JP3171295B2 - Electrophotographic photoreceptor, apparatus unit having the same, and electrophotographic apparatus - Google Patents

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 and an electrophotographic apparatus which can be widely used in electrophotographic applications such as an electrophotographic copying machine, a laser beam printer, a CRT printer, and an electrophotographic plate making system. In particular, the present invention relates to an electrophotographic photosensitive member and an electrophotographic apparatus having excellent durability.

[0002]

2. Description of the Related Art In recent years, various photoconductors have been developed as photoconductive materials for electrophotographic photoconductors and have been mounted on copiers and printers. However, these photoconductors have generally been considered to have a major drawback in that they have low durability. The durability is roughly classified into durability of electrophotographic characteristics such as sensitivity, residual potential, charging ability, image blur, background fogging, and mechanical durability such as abrasion and scratches on the surface of the photoreceptor due to rubbing. However, particularly poor mechanical durability is a major factor in shortening the life of the photoconductor, and development of a photoconductor having more excellent mechanical durability is desired. In addition, the surface layer of the photoreceptor, particularly under high humidity, adhesion of a low-resistance substance generated by ozone generated during corona charging, or filming based on poor cleaning of toner,
There is a factor that causes image deterioration due to fusion, deposition of a low-molecular charge transport material, and the like. Therefore, in addition to the above mechanical durability, releasability from various kinds of deposits is required. For such demands, that is, to improve mechanical durability against wear and scratches,
It is known that, in addition to water repellency, it is effective to disperse a lubricant on the surface of the photoreceptor in order to prevent toner fusion and the like.

On the other hand, the surface of the photoreceptor is always degraded by ozone generated during corona charging, and it is necessary to polish the surface of the photoreceptor to always bring out a new surface in order to obtain a high-quality image. In particular, if the polishing action is insufficient, the image is crushed as the image is durable, and so-called image blur occurs, in which characters cannot be read. Conventional photoreceptors have poor mechanical durability. As a result, the surface of the photoreceptor is appropriately shaved together with the durability, and a new surface always appears. However, in the photoreceptor in which the lubricant is dispersed, as a result of improved mechanical durability, the amount of abrasion of the photoreceptor surface is significantly reduced, so that the deteriorated surface layer is not abraded, and image blur occurs as the durability increases. At present, it is difficult to commercialize a highly durable photoconductor.

On the other hand, if the polishing action is too strong, the surface layer is a charge transporting layer, so that the surface layer is scraped, resulting in a decrease in charging ability, an increase in dark decay, an increase in residual potential, or an unstable potential. As a result, there is a problem that ground fogging occurs on the image as the image is durable, for example, the sensitivity is lowered and the contrast potential cannot be sufficiently obtained.It is currently extremely difficult to control abrasion and lubricity in a well-balanced manner. Was.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member having high durability which meets the above-mentioned requirements. That is, an object of the present invention is to provide an electrophotographic photoreceptor that has durability against abrasion of the surface due to rubbing and generation of scratches, and has high durability capable of obtaining high-quality images without image blur. To provide. Another object of the present invention is to provide an electrophotographic photoreceptor having good cleaning properties and high durability without toner adherence to the photoreceptor surface layer. Further, another object of the present invention is to have a high durability in which a high-quality image can be obtained without image blurring, background fogging, without a decrease in charging ability, a decrease in sensitivity, and no accumulation of residual potential in a repetitive electrophotographic process. An object of the present invention is to provide an electrophotographic photosensitive member. Another object of the present invention is to provide an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0006]

Means for Solving the Problems That is, the present invention is, electrostatic
Photographic photoreceptor and sponge row arranged in contact with the photoreceptor
Having two kinds of cleaning means of color and blade
An electrophotographic photoreceptor for a photographic device, comprising a charge generation layer and a charge transport layer on a conductive support in this order.
In the electrophotographic photoreceptor feeding layer is a surface layer, the charge transportation
Okuso lubricant, Bisufu a weight average molecular weight from 100000 to 150000
Enol Z-type polycarbonate resin and the following formula
The triarylamine represented by (1) is contained, and the content of the lubricant is 2 to 15 by weight fraction of the total solids of the surface layer.
% By weight of an electrophotographic photosensitive member, and
An apparatus unit and an electrophotographic apparatus having the same.

Embedded image

The electrophotographic photoreceptor provided by the present invention comprises a lubricant and a bisphenol having a weight average molecular weight of 100,000 to 150,000.
Nol Z-type polycarbonate and represented by the above formula (1)
When used in combination with triarylamine , lubricating properties are imparted to the surface of the photoreceptor to prevent mechanical damage such as abrasion and scratches during cleaning, and to exhibit mold releasability and water repellency. And by using these materials together,
Improves lubricity and chemical durability, forms a photoreceptor and photoreceptor surface with a suitable balance, such as less than the conventional amount of shaving, appropriate shaving to prevent filming and fusing, and slipping We were able to. This allows
The durability was dramatically improved, and a high-quality image free from ground fog and image blur was obtained.

[0008] Representative lubricants used in the present invention include, for example, lubricating resin powders such as fluorine resin powder, polyolefin resin powder, silicone resin powder and the like, and carbon fluoride. Resin powder is preferred. Examples of the fluorine resin powder include ethylene tetrafluoride resin powder, ethylene trifluoride ethylene resin powder, ethylene hexafluoride propylene resin powder, vinyl fluoride resin powder, vinylidene fluoride resin powder, and fluorine resin. Ethylene dichloride resin powders and copolymers thereof, and the like, one or more of which are appropriately selected, and particularly preferred are tetrafluoroethylene resin powder and vinylidene fluoride resin powder. . Examples of the polyolefin resin powder include homopolymer resin powders such as polyethylene resin powder, polypropylene resin powder, polybutene resin powder, and polyhexene resin powder, ethylene-propylene copolymer, and ethylene-butene copolymer powder. Copolymer resin powders such as coalesce, terpolymers such as these and hexene, and polyolefin resin powders such as thermal denatured products thereof, and the like, and one or more of them are appropriately selected. However, polyethylene resin powder and polypropylene resin powder are particularly preferable. The molecular weight of the resin used for the lubricant and the particle size of the powder can be appropriately selected, and the particle size is particularly preferably 0.1 μm to 10 μm. In order to uniformly disperse these lubricants, a dispersant may be added to the binder resin.

When forming a photosensitive layer in which a lubricant is dispersed, a resin having a film-forming property is used as a binder in order to use a charge transporting substance having a low molecular weight that cannot form a film. As the binder resin, bisphenol Z-type polycarbonate is used because it has a certain degree of hardness alone and does not hinder carrier transport.
You .

[0010] The weight average molecular weight of these resins must be 100,000 to 150,000 in consideration of coatability.

The content of the lubricant dispersed in these binder resins depends on the weight of the total solid content of the surface layer containing the lubricant in view of the surface modification effect, light transmittance, carrier mobility and the like. The content is 2 to 15% by weight .

[0012] The photosensitive layer of the electrophotographic photosensitive member of the present invention is a multilayer having a charge transport layer containing a charge transport material and the charge generating layer containing a charge <br/> generating material, the conductive support, This is a type having a charge generation layer and a charge transport layer in this order .

As the material of the support of the electrophotographic photosensitive member of the present invention, aluminum, aluminum alloy, copper, zinc,
Examples include stainless steel, titanium, nickel, indium, gold and platinum. In addition, plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, and the like) formed by coating these metals and alloys by a vacuum evaporation method, and the above-described plastics with conductive particles together with an appropriate binder resin, A support coated on a metal or alloy support, a support in which conductive particles are impregnated in plastic or paper, or the like can be used. Examples of the shape of the support include a drum shape and a belt shape, and it is preferable to make the shape most suitable for the applied electrophotographic photosensitive member.

As the conductive particles, those having conductivity per se, for example, metal powder (for example, aluminum, copper, nickel and silver), metal single fiber, carbon fiber, conductive powder [for example, carbon Black, titanium black, graphite, metal oxides and metal sulfides (eg, antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, potassium titanate, barium titanate, magnesium titanate, barium sulfate, zinc sulfide, sulfide Copper, magnesium oxide, aluminum oxide, etc.) and their metal oxides and metal sulfides that have been surface treated with a conductive substance, those that have been surface treated with a silane coupling agent or titanium coupling agent, and those that have been reduced. And the like.

An undercoat layer having a barrier function and an adhesive function may be provided between the conductive layer and the photosensitive layer. The undercoat layer is made of casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon alkoxymethylated nylon, etc.), polyurethane, gelatin, It can be formed of atuminium oxide, polyamic acid, polyimide, or the like.

The thickness of the undercoat layer is preferably 0.1 to 50 μm.
m, more preferably 0.3 to 20 μm. The charge generating layer is a pigment such as monoazo, bisazo and trisazo;
Phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine; Indigo pigments such as indigo and thioindigo; Polycyclic quinone pigments such as anthantrone and pyrenequinone; Perylene pigments such as perylene anhydride and perylene imide; A charge generating substance such as pyrylium and thiapyrylium salts; and a triphenylmethane-based dye, using a suitable solvent to form a binder resin, for example, polyvinyl acetal;
It can be formed by applying and drying a solution dispersed in a resin such as polystyrene, polyester, polyvinyl acetate, methacrylic resin, acrylic resin, polyvinylpyrroliton and cellulose resin. The thickness of the charge generation layer is usually preferably 5 μm or less,
In particular, the thickness is preferably 0.05 to 2 μm.

The charge transport layer is formed by applying a solution of a charge transport material of the following formula (1) to a solution of a resin having film forming properties and drying the solution.

Embedded image

[0018]

[0019]

[0020]

Examples of the method for applying the various layers include a dip coating method, a spray coating method, a beam coating method, a spinner coating method, a roller coating method, a Meyer bar coating method and a blade coating method.

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

The electrophotographic photoreceptor of the present invention can be applied to general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers.
Furthermore, the present invention can be widely applied to devices such as display, recording, light printing, plate making, and facsimile to which electrophotographic technology is applied.

FIG. 1 schematically shows an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is driven to rotate around an axis 1a in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then, in an exposure section 3, a light image exposure L (slit exposure) by an image exposure means (not shown).・ Laser beam scanning exposure). As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then developed with toner by developing means 4, and the developed toner image is synchronized with the rotation of photoconductor 1 between photoconductor 1 and transfer means 5 from a paper feeding unit (not shown). The transfer material 5 is sequentially transferred to the transferred and fed transfer material P.

The transfer material P which has undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing to be printed out as a copy outside the machine.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 6, and further subjected to a static elimination treatment by the pre-exposure means 7 to be used repeatedly for image formation. You.

As the uniform charging means 2 for the photosensitive member 1, a corona charging device is generally widely used. Transfer device 5
Also, corona transfer means are generally widely used. In the present invention, among the above-described components such as the photoconductor, the developing unit, and the cleaning unit, a plurality of components are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. May be. For example, a unit is formed by integrally supporting at least one of the charging unit, the developing unit, and the cleaning unit together with the photoreceptor, and the unit is detachably attached to the apparatus main body. It may be configured to be detachable.

In the case where the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L involves irradiating the photosensitive member with reflected light or transmitted light from the original, or reading the original with a sensor and converting it into a signal. In accordance with this signal, scanning of a laser beam, driving of an LED array, driving of a liquid crystal shutter array, and the like are performed to irradiate the photosensitive member with light.

When used as a facsimile printer, the light image exposure L is an exposure for printing received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The whole controller 11 is CP
It is controlled by U17. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 13. Data received from the partner station is sent to the printer 19 through the receiving circuit 12. Predetermined image data is stored in the image memory. The printer controller 18 is the printer 1
9 is controlled. 14 is a telephone.

The image received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, and then the CPU 17 performs a decoding process on the image information and sequentially processes the image memory 16 Is stored in And
When the image of at least one page is stored in the memory 16, the image of the page is recorded. The CPU 17 reads out one page of image information from the memory 16 and creates one page of image information which is decoded by the printer controller 18. When receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page. Note that C
The PU 17 is receiving the next page during recording by the printer 19. Image reception and recording are performed as described above.

[0040]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” indicates “parts by weight”. Example 1 An aluminum cylinder was used as a support, and a 5% methanol solution of a polyamide resin (trade name: Amilan CM-8000, manufactured by Toray) was applied by a dipping method, and dried at 90 ° C. for 10 minutes to form a film. Formed an undercoat layer of 0.5 μm.

Next, the following equation

[0042]

Embedded image Is added to 5 parts of a bisazo pigment represented by
And dispersed with a sand mill for 20 hours. 1. Butyral resin (trade name: BLS, manufactured by Sekisui Chemical Co., Ltd.)
A solution prepared by dissolving 5 parts in 20 parts of tetrahydrofuran is added.
Further dispersed for 2 hours. Cyclohexanone 1
A solution diluted by adding 00 parts and 100 parts of tetrahydrofuran was applied on the previously formed undercoat layer, and dried at 80 ° C. for 10 minutes to form a 0.15 μm-thick charge generation layer.

Next, a polytetrafluoroethylene resin powder (trade name: Lubron L-2,
Daikin Industries, Ltd.) and polypropylene resin powder and polyethylene resin powder;

[0044]

Embedded image A photoreceptor was prepared using a triarylamine represented by the following formula and a bisphenol Z-type polycarbonate resin (weight average molecular weight 120,000, manufactured by Teijin Chemicals Ltd.) as a binder resin.

First, 20 parts of the above-mentioned polycarbonate resin and 20 parts of the above-mentioned charge transporting substance were dissolved in 100 parts of chlorobenzene, and 6 parts of polytetrafluoroethylene resin powder as a lubricant was added thereto. After dispersion, 20 parts of dichloroethane was added to prepare a charge transport layer coating solution. This solution was applied on the charge generation layer,
The resultant was dried with hot air at 00 ° C. for 90 minutes to form a charge transport layer having a thickness of 20 μm. This is a photoconductor. Further, photoconductors were prepared in the same manner as above except that the lubricant was changed to polypropylene resin powder and polyethylene resin powder, and photoconductors 2 and 3 were obtained, respectively.

The photoreceptor thus prepared is inserted into the blade (the length of time when the blade is pressed against the photoreceptor and bent).
It was mounted on a Canon copier NP-3525 modified so as to have a 1.0 mm sponge roller relative speed of 106%, and was subjected to image evaluation and durability evaluation.

The photosensitive members 1 to 3 did not suffer from image blur and background fog even after 200,000 sheets of durability, and high quality copies were obtained. At this time, the amount of reduction in the thickness of the photoreceptor was 1.8 μm.

Further, the photosensitive members 1 to 3 are heated at a high temperature and a high humidity (3
The endurance of 10,000 sheets was carried out at 2.5 ° C. and 90% RH), but no image deletion occurred and a high quality image was obtained.

Comparative Example 1 High molecular weight polycarbonate resin of Example 1 Polycarbonate resin having a weight average molecular weight of 55,000 (manufactured by Teijin Chemicals Ltd.)
Comparative Photoreceptor 1 was prepared in the same manner as in Example 1 except that polytetrafluoroethylene resin powder was used as a lubricant, and image evaluation and durability evaluation were performed.

As a result, no image blurring occurred on 100,000 sheets of the comparative photoreceptor 1, but background fogging occurred. At this time, the amount of decrease in the thickness of the photoreceptor was 6.0 μm.

Example 2 The same as Example 1 except that polyvinylidene fluoride resin powder (trade name: Kaina K-301F, manufactured by Penwald) was used instead of the polytetrafluoroethylene resin powder as the fluorine resin powder. The photoreceptor 4 was prepared by various methods, and image evaluation and durability evaluation were performed.

The photosensitive member 4 did not suffer from image blur and background fog even after 200,000 sheets of durability, and a high quality copy was obtained. At this time, the amount of reduction in the thickness of the photoreceptor was 1.5 μm.

Comparative Example 2 10 parts of the charge transport material of Example 1 and a bisphenol Z type polycarbonate resin (weight average molecular weight 55,000,
10 parts were dissolved in 70 parts of dichloromethane, and this solution was applied on a drum coated with the above-mentioned charge generating layer, and dried with hot air at 100 ° C. for 90 minutes to form a film having a thickness of 20 μm.
m, and a comparative photoreceptor 2 was prepared. Then, the above-mentioned modified Canon copying machine NP-35 was used.
25, and a durability test was performed in a high-temperature and high-humidity environment (32.5 ° C., 90% RH).

Then, since the photosensitive layer has no releasability, it is difficult to remove paper powder and the like adhering to the surface.
Image blur occurred from about 0000 sheets.

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

A photoreceptor was prepared in the same manner as in Example 1 except that carbon fluoride (manufactured by Daikin Industries) was used instead of polytetrafluoroethylene resin powder as a lubricant. This photoreceptor is referred to as photoreceptor 9, and a silicone resin powder (XC-99-5) is used instead of the lubricant.
01, except using Toshiba Silicone) photoreceptors were prepared in the same manner as in Example 1 and the photosensitive member 10.
These photosensitive members were evaluated for image and durability in the same manner as in Example 1.

The photosensitive member 9 did not cause image blur and background fog even after 200,000 sheets of durability, and a high quality copy was obtained. In this case, the amount of reduction in the thickness of the photosensitive member was 2.3 μm.

Further, the photosensitive member 9 is heated to a high temperature and a high humidity (32.5
(100.degree. C., 90% RH), the endurance of 10,000 sheets was performed, but no fog occurred on the image run-off area, and a high-quality image was obtained.

[0065]

According to the present invention, a lubricant, a high molecular weight polycarbonate and a specific triarylamide are added to the photoreceptor surface layer .
By adding the emissions, improve mechanical durability such as abrasion and scratches on the surface, it may be formed by continuing the cleaning of good high quality image with no free hand image blurring and fogging of toner adhesion An electrophotographic photoreceptor can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram illustrating an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of the present invention 1a shaft 2 Charging means 3 Exposure unit 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means L Optical image exposure P Transfer material 10 Image reading unit 11 Controller 12 Receiving circuit 13 Transmission circuit 14 Telephone 15 Line 16 Image memory 17 CPU 18 Printer controller 19 Printer

Claims (4)

(57) [Claims] An electrophotographic photosensitive member and an electrophotographic photosensitive member are arranged in contact with the photosensitive member.
Cleaning of sponge roller and blade
Electrophotographic photosensitive member for an electrophotographic apparatus having
The charge generation layer and the charge transport layer on the conductive support.
Has in order, in the electrophotographic photoreceptor charge transport layer is the surface layer, the charge transport layer is a lubricant, a weight average molecular weight 10
It contains 10,000 to 150,000 bisphenol Z-type polycarbonate resin and triarylamine represented by the following formula (1), and the content of the lubricant is a weight fraction of the total solids of the surface layer. An electrophotographic photoreceptor, wherein the content is 2 to 15% by weight. Embedded image 2. The electrophotographic photoreceptor according to claim 1 , wherein the lubricant is a fluororesin powder, a polyethylene resin powder or a polypropylene resin powder. 3. The electrophotographic photoreceptor according to claim 1 or 2 , means for forming an electrostatic latent image on the photoreceptor, means for developing the formed electrostatic latent image, and transferring the developed image to a transfer material An electrophotographic apparatus, comprising: 4. The method of claim 1 or 2, an electrophotographic photosensitive member according to, and charging means, at least one selected from the group consisting of the developing means and cleaning means constituted by combining together, electrophotographic apparatus An apparatus unit which is detachable from a main body.