bobbin is performed by using a separate line provided at a position avoiding the blade portion of the bobbin. It is characterized in that it is performed using a mold cavity.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. The photoreceptor manufacturing bobbin used for transporting the work is used by inserting it into the work, and the work is detached from the bobbin for each process, and is washed, coated, and dried. According to the present invention, the base material of the bobbin is made of a polymer alloy of PPS and a fluororesin, thereby making it possible to prevent the occurrence of coating film defects on the surface due to abrasion powder generated by friction between the work and the bobbin. became.
In addition, in the bobbin of the present invention, not only the smoothness of the surface but also the smoothness of the inner bulk layer could be improved by using the polymer alloy of PPS and the fluororesin as the base material. Therefore, even if the skin layer on the surface is shaved, the smoothness of the bulk layer itself is superior to that of the conventional bulk layer. Has been confirmed to have been suppressed.

A filler such as calcium carbonate can be added to the polymer alloy according to the present invention for economy, and a reinforcing material such as glass fiber can be added for improving mechanical strength. Further, in order to prevent dust from adhering to the surface of the bobbin due to static electricity, it is preferable to lower the resistance value of the bobbin by adding a conductive material, and more preferably to add carbon black or carbon fiber. The conductive material is preferably added in an amount of 30% by weight or less based on the base material from the viewpoint of moldability.
Cm or 0.01 Ω · cm. Such a polymer alloy is, for example, trade name RFC21
It is available on the market as 30U (manufactured by Asahi Glass Co., Ltd.).

The bobbin of the present invention can be manufactured by injection molding, whereby a skin layer as shown in FIG. 3 is formed. The injection molding conditions, such as temperature and pressure, are appropriately adjusted so that the thickness of the skin layer 4 is preferably 0.5 μm or more. In the present invention, the skin layer 4
Is composed of a polymer alloy of PPS and a fluororesin, and the bulk layer 5 below the skin layer is composed of the polymer alloy and an additive such as a filler or carbon fiber. Therefore, the skin layer 4 can be made thicker by reducing the amount of the additive. The skin layer 4 has a better slip than the bulk layer 5, and therefore has a smaller wear amount than the bulk layer 5. Therefore, by increasing the thickness of the skin layer 4, the bulk layer 5 can be protected.

As shown in FIGS. 1 and 2, the bobbin 1 of the present invention has three or more blade portions 2 fitted to the inner surface of a work 3.
(In the example shown in FIG. 1, four blade portions are provided), and the angle θ of the blade portion 2 with respect to the insertion direction of the insertion end of the blade 3 into the work 3 is inclined at 5 to 45 °. Is preferred. The blade-type structure reduces the contact area of the bobbin that fits with the inner surface of the work, and adjusts the insertion angle θ of the insertion end of the blade portion 2 into the work 3 to cause collision or wear due to attachment and detachment of the work 3. Can be reduced, and generation of abrasion powder can be suppressed. Further, it is preferable that the number of the blade portions 2 is three or more in consideration of strength and the thickness of the blade portion 2.

Further, in the bobbin for producing a photoreceptor of the present invention, it is preferable that the kinetic friction coefficient of the bobbin surface is 0.3 or less and the kinetic friction coefficient of the inner bulk layer is 0.35 or less. Thereby, in order to suppress the friction between the bobbin and the work and enhance the slidability, it is possible to suppress the bobbin from being scraped and to suppress dust generation.

In the method of manufacturing a bobbin according to the present invention, as shown in FIG. 4, the bobbin 1 is formed by splitting a mold cavity 7 having a separate line 6 at a position avoiding the blade portion 2 of the bobbin 1. This is performed using As a result, no burrs are formed on the blade portion 2 of the formed bobbin, and one of the causes of the coating film defect on the work is eliminated.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. First, an abrasion test was performed on test pieces made of the following test materials 1 and 2 in accordance with JIS H8503-1983. Test material Test material 1: PPS resin obtained by adding 30% by weight of carbon fiber and 30% by weight of fluorine to PPS (trade name: FORTRON 7140A4, manufactured by Polyplastics Co., Ltd.) Test material 2: 50% by weight of PPS, modified fluorine Polymer alloy composed of 20% by weight of resin and 30% by weight of carbon fiber (trade name: RFC2130U, Asahi Glass Co., Ltd.)
Made)

Wear test conditions Load 700 gf Wear wheel Aluminum 5052 18S finished surface Number of times of sliding 2000 times (Wear wheel 5 laps) The results of the wear test are shown in Table 1 below.

[0023]

[Table 1] * 1) The wear depth is extremely small, and the wear surface is not evenly worn, which is only a reference value. * 2) The appearance of the worn surface is based on observation of a laser microscope photograph of the worn surface. The laser microscope measures the length using a confocal optical system, and has a narrow depth of field, on the order of 0.1 μm. * 3) Dynamic friction coefficient on the surface (skin layer) * 4) Dynamic friction coefficient on the bulk layer under the surface of 0.5 to 1.0 mm

Comprehensively judging from Table 1, it is understood that the test material 2 according to the present invention has a small amount of abrasion, has good compatibility with aluminum, and satisfies other various conditions.

Next, a bobbin was prototyped by injection molding using the test material 2 as follows. Example 1 A polymer alloy (trade name: RFC2130U, manufactured by Asahi Glass Co., Ltd.) composed of 50% by weight of PPS, 20% by weight of modified fluororesin and 30% by weight of carbon fiber was prepared by using a split mold cavity shown in FIG. Mold temperature 14
Injection molding was performed at 0 ° C. to produce a bobbin having the shape shown in FIG. The thickness of the skin layer of this bobbin was 1.0 μm.

Example 2 A bobbin was manufactured in the same manner as in Example 1 except that the temperature of the mold was set to 150 ° C. The thickness of the skin layer of this bobbin was 1.3 μm.

Comparative Example 1 In place of the polymer alloy in Example 1, PPS3 was used.
PPS resin obtained by adding 45% by weight of glass fiber and 20% by weight of glass beads to 5% by weight (trade name: FORTRON 6465A6, manufactured by Polyplastics Co., Ltd.)
A bobbin was produced in the same manner as in Example 1 except that was used. The thickness of the skin layer of this bobbin was 0.5 μm.

Comparative Example 2 Except for using a PPS resin (trade name: FORTRON 1140A64, manufactured by Polyplastics Co.) obtained by adding 40% by weight of glass fiber to PPS instead of the polymer alloy in Example 1, A bobbin was manufactured in the same manner as in Example 1. The thickness of the skin layer of this bobbin is 0.
It was 8 μm.

Comparative Example 3 A PPS resin obtained by adding 30% by weight of carbon fiber and 10% by weight of fluorine to PPS instead of the polymer alloy in Example 1 (trade name: FORTRON 714)
0A4, manufactured by Polyplastics Co., Ltd.), and a bobbin was produced in the same manner as in Example 1. The thickness of the skin layer of this bobbin was 0.9 μm.

Regarding the bobbin surfaces prepared in Examples 1 and 2 and Comparative Examples 1 to 3, the surface morphology observation before treatment, the morphology observation of the section with a blade (evaluation of skin layer), and the surface morphology observation after polishing with a grinder were described above. Was performed using a laser microscope, and the abrasion was evaluated.

As a result, the surface irregularities of Comparative Examples 1 to 3 were more remarkable than those of Examples 1 and 2 as observed before the treatment. After polishing the surface with a grinder (particle size 120), the unevenness of the polished surface was observed again. As a result, the polymer alloys of Examples 1 and 2 showed less unevenness than those of the comparative example. Therefore, it was confirmed that the bobbin of the example generated less dust from the abrasion surface than the bobbin of the comparative example. It should be noted that no difference was found between Examples 1 and 2 due to the temperature of the mold.

[0032]

According to the bobbin of the present invention used for transporting a work in a coating process, the occurrence of a coating defect on the surface of the photoreceptor due to abrasion powder generated by friction between the work and the bobbin is prevented. A photoreceptor can be obtained. Further, by adding a conductive material to the base material of the bobbin, it is possible to prevent dust from adhering due to static electricity. Further, in the bobbin manufacturing method of the present invention, no burrs are generated on the ridges of the blades, and no abrasion powder due to the burrs is generated upon contact with the work.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred example of a bobbin of the present invention.

FIG. 2 is a sectional view showing a bobbin inserted into a work.

FIG. 3 is an enlarged sectional view of a surface portion of the bobbin.

FIG. 4 is a structural diagram of a mold cavity according to the present invention.

FIG. 5 is a structural view of a conventional mold cavity.

[Explanation of symbols]

 Reference Signs List 1 bobbin 2 blade part 3 work 4 skin layer 5 bulk layer 6 separate line 70 split mold cavity 10 mold cavity 11 bobbin 12 blade part 13 separate line

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shozo Shinozaki 1-1-1 Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term (reference) 2H068 BB31 BB50 CA02 EA12 4F202 AA16 AA34 AB13 AB18 AE08 AH33 CA11 CB01 CB30 CK41

Claims (7)

[Claims] 1. A bobbin for producing an electrophotographic photosensitive member used for transporting a work in a process of coating a photosensitive layer, wherein the bobbin is made of a polymer alloy of polyphenylene sulfide and a fluororesin as a base material. Bobbins for manufacturing. 2. The bobbin for producing an electrophotographic photosensitive member according to claim 1, wherein a skin layer is formed during the injection molding, and the skin layer has a thickness of 0.5 μm or more. 3. The bobbin for producing an electrophotographic photosensitive member according to claim 1, wherein at least one of a filler, a reinforcing material, and a conductive material is added to said base material. 4. The bobbin according to claim 3, wherein the conductive material is carbon black or carbon fiber. 5. A blade-type structure having three or more blade portions fitted to the inner surface of the work, and the insertion end of the blade portion into the work is inclined at 5 to 45 ° with respect to the insertion direction. The bobbin for producing an electrophotographic photosensitive member according to claim 1. 6. The surface has a coefficient of kinetic friction of 0.3 or less,
The bobbin for producing an electrophotographic photosensitive member according to any one of claims 1 to 5, wherein a dynamic friction coefficient of the inner bulk layer is 0.35 or less. 7. The method of manufacturing a bobbin for manufacturing an electrophotographic photosensitive member according to claim 1, wherein the bobbin for manufacturing an electrophotographic photosensitive member is formed by separating a separate line from a blade portion of the bobbin. A method of manufacturing a bobbin for producing an electrophotographic photosensitive member, wherein the method is performed using a split mold cavity provided at a position where the bobbin is avoided.