JPS60454A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body high in sensitivity and long in life by laminating an electrostatic charge generating layer contg. a specified disazo compd. as a charge generating agent, on a charge transfer layer formed on a substrate to form a photosensitive layer, or forming a single photosensitive layer contg. both of said compd. and a charge transfer agent on the substrate. CONSTITUTION:A charge generating layer 22 is formed by applying to a conductive substrate 11 and drying and hardening a coating soln. prepared by dispersing into the soln. of a binder resin a disazo compd. represented by formula I in which Y is a group of formulae II, III, or IV; R1, R2 are each H, lower alkyl, optionally substd. aralkyl, optionally substd. aromatic, or optionally substd. heterocyclic, or they may be same or different, and they may form a ring together with each other. A photosensitive layer 44 is formed by laminating on this layer 22 a charge transfer layer 33 contg. an org. charge transfer agent. Or a single photosensitive layer contg. said charge generating agent and the charge transfer agent may be formed. As a result, the photosensitive body thus obtained is stable in characteristics even after repeated uses and long in life. and has superior durability.

Description

[Detailed description of the invention] Technical field The present invention relates to a photoreceptor for electrophotography.

Prior Art Conventionally, there have been inorganic photoreceptors for electrophotography, such as those using selenium and its alloys, or photoreceptors in which dye-sensitized zinc oxide is dispersed in a binder resin.
Among organic materials, typical ones include those using a charge transfer complex of 2,4,7-dolinitro-fluorenone (hereinafter referred to as TNF) and poly-N-vinylcarnozole (hereinafter referred to as PVK). It is something. However, while these photoreceptors have many advantages, they also have various disadvantages. For example, the currently widely used selenium photoreceptor has difficult manufacturing conditions and high manufacturing costs, is difficult to process into a belt due to its lack of flexibility, and is sensitive to heat and mechanical shock. Therefore, care must be taken when handling. Zinc oxide photoreceptors can be manufactured using inexpensive Rakuhoku zinc by coating them on a support, so the cost is low, but they generally have low sensitivity, poor surface smoothness, hardness, tensile strength,
It has mechanical drawbacks such as abrasion resistance, and as a photoreceptor for plain paper copying machines, which is normally used repeatedly, there are many problems with durability. As mentioned above, a photoreceptor using a charge transfer complex of TNF and PVK has low sensitivity and is unsuitable as a photoreceptor for high-speed copying walls.

In recent years, extensive research has been carried out to eliminate the drawbacks of these photoreceptors, and in particular, a variety of organic photoreceptors have been proposed. Among these, there is a layer containing a substance that generates charge carriers when irradiated with light (hereinafter referred to as charge generation material), and a layer containing a substance (hereinafter referred to as charge generation layer) that generates charge carriers and transports them (hereinafter referred to as charge generation layer). The A1 (layer type photoreceptor), which is composed of a layer mainly containing a charge transport material (hereinafter referred to as a charge transport layer), generally has higher sensitivity and stable chargeability compared to conventional organic photoreceptors. It has attracted attention as a photoreceptor for plain paper copying machines due to its high sensitivity, and some are in practical use.

This type of conventional laminated photoreceptor includes (1) a thin layer of a vacuum-deposited perylene derivative as a charge generation layer and an oxadiazole derivative as a charge transport layer (see U.S. Pat. No. 3,871,882); ), (2) A thin layer formed by coating an organic amine solution of chlordian blue as the charge generation layer and a hydrazone compound used as the charge transport layer (Japanese Patent Publication No. 55-423
80), etc. are known.

However, it is true that conventional laminated photoreceptors of this type have many advantages, but also have considerable disadvantages.

The photoreceptor using the perylene derivative and oxadiazole derivative shown in (1) has a high manufacturing cost because its charge generation layer is formed by vacuum deposition. Further, even if there is no practical problem, there are problems such as insufficient sensitivity as a photoreceptor for higher speed copying machines.

The photoreceptor using chlordiane blue and a hydrazone compound as shown in (2) requires the use of an organic amine (e.g. ethylenediamine), which is generally difficult to handle, as a coating solvent for forming the charge generation layer, which makes it difficult to fabricate the photoreceptor. 0 Purpose The inventor of the present invention took into account the above points and made extensive studies with the aim of developing a photoreceptor that can be easily manufactured and is suitable for repeated use. The present invention was completed based on the knowledge that the object could be achieved.

Structure The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive support, in which the following general formula (1) is represented in the photosensitive layer, and %R1 and 几 are hydrogen, lower represents an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group;
1 may be the same or different. Also turtle and R
1 may jointly form a ring. The disazo compound represented by ] is characterized in that it can be used in a variety of ways.

Among these photoreceptors, a multilayer type photoreceptor is preferred, in which the photosensitive layer is constructed by laminating a charge generation layer and a charge transport layer, and the charge generation layer contains a disazo compound of the general formula (0).

Here, the lower alkyl group in general formula 〇) is
Examples of aralkyl groups include benzyl and phenethyl groups; aromatic groups include phenyl, naphthyl, anthryl, pyrenyl, and anthraquinonyl groups; heterocyclic groups include methyl, ethyl, and propyl groups; Examples include a chenyl group, a furyl group, a pyridyl group, and a carbazolyl group, and examples of the ring formed by R and R include a hexylidene ring, a pentylidene ring, a benzopentylidene ring, and a dipenzopentylidene ring. Examples of substituents in aralkyl groups, aromatic groups, heterocyclic groups, and apes formed with - include lower alkyl groups, lower alkoxy groups, halogen atoms, cyano groups, nitro groups, and lower dialkylamino groups. .

The present invention will be explained in more detail below.

First, specific examples of the disazo compound used in the present invention are as follows.

The above disazo compounds include 2.2'-diaminostilbene, 2,3'-diaminostilbene, 2+eediaminostilbene, 3.eediaminostilbene or 4,4'
- Diaminostilbene is converted into a diazonium salt according to the diazotization method described in JP-A-52-8832 or JP-A-54-20737, and the corresponding 2
- Hydroxy-3-naphthoic acid hydrazides, for example, N,N-dimethylformamide (D
It can be easily produced by performing a coupling reaction with a base in MF).

Although the charge transporting substance used in the present invention is not specified, typical examples thereof are as follows.

几10 [几1) Alkyl groups such as mamethyl group and ethyl group, 2-
Bll is a substituted alkyl group such as chloroethyl group or 2-hydroxyethyl group Bll is an alkyl group such as methyl group or ethyl group, aralkyl group such as benzyl group, or aryl group such as phenyl group Blm is a hydrogen atom or a halogen atom such as chlorine or bromine , an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a cytoxy group, a dialkylamino group, or a nitro group. ] [Ar' represents a naphthyl group, an anthryl group, a styryl group, or a substituent thereof. BIN represents an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a ndyl group, or an aryl group such as a phenyl group. Examples of 1Δ substituents in anthryl and styryl groups include:
Examples include alkyl groups such as methyl group and ethyl group, alkoxy groups such as methoxy group and ethoxy group, and dialkylamino groups such as dimethylamino group and diethylamino group. ] Represents an alkyl group such as an ethyl group or a propyl group, an alkoxy group such as a methoxy group, an ethoxy group or a proFI9xy group, a 7% rogen atom such as chlorine or bromine, a nitro group or a hydroxyl group; B111 is a hydrogen atom, a methyl group, Alkyl groups such as ethyl group and propyl group; alkoxy groups such as methoxy group, ethoxy group, and propoxy group; dialkylamino groups such as diethylamino group and diethylamino group;
Diarylamino groups such as dibenzylamino groups, diarylamino groups such as diphenylamino groups, halogen atoms such as chlorine and bromine, nitro groups or hydroxyl groups, and aralkyl groups such as methyl groups, ethyl groups, and alkyl groups. , 0 represents an aryl group such as a phenyl group] [几-Rto, RtI or R1 snow represents a hydrogen atom, a methyl
ano-monokyl groups such as ethyl and propyl groups; alkoxy groups such as methoxy, ethoxy and propoxy groups; dialkylamino groups such as dimethylamino and diethylamino groups; halogen atoms such as chlorine and bromine; Represents a group or a hydroxyl group. ] [R11 is an alkyl group having 1 to 11 carbon atoms, an unsubstituted phenyl group, a substituted or unsubstituted heterocyclic group, Bffi4 or Bll is a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, etc. represents a chloro-substituted alkyl group, a hydroxy-substituted alkyl group, a substituted or unsubstituted aralkyl group, and No. 14 and 几1- may be bonded to each other to form a nitrogen-containing heterocycle. BH
Alternatively, R represents a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an alkoxy group such as a methoxy group or an ethoxy group, or a halogen atom such as chlorine or bromine. Examples of the heterocyclic group of BH include a pyridyl group, a furyl group, a chenyl group, an indolyl group, a pyrrolyl group, a quinolyl group, and a cal/mozolyl group. Examples of substituents on the phenyl group or heterocyclic group of Bll include alkyl groups such as methyl group and ethyl group, and alkoxy groups such as methoxy group and ethoxy group.

Examples of the aralkyl group of Bll or Bll include a benzyl group, and examples of substituents on the aralkyl group include halogen atoms such as chlorine and bromine, alkyl groups such as methyl and ethyl groups, and nitro groups.

几! A morpholine ring is an example of the heterocycle formed by bonding RtI and RtI to each other. ] [RtI is a hydrogen atom, a /'% rogene atom such as chlorine, bromine, R19 is a hydrogen atom, a 10 gen atom such as chlorine, bromine, an alkyl group such as a methyl group, an ethyl group, a methoxy group, an ethoxy group, etc. alkoxy group, dimethylamino group,
Dialkylamino groups such as diethylamino group and dibutylamino group, dialkylamino groups such as dibenzylamino group and chlorine-substituted dibenzylamino group, halogen atoms such as nitro group, cyano group or elemental group, alkyl group such as methyl group and ethyl group represents a group. ] [R11 is a hydrogen atom, a halogen atom such as chlorine or bromine,
Alkyl group such as methyl group, ethyl group, ethyl group, alkoxy group such as methoxy group, ethoxy group, butoxy group or cyano group, Bam or 1pl is hydrogen atom, alkyl group such as methyl group, ethyl group, butyl group, 2 - Substituted alkyl group such as chloroethyl group, 2-hydroxyethyl group, or substituted or unsubstituted benzyl group, Rs4 or Bml is a hydrogen atom, 39- Halogen atom such as chlorine or bromine, methyl group, ethyl group,
Alkyl groups such as ethyl groups, methoxy groups, ethoxy groups,
It represents an alkoxy group such as a butoxy group, or a dialkylamino group such as a dimethylamino group or a diethylamino group. R
Examples of substituents on the benzyl group represented by 1 or R11 include alkyl groups such as methyl and ethyl groups, alkoxy groups such as methoxy and oxy groups, and nitro groups. ] 1: Ar' represents an N-alkylcarbazolyl crystal,
Alkyl groups include methyl group, ethyl group, propyl group,
An example is a butyl group. ] (RN, R″1.R″ is a hydrogen atom, a halogen atom such as chlorine or bromine, a methyl group,
Alkyl group such as ethyl group, alkoxy group such as methoxy group, ethoxy group, nitro group or amino group B 1m
is a hydrogen atom, a halogen atom such as chlorine or bromine, an alkyl group such as a methyl group or an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, a dialkylamino group such as a dimethylamino group, a diethylamino group or a dibutylamino group, or a dibenzyl group. N-alkyl with substituted or unsubstituted dialkylamino groups such as amino group, chloro-substituted dibenzylamino group, methyl-substituted dibenzylamino group, methoxy-substituted dibenzylamino group, N-methyl-N-benzylamino group, etc. -N-Aralkylamino group, carboxy group or its ester, amino group, hydroxy group, cyano group, acetylamino group. ] (B411 represents an N-alkylcal/metazolyl group, a pyridyl group, a chenyl group, an indolyl group, a furyl group, or a substituted or unsubstituted naphthyl group, styryl, or anthryl group, respectively.

Examples of substituents on naphthyl, styryl, and anthryl groups include alkyl groups such as methyl and ethyl groups, alkoxy groups such as methoxy and ethoxy groups, and dialkylamide groups such as dimethylamino and diethylamino groups. ] [几41, Mr. B is a hydrogen atom, a methyl group, an ethyl group,
Alkyl groups such as butyl groups, methoxy groups, ethoxy groups,
It represents an alkoxy group such as a butoxy group, a halogen atom such as chlorine or bromine, or a dialkylamino group such as a dimethylamino group or a diethylamino group. group, alkyl groups such as ethyl groups, alkoxy groups such as methoxy groups and ethoxy groups, halogen atoms such as chlorine, and TL4e are alkyl groups such as methyl groups, ethyl groups, propyl groups, butyl groups, substituted or unsubstituted. an aralkyl group, a substituted or unsubstituted aryl group, and R4 represent a hydrogen atom or a substituted or unsubstituted phenyl group. An example of the aralkyl group is a pencil group, and an example of the aryl group is a phenyl group. In addition, substituents on aralkyl groups or aryl groups include alkyl groups such as methyl, ethyl, and butyl groups, alkoxy groups such as methoxy and ethoxy groups, halogen atoms such as chlorine,
Examples include dialkylamino groups such as dimethylamino group and diethylamine group. [R'' 3449 represents an alkyl group such as a methyl group or an ethyl group, an iR-substituted or unsubstituted phenyl group, or a substituted or unsubstituted benzyl group. Examples of the substituent include an alkyl group such as a methyl group or an ethyl group, a methoxy (B11 is a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a substituted or an unsubstituted phenyl group, n is O
or an integer of 1, A represents a 9-anthryl group or a t*-substituted or unsubstituted N-alkylcarbazolyl group. Here Bla is a hydrogen atom, an alkyl group, an alkyl substituted amino group (R”,!
- represents an alkyl group such as a methyl group, ethyl group, zorobyl group, butyl group, a directly substituted or unsubstituted aralkyl group such as a benzyl group, or a substituted or unsubstituted aryl group such as a phenyl group. , R axis and B1'' may form a ring), m represents an integer of 0, 1.2 or 3, and when m is 2 or more, RW4 may be the same group or different groups. Substituents on the aralkyl group or aryl group in Bla or R1 include a methyl group,
Alkyl group such as ethyl group, propyl group, butyl group,
Examples include alkoxy groups such as a methoxy group and an ethoxy group, halogen atoms such as a halogen atom, and dialkylamino groups such as a dimethylamino group and a diethylamino group. ] Furthermore, specific examples of these lightning and load-carrying substances are as follows.

0,H.

Compound rot structure 2 〇、H40H C, H, Ct U, H, OH Compound 16 Structural formula 0 formula% (40 Compound 16 Structural formula ( Compound 16 formula ? ■(.

Compound A Structural Formula Compound 16 Structure Compound A Structural Formula Compound/f6 Structural Formula Compound 16 Structural Formula Compound 16 Structural Formula Compound Structural Formula 58 Compound/16 Structural Formula Compound Horizontal Structure Above In addition to the exemplified compounds, examples of polymeric substances include poly-N-vinylcarnocesol, halogenated carnocesol, tP IJ-N-vinylcarnocesol, tilivinylpyrene, bromopyrene-formaldehyde condensation resin, and N-ethylcarnocesol-formaldehyde condensation resin. condensation resins, such as
As for the low-molecular-weight substances, any of the known charge transport substances such as oxazyl Kn forms, oxadiazole derivatives, and nitro derivatives of fluorenone are effective.

FIG. 1 is an enlarged sectional view of an electrophotographic photoreceptor showing an embodiment of the present invention. This photoreceptor is constructed such that a charge generation layer 22 and a charge transport layer 33 are provided on an isoelectric support 11 to form a photosensitive layer 44.

The conductive/property support used in the present invention includes aluminum, nickel, chlorine, etc. 1. Metal plates, metal drums, or gold foil, plastic films with thin layers of aluminum, tin oxide, indium oxide, chromium, palladium, etc., and paper or plastic films coated with or impregnated with conductive substances, etc. used.

The charge generation layer 22 is made of a liquid in which a specific disazo compound represented by the general formula (R) shown above is made into fine particles by means such as a ball mill and dispersed in a suitable solvent, or if necessary, a binder resin is added thereto. Transfer the dissolved dispersion liquid to a conductive support l.
It is formed by coating on the l, and if necessary,
For example, the surface is finished using methods such as surface polishing, and the film thickness is adjusted.

The thickness of this charge generating N522 is 0.01 to 5 μm.

Preferably, the thickness is O,OS~2 μm, and the proportion of the disazo compound in the charge generation layer 22 is 10~100. ll, preferably 30 to 95% by weight. Sensitivity is poor when the thickness of the charge generating Aizz film is less than o, o 1 pm <, 5FF
At F+ or higher, potential retention is poor. Furthermore, if the proportion of the disazo pigment in the charge generation layer is less than 10% by weight, the sensitivity is low.

The charge transport layer 33 is formed by coating the charge generating layer 11 with a solution in which the various charge transport substances described above and a binder resin are dissolved in a suitable solvent such as tetrahydrofuran. Here, the proportion of the charge transport substance contained in the charge transport layer 33 is 10 to 80% by weight, preferably 2% by weight.
5 to 75% by weight, and the film thickness is 2 to 100/l? F
! , preferably 5 to 40 μm. If the proportion of the charge transport substance contained in the charge transport layer 33 is less than 10 g
If the weight is more than 80% by weight, the film becomes brittle or crystals are precipitated to make the charge transport layer 33 cloudy, which is not preferable. However, when the thickness of the charge transport layer 33 is less than 2 μttr, the retention of %1 is poor at <100/l.

In this case, the residual potential becomes high.

The binder resin for the charge generating ff422 used here contains at least one of polyester resin, butyral resin, ethyl cellulose resin, epoxy resin, acrylic resin, vinylidene chloride resin, polystyrene, polybutadiene, and their monomers. These include copolymers, which are used in early autumn or in a mixed state of two or more types.

In addition, as the binder F1111'f for air transport W2B5, a copolymer containing at least one of polycarbonate resin, polyester resin, polystyrene, polyurethane resin, epoxy resin, acrylic resin, silicone resin, and their seven members is used. They are used in early autumn or in a mixed state of two or more species.

However, various additives can be added to the charge transport layer 33 for the purpose of improving sinterability or durability. Examples of additives used for this purpose include halogenated paraffin, dialkyl phthalate, silicone oil, and the like. to It
It is also possible to provide an intermediate layer between the rear layer, the charge generation If 422 and the charge transport layer 33, or an automatic coat N on the charge transport layer 33.

Further, the disazo compound of the general formula (1) according to the present invention can be used as a dispersed photoreceptor by dispersing it as fine particles in a binder resin (a charge transport substance may be added if necessary). It can also be used.

Effects The structure of the present invention is as described above, and as is clear from the examples described later, the electrophotographic photoreceptor of the present invention is easy to manufacture.
Moreover, it has excellent properties such as stable characteristics even when the photoreceptor is used repeatedly.

EXAMPLES Next, the present invention will be specifically explained using Examples, but the embodiments of the present invention are not limited thereby.

Example 1 76 parts by weight of disazo compound Al-32, 12,603 parts of a tetrahydrofuran solution (solid content concentration 2%) of polyester resin (Pylon 200.QqJ manufactured by Toyobo Co., Ltd.),
and 370071i parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting fraction was applied onto the aluminum surface of an aluminum-deposited polyester base (conductive support) using a doctor blade, and air-dried.
A charge generation layer having a thickness of about 1 pm was formed. On the other hand, after mixing and dissolving 2 parts of charge transport substance 2-29, 2 parts of polycarbonate resin (Panlite 1300, manufactured by Ondai) and 216 parts of Tetrahydrowara, a solution was prepared. This was applied onto the charge generation layer using a doctor blade and dried at 80°C for 2 minutes and then at 100°C for 5 minutes to form one eaves transport layer with a thickness of about 20 layers, resulting in the laminated layer shown in FIG. A molded photoreceptor/f61 was prepared.

Examples 2 to 50 Example 1 except that the disazo compound and charge transport substance shown in Table 1 below were used instead of the disazo compound Al-32 and charge transport substance Jlz-z9 used in Example 1.
Photoreceptors/Vh2-50 were prepared in the same manner as above.

These photoconductors 1 to 50 were charged negatively by corona discharge at -6 KV for 20 seconds using an electrostatic copying paper tester (Model 5P42B manufactured by Rodenki Seisaku 73f for lions). , leave it in a dark place for 20 seconds, measure the surface potential Vpo (V) at that time, and then irradiate it with light using a tungsten lamp so that the surface force becomes 4.5 lux per month. Calculate the time (seconds) in violet that is 1/2 of Vpo, and calculate the exposure amount El/2 (looks).
seconds) was calculated. The results are shown in Table-1.

Table-1 Furthermore, photoreceptor rot of the present invention 1, Al l, /%21
A31 and 1641 were attached to a Ricoh copying machine, Copy P-500, and image reproduction was repeated 10,000 times. As a result, clear images were obtained from all photoreceptors. From this, it can be understood that the photoreceptor of the present invention has extremely excellent durability.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention. 11... Conductive support 22... Charge generation layer 33.
...'dt I transport Ha4...sensitivity light layer I figure

Claims (1)

[Scope of Claims] L An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, in which the photosensitive layer represents the following general formula (1), where ``Mr'' and ``Proverb'' represent hydrogen, a lower alkyl group, Represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group, and R
8 may be the same or different. Also, R2 and R may jointly form a term.
] An electrophotographic photoreceptor characterized by containing a disazo compound represented by the following.