JPH05333581A - Laser beam photosensitive body - Google Patents

Abstract

PURPOSE:To provide the laser beam photosensitive body which reduces the work cost of a base and eliminates picture quality defects such as interference fringes, flaws or porosity. CONSTITUTION:For this laser beam photosensitive body, a first intermediate layer 2 containing conductive powder 3 is formed on the surface of a cylindrical body (base 1) obtd. by executing ironing working or drawing working to a press formed aluminium containing manganese, by weight, of (0.3-1.5%) and a second intermediate layer 4 containing insulation powder 5 is formed on the first intermediate layer, and a photosensitive layer is provided on the second intermediate layer. The second inter-mediate layer 4 is provided with a function for blocking change injection from the first intermediate layer 2 and a function for scattering laser beams and formed by dispersing light scattering powder in binder resin. As the powder, insulation powder 5 without charge injection property and having increased light scattering property is preferable and insulation metal oxide or resin powder is used. Further, the photosensitive layer is composed of a charge generation layer 6 and a charge transfer layer 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member having two intermediate layers, and more particularly to a photosensitive member used for laser light exposure.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member has a basic structure in which a photosensitive layer is formed on a conductive support. However, the adhesion of the photosensitive layer is improved, the coating property is improved, the charging property is improved, It is effective to provide an intermediate layer (undercoat layer) for the purpose of preventing unnecessary charge injection, protecting against electrical breakdown, covering defects on the substrate, and the like, and various materials have been used. If the main purpose is to cover defects on the substrate, the film thickness of the intermediate layer must be set relatively thicker than the defects. However, when the thickness of the intermediate layer is increased, residual charges are accumulated and cause a change in charging characteristics of the photoconductor. In order to prevent the accumulation of residual charges, a method is known in which conductive powder is dispersed in the intermediate layer to reduce the resistance. For example, carbon black is disclosed in
JP-A-55-250 discloses metal particles disclosed in JP-A-152733.
No. 30, a conductive metal oxide particle is disclosed in JP-A-57-8.
Various conductive powders such as those described in Japanese Patent No. 1269 are used. The intermediate layer containing the conductive powder is also called a conductive layer. When the conductive powder is contained in the intermediate layer, the layer becomes porous, which may interfere with the formation of the photosensitive layer thereon. Further, since the conductive layer powder has a property of injecting charge into the photosensitive layer, if the photosensitive layer is directly formed on the conductive layer, the charging performance of the photosensitive layer is deteriorated. For these reasons, as described in JP-A-55-73054 and JP-A-58-91460,
It is known to provide an intermediate layer having a barrier function on the conductive layer.

On the other hand, in recent years, the electrophotographic photosensitive member is often mounted on a laser printer. When the photoconductor is irradiated with laser light, there is a problem that interference fringes are generated in an image due to interference of the laser light. As one of means for preventing this, there is known a method of roughening a conductive layer to scatter laser light. For example, a method of adding a specific powder other than the conductive powder to the conductive layer is described in JP-A-60-256153, and a method of incorporating a spherical resin fine powder is described in JP-A-63-163468. Has been done. However, the conductive layer is originally a coating layer formed of a dispersion type coating material, and it is not preferable to add powder in addition to the stability of the coating material. That is, the composition of the paint is likely to change, and it becomes difficult to always maintain a predetermined function (light scattering property).

[0004]

In order to reduce the cost of the photoconductor, the present inventor has proposed an electrophotographic photoconductor in which a thick conductive layer is formed without mirror cutting the surface of the substrate. (Japanese Patent Laid-Open No. 3-48255). As a substrate for the electrophotographic photosensitive member which does not require mirror surface cutting, a substrate (EI tube) extruded from aluminum containing 0.3 to 1.5% by weight of manganese and subjected to an ironing process, and a substrate subjected to a drawing process (ED
Tube) can also be used. Although this substrate has sufficiently high dimensional accuracy, it has a drawback that the surface roughness is still insufficient. Further, since the conductive layer in the photoconductor does not have an interference prevention function, it cannot be used for a laser beam photoconductor.

The present invention has been made in view of the above-mentioned problems in the prior art. That is, an object of the present invention is to reduce the processing cost of the substrate and to provide a laser photoconductor having no image quality defect.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventor has provided a first intermediate layer containing a conductive powder on the surface of an ironed substrate, and further provided a light scattering property on the first intermediate layer. A laser photoconductor in which a second intermediate layer containing an insulating powder is formed to provide a photosensitive layer on the second intermediate layer can provide not only interference fringes but also an image free from image defects due to scratches or scratches. The inventors have found that and completed the present invention. That is, the present invention is extruded manganese 0.3-1.
Forming a first intermediate layer containing a conductive powder and a second intermediate layer containing an insulating powder on the surface of a cylindrical body obtained by ironing or drawing aluminum containing 5% by weight. It is a laser beam photoreceptor having a photosensitive layer provided thereon.

The present invention will be described in detail below. First, a brief description will be given with reference to FIG. 1, which is a schematic cross-sectional view of a part of the laser photoconductor of the present invention. Reference numeral 1 is a cylindrical substrate obtained by extrusion-molding aluminum containing a small amount of manganese, and then performing an ironing process or a drawing process. Reference numeral 2 is a first intermediate layer, which is formed by applying a coating liquid in which the conductive powder 3 is dispersed in a suitable resin onto the substrate 1. Reference numeral 4 denotes a second intermediate layer, which is formed by applying a coating liquid in which the insulating powder 5 is dispersed in a binder resin or the like onto the first intermediate layer 2. Reference numerals 6 and 7 denote a charge generating layer and a charge transporting layer, which are formed by dispersing a charge generating substance and a charge transporting substance in a binder resin, respectively, and form a photosensitive layer.

The substrate 1 of the present invention obtained by the ironing process is obtained by extruding an aluminum material and then performing the ironing process. Specifically, the aluminum material is extruded into a tubular shape and then The size is corrected by ironing through a die having a predetermined size to obtain a cylindrical body with improved surface smoothness. When ironing, the aluminum material needs to be slippery. Since pure aluminum lacks in slipperiness and may cause streak-like scratches on the surface due to ironing, in the present invention, a small amount of manganese is added to the aluminum material in order to improve slipperiness. There is a need. The amount of manganese is 0.3 to 1.5% by weight
The range is appropriate. If the amount of manganese is less than the above range, the effect of improving the slipperiness cannot be sufficiently exhibited, and if it is too large, crystal precipitation occurs and defects occur.

The surface roughness of the ironed cylinder is 0.8 to 3.0 μm in Rmax and 0.03 to Ra in Ra.
It is about 0.06 μm, and the dimensional accuracy is 100 μm or less in terms of outer diameter runout (the fluctuation range of the outer circumference of the cylinder when rotated around the axis of the cylinder). On the other hand, when drawing is used instead of ironing, the surface roughness is R
1 to 3.0 μm in max and 0.05 to 0.1 μm in Ra
The dimensional accuracy is 100 μm or less in terms of outer diameter deflection, but becomes smaller when the diameter is small. Therefore, it is advantageous to use the EI tube when the outer diameter is 50 mm or more and the ED tube when the outer diameter is 40 mm or less. In either case, the manganese particles may come off during processing and soot may occur, so in the present invention, a coating layer is formed on the surface to conceal the defects.

The coating layer can be formed by applying a resin paint in which the conductive powder 3 is dispersed. When the conductive powder 3 is not included, the residual potential of the photosensitive layer formed on the conductive powder 3 is increased, so that it is necessary to include the conductive powder 3. Examples of the conductive powder 3 include, for example, JP-A-55-25030, JP-A-56-41803, and JP-A-56-41803.
Ag, Cu, described in Japanese Patent Publication No. 143443, etc.
Metal particles such as Ni and Au, carbon, ZnO, Sn
O ₂ , Al ₂ O ₃ , In ₂ O ₃ , MgO, BaO, Mo
O ₃ , CuO, etc. or their composite oxides, TiO ₂
Powder having a coating layer of SnO ₂ —Sb ₂ O _{3 on} its surface.

The resin in which the powder is dispersed has (1) strong adhesion to the substrate 1, (2) good dispersibility of the powder, and (3) sufficient solvent resistance. Although it can be used as long as it satisfies the conditions such as that, thermosetting resins such as curable rubber, polyurethane resin, epoxy resin, alkyd resin, polyester resin, silicone resin, acrylic-melamine resin, and phenol resin are particularly preferable. Used for. The coating layer has a volume resistivity of 10 ⁸ to 10
It is preferably about ¹³ Ωcm, and the film thickness is 5 to 5.
The thickness is preferably about 25 μm. In the present invention, this layer is referred to as the first intermediate layer 2.

In the present invention, the second intermediate layer 4 is formed on this.
To provide. This layer has a function of blocking charge injection from the first intermediate layer 2 and a function of scattering laser light. Therefore, a powder having a light scattering property is dispersed in a resin which is usually used as a binder for the undercoat layer to form the second intermediate layer 4. The larger the difference in refractive index between the powder and the binder resin, the greater the light scattering property. As the powder used here, insulating powder 5 having no charge injection property and a large light scattering property is preferable, and particularly Al ₂ O ₃ , MgO or TiO ₂ among the insulating metal oxides is preferable. , Zr
O _{2 and the} like and those obtained by surface-treating these are preferable.
Further, resin powder such as acrylic resin, styrene resin, polycarbonate, polyester, polyamide, silicone resin, melamine resin and urea resin can be used.

As the binder resin, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine,
Examples thereof include cellulose ethers, cellulose esters, polyamides, polyurethanes, casein, gelatin, polyglutamic acid, starch acetate, amino starch, polyacrylic acid salts, polyacrylamides and the like. Of these resins, polyamide is preferred. Further, a resin may be used in combination with the organometallic compound and / or the silane coupling agent. Organometallic compounds are disclosed in JP-A-61-94057.
Although it is described in detail in the publication, typical examples thereof include zirconium chelate compounds, zirconium alkoxides, titanium orthoesters, polyorthotitanate esters, titanium chelates and the like. Second middle layer 4
Preferably has a volume resistivity of about 10 ¹⁰ to 10 ¹⁴ Ωcm and a thickness of about 0.5 to 3 μm.

The photosensitive layer formed thereon may be a single layer or a laminated structure. In the case of a single-layer structure, a charge generating substance such as a phthalocyanine or a squarylium compound is dispersed in a resin together with a charge transporting substance if necessary. Further, in the case of a laminated structure, a layer in which the charge generation layer 6 and the charge transport layer 7 are functionally separated may be used. The charge generation layer 6 is formed by dispersing a charge generation substance in a binder resin as needed. Examples of the charge generating substance include selenium and selenium alloys; CdS, CdSe, CdSSe, Z
Inorganic photoconductors such as nO; azo pigments such as metal or metal-free phthalocyanine pigments, bisazo pigments, trisazo pigments, squarylium compounds, azurenium compounds, berylylene pigments, indigo pigments, polycyclic quinone pigments and the like. As the binder resin, for example, polycarbonate, polystyrene, polyester, polyvinyl butyral, methacrylic acid ester polymer or copolymer, vinyl acetate polymer or copolymer, cellulose ester or ether, polybutadiene, polyurethane, epoxy resin, etc. are known. What is used.

A charge transport layer 7 is formed on the charge generation layer 6. The charge transport layer 7 is mainly composed of a charge transfer substance. The charge transfer substance is not particularly limited as long as it is transparent to visible light and has a charge transporting ability. Specifically, imidazole,
Pyrazoline, thiazole, oxadiazole, oxazole, hydrazone, ketazine, azine, carbazole,
Examples thereof include polyvinylcarbazole and the like and derivatives thereof, triphenylamine derivatives, stilbene derivatives, benzidine derivatives and the like. A binder resin is used in combination if necessary, and examples of the binder resin include polycarbonate, polyarylate, polyester, polystyrene, styrene-acrylonitrile copolymer, polysulfone, polymethacrylic acid ester, and styrene-polymethacrylic acid ester. Examples thereof include copolymers.

[0016]

The operation of the present invention is as follows.
By extruding using aluminum containing 5% by weight, the slipperiness of aluminum is improved, and the generation of streaks and scratches during molding is prevented. Further, by subjecting the cylindrical body to the ironing process or the drawing process, it is possible to obtain a product having improved surface smoothness and dimensional accuracy. Next, the first intermediate layer 2 is applied onto the cylindrical body to completely hide the defects remaining on the surface. Since the conductive powder 3 is dispersed in this layer, the residual charges are not accumulated, the film thickness can be made 5 to 25 μm, and the concealing effect is great. Moreover, the second intermediate layer 4 formed on the first intermediate layer 2 acts as a barrier layer for preventing charge injection from the first intermediate layer 2, and the surface of the second intermediate layer 4 is dispersed by the dispersion of the insulating powder 5. Since it has a light-scattering property, no interference fringes are generated even when it is used as a laser photoconductor.

[0017]

The present invention will be described in more detail with reference to the following examples. In addition, "part" in an Example and a comparative example means a weight part. Example 1 Aluminum containing 1.2% by weight of manganese (JIS
3003) is extruded and 110mmφ × 200m
A cylinder having a size of m and a thickness of 1.1 mm was formed. 0.8mm (wall thickness) x 84mmφ x 360mm by this ironing process using a 84mmφ die
The cylinder of was produced. The surface roughness of the produced cylinder is Rma.
x2.5 μm. This cylinder was cut into a length of 340 mm and used as a substrate. On the other hand, 40 parts of rutile-type titanium oxide powder having a content of 43% by weight treated with tin oxide was mixed with 20 parts of acrylic resin (trade name: Acridic A405, manufactured by Dainippon Ink and Chemicals) having a solid content of 60%, and Mix with a solution of 100 parts of toluene, then 6 with a ball mill.
Dispersed over time. The obtained dispersion liquid was applied onto the above substrate by a dip coating method, and heated at 150 ° C. for 30 minutes to be heat-cured to form a first intermediate layer having a film thickness of 15 μm. The surface of this first intermediate layer has a roughness Rmax of 0.5 μ.
m, and the resistivity was 10 ¹⁰ Ωcm. Further, 5 parts of copolymerized nylon resin (trade name: Amilan CH8000, manufactured by Toray Industries, Inc.) was added to 60 parts of methanol and 4 parts of butanol.
It was dissolved in 0 part of the mixed solution, 5 parts of rutile type titanium oxide powder was added to this solution, and the mixture was dispersed for 2 hours by a ball mill. This was apply | coated on the said 1st intermediate | middle layer, it dried at 100 degreeC for 5 minute (s), and the 0.8 m-thick 2nd intermediate | middle layer was formed.

Next, 3 parts of polyvinyl butyral (trade name: S-REC BM-1, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 100 parts of cyclohexanone in advance, and 3 parts of X-type metal-free phthalocyanine was mixed with a sand mill. After dispersion treatment for 5 hours, it was diluted with cyclohexanone to prepare a charge generation layer forming coating solution having a solid content concentration of 3.5% by weight. This coating solution is applied onto the second intermediate layer, and the temperature is 100 ° C.
And dried for 10 minutes to form a charge generation layer having a thickness of 0.25 μm. Furthermore, 4 parts of N, N'-diphenyl-N, N'-bis (3-tolyl) benzidine is used as a charge transport material,
Chlorobenzene 40 with 6 parts of polycarbonate Z resin
Part was dissolved. The obtained solution was applied onto the above charge generating layer by a dip coating method to form a charge transporting layer having a film thickness of 19 μm to prepare a laser photoconductor.

Then, using a semiconductor laser having a wavelength of 785 nm and an intensity of 7 erg / cm ^{2 on} the surface of the photoconductor as an exposure light source, and using a laser printer of imagewise exposure by image light scanning, the image quality characteristics of the laser photoconductor described above. Was evaluated. This is the charging potential of -600
V, set the potential after the whole surface exposure to -140V,
It has a process of reversal development. The laser photosensitive member had a constant exposure potential, and no interference fringes were generated in the printed image. In addition, streaks due to the surface roughness of the substrate,
No image defects such as scratches were found.

Comparative Example 1 Aluminum containing 0.1% by weight of manganese (JIS
6063) was extruded and molded in the same manner as in Example 1 and subjected to an ironing process in the same manner as in Example 1 to produce a cylinder.
The surface roughness of this cylinder was Rmax 2.8 μm,
A thin line with a maximum depth of 6 μm was partially generated. A laser photoconductor was prepared in the same manner as in Example 1, using the above-mentioned cylinder as a substrate. When the image quality was evaluated in the same manner as in Example 1, the obtained image was inferior in image quality because defects such as scratches were found corresponding to the streaks.

Comparative Example 2 Aluminum containing 1.6% by weight of manganese was extruded in the same manner as in Example 1 and subjected to an ironing process in the same manner to produce a cylinder. The surface roughness of this cylinder is Rmax
Although it was 1.9 μm, spots with a maximum depth of 8 μm were partially generated. A laser photoconductor was prepared in the same manner as in Example 1, using the above-mentioned cylinder as a substrate. When the image quality was evaluated in the same manner as in Example 1, the obtained image was inferior in image quality because defects such as scratches were found corresponding to the streaks.

COMPARATIVE EXAMPLE 3 In Example 1, a laser-photosensitive member was prepared in which the powder was not dispersed in forming the second intermediate layer and was formed of only nylon resin. When the characteristics of this photosensitive member were evaluated by a laser printer, the potential after the whole surface exposure was −100 to −1.
A fluctuation was seen over 60V. Looking at the printed image, the image quality was inferior because a striped pattern occurred on the black background.

Example 2 In Example 1, when forming the first intermediate layer, 10 parts of carbon black (trade name: Honarch 1300, manufactured by Cabot Co.) and a heat-reactive phenol resin (trade name:
BKS-2710C, Showa High Polymer Co., Ltd. (30 parts) and butanol (10 parts) were mixed, and a coating solution obtained by dispersing for 5 hours in a ball mill was used. did. The image quality of this photoconductor was evaluated in the same manner as in Example 1. As a result, an image of good quality with no defects was obtained.

Example 3 6 parts of N-methoxymethylated nylon 12 resin (trade name: Resin Z550, manufactured by Teikoku Chemical Industry Co., Ltd.) was dissolved in 60 parts of methanol and 34 parts of n-butanol. Alumina-coated titanium oxide powder (trade name: SR-
1T, manufactured by Sakai Chemical Industry Co., Ltd. was mixed in a double amount of resin content, and then dispersed with 2 mmφ glass beads by a paint shaker for 30 minutes. The obtained coating liquid was applied instead of the second intermediate layer forming coating liquid in Example 1,
A laser photoconductor was prepared in the same manner except the above. When the characteristics of this photoreceptor were evaluated with a laser printer,
The sensitivity was improved as compared with the photoreceptor of Example 1, and an exposure potential of -140 V was obtained at a laser intensity of 6 erg / cm ² . In addition, when the image quality characteristics were evaluated, there were no problems such as interference fringes.

[0025]

According to the present invention, it is possible to reduce the processing cost because the mirror cutting of the substrate is unnecessary.
In addition, it is possible to provide a laser photoconductor having no image defects such as interference fringes and scratches and stripes.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a laser photoconductor of the present invention.

[Explanation of symbols]

1 ... Substrate, 2 ... First intermediate layer, 3 ... Conductive powder, 4 ... Second intermediate layer, 5 ... Insulating powder, 6 ...
-Charge generation layer, 7 ... Charge transport layer.

Claims (1)

[Claims] 1. Extruded manganese 0.3-1.5
A first intermediate layer containing a conductive powder and a second intermediate layer containing an insulating powder thereon are formed on the surface of a cylinder obtained by ironing or drawing aluminum in a weight percentage of A laser beam photosensitive member comprising a photosensitive layer provided on.