JP2009007274A - Diamine derivative and electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diamine derivative having high sensitivity as a positive hole transporting agent of an electrophotographic photoreceptor, and to provide the electrophotographic photoreceptor having excellent sensitivity. <P>SOLUTION: The diamine derivative is the meta-diaminobenzene derivative having a 4-(2'-phenylethenyl)phenyl group and 4-[4'-(2"-phenylethenyl)phenylethenyl]phenyl group on nitrogen. The electrophotographic photoreceptor uses the derivative as the positive hole transporting material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diamine derivative and an electrophotographic photoreceptor.

  As an electrophotographic photoreceptor used in an image forming apparatus or the like, an electrophotographic photoreceptor having a conductive substrate and a photoreceptor layer provided on the conductive substrate is known. The electrophotographic photosensitive member is formed by applying a hole transporting agent, a charge generating agent, a binder resin and, if necessary, a coating solution in which an electron transporting agent is dissolved in a solvent, onto a conductive substrate, and drying it to sensitize it. Manufactured by forming a body layer.

  Diamine derivatives are known as hole transport agents. As the diamine derivative, for example, a compound represented by the following formula (2-1) is known (for example, see Patent Document 1).

However, the compound represented by the formula (2-1) has poor solubility in a solvent and compatibility with a binder resin, and has insufficient sensitivity as a hole transporting agent for an electrophotographic photoreceptor. As a result, the sensitivity of the obtained electrophotographic photosensitive member was insufficient.
JP 2004-252001 A

  Accordingly, an object of the present invention is to provide a diamine derivative having high sensitivity as a hole transport agent of an electrophotographic photoreceptor and an electrophotographic photoreceptor excellent in sensitivity.

  The diamine derivative of the present invention is a compound represented by the following formula (1).

In formula (1), Ar ¹ has a divalent group generated by removing one hydrogen atom from an alkyl group which may have one or more substituents, and one or more substituents. A divalent group generated by removing one hydrogen atom from the aryl group which may be present, or a heterocyclic group optionally having one or more substituents, Ar ^2a and Ar ^2b are each An aryl group optionally having one or more substituents or a heterocyclic group optionally having one or more substituents, wherein R ^{1a to} R ^12a and R ^{1b to} R ^12b are each hydrogen; Atom, halogen atom, alkyl group optionally having one or more substituents, aryl group optionally having one or more substituents, optionally having one or more substituents May have an alkoxy group or one or more substituents An aralkyl ^group, R 13a ^{to R 16a} and ^R 13b ^{to R 16b} are each a hydrogen atom, one or more substituents alkyl group that may have a may have one or more substituents An aryl group, an alkoxy group optionally having one or more substituents, or an aralkyl group optionally having one or more substituents, and m and n are each an integer of 0 or more. However, Ar <^2a> , Ar ^<2b> , R < ^1a > -R < ^16a > and R ^<1b > -R <^16b> are respectively the same or different.

  The electrophotographic photoreceptor of the present invention has a conductive substrate and a photoreceptor layer provided on the conductive substrate, and the photoreceptor layer is a layer containing the diamine derivative of the present invention. It is characterized by.

The diamine derivative of the present invention has high sensitivity as a hole transport agent for an electrophotographic photoreceptor. In addition, according to the diamine derivative of the present invention, an electrophotographic photoreceptor excellent in sensitivity can be obtained.
The electrophotographic photoreceptor of the present invention is excellent in sensitivity.

<Diamine derivative>
The diamine derivative of the present invention is a compound represented by the following formula (1). Hereinafter, the compound represented by Formula (1) is referred to as Compound (1). Other compounds are described in the same manner.

Ar ¹ is a divalent group formed by removing one hydrogen atom from an alkyl group which may have one or more substituents, and an aryl which may have one or more substituents A divalent group generated by removing one hydrogen atom from a group, or a heterocyclic group optionally having one or more substituents.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group.
Examples of the aryl group include phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, anthryl group, phenanthryl group and the like.
Examples of the heterocyclic group include a pyridine ring, a pyrrolidine ring, a thiophene ring, a pyrrole ring, a thiazole ring, an imidazole ring, and a pyrazole ring.
Ar ¹ is preferably a divalent group generated by removing one hydrogen atom from an aryl group, and more preferably a divalent group generated by removing one hydrogen atom from a phenyl group.

Ar ^2a and Ar ^2b are each an aryl group which may have one or more substituents, or a heterocyclic group which may have one or more substituents. However, Ar ^2a and Ar ^2b may be the same or different.
Examples of the aryl group and heterocyclic group include the various aryl groups and heterocyclic groups exemplified above.
As Ar ^2a and Ar ^2b , an aryl group is preferable, and a phenyl group is particularly preferable.

R ^{1a to} R ^12a and R ^{1b to} R ^12b are each a hydrogen atom, a halogen atom, an alkyl group that may have one or more substituents, or an aryl that may have one or more substituents. A group, an alkoxy group optionally having one or more substituents, or an aralkyl group optionally having one or more substituents. However, R ^{1a to} R ^12a and R ^{1b to} R ^12b may be the same or different.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, t-butoxy, pentyloxy, isopentyloxy, neopentyloxy, hexyl An oxy group etc. are mentioned.
Examples of the aralkyl group include benzyl group, α-methylbenzyl group, phenethyl group, styryl group, cinnamyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group, and 6-phenylhexyl group. .
Examples of the alkyl group and aryl group include the various alkyl groups and aryl groups exemplified above.
The R ^1a to R ^12a and ^R 1b ^{to R 12b,} hydrogen atom is preferable.

R ^{13a to} R ^16a and R ^{13b to} R ^16b are each a hydrogen atom, an alkyl group optionally having one or more substituents, an aryl group optionally having one or more substituents, one An alkoxy group optionally having the above substituents or an aralkyl group optionally having one or more substituents. However, R ^{13a to} R ^16a and R ^{13b to} R ^16b may be the same or different.
Examples of the halogen atom, alkyl group, aryl group, alkoxy group and aralkyl group include various halogen atoms, alkyl groups, aryl groups, alkoxy groups and aralkyl groups exemplified above.
As R ^<13a > -R <^16a> and R ^<13b > -R < ^16b >, a hydrogen atom is preferable.

  m and n are each an integer of 0 or more, and 0 to 3 are preferable from the viewpoint of synthesis.

Examples of compound (1) include compounds (1-1) and (1-2).
In addition, as a specific example of the compound (1), a bilaterally symmetric compound centered on Ar ¹ such as the compounds (1-1) and (1-2) was exemplified, but as described above, Ar ^2a , Ar ^2b , R ^{1a to} R ^16a and R ^{1b to} R ^16b are the same or different. Therefore, in the present invention, the compound (1) is not limited to a symmetrical compound. However, considering the ease of synthesis, a symmetrical compound is preferred.

Compound (1) is produced, for example, as follows. In the reaction formula, X ^{1 to} X ⁴ are halogen atoms, and Ar ¹ , Ar ^2a , Ar ^2b , R ^{1a to} R ^16a , R ^{1b to} R ^16b , m, and n are the same as those in the formula (1). is there.

(A-1) Step:
Compound (3) and triethyl phosphite are reacted to form compound (4), and unreacted triethyl phosphite is distilled off under reduced pressure.

  The reaction ratio (molar ratio) between the compound (3) and triethyl phosphite is preferably 1: 1 to 1: 2.5. If there is too little triethyl phosphite, unreacted compound (3) remains and purification becomes difficult. If there is too much triethyl phosphite, the cost increases. The reaction temperature is preferably 160 to 200 ° C., and the reaction time is preferably 2 to 6 hours. By setting it as this range, a desired reaction can be efficiently carried out with a relatively simple production facility.

(B-1) Step:
Compound (4) and compound (5) are reacted in a solvent in the presence of a base to give compound (6), and compound (6) is extracted and purified.

The reaction ratio (molar ratio) between the compound (4) and the compound (5) is preferably 1: 1 to 1: 2.5. When there is too little compound (4), the yield of compound (6) will decrease. If the amount of compound (4) is too large, the amount of unreacted compound (4) will increase, and purification of compound (6) may be difficult due to side reactions and the like.
The reaction temperature is preferably -20 to 30 ° C, and the reaction time is preferably 5 to 30 hours. By setting it as this range, a desired reaction can be efficiently carried out with a relatively simple production facility.

  Examples of the base include sodium alkoxides such as sodium methoxide and sodium ethoxide; metal hydrides such as sodium hydride and potassium hydride; metal salts such as n-butyllithium and the like. A base may be used individually by 1 type and may be used in combination of 2 or more type.

  The amount of the base added is preferably 1 to 1.5 mol with respect to 1 mol of compound (5). If the addition amount of the base is less than 1 mol, the reactivity between the compound (4) and the compound (5) may be significantly reduced. If the amount of the base added exceeds 1.5 mol, it may be difficult to control the reaction between the compound (4) and the compound (5).

  Examples of the solvent include ethers such as diethyl ether, tetrahydrofuran, and dioxane; halogenated hydrocarbons such as methylene chloride, chloroform, and dichloroethane; aromatic hydrocarbons such as benzene and toluene, and dimethylformamide.

(A-2) Process:
In the same manner as in the above step (a-1), the compound (7) is reacted with triethyl phosphite to obtain the compound (8), and unreacted triethyl phosphite is distilled off under reduced pressure. In addition, the reaction ratio (molar ratio) between the compound (7) and triethyl phosphite is preferably 1: 1 to 1: 2.5.

(B-2) Step:
In the same manner as in the above step (b-1), the compound (8) and the compound (9) are reacted in a solvent in the presence of a base to obtain a compound (10), and the compound (10) is extracted and purified. To do.
In addition, the reaction ratio (molar ratio) between the compound (8) and the compound (9) is preferably 1: 1 to 1: 2.5.
As the base and the solvent, the same as those in the step (b-1) can be mentioned.

(C-1) Step:
In the presence of a catalyst or the like, the compound (6) and the compound (11) are reacted in a solvent to obtain the compound (12), and the compound (12) is extracted and purified.

The reaction ratio (molar ratio) between the compound (6) and the compound (11) is preferably 2: 1 to 2.5: 1 when a = b. When there is too little compound (6), the yield of a compound (12) will decrease. If the amount of compound (6) is too large, the amount of unreacted compound (6) will increase, and purification of compound (12) may be difficult due to side reactions and the like.
The reaction temperature is preferably 80 to 140 ° C., and the reaction time is preferably 2 to 10 hours. By setting it as this range, a desired reaction can be efficiently carried out with a relatively simple production facility.

Examples of the catalyst include a palladium catalyst. Examples of the palladium-based catalyst include tris (dibenzylideneacetone) dipalladium (0). A catalyst may be used individually by 1 type and may be used in combination of 2 or more type.
Examples of the solvent include xylene.

(C-2) Step:
In the same manner as in the above step (c-1), the compound (12) and the compound (10) are reacted in a solvent in the presence of a catalyst or the like to obtain the compound (1), and the compound (1) is extracted. Purify.
In addition, the reaction ratio (molar ratio) between the compound (12) and the compound (10) is preferably 1: 2 to 1: 2.5 when a = b.
Examples of the catalyst and the solvent include the same as those in the step (c-1).

  In step (c-1) and step (c-2), compound (6) and compound (10) may be interchanged.

  In the compound (1) described above, one of the substituents bonded to the nitrogen atom of the diamine moiety has increased in number compared to the compound (2-1), so that the molecular weight is large, the conjugated system is expanded, Excellent solubility and compatibility with binder resin. Further, since three different substituents are bonded to one nitrogen atom, the solubility in a solvent and the compatibility with the binder resin are further improved. Therefore, compared with the compound (2-1), the sensitivity as a hole transport agent of the electrophotographic photoreceptor is excellent.

<Electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention has a conductive substrate and a photoreceptor layer provided on the conductive substrate, and the photoreceptor layer contains the diamine derivative (compound (1)) of the present invention. It is an electrophotographic photoreceptor which is a layer to be contained.

  Examples of the electrophotographic photoconductor include (i) a single-layer electrophotographic photoconductor and (ii) a laminated electrophotographic photoconductor, and can be used for either positive or negative charging type electrophotographic photoconductor. The reason is that the structure is simple, the production is easy, the film defects when forming the photoreceptor layer can be effectively suppressed, the interface between layers is small, and the optical characteristics are easy to improve. i) A single-layer electrophotographic photoreceptor is preferred.

(I) Single layer type electrophotographic photoreceptor:
FIG. 1 is a schematic sectional view showing an example of a single-layer electrophotographic photoreceptor. The single-layer type electrophotographic photoreceptor 10 includes a conductive substrate 12 and a photoreceptor layer 14 provided on the conductive substrate 12.
The single-layer electrophotographic photoreceptor 10 is not limited to that shown in FIG. 1, and as shown in FIG. 2, a single-layer electrophotographic photoreceptor is provided between the conductive substrate 12 and the photoreceptor layer 14. The barrier layer 16 may be provided as long as the characteristics of the photoreceptor 10 are not impaired, and a protective layer 18 may be provided on the surface of the photoreceptor layer 14 as shown in FIG.

Examples of the conductive substrate include metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass; Laminated plastic materials; glass coated with aluminum iodide, tin oxide, indium oxide or the like can be used.
Examples of the shape of the conductive substrate include a sheet shape and a drum shape. The shape of the conductive substrate may be appropriately determined according to the structure of the image forming apparatus.

The thickness of the photoreceptor layer is preferably 5 to 100 μm, and more preferably 10 to 50 μm.
The photoreceptor layer is a layer containing, for example, a hole transport agent, a charge generator, a binder resin, and, if necessary, an electron transport agent.

The photoreceptor layer contains the compound (1) as a hole transport agent.
The photoreceptor layer may contain another hole transport agent. Other hole transporting agents include triarylamine compounds excluding compound (1) and oxadiazole compounds such as 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole , Styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds, pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds Compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds, and other nitrogen-containing cyclic compounds, condensed polycyclic compounds, etc. It is done. A hole transport agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the charge generator include phthalocyanine pigments, perylene pigments, bisazo pigments, diketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine pigments, Organic photoconductors such as pyrylium pigment, ansanthrone pigment, triphenylmethane pigment, selenium pigment, toluidine pigment, pyrazoline pigment, quinacridone pigment; selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, amorphous silicon, etc. And inorganic photoconductive agents. A charge generating agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  As a charge generating agent, when a hole transporting agent and an electron transporting agent are used in combination, an electrophotographic photoreceptor having superior sensitivity characteristics, electrical characteristics, stability and the like can be obtained. Therefore, a metal-free phthalocyanine (τ type) Or X type), titanyl phthalocyanine (α type or Y type), hydroxygallium phthalocyanine (V type), and chlorogallium phthalocyanine (II type).

  As electron transport agents, quinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, 3,4,5,7-tetranitro-9-fluorenone derivatives, dinitroanthracene derivatives, dinitroacridine derivatives, nitroantharaquinone Derivatives, dinitroanthraquinone derivatives, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, dibromomaleic anhydride, etc. It is done. An electron transfer agent may be used individually by 1 type, and may be used in combination of 2 or more type.

As the electron transporting agent, a quinone derivative is preferable because it is excellent in electron acceptability and compatibility with a charge generating agent, and an electrophotographic photoreceptor excellent in sensitivity characteristics and durability can be obtained. Examples of quinone derivatives include naphthoquinone derivatives, diphenoquinone derivatives, azoquinone derivatives, and the like.
As the electron transfer agent, compounds (13-1) to (13-3) are particularly preferable.

  Examples of the binder resin include polycarbonate resins such as bisphenol Z type, bisphenol ZC type, bisphenol C type, and bisphenol A type, polyarylate resin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and styrene-maleic acid. Copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer Thermoplastic resins such as polymers, alkyd resins, polyamide resins, polyurethane resins, polysulfone resins, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyether resins; silicone resins, epoxy resins, phenol resins, Containing resins, thermosetting resins such as melamine resin, epoxy acrylate, urethane - photocurable resins such as acrylate. Binder resin may be used individually by 1 type, and may be used in combination of 2 or more type.

The photoreceptor layer may contain a known additive as long as the electrophotographic characteristics are not adversely affected. Examples of additives include antioxidants, radical scavengers, singlet quenchers, deterioration inhibitors such as ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers. , Wax, acceptor, donor and the like.
In order to improve the sensitivity of the photoreceptor layer, known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

20-500 mass parts is preferable with respect to 100 mass parts of binder resin, and, as for content of a hole transport agent, 30-200 mass parts is more preferable.
The content of the charge generating agent is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the binder resin.
When the electron transport agent is contained, the content of the electron transport agent is preferably 5 to 100 parts by mass and more preferably 10 to 80 parts by mass with respect to 100 parts by mass of the binder resin.

The photoreceptor layer is formed by, for example, applying a hole transporting agent, a charge generating agent, a binder resin, and, if necessary, a coating solution in which an electron transporting agent is dissolved or dispersed in a solvent on a conductive substrate and drying it. Is formed.
The coating liquid is prepared by dissolving or dispersing each component in a solvent using a roll mill, a ball mill, an attritor, a paint shaker, an ultrasonic disperser or the like. As a coating method, a known method may be used.

Examples of the solvent include alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; dichloromethane, dichloroethane, Halogenated hydrocarbons such as chloroform, carbon tetrachloride and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate Dimethylformaldehyde, dimethylformamide, dimethyl sulfoxide and the like. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
In order to improve the dispersibility of each component and the smoothness of the surface of the photoreceptor layer, a surfactant, a leveling agent, and the like may be added to the coating solution.

  Since the obtained single-layer electrophotographic photoreceptor contains the compound (1) in the photoreceptor layer, the residual potential is lowered and the sensitivity is high. Furthermore, when an electron transporting agent is contained in the photoreceptor layer, electrons are efficiently exchanged between the charge generating agent and the hole transporting agent, and the sensitivity and the like tend to be more stable.

(Ii) Laminated electrophotographic photoreceptor:
FIG. 4 is a schematic cross-sectional view showing an example of a laminated electrophotographic photoreceptor. The laminated electrophotographic photoreceptor 20 includes a conductive substrate 12, a charge generation layer 24 containing a charge generation agent provided on the conductive substrate 12, and a charge transport layer provided on the charge generation layer 24. 22. In the multilayer electrophotographic photoreceptor 20, the charge generation layer 24 and the charge transport layer 22 constitute a photoreceptor layer.

The laminated electrophotographic photoreceptor 20 is not limited to that shown in FIG. 4, and a charge transport layer 22 is provided on the conductive substrate 12 and the charge transport layer 22 is charged as shown in FIG. A generation layer 24 may be provided. However, since the charge generation layer 24 is thinner than the charge transport layer 22, the charge transport layer 22 is preferably provided on the charge generation layer 24 in order to protect the charge generation layer 24.
Examples of the conductive substrate include those similar to the single layer type electrophotographic photoreceptor.

The thickness of the charge generation layer is preferably from 0.01 to 5 μm, and more preferably from 0.1 to 3 μm.
The thickness of the charge transport layer is preferably 2 to 100 μm, and more preferably 5 to 50 μm.
The positive or negative charge type of the multilayer electrophotographic photoreceptor is selected depending on the order of formation of the charge generation layer and the charge transport layer and the type of charge transport agent used in the charge transport layer. For example, in a laminated electrophotographic photoreceptor in which a charge generation layer is provided on a conductive substrate and a charge transport layer is provided thereon, a hole transport agent such as compound (1) is used as a charge transport agent for the charge transport layer. When is used, the photoreceptor is a negatively charged type. In this case, the charge generation layer may contain an electron transport agent.

Examples of the charge generating agent, hole transporting agent, electron transporting agent, and binder are the same as those for the single-layer electrophotographic photoreceptor.
The content of the charge generation agent in the charge generation layer is preferably 5 to 1000 parts by mass, more preferably 30 to 500 parts by mass with respect to 100 parts by mass of the binder resin.
When the hole transport agent is contained in the charge generation layer, the content of the hole transport agent is preferably 10 to 500 parts by weight, and more preferably 50 to 200 parts by weight with respect to 100 parts by weight of the binder resin.

10-500 mass parts is preferable with respect to 100 mass parts of binder resin, and, as for content of the hole transport agent of a charge transport layer, 25-200 mass parts is more preferable.
When the electron transport agent is contained in the charge transport layer, the content of the electron transport agent is preferably 5 to 200 parts by weight, and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.

The charge generation layer is formed, for example, by means such as vapor deposition or coating.
The charge transport layer is formed by means such as coating as in the case of the photoreceptor layer of a single-layer electrophotographic photoreceptor.

  Thus, since the electrophotographic photoreceptor of the present invention has a photoreceptor layer containing the diamine derivative (1), it has excellent sensitivity.

Each evaluation in the examples was performed as follows.
(Electrical characteristics test)
The GENTEC Co. drum sensitivity tester, set up a single-layer type electrophotographic photoreceptor was as charges the single-layer type electrophotographic photoreceptor comprising an initial surface potential V ₀ which is + 700 V. Next, monochromatic light (light intensity 1.5 μJ / m ² ) having a wavelength of 780 nm (half-value width 20 nm) extracted from the white light of the halogen lamp using a band-pass filter is applied to the surface of the single-layer electrophotographic photoreceptor. Irradiation was performed for 5 seconds, and the surface potential at the time when 0.5 seconds elapsed from the start of exposure was measured, and this was defined as a residual potential V _r (V).
In addition, the exposure amount (half exposure amount, E _1/2 ) at which the post-exposure potential of the single-layer electrophotographic photosensitive member becomes 1/2 of the initial surface potential was determined. The smaller the half exposure amount, the higher the sensitivity of the single layer type electrophotographic photosensitive member.

[Production of Compound (1-1)]
(A-1) Step:
A 200 mL flask was charged with 20 g (0.10 mol) of the compound (3-1) and 20 g (0.12 mol) of triethyl phosphite and stirred for 8 hours while heating at 180 ° C. After cooling to room temperature, excess phosphorous triethyl ester was distilled off under reduced pressure to obtain 27 g of colorless oily compound (4-1) (yield 90%).

(B-1) Step:
Into a 500 mL two-necked flask, 15 g (0.05 mol) of the compound (4-1) was added, purged with argon gas, 100 mL of dry tetrahydrofuran (THF) and 9.4 g of 28% sodium methoxide (0.05 mol) at 0 ° C. ) And stirred for 30 minutes. Next, 8.5 g (0.04 mol) of the compound (5-1) was dissolved in 300 mL of dry THF and added to this reaction solution, followed by stirring at room temperature for 12 hours. Thereafter, the reaction solution was poured into ion exchange water, extracted with toluene, and the organic layer was washed 5 times with ion exchange water. Subsequently, after drying an organic layer with anhydrous sodium sulfate, it filtered and distilled off the solvent. Thereafter, the residue was purified by recrystallization with a mixed solvent of toluene 20 mL / methanol 100 mL to obtain 12 g of white crystalline compound (6-1) (yield 85%).

(A-2) Process:
A 200 mL flask was charged with 20 g (0.10 mol) of the compound (7-1) and 19 g (0.12 mol) of triethyl phosphite and stirred for 8 hours while heating at 180 ° C. After cooling to room temperature, excess phosphorous triethyl ester was distilled off under reduced pressure to obtain 27 g of colorless oily compound (8-1) (yield 90%).

(B-2) Step:
Into a 500 mL two-necked flask, 15 g (0.05 mol) of the compound (8-1) was added, purged with argon gas, 100 mL of dry tetrahydrofuran (THF) and 9.4 g of 28% sodium methoxide (0.05 mol) at 0 ° C. ) And stirred for 30 minutes. Next, 4.3 g (0.04 mol) of the compound (9-1) was dissolved in 300 mL of dry THF and added to this reaction solution, followed by stirring at room temperature for 12 hours. Thereafter, the reaction solution was poured into ion exchange water, extracted with toluene, and the organic layer was washed 5 times with ion exchange water. Subsequently, after drying an organic layer with anhydrous sodium sulfate, it filtered and distilled off the solvent. Thereafter, the residue was purified by recrystallization with a mixed solvent of 20 mL of toluene / 100 mL of methanol to obtain 9 g of white crystalline compound (10-1) (yield 85%).

(C-1) Step:
In a 1 L 2-neck flask, 10 g (0.03 mol) of the compound (6-1), 0.10 g (0.00028 mol) of (2-biphenyl) dicyclohexylphosphine, 0.13 g of tris (dibenzylideneacetone) dipalladium (0) (0.00014 mol), 8.0 g (0.08 mol) of sodium t-butoxide, and 1.6 g (0.15 mol) of compound (11-1) were added, 500 mL of distilled o-xylene was added, and argon gas replacement was performed. And stirred for 5 hours while heating at 120 ° C. After cooling to room temperature, the reaction solution (organic layer) was washed three times with ion-exchanged water, and the organic layer was dried and adsorbed using anhydrous sodium sulfate and activated clay. Thereafter, filtration was performed, xylene was distilled off under reduced pressure, and the residue was purified by column chromatography (developing solvent: chloroform / hexane) to obtain 9 g of light brown solid compound (12-1) (yield 85%). ).

(C-2) Step:
In a 300 mL two-necked flask, 7.0 g (0.0105 mol) of compound (12-1), 0.018 g (0.0000523 mol) of (2-biphenyl) dicyclohexylphosphine, tris (dibenzylideneacetone) dipalladium (0) 0 0.024 g (0.0000262 mol), sodium t-butoxide 1.5 g (0.0157 mol), and compound (10-1) 5.6 g (0.0216 mol) were added, distilled o-xylene 500 mL was added, and argon gas was added. Substitution was carried out and the mixture was stirred for 5 hours while heating at 120 ° C. After cooling to room temperature, the reaction solution (organic layer) was washed three times with ion-exchanged water, and the organic layer was dried and adsorbed using anhydrous sodium sulfate and activated clay. Thereafter, filtration was performed, xylene was distilled off under reduced pressure, and the residue was purified by column chromatography (developing solvent: chloroform / hexane) to obtain 8.0 g of a yellow crystalline compound (1-1) (yield 75). %).

Example 1
5 parts by mass of an X-type metal-free phthalocyanine as a charge generating agent, 60 parts by mass of the compound (1-1) as a hole transporting agent, and 100 parts by mass of a polycarbonate resin as a binder resin are added to 800 parts by mass of THF as a solvent. Then, it was mixed and dispersed in a ball mill for 50 hours to prepare a coating solution for a single-layer type photosensitive layer. Next, the coating solution is applied to a conductive substrate made of an aluminum base tube by a dip coating method and dried with hot air at 100 ° C. for 30 minutes to form a photosensitive layer having a thickness of 25 μm. A photoreceptor was obtained. The single layer type electrophotographic photoreceptor was subjected to an electrical property test. The results are shown in Table 1.

(Example 2)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 1 except that 50 parts by mass of the compound (13-1) as an electron transfer agent was added to the coating solution. The results are shown in Table 1.

(Example 3)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 2 except that the compound (13-2) was used instead of the compound (13-1) as the electron transport agent. The results are shown in Table 1.

Example 4
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 2 except that the compound (13-3) was used instead of the compound (13-1) as the electron transfer agent. The results are shown in Table 1.

[Production of Compound (1-2)]
Steps (a-1), (b-1), and (c-1) were performed in the same manner as compound (1-1).
(A-2) Process:
30 g of a colorless oily compound (8-2) was obtained in the same manner as the compound (1-1) except that 23 g (0.10 mol) of the compound (7-2) was used instead of the compound (7-1). Obtained (yield 90%).

(B-2) Step:
Instead of compound (8-1), 12 g of white crystalline compound (10-2) was obtained in the same manner as compound (1-1) except that 17 g (0.05 mol) of compound (8-2) was used. Obtained (yield 85%).

(C-2) Step:
Compound (1-2) in the form of a yellow solid in the same manner as Compound (1-1) except that 6.0 g (0.0216 mol) of Compound (10-2) was used instead of Compound (10-1) 8.7 g was obtained (75% yield).

(Example 5)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 1 except that the compound (1-2) was used instead of the compound (1-1) as the hole transport agent. The results are shown in Table 1.

(Example 6)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 5 except that 50 parts by mass of the compound (13-1) as an electron transfer agent was added to the coating solution. The results are shown in Table 1.

(Example 7)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 6 except that the compound (13-2) was used in place of the compound (13-1) as the electron transfer agent. The results are shown in Table 1.

(Example 7)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 6 except that the compound (13-3) was used instead of the compound (13-1) as the electron transfer agent. The results are shown in Table 1.

[Comparative Example 1]
(Comparative Example 1-1)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 1 except that the compound (2-1) was used instead of the compound (1-1) as the hole transport agent. The results are shown in Table 1.

(Comparative Example 2)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Comparative Example 1 except that 50 parts by mass of the compound (13-1) as an electron transfer agent was added to the coating solution. The results are shown in Table 1.

(Comparative Example 3)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Comparative Example 2 except that the compound (13-2) was used instead of the compound (13-1) as the electron transport agent. The results are shown in Table 1.

(Comparative Example 4)
A single-layer electrophotographic photoreceptor was produced and evaluated in the same manner as in Comparative Example 2 except that the compound (13-3) was used instead of the compound (13-1) as the electron transport agent. The results are shown in Table 1.

As is apparent from Table 1, the single-layer electrophotographic photoreceptor of the example had a lower residual potential and a small half-exposure amount than the single-layer electrophotographic photoreceptor of the comparative example.
On the other hand, the single layer type electrophotographic photoreceptor of the comparative example had a high residual potential, and the half-exposure amount was larger than that of the examples.

An electrophotographic photoreceptor using the diamine derivative of the present invention as a hole transporting agent was excellent in sensitivity. The electrophotographic photoreceptor is expected to contribute to speeding up and high performance of various image forming apparatuses. It can also be used for liquid development.
Since the diamine derivative of the present invention has a high hole transport ability, it can be used for solar cells, electroluminescence devices, and the like.

1 is a schematic cross-sectional view showing an example of a single-layer electrophotographic photoreceptor. It is a schematic sectional drawing which shows the other example of the photoreceptor for single layer type electrophotography. It is a schematic sectional drawing which shows the other example of the photoreceptor for single layer type electrophotography. It is a schematic sectional drawing which shows an example of a laminated type electrophotographic photoreceptor. It is a schematic sectional drawing which shows the other example of a laminated type electrophotographic photoreceptor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Single layer type electrophotographic photoreceptor (electrophotographic photoreceptor) 12 Conductive substrate 14 Photoreceptor layer 20 Laminated electrophotographic photoreceptor (electrophotographic photoreceptor) 22 Charge transport layer (photoreceptor layer) 24 Charge Generation layer (photoreceptor layer)

Claims (2)

The diamine derivative which is a compound represented by following formula (1).

In formula (1), Ar ¹ has a divalent group generated by removing one hydrogen atom from an alkyl group which may have one or more substituents, and one or more substituents. A divalent group generated by removing one hydrogen atom from the aryl group which may be present, or a heterocyclic group optionally having one or more substituents, Ar ^2a and Ar ^2b are each An aryl group optionally having one or more substituents or a heterocyclic group optionally having one or more substituents, wherein R ^{1a to} R ^12a and R ^{1b to} R ^12b are each hydrogen; Atom, halogen atom, alkyl group optionally having one or more substituents, aryl group optionally having one or more substituents, optionally having one or more substituents May have an alkoxy group or one or more substituents An aralkyl ^group, R 13a ^{to R 16a} and ^R 13b ^{to R 16b} are each a hydrogen atom, one or more substituents alkyl group that may have a may have one or more substituents An aryl group, an alkoxy group optionally having one or more substituents, or an aralkyl group optionally having one or more substituents, and m and n are each an integer of 0 or more. However, Ar <^2a> , Ar ^<2b> , R < ^1a > -R < ^16a > and R ^<1b > -R <^16b> are respectively the same or different. A conductive substrate;
A photoreceptor layer provided on the conductive substrate,
An electrophotographic photoreceptor, wherein the photoreceptor layer is a layer containing the diamine derivative according to claim 1.

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