JPS60196766A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve electrophotographic characteristics and mechanical characteristics by forming an undercoat layer made of a specified resin between a conductive substrate and an electrostatic charge generating layer and dispersing a charge generating material into a specified binder resin to form said charge generating layer. CONSTITUTION:A photosensitive body is formed by successively laminating an undercoat layer composed essentially of a nylon resin, a charge generating layer (CGL) using a phenoxy resin represented by the formula shown here as a binder resin, and a charge transfer layer (CTL) on a conductive substrate. The formation of the undercoat layer made of an alcohol-soluble nylon resin alleviates the roughness of the surface of the substrate, and permits a uniform CGL to be formed. The nylon resin has good adhesion to the substrate, and prevents injection of opposite charge from the substrate. The use of the phenoxy resin as the binder of CGL permits its OH groups to act as adsorption sites, dispersion of a charge generating material to be improved by an small amt. of said resin, and a uniform and thin CGL to be formed.

Description

Detailed Description of the Invention Technical Field The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor comprising an undercoat layer, a charge generation layer, and a charge transport layer sequentially laminated on a conductive support. Regarding the body.

Prior Art Conventionally, a so-called charge generation layer, which can generate charge carriers by light absorption, is provided on a conductive support, and the charge carriers generated thereon can be moved by the force of an electric field. Many functionally separated laminated electrophotographic photoreceptors provided with a charge transport layer have been proposed. In these laminated electrophotographic photoreceptors, the charge generation layer is generally formed by depositing a charge generation substance such as beam Ss, Se alloy, amorphous Si, or organic pigment by vacuum deposition, glow discharge, etc. No. 48-47838, No. 49-
No. 48334), 2) Se.

Be alloy, ZnO, Ti01. Inorganic pigments such as CdS,
A dispersion of charge-generating substances such as organic pigments and organic pigments is applied by adding a binder if necessary.
18543, No. 55-79449), 3) coating a solution of a pigmented charge-generating substance dissolved in an organic amine (for example, JP-A No. 52-55643).

On the other hand, the charge transport layer is generally formed by dissolving a charge transporting substance such as an electron-donating substance or an electron-accepting substance in a solvent together with a binder if necessary, and applying the solution by a suitable coating method.

In such a laminated type electronic 4 photoreceptor.

In order for the charge generation layer to efficiently absorb light and effectively inject the generated charge carriers into the charge transport layer, the charge generation substance is present uniformly and in a relatively large amount in the layer, and It is preferable that the thickness be as thin as possible. In addition, as a photoreceptor for electrophotography, mechanical strength is naturally required, and for this reason, it is desired that at least the adhesion between each layer be strong. These characteristics are also controlled by the material, surface properties, etc. of the conductive support, and r
It is difficult to improve the characteristics of the charge generation layer.

Purpose The object of the present invention is to provide a subbing layer made of a specific (v) fat between a conductive monolithic support and a charge generation layer, and to form a charge generation layer by applying a charge generation substance to a specific binder. It is an object of the present invention to provide a laminated type electrophotographic photoreceptor having excellent electrophotographic properties and mechanical strength by dispersing the photoreceptor.

Structure The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a conductive support, and the undercoat layer is made of an alcohol-soluble nylon resin. It is characterized in that it contains as a main component a phenoxy resin represented by the structural formula % as a binder in the charge generation layer.

The subbing layer of the present invention is formed by dissolving an alcohol-soluble nylon resin in a suitable solvent such as alcohol, coating the solution on a tetraelectric support according to various known coating methods, and drying.

Examples of alcohol-soluble nylon resins used in the subbing layer of the present invention include nylon 6, nylon 66, and nylon 61.
0, copolymerized nylon 11, nylon 12, etc., so-called copolymerized nylon such as nylon 6/66/bis(4-aminocyclohexyl)methane-6 copolymer, N
- Chemically modified homonylons such as alkoxymethyl-modified nylons can be mentioned. These alcohol-soluble nylon resins are soluble only in limited solvents such as methanol, ethanol, lower aliphatic alcohols such as propatool, tetrahydrofurfuryl alcohol, and dimethylformamide, and therefore it is difficult to provide a charge generation layer thereon. As the solvent for coating the base, it is sufficient to use solvents other than those mentioned above, thus increasing the selectivity of the solvent for coating the core load generation layer. (By using a solvent that dissolves the undercoat layer,
When the charge transport layer is applied, the undercoat layer and the upper layer are mixed, resulting in deterioration of characteristics or, depending on the application method, coating becomes impossible.

All of the above-mentioned solvents can be used as coating solvents for forming the undercoat layer, but among them, methanol, ethanol, propatool, lower aliphatic alcohols thereof, water, trichlorethylene, chloroform, carbon tetrachloride, Compatible products with small amounts of benzyl alcohol, phenol, formic acid, acetic acid, etc. added are preferred. The thickness of the undercoat layer is 0.
．． 05 to 5 μm is appropriate.

Next, the charge generation layer of the present invention will be explained.

The charge generation layer is formed by dispersing a charge generation substance and a phenoxy resin in a suitable solvent that does not dissolve the alcohol-soluble nylon resin, applying this on the undercoat layer according to the well-known coating method, and drying it. be done. Here, as the charged biological substance, for example, C.I. Pigment Pull ~25
[Color Index (CI) 21180), C.I. Pigment Red 41 (CI 21200), C.I. Gid Red 52 (CI 45100), C.I. Basic Red a (CI 45210), as well as azo pigments with carbazole bone cores (JP-A-53 -9
5033), an azo pigment with styrylstilbene bones 4) (described in JP-A-53-138229 → publication), )! Azo pigment with J phenylamine core (q
(described in JP-A No. 53-132547), an azo pigment having a dibenzothiophene core (described in JP-A No. 54-21)
728), an azo pigment having an oxadiazole core (described in Japanese Patent Application Laid-open No. 12742-1983),
Azo pigment with fluorenone bone core (JP-A-54-22
834), an azo pigment having a bisstilbene core (described in % JP-A-54-17733), an azo-pigment having a distyryloxadiazole core (described in JP-A-54-2129) ), an azo pigment having a distyrylcarbazole core (described in JP-A No. 54-17734, a), a trisazo pigment having a carbazole core (described in JP-A-57-195767, JP-A-57-19)
7 talocyanine distillates such as CI Pigment Blue 16 (CI 74100), CI Batburakun 5. (CI 734
10), Sea Eye Bat Die (CI 73030)
organic pigments such as indigo pigments such as Argo Scarlet B (Violet H), perylene pigments such as Indanthrene Scarlet R (Beyer Co., Ltd.), So, S@
NI@moderating materials such as alloy, Cd8, amorphous St, etc. can be used. The ratio of the 1-charge biological material to the phenoxy resin is preferably 100:1 to 1:1.

Preferred solvents include benzene, toluene, xylene, methylene chloride, dichloroethane, monochlorobenzene, dichlorobenzene, L-ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexanone, methyl cellosolve, ethyl cellosolve, etc. When the phenoxy resin and the charge generating substance are dispersed in a solvent, a very fine dispersion can be obtained and extremely uniform charge generation can be formed. This is thought to be due to the presence of alcoholic hydroxyl groups in the phenoxy resin. Note that the thickness of the charge generation layer is 0.01 to 2.0 μm.
is preferred.

The charge transporter of the present invention incorporates a '4611J transport material, a binder and, if necessary, a plasticizer and a leveling agent in a suitable solvent, which is then subjected to charge generation according to various known methods.
- Formed by coating and drying. Here, the charge transport substances include poly-N-vinylcarbazole and its derivatives, poly r-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole. Electrons such as rust conductor, imidazole rust conductor, 9-(p-diethylaminostyryl)anthracene, 1,1-bis(4-dibenzylaminophenyl)propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-stilbene derivatives, etc. Examples include donating substances. As a binder, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyester Vinylidene chloride, polyarylate resin, phenolic resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy'fL
4 JJIt, melan resin, urethane resin, phenol resin, alkyd resin, and other thermoplastic or thermosetting resins. In addition, as a solvent, tetrahydrofuran,
Dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc. are used. The thickness of the charge transport layer is suitably 5 to 100 microns.

As the conductive support, aluminum, nickel, chromium, nichrome, copper, tin oxide, indium oxide, etc. are vapor-deposited on plastic film, aluminum, nickel, stainless steel sheets, and their films.1. , ,
I, 1. It is possible to use pipes that have been made into wood pipes by methods such as extrusion, drawing, etc., and then surface-treated by cutting, superfinishing, polishing, etc.

The laminated type 1 photoreceptor for hand photography based on the effect has excellent electrophotographic properties and mechanical properties. The details of why such characteristics (9) are obtained are unknown, but by providing an undercoat layer made of alcohol-soluble nylon resin between the conductive support and the charge generation layer, the conductive support The unevenness of the surface is alleviated, and when a charge generating layer is provided on top of the charge generating layer, an extremely uniform charge generating layer is obtained without any shadow from the unevenness. The alcohol-soluble nylon resin used in the undercoat layer has excellent adhesion to commonly used adhesive supports; When phenoxy resin is used as a binder, the hydroxyl groups of the phenoxy resin act as adsorption sites, and the presence of a small amount can disperse the charge-generating substance in a favorable state and form a uniform and thin charge-generating layer. This is thought to be due to the collapse of the adhesiveness with alcohol-soluble nylon resin and many other resins.

Example 1 0, 5 fi thick aluminum plate (JIS) o7o,
Bright aluminum) and alcohol-soluble nylon resin (CM-
A coating solution consisting of 8000 nylon 6/66/610/12 copolymer (manufactured by Toshi Co., Ltd.) and 190 g of ethyl alcohol was applied by dip coating, dried and wired to form a 0.2 μm thick undercoat layer.

Next, as a charge generating substance, a disazo pigment having the following structural formula: 2.511, a 5 weight ratio cyclohexanone solution 1101I of phenoxy resin (manufactured by Union Carbide Co., Ltd., P+<tlH), and cyclohexanone 47.5
Take g into a ball millbot and use 10i1 as a mill member.
After 48 hours, the mill base was taken out into a container using a 11-day SUS ball, diluted with cyclohexane so that the solid content concentration was 1 wt %, and stirred to prepare a dispersion for coating the charge generation layer. Next, this dispersion was coated by dip coating on the above-mentioned undercoat layer, and dried to form a charge generation layer having a thickness of 0.2 μm.

A liquid solution for forming a charge transport layer having the following composition was prepared and applied by dip coating onto the raw layer, dried to form a charge transport layer with a thickness of 20/J, and coated on the conductive support layer. A secondary photographic photoreceptor was prepared in a laminated type C having a structure of pulling layer-charge generating layer-1 carrier layer.

C2H.

Polycarbonate resin (K-130 (manufactured by I-Dai Kasei) 2
0p-/Re:+7oy/'(KF50 Shin-Etsu Chemical'#
) o, 004 fi methylene chloride 152 , il Comparative Example IF A stacked l-type core photographic photoreceptor was prepared in exactly the same manner as in Example 1 except that no F pulling layer was provided.

This was used as a comparison sample with the example.

Example 2 Alcohol 5T bath a f iron tree)
I'd (Diamide
I, consisting of 190 g of methyl alcohol @.

The fabric ridges were cast using a doctor blade and transferred to provide a 0.2 μm thick undercoat M.

Next, as a charge generating substance, 2.5 g of a disazo pigment having the following structural formula: Phenoxy resin (Union Carbide Co., Ltd. JAPKHE (manufactured by Aiko Pure Chemical Industries, Ltd.) 5-layer plated tetrahydrofuran solution 110I, tetrahydrofuran 47.5 I! Place in a ball mill pot;
Using 10g SUS balls as mill parts, 48
After ball milling for an hour, further tetrahydrofuran 36I.

Ethyl Celsolve 54II was added and milled for 1 hour. After milling, take out the mill base into a container, and the weight ratio of tetrahydrofuran and ethyl cellosolve is 4=6, solid content? The dispersion was diluted and stirred so that the hollowness was 1 wt. to prepare a dispersion liquid for coating the charge generation layer. Next, this dispersion was applied onto the above-mentioned undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm.

Next, prepare a magnetic cloth liquid for forming a charge transport layer with the following composition, dip and tilt it onto a drying layer, dry it, and form a charge transport layer with a thickness of 20 μm. A laminated photoreceptor for photographic use having one load-generating layer and one load-carrying layer was prepared.

α-Stilbene compound polycarbonate resin (K-1300 manufactured by Ondai Kasei) 2
0 I silicone oil (KF50 manufactured by Shin-Etsu Chemical) 0.
004 Jil Methylene Chloride 1529 Comparative Example 2 A laminated electrophotographic photosensitive material was prepared in exactly the same manner as in Example 2, except that urethane resin (278M, manufactured by Nippon Polyurethane Co., Ltd.) was used instead of phenoxy resin as the binder for the charge generation layer. A sample was prepared and used as a comparison sample with the example.

The electrophotographic properties of the photoreceptor for single-child photography produced as described above were evaluated using an electrostatic copying paper testing device (Model SP 428 manufactured by Roki Seisakusho Co., Ltd.) under the following conditions. (Measured in dynamic mode.) First, the sample was charged by applying corona formation at -6 KV for 20 seconds, and the surface potential of the band layer after 1 second and 20 seconds was determined by Vs (Volt) m.
VR (VOIt) was determined as Id, and the specimen was left in the dark for another 20 seconds, and the surface potential Vo (Volt) at that time was measured.
Next, 4.51ux white tungsten light was irradiated,
H light scattered when Vo is '/1g K zK %*E
/1. (lux m sec ), and Table 1 ml potential V, 30 seconds after irradiation. (Volt) was measured and set as initial characteristics. Next, the electrophotographic photoreceptor sample was transferred to a dedicated fatigue testing machine, and the discharge current of the magnetizer was adjusted so that the current flowing through the photosensitive layer was 9.6 μA when irradiated with 45 lux of light. Light irradiation and discharge were applied continuously for 30 minutes. (Under these conditions, the amount of charge passing through the photosensitive layer is approximately 5.24X
10-'coulombs/d, which corresponds to 2000 to 3000 copies per minute in a normal copying process. ) After fatigue, immediately transfer the photoreceptor sample to the electrostatic copying paper tester described above and test vllVs,
Vo, E'/1g + Vso were measured and used as fatigue characteristics.

The above measurement results are shown in the table below.

From this table, the laminated electrophotographic photoreceptor of the present invention exhibits excellent electrophotographic properties and exhibits little change in properties due to fatigue. On the other hand, when the undercoat layer is removed as in Comparative Example 1, the charging potential decreases, especially the rise potential decreases (11) (severely).

In addition, in the charge generation layer of Comparative Example 2 in which urethane resin was used as a binder, the pigment was not dispersed in a well-dispersed state, and as a result, only a thin layer was obtained that was uneven and lacked luster. It appears that the rise is becoming more rapid.

Procedural amendment 1982 Patent Application No. 53895 2 Name of the invention Photoreceptor for electrophotography 3 Relationship with the person making the amendment Patent applicant 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Stock Ricoh Company - Representative Hama 1) Hiroshi 4, Agent 5, "Detailed Description of the Invention" column 6 of the specification subject to the amendment, inscription of the amendment 1) Page 9, line 12 of the specification, "- "Stilbene" was corrected to "-phenylstilbene".

2) The last line of page 12 has been corrected to "Cyclohexane Jya-r cyclohexanone."

3) 3rd to 2nd lines from the bottom of page 14 “(Manufactured by Wako Tsumugi Pharmaceutical Co., Ltd.)
” to be deleted.

4) 2nd line from the bottom of page 15 “α-stilbene compound”
is corrected to "α-phenylstilbene compound".

that's all

Claims (1)

[Claims] 1. An electrophotographic photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a conductive support,
An electrophotographic photoreceptor characterized in that the undercoat layer contains an alcohol-soluble nylon resin as a main component, and the charge generation layer contains a phenoxy resin represented by the structural formula % as a binder.