JPS59218455A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance stability of a photosensitive body by forming a photosensitive layer contg. a specified disazo pigment as an effective component on a conductive supporting material. CONSTITUTION:A photosensitive layer formed on a conducltive supporting material contains as an effective component a disazo compd. represented by the formula shown here in which R<1>, R<2> are each H, lower alkyl, such as methyl, aralkyl, such as benzyl, aromatic, such as phenyl, or heterocyclic, such as thienyl, and a ring formed from R<1> and R<2> is embodied by a hexylidene ring, etc. A combination of an electrostatic charge generating substance represented by the formula and a charge transfer substance is contained in the photosensitive (photoconductive) layer to form an electrophotographic sensitive body. This charge generating layer has 0.05-2mum thickness and a preferable content of said pigment in this layer is 30-95wt%. Said electrophotographic sensitive body can be easily manufactured and its characteristics is stable even against repreated uses of it.

Description

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

Prior Art As a photoreceptor for electrophotography, there are photoreceptors without plating materials such as those using thren and its alloys, or sensitized male sensitized photoreceptors with zinc oxide dispersed in a binder resin, etc. For organic substances, for example, h2-4 m
? -) Leetlow 9-Fluorenone (TNF),!
A typical example is one using a charge transfer complex with N-vinylcarbazole (PVK).

However, while these photoreceptors have many advantages, they also have various drawbacks.For example, the currently widely used selenium photoreceptors have difficult manufacturing conditions; It was difficult to process into a belt because of its high manufacturing cost and lack of flexibility.
It is also sensitive to heat and mechanical shock, so care must be taken when handling it.

Zinc oxide photoreceptors are low in cost because they can be manufactured by coating a support using inexpensive zinc oxide, but they generally have low sensitivity.

Mechanical defects such as surface smoothness, hardness, tensile strength, abrasion resistance, dust, etc. 1 As a photoreceptor for a plain paper copying machine, which is usually used repeatedly, there are many defects in durability.

Furthermore, a photoreceptor using a charge transfer complex of TNF and PVK has low sensitivity (and is unsuitable as a photoreceptor for high-speed copying machines).

In recent years, extensive research has been carried out to eliminate the drawbacks of these photoreceptors, and in particular, various organic photoreceptors have been proposed. Among others.

A substance that generates charge carriers when irradiated with light (hereinafter referred to as "charge generation material") Jt-containing layer (hereinafter referred to as "charge generation layer")
], a charge generation layer is generated, and a substance that receives and transports fc charge carriers (hereinafter referred to as "charge transport material")
f: Laminated photoreceptors consisting of a main layer (hereinafter referred to as "charge transport layer") generally have higher sensitivity and stable chargeability compared to conventional organic photoreceptors. It has been attracting attention as a photoreceptor for plain paper copiers since -
Some are provided for humor.

As this kind of conventional laminated photoreceptor.

(1) A thin layer of a perylene derivative vacuum-deposited as a charge generation layer and an oxadiazole derivative used as a charge transport layer (see U.S. Pat. No. 3,871,882)
.

(2) A thin layer formed by coating an organic aban solution of chlordian blue as a charge generation layer and a hydrazone compound as a charge transport layer (Japanese Patent Publication No. 55-4238
(see Publication No. 0) are known.

However, although conventional photoreceptors of this type have many advantages, they also have various drawbacks as described below.

The 'fc photoreceptor using the perylene derivative and oxadiazole derivative shown in (1) above is expensive to manufacture because its charge generation layer is formed by vacuum deposition.

The photoreceptor using chlordiane blue and a hydrazone compound shown in (2) above uses an organic amine (which is generally difficult to handle) as a coating solvent for forming a charge generation layer.
For example, it is necessary to use ethylene cyanide, which has disadvantages in producing the S light body.

Purpose The present invention is easy to manufacture and suitable for single use.
The present invention provides an electrophotographic photoreceptor.

Structure The electrophotographic photoreceptor of the present invention is provided on a conductive support with the following general formula (in the formula, R1 and BW lines hydrogen, lower alkyl group).

It represents a substituted or unsubstituted aralkyl group, a substituted X-ray unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group. R' and R1 may be the same or different, and gi and R1 may jointly form an it shadow in the original conductive layer (photosensitive) containing a disazo compound represented by J. It is characterized by having a layer.

Here, examples of lower alkyl groups in general formula CI) include methyl group, ethyl group, propyl group, etc., examples of aralkyl groups include benzyl group, phenethyl group, etc., and aromatic groups include phenyl group, naphthyl group, anthryl group, etc. , pyrenyl group, anthragynonyl group, etc. Examples of the -terocyclic group include chenyl group, furyl group, pyridyl group, carnozolyl group, etc. Examples of the ring formed by Ht and R2 include hexylitine group, henchylidene group, etc. Wolf, henzopentylidene monkey, dibenzopentylidene ring, etc. are praised. Aralkyl, aromatic group, heterocyclic group or R
Substituents on the ring formed by 1, H, and 2 can include lower alkyl groups, low absorption alkoxy groups, halogen Q groups, cyano groups, nitro groups, lower dialkyl groups, and the like.

Incidentally, the present invention is the result of intensive studies to achieve the objective of the inventor.

This invention was developed based on the discovery that the use of a specific disazo pigment (disazo compound) is extremely useful for electrophotographic photoreceptors. Furthermore, the electrophotographic photoreceptor of the present invention is not limited to a single-layer type, but rather is preferably a laminated type in which the photosensitive layer is composed of a charge generation layer and a charge transport layer. This is perfect for such a laminated electrophotographic photoreceptor.

The charge generation layer is formed of a layer containing a disazo pigment represented by the general formula (IJ).The present invention will be explained in more detail below.

First, specific examples of the disazo compound represented by the general formula (I) used in the present invention are as follows.

(The following is a blank space) a B4 These disazo compounds are the diazonium salts described in JP-A No. 54-2129.

The corresponding coupler (2-hydroxy-3-naphthoic acid hydrazide) is mixed with a suitable bath medium such as N,
It can be easily produced by reacting with a base in N-dimethylformamide (DMF) to cause a coupling reaction.

By the way, as mentioned earlier, the photoconductor made by Takamei is
The photosensitive layer contains a charge generating substance represented by the general formula (IJ), but in an actual photoreceptor, the charge generating substance and the charge transporting substance are combined to form the photosensitive layer (light guide 'vL'). layer] is formed.

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

(110 is a small methyl group, an alkyl group such as an ethyl group, 2-
Substituted alkyl group H1l such as chloroether group and 2-hydroxyethyl group is a methyl group, alkyl group such as ethyl group, aralkyl group such as benzyl group, aryl group such as phenyl group, and R12 is a hydrogen atom, a halokene such as chlorine, bromine, etc. Atom, methyl group, ethyl group.

Alkyl groups such as propyl and butyl groups.

Methoxy group, ethoxy group, propoxy group.

It represents an alkoxy group such as 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 111 represents an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group, or an aryl group such as a phenyl group. Substituents for naphthyl, anthryl, and styryl groups.

Examples include alkyl groups such as methyl and ethyl groups, alkoxy groups such as methoxy and ethoxy groups, dimethylamino groups, and dimethylamino groups such as diethyl 7() groups. t7c[R'u hydrogen atom, Me'y-IL an alkyl group such as an ethyl group or a propyl group.

Represents an alkoxy group such as a methoxy group, ethoxy group, or propoxy group, a rogene atom (such as chlorine or bromine), a nitro group, or a hydroxyl group.

B16 is a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, or a propyl group, an alkoxy group such as a methoxy group, a propoxy group, a dimethyl group, or a diethyl group.
a silaalkylamino group such as a natonodialkylamino group, a dibenzylabano group, and a diarylamino group such as a diphenylamino group.

Halokene atoms such as chlorine and bromine, nitro groups, or hydroxyl groups all represent alkyl groups such as methyl groups and ethyl groups, aralkyl groups such as benzyl groups, and aryl groups such as phenyl groups. Alternatively, R22 is a hydrogen atom, an alkyl group such as methyl, ethyl, or propyl, an alkoxy group such as methoxy, ethoxy, or propoxy, a dialkylamino group such as dimethylamino or diethyl group, chlorine, or bromine. halogen atoms such as.

The first nitro group represents an aqueous group. ] (Bu is an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted Itaki ring group, R24
Or RAS is a hydrogen atom.

An alkyl group such as a methyl group, ethyl group, propyl group, or butyl group, a chloro-substituted alkyl group, a hydroxy-substituted alkyl group, or a substituted alkyl group represents an unsubstituted aralkyl group, and R
``Ru'' may be bonded with each other to form a heterocycle including the entire structure. Ethoxy Mfx can include any alkoxy group, halogen atom, bromine, etc.Heterocyclic groups of Bus include pyridyl group, furyl group, and chenyl group.

Indolyl group, pyrrolyl group, quinolyl group.

Examples include carbazolyl group. Examples of the substituent on the phenyl group or heterocyclic group of R2m include alkyl groups such as methyl group and ether group, and alkoxy groups such as methoxy group and ethoxy group. R″ or B
Examples of the aralkyl group of 11 include a benzyl group, and examples of substituents on the aralkyl group include a Tsutaguchigen atom such as chlorine and bromine, an alkyl group such as a methyl group and an ethyl group, and a nitro group. Ru and HtM+
A morpholine ring is an example of a heterocycle formed by bonding with each other. ] [HlM is hydrogen atom, halogen atom such as chlorine, bromine, etc.
1RQ is a hydrogen atom, a halokene atom such as chlorine or bromine, an alkyl group such as a methyl group or an ethyl group, a flukoxy group such as a methoxy group or an ethoxy group, a dimethyl aε) group, or an ethyl abano2! dialkylamino groups such as i\, dibutyl-imino groups, and dibenzyl-imino groups.

Dialkylar epsilon such as chloro-substituted dibenzylamino group
represents an alkyl group such as a nitro group, a cyano group, a halogen atom, a methyl group, or an ethyl group. ] [111 is a hydrogen atom, a halogen atom such as dichloride or bromine, an alkyl group such as a methyl group, an ethyl group, or a methyl group, a methoxy group, or an ethoxy group.

Alcoquine group such as butoxy group or cyano group RA2
′=i scale is a hydrogen atom, methyl, ethyl group,
Alkyl groups such as zotyl group.

Substituted Al:P group such as 2-chloroethyl group, 2-hydroxyethyl group, or substituted or unsubstituted benzyl group h K" tT- is Hal is hydrogen atom, chlorine, bromine, etc.), rogene atom 1 Methyl group , an alkyl group such as an ethyl group or a butyl group, an alkoxy group such as a methoxy group, an ethoxy group, or a cytoxy group, or a dialkylamino group such as a dimethylabano group or a diethylakino group, in Rsl or a benzyl group of 1.81 Methyl group as a substituent.

Alkyl groups such as ethyl groups, methoxy groups.

Examples include alkoxy groups such as ethoxy groups, nitro groups, etc. ◎] (Ar' represents an N-alkyl carno sezolyl group 11i-, and examples of the alkyl groups include methyl, ethyl, propyl, and butyl groups. (R36, B8?, RA9 are hydrogen atoms, halogen atoms such as chlorine and bromine, alkoxy groups such as methyl and ethyl groups, alkoxy groups such as methoxy and ethoxy groups, nitro groups, or ai) groups. is a hydrogen atom, a norogen 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,
Substituted or unsubstituted dialkylamino groups such as dimethyl-remino group, diethylamino group, dibutylamino group, dipendyl-ino group, chloro-substituted dipendylamino group, methyl-substituted dibenzyl-ino group, methoxy-substituted dibenzylamino group, etc. dialkyl ε group h N-methyl-N
0] (R4(I B H-alkyl carbazolyl group,
It represents a pyridyl group, a chenyl group, an indolyl group, a furyl group, or a substituted or unsubstituted naphthyl group, a styryl group or a trithyl group. naphthyl group, styryl group.

Examples of substituents on the anthryl group include alkyl groups such as methyl and ethyl groups, alkoxy groups such as methoxy and ethoxy groups, and dialkylamino groups such as dimethylamino and dimethylamino groups. ] [B41
, R4! are hydrogen atoms, methyl groups, and ethyl groups.

Alkyl groups such as butyl groups, methoxy groups.

It represents an alkoxy group such as an ethoxy group or a butoxy group, a halogen atom such as chlorine or bromine, or a dialkylamino group such as a dimethylamino group or a diethyl group. ] (R41 and 144 are a hydrogen atom, an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and a halogen atom such as chlorine. R4'' and R4O are a methyl group and an ethyl group.

Alkyl groups such as propyl and ethyl groups.

Substituted or unsubstituted aralkyl group, @substituted or unsubstituted aryl group, 84 represents a water'#4 atom, a directly substituted or unsubstituted phenyl group.R4l1. An example of the aralkyl group of H46 is a benzyl group, and an example of the 7'C and aryl group is a phenyl group. Examples of substituents on the 7'ch aryl group include alkyl groups such as methyl, ethyl and butyl groups, ar-xy groups such as methoxy and ethoxy groups, and Examples include dialkylamino groups such as .

] [B411, R2O is an alkyl group such as a methyl group or an ethyl group, or a substituted or unsubstituted phenyl group.

Represents a substituted or unsubstituted benzyl group.

Substituents include alkyl groups such as methyl and ethyl groups,
Examples include alkoxy groups such as methoxy and ethoxy groups. ] (RIIO# R”ill: Upper Ne, a”, R”
4B2 BAM is a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a substituted or unsubstituted phenyl group b. R2 is 0 or 1, and A is a tolyl group or substituted or Represents an unsubstituted N-alkylcarbazolyl group. here.

pH3 is a hydrogen atom, an alkyl group, an alkoxy-substituted amino group (B54, R+111 is a methyl group).

Represents an alkyl group such as an ethyl group, a propyl group, an ethyl group, a substituted or unsubstituted 7-ralkyl group such as a benzyl group, a substituted or unsubstituted aryl group such as a phenyl group,
B again! 14 and R111+ may form a ring. ], 1m represents an integer of 0.1.2 or 3, and when 1m is 2 or more, R" may be the same group or a different group. A substituent in the aralkyl group or aryol group in R14 or Roll Examples include alkyl groups such as methyl, ethyl, propyl, and methyl groups, alkoxy groups such as methoxy and ethoxy groups, halogen atoms such as chlorine, and dialkyl amino groups such as dimethyl amino and diethyl amino groups. Examples of these charge transport materials are as follows.

(Hereinafter margin J Compound ring rot structural formula) % formula % Compound A structure formula CIH, C
ノC, fl, OR C, R, Oll Compound layer 474 Structure 2〇, H
.

Compound A Formula C1i.

Compound/16 Structure Formula Compound A6 Structure Formula Compound I6
Structural formula compound layer Structural formula compound 1 g structure
Formula compound layer 7 inch structure Formula compound shoulder structure Formula compound layer
Structural Formula Compound Shoulder Structure
Structural formula fhi combination tfglJ/I6 Structural formula compound, 46 structure
Formula compound/I6
In addition to compounds with the formula f8 above, polymeric substances include po'J-
N-vinylcarbazole, halogenated-iR-N-
Condensation resins such as hinylcarnozole, yey vinylpyrene, al or bromopyrene-formaldehyde condensation resin, and low-molecular substances such as oxazole derivatives.

Oki? Any of the known charge transport materials such as diazole i-conductors, nitro derivatives of currenone, etc. are effective.

The upper side of the figure is an enlarged cross-sectional view of two representative sides of an electrophotographic photoreceptor according to Kihatsu 8AVtL, and FIG. A single-layer photosensitive layer 4A is provided, and FIG. 2 shows a charge generating layer 22 on a conductive support 11. 'IIE load conveyance The load conveyance system 82 is configured to form a multilayer photosensitive layer 42. Compared to the former, the latter laminated type electrophotographic photoreceptor (shown in Figure 2) has a brighter color.
6fr is advantageous in terms of brightness, and the photosensitive layer is restricted.
:It is also possible to form the compound by dispersing a compound of the general formula (IJ) in a binder resin without using a charge transporting substance.

The Sakai Kamishiki holder 11 used in the present invention is a metal plate, metal drum, or metal foil made of aluminum, nickel, chromium, etc., and aluminum, tin oxide, and indium oxide.

Plastic films provided with a thin layer of chromium, noselasium, etc., paper or plastic films coated with or impregnated with conductive substances, etc. are used.

In a laminated type photoreceptor, the charge generation layer 22 is formed into fine particles by means of a ball mill or the like using a specific disazo compound of the general formula shown above (IJ), and dispersed in a suitable solvent. , or if necessary, a dispersion prepared by dissolving a binder resin therein is coated and formed on a fully conductive support.Furthermore, if necessary, the surface is finished by a method such as nof polishing. The film thickness has been adjusted.

The thickness of this charge generation layer 22 is 0.015 μm.

The charge generation layer 22 preferably has a thickness of 0.05 to 2 μm, and the proportion of the disazo compound in the charge generation layer 22 is 10 to 100% by weight, preferably 30 to 95N. The thickness of the charge generation layer 22 is 0.01 μm or less. If the diameter is 5 μm or more, the sensitivity is poor, and potential retention is poor if the diameter is 5 μm or more. Furthermore, if the proportion of the disazo pigment in the charge generation layer 22 is 10, the sensitivity will be affected under a 10-weight plate. υ is formed by applying a solution onto the charge generation layer 22. Here, the ratio of the charge transport material contained in the charge transport layer 32 is 10 to 80% by weight, preferably 25% by weight.
~75% by weight, and the film thickness is 2 to 100 μm, preferably 5 to 40 μm. If the ratio of the charge transport substance contained in the charge transport layer 32 is less than 10% by weight, the sensitivity is poor, and if the ratio is more than 80% by weight, the film becomes brittle (fcJ).S crystals precipitate and the charge transport rf! I32 becomes cloudy, which is not preferable. Furthermore, if the thickness of the charge transport layer 32 is 2 μm or less, the retention of the first potential is poor, and if it is 100 μm or more, the residual potential becomes high.

The binder resin for the charge generation layer 22 used here includes polyester resin, butyral resin, ethyl cellulose resin, epoxy resin, acrylic resin, and vinylidene chloride resin.

Examples include polystyrene, polybutadiene, and copolymers thereof, which may be used alone or in a mixed state of 28 or more.

Further, as the binder resin for the charge transport layer 32, polycarbonate resin, polyester resin, polystyrene,
Examples include polyurethane resins, epoxy resins, acrylic resins, silicone resins, and copolymers thereof, and these may be used alone or in a mixed state of two or more.

Also,! Various additives can be added to the load conveyance layer 32 for the purpose of improving flexibility or durability.Additives used for this purpose include: paraffin, dialkylphthalate, Examples include silicone oil.

Furthermore, in the photoreceptor of the present invention, if necessary, a barrier layer is provided between the conductive support 11 and the charge generation layer 22, an intermediate layer is provided between the charge generation layer 22 and the charge transport layer 32, and a barrier layer is provided between the charge generation layer 22 and the charge transport layer 32. It is also possible to provide an Otsuki coat layer.

Next, the present invention will be explained in detail with reference to Examples, but the embodiments and limitations of the present invention are limited thereby.

It's not something that will be done.

Example 1 76 parts by weight of disazo compound m1-12'i, polyester resin (2001) Tetrahydrofuran solution (solid content concentration 2 parts) from Iron 2001 Toyobo Co., Ltd. 12603
ii) and 37 oz parts of tetrahydrofuran were pulverized and mixed in an I-luminometer, and the resulting dispersion was applied onto a polyester-based (conductive support) surface coated with aluminum using a doctor blade. It was coated and air-dried to form a charge-generating 1 g# with a thickness of about 1 μm. On the other hand, 2 parts of polycarbonate resin I (Panlite 1300, Teijin Co., Ltd.) and 16 N parts of tetrahydrofuran were mixed in a wet layer to form a solution. This was coated on the entire charge generating layer with a doctor blade and heated at 80°C for 2 minutes and then 1
This was dried at 00° C. for 5 minutes to completely form a charge transport layer having a thickness of about 20 μm, thereby producing an fc laminated type photoreceptor layer as shown in FIG.

Examples 2 to 1O Same as Example 1 except that the disazo compound and charge transport substance shown in Table 1 below were used in place 9 of the disazo compound Al-32 and charge transport substance 2-29 used in Example 1. Photoconductors 42 to 10 were prepared in the same manner, and these photoconductors 1 to 10 were tested using an electrostatic copying paper tester (manufactured by Kawaguchi Machinery Co., Ltd., Model 5P428) at -6 KV. After performing corona emission 11L for 20 seconds to make it negatively charged, it was left in a dark place for 20 seconds, and the surface potential Vpo (V) at that time was measured. 5 lux, and calculate the time (seconds) until the surface potential becomes X of Vpo, h Exposure amount E% (Look 71
seconds) was calculated. The results are shown in Table-1.

(Margins below) Table 1 In addition, the photoreceptor 1 of the present invention was reproduced by Ricoh Co., Ltd. '4.
Attached to the machine Ricobee P-500 to output images Th1O,0
Repeated 00 times. As a result, a clear image was obtained even after 10,000 repetitions. From this, it can be understood that the photoreceptor of the present invention is also excellent in durability.

Hongenmei's electrophotographic photoreceptor is more effective than others, and has excellent properties such as being easy to manufacture and having stable characteristics even when the photoreceptor is used repeatedly.

[Brief explanation of drawings]

1 and 21 are enlarged UT views showing two typical sides of the electrophotographic photoreceptor of the present invention. ]]...Electroconductive support 2]...Charge generating substance 22
...Charge generation layer 3]...Ivy-carrying substance 32.
...'Charge transport layer 41.42...Photosensitive layer helmet 1
Figure 2

Claims (1)

[Claims] 1. The following general formula (IJ (in the formula &R1
and R are hydrogen or lower alkyl groups. Represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group - where R' and R3 may be the same or different; Itt7tbR' and Ha may jointly form fflt-. ] An electrophotographic photoreceptor comprising a photosensitive layer containing a disazo pigment represented by the following as an active ingredient.