JP4696905B2 - Organic photoconductor for electrophotography and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic organic photoreceptor using a novel polymer charge transport material, and an electrophotographic image forming apparatus provided with the photoreceptor.

  Conventionally, electrophotographic image forming apparatuses using organic photoreceptors have been used in high-speed copying machines and printers. However, devices capable of outputting full color are rapidly becoming widespread, and further miniaturization and speeding up. Therefore, cost reduction and waste reduction are required. In order to enable high-speed output in a full-color image forming apparatus, a tandem system with charging, exposure, development, transfer, and static elimination devices for each of the three primary colors is advantageous. Since the above-described electrophotographic mechanism is mounted at least three or four including black, in order to reduce the size of the image forming apparatus main body, the mechanism itself is required to be smaller than before, and inevitably. In particular, the photoreceptor is in the direction of decreasing the diameter.

  By reducing the diameter of the photoreceptor, 1) processes such as charging, exposure, development, transfer, and charge removal necessary for forming one image are increased. 2) Even if the output speed, that is, the linear speed is constant, the angular speed increases in inverse proportion to the decrease in the photoreceptor diameter. 3) Since the interval between exposure-development and charge-removal-charging is limited due to the miniaturization of the mechanism, the photoconductor surface potential photoresponsiveness is required to be faster, and the life of the photoconductor itself is extended. Therefore, it is required to increase the speed of light response.

As a measure for extending the life of organic photoreceptors, the relative electrical properties can be increased by increasing the initial film thickness to improve the printing durability of the surface layer in order to reduce changes in the electrical characteristics of the photoreceptor due to long-term use. Attempts have been made to reduce the amount of change in characteristics, and for example, it has been proposed to replace a charge transport layer formed by dispersing a low molecular weight compound in a binder resin with a polymer charge transport material. For example, a polycarbonate obtained by polymerization of a specific dihydroxyarylamine and bischloroformate (for example, see Patent Document 1) and a polycarbonate obtained by polymerization of a specific dihydroxyarylamine and phosgene (for example, see Patent Document 2) are disclosed. ing. Further, a polycarbonate by polymerization of bishydroxyalkylarylamine and bischloroformate or phosgene (for example, see Patent Document 3), or a polycarbonate by polymerization of a specific dihydroxyarylamine or bishydroxyalkylarylamine and bischloroformate. And polyesters by polymerization with bisacyl halides (see, for example, Patent Documents 4 and 5). Furthermore, polycarbonate and polyester of arylamine having a specific fluorene skeleton (see, for example, Patent Document 6) and polyurethane (see, for example, Patent Document 7) are disclosed. Furthermore, a polyester having a specific bisstyryl bisarylamine as a main chain (for example, see Patent Document 8) is disclosed. Further, a polymer having a charge transporting substituent such as hydrazone or triarylamine as a pendant and a photoreceptor using the polymer have been proposed (for example, see Patent Documents 9 to 14). In particular, a polymer having a tetraarylbenzidine skeleton (see, for example, Non-Patent Document 1) has high mobility and high practicality.
US Pat. No. 4,806,443 US Pat. No. 4,806,444 US Pat. No. 4,801,517 US Pat. No. 4,937,165 US Pat. No. 4,959,288 US Pat. No. 5,034,296 U.S. Pat. No. 4,983,482 Japanese Patent Publication No.59-28903 JP-A 61-20953 JP-A-1-134456 Japanese Patent Laid-Open No. 1-134457 Japanese Patent Laid-Open No. 1-134462 Japanese Patent Laid-Open No. 4-130665 JP-A-4-133066 The Sixth International Congress on Advance in Non-impact Printing Technologies. 306, (1990)

  In recent years, there has been a strong demand for on-demand document production from the market. For example, there is a need for technology that can increase output speed and greatly increase the number of printed sheets. There is a strong demand to reduce office costs. However, the prior art as described above still does not sufficiently satisfy these requirements, and further improvement has been demanded.

  This invention makes it a subject to solve the said fault in the past. That is, an object of the present invention is to provide an organic photoconductor for electrophotography having high photoresponsiveness, and an image forming apparatus using the organic photoconductor for electrophotography.

  The inventors of the present invention have been studying mainly a tetraarylbenzidine skeleton having good characteristics, and a polymer charge transport material containing an aromatic diamine skeleton in the main chain, in particular, a polynuclear substituted or unsubstituted at a specific site. It has been found that a polymer charge transport material incorporating an aromatic hydrocarbon, a condensed polycyclic aromatic hydrocarbon, etc. further improves the charge transport ability and printing durability, leading to the invention of the organic photoreceptor of the present invention. In addition, by using the photoconductor, it has become possible to realize a small-sized electrophotographic image forming apparatus capable of high-speed printing and mass printing.

That is, the electrophotographic organic photoreceptor of the present invention is
<1> An electrophotographic organic photoreceptor having a photosensitive layer on a conductive support, wherein at least one layer of the photosensitive layer has a structure represented by the following general formulas (I-1) and (I-2). It has a repeating structure containing at least one selected as the partial structure, electrophotographic organic characterized by containing a polymer charge transporting material is a charge transporting polyether represented by the following general formula (II) It is a photoreceptor.

(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon, a substituted or unsubstituted 2 A condensed polycyclic aromatic hydrocarbon, a substituted or unsubstituted divalent heterocyclic ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon containing at least one heterocyclic ring, or at least one heterocyclic ring; A substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon containing, wherein T is a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched chain having 2 to 10 carbon atoms Represents a hydrocarbon group, 1 represents an integer of 0 to 3, k represents 0 or 1, Ar represents any one of (1), (2) and (6) shown in the following structural group A substituted or unsubstituted monovalent fused polycyclic aromatic hydrocarbon, substituted or unsubstituted containing at least one heterocyclic ring, or Represents an unsubstituted monovalent polynuclear aromatic hydrocarbon or a substituted or unsubstituted monovalent condensed polycyclic aromatic hydrocarbon containing at least one heterocyclic ring.

(In the general formula (II), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and R represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group is represented, and p represents an integer of 5 to 5000.)

< 2 > The organic photoconductor for electrophotography according to <1>, wherein Ar is any one of groups (1) to (6) represented by the following structural group .
<3> The organic photoconductor for electrophotography according to <2>, wherein Ar is any one of groups (1) and (2) shown in the following structural group.

(R ¹ represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, and R ² represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, or a substituted or unsubstituted phenyl group.)

<4> The photosensitive layer has a charge transport layer, and the charge transport layer includes at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure. The organic photoconductor for electrophotography according to <1>, which contains a polymer charge transport material having a structure.
<5> The organic photoconductor for electrophotography according to <4>, wherein the charge transport layer is an outermost layer.
<6> The photosensitive layer has a charge generation layer, and the charge generation layer contains a halogenated gallium phthalocyanine crystal, a halogenated tin phthalocyanine crystal, a hydroxygallium phthalocyanine crystal, or an oxytitanium phthalocyanine hydrate crystal. The organic photoconductor for electrophotography according to <4>.

  <7> An electrophotographic image forming apparatus using the organic photoconductor for electrophotography according to <1>.

  According to the present invention, an organic photoconductor for electrophotography having high photoresponsiveness and excellent printing durability and cleaning property even in an embodiment in which no protective layer is provided, and reduction in size and speed can be achieved. An image forming apparatus can be provided.

The organic photoconductor for electrophotography of the present invention is an electrophotographic organic photoconductor having a photosensitive layer on a conductive support, and at least one layer of the photosensitive layer has the following general formulas (I-1) and (I at least one selected from structures represented by -2) have a repeating structure including as a partial structure, containing a polymer charge transporting material is a charge transporting polyether represented by the general formula below (II) It is characterized by that.

(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon, a substituted or unsubstituted 2 A condensed polycyclic aromatic hydrocarbon, a substituted or unsubstituted divalent heterocyclic ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon containing at least one heterocyclic ring, or at least one heterocyclic ring; A substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon containing, wherein T is a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched chain having 2 to 10 carbon atoms Represents a hydrocarbon group, 1 represents an integer of 0 to 3, k represents 0 or 1, Ar represents any one of (1), (2) and (6) shown in the following structural group A substituted or unsubstituted monovalent fused polycyclic aromatic hydrocarbon, substituted or unsubstituted containing at least one heterocyclic ring, or Represents an unsubstituted monovalent polynuclear aromatic hydrocarbon or a substituted or unsubstituted monovalent condensed polycyclic aromatic hydrocarbon containing at least one heterocyclic ring.

The polymer compound (polymer charge transport material) is not limited to a homopolymer, and can be used after being copolymerized for the purpose of adjusting various physical properties as a functional layer, such as adjustment of ionization potential. A feature of the present invention is that, as described above, substituted or unsubstituted polynuclear aromatic hydrocarbons, condensed polycyclic aromatic hydrocarbons and the like are introduced into Ar in the general formulas (I-1) and (I-2). Therefore, by using the polymer charge transporting material, extremely high photoresponsiveness can be obtained, and in the case where the present invention is not provided with a protective layer, excellent printing durability and cleaning properties are obtained. And an organic photoconductor for electrophotography in which both are compatible.
Here, preferred examples of the group that substitutes for Ar are shown in the following structural groups .

(R ¹ represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, and R ² represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, a substituted or unsubstituted phenyl group.)

In the conventionally used polymer charge transport materials, substituted or unsubstituted polynuclear aromatic hydrocarbons, condensed polycyclic aromatic hydrocarbons and the like are substituted at the position X in the general formulas (I-1) and (I-2). Examples of introduction have been known, but in order to improve the charge transport ability, it was particularly effective to introduce it at the position of Ar as in the present application. This is because these structures forming a wide conjugated form are introduced at the end of the molecule (monomer), and especially when k = 1, two are introduced at both ends of the molecule. This is considered to be due to the effect that the highest occupied orbit, which is referred to in the molecular orbital method to be fulfilled, is greatly expanded rather than being introduced at the position of X. In addition, the introduction of a large conjugated system that is rigid and close to a plane increases the overlap between repeated structures, further improving the charge transport capability, strengthening the interaction between the repeated structures, and greatly improving the mechanical strength. Conceivable.
In addition, when k = 1, two Ars present in the general formulas (I-1) and (I-2) may be the same or different, but from the viewpoint of ease of production Two Ar are preferably the same.

  Next, in the general formulas (I-1) and (I-2), specific examples of T include the following structural formulas.

Among these, those having 2 carbon atoms are useful from the viewpoint of availability of raw materials and avoiding electronic influence of reactive groups for polymerizing. When l is 2 or more, each T may be the same or different. In the general formulas (I-1) and (I-2), the two-(T) _l- existing across the aromatic diamine skeleton are different even though the value of l is the same. The two or more T present across the aromatic diamine skeleton may be the same or different from each other.

  In general formulas (I-1) and (I-2), X is a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon, substituted or unsubstituted. A divalent condensed polycyclic aromatic hydrocarbon, a substituted or unsubstituted divalent heterocycle, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon containing at least one heterocycle, or at least one heterocycle A substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon containing a ring can be used, but in the present invention, since Ar has a relatively large conjugated structure, the structure exemplified below is soluble in a solvent. It is useful in terms of shortening the light absorption wavelength.

(R ³ and R ⁴ represent a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a 2-ethyl-hexyl group, an n-octyl group, a phenyl group, or a tolyl group.)

Hereinafter, preferred specific examples of the structure represented by the general formula (I-1) are shown. The bonding position represents the position (2, 3, 4) where-(T) ₁ -is bonded to the benzene ring as shown in the general formula (I-1). _Two- (T) _l- both have the same binding position.

Moreover, the preferable specific example of the structure shown by general formula (I-2) below is shown. In addition, as shown in the general formula (I-2), the bonding position is a position (2, 3, 4) where the phenylene group is bonded to the benzene ring, and (T) _l is bonded to the benzene ring. The position (2 ′, 3 ′, 4 ′) is represented. When k = 1, both the left and right-(T) ₁ -and phenylene groups have the same bonding position.

Incidentally, polymer charge transporting material of the present invention, Ru charge transporting polyether der represented by the following general formula (II).

(In the general formula (II), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and R represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group is represented, and p represents an integer of 5 to 5000.)

  R in the general formula (II) is usually introduced with a proton in a polymerization reaction. Specifically, as described above, a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or An unsubstituted aralkyl group. From the viewpoint of ease of polymerization of the polyether, R is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 1 to 10 carbon atoms, or an aralkyl group having 1 to 10 carbon atoms.

  Specific examples of the charge transporting polyether represented by the general formula (II) are shown below. In the table below, the numbers in the column A in the monomer column correspond to the structure numbers of specific examples of the structures represented by the general formulas (I-1) and (I-2). Moreover, in the following table, R in the general formula (II) is not shown, but any of the above substituents may be introduced into R.

  In addition, regarding each specific example of the charge transporting polyether numbered with the compound number in the above table, for example, the specific number numbered with 15 is referred to as “Exemplary Compound (15)”.

(Organic photoconductor for electrophotography)
Next, for the electrophotography of the present invention containing a polymer charge transport material having a repeating structure containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure An organic photoreceptor (hereinafter sometimes simply referred to as “photoreceptor”) will be described.

-Charge generation material-
When the photoreceptor of the present invention is used in, for example, an image forming apparatus using a semiconductor laser or the like, it is preferable to use phthalocyanines as the charge generation material. Specifically, the halogenated gallium phthalocyanine crystal disclosed in JP-A-5-98181, the tin halide phthalocyanine crystal disclosed in JP-A-5-140472 and JP-A-5-140473, Hydroxygallium phthalocyanine crystals disclosed in Kaihei 5-263007 and JP-A-5-279591, oxytitanium phthalocyanine hydrate disclosed in JP-A-4-189873 and JP-A-5-43813 Crystals are mentioned, and by using them, an electrophotographic photosensitive member having particularly high sensitivity and excellent repetitive stability can be obtained.

  The chlorogallium phthalocyanine crystal used in the present invention is an mortar, planetary mill, vibration mill, CF, chlorogallium phthalocyanine crystal produced by a known method, as disclosed in JP-A-5-98181. It can be produced by mechanically dry pulverizing with a mill, roller mill, sand mill, kneader or the like, or by dry pulverization and then performing wet pulverization with a solvent using a ball mill, mortar, sand mill, kneader or the like. Solvents used in the above treatment are aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyvalents. Alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide, ether (Diethyl ether, tetrahydrofuran, etc.), several mixed systems, and mixed systems of water and these organic solvents. The solvent used is used in an amount of 1 to 200 parts, preferably 10 to 100 parts, based on chlorogallium phthalocyanine. The treatment temperature is 0 ° C. to the boiling point of the solvent, preferably 10 to 60 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment.

  As disclosed in JP-A-5-140472 and JP-A-5-140473, the dichlorotin phthalocyanine crystal is obtained by converting dichlorotin phthalocyanine crystal produced by a known method in the same manner as the chlorogallium phthalocyanine. It can be obtained by pulverization and solvent treatment.

As disclosed in JP-A-5-263007 and JP-A-5-279591, a hydroxygallium phthalocyanine crystal is obtained by hydrolyzing a chlorogallium phthalocyanine crystal produced by a known method in an acid or alkaline solution. Decomposition or acid pasting to synthesize hydroxygallium phthalocyanine crystals and directly solvent treatment, or wet hydroxygallium phthalocyanine crystals obtained by synthesis using a ball mill, mortar, sand mill, kneader, etc. together with solvent It can be manufactured by performing a pulverization process or performing a dry pulverization process without using a solvent and then performing a solvent process.
As an acid used for acid pasting, sulfuric acid is preferable, and a sulfuric acid having a concentration of 70 to 100%, preferably 95 to 100% is used, and a dissolution temperature is -20 to 100 ° C, more preferably 0 to 60 ° C. Is set. The amount of concentrated sulfuric acid is set in the range of 1 to 100 times, preferably 3 to 50 times the mass of the hydroxygallium phthalocyanine crystal. As a solvent to be precipitated, water or a mixed solvent of water and an organic solvent is used in an arbitrary amount, and water and an alcohol solvent such as methanol or ethanol, or a mixture of water and an aromatic solvent such as benzene or toluene. A solvent is particularly preferred. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation. Moreover, the ratio of the hydroxygallium phthalocyanine crystal and the inorganic salt is 1 / 0.1 to 1/20 in mass ratio, and preferably in the range of 1 / 0.5 to 1/5.
Solvents used in the above solvent treatment include aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic Polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide , Ethers (diethyl ether, tetrahydrofuran, etc.), several mixed systems, and mixed systems of water and these organic solvents. The solvent used is used in an amount of 1 to 200 parts, preferably 10 to 100 parts, based on hydroxygallium phthalocyanine. The treatment temperature is 0 to 150 ° C, preferably room temperature to 100 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The grinding aid is used in a range of 0.5 to 20 times, preferably 1 to 10 times that of the pigment.

As disclosed in JP-A-4-189873 and JP-A-5-43813, the oxytitanium phthalocyanine hydrate crystal is obtained by converting acid-pace oxytitanium phthalocyanine hydrate crystal produced by a known method. Or by performing milling with an inorganic salt using a ball mill, mortar, sand mill, kneader, etc., and hydrated oxytitanium phthalocyanine with a relatively low crystallinity having a peak at 27.2 in the X-ray diffraction spectrum It can be produced by subjecting it to a product crystal and then subjecting it directly to a solvent treatment, or wet grinding using a ball mill, mortar, sand mill, kneader or the like together with a solvent.
As an acid used for acid pasting, sulfuric acid is preferable, and a sulfuric acid having a concentration of 70 to 100%, preferably 95 to 100% is used, and a dissolution temperature is -20 to 100 ° C, more preferably 0 to 60 ° C. Is set. The amount of concentrated sulfuric acid is set in the range of 1 to 100 times, preferably 3 to 50 times the mass of the oxytitanium phthalocyanine hydrate crystal. As a solvent to be precipitated, water or a mixed solvent of water and an organic solvent is used in an arbitrary amount, and water and an alcohol solvent such as methanol or ethanol, or a mixture of water and an aromatic solvent such as benzene or toluene. A solvent is particularly preferred. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation. The ratio of the oxytitanium phthalocyanine hydrate crystal to the inorganic salt is 1 / 0.1 to 1/20 in mass ratio, and preferably in the range of 1 / 0.5 to 1/5.
Solvents used in the above solvent treatment include aromatics (toluene, chlorobenzene, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), halogenated hydrocarbons (dichloromethane, chloroform, trichloroethane, etc.), and There are several types of mixed systems, mixed systems of water and these organic solvents, and the like. The solvent used is used in a range of 1 to 100 times, preferably 5 to 50 times that of oxytitanium phthalocyanine. The treatment temperature is set in the range of room temperature to 100 ° C, preferably 50 to 100 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment.

  Next, the layer structure of the photoreceptor of the present invention will be described. Here, a preferred embodiment of the photoconductor of the present invention will be described in detail mainly using a function-separated type photoconductor (laminated photoconductor) as an example.

  FIG. 1 is a cross-sectional view schematically showing a preferred embodiment of a function-separated type photoreceptor (laminated photoreceptor) according to the present invention. In FIG. 1, an undercoat layer 12, a charge generation layer 13, and a charge transport layer 14 are laminated in this order on a conductive support 11 to form a photosensitive layer 15. The charge transport layer 14 contains a polymer charge transport material having a repeating structure containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure. As a result, the effects of the present invention can be exhibited more remarkably.

  The conductive support 11 is provided with a metal such as aluminum, nickel, chromium, and stainless steel, and a thin film such as aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, and ITO. Examples thereof include a plastic film and the like, or a paper coated with or impregnated with a conductivity imparting agent, and a plastic film. These conductive supports 11 are used in an appropriate shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. Furthermore, if necessary, the surface of the conductive support 11 can be subjected to various treatments within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed. Further, an undercoat layer 12 may be further provided between the conductive support 11 and the charge generation layer 13. The undercoat layer 12 prevents the injection of charges from the conductive support 11 to the photosensitive layer 15 when the photosensitive layer 15 having a laminated structure is charged, and the photosensitive layer 15 is integrated with the conductive support 11. It exhibits an action as an adhesive layer that can be adhered and held, or, in some cases, an antireflection effect of light of the conductive support 11.

  The binder used for the undercoat layer 12 includes polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, vinylidene chloride. Resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium Known materials such as chelate compounds, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents can be used. The thickness of the undercoat layer 12 is 0.01 to 10 μm, preferably 0.05 to 2 μm. Further, as the coating method used when the undercoat layer 12 is provided, conventional methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method and the like are used. Can be used.

  The charge generation layer 13 preferably uses the phthalocyanine crystal described above as the charge generation material, but any known charge generation material such as a bisazo pigment, a phthalocyanine pigment, a squarylium pigment, a perylene pigment, or dibromoanthanthrone is used. be able to. The binder resin used for the charge generation layer 13 can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polyesters such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be used, but is not limited thereto. These binder resins can be used alone or in admixture of two or more.

  Further, the blending ratio (mass ratio) of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10. In addition, as a method for dispersing these, usual methods such as a ball mill dispersion method, an attritor dispersion method, and a sand mill dispersion method can be used. Further, at the time of this dispersion, it is effective to make the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. Moreover, as a solvent used for these dispersions, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, Ordinary organic solvents such as tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more. The thickness of the charge generation layer 13 is 0.01 to 10 μm, preferably 0.05 to 5 μm. Further, as a coating method used when the charge generation layer 13 is provided, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

  For the charge transport layer 14, the polymer charge transport material of the present invention may be used alone, or a known binder resin, other hydrazone charge transport material, triarylamine charge transport material, stilbene charge transport. You may use together with materials. When the binder resin is used, specifically, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride. -Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N- Known resins such as vinyl carbazole and polysilane can be used, but are not limited thereto. Further, as a coating method used when the charge transport layer 14 is provided, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

  The photoreceptor of the present invention is not limited to the above embodiment. For example, the outermost surface layer of the electrophotographic photoreceptor shown in FIG. 1 is the charge transport layer 14, but on the charge transport layer 14, Furthermore, an overcoat layer can be provided and used as the outermost surface layer. Since the polymer charge transport material in the present invention does not contain a low molecule, it has an advantage that various solvents can be used when an overcoat layer is provided on the upper layer.

However, when the charge transport layer 14 includes the polymer charge transport material according to the present invention, it is particularly preferable to use the charge transport layer 14 as the outermost surface layer without providing an overcoat layer. In conventional electrophotographic organic photoreceptors, the charge transport layer does not have printing durability enough to withstand electrophotographic image formation, and usually an overcoat layer must be formed. However, since the charge transport layer containing the polymer charge transport material exhibits very excellent mechanical strength, it is possible to obtain sufficient printing durability without providing an overcoat layer, which enables cost reduction. Become.
In addition, the photoreceptor of the present invention using the charge transport layer 14 as the outermost surface layer is more favorable because it shows a suitable scraping property during cleaning as compared with a photoreceptor having a conventional overcoat layer. Has cleaning properties.

  Furthermore, the charge transport layer 14 containing the polymer charge transport material according to the present invention can be made much thicker than the conventional one, with good cleaning properties due to appropriate scraping during the cleaning. It is possible to extend the life. The thickness of the conventional charge transport layer is usually about 10 to 20 μm, whereas the thickness of the charge transport layer 14 in the present invention can be set to 30 to 80 μm, preferably 30 to 60 μm. Is appropriate.

(Image forming device)
The electrophotographic organic photoreceptor of the present invention is excellent in photoresponsiveness of the surface potential, and it is possible to provide a high-speed image forming apparatus by reducing the diameter of the photoreceptor. Further, as described above, when the polymer charge transporting material according to the present invention is contained in the charge transporting layer, it has excellent printing durability and does not require the formation of an overcoat layer. An image forming apparatus that achieves a long life can be provided.

Hereinafter, an electrophotographic image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 2 shows an example of a schematic configuration diagram of an electrophotographic image forming apparatus using the electrophotographic photosensitive member of the present invention.
In the image forming apparatus 10 shown in FIG. 2, the photosensitive member 1 shown in FIG. 1 is rotatable in the direction of the arrow at a predetermined rotation speed. In the image forming apparatus 10, a charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 7 are arranged in this order along the photosensitive member 1 and its rotation direction. An image fixing device 6 is provided to which the transferred transfer medium 8 is conveyed.

  The conductive member in the charging device 2 may have any shape, such as a brush shape, a blade shape, a pin electrode shape, or a roller shape. Among these, a roller-like member is preferably used. Usually, a roller-shaped member is composed of a resistance layer, an elastic layer that supports them, and a core material from the outside. Furthermore, a protective layer can be provided outside the resistance layer as necessary.

The core material is electrically conductive, and generally iron, copper, brass, stainless steel, aluminum, nickel, etc. are used. In addition, a resin molded product in which conductive particles or the like are dispersed can be used. The material of the elastic layer is conductive or semiconductive, and generally is a rubber material in which conductive particles or semiconductive particles are dispersed. As the rubber material, EPDM, polybutadiene, natural rubber, polyisobutylene, SBR, CR, NBR, silicone rubber, urethane rubber, epichlorohydrin rubber, SBS, thermoplastic elastomer, norbone rubber, fluorosilicone rubber, ethylene oxide rubber and the like are used. Examples of the conductive particles or semiconductive particles include carbon black, zinc, aluminum, copper, iron, nickel, chromium, titanium and other metals, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ — Metal oxides such as SnO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , Sb ₂ O ₃ , In ₂ O ₃ , ZnO, MgO can be used, These materials may be used alone or in admixture of two or more, and fine particles of fluororesin can be used as the fine particles.

As the material of the resistance layer and the protective layer, conductive particles or semiconductive particles are dispersed in a binder resin and the resistance is controlled, and the resistivity is 10 ³ to 10 ¹⁴ Ωcm, preferably 10 ⁵ to. 10 ¹² [Omega] cm, more preferably be set to ¹⁰ 7 ^{~10 12 Ωcm.} The film thickness may be set to 0.01 to 1000 μm, preferably 0.1 to 500 μm, more preferably 0.5 to 100 μm. Binder resins include acrylic resin, cellulose resin, polyamide resin, methoxymethylene nylon, ethoxymethylated nylon, polyurethane resin, polycarbonate resin, polyester resin, polyethylene resin, polyvinyl resin, polyarylate resin, polythiophene resin, polyethylene terephthalate (PET ), Polyolefin resin, styrene butadiene resin or the like is used. As the conductive particles or semiconductive particles, the same carbon black, metal, and metal oxide as those used for the elastic layer are used.

  Moreover, antioxidants, such as hindered phenol and hindered amine, fillers, such as clay and carion, and lubricants, such as silicone oil, can be added as needed. As a means for forming these layers, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, a vacuum deposition method, a plasma coating method, or the like is used. be able to.

  In the image forming apparatus 10 provided with the charging device 2 using these conductive members, when the photosensitive member 1 is charged, a voltage is applied to the conductive member, and the applied voltage is an AC voltage to a DC voltage. Superposed ones are preferable, and it is difficult to obtain uniform charging only with a DC voltage. The voltage range is preferably a positive or negative range of 50 to 2000 V, particularly preferably 100 to 1500 V, with respect to the DC voltage. As the alternating voltage to be superimposed, the peak-to-peak voltage is in the range of 400 to 1800V, preferably 800 to 1800V, and more preferably 1200 to 1800V. When the peak-to-peak voltage exceeds 1800 V, uniform charging cannot be obtained as compared with the case where no AC voltage is superimposed. The frequency of the AC voltage is preferably 100 to 2000 Hz.

  Further, as the exposure apparatus 3, an optical system apparatus that can expose a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surface of the photoreceptor 1 in a desired image-like manner can be used. Among these, it is preferable to use an exposure apparatus capable of exposing non-interference light in that interference fringes between the conductive support (substrate) of the photoreceptor 1 and the photosensitive layer can be prevented.

  The developing device 4 may use either a one-component developer or a two-component developer, and the developer may be either magnetic or non-magnetic. Further, the developing device 4 may be for a monochrome image or a color image.

  Examples of the transfer device 5 include a contact transfer charger using a belt, a roller, a film, a rubber blade, and the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like. Can be used.

  Examples of the fixing device 6 include a heating roller, an IH heater belt, and a xenon flashlight, and can be appropriately selected and used.

  The cleaning device 7 is for removing residual toner adhering to the surface of the photoreceptor 1 after the transfer process. The cleaned photoreceptor 1 is charged, exposed, developed, transferred, and cleaned. The image forming process is repeatedly used. As the cleaning device 7, for example, blade cleaning, brush cleaning, roll cleaning, and the like can be used. Among them, it is preferable to use blade cleaning.

  In addition, the material of the cleaning blade in blade cleaning has elasticity, and includes an elastic body such as rubber, elastomer, resin, etc. in terms of durability and easy compatibility with the surface of the electrophotographic photosensitive member, among which rubber is preferable, For example, urethane rubber, neoprene rubber, silicone rubber and the like.

  In addition, this embodiment is an example of embodiment in this invention, Naturally, it is not limited to this. For example, the image forming apparatus 10 shown in FIG. 2 may be applicable to a process cartridge including the photoreceptor 1 and the developing device 4 and / or the cleaning device 7. By using such a process cartridge, maintenance can be performed more easily.

  The apparatus shown in FIG. 2 directly transfers the toner image formed on the surface of the photoreceptor 1 to the transfer medium 8, but the image forming apparatus 10 of the present invention further includes an intermediate transfer body. There may be. As a result, after the toner image on the surface of the photoreceptor 1 is transferred to the intermediate transfer member, it can be transferred from the intermediate transfer member to the transfer medium 8. As such an intermediate transfer member, one having a structure in which an elastic layer containing rubber, elastomer, resin or the like and at least one coating layer are laminated on a conductive support can be suitably used.

  Furthermore, the photoreceptor according to the present invention can be suitably applied not only to a monochrome electrophotographic apparatus but also to a color electrophotographic apparatus. As a color image output method, a method in which a toner image of a plurality of colors is formed on a photoconductor and each color toner image is transferred to a transfer paper, or a toner image formed on the photoconductor is transferred to an intermediate transfer material, A method of further transferring the toner image on the transfer member to the transfer medium, a method of superimposing a plurality of toner images on the photosensitive member to form a color toner image corresponding to the image, and transferring the color toner images at once. Can be mentioned.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the following, “part” is based on mass.

Example 1
On a roughened 20 mmφ stainless steel cylindrical substrate, 100 parts of a zirconium compound (trade name: ORGATICS ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 10 parts of a silane compound (trade name: A1110, manufactured by Nihon Junker) and i-propanol A solution composed of 400 parts and 200 parts of butanol was applied by a dip coating method and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.5 μm. 10 parts of dichlorotin phthalocyanine as a charge generating material is mixed with 10 parts of polyvinyl butyral resin (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 500 parts of n-butyl acetate, and treated with a glass shaker for 1 hour. Then, the obtained coating solution was applied onto the undercoat layer by a dip coating method and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer. 7 parts of the charge transporting polymer of the exemplified compound (81) as a charge transporting material is dissolved in 38 parts of monochlorobenzene, and the resulting coating solution is dip coated on a stainless steel cylindrical substrate on which a charge generation layer is formed. The film was applied by the method and dried by heating at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 55 μm.

= Evaluation =
The electrophotographic characteristics of the electrophotographic organic photoreceptor thus obtained were measured in a normal environment (20 in the laser beam printer test model-1 (A-4 lateral direction, 36 sheets per minute) manufactured by Fuji Xerox Co., Ltd. A print test was performed under the condition of [° C., 50% RH], and the image quality after the first copy and the 5000th copy was evaluated. The exposure amount was adjusted using a filter depending on the sensitivity of the charge generation material.
In addition, the thickness of the entire photosensitive layer of the electrophotographic photosensitive member was measured using an electromagnetic film thickness meter LE-200J manufactured by Kett Co., Ltd. After evaluation from the film thickness before image quality evaluation (after 50000 copies) ) To obtain the amount of wear of the outermost surface layer (charge transport layer 14). The evaluation results are shown in Table 18.

(Example 2)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge generation material was changed to chlorogallium phthalocyanine.

(Example 3)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge generation material was changed to hydroxygallium phthalocyanine.

Example 4
An organophotoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge generation material was changed to oxotitanium phthalocyanine.

(Example 5)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (13).

(Example 6)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (13).

(Example 7)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 3 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (13).

(Example 8)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 4 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (13).

Example 9
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (51).

(Example 10)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (51).

(Example 11)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 3 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (51).

(Example 12)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 4 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (51).

(Example 13)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (54). .

(Example 14)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (54).

(Example 15)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 3 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (54).

(Example 16)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 4 except that the charge transporting material was changed to the charge transporting polymer of the exemplified compound (54).

(Comparative Example 1)
An organic photoconductor was prepared and evaluated in the same manner as in Example 1 except that the charge transport material was changed to the following comparative compound 1 (Mw = 4.5 × 10 ⁴ (styrene conversion), Mn / Mw = 2.1). Went.

(Comparative Example 2)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 1 except that the charge generation material was changed to chlorogallium phthalocyanine.

(Comparative Example 3)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 1 except that the charge generating material was changed to hydroxygallium phthalocyanine.

(Comparative Example 4)
An organophotoreceptor was prepared and evaluated in the same manner as in Comparative Example 1 except that the charge generation material was changed to oxotitanium phthalocyanine.

(Comparative Example 5)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transport material was changed to the following comparative compound 2 (Mw = 7.3 × 10 ⁴ (styrene conversion), Mn / Mw = 1.9). Went.

(Comparative Example 6)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 5 except that the charge generation material was changed to chlorogallium phthalocyanine.

(Comparative Example 7)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 5 except that the charge generating material was changed to hydroxygallium phthalocyanine.

(Comparative Example 8)
An organophotoreceptor was prepared and evaluated in the same manner as in Comparative Example 5 except that the charge generation material was changed to oxotitanium phthalocyanine.

(Comparative Example 9)
An organic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transport material was changed to the following comparative compound 3 (Mw = 8.2 × 10 ⁴ (in terms of styrene), Mn / Mw = 2.2). Went.

(Comparative Example 10)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 9 except that the charge generation material was changed to chlorogallium phthalocyanine.

(Comparative Example 11)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 9 except that the charge generating material was changed to hydroxygallium phthalocyanine.

(Comparative Example 12)
An organic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 9 except that the charge generation material was changed to oxotitanium phthalocyanine.

The organophotoreceptors shown in Comparative Examples 1 to 4 using a tetraphenylphenylbenzidine-based polymer charge transport material and the electrophotographic image forming apparatus using the same are optically responsive when the charge transport layer is as thick as 55 μm. Therefore, a satisfactory image cannot be obtained due to insufficient properties, and a satisfactory image cannot be obtained after printing 5000 sheets due to insufficient charge potential due to wear of the charge transport layer. In Comparative Examples 5 to 8 and 9 to 12, the light response in the initial stage and the change in characteristics after printing 5000 sheets are extremely large.
On the other hand, as shown in Examples 1 to 16, the organophotoreceptor of the present invention and the electrophotographic image forming apparatus using the organophotoreceptor have high speed photoresponsiveness even under the condition that the charge transport layer is as thick as 55 μm. Due to the excellent printing durability and excellent printing durability, the change in characteristics after printing 5000 sheets is extremely small, and an organic photoreceptor and an image forming apparatus having a small size, high speed, and long life can be provided.

1 is a cross-sectional view schematically showing one embodiment of a layer configuration of an electrophotographic organic photoreceptor of the present invention. 1 is a schematic configuration diagram schematically showing an embodiment of an electrophotographic image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Image fixing apparatus 7 Cleaning apparatus 10 Image forming apparatus 11 Conductive support body 12 Undercoat layer 13 Charge generation layer 14 Charge transport layer 15 Photosensitive layer

Claims (4)

An electrophotographic organic photoreceptor having a photosensitive layer on a conductive support,
The photosensitive layer of the at least one layer, have a repeating structure containing at least one selected from structures represented by the following general formula (I-1) and (I-2) as a partial structure represented by the following general formula (II) An organic photoconductor for electrophotography comprising a polymer charge transporting material which is a charge transporting polyether represented by the formula:


(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon, a substituted or unsubstituted 2 A condensed polycyclic aromatic hydrocarbon, a substituted or unsubstituted divalent heterocyclic ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon containing at least one heterocyclic ring, or at least one heterocyclic ring; A substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon containing, wherein T is a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched chain having 2 to 10 carbon atoms Represents a hydrocarbon group, 1 represents an integer of 0 to 3, k represents 0 or 1, Ar represents any group represented by the following structural group 1 , substituted or unsubstituted monovalent Fused polycyclic aromatic hydrocarbons, substituted or unsubstituted monovalent poly containing at least one heterocycle It represents a monovalent condensed polycyclic aromatic hydrocarbon substituted or unsubstituted containing aromatic hydrocarbon or at least one heterocyclic ring.)


(R ¹ represents a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms.)


(In the general formula (II), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and R represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group is represented, and p represents an integer of 5 to 5000.) 2. The organic photoconductor for electrophotography according to claim 1, wherein Ar is any group shown in the following structural group 2.


(R ¹ Represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, and R ² Represents a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, or a substituted or unsubstituted phenyl group. ) 3. The organic photoconductor for electrophotography according to claim 2, wherein Ar is any group represented by the following structural group 3.


(R ¹ Represents a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. ) An electrophotographic image forming apparatus using the electrophotographic organic photoreceptor according to any one of claims 1 to 3 .