JP2965400B2 - Dichlorotin phthalocyanine crystal and electrophotographic photoreceptor using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dichlorotin phthalocyanine crystal useful as a photoconductive material and an electrophotographic photosensitive member using the same.

[0002]

2. Description of the Related Art Phthalocyanines are used in paints, printing inks,
It is a useful material as a catalyst or an electronic material, and in particular, has been extensively studied in recent years as an electrophotographic photosensitive member material, an optical recording material, and a photoelectric conversion material. Regarding the electrophotographic photoreceptor, in recent years, the photosensitive wavelength range of the organic photoconductive material conventionally proposed has been changed to the wavelength of near infrared semiconductor laser (78 nm).
There is a growing demand for the photoreceptor to be used as a photoreceptor for digital recording such as a laser printer or the like, and from this viewpoint, squarylium compounds (JP-A-49-105536 and JP-A-58-21410).
JP), triphenylamine trisazo compounds (JP-A-61-151059), and phthalocyanine compounds (JP-A-48-34189 and 57-14874).
No. 5) has been proposed as a photoconductive material for a semiconductor laser.

When an organic photoconductive material is used as a photosensitive material for a semiconductor laser, first, the photosensitive wavelength range extends to a long wavelength, and then, the sensitivity and durability of the formed photosensitive member are good. Is required. The above-mentioned organic photoconductive material does not sufficiently satisfy these conditions. In order to overcome these drawbacks, the relationship between the crystal type and the electrophotographic characteristics of the organic photoconductive material has been studied, and many reports have been made especially on phthalocyanine compounds.

[0004] In general, phthalocyanine compounds exhibit several crystal forms depending on the production method and treatment method, and it is known that the difference in crystal form greatly affects the photoelectric conversion characteristics of the phthalocyanine compound. . Regarding the crystal form of the phthalocyanine compound, for example, when looking at copper phthalocyanine, in addition to the stable β form, α, π,
Crystal forms such as χ, ρ, γ, and δ are known, and it is known that these crystal forms can be mutually transformed by mechanical tension, sulfuric acid treatment, organic solvent treatment, heat treatment, and the like. (Eg, U.S. Pat. Nos. 2,770,020, 3,100,035, 3,708,292 and 3,357,989). Also, Japanese Patent Laid-Open No. 50-3
No. 8543 describes a difference in crystal form of copper phthalocyanine and electrophotographic characteristics.

Japanese Patent Application Laid-Open No. Sho 62-11947 describes an electrophotographic photoreceptor using dihalogenostin phthalocyanine as a charge generating material.
No. 14405 describes a tin phthalocyanine compound having a specific diffraction peak on an X-ray diffraction diagram and an electrophotographic photosensitive member using the same. Further, Japanese Unexamined Patent Publication No. Sho 62
No. 119,947 discloses a Bragg angle of 8.4 °, 1
In addition to 2.2 ° and 13.8 °, 26.5 ° and 28.2
A tin phthalocyanine compound having a diffraction peak having an equivalent diffraction intensity at 0 ° is disclosed.

[0006]

However, the above-mentioned phthalocyanine compounds which have been conventionally developed have not been sufficiently satisfactory in light sensitivity and durability when used as a photosensitive material. The present invention has been made in view of the above-described circumstances in the related art. That is, an object of the present invention is to provide a novel crystal of dichlorotin phthalocyanine useful as a photoconductive material having sensitivity in a long wavelength region. Another object of the present invention is to
An object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity and durability using a novel crystal of dichlorotin phthalocyanine as a photoconductive material.

[0007]

As a result of the study, the present inventors have conducted a specific treatment on a dichlorotin phthalocyanine crystal obtained by synthesis to obtain a novel photoconductive material having high sensitivity and durability as a photoconductive material. The inventors have found that an excellent crystal can be obtained, and have completed the present invention.

The dichlorotin phthalocyanine crystal of the present invention has a Bragg angle (2θ ± 0.2) with respect to CuKα ray.
°) at 28.2 ° and a Bragg angle of 2
In the range of 5 ° to 30 °, the diffraction peak intensity other than 28.2 ° is not more than 30% of the diffraction peak intensity at 28.2 °. As a preferable example of the dichlorotin phthalocyanine crystal of the present invention, a Bragg angle (2θ ± 0.2 °) with respect to CuKα ray = 8.3 °, 1
Those having distinct diffraction peaks at 2.2 °, 13.7 ° and 28.2 ° can be mentioned. The electrophotographic photoreceptor of the present invention is characterized in that a photosensitive layer containing at least the above-mentioned dichlorotin phthalocyanine crystal is provided on a conductive support.

Hereinafter, the present invention will be described in detail. The novel dichlorotin phthalocyanine crystal of the present invention can be produced by grinding a dichlorotin phthalocyanine crystal produced by a known method with mechanical force or in a specific organic solvent. Examples of the device used for grinding include, but are not limited to, a mortar, a ball mill, an attritor, and a sand mill. Also, if necessary, grinding media such as glass beads, steel beads, or salt,
Grinding aids such as silica gel can be used. Since the time required for grinding depends on the type and capacity of the equipment,
In practice, it is desirable to determine while confirming the X-ray diffraction of a part of the ground sample. As an example, when the ball mill described in Example 1 described later is used, 30 minutes to 4 minutes
Time is preferred, and prolonged milling is not preferred as it can result in different crystal forms. Further, as an organic solvent used at the time of grinding, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate,
Esters such as n-butyl acetate, ethers, N, N-
Examples thereof include amides such as dimethylformamide and N-methylpyrrolidone, and alkyl halides such as methylene chloride, chloroform and 1,1,2-trichloroethane. Of these, one or a mixture of two or more thereof is used. Can be selected and used. The pulverization treatment in the organic solvent may be performed in a temperature range of 10 to 50 ° C., usually at room temperature for 10 to 100 hours.

Next, an electrophotographic photosensitive member using the dichlorotin phthalocyanine crystal of the present invention as a photoconductive material in a photosensitive layer will be described. The electrophotographic photoreceptor of the present invention may have a single-layer photosensitive layer or a laminated structure in which a charge generation layer and a charge transport layer are functionally separated.

When the photosensitive layer has a laminated structure, the charge generation layer is composed of the above-mentioned dichlorotin phthalocyanine crystal and a binder resin. The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene. Preferred binder resins include polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic resin, polyacrylamide ,polyamide,
Polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin, casein, polyvinyl alcohol,
An insulating resin such as polyvinylpyrrolidone can be used.

The charge generation layer is formed by dispersing the above-mentioned dichlorotin phthalocyanine crystal in a solution in which the above-mentioned binder resin is dissolved in an organic solvent to prepare a coating solution, and applying it to a conductive support. can do. In that case, the compounding ratio of the dichlorotin phthalocyanine crystal and the binder resin to be used is 40: 1 to 1:10, preferably 10: 1.
1-1: 4. When the ratio of the dichlorotin phthalocyanine crystal is too high, the stability of the coating solution is lowered, and when it is too low, the sensitivity is lowered.

The solvent used is preferably selected from those which do not dissolve the undercoat layer or the charge transport layer.
Specific organic solvents include methanol, ethanol,
Alcohols such as isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N
Amides such as -dimethylformamide and N, N-dimethylacetamide; ethers such as tetrahydrofuran, dioxane and ethylene glycol monomethyl ether;
Esters such as methyl acetate and ethyl acetate; aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, and trichloroethylene; and aromatic hydrocarbons such as benzene, toluene, xylene, monochlorobenzene, and dichlorobenzene. Can be used.

The coating solution can be applied by a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, and a curtain coating method. . The drying is preferably performed by touch drying at room temperature and then heating and drying. The heating and drying can be performed at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours in a still or blown state. The thickness of the charge generation layer is usually 0.05
５5 μm.

The charge transport layer comprises a charge transport material and a binder resin. Examples of the charge transporting material include polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, compounds having a nitrogen-containing heterocycle such as indole, carbazole and imidazole, pyrazoline compounds, hydrazone compounds, triphenylmethane compounds and triphenylamine compounds. And any known compounds such as an enamine compound and a stilbene compound can be used. Furthermore, poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylanthracene, poly-N-vinylphenylanthracene, polyvinylpyrene, polyvinylacridine, polyvinylacenaphthylene, polyglycidylcarbazole, pyrene-formaldehyde resin, Examples include photoconductive polymers such as ethylcarbazole-formaldehyde resin, which may themselves form a layer. Further, as the binder resin, the same insulating resin as that used for the above-described charge generation layer can be used.

The charge transport layer can be formed by preparing a coating solution using the charge transport material, the binder resin and the same organic solvent as described above, and then applying the same in the same manner. The mixing ratio (parts by weight) of the charge transport material and the binder resin is usually 5: 1 to 1
It is set in the range of 1: 5. The thickness of the charge transport layer is usually set to about 5 to 50 μm.

When the electrophotographic photoreceptor has a single-layer structure, the photosensitive layer comprises a photoconductive layer having a structure in which the above-mentioned dichlorotin phthalocyanine crystal is dispersed in a layer comprising a charge transport material and a binder resin. . In this case, the compounding ratio of the charge transporting material to the binder resin is set to about 1:20 to 5: 1, and the compounding ratio of the dichlorotin phthalocyanine crystal to the charge transporting material is set to about 1:10 to 10: 1. Is preferred. The same charge transporting material and binder resin as described above are used, and the photoconductive layer is formed in the same manner as above.

As the conductive support, any one can be used as long as it is known to be used as an electrophotographic photosensitive member. In the present invention, an undercoat layer may be provided on the conductive support. The undercoat layer is effective for preventing unnecessary charge injection from the conductive support, and has an effect of increasing the chargeability of the photosensitive layer. Further, it also has the effect of increasing the adhesion between the photosensitive layer and the conductive support.
Examples of the material constituting the undercoat layer include polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, cellulose ethers, cellulose esters, polyamide, polyurethane, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, Examples include polyacrylamide, zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds, titanyl chelate compounds, titanyl alkoxide compounds, organic titanyl compounds, silane coupling agents, and the like. The thickness of the undercoat layer is 0.05 to
It is preferably set to about 2 μm.

[0019]

The present invention will be described below by way of examples. Synthesis Example (Synthesis of dichlorotin phthalocyanine) 50 g of phthalonitrile and 27 g of anhydrous stannic chloride were added to
The mixture was added to 350 ml of 1-chloronaphthalene and reacted at 195 ° C. for 5 hours. The product was separated by filtration, washed with 1-chloronaphthalene, acetone, methanol and water, and dried under reduced pressure to obtain dichlorotin phthalocyanine. 18.3 g (27%) of crystals were obtained. FIG. 1 shows a powder X-ray diffraction pattern of the obtained dichlorotin phthalocyanine crystal.

Example 1 5 g of dichlorotin phthalocyanine crystal obtained in Synthesis Example
Was put into an agate pot (500 ml) together with 500 g of agate ball (20 mmφ), and 1 at 400 rpm using a planetary ball mill (Fritsch: P-5 type).
Milled for 0 hours. FIG. 2 shows an X-ray powder diffraction pattern of the obtained dichlorotin phthalocyanine crystal.

Example 2 1 g of dichlorotin phthalocyanine crystal obtained in the synthesis example
Together with 100 g of glass beads (1 mmφ) by ball mill in 30 ml of methylene chloride at room temperature.
After pulverizing for 4 hours, the obtained slurry was filtered, washed repeatedly with methanol, and dried under reduced pressure to obtain 0.95 g of dichlorotin phthalocyanine crystals. FIG. 3 shows a powder X-ray diffraction pattern of the obtained dichlorotin phthalocyanine crystal.

Example 3 The procedure of Example 2 was repeated, except that methyl ethyl ketone was used as a solvent during pulverization, to obtain 0.86 g of dichlorotin phthalocyanine crystals. FIG. 4 shows a powder X-ray diffraction pattern of the obtained dichlorotin phthalocyanine crystal.

Example 4 Dichlorotin phthalocyanine crystal 1 obtained in Example 1
Part is polyvinyl butyral (trade name: Eslec BM
-1, Sekisui Chemical Co., Ltd.) 1 part and cyclohexanone 10
After mixing with glass beads and treating with a glass bead for 1 hour using a paint shaker, the obtained coating solution was applied onto an aluminum substrate by a dip coating method, and then heated to 100 ° C.
For 5 minutes to form a charge generation layer having a thickness of 0.2 μm. Next, the following structural formula

[0024]

Embedded image 2 parts of a compound represented by the following structural formula

[0025]

Embedded image

3 parts of poly (4,4-cyclohexylidenediphenylene carbonate) is dissolved in 20 parts of monochlorobenzene, and the obtained coating solution is dip-coated on an aluminum substrate on which a charge generation layer is formed. And dried by heating at 120 ° C for 1 hour.
A 0 μm charge transport layer was formed. The obtained electrophotographic photoreceptor is placed in an environment of normal temperature and normal humidity (20 ° C., 40 % RH),
Electrostatic copying tester (EPA-8100, Kawaguchi Electric Co., Ltd.)
-6 KV corona discharge, and after charging, the light of the tungsten lamp was converted to monochromatic light of 800 nm using a monochromator, and 1 μW on the surface of the photoreceptor.
/ Cm ² and irradiation. Then, the exposure E1 / 2 (erg / cm ² ) until the surface potential becomes 1/2 of the initial V0 (volt) is measured, and then 10 lux tungsten light is irradiated on the photoreceptor surface for 1 second,
The residual potential VR was measured. Further, V0, E1 / 2, and VR after the above charging and exposure were repeated 1000 times were measured. Table 1 shows the results.

Examples 5 and 6 In Example 4, except that the dichlorotin phthalocyanine crystals obtained in Examples 2 and 3 were used, a charge generation layer and a charge transport layer were formed in the same manner to form an electrophotographic photosensitive member. A body was prepared and evaluated in the same manner. Table 1 shows the results.

Comparative Example 1 A charge generating layer and a charge transport layer were formed in the same manner as in Example 4 except that the dichlorotin phthalocyanine crystal obtained in the synthesis example was used as it was to produce an electrophotographic photosensitive member. And evaluated in the same manner. Table 1 shows the results.

COMPARATIVE EXAMPLE 2 One part of the dichlorotin phthalocyanine crystal obtained in the synthesis example was gradually added to 30 parts of concentrated sulfuric acid at 0 to 5 ° C. under ice cooling to dissolve, and a small amount of insoluble matter was filtered off. Was dropped into 500 parts of ice water with vigorous stirring, and the formed precipitate was separated by filtration.
Washing was repeatedly performed with water until the washing solution became neutral. Thereafter, the crystals were dried under reduced pressure to obtain dichlorotin phthalocyanine crystals.
76 parts were obtained. FIG. 5 shows a powder X-ray diffraction pattern of the obtained dichlorotin phthalocyanine crystal. Except for using the dichlorotin phthalocyanine crystal obtained as described above, a charge generation layer and a charge transport layer were formed in the same manner as in Example 3 to produce an electrophotographic photoreceptor, and evaluation was performed in the same manner. did. Table 1 shows the results.

[0030]

[Table 1]

[0031]

The dichlorotin phthalocyanine crystal of the present invention is of a novel crystal type and has a photosensitive wavelength range extending to a long wavelength, so that the light of an electrophotographic photosensitive member such as a printer using a semiconductor laser can be used. Very useful as a conductive material. Further, the electrophotographic photoreceptor of the present invention formed using the dichlorotin phthalocyanine crystal having the above-mentioned novel crystal form has high sensitivity, low residual potential, high chargeability, and little variation due to repeated use. Therefore, it is useful as a highly durable photoreceptor.

[Brief description of the drawings]

FIG. 1 is a powder X-ray diffraction diagram of a dichlorotin phthalocyanine crystal obtained in a synthesis example.

FIG. 2 is a powder X-ray diffraction diagram of the dichlorotin phthalocyanine crystal obtained in Example 1.

FIG. 3 is a powder X-ray diffraction diagram of the dichlorotin phthalocyanine crystal obtained in Example 2.

FIG. 4 is a powder X-ray diffraction diagram of the dichlorotin phthalocyanine crystal obtained in Example 3.

FIG. 5 is a powder X-ray diffraction diagram of the dichlorotin phthalocyanine crystal obtained in Comparative Example 2.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masakazu Iijima 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside the Fujimatsu Rocks Co., Ltd. (56) References JP-A-62-119547 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09B 47/04 G03G 5/06 371 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A Bragg angle (2θ) with respect to a CuKα ray.
± 0.2 °) at 28.2 °, and within the Bragg angle range of 25 ° to 30 °, the diffraction peak intensity other than 28.2 ° is 30% of the 28.2 ° diffraction peak intensity. % Or less, dichlorotin phthalocyanine crystal. 2. A Bragg angle (2θ) with respect to a CuKα ray.
2. The dichlorotin phthalocyanine crystal according to claim 1, having distinct diffraction peaks at positions of (± 0.2 °) = 8.3 °, 12.2 °, 13.7 ° and 28.2 °. 3. The method according to claim 1, wherein at least the conductive support is provided on a conductive support.
Or an electrophotographic photosensitive member comprising a photosensitive layer containing the dichlorotin phthalocyanine crystal according to 2.