JPS605940B2 - Photosensitive materials for electrophotography - Google Patents

Description

[Detailed description of the invention] The present invention relates to a light-sensitive material for electrophotography.

Specifically, the present invention relates to an electrophotographic light-sensitive material containing an organic photoconductive polymer and having excellent sensitivity. Traditionally, inorganic photoconductive materials such as selenium, selenium-tellurium alloy, cadmium sulfide, and zinc oxide have been used as photosensitive materials for electrophotography, but in recent years, flexible, lightweight, and transparent materials have become available. Organic photoconductive polymers, which have characteristics not found in inorganic materials, have attracted attention, and some have been put into practical use.

Generally, organic photoconductive polymers themselves have low sensitivity and have a narrow range of sensitive wavelengths, so it is necessary to add a sensitizer to expand the range of sensitive wavelengths and increase sensitivity. However, not many sensitizers are known that provide practical sensitivity comparable to that of inorganic photoconductive substances such as selenium. Ionic dyes such as triarylmethane, pyrylium, and benzopyrylium are known as sensitizers that provide practical sensitivity.

However, since these ionic dyes generally have low light resistance, it is difficult to apply them to applications where they are used repeatedly, such as electrophotographic photoreceptors. Therefore, the present inventors conducted repeated research in order to find a suitable sensitizer for organic photoconductive polymers, and found that a specific azo compound was effective, resulting in the present invention.

That is, the gist of the present invention is the general formula or general formula (b) (wherein, R represents a substituted or unsubstituted hydrocarbon residue, and D represents a substituted or unsubstituted aromatic hydrocarbon group). The present invention relates to an electrophotographic light-sensitive material characterized in that it contains an azo compound represented by a hydrogen atom, a halogen atom, a hydroxyl group, or a nitro group, and an organic photoconductive polymer.

The present invention will be described in detail below. The light-sensitive material of the present invention contains a compound represented by the general formula (1) or (0) as a sensitizer.

In general formulas (1) and (0), R is a substituted or unsubstituted hydrocarbon tricarbon residue, specifically a methyl group, an ethyl group, a linear or branched propyl group, Alkyl groups such as butyl, bentyl, hexyl; hydroxyalkyl, alkoxyalkyl, alkoxycarbonylalkyl, acyloxyalkyl, alkyl, alkoxyalkoxyalkyl, aryloxyalkyl, acyloxyalkyl group, cyanoalkyl group, aminoalkyl group, N・N-dialkylaminoalkyl group, alkylaminoalkyl group, halo 4
Alkyl groups having substituents such as genated alkyl groups, carboxyalkyl groups, morpholinoalkyl groups, alkylthioalkyl groups, arylthioalkyl groups; cycloalkyl groups such as cyclohexyl groups; penzyl groups,
Aralkyl groups such as phenethyl; aryl groups such as phenyl, chlorphenyl, methoxyphenyl, nitrophenyl, tolyl, xylyl, alkylaminophenyl and the like. In general formulas (1) and (0), D is a substituted or unsubstituted aromatic hydrocarbon group, specifically a monocyclic or polycyclic group such as a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, or an acenaphthene ring. Examples include ring aromatic hydrocarbon groups.

In addition to the nitro group, cyano group, and carboxy group, the substituents bonded to these rings include halogen atoms such as chloro atom and prom atom, or methyl group, ethyl group, trifluoromethyl group, and 8-hydroxyethyl group. substituted or unethical alkyl groups; aryl groups such as phenyl; alkoxy groups such as methoxy and ethoxy; aryloxy groups such as phenoxy; methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl; alkoxycarbonyl groups such as; methoxyshethoxycarbonyl groups, alkoxyalkoxycarbonyl groups such as ethoxyshethoxycarbonyl groups; alkoxyalkoxyalkoxycarbonyl groups such as ethoxyshethoxyethoxycarbonyl groups; dimethylamino groups, methylhydroxy Amino groups such as ami/group, dibenzylamino group, phenylamino group, morpholino group; Acyl group such as acetyl group, benzyl group; Acylamino group such as acetylamino group, benzoylamino group; Methylsulfonyl group, ethylsulfonyl group an alkylsulfonyl group such as a phenylsulfonyl group; an aminosulfonyl group such as a methylaminosulfonyl group, a butylaminosulfonyl group, a jetylaminosulfonyl group, a methylaminocarbonyl group, a jetylaminocarbonyl group Examples include aminocarbonyl groups such as.
Furthermore, in general formulas (1) and (0), XI to X3 are hydrogen atoms, halogen atoms, hydrogen groups or nitro groups,
All of XI to X3 do not need to be of the same type.

Among these azo compounds, particularly suitable ones are exemplified from those used in the examples: azo compounds [3] and [5].
], [6], [8], [11], [16] ~ [21],
[25], [26], [29], etc.

The azo compounds represented by the general formulas (1) and (b) can be produced according to known methods. (Tokuko Showa 3
For example, general formula (m) or general formula (W) (wherein R and XI to X3 have the same meaning as general formulas (1) and (b)) 4 or 3-hydroxynaphthalimide represented by (having) and the general formula (V) D-N ratio...
...(V) (wherein D has the same meaning as in general formulas (1) and (b)) can be produced by coupling reaction with a diazonium salt of an aromatic amide.

Substituents on the nucleus of the coupling component and the diazo component may be provided before the coupling reaction, or may be subjected to, for example, halogenation, nitration, acylation, etc., according to a conventional method after the coupling reaction. Of course, naphthalic acid derivatives represented by general formula (W) or general formula (blood) (wherein D and XI to X3 have the same meanings as general formulas (1) and (0)) or its anhydride , general formula (wind) ratio N-R... (skin) (wherein, R has the same meaning as in general formulas (1) and (b).

It can also be produced by condensing amines represented by ) in an organic solvent or in an aqueous medium. Various well-known organic photoconductive polymers can be used as the organic photoconductive polymer that can be used in the photosensitive material of the present invention.

For example, polymers containing multiple rings such as carbazole, indole, oxadiazole, pyrazoline, naphthalene rings,
Examples include polymers containing polynuclear aromatic rings such as anthracene rings. More specifically, polymers such as polyvinylanthracene, polyacenaphthylene, polyvinylpyrene, polyvinylcarbazole, polypynylacridine, polypyrenylmethylvinyl ether, polyglycidylcarbazole, polymethylenepyrene, polycarbazolylethylvinyl ether, etc. Copolymers: as well as these chloro,
Substituted derivatives such as bromine, methyl, and dimethylamino may be mentioned. Among these, polymers containing carbazole and pyrene are particularly preferred. Of course, combinations of two or more different polymers can also be used. In the present invention, the amount of the azo compound represented by the general formula (1) or (D) can be selected from a wide range, but it is usually 0.0000 to 1 mole of organic photoconductive monomer unit in the polymer. 000
It is selected from the range of 1 to 1 mol, particularly 0.001 to 0.3 mol.

By using a mixture of two or more different azo compounds represented by the general formula (1) or (0), it is also possible to improve the sensitivity compared to when each is used alone. The light-sensitive material of the present invention may contain a known sensitizing agent other than the azo compound represented by the general formula (1) or (0).

In particular, the use of a sensitizer with a sensitivity wavelength range different from that of the azo compound represented by the general formula (1) or (0) is effective for further improving sensitivity. Examples of such sensitizers include Lewis acids and dyes that form a charge transfer collar with the organic photoconductive polymer. Lewis acids include chloranil, 2,3-dichloro-1,4 naphthoquinone, 2
1-methylanthraquinone, 1-nitroanthraquinone,
Quinones such as 1-chloro-5-nitroanthraquinone, 2-chloroanthraquinone, phenanthrenequinone4
-Aldehydes such as nitrobenzaldehyde, ketones such as 9-penzoylanthracene, indadione, 3,5-dinitrobenzophenone, 3,3',5,5-tetranitrobenzophenone, phthalic anhydride, 4-chloronaphthalic anhydride, etc. acid anhydride, tetracyanoethylene,
Cyano compounds such as terephthalalmalononitrile and 4-nitrobenzalmalononitrile; 3-benzalphthalide,
3-(Q-cyano p-nitrobenzal) phthalide, 3
1 (Q-cyano p-nitrobenzal)-4・5・6・
Examples include electron-withdrawing compounds such as phthalides such as 7-tetrachlorophthalide.

Examples of dyes include triphtanylmethane dyes such as methyl violet, brilliant green, and crystal violet, thiazone dyes such as methylene blue, quinone dyes such as quinizarin, cyanine dyes, pyrylium salts, thiapyrylium salts, and benzopyrylium salts.

The amount of Lewis acid and dye to be used is according to the general formula (1) or (0
) varies depending on the amount of azo compound used, but
It is usually selected from the range of 0.0001 to 1 mol, particularly 0.001 to 0.5 mol, per mol of the organic photoconductive monomer unit of the polymer.

In addition, inorganic photoconductive particles such as selenium and selenium-arsenic alloy; organic photoconductive pigments such as copper phthalocyanine and thioindigo may also be contained. Furthermore, the photosensitive material of the present invention may contain well-known plasticizers and binder resins to improve film formability, flexibility, and mechanical strength when used as a photoreceptor or film for a copying machine. good.

As plasticizers, phthalate ester, phosphate ester,
Examples include aromatic compounds such as epoxy compounds, chlorinated paraffins, chlorinated fatty acid esters, and methylnaphthalene.As binder resins, polyesters, polyacrylic acid esters, polymethacrylic acid esters, polystyrene, cellulose-stable cellulose esters, etc. These include various polymers, and these are appropriately selected depending on the type of organic photoconductive polymer used. When the photosensitive material of the present invention is used, for example, as a photoreceptor for electrophotography, it may contain an azo compound represented by the general formula (1) or (0), an organic photoconductive polymer, and, if necessary, a compound as exemplified above. After forming a coating solution by dissolving various components in a solvent according to a conventional method, this is coated onto a conductive or conductive-treated support to form a film with a thickness of several meters to several tens of micrometers, forming a photoconductor. Commonly used by forming layers.

The solvent for forming the coating solution is selected as appropriate depending on the type of organic photoconductive polymer used, but commonly used are halogenated hydrocarbons such as 1,2-dichloroethane and dichloromethane, tetrahydrofuran, dioxane, etc. Ketones such as methyl ethyl ketone and cyclohexane; Aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; Esters such as ethyl acetate; amides such as dimethylformamide; Of course, the solvent may be a mixture of two or more.

The solvent does not necessarily have to completely dissolve the azo compound represented by the general formula (1) or (0).
The amount of solvent used varies depending on the type of organic photoconductive polymer, the required film thickness of the photoconductive layer, and other factors, but it is usually 1 to 100 times the weight of the organic photoconductive polymer, especially 3
~30 times the weight is used. The support on which the photoconductor layer is formed may be a drum made of metal such as aluminum or copper;
Examples include sheets, metal foil laminates, vapor deposits, and the like.

In addition, by applying conductive properties such as metal powder, carbon black, ionized steel, and polymer electrolytes together with a suitable binder,
Examples include plastic films and paper whose surfaces have been subjected to conductive treatment. It goes without saying that the photoreceptor obtained using the inventive photosensitive material may have an adhesive layer, a transparent insulating layer, etc., if necessary.

The photosensitive material of the present invention has been described in detail above, and since the photosensitive material of the present invention has very high sensitivity and the sensitizer it contains has excellent light resistance, it is suitable for electrophotographic copying machine photoreceptors and the like.

EXAMPLES Next, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 Polyvinylcarbazole (manufactured by Takasago International Co., Ltd., trade name: Tuv)
ico1210) 1.0 to 1,2-dichloroethane 1
0 dissolved in me.

Then, the following general formula (K) in which R and D are shown in Table 1
A coating solution was prepared by adding 0.1 part of an azo compound corresponding to the above. This coating solution was applied onto a sand-supported aluminum slope using a Baker applicator so that the film thickness after drying was 10 μm, and dried to obtain an electrophotographic photoreceptor.

Regarding this photoreceptor, the sensitivity, that is, the half-decreased exposure amount (E, /2
), the results shown in Table 1 were obtained.

The half-decreased exposure amount was determined using an electrostatic copying paper testing device (Model SP-428 manufactured by Oil Kuchi Denki Seisakusho). First, the photoreceptor was charged by Juro V's corona discharge on the floor, and then exposed to white light to determine the surface potential. It was determined by determining the amount of exposure required to attenuate to half of the initial surface potential. -C4day9 (d is n-butyl group, -C4day9(i) in Table 1)
represents an isoptyl group.

Example 2 A photoreceptor was manufactured in exactly the same manner as in Example 1 except that an azo compound having the following structure (azo compound abbreviation [29]) was used for 0.1 days.
was 401ux·sec.

Example 3 1.0 mm of a polymer (substitution rate: 85 mol %) in which the chlorine atoms of polyepichlorohydrin were partially substituted with carbazole rings by a polymer reaction was dissolved in 10 mm of 1,2-dichloroethane.

Next, Example INo. Azo compound used in 18 [18]
A coating solution was prepared by adding 0.1 ta of . A photoreceptor was manufactured using this coating solution in the same manner as in Example 1, and the sensitivity was measured, and E,'2 was 48 f/sec. Example 4 To 1.0 tera of polyvinylcarbazole, the two azo compounds used in Example 1 were mixed in combinations shown in Table 2 at 0.0 tera each.
A coating solution was prepared in the same manner as in Example 1, except that the coating solution was used on the day of May 2005, and a photoreceptor was manufactured.

When the sensitivity (E, /2) of this photoreceptor was measured, the results shown in Table 2 were obtained. From a comparison of Tables 1 and 2, it is clear that the sensitivity is improved when two different azo compounds are used, compared to when they are used alone. Table 2 Example 5 Parts by weight of polyvinylcarbazole 10, azo compounds used in Example 1 of the types and amounts shown in Table 3, sensitizers other than the azo compounds of the types and amounts shown in Table 3, and 1. A coating solution was prepared and a photoreceptor was produced in exactly the same manner as in Example 1, except that 125 parts by weight of 2-dichloroethane was used.

When the sensitivity (E, /2) of this photoreceptor was measured, the third
The results shown in the table were obtained. Table 3 Example 6 Polyvinylcarbazole 5.0% was dissolved in 1,2-dichloroethane 50%, and Example I No. 6 was dissolved in this solution. 20
Azo compound used in [20] 0.5 minutes, epoxy resin (
A coating solution was prepared by adding and mixing 0.5 μl of Piquat 828 (trade name, manufactured by Shell Co., Ltd.) and 0.25 μl of polybutyl methacrylate (trade name: DIANAL BR-102, manufactured by Mitsubishi Rayon Co., Ltd.).

This coating solution was applied to the aluminum surface of a support made by laminating a 10 µm aluminum foil to a 75 µm polyethylene terephthalate film in the same manner as in Example 1, and dried to produce a photoreceptor. When the sensitivity of this photoreceptor was measured, it was found to be E,/
2 was similar to 6.21 seconds.

This photoreceptor was charged in a dark place by corona discharge with an applied voltage of Juro V, exposed to a maximum light intensity of 301 seconds, and then developed and transferred using a magnetic brush method. Image obtained.

Claims (1)

[Claims] 1 General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Or general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R is substituted or unsubstituted carbonized Indicates a hydrogen residue,
D represents a substituted or unsubstituted aromatic hydrocarbon group, and
1. A photosensitive material for electrophotography, characterized in that it contains an azo compound represented by the following formula (1 to X^3 represent a hydrogen atom, a halogen atom, a hydroxyl group, or a nitro group) and an organic photoconductive polymer.