JP2009093024A - Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge and image forming apparatus provided with the photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor and an electrophotographic photoreceptor cartridge which have high sensitivity and low residual potential, and to provide an image forming apparatus provided with the photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor which has a photosensitive layer containing a phthalocyanine composition on a conductive support is characterized in that a light absorption spectrum of a layer containing the phthalocyanine composition has the maximum point on secondary differential of an absorbance spectrum between the absorption maximum on the longest wavelength side among absorption maximums existing on a wavelength of 1,000 nm or less and an inflection point which exists on the longer wavelength side than the absorption maximum and exists on the shortest wavelength side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photoreceptor excellent in sensitivity and residual potential, an electrophotographic photoreceptor cartridge, and an image forming apparatus provided with the photoreceptor using a phthalocyanine composition.

Phthalocyanines having photoconductive properties with high sensitivity to long-wavelength light have been extensively studied as excellent photoconductive materials. In particular, it can be suitably used for electrophotographic photoreceptors, electrophotographic plate making materials, photoelectric conversion materials such as image sensors, and is used as a charge generation material for electrophotographic photoreceptors for long-wavelength semiconductor lasers and light-emitting diodes. ing.
Phthalocyanines are known not only to have different physical properties such as light absorption spectrum and photoconductivity depending on the type of the central metal, but also to vary greatly depending on the crystal form. Among phthalocyanines, especially oxytitanium phthalocyanine Has a highly sensitive photoconductive property, and various crystal types are known. Among them, so-called D-type crystalline oxytitanium phthalocyanine having a clear peak at a Bragg angle (2θ ± 0.2 °) of 27.3 ° in the diffraction spectrum for CuKα characteristic X-rays is particularly excellent in sensitivity. Is known (for example, see Patent Document 1).

The thin film X-ray diffraction spectrum of the photosensitive layer containing D-type oxytitanium phthalocyanine by CuKα characteristic X-ray shows at least one strong diffraction at a Bragg angle (2θ ± 0.2 °) of 9.0 ° to 9.8 °. A peak, and at least a strong diffraction peak at 27.3 °, and the peak intensity of the maximum peak between 9.0 ° and 9.8 ° is greater than the peak intensity of 27.3 °, and all of the peaks in the spectrum It is known that the maximum diffraction peak is shown in the diffraction peaks (see, for example, Patent Document 2). It is also known that particularly sensitive D-type oxytitanium phthalocyanine can be produced by selecting an appropriate solvent during the synthesis of oxytitanium phthalocyanine (see, for example, Patent Document 3).
Japanese Patent Laid-Open No. 2-8256 Japanese Patent No. 2888221 JP 2006-131897 A

  Oxytitanium phthalocyanine having various crystal structures is useful as a charge generating material for photoelectric materials, particularly electrophotographic photoreceptors. Among them, the Bragg angle (2θ ± 0. 0 in powder X-ray diffraction spectrum for CuKα characteristic X-rays). (2 °) Oxytitanium phthalocyanine having a crystal structure having a clear diffraction peak at 27.3 ° is called “D-type”, and when used in a photosensitive layer of an electrophotographic photoreceptor, gives a photoreceptor excellent in sensitivity. However, there have been cases where it has not been possible to sufficiently satisfy the demand for improvement in characteristics required of the photoreceptor due to the recent increase in image forming speed.

  An object of the present invention is to provide a highly sensitive and low residual potential electrophotographic photoreceptor using a phthalocyanine composition having suitable performance when applied as a photoelectric material to electronic paper, organic electroluminescent elements, electrophotographic photoreceptors, and the like. Another object is to provide an electrophotographic photosensitive member cartridge and an image forming apparatus including the photosensitive member.

The present inventors have found that when a phthalocyanine composition having a specific ultraviolet-visible light absorption spectrum is used for an electrophotographic photoreceptor, the sensitivity and residual potential are particularly excellent, and the present invention has been completed. .
That is, the first gist of the present invention is an electrophotographic photoreceptor having a photosensitive layer containing a phthalocyanine composition on a conductive support, and the light absorption spectrum of the layer containing the phthalocyanine composition has a wavelength. Of the absorption maximum present at 1000 nm or less, the absorption spectrum between the absorption peak on the longest wavelength side and the inflection point existing on the longer wavelength side than the absorption maximum and on the shortest wavelength side. The electrophotographic photosensitive member is characterized by having a maximum point in the second derivative, and preferably the light absorption spectrum satisfies the following formula (1), and preferably the phthalocyanine composition is an oxy It contains titanium phthalocyanine. Preferably, the phthalocyanine composition has a Bragg angle (2θ in the powder X-ray diffraction spectrum by CuKα characteristic X-ray. ± 0.2 °) contains oxytitanium phthalocyanine having a distinct peak at 27.2 ° or 27.3 °.
Value of second derivative at maximum point / value of second derivative at minimum point <0.3 (1)
Further, the second gist of the present invention includes the electrophotographic photosensitive member of the present invention, a charging unit for charging the electrophotographic photosensitive member, and an exposure unit for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. An electrophotographic photosensitive member cartridge comprising: a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member; and a cleaning unit that cleans the electrophotographic photosensitive member. The third gist of the present invention is that the electrophotographic photosensitive member of the present invention, a charging portion for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. An image forming apparatus comprising: an exposure unit; and a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

  When used in an electrophotographic photoreceptor having a layer having a phthalocyanine composition exhibiting a specific light absorption spectrum in the present invention, the electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, and high-performance image having particularly high sensitivity and low residual potential. A forming apparatus can be provided.

Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of the embodiments of the present invention, and is appropriately modified and implemented without departing from the spirit of the present invention. can do.
The structure of the phthalocyanine composition according to the present invention is not particularly limited as long as the light absorption spectrum in the visible to near-infrared region satisfies the conditions of the present invention.

  Specific examples of the phthalocyanine compound constituting the phthalocyanine composition according to the present invention include metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium and other metals, or oxides thereof. Various crystal forms of coordinated phthalocyanines such as halides, hydroxides and alkoxides are used. In particular, oxytitanium phthalocyanine, vanadyl phthalocyanine, such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), D-type (also known as Y-type), which are highly sensitive crystal types, Chloroindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, μ-oxo-aluminum phthalocyanine dimer such as type II Is preferred.

  Among these phthalocyanine compounds, the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction peak for A-type (β-type), B-type (α-type), and CuKα characteristic X-ray is 27.2 ° or D-type (Y-type) oxytitanium phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, G-type μ-oxo-gallium phthalocyanine dimer, etc. characterized by showing a clear peak at 27.3 ° Particularly preferred. Among them, D-type oxytitanium phthalocyanine having a Bragg angle (2θ ± 0.2 °) of X-ray diffraction spectrum with respect to CuKα characteristic X-ray has peaks at 9.5 °, 24.1 °, and 27.3 °, It is more preferable in terms of excellent compatibility in combination with various charge transport materials.

The phthalocyanine composition in the present invention may be used by mixing or crystallizing the plurality of phthalocyanines. From the viewpoint of sensitivity, it is preferable to use oxytitanium phthalocyanine alone, and more preferable to use only D-type oxytitanium phthalocyanine.
The method for producing D-type oxytitanium phthalocyanine can be roughly divided into two types depending on the method of amorphization. One is a method by mechanical grinding, and the other is a method by chemical treatment.
The D-type oxytitanium phthalocyanine used in the present invention may be produced by any method, but a method by a mechanical grinding process that easily satisfies the requirements of the present invention will be described in detail.

[Method by mechanical grinding]
<Production of oxytitanium phthalocyanine composition>
The oxytitanium phthalocyanine composition according to the present invention, for example, uses phthalonitrile and titanium halide as raw materials, synthesizes dichlorotitanium phthalocyanine, hydrolyzes and purifies the dichlorotitanium phthalocyanine, Manufacture the body. The oxytitanium phthalocyanine composition of the present invention is produced by making the oxytitanium phthalocyanine intermediate amorphous by mechanical grinding and crystallizing the obtained amorphous oxytitanium phthalocyanine in a solvent. be able to. This oxytitanium phthalocyanine composition has a structure represented by the general formula [1]. However, in the case of a reaction using phthalonitrile and titanium tetrachloride, a part of the oxytitanium phthalocyanine composition is chlorinated and a chlorinated compound represented by the general formula [2]. Oxytitanium phthalocyanine is also included.

The content of chlorinated oxytitanium phthalocyanine can be measured by mass spectral intensity ratio. The spectral intensity ratio of chlorinated oxytitanium phthalocyanine to unsubstituted oxytitanium phthalocyanine by mass spectrum can be measured, for example, by the following method.
1. Preparation of samples for measurement;
Oxytitanium phthalocyanine (0.50 g), glass beads (particle size: 1.0 to 1.4 mm) (30 g), and cyclohexanone (10 g) were placed in a 50 mL glass container and shaken with a paint shaker for 3 hours to prepare an oxytitanium phthalocyanine dispersion. 1 μl of this dispersion is collected in a 10 ml sample bottle, 5 ml of chloroform is added, and the mixture is dispersed for 1 hour at room temperature using an ultrasonic oscillator to prepare a 10 ppm dispersion for measurement.

2. Measuring equipment and measuring conditions;
As a mass spectrum measuring apparatus, JMS-700 manufactured by JEOL is used, ionization mode: DCI (−), reaction gas: isobutane (ionization chamber pressure 1 × 10 ⁻⁵ Torr), temperature rising condition: 0 → 0.95A (1 A / min), acceleration voltage: 8.0 KV, mass analysis capability: 2000, scan method: MF-Linear, scan mass range: 500 to 680, full mass range scan time: 0.8 seconds, repeat time: 0. Measurement is performed under measurement conditions of 5 seconds (scanning time 0.05 seconds, waiting time 0.45 seconds).

3. Spectral intensity ratio of chlorinated oxytitanium phthalocyanine;
1 μl of the measurement dispersion was applied to a filament of a DCI probe, and mass spectrum measurement was performed under the above conditions. Ratio of peak areas obtained from ion chromatography of m / Z: 610 corresponding to the molecular ion of chlorinated oxytitanium phthalocyanine and m / Z: 576 corresponding to the molecular ion of unsubstituted oxytitanium phthalocyanine in the obtained mass spectrum ([610] peak area / [576] peak area) is calculated as the spectral intensity ratio.

  The content of chlorinated oxytitanium phthalocyanine is related to crystal form controllability and electrical characteristics, and shows a maximum diffraction peak at 27.2 ° or 27.3 ° in the powder X-ray diffraction spectrum by CuKα characteristic X-ray. In the case of the oxytitanium phthalocyanine composition, the content of the chlorinated oxytitanium phthalocyanine, that is, the mass spectral intensity ratio is preferably 0.007 or more and 0.070 or less. The mass spectral intensity ratio is preferably 0.015 or more, and more preferably 0.020 or more. Similarly, it is preferably 0.060 or less, more preferably 0.055 or less. If the mass spectral intensity ratio is too small, there is a possibility that a crystal form different from the target crystal form of the present invention is mixed in the production of the oxytitanium phthalocyanine composition. In such a case, the oxytitanium phthalocyanine is mixed. When the composition is used for an electrophotographic photoreceptor, the sensitivity may be lowered. Further, if the mass spectral intensity ratio is too large, the crystal type growth of the oxytitanium phthalocyanine composition intermediate proceeds, making it difficult to be amorphous, so that it cannot be made into a suitable crystal type as a photoelectric material. When used for an electrophotographic photoreceptor, a highly sensitive electrophotographic photoreceptor may not be obtained.

  To describe the production of the oxytitanium phthalocyanine composition more specifically, for example, dichlorotitanium phthalocyanine is obtained by a known method such as heating and reacting phthalonitrile and titanium halide in the presence of a high boiling point organic solvent. The high-boiling solvent at this time may be any oxytitanium phthalocyanine composition as long as it has a boiling point higher than the reaction temperature without reacting with the raw materials and products. It is important to select a solvent that can control the content of the chlorinated oxytitanium phthalocyanine contained in the resin, can produce a oxytitanium phthalocyanine composition with a low yield, and a good yield. In order to control the content of chlorinated oxytitanium phthalocyanine, non-halogenated solvents are preferred, and non-halogen compounds such as diphenylmethane, diphenylethane, diphenyl ether, sulfolane, and solvents having a cyclic structure are used. Preferably, a solvent having an aromatic ring such as diphenylmethane, diphenylethane, and diphenyl ether is used. Particularly preferably, a diarylalkane solvent having a structure in which a phenyl group is connected by an alkylidene group, such as diphenylmethane and diphenylethane, is used.

Titanium chloride is preferred as the titanium halide. Examples of the titanium chloride include titanium tetrachloride, titanium trichloride, etc. Since the content of chlorinated oxytitanium phthalocyanine contained in the obtained oxytitanium phthalocyanine composition can be easily controlled, Titanium is preferred.
The reaction temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher. In order to control the content of chlorinated oxytitanium phthalocyanine, more preferably 190 ° C. or higher, usually 300 ° C. or lower, preferably 250 ° C. or lower, more Preferably it is performed at 230 degrees C or less. Usually, titanium chloride is added to a mixture of phthalonitrile and a reaction solvent. The titanium chloride at this time may be added directly as long as it has a boiling point or less, or may be added in combination with the high boiling point solvent. Addition at a high temperature above the boiling point is performed by mixing with the high boiling point solvent. Part of the titanium chloride is preferably added at a temperature of 160 ° C. or less, more preferably 120 ° C. or less, and even more preferably 100 ° C. or less. If the temperature at the time of addition is too high, the content of chlorinated oxytitanium phthalocyanine decreases.

  For example, when producing oxytitanium phthalocyanine using diarylalkane as a reaction solvent and using phthalonitrile and titanium tetrachloride, when titanium tetrachloride is added in portions at a low temperature of 100 ° C. or lower and a high temperature of 180 ° C. or higher, The ratio of the chlorinated oxytitanium phthalocyanine to the unsubstituted oxytitanium phthalocyanine can be controlled by the addition amount ratio.

The temperature raising time for reaching the reaction temperature is preferably 0.5 to 4 hours, more preferably 0.5 to 3 hours, and the reaction duration is preferably 1 to 10 hours, more preferably 2 to 8 hours. Time, more preferably in the range of 2 to 6 hours. This is for controlling the content of chlorinated oxytitanium phthalocyanine in the oxytitanium phthalocyanine composition.
The obtained dichlorotitanium phthalocyanine is subjected to a hydrolytic treatment with alcohols having a boiling point of 100 ° C. or higher such as butanol, pentanol, hexanol, octanol, cyclohexanol, or ketones such as acetophenone, cyclohexanone, hexanedione, and the like. The intermediate is a titanium phthalocyanine composition. In this case, various crystal forms of the oxytitanium phthalocyanine composition intermediate are used. Usually, in the powder X-ray diffraction spectrum by CuKα characteristic X-ray, the Bragg angle (2θ ± 0.2 °) is 7.6 °, This is normally called B-type having strong diffraction peaks at 25.5 ° and 28.6 °. However, since the B-type oxytitanium phthalocyanine often coexists with other crystal types of phthalocyanines, it is repeatedly hydrolyzed until no other crystal type peaks are substantially observed in the powder X-ray diffraction spectrum. Preferably it is done. If other crystals of phthalocyanines remain, it will be a major factor in reducing the sensitivity.

  The obtained oxytitanium phthalocyanine composition intermediate is made amorphous by a mechanical grinding method. Amorphization is generally performed by chemical treatment methods such as the acid paste method and the acid slurry method, but when these are used, a chemical reaction is caused to the phthalocyanine compound or phthalocyanine is used. There is a possibility that the molecule may be broken due to ring cleavage, which may adversely affect the photoconductive properties of the resulting oxytitanium phthalocyanine composition. For mechanical grinding, for example, an apparatus such as a paint shaker, an automatic mortar, a planetary mill, a vibrating ball mill, a CF mill, a roller mill, a sand grind mill, or a kneader can be used, but is not limited thereto. As the grinding media, known grinding media such as glass beads, steel beads, alumina beads, and zirconia beads can be used. In addition to grinding media, at the time of grinding, grinding aids such as sodium chloride and sodium hydroxide that can be easily removed after grinding can be used in combination. Further, the grinding by the above treatment method may be performed by dry grinding or by wet grinding in the presence of a solvent.

  When dry grinding is performed, the fine crystal / amorphous solid is separated from the grinding media after dry grinding, and then the crystallite / amorphous solid can be converted to a desired crystal form by solvent treatment. Any known solvent can be used as the solvent used for the conversion of the crystal form. Examples of known solvents include, for example, saturated aliphatic solvents such as pentane, hexane, octane and nonane, aromatic solvents such as toluene, xylene, methylnaphthalene, diphenylmethane and anisole, chlorobenzene, dichlorobenzene and chloronaphthalene. Halogenated aromatic solvents, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, and benzyl alcohol, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chains such as acetone, cyclohexanone, and methyl ethyl ketone, and Cyclic ketone solvents, ester solvents such as methyl formate, ethyl acetate, n-butyl acetate, halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, diethyl ether, dimethoxyethane, te Non-chains such as lahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, and cyclic ether solvents, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, hexamethylphosphate triamide, etc. Examples include protic polar solvents, n-butylamine, isopropanolamine, diethylamine, triethanolamine, nitrogen-containing compounds such as ethylenediamine, triethylenediamine, and triethylamine, mineral oil such as ligroin, and water. Saturated aliphatic solvents, aromatic solvents, halogenated aromatic solvents, alcohol solvents, chain and cyclic ketone solvents, ester solvents, chain and cyclic ether solvents, aprotic The polar solvent and water are preferred. The above solvents may be used alone or as a mixed solvent of two or more. The treatment temperature can be from the freezing point to the boiling point of the solvent to be used and the mixed solvent, but is usually in the range of 10 ° C. to 200 ° C. from the viewpoint of safety. The amount of the solvent used is preferably 0.1 to 500 parts by weight with respect to 1 part of the phthalocyanine composition, and preferably 1 to 250 parts by weight in consideration of productivity.

  As the wet grinding apparatus, a ball mill, an attritor, a roll mill, a sand mill, a homomixer, or the like can be used, but it is not limited to the above-described means. Any known solvent can be used as the solvent for wet grinding. Examples of known solvents include saturated aliphatic solvents such as pentane, hexane, octane, and nonane, aromatic solvents such as toluene, xylene, methylnaphthalene, diphenylmethane, and anisole, chlorobenzene, dichlorobenzene, chloronaphthalene, and the like. Halogenated aromatic solvents, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and benzyl alcohol, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain structures such as acetone, cyclohexanone and methyl ethyl ketone, and cyclic Ketone solvents, ester solvents such as methyl formate, ethyl acetate, n-butyl acetate, halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, diethyl ether, dimethoxyethane, teto Non-chains such as hydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, and cyclic ether solvents, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, hexamethylphosphate triamide, etc. Examples include protic polar solvents, n-butylamine, isopropanolamine, diethylamine, triethanolamine, nitrogen-containing compounds such as ethylenediamine, triethylenediamine, and triethylamine, mineral oil such as ligroin, and water. Then, saturated aliphatic solvent, aromatic solvent, halogenated aromatic solvent, alcohol solvent, chain and cyclic ketone solvent, ester solvent, chain and cyclic ether solvent, aprotic polarity A solvent and water are preferable. The above solvents may be used alone or as a mixed solvent of two or more. The amount of the solvent used is preferably 1 part by weight or more and 200 parts by weight or less with respect to 1 part of the phthalocyanine composition, and 3 parts by weight or more and 100 parts by weight or less in view of productivity. The treatment temperature can be not lower than the freezing point of the solvent and not higher than the boiling point, but is preferably 10 ° C. or higher and 100 ° C. or lower in view of safety. As the solvent treatment in wet grinding, milling may be performed using a known grinding media such as glass beads, alumina beads, steel beads, zirconia beads and the like, if necessary.

  As the solvent used for the solvent treatment performed after the wet grinding, the same solvent as the solvent that can be used for crystal conversion and crystal control after the dry grinding can be used. As a method of solvent treatment after amorphization, treatment may be performed by dispersing and stirring the obtained amorphous composition in a solvent, or by exposing the amorphous composition to solvent vapor. In addition to the amorphous composition, the solvent treatment can be carried out together with grinding media such as glass beads, steel beads, and alumina beads.

<X-ray diffraction spectrum>
The phthalocyanine composition used in the present invention is preferably an oxytitanium phthalocyanine composition, and further, a powder by CuKα characteristic X-ray, or a Bragg angle (2θ ± 0.2 °) of 27.2 ° in an X-ray diffraction spectrum. Or it is preferable to have a clear peak at 27.3 °.

The powder diffraction spectrum for CuKα characteristic X-rays of the oxytitanium phthalocyanine composition can be measured according to a method usually used for powder X-ray diffraction measurement of a solid. For example, the powder diffraction spectrum can be measured by the following method.
Measuring equipment and conditions:
As a measuring apparatus, PW1700 manufactured by PANalytical, which is a powder X-ray diffractometer of a concentrated optical system using CuKα rays as a radiation source, was used. Measurement conditions are: X-ray output 40 kV, 30 mA, scanning range (2θ) 3-40 °, scanning step width 0.05 °, scanning speed 3.0 ° / min, divergence slit 1.0 °, scattering slit 1.0 °, the light receiving slit is 0.2 mm.

  The thin film X-ray diffraction spectrum by CuKα characteristic X-ray of the photosensitive layer of the electrophotographic photosensitive member using the oxytitanium phthalocyanine composition of the present invention maintains the orientation of the powder state, and the Bragg angle (2θ ± 0.2 ° ) It is particularly preferred when it shows a strong diffraction peak at 27.2 ° or 27.3 °. An electrophotographic photoreceptor using an oxytitanium phthalocyanine composition showing a strong diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° or 27.3 ° is a highly sensitive photoreceptor.

The diffraction spectrum by the CuKα characteristic X-ray of the photosensitive layer may be measured by any method as long as it can obtain the X-ray diffraction spectrum of the photosensitive layer itself. There is a method of forming and measuring on the surface. More specifically, an example of a method for measuring a diffraction spectrum of the photosensitive layer by CuKα characteristic X-ray is shown below.
1. Sample preparation method;
A photosensitive layer forming coating solution is applied to the non-reflective cover glass so as to have a film thickness of 10 μm or more and dried.

2. Measuring equipment and measuring conditions;
As the measuring apparatus, a CuKα ray obtained by paralleling a single color with an artificial multilayer mirror was used as a radiation source and 0). Measurement conditions are: X-ray output 50 kV, 250 mA, fixed incident angle (θ) 1.0 °, scanning range (2θ) 3-40 °, scan step width 0.05 °, incident solar slit 5.0 °, incident slit The diffraction spectrum is measured at 0.1 mm and a light receiving solar slit of 0.1 °.
3. About peak intensity;
The peak intensity represents the height of a peak on the chart of the obtained spectrum.

<Light absorption spectrum>
The light absorption spectrum of the layer containing the phthalocyanine composition in the present invention is the absorption maximum on the longest wavelength side among the absorption maximums existing at a wavelength of 1000 nm or less, and is present on the longer wavelength side than the absorption maximum, and most It has a maximum point in the second derivative of the absorbance spectrum between the inflection point existing on the short wavelength side, and the method for measuring the light absorption spectrum is the light absorption of the layer containing the phthalocyanine composition. There is no limitation on the measurement method as long as it is a method capable of obtaining a spectrum.

  As a measurement sample, a photosensitive layer forming coating solution having a phthalocyanine composition or a photosensitive layer in an electrophotographic photosensitive member can be used. When using a coating solution for forming a photosensitive layer, it is possible to measure the light absorption spectrum with a spectrophotometer directly or after diluting the coating solution to an appropriate concentration. Or the method of measuring the light absorption spectrum of the sample apply | coated to the transparent film, and calculating | requiring a light absorption spectrum from the reflection spectrum of the sample apply | coated to the aluminum vapor deposition sheet | seat is mentioned. When measuring from a photosensitive layer formed on an electrophotographic photoreceptor, the reflection spectrum can be directly measured to determine the absorbance, or the photosensitive layer is eluted with an appropriate solvent, and the eluate of this phthalocyanine composition It is also possible to measure the light absorption spectrum. The following is a measurement method of the light absorption spectrum used in the present invention, but the measurement method is not limited to this.

Sample preparation method;
In the light absorption spectrum of the coating solution for forming a photosensitive layer containing the phthalocyanine composition, the light absorption spectrum is measured by diluting with n-propanol until the absorbance at the peak near 800 nm is 1.0 or more and 1.5 or less. Prepare samples for use.
Measuring equipment and measuring conditions;
Using a Shimadzu UV1650PC, a slit width of 2 nm and a scan speed of medium are set, and a light absorption spectrum of 400 nm to 1000 nm is measured at a sampling pitch of 1 nm.

The absorption maximum on the longest wavelength side (hereinafter referred to as the maximum A) among the absorption maximums existing at a wavelength of 1000 nm or less according to the present invention can be directly obtained from this light absorption spectrum.
The inflection point existing on the longer wavelength side than the local maximum A according to the present invention and on the shortest wavelength side is obtained by using the attached software UVProbe (Ver 1.12) to perform data conversion of data calculation-differentiation-1
Next-delta Lambda 10nm under the condition of differentiation, in the differentiated data corresponds to the minimum wavelength (hereinafter referred to as the inflection point B) that exists on the longer wavelength side than the maximum A and on the shortest wavelength side To do.

In the light absorption spectrum of the layer containing the phthalocyanine composition according to the present invention, a second derivative maximum point of absorbance exists between the maximum A and the inflection point B.
To find the maximum point in the second derivative of the absorbance spectrum, the attached software UVProbe (Ver 1.12) can be used in the same manner. In this software, the maximum value is obtained by performing the differential process twice under the condition of data conversion-differentiation-first order-delta lambda 10 nm for data calculation, and the value of the second derivative (unit: Abs / nm ² ) is calculated. Can do.

In the light absorption spectrum of the layer having a phthalocyanine composition according to a conventionally known technique, there is no maximum in the second derivative between the maximum A and the inflection point B.
In the light absorption spectrum of the layer having the phthalocyanine composition of the present invention, there is a maximum point in the second derivative of absorbance between the maximum A and the inflection point B. In particular, it is preferable that a maximum point and a minimum point exist between the maximum A and the inflection point B in the second derivative of absorbance, and satisfy the following formula.

Value of second derivative at maximum point / value of second derivative at minimum point <0.3
From the viewpoint of increasing sensitivity, more preferably,
Value of second derivative at maximum point / value of second derivative at minimum point <0.2
From the viewpoint of the stability of the coating solution,
Value of second derivative at maximum point / value of second derivative at minimum point <0.15
It is particularly preferred that

  The reason why the electrophotographic photoreceptor satisfying the above conditions is highly sensitive and excellent in the stability of the coating solution is not clear, but it is presumed that one of the reasons is the orientation state of the phthalocyanine composition forming the photosensitive layer. In the light absorption spectrum of the layer having the phthalocyanine composition of the present invention, a maximum exists in the second derivative of absorbance between the maximum A and the inflection point B. This indicates that another absorber exists at a longer wavelength than the absorption A. The smaller the value of the second derivative at the local maximum / secondary derivative at the local minimum, the larger the absorber. It is shown that. The spectrum of phthalocyanine crystals can be understood based on the theory of exciton interaction. That is, absorption is observed at a long wavelength when transition dipole moments of phthalocyanine single molecules are linked in a head-to-tail form. In particular, long-wavelength absorption is strongly observed when the crystal orientation is aligned and the number of consecutive transition dipole moments is large or more linear. The presence of another absorber at a longer wavelength than the absorption A in the present invention indicates that the crystal regularity is improved or the orientation is changed, which is different from the previously known phthalocyanine composition. Yes.

  In particular, when the phthalocyanine composition according to the present invention contains oxytitanium phthalocyanine, the effect of the present invention becomes remarkable, and further, the Bragg angle (2θ ±) of the X-ray diffraction peak with respect to CuKα characteristic X-rays. 0.2 °) contains D-type oxytitanium phthalocyanine having a clear peak at 27.2 ° or 27.3 °, which is advantageous in terms of sensitivity and residual potential.

<Photosensitive layer containing phthalocyanine composition>
The structure of the photosensitive layer according to the present invention may be any conventionally known structure, and the phthalocyanine composition according to the present invention may be contained in any layer as long as it is in the photosensitive layer. The phthalocyanine composition according to the present invention normally functions as a charge generation material, and therefore, it is used for a charge generation layer in the case of a laminated photosensitive layer, and in a single layer in the case of a single layer type photosensitive layer. It is usually used as a charge generating material in the photosensitive layer. Therefore, as the photosensitive layer containing a phthalocyanine composition, in the case of a multilayer photosensitive layer, the charge generation layer preferably contains a phthalocyanine composition, and in the case of a single-layer photosensitive layer, the single-layer photosensitive layer. It is preferred that the layer contains a phthalocyanine composition.

<Charge generation layer>
The charge generation layer in the stacked type will be described below. The phthalocyanine composition in the photosensitive layer having the light absorption spectrum in the present invention has higher head-to-tail regularity in crystal orientation than the conventional phthalocyanine crude product. In order to produce a photoreceptor having a photosensitive layer containing such a highly oriented phthalocyanine composition, the selection of the active substance during the preparation of the coating solution for forming the charge generation layer and the production conditions of the coating solution must be controlled. is important.

  The phthalocyanine used in the phthalocyanine composition according to the present invention is not particularly limited, but preferably contains oxytitanium phthalocyanine from the viewpoint of sensitivity, and the Bragg angle (2θ ± 0.2 in the powder X-ray diffraction spectrum by CuKα characteristic X-rays). °) It is particularly preferable from the viewpoint of sensitivity to use D-type oxytitanium phthalocyanine having a clear peak at 27.2 ° or 27.3 °.

Among these, from the viewpoint of crystal stability, those prepared using the above-described diarylalkane as a reaction solvent are preferable.
The binder resin used for the charge generation layer is not limited, and polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinyl alcohol, and ethyl vinyl ether, polyvinyl acetal resin, Examples include polycarbonate resin, polyamide resin, cellulose ether resin, polyurethane resin, polyester resin, polyester polycarbonate resin, polyarylate resin, phenoxy resin, silicon resin, epoxy resin and the like. As the binder resin, only one kind of these resins may be used, or a mixture of two or more kinds may be used. Among these resins, polyvinyl acetal resin and phenoxy resin are preferable in terms of crystal stabilization.

  Solvents used in the coating solution for forming the charge generation layer include alcohols such as methanol, ethanol and propanol, ethers such as tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxyethane, methyl ethyl ketone, cyclohexanone, 4- Examples include ketones such as methoxy-4-methyl-2-pentanone, hydrocarbons such as toluene and xylene, and chlorinated hydrocarbons such as dichloromethane, chloroform, and 1,2-dichloroethane. Only one of these solvents may be used, or a mixture of two or more may be used. Among these solvents, 1,2-dimethoxyethane and 4-methoxy-4-methyl-2-pentanone are preferable. This is because the crystal stability of the phthalocyanine composition according to the present invention is enhanced. Hydrocarbons such as toluene and xylene are also preferable because the crystals can be kept stable.

The ratio between the charge generating material and the binder resin is not particularly limited, but is generally 5 to 500 parts by weight, preferably 20 to 300 parts by weight, with respect to 100 parts by weight of the charge generating material. The film thickness of the charge generation layer of the multilayer photoreceptor is usually 0.05 μm or more and 5 μm or less, preferably 0.1 μm or more and 2 μm or less.
The coating solution for forming a photosensitive layer can be obtained by a method such as dispersing the phthalocyanine composition together with a binder resin and a solvent by a dispersing machine such as a sand grind mill, a ball mill, an attritor, or an ultrasonic oscillator. Is preferably dispersed using a sand grind mill or an ultrasonic oscillator.

  Dispersion is preferably performed in a short time in order to suppress changes in crystals, and in the case of dispersion by a sand grind mill, preferably 2 hours or less, more preferably 1.5 hours or less, and even more preferably 1 hour. Hereinafter, 30 minutes or less is particularly preferable. Further, if the dispersion time is too short, the crystals are not sufficiently dispersed, and therefore, preferably 10 minutes or more, more preferably 20 minutes or more. In the case of dispersion using an ultrasonic oscillator, it is preferably 1 hour or less, more preferably 45 minutes or less, and even more preferably 30 minutes or less. Further, if the dispersion time is too short, the crystals are not sufficiently dispersed, and therefore, preferably 10 minutes or more, more preferably 20 minutes or more.

The temperature during dispersion is preferably 10 ° C. or less, more preferably 5 ° C. or less, and particularly preferably 3 ° C. or less from the viewpoint of suppressing crystal change. Moreover, since gelation will occur if the temperature is too low, it is preferably −50 ° C. or higher, more preferably −20 ° C. or higher, and −10 ° C. or higher.
<Electrophotographic photoreceptor>
Industrial applicability of the phthalocyanine composition according to the present invention is applicable to electrophotographic photoreceptors. The electrophotographic photoreceptor of the present invention is not limited in its detailed configuration as long as a photosensitive layer containing the phthalocyanine composition according to the present invention is provided on a conductive support. A typical configuration will be described below.

<Conductive support>
As the conductive support used in the present invention, any of those used in known electrophotographic photoreceptors can be used. Specifically, for example, drums, sheets made of metal materials such as aluminum, stainless steel, copper, nickel, etc., laminates or vapor depositions of these metal foils, or aluminum, copper, palladium, tin oxide, indium oxide on the surface, etc. Insulating supports such as polyester film and paper provided with a conductive layer. Furthermore, a plastic film, a plastic drum, paper, a paper tube, and the like obtained by applying a conductive material such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with an appropriate binder to conduct a conductive treatment may be used. Further, a plastic sheet or drum containing a conductive material such as metal powder, carbon black, or carbon fiber and becoming conductive can be used. Examples thereof include a plastic film and a belt subjected to conductive treatment with a conductive metal oxide such as tin oxide and indium oxide.

  Among them, an endless pipe made of metal such as aluminum is a preferable support. An endless pipe made of aluminum or its alloy is formed by processing such as extrusion, drawing, and ironing. What was shape | molded may be used as it is, and what added processes, such as cutting, grinding, and grinding | polishing further, may be used. The surface of the conductive support can be subjected to various treatments such as oxidation treatment and chemical treatment within a range that does not affect the image quality.

<Blocking layer>
A known blocking layer that is usually used may be provided between the conductive substrate and the photosensitive layer. Examples of the blocking layer include an anodized aluminum film, an inorganic layer such as aluminum oxide and aluminum hydroxide, polyvinyl methyl ether, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, and an ethylene-acrylic acid copolymer. Polyethylene, polyester, phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyridine, polyurethane, polyglutamic acid, polyvinyl alcohol, casein, polyvinyl pyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, An organic layer such as polyamide is used. When the organic layer is used as a blocking layer, metal oxides such as titania, alumina, silica, and zirconium oxide, or metal fine powders such as copper, silver, and aluminum may be dispersed.

  The blocking layer has metal oxide fine particles such as alumina, titania and silica, and organic or inorganic dyes or pigment particles capable of absorbing the wavelength of the laser light used, particularly for the purpose of preventing interference fringes in laser exposure. Etc. may be included. Although the thickness of these blocking layers can be set for convenience, it is usually 0.05 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less.

The content ratio of the metal oxide particles, dyes, or pigment particles to the binder resin is not particularly limited, but the blocking layer can be used in the range of 40 to 400 parts by weight with respect to 100 parts by weight of the binder. It is preferable in terms of dispersion stability, storage stability, applicability, and the like when coating.
<Photosensitive layer>
The photosensitive layer of the electrophotographic photosensitive member of the present invention may have a single layer structure (hereinafter sometimes referred to as a single layer type photosensitive member) in which a charge generating substance, a charge transporting substance and a binder resin are contained in a single layer. Alternatively, a stacked structure in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are stacked (hereinafter sometimes referred to as a multilayer photoreceptor) may be used. The photosensitive layer comprises a phthalocyanine composition according to the present invention together with other raw materials such as a charge generating substance, a charge transporting substance, a binder resin, and a solvent, as well as a sand grind mill, a ball mill, an attritor, and an ultrasonic transmitter. It can be formed by applying a coating solution for forming a photosensitive layer obtained by a known dispersion method such as dispersing with a disperser on a conductive support and drying it. In particular, a photosensitive layer is formed by applying the coating solution obtained by treating a solution containing phthalocyanine and a binder resin with a sand grind mill and / or an ultrasonic oscillator on a conductive support and drying it. It is preferable to do this.

-Charge generating materials;
Although the phthalocyanine composition according to the present invention is used as the charge generation material, other known charge generation materials different from the phthalocyanine composition according to the present invention may be used in combination. Examples of the charge generating substance used in combination include various photoconductive materials such as a phthalocyanine pigment, an azo pigment, a quinacridone pigment, an indigo pigment, a perylene pigment, a polycyclic quinone pigment, an anthrone pigment, a benzimidazole pigment, and a squalium pigment.

  Moreover, when using an azo pigment together, various well-known bisazo pigments and trisazo pigments are preferably used. An example of a preferable azo pigment is shown in the following formula (5). In the following formula (5), Cp1 to Cp3 represent couplers.

  In the above formula (5), the following structures are preferable as the couplers Cp1 to Cp3.

However, it is preferable not to use a charge generating material other than the phthalocyanine composition in view of sensitivity.
-Charge transport materials;
Examples of the charge transport material include polymer compounds such as polyvinyl carbazole, polyvinyl pyrene, polyglycidyl carbazole, polyacenaphthylene, or indole derivatives, imidazole derivatives, pyrazole derivatives, pyrazoline derivatives, oxadiazole derivatives, oxazole derivatives, thiadiazole derivatives, etc. Heterocyclic compounds, aniline derivatives, hydrazone derivatives, carbazole derivatives, stilbene derivatives, butadiene derivatives, arylamine derivatives, enamine derivatives, and other low molecular compounds, or those in which a plurality of these are bonded, among these hydrazone derivatives , A carbazole derivative, a stilbene derivative, a butadiene derivative, an arylamine derivative, an enamine derivative, or a combination of these is preferably used. These charge transport materials may be used alone or in combination. Examples of the charge transport material are listed below, but are not limited thereto.

In all structural formulas of the “other charge transport materials” exemplified above, R independently represents a hydrogen atom or a substituent. As the substituent, an alkyl group, an alkoxy group, a phenyl group and the like are preferable. Particularly preferred is a methyl group.
・ Laminated photoreceptors;
The charge generation layer of the multilayer photoreceptor is as described above.

  The charge transport layer of the multilayer photoreceptor can be obtained by coating and drying a coating solution obtained by dissolving the charge transport material and the binder polymer in a solvent. As the binder polymer, a binder polymer that has good compatibility with the charge transport material and does not crystallize or phase-separate after the coating film is formed is preferable. Examples of such binder polymers include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid esters, methacrylic acid esters, vinyl alcohol, ethyl vinyl ether, polyvinyl acetals, polycarbonates, polyesters, Polyarylate, polysulfone, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, phenoxy resin, silicon resin, epoxy resin, and polymer in which the charge transfer material of the low molecular weight compound described above is introduced into the main chain or / and the side chain, etc. Is mentioned. Among these, polycarbonate resins and polyarylate resins are preferably used in view of mechanical properties such as wear resistance and compatibility between the charge transport material in the solution and the binder polymer.

Polycarbonate resins and polyester resins generally have a partial structure of a diol component. Examples of the diol component forming these structures include bisphenol residues and biphenol residues.
Specific examples thereof include bis- (4-hydroxy-3,5-dimethylphenyl) methane, bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-methylphenyl) methane, 1,1- Bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxy-3) -Methylphenyl) propane, 2,2-bis- (4-hydroxyphenyl) butane, 2,2-bis- (4-hydroxyphenyl) pentane, 2,2-bis- (4-hydroxyphenyl) -3-methylbutane 2,2-bis- (4-hydroxyphenyl) hexane, 2,2-bis- (4-hydroxyphenyl) -4-methylpentane, 1,1-bis- ( -Hydroxyphenyl) cyclopentane, 1,1-bis- (4-hydroxyphenyl) cyclohexane, bis- (3-phenyl-4-hydroxyphenyl) methane, 1,1-bis- (3-phenyl-4-hydroxyphenyl) ) Ethane, 1,1-bis- (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxyphenyl) propane, 1,1-bis- (4-hydroxy-) 3-methylphenyl) ethane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-3-ethylphenyl) propane, 2,2-bis- ( 4-hydroxy-3-isopropylphenyl) propane, 2,2-bis- (4-hydroxy-3-sec-butylphenyl) propane, 1, -Bis- (4-hydroxy-3,5-dimethylphenyl) ethane, 2,2-bis- (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3,5) -Dimethylphenyl) cyclohexane, 1,1-bis- (4-hydroxy-3,6-dimethylphenyl) ethane, bis- (4-hydroxy-2,3,5-trimethylphenyl) methane, 1,1-bis- (4-hydroxy-2,3,5-trimethylphenyl) ethane, 2,2-bis- (4-hydroxy-2,3,5-trimethylphenyl) propane, bis- (4-hydroxy-2,3,5) -Trimethylphenyl) phenylmethane, 1,1-bis- (4-hydroxy-2,3,5-trimethylphenyl) phenylethane, 1,1-bis- (4-hydroxy-2,3 , 5-trimethylphenyl) cyclohexane, bis- (4-hydroxyphenyl) phenylmethane, 1,1-bis- (4-hydroxyphenyl) -1-phenylethane, 1,1-bis- (4-hydroxyphenyl)- 1-phenylpropane, bis- (4-hydroxyphenyl) diphenylmethane, bis- (4-hydroxyphenyl) dibenzylmethane, 4,4 ′-[1,4-phenylenebis (1-methylethylidene)] bis- [phenol ], 4,4 '-[1,4-phenylenebismethylene] bis- [phenol], 4,4'-[1,4-phenylenebis (1-methylethylidene)] bis- [2,6-dimethylphenol ], 4,4 '-[1,4-phenylenebismethylene] bis- [2,6-dimethylphenol], 4,4'-[1,4-phenylenebismethylene] bis- [2 , 3,6-trimethylphenol], 4,4 ′-[1,4-phenylenebis (1-methylethylidene)] bis- [2,3,6-trimethylphenol], 4,4 ′-[1, 3-phenylenebis (1-methylethylidene)] bis- [2,3,6-trimethylphenol], 4,4′-dihydroxydiphenyl ether, 4,4-bis (4-hydroxyphenyl) valeric acid stearyl ester, 4, 4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxydiphenyl ether, 3,3', 5,5'-tetramethyl- 4,4′-dihydroxydiphenyl sulfone, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenyl sulfide, phenolphthalein, 4,4 ′ [1,4-phenylenebis (1-methylvinylidene)] bisphenol, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bis [2-methylphenol], (2-hydroxyphenyl) ( 4-hydroxyphenyl) methane, (2-hydroxy-5-methylphenyl) (4-hydroxy-3-methylphenyl) methane, 1,1- (2-hydroxyphenyl) (4-hydroxyphenyl) ethane, 2,2 Bisphenol components such as-(2-hydroxyphenyl) (4-hydroxyphenyl) propane and 1,1- (2-hydroxyphenyl) (4-hydroxyphenyl) propane, 4,4'-biphenol, 2,4'- Biphenol, 3,3′-dimethyl-4,4′-dihydroxy-1,1′-biphenyl, 3,3′-dimethyl-2,4′-dihydride Xi-1,1′-biphenyl, 3,3′-di- (t-butyl) -4,4′-dihydroxy-1,1′-biphenyl, 3,3 ′, 5,5′-tetramethyl-4 , 4′-dihydroxy-1,1′-biphenyl, 3,3 ′, 5,5′-tetra- (t-butyl) -4,4′-dihydroxy-1,1′-biphenyl, 2,2 ′, Examples include biphenol components such as 3,3 ′, 5,5′-hexamethyl-4,4′-dihydroxy-1,1′-biphenyl.

  Especially, the diol component (bisphenol, biphenol, etc.) of the polycarbonate resin which can be used suitably from the surface of manufacture and a photoreceptor characteristic is illustrated below.

  In particular, when a diol component having the following structure is used, high sensitivity is preferable.

  Moreover, it is preferable to use what has the following structures as an acid component which forms a polyester resin.

  Particularly preferred acid components are those having the following structure from the viewpoints of electrical properties and wear resistance.

  As the diol used in the polyester resin, the diol used in the above-described polycarbonate resin can be used. Among these, a polyarylate resin having a diol having the following structure as a repeating unit structure is particularly preferable.

These dicarboxylic acid components and diol components can be used in combination.
If the molecular weight of the binder resin is too low, the mechanical strength is insufficient. Conversely, if the molecular weight is too high, the viscosity of the coating solution for forming the photosensitive layer may be too high, resulting in a decrease in productivity. In the case of polycarbonate resin and polyester resin (including polyarylate resin), the viscosity average molecular weight is preferably 10,000 or more, particularly preferably 20,000 or more. Moreover, 70,000 or less is preferable, Most preferably, it is 50,000 or less. The viscosity average molecular weight is measured by the measuring method described in the examples and is defined thereby.

  The ratio of the binder resin to the charge transporting material is usually 10 parts by weight or more, preferably 20 parts by weight or more, particularly preferably 30 parts by weight because the electrical characteristics deteriorate if the amount of the charge transporting material is too small relative to the binder resin. Used in more than part. Further, if the amount of the charge transport material is too large, the hardness of the charge transport layer decreases, wear during use may increase, or the surface may be damaged and image defects may easily occur. Is 100 parts by weight or less, and particularly preferably 80 parts by weight or less.

The thickness of the charge transport layer is usually 10 μm or more and 50 μm or less, preferably 13 μm or more and 35 μm or less.
An electron-withdrawing compound may be added to the charge transport layer as necessary. Examples of electron-withdrawing compounds include tetracyanoquinodimethane, dicyanoquinomethane, cyano compounds such as aromatic esters having a dicyanoquinovinyl group, nitro compounds such as 2,4,6-trinitrofluorenone, and perylene. Fused polycyclic aromatic compounds, diphenoquinone derivatives, quinones, aldehydes, ketones, esters, acid anhydrides, phthalides, metal complexes of substituted and unsubstituted salicylic acid, metal salts of substituted and unsubstituted salicylic acid, aromatic carvone Examples thereof include metal complexes of acids and metal salts of aromatic carboxylic acids. Preferably, cyano compounds, nitro compounds, condensed polycyclic aromatic compounds, diphenoquinone derivatives, metal complexes of substituted and unsubstituted salicylic acids, metal salts of substituted and unsubstituted salicylic acids, metal complexes of aromatic carboxylic acids, aromatic carboxylic acids A metal salt is preferably used.

The photosensitive layer of the electrophotographic photoreceptor of the present invention comprises a plasticizer and an antioxidant for improving gas resistance properties such as film forming properties, flexibility, coating properties, mechanical strength, slipperiness, ozone and NOx. , UV absorber, inorganic particles, resin particles, wax, silicone oil, leveling agent may be contained.
As the antioxidant, known ones can be arbitrarily used. For example, radical chain reaction inhibitors such as phenol-based antioxidants and amine-based antioxidants; chain reaction initiation inhibitors such as UV absorbers, light stabilizers, metal deactivators, and ozone degradation inhibitors; sulfur-based oxidation Examples thereof include peroxide decomposers such as inhibitors and phosphorus-based antioxidants.

  Among the radical chain reaction inhibitors, examples of the phenolic antioxidant include 3,5-di-t-butyl-4-hydroxytoluene, 2,6-di-t-butylphenol, and 2,6-di- t-butyl-4-ethylphenol, 2,6-di-t-butyl-4-methylphenol, 2,2′-methylenebis (6-t-butyl-4-methylphenol), 4,4′-butylidenebis ( 6-t-butyl-3-methylphenol), 4,4′-thiobis (6-t-butyl-3-methylphenol), 2,2′-butylidenebis (6-t-butyl-4-methylphenol), α-tocopherol, β-tocopherol, 2,2,4-trimethyl-6-hydroxy-7-t-butylchroman, pentaerythrityltetrakis [3- (3,5-di-t-butyl-4- Hydroxyphenyl) propionate], 2,2′-thioethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], butylhydroxyanisole, dibutylhydroxyanisole, 1- [2-{(3,5-di-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4 -[3- (3,5-di-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperazyl, 2,4-bis- (n-octylthio) -6- ( 4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, 1,3,5-trimethyl-2,4,6-tris (3 5-di-t-butyl-4-hydroxybenzyl) benzene, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5 -Chlorobenzotriazole, 1- [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- {3- (3,5-di-t-butyl) -4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, etc. Can do.

  Among these, those having one or more t-butyl groups on the phenol ring in the molecule are preferable, and among them, those in which the t-butyl group is bonded to the position adjacent to the phenolic hydroxyl group are more preferable. Specific examples thereof include 3,5-di-t-butyl-4-hydroxytoluene, 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,6 Monophenolic antioxidants such as di-t-butyl-4-methylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, 2,2 '-Methylenebis (6-t-butyl-4-methylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, penta A polyphenol antioxidant such as erythrityltetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] is suitable.

  In addition, as the radical chain reaction inhibitor, for example, hydroquinones can be used. Specific examples thereof include 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like can be mentioned. Examples of amine-based antioxidants include phenyl-β-naphthylamine, α-naphthylamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine, and tribenzylamine.

Among these, 3,5-di-t-butyl-4-hydroxytoluene, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, 1,3, 5-Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene is particularly preferred in terms of electrical properties.
・ Single layer type photoreceptors;
In the case of a single layer type photoreceptor, a known one in which a photosensitive material is dispersed in a binder is used. For example, a material in which a charge generating material is dispersed as a main component in a binder resin, or a material in which a charge generating material and a charge transporting material are dispersed as main components in a binder resin is used. In these cases, as the charge generation material, the charge transport material, and the binder resin, known materials that can be used in the laminated photosensitive layer can be used, and among them, a polycarbonate resin, a polyester resin, a polyester polycarbonate resin, and a polyarylate resin are preferably used. It is done. Moreover, the solvent which can be used for charge transport layer formation of a laminated type photosensitive layer can be used suitably for the solvent of the coating liquid for photosensitive layer formation similarly.

  For example, in the case where a charge generating material and a charge transporting material are the main components and dispersed in a binder resin, the charge generating material is dispersed in a charge transporting medium having a blending ratio such as a charge transporting layer of a multilayer photoreceptor. Is done. In this case, the particle size of the charge generating material needs to be sufficiently small, and is preferably 1 μm or less, more preferably 0.5 μm or less. When the amount of the charge generating material dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained. On the other hand, when the amount is too large, there are problems such as a decrease in chargeability and a decrease in sensitivity. It is used in the range of wt% or more, preferably 1 wt% or more, and usually 50 wt% or less, preferably 20 wt% or less. The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.

The photosensitive layer of the electrophotographic photoreceptor of the present invention comprises a plasticizer and an antioxidant for improving gas resistance properties such as film forming properties, flexibility, coating properties, mechanical strength, slipperiness, ozone and NOx. , UV absorber, inorganic particles, resin particles, wax, silicone oil, leveling agent may be contained.
<Other functional layers>
An overcoat layer may be used on the photosensitive layer in order to improve mechanical properties and gas resistant properties such as ozone and NOx. Furthermore, you may have an adhesive layer, an intermediate | middle layer, a transparent insulating layer, etc. as needed. Furthermore, an intermediate layer may be further provided between the blocking layer and the photosensitive layer.

<Layer formation method>
The blocking layer and the photosensitive layer are formed by applying a coating solution on a conductive support by a spray method, a spiral method, a ring method, a dipping method or the like.
Examples of the spray used in the spray method include air spray, airless spray, electrostatic air spray, electrostatic airless spray, rotary atomizing electrostatic spray, hot spray, and hot airless spray. In order to make the film thickness uniform, a method using a rotary atomizing electrostatic spray described in Republished Hei 1-805198 is preferable.

Examples of the spiral method include a method using an injection coating machine or a curtain coating machine described in Japanese Patent Application Laid-Open No. 52-119651, and a method in which a paint is drawn from a minute opening described in Japanese Patent Application Laid-Open No. 1-2231966. And a method using a multi-nozzle body disclosed in JP-A-3-193161.
The immersion method will be described below. Using an organic conductive compound, a binder, a solvent and the like, a suitable total solid content concentration is 1% or more, more preferably 40% or less, and a viscosity is usually 1 mPa · s to 700 mPa · s, preferably 1 mPa · s. A photosensitive layer coating solution of s to 500 mPa · s is prepared. Here, the viscosity of the coating solution is substantially determined by the type and molecular weight of the binder polymer, but if the molecular weight is too low, the mechanical strength of the polymer itself is lowered, so that the binder polymer has a molecular weight that does not impair this. Is preferably used. A photosensitive layer is formed by a dip coating method using the coating solution thus prepared. Thereafter, the coating film is dried, and the drying temperature time may be adjusted so that necessary and sufficient drying is performed. The drying temperature is usually 100 to 250 ° C, preferably 110 to 170 ° C, more preferably 115 to 140 ° C. As a drying method, a hot air dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like can be used.

<Image forming apparatus>
The electrophotographic photosensitive member obtained as described above has high sensitivity, low residual potential, high chargeability, and small fluctuation due to repetition. In particular, the oxidizing gas generated in the image forming apparatus and the outside during maintenance. It can be used as a photoreceptor having high performance and high durability with little deterioration in image quality due to light. An embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (image forming apparatus of the present invention) will be described below with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6, and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose alternating current on direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, if the exposure is performed using monochromatic light having a wavelength of 780 nm, monochromatic light having a wavelength of 600 nm to 700 nm, slightly short wavelength, or monochromatic light having a wavelength of 380 nm to 500 nm. Good.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.
The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

Here, an example of a contact method is shown, but there is also a non-contact method, and jumping development is mentioned.
The regulating member 45 is formed of a resin blade such as silicone resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  The type of the toner T is arbitrary, and chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used in addition to powdered toner. In the case of chemical toners, those having a small particle size of about 4 to 8 μm are preferable, and the toner particles have various shapes from a nearly spherical shape to a potato shape outside the spherical shape. Can be used. In particular, the polymerized toner is excellent in charging uniformity and transferability, and is suitably used for high image quality.

The toner used in the present invention is particularly preferably a toner by an emulsion polymerization aggregation method, and preferable physical property values are measured by the method disclosed in Japanese Patent Application Laid-Open No. 2007-213050, and the average circularity is preferably 0.940 or more and 1.000 or less, and the volume average The value (Dv / Dn) obtained by dividing the particle diameter (Dv) by the number average particle diameter (Dn) is preferably 1.0 or more and 1.20 or less. For example, the developing toner A shown in the production example of the above publication is suitably used. be able to.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is. A method of transferring to paper after passing through one end, a transfer belt or the like is called an intermediate transfer method.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. If there is little or almost no residual toner, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (pressure roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, and a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

  When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P. The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

In the image forming apparatus configured as described above, an image is recorded according to the following method (the image forming method of the present invention). That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed with a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6. After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.

In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In many cases, the light used in the static elimination process is light having an exposure energy that is at least three times that of exposure.

Further, the image forming apparatus may be further modified and configured, for example, a configuration capable of performing processes such as a pre-exposure process and an auxiliary charging process, a structure performing offset printing, and a plurality of types. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is used alone or in combination with one or more elements of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7. And an integrated cartridge (this is appropriately referred to as an “electrophotographic photosensitive member cartridge”), and the electrophotographic photosensitive member cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a laser beam printer. Also good. In this case, a cartridge case configured to be detachable from the image forming apparatus is used, and the electrophotographic photosensitive member 1 is housed and supported on the cartridge case alone or in combination with the above-described elements, thereby allowing the electrophotographic photosensitive member cartridge to be supported. It can be. With this configuration, for example, when the electrophotographic photosensitive member 1 and other members deteriorate, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
<Production Example 1>
Under a nitrogen atmosphere, 66.6 g of phthalonitrile was suspended in 353 ml of diphenylmethane, and a mixed solution of 15.0 g of titanium tetrachloride and 25 ml of diphenylmethane was added at 40 ° C. After raising the temperature to 205-210 ° C. over about 1 hour, a mixed solution of 10.0 g of titanium tetrachloride and 16 ml of diphenylmethane was added dropwise and reacted at 205-210 ° C. for 5 hours. The product was filtered hot at 130 to 140 ° C., and then washed successively with N-methylpyrrolidone (hereinafter sometimes referred to as NMP) and n-butanol. Next, after heating and refluxing in 600 ml of n-butanol, NMP, water, and methanol were washed and dried to obtain 47.0 g of B-type oxytitanium phthalocyanine. The B-type oxytitanium phthalocyanine (20.0 g) is shaken with 120 ml of glass beads (φ1.0 mm to φ1.4 mm) in a paint shaker for 25 hours, and the oxytitanium phthalocyanine is washed out with methanol and filtered to form amorphous oxytitanium phthalocyanine. Got. After suspending this oxytitanium phthalocyanine in 210 ml of water, further adding 40 ml of toluene, stirring at 60 ° C. for 1 hour, discarding the water by decantation, washing with methanol, filtering and drying crystals 19.0 g of the target oxytitanium phthalocyanine composition was obtained by the conversion operation.

  The powder X-ray diffraction spectrum by CuKα characteristic X-ray of the obtained oxytitanium phthalocyanine composition is shown in FIG. In this X-ray diffraction spectrum, a maximum diffraction peak was observed at a Bragg angle (2θ ± 0.2 °) of 27.3 °. The intensity ratio of the peak of m / z: 610 chlorinated oxytitanium phthalocyanine to the peak intensity of unsubstituted oxytitanium phthalocyanine of m / Z: 576 by mass spectrum was 0.026 to 0.029. Range.

<Production Example 2>
In accordance with the description in “Production Example of Crude TiOPc” and “Example 1” of JP-A-10-7925, β-type oxytitanium phthalocyanine is produced, and the chlorine content contained in the obtained oxytitanium phthalocyanine is changed to elemental content. As a result of analysis using an analysis method, the chlorine content was 0.20% by weight or less below the lower limit of detection.

Moreover, when the peak intensity ratio of oxytitanium phthalocyanine and chlorooxytitanium phthalocyanine was measured according to <Mass Spectrum Measurement Method> described in JP-A No. 2001-115054, it was 0.002%.
50 parts by weight of the obtained β-type oxytitanium phthalocyanine crystal was added to 1250 parts by weight of 95% concentrated sulfuric acid cooled to −10 ° C. or lower. At this time, it added slowly so that the internal temperature of a sulfuric acid solution might not exceed -5 degreeC. After completion of the addition, the concentrated sulfuric acid solution was stirred at −5 ° C. or lower for 2 hours. After stirring, the concentrated sulfuric acid solution was filtered through a glass filter, the insoluble matter was filtered off, and then the concentrated sulfuric acid solution was released into 12500 parts by weight of ice water to precipitate oxytitanium phthalocyanine, followed by stirring for 1 hour. After stirring, the solution was filtered off, and the resulting wet cake was washed again in 2500 parts by weight of water for 1 hour and filtered. By repeating this washing operation until the ionic conductivity of the filtrate reached 0.5 mS / m, 452 parts by weight of a low crystalline oxytitanium phthalocyanine wet cake was obtained (oxytitanium phthalocyanine content 9.5% by weight). .
33 parts by weight of the obtained low crystalline oxytitanium phthalocyanine wet cake was added to 90 parts by weight of water and stirred at room temperature for 30 minutes. Thereafter, 13 parts by weight of 3-chlorobenzaldehyde was added, and the mixture was further stirred at room temperature for 1 hour. After stirring, water was separated, 80 parts by weight of methanol was added, and the mixture was stirred and washed at room temperature for 1 hour. After washing, the mixture is filtered, and 80 parts by weight of methanol is added again, followed by stirring and washing for 1 hour, followed by filtration and drying by heating in a vacuum dryer to obtain CuKα characteristic X-rays (wavelength 1.541Å) shown in FIG. As a result, 2.5 parts by weight of oxytitanium phthalocyanine having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to was obtained.

<Production Example 3>
Under a nitrogen atmosphere, 66.6 g of phthalonitrile was dissolved in 436 ml of 1-chloronaphthalene, and a mixed solution of 25.0 g of titanium tetrachloride and 21 ml of 1-chloronaphthalene was added dropwise at 200 ° C. After reacting at 205-210 ° C for 5 hours, the product was filtered hot at 130-140 ° C. Subsequently, after heating and refluxing in 580 ml of n-butanol, water, NMP and methanol were washed with water and dried to obtain 48.7 g of B-type oxytitanium phthalocyanine. The B-type oxytitanium phthalocyanine (30.0 g) is shaken with 200 ml of glass beads (φ1.0 mm to φ1.4 mm) in a paint shaker for 20 hours, and the oxytitanium phthalocyanine is washed out with methanol and filtered to form amorphous oxytitanium phthalocyanine. Got. Suspend this in 625 ml of water, add 48 ml of orthodichlorobenzene, stir at room temperature for 1 hour, discard the water by decantation, wash with methanol, filter and dry. As a result, 29.0 g of the target oxytitanium phthalocyanine composition was obtained. FIG. 4 shows a powder X-ray diffraction spectrum by CuKα characteristic X-ray of the oxytitanium phthalocyanine composition measured by the same method as in Production Example 1. In this X-ray diffraction spectrum, a maximum diffraction peak was observed at a Bragg angle (2θ ± 0.2 °) of 27.3 °. The intensity ratio of the peak of m / z: 610 chlorinated oxytitanium phthalocyanine to the peak intensity of unsubstituted oxytitanium phthalocyanine of m / Z: 576 by mass spectrum was measured 0.055 to 0.057. Range.

<Example 1>
Using a conductive support in which an aluminum vapor deposition layer (thickness 70 nm) is formed on the surface of a biaxially stretched polyethylene terephthalate resin film (thickness 75 μm), the following undercoat layer dispersion is formed on the aluminum vapor deposition layer of the support. The liquid was applied with a bar coater so that the film thickness after drying was 1.25 μm and dried to form an undercoat layer.

  The undercoat layer dispersion was produced as follows. That is, rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were mixed at high speed. The surface-treated titanium oxide obtained by charging into a kneading machine (“SMG300” manufactured by Kawata Corporation) and mixing at high speed at a rotational peripheral speed of 34.5 m / sec is dispersed by a ball mill in a mixed solvent of methanol / 1-propanol. Thus, a dispersion slurry of hydrophobized titanium oxide was obtained, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis ( 4-amino-3-methylcyclohexyl) methane [compound represented by the following formula (B)] / hexamethylenediamine [following formula The compound molar ratio of the compound represented by C) / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [compound represented by the following formula (E)] is 60%. / 15% / 5% / 15% / 5%) and the polyamide pellets are heated and stirred and mixed to dissolve the polyamide pellets. A dispersion for an undercoat layer containing a solid oxide concentration of 18.0% containing titanium oxide / copolymerized polyamide at a weight ratio of 3/1 was obtained.

  As a charge generation material, 20 parts by weight of the oxytitanium phthalocyanine composition produced in Production Example 1 and 280 parts by weight of 1,2-dimethoxyethane are mixed, and a sand grind mill is used for 1 hour at a temperature range of 0 to 5 ° C. A dispersion was prepared by dispersing. Subsequently, this dispersion, 10 parts by weight of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denka Butyral” # 6000C), 487 parts by weight of 1,2-dimethoxyethane, 85 parts by weight of 4- A coating solution for forming a charge generation layer was prepared by mixing methoxy-4-methyl-2-pentanone.

The charge generation layer forming coating solution was diluted with n-propanol so as to have an absorbance of 1.2, thereby preparing samples for measuring visible and near infrared light absorption spectra.
For the measurement of visible and near-infrared light absorption spectra, UV1650PC made by Shimadzu was used, the slit width was set to 2 nm, the scan speed was set to medium speed, and the light absorption spectra from 400 nm to 1000 nm were measured at a sampling pitch of 1 nm. Further, Table 1 shows the value of the second derivative at the maximum point / the value of the second derivative at the minimum point.

Further, the viscosity immediately after the preparation of the coating solution for forming the charge generation layer and after one month had been examined. The results are shown in Table 1.
Next, the charge generation layer coating solution was applied on the undercoat layer with a bar coater so that the film thickness after drying was 0.4 μm, and dried to form a charge generation layer.
Next, a resin 1 (viscosity average molecular weight) comprising 50 parts by weight of a composition described in JP-A No. 2002-080432 having a structure mainly represented by the following formula CTM1 as a charge transport material and a repeating structure represented by the following formula PCR1. , 40,000) 100 parts by weight, 8 parts by weight of an antioxidant represented by the following formula AOX1, and 0.05 parts by weight of silicone oil as a leveling agent, 640 parts by weight of a tetrahydrofuran / toluene (weight ratio 8/2) mixed solvent To obtain a coating solution for forming a charge transport layer. This charge transport layer forming coating solution is applied onto the charge generation layer prepared previously so that the film thickness after drying is 25 μm, and dried at 125 ° C. for 20 minutes to provide a charge transport layer to provide an electron. A photographic photoreceptor was prepared. This photoreceptor is referred to as a photoreceptor 1.

<Example 2>
20 parts by weight of the oxytitanium phthalocyanine composition obtained in Production Example 1 and 280 parts by weight of 1,2-dimethoxyethane are mixed, and an ultrasonic oscillator (SH1216-40-18 manufactured by BRANSON Co., Ltd., operating frequency 40 kHz, ultrasonic output) 750 W), and a dispersion was produced by dispersion treatment in a temperature range of 0 to 5 ° C. for 45 minutes. The dispersion, 10 parts by weight of polyvinyl butyral (trade name “Denka Butyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.), 253 parts by weight of 1,2-dimethoxyethane, 85 parts by weight of 4-methoxy-4- Methyl-2-pentanone was mixed and further diluted with 527 parts by weight of 1,2-dimethoxyethane, and the obtained liquid was dispersed with an ultrasonic oscillator for 1 hour to prepare a coating solution for forming a charge generation layer.

Using this charge generating layer forming coating solution, the visible and near infrared light absorption spectra and viscosity were measured in the same manner as in Example 1. The results are shown in Table 1 as in Example 1. Further, a photoreceptor 2 was produced in the same manner as in Example 1 by using the charge generation layer forming coating solution.
<Example 3>
A charge generation layer coating solution was prepared in the same manner as in Example 1 except that 20 parts by weight of the oxytitanium phthalocyanine composition produced in Production Example 2 was used as the charge generation material. Using this charge generating layer forming coating solution, the visible and near infrared light absorption spectra and viscosity were measured in the same manner as in Example 1. The results are shown in Table 1 as in Example 1. Also, the same operation as in Example 1 was performed using the coating solution for forming a charge generation layer, whereby a photoreceptor 3 was produced.

<Comparative Example 1>
The same procedure as in Example 1 was conducted except that the charge generation material dispersion temperature was changed from 0 to 10 ° and the dispersion time was changed from 1 hour to 2 hours when the coating liquid for forming the charge generation layer of Example 1 was prepared. A coating solution for forming a charge generation layer was prepared. Using this charge generating layer forming coating solution, the visible and near infrared light absorption spectra and viscosity were measured in the same manner as in Example 1. The results are shown in Table 1 as in Example 1. Further, the same operation as in Example 1 was carried out using the coating solution for forming a charge generation layer to produce a comparative photoreceptor 1.

<Comparative example 2>
When preparing the coating liquid for forming the charge generation layer of Example 2, the temperature of the first ultrasonic dispersion was set to 25 ° C., and the dispersion liquid was prepared by performing a dispersion treatment for 1 hour. A coating solution for forming a charge generation layer was prepared. Using this charge generating layer forming coating solution, the visible and near infrared light absorption spectra and viscosity were measured in the same manner as in Example 1. The results are shown in Table 1 as in Example 1. Further, the same operation as in Example 1 was performed using the coating solution for forming a charge generation layer, and a comparative photoreceptor 2 was produced.

<Comparative Example 3>
A charge generation layer coating solution was prepared in the same manner as in Example 1 except that 20 parts by weight of the oxytitanium phthalocyanine composition produced in Production Example 3 was used as the charge generation material. Using this charge generation layer coating solution, the visible and near-infrared light absorption spectra and viscosity were measured in the same manner as in Example 1. The results are shown in Table 1 as in Example 1. In addition, the same operation as in Example 1 was performed using the charge generation layer coating solution, and a comparative photoreceptor 3 was produced.

<Light absorption spectrum and viscosity of charge generation layer forming coating solution>
The light absorption spectra and viscosity results of the coating solutions for forming the charge generation layer of Examples 1 to 3 and Comparative Examples 1 and 2 are summarized in Table 1 below.

The value of the second derivative at the maximum point / the value of the second derivative at the minimum point (1)
<Evaluation of electrical characteristics of photoconductor>
About the photoconductors produced in Examples 1 to 3 and Comparative Examples 1 to 3, an electrophotographic characteristic evaluation apparatus produced in accordance with an electrophotographic society measurement standard (secondary electrophotographic technology basics and applications, edited by electrophotographic society, Corona) , Pages 404 to 405), and electrical characteristics were evaluated by a cycle of charging, exposure, potential measurement, and static elimination.

The surface potential of the photoconductor was charged so that the initial surface potential was −700 V under a temperature of 25 ° C. and a relative humidity of 50%, and the halogen lamp light was irradiated with monochromatic light of 780 nm using an interference filter. Irradiation energy (μJ / cm ² ) when the voltage becomes −350 V was defined as sensitivity. In addition, the surface potential when the LED light of 660 nm was irradiated to the static elimination light with the intensity of about 8 μJ / cm ² was defined as the residual potential (−V), and this was measured. The results are shown in Table 2.

The values of the formula (1) obtained from the second derivative of the absorbance of the coating liquid for forming the charge generation layer of Examples 1 to 3 were all 0.3 or less. On the other hand, in Comparative Examples 1 and 2, it is 0.3 or more. In this case, it is suggested that the absorption existing on the long wavelength side of the absorption of A is very small. There was no local maximum.

As shown in Table 2, a photoreceptor produced using a charge transport layer forming coating solution produced using the phthalocyanine composition according to the present invention having a value of formula (1) of 0.3 or less. In Examples 1 to 3, good results were obtained in both sensitivity and residual potential as compared with Comparative Examples 1 and 2.
Hereinafter, the electrophotographic photoreceptor and the image forming apparatus of the present invention were evaluated by performing an image formation test and a stability / durability test of the photoreceptor.

<Example 4>
A coating solution for forming a charge generation layer and a charge transport layer prepared in the same manner as in Example 1 is applied sequentially by dip coating on an aluminum tube having a diameter of 30 mm and a length of 254 mm that has been anodized and sealed. Then, an electrophotographic photosensitive drum having a film thickness of 0.3 μm and a charge transport layer of 25 μm was prepared. This drum is mounted on a Hewlett Packard laser printer, Laser Jet 4 (LJ4), and an image test is performed under conditions of a temperature of 35 ° C. and a relative humidity of 80% (hereinafter sometimes referred to as H / H environment). It was. Next, 10,000 sheets were continuously printed. It was examined whether image defects due to ghost, fog, and leak occurred. The results are shown in Table 3.

<Example 5>
In the coating solution for forming a charge transport layer of Example 1, resin 2 (viscosity average molecular weight, 39, 100) having a repeating structure represented by the following formula PCR2 was used instead of resin 1 as in Example 1. Thus, a charge transport layer forming coating solution 1 was produced. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that this charge transport layer forming coating solution 1 was used, and image evaluation was performed. The results are shown in Table 3.

<Example 6>
In the coating liquid for forming a charge transport layer of Example 1, resin 3 (viscosity average molecular weight, 40, 100) having a repeating structure represented by the following formula PAR1 was used in place of resin 1 as in Example 1. Thus, a charge transport layer forming coating solution 2 was prepared. An electrophotographic photoreceptor was prepared in the same manner as in Example 4 except that this charge transport layer forming coating solution 2 was used, and image evaluation was performed. The results are shown in Table 3.

<Example 7>
In the coating liquid for forming a charge transport layer of Example 1, the same as Example 1 except that Resin 4 (viscosity average molecular weight, 40, 200) having a repeating structure represented by the following formula PAR2 was used instead of Resin 1 Thus, a charge transport layer forming coating solution 3 was produced. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that this charge transport layer forming coating solution 3 was used, and image evaluation was performed. The results are shown in Table 3.

<Comparative example 4>
An electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that the charge generation layer forming coating solution prepared in Comparative Example 1 was used instead of the charge generation layer forming coating solution used in Example 4. Image evaluation was performed. The results are shown in Table 3.
<Comparative Example 5>
An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the charge generation layer forming coating solution prepared in Comparative Example 3 was used instead of the charge generation layer forming coating solution used in Example 4. Image evaluation was performed. The results are shown in Table 3.

<Comparative Example 6>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 5, except that the charge transport layer forming coating solution 1 prepared in Example 5 was used instead of the charge transport layer forming coating solution used in Comparative Example 5. Then, image evaluation was performed. The results are shown in Table 3.
<Comparative Example 7>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 5 except that the charge transport layer forming coating solution 2 prepared in Example 6 was used instead of the charge transport layer forming coating solution used in Comparative Example 5. Then, image evaluation was performed. The results are shown in Table 3.

<Comparative Example 8>
An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 5 except that the charge transport layer forming coating solution 3 prepared in Example 7 was used instead of the charge transport layer forming coating solution used in Comparative Example 5. Then, image evaluation was performed. The results are shown in Table 3.

When the electrophotographic photosensitive member of the present invention was used, good images could be obtained at the initial stage and after repeated images were printed. In particular,
In Examples 5, 6, and 7, the film loss was less than that in Example 4 (80%, 80%, and 60%, respectively), and good images without ghosting and fogging were obtained. It has been found to be particularly preferable when a resin is used.

  It can be applied to electrophotographic apparatuses such as printers, facsimiles, and copiers, and can provide a high-sensitivity electrophotographic photosensitive member with high sensitivity and low residual potential.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 2 is a powder X-ray diffraction spectrum of a D-type oxytitanium phthalocyanine composition obtained in Production Example 1. FIG. 3 is a powder X-ray diffraction spectrum of a D-type oxytitanium phthalocyanine composition obtained in Production Example 2. FIG. 3 is a powder X-ray diffraction spectrum of a D-type oxytitanium phthalocyanine composition obtained in Comparative Production Example 1. FIG.

Explanation of symbols

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
5 Transfer device
6 Cleaning device (cleaning part)
7 Fixing device
41 Developer tank
42 Agitator
43 Supply roller
44 Developing roller
45 Restriction member
71 Upper fixing member (pressure roller)
72 Lower fixing member (fixing roller)
73 Heating device
T Toner
P Recording paper (paper, medium)

Claims (6)

  An electrophotographic photosensitive member having a photosensitive layer containing a phthalocyanine composition on a conductive support, wherein the light absorption spectrum of the layer containing the phthalocyanine composition is the most among the absorption maxima existing at a wavelength of 1000 nm or less. It has a maximum point in the second derivative of the absorbance spectrum between the absorption maximum on the long wavelength side and the inflection point existing on the longer wavelength side than the absorption maximum and on the shortest wavelength side. An electrophotographic photoreceptor. 2. The electrophotographic photoreceptor according to claim 1, wherein a light absorption spectrum of the layer containing the phthalocyanine composition is a spectrum satisfying the following formula (1).
Value of second derivative at maximum point / value of second derivative at minimum point <0.3 (1)   The electrophotographic photosensitive member according to claim 1, wherein the phthalocyanine composition contains oxytitanium phthalocyanine.   The phthalocyanine composition contains oxytitanium phthalocyanine having a clear peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° or 27.3 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray. The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the electrophotographic photosensitive member is characterized by the following.   The electrophotographic photosensitive member according to any one of claims 1 to 4, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, An electrophotographic photosensitive member cartridge comprising: a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member; and at least one of a cleaning unit that cleans the electrophotographic photosensitive member.   The electrophotographic photosensitive member according to any one of claims 1 to 4, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, And an image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member.