JP2016161708A - Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that contains, in a photosensitive layer, a polycarbonate resin having a specific structure and a specific charge transport material, suppresses a change over time, and has excellent stability to various loads in an electrophotographic process, a process cartridge, and an image forming apparatus.SOLUTION: An electrophotographic photoreceptor contains, in a photosensitive layer, a polycarbonate resin having a repeating unit derived from a compound represented by the following formula (1) and containing a specific amount of specific structure unit, and a charge transport material having a specific structure.SELECTED DRAWING: None

Description

The present invention relates to an electrophotographic photosensitive member used for an electrophotographic printer, a copying machine, a multifunction machine, and the like, a cartridge made using the electrophotographic photosensitive member, and an image forming apparatus.
More specifically, the present invention relates to an electrophotographic photoreceptor using a polycarbonate resin having a specific structure and a photosensitive layer containing a specific charge transport material, a cartridge using the electrophotographic photoreceptor, and an image forming apparatus.

For the electrophotographic photoreceptor (hereinafter also referred to as “photoreceptor” where appropriate) that is the core of electrophotographic technology, an organic photoconductive material is used that has the advantage of being non-polluting and easy to form and manufacture. The photoreceptors used are widely used.
Electrophotographic image forming apparatuses are required to have higher image quality, higher speed, and higher durability year by year. Processes around the photoreceptor such as charging, exposure, development, and transfer have been improved to meet these requirements, but there are still many cases where improvement of the photoreceptor itself is still necessary.

  Polycarbonate resins used as binder resins for electrophotographic photoreceptors are widely used because of their excellent mechanical strength and electrical characteristics. As this production method, those produced by an interfacial method (interfacial polycondensation method) in which bisphenols and phosgene are reacted in a solution have been mainstream. On the other hand, as a method for producing polycarbonate resin as a general purpose engineering plastic, in addition to the solvent method, a melting method in which polycondensation reaction of bisphenol and carbonic acid diester is carried out by transesterification is widely used as an inexpensive production method. It is also known to use the obtained polycarbonate resin for a photosensitive layer of an electrophotographic photoreceptor (see Patent Document 1).

JP 2012-185206 A Japanese Patent Laid-Open No. 9-244278

The polycarbonate resin produced by the transesterification reaction as described above is superior in terms of the environment, such as not using an organic solvent with a large environmental load such as a halogen solvent, and not using phosgene in the polymerization process or the oligomer process. Mass production has merit in terms of cost, but there is a problem that bisphenol impurities are mixed.
Specifically, since the characteristics of the resin described in Patent Document 1 change due to deterioration with time, when used for the photosensitive layer of the photoreceptor, the product performance in terms of electrical characteristics depends on the storage state and manufacturing process. There was a problem of variation. In addition, when a photoconductor is manufactured by combining the resin described in Patent Document 1 with the charge transport material described in Patent Document 2, there is a problem of variation in product performance due to deterioration of the resin over time as described above. Although it can be solved, there are problems that the residual potential change during plus transfer is large and the universal hardness of the surface of the photoreceptor is low.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problem can be solved by a combination of a polycarbonate resin having a specific structure and a specific charge transport material, leading to the present invention. It was.
The gist of the present invention resides in the following <1> to <9>.
<1> A polycarbonate resin having a repeating unit derived from the compound represented by the following formula (1) in the photosensitive layer, wherein the content of the structural unit derived from the compound represented by the following formula (2) is An electrophotographic photoreceptor comprising: a polycarbonate resin having a content of 20 ppm to 2000 ppm in the resin; and at least one charge transport material represented by the following formula (A) or (B):

(In Formula (A), Ar ¹ and Ar ² each independently represent an aryl group which may have a substituent, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent Each independently represents a hydrogen atom, an alkyl group or an alkoxy group, and n represents an integer of 1 to 5.)

(In formula (B), R ⁵ and R ⁶ each independently represents an alkyl group.)
<2> Polycarbonate resin having a repeating unit derived from the compound represented by the following formula (1) in the photosensitive layer, wherein the content of the structural unit derived from the compound represented by the following formula (3) is An electrophotographic photoreceptor comprising: a polycarbonate resin having a content of 200 ppm to 7000 ppm in the resin; and at least one charge transporting material represented by the following formula (A) or (B):

(In Formula (A), Ar ¹ and Ar ² each independently represent an aryl group which may have a substituent, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent Each independently represents a hydrogen atom, an alkyl group or an alkoxy group, and n represents an integer of 1 to 5.)

(In formula (B), R ⁵ and R ⁶ each independently represents an alkyl group.)
<3> In the polycarbonate resin having a repeating unit derived from the compound represented by the formula (1), the content of the structural unit derived from the compound represented by the following formula (4) is 100 ppm or more and 2000 ppm or less in the resin. The electrophotographic photosensitive member according to <1> or <2>, wherein

<4> A polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) is produced by a transesterification reaction between a carbonic acid diester and an aromatic dihydroxy compound, <1> to <1>3> The electrophotographic photosensitive member according to any one of 3>.
<5> A polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) is produced by a transesterification reaction using cesium carbonate, cesium bicarbonate, or cesium hydroxide, <1 The electrophotographic photosensitive member according to any one of> to <4>.
<6> The photosensitive layer according to any one of <1> to <5>, wherein the photosensitive layer includes at least one compound represented by the following formula (C) or a compound represented by the following formula (D). Electrophotographic photoreceptor.

(In formula (C), R ^{7 to} R ⁹ each independently represents an alkyl group.)

(In formula (D), R ^{10 to} R ¹² each independently represents an alkyl group, and m represents an integer of 1 to 3.)
<7> The polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) includes a structural unit represented by the following formula (5), <1> to <6> The electrophotographic photosensitive member according to any one of the above.

<8> The electrophotographic photosensitive member according to any one of <1> to <7>, a charging device for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to electrostatic latent An electrophotographic photosensitive member comprising: an exposure device for forming an image; and at least one selected from the group consisting of a developing device for developing an electrostatic latent image formed on the electrophotographic photosensitive member cartridge.
<9> The electrophotographic photosensitive member according to any one of <1> to <7>, a charging device that charges the electrophotographic photosensitive member, and an electrostatic latent image formed by exposing the charged electrophotographic photosensitive member. An image forming apparatus comprising: an exposure device that forms a toner image; and a developing device that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

  According to the present invention, by combining a polycarbonate having a specific structure and a specific charge transport material, it is possible to obtain an electrophotographic photosensitive member that is less deteriorated with time and excellent in stability against various loads in an electrophotographic process. it can. In addition, the polycarbonate resin of the present invention can be mass-produced at a low cost and can be produced by an ester exchange reaction excellent in environmental aspects.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention.

Hereinafter, modes for carrying out the present invention (hereinafter, embodiments of the present invention) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. Further, the drawings to be used are for explaining the present embodiment, and do not represent the actual size ratio.
<About the polycarbonate resin used in the present invention>
The polycarbonate resin of the present invention has a repeating unit derived from the aromatic dihydroxy compound represented by the above formula (1) and has a repeating unit represented by the following formula (1) ′.

Furthermore, the structural unit derived from the compound represented by the following formula (2), at least one structural unit derived from the compound represented by the following formula (3), and the compound represented by the following formula (4) The structural unit derived from is contained in a specific amount.

  The polycarbonate resin of the present invention has at least repeating units derived from the compound represented by the formula (1), but the content thereof is represented by the formula (1) with respect to all repeating units derived from the dihydroxy compound. It is preferable that the repeating unit derived from a compound is 50 weight% or more, More preferably, it is 70 weight% or more, More preferably, it is 90 weight% or more. If the amount of the structural unit is excessively small, the stability of the photoreceptor coating solution tends to be poor.

  The polycarbonate resin of the present invention comprises at least one structural unit selected from a structural unit derived from the compound represented by the formula (2) or a structural unit derived from the compound represented by the formula (3). Includes a specific amount. Furthermore, the structural unit derived from the compound represented by said Formula (4) contains a specific amount. The amount of the structural unit derived from the compound represented by the formula (2), (3) or (4) contained in the polycarbonate resin of the present invention is liquid when alkali-hydrolyzed by the method described later. It is defined by the value measured by chromatography.

In the polycarbonate resin of the present invention, the content in the case of containing a structural unit derived from the compound represented by the formula (2) is 20 ppm or more and 2000 ppm or less, but the upper limit is preferably 1300 ppm or less, more preferably 1000 ppm or less. preferable. The lower limit is more preferably 200 ppm or more.
Further, the content in the case of containing the structural unit derived from the compound represented by the formula (3) is 200 ppm or more and 7000 ppm or less, and the upper limit is preferably 5000 ppm or less, more preferably 4500 ppm or less, More preferably, it is 4000 ppm or less. The lower limit is preferably 500 ppm or more, more preferably 1000 ppm or more, and further preferably 1500 ppm or more.

The content when the compound represented by the formula (4) is contained is 100 ppm or more and 2
The upper limit is more preferably 1000 ppm or less, and even more preferably 600 ppm. The lower limit is more preferably 200 ppm or more.
If the content of the structural unit derived from the compound represented by the formula (2) or (3) is too smaller than the above range, the entanglement with the charge transport material becomes weak, and the surface charge is injected into the photosensitive layer. It is thought that the deterrent effect is reduced. On the other hand, if the amount is more than the above range, the polymer hue may be deteriorated, gel-like substances or foreign matters insoluble in the solvent may be generated, and mechanical properties may be deteriorated.

Measurement of the structural unit derived from the compound represented by the formula (2), (3) or (4) in the polycarbonate resin by liquid chromatography is possible, for example, under the following conditions.
(Analysis conditions)
Liquid chromatography device: manufactured by Shimadzu Corporation
System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analytical column: YMC-Pack ODS-AM 75 mm × Φ4.6 mm
Oven temperature: 40 ° C
Detection wavelength: 280 nm
Eluent: A solution: 0.1% trifluoroacetic acid aqueous solution, B solution: acetonitrile
From A / B = 60/40 (vol%) to A / B = 95/5 (vol%)
Gradient in 25 minutes Flow rate: 1 mL / min
Sample injection volume: 20 μl
More specifically, a compound which is a structural unit derived from the compound represented by formula (2), (3) or (4) is observed at the following retention time under the above liquid chromatography conditions.

Compound represented by formula (4): 13.9 minutes Compound represented by formula (2): 15.9 minutes Compound represented by formula (3): 21 minutes Each compound is identified by the above retention time. The portion corresponding to the observed peak is fractionated, and ¹ H NMR, ¹³ C NMR, mass spectrometry (MS), infrared absorption spectrum (IR spectrum), etc. of the collected sample can be used.

(Molecular weight)
In the polycarbonate resin described above, the viscosity average molecular weight is arbitrary as long as the effects of the present invention are not significantly impaired, but preferably 10,000 or more, more preferably 20,000 or more, and the upper limit thereof is preferably 70,000. It is desirable that it is 000 or less, more preferably 50,000 or less. If the value of the viscosity average molecular weight is too small, the mechanical strength of the photosensitive layer may be insufficient, and if it is too large, the viscosity of the coating solution for forming the photosensitive layer may be too high and the productivity may decrease. is there. In addition, a viscosity average molecular weight can be measured by the method as described in an Example using an Ubbelohde type capillary viscometer etc., for example.

American Standards Test Methods (ASTM) E313 of polycarbonate resin according to the present invention
The yellow index (YI) defined by (measured according to JIS K 7105) is usually 20.0 or less, preferably 18.0 or less, more preferably 15.0 or less. If YI is too high, the color tone is deteriorated, the translucency is deteriorated, and the electrical characteristics are repeatedly deteriorated, which is not preferable. The mechanism by which YI increases is not always clear, but it is considered that one of the causes is that the bisphenol monomer remaining in the polymerization or in the resin partially changes to the quinone structure by air oxidation. It is remarkable when it is insufficient. In such a case, the deteriorated site functions as a charge trap, and may cause electrical characteristic defects such as accumulation of residual potential when repeatedly used.

  When the polycarbonate resin according to the present invention is used as a binder resin for a photosensitive layer of an electrophotographic photosensitive member, there is little deterioration in electrical characteristics when repeatedly used, and ozone resistance and memory characteristics due to transfer voltage are improved. . Although this mechanism is not always clear, the branched structural unit derived from the compound represented by the formula (2) or (3) strengthens the entanglement with the charge transporting substance, and the ozone gas or the surface charge in the layer. The effect of preventing injection into the skin is considered. In addition, when manufactured by the melting method, do not use a nitrogen atom-containing catalyst that causes deterioration of electrical properties when used repeatedly, and no chemically unstable specific end groups (chloroformate groups) are generated. Are considered to be factors of good electrical characteristics, ozone resistance characteristics and memory characteristics.

(Production method of polycarbonate resin)
There is no restriction | limiting in particular in the manufacturing method of the polycarbonate resin which concerns on this invention, It has a repeating unit derived from the compound represented by the said Formula (1), and also has a structure derived from the compound represented by the said Formula (2). Any method may be used as long as it can be produced so as to include a specific amount of a unit or a structural unit derived from the compound represented by the formula (3). Usually, the polycarbonate resin is obtained by polymerizing a dihydroxy compound component and a carbonate-forming compound component. The polycarbonate resin production method of the present invention includes a melt polycondensation method based on a transesterification reaction using a dihydroxy compound component containing the compound represented by the formula (1) and a carbonic acid diester as a carbonate-forming compound component ( Hereinafter, an interfacial polycondensation method (hereinafter referred to as an interfacial method) using a dihydroxy compound component containing the compound represented by the formula (1) and carbonyl chloride as a carbonate-forming compound component may be abbreviated as a melting method. May be abbreviated as). Among these, the content of the structural unit derived from the compound represented by the formula (2) or (3), and further the content of the structural unit derived from the compound represented by the formula (4) are specified amounts. The melting method is preferable because it can be easily controlled. Hereinafter, the case of manufacturing by a melting method will be described as an example.

(Aromatic dihydroxy compounds)
Specifically, the aromatic dihydroxy compound represented by the formula (1) is mainly used as the aromatic dihydroxy compound which is a raw material of the polycarbonate resin according to the present invention.

  Since the aromatic dihydroxy compound represented by the formula (1) has one methyl group adjacent to the hydroxyl group, the oxidation of the hydroxyl group is sterically blocked at the same time. Compared to the case where the groups are adjacent to each other, the methyl group does not become a steric hindrance with respect to the polymerization reaction, and the solubility of the polymer is high, the compatibility with the charge transporting material is high, and the electrical properties and mechanical properties are low. It is advantageous from the viewpoint.

The aromatic dihydroxy compound represented by the formula (1) may be used alone or may be copolymerized with another aromatic dihydroxy compound. In the case of copolymerization, the amount of the aromatic dihydroxy compound represented by the formula (1) is 50 mol% or more of the total copolymerization components, the viewpoint of the polymerization reaction, the solubility of the polymer, and the electrical characteristics. From the viewpoint of mechanical properties, it is preferably 70 mol% or more.
Examples of aromatic dihydroxy compounds that may be copolymerized are shown below.

  Among these, a polycarbonate structural unit represented by the following formula (5) is preferable as a copolymerization component from the viewpoint of availability.

(Carbonated diester)
In the case of the melting method, examples of the carbonic acid diester that is a raw material of the polycarbonate resin include compounds represented by the following general formula (6).

In General Formula (6), A ¹ and A ² are a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group. A ¹ and A ² may be the same or different from each other.
In addition, examples of the substituent for A ¹ and A ² include a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, Examples include ester groups, amide groups, nitro groups and the like.

Specific examples of the carbonic acid diester compound include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate.
Among these, diphenyl carbonate (hereinafter sometimes referred to as “DPC”) and substituted diphenyl carbonate are preferable. These carbonic acid diesters can be used alone or in admixture of two or more.

  These carbonic acid diesters are generally used in a ratio of 1.01 mol to 1.30 mol, preferably 1.02 mol to 1.20 mol, based on 1 mol of the dihydroxy compound. If the molar ratio of the carbonic acid diester is excessively small, the transesterification rate decreases, making it difficult to produce a polycarbonate resin having a desired molecular weight, or increasing the terminal hydroxyl group concentration of the resulting polycarbonate resin, resulting in thermal stability. Tend to get worse. In addition, if the molar ratio of the carbonic acid diester is excessively large, the reaction rate of the transesterification decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, and the residual amount of the carbonic acid diester compound in the resin. Increases, which may cause deterioration of electrical characteristics and odor.

  In the production of polycarbonate resin by the melting method, phosgene is not used in the polymerization step, and therefore, there is no chloroformate residue at the terminal, whereas in the production of polycarbonate resin by the interface method or the solution method, the chloroformate at the terminal is not present. The difference is that the mate residue and its modifying group remain.

(Transesterification catalyst)
Examples of the catalyst used in the production of the polycarbonate resin according to the present invention include a catalyst usually used in a transesterification method of a polycarbonate resin, and are not particularly limited.
In general, for example, basic compounds such as alkali metal compounds, alkaline earth metal compounds, beryllium compounds, magnesium compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds can be used. Among these, alkali metal compounds and alkaline earth metal compounds are preferable for practical use. These transesterification catalysts may be used alone or in combination of two or more.

The amount of transesterification catalyst used is usually in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻³ mol with respect to 1 mol of the wholly aromatic dihydroxy compound, but a polycarbonate resin excellent in molding characteristics and hue is used. In order to obtain, the amount of the transesterification catalyst is preferably 1.0 × 10 ⁻⁸ mol to 1 mol per 1 mol of the wholly aromatic dihydroxy compound when an alkali metal compound and / or an alkaline earth metal compound is used. It is in the range of × 10 ⁻⁴ mol, more preferably in the range of 1.0 × 10 ⁻⁸ mol to 1 × 10 ⁻⁵ mol, and particularly preferably in the range of 1.0 × 10 ⁻⁷ mol to 5.0 × 10. Within the range of ^-6 moles. If the amount is less than the above lower limit, the content of the structural unit derived from the compound represented by the formula (2), (3) or (4) is decreased, and polymerization necessary for producing a polycarbonate resin having a desired molecular weight. No activity can be obtained. On the other hand, when the amount is large, the polymer hue deteriorates, and the content of the structural unit derived from the compound represented by the formula (2), (3) or (4) becomes too large, and the gel is insoluble in the solvent. There is a possibility that an object or a foreign matter is generated, and the appearance defect and the mechanical properties of the polycarbonate resin are deteriorated.

Examples of the alkali metal compound include inorganic alkali metal compounds such as alkali metal hydroxides, carbonates and hydrogencarbonate compounds; organic alkali metal compounds such as salts with alkali metal alcohols, phenols and organic carboxylic acids. It is done. Here, as an alkali metal, lithium, sodium, potassium, rubidium, cesium etc. are mentioned, for example.
Among these alkali metal compounds, a cesium compound is preferable, and in particular, cesium carbonate, cesium hydrogencarbonate, or cesium hydroxide enables an appropriate degree of polymerization for use as a photoreceptor, and from the viewpoint of easy removal as a residual catalyst. preferable.

Examples of the alkaline earth metal compound include inorganic alkaline earth metal compounds such as alkaline earth metal hydroxides and carbonates; alkaline earth metal alcohols, phenols, salts with organic carboxylic acids, and the like. It is done. Here, examples of the alkaline earth metal include calcium, strontium, barium and the like.
Examples of the beryllium compound and magnesium compound include inorganic metal compounds such as metal hydroxides and carbonates; salts of the metals with alcohols, phenols, and organic carboxylic acids.

  Examples of basic boron compounds include sodium salts, potassium salts, lithium salts, calcium salts, magnesium salts, barium salts, strontium salts, and the like of boron compounds. Here, as the boron compound, for example, tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron, tributyl Examples include benzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron.

Examples of the basic phosphorus compound include trivalent phosphine compounds such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, and tributylphosphine, or derivatives thereof. And quaternary phosphonium salts.
Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide Sid, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2 -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

(Catalyst deactivator)
In the production of the polycarbonate resin according to the present invention by the melting method, a catalyst deactivator for neutralizing and deactivating the transesterification catalyst may be added after the transesterification reaction. The heat resistance and hydrolysis resistance of the polycarbonate resin obtained by such treatment are improved.
As such a catalyst deactivator, an acidic compound having a pKa of 3 or less, such as sulfonic acid and sulfonic acid ester, is preferable. Specifically, benzenesulfonic acid, p-toluenesulfonic acid, methyl benzenesulfonate, benzenesulfone Examples include ethyl acetate, propyl benzenesulfonate, butyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, propyl p-toluenesulfonate, and butyl p-toluenesulfonate.
Among these, p-toluenesulfonic acid and butyl p-toluenesulfonate are preferably used.

(Manufacturing process)
The polycarbonate resin production process by the melting method is to prepare a raw material mixed melt of an aromatic dihydroxy compound and a carbonic acid diester as raw materials (original preparation process), and the raw material mixed melt in the presence of a transesterification reaction catalyst. It is carried out by performing a polycondensation reaction in multiple stages using a plurality of reaction vessels in a molten state (polycondensation step). The reaction system may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system. As the reaction tank, a plurality of vertical stirring reaction tanks and, if necessary, at least one horizontal stirring reaction tank subsequent thereto are used. Usually, these reaction tanks are installed in series and processed continuously.

After the polycondensation step, the reaction is stopped, the unreacted raw materials and reaction by-products in the polycondensation reaction liquid are degassed and removed, the step of adding a heat stabilizer, mold release agent, colorant, etc., polycarbonate resin You may add suitably the process etc. which form in a predetermined particle size.
Next, each process of the manufacturing method will be described.

・ Preparation process Aromatic dihydroxy compound and carbonic acid diester compound used as raw materials for polycarbonate resin are usually batch-type, semi-batch type or continuous-type stirring tank type in an atmosphere of inert gas such as nitrogen and argon. It is prepared as a raw material mixed melt using an apparatus. For example, when bisphenol A is used as the aromatic dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester compound, the melt mixing temperature is usually selected from the range of 120 ° C. to 180 ° C., preferably 125 ° C. to 160 ° C.

Hereinafter, the case where bisphenol C represented by the formula (1) alone is used as the aromatic dihydroxy compound and diphenyl carbonate is used as the raw material as the carbonic acid diester compound will be described as an example.
Under the present circumstances, the ratio of an aromatic dihydroxy compound and a carbonic acid diester compound is adjusted so that a carbonic acid diester compound may become excess, and a carbonic acid diester compound is 1.01 mol-1 normally with respect to 1 mol of aromatic dihydroxy compounds. .30 mol, preferably 1.02 mol to 1.20 mol.

-Polycondensation process The polycondensation by the transesterification reaction of an aromatic dihydroxy compound and a carbonic acid diester compound is usually carried out continuously in a multistage system of two or more stages, preferably 3 to 7 stages. Specific reaction conditions for each stage are temperature: 150 ° C. to 320 ° C., pressure: normal pressure to 0.01 Torr (1.3 Pa), and average residence time: 5 minutes to 150 minutes.
In each multi-stage reactor, in order to more effectively remove monohydroxy compounds such as phenol as a by-product from the system as the transesterification progresses, the reaction temperature is increased stepwise in the above reaction conditions. Set to high vacuum.

  In particular, the reaction temperature in the final polymerization tank is usually 250 ° C to 330 ° C, preferably 270 ° C to 320 ° C, more preferably 280 ° C to 300 ° C. If the reaction temperature of the final polymerization tank is too low, the polycarbonate resin of the present invention has a content of a structural unit derived from the compound represented by the formula (2) or (3) or (4), There is a possibility that the polymerization reaction does not proceed sufficiently and only a polycarbonate having a low molecular weight can be obtained. On the other hand, if the reaction temperature of the final polymerization tank is too high, the polymer hue deteriorates, and the compound represented by the formula (2) or (3) and further the formula (4) possessed by the polycarbonate resin of the present invention. The content of the structural unit derived from is excessively increased, and a gel-like substance or a foreign substance insoluble in the solvent is generated, which may cause poor appearance and decrease the mechanical properties of the polycarbonate resin.

  The average residence time in the final polymerization tank is usually 5 minutes to 150 minutes, preferably 30 minutes to 120 minutes, and more preferably 60 minutes to 90 minutes. If the average residence time in the final polymerization tank is too short, the content of the structural unit derived from the compound represented by the formula (2) or (3) or (4) is decreased, and the polymerization reaction proceeds sufficiently. However, there is a possibility that only a polycarbonate having a low molecular weight can be obtained. On the other hand, if the average residence time in the final polymerization tank is too long, the polymer hue deteriorates, and the polycarbonate resin of the present invention has a compound represented by the above formula (2) or (3) or (4). There is a possibility that the content of the derived structural unit is excessively large, gel-like materials and foreign matters insoluble in the solvent are generated, and the appearance defect and the mechanical properties of the polycarbonate resin are deteriorated.

When the polycondensation step is performed in a multistage manner, usually, a plurality of reaction vessels including a vertical stirring reaction vessel are provided to increase the average molecular weight of the polycarbonate resin. The reaction tank is usually installed in 2 to 6 groups, preferably 4 to 5 groups.
Here, as a reaction tank, for example, a stirring tank type reaction tank, a thin film reaction tank, a centrifugal thin film evaporation reaction tank, a surface renewal type biaxial kneading reaction tank, a biaxial horizontal stirring reaction tank, a wet wall reaction tank, a free tank A perforated plate type reaction vessel that polycondenses while dropping, a perforated plate type reaction vessel with wire that polycondenses while dropping along a wire, and the like are used.

The types of stirring blades in the vertical stirring reaction tank include, for example, turbine blades, paddle blades, fiddler blades, anchor blades, full zone blades (manufactured by Shinko Environmental Solution Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), helical ribbon blades, twisted lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.), and the like.
Moreover, a horizontal stirring reaction tank means that the rotating shaft of a stirring blade is a horizontal type (horizontal direction). As a stirring blade of a horizontal stirring reaction tank, for example, a uniaxial stirring blade such as a disk type or a paddle type, HVR, SCR, N-SCR (manufactured by Mitsubishi Heavy Industries, Ltd.), Vivolak (Sumitomo Heavy Industries, Ltd.) )), Or biaxial stirring blades such as spectacle blades and lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.).

In addition, the transesterification catalyst used for the polycondensation of an aromatic dihydroxy compound and a carbonic acid diester compound may usually be prepared as a solution in advance. The concentration of the catalyst solution is not particularly limited, and is adjusted to an arbitrary concentration according to the solubility of the catalyst in the solvent. As the solvent, acetone, alcohol, toluene, phenol, water and the like can be appropriately selected.
When water is selected as the solvent for the catalyst, the nature of the water is not particularly limited as long as the type and concentration of impurities contained are constant, but usually distilled water or deionized water is preferably used.

The amount of bisphenol monomer remaining in the polycarbonate resin produced by this melting method is preferably 100 ppm or less, more preferably 50 ppm or less. The residual amount of phenol produced as a by-product is preferably 50 ppm or less, more preferably 30 ppm or less. If the bisphenol component remains excessively, it may cause coloring, and if the phenol remains excessively, it may cause odor.
Further, since deterioration of the binder resin directly leads to deterioration of the photoreceptor characteristics, an antioxidant as shown in the following formula (C) or formula (D) may be added to the resin.

(Manufacturing method by interface method)
The production method of the polycarbonate resin by the interfacial method is produced by a known method, but the polycarbonate resin obtained by the interfacial method is usually derived from the compound represented by the formula (2) or (3) and further (4). In some cases, the content of structural units is very small. Therefore, in order to obtain the polycarbonate resin of the present invention, a structural unit derived from the compound represented by the formula (2) or (3) or (4) is obtained by heat-treating the polycarbonate resin obtained by the interfacial method. The content can be controlled within a specific range. Any method may be used for the heat treatment. Specifically, a method of heating the polycarbonate resin in a tank by a batch method, a method of heating the polycarbonate resin in a tank by a continuous method, a method of heating the polycarbonate resin by an extruder, etc. Can be mentioned. Of these, heating by a single screw extruder or a twin screw extruder is more preferable, and heating by a twin screw extruder with a vent port is more preferable. The heat treatment temperature is preferably 200 ° C to 400 ° C, more preferably 260 ° C to 390 ° C, further preferably 270 ° C to 380 ° C, and most preferably 280 ° C to 370 ° C as the polycarbonate resin temperature. When this polycarbonate resin temperature is too low, the content of the structural unit derived from the compound represented by the formula (2) or (3) or (4) in the polycarbonate resin of the present invention is small, while the temperature is high. If it is too high, the polymer hue deteriorates, and the content of the structural unit derived from the compound represented by the formula (2) or (3) or (4) in the polycarbonate resin of the present invention increases. It is not preferable.

The polycarbonate resin temperature is the temperature of the polycarbonate resin at the exit of the extruder if it is an extruder, and the temperature of the polycarbonate resin in the tank if it is a reaction tank. The heat treatment time is preferably 0.5 minutes to 2 hours, more preferably 1 minute to 1 hour, further preferably 1.5 minutes to 30 minutes, and most preferably 2 minutes to 10 minutes. When the heat treatment time is too short, the content of the structural unit derived from the compound represented by the above formula (2) or (3) or (4) in the polycarbonate resin of the present invention is reduced. If the time is too long, the polymer hue deteriorates, and any of the content of the structural unit derived from the compound represented by the above formula (2) or (3) or (4) in the polycarbonate resin of the present invention. Too much and not preferable. In the case of heat treatment by an extruder, the heat treatment time is calculated from the extrusion speed and the volume in the barrel.

<Regarding the charge transport material used in the present invention>
In the present invention, at least one kind of charge transport material represented by the following formula (A) or (B) is contained in the photosensitive layer.
(Charge transport material (A))

In the formula (A), Ar ¹ and Ar ² each independently represents an aryl group which may have a substituent, specifically, a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, or the like. Can be given. Among these, from the viewpoint of charge transport ability, a phenyl group and a naphthyl group are more preferable, and a phenyl group is still more preferable. Examples of the substituent that Ar ¹ and Ar ² may have include an alkyl group, an aryl group, an alkoxy group, and a halogen atom. Specifically, examples of the alkyl group include a methyl group, an ethyl group, and n-propyl. Groups, linear alkyl groups such as n-butyl group, branched alkyl groups such as isopropyl group and ethylhexyl group, and cyclic alkyl groups such as cyclohexyl group. The aryl group may have a substituent. Examples of the alkoxy group include linear alkoxy groups such as a methoxy group and an ethoxy group, branched alkoxy groups such as an isopropoxy group and an ethylhexyloxy group, and cyclic groups such as a cyclohexyloxy group. It has a fluorine atom such as an alkoxy group, a trifluoromethoxy group, a pentafluoroethoxy group, or a 1,1,1-trifluoroethoxy group. That an alkoxy group, and examples of the halogen atom fluorine atom, chlorine atom and bromine atom. Among these, an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are more preferable from the viewpoint of handling at the time of production, and 1 carbon atom is preferable from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member. More preferred are ˜6 alkyl groups. The number of substituents may be 1 to 5 when Ar ¹ or Ar ² is a phenyl group, but it is preferably 1 to 2 or not having a substituent in view of the versatility of the production raw material. From the viewpoint of the characteristics of the photoreceptor, it is more preferable that one or no substituent is present. Further, when Ar ¹ and Ar ² are naphthyl groups, it is preferable that the number of substituents is 2 or less or no substituents, more preferably no substituents, because of the versatility of the production raw materials. It is.

In formula (A), R ¹ and R ² each independently represents an alkyl group. The carbon number of the alkyl group is 6 or less, preferably 4 or less, and particularly preferably 3 or less. Specific examples include linear alkyl groups such as methyl group, ethyl group, and propyl group, branched alkyl groups such as isopropyl group, tertbutyl group, and isobutyl group, and cyclic alkyl groups such as cyclohexyl group and cyclopentyl group. Of these, a methyl group is most preferable from the viewpoint of synthesis. Further, the substituents may be bonded to each other to form a ring. For example, two alkyl groups may be condensed to form a cycloalkyl group or an ester bridge to form a lactone or the like.

The substitution positions of R ¹ and R ² are preferably ortho positions relative to the nitrogen atom from the viewpoint of light fatigue, para positions are preferable from the viewpoint of electrical characteristics, and meta positions are preferable from the viewpoint of solubility. From the viewpoint of crack resistance, R ¹ and R ² are preferably ortho or para with respect to the nitrogen atom. The number of alkyl groups which R ¹ and R ² represented by n have is 1 or more and 5 or less, preferably 1 or more and 2 or less, more preferably 1 with respect to one benzene ring.

In formula (A), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. Specifically, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, n -Linear alkyl groups such as butyl groups, branched alkyl groups such as isopropyl groups and ethylhexyl groups, and cyclic alkyl groups such as cyclohexyl groups, and alkoxy groups include methoxy groups, ethoxy groups, and n-propoxy groups. And a straight-chain alkoxy group such as an n-butoxy group, and a branched alkyl group such as an isopropoxy group and an ethylhexyloxy group. Among these, a hydrogen atom, a C1-C8 alkyl group, and a C1-C8 alkoxy group are preferable from the versatility of a manufacturing raw material, and a hydrogen atom and a C1-C6 from the surface of the handleability at the time of manufacture are preferable. More preferred are alkyl groups having 1 to 6 carbon atoms, and more preferred are hydrogen atoms and alkyl groups having 1 to 2 carbon atoms from the viewpoint of light attenuation characteristics as an electrophotographic photoreceptor, and charge as a charge transport material. From the viewpoint of transport ability, a hydrogen atom is particularly preferable.

  Specific examples of the structure of the charge transport material represented by the formula (A) are shown below, but the structure is not limited to the following structure without departing from the concept of the present invention.

  (Charge transport material (B))

In formula (B), R ⁵ and R ⁶ each independently represents an alkyl group. The alkyl group has 5 or less carbon atoms, preferably 3 or less carbon atoms in consideration of durability against repeated use when used as an electrophotographic photoreceptor and durability to ozone. Specific examples include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Among them, a methyl group is preferable. The substitution position of R ⁵ and R ⁶ is preferably para to the nitrogen atom from the viewpoint of mobility as a charge transport material, and particularly preferably substituted at the methyl or para position.

  Specific examples of the structure of the charge transport material represented by the formula (B) are shown below, but the structure is not limited to the following structure without departing from the concept of the present invention.

<Electrophotographic photoreceptor>
Next, constituent elements of the photoreceptor will be described.
The photoreceptor is provided with an anodized layer, a conductive layer, and an undercoat layer on a conductive support, if necessary, on which a single layer type or a laminated type photosensitive layer is provided, and further a protective layer if necessary. Is built.
For the conductive support, the anodic oxide layer, and the undercoat layer, for example, known examples disclosed in JP-A-2007-293319 can be used.

(Photosensitive layer)
As the 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. Examples include 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. The photosensitive layer of the electrophotographic photosensitive member used in the present invention is of any type. May be.

In addition, as the laminated photosensitive layer, a charge-generating layer and a charge transport layer are laminated in this order from the conductive support side, and conversely, a charge transport layer and a charge generation layer are formed from the conductive support side. There are reverse laminated photosensitive layers provided in order, and any of them can be adopted, but a forward laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.
In the electrophotographic photoreceptor of the present invention, a polycarbonate resin having a structure represented by the above formula (1) obtained by the melting method described in detail above is used as a binder resin in the photosensitive layer. The binder resin may be used in any layer, but is usually in the charge transport layer of the multilayer photosensitive layer or in the single layer photosensitive layer, preferably in the charge transport layer of the multilayer photosensitive layer. used.

The charge transport layer in which the binder resin is preferably used may be a plurality of layers, in which case any layer may be contained. The charge transport material represented by the formula (A) or the formula (B) is used in the charge transport layer of the multilayer photosensitive layer or in the single layer type photosensitive layer. It is preferably contained in the same layer as the polycarbonate resin having the structure.
The binder resin may be used in combination with a resin other than the polycarbonate resin having the structure represented by the above formula (1) obtained by the melting method.

(Laminated photosensitive layer)
-Charge generation layer As the charge generation layer, a known example, for example, disclosed in JP-A-2007-293319 can be used.
-Charge transport layer The charge transport layer of the multilayer photoconductor contains a charge transport material, a binder resin, and other components used as necessary. Specifically, such a charge transport layer is prepared by dissolving or dispersing the charge transport material of the present invention, the polycarbonate resin of the present invention as a binder resin, and additives in a solvent to prepare a coating solution. Applying and drying on the charge generation layer in the case of the forward lamination type photosensitive layer and on the conductive support in the case of the reverse lamination type photosensitive layer (on the undercoat layer if an undercoat layer is provided). Can be obtained.

  As the charge transport material, other known charge transport materials may be used in combination with the charge transport material represented by the above-described formulas (A) and (B). When other charge transport materials are used in combination, the kind thereof is not particularly limited. For example, carbazole derivatives, aromatic amine derivatives, styryl derivatives, enamine derivatives, butadiene derivatives, and those in which a plurality of these derivatives are bonded are preferable.

  From the viewpoint of electrical properties, the weight of the charge transport material containing the charge transport material represented by the formula (A) or the formula (B) with respect to 100 parts by weight of the binder resin is usually 40 parts by weight or more, preferably 50 weights. Part or more, more preferably 55 parts by weight or more, and from the viewpoint of crack resistance and wear resistance, it is usually 150 parts by weight or less, preferably 120 parts by weight or less, more preferably 100 parts by weight or less.

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.
Both the layered type photoreceptor and the single layer type photoreceptor have a film forming property, flexibility, coating property, contamination resistance, gas resistance, storage stability, light resistance, etc. on the photosensitive layer or each layer constituting the photosensitive layer. For the purpose of improving, additives such as well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds, leveling agents, visible light shading agents and the like may be contained.
As the antioxidant, a compound represented by the following formula (C) or formula (D) is particularly preferable.

In the formula (C), R ^{7 to} R ⁹ each independently represents an alkyl group, and a typical structure includes a compound of C- (1).

In the formula (D), R ^{10 to} R ¹² are each independently an alkyl group, m represents an integer of 1 to 3, and a typical structure is a compound of D- (1).

(Other functional layers)
Further, in both the laminated type photoreceptor and the single layer type photoreceptor, the photosensitive layer formed by the above procedure may be the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer and used as the surface layer. Good. For example, a protective layer may be provided for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to discharge products generated from a charger or the like. As the protective layer, known ones such as a curable protective layer such as a photo-curing type, a thermosetting type, and an electron beam curable type, and a protective layer in which an inorganic filler is dispersed can be used.

(Method for forming each layer)
Each layer constituting the above-described photoreceptor is formed by dip coating, spray coating, nozzle coating, bar coating, roll coating, blade coating on a conductive support obtained by dissolving or dispersing a substance to be contained in a solvent. It is formed by repeating a coating / drying step sequentially for each layer by a known method such as coating.

  The polycarbonate resin of the present application may be used alone or in combination with other resins. Examples of binder resins that may be mixed include polymers and copolymers of vinyl compounds such as butadiene resins, styrene resins, vinyl acetate resins, acrylic ester resins, methacrylic ester resins, vinyl alcohol resins, and ethyl vinyl ethers, Polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicon resin, silicon-alkyd resin, poly-N-vinylcarbazole resin, etc. Can be mentioned. Of these, polyester resins and polyarylate resins are preferred.

  There is no particular limitation on the solvent or dispersion medium used for the preparation of the coating liquid containing the polycarbonate resin according to the present invention, but specific examples include tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, dimethoxymethane, dimethoxyethane. , Ethers such as anisole, esters such as methyl formate and ethyl acetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone and 4-methoxy-4-methyl-2-pentanone, and aromatic hydrocarbons such as benzene, toluene and xylene Chlorinated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine , Isopropanol amino , 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. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds. Moreover, a non-halogen solvent is preferable from the viewpoint of reducing environmental burden.

(Manufacturing method of coating solution)
There is no restriction | limiting in the manufacturing method of the coating liquid for photosensitive layers which concerns on this invention. A coating solution is obtained by dissolving or dispersing a substance to be contained in the layer to be formed in a solvent. For example, in the case of a laminated photosensitive layer containing the polycarbonate resin according to the present invention, it can be produced by the following method. That is, charge transport material, polycarbonate resin, binder resin to be used together as necessary, additives, etc. are stirred and dissolved in an organic solvent at room temperature or while heating, and filtered with an optional filter as necessary. Adjust the liquid. At this time, when insoluble fine particles are added for the purpose of improving the lubricity and releasability of the photosensitive layer, the dispersion may be prepared by an appropriate dispersing means.

<Process cartridge, image forming apparatus>
Next, a process cartridge and an image forming apparatus having the electrophotographic photosensitive member 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 photosensitive member 1 is not particularly limited as long as it is the above-described electrophotographic photosensitive member. In FIG. 1, as an example, a drum-shaped photosensitive member in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. Showing the body. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 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. As the charging device, a corona charging device such as a corotron or a scorotron, a direct charging device (contact type charging device) for charging a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and the like are often used. Examples of the direct charging device include a charging roller and a charging brush. 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. For example, if exposure is performed with monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength of 600 nm to 700 nm, slightly shorter wavelength, monochromatic light with a wavelength of 380 nm to 500 nm, or the like. Good.

  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. This replenishing device is configured to be able to replenish toner T from a container such as a bottle or a process 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 a 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 disposed so as 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. The upper and lower fixing members 71 and 72 are known heat fixings such as 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, or 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 silicon 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 an arbitrary method such as heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

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 be configured to perform, 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, 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 are combined with one or two or more for an integrated electrophotography. It may be configured as a process cartridge (hereinafter referred to as “cartridge” as appropriate), and this 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. For example, the electrophotographic photosensitive member 1, the charging device 2, the developing device 4, the transfer device 5, and the integrated cartridge incorporating the cleaning device 6, or the electrophotographic photosensitive member 1, the charging device 2, and the cleaning device 6 are integrated. There is a type in which a cartridge is used and the developing device 4 is a separate cartridge. In these cartridges, for example, when the electrophotographic photosensitive member 1 is deteriorated or the toner in the developing device 4 is consumed and lost, the cartridge is removed from the image forming apparatus main body, and another new cartridge is removed. By attaching to the main body, maintenance and management of the image forming apparatus are facilitated.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example, unless the summary is exceeded. In the following description, “part” represents “part by mass”.

<Viscosity average molecular weight>
A polycarbonate resin is dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 g / L. The flow time t of the sample solution is measured in a constant temperature water bath set at 20.0 ° C. using an Ubbelohde capillary viscometer with a flow time t0 of the solvent (dichloromethane) of 136.16 seconds. The viscosity average molecular weight Mv is calculated according to the following formula.
a = 0.438 × ηsp + 1 ηsp = t / t0−1
b = 100 × ηsp / C C = 6.00 (g / L)
η = b / a
Mv = 3207 × η1.205

<Yellow index of polycarbonate resin (YI)>
The yellow index (YI) was measured with a spectrocolorimeter (CM-3700d manufactured by Minolta Co., Ltd.) using the molded body molded in (1). The smaller the value, the better the color tone.

<Quantification of structural unit derived from compounds represented by formulas (2), (3) and (4)>
After 0.5 g of polycarbonate resin is dissolved in 5 ml of methylene chloride, 45 ml of methanol and 5 ml of 25% by weight aqueous sodium hydroxide solution are added and stirred at 70 ° C. for 30 minutes. The obtained solution is analyzed by liquid chromatography, and the structural units derived from the compounds represented by formula (2), formula (3) and formula (4) are quantified. The quantification was performed using a calibration curve created by quantification of the repeating unit represented by the formula (1).
Liquid chromatography measurement was performed by the following method.

Device: manufactured by Shimadzu Corporation System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analytical column: YMC-Pack ODS-AM 75 mm × Φ4.6 mm
Oven temperature: 40 ° C
Detection wavelength: 280 nm
Eluent: A solution: 0.1% trifluoroacetic acid aqueous solution, B solution: acetonitrile
From A / B = 60/40 (vol%) to A / B = 95/5 (vol%)
Gradient in 25 minutes Flow rate: 1 mL / min
Sample injection volume: 20 μl

Moreover, the compound 2 which is a structural unit derived from the compound represented by the formula (2), the compound 3 which is a structural unit derived from the compound represented by the formula (3), and the formula (4) Compound 4, which is a structural unit derived from the above compound, was observed at the following retention time under the above liquid chromatography conditions.
Compound represented by formula (4): 13.9 minutes Compound represented by formula (2): 25.9 minutes Compound represented by formula (3): 3:21 minutes

For identification of each compound, a portion corresponding to the peak observed at the above retention time was fractionated, and ¹ H NMR, ¹³ C NMR, two-dimensional NMR method, mass spectrometry (MS), infrared absorption of the sample collected. It was carried out by the spectral method (IR spectrum).
The compound 4 represented by the formula (4) was identified from the molecular weight of the sample collected by mass spectrometry, the NMR spectrum signal, and the signal derived from the aldehyde in the IR spectrum. The compound 2 represented by the formula (2) was identified from the molecular weight of the sample collected by mass spectrometry, the NMR spectrum signal, and the signal derived from the carboxylic acid in the IR spectrum. The compound 3 represented by the formula (3) was identified from the molecular weight of the sample collected by mass spectrometry and each NMR spectrum signal.

<Manufacture of polycarbonate resin>
(Production Example 1) Synthesis of PC1 (BPC homopolymer) (melting method)
37.60 kg (about 147 mol) of 2,2-bis (4-hydroxy-3-methylphenyl) propane (hereinafter sometimes abbreviated as “BPC”) (Honshu Chemical Co., Ltd.) and diphenyl carbonate (DPC) 32 The mixture was prepared by adding an aqueous solution of cesium carbonate to 20 kg (about 150 mol) so that the cesium carbonate was 2 μmol per 1 mol of BPC. Next, the mixture was charged into a first reactor having an internal volume of 200 L equipped with a stirrer, a heating medium jacket, a vacuum pump, and a reflux condenser.

Next, the operation of depressurizing the inside of the first reactor to 1.33 kPa (10 Torr) and then restoring the pressure to the atmospheric pressure with nitrogen was repeated 5 times, and the inside of the first reactor was replaced with nitrogen. After nitrogen substitution, the internal temperature of the first reactor was gradually raised through a heat medium having a temperature of 230 ° C. through the heat medium jacket to dissolve the mixture. Then, the stirrer was rotated at 300 rpm, the temperature in the heating medium jacket was controlled, and the internal temperature of the first reactor was kept at 220 ° C. The pressure in the first reactor was 101.3 kPa (760 Torr) in absolute pressure over 40 minutes while distilling off phenol produced as a by-product by the oligomerization reaction of BPC and DPC performed in the first reactor. To 13.3 kPa (100 Torr).

Subsequently, a transesterification reaction was performed for 80 minutes while maintaining the pressure in the first reactor at 13.3 kPa and further distilling off the phenol.
Thereafter, the inside of the system was restored to the absolute pressure of 101.3 kPa with nitrogen, the gauge pressure was increased to 0.2 MPa, and the oligomer in the first reactor was passed through a transfer pipe heated to 200 ° C. or higher in advance. Was pumped to the second reactor. The second reactor had an internal volume of 200 L, was equipped with a stirrer, a heat medium jacket, a vacuum pump and a reflux condenser, and the internal pressure was controlled to atmospheric pressure and the internal temperature was controlled to 240 ° C.

  Next, the oligomer fed into the second reactor was stirred at 38 rpm, the internal temperature was raised with a heating medium jacket, and the inside of the second reactor was absolute pressure from 101.3 kPa to 13.3 kPa over 40 minutes. The pressure was reduced to. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and phenol distilled out was removed out of the system. Further, the temperature was continuously raised, and after the absolute pressure in the second reactor reached 70 Pa (about 0.5 Torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reactor was 285 ° C. The polycondensation reaction was completed when the stirrer of the second reactor reached a predetermined stirring power.

  Subsequently, the inside of the second reactor was restored to an absolute pressure of 101.3 kPa with nitrogen and increased to a gauge pressure of 0.2 MPa, and the polycarbonate resin was extracted in the form of a strand from the bottom of the tank of the second reactor. The additive represented by AD-2 was added to the resin in an amount of 0.1% by weight, and pelletized using a rotary cutter while cooling in a water bath. The resulting polycarbonate resin had a viscosity average molecular weight of 24,700 and a YI of 7.5.

(AD-2)
(Production Example 2) Synthesis of PC2 (BPC / BPA copolymer) (melting method)
In Production Example 1, instead of BPC 37.60 kg, BPC 33.77 kg and 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as “BPA”) 5.30 kg (BPC: BPA = 85:15 (mol ratio)) was used in the same manner as in Production Example 1 except that polycarbonate resin PC2 was produced. The viscosity average molecular weight was 26,100, and YI was 15.0.

(Comparative Production Example 1) Synthesis of PC3 (BPC homopolymer) (interface method)
A BPC homopolymer by an interfacial method was produced by the method described in Example 1 of JP 2010-43201 A. The viscosity average molecular weight was 33,000.
(Comparative Production Example 2) Synthesis of PC4 (BPC / BPA copolymer) (interface method)
Following the method described in Example 1 of JP 2010-43201 A, a BPC / BPA copolymer (BPC at the time of charging: BPA = 80: 20 (mol ratio)) by an interface method was produced. The viscosity average molecular weight was 22,000.

  The content (ppm) of the structural unit derived from the compounds represented by the formulas (2), (3) and (4) of the polycarbonate resins PC1 to PC4 is quantified by the above method. Is shown.

<Manufacture and evaluation of photoconductor>
[Example 1]
A coating solution for a photoreceptor was produced as follows.
[Manufacture of coating solution for forming undercoat layer]
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. Composition of the dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam / bis (4-amino-3-methylcyclohexyl) methane / hexamethylenediamine / decamethylenedicarboxylic acid / octadecamethylenedicarboxylic acid The copolyamide pellets with a molar ratio of 60% / 15% / 5% / 15% / 5% are stirred and mixed with heating to dissolve the polyamide pellets, and then subjected to ultrasonic dispersion treatment. To form a subbing layer with a solid content concentration of 18.0%, containing a methanol / 1-propanol / toluene weight ratio of 7/1/2 and a surface-treated titanium oxide / copolymerized polyamide at a weight ratio of 3/1. A coating solution was prepared.

[Manufacture of coating solution for forming charge generation layer]
The charge generation layer forming coating solution was prepared as follows. As a charge generation material, 20 parts of Y-type (also known as D-type) oxytitanium phthalocyanine and 1,2- 1, which show a strong diffraction peak at 27.3 ° in Bragg angle (2θ ± 0.2) in X-ray diffraction by CuKα ray 280 parts of 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 “Denka Butyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-methyl. A binder liquid obtained by dissolving in 85 parts of 2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution L for forming a charge generation layer.

[Manufacture of coating solution for charge transport layer formation]
The charge transport layer forming coating solution was prepared as follows. 50 parts of the charge transport material CT-1 below, 100 parts of the polycarbonate resin PC1 as an antioxidant, 2 parts by weight of the following AD-1 and 0.05 part of silicone oil as a leveling agent in tetrahydrofuran (hereinafter referred to as THF as appropriate). Abbreviation) and toluene (hereinafter abbreviated as TL as appropriate) (THF 80 wt%, TL)
20 wt%) was mixed with 640 parts to prepare a coating solution for forming a charge transport layer.

[Manufacture of photoconductor]
The undercoat layer-forming coating solution obtained as described above was applied on a polyethylene terephthalate sheet having aluminum deposited on the surface with a wire bar so that the film thickness after drying was about 1.3 μm, and dried at room temperature. An undercoat layer was provided.
Subsequently, the coating solution for forming the charge generation layer obtained as described above was applied on the undercoat layer with a wire bar so that the film thickness after drying was about 0.3 μm, and dried at room temperature. A charge generation layer was provided.

Subsequently, the charge transport layer forming coating solution obtained as described above was applied onto the charge generation layer with an applicator so that the film thickness after drying was about 21 μm, and dried at 125 ° C. for 20 minutes. Thus, a photoreceptor A1 was produced.

[Example 2]
Photoreceptor A2 was prepared in the same manner as in Example 1 except that 50 parts of CT-2 represented by the following formula was used instead of CT-1 as the charge transport material.

[Example 3]
A photoconductor A3 was produced in the same manner as in Example 1 except that PC2 was used instead of PC1 as the polycarbonate resin.
[Example 4]
Photoreceptor A4 was prepared in the same manner as in Example 1 except that 50 parts of CT-3 represented by the following formula was used in place of CT-1 as the charge transport material.

[Example 5]
A photoconductor A5 was prepared in the same manner as in Example 1 except that 50 parts of CT-4 represented by the following formula was used instead of CT-1 as a charge transport material.

[Comparative Example 1]
A photoconductor B1 was prepared in the same manner as in Example 1 except that the polycarbonate resin was changed from PC1 manufactured by the melting method to the PC3 manufactured by the interface method.
[Comparative Example 2]
A photoconductor B2 was prepared in the same manner as in Example 2 except that the polycarbonate resin was changed from PC1 manufactured by the melting method to PC3 manufactured by the interface method.

[Comparative Example 3]
A photoconductor B3 was prepared in the same manner as in Example 1 except that 50 parts of CT-5 shown below was used as the charge transport material.

[Comparative Example 4]
Photoreceptor B4 was prepared in the same manner as in Example 1 except that 56 parts of CT-6 and 14 parts of CT-7 shown below were used in combination as the charge transport material.

[Comparative Example 5]
A photoconductor B5 was prepared in the same manner as in Example 1 except that 50 parts of CT-8 shown below was used as the charge transport material.

[Comparative Example 6]
A photoconductor B6 was prepared in the same manner as in Example 1 except that the polycarbonate resin was changed from PC1 manufactured by the melting method to the PC4 manufactured by the interface method.
[Comparative Example 7]
Photoreceptor B7 was produced in the same manner as in Example 1 except that PC3 was used as the polycarbonate resin and CT-5 was used as the charge transport material.

<Electrical characteristics test>
The surface potential VL is measured using an electrophotographic characteristic evaluation apparatus manufactured according to the Electrophotographic Society measurement standard (basic and applied electrophotographic technology, edited by Electrophotographic Society, Corona, pages 404 to 405). The sheets A1 to A5 and B1 to B7 are attached to an aluminum drum having a diameter of 80 mm to form a cylinder, and the aluminum drum and the aluminum substrate of the photosensitive sheet are connected to each other. Then, the temperature is 25 ° C. and the relative humidity is 50. %, The drum is rotated at a constant rotation speed of 60 rpm, the charging (scorotron charger) conditions are fixed so that the initial surface potential of the photoreceptor is about −700 V, and the light of the halogen lamp is 780 nm with an interference filter. a material obtained by monochromatic light, the surface potential VL (unit: -V) at the time of exposure of the light intensity as 0.76μJ / cm ² using a ND filter in the measurement It is. The VL of a photoconductor prepared using polycarbonate resins PC1 to PC4 immediately after manufacture and the VL of a photoconductor prepared in the same manner using a resin that has passed 8 months after manufacture are measured, and the difference (ΔVL) is shown in Table 2. Indicated. During this time, the polycarbonate was stored in a room at 20 ° C to 30 ° C.

  The smaller the value of the VL change (ΔVL), the better. In general, the polycarbonate resins (PC1, 2) satisfying the content of the structural unit derived from the compound represented by the formula (2) or the formula (3) defined in the present invention are the polycarbonate resins (PC3, 4) which are not satisfied. In comparison, the ΔVL value tends to increase as the number of days after production elapses. Among the polycarbonate resins of the present invention, the charge transport material (CT-1 to 4) represented by formula (A) or formula (B) It can be seen that the photosensitive member using is suppressed in an increase in ΔVL compared to the charge transport material CT-6, 7, or 8 having other structures.

<Plus charge application test>
Next, the characteristics of the photoreceptors A1, A2, A3, B1, B2, B6, and B7 with respect to positive charges applied to the photoreceptor during toner transfer were examined. After measuring the surface potential VL in the same manner as in the electrical property test 1 described above, the charging (scorotron charger) conditions were fixed so that the initial surface potential of the photosensitive member was about −700 V while rotating the photosensitive member at 60 rpm. Then, a positive voltage of 6.5 kv is applied to another corotron charger and rotated 4000 times. Thereafter, the positive voltage was turned off, and the surface potential VL was measured as in the initial stage. Table 3 shows the VL difference before and after applying the positive charge. The photoreceptor using the polycarbonate resin of the present invention, PC1 and PC2, compared with the photoreceptor using the polycarbonate resin of the comparative example, PC3 or PC4, even if the same charge transport material is used, the increase in VL is achieved. This is preferable in terms of image memory by transfer.

<Surface hardness measurement>
Subsequently, for the photoreceptors A1, A3, A5, B3, B4, and B7, universal hardness measurement of the photoreceptor surface was performed. Using a micro hardness tester (Fischer: FISCHERSCOPE HM2000LT), a Vickers square pyramid diamond indenter having a facing angle of 136 ° is used in an environment of a temperature of 25 ° C. and a relative humidity of 50%. The measurement conditions are as follows.

[Measurement condition]
Maximum pushing load 5mN
Load time 10s
Unloading time 10s
In the present invention, the universal hardness is a value when the indentation load is indented to 5 mN, and is a value defined by the following formula from the indentation depth.

Universal hardness (N / mm ² ) = Test load (N) / Surface area of Vickers indenter under test load (mm ² )
Table 4 shows the measurement data. The photoconductor B7 using the charge transport material CT-5 has lower hardness than the photoconductor using other charge transport materials, and the image defect is affected by the stress of paper, toner, charging roller or the like in the machine. It is likely to occur.

[Example 6]
On the 3003 series aluminum alloy tube having a diameter of 30 mm, a length of 246 mm, and a wall thickness of 0.75 mm, the coating film for forming the undercoat layer obtained as described above has a film thickness after drying of about 1.5 μm. In this way, it was dip coated and dried at room temperature to provide an undercoat layer.
Subsequently, the charge generation layer forming coating solution obtained as described above is dip-coated on the undercoat layer so that the film thickness after drying is about 0.3 μm, and dried at room temperature. A charge generation layer was provided.
Subsequently, a photosensitive drum A6 was produced in which the following charge transport layer forming coating solution B was dip-coated on the charge generation layer so that the film thickness after drying was about 15 μm.

[Manufacture of coating solution for charge transport layer formation]
The charge transport layer forming coating solution was prepared as follows. 50 parts of the above charge transport material CT-1, 100 parts of the polycarbonate resin PC1, 4 parts by weight of the above formula AD-2 as an antioxidant, and 0.05 parts of silicone oil as a leveling agent in tetrahydrofuran (hereinafter referred to as THF as appropriate). Abbreviation) and toluene (hereinafter abbreviated as TL as appropriate) (THF 80 wt%, TL)
20 wt%) was mixed with 600 parts to prepare a charge transport layer forming coating solution.

<Image test>
The produced photosensitive drum A6 was mounted on a black drum cartridge for a color printer MICROLINE Pro 9800PS-E manufactured by Oki Data. Next, a developing toner (volume average particle size 7.05 μm, Dv / Dn = 1.14, average circularity 0. 10 μm) manufactured according to the manufacturing method (emulsion polymerization aggregation method) of developing toner A disclosed in Japanese Patent Application Laid-Open No. 2007-213050. 963) was mounted on a black toner cartridge. These drum cartridges and toner cartridges were mounted on the printer.

Specifications of MICROLINE Pro 9800PS-E 4 tandem color 36ppm, monochrome 40ppm
1200 dpi
Contact roller charging (DC voltage applied)
LED exposure With static elimination light When 10,000 sheets of images were formed in an environment of a temperature of 35 ° C. and a humidity of 80%, a good image was obtained with good cleaning properties and no defects due to photoreceptor contamination.

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
DESCRIPTION OF SYMBOLS 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (9)

A polycarbonate resin having a repeating unit derived from the compound represented by the following formula (1) in the photosensitive layer, wherein the content of the structural unit derived from the compound represented by the following formula (2) is An electrophotographic photoreceptor comprising a polycarbonate resin having a concentration of 20 ppm or more and 2000 ppm or less and a charge transport material represented by the following formula (A) or (B):

(In Formula (A), Ar ¹ and Ar ² each independently represent an aryl group which may have a substituent, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent Each independently represents a hydrogen atom, an alkyl group or an alkoxy group, and n represents an integer of 1 to 5.)

(In formula (B), R ⁵ and R ⁶ each independently represents an alkyl group.) A polycarbonate resin having a repeating unit derived from the compound represented by the following formula (1) in the photosensitive layer, wherein the content of the structural unit derived from the compound represented by the following formula (3) is An electrophotographic photoreceptor comprising a polycarbonate resin of 200 ppm to 7000 ppm and at least one charge transporting material represented by the following formula (A) or (B).

(In Formula (A), Ar ¹ and Ar ² each independently represent an aryl group which may have a substituent, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent Each independently represents a hydrogen atom, an alkyl group or an alkoxy group, and n represents an integer of 1 to 5.)

(In formula (B), R ⁵ and R ⁶ each independently represents an alkyl group.) In the polycarbonate resin having a repeating unit derived from the compound represented by the formula (1), the content of the structural unit derived from the compound represented by the following formula (4) is 100 ppm or more and 2000 ppm or less in the resin. The electrophotographic photosensitive member according to claim 1, wherein:

  The polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) is produced by a transesterification reaction between a carbonic acid diester and an aromatic dihydroxy compound. The electrophotographic photosensitive member according to item 1.   The polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) is produced by a transesterification reaction using cesium carbonate, cesium bicarbonate, or cesium hydroxide. The electrophotographic photosensitive member according to any one of the above. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains at least one compound represented by the following formula (C) or a compound represented by the following formula (D).

(In formula (C), R ^{7 to} R ⁹ each independently represents an alkyl group.)

(In formula (D), R ^{10 to} R ¹² each independently represents an alkyl group, and m represents an integer of 1 to 3.) The polycarbonate resin having a repeating unit derived from the compound represented by the formula (1) includes a structural unit represented by the following formula (5). The electrophotographic photoreceptor described in 1.

  The electrophotographic photosensitive member according to claim 1, a charging device for charging the electrophotographic photosensitive member, and exposure for forming an electrostatic latent image by exposing the charged electrophotographic photosensitive member. An electrophotographic photosensitive member cartridge comprising: an apparatus; and at least one selected from the group consisting of a developing device that develops an electrostatic latent image formed on the electrophotographic photosensitive member.   The electrophotographic photosensitive member according to claim 1, a charging device that charges the electrophotographic photosensitive member, and an exposure device that forms an electrostatic latent image by exposing the charged electrophotographic photosensitive member. An image forming apparatus comprising: a developing device that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

Images