JP2714907B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member.

[0002]

2. Description of the Related Art In the electrophotographic copying machine of the Carlson method, after uniformly charging the surface of a photoreceptor, the charge is erased imagewise by exposure to form an electrostatic latent image, and the electrostatic latent image is formed. Is developed with toner, and then the toner image is transferred and fixed on paper or the like.

On the other hand, the photoreceptor is subjected to removal of adhered toner, charge removal, and surface cleaning, and is repeatedly used for a long time.

Accordingly, the electrophotographic photoreceptor has not only electrophotographic characteristics such as good charging characteristics and sensitivity and low dark decay, but also printing durability and abrasion resistance in repeated use.
Good physical properties such as moisture resistance, and resistance to ozone generated during corona discharge and ultraviolet light during exposure (environmental resistance) are also required. Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor containing an inorganic photoconductive substance such as selenium, zinc oxide, and cadmium sulfide as a main component of a photosensitive layer has been widely used.

On the other hand, the use of various organic photoconductive substances as materials for photosensitive layers of electrophotographic photosensitive members has been actively developed and studied in recent years.

For example, Japanese Patent Publication No. Sho 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitro-9-fluorenone. However, this photoreceptor is not always satisfactory in sensitivity and durability. In order to improve such drawbacks, an attempt has been made to develop an organic photoreceptor having high sensitivity and high durability by separately assigning a charge generation function and a charge transport function to different substances in the photosensitive layer. I have. In such a so-called function-separated type electrophotographic photoreceptor, since a material exhibiting each function can be selected from a wide range, an electrophotographic photoreceptor having arbitrary characteristics can be relatively easily produced. It is possible.

An electrophotographic photoreceptor having excellent electrophotographic properties and film strength can be obtained by using a low molecular weight organic compound as a charge transporting substance and using a substance capable of generating an arbitrary charge and a polymer binder in combination. Efforts are being made.

As the polymer binder, charging characteristics,
Polycarbonate is excellent in terms of repetition characteristics and the like, and among them, polycarbonate having bis-phenol A as a main repeating unit is typical. The structural formula is shown below.

[0009]

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(The polycarbonate having the above structural unit is hereinafter referred to as a BPA type.)
Bisphenol A has a structure in which two methyl groups are symmetrically bonded to a central carbon atom. However, as a result of the investigation, it has been found that the polycarbonate has the following disadvantages.

(1) The mechanical strength, particularly the scratch resistance and abrasion resistance, are insufficient, and it is difficult to increase the durability of the organic photoreceptor.

(2) Poor compatibility with the charge transport material (CTM), apt to cause crystal precipitation of CTM, and cause cracks and the like in the coating film.

[0013] (3) When performing the dip coating or the like using a high concentration of the coating liquid, easy coating liquid gelled.

(4) The photosensitive layer has disadvantages such as special mention of a gel substance on the surface, toner filming at the time of cleaning, and easy occurrence of image defects.

Therefore, for example, JP-A-60-172044 and JP-A-60-172045 disclose polycarbonates having a bulky substituent or polycarbonates having a ring at a central carbon atom (ZZ) as amorphous polycarbonates. Type) was proposed. By using the polycarbonate having a bulky substituent and the Z-type polycarbonate as a binder for the photosensitive layer, the drawback caused in the case of the BPA-type polycarbonate is improved. However, since the photoreceptor is fatigued and deteriorated by ozone generated by corona discharge and other active species generated at the time of image exposure, the repetitive characteristics of long-term image formation are insufficient. Therefore, for example, JP-A-1-118137, JP-A-1-118138 and JP-A-1-118137
JP-A-118139 discloses a polycarbonate having a bulky substituent or a polycarbonate of A type, Z type or the like, or a polycarbonate obtained by copolymerizing a structural unit of such a polycarbonate, with a hindered phenol structural unit and / or a hindered amine structural unit. It has been proposed to include an antioxidant consisting of a compound having the formula:

However, with the spread of copiers and the like, further improvement in image quality and high-speed copying are demanded, and in particular, high durability of the electrophotographic photosensitive member is required. Cannot respond to such a request,
For example, its durability is remarkably poor as compared with a photoreceptor such as selenium. As a result of intensive studies, the present inventors have found that improvement of the binder resin is indispensable in order to solve the above problems, and have completed the present invention.

[0017]

OBJECTS OF THE INVENTION It is an object of the present invention to provide film forming properties, mechanical strength,
An object of the present invention is to provide an electrophotographic photoreceptor having excellent abrasion resistance, high sensitivity and excellent long-term repetition characteristics.

[0018]

The object of the present invention is to provide an electrophotographic photoreceptor having a photosensitive layer containing a charge generating substance, a charge transporting substance and a binder resin on a conductive substrate. A copolymer containing a structural unit represented by [B ₁ ] and a structural unit represented by the following general formula [B ₂ ] as a main component, and a hindered phenol structural unit and / or a hindered amine structural unit. This is achieved by an electrophotographic photoreceptor characterized by containing a compound having a molecule.

[0019]

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In the formula, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group (for example, a phenyl group or a naphthyl group), and R ₁ and R 2 Represents a C _{4 to} C ₁₀ cyclic hydrocarbon residue formed by ₂ ;

R ₃ , R ₄ , R ₅ and R ₆ are each a hydrogen atom,
Halogen atom (e.g., chlorine, a bromine, iodine atoms arsenide) represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group (e.g. phenyl, naphthyl) and. l, m, p, and q are integers of 1 to 4.

A preferred embodiment is an electrophotographic photosensitive member containing a copolymer compound in which the repeating structural units of the above general formulas [B ₁ ] and [B ₂ ] are as follows.

[0023]

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The degree of polymerization of the copolymer of the present invention is 10 to 500.
0, preferably 50-1000. In the present invention, the above general formula [B
₁ ) and a copolymer containing the general formula [B ₂ ] in the structural composition are used as a binder resin to provide excellent film physical properties, excellent electrophotographic properties such as charge holding power, sensitivity residual potential, and the like, and have been repeatedly used. An electrophotographic photoreceptor exhibiting stable characteristics with little fatigue deterioration at times can be produced.

Further, if necessary, other binders can be mixed and used within a range that does not hinder the intended operation and effect. The mixing ratio at this time is preferably 50 wt /% or less.

The copolymer compound of the present invention comprises the following (I) and
It is easily synthesized according to a conventional method using a phenolic compound selected from (II).

[0027]

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Where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ ,
l, m, p and q are the same as those represented by the general formulas [B ₁ ] and [B ₂ ].

Specifically, the method for producing the copolymer compound of the present invention is carried out in the presence of an inert solvent such as methylene chloride, 1,2-dichloroethane or the like, by adding the above-mentioned phenol compound to an aqueous alkali solution or an acid acceptor as an acid acceptor. There is a method in which pyridine or the like is added and the reaction is carried out while introducing phosgene.

When an aqueous alkaline solution is used as the acid acceptor, the reaction rate is increased if a tertiary amine such as trimethylamine or triethylamine or a quaternary ammonium compound such as tetrabutylammonium chloride or benzyltributylammonium bromide is used as a catalyst. Increase.

If necessary, a monovalent phenol such as phenol or pt-butylphenol may be used as a molecular weight regulator. The catalyst may be added from the beginning, or any method may be employed, such as adding the catalyst after producing the oligomer to increase the molecular weight.

In the present invention, the method of copolymerizing using two or more phenolic compounds includes: (a) a method of simultaneously reacting two or more phenolic compounds with phosgene first and copolymerizing them. ) One of them is first reacted with phosgene, and after a certain degree of reaction, the other is added and polymerized.

Next, specific examples of the structures represented by the general formulas [B ₁ ] and [B ₂ ] will be given, but the present invention is not limited to these.

[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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The following are examples of the copolymer compound having both structures, but the present invention is not limited thereto.

[0041]

[Table 1]

In the above table, the ratio of x and y in the copolymer compound (copolymerization ratio) is in the range of x: y = 95: 5 to 5:95, more preferably 95: 5 to 50:50. Range.

When the ratio of y is 50 mol % or more, the sensitivity and the mechanical strength decrease.
It is preferred to be 50 mol % or less.

Examples of the binder which may be used in combination with the copolymer compound of the present invention used as the above-mentioned binder include the following.

(1) Polyester (2) Methacrylic resin (3) Acrylic resin (4) Polyvinyl chloride (5) Polyvinylidene chloride (6) Polystyrene (7) Polyvinyl acetate (8) Styrene copolymer resin (for example, styrene- (9) acrylonitrile copolymer resin (for example, vinylidene chloride-acrylonitrile copolymer, etc.) (10) vinyl chloride-vinyl acetate copolymer (11) Vinyl chloride-vinyl acetate-maleic anhydride copolymer (12) Silicone resin (13) Silicone-alkyd resin (14) Phenol resin (for example, phenol-formaldehyde resin, cresol-formaldehyde resin, etc.) (15) Styrene-alkyd resin (16) Poly-N-vinyl carbazole (17) Polyvinyl butyral (18) Polyvinyl formal Le (19) polyhydroxystyrene These binders may be used together in a co-critical condition compounds according to the present invention alone or as a mixture of two or more.

Next, the compound having a hindered phenol structural unit in a molecule used in the present invention will be described. The compound is represented by the following general formula [1]
A], general formula [2A], general formula [3A], general formula [4
A] and those represented by the general formula [5A].

[0047]

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[In the general formula [1A], R ¹³ is a branched alkyl group, R ¹⁴ , R ¹⁵ and R ¹⁶ are a hydrogen atom or a hydroxy group,
Represents an alkyl group or an aryl group, and R ¹⁵ and R ¹⁶ may be mutually connected to form a ring. R ¹⁷ represents a hydrogen atom, an alkyl group or an alkylidene group.

R ¹³ is tert- or s-C 3-40.
An ec-alkyl group is preferred.

The alkyl groups of R ¹⁴ , R ¹⁵ and R ¹⁶ preferably have 1 to 40 carbon atoms, and the aryl groups include phenyl, naphthyl and pyridyl groups.

When R ¹⁵ and R ¹⁶ are rings, a chroman ring is preferred.

The alkyl group and alkylidene group represented by R ¹⁷ preferably have 1 to 40 carbon atoms, and particularly preferably have 1 to 18 carbon atoms.

Y ¹ is a hydrogen atom or an organic residue, preferably an organic residue. [In the general formula [2A], R ¹⁸ is a hydrogen atom or an alkyl group, an aryl group, an aralkyl group, R ¹⁹ ,
R ²³ is a branched alkyl group, R ²⁰ , R ²¹ , R ²² and R ²⁴ ,
R ²⁵ and R ²⁶ represent a hydrogen atom or a substituent.

M and p are 0 or a positive integer, and m + p
Is 2-4. W is a communication group.

The alkyl group represented by R ¹⁸ is an alkyl group having 1 to 40 carbon atoms and may have a substituent. As the substituent for R ^18, any one of an aryl group, an alkoxy group, a carboxyl group, an amide group, a halogen atom and the like can be used.

As the aralkyl group, a benzyl group,
And a phenethyl group.

The branched alkyl group represented by R ¹⁹ and R ²³ is a branched alkyl group having 1 to 40 carbon atoms, such as (t) butyl, (sec) butyl, (sec) octyl, (t) An octyl group;

Examples of the substituent which R ^{20 to} R ²² and R ^{24 to} R ²⁶ can have include an aryl group, an alkoxy group, a carboxyl group, an amide group, a halogen atom and the like.

The linking group W changes depending on the values of m and p. Typical examples of W include a methylene group, an ethylene group, a propylene group, a phenylene group, a sulfide and a polysulfide group.

The above also includes the case where phenyl groups are directly bonded to each other without W. ] [General formula [3
A] wherein R ²⁷ , R ²⁸ and R ^{29 have} 1 to 1 carbon atoms
The alkyl group of 4 may be linear or branched, and specific examples include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a sec-butyl group, and a t-butyl group. .

Of these groups, a t-butyl group is particularly preferred. R ²⁷ , R ²⁸ and R ²⁹ may be the same or different. [In the general formula [4A], R ³⁰ and R ³¹ each represent an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and R ³² , R ³³ , R ³⁴ and R ³⁵ each represent Hydrogen atom, halogen atom, alkyl group, alkenyl group, cycloalkyl group, aryl group, alkoxy group, alkylthio group, aryloxy group, arylthio group, acyl group, acylamino group, alkylamino group, alkoxycarbonyl group or sulfonamide group Represent. 〕〔or,
In the general formula [5A], R ³⁶ represents an alkyl group having 1 to 18 carbon atoms, and R ³⁷ and R ³⁸ each represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. R ³⁹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

Further, in the general formula [5A], R ³⁶ and R
³⁷ and alkyl groups having 1 to 18 carbon atoms represented by R ³⁸ represents may be linear or branched, such as methyl group, ethyl group, propyl group, i- butyl, t- butyl group, a pentyl group, an octyl group , Dodecyl group and the like.

The alkyl group having 1 to 10 carbon atoms represented by R ³⁹ may be straight-chain or branched, for example, methyl, ethyl, propyl, butyl, t-butyl, sec-pentyl, hexyl And a nonyl group. ]
Particularly important examples of the compounds having a hindered phenol structural unit between the molecules contained in the general formulas [1A] to [5A] are shown below.

[0064]

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Next, examples of other hindered phenol compounds will be described.

[0066]

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[0067]

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Further, as the compound having a hindered amine structural unit in a molecule used in the present invention, the following general formula [1B], general formula [2B], general formula [3B], general formula [4B], general formula [5B] And the general formula [6B].

[0069]

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[In the general formulas [1B] and [2B], R ¹³ and R ¹⁴ are alkyl groups which may have a substituent. However, one of R ¹³ and R ¹⁴ is a branched alkyl group.

R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are a hydrogen atom, an alkyl group or an aryl group, preferably having 1 to carbon atoms.
It may be 40 alkyl groups and have a substituent.

As the substituent for R ^{13 to} R ^18, any one of an aryl group, an alkoxy group, a carboxyl group, an amide group, a halogen atom and the like can be used.

Z is an atomic group necessary for constituting a nitrogen-containing alicyclic ring, and is preferably an atomic group constituting a 5- or 6-membered ring. Preferred ring structures include piperidine, piperazine, morpholine, pyrrolidine, imidazolidine, oxazolidine, thiazolidine, selenazolidine, pyrroline,
Examples of the ring include imidazoline, isoindoline, tetrahydroisoquinoline, tetrahydropyridine, dihydropyridine, dihydroisoquinoline, oxazoline, thiazoline, selenazoline, and pyrrole, and particularly preferred are piperidine, piperazine, and pyrrolidine.

Further, the pair of R ¹⁵ and R ¹⁶ and R ¹⁷ and R ¹⁸
One of each of the sets of Z
It may be incorporated in

Y ¹ is an organic residue, and Y ² and Y ³ are a hydrogen atom or an organic residue, preferably an organic residue. ]

[0076]

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Among the compounds having a hindered amine structural unit contained in the general formulas [1B] to [6B] in the molecule, particularly important examples are shown below.

[0078]

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[0079]

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[0080]

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Further, as the compound having a copolymer component of a hindered phenol structural unit and a hindered amine structural unit in the molecule used in the present invention, the following general formula [7]
B] and a hindered amine structural unit represented by the general formula [6]
There is a compound [C] comprising a copolymer of a hindered phenol structural unit represented by A].

[0082]

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[In the general formulas [7B] and [6A], R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ represent a hydrogen atom or an alkyl group or an aryl group, and Z represents a nitrogen-containing alicyclic ring. Represents an atomic group required for Also, in each set of R ¹³ and R ¹⁴ and each set of R ¹⁵ and R ¹⁶ , one of them may be incorporated into Z to provide a double bond.

Further, R ¹⁷ is a branched alkyl group, R ¹⁸ , R
¹⁹ and R ²⁰ are a hydrogen atom or a hydroxy group, an alkyl group,
Represents an aryl group, and R ¹⁹ and R ²⁰ may be mutually connected to form a ring. R ²¹ represents a hydrogen atom, an alkyl group or an alkylidene group.

The above R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are preferably an alkyl group having 1 to 40 carbon atoms, and the alkyl group may have a substituent. Groups, alkoxy groups, carboxyl groups, amide groups, halogen atoms and the like.

Z is an atomic group necessary for constituting a nitrogen-containing alicyclic ring, and is preferably an atomic group constituting a 5- or 6-membered ring.

Preferred ring structures include piperidine, piperazine, morpholine, pyrrolidine, imidazolidine,
Oxazolidine, thiazolidine, selenazolidine, pyrroline, imidazoline, isoindoline, tetrahydroisoquinoline, tetrahydropyridine, dihydropyridine, dihydroisoquinoline, oxazoline, thiazoline, selenazoline, pyrrole and the like, and particularly preferably piperidine, piperazine, morpholine and pyrrolidine. Each ring.

R ¹¹ is a tert- or s-carbon having 3 to 40 carbon atoms.
An ec-alkyl group is preferred.

R ¹⁸ , R ¹⁹ and R ²⁰ are preferably alkyl groups having 1 to 40 carbon atoms, and aryl groups include phenyl, naphthyl and pyridyl groups.

When R ¹⁹ and R ^{20 form a} ring, a chroman ring is preferred.

The alkyl group and alkylidene group represented by R ²¹ preferably have 1 to 40 carbon atoms, and particularly preferably have 1 to 18 carbon atoms. The general formula [7
Among the compounds [C] comprising a copolymer of the hindered amine structural unit contained in B] and the hindered phenol structural unit contained in the general formula [6A], examples of particularly important compounds include the following. .

[0092]

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[0093]

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[0094]

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Next, the charge transport material (CT) used in the present invention
M) will be described.

First, the charge transport material (CTM) represented by the general formula [T ₁ ] will be described.

[0097]

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In the formula, Ar ₁ and Ar ₂ represent an aliphatic group or an aromatic group, and Ar ₃ represents a phenylene group, and Ar ₁ and Ar ₃ may form a ring. R ₁₃ and R ₁₄ represent a hydrogen atom, an alkyl group, or an aromatic group, and R ₁₅ represents an alkyl group or an aryl group.

The aryl group includes a phenyl group, a naphthyl group,
Represents a condensed polycyclic ring, Ar ₁ , Ar ₂ , Ar ₃ , R ₁₃ , R ₁₄ , R ₁₅
In said aliphatic group and an aromatic to an alkyl group, an alkoxy group, a halogen atom, may contain a substituent group such as an amino group, a carbazole ring in Ar _1, Ar _2, a ring such as indoline ring And the ring formed by R ₁₄ and R ₁₅ is 5
A 7-membered carbocyclic or heterocyclic ring. The compound is CT
It has good performance as M and is convenient for increasing sensitivity.

Examples of the compound represented by the general formula [T] will be described below, but it should not be construed that the invention is limited thereto.

Specific examples of the compound of the formula [T ₁ ]:

[0102]

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[0103]

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[0104]

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[0105]

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[0106]

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[0107]

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Next, the charge transport material (CTM) represented by the general formula [T ₂ ] will be described.

[0109]

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[Wherein, Ar ₁ is a phenyl group substituted with (R ₃ ) i, _three substituted or unsubstituted groups; a condensed polycyclic hydrocarbon group, a heterocyclic group, a condensed polycyclic system Represents a heterocyclic group.

Ar ₂ and Ar _{3 each} represent a phenyl group substituted with (R ₄ ) j, the following _three substituted or unsubstituted groups; a condensed polycyclic hydrocarbon group, a heterocyclic group, a condensed polycyclic heterocyclic group. Represents a ring group.

Ar ₄ and Ar ₅ are a phenyl group substituted by (R ₅ ) k, the following three substituted or unsubstituted groups; a condensed polycyclic hydrocarbon group, a heterocyclic group, a condensed polycyclic system Represents a heterocyclic group.

R ₁ and R ₂ are a phenyl group substituted by (R ₆ ) l, the following three substituted or unsubstituted groups; a condensed polycyclic hydrocarbon group, a heterocyclic group, a condensed polycyclic system Represents a heterocyclic group, and may form a ring together with Ar ₄ and Ar ₅ . R ₃ is a substituted or unsubstituted alkyl group, phenyl group, alkoxy group, phenoxy group and cyano group, halogen atom, carboxyl group, acyl group, hydroxyl group, nitro group, amino group, and further substituted or unsubstituted 6 Group: represents an alkylamino group, an arylamino group, an aralkylamino group, a cyclic hydrocarbon group, a condensed polycyclic hydrocarbon group, or a heterocyclic group.

R ₄ , R ₅ and R ₆ are the following four substituted or unsubstituted groups: an alkyl group, a phenyl group, an alkoxy group, a phenoxy group and a cyano group, a halogen atom, a carboxyl group, an acyl group, and a hydroxyl group. , A nitro group, an amino group, and the following six groups further substituted or unsubstituted; an alkylamino group, an arylamino group, an aralkylamino group,
It represents a cyclic hydrocarbon group, a condensed polycyclic hydrogen group, or a heterocyclic group.

I, k, l represent integers from 0 to 5, and j is
Represents an integer of 0 to 4; The following are specific examples of the compound represented by the general formula [T ₂ ], but the present invention is not limited thereto.

[0116]

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[0117]

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[0118]

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[0119]

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[0120]

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[0121]

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[0122]

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The CTM which can be used in combination in the present invention is not particularly limited.
Bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives,
Acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene and the like.

As the CTM used in the present invention, those which are excellent in the ability to transport holes generated upon light irradiation and which are suitable for combination with the organic pigment used in the present invention are preferable. In the electrophotographic photoreceptor of the present invention, an organic pigment as shown in the following representative examples is used as a charge generation material (CGM).

(1) Azo pigments such as monoazo pigments, bisazo pigments, triazo pigments, metal complex salt azo pigments and the like (2) Perylene pigments such as perylene anhydride and perylene imide (3) Anthraquinone derivatives, anthantrone derivatives, dibenz Polycyclic quinone pigments such as pyrenequinone derivatives, pyranthrone derivatives, biolanthrone derivatives and isoviolanthrone derivatives (4) indigoid pigments such as indigo derivatives and thioindigo derivatives It is preferable to use an organic pigment such as a polycyclic quinone pigment, a perylene pigment, and a phthalocyanine pigment.

The fluorenone-based disazo pigment used in the present invention is represented by the following general formula [F ₁ ].

[0127]

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[Wherein X ₁ and X ₂ each represent a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, a hydroxy group or a substituted or unsubstituted amino group. p and q each represent an integer of 0, 1 or 2;
When p and q are 2, X ₁ and X ₂ may be the same or different groups.

[0129] A represents a group represented by the following general formula [F ₁ -1]. ]

[0130]

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[Wherein, Ar represents a fluorinated hydrocarbon group or an aromatic carbocyclic group having a substituent or an aromatic heterocyclic group.
Z represents a non-metallic atomic group necessary for forming a substituted or unsubstituted aromatic carbocyclic ring or a substituted or unsubstituted aromatic heterocyclic ring. M and n each represent an integer of 0, 1 or 2. However, m and n do not become 0 at the same time.

Specific examples of the fluorenone-based disazo pigment used in the present invention are shown below, but it should not be construed that the invention is limited thereto.

[0133]

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[0134]

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[0135]

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[0136]

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The fluorenone-based disazo pigment represented by the general formula [F ₁ ] used in the present invention can be easily synthesized by a known method, for example, by the method described in Japanese Patent Application No. Sho 62-304862.

Next, the perylene pigment used in the present invention is represented by the following general formulas [P ₁ ] and [P ₂ ].

[0139]

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[In the general formulas [P ₁ ] and [P ₂ ], Z is substituted,
A group of atoms necessary to form an unsubstituted aromatic ring. ]
Preferred examples of the aforementioned Z include, for example, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyridine ring, a pyrazole ring, and an anthraquinone ring.
Particularly preferred are a benzene ring and a naphthalene ring.

Z is a substituent such as alkyl, alkoxy, aryl, aryloxy, arylacyloxy, amino, carbamoyl, halogen, nitro, cyano and the like. These perylene compounds have a Bragg angle 2θ of 6.3 ° ± 0.2 °, 12.5 ° ± 0.2 °, 25.4 ° ± 0.2, 27.2 ± 0.
Those having a peak at 2 are preferred.

Specific examples of the compounds represented by formulas [P ₁ ] and [P ₂ ] are shown below, but the invention is not limited thereto.

[0143]

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The polycyclic quinone pigment used in the present invention is represented by the following general formulas [Q ₁ ] to [Q ₃ ].

[0145]

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[Wherein X is a halogen atom, a nitro group,
Represents a cyano group, an acyl group, or a carboxy group;
And m represents an integer of 0 to 6. Specific examples of the polycyclic quinone pigment represented by the general formulas [Q ₁ ] to [Q ₃ ] and used in the present invention are shown below, but are not limited thereto.

The following are specific examples of the anthantrone pigment represented by the general formula [Q ₁ ].

[0148]

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Specific examples of the dibenzpyrenequinone pigment represented by the general formula [Q ₂ ] are as follows.

[0150]

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[0151]

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Specific examples of the pyranthrone pigment represented by the general formula [Q ₃ ] are as follows.

[0153]

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The compounds represented by the above general formula [Q ₁ ] to be used in the present invention
The polycyclic quinone pigment represented by [Q ₃ ] can be easily synthesized by a known method.

As the metal-free phthalocyanine-based pigment that can be used in the present invention, all metal-free phthalocyanine having photoconductivity and derivatives thereof can be used.
Type, β type, τ, τ ′ type, η, η ′ type, X type, and JP-A-62
Crystal forms and derivatives thereof described in -103651 can be used. In particular, it is desirable to use the τ, X, K / RX type. X-type metal-free phthalocyanine is disclosed in US Pat.
No. 7,989, and τ-type metal-free phthalocyanine is described in JP-A-58-182639. As disclosed in Japanese Patent Application Laid-Open No. 62-103651, the K / R-X type has a CuKα, at a Bragg angle (2θ ± 0.2 degrees) with respect to an X-ray of 1.541 °.
It has major peaks at 7.7, 9.2, 16.8, 17.5, 22.4, and 28.8 degrees, and a peak intensity ratio of 16.8 degrees to a peak intensity of 9.2 degrees is 0.8 to 1.0, and a peak of 28.8 degrees to 22.4 degrees. A phthalocyanine having a strength ratio of 0.4 or more. The oxytitanyl phthalocyanine used in the present invention is represented by the following general formula [TP].

[0156]

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[Wherein X ₁ , X ₂ , X ₃ and X ₄ each independently represent H, Cl or Br, and n, m, l and k each independently represent 0
Represents a number from 4 to 4. Among the oxytitanyl phthalocyanines used in the present invention, particularly preferred ones are disclosed in
Oxytitanyl phthalocyanine (Y-Ti
OPc) titanyl chlorophthalocyanine (TiOPcCl) and mixtures thereof.

As these oxytitanyl phthalocyanines, those having different crystal types disclosed in the following patents are known. For example, JP-A-61-239248, 62-6709
No. 43, No. 62-272272, No. 63-116158 or No. 64-17066.

The dispersion medium of the organic pigment used in the present invention includes, for example, hydrocarbons such as hexane, benzene, toluene and xylene, methylene chloride, methylene bromide, 1,2-dichloroethane, syn-tetrachloroethane, cis -1,2-dichloroethylene, 1,1,2-trichloroethane, 1,1,1-trichloroethane, 1,2-dichloropropane,
Halogenated hydrocarbons such as chloroform, bromoform and chlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, methanol, ethanol, propanol, butanol, cyclohexanol and heptanol,
Alcohols such as ethylene glycol, methyl cellosolve, ethyl cellosolve, cellosolve acetate and derivatives thereof,
Ethers such as tetrahydrofuran, 1,4-dioxane, furan, and furfural; acetals; amines such as pyridine, butylamine, diethylamine, ethylenediamine, and isopropanolamine; nitrogen compounds such as amides such as N, N-dimethylformamide; and other fatty acids And phenols, sulfur such as carbon disulfide and triethyl phosphate, and phosphorus compounds.

In the present invention, the photosensitive layer may contain one or more kinds of electron-accepting substances for the purpose of improving sensitivity, reducing residual potential to fatigue during repeated use, and the like.

Examples of the electron-accepting substance that can be used here include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and 3-nitrophthalic anhydride. Acid, 4-nitrophthalic anhydride, pyromellitic anhydride,
Melitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, bulmanil, Dichlordicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone,
2,4,5,7-tetranitrofluorenone, 9-fluorenylidene [dicyanomethylenemalonodinitrile], polynitro-9
-Fluorenylidene- [dicyanomethylenemalonodinitrile], picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid,
Examples thereof include 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, melitic acid, and other compounds having a high electron affinity. The addition ratio of the electron-accepting substance is as follows: the organic pigment used in the present invention: electron-accepting substance = 100: 0.01 to 200, preferably 100: 0.1 to 1 in weight ratio.
00.

The addition ratio of the electron-accepting substance to such a layer is 100: 0.01 to 100, preferably 100: 0.1 to 50, in terms of weight ratio, of total CTM: electron-accepting substance.

Further, an organic amine can be added to the photosensitive layer of the present invention for the purpose of improving the charge generation function of CGM, and it is particularly preferable to add a secondary amine. These compounds are described in JP-A-59-218447 and JP-A-62-8160.

Further, the amount of the antioxidant of the present invention is CTM 10
The amount is 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, particularly preferably 1 to 25 parts by weight with respect to 0 parts by weight.

The photoreceptor of the present invention may further contain, if necessary, an ultraviolet absorber for the purpose of protecting the photosensitive layer, and may contain a dye for correcting color sensitivity.

In the electrophotographic photoreceptor of the present invention, an intermediate layer can be provided between the conductive substrate and the photosensitive layer, if necessary.

Further, the intermediate layer functions as an adhesive layer or a blocking layer, etc., in addition to the binder resin,
For example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, casein, N-alkoxymethylated nylon, starch and the like are used.

As the conductive support used in the construction of the electrophotographic photosensitive member of the present invention, the following are mainly used, but the present invention is not limited thereto. 1) Metal plate such as aluminum plate and stainless plate. 2) A thin metal layer made of aluminum, palladium, gold or the like provided on a support such as paper or plastic film by lamination or vapor deposition.

3) A substrate in which a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided by coating or vapor deposition on a support such as paper or a plastic film.

The photoreceptor of the present invention is shown in FIGS. 1 (1) and 1 (2).
As shown in the figure, a CGL containing CGM as a main component on the conductive support 1
2 and CTL containing CTM used in the present invention as a main component
3 is provided. As shown in FIGS. 3C and 3D, the photosensitive layer 4 is made of a conductive support 1
It may be provided via the intermediate layer 5 provided above. Thus, when the photosensitive layer 4 has a two-layer structure, an electrophotographic photosensitive member having the best electrophotographic characteristics can be obtained. In the present invention, as shown in FIGS. 5 and 6, the photosensitive layer 4 in which fine particles of CGM 7 are dispersed in the layer 6 containing CTM as a main component is used as the conductive support 1. Directly on or in the middle layer 5
May be provided.

Further, a protective layer 8 may be provided on the photosensitive layer 4 if necessary.

Here, when the photosensitive layer 4 has a two-layer structure, CG
Which of L2 and CTL 3 is to be the upper layer is determined by whether the charging polarity is selected to be positive or negative. That is, in the case of forming a negatively charged photosensitive layer, it is advantageous to use CTL3 as an upper layer, because CTM in the CTL3 is a substance having a high transport ability to holes.

The CGL 2 forming the photosensitive layer 4 having a two-layer structure
Can be formed by the following method directly on the conductive support 1 or the CTL 3 or, if necessary, after providing an intermediate layer such as an adhesive layer or a blocking layer.

(1) Vacuum evaporation method (2) Method of applying a solution in which CGM is dissolved in an appropriate solvent (3) CGM is made into fine particles in a dispersion medium by a ball mill, a sand grinder or the like, and a binder is used if necessary. And applying a dispersion obtained by mixing and dispersing.

That is, specifically, a vapor phase deposition method such as vacuum evaporation, sputtering, or CVD, or a coating method such as dipping, spray, blade, or roll method is optionally used.

The thickness of the CGL2 thus formed is
It is preferably from 0.01 μm to 5 μm, more preferably 0.05 μm
μm to 3 μm.

The thickness of the CTL 3 can be changed as required, but is usually preferably 5 μm to 30 μm. This CT
The composition ratio in L3 is preferably from 0.1 to 5 parts by weight of the binder to 1 part by weight of the CTM of the present invention. However, when the photosensitive layer 4 in which fine-grained CGM is dispersed is formed, CGM is preferably used.
It is preferable to use the binder in a range of 5 parts by weight or less with respect to 1 part by weight.

In the case where the CGL is of a dispersion type in a binder, the binder is added to 5 parts by weight of CGM.
It is preferable to use it in the range of not more than part by weight. The photoreceptor of the present invention has the above-described configuration, and has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, as will be apparent from the examples described later. In particular, even when subjected to a repetitive transfer type electrophotographic system, it has little fatigue deterioration and excellent durability.

[0179]

EXAMPLES The present invention will be described below in more detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 A polyamide resin C was placed on an aluminum drum having an outer diameter of 80 mmφ.
30 g of M-8000 (manufactured by Toray Industries, Inc.) was charged into a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol, and dissolved by heating at 50 ° C. After the temperature of the obtained solution was lowered to room temperature, it was dip-coated on the drum to form a 0.5 μm thick intermediate layer. Then polyvinyl butyral resin S-LEC B X -1 (manufactured by Sekisui Chemical Co., Ltd.)
5g was carried out for 20 hours dispersed using a sand mill after mixing the methyl ethyl ketone 1000ml dissolved charge generating material in _{(CGM) (Q 1 -3)} 10g. The obtained dispersion is dip-coated on the intermediate layer to form a 0.5 μm thick charge generation layer (CGL).
Was formed. Next, a charge transport material (CT)
M) ( T-24 ) 200g and antioxidant (phenolic AO
Agent) Exemplified ( [3A] -1 ) 5 g and copolymer compound ( B-
1 ) 200 g was dissolved in 1000 ml of dichloromethane, and the obtained solution was dip-coated on the CGL to form a charge transport layer (CTL) having a thickness of 20 μm, and dried by heating at 100 ° C. for 1 hour. A photoreceptor was obtained.

Examples 2 to 10 Example 2 was repeated in the same manner as in Example 1 except that the types of CGM, CTM, binder resin and AO agent were changed as shown in Table 2.
Nine types of electrophotographic photosensitive members for Example 10 were obtained. Comparative Examples 1 to 4 Four types of electrophotographic photosensitive members for Comparative Examples 1 to 4 were obtained in the same manner as in Example 1 except that the types of the binder resin and the AO agent were changed as shown in Table 3.

[0182]

[Table 2]

[0183]

[Table 3]

Example 11 Exemplified compound was formed on an intermediate layer formed in the same manner as in Example 1.
200g of ( T-24 ) as CTM and phenolic A
O agent ( [3A] -1 ) 10g and bisphenol A type polycarbonate, Panlite L-1250 (manufactured by Teijin Chemicals Ltd.)
200 g was dissolved in 1000 ml of dichloromethane, and the obtained solution was dip-coated on the intermediate layer to form a CTL having a thickness of 18 μm. Next, as binder resin ( B-1 ) 5g and CTM
( T-24 ) 3 g and the exemplified compound phenolic AO agent ( [3
A) -1 ) 0.5 g was dissolved in 1000 ml of solvent dichloroethane, and 3 g of CGM ( Q _1-3 ) was mixed, followed by dispersion using a sand mill for 20 hours. The obtained dispersion is subjected to the above-mentioned CTL.
A 3 μm thick CGL was formed by coating on the top, and dried by heating at 100 ° C. for 1 hour to obtain an electrophotographic photosensitive member of this example.

Comparative Example 5 A comparative photoreceptor was obtained in the same manner as in Example 11, except that a trinonylphenoxyphosphine-based AO agent was used in place of the AO agent [3A] -1 in CTL and CGL.

The photoconductors of Examples and Comparative Examples obtained as described above were mounted on a Konica U-Bix 3035, and 100,000 times of actual copying tests were carried out to visually determine the occurrence of cracks and other image defects during actual copying. At the same time, the developing unit is removed, an electrometer probe is arranged at that position, the black paper potential _Vb , the blank paper potential _VW , and the residual potential _Vr are measured at the initial stage and after 100,000 copies, and the results are displayed. The results are shown in FIG.

In the actual photographing of the electrophotographic photosensitive members of Example 11 and Comparative Example 5, the polarity of charging and transfer was changed from negative to positive.
The operation was performed by changing the positive toner developer to the negative toner developer.

Here, the black paper potential refers to the surface potential of the photoconductor when the above-described copying cycle is performed with a black paper original having a reflection density of 1.3, and the blank paper potential refers to the photoconductor when a white paper is used as the original. Represents the surface potential of

The results are shown in Table 4 below.

[0190]

[Table 4]

From the results shown in Table 4, it was found that the electrophotographic photosensitive member of the example showed a small decrease in the potential during actual photographing and a small decrease in the residual potential.
It is understood that the fatigue deterioration of the photoreceptor is small even if charging and exposure are repeated many times, but the fatigue deterioration of the electrophotographic photoreceptor of Comparative Example is remarkably large.

Also, in the actual photographed images, high quality images can be obtained all the time in the working example, but in the comparative example, fogging and the like occur from about tens of thousands of copies, so that a preferable image cannot be obtained.

[0193]

As is apparent from the above description, according to the photoreceptor of the present invention, the photoreceptor is excellent in film-forming properties, mechanical strength, and abrasion resistance, and has little fatigue deterioration in the process of repeated image formation. Effects such as stably obtaining a high-density clear image without fogging can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a layer of an electrophotographic photoreceptor of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 charge generation layer (CGL) 3 charge transport layer (CTL) 4 photosensitive layer 5 intermediate layer 6 layer containing charge transport material 7 charge generation material (CGM) 8 protective layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-269943 (JP, A) JP-A-3-91758 (JP, A) JP-A-5-134428 (JP, A) JP-A-63-1988 136051 (JP, A)

Claims (3)

(57) [Claims] 1. An electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance, a charge transporting substance and a binder resin on a conductive support, wherein the photosensitive layer is a binder resin represented by the following general formula [B ₁ ]:
And a copolymer compound having a structural unit represented by the following general formula [B ₂ ] as a main component, and a hindered phenol structural unit and / or a hindered amine structural unit in a molecule. An electrophotographic photoreceptor comprising a compound. Embedded image [Wherein R ₁ and R _{2 are a} hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group, R ₁ and R ₂
Is a C _{4 to} C ₁₀ cyclic hydrocarbon residue. R ₃ ,
R ₄ , R ₅ and R ₆ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group. Also, l, m, p, and q are integers of 1 to 4. ] 2. The compound represented by the general formula [B ₂ ] The electrophotographic photoreceptor according to claim 1, wherein 3. The compound represented by the general formula [B ₁ ] 3. The electrophotographic photosensitive member according to claim 2, wherein