JP2007171338A - Electrophotographic photoreceptor for liquid development and electrophotographic device equipped with this photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor for liquid development which has high durability against a carrier solvent and is practically highly sensitive and to provide a liquid development electrophotographic device in a wet development system equipped with the photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor is constituted by forming a single layer of photosensitive layer directly or via an intermediate layer on a conductive support, the photosensitive layer containing a polymer charge transporting substance having a specified polycarbonate structure, a charge generating substance and an acceptor compound (2,3-diphenyl indene compound). The liquid development electrophotographic device 11 comprises the electrophotographic photoreceptor 10, a charging means 1, an image exposing means 3, a developing means 4, a cleaning means 8 and a transfer means 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive pair, and more particularly, to an electrophotographic photosensitive member for liquid development used in a liquid developing type (wet developing type) electrophotographic apparatus using a developing solution in which toner particles are dispersed in a liquid, and The present invention relates to an electrophotographic apparatus provided with a photoreceptor.

  Conventionally, as a photoconductor for a photoconductor used in an electrophotographic system, an inorganic photoconductor and an organic photoconductor are widely known. The “electrophotographic method” here generally means that a photoconductive photosensitive member is first charged in a dark place, for example, by corona discharge, and then image-exposed to selectively dissipate the charge of only the exposed portion. An image called the so-called Carlson process, in which an electrostatic latent image is obtained, and the latent image portion is developed with a toner composed of a colorant such as a dye or pigment and a polymer material and visualized to form an image. Forming process.

  Electrophotographic development methods using the Carlson process are roughly classified into dry development methods and wet (or liquid) development methods. An image forming apparatus using a dry development system is currently widely used, such as a copying machine and a printer. On the other hand, image forming apparatuses using a wet developing method have been developed and commercialized for a long time, but at present, image forming apparatuses using a dry developing method occupy most of the market.

  However, in general, an image forming apparatus using a wet development system can make toner particles very fine because toner is dispersed in a liquid, and an image obtained has a very high image quality. . For this reason, with the expansion of the market for full-color printers that demand high image quality in recent years, it has been attracting attention again and is being developed.

  As described above, since the image forming apparatus using the wet developing system uses a developing solution in which toner particles are dispersed in a liquid, all or a part of the photoreceptor to be used is immersed in the developing solution. As the liquid (carrier solvent) used in the developing solution, for example, an aliphatic hydrocarbon solvent called Isopar (manufactured by Exxon Chemicals) or silicone oil is mainly used. In general, an inorganic photoconductor such as selenium or amorphous silicon in which the photoconductor component does not elute in the carrier solvent is used.

  On the other hand, photoconductors using organic photoconductors have a higher degree of freedom in the photosensitive wavelength range, film formability, flexibility, film transparency, mass productivity, toxicity, cost, etc. compared to inorganic photoconductors. Therefore, a photoreceptor using an organic material has been actively developed and put into practical use.

  This type of organophotoreceptor is either a layered photoreceptor composed of a charge generation layer responsible for charge generation and a charge transport layer responsible for charge transport, or a single-layer type comprising both a charge generation function and a charge transport function. Broadly divided. The former has a structure in which a charge generation layer and a charge transport layer are laminated in this order on a conductive support, and the negative charging method is mainly applied to an image forming apparatus due to restrictions on organic materials, and is excellent in photosensitive characteristics and durability. Widely used. Similarly, the latter has a layer structure in which a single-layer type photosensitive layer is provided on a conductive support, and a positively charged structure in which high resolution can be easily obtained in principle.

  Inorganic photoreceptors such as selenium and amorphous silicon, which are generally used in image forming apparatuses utilizing the wet development system, are usually used with positive charging. Therefore, when replacing the conventionally used inorganic photoreceptor with an organic photoreceptor, it is advantageous because the single-layer photoreceptor can be used in the same positive charging system.

  When using a general organic photoreceptor for an image forming apparatus utilizing a wet development system, all or a part of the photoreceptor used as described above is immersed in a liquid developer solution (carrier solvent). Cracking due to contact with carrier solvent, crystallization of low molecular weight compounds such as charge transport materials and / or acceptor compounds, or elution into developer, etc. As a result, a good image cannot be obtained.

  In order to cope with this, an organic photoconductor in which a thermosetting resin insoluble in a liquid developer such as a silicon resin, an epoxy resin, or a melamine resin is further provided as an overcoat (surface protective layer) on the surface of the organic photoconductor. However, there is a new major problem that the sensitivity is remarkably deteriorated and the manufacturing cost is increased by applying the overcoat.

On the other hand, a method in which no overcoat is applied has been proposed (for example, see Patent Documents 1 to 6). That is, by using a specific binder resin as a single-layer photoreceptor that can be used in the wet development system, the resistance to the carrier solvent used in the wet development system is increased, and the elution of the charge transport material to the carrier solvent is prevented. However, a technique for producing a single-layer photoreceptor having practical sensitivity is disclosed.
However, such a technique is to improve the resistance to a carrier solvent with a low polarity by using a so-called relatively high binder resin, essentially elution of the charge transport material is inevitable, There is a problem that it cannot withstand long-term use.

  Further, a copolymer composed of a chemical structure block having a charge transport function and a chemical structure block having a function as a binder resin, and a single-layer photoconductor using the same have been proposed (for example, see Patent Document 7). .) And when such a copolymer is used for an electrophotographic photoreceptor of a wet development type, it is said that elution of a low molecular compound by a liquid developer can be prevented. However, a single-layer photoreceptor composed of this copolymer is not necessarily sensitive enough to meet market demands.

Furthermore, a copolymer composed of a chemical structure block having a charge transport function and a chemical structure block having a function as a binder resin, and a single-layer photoreceptor using the copolymer have been proposed (for example, see Patent Document 8). .)
However, since this copolymer has a chemical structure block having a charge transport function of 30 to 15 mol%, the charge transport ability is insufficient. When charge transport is carried out only by this copolymer, sufficient sensitivity cannot be obtained, and it is necessary to add a low molecular charge transport material as shown in the Examples. When such a photoreceptor is used for a wet development type electrophotographic photoreceptor, elution of a low molecular charge transport material by a liquid developer is inevitable and cannot be used for a long time.

The Applicant previously has a dioxy group having an aryloxy group and at least one triarylamine group, wherein the hydroxyl group is substituted with an aryl group on the aryloxy group bonded to the aryl group of the triarylamine group. An electrophotographic photosensitive member provided with a photosensitive layer containing an aromatic polycarbonate resin derived from phenol as an active ingredient has been proposed (for example, see Patent Document 9). Alternatively, on the divalent group of the alkane having an aryl group substituted with an aryl group having an aryl group substituted with an aryl group bonded to the aryl ring of the triarylamine group and having at least one triarylamine group substituted with an aryl group An electrophotographic photoreceptor provided with a photosensitive layer containing an aromatic polycarbonate resin derived from diphenol having an aryl group substituted with a hydroxyl group as an active ingredient has been proposed (for example, see Patent Document 10).
The photoreceptors in Patent Documents 9 and 10 are intended to be used in an image forming apparatus that utilizes a dry development system, and the structure of the photoreceptor is also a laminated structure as shown in the examples.

JP 2002-116560 A JP 2002-131943 A JP 2002-351101 A JP 2002-40677 A JP 2000-214610 A JP 2003-5391 A JP 2000-63456 A JP 2003-57856 A JP 2001-247525 A JP 2002-249472 A

  The present invention has been made in consideration of the above-described circumstances, and has high resistance to a carrier solvent and is practically highly sensitive for liquid development, which is used in a wet development type liquid development electrophotographic apparatus. It is an object of the present invention to provide a photographic photosensitive member and an electrophotographic apparatus provided with the photosensitive member.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by forming a single-layer photosensitive layer containing a polymer charge transport material, a charge generation material, and an acceptor compound having a specific polycarbonate structure. The headline has led to the present invention. Hereinafter, the present invention will be specifically described.

That is, the present invention relates to an electrophotographic photosensitive member for liquid development used in an image forming apparatus of a wet development type.
The photoreceptor includes a simple substance containing at least a polymer charge transporting material represented by the following general formula (1), a charge generating material, and an acceptor compound on a conductive support directly or via an intermediate layer. An electrophotographic photosensitive member for liquid development, comprising a photosensitive layer as a layer.

{In Formula (1), Ar ₁ , Ar ₂ , Ar ₄ , and Ar ₅ represent a substituted or unsubstituted arylene group, and Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group or —O—. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  The polymer charge transport material having the above structure not only has high resistance to the carrier solvent used in the liquid development method itself, but also interacts with a low molecular compound (for example, an acceptor compound) that forms the photosensitive layer. In order to prevent elution into the carrier solvent, the mechanical or electrical characteristics do not deteriorate even when used for a long time. In addition, other components in the polymer charge transport material matrix are homogeneously dispersed in the molecular order, and smooth charge transfer is performed, thereby achieving high sensitivity.

  In the electrophotographic photosensitive member for liquid development according to the present invention, the polymer charge transport material is represented by the following general formula (2).

{In Formula (2), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  By using the polymer charge transporting material represented by the general formula (2), it has excellent resistance to carrier solvents (for example, aliphatic hydrocarbon solvents, silicone oils, etc.), and electrophotographic characteristics even after long-term immersion. Excellent electrophotographic photosensitive member for liquid development can be obtained.

  In the electrophotographic photosensitive member for liquid development according to the present invention, the polymer charge transporting material is represented by the following general formula (3).

{In Formula (3), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  By using the polymer charge transport material represented by the above general formula (3), it has excellent wear characteristics and resistance to carrier solvents (for example, aliphatic hydrocarbon solvents, silicone oils, etc.), and after long-term immersion. In addition, an electrophotographic photosensitive member for liquid development having better electrophotographic characteristics can be obtained.

  Furthermore, the present invention provides a polymer charge transport material having a repeating unit represented by the general formula (1), the general formula (2) or the general formula (3) in any one of the electrophotographic photosensitive members for liquid development described above. The weight average molecular weight (in terms of polystyrene) of is 20,000 to 1,000,000 as measured by gel permeation chromatography.

  By setting the average molecular weight of the polymer charge transporting material to 20000 to 1000000 (weight in terms of polystyrene), the coating property and film forming property are maintained well, and the resistance to the carrier solvent is increased. As a result, a high-quality image can be formed without deterioration of the photosensitive layer over time.

  Furthermore, the present invention is characterized in that in any one of the electrophotographic photoreceptors for liquid development, the acceptor compound is a 2,3-diphenylindene compound represented by the following general formula (F1).

(Wherein, f ₁ , f ₂ , f ₃ , and f ₄ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, or a nitro group, and A and B are a hydrogen atom, substituted or unsubstituted Represents a substituted aryl group, a cyano group, an alkoxycarbonyl group, or an aryloxycarbonyl group.)

  By using the acceptor compound, charge transfer of the photosensitive layer is favorably performed, and an electrophotographic photoreceptor for liquid development excellent in electrophotographic characteristics can be obtained.

  Furthermore, the invention is characterized in that in any one of the electrophotographic photoconductors for liquid development, the photosensitive layer contains at least one phenol compound represented by the following general formula (G1).

(Wherein g _{1 to} g ₈ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkoxy group.)

  By using the phenol compound, an electrophotographic photosensitive member for liquid development in which the repeated mechanical durability and sensitivity of the photosensitive member are further improved can be obtained.

  According to another aspect of the present invention, there is provided a liquid developing electrophotographic apparatus comprising the liquid developing electrophotographic photosensitive member according to any one of the above, a charging unit, an image exposing unit, a developing unit, a cleaning unit, and a transfer unit. It is concerned.

  According to the liquid developing electrophotographic apparatus, the photoreceptor is not deteriorated over time, and a stable and high-quality image is always formed. For this reason, it can be applied to, for example, a full-color printer that requires high image quality.

The carrier used in the liquid developing system is provided with a single photosensitive layer containing at least the polymer charge transporting material represented by the general formula (1), the charge generating material and the acceptor compound of the present invention. It is possible to realize an electrophotographic photosensitive member having extremely high resistance of the photosensitive layer to a solvent and practically high sensitivity. Therefore, it can be applied to a liquid development system that is promising in improving image quality. In particular, when the polymer charge transporting material represented by the general formula (2) or (3) is used, the electrophotographic photosensitive member for liquid development having excellent resistance to a carrier solvent and excellent electrophotographic characteristics even in long-term use. Is obtained.
According to the electrophotographic apparatus according to the present invention having the above photoreceptor, high-quality image formation can be performed because there is no mechanical and electrical deterioration of the photoreceptor over time. The electrophotographic apparatus of the present invention can be adapted from a low speed to a high speed copying process, and can be used as various printing apparatuses such as a high-quality full-color printer.

As described above, the electrophotographic photosensitive member for liquid development in the present invention is an electrophotographic photosensitive member for liquid development used in an image forming apparatus of a wet development type.
The photoreceptor includes a simple substance containing at least a polymer charge transporting material represented by the following general formula (1), a charge generating material, and an acceptor compound on a conductive support directly or via an intermediate layer. A photosensitive layer is provided as a layer.

{In Formula (1), Ar ₁ , Ar ₂ , Ar ₄ , and Ar ₅ represent a substituted or unsubstituted arylene group, and Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group or —O—. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  Here, the polymer charge transport material is preferably represented by the following general formula (2).

{In Formula (2), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  Alternatively, the polymer charge transport material is preferably represented by the following general formula (3).

{In Formula (3), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }

  The electrophotographic photosensitive member for liquid development of the present invention is excellent in carrier solvent resistance, chargeability and sensitivity, suitable for a low-speed to high-speed copying process, and spectral sensitivity can be controlled by changing the charge generating substance. In addition, it is possible to apply from a monochrome or full-color analog copying machine to a photoconductor for a page printer using LD or LED light for optical writing.

Hereinafter, embodiments to which the present invention is applied will be described in detail.
Of particular importance in the photosensitive layer relating to the liquid developing photoreceptor of the present invention is the use of a polymeric charge transport material as the charge transport material. This achieves a single-layer electrophotographic photosensitive member that has a very high resistance to the carrier solvent used in the liquid development method and is practically highly sensitive. The reason for this is not clear at this time, but is presumed as follows.
The polymer charge transport material having a specific structure of the present invention has high resistance to a carrier solvent used in a liquid development system. In particular, as described later, it is considered that the resistance to the carrier solvent is further increased by using a higher molecular weight compound (polystyrene equivalent weight average molecular weight of 20000 to 1000000) than conventionally used.

  Furthermore, the low molecular weight compound such as the acceptor compound having the specific structure or the phenol compound having the specific structure present in the matrix composed of such a polymer charge transport material having a strong carrier solvent resistance is a polymer charge transport material. There is no problem such as some kind of interaction between them and the low molecular weight compound eluting into the carrier solvent. As a result, the electrophotographic photoreceptor containing the polymer charge transporting material of the present invention is extremely resistant to the carrier solvent. Presumed to be higher.

  As the interaction, for example, an acceptor compound having a specific structure is assumed to be based on an intermolecular charge transfer with a polymer charge transport material, and a phenol compound having a specific structure is a hydrogen bond with a polymer charge transport material, Alternatively, an interaction based on van der Waals forces is assumed. In addition, the structure factors of the polymer charge transporting substance, acceptor compound, and phenol compound used in the present invention are also important for the above interaction, and it is speculated that the purpose is achieved by their synergistic effect. .

  On the other hand, the following can be considered for higher sensitivity. That is, a very homogeneous polymer matrix (dispersed in the molecular order) is formed on the basis of the above interaction, and the charge is well injected from the charge generating material into the charge transfer matrix, and the smooth movement in the matrix is performed. It is estimated that high sensitivity can be achieved.

  Furthermore, a major feature of the polymer charge transporting material represented by the general formula (1) used in the photosensitive layer related to the liquid developing photoreceptor in the present invention is that the amount of wear in the Taber abrasion test by the following evaluation method is extremely high. It is very rare. This is because the polymer charge transporting material represented by the general formula (1) forms a strong intermolecular interaction, and as a result, the photoreceptor is extremely resistant to the carrier solvent used in the liquid development system. This is thought to have increased.

<Taber abrasion test>
The Taber abrasion test is, for example, a sample in which a film made of a polymer charge transport material represented by the general formula (1) (for example, the exemplified compound (D-11)) is formed on an aluminum plate support; Comparative sample (on the aluminum plate support, for example, a film made of polycarbonate Z (PC-Z; manufactured by Teijin Chemicals) used in Comparative Example 1 described later: low-molecular charge transfer substance (T-1) = 10: 7) The formed sample) is subjected to a wear test, and each wear amount is measured and compared.
That is, the film surface of each sample was subjected to a wear test of 3000 revolutions using a CS-5 wear wheel in a Taber abrasion test (manufactured by Toyo Seiki Co., Ltd.) according to the industrial standard JIS K7204 (1995). taking measurement. For example, as a result of this evaluation, (D-11) film / comparative film = 0.16, and the (D-11) film has a very small amount of wear.

  Hereinafter, the general formula (1) representing the polymer charge transporting substance which is a main constituent unit in the present invention will be described in more detail.

In the polymer charge transport material represented by the general formula (1), the aryl group represented by Ar ₃ in the formula includes an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a pyrenyl group, a 2-fluorenyl group, 9 , 9-dimethyl-2-fluorenyl group, azulenyl group, anthryl group, triphenylenyl group, chrycenyl group, fluorenylidenephenyl group, 5H-dibenzo [a, d] cycloheptenylidenephenyl group, etc., condensed polycyclic groups, biphenylyl And non-condensed polycyclic groups such as terphenylyl group, heterocyclic groups such as chenyl group, benzocenyl group, furyl group, benzofuranyl group, and carbazolyl group.

Examples of the arylene group of Ar ₁ , Ar ₂ , Ar ₄ , and Ar ₅ include a divalent group of an aryl group represented by Ar ₃ .
The aryl group and arylene group may have the following substituents.

  (1) Halogen atom, trifluoromethyl group, cyano group, nitro group.

  (2) Alkyl group: preferably an alkyl group having 1 to 12 carbon atoms (substantially, C1 to C12; hereinafter also abbreviated), particularly C1 to C8, more preferably C1 to C4 linear or branched alkyl. These alkyl groups are further substituted with fluorine atoms, hydroxyl groups, cyano groups, C1-C4 alkoxy groups, phenyl groups, halogen atoms, C1-C4 alkyl groups or C1-C4 alkyl groups. It may contain a phenyl group. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-hydroxyethyl Group, 2-cyanoethyl group, 2-ethoxyethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-methoxybenzyl group, 4-phenylbenzyl group and the like.

(3) Represented by an alkoxy group [(—OR ₃₁ ). ]: R ₃₁ represents the alkyl group shown in the above (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, 2-cyano Examples include ethoxy group, benzyloxy group, 4-methylbenzyloxy group, trifluoromethoxy group and the like.

  (4) Aryloxy group: Examples of the aryl group include a phenyl group and a naphthyl group. These may contain a C1-C4 alkoxy group, a C1-C4 alkyl group or a halogen atom as a substituent. Specific examples include phenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, 4-methylphenoxy group, 4-methoxyphenoxy group, 4-chlorophenoxy group, 6-methyl-2-naphthyloxy group and the like. It is done.

  (5) Substituted mercapto group or aryl mercapto group: Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.

  (6) Alkyl-substituted amino group: The alkyl group represents the alkyl group shown in the above (2). Specific examples include a dimethylamino group, a diethylamino group, an N-methyl-N-propylamino group, and an N, N-dibenzylamino group.

  (7) Acyl group: Specific examples include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.

The alkylene group for R ₁ , R ₂ and Za is a C1-C8, preferably C1-C4 linear or branched alkylene group, specifically a methylene group, an ethylene group, or n-propylene. Group, i-propylene group, s-butylene group, n-butylene group, i-butylene group, n-hexylene group, n-octylene group and the like.

  X is introduced into the main chain by using the diol compound of the following general formula (5) together when the diol compound of the following general formula (4) is polymerized using the phosgene method, the transesterification method or the like.

(In the formula (4), Ar ₁ , Ar ₂ , Ar ₄ , Ar ₅ , Ar ₃ , Z, R ₁ and R ₂ are all synonymous with the formula (1).)

(In Formula (5), X is synonymous with said Formula (1).)

In the above case, the produced polycarbonate resin is a random copolymer or a block copolymer.
X is also introduced into the repeating unit by a polymerization reaction of a diol compound having a triarylamino group of the general formula (4) and a bischloroformate derived from the general formula (5). In this case, the produced polycarbonate becomes an alternating copolymer.

Specific examples of the diol compound of the general formula (5) include the following.
1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2-methyl-1,3 -Aliphatic diols such as propanediol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene ether glycol, And cycloaliphatic diols such as 4-cyclohexanediol, 1,3-cyclohexanediol, and cyclohexane-1,4-dimethanol. Examples of the diol having an aromatic ring include 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 1,1bis (4-hydroxyphenyl). -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1 , 1-bis (4-hydroxyphenyl) cyclopentane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2 -Bis (4-hydroxyphenyl) butane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propa 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 3,3 '-Dimethyl-4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl oxide, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxyphenyl) xanthene, ethylene glycol-bis (4-hydroxybenzoate), diethylene glycol-bis (4-hydroxybenzoate), triethylene glycol-bis (4-hydroxybenzoate), 1,3- Bis (4-hydr Kishifeniru) - tetramethyl disiloxane, and the like phenol-modified silicone oil.

Specific examples of the method for synthesizing the polymer charge transport materials represented by the general formulas (1) to (3) and specific examples of the charge transport materials (for example, JP 2001-247525 A, JP 2002-2002 A) 249472) can be used.
Although the exemplary compound of General formula (1) is shown in following Table 1-Table 3, this embodiment is not limited to these.

  The amount of the polymer charge transport material used in the present invention in the entire photosensitive layer is 20 to 95% by weight, preferably 30 to 90% by weight.

  The preferred molecular weight of the polymer represented by the above general formula is 20,000 to 1,000,000, more preferably 50,000 to 500,000 in terms of polystyrene-converted weight average molecular weight in gel permeation chromatography. When the molecular weight is too smaller than 7000, the practicality such as the deterioration of film forming property such as generation of cracks and the lack of carrier liquid resistance becomes poor. On the other hand, when the molecular weight is larger than 1000000, the solubility in a general organic solvent is deteriorated, the viscosity of the solution becomes high, and the coating becomes difficult, which is also a practical problem.

  The polymer charge transport material (polymer) in the present invention exhibits good solubility in various commonly used organic solvents such as dichloromethane, tetrahydrofuran, chloroform, toluene, monochlorobenzene and xylene. Therefore, a solution having an appropriate concentration can be prepared with an appropriate solvent capable of dissolving the polymer of the present invention, and various photoconductors can be prepared by a known coating method using the solution.

  Furthermore, in the photosensitive layer of this embodiment, an acceptor compound is included as an essential component. The acceptor compound 2,3-diphenylindene compound represented by the following general formula (F1), which is the main structural unit of the present embodiment, will be further described.

(Wherein, f ₁ , f ₂ , f ₃ , and f ₄ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, or a nitro group, and A and B are a hydrogen atom, substituted or unsubstituted Represents a substituted aryl group, a cyano group, an alkoxycarbonyl group, or an aryloxycarbonyl group.)

More specifically, in the 2,3-diphenylindene compound of the general formula (F1), f _{1 to} f ₄ are each a halogen atom such as a hydrogen atom, a fluorine atom or a chlorine atom, a methyl group, an ethyl group, or n-propyl. Represents a group, an alkyl group such as an iso-propyl group, an n-butyl group or a t-butyl group, a substituted alkyl group such as a benzyl group, a methoxymethyl group or a methoxyethyl group, a cyano group, or a nitro group. A and B are a hydrogen atom, a halogen atom such as a fluorine atom or a chlorine atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group or a t-butyl group, or a benzyl group. , Substituted alkyl groups such as methoxymethyl group and methoxyethyl group, cyano, group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, substituted alkylcarbonyl groups such as benzyloxycarbonyl group and methoxyethylcarbonyl group, phenyl group, Examples of the aryl group such as naphthyl group and the substituent include alkyl groups such as methyl group and ethyl group, and halogen atoms such as phenyl group, methoxy group, ethoxy group, phenoxy group, fluorine atom and chlorine atom.

  As a specific example of the method for synthesizing the acceptor compound represented by the general formula (F1), a known method (for example, described in JP-A-7-300434) can be used.

  In particular, in the general formula (F1), (2,3-diphenyl-1-indene) malonnitrile represented by the following formula (A-1) is preferably used.

  In addition, as an acceptor compound that can be used in the present embodiment, a known compound can also be used. For example, chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7- Tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-indeno4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene- 5, 5-Dioxide etc. can be mentioned, Furthermore, the acceptor property compound shown to the following general formula (A-2), (A-3), (A-4) can be used conveniently.

  These organic acceptor compounds may be used alone or in combination of two or more. The amount of these organic acceptor compounds in the photosensitive layer is 1 to 40% by weight, preferably 5 to 40% by weight.

  Furthermore, the photosensitive layer of this embodiment contains a phenol compound as necessary. The phenol compound represented by the following general formula (G1), which is the main structural unit of the present embodiment, will be further described.

(Wherein g _{1 to} g ₈ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkoxy group.)

More specifically, in the phenol compound of the general formula (G1), g _{1 to} g ₈ are hydrogen atom, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, t-butyl. Alkyl group such as benzyl group, substituted alkyl group such as benzyl group, methoxymethyl group and methoxyethyl group, alkoxycarbonyl group such as methoxycarbonyl group and ethoxycarbonyl group, substituted alkylcarbonyl group such as benzyloxycarbonyl group and methoxyethylcarbonyl group Aryl groups such as phenyl and naphthyl groups, and substituents thereof include alkyl groups such as methyl and ethyl groups, and halogen atoms such as phenyl, methoxy, ethoxy, phenoxy, fluorine and chlorine atoms. Can do.

  As a specific example of the synthesis method of the phenol compound represented by the general formula (G1), a known method (for example, described in JP-A-10-133400) can be used.

  The content of these phenol compounds in the photosensitive layer is 0.1 to 50% by weight, preferably 0.1 to 30% by weight. If it is 0.1% by weight or less, the effect of improving the repeated durability is not sufficient, and if it is 50% by weight or more, the mechanical durability is lowered and the sensitivity is lowered.

  Specific examples of the phenol compound of the present embodiment include those shown in the following structural formulas (No. G1) to (No. G8), but are not limited thereto.

In the photoreceptor of the present invention, a charge generating material is included as an essential component. Examples of the charge generation material that can be used in the present invention include inorganic materials and organic materials.
Examples of the inorganic material include selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, and α-silicon.
On the other hand, examples of organic materials include C-Iigment Blue 25 (Color Index CI 21180), C-Iigment Red 41 (CI 21200), C-I Acid Red 52 (CI 45100), C-I Basic Red 3 (CI 45210), and carbazole skeleton. Azo pigments having a distyrylbenzene skeleton (for example, described in JP 53-133445), azo pigments having a triphenylamine skeleton (for example, described in JP-A-53-95033) Examples thereof include those described in JP-A No. 53-132347), azo pigments having a dibenzothiophene skeleton (for example, described in JP-A No. 54-21728), and azo pigments having an oxadiazole skeleton (for example, JP-A No. 54-12742), An azo pigment having a fluorenone skeleton (for example, described in JP-A No. 54-22834), an azo pigment having a bis-stilbene skeleton (for example, described in JP-A No. 54-17733), a distyryloxadiazole skeleton Azo pigments (for example, described in JP-A No. 54-2129), azo pigments having a distyrylcarbazole skeleton (for example, described in JP-A No. 54-14967), for example, CI Pigment Blue 16 (CI 74100), phthalocyanine pigments such as titanyl phthalocyanine, for example, indigo pigments such as C-Ivat Brown 5 (CI 73410), C-Ivat Die (CI 73030), Argo Scarlet B (manufactured by Bayer), Scarlet R (manufactured by Bayer) It includes Ren pigment. These pigments may be used alone or in combination of two or more.

  Further, among the above charge generating materials, a highly sensitive and highly durable photoconductor can be obtained particularly by a combination with a phthalocyanine pigment. Examples of the phthalocyanine pigment include compounds having a phthalocyanine skeleton represented by the following general formula (N). Examples of M (center metal) in the formula include metal and metal-free (hydrogen) elements.

  Specific examples of M (central metal) include H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., or oxide, chloride And those composed of two or more elements such as fluoride, fluoride, hydroxide and bromide. The central metal is not limited to these elements.

  The charge generation material having a phthalocyanine skeleton in the present invention may have at least the basic skeleton of the above general formula (N), a substance having a multimeric structure such as a dimer or trimer, and a higher order It may have a polymer structure. Also, the basic skeleton may have various substituents.

Of these various phthalocyanines, oxotitanium phthalocyanine having TiO as the central metal, hydroxygallium phthalocyanine having GaOH, and metal-free phthalocyanine having H are particularly preferable in terms of photoreceptor characteristics.
That is, phthalocyanine is also known to have various crystal systems, such as α, β, γ, m, Y type in the case of oxotitanium phthalocyanine, α, β, γ, etc. in the case of copper phthalocyanine. It has a polycrystal system. Even in a phthalocyanine having the same central metal, various properties change as the crystal system changes. Among them, it has been reported that the characteristics of the photoreceptor also change with such a crystal system change (Electrophotographic Society Journal Vol. 29, No. 4 (1990)). For this reason, each phthalocyanine has an optimum crystal system in terms of the characteristics of the photoreceptor, and in particular for oxotitanium phthalocyanine, a Y-type crystal system is desirable.

In addition, these charge generation materials may be a mixture of two or more charge generation materials having a phthalocyanine skeleton. Further, it may be mixed with other charge generating materials.
These pigments may be used alone or in combination of two or more. The amount of these charge generation materials in the photosensitive layer is 0.1 to 40% by weight, preferably 0.3 to 20% by weight, and the ratio of the charge generation material to the polymer hole transport material is 2 to 60% by weight. % Is preferable.

Moreover, in the photosensitive layer of this embodiment, a low molecular hole transport material can be added as needed for the purpose of improving charging property and sensitivity.
Examples of the low molecular hole transport material used in the present embodiment include oxazole derivatives, oxadiazole derivatives (for example, described in JP-A Nos. 52-139065 and 52-139066), imidazole derivatives, triphenylamine. Derivatives (for example, described in JP-A-3-285960), benzidine derivatives (for example, described in JP-B-58-32372), α-phenylstilbene derivatives (for example, described in JP-A-57-73075) Hydrazone derivatives (described in, for example, JP-A-55-154955, JP-A-55-156955, JP-A-55-52063, JP-A-56-81850), triphenylmethane derivatives (for example, JP-B-5-10983). Anthracene derivatives (for example, JP-A-51-94829) ), Styryl derivatives (for example, described in JP-A-56-29245 and JP-A-58-198043), carbazole derivatives (for example, described in JP-A-58-58552), pyrene derivatives (for example, special No. 2-94812) is used.

  If necessary, additives such as a plasticizer, an antioxidant, a light stabilizer, a heat stabilizer and a lubricant can be added to the photosensitive layer for the purpose of improving the charging property. Such plasticizers are halogenated paraffin, dimethylnaphthalene and dibutyl phthalate, and antioxidants and light stabilizers are phenol compounds, hydroquinone compounds, hindered phenol compounds, hindered amine compounds, hindered amines and hindered phenols in the same molecule. Existing compounds can be exemplified.

  In the present invention, the conductive support of the photosensitive member (hereinafter sometimes referred to as “conductive substrate”) is a metal plate such as aluminum, nickel, copper, titanium, gold, and stainless steel, a metal drum, or a metal. Examples thereof include a plastic film deposited with foil, aluminum, nickel, copper, titanium, gold, tin oxide, indium oxide, or the like, paper coated with a conductive material, a plastic film, or a drum.

  Furthermore, an intermediate layer may be provided on the conductive substrate as necessary. The intermediate layer generally contains a resin as a main component. However, considering that the photosensitive layer is coated with a solvent on these resins, it is desirable that the resin be a resin having a high solvent resistance with respect to a general organic solvent.

  Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, phenol resins, alkyd-melamine resins, Examples thereof include curable resins that form a three-dimensional network structure such as epoxy resins.

  A metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the intermediate layer to prevent moire and reduce residual potential. These intermediate layers can be formed by using an appropriate solvent and coating method like the above-mentioned photosensitive layer.

Furthermore, as the intermediate layer of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used. In addition, an anodized Al ₂ O ₃ material, an organic material such as polyparaxylylene (parylene), or an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, or CeO ₂ is used for the vacuum thin film preparation method. Can be used well. The thickness of the intermediate layer is suitably from 0 to 5 μm.

Further, a protective layer may be provided on the photosensitive layer in order to improve mechanical durability such as friction resistance.
Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer resin, chlorinated polyether resin, allyl resin, phenol resin, polyacetal resin, polyamide resin, polyamideimide resin, polyacrylate resin , Polyallylsulfone resin, polybutylene resin, polybutylene terephthalate resin, polycarbonate resin, polyethersulfone resin, polyethylene resin, polyethylene terephthalate resin, polyimide resin, acrylic resin, polypropylene resin, polyphenylene oxide resin, polysulfone resin, polystyrene resin, AS resin Butadiene-styrene copolymer resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, epoxy resin and the like.

  For the purpose of improving wear resistance, the protective layer is added with fluororesin such as polytetrafluoroethylene, silicone resin, and those in which inorganic materials such as titanium oxide, tin oxide and potassium titanate are dispersed. can do.

  As a method for forming the protective layer, a normal coating method can be employed. In addition, about 0.1-10 micrometers is suitable for the thickness of a protective layer. In addition to the above, known materials such as a-C and a-SiC formed by a vacuum thin film manufacturing method can also be used as the protective layer.

  The photosensitive layer in the photoreceptor of the present invention is prepared by dissolving or dispersing the material of the previous period in an organic solvent to prepare a photosensitive layer forming solution, which is immersed on the conductive support or via an intermediate layer. It is formed by coating with a blade coating method or spray coating method and then drying. If necessary, the charge generation material can be dispersed in advance, and this and other material components can be dissolved or dispersed together to prepare a photosensitive layer forming solution. Examples of the dispersion method include ball mill dispersion, ultrasonic dispersion, and homomixer dispersion.

  The thickness of the photosensitive layer in this embodiment is 5 to 100 μm, preferably 10 to 40 μm. If the thickness is less than 5 μm, the chargeability is lowered. Conversely, if the thickness is more than 100 μm, the sensitivity is lowered.

  Examples of the solvent used for preparing the dispersion or solution of the photosensitive layer include N, N-dimethylformamide, toluene, xylene, monochlorobenzene, 1,2-dichloroethane, 1,1,1-trichloroethane, dichloromethane, Examples include 1,1,2-trichloroethane, trichloroethylene, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, dioxane, dioxolane and the like.

  In the photosensitive layer according to the invention, a binder can be added as necessary for the purpose of improving the chargeability, sensitivity, dispersibility and the like. Any material can be used as the binder used for forming the photosensitive layer as long as it is a conventionally known binder for electrophotographic photoreceptors having good insulation properties, and is not particularly limited.

  For example, polyethylene resin, polyvinyl butyral resin, polyvinyl formal resin, polystyrene resin, phenoxy resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin Addition resins such as polycarbonate resins, polyamide resins, silicone resins, melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more of these resin repeating units, for example, In addition to insulating resins such as vinyl chloride-vinyl acetate copolymer, styrene-acrylic copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, polymer organic semiconductors such as poly-N-vinylcarbazole Can be mentioned. These binders can be used alone or as a mixture of two or more.

  The liquid developing electrophotographic apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram for explaining an electrophotographic apparatus of a wet development type equipped with an electrophotographic photosensitive member according to the present invention. Note that the following modifications also belong to the category of the present invention.

  In FIG. 1, a liquid developing electrophotographic apparatus (electrophotographic apparatus) 11 includes a liquid developing electrophotographic photosensitive member (photosensitive drum) 10 on which an electrostatic latent image is formed, and charging means for performing a charging process on the photosensitive drum 10. (Charging Charger) 1, Image exposure means (exposure part) 3 such as laser beam, developing means 4 (developing roller 4a, squeeze roller 4b) for attaching toner to the electrostatic latent image on the photosensitive drum 10, photosensitive drum 10 From the transfer means (transfer charger) 6 for transferring the toner image on the recording paper P, and the cleaning means 8 (cleaning roller 8a, cleaning blade 8b, static elimination lamp 9, etc.) for cleaning the photosensitive drum 10 after the transfer processing. It is configured.

The photosensitive drum 10 in FIG. 1 contains a polymer charge transport material, a charge generation material, and an acceptor compound represented by the general formula (1) on a conductive support directly or via an intermediate layer. A single photosensitive layer is provided. 1 has a drum shape, it may be a sheet or an endless belt.
For the charging charger 1 and the transfer charger 6, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. In FIG. 1, reference numeral 2 is an erase, 7 is a separator, and 5 is a turn belt.

Light sources such as the image exposure means (exposure unit) 3 and the charge removal lamp 9 include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescences (ELs), etc. All of the luminescent materials can be used.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. Such a light source or the like irradiates the photosensitive member with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation in addition to the process shown in FIG.

  The toner developed on the photosensitive drum 10 by the developing unit 4 having the developing unit configuration is transferred to the transfer paper P, but not all is transferred, and toner remaining on the photosensitive member is also generated. Such toner is removed from the photoreceptor by a fur brush and a blade (cleaning roller 8a and cleaning blade 8b). Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

  When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (detection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

  The electrophotographic apparatus having the photoreceptor of the present invention prevents cracking of the photosensitive layer and elution of the constituent components of the photosensitive layer even when contacted with a carrier solvent. Therefore, high quality image formation can be performed stably.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not restrict | limited by these Examples.
Example 1
First, a polyamide resin (CM-8000: manufactured by Toray Industries, Inc.) solution dissolved in a methanol / butanol mixed solvent is applied onto an aluminum plate support with a doctor blade, and dried at 100 ° C. for 5 minutes to form a 0.5 μm intermediate layer. Provided.
Next, 0.5 g of X-type metal-free phthalocyanine was added to 0.5 g of a polymer charge transporting material (Exemplary Compound D-08 in Table 2: polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography = 229,000) After ball milling dispersion with a solution comprising 19 g of tetrahydrofuran, the pigment composition was 2.5% by weight, the polymer charge transport material (Exemplary Compound D-08) was 75% by weight, and the acceptor compound (Exemplary Compound A-1) 22 mentioned above. Polymer charge transport material, acceptor compound, tetrahydrofuran, and silicone oil were added so that the content would be 0.005% by weight, silicone oil (KF50: manufactured by Shin-Etsu Chemical Co., Ltd.), and a photoconductor having a solid content of 20% by weight. A coating solution was prepared. The thus prepared photoreceptor coating solution was applied onto the intermediate layer with a doctor blade, dried at 120 ° C. for 20 minutes, and a single-layer electrophotographic photoreceptor (No. 1) having a 20 μm-thick photosensitive layer. )created.

(Example 2)
The polymer charge transporting material (Exemplary Compound D-08 in Table 2) used in Example 1 was replaced with Exemplified Compound D-09 in Table 2 (weight average molecular weight in terms of polystyrene measured by gel permeation chromatography = 173,900). A single-layer electrophotographic photosensitive member (No. 2) was prepared under the same conditions as in Example 1 except that the above was replaced.

(Example 3)
0.5 g of X-type metal-free phthalocyanine was converted into a polymer charge transporting material (Exemplary Compound D-11 in Table 3: k = 0.663, j = 0.237, polystyrene-reduced weight average molecular weight measured by gel permeation chromatography) = 188,800) After ball milling and dispersing with a solution of 0.5 g and tetrahydrofuran 19 g, pigment composition 2.5 wt%, polymer charge transport material (Exemplary Compound D-11) 77.5 wt%, (Exemplary Compound) A-1) An acceptor compound represented by 20% by weight and a silicone oil (KF50: manufactured by Shin-Etsu Chemical Co., Ltd.) of 0.001% by weight were charged with a polymer charge transport material, an acceptor compound, tetrahydrofuran, and silicone oil. In addition, a photoreceptor coating solution having a solid content of 20% by weight was prepared. The thus prepared photoreceptor coating solution was applied to the intermediate layer prepared in the same manner as in Example 1 with a doctor blade, dried at 120 ° C. for 20 minutes, and a single-layer type electron having a photosensitive layer with a thickness of 20 μm. A photographic photoreceptor (No. 3) was prepared.

Example 4
The polymer charge transport material (Exemplary Compound D-11 in Table 3) used in Example 3 was measured by Exemplified Compound D-03 in Table 1 (k = 0.316, j = 0.684, gel permeation chromatography). A single-layer electrophotographic photosensitive member (No. 4) was prepared under the same conditions as in Example 3 except that the weight average molecular weight in terms of polystyrene was 95,300).

(Example 5)
The polymer charge transport material (Exemplary Compound D-11 in Table 3) used in Example 3 was measured by Exemplified Compound D-10 in Table 2 (k = 0.51, j = 0.49, gel permeation chromatography). A single layer type electrophotographic photosensitive member (No. 5) was prepared under the same conditions as in Example 3 except that the weight average molecular weight in terms of polystyrene was changed to 143,100).

(Example 6)
The polymer charge transport material (Exemplary Compound D-11 in Table 3) used in Example 3 was measured by Exemplified Compound D-14 in Table 3 (k = 0.56, j = 0.44, gel permeation chromatography). A single-layer electrophotographic photoreceptor (No. 6) was prepared under the same conditions as in Example 3 except that the weight average molecular weight in terms of polystyrene was 190,000).

(Example 7)
In Example 3, the pigment composition was 2.5% by weight, the polymer charge transporting substance (Exemplary Compound D-12 in Table 3: k = 0.76, j = 0.24, in terms of polystyrene measured by gel permeation chromatography). Weight average molecular weight = 150,000) 75% by weight, acceptor compound (Exemplary Compound A-1) 20% by weight, phenolic compound (No. G2 in specific examples) 2.5% by weight, silicone oil (KF50: Shin-Etsu) (Manufactured by Chemical Co., Ltd.) A polymer charge transporting substance, an acceptor compound, a phenolic compound, tetrahydrofuran, and silicone oil were added so as to be 0.001% by weight to prepare a photoreceptor coating solution having a solid concentration of 20% by weight. A single-layer electrophotographic photosensitive member (No. 7) was prepared in the same manner as in Example 3 except for the above.

(Example 8)
In Example 3, the pigment composition was 2.5% by weight, the polymer charge transporting substance (Exemplary Compound D-13 in Table 3: k = 0.74, j = 0.26, in terms of polystyrene measured by gel permeation chromatography). Weight average molecular weight = 147,000) 75% by weight, acceptor compound (Exemplary Compound A-1) 20% by weight, antioxidant (Sankyo LS2626) 2.5% by weight, silicone oil (KF50: Shin-Etsu Chemical Co., Ltd.) (Manufactured) except that a polymer charge transporting substance, an acceptor compound, an antioxidant, tetrahydrofuran, and silicone oil were added so as to be 0.001% by weight, and a photoreceptor coating solution having a solid content concentration of 20% by weight was prepared. A single layer type electrophotographic photosensitive member (No. 8) was prepared in the same manner as in Example 3.

(Comparative Example 1)
A polyamide resin (CM-8000: manufactured by Toray Industries, Inc.) solution dissolved in a methanol / butanol mixed solvent was applied on an aluminum plate support with a doctor blade, and dried at 100 ° C. for 5 minutes to provide a 0.5 μm intermediate layer. . Next, 0.5 g of X-type metal-free phthalocyanine was dispersed by ball milling together with a solution of 0.5 g of polycarbonate Z (PC-Z, manufactured by Teijin Chemicals) and 19 g of tetrahydrofuran, and then 2% by weight of pigment composition and PC-Z composition Is 50% by weight, 30% by weight of a low molecular charge transfer substance represented by the following structural formula (T-1), 18% by weight of an acceptor compound represented by (A-1), silicone oil (KF50: Shin-Etsu Chemical) A low molecular charge transport material, an acceptor compound, tetrahydrofuran, and silicone oil were added so as to be 0.001% by weight, to prepare a photoreceptor coating solution having a solid content of 20% by weight. The thus prepared photoreceptor coating solution was applied onto the intermediate layer with a doctor blade, dried at 120 ° C. for 20 minutes, and a single-layer electrophotographic photoreceptor (No. 9) having a 20 μm-thick photosensitive layer. )created.

Using the single layer type electrophotographic photosensitive member of the above Examples (1) to (8) and Comparative Example (1), the change in appearance of the photosensitive member after immersion in a carrier solvent and the photosensitive member characteristics were measured under the following measurement conditions. It was evaluated by. The results are shown in Tables 4 to 12 below.
<Test conditions for appearance change and photoreceptor characteristics>
Appearance change:
The test pieces (55 mm × 60 mm: subjected to end face treatment) of the single-layer type electrophotographic photosensitive member produced in the above examples and comparative examples were used as carrier solvent ISOPAR (manufactured by Exxon Chemicals) for liquid development, and silicone oil ( It was immersed in the dark of 20 ° C. and humidity of 50% in Toray Dow Silicone SH200; 50 cSt). Initially and after the end of each period, the appearance change of the photoreceptor (visual observation of presence of discoloration, presence of cracks, etc.) was evaluated.
Photoreceptor characteristics:
As for the characteristics of the photoconductor, an electrostatic copying paper test apparatus EPA-8200 (manufactured by Kawaguchi Electric Manufacturing Co., Ltd.) is used in an environment of 25 ° C./55% RH. The surface potential V0 (V) after being allowed to stand is measured, and then a monochromatic light of 700 nm is irradiated so that the illuminance on the surface of the photoreceptor becomes 2.5 μW / cm ^2, and the surface potential of the photoreceptor becomes 800 V to 400 V. The half-exposure amount Em1 / 2 (μJ / cm ² ) required until this time was measured.

From Table 1 above, according to the electrophotographic photosensitive member having the constitution of the present invention, no discoloration or cracking is observed even after being immersed in any carrier solvent (Isopar, silicone oil) for a long time. And there is no change in electrophotographic characteristics. That is, the electrophotographic photosensitive member of the present invention has high resistance to a carrier solvent, high sensitivity, and excellent electrophotographic characteristics.
On the other hand, in the case of the comparative example, the appearance change was particularly severe in the immersion of Isopar, and discoloration occurred from the immersion for 1 day, and the electrophotographic characteristics could not be measured in 7 days. In the case of silicone oil, the deterioration was somewhat delayed, but on the 50th, discoloration of the appearance became remarkable, and the electrophotographic characteristics were greatly changed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram for explaining a wet development type electrophotographic apparatus including an electrophotographic photosensitive member according to the present invention.

Explanation of symbols

1 Charging means (charging charger)
2 Erase 3 Image exposure means (exposure section)
4 Developing means 4a Developing roller 4b Squeeze roller 5 Turn belt 6 Transfer means (transfer charger)
7 Separator roller 8 Cleaning means 8a Cleaning roller 8b Cleaning blade 9 Static elimination lamp 10 Electrophotographic photosensitive member for liquid development (photosensitive drum)
11 Liquid development electrophotographic apparatus (electrophotographic apparatus)
P Recording paper

Claims (7)

In an electrophotographic photoreceptor for liquid development used in an image forming apparatus of a wet development type,
The photoreceptor includes a simple substance containing at least a polymer charge transporting material represented by the following general formula (1), a charge generating material, and an acceptor compound on a conductive support directly or via an intermediate layer. An electrophotographic photoreceptor for liquid development, comprising a photosensitive layer.

{In Formula (1), Ar ₁ , Ar ₂ , Ar ₄ , and Ar ₅ represent a substituted or unsubstituted arylene group, and Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group or —O—. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. } 2. The electrophotographic photoreceptor for liquid development according to claim 1, wherein the polymer charge transport material is represented by the following general formula (2).

{In Formula (2), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. } 2. The electrophotographic photoreceptor for liquid development according to claim 1, wherein the polymer charge transport material is represented by the following general formula (3).

{In Formula (3), Ar ₃ represents a substituted or unsubstituted aryl group. Z represents an arylene group or —Ar ₆ —Za—Ar ₇ — (wherein Ar ₆ and Ar ₇ represent a substituted or unsubstituted arylene group, and Za represents O, S or an alkylene group). R ₁ and R ₂ represent a linear or branched alkylene group. h represents 0 or 1; k and j represent compositions, and 0.1 ≦ k ≦ 1 and 0 ≦ j ≦ 0.9. X represents a substituted or unsubstituted aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, a substituted or unsubstituted aromatic divalent group, or a divalent group formed by linking these, or the following general group Formula (A):

[Wherein, R ₁₁ and R ₁₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom, and l and m each represents an integer of 0 to 4. Y represents a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CO—O—. Z—O—CO— (wherein Z represents an aliphatic divalent group). The divalent group represented by this is represented.
Or the following general formula (B):

[Wherein, a represents an integer of 1 to 20, and b represents an integer of 1 to 2000. R ₂₁ and R ₂₂ represent a substituted or unsubstituted alkyl group or aryl group. The divalent group represented by this is represented. R ₁₁ and R ₁₂ , and R ₂₁ and R ₂₂ may be the same or different. }   The weight average molecular weight (polystyrene conversion) of the polymer charge transport material having the repeating unit represented by the general formula (1), the general formula (2) or the general formula (3) is 20000 in the measurement by the gel permeation chromatography method. The electrophotographic photoreceptor for liquid development according to any one of claims 1 to 3, wherein the photoreceptor is. 5. The electrophotographic photoreceptor for liquid development according to claim 1, wherein the acceptor compound is a 2,3-diphenylindene compound represented by the following general formula (F1).

(Wherein, f ₁ , f ₂ , f ₃ , and f ₄ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, or a nitro group, and A and B are a hydrogen atom, substituted or unsubstituted Represents a substituted aryl group, a cyano group, an alkoxycarbonyl group, or an aryloxycarbonyl group.) The electrophotographic photoreceptor for liquid development according to any one of claims 1 to 5, wherein the photosensitive layer contains at least one phenol compound represented by the following general formula (G1).

(Wherein g _{1 to} g ₈ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkoxy group.) 7. A liquid developing electrophotographic apparatus comprising: the liquid developing electrophotographic photosensitive member according to claim 1; and a charging unit, an image exposing unit, a developing unit, a cleaning unit, and a transfer unit.

Images