JP4256365B2 - Electrophotographic photosensitive member and image forming apparatus using the same - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member used in an image forming apparatus such as an electrostatic copying machine, a laser beam printer, and a facsimile.

Conventionally, an electrophotographic photosensitive member having sensitivity in a wavelength region of a light source used in the image forming apparatus is used in an image forming apparatus such as an electrostatic copying machine, a facsimile machine, or a laser beam printer. In such an electrophotographic photosensitive member, a photosensitive layer formed of a charge transfer agent, a charge generator, and a binder resin is provided on a conductive substrate.
The photosensitive layer is formed, for example, by applying a coating solution for forming a photosensitive layer in which a charge generating agent, a charge transporting agent, and a binder resin are dispersed and dissolved in an organic solvent on a conductive substrate. (Formation of a single-layer type photosensitive layer).

  In recent years, high sensitivity and high responsiveness have been desired for electrophotographic photosensitive members. As a charge transport material for improving the sensitivity and responsiveness of an electrophotographic photosensitive member, Patent Document 1 discloses the following general A triphenylamine derivative represented by the formula (91) has been proposed.

（式（９１）中、Ｒ^９１、Ｒ^９２、Ｒ^９３、Ｒ^９４、Ｒ^９５はそれぞれ同一であっても異なっていてもよく、水素原子、炭素数１〜６のアルキル基、アルコキシ基、ハロゲン原子、置換基を有していてもよいアリール基を示すか、またはＲ^９２、Ｒ^９３およびＲ^９４、Ｒ^９５はそれぞれが互いに結合して環を形成していてもよく、ｎは０または１を示す。）
特開平７−１７３１１２号公報

(In Formula (91), R ⁹¹ , R ⁹² , R ⁹³ , R ⁹⁴ , and R ⁹⁵ may be the same or different, and each represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group, or a halogen atom. An atom, an aryl group which may have a substituent, or R ⁹² , R ⁹³ and R ⁹⁴ , R ⁹⁵ may be bonded to each other to form a ring, and n is 0 or 1 Is shown.)
JP 7-173112 A

However, since the triphenylamine derivative (91) described in Patent Document 1 has low solubility in an organic solvent and compatibility with a binder resin, there is a problem that it is difficult to prepare a coating solution for forming a photosensitive layer. .
On the other hand, for example, it is possible to prepare a coating solution for forming a photosensitive layer in which the solid content is completely dissolved by reducing the solid content concentration of the triphenylamine derivative (91) or the binder resin, Since the compatibility between the triphenylamine derivative (91) and the binder resin is low, there is a problem that the triphenylamine derivative (91) is crystallized when the photosensitive layer forming coating solution is applied and dried.

Therefore, the electrophotographic photoreceptor provided with the above-described photosensitive layer has a defect that an image defect occurs during the image forming process or a crack occurs in the photosensitive layer, and the sensitivity characteristic of the electrophotographic photoreceptor is remarkably deteriorated. There is also a bug to do.
In addition, when the electrophotographic photosensitive member having the photosensitive layer described above is mounted on an image forming apparatus that does not have a charge eliminating unit, the image formed on the first rotation of the photosensitive drum is the rotation 2 of the photosensitive drum. There is a risk of the so-called ghost phenomenon remaining on the circumference.

  An object of the present invention is to provide an electrophotographic photosensitive member comprising a charge transport agent having excellent solubility in an organic solvent and excellent compatibility with a binder resin, and including a photosensitive layer having high charge mobility. .

  In order to achieve the above object, the electrophotographic photoreceptor of the present invention comprises a photosensitive layer containing a charge generator, a charge transport agent and a binder resin on a conductive substrate, and the charge transport agent has the following general formula ( It is a triphenylamine compound represented by 1).

（一般式（１）中、Ｒ ^１ は炭素数２〜６のアルキル基を示す。Ｒ ^２ は炭素数１〜６のアルキル基を示す。

(In General Formula (1), R ¹ represents an alkyl group having 2 to 6 carbon atoms. R ² represents an alkyl group having 1 to 6 carbon atoms .

R ⁶ and R ⁷ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

R ⁸ and R ⁹ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

a to d are the same or different and are integers of 0 to 5, respectively . )
In the electrophotographic photoreceptor of the present invention, the photosensitive layer is a single photosensitive layer containing the charge generating agent, the charge transporting agent and the binder resin, and directly on the conductive substrate. Alternatively, it is preferably formed through an intermediate layer.

In the electrophotographic photosensitive member of the present invention, the photosensitive layer is a laminate including the charge generating layer containing the charge generating agent and the binder resin and the charge transporting layer containing the charge transporting agent and the binder resin. And it is preferably formed on the conductive substrate directly or through an intermediate layer.
In the image forming apparatus of the present invention, the image carrying means, the charging means for charging the surface of the image carrying means, and the exposure for forming the electrostatic latent image by exposing the surface of the image carrying means. And a transfer unit for transferring the toner image from the image holding unit to a transfer target, and the image holding unit. In an image forming apparatus that does not have a charge eliminating means for removing the charge on the means surface, it is preferable that the image carrying means is the above-described electrophotographic photosensitive member.

In the image forming apparatus of the present invention, it is preferable that the charging unit is a charging roller.

  According to the electrophotographic photoreceptor of the present invention, the triphenylamine compound (1) having excellent solubility in an organic solvent and compatibility with a binder resin is used as a charge transport agent, and the above triphenyl is used. Since the amine compound (1) has high charge mobility, it is possible to suppress the occurrence of image defects and cracks while achieving high sensitivity and high responsiveness during image formation processing. .

Hereinafter, embodiments of the electrophotographic photoreceptor according to the present invention will be described in detail.
(Configuration of electrophotographic photoreceptor)
In the present embodiment, the electrophotographic photoreceptor includes a photosensitive layer containing a charge generating agent, a charge transporting agent, and a binder resin on a conductive substrate.
(Conductive substrate)
As the conductive substrate, various materials having conductivity can be used. The conductive substrate is not particularly limited as long as the substrate itself has conductivity or the surface of the substrate has conductivity. Specific examples thereof include simple metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass; Examples thereof include glass coated with plastic materials, aluminum iodide, tin oxide, indium oxide, etc .; resin substrates in which conductive fine particles such as carbon black are dispersed. The shape of the conductive substrate may be any of a sheet shape and a drum shape according to the structure of the image forming apparatus used.

  Further, the conductive substrate is not limited to the above-described examples, and for example, the surface of the conductive substrate may be subjected to an oxide film treatment or a resin film treatment. The oxide film treatment for the conductive substrate includes, for example, a process of forming an anodic oxide film (anodic oxide film) on the surface of the conductive substrate when aluminum or titanium is used as the conductive substrate. The anodized film is formed by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc., and the treatment is performed in sulfuric acid, particularly in the acidic baths exemplified above. Is preferred. The method of anodizing treatment, the method of degreasing treatment performed prior to the anodizing treatment, and the like are not particularly limited, and may be performed according to a conventional method. Examples of the resin coating treatment on the conductive substrate include a treatment in which a nylon resin, a phenol resin, a melamine resin, an alkyd resin, a polyvinyl acetal resin, or the like is dissolved in an appropriate solvent and applied to the surface of the conductive substrate. It is done. As the resin material used for the resin coating treatment, it is particularly preferable to use nylon resin or resol type phenol resin among the resins exemplified above.

(Charge generator)
Examples of the charge generator include metal-free phthalocyanine represented by the following formula (CGM1), titanyl phthalocyanine represented by the following formula (CGM2), hydroxygallium phthalocyanine represented by the following formula (CGM3), and the following formula (CGM4). ) Phthalocyanine pigments such as chlorogallium phthalocyanine, such as disazo pigments, such as disazo condensation pigments, monoazo pigments, perylene pigments, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squalane Line pigment, trisazo pigment, indigo pigment, azurenium pigment, cyanine pigment, pyrylium salt, ansanthrone pigment, triphenylmethane pigment, selenium pigment, toluidine pigment, pyrazoline pigment, quinacridone pigment, and other conventionally known pigments Charge generating agent 's and the like.

電荷発生剤は、電子写真感光体が所望の吸収波長域で感度を有するように、上記例示のものの中から種々選択すればよい。上記例示の電荷発生剤は単独で用いてもよく、２種以上を混合して用いてもよい。

The charge generating agent may be variously selected from those exemplified above so that the electrophotographic photosensitive member has sensitivity in a desired absorption wavelength region. The charge generators exemplified above may be used alone or in combination of two or more.

  Currently, semiconductor lasers (LDs) and light emitting diodes (LEDs) are used as exposure light sources in digital optical image forming apparatuses such as laser beam printers, and their wavelengths range from 680 to 830 nm (so-called wavelength range). Since the “near-infrared region”) is the mainstream, a charge generating agent for an electrophotographic photoreceptor used in a digital image forming apparatus is required to have excellent sensitivity in the near-infrared region. Therefore, as described above, phthalocyanines such as metal-free phthalocyanine (CGM1), titanyl phthalocyanine (CGM2), hydroxygallium phthalocyanine (CGM3), and chlorogallium phthalocyanine (CGM4) are preferably used.

  The crystal form of the phthalocyanine pigment is not particularly limited, and various types can be adopted. Among these, from the viewpoint of further improving the sensitivity of the photoreceptor, X-type or τ-type is used for metal-free phthalocyanine (CGM1), and α-type is used for titanyl phthalocyanine (CGM2) (its X-ray diffraction spectrum). , Having a main diffraction peak when the Bragg angle (2θ ± 0.2 °) is 7.6 ° and 28.6 °, or Y type (Bragg angle (2θ ± 0.2 °) is 27.2 °) It is preferable to use a compound having a main diffraction peak at the time of V), a type V for hydroxygallium phthalocyanine (CGM3), and a type II for chlorogallium phthalocyanine (CGM4).

For the analog optical image forming apparatus such as an electrostatic copying machine using a white light source such as a halogen lamp, among the charge generators exemplified above, perylene pigments and bisazo pigments having sensitivity in the visible region are suitable. Used for.
In order to improve characteristics such as dispersibility of the charge generating agent in the binder resin, an azo pigment such as disazo yellow, dianisidine orange, pyrazolone orange, or pyrazolone red may be blended.

(Charge transport agent)
As the charge transport agent, a triphenylamine compound represented by the above general formula (1) as a hole transport agent is used. Moreover, as long as the effect of this invention is not impaired, you may use together hole transport agents other than the said triphenylamine type compound. Moreover, an electron transport agent may be used in combination as the charge transport agent, and this electron transport agent is a triphenylamine compound represented by the above general formula (1) as long as the formation of a charge transfer complex is prevented. May be present in the same photosensitive layer.

(Hole transport agent)
In the general formula (1), R ¹ represents an alkyl group having 2 to 6 carbon atoms. R ² represents an alkyl group having 1 to 6 carbon atoms .

The alkyl group having 2 to 6 carbon atoms may be linear or branched, for example, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, Neopentyl, isopentyl, n-hexyl and the like can be mentioned. The number of carbon atoms of the alkyl group is preferably 2 to 4, more preferably 2 or 3.
The alkyl group having 1 to 6 carbon atoms may be linear or branched, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, Examples include pentyl, neopentyl, isopentyl, and n-hexyl. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 or 2.

In the general formula (1), R ⁶ and R ⁷ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

As the alkyl group having a carbon number of 1 to 6, the same as described above can be mentioned, and the number of carbon atoms is preferably 1 to 4, more preferably 1 or 2.

In the general formula (1), R ⁸ and R ⁹ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

As the alkyl group having a carbon number of 1 to 6, the same as described above can be mentioned, and the number of carbon atoms is preferably 1 to 4, more preferably 1 or 2.

In the above following general formula (1), to d is the number of ^R 6 to R ⁹ to be substituted with the same benzene ring, respectively, the same or different and each represents an integer of 0 to 5, preferably, 0 2, more preferably 0 or 1. When ad is 2 or more, the two or more substituents substituted on the same benzene ring may be different from each other.

The triphenylamine compound represented by the general formula (1) may be used alone or in combination of two or more.
Specific examples of R ¹ , R ² , R ^{6 to} R ⁹ are shown in Table 1.

表１中、Ｍｅはメチルを、Ｅｔはエチルを、ｉ−Ｐｒはイソプロピルを、それぞれ示す。また、「４−」は、それぞれ、ベンゼン環上での置換位置を示す。なお、ベンゼン環上での置換位置は、下記式に示すとおりである。また、「−」は、水素を示す（すなわち、そのベンゼン環上の水素が置換基により置換されていないことを示す）。

In Table 1, Me represents methyl, Et represents ethyl, and i-Pr represents isopropyl. In addition , “ 4-” indicates a substitution position on the benzene ring. The substitution position on the benzene ring is as shown in the following formula. “-” Represents hydrogen (that is, hydrogen on the benzene ring is not substituted with a substituent).

（式中、Ｒ^１ 、Ｒ ^２ 、Ｒ ^６ 〜Ｒ ^９ およびａ〜ｄは、いずれも上記と同じである。）
上記トリフェニルアミン系化合物（１）は、例えば、後述する合成法１および合成法２によって、合成される。

(In the formula, R ¹ , R ² , R ^{6 to} R ⁹ and a to d are all the same as above.)
The triphenylamine compound (1) is synthesized by, for example, synthesis method 1 and synthesis method 2 described later.

(Synthesis method 1)
Step 1: An excess amount of N, N-dimethylformamide (DMF) and phosphoryl chloride is added to the triphenylamine derivative (11), and this is heated and subjected to the so-called Vilsmeier-Haack reaction. 4,4′-diformyltriphenylamine derivative (12) is obtained.

（式中、Ｒ^１ 、Ｒ ^２ は、いずれも上記と同じである。）
上記反応においては、溶媒として、ＤＭＦ以外に、Ｎ−メチルホルムアニリド（ＭＦＡ）などの非プロトン性溶媒を用いることもできる。また、塩化ホスホリルに代えて、ホスゲン、塩化チオニルなどを用いることもできる。

(Wherein R ¹ and R ² are the same as above)
In the above reaction, in addition to DMF, an aprotic solvent such as N-methylformanilide (MFA) can also be used as a solvent. Further, phosgene, thionyl chloride, or the like can be used instead of phosphoryl chloride.

Step 2: The 1,3-diarylethylene (14) is obtained by reacting the benzophenone derivative (13) with (i) methylmagnesium chloride (MeMgCl) and then (ii) adding an acid to dehydrate it. . Examples of the acid include PTSA (p-toluenesulfonic acid). Next, polyoxymethylene [(CH ₂ O) _n ] and hydrochloric acid are added to the 1,1-diarylethylene (14) thus obtained and reacted, and the resulting compound (14 ′) and The trialkyl phosphite is reacted to give 3,3′-diarylallylphosphonic acid dialkyl ester (15).

（式中、Ｒ^６、Ｒ^７、ａおよびｂは、いずれも上記と同じである。Ｒは、アルキル基を示す。）
工程３：上記工程１で得られた４，４’−ジホルミルトリフェニルアミン誘導体（１２）と、上記工程２で得られた３，３’−ジアリールアリルホスホン酸ジアルキルエステル（１５）とを塩基の存在下で反応させることにより、トリフェニルアミン系化合物（２１）を得ることができる。

(In the formula, R ⁶ , R ⁷ , a and b are all the same as described above. R represents an alkyl group.)
Step 3: Base the 4,4′-diformyltriphenylamine derivative (12) obtained in Step 1 above and the 3,3′-diarylallylphosphonic acid dialkyl ester (15) obtained in Step 2 above The triphenylamine compound (21) can be obtained by reacting in the presence of.

（式中、Ｒ^１ 、Ｒ ^２ 、Ｒ ^６ 、Ｒ ^７ 、ａ、ｂは、いずれも上記と同じである。Ｒは、アルキル基を示す。）
上記一般式（２１）で表されるトリフェニルアミン系化合物は、一般式（１）で表されるトリフェニルアミン系化合物のうちＲ^６とＲ^８が同一で、かつ、Ｒ^７とＲ^９が同一である化合物である。

(In the formula, R ¹ , R ² , R ⁶ , R ⁷ , a and b are all the same as above. R represents an alkyl group.)
In the triphenylamine compound represented by the general formula (21), R ⁶ and R ⁸ are the same among the triphenylamine compounds represented by the general formula (1), and R ⁷ and R ⁹ are It is the compound which is the same.

In order to obtain the triphenylamine compound represented by the general formula (1), for example, one formyl group of the 4,4′-diformyltriphenylamine derivative represented by the above formula (12) is protected. And after reacting with an equimolar amount of the 3,3′-diarylallylphosphonic acid dialkyl ester represented by the above formula (15), after removing the protecting group of the one formyl group, (of the formula (15), ^{R 6} is R ^8, and, ^{R 7} is as an R ⁹⁾ equimolar amounts of 3,3'-diaryl allyl phosphonic acid dialkyl esters may be reacted with. Further, a 3,3′-diarylallylphosphonic acid dialkyl ester represented by the above formula (15) and a compound of the formula (15) in which R ⁶ is R ⁸ and R ⁷ is R ⁹ Even if the mixture is reacted with a 4,4′-diformyltriphenylamine derivative represented by the formula (12), the triphenylamine compound represented by the formula (1) is isolated from the reaction product. Good.

(Synthesis method 2)
Step 1: Using 4-chlorobenzyl chloride derivative (22), diphenylacetaldehyde is added to and reacted with the obtained arylphosphonic acid dialkyl ester (23) to obtain compound (24).

（式中、Ｒ^６、Ｒ^７ 、ａ、ｂは、いずれも上記と同じである。Ｒは、アルキル基を示す。）
工程２：次いで、得られた化合物（２４）とアニリン誘導体（２５）とを反応させて、トリフェニルアミン系化合物（３１）を得ることができる。

(In the formula, R ⁶ , R ⁷ , a and b are all the same as described above. R represents an alkyl group.)
Step 2: Next, the triphenylamine compound (31) can be obtained by reacting the obtained compound (24) with the aniline derivative (25).

（式中、Ｒ^１、Ｒ ^２ 、Ｒ ^６ 、Ｒ ^７ 、ａ、ｂは、いずれも上記と同じである。）
上記一般式（３１）で表されるトリフェニルアミン系化合物は、一般式（１）で表されるトリフェニルアミン系化合物のうち、Ｒ^６とＲ^８が同一、Ｒ^７とＲ^９が同一の化合物である。

(In the formula, R ¹ , R ² , R ⁶ , R ⁷ , a and b are all the same as above.)
Triphenylamine compound represented by the general formula (31), of the triphenylamine compound represented by the general formula (1), identical to R ⁶ and R ^8, R ⁷ and R ⁹ same It is a compound of this.

In order to obtain the triphenylamine-based compound represented by the general formula (1), for example, an aniline derivative represented by the formula (25) having one protecting group introduced on the nitrogen atom of the amine is used. , After reacting with an equimolar amount of the compound (24), after removing the protecting group on the nitrogen atom, an equimolar amount of the compound represented by the formula (24) (provided that R ⁶ is R is ^8, one ^{R 7} is ^{R 9.)} the may be reacted. A mixture of the compound represented by formula (24) and the compound represented by formula (24) with a compound in which R ⁶ is R ⁸ and R ⁷ is R ⁹ is represented by formula (25). The triphenylamine compound represented by the formula (1) may be isolated from the reaction product by reacting with the aniline derivative represented by formula (1).

  The triphenylamine compound (1) synthesized as described above is excellent in solubility in an organic solvent (dispersion medium) described later and compatibility in a binder resin. Therefore, even when the photosensitive layer is formed using the above triphenylamine compound, problems such as crystallization of the triphenylamine compound or generation of cracks can be suppressed. The triphenylamine compound (1) has a high charge mobility. Therefore, the photosensitive layer containing such a triphenylamine compound (1) can improve the sensitivity and responsiveness of the electrophotographic photoreceptor.

(Electron transfer agent)
The electron transfer agent is not particularly limited, and can be appropriately selected from conventionally known electron transfer agents. When the electron transport agent is blended in the same photosensitive layer together with the hole transport agent, the electron transport agent does not form a charge transfer complex with the hole transport agent. Is required.

  Examples of the electron transfer agent include diphenoquinone derivatives represented by the following general formulas (ETM1) and (ETM2), stilbenequinone derivatives represented by the following general formula (ETM3), the following general formulas (ETM4), (ETM5), Naphthoquinone derivatives represented by (ETM6) and (ETM7), dinaphthoquinone derivatives represented by the following general formulas (ETM8) and (ETM9), the following general formulas (ETM10), (ETM11), (ETM12) and (ETM13) And a naphthalene tetracarboxylic acid diimide derivative represented by the following general formula (ETM14). These may be used alone or in combination of two or more.

（一般式（ＥＴＭ１）〜（ＥＴＭ１４）中、Ｒ^ｅ１〜Ｒ^ｅ１１、Ｒ^ｅ１３〜Ｒ^ｅ２６、Ｒ^ｅ３２〜Ｒ^ｅ３７、Ｒ^ｅ４０およびＲ^ｅ４１は、同一または異なって、水素、炭素数１〜８のアルキル基または炭素数１２以下のアリール基を示す。Ｒ^ｅ１２は、水素、炭素数１〜８のアルキル基、炭素数１２以下のアリール基、炭素数１〜９のアルキルカルボニル基、炭素数１〜９のアルコキシカルボニル基、炭素数１３以下のアリールカルボニル基または炭素数１３以下のアリールオキシカルボニル基を示す。Ｒ^ｅ２７、Ｒ^ｅ２９およびＲ^ｅ３１は、同一または異なって、炭素数１〜８のアルキル基、炭素数１２以下のアリール基、塩素原子またはニトロ基を示す。Ｒ^ｅ２８、Ｒ^ｅ３０、Ｒ^ｅ３８およびＲ^ｅ３９は同一または異なって、炭素数１〜８のアルキル基または炭素数１２以下のアリール基を示す。ａは０〜３の整数を示し、ｂは０〜４の整数を示す。上記アリール基、アリールカルボニル基およびアリールオキシカルボニル基は、そのアリール部分にニトロ基などの置換基をさらに有していてもよい。）
上記一般式（ＥＴＭ１２）で表されるアゾキノン誘導体は、アニリン誘導体（置換基（Ｒ^ｅ３１）aを備えるもの）と亜硝酸ナトリウムに濃塩酸を加えてジアゾニウム化合物を生成させて、このジアゾニウム化合物と９−ヒドロキシ−１０−メチルアントラセンの誘導体（置換基（Ｒ^ｅ３０）bを備えるもの）とをジアゾカップリングさせた後、こうして得られた生成物のヒドロキシ基を酸化することによって得られる。

(In the general formulas (ETM1) to (ETM14), R ^{e1 to} R ^e11 , R ^{e13 to} R ^e26 , R ^{e32 to} R ^e37 , R ^e40 and R ^e41 are the same or different, ^Represents an alkyl group or an aryl group having 12 or less carbon atoms, R ^e12 represents hydrogen, an alkyl group having 1 to 8 carbon atoms, an aryl group having 12 or less carbon atoms, an alkylcarbonyl group having 1 to 9 carbon atoms, or 1 to 1 carbon atoms. 9 alkoxycarbonyl group, ^{.R e27, R e29} and ^{R e31} showing the aryloxycarbonyl group having 13 or less arylcarbonyl group or carbon number of 13 or less carbon atoms, which may be the same or different, an alkyl group having 1 to 8 carbon atoms ^Represents an aryl group having 12 or less carbon atoms, a chlorine atom or a nitro group, wherein R ^e28 , R ^e30 , R ^e38 and R ^e39 are the same or different. And an alkyl group having 1 to 8 carbon atoms or an aryl group having 12 or less carbon atoms, a represents an integer of 0 to 3, and b represents an integer of 0 to 4. The above aryl group, arylcarbonyl group, and The aryloxycarbonyl group may further have a substituent such as a nitro group in the aryl moiety.)
The azoquinone derivative represented by the above general formula (ETM12) is obtained by adding concentrated hydrochloric acid to an aniline derivative (having a substituent (R ^e31 ) a) and sodium nitrite to form a diazonium compound. It is obtained by diazo coupling a derivative of -hydroxy-10- ^{methylanthracene} (with a substituent (R ^e30 ) b) and then oxidizing the hydroxy group of the product thus obtained.

  Although not limited thereto, the electron transport agent exemplified above has at least one nitro group, two or more carboxyl groups, and two or more acyl groups in the molecule. Preferably there is. When the electron transporting agent has the above-exemplified groups, for example, when the electrophotographic photosensitive member of this embodiment is used for image formation by a wet development method and is brought into contact with a paraffinic solvent (wet developer solvent). Even so, it can be suppressed that the electron transport agent is eluted from the photosensitive layer. That is, it is preferable to use the electron transfer agent having the above exemplified group from the viewpoint of the solvent resistance of the photoreceptor.

(Binder resin)
The binder resin is not particularly limited. For example, a polycarbonate having a bisphenol such as bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol Z type, bisphenol A type, bisphenol C type, and bisphenol ZC type in a repeating unit. Resin; bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol Z type, bisphenol A type, bisphenol C type, bisphenol ZC type and the like, benzenedicarboxylic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid , Aromatic dicarboxylic acids such as anthracene dicarboxylic acid and phenanthrene dicarboxylic acid; polyester resins, polystyrene resins, poly (meth) acrylates Le esters, polyvinyl acetal resins, polyamide resins, silicone resins, vinyl acetate resins, vinyl chloride - vinyl acetate copolymer resin.

(Photosensitive layer)
The photosensitive layer containing the charge generating agent, charge transporting agent and binder resin is a single photosensitive layer containing the charge generating agent, charge transporting agent and binder resin (so-called single layer type photosensitive layer), charge generation A form (a so-called laminated photosensitive layer) including a charge generation layer containing an agent and a binder resin and a charge transport layer containing a charge transport agent and a binder resin is employed. A laminated photosensitive layer is suitably used as the photosensitive layer of the electrophotographic photoreceptor.

An electrophotographic photosensitive member in which a single-layer type photosensitive layer is formed on a conductive substrate (hereinafter referred to as “single-layer type electrophotographic photosensitive member”), and an electron in which a laminated photosensitive layer is formed on a conductive substrate. Photoreceptors (hereinafter referred to as “laminated electrophotographic photoreceptors”) can be used in both development methods of dry development and wet development.
Next, a method for producing a single layer type electrophotographic photosensitive member and a method for producing a laminated type electrophotographic photosensitive member will be described.

(Method for producing single-layer electrophotographic photoreceptor)
The single-layer type electrophotographic photosensitive member includes a charge generator, a triphenylamine compound (hole transport agent) represented by the general formula (1), a binder resin, and, if necessary, other hole transport. A coating solution for forming a photosensitive layer (hereinafter referred to as “coating solution for forming a photosensitive layer”) obtained by dispersing or dissolving an agent, an electron transporting agent, and other components in an appropriate dispersion medium is conductive. It is obtained by coating on a conductive substrate and drying.

  As other components, in the coating solution for forming a photosensitive layer, various conventionally known additives other than the above-mentioned components, for example, an antioxidant, radical scavenging, etc., as long as the electrophotographic characteristics are not adversely affected. Agents, singlet quenchers, UV absorbers and other deterioration inhibitors, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, etc. . In order to improve the sensitivity of the monolayer type photosensitive layer, for example, a known sensitizer such as terphenyl, halonaphthoquinones, acenaphthylene and the like may be used in combination with the charge generator. Further, a surfactant, a leveling agent or the like may be used in order to improve the dispersibility of the charge transport agent or charge generator and the smoothness of the photosensitive layer surface.

  The dispersion medium is conventionally used as a coating solution for forming a photosensitive layer by preparing a coating solution for forming a photosensitive layer by dispersing and dissolving the charge generating agent, charge transporting agent, binder resin and the like exemplified above. Various organic solvents are used. Specifically, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; dichloromethane, dichloroethane and chloroform , Halogenated hydrocarbons such as carbon tetrachloride and chlorobenzene; dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether (“methyl cellosolve (R)”), ethylene glycol monoethyl ether (“ethyl cellosolve (R)”) , Glycol ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether; oxetane, tetra Cyclic ethers such as drofuran (THF), 2-methyltetrahydrofuran, tetrahydrapyran, 1,2-dioxane, 1,3-dioxane, dioxolane; ketones such as acetone, methyl ethyl ketone, cyclohexanone; ethyl acetate, methyl acetate, etc. Esters; dimethylformaldehyde, dimethylformamide, dimethyl sulfoxide and the like.

  The dispersion medium is not limited to this, but in order to stably disperse each component such as a charge generator, a charge transport agent, and a binder resin, among various organic solvents, in particular, oxetane, tetrahydrofuran It is preferable to use at least one cyclic ether selected from the group consisting of (THF), 2-methyltetrahydrofuran, tetrahydrapyran, 1,2-dioxane, 1,3-dioxane and dioxolane. More preferably, tetrahydrofuran (THF) is used.

The thickness of the photosensitive layer is preferably set to 5 to 100 μm, particularly 10 to 50 μm.
The charge generating agent may be blended in an amount of 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the binder resin. What is necessary is just to mix | blend a hole transport agent in the ratio of 10-200 weight part with respect to 100 weight part of binder resin, Preferably 20-100 weight part. What is necessary is just to mix | blend an electron transport agent in the ratio of 5-100 weight part with respect to 100 weight part of binder resin, Preferably it is 10-80 weight part. In the case where the electron transport agent and the hole transport agent are used in combination, the total amount of the electron transport agent and the hole transport agent is 20 to 300 parts by weight, preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. It is appropriate to do.

Preparation of the coating solution for forming the photosensitive layer is carried out by using the above-described charge generator, charge transport agent, insoluble azo pigment, binder resin, etc. together with a suitable solvent, such as a roll mill, ball mill, attritor, paint shaker, ultrasonic disperser, etc. What is necessary is just to disperse and mix using a well-known means.
(Method for producing laminated electrophotographic photosensitive member)
In the production of a multilayer electrophotographic photosensitive member, first, a charge generating layer obtained by dispersing or dissolving a charge generating agent, a binder resin, and, if necessary, the above-mentioned other components in an appropriate dispersion medium. A charge generating layer is formed by applying a coating liquid for forming (hereinafter referred to as “charge generating layer forming coating liquid”) onto a conductive substrate and drying. Next, a triphenylamine compound (hole transport agent) represented by the general formula (1), a binder resin, and, if necessary, another hole transport agent, an electron transport agent, and the other components Is dispersed or dissolved in a suitable dispersion medium, and the resulting coating liquid for forming a charge transport layer (hereinafter referred to as “coating liquid for forming a charge transport layer”) is applied onto the charge generation layer and dried. A charge transport layer is formed. In this way, a multilayer electrophotographic photosensitive member obtained by laminating the charge generation layer and the charge transport layer in this order on the conductive substrate is obtained. The order of stacking the charge generation layer and the charge transport layer may be the reverse of the above, but since the film thickness of the charge generation layer is usually thin and its strength is not sufficient, It is preferable to do this.

  The thickness of the charge generation layer is preferably set to be 0.01 to 5 μm, particularly 0.5 to 2 μm. The charge generation agent may be blended in an amount of 20 to 1000 parts by weight, preferably 40 to 500 parts by weight, with respect to 100 parts by weight of the binder resin in the charge generation layer. The hole transport agent may be blended at a ratio of 10 to 200 parts by weight, preferably 20 to 100 parts by weight, with respect to 100 parts by weight of the binder resin.

Although not particularly limited in the present invention, the characteristics of the photoreceptor are not hindered between the conductive substrate and the photosensitive layer in either the single-layer electrophotographic photoreceptor or the multilayer electrophotographic photoreceptor. If necessary, an undercoat layer (barrier layer) as an intermediate layer may be formed as necessary. Further, a protective layer may be formed on the surface of the photoreceptor.
(Effects of electrophotographic photoreceptor)
According to the electrophotographic photosensitive member such as the single-layer type electrophotographic photosensitive member or the laminated type electrophotographic photosensitive member described above, the triphenylamine type having excellent solubility in an organic solvent and compatibility with a binder resin as a charge transporting agent. The compound (1) is used, and the triphenylamine compound (1) has a high charge mobility. Therefore, it is possible to suppress the occurrence of image defects and cracks and achieve high sensitivity and high responsiveness during the image forming process.

In addition, in an image forming apparatus having a photosensitive layer using the above triphenylamine compound as a charge transport agent, the electrical characteristics (sensitivity, responsiveness, etc.) of the photosensitive layer are good. Even an image forming apparatus that does not have a charge eliminating unit can realize an image forming process without an image defect.
(Configuration of image forming apparatus)
FIG. 1 is a schematic configuration diagram of an image forming apparatus.

Next, an image forming apparatus using the above-described electrophotographic photosensitive member as a photosensitive drum will be described with reference to FIG.
As shown in FIG. 1, the image forming apparatus 10 includes a photosensitive drum (image carrying unit) 1, a charging roller (charging unit) 2 for charging the surface of the photosensitive drum 1, and a photosensitive drum 1. An exposure device (exposure means) 3 for exposing the surface to form an electrostatic latent image, a development device (development means) 4 for developing the electrostatic latent image as a toner image, and the toner image on the photosensitive drum And a transfer roller (transfer means) 5 for transferring from 1 to a sheet (transfer object) 7. Further, the image forming apparatus 10 does not have a static elimination lamp (static elimination means) for removing electric charges on the surface of the photosensitive drum 1 which is included in a normal image forming apparatus.

  The charging means of the image forming apparatus is not limited to the charging roller 2 described above. For example, a charger charging charger such as a corotron charger, a scorotron charger, a solid discharge element, a needle electrode device, or a conductive A contact-type charger such as a conductive brush can be used. Among these, the charging roller (contact type) has an advantage that the amount of generated ozone is small, and therefore is preferably used in an image forming apparatus such as a printer.

  The charging means, exposure means, developing means, transfer means, and cleaning means are not particularly limited in the present invention, and various devices can be appropriately employed.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these Examples and a comparative example at all.
(Production Example 1)
(Synthesis of charge generator)
In a flask purged with argon, 25 g of o-phthalonitrile, 28 g of titanium tetrabutoxide, and 300 g of quinoline were added and heated to 150 ° C. with stirring.

Next, the mixture was heated to 215 ° C. while distilling off the vapor generated from the reaction system, and then stirred at 215 ° C. for 2 hours to cause a reaction.
Thereafter, the reaction mixture is cooled to 150 ° C., the reaction mixture is taken out from the flask, filtered through a glass filter, and the resulting solid is washed successively with N, N-dimethylformamide (DMF) and methanol. By drying, 24 g of a blue-violet solid was obtained.

(Pre-treatment of charge generating agent for pigmentation)
Next, 10 g of the obtained solid was added to 100 ml of N, N-dimethylformamide (DMF), and this was stirred and heated to 130 ° C. and stirred for 2 hours. Next, after cooling to 23 ± 1 ° C., the stirring was stopped and the mixture was allowed to stand for 12 hours. And the stationary DMF solution was filtered off with a glass filter, and the obtained solid was washed with methanol, and then this solid was vacuum dried to obtain 9.83 g of crude crystals of titanyl phthalocyanine (CGM2). .

(Pigmentation of charge generator)
The obtained crude crystals of titanyl phthalocyanine (CGM2) (5 g) were added to 100 ml of concentrated sulfuric acid and dissolved. Next, this concentrated sulfuric acid solution was dropped into ice-cooled water, stirred at room temperature for 15 minutes, and then allowed to stand at 23 ± 1 ° C. for 30 minutes for recrystallization. Next, this concentrated sulfuric acid solution was filtered off with a glass filter, and the obtained solid was washed with water until the washing liquid became neutral. Thereafter, the solid was not dried (ie, in the presence of water), dispersed in 200 ml of chlorobenzene, heated to 50 ° C. and stirred for 10 hours. Thereafter, the dispersion was filtered off with a glass filter, and the obtained solid was vacuum-dried at 50 ° C. for 5 hours to obtain 4.1 g of blue powdery titanyl phthalocyanine (CGM2) crystals.

  The titanyl phthalocyanine (CGM2) crystal was immersed in 1,3-dioxolane or tetrahydrofuran for 7 days, and the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum was 7.4 before and after the immersion. It has no main peak at ° and 26.2 ° and no main peak of temperature change from 50 ° C to 400 ° C other than the peak around 90 ° C due to vaporization of adsorbed water. confirmed.

(Production Example 2)
(Formation of undercoat layer)
3 parts by weight of titanium oxide (Taika Co., Ltd., MT-100SAS (average particle size 15 nm)) surface-treated with silica, alumina and polyhydrogenpolysiloxane, and copolymerized polyamide resin (Toray Industries, Inc., “ 1 part by weight of Amilan CM8000 ”(registered trademark) was added to 12 parts by weight of methanol and 3 parts of butanol and dispersed using a paint shaker for 10 hours to prepare a coating solution for forming an undercoat layer.

The prepared coating solution for forming the undercoat layer is filtered with a 5 μm filter, and the filtrate is applied as a conductive substrate to an aluminum drum-shaped substrate having a diameter of 30 mm and a total length of 238.5 mm by a dip coating method. Then, heat treatment was performed at 130 ° C. for 30 minutes to form an undercoat layer having a thickness of 2 μm.
Example 1
(Formation of laminated photosensitive layer)
First, 1 part by weight of titanyl phthalocyanine (CGM2) obtained in Production Example 1 as a charge generator, 1 part by weight of a polyvinyl acetal resin (Sekisui Chemical Co., Ltd., ESREC KS-1) as a binder resin, and propylene glycol as a dispersion medium 64 parts by weight of monomethyl ether was mixed and dispersed for 48 hours by a ball mill to prepare a coating solution for forming a charge generation layer. The prepared coating solution for forming a charge generation layer is applied on the undercoat layer formed in Production Example 2 by a dip coating method and dried at 60 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.3 μm. Formed.

  Next, 70 parts by weight of a triphenylamine compound (corresponding to no. 1 in Table 1) represented by the following formula (HTM-1) as a hole transport agent, and represented by the following formula (Resin 1) as a binder resin. 100 parts by weight of a polycarbonate resin having a viscosity average molecular weight of 50000 and 460 parts by weight of tetrahydrofuran (THF) as an organic solvent were mixed and dissolved to prepare a coating solution for forming a charge transport layer.

  The prepared charge transport layer forming coating solution is applied onto the charge generation layer in the same manner as the charge generation layer forming coating solution, and heat-treated at 130 ° C. for 30 minutes to form a charge transport layer having a thickness of 20 μm. Then, a multilayer photosensitive layer was formed to produce a multilayer electrophotographic photosensitive member.

（比較例１）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−２）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

( Comparative Example 1 )
In Example 1, the laminated photosensitivity was the same as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-2). A layer was formed to produce a multilayer electrophotographic photosensitive member.

（比較例２）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−３）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

( Comparative Example 2 )
In Example 1, the laminated photosensitivity was the same as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-3). A layer was formed to produce a multilayer electrophotographic photosensitive member.

（比較例３）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−４）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

( Comparative Example 3 )
In Example 1, the laminated photosensitivity was the same as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-4). A layer was formed to produce a multilayer electrophotographic photosensitive member.

（実施例２）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−５）で表されるトリフェニルアミン系化合物（表１におけるｎｏ．２に相当）に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

(Example 2 )
In Example 1, except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound (corresponding to No. 2 in Table 1) represented by the following formula (HTM-5), A multilayer photosensitive layer was formed in the same manner as in Example 1 to produce a multilayer electrophotographic photoreceptor.

（実施例３）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−６）で表されるトリフェニルアミン系化合物（表１におけるｎｏ．３に相当）に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

(Example 3 )
In Example 1, except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound (corresponding to No. 3 in Table 1) represented by the following formula (HTM-6), A multilayer photosensitive layer was formed in the same manner as in Example 1 to produce a multilayer electrophotographic photoreceptor.

（実施例４）
製造例２における下引き層の形成において、共重合ポリアミド樹脂（東レ（株）製、「アミランＣＭ８０００」、（登録商標））を、共重合ポリアミド樹脂（ダイセル（株）製、ダイアミドＴ１７１）に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

(Example 4 )
In the formation of the undercoat layer in Production Example 2, the copolymerized polyamide resin (manufactured by Toray Industries, Inc., “Amilan CM8000”, (registered trademark)) was changed to a copolymerized polyamide resin (manufactured by Daicel Corporation, Daiamide T171). Except for the above, a multilayer photosensitive layer was formed in the same manner as in Example 1 to produce a multilayer electrophotographic photosensitive member.

( Comparative Example 4 )
In Example 4 , the laminated photosensitivity was the same as in Example 4 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound represented by the above formula (HTM-2). A layer was formed to produce a multilayer electrophotographic photosensitive member.

(Example 5 )
In Example 1, a laminated photosensitive layer was formed in the same manner as in Example 1 except that the polycarbonate resin (Resin 1) was changed to a polycarbonate resin represented by the following formula (Resin 2) having a viscosity average molecular weight of 49500. A multilayer electrophotographic photosensitive member was produced.

（比較例５）
実施例５において、トリフェニルアミン系化合物（ＨＴＭ−１）を、上記式（ＨＴＭ−２）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例５と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

( Comparative Example 5 )
In Example 5, triphenylamine compound (HTM-1), except for changing the triphenylamine compound represented by the formula (HTM-2), likewise multi-layer type photosensitive Example 5 A layer was formed to produce a multilayer electrophotographic photosensitive member.

(Example 6 )
In the formation of the undercoat layer in Production Example 2, the aluminum drum-like substrate was changed to an alumite drum-like substrate, and the undercoat layer-forming coating solution was not applied, as in Example 1. A multilayer photosensitive layer was formed to produce a multilayer electrophotographic photoreceptor. In this case, the alumite drum-shaped substrate is obtained by forming an alumite film having a thickness of 5 μm on an aluminum drum-shaped substrate by anodizing treatment.

( Comparative Example 6 )
In Example 6, triphenylamine compound (HTM-1), except for changing the triphenylamine compound represented by the formula (HTM-2), likewise multi-layer type photosensitive Example 6 A layer was formed to produce a multilayer electrophotographic photosensitive member.

(Comparative Example 7 )
In Example 1, a laminated photosensitive layer was obtained in the same manner as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-7). To form a multilayer electrophotographic photosensitive member.
A part of the multilayer photosensitive layer formed on the multilayer electrophotographic photosensitive member was crystallized.

（比較例８）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−８）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

(Comparative Example 8 )
In Example 1, a laminated photosensitive layer was obtained in the same manner as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-8). To form a multilayer electrophotographic photosensitive member.

  Note that the multilayer photosensitive layer formed on the multilayer electrophotographic photosensitive member was remarkably crystallized.

（比較例９）
実施例１において、トリフェニルアミン系化合物（ＨＴＭ−１）を、下記式（ＨＴＭ−９）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例１と同様に積層型感光層を形成し、積層型電子写真感光体を作製した。

(Comparative Example 9 )
In Example 1, a laminated photosensitive layer was obtained in the same manner as in Example 1 except that the triphenylamine compound (HTM-1) was changed to a triphenylamine compound represented by the following formula (HTM-9). To form a multilayer electrophotographic photosensitive member.

  A part of the multilayer photosensitive layer formed on the multilayer electrophotographic photosensitive member was crystallized.

（画像形成評価）
各実施例および比較例において作製した積層型電子写真感光体を、市販の負帯電反転現像プロセスを採用したプリンタ（沖データ（株）製、ＭｉｃｒｏＬｉｎｅ−１８）の感光体ドラムとして採用して、３５℃／８５％ＲＨにおける高温高湿環境下（以下、「Ｈ／Ｈ環境」という。）にて、画像形成および電気特性を評価した。なお、このプリンタ（沖データ製、ＭｉｃｒｏＬｉｎｅ−１８）は、帯電ローラと、露光器と、現像器と、転写ローラと、を有しており、除電器を有していない（図１参照）。

(Image formation evaluation)
The laminated electrophotographic photosensitive member produced in each example and comparative example was employed as a photosensitive drum of a printer (Microline-18, manufactured by Oki Data Co., Ltd.) employing a commercially available negative charge reversal development process. Image formation and electrical characteristics were evaluated in a high-temperature and high-humidity environment (hereinafter referred to as “H / H environment”) at ° C./85% RH. Note that this printer (Okidata, MicroLine-18) has a charging roller, an exposure device, a developing device, and a transfer roller, and does not have a static eliminator (see FIG. 1).

In the image formation evaluation, image formation processing of a solid black image, a gray image, and a blank paper image was performed in an H / H environment, and the presence or absence of fogging and the presence or absence of a memory effect were visually observed.
In the electrical property evaluation, a residual potential V _L (V) corresponding to a solid black portion at the development position and an initial surface potential V ₀ (V) were measured. The smaller the numerical value of the residual potential _VL, the better the sensitivity.
The results are shown in Table 2.

表２中、Ｈ／Ｈ画像形成評価における「かぶり」の欄中、「◎」は、Ｈ／Ｈ環境における画像形成処理後、用紙上に、かぶりが全く観察されなかった場合、「○」はかぶりが多少観察されたものの、実用上問題のない程度であった場合、「△」はかぶりが一部観察された場合を示し、また、「メモリ」の欄中、「◎」は、Ｈ／Ｈ環境における画像形成処理で、感光体ドラムの回転１周目に形成された黒ベタ画像のゴーストが、感光体ドラムの回転２周目に形成されたグレー画像中において、ゴーストが観察されなかった場合、「○」はゴーストが多少観察されたものの、実用上問題のない程度あった場合を示す。

In Table 2, in the “fogging” column in the H / H image formation evaluation, “◎” indicates that no fogging was observed on the paper after image forming processing in the H / H environment. When fogging was observed to some extent but there was no problem in practical use, “△” indicates that a part of the fogging was observed, and “◎” in the “Memory” column represents H / In the image forming process in the H environment, the ghost of the black solid image formed on the first rotation of the photosensitive drum was not observed in the gray image formed on the second rotation of the photosensitive drum. In this case, “◯” indicates a case where ghost was observed to some extent, but there was no practical problem.

(Production Example 3)
(Formation of undercoat layer)
In Production Example 2, subtraction is performed in the same manner as in Production Example 2 except that the aluminum drum-shaped substrate having a diameter of 30 mm and the total length of 238.5 mm is changed to an aluminum drum-shaped substrate having a diameter of 16 mm and a total length of 244.5 mm. A layer was formed.

(Example 7 )
(Formation of single-layer type photosensitive layer)
First, 3 parts by weight of x-type metal-free phthalocyanine (CGM1) as a charge generating agent, and a triphenylamine compound represented by the above formula (HTM-1) as a hole transporting agent (corresponding to no. 1 in Table 1) 50 parts by weight, 40 parts by weight of an azoquinone derivative represented by the following formula (ETM10-1) as an electron transfer agent, 100 parts by weight of a polycarbonate resin (Resin 1) as a binder resin, and 800 parts by weight of tetrahydrofuran as an organic solvent, For 50 hours to prepare a coating solution for forming a photosensitive layer. Next, the prepared photosensitive layer forming coating solution is applied on the undercoat layer formed in Production Example 3 by the dip coating method, and then dried with hot air at 130 ° C. for 40 minutes to charge transport with a thickness of 25 μm. A single layer type photosensitive layer was formed to form a single layer type electrophotographic photosensitive member.

（比較例１０）
実施例７において、トリフェニルアミン系化合物（ＨＴＭ−１）を、上記式（ＨＴＭ−２）で表されるトリフェニルアミン系化合物に変更したこと以外は、実施例７と同様に単層型感光層を形成し、単層型電子写真感光体を作製した。

( Comparative Example 10 )
In Example 7 , the triphenylamine compound (HTM-1) was changed to the triphenylamine compound represented by the above formula (HTM-2), and the same as in Example 7 , the single layer type A photosensitive layer was formed to produce a single layer type electrophotographic photosensitive member.

( Comparative Example 11 )
In Example 7 , the triphenylamine compound (HTM-1) was changed to the triphenylamine compound represented by the above formula (HTM-3), and the single layer type was obtained in the same manner as in Example 7. A photosensitive layer was formed to produce a single layer type electrophotographic photosensitive member.

( Comparative Example 12 )
In Example 7 , the single-layer type was used in the same manner as in Example 7 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound represented by the above formula (HTM-4). A photosensitive layer was formed to produce a single layer type electrophotographic photosensitive member.

(Example 8 )
In Example 7 , except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (corresponding to No. 2 in Table 1) represented by the above formula (HTM-5), A single layer type photosensitive layer was formed in the same manner as in Example 7 to prepare a single layer type electrophotographic photosensitive member.

(Example 9 )
In Example 7 , except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (corresponding to No. 3 in Table 1) represented by the above formula (HTM-6), A single layer type photosensitive layer was formed in the same manner as in Example 7 to prepare a single layer type electrophotographic photosensitive member.

(Example 10 )
In Example 7 , a monolayer type photosensitive layer was formed in the same manner as in Example 7 except that the azoquinone derivative (ETM10-1) was changed to a naphthoquinone derivative (ETM4-1). Was made.

（実施例１１）
実施例７において、アゾキノン誘導体（ＥＴＭ１０−１）を、ナフトキノン誘導体（ＥＴＭ４−２）に変更したこと以外は、実施例７と同様に単層型感光層を形成し、単層型電子写真感光体を作製した。

(Example 11 )
In Example 7 , a single-layer type electrophotographic photosensitive member was formed by forming a single-layer type photosensitive layer in the same manner as in Example 7 except that the azoquinone derivative (ETM10-1) was changed to a naphthoquinone derivative (ETM4-2). Was made.

（実施例１２）
実施例７において、アゾキノン誘導体（ＥＴＭ１０−１）を、ジフェノキノン誘導体（ＥＴＭ１−１）に変更したこと以外は、実施例７と同様に単層型感光層を形成し、単層型電子写真感光体を作製した。

(Example 12 )
In Example 7 , a single layer type electrophotographic photosensitive member was formed by forming a single layer type photosensitive layer in the same manner as in Example 7 except that the azoquinone derivative (ETM10-1) was changed to the diphenoquinone derivative (ETM1-1). Was made.

（実施例１３）
実施例７において、アゾキノン誘導体（ＥＴＭ１０−１）を、ジナフトキノン誘導体（ＥＴＭ８−１）に変更したこと以外は、実施例７と同様に単層型感光層を形成し、単層型電子写真感光体を作製した。

(Example 13 )
In Example 7 , a single layer type photosensitive layer was formed in the same manner as in Example 7 except that the azoquinone derivative (ETM10-1) was changed to a dinaphthoquinone derivative (ETM8-1), and a single layer type electrophotographic photosensitive member was formed. The body was made.

（実施例１４）
実施例１１において、ポリカーボネート樹脂（Ｒｅｓｉｎ１）を、ポリカーボネート樹脂（Ｒｅｓｉｎ２）に変更したこと以外は、実施例１１と同様に単層型感光層を形成し、単層型電子写真感光体を作製した。

(Example 14 )
In Example 11 , except that the polycarbonate resin (Resin 1) was changed to the polycarbonate resin (Resin 2), a single layer type photosensitive layer was formed in the same manner as in Example 11 to prepare a single layer type electrophotographic photosensitive member.

( Comparative Example 13 )
In Example 14 , a single-layer type photosensitive layer was formed in the same manner as in Example 14 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (HTM-2). A layer type electrophotographic photosensitive member was produced.
(Comparative Example 14 )
In Example 7 , a monolayer type photosensitive layer was formed in the same manner as in Example 7 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (HTM-7). A layer type electrophotographic photosensitive member was produced.

The single layer type photosensitive layer formed on the single layer type electrophotographic photosensitive member was slightly crystallized throughout.
(Comparative Example 15 )
In Example 10 , a monolayer type photosensitive layer was formed in the same manner as in Example 10 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (HTM-8). A layer type electrophotographic photosensitive member was produced.

The single layer type photosensitive layer formed on the single layer type electrophotographic photosensitive member was remarkably crystallized.
(Comparative Example 16 )
In Example 11 , a single-layer type photosensitive layer was formed in the same manner as in Example 11 except that the triphenylamine compound (HTM-1) was changed to the triphenylamine compound (HTM-9). A layer type electrophotographic photosensitive member was produced.

The single layer type photosensitive layer formed on the single layer type electrophotographic photosensitive member was slightly crystallized throughout.
(Image formation evaluation)
The single layer type electrophotographic photosensitive member produced in each example and each comparative example was employed as a photosensitive drum of a printer (Kyocera Mita Co., Ltd., printer DP-560) to evaluate electrical characteristics and solvent resistance test. And image formation evaluation was performed. The rotational speed of the photosensitive drum of this image forming apparatus was a peripheral speed of 60 mm / sec, and the light amount was 1.0 μJ / cm ² . Further, the charge eliminating lamp was excluded from the image forming apparatus. The printer is an image forming apparatus based on a simultaneous development cleaning system, and includes a contact charger (roller charging type), an exposure device, a developing device, and a transfer roller. I don't have it.

In the electrical property evaluation, a residual potential VL (V) corresponding to the black solid portion potential at the development position was measured.
For image formation evaluation, plain paper (A4 size) is used as the paper, the main charging potential is set to +850 V, the development bias voltage is set to +400 V, and the image formation processing (printing rate 5%) cycle by reverse development is performed through the plain paper. Repeatedly, the image formation when 100,000 sheets were printed was visually evaluated.

In the solvent resistance test evaluation, the photosensitive drum was immersed in 500 ml of a paraffinic solvent for wet developer (ExxonMobil Chemical Co., Ltd., normal paraffin, trade name “NOPA 12”) at 25 ° C. for 200 hours. Immersion was performed in a closed system in a dark place, and after 200 hours, the sensitivity change before and after immersion was evaluated.
The results are shown in Table 3.

表３中、画像形成評価の欄中、「◎」は用紙上に黒点が観測されなかった場合、「○」は用紙上に黒点がわずかに観測されたものの、実用上問題のない程度であった場合、「×」は用紙上に黒点が観測された場合を示す。比較例７の「評価不能」とは、クラックが多数発生して、感度測定ができなかったことを示す。

In Table 3, in the column of image formation evaluation, “◎” indicates that no black spots were observed on the paper, and “◯” indicates that black spots were slightly observed on the paper, but there was no practical problem. In this case, “x” indicates a case where a black spot is observed on the paper. “Non-evaluable” in Comparative Example 7 indicates that many cracks occurred and sensitivity measurement could not be performed.

(Evaluation results)
As can be seen from Table 2, in Example 1-6, the specific hole transporting agent a photosensitive drum laminate type photosensitive layer is formed comprising the present invention, and a photosensitive drum of Comparative Examples 1 to 6 Compared with the photosensitive drums of Comparative Examples 7 to 9 , the electrical characteristics in the H / H environment were almost the same, but no ghost due to the memory effect occurred, whereas the photosensitive bodies of Comparative Examples 7 to 9 The drum was ghosted by the memory effect. The photosensitive drums of Comparative Examples 7 to 9 were crystallized at the time of forming the laminated photosensitive layer, but the photosensitive drums of Examples 1 to 6 and Comparative Examples 1 to 6 were not crystallized.

Further, as can be seen from Table 3, the photosensitive drums of Examples 7 to 14 on which the single-layer type photosensitive layer containing the specific hole transport agent according to the present invention was formed, and the photosensitivity of Comparative Examples 10 to 13 were used. The body drum had a lower residual potential and higher sensitivity in the electrical property evaluation than the photosensitive drums of Comparative Examples 14 to 16 . Further, the photosensitive drum of Comparative Examples 14-16, in the formation of single-layer type photosensitive layer, was crystallized, Examples 7-14, the photosensitive drum of Comparative Example 10 to 13, did not crystallize.
Further, as can be seen from both tables, the photosensitive layers of Examples 1 to 14 containing the specific hole transport agent according to the present invention always gave good results in various configurations of a laminated type and a single layer type. However, the photoreceptors of Comparative Examples 1 to 6 and Comparative Examples 10 to 13 did not always give good results.

1 is a schematic configuration diagram of an image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Exposure device 4 Developing device 5 Transfer roller 7 Paper 10 Image forming apparatus

Claims (5)

A photosensitive layer comprising a charge generating agent, a charge transport agent and a binder resin on a conductive substrate, wherein the charge transport agent is a triphenylamine compound represented by the following general formula (1): An electrophotographic photoreceptor.

(In General Formula (1), R ¹ represents an alkyl group having 2 to 6 carbon atoms. R ² represents an alkyl group having 1 to 6 carbon atoms .
R ⁶ and R ⁷ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.
R ⁸ and R ⁹ are the same or different and each represents hydrogen or an alkyl group having 1 to 6 carbon atoms.
a to d are the same or different and are integers of 0 to 5, respectively . ) The photosensitive layer is a single photosensitive layer containing the charge generating agent, the charge transporting agent, and the binder resin, and is formed on the conductive substrate directly or via an intermediate layer. The electrophotographic photosensitive member according to claim 1, wherein: The photosensitive layer is a laminate including a charge generating layer containing the charge generating agent and the binder resin, and a charge transporting layer containing the charge transporting agent and the binder resin, and on the conductive substrate, 2. The electrophotographic photosensitive member according to claim 1 , wherein the electrophotographic photosensitive member is formed directly or via an intermediate layer. Image carrying means;
Charging means for charging the surface of the image carrying means;
Exposure means for exposing the surface of the image carrying means to form an electrostatic latent image;
Developing means for developing the electrostatic latent image as a toner image;
A transfer means for transferring the toner image from the image carrying means to a transfer medium, and
In an image forming apparatus having no charge eliminating means for removing charges on the surface of the image carrying means,
The image bearing means, characterized in that it is an electrophotographic photosensitive member according to any one of claims 1 to 3, the image forming apparatus. The image forming apparatus according to claim 4 , wherein the charging unit is a charging roller.

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