JPS6355560A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent rise of residual potential and change of sensitivity even during repeated uses by forming an undercoat layer made of a palmed resin containing a compound having a sulfo group. CONSTITUTION:The undercoat layer 12 made of the polyamide resin containing the compound having a sulfo group, such as polyethylenesulfonic acid, polystyrenesulfonic acid, benzensulfonic acid, p-toluenesulfonic acid, naph thalenesulfonic acid, and anthracenesulfonic acid, and the photosensitive layer 15 composed of an electric charge generating layer 13 and a charge transfer layer 14 are formed on a conductive substrate 11, thus permitting the obtained electrophotographic sensitive body to be reduced in rise of residual potential and change of sensitivity.

Description

[Detailed description of the invention] 4th anniversary The present invention relates to an electrophotographic photoreceptor.

Conventionally, a subbing layer containing a polyamide resin has been provided between a charge generation layer containing an azo pigment and a polyvinyl butyral resin and a conductive layer, as seen in JP-A-58-30757. It is publicly known. However, this product had the drawback that the residual potential increased under low temperature and low humidity conditions.

Furthermore, JP-A No. 58-95744 discloses a photoreceptor provided with an undercoat layer containing a polyamide resin and a conductive polymer, but this photoreceptor's sensitivity changes due to fatigue caused by repeated use. There was a drawback.

OBJECTS The present invention overcomes the conventional drawbacks, and aims to provide an electrophotographic photoreceptor that exhibits little increase in residual potential and little change in sensitivity even after repeated use.

Ao - 11 precepts.

The present invention was developed as a result of intensive research to achieve the above object.
An electrophotographic photoreceptor in which a subbing layer mainly composed of a resin is provided between a conductive support and a photosensitive layer, wherein the subbing layer contains a compound having a sulfonic acid group and a polyamide resin. It has been found that the above object can be achieved by providing an electrophotographic photoreceptor characterized by:

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention, in which a subbing layer 12 and a photosensitive layer 1 are provided on a conductive support 11.
5 is provided. The photosensitive layer 15 is the charge generating layer 13. It is composed of a charge transfer layer 14.

The undercoat layer 12 is composed of a compound having a sulfonic acid group and a polyamide resin.

Examples of the compound having a sulfonic acid group include polyethylene sulfonic acid, polystyrene sulfonic acid, benzenesulfonic acid, para-toluene-sulfonic acid, naphthalene sulfonic acid, anthracene sulfonic acid, and the like. Preferred are polystyrene sulfonic acid and para-toluene sulfonic acid.

The polyamide resin is preferably linear polyamide, and so-called nylon and copolymerized nylon are used. Also N-
Methoxymethylated nylons are also used.

It is appropriate to add the compound having a sulfonic acid group in an amount of 1 to 20% by weight based on the polyamide resin, preferably 3% by weight.
~10% by weight.

The thickness of the subbing layer is preferably 0.1 to 5 μm, particularly 0.3 μm.
~2 μm is suitable. If the film thickness becomes too thin, abnormal images will occur due to minute defects, dirt, deposits, scratches, etc. on the surface of the support.

Furthermore, if it becomes too thick, the residual potential will increase and background stains will occur on the copy.

The charge generation layer 13 may be formed only from a charge generation substance, or may be formed by uniformly dispersing the charge generation substance in a binder.

Binders include polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, and polystyrene.

Poly-N-vinylcarbazole, polyacrylamide, etc. are used.

As the charge generation layer, for example, CI Pigment Blue 25 [Color Index (CI) 21180] is used.

CI Pigment Red 41 (CI 21200),
C.I. Acid Red 52 (CI 45100), C.I. Basic Red 3 (CI 45210), phthalocyanine pigments having a porphyrin skeleton, azo pigments having a carbazole skeleton (JP-A-53-9
5033), azo pigments having a distyrylbenzene skeleton (described in JP-A-53-133455), azo pigments having a triphenylamine skeleton (described in JP-A-53-132547), dibenzo Azo pigments having a thiophene skeleton (described in JP-A-54-21728), azo pigments 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) , an azo pigment having a distyryloxadiazole skeleton (JP-A-54-212
(described in Publication No. 9).

Azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-17734), phthalocyanine pigments such as C.I. Pigment Blue 16 (CI 74100), and C.I. Bat Brown 5 (CI
73410), C I Bat Die (c F3030)
), and perylene pigments such as Argo Scarlet B (manufactured by Violet) and Indance Scarlet R (manufactured by Bayer). These charge generating substances may be used alone or in combination of two or more.

The binder resin is suitably used in an amount of 5 to 100 parts by weight, preferably 1 to 100 parts by weight, based on 100 parts by weight of the charge generating substance.
It is 0 to 50 parts by weight.

The charge generation layer contains a charge generation substance alone or a charge generation substance and a binder, such as tetrahydrofuran, cyclohexane,
It can be formed by dispersing in a ball mill, attritor, sand mill, etc. using a solvent such as dioxane or dichloroethane, diluting the dispersion liquid appropriately, and applying the dispersion.

The thickness of the charge generation layer 13 is suitably about 0.1 to 1 μm.

The charge transfer layer 14 can be formed by dissolving or dispersing a charge transfer substance and a binder in a suitable solvent, coating the solution on the charge generation layer 13, and drying the solution. Moreover, a plasticizer, a leveling agent, etc. can also be added if necessary.

Charge transfer substances include poly-N-vinylcarbazole and its derivatives, poly-twocarbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives. , imidazole derivatives, triphenylamine derivatives, 9-(p-diethylaminostyryl)anthracene, 1,1-bis-(4-dibenzylaminophenyl)propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene Examples include electron-donating substances such as derivatives.

Binders include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride. , polyarylate resin,
Phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyltoluene, poly-N-
vinyl carbazole, acrylic resin, silicone resin,
Epoxy resin, melamine resin, urethane resin, phenolic resin.

Examples include thermoplastic or thermosetting resins such as alkyred resins. As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc. are used.

The appropriate thickness of the charge transfer layer 14 is about 5 to 30 μI.

The conductive support 11 may be a plastic film on which aluminum, nickel, chromium, nichrome, copper, tin oxide, indium oxide, or the like is vapor-deposited, a plate made of aluminum, nickel, stainless steel, or the like; ．．
1.1. , extrusion.

It is possible to use pipes that have been made into blank pipes using methods such as drawing, and then surface-treated by cutting, superfinishing, polishing, etc.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to the following examples, but it should be understood that the present invention is not limited thereto.

Example 1 The following composition was applied to a 0.2 mm thick aluminum plate (JIS1070 manufactured by Sumitomo Light Metals), copolymerized nylon CM 8000 (East) 6.4
A coating solution for an undercoat layer consisting of 51.5 g of methanol, 22.1 g of butanol, and 1.4 g of a 30% aqueous solution (Rbo N5C) was applied by dip coating so that the film thickness after drying was 1 μm.

On the other hand, take a mixture consisting of 19 g of cyclohexanone with the following composition into a ball mill pot, and use it as a mill member.
After ball milling for 48 hours using a φSUS ball, 20 g of cyclohexanone was further added and milling was carried out for 1 hour.

After milling, remove the mill base and make sure the solid content is 1.
A dispersion liquid for forming a charge generation layer was prepared by adding microhexanone to the mixture and diluting it to a weight %, and stirring the mixture.

This charge generation layer forming liquid was dip coated onto the undercoat layer to form a charge generation layer having a thickness of 0.2 μm after drying. continue,
A charge transfer layer forming solution having the following composition and 9 g of a hydrazone compound having the following structural formula and 75 g of methylene chloride was prepared, and applied by dip coating onto the charge generation layer to form a charge transfer layer with a thickness of about 22 μm after drying. An electrophotographic photoreceptor consisting of a support, a subbing layer, a charge generation layer, and a charge transfer layer was prepared.

Example 2 In the undercoat layer coating solution of Example 1, polystyrene
/phonic acid (VER3A-TL & 72g Spun N5C) Using para-toluenesulfonic acid (Kanto Kagaku Seiya) instead of the above, a subbing layer with a film thickness of 1 μm was prepared.

Further, a charge generation layer forming liquid having the following composition and 50 g of the charge generation layer forming liquid of [Example 1] was applied by dip coating onto the undercoat layer to form a charge generation layer having a thickness of 0.15 μm after drying. Ta.

Subsequently, the following composition, 1.1-bis(4-dibenzylaminophenyl)propane 9g (in F2O
, Shin-Etsu Chemical > Prepare a charge transfer layer forming solution consisting of 76 g of 0.002 g methylene chloride, dip coat it onto the charge generation layer to form a charge transfer layer with a thickness of about 22 μm after drying, and apply the charge transfer layer to the conductive support. An electrophotographic photoreceptor consisting of an undercoat layer, a charge generation layer, and a charge transfer layer was prepared.

Comparative Example 1 Same as Example 1 except that sodium polystyrene sulfonate (Chemistat 6120, Sanyo Chemical) was used instead of polystyrene sulfonic acid (VER5A-TL & 72M N5C) (7) in the undercoat layer coating solution of Example 1. Electrophotographic photoreceptors were produced using exactly the same materials and conditions.

Comparative Example 2 An electrophotographic photoreceptor was prepared using the same materials and conditions as in Example 1, except that polystyrene sulfonic acid (VER3A-TL Na12M, Spun NSC) was removed from the undercoat layer coating solution in Example 1.

The four types of electrophotographic photoreceptors prepared as described above were placed in an electrostatic copying paper test bag @ (SP 428 type, Kawaguchi Electric Seisakusho)
The electrophotographic properties were evaluated using the following conditions (measured in dynamic mode).

First, -6 KV corona discharge was performed for 20 seconds to charge the photoreceptor. Surface potential V2 after 2 seconds and 20 seconds after charging
(V), V+a (V) was measured, and the surface potential V, (V) was further measured after being left in the dark for 20 seconds, and then 4, 5
Lux tungsten light is irradiated, and the exposure amount is E, where vo is attenuated to 1/1O. (Lux-s, ec) and surface potential V, 30 seconds after irradiation. (V) was measured and used as an initial characteristic.

Furthermore, the photoreceptor sample was transferred to a dedicated fatigue tester, and -6
KV corona discharge and 50 Lux light irradiation 40 times/min.
Immediately after repeating about 5000 times, the photoreceptor sample was transferred to the electrostatic copying paper tester described above, and V z HV m gV,, E□, under the same conditions as when the initial characteristics were measured. ,■
,. was measured and used as fatigue characteristics.

The measurement results are shown in Table-1.

Table-1 Table-1 shows that the electrophotographic photoreceptor of the present invention exhibits excellent electrophotographic properties and shows little change in properties due to fatigue.On the other hand, the electrophotographic photoreceptors of Comparative Examples 1 and 2 have residual properties due to fatigue. Potential V. The increase in sensitivity is large, and the sensitivity E is also large. The change is large.

Effects As mentioned above, by forming an undercoat layer in which a compound having a sulfonic acid group is added to a polyamide resin,
It is possible to realize an electrophotographic photoreceptor with little increase in residual potential or change in sensitivity even after repeated use.

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram of the electrophotographic photoreceptor of the present invention. 11... Conductive support 12... Undercoat layer 13.
...Charge generation layer 14...Charge transfer layer 15...
・Photosensitive layer

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor in which a subbing layer mainly composed of a resin is provided between a conductive support and a photosensitive layer, the subbing layer contains a compound having a sulfonic acid group and a polyamide resin. An electrophotographic photoreceptor featuring: