JPS62134652A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the relatively inexpensive sensitive body capable of fully satisfying required conditions and having an excellent durability, and easy to produce it by providing with a photosensitive layer contg. a specific compd. as an effective component on a conductive substrate body. CONSTITUTION:The photosensitive layer contg. a styrylphenylthioether compd. shown by the formula as the effective component is provided on the conductive substrate body. In the formula, R is hydrogen atom, a halogen atom, a lower alkyl, a lower alkoxy or a substd. amino group, (n) is 1 or 2. The photosensitive layer is formed by dissolving one or more kinds of the styrylphenylthioether compd. to a solution contg. a binder, and adding a sensitizing dyestuff to the obtd. solution, and then, by coating the surface of the conductive substrate body with the obtd. solution followed by drying it. The compounding amount of the styrylphenylthioether compd. is 30-70wt%, preferably 50wt% on the weight basis of the photosensitive layer. The compounding amount of the sensitizing dyestuff is 0.1-5wt%, preferably 0.5-3wt% on the weight basis of the photosensitive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a specific styryl phenyl thioether compound in its photosensitive layer.

BACKGROUND OF THE INVENTION Conventionally, inorganic materials such as ceramic acid, cadmium sulfide, and zinc oxide have been used as photoconductive materials for photoreceptors used in electrophotography. The "electrophotographic method" referred to here generally means that a photoconductive photoreceptor is first photographed in a dark place.
For example, it is charged by corona discharge, then imagewise exposed, and the charge in the exposed area is selectively dissipated to obtain an electrostatic latent image.
This is an image forming method in which this latent image area is developed and visualized with electrostatic fine particles (toner) made of colorants such as dyes and pigments and binders such as polymeric substances to form an image. be.

The basic characteristics required of a photoreceptor in such electrophotography are 1) ability to be charged to an appropriate potential in a dark place, 2) less charge dissipation in a dark place, and 3)
Examples include scales that quickly dissipate charge when exposed to light.

Incidentally, it is true that each of the above-mentioned inorganic substances has many advantages, but also has various disadvantages. For example, selenium, which is currently widely used, fully satisfies conditions 1) to 3) above, but the manufacturing conditions are difficult, the manufacturing cost is high (and the flexibility is poor).
It also has drawbacks such as being difficult to process into a belt shape and being sensitive to heat and mechanical shocks, so care must be taken when handling it. Cadmium sulfide and zinc oxide are used as photoreceptors by being dispersed in a resin as a binder, but they cannot be used as is because of mechanical drawbacks such as smoothness, hardness, tensile strength, and abrasion resistance. cannot be used.

In recent years, electrophotographic photoreceptors using various organic materials have been proposed in order to eliminate the drawbacks of these inorganic materials, and some of them have been put into practical use.

For example, poly-N-vinyl carazol and 2°4.7
-IJ nitrofluorene-9-ontocolor photoreceptor (described in U.S. Pat. No. 3,484,237), poly-
Photoreceptor made by sensitizing N-vinylcarbazole with a pyrylium salt dye (described in Japanese Patent Publication No. 48-25658)
, a photoreceptor whose main component is an organic pigment (Japanese Patent Application Laid-Open No. 47-375
43), and a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (described in JP-A-47-10735, a). Although these photoconductors Vi have excellent characteristics and are considered to be of high practical value, considering the various requirements for photoconductors in electrophotography, it is still difficult to fully meet these requirements. The reality is that we are not getting what we are satisfied with.

However, although the photoreceptors mentioned above all differ depending on the purpose or manufacturing method, generally speaking, good characteristics can be obtained by using an excellent photoconductive material.

Purpose An object of the present invention is to provide a photoreceptor that can overcome the various drawbacks of the conventional photoreceptors mentioned above and fully satisfy the conditions required in electrophotography. Another object of the present invention is to provide an electrophotographic photoreceptor that is easy to manufacture, relatively inexpensive, and highly durable.

Structure The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive support, and the photosensitive layer has the general formula (I): @/-5-CH=C)I-@ y"" (where R is a hydrogen atom, a halogen atom, a lower alkyl group,
a lower alkoxy group or a substituted amino group; n represents an integer of 1 or 2; ) It is characterized by having a photosensitive layer containing the styryl phenylthioether compound shown as an active ingredient.

As a result of research and examination on many photoconductive substances, the present inventor has found that the styryl phenyl thioether compound of the general formula (I) works effectively as a photoconductive substance for electrophotographic photoreceptors. Furthermore, as will be clear from the description below, we have also discovered that this styryl phenyl thioether compound can be combined with various materials to create photoreceptors with unexpected effects. The invention was completed based on this knowledge.

The styryl phenyl thioether compound of the general formula (1) used in the present invention is, for example, the general formula (■): [However, Y
is -P-+@), a triphenylphosphonium group represented by Xo (where X is a rogon atom) or -
It is a dialkyl phosphite group represented by PO(OR), (where R is a lower alkyl group). It is produced by reacting the phenylthiomethyl derivative represented by ] with the aldehyde compound represented by the general formula ID: (where R is the same as in the general formula (1)).

The phenylthiomethyl derivative represented by the general formula (II) can be prepared by heating the corresponding halomethyl compound with a phosphorous trialkyl or triphenylphosphine directly or in a solvent such as badruene, tetrahydrofuran, or N,N-dimethylformamide.

Alternatively, it can be easily obtained by reacting the corresponding halomethyl compound and dialkyl phosphite in ether or tetrahydrofuran in the presence of a basic catalyst such as sodium hydride or dithyllithium. Here, the alkyl group of trialkyl phosphite and dialkyl phosphite has 1 carbon number.
4, particularly methyl and ethyl groups are preferred. The reaction between the phenylthiomethyl'Jl complex represented by the general formula (Il) thus obtained and the aldehyde compound represented by the general formula (1) is as follows: It is usually carried out in the presence of a basic catalyst in a solvent at a temperature of about 100° C. from room temperature.

As basic catalysts for this reaction, mention may be made of caustic soda, caustic potash, sodium amide, sodium hydride and alcoholades such as sodium methylate and potassium t-butoxide. In addition, methanol, ethanol, isozorononol, and butanol are used as reaction solvents.

2-methoxyethanol, 1,2-dimethoxyethane,
Bis(2-methoxy7ethyl)ether.

Dioxane, tetrahydrofuran, toluene.

Xin/, dimethyl sulfoxide, N,N-dimethylformamide% N-methylpyrrolidone.

Examples include 1,3-dimethyl-2-imidazolidinone. Polar solvents 1 such as N,N-dimethylformamide and dimethyl sulfoxide are also suitable for A.

The reaction temperature is determined based on 1) the stability of the solvent used against the basic M medium, 2) the reactivity of the condensation components (compounds of general formulas (n) and 1m), and 3) the reaction as a condensing agent in the basic catalyst. You can choose widely depending on your gender. For example, when using a heron solvent, the temperature is actually between room temperature and 100°C.
Preferably the temperature is from room temperature to 80°C. However, higher temperatures may be used if the reaction time is shortened or a less active condensing agent is used.

An example of producing the styryl phenyl thioether compound represented by the general formula (1) is shown below.

Production example Diethyl phenylthiomethylphosphonate 39.0,1i
l (0.15 mol) and <-N, N-diphenylaminobenzaldehyde 41.0 g (0.15 mol) to N, N
- Dimethylformamide 500 rILt, and potassium t-butoxide 25.2 g (0,22
5 mol) and stirred at room temperature for 3 hours to react.

Dilute the reaction mixture with 1 liter of water.

The precipitated crystals were filtered, washed with water, and dried to obtain a pale yellow powder. This was recrystallized from a mixed solvent of ethyl acetate and ethanol to obtain pure 4-N,N-diphenylaminostyrylphenylthioether. Yield st, sg (yield 90
．． 6chi), mp, 88.5-90.5°C0 Elemental analysis results (as C1, H□NS): C (%)
H (%) N (@ disaster measurement Ibi U 8m44 5.38
3.62 total slander value 8128 5.58 3.6
9 All specific examples of the styryl phenyl thioether compound represented by the general formula tl) thus obtained are shown in Table 1 below.

Table-1 Compound Lagoon Structural Formula % Formula % Compound 5ぢ Structural Formula (9)
) s-cr (=cH%N+bleaching).

(13) @)-s-cH=duck) 粁CbinicH◇.

Compound A Structural Formula 6 Formula %) Compound Point -Only 21-i The photoreceptor of the present invention contains one or more of the above-mentioned styryl phenyl thioether compounds in the photosensitive layer. However, depending on the application of these steryl phenyl thioether compounds, they can be particularly used as shown in FIG. 1, FIG. 2, or FIG. 3.

The photoreceptor shown in FIG. 1 has a photosensitive layer 2 comprising a styryl phenylthioether compound, a sensitizing dye, and a binder (binder resin) on a tetraelectric support 1. The photoreceptor shown in FIG. The styryl phenyl thioether compound here acts as a photoconductive substance, and the generation and transfer of charge carriers necessary for photoattenuation take place via the styryl phenyl thioether compound. However, styryl phenylthioether compounds have almost no absorption in the visible region of light, so in order to form an image with visible light, a sensitizing dye that has absorption in the visible region is added to sensitize the compound. There is a need to.

The photoreceptor shown in FIG. 2 has a photosensitive layer 2' provided on an isoelectric support 1, in which a charge generating substance 3 is dispersed in a charge transporting medium 4 made of a styryl phenylthioether compound and a binder. It is something that The styryl phenyl thioether compound here forms the charge transport medium 4 together with the binder (or binder and plasticizer), while the charge generating substance 3 (a charge generating substance such as an inorganic or organic pigment) generates charge carriers. do. In this case, the charge:,′j.

The transport medium 4 receives the charge carriers generated by the charge generating substance 3 as raw material and is responsible for transporting the charge carriers. In this photoreceptor, the charge generating substance and the steryl phenyl thioether compound basically have absorption wavelength regions that do not overlap with each other, mainly in the visible region. This allows charge carriers to be efficiently transferred to the charge generation material 3 (to generate charge carriers, the charge carriers must reach the surface of the charge generation material).

This is because it is necessary to transmit light. -4 pitching style (1)
The styryl phenyl thioether compound represented by has almost no absorption in the visible region (and when combined with a charge generating substance 3 that generally absorbs light in the visible region and generates charge carriers, it acts particularly effectively as a charge transport substance). is its characteristic.

The photoreceptor in FIG. 3 is provided with a photosensitive layer 2'' consisting of a laminated layer of a charge generating layer N5 mainly composed of a charge generating substance 3 and a charge transporting layer 4 containing a styryl phenyl thioether compound on a conductive support 1. In this photoreceptor, light transmitted through the charge transport layer 4 reaches the charge generation layer 5, and charge carriers are generated in that region, while the charge transport wI4 receives charge carrier injection. The generation of charge carriers necessary for light attenuation is carried out by the charge generation substance 3.
The transport of charge carriers is carried out by charge transport WI4 (
Mainly styrylphenylthioether compounds act)
It will be held in Such an on-machine harp is similar to the explanation given for the photoreceptor shown in FIG.

In order to actually produce the photoreceptor of the present invention, in the case of the photoreceptor shown in FIG. 1, one or more styryl phenyl thioether compounds are t-dissolved in a solution containing a binder;
Further, a sensitizing dye is added to this to prepare a liquid, which is coated on the conductive support 1 and dried to form the photosensitive layer 2.

The thickness of the photosensitive NZ is 3 to 50 μm, preferably 5 to 20 μm.
m is appropriate. The amount of the styryl phenyl thioether compound in the photosensitive layer 2 is 30 to 70 times, preferably about 50 times, and the amount of the sensitizing agent in the photosensitive layer 2 is 0.1 to 5 times fq6. ．． Preferably 0.5~
As a 6-increase infection charge that is 3% by weight,! Lilian Green, Victoria! Lou B, Methyl Violet, Crystal Violet, Acid Violet 6B 5
rhodamine B, a triarylmethane dye.

Rhodamine 6G, Rhodamine G Extra, Eosin S
, erythrosine, rose bengal, xanthine dyes such as fluorescein, thiazine dyes such as methylene blue, cyanine, pear 7-dye R12t6-diphenyl-4-(N,N-dimethylaminophenyl)thiapyrylium verchlorate, benzene Examples include biryllium dyes such as pyrylium salt (described in Japanese Patent Publication No. 48-25658). It should be noted that these sensitizing agents may be used alone or in combination of two or more.

In addition, in order to produce the photoreceptor shown in FIG. 2, a charge generating substance IJ! The fine particles of No. 13 are dispersed, coated on the electroconductive support l, and dried to form photosensitive N2'.

The thickness of the photosensitive M2/ is 3 to 50 μm, preferably 5 to 2
0 μm is appropriate. The amount of the styryl phenylthioether compound in the photosensitive 76z' is 10 to 95% by weight, preferably 30 to 90% by weight.

Further, the amount of the charge generating substance 3 occupying the photosensitive layer 2' is 0.1
-50% by weight, preferably 1-20% by weight. Examples of the charge generating substance 3 include selenium, selenium/tellurium,
Inorganic pigments of cadmium sulfide, cadmium selenium sulfide, and α-siliconite.

Examples of organic pigments include CI Pigment Blue 25.
(Color Index Cl21180), C.I. Pigment Red 41 (CI 21200), C.I. Acid Red 52 (CI 45100).

CI Basic Red 3 (CI 45210),
Azo pigments having a carbazole skeleton (JP-A-53-95)
033), an azo pigment having a distyrylbenzene skeleton (described in JP-A-53-133445)
, an azo pigment having a triphenylamine skeleton (Japanese Unexamined Patent Publication No. 5
3-132347), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728), an azo pigment having an oxadiazole skeleton (described in JP-A-54-12742), Azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-17733), Azo pigments such as C.I. Pigment Blue 16 (described in JP-A No. 54-2129), azo pigments having a distyrylcarbazole skeleton (described in VF JP-A No. 54-14967),
Phthalocyanine pigments such as CI-74100); indigo pigments such as C.I. Pat Brown 5 (CI 734) 0) and C.I. Ino Not Dye (CI73030);

Examples include perylene pigments such as Argo Scarlet B (manufactured by Bayer) and Indance Scarlet R (Bayer 8). Note that these charge generating substances may be used alone or in combination of two or more types.

Furthermore, in order to produce the photoreceptor shown in FIG. 3, the charge generating substance 3 is vacuum-deposited on the conductive support 1, or fine particles of the charge generating substance 3 are deposited in a suitable solvent in which a binder is dissolved if necessary. The dispersion dispersed in the inside is applied and dried, and if necessary, the surface is finished and the thickness is adjusted by methods such as puff polishing to form the charge generation layer 5.
The charge transport layer 4t may be formed by applying a solution in which the seed or two or more styryl phenylthioether compounds and a binder are dissolved and drying.

The specific example of the charge generating substance 3 used to form the charge generating layer 5 is the same as that for the photosensitive layer 2'.

The thickness of the charge generating layer N5 is 5 μm or less, preferably 2 μm or less, and the thickness of the charge transport layer 4 is generally 3 to 50 μm, preferably 5 to 20 μm. When the charge generation layer 5 is of a type in which fine particles of the charge generation substance 3 are dispersed in a binder, the proportion of the fine particles of the charge generation substance 3 in the charge generation N5 is 10 to 95% by weight, preferably 50 to 90% by weight. heavy f
[About %. Further, the amount of the steryl phenyl thioether compound in the charge transport N4 is 10 to 95% by weight,
Preferably it is 30 to 90% by weight.

In the production of these photoreceptors, the conductive support 1 may include gold such as aluminum, end plates or metal foil, plastic films deposited with metal such as aluminum,
Alternatively, paper that has been subjected to conductive treatment may be used. Examples of binders include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide. is used, but any insulating and sea-contactable surface can be used. A plasticizer can be added to these binders if necessary, and examples of such plasticizers include halogenated paraffins, polychlorinated biphenyls, dimethylnaphthalene, and diptylphthalate.

Furthermore, in the photoreceptor obtained as described above, an adhesive layer or a barrier layer can be provided between the conductive support and the photosensitive layer, if necessary. For these layers, polyamide is used as a leakable material.

Nitrocellulose, aluminum oxide, etc. are used, and the film thickness is preferably 1 μm or less.

To perform copying using the photoreceptor of the present invention, after charging and exposing the surface of the photoreceptor layer, a phenomenon is performed, and if necessary,
Transfer to paper, etc. The photoreceptor of the present invention has a high sensitivity case (,
It also has many advantages such as being highly flexible.

Examples are shown below. In the examples below, all numbers are parts by weight.

Example 1 As a charge generating substance, 76 parts of Diane Blue (CI Pigment Sol-25, CI 21180), 1260 parts of a zq6 tetrahydrofuran solution of polyester resin (Vylon 200, Toyo Bosho) and 3700 parts of tetrahydrofuran in 't-/-lumyl The resulting dispersion was applied using a doctor blade onto the aluminum surface of a conductive support made of aluminum-deposited polyester paste, and air-dried to form a charge-generating layer with a thickness of approximately 1 μm. did.

On the other hand, 2 parts of a styryl phenyl thioether compound of 12 mm as a charge transport substance, 2 parts of polycarbonate resin (Panlite K 1300, manufactured by ■Yodai), and 16 parts of tetrahydrofuran were mixed and dissolved to form a solution, and this was mixed and dissolved as described above. Coat on the charge generation layer using a doctor blade and apply at 80%
℃ for 2 minutes, then dried at 105℃ for 5 minutes to a thickness of approx.
A photoreceptor, 4 melon 1, was prepared by forming a charge transport layer with a thickness of 0 μm.

Examples 2 to 15 Photoreceptors A2 to 15 were prepared in exactly the same manner as in Example 1, except that the charge generating substance and the charge generating substance (styrylphenylthioether compound) were replaced with those shown in Table 2.

Example 16 On an aluminum plate having a thickness of about 300 μm, selenium was vacuum-deposited to a thickness of about 1 μm to form a charge generation layer. Next, 2 parts of the styryl phenyl thioether compound of Jffx (22), 3 parts of polyester AI resin (Polyester Adhesive 49000 manufactured by DuPont) and 45 parts of tetrahydrofuran were mixed and dissolved to form a charge transport layer forming liquid. After coating the above charge generation layer (selenium vapor deposition layer) using a doctor blade and drying naturally,
A charge transport layer having a thickness of about 10 μm was formed by drying under reduced pressure to obtain a photoreceptor A 16 of the present invention.

Example 17 A charge generation layer (however, the thickness was approximately 0.3 μm) was formed using a perylene pigment instead of selenium, and a styryl phenyl thioether compound was
Photoreceptor 17 was prepared in exactly the same manner as in Example 16 except that A (27) was used instead of photoreceptor 22).

Example 18 A mixture of 1 part of Dia/Blue (same as used in Example 1) and 158 parts of tetrahydrofuran was ground and mixed in a mail mill, and then styrylphenyl thioether of a(z4) was added to the mixture. 12 parts of compound, polyester resin (Polyester Adhesive 49000 manufactured by DuPont)
) and further mixed to obtain a photosensitive layer forming solution, which was applied onto an aluminum vapor-deposited ester film using a doctor blade, and dried at 100°C for 30 minutes to form a photosensitive layer with a thickness of about 16 μm. In this manner, a photoreceptor body 18 of the present invention was created.

The photoreceptors black 1 to 21 made by
Corona discharge was performed for 20 seconds using s[) at -6 KV or n +6 KV c7) (after letting W relax, discharge was performed in a dark place for 20 seconds, and the surface potential VP at that time.

(2 lux), then irradiate the photoreceptor surface with tungsten lamp light so that the illuminance becomes 45 lux, and find the time (seconds) until the surface potential reaches vPoOi.
Exposure RE 3A (looks 9 seconds) was calculated. The results are shown in Table-3.

In addition, after each of the photoreceptors described above is formed into a band 14 using a commercially available electrophotographic copying machine, light is irradiated through the original image to form an electrostatic latent image, and the image is developed using a dry developer. When the resulting two-speed (toner images) were electrostatically transferred onto plain paper and fixed, a clear transferred image was obtained. Even when a wet developer is used as the developer, the transferred image I'J is equally clear! ,
was gotten.

(The following is a blank space) Table 3 Effects As stated above, the photoreceptor of the present invention has the general formula (I)
By using the styryl phenylthioether compound represented by the formula, the conditions required for a photoreceptor are fully satisfied and clear images are formed.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views enlarged in the thickness direction of an electrophotographic photoreceptor according to the present invention. 1... Conductive support z, z', z'... Photosensitive layer 3... Charge generating substance 4... Charge transporting medium or core transport layer 5... Charge generating layer

Claims (1)

[Claims] 1. General formula (I) on the conductive support: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R is a hydrogen atom, a halogen atom, a lower alkyl group,
a lower alkoxy group or a substituted amino group; n represents an integer of 1 or 2; ) An electrophotographic photoreceptor comprising a photosensitive layer containing a styryl phenyl thioether compound as an active ingredient.