JPS5843458A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor of high sensitivity and high durability by adding a specified anthraquinone monoazo pigment to a photoconductive layer. CONSTITUTION:To a photoconductive layer is added >=1 kind of monoazo pigment represented by formulaI[where X is a (substituted) aromatic hydrocarbon ring or an atomic group required to complete a (substituted) heterocyclic ring, R1 is H or alkyl, R2 is alkyl, and each of R3 and R4 is (substituted) alkyl, (substituted) aralkyl or (substituted) aryl]by dispersing the pigment in the charge transferring medium consisting of a charge transferring substance and a binder, or the pigment is added to a charge generating layer as a charge generating agent and a charge transferring layer is formed on the charge generating layer. Thus, an electrophotographic receptor high sensitivity and high durability is obtd.

Description

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

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

On the other hand, electrophotographic photoreceptors made of organic photoconductive materials include photoconductive polymers such as polyN-vinylcarpasolini, 2,5-bis(P-diethyl72nophenyls)-1,3, Those using a low-molecular organic photoconductive substance such as 4-oxadiazole, and those using a combination of a ζ-stripped photoconductive substance and various dyes and pigments are known.

An electrophotographic photoreceptor using a grown photoconductive material has good film forming properties and can be produced by coating, so it is possible to provide an extremely highly productive and inexpensive photoreceptor. Further, it has the advantage that color sensitivity can be freely controlled by selecting the sensitizing agent such as a dye or pigment to be used, and a wide range of studies have been made to date.

However, there are problems with sensitivity, durability, etc., and so far only a few have been put into practical use.

The purpose of the present invention is to provide an electrophotographic photoreceptor containing a specific monoazo pigment.Secondly, it is an object of the present invention to provide an electrophotographic photoreceptor with high sensitivity, and thirdly, to provide an electrophotographic photoreceptor with high durability. An object of the present invention is to provide an electrophotographic photoreceptor. -1 1 The present invention 0 or 2'91 Gosukuney 1 [(I) The low content of the monoazo pigment shown is also achieved by an electrophotographic photoreceptor having a layer containing IS as a photosensitive layer.

General formula (1) is shown, and the ring is a chlorine atom, a bromine atom, an iodine atom, etc., an alkyl group such as a methyl group, an ethyl group, a propyl group, a methyl group, an amyl group, 2=hydroxyethyl group, 2-meth)dtV: rf group, 2-ethoxyethyl group, 2-chloroethyl group, 3-hydroxyg. Substituted alkyl groups such as pyru group, 3-methoxypropyl group, 3-ethoxyethyl group, 4-hydroxybutyl group, 4-methoxybutyl group, alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, acetyl group , a globiodyl group, a butyryl group, a benzoyl group, a trioyl group, and the like. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and examples of the heterocycle include an indole ring, a benzofuran ring, and a carbazole ring.

al represents a hydrogen atom or an alkyl group, and bird represents an alkyl group; specific alkyl groups; 1 represents a methyl group, ethyl group, n-propyl group, n-butyl group, 11-amyl group, 11-hexyl group; s, n-octyl group, etc. are preferred.

R3 and R4 are substituted or unsubstituted alkyl groups (
For example, methyl group, ethyl group, propyl group, butyl group, aryl group, 2-chloroethyl group, 2-methquinethyl group, 2-ethoxyethyl group, 2-hydroxyethyl group, 3-chloropropyl group, 3- Methoxypropyl group, 3
-ethoxyethyl group, 3-hydroxyethyl group, 4-methoxybutyl group, 4-, ethoxybutyl group, 4-hydroxybutyl group, etc.), substituted or unsubstituted aralkyl & (yll, for example, benzyl group, phenethyl group, 04-benzyl group, dichlorobenzyl group, trichlorobenzyl group, methoxybenzyl group, acetylbenzyl group, -1-naphthylmethyl group, β-naphthylmethyl group, etc.) or substituted or unsubstituted rearyl group (e.g. , phenyl group,
Tolyl group, xylyl group, biphenyl group, chlorophenyl group, dichlorophenyl group, hydroxyphenyl group, cyanophenyl group, methoxyphenyl group, dimethoxyphenyl group, α-naratyl group, β-naphthyl group, etc.).

Representative examples of monoazo pigments represented by the general formula CI) are:
It is as follows. - Monoazo pigment Δ6 C,H.

(CHi) 5oct+.

(21) C Yu H.

(CH2) 10CsHi.

These monoazo pigments are produced by diazotizing α-aminoa/traquinone or β-aξnoanthraquinone in a conventional manner and then coupling the corresponding coupler in the presence of an alkali. After one day of isolation in the form of a borofluoride salt or zinc chloride double salt, the coupler and the coupler are isolated in the presence of an alkali in a suitable solvent such as N,N-dimethylformane, dimethyl sulfoxide, etc. It can be easily manufactured by forming a ring.

As for representative examples of monoazo pigments used in the present invention,
The synthesis method is shown below.

Synthesis example (regarding the monoazo pigment/% (1) of the above example) α-75 noanthraquinone 5.58 g (0,025
mol) of water 64 m/, salt production'IQ, 13.24
ml (0.15mol; L-), add nitrous acid □
'; Soy meat 3.54 g (0,051 mol) water j0
．． Liquid treasure dissolved in 6m/, liquid temperature 4.・It was kept at 5-7°C and added dropwise from the surface over 5 minutes, and then stirred at the same temperature for 30 minutes.

Next, 4 to 4 g of liquid alcohol was added to a solution in which 5.63 g (0.028 mol) of 3-hydroxy-naphthalene-2-carboxylic acid methylamide and 12.8 g (0.32 mol) of caustic soda were dissolved in 420 m/ml of water. The above tetrazotized solution was added dropwise over 10 minutes while maintaining the temperature at 10°C, and the mixture was stirred for 2 hours at the same temperature.
I installed a 1M device.

After retreating, washing with water and drying, Soxhlet was applied for 2.0 hours using meglyethyl ketone to obtain 9.2 g of dry pigment.

Yield: 85% Elemental analysis: Molecular formula
Calculated value (e) Analytical value ■ C71,72,71,78 ) -13,903,87 N 9.66 9.71 The deaf monoazo pigment used in the present invention can be synthesized in exactly the same manner.

24 As an electrophotographic photoreceptor containing an organic pigment on one layer, ■ K on a conductive layer as disclosed in Japanese Patent Publication No. 52-1667.
A layer in which a JLL material is dispersed in a binder is provided.

■Special Publication fB47-18545, Japanese Patent Publication No. 47-30328
A layer in which a pigment is dispersed in a charge transporting medium consisting of a charge transporting substance or a roaring substance and an insulating binder (the binder itself may be a charge transporting substance) as disclosed in , is provided on the conductive layer. Something.゛■A conductive layer as disclosed in JP-A No. 49-105537,
Consisting of a charge generation layer and a charge transport layer containing organic pigments.

(2) There is one in which an organic pigment is added to a surface charge-transfer complex disclosed in JP-A No. 49-91648.

The electrophotographic photoreceptor of the present invention is characterized by containing a monoazo pigment represented by the general formula '[l], and can be applied to any type of electrophotographic photoreceptor having such characteristics. In order to increase the transport efficiency of charge carriers generated by light absorption of the monoazo pigment represented by the general formula CI), it is desirable to use it as a photoreceptor of type (1), (2), or (3). More charge j! The type of photoreceptor is most desirable in order to take advantage of the characteristics of the penultimate pigment.

Therefore, this type 2 electrophotographic photoreceptor will be explained in detail.

The L- structure requires a conductive layer, a charge generation layer, and a charge transport layer, and the charge generation L- may be located either above or below the charge transport layer, but in an electrophotographic photoreceptor of the type that is repeatedly used. Mainly from the viewpoint of physical strength, and in some cases from the viewpoint of chargeability, conductive layers, charge generation layers,
An adhesive layer can be provided as necessary for the purpose of improving adhesion to the charge transport layer.

As a conductive layer, a metal plate such as aluminum or a metal foil,
・Glassic film with metal such as aluminum vapor-deposited or aluminum foil glued to paper, -
Paper or the like that has been subjected to a certain treatment is used.

Contact! Effective materials for + and - include resins such as casein, polyvinyl alcohol, water-soluble ethylene-acrylic acid copolymer, and trocellulose. The thickness of the adhesive 1- is suitably 0.1 to 5 microns, preferably 0.5 to 3 microns.

On the conductive layer or the adhesive layer applied to the conductive layer = general formula (I
) After the monoazo pigment shown in ) is made into fine particles, it can be dispersed in a suitable binder solution without a binder or, if there is a concern, and then coated and dried to form particles.

When dispersing the monoazo pigment, known methods such as ball milling and attritor can be used, and it is desirable that the pigment particles be 5 μm or less, preferably 2 μm or less, and optimally 0.5 tones or less.

The monoazo pigment can also be applied by dissolving it in an amine solvent such as ethylene cyanide.

Conventional methods such as spraying, spraying, dipping, etc. can be used as the coating method.

・ ・, jl: 1・, 1 The thickness of the charge emitting layer is 5 μ or less, preferably 0.01;
1μ is desirable. When a binder is used in the charge generation layer, a large amount of binder will affect the sensitivity, so the proportion of the binder in the charge generation layer is preferably 80 φ or less, preferably 40 qb or less.

The binder used is polyvinyl butyral,
Polyvinyl acetate, polyester, polycarbonate, phenoxy resin, acrylic resin, polyacrylamide,
Polyamide, (1) vinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, etc. are used.

S! established in this way! A charge transport layer can be provided on the charge generation layer. If the charge transport material does not have the ability to form a film, a charge transport layer can be formed by applying and drying a solution prepared by dissolving Ingu in a suitable solvent using a conventional method.
I can do that.

Charge transport-121 substances include electron-transporting substances and hole chloranyl, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-dolinitro9-
Fluorenone, 2.4.5.7-tetranitro-9-fluorenone, 2.4.7-)nitro-9-dicyanomethylenefluorenone, 2,4.5. Examples include electron-withdrawing substances such as tutetranitroxanthone and 2,4.8-trinidrothioxanthone, and polymerized versions of these electron-withdrawing substances.

Examples of hole-transporting substances include pyrene, mono-ethylcarbazole, and N-isopropylcarno(so-methylidene-
9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole% N
*N-diphenylhydrazino 3-methylidene-10-
Ethylphenothiazine, N,N-9 phenylhydrazino-3-methylidene-1O-ethylphenoxazine, P-
Diethylaminobenzaldehyde N, N-diphenylhydrazo/, P-diethylaminobenzaldehyde-N
-α-naphthyl-N-phenylhydrazone, P-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, 1.3.3-) Limethylindolenine--aldehyde N, N-diphenylhydrazone P-diethylbenzaldehyde-3 -hydrazones such as methylbenzthiazolinone-2-hydrazone, 2,5-his(P-diethylaminophenyl)-1,
3,4-oxadiazole, 1-phenyl-3-IP
-diethylaminostyryl>-5-(p-"diethylaminophenyl)pyrazoline, 1-[quinolyl (2))
-3-(P-diethyl iinostyryl)-5-(P
-diethylaminophenyl)pyrazoline, 1-(pyri,
(2) -3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline,
1 (6-medoxypyridyl (2) ) -3-(
P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazolihene, 1-[pyridyl (3)]
-3-(P-diethylaminostyryl)-S-(P-diethylamino-7enyl)pi9 SoIJn, 1-(vWtsu, 1(2)]-3yu.Poni, f9a57styryl) -5
-(P-diethylamino7enyl)pyrazoline, -1-
(pyridyl(2)) -3-(P-diethylaminostyryl)-4-methyl-5-(1'-diethylaminophenyl)pyrazoline, 1-(pyridyl(2)) -
3-(α-methyl-P-diethylaminostyryl)-
5-(P-diethylamino7enyl)pyrazoline, 1-
Feni-3-(P-diethylaminostyryl)-4-
Methyl-5-(P-diethylaminophel) bira/I
J-n, l-7enyl-3-(α-benzyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, pyrazolines such as suzerovirazoline, 2-pa(P-diethylaministyryl) -6-- )
Ethylaminobenzoxazole, 2-(P-,>tauthyl adenophenyl')-4-(P-diethylaminophenyl)-5-(2-/lorphenyl)oxazole-
Oxazole compound, 2-. '11 To hardware, triarylmethane compounds such as bis(4-diethylamino-2-methylphenyl)-phenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl) Butane, 1.1.2.2-tetrakis (
4-N,N,-dimethyhairmino-2-methylphenyl)
Polyarylalkanes such as ethane, triphenylamine, poly-N-vinylcarbasol,
Examples include poly-1 vinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, and ethylcarbazole formaldehyde resin. Charge transport materials are not limited to those listed here, but when used, one or two types of charge transport materials may be used.
It is possible to use a mixture of Class I or more.

The thickness of the charge transport layer is 5 to 3.0μ, preferably -tL, and <8 to 3.0μ.
It is 20μ.

As the binder, acrylic resin, polystyrene, polyester, polycarbonate, etc. can be used. As the binder for the low-molecular hole-transporting substance, a hole-transporting polymer such as the poly-N-vinylcarbazole described above can be used as the binder. On the other hand, 08F412211 is used as a binder for low-molecular electron transporting substances.
Polymers of electron transporting monomers such as those shown in 3 can be used.

When using a photoreceptor in which a charge transport 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, the surface of the charge transport layer must be positively charged. After exposure, nine electrons are generated in the charge-generating layer in the exposed area and injected into the charge-transporting layer, and then reach the surface, neutralizing the positive charge, causing a decrease in the surface potential in the unexposed area. An electrostatic contrast occurs between the two.

The Seidensen Keyaki, which is made like a jin, is agglomerated with a negatively charged toner.
If you image it, you will get a visible image. Fix this directly or
Alternatively, after transferring the donor image to paper, plastic film, etc., it is possible to create a fixed image.

Alternatively, a method may be used in which the electrostatic latent image on the photoreceptor is transferred onto an insulating layer of transfer paper and then fixed thereon. The type of developer, the developing method, and the fixing method may be any known ones or known methods, and are not limited to specific ones.

On the other hand, when the charge transport material consists of a hole transport material, the surface of the charge transport layer must be negatively charged, and when exposed to light after charging, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area. After that, it reaches the surface and neutralizes the negative charge, causing attenuation of the surface potential and creating an electrostatic contrast with the unexposed area. During development, it is necessary to use a positively charged toner, contrary to the case where an electron transport material is used.

The ■ type photoreceptor is made by adding a monoazo pigment represented by the general formula [1] to an insulating pine or goo solution used for the charge transport layer of the type ■ photoreceptor, and then dispersing it into a conductive support. jAll... Obtained by drying the cloth.

The ■ type photoreceptor is prepared by dissolving the charge transport material of the ■ type photoreceptor and the insulating paint used for the charge transport layer in an appropriate solvent, and then forming a mono-exclusive azo-conductor compound represented by the general formula CI). is added, dispersed, and dried on a conductive support using leprosy cloth.

The ■ type of photoreceptor is a combination of the electron transport material and hole transport material described in the photoreceptor in page 9 to form a charge transfer complex. A monograss azo pigment represented by □ is added, dispersed, and then dried at a vehicle height on a conductive support.

In any photoreceptor, the pigment used is of the general formula (1)
A method for increasing the sensitivity of a photoreceptor and obtaining a panchromatic photoreceptor containing at least one type of pigment selected from the monoazo pigments shown in In which case, if the monoazo pigment represented by the formula (1) is used in combination with a cloudy type or more, or in combination with a known dye or pigment or a selected charge generating material. " is also possible.

This invention. , 100 Shinkan Ittai i electronic photography. It can be used not only for multiplex printers, but also for a wide range of electrophotographic applications such as laser printers and CI (T printers).

The present invention will now be explained based on examples.

Example 1 A polyvinyl alcohol aqueous solution was applied onto an aluminum plate having a thickness of 100 μm and dried to form an adhesive layer with a coating weight of 0.8 g/m”.

By the way, polyester adhesion resistant (polyester adhesion 4)
9,000 - solid content 204) +, manufactured by DuPont, USA)
Disperse 5 g of the monoazo pigment of the pigment layer (1) shown in ν1j in a solution in which 10 g of tetrahydrofuran is dissolved in 80 mj of tetrahydrofuran, apply this dispersion liquid on the adhesive layer, and after drying, 0.20 g/rr? A charge generation 1- was formed.

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

was dissolved in 70 mj of benzene and coated on the charge generation layer to form a charge transport layer with a coating weight of 10 g/'' after drying.

The electrophotographic photoreceptor thus prepared was statically charged at 95 KV using Kawaguchi Denki's Shizuki Copying Paper Tester Modej 8F-428, and after being held in a dark place for 10 seconds, the illuminance was set to 5. It was exposed to light using a jux and the charging characteristics were investigated.

The initial potential is Vo (V), the potential retention rate for 10 seconds in the dark is Rv (i, and the half-attenuation exposure amount is E 1/2 (jux, 5
ec), the charging characteristics of each photoreceptor were investigated, and the results are shown in the table.

Table 1 Vo: -560 volts Rv: 90% E: 5.4 jux, sec Example 2 On the charge generation layer prepared in Example 1, a 2.4°7-
) 9nitro-9-fluorenone 5 g yt! 1
)-4,4'-Gio-sidiphenyl-2,2'
- Pu-a-bunk carbonate (300,000 molecular sacs)
5 g of tetrahydrofuran 7. A coating solution prepared by dissolving it in Omj was applied to a coating amount of 10 g/m'' after drying, and then dried.

A photographic photosensitive specimen of the thus prepared specimen 9 was carried out and #electricity measurement was carried out in the same manner as in 1. At this time, the charge polarity was set to e. The results are shown in Table 2.

Table 2 Vo: +500 volts Rv: 84% g1/2: 12. Otux, sec Examples 3 to 23 A polyvinyl alcohol aqueous solution was applied and dried on the aluminum surface of an aluminum vapor-deposited mylar film, and the coating amount was 1.2 g/rn”
, (D adhesive layer was formed.

A while ago, 5 g of each monoazo family shown in Table 3 below and 2' g of butyral resin (butyralization degree 63 mol 96) were mixed with 95 ml of ethanol to make liquid beef.
,,6″-i “″”.

It was applied to an aluminum surface, and after drying, the coating amount was 0.2 g/m'' to form a nine-density generation layer.

&ni1-phenyl-3(P-diethylaminophenyl)
-5-(P-diethiaminophenyl)pyrazoline 5g1
A solution obtained by dissolving 5 g of the polycarbonate resin used in Example 2 in 70 ml K of tetrahydrofuran was applied onto the charge generating layer M and dried to form a charge transport layer having a coating amount of 1117 m''.

The charging of the photoreceptor thus prepared was measured in the same manner as in Example 1, and the results are shown in Table 3.

Example 24 An ammonia aqueous solution of casein was applied and dried on an aluminum plate having a thickness of 100 μm to form an adhesive layer with a coating weight of 1.0 g/m”.

111KK2-(P-diethylaminophenyl)-4-
(P-Dimethylaminophenyl> -S -(2-Chlorphenyl)oxazole 5g and BoIJ-N-vinylcarbazole 5g (number average molecular weight 300,000) dissolved in 70ml of tetrahydrofuran and 1 of the pigment from scraps (1) .0
g was added, and after dispersion, it was applied and dried on the adhesive layer to give a coating amount of 1117 m''.

The photoreceptor prepared using this strain was subjected to charge measurement in the same manner as in Example 1, and the measured value was as per Hirohisa. However, obi'
The IL polarity was set to e. The results are shown in Table 4.

Dragon 4 Vo: +580 volts Rv:844 El/2: 8.0 lux, 5ec-3';

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising a layer containing at least one monoazo pigment represented by the following general formula (I). General formula [I] Indicates the atomic group necessary to complete the group hydrocarbon ring or substituted or unsubstituted heterocycle. Tortoise indicates a hydrogen atom or a hydroalkyl group, stone indicates an alkyl group, as and Ba, Substituted or unsubstituted alkyl group, substituted or unsubstituted aral, kyl group, or substituted or unsubstituted aryl group)