JP3039893B2 - Electrophotographic photosensitive member, electrophotographic apparatus having the same, and facsimile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member having an improved photosensitive layer, and more preferably to an organic electrophotographic photosensitive member having a photosensitive layer having a laminated structure of a charge generating layer and an improved charge transport layer. It relates to a photoconductor.

[0002]

2. Description of the Related Art Heretofore, polyvinyl carbazole, anthracene, oxadiazole and the like have been known as organic photoconductive substances. In addition, as a method for effectively increasing the sensitivity of these organic photoconductive materials, a charge generation layer that generates charge carriers by exposure and a charge transport layer that has the ability to transport the generated charge carriers are laminated. A structure has been proposed.

A copolymer having the structural units represented by the general formulas [1] and [2], and the structural unit represented by the formula [2] is 0.1% to the total weight of the copolymer. ~ 50
An electrophotographic photoreceptor containing a copolymer by weight has excellent initial lubricity and can maintain the lubricity permanently. Furthermore, since it has excellent wear resistance, it has excellent mechanical properties and durability. Further, it has high sensitivity, low residual potential, and excellent electrophotographic characteristics.

[0004]

However, by being subjected to a repetitive process including corona charging, exposure, development, transfer and cleaning, the surface of the photoreceptor is exposed to an oxidizing atmosphere such as ozone generated during corona charging. Due to exposure, it has the disadvantage of causing surface and interior degradation. Deterioration of the photoreceptor surface and the inside thereof causes deterioration of electrical characteristics, that is, lowering of sensitivity, lowering of potential, and increasing of residual potential, thereby causing reduction in image density of a copy and generation of fog afterimage.

Namely, the present inventors as a result of various investigations, in addition to NO _x of ozone generated as a cause of potential change of the conventional photosensitive member from the primary corona charger or a transfer corona charger of the electrophotographic process sensitive I found that it had a great effect on my body. In addition, it has been observed that NO _x penetrates not only from the surface of the photoreceptor but also from the inside of the photoreceptor layer to the vicinity of the support. They also found that they caused adsorption and decomposition reactions, causing potential fluctuations and sensitivity degradation.

In the present invention, the structural units represented by the general formulas [1] and [2] are the copolymers, and the structural unit represented by the formula [2] is based on the total weight of the copolymer. 0.1 ~
An electrophotographic photosensitive member containing a copolymer of 50% by weight, while maintaining their excellent properties, and are intended to be conferring resistance to NO _x, are considerably resistant NO _x resistance by arrangement of the present invention It was found to improve.

Accordingly, an object of the present invention is to provide a copolymer having the structural units represented by the general formulas [1] and [2], and wherein the structural unit represented by the formula [2] is An electrophotograph having excellent durability against surface deterioration due to an oxidizing atmosphere without impairing good properties, obtained by incorporating a copolymer that is 0.1 to 50% by weight based on the total weight. It is to provide a photoreceptor.

[0008]

That is, the present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following general formula [1]:

[0009]

Embedded image (Wherein A is a linear, branched or cyclic alkylidene group having 1 to 10 carbon atoms, an aryl-substituted alkylidene group, an arylenedialkylidene group, -O-, -S-, -CO
—, —SO— and —SO ₂ —, and R ₁ to R ₄
Represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group having 1 to 4 carbon atoms), and the following general formula [2]

[0010]

Embedded image (Wherein, R ₅ is an alkylene group or alkylidene group having 2 to 6 carbon atoms, R ₆ and R ₇ are alkyl groups having 1 to 3 carbon atoms,
A phenyl group or a substituted phenyl group, and n represents an integer of 1 to 200).
And the structural unit represented by the general formula [2] contains a copolymer in an amount of 0.1 to 50% by weight based on the total weight of the copolymer, and the photosensitive layer is an aromatic amine-based antioxidant. An electrophotographic photoreceptor characterized by containing:

In the case of a function-separated type photosensitive layer, the charge transport layer is
It is preferable to form the solution by applying a solution in which a charge transport material, an antioxidant, and a binder are dissolved in an appropriate solvent, and drying the solution. The binder used here has the following general formula [3] in which the structure of the above copolymer is summarized by one formula.

[0012]

Embedded image [3] (wherein, R _{1 to} R ₇ , A and n are as described above,
X and Y are weight% occupied by the respective structural units represented by the formulas [1] and [2], and Y represents a real number of 0.1 to 50).

As the antioxidant, an aromatic amine antioxidant is used.

[0014] In addition to the above copolymer, other binders can be appropriately mixed as the binder.

Examples of the binder that can be mixed include polyethylene, polypropylene, acrylic resin, vinyl chloride resin, vinyl acetate resin, polystyrene, phenol resin, epoxy resin, polyester resin, alkyd resin,
Examples thereof include polycarbonate, polymethyl methacrylate, vinylidene chloride, polyurethane, and copolymer resins containing two or more repeating units of these resins, and particularly preferred are polyester resins and polycarbonate resins.

The structure represented by the general formula [1] contained in the copolymer used in the present invention is introduced to give the copolymer an appropriate mechanical strength. Specific examples of the compound to be provided include the following.

[0017]

Embedded image

[0018]

Embedded image

[0019]

Embedded image

[0020]

Embedded image Among the above compounds, particularly exemplified compound No. 3,8,1
6, 19 and 21 are preferred.

The structural unit represented by the structural formula [2] is introduced into the copolymer simultaneously with the structural unit [1] for the purpose of improving the lubricity of the copolymer. Specific examples of the compound giving [2] include the following.

[0022]

Embedded image Examples of the charge transport material used in the present invention include pyrene, N-ethylcarbazole, N-isopropylcarbazole,
-Methyl-N-phenylhydrazino-3-methylidene-
9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N
-Diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3
-Methylidene-10-ethylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α
-Naphthyl-N-phenylhydrazone, p-pyrrolinodibenzaldehyde N, N-diphenylhydrazone, 1,
3,3-trimethylindolenine-ω-aldehyde-
Hydrazones such as N, N-diphenylhydrazone, p-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole; 1-
Phenyl-3- (p-diethylaminostyryl) -5
(P-diethylaminophenyl) pyrazolin, 1- [quinolyl (2)]-3- (p-diethylaminostyryl)
-5- (p-diethylaminophenyl) pyrazoline, 1
-[Pyridyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazolin, 1- [6-methoxy-pyridyl (2)]-3- (p
-Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazolin, 1- [pyridyl (3)]-3
-(P-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazolin, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -5-
(P-diethylaminophenyl) pyrazolin, 1- [pyridyl (2)]-3- (p-diethylaminostyryl)
-4-methyl-5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-methyl-p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1-phenyl -3- (p
-Diethylaminostyryl) -4-methyl-5- (p-
Diethylaminophenyl) pyrazoline, 1-phenyl-
3- (α-benzyl-p-diethylaminostyryl)-
Pyrazolines such as 5- (p-diethylaminophenyl) pyrazolin and spiropyrazolin, 2- (p-diethylaminostyryl) -6-diethylaminobenzoxazole, 2- (p-diethylaminophenyl) -4- (p-
Oxazole-based compounds such as dimethylaminophenyl) -5- (2-chlorophenyl) oxazole, 2- (p
Thiazole compounds such as -diethylaminostyryl) -6-diethylaminobenzothiazole, triarylmethane compounds such as bis (4-diethylamino-2-methylphenyl) phenylmethane, 1,1-bis (4-N,
N-diethylamino-2-methylphenyl) heptane,
And polyarylalkanes such as 1,1,2,2-tetrakis-4-N, N-dimethylamino-2-methylphenyl) ethane.

The mixing ratio of the binder and the charge transporting material is such that the charge transporting material is 10 parts by weight per 100 parts by weight of the binder.
It is preferable to set it to 500 weight. The thickness of this charge transport layer is 2 to 100 μm, preferably 5 to 30 μm.

The aromatic amine-based antioxidant used in the present invention includes, for example, those having the following structural formulas.

[0025]

Embedded image

[0026]

Embedded image The addition amount of these antioxidants varies depending on the kind of the compound generally used, but is 0.01 to 4% by weight, preferably 0.04 to 2% by weight based on the charge transporting material.

The above compounds may be used by mixing with each other at a preferable mixing ratio, or may be used by mixing with other antioxidants.

The solvent used for forming the charge generation layer of the present invention includes many useful organic solvents. Representative examples are aromatic hydrocarbons such as benzene, naphthalene, toluene, xylene, mesitylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenated aliphatics such as methylene chloride, chloroform and ethylene chloride. Examples thereof include cyclic or linear ethers such as hydrocarbons, tetrahydrofuran, and ethyl ether, and a mixed solvent thereof.

A typical structure of the electrophotographic photoreceptor of the present invention is one in which a charge generation layer and a charge transport layer are formed on a support. Examples of the support include metals such as aluminum, stainless steel, and copper; A cylindrical cylinder or film obtained by subjecting a plastic or the like to a conductive treatment or an undercoat treatment as necessary is used. The charge generation layer is made of selenium, selenium-telluride, amorphous silicon and zinc oxide,
Inorganic compounds such as cadmium sulfide, phthalocyanine, oxadiazole, bisbenzimidazole, organic pigments such as quinocyanine and bisazo pigments alone or in combination, formed by coating on a support by using a binder, or by vapor deposition or It can be formed by sputtering. The thickness of the charge generation layer is generally several μm
Hereinafter, it is preferably 0.1 to 1 μm.

FIG. 1 shows a schematic configuration example of a general transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum type photosensitive member of the present invention as an image bearing member, which is driven to rotate around an axis 1a in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then, in an exposure section 3, a light image exposure L (slit exposure / Laser beam scanning exposure). As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then developed with toner by developing means 4, and the developed toner image is transferred by a transfer means 5 between a photosensitive member 1 and a transfer means 5 from a paper feeding unit (not shown). The transfer material P is sequentially transferred onto the surface of the transfer material P which is synchronously taken out and fed.

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

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

As the uniform charging means 2 for the photosensitive member 1, a corona charging device is generally widely used. Transfer device 5
Also, corona transfer means are generally widely used. As an electrophotographic apparatus, a plurality of components such as the above-described photoreceptor, developing means, and cleaning means are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus body. May be. For example, photoconductor 1
The cleaning unit 6 and the cleaning unit 6 may be integrated into one device unit, and may be configured to be detachable using a guide unit such as a rail of the device body. At this time, the above-described device unit may be provided with a charging unit and / or a developing unit.

In the case where the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L is a signal reflected from or transmitted from a document or a signal read from the document, and scanning of a laser beam, an LED array , Or by driving a liquid crystal shutter array.

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

The controller 11 controls the image reading section 10 and the printer 19. The whole controller 11 is CP
It is controlled by U17. The read data from the image reading unit 10 is transmitted to the partner station through the transmission circuit 13. Data received from the partner station is sent to the printer 19 through the receiving circuit 12. The image memory 16 stores predetermined image data. The printer controller 18 controls a 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 and then decoded by the CPU 17 and sequentially stored in the image memory 16. Is stored. When the image information of at least one page is stored in the memory 16, the image of the page is recorded. The CPU 17 reads one page of image information from the memory 16 and sends the decoded one page of image information to the printer controller 18. Upon receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page.

The CPU 17 receives the next page during recording by the printer 19.

As described above, image reception and recording are performed.

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 laser plate making.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

(Example 1) Conductive titanium oxide powder 50 coated with tin oxide containing 10% antimony oxide
Parts, phenolic resin 25 parts, methyl cellosolve 20 parts,
5 parts of methanol and 0.002 parts of silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average molecular weight 3,000) were dispersed in a sand mill using φ1 mm glass beads for 2 hours to obtain a paint for a conductive layer. . The paint was applied on an aluminum sheet by a wire bar and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.

Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare a coating for an intermediate layer. This paint was applied on the conductive layer by a wire bar and dried at 100 ° C. for 20 minutes to form a 0.6 μm intermediate layer.

Next, the following structural formula

[0047]

Embedded image Was dispersed in a sand mill using φ1 mm glass beads for 12 hours, and then 60 parts of methyl ethyl ketone was dispersed in the mixture. In addition, a charge generation layer dispersion was obtained. This dispersion was applied on the above-mentioned intermediate layer with a wire bar and dried at 80 ° C. for 20 minutes to obtain a charge generation layer having a thickness of 0.2 μm.

Next, the structural formula

[0049]

Embedded image Was dissolved in a mixed solvent of 20 parts of dichloromethane and 40 parts of monochlorobenzene.

This solution was coated on the above-mentioned charge generation layer with a wire bar and dried at 120 ° C. for 60 minutes to form a film having a thickness of 23 μm.
m of the charge transport layer was formed.

Next, using this photoreceptor, an evaluation was made of the reduction in charging ability due to an oxidizing atmosphere.

As an evaluation method, the photoreceptor was allowed to stand in an oxidizing atmosphere of saturated nitric acid vapor at 25 ° C. for 60 minutes. Immediately after that, the charging ability was measured. did.

The results are shown in Table 1.

Example 2 A copolymer having the following composition:

[0055]

Embedded image A photoconductor was prepared and measured in exactly the same manner as in Example 1, except that the charge transport layer was formed using (viscosity average molecular weight 2.07 × 10 ⁴ ).

Table 1 shows the obtained results.

Example 3 A copolymer having the following composition:

[0058]

Embedded image A photoreceptor was prepared and measured exactly in the same manner as in Example 1, except that a charge transporting layer was formed using the photoreceptor.

Table 1 shows the obtained results.

Example 4 A copolymer having the following composition:

[0061]

Embedded image A photoreceptor was prepared and measured exactly in the same manner as in Example 1, except that a charge transporting layer was formed using the photoreceptor.

Table 1 shows the obtained results.

Example 5 A copolymer having the following composition:

[0064]

Embedded image A photoconductor was prepared and measured exactly in the same manner as in Example 1, except that the charge transport layer was formed using (viscosity average molecular weight 2.03 × 10 ⁴ ).

Table 1 shows the obtained results.

(Example 6) Charge generating agent having the following structure

[0067]

Embedded image A photoreceptor was prepared and measured in exactly the same manner as in Example 1 except that the charge transport layer was formed using

Table 1 shows the obtained results.

(Example 7) A copolymer having the following structural formula

[0070]

Embedded image A photoreceptor was prepared and measured in exactly the same manner as in Example 6, except that a charge transport layer was formed using the above-described material.

Table 1 shows the obtained results.

Example 8 A copolymer having the following composition:

[0073]

Embedded image A photoconductor was prepared and measured in exactly the same manner as in Example 7, except that the charge transport layer was formed using (viscosity average molecular weight 2.30 × 10 ⁴ ).

Table 1 shows the obtained results.

Example 9 A copolymer having the following composition:

[0076]

Embedded image A photoconductor was prepared and measured exactly in the same manner as in Example 1, except that the charge transport layer was formed using (viscosity average molecular weight 2.15 × 10 ⁴ ).

Table 1 shows the obtained results.

Example 10 A copolymer having the following composition:

[0079]

Embedded image A photoconductor was prepared and measured exactly in the same manner as in Example 1, except that the charge transport layer was formed using (viscosity average molecular weight 3.03 × 10 ⁴ ).

Table 1 shows the obtained results.

(Example 11) The following structural formula

[0082]

Embedded image A photoreceptor was prepared and evaluated in the same manner as in Example 1 using the above charge generation material.

Table 1 shows the obtained results.

(Example 12) The following structural formula

[0085]

Embedded image A photoreceptor was prepared and evaluated in the same manner as in Example 1 using the above charge generation material.

Table 1 shows the obtained results.

Comparative Example 1 A charge transport layer was formed using polycarbonate Z (viscosity average molecular weight 1.92 × 10 ⁴ ), and a photoconductor was prepared in the same manner as in Example 1 without using an antioxidant. Created and measured.

Table 1 shows the obtained results.

[0089]

[Table 1]

[0090]

According to the present invention, the photosensitive layer is a copolymer having the structural unit represented by the general formula [1] and the structural unit represented by the general formula [2], and the compound represented by the formula [2] Is 0.1% based on the total weight of the copolymer.
The electrophotographic photoreceptor has high lubricity and high abrasion resistance by containing a copolymer of about 50% by weight, and has excellent electrophotographic properties such as high sensitivity and low residual potential. Can have, and the photosensitive layer contains an aromatic amine-based antioxidant, without deteriorating the above excellent properties, deterioration of the surface due to an oxidizing atmosphere, in particular, mainly in electrophotographic methods it is effective in reducing the potential fluctuation for NO _x generated in the primary corona charger or a transfer corona charger. More specifically, it is possible to prevent the deterioration of the charging ability and the fluctuation of the sensitivity.

[Brief description of the 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 Photoconductor 2 Charging means 3 Exposure part 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidetoshi Hirano 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yoshiyuki Yoshihara 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Nobuyuki Hami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shinya Mayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Stocks In-company (56) References JP-A-5-72753 (JP, A) JP-A-2-240656 (JP, A) JP-A-4-163559 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G03G 5/05 101 G03G 5/05 104

Claims (3)

(57) [Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following general formula [1]: (Wherein A is a linear, branched or cyclic alkylidene group having 1 to 10 carbon atoms, an aryl-substituted alkylidene group, an arylenedialkylidene group, -O-, -S-, -CO
—, —SO— and —SO ₂ —, and R ₁ to R ₄
Represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group having 1 to 4 carbon atoms), and the following general formula [2]: (Wherein, R ₅ is an alkylene group or alkylidene group having 2 to 6 carbon atoms, R ₆ and R ₇ are alkyl groups having 1 to 3 carbon atoms,
A phenyl group or a substituted phenyl group, and n represents an integer of 1 to 200).
And the structural unit represented by the general formula [2] contains a copolymer in an amount of 0.1 to 50% by weight based on the total weight of the copolymer, and the photosensitive layer is an aromatic amine-based antioxidant. An electrophotographic photoreceptor comprising: 2. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 3. An electrophotographic photosensitive member according to claim 1, wherein
A facsimile having a receiving means for receiving image information from a remote terminal.