JPS5997151A - electrophotographic photoreceptor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to an electrophotographic photoreceptor.

Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied. 2. Description of the Related Art As typical electrophotographic photoreceptors, there are photoreceptors in which a photoreceptor layer is formed on a substrate, and photoreceptors in which a photoreceptor layer is laminated with an insulating layer thereon, which are widely used. A photoreceptor composed of a substrate and a photosensitive layer is used for image formation by the most common electrophotographic processes, ie, charging, image exposure, development, and, if necessary, transfer. In addition, for photoreceptors equipped with an insulating layer, this insulating layer can be used to protect the photoreceptor, improve the mechanical strength of the photoreceptor, improve dark decay characteristics, or be applied to certain electrophotographic processes. It is established for this purpose. Typical examples of photoreceptors having such insulating layers or electrophotographic processes using such photoreceptors include, for example,
U.S. Patent No. 2860048, Japanese Patent Publication No. 41-164
Publication No. 29, Special Publication No. 38-15446, Special Publication No. 4
Publication No. 6-3713, Japanese Patent Publication No. 42-23910,
Special Publication No. 43-24748, Special Publication No. 42-1974
It is described in Japanese Patent Publication No. 7, Japanese Patent Publication No. 36-4121, etc.

A predetermined electrophotographic process is applied to the electrophotographic photoreceptor to form an electrostatic image, and this electrostatic image is developed and visualized.

By the way, the substrate of an electrophotographic photoreceptor only needs to have mechanical strength and conductivity, and conventionally aluminum,
Metals such as copper, zinc, soot, gold, stainless steel, brass, palladium, vanadium, chromium, and titanium, or glass sheets on which these metals are vapor-deposited or laminated, are used.

As for the shape of the base, it is more preferable to have a cylindrical shape rather than a sheet shape because the size can be made smaller than a drum made by winding a sheet.

However, molding the metal into a cylindrical shape as described above increases the manufacturing cost of the electrophotographic photoreceptor. In a photographic photoreceptor, the charge generation layer is formed as a thin film in contact with the substrate, so that the electrophotographic characteristics are greatly affected by the surface properties of the substrate. For this reason, plastics are cheaper than metals and can be molded into shapes such as cylinders. However, when plastic is molded alone, it is unsatisfactory as a base in terms of mechanical strength, impact resistance, dimensional stability, thermal deformability, etc.

Therefore, although the present invention is a base using plastic,
The main object of the present invention is to provide an electrophotographic photoreceptor using a substrate having excellent properties in terms of mechanical strength, impact resistance, dimensional stability, thermal deformability, and the like. The electrophotographic photoreceptor according to the present invention is characterized in that it has a photosensitive layer on a substrate made of plastic filled with gold Y47 eyeper.

A substrate made of plastic with metal fibers is strong and electrically conductive, so it is very preferable as a substrate for electrophotographic photoreceptors, and this is the book that led to the present invention.

Metal fibers can be made by cutting metals such as aluminum, aluminum alloys, copper alloys such as copper, brass, and bronze, iron, steel, stainless steel, zinc, etc., to a length of 0.5 to 6 m and a diameter of 10 to 60 mm (1 m). It is appropriate to add these as fillers to plastics to improve strength and impact resistance, and when used as a base, the wall can be made thinner, so it is possible to make the base smaller and lighter. Furthermore, since conductivity can be obtained, there is no need to perform special conductive treatment on the base, so costs can be reduced.

In addition, metal fibers are produced using the vibrating vibration cutting method, in which short fibers are cut directly from a metal block using self-excited vibrations in the cutting edge, which produces a uniform fiber shape and is dimensionally stable. It is advantageous for the present invention because it has good properties, sufficient tensile strength, little oxide film, and low cost.

Plastic materials include thermoplastic resins such as polystyrene, polyethylene, polyacetal, polypropylene, polyphenylene oxide, polysulfone, polyarylate, polyphenylene sulfide, phenolic resins,
Thermosetting resins such as area resin, melamine resin, melamine-phenol resin, epoxy resin, diallyl phthalate resin, and unsaturated polyester resin are used. Considering the heat resistance of the substrate, thermosetting resin is more convenient.

The volume electrical resistivity required for the substrate of an electrophotographic photoreceptor is 1.
0"Ω1 or less, preferably 1040α or less. The amount of metal fiber added to the above plastic material is selected so as to satisfy the value of the volume electrical resistivity. However, the resistance is too high, and if the amount is too high, the moldability and surface properties of the plastic will deteriorate.Therefore, it is preferably about 10 to 50% by weight based on the plastic.

An electrophotographic photoreceptor is produced by forming a photosensitive layer on a plastic substrate mixed with metal fibers. The photosensitive layer is
For example, it is formed by coating a photoconductive substance such as dye-sensitized zinc oxide, cadmium sulfide, polyvinyl carbazole, 7-talocyanine pigment, or azo pigment together with a binder if necessary. In addition, when using an organic photoconductive substance,
A photosensitive layer comprising a combination of a charge generation layer that generates stain carriers upon exposure to light and a charge transport layer that has the ability to transport the generated charge carriers can also be effectively used.

The charge generation layer is made of azo pigments such as Sudan Red, Diane Blue, and Jenas Green B, Algol Yellow,
Quinone pigments such as pinone quinone and indanthrene brilliant violet RRP, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, bisbenzimidazole pigments such as India First Orange toner, 7-lycyanine pigments such as copper phthalocyanine, quinacridone pigments, etc. Charge generating materials such as polyester, polystyrene, polyvinyl chloride, polyvinyl acetate,
It is formed by being dispersed in a binder resin such as cellulose esters, polyvinyl butyral, polyvinylpyrrolidone, methylcellulose, hydroxypropylmethylcellulose, and polyacrylates.

The charge generation layer is provided above or below the charge transport layer,
Its thickness is about 0.01-2μ, preferably about 0.05-1μ.

In addition, the charge transport layer has a main chain or side chain containing a polynomial aromatic compound such as anthracene, pyrene, phenanthrene, coronennato, or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole,
This is a charge-transporting substance formed by dissolving a hole-transporting substance such as a compound having a nitrogen-containing cyclic compound such as oxadiazole, pyrazoline, thiadiazole, or triazole, or a hydrazone compound in a film-forming resin. This is because they generally have a low molecular weight and have poor film-forming properties on their own. Examples of such resins include polycarbonates, polymethacrylates, polyarylates, polystyrene, polyesters, polysulfones, styrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers, and the like.

The thickness of the charge transport layer is approximately 5 to 2011 mm thick.

Although it is possible to form the photosensitive layer directly on the substrate, it is also effective to apply a resin layer called an undercoat layer between the two. The undercoat layer is formed to improve adhesion of the charge transport layer, improve coating properties, protect the substrate, cover defects on the substrate, improve charge injection from the substrate, protect the photosensitive layer from electrical breakdown, etc. Ru. Known materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidasol, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, copolymerized nylon, glue, gelatin, etc. There is. These are each dissolved in a suitable solvent and applied onto the substrate. The film thickness is about 0.2 to 2μ.

In addition to the above, the photosensitive layer may be formed by applying cadmium sulfide, zinc oxide, cadmium selenide, etc. to the substrate together with a binder, or 5e18i.

It may also be formed by vapor depositing 8e-Te or the like on the substrate.

Regarding the photoconductor having an insulating layer, various ordinary resins can be appropriately used as the resin used to form the insulating layer. For example, polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, acrylic resin II, polycarbonate,
These include silicone resin, fluororesin, epoxy resin, etc.

Usually the thickness of the insulating layer is 0.1~100μ, especially 0.1~
It is set to 50μ.

By forming the base from plastic filled with metal fibers, the base can be made thinner and smaller.
It is possible to reduce the weight. Furthermore, since it is electrically conductive, it does not require any special conductive treatment.

Example: An A/fiber with a diameter of 1) μ and a length of 0.5 mm manufactured by the Bibishi vibration cutting method was placed in a polyarylate resin.
Add the amount to 20% by weight to prevent crosstalk, and the inner diameter is 7.
A base body was formed into a cylindrical shape with an outer diameter of 80 u+ and a length of 300 m. This base has sufficient strength as a base,
The resistivity was 5001, which was satisfactory.

Next, 10 parts of a disazo pigment having the following structural formula, 6 parts of cellulose acetate butyrate resin (trade name: CAB-381: Eastman Chemical Exhibition), and 60 parts of cyclohexanone were dispersed for 20 hours in a sand mill apparatus using 1φ glass beads. 100 parts of methyl ethyl ketone was added to this dispersion, which was applied onto the undercoat layer by dip coating, followed by heating and drying at 100° C. for 10 minutes to form a charge generating layer with a coating weight of 0.19 parts m''.

Next, 10 parts of a hydrazone compound having the following structural formula and a polystyrene resin (trade name: Dialex HF) were added.
'-55 (manufactured by Mitsubishi Monsando Chemical Co., Ltd.) dissolved in 60 parts of monochlorobenzene was applied onto the charge generation layer and dried with hot air at 100°C for 1 hour to form a charge transport layer with a thickness of 15μ.

Corona charging, image exposure, dry toner development, toner transfer to plain paper, urethane rubber blade (hardness 70°, pressure I
When the goby image was viewed by attaching it to an electrophotographic copying machine having a cleaning process based on Q gw/cWL and an angle of 20) with respect to the photoreceptor, a very good image was obtained.

Example 2 Copper fiber 1 with a diameter to It and a length of 0.5, manufactured by chatter vibration cutting method, as a filler in phenolic resin.
Five layers of i#chi were added and kneaded, and the mixture was molded into a cylindrical shape with an inner diameter of 76 mm, an outer diameter of 80 mm, and a length of 300 mm to obtain a substrate.

Next, the above substrate was dip-coated using a solution obtained by dissolving 10 parts of polyamide resin (trade name: CM8000° manufactured by Toshi) in 80 parts of methanol and then adding 30 parts of butanol to form a 1 μ thick undercoat layer. was born. A charge generation layer and a charge transport layer were formed thereon in the same manner as in Example 1 to form a photoreceptor. As in Example 1, good images could also be obtained with this photoreceptor.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor characterized by having a photosensitive layer on a substrate made of plastic filled with metal fibers.