JPS6066258A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance adhesion property between a substrate and a photosensitive layer without adversely affecting image quality by forming a layer contg. an N- dimethylaminated nylon resin between said layers as an underlayer. CONSTITUTION:A layer to be formed as an underlayer contains an N-dimethylaminated nylon resin obtained by copolymerizing epsilon-caprolactam with alpha-(N- dimethylamino)-epsilon-caprolactam on a substrate such as aluminum, polyethylene terephthalate. An intended electrophotographic sensitive body is obtained by forming a photosensitive layer on this underlayer. Said N-dimethylaminated nylon resin has repeating units represented by the formula (m, n are each an integer), it lowers electric resistance, it is small in rise of resistance even in low humidity, easily soluble in alcohol and water, and it facilitates coating operation, and therefore, it can be favorably used for the undercoat.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor having a layer containing an N-dimethylaminated nylon resin.

The electrophotographic photoreceptor is basically composed of a KIi substrate and a photosensitive layer. However, improvements in adhesion between the substrate and photosensitive layer, improvement in coating properties of the photosensitive layer, protection of the substrate, covering defects on the substrate, protection against electrical breakdown of the photosensitive layer, improvement of charge injection from the substrate to the photosensitive layer, etc. Therefore, it is effective to provide an undercoat layer between the substrate and the photosensitive layer.

The undercoat layer is conventionally made of polyvinyl alcohol.

Known examples include phyllinyl methyl ether, poly-N-vinylimidazole, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, gelatin, and polyamide.

The first characteristic required of the undercoat layer is electrical characteristics. Since it is used for electrophotographic photoreceptors, it is important that the electrophotographic properties are not affected, and for this purpose, it is necessary that the electrical resistance is low. When the electrical resistance is high, a charged potential is applied to the undercoat layer, and a so-called residual potential causes fogging in the image.

Furthermore, it is necessary that the electrical resistance is unaffected by changes in the external environment, in particular by changes in atmospheric humidity. For example, when electrical resistance increases due to low humidity, fogging can occur.

Furthermore, since the undercoat layer is applied as a paint, the coatability and solubility of the material also pose problems. That is, it is preferable that the coating can be applied more easily and neatly. Further, it is preferable to dissolve it in a common inexpensive solvent without using a special solvent.

However, with conventional materials, it has been difficult to obtain materials that satisfy all of these requirements. Therefore, it is an object of the present invention to provide a new material that satisfies these requirements.

As a result of examining various resin materials, N-dimethylaminated nylon resin was found to be suitable for the purpose of the present invention, and the present invention is characterized in that it is used.

N-dimethylaminated nylon resin is a resin obtained by copolymerizing C-caprolactam and α-(N-dimethylamino)-caprolactam, and has repeating units represented by the following general formula.

f耶0H20I (20H2%-■oo廿珊(aa2)5
Ca%m%n is an integer, and the properties change by changing these values. That is, when m-0, it is so-called 6-nylon, and as m increases, N-u
The ratio of methylamino groups increases, and the crystallinity of the resin decreases, making it non-crystalline. Therefore, it becomes easily soluble in alcohol, water, etc. Furthermore, it is difficult to gel even if left standing after dissolution. Furthermore, compatibility with other resins is also improved. That is, except for m=0, the m:n ratio is preferably up to a range of 10:1, and the average molecular weight is 5000 to 1000.
00 is preferred.

Other resins include hydroxyethyl cellulose,
40 xyprobyl methylce! Examples include reulose, ;f:+)hinyl alcohol, polyvinylpyrrolidone, polyacrylamide, and sodium polyacrylate.

As described above, since it is easily dissolved in alcohol (methanol, ethanol, isopropyl alcohol) and water, coating becomes very easy. In particular, being able to use water is advantageous in terms of cost, pollution, etc.

Further, the N-dimethylamino group has the property of lowering electrical resistance, and furthermore, it is advantageous because the increase in resistance is small even at low humidity. Therefore, it is very convenient as an undercoat layer.

In addition, it has strong adhesion to metals such as aluminum, so no problems arise in this respect.

To explain the electrophotographic photoreceptor of the present invention in more detail, first, the substrate is made of metal such as aluminum, brass, or stainless steel, or polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene,
It is used by molding polymeric materials such as nylon and polystyrene, or materials such as hard paper into a cylindrical shape, or by making it into a film or foil. 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. Furthermore, if the surface roughness of the substrate is large, a conductive paint may be applied to smooth the surface. Conductive paints include metal powders such as aluminum, copper, silver, gold, and nickel, metal oxide powders such as tin oxide, indium oxide, antimony oxide, titanium oxide, and zinc oxide, and carbon powders. One or more of these compounds can be used dispersed in a binder resin such as polyurethane, epoxy, alkyd, polyester, acrylic melamine, silicone, or phenol resin. The thickness of the conductive iE layer coated with the conductive paint is preferably at least twice the surface roughness of the substrate.

2. A layer of the N-dimethylaminated nylon resin of the present invention is coated on the substrate or a conductive layer formed on the surface of the substrate. . The thickness is preferably about 0.2 to 5 μm.

A photosensitive layer is formed on this.

The photosensitive layer is formed by coating dye-sensitized zinc oxide, selenium powder, amorphous silicon powder, polyvinyl carbazole, phthalocyanine pigment, oxadiazole pigment, etc. together with binder resin if necessary.

In addition, when using organic photoconductive materials, an effective method for improving properties is to combine a charge generation layer that generates charge carriers by mist light and a charge transport layer that has the ability to move the generated charge carriers. Sometimes.

The charge generation layer is made of azo pigments such as Sudan Red, Guianpuru, Jenas Green B, Algol Yellow,
Quinone pigments such as pyrenequinone and indanthrene brilliant violet FRP; quinocyanine pigments; It is formed by dispersing a charge generating substance such as a pyrylium dye in a binder resin such as polyester, polystyrene, polyvinyl acetate, acrylic, polyvinyl butyral, polyvinylpyrrolidone, methylcellulose, hydroxyzolobyl methylcellulose, or cellulose esters. Alternatively, it can also be formed by vapor deposition or the like. The thickness of the charge generation layer is approximately 0.05 to 0.2 μm.

In addition, the charge transport layer has a main chain or a side chain containing a polycyclic aromatic compound such as anth-2cene, pyrene, 7-enanthrene, coronennato, or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole,
It is 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 resin that has film-forming properties. 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, polymethacrylates, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, and the like.

The thickness of the charge transport layer is approximately 5 to 20 microns.

The specific compounding ratio, structure of the photosensitive layer, etc. will be described in detail in Examples.

Example 1 ε-caprolactam and α-(N-E; methylamino)-
An N-dimethylaminated nylon resin having a molecular weight of about 27,000 and copolymerized with c-caprolactam in a monomer composition of 1:1 was prepared.

10 parts (by weight) of this resin were added into 90 parts of water heated to 80° C. with stirring, and dissolved. After cooling to room temperature, it was coated on an aluminum sheet using a wire parr and heated to 90° C. to form an undercoat layer with a thickness of 1 μm.

Next, 50 parts of zinc oxide powder for electrophotography (manufactured by Hakusui Kagaku ■) was added to a solution consisting of 0.2 parts of rose bangal, 5 parts of methanol, and 50 parts of n-hebutane, and the mixture was heated in a homogenizer for 20 parts. Dispersed for minutes. This was taken out by suction filtration and thoroughly dried at 80°C to obtain dye-sensitized zinc oxide.

Acrylic resin (trade name: Niacrybase OMZ-20, manufactured by Fujikura Kasei ■, solid content: 40%) is added to 60 parts of this zinc oxide.
2 parts and 45 parts of toluene were added and dispersed in a ball mill for 4 hours. Applying the dispersion liquid onto the undercoat layer 2
A 2μ thick photosensitive layer was formed and thoroughly dried at 80°C.

The thus obtained photoreceptor was used as a master sheet in an electrophotographic copying machine. When I took a copy of the image, it was very good. In contrast, the following comparative example was compared.

First, casein, which is widely used as an undercoat layer for zinc oxide master sheets, was used. Casein was dissolved in 5% aqueous ammonia and applied in the same manner to form an undercoat layer.

When a photosensitive sheet was prepared and a copy image was taken, the image was good.

However, casein solution has a perishable property and has a shelf life of l-! It was 2-6 days. Note that the solution of N-dimethylaminated nylon resin did not spoil.

In addition, 6-nylon can be used with concentrated sulfuric acid, formic acid, butane v.
/L/ It was difficult to apply because it only dissolves in special solvents such as a phenol-methanol mixture.

Next, when using soluble nylon (trade name 6o21, manufactured by Ube Industries, Ltd.), which is mainly composed of 6-nylon and partially copolymerized, it is soluble in methanol, but it is difficult to gel due to gelation. The mission period was two days. Furthermore, even when applied during the pot life, it could not be used as an undercoat layer due to insufficient adhesion to aluminum.

Furthermore, all of the conventional water-soluble subbing layer materials mentioned above have a
Most of them caused fog in the image.

Example 2 N-)methylaminated nylon resin used in Example 1 8
1 part and 2 parts of polyvinyl alcohol (trade name: Popal 420, manufactured by Nippon Gosei Kagaku ■) were dissolved in 80 parts of water.

This solution was coated on an aluminum sheet using a wire no. As a result, repellency occurred in some areas, but when used in combination with polyvinyl alcohol, the coated surface was clean.

Even if the same photosensitive layer as in Example 1 is formed on this, good quality -j
A bee image was obtained.

Example 3 Example with a conductive layer Titanium oxide powder (Titan Kogyo@#) 10 parts, tin oxide powder (Mitsubishi Metals ■) 7 parts, acrylic resin (trade name Nearcridic A405, Dainippon Ink ■) (manufactured by Dainippon Ink), 4 parts of melamine resin (trade name: Nis-Perbeckamine L121, manufactured by Dainippon Ink), and 20 parts of toluene were dispersed in a ball mill over 6 hours. This dispersion was applied to a 60φ x 260wn aluminum cylinder with a surface roughness of 4μ. This was cured at 150° C. for 0 minutes to form a conductive layer with a thickness of 20 μm. In this case, the surface roughness was 0.5μ.

Next, 10 parts of N-dimethylaminated nylon resin having a molecular weight of approximately 20,000 and copolymerized with a composition of ε-caprolactam and α-(N-dimethylamino)-ε-caprolactam in a ratio of 2=1 was prepared. and dissolved in 90 parts of ethanol. This solution was applied onto the conductive layer to form an undercoat layer with a thickness of 1 μm.

Next, 10 parts of a disazo pigment having the following structural formula, 6 parts of cellulose acetate butyrate resin (trade name: CAB-581, manufactured by Eastman Chemical Company), 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, and the mixture was dip coated onto the undercoat layer, followed by heating and drying at 100° C. for 10 minutes to form a charge generating layer with a coating amount of 0.197 m 3 .

Next, 10 parts of a hydrazone compound having the following structural formula and 15 parts of a styrene-methyl methacrylate copolymer resin (trade name: MS200, manufactured by Nippon Steel Chemical) were mixed with 8 parts of toluene.
Dissolved in 0 parts. This liquid 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 16 μm.

The electrophotographic photoreceptor thus produced was heated to -5,6K
V corona charging, image exposure, dry toner development, toner transfer to plain paper, urethane rubber blade (hardness 70°, pressure 10 gw/cm, angle to photoreceptor 200)
The electrophotographic characteristics were evaluated by attaching it to an electrophotographic copying machine that has a cleaning process and the like. The potential was set to -620V, and a good image could be obtained.

For comparison, we omitted the use of the conductive layer in which powder was dispersed as described above, and applied the aforementioned N-') methylaminated nylon resin layer directly on the aforementioned aluminum cylinder, and then applied a charge on it. A generation layer and a charge transport layer were formed and manufactured. In the case of this electrophotographic photoreceptor, when looking at the image, a scratch pattern corresponding to the roughness of the substrate appeared, and it was a defective image. Patent applicant: Canon Co., Ltd. Agent, Patent attorney Yu Kano

Claims (1)

[Claims] An electrophotographic photoreceptor comprising a layer containing an N-dimethylaminated nylon resin obtained by copolymerizing (1) with -caprolactam and α-(N-dimethylamino)-6-caprolactam.