JP2010282074A - Photoelectric conversion element manufacturing method, image forming apparatus, image forming method, and process cartridge for image forming apparatus - Google Patents

Abstract

［但し、式（Ｉ）中、Ａはアゾ化合物の残基であり、Ｅ基は独立してＨ（水素原子）または次式で示されるカルボエステル基を表わす。］

［但し、式（ａ）中、Ａは一般式（Ｉ）と同義であり、Ｈは水素原子を表わし、ｎは、１から９の整数である。］
【選択図】図１Provided are a photoelectric conversion element, an image forming apparatus, an image forming method, and a process cartridge capable of improving the productivity of a charge generation layer and realizing high image quality and high speed of an electrophotographic apparatus.
A coating solution containing at least an azo compound having a carboester group represented by the following general formula (I) is applied and then decarboesterified to form an azo compound represented by the following general formula (a). A method for producing a photoelectric conversion element, comprising converting.

[In the formula (I), A represents a residue of an azo compound, and the E group independently represents H (hydrogen atom) or a carboester group represented by the following formula. ]

[In the formula (a), A is as defined in the general formula (I), H represents a hydrogen atom, and n is an integer of 1 to 9. ]
[Selection] Figure 1

Description

  The present invention relates to a photoelectric conversion element containing at least an azo pigment useful as a photoconductor, and more particularly to a method for producing an electrophotographic photoreceptor used in electrophotography.

Conventionally, certain azo pigments are known to be useful as organic photoconductors for electrophotographic photoreceptors (hereinafter also referred to as photoreceptors), particularly as charge generating pigments.
As is known in the art, a multilayer photoconductor includes a charge generation layer mainly composed of a charge generation pigment having the ability to generate charge carriers by light on a conductive support, and a charge on the charge generation layer. The photoconductor is configured to include a charge transport layer mainly composed of a charge transport material capable of efficiently injecting charge carriers generated in the generation layer and transporting the charge carriers.

Conventionally, examples of the azo pigment used in such a photoreceptor include benzidine described in Patent Document 1 (Japanese Patent Laid-Open No. 47-37543), Patent Document 2 (Japanese Patent Laid-Open No. 52-55643), and the like. Bisazo pigments, stilbene bisazo pigments described in JP-A-52-8832, diphenylhexatriene-based bisazo pigments described in JP-A-58-222152, patent documents No. 5 (Japanese Patent Laid-Open No. 58-222153) and the like are known.
However, photoreceptors using these azo pigments alone have problems such as a narrow photosensitive wavelength range and low sensitivity, and fluctuations in photoreceptor characteristics depending on the usage environment. It is insufficient as a charge generating pigment for use in a photoreceptor for electrophotographic apparatus (for high speed copying machines, laser printers, etc.).

In order to solve these problems, when a charge generating pigment is used in a photoreceptor, for example, a method in which a metal-free phthalocyanine and a fluorenone-based azo pigment are mixed and contained (Japanese Patent No. 3326706, Patent Document 6) No. 7, JP-A-2001-290296), a method of mixing and containing a phthalocyanine compound and an azo pigment (see JP-A-9-127711 of Patent Document 8), a method of mixing and containing metal phthalocyanine and perylene. (See JP 2002-23399 of Patent Document 9), a method of mixing and containing a quinacridone pigment and a titanyl phthalocyanine pigment (see JP 2007-334099 of Patent Document 10), a titanyl phthalocyanine pigment and the others Method of mixing and containing phthalocyanine pigment Publication reference), etc. No. 3-9962, a method using a mixture of 2 or more pigments have been proposed.
However, the pigment configurations described in Patent Documents 6 to 11 have not yet been sufficient as those that can cope with higher image quality and higher speed.
One reason for this is that the pigments described in Patent Documents 6 to 11 generally have very low solubility in organic solvents, and purification is limited to washing steps using organic solvents, and impurities cannot be sufficiently removed. it is conceivable that. In addition, the pigment mixing method mainly uses mechanical means such as milling, and such a method cannot mix and combine the pigment components at the molecular level, so that the function as an organic photoconductor is sufficient. It is thought that it cannot be demonstrated. In addition, although a method using an acid paste is also proposed, there are problems in production because concentrated sulfuric acid is used, and there are also problems that application to pigments is limited.

Furthermore, in order to obtain preferable electrophotographic photoreceptor characteristics, milling, which is a mechanical means, is generally used as a method for converting a charge generating pigment into a desired crystal form. However, in many cases, it is desired to improve the productivity of the charge generation layer in the production of an electrophotographic photosensitive member. Yes.
Furthermore, the dispersion stability of the dispersion after adjusting the crystal form is also a problem, and from the viewpoint of the stability of the photoreceptor characteristics, there is a demand for a charge generating pigment dispersion that can be stored for a long period of time. It is.
Japanese Patent Application Laid-Open No. 2009-7523 of Patent Document 12 describes B- (N = N-Cp) m (E) n.
(Here, B represents the main skeleton of the azo compound, Cp represents a coupler component residue, m represents an integer of 2 or 3, and E groups each independently represent a hydrogen atom or a carboester group —C (═O ) -OR1 (R1 represents a C4-C10 substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, or aralkyl group), and n represents an integer of 1-10) As an application example of the compound, the azo compound charge transporting material and the triphenylamine-based charge transporting material p- (N, N-bis-p'-tolyl) amino-2-phenyl-stilbene are dissolved and a Z-type polycarbonate is further dissolved. Ball milled cyclohexahydrate containing dissolved tetrahydrofuran solution and metal-free phthalocyanine pigment (Fastogen Blue 8120B manufactured by Dainippon Ink Industries, Ltd.) as charge generation material The photosensitive layer coating solution consisting of the emission dispersion was applied and dried, it is described that to manufacture an electrophotographic photosensitive member.
Under such circumstances, there is a demand for an electrophotographic photoreceptor using a composite azo pigment useful as an organic photoconductor that overcomes the disadvantages of the prior art, and the production thereof. The soluble pigment precursor is publicly known (for example, see Japanese Patent Application Publication No. 2001-513119 of Patent Document 13), but it is known to improve the function by compounding as in the present invention. Absent.

  The present invention has been made in view of the above circumstances, and its purpose is to improve the productivity of the charge generation layer and to improve the image quality and speed of an electrophotographic apparatus (image forming apparatus such as a copying machine or a laser printer). An object of the present invention is to provide a photoelectric conversion element that can be realized, an image forming apparatus using the photoelectric conversion element, an image forming method using the photoelectric conversion element, a process cartridge for the image forming apparatus using the photoelectric conversion element, and a manufacturing method thereof.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the inventions described in the following (1) to (18), and have reached the present invention.
(1) “After applying a coating solution composed of a plurality of charge generation materials containing at least an azo compound having a carboester group represented by the following general formula (I), decarboesterification is carried out, whereby the following general formula (a The method for producing a photoelectric conversion element is characterized in that it is converted into an azo compound represented by the formula:

［但し、式（Ｉ）中、Ａはアゾ化合物の残基であり、この残基Ａは、１つまたはそれ以上のヘテロ原子を介してｎ個のＥ基に結合しており、そしてこれらのヘテロ原子は、ＮおよびＯからなる群から選ばれ、残基Ａの一部を形成しており、Ｅ基は独立してＨ（水素原子）または次式で示されるカルボエステル基：−Ｃ（＝Ｏ）−Ｏ−Ｒ^１〔式中Ｒ^１は、炭素数４から１０の置換または非置換のアルキル基、アルケニル基、アルキニル基、シクロアルキル基、シクロアルケニル基、またはアラルキル基を表わす。〕を表わす。但し、Ｅ基の全てが同時に水素原子であることはない。ｎは、１から９の整数である。］

[Wherein, in formula (I), A is a residue of an azo compound, and this residue A is bonded to n E groups via one or more heteroatoms, and The heteroatom is selected from the group consisting of N and O and forms part of the residue A, and the E group is independently H (hydrogen atom) or a carboester group represented by the following formula: —C ( ═O) —O—R ¹ [wherein R ¹ represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group having 4 to 10 carbon atoms. ]. However, not all E groups are hydrogen atoms at the same time. n is an integer from 1 to 9. ]

［但し、式（ａ）中、Ａは一般式（Ｉ）と同義であり、Ｈは水素原子を表わし、ｎは、１から９の整数である。］」、
（２）「前記複数の電荷発生材料のうちの他方（前記カルボエステル基含有アゾ化合物以外）の電荷発生材料が、フタロシアニン系顔料、アゾ顔料、縮合多環系顔料、フラーレン、あるいはカーボンナノチューブの群から選ばれることを特徴とする前記第（１）項に記載の光電変換素子の製造方法。」、
（３）「前記一般式（Ｉ）で示されるカルボエステル基を有するアゾ化合物を有機溶剤に溶解し、その溶液をシリカゲル、アルミナ、フロリジル、活性炭素、活性白土、珪藻土、またはパーライトで吸着処理をした後、化学的手段、熱的手段または光分解的手段を用いて脱カルボエステル化することにより、前記一般式（ａ）で示されるアゾ化合物に変換することを特徴とする前記第（１）項乃至第（２）項のいずれかに記載の光電変換素子の製造方法」、
（４）「前記カルボエステル基を有するアゾ化合物を脱カルボエステル化する際に、熱的手段を用いることを特徴とする前記第（１）項乃至第（３）項のいずれかに記載の光電変換素子の製造方法」、
（５）「前記カルボエステル基を有するアゾ化合物を脱カルボエステル化する際に、熱的手段と化学的手段を併用することを特徴とする前記第（１）項乃至第（４）項のいずれかに記載の光電変換素子の製造方法」、
（６）「前記一般式（Ｉ）および前記一般式（ａ）中のＡが、下記一般式（II）で示されるアゾ化合物の残基であることを特徴とする前記第（１）項乃至第（５）項のいずれかに記載の光電変換素子の製造方法。

[In the formula (a), A is as defined in the general formula (I), H represents a hydrogen atom, and n is an integer of 1 to 9. ] ",
(2) “The other of the plurality of charge generation materials (other than the carboester group-containing azo compound) is a phthalocyanine pigment, azo pigment, condensed polycyclic pigment, fullerene, or carbon nanotube group. The method for producing a photoelectric conversion element according to item (1), which is selected from the group consisting of:
(3) “The azo compound having a carboester group represented by the general formula (I) is dissolved in an organic solvent, and the solution is adsorbed with silica gel, alumina, florisil, activated carbon, activated clay, diatomaceous earth, or perlite. Then, the azo compound represented by the general formula (a) is converted by decarboesterification using a chemical means, a thermal means or a photolytic means. The manufacturing method of the photoelectric conversion element in any one of a term thru | or a term (2) ",
(4) The photoelectric device according to any one of (1) to (3), wherein a thermal means is used when decarboxylating the azo compound having a carboester group. Manufacturing method of conversion element ",
(5) Any one of the above items (1) to (4), wherein thermal means and chemical means are used in combination when decarboxylating the azo compound having a carboester group. The manufacturing method of the photoelectric conversion element as described in "
(6) “Items (1) to (1)” wherein A in the general formula (I) and the general formula (a) is a residue of an azo compound represented by the following general formula (II): The manufacturing method of the photoelectric conversion element in any one of the (5) term.

［但し、式（II）中、Ｂはアゾ化合物の主骨格を示し、Ｃｐはカップラー成分残基であり、ｍは２または３の整数を表わす。］」、
（７）「前記一般式（II）中のＣｐが、下記一般式（１）乃至（９）の少なくともいずれかで示されるカップラー成分残基であることを特徴とする前記第（６）項に記載の光電変換素子の製造方法。

[In the formula (II), B represents the main skeleton of the azo compound, Cp represents a coupler component residue, and m represents an integer of 2 or 3. ] ",
(7) In the above item (6), Cp in the general formula (II) is a coupler component residue represented by at least one of the following general formulas (1) to (9) The manufacturing method of the photoelectric conversion element of description.

［但し、式（１）〜（４）中、Ｘ、Ｙ^１、Ｚ、ｐおよびｑはそれぞれ以下のものを表わす。
Ｘ：−ＯＨ、−Ｎ（Ｒ^１）（Ｒ^２）または−ＮＨＳＯ_２−Ｒ^３（但し、ここで、Ｒ^１およびＲ^２は水素原子または置換もしくは無置換のアルキル基を表わし、Ｒ^３は置換もしくは無置換のアルキル基または置換もしくは無置換のアリール基を表わす。）、
Ｙ^１：水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシ基、スルホン基、置換もしくは無置換のスルファモイル基または−ＣＯＮ（Ｒ^４）（Ｙ^２）｛Ｒ^４は水素原子、アルキル基もしくはその置換体またはフェニル基もしくはその置換体を表わし、Ｙ^２は炭化水素環基もしくはその置換体、複素環基もしくはその置換体、または−Ｎ＝Ｃ（Ｒ^５）（Ｒ^６）〔但し、Ｒ^５は炭化水素環基もしくはその置換体、複素環基もしくはその置換体またはスチリル基もしくはその置換体、Ｒ^６は水素原子、アルキル基またはフェニル基もしくはその置換体を表わすか、あるいはＲ^５およびＲ^６はそれらに結合する炭素原子と共に環を形成してもよい。〕を示す。｝、
Ｚ：炭化水素環もしくはその置換体または複素環もしくはその置換体、
ｐ：１または２の整数、ｑ：１または２の整数。］

[However, in the formulas (1) to (4), X, Y ¹ , Z, p and q each represent the following.
X: —OH, —N (R ¹ ) (R ² ) or —NHSO ₂ —R ³ (wherein R ¹ and R ² represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R ³ represents A substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group).
Y ¹ : a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or unsubstituted sulfamoyl group, or —CON (R ⁴ ) (Y ² ) { R ⁴ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or —N═C (R ⁵ ) (R ⁶ ) [wherein R ⁵ is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, and R ⁶ is a hydrogen atom, an alkyl group, a phenyl group or a substituted product thereof. Or R ⁵ and R ⁶ may form a ring together with carbon atoms bonded to them. ] Is shown. },
Z: a hydrocarbon ring or a substituted product thereof, or a heterocyclic ring or a substituted product thereof,
p: an integer of 1 or 2, q: an integer of 1 or 2. ]

［但し、式（５）中、Ｒ^７は置換もしくは無置換の炭化水素基を表わし、Ｘは前記と同じである。］

[In the formula (5), R ⁷ represents a substituted or unsubstituted hydrocarbon group, and X is the same as defined above. ]

［但し、式（６）中、Ａは、式（６）中に記載された２個のＮ原子と共にＮ含有ヘテロ環を形成するに必要な芳香族炭化水素の２価基または窒素原子を環内に含むヘテロ原子含有の２価基を表わす（これらの環は置換または無置換でもよい）。Ｘは前記と同じである。］

[In the formula (6), A represents a ring of a divalent aromatic hydrocarbon group or a nitrogen atom necessary for forming an N-containing heterocycle together with the two N atoms described in the formula (6). Represents a divalent group containing a hetero atom contained therein (these rings may be substituted or unsubstituted). X is the same as described above. ]

［但し、式（７）中、Ｒ^８はアルキル基、カルバモイル基、カルボキシ基またはそのエステルを表わし、Ａｒ^１は炭化水素環基またはその置換体を表わし、Ｘは前記と同じである。］

[In the formula (7), R ⁸ represents an alkyl group, a carbamoyl group, a carboxy group or an ester thereof, Ar ¹ represents a hydrocarbon ring group or a substituent thereof, and X is the same as defined above. ]

［但し、式（８）および（９）中、Ｒ^９は水素原子または置換もしくは無置換の炭化水素基を表わし、Ａｒ^２は炭化水素環基またはその置換体を表わす。但し、同時にＲ^９が水素原子でかつＡｒ^２がシクロアルキル基またはシクロアルケニル基になることはない。］」、
（８）「前記一般式（II）中のＢが、下記一般式（III）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formulas (8) and (9), R ⁹ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and Ar ² represents a hydrocarbon ring group or a substituted product thereof. However, at the same time, R ⁹ is not a hydrogen atom and Ar ² is not a cycloalkyl group or a cycloalkenyl group. ] ",
(8) The method for producing a photoelectric conversion element according to (6) or (7), wherein B in the general formula (II) is represented by the following general formula (III): .

［但し、式（III）中、Ｒ^１１、Ｒ^１２は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（９）「前記一般式（II）中のＢが、下記一般式（IＶ）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (III), R ¹¹ and R ¹² independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. ] ",
(9) “The method for producing a photoelectric conversion element according to the item (6) or (7), wherein B in the general formula (II) is represented by the following general formula (IV): .

［但し、式（IＶ）中、Ｒ^１３、Ｒ^１４、Ｒ^１５は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１０）「前記一般式（II）中のＢが、下記一般式（Ｖ）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (IV), R ¹³ , R ¹⁴ , and R ¹⁵ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. Represent. ] ",
(10) The method for producing a photoelectric conversion element according to the item (6) or (7), wherein B in the general formula (II) is represented by the following general formula (V): .

［但し、式（Ｖ）中、Ｒ^１６、Ｒ^１７、Ｒ^１８は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１１）「前記一般式（II）中のＢが、下記一般式（ＶI）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[However, in the formula (V), R ¹⁶ , R ¹⁷ and R ¹⁸ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] ",
(11) “The method for producing a photoelectric conversion element according to (6) or (7), wherein B in the general formula (II) is represented by the following general formula (VI): .

［但し、式（ＶI）中、Ｒ^１９、Ｒ^２０は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１２）「前記一般式（II）中のＢが、下記一般式（ＶII）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (VI), R ¹⁹ and R ²⁰ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. ] ",
(12) The method for producing a photoelectric conversion element according to (6) or (7), wherein B in the general formula (II) is represented by the following general formula (VII): .

［但し、式（ＶII）中、Ｒ^２１、Ｒ^２２、Ｒ^２３は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１３）「前記一般式（II）中のＢが、下記一般式（ＶIII）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (VII), R ²¹ , R ²² and R ²³ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] ",
(13) The process for producing a photoelectric conversion element according to (6) or (7), wherein B in the general formula (II) is represented by the following general formula (VIII): .

［但し、式（ＶIII）中、Ｒ^２４、Ｒ^２５、Ｒ^２６は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１４）「前記一般式（II）中のＢが、下記一般式（IＸ）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (VIII), R ²⁴ , R ²⁵ and R ²⁶ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] ",
(14) The method for producing a photoelectric conversion element according to the item (6) or (7), wherein B in the general formula (II) is represented by the following general formula (IX): .

［但し、式（IＸ）中、Ｒ^２７、Ｒ^２８、Ｒ^２９は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１５）「前記一般式（II）中のＢが、下記一般式（Ｘ）で示されることを特徴とする前記第（６）項または第（７）項に記載の光電変換素子の製造方法。

[In the formula (IX), R ²⁷ , R ²⁸ , and R ²⁹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. Represent. ] ",
(15) “The method for producing a photoelectric conversion element according to (6) or (7), wherein B in the general formula (II) is represented by the following general formula (X): .

［但し、式（Ｘ）中、Ｒ^３０、Ｒ^３１は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。］」、
（１６）「前記第（１）項乃至第（１５）項に記載の光電変換素子と、少なくとも光電変換素子を帯電させる帯電器と、帯電器によって帯電させられた光電変換素子表面に静電潜像を形成する潜像形成器と、潜像形成器によって形成された静電潜像にトナーを付着させる現像器と、現像器よって形成されたトナー像を被転写体に転写させる転写器と、転写後に光電変換素子表面に残留したトナーを光電変換素子表面から除去するクリーニング器とを有する画像形成装置」、
（１７）「前記第（１）項乃至第（１５）項に記載の光電変換素子と、少なくとも光電変換素子を帯電させる帯電器と、帯電器によって帯電させられた光電変換素子表面に静電潜像を形成する潜像形成器と、潜像形成器によって形成された静電潜像にトナーを付着させる現像器と、現像器よって形成されたトナー像を被転写体に転写させる転写器と、転写後に光電変換素子表面に残留したトナーを光電変換素子表面から除去するクリーニング器とを有する画像形成方法」、
（１８）「前記第（１）項乃至第（１５）項に記載の光電変換素子と、少なくとも光電変換素子を帯電させる帯電器と、帯電器によって帯電させられた光電変換素子表面に静電潜像を形成する潜像形成器と、潜像形成器によって形成された静電潜像にトナーを付着させる現像器と、現像器よって形成されたトナー像を被転写体に転写させる転写器と、転写後に光電変換素子表面に残留したトナーを光電変換素子表面から除去するクリーニング器からなる群から選ばれた一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ」。

[In the formula (X), R ³⁰ and R ³¹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. ] ",
(16) “An electrostatic latent image is formed on the surface of the photoelectric conversion element according to the items (1) to (15), a charger for charging at least the photoelectric conversion element, and a surface of the photoelectric conversion element charged by the charger. A latent image forming device that forms an image, a developing device that attaches toner to the electrostatic latent image formed by the latent image forming device, a transfer device that transfers the toner image formed by the developing device to a transfer target, and An image forming apparatus having a cleaning device for removing toner remaining on the surface of the photoelectric conversion element after the transfer from the surface of the photoelectric conversion element ";
(17) “An electrostatic latent image is formed on the surface of the photoelectric conversion element described in the items (1) to (15), a charger for charging at least the photoelectric conversion element, and a surface of the photoelectric conversion element charged by the charger. A latent image forming device that forms an image, a developing device that attaches toner to the electrostatic latent image formed by the latent image forming device, a transfer device that transfers the toner image formed by the developing device to a transfer target, and An image forming method having a cleaning device for removing toner remaining on the surface of the photoelectric conversion element after the transfer from the surface of the photoelectric conversion element ";
(18) “The electrostatic conversion element according to the items (1) to (15)”, a charger for charging at least the photoelectric conversion element, and a surface on the surface of the photoelectric conversion element charged by the charger. A latent image forming device that forms an image, a developing device that attaches toner to the electrostatic latent image formed by the latent image forming device, a transfer device that transfers the toner image formed by the developing device to a transfer target, and It has one means selected from the group consisting of a cleaning device that removes toner remaining on the surface of the photoelectric conversion element after transfer from the surface of the photoelectric conversion element, and is detachable from the main body of the image forming apparatus. Process cartridge for image forming apparatus ".

The chemical means, thermal means and / or photolysis means after applying a coating solution comprising a plurality of charge generating material compositions comprising at least an azo compound having a carboester group represented by the general formula (I) of the present invention In a method for producing a photoelectric conversion element by converting to an azo compound represented by the general formula (a) by decarboesterification using a decarboesterification means such as the above, the general formula (I) Dispersion to adjust the crystal form by coating with a coating solution in which an azo compound having a carboester group represented by is dissolved in a solvent capable of dissolving, and then performing pigment formation by decarboesterification. The process can be omitted, and the productivity of the charge generation layer in the electrophotographic photosensitive member can be greatly improved.
Furthermore, since the azo compound is dissolved in the solvent, it does not exist in the form of a pigment, and the storage stability of the coating liquid can be significantly improved. Further, by controlling the conditions for decarboesterification, the pigment can be atomized and the crystal type can be optimized, and a highly sensitive electrophotographic photoreceptor can be realized.

In the present invention, a coating liquid composed of a plurality of charge generation material structures including at least an azo compound having a carboester group represented by the general formula (I) is used, and the azo compound represented by the general formula (I) is used. In the presence of other pigments and charge generation materials, dissolved in an organic solvent and brought into contact with other pigments in the molecular state, or at least two kinds of azo compounds represented by the general formula (I) A photoelectric conversion element is produced by decarboesterification using a chemical means, a thermal means or a photolytic means in a state of being dissolved in and mixed with. As the decarboesterification means, a thermal decomposition means can be used alone, or a photolytic means and / or a chemical decomposition means can be used in combination with the thermal decomposition means.
In other words, since the photoelectric conversion element of the present invention has two or more kinds of pigments bonded at the molecular level, it cannot be formed by mixing pigments by milling as known in the prior art. It is thought that high sensitivity and stable image quality were realized.
As a similar attempt, there is a method in which two or more pigments are mixed at the time of acid paste. However, in the case of pigments whose charge generation ability differs greatly depending on the crystal type, the desired crystal type cannot be obtained and sufficient sensitivity is obtained. In many cases, the azo pigment can be bonded to the desired crystal type pigment at the molecular level in the present invention, so that further enhancement of sensitivity can be realized.

It is also possible to cover the periphery of a certain pigment with an azo pigment represented by A (H) n in the formula (a) by controlling the conditions for decarboesterification.
In this case, depending on the pigment to be selected, the characteristics are not easily changed due to external factors, and a highly stable charge generating material is obtained. As a result, an electrophotographic image that is very highly stable against external factors such as temperature and humidity environment A photoreceptor can be obtained.

In addition, a major problem with charge generation layer coating liquids is the dispersion stability of pigments, which limits the formulation of pigments and charge generation layer coating liquids that can be used as charge generation materials. In some cases, characteristics were sacrificed.
However, the problem of dispersion stability can be solved by selecting an azo pigment having high dispersion stability and enclosing other pigments. As a result, charge generation materials that could not be used due to dispersion stability problems can be used, and the formulation of the coating solution for the charge generation layer can be designed with emphasis on the electrostatic characteristics of the photoconductor. Therefore, it has become possible to obtain an electrophotographic photosensitive member having characteristics that could not be realized so far.

  In addition, at least two kinds of the azo compounds represented by the general formula (I) are dissolved in an organic solvent and decarboesterified using chemical means, thermal means or photolytic means. When the charge generating pigment of the invention is obtained, since plural kinds of azo compounds coexist in the process of pigmentation, it is possible to suppress the crystal size growth depending on the reaction conditions. Those having a primary particle size smaller than that of the pigment can be synthesized, and as a result, a photosensitive material having high sensitivity can be obtained.

That is, in the manufacturing method of the present invention, a photoelectric conversion element capable of improving the productivity of the charge generation layer and realizing high image quality and high speed of an electrophotographic apparatus (image forming apparatus such as a copying machine or a laser printer), and It is possible to provide an image forming apparatus used, an image forming method using the same, a process cartridge for the image forming apparatus using the same, and a manufacturing method thereof.
The present invention has been made in view of the above circumstances, and its purpose is to improve the productivity of the charge generation layer and to improve the image quality and speed of an electrophotographic apparatus (image forming apparatus such as a copying machine or a laser printer). An object of the present invention is to provide a photoelectric conversion element that can be realized, an image forming apparatus using the photoelectric conversion element, an image forming method using the photoelectric conversion element, a process cartridge for the image forming apparatus using the photoelectric conversion element, and a manufacturing method thereof.

FIG. 3 is a diagram illustrating a layer configuration of an electrophotographic photosensitive member of the present invention. It is a figure showing the layer structure of another electrophotographic photosensitive member used for this invention. It is a figure showing the layer structure of another electrophotographic photosensitive member used for this invention. It is a figure showing the layer structure of another electrophotographic photosensitive member used for this invention. 1 is a diagram for explaining an electrophotographic process and an image forming apparatus of the present invention. It is a figure for demonstrating another electrophotographic process and image forming apparatus of this invention. It is a figure for demonstrating another electrophotographic process and image forming apparatus of this invention. FIG. 4 is a diagram for explaining a process cartridge for an image forming apparatus according to the present invention.

Next, the photoelectric conversion element of the present invention will be described below.
A photoelectric conversion element is an element that converts light energy into electric energy and an element that converts electric energy into light energy, and is often composed of a pn junction of an inorganic semiconductor. Application examples such as electroluminescence elements, organic solar cells, and organic photoreceptors in the field of electrophotography have been realized.
Some of the azo compounds represented by the general formula (I) and the general formula (a) of the present invention are used as n-type semiconductors having electron mobility, and are locally produced by using the production method of the present invention. It is possible to obtain a uniform n-type semiconductor layer with no uneven thickness.
The azo compound represented by the general formula (a) is well known as a charge generation material that functions as a charge generation material in an organic photoreceptor in the field of electrophotography, and an electrophotographic photoreceptor is used as the photoelectric conversion element of the present invention. Particularly preferred. However, the present invention is not limited to the method for producing an electrophotographic photoreceptor, and can be favorably used for other photoelectric conversion elements.

Next, the configuration of the electrophotographic photoreceptor will be described in detail below with reference to the drawings. As shown in FIG. 1, the photoreceptor (1) of the present invention comprises, on a conductive support (2), a charge generation layer (3) containing a charge generation material as a main component and a charge transport material as a main component. The charge transport layer (4) to be stacked is laminated.
As shown in FIG. 2, the photoreceptor (1) of the present invention has an undercoat layer (6) or an intermediate layer between the conductive support (2) and the charge generation layer (3). It may be formed.
In the photoreceptor (1) of the present invention, a protective layer (5) may be formed on the charge transport layer (4) as shown in FIG.
Further, as shown in FIG. 4, the photoreceptor (1) of the present invention has a single photosensitive layer (7) containing a charge generation substance and a charge transport substance on a conductive support (2). You may make the aspect of a layer type photoreceptor.

<Conductive support>
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. Metal oxide coated by film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc. After the conversion, a tube subjected to surface treatment such as cutting, superfinishing or polishing can be used. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.
In addition, those obtained by dispersing and coating conductive powder in an appropriate binder resin on the support can also be used as the conductive support of the present invention.
Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done.
The binder resin used at the same time includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine Thermoplastic, thermosetting resin or photo-curing resin such as resin, urethane resin, phenol resin, alkyd resin and the like can be mentioned.
Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.
Furthermore, a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as the conductive support of the present invention.

<Photosensitive layer>
Next, the photosensitive layer will be described.
The laminated photosensitive layer is constituted by sequentially laminating at least a charge generation layer and a charge transport layer.

<Charge generation layer>
The charge generation layer of the present invention comprises a coating solution prepared by dissolving a plurality of charge generation pigments and a binder resin containing at least an azo compound having a carboester group represented by the following general formula (I) on a conductive support, Alternatively, after coating on the undercoat layer or intermediate layer, it is converted to an azo compound represented by the following general formula (a) by decarboesterification using chemical means, thermal means or photolysis means. Manufactured.

［但し式（Ｉ）中、Ａはアゾ化合物の残基であり、この残基Ａは、１つまたはそれ以上のヘテロ原子を介してｎ個のＥ基に結合しており、そしてこれらのヘテロ原子は、ＮおよびＯからなる群から選ばれ、残基Ａの一部を形成しており、Ｅ基は独立してＨ（水素原子）または次式で示されるカルボエステル基；

[Wherein A is a residue of an azo compound, and this residue A is bonded to n E groups via one or more heteroatoms, and The atom is selected from the group consisting of N and O and forms part of the residue A; the E group is independently H (hydrogen atom) or a carboester group represented by the following formula;

[Wherein R ₁ represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group having 4 to 10 carbon atoms. ]. However, not all E groups are hydrogen atoms at the same time. n is an integer from 1 to 9. ]

［但し式（ａ）中、Ａは一般式（Ｉ）と同義であり、Ｈは水素原子を表わし、ｎは、１から９の整数である。］

[In the formula (a), A is as defined in the general formula (I), H represents a hydrogen atom, and n is an integer of 1 to 9. ]

Regarding the means for constituting a plurality of charge generating materials, the azo compound represented by the general formula (I) is decarboesterified using at least one of chemical means, thermal means and photolytic means. Thus, when converting to the azo compound represented by the general formula (a), another charge generation material may coexist.
Further, as a different means, two or more kinds of azo compounds represented by the above general formula (I) are decarboxylated by using at least one of chemical means, thermal means and photolytic means simultaneously or stepwise. Thus, a means for forming a plurality of pigments by converting into the azo compound represented by the general formula (a) is also preferably used.

  As an azo compound that can be preferably used in the present invention, A in the general formula (a) is an azo compound represented by the following general formula (II).

(B represents the main skeleton of the azo compound, Cp represents a coupler component residue, and m represents an integer of 2 or 3.)
More preferably, Cp in the general formula (II) is a coupler component residue represented by at least one of the following general formulas (1) to (9).

In the general formulas (1) to (4), X, Y ¹ , Z, p and q each represent the following. ^{X: -OH, -N (R 1} ) (R 2) or -NHSO ₂ -R ^3. (Where R ¹ and R ² represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R ³ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Y ¹ : hydrogen An atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or unsubstituted sulfamoyl group, or —CON (R ⁴ ) (Y ² ); [R ⁴ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or —N═C (R ⁵ ) (R ⁶ ) (where R ⁵ is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, and R ⁶ is a hydrogen atom, an alkyl group, a phenyl group or a substituted product thereof. Or R ⁵ and R ⁶ may form a ring together with the carbon atom to which they are attached. Z: A hydrocarbon ring or a substituted product thereof, or a heterocyclic ring or a substituted product thereof. p: an integer of 1 or 2. q: An integer of 1 or 2.

（上記一般式（５）中、Ｒ^７は置換もしくは無置換の炭化水素基を表わし、Ｘは前記と同じである。）

(In the general formula (5), R ⁷ represents a substituted or unsubstituted hydrocarbon group, and X is the same as described above.)

（上記一般式（６）中、Ａは、式（６）中に記載された２個のＮ原子と共にＮ含有ヘテロ環を形成するに必要な芳香族炭化水素の２価基または窒素原子を環内に含むヘテロ原子含有の２価基を表わす（これらの環は置換または無置換でもよい）。Ｘは前記と同じ。）

(In the general formula (6), A is a divalent aromatic hydrocarbon group or nitrogen atom necessary for forming an N-containing heterocycle together with the two N atoms described in the formula (6). Represents a divalent group containing a hetero atom contained therein (these rings may be substituted or unsubstituted. X is as defined above).

（上記一般式（７）中、Ｒ^８はアルキル基、カルバモイル基、カルボキシ基またはそのエステルを表わし、Ａｒ^１は炭化水素環基またはその置換体を表わし、Ｘは前記と同じである。）

(In the above general formula (7), R ⁸ represents an alkyl group, a carbamoyl group, a carboxy group or an ester thereof, Ar ¹ represents a hydrocarbon ring group or a substituent thereof, and X is the same as described above.)

（上記一般式（８）および（９）中、Ｒ^９は水素原子または置換もしくは無置換の炭化水素基を表わし、Ａｒ^２は炭化水素環基またはその置換体を表わす。但し、同時にＲ^９が水素原子でかつＡｒ^２がシクロアルキル基又はシクロアルケニル基になることはない。また、より好ましくは前記一般式（II）のＢが、下記一般式（III）〜（Ｘ）で示されるアゾ化合物である。

(In the above general formulas (8) and (9), R ⁹ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, Ar ² represents a hydrocarbon ring group or a substituted product thereof, provided that R ⁹ represents An azo compound in which Ar ² is a hydrogen atom and Ar ² does not become a cycloalkyl group or a cycloalkenyl group, and more preferably, B in the general formula (II) is represented by the following general formulas (III) to (X): It is.

（但し、Ｒ^１１，Ｒ^１２は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基またはそのエステルを表わす。）

(However, R ¹¹ and R ¹² independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof.)

（但し、Ｒ^１３，Ｒ^１４，Ｒ^１５は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ¹³ , R ¹⁴ , and R ¹⁵ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^１６，Ｒ^１７，Ｒ^１８は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ¹⁶ , R ¹⁷ , and R ¹⁸ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^１９，Ｒ^２０は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ¹⁹ and R ²⁰ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^２１，Ｒ^２２，Ｒ^２３は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ²¹ , R ²² , and R ²³ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^２４，Ｒ^２５，Ｒ^２６は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ²⁴ , R ²⁵ , and R ²⁶ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^２７，Ｒ^２８，Ｒ^２９は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ²⁷ , R ²⁸ , and R ²⁹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

（但し、Ｒ^３０，Ｒ^３１は独立して、水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、カルボキシル基及びそのエステルを表わす。）

(However, R ³⁰ and R ³¹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, and an ester thereof.)

  Preferred examples of the azo compound represented by the formula: A (H) n or A (E) n that can be used in the present invention include the formula (III) -1 in which the main skeleton of the azo compound is the general formula (III). To (III) -14, formulas (IV) -1 to (IV) -5 in which the main skeleton of the azo compound is the general formula (IV), and formula (V) in which the main skeleton of the azo compound is the general formula (V) V) -1 to (V) -8, formulas (VI) -1 to (VI) -5 in which the main skeleton of the azo compound is the general formula (VI), and the main skeleton of the azo compound is the general formula (VII). Formulas (VII) -1 to (VII) -7, wherein the main skeleton of the azo compound is General Formula (VIII), and the main skeleton of the azo compound is General Formulas (IX) -1 to (IX) -4, which are formulas (IX), and formulas (X) -1 to (X) -6, in which the main skeleton of the azo compound is general formula (X).

Compound examples are shown below (-E in the structural formula of the compound example represents a hydrogen atom or a carboester group —CO—O—R 1, provided that all E groups are not hydrogen atoms at the same time).
<Examples of compounds in which the main skeleton of the azo compound is the general formula (III)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (IV)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (V)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (VI)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (VII)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (VIII)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (IX)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (X)>

  The compound of the formula (I) can be synthesized, for example, as described in the specification of Japanese Patent Application No. 2007-172269 of Patent Document 12, for example, in the presence of a base as a catalyst in an aprotic organic solvent. It can be synthesized by reacting the azo compound of the general formula (II) with the pyrocarbonic acid diester of the following formula (10) at an appropriate molar ratio at a temperature of 150 ° C., preferably 10 to 100 ° C. for 30 minutes to 20 hours. .

（Ｂはアゾ化合物の主骨格、Ｃｐはカップラー成分残基、Ｒ_１は水素原子または置換もしくは無置換のアルキル基を表わす。）
それぞれの場合において、モル比は導入されるＥ（−CO・O−R₁）の数に左右される。好ましくはピロ炭酸ジエステルを少し過剰に用いるのが適している。

(B represents the main skeleton of the azo compound, Cp represents a coupler component residue, and R ₁ represents a hydrogen atom or a substituted or unsubstituted alkyl group.)
In each case, the molar ratio depends on the number of E (—CO · O—R ₁ ) introduced. Preferably, the pyrocarbonic acid diester is used in a slight excess.

  The pyrocarbonic acid diester can react with the azo compound, for example, an N atom such as a carbamoyl group, an O atom such as a hydroxy group, and thus, for example, the structural formula (E = As in (CO-O-R1 group), an azo compound having a carboester group can be obtained. As will be understood from the above, the pyrocarbonic acid diester can react with the coupler component residue Cp (many of which have a hydroxy group at the ortho-position or para-position of the azo group coupling). If B has such a reactive site, it can react. However, these examples are examples with a high degree of carboesterification given for explanation and are not intended to limit the present invention.

  Suitable aprotic organic solvents include, for example, ether solvents such as tetrahydrofuran or dioxane, or glycol ether solvents such as ethylene glycol methyl ether and ethylene glycol ethyl ether, or acetonitrile, N, N-dimethylformamide, N, N- Examples include dimethylacetamide, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, toluene, xylene, nitrobenzene, pyridine, picoline or quinoline. Preferred solvents are pyridine, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide.

  Suitable bases as catalysts are, for example, alkali metals: sodium, potassium, etc., and their hydroxides and carbonates, or alkali metal amides, sodium amides, potassium amides, and alkali metal hydrides, such as Examples include lithium hydride. As the organic aliphatic, aromatic or heterocyclic N-bases, diazabicyclooctene, diazabicycloundecene, 4-dimethylaminopyridine, dimethylpyridine, pyridine, triethylamine and the like can be used. Preferred are organic N-bases such as 4-dimethylaminopyridine, dimethylpyridine and pyridine.

The pyrocarbonic acid diester represented by the above formula (10) can be produced by a generally known method. It is also commercially available. R ₁ is as described above, but a branched alkyl group is preferable from the viewpoint of improving solubility.

In addition, other charge generating materials (pigments) that can coexist in the present invention include azo pigments such as monoazo pigments, disazo pigments, asymmetrical disazo pigments, trisazo pigments, titanyl phthalocyanine, copper phthalocyanine, vanadyl phthalocyanine, hydroxygallium phthalocyanine, no metal Examples thereof include phthalocyanine pigments such as phthalocyanine, perylene pigments, perinone pigments, indigo pigments, pyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, and squalium pigments. Moreover, fullerene, a carbon nanotube, etc. are mention | raise | lifted. Examples of the inorganic nano pigment include zinc oxide, titanium oxide, silicon, silicon oxide, selenium, cadmium sulfide, and cadmium selenide.
These charge generating pigments are preferably as fine particles as possible to enhance the interaction. Specifically, the particle size is 1 micron or less, preferably 0.5 micron or less.
A mechanical pulverization method, a reprecipitation method, a method for atomizing from a gas phase, or the like is used for atomizing the charge generating pigment.

  In the charge generation material used in the present invention, two or more preferable combinations to be selected include a P-type semiconductor or a pigment having an electron-donating structure or substituent and an N-type semiconductor or an electron-withdrawing structure or substitution. A combination with a pigment having a group is preferred. For example, a phthalocyanine pigment exhibiting the properties of a P-type semiconductor and a carboester group represented by the general formula (III), the general formula (VI), or the general formula (VIII) having an electron-withdrawing structure. The azo compound having a decarboesterified azo compound (azo pigment) having a condensed polycyclic pigment or fullerene exhibiting the properties of an N-type semiconductor, and the above general formula (IV) having an electron donating structure Or a composite such as a combination of a decarboxylated azo compound (azo pigment) of an azo compound having a carboester group represented by the general formula (VII) is particularly preferable.

Furthermore, in the photoelectric conversion element of the present invention, the azo compound can coexist at the molecular level by using a solution obtained by dissolving two or more kinds of the azo compounds represented by the general formula (I) in an organic solvent as a coating liquid. In this state, it can also be produced by decarboesterification using chemical means, thermal means or photolytic means.
In this case, depending on the conditions for decarboesterification and the type of azo compound, charge generation pigment particles having a plurality of pigment configurations such as a core-shell structure can be controlled by selectively controlling the reaction rate of a specific type of azo compound. It is also possible to form

The azo compound represented by the general formula (I) of the present invention is decarboesterified using a chemical means, a thermal means and / or a photolytic means, thereby showing the general formula (a). A method for converting to an azo compound will be described.
The chemical means (chemical method) is a method of producing an azo pigment by a catalyst such as an acid or a base, but a preferred catalyst is an acid, and acetic acid, trifluoroacetic acid, propionic acid, acrylic acid, benzoic acid, hydrochloric acid. , Sulfuric acid, boric acid, p-toluenesulfonic acid. And salicylic acid.

  The photolytic means (method) can be used as long as the azo compound represented by the general formula (I) has absorption light. Specifically, a high pressure or low pressure mercury lamp, a tungsten lamp, an LED lamp, a laser light source, or the like can be used.

  The thermal means (thermal method) is a method for producing an azo pigment by heating to 50 ° C. to 300 ° C. in the absence of a solvent or in the presence of a solvent, but preferably 70 ° C. to 250 ° C. under atmospheric pressure. The reaction time is preferably more than 15 minutes and less than 20 hours, more preferably 20 minutes or more, still more preferably 30 minutes or more and 20 hours or less. A plurality of methods among the thermal means (thermal method), the chemical means (chemical method), and the photolytic means (method) can be preferably used in combination.

Among these, the thermal means generally used as a solvent removal method for the coating film is to simultaneously perform the solvent removal of the coating film and the decarboesterification of the azo compound represented by the general formula (I). It can use preferably at the point which can be performed.
As a thermal means, it is carried out by heating from the coating surface side or the conductive support side using a gas such as air, nitrogen, steam, various heat media, infrared rays or electromagnetic waves.
The heating temperature depends on other conditions such as heating time, presence / absence of electromagnetic wave irradiation, presence / absence of decomposition catalyst, but is preferably 80 ° C. or higher and 200 ° C. or lower. If it is lower than 80 ° C., solvent removal may be insufficient depending on the solvent used. In some cases, the solvent remaining in the charge generation layer has a side effect on electrical characteristics such as charge trapping. In addition, when the temperature is higher than 200 ° C., the organic compound as a constituent material may be deteriorated, which also causes side effects on electrical characteristics such as an increase in charge trapping.

  In the present invention, the azo compound represented by the general formula (I) is dissolved in an organic solvent. Examples of the organic solvent used here include ether solvents such as tetrahydrofuran and dioxane, ethylene glycol methyl ether, Glycol ether solvents such as ethylene glycol ethyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, ethyl cellosolve, ethyl acetate, butyl acetate, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, monochlorobenzene, dichlorobenzene Toluene, xylene, anisole, n-hexane, cyclohexane, cyclohexanone, nitrobenzene, pyridine, picoline, quinoline, and the like, and mixed solvents thereof.

  It is also preferable to use a method in which the solution is adsorbed with silica gel, alumina, florisil, activated carbon, activated clay, diatomaceous earth, or perlite. Specific methods of the adsorption treatment include column chromatography, room temperature, or a method of adding an adsorbent during heating and filtering. Further, the treatment can be performed more efficiently by combining with recrystallization.

  The binder resin used for the charge generation layer includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, polyacrylamide. , Polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like. The amount of the binder resin is preferably 0 to 500 parts by mass and more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generation material.

  Solvents used to form the charge generation layer include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, etc. Although generally used organic solvents are mentioned, among these, ketone solvents, ester solvents, and ether solvents are particularly preferable. These may be used alone or in combination of two or more.

The charge generating pigment of the present invention may be dispersed as necessary for crystal type adjustment.
As a dispersion method, any known ball mill, attritor, sand mill, ultrasonic wave, or the like can be used in a suitable solvent together with a binder resin. The binder resin may be added before or after the charge generating material is dispersed.
The coating solution for forming the charge generation layer is mainly composed of a charge generation material, a binder resin and a solvent. Among them, any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil is contained. It may be included.
As a method for coating the charge generation layer using the coating solution, known methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used.

  The thickness of the charge generation layer is preferably about 0.01 to 5 μm, more preferably 0.1 to 2 μm. After coating, it is heated and dried in an oven or the like. The drying temperature of the charge generation layer in the present invention is preferably from 50 ° C. to 160 ° C., more preferably from 80 ° C. to 140 ° C.

<Charge transport layer>
Next, the charge transport layer will be described.
The charge transport layer is formed by applying and drying a coating liquid in which a charge transport material and a binder resin are dissolved or dispersed in a solvent. Moreover, you may add additives, such as a plasticizer, a leveling agent, antioxidant, a lubricant, etc. individually or in 2 types or more to the coating liquid of a charge transport layer as needed.

Examples of the charge transport material include a hole transport material and an electron transport material.
Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.

Examples of the electron transport material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
These charge transport materials may be used alone or in combination of two or more. The content of the charge transport material is usually 20 to 300 parts by weight and preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin.

  Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

  As the solvent, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone or the like is used. Among them, the use of a non-halogen solvent is desirable for the purpose of reducing the environmental load. Specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, aromatic hydrocarbons such as toluene and xylene, and derivatives thereof are preferably used. Two or more of these may be used in combination.

The film thickness of the charge transport layer is preferably 10 to 50 μm, more preferably 15 to 35 μm, from the viewpoint of resolution and responsiveness.
As a coating method, known methods such as a dip coating method, a spray coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method can be used, but the charge transport layer has a certain thickness. Since it is necessary to apply thickly, it is preferable to apply the dip coating method with a highly viscous liquid.
The charge transport layer after coating is heated and dried by a thermal means used in the charge generation layer. Although drying temperature changes also with the solvent contained in a coating liquid, it is preferable that it is 80-200 degreeC, and 110-170 degreeC is more preferable. The drying time is preferably 10 minutes or more, more preferably 20 minutes or more.

<Single layer>
Next, the case where the photosensitive layer has a single layer structure will be described.
This is a photoreceptor in which the above-described charge generation material and charge transport material are dispersed or dissolved in a binder resin to realize a charge generation function and a charge transport function in one layer.
In the photosensitive layer, a charge generating substance, a charge transporting substance and a binder resin are dissolved or dispersed in a solvent such as tetrahydrofuran, dioxane, dichloroethane, methyl ethyl ketone, cyclohexane, cyclohexanone, toluene, xylene, etc. It can be formed by coating using a conventionally known method such as ring coating.

The charge transport material preferably contains both the hole transport material and the electron transport material described above. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
Regarding the charge generating substance, charge transporting substance, binder resin, organic solvent and various additives used in the single photosensitive layer, any material contained in the above-described charge generating layer and charge transporting layer should be used. Is possible.
As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. The amount of the charge generating material with respect to 100 parts by mass of the binder resin is preferably 5 to 40 parts by mass, and more preferably 10 to 30 parts by mass. The amount of the charge transport material is preferably 0 to 190 parts by mass, and more preferably 50 to 150 parts by mass. Further, the film thickness of the photosensitive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.

<Underlayer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer.
In general, the undercoat layer is mainly composed of a resin. However, in consideration of applying a photosensitive layer using a solvent thereon, such a resin is a resin having high solvent resistance to a general organic solvent. Preferably there is. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resins, phenol resins, alkyd-melamine resins, and isocyanates. And curable resins that form a three-dimensional network structure, such as epoxy resins.
Further, a fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, or indium oxide may be added to the undercoat layer in order to prevent moire and reduce residual potential.
Moreover, it can form using a solvent and a coating method similarly to the above-mentioned charge generation layer and charge transport layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer.

<Protective layer>
In the present invention, a protective layer can be provided on the outermost surface of the photoreceptor in order to improve wear resistance.
As the protective layer, a polymer charge transport material type obtained by polymerizing a charge transport component and a binder component, a filler dispersion type containing a filler, a curable type obtained by curing a constituent material having a reactive functional group, and the like are known. However, in the present invention, any conventionally known protective layer can be used.

<Image forming apparatus>
Next, the electrophotographic method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 5 is a schematic view for explaining the electrophotographic process and the image forming apparatus of the present invention, and the following examples also belong to the category of the present invention.
As shown in FIG. 5, the photoconductor (1) has a drum shape, but may be a sheet or an endless belt. For charging roller (12), pre-transfer charger (15), transfer charger (18), separation charger (19), pre-cleaning charger (21), in addition to corotron, scorotron, solid state charger (solid state charger) A roller-shaped charging member or a brush-shaped charging member is used, and all known means can be used.
As the charging member, a non-contact charging method such as corona charging or a contact charging method using a charging member using a roller or a brush is generally used, and any of them can be used effectively in the present invention. In particular, the charging roller can significantly reduce the amount of ozone generated compared to corotron, scorotron, etc., and is effective in stability and prevention of image quality deterioration when the photoreceptor is used repeatedly.
However, due to the contact between the photoconductor and the charging roller, the charging roller is contaminated by repeated use, which affects the photoconductor and contributes to the occurrence of abnormal images and reduced wear resistance. It was.
In particular, when a photoconductor having high wear resistance is used, it is difficult to perform reface due to surface wear, and therefore it is necessary to reduce contamination of the charging roller.

Therefore, as shown in FIG. 6, the charging roller (12) is provided with a gap forming member (12a) and is disposed close to the photoreceptor (1) via the gap, so that contaminants adhere to the charging roller. It is difficult or easy to remove, and the influence thereof can be reduced.
In this case, the gap between the photosensitive member and the charging roller is preferably small, for example, 100 μm or less is preferable, and 50 μm or less is more preferable.
However, by making the charging roller non-contact, discharge may become non-uniform and charging of the photoreceptor may become unstable. Such a problem is caused by maintaining the charging stability by superimposing the alternating current component on the direct current component, thereby making it possible to simultaneously reduce the influence of ozone, the charging roller contamination and the charging effect. .

On the other hand, the light source such as the image exposure unit (13) and the charge removal lamp (11) shown in FIG. 5 includes a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), All luminescent materials such as electroluminescence (EL) can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are mainly used.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
The light source or the like provides the photosensitive member (1) with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step using light irradiation. However, the exposure of the photoreceptor (1) in the charge eliminating step is greatly affected by fatigue on the photoreceptor 1, and may cause a decrease in charge and an increase in residual potential. Therefore, there is a case where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which may be effective from the viewpoint of enhancing the durability of the photoreceptor.
When the electrophotographic photosensitive member (1) is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (detection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

As the transfer means, the above-described charger can be generally used. However, as shown in FIG. 5, a combination of the transfer charger (18) and the separation charger (19) is effective.
Further, the toner image is directly transferred from the photosensitive member to the paper using such a transfer unit. In the present invention, the toner image on the photosensitive member is once transferred to the intermediate transfer member, and then from the intermediate transfer member to the paper. An intermediate transfer method for transferring the toner to the photoconductor is more preferable for enhancing the durability or improving the image quality of the photoreceptor.
Among the contaminants that adhere to the surface of the photoconductor, discharge substances generated by charging and external additives contained in the toner are easy to pick up the effects of humidity and cause abnormal images. Paper powder is one of the causative substances, and when they adhere to the photoreceptor, abnormal images are more likely to occur, as well as a tendency to reduce wear resistance and cause uneven wear. Is seen. Therefore, it is more preferable from the viewpoint of high image quality that the photoconductor and the paper are not in direct contact for the above reason.

  The intermediate transfer method is particularly effective for image forming apparatuses capable of full-color printing, and controls the prevention of color misregistration by forming a plurality of toner images on the intermediate transfer member and then transferring them to the paper at once. It is easy and effective for high image quality. However, the intermediate transfer method requires four scans to obtain one full-color image, so that the durability of the photoconductor has been a big problem. The photoconductor of the present invention is particularly effective and useful since it is easy to use in combination with an intermediate transfer type image forming apparatus because image blurring hardly occurs even without a drum heater. The intermediate transfer member includes various materials or shapes such as a drum shape and a belt shape. In the present invention, any conventionally known intermediate transfer member can be used. It is effective and useful for achieving high quality or high image quality.

The toner developed on the photosensitive member (1) by the developing unit (14) shown in FIG. 5 is transferred to the transfer paper (17), but not all of the toner is transferred to the photosensitive member (1). The toner remaining in the toner is also generated.
Such toner is removed from the photoreceptor (1) by the fur brush (22) or the cleaning blade (23). This cleaning process may be performed only with a cleaning brush or may be performed in combination with a blade, and known cleaning brushes such as a fur brush and a mag fur brush are used. As described above, the cleaning is a process of removing toner remaining on the photosensitive member (1) after the transfer. However, the photosensitive member (1) is repeatedly rubbed by the cleaning blade (23) or the fur brush (22). As a result, wear of the photoconductor (1) is promoted, or an abnormal image may be generated due to scratches.

In addition, if the surface of the photoconductor is contaminated due to poor cleaning, it not only causes an abnormal image, but also significantly reduces the life of the photoconductor.
In particular, in the case of a photoconductor with a protective layer on the outermost layer to improve wear resistance, it is difficult to remove contaminants adhering to the surface of the photoconductor, which promotes the generation of filming and abnormal images. Will do. Therefore, improving the cleaning property of the photoconductor is very effective for improving the durability and image quality of the photoconductor.
As means for improving the cleaning property of the photosensitive member, a method of reducing the coefficient of friction on the surface of the photosensitive member is known. Methods for reducing the coefficient of friction on the surface of the photoreceptor are classified into a method in which various lubricants are contained in the photoreceptor surface and a method in which the lubricant is supplied to the photoreceptor surface from the outside. The former is advantageous for small-diameter photoreceptors because of the high degree of freedom in layout around the engine, but the coefficient of friction increases remarkably with repeated use, and there remains a problem in its sustainability. On the other hand, the latter needs to be provided with a component for supplying a lubricating substance, but is effective for enhancing the durability of the photoreceptor because of high stability of the friction coefficient. Among them, the method of adhering to the photoreceptor during development by incorporating a lubricant into the developer is not restricted by the layout around the engine, and the effect of reducing the friction coefficient on the photoreceptor surface is high. Therefore, it is a very effective means for improving the durability and image quality of the photoreceptor.
These lubricants include lubricating fluids such as silicone oil and fluorine oil, various fluorine-containing resins such as PTFE, PFA and PVDF, silicone resins, polyolefin resins, silicone grease, fluorine grease, paraffin wax, fatty acid esters , Fatty acid metal salts such as zinc stearate, lubricating liquids such as graphite and molybdenum disulfide, solids, powders, and the like, but particularly when mixed with a developer, it must be in the form of a powder, especially stearic acid Zinc has little adverse effect and can be used very effectively. When the zinc stearate powder is contained in the toner, it is necessary to consider the balance and the influence on the toner, and the content is preferably 0.01 to 0.5% by mass with respect to the toner. 3 mass% is more preferable.

  The photoconductor according to the present invention can be applied to a small-diameter photoconductor because high photosensitivity and high stability are realized. Accordingly, as an image forming apparatus or method using the above photoreceptor more effectively, each developing unit corresponding to a plurality of colors of toner is provided with a plurality of corresponding photoreceptors, thereby performing parallel processing. It is very effectively used in a so-called tandem type image forming apparatus. The tandem image forming apparatus includes at least four color toners of yellow (C), magenta (M), cyan (C), and black (K) required for full-color printing and a developing unit that holds them. Further, by providing at least four photoconductors corresponding to them, full-color printing can be performed at a very high speed as compared with a conventional image forming apparatus capable of full-color printing.

FIG. 7 is a schematic diagram for explaining the tandem-type full-color electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention.
In FIG. 7, photoconductors (1C) (cyan), (1M) (magenta), (1Y) (yellow), and (1K) (black) are drum-like photoconductors (1), and these photoconductors. (1C), (1M), (1Y), (1K) rotate in the direction of the arrow in the figure, and charging members (12C), (12M), (12Y), (12K), Developing members (14C), (14M), (14Y), (14K), and cleaning members (15C), (15M), (15Y), (15K) are arranged.
The charging members (12C), (12M), (12Y), and (12K) constitute a charging device for uniformly charging the surface of the photoreceptor (1). From the back side of the photoreceptor (1) between the charging members (12C), (12M), (12Y), (12K) and the developing members (14C), (14M), (14Y), (14K). Then, laser beams (13C), (13M), (13Y), and (13K) from an exposure member (not shown) are irradiated, and electrostatic latent images are formed on the photoreceptors (1C), (1M), (1Y), and (1K). Is to be formed.
Then, the four image forming elements (10C), (10M), (10Y), and (10K) centering on such photoconductors (1C), (1M), (1Y), and (1K) serve as transfer materials. It is juxtaposed along the transfer and transport belt (25) which is a transport means. The transfer conveyance belt (25) includes developing members (14C), (14M), (14Y), and (14K) of the image forming units (elements) (10C), (10M), (10Y), and (10K), Between the cleaning members (15C), (15M), (15Y), and (15K), the photosensitive members (1C), (1M), (1Y), and (1K) are in contact with the transfer conveyance belt (25). Transfer brushes (26C), (26M), (26Y), and (26K) for applying a transfer bias are disposed on a surface (back surface) that is in contact with the back side of the photoconductor (1). Each of the image forming elements (10C), (10M), (10Y), and (10K) is different in the color of the toner inside the developing device, and the others are the same in configuration.

In the color electrophotographic apparatus having the configuration shown in FIG. 7, the image forming operation is performed as follows. First, in each of the image forming elements (10C), (10M), (10Y), (10K), the photoconductors (1C), (1M), (1Y), (1K) are in the direction indicated by the arrows (photoconductor (1)). Exposure unit (not shown) which is charged by charging members (12C), (12M), (12Y) and (12K) which rotate in the rotation direction and then arranged outside the photoreceptor (1). Thus, an electrostatic latent image corresponding to each color image to be created is formed by the laser beams (13C), (13M), (13Y), and (13K).
Next, the latent image is developed by developing members (14C), (14M), (14Y), and (14K) to form a toner image. Development members (14C), (14M), (14Y), and (14K) are development members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. The toner images of the respective colors produced on the two photoconductors (1C), (1M), (1Y), and (1K) are superimposed on the transfer paper. The transfer paper (17) is fed out from the tray by the paper feed roller (24), and is temporarily stopped by the pair of registration rollers (16). The transfer paper (17) is transferred to the transfer conveyance belt (25) in synchronization with the image formation on the photoconductor. Sent.
The transfer paper (17) held on the transfer / conveying belt (25) is conveyed, and each color at the contact position (transfer portion) with each photoconductor (1C), (1M), (1Y), (1K). The toner image is transferred.
The toner image on the photoconductor includes the transfer bias applied to the transfer brushes (26C), (26M), (26Y), and (26K) and the photoconductors (1C), (1M), (1Y), and (1K). The image is transferred onto the transfer paper (17) by an electric field formed from the potential difference. Then, the recording paper (17) on which the four color toner images are passed through the four transfer portions is conveyed to the fixing device (27), where the toner is fixed, and is discharged to a paper discharge portion (not shown). The Further, the residual toner remaining on each of the photoconductors (1C), (1M), (1Y), and (1K) without being transferred by the transfer unit is removed from the cleaning devices (15C), (15M), (15Y), ( 15K).

In the example of FIG. 7, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements (10C), (10M), and (10Y) other than black.
Further, although the charging member is in contact with the photosensitive member in FIG. 7, by using a charging mechanism as shown in FIG. 6, an appropriate gap (about 10 to 200 μm) is provided between them. In addition, the wear amount of the both can be reduced, and toner filming on the charging member can be reduced and the toner can be used satisfactorily.

The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.
The process cartridge includes the photoelectric conversion element of the present invention, and further includes at least one of a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit, and is detachable from the image forming apparatus. Device (parts).
An example of the process cartridge is shown in FIG. 8, but the neutralizing means is not described here.
The above-described tandem image forming apparatus can transfer a plurality of toner images at a time, so that high-speed full-color printing is realized.
However, since at least four photoconductors are required, an increase in the size of the apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the wear amount of each photoconductor, thereby reproducing the color. There are many problems such as a decrease in performance and occurrence of abnormal images.
On the other hand, the photosensitive member according to the present invention can be applied to a small-diameter photosensitive member by realizing high photosensitivity and high stability, and the influence of increase in residual potential, sensitivity deterioration, etc. is reduced. Even if the amount of the photoconductor used is different, the difference in residual potential and sensitivity over time is small, and a full color image having excellent color reproducibility can be obtained even when used repeatedly for a long time.

<Synthesis Example of Azo Compound Having Carboester Group in the Present Invention>
Next, the azo compound having a carboester group represented by the general formula (I) of the present invention is synthesized, for example, by the method described in Japanese Patent Application No. 2007-172269, and an example thereof is shown below.
(1) Synthesis of Exemplary Compound (III-2) Precursor of azo compound having a carboester group represented by the structural formula (III-2) [all E groups in structural formula (III-2) are H ( 1.61 grams, pyrocarboxylic acid di-tert-butyl ester 4.3 grams (10-fold mole) was dispersed in 50 ml of dehydrated pyridine and 200 ml of dehydrated N, N-dimethylformamide, and the mixture was stirred at room temperature for 15 minutes. After stirring, the mixture was further heated to about 50 ° C. and reacted for 2 hours. Gradually reddish and a homogeneous solution was obtained. After returning to room temperature, the solvent was removed, and about 100 ml of ethyl acetate was added to obtain 2.24 grams (yield: 93%) of a red powder.
The results of elemental analysis of the obtained powder are shown in Table 1 below.
In addition, the calculated value (%) of each element in the following Table 1 assumes that all the carboester groups (E groups) whose products are represented by the structural formula (III-2) are C ₅ H ₉ O _2. The chemical formula of the azo compound is calculated as C ₆₈ H ₆₃ N ₆ O ₁₃ Cl.

また、上記生成物の赤外線吸収スペクトル（ＫＢｒ錠剤法）による分析の結果、置換基に由来する吸収、すなわち、２９８０ｃｍ^−１に飽和炭化水素に基づく吸収、１７６０ｃｍ^−１にカルボネートのＣ＝Ｏ伸縮振動に基づく吸収が認められた。

As a result of analysis by infrared absorption spectrum (KBr tablet method) of the product, absorption derived from a substituent, i.e., absorption based on saturated hydrocarbons 2980cm ^-1, C = O stretching vibration of carbonate to 1760 cm ^-1 Absorption based on was observed.

(2) Synthesis of Exemplified Compound (IX-2) Precursor of azo compound having a carboester group represented by the structural formula (IX-2) [all E groups in the structural formula (IX-2) are H ( 0.93 gram, pyrocarboxylic acid di-tert-butyl ester 3.20 gram (15-fold mol) was dispersed in 200 ml of dehydrated pyridine, stirred at room temperature for 15 minutes, and further heated to about 50 ° C. Warmed and allowed to react for 2 hours. Gradually reddish and a homogeneous solution was obtained. After returning to room temperature, the solvent was removed, and about 100 ml of methanol was added to obtain 1.17 grams (yield: 90%) of a red-orange powder.
The results of elemental analysis of the obtained powder are shown in Table 2 below.
In addition, the calculated value (%) of each element in the following Table 2 assumes that all carboester groups (E groups) whose products are represented by the structural formula (IX-2) are C ₅ H ₉ O _2. The chemical formula of the azo compound is calculated as C ₇₆ H ₇₀ N ₈ O ₁₀ Cl ₂ .

また、上記生成物の赤外線吸収スペクトル（ＫＢｒ錠剤法）による分析の結果、置換基に由来する吸収、すなわち、２９８０ｃｍ^−１に飽和炭化水素に基づく吸収、１７６０ｃｍ^−１にカルボネートのＣ＝Ｏ伸縮振動に基づく吸収が認められた。
以上のように、各種のアゾ化合物の前駆体に対して過剰量のピロカルボン酸ジ−ｔｅｒｔ−ブチルエステルを反応させることにより本発明の一般式（Ｉ）で表わされる数多くのカルボエステル基を有するアゾ化合物を合成することができる。

As a result of analysis by infrared absorption spectrum (KBr tablet method) of the product, absorption derived from a substituent, i.e., absorption based on saturated hydrocarbons 2980cm ^-1, C = O stretching vibration of carbonate to 1760 cm ^-1 Absorption based on was observed.
As described above, an azo compound having a large number of carboester groups represented by the general formula (I) of the present invention by reacting an excess amount of pyrocarboxylic acid di-tert-butyl ester with various azo compound precursors. Compounds can be synthesized.

Hereinafter, although an example is given and the present invention is explained, the present invention is not restricted by these examples.
All parts are parts by weight.

After coating on an aluminum cylinder having a length of 346 mm and a diameter of 40 mm using an intermediate layer coating liquid having the following composition, drying was performed at 130 ° C. for 20 minutes to form an intermediate layer of about 3.5 μm. Subsequently, a coating solution for a charge generation layer having the following composition was ball milled for 2 hours together with zirconia balls having a diameter of 5 mm. A generation layer was formed.
Furthermore, after coating using a coating solution for a charge transport layer having the following composition, drying was performed at 130 ° C. for 20 minutes to form a charge transport layer of about 20 μm, and an electrophotographic photoreceptor of Example 1 was produced. In all cases, the dip coating method was used.
(Intermediate layer coating solution)
Titanium oxide CR-EL (manufactured by Ishihara Sangyo Co., Ltd.): 50 parts alkyd resin Beckolite M6401-50 (solid content 50% by weight, manufactured by Dainippon Ink & Chemicals, Inc.): 15 parts melamine resin L-145-60 (solid content 60) % By weight, manufactured by Dainippon Ink & Chemicals, Inc.): 8 parts 2-butanone: 120 parts (coating liquid for charge generation layer)
Azo compound of specific example (III-2) (wherein carboester group part E: C ₆ H ₁₁ O ₂ ): 1.5 parts Y-type titanyl phthalocyanine (manufactured by Toyo Ink Co., Ltd .; Riophoton-TOPA): 1.5 Part polyvinyl butyral (“XYHL” manufactured by UCC): 2 parts methyl ethyl ketone: 110 parts chloroform: 50 parts (coating liquid for charge transport layer)
Polycarbonate Z polycarbonate (manufactured by Teijin Chemicals Ltd .; Panlite TS-2050): 10 parts Charge transporting compound represented by the following structural formula: 7 parts

テトラヒドロフラン：８０部
シリコーンオイル（ＫＦ５０−１００ｃｓ、信越化学工業社製）：０．００２部

Tetrahydrofuran: 80 parts Silicone oil (KF50-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.002 parts

A photoconductor of Example 2 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Azo compound of specific example (III-3) (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Y-type titanyl phthalocyanine: 1.5 parts polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 100 parts Chloroform: 50 parts trifluoroacetic acid (acidic catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 3 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Example (III-4) azo compound (E: C ₆ H ₁₁ O ₂ ) purified using silica gel as adsorbent and chloroform as solvent: 1.5 parts
Type II chlorogallium phthalocyanine (reference; Patent No. 3123185): 1.5 parts polyvinyl butyral ("XYHL" manufactured by UCC): 2 parts methyl ethyl ketone: 100 parts chloroform: 50 parts trifluoroacetic acid (acid catalyst for decarboesterification) ): 10 parts Heat drying condition: 160 ° C./1 hour

A photoconductor of Example 4 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific example (IV-1) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts
Type II chlorogallium phthalocyanine: 1.5 parts polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 150 parts trifluoroacetic acid (acidic catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 5 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific example (V-1) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts V-type hydroxygallium phthalocyanine: 1.5 parts polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 100 Parts chloroform: 50 parts trifluoroacetic acid (acid catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 6 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific example (VI-1) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts V-type hydroxygallium phthalocyanine: 1.5 parts polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 150 Part trifluoroacetic acid (acid catalyst for decarboesterification): 15 parts heat drying condition: 190 ° C./1 hour

A photoconductor of Example 7 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Azo compound of specific example (VII-2) (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Bisazo pigment having the following structural formula: 1.5 parts

ポリビニルブチラール（「ＸＹＨＬ」ＵＣＣ製）：２部
メチルエチルケトン：１５０部
トリフロオロ酢酸（脱カルボエステル化用の酸性触媒）：１０部
加熱乾燥条件：１６０℃／１時間

Polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 150 parts trifluoroacetic acid (acidic catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 8 was produced in the same manner as in Example 1 except that the heating and drying conditions of the charge generation layer coating liquid and charge generation layer of Example 1 were changed as follows.
(Coating solution for charge generation layer)
Specific example (VIII-5) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Quinacridone pigment having the following structural formula: 1.5 parts

ポリビニルブチラール（「ＸＹＨＬ」ＵＣＣ製）：２部
メチルエチルケトン：７５部
クロロホルム：７５部
トリフロオロ酢酸（脱カルボエステル化用の酸性触媒）：１０部
加熱乾燥条件：１６０℃／１時間

Polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts Methyl ethyl ketone: 75 parts Chloroform: 75 parts Trifluoroacetic acid (acid catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 9 was prepared in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific Example (III-2) Azo Compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Specific Example (IX-2) Azo Compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 130 parts N, N-dimethylformamide: 20 parts trifluoroacetic acid (acid catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C./1 hour

A photoconductor of Example 10 was produced in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific example (III-2) azo compound (E: C ₆ H ₁₁ O ₂ ): 1 part Specific example (X-1) azo compound (E: C ₆ H ₁₁ O ₂ ): 1 part τ-type metal-free Phthalocyanine: 1 part polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 130 parts N, N-dimethylformamide: 20 parts trifluoroacetic acid (acidic catalyst for decarboesterification): 10 parts Heat drying conditions: 160 ° C. / 1 hour

A photoconductor of Example 11 was prepared in the same manner as in Example 1 except that the coating solution for charge generation layer of Example 1 and the heating and drying conditions of the charge generation layer were changed as follows.
(Coating solution for charge generation layer)
Specific Example (III-2) Azo Compound (E: C ₆ H ₁₁ O ₂ ): 1 part Specific Example (IV-1) Azo Compound (E: C ₆ H ₁₁ O ₂ ): 1 part Specific Example (V -1) azo compound (E: C ₆ H ₁₁ O ₂ ): 1 part polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 130 parts N, N-dimethylformamide: 20 parts trifluoroacetic acid (decarboxyester) Acid catalyst for conversion): 10 parts Heat drying condition: 160 ° C./1 hour

The intermediate layer of Example 1 has a two-layer structure of a charge blocking layer and a moire preventing layer, the charge generation layer coating solution and the heat drying conditions of the charge generation layer are changed as follows, and the surface protective layer is as follows: A photoconductor of Example 12 was produced in the same manner as Example 1 except that the photoconductor was provided.
(Intermediate layer prototype conditions)
After dip-coating the coating solution for charge blocking layer having the following composition, drying was performed at 130 ° C./20 minutes to form a charge blocking layer having a thickness of about 0.5 μm. Subsequently, a moiré preventing layer coating solution having the following composition was applied by dip coating, followed by drying at 130 ° C. for 30 minutes to provide a 3.5 μm moiré preventing layer.
(Coating solution for charge blocking layer)
N-methoxymethylated nylon (Lead City, FR101): 5 parts Methanol: 70 parts n-Butanol: 30 parts (Coating liquid for moire prevention layer)
Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., CR-EL): 126 parts Alkyd resin (manufactured by Dainippon Ink & Chemicals, Beckolite M6401-50-S): 33.6 parts melamine resin (manufactured by Dainippon Ink & Chemicals, Super Becker Min L-121-60): 18.7 parts 2-butanone: 100 parts (coating liquid for charge generation layer)
Specific example (III-2) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Y-type titanyl phthalocyanine: 1.5 parts polyvinyl butyral (“XYHL” manufactured by UCC): 2 parts methyl ethyl ketone: 100 parts Chloroform: 50 parts trifluoroacetic acid (acid catalyst for decarboesterification): 10 parts Heat drying conditions: 120 ° C./30 minutes (surface protective layer trial production conditions)
On the charge transport layer, a surface protective layer having the following composition was spray-coated, followed by heat drying at 130 ° C./20 minutes to provide a 4 μm surface protective layer.
(Coating liquid for surface protective layer)
Alumina (average primary particle size: 0.3 μm, Sumiko Random AA-03, manufactured by Sumitomo Chemical): 2 parts Charge transporting compound represented by the following structural formula: 4 parts

不飽和ポリカルボン酸ポリマー溶液（酸価１８０ｍｇＫＯＨ／ｇ、固形分５０％、ＢＹＫ−Ｐ１０４ＢＹＫケミー製）：０．０２部
ポリカーボネート（Ｚポリカ、帝人化成製）：６部
テトラヒドロフラン：２２０部
シクロヘキサノン：８０部

Unsaturated polycarboxylic acid polymer solution (acid value 180 mgKOH / g, solid content 50%, manufactured by BYK-P104BYK Chemie): 0.02 part polycarbonate (Z Polyca, manufactured by Teijin Chemicals): 6 parts Tetrahydrofuran: 220 parts Cyclohexanone: 80 parts

A photoconductor of Example 13 was prepared in the same manner as in Example 12 except that the coating solution for charge generation layer, the heating and drying conditions of the charge generation layer, and the surface protective layer of Example 12 were changed as follows.
(Charge generation layer prototype conditions)
After coating the charge generation layer having the following composition, the UV light of 800 W / cm ² is irradiated for 10 minutes using an Ushio UV lamp system to remove the azo compound represented by the general formula (a). Carboester was performed. During UV irradiation, a barrel thermo 200 (manufactured by Matsumura Oil, heat medium oil) was circulated inside the conductive support so that the temperature was 120 ° C.
(Coating solution for charge generation layer)
Specific example (III-2) azo compound (E: C ₆ H ₁₁ O ₂ ): 1.5 parts Y-type titanyl phthalocyanine: 1.5 parts polyvinyl butyral (“XYHL” manufactured by UCC): 2 parts methyl ethyl ketone: 100 parts Chloroform: 50 parts trifluoroacetic acid (acid catalyst for decarboesterification): 20 parts (surface protective layer trial production conditions)
Furthermore, after spray-coating a surface protective layer having the following composition on the charge transport layer, using the above-mentioned Ushio UV lamp system, UV curing is performed for 120 seconds, followed by drying at 100 ° C./20 minutes. As a result, a surface protective layer of 4 μm was provided.
(Coating liquid for surface protective layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARADTMPTA): 10 parts Hexafunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAADDPCA-120): 5 parts Polymerizable compound having a charge transporting structure of the following structure: 10 parts

重合開始剤（チバ・スペシャリティ・ケミカルズ製、イルガキュア１８４）：１部
テトラヒドロフラン：５０部

Polymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 50 parts

(Comparative Example 1)
A photoconductor of Comparative Example 1 was prepared in the same manner as in Example 1 except that the charge generation layer coating solution of Example 1 was changed as follows. This is an example of a single charge generating pigment that is not an azo compound represented by the general formula (I) of the present invention.
(Coating solution for charge generation layer)
Y-type titanyl phthalocyanine: 3 parts polyvinyl butyral ("XYHL" manufactured by UCC): 2 parts methyl ethyl ketone: 160 parts

(Comparative Example 2)
A photoconductor of Comparative Example 2 was prepared in the same manner as in Example 1 except that the heating condition of the charge generation layer of Example 1 was changed to 80 ° C./5 minutes and that methyl ethyl ketone was 100 parts. This is an example in which the heating conditions are not sufficient and the azo compound of the general formula (I) contained in the charge generation layer is not converted to the azo compound represented by the general formula (a).

(Comparative Example 3)
A photoconductor of Comparative Example 3 was produced in the same manner as in Example 1 except that the charge generation layer coating solution of Example 1 was changed as follows. This is an example of the charge generating pigment of the azo compound alone represented by the general formula (I) of the present invention.
(Coating solution for charge generation layer)
Specific example (III-2) azo compound (E: C ₆ H ₁₁ O ₂ ): 3 parts polyvinyl butyral (“XYHL” manufactured by UCC): 2 parts methyl ethyl ketone: 100 parts chloroform: 50 parts

(Comparative Example 4)
A photoconductor of Comparative Example 4 was produced in the same manner as in Example 1 except that the charge generation layer coating solution of Example 1 was changed as follows. This is an example in which the coating liquid does not contain the azo compound represented by the general formula (I) of the present invention.
(Coating solution for charge generation layer)
Bisazo pigment having the following structural formula (without carboester group): 1.5 parts

Ｙ型チタニルフタロシアニン：１．５部
ポリビニルブチラール（「ＸＹＨＬ」ＵＣＣ製）：２部
メチルエチルケトン：１６０部

Y-type titanyl phthalocyanine: 1.5 parts polyvinyl butyral ("XYHL" manufactured by UCC): 2 parts methyl ethyl ketone: 160 parts

<Evaluation of actual machine>
As shown in FIG. 8, the photoreceptors of Examples 1 to 13 and Comparative Examples 1 to 4 previously prepared were mounted on a process cartridge from which the lubricant application member had been removed, and an image MPC5000 (Ricoh's digital full-color multifunction peripheral). ).
As a process condition at the time of the test, the applied voltage to the charging member was set so that the charged potential of the unexposed portion was −800V. The development bias was set to -600V. As a sheet passing condition, 40,000 sheets were printed using a chart with a writing rate of 6% (characters equivalent to 6% as an image area are written on the entire A4 surface). The test environment is normal temperature and humidity as temperature: 23 ° C., relative humidity: 55%, high temperature and high humidity environment as temperature: 30 ° C., relative humidity: 80%, and low temperature and low humidity environment as temperature: 10 ° C., relative humidity: 15%. The same printing test was conducted under the three environmental conditions.
In the image evaluation, after printing 40,000 images, the voltage set during the test was applied to the charging member, an all-white image was output, and the stain on the background portion was evaluated. The image evaluation of the background portion was carried out in 4 stages. Very good ones were indicated by ◎, good ones were indicated by ○, slightly inferior ones were indicated by Δ, and very bad ones were indicated by ×.
Also, before and after printing 40,000 images, ISO / JIS-SCID images N1 (portraits) were output to evaluate the color color reproducibility. The color reproducibility evaluation was carried out in four stages. Very good ones were indicated by ◎, good ones were indicated by ○, slightly inferior ones by Δ, and very bad ones by x. The results are shown in Table 3.
In addition, the same image evaluation as described above was performed using the applied voltage of the charging member in which the charged potential of the unexposed portion was −500 V before the printing test. The results are shown in Table 4.
Furthermore, the difference in film thickness (amount of wear) before and after the printing test was also evaluated for the photoreceptors of Examples 1 to 14. The film thickness was measured using an eddy current film thickness measurement system (Fischer), except for 5 cm at both ends in the longitudinal direction of the photoreceptor, and measured at intervals of 1 cm, and the average value was taken as the film thickness. Table 5 shows the average value of the amount of wear under the three environments.

＜塗工液保存評価＞
実施例１〜１３および比較例１〜４の電荷発生層用塗工液を温度６０℃、相対湿度５０％の環境下で１ヶ月保存を行なった。この保存液を長さ３４６ｍｍ、φ４０ｍｍのアルミニウムシリンダーに浸漬塗布後、１６０℃／３０分間の加熱乾燥を行ない、約０．３μｍの電荷発生層を形成し、実施例１４〜２６、比較例５〜８のシリンダー状サンプルを得た。これらサンプルについて目視により塗膜欠陥を観察した。結果を表６に示す。

<Coating fluid storage evaluation>
The charge generation layer coating solutions of Examples 1 to 13 and Comparative Examples 1 to 4 were stored for 1 month in an environment of a temperature of 60 ° C. and a relative humidity of 50%. This preservation solution was dip-coated on an aluminum cylinder having a length of 346 mm and a diameter of 40 mm, followed by heat drying at 160 ° C./30 minutes to form a charge generation layer of about 0.3 μm. Examples 14 to 26 and Comparative Examples 5 to 5 Eight cylindrical samples were obtained. These samples were visually observed for coating film defects. The results are shown in Table 6.

  As can be seen from the above examples, the photoelectric conversion element obtained by the production method of the present invention uses an azo compound having a carboester group that can be dissolved in a solvent, and decarboxylates it to convert it into an azo compound. In order to form a plurality of pigments containing at least this azo compound, mixing at a molecular level is performed, a uniform and fine composite structure is formed, and impurities and the like are removed, so that the function as a photoelectric conversion element is sufficiently exerted. In addition, it is extremely useful as a charge generation pigment used in a high-sensitivity electrophotographic photosensitive member that can cope with high image quality and high speed such as copying machines and laser printers. In addition, long-term stable storage of the coating solution was achieved, and the productivity improvement of the charge generation layer was realized.

DESCRIPTION OF SYMBOLS 1 Photoconductor 1C, 1M, 1Y, 1K Photoconductor 2 Conductive support 3 Charge generation layer 4 Charge transport layer 5 Protective layer 6 Undercoat layer 7 Single layer type photosensitive layer 10C, 10M, 10Y, 10K Image forming element 11 Static elimination Lamp 12 Charging roller 12a Gap forming member 12C, 12M, 12Y, 12K Charging member 13 Image exposure unit 13C, 13M, 13Y, 13K Laser light 14 Developing unit 14C, 14M, 14Y, 14K Developing member 15 Pre-transfer charger 15C, 15M, 15Y, 15K Cleaning member 16 Registration roller 17 Transfer paper 18 Transfer charger 19 Separation charger 20 Separation claw 21 Charger before cleaning 22 Fur brush 23 Cleaning blade 24 Feed roller 25 Transfer conveyance belt 26C, 26M, 26Y, 26K Transfer brush 27 Fixing device

JP 47-37543 A JP 52-55643 A JP-A-52-8832 JP 58-222152 A JP 58-222153 A Japanese Patent No. 3326706 JP 2001-290296 A Japanese Patent Laid-Open No. 9-127711 JP 2002-23399 A JP 2007-334099 A Japanese Patent Laid-Open No. 3-9962 JP 2009-7523 A JP-T-2001-513119

Claims (18)

After applying a coating solution composed of a plurality of charge generation materials containing at least an azo compound having a carboester group represented by the following general formula (I), decarboesterification is carried out, whereby the following general formula (a) is shown. A method for producing a photoelectric conversion element, wherein the photoelectric conversion element is converted into an azo compound.

[Wherein, in formula (I), A is a residue of an azo compound, and this residue A is bonded to n E groups via one or more heteroatoms, and The heteroatom is selected from the group consisting of N and O and forms part of the residue A, and the E group is independently H (hydrogen atom) or a carboester group represented by the following formula: —C ( ═O) —O—R ¹ [wherein R ¹ represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group having 4 to 10 carbon atoms. ]. However, not all E groups are hydrogen atoms at the same time. n is an integer from 1 to 9. ]

[In the formula (a), A is as defined in the general formula (I), H represents a hydrogen atom, and n is an integer of 1 to 9. ]   The other charge generation material (other than the carboester group-containing azo compound) of the plurality of charge generation materials is selected from the group of phthalocyanine pigments, azo pigments, condensed polycyclic pigments, fullerenes, or carbon nanotubes. The manufacturing method of the photoelectric conversion element of Claim 1 characterized by these.   The azo compound having a carboester group represented by the general formula (I) is dissolved in an organic solvent, and the solution is adsorbed with silica gel, alumina, florisil, activated carbon, activated clay, diatomaceous earth, or perlite, and then subjected to chemical treatment. The azo compound represented by the general formula (a) is converted by decarboesterification using a general means, a thermal means, or a photolytic means. The manufacturing method of the photoelectric conversion element of description.   The method for producing a photoelectric conversion element according to any one of claims 1 to 3, wherein a thermal means is used when decarboesterifying the azo compound having a carboester group.   The method for producing a photoelectric conversion element according to any one of claims 1 to 4, wherein a thermal means and a chemical means are used in combination when the azo compound having a carboester group is decarboesterified. The general formula (I) and A in the general formula (a) are residues of an azo compound represented by the following general formula (II), according to any one of claims 1 to 5. A method for producing a photoelectric conversion element.

[In the formula (II), B represents the main skeleton of the azo compound, Cp represents a coupler component residue, and m represents an integer of 2 or 3. ] Cp in the said general formula (II) is a coupler component residue shown by at least any one of the following general formula (1) thru | or (9), The manufacture of the photoelectric conversion element of Claim 6 characterized by the above-mentioned. Method.

[However, in the formulas (1) to (4), X, Y ¹ , Z, p and q each represent the following.
X: —OH, —N (R ¹ ) (R ² ) or —NHSO ₂ —R ³ (wherein R ¹ and R ² represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R ³ represents A substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group).
Y ¹ : a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or unsubstituted sulfamoyl group, or —CON (R ⁴ ) (Y ² ) { R ⁴ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or —N═C (R ⁵ ) (R ⁶ ) [wherein R ⁵ is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, and R ⁶ is a hydrogen atom, an alkyl group, a phenyl group or a substituted product thereof. Or R ⁵ and R ⁶ may form a ring together with carbon atoms bonded to them. ] Is shown. },
Z: a hydrocarbon ring or a substituted product thereof, or a heterocyclic ring or a substituted product thereof,
p: an integer of 1 or 2, q: an integer of 1 or 2. ]

[In the formula (5), R ⁷ represents a substituted or unsubstituted hydrocarbon group, and X is the same as defined above. ]

[In the formula (6), A represents a ring of a divalent aromatic hydrocarbon group or a nitrogen atom necessary for forming an N-containing heterocycle together with the two N atoms described in the formula (6). Represents a divalent group containing a hetero atom contained therein (these rings may be substituted or unsubstituted). X is the same as described above. ]

[In the formula (7), R ⁸ represents an alkyl group, a carbamoyl group, a carboxy group or an ester thereof, Ar ¹ represents a hydrocarbon ring group or a substituent thereof, and X is the same as defined above. ]

[In the formulas (8) and (9), R ⁹ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and Ar ² represents a hydrocarbon ring group or a substituted product thereof. However, at the same time, R ⁹ is not a hydrogen atom and Ar ² is not a cycloalkyl group or a cycloalkenyl group. ] The method for producing a photoelectric conversion element according to claim 6 or 7, wherein B in the general formula (II) is represented by the following general formula (III).

[In the formula (III), R ¹¹ and R ¹² independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. ] B in the said general formula (II) is shown by the following general formula (IV), The manufacturing method of the photoelectric conversion element of Claim 6 or 7 characterized by the above-mentioned.

[In the formula (IV), R ¹³ , R ¹⁴ , and R ¹⁵ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. Represent. ] B in said general formula (II) is shown by the following general formula (V), The manufacturing method of the photoelectric conversion element of Claim 6 or 7 characterized by the above-mentioned.

[However, in the formula (V), R ¹⁶ , R ¹⁷ and R ¹⁸ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] The method for producing a photoelectric conversion element according to claim 6 or 7, wherein B in the general formula (II) is represented by the following general formula (VI).

[In the formula (VI), R ¹⁹ and R ²⁰ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. ] The method for producing a photoelectric conversion element according to claim 6 or 7, wherein B in the general formula (II) is represented by the following general formula (VII).

[In the formula (VII), R ²¹ , R ²² and R ²³ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] The method for producing a photoelectric conversion element according to claim 6 or 7, wherein B in the general formula (II) is represented by the following general formula (VIII).

[In the formula (VIII), R ²⁴ , R ²⁵ and R ²⁶ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group or an ester thereof. Represent. ] B in said general formula (II) is shown by the following general formula (IX), The manufacturing method of the photoelectric conversion element of Claim 6 or 7 characterized by the above-mentioned.

[In the formula (IX), R ²⁷ , R ²⁸ , and R ²⁹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. Represent. ] B in said general formula (II) is shown by the following general formula (X), The manufacturing method of the photoelectric conversion element of Claim 6 or 7 characterized by the above-mentioned.

[In the formula (X), R ³⁰ and R ³¹ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. ]   16. The photoelectric conversion element according to claim 1, a charger for charging at least the photoelectric conversion element, a latent image forming unit for forming an electrostatic latent image on the surface of the photoelectric conversion element charged by the charger, A developing unit that attaches toner to the electrostatic latent image formed by the image forming unit, a transfer unit that transfers the toner image formed by the developing unit to a transfer target, and a toner that remains on the surface of the photoelectric conversion element after transfer An image forming apparatus having a cleaning device for removing from the surface of the photoelectric conversion element.   16. The photoelectric conversion element according to claim 1, a charger for charging at least the photoelectric conversion element, a latent image forming unit for forming an electrostatic latent image on the surface of the photoelectric conversion element charged by the charger, A developing unit that attaches toner to the electrostatic latent image formed by the image forming unit, a transfer unit that transfers the toner image formed by the developing unit to a transfer target, and a toner that remains on the surface of the photoelectric conversion element after transfer An image forming method comprising: a cleaning device that removes the surface of the photoelectric conversion element.   16. The photoelectric conversion element according to claim 1, a charger for charging at least the photoelectric conversion element, a latent image forming unit for forming an electrostatic latent image on the surface of the photoelectric conversion element charged by the charger, A developing unit that attaches toner to the electrostatic latent image formed by the image forming unit, a transfer unit that transfers the toner image formed by the developing unit to a transfer target, and a toner that remains on the surface of the photoelectric conversion element after transfer A process cartridge for an image forming apparatus having one means selected from the group consisting of a cleaning device for removing from the surface of a photoelectric conversion element, wherein the process cartridge is detachable from an image forming apparatus main body.

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