JPS62201448A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To extremely enhance the sensitivity of a photosensitive body by adopting a specified indoline compound as an electrostatic charge transfer material. CONSTITUTION:The charge transfer material to be used is the indoline compound represented by formula I in which each of Ar and Ar' is phenyl optionally substituted by halogen, alkyl, alkoxy, or nitro, and X is a group having an indoline ring. When a layer containing the charge generating pigment and on this layer a layer containing the charge transfer material are formed on a conductive substrate, the indoline compound is used in an amount of 50-300wt% of the resin, and if above this range, the photosensitive body becomes unfavorable in respects of light fatigue and ozone resistance, and if below the range, satisfactory sensitization cannot be obtained. When the charge generating pigment is dispersed into the charge transfer medium, this pigment is used in an amount of 5-100wt% of the binder resin, and the indoline compound is dispersed or mutually dissolved in the resin in an amount of 40-150wt% of the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor, and more particularly to a photoreceptor having excellent electrophotographic sensitivity by containing a specific charge transporting substance.

(Prior Art) Conventionally, charge transport materials for photoreceptors (hereinafter sometimes referred to as OPC) mainly containing organic pigments include poly-N-vinylcarbazole, 2.5-bis(4-diethylaminophenyl)-1, 3゜4-oxadiazole and 2,4.7-
Various electron transport substances or hole transport substances such as 1-linitrofluorenone are known.

(Technical problem to be solved by the invention) Although the above-mentioned charge transport substance has a sensitizing effect depending on the photoconductive material used in combination, it is still not sufficient when considering the design of a more practical photoreceptor. It was something.

(Means for Solving the Problems) The present invention uses a specific indoline compound represented by the following general formula as a charge transport substance used in OPC. That is, as a charge transport substance, in the following general formula, Art s Art is a substituted or unsubstituted phenyl group, a halogen atom, an alkyl group, an alkoxy group, or a nitro group is used as a substituent, and X is a group having an indoline ring. A styrene compound represented by is used.

(Function) By using the above-mentioned indoline compound as a charge transport material, a remarkable sensitizing effect can be achieved compared to photoreceptors that use conventional charge transport materials such as poly-N-vinylcarbazole. can get. The fact of this effect will be explained in detail in the Examples shown below, but the sensitivity for the I compound can be summarized as shown in the following table.

Table 1 From Table 1, it is clear that the indoline compound of the present invention exhibits particularly excellent effects as a charge transport substance.

(Effects of the Invention) The present invention makes it possible to significantly increase the sensitivity of a photoreceptor by employing the above-mentioned specific indoline compound as a charge transporting substance.

Therefore, when a photoreceptor containing this charge transporting substance is used in an electrophotographic copying machine, a laser printer, etc., the sensitivity is fast and clear copies without fog can be obtained.

Further, the photoreceptor can be manufactured at a lower cost than when Se or a-3t is used, and the copying speed can be increased compared to a photoreceptor of the same cost.

(Embodiment) The photoreceptor of the present invention contains a charge-generating pigment layer (CGL) on a conductive substrate and a charge-transporting substance thereon, as long as the above-described specific indoline compound is used as a charge-transporting substance. Any of the types can be used, such as a type in which a resin layer (CTL) is provided, and a type in which a composition in which a charge generating pigment is dispersed in the charge transport medium is provided on a conductive substrate.

As the resin used for forming the photosensitive layer, any resin conventionally used in this field, such as epoxy resin, silicone resin, urethane resin, acrylic resin, saturated polyester resin, polycarbonate resin, alkyd resin,
Examples include electrically insulating resins such as vinyl resins and photoconductive resins such as polyvinylcarbazole.

In the case of the above-described first type of photoreceptor, that is, a functionally separated multilayer photoreceptor, charge-generating pigments such as phthalocyanine pigments, perylene pigments, disazo pigments, trisazo pigments, and quinacridone pigments are coated on a conductive substrate. The layer is formed as a vapor deposited layer or a resin pigment dispersion layer, and a charge transport layer containing the above-mentioned indoline compound is provided thereon.

In this case, the indoline compound is added at 5 parts by weight per 100 parts by weight of the resin.
It is used in an amount of 0 to 300 parts by weight, preferably 70 to 150 parts by weight. When the amount is more than the above range, it is unfavorable in terms of photo fatigue and ozone resistance, and when it is less than the above range, sufficient sensitization is not observed.

In addition, in the second type of photoreceptor described above, that is, a type in which a charge-generating pigment is dispersed in a charge transport medium, the charge-generating pigment is contained in 5 to 100 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the binder resin. The indoline compound is dispersed or dissolved in an amount of 40 to 150 parts by weight, preferably 70 to 100 parts by weight.

The indoline compound used in the present invention is represented by the above-mentioned general formula, and for example, a compound having the following structural formula can be produced. O etc. are used. Among these, No, 2.3, 6, 7°14.
It is preferable to use compounds of 15.1B and 19.20.

Furthermore, charge transport substances known per se can also be used in combination with the above-mentioned styrenic compounds.

Specifically, it is a hole transport material or an electron transport material, and examples of suitable hole transport materials include poly-N-vinylcarbazole, phenanthrene, N-ethylcarbazole, 2.5
-diphenyl-1゜3.4-oxadiazole, 2,5
-bis-(4-diethyleneminophenyl)-1,3゜4-oxadiazole, and su-diethylaminophenyl-1,3,6-oxadiazole, 4゜4'-bis(diethylamino)-2,2' -dimethyltriphenylmethane, 2,4.5-)riaminophenylimidazole, 2,5. -bis(4-diethylaminophenyl)-1
, 3,4-triazole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminophenyl)-2-pyrazoline, p-diethylaminobenzaldehyde-(diphenylhydrazone), etc. Examples of electron transport materials are 2-nitro-9-fluorenone, 2゜7-sinitro-9-fluorenone, 2,4
．． 7-dolinitro 9-fluorenone, 2,4,5゜7
-tetranitro-9-fluorenone, 2-nitrobenzothiophene, 2,4.8-trinidrothioxanthone,
These include dinitroanthracene, dinitroacridine, and dinitroanthraquinone.

In producing the photoreceptor, the layer-forming composition as described above can be formed by coating means such as barcode coating or blade coating, except for the case of vapor deposition. In the case of the first type of photoreceptor, the CGL is 0.05 to 2.
．． 0 μm, CTL is formed with a layer thickness of IO to 25 μm. In the case of the second type of photoreceptor, the photosensitive layer is formed with a layer thickness of 5 to 15 μm.

In implementing the photoreceptor of the present invention, it is preferable to use the first type, that is, a functionally separated photoreceptor consisting of two layers, CGL and CTL, since higher sensitivity can be obtained.

(Example 1) A cyclohexanone solution of metal-free phthalocyanine (weight ratio 2/75) was dispersed for 3 minutes using an ultrasonic disperser. An equal amount of a polyester resin tetrahydrofuran solution (weight ratio 2/75) was added to this dispersion, and ultrasonic dispersion was performed for 2 minutes to prepare a pigment dispersion.

This pigment dispersion was used to form a carrier generation layer (CGL: resin, pigment ratio 1/1) with a thickness of 1.0 μm (dry film thickness) on a conductive aluminum substrate using a bar coater.

Next, among the charge transport materials mentioned above, indoline compound No. 3 was dissolved in benzene at a weight ratio of 7:10 to polycarbonate resin, and carrier transport 1 m (
It was used as a coating liquid for CTL).

This coating liquid was applied onto the CGL using a bar coater so that the film thickness (dry) was 17 μm.

The thus obtained laminated photoreceptor was measured using a commercially available sensitivity measuring instrument E.
P A (electrostsattc paper
An impressive measurement was performed using an analyzer (manufactured by Kawaguchi Electric). In this measurement, first the surface of the photoreceptor was set at -600V.
and then charged to 401. Exposure was performed using a halogen lamp of ux, and the half-reduced exposure amount (Lux・se
c) was taken as the sensitivity.

As a result, the above-mentioned photoreceptor of the present invention has a power of 3.3 Lux.
It was found that it has a high sensitivity of sec.

When a photoreceptor with this layered structure was loaded as a master into a commercially available electrostatic copying machine (DC-111 manufactured by Sanda Kogyo, modified to have a negative charging specification) and a copying test was performed, clear copies with no fog were obtained. Obtained.

Next, a photoreceptor with the same configuration was formed on an aluminum drum with a diameter of 120 m, and loaded into a commercially available electrostatic photocopier (DC-5132 manufactured by Sanda Kogyo, modified to have a negative charging specification). When copies were made at a high speed of 50 copies per minute, clear copies without fog were continuously obtained. As a result, it was revealed that the laminated photoreceptor of the present invention has high sensitivity sufficient to withstand high-speed copying.

(Example 2) Regarding the laminated photoconductor on the master of Example 1, the pigment was changed from a phthalocyanine-based pigment to a disazo pigment (guiampure-based pigment).
1C, r, 21180), and perylene pigments (N, N'
A photoreceptor was prepared in the same manner except that the amount of diimide (dimethylperylene-3,4,9,10-tetracarboxylic acid diimide) was changed.

When the half-life exposure of these two types of laminated photoreceptors was measured using EPA, the following excellent values were obtained.

Disazo pigment 3.5 Lux-sec perylene pigment 4. OLux-sec (Comparative Example) Three types of master-like laminated photoreceptors were prepared in the same manner as in Example 1 and Example 2 except that PVK was used instead of compounds No. 3 as the charge transport material. did.

When the half-life exposure of these three types of laminated photoreceptors was measured using EPA, the following results were obtained.

Phthalocyanine pigment 12 Lux-sec disazo pigment 15 Lux-sec perylene
Pigment 16 Lux-sec From this, it was found that when PVK was used, the sensitivity was lower than when the charge transport material related to the present invention was used.

(Example 3) A coating solution for a single-layer photoreceptor was prepared using the following formulation.

β-type phthalocyanine (manufactured by BASF) 8 parts by weight No. 7
Compound 70 parts by weight Vinyritine chloride
Resin (Saranresin manufactured by Dow Chemical) 100 parts by weight Tetrahydrofuran 1200 parts by weight The above formulation solution was placed in a stainless steel ball mill and dispersed for 24 hours to obtain a uniform coating solution. Next, a photoreceptor was prepared by applying the above coating solution onto an 80 μm thick aluminum plate using a doctor blade so that the thickness was 7 μm (when dry).

When this was done in the same manner as in Example 1 to create a half-decreased exposure amount using EPA (STAT ■ mode), the result was 8.5 Lux-
It was found that it had a high sensitivity of sec.

Next, the above coating liquid was applied to a 78φ aluminum drum to produce a drum-shaped photoreceptor. When this photosensitive drum was loaded into a commercially available copying machine (manufactured by Sanda Kogyo, DC=Ill, but modified to have a negative charging specification) and copies were made at a speed of 11 pages per minute, clear copies with no fog were obtained. .

Claims (7)

[Claims] (1) As a charge transport substance, there are the following general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼ In the formula, Ar_1 and Ar_2 are substituted or unsubstituted phenyl groups, and the substituents are halogen atoms, alkyl groups, alkoxy groups, or An electrophotographic photoreceptor comprising a layer containing an indoline compound using a nitro group, where X is a group having an indoline ring. (2) The photoreceptor according to claim 1, wherein the photosensitive layer is a single-layer photosensitive layer comprising the charge-transporting substance and the charge-generating pigment contained in an electrically insulating binding medium. (3) The charge generating pigment is present in an amount of 5 to 100 parts by weight per 100 parts by weight of the binder, and the charge transport material is also present in an amount of 4 to 100 parts by weight.
The photoreceptor according to claim 2, wherein the photoreceptor is contained in an amount of 0 to 150 parts by weight. (4) The photosensitive layer comprises a charge-generating layer having a charge-generating pigment provided on a conductive substrate, and a charge-transporting layer containing the charge-transporting substance thereon.
Photoreceptor described in section. (5) The charge generation layer binds the charge generation pigment to the binding medium 100.
The photoreceptor according to claim 4, wherein the photoreceptor contains 50 to 300 parts by weight per part by weight. (6) The photoreceptor according to claim 4, wherein the charge generation layer is a vapor-deposited layer of a charge generation pigment. (7) The charge transport layer binds the charge transport material to a binding medium 1.
5. The photoreceptor according to claim 4, wherein the photoconductor contains the photoreceptor in an amount of 40 to 150 parts by weight per 0.00 parts by weight.