JP2551468B2 - Photoconductor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photoconductor used in an electrophotographic apparatus or the like, and more particularly to a laminated type in which a charge generation layer and a charge transport layer are provided on a conductive support. And a phthalocyanine compound as a charge generating material in the charge generating layer.

[Prior Art and Problems Thereof] In a photoconductor conventionally used for electrophotography or the like, an inorganic photoconductive material such as selenium, cadmium sulfide, or zinc oxide is generally used as a photoconductive material contained in the photosensitive layer. Are known.

Here, these inorganic photoconductive materials have many advantages, for example, the fact that the dissipation of charges in the dark is small, and the charges can be rapidly dissipated by light irradiation. have.

For example, selenium-based photoconductors are difficult to manufacture, have high manufacturing costs, and are vulnerable to heat and mechanical shock, and thus require careful handling. In addition, zinc oxide-based photoconductors and cadmium sulfide-based photoconductors do not provide stable sensitivity in humid environments, and the dye added as a sensitizer causes charge deterioration due to corona charging and photobleaching due to exposure. Therefore, there is a drawback that stable characteristics cannot be obtained for a long period of time.

On the other hand, the use of various organic photoconductive polymers such as polyvinylcarbazole as a photoconductive material in the photosensitive layer has also been studied.

Here, these organic photoconductive polymers are superior in terms of film formability, lightness, etc., as compared with the above-mentioned inorganic photoconductive materials, but sufficient sensitivity is not yet obtained, and durability and The stability against environmental changes was also inferior to the inorganic photoconductive material.

Therefore, as a result of various researches and developments in order to improve the above-mentioned points, the phthalocyanine compound has absorption from the visible light region to the near infrared region and has excellent photoconductivity. It has been clarified, for example, JP-A-50-38543, JP-A-51-95852, and JP-A-5353.
In JP-A-64040, JP-A-53-83744 and the like, a photoreceptor using a phthalocyanine photoconductive material has been proposed.

Furthermore, in recent years, the use of the above-described properties of phthalocyanine compounds as a photoconductor in an electrophotographic printer using a semiconductor laser or a light emitting diode as a light source has been studied.

Here, as a photoreceptor using such a phthalocyanine compound, a phthalocyanine compound is dispersed in a binder resin, or a phthalocyanine compound and a charge transport material are dispersed in a binder resin, and the conductive support is used. 5 on top
In addition to a single-layer type photoconductor formed to a thickness of up to 20 μm, a phthalocyanine vapor deposition film as a charge generation layer on a conductive support,
Alternatively, a function-separated type laminate in which a phthalocyanine compound is dispersed in a binder resin to form a dispersion film having a thickness of 0.01 to 1 μm, and a charge transport layer having a thickness of 10 to 30 μm is provided on the charge generation layer Photoconductors are known.

In the case of the photosensitive body using the phthalocyan compound as described above, in the case of the function-separated layered photosensitive body as described above, charge generation and charge transport are separately shared by the substances, so that the material selection is performed. Such a function-separated type laminated photoconductor is generally widely used because the range is widened and the properties required for the photoconductor such as sensitivity, chargeability and surface strength can be remarkably improved.

Further, in the photoconductor using such a phthalocyanine compound, the crystal form of the phthalocyanine compound is
The unstable type is generally used because the unstable type generally obtains higher sensitivity characteristics than the stable type.

However, when such an unstable phthalocyanine compound is used, the electric resistance is lower than that of the stable phthalocyanine compound, so that the charging property is poor, and there is a problem that the receptive potential is lowered when repeatedly used. there were.

[Problems to be Solved by the Invention] The present invention is a laminated-type photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, and a phthalocyanine compound is used as a charge generation material in the charge generation layer. It is an object of the present invention to solve the above-mentioned problems in the photoconductor used, and particularly when an unstable phthalocyanine compound is used as the charge generation material, when the photoconductor is repeatedly used, The object of the present invention is to provide a photosensitive member which is free from problems such as a decrease in receptive potential and has excellent repeated stability.

[Means for Solving the Problems] In the photoconductor according to the present invention, at least a phthalocyanine compound, which is a charge generating material, and an indole compound having a primary amino group, and /
Alternatively, a charge generation layer containing an indazole compound having a primary amino group and a charge transport layer are formed.

As described above, when the charge generating layer using the phthalocyanine compound as the charge generating material contains the indole compound having a primary amino group and / or the indazole compound having a primary amino group, According to the knowledge, an indole compound having a primary amino group or an indazole compound having a primary amino group is selectively adsorbed on a phthalocyanine compound to deactivate the active site of the phthalocyanine compound and trap the carrier. And the like, thereby stabilizing the receptive potential during repeated use.

Here, in the photoreceptor according to the present invention, as the phthalocyanine compound used as the charge generating material, any of phthalocyanine and its derivatives known per se can be used, and specifically, copper, silver, beryllium, magnesium, Calcium, gallium, zinc, cadmium, barium, mercury, aluminum, indium, lanthanum,
Neodymium, samarium, europium, gadolinium,
Mainly dysprosium, holmium, sodium, lithium, ytterbium, lutetium, titanium, tin, hafnium, lead, thorium, vanadium, antimony, chromium, molybdenum, uranium, manganese, iron, cobalt, nickel, rhodium, palladium, osmium and platinum There is a phthalocyanine compound as the core.

Further, the central nucleus of the phthalocyanine may be made of a metal halide having a valence of 3 or more instead of the above metal atom.

Further, copper-4-aminophthalocyanine, iron polyhalophthalocyanine, cobalt hexaphenylphthalocyanine, vanadyl phthalocyanine, and metal or non-metal phthalocyanine derivatives such as tetraazo phthalocyanine, tetramethylphthalocyanine and dialkylaminophthalocyanine can be used.

And these phthalocyanine compounds can be used individually or in mixture.

On the other hand, examples of the indole compound having a primary amino group to be contained in the charge generation layer using the above-mentioned phthalocyanine compound as the charge generation material include, for example, indole, isoindole, 2-indolinone, 3H-indolenine, 2H. -Indolenine, indoxyl, isatin,
An indole compound such as carbazole may have any other substituent as long as it has a primary amino group as a substituent.

Examples of the indazole-based compound having a primary amino group contained in the charge generation layer as described above include, for example, indazole-based compounds such as 3-indazolinone, which have a primary amino group as a substituent. However, it may have other substituents.

And, regarding the amount of the indole compound having these primary amino groups or the indazole compound having a primary amino group in the photosensitive layer, the effect is weak when the content thereof is small, while the content thereof is If the amount is too large, when the charge generation layer is formed on the conductive support by coating or the like, the dispersion stability of the coating solution for the charge generation layer is deteriorated and the adhesiveness thereof is also deteriorated. When used, its residual potential rises,
Preferably, with respect to 1 part by weight of the phthalocyanine compound,
0.01 to 10 parts by weight of these compounds, more preferably 0.
Add 1 to 1 part by weight.

In addition, the photoreceptor according to the present invention contains an indole compound having a primary amino group or an indazole compound having a primary amino group together with a phthalocyanine compound as a charge generating material on the conductive support as described above. The charge generation layer and the charge transport layer may be laminated so that the functions of charge generation and charge transport are separated, and such a laminate type may be a conductive support. In addition to the one in which the charge generation layer and the charge transport layer are laminated in this order, conversely, the charge transport layer and the charge generation layer may be laminated in this order on the conductive support.

Here, the conductive support used in the photoreceptor according to the present invention includes copper, aluminum, gold, platinum,
Foil or plate made of palladium, silver, iron, nickel, etc. formed into a sheet or drum, or those metals vacuum-deposited or electroless plated on a plastic film, conductive polymer, indium oxide, tin oxide A layer of a conductive compound such as that provided on a support such as paper or a plastic film by coating or vapor deposition is also used.

When forming a charge generation layer on such a conductive support, generally, a charge generation material as described above is added to a binder resin solution prepared by dissolving a binder resin in an appropriate solvent. The phthalocyanine compound to be described below is dispersed, the coating solution for the charge generating layer is coated on the conductive support, and the coating is dried to form the charge generating layer.

In this case, when the indole compound having a primary amino group or the indazole compound having a primary amino group as described above is contained in the charge generation layer, these compounds are added to the coating solution for the charge generation layer. In addition to the above, before the phthalocyanine compound is dispersed in the binder resin solution, the phthalocyanine compound is subjected to adsorption treatment, added at the time of dispersion, or the coating solution for the charge generation layer is coated on the conductive support. It can be contained by performing an adsorption treatment later.

Here, as the binder resin used for forming the charge generation layer as described above, an electrically insulating thermoplastic resin, a thermosetting resin, a photocurable resin, a photoconductive resin, or the like known per se is used. All binder resins can be used. And
Suitable binder resins are not particularly limited to these, but include, for example, polyester, polyvinyl butyral, polyvinyl acetal, (meth) acrylic resin, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, and polyvinyl chloride. There are vinylidene chloride, alkyd resin, urethane resin, phenol resin, phenoxy resin and the like, and these can be used alone or in combination.

In forming the charge transport layer as described above, the charge transport material is anthracene, pyrene, carbazole derivative, tetrazole derivative, metallocene derivative, phenothiazine derivative, pyrazoline compound, hydrazone compound, styryl compound, styrylhydrazone compound, thiazole. A hole transporting substance such as a compound, an oxazole compound, an oxadiazole compound, an imidazole compound, a phenylenediamine derivative and a stilbene derivative, and a polymerized product thereof can be used.

As the binder resin used for forming such a charge transport layer, a known thermoplastic resin, thermosetting resin, or photocurable resin may be used as in the binder resin used for forming the charge generating layer. Any binder resin such as a photoconductive resin can be used. Here, the suitable binder resin is not particularly limited to these,
For example, polymers or copolymers of (meth) acrylic, acrylonitrile, styrene, budadiene, vinyl acetate, vinyl chloride, polycarbonate, polyarylate, polyester, polysulfone, polyether sulfone, polyamide, epoxy, urethane, alkyd, silicone, etc. And these can be used alone or in combination.

[Examples] Next, photoreceptors according to specific examples of the present invention will be described, and comparative examples will be given to clarify that the photoreceptors according to the examples of the present invention are excellent.

(Example 1) In this example, α-type titanyl phthalocyanine was used as a charge generating material, 1 part by weight of this α-type titanyl phthalocyanine, 1 part by weight of polyvinyl butyral resin (ESREC BL-S), and 98 parts by weight of cyclohexanone were used. Use a paint conditioner to apply a mixed solution consisting of
Dispersed for hours.

Then, 0.1 part by weight of 6-aminoindazole was added to the thus obtained dispersion liquid, and this was dissolved to prepare a coating liquid for the charge generation layer.

A cylindrical aluminum tube is used as the conductive support, and the coating solution for the charge generation layer is applied onto the aluminum tube by a dipping method so that the film thickness after drying is 0.2 μm. Was dried to form a charge generation layer on the aluminum tube.

Then, 10 parts by weight of a butadiene compound represented by the following structural formula [1] as a charge transport material in a resin solution prepared by dissolving 10 parts by weight of polycarbonate (K-1300 manufactured by Teijin Chemicals Ltd.) in 90 parts by weight of dichloromethane. A part was dissolved to prepare a coating solution for the charge transport layer.

Then, on the charge generation layer formed on the aluminum tube as described above, the coating solution for this charge transfer layer was applied by a dipping method so that the film thickness after drying was 20 μm, and this was dried. A charge-transporting layer was formed, and a function-separated type laminated photoreceptor in which a charge-generating layer and a charge-transporting layer were laminated on an aluminum tube was obtained.

Example 2 In this example, 6 was used as the compound contained in the coating liquid for the charge generation layer in Example 1 above.
-In place of aminoindazole, 0.1 part by weight of 5-aminoindole was added, and otherwise, in the same manner as in Example 1 above, the charge separation layer and the charge transport layer were laminated to form a function-separated type. A laminated photoreceptor was obtained.

(Example 3) In this example, 6 used in Example 1 was used as a compound to be contained in the coating liquid for the charge generation layer.
In place of -aminoindazole, 0.1 part by weight of N-aminocarbazole was added, and otherwise,
In the same manner as in Example 1 above, a function-separated type laminated photoconductor in which a charge generation layer and a charge transport layer were laminated was obtained.

(Example 4) In this example, the amount of N-aminocarbazole added to the coating liquid for the charge generation layer in Example 3 was 0.5 part by weight, and the other conditions were the same as in Example 1 above. In the same manner, a function-separated type laminated photoreceptor in which a charge generation layer and a charge transport layer were laminated was obtained.

(Example 5) In this example, the addition amount of N-aminocarbazole contained in the coating liquid for the charge generation layer in Example 3 was set to 1 part by weight, and otherwise the same as in Example 1 above. In the same manner, a function-separated type laminated photoreceptor in which a charge generation layer and a charge transport layer were laminated was obtained.

Example 6 In this example, as the charge generation material, ε-type copper phthalocyanine was used in place of the α-type titanyl phthalocyanine used in Example 1 above, and otherwise, as in Example 1 above. In the same manner, a function-separated type laminated photoreceptor in which a charge generation layer and a charge transport layer were laminated was obtained.

Comparative Example 1 In this comparative example, the coating liquid for the charge generation layer in Example 1 above did not contain 6-aminoindazole, and otherwise the same as in Example 1 above except that the charge generation layer was formed. A function-separated type laminated photoreceptor was obtained by laminating a charge transport layer and a charge transport layer.

(Comparative Example 2) In this Comparative Example, a carbazole having no primary amine group was used instead of N-aminocarbazole contained in the coating solution for a charge generation layer in Example 3 above. In the same manner as in Example 1 except for the above, a function-separated type laminated photoreceptor in which a charge generation layer and a charge transport layer were laminated was obtained.

(Comparative Examples 3 and 4) In these Comparative Examples, instead of 6-aminoindazole contained in the coating liquid for the charge generation layer in Example 1 above, an indole compound or a compound other than an indazole compound was used. And in Comparative Example 3, 1
-Aminonaphthalene is contained in Comparative Example 4 to contain 2-aminoanthracene, and otherwise the same as in Example 1 above, except that the charge generation layer and the charge transport layer are laminated. A separate type laminated photoreceptor was obtained.

(Comparative Example 5) In this comparative example, as the charge generation material, the above-mentioned Example 5 was used.
The same ε-type copper phthalocyanine as described above was used, but 6-aminoindazole was not contained in the coating liquid for the charge generation layer, and otherwise the same as in Example 1 above, the charge generation layer and the charge were generated. A function-separated type laminated photoconductor was obtained by laminating a transport layer.

Then, for each of the photoconductors of Examples 1 to 6 and Comparative Examples 1 to 5 obtained as described above, the reception potential V ₀ [V] and the half-exposure amount E _1/2 [erg] at the initial stage of each photoconductor. / cm ² ]
And the receptive potential V ₀ and half-exposure amount E _1/2 of each photoconductor after repeating charging and discharging 3000 cycles,
The repeated stability of each photoconductor was compared.

For this measurement, a commercially available electrophotographic laser beam printer (SP-348 manufactured by Nissho Electronics)
Was used so that the receptive potential V ₀ and the half-exposure amount E _1/2 on the surface of the photoconductor can be measured.

Then, each of the above-mentioned photoconductors was incorporated into this modified laser beam printer, the grid voltage of the scorotron charger was set so that the receptive potential was about −700V, and the surface of each photoconductor was electrified. receptor potential V ₀ which and half-decay exposure E _1/2 of the photoreceptor was measured, further charged was measured receiving potential V ₀ which and half-decay exposure E _1/2 of each photoconductor in after repeating 3000 cycles neutralization.

 The measurement results were as shown in Table 1 below.

As is clear from these results, the photoreceptors of Examples 1 to 6 above were compared with the photoreceptors of Comparative Examples 1 to 5 in the initial potential and after 3000 cycles of acceptance potential and half-exposure amount. The change was markedly small, and the repeated stability was excellent.

[Effects of the Invention] As described in detail above, in the present invention, the phthalocyanine compound is used as the charge generating material in the laminated type photoreceptor in which the charge generating layer and the charge transporting layer are provided on the conductive support. Since the charge generation layer is made to contain an indole compound having a primary amine group and / or an indazole compound having a primary amino group, even when the photoreceptor is repeatedly used, its receptive potential, sensitivity, etc. The change in characteristics was remarkably reduced, and a photoreceptor having excellent repeated stability was obtained.

Claims (1)

(57) [Claims] 1. A charge generation layer containing at least a phthalocyanine compound, which is a charge generation material, and an indole compound having a primary amino group and / or an indazole compound having a primary amino group, on a conductive support. And a charge transport layer.