JP3208169B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor in which a specific crystalline oxytitanium phthalocyanine film is used as a charge generation layer in an electrophotographic photoreceptor, and is particularly characterized by a novel method for forming the film.

[0002]

2. Description of the Related Art Recently, a semiconductor laser mainly used has an oscillation wavelength of 790 ± 20 nm, which is a near-infrared wavelength. Therefore, a photoreceptor for electrophotography having sufficient sensitivity to such long wavelength light has been developed. Has been advanced.

[0003] Materials satisfying this requirement include phthalocyanine pigments, polyazo pigments, beryllium pigments, and naphthoquimethine pigments. Among phthalocyanine-based pigments, much research has been conducted on metal phthalocyanine compounds. Among them, oxytitanium phthalocyanines having different crystal systems have been reported. In each of the crystal systems, oxytitanium phthalocyanine having a strong peak at a black angle of 27.3 ° in the CuKα X-ray diffraction spectrum shows high sensitivity, has this crystallinity in a powder state, and is a solvent which does not change the crystal system. Some are being dispersed. Further, a system in which the above-mentioned crystal system is converted from a non-crystalline state with cyclohexanone is disclosed in
362.

[0004] However, a photosensitive layer formed by these methods is a GaAlAs semiconductor laser 790 ±.
The half decay exposure amount E _^1/2 in 20nm light sources 0.2MyuJ /
cm ² is the limit.

[0005]

In recent years, laser printers have been developed for higher speed and lower cost, and higher sensitivity of an electrophotographic photosensitive member provided therein has been regarded as more important than ever. The present invention realizes high sensitivity in a specific manufacturing method to be compatible with these high-speed printers and low-cost lasers.

[0006]

Means for Solving the Problems The present inventors have found that in the X-ray diffraction spectrum, the black angle (2θ ± 0.2 °) 2
As a result of studying a method for producing an effective charge generation layer of a crystal system having a main diffraction peak at 7.3 °, a main diffraction at an X-ray diffraction black angle (2θ ± 0.2 °) of 26.2 ° was obtained as a charge generation material. After using a powdered oxytitanium phthalocyanine having a peak and treating it once in an amorphous state, using a wet milling with an alcohol-based solvent containing a binder, a crystal system having a main diffraction peak around 27.3 ° in the X-ray diffraction peak is obtained. the solvent of good dispersibility ketone was added to the dispersion after changing, by a method of coating formed, the half decay exposure E _^1/2 is the invention to realize an electrophotographic photoreceptor showing the 0.15μJ / cm ² or less sensitivity Was completed.

[0007] That is, the present invention provides a method for manufacturing a semiconductor device, comprising the steps of:
An electrophotographic photoconductor comprising a charge generation layer and a charge transfer layer containing an oxytitanium phthalocyanine crystal,
The oxytitanium phthalocyanine photosensitive layer is CuKα
Black angle in X-ray diffraction spectrum (2θ ± 0.
2 °) Powdered oxytitanium phthalocyanine showing a main clear diffraction peak at 26.2 ° is vacuum-deposited, acid-pasted or mechanically non-crystallized, milled with an alcohol-based solvent containing a binder, and X-ray diffraction. Black angle of spectrum (2θ ± 0.2 °) 27.
The crystalline oxytitanium phthalocyanine, which shows a main clear diffraction peak at 3 °, is formed by applying a dispersion solution containing a ketone-based solvent that does not change the crystal system. Things.

Hereinafter, the present invention will be described in detail. As shown in FIG. 1 described later, a charge generation layer (2) is formed on a conductive support (1), and a charge transfer layer 3 is further formed on the layer. In the photoconductor for organic electrophotography described above, the conductive support (3) may be a metal such as aluminum or stainless steel, or a plastic or paper provided with a conductive layer. Is raised.

An optimal method for forming the charge generation layer will be described below. First, a powder material manufactured by Permachem Asia, which shows a main diffraction peak at a black angle (2θ ± 0.2 °) of 26.2 ° in the X-ray diffraction spectrum of CuKα, is made amorphous by using a ball mill, a sand mill, a paint shaker. Dry pulverization, acid pasting, vacuum evaporation recovery, and the like.

The amorphous powder thus obtained is used as a binder in an alcoholic solvent typified by, for example, methanol as Sekisui Chemical (ESLEK BL-1, BM-1, BH-
3)), and wet milling with a ball mill, paint shaker, etc., and the black angle (2θ ±) of the X-ray diffraction spectrum.
(0.2 °) is changed to a crystal system showing a main peak at 27.3 °. The CuKα X-ray diffraction spectrum of the pellet formed after the wet milling is shown in FIG. 2 described later.

Next, a ketone-based solvent such as cyclohexanone or methyl ethyl ketone is added, and the mixture is dispersed by a ball mill, a paint shaker or the like. The coating liquid thus obtained is applied and dried to form the charge generation layer (2). The ratio of oxytitanium phthalocyanine to binder polymer is not particularly limited, but a binder polymer of 20 to 300 parts by weight per 100 parts by weight of oxytitanium phthalocyanine is preferred. The thickness of the charge generation layer is preferably about 0.1 to 3 μm.

The charge transfer layer 3 is made of a material exhibiting a high carrier transfer medium. The transfer agent is preferably a hydrazone compound, a butadiene compound or a mixture thereof.
As the electrically insulating binder, a thermoplastic resin such as polyester, polycarbonate, acrylic, or polyamide; a thermosetting resin such as epoxy, urethane, or silicone; or a photocurable resin such as poly-N-vinylcarbazole alone is used. Alternatively, they can be used in combination. Examples of the solvent for adjusting the coating liquid include ethers such as tetrahydrofuran and 1,4-dioxane, chlorinated hydrocarbons such as dichloroethane and chloroform, and aromatic hydrocarbons such as toluene and xylene.

[0013]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited to the following examples unless it exceeds the gist.

[0014]

Example 1 5 g of oxytitanium phthalocyanine manufactured by Permachem Asia showing the X-ray diffraction spectrum shown in FIG.
In a paint shaker with 50 ml of glass beads
Dry milling for 00 hours. This powder is non-crystalline with almost no peak as in the X-ray diffraction spectrum shown in FIG. Next, 50 ml of n-butanol and 5 g of polyvinyl butyral are added and wet milling is performed for 5 hours. Further, 15 ml of cyclohexanone is added and dispersed for 30 hours. The solution obtained at this time is filtered, processed into pellets, and subjected to X-ray diffraction to obtain the spectrum shown in FIG.

The resulting solution is applied on an aluminum support and dried to form a 0.5 μm thick charge generating layer (2). A charge transfer layer (3) composed of 1 part by weight of polycarbonate was applied to 1 part by weight of 2-methyl-4-dibenzylaminobenzo-1-diphenylhydrazone so as to have a thickness of 20 μm. After drying for an minute, an electrophotographic photosensitive member was obtained.

[0016]

Example 2 100 ml of methanol was added to the amorphous oxytitanium phthalocyanine obtained in the same manner as in Example 1.
And 10 g of polyvinyl butyral, and wet milling is performed for 5 hours. Add 100 ml of methyl ethyl ketone and add 2
Disperse for 0 hours.

The resulting solution is applied on an aluminum support and dried to form a 0.5 μm charge generation layer (2). A charge transfer layer (3) composed of 1 part by weight of polycarbonate was applied to 1 part by weight of P-diethylaminoaldehyde-diphenylhydrazone to a thickness of 20 μm and dried at 80 ° C. for 1 hour to obtain an electrophotographic photosensitive member. Was.

[0018]

Comparative Example 1 X-ray diffraction spectrum CuKα 5 g of oxytitanium phthaloanine having a main diffraction peak at 27.3 ° at a black angle (2θ ± 0.2 °) of 27.3 ° and glass beads 5
0 ml, 200 ml of cyclohexanone, and 5 g of polyvinyl butyral are added, and dispersed with a paint shaker for 30 hours. This dispersion is applied on an aluminum support and dried to form a 0.5 μm charge generation layer. A charge transfer layer similar to that of Example 1 was provided thereon to obtain a photoconductor for electrophotography.

[0019]

Comparative Example 2 5 g of amorphous oxytitanium phthalocyanine obtained in the same manner as in Example 1 and glass beads 50
ml, 100 ml of cyclohexanone and 5 g of polyvinyl butyral were added and dispersed for 2 hours with a paint shaker, and 100 ml of methyl ethyl ketone was added thereto.
Disperse for 0 hours. This dispersion is applied on an aluminum support and dried to form a 0.5 μm charge generation layer. A charge transfer layer similar to that of Example 2 was provided thereon to obtain a photoconductor for electrophotography.

The first embodiment of the present invention formed as described above,
When the electrophotographic characteristics of Comparative Example 2 and Comparative Examples 1 and 2 were compared,
The result of FIG. 5 was obtained as a sensitivity distribution with respect to wavelength. Also one
Charge potential (Vo) in a cycle copy test of 10,000 sheets
The results of FIG. 6 were obtained by comparing the changes in the residual potential (Vr) (when both were negatively charged). Note that FIG.
6, 1 and 2 are the results of Examples 1 and 2, and 3 and 4 are the results of Comparative Examples 1 and 2. As is clear from FIG. 600-800 nm
It can be seen that the sensitivity is extremely high for the light in the region of.
It can also be seen that the stability of charging and residual potential in FIG. 6 is much more stable in Examples 1 and 2 than in Comparative Example.

[0021]

As is apparent from the above description, the black angle (2θ ± 0.2) in the X-ray diffraction spectrum as the charge generation layer is obtained.
2 °) Among charge generation layers showing a main diffraction peak at 27.3 °, higher sensitivity can be realized by a specific manufacturing method, thereby exhibiting sensitivity sufficiently applicable to high-speed printers and low-cost lasers. An electrophotographic photoreceptor having stability of potential and the like can be provided, which is extremely useful.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a CuKα-ray diffraction spectrum of the crystalline oxytitanium phthalocyanine of the present invention.

FIG. 3 is an X-ray diffraction spectrum of an oxytatinium phthalocyanine powder manufactured by Permachem Asia.

FIG. 4 is an X-ray diffraction spectrum of a non-crystalline oxytitanium phthalocyanine powder mechanically pulverized.

FIG. 5 shows Examples 1 and 2 of the present invention and Comparative Example 1,
FIG. 4 is a sensitivity distribution diagram with respect to wavelength 2;

FIG. 6 is a diagram comparing changes in the charged potential and the residual potential in a 10,000-sheet cycle copy test.

[Explanation of symbols]

 (1) Conductive substrate (2) Charge generation layer (3) Charge transfer layer 1 Example 1 2 Example 2 3 Comparative example 1 4 Comparative example 2

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-26961 (JP, A) JP-A-2-169671 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5 / 00,5 / 06

Claims (1)

(57) [Claims] 1. An electrophotographic photoreceptor having a charge generation layer containing an oxytitanium phthalocyanine crystal and a charge transfer layer on a conductive support, wherein the oxytitanium phthalocyanine photosensitive layer has a CuKα X-ray diffraction spectrum. Black angle (2θ ± 0.2 °) at 26.2 °
Powder oxytitanium phthalocyanine, which mainly shows clear diffraction peaks, is made amorphous by vacuum deposition, acid pasting or mechanical method, milled with an alcohol-based solvent containing a binder, and subjected to black angle (2θ) (± 0.2 °) It is formed by applying a solution dispersed in a ketone-based solvent that changes into crystalline oxytitanium phthalocyanine showing a clear diffraction peak mainly at 27.3 ° and does not change this crystal system. Electrophotographic photoreceptor.