JP2001249579A - Base body for photoreceptor drum and photoreceptor drum using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base body for photoreceptor drum with which a high performance photoreceptor drum is obtained, through employing the advantages, such as good conducting, lightweight, and easiness of workability, by integrally forming a cylindrical base body, a flange, and a gear for driving by resin without the sacrifice of each performance, and to provide a photoreceptor drum using the base body. SOLUTION: In the substrate for photoreceptor drum which has the flange 2 made of the resin integrally formed with a pipe main body 1 at least at an opening part of one end of the cylindrical resin pipe main body 1 and in which the gear 6 for driving is integrally formed at the flange, the gear 6 for driving or the flange 2 formed with the gear 6 for driving is made of different resin material from the material of the pipe main body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical body of a photosensitive drum used in an electrophotographic apparatus or an electrostatic recording apparatus. More specifically, a flange having a driving gear at least at one end is integrally formed. To a photosensitive drum substrate and a photosensitive drum using the substrate.

[0002]

2. Description of the Related Art In an electrostatic recording process in a copying machine, a facsimile, a printer, or the like, first, the surface of a photosensitive drum is charged uniformly.
An electrostatic latent image is formed by projecting an image from the optical system on the surface of the photosensitive drum to eliminate the charging of the portion exposed to the light, and then supplying toner to the electrostatic latent image to supply the electrostatic latent image with toner. A toner image is formed by the objective adhesion,
Printing is performed by transferring the image onto a recording medium such as P, photographic paper, or the like.

As a photosensitive drum used in such an electrostatic recording process, a photosensitive drum having a structure shown in FIG. 2 has been generally used.

[0004] That is, generally used are those in which flanges 2a and 2b are fitted and fixed to both ends of a cylindrical substrate 1 having good conductivity, and a photosensitive layer 3 is formed on the outer peripheral surface of the cylindrical substrate 1. Normally, as shown in FIG. 2, the photosensitive drum has support shafts 4, 4 provided on a main body a of the electrophotographic apparatus, and shaft holes 5, provided on both flanges 2a, 2b.
5 and rotatably supported, and one flange 2
The gear 7 connected to a driving source such as a motor meshes with the driving gear 6 formed in the section b, and is driven to rotate.

In this case, as a material for forming the cylindrical substrate 1, an aluminum alloy has been conventionally used because it is relatively lightweight, has excellent machinability, and has good conductivity.

However, cylindrical substrates made of an aluminum alloy must be individually machined with high precision in order to satisfy strict dimensional accuracy requirements and predetermined surface roughness. , 2b to be fitted and fixed, and in some cases, processing to prevent oxidation of the surface is required. For this reason, there is a problem that the number of manufacturing steps is increased and the manufacturing cost is increased, and the aluminum alloy is not always satisfactory as a material for the cylindrical base constituting the photosensitive drum.

On the other hand, a resin pipe obtained by injection-molding a conductive resin composition obtained by mixing and dispersing a conductive agent such as carbon in a thermoplastic resin is used as a cylindrical substrate 1, and a photosensitive layer 3 is formed on the outer peripheral surface of the substrate 1 of the conductive resin pipe. Is applied to obtain a photosensitive drum. When a resin base is used as described above, at least one of the flanges 2a and 2b is formed integrally with the resin base 1 by a resin. The driving gear 6 may be integrally formed with the formed flange.

According to the photosensitive drum using the resin base, many processing steps required when the above-described aluminum alloy base is used can be omitted, and the weight of the photosensitive drum can be reduced. You can also plan. In addition, by forming the flange and the driving gear integrally with the base, conduction between the flange and the driving gear and the base can be performed extremely stably.

However, when the flange and the driving gear are formed integrally with the cylindrical base, the performance required for these two members is different, so that a high-performance photosensitive drum is not always obtained.

That is, as shown in FIG. 2, a photosensitive layer 3 is coated and formed on the outer peripheral surface of the cylindrical substrate 1, and an image is formed on the photosensitive layer 3, so that good coating is obtained. An excellent surface smoothness is required to obtain the workability, and a high dimensional system is required to have a small difference in outer diameter and to be excellent in straightness and roundness in order to improve image quality. On the other hand, the flange and the driving gear are required to have sufficient rigidity to stably support and drive the cylindrical base body and slide between the support shaft and other gears. Sufficient wear resistance is also required.

As described above, since the cylindrical base and the flange and the driving gear have different required performances, when they are integrally formed, either performance is often sacrificed, and the performance is not necessarily high. At present, it is impossible to obtain a suitable photosensitive drum.

The present invention has been made in view of the above circumstances, and a cylindrical base, a flange, and a driving gear are integrally formed of resin without sacrificing any performance.
It is an object of the present invention to reliably obtain a high-performance photosensitive drum by making full use of advantages such as good conduction, light weight, and easiness of processing.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a cylindrical resin pipe body having at least one end provided with a resin flange integrally formed with the pipe body. Wherein the driving gear or the flange on which the driving gear is formed is made of a resin material different from the pipe body. Wherein the photosensitive drum substrate of the present invention is used as a cylindrical substrate, wherein the photosensitive drum is formed by coating a photosensitive layer on the outer peripheral surface of a cylindrical substrate. Provide drums.

That is, as described above, the photosensitive drum substrate of the present invention is provided on at least one end of the cylindrical resin pipe main body.
It has a resin flange integrally formed with the pipe main body, and a driving gear is integrally formed with the flange. In this case, the pipe main body and the driving gear are formed by two-color molding or insert molding. The gear or the flange on which the driving gear is formed is integrally formed of a different resin material.

Accordingly, the pipe body is formed of a resin material having excellent dimensional accuracy, dimensional stability, and surface smoothness, and the driving gear or the flange on which the driving gear is formed is rigid and abrasion resistant. By forming with excellent resin material, without deteriorating the performance of any member,
By integrally molding these with resin, it is possible to obtain a good conductivity between both members and to reduce the weight, and it is possible to easily and inexpensively produce a photosensitive drum base by good workability,
Further, by using this substrate, a high-performance photosensitive drum can be obtained reliably and at low cost.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail. As described above, the resin pipe of the present invention has a resin flange integrally formed with the pipe main body at at least one end of the cylindrical resin pipe main body, and a driving gear is integrally formed with the flange. In the present invention, the pipe body and the driving gear or the flange on which the driving gear is formed are integrally formed of different resin materials.

In this case, the drive gear rotates while meshing with a gear connected to a drive source such as a motor.
Since particularly excellent wear resistance is required, in the present invention, at least this drive gear may be formed of a resin material having excellent wear resistance different from the resin material forming the pipe body, The flange may be made of the same material as the pipe body, but this flange also has good rigidity for stably supporting the pipe body and good abrasion resistance for sliding between the support shaft. Since wear resistance is required, it is preferable that the drive gear is formed of a different material having the same rigidity and abrasion resistance as the driving gear.

Examples of the connection between the pipe main body and the driving gear or the flange on which the driving gear is formed are those shown in FIGS. 1A to 1F. That is, (A) is obtained by joining and integrating one end surface of the pipe main body 1 and the inner surface of the flange 2 having the driving gear 6 on the outer peripheral surface. (C) in which the flange 2 having the driving gear 6 on the inner peripheral surface is integrated with the inner peripheral surface of one end of the pipe body 1. (D) is obtained by externally integrating a flange 2 having a driving gear 6 on an inner peripheral surface thereof on one end outer peripheral surface of a pipe main body 1, and these (A) to (D) show the flange 2.
And the drive gear 6 are formed of the same different material different from the pipe body 1. (E) shows the pipe body 1
A drive gear 6 made of a different material is joined and integrated to an outer peripheral surface of a flange 2 integrally formed of the same material as that of FIG. A drive gear 6 made of a different material is joined and integrated with the inner peripheral surface of the flange 2.

The method of joining and integrating the pipe 1 and the flange 2 or the flange 2 and the driving gear 6 formed of the above-mentioned different materials is not particularly limited, but may be performed by two-color molding or insert molding. Can be. in this case,
In the insert molding, a preformed flange 2 may be set in a mold, and the pipe body 1 may be integrally formed with the flange 2. The flange 2 may be formed integrally with the pipe main body 1 by setting it in a mold. However, when only the driving gear 6 shown in FIGS. 1E and 1F is formed of a different material, A method is adopted in which a pipe body 1 having a flange 2 formed in advance is set in a mold, and a driving gear 6 is integrally formed with the flange 2 provided on the pipe body 1.

The pipe body 1 and the flange 2 which have been formed in advance can be formed by a usual injection molding method. The molding conditions in this case and the molding conditions for the two-color molding or insert molding can be ordinary conditions according to the resin material used.

As the resin material forming the pipe main body, a thermoplastic resin or a resin composition based on a thermoplastic resin is used. In this case, as the thermoplastic resin,
Any material can be used as long as it can be formed into a pipe by an injection molding method, and a known resin material conventionally used for a substrate for a photosensitive drum can be used.
Particularly, polyamide resins such as various nylons are preferably used because they have good surface smoothness for forming a photosensitive layer, and are excellent in chemical resistance and mechanical strength. Among them,
At least one selected from a polyamide resin obtained from meta-xylylenediamine and adipic acid, a polyamide resin obtained from ε-caprolactam, and an alloy resin obtained by blending a polyamide resin with a resin having a water absorption of 0.3% or less. It can be preferably used.

The polyamide resin produced by the polycondensation reaction between metaxylylenediamine and adipic acid is generally called nylon MXD6, and the polyamide resin obtained by ring-opening polymerization of ε-caprolactam is used. The resin is generally called nylon 6.

An alloy resin blended with the polyamide resin of the present invention and a resin having a water absorption of 0.3% or less,
It can be suitably used for the following reasons.

That is, although it has been proposed to form a cylindrical substrate with a conductive resin based on a polyamide resin, these polyamide resins (PA) are made of PA6.
6 and PA6, etc., have a high water absorption and a water absorption rate (AST
M-D570), PA66 is about 0.6 to
3% and PA6 are about 0.7 to 1.8%, which are relatively higher than other resins. For this reason, a problem may occur in terms of maintaining the dimensional accuracy of the product, and the temperature may be 30 ° C. or more and 90% RH or less.
Under high-temperature and high-humidity conditions such as those described above, dimensional expansion may occur due to water absorption even when exposed for about 2 to 3 hours. For this reason, the function of the photoconductor may be affected, and as a result, the image quality may be significantly affected.

The polyamide resin of the present invention has a water absorption of 0.3
% Resin is blended with a resin having a high water absorption such as polyamide resin and a resin having a water absorption of 0.3% or less to form an alloy. Therefore, it is possible to reduce the water absorption rate and to impart a property with little dimensional change even in a high temperature and high humidity environment.

As the polyamide resin to be blended, a known resin can be used. Specifically, nylon MX
D6, nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, nylon 6
12, polyamide 1212, and other polyamide resins such as copolymers thereof, and are not particularly limited.

Resins having a water absorption of 0.3% or less blended with the polyamide (hereinafter referred to as blending resins) include PP (polypropylene), PPE
(Polyphenylene ether), PPS (polyphenylene sulfide) and the like.
S and PPE are more preferably PPE.

The polyamide resin of the present invention has a water absorption of 0.3
% In order to obtain an alloy resin blended with the resin of not more than 1% by mass, usually 1 to 70% by mass, preferably 5 to 50% by mass, Preferably, it can be obtained by blending so as to be 10 to 40% by mass.

In the above blending, both resin components are used in order to further improve the compatibility between the polyamide resin and the blended resin to enhance dispersibility, and to improve mechanical properties such as strength, water absorption and chemical resistance. A compatibilizing agent having a high affinity for is suitably used. Examples of the compatibilizer include maleic acid-modified polypropylene (maleic acid-modified PP), PA-PPS-based, and P-PP-based.
For the A-PPE system, epoxy-modified polystyrene (epoxy-modified PS) -polymethyl methacrylate (P
MMA) copolymer and the like.

The polyamide resin of the present invention has a water absorption of 0.3
%, As described above, has excellent dimensional stability as compared with a molded product using another polyamide resin alone as a resin component. A reference example comparing this point is shown in the following table. Table 1 below
The water absorption and dimensional change shown in the above are the differences between before and after standing for 24 hours in a high-temperature and high-humidity tank under a 50 ° C-95% RH environment, and by blending a polyamide resin with a resin having a low water absorption, It is recognized that the water absorption and the dimensional change of the molded article under a high temperature and high humidity environment are dramatically improved.

[0031]

[Table 1]

In the present invention, a plurality of resins may be mixed to form a molding material, and an alloy resin obtained by blending the above nylon MXD6, nylon 6, and polyamide resins with a resin having a water absorption of 0.3% or less, and another resin may be used. May be used as a mixture. In this case, the other resin is not particularly limited, but other polyamides such as nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, nylon 612, nylon 1212, and copolymers thereof. It is preferable to use a resin. When these other resins are mixed, the mixing ratio is not particularly limited, but is at least 30 to 100% by mass, particularly 40 to 100% by mass in the resin component constituting the composition.
Is preferably an alloy resin obtained by blending the nylon MXD6, nylon 6, or polyamide resin with a resin having a water absorption of 0.3% or less, or a mixture thereof.

Usually, a conductive agent is added to the thermoplastic resin.
Is added to impart appropriate conductivity. In this case,
As an electric agent, it can be uniformly dispersed in the above resin.
Anything is possible, for example, carb
Black, graphite, aluminum, copper, nickel
Metal powder such as metal, conductive glass powder, etc.
It is preferable to use carbon black. Conductive agent
The amount of addition is not particularly limited.
5 to 30% by mass of the composition,
It is preferably 5 to 20% by mass.
The sheet resistance is 10 ⁶Ω / □ (ohm / square) or less, special
To 10^FiveΩ / □ or less, preferably 10^FourΩ / □ or less
It is recommended that

Further, an inorganic filler such as various fibers can be blended with the resin material for the purpose of reinforcing and increasing the amount. As the inorganic filler, conductive fibers such as carbon fibers, conductive whiskers, and conductive glass fibers, and whiskers and non-conductive fibers such as glass fibers can be used. In this case, the conductive fiber can also function as a conductive agent, and the use of the conductive fiber can reduce the amount of the conductive agent used.

The compounding amount of these fillers is appropriately selected according to the strength required for the pipe body, the type of filler used, the length and diameter of the fiber, and the like, and is not particularly limited. 1 to 30% by mass of the product, more preferably 5%
It is preferably set to と す る 25 mass%, more preferably 10 to 25 mass%. In this case, by adding such a filler, the strength and rigidity of the molded article can be effectively improved without lowering the surface smoothness.

The resin material forming the pipe body may include, if necessary, polytetrafluoroethylene (PTFE), silicone, molybdenum disulfide (MoS ₂ ), various metals, in addition to the above-mentioned conductive agent and filler. A known additive such as soap can be added in an appropriate amount. The conductive agent and the filler may be subjected to a surface treatment using a commonly used silane coupling agent or titanate coupling agent.

The outer peripheral surface of the pipe body is not particularly limited, but the surface roughness is determined by the center line average roughness R.
0.8 μm or less, especially 0.2 μm or less at a, maximum height R
It is preferable that the maximum value is 1.6 μm or less, particularly 0.8 μm or less, and the 10-point average roughness Rz is 1.6 μm or less, particularly 0.8 μm or less. Irregularities on the surface appear on the photosensitive layer, which may cause image defects. As a molding material, a polyamide resin obtained from the above meta-xylylenediamine and adipic acid, a polyamide resin obtained from ε-caprolactam, and an alloy resin obtained by blending a polyamide resin and a resin having a water absorption of 0.3% or less are used. By using at least one kind, even when an inorganic filler for reinforcement is added, such surface roughness can be easily achieved.

Next, the resin material for forming the flange 2 and / or the driving gear 6 can provide the rigidity and abrasion resistance required for the flange 2 and the driving gear 6, and can be injection molded. Any material may be used, for example, polyacetal, polyamide (PA6, P
A66, PA11, PA12, PA46, aromatic PA, etc.), polyurethane, polyester, polyethylene, polypropylene, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyamide imide, polyimide and the like. Can be used. In this case, the polyamide, polyurethane, polyester and the like may be an elastomer in some cases.

The resin material for forming the flange 2 and / or the driving gear 6 is also generally mixed with a conductive agent for imparting conductivity. The same thing as the thing illustrated is illustrated, and the compounding amount is also the same. In addition, reinforcing fillers and other additives can be added as needed in the same manner as in the case of the pipe body, and further, known lubricants, flame retardants, antistatic agents, etc. are added in appropriate amounts as necessary. can do.

In the photosensitive drum substrate of the present invention, the flange 2 and / or the driving gear 6 on at least one end of the pipe main body 1 are integrally formed by a two-color molding method or an insert molding method using the above-mentioned different materials. The flange on the other end side may be assembled with a separately formed flange as in the related art.

The photosensitive drum substrate of the present invention is formed as a photosensitive drum by coating and forming a photosensitive layer on the outer peripheral surface of the pipe main body 1. This photosensitive layer is formed by coating with a known material and method. And the layer configuration may be a known configuration. Further, other configurations can be the same as those of a normal photosensitive drum.

[0042]

As described above, according to the photosensitive drum substrate of the present invention, the cylindrical substrate, the flange and the driving gear are integrally formed of resin without sacrificing any performance. It is possible to reliably obtain a high-performance photosensitive drum by making full use of advantages such as good conduction, light weight, and ease of processing.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view showing an embodiment of a photosensitive drum base of the present invention.

FIG. 2 is a cross-sectional view illustrating a general configuration of a photosensitive drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical base body (pipe main body) 2, 2a, 2b Flange 3 Photosensitive layer 4 Support shaft 5 Shaft hole 6 Driving gear

Claims (5)

[Claims] At least one end of a cylindrical resin pipe main body has a resin flange formed integrally with the pipe main body, and a driving gear is formed integrally with the flange for a photosensitive drum base. 2. The photosensitive drum substrate according to claim 1, wherein the driving gear or the flange on which the driving gear is formed is made of a resin material different from the pipe body. 2. The photosensitive drum substrate according to claim 1, wherein the pipe body and the driving gear or the flange on which the driving gear is formed are integrated by two-color molding or insert molding. 3. The pipe body is made of a polyamide resin obtained from meta-xylylenediamine and adipic acid, ε-
The photosensitive material according to claim 1, wherein the photosensitive material is formed of a polyamide resin obtained from caprolactam and a resin material containing at least one selected from an alloy resin blended with a polyamide resin and a resin having a water absorption of 0.3% or less. Substrate for drum. 4. The driving gear or the flange on which the driving gear is formed is made of polyacetal, polyamide, polyurethane, polyester, polyethylene, polypropylene, polycarbonate, polybutylene terephthalate,
The photosensitive drum substrate according to any one of claims 1 to 3, wherein the substrate is formed of a resin material containing one or more resins selected from polyphenylene sulfide, polyamide imide, and polyimide. 5. A photosensitive drum in which a photosensitive layer is formed by coating a peripheral surface of a cylindrical substrate, wherein the substrate according to claim 1 is used as the cylindrical substrate. Characteristic photosensitive drum.