JP4996076B2 - Novel triphenylene compound and method for producing the same - Google Patents

Description

  The present invention relates to an organic photoconductor, and more particularly to a triphenylene compound useful as a photoreceptor having high-speed response and high stability, and a method for producing the same.

  In recent years, there has been a remarkable development in information processing system machines using electrophotography. In particular, laser printers and digital copying machines that convert information into digital signals and record information using light have significantly improved print quality and reliability. Furthermore, they have been applied to laser printers or digital copiers capable of full-color printing by fusing with high-speed technology.

  As photoconductors used in these electrophotographic laser printers and digital copying machines, those using organic photosensitive materials (OPC) are generally widely used for reasons such as cost, productivity and pollution-free. Applied. The layer structure of the OPC photoreceptor is roughly divided into a single layer type and a function separation type laminated structure. The first practical OPC, the PVK-TNF charge transfer complex type photoreceptor, was the former single layer type.

  On the other hand, in 1968, Hayashi and Regensburger independently invented PVK / a-Se laminated photoreceptors, and later in 1977 by Melz et al. And in 1978 Schlosser called organic pigment dispersion layers and organic low molecular weight dispersion polymer layers. A multi-layer photoconductor in which all photosensitive layers are made of organic materials has been announced. These functions are separated from the concept of a charge generation layer (CGL) that absorbs light and generates charge, and a charge transport layer (CTL) that injects and transports the charge generated by CGL and neutralizes the surface charge. Also called a mold-laminated photoconductor.

  This development has dramatically improved sensitivity and durability compared to single-layer photoconductors. In addition, materials with different functions, called charge generation materials (CGM) and charge transport materials (CTM), can be designed individually, so the selection range of these materials has greatly increased.

  For these reasons, the function-separated laminated photoconductor has the mainstream layer structure of the current OPC photoconductor. The mechanism of electrostatic latent image formation in the function-separated type photoconductor is that when the photoconductor is charged and then irradiated with light, the light passes through the charge transport layer and is absorbed by the charge generation material in the charge generation layer to generate a charge. . Charges generated thereby are injected into the charge transport layer at the interface between the charge generation layer and the charge transport layer, and further moved through the charge transport layer by an electric field, thereby forming an electrostatic latent image by canceling the surface charge of the photoreceptor. Is.

  In recent years, due to the reduction in the diameter of the photosensitive member accompanying the increase in the speed of the electrophotographic apparatus or the downsizing of the apparatus, the high speed response and stability of the photosensitive member have become more important issues.

  Commercially available charge transport materials include 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene (see, for example, Patent Document 1), 5- [4- (N , N-di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene (see, for example, Patent Document 2), 9-methylcarbazole-3-aldehyde 1,1-diphenylhydrazone, pyrene-1-aldehyde 1,1-diphenylhydrazone (see, for example, Patent Document 3), 4′-bis (4-methylphenyl) amino-α-phenylstilbene, N, N′-diphenyl-N, N′-bis (3-methylphenyl) )-[1,1′-biphenyl] -4,4′-diamine, 9,9-dimethyl-2- (di-p-tolylamino) fluorene and the like have been proposed.

  A general charge transport layer is a solid solution film of about 10 to 30 μm in which these low molecular charge transport materials are molecularly dispersed in a binder resin. As the binder resin, bisphenol-based polycarbonate resin, polyarylate resin, or a copolymer of these with other resins is used in most electrophotographic photoreceptors. However, these charge transport materials are not responsive enough to accommodate future faster process speeds.

On the other hand, molecular design guidelines regarding high-speed response (high mobility) of these charge transport materials are shown (for example, see Non-Patent Document 1). That is, a phenylamine group (> N-phenyl) is used as a sensitive group, and there is a clear correlation between this number and mobility, and it is stated that the higher the number of sensitive groups in the molecule, the higher the mobility. Based on this, the compound of the present application has a multi-sensitive group, thereby realizing high-speed response.
JP 62-30255 A JP-A-63-225660 JP 58-159536 A Journal of Electrophotographic Society, 25 (3), 16 (1986)

  The present invention has been made in consideration of the above-described circumstances, and triphenylene useful as an organic photoconductor for obtaining a photoconductor having high-speed response and high stability in order to cope with future high-speed electrophotography. It aims at providing a compound and a manufacturing method.

  In order to solve the above problems, the invention described in claim 1 is characterized by a triphenylene compound represented by the following general formula (1).

(Wherein R ₁ and R ₂ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different. R ₁ and R ₂ are bonded to each other. R ₃ may be a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group containing a nitrogen atom. A hydrocarbon group and a halogen atom are represented, and n represents an integer of 1 to 4.)

  The invention according to claim 2 is the above general formula in which 2,3,6,7,10,11-hexabromotriphenylene of the following general formula (2) is reacted with a boron compound of the following general formula (3). The method for producing a triphenylene compound according to (1) is characterized.

(Wherein R ₁ , R ₂ , R ₃ and n are the same as above)
Further, the invention according to claim 3 is a method of reacting the 2,3,6,7,10,11-hexabromotriphenylene of the general formula (2) with a boron compound of the following general formula (4). It is characterized by a method for producing a triphenylene compound of formula (1).

(Wherein R ₁ , R ₂ , R ₃ and n are the same as above)

  According to the present invention, the triphenylene compound represented by the general formula (1) according to the present invention is novel and functions effectively as a photoconductive material as described above, and the charge of the photosensitive layer of the electrophotographic photoreceptor. As a charge transport material in a so-called function-separated photosensitive layer, which is preferably used as a transport material, etc., in particular, a charge generation layer and a charge transport layer are divided into two layers, high-speed response and stability that can cope with high-speed electrophotography It is possible to obtain a photoconductor having a high thickness.

  Further, these novel triphenylene compounds can be produced by the production method of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
According to the present invention, the general formula _{(1) (R 1, R} 2 is a substituted or unsubstituted alkyl group, an aromatic hydrocarbon group, may be the same or different. Also, R _1, R ₂ may be bonded to each other to form a substituted or unsubstituted heterocyclic group containing a nitrogen atom, and R ₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted group. A substituted aromatic hydrocarbon group and a halogen atom, and n represents an integer of 1 to 4, and a triphenylene compound represented by the above-mentioned (2) 2, 3, 6, 7, 10 , 11-hexabromotriphenylene is reacted with the boron compound of (3) or (4) above, to provide a method for producing the triphenylene compound of the above formula (1). In formulas (3) and (4), R ₁ , R ₂ , R ₃ and n are the same as described above.

  As described above, the triphenylene compound represented by (1) of the present invention is a novel compound and the corresponding 2,3,6,7,10,11-hexabromotriphenylene represented by (2) above, It can be produced by reacting the boron compound represented by (3) or (4) above.

  In order to produce them, a mixture of the general formula (2) and the general formula (3) or the raw material of the general formula (4) or a salt thereof with metal palladium in the presence or absence of a base, 100 to 250 It can manufacture by attaching | subjecting to the coupling reaction made to react at the temperature of about a degree.

  The solvent used in this reaction is not particularly limited as long as it does not adversely influence the reaction. For example, water; alcohols such as methanol, ethanol and propanol; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as methylene chloride, chloroform and dichloroethane; halogenated aromatic carbon such as dichlorobenzene Hydrogens; ethers such as dioxane, tetrahydrofuran, and anisole; esters such as ethyl acetate and butyl acetate; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile; N, N-dimethylformamide and N, N-dimethyl Examples include amides such as acetamide; sulfoxides such as dimethyl sulfoxide, and these solvents may be used in combination.

  Examples of basic substances include potassium acetate, potassium carbonate, sodium bicarbonate, sodium carbonate, triethylamine and the like. The amount of use is specifically 1 to 3 moles. Examples of the metal palladium include inorganic palladium salts such as palladium chloride; organic palladium salts such as palladium acetate; tetrakis (triphenylphosphine) palladium (0), bis (triphenylphosphine) palladium (II) chloride, 1,1′- And organic palladium complexes such as bis (diphenylphosphino) ferrocenepalladium (II) dichloride. Specifically, the amount used is 0.001 to 0.5 times mol.

  Specific examples of the alkyl group in the description of the general formula include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and an undecanyl group. In addition, aromatic hydrocarbon groups include aromatic rings such as benzene, biphenyl, naphthalene, anthracene, fluorene and pyrene, and aromatic heterocyclic groups such as pyridine, quinoline, thiophene, furan, oxazole, oxadiazole and carbazole. Can be mentioned.

These substituents include those exemplified in the above specific examples of alkyl groups, alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group, or halogen atoms of fluorine atom, chlorine atom, bromine atom and iodine atom. Atoms, the aromatic hydrocarbon groups, and heterocyclic groups such as pyrrolidine, piperidine, piperazine and the like can be mentioned. Further, when R ₁ and R ₂ are bonded to each other to form a heterocyclic group containing a nitrogen atom, the heterocyclic group is a condensed heterocyclic ring in which an aromatic hydrocarbon group is condensed with a pyrrolidino group, piperidino group, piperazino group or the like. The group can be mentioned.

  The novel triphenylene compound represented by (1) of the present invention is extremely useful as a photoconductive material in electrophotographic photoreceptors. Further, this is particularly useful as a charge transport material in a so-called function-separated type photoreceptor using an organic pigment or an inorganic pigment as a charge generation material.

  The starting material 2,3,6,7,10,11-hexabromotriphenylene can be synthesized in high yield by hexabromination of triphenylene by the method described in Tetrahedron. 38.863 (1982).

  Examples of organic pigments include CI Pigment Blue 25 (Color Index CI 21180), CI Pigment Red 41 (CI 21200), CI Acid Red 52 (CI 45100), CI Basic Red 3 (CI 45210), and azo pigments having a carbazole skeleton ( JP-A-53-95033), azo pigments having a distyrylbenzene skeleton (described in JP-A-53-133445), azo pigments having a triphenylamine skeleton (JP-A-53-132347) Azo pigments having a dibenzothiophene skeleton (described in JP-A No. 54-21728), azo pigments having an oxadiazole skeleton (described in JP-A No. 54-12742), azo pigments having a fluorenone skeleton Pigment (described in JP-A-54-22834), azo pigment having a bis-stilbene skeleton (Described in JP-A No. 54-17733), azo pigments having a distyryl oxadiazole skeleton (described in JP-A No. 54-2129), azo pigments having a distyryl carbazole skeleton (Japanese Unexamined Patent Publication No. 54-129) 14967), and azo pigments such as azo pigments having a benzanthrone skeleton. For example, CI Pigment Blue 16 (CI 74100), Y-type oxotitanium phthalocyanine (described in JP-A No. 64-17066), A (β) -type oxotitanium phthalocyanine, B (α) -type oxotitanium phthalocyanine, I-type oxo Titanium phthalocyanine (described in JP-A-11-21466), type II chlorogallium phthalocyanine (Iijima et al., Chemical Society of Japan 67th Spring Annual, 1B4, 04 (1994)), type V hydroxygallium phthalocyanine (Damon et al., Japan) Chemical Society 67th Spring Annual, 1B4, 05 (1994)), phthalocyanine pigments such as X-type metal-free phthalocyanine (described in US Pat. No. 3,816,118), C-Ibat Brown 5 (CI 73410), C-I Indigo pigments such as Bat Die (CI 73030), Argo Scarlet B (Bayer) ), Such as perylene pigment, such as in-closet Ren Scarlet R (manufactured by Bayer Co., Ltd.) and the like. These materials may be used alone or in combination of two or more. In addition, inorganic pigments such as selenium, selenium-tellurium, cadmium sulfide, and α-silicon can also be used.

Hereinafter, the present invention will be described in detail with reference to examples.
[Example 1]
Production of 2,3,6,7,10,11-hexabromotriphenylene This is produced by the reaction shown in the following reaction formula (5).

  Triphenylene: 1.00 g (4.38 mmol) and Fe: 90 mg were dissolved in nitrobenzene: 20 ml and stirred, bromine: 3.15 g (39.42 mmol) was added dropwise, the mixture was stirred at room temperature for 3 hours, and further heated to 205 ° C. And stirred for 3 hours. After cooling, 50 ml of ether was added and the precipitated crystals were filtered off, washed with ether and acetone, and 2,0,3,6,7,10,11-hexabromotriphenylene (1): 3.00 g (yield 97. 6%).

[Example 2]
Manufacture of a boron compound It manufactures by reaction shown to following Reaction formula (6).

  Bromo compound (2) in reaction formula (6): terahydrofuran (dehydrated): 200 ml was added to 20 g (44 mmol), cooled to −70 ° C., and n-butyllithium (1.6 M) dissolved in n-hexane. ): 42 ml was added and stirred for 2 hours. Thereafter, 13.72 g of trimethoxyborane (132 mmol) was gradually added dropwise and stirred for 6 hours. After standing at room temperature, water was added, extracted with toluene, and washed with water. The organic layer was concentrated under reduced pressure, and the resulting dark yellow oily substance was subjected to silica gel column treatment [eluent: toluene / dichloromethane (1/1) vol] to give a yellow amorphous boron compound (3): 18.20 g (98 .6%).

[Example 3]
Manufacture of a triphenylene compound It manufactures by reaction shown in following Reaction formula (7).

Hexabromotriphenylene (1) in reaction formula (7): 0.3 g (0.427 mmol), boron compound (3): 1.611 g (3.843 mmol), K ₂ CO ₃ : 0.796 g, tetrakis (triphenyl) Phosphine) palladium (0): 1.332 g (1.234 mmol), DMF: 10 ml, H 2 O: 5 ml, o-dichlorobenzene: 40 ml were mixed and stirred at 125 ° C. for 7 hours. After cooling to room temperature, water was added, extracted with toluene, and washed with water. The dark yellow oily substance obtained by concentrating the organic layer under reduced pressure was subjected to silica gel column treatment [eluent: MDC / n-hexane (1/2) vol] to obtain yellow amorphous crystals represented by the following chemical formula (8). 0.96 g (yield 91.0%) of the triphenylene compound in the reaction formula was obtained.

  The elemental analysis value is shown in the following table as C150H126N6.

  The infrared absorption spectrum (KBr tablet method) of this compound (8) is shown in FIG.

[Example 4]
Manufacture of a triphenylene compound It manufactures by reaction shown in following Reaction formula (9).

Hexabromotriphenylene (1) in reaction formula (9): 0.2 g (0.0285 mmol), boron compound (5): 1.28 g (2.565 mmol), saturated NaHCO ₃ : 10 ml, 1,1′-bis ( Diphenylphosphino) ferrocenepalladium (II) dichloride: 0.187 g (0.2565 mmol) and THF: 20 ml were mixed and stirred at 100 ° C. for 7 hours. After cooling to room temperature, water was added, extracted with dichloromethane, and washed with water. The dark yellow oil obtained by concentrating the organic layer under reduced pressure was subjected to silica gel column treatment [eluent: MDC / n-hexane (1/2) vol] to obtain yellow amorphous crystals represented by the above formula (8). 0.63 g (yield 89.9%) of a triphenylene compound was obtained.

[Application example]
In a ball mill, 2.5 parts by weight of a fluorenone-based bisazo pigment represented by the following formula (10), 2.5 parts by weight of a polyester resin [Byron 200 manufactured by Toyobo Co., Ltd.], and 495 parts by weight of a tetrahydrofuran solution are used as a charge generating substance. After pulverizing and mixing, the resulting dispersion was applied onto an aluminum vapor-deposited polyester film with a doctor blade and naturally dried to form a charge generation layer of about 0.5 μm.

Next, 1 part of a triphenylene compound represented by the above formula (8) is dissolved as a charge transport material in a resin solution of 1 part of a polycarbonate resin [Panlite K-1300 manufactured by Teijin Ltd.] and 8 parts of tetrahydrofuran. The solution was applied onto the charge transport layer with a doctor blade, dried at 80 ° C. for 2 min, and then dried at 120 ° C. for 5 min to form a charge transport layer having a thickness of about 20 μm to prepare a photoreceptor.
Next, in order to investigate the transit time indicating the response characteristics of the multilayer electrophotographic photosensitive member thus obtained, an electrostatic copying paper test apparatus (type EPA8100 manufactured by Kawaguchi Electric Manufacturing Co., Ltd.) was used for this photosensitive member. The exposure amount that can be light-attenuated from −800 V to −100 V after 1 s with an exposure time of 33 ms is determined, and the value obtained by subtracting the exposure time of 33 ms from the time of reaching −150 V is defined as the transit time (tr). I did it. The result was tr = 8 ms.

[Comparative example]
When the photoconductor was prepared and the tr measurement was carried out for the amine compound represented by the following formula (11) represented by the following structural formula in the same manner as in the application example, tr = 22 ms.

It is an infrared absorption spectrum figure of the triphenylene compound of the present invention.

Claims (3)

A triphenylene compound represented by the following general formula (1).

(Wherein R ₁ and R ₂ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different. R ₁ and R ₂ are bonded to each other. R ₃ may be a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group containing a nitrogen atom. A hydrocarbon group and a halogen atom are represented, and n represents an integer of 1 to 4.) Reacting 2,3,6,7,10,11-hexabromotriphenylene of the following general formula (2) with a boron compound of the following general formula (3) to produce a triphenylene compound of the following general formula (1) A process for producing a triphenylene compound characterized by the above .

(In the formulas (1) and (3), R ₁ and R ₂ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different. R ₁ and R ₂ may be bonded to each other to form a substituted or unsubstituted heterocyclic group containing a nitrogen atom, and R ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group. Represents a substituted or unsubstituted aromatic hydrocarbon group or a halogen atom, and n represents an integer of 1 to 4.) Following general formula (2) of 2,3,6,7,10,11 hexa-bromo triphenylene and the following general formula (4) and the boron compound is reacted in to produce a triphenylene compound of the following general formula (1) A process for producing a triphenylene compound characterized by the above .

(In the formulas (1) and (4), R ₁ and R ₂ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different. R ₁ and R ₂ may be bonded to each other to form a substituted or unsubstituted heterocyclic group containing a nitrogen atom, and R ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group. Represents a substituted or unsubstituted aromatic hydrocarbon group or a halogen atom, and n represents an integer of 1 to 4.)

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