JPH0829999A - Photoreceptor for electrophotography - Google Patents

Abstract

PURPOSE:To provide a photoreceptor for electrophotography, which has the excellent sensitivity to the long wavelength light and which is especially appropriate for a recording device using the semiconductor laser light as a light source, by including the specified titanylphthalocyanine pigment in a photosensitive layer, and containing the titanium oxide at a high purity and the binding resin in the intermediate layer. CONSTITUTION:A photosensitive layer contains titanylphthalo-cyanine pigment, which has the main peak of the Bragg angle 2theta at 9.0+ or -0.2 deg. and 27.2 deg.C+ or -0.2 deg. in the X-ray analysis spectrum using Cu-Kalpha characteristic X-ray (wavelength at 1.54Angstrom ). An intermediate layer includes titanium oxide (P) at 99.0% by weight of purity and the binding resin (R). Ratio thereof P/R is set within a range of volume ratio at 0.8/1-3/1. Base structure of the titanylphthalocyanine pigment used for this photosensitive layer is expressed with the formula. In the formula, X1, X2, X3, X4 respectively mean variable halogen atom, and (n), (m), (l), (k) respectively mean the integer at 0-4.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
In particular, the present invention relates to an electrophotographic photoreceptor containing a specific titanyl phthalocyanine pigment, which is suitable for use in laser printers, digital copying machines and laser facsimiles.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as Se, CdS and ZnO have been used as photoconductive materials for electrophotographic photoreceptors, but in recent years they have problems of photosensitivity, thermal stability and toxicity. Now, electrophotographic photoreceptors using organic photoconductive materials are being actively developed. The reasons are that the electrophotographic photosensitive member using the organic photoconductive material is inexpensive, suitable for mass production, non-polluting, and has a high degree of freedom in selecting materials. Further, a function-separated type photoreceptor having a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance has been proposed, and further high sensitivity and high durability are expected.

On the other hand, in the copying industry, in recent years, high image quality, editing function and composite processing function have been demanded. Along with this, non-impact printer technology has developed, and digital recording devices found in laser printers, laser facsimiles, digital copying machines, etc. are becoming widespread. As a light source used in the digital recording apparatus, a semiconductor laser is mostly used because of its small size, low cost, simplicity, etc., but the oscillation wavelength of the currently used semiconductor laser is 750 n.
It is limited to the near infrared region of m or more. Therefore, the electrophotographic photosensitive member used in these devices is required to have photosensitivity in the wavelength region of at least 750 to 850 nm.

[0004] As organic photoconductive materials satisfying this requirement, squarylium pigments, phthalocyanine pigments, eutectic complexes of pyrylium dyes and polycarbonates, pyrrolopyrrole pigments, azo pigments and the like are known. Since it has a spectral absorption up to a relatively long wavelength region and has photosensitivity, and various variations can be obtained depending on the type of central metal and crystal form, it is actively researched as an electrophotographic photoreceptor for a semiconductor laser. ing.

Examples of phthalocyanine pigments having a good sensitivity known so far include ε-type copper phthalocyanine, X-type metal-free phthalocyanine, τ-type metal-free phthalocyanine, vanadyl phthalocyanine, titanyl phthalocyanine, and the like. In terms of sensitivity, chargeability, and repeated durability, they are still insufficient, and further improvements have been desired. On the other hand, in recent years, with respect to higher sensitivity, JP-A-3-128973 and JP-A-3-25005.
A high-sensitivity titanyl phthalocyanine pigment has been proposed in Japanese Patent Laid-Open No. 9-98182 and Japanese Patent Laid-Open No. 5-98182. In the X-ray diffraction spectrum using Cu-Kα characteristic X-ray (wavelength 1.54Å), this pigment has a main peak of Bragg angle 2θ of at least 9.0 ° ± 0.2 ° and 27.
2 ° ± 0.2 ° or 2 main peaks at Bragg angle 2θ
It is only at 7.2 ° ± 0.2 ° and has an X-ray diffraction spectrum different from that of the conventionally known titanyl phthalocyanine pigment. The spectral absorption is 780 nm to 86.
It exhibits a maximum absorption at 0 nm and exhibits extremely high sensitivity to semiconductor laser light.

However, when this high-sensitivity titanyl phthalocyanine pigment is used in an electrophotographic photoreceptor, it has a sufficient sensitivity, but it has a low resistance, a small charging ability, and a repetitive durability remarkably inferior. There are many problems to be put to practical use, together with image defects such as background stains and black spots during reversal development.

As described above, JP-A-3-128973, JP-A-3-250059, and JP-A-5-98.
Although the titanyl phthalocyanine pigment disclosed in Japanese Patent No. 182 has high sensitivity, it still has problems in chargeability, repetitive durability, background stain and black spots during reversal development. For this problem, it has been proposed to provide an intermediate layer between the conductive support and the photosensitive layer. For example, JP-A-3-2481
61 (provided with a layer made of alkoxymethylated nylon), JP-A-3-33856 (provided with a layer made of a thermosetting resin), JP-A-3-37669 (poorly soluble or insoluble in alcoholic solvent) Provided with a layer composed of the resin of 1.) and the like.

However, even these methods are not sufficient for the above problems, and even if they are sufficient, problems such as a marked decrease in sensitivity occur, and the properties have been satisfactory so far. No electrophotographic photoreceptor has been obtained. The present invention solves the above conventional problems.

[0009]

Therefore, an object of the present invention is that it has good sensitivity to long-wavelength light, and is particularly suitable for a recording device such as a copying machine or a printer using a semiconductor laser light as a light source. An object is to provide an electrophotographic photoreceptor.
Another object of the present invention is to provide an electrophotographic photosensitive member which solves the problems of image defects, especially background stains and black spots during reversal development. Still another object of the present invention is to provide an electrophotographic photosensitive member which has a small decrease in charging property even after repeated use and a small increase in residual potential and is extremely excellent in durability.

[0010]

According to the present invention, firstly, in an electrophotographic photosensitive member comprising an electrically conductive support, and an intermediate layer and a photosensitive layer sequentially laminated, said photosensitive layer is Cu-Kα.
In an X-ray diffraction spectrum using characteristic X-rays (wavelength: 1.54Å), a titanyl phthalocyanine pigment having main Bragg angles 2θ of at least 9.0 ° ± 0.2 ° and 27.2 ° ± 0.2 °. And an intermediate layer containing titanium oxide (P) having a purity of 99.0% by weight or more and a binder resin (R). Secondly, in an electrophotographic photoreceptor having an intermediate layer and a photosensitive layer sequentially laminated on a conductive support, the photosensitive layer has a Cu-Kα characteristic X-ray (wavelength 1.54).
X-ray diffraction spectrum using Å) contains a titanyl phthalocyanine pigment whose main peak at Bragg angle 2θ is only 27.2 ° ± 0.2 °, and the intermediate layer has a purity of 99.0% by weight or more. There is provided an electrophotographic photoreceptor comprising the titanium oxide (P) and the binder resin (R). . Thirdly, the ratio P / R of titanium oxide (P) and the binder resin (R) contained in the intermediate layer is in the range of 0.8 / 1 to 3/1 in terms of volume ratio. The above electrophotographic photoreceptor is provided.

The basic structure of the titanyl phthalocyanine pigment used in the present invention is represented by the following general formula (I) (Formula 1).

Embedded image (In the formula, X ₁ , X ₂ , X ₃ and X ₄ each independently represent various halogen atoms, and n, m, l and k each independently represent a number of 0 to 4)

The titanyl phthalocyanine pigment according to the present invention is obtained by aggregating and crystallizing the titanyl phthalocyanine having the above-mentioned basic structure, and in the X-ray diffraction spectrum using Cu-Kα characteristic X-ray (wavelength 1.54Å). , The main peak of Bragg angle 2θ is at least 9.0 ° ± 0.
2 ° and 27.2 ° ± 0.2 ° or Bragg angle 2
It has a crystal form in which the main peak of θ is only 27.2 ° ± 0.2 °. Of these, the crystal form in which the main peak of the Bragg angle 2θ is only 27.2 ° ± 0.2 ° is
The intensity (comparison of peak heights) of any peaks higher than 27.2 ° ± 0.2 ° is 35.
% Or less. These crystalline titanyl phthalocyanine pigments have an absorption peak in the visible / near infrared spectrum in the range of 780 nm to 860 nm, and have extremely high sensitivity to semiconductor laser light as compared with other crystalline forms.

The intermediate layer of the electrophotographic photosensitive member of the present invention contains titanium oxide (P). Titanium oxide is white with almost no absorption of visible light and near infrared light, and is desirable for increasing the sensitivity of the photoconductor. In addition, since the refractive index is relatively large, it is possible to effectively prevent moire generated when writing an image with coherent light such as laser light.

Further, the titanium oxide which can be used in the present invention preferably has a purity of 99.0 wt%. The impurities contained in titanium oxide are mainly hygroscopic substances such as Na ₂ O and K ₂ O. When the purity of titanium oxide is lower than 99.0% by weight, the characteristics of the photoconductor are environmental (particularly humidity). ) Causes a large fluctuation.

Further, the ratio P / R of titanium oxide (P) and the binder resin (R) contained in the intermediate layer of the present invention is in the range of 0.8 / 1 to 3/1 in terms of volume ratio. preferable. If the P / R ratio of the intermediate layer is less than 0.8 / 1, the characteristics of the intermediate layer are influenced by the characteristics of the binder resin, and the characteristics of the photoconductor greatly change especially with changes in temperature and humidity. On the other hand, when the P / R ratio exceeds 3/1, the number of voids increases in the intermediate layer, and air is accumulated. This causes bubbles during coating and drying of the photosensitive layer, resulting in coating defects.

The present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a constitutional example of the electrophotographic photosensitive member of the present invention, which comprises an electroconductive support 11 and an intermediate layer 13 containing titanium oxide having a purity of 99.0% by weight or more and a binder resin. Photosensitive layer containing a titanyl phthalocyanine pigment according to the invention 1
5 is laminated. 2 and 3 are cross-sectional views showing another configuration example of the present invention. The photosensitive layer 15 is composed of a charge generation layer 17 containing a titanyl phthalocyanine pigment and a charge transport layer 19. FIG. 4 is a cross-sectional view showing still another configuration example of the present invention, in which a protective layer 21 is provided on the photosensitive layer 15.

As the conductive support 11, the volume resistance 10
Those exhibiting conductivity of ¹⁰ Ω · cm or less, for example, metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver and platinum, metal oxide such as tin oxide and indium oxide, by vapor deposition or sputtering, Film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. plates and the like, after being formed into a raw tube by a method such as extrusion or drawing, cutting, superfinishing, polishing, etc. It is possible to use a surface-treated tube or the like. Further, the endless nickel bell and the endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support 11.

In addition to the above, a support obtained by dispersing conductive powder in a suitable binder resin and coating it on the above support can also be used as the conductive support 11 of the present invention. As the conductive powder, carbon black, acetylene black, aluminum, nickel, iron, nichrome, copper, zinc,
Examples thereof include metal powder such as silver, and metal oxide powder such as titanium black, conductive tin oxide, ITO and conductive titanium oxide. Further, the binder resin used at the same time, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride, vinyl chloride-vinyl acetate Copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-
Vinylcarbazole, acrylic resin, silicone resin,
Examples thereof include thermoplastic resins such as epoxy resins, melamine resins, urethane resins, phenol resins and alkyd resins, and thermosetting resins or photocurable resins. Such a conductive layer can be provided by dispersing these conductive powders and a binder resin in a suitable solvent, for example, THF, MDC, MEK, toluene or the like and applying the dispersion.

Further, the heat-shrinkable tube in which the above-mentioned conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and Teflon on a suitable cylindrical substrate is electrically conductive. Those provided with a layer can also be favorably used as the conductive support 11 of the present invention. The charge generation layer 17 may be formed of only the titanyl phthalocyanine pigment, or may be formed by dispersing the titanyl phthalocyanine pigment in the binder resin. Therefore, in the charge generation layer 17, these components are dispersed in a suitable solvent by using a ball mill, an attritor, a sand mill, ultrasonic waves, etc., and the conductive support 11 or the intermediate layer 1 is dispersed.
It is formed by applying on 3 and drying.

As the binder resin used for the charge generation layer 17, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-
Vinylcarbazole, polyacrylamide, polyvinylbenzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. To be The amount of the binder resin is appropriately 0 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the charge generating substance. The thickness of the charge generation layer is 0.01 to 5 μm, preferably 0.1 to 2
μm.

As the solvent used here, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane,
Examples include toluene, xylene, ligroin, and the like. As a coating method of the coating liquid, a dipping coating method, a spray coating method, a beat coating method, a nozzle coating method, a spinner coating method, a ring coating method, or the like can be used.

The charge transport layer 19 can be formed by dissolving or dispersing a charge transport substance and a binder resin in a suitable solvent, coating the resultant on the charge generating layer 17, and drying.
Further, if necessary, a plasticizer, a leveling agent, an antioxidant and the like can be added.

The charge transport material includes a hole transport material and an electron transport material.

Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,
4,8-Trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophene-4
-One, 1,3,7-trinitrodibenzothiophene-
Examples include electron-accepting substances such as 5,5-dioxide and benzoquinone derivatives.

Examples of the hole-transporting substance include poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylgrill tamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, Polysilane, oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative, diarylamine derivative, triarylamine derivative, stilbene derivative, α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9- Styrylanthracene derivative, pyrazoline derivative, divinylbenzene derivative, hydrazone derivative, indene derivative, butadiene derivative, pyrene derivative, bisstilbene derivative, enami Other well-known materials such as a derivative thereof are included. These charge transport materials may be used alone or in combination of two or more.

As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, poly Vinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, Urethane resin,
Thermoplastic or thermosetting resins such as phenolic resins and alkyd resins may be mentioned.

The amount of the charge transport substance is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin.
Parts by weight are suitable. The thickness of the charge transport layer is 5 to 5
It is preferably about 0 μm.

As the solvent used here, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, dichloromethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used.

In the present invention, a plasticizer, a leveling agent and an antioxidant may be added to the charge transport layer 19. As the plasticizer, those used as a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount thereof is preferably about 0 to 30 parts by weight with respect to 100 parts by weight of the binder resin. Is. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used.
0 to 1 part by weight is suitable for 0 part by weight. As the antioxidant, hindered phenol compounds, sulfur compounds, phosphorus compounds, hindered amine compounds, hydroquinone compounds, and other antioxidants used in general resins can be used as they are, and the amount of the binder Resin 100
About 0 to 5 parts by weight is suitable with respect to parts by weight.

Next, the case where the photosensitive layer 15 has a single layer structure will be described. In this case as well, in most cases, a function-separated type of charge-generating substance and charge-transporting substance is used. That is, the titanyl phthalocyanine pigment according to the present invention can be used as the charge generating substance, and the compounds exemplified above as the charge transporting substance can be used. The single-layer photosensitive layer can be formed by dissolving or dispersing the charge-generating substance, the charge-transporting substance and the binder resin in a suitable solvent, coating and drying the solution. If necessary, a plasticizer, a leveling agent, an antioxidant, etc. can be added.

As the binder resin, the binder resins previously mentioned for the charge transport layer 19 may be used as they are, or the charge generation layer 1 may be used.
You may mix and use the binder resin mentioned in 7. A photoreceptor obtained by adding a hole-transporting substance to a Kyosho complex formed of a pyrylium-based dye, bisphenol-based, or polycarbonate can also be used as the single-layer photoreceptor. The single-layer photosensitive layer is a dip coating method, a spray coating method, a beading method, in which a charge generating substance, a charge transporting substance, and a binder resin are dispersed by a disperser using a solvent such as tetrahydrofuran, dioxane, dichloroethane or cyclohexane. It can be formed by coating with a coat or the like. The film thickness of the single-layer photosensitive layer is preferably about 5 to 50 μm.

In the present invention, as shown in FIGS. 1 to 4, an intermediate layer 13 is provided between the conductive support 11 and the photosensitive layer 15. The intermediate layer 13 contains titanium oxide having a purity of 99.0% by weight or more and a binder resin. Considering that the photosensitive layer 15 is coated on the intermediate layer 13 with a solvent, a binder resin that can be used is preferably a resin having a high solvent resistance to a general organic solvent. Examples of such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymer nylon, alcohol-soluble resins such as methoxymethylated nylon, ethylene-vinyl acetate copolymer,
Ethylene resin such as ethylene-vinyl acetate-maleic anhydride copolymer, ethylene-vinyl acetate-methacrylic acid copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, etc. Vinyl chloride resin, cellulose derivative resin, polyurethane, melamine resin, phenol resin, alkyd-melamine resin,
Examples thereof include acrylic-melamine resins, silicone resins, silicone-alkyd resins, epoxy resins, and other curable resins that form a three-dimensional network structure.

The intermediate layer 13 of the present invention can be formed by using an appropriate solvent, dispersion and coating method like the above-mentioned photosensitive layer. Further, as the intermediate layer 13 of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, etc. can be used together. The thickness of the intermediate layer 13 is 0 to 1
0 μm is suitable.

The protective layer 21 is provided for the purpose of protecting the surface of the photoconductor, and the materials used therefor are ABS resin and A
CS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, Polyethylene terephthalate, polyimide, acrylic resin, polymethyl bentene,
Examples thereof include resins such as polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. In addition to the protective layer, a fluororesin such as polytetrafluoroethylene, a silicone resin, and a dispersion of an inorganic material such as titanium oxide, tin oxide, or potassium titanate in these resins for the purpose of improving wear resistance. Can be added.
As a method for forming the protective layer 21, a usual coating method is adopted. The protective layer preferably has a thickness of about 0.1 to 10 μm. In addition to the above, known materials such as aC and a-SiC formed by the vacuum thin film forming method can be used as the protective layer.

In the present invention, it is possible to provide another intermediate layer (not shown) between the photosensitive layer and the protective layer. A general binder resin is used as a main component in the another intermediate layer.
Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble vinyl butyral resin, polyvinyl butyral and polyvinyl alcohol. As a method for forming the another intermediate layer, a usual coating method is adopted as described above. The thickness of the intermediate layer is 0.05 to 2μ.
m is suitable.

[0036]

EXAMPLES The present invention will be described below with reference to examples. First, a specific synthesis example of the titanyl phthalocyanine pigment used in the examples will be described.

(Synthesis Example 1) Phthalodinitrile 52.5 g
(0.41 mol) and 1-chloronaphthalene 300mo
1 with stirring and mixing, under a nitrogen stream, 19.0 g of titanium tetrachloride
(0.10 mol) is added dropwise. Gradually 2 after dropping
The temperature was raised to 00 ° C, and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 190 ° C and 210 ° C. After the reaction was completed, the mixture was allowed to cool and filtered at 130 ° C, then 1
Washed with chloronaphthalene until the powder turned blue, then washed several times with methanol, then several times with hot water at 80 ° C., and then dried to obtain 42.2 g (yield 73.3%) of crude. A titanyl phthalocyanine pigment was obtained. 6 g of the obtained crude titanyl phthalocyanine was added to 100 g of 96% sulfuric acid.
Stirred at ~ 5 ° C, dissolved, and filtered. The obtained sulfuric acid solution was added dropwise to 3.5 liters of ice water with stirring, the precipitated crystals were filtered, and then washed repeatedly with water until the washing liquid became neutral, and dried to obtain 5.8 g of a titanyl phthalocyanine pigment. Next, 100 ml of methanol was added to 4.0 g of the titanyl phthalocyanine pigment treated with acid paste, and suspension stirring treatment was carried out at 30 ° C. for 5 hours. After the treatment, filtration and drying were performed to obtain 3.6 g of a titanyl phthalocyanine pigment. Further, 70 ml of n-butyl ether was added to 3.6 g of the obtained pigment, and milling treatment was performed at room temperature for 24 hours together with 1 mmφ glass beads. Glass beads were removed from this dispersion, filtered, washed with methanol, and dried to obtain 3.4 g of the titanyl phthalocyanine pigment of the present invention.
This pigment has a Bragg angle of 2θ of 9.0 as shown in FIG.
It can be seen that there are major peaks at ° and 27.2 °. The measurement conditions of the X-ray diffraction spectrum are as follows. X-ray tube Cu voltage 40 kV current 20 mA scanning speed 1 ° / min scanning range 3 ° to 35 ° time constant 2 seconds

Synthesis Example 2 35.0 g of 1,3-diiminoisoindoline and 240 ml of α-chloronaphthalene were mixed, and 24.5 g of titanium butoxide was added under a nitrogen atmosphere. The mixture was heated in a nitrogen atmosphere at 140 to 150 ° C. for 2 hours, and further heated to 180 ° C. for reaction for 3 hours. After cooling, the precipitate was filtered and washed with α-chloronaphthalene,
Then, it was thoroughly washed with DMF at 90 ° C., finally washed with methanol and dried to obtain 29.8 g of titanyl phthalocyanine pigment. 4.1 g of the titanyl phthalocyanine pigment obtained as described above was added to trifluoroacetic acid / MDC = 8 m.
It was dissolved in a mixed solvent of 1/32 ml, and this was added dropwise to an ice-cooled mixed solvent of methanol / water = 100 ml / 100 ml with stirring to precipitate crystals, and then allowed to stand. After crystals were precipitated, the supernatant was removed, 100 ml of methanol was added, and the mixture was stirred for 30 minutes and filtered. 200 solids obtained
It was dispersed in ml of hot water and repeatedly washed to obtain a wet cake of titanyl phthalocyanine pigment. Next, disperse this wet cake in 100 ml of monochlorobenzene,
By stirring for 30 minutes, filtering and drying, 3.6 g of the titanyl phthalocyanine pigment according to the present invention was obtained. As shown in FIG. 6, this pigment has a maximum peak at 27.2 ° at a Bragg angle of 2θ, and the intensity of any other peaks (comparison of peak heights) is 27.2 °. ) Is less than 35%. The measurement conditions of the X-ray diffraction spectrum are the same as in (Synthesis example 1).

Example 1 65 parts by weight of titanium oxide (CR-EL: manufactured by Ishihara Sangyo, purity 99.7% by weight), alkyd resin (Beckolite M6
401-50-S (solid content 50%): Dainippon Ink and Chemicals, Inc. 15 parts by weight, melamine resin (Super Beckamine L-121-60 (solid content 60%): Dainippon Ink and Chemicals, Inc.) 10 parts by weight Part and 100 parts by weight of methyl ethyl ketone were dispersed in a ball mill for 24 hours to prepare an intermediate layer coating liquid. This is applied on a 0.2 mm thick aluminum plate (A1080: Sumitomo Light Metal Co., Ltd.), and 130
It was dried at 0 ° C. for 20 minutes to form an intermediate layer having a film thickness of 3 μm. Next, 2 parts by weight of the titanyl phthalocyanine pigment obtained in Synthesis Example 1 and polyvinyl butyral resin (BM-
2: Sekisui Chemical Co., Ltd.) 2 parts by weight of cyclohexanone 10
It was added to 0 parts by weight and dispersed for 2 hours by a sand mill using 1 mmφ glass beads. After the dispersion was completed, 100 parts by weight of methyl ethyl ketone was added and diluted to prepare a charge generation layer coating liquid. This is applied on the intermediate layer,
After drying at 10 ° C. for 10 minutes, a charge generation layer having a thickness of 0.2 μm was formed. Next, 7 parts by weight of a charge transport material represented by the following structural formula (Formula 2) and a polycarbonate resin (Iupilon Z20
0: Mitsubishi Gas Chemical Co., Ltd.) 10 parts by weight and silicone oil (KF-50: Shin-Etsu Chemical Co., Ltd.) 0.002 parts by weight were dissolved in 100 parts by weight of tetrahydrofuran to prepare a coating liquid for charge transport layer. This was applied onto the charge generation layer and dried at 130 ° C. for 15 minutes to form a charge transport layer having a film thickness of 20 μm, and the electrophotographic photoreceptor of Example 1 was obtained.

Embedded image

Example 2 Example 2 was repeated in the same manner as Example 1 except that the titanium oxide in Example 1 was replaced with titanium oxide having a purity of 99.9% by weight (TP-2: manufactured by Fuji Titanium Industry Co., Ltd.). An electrophotographic photoreceptor was created.

Comparative Example 1 An electrophotographic photosensitive member of Comparative Example 1 was prepared in the same manner as in Example 1 except that the intermediate layer was not provided.

Comparative Example 2 An electrophotographic photosensitive member of Comparative Example 2 was prepared in the same manner as in Example 1 except that the intermediate layer in Example 1 was prepared as follows. Alcohol-soluble nylon resin (CM-
8000: manufactured by Toray) 2 parts by weight methanol 80 parts by weight /
It heated and melt | dissolved in the mixed solvent of 20 weight part of n-butanol, and created the coating liquid for intermediate | middle layers. This is applied on a 0.2 mm thick aluminum plate (A1080: Sumitomo Light Metal Co., Ltd.), and 13
It was dried at 0 ° C. for 20 minutes to form an intermediate layer having a film thickness of 0.15 μm.

Comparative Example 3 An electrophotographic photosensitive member of Comparative Example 3 was prepared in the same manner as in Example 1 except that the titanium oxide in Example 1 was replaced with titanium oxide having a purity of 97% by weight (JR: manufactured by Teikoku Kako). did.

Comparative Example 4 An electrophotography of Comparative Example 4 was conducted in the same manner as in Example 1 except that the titanium oxide in Example 1 was replaced with titanium oxide having a purity of 98% by weight (TA-300: manufactured by Fuji Titanium Industry Co., Ltd.). A photoconductor was created.

Example 3 Example 3 was repeated in the same manner as in Example 1 except that the titanium oxide used in Example 1 was replaced with titanium oxide having a purity of 99.0% by weight, after TA-300 was washed with pure water. An electrophotographic photoconductor of was prepared.

The electrophotographic photosensitive member obtained as described above was evaluated for electrostatic characteristics in a dynamic mode using SP-428 (manufactured by Kawaguchi Electric Co., Ltd.) in an environment of 25 ° C./50% RH. First, the photoreceptor is negatively charged by performing corona discharge of 16 kV for 5 seconds, and then the surface potential V ₂ (−V) after 2 seconds.
Was measured, and when the surface potential became −800 V, light (2.8 μW / cm ² ) dispersed at 780 nm with a bandpass filter was exposed, and the surface potential was −40.
Exposure dose E1 / 2 (μJ / cm ² ) required to attenuate light to 0V
And the surface potential V ₃₀ (−V) after 30 seconds of exposure were measured. Further, corona discharge of −6 kV and exposure of a tungsten lamp 45lux having a color temperature of 2856K were repeated 30,000 times, and then the same measurement was performed to evaluate the electrostatic characteristics after fatigue. Table 1 shows the evaluation results.

[0047]

[Table 1]

Example 4 Titanium oxide (TM-1: manufactured by Fuji Titanium Industry, purity 99.
6 parts by weight) 75 parts by weight, acrylic resin (Acridic A-460-60 (solid content 60%): manufactured by Dainippon Ink & Chemicals, Inc.) 15 parts by weight, melamine resin (Super Beckamine G-821-60 (solid content) 60%): manufactured by Dainippon Ink and Chemicals, Inc.) A mixture of 10 parts by weight and 120 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 24 hours to prepare an intermediate layer coating liquid. Apply this to a 0.2 mm thick aluminum plate (A1080: Sumitomo Light Metal Co., Ltd.)
It was dried at 0 ° C. for 20 minutes to form an intermediate layer having a film thickness of 3 μm. The intermediate layer has a specific gravity of titanium oxide of 4.2,
Since the specific gravity of the binder resin is 1.3, the volume ratio of titanium oxide (P) / binder resin (R) is 1.5 / 1. A charge generation layer was formed on this intermediate layer in the same manner as in Example 1.
An electrophotographic photosensitive member of Example 4 was prepared by sequentially stacking charge transport layers.

Examples 5 to 7 and Comparative Examples 5 and 6 The amount of titanium oxide (TM-1 manufactured by Fuji Titanium Industry Co., Ltd., purity 99.6% by weight) in the intermediate layer of Example 4 was changed as shown in Table 2. In the same manner as in Example 4, electrophotographic photoconductors of Examples 5 to 7 and Comparative examples 5 and 6 were prepared.

[0050]

[Table 2]

The electrophotographic photoreceptors of Examples 5 to 7 and Comparative Examples 5 and 6 thus obtained were evaluated for electrostatic properties at the initial stage and after fatigue in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0052]

[Table 3]

Example 8 An electrophotographic photosensitive member of Example 8 was obtained by sequentially laminating an intermediate layer, a charge generation layer and a charge transport layer on an aluminum drum having a diameter of 80 mm and a length of 360 mm in the same manner as in Example 1. Created. However, the thickness of the charge transport layer was 25 μm.

Comparative Example 7 An electrophotographic photosensitive member of Comparative Example 7 was obtained by sequentially stacking an intermediate layer, a charge generation layer and a charge transport layer on an aluminum drum having a diameter of 80 mm and a length of 360 mm in the same manner as in Comparative Example 2. Created. However, the thickness of the charge transport layer was 25 μm.

The electrophotographic photosensitive member obtained as described above was used in Imagio 3
It was set to 20 (manufactured by Ricoh Co., Ltd.), and the initial image and the image quality after copying 50,000 sheets were evaluated. Evaluation is 25 ° C / 50
It was performed under the environment of% RH. The results are shown in Table 4.

[0056]

[Table 4]

Example 8 As in Example 1, an aluminum plate (A1) having a thickness of 0.2 mm was used.
080: Sumitomo Light Metal Co., Ltd.) and apply it at 130 ° C for 20
It was dried for a minute to form an intermediate layer having a film thickness of 3.5 μm. Next, 2 parts by weight of the titanyl phthalocyanine pigment obtained in Synthesis Example 2 and 2 parts by weight of polyvinyl butyral resin (BM-2: Sekisui Chemical Co., Ltd.) were added to 100 parts by weight of cyclohexanone, and 1 mmφ glass beads were used. Dispersion was performed in a sand mill for 2 hours. After the dispersion was completed, 100 parts by weight of methyl ethyl ketone was added and diluted to prepare a charge generation layer coating liquid. This was applied onto the intermediate layer and dried at 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm. Next, 7 parts by weight of a charge transport material represented by the following structural formula (Formula 3), 10 parts by weight of a polycarbonate resin (Upilon Z300: manufactured by Mitsubishi Gas Chemical Co., Inc.), and silicone oil (KF-
50: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.002 parts by weight was dissolved in 100 parts by weight of tetrahydrofuran to prepare a coating liquid for the charge transport layer. This is applied on the charge generation layer, and 130
The film was dried at 15 ° C. for 15 minutes to form a charge transport layer having a film thickness of 20 μm, and the electrophotographic photosensitive member of Example 8 was obtained.

Embedded image

Example 9 Example 9 was repeated in the same manner as Example 8 except that the titanium oxide in Example 8 was replaced with titanium oxide having a purity of 99.9% by weight (TP-2: manufactured by Fuji Titanium Industry Co., Ltd.). An electrophotographic photoreceptor was created.

Comparative Example 8 An electrophotographic photosensitive member of Comparative Example 8 was prepared in the same manner as in Example 8 except that the intermediate layer was not provided.

Comparative Example 9 An electrophotographic photosensitive member of Comparative Example 9 was prepared in the same manner as in Example 8 except that the intermediate layer in Example 8 was prepared as follows. Alcohol-soluble nylon resin (CM-
8000: manufactured by Toray) 2 parts by weight methanol 80 parts by weight /
It heated and melt | dissolved in the mixed solvent of 20 weight part of n-butanol, and created the coating liquid for intermediate | middle layers. This is applied on a 0.2 mm thick aluminum plate (A1080: Sumitomo Light Metal Co., Ltd.), and 13
It was dried at 0 ° C. for 20 minutes to form an intermediate layer having a film thickness of 0.15 μm.

Comparative Example 10 An electrophotographic photosensitive member of Comparative Example 10 was prepared in the same manner as in Example 8 except that the titanium oxide of Example 8 was replaced with titanium oxide having a purity of 97% by weight (JR: manufactured by Teikoku Kako). did.

Comparative Example 11 An electrophotographic photograph of Comparative Example 11 was carried out in the same manner as in Example 8 except that the titanium oxide of Example 8 was replaced with titanium oxide having a purity of 98% by weight (TA-300: manufactured by Fuji Titanium Industry Co., Ltd.). A photoconductor was created.

Example 10 Example 10 was repeated in the same manner as in Example 8 except that the titanium oxide used in Example 8 was replaced with titanium oxide having a purity of 99.0% by weight, after TA-300 was washed with pure water. An electrophotographic photoconductor of was prepared.

The electrostatic characteristics of the electrophotographic photosensitive member obtained as described above were evaluated in the same manner as in Example 1. Two
Under the environment of 5 ° C./50% RH, SP-428 (Kawaguchi Electric Co., Ltd. was evaluated for electrostatic characteristics. The evaluation results are shown in Table 5.

[0065]

[Table 5]

Example 11 An aluminum plate (A1 having a thickness of 0.2 mm) was formed in the same manner as in Example 4.
080: Sumitomo Light Metal Co., Ltd.) to form an intermediate layer having a film thickness of 3.5 μm. Since the intermediate layer has a specific gravity of titanium oxide of 4.2 and a specific gravity of the binder resin of 1.3, the volume ratio of titanium oxide (P) / binder resin (R) is 1.5 / 1.
Becomes A charge generation layer and a charge transport layer were sequentially laminated on this intermediate layer in the same manner as in Example 8 to prepare an electrophotographic photosensitive member of Example 11.

Examples 12 to 14 and Comparative Examples 12 and 13 The amount of titanium oxide (TM-1: manufactured by Fuji Titanium Industry Co., Ltd., purity 99.6% by weight) in the intermediate layer of Example 11 was changed as shown in Table 6. In the same manner as in Example 11
14, and electrophotographic photosensitive members of Comparative Examples 12 and 13 were prepared.

[0068]

[Table 6]

Examples 11 to 1 thus obtained
4. In the same manner as in Example 1, the electrophotographic photoreceptors of Comparative Examples 12 and 13 were evaluated for electrostatic properties at the initial stage and after fatigue. The evaluation results are shown in Table 5.

[0070]

[Table 7]

Example 15 An electrophotographic photosensitive member of Example 15 was obtained by sequentially stacking an intermediate layer, a charge generation layer and a charge transport layer on an aluminum drum having a diameter of 80 mm and a length of 360 mm in the same manner as in Example 8. Created. However, the thickness of the charge transport layer was 25 μm.

Comparative Example 14 An electrophotographic photosensitive member of Comparative Example 14 was prepared by sequentially stacking an intermediate layer, a charge generation layer and a charge transport layer on an aluminum drum having a diameter of 80 mm and a length of 360 mm in the same manner as in Comparative Example 9. Created. However, the thickness of the charge transport layer was 25 μm.

The electrophotographic photosensitive member obtained as described above was used in Imagio 3
It was set to 20 (manufactured by Ricoh Co., Ltd.), and the initial image and the image quality after copying 50,000 sheets were evaluated. Evaluation is 25 ° C / 50
It was performed under the environment of% RH. Table 8 shows the results.

[0074]

[Table 8]

[0075]

As described above, the electrophotographic photosensitive member of the present invention has good sensitivity to long-wavelength light, excellent durability by repeated use, and further has a recording device using a laser beam as a light source. Even when used for, it has no image defects such as moire and black spots, has high performance and is extremely excellent in practical value.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the layer structure of an electrophotographic photoreceptor of the present invention.

FIG. 2 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

5 is an X-ray diffraction spectrum diagram of the titanyl phthalocyanine pigment obtained in Synthesis Example 1. FIG.

6 is an X-ray diffraction spectrum diagram of the titanyl phthalocyanine pigment obtained in Synthesis Example 2. FIG.

Claims (3)

[Claims] 1. An electrophotographic photosensitive member comprising an electroconductive support and an intermediate layer and a photosensitive layer sequentially laminated thereon, wherein the photosensitive layer is an X-ray using Cu-Kα characteristic X-rays (wavelength 1.54Å).
In the line diffraction spectrum, the main peaks at the Bragg angle 2θ are at least 9.0 ° ± 0.2 ° and 27.2 ° ±.
Containing a titanyl phthalocyanine pigment at 0.2 °,
An electrophotographic photosensitive member characterized in that the intermediate layer contains titanium oxide (P) and a binder resin (R) having a purity of 99.0% by weight or more. 2. An electrophotographic photosensitive member comprising an electroconductive support and an intermediate layer and a photosensitive layer laminated in this order, wherein the photosensitive layer uses Cu-Kα characteristic X-rays (wavelength 1.54Å).
In the line diffraction spectrum, the titanyl phthalocyanine pigment having a main peak of Bragg angle 2θ of only 27.2 ° ± 0.2 ° was contained, and the intermediate layer had a purity of 99.0.
An electrophotographic photoreceptor containing titanium oxide (P) and a binder resin (R) in an amount of at least wt%. 3. Titanium oxide (P) contained in the intermediate layer
And the binder resin (R) have a ratio P / R of 0.8 / 1 by volume.
The electrophotographic photosensitive member according to claim 1 or 2, wherein the electrophotographic photosensitive member is in the range of 3 to 3/1.