CN110684181A - Polyarylate resin and electrophotographic photoreceptor - Google Patents

Abstract

The invention provides a polyarylate resin and an electrophotographic photoreceptor. The polyarylate resin is represented by the following general formula (1). In the general formula (1), R¹、R²、R³And R⁴Each independently represents a hydrogen atom or a methyl group. r, s, t and u all represent positive integers. r + s + t + u is 100. r + t is s + u. r/(r + t) is 0.10 to 0.70. s/(s + u) is 0.10 to 0.70. X represents a divalent group represented by formula (2A), formula (2B), formula (2C) or formula (2D). Y represents a divalent group represented by formula (4A), formula (4B), formula (4C), formula (4D), or formula (4E). X and Y are different from each other. [ CHEM 1 ]

(ii) a [ CHEM 2 ]

(ii) a [ CHEM 3 ]

Description

Polyarylate resin and electrophotographic photoreceptor

The present application is a divisional application of an application having an application date of 2017, 9/12/No. 201710820342.1 and an invention name of "polyarylate resin and electrophotographic photoreceptor".

Technical Field

The present invention relates to a polyarylate resin and an electrophotographic photoreceptor.

Background

Electrophotographic photoreceptors are used as image carriers in electrophotographic image forming apparatuses (e.g., printing apparatuses or multifunction machines). The electrophotographic photoreceptor includes a photosensitive layer. The electrophotographic photoreceptor is, for example, a single-layer type electrophotographic photoreceptor or a laminated type electrophotographic photoreceptor. The single-layer type electrophotographic photoreceptor comprises: a photosensitive layer having a charge generation function and a charge transport function. In the laminated electrophotographic photosensitive body, the photosensitive layer comprises: a charge generation layer having a charge generation function and a charge transport layer having a charge transport function.

Patent document 1 describes a polyarylate Resin having a repeating unit represented by the chemical formula (Resin-a). Also disclosed is an electrophotographic photoreceptor containing the polyarylate resin.

[ CHEM 1 ]

[ patent document ]

Patent document 1: japanese laid-open patent publication No. 5-297601

Disclosure of Invention

However, entanglement of molecular chains in the polyarylate resin is reduced, and the stacking property of the polyarylate resin is reduced, so that the film forming resistance of the photoreceptor cannot be sufficiently improved.

In view of the above-described problems, the present invention provides a polyarylate resin having excellent film formation resistance for an electrophotographic photoreceptor. Another object of the present invention is to provide an electrophotographic photoreceptor having a photosensitive layer having excellent film formation resistance.

The polyarylate resin of the present invention is represented by the following general formula (1).

[ CHEM 2 ]

In the general formula (1), R¹、R²、R³And R⁴Each independently represents a hydrogen atom or a methyl group. r, s, t and u all represent positive integers. r + s + t + u is 100. r + t is s + u. r/(r + t) is 0.10 to 0.70. s/(s + u) is 0.10 to 0.70. X represents a divalent group represented by formula (2A), formula (2B), formula (2C) or formula (2D). Y represents a divalent group represented by chemical formula (4A), chemical formula (4B), chemical formula (4C), chemical formula (4D), or chemical formula (4E). X and Y are different from each other.

[ CHEM 3 ]

[ CHEM 4 ]

The electrophotographic photoreceptor of the present invention includes a conductive substrate and a photosensitive layer. The photosensitive layer contains: a charge generating agent, a hole transporting agent and a binder resin. The binder resin comprises the polyarylate resin described above.

(effect of the invention)

The polyarylate resin of the present invention can impart excellent film formation resistance to an electrophotographic photoreceptor. The electrophotographic photoreceptor of the present invention is excellent in filming resistance.

Drawings

Fig. 1(a), 1(b), and 1(c) are schematic cross-sectional views each showing an example of the structure of an electrophotographic photoreceptor according to a second embodiment of the present invention.

FIG. 2 shows a polyarylate Resin represented by the formula (Resin-1)¹H-NMR spectrum.

Detailed Description

The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the intended scope of the present invention. Note that, although the description of the overlapping portions may be omitted as appropriate, the gist of the present invention is not limited thereto. In the present specification, the compound and its derivatives may be collectively referred to by adding "class" to the compound name. In the case where a "class" is added after the name of a compound to indicate the name of a polymer, it indicates that the repeating unit of the polymer is derived from the compound or its derivative.

Hereinafter, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a cycloalkane having 5 to 7 carbon atoms each represent the following meanings.

The alkyl group having 1 to 8 carbon atoms is linear or branched and unsubstituted. Examples of the alkyl group having 1 to 8 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, or octyl.

The alkyl group having 1 to 6 carbon atoms is linear or branched and unsubstituted. Examples of the alkyl group having 1 to 6 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl or hexyl.

The alkyl group having 1 to 4 carbon atoms is linear or branched and unsubstituted. Examples of the alkyl group having 1 to 4 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl or tert-butyl.

The alkoxy group having 1 to 8 carbon atoms is linear or branched and is unsubstituted. Examples of the alkoxy group having 1 to 8 carbon atoms include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy, neopentoxy, hexoxy, heptoxy or octoxy.

The alkoxy group having 1 to 4 carbon atoms is linear or branched and is unsubstituted. Examples of the alkoxy group having 1 to 4 carbon atoms include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy or tert-butoxy.

The cycloalkane having 5 to 7 carbon atoms is unsubstituted. Examples of the cycloalkane having 5 to 7 carbon atoms include cyclopentane, cyclohexane, and cycloheptane.

< first embodiment: polyarylate resin >

The polyarylate resin according to the first embodiment of the present invention is represented by the general formula (1). Hereinafter, such a polyarylate resin may be referred to as a polyarylate resin (1).

[ CHEM 5 ]

In the general formula (1), R¹、R²、R³And R⁴Each independently represents a hydrogen atom or a methyl group. r, s, t and u all represent positive integers. r + s + t + u is 100. r + t is s + u. r/(r + t) is 0.10 to 0.70. s/(s + u) is 0.10 to 0.70. X represents a divalent group represented by formula (2A), formula (2B), formula (2C) or formula (2D). Y represents a divalent group represented by chemical formula (4A), chemical formula (4B), chemical formula (4C), chemical formula (4D), or chemical formula (4E). X and Y are different from each other.

[ CHEM 6 ]

[ CHEM 7 ]

In the general formula (1), R is preferably represented by formula (1) in order to further improve the filming resistance of the photoreceptor¹、R²、 R³And R⁴Represents a methyl group. From the viewpoint of further improving the filming resistance of the photoreceptor, it is preferable that X represents a divalent group represented by the general formula (2A) or the general formula (2B), or Y represents a divalent group represented by the general formula (4A) or the general formula (4B).

From the viewpoint of particularly improving the filming resistance of the photoreceptor, X preferably represents a divalent group represented by the general formula (2A) or the general formula (2B). Y preferably represents a divalent group represented by the general formula (4A), the general formula (4B) or the general formula (4E).

R and s may be different from each other, and r and u may be different from each other. T and s may be different from each other, and t and u may be different from each other.

The polyarylate resin (1) has: the repeating unit represented by chemical formula (1-5) (hereinafter, may be referred to as repeating unit (1-5)), the repeating unit represented by general formula (1-6) (hereinafter, may be referred to as repeating unit (1-6)), the repeating unit represented by general formula (1-7) (hereinafter, may be referred to as repeating unit (1-7)), and the repeating unit represented by general formula (1-8) (hereinafter, may be referred to as repeating unit (1-8)).

[ CHEM 8 ]

R in the general formula (1-5)¹And R²X in the general formula (1-6) and R in the general formula (1-7)³And R⁴And Y in the general formulae (1-8) and R in the general formula (1) respectively¹、R²、X、R³、R⁴And Y has the same meaning.

The polyarylate resin (1) may have a repeating unit other than the repeating units (1-5) to (1-8). The ratio (mole fraction) of the total amount of the repeating units (1-5) to (1-8) to the total amount of the repeating units in the polyarylate resin (1) is preferably 0.80 or more, more preferably 0.90 or more, and further preferably 1.00.

The arrangement of the repeating units (1-5) to (1-8) in the polyarylate resin (1) is not particularly limited as long as the repeating unit derived from the aromatic diol and the repeating unit derived from the aromatic dicarboxylic acid are adjacent to each other. For example, the repeating units (1-5) are adjacent to and bonded to the repeating units (1-6) or the repeating units (1-8). Similarly, the repeating units (1-7) are adjacent to and bonded to the repeating units (1-6) or the repeating units (1-8). The polyarylate resin (1) may have a repeating unit other than the repeating units (1-5) to (1-8).

In the general formula (1), r, s, t and u all represent positive integers. r + s + t + -u-100. r + t is s + u. r/(r + t) is 0.10 to 0.70, preferably 0.30 to 0.70. s/(s + u) is 0.10 to 0.70, preferably 0.30 to 0.70. r/(r + t) represents the ratio (molar fraction) of the amount of the substance having the repeating unit (1-5) to the total of the amounts of the substance having the repeating units (1-5) and the substances having the repeating units (1-7) in the polyarylate resin (1). When r/(r + t) is 0.10 or more and 0.70 or less, the photoreceptor is excellent in film formation resistance. s/(s + u) represents the ratio (molar fraction) of the amount of the substance having the repeating unit (1-6) to the total of the amounts of the substance having the repeating units (1-6) and the substance having the repeating units (1-8) in the polyarylate resin (1). When s/(s + u) is 0.10 to 0.70, the photoreceptor is excellent in film formation resistance.

The polyarylate Resin (1) is, for example, polyarylate resins represented by the chemical formulas (Resin-1) to (Resin-7) (hereinafter, sometimes referred to as polyarylate resins (Resin-1) to (Resin-7)).

[ CHEM 9 ]

[ CHEM 10 ]

[ CHEM 11 ]

[ CHEM 12 ]

[ CHEM 13 ]

[ CHEM 14 ]

[ CHEM 15 ]

The viscosity average molecular weight of the binder resin is preferably 10,000 or more, more preferably 14,000 or more, and further preferably 20,000 or more. The viscosity average molecular weight of the binder resin is preferably 100,000 or less, more preferably 80,000 or less, and further preferably 70,000 or less. When the viscosity average molecular weight of the binder resin is 20,000 or more, the abrasion resistance of the binder resin can be improved, and the charge transport layer is less likely to be abraded. On the other hand, when the viscosity average molecular weight of the binder resin is 70,000 or less, the binder resin is easily dissolved in a solvent when forming the photosensitive layer, and the photosensitive layer is often easily formed.

(method for producing Binder resin)

The method for producing the binder resin is not particularly limited as long as the polyarylate resin (1) can be produced. These manufacturing methods include, for example: a method for polycondensation of an aromatic diol and an aromatic dicarboxylic acid constituting a repeating unit of a polyarylate resin. The method for synthesizing the polyarylate resin (1) is not particularly limited, and a known synthesis method (more specifically, solution polymerization, melt polymerization, interfacial polymerization, or the like) can be used. An example of the method for producing the polyarylate resin (1) will be described below.

The polyarylate resin (1) can be produced, for example, by a reaction represented by the reaction formula (R-1) (hereinafter, may be referred to as reaction (R-1)) or a similar method thereto. The method for producing a polyarylate resin comprises, for example, the reaction (R-1).

[ CHEM 16 ]

In the reaction (R-1), R in the general formula (1-11)¹And R²R in the general formula (1-12)³And R⁴X in the general formula (1-9) and Y in the general formula (1-10) are respectively R in the general formula (1)¹、 R²、R³、R⁴X and Y have the same meanings.

In the reaction (R-1), the aromatic dicarboxylic acids represented by the general formulae (1 to 9) and the aromatic dicarboxylic acids represented by the general formulae (1 to 10) (hereinafter, sometimes referred to as the aromatic dicarboxylic acids (1 to 9) and (1 to 10), respectively) are reacted with the aromatic diols represented by the general formulae (1 to 11) and the aromatic diols represented by the general formulae (1 to 12) (hereinafter, sometimes referred to as the aromatic diols (1 to 11) and (1 to 12), respectively), to obtain the polyarylate resin (1).

The amount of the total substance of the aromatic diols (1-11) and (1-12) is preferably 0.9 mol to 1.0 mol, relative to 1 mol of the total substance of the aromatic carboxylic acids (1-9) and (1-10). This is because the polyarylate resin (1) can be easily purified within the above range, and the yield of the polyarylate resin (1) can be improved.

The reaction (R-1) may be carried out in the presence of a base and a catalyst. Examples of the catalyst include: tertiary ammonium (more specifically, trialkylamine and the like) or quaternary ammonium salt (more specifically, benzyltrimethylammonium bromide and the like). Examples of the base include: hydroxides of alkali metals (more specifically, sodium hydroxide, potassium hydroxide, or the like), hydroxides of alkaline earth metals (more specifically, calcium hydroxide, or the like). The reaction (R-1) may be carried out in a solvent under an inert gas atmosphere. Examples of the solvent include water and chloroform. An inert gas such as argon. The reaction time of the reaction (R-1) is preferably 2 hours or more and 5 hours or less. The reaction temperature is preferably 5 ℃ to 25 ℃.

Examples of the aromatic dicarboxylic acid include: an aromatic dicarboxylic acid having 2 carboxyl groups bonded to an aromatic ring (more specifically, naphthalenedicarboxylic acid, 4 '-dicarboxydiphenyl ether, 4' -biphenyldicarboxylic acid, or the like). The aromatic dicarboxylic acid may contain dicarboxylic acids other than the aromatic dicarboxylic acids (1-9) and (1-10). In addition, in the synthesis of the polyarylate resin, an aromatic dicarboxylic acid derivative (more specifically, an alkyl halide or an aromatic dicarboxylic anhydride) may be used instead of the aromatic dicarboxylic acid.

When the polyarylate resin is synthesized, a derivative such as diacetate can be used as the aromatic diol. The aromatic diol may contain other diols (for example, bisphenol A, bisphenol S, bisphenol E, or bisphenol F) other than the aromatic diols (1 to 11) and (1 to 12).

The polyarylate resin (1) may contain other steps as necessary. Such a process is, for example, a purification process. The purification method is, for example, a well-known method (more specifically, filtration, chromatography, crystallization or the like).

< second embodiment: electrophotographic photoreceptor

An electrophotographic photoreceptor (hereinafter, referred to as a photoreceptor) according to a second embodiment of the present invention includes a conductive substrate and a photosensitive layer. Examples of the photoreceptor include: a laminated electrophotographic photoreceptor (hereinafter, sometimes referred to as a laminated photoreceptor) or a single-layer electrophotographic photoreceptor (hereinafter, sometimes referred to as a single-layer photoreceptor).

The laminated photoreceptor comprises: a charge generation layer and a charge transport layer. The structure of the laminated photoreceptor 1 according to the second embodiment will be described below with reference to fig. 1. Fig. 1 is a schematic cross-sectional view showing the structure of the laminated photoreceptor 1. As shown in fig. 1(a), the laminated photoreceptor 1 includes, for example, a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 includes: a charge generation layer 3a and a charge transport layer 3 b. As shown in fig. 1(a), the laminated photoreceptor 1 may include a charge generation layer 3a on the conductive substrate 2, and a charge transport layer 3b on the charge generation layer 3 a. As shown in fig. 1(b), the laminated photoreceptor 1 may further include a charge transport layer 3b on the conductive substrate 2 and a charge generation layer 3a on the charge transport layer 3 b. As shown in fig. 1(a), the charge transport layer 3b may be disposed as the outermost layer of the laminated photoreceptor 1. The charge transport layer 3b may be a single layer (single layer).

As shown in fig. 1(a), the photosensitive layer 3 may be disposed directly on the conductive substrate 2. As shown in fig. 1(c), the laminated photoreceptor 1 includes, for example: a conductive substrate 2, an intermediate layer 4 (undercoat layer), and a photosensitive layer 3. As shown in fig. 1(c), the photosensitive layer 3 may be indirectly disposed on the conductive substrate 2. As shown in fig. 1(c), the intermediate layer 4 may be provided between the conductive substrate 2 and the charge generation layer 3 a. The intermediate layer 4 may be provided between the charge generation layer 3a and the charge transport layer 3b, for example. The charge generation layer 3a may be a single layer or a plurality of layers.

The single-layer photoreceptor has a single photosensitive layer. The single layer type photoreceptor also includes, for example, a conductive substrate and a photosensitive layer, as in the case of the laminated type photoreceptor. The single-layer photoreceptor may have an intermediate layer. The photosensitive layer may be configured as the outermost layer of the single layer type photoreceptor.

The photoreceptor according to the second embodiment is excellent in filming resistance. The reason is presumed as follows. The photoreceptor according to the second embodiment contains a polyarylate resin (1) as a binder resin. The polyarylate resin (1) has a repeating unit containing a fluorene ring. The molar fraction r/(r + t) of the repeating units derived from the aromatic diol is 0.10 to 0.70. The molar fraction s/(s + u) of the repeating units derived from the aromatic dicarboxylic acid is 0.10 to 0.70. The polyarylate resin (1) having such a structure is not only less likely to cause entanglement between the binder resin and the binder resin, but also less likely to cause stacking between the binder resins. Further, the polyarylate resin (1) having such a structure has high solubility in a solvent, and thus a coating liquid for forming a photosensitive layer can be easily prepared. As a result, a photosensitive layer having high layer density and high hardness can be easily obtained. Therefore, the photoreceptor according to the second embodiment is excellent in filming resistance.

Hereinafter, elements (the conductive substrate, the photosensitive layer, and the intermediate layer) of the photoreceptor according to the second embodiment will be described. A method for manufacturing the photoreceptor will also be described.

[1. conductive substrate ]

The conductive substrate is not particularly limited as long as it can be used as a conductive substrate of a photoreceptor. At least the surface portion of the conductive substrate may be formed of a material having conductivity (hereinafter, may be referred to as a conductive material). Examples of the conductive substrate include: a conductive substrate made of a conductive material or a conductive substrate coated with a conductive material. Examples of the conductive material include: aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, or indium. These conductive materials may be used alone or in combination of two or more. The combination of two or more kinds is, for example, an alloy (more specifically, an aluminum alloy, stainless steel, brass, or the like).

These conductive materials are preferably aluminum or aluminum alloy in view of good charge transfer from the photosensitive layer to the conductive substrate.

The shape of the conductive substrate can be appropriately selected in accordance with the structure of the image forming apparatus to be used. The conductive substrate may have a sheet-like or drum-like shape, for example. The thickness of the conductive substrate may be appropriately selected according to the shape of the conductive substrate.

[2. photosensitive layer ]

The photosensitive layer contains: a charge generating agent, a hole transporting agent, and a polyarylate resin (1) as a binder resin. The photosensitive layer may further contain an additive. In the laminated photoreceptor, the photosensitive layer includes a charge generation layer and a charge transport layer. The charge generation layer contains a charge generating agent. The charge transport layer contains a hole transport agent and a binder resin. The thickness of the charge generation layer is not particularly limited as long as the charge generation layer can sufficiently function as a charge generation layer. Specifically, the thickness of the charge generation layer is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less. The thickness of the charge transport layer is not particularly limited as long as the charge transport layer can sufficiently function as a charge transport layer. Specifically, the thickness of the charge transport layer is preferably 2 μm to 100 μm, and more preferably 5 μm to 50 μm.

In the single layer type photoreceptor, the photosensitive layer is a single layer type photosensitive layer. The monolayer type photosensitive layer contains: a charge generating agent, a hole transporting agent and a binder resin. The thickness of the photosensitive layer is not particularly limited as long as the photosensitive layer can sufficiently function as a photosensitive layer. Specifically, the thickness of the photosensitive layer may be 5 μm to 100 μm, and preferably 10 μm to 50 μm.

[2-1. common structural elements ]

The charge generating agent, the hole transporting agent, and the binder resin will be described below. And additives are also described.

[2-1-1. Charge-generating agent ]

The charge generating agent is not particularly limited as long as it is a charge generating agent for a photoreceptor. Charge generators are for example: phthalocyanine pigments, perylene pigments, disazo pigments, diketopyrrolopyrrole (dithioketo-pyrolole) pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaric acid pigments, trisazo pigments, indigo pigments, azulene pigments, cyanine pigments; powders of inorganic photoconductive materials such as selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, amorphous silicon; pyranate, an anthanthroquinone pigment, a triphenylmethane pigment, a threne pigment, a toluidine pigment, a pyrazoline pigment, or a quinacridone pigment. Examples of the phthalocyanine pigment include phthalocyanine and phthalocyanine derivatives. Examples of the phthalocyanine include metal-free phthalocyanine pigments (more specifically, X-type metal-free phthalocyanine (X-H)₂Pc), etc.). Examples of the phthalocyanine derivative include: a metal phthalocyanine pigment (more specifically, oxytitanium phthalocyanine or V-type hydroxygallium phthalocyanine, etc.). The crystal shape of the phthalocyanine pigment is not particularly limited, and phthalocyanine pigments having various crystal shapes can be used. The crystal shape of the phthalocyanine pigment is, for example: alpha, beta or Y form. The charge generating agent may be used alone or in combination of two or more. When the photosensitive layer contains a polyarylate resin, the charge generating agent is preferably a phthalocyanine pigment, more preferably a metal phthalocyanine pigment, and still more preferably Y-type oxytitanium phthalocyanine.

The Y-type oxytitanium phthalocyanine may have a main peak at a bragg angle 2 θ ± 0.2 ° to 27.2 ° in a Cu — K α characteristic X-ray diffraction spectrum. The main peak in the CuK α characteristic X-ray diffraction spectrum means a peak having a first or second large intensity in a range where the bragg angle (2 θ ± 0.2 °) is 3 ° or more and 40 ° or less.

(method for measuring CuK alpha characteristic X-ray diffraction Spectrum)

A method for measuring CuK α characteristic X-ray diffraction spectrum will be explained. A sample (oxytitanium phthalocyanine) was filled in a sample holder of an X-ray diffraction apparatus ("RINT (registered trademark) 1100" manufactured by Rigaku Corporation) under an X-ray tube Cu, a tube voltage of 40kV, a tube current of 30mA, and a wavelength of Cu-Ka characteristic X-rays

Under the conditions of (1) to measure an X-ray diffraction spectrum. The measurement range (2 θ) is 3 ° to 40 ° (initial angle 3 °; stop angle 40 °), and the scanning speed is, for example, 10 °/min. The main peak is determined from the obtained X-ray diffraction spectrum, and the bragg angle of the main peak is read.

The charge generating agent having an absorption wavelength in a desired region may be used alone, or two or more kinds of charge generating agents may be used in combination. In addition, for example, in a digital optical image forming apparatus, a photoreceptor having sensitivity in a wavelength region of 700nm or more is preferably used. Examples of digital optical image forming apparatuses include laser printers and facsimile machines that use a light source such as a semiconductor laser. Therefore, for example, phthalocyanine pigments are preferable, and Y-type oxytitanium phthalocyanine (Y-TiOPc) is more preferable.

In the photoreceptor used in the image forming apparatus using the short-wavelength laser light source, an anthraquinone-based pigment or a perylene-based pigment is preferably used as the charge generating agent. The short-wavelength laser light source has a wavelength of, for example, about 350nm to 550 nm.

The charge generating agent is, for example, phthalocyanine pigments represented by chemical formulas (CGM-1) to (CGM-4) (hereinafter, sometimes referred to as charge generating agents (CGM-1) to (CGM-4)).

[ CHEM 17 ]

[ CHEM 18 ]

[ CHEM 19 ]

[ CHEM 20 ]

The content of the charge generating agent is preferably 5 parts by mass or more and 1000 parts by mass or less, and more preferably 30 parts by mass or more and 500 parts by mass or less, with respect to 100 parts by mass of the charge generating layer binder resin (hereinafter, may be referred to as a matrix resin).

[2-1-2. hole-transporting agent ]

The hole-transporting agent may be, for example, a nitrogen-containing cyclic compound or a condensed polycyclic compound. Examples of the nitrogen-containing cyclic compound and the condensed polycyclic compound include: diamine derivatives (more specifically, N '-tetraphenylphenylenediamine derivatives, N' -tetraphenylnaphthalenediamine derivatives, or N, N '-tetraphenylphenylenediamine (N, N' -tetraphenylphenylenediamine) derivatives, etc.); oxadiazole compounds (more specifically, 2, 5-bis (4-methylaminophenyl) -1, 3, 4-oxadiazole and the like); a styrene compound (more specifically, 9- (4-diethylaminostyryl) anthracene, etc.); carbazole-based compounds (more specifically, polyvinylcarbazoles and the like); an organic polysilane compound; pyrazolines (more specifically, 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline, etc.); a hydrazone compound; indole compounds; an oxazole compound; isoxazoles compounds; thiazole compounds; a thiadiazole compound; imidazole compounds; a pyrazole compound; a triazole compound.

Among these hole transport agents, from the viewpoint of improving the filming resistance of the photoreceptor, compounds represented by the general formula (2), the general formula (3), or the general formula (4) are preferable, compounds represented by the general formula (3) or the general formula (4) are more preferable, and compounds represented by the general formula (4) are even more preferable.

[ CHEM 21 ]

In the general formula (2), Q₁Represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. The phenyl group may have an alkyl group having 1 to 8 carbon atoms. Q₂Represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. Q₃、Q₄、Q₅、Q₆And Q₇Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. Q₃、Q₄、Q₅、Q₆And Q₇Two adjacent of them may be bonded to each other to form a ring. a represents an integer of 0 to 5 inclusive. a represents an integer of 2 to 5, and Q's bonded to the same phenyl group₂Either the same or different.

[ CHEM 22 ]

In the general formula (3), Q₈、Q₁₀、Q₁₁、Q₁₂、Q₁₃And Q₁₄Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. Q₉And Q₁₅Each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. b represents an integer of 0 to 5 inclusive. b represents an integer of 2 to 5, bonded to the sameA plurality of Q of phenyl groups₉May be the same or different. c represents an integer of 0 to 4. c represents an integer of 2 to 4, and Q's bonded to the same phenylene group₁₅May be the same or different. k represents 0 or 1.

[ CHEM 23 ]

In the general formula (4), R_a、R_bAnd R_cEach independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an alkoxy group having 1 to 8 carbon atoms. q represents an integer of 0 to 4. When q represents an integer of 2 to 4, R's bonded to the same phenylene group_cEither the same or different. m and n are each independently an integer of 0 to 5. When m represents an integer of 2 to 5, R's bonded to the same phenyl group_bMay be the same or different. When n represents an integer of 2 to 5, R's bonded to the same phenyl group_aEither the same or different.

In the general formula (2), Q₁The phenyl group is preferably a phenyl group having an alkyl group having 1 to 8 carbon atoms, and more preferably a phenyl group having a methyl group.

In the general formula (2), Q₂The alkyl group having 1 to 8 carbon atoms is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group. a preferably represents 0 or 1.

In the general formula (2), Q₃～Q₇The alkyl group having 1 to 8 carbon atoms is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an n-butyl group. In the general formula (2), Q₃～Q₇The alkoxy group having 1 to 8 carbon atoms is preferably an alkoxy group having 1 to 4 carbon atoms, and more preferably a methoxy group or an ethoxy group. In the general formula (2), Q₃～Q₇Each independently preferably represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or 1 carbon atomThe alkoxy group having 8 or less above is more preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.

In the general formula (2), Q₃～Q₇In (2), two adjacent rings may be bonded to each other to form a ring (more specifically, a benzene ring or a cycloalkane having 5 to 7 carbon atoms). For example, Q₃～Q₇Middle adjacent Q₆And Q₇Can be bonded to each other to form a benzene ring or a cycloalkane having 5 to 7 carbon atoms. Q₃～Q₇In the case where two adjacent thereof are bonded to each other to form a benzene ring, the benzene ring is bonded to Q₃～Q₇The bonded phenyl groups condense to form a bicyclic fused ring group (naphthyl). Q₃～Q₇Wherein when two adjacent cycloalkanes are bonded to each other to form a cycloalkane having 5 to 7 carbon atoms, the cycloalkane having 5 to 7 carbon atoms is bonded to Q₃～Q₇The bonded phenyl groups are condensed to form bicyclic fused ring groups. In this case, the condensation site of the phenyl group and the cycloalkane having 5 to 7 carbon atoms may contain a double bond. Preferably, Q₃～Q₇Wherein two adjacent ones of them are bonded to each other to form a cycloalkane having 5 to 7 carbon atoms inclusive, and more preferably form a cyclohexane.

In the general formula (2), preferably, Q₁Represents a phenyl group having an alkyl group of 1 to 8 carbon atoms or a hydrogen atom, Q₂Represents an alkyl group having 1 to 8 carbon atoms, Q₃～Q₇Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, Q₃～ Q₇May be bonded to each other to form a ring, and a represents 0 or 1.

In the general formula (3), Q₈And Q₁₀～Q₁₄The alkyl group having 1 to 8 carbon atoms is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. In the general formula (3), preferably, Q₈And Q₁₀～Q₁₄Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group. In the general formula (3), b and c preferably represent 0.

In the general formula (3), preferably, Q₈And Q₁₀、Q₁₁、Q₁₂、Q₁₃And Q₁₄Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and b and c represent 0.

In the general formula (4), R_aAnd R_bThe alkyl group having 1 to 8 carbon atoms is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. In the general formula (4), R is preferably_aAnd R_bEach independently represents an alkyl group having 1 to 8 carbon atoms. m and n are preferably independent of each other and each represents an integer of 0 to 2. q preferably represents 0.

In the general formula (4), R is preferably_aAnd R_bEach independently represents an alkyl group having 1 to 8 carbon atoms, m and n each independently represents an integer of 0 to 2, and q represents 0.

Examples of the hole-transporting agent represented by the general formula (2) include hole-transporting agents represented by the chemical formulas (HTM-1) to (HTM-4) (hereinafter, referred to as hole-transporting agents (HTM-1) to (HTM-4)). Examples of the hole-transporting agent represented by the general formula (3) include the hole-transporting agents represented by the chemical formulas (HTM-5) to (HTM-7) (hereinafter, may be referred to as hole-transporting agents (HTM-5) to (HTM-7)). Examples of the hole-transporting agent represented by the general formula (4) include the hole-transporting agents represented by the chemical formulas (HTM-8) to (HTM-9) (hereinafter, sometimes referred to as hole-transporting agents (HTM-8) to (HTM-9)).

[ CHEM 24 ]

[ CHEM 25 ]

[ CHEM 26 ]

[ CHEM 27 ]

[ CHEM 28 ]

[ CHEM 29 ]

[ CHEM 30 ]

[ CHEM 31 ]

[ CHEM 32 ]

In the laminated photoreceptor, the content of the hole transporting agent is preferably 10 parts by mass or more and 200 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less, with respect to 100 parts by mass of the binder resin.

[2-1-3. Binder resin ]

The binder resin is used for a charge transport layer of a laminated photoreceptor or a photosensitive layer of a single-layer photoreceptor. The binder resin comprises a polyarylate resin (1). The photoreceptor contains the polyarylate resin (1) and can improve the film formation resistance of the photoreceptor.

The binder resin used in the second embodiment may be the polyarylate resin (1) alone, or may contain a resin other than the polyarylate resin (1) within a range not to impair the effect of the present invention. Examples of the other resins include thermoplastic resins (more specifically, polyarylate resins other than polyarylate resin (1), polycarbonate resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, styrene-acrylic acid copolymers, polyethylene resins, ethylene-vinyl acetate copolymers, chlorinated polyethylene resins, polyvinyl chloride resins, polypropylene resins, ionomers, vinyl chloride-vinyl acetate copolymers, polyester resins, alkyd resins, polyamide resins, polyurethane resins, polysulfone resins, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyether resins, or polyester resins), thermosetting resins (more specifically, silicone resins, polycarbonate resins, styrene-acrylic acid copolymers, polyethylene resins, ethylene-vinyl acetate copolymers, chlorinated polyethylene resins, polyvinyl butyral resins, polyether resins, or polyester resins), thermosetting resins (more specifically, silicone resins, styrene-acrylic acid copolymers, styrene-acrylic acid, Epoxy resin, phenol resin, urea resin, melamine resin, or other crosslinkable thermosetting resin) or a photocurable resin (more specifically, epoxy-acrylic resin or urethane-acrylic copolymer). They may be used alone or in combination of 2 or more. The content of the polyarylate resin (1) is preferably 80 parts by mass or more, more preferably 90 parts by mass or more, and further preferably 100 parts by mass, relative to 100 parts by mass of the binder resin.

In the second embodiment, the ratio of the content of the binder resin to the total mass of all the structural elements (for example, the hole transporting agent or the binder resin) contained in the charge transport layer is preferably 40 mass% or more, and more preferably 80 mass% or more.

[2-1-4. additives ]

At least one of the charge generation layer, the charge transport layer, the photosensitive layer of the single-layer photoreceptor, and the intermediate layer may contain various additives within a range that does not adversely affect electrophotographic characteristics. Examples of additives are: deterioration inhibitors (more specifically, antioxidants, radical scavengers, delusterants, ultraviolet absorbers, or the like), softening agents, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, electron transport and electron acceptor compounds, donors, surfactants, or leveling agents. The antioxidant, and the electron transport agent and the electron acceptor compound among these additives will be described below.

Examples of the antioxidant include: a hindered phenol compound, a hindered amine compound, a thioether compound, or a phosphite compound. Among these antioxidants, hindered phenol compounds and hindered amine compounds are preferable.

Examples of the electron-transporting agent and the electron-acceptor compound include diphenoquinone derivatives (more specifically, 3, 3 ', 5, 5 ' -tetra-tert-butyl-4, 4 ' -diphenoquinone, etc.).

The amount of the antioxidant added to the charge transport layer is preferably 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount of the antioxidant is within such a range, the deterioration of the electrical characteristics due to the oxidation of the photoreceptor is easily suppressed.

[2-2. different constituent elements ]

In the laminated photoreceptor, the charge generation layer may contain a binder resin for the charge generation layer (hereinafter, sometimes referred to as a matrix resin). The base resin is not particularly limited as long as it can be applied to a photoreceptor. Examples of the matrix resin include: thermoplastic resins, thermosetting resins or photocurable resins. Examples of the thermoplastic resin include: styrene-based resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, styrene-acrylic copolymers, polyethylene resins, ethylene-vinyl acetate copolymers, chlorinated polyethylene resins, polyvinyl chloride resins, polypropylene resins, ionomers, vinyl chloride-vinyl acetate copolymers, alkyd resins, polyamide resins, polyurethane resins, polycarbonate resins, polyarylate resins, polysulfone resins, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyvinyl acetal resins, polyether resins, or polyester resins. Examples of the thermosetting resin include: silicone resins, epoxy resins, phenolic resins, urea-formaldehyde resins, melamine resins, or other cross-linking thermosetting resins. Examples of the photocurable resin include: epoxy acrylic resin or urethane-acrylic resin. These may be used alone or in combination of two or more. Among these matrix resins, polyvinyl acetal resins are preferred.

The matrix resin is the same resin as the binder resin, but in the same laminated photoreceptor, a resin different from the binder resin is usually selected. The reason for this is that, in the production of a multilayer photoreceptor, since a charge generation layer and a charge transport layer are usually formed in this order, a charge transport layer coating solution is applied to the charge generation layer. In the case of forming the charge transport layer, the charge generation layer is preferably a solvent that is not soluble in the coating liquid for charge transport layer. Therefore, in the same laminated photoreceptor, the matrix resin is usually selected from resins different from the binder resin.

[3. intermediate layer ]

The photoreceptor according to the second embodiment may have an intermediate layer (e.g., an undercoat layer). The intermediate layer contains, for example, inorganic particles and a resin (resin for intermediate layer). If the intermediate layer is present, the current flow generated when the photoreceptor is exposed can be made smooth while maintaining an insulating state to such an extent that the occurrence of current leakage can be suppressed, and the increase in resistance can be suppressed.

Examples of the inorganic particles include: particles of a metal (more specifically, aluminum, iron, copper, or the like), particles of a metal oxide (more specifically, titanium oxide, aluminum oxide, zirconium oxide, tin oxide, zinc oxide, or the like), or particles of a non-metal oxide (more specifically, silicon dioxide, or the like). These inorganic particles may be used alone or in combination of two or more. Further, the inorganic particles may be subjected to surface treatment.

The resin for the intermediate layer is not particularly limited as long as it can be used as a resin for forming the intermediate layer.

[4 ] method for producing photoreceptor

A method for manufacturing the photoreceptor will be described. The method of manufacturing the photoreceptor includes, for example, a photosensitive layer forming step.

[4-1. method for producing laminated photoreceptor ]

In the method for manufacturing a laminated photoreceptor, the photosensitive layer forming step includes a charge generation layer forming step and a charge transport layer forming step. In the charge generation layer forming step, first, a coating liquid for forming a charge generation layer (hereinafter, sometimes referred to as a coating liquid for a charge generation layer) is prepared. The coating liquid for the charge generation layer is applied to a conductive substrate to form a coating film. Next, the coating film is dried by an appropriate method, and at least a part of the solvent contained in the coating film is removed, thereby forming a charge generation layer. The coating liquid for the charge generating layer includes, for example: a charge generating agent, a matrix resin and a solvent. Such a charge generating layer coating liquid is prepared, for example, by dissolving or dispersing a charge generating agent and a matrix resin in a solvent. Various additives may be added to the charge generating layer coating solution as needed.

In the charge transport layer forming step, first, a coating liquid for forming a charge transport layer (hereinafter, sometimes referred to as a coating liquid for a charge transport layer) is prepared. The coating liquid for the charge transport layer is applied to the charge generation layer to form a coating film. Next, the coating film is dried by an appropriate method, and at least a part of the solvent contained in the coating film is removed to form a charge transport layer. The coating liquid for a charge transporting layer includes, for example: a hole transporting agent, a polyarylate resin (1) as a binder resin, and a solvent. The charge transport layer coating liquid can be prepared by, for example, dissolving or dispersing the hole transport agent and the polyarylate resin (1) in a solvent. Various additives may be added to the coating liquid for forming a charge transporting layer as needed.

[4-2. method for producing Single-layer photoreceptor ]

In the method for producing a single-layer photoreceptor, a coating liquid for forming a photosensitive layer (hereinafter, sometimes referred to as a coating liquid for a photosensitive layer) is prepared in a photosensitive layer forming step. The coating liquid for photosensitive layer is applied to a conductive substrate to form a coating film. Next, the coating film is dried by an appropriate method, and at least a part of the solvent contained in the coating film is removed to form the photosensitive layer. The coating liquid for photosensitive layer includes, for example: a charge generator, a hole transport agent, a polyarylate resin (1) as a binder resin, and a solvent. Such a coating liquid for photosensitive layers is prepared by, for example, dissolving or dispersing a charge generator, a hole transport agent, and a polyarylate resin (1) as a binder resin in a solvent. Various additives may be added to the coating liquid for photosensitive layer as required.

The photosensitive layer forming step will be described in detail below. The solvent contained in the coating liquid for the charge generating layer, the coating liquid for the charge transporting layer, and the coating liquid for the photosensitive layer (hereinafter, these three coating liquids may be referred to as coating liquids) is not particularly limited as long as it can dissolve or disperse each component contained in the coating liquids. Examples of the solvent include: alcohols (more specifically, methanol, ethanol, isopropanol, butanol, or the like), aliphatic hydrocarbons (more specifically, n-hexane, octane, cyclohexane, or the like), aromatic hydrocarbons (more specifically, benzene, toluene, xylene, or the like), halogenated hydrocarbons (more specifically, dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene, or the like), ethers (more specifically, dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, or the like), ketones (more specifically, acetone, methyl ethyl ketone, cyclohexanone, or the like), esters (more specifically, ethyl acetate, methyl acetate, or the like), dimethyl formaldehyde, dimethyl formamide, or dimethyl sulfoxide. These solvents may be used alone or in combination of two or more. Among these solvents, halogen-free solvents are preferably used.

The solvent contained in the coating liquid for charge transport layer is preferably different from the solvent contained in the coating liquid for charge generation layer. In the production of a laminated photoreceptor, a charge generation layer and a charge transport layer are usually formed in this order, and therefore a charge transport layer coating solution is applied to the charge generation layer. In forming the charge transport layer, the charge generation layer is required not to be dissolved in the solvent of the coating liquid for charge transport layer.

The coating liquid is prepared by mixing the respective components and dispersing in a solvent. The mixing or dispersing can be carried out, for example, using a bead mill, roll mill, ball mill, attritor, paint shaker or ultrasonic disperser.

The coating liquid may contain, for example, a surfactant or a leveling agent in order to improve the dispersibility of each component or the surface flatness of each layer formed.

The method for applying the coating liquid is not particularly limited as long as the coating liquid can be uniformly applied. Examples of the coating method include: dip coating, spray coating, spin coating or bar coating.

The method for removing at least a part of the solvent contained in the coating liquid is not particularly limited as long as the solvent in the coating liquid can be evaporated. Examples of the removal method include: heating, reducing pressure or both heating and reducing pressure. More specifically, for example, a method of performing heat treatment (hot air drying) using a high-temperature dryer or a reduced-pressure dryer. The heat treatment conditions are, for example, a temperature of 40 ℃ to 150 ℃ and a time of 3 minutes to 120 minutes.

The method for manufacturing the photoreceptor may further include a step of forming an intermediate layer, if necessary. The step of forming the intermediate layer may be appropriately selected from known methods.

The electrophotographic photoreceptor of the present invention described above is excellent in abrasion resistance, and therefore can be preferably used in various image forming apparatuses.

[ examples ] A method for producing a compound

The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following embodiments.

The following charge generating agent, hole transporting agent, and binder resin were prepared as materials for manufacturing the laminated photoreceptor.

(Charge generating agent)

The charge generating agent (CGM-2) explained in the second embodiment was prepared. The charge generating agent (CGM-2) is oxytitanium phthalocyanine (Y-type oxytitanium phthalocyanine crystal) represented by the chemical formula (CGM-2). The crystal structure is Y-type.

In the CuK α characteristic X-ray diffraction spectrum, the Y-type oxytitanium phthalocyanine crystal has peaks at bragg angles 2 θ ± 0.2 ° of 9.2 °, 14.5 °, 18.1 °, 24.1 °, and 27.2 °, and the main peak is 27.2 °. The CuK α characteristic X-ray diffraction spectrum is measured by the measurement device and the measurement conditions described in the embodiments.

[ Synthesis of oxytitanium phthalocyanine ]

The Y-type oxytitanium phthalocyanine crystal is prepared as follows. First, oxytitanium phthalocyanine is synthesized. To an argon-substituted flask were added 22g (0.17mol) of phthalonitrile, 25g (0.073mol) of tetrabutyl titanate, 300g of quinoline and 2.28g (0.038mol) of urea. While the contents of the flask were stirred, the internal temperature of the flask was raised to 150 ℃.

Subsequently, while the vapor generated from the reaction system was evaporated to the outside of the reaction system, the temperature was raised to 215 ℃. Then, the internal temperature of the flask was maintained at 215 ℃ for 2 hours, and the contents of the flask were stirred to react. After the reaction was completed, the contents were taken out from the flask while the internal temperature of the flask was cooled to 150 ℃. The contents were filtered through a glass filter to obtain a solid. The solid was washed with N, N-dimethylformamide and methanol in this order. Vacuum drying was then carried out to obtain 24g of a bluish-purple solid.

[ production of Y-type oxytitanium phthalocyanine crystals ]

Next, a Y-type oxytitanium phthalocyanine crystal is prepared. The preparation is carried out with pigment pretreatment and pigment treatment.

(pigmenting pretreatment)

12g of a bluish-purple solid was added to the reaction vessel and added to 100ml of N, N-dimethylformamide. While stirring the contents of the reaction vessel, the internal temperature of the reaction vessel was raised to 130 ℃ and maintained at 130 ℃, and further stirred for 2 hours. Then, the temperature holding was stopped after 2 hours had elapsed, and the reaction vessel was cooled. The stirring was stopped when the internal temperature of the reaction vessel reached 23. + -. 1 ℃. In this state, the contents of the reaction vessel were left to stand for 12 hours to perform stabilization treatment. The supernatant of the stabilized contents was then filtered through a glass filter to give a solid. The solid was washed with methanol and then dried under vacuum. As a result, 11.8g of crude crystals of oxytitanium phthalocyanine were obtained.

(pigmentation treatment)

A solution was prepared by adding 10g of crude crystals of oxytitanium phthalocyanine to 100g of 97 wt% concentrated sulfuric acid and dissolving it. Further, the above acid treatment was carried out at 5 ℃ for 1 hour. Then, the solution was dropped into 5L of pure water under ice cooling at a rate of 10mL per minute. Then, the mixture was stirred at about 15. + -. 3 ℃ for 30 minutes and then allowed to stand for 30 minutes. Next, the solution was filtered through a glass filter to obtain a wet cake.

Subsequently, the wet cake was suspended in 500mL of methanol to wash, and the methanol was filtered through a glass filter. Then, the above washing was performed 4 times, and then the wet cake was suspended in 500mL of pure water at 20 ℃ to be washed, and the water after washing was filtered through a glass filter.

Next, 5g of the wet cake after washing was added to the mixed solvent to obtain a solution. The mixed solvent contained 0.75g of water and 100g of chlorobenzene. The solution was heated at 50 ℃ for 24 hours and stirred. The supernatant was filtered through a glass filter to obtain crystals. The crystals were washed on the funnel with 100mL of methanol. Then, vacuum drying was carried out at 50 ℃ for 5 hours to obtain 4.5g of Y-type oxytitanium phthalocyanine crystal (cyan powder) represented by the formula (CGM-2).

(hole transport agent)

The hole-transporting agents (HTM-1) to (HTM-9) described in the second embodiment were prepared.

(polyarylate resin)

In addition to the polyarylate resins (Resin-1) to (Resin-7) described in the first embodiment, polyarylate resins (Resin-8) to (Resin-11) were prepared. The polyarylate resins (Resin-8) to (Resin-11) are represented by the chemical formulas (Resin-8) to (Resin-11), respectively.

[ CHEM 33 ]

[ CHEM 34 ]

[ CHEM 35 ]

[ CHEM 36 ]

(method for synthesizing polyarylate resins (Resin-1) to (Resin-7))

Next, the method for synthesizing polyarylate resins (Resin-1) to (Resin-7) will be described.

[ production of polyarylate Resin (Resin-1) ]

A three-necked flask was used as a reaction vessel. The reaction vessel was a three-necked flask having a capacity of 1L and equipped with a thermometer, a three-way valve and a 200mL titration funnel. To the reaction vessel were added 31.25g (82.56 mmol) of 9, 9-bis (3-methyl-4-hydroxyphenyl) fluorene, 0.124g (0.826 mmol) of tert-butylphenol, 7.84g (196 mmol) of sodium hydroxide, and 0.240g (0.768 mmol) of benzyltributylammonium chloride. Then, the inside of the reaction vessel was replaced with argon. Then, 600mL more water was added to the reaction vessel. The contents of the reaction vessel were stirred for 1 hour at an internal temperature of the reaction vessel of 20 ℃. Subsequently, the contents of the reaction vessel were cooled to lower the internal temperature of the reaction vessel to 10 ℃. Thereby preparing an alkaline aqueous solution.

A chloroform solution was prepared by dissolving 9.84g (38.9 mmol) of 2, 6-naphthalenedicarboxylic dichloride (2, 6-Naphthalene dicarbonyldichloride) and 11.47g (38.9 mmol) of 4, 4 '-chloroformylphenyl ether (4, 4' -Oxydibenzoyl chloride) in 300g of chloroform (pentene additive).

Next, the internal temperature of the reaction vessel of the alkaline aqueous solution was maintained at 10 ℃, and the contents of the reaction vessel were stirred. The chloroform solution was added to the aqueous alkaline solution to start the polymerization reaction. In the polymerization reaction, the internal temperature of the reaction vessel was maintained at 13. + -. 3 ℃ for 3 hours while stirring the contents of the reaction vessel. Then, the upper layer (aqueous layer) was removed with a decanter to obtain an organic layer.

A2L Erlenmeyer flask was used as a reaction vessel. After 500mL of ion-exchanged water was added to the reaction vessel, the organic layer was added. Further, 300g of chloroform and 6mL of acetic acid were added to the reaction vessel. The contents of the reaction vessel were stirred at room temperature (25 ℃) for 30 minutes. Subsequently, the upper layer (aqueous layer) was removed by a decanter to obtain an organic layer. Subsequently, the organic layer was washed 8 times with 500mL of ion-exchanged water through a separatory funnel.

The organic layer after washing was taken out by liquid separation. The organic layer was filtered to obtain a filtrate. A beaker with a capacity of 3L was charged with 1.5L of methanol. The organic layer was slowly dropped while stirring methanol to obtain a precipitate. The precipitate was filtered off by filtration. The precipitate obtained was dried in vacuo at a temperature of 70 ℃ for 12 hours. As a result, a polyarylate Resin (Resin-1) was obtained. The yield of the polyarylate Resin (Resin-1) was 39.7g, and the yield was 88.1%.

[ production of polyarylate resins (Resin-2) to (Resin-7) ]

Polyarylate resins (Resin-2) to (Resin-7) were produced in the same manner as the polyarylate Resin (Resin-1) except that 9, 9-bis (3-methyl-4-hydroxyphenyl) fluorene (bistresolfluorene) was changed to an aromatic diol as a starting material of the polyarylate resins ((Resin-2) to (Resin-7)), and 2, 6-naphthalenedicarboxylic acid dichloride (2, 6-Naphthalene dicarboxylic chloride) and 4, 4 '-chloroformylphenyl ether (4, 4' -Oxydibenzoylchloride) were changed to an alkanoyl halide (alkanylhalide) as a starting material of the polyarylate resins ((Resin-2) to (Resin-7)). The amount of the starting material in the production of polyarylate resins (Resin-2) to (Resin-7) was the same as that in the production of polyarylate resins. Here, the amount of the starting material means the total amount of the aromatic dicarboxylic acid and the amount of the aromatic diol.

Next, the polyarylate resins (Resin-1) to (Resin-7) were prepared by proton nuclear magnetic resonance spectroscopy (300 MHz, manufactured by Nippon spectral Co., Ltd.)¹H-NMR spectrum was measured. Adding CDCl₃Is used as a solvent. Tetramethylsilane (TMS) was used as an internal standard. A typical example of these is a polyarylate Resin (Resin-1). The chemical shift value of the polyarylate Resin (Resin-1) is shown below. Polyarylate Resin (Resin-1):¹H-NMR(300MHz，CDCl₃)δ＝8.81(s，1H)，8.26 (d，1H)，8.20(d，2H)，8.09(d，1H)，7.74-7.80(m，2H)，7.28-7.48(m， 7H)，6.99-7.18(m，7H)，2.11-2.18(m，6H)。

FIG. 2 shows the preparation of polyarylate Resin (Resin-1)¹H-NMR spectrum. In FIG. 2, the horizontal axis represents chemical shift (unit: ppm) and the vertical axis represents signal intensity (unit: arbitrary unit). According to¹It was confirmed by H-NMR spectrum and chemical shift value that polyarylate Resin (Resin-1) was obtained. The same applies to the other polyarylate resins (Resin-2) to (Resin-7)¹It was confirmed by H-NMR spectrum and chemical shift values that polyarylate resins (Resin-2) to (Resin-7) were obtained.

Production of photoreceptor

[ photoreceptor (A-1) ]

The production of the photoreceptor (a-1) according to example 1 will be described below.

(formation of intermediate layer)

First, a surface-treated titanium dioxide (sample SMT-A, manufactured by Tayca K.K., average primary particle diameter 10nm) was prepared. Specifically, titanium dioxide is surface-treated with alumina and silica, and the surface-treated titanium dioxide is subjected to wet dispersion and surface treatment with polymethylhydrosiloxane, and the titanium dioxide thus obtained is the prepared titanium dioxide. Next, the surface-treated titanium dioxide (2 parts by mass) and a polyamide resin AMILAN (registered trademark of japan) (product of tokyo corporation, CM 8000) (1 part by mass) were added to the mixed solvent. The mixed solvent is a solvent containing methanol (10 parts by mass), butanol (1 part by mass), and toluene (1 part by mass). AMILAN is a quaternary copolymerized polyamide resin of polyamide 6, polyamide 12, polyamide 66 and polyamide 610. These materials (surface-treated titanium dioxide and AMILAN) and the mixed solvent were mixed for 5 hours by a bead mill to disperse the materials in the mixed solvent. Thus, a coating liquid for an intermediate layer was prepared.

The obtained coating liquid for an intermediate layer was filtered through a filter having a pore size of 5 μm. Then, a coating liquid for an intermediate layer is applied to the surface of the conductive substrate by a dip coating method to form a coating film. An aluminum drum-shaped support (30 mm in diameter, 246mm in total length, maximum height Ry of 0.2 mirror surface capillary) was used as the conductive substrate. Subsequently, the coating film was dried at 130 ℃ for 30 minutes to form an intermediate layer (film thickness: 1.5 μm) on the conductive substrate.

(formation of Charge generating layer)

Y-type oxytitanium phthalocyanine crystal (1.5 parts by mass) and polyvinyl acetal (S-LEC BX-5, manufactured by Hydrocarbon chemical Co., Ltd.) (1 part by mass) as a matrix resin were added to the mixed solvent. The mixed solvent includes a solvent of propylene glycol monomethyl ether (40 parts by mass) and tetrahydrofuran (40 parts by mass). These materials (Y-type oxytitanium phthalocyanine crystal and polyvinyl acetal resin) and a mixed solvent were mixed for 12 hours by a bead mill, and the materials were dispersed in the mixed solvent to prepare a coating liquid for a charge generating layer. The obtained coating solution for charge generation layer was filtered with a filter having a pore size of 3 μm. Next, the obtained filtrate was applied to the intermediate layer formed as described above by a dip coating method to form a coating film. The coated film was dried at 50 ℃ for 5 minutes. Thus, a charge generation layer (film thickness 0.3 μm) was formed on the intermediate layer.

(formation of Charge transport layer)

50 parts by mass of a hole transporting agent (HTM-1), 2 parts by mass of a hindered phenol antioxidant ("IRGANOX (Japanese registered trademark) 1010" manufactured by BASF corporation) as an additive, 2 parts by mass of 3, 3 ', 5, 5 ' -tetra-tert-butyl-4, 4 ' -diphenoquinone as an electron acceptor compound, and 100 parts by mass of polyarylate Resin (Resin-1) (viscosity average molecular weight 40,000) as a binder Resin were added to the mixed solvent. The mixed solvent is a solvent containing 550 parts by mass of tetrahydrofuran and 150 parts by mass of toluene. These materials (hole transport agent (HTM-1), hindered phenol antioxidant, 3 ', 5, 5 ' -tetra-tert-butyl-4, 4 ' -diphenoquinone, and polyarylate Resin (Resin-1)) and a mixed solvent were mixed for 12 hours, and the materials were dispersed in the mixed solvent to prepare a coating liquid for a charge transport layer.

The coating liquid for charge transport layer was applied to the charge generation layer by the same operation as the coating liquid for charge generation layer to form a coating film. Then, the coating film was dried at 120 ℃ for 40 minutes to form a charge transport layer (film thickness: 20 μm) on the charge generating layer. Thus, photoreceptor (A-1) was obtained. The photoreceptor (a-1) is a laminated photoreceptor, and has a structure in which an intermediate layer, a charge generation layer, and a charge transport layer are laminated in this order on a conductive substrate.

[ photoreceptors (A-2) to (A-15) and photoreceptors (B-1) to (B-4) ]

The hole-transporting agent (HTM-1) was replaced with the hole-transporting agent described in Table 1. The binder Resin described in Table 1 was used in place of the polyarylate Resin (Resin-1). Thus, photoreceptors (A-2) to (A-15) and photoreceptors (B-1) to (B-4) were obtained, respectively. Table 1 shows the structures of the photoreceptors (A-1) to (A-15) and the photoreceptors (B-1) to (B-4). In Table 1, HTM-1 to HTM-9 in the column "type of hole-transporting agent" represent hole-transporting agents (HTM-1) to (HTM-9), respectively. Resin-1 to Resin-11 in the column "type of binder Resin" represent polyarylate resins (Reisn-1) to (Resin-11), respectively. The column "molecular weight of the binder resin" indicates the viscosity-average molecular weight of the binder resin.

[ evaluation of photoreceptor Properties ]

< evaluation of film formation resistance >

(image evaluation)

Any of the photoreceptors (A-1) to (A-15) and photoreceptors (B-1) to (B-4) was set in the evaluation apparatus. The evaluation equipment was a change machine (a change machine manufactured by showa data corporation "color printer C711 dn"). The toner cartridge of the evaluation apparatus was filled with cyan toner. In a high-temperature and high-humidity environment (temperature 32 ℃ and relative humidity 85% RH, hereinafter, sometimes referred to as HH environment), 2,000 sheets were printed at 16-second intervals. Next, 2,000 pages were printed in a low-temperature and low-humidity environment (temperature 10 ℃ and relative humidity 15% RH, hereinafter, may be referred to as LL environment). Then, after standing for 2 hours, 1 solid image (image density 100%) was printed under LL atmosphere. The solid image was taken as an evaluation image. The evaluation image was visually observed to confirm whether or not film formation occurred, and the film formation resistance was evaluated in accordance with the following criteria.

(evaluation criteria)

○ (good), no image defect (filming) was observed.

X (poor): the image was confirmed to be defective (film formation).

(film Forming Rate)

[ production of image on photoreceptor surface ]

After the printing was completed (after the evaluation image was created in the image evaluation), the photoreceptor was taken out from the image forming apparatus, and the degree of occurrence of toner filming on the surface of the photoreceptor was observed. Specifically, the surface of the photoreceptor was observed with an optical microscope ("inner K · K (it ナ -K · K)", manufactured by Nikon corporation) to obtain an observation image. The optical microscope had an angle of view of 1.7 mm. times.2.1 mm and a magnification of 50 times. The observation positions of the photoreceptor are three positions 25mm from the upper end, the center portion and 25mm from the lower end of the photoreceptor, which are described below.

Measurement site 1: center part of the photoreceptor

Measurement site 2: a part which moves 20mm from the upper end surface in the direction from the upper end surface to the lower end surface of the photoreceptor

Measurement site 3: a part 20mm shifted from the lower end surface of the photoreceptor in the direction from the lower end surface to the upper end surface

[ image processing ]

Binarization processing is performed on the observation image. Specifically, the observation Image is subjected to binarization processing by Image analysis software (Image J), and the threshold value of the binarization processing is a luminance value 180. Each pixel constituting the observation image has a luminance value of 0 to 255. Pixels having a luminance value smaller than the threshold value and a region where toner filming occurs. On the other hand, pixels having luminance values equal to or higher than the threshold value correspond to regions where toner filming has not occurred.

The binarized image was subjected to image analysis, and the ratio of the area of the deposit to the entire image was calculated. Specifically, the area (At) of the region where toner filming occurred and the area (An) of the region where toner filming did not occur were obtained by the binarization process. From the obtained At and An, the area ratio (a) of the region where the toner was formed was obtained according to equation 1.

Area ratio a [% ] [ ((At/(At + An) ] × 100 … … (equation 1)

The area ratio a of the observed image at the position 3 of the photoreceptor was obtained. The area ratios a of the measurement sites 1, 2, and 3 thus obtained were area ratios a1, a2, and A3, respectively. The average value of the area ratios a1, a2, and A3 "(a 1+ a2+ A3)/3") was calculated, and the obtained average value was used as the film formation rate as the evaluation result of the toner filming resistance.

When the filming rate is sufficiently small, no toner filming occurs on the surface of the photoreceptor. For example, if the film formation rate is 5.0% or less, the formed image is less likely to have image defects.

< evaluation of Electrical characteristics >

(charged potential V)₀Measurement of (2)

Any of the photoreceptors (A-1) to (A-15) and photoreceptors (B-1) to (B-4) were charged by a drum sensitivity tester (manufactured by GENTEC corporation) at a rotation speed of 31rpm and a current flowing into the drum of-10. mu.A. The surface potential of the photoreceptor was measured. The measured surface potential is taken as the charging potential (V)₀). The measurement environment was at a temperature of 23 ℃ and a relative humidity of 50% RH.

(light sensitivity potential V)_LMeasurement of (2)

Any of the photoreceptors (A-1) to (A-15) and photoreceptors (B-1) to (B-4) were charged at a rotation speed of 31rpm and a charging potential of-600V by a drum sensitivity tester (manufactured by GENTEC corporation). Then, monochromatic light (wavelength of 780nm, exposure amount of 0.8. mu.J/cm) was extracted from the light of the halogen lamp using a band-pass filter²) The surface of the photoreceptor is irradiated. After the irradiation of the monochromatic light was completed, the surface potential after 80 milliseconds was measured. The measured surface potential was taken as a sensitivity potential (V)_L). The measurement environment was at a temperature of 23 ℃ and a relative humidity of 50% RH.

Table 1 shows the charging potentials V of the photoreceptors (A-1) to (A-15) and the photoreceptors (B-1) to (B-4)₀A light sensitivity potential V_LFilm formation rate and image evaluation results.

[ TABLE 1 ]

As shown in Table 1, the photoreceptors (A-1) to (A-15) had charge transport layers containing either one of polyarylate resins (Resin-1) to (Resin-7) as a binder Resin, the polyarylate resins (Resin-1) to (Resin-7) had repeating units represented by the general formula (1), and as shown in Table 1, all of the photoreceptors (A-1) to (A-15) had an evaluation result of film formation resistance of ○ (good).

As shown in Table 1, in the photoreceptors (B-1) to (B-4), the charge transport layer contained any one of polyarylate resins (Resin-8) to (Resin-11) as a binder Resin. The polyarylate resins (Resin-8) to (Resin-11) do not have the repeating unit represented by the general formula (1). As shown in Table 1, all of the evaluation results of the filming resistance of the photoreceptors (B-2) to (B-3) were X (poor). The photoreceptors (B-1) and (B-4) could not be evaluated for filming resistance. Specifically, in the photoreceptor (B-1), the binder Resin (Resin-8) was not sufficiently dissolved in the solvent, and the coating liquid for the charge transporting layer could not be prepared. In the photoreceptor (B-4), the coating liquid for the charge transport layer gelled, and a photosensitive layer could not be formed.

As is clear from Table 1, the polyarylate resins (Resin-1) to (Resin-7) represented by the general formula (1) have improved film formation resistance of the photoreceptor as compared with the polyarylate resins (Resin-9) to (Resin-11). Further, the photoreceptors (a-1) to (a-15)) containing the polyarylate resin represented by the general formula (1) have excellent filming resistance as compared with the photoreceptors (B-1) to (B-4)) not containing the polyarylate resin represented by the general formula (1). Therefore, it is apparent that the photoreceptor according to the present invention is excellent in film formation resistance.

Claims (10)

1. A polyarylate resin composition comprising a polyarylate resin,

represented by the following general formula (1),

[ CHEM 1 ]

In the general formula (1) described above,

R¹、R²、R³and R⁴Each independently represents a hydrogen atom or a methyl group,

r, s, t and u all represent positive integers,

r+s+t+u＝100，

r+t＝s+u，

r/(r + t) is 0.10 to 0.70,

s/(s + u) is 0.10 to 0.70,

x represents a divalent group represented by formula (2A), formula (2B), formula (2C) or formula (2D),

y represents a divalent group represented by formula (4A), formula (4B), formula (4C), formula (4D) or formula (4E),

x and Y are different from each other,

[ CHEM 2 ]

[ CHEM 3 ]

2. The polyarylate resin according to claim 1,

in the general formula (1) described above,

R¹、R²、R³and R⁴Represents a methyl group.

3. The polyarylate resin according to claim 1 or 2,

in the general formula (1) described above,

x represents the divalent group represented by the general formula (2A) or the general formula (2B), or Y represents the divalent group represented by the general formula (4A) or the general formula (4B).

4. The polyarylate resin according to claim 1 or 2,

in the general formula (1) described above,

x represents the divalent group represented by the general formula (2A) or the general formula (2B),

y represents the divalent group represented by the general formula (4A), the general formula (4B) or the general formula (4E).

5. The polyarylate resin according to claim 1,

represented by chemical formula (Resin-1), chemical formula (Resin-2), chemical formula (Resin-3), chemical formula (Resin-4), chemical formula (Resin-5), chemical formula (Resin-6) or chemical formula (Resin-7),

[ CHEM 4 ]

[ CHEM 5 ]

[ CHEM 6 ]

[ CHEM 7 ]

[ CHEM 8 ]

[ CHEM 9 ]

[ CHEM 10 ]

6. The polyarylate resin according to claim 1 or 2,

in the general formula (1), Y represents a divalent group represented by the chemical formula (4C).

7. The polyarylate resin according to claim 1 or 2,

represented by the chemical formula (Resin-1),

[ CHEM 11 ]

8. The polyarylate resin according to claim 1 or 2,

represented by the chemical formula (Resin-3),

[ CHEM 12 ]

9. The polyarylate resin according to claim 1 or 2,

represented by the chemical formula (Resin-4),

[ CHEM 13 ]

10. The polyarylate resin according to claim 1,

represented by the chemical formula (Resin-7),

[ CHEM 14 ]

Images