JPS63271460A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To increase the sensitivity of a sensitivity body by using a specified bisthiazolylbenzene deriv. as an electric charge transferring substance. CONSTITUTION:A single layer or double layer type photosensitive layer contg. an electric charge transferring substance (A) and an electric charge generating substance (B) is formed on an electrically conductive support and a bisthiazolylbenzene deriv. represented by the formula is used as the substance A. In the formula, each of R1 and R2 is H, halogen, alkyl, (substd.)amino or the like and each of A1-A4 is H, halogen, alkyl, (substd.)aryl or the like. A concrete example of the substance A is 1,4-bis[4-(p-dipropylaminophenyl)- thiazoline-2]benzene and that of the substance B is tau type metal-free phthalocyanine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic photoreceptor having excellent electrophotographic properties.

(Prior Art) In an electrophotographic photoreceptor that uses a photoconductive substance as a photosensitive material, conventional photoconductive substances are used as photoconductive substances.

Inorganic photoconductive materials such as selenium, zinc oxide, titanium oxide, and cadmium sulfide have been mainly used.

However, many of these are generally highly toxic and there are problems in how to dispose of them.

On the other hand, the use of organic photoconductive compounds is generally less toxic than the use of inorganic photoconductive substances, and is also advantageous in terms of transparency, flexibility, light weight, and cost. It has been widely studied recently.

(Problems to be Solved by the Invention) However, overall, electrophotographic photoreceptors using organic photoconductive substances as photosensitive materials have not yet achieved sufficient characteristics, particularly in terms of sensitivity.

One of the major reasons for this is that no material suitable for transporting charges within the photosensitive layer has been found.

(Means for Solving the Problems) The present invention provides a novel high-sensitivity electrophotographic photoreceptor using a novel high-sensitivity charge transport material that has been investigated and discovered in order to solve the above-mentioned problems. It is.

That is, the present invention provides an electrophotographic photoreceptor in which a layer containing a charge transporting substance and a charge generating substance is provided on a conductive support, in which the charge transporting substance has the following general formula +1) [wherein Rt and Rz h, respectively] It independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted amino group. Ate Ale A3 and A4 are each independently a hydrogen atom, ) and a rogen atom.

An electrophotographic photoreceptor containing a bithiazolylbenzene derivative represented by an alkyl group, an alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. .

The bithiazolylbenzene derivative represented by the general formula (1) will be explained in detail.

In the formula, Rs and R2 each independently represent a hydrogen atom, a fluorine atom,
Halogen atoms such as chlorine atoms, bromine atoms, iodine atoms,
Methyl group, ethyl group, n-propyl group.

It may be an alkyl group such as 1so-propyl group, n-butyl group, or n-7mil group, or an alkoxy group such as methoxy group, ethoxy group, or butoxy group, or an amine group, dimethylamino group, diethylamine group, or dipropylamino group. It may be a di-substituted amino group such as a group, a diphenylamino group, or a dibenzylamine group.

Ale At, As and A4 may each independently be a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a substituted or unsubstituted amino group, etc., and may also be a substituted or unsubstituted amino group. may be an aryl group or an aralkyl group. The aryl group mentioned here is, for example, a phenyl group or a biphenyl group.

It means a naphthyl group, an anthryl group, a phenanthryl group, etc., and an aralkyl group is, for example, a pen/zyl group.

It means a 7enethyl group, a naphthylmethyl group, etc.

These groups may be used as they are, or may be substituted with one or more of the aforementioned halogen atoms, alkyl groups, alkoxy groups, amino groups, di-substituted amino groups, and the like.

Typical examples of the bithiazolylbenzene visiting conductor represented by the general formula ([1) used as the charge transport material of the present invention are illustrated below.

The charge transport substance represented by the general formula +1) can be obtained, for example, by condensing 1 mole of substituted or unsubstituted terephthalic acid dithioamide with 2 times the mole of α-halogen ketone as shown in the reaction formula below.

Specific synthesis examples are shown below.

120ml of 0.2g of terephthalic acid dithioamide! of nitrobenzene, and further added 0.459 ω-promacetophenone and heated to 200°C.

After cooling for 2 hours, the precipitated product was filtered and crystallized in glacial acetic acid to obtain 0.3 g of the desired 1,4-bis[4-phenyl-thiazolyl-+2)-benzene.

The electrophotographic photoreceptor of the present invention contains at least one of the above-mentioned bisthiazolylbenzene derivatives represented by the general formula (1) as a charge transport material in the photosensitive layer. In addition to the bisthiazolylbenzene derivative represented by the general formula +1) as a charge transport substance, conventionally known low-molecular compounds such as oxazole, virasorin, hydrazone, stilbene, carbazole, triphenylamine, oxadiazole, etc. Derivatives, Bo! j-
N-vinylcarbazole, polyvinylanthracene.

High molecular compounds such as polyvinyl acridine, derivatives thereof, and charge transport substances are also used in an amount of 10 parts by weight per 100 parts by weight of the bisthiazolylbenzene derivative represented by the general formula (1).
They can also be used together in an amount of 0 parts by weight or less. If it exceeds 100 parts by weight, sensitivity decreases.

Since the bisthiazolylbenzene derivative represented by the general formula (1) according to the present invention has almost no absorption for light with a wavelength of 500 nm or more, it is usually used as a charge-generating substance, that is, a substance that reacts sensitively to light and generates a charge. The generated substances are used together to form an electrophotographic photoreceptor.

Substances that generate charges include azoxybenzene, bisazo, trisazo, benzimidazole, polycyclic quinoline, and indigoid.

Pigments known to generate electric charge upon irradiation with light, such as quinacridone-based, phthalocyanine-based, naphthalocyanine-based, perylene-based, and methine-based pigments, can be used. These pigments are described in, for example, JP-A-47-37543, JP-A-4
7-37544, JP-A-47-18543, JP-A-47-18544, JP-A-48-43942, JP-A-48-70538, JP-A-49-1231, JP-A-49- No. 105536, JP-A-50-75214,
It is disclosed in Japanese Patent Application Laid-Open No. 50-92738. In particular, τ and τ described in JP-A-58-182640 and European Patent Application Publication No. 92,255.
-η and η' type gold metal phthalocyanine has high sensitivity to long wavelengths and is useful as a material for printers equipped with diode lasers. There is no particular restriction as long as it is an organic compound that has the function of generating a stain carrier upon irradiation with light.

The charge-generating substance described above may be a single-layer photosensitive layer containing the charge-transporting substance of the present invention in the same layer, or a layer containing the charge-generating substance (charge-generating layer) and the charge-transporting substance. A two-layer laminated structure in which layers (charge transport layers) are separated may be used. When the photosensitive layer is a layered type, the charge generating material 10i
The charge transport material is preferably contained in an amount of 50 to 1000 parts by weight per i part. In other ranges, the electrophotographic properties deteriorate. In the case of a two-layer type, it is also possible to contain a charge transport substance in the charge generation layer and a charge generation substance in the charge transport layer in an amount of up to 30% by weight, respectively.

Furthermore, the order in which the charge generation layer and charge transport layer are stacked is arbitrary, whether the layer is on the top or the bottom, but in terms of the printing life of the electrophotographic photoreceptor, it is better to form the charge transport layer on top of the charge generation layer. is preferred.

Regardless of whether the photosensitive layer is a single layer or consists of two layers, a charge generation layer and a charge transport layer, each layer contains binders, plasticizers, A fluidity imparting agent, a pinhole inhibitor, etc. can be used as necessary.

Examples of the binder include silicone resin, polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polystyrene resin, acrylic resin, and methacrylic resin. Heat and/or photocurable resins can also be used. In any case, there is no particular restriction as long as the resin is electrically insulating and can form a film under normal conditions. When the photosensitive layer is a layered type, the amount of binder used is 50 to SOO parts by weight based on 100 parts by weight of the charge generating material and the charge transporting material.

In the case of a two-layer type, the amount is preferably 500 parts by weight or less per 100 parts by weight of the charge generating material in the charge generation layer, and the range of 50 to 500 parts by weight per 100 parts by weight of the charge transporting material in the charge transport layer. Outside these ranges, electrophotographic properties such as chargeability and sensitivity tend to become unbalanced.

Examples of plasticizers include halogenated paraffin, dimethylnaphthalene, and dibutyl phthalate. Examples of fluidity imparting agents include Modaflow (manufactured by Monsando Chemical Co., Ltd.) and Acronal 4F (manufactured by Pasuf Co., Ltd.), which are used as abrasion and pinhole inhibitors. is benzoin.

Examples include dimethyl phthalate. these are.

It is preferable to use 5 folds or less in each layer.

On the other hand, the conductive support according to the present invention is a conductive material such as conductively treated paper or a plastic film, a plastic film laminated with a metal foil such as aluminum, a metal plate, or a metal drum.

The electrophotographic photoreceptor of the present invention can be obtained by forming a photosensitive layer on the above-mentioned conductive support.

When the photosensitive layer is a layered type, a charge generating substance, a charge transporting substance,
It can be formed by uniformly dissolving or dispersing a binder, and optionally an additive, in a solvent such as acetone, methyl ethyl ketone, tetrahydrofuran, toluene, xylene, methylene chloride, trichloroethane, etc., followed by coating and drying.

A double-layered hot water bath with a photosensitive layer! The charge generation layer is formed by vacuum deposition of a charge generation material or a charge generation material or a binder.

Optionally, it can be formed by uniformly dissolving or dispersing the additive in the above-mentioned solvent, then coating and drying. The charge transport layer is 'W1 charge transport material, binder.

Optionally, it can be formed by uniformly dissolving or dispersing the additive in the above-mentioned solvent, then coating and drying.

Next, the thickness of each layer is 5 to 50 μm if the photosensitive layer is a layered type.
It is preferable that m9% is 8 to 20 μm. If it is less than 5 μm, the initial potential tends to be low, and if it exceeds 50 μm, the sensitivity tends to decrease. When the photosensitive layer is a two-layer type, the charge generation layer has a thickness of 0.001 to 10 μm.

Particularly preferred is 0.2 to 5 μm. If it is less than 0.001 μm, the sensitivity tends to be low, and if it exceeds 10 μm, the residual potential tends to be high. The charge transport layer has a thickness of 5 to 50 μm.

Particularly preferred is 8 to 20 μm. If the thickness is less than 5 μm, the initial potential tends to be low, and if it exceeds 50 μm, the sensitivity tends to decrease.

The electrophotographic photoreceptor of the present invention may further have an adhesive layer, barrier layer or subbing layer immediately above the conductive support, and may also have a protective layer on the surface of the photosensitive layer. good.

When copying or printing is performed using the electrophotographic photoreceptor of the present invention, the surface is charged in the same manner as before.

After exposure, development is performed, and the image is transferred onto a transfer material such as plain paper and fixed.

(Example) Next, the present invention will be explained based on examples.

The present invention is not limited to this.

Each material used in the examples below is listed below. Abbreviations are shown in parentheses.

(1) Charge-generating organic pigment τ-type metal-free phthalocyanine (τ-hhPc) (2) Charge transport substance 01.4-bis(4-(p-dipropylaminophenyl)-thiazoline-2]benzene (BTB- 1) 01.4-bis(5-(3,4,5-)rimethoxyphenyl)thiazoline-2]-benzene (BTB-2) (3) Binder O silicone face: Ni-255 [Shin-Etsu Chemical Co., Ltd. ■Product name] o Polyester resin: Vylon 200 [Toyobo ■Product name] Example 1 f-H Hiroshi PC2.0g, Siri: ff-7')2,<4
．． 0 g and tetrahydrofuran 949 were kneaded for 8 hours using a ball mill (3-inch bot mill manufactured by Nippon Kagaku Co., Ltd.). The obtained pigment dispersion was applied onto an aluminum plate (thickness: 0.1 mha) using an applicator.

It was dried at 100° C. for 15 minutes to form a charge generation layer with a thickness of about 0.5 μm.

Next, KBTB-1sg and polyester resin 159 were mixed in tetrahydrofuran 2009. The resulting liquid was applied onto the charge generation layer using an applicator and dried at 90° C. for 20 minutes to form a charge transport layer with a thickness of about 10 μm.

Example 2 A charge generation layer similar to that in Example 1 was formed. BT on top of that
B-259 and polyester resin 159 in methylene chloride 1
209,1,1.2-) A solution added to a mixed solvent of 609 lychloroethane and 509 tetrahydrone was applied using an applicator.

It was dried at 115° C. for 30 minutes to form a charge transport layer with a thickness of about 10 μm.

Example 3 τ-I4tPCI, og, BTB-1,509, 15 g of polyester resin, methylene chloride 1209, 1° 1.2
- trichloroethane 609 and nato2hydrofuran 50
The mixture of No. 9 was kneaded using a ball mill for 10 hours. The resulting dispersion was applied onto an aluminum plate using an applicator and dried at 120° C. for 15 minutes to produce a single-layer electrophotographic photoreceptor having a film thickness of 10 μm. .

The electrophotographic properties of the obtained electrophotographic photoreceptor were measured using an electrostatic recording paper tester (5P-428 manufactured by Kawaguchi Denki), and the results are shown in Table 1.

In addition, the initial potential Vo (V) in the table indicates the charging potential when a negative or positive 5KV corona is discharged for 10 seconds in dynamic measurement, and the dark decay Vx indicates the potential retention rate when left in the dark for 30 seconds. Shows e ESO is 10 lu
It shows the amount of light (j'x-s) required for the electric potential to drop by 50 degrees when irradiated with x white light. Residual potential VRfV) is 10
The surface potential after irradiation with lux white light for 30 seconds is shown.

Table 1 Electrophotographic characteristics % represents charge polarity.

As shown in Table 1, it can be seen that the electrophotographic photoreceptor in which the bisthiazolylbenzene derivative represented by the general formula (1) according to the present invention is used as a charge transport material has good electrophotographic properties.

(Effects of the Invention) The electrophotographic photoreceptor of the present invention has excellent electrophotographic properties.

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor in which a layer containing a charge transport substance and a charge generation substance is provided on a conductive support, the charge transport substance has the following general formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼(I) [In the formula, R_1 and R_2 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted amino group, and A_1, A_2, A_3 and A_4 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group]. An electrophotographic photoreceptor comprising: 2. The electrophotographic photoreceptor according to claim 1, wherein the charge transport material and the charge generation material are each contained in separate layers. 3. The electrophotographic photoreceptor according to claim 1, wherein the charge transport material and the charge generation material are contained in the same layer.