JPH01237554A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body having high sensitivity an excellent repetitive characteristics by using specific org. materials as a charge transfer material in a photosensitive layer. CONSTITUTION:This photosensitive body has the photosensitive layer contg. at least one kind among the compds. expressed by formula I or formula II. In formulas I, II, R1-R13 denote a hydrogen atom, halogen atom, alkoxy group or any of an alkyl group, aryl group, alkyl group, alkenyl group, and thenyl group which respectively may have a substituent; (n) denotes any of 1-3 integer. The photosensitive body having the high sensitivity even at a positive electrostatic charge and negative electrostatic charge and the excellent repetitive characteristics is thereby obtd.

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, a photoreceptor having the general formula (1) or The present invention relates to an electrophotographic photoreceptor containing the compound shown below.

[Conventional technology]

Conventionally, photosensitive materials for electrophotographic photoreceptors (hereinafter also referred to as photoreceptors) include inorganic photoconductive substances such as selenium or selenium alloys, or inorganic photoconductive substances such as zinc oxide or cadmium sulfide in a resin binder. dispersions, organic photoconductive materials such as poly-N-vinylcarbazole or polyvinylanthracene, phthalocyanine compounds or bisazo compounds, or dispersions of these organic photoconductive materials in resin binders. Dispersed ones 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, all of which can be achieved in one layer. A so-called single-layer photoreceptor with the following functions is laminated with functionally separated layers: a layer that mainly contributes to charge generation, and a layer that contributes to surface charge retention in the dark and charge transport during light reception. There is a so-called laminated 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 electrostatic latent images such as letters and pictures on the document by exposing the surface of the charged photoconductor, and This is done by developing a latent image with toner, transferring the developed toner to a support such as paper, and fixing it. After the toner image has been transferred, the photoreceptor is subjected to static neutralization, removal of residual toner,
After photostatic discharge, etc., it is reused.

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 and 2.
4.7-) A photoreceptor consisting of linitrofluoren-9-one (described in U.S. Pat. No. 3,484,237), a photoreceptor containing an organic pigment as a main component (JP-A-47-37543)
(described in Japanese Unexamined Patent Publication No. 10735/1983), 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 to be solved by the invention]

As mentioned above, organic materials have many advantages that inorganic materials do not have, but at present, no material has yet been obtained that fully satisfies all the characteristics required of electrophotographic photoreceptors. In particular, there were problems with photosensitivity and characteristics during repeated and 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 transport material in the photosensitive layer, a copying machine with high sensitivity and excellent repeatability can be achieved. The purpose is to provide electrophotographic photoreceptors for use in electronic and printer applications.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formulas (1) to (2).

[In formula (1) and formula (n), R1 to R13 are a hydrogen atom, a halogen atom, an alkoxy group, or an alkyl group which may have each of the following substituents, A IJ-J14
．． represents an aralkyl group, an alkenyl group, or a thenyl group, and n is an integer of 1 or 2.3 [In formulas (nT) and (rV), R3 to Rt3 are a hydrogen atom, a halogen atom, an alkoxy group, or the following: each represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group which may have a substituent, and n represents an integer of 1 or 2.3. ] R2R, R4R5 [In formulas (V) and (Vl), R1 to R8 are hydrogen atoms.

A halogen atom, an alkoxy group, or an amino group or alkyl group that may have each of the following substituents.

Represents either an aryl group or an aralkyl group, and n is 2,
Represents any of the integers 3.4. [In formula (■) and formula (■), R+ to R6 are hydrogen atoms, halogen atoms,
An alkoxy group, a nitro group, or an amino group which may have each of the following substituents.

It represents any one of an alkyl group, an aryl group, and an aralkyl group, and n represents any integer of 2.3.4. ] [Function] There are no known examples in which the compounds represented by the above general formulas (1) to (2) are used in photosensitive layers. In order to achieve the above objective, the present inventors have carried out numerous experiments on various organic materials and have found that although their technical clarification has not yet been fully elucidated, this We have discovered that the use of specific compounds represented by the above general formulas (formerly or ■) as charge transport materials is extremely effective in improving electrophotographic properties, and we have developed a photosensitive material with high sensitivity and excellent repeatability. He finally gained a body.

〔Example〕

Specific examples of the compound represented by the general formula (1) used in the present invention are as follows.

/ / Further, specific examples of the compound represented by the general formula (11) are as follows.

Cold 11-1;j Specific examples of the compound represented by the general formula (III) are as follows.

(2H5- (2H.

sound [2H5 [2H5 C2H.

(2H.

2H5 Specific examples of the compound represented by the general formula (IV) are as follows.

H3 (2H5 Mu C2H.

c2+-+5 2H5 (2Hs Specific examples of the compound represented by the general formula (V) are as follows.

Compound Ceramic V-1 Sitting V-2 Lagoon V-3 N? V-4 V-5 Cold V-6 Compound N9V-7 Sitting V-9 V-10 Specific examples of the compound represented by the general formula (Vl) are as follows.

Compound pottery vt-i Yang Vl-2 Yang Vl-3 Ceramic Vl-4 Kyo Vl-5 Sitting Vl-6 Compound pottery Vl-7 Island v! -8 Positive Vl-9 Specific examples of the compound represented by the general formula (■) are as follows.

Positive ■-1 Sitting ■-2 Sitting ■-3 Sitting ■-4 Clothes ■-5 Kei ■-7 Spider vII-9 Kei ■-10 Yang ■-14 Ji ■-15 Represented by the above general formula (■) Specific examples of the compound are as follows.

Ceramics-1 Sitting-2 Yang-3 Sitting-4 Yang-6 Sitting-7 Yang-8 Yang-11 South-12 South-14 Yang-15 Mu-16 Invention The photoreceptor has the general formula (I) or ■ as described above.
) are contained in the photosensitive layer, but depending on how these compounds are applied,
or as shown in FIG.

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

FIG. 1 shows a photosensitive layer 20 (commonly referred to as a single-layer photoreceptor) in which the aforementioned compounds, which are a charge generating substance 3 and a charge transporting substance 5, are dispersed in a resin binder (binder) on a conductive substrate 1. ) is provided.

FIG. 2 shows a photosensitive layer 21 (usually It is equipped with a structure called a laminated photoreceptor. A photoreceptor having this configuration is normally used in a negative charging system.

FIG. 3 shows a layer structure opposite to that in FIG. 2, and is normally used in a positive charging system. In this case, it is common to further provide a coating layer 7 to protect the charge generation layer 4.

The reason why the laminated photoreceptor has two types of layer configurations is that even if a photoreceptor with the layer configuration shown in Figure 2 is used in a positive charging system, no charge transport material compatible with this has yet been found. This is because they are not. At present, when applying a positive charging method to a laminated type photoreceptor, it is necessary to use a photoreceptor having the layer structure shown in FIG.

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 spreading this dispersion on 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 the surface of the 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 charge generating substance particles in a solvent or a solvent. It can be produced by applying a dispersion obtained by dispersing it in a resin binder, drying it, and further forming the coating layer 7.

The conductive substrate l 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. Examples of the charge generating substance include metal-free phthalocyanine, phthalocyanine compounds such as titanyl phthalocyanine, various azo, quinone, and indigo pigments, or cyanine and squarylium.

Dyes such as azulenium and biryllium compounds, selenium or selenium compounds, and the like are used, and suitable substances can be selected depending on the light wavelength range of the exposure light source used for image formation. 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 transport substance or the like may be added thereto. As a resin binder, polycarbonate, polyester,
Polyamide, polyurethane.

Epoxy, silicone resin, polymers and copolymers of methacrylic acid esters, etc. can be used in appropriate combinations.

The charge transport layer 6 is a coating film in which a compound represented by the above general formula (I) or (III) is dispersed as an organic charge transport substance in a resin binder, and serves as an insulating layer to retain the charge on the photoreceptor in a dark place. However, when receiving light, it functions to transport charges injected from the charge generation layer. As a resin binder, polycarbonate, polyester, polyamide,
Polyurethane, epoxy, silicone 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 to neutralize and eliminate the surface charges by injecting the generated charges. As the coating material, organic insulating film-forming materials such as polyester and polyamide can be used. In addition, these organic materials and glass resin, S
in.

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, but also inorganic materials such as 5ift, metals,
It is also possible to form a metal oxide or the like by a method such as vapor deposition or sputtering. As mentioned above, it is desirable that the coating material be as transparent as possible in the wavelength region where the charge generating substance absorbs maximum light.

The thickness of the coating layer itself depends on the composition of the coating layer, but
It can be set arbitrarily within a range that does not cause adverse effects such as an increase in residual potential when used repeatedly and continuously.

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

Example 1 50 parts by weight of metal-free phthalocyanine (manufactured by Tokyo Kasei) milled in a ball mill for 150 hours and the above compound Na! A coating solution is prepared by kneading 100 parts by weight of the compound represented by -1 with 100 parts by weight of a polyester resin (trade name: Vylon 200, manufactured by Toyobo Co., Ltd.) and a tetrahydrofuran (THF) solvent for 3 hours in a mixer. A photosensitive layer was formed on an aluminum vapor-deposited polyester film (81-PET) using a wire bar method so that the film thickness after drying was 15 μm, and a photoreceptor having the configuration shown in Figure 1 was formed. Created.

Example 2.3. ．． 4 Examples 2, 3. were prepared in the same manner as in Example 1, except that the compound N[LI-1 in Example 1 was replaced with the compounds NαI[I-1, NαV-1, and N[L■-1], respectively. 4
A photoreceptor was fabricated.

Example 5 First, α-type metal-free phthalocyanine is used as a starting material, and a non-magnetic case containing α-type metal-free phthalocyanine and a Teflon piece as a working piece is placed between two linear motors placed opposite each other to crush it. LIMMAC(inea
r Induction Motor Mix-ing
and Crashing: Fuji Electric) processing 20
It was made into a fine powder. 1 part by weight of this finely powdered sample and 5 parts of DMF (N,N-dimethylformamide) solvent
0 parts by weight was subjected to ultrasonic dispersion treatment. Thereafter, the sample and DMF were separated and filtered, dried, and treated for metal-free phthalocyanine.

Next, a solution prepared by dissolving 100 parts by weight of the compound represented by the compound NαI-2 in 700 parts by weight of tetrahydrofuran (THF) and a polymethyl methacrylate polymer (
PMMA: manufactured by Tokyo Kasei Co., Ltd.) 100 parts by weight to 700 parts by weight of toluene
A coating solution prepared by mixing parts by weight of the solution was coated onto an aluminum-deposited polyester film substrate by a wire bar method to form a charge transport layer so that the film thickness after drying was 15 μm. 50 parts by weight of the above-treated metal-free phthalocyanine and a polyester resin (trade name: Vylon 200 manufactured by Toyobo Co., Ltd.) 5
A heavy cloth solution was prepared by kneading 0 parts by weight and 50 parts by weight of PMMA with a THF solvent in a mixer for 3 hours, and then applied using a wire bar method to form a charge generation layer so that the film thickness after drying was 1 μm. Then, a photoreceptor having the configuration shown in FIG. 3 was manufactured. However, a coating layer not directly related to the present invention was not provided.

Example 6.7.8 Example 6.7 was carried out in the same manner as in Example 5, except that the compound N[1I-2 in Example 5 was replaced with the compounds Nαm-2, V-2, and ■-2, respectively. A photoreceptor of No. 8 was prepared.

Example 9 The composition of the charge generation layer of Example 5 was as follows: 50 parts by weight of metal-free phthalocyanine, 100 parts by weight of the compound represented by the compound NαI-3, and a polyester resin (trade name: Vylon 2).
A photoreceptor was produced in the same manner as in Example 5, except that 50 parts by weight of the photoreceptor (manufactured by Toyobo Co., Ltd.) and 50 parts by weight of PMMA were used.

Example 10.11.12 The compound NαI-3 in Example 9 was replaced with the compound NαI-3. Photoreceptors of Examples to and 11.12 were prepared in the same manner as in Example 9 except that seeds V-3 and N11-3 were used.

Example 13 In Example 5, a photosensitive layer was formed in the same manner as in Example 5, except that chlorodiane blue, which is a bisazo pigment as disclosed in JP-A-47-37543, was used instead of the metal-free phthalocyanine. A photoreceptor was produced.

Example 14.15.16 The above compound Nil I-2 in Example 5 was replaced with the above compounds Nam-2, NIIV-2, Nll-2, respectively.
Example 14. was changed to Example 14.
15.16 photoreceptors were produced.

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

The surface potential V, (volt) of the photoreceptor is +6.0kV in the dark.
This is the initial surface potential when corona discharge is performed for 10 seconds to positively charge the surface of the photoreceptor, and the surface potential V is the surface potential when the photoreceptor surface is then held in the dark for 2 seconds with corona discharge stopped.
(volts), and then the illuminance 2 on the photoreceptor surface.
The time (seconds) required for vd to be halved after irradiation with white light of Lux and Tx was determined and defined as the half-attenuation exposure amount El/□ (lux/second). Further, the surface potential when white light with an illumination intensity of 2 lux was irradiated for 10 seconds was defined as the residual potential V (volt). In addition, when a phthalocyanine compound is used as a charge generating substance, high sensitivity with long wavelength light can be expected.
Electrophotographic properties using nanometer monochromatic light were also measured at the same time. That is, measurements were carried out in the same manner up to (■), then 1μ-monochromatic light (780nm) was irradiated instead of white light to obtain the half-attenuation exposure (μJ/c++f), and this light was exposed for 10 seconds. The residual potential V, (volt) when the body surface was irradiated was measured. The measurement results are shown in Table 1.

Table 1 As seen in Table 1, Examples 1 to 16
The photoreceptor has no difference in half-attenuation exposure or residual potential, and exhibits good characteristics in terms of surface potential. Also, watch 78
Even for long wavelength light of 0 nm, the sensitivity of Examples 1 to 12 in which the phthalocyaninated compound was used as a charge-generating material
The phosphor exhibits excellent electrophotographic properties.
J Example 17
On an aluminum plate with a thickness of 500 μm, selenium was vacuum-deposited to a thickness of 1.5 μm to form a charge generation layer, and then the compound N [Compound 100 represented by L I-4
Part by weight dissolved in 700 parts by weight of tetrahydrofuran (THF) and polymethyl methacrylate polymer (PM
A chamber solution prepared by mixing 100 parts by weight of MA (manufactured by Tokyo Kasei) in 700 parts by weight of toluene was layered using the wire pur method, and charge transport was applied so that the film thickness after drying was 20 μl. A layer was formed to produce a photoreceptor having the structure shown in FIG. Apply a -6, OkV roller to this photoreceptor.

Charging was carried out for 0.2 seconds and the electrophotographic characteristics were measured.V* = -620V, Vr = -40
A good result was obtained: V, E +12 = 4.8 J'tuks·sec. 1 Town Example 18.19.
20 The compound NαI-4 in Example 17 was replaced with the self-described compounds kllll-4, NαV-4, and Nα■-4, and the positions were the same as in Example 17, and Examples 18 and 19.
When 20 photoreceptors were prepared and subjected to electrophotographic characteristics in a bright room in the same manner as in Example 17, the results shown in Table 2 were obtained.
Ta.

Table 2 As seen in Table 2, the characteristics of the sensors of Examples 18, 19, and 20 are comparable to each other, and there is little difference between them and Example 17, showing good results.

Example 21 The metal-free phthalocyanine 50 treated in Example 5 was mixed with 50 parts by weight of a polyester resin (trade name: Vylon 200, manufactured by Toyobo Co., Ltd.) with a THF solvent for 3 hours in a mixer to prepare a dyeing solution. and about 1 on the aluminum support.
A charge generation layer was formed by applying the coating to a thickness of .mu.m. Next, 100 parts by weight of the compound N (compound represented by LI-5), polycarbonate resin (trade name Panlite L-1
250: Kanairi Kasei tm) 100 parts by weight, 0.1 parts by weight of silicone oil, 700 parts by weight of THF, and 700 parts by weight of toluene were mixed, and the mixture was coated on the charge generation layer to a thickness of about 15 μm to conduct charge transport. formed a layer.

The thus obtained photoreceptor was subjected to corona charging of -6.0 kV for 0.2 seconds in the same manner as in Example 17, and its electrophotographic characteristics were measured. As a result, V, = -690 V, E,
, 2=5.3 lux·sec, which was a good result.

Examples 22.23.24 Example 22.23. was carried out in the same manner as in Example 21, except that the compound NαI-5 in Example 21 was replaced with the compounds Nαll-5, kV-5, and Nα■-5, respectively.
When No. 24 photoreceptors were prepared and their electrophotographic properties were measured in the same manner as in Example 21, the results shown in Table 3 were obtained.

Table 3 As seen in Table 3, the characteristics of the photoreceptors of Examples 22, 23, and 24 are comparable to each other, and there is no difference from that of Example 21, indicating good results.

Example 25 The compounds NαI-6 to NαI-14, NαI-1 to NαI-1
αI[-16゜Mag I[[-6~Nαll-14,Nα
IV-1~NαTV-8, kV-6~Nα■-16,P
kLVI-1~NαVl-16, Nα■-6~Nα■-
16, Nα■-1-Nα■-16, photoreceptors were prepared in the same manner as in Example 13, and r S P-4
Electrophotographic properties were measured using 28J. +6 in the dark.
Half-attenuation exposure amount E when 0 kV corona discharge is performed for 10 seconds to positively charge, and white light with an illuminance of 2 lux is irradiated,
, , (lux seconds) are shown in Table 4.

As seen in Table 4, these photoreceptors have comparable half-attenuation exposure amounts and are found to have good characteristics.

〔Effect of the invention〕

According to the present invention, since the compound represented by the formula (1) to (1) of -9 above is used as a charge transport substance on a conductive substrate, it is highly sensitive even in positive charging and negative charging, and has excellent repeatability. An excellent photoreceptor can be obtained. In addition, a suitable charge-generating substance can be selected depending on the type of exposure light source; for example, by using phthalocyanine compounds and certain bisazo compounds, a photoreceptor that can be used in semiconductor laser printers can be obtained. be able to. Furthermore, if necessary, it is possible to provide a coating layer on the surface to improve durability.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are conceptual cross-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 material, 6 charge transport layer, 7 coating layer, 20.
21.22 Photosensitive layer.

Claims (1)

[Scope of Claims] 1) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formula (I) or (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・( I
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(II) [In formula (I) and formula (II), R_1 or R_1_
3 represents a hydrogen atom, a halogen atom, an alkoxy group, or an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or an anyl group, each of which may have a substituent, and n is 1, 2, or 3. Represents any integer. 2) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formula (III) or (IV). ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(III
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(IV) [R_1 to R_1_3 in formulas (III) and (IV)
represents a hydrogen atom, a halogen atom, an alkoxy group, or an alkyl group, an aryl group, an aralkyl group, or an alkenyl group that may each have a substituent, and n is an integer of 1, 2, or 3. represents. 3) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formula (V) or (VI). ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(V) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(VI) [In formula (V) and formula (VI), R_1 to R_8 represent a hydrogen atom, a halogen atom, an alkoxy group, or an amino group, an alkyl group, an aryl group, or an aralkyl group, each of which may have a substituent, and n is 2, 3,
Represents any integer of 4. ] 4) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formula (VII) or (VIII). ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(VII
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(VII
I) [R_1 to R_6 in formula (VII) and formula (VIII)
represents a hydrogen atom, a halogen atom, an alkoxy group, a nitro group, or an amino group, an alkyl group, an aryl group, or an aralkyl group each of which may have a substituent, and n is an integer of 2, 3, or 4. Represents either. ]