JPS5831341A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor having high sensitivity and high durability, by providing a photosensitive layer containing a specified trisazo pigment. CONSTITUTION:An intended electrophotographic receptor is obtained by adding to a photosensitive layer at least one of trisazo pigments having general formulaIin which R5, R6 are halogen, alkyl, alkoxy, nitro, or hydroxy; Cp has formulae II, III, IV; X is an atomic group necessary to complete an aromatic hydrocarbon or hetero ring; R1 is H or alkyl; R2 is alkyl; R3, R4 are alkyl, alaralkyl, or aryl. A trisazo pigment of formulaIis obtained by hexaazotizing 4,4', 4''-triamino-triphenylamine, and coupling it with a corresponding coupler in presence of alkali. The trisazo pigment is used for the charge generating layer of a photosensitive layer, alone or in combination with another charge generating material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a specific trisazo pigment.

Conventionally, as electrophotographic photoreceptors made of inorganic photoconductive materials, those using selenium, cadmium sulfide, zinc oxide, etc. have been widely used.

On the other hand, electrophotographic photoreceptors made of 43 photoconductive materials include photoconductive polymers such as poly-N-vinylcarbasol and 2,5-bis(P-di nophenyl)-1,3,4-#-? Electrophotographic photoreceptors using organic photoconductive substances are known, including those using low-molecular organic photoconductive substances such as Nasiazole, and those made by combining these organic photoconductive substances with various dyes and pigments. Because it has good film forming properties and can be produced by coating, it has extremely high productivity and can provide a low-cost photoreceptor.The color sensitivity can be adjusted freely by selecting the dye-pigment type sensitizer used beforehand. It has the advantage of being able to control
However, there is a difference in sensitivity, durability, etc.

Only a few have been put into practical use so far.

The first object of the present invention is to provide an electrophotographic photoreceptor containing a specific trisazo pigment, the second object is to provide an electrophotographic photoreceptor with high sensitivity, and the third object is to provide an electrophotographic photoreceptor with high durability. The purpose of the present invention is to provide a photographic photoreceptor.

This object of the present invention is achieved by an electrophotographic photoreceptor having, as a photosensitive layer, a layer containing at least one trisazo pigment represented by the following general formula CD.

General formula [I] 6 In the formula, R1 and
Examples include a methyl group (1-ethyl group, 1-ethyl group, butyl group, etc.), an alkoxy group (eg, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), a nitoxy group, or a hydroxyl group.

Herogen atoms such as iodine atoms, alkyl groups such as methyl groups, ethyl groups, propyl groups, butyl groups, adenyl groups, 2-
Hydroxybutyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 2-chloroethyl group, 3-hydroxybutyl group, 3-methoxyethyl group, 3-ethoxyethyl group, 4-hydroxybutyl group, 4-methoxybutyl group Substituted alkyl &, alkoxy groups such as methoxy, ethoxy, globoxy, butoxy groups, 1 acetyl &
, a globionyl group, a butyryl group, a benzoyl group, a trioyl group, and the like. A benzene ring is an aromatic hydrocarbon ring.

Examples of the naphthalene ring and heterocycle include an indole ring, a benzifine ring, and a carbazole ring. (2) R1 represents a hydrogen atom or an alkyl group; As a specific alkyl group.

methyl group, ethyl group, n-propyl group, n-butyl group, n-7mil group, n-hexyl & m-octyl group, etc. are preferable. 1 ethyl group, propyl group, butyl group, adentyl group, 3-chloropropyl group, 3
-methoxypropyl group, 3-ethoxypropyl group, 3-
hydroxypropyl group, 4-methoxybutyl group, 4-ethoxybutyl group, 4-hydroxybutyl group), substituted or unsubstituted aralkyl group (e.g. benzyl group,
7enethyl group, chlorobenzyl group, dichlorobenzyl L
) dichloropenzyl group, methoxybenzyl group, acetylbenzyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.) or substituted or unsubstituted aryl group (e.g., phenyl group, tolyl group, xylyl group, biphenyl group, Chlorophenyl group, dichloro-7-menyl group, hydroxyphenyl group.

(chlorophenyl group, methoxyphenyl group, dimethoxyphenyl group, α-naphthyl group, β-naphthyl group, etc.).

Representative examples of the trisazo pigment represented by the general formula (1) are as follows.

trisazo pigment Mu am C electric Ha The trisazo pigment represented by the general formula (2) is.

% 41,411-to-9 acenotol is converted into hexazotin by a conventional method, and then the corresponding hexazonium salt is coupled in the presence of an alkali, or the hexazonium salt of the above-mentioned top electron is converted into hexazonium by a conventional method. Once isolated in the form of a salt or double salt of zinc chloride, etc., it is dissolved in a suitable solvent such as N,
It can be easily produced by coupling it with cup two in the presence of alkashi in a solvent such as N-dimethyl ester, trisulfonate, etc. 0 Synthesis example (for the above-mentioned trisazo pigment layer (1)) showing the synthesis method for the example
77
．． 25 F (0,025 70% water 63% t% concentrated hydrochloric acid 1
Add 3.54 t (0,OS 1-w) of sodium nitrite to a solution dissolved in 3.24 L (o, is 70) and add 10.
Dissolve the liquid in 6m and keep the liquid temperature at 4.5 to 7℃ for 5 minutes.
Drips in minutes.

Thereafter, the mixture was stirred for 30 minutes at the same temperature to give 16.08 f (0,080-v) of s-hydroxy-naphthalene-2-carboxylic methylamide.
+) and gastric soda22. The hequinazation solution was added dropwise over 10 minutes to a solution prepared by dissolving 0.55% of water in 420°C of water while keeping the temperature at 4 to 10°C, stirred at the same temperature for 2 hours, and left overnight.

After passing through the mouth, washing with water, and drying, use 1/2 methyl ethyl lactone.
2. Dry pigment 1971 was obtained by applying Soxhlet K for o hours.

Yield: s5- Elemental analysis: Molecular formula CMN1@)- Calculated value (to) Analysis value (4) C69,9869,88 H4,544,57 N l&12 15.09 Other trisazo pigments used in the present invention are also completely It can be synthesized in the same manner. An electrophotographic photoreceptor containing an organic pigment on a conductive layer is as disclosed in Japanese Patent Publication No. 52-1667, in which a layer in which pigments are dispersed in a binder is provided on the conductive layer. O ■ Hours and minutes 1847-18545% JP-A-4Q-AOAZS
#A layer in which KjlI family is dispersed in a charge transporting material consisting of a charge transporting material or a nuclear material and an insulating binder (the binder itself may be a charge transporting material) as disclosed is provided on a conductive layer. thing.

@4? 1849-105537, comprising a thin conductive layer, a charge generation layer containing an organic pigment, and a charge transport layer.

■ There are charge transfer complexes in which an organic pigment is added to a charge transfer complex as disclosed in US Pat. Although this invention can be applied to any type of electrophotographic photoreceptor having such characteristics, the present invention can be applied to any type of electrophotographic photoreceptor having such characteristics.

It is desirable to use it as a type of photoreceptor.

Furthermore, the characteristics of the 90-type photoreceptor are explained in detail by separating the charge carrier generation function and the transport function.

The layer structure requires a conductive layer, a charge generation layer, and a charge transport layer, and the charge generation layer may be either above or below the charge transport layer, but in electrophotographic photoreceptors of the type that are used repeatedly, it is mainly An adhesive layer can be provided as necessary for the purpose of improving adhesion with the conductive layer, charge generation layer, and charge transport layer from the viewpoint of physical strength and, in some cases, chargeability.

As the conductive layer, a metal plate or metal foil such as aluminum,
A plastic film or aluminum foil laminated with paper on which a metal such as Al<=cum is vapor-deposited, or paper treated with conductive treatment is used.

Resins such as casein, polyvinyl alcohol, and water-soluble ethylene-acrylic acid copolymer nitrocellulose are effective materials for the adhesive layer.The thickness of the adhesive layer is 0.1 to 5.
μ, preferably 0.5 to 3 μ is appropriate.

Place one grain on top of the conductive layer or the adhesive layer applied to the conductive layer.
After the trisazo pigment represented by is made into fine particles, it can be prepared without a binder or, if necessary, by dispersing it in a suitable binder solution and applying and drying it.
When dispersing the trisazo pigment, a known method such as a Hiro ball mill or attritor can be used, and pigment particles of 5 μm or less can be used.
Hereinafter, the thickness is preferably 2μ or less, optimally 0.5μ or less◇ The trisazo pigment can also be applied by dissolving it in an amine solvent such as ethylenediamine.

Conventional methods such as blade, Mayer bar, spray, and dipping methods are used for application.

The thickness of the charge generation layer is 5μ or less, preferably 0.01 to 1
μ is desirable @ When a binder is used in the charge generation layer, a large amount of binder will affect the sensitivity.9) The ratio of binder in the charge generation layer is 80 or less, preferably 4
〇- or less is desirable.

The binder used is polyvinylbutytool,
Various resins such as polyvinyl acetate, polyester, polycarbonate, phenoxy resin, acrylic resin, polyacryland, polyand, polyvinylpyridine resin, cellulose resin, urethane resin, epoxy resin, casein, and polyvinyl alcohol are used. A charge transport layer can be provided on the charge generation layer thus prepared.@If the charge transport material does not have film-forming ability, dissolve the binder in a suitable solvent and apply Nine Waves using the usual O method and dry. A method for forming a charge transport layer can be used.

The charge transporting substances include electron transporting substances and hole transporting substances, and the electron transporting substances include chloranil, pulmoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-dolinitro9- fluorenone,
2,4,5.7-tetraetro-9-fluorenone, 2
, 4.7-) Listrow 9-dicyanomethylenefluorenone.

λ4. Examples include electron-withdrawing substances such as 7-teto-2-nitrixanthone and 2,4.8-trinitrothionanthone, and polymerized versions of these electron-withdrawing substances.

Examples of hole-transporting substances include pyrene, N-ethylcarbazole, N-ingrovircarbazole, N-methyl-N
-Phenylhydrazino-3-fif'Jf-9-ethylcarba/-A/,N.

N-') 7s Nylhydrazino-3-methylidene-
9-ethylcarbasol, N,N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N
, N-diphenylhydrazino-3-methylidene-10-
Ethylphenoxazine, P-diethylaminobenzaldehyde-N.

N-diphenylhydrazone, P-diethylaminobenzaldehyde-N-α-su7thi-N-phenylhydrazone% P-pyrrolidinobenzaldehyde-NeN-diphenylhydrazino, 1°3,3-) Limethylindolenine--Aldehyde N , N--) phenylhydrazone, P-1 ethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, etc., λ
5-bis(P-diethylamino-7-monyl)-1,3,4
-Oxadiazole, 1-phenyl-3-(p-diethylaminostyryl)-5-(P-diethylaminophel)pyrazoline, 1-[quinolyl(2)]-3-(
P-diethylaminostyryl)-5-(P-1>ethylaminophenyl)pyrazoline, 1-[pyridyl (2))
-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-(6-medoxybilidyl(2))-3-(P-diethylaminostyryl)-s-(p-diethylaminophenyl ) pyrazoline, l-[pyridyl (8)] -3-(p-diethylaminostyryl-5-(P-diethylaminophenyl)pyrazoline, 1-[levidyl nF 3-(p-diethylaminostyryl)-s-(p-diethylaminostyryl) phenyl)
Hilazoline, l-(pyridyl(2))-3-(P-diethylaminostyryl)-4-methyl-5-(P-diethylamino-7-9-9), 1-[pyridyl(2)
))-3-(CX-Methyl-P-diethylaminostyryl)-5-(P-diethylaminophel) Hilazoline, 1-phenyl-3-(P-diethylaminostyryl)
Pizzolines such as -4-methy#-5-(P-diethylaminophenyl) hilazoline, 1-phenyl-3-(α-benzyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, spiropyrazoline, 2 -(P-diethylaminostyryl)-6-dinithylaminobe/zuoquinazole, 2-(P-diethylaminophenyl)-4-(P-dimethylamino 7enyl)
Oquinazole compounds such as -5-(2-chlorophenyl)ol+t1-ol, 2-(P-diethylanthumethylyl)
Thiazole compounds such as -6-dinithylaminobenzothiazole, triarylmethane compounds such as bis(4-1)ethylamino-2-methylphenyl)-phenylmethane, 1.1-bis(4-N,N -diethylamino-2-methylphenyl)hebutane, 1,1,2,2-tetrakis(
Polyarylalkane such as 4-N,N-dimethylannor-2-methyl7znyl)ethane, triphenyl aquine, poly-N-vinylcarbazole,
There are polyvinylpyrene, polyvinylantothene, polyvinyl acridine, Ne-9-pierf, nylantothene, bire/-formaldehyde resin, and ethylcarbazole formaldehyde resin. The charge transport substance is not limited to those described here, and when used, one type or a mixture of two or more types of charge transport substances can be used.

Charge transport layer OK thickness is 5~30μ, preferably 8~20#
As the binder, acrylic resin, polystyrene, polyester, polycarbonate, etc. can be used.6 As the binder of the low molecular hole transporting substance, hole transporting materials such as polyN-vinylcarbazole as mentioned above can be used. USP 41221 can be used as a binder for low-molecular electron-transporting substances.
Electron-transporting substances like those shown in 13! - can be used.

When using a round photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, and the charge transport material is an electron transport material, is it necessary to positively charge the surface of the charge transport layer? When exposed to light after being charged, good electrons are generated in the charge generation layer in the exposed area and injected into the charge transport layer, and then reach the surface and neutralize the positive charge, causing a decrease in surface potential and static electricity between the exposed area and the unexposed area. A visible image is obtained by developing the electrostatic latent image created in this way with a negatively charged toner.This can be fixed directly or the toner image can be transferred to paper, plastic film, etc. After that, it can be developed and fixed.

Alternatively, the electrostatic latent image on the photoconductor may be transferred onto an insulating layer of transfer paper, then developed and fixed. Any of these may be adopted, and the material is not limited to a specific one. On the other hand, when the charge transport material is made of a hole transport material, it is necessary to negatively charge the surface of the charge transport layer, and after charging, When exposed to light, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area, and after reaching 1 mK, the negative charge is neutralized, and the surface potential is attenuated, causing static electricity between the exposed area and the unexposed area. During zero development, where contrast occurs, it is necessary to use a positively charged toner, contrary to the case where an electron transport substance is used.・■ type photoreceptors use an insulating binder like the one used in the charge transport layer of type ■ type photoreceptors. The trisazo pigment represented by the general formula (1) is added to a solution, and after being dispersed, the pigment is coated on a conductive support and dried. The ◇ ■ type photoreceptor is obtained by adding the trisazo pigment represented by the general formula (1) to the charge transport material and charge transport layer of the ■ type photoreceptor. After dissolving the insulating binder to be used in a suitable solvent, adding the trisazo pigment represented by the general formula 〇〕 and dispersing it once, it is obtained by coating it on a conductive support and drying it.

When the electron transporting material and hole transporting material described in the ■type photoreceptor are combined, a charge transfer complex is formed in the ■type photoreceptor. It is obtained by adding a pigment, dispersing it, coating it on a conductive support and drying it.

In any O photoreceptor, the pigment used contains at least one type of pigment selected from trisazo pigments represented by the general formula [0], and if necessary, pigments with different light absorptions are used in combination. A combination of two or more types of trisazo pigments represented by the general formula 〇〕 for the purpose of obtaining a panchromatic photoconductor with increased chromatography, or a combination with a charge generating material selected from known dyes and pigments. It is also possible to do so.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in a wide range of electrophotographic applications such as laser printers and CRT printers.Next, the present invention will be explained according to examples.

Example I A polyvinyl alcohol aqueous solution was applied on an aluminum plate with a thickness of 100μ and dried to form an adhesive layer with a coating weight of 0.8f/♂.
9.000-Solid content 20-1 US Depon Co., Ltd. 1l) to
Trisazo pigment 5f of the above-mentioned pigment A (i) is dispersed in a solution prepared by dissolving Pigment A (i) in 80 m of tetrahydrofuran, and this dispersion is applied onto the adhesive layer, and the coating amount after drying is 0.20 fltl. Nine charge generation layers were formed.

Next, 1-[pyridyl(2))-3-(p-diethylaminostyryl)-s-(p-diethylaminophenyl)pyrazoline 5f and polymethyl methacrylate resin (
Number average molecular weight 100,000) 5t.

An electrophotographic photoreceptor was prepared by dissolving Benyne in 70 Mlll and coating it on the charge generation layer to form a charge transport layer with a coating weight of 10 f/rl after drying. Using an electrostatic copying paper tester Model 18P-428 manufactured by Kawaguchi Electric Co., Ltd., the sample was corona charged at θ5 KV using a static method, held in a dark place for 10 seconds, and then exposed to light at an illuminance of 5 Lux to examine the charging characteristics.

The initial potential is Me (V), the potential retention rate for 10 seconds in the dark is Rv@, and the half-decay exposure amount is El/2 (tux-sec).
The charging characteristics of each photoreceptor were investigated, and the results are shown in Table 1.

Table 1 Vo: -580 volts Rma! 90'
$ El/2: 4.3 Lux-aec Example 2 On the charge generation layer prepared in Example 1, 2.4°7-)
IJ nitro-9-fluorenone 5f and poly-4,4'-
A coating solution was prepared by dissolving 5 f of dioxydiphenyl-2,2'-propane carbonate (molecular weight 300,000) in 70 m of tetrahydrofurin so that the coating amount after drying was 1 Of/l/. Apply and dry.

The electrostatic charge of the electrophotographic photoreceptor thus prepared was measured in the same manner as in Example 1. At this time, the charging polarity was set to ■. The results are shown in Table 2. Vo: 1490 Volts R: 83- El/2: 11.5 Lux-see4 Examples 3 to 4 Coating polyvinyl alcohol aqueous solution on the aluminum surface of the aluminum vapor-deposited Mylar film Dry coating amount 1.2f/II/
After forming an adhesive layer and dispersing 5f of each trisazo pigment shown in Table 3 below and 2t of butyral resin (butyralization degree 63molts) in 959ILt of ethanol using the 90 method, the aluminum of the aluminum-deposited Mylar film was dispersed. Apply in a diagonal direction, and after drying, the coating amount is 0.2 f/I! Nine charge generation layers were formed.

Next, 1-7-2-3 (P-diethylaminostyryl)
-5-(P-diethyaminophenyl)pyrazoline 5F,
The polycarbonate tree yxtst used in Example 2 was dissolved in 70 flLt of tetrahydrofuran, and a liquid absorbent solution was applied onto the charge generation layer and dried to form a charge transport layer with a coating weight of 11 f/rl.

The electrostatic charge of the photoreceptor thus prepared was measured in the same manner as in Example 1, and the results are shown in Table 3. Apply the aqueous solution and dry it, coating amount: 1. Form an adhesive layer of/wl and form a circle.

Next, 2-(P-diethylaminophenyl)-4-(P-
dimethylaminophenyl)-S-(2-chlorophenyl)oxazole 5f and poly-N-vinylcarbazole 5
f (a average molecular weight 300,000) was converted into tetrahydrogen 70fI
Pigment 1 (1) was added to the LtK solution. The dispersion was coated on the adhesive layer and dried, and the coating amount was adjusted to llf.
// Toshiku The photoreceptor thus prepared was used in conjunction with Example 1 to perform charge measurement, and the measured values were as follows.

However, the charging polarity was set to 0. The results are shown in Table 4.

Table 4 V (1: 1540 volts Rv: 84 chi F217/'2: IQ, 3tux-s+ac
Patent applicant Canon Co., Ltd. Kinsha Fupia Co., Ltd.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising a layer containing at least one trisazo pigment represented by the following general formula. General formula ■ Bird & (In the formula, Rs and 4 are hydrogen atoms)・Rogen atom,
Al, alkoxy, and nitro groups are water 11I&
O H 1 t-friend indicates number 1. However, X is substituted or unsubstituted '1P4r-
Indicates the atoms necessary to complete a group hydrocarbon group or a substituted or unsubstituted heterocycle. The tortoise indicates a hydrogen atom or an alkyl group, and the octad indicates an alkyl group. Turtle and melon represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heptadyl group. )