JPH0342671A - Lamination type organic photosensitive body having under coating layer - Google Patents

Abstract

PURPOSE:To prevent the accumulation of the residual potential at and under a low temp. and low humidity by incorporating the laminate of a layer consisting of an alcohol soluble polyamide resin and a layer consisting of a water soluble resin in an under coating layer. CONSTITUTION:The layer 2 consisting of the water soluble resin and the layer 3 consisting of the alcohol soluble polyamide resin are laminated in this order on a conductive base 1, by which the under coating layer 4 is formed. A charge generating layer 5 and a charge transfer layer 6 are laminated on this under coating layer. Moisture is, therefore, supplied from the layer 2 of the water soluble resin to the layer 3 of the alcohol soluble polyamide resin under the low humidity, by which the moisture content of the layer 3 of the alcohol soluble polyamide resin is maintained substantially constant regardless of the humidity and temp. conditions. The accumulation of the residual potential at and under the low temp. and low humidity is prevented in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a layered organic photoreceptor, and more specifically, the present invention relates to a layered organic photoreceptor, in which a subbing layer, a charge generation layer, and a charge generation layer are formed on a conductive support.
In particular, the present invention relates to a layered organic photoreceptor in which the undercoat layer includes a laminate of a layer made of an alcohol-soluble polyamide resin and a layer made of a water-soluble resin.

In recent years, there have been publications such as Special Publication No. 55-42380 and Special Publication No. 6 (1-1).
As described in Japanese Patent No. 34099, in electrophotographic devices, a multilayer organic film is used, in which a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance are stacked on a conductive support. Photoreceptors have been developed and put into practical use. Such a laminated organic photoreceptor has a charge generation layer and a charge transport layer laminated in this order on a conductive support made of, for example, aluminum.

In these laminated organic photoreceptors, the charge generation layer is
For example, a charge-generating substance is made into a dispersion liquid with an appropriate organic solvent, a binder, and, if necessary, a plasticizer, etc., and this is applied onto a conductive support and dried to form a thin film. It is prepared by The charge transport layer is prepared by dissolving a charge transport substance together with a binder and, if necessary, a plasticizer, etc. in a solvent G, applying this to the charge generation layer, and drying it. , three rounds are made by thinning the film.

Conventionally, in such a laminated organic photoreceptor, a conductive support and a photosensitive layer, especially a conductive support and a photosensitive layer, have been repeatedly used to obtain uneven charging properties and to prevent defects from occurring in the resulting copied image. A resin layer called an undercoat layer or an intermediate layer is laminated between the charge generation layer and the charge generation layer.

For example, Japanese Patent Publication No. 58-45707 and Japanese Patent Publication No. 60-16
Japanese Patent No. 8157 proposes forming the undercoat layer from an alcohol-soluble polyamide resin. However, with this photoreceptor, residual potential accumulates when it is repeatedly charged under low temperature and low humidity conditions. Also, JP-A-58-1
Publication No. 06549 proposes forming the undercoat layer from a water-soluble polyvinyl butyral resin. According to this photoreceptor, image defects occur under high temperature and high humidity conditions.

In general, the undercoat layer is required to prevent charge injection from the conductive support, which causes image defects, and to not accumulate residual potential. As mentioned above, conventionally known subbing layers are required to have good adhesion or adhesion, but as mentioned above, the above-mentioned properties can be maintained regardless of ambient environmental conditions, especially fluctuations in temperature and humidity. Unable to meet all requests.

The inventors of the present invention have conducted extensive research to solve the above-mentioned problems in conventional laminated organic photoreceptors having an undercoat layer. Unexpectedly, by forming a laminate with a layer made of a water-soluble resin and a layer made of a water-soluble resin, there is no accumulation of residual potential even under low temperature and low humidity, and there is no image defect, and the adhesion with the photosensitive layer is improved. The inventors have discovered that it is possible to obtain an improved layered organic photoreceptor, leading to the present invention.

Originally, the purpose of disposing a layer made of alcohol-soluble polyamide resin as an undercoat layer is to prevent charge from being injected into the photosensitive layer from the conductive support, stabilize chargeability, and prevent image defects from occurring. This is to do so. Therefore, is alcohol allowed in the following? 9 A layer made of polyurethane resin is sometimes called a barrier layer. However, when a layer made of alcohol-soluble polyamide resin is used alone as an undercoat layer, residual potential is accumulated at low temperature and low humidity, as described above. According to the present inventors, the moisture content of the alcohol-soluble polyamide resin layer is significantly reduced under low humidity;
It has been found that increasing the resistance of the subbing layer results in the accumulation of residual potential.

Therefore, the present inventors formed a layer made of a water-soluble resin having water-retentive properties by closely adhering it to a layer of alcohol-soluble polyamide resin, and by laminating the undercoat layer in this way, the present inventors succeeded in reducing humidity. By supplying moisture from the layer of water-soluble resin to the layer of alcohol-soluble polyamide resin below, the moisture content of the layer of alcohol-soluble polyamide resin remains substantially constant regardless of humidity and temperature conditions, thus ensuring that The present invention was developed based on the discovery that the problem of residual potential accumulation under low humidity can be solved. Therefore, hereinafter, the layer made of water-soluble resin may be referred to as a water-retaining layer.

As described above, an object of the present invention is to provide a laminated organic photoreceptor that does not accumulate residual potential even under low temperature and low humidity conditions.

To solve the problem, the present invention provides a laminated organic photoreceptor comprising an undercoat layer, a charge generation layer, and a charge transport layer on a conductive support, in which the undercoat layer is a layer made of an alcohol-soluble polyamide resin. It is characterized by including a laminate with a layer made of a water-soluble resin.

In the present invention, the alcohol-soluble polyamide resin constituting one layer of the laminated undercoat layer is, for example, various copolymerized nylons as described in Japanese Patent Publication No. 5B-45707. As a specific example, for example,
Examples include nylon 6/66, nylon 6/66/610, and nylon 6/66/610/12. Such alcohol-soluble copolymerized nylon can be produced by hand as a commercially available product. Other specific examples include those obtained by chemically modifying homonylon, such as N-alkoxymethyl-modified nylon. Power)
For example, alcohol-resistant 1-grade nylon can also be used.
Ct-8000 and the like are commercially available.

In the present invention, water-soluble resins constituting other layers of the laminated undercoat layer include, in particular, water-soluble polyvinyl butyral resin, water-soluble polyamide resin, water-soluble polyvinyl alcohol resin, water-soluble cellulose ether, and two of these. A mixture of more than one species is preferably used.

The water-soluble polyvinyl butyral resin can be commercially available as Eslec W from Blockbuster Chemical Industry Co., Ltd., for example.

The water-soluble polyamide resin is a type of modified polyamide bulk resin, such as Torezin FS-35 manufactured by Teikoku Kagaku Sangyo ■.
0 or 500, it can be made by hand as AQ nylon manufactured by Toshi ■.

Various water-soluble polyvinyl alcohols are commercially available, and NH-26 manufactured by Nippon Gosei Chemical Industry Co., Ltd. is preferably used.

Various water-soluble cellulose ether resins are also commercially available, such as those with the general formula (wherein R is H, CH3, CzHtoll or C3) 1
6011 is shown. ) A cellulose ether resin represented by the following is preferably used.

The water-soluble polyvinyl butyral resin, water-soluble polyamide resin, water-soluble polyvinyl alcohol resin, and water-soluble cellulose ether are each soluble in lower aliphatic alcohols such as methanol, their aqueous solutions, or water, so they cannot be dissolved in these solvents. This is applied to a conductive support and dried by heating to form a resin layer.

The alcohol-soluble polyamide resin includes methanol,
Since it is soluble in lower aliphatic alcohols such as ethanol and propatool, the alcohol-soluble polyamide resin is dissolved in such alcohol to form a solution, which is applied onto the water-soluble resin layer and dried by heating. A resin layer is formed.

The thickness of the resin layer constituting the undercoat layer is usually 0.
．． It is in the range of 1 to 10 μm, preferably 0.5 to 3
It is in the μm range.

FIG. 1 shows an embodiment of a laminated organic photoreceptor having laminated undercoat layers as described above. That is, a layer 2 made of a water-soluble resin and a layer 3 made of an alcohol-soluble polyamide resin are laminated in this order on a conductive support 1 to form an undercoat layer 4, and a charge is generated on the undercoat layer. layer 5
and a charge transport layer 6 are laminated.

However, in the laminated photoreceptor according to the present invention, as shown in FIG. may be laminated in this order, and the charge generation layer 5 and the charge transport layer 6 may be laminated on the undercoat layer.

Furthermore, in the present invention, the layers 2 made of water-soluble resin and the layers 3 made of alcohol-soluble polyamide resin are alternately laminated, and at least one layer may have two or more layers.

For example, in the photoreceptor shown in FIG. 3, a layer 2 made of a first water-soluble resin, a layer 3 made of an alcohol-soluble polyamide resin, and a layer 2 made of a second water-soluble resin are disposed on a conductive support 1. are laminated in this order to form an undercoat layer 4, and a charge generation layer 5 and a charge transport layer 6 are laminated on the undercoat layer.

In addition, in the photoreceptor shown in FIG.
A layer 3 made of a first alcohol-soluble polyamide resin, a layer 2 made of a water-soluble resin, and a layer 3 made of a second alcohol-soluble polyamide resin are laminated in this order on top, and an undercoat layer 4 is formed. A charge generation layer 5 and a charge transport layer 6 are laminated on the undercoat layer.

In the present invention, the charge-generating substance for forming the charge-generating layer is not particularly limited, and examples thereof include X-type metal-free phthalocyanine, metal-free cyanine pigment, ab-based pigment, squarylium-based pigment, etc. Among these, X-type metal-free phthalocyanine is preferably used. Further, the binder resin for forming the charge generation layer is not particularly limited, and examples thereof include polystyrene, styrene-acrylonyl-
Lyle copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyaryl 1-resin, phenoxy Heat treatment of resins, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, etc. Plastic or thermosetting resins are used.

The content of the binder resin in the charge generation layer is preferably as small as possible, but a range of 5 to 50% by weight is usually appropriate. Further, the thickness of the charge generation layer is usually 0.
The range is from 0.05 to lpm.

The solvent used to form the charge generation layer is a solvent that does not dissolve the resin constituting the undercoat layer in contact with the charge generation layer, but dissolves the binder resin used. Specific examples of such solvents include, for example, Hensen, toluene, xylene,
Methylene chloride, 1:Irophor 11.1,2-dichloroethane, 1,1. ．． Examples include 2.2-tetrachloroethane, monochlorobenzene, dichloroenzene, ethyl acetate, phthyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexanone, methyl cellosolve, and ethyl cellosolve.

The charge transport material for forming the charge transport layer is not particularly limited, but examples include polyN-hinylcarbadul and its derivative FA, poly γ-carhazolylethylglutame-1 - and derivatives thereof, pyrene-formaltehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, igitazole derivatives, 9-(p-jethylachnostyryl)anthracene, 1,1- Bis(4-dihendylaminophenyl)propane, styryl anthracene, styryl pyrazoline, phenylhydrazones, α-
Mention may be made of electron-donating compounds or polymers such as stilbene derivatives.

The binder resin used to form the charge transport layer is one that is soluble in an organic solvent and has high compatibility with the charge transport substance so that a solution of the charge transport substance can be stably and easily prepared. Furthermore, resins whose coatings have high mechanical strength, transparency, and insulation properties are preferably used at low temperatures. Therefore, specific examples of such binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc. Combination, polyvinyl acetate, polyvinylidene chloride, polyaryl 1 to resin, phenoxy resin, polycarbonate 1 to 1, cellulose acetate resin, ethyl cellulose resin, 3 vinylyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbasol, Examples include thermoplastic or thermosetting resins such as acrylic resins, silicone resins, epoxy resins, melamine resins, urethane resins, phenolic resins, and alkyd resins.

In addition, examples of the solvent include tetrahydrofuran, dioxane, toluene, monochlorobenzene, methylene chloride, chloroform, 1,2-dichloroethane, l, L2
．． Examples include 2-tetrachloroconicune.

The content of the charge transport substance in the charge transport layer is usually 1
A preferable range is 0 to 60% by weight, and the thickness of the charge transport layer is usually 5 to 100 μm.

The laminated organic photoreceptor according to the present invention has the following steps:
An undercoat layer is formed by laminating a layer made of an alcohol-soluble borium resin and a layer made of a water-soluble resin on a conductive support, and the undercoat layer is coated with an organic solvent and a binder resin together with a charge-generating substance. , and if necessary, a dispersion containing a plasticizer etc. is applied to the above-mentioned undercoat layer 2 and dried to form a charge generation layer, and then an organic solvent and a binder are further applied thereon together with a charge transport substance. It can be obtained by applying a solution containing an adhesive and, if necessary, a plasticizer, etc., and drying it to form a charge transport layer.

However, in the present invention, a charge transport layer may be formed on the undercoat layer, and a charge generation layer may be formed on the charge transport layer.

Effects of the Invention As described above, the laminated organic photoreceptor according to the present invention has a layer made of an alcohol-soluble polyamide resin and a layer made of a water-soluble resin between the conductive support and the photosensitive layer, especially the charge generation layer. According to such a laminated organic photoreceptor, residual potential does not accumulate during repeated use, regardless of changes in environmental conditions such as temperature and humidity, and , it is possible to obtain a copy image free of image defects. Moreover, in the sub-layer with no distribution,
The layer made of water-soluble resin has poor adhesion to the conductive support and the photosensitive layer.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 A solution consisting of 74.3 parts by weight of water-soluble polyvinyl butyral resin (Eslec W2O 1,28,5% aqueous solution manufactured by Block Chemical Industry Co., Ltd.) and 300 parts by weight of methanol was heated to a tube with an outer diameter of 30 m.
Dip coating on the outer surface of an aluminum cylindrical tube of 9 m
It was dried by heating at 0° C. for 1 hour to form a water-retaining layer with a thickness of 1 μm.

Next, alcohol-soluble polyamide resin (C manufactured by Toshi)
A solution consisting of 20 parts by weight of M-8000, nylon 6/66/610/12 copolymer) and 313 parts by weight of methanol was dip-coated onto the above water-retaining layer, and dried by heating at 90°C for 1 hour to obtain a film thickness of 1 μm. A barrier layer was formed, thus forming a laminated subbing layer.

Next, 3 parts by weight of X-type metal-free phthalocyanine, 6 parts by weight of vinyl chloride-ethylene copolymer (VE manufactured by Block Chemical
-U) and 200 parts by weight of tetrahydrofuran was pulverized in a ball mill for 2 hours to obtain a dispersion,
This was coated on the undercoat layer by dip coating and dried by heating at 90° C. for 30 minutes to form a charge generating layer having a thickness of 0.5 μm.

Next, 130 parts by weight of polycarbonate (Nipiron E-2000 manufactured by Mitsubishi Gas Chemical Industry Co., Ltd.), 104 parts by weight of a charge transport substance represented by the structure, and 10 parts by weight of 1,2 dichloromethane were added.
A solution consisting of 0.04 parts by weight is dip-coated onto the charge generation layer, and heated and dried while increasing the temperature from 60 to 110°C at a rate of 1°C/min to form a charge transport layer. A laminated photoreceptor as shown in FIG. 1 was manufactured.

Example 2 7 A laminated photoreceptor as shown in FIG. 2 was produced in the same manner as in Example 1, except that a barrier layer and a water retention layer were formed in this order on a conductive support.

Example 3 A laminated photoreceptor as shown in FIG. 3 was produced in the same manner as in Example 1, except that a water-retaining layer, a barrier layer, and a water-retaining layer were formed in this order on a conductive support. .

Example 4 A laminated photoreceptor as shown in FIG. 4 was produced in the same manner as in Example 1, except that the barrier layer, water retention layer, and barrier layer were formed in this order on the conductive support. .

Example 5 In the same manner as in Example 1, except that a water-retaining layer was formed using a solution consisting of 20 parts by weight of water-soluble polyvinyl alcohol resin (NH-26 manufactured by Nippon Gosei Kagaku Kogyoen) and 480 parts by weight of water. A laminated photoreceptor as shown in FIG. 1 was manufactured.

Example 6 8 A laminated photoreceptor as shown in FIG. 2 was produced in the same manner as in Example 5, except that a barrier layer and a water-retaining layer were formed in this order on a conductive support.

Example 7 Water-soluble polyamide resin (Torezin FS manufactured by Teikoku Kagaku Kogyo ■)
-500, 20% emulsion with alcohol/water ratio 1/1) 50
The same procedure as in Example 1 was carried out, except that a water-retaining layer was formed using a solution consisting of 200 parts by weight and 200 parts by weight of methanol.
A laminated photoreceptor as shown in FIG. 1 was manufactured.

Example 8 A laminated photoreceptor as shown in FIG. 2 was produced in the same manner as in Example 7, except that a barrier layer and a water-retaining layer were formed in this order on a conductive support.

Example 9 10 parts by weight of water-soluble cellulose ether resin (Sesca MC-3000P manufactured by Daiichi Kogyo Seiyaku ■) and 490 parts of methanol
A laminated photoreceptor as shown in FIG. 1 was produced in the same manner as in Example 1, except that the water-retaining layer was formed using a solution consisting of parts by weight.

9 Example 10 A laminated photoreceptor as shown in FIG. 2 was produced in the same manner as in Example 9, except that a barrier layer and a water-retaining layer were formed in this order on a conductive support.

Comparative Example 1 Alcohol-soluble boria resin (CM-80 manufactured by Toshi ■)
A laminated photoreceptor was manufactured in the same manner as in Example (Example 1), except that an undercoat layer consisting of a single resin layer was formed using a solution consisting of 2 parts by weight of Offl and 313 parts by weight of methanol.

Comparative Example 2 An undercoat layer consisting of a single resin layer was prepared using a solution consisting of 74.3 parts by weight of water-soluble polyvinyl alcohol resin (Eslec W2O 1, 28.5% aqueous solution manufactured by Block Chemical Industry ■) and 300 parts by weight of methanol. A laminated photoreceptor was manufactured in the same manner as in Example 1, except that .

Comparative Example 3 Water-soluble polyvinyl alcohol resin (Hiki Gosei Chemical Industry ■
A laminated photoreceptor was produced in the same manner as in Example 1, except that an undercoat layer consisting of a single resin layer was formed using a solution consisting of 20 parts by weight of NH-26) manufactured by NH-26) and 4800 parts by weight of water. did.

Comparative Example 4 Water-soluble polyamide resin (Torezin FS manufactured by Teikoku Kagaku Kogyo ■)
-500, 20% emulsion with alcohol/water ratio 1/1) 50
Except that an undercoat layer consisting of a single resin layer was formed using a solution consisting of 490 parts by weight and 490 parts by weight of methanol.
A laminated photoreceptor was manufactured in the same manner as in Example 1.

Comparative Example 5 10 parts by weight of water-soluble cellulose ether resin (Seska MC-3000P manufactured by Daiichi Kogyo Seiyaku O@) and 49 parts by weight of methanol
A laminated photoreceptor was manufactured in the same manner as in Example 1, except that the undercoat layer consisting of a single resin layer was formed using a solution consisting of 0 parts by weight.

Comparative Example 6 A laminated photoreceptor was manufactured in the same manner as in Example 2, except that the undercoat layer was not applied.

For each of the laminated organic photoreceptors obtained as described above, using the apparatus shown in FIG.
Its performance was evaluated. This device measures the surface potential at a portion of the photoreceptor corresponding to the development position in the laser beam printer at the top and bottom of the printer. First, while rotating the photosensitive drum 1 at 41 rpm, the surface potential was charged to -1650V with a corona discharger (scorotron) 2.
Subsequently, the LED 3 for weight removal was irradiated, and at this time, the surface potential at the position of the probe 4 corresponding to the development position was determined as the initial potential VL. Next, a semiconductor laser for exposure is used to
80nm, 1.28μJ/cJ laser light,
The surface potential of the photoreceptor at that time was determined as the residual potential VR.

Furthermore, laser light was continuously irradiated for 10 minutes, and the initial potential VL and residual potential VR were determined as charging characteristics after fatigue.

The results are shown in Table 1.

Next, each photoreceptor was installed in a reversal development type optical printer, copies were made, and the presence or absence of defects in the resulting images was examined. The results are shown in Table 1.

In Comparative Examples 1 and 2) in which the undercoat layer was formed of a single resin layer made of an alcohol-soluble polyamide resin, the residual potential increased after fatigue at low temperature and low humidity. On the other hand, when the undercoat layer was formed from a single layer made of water-soluble resin (Comparative Examples 2 to 5), many image defects such as black spots and black streaks occurred, especially under high temperature and high humidity conditions. . When no undercoat layer was formed (Comparative Example 6), image defects were significant even at low temperature and low humidity.

In contrast to these comparative examples, according to the present invention, no image defects occur even under severe conditions of high temperature and low temperature and low humidity, and there is no increase in residual potential even after fatigue.

The undercoat layer also has poor adhesion to the conductive support and the photosensitive layer.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts showing one embodiment of a layered organic photoreceptor having a laminated undercoat layer according to the present invention, and FIG. 2 is another embodiment of the layered organic photoreceptor according to the present invention. 3 and 54 are also sectional views showing still another embodiment of the multilayer organic photoreceptor according to the present invention. FIG. 5 is a diagram of an apparatus for evaluating the performance of a laminated organic photoreceptor. DESCRIPTION OF SYMBOLS 1... Conductive support, 2 and 2'... Layer made of water-soluble resin, 3 and 3'... Layer made of alcohol-soluble polyamide resin, 4... Undercoat layer, 5... Charge generation layer, 6... Charge transport layer, ] 1... Photosensitive drum,
12... Kurrona discharger, 13... L E for static elimination
D, 14... Probe for surface potential measurement.

Claims (2)

[Claims] (1) In a multilayer organic photoreceptor comprising an undercoat layer, a charge generation layer, and a charge transport layer on a conductive support, the undercoat layer has a layer made of an alcohol-soluble polyamide resin and a layer made of a water-soluble resin. A laminated organic photoreceptor comprising a laminated body of. (2) The water-soluble resin is a water-soluble polyvinyl butyral resin,
The laminated organic photoreceptor according to claim 1, characterized in that it is a water-soluble polyamide resin, a water-soluble polyvinyl alcohol resin, and/or a water-soluble cellulose ether.