JPH0240663A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To form an image which is free from unequal densities and has high quality by specifying the distance between the peaks of the ruggedness obtd. from the undulating curves of the surface shape of a base. CONSTITUTION:A photoconductive layer is provided directly or via an intermediate layer on the base having the surface shape of the undulating curves to constitute the photosensitive body. This base is formed of Al, Al alloy or the like to a cylindrical or film shape. The surface shape thereof is so regulated that the distance between the peaks of the ruggedness obtd. from the undulating curves is <=0.15m/m, the height of the peak is <=1.5mum, or the distance between the peaks is larger than 0.15mm and the height of the peaks is <=0.3mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and particularly to the surface shape of a support.

[Conventional technology]

Generally, this type of electrophotographic photoreceptor is constructed by providing a photoconductive layer on a support made of aluminum, aluminum alloy, etc., either directly or via an intermediate layer, by vapor deposition or the like. Regarding the surface shape of the support, several regulations have been proposed in the past.
Publication No. 2049 specifies that the surface of the support is a rough surface, that this rough surface has flat groove-like unevenness, that the distance between the ridges is 20R or less, and that the height of the ridges is 0.3 and 2 μm. According to
Techniques have been disclosed for improving the adhesion between a support and a photoconductive layer or intermediate layer. Also, JP-A-61-4696
No. 6 discloses that the surface roughness of the support surface is from 0.05 μm to
3.0 μm.

A technique has been disclosed for preventing the occurrence of interference fringes by defining the distance between the ridges of the surface irregularities as 0.2 to 10 μm. Also, in Japanese Patent Publication No. 62-42498.

The maximum surface roughness of the support is 0.7. As described above, techniques have been disclosed for preventing deterioration of sensitivity by setting the average surface roughness to 0.57a or more.

[Problem to be solved by the invention]

However, with conventional electrophotographic photoreceptors constructed using supports based on the above-mentioned regulations, when images such as halftone images are produced, uneven shading occurs in the same pattern as the surface shape of the support. There is a disadvantage that it occurs.

For example, when copying a color document such as a catalog using a copier equipped with an electrophotographic photoreceptor that uses a support with a cut finish, white streaks in the same pattern as the cut surface may randomly appear on the image. occurs.

One problem with this is that the surface shape of the support is controlled using parameters obtained from multiple irregularities (e.g. maximum surface roughness, average surface roughness, etc.), that is, it is controlled based on an average value evaluation. . It is generally known that it is difficult to have uniform irregularities on the surface of a support unless it is mirror-finished. Therefore, if the surface of the support is processed according to regulations based on average value evaluation, it is not possible to eliminate randomly occurring unevenness in density.

SUMMARY OF THE INVENTION In view of one or more points, it is an object of the present invention to provide an electrophotographic photoreceptor that can form images with high quality without unevenness in density.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an electrophotographic photoreceptor in which a photoconductive layer is provided on a support directly or through an intermediate layer, in which the surface shape of the support is undulating. The distance between the peaks and the peaks of the unevenness obtained from the undulation curve is 0.15 mm or less and the height of the peaks is 1.5 μm or less, or the distance between the peaks is more than 0.15 mm and the height of the peaks is 0.3 μm or less. An electrophotographic photoreceptor is provided.

The present inventors reviewed the average value evaluation of the conventional support surface shape and conducted extensive studies.

It has been found that controlling the surface shape of the support by regulating the distance and height between the individual uneven ridges on the surface of the support is important for preventing uneven shading of images. In addition, when regulating the distance and height of the uneven peaks on the support surface, if the regulation is based on the cross-sectional curve or roughness curve, fine unevenness that is unrelated to the unevenness of the image will become a problem. I learned that because the surface is mixed with unevenness, the size of these small unevenness causes problems such as variations in the distance and height of the unevenness.

Therefore, this inconvenience was solved by using a waviness curve in which the rope irregularities were removed using a filter. Note that "undulation" referred to in this specification is defined in JIS B 06.
It refers to the surface waviness described in 10, which means unevenness with a longer interval than the surface roughness, but a shorter interval than the irregularity of the shape, which is considered to be the shape accuracy.

In this way, as a result of investigating the distance between the peaks and peaks of individual unevenness on the support obtained from the waviness curve and the relationship between the height of the peak and the unevenness of the image, the peaks of the unevenness of the support obtained from the waviness curve were investigated. When the distance between and the mountain is less than 0.15mff1, the height of the mountain is 1
．． It has been found that when the distance between the peaks is 5 μm or less, or the distance between the peaks is greater than 0.15+nm and the height of the peaks is 0.3− or less, uneven shading does not occur in the image.

Next, the structure of the electrophotographic photoreceptor of the present invention will be explained in more detail.

The electrophotographic photoreceptor of the present invention is basically constructed by providing a photoconductive layer on a support having the above-described surface shape either directly or via an intermediate layer.

Examples of the support used in the present invention include a cylindrical or film-shaped support made of metal such as aluminum or aluminum alloy. The surface shape is as described above.

The distance between the peaks of unevenness obtained from the undulation curve is 0°15
mm or less and the height of the peaks is 1.5 μm or less, or the distance between the peaks is greater than 0.15 mm and the height of the peaks is 0.3 units or less.

In the present invention, the intermediate /& may be formed by using an inorganic material such as 5iO1AQ, 0° by vapor deposition, sputtering, anodizing, or the like, or a polyamide resin (Japanese Unexamined Patent Publication No. 58-3
No. 0757, JP-A-58-98739], alcohol-soluble nylon resin (JP-A-60-19676)
6), water-soluble polyvinyl butyral resin (JP-A-60-232553), polyvinyl butyral resin (JP-A-58-106549), polyvinyl alcohol, and the like can be used.

Furthermore, a resin intermediate layer in which pigment particles such as ZnO1Ti02 and ZnS are dispersed can also be used as the intermediate layer.

Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, etc. can also be used as the intermediate layer of the present invention.

The photoconductive layer in the present invention may be of a laminated type having a charge generation layer and a charge transporting layer, or may be of a single layer type, but it is preferable to use a laminated type photoconductive layer.

The charge generation layer is formed from a charge generation substance and a resin binder.

Examples of charge-generating substances include CI Pigment Blue 25 [Color Index (CI) 2111110].
), CI Pigment Red 41 (CI 21200
), Sea Eye Acid Red 52 (CI 45100)
, CI Basic Red 3 (CI 45210),
Furthermore, phthalocyanine pigments having a porphyrin skeleton, azulenium salt pigments, squalic salt pigments, and azo pigments having a carbazole skeleton (Japanese Patent Application Laid-Open No. 53-95033
(described in JP-A-53-138229), an azo pigment having a stilstilbene skeleton (described in JP-A-53-138229), an azo pigment having a triphenylamine skeleton (described in JP-A-53-13-13)
2547), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728)
, an azo pigment having an oxadiazole skeleton (Japanese Unexamined Patent Application Publication No. 54
-12742), an azo pigment having a fluorenone skeleton (described in JP-A-54-22834),
Azo pigment having a bisstilbene skeleton (JP-A-54-1
7733), an azo pigment having a distyryloxadiazole skeleton (described in JP-A No. 54-2129), an azo pigment having a distyrylcarbazole skeleton (described in JP-A-54-17734) , a trisazo pigment having a carbazole skeleton (JP-A-57-1957)
Publication No. 67.

57-195768), phthalocyanine pigments such as CI Pigment Blue 16 (CI 74100), CI Bat Brown 5 (CI
73410).

Indigo pigments such as CI Bat Dye (CI 73030), Argo Scarlet B (manufactured by Violet),
Organic pigments such as perylene pigments such as Indus Thread Scarlet R (manufactured by Bayer AG) can be used.

The film thickness for charge generation is suitably about 0.05 to 2 .mu.m, preferably 0.1 to 1 .mu.m.

The charge generation layer can be formed by dissolving or dispersing the binder and charge generation substance described below in a suitable solvent, coating the solution, and drying the solution. As a solvent, benzene, toluene, xylene, methylene chloride, dichloroethane, monochlorobenzene.

Dichlorobenzene, ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexanone, methyl cellosolve, ethyl cellosolve, etc. can be used alone or in combination.

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

As charge transport substances, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate 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.

As the resin binder, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer,
Polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyltoluene, poly-N-vinylcarbazole, acrylic 4i! Examples include thermoplastic or thermosetting resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

As the solvent at this time, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc. can be used.

The thickness of the charge transport layer is suitably about 5 to 100 μm.

Further, the single-layer type photoconductive layer is composed of the charge generating substance, the charge transporting substance, and the binder resin.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 10, Comparative Examples 1 to 5 An aluminum drum with a diameter of 80 mm was cut under the following processing conditions.

Drum rotation speed: 1.000-500Or, P, m.

Tool feed fio, 03-0.14mm/rotation tool tip R1~IOR Next, alcohol-soluble polyamide resin (nylon 6/6
On 6/610/12, 80 parts of Toshi CM-8000) was dissolved in 1300 parts of methanol, and then 600 parts of butanol was added to prevent whitening of the film during film formation.The solution was poured onto these aluminum drums. Apply by dipping method, IO'0℃
This was dried for 5 minutes to form a subbing layer with a thickness of about 0.37n++.

On the other hand, 20 parts of a bisazo pigment having the following structural formula and 400 parts of cyclohexanone were cross-dispersed in a ball mill for 45 hours to obtain a highly viscous cream dispersion.

Next, a mixed solvent consisting of 400 parts of methyl isobutyl ketone and 200 parts of cyclohexanone was added to this dispersion, and after cross-dispersing again for 2 hours, it was further diluted with 1000 parts of methyl isobutyl ketone to prepare a coating solution. It was coated on the undercoat layer by a dipping method and dried at 120° C. for 5 minutes to form a charge generation layer having a thickness Q of 2 μm.

Next, a homogeneous solution of 500 parts of a charge transporting substance having the following structure, 500 parts of polycarbonate resin (Ondai''*C-1400) and 4000 parts of methylene chloride was prepared, and 5 parts of silicone oil was added as a leveling agent to the solution. A working solution is applied onto the charge generation layer by a dipping method, and 1
It was dried at 20° C. for 30 minutes to provide a charge transport layer having a thickness of 201JIII.

Table 1 The electrophotographic photoreceptor thus obtained was attached to a copying machine having a normal electrophotographic process (charging, exposure, development, transfer), and an image was produced using a halftone original.

Thereafter, the correspondence between the unevenness of the support and the presence or absence of white streaks in the image was determined. The results are shown in Table-1. Note that the distance between the peaks and the height of the peaks of the unevenness are determined from the waviness curve, and the machine and cutoff value used to determine the dI of this waviness curve are as follows.

Measuring machine: Surface roughness meter, manufactured by Tokyo Seimitsu Co., Ltd. Circcom cutoff value: fh = 0.08 mm Examples 11 to 15, Comparative Examples 6 to 8 7/l/coil Soluble copolymerized nylon (CM-8000
, manufactured by Toshisha Co., Ltd.) was dissolved in 100 parts of methanol.

To this, 1 part of anionic conductive polymer (Chemistat 6120 manufactured by Kochu Kasei Co., Ltd.) and 100 parts of titanium oxide without surface treatment (TA-100 manufactured by Fuji Chitare Kogyo Co., Ltd.) were added and dispersed in a ball mill for 8 hours. A coating solution for underpants was prepared.

This solution was applied by dipping onto the surface of a support cut under the same processing conditions as in Examples 1-10 and Comparative Examples 1-5, and then dried at 120° C. for 5 minutes. The undercoat layer thus obtained has a thickness of approximately 3.5 mm. Met.

Next, 5 parts of polyester resin (manufactured by Toyobo Co., Ltd.) was dissolved in 150 parts of cyclohexanone, and the solution was diluted with cyclohexanone while stirring so that the solid content of the following structural formula was 1.5% by weight. The charge generation layer coating solution thus obtained was applied onto the undercoat layer by a dipping method, and then
Drying was performed at 0° C. for 5 minutes to form a charge generation layer with a thickness of about 0.2 μm.

Next, 10 parts of a trisazo pigment having the following structural formula was added and dispersed in a ball mill for 48 hours, and further 210 parts of cyclohexanone was added and dispersed for 3 hours. Take this out into a container, dissolve 7 parts of the charge transport substance and 10 parts of polycarbonate resin (Panlite-1300 manufactured by Ondai Kasei Co., Ltd.) in 85 parts of methylene chloride, and then add silicone oil (KF-1300 manufactured by Shin-Etsu Chemical Co., Ltd.) to 85 parts of methylene chloride.
50) 0.003 part was added and stirred to prepare a coating liquid for charge transport. This charge transport coating liquid was applied onto the charge generation layer by a dipping method, and dried at 120°C for 15 minutes.
0. After forming a thick charge transport layer and producing a laminated electrophotographic photoreceptor, the resulting electrophotographic photoreceptor is transferred to a copying machine that has a normal electrophotographic process (charging, exposure, development, transfer). I installed it and created an image using a halftone original. Thereafter, the correspondence between the unevenness of the support and the presence or absence of white streaks in the image was determined. The results are shown in Table-2.

Table 2 Since the height is regulated to 0.3 μI or less, it is possible to form a high-quality image without uneven density.

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor in which a photoconductive layer is provided on a support directly or via an intermediate layer, the surface shape of the support is undulating, and the ridges and ridges of unevenness are obtained from the undulation curve. The height of the mountain is 1 when the distance is less than 0.15 mm.
．． An electrophotographic photoreceptor characterized in that the distance between the peaks is 5 μm or less, or the distance between the peaks is greater than 0.15 mm, and the height of the peaks is 0.3 μm or less.