JP2002311624A - Substrate for photosensitive drum and photosensitive drum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive drum which is excellent in dimensional accuracy and is capable of forming images having excellent image quality free of unevenness and a substrate for the photosensitive drum adequate for this photosensitive drum. SOLUTION: This substrate for the photosensitive drum contains a resin, is rotatable and is <=80 μm in out of roundness. The form that the out of roundness is <=50 μm, the form that the resin contains a polyamide resin, the form that the resin contains an aliphatic polyamide resin, the form that the resin contains inorganic fillers, etc., are more preferable. This photosensitive drum has at least a photosensitive layer on the substrate for the photosensitive drum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a photosensitive drum used in an electrophotographic apparatus or an electrostatic recording apparatus, and a photosensitive drum base suitable for the photosensitive drum.

[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 uniformly charged, and an image is projected from an optical system onto the surface of the photosensitive drum and light is applied to the portion. Forming an electrostatic latent image by erasing the charge of the toner, and then supplying toner to the electrostatic latent image to form a toner image by electrostatic adhesion of the toner, and forming the toner image on paper, OHP, photographic paper, etc. The image is transferred to a recording medium to form an image.

[0003] In a photosensitive drum used in such an electrostatic recording process, a drum base is conventionally made of an aluminum alloy in a cylindrical shape because of its relatively light weight, excellent machinability, and good conductivity. -A drum base processed into a cylindrical shape is used. In recent years, as an alternative to the aluminum alloy drum base, a resin such as a thermoplastic resin, a drum base processed from a composite material based on the resin, and the like have been used.

Here, in the electrostatic recording process, since an image is formed on a recording medium by rotating a cylindrical / columnar drum base, the drum base is required to have excellent dimensional accuracy and the like. Have been.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to meet the above-mentioned various demands in the prior art and achieve the following objects. That is, an object of the present invention is to provide a photosensitive drum which is capable of forming an image having excellent dimensional accuracy and excellent image quality without unevenness, and a photosensitive drum base suitable for the photosensitive drum.

[0006]

Means for solving the above problems are as follows. That is, <1> contains a resin, is rotatable, and has a straightness of 8
A photosensitive drum base having a thickness of 0 μm or less. <2> The photosensitive drum substrate according to <1>, wherein the straightness is 50 μm or less. <3> The resin according to <1>, wherein the resin contains a polyamide resin.
> Or <2>.

<4> The photosensitive drum substrate according to any one of <1> to <3>, wherein the resin contains an aliphatic polyamide resin. <5> The photosensitive drum substrate according to any one of <1> to <4>, further including an inorganic filler. <6> A photosensitive drum having at least a photosensitive layer on the photosensitive drum substrate according to any one of <1> to <5>.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Substrate for Photosensitive Drum] The substrate for photosensitive drum of the present invention contains a resin and, if necessary, other components.

The photosensitive drum substrate must be rotatable and have a straightness of not more than 80 μm, preferably not more than 50 μm, and more preferably not more than 30 μm. When the straightness exceeds 80 μm, the dimensional accuracy is poor, the image quality is excellent, and an image without unevenness cannot be formed.

The straightness of the photosensitive drum substrate determines the accuracy of the roller gap with the charger in the image forming process, and greatly affects the uniformity of the surface potential of the photosensitive drum and the image printing performance. give. In the present invention, the type of resin to be contained in the photosensitive drum substrate, adjustment of the amount, the use of a filler, etc., by controlling the straightness within the above numerical range, good dimensional accuracy, excellent image quality, A photosensitive drum capable of forming an image without unevenness is provided.

The straightness is a scale representing a geometrical tolerance as described in JIS B0021, and was measured and calculated as follows. A substrate for a photosensitive drum is arranged substantially parallel to a reference edge having high linear accuracy, and a distance between the reference edge and the substrate is measured in a length direction using a laser scan micrometer and a transmitter. The obtained data was plotted to create a graph, and a reference line in contact with both ends was drawn, and the maximum value from the reference line was defined as straightness.

The photosensitive drum substrate may be lighter,
It is necessary to contain a resin in terms of reduction in driving power and the like. The resin is preferably a conductive resin composition, and the resin substrate constituting the conductive resin composition is not particularly limited, but is preferably a thermoplastic resin. As the thermoplastic resin, all known resin materials conventionally used for a substrate for a photosensitive drum are suitably mentioned, and in particular, the resin has good surface smoothness for forming a photosensitive layer, and Polyamide-based resins such as various nylons are preferable in terms of excellent chemical resistance and mechanical strength. Examples of the polyamide resin include an aromatic polyamide resin and an aliphatic polyamide resin, and an aliphatic polyamide resin is particularly preferable.
As the polyamide resin, for example, nylon 11,
Nylon 12, Nylon 46, Nylon 6, Nylon 6
6, nylon MXD6, nylon 610, nylon 61
2, nylon 1212, and copolymers thereof. These may be used alone or in combination of two or more. Among these, nylon 6 and nylon 66 are preferable as the aliphatic polyamide-based resin, and nylon MXD6 and the like are preferable as the aromatic polyamide-based resin in terms of more excellent dimensional stability and moldability.

It is preferable that a non-hygroscopic resin is used in combination with the polyamide resin or the like in the photosensitive drum substrate in order to suppress a dimensional change or the like due to moisture absorption. Examples of the non-hygroscopic resin include polypropylene, polyphenylene ether, polyphenylene sulfide, and the like. It is preferable that these non-hygroscopic resins are appropriately selected in consideration of the compatibility with the polyamide resin and the like.

In general, the conductive resin composition is obtained by adding a conductive agent to the resin base material to impart conductivity. The conductive agent is not particularly limited as long as it can be uniformly and suitably dispersed in the resin substrate, and examples thereof include carbon black, graphite, aluminum, copper, metal powder such as nickel, and conductive glass powder. Particularly, carbon black is preferable. The content of the conductive agent in the conductive resin composition is not particularly limited;
% By weight, more preferably 5 to 20% by weight. Further, by including the conductive agent, the surface resistance of the substrate is preferably set to 10 ⁴ Ω / □ (ohm / square) or less, more preferably 10 ² Ω / □ or less.

The base for the photosensitive drum may contain an inorganic filler such as various fibers, if desired, for the purpose of reinforcing and increasing the amount. Examples of the inorganic filler include conductive fibers such as carbon fibers, conductive whiskers, and conductive glass fibers, and non-conductive fibers such as whiskers and glass fibers. Since the conductive fiber can also act as a conductive agent, the amount of the conductive agent such as the carbon black can be reduced by using the conductive fiber.

The amount of the inorganic filler is not particularly limited, and is appropriately selected depending on the kind of the inorganic filler, the length and the diameter of the fiber, and the like. 1 to 30% by weight is preferable, 5 to 25% by weight is more preferable, and 10 to 25% by weight is further preferable.

The conductive resin composition may include, if desired, polytetrafluoroethylene (PTFE), silicone, molybdenum disulfide (Mo), in addition to the inorganic filler.
S ₂ ), known additives such as various metal soaps can be added in appropriate amounts. The conductive agent, the inorganic filler, and the like may be subjected to a surface treatment using a silane coupling agent, a titanate coupling agent, or the like that is generally used.

The shape of the photosensitive drum substrate is preferably a cylindrical shape, a cylindrical shape, or the like, since an image can be easily formed on a recording medium by rotation. The method for molding the photosensitive drum substrate is not particularly limited, and examples thereof include an injection molding method,
Although an extrusion molding method is mentioned, an injection molding method is particularly preferable. Molding conditions such as molding temperature and injection pressure are appropriately selected according to the type of the resin component constituting the base.

[Photosensitive Drum] The photosensitive drum of the present invention has a photosensitive layer on the substrate for a photosensitive drum of the present invention, and has other layers as necessary.

-Photosensitive Layer- The photosensitive layer preferably has at least a charge generation layer and a charge transport layer.

--Charge Generating Layer-- The charge generating layer preferably contains a charge generating compound and a binder resin.

The charge generating compound is not particularly limited, and may be appropriately selected from known compounds used in the charge generating layer of a photoreceptor.
Organic conductive compounds and the like can be mentioned. Among these,
Compounds and the like having high charge generating ability are preferred. The binder resin is not particularly limited, and is appropriately selected from known resins conventionally used for a charge generation layer of a photoconductor. The charge generation layer can be formed by a known method such as coating and vapor deposition.

--Charge Transport Layer-- The charge transport layer preferably has a non-uniform charge transport layer and a uniform charge transport layer.

The heterogeneous charge transport layer is not particularly limited, but is preferably a particle-dispersion type heterogeneous charge transport layer, a phase separation type heterogeneous charge transport layer, or the like. The heterogeneous charge transport layer,
The material to be contained in the heterogeneous charge transport layer, such as a polymer material, can be dispersed in a solvent and formed by a known method such as coating.

The uniform charge transport layer is not particularly limited, but preferably contains a polymer compound having high charge transport ability and excellent film formability. The uniform charge transport layer can be formed by dispersing a material to be contained in the uniform charge transport layer, such as the polymer material, in a solvent, and by a known method such as coating.

-Other layers- Examples of the other layers include an undercoat layer and a protective layer.

[0027]

The present invention will be described in more detail with reference to the following examples and comparative examples. However, the present invention is not limited to the following examples.

(Examples 1 to 3 and Comparative Examples 1 to 3) Substrates for photosensitive drums having the composition ratios shown in Table 1 were prepared (cylindrical, dimensions: 24 mm (φ) × 260 mm), and then evaluated by the following evaluation methods. The straightness of the photosensitive drum substrate was measured and evaluated. Table 1 shows the results.

<Straightness evaluation method> JIS B0021
In accordance with the above, the photosensitive drum substrate is disposed substantially parallel to a reference edge having high linear accuracy, and the distance between the reference edge and the substrate is set in the length direction using a laser scan micrometer and a transmitter. The measured data was plotted to create a graph, and a reference line was drawn at both ends, and the maximum value from the reference line was defined as straightness.

Thereafter, a thickness of 3 mm is applied to the photosensitive drum substrate.
A photosensitive layer having a thickness of 0 μm was formed to produce a photosensitive drum, and image characteristics were evaluated by the following evaluation methods. <Method of evaluating image characteristics (printing performance)> The photosensitive drum was mounted on a laser shot printer, an image was formed, and the image quality was visually evaluated. Table 1 shows the results.

[0031]

[Table 1]

In Table 1, "PA66" is nylon 66 ("UBE nylon" manufactured by Ube Industries, Ltd.),
"PA6" is made of nylon 6 ("UBE" manufactured by Ube Industries, Ltd.)
Nylon ") and" PAMXD6 "are polyamide MXD
6 (“Toyobo Nylon T600” manufactured by Toyobo Co., Ltd.)
“C / B” is carbon black (“Ketjen Black” manufactured by Lion Corporation), and “whisker” is potassium titanate whisker (“Tismo” manufactured by Otsuka Chemical Co., Ltd.).

From Examples and Comparative Examples, in Examples 1 to 3,
It can be seen that the straightness value is small and the image characteristics are good.

[0034]

According to the present invention, it is possible to provide a photosensitive drum capable of forming an image having excellent dimensional accuracy and excellent image quality without unevenness, and a photosensitive drum base suitable for the photosensitive drum.

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Claims (6)

[Claims] 1. A photosensitive drum base comprising a resin, rotatable and having a straightness of 80 μm or less. 2. The straightness is 50 μm or less.
3. The substrate for a photosensitive drum according to item 1. 3. The photosensitive drum substrate according to claim 1, wherein the resin contains a polyamide resin. 4. The substrate for a photosensitive drum according to claim 1, wherein the resin contains an aliphatic polyamide-based resin. 5. The substrate for a photosensitive drum according to claim 1, further comprising an inorganic filler. 6. A photosensitive drum having at least a photosensitive layer on the photosensitive drum substrate according to claim 1.