JP2002031909A - Substrate for photosensitive drum and photosensitive drum using that substrate for photosensitive drum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the picture quality by properly controlling the surface glossiness because the surface glossiness of the substrate influences the picture quality of the image to be obtained when a photosensitive drum is obtained by forming a photosensitive layer on a resin substrate. SOLUTION: The substrate for a photosensitive drum consists of a synthetic resin pipe substrate showing 12 to 30 specular glossiness at 60 deg. according to JIS Z8741. The resin composition contains polyamide resin obtained from methaxylilene diamine and adipic acid and/or polyamide resin obtained from ε-caprolactam with 3 to 30 mass% blending proportion to the resin component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical substrate of a photosensitive drum used for an electrophotographic apparatus or an electrostatic recording apparatus, 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. 1 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. Usually, as shown in FIG. 1, 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 drive gear 6 may be formed integrally with the integrally 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, a photosensitive drum using this resin base may not always provide a satisfactory image quality, and it is desired to improve this point.

The present invention has been made in view of the above circumstances, and provides a photosensitive drum substrate capable of improving the image quality of a photosensitive drum using a resin substrate, and a photosensitive drum using the photosensitive drum substrate. The purpose is to provide.

[0011]

Means for Solving the Problems and Embodiments of the Invention The present inventors have made intensive studies to achieve the above object, and as a result, have obtained a photosensitive drum by forming a photosensitive layer on a resin base. In this case, it has been found that the surface gloss of the substrate affects the image quality of the obtained image, and that the image quality can be improved by optimizing the surface gloss. That is, when a conductive resin is used as the substrate of the photosensitive drum, it is necessary that the surface has a certain uniformity. In this case, if the glossiness of the substrate surface is too small, the surface property (smoothness, conductive ), It is difficult to maintain good electrical properties as a photosensitive drum, and if the gloss is too high, the gloss is too good, so that minute scratches and the like become more noticeable at the time of exposure. This has an adverse effect on the electrical characteristics, and this glossiness has a suitable range for improving the electrical characteristics of the photosensitive drum. By optimizing the glossiness, the image quality can be improved. Was found.

Therefore, the present inventor further studied to find an optimal surface glossiness as a photosensitive drum substrate, and found that the resin substrate surface had a glossiness of 12 to 30 as a 60-degree mirror glossiness according to JIS Z8741. , Preferably 15 to 2
By adjusting the value to 5, it has been found that a photosensitive drum having good electric characteristics can be surely obtained and the image quality can be improved, and the present invention has been completed.

Accordingly, the present invention provides a pipe-shaped substrate made of a synthetic resin, the surface of which has a 60-degree specular gloss of 12 to 30 according to JIS Z8741. The present invention provides a photosensitive drum in which a photosensitive layer is formed by coating a photosensitive layer on the outer peripheral surface of a cylindrical substrate, wherein the photosensitive drum substrate of the present invention is used as the cylindrical substrate.

Hereinafter, the present invention will be described in more detail.
As described above, the photosensitive drum substrate of the present invention is made of JIS
It is made of a synthetic resin pipe having a mirror gloss of 12 degrees at 60 degrees according to Z8741.

As the resin material forming the pipe,
Although not particularly limited, a thermoplastic resin or a resin composition based on a thermoplastic resin is preferably used.
In this case, as the thermoplastic resin, a known resin material conventionally used for a substrate for a photosensitive drum can be used. However, since it is particularly excellent in chemical resistance and mechanical strength, polyamide such as various nylons is used. Resins are preferably used. Specific examples of the polyamide resin include nylon M
Other polyamides such as XD6, nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, nylon 612, nylon 1212, and copolymers thereof can be given.

In this case, the above-mentioned polyamide resin may be used singly or as a mixture of a plurality of resins, and is not particularly limited, but is not limited to nylon MXD6 and / or nylon-6. It is preferable to use a mixture with a polyamide resin.

Here, the nylon MXD6 is a polyamide resin obtained from meta-xylylenediamine and adipic acid, and the nylon 6 is a polyamide resin obtained by subjecting ε-caprolactam to a ring-opening polymerization reaction. This nylon MXD6 and / or nylon 6
As the other resin to be combined with any of the polyamide resins described above, any of the polyamide resins described above can be used.
6, nylon 12, and nylon 46 are preferably used. The amount of the above-mentioned nylon MXD6 and / or the amount of the nylon 6 is not particularly limited.
It is preferably 0% by mass, particularly preferably 5 to 15% by mass.

In the resin forming the resin pipe, a conductive agent is usually added to impart conductivity and adjust the resistance value. The conductive agent may be any as long as it can be uniformly dispersed in the resin, and examples thereof include carbon black, graphite, metal powders such as aluminum, copper, and nickel, and conductive glass powder. However, it is particularly preferable to use carbon black. The amount of the conductive agent to be added is not particularly limited, but is 5 to 30% of the composition.
It is preferable that the surface resistance of the cylindrical substrate be 10 ⁶ Ω / □ (ohm / square) or less, particularly 10 ⁵ Ω / □ or less.

In addition, an inorganic filler such as various fibers can be blended in the resin forming the resin pipe 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 non-conductive fibers such as whiskers and glass fibers can be used. In this case, the conductive fiber is
It can also act as a conductive agent, and the use of the conductive agent can be reduced by using conductive fibers.

The compounding amount of these fillers is appropriately selected depending on the kind of the filler used, the length and diameter of the fiber, etc., and is not particularly limited, but is usually 5 to 40% by mass of the composition. It is more preferably about 10 to 30% by mass, and still more preferably about 15 to 20% by mass.

The resin forming the resin pipe includes:
If necessary, a known amount of known additives such as polytetrafluoroethylene (PTFE), silicone, molybdenum disulfide (MoS ₂ ), and various metal soaps can be added in addition to the conductive agent and the filler. 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 method of molding the resin pipe is not particularly limited, and may be a known method such as an injection molding method or an extrusion molding method. Usually, the injection molding method is preferably employed. In this case, molding conditions such as molding temperature and injection pressure are as follows:
It may be appropriately adjusted depending on the material used, but the temperature condition during molding affects the surface glossiness of the obtained resin pipe, so that it may be necessary to optimize it. This will be described later.

In the substrate for a photosensitive drum of the present invention, the surface glossiness of the resin pipe is adjusted to 12 to 30, preferably 15 to 25, a 60-degree specular gloss according to JIS Z8741. In this case, the glossiness can be adjusted by adjusting the composition of the resin forming the pipe. Specifically, the nylon MDX6 and / or
Alternatively, the glossiness can be achieved by using nylon 6 in the above-described compounding amount, adjusting the mold temperature, and performing injection molding. That is, the above-mentioned nylon MDX6 and nylon 6 are resins having a relatively low crystallization rate, and a skin layer of these resins is formed on the surface of the resin pipe by controlling the mold temperature and crystallizing relatively slowly. And the above glossiness can be achieved.

The temperature of the mold is appropriately adjusted according to the size of the resin pipe to be molded and other resins to be combined with the nylon MDX6 and nylon 6, and is not particularly limited. (Injection injection side ~
(Terminal side), particularly preferably 100 to 120 ° C., whereby a good skin layer made of the nylon MDX6 or nylon 6 can be formed and the surface glossiness can be adjusted to the above range. Incidentally, the photosensitive drum substrate of the present invention, the surface glossiness may be adjusted to the above range,
The adjustment method is not limited to this method.

The substrate for a photosensitive drum according to the present invention is, for example, shown in FIG.
The photosensitive layer 3 is formed on the surface similarly to the cylindrical substrate 1 shown in FIG.

In this case, in the photosensitive drum of FIG. 1, flanges 2a and 2b formed separately are fitted and fixed to both end surfaces of the cylindrical base 1. At least one of the flanges 2a and 2b is connected to the resin pipe. It can also be formed integrally with the cylindrical substrate 1 made of. Further, by adding the reinforcing inorganic filler, a molded product having excellent strength and rigidity can be obtained, so that the driving gear 6 can be integrally formed together with the flange.

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 resin pipe. The photosensitive layer is formed by coating with a known material and method. And the layer configuration may be a known configuration. Other configurations can be the same as those of a normal photosensitive drum.

[0028]

The present invention will now be described more specifically with reference to examples. Examples 1 to 4 and Comparative Examples 1 to 5 A resin composition having the composition shown in Table 1 was injection-molded under the conditions shown in the table to form a resin pipe. JIS for the obtained resin pipe
The 60 ° specular gloss of Z8741 was measured. Table 1 shows the results
Shown in The gloss was measured using a gloss meter “Gronometer VG2000” manufactured by Nippon Denshoku Industries Co., Ltd.

Further, a charge generation layer is coated on the outer peripheral surface of each of the obtained resin pipes using a paint obtained by dissolving a polyester resin containing a phthalocyanine pigment in chloroform, and further containing a hydrazone compound. The charge transporting layer was coated with a coating solution in which a polycarbonate resin was dissolved in chloroform to form a photosensitive layer having a thickness of 30 μm, thereby forming a photosensitive drum. The obtained photosensitive drum was mounted on a laser shot printer to perform image output, and the obtained image quality was evaluated. Table 1 shows the results.

[0030]

[Table 1] PA66: Nylon 66 (Mitsubishi Engineering Plastic “Novamid”) MDX6: Nylon MDX6 (Mitsubishi Engineering Plastic “Renny”) PA6: Nylon 6 (Ube Industries “UBE Nylon”) C / B: Carbon black (Lion “Ketjen Black”) )) Whisker: Potassium titanate whisker fiber (“Dentol” manufactured by Otsuka Chemical)

As shown in Table 1, the photosensitive drums having the resin pipes of Examples 1 to 4 each having an appropriate surface glossiness as a base can surely obtain good image quality. confirmed.

[0032]

As described above, according to the photosensitive drum substrate of the present invention, the image quality of the photosensitive drum can be improved by optimizing the surface glossiness.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a general configuration of a photosensitive drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical substrate (substrate for photosensitive drum) 2, 2a, 2b Flange 3 Photosensitive layer 4 Support shaft 5 Shaft hole 6 Drive gear

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H035 CA07 CB02 CB03 2H068 AA52 AA54 AA58 BB28 CA02 DA72 EA12 4J002 CL001 CL011 CL012 CL031 CL032 DA017 DA036 DL007 FA047 FD017 FD116 GQ00 GS00

Claims (6)

[Claims] 1. A substrate for a photosensitive drum, which is a pipe-shaped substrate made of a synthetic resin and has a surface glossiness of 12 to 30 according to JIS Z8741 at a 60-degree specular gloss. 2. The photosensitive drum substrate according to claim 1, comprising a resin composition containing a polyamide resin obtained from meta-xylylenediamine and adipic acid and / or a polyamide resin obtained from ε-caprolactam. 3. The compounding amount of the polyamide resin obtained from meta-xylylenediamine and adipic acid and / or the polyamide resin obtained from ε-caprolactam is 3 to 30% by mass of the resin component. The substrate for a photosensitive drum according to the above. 4. The photosensitive drum substrate according to claim 1, which is formed of a resin composition containing carbon black as a conductive agent. 5. The photosensitive drum substrate according to claim 1, comprising a resin composition containing a reinforcing inorganic filler. 6. A photosensitive drum obtained by coating a photosensitive layer on the outer peripheral surface of a cylindrical substrate, wherein the substrate for a photosensitive drum according to claim 1 is used as the cylindrical substrate. A photosensitive drum.