JPS63286857A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To retain the intrinsic characteristics of X-type metal-free phthalocyanine and to improve only its humidity dependency by incorporating the metal-free phthalocyanine made of mixed crystals of beta-type and X-type exhibiting intense diffraction lines at specified Bragg angles as an electric charge generating material in a photosensitive layer. CONSTITUTION:The photosensitive layer contains as the charge generating material the metal-free phthalocyanine composed of the mixed crystals of beta-type and X-type exhibiting intense diffraction lines of Bragg angles (2theta+ or -0.2 deg.) of 6.9 deg., 7.5 deg., 8.9 deg., 9.1 deg., 15.3 deg., 16.7 deg., 17.3 deg., 17.9 deg., and 20.4 deg.. Said metal-free phthalocyanine composed of the mixed crystals of beta-type and X-type is formed by heat treating alpha- or X-type metal-free phthalocyanine in N-methyl-2- pyrrolidone or monochlorobenzene for 1-5hr in a state of suspension, thus permitting the obtained photosensitive body to be reduced in humidity dependency, and to form an image superior in image quality without causing fog and white spots even under high humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive support. It is.

BACKGROUND OF THE INVENTION Conventionally, functionally separated electrophotographic photoreceptors having a charge generation layer and a charge transport layer have been proposed, and the charge generation layer is generally made by dispersing photoconductive pigment particles in a binder resin. It is made up of layers. Many materials have been proposed for these pigment particles, and various metal-free phthalocyanines have also been proposed (for example, those belonging to type
183757M, No. 58-1837588, No. 60-
See Publication No. 20969>. Among them, special public service 1410-1973.
As shown in Publication No. 6@, the X-type metal-free phthalocyanine exhibits excellent properties. That is, it has good dispersibility in the binder resin and also exhibits good electrical properties in terms of electrophotographic properties.

Problems to be Solved by the Invention However, X-type metal-free phthalocyanine is highly dependent on humidity, and in a photoreceptor using X-type metal-free phthalocyanine as a charge-generating material, charge injection from the substrate under high humidity is difficult. This tends to cause image quality defects such as fog in a reversal development system and minute white spots in a normal development system. In addition, in photoreceptors using β-type metal-free phthalocyanine as a charge-generating material, the dark decay is small and the humidity dependence is small, but the spectral absorption is shifted to the shorter wavelength side compared to the X-type, so it is not a semiconductor. As a photoreceptor for a laser printer, it has low sensitivity in the range of 780 to 830 nm, and has the disadvantage of poor dispersion in a binder resin compared to type X.

The present invention aims to solve the above-mentioned problems in the conventional technology. That is, it was made for the purpose of improving only the humidity dependence while making full use of the excellent properties such as dispersibility, coating properties, and spectral sensitivity originally possessed by the X-type metal-free phthalocyanine.

Means for Solving the Problems The above-mentioned object of the present invention is to solve the problems by treating α-type or X-type metal-free phthalocyanine with a specific solvent such as N-methylpyrrolidone or monochlorobenzene. This can be achieved by using a metal-free phthalocyanine consisting of a mixed crystal of.

That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the photosensitive layer is a charge-generating material and has a Bragg angle (2θ±0.2°) of 6.9.7.5. ．．
8.9.9.1.15.3.16.7.17.3.17
．． It is characterized by containing a metal-free phthalocyanine consisting of a β-type and an X-type mixed crystal that exhibits a strong diffraction line at 9.20.4°.

The present invention will be explained in more detail below.

In the present invention, the photosensitive layer formed on the conductive support may have a single-layer structure containing a charge-generating material and a charge-transporting material. Preferably.

FIGS. 2 to 5 are schematic cross-sectional views when the electrophotographic photoreceptor of the present invention has a laminated structure.

In FIG. 2, a charge generation layer 1 and a charge transport layer 2 are sequentially provided on a conductive support 3. In FIG. 3, an undercoat layer 4 is provided between the conductive support 3 and the charge generation layer 1. In FIG. 4, a protective layer 5 is provided on the surface of the charge transport layer 3, and in FIG. 5, a subbing layer 4 is provided between the conductive support 3 and the charge generation image 1. A protective layer 5 is provided on the surface of the charge transport layer 2 .

Next, each layer constituting the electrophotographic photoreceptor of the present invention will be explained.

The electroconductive support in the electrophotographic photoreceptor of the present invention includes a drum made of metal such as aluminum, copper, iron, zinc, and nickel, and a drum made of metal such as aluminum, copper, gold, and silver on a sheet, paper, plastic, or glass. , depositing metals such as platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium, depositing conductive metal compounds such as indium oxide, tin oxide, laminating metal foil, or carbon. Black, indium oxide, tin oxide
Sea! is a drum-shaped drum-shaped conductive treatment made by dispersing and coating antimony oxide powder, metal powder, etc. in a binder resin.・Well-known materials such as a plate-like material can be used, but the material is not limited thereto.

Further, if necessary, the surface of the conductive support can be subjected to various treatments as long as the image quality is not affected. For example, the surface can be subjected to oxidation treatment, chemical treatment, coloring treatment, etc.

Further, an undercoat layer may be further provided between the conductive support and the charge generation layer. This undercoat layer is an adhesive layer that prevents the injection of charge from the conductive support to the photosensitive layer when the photosensitive layer having a laminated structure is charged, and also holds the photosensitive layer integrally adhered to the conductive support. or, in some cases, the effect of preventing light from being reflected from the conductive support.

The binder resin used for this undercoat layer is polyethylene, polypropylene, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate, polyurethane, polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, chloride resin, etc. Vinyl-vinyl acetate copolymer, polyvinyl alcohol, water-soluble polyester, nitrocellulose, casein,
Known resins such as gelatin can be used, and the thickness of the undercoat layer is 0.01 to 10 μm, preferably 0.05 μm.
~2μ is appropriate. Furthermore, the coating methods used when providing this undercoat layer include blade coating method,
Conventional methods such as Mayer bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating can be used.

As a charge generating material to be included in the photosensitive layer or charge generating layer,
In the present invention, a metal-free phthalocyanine consisting of the β-type and X-type mixed crystal is used, and this material has a Bragg angle (2θ±0.2°) of 6.9.7.5.8.9. 9,
1.15.3.1687.17.3.17.9.20.
It is characterized by a strong diffraction line at 4°, which is different from that of conventionally known metal-free phthalocyanines (see Figure 1). Therefore, the metal-free phthalocyanine used in the present invention is considered to have a polymorphic structure consisting of a mixed crystal of β type and X type.

The metal-free phthalocyanine consisting of a mixed crystal of β-type and X-type used in the present invention is a metal-free phthalocyanine of α-type or It can be obtained by thermal suspension treatment in monochlorobenzene for 1 to 5 hours.

When the electrophotographic photoreceptor of the present invention has a laminated structure, examples of the binder resin of the charge generation layer include polystyrene resin, polyvinyl acetal resin, acrylic resin, methacrylic resin, vinyl acetate resin, polyester resin, polyarylate resin, Known materials such as polycarbonate resin and phenol resin can be used alone or in combination, but are not limited to these. Among these materials, polyvinyl acetal resin is particularly desirable because of its excellent pigment particle dispersibility and electrical properties in electrophotographic properties.

More specifically, it is desirable to use polyvinyl butyral resin, polyvinyl formal resin, and partially acetalized polyvinyl butyral resin alone or in combination of two or more.

The blending ratio (weight) of the metal-free phthalocyanine and the binder resin is preferably in the range of 10:1 to 1:10.

As a method for dispersing the metal-free phthalocyanine in the binder resin, a conventional method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, etc. can be used. Conditions are required in which the form of the phthalocyanine does not change. Incidentally, in any of the above dispersion methods implemented in the present invention, it has been confirmed that the crystal form does not change from before dispersion.

Furthermore, during this dispersion, the particle size is 5 μm or less, preferably 2 μm or less.
It is effective to make the particle size less than μm, more preferably less than 0.5 μm.

In addition, the solvents used for these dispersions include methanol,
Ethanol, n-propertool, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone,
Common organic solvents such as methyl acetate, dioxane, tetrahydrofuran, methylene chloride, and chloroform can be used alone or in combination of two or more.

Further, the thickness of the charge generation layer used in the present invention is generally 0.
A suitable range is 1 to 5 μm, preferably 0.2 to 2.0 Ii7W. Further, as the coating method used when providing the charge generation layer, usual methods such as blade coating method, Meyer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. can be used. Can be used. The charge transport layer in the electrophotographic photoreceptor of the present invention is formed by containing a charge transport material in a suitable binder. As a charge transport material, 2.5
-bis(p-diethylaminophenyl)-1,3,4-
Oxadiazole derivatives such as oxadiazole, 1.3
．． 5-triphenyl-pyrazoline, 1-[pyridyl-(
2)]-3-(p-diethylaminostyryl)-'5-
Pyrazoline derivatives such as (p-diethylaminophenyl)pyrazoline, aromatic tertiary amino compounds such as triphenylamine and dibenzylaniline, N,N'-diphenyl-N,N'-bis-(3-methylphenyl)- [1,
Aromatic tertiary diamino compounds such as 1'-biphenyl]-4,4'-diamine, 3-(4'-dimethylaminophenyl)-5,6-di(4'-methoxyphenyl)
-1,2,4-triazine derivatives such as -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1
'-'Hydrazone derivatives such as diphenylhydrazone, 2
-quinazoline derivatives such as phenyl-4-styrylquinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di(p-methoxyphenyl)benzofuran, p-(2
,2-diphenylvinyl)-N,N-diphenylaniline and other α-stilbene derivatives, “JOUrnal of
Imaging 5science” 29: 7~
10 (1985), an enamine derivative, N
- poly-N-vinylcarbazole and its derivatives such as ethylcarbazole, poly-γ-carbazole ethylglutamate and its derivatives, as well as pyrene, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-biphenylanthracene, pyrene-formaldehyde resin, Known charge transport materials such as, but not limited to, ethyl carbazole-formaldehyde resin can be used. Further, these charge transport materials can be used alone or in combination of two or more.

The binder resin used for the charge transport layer is polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin,
Polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd Known resins such as resin, phenol-formaldehyde resin, styrene-alkyd resin, and poly-N-vinylcarbazole can be used, but are not limited thereto. Further, these binder resins can be used alone or in combination of two or more.

The blending ratio (weight ratio) of the charge transport material and the binder resin is 10:
A range of 1 to 1:5 is preferred. The thickness of the charge transport layer used in the present invention is generally 5 to 50 μm, preferably 1 μm.
A suitable thickness is 0 to 30 μm. As a coating method, conventional methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method can be used.

Solvents used when providing a charge transport layer on the surface include:
Aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenpine, ketones such as acetone and 2-butanone, halogenated aliphatic hydrocarbons such as styrene chloride, chloroform, and ethylene chloride, detrahydrofuran, and ethyl ether. Common organic solvents such as cyclic or linear ethers can be used alone or in combination of two or more.

A protective layer may be provided on the charge transport layer if necessary. This protective layer is used to prevent chemical deterioration of the charge transport layer when the photosensitive layer having a laminated structure is charged, and to improve the mechanical strength of the photosensitive layer.

This protective layer is formed by incorporating a conductive material in a suitable binder. Examples of conductive materials include metallocene compounds such as N,N'-dimethylferrocene, N,N'-diphenyl=N,N'-bis(3-methylphenyl)-
Use materials such as aromatic amine compounds such as [1,1'-biphenyl]-4,4'-diamine, metal oxides such as antimony oxide, tin oxide, titanium oxide, indium oxide, and tin oxide-antimony oxide. Can be done. As the binder resin used for this protective layer, known resins such as polyamide resin, polyurethane, polyester resin, epoxy resin, polyketone resin, polycarbonate, polyvinyl ketone resin, polystyrene, polyacrylamide resin, etc. can be used.

In addition, this protective layer has an electrical resistance of 109 to 1014 Ω.
It is preferable to configure it so that it becomes cm.

If the electrical resistance exceeds 1014Ω・cm, the residual potential will increase and the resulting copies will have a lot of fog.
・When the distance is less than cm, the image becomes blurred and the resolution decreases. The protective layer must also be constructed so as not to substantially block the passage of light used for imagewise exposure.

The thickness of the protective layer used in the present invention is suitably 0.5 to 20 μm, preferably 1 to 10 μm. As for the canvas method,
Conventional methods such as blade coating, Meyer bar coating, spray coating, dip coating, bead coating, air knife coating, curtain coating, etc. can be used.

Example Hereinafter, the present invention will be explained by examples.

Example 1 X-type metal-free phthalocyanine (manufactured by Xerox Corporation, USA) 30
g with 500 ml of N-methyl-2-pyrrolidone
Thermal suspension treatment was carried out for 1 hour at a temperature of 0°C. Next, washing with methanol was repeated several times and drying to obtain metal-free phthalocyanine 289 in the form of blue powder. The X-ray diffraction pattern of this gold-free phthalocyanin is shown in FIG. Incidentally, an X-ray diffraction diagram of the X-type metal-free phthalocyanine as a raw material is shown in FIG. Using the thus obtained metal-free phthalocyanine, a charge generation layer forming liquid having the following composition was prepared.

Said metal-free phthalocyanine? . 59 Partially formalized polyvinyl 2.59 Butyral resin (
Sekisui Chemical! a13X-2) Cyclohexanone
After milling for 30 hours using a 1/8 inch φ SUS ball as a mill member, the mixture consisting of 45.09 was placed in a ball mill pot, and then 50 g of cyclohexanone was added to the colander, diluted, and stirred to form a charge generating layer. A dispersion was prepared. This charge generation layer forming liquid was applied by dip coating onto the aluminum substrate to form a charge generation layer having a thickness of 0.3 μm after drying. Furthermore, it was confirmed by X-ray diffraction that the crystal form of the metal-free phthalocyanine after dispersion did not change compared to the crystal form before dispersion.

Next, a charge transport layer forming liquid having the following composition was applied by dip coating onto the charge generation layer to form a charge transport layer having a thickness of 20 μm after drying, which consisted of a conductive support, a charge generation layer, and a charge transport layer. A laminated electrophotographic photoreceptor was manufactured.

4-Diethylaminobenzaldehyde 89-1.1'
-Diphenylhydrazone polycarbonate resin
129 (Hitsuiryu Kasei Co., Ltd. -1300> Methylene chloride 809 The thus obtained photoreceptor was tested using an electrostatic copying paper tester (Kawaguchi Electric: Electrostatic Analyzer EPA-
8100> at room temperature and humidity (25°C, 40% R1-
The following measurements were carried out under the environment of 1>.

VDOP: −6, OKV corona discharge is performed to negatively charge the surface potential after 1 second, E1/2: Spectral sensitivity at 800 nm using a bandpass filter (
RP: Surface potential after irradiation with white light of 50 erg/ci for 0.5 seconds. The obtained characteristic values were as follows.

Normal temperature and humidity (25°C 140%RH) VDDP: -815V El/2: 16.60mMcrtRP knee 70
V Similar measurements were also conducted under a high temperature and high humidity environment (30° C., 80% RH), and the following characteristic values were obtained.

High temperature and high humidity (30°C, 80% RH) VDDP Knee 805 V E1/2: 18.3 erMci RP Knee 80V As is clear from these results, the above photoreceptor has excellent charging properties and excellent charging properties even under high temperature and high humidity conditions. Shows sensitivity.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1, except that X-type metal-free phthalocyanine (manufactured by Xerox Corporation) was used instead of the metal-free phthalocyanine in the charge generation layer in Example 1, and the same measurements were performed. As a result, we obtained the following characteristic values. The X-type metal-free phthalocyanine used here was published in Japanese Patent Publication No. 44-1410.
It was prepared according to the method described in Publication No. 6,
The X-ray diffraction diagram is shown in FIG. Furthermore, it was confirmed by X-ray diffraction that the crystal form of the X-type metal-free phthalocyanine after dispersion did not change compared to the crystal form before dispersion.

Normal temperature and humidity (25°C, 40%RH) VDDP: -810V El/2:14.5er(]/Cn RP knee 60V Similar measurements were conducted in a high temperature and high humidity environment (30'C, 180%RH), The following characteristic values were obtained.

High temperature and high humidity (30°C, 80% RH) VDDP: -680V E 1/2: 21.88m (J/crrtRP knee 90V) As is clear from these results, the photoreceptor using type X metal-free phthalocyanine is Chargeability and sensitivity are reduced under high humidity.

Comparative Example 2 In place of the metal-free phthalocyanine in the charge generation layer in Example 1, β-type metal-free phthalocyanine was used. A photoreceptor was produced in the same manner as in Example 1 except for this, and the same measurements were performed, and the following characteristic values were obtained.

The β-type metal-free phthalocyanine used here was obtained by heat treating X-type metal-free phthalocyanine (manufactured by Xerox Corporation) at a temperature of 320°C for 1 hour, and its X-ray diffraction pattern is shown in Figure 6. . Furthermore, it was confirmed by X-ray diffraction that the crystal form of the β-type metal-free phthalocyanine after dispersion did not change compared to the crystal form before dispersion.

Normal temperature and humidity (25℃, 40%RH> VDDP knee 820V El/2: 32.5 erVcd RP knee 100V Similar measurements were performed in a high temperature and high humidity environment (30℃, 80%RH), and the following Characteristic values were obtained.

High temperature and high humidity (30°C, 80% RH) V[)[)P: -815V E 1/2: 33.7 erQ/c! Although the photoreceptor using RP Knee 110V β-type metal-free phthalocyanine does not deteriorate in chargeability or sensitivity under high temperature and high humidity, the absolute value of sensitivity at aoonm is lower than that of the X-type metal-free phthalocyanine. It was low.

Example 2 30 g of X-type metal-free phthalocyanine (manufactured by Xerox Corporation) was kept in the dark and thermally suspended in 500 d of benzene at a temperature of 6100° C. for 2 hours. Next, washing with methanol was repeated several times and drying yielded 1 q of metal-free phthalocyanine 279 in the form of blue powder.

As a result of X-ray diffraction, this metal-free phthalocyanine was found in Example 1.
It was confirmed that there was a strong diffraction line at the same position as the metal-free phthalocyanine with β-type and X-type mixed crystal forms obtained in . Using the thus obtained metal-free phthalocyanine, a charge generation layer forming liquid having the following composition was prepared.

A mixture consisting of the metal-free phthalocyanine 2.03 partially acetoacetalized 3.0 g polyvinyl butyral resin (Sekisui Chemical BX-1 > cyclohexanone 45.0!?) was placed in a sand mill pot and milled as a mill member.
After milling for 20 hours using mφ glass beads, cyclohexanone 509 was further added, diluted, and stirred to prepare a dispersion for forming a charge generation layer. This charge generation layer forming liquid was dip coated onto the aluminum base material, and the thickness after drying was 0.
．． A charge generation layer of 5 μm was provided.

Next, a charge transport layer having a thickness of 20 μm was formed in the same manner as in Example 1 using a charge transport layer forming liquid having the following composition.

α-Stilbene compound 10 and polycarbonate resin 109 (K-
1300) Methylene chloride 80 g The photoreceptor thus obtained was subjected to the same measurements as in Example 1, and the following characteristic values were obtained.

Normal temperature and humidity (25°C, 140% RH) VD[)P: -aio v E 1/2: 17. OerQ/crARP knee 8
5V Similar measurements were also carried out in an environment of high temperature and high humidity (30° C., 80% RH) to obtain the following characteristic values.

High temperature and high humidity (30℃, 80%RH> VD[)P: -805V E 1/2: 18.6 erg/cnRP knee 80
V As is clear from this result, this photoreceptor also
It shows excellent chargeability and sensitivity even under high temperature and high humidity conditions.

Example 3 A drum-type photoreceptor was produced under the same conditions as Example 1, and this photoreceptor was installed in a semiconductor laser printer (reversal development system) to copy images at high temperature and high humidity (30°C, 80% RH). When formed, a clear image with high contrast and good reproducibility was obtained.

Although copying was repeated 10,000 times, images with the same quality as the first copy were obtained until the end.

Example 4 A drum-type photoreceptor was produced under the same conditions as Example 2, and this photoreceptor was measured in the same manner as Example 3.
Similarly, clear images with high contrast and good reproducibility were obtained.

Comparative Example 3 A drum-type photoreceptor was produced under the same conditions as Comparative Example 1, and when this photoreceptor was measured in the same manner as in Example 3, the image showed low contrast, fog, and structural lines. Oops. Also, after about the 100th use, the fogging became more severe, and it was found that there were considerable problems with the image quality under high temperature and high humidity conditions.

Example 5 30 g of α-type metal-free phthalocyanine (manufactured by Xerox Corporation) was thermally suspended in 500 m of N-methyl-2-pyrrolidone at a temperature of 150° C. for 1 hour. Next, washing with methanol was repeated several times and drying to obtain metal-free phthalocyanine 27 in the form of blue powder. As a result of X-ray diffraction, this metal-free phthalocyanine was found to be 1q in Example 1.
It was confirmed that a strong diffraction line was observed at the same position as the metal-free phthalocyanine with mixed crystal forms of β type and X type.

A photoreceptor similar to that of Example 1 was prepared except that the metal-free phthalocyanine thus obtained was used, and the same measurements were performed, and the following characteristic values were found to be 1i.

Normal temperature and humidity (25℃, 40%RH) VDDP: -810V El/2: 1B, 3 erg/c171RPV-
65V Similar measurements were also conducted in a high temperature and high humidity environment (30° C., 80% RH), and the following characteristic values were obtained.

High temperature and high humidity (30°C, 80% RH) V[)[)P: -805V E 1/2: 18. Oerg/cfflRP knee 7
5V As is clear from the results, this photoreceptor also exhibits excellent charging properties and sensitivity under high temperature and high humidity conditions, as in Example 1.

Effects of the Invention As described above, the electrophotographic photoreceptor of the present invention uses metal-free phthalocyanine consisting of a β-type and It is small and forms images of excellent quality without fogging or white spots even under high humidity conditions.

Also, 780~. Since the sensitivity at 830 nm is also high, it can also be used as a photoreceptor for semiconductor laser printers and the like.

[Brief explanation of drawings]

FIG. 1 is an X-ray diffraction diagram of metal-free phthalocyanine mixed crystal of β type and FIG. 6 and FIG. 7 are X-ray diffraction diagrams of β-type metal-free phthalocyanine and X-type metal-free phthalocyanine, respectively. DESCRIPTION OF SYMBOLS 1... Charge generation layer, 2... Charge transport layer, 3... Conductive support, 4... Undercoat layer, 5... Protective layer. 1C45202E, 30 2θgθ: Cross-needle angle Figure 1 "QJI-Dimension of -...Dimension of 0 U] 5 10 is 20
25 302θ (θ: angle of rotation 5 1o j5 2
0 25 302θ (θ:: Attention) Procedural amendment (voluntary) October 30, 1985 Director General of the Patent Office Kunio Ogawa Address 3-3-5 Akasaka, Minato-ku, Tokyo @Name (
549) Fuji Xerox Co., Ltd. Representative Yota Kobayashi 6 Contents of amendment (1) “16.6 erg/ci” on page 19, line 1 of the specification letter
Correct J to "6. Ierg/ci J. 2 Correct "1B, 3erg/cd" on page 19, line 7 of the same
Correct to 6.7erg/crd J. 3> “14.5erMrnJ” on page 20, line 6 of the same page is “5
．． 7elcl/crtt”. (4) “21.8erg/CI/
Correct lJ to "8°9erg/ ctil J. (5) r 32.5er(]/ on page 21, line 11 of the same)
cd" to "r25.1erg/cd".゛<61 "33.7erg/7J on page 21, line 17 of the same page is corrected to r26.7erg/cgtJ. (7) 117.0er(J/rff
Correct lJ to r6.2erq/cttt. 8) [1B, 6erCl/cffl, page 24, line 8]
Correct J to r 6.7erq/cti J. (9) “1B, 3erg/ctrt” on page 26, line 8.
J to r 6. Correct to Oerg/crA J. (10) “18.Oerg/C/
rr” to “6.5erg/ci J.”

Claims (5)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer serves as a charge generating material and has a Bragg angle (2θ±0.2°) of 6.9, 7.5, 8. 9, 9
．． 1, 15.3, 16.7, 17.3, 17.9, 20
．． An electrophotographic photoreceptor characterized by containing a metal-free phthalocyanine consisting of β-type and X-type mixed crystals exhibiting a strong diffraction line at 4°. (2) The metal-free phthalocyanine is produced by heat suspension treatment of α-type or X-type metal-free phthalocyanine in N-methyl-2-pyrrolidone at 60°C to 160°C for 1 to 5 hours. An electrophotographic photoreceptor according to claim 1. (3) The metal-free phthalocyanine is produced by thermally suspending α-type or X-type metal-free phthalocyanine in monochlorobenzene at 60°C to 160°C for 1 to 5 hours. The electrophotographic photoreceptor according to item 1. (4) The electrophotographic photoreceptor according to claim 1, wherein a charge generation layer containing the metal-free phthalocyanine and a charge transport layer are laminated on a conductive support. (5) The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer contains a polyvinyl acetal resin as a binder resin.