JPS6113250A - Manufacture of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body unnecessary for maintenance and prevented from interference by irradiating the surface of an electrostatic charge generating layer with laser beams to the wavelength region of which this layer has sensitivity to form fine roughness, and laminating a charge transfer layer thereon. CONSTITUTION:An intermediate layer 2, when needed, is formed on a conductive substrate 1, and on this layer 2 the charge generating layer 3 and the charge transfer layer 4 are laminated to form an electrophotographic sensitive body for use in a laser beam printer. The conductive substrate is prepared by forming, when needed, a coating layer 5 contg. a phenol resin or the like and a conductive pigment or the like dispersed into said resin on a base 6 made of aluminum or the like. The intermediate layer 2 is, preferably, made of a polyamide resin or the like with a film thickness of 0.2-10mum, and the charge generating layer 3 is formed by dispersing a pigment or dye into a binder resin. The charge transfer layer 4 is made of a hole transfer material, such as a compd. contg. N-contg. cyclic compd. or hydrazone compd. by dissolving it in a film- forming resin soln.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing an electrophotographic photoreceptor, and particularly to a method for manufacturing an electrophotographic photoreceptor for a laser beam printer.

Conventional technology Conventionally, selenium and selenium-based alloys have been used as photoreceptors for electrophotographic printing using a laser as a light source.

Cadmium sulfide resin dispersions, charge transfer complexes of polyvinylcarbazole and trinitrofluoreno/etc., and the like have been used. Gas lasers such as helium-cadmium, argon, and helium-neon have been used as lasers, but recently they have been made smaller.

Semiconductor lasers, which can be directly modulated at low cost, have come into use. However, semiconductor lasers have an emission wavelength of 7
Many of the photoreceptors have a diameter of 50 nm or more.
It had low photosensitivity in that wavelength range, making it difficult to use. For this reason, a laminated type photoreceptor including a charge generation layer and a charge transport layer, which can relatively freely select the photosensitive wavelength range, has been attracting attention as a photoreceptor for semiconductor laser printers.

The charge generation layer of the laminated photoreceptor has the role of absorbing light and generating free charges, and its thickness is as thin as 0.1 to 5μ in order to shorten the range of the generated photocarriers. is customary. This means that most of the incident light is absorbed by the charge generation layer and many photocarriers are generated.
Furthermore, this is due to the need to inject the generated photocarriers into the charge transport layer without being deactivated by recombination or capture. The charge transport layer has the role of accepting static charges and transporting free charges, and is made of a material that hardly absorbs image forming light, and its thickness is usually 5 to 60 microns. When using such a laminated photoreceptor and producing an image by scanning a line of laser light with a laser printer, there is no problem with line images such as characters, but with solid images, density unevenness in the form of interference fringes occurs. appeared. The reason for this is that, as the charge generation layer is formed as a thin layer as mentioned above, the amount of light absorbed by this layer is limited, and as a result, the light that has passed through the charge generation layer is reflected on the substrate surface, and this reflection This is thought to be due to interference between light and reflected light on the surface of the photoconductive layer. The laminated electrophotographic photoreceptor has a charge generation layer 6 and a charge transport layer 4 on a metal conductive substrate 1, as shown in Figures 3 and 4.
It has a laminated structure. Laser light 10 (oscillation wavelength is approximately 780 for semiconductor laser) is applied to this laminated photoreceptor.
nm, approximately 650 nm with helium-neo/laser
) is incident, the reflected light 11 on the surface of the charge transport layer 40 with a large reflection and the incident light 12 that has penetrated into the charge transport layer 4 are reflected on the surface of the metal conductive substrate 1 and exit from the surface of the charge transport layer 40. Interference with the incoming reflected light 16 occurs. The refractive index of the laminated layer of the charge generation layer 5 and the charge transport layer 4 is n, the thickness is d,
Letting λ be the wavelength of the laser beam, when ncl is an integral multiple of λ/2, the intensity of the reflected light is maximum, that is, the intensity of the light entering the charge transport layer 4 is minimum (according to the law of conservation of energy). When nd is an odd multiple of λ/4, the reflected light is minimal, that is, the light entering the interior is maximal. By the way, (IK) cannot avoid thickness unevenness of 0.2μ or more due to manufacturing. On the other hand, since laser light has good monochromaticity and is coherent, the above-mentioned interference condition changes in response to the thickness unevenness of d, and the charge It is thought that unevenness occurs in the amount of laser light absorbed in the generation layer 6, and this appears as interference fringe-like unevenness in the density of the solid painter.In addition, in ordinary copying machines, the light source is not monochromatic light, so the wavelength 1 of interference fringes by
The width of the llli unevenness changes, becomes averaged, and becomes invisible.

Therefore, in order to eliminate such drawbacks, there are methods to prevent interference by adding unevenness to the conductive substrate to scatter reflected laser light, and methods to prevent interference by providing a light absorption layer on the conductive substrate. has been proposed.

However, these methods have drawbacks such as the need for an extra step in manufacturing the photoreceptor and the need to precisely control the unevenness of the conductive substrate.Problems to be Solved by the Invention An object of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor that does not require the above-mentioned extra steps and controls and prevents interference.

Means and Effects for Solving Problems The present invention provides a function-separated electrophotographic photoreceptor having a charge generation layer and a charge transport layer, in which a laser beam within a range to which the charge generation layer is sensitive is applied to the surface of the charge generation layer. The present invention is comprised of a method for manufacturing an electrophotographic photoreceptor, which is characterized by forming minute recesses by irradiating light, and then laminating a charge transport layer.

The feature of the present invention is to irradiate the charge generation layer of the functional 111M photoreceptor with a focused pulsed laser to generate
The depth of 5.0μ is a minute recess (less than the thickness of the charge generation layer).
By forming pits or lines, reflected laser light is scattered and interference is prevented.
1) The formation of pits or lines on the charge generation layer according to the present invention can be carried out continuously without changing the two-layer structure in manufacturing the photoreceptor, and the size of the pits or lines, The depth and density can be easily and precisely controlled by the original intensity of the irradiating pulse laser, the pulse width, or the rotation speed of the drum.
figure).

As the laser used for forming the recesses on the charge generation layer of the present invention, a laser having an oscillation wavelength within the wavelength range to which the charge generation layer is sensitive is suitable, and the laser beam is controlled by an optical system to have a spot size of 0. It is focused to about 5μ to 5.0μ and irradiated onto the charge generation layer. The portion of the charge generation layer that is irradiated with the laser beam absorbs the laser beam and generates heat, so that a small recess is formed at that portion due to thermal deformation. For this purpose, the charge generation layer must be heated to
It is necessary to have sufficient heat resistance as well as suitable for storage.

The present invention will be explained below with reference to the drawings.

Figure 1 is a sectional view of an electrophotographic sensitive element for a laser beam printer of the present invention. An intermediate layer 2 is provided on the conductive substrate 1 as required, and a charge generation layer 3 is provided thereon. A charge transport layer 4 is laminated.

The conductive substrate 1 is formed by dispersing conductive pigments, zinc oxide, tin oxide, titanium oxide, etc. in phenol resin, epoxy resin, silicone resin, acrylic-melamine resin, etc. on a substrate 6 made of aluminum or the like, if necessary. Containing coating layer 5
can be provided. The intermediate layer is made of polyamide resin, casein, polyvinyl alcohol, phenol resin, etc., and has a suitable thickness of about 0.2 .mu.m to 10.0 .mu.m. The charge generation layer 3 is made of azo pigments such as Sudan Red, Diane Blue, and Jenas Green B, and Algol Yellow.

Quinone pigments such as pyrenequinone, indanthrene fluorine (Iolet RRP), quinocyanine pigments, berylev pigments, indigo pigments such as indigo and thioindigo, bisbenzimidazole pigments such as India First Orange Toner, phthalocyanine pigments such as copper phthalo 7ani7, It is formed by dispersing a charge-generating substance such as a quinacridone pigment in a binder resin such as polyester, polystyrene, polyvinyl butyral, polyvinylpyrrolidone, methyl cellulose, polyacrylic acid esters, or cellulose ester.

Its thickness is 0.05μ to 5.0μ, preferably 0.5μ
It is about μ to 2.0 μ. As mentioned above, the charge generating layer according to the present invention requires appropriate thermal deformability and sufficient heat resistance, so the glass transition temperature of the resin used as the binder is an important factor, and preferably 50°C to 100°C. Needs to be controlled within range.

The charge transport layer 4 has a/trace/, bire/, on the main chain or side chain.
Compounds containing polycyclic aromatic compounds such as phenanthrene and coronene, or nitrogen-containing cyclic compounds such as indole, carbazole, oxazole, inogisazole, thiazole, imidazole, pyrazole, bosadiazole, pyrazoline, thiadiazole, and triazole, hydrazone compounds, etc. It is formed by dissolving a hole-transporting substance in a film-forming resin. This is because the charge transporting substance generally has a low molecular weight and has poor film-forming properties by itself. Such resins include polycarbonate, polymethacrylic acid esters, polyarylate, polystyrene,
Examples include polyester, polysulfone, styrene/-acrylonitrified copolymer, styrene/-methyl methacrylate copolymer, and the like. The thickness of the charge transport layer 4 is 5 to 20μ
It is.

Examples are shown below.

Example 1 90 parts by weight of rutile titanium oxide was mixed with 8 parts by weight of acrylic resin (trade name Niacridic A405: manufactured by Dainippon Ink Co., Ltd.)
0 parts (solid content 50%), melamine resin (trade name: Varnish-Perbeckamine L121; manufactured by Dainippon Ink Co., Ltd.) 20 parts (solid content 60 parts) and 100 parts of toluene. Dispersed for 6 hours.

This dispersion was applied onto an aluminum cylinder (substrate 6) measuring 60φ×2605m and dried and cured at 150° C. for 30 minutes to form a coating layer 5 with a thickness of 20 μm.

Next, copolymerized nylon resin (product name: Amino CM80
00, Toshishiku Co., Ltd. Central) was dissolved in a mixed solution of 60 parts of methanol and 40 parts of butano/I/I to form a 1 μ thick polyamide layer. A resin layer (intermediate layer 2) was formed.

Next, ε-type copper-phthalocyanine (trade name: Liophoton,
100 parts of Toyo Ink Manufacturing Co., Ltd.) and polyvinyl butyral resin (trade name
) and 400 parts of cyclohexanor were dispersed for 20 hours in a sand mill using 1φ glass beads. To this dispersion was added 600 parts of methyl ethyl, which was dip coated onto the polyamide resin layer and dried by heating at 50° C. for 10 minutes to form a charge generating layer 6 having a thickness of 5 μm.

Next, as shown in Figure 2, the drum 9 provided with this charge generation layer is mounted on a rotating shaft and rotated at 1000 rpm while being moved in the axial direction at a speed of 10 mvi/min to create a spot on the drum surface. A gallium-aluminum semiconductor laser 7 (oscillation wavelength 780 nm) with an output power of 5 mW and a pulse width of 81 mz focused to a size of 1.0 μ
nm) was scanned onto the charge generation layer through the optical system 8. When this charge generation layer was observed using an SRM, clear bits were observed.

Next, 10 parts of a hydrazone compound having the following structural formula and 15 parts of a styrene-methacrylic methyl copolymer resin (trade name: M8200, manufactured by Tetsusei Kagaku Co., Ltd.) were dissolved in 80 parts of toluene. This liquid was applied onto the charge generation layer 6 and dried with hot air at 100° C. for 1 hour to form a charge transport layer 4 with a thickness of 16 μm.

This laminated photosensitive drum was equipped with a gallium-aluminum-aluminum semiconductor laser (emission wavelength: 780 nm).

Images were produced using an experimental laser printer (charged with negative polarity) having an output of 5 mW.

As a result, the picture e! An image with uniform density and sharp line images was obtained.

Effects of the Invention As described above, the present invention has the remarkable effect that the electrophotographic photoreceptor requires fewer layers, that is, a scattering layer is not required, and that it is possible to precisely control the unevenness.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing an example of an electrophotographic photoreceptor manufactured by the manufacturing method of the present invention, Figure 2 is a schematic diagram showing an example of an apparatus for implementing the manufacturing method of the present invention, and Figure 6 is a cross-sectional view of an example of an electrophotographic photoreceptor produced by the manufacturing method of the present invention. FIG. 4 is a cross-sectional view showing the electrophotographic photoreceptor, and FIG. 4 is an explanatory view showing the optical path of light incident on the electrophotographic photoreceptor. Reference numeral 1 is a conductive substrate, 2 is an intermediate layer, 3 is a charge generation layer, and 4 is a conductive substrate.
is a charge transport layer, 5 is a coating layer, 6 is a substrate, 7 is a semiconductor laser, 8 is an optical system, 9 is a photosensitive drum, 10 is an incident laser beam, 11 is reflected light on the surface of the charge transport layer, 12 is a charge transport The reference numeral 13 indicates the light that penetrates into the layer, and the reflected light that is reflected at the bottom of the photoreceptor.

Claims (1)

[Claims] (1) In a functionally separated electrophotographic photoreceptor having a charge generation layer and a charge transport layer, minute depressions are formed on the surface of the charge generation layer by irradiating laser light within the range to which the charge generation layer is sensitive. and then laminating a charge transport layer.