JP2000242016A - Electrophotographic photoreceptor and image forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high sensitivity to light of a long wavelength and forming an image at a high forming rate under easy control of forming action at a low production cost, and to provide an image forming method using the photoreceptor. SOLUTION: The photoreceptor 1 has an undercoat layer 3 and a photoconductive layer 4 on the electrically conductive substrate 2. The undercoat layer 3 contains surface-treated titanium dioxide and a bonding resin, the surface treatment is alumina, silica or aluminum laurate treatment and the weight ratio of the titanium dioxide to the bonding resin is 5.0-30.0, or the undercoat layer 3 contains surface-untreated titanium dioxide and the bonding resin and the weight ratio of the titanium dioxide to the bonding resin is 3.0-30.0, or the undercoat layer 3 contains optionally surface-treated zinc oxide and a bonding resin, the surface treatment is alumina or silica treatment and the weight ratio of the zinc oxide to the bonding resin is 1.5-30.0. The photoconductive layer 4 contains oxo-titanyl phthalocyanine, τ- or X-form metal- free phthalocyanine having a specified X-ray diffraction spectrum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member in which an undercoat layer and a photosensitive layer are formed on a conductive support in this order, and an image forming method using the same.

[0002]

2. Description of the Related Art An electrophotographic photoreceptor (hereinafter, also simply referred to as a "photoreceptor") mounted on a copying machine or the like has a photosensitive layer having a photoconductive function on a conductive support. The photoreceptor has a single layer type in which a single substance performs the charge generation function and the charge transport function, which are the photoconductive functions of the photosensitive layer, and a multilayer type in which individual substances are shared. It is roughly divided into a function separation type such as a distributed type. Further, as a photoconductive material constituting the photosensitive layer, an inorganic material such as selenium, cadmium sulfide, and zinc oxide and an organic material such as polyvinyl carbazole have been known.

In recent years, digitization of data processing has been rapidly progressing not only in printers using lasers or LEDs (light emitting diodes) but also in the field of copying machines in order to realize storage and editing of image data. Along with such digitization, the photoreceptor is required to have high sensitivity to light having a relatively long wavelength of 780 nm or 660 nm, and therefore, a phthalocyanine compound is contained in the photosensitive layer.
For example, Japanese Patent Publication No. 5-55860, JP-A-59-1558
51, JP-A-2-23369 and JP-A-61-28
557 discloses an example using oxotitanium phthalocyanine, β-type indium phthalocyanine, X-type metal-free phthalocyanine and vanadyloxyphthalocyanine.

However, when the phthalocyanine compound is contained, image formation is performed from the second time when the charging potential is stabilized because the charging potential of the photoreceptor is low for the first time, and the image forming time is prolonged. Along with the above-described digitization of data transfer and high-speed image processing, there is a strong demand for a reduction in image forming time. For example, Japanese Patent Application Laid-Open No. 8-36301 discloses a method in which an image is formed without discharging a photoconductor at the first time. Japanese Patent Application Laid-Open No. Hei 8-8 / 1991 discloses an example in which a special image forming process for forming an image by removing electricity in the second and subsequent times is adopted.
328284 discloses an example in which an undercoat layer containing an azo pigment is provided between a support and a photosensitive layer.
JP-127711 discloses an example in which the photosensitive layer contains an azo pigment and phthalocyanine.

[0005]

The above-mentioned Japanese Patent Application Laid-Open No. Hei 8-363.
In No. 01, since a special image forming process is employed, the control of the image forming operation becomes complicated. Also, JP-A-8-32
In 8284 and JP-A-9-127711, an expensive azo pigment is used, so that the production cost increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photoreceptor which has a high sensitivity to light having a relatively long wavelength, a high image forming speed, a simple control of an image forming operation, and a low production cost, and an image using the same. It is to provide a forming method.

[0007]

According to the present invention, there is provided an electrophotographic photoreceptor which is used repeatedly and has at least an undercoat layer and a photoconductive layer formed on a conductive support. An electrophotographic photoreceptor comprising a treated titanium oxide and a binder resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance.

According to the present invention, the undercoat layer on the support contains the surface-treated titanium oxide and the binder resin, and the photoconductive layer on the undercoat layer contains phthalocyanine. It is possible to stabilize the charging potential at the time of repeated use by increasing the first-time charging potential. Also,
Since phthalocyanine is used, high sensitivity to light having a relatively long wavelength is obtained. Therefore, in an image forming operation using such a photoconductor, an image can be formed from the first time by simple control without employing a special image forming process. Further, since an expensive azo pigment is not used, the photoreceptor can be manufactured at low cost.

Further, the present invention is characterized in that the ratio of titanium oxide to the binder resin in the undercoat layer is in the range of 5.0 to 30.0 by titanium oxide / binder resin (weight ratio). And

According to the present invention, the ratio of titanium oxide to the binder resin in the undercoat layer is in the range of 5.0 to 30.0 by weight of titanium oxide / binder resin. However, it is particularly preferable to obtain a high charging potential from the first rotation.

Further, the present invention is characterized in that the average particle diameter of the titanium oxide is in the range of 0.005 μm or more and 0.1 μm or less.

According to the present invention, it is preferable that the average particle diameter of the titanium oxide is in the range of 0.005 μm or more and 0.1 μm or less to obtain a high charging potential from the first rotation and to provide a coating liquid for an undercoat layer. It is particularly preferable for obtaining high stability.
If the average particle size of the titanium oxide is larger than this range, the titanium oxide precipitates in the coating liquid, and the stability is reduced.

Further, the present invention is characterized in that the surface treatment applied to the titanium oxide is any one of an alumina treatment, a silica treatment and an aluminum laurate treatment.

According to the present invention, it is particularly preferable that the surface of the titanium oxide is subjected to any one of an alumina treatment, a silica treatment and an aluminum laurate treatment.

The present invention also provides an electrophotographic photoreceptor that is used repeatedly, wherein at least an undercoat layer and a photoconductive layer are formed on a conductive support, wherein the undercoat layer comprises at least:
An electrophotographic photoreceptor comprising a surface-untreated titanium oxide and a binder resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance.

According to the present invention, the undercoat layer on the support contains untreated titanium oxide and a binder resin, and the photoconductive layer on the undercoat layer contains phthalocyanine. By increasing the first-time charging potential of the body, the charging potential during repeated use can be stabilized. In addition, since phthalocyanine is used, the sensitivity to relatively long wavelength light is high. Therefore, even in an image forming operation using such a photoconductor, an image can be formed from the first time by simple control without employing a special image forming process. Further, since an expensive azo pigment is not used, the photoreceptor can be manufactured at low cost.

Further, the present invention is characterized in that the ratio of titanium oxide to binder resin in the undercoat layer is in the range of 3.0 to 30.0 (weight ratio) of titanium oxide / binder resin. And

According to the present invention, the ratio of titanium oxide to the binder resin in the undercoat layer is in the range of 3.0 to 30.0 by weight of titanium oxide / binder resin. However, it is particularly preferable to obtain a high charging potential from the first rotation.

Further, the present invention is characterized in that the average particle size of the titanium oxide is in the range of 0.005 μm to 0.1 μm.

According to the present invention, it is preferable that the average particle diameter of the titanium oxide is in the range of 0.005 μm to 0.1 μm, and particularly in the range of 0.01 μm to 0.1 μm. It is particularly preferable for obtaining a high charging potential from the eyes and dispersing titanium oxide in the binder resin without agglomeration to obtain a stable undercoat layer coating liquid.

The present invention also relates to an electrophotographic photoreceptor that is used repeatedly, wherein at least an undercoat layer and a photosensitive layer are formed on a conductive support, wherein the undercoat layer comprises at least a surface-treated zinc oxide. An electrophotographic photoreceptor comprising a binder resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance.

According to the present invention, the undercoat layer on the support contains the surface-treated zinc oxide and the binder resin, and the photoconductive layer on the undercoat layer contains phthalocyanine. It is possible to stabilize the charging potential at the time of repeated use by increasing the first-time charging potential. In addition, since phthalocyanine is used, the sensitivity to relatively long wavelength light is high. Therefore, even in an image forming operation using such a photoconductor, an image can be formed from the first time by simple control without employing a special image forming process. Also, because expensive azo pigments are not used,
The photoreceptor can be manufactured at low cost.

Further, the present invention is characterized in that the surface treatment applied to the zinc oxide is an alumina treatment or a silica treatment.

According to the present invention, the surface treatment of the zinc oxide is particularly preferably an alumina treatment or a silica treatment.

The present invention also relates to an electrophotographic photoreceptor to be used repeatedly, wherein at least an undercoat layer and a photosensitive layer are formed on a conductive support, wherein the undercoat layer comprises at least a surface-untreated zinc oxide. An electrophotographic photoreceptor comprising a binder resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance.

According to the present invention, the undercoat layer on the support contains untreated zinc oxide and a binder resin, and the photoconductive layer on the undercoat layer contains phthalocyanine. It is possible to stabilize the charging potential at the time of repeated use by increasing the first-time charging potential. In addition, since phthalocyanine is used, the sensitivity to relatively long wavelength light is high. Therefore, even in an image forming operation using such a photoconductor, an image can be formed from the first time by simple control without employing a special image forming process. Further, since an expensive azo pigment is not used, the photoreceptor can be manufactured at low cost.

Further, the present invention is characterized in that the ratio of zinc oxide to the binder resin in the undercoat layer is in the range of 1.5 to 30.0 by weight of zinc oxide / binder resin. And

According to the present invention, it is preferable that the weight ratio of the surface-treated or surface-untreated zinc oxide to the binder resin in the undercoat layer is in the range of 1.5 to 30.0. It is particularly preferable to obtain a high charging potential from the rotation.

In the present invention, the phthalocyanine is preferably
(A) In the X-ray diffraction spectrum, the Bragg angle (2θ
± 0.2 °) 7.3 °, 9.4 °, 9.6 °, 11.6
°, 13.3 °, 17.9 °, 24.1 ° and 27.
A major peak is shown at 2 °, the overlapping peak bundle of 9.4 ° and 9.6 ° shows the highest peak intensity, and 27.
Crystalline oxotitanium phthalocyanine having a peak at 2 ° showing the second peak intensity. (B) In X-ray diffraction spectrum, Bragg angle (2θ ± 0.2 °) 9.5 °, 9.
7 °, 11.7 °, 15.0 °, 23.5 °, 24.1
Crystalline oxotitanium phthalocyanine showing major peaks at 0 ° and 27.3 °. (C) In X-ray diffraction spectrum, Bragg angle (2θ ± 0.2 °) 9.0 °, 1
Crystalline oxotitanium phthalocyanine showing major peaks at 4.2 °, 23.9 ° and 27.1 °, (d)
It is characterized by being one or a mixture of two or more of τ-type metal-free phthalocyanine and (e) X-type metal-free phthalocyanine.

According to the present invention, the above-mentioned (a) is added to the photoconductive layer.
It is possible to use any one or a mixture of two or more of crystalline oxotitanium phthalocyanine, (d) τ-type metal-free phthalocyanine, and (e) X-type metal-free phthalocyanine which show the X-ray spectra of (c) to (c). It is particularly preferable to obtain high charging potential and high sensitivity from the first rotation.

Further, according to the present invention, the undercoat layer has a thickness of 1 μm.
It is characterized by being in the range of not less than m and not more than 10 μm.

According to the present invention, any one of the above-mentioned surface-treated titanium oxide, surface-untreated titanium oxide, surface-treated zinc oxide, and surface-untreated zinc oxide, and a binder resin are contained. It is particularly preferable to select the thickness of the undercoat layer in the range of 1 μm to 10 μm in order to obtain a high charging potential from the first rotation. Undercoat layer thickness is 1 μm
If it is smaller than this, image defects caused by defects in the undercoat layer become remarkable, and if it is larger than 10 μm, generation of residual potential due to charge accumulation in the undercoat layer becomes remarkable.

Further, the present invention is characterized in that the binder resin of the undercoat layer is a curable resin.

According to the present invention, the undercoat layer contains any one of the above-mentioned surface-treated titanium oxide, surface-untreated titanium oxide, surface-treated zinc oxide and surface-untreated zinc oxide. As the binder resin to be used, a resin which is hardly soluble in an organic solvent for the photoconductive layer is preferable in consideration of applying the photoconductive layer formed thereon using a solvent, and particularly a curable resin. It is preferable to use

In the present invention, the curable resin preferably comprises (a)
Mixture of alkyd resin and melamine resin, (b) mixture of acrylic resin and melamine resin, (c) mixture of epoxy ester resin and melamine resin, (d) mixture of alkyd resin, melamine resin and epoxy resin, and (e) acrylic It is one of a mixture of a resin, a melamine resin, and an epoxy resin.

According to the present invention, examples of the curable resin include resins having a three-dimensional network structure. Specifically, a mixture of any of the above (a) to (e) can be used. Particularly preferred.

According to the present invention, there is provided an image forming method for forming an image by rotating an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member described in any of the above is used as the electrophotographic photosensitive member. Is used for image formation from the first rotation.

According to the present invention, in an image forming method for forming an image by rotating an electrophotographic photosensitive member, an image is formed at a high speed by using the photosensitive member for image formation from the first rotation. It is possible to do.

[0039]

FIG. 1 is a sectional view showing an electrophotographic photosensitive member 1 according to an embodiment of the present invention. Photoconductor 1
Is formed by providing at least an undercoat layer 3 and a photoconductive layer 4 on a conductive support 2 in this order. The photoconductive layer 4 in FIG. 1 is a function-separated type in which a charge generation layer 5 and a charge transport layer 6 are laminated, but the photoconductive layer 4 is a single layer type having a single layer having both a charge generation function and a charge transport function. It does not matter. Further, a surface protective layer may be provided on the photoconductive layer 4.

The support 1 may be a metal drum such as aluminum, aluminum alloy, copper, zinc, nickel, stainless steel and titanium. Further, a sheet made of the above metal, a sheet made of a polymer resin such as polyethylene terephthalate, phenol resin, nylon and polystyrene, a glass plate, and a drum or sheet obtained by laminating a metal foil on a hard paper or the like and performing a conductive treatment. And seamless belts. Further, a conductive material such as titanium oxide, tin oxide, indium oxide and carbon black is applied on the above-mentioned metal sheet, polymer resin sheet, glass plate, hard paper, etc. together with a suitable binder resin to conduct a conductive treatment. Drums, sheets and seamless belts.

The binder resin used for the undercoat layer 3 is a resin having a high solvent resistance to general organic solvents in consideration of applying the photoconductive layer 4 thereon with a solvent. Desirably. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein and polyvinyl acetal, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, acrylic resins, alkyd resins, polyurethanes, melamine resins, epoxy resins, and phenols. Resin and a curable resin forming a three-dimensional network structure such as a urea resin.

Among the above curable resins, (a) a mixture of an alkyd resin and a melamine resin, (b) a mixed resin of an acrylic resin and a melamine resin, (c) a mixture of an epoxy ester resin and a melamine resin, (d) an alkyd It is preferable to use one of a mixture of a resin, a melamine resin and an epoxy resin, and (e) a mixture of an acrylic resin, a melamine resin and an epoxy resin.

The titanium oxide contained in the undercoat layer 3 together with the binder resin is preferably a surface-treated titanium oxide or a surface-untreated titanium oxide. As the surface treatment, an alumina surface treatment, a silica surface treatment, or an aluminum laurate treatment is preferable. Furthermore, when the surface-treated titanium oxide is contained in consideration of the dispersion stability of titanium oxide, the ratio of titanium oxide / binder resin (weight ratio) may be selected within a range of 5.0 or more and 30.0 or less. Preferably
When the surface-untreated titanium oxide is contained, it is preferable to select the titanium oxide / binder resin (weight ratio) in the range of 3.0 or more and 30.0 or less. Further, in order to stably disperse and use the surface-treated titanium oxide and the surface-untreated titanium oxide in the binder resin, the average particle diameter of these titanium oxides is 0.005 μm or more and 0.1 μm or less. range,
In particular, it is preferable to select the range of 0.01 μm or more and 0.1 μm or less.

The zinc oxide contained in the undercoat layer 3 together with the binder resin is preferably surface-treated zinc oxide or surface-untreated zinc oxide. As the surface treatment, a treatment with an inorganic compound such as an alumina surface treatment and a silica surface treatment is preferable from the viewpoint of improving dispersibility, and a surface treatment with an organic compound such as stearic acid may be used. Further, in the case of using untreated zinc oxide, the purity of the zinc oxide is preferably set to 99% or more. Also, considering the dispersion stability of zinc oxide,
Zinc oxide / binder resin (weight ratio) together with zinc oxide with surface treatment and zinc oxide with no surface treatment
Is preferably selected in the range of 1.5 to 30.0. Further, in order to stably disperse and use the surface-treated zinc oxide and the surface-untreated zinc oxide in the binder resin, it is preferable to select the average particle size of these zinc oxides within a range of 1 μm or less. .

The thickness of the undercoat layer 3 is 0.1 μm to 50 μm.
It is preferable to select the range of not more than 1 μm, particularly preferably not less than 1 μm and not more than 10 μm. When the film thickness is smaller than 0.1 μm, it does not substantially function as the undercoat layer 3, does not provide uniform surface properties covering defects of the support 1, and prevents carrier injection from the support 1. , And the chargeability decreases.
On the other hand, if it is larger than 50 μm, it is difficult to form the undercoat layer 3 by the dip coating method, and the mechanical strength of the coating film is reduced.

The coating liquid for the undercoat layer is dispersed using a ball mill, a sand mill, an attritor, a vibration mill, a colloid mill, an ultrasonic disperser, or the like, and the undercoat layer 3 is formed by a dipping method, a spray method, a bead method, or the like. It is formed by a general coating method such as a nozzle method.

By forming the undercoat layer 3, a high charging potential can be obtained from the first rotation, but furthermore, image defects (black spots) which are considered to be mainly caused by charge leakage from the support 2 during the reversal phenomenon. Can be prevented. Also,
By acting as a barrier layer between the support 2 and the photoconductive layer 4, the electrostatic fatigue properties are improved. Further, the support 2
And the photoconductive layer 4 have improved adhesion.

The structure of the photoconductive layer 4 formed on the undercoat layer 3 is, as described above, a function-separated type composed of two layers, that is, the charge generation layer 5 and the charge transport layer 6, and these are not separated. Any single-layer type formed of a single layer may be used.

In the function-separated type photoconductive layer 4, for example, the charge generation layer 5 is formed on the undercoat layer 3. The charge generation layer 5 contains phthalocyanine as a charge generation substance. As the phthalocyanine, (a) in the X-ray diffraction spectrum, a Bragg angle (2θ ± 0.2 °) of 7.3 °,
9.4 °, 9.6 °, 11.6 °, 13.3 °, 17.
The major peaks are shown at 9 °, 24.1 ° and 27.2 °, the overlapping peak bundle of 9.4 ° and 9.6 ° shows the maximum peak intensity, and the peak at 27.2 ° is Crystalline oxotitanium phthalocyanine as shown in FIG. 2 showing the second peak intensity, (b) in X-ray diffraction spectrum, Bragg angles (2θ ± 0.2 °) 9.5 °, 9.7
°, 11.7 °, 15.0 °, 23.5 °, 24.1 °
And crystalline form oxotitanium phthalocyanine as shown in FIG. 3 showing the major peak at 27.3 °, (c)
In the X-ray diffraction spectrum, the Bragg angle (2θ ± 0.
2 °) 9.0 °, 14.2 °, 23.9 ° and 27.
As shown in FIG. 4, which shows a main peak at 1 °, one or more of crystalline oxotitanium phthalocyanine, (d) τ-type metal-free phthalocyanine and (e) X-type metal-free phthalocyanine It is preferred to use a mixture.

Examples of the charge generating material include, in addition to the phthalocyanine, bisazo compounds such as chlorodiane blue, polycyclic quinone compounds such as dibromoanthanthrone, perylene compounds, quinacridone compounds, and azurenium salt compounds. May be used alone or in combination of two or more.

As a method for forming the charge generation layer 5, there are a method of forming the charge generation substance by vacuum deposition and a method of dispersing and applying the charge generation substance in a binder resin solution to form a film. Generally, the latter coating method is preferred. When the charge generation layer 5 is formed by a coating method, a method similar to that of the undercoat layer 3 can be adopted as a method of mixing and dispersing the charge generation substance in the binder resin solution and a method of applying the same.

As the binder resin for the charge generation layer, melamine resin, epoxy resin, silicone resin, polyurethane,
Insulating resins such as acrylic resins, polycarbonates, polyarylates, phenoxy resins, butyral resins, and copolymer resins containing two or more repeating units.
Examples of the copolymer resin containing two or more repeating units include a vinyl chloride-vinyl acetate copolymer resin and an acrylonitrile-styrene copolymer resin. The binder resin for the charge generation layer is not limited to these insulating resins, and general resins can be used alone or in combination of two or more.

Examples of the solvent for dissolving the binder resin for the charge generation layer include halogenated hydrocarbons such as methylene chloride and ethane dichloride, ketones such as acetone, methyl ethyl ketone and cyclohexane, and esters such as ethyl acetate and butyl acetate. , Ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, and N, N-
Aprotic polar solvents such as dimethylformamide and N, N-dimethylacetamide can be used.

It is preferable that the thickness of the charge generation layer 5 is selected in the range of 0.05 μm to 5 μm, particularly in the range of 0.1 μm to 1 μm.

In the function-separated type photoconductive layer 4, a charge transport layer 6 is provided on the charge generation layer 5. As a method for forming the charge transport layer 6, a method is generally used in which a charge transport coating solution in which a charge transport material is dissolved in a binder resin solution is prepared, and this is applied to form a film. As the charge transport material, hydrazone compounds, pyrazoline compounds, triphenylamine compounds, triphenylmethane compounds,
Stilbene compounds, oxadiazole compounds, enamine compounds and the like are known, and these can be used alone or in combination of two or more. As the binder resin for the charge transport layer, one or a mixture of two or more of the binder resins for the charge generation layer can be used. It is preferable that the thickness of the charge transport layer 6 be selected in a range of 5 μm or more and 50 μm or less, and particularly in a range of 10 μm or more and 40 μm or less.

The thickness of the photoconductive layer 4 having a single layer structure is 5 μm.
It is preferable to select the thickness in the range of not less than 50 μm and particularly not less than 10 μm and not more than 40 μm.

In order to improve sensitivity, reduce residual potential, and reduce fatigue during repeated use, the photoconductive layer 4
, One or more electron accepting substances may be added. Examples of the electron accepting substance include parabenzoquinone, chloranil, tetrachloro1,2-benzoquinone, hydroquinone, 2,6-dimethylbenzoquinone,
Quinone-based compounds such as 4-benzoquinone, α-naphthoquinone and β-naphthoquinone, 2,4,7-trinitro-9-fluorenone, 1,3,6,8-tetranitrocarbazole, p-nitrobenzophenone, 2,4,4 5,
Nitro compounds such as 7-tetranitro-9-fluorenone and 2-nitrofluorenone, and tetracyanoethylene, 7,7,8,8-tetracyanoquinodimethane, 4- (p-nitrobenzoyloxy) -2 ', 2 ′
And cyano compounds such as -dicyanovinylbenzene and 4- (m-nitrobenzoyloxy) -2 ', 2'-dicyanovinylbenzene. Among these electron accepting substances, fluorenone-based compounds, quinone-based compounds, and benzene derivatives having electron-withdrawing substituents such as Cl, CN and NO ₂ are particularly preferred.

Also, ultraviolet absorbers and antioxidants such as benzoic acid, stilbene compounds and derivatives thereof, and nitrogen-containing compounds such as triazole compounds, imidazole compounds, axadiazole compounds, thiazole compounds and derivatives thereof are added to the photoconductive layer. 4 may be added.

If necessary, a dibasic acid ester,
A plasticizer such as a fatty acid ester, a phosphate ester, a phthalate ester and a chlorinated paraffin, or a leveling agent such as a silicone resin is mixed into the photoconductive layer 4 to impart workability and flexibility, thereby improving mechanical properties. It can be improved.

Further, if necessary, a protective layer may be provided to protect the surface of the photoconductive layer 4. As the surface protective layer, a thermoplastic resin, a light or thermosetting resin can be used. The surface protective layer may contain the ultraviolet absorber, antioxidant, inorganic material such as metal oxide, organometallic compound, electron-accepting substance, plasticizer, leveling agent, and the like.

The method of forming an image by rotating the electrophotographic photosensitive member 1 as described above, and an image forming method using the photosensitive member 1 for image formation from the first rotation is also within the scope of the present invention. Belong to.

Hereinafter, the present invention will be described with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 65 mm in diameter and 332 m in length
m of an aluminum drum-shaped support 2 was coated with an undercoat layer coating solution having the following composition dispersed for 10 hours using a paint shaker and dried at 130 ° C. for 20 minutes to give a film thickness of 3 μm. The undercoat layer 3 was formed. In the undercoat layer coating liquid, the titanium oxide / binder resin (weight ratio) is 6.
0.

[Coating solution for undercoat layer] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 14 parts by weight Melamine resin (solid content: 60%) L125-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight Next, the following composition was dispersed on the undercoat layer 3 by a sand mill for 3 hours. Dip coating of the charge generation layer coating solution
At 10 ° C. for 10 minutes to form a charge generation layer 5 having a thickness of 0.3 μm.
Was formed.

[Coating Solution for Charge Generating Layer] Crystalline oxotitanium phthalocyanine 3 parts by weight Vinyl chloride-vinyl acetate-polyvinyl alcohol copolymer SOLBIN A5 (manufactured by Nissin Chemical Co., Ltd.) 2 parts by weight Methyl ethyl ketone 100 parts by weight Example 1 The crystalline oxotitanium phthalocyanine used in the above was obtained by using CuKα = 1.54050 ° as an X-ray source and θ /
When the diffraction spectrum was measured by the 2θ scanning method, an X-ray diffraction spectrum as shown in FIG. 2 was obtained. From FIG.
This crystalline oxotitanium phthalocyanine has a black angle (2θ ± 0.2 °) of 7.3 °, 9.4 °, 9.6.
°, 11.6 °, 13.3 °, 17.9 °, 24.1 °
And major diffraction peaks at 27.2 °, especially 9.
It can be seen that the overlapping peak bundles at 4 ° and 9.6 ° show the maximum peak intensity and the peak at 27.2 ° shows the second peak intensity.

Next, a charge transport layer coating solution having the following composition, which had been stirred and dissolved, was applied onto the charge generation layer 5 by dip coating.
Dry at 0 ° C. for 20 minutes to form a charge transport layer 6 having a thickness of 30 μm.
Was formed to obtain Photoreceptor 1.

[Charge Transport Layer Coating Solution] 8 parts by weight of a charge transport material of the following structural formula (I)

[0068]

Embedded image

Polycarbonate Z200 (manufactured by Mitsubishi Gas Chemical Company) 10 parts by weight Silicon oil KF50 (manufactured by Shin-Etsu Chemical Co.) 0.002 parts by weight Dichloromethane 120 parts by weight

Comparative Example 1 A photoreceptor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, barium sulfate / binder resin (weight ratio) was 6.0.

[Undercoat layer coating solution] Barium sulfate BF-10 (manufactured by Sakai Chemical Co., Ltd.) 60 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (Sodium content 60%) L125-60 (Dai Nippon Ink Co., Ltd.) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Comparative Example 2 Comparative Example 1 was repeated except that the crystalline oxotitanium phthalocyanine used in the charge generation layer coating liquid prepared in Example 1 was replaced with a trisazo pigment of the following structural formula (II). Photoconductor 1 was prepared in the same manner.

[0073]

Embedded image

Example 2 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat layer coating liquid] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 40 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 14 parts by weight Melamine resin (solid content concentration 60%) L125-60 (manufactured by Dainippon Ink) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 3 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 5.0.

[Undercoat Layer Coating Solution] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 50 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L125-60 (manufactured by Dainippon Ink) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 4 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 10.0.

Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo Co., Ltd.) 100 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dai Nippon Ink Co., Ltd.) 14 parts by weight Melamine resin (solid content) L125-60 (Dai Nippon Ink Co., Ltd.) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 5 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 6.0. The titanium oxide TTO-55A used in Example 1 has an average particle size of 0.04 μm, whereas the titanium oxide R630 used in Example 5 has an average particle size of 0.24 μm.

[Undercoat layer coating liquid] Titanium oxide (surface alumina treatment) R630 (manufactured by Ishihara Sangyo) 60 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Part Melamine resin (solid content concentration 60%) L125-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 6 A photoconductor 1 was prepared in the same manner as in Example 1, except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 6.0.

[Undercoat Layer Coating Solution] Titanium oxide (surface silica treatment) STR-60S (manufactured by Sakai Chemical Co.) 60 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 14 parts by weight Melamine resin (solid content concentration 60%) L125-60 (manufactured by Dainippon Ink) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 7 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 6.0.

[Undercoat layer coating liquid] Titanium oxide (surface treated with aluminum uranate) MT-100S (manufactured by Teica) 60 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 14 parts by weight Melamine resin (solid content concentration 60%) L125-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 8 An X-ray diffraction spectrum shown in FIG. 3 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum shown in FIG. 2 used in the charge generation layer coating liquid prepared in Example 1. Photoconductor 1 was prepared in the same manner as in Example 1, except that crystalline oxotitanium phthalocyanine was used. From FIG. 3, it can be seen that this crystalline oxotitanium phthalocyanine has a black angle (2θ ± 0.2 °).
9.5 °, 9.7 °, 11.7 °, 15.0 °, 23.
It can be seen that there are major diffraction peaks at 5 °, 24.1 ° and 27.3 °.

Example 9 The X-ray diffraction spectrum of FIG. 4 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum of FIG. 2 used in the charge generation layer coating liquid prepared in Example 1. Photoconductor 1 was prepared in the same manner as in Example 1, except that crystalline oxotitanium phthalocyanine was used. As shown in FIG. 4, this crystalline oxotitanium phthalocyanine has a black angle (2θ ± 0.2 °).
It can be seen that there are major diffraction peaks at 0 °, 14.2 °, 23.9 ° and 27.1 °.

Example 10 Instead of the crystalline oxotitanium phthalocyanine used in the charge generation layer coating solution prepared in Example 1, a τ-type metal-free phthalocyanine (Liophoto
n TPA-891, manufactured by Toyo Ink Co., Ltd.) was used in the same manner as in Example 1 to prepare a photoreceptor 1.

Example 11 In place of the crystalline oxotitanifurphthalocyanine used in the charge generation layer coating liquid prepared in Example 1, X-ray metal-free phthalocyanine (Fastogen) was used.
Photoconductor 1 was prepared in the same manner as in Example 1 except that Blue 8120BS (manufactured by Dainippon Ink) was used.

Example 12 A photoreceptor 1 was prepared in the same manner as in Example 1 except that the thickness of the undercoat layer 3 of the photoreceptor 1 prepared in Example 1 was changed to 0.5 μm.

Example 13 A photoreceptor 1 was prepared in the same manner as in Example 1 except that the thickness of the undercoat layer 3 of the photoreceptor 1 prepared in Example 1 was changed to 1 μm.

Example 14 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 6.0.

[Undercoat layer coating solution] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Polyamide CM8000 (manufactured by Toray Industries) 10 parts by weight Methanol 54 parts by weight n-butanol 36 parts by weight

Example 15 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 6.0.

[Undercoat layer coating solution] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Alkyd resin (solid content concentration: 50%) M6402-50 (manufactured by Dainippon Ink) 16 Parts by weight Melamine resin (solid content: 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 3.3 parts by weight Methyl ethyl ketone 51 parts by weight

Example 16 A photoconductor 1 was prepared in the same manner as in Example 1, except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 6.0.

[Undercoat layer coating liquid] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Acrylic resin (solid content concentration 60%) A460-60 (manufactured by Dainippon Ink and Chemicals) 12 0.5 parts by weight Melamine resin (solid content: 60%) G821-60 (manufactured by Dainippon Ink and Chemicals) 4.2 parts by weight Methyl ethyl ketone 54 parts by weight

Example 17 A photoconductor 1 was prepared in the same manner as in Example 1, except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 6.0.

[Coating solution for undercoat layer] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Alkyd resin (solid content concentration 50%) M6402-50 (manufactured by Dainippon Ink) 12 Parts by weight Melamine resin (solid content 60%) L117-60 (Dai Nippon Ink) 3.3 parts by weight Epoxy resin (solid content 70%) 1050-70X (Dai Nippon Ink) 2.9 parts by weight 52 parts by weight of methyl ethyl ketone

Example 18 A photoconductor 1 was prepared in the same manner as in Example 1, except that the coating liquid for the undercoat layer prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 5.7.

[Undercoat layer coating liquid] Titanium oxide (surface alumina treatment) TTO-55A (manufactured by Ishihara Sangyo) 60 parts by weight Acrylic resin (solid content concentration 60%) A460-60 (manufactured by Dainippon Ink and Chemicals) 10 Parts by weight Melamine resin (solid content 60%) G821-60 (Dai Nippon Ink) 4.2 parts by weight Epoxy resin (solid content 70%) 1050-70X (Dai Nippon Ink) 2.9 parts by weight 54 parts by weight of methyl ethyl ketone

(Evaluation 1) The photoreceptor 1 prepared in Examples 1, 6, 7 and Comparative Examples 1 and 2 was mounted on a digital copier AR-5130 modified machine manufactured by Sharp Corporation. The dark part potential (VO) and the light part potential (VL) were measured. Further, the photoreceptor 1 after the copying operation of 30K sheets is left in a dark place for 2 hours, and the difference between the dark portion potential of the first rotation and the dark portion potential of the fifth rotation of the photoreceptor 1 is determined as dVO, and the difference is obtained as dVO. Of the charging potential. Table 1 shows the results. dVO = | VO at the first rotation |-| VO at the fifth rotation |

[0103]

[Table 1]

Table 2 shows the results of evaluating the stability of the dispersion by keeping the undercoat layer coating liquids prepared in Examples 1, 5, 6, and 7 for 7 days.

[0105]

[Table 2]

From the above results, it can be seen that a high charging potential can be obtained from the first rotation by including titanium oxide in the undercoat layer. In addition, it can be seen that a photosensitive member using an azo pigment as a charge generating substance can obtain a high charging potential from the first rotation. Therefore, it is understood that the low charging potential in the first rotation is unique when phthalocyanine is used as the charge generating substance. As will be described later, the stability of the dispersion (coating solution for the undercoat layer) depends on the average particle size of the titanium oxide, and if the particle size is large, a sedimentation state is observed and the stability is poor.

(Evaluation 2) Table 3 shows the results of evaluating the electrostatic characteristics of the photoreceptor 1 prepared in Examples 1 to 4 in the same manner as in Evaluation 1.

[0108]

[Table 3]

From the above results, it was found that the titanium oxide /
It can be seen that when the binder resin (weight ratio) is 5.0 or more, a high charging potential can be obtained from the first rotation.

(Evaluation 3) Table 4 shows the evaluation results of the electrostatic properties and the stability of the coating solution of the photoreceptor 1 prepared in Examples 1 and 5 in the same manner as in Evaluation 1.

[0111]

[Table 4]

From the above results, it can be seen that a titanium oxide having an average particle size of 0.1 μm or less can obtain a high charging potential from the first rotation and is excellent in the stability of the coating liquid.

(Evaluation 4) Table 5 shows the evaluation results of the electrostatic characteristics of the photoreceptors 1 prepared in Examples 1 and 8 to 11 in the same manner as in Evaluation 1.

[0114]

[Table 5]

From the above results, it is found that when the phthalocyanines of Examples 1, 8 to 11 are used as the charge generating substance, high sensitivity and a high charging potential can be obtained from the first rotation.

(Evaluation 5) Table 6 shows the results of evaluating the same electrostatic characteristics as in Evaluation 1 for the photoreceptors 1 prepared in Examples 1, 12, and 13.

[0117]

[Table 6]

From the above results, it was found that the thickness of the undercoat layer 3 was 1.
It is understood that when the thickness is 0 μm or more, a high charging potential is obtained particularly from the first rotation.

(Evaluation 6) With respect to the photoreceptor 1 prepared in Examples 1 and 14 to 18, the same electrostatic characteristics as those of the evaluation 1 were evaluated, and a total of 5 × 5 on the photoreceptor 1 at intervals of 2 mm 2
Table 7 shows the results of an evaluation of the adhesiveness in which five grid-shaped cuts were made, peeled off with cellophane tape, and the number of meshes remaining on the photoreceptor 1 was evaluated. The adhesiveness is
It is expressed by the number of squares remaining on the photoreceptor 1 after peeling off the cellophane tape / 25.

[0120]

[Table 7]

From the above results, it can be seen that in Examples 1, 15 to 18 in which the curable resin was used, a high charging potential was obtained from the first rotation, and excellent potential stability was obtained during repeated use. Further, in Example 17, where an epoxy resin was added,
18 shows that the adhesiveness is superior to Examples 15 and 16 in which no epoxy resin is added.

(Example 19) A diameter of 65 mm and a length of 332
mm on a drum-shaped support 2 made of aluminum,
An undercoat layer coating solution having the following composition, which had been dispersed by a paint shaker for 10 hours, was applied by dip coating and dried at 130 ° C. for 20 minutes to form an undercoat layer 3 having a thickness of 3 μm. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.
It is. The average particle size of zinc oxide FINEX-25 is 0.04 μm.

[Undercoat Layer Coating Solution] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co.) 50 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (Solid content concentration 60%) J820-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Next, on the undercoat layer 3, a charge generation layer coating solution having the following composition, which was dispersed for 2 hours with a paint shaker, was applied by dip coating, and dried at 120 ° C. for 10 minutes. 3
A charge generation layer 5 of μm was formed. The crystalline oxotitanium phthalocyanine used in Example 19 shows an X-ray diffraction spectrum as shown in FIG.

[Charge Generating Layer Coating Solution] Crystalline oxotitanium phthalocyanine 2 parts by weight Polyvinyl butyral BX-1 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Methyl ethyl ketone 100 parts by weight

Next, a charge transport layer coating solution having the following composition, which had been stirred and dissolved, was applied onto the charge generation layer 5 by dip coating.
Dry at 0 ° C. for 20 minutes to form a charge transport layer 6 having a thickness of 30 μm.
Was formed to obtain Photoreceptor 1.

[Charge Transport Layer Coating Solution] 8 parts by weight of a charge transport material of the following structural formula (III)

[0128]

Embedded image

Polycarbonate K1300 (manufactured by Teijin Chemicals Limited) 10 parts by weight Silicon oil KF50 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.002 parts by weight Dichloromethane 120 parts by weight

Example 20 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.
The average particle size of zinc oxide SAZEX is 0.5 μm.

[Undercoat Layer Coating Solution] Zinc oxide SAZEX (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid) J820-60 (manufactured by Dainippon Ink) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Comparative Example 3 A photoreceptor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, barium sulfate / binder resin (weight ratio) is 5.0.

[Undercoat layer coating liquid] Barium sulfate BF-20 (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (Solid content concentration 60%) J820-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Comparative Example 4 Comparative Example 3 was repeated except that a trisazo pigment having the following structural formula (IV) was used instead of the crystalline oxotitanium phthalocyanine used in the charge generation layer coating solution prepared in Example 19. Photoconductor 1 was prepared in the same manner.

[0135]

Embedded image

Example 21 The X-ray diffraction spectrum shown in FIG. 3 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum shown in FIG. 2 used in the coating solution for the charge generation layer prepared in Example 19. Photoconductor 1 was prepared in the same manner as in Example 19, except that crystalline oxotitanium phthalocyanine was used.

Example 22 An X-ray diffraction spectrum shown in FIG. 4 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum shown in FIG. 2 used in the coating solution for the charge generation layer prepared in Example 19. Photoconductor 1 was prepared in the same manner as in Example 19, except that crystalline oxotitanium phthalocyanine was used.

(Example 23) Instead of the crystalline oxotitanium phthalocyanine used in the charge generation layer coating solution prepared in Example 19, a τ-type metal-free phthalocyanine (Liopho
Photoconductor 1 was prepared in the same manner as in Example 19 except that ton TPA-891 (manufactured by Toyo Ink) was used.

(Example 24) In place of the crystalline oxotitanifurphthalocyanine used for the charge generation layer coating solution prepared in Example 19, an X-ray metal-free phthalocyanine (Fastog) was used.
Photoconductor 1 was prepared in the same manner as in Example 19, except that enBlue 8120BS (manufactured by Dainippon Ink) was used.

Example 25 A photoconductor 1 was prepared in the same manner as in Example 19, except that the thickness of the undercoat layer 3 of the photoconductor 1 prepared in Example 19 was changed to 1 μm.

(Example 26) Except that the thickness of the undercoat layer 3 of the photoreceptor 1 prepared in Example 19 was changed to 0.5 μm,
Photoconductor 1 was prepared in the same manner as in Example 19.

Example 27 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.

[Undercoat Layer Coating Solution] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co.) 50 parts by weight Polyamide CM8000 (manufactured by Toray Industries) 10 parts by weight Methanol 54 parts by weight n-butanol 36 parts by weight

Example 28 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.

[Undercoat Layer Coating Solution] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Alkyd resin (solid content concentration: 50%) M6402-50 (manufactured by Dainippon Ink Co., Ltd.) 16 parts by weight Melamine resin ( J820-60 (manufactured by Dainippon Ink) 3.3 parts by weight Methyl ethyl ketone 51 parts by weight

Example 29 A photoconductor 1 was prepared in the same manner as in Example 19, except that the coating liquid for the undercoat layer prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.

[Undercoat Layer Coating Solution] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Acrylic resin (solid content concentration: 60%) A460-60 (manufactured by Dainippon Ink and Chemicals, Inc.) 12.5 parts by weight Melamine Resin (solid content: 60%) J820-60 (manufactured by Dainippon Ink) 4.2 parts by weight Methyl ethyl ketone 54 parts by weight

Example 30 A photoconductor 1 was prepared in the same manner as in Example 19, except that the coating liquid for the undercoat layer prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.

[Undercoat layer coating liquid] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Alkyd resin (solid content concentration: 50%) M6402-50 (manufactured by Dainippon Ink and Chemicals) 12 parts by weight Melamine resin ( J820-60 (manufactured by Dainippon Ink) 3.3 parts by weight Epoxy resin (solids concentration 70%) 1050-70X (manufactured by Dainippon Ink) 2.9 parts by weight Methyl ethyl ketone 52 parts by weight

Example 31 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 4.7.

[Undercoat Layer Coating Solution] Zinc oxide FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 50 parts by weight Acrylic resin (solid content concentration: 60%) A460-60 (manufactured by Dainippon Ink and Chemicals) 10 parts by weight Melamine resin ( J820-60 (manufactured by Dainippon Ink) 4.2 parts by weight Epoxy resin (solids concentration 70%) 1050-70X (manufactured by Dainippon Ink) 2.9 parts by weight Methyl ethyl ketone 53 parts by weight

Example 32 A photoconductor 1 was prepared in the same manner as in Example 19, except that the coating liquid for the undercoat layer prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.
The alumina component of the zinc oxide FINEX-25 treated alumina was 5% by weight of the whole.

[Undercoat layer coating liquid] Zinc oxide (alumina-treated product) FINEX-25 (manufactured by Sakai Chemical Co.) 50 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) J820-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 33 A photoconductor 1 was prepared in the same manner as in Example 19, except that the coating liquid for the undercoat layer prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 5.0.
In addition, the silica component of the silica-treated product of zinc oxide FINEX-25 is 4% by weight of the whole.

[Undercoat Layer Coating Solution] Zinc oxide (silica-treated product) FINEX-25 (manufactured by Sakai Chemical Co.) 50 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 14 parts by weight Melamine resin (solid content concentration 60%) J820-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 34 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, the ratio of zinc oxide / binder resin (weight ratio) was 2.0.

[Undercoat Layer Coating Solution] Zinc oxide (silica-treated product) FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 40 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dai Nippon Ink Co., Ltd.) 28 parts by weight Melamine resin (solid content: 60%) J820-60 (manufactured by Dainippon Ink) 10 parts by weight Methyl ethyl ketone 81 parts by weight

Example 35 A photoconductor 1 was prepared in the same manner as in Example 19, except that the undercoat layer coating liquid prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 1.5.

[Undercoat Layer Coating Solution] Zinc oxide (silica-treated product) FINEX-25 (manufactured by Sakai Chemical Co., Ltd.) 36 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 33.6 parts by weight Melamine resin (solid content: 60%) J820-60 (manufactured by Dainippon Ink) 12 parts by weight Methyl ethyl ketone 81 parts by weight

Example 36 A photoconductor 1 was prepared in the same manner as in Example 19, except that the coating liquid for the undercoat layer prepared in Example 19 was changed as follows. In the undercoat layer coating liquid, zinc oxide / binder resin (weight ratio) was 1.0.

[Undercoat Layer Coating Solution] Zinc oxide (silica-treated product) FINEX-25 (manufactured by Sakai Chemical) 30 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals, Inc.) 42 parts by weight Melamine resin (solid content: 60%) J820-60 (manufactured by Dainippon Ink and Chemicals) 15 parts by weight Methyl ethyl ketone 81 parts by weight

(Evaluation 7) Table 8 shows the results of evaluating the electrostatic characteristics of the photoreceptors 1 prepared in Examples 19 to 24 and Comparative Examples 3 and 4 in the same manner as in Evaluation 1 described above.

[0163]

[Table 8]

From the above results, it can be seen that a high charging potential can be obtained from the first rotation by containing zinc oxide in the undercoat layer. Also, it can be seen that a photoreceptor using an azo pigment as the charge generating substance can obtain a high charging potential from the first rotation. Therefore, it is understood that the phenomenon that the charging potential in the first rotation is low is unique when phthalocyanine is used as the charge generating substance.

(Evaluation 8) Table 9 shows the results of evaluating the electrostatic characteristics of the photoreceptor 1 prepared in Examples 19, 25 and 26 in the same manner as in Evaluation 7.

[0166]

[Table 9]

From the above results, it was found that the thickness of the undercoat layer 3 was 1 μm.
It can be seen that a high charging potential is obtained particularly from the first rotation when the value is not less than m.

(Evaluation 9) With respect to the photoreceptor 1 prepared in Examples 19 and 27 to 31, the electrostatic characteristics were evaluated in the same manner as in Evaluation 7, and a white solid image was formed by a reversal developing method using a digital copying machine. Image defects (black spots)
Table 10 shows the results of the evaluation of the adhesiveness.

[0169]

[Table 10]

From the above results, it can be seen that in Examples 19 and 28 to 31 using the curable resin, a high charging potential was obtained from the first rotation, and excellent potential stability was obtained during repeated use. Further, it can be seen that black spots are effectively prevented. Examples 30 and 3 further including an epoxy resin
1 shows that the adhesiveness is superior to Examples 28 and 29 in which no epoxy resin is added.

(Evaluation 10) With respect to the photoreceptor 1 prepared in Examples 19, 32 and 33, the same electrostatic characteristics as in Evaluation 7 were evaluated, and the prepared undercoat layer coating solution was allowed to stand and stored for 7 days. Table 11 shows the results of evaluating the stability of the dispersion.

[0172]

[Table 11]

From the above results, in Examples 32 and 33 in which the surface-treated zinc oxide was contained in the undercoat layer 3, a high charging potential was obtained from the first rotation, and excellent stability in the coating liquid was obtained. It turns out that it is possible. Further, in Example 19 in which the surface of the undercoat layer 3 contained untreated zinc oxide, a high charging potential was obtained from the first rotation.

(Evaluation 11) Table 12 shows the evaluation results of the electrostatic characteristics of the photoreceptor 1 prepared in Examples 19 and 34 to 36 in the same manner as in Evaluation 7.

[0175]

[Table 12]

From the above results, it was found that zinc oxide /
It can be seen that when the binder resin (weight ratio) is 1.5 or more, a high charging potential can be obtained from the first rotation.

(Example 37) 65 mm in diameter and 332 in length
mm on a drum-shaped support 2 made of aluminum,
An undercoat layer coating solution having the following composition, which had been dispersed by a paint shaker for 10 hours, was applied by dip coating and dried at 130 ° C. for 20 minutes to form an undercoat layer 3 having a thickness of 3 μm. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 4.
0.

[Undercoat layer coating liquid] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 40 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Next, 3 layers were placed on the undercoat layer 3 with a sand mill.
The charge generation layer coating solution having the following composition, which had been subjected to time dispersion treatment, was applied by dip coating and dried at 120 ° C. for 10 minutes to form a charge generation layer 5 having a thickness of 0.3 μm. Note that the crystalline oxotitanium phthalocyanine used in Example 1 was obtained as shown in FIG.
1 shows a line diffraction spectrum.

[Charge Generating Layer Coating Solution] Crystalline oxotitanium phthalocyanine 2 parts by weight Vinyl chloride-vinyl acetate-maleic acid copolymer SOLBIN M (manufactured by Nissin Chemical Industry Co., Ltd.) 2 parts by weight Methyl ethyl ketone 100 parts by weight

Next, a charge transport layer coating solution having the following composition, which had been stirred and dissolved, was applied onto the charge generation layer 5 by dip coating.
Dry at 0 ° C. for 20 minutes to form a charge transport layer 6 having a thickness of 30 μm.
Was formed to obtain Photoreceptor 1.

[Coating Solution for Charge Transport Layer] 8 parts by weight of the charge transport material of the structural formula (I) 10 parts by weight of polycarbonate Z200 (manufactured by Mitsubishi Gas Chemical Company) 10 parts by weight of silicone oil KF50 (manufactured by Shin-Etsu Chemical Co.) 0.002 part by weight 120 parts by weight of dichloromethane

(Comparative Example 5) A photoconductor 1 was prepared in the same manner as in Example 37, except that the undercoat layer coating liquid prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat layer coating solution] Titanium oxide (surface alumina treatment) TTO-55B (manufactured by Ishihara Sangyo) 40 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

(Comparative Example 6) A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, barium sulfate / binder resin (weight ratio) is 4.0.

[Undercoat layer coating liquid] Barium sulfate BF-10 (manufactured by Sakai Chemical Co., Ltd.) 40 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (Solid content 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Comparative Example 7 Comparative Example 6 was repeated except that the trisazo pigment of the structural formula (IV) was used in place of the crystalline oxotitanium phthalocyanine used in the coating solution for the charge generating layer prepared in Example 37. Photoconductor 1 was prepared in the same manner.

Example 38 A photoconductor 1 was prepared in the same manner as in Example 37, except that the undercoat layer coating liquid prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 2.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 20 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 39 A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 3.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 30 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 40 A photoreceptor 1 was prepared in the same manner as in Example 37, except that the undercoat layer coating liquid prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 6.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 60 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 41 A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0. The titanium oxide PT-101 used in Example 37 has an average particle size of 0.07 μm, whereas the titanium oxide CR-EL used in Example 41 has an average particle size of 0.25 μm.
m.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) CR-EL (manufactured by Ishihara Sangyo) 40 parts by weight Epoxy ester resin (solid content concentration: 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content concentration 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

Example 42 An X-ray diffraction spectrum shown in FIG. 3 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum shown in FIG. 2 used in the charge generating layer coating solution prepared in Example 37. Photoconductor 1 was prepared in the same manner as in Example 37, except that crystalline oxotitanium phthalocyanine was used.

Example 43 An X-ray diffraction spectrum shown in FIG. 4 is used in place of the crystalline oxotitanium phthalocyanine showing the X-ray diffraction spectrum shown in FIG. 2 used in the charge generating layer coating liquid prepared in Example 37. Photoconductor 1 was prepared in the same manner as in Example 37, except that crystalline oxotitanium phthalocyanine was used.

Example 44 Instead of the crystalline oxotitanium phthalocyanine used in the charge generation layer coating solution prepared in Example 37, a τ-type metal-free phthalocyanine (Liopho) was used.
Toner TPA-891 (manufactured by Toyo Ink Co., Ltd.) was used in the same manner as in Example 37 to prepare Photoconductor 1.

(Example 45) In place of the crystalline oxotitanifurphthalocyanine used in the charge generation layer coating solution prepared in Example 37, an X-ray metal-free phthalocyanine (Fastog) was used.
Photoconductor 1 was prepared in the same manner as in Example 37, except that enBlue 8120BS (manufactured by Dainippon Ink) was used.

(Example 46) Except that the thickness of the undercoat layer 3 of the photoreceptor 1 prepared in Example 37 was changed to 0.5 μm,
Photoconductor 1 was prepared in the same manner as in Example 37.

Example 47 A photoconductor 1 was produced in the same manner as in Example 37, except that the thickness of the undercoat layer 3 of the photoconductor 1 prepared in Example 37 was changed to 1 μm.

Example 48 A photoconductor 1 was prepared in the same manner as in Example 37, except that the undercoat layer coating liquid prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 40 parts by weight Polyamide CM8000 (manufactured by Toray Industries) 10 parts by weight Methanol 54 parts by weight n-butanol 36 parts by weight

Example 49 A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo Co., Ltd.) 40 parts by weight Alkyd resin (solid content concentration: 50%) M6402-50 (manufactured by Dai Nippon Ink Co., Ltd.) 16 Parts by weight Melamine resin (solid content: 60%) L117-60 (manufactured by Dainippon Ink and Chemicals) 3.3 parts by weight Methyl ethyl ketone 51 parts by weight

Example 50 A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 40 parts by weight Acrylic resin (solid content concentration: 60%) A460-60 (manufactured by Dainippon Ink) 0.5 parts by weight Melamine resin (solid content: 60%) G821-60 (manufactured by Dainippon Ink and Chemicals) 4.2 parts by weight Methyl ethyl ketone 54 parts by weight

Example 51 A photoconductor 1 was prepared in the same manner as in Example 37, except that the undercoat layer coating liquid prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) was 4.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 40 parts by weight Alkyd resin (solid content concentration 50%) M6402-50 (manufactured by Dainippon Ink and Chemicals) 12 Parts by weight Melamine resin (solid content: 60%) L117-60 (manufactured by Dainippon Ink) 3.3 parts by weight Epoxy resin (solids concentration: 70%) 1050-70X (manufactured by Dainippon Ink) 2.9 parts by weight 52 parts by weight of methyl ethyl ketone

Example 52 A photoconductor 1 was prepared in the same manner as in Example 37, except that the coating liquid for the undercoat layer prepared in Example 37 was changed as follows. In the undercoat layer coating liquid, titanium oxide / binder resin (weight ratio) is 3.8.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) PT-101 (manufactured by Ishihara Sangyo) 40 parts by weight Acrylic resin (solid content concentration: 60%) A460-60 (manufactured by Dainippon Ink) Parts by weight Melamine resin (solid content 60%) G821-60 (Dai Nippon Ink) 4.2 parts by weight Epoxy resin (solid content 70%) 1050-70X (Dai Nippon Ink) 2.9 parts by weight 54 parts by weight of methyl ethyl ketone

Example 53 A photoconductor 1 was prepared in the same manner as in Example 1 except that the undercoat layer coating liquid prepared in Example 1 was changed as follows. In the undercoat layer coating solution,
Titanium oxide / binder resin (weight ratio) is 6.0.

[Undercoat Layer Coating Solution] Titanium oxide (untreated surface) TTO-55N (manufactured by Ishihara Sangyo) 60 parts by weight Epoxy ester resin (solid content concentration 50%) P786-50 (manufactured by Dainippon Ink and Chemicals) 14 parts by weight Melamine resin (solid content 60%) L125-60 (manufactured by Dainippon Ink and Chemicals) 5 parts by weight Methyl ethyl ketone 81 parts by weight

(Evaluation 12) Table 13 shows the evaluation results of the electrostatic characteristics of the photoreceptor 1 prepared in Example 37 and Comparative Examples 5 to 7 in the same manner as in Evaluation 1 described above.

[0215]

[Table 13]

From the above results, it can be seen that a high charging potential can be obtained from the first rotation by including titanium oxide in the undercoat layer. It can be seen that when the titanium oxide filling amount is the same, the effect of the titanium oxide whose surface is untreated is greater than that of the surface-treated titanium oxide. In other words, good results can be obtained in which untreated titanium oxide can achieve the object of the present invention with a small filling amount.
As described in Evaluation 2 above, when the titanium oxide / binder resin (weight ratio) is 5.0 or more, a high charging potential is obtained from the first rotation of the surface-treated titanium oxide. . In addition, it can be seen that a photosensitive member using an azo pigment as a charge generating substance can obtain a high charging potential from the first rotation. Therefore, it is understood that the low charging potential in the first rotation is unique when phthalocyanine is used as the charge generating substance.

(Evaluation 13) Table 14 shows the results of evaluation of the electrostatic characteristics of the photoreceptors 1 prepared in Examples 37 to 40 in the same manner as in Evaluation 12.

[0218]

[Table 14]

From the above results, it was found that the titanium oxide /
It can be seen that when the binder resin (weight ratio) is 3.0 or more, a high charging potential can be obtained from the first rotation.

(Evaluation 14) With respect to the photoreceptor 1 prepared in Examples 37 and 41, the results of evaluating the electrostatic characteristics and the stability of the coating solution after standing for one day in the same manner as in Evaluation 12 are shown in Table 15. Shown in

[0221]

[Table 15]

From the above results, it can be seen that titanium oxide having an average particle size of 0.1 μm or less has a high charging potential from the first rotation and is excellent in the stability of the coating liquid.

(Evaluation 15) Table 16 shows the evaluation results of the electrostatic characteristics of the photoreceptor 1 prepared in Examples 37 and 42 to 45 in the same manner as in Evaluation 12.

[0224]

[Table 16]

From the above results, Examples 37 and 42 to 45 were obtained.
When phthalocyanine is used as a charge generating substance,
It is understood that high sensitivity and a high charging potential can be obtained from the first rotation.

(Evaluation 16) Table 17 shows the evaluation results of the electrostatic characteristics of the photoreceptor 1 prepared in Examples 37, 46, and 47 as in Evaluation 12.

[0227]

[Table 17]

From the above results, it was found that the thickness of the undercoat layer 3 was 1.
It is understood that when the thickness is 0 μm or more, a high charging potential is obtained particularly from the first rotation.

(Evaluation 17) Table 18 shows the results of evaluating the same electrostatic characteristics as in Evaluation 12 and evaluating the adhesiveness of the photoreceptor 1 prepared in Examples 37 and 48 to 52.

[0230]

[Table 18]

From the above results, it can be seen that in Examples 37 and 49 to 52 using the curable resin, a high charging potential was obtained from the first rotation, and excellent potential stability was obtained during repeated use. Example 5 in which an epoxy resin was added
Examples 1 and 52 are Examples 49 and 50 where no epoxy resin is added.
It can be seen that the adhesiveness is better than that.

(Evaluation 18) Table 19 shows the evaluation results of the electrostatic characteristics of the photoreceptor 1 prepared in Examples 1 and 53 in the same manner as in Evaluation 1 described above.

[0233]

[Table 19]

From the above results, it can be seen that when the filling amount of titanium oxide is the same, the chargeability of the untreated titanium oxide is more stable than the surface-treated titanium oxide from the beginning. . However, in the case where the surface was not treated, the degree of sedimentation was slightly larger in the coating liquid of the undercoat layer than in the case of the surface treatment, and it was found that the stability was slightly inferior. However, as described above, the stability of the coating liquid can be improved by reducing the average particle size of the titanium oxide.

[0235]

As described above, according to the present invention, an undercoat layer containing surface-treated titanium oxide and a binder resin is formed on a support, and phthalocyanine is contained on the undercoat layer. Since the photoconductive layer is formed, the charge potential in the first rotation of the photosensitive member is high with respect to long wavelength light, and the charge potential in repeated use is stabilized. Therefore, an image can be formed from the first rotation. According to the present invention, it is particularly preferable that the ratio of titanium oxide to the binder resin is in the range of 5.0 to 30.0 in terms of titanium oxide / binder resin (weight ratio). According to the present invention, it is particularly preferable that the average particle size of titanium oxide is in a range of 0.005 μm or more and 0.1 μm or less. According to the present invention,
In particular, the surface of titanium oxide is preferably subjected to any one of alumina treatment, silica treatment, and aluminum laurate treatment.

According to the present invention, an undercoat layer containing untreated titanium oxide and a binder resin is formed on a support, and a photoconductive layer containing phthalocyanine is formed on the undercoat layer. The same effect can be obtained by forming. According to the invention, it is particularly preferable that the ratio of titanium oxide to the binder resin in the undercoat layer is in the range of 3.0 to 30.0 by titanium oxide / binder resin (weight ratio). .
According to the present invention, it is particularly preferable that the average particle size of titanium oxide is in a range of 0.005 μm or more and 0.1 μm or less.

According to the present invention, an undercoat layer containing surface-treated zinc oxide and a binder resin is formed on a support, and a photoconductive layer containing phthalocyanine is formed on the undercoat layer. The same effect can be obtained by forming. According to the present invention, particularly, as the surface treatment of zinc oxide, alumina treatment or silica treatment is preferable.

Further, according to the present invention, an undercoat layer containing untreated surface zinc oxide and a binder resin is formed on a support, and a phthalocyanine-containing photoconductive layer on the undercoat layer is formed on the undercoat layer. The same effect can be obtained by forming.

According to the present invention, it is particularly preferable to select the weight ratio of the surface-treated or surface-untreated zinc oxide to the binder resin in the range of 1.5 to 30.0.

According to the present invention, phthalocyanine is
(A) In the X-ray diffraction spectrum, the Bragg angle (2θ
± 0.2 °) 7.3 °, 9.4 °, 9.6 °, 11.6
°, 13.3 °, 17.9 °, 24.1 ° and 27.
A major peak is shown at 2 °, the overlapping peak bundle of 9.4 ° and 9.6 ° shows the highest peak intensity, and 27.
Crystalline oxotitanium phthalocyanine having a peak at 2 ° showing the second peak intensity. (B) In X-ray diffraction spectrum, Bragg angle (2θ ± 0.2 °) 9.5 °, 9.
7 °, 11.7 °, 15.0 °, 23.5 °, 24.1
Crystalline oxotitanium phthalocyanine showing major peaks at 0 ° and 27.3 °. (C) In X-ray diffraction spectrum, Bragg angle (2θ ± 0.2 °) 9.0 °, 1
Crystalline oxotitanium phthalocyanine showing major peaks at 4.2 °, 23.9 ° and 27.1 °, (d)
It is preferable to use one or a mixture of two or more of the τ-type metal-free phthalocyanine and (e) the X-type metal-free phthalocyanine.

Further, according to the present invention, the thickness of the undercoat layer is set to 1
It is preferable to select the size within a range of not less than μm and not more than 10 μm.

According to the present invention, it is preferable to use a curable resin as the binder resin of the undercoat layer. According to the invention, as the curable resin, (a) a mixture of an alkyd resin and a melamine resin, (b) a mixture of an acrylic resin and a melamine resin, (c) a mixture of an epoxy ester resin and a melamine resin, (d) It is particularly preferable to use one of a mixture of an alkyd resin, a melamine resin, and an epoxy resin, and (e) a mixture of an acrylic resin, a melamine resin, and an epoxy resin.

According to the present invention, in an image forming method for forming an image by rotating an electrophotographic photosensitive member, an image can be formed at a high speed by using the photosensitive member for image formation from the first rotation. It can be formed.

[Brief description of the drawings]

FIG. 1 is an electrophotographic photoreceptor 1 according to an embodiment of the present invention.
FIG.

FIG. 2 is a graph showing an X-ray diffraction spectrum of crystalline oxotitanyl phthalocyanine.

FIG. 3. X of other crystalline oxotitanyl phthalocyanine
It is a graph which shows a line diffraction spectrum.

FIG. 4 is a graph showing an X-ray diffraction spectrum of still another crystalline oxotitanyl phthalocyanine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photoreceptor 2 conductive support 3 undercoat layer 4 photoconductive layer 5 charge generation layer 6 charge transport layer

Continued on the front page F term (reference) 2H035 CA07 CB01 2H068 AA19 AA43 AA44 AA45 AA48 BA37 BA38 BB07 BB23 BB30 BB37 BB57 CA22 CA29

Claims (16)

[Claims] 1. An electrophotographic photoreceptor that is used repeatedly, wherein at least an undercoat layer and a photoconductive layer are formed on a conductive support, wherein the undercoat layer binds at least to a surface-treated titanium oxide. An electrophotographic photoreceptor comprising a resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance. 2. The method according to claim 1, wherein the ratio of titanium oxide to the binder resin in the undercoat layer is in the range of 5.0 to 30.0 by weight of titanium oxide / binder resin. Item 1
The electrophotographic photosensitive member according to the above. 3. The titanium oxide has an average particle size of 0.005.
3. The electrophotographic photosensitive member according to claim 1, wherein the thickness is in a range of not less than μm and not more than 0.1 μm. 4. The method according to claim 1, wherein the surface treatment applied to the titanium oxide is any one of an alumina treatment, a silica treatment and an aluminum laurate treatment. The electrophotographic photosensitive member according to the above. 5. An electrophotographic photoreceptor, wherein at least an undercoat layer and a photoconductive layer are formed on a conductive support, wherein the undercoat layer has at least a surface bonded to untreated titanium oxide. An electrophotographic photoreceptor, comprising: a resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance. 6. The method according to claim 1, wherein the ratio of titanium oxide to the binder resin in the undercoat layer is in a range of 3.0 to 30.0 by weight of titanium oxide / binder resin. Item 5
The electrophotographic photosensitive member according to the above. 7. The titanium oxide has an average particle size of 0.005.
The electrophotographic photoreceptor according to claim 5, wherein the thickness is in a range of not less than μm and not more than 0.1 μm. 8. An electrophotographic photoreceptor that is used repeatedly in which at least an undercoat layer and a photosensitive layer are formed on a conductive support, wherein the undercoat layer comprises at least surface-treated zinc oxide and a binder resin. Wherein the photoconductive layer contains phthalocyanine as a charge generating substance. 9. The electrophotographic photoconductor according to claim 8, wherein the surface treatment applied to the zinc oxide is an alumina treatment or a silica treatment. 10. An electrophotographic photoreceptor that is used repeatedly in which at least an undercoat layer and a photosensitive layer are formed on a conductive support, wherein the undercoat layer has at least a surface bound to untreated zinc oxide. An electrophotographic photosensitive member comprising a resin, wherein the photoconductive layer contains phthalocyanine as a charge generating substance. 11. The zinc oxide / binder resin ratio in the undercoat layer in the range of 1.5 to 30.0 (weight ratio) of zinc oxide / binder resin. Item 11. The electrophotographic photosensitive member according to Item 8 or 10. 12. The phthalocyanine according to (a), in the X-ray diffraction spectrum, a Bragg angle (2θ ± 0.2 °)
7.3 °, 9.4 °, 9.6 °, 11.6 °, 13.3
°, 17.9 °, 24.1 ° and 27.2 ° show major peaks, the overlapping peak bundle of 9.4 ° and 9.6 ° shows the maximum peak intensity, and 27.2 °. The crystalline oxotitanium phthalocyanine shows a second peak intensity at the peak of °. (B) In X-ray diffraction spectrum, Bragg angles (2θ ± 0.2 °) 9.5 °, 9.7 °, 11.
7 °, 15.0 °, 23.5 °, 24.1 ° and 2
Crystalline oxotitanium phthalocyanine showing a major peak at 7.3 °, (c) in X-ray diffraction spectrum,
Bragg angles (2θ ± 0.2 °) 9.0 °, 14.2 °,
One or more of crystalline oxotitanium phthalocyanine, (d) τ-type metal-free phthalocyanine and (e) X-type metal-free phthalocyanine exhibiting main peaks at 23.9 ° and 27.1 ° 11. The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is a mixture. 13. The undercoat layer has a thickness of 1 μm or more and 10 μm or more.
The range of not more than μm.
11. The electrophotographic photosensitive member according to 8 or 10. 14. The electrophotographic photosensitive member according to claim 1, wherein the binder resin of the undercoat layer is a curable resin. 15. The curable resin includes: (a) a mixture of an alkyd resin and a melamine resin, (b) a mixture of an acrylic resin and a melamine resin, (c) a mixture of an epoxy ester resin and a melamine resin, (d) an alkyd. 15. The electrophotographic photoreceptor according to claim 14, wherein the electrophotographic photoreceptor is any one of a mixture of a resin, a melamine resin and an epoxy resin, and (e) a mixture of an acrylic resin, a melamine resin and an epoxy resin. 16. An image forming method for forming an image by rotating an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member according to claim 1 is used as the electrophotographic photosensitive member. An image forming method, wherein the body is used for image formation from the first rotation.