JPH01230059A - Photosensitive body - Google Patents

Abstract

PURPOSE:To provide excellent carrier generating power and high sensitivity and small residual potential and to improve the durability against repetitive use by providing a photosensitive layer contg. a specific squarium compd. on a conductive base. CONSTITUTION:The photosensitive layer contg. the squarium compd. expressed by formula I is provided on the conductive base. In formula I, R<3>-R<6> denote a hydrogen atom., alkyl group (preferably a methyl group) or halogen atom. (preferably a fluorine atom., chlorine atom., bromine amin); Ar denotes a phenyl group, naphthyl group, anthranyl group, condensed polycycle or heterocycle which may have a substituent. The substituent of Ar is exemplified by, for example, an aralkyl group, alkoxy group, diaralkylamino group, diarylamino group. The photosensitive body which has the electrostatic charge characteristic, sensitivity characteristic and image forming characteristic, is less fatigued and deteriorated even after repetitive use and has the excellent durability is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photoreceptor, and more particularly to a novel photoreceptor having a photosensitive layer containing a specific squalium compound.

[Prior Art] Conventionally, as electrophotographic photoreceptors, inorganic photoreceptors having a photosensitive layer containing a non-modified Q-electrode compound such as selenium, zinc oxide, cadmium sulfide, silicon, etc. as a main component have been widely used. . However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, manufacturing cost, etc. For example, when selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture, and it also crystallizes due to heat, fingerprints, etc., degrading its performance as a photoreceptor. In addition, cadmium sulfide has problems with moisture resistance and durability, and zinc oxide has problems with durability, etc.

In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, Japanese Patent Publication No. 50-10496@ describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole lintro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability.

In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with higher performance by assigning the functions of carrier generation and transport to other materials. Many studies have been conducted on such so-called functional separation type photoreceptors, as each material can be selected from a wide range and a photoreceptor with arbitrary performance can be produced relatively easily. .

[Problems to be Solved by the Invention] Many compounds have been proposed as carrier-generating substances in the functionally separated type photoreceptor as described above.

An example of using a Myriad-1 compound as a carrier generating substance is, for example, amorphous selenium described in Japanese Patent Publication No. 113-IGI98, which can be used in combination with an organic photoconductive compound. However, the drawback that the carrier generation ability of amorphous selenium crystallizes due to heat and deteriorates the characteristics as a photoreceptor has not been improved.

There are also organic dyes! ; Many electrophotographic photoreceptors using pigments as carrier-generating substances have also been proposed. Typical examples include bisazo compounds (Electrophotography Society 59th Research Symposium, p. 179, 1987), phthalocyanine compounds (JP-A-61-239248), azulenium compounds (Electrophotography Society 55th Research Symposium, p. 60, 1
985), Squarium compound (JP-A-61-37)
846), etc. However, these compounds are not necessarily satisfactory in terms of sensitivity, residual potential, or stability during repeated use.
In addition, the selection range of carrier transport substances is limited, etc.
It does not fully satisfy the wide range of requirements of electrophotographic processes.

Furthermore, in recent years, the A-traser and l-1e light sources have been used as light sources for photoreceptors.
Gas lasers such as -Ne lasers and semiconductor lasers are beginning to be used. These lasers are characterized by their ability to be ONLOFFed in time series, and are particularly promising as a light source for copying machines and computer output printers that have image processing functions, such as intelligent copiers. Among these, semiconductor lasers are attracting attention because they do not require an electrical signal/optical signal converter such as an acoustic engineering element due to their nature, and they can be made smaller and lighter. However, this semiconductor laser has a low output compared to a gas laser, and the emission wavelength is long (approximately 78 Or+m or more), so the spectral sensitivity of conventional photoreceptors is often on the short wavelength side, and the sensitivity characteristics However, there was nothing that was practically satisfactory.

[Object of the Invention J An object of the present invention is to provide a photoreceptor containing a specific squalium compound that has a high carrier generation ability.

An object of the present invention is to provide a durable photoreceptor that has high sensitivity and low residual potential, and whose characteristics do not change even after repeated use.

Still another object of the present invention is to provide a photoreceptor containing a squalium compound that effectively acts as a carrier generating substance even in combination with a wide range of carrier transporting substances.

Still another object of the present invention is to provide a photoreceptor having sufficient practical sensitivity even to long wavelength light sources such as semiconductor lasers.

Still other objects of the present invention will become clear from the description in the specification.1゜[Means for Solving the Problems] The present inventors have conducted extensive research in order to achieve the above objects. As a result of repeated investigations, it was discovered that the squalium compound represented by the following general formula [I] is absorbed by the organic components of the photoreceptor, thereby completing the present invention.

General formula [I] In the formula, R11, R1 and R2 are each a hydrogen atom, a halogen atom (preferably a fluorine atom), an alkyl group (preferably a methyl group), an alkoxy group (preferably a me-1-oxy group), or a hydroxyl group. Represents the staff or NHY. , Y is -C
-R' or -302-Ra (R' and R8 each represent an alkyl group, a phenyl group, water f, or an OF atom, which may have a substituent). R3, R4,
R5 and R6 represent a hydrogen atom, an alkyl group (preferably a methyl group), or a halogen atom (preferably a fluorine atom, a chlorine atom, or a bromine atom). Ar represents a phenyl group, a naphthyl group, an herranyl group, a condensed polycyclic ring, or a heterocyclic group which may have a substituent. Examples of the substituent for Ar include an alkyl group, an alkoxy group, a halogen atom, a cyano monomer, an encyclopedia, -del, su, an acyl group, a dialkylamino group, a sia7ral, a V-ruamino group, a diarylamino group, and the like. be able to.

Specific examples of the squalium compounds useful in the present invention are shown below, but the squalium compounds of the present invention are not limited thereto.

-I B-9 B-13 B-26 B-33 shiH)＞(J2NtI N11bLJzshiMkoB-5
0 B-57 B-58 - ^- The squalium compound of the present invention represented by the general formula [I] ) First, indoline (manufactured by Merck & Co., Ltd.) of the above general formula (S-1) was benzylated to obtain a compound (S-3).

Next, Square Rick 1li (S-4) (manufactured by Tokyo Kagaku Co., Ltd.)
5.0'J (4,38x 1O-2Illol
) and compound (S-3) 24.29 (1,16xlo
``moj!'' was placed in a 300 vfl turning flask, 1-heptatool 2201f was added, and the mixture was heated under reduced pressure (
140n+m1-Hl±1On+ff1l-1(J)
Then, stir and reflux. Remove the water with an ester tube, about 1cc
Heating stops when water collects in the ester tube.

. It took about 30 hours. When the reaction solution cooled to room temperature, the reduced pressure was released and precipitation occurred. Filter the refined product using a Kiryama funnel. Wash 3 times with acetone, 3 times with hot water, and 2 times with Me 0)-1. Dry overnight at 70-80°C. 10.6 g of green crystal target substance (B-1) (yield 49%)
100 noko.

B-1 (R structure is FD-~=IS spectrum, m
This was confirmed by showing an M+ peak at /z = 496 and by the fact that the direct elemental analysis agreed well with the calculated value (see below).

Determined values: C = 82.18%, H = 5.68%.

N-5,62% Calculated values: C = 82.26%, H = 5.65%.

N=5.65% Note that the melting point was 240°C.

The squarium compound of the present invention has excellent photoconductivity, and when producing a photoreceptor using the same, the squarium compound of the present invention is dispersed in a binder on a conductive support. Among the photoconductivity of the squalium compound of the present invention, it is used as a carrier generating substance by utilizing the particularly excellent ability to generate Q and V ria, and is effective in combination with this. Particularly excellent results can be obtained when a so-called freeze-separated type photoreceptor is constructed by using it together with a carrier transporting substance that can act on a carrier transport substance. The functionally separated photoreceptor may be of a dispersed type, but it is more preferably a laminated type photoreceptor in which a carrier generation layer containing a carrier generation substance and a carrier transport layer containing a carrier transport substance are laminated.

When the squalium compound of the present invention is used as a chyrelia-generating substance, examples of the carrier transport substance used in combination with it include electron-accepting substances that easily transport electrons, such as trinitrofluorenone or the-1-ranitrofluorenone. , a polymer having a heterocyclic compound in its side chain, such as poly-N-vinylcarbazole;
Triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline M 39 derivatives, polyaryl alkane derivatives, phenylenediamine if's'J derivatives, hydrazone derivatives, amino-substituted carbon derivatives, triarylamine derivatives bald) stop (tree,
Examples include electron-donating substances that transport holes such as methylben derivatives, phenothiazine derivatives, azine derivatives, butadiene derivatives, and cisofubene derivatives, but the carrier transporting substances used in the present invention are limited to these. isn't it.

Various types of IS are known for the mechanical configuration of the photoreceptor, but
The photoreceptor of the present invention can take any of these forms.

Usually, the configuration is as shown in FIGS. 1 to 6. Figures 1 and 2
In the figure, a photosensitive layer 4 consisting of a laminate of a carrier generation layer 2 containing the above-mentioned squarium compound as a main component and a carrier transport layer 3 containing a carrier transport substance as a main component is provided on conductive supports 1 and 11. establish. As shown in FIGS. 3 and 4, this photosensitive layer 4 may be provided via an intermediate layer 5 provided on a conductive support. In this way, the photosensitive layer 4 is
The photoreceptor that exhibits the most excellent electrophotographic properties when it has the following characteristics is 19. Further, in the present invention, as shown in FIGS. 5 and 6, the photosensitive layer 4 comprising the carrier generating substance 7 and the carrier transporting substance dispersed in the layer 6 is formed directly on the conductive support 1 or It may also be provided via the intermediate layer 5.

The carrier generation layer 2 constituting the two-layered photosensitive layer 4 is applied directly to the conductive support 1 or the chyrelia transport layer 3, or if necessary, an intermediate layer such as a τ adhesive layer or a barrier layer is provided thereon, for example. It can be formed by the following method.

M-1) A method of applying a solution in which a squalium compound is dissolved in a suitable male medium, or a solution in which a binder is added and mixed as necessary.

M-2) A method in which a squalium compound is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc., and a binder is added as necessary to mix and disperse the resulting dispersion and then applied.

Examples of the solvent or dispersion medium used for forming the carrier generation layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, and cycloheporinone. , benzene, 1-luene, xylene, chloroform, 1,2-dichloroethane, 1.1.2-1-dichloroethane, 1,1.1-1-lichloroethane, trichloroethane, tetrachloroethane, dichloroethane', tetrahydrofuran, dichloroethane, Examples include ethanol, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and the like.

If a binder is used in the carrier generation layer or the carrier transport layer, a binder of 1% or 13% can be used, but it is preferable to use a film-forming polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating. It is preferable to use Examples of such a polymeric polymer include, but are not limited to, the following.

P-1) Polycarbonate] - P-2) Polyester P-3) Methacrylic resin P-4) Acrylic (fit resin P-5) Polyvinyl chloride P-6) Polyvinylidene chloride P-7) Polystyrene P-8) Polyvinyl Acetate P-9) Styrene-butadiene copolymer p-10) j3
: Vinylidene chloride-acryloni i-lyl copolymer))-11) Vinyl chloride-vinyl acetate copolymer P-1
2> Vinyl chloride-vinyl acetate-maleic anhydride copolymer P -13) Silicone resin p -14) Silicone-alkyd resin P -15> Phenol formaldehyde resin P16) Styrene-alkyd resin p -17) Poly-N-vinyl Carbazole P-18
) Polyvinyl butyral P-19) Polyvinyl formal P-20 > Vinyl acetate resin P-24) Epoxy resin These binders are rarely used alone or as a mixture of two or more.

The thickness of the carrier generation layer 2 formed in this way is
0.001 μm to 20 μm, more preferably 0.05 μm to 5 μm. Further, when the carrier generation layer or the photosensitive layer is a dispersed type, the grain size of the squalium compound is preferably 5 μm or less, more preferably 1 μm or less.

For the conductive layer, a non-81 conductive compound such as titanium oxide, tin oxide, or copper iodide, or a wired conductive compound such as carbon, an organic semiconductor, or a conductive polymer is dispersed in a binder on a conductive support. It can be formed as is or by coating it as is.

The squalium compound of the present invention can be subjected to various processes to improve its dispersibility from the viewpoint of powder and granule engineering. For example, wet jΔ powder method spray drying,
Freeze drying, dry grinding, etc. can be used.

Further, by changing the crystal form, electrophotographic performance and dispersibility can be improved. For example, the crystal form may change depending on the method of dissolving with an amine and then neutralizing and precipitating with an acid, or depending on pressure, temperature, etc.

The conductive support used in the photoreceptor of the present invention includes a metal plate including an alloy, a metal drum, a conductive polymer,
A thin layer of metal such as aluminum, palladium, gold, etc. containing a conductive compound or alloy such as indium oxide is coated, vapor-deposited or laminated to achieve 6H properties, such as Iζ paper and plastic film.

For the intermediate layer such as the contact layer or the V-layer, in addition to the polymer used as the binder, a wired polymer material such as polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, or aluminum oxide is used.

The photoreceptor of the present invention has the above-mentioned structure, but as is clear from the examples described below, it has poor charging characteristics, sensitivity characteristics, and image forming characteristics, especially when used repeatedly. It has low fatigue deterioration and excellent durability.

[Example 1] Hereinafter, the present invention will be specifically explained using Examples, but the embodiments of the present invention are not limited thereto.

(Actual! N1) In a 300 nf stainless steel pot, 0.75 g of polyvinyl butyral resin (trade name, XYHL), 150 d of tetrahydrofuran, and Squarium Compound B-11,5
Add 150 g of glass peas and disperse with a sand grinder for 48 hours. This dispersion barrier was coated on an aluminum vapor-deposited base so that the film thickness after drying was approximately 0.2μ.
It was coated with a wire bar to form a carrier generation ff (CGL). Next, polycarbonate resin (trade name, Panlight T-) 7. J and j: -14.0 g of ethylene chloride 50112 and the following carrier transport substance are mixed under magnetic stirring. This liquid was applied onto the CGL using an applicator so that the film thickness after drying was 20 μm to form a chitria transport (CTL).

After being placed in an oven and thoroughly dried, the electronic image quality was tested. That is, after charging an electrostatic copying tester made by Kawaguchi Electric by performing a J: Lee 6KV corona discharge for 5 seconds, it was left in a dark place for 5 seconds, and its surface potential V8 was measured. The photosensitive layer was irradiated with a tungsten halogen lamp with an illuminance of 14 lux, and the time required for the surface potential to become half of that of ■ was calculated to determine the half exposure mE1/2.

As a result, VA = 1200V, E l/2 =
It was 2.51 ux-sec.

Next, image characteristics and durability were evaluated using Konica (11'FJI)
Tested with a D printer (semiconductor laser with light source 7'lQnm±1001). In the picture drawing test of 10,000 strokes and above, a good picture W was given IS.

Examples 2 to 10 In Actual Flow Example 1, a photoreceptor was prepared by changing the carrier generating substance <CGM) B-1 and the carrier transporter <J) A quality (CTM) K-1 as shown in Table 1. The electronic copying performance was evaluated in the same manner as in Example 1. Table 1 shows the antagonists.

1st bottom margin -Top 1 Table 1 The CTMs in Table 1 are shown below.

-3 -4 -5 -7 -8 -9 Actual flow example 11 The photoreceptor was prepared in the same manner as in Example 1, except that the order of applying CG L and CTL was reversed. Fabricated and tested. (
However, the corona charge was set to +6KV. 〉Results are VA
= 1050V, E 1/2 = 2.9 +1
J:<・sec. In addition, the images of up to 10,000 sheets of picture test l~ were good 'C-.

Actual 1M Example 12-20 Example 11-, Main 11-F Generated Substance (1 with CG) B-1
Photoreceptors were prepared by changing the carrier transport tube (CTM) K-1 as shown in Table 1, and the electrophotographic performance was evaluated in the same manner as in Example 11. The results are shown in Table 2.

Extra colors below 1 4' = sword゛ Table 2 The CTMs in Table 2 are shown below.

-11 -12 -13 -14 -15 -18 -19 -20 [Effects of the Invention] According to the present invention, the photoconductive material constituting the photosensitive layer of the photoreceptor By using the squalium compound represented by the above general formula [I] as It is possible to produce an excellent photoreceptor that is stable against light, has sufficient sensitivity even in a long wavelength region of roughly 780 nm or more, and can also be used satisfactorily in a visible light region of 780 r+n+ or less.

Further, by using the squalium compound of the present invention, a photoreceptor having sufficient sensitivity can be provided with any combination of a wide range of carrier transport substances.

[Brief explanation of the drawing]

1 to 6 are sectional views showing examples of the mechanical structure of the photoreceptor of the present invention, and 1 to 7 in the figures represent the following, respectively. 1... Conductive support 2... Carrier generation layer 3... Carrier transport layer 4... Photosensitive layer 5... Intermediate layer 6... Layer containing carrier transport substance 7... Carrier generation material

Claims (1)

[Scope of Claims] (1) A photoreceptor comprising a photosensitive layer containing a squarium compound represented by the following general formula [I] on a conductive support. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R^0, R^1, and R^2 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxyl group, or NHY. . Y is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or -SO_2-R^6 (R^7 and R^
8 represents an alkyl group, a phenyl group, or a hydrogen atom, each of which may have a substituent. ). R^3
, R^4, R^5 and R^6 represent a hydrogen atom, an alkyl group or a halogen atom. Ar is a phenyl group, a naphthyl group, an anthranyl group, which may have a substituent,
Represents a fused polycyclic or heterocyclic ring. (2) The photoreceptor according to claim 1, wherein the photosensitive layer contains a carrier transporting substance and a carrier generating substance, and the carrier generating substance is a squarium compound represented by the general formula [I]. (3) Claim (1) or (2) wherein the photosensitive layer is constituted by a laminate of a carrier generation layer containing a carrier generation substance and a carrier transport layer containing a carrier transport substance.
) Photoreceptor described.