JPH05346674A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the electrophotographic sensitive body which has an excellent sensitivity characteristic and is useful for high-speed printers, high-speed digital copying machines or high-speed facsimiles, the electrophotographic sensitive body which is less changed in the sensitivity characteristic with a fluctuation in humidity and the electrophotographic sensitive body having stable characteristics in repetitive use. CONSTITUTION:Fluorotitanyl phthalocyanine of a crystal type having peaks at 6.8+ or -0.2 deg., 15.9 deg.+ or -0.2 deg., 25.3+ or -0.2 deg. of Bragg angle 2theta in X-ray diffraction spectra to Cu-Kalpha rays and polyalkylene glycol having the mol. wt. ranging from 110 to 2000 in a 0.1 to 1000 pts.wt. range to 100 pts.wt. fluorotitanyl phthalocyanine are incorporated into photosensitive layers 4, 4', 4''.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
In particular, titanyl phthalocyanine having a specific crystal type is used as a photoconductive material, it is effective for a printer, a copying machine and the like, and is also suitable when an image is formed by using a semiconductor laser light and an LED light as an exposing means. Electrophotographic photoconductor.

[0002]

2. Description of the Related Art In recent years, photoconductive materials have been actively researched and applied to photoelectric conversion elements such as electrophotographic photoreceptors, solar cells and image sensors. Conventionally, inorganic materials are mainly used for these photoconductive materials. For example, in an electrophotographic photoreceptor, a photosensitive layer containing an inorganic photoconductive material such as selenium, zinc oxide, or cadmium sulfide as a main component is provided. Inorganic photoreceptors have been widely used.

However, such an inorganic photoconductor has not always been satisfactory in characteristics such as photosensitivity, thermal stability, moisture resistance and durability required for electrophotographic photoconductors for copying machines, printers and the like. For example, selenium is crystallized by heat, stains on fingerprints, etc., so that the characteristics as an electrophotographic photoreceptor are likely to deteriorate. Further, the electrophotographic photoreceptor using cadmium sulfide is inferior in moisture resistance and durability, and the electrophotographic photoreceptor using zinc oxide also has a problem in durability.

Further, in recent years, environmental problems have been particularly emphasized, but electrophotographic photoreceptors such as selenium and cadmium sulfide have a drawback in that they are severely restricted in production and handling in terms of toxicity.

In order to improve such defects of the inorganic photoconductive material, various organic photoconductive materials have been attracting attention, and it has been attempted to be used for a photosensitive layer of an electrophotographic photoreceptor in recent years. Active research is being conducted. For example, Japanese Patent Publication No. 50-10496 discloses an organic photoreceptor having a photosensitive layer containing polyvinylcarbazole and trinitrofluorenone. However, this photoreceptor is not sufficient in sensitivity and durability. Therefore, a function-separated type electrophotographic photosensitive member has been developed in which different substances have different functions of carrier generation and carrier transport.

In such an electrophotographic photosensitive member, since a wide range of materials can be selected, it is easy to obtain arbitrary characteristics,
Therefore, it is expected that an organic photoreceptor having high sensitivity and high durability can be obtained.

Various organic compounds have been proposed as the carrier-generating substance and the carrier-transporting substance of such a function-separated type electrophotographic photosensitive member, but the carrier-generating substance is particularly important for controlling the basic characteristics of the photosensitive member. Has various functions. As the carrier-generating substances, photoconductive substances such as polycyclic quinone compounds represented by dibromoanthanthrone, pyrylium compounds and eutectic complexes of pyrylium compounds, squarylium compounds, phthalocyanine compounds, and azo compounds have been put to practical use. It was

Recently, in US Pat. No. 5,055,368, an X-ray diffraction spectrum for Cu-Kα has a Bragg angle of 2θ of 6.
It is disclosed that crystalline type fluorotitanyl phthalocyanine having peaks at 8 ± 0.2 °, 15.9 ± 0.2 °, and 25.3 ± 0.2 ° exhibits excellent properties. An electrophotographic photosensitive member using this as a carrier generating substance is useful for designing a high speed printer, a high speed digital copying machine, a high speed facsimile and the like.

However, this electrophotographic photosensitive member has a drawback that its characteristics change in a low temperature and low humidity environment.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photosensitive member which has excellent sensitivity characteristics and is useful for a high speed printer, a high speed digital copying machine or a high speed facsimile.

Another object of the present invention is to provide an electrophotographic photosensitive member which has a small change in sensitivity characteristics with respect to humidity fluctuations.

Another object of the present invention is to provide an electrophotographic photosensitive member having stable characteristics upon repeated use.

[0013]

The above object of the present invention is Cu-
In an X-ray diffraction spectrum for Kα rays, an electrophotographic photoreceptor using crystalline fluorotitanyl phthalocyanine having a peak at 6.8 ± 0.2 °, 15.9 ± 0.2 °, and 25.3 ± 0.2 ° of Bragg angle 2θ as a carrier generating substance,
In the photosensitive layer, it is preferable to use fluorotitanyl phthalocyanine 100 in the same layer as the fluoro titanyl phthalocyanine in the same layer as the polyalkylene glycol having a molecular weight of 110 to 2000.
This can be achieved by containing 0.1 to 500 parts by weight with respect to parts by weight.

The chemical structure of fluorotitanyl phthalocyanine used in the present invention is represented by the following general formula [I].

[0015]

[Chemical 1]

The X-ray diffraction spectrum is measured under the following conditions, and the peak here is a protrusion having a distinct acute angle different from noise.

X-ray tube Cu voltage 40.0 KV current 100 mA start angle 6.0 deg. Stop angle 35.0 deg. Step angle 0.02 deg. Measurement time 0.50 sec. The synthesis and crystal transformation of the fluorotitanyl phthalocyanine used in the present invention followed US Pat. No. 5,055,368.

The polyalkylene glycol used together with these fluorotitanyl phthalocyanines is polyethylene glycol, polypropylene glycol, polybutylene glycol or polytetramethylene glycol, and those having a molecular weight of 110 to 2000 are used. Among them, those having a molecular weight of 110 to 500 are preferable, and diethylene glycol, triethylene glycol and tetraethylene glycol are particularly preferable.

Polyethylene glycol is used in the range of 0.1 to 500 parts by weight based on 100 parts by weight of fluorotitanyl phthalocyanine. This is because if it is less than this range, the effect is insufficient, and if it is more than this range, the sensitivity characteristics of the photoreceptor are deteriorated.

In the electrophotographic photosensitive member of the present invention, other photoconductive substances may be used in combination with the above-mentioned phthalocyanine. Other photoconductive substances include titanyl phthalocyanines such as A, B, C, amorphous and AB mixed types which are different in crystal form from the titanyl phthalocyanines used in the present invention, other phthalocyanine compounds, naphthalocyanine compounds, and other porphyrins. Examples thereof include derivatives, azo compounds, polycyclic quinone compounds represented by dibromoanthanthrone, pyrylium compounds, eutectic complexes of pyrylium compounds, and squarylium compounds.

A carrier-transporting substance may be used in combination with the electrophotographic photoreceptor of the present invention. Although various substances can be used as the carrier-transporting substance, typical examples thereof include compounds having a nitrogen-containing heterocyclic nucleus represented by oxazole, oxadiazole, thiazole, thiadiazole, imidazole and the like, and a condensed ring nucleus thereof, poly Arylalkane compounds, pyrazoline compounds, hydrazone compounds, triarylamine compounds, styryl compounds,
Examples thereof include polis (bis) styryl compounds, styryltriphenylamine compounds, β-phenylstyryltriphenylamine compounds, butadiene compounds, hexatriene compounds, carbazole compounds, condensed polycyclic compounds and the like. Specific examples of these carrier-transporting substances include the carrier-transporting substances described in JP-A-61-107356, and the structures of particularly representative ones are shown below.

[0022]

[Chemical 2]

[0023]

[Chemical 3]

[0024]

[Chemical 4]

[0025]

[Chemical 5]

[0026]

[Chemical 6]

[0027]

[Chemical 7]

Various forms of the photoconductor are known. The photoconductor of the present invention may take any of these forms, but it is desirable to use a laminated or dispersed function-separated photoconductor. In this case, normally, the configuration is as shown in FIG. 1A to FIG. In the layer structure shown in FIG. 1A, a carrier generation layer 2 is formed on a conductive support 1, a carrier transport layer 3 is laminated on the carrier generation layer 2, and a photosensitive layer 4 is formed. () Is a photosensitive layer 4'in which the carrier generating layer 2 and the carrier transporting layer 3 are reversed. In FIG. 3C, an intermediate layer 5 is provided between the photosensitive layer 4 having the layer structure of (1) and the conductive support 1. The layer structure of (5) in the figure is one in which a photosensitive layer 4 ″ containing a carrier generating substance 6 and a carrier transporting substance 7 is formed,
In (6), an intermediate layer 5 is provided between such a photosensitive layer 4 ″ and the conductive support 1. In the configurations of FIGS. 1 (1) to (6), the outermost layer is Furthermore, a protective layer can be provided.

In forming the photosensitive layer, it is effective to apply a solution in which the carrier generating substance or the carrier transporting substance is dissolved alone or together with a binder and an additive. However, since the solubility of the carrier-generating substance is generally low, in such a case, the carrier-generating substance is dispersed by an ultrasonic disperser,
A method of applying a liquid in which fine particles are dispersed in an appropriate dispersion medium by using a dispersing device such as a ball mill, a sand mill, a homomixer is effective. In this case, the binder and additives are usually used by adding them to the dispersion liquid.

A wide variety of solvents or dispersion media can be used as the solvent or dispersion medium for forming the photosensitive layer. For example, butylamine, ethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, 4-methoxy-4-methyl-2-pentanone, tetrahydrofuran, dioxane, ethyl acetate, butyl acetate,
Acetic acid-t-butyl, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, toluene, xylene, acetophenone, chloroform, dichloromethane, dichloroethane, trichloroethane, methanol, ethanol, propanol, butanol and the like can be mentioned.

When a binder is used for forming the carrier generating layer or the carrier transporting layer, any binder can be selected, but a high molecular polymer having hydrophobicity and film forming ability is particularly desirable. Examples of such a polymer include the following,
It is not limited to these. Polycarbonate Polycarbonate Z resin Acrylic resin Methacrylic resin Polyvinyl chloride Polyvinylidene chloride Polystyrene Styrene-butadiene copolymer Polyvinyl acetate Polyvinyl formal Polyvinyl butyral Polyvinyl acetal Polyvinylcarbazole Styrene-alkyd resin Silicone resin Silicone-alkyd resin Silicone-butyral resin Polyester Polyurethane Polyamide Polyamide Epoxy Resin Phenolic resin Vinylidene chloride-acrylonitrile copolymer Vinyl chloride-Vinyl acetate copolymer Vinyl chloride-Vinyl acetate-Maleic anhydride copolymer The ratio of the carrier-generating substance to the binder is preferably 10 to 600% by weight, and further 50 It is desirable to set it to 400% by weight. The ratio of carrier transport material to binder is
It is desirable to be 10 to 500% by weight. The thickness of the carrier generation layer is 0.01 to 20 μm, and more preferably 0.05 to 5 μm. The thickness of the carrier transport layer is 1 to 100 μm, more preferably 5 to 30 μm.

The photosensitive layer may contain an electron accepting substance for the purpose of improving sensitivity, reducing residual potential, or reducing fatigue during repeated use. Examples of such an electron accepting substance include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride and 4-nitrophthalic anhydride. Acid, pyromellitic dianhydride, mellitic dianhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, p-nitrobenzonitrile, picryl chloride, Quinone chlorimide, chloranil, bromanil, dichlorodicyano-p-benzoquinone, anthraquinone, dinitroanthraquinone, 9-fluorenylidene malononitrile, polynitro-9-fluorenylidene malononitrile, picric acid, o-nitrobenzoic acid, p- Nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid Acid, 5-nitro salicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, and larger compounds of other electron affinity. The addition ratio of the electron-accepting substance is 0.0 with respect to 100 by weight of the carrier-generating substance.
It is preferably 1 to 200, more preferably 0.1 to 100.

Further, in the above-mentioned photosensitive layer, storability, durability,
For the purpose of improving the resistance to environment, a deterioration inhibitor such as an antioxidant or a light stabilizer can be contained. Examples of compounds used for such purpose include chromanol derivatives such as tocopherol and etherified or esterified compounds thereof, polyarylalkane compounds,
Hydroquinone derivatives and mono- and dietherified compounds thereof, benzophenone derivatives, benzotriazole derivatives, thioether compounds, phosphonic acid esters, phosphorous acid esters, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds,
Cyclic amine compounds and hindered amine compounds are effective. Specific examples of particularly effective compounds include "IRGANOX
"1010", "IRGANOX 565" (manufactured by Ciba Geigy), "Sumilyzer BHT", "Sumilyzer MDP" (manufactured by Sumitomo Chemical Co., Ltd.), and other hindered phenolic compounds "Sanol LS-2626",
Examples thereof include hindered amine compounds such as "Sanol LS-622LD" (manufactured by Sankyo Co., Ltd.).

As the binder used for the intermediate layer, the protective layer and the like, those mentioned above for the carrier generating layer and the carrier transporting layer can be used, but in addition to them, nylon resin, ethylene-vinyl acetate copolymer, Ethylene resins such as ethylene-vinyl acetate-maleic anhydride copolymers and ethylene-vinyl acetate-methacrylic acid copolymers, polyvinyl alcohol, cellulose derivatives and the like are effective.
Further, a curable binder utilizing heat curing or chemical curing of melamine, epoxy, isocyanate or the like can be used.

As the conductive support, a metal plate or a metal drum is used, and a conductive polymer, a conductive compound such as indium oxide, or a thin layer of a metal such as aluminum or palladium is applied, vapor-deposited, laminated or the like. Accordingly, a material provided on a substrate such as paper or plastic film can be used.

[0036]

EXAMPLES The present invention will be described in detail with reference to examples.

Example 1 To 1 part by weight of the fluorotitanyl phthalocyanine powder of the present invention, 100 parts by weight of methyl ethyl ketone and 0.25 parts by weight of triethylene glycol (molecular weight 150) were added and dispersed using a sand mill. On the other hand, a thickness of polyamide resin "CM-8000" (manufactured by Toray Industries, Inc.) manufactured by a wire bar coating method on a polyester base on which aluminum is vapor-deposited.
After providing an undercoat layer of 0.2 μm, the obtained dispersion liquid was applied to a wire bar to form a carrier generation layer having a thickness of 0.2 μm. Next, 1 part by weight of carrier-transporting substance (1) and polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) 1.5
A solution prepared by dissolving 8 parts by weight of 1,2-dichloroethane in a part by weight and a small amount of silicone oil "KF-54" (manufactured by Shin-Etsu Chemical Co., Ltd.) was blade coated to form a carrier transport layer having a thickness of 20 µm. The photoreceptor thus obtained is referred to as Sample 1.

Examples 2 to 4 The same as Example 1 except that tetraethylene glycol (molecular weight 194), polyethylene glycol having a molecular weight of 500 and triprobylene glycol (molecular weight 192) were used in place of triethylene glycol. To obtain a photoconductor of the present invention. This will be referred to as Samples 2 to 4.

Comparative Example (1) A comparative photoconductor was obtained in the same manner as in Example 1 except that triethylene glycol was omitted. This is designated as Comparative Sample (1).

Comparative Examples (2) to (4) The same as Example 1 except that diethylene glycol (molecular weight 106), polyethylene glycol having a molecular weight of 2500 and polypropylene glycol having a molecular weight of 3000 were used in place of triethylene glycol in Example 1. To obtain a comparative photoconductor. These are designated as comparative samples (2) to (4), respectively.

Comparative Example (5) A comparative photoconductor was obtained in the same manner as in Example 1 except that the amount of triethylene glycol was changed to 6 parts by weight. This is designated as Comparative Sample (5).

Comparative Example (6) In Example 1, the amount of triethylene glycol was 0.0005.
A comparative photoconductor was obtained in the same manner as in Example 1 except that the parts by weight were used. This is designated as Comparative Sample (6).

[Evaluation 1] The obtained sample was tested at 20 ° C. and 50%.
RH of "Konica 9028" under the environment (manufactured by Konica Corp., a semiconductor laser light source used) is mounted on a modified machine, to adjust the grid voltage V _G to -750 V, the time of light irradiation of the non-exposed portion potential V _H and 0.7mW The electric potential V _L of the exposed portion of was measured. Then sample 10
After moving to an environment of 20 ° C. and 20% RH and acclimatizing to the environment sufficiently, V _H and V _L were measured under the above-mentioned conditions. In addition, V after repeated use of 10,000 prints in an environment of 10 ° C and 20% RH
_H and V _L were also measured together.

The evaluation results are shown in Table 1. It can be seen that the alkyl diol of the present invention shows a remarkable effect in reducing fluctuations in humidity and changes in photoreceptor characteristics due to repeated use.

[0045]

[Table 1]

As is clear from Table 1, the samples of the present invention are effective in reducing fluctuations in humidity and changes in photoreceptor characteristics due to repeated use.

[0047]

According to the constitution of the present invention, the stability and durability of the photoconductor can be remarkably improved, and a photoconductor that can withstand high speed copying and facsimiles can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of a photoconductor of the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Carrier Generation Layer 3 Carrier Transport Layer 4 Photosensitive Layer 5 Intermediate Layer 6 Carrier Generation Material 7 Carrier Transport Material

Front Page Continuation (72) Inventor Akira Kinoshita Konica Stock Company, 1st Sakura-cho, Hino City, Tokyo (72) Inventor Kazuma Watanabe 1st Konica Stock Company, Sakura-cho, Hino-shi, Tokyo In-house (72) Inventor Kiyoshi Tamaki Konica Stock Company, 2970 Ishikawa-cho, Hachioji-shi, Tokyo (72) Inventor Yoshihide Fujimaki Konica Stock Company, 2970, Ishikawa-cho, Hachioji-shi, Tokyo

Claims (1)

[Claims] 1. An X-ray diffraction spectrum for Cu-Kα rays having a Bragg angle of 2θ of 6.8 ± 0.2 ° and 15.9 ± 0.2.
Containing crystalline form of fluorotitanyl phthalocyanine having a peak at 20 °, 25.3 ± 0.2 ° and a molecular weight of 110-200
An electrophotographic photosensitive member comprising a polyalkylene glycol in the range of 0 in an amount of 0.1 to 500 parts by weight based on 100 parts by weight of fluorotitanyl phthalocyanine.