JPH08234460A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE: To obtain an electrophotographic photoreceptor contg. dispersed fine pigment particles and having superior characteristics without carrying out dispersion treatment by forming an org. pigment from a soluble precursor of the pigment. CONSTITUTION: In the electrophotographic photoreceptor with an electrically conductive substrate and a photosensitive layer contg. an org. pigment as an electric charge generating material, the org. pigment is formed from a soluble precursor of the pigment. The org. pigment is preferably formed from the soluble precursor together with a compsn. for the photosensitive layer applied on the substrate. The electrically conductive substrate may be made of any known electrically conductive material such as Al foil or a film of polycarbonate, polyester, polyamide, polypyrrole or polyacetylene. Other may electrically conductive substrates are well known in the industry and may be used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a fine organic pigment as a charge generating material contained in a photosensitive layer of an electrophotographic photoreceptor from a soluble pigment precursor without a dispersion step,
The present invention relates to an electrophotographic photoreceptor that enables high electrophotographic sensitivity.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors which mainly use inorganic materials such as selenium, zinc oxide and cadmium sulfate have been widely used as electrophotographic photoreceptors. However, such an inorganic photoreceptor does not always satisfy the high performances required today, such as photosensitivity, thermal stability, anti-humidity and durability.

In order to overcome the drawbacks of such an inorganic photoconductor, an electrophotographic photoconductor using an organic pigment has been developed, and various organic pigments such as azo compounds, perylene compounds and polycyclic compounds are used as an organic charge generating material. Quinone compounds, quinacridone compounds and indigoid pigments having various structures have been used (JP-A-54-139540 and JP-A-56).
-4148, JP-A-56-119131, JP-A-6-
3-63046, JP-A-63-95455, JP-A-1-109352, US Pat. No. 3839034, US Pat. No. 4220697, US Pat. No. 4302521.
U.S. Pat. No. 4,431,722, West German Patent No. 22
37680, West German Patent No. 2948790, etc.).

In the electrophotographic photosensitive member, the particle size of the above-mentioned organic pigment is very important in view of the characteristics of electrophotography, and the organic pigment particles must be extremely small and finely dispersed. Therefore, in the prior art, the organic pigment powder is dispersed by pulverizing for a long time. However,
According to such a conventional technique, dispersion stability is inevitably lowered when a sufficiently fine particle size is obtained. Therefore, the resulting pigment powder was not sufficiently satisfactory when used in a high-performance electrophotographic photoreceptor.

Surprisingly, electrophotographic photoreceptors with excellent properties, containing well-dispersed and very fine pigment particles, are obtained by using pigment precursors without the need for a dispersion treatment. I understand.

The present invention relates to an electrophotographic photoreceptor including a conductive support and a photosensitive layer containing an organic pigment as a charge generating material, wherein the organic pigment is formed of a soluble organic pigment precursor. Preferably, the organic pigment is formed from a soluble organic pigment precursor with the photosensitive layer composition already coated on the conductive support.

The present invention also relates to a method for producing an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer containing an organic pigment as a charge generating material, which comprises (1) a soluble organic pigment precursor on the conductive support. Forming a body-containing layer; and (2)
Chemically regenerating the charge generating organic pigment from the soluble organic pigment precursor.

Soluble pigment precursors are known substances. This material consists of chromophore residues which are substituted with 1 to 5 chemically leaving soluble groups. In the elimination step, the unsubstituted chromophore regenerates in insoluble (pigmented) form. Regeneration chemistry from the soluble organic pigment precursor to the charge generating organic pigment can be carried out by known methods, such as thermal, chemical, photochemical means or a combination thereof. The most suitable means are heat treatments carried out alone or with chemical reagents such as acids.

A particularly suitable soluble pigment precursor is of formula (I):

[0010]

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(Wherein x is an integer of 0 to 4; A is perylenes, quinacridones, azo compounds, anthraquinones, phthalocyanines, dioxazines,
Isoindolinones, isoindolins, indigo,
A residue of a chromophore that is a quinophthalone or a pyrrolopyrrole, the residue of this chromophore having 1 to 5 N atoms bonded to a D ₁ group and x D ₂ groups, thereby providing A N
Each atom is, independently of the others, bound to 0, 1 or 2 groups D ₁ or D ₂ ; D ₁ and D ₂ are, independently of one another, of the formula (IIa) , Formula (IIb), Formula (IIc) or Formula (IId):

[0012]

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Wherein m, n and p are independently of each other 0 or 1; X represents a C ₁ -C ₁₄ alkylene group or a C ₂ -C ₈ alkenylene group; Y represents -T ₁
- (CH _{2) q} - group (wherein, q is an integer from 1 to 6,
T ₁ represents a a) cycloalkylene group C ₃ ~C _6; Z _{is, -T 1 - (CH 2)} r - group (wherein, r is 0
Is an integer of 6, T ₁ is the same as above); R ₁ and R
₂ are each independently a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₁ -C ₄ alkoxy group, a halogen atom, a cyano group, a nitro group or a C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy. Or, it represents a phenyl group or a phenoxy group which may be substituted with halogen; R ₃ and R ₄ are
Independently of one another hydrogen atom, C ₁ -C ₁₈ alkyl group, or a group of the formula:

[0014]

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Where X, Y, R ₁ , R ₂ , m and n
Is the same as above); or R ₃ and R
₄ together with the N atom to which they are attached form a pyrrolidinyl group, a piperidinyl group or a morpholinyl group;
Q ₁ is a hydrogen atom, a cyano group, a Si (R ₁ ) ₃ group, —C
A (R ₅ ) (R ₆ ) (R ₇ ) group (wherein R ₅ is a halogen and R ₆ and R ₇ are each independently a hydrogen atom or a halogen);

[0016]

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(Wherein R ₁ and R ₂ are the same as above), --SO ₂ R ₈ group or --SR ₈ group (wherein
R ₈ is C ₁ -C ₄ alkyl _{group), - CH (R 9)} 2
A group (wherein R ₉ is C ₁ -C ₄ alkyl, C ₁ -C ₄
Optionally substituted with alkoxy or halogen,
A phenyl group or a phenoxy group) or the formula:

[0018]

[Chemical 38]

Represents a group represented by the formula; Q ₂ is represented by the formula:

[0020]

[Chemical Formula 39]

(In the formula, R ₁₀ and R ₁₁ are independently of each other,
Hydrogen atom, C ₁ -C ₂₄ alkyl group, O, S or NR
A C ₁ -C ₂₄ alkyl group whose carbon chain is broken by ₁₈ ,
C ₃ -C ₂₄ alkenyl groups, C ₃ -C ₂₄ alkynyl groups, C
₄ -C ₁₂ cycloalkyl group, C ₄ -C ₁₂ cycloalkenyl group, or unsubstituted whether or C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogen, cyano or nitro, phenyl group Or a biphenyl group; R ₁₂ , R ₁₃ and R ₁₄ independently of each other represent hydrogen, a C ₁ -C ₂₄ alkyl group or a C ₃ -C ₂₄ alkenyl group; R ₁₅ is hydrogen, C ₁ To C ₂₄ alkyl group, C _{3 to} C ₂₄ alkenyl group or formula:

[0022]

[Chemical 40]

[0023] represents a group represented by; R ₁₆ and R _17, independently of one another, hydrogen atom, C ₁ -C ₆ alkyl group, C ₁ ~
C ₆ alkoxy group, halogen, cyano group, nitro group, N
(R ₁₈ ) (R ₁₉ ), or unsubstituted or halogen, cyano, nitro, C ₁ -C ₆ alkyl or C ₁
~ Represents a phenyl group substituted with C ₆ alkoxy;
R ₁₈ and R ₁₉ are independently of each other a C ₁ -C ₆ alkyl group; R ₂₀ is hydrogen or a C ₁ -C ₆ alkyl group; and R ₂₁ is hydrogen, C ₁ -C ₆ An alkyl group or a phenyl group which is unsubstituted or substituted by C _{1 to} C ₆ alkyl) which is a group represented by)) or a derivative thereof.

Preferably, each N atom of the residue of the chromophore attached to the D ₁ or D ₂ group is adjacent to or attached to at least one carbonyl group. Not all N atoms of the chromophore residue need be attached to the D ₁ or D ₂ groups. A (D ₁ ) (D ₂ ) _x is an additional group:

[0025]

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It may contain a = N-, -NH- or -NH ₂ group.

Conversely, more than _one D ₁ or D ₂ group may be attached to a single N atom (eg the chromophore is --NH.
When it contains _two groups, one or two groups D ₁ or D ₂ are attached to it, so that the remainder of A is

[0028]

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Will be indicated by).

The group A has the formula:

[0031]

[Chemical 43]

It is a residue of a chromophore of a known organic pigment having a skeleton of, for example, the formula:

[0033]

[Chemical 44]

[0034]

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[0035]

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[0036]

[Chemical 47]

[0037]

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(In the formula, M is, for example, H ₂ , Mg, Ca,
Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Z
r, Pd, Cd, Sn, Ce, Hg, Pb or Bi) or formula:

[0039]

[Chemical 49]

(Wherein G ₁ and G ₂ are, for example, independently of one another, of the formula:

[0041]

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Or a known derivative thereof, for example, an aryl group of a chromophore, is, for example,
Compounds substituted with alkyl, alkoxy, alkylthio, dialkylamino, cyano, nitro, halogeno, acetyl, benzoyl, carbonyl or carbamoyl.

C _1- in the formula (IIa) or (IIb)
The C ₁₄ alkylene group is a linear or branched alkylene group, for example, methylene, dimethylene, trimethylene, 1-methylmethylene, 1,1-dimethylmethylene, 1,1-dimethyldimethylene, 1,1- Dimethyl trimethylene, 1-ethyl dimethylene, 1-ethyl-1
-Methyl dimethylene, tetramethylene, 1,1-dimethyltetramethylene, 2,2-dimethyltrimethylene, hexamethylene, decamethylene, 1,1-dimethyldecamethylene, 1,1-diethyldecamethylene and tetradecamethylene. To be

The C ₂ -C ₈ alkylene group mentioned as X in the group of formula (IIa) or (IIb) is a linear or branched alkylene group, for example vinylene,
Arylene, metaarylene, 1-methyl-2-butenylene, 1,1-dimethyl-3-butenylene, 2-butenylene, 2-hexenylene, 3-hexenylene and 2-octenylene are mentioned.

Halogen as a substituent may be chloro, bromo, iodo, fluoro, preferably bromo or chloro, more preferably chloro.

C ₁ -C ₆ alkyl groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, n-amyl, t-amyl and hexyl. The C ₁ -C ₁₈ alkyl group, for example in addition to the above C ₁ -C ₆ alkyl group, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, and hexadecyl and octadecyl.

C ₁ -C ₄ alkoxy groups include, for example, methoxy, ethoxy, n-propoxy, isopropoxy and butoxy.

As the C ₃ -C ₆ cycloalkylene group,
Examples include cyclopropylene and cyclopentylene, with cyclohexylene being preferred.

Particularly preferred compounds of formula (I) are those in which x is 0
Or 1; the D ₁ and D ₂ groups are of the formula (IIIa)
Formula (IIIb), Formula (IIIc) or Formula (IIId):

[0050]

[Chemical 51]

(Where m is 0 or 1; X ₁
Is a C ₁ -C ₄ alkylene group or a C ₂ -C ₅ alkenylene group; R ₂₂ and R ₂₃ are, independently of one another, hydrogen, a C ₁ -C ₄ alkyl group, a methoxy group, a chloro or nitro group. Q ₃ is hydrogen, cyano, a trichloromethyl group, and has the formula:

[0052]

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A group represented by: --SO ₂ CH ₃ group or-
A SCH ₃ group; R ₂₄ and R ₂₅ independently of one another are hydrogen, a C ₁ -C ₄ alkyl group or a formula:

[0054]

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R ₂₄ and R ₂₅ together with the N atom to which they are attached form a piperidinyl group; and Q ₄ is of the formula:

[0056]

[Chemical 54]

(In the formula, R _{24 to} R ₂₈ are, independently of each other,
Hydrogen or a C ₁ -C ₁₂ alkyl group; R ₂₉ is hydrogen, a C ₁ -C ₁₂ alkyl group or a formula:

[0058]

[Chemical 55]

R ₃₀ is a group represented by hydrogen or a C ₁ -C ₄ alkyl group).

Particularly preferably, in the formula (I), x is 1 and the groups D ₁ and D ₂ are the same:

[0061]

[Chemical 56]

It is

Preferred compounds of formula (I) are: (a) formula (IVa) or formula (IVb):

[0064]

[Chemical 57]

(Wherein D ₃ is a hydrogen atom, a C ₁ -C ₆ alkyl group, unsubstituted or halogen or C ₁
A phenyl group, a benzyl group, a phenethyl group, or a D ₁ group substituted with C ₄ alkyl); (b) Formula (V):

[0066]

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(In the formula, R ₃₁ and R ₃₂ are, independently of each other, a hydrogen atom, a halogen atom, a C ₁ -C ₁₈ alkyl group,
A C ₁ -C ₄ alkoxy group or a phenyl group; E is a hydrogen atom or a D ₁ group, but at least one E is a D ₁ group); (c) Formula (VI) :

[0068]

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(In the formula, R ₃₃ represents a hydrogen atom, a halogen atom or a C ₁ -C ₁₈ alkyl group; E is a hydrogen atom or a group D ₁ , and at least one E is a D ₁ group.)
(D) Formula (VIIa), Formula (VIIb) or Formula (VIIc):

[0070]

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(In the formula, R ₃₄ is the formula:

[0072]

[Chemical formula 61]

Represents a group represented by: R ₃₅ is a hydrogen atom,
C ₁ -C ₁₈ alkyl group, a benzyl group, or a group of the formula:

[0074]

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Wherein R ₃₆ and R ₃₇ are, independently of each other, a hydrogen atom, a C ₁ -C ₁₈ alkyl group, a C ₁ -C ₄ alkoxy group, a halogen atom or trifluoro. A methyl group; E represents a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group); isoindolines; (e) Formula (VIII):

[0076]

[Chemical formula 63]

(In the formula, R ₃₈ represents a hydrogen atom, a cyano group, C
₁ -C ₄ alkyl group, a C ₁ -C ₄ alkoxy group or a halogen atom; but E represents a hydrogen atom or D ₁ group, at least one of E indigo compound represented by a is) ₁ group D; (F) Formula (IX):

[0078]

[Chemical 64]

(Wherein R ₃₉ and R ₄₀ independently of each other represent a hydrogen atom, a halogen atom, a C ₁ -C ₄ alkyl group or a C ₁ -C ₄ alkoxy group; E is a hydrogen atom or D represents a ₁ group, azo benzimidazolone compound is at least one of E indicated by a is) ₁ group D; (g) formula (X):

[0080]

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An anthraquinoid compound represented by the formula (wherein E represents a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group); (h) Formula (XI):

[0082]

[Chemical formula 66]

(In the formula, M ₁ is H ₂ , Zn, Cu, N
i, Fe, Ti (O) or V (O); X ₂ is
-CH (R ₄₂₎ - or -SO ₂ - represents; R ₄₁ is a hydrogen atom, C ₁ -C ₄ alkyl _{group, N (E) R 42,} -NH
COR ₄₃ −, −COR ₄₃ or the formula:

[0084]

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R ₄₂ represents a hydrogen atom or a C ₁ -C ₄ alkyl group; R ₄₃ represents C
Represents ₁ -C ₄ alkyl group; R ₄₄ represents a hydrogen atom, a halogen atom or C ₁ -C ₄ alkoxy group; z is 0 or 1; y is an integer of from 1 to 4; E represents hydrogen Phthalocyanines represented by an atom or a D ₁ group, wherein at least one E is a D ₁ group); (i) Formula (XII):

[0086]

[Chemical 68]

(Wherein G ₃ and G ₄ independently of one another are of the formula:

[0088]

[Chemical 69]

(In the formula, R ₄₅ and R ₄₆ are, independently of each other, hydrogen, halogen, a C ₁ -C ₁₈ alkyl group, C ₁ -C
₁₈ alkoxy group, C ₁ -C ₁₈ alkylmercapto group, C
₁ -C ₁₈ alkylamino group, a cyano group, a nitro group, a phenyl group, a trifluoromethyl group, C ₅ -C ₆ cycloalkyl _{group, -CH = N- (C 1 ~C} 18 alkyl), the formula:

[0090]

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A group represented by: imidazolyl group, pyrazolyl group, triazolyl group, piperazinyl group, pyrrolyl group,
Represents an oxazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzimidazolyl group, a morpholinyl group, a piperidinyl group or a pyrrolidinyl group; T ₂ represents -C
_{H 2 -, CH (CH 3} ) -, - C (CH 3) 2 -, - CH =
N-, -N = N-, -O-, -S-, -SO-, -SO
₂ - or -NR ₅₁ - represents; R ₄₇ and R ₄₈ are, independently of one another, hydrogen, halogen, C ₁ -C ₆ alkyl group,
Represents a C ₁ -C ₁₈ alkoxy group or a cyano group; R ₄₉ and R ₅₀ independently of one another are hydrogen, halogen or C
Represents a _{1 to} C ₆ alkyl group; R ₅₁ represents hydrogen or C ₁ to
Represents a C ₆ alkyl group; E represents a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group); a pyrrolo [3,4-c] pyrrole; XIIIa) or formula (XIIIb):

[0092]

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[0093]

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(Wherein R ₅₂ , R ₅₃ , R ₅₄ and R ₅₅ are
Independently of each other, hydrogen, C ₁ -C ₁₈ alkyl group, C _1-
A C ₄ alkoxy group, halogen or trifluoromethyl group).

In the phthalocyanines of the formula (XI), M ₁ is H
₂ , Cu or Zn; X ₂ is —CH ₂ — or —
SO ₂ −; R ₄₁ is a hydrogen atom, —NHCOCH ₃ or benzoyl group; and a compound in which z is 1 is preferable.

In the pyrrolo [3,4c] pyrrole compound of formula (XII), preferably G ₃ and G ₄ are independent of each other and have the formula:

[0097]

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(In the formula, R ₅₆ and R ₅₇ are each independently of each other hydrogen, chloro, bromo, a C ₁ -C ₄ alkyl group, C
₁ -C ₆ alkoxy group, C ₁ -C ₆ alkylamino group,
Represents a cyano group or a phenyl group; T ₃ represents —O—, —
_{NH -, - N (CH 3} ) -, - N (C 2 H 5) -, - N = N
Represents a group represented by —or —SO ₂ —).

In the pyrrolo [3,4c] pyrrole compound of formula (XII), more preferably G ₃ and G ₄ are each of the formula:

[0100]

[Chemical 74]

(In the formula, R ₅₈ and R ₅₉ are each independently of each other hydrogen, methyl group, t-butyl group, chloro, bromo,
Represents a cyano group or a phenyl group).

In the present invention, the choice of the type of pigment precursor for use, however, results in the desired result, that is, an electrophotographic photosensitive layer containing very small and finely dispersed organic pigment particles. Not mandatory to get. For convenience, the chromophore A is chosen for its stability and photoelectric properties. In addition, the bonded D ₁ group or D ₂ group is used so that the pigment precursor is stable at room temperature, or under mild conditions, for example, 50 to 200 ° C. and an acid concentration of 0 to 0.1 mol / mol.
It is selected so that under the conditions of l, the pigment can already be regenerated. However, harsher regeneration conditions usually do not harm the pigment. Formula (IVa), Formula (IVb), Formula (V), Formula (VI), Formula (VIIa), Formula (VIIb), Formula (VII
The pigment precursors of c), formula (VIII), formula (IX), formula (X), formula (XI), formula (XII), formula (XIIIa) and formula (XIIIb) particularly meet the above requirements.

The selection of the pigment precursor is not limited to the above-mentioned compounds, and in the present invention, all known pigment precursors which decompose into a pigment under thermal, chemical or photochemical conditions or a combination thereof are used. Is suitable for use. Known such compounds are for example represented by the following formula (XIV)
Is a compound of.

Therefore, the present invention also provides a conductive support and a charge generating material of the formula (XIV):

[0105]

[Chemical 75]

(In the formula, L ₁ and L ₂ are independently of each other halogen, a C ₁ -C ₁₈ alkoxy group, a C ₂ -C ₁₈ dialkylamino group, a C ₁ -C ₁₈ cycloalkylamino group, ( N′-C ₁ -C ₆ alkyl) piperidino group or morpholino group, and M ₂ represents two hydrogen or at least a divalent metal or oxo metal) or a derivative thereof via a pigment precursor. The present invention relates to an electrophotographic photoreceptor including a formed photosensitive layer containing an organic pigment.

Among the phthalocyanines of formula (XIV), M ₂
Is H ₂ , Zn, Cu, Ni, Fe, Ti (O) or V
(O), L ₁ and L ₂ are, independently of each other, C
₂ -C ₁₈ dialkylamino group, C ₁ -C ₁₈ cycloalkylamino group, (N'-C ₁ ~C ₆ alkyl) compound or a piperidino group or a morpholino group, a phenyl group group 1 to 16 bromo or Its derivatives substituted with chloro are preferred.

More preferred compounds are those in which M ₂ is H ₂ , Zn
Or a compound of formula (XIV) which is Cu and in which both L ₁ and L ₂ are morpholino, or the phenyl group is 4, 8, 1
It is a derivative thereof substituted with 2 or 16 chloro.

Pigment precursors of formula (I), and especially of formula (IV
a), formula (IVb), formula (V), formula (VI), formula (VIIa),
Formula (VIIb), Formula (VIIc), Formula (VIII), Formula (IX), Formula (X), Formula (XI), Formula (XII), Formula (XIIIa), Formula (XIII
The precursor of b) comprises a pigment of the formula A (H) (H) _x (XIV) and a dicarbonate, trihaloacetate, azide, carbonate or alkylidene-iminoxyformate.
It can be produced by reacting with a polar organic solvent in the presence of a base catalyst. For example, Angewandte Chemie 68/4, 13
3-150 (1956), J. Org. Chem. 22, 127-132 (1957), EP-6
48770 and EP-648817.

Pigment precursors of formula (XIV) are described by F. Baumann et al. [Angew. Chem. 68, 133-168 (1956) and USP 2,683,643].
And CJ Pedersen (J. Org. Chem. 22, 127-132 (1957),
USP2,662,895, USP2,662,896, USP2,662,897].

The relatively coarse particle size pigments are also suitable as starting materials for the above-mentioned preparation of pigment precursors. No grinding step is usually required.

The pigment precursor of formula (I) or formula (XIV) is
Ordinary organic solvents such as ether solvents such as tetrahydrofuran and dioxane; glycol ether solvents such as ethylene glycol methyl ether, ethylene glycol ether, diethylene glycol monomethyl ether or diethylene glycol monomethyl ether; acetonitrile, benzonitrile, N, N-dimethyl Amphoteric solvents such as formamide, N, N-dimethylacetamide, nitrobenzene or N-methylpyrrolidone; halogenated aliphatic hydrocarbon solvents such as trichloroethane; aromatic hydrocarbons such as benzene, toluene, xylene, anisole or chlorobenzene. System solvent;
It is soluble in N-containing aromatic heterocyclic solvents such as pyridine, picoline and quinoline. Preferred solvents are tetrahydrofuran, N, N-dimethylformamide and N
-Methylpyrrolidone.

The pigment precursors of formula (I) and formula (XIV) are
The pigments can be readily reconstituted by known methods, such as those described in EP648770 or EP648817. Preferred methods are: (a) heating to 50 to 150 ° C. with an inorganic or organic acid and then cooling to 30 ° C. or lower; or (b) heating to 120 to 350 ° C. in the absence of acid.
Is.

In the treatment of (a) or (b), the substituent D ₁ in formula (I) and D ₂ if applicable, or the substituents L ₁ and L ₂ in formula (XIV) It dislodges and, as a result, reverts to the original pigment so that it can be recognized by its characteristic color development.

The pigment precursors of formula (I) and formula (XIV) are
Good compatibility with various resins.

Therefore, a single-layer type or two-layer type electrophotographic photosensitive member can be produced by using the pigment precursors of the formula (I) and the formula (XIV) as follows: (1) Two-layer type photosensitive member Electrophotographic photoreceptor having a layer: a pigment precursor of formula (I) and formula (XIV) is dissolved in an organic solvent, and therein, as a binder, polycarbonate, polyvinyl butyral, polyurethane, epoxy resin, silicone resin, polyvinyl resin The composition obtained by dispersing formal, acrylic resin, poly-N-vinylcarbazole and polyvinylpyrrolidone was added to 0.05
A film is obtained by coating on a conductive support to a thickness of .about.5 .mu.m, followed by drying. Then, the obtained film is heated until the color change is completed to obtain a charge generation layer (CGL) exhibiting the original pigment color. Then, a charge transport material such as N, N'-diphenyl-N, N'-bis (dimethylphenyl) -1,1'-biphenyl-4,4'-diamine,
Charge transport layer (CTL) containing triphenylmethane, stilbene derivative, enamine derivative or hydrazone derivative
Are provided on the charge generation layer.

Alternatively, a charge generation layer may be laminated on the charge transport layer to form a photosensitive layer.

(2) Electrophotographic photoreceptor having a single-layer type photosensitive layer: The pigment precursor of the formula (I) and the formula (XIV), the charge-transporting material and the resin thereof are dissolved in an organic solvent to obtain a resultant. The obtained solution is coated on a conductive support and dried to form a film. The resulting film is then heated until the color change is complete.

In either case of the single-layer type or the double-layer type, any one of the support, the photosensitive layer and the charge-transporting layer 2
An undercoat layer may be provided between the layers, and a surface protective layer may be provided on the photosensitive layer or the charge transport layer.

Instead of being formed by the solvent coating method, the photosensitive layer (or another layer) may be applied on the support by a laminating method. In this case, the lamination temperature is preferably selected so that the pigment is formed during the lamination process. As a result, subsequent heating or chemical treatment is unnecessary.

Any known conductive material can be used as the conductive support of the present invention. By way of example only, for the purpose of illustration and not limiting the scope of the invention,
Mention may be made of thin aluminum foils or polycarbonate, polyester, polyamide, polypyrrole or polyacetylene films. Many other conductive supports are well known in the art and can be used.

In the prior art, a high-sensitivity two-layer type electrophotographic photosensitive member is processed by an extended milling operation of pigment.
It has been produced only by crushing into fine particles by subjecting it to procedure). In addition, the conventional single-layer type electrophotographic photoreceptor in which the pigment is finely and uniformly dispersed is
It was very difficult to manufacture.

The present invention provides a means for producing a two-layer type or single-layer type electrophotographic photosensitive member having improved sensitivity and reduced residual potential. Here, the pigments, which are extremely simple and can be regenerated well, are, to their advantage, of fine size and very evenly dispersed. This instant electrophotographic photoreceptor, i.e., a photoreceptor in which the charge generating organic pigment is formed from a soluble organic pigment precursor, is therefore an electrophotographic process, such as electrophotography performed in a photocopier or laser printer. It can be used advantageously in the method.

The present invention further provides for the production of resin treated pigments having superior electrical properties for use in electrophotographic photoreceptors in a shorter time than is possible according to the prior art. It also provides the means.

The following examples are illustrative of the present invention.

A. Example of Preparation of Pigment Precursor Example A1 : 6.0 g of di-t-butyl dicarbonate (0.0275 mol) was added to 1.8 g of quinacridone (0.0057) in 90 ml of N, N-dimethylformamide.
6 g) and 0.3 g of 4-dimethylaminopyridine (0.
(00246 mol). The resulting purple suspension was stirred overnight at room temperature while avoiding the effects of atmospheric humidity. The color of the suspension turned yellowish orange. Subsequently, the reaction mixture was poured into 100 ml of distilled water with stirring. The yellow precipitate is separated by filtration, the residue is washed with distilled water and dried to give the formula:

[0127]

[Chemical 76]

2.8 g of the compound represented by ¹ H-NMR (CDCl ₃ ): 8.74 (s, 2H); 8.41 (d, 2H); 7.84 (d, 2H);
7.72 (t, 2H); 7.38 (t, 2H); 1.75 (s, 18H)

Example A2 : 45.31 g of di-t-butyl dicarbonate (0.2076 mol) were divided into two portions to give 1
10.3 in 50 ml N, N-dimethylformamide
1 g of indigo (0.0393 mol) and 2.79 g of 4-
Added to a suspension of dimethylaminopyridine (0.0228 mol). The resulting mixture changed color from dark blue to purple during 20 hours of stirring at room temperature. The product is separated by filtration, the residue is washed first with 20 ml of dimethylformamide and then with distilled water and dried to give the formula:

[0130]

Embedded image

A bright red solid of the compound of formula 9.7 was obtained.
9 g were obtained. An additional 5.13 g of the compound was obtained by diluting the filtrate with distilled water. The total end of compounds was 14.93 g. ¹ H-NMR (CDCl ₃ ): 8.02 (d, 2H); 7.76 (d, 2H); 7.61 (t, 2H);
7.21 (t, 2H); 1.62 (s, 18H)

Example A3 : 0.18 g of 4-dimethylaminopyridine (0.00147 mol) was added to 80 ml of N, N-.
The formula in dimethylacetamide:

[0133]

Embedded image

1.5 g (0.00337) of the pigment represented by
mol) and 9.7 g of di-t-butyl dicarbonate (0.
And 0444 mol). The result was stirred at room temperature for 24 hours. The reaction mixture was poured into 200 ml distilled water with stirring. The yellow precipitate thus obtained is separated by filtration,
The residue was washed with distilled water and then dried under reduced pressure at room temperature to give the formula:

[0135]

Embedded image

2.71 g (theoretical 9
5%). ¹ H-NMR (CDCl ₃ ): 8.22 (d, 2H); 7.83 (d, 2H); 7.72 (t, 2H);
7.63 (t, 2H); 7.56 (d, 2H); 7.42 (d, 2H); 1.45 (s, 36H)

Example A4 : 0.2 g of 4-dimethylaminopyridine (0.00164 mol) in 50 ml of N, N-dimethylacetamide of the formula:

[0138]

Embedded image

1.4 g (0.0
037 mol) and 2.67 g of di-t-butyl dicarbonate (0.01221 mol) were added. The reaction mixture was stirred at room temperature for 48 hours, forming an orange suspension. The yellow precipitate is isolated by filtration, the residue is washed with a small amount of N, N-dimethylacetamide and then with distilled water, then dried under reduced pressure at room temperature and has the formula:

[0140]

[Chemical 81]

0.67 g (theoretical value 3) of the product represented by
1%) was obtained. ¹ H-NMR (CDCl ₃ ): 15.9 (s, br, 1H); 11.17 (s, br, 1H); 7.94
(d, 1H); 7.90 (d, 1H); 7.85 (d, 1H); 7.64 (d, 1H); 7.06-
7.04 (m, 2H); 2.65 (s, 3H); 2.35 (s, 3H); 2.32 (s, 3H); 1.
64 (s, 9H)

Examples A5-A8 : General formulas listed below:

[0143]

[Chemical formula 82]

The compounds of formula (I) were prepared according to the general procedure described in Example A1 using the corresponding dicarbonates.

[0145]

[Table 1]

Example A9 : 27.94 g of di-t-butyl dicarbonate (0.128 mol) in 14.3 g of 500 ml of tetrahydrofuran (dried with molecular sieves) in 3 portions over 1 hour. 1,4
-Diketo-2,5-dihydro-3,6-diphenyl-pyrrolo- [3,4-c] pyrrole (0.0512 mol) and 3.23 g of 4-dimethylaminopyridine (0.026).
4 mol). The resulting red suspension was stirred at room temperature for 2 hours while preventing the influence of atmospheric humidity to obtain a deep green solution. The solvent was distilled off under reduced pressure. The yellow residue thus formed is washed first with a 5% aqueous sodium hydrogen carbonate solution and then with water,
Dry under reduced pressure and formula:

[0147]

[Chemical 83]

24.5 g (theoretical value: 9) of the compound represented by
8%) was obtained. ¹ H-NMR (CDCl ₃ ): 7.75 (d, 4H); 7.48-7.50 (m, 6H); 1.40
(s, 18H)

Example A10 : Subsequently, 0.85 g of 4-dimethylaminopyridine (0.007 mol) and 6.55 g of di-t-butyldicarbonate (0.030 mol) were added.
4.29 g of 1,4-diketo-3,6-bis (4-chlorophenyl) pyrrolo [3,4-c] pyrrole (0 in 50 ml of N, N-dimethylformamide (dried with molecular sieves) 0.012 mol). The resulting reaction mixture was stirred at room temperature while avoiding the effects of atmospheric humidity. After 2 hours, an additional 6.55 g of di-t-butyl dicarbonate was added to the reaction mixture and stirring was continued for 72 hours. Subsequently, the reaction mixture was poured into 500 ml of distilled water with sufficient stirring. The precipitated orange-brown solid was isolated by filtration, the residue was washed with cold distilled water, dried under reduced pressure at room temperature and of the formula:

[0150]

[Chemical 84]

6.1 g (theoretical value 91) of the compound represented by
%) Was obtained. ¹ H-NMR (CDCl ₃ ): 7.69 (d, 4H); 7.46 (d, 4H); 1.44 (s, 18H)

Example A11 : 24.29 g of di-t-butyl dicarbonate (0.111 mol) were added to 100 ml of N, N.
-8.44 g of 1,4-diketo-2,5-in dimethylformamide (dried with molecular sieves)
Dihydro-3,6-bis (4-t-butylphenyl) pyrrolo [3,4-c] pyrrole (0.021 mol) and 1.4
9 g of 4-dimethylaminopyridine (0.0012 mol)
Was added to the solution of the mixture containing. The resulting red suspension was stirred at room temperature for 3 hours, avoiding the effects of atmospheric humidity, at which time the color of the suspension turned orange. The precipitated solid is isolated by filtration, the residue is washed many times with cold distilled water and then dried under reduced pressure at room temperature and is of the formula:

[0153]

Embedded image

11.40 g (theoretical value: 90%) of a bright yellow solid represented by were obtained. ¹ H-NMR (CDCl ₃ ): 7.69 (d, 4H); 7.48 (d, 4H); 1.43 (s, 18
H); 1.34 (s, 18H)

Examples A12-A20 : Formulas according to the general procedure described in Examples A9-A11:

[0156]

[Chemical 86]

A 2,5-dihydro-pyrrolo [3,4-c] pyrrole derivative represented by the formula:

[0158]

[Chemical 87]

Prepared from the corresponding compounds listed below, represented by:

[0160]

[Table 2]

Examples A21 to A24 : As in the methods described in Examples A9 to A11, the formula:

[0162]

Embedded image

The compounds of formula I were prepared respectively from the corresponding compounds listed below.

[0164]

[Table 3]

Example A25 : Di-t-butyl dicarbonate was replaced with an equivalent amount of diethyl dicarbonate.
The procedure of Example A9 is repeated in the same way, the formula:

[0166]

[Chemical 89]

Pyrrolo [3,4-c] pyrrole represented by the following formula was obtained in a theoretical yield of 67%. ¹ H-NMR (CDCl ₃ ): 7.75 (m, 4H); 7.49 (m, 6H); 4.31 (q, 4H);
1.22 (t, 6H)

Example A26 : 14.93 g of N, N-bis (t-butoxycarbonyl) -1,4-diketo-2,5-dihydro-3,6-prepared as described in Example A9.
Diphenyl-pyrrolo [3,4-c] pyrrole was added to 1.1
Recrystallized from l of boiling ethanol. The red precipitated crystals are chromatographed on silica gel using a methylene chloride / ethyl acetate (9: 1) solvent system,
formula:

[0169]

[Chemical 90]

A diketopyrolo [3,4-c] pyrrole represented by the following formula was obtained. ¹ H-NMR (CDCl ₃ ): 9.43 (s, br, 1H); 8.30 (m, 2H); 7.81 (m, 2
H); 7.51 (m, 6H); 1.4 (s, 9H)

Examples A27 to A33 : General formula:

[0172]

Embedded image

The mono-substituted compounds listed below, shown below, were each prepared from the corresponding di-substituted pyrrolo [3,4-c] pyrrole compound in a manner similar to Example A26.

[0174]

[Table 4]

Example A34 : 0.28 g of solid sodium hydride (0.007 mol) under argon atmosphere
0.5 g of 1,4-in 17 ml of tetrahydrofuran
Diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole (0.00175 mol) was added to a suspension. After stirring the resulting mixture for 24 hours, 0.67 ml of n-butyl chloroformate (0.007 mol) was added to it and the resulting suspension was stirred overnight. The mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was taken up in water / diethyl ether, the organic layer was dried over MgSO ₄ and then concentrated under reduced pressure. The residue is taken up in n-hexane, and the precipitated yellow powder is collected by filtration and washed with a small amount of n-hexane to give N, N'-bis (n-butoxycarbonyl) -1,4-diketo as yellow fluorescent powder. 0.62 g (theoretical value 73%) of 2,2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole was obtained. ¹ H-NMR (CDCl ₃ ): 7.72 (m, 4H); 7.49 (m, 6H); 4.32 (q, 4H);
1.23 (t, 6H)

B. Preparation of Fine Particle Size Pigment Example B1 : 0.07 g of the product obtained in Example A1 was heated in a test tube at 180 ° C. for 10 minutes. The analytical data of the purple powder thus obtained are all of the formula:

[0177]

Embedded image

Consistent with those of pure quinacridone shown in. The yield (% conversion) was 99%.

Example B2 : 0.07 g of the product obtained in Example A3 was dissolved in 1 ml of acetone and the resulting solution was immediately added to 1 ml of 33% HCl. The analytical data of the red powder thus obtained is given by the formula:

[0180]

Embedded image

Consistent with those of the pure pigments shown in. The converted yield was 99%.

Example B3 : Prepared as in Example A9, 0.
07 g of N, N-bis (t-butoxycarbonyl)-
1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole was added in a test tube at 10
Heated at 180 ° C for minutes. The analytical data of the red powder thus obtained were all in agreement with those of 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole. The yield was 99%.

Example B4 : prepared as in Example A9, 0.
07 g of N, N-bis (t-butoxycarbonyl)-
The 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole was immediately poured into 1 ml of 33% HCl. The analytical data of the red powder thus obtained were all in agreement with those of 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole. The yield was 99%.

Example B5 : 1.5 g of the product obtained in Example A10 and toluene-4 in 75 ml of tetrahydrofuran.
A suspension of 5.1 g of sulfonic acid monohydrate was refluxed with stirring for 15 hours and then cooled to 30 ° C. The precipitated pigment is isolated by filtration, subsequently washed with methanol and water, dried and red powder (β-1,4-diketo-
3,6-diphenyl-pyrrolo [3,4-c] pyrrole)
Of 0.55 g (theoretical value: 57.2%) was obtained. Analytical value CHNCl calculated value 60.53 2.82 7.84 19.85 experimental value 60.38 2.96 7.69 19.42

C. Preparation of Instant Electrophotographic Photoreceptor Example C1 : 0.3387 g of the product of Example A9 was added to 3.446 g of 0.65 wt% butyral resin (B
MS, manufactured by Sekisui Chemical Co., Ltd.) to obtain a charge generation layer composition (C1G).

The charge transport layer composition (C1T) was 6.00.
In g toluene, 1.00 g N, N'-bis (2,2
4-dimethylphenyl) -N, N'-diphenyl-1,
It was prepared by dissolving 1'-biphenyl-4,4'-diamine and 1.00 g of polycarbonate (Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.).

The above charge generation layer composition (C1G) was applied to a wire bar (KCC rod number 2, RK-Print-Coat Inst).
(produced by ruments) was applied onto an aluminum support and dried at 45 ° C. for 30 minutes. Subsequently, the sample thus obtained was heat-treated at 170 ° C. for 20 minutes, and it was confirmed that the film formed on the aluminum support was sufficiently changed from yellow to reddish orange. The charge transport layer composition (C1T) was applied onto the charge generation layer (C1G) formed in this manner by a wire bar (KCC rod number 8, RK-Print-Coat Instrument).
(manufactured by S.) and dried at 50 ° C. for 60 minutes to obtain a two-layer type electrophotographic photoreceptor.

Example C2 : 0.3115 g of the product of Example A10 in 80 parts of a solution of 5.946 g of 0.38 wt% butyral resin (BM-S) in 1,2-dichloroethane.
The charge generation layer composition (C
2G) was obtained.

The charge generation layer composition (C2G) thus obtained was coated on an aluminum support using a wire bar (No. 2) and dried at 45 ° C. for 30 minutes.
Subsequently, the sample thus obtained was heat-treated at 155 ° C. for 15 minutes, and it was confirmed that the film formed on the aluminum support was sufficiently changed from yellow to red. Then, a two-layer type electrophotographic photosensitive member was produced in the same manner as in Example C1.

Example C3 : 0.300 g of the product of Example A11 was dissolved in 5.446 g of a 0.41 wt% butyral resin (BM-S) solution in THF to form a charge generating layer composition (C3G). Got Then, the composition is coated on an aluminum support using a wire bar (No. 2), 45
Dry at 30 ° C. for 30 minutes. Subsequently, the sample thus obtained was heat-treated at 150 ° C. for 30 minutes, and it was confirmed that the film formed on the aluminum support was sufficiently changed from yellow to orange. Then, a two-layer type electrophotographic photosensitive member was produced in the same manner as in Example C1.

Example C4 : 0.3282 g of the product of Example A1 was dissolved in 5.446 g of a 0.41 wt% butyral resin (BM-S) solution in dichloromethane to form a charge generating layer composition (C4G). Got Then, the composition was coated on an aluminum support using a wire bar (No. 2) and dried at 45 ° C. for 30 minutes. Subsequently, the sample thus obtained was heat-treated at 150 ° C. for 20 minutes, and it was confirmed that the film formed on the aluminum support was sufficiently changed from yellow to reddish purple. Then, a two-layer type electrophotographic photosensitive member was produced in the same manner as in Example C1 except that THF was used instead of toluene as a solvent.

Example C5 : 0.0508 g of the product of Example A9, 0.50 g of N, N'-bis (2,4-dimethylphenyl) -N, N'-diphenyl-1,1'-biphenyl-4. , 4'-diamine and 0.50 g of polycarbonate (Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.)
Was dissolved in 3.0 g of THF. The resulting solution was coated on an aluminum support using a wire bar and dried at 50 ° C for 60 minutes. After forming the film,
The film was further heat treated at 150 ° C. for 30 minutes to obtain a single-layer type electrophotographic photoreceptor.

Example C6 : A single-layer type electrophotographic photosensitive member was prepared as in Example A9.
Was replaced with 0.467 g of the product of Example A10,
And the heat treatment to be applied after the film formation is 150 ° C. for 15
Prepared in a manner similar to Example C5 except that it was run for minutes.

Example C7 : A single-layer type electrophotographic photosensitive member was prepared as in Example A9.
Was prepared in the same manner as Example C5, except that the product of Example A11 was replaced with 0.0450 g of the product of Example A11, and the heat treatment to be applied after film formation was carried out at 150 ° C. for 60 minutes.

Example C8 : A single-layer type electrophotographic photosensitive member was prepared as in Example A9.
Was replaced with 0.0492 g of the product of Example A1,
And the heat treatment to be applied after the film formation is 60 at 120 ° C.
Prepared in a manner similar to Example C5 except that it was run for minutes.

Example C9 : in 60 g of cyclohexanone,
1.524 g of the product of Example A9, 0.10 g of butyral resin (BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 1.134 g of paratoluene sulfonic acid were added at 110 ° C.
And refluxed for 300 minutes. A red precipitate was obtained, which was suction filtered and washed with water. 80 of the residue (C9R)
The resin-containing pigment was obtained by drying at 12 ° C. for 12 hours.

0.2 g of the resin-containing pigment (C9R),
2.5 g toluene and 10 g glass beads (GB
-603M, manufactured by Toshiba Ballotini Co., Ltd.)
Was placed in a 30 ml brown sample glass bottle. Each glass bottle was shaken on a shaker (SA-31, manufactured by Yamato Scientific Co., Ltd.) for 2, 4, 6, 8 or 10 hours. The dispersion liquid thus obtained was used as a wire bar (No. 2).
Was applied onto an aluminum support and dried. After drying, as in Example C1, the charge transport layer composition (C1T) was further applied using a wire bar to obtain a two-layer type electrophotographic photoreceptor. It was confirmed that the produced electrophotographic photosensitive member had metallic luster and the pigment particles were very fine.

Example C10: A two-layer type electrophotographic photosensitive member was prepared as in Example A.
The product of 1 has the formula:

[0199]

Embedded image

Prepared as in Example C4, except substituting the product shown in.

Examples C11 to C27 : Two-layer type electrophotographic photoconductors, the products of Example A9 were used in Examples A2 to A5, A8 and A, respectively.
12, A16 to A19, A21, A23 and A25 to
Prepared as in Example C1 by substituting the product for A29.

Examples C28 to C40 : Single-layer type electrophotographic photoreceptors, and the products of Example A1 were obtained from Examples A6, A7 and A13, respectively.
A15, A20, A22, A24 and A30 to A34
Prepared as in Example C5 by substituting the product from.

D. Manufacture of electrophotographic photoreceptors for comparison

Comparative Example D1 : Formula:

[0205]

Embedded image

0.20 g of 1,4-diketo represented by
2,5-dihydro-3,6-diphenyl-pyrrolo [3,3
4-c] pyrrole, 2.659 g of 0.83 wt% butyral resin (BM-S, manufactured by Sekisui Chemical Co., Ltd.)
Toluene solution and 10 g of glass beads (GB-60
3M, manufactured by Toshiba Ballotini Co., Ltd.)
20 ml on a shaker (SA-31, manufactured by Yamato Scientific Co., Ltd.) after placing it in a brown sample glass bottle with a capacity of ml.
Shaking for time, control charge generating layer composition (D1G)
I got After obtaining the dispersion, wire it (No. 2)
Coated on an aluminum support using
Dried for minutes. The charge transport layer composition (C1T) was applied to a charge generation layer (D1) for comparison using a wire bar (No. 8).
G) was coated on the above and dried at 50 ° C. for 60 minutes to obtain a two-layer type electrophotographic photosensitive member for comparison.

Comparative Example D2 : Comparative charge generating layer composition (D
2G) and a two-layer electrophotographic photoreceptor for comparison, 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole having the formula:

[0208]

[Chemical 96]

Comparative Example D1 except that it was replaced with 1,4-diketo-2,5-dihydro-3,6-di (4-chloro-phenyl) -pyrrolo [3,4-c] pyrrole represented by It was manufactured in the same manner as.

Comparative Example D3 : Comparative charge generation layer composition (D
3G) and a two-layer electrophotographic photoreceptor for comparison with 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole having the formula:

[0211]

Embedded image

A comparison was made except that the 1,4-diketo-2,5-dihydro-3,6-di (4-t-butyl-phenyl) -pyrrolo [3,4-c] pyrrole represented by Prepared in a manner similar to Example D1.

Comparative Example D4 : Comparative charge generation layer composition (D
4G) and a two-layer electrophotographic photoreceptor for comparison with 1,4-diketo-2,5-dihydro-3,6-diphenyl-pyrrolo [3,4-c] pyrrole having the formula:

[0214]

Embedded image

A compound was prepared in the same manner as in Comparative Example D1 except that the quinacridone represented by the formula was replaced.

Comparative Example D5 : 0.50 g of the product of Example A9, 0.50 g of N, N'-bis (2,4-dimethylphenyl) -N, N'-diphenyl-1,1'-biphenyl- 4,4'-diamine and 0.50 g of polycarbonate (Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.)
Was dissolved in 2.6 g of toluene. Then, Comparative Example D
0.429 g of the comparative charge generation layer composition prepared in 1 (D1G) was added thereto, followed by stirring for 10 minutes using a stirrer. The sample thus obtained was applied on an aluminum support using a wire bar (No. 8) and dried at 50 ° C. for 60 minutes to obtain a comparative single-layer type electrophotographic photoreceptor.

Comparative Example D6 : A comparative single layer electrophotographic photoreceptor was compared except that the comparative charge generating layer composition (D1G) was replaced with the comparative charge generating layer composition (D2G) of Example D2. Prepared in a manner similar to Example D5.

Comparative Example D7 : A comparative single layer electrophotographic photoreceptor was compared except that the comparative charge generating layer composition (D1G) was replaced with the comparative charge generating layer composition (D3G) of Example D3. Prepared in a manner similar to Example D5.

Comparative Example D8 : A comparative single layer electrophotographic photoreceptor was compared except that the comparative charge generating layer composition (D1G) was replaced with the comparative charge generating layer composition (D4G) of Example D4. Prepared in a manner similar to Example D5.

Comparative Example D9 : A sample of the same charge generation layer composition of Example D1 (D1G) was subjected to the ball milling step of Example C9 for 2, 4, 6, 8 or 10 hours. Then, each sample treated in this way was treated with a wire bar (2
No.) was used for coating on an aluminum support. After drying, the charge transport layer composition (C1T) was further applied and dried using a wire bar (No. 8), and the same method as in Example 1 was used.
A two-layer type electrophotographic photosensitive member for comparison was obtained.

E. Examination of Electrophotographic Characteristics The electrophotographic characteristics of the electrophotographic photoreceptors obtained in Examples C1 to C9 and Comparative Examples D1 to D9 were measured by an electrostatic charging tester (EPA-8).
100, manufactured by Kawaguchi Denki Seisakusho Co., Ltd.). Examples of negative charges are C1-C4, D1-D
A positive charge was applied to the photoreceptors of Examples C5 to C8, D5 to D8, as opposed to 4, C9 and D9. The first surface potential V ₀ (v) of each photoconductor was measured, then the monochromatic light (10μW / cm ²⁾ was irradiated to the photoreceptor, obtaining a semi-attenuation exposure E _1/2 (μJ / cm ²⁾ Therefore, the time was measured until the surface potential V ₀ became half of the initial value. Furthermore, the surface potential after 3.0 seconds is shown by V _res (v). The results are shown in Table 1
Summarized in 3.

[0222]

[Table 5]

Corona charging: -6.0 kV V ₀ : surface potential (v) V _res : residual potential (v) E _1/2 : electrophotographic sensitivity (μJ / cm ² ) at 600 nm (C1 and D1) at 550 nm Electrophotographic sensitivity (μJ / cm ² ) (C2, C3, D2 and D3) Electrophotographic sensitivity (μJ / cm ² ) at 450nm (C4 and D
4) D. D: Dark decay rate (%)

As shown in Table 1, the instant two-layer type electrophotographic photoreceptor prepared from the pigment precursor has improved electrophotographic characteristics as compared to the conventional pigment-dispersed photoreceptor.

[0225]

[Table 6]

Corona charging: +6.0 kV V ₀ : Surface potential (v) V _res : Residual potential (v) E _1/2 : Electrophotographic sensitivity (μJ / cm ² ) at 600 nm (C5 and D5) at 550 nm Electrophotographic sensitivity (μJ / cm ² ) (C6, C7, D26 and D7) Electrophotographic sensitivity (μJ / cm ² ) at 450 nm (C8 and D
8) D. D: Dark decay rate (%)

As shown in Table 2, the instant single layer type electrophotographic photoreceptor prepared from the pigment precursor has improved electrophotographic characteristics as compared with the conventional photoreceptor in which the pigment is dispersed.

[0228]

[Table 7]

Corona potential: -6.0 kV Time: Grinding time (h) V ₀ : Surface potential (v) V _res : Residual potential (v) E _1/2 : Electrophotographic sensitivity at 550 nm (μJ / cm ² ). D. D: Dark decay rate (%)

As shown in Table 3, the resinified pigment prepared from the pigment precursor disperses into the photosensitive layer of the high-sensitivity electrophotographic photoreceptor faster than the conventional resinized pigment. Shorter dispersion (grinding) times are required until the same residual potential is reached.

Claims (21)

[Claims] 1. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer containing an organic pigment as a charge generating material, wherein the organic pigment is formed from a soluble organic pigment precursor. Electrophotographic photoreceptor. 2. The pigment precursor has the formula (I):(Wherein, x is an integer of 0 to 4; A is perylenes, quinacridones, azo compounds, a
Ntraquinones, phthalocyanines, dioxazines,
Isoindolinones, isoindolins, indigo,
Of chromophores that are quinophthalones or pyrrolopyrroles
Is a residue, and the residue of this chromophore is D₁ Radical and x D₂ Base
Having from 1 to 5 N atoms attached to
Each atom, independently of the others, contains 0, 1 or 2 D₁ 
Group or D₂ Bound to a group; ・ D₁ And D₂ Are independently of each other the formula (IIa), the formula
(IIb), Formula (IIc) or Formula (IId):(In the formula, m, n and p are each independently 0 or 1.
R; X is C₁ ~ C₁₄Alkylene group or C₂ ~ C₈ A
Represents a rukenylene group; Y represents -T₁ -(CH₂)_q -Group
(Where q is an integer from 1 to 6 and T₁ Is C₃ ~ C₆ 
Is a cycloalkylene group of); Z is -T₁ −
(CH₂)_r A group (where r is an integer from 0 to 6 and T
₁ Represents the same as above); R₁ And R₂ Are independent of each other
, Hydrogen atom, C₁ ~ C₆ Alkyl group, C₁ ~ C_Four Al
Coxy group, halogen atom, cyano group, nitro group or C
₁ ~ C_Four Alkyl, C₁ ~ C_Four Alkoxy or halo
A phenyl group or a phenyl group, which may be substituted with gen.
Represents a nonoxy group; R₃ And R_Four Independently of each other, hydrogen
Atom, C₁ ~ C₁₈Alkyl group or formula:(In the formula, X, Y, R₁ , R₂ , M and n are the same as above
D) represents a group; or R₃ And R_Four Is it
Together with the N atom to which they are bonded, a pyrrolidinyl group, pipette
Forms a lysinyl group or a morpholinyl group; Q₁ Is water
Elementary atom, cyano group, Si (R₁)₃ Group, -C (R_Five) (R₆)
(R₇) Group (where R_Five Is halogen and R₆ And R₇ 
Are each independently a hydrogen atom or a halogen),
Formula:(In the formula, R₁ And R₂ Is the same as above), -S
O₂ R₈ Group or -SR₈ Group (where R₈ Is C₁ ~
C_Four Alkyl), -CH (R₉)₂ Group (where R
₉ Is C₁ ~ C_Four Alkyl, C₁ ~ C_Four Alkoxy
Phenyl group, which may be substituted with halogen or halogen
Is a phenoxy group) or the formula:[Chemical 6]Represents a group represented by; Q₂ Has the formula:(In the formula, R_TenAnd R₁₁Are, independently of each other, a hydrogen atom, C₁ ~ C_{twenty four}
Alkyl group, O, S or NR₁₈The carbon chain
C refused₁ ~ C_{twenty four}Alkyl group, C₃ ~ C_{twenty four}Alkenyl
Group, C₃ ~ C_{twenty four}Alkynyl group, C_Four ~ C₁₂Cycloalkyl
Group, C_Four ~ C₁₂A cycloalkenyl group or unsubstituted
Or C₁ ~ C₆ Alkyl, C₁~ C₆ Arcoki
Substituted with Si, halogen, cyano or nitro
Represents a phenyl group or a biphenyl group; R₁₂, R
₁₃And R₁₄Independently of one another, hydrogen, C₁ ~ C_{twenty four}A
Rukiru group or C₃ ~ C_{twenty four}Represents an alkenyl group; R
_FifteenIs hydrogen, C₁ ~ C_{twenty four}Alkyl group, C₃ ~ C_{twenty four}Arche
Nyl group or formula:Represents a group represented by R;₁₆And R₁₇Are independent of each other,
Hydrogen atom, C₁ ~ C₆ Alkyl group, C₁ ~ C₆ Arcoki
Si group, halogen, cyano group, nitro group, N (R₁₈) (R
₁₉) Groups or unsubstituted or halogen, cyan
No, Nitro, C₁ ~ C₆ Alkyl or C₁ ~ C₆ A
Represents a phenyl group substituted with lucoxy; R₁₈And
And R₁₉Are, independently of each other, C₁ ~ C₆ Is an alkyl group
R; R₂₀Is hydrogen or C₁ ~ C₆ An alkyl group;
And R_{twenty one}Is hydrogen, C₁ ~ C₆ Alkyl group or non-substituted
Substitution or C₁ ~ C ₆ Substituted with alkyl
A phenyl group) which is a group represented by
A group) or a derivative thereof,
The electrophotographic photosensitive member according to claim 1. 3. In the formula (I), x is 0 or 1, and the D ₁ group and the D ₂ group are the formula (IIIa), the formula (IIIb),
Formula (IIIc) or Formula (IIId): (In the formula, m is 0 or 1; X ₁ is a C ₁ -C ₄ alkylene group or a C ₂ -C ₅ alkenylene group; R ₂₂ and R ₂₃ are, independently of each other, hydrogen, C ₁ -C ₄ alkyl group, a methoxy group, chloro or nitro; Q ₃ is
Hydrogen, cyano group, trichloromethyl group, formula: Is a group represented by, a —SO ₂ CH ₃ group or a —SCH ₃ group; R ₂₄ and R ₂₅ are independently of each other hydrogen, C ₁
To C ₄ alkyl groups or formulas: Or R ₂₄ and R ₂₅ together with the N atom to which they are attached form a piperidinyl group; and Q ₄ is of the formula: (In the formula, R _{24 to} R ₂₈ are independently of each other hydrogen or C _{1 to} C _12;
An alkyl group; R ₂₉ is hydrogen, a C ₁ -C ₁₂ alkyl group or a compound of the formula: The electrophotographic photosensitive member according to claim 2, wherein R ₃₀ represents a group represented by: or R ₃₀ represents a group represented by hydrogen or a C ₁ -C ₄ alkyl group). 4. In the formula (I), x is 1 and D ₁
And groups in which D ₂ is the same: The electrophotographic photosensitive member according to claim 3, which is a group represented by: 5. The compound of formula (I) has the formula (IVa) or (IVb): (In the formula, D ₃ is a hydrogen atom, a C ₁ -C ₆ alkyl group, a phenyl group which is unsubstituted or substituted with halogen or C ₁ -C ₄ alkyl, a benzyl group, a phenethyl group or a D ₁ group. The electrophotographic photosensitive member according to claim 2, which is a perylenecarboximide represented by 6. A compound of formula (I) has the formula (V): (In the formula, R ₃₁ and R ₃₂ are independently of each other, a hydrogen atom, a halogen atom, a C _{1 to} C ₁₈ alkyl group, and a C _{1 to} C ₄
The electrophotographic photoreceptor according to claim 2, which is an alkoxy group or a phenyl group; E is a hydrogen atom or a D ₁ group, but at least one E is a D ₁ group). 7. A compound of formula (I) has the formula (VI): (In the formula, R ₃₃ is a hydrogen atom, a halogen atom or C ₁ to C.
_The electrophotographic photosensitive member according to claim 2, which is a dioxazine represented by ₁₈ alkyl group; E is a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group). 8. A compound of formula (I) is a compound of formula (VIIa), formula (V)
IIb) or formula (VIIc): (In the formula, R ₃₄ is represented by the formula: Represents a group represented by: R ₃₅ is a hydrogen atom, a C ₁ -C ₁₈ alkyl group, a benzyl group, or a compound represented by the formula: Represents a group represented by: R ₃₆ and R ₃₇ independently of each other, a hydrogen atom, a C _{1 to} C ₁₈ alkyl group, and a C ₁ to
A C ₄ alkoxy group, a halogen atom or a trifluoromethyl group; E represents a hydrogen atom or a D ₁ group, but at least one E is a D ₁ group). 2. The electrophotographic photosensitive member according to 2. 9. A compound of formula (I) has the formula (VIII): (In the formula, R ₃₈ represents a hydrogen atom, a cyano group, a C ₁ -C ₄ alkyl group, a C ₁ -C ₄ alkoxy group or a halogen atom; E represents a hydrogen atom or a D ₁ group, but at least one The electrophotographic photosensitive member according to claim 2, wherein E is an indigo group represented by D ₁ group). 10. A compound of formula (I) has the formula (IX): (Wherein, R ₃₉ and R _40, independently of one another, a hydrogen atom, a halogen atom, C ₁ -C ₄ alkyl or C ₁ ~
The electrophotographic photosensitive material according to claim 2, which is an azobenzimidazolone group represented by C ₄ alkoxy group; E represents a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group). body. 11. A compound of formula (I) has the formula (X): The electrophotographic photosensitive member according to claim 2, which is an anthraquinoid compound represented by the formula (wherein E represents a hydrogen atom or a D ₁ group, but at least one E is a D ₁ group). 12. A compound of formula (I) has the formula (XI): (In the formula, M ₁ represents H ₂ , Zn, Cu, Ni, Fe, Ti (O) or V (O); X ₂ represents —CH (R ₄₂ ) — or —SO ₂ —; R ₄₁ is a hydrogen atom, C ₁ -C ₄ alkyl _{group, N (E) R 42,} -NHCOR 43, -COR 43 or formula: 25] Wherein R ₄₂ represents a hydrogen atom or a C ₁ -C ₄ alkyl group; R ₄₃ represents a C ₁ -C ₄ alkyl group; R ₄₄ represents a hydrogen atom or a halogen atom. Or represents a C ₁ -C ₄ alkoxy group; z is 0 or 1, y is an integer of 1 to 4; E is a hydrogen atom or D ₁
The electrophotographic photosensitive member according to claim 2, which is a phthalocyanine group represented by a group, wherein at least one E is a D ₁ group. 13. A compound of formula (I) has the formula (XII): Where G ₃ and G ₄ , independently of each other, are of the formula: (In the formula, R ₄₅ and R ₄₆ are independently of each other hydrogen, halogen,
C ₁ -C ₁₈ alkyl group, C ₁ -C ₁₈ alkoxy group, C ₁
To C ₁₈ alkylmercapto group, C _{1 to} C ₁₈ alkylamino group, cyano group, nitro group, phenyl group, trifluoromethyl group, C _{5 to} C ₆ cycloalkyl group, —CH═N
A-(C ₁ -C ₁₈ alkyl) group, formula: A group represented by an imidazolyl group, a pyrazolyl group, a triazolyl group, a piperazinyl group, a pyrrolyl group, oxazolyl group, benzoxazolyl group, benzothiazolyl group, benzoimidazolyl group, a morpholinyl group, a piperidinyl group or pyrrolidinyl group; T ₂ is -CH ₂ -, - C
_{H (CH 3) -, -} C (CH 3) 2 -, - CH = N -, - N
= N -, - O -, - S -, - SO -, - SO 2 - or -NR ₅₁ - represents; R ₄₇ and R ₄₈ are, independently of one another, hydrogen, halogen, C ₁ -C ₆ Alkyl group, C ₁ -C
₁₈ represents an alkoxy group or a cyano group; R ₄₉ and R ₅₀
Independently of one another, hydrogen, halogen or C ₁ -C ₆
Represents an alkyl group; R ₅₁ represents hydrogen or a C ₁ -C ₆ alkyl group; E represents a hydrogen atom or a D ₁ group, and at least one E is a D ₁ group); The electrophotographic photoreceptor according to claim 2, which is a pyrrolo [3,4-c] pyrrole represented by 14. A compound of formula (I) is represented by formula (XIIIa) or formula (XIIIb): (In the formula, R ₅₂ , R ₅₃ , R ₅₄ and R ₅₅ each independently represent hydrogen, a C _{1 to} C ₁₈ alkyl group, a C _{1 to} C ₄ alkoxy group, a halogen or a trifluoromethyl group) The electrophotographic photoreceptor according to claim 2, which is an isoindolinone represented by 15. In the formula (XII), G ₃ and G ₄
Independently of one another, the formula: [Chemical 31] (In the formula, R ₅₆ and R ₅₇ are independently of each other hydrogen, chloro, bromo, a C ₁ -C ₄ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkylamino group, a cyano group. Or represents a phenyl group; T ₃ is —O—, —NH—, —N
_{(CH 3) -, - N} (C 2 H 5) -, - N = N- or -S
The electrophotographic photosensitive member according to claim 13, which is a group represented by O ₂ —. 16. In formula (XII), G ₃ and G ₄
Are each represented by the formula: (Wherein R ₅₈ and R ₅₉ independently of each other represent hydrogen, methyl group, t-butyl group, chloro, bromo, cyano group or phenyl group).
The electrophotographic photosensitive member described. 17. The pigment precursor has the formula (XIV): (In the formula, L ₁ and L ₂ are independently of each other halogen, a C ₁ -C ₁₈ alkoxy group, a C ₂ -C ₁₈ dialkylamino group, a C ₁ -C ₁₈ cycloalkylamino group, (N′-
2. A C ₁ -C ₆ alkyl) piperidino group or a morpholino group, and M ₂ represents two hydrogen or at least a divalent metal or an oxo metal) or a derivative thereof. body. 18. In the formula (XIV), M ₂ is H ₂ , Z
n, Cu, Ni, Fe, Ti (O) or V (O), wherein L ₁ and L ₂ are each independently of each other a C ₂ -C ₁₈ dialkylamino group, C ₁ -C ₁₈ cycloalkylamino. Group, a (N′-C ₁ -C ₆ alkyl) piperidino group or a morpholino group, or a phenyl group of which is 1 to
The electrophotographic photoreceptor according to claim 17, which is a derivative thereof substituted with 16 bromo or chloro groups. 19. The method for producing an electrophotographic photosensitive member according to claim 1, wherein (1) a step of forming a layer containing a soluble organic pigment precursor on a conductive support; and (2) a soluble organic pigment. A method comprising chemically regenerating a charge generating organic pigment from a pigment precursor. 20. The pigment precursor is the compound according to claim 2 or 17, and (a) 50 together with an inorganic acid or an organic acid.
20. The method according to claim 19, wherein the pigment is returned to the pigment by heating to 150 ° C to 150 ° C and then cooling to 30 ° C or lower, or (b) heating to 120 to 350 ° C in the absence of an acid. 21. Use of the electrophotographic photosensitive member according to claim 1 in an electrophotographic method.