JP2012123379A - Electrophotographic photoreceptor, and electrophotographic cartridge and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor capable of suppressing line defects such as black stripes and white stripes in solid images such as pictures while excellently maintaining resistance to film thinning during the image formation, image density under a low temperature and low humidity environment, filming resistance, and cleaning property.SOLUTION: An outermost layer of an electrophotographic photoreceptor contains a resin having a polysiloxane structure in at least a part of a polymer terminal and a repeating structural unit, and free silicone content in the outermost surface layer is equal to or less than a specific amount.

Description

  The present invention relates to an electrophotographic photoreceptor excellent in cleaning properties, filming resistance, electrical characteristics, particularly suppression of line defects such as black streaks and white streaks in solid images such as photographs, and an electrophotographic cartridge using the same. It is about.

  In recent years, the use of image forming apparatuses such as electrophotographic copying machines has been expanded, and the market demand for image quality has been increasing. In office documents, in addition to the development of mapping technology and latent image formation technology for input, the types of character hieroglyphics are more abundant and finer at the time of output. Due to development, there is a demand for reproducibility of a latent image with extremely high image quality, which has few defects and unclearness in a printed image. In particular, durability against line defects is required for high density images such as photographs.

Conventionally, this type of defect has been dealt with by charging means (Japanese Patent No. 3814556, Japanese Patent Application Laid-Open No. 2003-316035, Japanese Patent No. 3302106, Japanese Patent Application Laid-Open No. 2001-117418). However, the charging means alone increases the load on the surface of the electrophotographic photosensitive member, and improvements from the electrophotographic photosensitive member have been demanded.
Since the electrophotographic photosensitive member is repeatedly used in an electrophotographic process, that is, a cycle of charging, exposure, development, transfer, cleaning, static elimination, and the like, it is deteriorated by various stresses during that time. Such deterioration includes, for example, strongly oxidative ozone and NOx generated from a corona charger that is normally used as a charger, which gives chemical damage to the photosensitive layer, or a carrier (current) generated by image exposure. Is chemically and electrically deteriorated due to the fact that the composition of the photosensitive layer decomposes due to flowing in the photosensitive layer, static elimination light, or external light. In addition, there are mechanical deteriorations such as abrasion of the photosensitive layer surface due to rubbing of a cleaning blade, a magnetic brush or the like, contact with a developer, paper, etc., scratches, and film peeling. In particular, the damage generated on the surface of the photosensitive layer is likely to appear on the copy image, and directly impairs the image quality, which is a major factor that limits the life of the photoreceptor. In other words, in order to develop a long-life photoreceptor, it is essential to increase the mechanical strength as well as the electrical and chemical durability.

On the other hand, with the trend toward higher image quality, higher resolution, and higher speed printing, there are increasing demands for improved toner transfer properties, prevention of filming, improvement of cleaning properties, and prevention of abnormal noise. These are problems that occur between the toner, the cleaning blade, the charging member, and the like that are in contact with the surface of the photoconductor. Improvement of the surface of the photoconductor is required to solve the problem.
In the case of a laminated type photoreceptor, it is the charge transfer layer that is subject to such load and surface property problems. The charge transfer layer is usually composed of a binder resin and a charge transfer material, and since the amount of the charge transfer material doped is considerably large, a sufficient mechanical strength has not been achieved.

  In addition, due to high-speed printing, a material compatible with a high-speed electrophotographic process is demanded. In this case, in addition to high sensitivity and long life, the photosensitive member must have good responsiveness because the time from exposure to development is shortened. It is known that the responsiveness of the photoreceptor is governed by the charge transfer layer, particularly the charge transfer substance, but also greatly changes depending on the binder resin.

In recent years, a photoreceptor having better surface slip has been desired as the image quality is improved. In order to improve the slipperiness of the surface, a polysiloxane block copolymer is used as a binder (Japanese Patent Laid-Open Nos. 61-132955, 2-2406655, and 3-185451). Polycarbonate is used (JP-A-7-261440), fluorine atom-containing polycarbonate is used (JP-A-5-306335, JP-A-6-32884, JP-A-6-282944), polyester carbonate and polysiloxane Have been proposed (Japanese Patent Laid-Open No. 8-234468), polysiloxane-terminated polyester (Japanese Patent Laid-Open No. 2002-128883), etc. Or wear resistance is impaired, or electrical characteristics are adversely affected. It contained the problem. Thus, a resin in which a polysiloxane structure is modified with a polyarylate resin (Japanese Patent Laid-Open No. 2010-126652) has been proposed, and it has been reported that the wear resistance and electrical characteristics have been improved.

Japanese Patent No. 3814556 JP 2003-316035 A Japanese Patent No. 3302106 JP 2001-117418 A Japanese Patent Application Laid-Open No. 61-132594 JP-A-2-240655 Japanese Patent Laid-Open No. 3-185451 JP 7-261440 A JP-A-5-306335 JP-A-6-32884 Japanese Patent Laid-Open No. 6-282094 JP-A-8-234468 JP 2002-128883 A JP 2010-126652 A

However, it has been found that in any case, there is a problem that a line defect such as a black stripe or a white stripe, particularly a white stripe defect occurs in the solid image.
Line defects such as black streaks and white streaks in solid images as described above were thought to be caused by uneven charging of the charging roller. However, even in the contact charging method in which uneven charging is unlikely to occur, white streak defects are present. It was found to occur. Therefore, as a result of intensive studies, the present applicant has found that when the free silicone, typically a silicone oil used as a leveling agent (roughening prevention agent), is contained in the outermost layer of the photoreceptor more than a certain amount. The present inventors have newly found that white streak defects are caused by scratches on the surface of the photoreceptor. However, if the free silicone content in the outermost layer of the photoconductor is too small, white streak defects are improved, but it is difficult to achieve compatibility with sufficiently suppressing (leveling) the surface of the photoconductor. Met.

  As a result of intensive studies in view of the above problems, the present applicant has found that the outermost layer of the photoreceptor contains a resin having a polysiloxane structure at least at the polymer terminal and at least a part of the repeating structural unit, and the free silicone in the outermost layer An electrophotographic photoreceptor having a specific content or less maintains black stripes in solid images such as photographs while maintaining good image density, filming resistance, and cleaning properties under low film thickness, low temperature, and low humidity environments. The present inventors have found that line defects such as white stripes can be suppressed.

That is, the gist of the present invention resides in the following [1] to [7].
(1) The outermost surface layer of the electrophotographic photosensitive member contains a polycarbonate resin or a polyester resin having a polysiloxane structure at least in a polymer terminal and a repeating structural unit, and the free silicone content in the outermost layer Is an electrophotographic photosensitive member, characterized in that it is 100 ppm or less.
(2) The electrophotographic photosensitive member according to (1), wherein the outermost layer of the photosensitive member contains a polyarylate resin having no polysiloxane structure.
(3) In the polycarbonate resin or polyester resin having the polysiloxane structure, the ratio of the polysiloxane structure in the polycarbonate resin or polyester resin is 2% by mass or more and 10% by mass or less (1) or (2) ).
(4) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the polyester resin having a polysiloxane structure has a repeating structure represented by the following general formula (11).

(In General Formula (11), R ^{1 to} R ⁸ are each independently a hydrogen atom, an alkyl group that may have a substituent having 1 to 20 carbon atoms, an alkoxyl group, or an optionally substituted aromatic group. X ¹ represents any one of a group, X ¹ represents a single bond, an alkylene group, —CR ⁹ R ¹⁰ —, an oxygen atom, or a sulfur atom, R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a carbon number of 1; ~ 20 alkyl groups,
Either an aromatic group which may have a substituent, or a group which forms a ring which may have a substituent when R ⁹ and R ¹⁰ are bonded to each other is shown. )
(5) The electrophotographic photosensitive member according to (4), wherein the general formula (11) is represented by the following general formula (12).

(In General Formula (12), R ^{1 to} R ⁸ are each independently a hydrogen atom, an alkyl group which may have a substituent having 1 to 20 carbon atoms, an alkoxyl group, or an optionally substituted aromatic group. Each of R ⁹ and R ¹⁰ independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,
Either an aromatic group which may have a substituent, or a group which forms a ring which may have a substituent when R ⁹ and R ¹⁰ are bonded to each other is shown. )
(6) The electrophotographic photosensitive member according to any one of (1) to (5), a charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image obtained by performing image exposure on the charged electrophotographic photosensitive member. An electrophotographic cartridge comprising: an image exposure unit for forming the electrostatic latent image; a developing unit for developing the electrostatic latent image with toner; and a transfer unit for transferring the toner to a transfer target.
(7) An electrostatic latent image is formed by exposing the electrophotographic photosensitive member according to any one of (1) to (5), charging means for charging the electrophotographic photosensitive member, and exposure to the charged electrophotographic photosensitive member. Exposure means for developing, developing means for developing the electrostatic latent image with toner, transfer means for transferring the toner to a transfer target, and fixing means for fixing the toner transferred to the transfer target. An image forming apparatus.

  According to the present invention, it is excellent in CL property, filming property, abrasion property, low density in low temperature and low humidity environment, and line defects such as white stripes in solid images such as photographs can be solved.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. It is an X-ray diffraction diagram showing a powder X-ray diffraction spectrum of oxytitanium phthalocyanine used in Examples and Comparative Examples of the present invention. It is an X-ray diffraction diagram showing a powder X-ray diffraction spectrum of oxytitanium phthalocyanine used in Examples and Comparative Examples of the present invention. It is an X-ray diffraction diagram showing a powder X-ray diffraction spectrum of oxytitanium phthalocyanine used in Examples and Comparative Examples of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention. it can.
The electrophotographic photosensitive member of the present invention has a free silicone content of 100 ppm or less in the outermost layer of the photosensitive member, and further contains a polycarbonate resin or a polyester resin having a polysiloxane structure at the polymer terminal in the outermost layer. .

<1. Free silicone>
[1-1. Free silicone structure]
The free silicone contained in the present invention is assumed to be a polysiloxane compound having both structural units represented by the following general formulas (1a) and (1b) in the molecule.

In the general formula (1a) and (1b), represents R ^A and R ^C are each independently may be substituted hydrocarbon group, R ^B has at least 3 carbon atoms, a substituent And R ^D represents a divalent hydrocarbon group having 1 to 3 carbon atoms, and R ^E represents a hydrocarbon group having 3 or more carbon atoms, which may have a substituent. To express. In the above formulas (1a) and (1b), a ₁ and a ₂ each independently represent an integer of ₁ to 500.

R ^A and R ^C each independently represents a hydrocarbon group which may have a substituent, and the hydrocarbon group is preferably an alkyl group, more preferably an alkyl group having 1 to 30 carbon atoms. When the number of carbons exceeds 30, the compatibility with the binder tends to decrease.
R ^B is at least 3 carbon atoms, represents a hydrocarbon group which may have a substituent, preferably an alkyl group having 5 to 30 carbon atoms as the hydrocarbon group, an alkyl group having 8 to 20 carbon atoms Further preferred. When the carbon number is larger than the above range, the compatibility with the binder tends to be reduced, and when it is smaller than the above range, the effect of reducing the friction of the outermost layer tends to be insufficient.

^RD represents a divalent hydrocarbon group having 1 to 3 carbon atoms, preferably a divalent alkylene group having 1 to 3 carbon atoms, and specifically includes a methylene group, an ethylene group, a propylene group, and propane. -1,3-diyl group. Of these, a methylene group and an ethylene group are more preferable.
R ^E represents a hydrocarbon group having 3 or more carbon atoms, which may have a substituent, and the hydrocarbon group is preferably an alkyl group having 3 to 8 carbon atoms. Alkyl groups having tertiary butyl units are preferred. Here, the isopropyl unit means that part or all of the alkyl group is an isopropyl [(CH ₃ ) ₂ CH] atomic group. Specifically, for example, an isopropyl group, an isobutyl group, a 3-methylbutyl group, a 3-methyl-2-butyl group, or the like corresponds to an alkyl group having 3 to 8 carbon atoms having an isopropyl unit.

Similarly, the tertiary butyl unit means that part or all of the alkyl group is a tertiary butyl [(CH ₃ ) ₃ C] atomic group. Specifically, for example, a tertiary butyl group, a dimethylpropyl group, a 3,3-dimethyl-2-butyl group and the like correspond to an alkyl group having 3 to 8 carbon atoms having a tertiary butyl unit. Among these, an isopropyl group, an isobutyl group, and a tertiary butyl group are particularly preferable.

Preferable substituents for the hydrocarbon groups represented by R ^A , R ^B , R ^C and R ^E include halogen atoms, alkoxy groups, alkylthio groups, mercapto groups, cyano groups and nitro groups. However, unsubstituted ones are preferred.
In particular, when R ^E has an isopropyl unit [(CH ₃ ) ₂ CH] or a tertiary butyl unit [(CH ₃ ) ₃ C], the affinity with the binder, particularly with the benzene ring in the binder resin molecule, In view of affinity, at least the isopropyl unit [(CH ₃ ) ₂
CH] or tertiary butyl unit [(CH ₃ ) ₃ C] is preferably unsubstituted.
Further, the sum of the carbon numbers of R ^B and R ^E is preferably 6 to 25, more preferably 8 to 20, and particularly preferably 10 to 18 in consideration of compatibility with the binder and a friction reducing effect.

  The polysiloxane compound contained in the present invention may contain a structural unit other than the structural units represented by the general formulas (1a) and (1b) (hereinafter referred to as other structural units). From the viewpoint of ensuring the ratio, the proportion of the structural unit represented by the general formula (1a) is preferably 1% by number or more, more preferably 3 to 90% by number, and particularly preferably 10 to 10% in all the structural units. 70% by number.

  Further, from the viewpoint of securing the affinity with the binder resin, the proportion of the structural unit represented by the general formula (1b) is preferably 1% by number or more, more preferably 3 to 90% by number in all the structural units. And particularly preferably 10 to 70% by number. The ratio (number ratio) of the structural unit (1a) to the structural unit (1b) is preferably 1: 9 to 9: 1, more preferably 1: 4 to 3: 2, and 1: 3 to 1. Is particularly preferred.

The ratio of the number of carbon atoms (N _C ) to the number of silicon atoms (N _Si ) in the polysiloxane compound (
(N _C / N _Si ) is preferably 4 to 20 and more preferably 6 to 15 as the whole polysiloxane compound. Further, the number of oxygen atoms (N _O) and silicon atoms (N _Si) ratio (N _O / N _Si) is preferably 1.1 to 2, more preferably is 1.2 to 1.8 . When the polysiloxane compound contained in the present invention contains other structural units, the other structural units are preferably dialkylsilyloxy structural units, and more preferably dimethylsilyloxy structural units.

The terminal of the polysiloxane compound is preferably a trialkylsilyl group, more preferably a trimethylsilyl group. The content of the polysiloxane compound is preferably 0.005 to 10% by weight, more preferably 0.01 to 1% in the total solid content of the outermost layer.
When the content is significantly larger than the above range, the required hardness as a layer is difficult to be secured, and when it is extremely small, the friction reducing effect tends to be insufficient. These polysiloxane compounds can be used in a dispersed state or in a compatible state in a binder resin, but it is preferable to use at least a part of them in a compatible state. A highly soluble binder resin is selected. The molecular weight of the polysiloxane compound is usually 100 to 70000, preferably 5000 to 30000, and more preferably 10,000 to 20000. When the molecular weight is significantly smaller than the above range, the effect as a leveling agent of the polysiloxane compound tends to be reduced, and when the molecular weight is significantly larger than the above range, the compatibility with the binder resin tends to be reduced. .

  Examples include a mixture of an alkyl-modified polysiloxane represented by the following structural formula (2a-1) and an alkoxy-modified polysiloxane represented by the following structural formula (2a-2) described in Japanese Patent No. 4198729, and JP-A-2002 A mixture of dimethylsiloxane and aliphatic saturated hydrocarbon (trade name Pro-sur manufactured by German Additives) described in 323785 and polydimethylsilicone oil represented by the following structural formula (2b) (manufactured by Shin-Etsu Silicone Co., Ltd.) , Trade name KF96).

In the above formulas (2a-1), (2a-2) and (2b), b _{1 to} b ₃ each independently represents an integer of ₁ to 500.
[1-2. Free silicone content]
In the present invention, the free silicone content in the outermost layer of the photoreceptor is usually 100 ppm or less, preferably 80 ppm or less, more preferably 50 ppm or less, and particularly preferably 0, from the viewpoint of suppressing white stripe defects. 0.0 ppm or less. The content of free silicone in the outermost surface layer of the photoreceptor is controlled by a technique such as adjusting the amount of free silicone charged at the time of creating the outermost layer forming coating solution.

Although it is not scientifically clear why the present invention has an effect on white streak defects, it is considered as follows. When the surface of the photosensitive layer where the scratch is generated is charged, free silicone is collected. Since it is difficult to develop where there is a large amount of free silicone, it is thought that white stripe line defects will occur. Therefore, if the silicone is chemically bonded to the resin, it does not move even when charged like free silicone, and it is assumed that white streak defects do not occur while maintaining slipperiness.

<2. Polycarbonate resin or polyester resin having a polysiloxane structure in at least a part of the polymer terminal and the repeating structure>
The outermost layer of the electrophotographic photosensitive member of the present invention contains a polycarbonate resin or a polyester resin having a polysiloxane structure at least at a part of the polymer terminal or the repeating structure.

[2-1. Polycarbonate resin and polyester resin having polysiloxane structure at least at part of polymer terminal]
(2-1-1. Bisphenol component and polymer terminal structure)
The polycarbonate resin and the polyester resin having a polysiloxane structure at the polymer terminal contained in the outermost layer of the electrophotographic photosensitive member of the present invention have a bisphenol component represented by the following general formula (1), and the polymer terminal. If it is a polycarbonate resin and polyester resin which have a structure represented by the following general formula (2) in at least one part of this, it will not specifically limit.

In general formula (1), R ^{1 to} R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a halogen, a halogenated alkyl group, an alkoxy group, or a nitro group. Or the aryl group which may have a substituent is represented.
X is

, R ^{9 to} R ¹⁵ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms that may have a substituent, or a substituent. An alkenyl group having 3 to 10 carbon atoms, a halogen, an alkoxyl group, or an aryl group having 6 to 20 carbon atoms which may have a substituent, and Z represents a carbon to be bonded to and 3 to 20 carbon atoms. A represents an integer of 0 or more and 4 or less, l represents an integer of 1 or more and 6 or less, and m represents an integer of 2 or more and 20 or less.
X is especially

Or

It is preferable that

It is more preferable that R ⁹ and R ¹⁰ are each independently an alkyl group having 2 or less carbon atoms, and it is particularly preferable that R ⁹ is a hydrogen atom and R ¹⁰ is a methyl group.

In general formula (2), W is a single bond, O, CO, COO, NH, NHCO, S, SO, SO.
₂ represents a divalent organic group containing at least one of aliphatic and aromatic, and R ^{16 to} R ¹⁸ are siloxane groups at least one of which is represented by the following general formula (3). The remainder represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a halogen, a halogenated alkyl group, an alkoxyl group, or an aryl group which may have a substituent.

In General Formula (3), R ^{19 to} R ²¹ represent an alkyl group or an aryl group, and n represents an integer of 1 to 500.
Although the polysiloxane structure which the polycarbonate resin and polyester resin used for this invention have in at least one part of a polymer terminal is shown below, arbitrary things can be used unless the effect of this invention is impaired remarkably.

(2-1-2. Dicarboxylic acid component of polyester resin)
The dicarboxylic acid component which is a dicarboxylic acid residue in the polyester resin contained in the present invention is represented by the following general formula (4).

In General Formula (4), Ar ¹ and Ar ² each independently represent an arylene group which may have a substituent, and X ² represents a single bond, an oxygen atom, a sulfur atom, or the following General Formula (5). Or a group represented by the following general formula (6), wherein k represents an integer of 0 or more.

R ²² and R ²³ in the general formula (5) each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ²² and R ²³ may be bonded to form a ring.

R ²⁴ in the general formula (6) is an alkylene group, an arylene group, or a group represented by the following general formula (7).

R ²⁵ and R ²⁶ in the general formula (7) each independently represent an alkylene group, and Ar ³ represents an arylene group.
Examples of the dicarboxylic acid residue contained in the general formula (4) include structures represented by the following general formulas [I] to [VI]. Here, k is an integer of 0 or more, but an integer of 0 to 5 is preferable from the viewpoint of electrical characteristics and scratch resistance, and more preferably 0 or 1.

From the viewpoint of film resistance, k is preferably 1 and X ² is an oxygen atom, the following general formula (8)
It is represented by

Ar ¹² and Ar ¹³ in the general formula (8) are as described above, and preferably a phenylene group having no substituent.
Specific examples of the preferred dicarboxylic acid residue represented by the general formula (8) include diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,3′-dicarboxylic acid residue, diphenyl ether-2,4 ′. -Dicarboxylic acid residue, diphenyl ether-3,3'-dicarboxylic acid residue, diphenyl ether-3,4'-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid residue and the like. Among these, considering the simplicity of production of the dicarboxylic acid component, diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid Residues are more preferred, and diphenyl ether-4,4′-dicarboxylic acid residues are particularly preferred.

Specific examples of the dicarboxylic acid residues other than those represented by the general formula (8) include phthalic acid residues, isophthalic acid residues, terephthalic acid residues, toluene-2,5-dicarboxylic acid residues, p Xylene-2,5-dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2 '-Dicarboxylic acid residue, biphenyl-4,4'-dicarboxylic acid residue can be mentioned, preferably phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-
Dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-dicarboxylic acid residue, biphenyl-4,4′-dicarboxylic acid residue, particularly preferably isophthalic acid residue These are terephthalic acid residues, and a plurality of these dicarboxylic acid residues can be used in combination.

  The polyester resin may be a resin containing another dicarboxylic acid component and enclosing the general formula (4) in a part of the structure. Specific examples of other dicarboxylic acid residues include adipic acid residues, suberic acid residues, sebacic acid residues, pyridine-2,3-dicarboxylic acid residues, pyridine-2,4-dicarboxylic acid residues, pyridine -2,5-dicarboxylic acid residue, pyridine-2,6-dicarboxylic acid residue, pyridine-3,4-dicarboxylic acid residue, pyridine-3,5-dicarboxylic acid residue, preferably, These are adipic acid residues and sebacic acid residues, and a plurality of these dicarboxylic acid residues can be used in combination.

  In addition, when it has the dicarboxylic acid residue represented by General formula (4) and the other dicarboxylic acid residue mentioned above, the dicarboxylic acid residue represented by General formula (4) is 70 as the number of repeating units. % Or more is preferable, 80% or more is more preferable, and 90% or more is particularly preferable. Most preferably, when having only the dicarboxylic acid residue represented by the general formula (4), that is, the dicarboxylic acid residue (4) represented by the general formula (4) is 100% as the number of repeating units. This is the case.

  Moreover, when it has the dicarboxylic acid residue represented by General formula (8) and the other dicarboxylic acid residue mentioned above, the dicarboxylic acid residue represented by General formula (8) is usually as the number of repeating units. From the viewpoint of film resistance, it is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. Most preferably, it has only the dicarboxylic acid residue represented by the general formula (8), that is, the dicarboxylic acid residue represented by the general formula (8) is 100% as the number of repeating units. is there.

[2-2. Polycarbonate resin or polyester resin having a polysiloxane structure in at least a part of the repeating structural unit]
(2-2-1. Bisphenol component having a polysiloxane structure)
The polycarbonate resin and polyester resin having a polysiloxane structure in the repeating structural unit of the diol component contained in the outermost layer of the electrophotographic photoreceptor of the present invention are represented by the following general formula (9) or the following general formula (10). The polycarbonate resin and polyester resin having a diol component are not particularly limited.

In general formula (9), R < ²⁷ > -R < ³⁰ > respectively independently represents the alkyl group which may have a substituent, the aryl group which may have a substituent, or the said General formula (3). , P and q each independently represents an integer of 0 to 500.

In the general formula (10), R ^{31 to} R ³⁷ each independently represents an alkyl group or an aryl group which may have a substituent, and R ^★ represents an alkyl group which may have a substituent, The aryl group which may have a substituent or the said General formula (2) is represented. f to j each independently represents an integer of 0 to 500.
In the present invention, the proportion (mol%) of the substance amount of the bisphenol component represented by the general formula (10) contained in one molecule of polycarbonate or polyester is not particularly limited as long as the effect of the present invention is not significantly affected. However, the upper limit is usually 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, particularly preferably 5 mol% or less, while the lower limit is usually 0.001 mol% or more. Yes, preferably 0.01 mol% or more, more preferably 0.05 mol% or more. Further, the ratio (wt%) of the weight of the bisphenol component represented by the general formula (10) contained in one molecule of polycarbonate or polyester is not particularly limited as long as it does not significantly affect the effect of the present invention. However, it is usually 30 wt% or less, preferably 20 wt% or less, more preferably 10 wt% or less, while the lower limit is usually 0.01 wt% or more, preferably 0.05 wt% or more. Yes, more preferably 0.1 wt%.

(2-2-2. Other components)
The other bisphenol component contained as a copolymer component separately from the bisphenol component (2-2-1.) Is a bisphenol represented by the general formula (1) described in (2-1-1.) Above. The components are preferably used as well.
Moreover, the polycarbonate resin or polyester resin which has a polysiloxane structure in the repeating structural unit contained in this invention may have a polysiloxane structure at the polymer terminal, and the structure is the above (2-1-1-. It is represented in the same manner as the general formula (2) described in 1.).

In addition, as the dicarboxylic acid component of the polyester resin having a polysiloxane structure in the repeating structural unit contained in the present invention, the dicarboxylic acid component described in (2-1-2.) Is preferably used.
Among the polycarbonate resins and polyester resins having a polysiloxane structure in at least a part of the polymer ends and repeating structures mentioned in [2-1] and [2-2] above, from the viewpoint of cleaning properties and filming resistance To those represented by the following general formula (11) are particularly preferred, and those represented by the following general formula (12) are most preferred.

In the above formula (11) and (12), X ¹ is the same as X described above ^{(2-1-1), R 1 R 1} ~R 10 is described above (2-1-1) is the same as that of the ~R ^10.
[2-3. Content of polycarbonate resin or polyester resin having polysiloxane structure at least in part of polymer terminal and repeating structure]
In the present invention, from the viewpoint of obtaining sufficient surface slipperiness of the surface of the photoreceptor, the content of the polycarbonate resin or polyester resin having a polysiloxane structure at the polymer terminal is based on 100 parts by mass of the binder resin contained in the photosensitive layer. The upper limit is usually 100 parts by mass or less, preferably 50 parts by mass or less, more preferably 25 parts or less, while the lower limit is usually 2 parts by mass or more, preferably 4 parts by mass or more. More preferably, it is 10 parts by mass or more. It depends on the content of polysiloxane contained in the polycarbonate resin or polyester resin having a polysiloxane structure at the polymer terminal shown below.

[2-4. Ratio of polysiloxane structure in polycarbonate resin or polyester resin having polysiloxane structure at least in part of polymer terminal and repeating structure]
The upper limit of the proportion of the polysiloxane structure contained in the polycarbonate resin or polyester resin having a polysiloxane structure at least in part of the polymer terminal and the repeating structure is usually 10% by mass or less, preferably 7% by mass. On the other hand, the lower limit is usually 2% by mass or more, preferably 4% by mass or more.

<3. Electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention contains a polycarbonate resin and a polyester resin having a polysiloxane structure at least in a polymer terminal or a repeating structural unit as a binder resin in the outermost layer, and the above-mentioned in the outermost layer. When the free silicone is 100 ppm or less, excellent electrophotographic characteristics are exhibited.

[3-1. Conductive support]
There is no particular limitation on the conductive support, but for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel, and conductive powder such as metal, carbon, and tin oxide are added to impart conductivity. A resin material, a resin, glass, paper, or the like on which a conductive material such as aluminum, nickel, or ITO (indium tin oxide) is deposited or applied on the surface is mainly used. These may be used alone or in combination of two or more in any combination and ratio. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Further, a conductive material having an appropriate resistance value may be used on a conductive support made of a metal material in order to control conductivity and surface properties and to cover defects.

Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.
The surface of the support may be smooth, or may be roughened by using a special cutting method or performing a polishing treatment. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

[3-2. Undercoat layer]
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin or a resin in which particles such as a metal oxide are dispersed is used. The undercoat layer may be a single layer or a plurality of layers.

  Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicon. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained. In addition, various particle sizes of metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is preferably 10 nm or more and 100 nm or less, and particularly 10 nm or more and 50 nm or less. preferable. This average primary particle size can be obtained from a TEM photograph or the like.

  The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. The binder resin used for the undercoat layer is epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, chloride resin. Cellulose esters such as vinylidene resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic resin, polyacrylamide resin, polyvinylpyrrolidone resin, polyvinylpyridine resin, water-soluble polyester resin, nitrocellulose Resin, cellulose ether resin, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate compound, zirconium The organic zirconium compound alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanium alkoxide compounds include known binder resins such as a silane coupling agent. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected. From the viewpoint of the stability of the dispersion and the coating property, the binder resin is usually 10% by mass or more, It is preferable to use in the range of 500 mass% or less.
The thickness of the undercoat layer is arbitrary as long as the effects of the present invention are not significantly impaired, but the viewpoint of improving the electrical characteristics, strong exposure characteristics, image characteristics, repeat characteristics, and coating properties during production of the electrophotographic photosensitive member. Therefore, it is usually 0.01 μm or more, preferably 0.1 μm or more, and usually 30 μm or less, preferably 20 μm or less. A known antioxidant or the like may be mixed in the undercoat layer. For the purpose of preventing image defects, pigment particles, resin particles and the like may be included.

[3-3. Photosensitive layer]
As a type of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer and are dispersed in a binder resin, a charge generation layer in which a charge generation material is dispersed in a binder resin, and a charge. A functional separation type (laminated type) composed of two layers of a charge transport layer in which a transport material is dispersed in a binder resin can be mentioned, but any type may be used.
In addition, as the laminated photosensitive layer, a charge generation layer and a charge transport layer are laminated in this order from the conductive support side, and a charge transport layer and a charge generation layer are laminated in this order. There are reverse laminated type photosensitive layers, and any of them can be adopted, but a forward laminated type photosensitive layer capable of exhibiting the most balanced photoconductivity is preferable.

(3-3-1. Multilayer type photosensitive layer)
3-3-1-1. In the case of a charge generation layer laminate type photoreceptor (function separation type photoreceptor), the charge generation layer is formed by binding a charge generation material with a binder resin.
Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments, but organic photoconductive materials are preferred, especially organic pigments. Is preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferable. When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When a metal-free phthalocyanine compound or a metal-containing phthalocyanine compound is used as the charge generation material, a photosensitive member having a high sensitivity to a laser beam having a relatively long wavelength, for example, a laser beam having a wavelength around 780 nm, is obtained. When an azo pigment such as diazo or trisazo is used, it is sufficient for white light, laser light having a wavelength around 660 nm, or laser light having a relatively short wavelength, for example, laser having a wavelength around 450 nm or 400 nm. A photosensitive member having a high sensitivity can be obtained.

  When an organic pigment is used as the charge generating material, a phthalocyanine pigment or an azo pigment is particularly preferable. The phthalocyanine pigment provides a photosensitive material with high sensitivity to a laser beam having a relatively long wavelength, and the azo pigment has a sufficient sensitivity to white light and a laser beam having a relatively short wavelength. , Each is excellent.

  When using a phthalocyanine pigment as a charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum or other metal or oxide thereof, halide, water Those having crystal forms of coordinated phthalocyanines such as oxides and alkoxides, and phthalocyanine dimers using oxygen atoms as bridging atoms are used. Particularly, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystalline Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 ° have the strongest peaks, and 26.2 ° have peaks Hydroxygallium phthalocyanine having a clear peak at 28.1 ° and a full width at half maximum W of 25.9 ° of 0.1 ° ≦ W ≦ 0.4 °, G-type μ-oxo -Gallium phthalocyanine dimer and the like are particularly preferable. Among these, D-type (Y-type) titanyl phthalocyanine is most preferable because it shows good sensitivity.

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state that can be put in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or they may be mixed in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that caused the condition. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

When an azo pigment is used as the charge generation material, various bisazo pigments and trisazo pigments are preferably used.
When an organic pigment is used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used. In this case, it is preferable to use a combination of two or more kinds of charge generating materials having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region. Among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are preferably used in combination. More preferred.

  The binder resin used for the charge generation layer is not particularly limited, but examples include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal type such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal, acetal, or the like. Resin, Polyarylate resin, Polycarbonate resin, Polyester resin, Modified ether type polyester resin, Phenoxy resin, Polyvinyl chloride resin, Polyvinylidene chloride resin, Polyvinyl acetate resin, Polystyrene resin, Acrylic resin, Methacrylic resin, Polyacrylamide resin, Polyamide Resin, polyvinyl pyridine resin, cellulosic resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride -Vinyl acetate-vinyl acetate copolymers such as vinyl acetate copolymers, hydroxy-modified vinyl chloride-vinyl acetate copolymers, carboxyl-modified vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, etc. Insulating resins such as polymers, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-alkyd resins, silicon-alkyd resins, phenol-formaldehyde resins, poly-N-vinylcarbazole, polyvinyl anthracene, polyvinyl And organic photoconductive polymers such as perylene. Any one of these binder resins may be used alone, or two or more thereof may be mixed and used in any combination.

Specifically, the charge generation layer is prepared by dispersing the halogen-substituted indium phthalocyanine of the present invention and other charge generation materials used in some cases in a solution obtained by dissolving the above-described binder resin in an organic solvent. Is applied on a conductive support (or an undercoat layer when an undercoat layer is provided).
The solvent used for preparing the coating solution is not particularly limited as long as it dissolves the binder resin. For example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, and aromatics such as toluene, xylene, and anisole. Group solvents, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene, chloronaphthalene, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, isopropanol, n-butanol, benzyl alcohol, etc. Alcohol solvents, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain or cyclic ketone solvents such as acetone, cyclohexanone, methyl ethyl ketone, ester solvents such as methyl formate, ethyl acetate, n-butyl acetate, methylene chloride ,Black Halogenated hydrocarbon solvents such as form, 1,2-dichloroethane, chain or cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, acetonitrile, dimethyl Aprotic polar solvents such as sulfoxide, sulfolane, hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, triethylamine and other nitrogen-containing compounds, ligroin and other mineral oils, water, etc. Can be mentioned. Any one of these may be used alone, or two or more of these may be used in combination. In addition, when providing the above-mentioned undercoat layer, what does not melt | dissolve this undercoat layer is preferable.

  In the charge generation layer, the mixing ratio (weight) of the binder resin and the charge generation material is usually 10 parts by mass or more, preferably 30 parts by mass or more, and usually 1000 parts by mass with respect to 100 parts by mass of the binder resin. Part or less, preferably 500 parts by mass or less, and the film thickness is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less. If the ratio of the charge generation material is too high, the stability of the coating solution may be reduced due to aggregation of the charge generation material, while if the ratio of the charge generation material is too low, the sensitivity as a photoreceptor may be decreased. There is.

  As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. At this time, it is effective to refine the particles to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

3-3-1-2. The charge transport layer of the charge transport layer laminated photoreceptor contains a charge transport material, and usually contains a binder resin and other components used as necessary. Specifically, such a charge transport layer is prepared by, for example, preparing a coating solution by dissolving or dispersing a charge transport material and a binder resin in a solvent. In addition, in the case of a reverse lamination type photosensitive layer, it can be obtained by coating and drying on a conductive support (or on the undercoat layer when an undercoat layer is provided).

[Charge transport material]
The charge transport material is not particularly limited, and any material can be used. Examples of charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, carbazole derivatives, indoles Derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives and multiple types of these compounds bind Or an electron donating substance such as a polymer having a group consisting of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable.
Any one of these charge transport materials may be used alone, or two or more thereof may be used in any combination. The charge transport layer is formed in such a form that these charge transport materials are bound to the binder resin. The charge transport layer may be composed of a single layer, or may be a stack of a plurality of layers having different constituent components or composition ratios.

[Binder resin]
The binder resin for the charge transport layer used in the electrophotographic photosensitive member of the present invention is <2. Polycarbonate resin or polyester resin having a polysiloxane structure in at least a part of the polymer terminal and the repeating structure. The binder resin may be a mixture of the above resin used in the present invention and other resins. Examples of other resins include butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylate resin, methacrylic ester resin, Polymers and copolymers of vinyl compounds such as acid ester resin, vinyl alcohol resin, ethyl vinyl ether, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin , Cellulose ester resin, phenoxy resin, silicon resin, silicon-alkyd resin, poly-N-vinylcarbazole resin, and the like. These binder resins can also be used after being crosslinked by heat, light or the like using an appropriate curing agent. Among these resins used in combination, a polyarylate resin is preferable, and from the viewpoint of cleaning properties, filming resistance and white stripe defects, a polyarylate resin represented by the above general formula (11) having no polysiloxane structure is used. More preferred is a polyarylate resin represented by the general formula (12).

  In the present invention, <2. In the case of a single-layer type photosensitive layer, the amount of other resins that may be used in combination with the resin described in detail in <Polycarbonate Resin or Polyester Resin Having Polysiloxane Structure at least Part of Polymer End and Repeated Structure> With respect to the total binder resin of the photosensitive layer, in the case of a laminated photosensitive layer, it is usually 0% by mass or more, preferably 50% by mass or more, and most preferably 75% by mass or more, based on the total binder resin of the charge transport layer On the other hand, it is usually 98% by mass or less, preferably 96% by mass or less, and more preferably 90% by mass or less. If the amount of other resins that may be used in combination is too small, sufficient film resistance cannot be obtained and electrical characteristics may be deteriorated. On the other hand, if the amount is too large, sufficient surface slipperiness may not be obtained. is there.

As for the ratio of the binder resin to the charge transport material, the charge transport material is used in a ratio of 20 parts by mass or more with respect to 100 parts by mass of the binder resin. Among these, 30 parts by mass or more is preferable from the viewpoint of residual potential reduction, and 40 parts by mass or more is more preferable from the viewpoint of stability and charge mobility when repeatedly used. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, the charge transport material is usually used at a ratio of 150 parts by mass or less. Among these, 110 parts by mass or less is preferable from the viewpoint of compatibility between the charge transport material and the binder resin, 80 parts by mass or less is more preferable from the viewpoint of printing durability, and 70 parts by mass or less is most preferable from the viewpoint of scratch resistance.
The thickness of the charge transport layer is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less, from the viewpoint of long life, image stability, and high resolution. Is in the range of 30 μm or less.

(3-3-2. Single-layer type photosensitive layer)
The single-layer type photosensitive layer is formed using a binder resin in order to ensure film strength, in the same manner as the charge transport layer of the multilayer photoconductor, in addition to the charge generation material and the charge transport material. Specifically, a charge generation material, a charge transport material, and various binder resins are dissolved or dispersed in a solvent to prepare a coating solution, and on a conductive support (or an undercoat layer when an undercoat layer is provided). It can be obtained by coating and drying.

The types of the charge transport material and the binder resin and the use ratios thereof are the same as those described for the charge transport layer of the multilayer photoreceptor. The charge generating material is further dispersed in the charge transport medium comprising these charge transport material and binder resin.
As the charge generation material, the same materials as those described for the charge generation layer of the multilayer photoreceptor can be used. However, in the case of a photosensitive layer of a single-layer type photoreceptor, it is necessary to sufficiently reduce the particle size of the charge generating material. Specifically, the range is usually 1 μm or less, preferably 0.5 μm or less.

If the amount of the charge generating material dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity cannot be obtained, but if it is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. It is used in the range of usually 0.5% by mass or more, preferably 1% by mass or more, and usually 50% by mass or less, preferably 20% by mass or less based on the whole layer-type photosensitive layer.
In addition, the usage ratio of the binder resin and the charge generation material in the single-layer type photosensitive layer is such that the charge generation material is usually 0.1 parts by weight or more, preferably 1 part by weight or more, based on 100 parts by weight of the binder resin. It is 30 mass parts or less, Preferably it is set as the range of 10 mass parts or less.

  The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less. Also in this case, known plasticizers for improving film formability, flexibility, mechanical strength, additives for suppressing residual potential, dispersion aids for improving dispersion stability, coatability Leveling agents and surfactants, for example, silicone oil, fluorine oil and other additives may be added so long as the effects of the present invention are not impaired.

[3-4. Other functional layers]
For the purpose of improving film forming properties, flexibility, coating properties, contamination resistance, gas resistance, light resistance, etc., in both the photosensitive layer and the layers constituting the photosensitive layer, both of the multilayer type photosensitive member and the single layer type photosensitive member. Additives such as well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds, and visible light shielding agents may be included.

In addition, for the purpose of reducing the frictional resistance and wear on the surface of the photoconductor, and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper, the surface layer is made of fluorine resin, polyethylene resin, or the like. The surface layer may contain particles or inorganic compound particles. Alternatively, a layer containing these resins and particles may be newly formed as a surface layer.
Furthermore, it goes without saying that a layer for improving electrical properties and mechanical properties, such as an intermediate layer such as a barrier layer, an adhesive layer and a blocking layer, and a transparent insulating layer, may be provided as necessary.

[3-5. Formation method of each layer]
Each layer constituting these photoreceptors is formed by immersing, coating, spraying, nozzle coating, bar coating, roll coating, blade coating, etc., on a support, a coating solution obtained by dissolving or dispersing a substance to be contained in a solvent. In this method, the coating and drying steps are sequentially repeated for each layer.

  There are no particular restrictions on the solvent or dispersion medium used in the preparation of the coating solution, but specific examples include alcohols such as methanol, ethanol, propanol and 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, dimethoxyethane and the like. Ethers, esters such as methyl formate and ethyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1, Chlorinated hydrocarbons such as 2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine , Nitrogen-containing compounds such as triethylenediamine, acetonitrile, N- methylpyrrolidone, N, N- dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide and the like. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds.

The amount of the solvent or dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriate so that the physical properties such as solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
For example, in the case of a charge transport layer layer of a single layer type photoreceptor and a function separation type photoreceptor, the solid content concentration of the coating solution is usually 5% by mass or more, usually 5% by mass or more, preferably 10% by mass or more, Moreover, it is 40 mass% or less normally, Preferably it is set as the range of 35 mass% or less. Further, the viscosity of the coating solution is usually in the range of 10 cps or more, preferably 50 cps or more, and usually 500 cps or less, preferably 400 cps or less.

In the case of a charge generation layer of a multilayer photoreceptor, the solid content concentration of the coating solution is usually 0.1% by mass or more, preferably 1% by mass or more, and usually 15% by mass or less, preferably 10% by mass. % Or less. The viscosity of the coating solution is usually 0.01 cps or more, preferably 0.1 cps or more, and usually 20 cps or less, preferably 10 cps or less.
Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.
The coating solution is preferably dried by touching at room temperature, followed by heating or drying in a temperature range of usually 30 ° C. or more and 200 ° C. or less for 1 minute to 2 hours, while still or blowing. Further, the heating temperature may be constant, or heating may be performed while changing the temperature during drying.

<4. Image forming apparatus>
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are disposed along the outer peripheral surface of the electrophotographic photosensitive member 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose an alternating current on a direct current.

The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary, but for example, monochromatic light with a wavelength of 780 nm,
The exposure may be performed with monochromatic light having a wavelength slightly shorter than 700 nm, monochromatic light with a short wavelength of 380 nm to 500 nm, or the like. Among these, it is preferable to use light having a short wavelength of 380 to 500 nm because the resolution becomes high. Among these, 405 nm monochromatic light is preferable.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicon resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.
The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as silicon resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.
The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are disposed to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, and a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( The electrophotographic photosensitive member cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 and other members are deteriorated, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

Specific embodiments of the present invention will be described in more detail below by way of examples. However, the present invention is not limited by these examples unless it exceeds the gist.
[Production of polyester resin]
Production Example 1 (Method for producing polyester resin (A))
Sodium hydroxide (5.03 g) and H ₂ O (238 ml) were weighed in a 300 mL beaker and dissolved with stirring. 2,3,5-trimethylphenol (0.17 g), 1,1-bis (4-hydroxy-3, methylphenyl) ethane (12.37 g), polysiloxane represented by the following general formula (1-1) Derivatives (average degree of polymerization of polysiloxane n = 32) (2.93 g) and benzyltriethylammonium chloride (0.14 g) were added in this order and dissolved with stirring, and then this aqueous alkaline solution was transferred to a 1 L reaction vessel.

Separately, a mixed solution of diphenyl ether-4,4′-dicarboxylic acid chloride (15.52 g) and dichloromethane (139 mL) was transferred into the dropping funnel.
While maintaining the external temperature of the reaction vessel at 20 ° C. and stirring the alkaline aqueous solution in the reaction vessel, the dichloromethane solution was dropped from the dropping funnel over 1 hour. After further stirring for 1 hour, dichloromethane (197 mL) was added and stirring was continued for 3 hours. Thereafter, stirring was stopped and the mixture was allowed to stand for 30 minutes, and then the organic layer was separated. This organic layer was washed twice with 0.1 N aqueous sodium hydroxide solution (238 mL), then washed twice with 0.1 N hydrochloric acid (238 mL), and further demineralized water (238 mL). Was washed twice. Dilution was performed by adding 345 ml of methylene chloride, and the precipitate obtained by pouring into isopropanol (2700 ml) was removed by filtration and dried to obtain the desired polyester resin (A). The obtained polyester resin (A) had a viscosity average molecular weight of 49,600, and the content of the polysiloxane structure in the polymer was 5.7% by mass. The structural formula of the obtained polyester resin (A) is shown below.

[Manufacture of polycarbonate]
Production Example 2 (Production Method of Polycarbonate Resin (C))
(1). Production of bisphenol C oligomer
・ 2,2-bis (4-hydroxy-3-methylphenyl) propane (= bisphenol C) 100 parts ・ sodium hydroxide 78 parts ・ water 922 parts ・ methylene chloride 412 parts The above mixture was charged into a reactor equipped with a stirrer. Stir. 87 parts of phosgene was blown into this to carry out the reaction. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the resulting oligomeric methylene chloride solution were as follows. Oligomer concentration (Note 1) 25.2% by mass
Terminal chloroformate group concentration (Note 2) 0.56 N Terminal phenolic hydroxyl group concentration (Note 3) 0.33 N (Note 1) Measured by evaporating to dryness.
(Note 2) Aniline hydrochloride obtained by reacting with aniline was subjected to neutralization titration with a 0.1 N aqueous sodium hydroxide solution.
(Note 3) Color development was measured colorimetrically at 546 nm when dissolved in methylene chloride, titanium tetrachloride and acetic acid solutions.
(2). Production of bisphenol P oligomer
・ 100 parts of 1,1-bis (4-hydroxyphenyl) -1-phenylethane (= bisphenol P)
・ 46 parts of sodium hydroxide
・ 1,000 parts of water
-Methylene chloride 420 parts The above mixture was charged into a reactor equipped with a stirrer and stirred. 87 parts of phosgene was blown into this to carry out the reaction. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the resulting oligomeric methylene chloride solution were as follows. Oligomer concentration 22.6% by mass
Terminal chloroformate group concentration 0.322 N Terminal phenolic hydroxyl group concentration 0.016 N * Measured in the same manner as in (1).
(3). Polycarbonate polymerization
-127.6 mL of bisphenol C oligomer solution obtained in (1)
-156.4 mL of bisphenol P oligomer solution obtained in (2)
・ 216 ml of methylene chloride
2-benzoyl-5- (3-polydimethylsiloxanepropoxy) phenol (average degree of polymerization of polysiloxane n = 37) 17.0 g
An aqueous solution prepared by dissolving 9.06 g of sodium hydroxide in 167 mL of water and 5.4 mL of a 2 wt% triethylamine aqueous solution were charged into a 2 L polymerization tank equipped with a stirrer, stirred at 20 ° C., and subjected to interfacial polymerization for 4 hours.

  Subsequently, 830 mL of water and 456 mL of methylene chloride were added and stirred for 30 minutes, and then the reaction solution was separated. The methylene chloride solution containing the polycarbonate resin was washed twice with a 0.1N aqueous sodium hydroxide solution, a 0.1N aqueous hydrochloric acid solution and demineralized water in sequence. The precipitate obtained by pouring the washed methylene chloride solution into 5 times (volume) of methanol was taken out by filtration and dried to obtain the desired terminal polysiloxane polycarbonate. This resin is referred to as polycarbonate resin (C).

  When the viscosity average molecular weight and the siloxane content were measured in the same manner as in Production Example 1, the viscosity average molecular weight of this resin was 32,900, and the siloxane content was 16.1% by mass. The structure of the obtained polycarbonate resin (C) is shown below.

  In the above formula, A has the following structure:

[Measurement of viscosity average molecular weight]
The viscosity average molecular weights of the polyester resins (A) and polycarbonate resins (C) obtained in Production Examples 1 and 2 were measured as follows. The obtained resin was dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 g / L. The flow time t ₀ of the solvent (dichloromethane) is 1.
The flow time t of the sample solution was measured in a constant temperature water bath set at 20.0 ° C. using an Ubbelohde capillary viscometer of 36.16 seconds. The viscosity average molecular weight (Mv) was calculated according to the following formula.

<Manufacture of photoconductor>
[Example 1]
On the aluminum cylinder having a mirror-finished outer diameter of 30 mm, length of 260.5 mm, and wall thickness of 0.75 mm, the following undercoat layer forming coating solution, charge generating layer forming coating solution, and charge transport layer The undercoat layer, the charge generation layer, and the charge transport layer are formed in such a manner that the forming coating solution is sequentially applied by a dip coating method, and the film thickness after drying is 1.3 μm, 0.4 μm, and 21 μm, respectively. A photoreceptor drum was obtained.

The undercoat layer forming coating solution was prepared as follows. Rutile type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were mixed using a Henschel mixer. The surface-treated titanium oxide obtained by mixing was dispersed by a ball mill in a mixed solvent having a methanol / 1-propanol weight ratio of 7/3 to obtain a surface-treated titanium oxide dispersed slurry. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula (B ) / Hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [following formula ( The compound represented by E)] has a composition molar ratio of 60% / 15% / 5% / 15% / 5% and is agitated and mixed with pellets of copolymerized polyamide to dissolve the polyamide pellets. Then, by ultrasonic dispersion treatment, the weight ratio of methanol / 1-propanol / toluene is 7/1/2, and the surface-treated titanium oxide / copolymerized polyamide. In a weight ratio of 3/1, to prepare a coating liquid for forming an undercoat layer having a solid concentration of 18.0%.

  The charge generation layer forming coating solution was prepared as follows. The coating solution for forming the load generation layer was prepared as follows. As a charge generation material, 20 parts of oxytitanium phthalocyanine shown in the X-ray diffraction spectrum of FIG. 1 and 280 parts of 1,2-dimethoxyethane were mixed, and pulverized with a sand grind mill for 1 hour for atomization dispersion treatment. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-. A binder solution obtained by dissolving in 85 parts of a mixture of methyl-2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution A for forming a charge generation layer.

  As a charge generation material, 20 parts of oxytitanium phthalocyanine shown in the X-ray diffraction spectrum of FIG. 2 and 280 parts of 1,2-dimethoxyethane were mixed, and pulverized with a sand grind mill for 4 hours for atomization dispersion treatment. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-. A binder solution obtained by dissolving in 85 parts of a mixture of methyl-2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution B for forming a charge generation layer.

The charge generation layer forming coating solution A and the charge generation layer forming coating solution B were mixed at a ratio of 6: 4 to prepare a charge generation layer forming coating solution used in this example.
Next, as a charge transport material, 40 parts by mass of a mixture consisting of a compound group of geometric isomers having a structure represented by the following formula (CTM1) as a main component, and 26 of the polyester resin (A) produced in Production Example 1 74 parts by mass of a polyester resin (B) (viscosity average molecular weight 41,000) having a repeating structure shown below by mass, without using a leveling agent, a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene) ) The mixture was mixed with 640 parts by mass to prepare a coating solution for forming a charge transport layer.

In the prepared photosensitive drum, the free silicone was measured as follows.
[Measurement of free silicone content in photoconductor]
1. Preparation of photoconductor drum 1) Determine the measurement dimensions so that the coating area is about 100cm2, and cut it out from the measurement position using a band saw and pipe cutter 2) Cut it into a 100mL beaker with an appropriate push-off cutter 3) For LC Add 20 mL of THF and apply ultrasonic treatment until the CT layer is completely dissolved. 4) Transfer to a 20 mL volumetric flask, make up with THF for LC, and stir.
2. Preparation of standard solution 1) About half of the THF for LC is put into a 20 mL volumetric flask, and weighed with an electronic balance to obtain the tare value.

2) Add a few drops (less than 20mg) of silicone oil with a Pasteur pipette, precisely weigh it, make up with THF for LC, and stir.
3) Add a solution of 2) to a 20 mL volumetric flask containing about half the amount of THF for LC and stir it with a 1 mL whole pipette, and use it as a measurement sample.
3. Measurement Perform GCMS measurement under the following conditions.
Equipment: Shimadzu QP-5050A
Column: ZB1-MS (0.25 μm ID × 0.25 μm F × 15 mL)
Carrier: Helium 90cm / min (3.9mL / min, 140kPa)
Vaporization room: 260 ° C
Constant temperature bath: 50 ° C. × 1 min → (50 ° C./min)→300° C. × 20 min
Mode: Splitless (sampling 1 min, split ratio 5)
IF: 300 ° C
MS: SIM mode (m / z = 221)
Injection volume: 1 μL
Calibration: External standard method measurement: n = 2 or more Calculation 1) Add the areas of the peaks (Rt = 4.2 to 5.7 for 10cs) according to the grade of silicone oil, and obtain the silicone oil concentration in the sample solution from the standard solution measurement value with one check amount.

2) The concentration in CTL is derived from the dilution rate of the sample solution, the area of the sample to be measured, and the coating thickness.
Using this measurement method, the amount of free silicone of the photoconductor prepared was measured and found to be 0.0 ppm or less.
Here, an image characteristic test was performed using the produced photosensitive drum.
The image characteristic test was performed using a color printer HP Color LaserJet 4650dn (cleaning blade, counter contact method) manufactured by Hewlett-Packard Company.

  The produced photosensitive drum and toner were mounted on a cyan process cartridge, and this cartridge was mounted on a printer. 10000 sheets of images are formed under a temperature of 10 ° C. and a humidity of 15% (sometimes referred to as LL), and ghost, fog, density reduction, filming (sometimes abbreviated as FL), and poor cleaning. (It may be abbreviated as CL) and film thickness reduction was evaluated. Furthermore, white streak defects were evaluated under an environment of a temperature of 25 ° C. and a humidity of 50%. The results are shown in Table-1.

[Film reduction test]
The film thickness of the initial photoconductor drum is measured with a Fisher Scope film thickness meter, and the film thickness after printing 10,000 sheets is also measured with the Fisher Scope film thickness meter. Asked.

[Other evaluations]
In addition, the cleaning was ranked as follows for poor cleaning (CL), filming (FL), leveling properties, and image quality. In addition, fog was performed by visual evaluation.

“Cleaning failure” item ◎: No cleaning failure occurred.
○: A slight cleaning failure can be confirmed, but it is practically usable.
Δ: The occurrence of defective cleaning can be confirmed, but at a practically usable level.
X: A level where there is a problem in practical use due to defective cleaning on the entire surface.

“Filming” item ◎: No filming occurred.
○: Slight filming can be confirmed, but practically usable level.
(Triangle | delta): Although generation | occurrence | production of filming can be confirmed, it is a level which can be used practically.
X: Filming occurs on the entire surface, and there is a practically problematic level.

“Leveling” item ○: Drum surface roughness is not observed, no problem △: Drum surface roughness is somewhat observed, but there is no practical problem ×: Drum surface roughness is observed, practical use “Image quality” item ◎: Image abnormality is not observed at all and is satisfactory.
◯: Slightly observed ghost, poor density under LL environment, dirt on the background, etc., but good for practical use.
(Triangle | delta): Although a ghost, the density | concentration defect in LL environment, the stain | pollution | contamination of a background part, etc. are observed, it is a level which can be used practically.
X: Ghost, density defect under LL environment, dirt on background, etc. are obvious and have practical problems.

“White streaks” item: No white streaks are seen on the halftone image, and there is no problem.
Δ: Some white streaks are seen on the halftone image, but there is no practical problem.
X: White stripes are clearly seen on the halftone image, which is problematic in practical use.
In the image forming apparatus using the electrophotographic photosensitive member of Example 1, there is no image deterioration such as ghost, fogging, density reduction, filming, poor cleaning, white streaks before image formation and after image formation of 10,000 sheets. A good image was obtained. In addition, no abnormal noise was generated during printing.

[Example 2]
Instead of the coating solution for forming the charge transport layer used in Example 1, 40 parts by mass of CTM1 as the charge transport material, 8.8 parts by mass of the polyester resin (A) produced in Production Example 1, and the polyester resin (B) (Viscosity average molecular weight 41,000) 91.2 parts by mass, without using a leveling agent, mixed with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (tetrahydrofuran 80% by mass, toluene 20% by mass), and a charge transport layer A forming coating solution was prepared. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Example 3]
Instead of the coating solution for forming the charge transport layer used in Example 1, 40 parts by mass of CTM1 as the charge transport material, 8.8 parts by mass of the polyester resin (A) produced in Production Example 1, and the polyester resin (B) (Viscosity average molecular weight 41,000) 91.2 parts by mass, leveling agent silicone oil (Shin-Etsu Chemical KF96-10CS) 0.01 part, mixed solvent of tetrahydrofuran and toluene (tetrahydrofuran 80% by mass, toluene 20% by mass) The mixture was mixed with 640 parts by mass to prepare a coating solution for forming a charge transport layer. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Example 4]
Instead of the coating solution for forming a charge transport layer used in Example 1, 40 parts by mass of CTM1 as a charge transport material and 75 parts by mass of the polyester resin (B) used in Example 1 were obtained in Production Example 2. 25 parts by mass of the polycarbonate resin (C), without using a leveling agent, is mixed with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene), and a coating liquid for forming a charge transport layer is prepared. Prepared. Using this coating solution,
A photoconductor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Example 5]
Instead of the charge transport layer forming coating solution used in Example 1, 40 parts by mass of CTM1 as the charge transport material, 100 parts by mass of the polyester resin (A) produced in Production Example 1, and no leveling agent were used. The mixture was mixed with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene) to prepare a coating solution for forming a charge transport layer. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Example 6]
Instead of the coating solution for forming the charge transport layer used in Example 1, 40 parts by mass of CTM1 and 75 parts by mass of polycarbonate resin (D) having the following repetitive structure were obtained as charge transport materials in Production Example 2. 25 parts by mass of the polycarbonate resin (C), without using a leveling agent, is mixed with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene), and a coating liquid for forming a charge transport layer is prepared. Prepared. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Comparative Example 1]
Instead of the charge transport layer forming coating solution used in Example 1, 40 parts by mass of CTM1 and 100 parts by mass of polyester resin (B) (viscosity average molecular weight 41,000) and a leveling agent are used as charge transport materials. Without being mixed with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (tetrahydrofuran 80 mass%, toluene 20 mass%), a coating solution for forming a charge transport layer was prepared. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Comparative Example 2]
Instead of the charge transport layer forming coating solution used in Example 1, 40 parts by mass of CTM1 as a charge transport material, 100 parts by mass of polyester resin (B) (viscosity average molecular weight 41,000), and silicone as a leveling agent The mixture was mixed with 0.05 part of oil (Shin-Etsu Chemical KF96-10CS) and 640 parts by weight of a mixed solvent of tetrahydrofuran and toluene (80% by weight of tetrahydrofuran, 20% by weight of toluene) to prepare a coating solution for forming a charge transport layer. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Comparative Example 3]
Instead of the charge transport layer forming coating solution used in Example 1, 40 parts by mass of CTM1 as a charge transport material, 8.8 parts by mass of polyester resin (A) produced in Production Example 1, polyester resin (B ) (Viscosity average molecular weight 41,000) was mixed in 91.2 parts by mass, 0.05 part of silicone oil as a leveling agent, and 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene). Then, a coating liquid for forming a charge transport layer was prepared. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

[Comparative Example 4]
Instead of the charge transport layer forming coating solution used in Example 1, 40 parts by weight of CTM1 as the charge transport material, 100 parts by weight of the polycarbonate resin (D), 0.05 parts of silicone oil as the leveling agent, tetrahydrofuran And a mixed solvent of toluene and toluene (80 mass% of tetrahydrofuran, 20 mass% of toluene) were mixed to prepare a coating solution for forming a charge transport layer. Using this coating solution, a photoreceptor was produced in the same manner as in Example 1. The image characteristic test was also performed in the same manner as in Example 1. The results are shown in Table-1.

  From the above results, by using the photoconductor with the free silicone amount of 100 ppm or less of the present invention, it is excellent in cleaning property, filming resistance, film resistance, and low density in low temperature and low humidity environment, and white stripes. It turns out that generation | occurrence | production of a defect is suppressed favorably.

Claims (7)

  The outermost surface layer of the electrophotographic photosensitive member contains a polycarbonate resin or a polyester resin having a polysiloxane structure at least at a part of the polymer terminal and the repeating structural unit, and the free silicone content in the outermost layer is 100 ppm or less. An electrophotographic photoreceptor, characterized in that   2. The electrophotographic photosensitive member according to claim 1, wherein the outermost layer of the photosensitive member contains a polyarylate resin having no polysiloxane structure.   3. The electron according to claim 1, wherein in the polycarbonate resin or polyester resin having the polysiloxane structure, a ratio of the polysiloxane structure in the polycarbonate resin or the polyester resin is 2% by mass or more and 10% by mass or less. Photoconductor. The electrophotographic photosensitive member according to claim 1, wherein the polyester resin having a polysiloxane structure has a repeating structure represented by the following general formula (11).

(In General Formula (11), R ^{1 to} R ⁸ are each independently a hydrogen atom, an alkyl group that may have a substituent having 1 to 20 carbon atoms, an alkoxyl group, or an optionally substituted aromatic group. X ¹ represents any one of a group, X ¹ represents a single bond, an alkylene group, —CR ⁹ R ¹⁰ —, an oxygen atom, or a sulfur atom, R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a carbon number of 1; ~ 20 alkyl groups,
Either an aromatic group which may have a substituent, or a group which forms a ring which may have a substituent when R ⁹ and R ¹⁰ are bonded to each other is shown. ) The electrophotographic photosensitive member according to claim 4, wherein the general formula (11) is represented by the following general formula (12).

(In General Formula (12), R ^{1 to} R ⁸ are each independently a hydrogen atom, an alkyl group which may have a substituent having 1 to 20 carbon atoms, an alkoxyl group, or an optionally substituted aromatic group. Each of R ⁹ and R ¹⁰ independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,
Either an aromatic group which may have a substituent, or a group which forms a ring which may have a substituent when R ⁹ and R ¹⁰ are bonded to each other is shown. )   6. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, and image exposure for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image. An electrophotographic cartridge comprising: a developing means for developing the electrostatic latent image with toner; and a transfer means for transferring the toner to a transfer target.   An electrophotographic photosensitive member according to any one of claims 1 to 5, a charging unit for charging the electrophotographic photosensitive member, and an exposing unit for forming an electrostatic latent image by exposing the charged electrophotographic photosensitive member; The image forming apparatus includes: a developing unit that develops the electrostatic latent image with toner; a transfer unit that transfers the toner to a transfer target; and a fixing unit that fixes the toner transferred to the transfer target. Image forming apparatus.

Images