JPH0534958A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitive body having high durability and causing no image defects by inhibiting the cracking of a sensitive body by coating with a protective layer. CONSTITUTION:In this electrophotographic sensitive body with a photosensitive layer and a protective layer on the electric conductive substrate, the protective layer contains polyester resin and photosetting resin and the photosensitive layer contains a triarylamine compd. having <=150 deg.C m.p. represented by the formula as an electric charge transferring material. In the formula, each of Ar<1>-Ar<3> is an arom. cyclic or heterocyclic group which may have a substituent. Since excellent durability is ensured and the photosensitive layer does not crack, stable high-grade images free from image defects and unevenness can be formed even after repeated use as well as in the early stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, particularly an electrophotographic photoreceptor having a surface protective layer.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is required to have required sensitivity, electric characteristics and optical characteristics according to an electrophotographic process to be applied. Furthermore, in the case of a photoreceptor that is repeatedly used, the surface layer of the photoreceptor, that is, the layer that is most isolated from the support, has electrical and mechanical properties such as corona charging, toner development, transfer to paper or cleaning treatment. Since external force is directly applied, durability against them is required. Specifically, it is required to have durability against abrasion and scratches on the surface due to rubbing, and deterioration of the surface due to ozone generated during corona charging. On the other hand, there is a problem that the toner adheres to the surface layer due to repeated development and cleaning of the toner, and it is required to improve the cleaning property of the surface layer.

In order to satisfy the characteristics required for the surface layer as described above, attempts have been made to provide a surface protective layer containing a resin as a main component. For example, as disclosed in JP-A-56-42863 and JP-A-53-103741, a protective layer containing a curable resin as a main component is used to improve hardness and wear resistance. There is. However, when these curable resins are used as the surface protective layer, particularly in an organic photoreceptor containing a resin as a main component, cracking occurs in the protective layer or the photosensitive layer due to shrinkage during curing of the curable resin, particularly in the lower photosensitive layer. However, there is still a problem that the protective layer using these curable resins is not practically used in the organic photoconductor.

Recently, a polycarbonate resin has been used as a binder (binder) for the surface layer as a resin satisfying the above-mentioned various requirements. However, its durability is 50,000 to 100,000 sheets, which is more than the number of sheets of acrylic resin to be passed from 1,000 to 10,000 sheets before that, but Se or a-Si of an inorganic photoreceptor is used. The number did not reach 300,000 to 1 million.

Therefore, many studies have been conducted to provide a protective layer in which a normal resin or a fluorine-containing resin is added to a normal resin. However, the provision of the layer in which the charge does not move has an adverse effect that the residual potential (Vr) is increased and the sensitivity is lowered due to durable use, and the film thickness of the protective layer is set to 2 in order to eliminate these adverse effects. When the thickness was reduced to about 3 μm, the normal resin was worn out by the durable use and the durability was not improved. Furthermore, in the case of a protective layer obtained by adding polytetrafluoroethylene (hereinafter sometimes abbreviated as "PTFE") to an ordinary resin, the surface of the photoconductor is gradually scraped as the photoconductor is used for a long time, so that the PTFE is always fresh. Since good cleaning characteristics are maintained by exposing the toner to the surface of the photoreceptor, it is necessary to use a resin having a low hardness as a normal resin (binder). However, when a low hardness binder is used, the cleaning properties are good and the durability of the binder layer is increased, but due to the low hardness of the film, scratches due to rubbing with a cleaning blade and cracking due to impact (peeling of the film) occur. It's easier. Furthermore, the leading edge or the trailing edge of the transfer paper comes into contact with the photoconductor, causing scratches on the photoconductor, which causes image defects such as black streaks. Further, as with a normal protective layer, there is a problem that the residual potential increases and the sensitivity decreases due to durable use.

Further, when a high hardness resin is used to improve wear resistance, the coefficient of frictional resistance becomes several orders of magnitude higher than that of polycarbonate and the like, which makes it difficult to obtain good cleaning characteristics.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to provide an electrophotographic photosensitive member which meets the above-mentioned requirements.
An object of the present invention is to provide an electrophotographic photosensitive member which suppresses cracking of the photosensitive member due to coating of a protective layer, has high durability, and is free from image defects.

[0008]

According to the present invention, in an electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, the protective layer contains a polyester resin and a photocurable resin, and the photosensitive layer is An electrophotographic photoreceptor containing a triarylamine compound represented by the following structural formula (1) and having a melting point of 150 ° C. or less as a charge transport material to be used,

[0009]

[Chemical 2] [Wherein Ar ¹ , Ar ² and Ar ³ each represent an aromatic ring group or a heterocyclic group which may have a substituent].

The details of the contents of the present invention will be described below.

The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a structure in which a photosensitive layer and a protective layer are laminated in this order on a conductive support. First, the protective layer will be described below.

Although the protective layer comprising the polyester resin and the photocurable resin according to the present invention is remarkably excellent in abrasion resistance, it has a small frictional resistance and is therefore extremely useful as a surface protective layer for an electrophotographic photoreceptor. This is different from the conventional single type of resin or copolymer resin, and the characteristics of the respective resin components act synergistically due to the mixture of the polyester resin and the photo-curing resin, and as a result, an effect that has not existed in the past has been developed. I think that. Further, since the protective layer is extremely tough, it can be thinned. The thickness of the protective layer is preferably 3 μm or less, more preferably 0.1 to 2 μm.

As the polyester resin, it is desirable to use a polyester resin that can sufficiently reduce the fluctuation of mechanical properties due to temperature and humidity and that has good lubricity for a cleaning blade.
Therefore, the Tg of polyester resin is 40 ° C.
The above is preferable, and specific examples thereof include a polycondensate of terephthalic acid and ethylene glycol, that is, a polyethylene terephthalate resin, and a polycondensate of terephthalic acid and butylene glycol, that is, a polybutylene terephthalate resin. The molecular weight of the polyester resin is preferably in the range of 1,000 to 300,000 in terms of weight average molecular weight, and in consideration of solubility in a solvent and viscosity of the solution, the weight average molecular weight is in the range of 1,000 to 200,000. The range is more preferable. As the photo-curable resin, various known ones can be used, but preferably epoxy resins, specifically, those having bisphenol A as the central skeleton, those having resorcin as the central skeleton, and bisphenol F as the central skeleton. Examples thereof include those having a skeleton, those having a phenol novolac resin as its central skeleton, and those having polyalcohol or polyglycol as its central skeleton.

To form the protective layer, first, a coating solution containing a polyester resin, a photocurable resin and a polymerization initiator is applied by dip coating, spray coating, beam coating or the like. The solvent preferably has a boiling point of 50 ° C. or higher in consideration of film-forming properties,
Specific examples include solvents such as nitrobenzene; phenols such as phenol, cresol, m-cresol chlorophenol, and phenol tetrachloroethane; polyhalogenated alcohols such as hexafluoroisopropanol, and mixtures thereof. Next, the coating film is cured by a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, an EB irradiation device, or the like.

As described above, a very good film was obtained as the protective layer itself. However, when this film is coated on a normal photosensitive layer and photocured, a new problem arises that cracks occur in the photosensitive layer or the protective layer as described above.
Although the detailed mechanism of cracking of the photoreceptor due to the coating and curing of the protective layer is currently unknown, it can be easily inferred that the shrinkage of the film during curing of the protective layer is one of the causes.

Then, as a result of various studies, the inventors have found that the structure and the melting point of the charge transport material used in the photosensitive layer are strongly related to the occurrence of cracks in the photoreceptor. Furthermore, when a compound which is a triarylamine compound represented by the following structural formula (1) and has a melting point of 150 ° C. or lower is used as a charge transport material, a protective layer containing the polyester resin and the photocurable resin is used. It was discovered that even when used, the photoreceptor did not crack at all, and by using this, it became possible to fabricate a highly durable photoreceptor without cracking. Therefore, in the present invention, a compound which is a triarylamine compound represented by the following structural formula (1) and has a melting point of 150 ° C. or lower is used as a charge transport material to form a photosensitive layer.

[0017]

[Chemical 3] In the structural formula [1], Ar ¹ , Ar ² and Ar ³ are each an aromatic ring group such as phenyl, naphthyl, anthryl, pyrenyl, fluorenyl, phenanthryl, 9,10-dihydrophenanthryl, fluorenonyl, or pyridyl, quinolyl, Heterocyclic groups such as dibenzothienyl, dibenzofuryl, N-methylcarbazolyl, N-ethylcarbazolyl and N-tolylcarbazolyl are shown.

The aromatic ring group or the heterocyclic group of Ar ¹ , Ar ² and Ar ³ may have a substituent, and the substituent which may be substituted is alkyl such as methyl, ethyl, propyl and butyl. Groups, aralkyl groups such as benzyl, phenethyl and naphthylmethyl, alkoxy groups such as methoxy, ethoxy and propoxy, aryloxy groups such as phenoxy and naphthoxy, halogen atoms such as fluorine, chlorine, bromine and iodine, fragrances such as phenyl and biphenyl. Cyclic groups, diarylamino groups such as diphenylamino and ditolylamino, dialkylamino groups such as dimethylamino and diethylamino, diaralkylamino groups such as dibenzylamino and diphenethylamino, and alkylaralkylamino groups such as benzylmethylamino and benzylethylamino. , Nitro group, hydroxy group, etc. That.

Representative examples of the compound represented by the structural formula (1) are shown in Table 1. However, it is not limited to these compounds.

[0020]

[Chemical 4]

[0021]

[Chemical 5]

[0022]

[Chemical 6]

[0023]

[Chemical 7]

[0024]

[Chemical 8]

[0025]

[Chemical 9]

[0026]

[Chemical 10]

[0027]

[Chemical 11]

[0028]

[Chemical formula 12]

[0029]

[Chemical 13]

[0030]

[Chemical 14]

[0031]

[Chemical 15]

[0032]

[Chemical 16]

[0033]

[Chemical 17]

[0034]

[Chemical 18] The constitution of the photosensitive layer of the electrophotographic photosensitive member of the present invention is a single layer type containing both the charge generating material and the charge transporting material, or a laminated type in which the charge transporting layer and the charge generating layer are laminated on a conductive support. Is used.

The laminated photosensitive layer will be described below.
As the constitution of the laminated type photosensitive layer, there are one in which a charge generation layer and a charge transport layer are laminated in this order on a conductive support, and one in which a conductive support, a charge transport layer and a charge generation layer are laminated in this order.

The support used in the present invention may be any support as long as it has conductivity, for example, a metal such as aluminum, chromium, nickel, stainless steel, copper or zinc molded into a drum or sheet, A metal foil such as aluminum or copper laminated on a plastic film, aluminum, indium oxide, tin oxide, etc. deposited on a plastic film, or
Examples of the material include metal, plastic film, paper and the like, which are provided with a conductive layer by coating a conductive substance alone or with an appropriate binder resin.

As the conductive substance used for this conductive layer, metal powder such as aluminum, copper, nickel, silver, and the like,
Conductive metal oxides such as metal foil and metal fiber, antimony oxide, indium oxide, tin oxide, polypyrrole,
Examples thereof include polymer conductive materials such as polyaniline and polymer electrolytes, carbon black, graphite powder, organic and inorganic electrolytes, and conductive powders coated with these conductive substances on their surfaces.

The charge-transporting layer of the multi-layer type photoconductor used in the present invention is a triarylamine compound represented by the structural formula (1) and has a melting point of 150 ° C. or lower as a charge-transporting material. It is formed using a coating liquid dissolved in a resin having film-forming properties. Examples of the resin having such a film forming property include polyester, polycarbonate, polymethacrylic acid ester, and polystyrene. The thickness of the charge transport layer is 5 to 40 μm, preferably 10 to 30
μm.

The charge generating layer of the multi-layer type photoreceptor is an azo pigment such as Sudan red or Diane blue, a quinone pigment such as pyrene quinone or anthanthrone, a quinocyanine pigment,
Perylene pigment, indigo, indigo pigment such as thioindigo, azurenium salt pigment, copper phthalocyanine, charge generation material such as phthalocyanine pigment such as titanyl phthalocyanine resin of the present invention, or polyvinyl butyral,
It can be formed by dispersing it in a binder resin such as polystyrene, polyvinyl acetate, acrylic resin, cellulose acetate butyrate, or ethyl cellulose, and applying this dispersion liquid. The thickness of such a charge generation layer is 5 μm or less, preferably 0.05 to 2 μm.

Next, the single-layer type photosensitive layer will be described. The single-layer type photosensitive layer is obtained by coating the conductive support with a liquid obtained by dissolving and dispersing the binder resin, the charge generating material and the charge transporting material represented by the structural formula (1) used in the present invention. Formed. The thickness of the single-layer type photosensitive layer is 5 to 40 μm,
It is preferably 10 to 30 μm.

As described above, in the electrophotographic photoreceptor of the present invention, the protective layer has a polyester resin and a photocurable resin,
An electrophotographic photoreceptor comprising a photosensitive layer containing a triarylamine compound represented by the structural formula (1) as a charge transport material used in the photosensitive layer and having a melting point of 150 ° C. or lower.

Therefore, in the present invention, electrophotography which is excellent in durability, has no cracks on the photoconductor even when the protective layer is applied and is photocured, and which is free from image defects and gives high quality images. It is now possible to provide a photoconductor.

Further, in the present invention, since the photoreceptor is not deteriorated by being left under the charger, even after repeated durability,
It was possible to provide a photoreceptor having no image defects.

FIG. 1 shows a schematic structural example of a general transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention. In the figure, reference numeral 1 denotes a drum type photoconductor, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. The photosensitive member 1 receives uniform charging of a positive or negative predetermined potential on the peripheral surface of the photosensitive member 1 by the charging unit 2 during its rotation process, and then the optical image exposure L (slit exposure / laser) by the image exposing unit (not shown) in the exposure unit 3. 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 taken out by the transfer means 5 from a paper feed unit (not shown) between the photoconductor 1 and the transfer means 5 in synchronization with the rotation of the photoconductor 1. Are sequentially transferred onto the surface of the transfer material P that has been fed.
The transfer material P that has undergone 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 the image fixing and is a copy.
Is printed out of the machine as. After the image transfer, the surface of the photoconductor 1 is cleaned by the cleaning unit 6 to remove the residual toner after transfer, and is further discharged by the pre-exposure unit 7 to be repeatedly used 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. The electrophotographic apparatus is configured by integrally combining a plurality of components, such as the above-described photoconductor, developing unit, and cleaning unit, as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. May be. For example, the photoconductor 1 and the cleaning unit 6
May be integrated into one device unit, and may be detachably configured by using guide means such as a rail of the device body. At this time, the above apparatus unit may be provided with a charging unit and / or a developing unit. Light image exposure L
When the electrophotographic device is used as a copying machine or a printer, the reflected light or transmitted light from the manuscript, or the manuscript is read and converted into a signal, and the laser beam scans by this signal.
This is performed by driving the LED array, driving the liquid crystal shutter array, or the like.

When the electrophotographic photosensitive member of the present invention is used as a printer for a facsimile, the light image exposure L becomes an exposure for printing the received data. FIG. 2 is a block diagram showing an example of this case. The controller 11 controls the image reading unit 10 and the printer 19.
The entire controller 11 is controlled by the CPU 17. The read data from the image reading unit 10 is the transmission circuit 1
It is transmitted to the other station through 3. The data received from the partner station is sent to the printer 19 through the receiving circuit 12.
The image memory 16 stores predetermined image data. The printer controller 18 controls the printer 19. 14 is a telephone. The image information received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, then decoded by the CPU 17, and sequentially stored in the image memory 16. .. When the image information of at least one page is stored in the memory 16, the image recording of that page is performed. CPU1
7 reads one page of image information from the memory 16,
The decoded image information of one page is sent to the printer controller 18. The printer controller 18 is a CP
When receiving the image information of one page from U17, the printer 19 is controlled to record the image information of the page. The CPU 17 is receiving the next page during recording by the printer 19. As described above, the image is received and recorded.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in laser beam printers and C
RT printer, LED printer, liquid crystal printer,
It can be widely used in electrophotographic application fields such as laser plate making.

[0047]

EXAMPLES The present invention will be described below with reference to examples. In the examples, “part” means “part by weight” and “%” means “% by weight”.

Example 1 10 parts of alcohol-soluble copolymerized nylon resin (average molecular weight 29000) and 30 parts of methoxymethylated 6 nylon resin (average molecular weight 32000) were dissolved in a mixed solvent of 260 parts of methanol and 40 parts of butanol. , 1 by dipping and applying this formulation on a glass substrate
An undercoat layer having a thickness of μm was provided.

Next, as a charge transport material, 10 parts of the exemplified triarylamine compound and 10 parts of a polycarbonate (weight average molecular weight of 46000) were added to 20 parts of dichloromethane.
Parts, dissolved in a mixed solvent of 40 parts of monochlorobenzene,
This solution was applied onto the undercoat layer by dip coating and dried at 120 ° C. for 60 minutes to form a charge transport layer having a film thickness of 18 μm.

Next, structural formula (2)

[0051]

[Chemical 19] 4 parts of disazo pigment, 2 parts of polyvinyl butyral (butyralization rate 68%, weight average molecular weight 24000) and 34 parts of cyclohexanone were dispersed for 12 hours in a sand mill using φ1 mm glass beads, and then 60 parts of tetrahydrofuran (THF) was added. To prepare a dispersion liquid for the charge generation layer. This dispersion was spray-coated on the above charge transport layer and dried at 80 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.20 μm to obtain a laminated photosensitive layer.

Then, a solution for forming a surface layer having the following composition was applied onto the charge generation layer by dip coating, dried at 70 ° C. for 30 minutes, and irradiated with a high pressure mercury lamp (80 W) for 10 seconds to cure the solution. After that, heat treatment is performed at 75 ° C for 1 hour to obtain a film thickness of 5μ.
m surface protection layer was formed.

Polyethylene terephthalate resin 80 parts Epoxy resin 20 parts Diphenyliodonium hexafluorophosphorus salt 1.1 parts Hexafluoroisopropanol 900 parts The surface of the obtained surface protective layer was a uniform and even surface.

Next, the generation of cracks was observed with a transmission microscope while irradiating the photoreceptors with light from the back surface at an angle of 15 °. The results are shown in Table 2. The evaluation was judged by the condition of cracks in the entire field of view with the 10x lens of the microscope, and
It was ranked by Δ and ×. ◯ has no cracks. Δ is relatively small (1 cm or less) and has 5 or less cracks. × indicates that the number of cracks is Δ or more or is larger than Δ.

[0055]

[Table 1] As shown in Table 1, the occurrence of cracks on the photoconductor becomes milder as the melting point of the charge transport material decreases, and does not occur at 150 ° C. or lower.

(Example 2) Conductive titanium oxide powder 50 coated with tin oxide containing 10% antimony oxide
Parts, 25 parts of phenolic resin, 20 parts of methyl cellosolve,
5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average molecular weight 3
000) 0.002 part was dispersed for 2 hours by a sand mill using φ1 mm glass beads to prepare a conductive layer coating material. Aluminum cylinder (φ30mm × 260m
m) was coated with the above coating by dip coating and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 20 μm.

Next, after forming an undercoat layer in the same manner as in Example 1, the above-mentioned triarylamine compound No. 1 was used as a charge transport material. A photosensitive layer was formed in the same manner as in Example 1 except that No. 18 was used. Next, a protective layer was formed in the same manner as in Example 1 except that photocuring was performed by irradiating for 15 seconds while rotating the drum with a high pressure mercury lamp (80 W).
A photoconductor was prepared.

The electrophotographic photosensitive member thus manufactured was mounted on a copier of a positive development image system in which a charging-exposure-developing-transfer-cleaning process was repeated in a cycle of 1.5 seconds, and electrophotographic characteristics were obtained under normal temperature and normal humidity. The evaluation was repeated, and the image forming durability was repeated 10,000 times. The results are shown in Table 3. As shown in Table 3, the sensitivity and the residual potential are the same as those of the photoconductor without the protective layer of Comparative Example 1, and a stable image in which image deterioration such as unevenness and black bands (black band-shaped image defects) does not occur I was able to get

(Examples 3 to 5) The charge transporting material in the photosensitive layer of Example 2 was used as the exemplified triarylamine compound N.
o. A photoconductor was prepared and evaluated in the same manner as in Example 2 except that 4,30,38 were used. The results are shown in Table 3.

Example 6 The charge transporting material in the photosensitive layer of Example 2 was the above-mentioned triarylamine compound No. 17
Instead of the polyester resin in the protective layer was replaced with a polytetramethylene terephthalate resin, a photoconductor was prepared and evaluated in the same manner as in Example 2. The results are shown in Table 3.

Example 7 The charge transporting material in the photosensitive layer of Example 2 was used as the above-mentioned triarylamine compound No. 19
Instead of the polyester resin in the protective layer was replaced with a polycondensate of terephthalic acid and cyclohexanedimethyl alcohol, a photoreceptor was prepared and evaluated in the same manner as in Example 2. The results are shown in Table 3.

Example 8 A conductive layer and an undercoat layer were provided on an aluminum cylinder in the same manner as in Example 2.
Next, structural formula (3)

[0063]

[Chemical 20] 4 parts of disazo pigment, 2 parts of polyvinyl benzal (80% benzalization rate, weight average molecular weight of 11,000), and 30 parts of cyclohexanone were dispersed for 20 hours in a sand mill using φ1 mm glass beads, and then 60 parts of methyl ethyl ketone was added. A dispersion liquid for the charge generation layer was prepared.
This dispersion is spray coated on the undercoat layer at 80 ° C.
And dried for 15 minutes to form a charge generation layer having a film thickness of 0.10 μm.

Next, the exemplified triarylamine compound No. 10 parts of the charge transport material of 8 and 10 parts of polycarbonate (weight average molecular weight 25,000) are dissolved in a mixed solvent of 20 parts of dichloromethane and 40 parts of monochlorobenzene, and this solution is dip-coated on the charge generation layer at 120 ° C.
And dried for 60 minutes to form a charge transport layer having a film thickness of 15 μm.

A protective layer similar to that of Example 2 was provided on the charge transport layer to obtain an electrophotographic photosensitive member. The electrophotographic photosensitive member manufactured in this manner was attached to a reversal development type laser printer in which the process of charging-laser exposure-developing-transfer-cleaning is repeated in a cycle of 1.5 seconds, and the electrophotographic characteristic The evaluation was carried out, and the image was repeatedly reproduced for 10,000 times. The results are shown in Table 3.

Example 9 An electrophotographic photosensitive member exactly the same as in Example 8 was prepared. This photoreceptor was evaluated in the same manner as in Example 8 except that the charging polarity was opposite.
The results are shown in Table 3.

(Examples 10 to 12) Photosensitive members were prepared and evaluated in the same manner as in Example 2 except that the charge transporting material in the photosensitive layer was changed to the composition shown in Table 2 below. went. The results are shown in Table 3.

[0068]

[Table 2] (Comparative Example 1) A photoconductor was prepared in the same manner as in Example 2 except that the protective layer was not formed in Example 2, and evaluated in the same manner as in Example 2. As a result, as shown in Table 3, the electrophotographic characteristics were good at the initial stage, but after the durability test, the charge generation layer on the surface was scraped after 300 sheets, and it was difficult to obtain a good image.

(Comparative Examples 2 to 4) In Example 2, the charge transporting materials in the photosensitive layer were each the above-mentioned triarylamine compound No. A photoreceptor was prepared and evaluated in the same manner as in Example 2 except that 53, 59 and 72 were used. The results are shown in Table 3.
Shown in.

[0070]

[Table 3]

[0071]

The electrophotographic photosensitive member of the present invention has a structure in which a photosensitive layer and a protective layer are laminated in this order, the protective layer is made of polyester resin and photocurable resin, and the structural formula is used as a charge transport material of the photosensitive layer. It contains a triarylamine compound represented by (1) and having a melting point of 150 ° C. or lower. As a result, a protective layer with high durability can be formed without cracks in the photosensitive layer, and a stable, high-quality image with no image defects or image unevenness can be provided from the initial stage to repeated durability. Made the body possible.

[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 Image holding member 2 Charging means 3 Exposure part 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shin Nagahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shoji Amemiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kiyoshi Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Innovator Naoto Fujimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, wherein the protective layer contains a polyester resin and a photocurable resin, and a charge transporting material used for the photosensitive layer has the following structural formula: An electrophotographic photoreceptor containing a triarylamine compound represented by (1) and having a melting point of 150 ° C. or less, [In the formula, Ar ¹ , Ar ² and Ar ³ each represent an aromatic ring group or a heterocyclic group which may have a substituent]. 2. The electrophotographic photosensitive member according to claim 1, wherein the photocurable resin is a photocurable epoxy resin. 3. The electrophotographic photosensitive member according to claim 1, wherein the polyester resin is a polyalkylene terephthalate resin. 4. The polyester resin 10 is used as the photocurable resin.
The electrophotographic photosensitive member according to claim 1, wherein the content is 3 to 80 parts by weight with respect to 0 parts by weight. 5. An electrophotographic apparatus provided with the electrophotographic photosensitive member according to claim 1. 6. A facsimile comprising the electrophotographic photosensitive member according to claim 1 and having a receiving means for receiving image information from a remote terminal.