JPH11305464A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor excellent in photosensitivity, charge holding ability, mechanical characteristics and resolution by forming a photosensitive layer which consists of a phthalocyanine-based photoconductive material and a liquid crystal polymer having charge transfer ability based on the hopping conduction mechanism with a specified range of the weight ratio of these materials. SOLUTION: This photoreceptor has a photosensitive layer comprising a phthalocyanine-based photoconductive material (A) and a liquid crystal polymer (B) having charge transfer ability based on the hopping conduction mechanism with weight ratio of (A):(B)=1:2 to 1:100. The phthalocyanine-based photoconductive material (A) is preferably a nonmetal phthalocyanine showing diffraction peaks at least at 7.4 deg., 9.0 deg., 16.5 deg., 17.2 deg., 22.1 deg., 23.8 deg., 27.0 deg. and 28.4 deg. Bragg angle for CuKα X-ray, each having -0.2 deg. to +0.2 deg. allowance. The liquid crystal polymer (B) is preferably a liquid crystal polymer having disk-like or rodlike mesogenic groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of manufacturing and using an electrophotographic photosensitive member used in, for example, an electrophotographic copying machine or printer.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor using an inorganic photoconductive material such as selenium, cadmium sulfide, zinc oxide or amorphous silicon has been used. , These materials are highly toxic,
There are problems such as low moisture resistance and high manufacturing cost. On the other hand, an organic photoconductor using an organic photoconductive material instead of an inorganic photoconductive material can easily select a non-polluting material, has a low manufacturing cost, and has other characteristics. In terms of surface, high sensitivity and high printing durability can be obtained, so that they have been widely used instead of inorganic photoreceptors.

[0003] Many of the organic photoreceptors that have been put into practical use are:
In order to achieve high sensitivity, it is manufactured by laminating, on an aluminum support, at least a charge generation layer that absorbs light to generate carriers and a charge transport layer that moves generated carriers. As the charge generation material used for the charge generation layer of the laminated organic photoreceptor,
Organic materials such as perylene compounds, phthalocyanine compounds, azo compounds, and quinacridone compounds have been studied. Further, as the charge transporting material used for the charge transporting layer, a hydrazone-based compound, an oxazole-based compound,
Triphenylmethane compounds, arylamine compounds, triphenylamine compounds and the like have been studied.

However, since the stacked organic photoreceptor is of a negative charging type, oxygen in the air is converted into ozone by corona discharge, and there is a fear that the ozone may affect the human body. Further, the negative charging method has disadvantages such as lack of charging stability, which leads to deterioration of image quality and is not preferable.

[0005] In order to solve the above-mentioned drawbacks of the laminated organic photoreceptor, various researches and developments have been carried out, for example, Japanese Patent Application Laid-Open Nos. 53-64040 and 53-640.
JP-A-83744 and JP-A-60-256146 propose a photoreceptor using a phthalocyanine-based compound. It uses a photosensitive material in which a phthalocyanine-based compound is dispersed in a polyester resin or a polycarbonate resin, and is a positively charged type that generates less ozone.
Further, since it is excellent in light sensitivity, there is a feature that it is not necessary to stack as in the case of the negative charging method.

An organic photoreceptor using this phthalocyanine-based compound is usually prepared by dispersing phthalocyanine-based compound particles in a binder resin on an aluminum drum provided with an undercoat layer or on an alumite-treated aluminum drum. It has a configuration in which a layer is provided. As the binder, a polyester-melamine-based resin as described in JP-A-1-169454 is used. This resin is a resin selected so as to satisfy the electrical characteristics of the photoreceptor and the initial electrophotographic characteristics.

When a phthalocyanine-based compound is used as a non-laminated type electrophotographic photoreceptor material, for example, US Pat. No. 3,816,118 and Japanese Patent Publication No.
As shown in 4338 gazette and the like, having large absorbance characteristics, excellent heat resistance, chemical resistance and light resistance,
Furthermore, it has a feature that it has high photoconductivity by light irradiation, that is, it has excellent generation efficiency of electron-hole pairs.

[0008]

As described above, although the organic photoreceptor for electrophotography has been put to practical use, the printing speed is low due to the lower charge mobility as compared with the inorganic photoreceptor, and therefore the printing speed is low. Is insufficient in high-speed response, and improvement is desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the problem of high-speed response of an organic photoreceptor, and has been made to provide an electrophotographic photoreceptor excellent in photosensitivity, charge retention ability, mechanical properties and resolution. The purpose is to gain the body.

[0010]

According to a first aspect of the present invention, there is provided an electrophotographic photoreceptor comprising a phthalocyanine-based photoconductive material (A) and a liquid crystal polymer (B) having a charge transporting ability based on a hopping conduction mechanism. (A): (B) = 1: 2-1: 1:
It has 100 (weight ratio) photosensitive layers.

According to a second aspect of the present invention, there is provided the electrophotographic photosensitive member according to the first aspect, wherein the phthalocyanine-based photoconductive material (A) is used.
However, the Bragg angle of the diffraction peak with respect to the X-ray of CuKα is at least 7.4 °, 9.0 °, 16.5 °, 17.2
Degrees, 22.1 degrees, 23.8 degrees, 27.0 degrees and 28.
At 4 degrees, and in each case from -0.2 degrees to +0.
It is a metal-free phthalocyanine with a tolerance of up to 2 degrees.

According to a third aspect of the present invention, in the electrophotographic photosensitive member according to the first aspect, the liquid crystal polymer (B) is a liquid crystal polymer having a disk-shaped or rod-shaped mesogen group.

According to a fourth aspect of the present invention, there is provided the electrophotographic photoreceptor according to the third aspect, wherein the disk-shaped mesogen group has a triphenylene skeleton.

According to a fifth aspect of the present invention, in the third aspect, the rod-shaped mesogen group has a phenylbenzothiazole skeleton.

According to a sixth aspect of the present invention, in the electrophotographic photosensitive member according to the third aspect, the rod-shaped mesogen group has a naphthalene skeleton.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The phthalocyanine-based photoconductive material (A) used in the present invention includes, for example, aluminum phthalocyanine, aluminum polychlorophthalocyanine, antimony phthalocyanine, barium phthalocyanine, beryllium phthalocyanine, cadmium phthalocyanine, cadmium hexadecachlorophthalocyanine. ,
Calcium phthalocyanine, cerium phthalocyanine,
Chrome phthalocyanine, cobalt phthalocyanine, cobalt chlorophthalocyanine, copper 4-bromochlorophthalocyanine, copper 4-aminophthalocyanine, copper bromochlorophthalocyanine, copper 4-chlorophthalocyanine, copper 4-nitrophthalocyanine, copper sulfonate phthalocyanine, copper polychlorophthalocyanine, Deuteriophthalocyanine, dysbrosium phthalocyanine, erbium phthalocyanine, eurobium phthalocyanine, gadolinium phthalocyanine, gallium phthalocyanine, germanium phthalocyanine, hafnium phthalocyanine,
Halogen-substituted phthalocyanine, polymium phthalocyanine, indium phthalocyanine, iron phthalocyanine, iron polyhalophthalocyanine, lanthanum phthalocyanine, lead phthalocyanine, lead polychlorophthalocyanine, cobalt hexaphenylphthalocyanine, copper pentaphenylphthalocyanine, lithium phthalocyanine, ruthenium phthalocyanine, magnesium phthalocyanine, magnesium phthalocyanine, manganese Phthalocyanine, mercury phthalocyanine, molybdenum phthalocyanine, nickel polyhalophthalocyanine, osmium phthalocyanine, palladium phthalocyanine, palladium chlorophthalocyanine, alkoxyphthalocyanine, alkylaminophthalocyanine, alkylmercaptophthalocyanine, aralkylaminophthalocyanine,
Allyloxyphthalocyanine, allylmercaptophthalocyanine, copper phthalocyanine, piperidine phthalocyanine, cycloalkylaminophthalocyanine, dialkylaminophthalocyanine, alkylaminophthalocyanine, dicycloalkylaminophthalocyanine, hexadecahydrophthalocyanine, imidomethylphthalocyanine, 1,2-naphthalocyanine, 2, , 3-Naphthalocyanine, octazanaphthalocyanine, sulfaphthalocyanine, tetraazaphthalocyanine, tetra-4-acetylaminophthalocyanine, tetra-4-aminobenzoylphthalocyanine, tetra-4-aminophthalocyanine, tetrachloromethylphthalocyanine, tetradiazophthalocyanine, tetra -4,4-dimethyloctazaphthalocyanine, tetra 4,5-diphenyloctazaazaphthalocyanine, tetra- (6-methyl-benzothiazoyl) phthalocyanine, tetra-p-methylphenylaminophthalocyanine, tetra-methylphthalocyanine, tetra-naphthotriazolyl phthalocyanine, tetra-4-naphthyl phthalocyanine , Tetra-4-nitrophthalocyanine, tetra-peri-naphthylene-4,5-
Octa-azaphthalocyanine, tetra-2,3-phenylene oxide phthalocyanine, tetra-4-phenyloctazaazaphthalocyanine, tetraphenylphthalocyanine tetracarboxylic acid, tetraphenylphthalocyanine tetrabarium carboxylate, tetraphenylphthalocyanine tetrabarium carboxylate, tetraphenylphthalocyanine Tetra-calcium carboxylate, tetrapyridiphthalocyanine, tetra-4-
Trifluoro-methylmercaptophthalocyanine, tetra-4-trifluoromethylphthalocyanine, 4,5-thionaphthaline-octaazophthalocyanine, platinum phthalocyanine, potassium phthalocyanine, rhodium phthalocyanine, samarium phthalocyanine, silver phthalocyanine,
Silicone phthalocyanine, sodium phthalocyanine, sulfated phthalocyanine, thorium phthalocyanine,
Thulium phthalocyanine, tin phthalocyanine, tin chlorophthalo-phthalocyanine, titanyl phthalocyanine, hydroxygallium phthalocyanine, metal-free phthalocyanine, and the like, together with or instead of these phthalocyanines, any suitable mixture of phthalocyanines, dimers, trimers, etc. Examples include monomers, oligomers, polymers, copolymers, and mixtures thereof.

Above all, a metal-free phthalocyanine is preferable, and the Bragg angle of the X-ray diffraction peak with respect to the CuKα X-ray as shown in FIG.
9.0 degrees, 16.5 degrees, 17.2 degrees, 22.1 degrees, 2
Metal-free phthalocyanine at 3.8 degrees, 27.0 degrees and 28.4 degrees, each having a tolerance of -0.2 degrees to +0.2 degrees, or X-type, τ-type, α
And non-metallic phthalocyanines such as β-type.
Among them, the Bragg angle of the X-ray diffraction peak with respect to the X-ray of CuKα as shown in FIG.
4 degrees, 9.0 degrees, 16.5 degrees, 17.2 degrees, 22.1
More preferred are metal-free phthalocyanines which have an allowable range of -0.2 degrees to +0.2 degrees, each at 23.8 degrees, 27.0 degrees and 28.4 degrees.

The X-ray diffraction spectrum shown in FIG. 1 was obtained from Rigaku RINT1200 X-ray Diffract.
It was measured at a tube voltage of 50 kV and a tube current of 30 mA using an ometer.

The metal-free phthalocyanine-based photoconductive material (A) may include a charge generation material such as a perylene-based compound, an azo-based compound, and a quinacridone-based compound.

The liquid crystal polymer (B) used in the present invention is a polymer having charge transport ability based on a hopping conduction mechanism and exhibiting liquid crystallinity. Since the charge mobility is relatively high due to the charge transport ability based on the hopping conduction mechanism, the high-speed response is excellent. Further, hopping sites are regularly arranged to exhibit liquid crystal properties, and carriers can be moved at higher speed, so that an electrophotographic photosensitive member having excellent photoresponsiveness can be provided.

Having the charge transporting ability based on the hopping conduction mechanism means that even if there is no chemical bond between the sites where the conductive carriers flow, there is a spatial overlap of the wave functions of the electrons present at the respective sites, and the conductive carriers of the conductive carriers flow. The exchange is performed. Whether or not it has this charge transporting ability can be evaluated by measuring the temperature dependence of the charge mobility.

The above-mentioned liquid crystal property means that a material may have a magnetic field, an electric field, heat,
By applying an external force such as light or mechanical action, molecules are arranged in the direction of the external force to form an ordered structure and exhibit optical anisotropy. As the liquid crystal properties, a lyotropic liquid crystal exhibiting liquid crystallinity in a solvent and a thermotropic liquid crystal exhibiting liquid crystallinity in a molten state are known. However, in the present invention, it is easy to form a photosensitive layer on a substrate. Therefore, a thermotropic liquid crystal polymer is preferable. Whether or not this liquid crystal property is exhibited can be evaluated by observing optical anisotropy.

The liquid crystal phase represented by the liquid crystal polymer includes a nematic phase and a smectic phase (SA, SC, SB, S
I, SH, etc.), discotic phase (column phase) (N
D, Dh, Dr, Dob, etc.). The liquid crystal phase of the liquid crystal polymer (B) used in the present invention is not particularly limited as long as it has a liquid crystal structure in which the charge transport site is oriented so as to facilitate hopping conduction. In the case, the Dh phase is preferable, and in the case of the smectic liquid crystal having a rod-like mesogen group, the SA phase is preferable. The alignment of the liquid crystal polymer does not need to be aligned at the time of manufacturing, and may be completed when the photoconductor is used.

The liquid crystal polymer has a mesogen group having a rigid structure necessary for exhibiting liquid crystallinity. Depending on the position of the mesogen group, a mesogen group may be added to the main chain having a mesogen group in the main chain, a side chain having a mesogen group in the side chain, and a main chain having a mesogen group in the main chain. And the like. The liquid crystal polymer (B) used in the present invention has a charge transporting ability based on a hopping conduction mechanism and has liquid crystallinity.
Any of a main chain type, a side chain type, and a complex type can be used.

The main chain type liquid crystal polymer is composed of a unit having a mesogen group in the main chain, a unit forming a bent chain, which is included as necessary, and a unit forming a bonding group having no bent chain.

The unit having a mesogen group in the main chain is
Depending on the shape of the molecule of the mesogen group, a unit having a disk-shaped mesogen group or a unit having a rod-shaped mesogen group exists.

The disk-shaped mesogen group is a group in which a portion consisting of a plate-like molecule and a bent chain forms a two-dimensional disk-like (so-called disk-like) structure. As a specific example, for example, as a neutral molecule not containing a hetero atom,
Benzene, naphthalene, anthracene, naphthacene, pentacene, phenanthrene, pyrene, chrysene, triphenylene, perylene, coronene, fluorancene, and the like containing a hetero atom include acridine, phenothiazine, phthalocyanine, porphyrin, and the like as a skeleton. And those having a charge transporting ability. Among them, those having a triphenylene skeleton are preferable because they have excellent hole transporting ability and can further improve the photosensitivity of the electrophotographic photoreceptor.

The rod-shaped mesogen group is a mesogen group in which a rigid portion is formed in a one-dimensional rod shape. Specific examples include those having a skeleton of naphthalene, anthracene, phenylbenzothiazole, carbazole, or the like. Among these, those having a phenylbenzothiazole skeleton are preferable because they have excellent hole transporting ability and can further improve the photosensitivity of the electrophotographic photoreceptor, and those having a naphthalene skeleton have an electron and hole transporting ability. Can be combined
It is preferable because the photosensitivity of the electrophotographic photosensitive member can be further improved.

The unit forming the bent chain includes, for example, an alkyl unit, an alkoxy unit, and a polysiloxane unit each having an appropriate length for exhibiting liquid crystallinity.

The binding group having no bent chain includes, for example, an ester group, a urethane group, an amide group, an ether group and the like.

The side chain type liquid crystal polymer includes a unit having a mesogen group in the side chain, a unit having no mesogen group forming the side chain, a skeleton chain unit having no mesogen group in the main chain, and if necessary. A unit forming a bent chain that binds a unit having a mesogen group, and a unit forming a binding group that has no flexibility (W. Kreuder and H. Ringsdorf, Makromol.
Chem., Rapid Commun. 4, 807 (1983)).

The unit having a mesogen group in the side chain is
It is the same as the main chain type, and depending on the molecular shape of the mesogen group, there is a disk-shaped or rod-shaped mesogen group.

The unit having no mesogen group forming the side chain includes, for example, an alkyl unit or an alkoxy unit having an appropriate length for arranging hopping sites.
And polysiloxane units.

Examples of the skeleton chain unit having no mesogen group in the main chain include a skeleton chain unit whose main chain forms poly (meth) acrylate, a skeleton chain unit whose main chain forms polysiloxane, A skeleton chain unit in which the main chain forms a polyester, a skeleton chain unit in which the main chain forms a polyether, a skeleton chain unit in which the main chain forms a polythioether, and a main chain forming a polyolefin Examples include a skeleton chain unit, a skeleton chain unit whose main chain forms polychloroacrylate, and a skeleton chain unit whose main chain forms polycyanoacrylate.

As the unit forming the bent chain and the binding group having no flexibility included in the above-mentioned optional structure, those having the same structure as that in the main chain type are used.

In order for the liquid crystal polymer to have charge transporting ability by hopping conduction, the following is preferable.

That is, as the liquid crystal polymer (B), a liquid crystal having a disk-shaped or rod-shaped mesogen group is preferably used. Hole transport, electron transport, and hole / electron transport are conceivable for hopping conduction.When used as a hole transport agent, triphenylene-based or phthalocyanine derivatives with a low ionization potential with stable cation radicals are used as skeletons. When the liquid crystal polymer is used as an electron transport agent, the liquid crystal polymer having a skeleton of a high electron affinity trinitrofluorenone or diphenoquinone derivative in which anion radicals are stably present. When used as a transport agent, a liquid crystal polymer having a skeleton of a neutral molecule containing no hetero atom such as benzene, naphthalene, anthracene or the like is preferable. For example, the following may be used as the hole transport agent. As a liquid crystal polymer having a disk-shaped mesogen group,

[0038]

Embedded image

Wherein R is OC _m H _{2m + 1} , a phenyl group,
SC _m H _{2m + 1} (m is each 3 to 21), and each R may be the same or different, and n is 3 to 21)

[0040]

Embedded image

(Wherein, R and n are the same as in the general formula (1))

[0042]

Embedded image

(Wherein R and n are the same as those in the above-mentioned general formula (1)) As the liquid crystal polymer having a rod-shaped mesogen group,

[0044]

Embedded image

(Where X is C _m H _{2m + 1} (n = 3 to ₂ )
1), n is 3 to 21, m + n> 10)

[0046]

Embedded image

(Where X, n, and m + n are the same as those in the general formula (4))

[0048]

Embedded image

Wherein X, n, and m + n are the same as those in the general formula (4), and have a phenylbenzothiazole structure;

[0050]

Embedded image

(Where m is 3-21, n is 3-21, m
+ N> 10)

[0052]

Embedded image

(Where m, n, and m + n are the same as those in the general formula (7))

[0054]

Embedded image

(Where m, n, and m + n are the same as those in the general formula (7)).

[0056]

Embedded image

And the like.

The polymer liquid crystal (B) may be used alone or in combination of two or more. Alternatively, two or more different types may be copolymerized and used.

The liquid crystal polymer (B) may be used in combination with a polymer compound that does not exhibit liquid crystallinity as long as the charge transport ability is not lost.

The liquid crystal polymer (B) may be used in combination with a low-molecular liquid crystal having a charge transporting ability by hopping conduction as long as the strength of the coating film is not reduced.

The liquid crystal polymer (B) may be used in combination with a charge transport agent. Specific examples of the charge transport agent include a hydrazone compound, an oxazole compound, a triphenylmethane compound, an arylamine compound,
And triphenylamine compounds.

The compounding ratio (weight ratio) of the phthalocyanine-based photoconductive material (A) and the liquid crystal polymer (B) having charge transport ability based on the hopping conduction mechanism is (A) :( B) =
1: 2 to 1: 100, preferably 1: 3 to 1: 8
0. When the compounding ratio is out of the above range, the electrophotographic characteristics during repeated use tend to deviate from the characteristics required for the electrophotographic photosensitive member.

An antioxidant may be added to the photosensitive layer of the present invention in order to prevent deterioration of the electrophotographic properties of the photosensitive member due to ozone generated during corona charging. Specific examples of the antioxidant include, for example, a silane coupling agent and a titanate coupling agent, N, N'-diphenyl-P-phenylenediamine (DPPD), 1,3,5-trimethyl-2,4,6- Tris (3,5-dibutyl-4-hydroxybenzyl) benzene, pentathrityl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), 1,6-hexanediol-
Bis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) triethylene glycol-
Bis (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate), 2,4-bis- (n
-Octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine,
2,2-thio-diethylenebis (3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate, N, N'-
Hexamethylene bis (3,5-di-t-butyl-4-hydroxyl-hydrocinnamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris- (3 , 5-Di-t-butyl-
4-hydroxybenzyl) -isocyanate, 2,4-
Compounds having a dialkylhydroxylphenyl group skeleton such as bis ((octylthio) methyl) -O-cresol are exemplified. These may be used alone or in combination of two or more.

The amount of the antioxidant added is preferably about 0.01 to 5.0% (% by weight, hereinafter the same) in the photosensitive layer.

An ozone-decomposable compound may be added to the photosensitive layer of the present invention in order to prevent deterioration of the electrophotographic characteristics of the photosensitive member due to ozone generated during corona charging. Specific examples of the ozonolysis compound include, for example, α-tocopherol, β-carotene, ascorbic acid, bis (dimethylaminophenyl) (aminomethyldithione) nickel, which is an active oxygen quencher. These may be used alone or in combination of two or more.

The amount of the ozonolytic compound added is preferably about 0.01 to 5.0% in the photosensitive layer.

The photosensitive layer according to the invention may contain an electron accepting substance as a sensitizer in order to improve the photosensitivity. Examples of the electron accepting substance that can be used as a sensitizer include tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ).

The composition for forming the photosensitive layer is usually prepared by mixing a metal-free phthalocyanine-based photoconductive material (A) and a liquid crystal polymer (B) in a solvent and dispersing the mixture with a paint shaker. And a dispersion using a disperser or the like.

The composition obtained by dispersing the thus obtained photoconductive material and liquid crystal polymer is immersed (dipping method) on the surface of a conductive support such as an aluminum drum provided with an undercoat layer. The photoreceptor of the present invention is formed by applying by a spray method or the like.

Examples of the method for aligning the liquid crystal polymer after coating include an annealing method, a rubbing method, a method using an electric field, a magnetic field, and the like.

As the conductive support, a conductor or an insulator subjected to a conductive treatment is used. Examples of such a support include metals or alloys such as Al, Ni, Fe, Cu and Au, and polyesters. Al, A on an insulating substrate such as polycarbonate, polyimide, glass, etc.
g, such as a metal or In ₂ O _2, the paper in which the conductive thin film formed ones or a conductive process material such as SnO _2, such as Au and the like. The shape of the conductive support is not particularly limited, and a drum-shaped, plate-shaped, belt-shaped, or the like may be used as needed.

The photoreceptor of the present invention is provided with an undercoat layer or an intermediate layer for the purpose of forming a barrier for stabilizing the electric characteristics and improving the adhesiveness as the mechanical characteristics. You may.

The photoreceptor may be provided with a protective layer on the photoreceptor layer in order to prevent the photoreceptor from being deteriorated by ozone generated by mechanical friction and charging in the development, transfer and cleaning steps. As the resin used for the protective layer,
Thermo- and photo-curable resins obtained by curing an acrylic resin, a polyester resin, a urethane resin, a butyral resin, a silicone resin, and an epoxy resin with an amino resin, an isocyanate resin, or the like are preferable.

Further, the antioxidant and the ozonolysis compound may be mixed with the resin used for the protective layer.

[0075]

EXAMPLES Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. The raw materials used in Examples and Comparative Examples are shown below.

Liquid crystal polymer 1: Chemical formula 1, m = 5, n = 3 Liquid crystal polymer 4: Chemical formula 4, m = 12, n = 7 Liquid crystal polymer 8: Chemical formula 8, m = 12, n = 8 Phthalocyanine: Bragg angles of 7.4, 9.0, 16.5, 17.2, 22.
Those that are 1, 23.8, 27.0 and 28.4 degrees.

Examples 1 to 6 and Comparative Examples 1 and 2 15 parts of a composition containing a liquid crystal polymer and a metal-free phthalocyanine in the proportions shown in Table 1 were added to 85 parts of toluene, and the mixture was mixed with a paint conditioner. Dispersed to obtain a solution.

An alumite tube (30 mmφ) was immersed in a container containing the above solution, and applied by dipping to a dry thin thickness of 20 μm. 25 ° C, 15-3
After air-drying for 0 minutes, annealing was performed at 100 ° C. for 1 hour to orient the polymer liquid crystal to obtain an electrophotographic photosensitive member. The obtained electrophotographic photoreceptor has a surface potential of 5 according to the following method.
The time required for the voltage to change from 00 V to 100 V and the printing result were evaluated. Table 1 shows the evaluation results.

(The time required for the surface potential to change from 500 V to 100 V)
After charging to 00 V and irradiating with a semiconductor laser (wavelength 780 nm, exposure energy: 1.5 μJ / cm ² ), the time required for the surface potential to change to 100 V was measured.

(Printing Result) The obtained photoreceptor was subjected to 30,000 cycles of charging and exposure using a corona charger and a semiconductor laser (780 nm).

：: good △: acceptable ×: unacceptable

[0082]

[Table 1]

A conventional organic photoreceptor has a surface potential of 500 V
The time required for the voltage to rise to 100 V is 100 ms or more. From the results in Table 1, it can be seen that the photoreceptor of the present invention has a response time of 30 ns or less and has a capability of coping with high-speed printing. The positional relationship between exposure and development is determined by the drum center angle 3
Assuming that the predetermined development potential is 100 V, the response time is 30 ms, and that sufficient exposure has been performed at 0 degree and 500 V charging, the drum diameter is 30 mmφ, 250 mm / sec, 84 m
Can handle process speeds of 500 mm / sec or more at mφ, and 70 sheets / m at 30 mmφ for A4 landscape printing
It is possible to print 140 sheets / min or more at 84 mmφ in.

The characteristics of the photoreceptors of Examples 1 to 6 hardly changed after 30,000 cycles of charging and exposure.

[0085]

According to the first aspect of the present invention, the phthalocyanine-based photoconductive material (A) and the liquid crystal polymer (B) having a charge transporting ability based on a hopping conduction mechanism, wherein (A) :( B) = When the ratio is 1: 2 to 1: 100 (weight ratio), the durability during repeated use can be improved while maintaining the electrophotographic characteristics required for the electrophotographic photosensitive member. Thereby, a stable image quality can be obtained even by continuous use.

In the second aspect of the present invention, the phthalocyanine-based photoconductive material (A) has a Bragg angle of a diffraction peak for CuKα X-rays of at least 7.4 degrees and 9.0 degrees.
Degrees, 16.5 degrees, 17.2 degrees, 22.1 degrees, 23.8 degrees
, 27.0 and 28.4 degrees, each having a permissible range from -0.2 to +0.2 degrees, thereby stabilizing the electrophotographic properties. In addition, durability during repeated use can be further improved.

According to the third aspect of the present invention, since the liquid crystal polymer (A) is a liquid crystal having a disk-like or rod-like mesogen group, it is possible to maintain the characteristics required for an electrophotographic photoreceptor while maintaining the characteristics. The sensitivity can be further improved.

According to the fourth aspect of the present invention, when the disk-shaped mesogen group has a triphenylene skeleton, the hole transport ability is improved, and the photosensitivity of the electrophotographic photoreceptor can be further improved.

According to the fifth aspect of the present invention, when the rod-shaped mesogen group has phenylbenzothiazole, the hole transport ability is improved, and the photosensitivity of the electrophotographic photoreceptor can be further improved.

According to the sixth aspect of the present invention, since the rod-shaped mesogen group has a naphthalene skeleton, the rod and the mesogen group can have both electron and hole transporting ability, thereby further improving the photosensitivity of the electrophotographic photosensitive member. be able to.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of a metal-free phthalocyanine.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takahiro Nishioka 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Takamitsu Fujimoto 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd.

Claims (6)

[Claims] 1. A phthalocyanine-based photoconductive material (A) and a liquid crystal polymer (B) having a charge transport ability based on a hopping conduction mechanism, wherein (A) :( B) = 1: 2
An electrophotographic photoreceptor having a photosensitive layer in a ratio of 1: 100 (weight ratio). 2. A phthalocyanine-based photoconductive material (A)
Has a Bragg angle of a diffraction peak with respect to X-rays of CuKα of at least 7.4 degrees, 9.0 degrees, 16.5 degrees, and 17.2 degrees.
Degrees, 22.1 degrees, 23.8 degrees, 27.0 degrees and 28.
At 4 degrees, and in each case from -0.2 degrees to +0.
2. The electrophotographic photoconductor according to claim 1, wherein the photoconductor is a metal-free phthalocyanine having an allowable range up to 2 degrees. 3. The electrophotographic photosensitive member according to claim 1, wherein the liquid crystal polymer (B) is a liquid crystal polymer having a mesogen group in a disk or rod shape. 4. The electrophotographic photoconductor according to claim 3, wherein the disk-shaped mesogen group has a triphenylene skeleton. 5. The electrophotographic photoreceptor according to claim 3, wherein the rod-shaped mesogen group has a phenylbenzothiazole skeleton. 6. The electrophotographic photoconductor according to claim 3, wherein the rod-shaped mesogen group has a naphthalene skeleton.