JP2003330208A - Method for manufacturing photosensitive drum base body, and photosensitive drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a photosensitive drum base body having a base coating layer with excellent surface smoothness on the drum surface in a short period of time at a low cost without giving adverse influences on the work environment and to provide a photosensitive drum which uses the above photosensitive drum base body. <P>SOLUTION: The method for manufacturing a photosensitive drum base body comprising a conductive resin composition to be used for a photosensitive drum for electrophotographic processes includes a process of forming a base coating layer by in-mold coating during a conductive resin composition is injection molded. After the conductive resin composition is injected into dies equipped with an injecting machine of a coating material and the conductive resin composition is cured or half cured, the coating material for in-mold coating is injected and cured. <P>COPYRIGHT: (C)2004,JPO

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 photosensitive drum substrate having an undercoat layer on the surface thereof, which is used for a photosensitive drum for an electrophotographic process, and a photosensitive drum using the photosensitive drum substrate. More specifically, the present invention has no adverse effect on the work environment, and is short-time, low-cost,
The present invention relates to a method for producing a photosensitive drum substrate having an undercoat layer having excellent surface smoothness, and a photosensitive drum using the photosensitive drum substrate.

[0002]

2. Description of the Related Art In an electrostatic recording process in an electrophotographic apparatus such as a copying machine, a facsimile, a printer or an electrostatic recording apparatus, first of all, a photoconductive substance [eg ZnO, CdS, Se, OPC (organic semiconductor) is generally used. , Amorphous silicon (a-Si), etc.] is uniformly charged on the surface of the photosensitive drum, and an image is projected from the optical system onto the surface of the photosensitive drum to erase the electrostatic charge on the exposed portion of the electrostatic latent image. An image is formed, then toner is supplied to the electrostatic latent image to electrostatically adhere the toner to form a toner image, which is transferred to a recording medium such as paper, OHP, photographic paper or the like to form an image. The method of doing is adopted.

A photosensitive drum used in such an electrostatic recording process has a photosensitive layer formed by applying a photosensitive agent coating film in which a photosensitive agent is dispersed on a photosensitive drum substrate. Conventionally, as the photosensitive drum base, a photosensitive drum base formed by processing an aluminum alloy into a cylindrical shape or a cylindrical shape has been used because it is relatively lightweight, excellent in machinability, and has good conductivity. In recent years, as an alternative to the aluminum alloy base, it is also possible to use a photosensitive drum base formed by injection-molding a conductive resin in which a conductive agent such as carbon black is mixed and dispersed in a thermoplastic resin such as polyamide resin. It is being appreciated.

Further, in the photosensitive drum, as shown in FIG. 1, the undercoat layer 3 is provided between the photosensitive drum base 1 and the photosensitive layer 2.
Is generally formed. This undercoat layer is intended to prevent injection of unnecessary charges from the photosensitive drum substrate, protect the photosensitive layer from discharge breakdown due to concentration of charges, correct surface defects of the photosensitive drum substrate, and improve the adhesion of the photosensitive layer. Examples of the material include polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide and the like, and in some cases powders of titanium oxide, zinc oxide, silica, alumina, magnesium oxide, zirconium oxide and the like are dispersed. The conventional method for forming the undercoat layer is to dissolve the above-mentioned materials in an appropriate organic solvent, apply the solution on the surface of the photosensitive drum substrate, and dry it to form 0.5-5 μm
Although an undercoating layer having a film thickness of about m is formed, there are problems that it takes a long time for the drying step, the working environment is deteriorated due to the use of the organic solvent, and foreign matter adheres.

[0005]

Under the circumstances, the inventors of the present invention have solved the problems of the conventional method, have no adverse effect on the working environment, and are short-term, low-cost, and have surface smoothness. It is an object of the present invention to provide a method for producing a photosensitive drum substrate having an excellent undercoat layer on the surface, and a photosensitive drum using the photosensitive drum substrate.

[0006]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that when a photosensitive drum substrate is manufactured by injection molding of a conductive resin composition, It was found that the purpose can be achieved by forming an undercoat layer with. The present invention has been completed based on such findings. That is, the present invention is a method for producing a photosensitive drum substrate made of a conductive resin composition for use in a photosensitive drum for an electrophotographic process, which comprises undercoating by in-mold coating when the conductive resin composition is injection-molded. Provided is a method for producing a photosensitive drum substrate, which is characterized by forming layers, and a photosensitive drum using the photosensitive drum substrate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In-mold coating in the method for manufacturing a photosensitive drum substrate according to the present invention, a mold 4 is provided with a paint pouring machine as shown in FIG.
This is a method in which a paint for in-mold coating is filled inside, a resin material is injected into a mold, the resin material is cured or semi-cured, and then the paint for in-mold coating is injected and cured. The paint for in-mold coating used in the present invention is not particularly limited as long as it provides the function as the undercoat layer as described above,
For example, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein,
There are polyamides, and those having powders of titanium oxide, zinc oxide, silica, alumina, magnesium oxide, zirconium oxide, etc. dispersed therein can also be mentioned. Among these, polyamides are preferable, and alcohol-soluble polyamides are particularly preferable, from the viewpoints of adhesion to the drum substrate, solvent resistance to the photosensitive layer as the overcoat layer, and the like. It should be noted that the in-mold coating paint should not be cured before the shape of the photosensitive drum substrate is formed, and it is not preferable that it has fluidity when the mold is completely opened. The molding conditions such as the type of paint for in-mold coating, molding temperature and injection pressure are selected in consideration of the characteristics of the resin composition.

The base resin of the conductive resin composition used for the photosensitive drum substrate is not particularly limited, and for example, polyamide resins such as nylon 6 and nylon 66, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. The polyester resin can be mentioned. Further, as the low hygroscopic resin, for example, polypropylene, polyphenylene ether,
Polyphenylene sulfide and the like can also be added. Among these, polyamide-based resins and polyester-based resins are particularly preferable from the viewpoints of physical properties, moldability, cost and the like.

The conductive agent used in the conductive resin composition is not particularly limited as long as it can be uniformly dispersed in the resin component, and examples thereof include carbon black, graphite, and metals such as aluminum, copper and nickel. powder,
Conductive glass powder and the like can be mentioned, among which physical properties,
Carbon black is particularly preferable in terms of handleability and cost.

Ion conductive materials can also be used as conductive agents. Examples of the ion conductive material include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium and lauryltrimethylammonium, octadecyltrimethylammonium such as hexadecyltrimethylammonium and stearyltrimethylammonium, ammonium such as benzyltrimethylammonium and modified aliphatic dimethylethylammonium. Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulphates, alkylsulfates, carboxylates, sulphonates and other organic ionic conductive materials and lithium, Alkali metal or alkaline earth metal perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, trifluoromethyl sulphates, etc. of sodium, calcium, magnesium, etc. It can be exemplified inorganic ion conductive material such as Hong salt.

The content of this conductive agent is 10
It is preferably 5 to 40 parts by weight, more preferably 20 to 35 parts by weight, relative to 0 parts by weight. When the amount of the conductive agent is too large, mechanical properties such as impact strength are likely to deteriorate, and when the amount is too small, desired conductivity may not be exhibited.

The conductive resin composition contains various additives such as polyester elastomer (polyester-polyether copolymer) and polyolefin elastomer (ethylene-propylene terpolymer) as impact modifiers. It is also possible to use various elastomers and additives such as metal soaps such as sodium stearate and sodium montanate as fluidity improvers, and amide lubricants such as stearic acid amides and alkyl bisamides. If the additive amount of these additives is too large, mechanical properties such as water absorption, chemical resistance, flexural modulus, impact strength and the like of the obtained photosensitive drum substrate may be deteriorated.
Addition in the range of 0 to 50 parts by weight, particularly 0 to 20 parts by weight is preferable with respect to parts by weight.

If desired, the conductive resin composition may contain fillers such as various fibers and whiskers. Examples of the filler include conductive fibers such as carbon fibers, conductive whiskers and conductive glass fibers, and non-conductive fibers such as whiskers and glass fibers. In particular, from the viewpoint of emphasizing improvement in elastic modulus and strength, as the reinforcing material, fibrous calcium silicate, potassium titanate,
Inorganic fillers such as whiskers and fibers typified by silicon carbide, silicon nitride, magnesium oxide, potassium titanate, aluminum hydroxide and the like can be used. Of these, a fibrous filler of calcium silicate is preferable. Here, calcium silicate as the fibrous filler can be obtained, for example, as “wollastonite”. This "Wollastonite" is made by crushing and refining wollastonite, which is a natural mineral, and has an average fiber diameter of 6 to 2
It has a fine fibrous shape of 5 μm and is a white powder. In addition, the above-mentioned inorganic filler can be used by surface-treating it with a silane coupling agent such as aminosilane, epoxysilane, ureidosilane, vinylsilane or a titanate coupling agent so as to enhance the affinity with the resin. .

The amount of the above-mentioned filler compounded is not particularly limited and may be appropriately selected depending on the type of the filler, the length and diameter of the fiber, etc., but is preferably based on 100 parts by weight of the resin content. It is selected in the range of 10 to 50 parts by weight, more preferably 25 to 45 parts by weight. When the amount of the filler is too large, the mechanical properties such as impact strength may be deteriorated, and when the amount of the filler is too small, the mechanical properties such as bending strength and flexural modulus may be deteriorated.

The photosensitive drum of the present invention is mounted on the above-mentioned high-speed image forming apparatus, and comprises the photosensitive drum substrate of the present invention, preferably a photosensitive layer, and optionally other layers such as a protective layer. And so on. The photosensitive layer preferably has at least a charge generation layer and a charge transport layer. Here, the charge generation layer is preferably composed of a charge generation compound and a binder resin.
The charge generating compound is not particularly limited, and conventionally,
It is appropriately selected from known compounds used for the charge generation layer of the photoconductor, and various inorganic conductive compounds, organic conductive compounds and the like can be mentioned. Among these, compounds having high charge generation ability are preferable. The binder resin is not particularly limited and is appropriately selected from known resins conventionally used for the charge generation layer of a photoreceptor. This charge generation layer can be formed by a known method such as coating or vapor deposition.

On the other hand, the charge transport layer preferably has a non-uniform charge transport layer and a uniform charge transport layer. The non-uniform charge transport layer is not particularly limited, but may be a particle dispersion type non-uniform charge transport layer or a non-uniform charge transport layer. , A phase-separated heterogeneous charge transport layer and the like are preferable. The non-uniform charge transport layer, a material such as a polymer material to be contained in the non-uniform charge transport layer is dispersed in a solvent,
It can be formed by a known method such as coating. The uniform charge transport layer is not particularly limited, but a layer containing a polymer compound having high charge transport ability and excellent film forming property is preferable. The uniform charge transport layer can be formed by dispersing a material, such as the polymer material, contained in the uniform charge transport layer in a solvent, by a known method such as coating.

[0017]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 50 parts by weight of polyamide 66 resin [trade name "Ube nylon 2015B" manufactured by Ube Industries Ltd.), polyamide 6 resin [trade name "Ube nylon 1013 manufactured by Ube Industries Ltd."
B "] 50 parts by weight, furnace carbon black [Asahi Carbon Co., Ltd., trademark" Asahi AX-015 "] 28 parts by weight and fibrous calcium silicate [Kawatetsu Mining Co., Ltd., trademark" Wollastonite "]" A photosensitive drum substrate (diameter: 30 mm, length: 260 mm) was molded by injection molding using a conductive resin composition composed of 35 parts by weight, and at the same time, an alcohol-soluble polyamide [trade name "Amilan CM-8000" manufactured by Toray Industries, Inc. ]] Was used to form an undercoat layer having a film thickness of 1 μm.
Injection molding cylinder temperature 280 ℃, mold temperature 90
After setting the temperature to ℃, injection molding the above conductive resin composition,
The paint for in-mold coating set at 0 ° C. was poured and held for 1 minute, then the mold was opened and the molded product was taken out. As a result, it was confirmed that a photosensitive drum substrate having an undercoating layer having no coating failure and excellent surface smoothness could be obtained continuously and stably in a short time.

Example 2 As a conductive resin composition, 100 parts by weight of polybutylene terephthalate resin [manufactured by Polyplastics Co., Ltd., trademark "Duranex 2002"], furnace carbon black [manufactured by Asahi Carbon Co., Ltd., trademark " Asahi AX-01
5 "] 26 parts by weight and fibrous calcium silicate [manufactured by Kawatetsu Mining Co., Ltd., trademark" Wollastonite "] 25 parts by weight, except that a conductive resin composition was used. Carried out. As a result, a photosensitive drum substrate having an undercoat layer with excellent surface smoothness without coating defects,
It was confirmed that it was possible to continuously and stably obtain in a short time.

[0019]

According to the present invention, it is possible to manufacture a photosensitive drum substrate having an undercoat layer having excellent surface smoothness on the surface thereof, which has no adverse effect on the environment, can be produced in a short time at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a photosensitive drum.

FIG. 2 is a cross-sectional view showing an example of an in-mold coating device.

[Explanation of symbols]

1 Photosensitive drum substrate 2 Photosensitive layer 3 subbing layer 4 mold 5 Resin molded products 6 Paint injection machine for in-mold coating

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kunio Machida             3-1-1 Ogawa Higashi-cho, Kodaira-shi, Tokyo Stock market             Bridgestone Technology Center F-term (reference) 2H068 AA43 AA52 BB23 BB28 CA02                       CA54 EA07 EA18

Claims (8)

[Claims] 1. A method for producing a photosensitive drum substrate made of a conductive resin composition for use in a photosensitive drum for an electrophotographic process, which comprises undercoating by in-mold coating when the conductive resin composition is injection-molded. A method for manufacturing a photosensitive drum substrate, which comprises forming a layer. 2. A conductive resin composition is injected into a mold equipped with a paint injecting machine, the conductive resin composition is cured or semi-cured, and then a paint for in-mold coating is injected and cured. The method for manufacturing a photosensitive drum substrate according to claim 1. 3. The method for producing a photosensitive drum substrate according to claim 1, wherein the undercoat layer has a thickness of 0.5 to 5 μm. 4. The undercoat layer is made of polyamide.
4. The method of manufacturing a photosensitive drum substrate according to any one of 3 to 3. 5. The method for producing a photosensitive drum substrate according to claim 1, wherein a conductive resin composition containing a polyamide resin or a polyester resin as a base resin is used. 6. The method for producing a photosensitive drum substrate according to claim 1, wherein a conductive resin composition containing carbon black as a conductive agent is used. 7. The method for producing a photosensitive drum substrate according to claim 1, wherein a conductive resin composition containing an inorganic filler is used. 8. A photosensitive drum formed by forming a photosensitive layer on a photosensitive drum substrate manufactured by the method according to claim 1.