JPS63158558A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body high in sensitivity and superior in characteristics resisting to repeated uses by incorporating a specified styryl compound in a photosensitive layer as an electric charge transfer material. CONSTITUTION:The photosensitive layer formed on an electric conductive substrate contains at least one of the styryl compounds represented by formula I in which each of R1 and R2 is H, halogen, or alkyl; R3 is H, alkyl, or optionally substituted aryl; X is a group represented by formula II or III; each of R4-R9 is H, halogen, or OH; n is an integer of 0-5, and each of R10-R16 is H, halogen, or OH, thus permitting the obtained photosensitive body to be high in sensitivity even in the case of positive and negative charging, and superior in repeated use characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more specifically, the present invention relates to an electrophotographic photoreceptor, and more specifically, in a photosensitive layer formed on a conductive substrate, a compound having the general formula (1) expressed by fFI is incorporated.
The present invention relates to an electrophotographic photoreceptor containing a styryl compound represented by:

[Conventional technology]

Conventionally, photosensitive materials for electrophotographic photoreceptors (hereinafter also referred to as photoreceptors) have been photoconductive materials such as selenium or selenium alloys, and inorganic photoconductive materials such as zinc oxide or cadmium sulfide. organic photoconductive substances such as po'JN-vinylrubazole or polyvinylanthracene, organic photoconductive substances such as phthalocyanine compounds or bisazo compounds; Dispersed in resin binders are used.

In addition, a photoreceptor must have the function of retaining surface charge in the dark, the function of receiving light and generating charge, and the function of receiving light and transporting charge, but these functions can be achieved in one layer. A so-called single-layer type photoreceptor that has both functions, and a so-called laminated type that has two functionally separated layers: a layer that mainly contributes to charge generation, a layer that contributes to surface charge in the dark, and a layer that contributes to charge transport during light reception. There is a photoreceptor. For example, the Carlson method is applied to image formation by electrophotography using these photoreceptors. Image formation in this method involves charging the photoconductor in a dark place by corona discharge, forming an electrostatic latent image such as text or pictures on the original on the surface of the charged photoconductor, and forming an electrostatic latent image on the surface of the charged photoconductor. After the toner image has been transferred, the photoreceptor is subjected to static electricity removal, removal of residual toner, photostatic static removal, etc. before being reused. be done.

In recent years, electrophotographic photoreceptors using organic materials have been put into practical use due to their advantages such as flexibility, thermal stability, and film-forming properties. For example, poly-N-vinylcarbazole (!:
2,4.7-)linitrofluoren-9-one (described in U.S. Pat. No. 3,484,237)
, a photoreceptor whose main component is an organic pigment (Japanese Patent Application Laid-Open No. 47-375
43 (described in Japanese Patent Application Laid-Open No. 1987-10735), and a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (described in Japanese Patent Application Laid-open No. 10735/1983). Furthermore, many new hydrazone compounds have also been put into practical use.

[Problem that the invention seeks to solve]

However, although organic materials have many advantages that inorganic materials do not have, it is still difficult to find one that satisfies all the characteristics required of electrophotographic photoreceptors, especially light sensitivity and repeatability. There were problems with the characteristics during continuous use.

The present invention has been made in view of the above points, and by using a new organic material that has never been used as a charge transporting substance in the photosensitive layer, copying with high sensitivity and excellent repeatability can be achieved. The purpose of the present invention is to provide electrophotographic photoreceptors for machines and printers.

[Means for solving problems]

In order to achieve the above object, the present invention provides an electrophotographic photoreceptor having a photosensitive layer containing at least one styryl compound represented by the following general formula (1).

(In formula (1), R, and R2 are each a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, and an amino group.

Represents an alkylamino group or an arylamino group, R1
represents a water S atom, an alkyl group, or a substituted or unsubstituted aryl group.

Atom, hydroxy group, alkyl group, alkoxy group.

Allyl group, carboquine group, ester group, aryl group,
ano group, nitro group, amine group, alkyl group.

It represents an amino group or an arylamino group, n represents an integer of 0 to 5, and R1+1 to R+6 each represent a water atom, a halogen atom, a hydroxy group, or an alkyl group.

Represents an alkoxy group, an allyl group, a carboxyl group, a mil group, an ester group, an aryl group, an ano group, a nitro group, an amine group, an alkylamino group, or an arylamino group. ) [Function] There is no known example in which the styryl compound of the general formula (1) used in the present invention is used in a photosensitive layer. The inventors
In order to achieve the above-mentioned purpose, we conducted many experiments on styryl compounds while conducting intensive studies on various organic materials. The inventors have discovered that a photoreceptor with high sensitivity and excellent repeatability can be obtained by using the styryl compound represented by formula (1) as a charge transporting substance in the photosensitive layer.

〔Example〕

The styryl compound of the general formula (1) used in the present invention can be synthesized by a conventional method.

That is, general formula (II) [In formula (If), R1+ Rz and Rs each represent the same substituent as in the above general formula (1), Y is -pi-1000OR+t)2 Z'' (Zo is a halogen ion, Rat is represents a lower alkyl) and a corresponding carbonyl compound. Specific examples of the styryl compound represented by the general formula (I) obtained in this way are illustrated below. Then, it is as follows.

Compound No. l Compound Nα2 to 3
k4 N[15Nα6 Demon7Nα8 k l 9 N(12ONo
, 21 N(L22Nα2
3 Nα24Nα25
No, 26k 27
No. 28 Compound IIα29 Nα3O o31 Nα33 Nα34 Nα35 Compound Nα36 Nα37 Nα38 Nα39 Ma4O Nα41 Nα42 The photoreceptor of the present invention contains the above-mentioned styryl compound in the photosensitive layer. , as shown in FIG. 1, FIG. 2, or FIG. 3.

1 to 3 are conceptual cross-sectional views of different embodiments of the photoreceptor of the present invention, in which 1 is a conductive substrate, 20, 21.2
2 is a photosensitive layer, 3 is a charge-generating material, 4 is a charge-generating layer, 5 is a charge-transporting material, 6 is a charge-transporting layer, and 7 is a coating layer.

FIG. 1 shows a photosensitive layer 20 (usually referred to as a single-layer photoreceptor) in which a charge-generating substance 3 and a styryl compound as a charge-transporting substance 5 are dispersed in a resin binder on a conductive substrate 1. configuration) is provided.

FIG. 2 shows a photosensitive layer 2 formed by laminating a charge generation layer 4 mainly containing a charge generation substance 3 and a charge transport layer 6 containing a styryl compound as a charge transport substance 5 on a conductive substrate 1.
1 (a configuration commonly referred to as a laminated photoreceptor).

FIG. 3 shows an inverse layer configuration to that in FIG.

In this case, a covering layer 7 is generally provided to protect the charge generation layer 4.

The reason for the two types of layer configurations shown in FIGS. 2 and 3 is that the photoreceptor is used in a positive charging system or a negative charging system, and the layer configuration shown in FIG. 2 is usually used in a negative charging system. Even if you try to use the positive charging method with the layer configuration shown in Figure 2,
At present, no charge-transporting substance has been found that meets this requirement. Therefore, as the present inventors have already proposed, the layer structure shown in Figure 3 is considered to be effective as a positive charging type photoreceptor. It can be mentioned.

The photoreceptor shown in FIG. 1 can be produced by dispersing a charge generating substance in a solution containing a charge transporting substance and a resin binder, and applying this dispersion onto a conductive substrate.

The photoreceptor shown in Figure 2 is produced by vacuum-depositing a charge-generating substance on a conductive substrate, or by coating and drying a dispersion obtained by dispersing particles of a charge-generating substance in a solvent or resin binder, and then It can be produced by applying a solution containing a charge transporting substance and a resin binder to a substrate and drying the solution.

The photoreceptor shown in Figure 3 is produced by coating a conductive substrate with a solution containing a charge-transporting substance and a resin binder and drying it, and then vacuum-depositing a charge-generating substance thereon, or by depositing particles of the charge-generating substance in a solvent. Alternatively, it can be produced by coating and drying a dispersion obtained by dispersing in a resin binder, and further forming a coating layer thereon.

The conductive substrate 1 serves as an electrode for the photoreceptor and at the same time serves as a support for the other layers, and may be cylindrical, plate-shaped, or film-shaped, and may be made of aluminum, stainless steel, nickel, etc. It may also be made of metal, glass, resin, or the like, which has been subjected to conductive treatment.

The charge generation layer 4 is formed by applying a material in which particles of the charge generation substance 3 are dispersed in a resin binder as described above, or by a method such as vacuum deposition, and generates charges by receiving light. . In addition, the charge transport layer 6 and the coating layer 7 for the generated charges at the same time have a high charge generation efficiency.
It is important to have good injection properties even in low electric fields with little dependence on electric fields. As the charge generating substance, metal-free phthalonanine, phthalonanine compounds such as titanyl phthalocyanine, various azo, quinone, indigo pigments, selenium or selenium compounds, etc. are used, depending on the light wavelength range of the exposure light source used for image formation. A suitable material can be selected. Since the charge generation layer only needs to have a charge generation function, its thickness is determined by the light absorption coefficient of the charge generation substance and is generally 5 μm or less, preferably 1 μm or less. The charge generation layer is mainly composed of a charge generation substance, and a charge transporting substance can also be added thereto. As the resin binder, polycarbonate, polyester, polyamide, polyurethane, epoxy, silicone resin, polymers and copolymers of methacrylic acid ester, etc. can be used in appropriate combinations.

The charge transport layer 6 is a coating film in which a styryl compound represented by the general formula (1) as an organic charge transport substance is dispersed in a resin binder, and serves as an insulating layer in the dark to retain the charge on the photoreceptor. During light reception, it functions to transport charges injected from the charge generation layer. As the resin binder, polycarbonate, polyester, polyamide, polyurethane, epoxy, /recon resin, methacrylic acid ester polymers and copolymers, etc. can be used.

The coating layer 7 has the function of receiving and retaining the charge of corona discharge in a dark place, and has the ability to transmit the light to which the charge generation layer is sensitive, and transmits the light upon exposure, and the charge generation layer It is necessary for the surface charge to be neutralized and annihilated by the injection of the generated charge. As the coating material, organic insulating film-forming materials such as polyester and polyamide can be used. In addition, these organic materials, glass resin, Si
n.

It is also possible to use a mixture of inorganic materials such as metals, metal oxides, and other materials that reduce electrical resistance. The coating material is not limited to organic insulating film forming materials (inorganic materials such as Sin, metals, metal oxides, etc. can also be formed by methods such as vapor deposition and sputtering.Coating materials As mentioned above, it is desirable that the material be as transparent as possible in the wavelength region where the light absorption of the charge generating material is maximum.

The thickness of the coating layer itself depends on the composition of the coating layer, but
Residual potential increases when used repeatedly and continuously.
It can be set arbitrarily as long as it does not have any effect.

Hereinafter, specific examples of the present invention will be described.

Example 1 50 parts by weight of metal-free phthalonanine (manufactured by Tokyo Kasei Co., Ltd.) ground for 150 hours in a ball mill and 100 parts by weight of the styryl compound represented by the compound Nα1 were mixed with 100 parts by weight of a polyester resin (Vylon, manufactured by Toyobo Co., Ltd.) and a tetrahydrofuran (THF) solvent. The coating solution was prepared by mixing and kneading for 3 hours, and the coating solution was coated onto an aluminum-deposited polyester film (8β-PET) as a conductive substrate using a wire bar method, resulting in a film thickness of 15 μm after drying. A photosensitive layer was formed to produce a photoreceptor.

Example 2 In Example 1, Nα1 of the styryl compound is N.

15, and otherwise formed a photosensitive layer in the same manner as in Example 1 to produce a photoreceptor.

Example 3 First, α-type metal-free phthalocyanine was placed as a starting material, and while two linear motors were placed facing each other, α-type metal-free phthalocyanine and a non-magnetic separation body containing a Teflon piece as a working piece were placed and pulverized. L I MMA C (L
inear induction%! otor! J
ix-ing and crushing (manufactured by Fuji Electric) was performed for 20 minutes to form a fine powder. 1 part by weight of this finely powdered sample and 50 parts by weight of DMF (N,N-dimethylformamide) solvent were subjected to ultrasonic dispersion treatment.

After that, the sample and DMF were separated and filtered, dried and dried.
M7 talonanine treatment was performed.

Next, a styryl compound 10 represented by the compound Xα1
0 heavy ff1 fl to tetrahydrofuran (THF)
A coating liquid prepared by mixing 100 parts by weight of methyl acid polymer (PMMA: Tokyo Kasei) with 700 parts by weight of toluene was applied to an aluminum-deposited polyester film substrate. A charge transport layer was formed by coating on top with a wire bar so that the film thickness after drying was 15 μm. The metal-free phthalocyanine 5 treated as described above is placed on the charge transport layer thus obtained.
0 parts by weight, 50 parts by weight of polyester resin (product name Byron 2002 manufactured by Toyobo), 50 parts by weight of PMMA, and THF solvent were mixed in a mixer for 3 hours to prepare a coating solution, applied with a wire bar, and dried. A charge generation layer was formed to have a subsequent thickness of 1 μm, and a photoreceptor was produced.

Example 4 In Example 3, Nα1 of the styryl compound was changed to Nα15
A photoreceptor was produced in the same manner as in Example 3 except for the following.

Example 5 The composition of the photosensitive layer of Example 1 was changed to 50% metal-free phthalocyanine.
Heavy bond section, styryl compound 100 represented by compound k 1
A photosensitive layer was formed in the same manner as in Example 1, except that parts by weight of the photosensitive layer were changed to 50 parts by weight of polyester resin (trade name: VYLON 200, manufactured by Toyobo Co., Ltd.), and 50 parts by weight of PMMA, to prepare a photoreceptor.

Example 6 In Example 5, Nα1 of the styryl compound was changed to Nα15.
A photoreceptor was produced in the same manner as in Example 5 except for the following.

Example 7 In Example 5, a photosensitive layer was formed in the same manner as in Example 1 using, for example, a chlorodiapolymer, which is a bisazo pigment as disclosed in JP-A-47-37543, instead of metal-free phthalocyanine, and a photoreceptor was formed. Created.

Example 8 In Example 7, Nα1 of the styryl compound was changed to Nα15.
A photoreceptor was produced in the same manner as in Example 7 except for the following.

The electrophotographic properties of the photoreceptor thus obtained were measured using an electrostatic recording paper tester "SP-428J" manufactured by Kawaguchi Electric.

The surface potential V (volts) of the photoreceptor is +6. Ok
This is the initial surface potential when corona discharge of V is performed for 10 seconds to positively charge the surface of the photoreceptor, and then the surface potential is V when the corona discharge is stopped and the surface is held in the dark for 2 seconds.
, (volts), and then irradiated the surface of the photoreceptor with white light with an illuminance of 2 lux to find the time (seconds) until V was halved, which was determined as half-attenuation exposure 1E1z2 (lux seconds). . Further, the surface potential when white light with an illuminance of 2 lux was irradiated for 10 seconds was defined as the residual potential vr (volt). In addition, when a phthalonanine compound is used as a charge generating substance, high sensitivity with long wavelength light can be expected.
At the same time, electrophotographic properties were measured using monochromatic light of nm wavelength. That is, measurements are taken in the same manner up to vd, then 1 μW monochromatic light (780 nm) is irradiated instead of white light to determine the half-attenuation exposure amount (μJ/an), and this light is applied to the photoreceptor surface for 10 seconds. Residual potential V, (
Volts) were measured. The measurement results are shown in Table 1.

Table 1 As seen in Table 1, the photoreceptors of Examples 1 to 8 in which the styryl compound 4mNl11 or N[Li2 was used as the charge transport material had good surface potential, half-attenuation exposure, and residual potential. . Furthermore, the photoreceptors of Examples 1 to 6 in which a phthalocyanine compound was used as a charge generating substance had excellent electrophotographic properties even for long wavelength light of 780 nm.

Example 9 Selenium was deposited to a thickness of 1 on a 500 μm thick aluminum plate.
．． A charge generation layer was formed by vacuum evaporation to a thickness of 5 μm, and then a solution prepared by dissolving 100 parts by weight of a styryl compound represented by the compound Nα2 in 700 parts by weight of tetrahydrofuran (THF) and polymethacrylate poly=-(PMMA) were used.
:Tokyo Kasei) 100 parts by weight dissolved in 700 parts by weight of toluene and a coating liquid made by mixing with a solution using a wire bar to form a charge transport layer so that the film thickness after drying is 20 μm. did. This photoreceptor was corona charged at -6.0 kV for 0.2 seconds, and its characteristics were measured according to Example 8.V, -700V, V.

Good results were obtained at --80V and EI/2 =4.8 lux·sec.

Example 10 In Example 9, Nα2 of the styryl compound was replaced with Nα16
A photoreceptor was produced in the same manner as in Example 9 except that the characteristics were measured.V, -770V.

Good results were obtained with V, --110V, El/2 = 5.3 lux·sec.

Example 11 50 parts by weight of the metal-free phthalo/anine treated in Example 1, 50 parts by weight of polyester resin (trade name Byron 200, manufactured by Toyobo), 50 parts by weight of PMM A and THF solvent were mixed in a mixer for 3 hours. A coating solution was prepared by kneading and coated on an aluminum support to a thickness of about 1 μm to form a charge generation layer. Next, 100 parts by weight of a styryl compound represented by compound Nα3, 100 parts by weight of polycarbonate resin (Panlite L-1250>, and 0.1 part by weight of silicone oil were mixed with 700 parts by weight of THF and 700 parts by weight of toluene to form a charge generation layer. Approximately 15μm above
A charge transport layer was formed.

The photoreceptor thus obtained was corona charged at -5,QkV for 0.2 seconds in the same manner as in Example 9, and its characteristics were measured.V-=-800V, El/2=
A good result of 5.3 lux·sec was obtained.

Example 12 In Example 11, Nα3 of the styryl compound was replaced with Nα1
A photoconductor was prepared in the same manner as in Example 11 except that the photoreceptor was changed to 7, and the characteristics were measured.

A good result of El/□-5.5 lux·sec was obtained.

Example 13 In Example 7, Nα1 of the styryl compound was changed to compounds Nα4 to Nα14, respectively, and a photosensitive layer was formed in the same manner as in Example 7 to prepare a photoreceptor, and rSP-428
Table 2 shows the results of measuring the characteristics using J.

Hand g when a corona discharge of +6.0 ν is performed for 10 seconds in a dark place to positively charge it and irradiated with white light with an illuminance of 2 lux.
Decay exposure bond E1y. (Indicated in lux seconds.

As shown in Table 2, it can be seen that a good half-attenuation exposure amount can be obtained also in the photoreceptors using compounds No. 4 to N.alpha.14.

Table 2 (Part 1) Table 2 (Part 2) Example 14 In Example 13, the styryl compound was
A photoreceptor was produced in the same manner as in Example 13 except that the photoreceptors were changed to Nα18 to Nα42, and the characteristics were measured. The results are shown in Table 3.

Table 3 (Part 1) Table 3 (Part 2) As seen in Table 3, it can be seen that good half-attenuation exposure amounts can also be obtained with the photoreceptors using compounds Nα18 to Nα42.

〔Effect of the invention〕

According to the present invention, since the styryl compound represented by the general formula (I) is used as a charge transporting substance in the photosensitive layer provided on the conductive substrate, the styryl compound represented by the general formula (I) has high sensitivity and repeatability even in positive and negative charging. It is possible to obtain an excellent photoreceptor. In addition, suitable charge-generating substances can be selected depending on the type of exposure light source; for example, by using fucrocyanine compounds and certain bisazo compounds, photoreceptors that can be used in semiconductor laser printers can be created. Obtainable. Furthermore, if necessary, it is possible to provide a coating layer on the surface to improve durability.

[Brief explanation of the drawing]

1.2.3 are conceptual sectional views showing different embodiments of the photoreceptor of the present invention. 1 conductive substrate, 3 charge generation substance, 4 charge generation layer,
5 charge transport substance, 6 charge transport layer, 7 coating layer, 2
0.21.22 Photosensitive layer. 3・' Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one styryl compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In formula (I), R_1 and R_2 are hydrogen atoms,
halogen atom, alkyl group, alkoxy group, amino group,
Represents an alkylamino group or an arylamino group, R_
3 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group. X represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and R_4 to R_9 are hydrogen atoms, halogen atoms, hydroxy groups, alkyl groups, alkoxy groups, allyl groups, and carboxyl, respectively. group, ester group, aryl group, cyano group, nitro group, amino group, alkylamino group or arylamino group, n represents an integer of 0 to 5, R_
1_0 to R_1_6 are each a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group, an alkoxy group, an allyl group, a carboxyl group, an amyl group, an ester group, an aryl group, a cyano group, a nitro group, an amino group, an alkylamino group, or an arylamino group. represents a group. )