JPS60254141A - Production of electrophotographic sensitive body by coating - Google Patents

Abstract

PURPOSE:To coat a paint on a base body without whitening and dew condensation by provding a wind shielder Hmm. height above a coating tank, dipping the base body into a paint tank and pulling up the base body at Vmm./s speed then pulling up the base body in the wind shielder at the speed Amm./s satisfying the relation V>A>H/2. CONSTITUTION:The paint 8 is put into the coating tank 1 and a cap 2 is put on the tank 1. The wind shielder 3 is attached onto the cap and the height thereof is made Hmm.. The base body 7 is first dipped in the paint 8 and is then pulled at Vmm./s pulling up speed. The base body 7 is thereafter pulled up at Amm./s speed in the shielder 3. The speed A is set smaller than V and larger than H/2. The uneven painting and the remaining of foam are thus prevented, by which the working time is reduced and the workability is improved. The method is suitable for production of an electrophotographic sensitive body.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic photoreceptor in which a resin layer and/or a photosensitive layer are formed by a dip coating method.

2. Description of the Related Art Electrophotographic photoreceptors generally have a sheet-like shape or a cylindrical shape. The sorted electrophotographic photoreceptor is
A photosensitive layer is applied to a resin film or aluminum foil by a method such as roll coating, bar code coating, knife b-), or blade coating.

In the case of a cylindrical shape, the photosensitive layer is applied to a substrate made of a metal such as stainless steel, aluminum, copper, or brass, or a material such as paper or plastic that is molded into a cylindrical shape. is optimal. This method is
The substrate is immersed in a coating tank containing paint to a predetermined depth with its longitudinal direction vertical, and then the substrate is pulled up at a certain speed (coating speed) to form a paint layer on its surface.

In this case, the state of the coating film immediately after coating is very unstable, with a considerable amount of the coating solvent remaining in the coating film without being evaporated. For this reason, if the coating film was immediately introduced into the air immediately after application, the organic solvent in the coating film would rapidly evaporate, causing whitening and dew condensation on the coating film, which was undesirable.

Problems to be Solved by the Invention It is an object of the present invention to avoid whitening and condensation when manufacturing an electrophotographic photoreceptor using X-ray coating.

Moreover, the aim is to provide a method that can increase productivity.

Means and operation for solving the problems The present invention provides a wind shield (hood) above the coating tank to cover the periphery of the substrate so that the dip-coated coating film is not exposed to direct wind. It is something. A cross-sectional view of this is shown in Figure 1.

1 is a coating tank, 2 is its lid, and 5 is a hood.

Although the shape of the 7-rod can be arbitrary as long as the base is not exposed to wind, a cylindrical shape is particularly suitable. Also, as shown in Figure 2, to allow solvent vapor to escape.

(a) With legs 4 attached to the hood and a gap left (
1.) A net 5-like bottom part, (C') a hole 6 in the bottom part, etc. are also effective. The hood may be made of any material such as plastic, metal, glass, etc.

The coating process is shown in Figure 6. (a) shows the state in which the substrate 7 is immersed in the paint 8. (b) shows the state in which the substrate 7 has been lifted up, the coating has been completed, and the substrate 7 is being pulled up inside the hood. CC) indicates the end of the process.

Here, if the coating speed is V (m/sec), usually (
Up to steps a) to (C), pull up at a speed of (■). Therefore, even when the substrate finishes coating and moves in the hood, it is pulled up at a slow coating speed, so it takes a long time to complete the process.

The present invention is characterized in that, in order to shorten process time and improve productivity, when moving in the hood, it is pulled up at a faster speed than (2). This is based on the inventor's discovery that during coating, the coating is easily affected by wind, but after coating is finished, it is less affected by wind.

However, even though it is said to be less susceptible to the influence of wind, it does not mean that the substrate can be pulled up from the hood indefinitely and quickly. That is, if it is too fast, the solvent dries rapidly, resulting in whitening and waviness of the coating film. The speed limit is
It varies depending on the thickness of the coating film, the proportion of solvent contained in the coating film, the height of the hood, etc. A guideline for maximum speed is approximately determined by the time the substrate remains in the hood, which should be at least 2 seconds.

Therefore, the maximum speed A (f/sec) for pulling up the substrate from the hood is expressed by the formula A=H/20, and if it is less than this, it is not too fast. However, H is the height of the hood Ca
n,).

That is, the present invention is characterized in that after the substrate is coated at a speed V, it is pulled up from the hood at a speed where vx is also fast and A≦H/2. □ The coating speed ■ is normally 0.5 to 8 m/sec in the case of coating an electrophotographic photoreceptor, and it takes time to pull it up, but as in the present invention, it is possible to increase the speed of lifting it from the hood. This will greatly shorten the process.

Now, to explain about the Seiko photographic photoreceptor, first, the substrate is made of metal such as aluminum, brass, or stainless steel, or polyethylene terephthalate, polybutylene terephthalate, phenol resin, polyvinyl resin, nylon,
It is used by molding a polymer material such as polystyrene or a material such as hard paper into a cylindrical shape. In the case of an insulator, it is necessary to conduct a conductive treatment, which includes methods such as impregnation with a conductive substance, lamination with metal foil, and metal vapor deposition. The photosensitive layer is made of dye-sensitized zinc oxide, selenium powder, amorphous silicon powder, and polyvinyl carbazole.

A phthalo-7-anine pigment, an oxadiazole pigment, or the like is coated together with a binder resin if necessary.

In addition, when using an organic photoconductive material, an effective method for achieving the same characteristics as described above is to combine a charge generation layer that generates charge carriers upon exposure to light and a charge transport layer that has the ability to move the generated charge carriers. There is also.

The charge generation layer is made of azo pigments such as Sudan Red, Dia 7 Blue, and Jenas Green B, and Disazo JllJI+.
Kino/pigments such as , Fulgol Yellow, Vire/quinone, quinocyanine pigments, perylene pigments, indigo pigments,
Bisbenzimidazole pigments such as India Fast Orange Toner, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, biryllium salts, azulenium salts, and other charge-generating substances may be used in combination with polyester, polyvinyl acetate, acrylic, polyvinyl butyral, polyvinylpyrrolidone, methylcellulose, hydroxyl, etc. It is formed by dispersing it in a binder resin such as propyl methylcellulose or cellulose ester. Alternatively, it can also be formed by vapor deposition or the like. The thickness of the charge generation layer is approximately 0.02 to 0.2 μm.

In addition, the charge transport layer may contain poly-R aromatic compounds such as anthracene, pyrene, phenanthrene, coronene, etc., or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, etc. in the main chain or side chain.
It is formed by dissolving a hole-transporting substance such as a compound having a nitrogen-containing cyclic chemical formula such as oxadiazole, pyrazoline, thiadiazole, or triazole, or a hydrazone compound in a film-forming resin. This is because the charge transporting substance generally has a low molecular weight and has poor film-forming properties by itself. Such resins include polycarbonate, polyarylate, polystyrene, polymethacrylic acid esters, styrene-methacrylic acid, methyl copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, and the like. The thickness of the charge transport layer is 5 to 20
It is about μ.

It also improves the adhesion between the substrate and the photosensitive layer, improves the coating properties of the photosensitive layer, protects the substrate, covers defects on the substrate, protects the photosensitive layer from electrical elutriation, and improves charge injection from the substrate to the photosensitive layer. For this purpose, it is effective to provide an undercoat layer between the substrate and the photosensitive layer.

The undercoat layer is made of polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinylimidazo-/l/, ethyl cellulose, methyl cellulose, casein, polyamide,
Phenol resin etc. are used.

Furthermore, it is also effective to further form a conductive layer between the substrate and the undercoat layer in order to improve the electrical conductivity of the substrate and cover defects. The conductive layer is used by dispersing a conductive substance in a resin in order to actively impart conductivity. Examples of conductive materials include carbon dioxide, tin oxide, tin oxide, tin oxide, copper iodide, conductive zinc oxide, iron oxide, conductive titanium oxide, metal powder, etc. As resins, epoxy , polyurethane, alkyd, melamine,
Examples include phenol resins, acrylate resins, and the like.

In the case of any of the above layers, application of the manufacturing method according to the present invention can effectively form a resin layer and/or a photosensitive layer.

〔Effect of the invention〕

The manufacturing method according to the present invention can be effectively used for any of the above layers. That is, when forming the resin layer and/or the photosensitive layer, the time required for the coating process can be shortened.

Hereinafter, specific effects will be explained using actual winding examples.

Actual Pond Example 1 A cylindrical container with an inner diameter of 100φ x 400 mm was used as a coating tank. Also, the hood as a wind shield is 1.11
It has a shape as shown in Figure 2 (a), using Bolietele/sheet, 80φ x 300mra, and 10mm at the bottom.
I created six legs with a height of mm. In addition, as a base,
]・60φ×260tnm shaped as shown in Figure 7VC
An aluminum cylinder was used.

Titanium oxide powder (trade name: 2ECT62, manufactured by Titan Kogyo Co., Ltd.) coated with tin oxide containing 10% of antimony oxide in an amount of 75% by weight based on titanium oxide.
titanium oxide powder (trade name: 5R-1) coated with 2% by weight of alumina on titanium oxide/
, manufactured by Sakai Chemical Industry Co., Ltd.) were mixed with resol-type phenolic resin (trade name: Nibriophen 5010).
, manufactured by Inu Nippon I/Ki Kagaku Co., Ltd., solid content 58%) 85 parts,
and 60 parts of 2-methoxyethanol. After thorough mixing, the mixture was dispersed in a sand mill for 2 hours.

After adjusting the viscosity of this obstetric material to 90 cp, it was placed in a coating tank shown in Fig. 4 of 2.6 e.

After slow stirring, the substrate was immersed and withdrawn at a rate of 2.5 steps/second. After the substrate is separated from the base material.

It was pulled out of the hood for 15 seconds at a speed of 20 mm/sec. Note that since H/2=150, the speed is smaller than this. After taking it out of the hood, it was placed in a heater at 140° C., and heated and cured for 60 minutes to form a conductive layer with a thickness of 20 μm.

For comparison, when a conductive layer was formed in the same manner by pulling it out of the hood at a speed of 150+ai/sec, streak-like unevenness occurred on the surface. It is thought that because the speed of lifting from the hood was high, the M agent rapidly evaporated, resulting in uneven composition.

Also, it increases the speed of lifting from the inside of the hood, 25m
If the material was continuously pulled up at a speed of m/sec, it would take as long as 120 seconds, which had the disadvantage of lengthening the process.

In addition, when dipping the substrate, in order to prevent the air trapped inside the substrate from forming bubbles and causing coating defects,
As described in JP-A No. 58-74170, it is preferable to use a method in which part of the air inside the base is removed, and FIG. 4 shows this embodiment. 9 is a ventilation pipe, and 10 is an air chamber. The same applies to other embodiments.

Example 2 2 parts of copolymerized nylon (trade name: Amilan CM8000, manufactured by Toshiku Co., Ltd.) and 8-nylon (trade name: EF30T)
The mixture was fermented in 50 parts of methanol (manufactured by Teikoku Kagaku Co., Ltd.) and 45 parts of toluene, and placed in a coating tank having the same shape as in Example 1. The substrate prepared in Example 1 was immersed,
The substrate was then pulled up at a speed of 3 mm/sec, and after the substrate was separated from the paint, it was pulled out of the hood at a speed of 40 mm/sec.

It was dried at 50° C. for 6 minutes to form a 0.5 μm thick undercoat layer.

For comparison, when it was pulled out of the hood at a speed of 150 m/s, the surface was exposed to rapid evaporation of methanol ↓
A phenomenon of whitening occurred.

Example 6 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 Co., Ltd. M) and 60 parts of cyclohexanone were mixed into 1φ
Dispersion was carried out for 20 hours using a sand mill apparatus using glass beads. 7,100 parts of methyl ethyl keto was added to this dispersion, and 2.61 parts of the mixture was placed in a coating tank having the same shape as in Example 1.

The substrate prepared in Example 2 was immersed and then pulled up at a rate of 3 mu/s, and after the substrate was separated from the paint,
It was pulled out of the hood at a speed of vr/sec.

It was dried at 50° C. for 6 minutes to form a charge generation layer with a thickness of 0.1 μm.

For comparison, when the sample was pulled out of the hood at a speed of 150 mm/sec, unevenness occurred on the surface.

Example 4 10 parts of a hydrazone compound having the following structural formula and styrene-methyl methacrylate copolymer resin (trade name: M8-20)
cl, Nippon Steel Chemical Co., Ltd. & ) 12 parts to 70 parts of toluene
2.3e and placed in a coating tank having the same shape as in Example 1. However, the height of the hood was 50 mttt. H/
2=25.

The substrate prepared in Example 3 was immersed and then pulled up at a rate of 2 wL/sec after the substrate was separated from the paint.

20i+1! It was pulled out of the hood at a speed of 1/sec.

It was dried at 100° C. for 1 hour to form a charge transport layer with a thickness of 16 μm, thereby preparing an electrophotographic photoreceptor.

For comparison, when the film was pulled out of the hood at a speed of 30/sec, uneven film thickness occurred.

When the electrophotographic photoreceptor produced as described above was placed in a predetermined electronic copying machine and the image quality was examined, it was found that the image was good and had no defects. In the comparative examples of the respective examples, those that had unevenness also had corresponding defects and unevenness in the images □□□.

[Brief explanation of drawings]

, El-1 shows an outline of a coating tank equipped with a hood, Figure 2 shows the shape of the hood, Figures 1-6 show the coating process, and Figure 4 shows a coating tank with a ventilation pipe. 1 is a coating tank, 2 is a lid, 6 is a hood, 4 is a foot, 5 is a net,
6 is a hole, 7 is a base, 8 is a paint, 9 is a ventilation pipe, and 10 is an air chamber. Patent applicant Canon Co., Ltd. Agent Patent attorney Yu Kano Figure 1 Figure 2 (a) (b) (c) Figure 4

Claims (1)

[Claims] (1) It has a dip coating tank and a wind shield with a height H (mm ) installed above it, and after dipping the substrate in the paint, the coating speed is v
(mi/sec) after pulling up the substrate, 7 or more and A
A method for producing an electrophotographic photoreceptor, which comprises forming a resin layer and/or a photosensitive layer by pulling up a substrate from a wind shield at a speed A (+i/sec) of <HI3.