JPH0219854A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body having improved photosensitivity and color sensitivity by forming a photoconductive layer contg. a specified disazo compd. on an electroconductive base body. CONSTITUTION:A photoconductive layer contg. a disazo compd. expressed by the formula I is formed on an electroconductive base body. In the formula I, X is an H atom, an alkoxy group, etc.; B is a coupler residue expressed by the formula II or III, wherein Z is an atomic group necessary for constituting a (substituted) aromatic carbocyclic ring or (substituted) heterocyclic ring; G is a (substituted) carbamoyl group or (substituted) sulfamoyl group, R1 is an H atom or a (substituted) alkyl group, etc.; M is a (substituted) aryl group. Thus, a novel disazo pigment suitable for a charge generating material having superior stabilizing effect for dispersion of coating liquid to be used for an org. photosensitive body is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to photoreceptors containing novel disazo pigments in the photogenerating layer.

Prior art A photoreceptor in which an organic charge-generating substance is blended into a resin binder and coated on a conductive substrate has been widely put into practical use due to its low toxicity, ease of manufacture, and low cost. ing.

Typical organic charge-generating materials that have been proposed include phthalocyanine, TNF, PVK, and derivatives, which can be combined with suitable charge transport substances such as hydrazones,
It is used in combination with oxadiazoles, etc.

Furthermore, in recent years, techniques have been proposed in which various disazo pigments are used in the charge generation layer. However, no reports have been found in which an azo pigment having a pyridazine heteroaromatic ring containing two nitrogen atoms at the center of its structure is used in an organic photoreceptor.

Problems to be Solved by the Invention Conventionally, during the manufacturing process of photoreceptors, the dispersion stability of pigment dispersions, especially for charge generation layer coatings, has been poor, and it has been a major problem that the pot life has an adverse effect on coating properties. there were.

The present invention solves these problems and provides a novel disazo pigment as a charge-generating material for organic photoreceptors, which has excellent dispersion stability in coating liquids, and is also excellent in photosensitivity, red color reproducibility, and repetition stability. With the goal.

Means for Solving the Problems The present invention provides the following general formula [■1;
is hydrogen atom; The atomic group necessary to constitute the aromatic carbocycle or aromatic heterocycle, which may have -G, which may have a substituent, carleno (moyl group or sulfamoyl group; R1 is hydrogen, M has a substituent, and M has a substituent; R2 and R1 are optionally substituted alkyl groups, aralkyl groups, or unsubstituted aryl groups; Y is a divalent aromatic hydrocarbon group or a nitrogen atom in the ring; Represents a divalent group containing The present invention relates to a photoreceptor characterized by having a photoconductive layer containing a disazo compound represented by 1.

In the present invention, by using the disazo pigment represented by the general formula [1] as a photoconductive substance of a photoreceptor, or by utilizing only the excellent charge generation ability of the disazo pigment of the present invention, it is possible to perform functional separation. By using it in the charge generation layer of a type photoreceptor, a photoreceptor that can exhibit excellent characteristics in sensitivity and color sensitivity can be produced.

In the general formula [1], represents a group.

B is a general formula [ff] to [■], where Z represents an aromatic carbocycle or an aromatic heterocycle which may have a substituent. Necessary atomic group: G represents a carbamoyl group or a sulfamoyl group which may have a substituent.

- genus In], for example, 2-hydroquine-3-phenylcarbamoylnaphthalene, 2-hydroxy-3-phenylcarbamoyl-11HbenzoLσ]
In the general formula [II[], in which carbazole etc. are preferred; R2 is hydrogen, an alkyl group which may have a substituent,
An amine group, a carbamoyl group, a carboxyl group and its ester group, or a cyano group; M represents an aryl group which may have a substituent;

The group represented by the general formula [II[] is preferably, for example, 3-methyl-1 to phenyl-5-pyrazolone.

In the general formula [IV] or [V], R2 and R3 represent an alkyl group, an aralkyl group, or an unsubstituted aryl group, which may have a substituent.

The group represented by the general formula [1''/] or [V] is, for example, N-methyl-4-hydroxynaphthalimide,
N-methyl-3-hydroxynaphthalimide and the like are preferred.

In the general formula [Vrl or [■]; Y represents a divalent group of aromatic hydrocarbon or a divalent group containing a nitrogen atom in the ring.

The group represented by the general formula [Vrl or [■] is, for example, 3-hydroxy and 4-hydroxy-7H-penzimidazo[2,1-a]benz[de]inquinolin-7-one or 2-hydroxy and 5-Hydroxy-7H-benzimidazo[2,la]benz[de
]Inquinoline-7-one and the like are preferred.

The disazo pigment represented by the general formula [11] of the present invention is produced by first reacting t; for example, 3,6-dimethylpyridazine with 0-nitrobenzene aldehyde or a substituted product thereof, to form di(0-nitrostyryl). A heterocyclic aromatic compound is obtained, the nitro group is roughly reduced to convert it into an amide 7 group, and this is converted into a diazonium salt by a conventional method, for example, by reacting with sodium nitrite in a hydrochloric acid solution,
The diazonium salt can then be coupled with the above-mentioned coupling agent to obtain lyE.

The photoreceptor of the present invention has a photoconductive layer in which a charge generation layer and a charge transport layer are laminated, even if it is a dispersed type containing a disazo pigment represented by the general formula [II].
It may be a functionally separated type containing a pigment represented by:

When the photoreceptor is a dispersion type photoreceptor, the photoreceptor of the present invention is a dispersion type photoreceptor.
A coating solution obtained by dissolving or dispersing the disazo pigment represented by the following along with a binder resin in a suitable solvent and adding a charge transporting substance as required is applied onto a conductive substrate, dried, and is usually 5 to 30 μm thick. Preferably, it can be manufactured by forming a photoconductive layer with a thickness of 6 to 20 μm.

Examples of the dispersion solvent for the charge generating substance include aromatic solvents such as toluene and xylene, ether solvents such as tetrahydrofuran and dioxane, N,N-dimethylformamide, etc.
Amide solvents, ketone solvents such as cyclohexanone and methyl ethyl ketone, and halogenated hydrocarbon solvents such as 1°2-dichloroethane-trichloroethane can be used.

The disazo pigment of the present invention is preferably 0.5 to 200% by weight, more preferably 30 to 15% by weight, based on the binder resin of the photoconductive layer.
Add 0% by weight. When it is less than 0.5% by weight, sufficient sensitivity cannot be obtained, and when it is more than 200% by weight, problems such as poor charging properties and poor film forming properties occur. The charge transport substance has the following formula; (wherein R11, R12, and R13 represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a hydroquine group, an ano group, a dialkylamino group, a diarylamino group, or a nitro group.) Triphenylamine represented by the following formula: % formula %) (wherein R31, R32, and R33 are hydrogen atoms, alkyl groups, alkoxy groups, halogen atoms, hydroxy groups, cyan groups, dialkylamino groups, diarylamino groups, diarylamino groups, (represents an aralkylamino group or a nitro group, n represents an integer of 1 or 2) Pyrazoline represented by the following formula; represents a group, an alkoxy group, a halogen atom, a hydroxy group, a cyano group, a dialkylamino group, a diarylamino group, a dialkylamino group, or a nitro group.

R4° represents a hydrogen atom or a phenyl group. ) Stilbene represented by the following formula; Carbazole hydrazone represented by the following formula: (In the formula, R, R17, Rla, RI9 and R2゜ are hydrogen atoms, alkyl groups, alkoxy groups, halogen atoms,
Represents a hydroxy group, cyano group, dialkylamino group, diarylamino group, dialkylamino group, or nitro group. R16 represents an alkyl group, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent.

Rla represents a hydrogen atom, an alkyl group, a cyano group, or a phenyl group which may have a substituent. ); (In the formula, R2S, R28 and Rff7 represent an alkyl group such as a methyl group or an ethyl group, and Rla and Ri
s represents an aryl group such as a phenyl group or a naphthol group.

) Tetraarylbutadiene etc. are mentioned. The amount of these charge transport substances is 280% by weight or less, preferably 25 to 75% by weight based on the binder resin of the photoconductive layer.
It is.

Particularly preferred charge transport materials in the present invention are N-ethylcarbazole-3-carbaldehydemethylphenylhydrazone (MPH), para-diethylaminobenzaldehyde diphenylhydrazone (DEH), 1.1
-diphenyl-4,4-bis-(p-diethylaminophenyl)-1,3-butadiene (FEB) and the like.

When using a binder in the carrier generation layer or carrier transport layer, any binder can be used, but it is preferable to use a film-forming polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating. preferable. Examples of such high molecular weight polymers include the following:
It is not limited to these. polycarbonate,
Polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride- Vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene-alkyd resin, poly-N-vinyl carbazole, polyvinyl butyrano-polyvinyl pharmaceutical.

These binders can be used alone or as a mixture of two or more.

It is desirable that these resins have a volume resistivity of 1×10 14 Ω·cm or more when measured alone.

In the case of a functionally separated photoreceptor, the photoreceptor of the present invention is prepared by coating a conductive substrate with a coating solution prepared by dispersing the disazo pigment of the present invention in a solution containing a binder resin, and drying it to form a charge generation layer. A charge transporting layer is obtained by forming a charge transporting layer, and then applying a solution prepared by dissolving a charge transporting substance and a binder resin in a suitable solvent thereon and drying the layer to form a charge transporting layer.

At this time, the thickness of the charge generation layer is 0.01 to 5 μm, preferably 0.05 to 2 μm, and the amount of the disazo pigment is 0.5 to 200% by weight based on the binder resin of the charge generation layer. . Preferably it is 30 to 150% by weight. The thickness of the charge transport layer is 2 to 100 μm, preferably 10 to 30 μm.
The amount of m1 charge transport material is from 50 to 200% by weight, in particular from 60 to 150% by weight, based on the binder resin of the charge transport layer. Incidentally, as the charge transport substance and the binder resin, the same substances as in the dispersed type are used. Further, in a functionally separated photoreceptor, the charge generation layer may be placed on the surface side and the charge transport material may be placed on the substrate side, or vice versa.

Table 1 shows the structure of the disazo compound of the present invention synthesized from a fish prong and the compound number assigned thereto.

(Hereafter, in the margin) Table■ Synthesis table of disazo compound (circle)■ (Continued) (Hereafter, in the margin) L First, 24 g of 3,6-dimethylpyridazine and 67 g of O-nitrobenzaldehyde were added to 600 m12 of propionic anhydride.
3.6-di(0-
nitrostyryl)pyridazine 339 was obtained.

Next, this dinitro compound is reduced by a known method to obtain 16 g of a diamino compound.

Furthermore, using this amino compound, a diazotization reaction and a coupling reaction are performed according to a known method to form a disazo pigment (P
i) Obtained 16 g:.

Disazo pigment (PI) is a black-purple crystal with a decomposition point of 210
It was °C.

In addition, the starting material 3,6-dimethylpyridazine is J, A
m, Chem, Soc,, 78. 1961 (1
It can be easily synthesized from the condensation of γ-diketone and hydrazine according to the description of 965) et al.

Synthesis of disazo compounds CP2 to P5) Disazo compounds P2 to P5 were prepared in the same manner as in the synthesis example of compound Pi except that the coupler components were changed. (manufactured by Toyobo Co., Ltd.) was added to 100 g of cyclohexane and dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum had been vapor-deposited so that the dry film thickness would be 0.1 μm to form a carrier generation layer, and then 10 g of the following hydrazone compound (C-1) was applied as a carrier transport layer on top of this. Polycarbonate resin “K1300J (manufactured by Yojin Co., Ltd.) 10g
A photoreceptor of the present invention was prepared by dissolving a solution of 50 g of tetrahydrofuran in 50 g of tetrahydrofuran and applying the solution to a dry film thickness of 20 μm to form a carrier transport layer.

This photoreceptor is charged to a surface potential of -500V using a charger, and halogen lamp light is irradiated to determine the half-reduction exposure amount El/2 required to attenuate the surface potential by half.

Hydrazone compound (C-1) Synthesized.

Table 2 The results are shown in Table 2.

Examples 2 to 5 Disazo compounds (P2 to P5), hydrazone compounds (C
-1) was carried out in the same manner as in Example 1.

The results are shown in Table 2.

Examples (5 to 10) The same procedure as in Example 1 was carried out using the disazo compound (Pi-P5) and the following butadiene compound (C-2) in the carrier transport layer. The results are shown in Table 2.

Hydrazone Compound (C-2) (C-2) Effects of the Invention The present invention provided a novel disazo pigment for generating photocharges.

The photoreceptor obtained according to the present invention has high photosensitivity and excellent color sensitivity.

Claims (1)

[Claims] 1. The following general formula [I] on a conductive substrate; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, X is a hydrogen atom, a halogen atom, an alkyl group,
The alkoxy group or dialkylamino group, B is a coupler residue, and the following general formulas [II] to [VII] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ III] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [IV] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [V] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [VI] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [VII] where Z is a group of atoms necessary to constitute an aromatic carbon ring or an aromatic heterocycle, which may have a substituent; R_1 is hydrogen, an alkyl group, an amino group, a carbamoyl group, a carboxyl group and its ester group, or a cyano group, which may have a substituent; M has a substituent; R_2 and R_3 are alkyl groups, aralkyl groups, or unsubstituted aryl groups that may have substituents; Y is a divalent group of aromatic hydrocarbon or a nitrogen atom in the ring; represents a divalent group contained in ] A photoreceptor characterized by having a photoconductive layer containing a disazo compound represented by the following.