JPH10177266A - Substrate for electrophotographic photoreceptor and electrophotographic photoreceptor formed by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for an electrophotographic photoreceptor which is not affected in its electrophotographic characteristics in spite of the presence of some defects on the surface of a cylindrical base, facilitate the exchange of thermoplastic resin films and allows the repetitive use of a core material part. SOLUTION: This substrate is obtd. by coating the entire surface or part of the surface on the outer side of the cylindrical core material 1 made of glass with the thermoplastic insulating resin film and heat-treating this film at a temp. higher than the glass transition point of the resin constituting the film to form the thermoplastic insulating resin film layer 2 in tight contact with the surface of the cylindrical core material 1 and, further, forming a conductive layer 3 thereon. The cylindrical core material 1 which is made of the glass and has surface roughness Ra in a range of 0.15 to 0.35μm is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for an electrophotographic photoreceptor, and more particularly, to a method in which a photosensitive layer portion is deteriorated or damaged in spite of a good surface of the substrate.
The present invention relates to a base for an electrophotographic photoreceptor capable of easily separating a core material portion and an upper layer portion thereof and reusing the core material.

[0002]

2. Description of the Related Art Conventionally, when a cylindrical substrate is required in an electrophotographic photoreceptor, a cylinder obtained by subjecting a metal to a drawing process, an extrusion process, a drawing process, or the like is cut and used. However, the metal cylinder obtained by these methods has scratches, scours,
Burrs are likely to occur. Since a photoreceptor obtained using a substrate having such a defect cannot avoid image quality defects caused by the defect, the photoreceptor must be repaired in advance by cutting or polishing a defective portion on the surface of the substrate. However, such a method requires a great deal of effort,
It is also a factor of cost increase. Further, in order to reduce the cost of manufacturing the photoconductor, the substrate is reused. In this case, as a means for removing the photosensitive layer on the substrate,
The photosensitive layer is dissolved by mechanical cutting or immersion in a solvent. However, the substrate obtained by these methods inevitably suffers from cuts on the surface or partial remaining of the photosensitive layer. For this reason, image formation is performed using a photoconductor in which the photosensitive layer is again laminated on the substrate. If so, there is a problem that an image quality defect occurs.

[0003] To improve the above-mentioned problem, Japanese Patent Application Laid-Open Nos. 57-109955 and 4-32635 are disclosed.
Japanese Patent Application Laid-Open No. 8 (1999) -1995 discloses a photoconductor in which a cylindrical material made of a metal such as aluminum or a heat-resistant resin is used as a core material, a thermoplastic resin film is coated on the outer periphery, and a photosensitive layer is further formed on the outer peripheral surface. There has been proposed a photoreceptor substrate in which a core material can be reused by peeling the film and the photosensitive layer. However, the core material used for the electrophotographic photoreceptor substrate is required to have sufficient shape accuracy,
The production of a high-precision cylindrical body using a metal or resin molded article as a material is costly, and also has a problem that the core material surface is damaged by a blade or the like during the peeling operation, so that it cannot be reused.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances in the prior art. That is, an object of the present invention is to provide an inexpensive and reusable electrophotographic photoreceptor substrate and an electrophotographic photoreceptor using the same, by simply and easily regenerating a core material.

[0005]

The substrate for an electrophotographic photoreceptor of the present invention comprises a thermoplastic insulating resin film covering the entire surface or a part of the outer surface of a cylindrical glass core material. A heat treatment is performed at a temperature higher than the glass transition point of the resin to form a thermoplastic insulating resin film layer in close contact with the surface of the cylindrical core material, and a conductive layer is further formed thereon. As the glass cylindrical core material, the surface roughness of the core material is JIS B0601.
-Arithmetic mean roughness Ra defined in 1994
It is preferable to use one having a range of 0.35 μm. Further, the electrophotographic photoreceptor of the present invention is characterized in that a photosensitive layer is formed on the above substrate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The substrate for an electrophotographic photoreceptor of the present invention has a laminated structure as shown in FIG. 1, in which a thermoplastic insulating resin film layer 2 is in close contact with the outer surface of a glass cylindrical core material 1, Further, a conductive layer 3 is formed thereon. In the present invention, as the glass cylindrical core material, a glass selected from soda-lime glass, lead glass, borosilicate glass, and the like is formed by a mechanical drawing method such as a Danner method, an updraw method, or a downdraw method. It is used after being cut into a desired length after being formed into a diameter.

Since the dimensional accuracy of the electrophotographic photoreceptor base is determined by the glass core used in most cases, the outer diameter and cylindricity of the core itself are determined by the electrophotographic photoreceptor base. It is necessary to satisfy the required accuracy. For that purpose, the outer peripheral surface of the glass tube formed by the above-mentioned mechanical tube drawing method is centerlessly ground. This centerless grinding is a preferable method because it can be processed to a desired shape accuracy in a short time and a desired surface roughness can be obtained at the same time.

The substrate for an electrophotographic photosensitive member according to the present invention is characterized in that a portion formed on the outer surface of the core material is peeled off and the core material portion is reused. It is necessary that the formed thermoplastic insulating resin film layer be easily peeled off. Therefore, in the present invention, the glass cylindrical core material subjected to the centerless grinding has a surface roughness in the range of 0.15 to 0.35 μm in arithmetic average roughness Ra defined in JIS B0601-1994. It is preferable to use a material processed into The outer peripheral surface of the glass cylindrical core material processed to the roughness in this range does not weld or adhere to the core material when the adhered thermoplastic resin film is heated and shrunk, and is easily peeled off. Can be. When a core material having a roughness Ra smaller than the above-described roughness range is used, when the thermoplastic resin film is heated and shrunk and adhered to the outer periphery thereof, it may be welded or adhered. It is not easy to exfoliate. On the other hand, if a core material having a roughness larger than the above-mentioned roughness range is used, the surface properties of the electrophotographic photoreceptor finally produced are affected by the core material, and the photosensitivity is reduced. Image quality defects may appear in copied images obtained using the body.

In general, as a core material of a photoreceptor, a cylindrical body made of metal such as aluminum or stainless steel, a cylindrical body formed of a heat-resistant resin, a cylindrical body formed by processing paper with a resin, or the like is used. However, the substrate in the present invention may be made of glass from the viewpoints of the cost of the core material, that surface scratches are unlikely to occur when the resin is peeled off, and that mechanical strength and surface roughness are easily controlled. It is necessary to use a cylindrical core material made of aluminum.

Next, in the present invention, a cylindrical thermoplastic insulating resin film layer is formed in close contact with a part or all of the outer surface of the glass cylindrical core material. To adhere the thermoplastic resin film, after covering the thermoplastic resin film on the outer peripheral surface of the cylindrical core material, a temperature higher than the glass transition temperature of the thermoplastic resin constituting the film, preferably the resin used More than the glass transition temperature of
It is necessary to perform the heat treatment in a temperature range higher by 0 to 100 ° C. By this heat treatment, the cylindrical film can be contracted and easily adhered to the outer surface of the glass cylindrical core material.

The thermoplastic resin constituting the thermoplastic insulating resin film layer includes polyethylene terephthalate, polybutylene terephthalate, polyetherester copolymer, copolyester resin, polyetheramide, and the like.
At least one polymer selected from polyurethane, acrylic copolymer, polyolefin copolymer, olefin-based elastomer, styrene-based elastomer, polyvinyl chloride, and vinyl chloride copolymer is used.

Next, the thermoplastic insulating resin film layer 2
In order to form the conductive layer 3 on the outer peripheral surface, at least one metal selected from titanium, zirconium, aluminum, chromium, nickel and the like, or titanium oxide, indium oxide, tin oxide, zinc oxide, zirconium oxide And at least one metal oxide selected from tungsten oxide and the like, and may be laminated on the surface of the cylindrical thermoplastic resin film by an evaporation method, a sputtering method, an ion plating method, or the like. Alternatively, the conductive layer can be formed by applying a coating solution comprising at least one of the above metals or metal oxides, a binder resin and an organic solvent to the outer peripheral surface of the cylindrical film. As the coating method, a dip coating method, a spray coating method, a blade coating method, or the like is used.

The obtained conductive layer has a surface resistance of 10
Preferably of the ⁰ to 10 ¹² Omega range, more preferably in the range of 10 ^{0 ~10 6 Ω.} If the surface resistance value of the conductive layer is larger than this range, there arises a problem that a necessary image sensitivity cannot be obtained and a normal image cannot be obtained when an electrophotographic photosensitive member is mounted on an electrophotographic apparatus and printing is performed.

Some of the above-mentioned metals or metal oxides exhibit extremely high translucency even when a conductive layer is formed so as to satisfy the above-mentioned resistance value. The formed substrate is transparent to both the glass cylindrical core material and the thermoplastic resin film, so that it becomes a substrate for an electrophotographic photoreceptor having extremely excellent translucency. Such a translucent substrate is applicable to electrophotography in which light is irradiated from the transparent support side. In the electrophotographic process, each step of forming an electrostatic latent image by image exposure, development, transfer and cleaning is usually repeated.Erase exposure, a transfer step using light irradiation in combination, a charge removal step, In the cleaning step or pre-exposure, the photoconductor is irradiated with light. At this time, if the above-described light-transmitting substrate is used, at least one of the light irradiation steps can be performed from the light-transmitting substrate side of the photoconductor, so that the electrophotographic apparatus can be downsized. There is an advantage that it can be performed, for example, that static elimination exposure can be performed without using a toner.

According to the present invention, a photosensitive layer is formed on the surface of the substrate for an electrophotographic photosensitive member obtained by the above-mentioned method to produce an electrophotographic photosensitive member. Generally, an electrophotographic photosensitive member is used by being mounted inside an electrophotographic copying machine or a printer.
As the use is repeated, the photosensitive layer is replaced at a certain cycle due to abrasion and chemical deterioration of the photosensitive layer, surface scratches caused by handling and contact with other members, and the like. In addition, in order to form a photosensitive layer on a substrate for an electrophotographic photosensitive member, a dip coating method, a spray coating method, or the like is generally used, but it is difficult to eliminate coating film defects generated in these steps. Actually, after the photosensitive layer forming step, a step of inspecting the presence or absence of a coating film defect and selecting a non-defective product is actually provided. The photoreceptor in which a coating film defect is found in this sorting process is discarded, or the photoreceptor layer is peeled off through a large number of steps mechanically or chemically, and the substrate is regenerated and reused. In both cases, cost increases are inevitable.

However, in the photoreceptor using the electrophotographic photoreceptor substrate of the present invention, the thermoplastic insulating resin film adhered to the outside of the glass core material and the portion outside the same are easily peeled off. Only the core material can be reused. The film can be peeled off by a very easy means such as making a cut on an arbitrary portion of the surface of the photoreceptor with a knife or the like and peeling the resin film therefrom. At this time, since the core material is made of glass, it can be reused many times without surface damage by a knife or the like.

[0017]

【Example】

Example 1 (Preparation of substrate for electrophotographic photoreceptor) After borosilicate glass was mechanically drawn by a down-draw method, it was cut with a grindstone to obtain an outer diameter of 29.
A glass tube having a thickness of 8 mm, a thickness of 2.2 mm, and a length of 253 mm was prepared. The surface of the glass tube was ground by an infeed centerless processing machine to obtain a glass cylindrical core material having a cylindricity of 15 μm and a surface roughness Ra of 0.28 μm. A 55 μm-thick polyethylene terephthalate film (glass transition temperature: 78 ° C.) was put on the outer surface of this core material,
When the film was heated at 0 ° C. for 30 minutes, the film shrunk, and a glass core material having a polyethylene terephthalate film adhered to the outer peripheral surface thereof was obtained. Next, a conductive paint (ELCOM P353) in which a metal oxide containing tin oxide as a main component is dispersed on the surface of the obtained film film.
0, manufactured by Kasei Kagaku Kogyo Co., Ltd.) by dip coating using a coating solution diluted with a mixed solvent of toluene and methyl ethyl ketone (weight ratio: 1: 1), and dried by heating at 120 ° C. for 10 minutes. A substrate for an electrophotographic photosensitive member was prepared by forming a conductive layer having a thickness of 2.5 μm. The surface resistance of this conductive layer was 2.5 × 10 ⁴ Ω.

(Preparation of Electrophotographic Photoreceptor) Using the substrate obtained by the above method, an electrophotographic photoreceptor was prepared as follows. First, 10 parts by weight of an organic zirconium compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
A mixed solution consisting of 1 part by weight of a silane coupling agent (trade name: A1110, manufactured by Nippon Unicar Co., Ltd.), 40 parts by weight of isopropyl alcohol, and 20 parts by weight of n-butyl alcohol is prepared and applied to the surface of the substrate by a dip coating method. did. Thereafter, the resultant was placed in a dryer and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.1 μm. next,
A mixture comprising 15 parts by weight of an x-type metal-free phthalocyanine as a charge generating substance, 10 parts by weight of a polyvinyl butyral resin (trade name: Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 300 parts by weight of n-butyl alcohol was mixed with a sand mill. Time-dispersed. The resulting dispersion was dip-coated on the undercoat layer to form a 0.2 μm-thick charge generation layer. Further, N, N'-diphenyl-N, N'-bis (3
-Methylphenyl)-[1,1'-biphenyl] -4,
4 parts by weight of 4'-diamine and poly (4,4 '
-Cyclohexylidene diphenylene carbonate) and 6 parts by weight of polycarbonate were added to and dissolved in 80 parts by weight of monochlorobenzene. The obtained solution was applied on the charge generation layer, and dried by heating at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 22 μm.
An electrophotographic photoreceptor having a three-layer structure was produced.

(Evaluation of Substrate) The obtained electrophotographic photosensitive member was applied to a laser beam printer (Laser Press 410).
5, Fuji Xerox Co., Ltd.) and good image quality was obtained. In this state, 20,000 print tests were continuously performed. Thereafter, the electrophotographic photoreceptor was removed, a cut was made in one end of the photosensitive layer and one end of the thermoplastic resin film with a cutter knife and peeled off, and a glass core material was taken out.

The glass core material was subjected to ultrasonic cleaning with pure water containing a surfactant, then rinsed with pure water, and dried. Using this recycled glass core material, an electrophotographic photoreceptor was produced again in exactly the same manner as described above.
The characteristics were completely equivalent to those of the electrophotographic photosensitive member produced first.

Comparative Example 1 A substrate for an electrophotographic photosensitive member was prepared in exactly the same manner as in Example 1 except that a cylindrical core material made of aluminum was used. Was formed to produce an electrophotographic photosensitive member. When the same peeling operation as in Example 1 was attempted on the obtained photoreceptor, the surface of the aluminum core was scratched when a cut was made with a cutter knife during the peeling, and this core was repeatedly used. Was impossible.

Example 2 From a substrate for an electrophotographic photosensitive member produced in the same manner as in Example 1, the thermoplastic resin film was peeled off using a cutter knife. The obtained glass core material was wiped and cleaned with a dust-free cloth containing a methyl ethyl ketone solvent, and then a thermoplastic insulating resin film layer and a conductive layer were formed in the same procedure as in Example 1 to form an electrophotographic photosensitive member. A substrate for use was produced. When this operation was repeated 15 times, the surface roughness Ra of the glass core material was 0.27 μm, and the cylindricity was 16 μm.
μm, and there was no change from the initial stage. When the surface of the core material was observed, no defect such as a shrinkage of the thermoplastic resin film or a defect caused by a peeling operation was found at all.

Example 3 A substrate for an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that a glass core having a surface roughness Ra of 0.08 μm was used. Produced. In the same manner as in Example 1, when a cut was made on one end of the photosensitive layer and the thermoplastic resin film with a cutter knife to attempt a peeling operation, most of the thermoplastic resin film could be peeled off. The portion adhered to the core material surface and could not be completely removed. However, when the adhered portion was washed while wiping using a dust-free cloth containing methyl ethyl ketone, a glass core material from which almost no thermoplastic resin film had been removed could be taken out. The obtained glass core material was reusable as a substrate for an electrophotographic photosensitive member.

Example 4 A substrate for an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that a glass cylindrical core having a surface roughness Ra of 0.48 μm was used. Made,
Further, a photosensitive layer was formed in the same manner to prepare an electrophotographic photosensitive member. When an image was formed using the obtained electrophotographic photoreceptor in the same manner as in Example 1, good image quality was obtained.
At the time of the first round, slight image quality defects considered to be due to irregularities on the surface of the core material were found in some parts, but 100%.
There was no practical problem in the print test of 00 sheets. Further, this glass core material was obtained in Example 3.
In the same manner as in Example 1, it could be reused as a substrate for an electrophotographic photosensitive member.

[0025]

The substrate for an electrophotographic photoreceptor of the present invention is obtained by adhering a thermoplastic resin film to the surface of a glass cylindrical core material, so that the surface of the cylindrical core material has some defects. Even without changing the electrophotographic properties, the glass core material can be easily used repeatedly by exchanging the coating made of the thermoplastic resin film on the cylindrical core material. Become. In addition, when a conductive layer having excellent translucency is selected, a light irradiation process such as static elimination or exposure can be performed from the inside of the substrate when the electroconductive layer is mounted in the electrophotographic apparatus. Can contribute.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a laminated structure of a substrate for an electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

Reference numeral 1 denotes a glass cylindrical core material, 2 denotes a thermoplastic insulating resin film layer, and 3 denotes a conductive layer.

Claims (3)

[Claims] 1. An entire surface or a part of an outer surface of a glass cylindrical core material is coated with a thermoplastic insulating resin film, and heat-treated at a temperature higher than a glass transition point of a resin constituting the film. A substrate for an electrophotographic photosensitive member, comprising: forming a thermoplastic insulating resin film layer in close contact with the surface of a cylindrical core material; and further forming a conductive layer thereon. 2. The surface roughness of a glass cylindrical core material is JI
Arithmetic mean roughness R defined in SB0601-1994
2. The substrate for an electrophotographic photosensitive member according to claim 1, wherein a is in the range of 0.15 to 0.35 [mu] m. 3. An electrophotographic photoreceptor comprising a photosensitive layer formed on the electrophotographic photoreceptor substrate according to claim 1 or 2.