JPH03269539A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body usable for all the presently used electrophotographic processes and sufficient in spectral sensitivity in the wide wavelength regions from the visible light to near infrared rays by using a specified squarium pigment. CONSTITUTION:The electrophotographic sensitive body contains the squarium pigment represented by formula I in which each of R1-R5 is H, halogen, such as F, Cl, Br, or I, an optionally substituted aliphatic hydrocarbon group, such as methyl or ethyl, hydroxy, alkoxy, amino, aryl, or a heterocyclic group, thus permitting the obtained electrophotographic sensitive body to be usable for all the presently used electrophotographic processes and sufficient in the spectral sensitivity in the wide range from the visible wavelength region to the near infrared wavelength region.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor used in an electrophotographic process. More specifically, the present invention relates to an electrophotographic photoreceptor containing a squareium pigment represented by the general formula (I).

[Conventional technology]

Conventionally, amorphous selenium,
Inorganic photosensitive materials such as cadmium sulfide and zinc oxide, and organic photosensitive materials such as azo compounds and squareium pigments are widely known.

It is well known that amorphous selenium and the like have excellent properties as materials for electrophotographic photoreceptors and are in practical use.

[Problem to be solved by the invention]

However, this electrophotographic photoreceptor is difficult to dispose of because it is toxic. Electrophotographic photoreceptors in which zinc oxide is dispersed in a resin have poor mechanical strength and cannot withstand repeated use.

Although organic photosensitive materials are excellent in processability such as film formation, no material with sufficient sensitivity has been obtained as an electrophotographic photoreceptor.

The object of the present invention is to provide an electrophotographic photoreceptor that solves the conventional problems and can be used in all currently used electrophotographic processes, and that can be used in a wide wavelength range from the visible region to the near infrared region. An object of the present invention is to provide an electrophotographic photoreceptor having sufficient spectral sensitivity.

[Means to solve the problem]

The squareium pigment used in the electrophotographic photoreceptor of the present invention is represented by general formula (I).

(However, in the formula, R1, R2, R3, R4, and R5 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an alkoxy group, an amino group, an aryl group, a heterocyclic group, or a hydroxyl group.) In the formula, the halogen atoms represented by R1, R2, R3, R4 and R5 include fluorine, chlorine, bromine and iodine. In addition, examples of aliphatic hydrocarbon groups include methyl group, ethyl group, propyl group, normal butyl group, isobutyl group, tarjarifthyl group, 5-
Methyldodecyl group, trifluoromethyl group, 3-phenyloctyl group, cyclopropyl group, cyclopentyl group,
Examples include 1-cyclohexenyl group, hinyl group, l-flobenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 2-pentenyl group, and ethynyl group. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, impropoxy group, butoxy group, pentyloxy group, and benzyloxy group.

Examples of amino groups include methylamino group, ethylamino group, propylamino group, isopropylamino group, butylamino group, inbutylamino group, tertiary-butylamino group, 3-phenyloctylamino group, dimethylamino group,
Examples include diethylamino group, dipropylamino group, diisopropylamino group, ethylphenylamino group, and di-3-phenyloctylamino group. Aryl groups include phenyl group, p-dimethylaminophenyl group, p-ethylmethylaminophenyl group, 0-ethylphenyl group,
Examples include 3.5-dichlorophenyl group, i-naphthyl group, l-methyl-2-naphthyl group, and 3-methylazo-4-dimethylaminophenyl group. As a heterocyclic group, N
-Methyl-2-pyrrolyl group, 2-thienyl group, 2-cenyl group, 2-furyl group, furfuryl group, 2-pyridyl group,
1.5-dimethyl-2-pyrrolyl group, 2-quinolyl group,
Examples include N-methyl-4-piperidyl group and piperidino group.

This squareium pigment is shown by the following structural formula (tl)
-3,4-dihydroxy-3-cyclobutene-1,2
It can be obtained by reacting -dione with an azo compound represented by the following -Momonena (III) in a solvent. Examples of the solvent include aliphatic alcohols such as methanol, ethanol, globanol, phthanol, and amyl alcohol.

(However, in the formula, R1, R2, R3, R4, and R5 are hydrogen atoms.) Represents a rogene atom, a substituted or unsubstituted aliphatic hydrocarbon group, an alkoxy group, an amino group, an aryl group, a heterocyclic group, or a hydroxyl group. . ) Cross-sectional views of the electrophotographic photoreceptor of the present invention are shown in FIGS. 1 to 3.

FIG. 1 is a sectional view of a laminated electrophotographic photoreceptor in which a charge generation layer 102 is formed on a conductive support 101 and a charge transport layer 106 is formed on the charge generation layer 102. Second
The figure is a cross-sectional view of a laminated electrophotographic photoreceptor in which a charge transport layer 106 is formed on a conductive support 101 and a charge generation layer 102 is formed on the charge transport layer 106. In the laminated electrophotographic photoreceptor shown in FIGS. 1 and 2, a photosensitive layer 104 is formed by a charge generation layer 102 and a charge transport layer 106. FIG. 3 is a cross-sectional view of a single-layer electrophotographic photoreceptor in which a photosensitive layer 104 is formed on a conductive support 101.

The charge generation layer 102 is provided on the conductive support 101 or the charge transport layer 103, and its thickness is preferably 0.1 μm to 1.98 m, particularly 0.3 μm to 1.0 μm. In order to form the charge generation layer 102, - pattern hole (I
) is used alone, or this squareium pigment is used dispersed in a binder resin. When a squareium pigment is used alone, the charge generation layer 102 is formed by solvent spraying or vacuum deposition.
form. When a squareium pigment dispersed in a binder resin is used, the ratio of the squareium pigment to the binder resin is 10% to 90% by weight, preferably 25% to 30% by weight.

In this case, the squareium pigment is thoroughly pulverized using a ball mill or paint conditioner and dispersed in the binder resin. As the binder resin, for example, photoconductive polymers such as polyvinylcarbazole, polyvinylcarbachy+ derivatives, polyvinylnaphthalene, polyvinylanthracene, polyvinylpyrene, and other organic mal-IJ Fuchs materials having charge transport ability can be used. Insulating resins that exhibit photoconductivity, such as polystyrene, polyester, polycarbonate, and derivatives thereof, can also be used. At this time, in order to improve the strength of the photoreceptor, a plasticizer can be used in the same manner as in general polymer materials. As the plasticizer, chlorinated paraffin, chlorinated biphenyl, phosphate plasticizer, etc. can be used. The plasticizer is used in an amount of 20% by weight or less based on the binder resin, within a range that does not impair the properties of the photoreceptor. When a squareium pigment dispersed in a binder resin is used, the charge generation layer 102 is formed by a spray method, a barcoder method, or the like.

As the material of the conductive support 1, for example, aluminum, nickel, zinc, platinum, gold, stainless steel, brass, iron, palladium, etc. can be used.

Charge transport layer 106 is provided on charge generation layer 102 or conductive support 101 . Examples of the charge transport substance include carbazole derivatives, pyrazoline derivatives, triphenylamine, hydrazone derivatives, polyvinylpyrene, polyvinylanthracene, and polyvinylacridine. These charge transport materials can be used alone or in combination of two or more. As the binder resin used for the charge transport layer 106, polymers such as acrylic resin, polystyrene, polyester, polyarylate, polysulfone, and polycarbonate can be used. At this time, the ratio of the charge transport material to the binder resin is 150% by weight or less.

〔Example〕

Hereinafter, the electrophotographic photoreceptor of the present invention will be described in more detail based on Examples.

Example 1 1 mm□l of azo compound 1 in which R1, R2, R3, and R4 are hydrogen atoms and R5 is a methyl group in the general formula (III)
and 3,4-dihydroxy-3-7cloftene-1,2
- Dione Q, 5 mm□ 1 in benzene 10 ml. n-
Butano-/l/125 from 120°C in 20 ml
The reaction was carried out at ℃ for 15 hours, and the water produced during the reaction was azeotropically distilled off. The generated precipitate was collected by filtration to obtain 0.095.9 of a squareium pigment represented by the following structural formula. The results of elemental analysis of this product are shown in Table 1.

Table 1 Examples 2 to 25 The reaction was carried out in the same manner as in Example 1 except that the azo compound was changed.
Squareium pigments 2 to 25 whose substituents R1, R2, R3, R4, and R5 are shown in Table 2 were obtained. The yields of these squareium pigments are shown in Table 3, and the results of elemental analysis are shown in Table 4.

Table 2 (Part 1) Table (Part 3) Table (Part 2) Table (Part 1) (Part 3 Table (Part 2) Example 26 5% by weight cyclohexanone solution of polyester resin, 2
9m/! 0.48 mmol of the Squarium pigment synthesized in Example 1 was added to the mixture, and this was dispersed while being pulverized in a paint conditioner for 1 hour.

Next, this was applied onto an aluminum substrate using an applicator to form a charge generation layer having a thickness of 0.3 μm to 160 μm.

100% by weight of para-diethylaminobenzaldehyde diphenylhydrazone was added to a polycarbonate resin, and this was applied onto the charge generation layer to form a charge transport layer with a thickness of 20 μm. Discharge was carried out for 2 seconds using laminated electrophotography, and then in the dark. Leave it for 2 seconds, and the surface potential at that time ■. was measured. Next, use a tungsten-halogen lamp with an illuminance of 5 lu.
When the photosensitive layer is irradiated with x light, its surface potential becomes ■. 1
The time (seconds) required to reach /2 was measured, and the half-reduction exposure amount E1/2 was determined. As a result, the surface potential■. is -650
V, and the half-reduction exposure amount E1/2 was 3.41 ux·sec.

Examples 27 to 50 Laminated electrophotographic photoreceptors were prepared using the squareium pigments synthesized in Examples 2 to 25 in the same manner as in Example 26, and their electrical properties were measured. The results are shown in Table 5.

Table 5 (Part 1) Examples 51 to 75 Paradiethylaminobenzaldehyde diphenylhydrazone was added to polycarbonate resin in an amount of 100% by weight, and this was applied onto an aluminum substrate to form a charge transport layer with a thickness of 20 μm.

Polyester resin cyclohexanone solution 5% by weight, 2
0ml of the squareium pigment synthesized in Example 1.
, 4 g mm□J was added, and this was dispersed while being crushed with a paint conditioner. Next, this was applied onto the charge transport layer using an applicator, and the film thickness ranged from 0.3 μm to 1.0 μm.
A charge generation layer with a thickness of μm was formed to produce a laminated electrophotographic photoreceptor.

Next, the electrical characteristics of this photoreceptor were measured in the same manner as in Example 26. The results are shown in Table 6.

In addition, Squarium pigment 2 synthesized in Examples 2 to 25
Electrophotographic photoreceptors of Examples 1 to 25 were also produced in the same manner as in Example 51, and their electrical characteristics were measured. Table 6 shows the results.
Shown below.

(Part 2 (Part 1 Table 6 (Part 2)) Example 76 The electrophotographic photoreceptor produced in Example 26 was coated with a wavelength of 450 nm.
m, 550nm, 650nm, 750nm, 850nm
When each monochromatic light was irradiated with 1 μW/cII and the half-life exposure amount E1/2 was determined, the results shown in Table 7 were obtained. As can be seen from Table 7, the electrophotographic photoreceptor of the present invention has sufficient spectral sensitivity in a wide wavelength range.

Table 7 Wavelength (nm) 50 50 50 50 50 [Effects of the Invention] The electrophotographic photoreceptor of the present invention can be used in all currently used electrophotographic processes, and has wavelengths from the visible region to the near-infrared region. It has sufficient spectral sensitivity in a wide wavelength range.

[Brief explanation of drawings]

FIGS. 1 to 3 are cross-sectional views of the electrophotographic photoreceptor of the present invention. 101... Conductive support, 102... Charge generation layer, 106... Charge transport layer, 104... Photosensitive layer.

Claims (1)

[Claims] An electrophotographic photoreceptor characterized by containing a squarium pigment represented by the general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (However, in the formula, R_1, R_2, R_3, R_4, R_5
is a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an alkoxy group, an amino group, an aryl group,
Represents a heterocyclic group or a hydroxyl group. )