JP3267526B2 - Electrophotographic photoreceptor, electrophotographic apparatus and process cartridge using the electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
The present invention relates to an electrophotographic apparatus, a process cartridge, and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is required to have required sensitivity, electrical characteristics and optical characteristics according to an applied electrophotographic process. Particularly, in the case of a photoreceptor that is repeatedly used, since electrical and mechanical external forces such as charging, image exposure, toner development, transfer to paper, and cleaning are directly applied to the photoreceptor surface, durability against them is reduced. Required. Specifically, durability is required against abrasion and scratches on the surface caused by rubbing of the surface of the photoconductor during transfer and cleaning, and deterioration of the photoconductor and electrical characteristics due to ozone generated during corona charging. Further, there is a problem that toner adheres to the surface of the photoreceptor due to repetition of toner development and cleaning, and good cleaning properties are also required.

Attempts have been made to provide a surface protective layer containing a resin as a main component on a photosensitive layer in order to satisfy the above-mentioned characteristics required for a photosensitive member. For example, JP-A-56-4
Japanese Patent Publication No. 2863 and Japanese Patent Application Laid-Open No. 53-103741 propose to improve hardness and wear resistance by using a protective layer containing a curable resin as a main component.

In order to obtain a better image, the protective layer of the photoreceptor is required to have not only characteristics such as high hardness and excellent abrasion resistance, but also an appropriate resistance of the protective layer itself. You. If the resistance of the protective layer is too high, by repeating the electrophotographic process such as charging-exposure, a so-called residual potential increases in which charges are accumulated in the protective layer, and the potential becomes unstable when the photoconductor is repeatedly used. , The image quality also becomes unstable. On the other hand, if the resistance is too low, the electrostatic latent image flows in the protective layer in the plane direction, which causes problems such as blurring and blurring of the image. In order to solve this problem, for example, Japanese Patent Laid-Open Publication No. Sho 57-30843 proposes to control the resistance of a protective layer by adding a metal oxide as conductive fine particles to the layer. On the other hand,
An appropriate resistance value of the protective layer for the electrophotographic photosensitive member is 10 ¹⁰ -1.
It is known to be 0 ¹⁵ Ω · cm.

[0005]

However, in the resistance value in the above range, the electric resistance of the protective layer tends to largely change due to a change in environment. In particular,
Under the high humidity, the resistance tends to decrease, and the above phenomenon causes a remarkable reduction in image quality. For example, a satisfactory protective layer for an electrophotographic photosensitive member has not yet been obtained.

Attempts to use a curable acrylic resin for a protective layer for a photoreceptor are disclosed in Japanese Patent Application Laid-Open Nos. 61-5253 and 1-178972. However, in these protective layers, since the acrylic resin has a polar group such as a carbonyl group that is easily affected by humidity,
The electrical resistance tends to greatly change due to changes in the environment, and particularly under high humidity, the resistance tends to decrease, and as a result, there has been a problem that image deletion occurs.

An attempt to use colloidal silica as a protective layer for a photoreceptor has been proposed in Japanese Patent Application Laid-Open No. 60-57847, etc. In these protective layers as well, colloidal silica contains a polar group such as a hydroxy group. To have
Similarly, it is susceptible to the influence of humidity, and also has a problem such as image deletion.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having excellent stability against environmental changes, high durability, low transfer memory and photo memory, and no accumulation of residual potential in repeated electrophotographic processes. An object of the present invention is to provide an electrophotographic apparatus and a process cartridge using a body.

[0009]

According to the present invention, there is provided an electrophotographic photosensitive member having at least a photosensitive layer and a protective layer on a support, wherein the protective layer is formed by condensation of a silyl acrylate compound with colloidal silica. It is formed by curing an object.

Further, the electrophotographic apparatus of the present invention comprises the above electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, and image exposure of the charged electrophotographic photosensitive member to form an electrostatic latent image. It has an image exposing means for forming and a developing means for developing the electrophotographic photosensitive member on which the electrostatic latent image is formed with toner.

Further, the process cartridge according to the present invention comprises:
The electrophotographic photoreceptor includes a charging member for charging the electrophotographic photoreceptor.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photoreceptor of the present invention has at least a photosensitive layer and a protective layer on a support, and the protective layer is formed by curing a condensate of a silyl acrylate compound and colloidal silica. It was done.

The silyl acrylate compound used in the present invention comprises at least one alkoxy group and at least one alkoxy group.
Those having one double bond are preferable, and are represented by, for example, the following general formula (1).

[0014]

[Outside 4] In the above formula (1), R ¹ represents an alkyl group, R ² represents an alkyl group, an alkoxy group or an aryl group, R ^3,
R ⁴ , R ⁵ and R ^{6 each} represent a hydrogen atom, an alkyl group, an alkoxy group or an aryl group, R ⁷ represents an alkylene group, m represents an integer of 0 to 2, and n represents an integer of 1 to 3 , P and q each represent an integer of 0 or more. However, 0 <m +
n ≦ 3.

The above-mentioned alkyl group, alkoxy group, aryl group and alkylene group may have a substituent.

The alkyl group for R ^{1 to} R ⁶ is preferably, for example, a group such as methyl, ethyl, propyl, butyl and the like.
As the aryl group for R ^{2 to} R ^6, a group such as phenyl and naphthyl is preferable. As the alkoxy group for R ^{2 to} R ⁶ , for example, a methoxy, ethoxy, propoxy or butoxy group is preferable. As the alkylene group for R ⁷ , groups such as methylene, ethylene, trimethylene and the like are preferable. Examples of the substituent which R ^{1 to} R ⁷ may have include an alkyl group such as methyl, ethyl, propyl and butyl, an alkoxy group such as methoxy, ethoxy, propoxy and butoxy, a fluorine atom, a chlorine atom and a bromine atom. Is preferred.

The number of R ¹ O— in the above (1) is preferably 2 or 3, and the number of carbon atoms of R ¹ O— is preferably 1 to 3.
The weight average molecular weight of the silyl acrylate compound is 200 to
500 is preferred.

Examples of the silyl acrylate used in the present invention are shown below, but are not limited thereto.

[0019]

[Outside 5]

[0020]

[Outside 6]

[0021]

[Outside 7]

[0022]

[Outside 8]

[0023]

[Outside 9]

As is well known, the colloidal silica used in the present invention can be formed by hydration of Si having a hydroxyl group on the surface.
It is a dispersion of O ₂ particles. In the present invention, the SiO ₂ particles of the colloidal silica preferably have a particle size of 1 nm or less and 1 μm or more.

The condensate of a silyl acrylate compound and colloidal silica is obtained by hydrolyzing silyl acrylate in the presence of aqueous colloidal silica and a water-miscible alcohol, or by adding aqueous colloidal silica to silyl acrylate hydrolyzed in alcoholic water. can get.

The compounding ratio of the silyl acrylate compound to the colloidal silica is preferably 5 to 20 times the weight ratio of the colloidal silica to the acrylic monomer.

The condensate thus obtained is a photocurable monomer obtained by modifying an acrylic monomer with a water-repellent siloxane structure and hydrophobic silica, and the protective layer obtained by curing the acrylic monomer has high water repellency. Since the hydroxyl group on the silica surface is condensed with the alkoxysilane, it is hardly affected by humidity. Further, the protective layer used in the present invention is very effective for improving the transfer memory of the electrophotographic photosensitive member.

The use of a hydrolysis product of colloidal silica and silyl acrylate as a coating material is disclosed in US Pat.
As described in P4455205, in the present invention, a condensate of a silyl acrylate compound and colloidal silica is used for a protective layer of an electrophotographic photosensitive member to complete an electrophotographic photosensitive member having a low transfer memory.

In curing the condensate of the silyl acrylate compound and colloidal silica, a photopolymerization initiator is used. The addition amount of the photopolymerization initiator is preferably from 0.1 to 40% by weight, particularly preferably from 0.5 to 20% by weight, based on the total weight of the condensate.

Preferred examples of the photopolymerization initiator are shown below, but are not limited thereto.

[0031]

[Outside 10]

When a polyfunctional acrylic monomer is added to the condensate used in the present invention and cured together, the resulting film is preferably denser. When a polyfunctional acrylic monomer is added, the amount of the polyfunctional acrylic monomer is 0.1 mol per mol of silyl acrylate compound 1 used.
1-9 is preferred. Examples of the polyfunctional acrylic monomer are shown below, but the present invention is not limited thereto.

[0033]

[Outside 11]

[0034]

[Outside 12]

[0035]

[Outside 13]

[0036]

[Outside 14]

[0037]

[Outside 15]

[0038]

[Outside 16]

[0039]

[Outside 17]

The volume resistance of the protective layer is 10 ¹⁰ to 10 ¹⁵ Ω / c.
m is preferred. The protective layer may contain conductive particles in order to adjust the resistance value of the protective layer. Although the content of the conductive particles cannot be unconditionally determined, it is preferably from 10% by weight to 70% by weight based on the protective layer in order to achieve the above volume resistance.

Examples of the conductive particles include zinc oxide, titanium oxide, tin oxide, antimony oxide, bismuth oxide,
Ultrafine metal oxide particles such as tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide can be used. One or a mixture of two or more of these metal oxides is used. The average particle size of the conductive particles is 0.
It is 3 μm or less, preferably 0.1 μm or less. The smaller the particle size of the conductive particles is, the better.
m or more.

In the present invention, various kinds of coupling agents and antioxidants may be added to the protective layer in order to further improve the dispersibility, adhesiveness, environmental resistance and the like.

The thickness of the protective layer in the present invention is 0.1 to 1
It is preferably 0 μm, and particularly preferably 0.5 to 7 μm.

The photosensitive layer may be a single layer, but is preferably formed by laminating a charge generation layer and a charge transport layer sequentially from the support side. This is because it is effective for improving high sensitivity and memory characteristics such as photo memory. Further, the charge transport layer and the charge generation layer may be sequentially laminated from the support side.

The charge generation layer is formed by applying and drying a dispersion of a charge generation material dispersed in a binder resin. The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

As the charge generating material, for example, azo pigments,
Examples include quinone pigments such as pyrenequinone and anthantrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, azurenium salt pigments, and phthalocyanine pigments such as copper phthalocyanine and titanyl phthalocyanine. Examples of the binder resin for the charge generation layer include polyvinyl butyral, polystyrene, polyvinyl acetate, acrylic resin, cellulose acetate, ethyl cellulose, and the like.

The content of the charge generation material is preferably from 20 to 80% by weight, more preferably from 30 to 70% by weight, based on the charge generation layer.

The charge transport layer is formed by applying and drying a dispersion of a charge transport material dispersed in a binder resin. The thickness of the charge transport layer is preferably from 5 to 40 μm, particularly preferably from 5 to 30 μm.

Examples of the charge transport material include polycyclic aromatic compounds having a structure such as biphenylene, anthracene, or phenanthrene in the main chain or side chain; nitrogen-containing ring compounds such as indole, carbazole, oxadiazole, and pyrazoline; and hydrazone compounds. , Styryl compounds and triarylamine compounds. Examples of the binder resin for the charge transport layer include polyester, polycarbonate, polystyrene, and polymethacrylate.
The content of the charge transport material is 20 to 8 with respect to the charge transport layer.
0% by weight, more preferably 30 to 70% by weight.

The charge transport layer has the following general formula (2)
Can be formed using a coating solution in which the polysilane is dissolved in a solvent such as dichloromethane or chloroform.

[0051]

[Outside 18] In the above formula (2), R ⁸ , T ⁹ and R ¹⁰ represent an alkyl group which may have a substituent or an aryl group which may have a substituent, and X may have a substituent. Good alkyl group,
It represents an alkoxy group which may have a substituent, an aryl group which may have a substituent or a halogen atom, and r, s and t are 0 or more, and are integers satisfying r + s + t> 10.

The alkyl group of R ⁸ , R ⁹ , R ¹⁰ and X is preferably, for example, methyl, ethyl and propyl, and the aryl group is preferably phenyl and naphthyl. As the alkoxy group for X, methoxy, ethoxy and propoxy are preferred. As the halogen atom for X, fluorine, chlorine and bromine are preferable. As the substituent which R ⁸ -R ¹⁰ and X may have, an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy, ethoxy and propoxy, and a halogen atom such as fluorine, chlorine and bromine are preferable.

Specific examples of the polysilane represented by the general formula (2) are shown below, but are not limited thereto.

[0054]

[Outside 19]

Polysilane has high mobility and is effective for memory characteristics such as ordinary photo memories. Further, since the protective layer of the present invention has a high density of the acrylic portion, when the charge transport layer is a combination of an ordinary charge transport material and a binder resin, the protective layer is expected to be slightly insufficiently cured. Polysilane is effective for the colloidal silica-based protective layer of the present invention which has no migration of low molecular components that cause insufficient curing, and particularly has a high surface acrylic density. The polysilane of the general formula (2) can be produced by the Wurtz method.

When the photosensitive layer is a single layer, the photosensitive layer is made of TiOP
It can be formed by mixing c or a bisazo pigment, a charge transport material, and a binder resin with a solvent, and applying and drying the mixture by a usual coating method. When the photosensitive layer is a single layer, the thickness of the photosensitive layer is 5 to 40 μm, and more preferably 10 to 30 μm.
m is preferred.

The support may be any as long as it has electrical conductivity, for example, aluminum,
A metal or alloy such as copper, chromium, nickel, zinc, stainless steel or the like formed into a drum or sheet, a metal foil such as aluminum or copper laminated on a plastic film, a plastic film made of aluminum, indium oxide, tin oxide, etc. And a metal, plastic film, paper, etc. provided with a conductive layer by applying a conductive substance alone or together with a binder resin.

Examples of the shape of the conductive support include a drum shape and a belt shape, and it is preferable that the shape is any shape most suitable for the applied electrophotographic apparatus.

An undercoat layer may be provided between the support and the photosensitive layer. The undercoat layer functions as a barrier layer or an adhesive layer for controlling charge injection at the interface with the photosensitive layer. The undercoat layer is mainly made of a binder resin, but may contain a metal or an alloy, or an oxide, a salt, a surfactant, or the like thereof. As the binder resin forming the undercoat layer, for example, polyester, polyurethane, polyacrylate, polyethylene,
Examples thereof include polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, polyamideimide, polysulfone, polyallyl ether, polyacetal, and butyral resin. The thickness of the undercoat layer is 0.05 to
7 μm is preferred, and particularly preferably 0.1 to 2 μm.

Each of the above layers can be formed by vapor deposition or coating. In particular, a coating method is preferable because films having various compositions can be formed in a wide range from a thin film to a thick film. Examples of the coating method include a dip coating method, a spray coating method, a beam coating method, a bar coating method, a blade coating method, and a roller coating method.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
RT printer, LED printer, LCD printer,
It can be widely used in electrophotographic applications such as facsimile and laser plate making.

The electrophotographic photosensitive member of the present invention is produced, for example, as follows.

A solution obtained by dissolving the material of the undercoat layer in a solvent is applied on an aluminum cylinder to form an undercoat layer, and then a charge generation layer and a charge transport layer are formed.

Next, a mixture of silyl acrylate, colloidal silica, and butanol is heated and cooled to condense. Further, a multi-valued acrylic monomer and conductive particles are mixed to prepare a coating liquid for a protective layer. Apply on layer. Finally, the protective layer is cured by, for example, irradiating with a high-pressure mercury lamp to prepare the electrophotographic photosensitive member of the present invention.

Next, an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention will be described.

In FIG. 1, reference numeral 1 denotes a drum type photosensitive member of the present invention, which is driven to rotate at a predetermined peripheral speed in a direction indicated by an arrow around a shaft 1a. The photoreceptor 1 receives a uniform charge of a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process,
Next, the exposure unit 3 receives light image exposure L (slit exposure or laser beam scanning exposure) by an image exposure unit (not shown). 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 a developing unit 4, and the developed toner image is transferred by a corona transfer unit 5 between a photosensitive unit 1 and a transfer unit 5 from a paper feeding unit (not shown). The recording material 9 is sequentially transferred onto the surface of the recording material 9 fed in synchronization. The recording material 9 to which the image has been transferred is separated from the surface of the photoreceptor, and
And the image is fixed and printed out of the machine as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by the removal of the untransferred toner by the cleaning unit 6, subjected to the charge removal treatment by the pre-exposure unit 7, and used repeatedly for image formation.

In the apparatus shown in FIG. 2, at least the photosensitive member 1, the charging means 2 and the developing means 4 are housed in a container 20 to form a process cartridge, and this process cartridge is attached and detached using the guide means 12 such as a rail of the present invention. It is freely configured. The cleaning means 6 may or may not be disposed in the container 20.

As shown in FIGS. 3 and 4, a direct charging member 10 is used as charging means, and the photosensitive member 1 is charged by bringing the direct charging member 10 to which a voltage is applied into contact with the photosensitive member 1. Is also good. (This charging method is hereinafter referred to as direct charging). 3 and 4, the toner image on the photoconductor 1 is also directly transferred to the recording material 9 by the charging member 23. That is, the direct charging member 23 to which the voltage is applied is
To transfer the toner image on the photoconductor 1 to the recording material 9.

Further, in the apparatus shown in FIG. 4, at least the photosensitive member 1 and the direct charging member 10 are housed in the first container 21 to form a first process cartridge, and at least the developing means 4
Are contained in a second container 22 to form a second process cartridge, and the first process cartridge and the second process cartridge are configured to be detachable. The cleaning means 6 may or may not be disposed in the container 21.

In the case where the electrophotographic apparatus is used as a copier or a printer, the light image exposure L uses reflected light or transmitted light from a document, or reads a document and converts it into a signal. This is performed by performing scanning, driving a light emitting diode array, driving a liquid crystal shutter array, or the like.

[0071]

The present invention will be described below with reference to examples. “Parts” shown below means parts by weight.

Example 1 On an aluminum cylinder (φ30 mm × 260 mm), 10 parts of an alcohol-soluble copolymerized nylon resin (weight average molecular weight: 28000) and 30 parts of methoxymethylated 6 nylon resin (weight average molecular weight: 30,000) were mixed with 260 parts of methanol. A solution prepared by dissolving in a mixed solvent of 40 parts of butanol was dip-coated and dried at 90 ° C. for 10 minutes.
An undercoat layer of μm was formed.

Next, 4 parts of a disazo pigment represented by the following structural formula,

[0074]

[Outside 20] After 2 parts of butyral resin (butyral conversion ratio: 65 mol%, weight average molecular weight: 24,000) and 100 parts of cyclohexanone were dispersed in a sand mill for 30 hours, 100 parts of tetrahydrofuran was added to prepare a coating liquid for a charge generation layer.
This coating solution was applied onto the undercoat layer by dip coating.
After drying for 0 minutes, a charge generation layer having a thickness of 0.3 μm was formed.

Next, 10 parts of a styryl compound represented by the following structural formula

[0076]

[Outside 21] And polycarbonate (weight average molecular weight 40,000) 1
It was dissolved in a mixed solvent of 0 parts of dichloromethane (20 parts) and chlorobenzene (60 parts) to prepare a charge transport layer coating solution.
This coating solution was dip-coated on the charge generation layer,
For 60 minutes to form a charge transport layer having a thickness of 20 μm.

Next, a coating solution for the protective layer was prepared by the following procedure. 10 parts of the exemplified compound 1 of silyl acrylate, colloidal silica (trade name: Nalcoag 1034A, Na
A mixture of 100 parts (manufactured by Ico Company) and 300 parts of t-butanol was heated to reflux for 5 minutes. After cooling, 1,4-butanediol diacrylate and the following P
O-modified trimethylolpropane triacrylate 1:
25 parts of one mixed solution were added.

[0078]

[Outside 22]

Next, the solvent was distilled off under reduced pressure to obtain a transparent solution. Next, the obtained mixture 100
2 parts of 2,2-diethoxyacetophenone and 50 parts of antimony-containing tin oxide fine particles having an average particle size of 0.02 μm (antimony content: 10 wt%) were mixed with each part to prepare a coating solution for a protective layer. . This coating solution is spray-coated on the charge transport layer, dried, and then 80 mW with a high-pressure mercury lamp.
UV irradiation at a light intensity of 3 μm / cm ² for 3 seconds.
m of the protective layer was formed to prepare an electrophotographic photosensitive member.

The prepared electrophotographic photosensitive member was transferred to a copying machine (NP-
3825, Canon), 23 ° C, 50% humidity
Dark portion potential V _D under normal temperature and normal humidity, sensitivity was measured Ideruta ₅₀₀ and the residual potential Vr. Table 1 shows the results. NP-3825
Was modified to measure the electrophotographic properties of the photoreceptor. Dark potential V _D indicates that charging ability as the absolute value is larger good sensitivity Ideruta ₅₀₀ is -200V from -700V
The amount of light required for attenuation was shown.

The images were visually evaluated under low temperature and low humidity of 10 ° C. and 15% under normal temperature and normal humidity, and under high temperature and high humidity of 35 ° C. and 85%. The results are shown in Table 2. Further, using another electrophotographic photoreceptor similarly prepared at room temperature and normal humidity for 1
100,000 sheets were passed, and the fluctuation amounts ΔV _D and ΔV _L of the dark portion potential and the bright portion potential at the initial stage and after 100,000 were measured. The results are shown in Tables 1 and 2. Note that the variation ΔV _L has an initial value of −2.
It was measured as 00V.

As shown in Tables 1 and 2 below, a stable image free of unevenness and black spots was obtained. Furthermore, the amount of potential fluctuation after durability was small, and a stable image could be maintained even after 100,000 repetitions of image formation.

Further, the photo memory and the transfer memory of the electrophotographic photosensitive member of this example were measured at normal temperature and normal humidity.

The measurement of the photo memory was performed as follows.

A part of the electrophotographic photosensitive member is covered with a light shielding member,
A white fluorescent lamp was applied under normal temperature and normal humidity for 15 minutes. Illuminance is 20
00 looks. Thereafter, the electrophotographic photosensitive member was left standing for 10 minutes, and the voltage was measured between the portion irradiated with the fluorescent lamp and the portion not irradiated. The photo memory was obtained by subtracting the voltage of the non-irradiated part from the voltage of the irradiated part.

The transfer memory was measured as follows.

Primary charging voltage Vd1 when transfer current is OFF
And the primary charging voltage Vd2 when the transfer current was ON, and the difference between Vd1 and Vd2 was used as the transfer memory. Table 1 shows the measurement results.

Examples 2 to 5 Except that the exemplified compounds 3, 5, 10 and 23 were used as the silyl acrylate used for preparing the coating solution for the protective layer,
In the same manner as in Example 1, the electrophotographic photosensitive members of Examples 2, 3, 4, and 5 were prepared and evaluated. The results are shown in Tables 1 and 2.

Comparative Example 1 An electrophotographic photosensitive member of Comparative Example 1 was prepared and evaluated in the same manner as in Example 1 except that the protective layer was not used. The results are shown in Tables 1 and 2. As a result, although the electrophotographic characteristics at the initial stage were good, the charging performance was reduced when the device was durable, and black spots were generated from about 50,000 sheets, so that a good image could not be obtained.

Comparative Example 2 Comparative Example 2 was repeated in the same manner as in Example 1 except that the protective layer was formed using the coating liquid for protective layer prepared in the following procedure in place of the protective layer in Example 1. Create an electrophotographic photoreceptor,
An evaluation was performed. The results are shown in Tables 1 and 2. As a result, image deletion occurred under high temperature and high humidity. Moreover, large variations in the light portion potential V _L even in endurance test, fogging occurs.

10 parts of an acrylic monomer having the following structural formula

[0092]

[Outside 23] And 100 parts of colloidal silica (described above), 2 parts of 2,2-diethoxyacetophenone, 100 parts of antimony-containing tin oxide fine particles as in Example 1, and 300 parts of t-butanol.
The parts were mixed and dispersed by a sand mill for 48 hours to prepare a protective layer coating liquid. Using this coating solution, a protective layer having a thickness of 3 μm was formed in the same manner as in Example 1.

[0093]

[Table 1]

[0094]

[Table 2]

Example 6 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% of antimony oxide (35% by weight of coating, average particle size of primary particles 0.3 μm), phenol resin 25 parts, methyl cellosolve 20 parts, methanol 2
0 parts and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, weight average molecular weight 300
0) 0.002 parts were dispersed for 2 hours in a sand mill using φ1 mm glass beads to prepare a conductive layer paint,
Dip-coated on an aluminum cylinder (φ30mm × 260mm), dried at 140 ° C for 30 minutes,
Then, a subbing layer was formed on the conductive layer in the same manner as in Example 1.

Next, 4 parts of a disazo pigment represented by the following structural formula,

[0097]

[Outside 24] 2 parts of polyvinyl benzal (benzalization ratio 80%, weight average molecular weight 12000) and 30 parts of cyclohexanone were mixed in a sand mill using glass beads having a diameter of 1 mm.
After dispersing for 5 hours, 60 parts of methyl ethyl ketone was added to prepare a charge generating layer coating liquid. This coating solution was applied onto the undercoat layer by dip coating and dried at 80 ° C. for 10 minutes to form a 0.3 μm-thick charge generating layer.

Next, a charge transport layer was formed on the charge generation layer in the same manner as in Example 1.

Next, a protective layer was formed in the same manner as in Example 1 except that the film thickness was changed to 5 μm on the charge transport layer, and an electrophotographic photosensitive member was prepared.

The produced electrophotographic photosensitive member was attached to a laser beam printer (Laser Shot 4plus, Hewlett-Packard), and evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4. Laser shot 4 pl
The us was modified to measure the electrophotographic characteristics of the photoreceptor.

As shown in Tables 3 and 4 below, a stable image free of image deletion and unevenness was obtained even under high temperature and high humidity. In addition, the amount of potential fluctuation after durability was small, and the potential stability was excellent.

Examples 7 to 10 As the silyl acrylate used for preparing the coating solution for the protective layer, Exemplified Compounds 4, 7, 11 and 22 were used.
In the same manner as in Example 6, the electrophotographic photosensitive members of Examples 7, 8, 9, and 10 were prepared and evaluated. The results are shown in Tables 3 and 4.

[0103]

[Table 3]

[0104]

[Table 4]

Example 11 An undercoat layer was formed on an aluminum cylinder (φ30 mm × 260 mm) in the same manner as in Example 1. Then, the coating liquid for a charge transport layer used in Example 1 was coated with the above-described coating liquid. The resultant was applied on the layer and dried to form a charge transport layer having a thickness of 18 μm.

Next, the coating solution for the charge generation layer used in Example 1 was applied on the charge transport layer and dried to a film thickness of 0.4 μm.
m of the charge generation layer was formed.

Next, a protective layer having a thickness of 3 μm was formed in the same manner as in Example 1 to prepare an electrophotographic photosensitive member. Copy the created electrophotographic photoreceptor to a copying machine (NP-3825, Canon)
And evaluated in the same manner as in Example 1.

Tables 5 and 6 show the results. In this example, the NP-3825 was modified so that it could be positively charged. In measuring ΔV _L , the initial value is 200
It was measured as V.

As a result, a stable image free from unevenness and black spots was obtained. Furthermore, the amount of potential fluctuation after durability was small, and a stable image could be maintained even after 100,000 repetitions of image formation.

Example 12 An electrophotographic photoreceptor was prepared in the same manner as in Example 11 except that Compound Example 6 was used as the silyl acrylate compound used for preparing the coating solution for the protective layer. evaluated. The results are shown in Tables 5 and 6.

Example 13 Compound Example 16 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, and zinc oxide having an average particle diameter of 0.1 μm was used as conductive particles.
An electrophotographic photosensitive member was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 11. The results are shown in Tables 5 and 6.

Example 14 Compound Example 17 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, and titanium oxide having an average particle diameter of 0.1 μm was used as conductive particles. Example 11 to prepare an electrophotographic photosensitive member
Was evaluated in the same way as The results are shown in Tables 5 and 6.

Example 15 Compound Example 21 was used as a silyl acrylate compound used for preparation of a coating solution for a protective layer, and tin oxide having an average particle diameter of 0.2 μm was used as conductive particles.
An electrophotographic photosensitive member was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 11. The results are shown in Tables 5 and 6.

Comparative Example 3 Example 1 was repeated except that no protective layer was used.
An electrophotographic photoreceptor of Comparative Example 3 was prepared and evaluated in the same manner as in Example 1. The results are shown in Tables 5 and 6. As a result, although the electrophotographic characteristics at the initial stage were good, when the device was durable, the charge generating layer on the surface was shaved on 400 sheets, making it difficult to obtain a good image.

[0115]

[Table 5]

[0116]

[Table 6]

Example 16 In the same manner as in Example 1, an aluminum cylinder (φ3
(0 mm × 260 mm) to form an undercoat layer.

Next, the diffraction angle 2θ ± 0.2 ° in the X-ray diffraction spectrum of CuKa was 9.0. , 14.2 °, 2
Sand mill using 4 parts of oxytitanium phthalocyanine having strong peaks at 3.9 ° and 27.1 °, 2 parts of polyvinyl butyral (trade name: SREC BM2, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone using φ1 mm glass beads After dispersing for 4 hours using an apparatus, 100 parts of ethyl acetate was added to prepare a coating liquid for a charge generation layer.
This coating solution was dip-coated on the undercoat layer to give a film thickness of 0.3
A μm charge generation layer was formed.

Next, 10 parts of a polysilane having the following structural formula (viscosity average molecular weight: 13000)

[0120]

[Outside 25] Was dissolved in a mixed solvent of 30 parts of toluene and 30 parts of tetrahydrofuran, and a coating solution for a charge transport layer prepared was coated on the charge generation layer, dried at 120 ° C. for 60 minutes, and dried.
A 0 μm charge transport layer was formed.

Next, a coating solution for a protective layer was prepared in the same manner as in Example 1. This coating liquid is spray-coated on the charge transport layer, dried, and then 80 mW / cm ^{2 with} a high-pressure mercury lamp.
Irradiation with UV light for 30 seconds was performed to form a protective layer having a thickness of 3 μm, thereby producing an electrophotographic photosensitive member.

The produced electrophotographic photosensitive member was attached to a digital copying machine (GP-55, Canon) and evaluated in the same manner as in Example 1. The results are shown in Tables 7 and 8. GP-55 was modified to measure the electrophotographic properties of the photoreceptor.
In Table 7, the sensitivity Ideruta ₄₀₀ is indicated by the amount of light required to dampen the -100V from -500 V. As a result, as shown in Tables 7 and 8 below, a stable image without unevenness or black spots could be obtained. Furthermore, the amount of potential fluctuation after durability was small, and a stable image could be maintained even after 100,000 repetitions of image formation.

Examples 17 to 20 Except that the exemplified compounds 3, 5, 10 and 23 were used as the silyl acrylate used for preparing the coating solution for the protective layer,
In the same manner as in Example 16, the electrophotographic photoreceptors of Example 17, Example 18, Example 19, and Example 20 were prepared and evaluated. The results are shown in Tables 7 and 8.

Comparative Example 4 Example 1 was repeated except that no protective layer was used.
In the same manner as in Example 6, an electrophotographic photosensitive member of Comparative Example 4 was prepared and evaluated. The results are shown in Tables 7 and 8. As a result, the electrophotographic characteristics were good in the initial stage, but when the device was durable, the charging ability was lowered and a good image could not be obtained from about 2,000 sheets.

[0125]

[Table 7]

[0126]

[Table 8]

Example 21 A coating material for a conductive layer was prepared in the same manner as in Example 6, dip-coated on an aluminum cylinder (φ30 mm × 260 mm) and dried at 140 ° C. for 30 minutes to form a 20 μm conductive layer. Next, an undercoat layer was formed on the conductive layer in the same manner as in Example 16.

Next, a coating solution for the charge generation layer was prepared in the same manner as in Example 16, and was applied by dip coating on the undercoat layer.
A 3 μm charge generation layer was formed.

Then, 10 parts of a polysilane having the following structural formula (viscosity average molecular weight: 12500) was formed on the charge generation layer.

[0130]

[Outside 26] Is dissolved in a mixed solvent of 30 parts of toluene and 30 parts of tetrahydrofuran, and a coating solution for a charge transport layer prepared by coating is applied,
After drying at 120 ° C. for 60 minutes, a charge transport layer having a thickness of 12 μm was formed.

Next, a protective layer was formed in the same manner as in Example 16 except that the film thickness was changed to 5 μm on the charge transport layer, and an electrophotographic photosensitive member was prepared.

The prepared electrophotographic photoreceptor was mounted on a digital copying machine similar to that in Example 16, and the evaluation of electrophotographic characteristics, image evaluation, and durability were performed in the same manner as in Example 1 except for the above. The results are shown in Tables 9 and 10.

As a result, as shown in Tables 9 and 10 below, a stable image free of image deletion and unevenness was obtained even under high temperature and high humidity. In addition, the amount of potential fluctuation after durability was small, and the potential stability was excellent.

Example 22 Compound Example 4 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, tin-doped indium oxide having an average particle diameter of 0.1 μm was used as conductive particles, and the other examples were used. An electrophotographic photosensitive member was prepared in the same manner as in Example 21 and evaluated in the same manner as in Example 21. The results are shown in Tables 9 and 10.

Example 23 Compound Example 7 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, and tin oxide having an average particle diameter of 0.3 μm was used as conductive particles.
An electrophotographic photoreceptor was prepared in the same manner as described above, and evaluated in the same manner as in Example 21. The results are shown in Tables 9 and 10.

Example 24 Compound Example 11 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, and antimony oxide having an average particle diameter of 0.1 μm was used as conductive particles. Then, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 21. The results are shown in Tables 9 and 10.

Example 25 Compound Example 27 was used as a silyl acrylate compound used for preparing a coating solution for a protective layer, zirconium oxide having an average particle diameter of 0.2 μm was used as conductive particles, and the other conditions were the same as in Example 21. Then, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 21. The results are shown in Tables 9 and 10.

[0138]

[Table 9]

[0139]

[Table 10]

[0140]

The electrophotographic photosensitive member of the present invention has excellent durability without being affected by the environment. Further, the transfer memory and the photo memory are low, and there is no accumulation of the residual potential even when used repeatedly. Therefore, according to the present invention, a high-quality image can always be formed without being affected by environmental changes.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an electrophotographic apparatus according to the present invention.

FIG. 2 is a diagram illustrating another example of the electrophotographic apparatus of the present invention.

FIG. 3 is a diagram showing another example of the electrophotographic apparatus of the present invention.

FIG. 4 is a diagram showing another example of the electrophotographic apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Charging means 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 10 Direct charging member

Continued on the front page (72) Inventor Hidetoshi Hirano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Akira Yoshida 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-6-11878 (JP, A) JP-A-4-273252 (JP, A) JP-A-61-72257 (JP, A) JP-A-4-163462 (JP, A) JP-A-4-226469 (JP, A) JP-A-6-3921 (JP, A) JP-A-8-95280 (JP, A) JP-A-2-151870 (JP, A) (58) Int.Cl. ⁷ , DB name) G03G 5/00 CA (STN)

Claims (13)

(57) [Claims] 1. An electrophotographic photosensitive member having at least a photosensitive layer and a protective layer on a support, wherein the protective layer is formed by curing a condensate of a silyl acrylate compound and colloidal silica. An electrophotographic photosensitive member characterized by the following. 2. The electrophotographic photoreceptor according to claim 1, wherein said silyl acrylate compound is represented by the following general formula (1). [Outside 1] In the above formula (1), R ¹ represents an alkyl group, R ² represents an alkyl group, an alkoxy group or an aryl group, R ^3,
R ⁴ , R ⁵ and R ^{6 each} represent a hydrogen atom, an alkyl group, an alkoxy group or an aryl group, R ⁷ represents an alkylene group, m represents an integer of 0 to 2, and n represents an integer of 1 to 3 , P and q each represent an integer of 0 or more. However, 0 <m +
n ≦ 3. 3. The electrophotographic photoreceptor according to claim 1, wherein a polyfunctional alkyl monomer is added to the condensate and cured. 4. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains conductive particles. 5. The electrophotographic photoreceptor according to claim 4, wherein said conductive particles are metal oxides. 6. An electrophotographic photoreceptor having at least a charge generation layer, a charge transport layer and a protective layer on a support,
The charge transport layer contains polysilane, the protective layer,
An electrophotographic photoreceptor formed by curing a condensate of a silyl acrylate compound and colloidal silica. 7. The electrophotographic photoreceptor according to claim 6, wherein the silyl acrylate compound is represented by the following general formula (1), and the polysilane is represented by the following general formula (2). [Outside 2] In the above formula (1), R ¹ represents an alkyl group, R ² represents an alkyl group, an alkoxy group or an aryl group, R ^3,
R ⁴ , R ⁵ and R ^{6 each} represent a hydrogen atom, an alkyl group, an alkoxy group or an aryl group, R ⁷ represents an alkylene group, m represents an integer of 0 to 2, and n represents an integer of 1 to 3 , P and an integer of q or more. However, 0 <m + n ≦
3. [Outside 3] In the above formula (2), R ⁸ , R ⁹ and R ¹⁰ represent an alkyl group which may have a substituent or an aryl group which may have a substituent, and X may have a substituent. Good alkyl group,
Represents an alkoxy group which may have a substituent, an aryl group which may have a substituent or a halogen atom, and r and s
And t are 0 or more and are integers satisfying r + s + t> 10. 8. The electrophotographic photoreceptor according to claim 6, wherein a polyfunctional alkyl monomer is added to the condensate and cured. 9. The electrophotographic photosensitive member according to claim 6, wherein the protective layer contains conductive particles. 10. The electrophotographic photoconductor according to claim 9, wherein the conductive particles are metal oxides. 11. An electrophotographic photoreceptor according to claim 1, a charging means for charging said electrophotographic photoreceptor, and an image exposure to said charged electrophotographic photoreceptor to form an electrostatic latent image. An electrophotographic apparatus comprising: an image exposing means for forming; and a developing means for developing the electrophotographic photoreceptor on which an electrostatic latent image is formed with toner. 12. A process cartridge comprising: the electrophotographic photosensitive member according to claim 1; and a charging member for charging the electrophotographic photosensitive member. 13. The process cartridge according to claim 12, further comprising developing means for developing an electrostatic latent image formed on said electrophotographic photosensitive member.