JPS60131537A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the spectral sensitivity in the wide range of the visible region to the near infrared region and to also improve the wear resistance and mechanical strength by using specified squarelium pigments as a photoconductive material contained in the photosensitive layer. CONSTITUTION:A squarelium pigment represented by formula I (where R is hydroxyethyl, 2-6C chain alkyl, aryl or benzyl) and a squarelium pigment represented by formula II are incorporated into a photosensitive layer as a photoconductive material to obtain the desired electrophotographic sensitive body. The pigment represented by the formula I is produced by reacting 3,4-dihydroxy-3-cyclobutene-1,2-dione represented by formula III with an aniline deriv. represented by formula IV. The pigment represented by the formula II is produced by reacting 3,4-dihydroxy-3-cyclobutene-1,2-dione represented by the formula III with 4-phenylmorpholine represented by formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor using a Reiko process. More specifically, the present invention relates to an electrophotographic photoreceptor containing a squareium pigment in a photoconductive layer.

Conventionally, inorganic photosensitive materials such as amorphous selenium, selenium alloys, cadmium sulfide, and zinc oxide, and organic photosensitive materials typified by polyvinyl carbazole and polyvinyl carbazole derivatives are widely known as electrophotographic photoreceptors.

It is well known that amorphous selenium or selenium alloys have extremely excellent properties as electrophotographic photoreceptors, and are used in practical applications. However, its production requires complicated steps such as vapor deposition and l), and it also has the drawback that the unproduced film is not flexible. When zinc oxide is used, it is used as a dispersed photosensitive material in which zinc oxide is mixed into a resin, but such photosensitive materials have a drawback in mechanical strength and cannot withstand repeated use as is. .

Light sensitivity/#material, l-1. Tehiro (@1 drag, tau subo 1J vinylcal, pasol is transparent, film forming, possible □
1. Although it has advantages such as flexibility, polyvinylcarbazole itself cannot be put to practical use as it is because it does not have sensitivity in the visible light range. Therefore, various sensitization methods have been devised. There is. However, when polyvinylcarbazole is spectrally sensitized using a dye sensitizer, the spectral sensitivity range is extended to the visible light range, but it still cannot achieve sufficient sensitivity as a photoreceptor for electrophotography, and photofatigue is a problem. It has the disadvantage of being In addition, when chemically sensitized using an electron-accepting compound, a photoreceptor with sufficient sensitivity as a photoreceptor for Seiko photography can be obtained, and some of them have been put into practical use. However, there are still problems in terms of strength, lifespan, etc.

Despite active research and numerous reports on organic dispersion photosensitive materials, a photoreceptor with excellent electrical properties and sufficient sensitivity for use as an electrophotographic photoreceptor has not yet been obtained. .

Currently, there are reports that phthalocyanine exhibits excellent electrophotographic properties as a dispersed light-sensitive material, but it has the disadvantage that its spectral sensitivity is biased toward the long wavelength region, and therefore its red color reproducibility is poor.

An object of the present invention is to provide an extremely highly sensitive light guide material that can be used in any of the current d-photography processes and has spectral sensitivity ranging from the visible region to the near-infrared region. .

Another object of the present invention is to have flexibility that inorganic photosensitive materials do not have, to improve low abrasion resistance and insufficient mechanical strength, which are defects of polyvinylcarbazole-trihetrofluorenone organic photosensitive materials, and to improve visible It is an object of the present invention to provide an electrophotographic photoreceptor which has extremely high sensitivity, has substantially flat spectral sensitivity over a wide range from the near-infrared region to the near-infrared region, and has excellent mechanical strength such as abrasion resistance. .

The present inventors have developed conventional inorganic photosensitive materials, organic photosensitive materials,
We are working diligently to improve the various drawbacks of organic photosensitive materials and to obtain advanced materials that have both excellent electrophotographic properties and flexibility, and also have high sensitivity over a wide range from the visible region to the near-infrared region. Research: Results: □Specific squareium pigments have extremely excellent properties! Headline misfired! completed.

The squareium pigment used in the present invention has the general formula (
1) and represented by formula (I). [In the formula, R is a hydro±diethyl group, a chain alkyl group having 2 to 6 carbon atoms. !
The electrophotographic photoreceptor of the present invention is characterized by having a photosensitive layer containing a squareium pigment represented by (1) and (■).

The squareium pigment of general formula (1') is 3,4-dihydroxy-3-cyclobutene-1 represented by formula (IlI).
, 2-dione and an aniline conductor represented by the general formula (IV) (wherein R represents the same meaning as above). (3,4-dihydroxy-3 indicated by 1
- It is obtained by reacting cyclophenyl-1,2-dione with 4-phenylmorpholine represented by formula (V).

The squareium pigment represented by the general formula (1) has a multilayer structure and can be used in electrophotographic photoreceptors! Wear.

That is, in an electrophotographic photoreceptor including a photosensitive layer with a two-layer structure consisting of a charge generation layer and a charge transport layer, a charge generation layer containing a squareium pigment and a known charge transport layer such as polyvinyldibenzothiophene, polyvinylpyrene, By creating a layer consisting of a photo-Sk polymer such as polyvinylanthracene, polyvinylcarbazole, or triallylpyrazoline, triphenylmethane, oxadiazole, tetraphenylbenzidine, trinitrofluorenone, etc. contained in a tubular binder resin. It is possible to improve the chargeability of the photoreceptor, reduce the residual potential, and improve the mechanical strength of the photoreceptor.

The construction of the four-layer photographic photoreceptor of the present invention having a two-layer structure will be explained. As shown in FIGS. 1 and 2, a charge-generating no. A photosensitive layer 4 made of a laminate with a charge transport layer 3 containing a synthetic transport substance is provided.

'The charge generation layer may be formed by using the squareium pigment alone, but it can also be formed by using it in combination with a binder resin.

The ratio of pigment to binder resin is 10% by weight to 90%
Heavy weight, preferably 10 to 50 weight! ll:%.

Methods for forming a charge generation layer using a squareium pigment alone without using a binder resin include solvent coating and empty vapor deposition.

The thickness of the charge generation layer is 0.1 to 3 μm, preferably 0.2 to 1 μm.
μ.

When dispersing the pigment in the binder, the pigment is ground and used, and the grinding method is 5PEX MILL, ball mill,
A known method such as RED DEVIL (trade name) can be used.

As a binder for the charge generation layer, even if it itself has photoconductivity, light 41! It doesn't have to be sexual. Examples of photoconductive binders include photoconductive polymers such as polyvinylcarbazole, polyvinyl cuff L, /(sol derivatives, polyvinylnaphthalene, polyvinylanthracene, poly and nylpyrene), or other organic matrix materials having charge transport ability. .

Furthermore, a known insulating copper resin that does not have photoconductivity can also be used as a binder. Known insulation 1411m
Examples include polystyrene, polyester, polyvinyltoluene, polyvinylanisole, polychlorostyrene,
Polyvinyl butyral, polyvinyl acetate, polyvinyl butyl methacrylate, copolystyrene-butadiene/, polysulfone, copolystyrene-methyl methacrylate, polycarbonate, etc. can be used.

At this time, in order to further improve the mechanical strength of each photoreceptor, a plasticizer can be used in the same manner as in general polymeric materials. Examples of plasticizers include chlorinated paraffin,
Chlorinated biphenyls, phosphate plasticizers, phthalate plasticizers, etc. can be used, and they are added in an amount of 0 to 10% by weight to the binder to improve the mechanical strength of the photoconductor without reducing its sensitivity or drowsiness properties. It is possible to change τ to −.

A binder in which a squareium pigment is dispersed is spread onto a conductive support. Application methods include dipping, spraying,
There are methods such as a bar coater method and an applique method, and a suitable photosensitive layer can be formed by any of these methods.

In addition, as a conductive support, metal or conductive treated paper,
Polymer film, Nesa glass, etc. can be used.

The electrophotographic photoreceptor of the present invention can be widely used not only in ordinary copying machines but also in semiconductor laser printers, intelligent copiers, and the like.

Next, the electrophotographic photoreceptor of the present invention will be explained with reference to Examples.

Example 1 Squarium pigment (1) in formula (1) in which R represents C or H40H is ground together with methylene chloride and a steel ball for 12 hours. Polyester resin after crushing (product name: Byron 200)
) was added and mixed in an amount of 30% by weight. The mixture has a film thickness of #0.5 after drying on a aluminum plate. The amount of charge generated was formed by applying it with an applicator so that it became μ. On top of this, 1-phenyl-3-Cp-diethylaminosteryl]-5-(p-diethylaminophenyl]-pyrazoline was added to polycarbonate resin (trade name Panlite) for 5 minutes.
A charge transport layer containing 0% by weight and mixed was applied with an applicator to a thickness of about 15 μm.

Next, the surface of the photosensitive layer of this photoreceptor was exposed to 1 L of corona at 16 KV for 2 seconds using a Kawaguchi comfort-free copying paper tester to create a negative band, and then left in a dark place for 2 seconds, and the surface at that time was Potential V. Then, the photosensitive layer was irradiated with a tungsten-logen lamp, and its surface potential was found to be V. Set the time (seconds) it takes to reach 1/2 of the exposure time [11/2 is meta]. As a result, v, = 710
V.

El/2 = 5.0 lux Φ seconds.

and formula (phantom squareium pigment [(2) and (3) respectively)
, (4)% (5) and (6). ] A photoreceptor was prepared in the same manner as in Example 1, except that the photoreceptor was used, and its electrical properties were measured. The results are shown in Table 1.

Examples 7 to 12 In the photoreceptors of the present examples, the order of the charge generation layer and the charge transport layer was reversed. That is, the squareium pigments (1), (2), (3), (4) used in Examples 1 to 6,
Table 2 shows the results of measuring the electrical properties of a photoreceptor prepared under the same conditions except using <5) and (6) and reversing the order of the charge generation layer and charge transport layer.

Table 2

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views of an example of the structure of a photoreceptor for single-child photography according to the present invention. Symbols in the figure: 1... 4-electrode support: 2... Charge generation layer; 3...
Charge transport layer; 4... Photosensitive layer. (3 others) fIA1 diagram 211

Claims (1)

[Scope of Claims] A squareium pigment represented by the general formula (wherein R represents a hydroxyethyl group, a chain alkyl group having 2 to 6 carbon atoms, an aryl group, or a benzyl group) and a square represented by the formula An electrophotographic photoreceptor characterized by having a photosensitive layer containing a lium pigment.