JPH0560865B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a copper phthalocyanine photoreceptor and a method for manufacturing the same.

[Conventional technology]

Generally, in electrophotography, the surface of the photosensitive layer of a photoreceptor is charged and exposed to form an electrostatic latent image, which is developed with a developer to make it visible, and the visible image is directly transferred onto the photoreceptor. A method is used in which the visible image on the photoreceptor is transferred onto a transfer paper such as paper and the transferred image is fixed to obtain a copied image. These methods are mainly applied to electronic printers, laser printers, and facsimile machines.

Conventionally, amorphous selenium, cadmium sulfide, or zinc oxide has been widely used as a photoconductive material to form a photosensitive layer of an electrophotographic photoreceptor used for this type of purpose. However, amorphous selenium is difficult to manufacture because it requires vapor deposition on a conductive support, and the vapor-deposited film is not flexible and is highly toxic, so it requires careful handling and is expensive. There are drawbacks to it. On the other hand, the sensitivity of cadmium sulfide and zinc oxide is significantly affected by the mixing ratio with the binder that binds them onto the substrate. As a result, mechanical strength such as flexibility, smoothness, hardness, and wear resistance is low, and furthermore, the characteristics deteriorate due to ozone generated due to corona charging. In addition, there were hygienic problems such as the possibility of environmental pollution due to its toxicity. In order to solve these drawbacks and problems, in recent years, organic photoreceptors that have excellent processability and are free from hygienic problems such as toxicity and environmental pollution have been increasingly developed and become popular.

In terms of structure, organic photoreceptors are generally classified into single-layer types and multi-layer types. The single-layer type is formed by coating a conductive substrate with a photosensitive layer consisting of a charge-generating material, a charge-transmitting material, and a binder. The multilayer type is
After coating a conductive substrate with a charge-generating substance by vapor deposition or coating, a charge-generating layer is formed on the charge-generating layer.
Further, a suspension consisting of a charge transfer material and a binder is coated and dried. Once such a photoreceptor is exposed to light, charge pairs are generated from the charge-generating material, and due to the action of the electric field, electrons are released via the conductive substrate, while electron holes pass through the charge-transfer material and are exposed to light. It can be transmitted to the body surface to neutralize its negative charge and form an electrostatic latent image.

The charge generating materials used in organophotoreceptors are usually
It is an organic pigment with photoconductivity. Examples include bisazo pigments, anthrahydroquinone pigments, thioindigo pigments, and phthalocyanine pigments. Among them, copper phthalocyanine, which belongs to the phthalocyanine pigments, has excellent coloring power, light resistance, heat resistance, and chemical resistance, has no toxicity problems, and is low in cost, so it is widely used as a blue organic pigment. is the current situation.

Already known copper phthalocyanines have crystal forms of α-, β-, γ-, δ-, and π.
There are eight types: -, ρ-, χ-, and ε-. Among them, three types, α-, β-, and ε-, are mass-produced and widely used. In particular, ε-type copper phthalocyanine exhibits high absorption for long wavelength light (around 780 nm) such as that produced by semiconductor lasers, and is thought to be applicable to laser printers and facsimile machines that develop using electrophotography, so it is widely used in various fields. It is attracting a lot of attention. However, the conventional ε-type copper phthalocyanine lacks sensitivity as a charge-generating substance, and the required light energy from exposure until the surface potential attenuates by half is too high, and when applied to photoreceptors, The potential difference of the latent image becomes insufficient, making it difficult to form a clear copy image.

There is a method to increase the sensitivity by coating the surface of ε-type copper phthalocyanine with a dye sensitizer (Japanese Patent Application Laid-Open No. 1987-
161249). However, this method has the drawback of varying the absorption wavelength so that sensitivity is lost near the infrared wavelength range (around 780 nm).

[Problem to be solved by the invention]

The present invention improves the manufacturing method so that a photoreceptor made of copper phthalocyanine as a charge generating substance has high sensitivity in the infrared wavelength range, and is applicable to laser printers, facsimile machines, and electronic printers that are developed by electrophotography. The purpose is to become a body.

[Means to solve the problem]

To achieve the above object, the present invention uses copper phthalocyanine treated with iodine gas as a charge generating material and coats it on a conductive substrate together with or separately from a charge transporting material to form a photosensitive layer. A copper phthalocyanine photoreceptor is manufactured by the method.

That is, the manufacturing method of the present invention includes, for example, a binding layer forming step in which a conductive substrate is coated with a binder and then dried, and a binding layer forming step in which copper phthalocyanine is dispersed in the binder. a charge generation layer forming step in which the charge generation layer is coated on the binding layer formed in the step and then dried; an iodine treatment step in which the charge generation layer formed in the charge generation layer formation step is treated with iodine gas;
One example is a method comprising a charge transport layer forming step in which an electron hole transport material is dispersed in a binder and coated on the charge generation layer treated in the iodine treatment step.

By treating copper phthalocyanine with iodine gas, iodine is adsorbed or attached to its surface.

By such a method, the present invention provides an organic photoreceptor in which a conductive substrate is coated with a charge-generating substance and a charge-transferring substance as a photosensitive layer, and in particular, an organic photoreceptor in which a copper phthalocyanine treated with iodine gas is used as the charge-generating substance. A photoreceptor can be provided.

Copper phthalocyanine is suitable as the above-mentioned charge generating substance, but it is desirable to use three types of α-, β-, and ε-type, and it is particularly preferable to use the ε-type.

As the charge transfer substance, so-called electron hole transfer substances are desirable, and examples thereof include hydrazone compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds. Examples of hydrazone compounds include p-diethylaminobenzaldehyde-N,N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, and p-(1-pyrrolidinyl)-benzaldehyde-N,N- diphenylhydrazone, 1,3,3
-Trimethylindolinine-ω-aldehyde-
Examples include N,N-diphenylhydrazone and p-diethylaminobenzaldehyde-3-methylbenzthiazolinone-2-hydrazone. Examples of pyrazoline compounds include 1-phenyl-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[quinolyl(2)]-3
-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3-(p-diethylaminostyryl)-
Examples include 5-(p-diethylaminophenyl)pyrazoline. Further, as oxazole compounds, 2-(p-diethylaminostyryl)-6-diethylaminobenzoxazole, 2-(p-diethylaminophenyl)-4-(p-dimethylaminophenyl)-5-(2-chlorophenyl) ) Oxazole and thiazole compounds include 2-(p
-diethylaminostyryl)-6-diethylaminobenzothiazole and triallylmethane compounds include bis(4-diethylamino-2-methylphenyl)-phenylmethane.

The binder is not particularly limited, and commonly used resins can be used. Examples include poly(vinyl butyral), poly(vinyl acetate), polyester, polycarbonate, phenoxy resin, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, urethane resin, epoxy resin,
Examples include casein and poly(vinyl alcohol).

Iodine treatment methods include a method using saturated iodine gas in a closed container and a method using a vacuum evaporation apparatus. The treatment conditions may be such that the ratio of the amount of iodine to the amount of the charge generating material in the treated charge generating material is 0.01 to 1.0. For example, at a temperature of 20℃ to 90℃
It is enough to process for 120 minutes. When the above ratio is less than 0.01, there is no improvement in sensitivity, but when it is more than 1.0, the dark decay characteristic becomes too large and static charges cannot be absorbed sufficiently.

[Effect]

As described above, according to the present invention, copper phthalocyanine treated with iodine gas is used as a charge generating material and coated on a conductive substrate together with or separately from a charge transporting material to form a photosensitive layer. Sensitivity can be increased without affecting the wavelength absorption range of the photoreceptor.

〔Example〕

The present invention will be further explained below with reference to Examples.

Example 1 An aluminum plate of 0.2 mm x 260 mm x 80 mm was used as a substrate, and this was immersed in a methanol solution (solid content: 7%) of polyamide resin, and then dried in an oven at 60°C for about 30 minutes. The thickness of the dried resin binding layer was 1.0 g/m ² .

Meanwhile, completely dissolve 0.22 g of polyvinyl butyral in 10 g of cyclohexanone solvent, and
After adding 0.22 g of copper phthalocyanine (manufactured by BASF, trade name Halogen Blue L6700), the mixture was ground for 1 hour using a pulverizer (manufactured by Matsukron Research Associates, Ltd.) to form a suspension.

The substrate was immersed in the suspension and dried in an oven at 60°C for about 30 minutes. The thickness of the dried charge generation layer was 0.3 g/m ² .

Next, the substrate was treated with iodine for 15 minutes at 35° C. in a closed container into which a predetermined amount of iodine gas was constantly introduced. The iodine uptake of the treated substrate was approximately 7.5 x 10 ^-3 g/m ² .

The substrate was then cooled to room temperature. After dipping the cooled substrate into the charge transport layer composition described below,
Dry in the oven for about 60 minutes. The thickness of the dried charge transport layer was 16 μm. The components of the charge transport layer composition used are shown below.

p-diethylaminobenzaldehyde-N-α
-Naphthyl-N-phenylhydrazone 40g Styrene-MMA copolymer (manufactured by Nippon Steel Chemical Co., Ltd., Japan, trade name MS200) 60g Toluene 330g The above results were measured using a photoconductivity tester EPA-8100 (manufactured by Kawaguchi Denki, Japan). The sensitivity of the obtained photoreceptor was measured. The measured light energy demand is 5.4lux・sec when the light source is a halogen lamp.
When a light source filtered by a 780 nm filter glass was used, the light intensity was 0.1 lux·sec.

Example 2 As in Example 1, a 0.2 mm x 260 mm x 80 mm aluminum plate was used as a substrate, immersed in a methanol solution of polyamide resin (solid content 7%), and dried in an oven at 60°C for about 30 minutes. The thickness of the dried resin binding layer was 1.0 g/m ² .

Meanwhile, completely dissolve 0.22 g of polyvinyl butyral in 10 g of cyclohexanone solvent, and
After adding 0.22 g of copper phthalocyanine (manufactured by BASF, trade name Halogen Blue L6700), the mixture was ground for 1 hour using a pulverizer (manufactured by Matsukron Research Associates, Ltd.) to form a suspension.

The substrate was immersed in the suspension and dried in an oven at 60°C for about 30 minutes. The thickness of the dried charge generation layer was 0.3 g/m ² .

The substrate was then iodine-treated for 60 minutes at 27.5°C in a closed container filled with saturated iodine vapor. The iodine uptake of the treated substrate is approximately 1×
It was 10 ^-2 g/m ² .

The substrate was then cooled to room temperature. After dipping the cooled substrate into a charge transport layer composition similar to Example 1.
It was dried in an oven at 90°C for about 60 minutes. The thickness of the dried charge transport layer was 16 μm.

The sensitivity of the photoreceptor obtained above was measured using a photoconductivity tester EPA-8100 (manufactured by Kawaguchi Denki, Japan). The measured light energy demand is 4.5lux・sec when the light source is a full spectrum light source,
When using a 780nm light source, it was 0.1lux・sec.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Examples 1 and 2. However, no iodine treatment was performed here.

For the photoreceptor created, EPA-8100
The photosensitivity was measured. The measured light energy demand is when the light source is a full spectrum light source.
12.0lux・sec, when using a 780nm light source
0.3 lux·sec, both of which were much higher than those of Examples 1 and 2.

Example 3 An aluminum cylinder with a diameter of 30 mm and a length of 260 mm was used as a substrate, which was immersed in a methanol solution of polyamide resin (solid content 7%) and dried in an oven at 60° C. for about 30 minutes. The thickness of the dried resin binding layer was 1.0 g/m ² .

Meanwhile, completely dissolve 6 g of polyvinyl butyral in 200 g of cyclohexanone solvent, and
g of copper phthalocyanine (manufactured by BASF, trade name Halogen Blue L6700) and 200 g of butanone were added and then dispersed for 72 hours using a ball mill to form a suspension.

The substrate was immersed in the suspension and dried in an oven at 60°C for about 30 minutes. The thickness of the dried charge generation layer was 0.3 g/m ² .

The substrate was then iodine-treated for 30 minutes at 25° C. in a closed container filled with saturated iodine vapor.

The substrate was then cooled to room temperature. After dipping the cooled substrate into a charge transport layer composition similar to Example 1.
It was dried in an oven at 90°C for about 60 minutes. The thickness of the dried charge transport layer was 20 μm.

The photoreceptor prepared above was actually used in a laser printer (Canon LBP-8) and a clear copy image was obtained.

Comparative Example 2 A photoreceptor was prepared in the same manner as in Example 3. However, no iodine treatment was performed here.

The produced photoreceptor was actually used in a laser printer (Canon LBP-8), and a vague copy image was obtained.

〔Effect of the invention〕

According to the above Examples and Comparative Examples, the present invention has a method of forming a photosensitive layer by coating a conductive substrate with a charge-generating substance and a charge-transmitting substance made of copper phthalocyanine treated with iodine gas. The sensitivity of the photoreceptor can be greatly improved without any adverse effects.

Claims (1)

[Scope of Claims] 1. An organic photoreceptor in which a conductive substrate is coated with a charge-generating substance and a charge-transmitting substance made of copper phthalocyanine to which iodine is adsorbed or attached as a photosensitive layer. 2 After coating a conductive substrate with copper phthalocyanine, adsorbing or adhering iodine to this copper phthalocyanine layer so that the value of the amount of iodine to the amount of copper phthalocyanine is from 0.01 to 0.1, and then coating the copper phthalocyanine layer on top of the copper phthalocyanine layer. Copper phthalocyanine photoreceptor coated with electron hole transport material. 3. A binding layer forming step in which an aluminum material is coated with a polyamide resin solution as a substrate and then dried, and the binding layer is formed using a suspension obtained by dispersing ε-copper phthalocyanine in a polyvinyl butyral resin solution. A charge generation layer forming step in which the binding layer formed by the process is coated and then dried, and the charges formed in the charge generation layer forming step are placed in an iodine gas atmosphere at a temperature range of 20°C to 90°C. An iodine treatment step in which the generation layer is maintained for 1 to 120 minutes, and an electron selected from hydrazone compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triallylmethane compounds, and mixtures of two or more thereof. A method for producing a copper phthalocyanine photoreceptor, which comprises a step of forming a charge transport layer, in which a hole transport material is dispersed in a binder and coated on the charge generation layer treated in the iodine treatment step.