JPH0266557A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To make the density of an image uniform and to improve the image quality by specifying the interval between peaks of the waviness, the height of each peak and the difference in height between adjacent peaks or the difference in depth between adjacent valleys in the filtered wave obtained by measuring along the center line of the support. CONSTITUTION:The waviness of the surface of a support is regulated in the filtered wave so that the interval (a) between peaks to <=0.15mm, the height of each peak (b) to <=1.5mum and the difference (c) in height between adjacent peaks to <=0.2mum or the difference (d) in depth between adjacent valleys to <=0.3mum. The difference in height between a standard peak and other peak is regulated to <=0.2mum or the difference in depth between a standard valley and other valley to <=0.3mum. A photoconductive layer is formed on the support by laminating an electric charge generating layer and an electric charge transferring layer. By using the resulting sensitivity body, a high quality image having uniform depth of color can be formed.

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 so far. For example, JP-A-58-16
No. 2975 discloses that the roughness of the surface of the support is 0.05.
By specifying that the voice is ~1μI, also JP-A-60-1
Publication No. 12049 discloses that the surface of the support is roughened, the roughened surface is provided with unevenness in the form of flat grooves, and the distance between the ridges is 20 μm.
Hereinafter, a technique is disclosed in which the adhesion between the support and the photoconductive layer or the intermediate layer is improved by specifying the height of the peak to be 0.3 μm to 2 μm. Japanese Patent Publication No. 60-22585
In Japanese Patent Application No. 46966, the surface roughness of the support surface is A technique has been disclosed for preventing the occurrence of interference fringes by defining the distance between the ridges of the surface irregularities as 0.05-340μ and 0.2μFF1-10. Japanese Unexamined Patent Publication No. 57-
No. 81269 discloses that the maximum surface roughness of the support surface is 0.
．． A technique has been disclosed to prevent deterioration of sensitivity by specifying the average surface roughness as 7 μm or more and 0.5 μm or more.
).

[Problem to be solved by the invention]

However, in the conventional electrophotographic photoreceptor constructed using a support according to the above-mentioned regulations, when an image such as a halftone image is produced, a light unevenness occurs in the same pattern as the surface shape of the support. The disadvantage is that this occurs.

For example, when copying a color original 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 appear randomly on the image. Something happens.

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 the average evaluation of surface roughness, it is impossible to eliminate the randomly occurring 213 light unevenness.

The cause of such random unevenness is that because the charge generation layer in the photoconductive layer provided on the support is formed in a thin layer, the amount of charge generation material is affected by the unevenness of the support surface. It is conceivable that variations may occur. That is,
Sensitivity is high in areas where there is a large amount of charge-generating material, and conversely, sensitivity is low in areas where there is a small amount of charge-generating material, resulting in a difference in sensitivity between the two. Due to this sensitivity difference, a potential difference in a low contrast area appears as uneven development, resulting in a difference in density. It becomes less noticeable in some midtones and high contrast areas. On the other hand, it may be possible to provide an intermediate layer between the support and the charge generation layer with a thickness thick enough to avoid the effects of unevenness on the surface of the support. There are disadvantages such as a large increase in potential.

SUMMARY OF THE INVENTION In view of the above 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, according to the present invention, a light guide layer is provided on a support directly or via an intermediate layer.
In the electrophotographic photoreceptor, the surface shape of the support is undulating, and the distance between the crests of the unevenness obtained from the filter center line undulation curve is 0.15 square or less, and the height of the ridges is 1.5
μm or less, and the height difference between adjacent mountains is 0.2 pm.
Provided is an electrophotographic photoreceptor characterized in that the step difference between two or one adjacent valley is 0.3 μm or less.

The present inventors reviewed the conventional average value evaluation of surface roughness for the surface shape of a support, and as a result of intensive study, the distance and height of each unevenness on the surface of the support were determined. It has been found that controlling the surface shape of the support by regulating it 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 centerline waviness curve whose fine irregularities were removed using a filter. In addition,
"Waviness" as used herein is defined in JIS B 0610.
Surface waviness described in 1. Surface waviness refers to unevenness with a longer interval than 1 surface roughness, but a shorter interval than the irregularity of shape that is considered to be shape accuracy.

In this way, as a result of examining the distance between the peaks and peaks of each unevenness on the support obtained from the filtering centerline waviness curve, and the relationship between the height of the peaks and the uneven density of the image, the filtering centerline waviness curve The distance between the peaks and the peaks of the unevenness of the obtained support is 0.15 mm or less, the height of the peaks is 1.5 tiles or less, and the height difference between the matching peaks is 0.2 μI or less or adjacent valleys. It was found that when the height difference between the two and the valleys was 0.3 μm or less, unevenness did not occur in the image. The height of the ridges is preferably 1.0 μm or less, and the height difference between the ridges is preferably 0.17. +m or less,
It is desirable that the height difference between the valleys be set to 0.2 μm or less. Furthermore, it is preferable that the level difference between the reference peak and other peaks be 0.2 μm or less, or the level difference between the reference valley and other valleys be 0.3 micrometer or less. Further, it is preferable that the cutoff value in the measurement of the waviness curve be 0.08 am. In addition.

The distance between the mountains, the height of the mountains, the height differences between the mountains, and the height differences between the valleys are as shown in Figure 1.

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 single optical layer directly or via an intermediate layer on a support having the above-described surface shape.

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 defined as described above.

As the intermediate layer in the present invention, Sin, A Q 2
0° or other inorganic materials provided by methods such as vapor deposition, sputtering, or anodization, or polyamide resin (Japanese Patent Laid-open No. 58
-30757, Japanese Patent Application Laid-open No. 58-98739)
.

Alcohol-soluble nylon resin (JP-A-60-1967
66), water-soluble polyvinyl butyral resin (Japanese Patent Laid-Open No. 60-232553), polyvinyl butyral resin (Japanese Patent Laid-Open No. 58-106549), polyvinyl alcohol, or the like can be used.

Furthermore, a resin intermediate layer in which pigment particles such as ZnO, TlO2, ZnS, etc. 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 transport 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 the charge generating substance include CI Pigment Blue 25 [Color Index (CI) 21180],
CI Pigment Red 41 (CI 21200),
Sea Eye Acid Red 52 (CI' 45100),
CI Basic Red 3 (C-45210), further a phthalocyanine pigment having a porphyrin skeleton,
Azulenium salt pigments, squalic salt pigments, azo pigments having a carbazole skeleton (described in JP-A No. 53-95033), azo pigments having a stilstilbene skeleton (described in JP-A-53-138229), Azo pigments having a phenylamine skeleton (Japanese Patent Application Laid-Open No. 53-132
547), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728),
Azo pigments having an oxadiazole skeleton
12742), an azo pigment having a fluorenone skeleton (described in JP-A No. 54-22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17)
733), azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-2129),
(described in JP-A No. 54-17734), trisazo pigments having a carbazole skeleton (described in JP-A-57-19576)
No. 7, No. 57-195768), and CI Pigment Blue 16 (CI 7410).
0), C.I. Butt Brown 5 (CI ?3410), C.I. Butt Dye (CI
Organic pigments such as indigo pigments such as 73030) and perylene pigments such as Argo Scarlet B (manufactured by Violet) and Indus Thread Scarlet R (manufactured by Bayer) can be used.

The thickness of the charge generation layer 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, methyl cellosolve, etc. may be used alone or in combination. Can be done.

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.

Examples of the charge transport substance include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives and 2-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 resin, silicone resin, epoxy resin, melamine Examples include thermoplastic or thermosetting resins such as resins, urethane resins, phenol resins, and alkyd resins.

As the solvent at this time, tetrahydrofuran, dioxane, toluene, monochlorobenzene, diglorethane, 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 16, Comparative Examples 1 to 5 An aluminum drum with a diameter of 80 parts was cut under the following processing conditions.

Drum rotation speed: 1000-5000r, p, m.

Bit feed amount: 0.03 to 0.14+m/rotation Bit tip Rl to IOR After cutting, hot melt cleaning was performed with perchlorethylene solvent.

Next, alcohol-soluble polyamide resin (nylon 6/6
6/610/12. East Lz 1KCM-8000) 80
1,300 parts of methanol, and then 600 parts of butanol was added to prevent whitening of the film during film formation. A solution containing 600 parts of butanol was applied onto these aluminum drums by dipping, and 10
It was dried at 0°C for 5 minutes to form a thick (L3-) subbing layer.

On the other hand, 20 parts of a bisazo pigment having the following structural formula and 400 @ 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 with a thickness of 0.2 IJs.

Next, a homogeneous solution of 500 parts of a charge transporting substance having the following structure, 500 parts of polycarbonate resin (C-1400 manufactured by Ondai) and 4000 parts of methylene chloride is prepared, and 5 parts of silicone oil as a leveling agent is added to this solution for coating. This is applied as a liquid onto the charge generation layer by a dipping method, and 12
It was dried at 0°C for 30 minutes to form a charge transport layer with a thickness of 20ρ.

Table 1 The thus obtained electrophotographic photoreceptor was attached to a copying machine having a normal electrophotographic process (charging, exposure, development, transfer), and an image was produced using a half-1-print 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. The distance between the peaks and the height of the peaks were determined from the wave center line undulation curve, and the machine and cutoff value used to measure this undulation curve are as follows.

Measuring machine Tokyo Precision Layer Surface roughness meter Surfcom cutoff (direct fh = 0.08 mm Examples 17 to 22, Comparative Examples 6 to 9) 10 parts of alcohol-soluble copolymerized nylon (CM-8000, manufactured by Toshi Co., Ltd.) in methanol To this were added 1 part of an anionic conductive polymer (Chemistat 6120 manufactured by Sanyo Chemical Co., Ltd.) and 100 parts of unsurface-treated titanium oxide (TA-100 manufactured by Fuji Titanium Industries, Ltd.).

The mixture was dispersed in a ball mill for 8 hours to prepare a coating solution for an undercoat layer.

This solution was applied by dipping onto the surfaces of supports cut under the same processing conditions as Examples 1 to 16 and Comparative Examples 1 to 5, and then dried at 120° C. for 5 minutes. The undercoat layer thus obtained had a thickness of about 3.5 IJs.

Next, 5 parts of polyester resin (manufactured by Toyobo Co., Ltd.) was dissolved in 150 parts of cyclohexanone, 10 parts of trisazo pigment having the following structural formula was added thereto, dispersed in a ball mill for 48 hours, and further 210 parts of cyclohexanone was added. In addition, dispersion was performed for 3 hours. Take this out into a container, and the solid content is 1
．． It was diluted with cyclohexanone while stirring to a concentration of 5% by weight. The charge generation layer coating solution thus obtained was applied onto the undercoat layer by a dipping method, and then dried at 120° C. for 5 minutes to form a charge generation layer with a thickness of about 0.2 μm.

Next, after dissolving 7 parts of a charge transporting substance with the following structural formula and 10 parts of polycarbonate resin (Panlite -1300 manufactured by Yondai Kasei Co., Ltd.) in 85 parts of methylene chloride, silicone oil (Shin-Etsu Chemical Co., Ltd. model KF-50) 0. 003 parts were 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 to form a charge transport layer with a thickness of 20 μm, thereby producing a laminated electrophotographic photoreceptor.

The electrophotographic photoreceptor thus obtained was attached to a copying machine having a normal electrophotographic process (charging, f8 light, 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-2.

Table-2 〔Effect of the invention〕 As described in detail above, according to the present invention.

The distance between the peaks and peaks of the unevenness on the support surface obtained from the filter center line waviness curve is 0, 15 mm or less, and the height of the peaks is 1.5
µm or less, and the difference in level between adjacent peaks is 0.2 µm or less, or the difference in level between adjacent valleys is 0.3 µm or less, so high-quality images without density unevenness can be obtained. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the definition of each parameter that defines the surface shape of the support according to the present invention. Patent applicant Rico Co., Ltd.

Claims (3)

[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 unevenness is obtained from the filter center line undulation curve. The distance between the peaks is 0.15 mm or less, the height of the peaks is 1.5 μm or less, and the height difference between adjacent peaks is 0.2 μm or less, or the height difference between adjacent valleys is 0.3 μm.
A photoreceptor for electrophotography, characterized in that the particle size is less than m. (2) The electrophotographic photosensitive material according to claim 1, wherein the height difference between the reference peak and other peaks is 0.2 μm or less, or the step difference between the reference valley and other valleys is 0.3 μm or less. body. (3) The electrophotographic photoreceptor according to claim 1 or 2, wherein the photoconductive layer is formed by laminating a charge generation layer and a charge transport layer.