JPH05265241A - Electrophotographic photoreceptor, electrophotographic apparatus and facsimile equipped with the electrophotographic photoreceptor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an electrophotographic photosensitive member excellent in durability by preventing foreign matters from adhering by improving slipperiness, abrasion resistance and releasability at the initial stage and after endurance. [Constitution] In an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer is a fluorinated carbon.
An electrophotographic photosensitive member characterized by containing bon and a compound represented by the following structural formula. In the formula, n and m are integers of 8 or more.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an electrophotographic apparatus equipped with the electrophotographic photosensitive member, and a facsimile.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as zinc oxide, selenium and cadmium sulfide have been known as photoconductive materials used for electrophotographic photoreceptors. Organic polyvinylcarbazole, phthalocyanine, azo pigments, etc. have high productivity,
It has been widely used although its advantages such as pollution-free have been noticed, and it has a drawback that it is inferior in photoconductive characteristics and durability. Recently, new materials are being proposed in which these drawbacks have been improved, and in particular, the photoconductive characteristics are surpassing those of inorganic materials.

The electrophotographic photosensitive member is repeatedly subjected to actions such as charging, exposure, development, transfer, cleaning and charge removal in the electrophotographic process of a copying machine, a laser beam printer, etc. Durability is required.
In particular, wear resistance is the largest factor that determines the durable life.
In addition, releasability is also an important factor for deterioration caused by adhesion of various foreign matters.

On the other hand, the above-mentioned organic photoconductive material does not have a film-forming property by itself, so that it is generally formed with a binder resin. Therefore, it is no exaggeration to say that the wear resistance and the releasability are almost limited by the selection of the binder resin. However, the binder resin satisfying the photoconductive property is quite limited, and the abrasion resistance is far lower than that of the inorganic photoreceptor. Moreover, there is not enough releasability.

The electrophotographic process most concerned with abrasion resistance is cleaning. In recent years, with the development of fine particles of the developer, cleaning is required to have higher precision.
Further, it is advantageous to adopt blade cleaning in order to realize a simpler device configuration with the space saving of the device. Blade cleaning has a simple structure in which an elastic member such as a plate-shaped polyurethane is abutted on the photoconductor in the direction of the generatrix. However, a large frictional force is generated between the photoconductor and the blade, and Accelerates wear on the body and reduces durability. In order to deal with this, it is conceivable to impart strength to the photoconductor to endure the frictional force, or to impart slipperiness to the photoconductor in order to reduce the frictional force. In the former method, it is possible to use a curable binder resin. However, sufficient photoconductive properties cannot be obtained due to deterioration of the organic photoconductive material during curing. On the other hand, in the latter method, it is possible to add a lubricant to the photoconductor.

The releasability of the surface of the photoconductor has a great influence on its durability. In the electrophotographic process, foreign substances such as corona products generated at the time of charging, developers and their additives, and additives for transfer paper may adhere to the surface of the photoconductor. The adherence of foreign matter hinders normal image formation, thus rendering the photoconductor unusable. In order to prevent such foreign matter from adhering and to facilitate removal even if it adheres, it is necessary to improve the releasability of the surface of the photoconductor. Specifically, a method of adding a compound having a low surface free energy can be considered. In general, as a compound that imparts low surface energy and lubricity, a liquid or semi-solid silicon-based or fluorine-based polymer or oils, waxes,
Solid oxides, sulfides, fluorides, graphite and the like are known. Silicon-based and fluorine-based graft polymers and block polymers are known as liquid or semi-solid compounds, but these compounds are repeatedly used because they will bleed out on the surface of the photoreceptor after film formation. Sometimes clear
It is removed by the blade and the lubricity and releasability cannot be maintained. Known as solid compounds are polytetrafluoroethylene (PTFE), fine powder of fluorinated carbon, and the like. Since these solid fine particles are evenly distributed in the photoconductor by dispersion, the effect can be maintained even during repeated use. However, it is necessary to make uniform primary particle dispersion in order to prevent reflection and scattering of light during exposure by fine particles. In such a good dispersion state, since the fine particles are completely covered with the binder resin forming the photoconductor, the initial lubricity and releasability are not exhibited. Therefore, it is necessary to expose the fine particles by performing a surface polishing treatment or the like. However, polishing treatment is not preferable in terms of photoreceptor cost and yield, and in addition, a sufficient effect cannot always be obtained. Therefore, it has become necessary to develop a technique for exposing fine particles to the surface while maintaining a good dispersion state.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to improve the slip resistance and wear resistance by adding a compound having a low surface energy and a high lubricating property to an electrophotographic photoreceptor, and at the same time, to improve the releasability. It is an object of the present invention to provide an electrophotographic photosensitive member which is improved in its prevention of foreign matters and has excellent durability, and whose effect is maintained at the initial stage and after the durability. Another object of the present invention is to provide an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member.

[0008]

The present invention provides an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support,
The surface layer of the photosensitive layer comprises an electrophotographic photosensitive member characterized by containing carbon fluoride and a compound represented by the following structural formula. In the formula, n and m are integers of 8 or more.

Further, the present invention is an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the surface layer of the photosensitive layer contains carbon fluoride and a compound represented by the following structural formula. And an electrophotographic photoreceptor. In the formula, n is an integer of 8 or more.

The fine particles of carbon fluoride used in the present invention are ultrafine particles having a particle size of 0.1 μm or less and have excellent dispersibility. However, because of that, the binder resin is uniformly coated, and the initial lubricity and releasability cannot be exhibited by itself.

Therefore, in the present invention, the long-chain alkylamino acid compound represented by the above structural formula is added to assist the initial lubricity and releasability. This compound forms an assembly in which the molecular sequence is extremely regularly oriented by the amino acid residue and the long-chain alkyl group. The surface energy of the aggregate is extremely small because the hydrophobic methyl groups are densely arranged outside. Therefore, the cohesive energy between the aggregates is extremely small, and the lubricant has excellent performance. Further, since the surface energy is small, the releasability is excellent. Further, the humidity dependence is hardly affected by humidity because the hydrophobic methyl groups are densely arranged outside. The most important feature is that a part of this amino acid compound is exposed on the surface of the photoreceptor. The reason is not completely understood. However, dispersibility is not bad at all, and its specific gravity is relatively small, around 1,
When it is added to the photoconductor, it is considered that part of it floats on the surface. Therefore, sufficient lubricity and releasability can be exhibited even in the early stage photoreceptor.

The total amount of the carbon fluoride and the long-chain alkylamino acid added according to the present invention is 1 to 8 in the surface layer of the photoreceptor.
It is 0%, preferably 5 to 60%. At that time, a dispersant or a surfactant may be used. The blending ratio of the carbon fluoride and the long-chain alkyl amino acid is 1 to 300% by weight of the long-chain alkyl amino acid, preferably 10 to 15
It is 0%.

The photosensitive layer of the electrophotographic photosensitive member of the present invention has a single layer or a laminated structure. In the case of a single layer structure, generation and migration of photocarriers are carried out in the same layer, and a solid lubricant is also added here. In the case of a laminated structure, a charge generation layer that generates photocarriers and a charge transport layer that moves carriers are laminated. The surface layer may be formed by either the charge generation layer or the charge transport layer. In any case, the solid lubricant is added to form the surface layer. The single-layer photosensitive layer can have a thickness of 5 to 100 μm, preferably 10
-60 μm. 20 for charge generation materials and charge transport materials
-80%, preferably 30-70%. In the laminated photoreceptor, the thickness of the charge generation layer is 0.001 to 6
μm, preferably 0.01 to 2 μm. The amount of charge generating material is 10 to 100%, preferably 40 to 100%. The thickness of the charge transport layer is 5 to 100 μm, preferably 10 to 60 μm. The amount of charge transport material is 20-80
%, Preferably 30 to 70%.

Examples of the charge generating material include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium salt pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiapyrylium dyes, xanthene dyes, quinoneimine dyes. , Triphenylmethane dye, styryl dye, selenium,
Examples include selenium-tellurium, amorphous silicon, cadmium sulfide, and the like.

Examples of the charge transport material include pyrene compounds, carbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, tolphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds and stilbene compounds. Can be mentioned.

In the electrophotographic photoreceptor of the present invention, a protective layer may be laminated on the photosensitive layer, in which case a solid lubricant is added to the protective layer. The thickness of the protective layer can be 0.01 to 20 μm, preferably 0.1 to 10 μm. The protective layer may contain the above-mentioned charge generating material, charge transporting material, metal and its oxide, nitride, salt, alloy, and conductive material such as carbon.

Binder for forming the photosensitive layer and the protective layer
As the resin, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene,
Polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd Resin, butyral resin, etc. may be mentioned.

The conductive support is, for example, iron, copper, nickel, aluminum, titanium, antimony, indium,
Metals and alloys such as lead, zinc, gold, silver and stainless steel, oxides thereof, carbon and conductive resins can be used. The shapes include a cylindrical shape, a belt shape, and a sheet shape. The conductive material may be molded and processed, but may be applied as a paint or vapor-deposited.

In the present invention, an undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is mainly composed of a binder resin, but may contain the conductive material or the acceptor. As the binder resin, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetator.
Examples of the resin include nylon, nylon, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin and butyral resin.

The solid lubricant used in the present invention is
A material for forming the photosensitive layer is dispersed and mixed by using a sand mill, a roll mill, a ball mill, a homogenizer, an attritor, or the like.

A method such as vapor deposition or coating is used to manufacture the electrophotographic photosensitive member of the present invention. For coating, a bar coater, a knife coater, a roll coater, an attritor,
Spraying, dip coating, electrostatic coating, powder coating and the like are used.

The present invention also comprises an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention.

The present invention also comprises an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention and a facsimile having a receiving means for receiving image information from a remote terminal.

The electrophotographic photosensitive member of the present invention can be applied to general electrophotographic apparatus such as a copying machine, a laser printer, an LED printer, a liquid crystal shutter type printer, and the like. It can be widely applied to devices such as recording, light printing, plate making, and facsimile.

Next, an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member of the present invention will be described. Figure 1
The general construction of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention is shown in FIG. In the figure, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. In the course of its rotation, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging means 2, and then at the exposure section 3 an optical image exposure L (slit exposure Laser
Beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is rotated by the transfer means 5 from a paper feed unit (not shown) between the photosensitive body 1 and the transfer means 5. And is sequentially transferred onto the surface of the transfer material P that is fed in synchronization with the above. The transfer material P that has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where it is subjected to image fixing and printed out as a copy (copy). The surface of the photoreceptor 1 after the image transfer is transferred by the cleaning means 6 to the toner after transfer.
Is removed to obtain a clean surface, and the pre-exposure means 7 removes the charge to repeatedly use it for image formation. Photoconductor 1
A corona charging device is generally widely used as the uniform charging means 2. Also, as the transfer device 5, corona transfer means is generally widely used. As an electrophotographic apparatus, a plurality of constituent elements such as the photoconductor, the developing unit, and the cleaning unit described above are integrally combined as an apparatus unit, and the unit is detachably attached to the apparatus main body. It may be configured. For example, the photosensitive member 1 and the cleaning means 6 may be integrated into one device unit, and the device body may be detachably configured by using guide means such as a rail. At this time, the above-mentioned apparatus unit may be provided with a charging unit and / or a developing unit. In addition, the light image exposure L is applied to an electrophotographic apparatus such as a copying machine or a printer.
When used as a light source, the reflected light or transmitted light from the original is used, or when the original is read and converted into a signal, the laser beam is scanned by this signal, the light emitting diode array is driven, or the liquid crystal shutter is used. -It is performed by driving the array or the like. Further, when used as a printer of a facsimile, the light image exposure L becomes an exposure for printing the reception data.

FIG. 2 is a block diagram showing an example of this case. The controller 10 controls the image reading unit 9 and the printer 18. The entire controller 10 is C
It is controlled by the PU 16. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 12. The data received from the partner station is sent to the printer 18 through the receiving circuit 11. Predetermined image data is stored in the image memory. The printer controller 17 controls the printer 18. 13 is a telephone. Line 14
The image (image information from the remote terminal connected through the line) received from the demodulator is demodulated by the receiving circuit 11, and then the CPU 16 performs signal processing of the image information and sequentially stores it in the image memory 15. .. When at least one page of image is stored in the memory 15, the image of that page is stored. The CPU 16 reads out one page of image information from the memory 15 and sends the one page of image information signaled to the printer controller 17. Upon receiving the image information of one page from the CPU 16, the printer controller 17 controls the printer 18 to record the image information of the page. The CPU 16 is a printer
While recording by 18, the next page is being received.
The image is received and recorded as described above.

[0027]

【Example】

Example 1 10 parts of methoxymethylated nylon (parts by weight, the same applies hereinafter)
A solution in which 150 parts of isopropanol and 150 parts of isopropanol were mixed and dissolved was dip-coated on an aluminum cylinder having an outer diameter of 80 mm and a length of 358 mm to form an undercoat layer of 1 μm.

Next, 10 parts of a disazo pigment having the following structural formula,

[Chemical 1] Bisphenol A type polycarbonate (molecular weight 30,000) 5
Parts and 700 parts of cyclohexanone were dispersed by a sand mill, and this dispersion was dip-coated on the undercoat layer to form a charge generation layer having a thickness of 0.05 μm.

Next, 10 parts of a triphenylamine compound having the following structural formula,

[Chemical 2] Bisphenol A type polycarbonate (molecular weight of 25
Thousand) 10 parts, carbon fluoride (average primary particle size 0.03μ
m, composition (C ₁ F _m ) _n (1 = m = 1, n = integer) 3
Part, 1 part of the following long-chain alkylamino acid compound, (In the formula, n and m are integers of 8 or more) After mixing 150 parts of chlorobenzene and 100 parts of dichloromethane with a homogenizer, this coating solution is dip-coated on the charge generation layer to form a charge transport layer having a thickness of 20 μm. Formed. The prepared electrophotographic photosensitive member is referred to as Sample 1. Similarly, the electrophotographic photoconductor prepared by coating the photoconductor on a 50 .mu.m aluminum sheet and used as sample 2.

Comparative Example 1 Electrophotographic photosensitive members of Comparative Sample 1 and Comparative Sample 2 were prepared in the same manner as in Example 1 except that the carbon fluoride was not added.

Comparative Example 2 Electrophotographic photoreceptors of Comparative Sample 3 and Comparative Sample 4 were prepared in the same manner as in Example 1 except that the long-chain alkylamino acid compound was not added.

Example 2 The long-chain alkylamino acid compound used in Example 1 was the following long-chain alkylamino acid compound. (In the formula, n is an integer of 8 or more), except that the electrophotographic photosensitive members of Samples 3 and 4 were prepared in exactly the same manner as in Example 1. Sample 3 is an electrophotographic photosensitive member corresponding to sample 1 and sample 4 is an electrophotographic photosensitive member corresponding to sample 2.

Comparative Example 3 Electrophotographic photosensitive members of Comparative Sample 5 and Comparative Sample 6 were prepared in the same manner as in Example 2 except that the carbon fluoride was not added.

Comparative Example 4 Electrophotographic photoreceptors of Comparative Sample 7 and Comparative Sample 8 were prepared in the same manner as in Example 2 except that the long-chain alkylamino acid compound was not added.

Abrasion resistance test A taper type abrasion tester was used to compare sample 2 with comparative sample 2 and comparative sample 4 and sample 4 with comparative sample 6 and comparative sample 8 and weigh 500 g (2 50)
A 00 cycle wear test was performed. Regarding the weight reduction due to wear, Sample 2 and Sample 4 had only about half the wear as compared with Comparative Sample 2 and Comparative Sample 6, respectively. Comparative sample 4
And the comparative sample 8 had almost the same wear as the corresponding samples 2 and 4.

Sliding test Using a sliding tester manufactured by Haydon, the contact sliding property of the urethane cleaning blade material with Sample 1 and Sample 3, Comparative sample 1, Comparative sample 3, Comparative sample 5 and Comparative sample 7 Was measured. Calculated as relative slipperiness to standard Mylar film. The results show that Samples 1 and 3 showed better slip properties than standard Mylar, whereas
Comparative sample 1, Comparative sample 3, Comparative sample 5 and Comparative sample 7
Was less slippery than the standard Mylar.

Contact Angle Measurement When the contact angle of pure water was measured on each sample, comparative sample 1
And Comparative Sample 5 is 85 °, Comparative Sample 3 and Comparative Sample 7 are 89 °, whereas Sample 1 is 102 °, Sample 3
Was very large at 101 ° and was considered to have excellent releasability.

Durability of Actual Machine Each sample was mounted on a copying machine (trade name: NP4835, manufactured by Canon Inc.), and durability of 100,000 sheets was performed. Comparative sample 1 and comparative sample 5 became unusable due to low image density at 50,000 sheets, but sample 1 and sample 3, comparative sample 3 and comparative sample 7 were still good images even after 100,000 sheets. It was In addition, the amount of scraping in the actual machine was also sample 1, sample 3, and comparative sample 3.
In Comparative Sample 7, it was about 1/3 of that in Comparative Sample 1 and Comparative Sample 5.

Transfer Efficiency Each sample was mounted on a digital color copying machine (trade name: CLC300, manufactured by Canon Inc.), and the transfer efficiency when a magenta single color was measured. The measurement was calculated after measuring the densities of the toner on the transfer paper and the toner on the photoconductor at the time of image formation with a Macbeth densitometer. The transfer efficiency is 93% for sample 1 and sample 3.
Comparative sample 1 and comparative sample 5 were favorable.
Was 86%, and Comparative Samples 3 and 7 were 89%.

Example 3 30 parts of the same triphenylamine as in Example 1 and 60 bisphenol Z type polycarbonate (molecular weight 70,000)
Parts, 20 parts of the same fluorinated carbon as in Example 1, the same long-chain alkylamino acid compound 10 as in Example 1
Parts, chlorobenzene 1000 parts, dichloromethane 500
The parts were mixed by a homogenizer, and the prepared coating solution was applied on the same electrophotographic photosensitive member as in Comparative Sample 1 and Comparative Sample 2 to form a protective layer having a film thickness of 6 μm. The prepared electrophotographic photoconductors are referred to as Sample 5 and Sample 6. The results are shown in Table 1 below.
However, it showed excellent wear resistance and releasability.

Example 4 30 parts of the same triphenylamine as in Example 2 and 60 bisphenol Z type polycarbonate (molecular weight 70,000)
Parts, 20 parts of the same fluorinated carbon as in Example 2, the same long-chain alkylamino acid compound 10 as in Example 2
Parts, chlorobenzene 1000 parts, dichloromethane 500
The parts were mixed by a homogenizer, and the prepared coating solution was applied on the same electrophotographic photoreceptor as Comparative Sample 5 and Comparative Sample 6 to form a protective layer having a film thickness of 6 μm. The prepared electrophotographic photoconductors are referred to as Sample 7 and Sample 8. The results are shown in Table 1 below.
However, it showed excellent wear resistance and releasability.

Example 5 20 parts of the same triphenylamine as in Example 1 and 40 parts of bisphenol Z type polycarbonate (molecular weight 70,000)
Parts, 40 parts of the same fluorinated carbon as in Example 1, the same long-chain alkylamino acid compound 10 as in Example 1
Parts, chlorobenzene 1000 parts, dichloromethane 500
The parts were mixed by a homogenizer, and the prepared coating solution was applied on the same electrophotographic photosensitive member as in Comparative Sample 1 and Comparative Sample 2 to form a protective layer having a film thickness of 3 μm. The prepared electrophotographic photoconductors are referred to as Sample 9 and Sample 10. The results are shown in Table 1 below, and showed excellent wear resistance and releasability.

Example 6 20 parts of the same triphenylamine as in Example 2, 40 parts of bisphenol Z type polycarbonate (molecular weight 70,000)
Part, the same fluorinated carbon as in Example 2 40 parts, the same long-chain alkylamino acid compound 10 as in Example 2
Parts, chlorobenzene 1000 parts, dichloromethane 500
The parts were mixed by a homogenizer, and the prepared coating solution was applied on the same electrophotographic photoreceptor as Comparative Sample 5 and Comparative Sample 6 to form a protective layer having a film thickness of 3 μm. The prepared electrophotographic photoconductors are referred to as Sample 11 and Sample 12. The results are shown in Table 1 below, and showed excellent wear resistance and releasability.

[0044]

[Table 1]

[0045]

The electrophotographic photoconductor of the present invention improves the slipperiness and abrasion resistance at the initial stage and after the endurance by adding two kinds of solid lubricants to the photoconductor, and at the same time, improves the releasability. The improvement has the remarkable effect of preventing foreign matter from adhering and being excellent in durability. Further, in the electrophotographic apparatus and the facsimile equipped with the electrophotographic photosensitive member, the excellent effects of the electrophotographic photosensitive member are similarly exhibited.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Drum type photoconductor as an image carrier (electrophotographic photoconductor of the present invention) 2 Corona charging device 3 Exposure section 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means L Optical image exposure P Transfer material having received image transfer 9 Image reading unit 10 Controller 11 Reception circuit 12 Transmission circuit 13 Telephone 14 Line 15 Image memory 16 CPU 17 Printer controller 18 Printer-

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the surface layer of the photosensitive layer contains carbon fluoride and a compound represented by the following structural formula. Photoreceptor. In the formula, n and m are integers of 8 or more. 2. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the surface layer of the photosensitive layer contains carbon fluoride and a compound represented by the following structural formula. Photoreceptor. In the formula, n is an integer of 8 or more. 3. An electrophotographic apparatus provided with the electrophotographic photosensitive member according to claim 1. 4. A facsimile having an electrophotographic apparatus equipped with the electrophotographic photosensitive member according to claim 1 or 2, and means for receiving image information from a remote terminal. [0001]