JP2960179B2 - 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 photosensitive member containing a hydrazone compound as a charge transport material.

[0002]

2. Description of the Related Art At present, as a photoreceptor for electrophotography, a function-separated type photoreceptor containing a charge generating substance having photosensitivity at the wavelength of a light source and a charge transporting substance having a high charge transfer speed is widely used. .

Hitherto, hydrazone compounds, styryl compounds, pyrazoline compounds, triphenylamine compounds and the like, which are low-molecular conductive materials, have been used as charge transport materials.

[0004]

SUMMARY OF THE INVENTION Polyfunctional hydrazone compounds having a plurality of hydrazone bonds in one molecule have been developed. However, electrophotographic photoreceptors using this polyfunctional hydrazone compound as a charge transport material have problems in sensitivity, mechanical and chemical durability, solubility in polymers, and the like, and satisfactory ones have not yet been obtained. Absent.

An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity, excellent solubility, and excellent mechanical and chemical durability.

[0006]

The electrophotographic photoreceptor of the present invention contains a hydrazone compound represented by the following formula (2).

Embedded image (However, R ¹ and R ² represent a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted aralkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a hydroxyl group, or a halogen atom. shown, R ^3, R ⁴ represents an alkoxy group, a substituted or unsubstituted aralkoxy, substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group,, R ^5, R ⁶ and R ⁷ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted, shows a heterocyclic group, the one R ⁶ and R ⁷ complex May form a ring residue, l and m each represent an integer of 0 to 3, and x represents an integer of 2 or 3.)

The hydrazone compound of the present invention can be obtained by condensing various aldehyde compounds and hydrazine compounds in the presence of an acid catalyst.

Next, specific examples of the substituents R ¹ and R ² of the hydrazone compound represented by the chemical formula ² are shown in Table 1, specific examples of the substituents R ³ and R ⁴ are shown in Table 2, and the substituents R ⁵ and R Table 3 shows specific examples of ⁶ and R ⁷ .

[Table 1]

[Table 2]

[Table 3]

The hydrazone compound represented by Chemical formula 2 can be used in the same manner as a usual charge transport substance. The form of the electrophotographic photoreceptor of the present invention is shown below.

FIGS. 1, 2 and 3 are cross-sectional views of the electrophotographic photosensitive member of the present invention. In the electrophotographic photoreceptor shown in FIG. 1, a charge generation layer 3 made of only a charge generation substance 2 or a polymer containing the charge generation substance 2 is laminated on a conductive support 1, and a charge transport substance 4 is deposited thereon. And a charge transport layer 5 made of a polymer containing the same. In this case, a small amount of the charge transport material 4 may be added to the charge generation layer 3. The electrophotographic photoreceptor shown in FIG. 2 has a structure in which a charge transport layer 5 is laminated on a conductive support 1 and a charge generation layer 3 is laminated thereon. In this case, a protective layer may be formed on the charge generation layer 3 as needed. The electrophotographic photoreceptor shown in FIG.
The photosensitive layer 6 in which the charge generating substance 2 is dispersed in a polymer containing the charge transporting substance 4 is laminated on the substrate 1.

The charge generation layer 3 shown in FIG. 1 and FIG.
The charge generation material 2 may be formed by vapor deposition, or may be formed by applying a dispersion of the charge generation material 2 in a polymer solution. As the charge generating substance and the polymer, those used in a usual electrophotographic photoreceptor can be used. As the charge generating substance, various dyes having photosensitivity at the wavelength of the light source, for example, perylene pigments, azo pigments, phthalocyanine pigments, and squarium pigments can be used. The polymer can be used as long as it has an excellent adhesive property and an insulating property.

A plasticizer may be used in the photosensitive layer 6 in order to improve flexibility, adhesion, and mechanical strength. Also,
An intermediate layer may be provided between the conductive support 1 and the photosensitive layer 6 in order to improve adhesion and charging properties. For coating the photosensitive layer 6 and the intermediate layer, a doctor blade, a wire bar, a roll coater or the like is usually used. The film thickness of the photosensitive layer 6 is 5 μm or less, preferably 0.1 to 1 μm in the case of the electrophotographic photoreceptors of FIGS. Is 5 to 50 μm, preferably 10 to 2
0 μm. Further, when an intermediate layer is provided, the thickness of the intermediate layer is preferably 1 μm or less.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

(Example 1) A method for synthesizing a hydrazone compound represented by Chemical Formula 3 will be described. 9.82 g (20 mmol) of the bis-type aldehyde compound shown in Chemical Formula 4 and 8.10 g (44 mmol) of diphenylhydrazine were refluxed in toluene under a p-toluenesulfonic acid catalyst for 5 hours. After completion of the reaction, the reaction product, a hydrazone compound of Chemical Formula 3, was separated by thin-layer chromatography to obtain a red-yellow product in a yield of 9.72 g. The product was recrystallized with a mixed solvent of ethanol and acetone. Table 4 shows the results of the elemental analysis.

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Example 2 5 g of a squarium pigment obtained by reacting squaric acid with N, N-dimethylaniline, 20 g of a polyester resin, and cyclohexanone 4
00g was mixed and dispersed with a shaking disperser for 3 hours. The obtained solution was applied on an Al-deposited polyester film with a wire bar to form a charge generation layer having a thickness of 0.5 μm. Next, 10 g of a hydrazone compound represented by Chemical Formula 3 as a charge transport material was dissolved in a polymer solution in which 10 g of a polycarbonate resin was dissolved in 90 g of cyclohexanone. Apply the obtained solution on the charge generation layer with a wire bar,
A charge transport layer having a thickness of 17 μm was formed to produce a photoconductor for electrophotography. This hydrazone compound 1 was excellent in solubility in a solvent and could form a charge transport layer uniformly.

The electrophotographic photoreceptor thus produced was corona-charged at -6 KV in a dark place and then exposed to a 5 lux illuminant W lamp to examine charging characteristics. The charging characteristics include an initial charging potential V ₀ after charging and a surface potential of −6.
Time t required for dark decay from 20V to -600V
D, Exposure amount E1 / 2 required to attenuate light from -600 V to -300 V was measured. Further, the same operation was repeated on the electrophotographic photoreceptor, and V ₀ (100
0), tD (1000) and E1 / 2 (1000) were measured, and the durability was examined. The results were as follows.

V ₀ = −770 V t D = 15 sec E 1/2 = 2.6 lux · sec V ₀ (1000) = − 765 V t D (1000) = 13 sec E 1/2 (1000) = 2.8 lux · sec

Comparative Example 1 An electrophotographic photoreceptor was prepared under the same conditions as in Example 2 except that a hydrazone compound represented by Chemical Formula 5 was used as a charge transporting substance.

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The hydrazone compound represented by Chemical Formula 5 has low solubility in a solvent, and crystallized in the charge transport layer. For this reason, the light transmittance in the charge transport layer has been significantly reduced, and it has been difficult to use it as a charge transport material due to poor flexibility.

Examples 3 to 11 Electrophotographic photoreceptors were prepared under the same conditions as in Example 2 except that the hydrazone compound shown in Chemical formulas 6 to 14 was used as the charge transport material. Table 5 shows the charging characteristics of the produced electrophotographic photosensitive member.

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[Table 5]

[0021]

As described above, the polyfunctional hydrazone compound used in the present invention is a charge transporting substance having high sensitivity, excellent solubility in various solvents and flexibility, and less decrease in sensitivity and chemical deterioration due to repeated use. According to the present invention, a high printing durability electrophotographic photoreceptor having high sensitivity and excellent mechanical and chemical durability can be provided. Further, the electrophotographic photoreceptor of the present invention can be applied to a laser printer, a liquid crystal shutter printer, an LED printer, a copying machine, an electrophotographic plate making system, and the like.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the electrophotographic photoconductor of the present invention.

FIG. 3 is a cross-sectional view of the electrophotographic photoconductor of the present invention.

[Explanation of symbols]

 Reference Signs List 1 conductive support 3 charge generation layer 5 charge transport layer 6 photosensitive layer

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-237555 (JP, A) JP-A-57-144561 (JP, A) JP-A-64-63968 (JP, A) JP-A-1-237555 267553 (JP, A) JP-A-3-110567 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/06

Claims (1)

(57) [Claims] 1. An electrophotographic photoconductor comprising a hydrazone compound represented by the following chemical formula 1. Embedded image (However, R ¹ and R ² represent a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted aralkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a hydroxyl group, or a halogen atom. shown, R ^3, R ⁴ represents an alkoxy group, a substituted or unsubstituted aralkoxy, substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group,, R ^5, R ⁶ and R ⁷ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted, shows a heterocyclic group, the one R ⁶ and R ⁷ complex May form a ring residue, l and m each represent an integer of 0 to 3, and x represents an integer of 2 or 3.)