JPH0823700B2 - Electrophotographic photoreceptor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrophotographic photosensitive member, and more particularly to a photosensitive member having an excellent electrophotographic sensitivity by containing a specific charge transporting substance.

(Prior Art) Conventionally, as a charge transport material of a photoreceptor (hereinafter sometimes referred to as OPC) mainly containing an organic pigment, poly-N-vinylcarbazole, 2,5-bis (4-diethylaminophenyl) -1,1, Various electron-transporting substances or hole-transporting substances such as 3,4-oxadiazole and 2,4,7-trinitrofluorenone are known.

(Technical Problem to be Solved by the Invention) Although the charge-transporting substance described above has a sensitizing effect depending on the photoconductive material to be combined, it cannot be said to be sufficient in consideration of a more practical photoreceptor design. It was a thing.

(Means for Solving the Problem) In the present invention, a specific styrene compound represented by the following general formula is used as a charge transport material used in OPC. That is, as a charge transport material, the following general formula In the formula, X is a phenyl group-substituted amino group, Y is a hydrogen atom, a halogen atom or a substituted (halogen atom, alkyl group, alkoxy group or nitro group) or an unsubstituted phenyl group, and Ar1 and Ar2 are substituted (halogen). Atom, an alkyl group, an alkoxy group or a nitro group) or an unsubstituted phenyl group.

(Function) By using the above-mentioned styrene compound as the charge transporting material, a remarkable sensitizing effect can be obtained as compared with the conventional photoconductors using the charge transporting material such as poly-N-vinylcarbazole. can get. The fact of this effect will be described in detail in Examples below, but the sensitivity is summarized in the following table for one compound.

From Table 1 above, it is clear that the styrene compound of the present invention exhibits a particularly excellent action as a charge transport material.

(Effects of the Invention) In the present invention, the use of the above-mentioned specific styrene compound as the charge transport material makes it possible to remarkably increase the sensitivity of the photoreceptor.

Therefore, when the photoconductor containing the charge-transporting substance is used in an electrophotographic copying machine, a laser printer or the like, the sensitivity is high and a clear copy without fog can be obtained.

Further, the photoconductor can be manufactured at a low cost as compared with the case of using Se or a-Si, and the copying speed can be made higher than that of the photoconductor having the same cost.

(Embodiment) The photoconductor in 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 specific styrene compound is used as the charge transporting substance. Any of a type in which a resin layer (CTL) is provided or a composition in which a charge generating pigment is dispersed in the above charge transport medium is provided on a conductive substrate can be used.

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

In the case of the above-mentioned first type photoreceptor, that is, a function-separated type multilayer photoreceptor, a phthalocyanine pigment, a perylene pigment, a disazo pigment, a trisazo pigment, on a conductive substrate,
A charge generating pigment such as a quinacridone pigment is provided as a vapor deposition layer or a resin pigment dispersion layer, and the charge transporting layer containing the above-mentioned styrene compound is provided thereon to form the layer. In this case, the styrene compound is used in an amount ratio of 40 to 150, preferably 70 to 100 parts by weight, based on 100 parts by weight of the resin. When it is more than the above range, it is not preferable in terms of light fatigue and ozone resistance, and when it is less than the above range, sufficient sensitization is not observed.

In the second type of the above-mentioned photoreceptor, that is, the type in which the charge generation pigment is dispersed in the charge transport medium, the charge generation pigment is preferably 5 to 300 per 100 parts by weight of the binder resin.
70 to 150 parts by weight of a styrene compound is used by dispersing or compatibilizing it in an amount ratio of 40 to 150, preferably 70 to 100 parts by weight.

The styrene compound used in the present invention is represented by the above-mentioned general formula, for example, Among these, the compounds of Nos. 1, 2, and 3 are particularly preferable.

Furthermore, a charge transporting material known per se can be used in combination with the styrene compound. Specifically, it is a hole-transporting substance or an electron-transporting substance. Examples of suitable hole-transporting substances are poly-N-vinylcarbazole, phenanthrene, N-ethylcarbazole, 2,5-diphenyl-1,
3,4-oxadiazole, 2,5-bis- (4-diethyleneaminophenyl) -1,3,4-oxadiazole, bis-
Diethylaminophenyl-1,3,6-oxadiazole,
4,4'-bis (diethylamino) -2,2'-dimethyltriphenylmethane, 2,4,5-triaminophenylimidazole, 2,5, -bis (4-diethylaminophenyl) -1,
3,4-triazole, 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) -2-pyrazoline, p-diethylaminobenzaldehyde- (diphenylhydrazone) and the like, and also suitable Examples of such electron-transporting substances are 2-nitro-9-fluorenone, 2,7-dinitro-9-fluorenone, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9.
-Fluorenone, 2-nitrobenzothiophene, 2,4,8
-Trinitrothioxanthone, dinitroanthracene,
Examples include dinitroacridine and dinitroanthraquinone.

In the production of the photoreceptor, the layer forming composition as described above can be formed by a coating means such as a bar code or a blade coat except in the case of vapor deposition. First
In case of the type of photoconductor, CGL is 0.05 to 2.0μ
m and CTL are formed with a layer thickness of 10 to 25 μm. In the case of the second type photoreceptor, the photosensitive layer is formed with a layer thickness of 5 to 15 μm.

In carrying out the photoreceptor of the present invention, the first
It is preferable to use a photosensitive member of the type (i.e., a function-separated type) composed of two layers of CGL and CTL in order to obtain a higher sensitivity.

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

A carrier generation layer (CGL: resin, pigment ratio 1/1) having a thickness of 1.0 μm (film thickness when dried) was formed from this pigment dispersion on a conductive aluminum substrate using a bar coater.

Next, among the charge transport substances described above, the styrene compound of No. 3 was dissolved in benzene in a weight ratio of 7:10 with the polycarbonate resin to prepare a carrier transport layer (CTL) coating liquid.

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

In this way, the obtained laminated photoreceptor is commercialized with a sensitivity measuring device EP.
Sensitivity was measured using A (electrostsatic paper analyzer: Kawaguchi Denki). This measurement was performed by first charging the surface of the photoconductor to -600V and then exposing it with a 40Lux halogen lamp.
c) was defined as the sensitivity.

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

When a photoconductor with this layer structure was used as a master and loaded into a commercially available electrostatic copier (DC-111 manufactured by Mita Kogyo Co., Ltd., which was modified to have a negative charging specification) and a copy test was performed, a clear copy without fog was found. Was obtained.

Next, a photoconductor of the same structure was formed on an aluminum drum with a diameter of 120 mm, loaded into a commercially available electrophotographic copying machine (Mita Kogyo DC-513Z, but modified to a negative charging specification), and every minute. When 50 sheets were copied at a high speed, clear copies without fog were continuously obtained. As a result, it became clear that the laminated photoreceptor of the present invention has high sensitivity enough to withstand high speed copying.

(Example 2) With respect to the master-like laminated photoreceptor of Example 1, the pigments were selected from phthalocyanine-based pigments such as disazo pigments (Diane Blue, CI21180) and perylene pigments (N, N'-dimethylperylene-3,4,9). A photoconductor was prepared in the same manner except that it was changed to (10,10-tetracarboxylic acid diimide).

The half-exposure amount of these two types of laminated photoreceptors was measured using EPA, and the following excellent values were obtained. Disazo pigment 3.5 Lux · sec Perylene pigment 4.0 Lux · sec (Comparative Example 1) Example 1 And the master-like photoreceptor of Example 2,
Three kinds of master-like laminated photoreceptors were prepared in the same manner except that PVK was used as the charge transport material instead of the compound of No. 3.

The half-exposure amount of these three types of laminated photoreceptors was measured using EPA, and 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 the sensitivity was lower when PVK was used than when the charge transport material according to the present invention was used. .

(Comparative Example 2) A coating solution for a single-layer photoreceptor was prepared according to the following formulation.

8 parts by weight of β-type phthalocyanine (manufactured by BASF) A compound in which X is a 5-ethyl substituted N-ethylindole group, Y is a hydrogen atom, and Ar1 and Ar2 are both unsubstituted phenyl groups. Parts by weight Hydriden chloride resin (Saran resin made by Dow Chemical) 10
0 parts by weight Tetrahydrofuran 1200 parts by weight The above prescription liquid was put into a stainless steel ball mill and dispersed for 24 hours to obtain a uniform coating liquid. Next, an 80 μm thick aluminum plate was coated with the above coating solution to a thickness of 7 μm (when dried) to prepare a photoreceptor using a doctor blade.

When the half-exposure amount was created by EPA (STATII mode) in the same manner as in Example 1, it was found that the sensitivity was high at 8.3 Lux · sec.

Next, the above coating liquid was applied to a 78φ aluminum drum to prepare a drum-shaped photoreceptor. When this photosensitive drum was loaded into a commercially available copying machine (DC-111 manufactured by Mita Kogyo Co., Ltd .: modified to have a negative charging specification) and copied at a speed of 11 / min, a clear copy without fog was obtained. .

(Example 3) Regarding the single-layer photoconductor of Comparative Example 2, in the general formula of the claims, X is a 5-ethyl-substituted N ethylindole group, Y is a hydrogen atom, and Ar1 and Ar2 are both unsubstituted phenyl groups. A photoconductor was prepared in the same manner except that the compound No. 3 was used instead of the compound No. 3. This is carried out in the same manner as in Example 1, and EPA (STATI
Half-exposure measured in I mode) is 3.6 Lux · secx
Met.

(Example 4) With respect to the single-layer photoreceptor of Example 3, from 8 parts by weight of β-type phthalocyanine (manufactured by BASF), a disazo pigment (Diane Blue, CI21180) and a perylene pigment (N, N'-dimethylperylene-) were prepared. A photoconductor was prepared in the same manner except that it was changed to 3,4,9,10-tetracarboxylic acid diimide).

The half-valued exposure amounts of these two types of single-layer photoconductors were measured by the same method as in Example 1, and the following values were obtained.

Disazo pigment 3.9Lux · sec Perylene pigment 4.7Lux · sec (Comparative example 3) Regarding the single-layer photoreceptor of Comparative example 2, from 8 parts by weight of β-type phthalocyanine (manufactured by BASF), a disazo pigment (Dian blue, CI21180), And a photoreceptor was prepared in the same manner except that the perylene pigment (N, N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide) was used.

The half-valued exposure amounts of these two types of single-layer photoconductors were measured by the same method as in Example 1, and the following values were obtained.

Disazo Pigment 7.9Lux · sec Perylene Pigment 8.9Lux · sec (Comparative Example 4) Regarding the master-like laminated photoreceptor of Example 1, the charge transporting material is the styrene compound of No. 3 and Comparative Example 2 is claimed. A photoconductor was prepared in the same manner as above, except that in the general formula of the above formula, X was changed to a 5-ethyl-substituted N-ethylindole group, Y was a hydrogen atom, and Ar1 and Ar2 were both unsubstituted phenyl groups. The half-exposure amount was measured in the same manner as in Example 1 and found to be 6.5 Lux · sec.

Also, except that the pigment is changed from a phthalocyanine-based pigment to a disazo pigment (Diane Blue, CI21180), and a perylene pigment (N, N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide), all in the same manner. A photoconductor was created.

When the half exposure amount of these two types of laminated photoreceptors was measured by the same method as in Example 1, the following values were obtained.

Disazo Pigment 6.7Lux · sec Perylene Pigment 7.3Lux · sec (Comparative Example 5) Regarding the single-layer photoreceptor of Comparative Example 2, in the general formula of Claims, X is a 5-ethyl substituted N-ethylindole group, and Y is hydrogen. Atoms, Ar1 and Ar2 are both phenyl groups which are not substituted, and in the general formula of the claims, X is a carbazole group substituted at the 9-position, Y is a hydrogen atom, and Ar1 and Ar2 are both unsubstituted. A photoconductor was prepared in the same manner except that a compound having a phenyl group was used. When the half-exposure amount was measured in the same manner as in Example 1, it was 8.7 Lux · sec.

Also, except that the pigment is changed from a phthalocyanine-based pigment to a disazo pigment (Diane Blue, CI21180), and a perylene pigment (N, N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide), all in the same manner. A photoconductor was created.

The half-valued exposure amounts of these two types of single-layer photoconductors were measured by the same method as in Example 1, and the following values were obtained.

Disazo Pigment 9.2Lux · sec Perylene Pigment 9.7Lux · sec (Comparative Example 6) Regarding the master-like laminated photoreceptor of Example 1, the charge transporting material was changed to the styrene compound of No. 3 and used in Comparative Example 5. A photoconductor was prepared in the same manner except that X in the general formula in the claims was a carbazole group substituted at the 9-position, Y was a hydrogen atom, and Ar1 and Ar2 were both unsubstituted phenyl groups. The half-exposure amount was measured in the same manner as in Example 1 and found to be 8.0 Lux · sec.

Also, except that the pigment is changed from a phthalocyanine-based pigment to a disazo pigment (Diane Blue, CI21180), and a perylene pigment (N, N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide), all in the same manner. A photoconductor was created.

When the half exposure amount of these two types of laminated photoreceptors was measured by the same method as in Example 1, the following values were obtained.

Disazo pigment 8.4Lux ・ sec Perylene pigment 8.5Lux ・ sec

Claims (7)

[Claims] 1. A charge transporting substance represented by the following general formula: In the formula, X is a phenyl group-substituted amino group, Y is a hydrogen atom, a halogen atom or a substituted (halogen atom, alkyl group, alkoxy group or nitro group) or an unsubstituted phenyl group, and Ar1 and Ar2 are substituted (halogen). Atom, an alkyl group, an alkoxy group or a nitro group) or an unsubstituted phenyl group. 2. The photoconductor according to claim 1, wherein the photosensitive layer is a single-layer photosensitive layer comprising a charge generating pigment and an electric insulating material in an electrically insulating binding medium. 3. The charge generating pigment is used in an amount ratio of 5 to 100 parts by weight per 100 parts by weight of the binder, and the charge transport material is 4 parts by weight.
The photoconductor according to claim 2, wherein the photoconductor is contained in an amount ratio of 0 to 150 parts by weight. 4. The photosensitive layer comprises a charge generating layer having a charge generating material provided on a conductive substrate, and a charge transporting layer containing the charge transporting material thereon. The photoreceptor according to item 1. 5. The charge generation layer comprises a charge generation pigment as a binding medium.
5. The photoconductor according to claim 4, which is contained in an amount ratio of 50 to 300 parts by weight per 100 parts by weight. 6. The photoreceptor according to claim 4, wherein the charge generation layer is a vapor deposition layer of a charge generation pigment. 7. The photoreceptor according to claim 4, wherein the charge transport layer contains the charge transport material in an amount ratio of 100 parts by weight to 40 parts by weight to 100 parts by weight of a binding medium.