JP2022033542A - Electrophotographic photoreceptor and method for manufacturing the same, and image forming apparatus - Google Patents

Electrophotographic photoreceptor and method for manufacturing the same, and image forming apparatus Download PDF

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JP2022033542A
JP2022033542A JP2020137498A JP2020137498A JP2022033542A JP 2022033542 A JP2022033542 A JP 2022033542A JP 2020137498 A JP2020137498 A JP 2020137498A JP 2020137498 A JP2020137498 A JP 2020137498A JP 2022033542 A JP2022033542 A JP 2022033542A
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electrophotographic photosensitive
photosensitive member
surface layer
layer
charge
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一国 西村
Kazukuni Nishimura
誠亮 前田
Seisuke Maeda
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Konica Minolta Inc
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Abstract

To provide an electrophotographic photoreceptor that is excellent in charge stability, wear resistance, and image memory resistance for a long period.SOLUTION: An electrophotographic photoreceptor has a conductive support, a photosensitive layer arranged on the conductive support, and a surface layer arranged on the photosensitive layer. The surface layer includes a thermoplastic resin having electron receptivity and having a glass-transition temperature of 225°C or more and 350°C or less, and a charge transport material.SELECTED DRAWING: None

Description

本発明は、電子写真感光体およびその製造方法、ならびに画像形成装置に関する。 The present invention relates to an electrophotographic photosensitive member, a method for producing the same, and an image forming apparatus.

従来、画像形成装置用の電子写真感光体として、導電性支持体と、当該導電性支持体上に配置された感光層と、を有する電子写真感光体がよく知られている。このような導電性支持体における感光層は、電荷発生物質と電荷輸送物質とを含むことが一般的である。近年、電気的外力および機械的外力への耐性を高めるため、感光層の表面に、さらに表面層を配置することが検討されている。 Conventionally, as an electrophotographic photosensitive member for an image forming apparatus, an electrophotographic photosensitive member having a conductive support and a photosensitive layer arranged on the conductive support is well known. The photosensitive layer in such a conductive support generally contains a charge generating substance and a charge transporting substance. In recent years, in order to increase the resistance to electrical and mechanical external forces, it has been studied to further arrange a surface layer on the surface of the photosensitive layer.

ただし、感光層上に表面層を配置すると、電子写真感光体の帯電安定性が低下しやすいという課題があった。特に、電子写真感光体に帯電部材を接触させる場合、電子写真感光体を均一に帯電させることが難しく、画像白地部にトナーかぶりが発生しやすかった。そこで、表面層に電子供与性化合物および低分子量の電子受容性化合物を含有させて、表面層の帯電安定性を高めることが提案されている(特許文献1)。 However, when the surface layer is arranged on the photosensitive layer, there is a problem that the charge stability of the electrophotographic photosensitive member tends to decrease. In particular, when the charging member is brought into contact with the electrophotographic photosensitive member, it is difficult to uniformly charge the electrophotographic photosensitive member, and toner fog is likely to occur on the white background of the image. Therefore, it has been proposed to include an electron donating compound and a low molecular weight electron accepting compound in the surface layer to enhance the charge stability of the surface layer (Patent Document 1).

一方、表面層の機械的外力を高めるため、ガラス転移温度の高い樹脂を表面層に含めることも検討されている。表面層が、ポリイミド等、ガラス転移温度の高い樹脂を含むと、電子写真感光体の摩耗が低減されやすく、感光体の寿命が長くなりやすい。例えば、特許文献2には、ポリイミド酸の前駆体であるポリアミック酸を電荷輸送層等の上に塗布した後、ポリアミック酸をイミド化して表面層を形成する方法が記載されている。特許文献3には、可溶性ポリイミド樹脂を塗布して表面層を形成することが記載されている(特許文献3)。 On the other hand, in order to increase the mechanical external force of the surface layer, it is also considered to include a resin having a high glass transition temperature in the surface layer. When the surface layer contains a resin having a high glass transition temperature such as polyimide, the wear of the electrophotographic photosensitive member is likely to be reduced and the life of the photoconductor is likely to be extended. For example, Patent Document 2 describes a method of applying a polyamic acid, which is a precursor of a polyimide acid, onto a charge transport layer or the like, and then imidizing the polyamic acid to form a surface layer. Patent Document 3 describes that a soluble polyimide resin is applied to form a surface layer (Patent Document 3).

特開2000-3051号公報Japanese Unexamined Patent Publication No. 2000-3051 特開平6-222602号公報Japanese Unexamined Patent Publication No. 6-22262 特開2006-18153号公報Japanese Unexamined Patent Publication No. 2006-18153

しかしながら、本発明者らが検討したところ、上述の特許文献1の方法では、電子写真感光体を繰り返し使用した際に、電気的外力によって、表面層中の電子受容性化合物が溶出しやすく、経時で帯電安定性が低下することが明らかとなった。さらに、低分子量の電子受容性化合物は、バインダー樹脂等と相溶性が低く、表面層中で偏在したり、表面層から析出したりしやすかった。このような偏在や析出が生じると、電子受容性化合物が、電荷をトラップしやすく、画像メモリーが発生することがあった。 However, as a result of studies by the present inventors, in the method of Patent Document 1 described above, when the electrophotographic photosensitive member is repeatedly used, the electron-accepting compound in the surface layer is easily eluted by an electrical external force, and over time. It was clarified that the charge stability was lowered. Further, the low molecular weight electron-accepting compound has low compatibility with the binder resin and the like, and is easily unevenly distributed in the surface layer or precipitated from the surface layer. When such uneven distribution or precipitation occurs, the electron-accepting compound tends to trap charges, and an image memory may be generated.

また、特許文献2の方法では、ポリアミック酸をイミド化するために加熱が行われる。しかしながら、感光層等に影響を及ぼすことなく、高温まで加熱することが難しく、イミド化が不十分になりやすかった。そのため、未反応の極性基が表面層中に残存し、高温高湿環境での像流れを引き起こしやすかった。さらに、特許文献2の方法で作製される表面層では、電荷輸送性能が不十分であり、画像メモリーも発生しやすかった。さらに、特許文献3の方法では、像流れは生じ難いものの、ポリイミド樹脂の存在によって、電子写真感光体表面の帯電性が不安定になりやすい。したがって、画像白地部にトナーかぶりが発生しやすかった。 Further, in the method of Patent Document 2, heating is performed in order to imidize the polyamic acid. However, it is difficult to heat to a high temperature without affecting the photosensitive layer and the like, and imidization tends to be insufficient. Therefore, unreacted polar groups remained in the surface layer, and it was easy to cause image flow in a high temperature and high humidity environment. Further, the surface layer produced by the method of Patent Document 2 has insufficient charge transport performance and tends to generate an image memory. Further, in the method of Patent Document 3, although image flow is unlikely to occur, the chargeability of the surface of the electrophotographic photosensitive member tends to be unstable due to the presence of the polyimide resin. Therefore, toner fog is likely to occur on the white background of the image.

本発明は、このような課題を鑑みてなされたものである。長期に亘って帯電安定性や耐摩耗性が優れ、さらに画像メモリー耐性にも優れた電子写真感光体や、これを含む画像形成装置、さらには電子写真感光体の製造方法の提供を課題とする。 The present invention has been made in view of such problems. An object of the present invention is to provide an electrophotographic photosensitive member having excellent charge stability and abrasion resistance over a long period of time and also having excellent image memory resistance, an image forming apparatus including the electrophotographic photosensitive member, and a method for manufacturing the electrophotographic photosensitive member. ..

本発明は、以下の電子写真感光体を提供する。
導電性支持体と、前記導電性支持体上に配置された感光層と、前記感光層上に配置された表面層と、を有し、前記表面層が、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂と、電荷輸送物質と、を含む、電子写真感光体。
The present invention provides the following electrophotographic photosensitive members.
It has a conductive support, a photosensitive layer arranged on the conductive support, and a surface layer arranged on the photosensitive layer, and the surface layer has electron acceptability and is glass. An electrophotographic photosensitive member comprising a thermoplastic resin having a transition temperature of 225 ° C. or higher and 350 ° C. or lower, and a charge transporting substance.

本発明は、以下の画像形成装置も提供する。
前述の電子写真感光体と、前記電子写真感光体を帯電させるための接触帯電部材と、を有する、画像形成装置。
The present invention also provides the following image forming apparatus.
An image forming apparatus having the above-mentioned electrophotographic photosensitive member and a contact charging member for charging the electrophotographic photosensitive member.

本発明は、電子写真感光体の製造方法を提供する。
導電性支持体上に感光層を配置する工程と、前記感光層上に、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂、電荷輸送物質、および沸点が40℃以上150℃以下である溶媒を含む表面層組成物を塗布し、表面層を形成する工程と、を有する、電子写真感光体の製造方法。
The present invention provides a method for manufacturing an electrophotographic photosensitive member.
A step of arranging a photosensitive layer on a conductive support, a thermoplastic resin having electron acceptability on the photosensitive layer and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, a charge transporting substance, and a boiling point. A method for producing an electrophotographic photosensitive member, comprising a step of applying a surface layer composition containing a solvent having a temperature of 40 ° C. or higher and 150 ° C. or lower to form a surface layer.

本発明の電子写真感光体は、長期に亘って帯電安定性、耐摩耗性および画像メモリー耐性に優れる。 The electrophotographic photosensitive member of the present invention is excellent in charge stability, abrasion resistance and image memory resistance for a long period of time.

図1は、本発明の画像形成装置の一例を示す模式図である。FIG. 1 is a schematic view showing an example of the image forming apparatus of the present invention.

以下、本発明の一実施の形態について詳細に説明する。ただし、本発明は当該実施の形態に限定されない。 Hereinafter, an embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiment.

1.電子写真感光体
本発明の電子写真感光体は、電子写真感光方式の画像形成装置に使用するための電子写真感光体である。当該電子写真感光体は、導電性支持体と、感光層と、表面層と、を有する。ただし、本発明の目的および効果を損なわない範囲において、上記以外の構成を含んでいてもよい。例えば導電性支持体と感光層との間に必要に応じて中間層等の他の層を有していてもよい。
1. 1. Electrophotographic Photoreceptor The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member for use in an electrophotographic photosensitive type image forming apparatus. The electrophotographic photosensitive member has a conductive support, a photosensitive layer, and a surface layer. However, configurations other than the above may be included as long as the object and effect of the present invention are not impaired. For example, another layer such as an intermediate layer may be provided between the conductive support and the photosensitive layer, if necessary.

上述のように、従来の電子写真感光体では、表面層に耐熱性の高い樹脂を含めることで、電子写真感光体の耐摩耗性等を高めようとしていた。しかしながら、当該方法では、電子写真感光体の帯電安定性が低くなりやすく、画像にかぶり等が発生しやすかった。さらに、樹脂の種類によっては、電荷輸送性能が不十分であり、画像メモリーが発生しやすかった。一方で、表面層の帯電安定性を高めるために、電子供与性化合物や低分子量の電子受容性化合物を含めること等も提案されている。しかしながら、電気的外力によってこれらの化合物が溶出しやすく、従来の方法では、帯電安定性を長期間に亘って高めることが難しかった。 As described above, in the conventional electrophotographic photosensitive member, the wear resistance and the like of the electrophotographic photosensitive member have been improved by including a resin having high heat resistance in the surface layer. However, in this method, the charge stability of the electrophotographic photosensitive member tends to be low, and fog or the like is likely to occur in the image. Further, depending on the type of resin, the charge transport performance is insufficient, and an image memory is likely to occur. On the other hand, in order to enhance the charge stability of the surface layer, it has been proposed to include an electron donating compound or a low molecular weight electron accepting compound. However, these compounds are easily eluted by an external electric force, and it has been difficult to improve the charge stability over a long period of time by the conventional method.

そこで、本発明の電子写真感光体では、表面層が、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂と、電荷輸送物質と、を含む。一般的な電子写真感光体では、負に帯電した気体分子が、感光体表面に吸着することで帯電する。一方、本発明では、表面層中の熱可塑性樹脂が電子受容性を有することから、負電荷が熱可塑性樹脂のLUMOに注入されて帯電する。そのため、負電荷が安定しやすく、電子写真感光体の帯電安定性が従来と比較して非常に高くなる。つまり、当該電子写真感光体では、画像白地部にトナーかぶりが生じ難い。 Therefore, in the electrophotographic photosensitive member of the present invention, the surface layer contains a thermoplastic resin having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, and a charge transporting substance. In a general electrophotographic photosensitive member, negatively charged gas molecules are charged by adsorbing on the surface of the photosensitive member. On the other hand, in the present invention, since the thermoplastic resin in the surface layer has electron acceptability, a negative charge is injected into the LUMO of the thermoplastic resin to be charged. Therefore, the negative charge is easy to stabilize, and the charge stability of the electrophotographic photosensitive member becomes very high as compared with the conventional case. That is, in the electrophotographic photosensitive member, toner fog is unlikely to occur on the white background of the image.

また、本発明では、電子受容性を有する構造が、熱可塑性樹脂に担持されている。そのため、電子写真感光体を繰り返し使用したとしても、電子受容性を有する構造が電子写真感光体から溶出し難い。したがって、長期間に亘って、優れた帯電安定性を維持できる。 Further, in the present invention, a structure having electron acceptability is supported on the thermoplastic resin. Therefore, even if the electrophotographic photosensitive member is used repeatedly, it is difficult for the electron-accepting structure to elute from the electrophotographic photosensitive member. Therefore, excellent charge stability can be maintained for a long period of time.

さらに、従来の低分子量の電子受容性化合物は、表面層内で偏在しやすく、偏在した電子受容性化合物が表面層内を移動する電荷をトラップしてしまうことがあった。これに対し、本発明では、電子受容性を有する構造が熱可塑性樹脂に担持されていることから、当該構造が表面層内で偏在し難い。したがって、上記のような電荷のトラップが生じ難く、画像メモリーも生じ難い。 Further, the conventional low molecular weight electron-accepting compound tends to be unevenly distributed in the surface layer, and the unevenly distributed electron-accepting compound may trap the electric charge moving in the surface layer. On the other hand, in the present invention, since the structure having electron acceptability is supported on the thermoplastic resin, it is difficult for the structure to be unevenly distributed in the surface layer. Therefore, the charge trap as described above is unlikely to occur, and the image memory is also unlikely to occur.

さらに、表面層が含む熱可塑性樹脂は、そのガラス転移温度が225℃以上350℃以下である。そのため、電子写真感光体を繰り返し使用したとしても、摩耗し難く、長期間に亘って、安定して使用可能である。以下、本発明の電子写真感光体の各構成について説明する。 Further, the thermoplastic resin contained in the surface layer has a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower. Therefore, even if the electrophotographic photosensitive member is used repeatedly, it is not easily worn and can be used stably for a long period of time. Hereinafter, each configuration of the electrophotographic photosensitive member of the present invention will be described.

(1)導電性支持体
本発明で用いられる支持体は、導電性を有し、かつ感光層を支持可能であればよく、例えば円筒状または円柱状の構造体である。導電性支持体の大きさは電子写真感光体の用途に応じて適宜選択される。また、導電性支持体の材料は特に制限されない。
(1) Conductive Support The support used in the present invention may be any as long as it has conductivity and can support the photosensitive layer, and is, for example, a cylindrical or columnar structure. The size of the conductive support is appropriately selected according to the application of the electrophotographic photosensitive member. Further, the material of the conductive support is not particularly limited.

導電性支持体の例には、アルミニウム、銅、クロム、ニッケル、亜鉛、ステンレス等の金属をドラム状またはシート状に成形したもの;アルミニウムや銅等の金属箔をドラム状またはシート状のプラスチックフィルムにラミネートしたもの;アルミニウム、酸化インジウムおよび酸化スズ等をドラム状またはシート状のプラスチックフィルムに蒸着したもの;ドラム状またはシート状の金属、プラスチック、または紙の上に、導電性物質単独、または導電性物質およびバインダー樹脂を含む組成物を塗布して導電層を設けたもの;等が含まれる。 Examples of conductive supports are metal such as aluminum, copper, chrome, nickel, zinc, and stainless steel molded into a drum or sheet; metal foil such as aluminum or copper is formed into a drum or sheet plastic film. Laminated on; Aluminum, indium oxide, tin oxide, etc. deposited on a drum-shaped or sheet-shaped plastic film; Conductive substance alone or conductive on a drum-shaped or sheet-shaped metal, plastic, or paper A composition containing a sex substance and a binder resin is applied to provide a conductive layer; and the like are included.

(2)感光層
感光層は、電荷発生可能な電荷発生物質、および電荷輸送性を有する電荷輸送物質を含んでいればよく、例えば電荷発生物質を含む電荷発生層と、電荷輸送物質を含む電荷輸送層と、から構成されていてもよい。一方で、電荷発生物質と電荷輸送物質とを、1つの層(電荷発生・輸送層)内に含んでいてもよい。ただし、電荷発生層および電荷輸送層が別々に構成されているほうが、電子写真感光体を繰り返し使用した際に、残留電位が上昇し難く、さらに電子写真感光体の目的に応じて、各層の特性を制御しやすい。以下、電荷発生層および電荷輸送層を別々に形成する場合を例に説明するが、本発明の電子写真感光体の感光層は、当該態様に限定されない。
(2) Photosensitive layer The photosensitive layer may contain a charge generating substance capable of generating charges and a charge transporting substance having a charge transporting property. For example, a charge generating layer containing a charge generating substance and a charge containing a charge transporting substance. It may be composed of a transport layer. On the other hand, the charge generating substance and the charge transporting substance may be contained in one layer (charge generating / transporting layer). However, if the charge generation layer and the charge transport layer are separately configured, the residual potential is less likely to increase when the electrophotographic photosensitive member is used repeatedly, and the characteristics of each layer are different depending on the purpose of the electrophotographic photosensitive member. Easy to control. Hereinafter, the case where the charge generation layer and the charge transport layer are separately formed will be described as an example, but the photosensitive layer of the electrophotographic photosensitive member of the present invention is not limited to this embodiment.

(電荷発生層)
電荷発生層は、光の照射によって、電荷の発生が可能な層であればよく、例えば電荷発生物質とバインダー樹脂とを含有する層である。
(Charge generation layer)
The charge generation layer may be any layer as long as it can generate charges by irradiation with light, and is, for example, a layer containing a charge generation substance and a binder resin.

電荷発生物質は特に制限されず、公知の電荷発生物質を使用可能である。その例には、スーダンレッドやダイアンブルー等のアゾ原料;ピレンキノンやアントアントロン等のキノン顔料;キノシアニン顔料;ペリレン顔料;インジゴ、チオインジゴ等のインジゴ顔料;チタニルフタロシアニン等のフタロシアニン顔料等が含まれる。電荷発生層は、これらの電荷発生物質を1種のみ含んでいてもよく、2種以上含んでいてもよい。 The charge generating substance is not particularly limited, and a known charge generating substance can be used. Examples thereof include azo raw materials such as Sudan Red and Diane Blue; quinone pigments such as pyrenequinone and anthanthrone; quinosianin pigments; perylene pigments; indigo pigments such as indigo and thioindigo; and phthalocyanine pigments such as titanylphthalocyanine. The charge generation layer may contain only one kind of these charge generation substances, or may contain two or more kinds of these charge generation substances.

一方、バインダー樹脂も公知の樹脂を使用可能である。その例には、ポリスチレン樹脂、ポリエチレン樹脂、ポリプロピレン樹脂、アクリル樹脂、メタクリル樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、ポリビニルブチラール樹脂、エポキシ樹脂、ポリウレタン樹脂、フェノール樹脂、ポリエステル樹脂、アルキッド樹脂、ポリカーボネート樹脂、シリコーン樹脂、メラミン樹脂、ポリビニルカルバゾール樹脂、およびこれらの共重合体(例えば、塩化ビニル-酢酸ビニル共重合体樹脂、塩化ビニル-酢酸ビニル-無水マレイン酸共重合体樹脂等)等が含まれる。電荷発生層は、これらのバインダー樹脂を1種のみ含んでいてもよく、2種以上含んでいてもよい。 On the other hand, a known resin can be used as the binder resin. Examples thereof include polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, etc. Silicone resin, melamine resin, polyvinylcarbazole resin, and copolymers thereof (for example, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, etc.) and the like are included. The charge generation layer may contain only one kind of these binder resins, or may contain two or more kinds of these binder resins.

電荷発生層中の電荷発生物質の量は、バインダー樹脂100質量部に対して1質量部以上600質量部以下が好ましく、50質量部以上500質量部以下がより好ましい。電荷発生物質の量が当該範囲であると、十分な量の電荷を発生させることができる。 The amount of the charge generating substance in the charge generating layer is preferably 1 part by mass or more and 600 parts by mass or less, and more preferably 50 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount of the charge generating substance is in the range, a sufficient amount of charge can be generated.

電荷発生層の膜厚は、電荷発生物質の特性、バインダー樹脂の特性や混合割合等により適宜選択されるが、0.01μm以上5μm以下が好ましく、0.05μm以上3μm以下がより好ましい。電荷発生層の膜厚が当該範囲であると、電荷発生能が安定しやすく、さらに十分に強度の高い層とすることができる。 The film thickness of the charge generating layer is appropriately selected depending on the characteristics of the charge generating substance, the characteristics of the binder resin, the mixing ratio, and the like, but is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.05 μm or more and 3 μm or less. When the film thickness of the charge generation layer is within the above range, the charge generation ability is likely to be stable, and the layer can be made to have sufficiently high strength.

(電荷輸送層)
電荷輸送層は、電荷発生層で発生した電荷を輸送可能な層であればよく、例えば電荷輸送物質と、バインダー樹脂とを含む層である。
(Charge transport layer)
The charge transport layer may be any layer as long as it can transport the charge generated in the charge generation layer, and is, for example, a layer containing a charge transport substance and a binder resin.

電荷輸送物質は、電荷を輸送可能な物質であればよく、公知の化合物を使用可能である。電荷輸送物質の例には、カルバゾール誘導体、オキサゾール誘導体、オキサジアゾール誘導体、チアゾール誘導体、チアジアゾール誘導体、トリアゾール誘導体、イミダゾール誘導体、イミダゾロン誘導体、イミダゾリジン誘導体、ビスイミダゾリジン誘導体、スチリル化合物、ヒドラゾン化合物、ピラゾリン化合物、オキサゾロン誘導体、ベンズイミダゾール誘導体、キナゾリン誘導体、ベンゾフラン誘導体、アクリジン誘導体、フェナジン誘導体、アミノスチルベン誘導体、トリアリールアミン誘導体、フェニレンジアミン誘導体、スチルベン誘導体、ベンジジン誘導体、ポリ-N-ビニルカルバゾール、ポリ-1-ビニルピレン及びポリ-9-ビニルアントラセン等が含まれる。電荷輸送層は、これらを1種のみ含んでいてもよく、2種以上含んでいてもよい。 The charge transporting substance may be any substance that can transport charges, and known compounds can be used. Examples of charge-transporting substances include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazol derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline. Compounds, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, aclysine derivatives, phenazine derivatives, aminostilben derivatives, triarylamine derivatives, phenylenediamine derivatives, stillben derivatives, benzidine derivatives, poly-N-vinylcarbazole, poly-1 -Vinylpyrene and poly-9-vinyl anthracene and the like are included. The charge transport layer may contain only one kind of these, or may contain two or more kinds of these.

一方、バインダー樹脂も公知の樹脂を使用可能である。その例には、ポリカーボネート樹脂、ポリアクリレート樹脂、ポリエステル樹脂、ポリスチレン樹脂、スチレン-アクリルニトリル共重合体樹脂、ポリメタクリル酸エステル樹脂、スチレン-メタクリル酸エステル共重合体樹脂等が含まれる。これらの中でもポリカーボネート樹脂が好ましく、特にビスフェノールA(BPA)、ビスフェノールZ(BPZ)、ジメチルBPA、BPA-ジメチルBPA共重合体等の構造を含むポリカーボネート樹脂が耐クラック性、耐摩耗性、帯電性の観点から好ましい。電荷輸送層は、これらを1種のみ含んでいてもよく、2種以上含んでいてもよい。 On the other hand, a known resin can be used as the binder resin. Examples thereof include polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylic nitrile copolymer resin, polymethacrylate resin, styrene-methacrylate copolymer resin and the like. Among these, polycarbonate resin is preferable, and in particular, polycarbonate resin containing structures such as bisphenol A (BPA), bisphenol Z (BPZ), dimethyl BPA, and BPA-dimethyl BPA copolymer has crack resistance, abrasion resistance, and chargeability. Preferred from the point of view. The charge transport layer may contain only one kind of these, or may contain two or more kinds of these.

電荷輸送層は、本発明の目的および効果を損なわない範囲で、酸化防止剤、シリコーンオイル等の各種添加剤を含んでいてもよい。酸化防止剤の具体例には、例えば特開2000-305291号公報に記載されている化合物が含まれる。 The charge transport layer may contain various additives such as an antioxidant and silicone oil as long as the object and effect of the present invention are not impaired. Specific examples of the antioxidant include, for example, the compounds described in JP-A-2000-305291.

電荷輸送層中の電荷輸送物質の量は、バインダー樹脂の量100質量部に対して10質量部以上500質量部以下が好ましく、20質量部以上100質量部以下がより好ましい。電荷輸送物質の量が当該範囲であると、電荷輸送層による電荷輸送性が良好になる。 The amount of the charge-transporting substance in the charge-transporting layer is preferably 10 parts by mass or more and 500 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount of the charge transporting substance is in the above range, the charge transporting property by the charge transporting layer becomes good.

さらに電荷輸送層の厚さは、電荷輸送物質やバインダー樹脂の特性、およびこれらの混合比等により適宜選択されるが、5μm以上40μm以下が好ましく、10μm以上30μm以下がより好ましい。電荷輸送層の膜厚が当該範囲であると、電荷輸送能が安定しやすく、さらに十分に強度の高い層とすることができる。 Further, the thickness of the charge transport layer is appropriately selected depending on the characteristics of the charge transport substance and the binder resin, the mixing ratio thereof, and the like, but is preferably 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less. When the film thickness of the charge transport layer is within the above range, the charge transport capacity is likely to be stable, and the layer can be made to have sufficiently high strength.

(3)表面層
表面層は、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂と、電荷輸送物質と、を含む層であればよく、必要に応じて他の成分を含んでいてもよい。表面層は、上述の感光層を電気的外力および機械的外力から保護するための層として機能する。
(3) Surface layer The surface layer may be a layer containing a thermoplastic resin having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, and a charge transporting substance, as required. It may contain other components. The surface layer functions as a layer for protecting the above-mentioned photosensitive layer from electrical and mechanical external forces.

ここで、熱可塑性樹脂は、表面層中で電荷輸送物質を結着するための物質、すなわち、バインダー樹脂として機能するとともに、電子写真感光体の帯電性を安定化させる物質として機能する。 Here, the thermoplastic resin functions as a substance for binding a charge transporting substance in the surface layer, that is, as a binder resin and also as a substance for stabilizing the chargeability of the electrophotographic photosensitive member.

熱可塑性樹脂は、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である樹脂であればよい。熱可塑性樹脂の電子受容性の有無は、熱可塑性樹脂自体のLUMO準位から直接特定することは困難であるが、HOMO準位が既知である電子供与体と組み合わせたときの電荷移動吸収帯から間接的に見積もることができる。電子供与体のHOMO準位は、市販の光電子分光測定装置(例えば、理研計器社製のAC-3等)により比較的容易に測定できる。電子供与体として、下記化学式で表される構造の化合物CTM-3(4-プロピルビフェニル-ビス(4-メチルフェニル)アミン)(HOMO準位5.6eV)を用いて電子受容性の有無を確認する場合を例に説明する。 The thermoplastic resin may be a resin having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower. It is difficult to directly identify the presence or absence of electron acceptability of a thermoplastic resin from the LUMO level of the thermoplastic resin itself, but from the charge transfer absorption band when combined with an electron donor whose HOMO level is known. It can be estimated indirectly. The HOMO level of the electron donor can be measured relatively easily by a commercially available photoelectron spectroscopy measuring device (for example, AC-3 manufactured by RIKEN KEIKI Co., Ltd.). As an electron donor, the presence or absence of electron acceptability was confirmed using the compound CTM-3 (4-propylbiphenyl-bis (4-methylphenyl) amine) (HOMO level 5.6 eV) having the structure represented by the following chemical formula. This will be described as an example.

まず、対象とする熱可塑性樹脂を表面層から抽出する。抽出方法としては、適切な溶媒に表面層(熱可塑性樹脂)を溶解させる。そして、公知の方法によって、表面層中の成分を分離し、所望の熱可塑性樹脂を分取する。そして、当該熱可塑性樹脂とCTM-3とを、質量比2:1で混合し、これを適切な溶媒に溶解させる。そして、市販の分光光度計(日立ハイテクサイエンス社製のU-3900等)により光吸収スペクトルを測定する。一方、電子供与体のみを溶媒に溶解させたときの光吸収スペクトルも測定する。そして、これらの光吸収スペクトルを比較し、熱可塑性樹脂を混合した系において、370nm以上の波長域に新たな吸収帯が出現した場合、熱可塑性樹脂が、LUMO準位の電荷移動吸収帯が発現した、と判断する。つまり、当該熱可塑性樹脂が電子受容性を有する、とする。なお、上記電荷移動吸収帯が存在していたとしても、CTM-3自体の分子内遷移吸収に埋もれて、電荷移動吸収帯が十分に観測できないケースがある。ただしこのような熱可塑性樹脂では、LUMO準位が2.3eVより小さくなるため、本願では、電子受容性を有さない、と判断する。

Figure 2022033542000001
First, the target thermoplastic resin is extracted from the surface layer. As an extraction method, the surface layer (thermoplastic resin) is dissolved in an appropriate solvent. Then, the components in the surface layer are separated by a known method, and a desired thermoplastic resin is separated. Then, the thermoplastic resin and CTM-3 are mixed at a mass ratio of 2: 1 and dissolved in an appropriate solvent. Then, the light absorption spectrum is measured with a commercially available spectrophotometer (U-3900, etc. manufactured by Hitachi High-Tech Science Corporation). On the other hand, the light absorption spectrum when only the electron donor is dissolved in the solvent is also measured. Then, when these light absorption spectra are compared and a new absorption band appears in the wavelength range of 370 nm or more in the system in which the thermoplastic resin is mixed, the thermoplastic resin expresses the charge transfer absorption band at the LUMO level. Judge that it was done. That is, it is assumed that the thermoplastic resin has electron acceptability. Even if the charge transfer absorption band exists, there are cases where the charge transfer absorption band cannot be sufficiently observed because it is buried in the intramolecular transition absorption of CTM-3 itself. However, since the LUMO level is smaller than 2.3 eV in such a thermoplastic resin, it is judged in the present application that it does not have electron acceptability.
Figure 2022033542000001

また、熱可塑性樹脂の電子受容性の確認には、下記化学式で表される構造を有する化合物CTM-1(ビス(4-(2-(3,4-ジメチルフェニル)-2-フェニルエテニル)-フェニル)-2,4-ジメチルフェニルアミン)(HOMO準位5.4eV)を用いてもよい。当該測定では、430nm以上の波長域に新たな吸収帯が出現する場合に、熱可塑性樹脂が電子受容性を有する、と判断できる。なお、CTM-1との組み合わせで、新たな吸収帯が出願する場合、熱可塑性樹脂のLUMO準位が2.5eVより大きいといえる。したがって、本発明では、CTM-1と組み合わせたときに、新たな吸収帯が出現する熱可塑性樹脂が、より好ましい。

Figure 2022033542000002
To confirm the electron acceptability of the thermoplastic resin, the compound CTM-1 having a structure represented by the following chemical formula (bis (4- (2- (3,4-dimethylphenyl) -2-phenylethenyl)) -Phenyl) -2,4-dimethylphenylamine) (HOMO level 5.4 eV) may be used. In the measurement, it can be determined that the thermoplastic resin has electron acceptability when a new absorption band appears in the wavelength range of 430 nm or more. When a new absorption band is filed in combination with CTM-1, it can be said that the LUMO level of the thermoplastic resin is larger than 2.5 eV. Therefore, in the present invention, a thermoplastic resin in which a new absorption band appears when combined with CTM-1 is more preferable.
Figure 2022033542000002

一方、熱可塑性樹脂のガラス転移温度は、市販の示差走査熱量計(例えば、日立ハイテクサイエンス社製のDSC-7000X等)を用い、10℃/minの昇温条件で測定して得られる値である。ガラス転移温度が225℃以上であると、熱可塑性樹脂の非晶質部分の熱運動が抑制されるため、電子写真感光体使用時の膜削れ量が少なくなり、充分な電子写真感光体寿命を確保できる。一方、熱可塑性樹脂のガラス転移温度が350℃以上の場合、熱可塑性樹脂の分子鎖間の相互作用が強すぎるため、熱可塑性樹脂を溶解可能な溶媒が実質的に存在しない。したがって、熱可塑性樹脂のガラス転移温度は、350℃以下が好ましい。なお、熱可塑性樹脂のガラス転移温度は、250℃以上350℃以下が好ましく、270℃以上320℃以下がより好ましい。 On the other hand, the glass transition temperature of the thermoplastic resin is a value obtained by measuring with a commercially available differential scanning calorimeter (for example, DSC-7000X manufactured by Hitachi High-Tech Science Co., Ltd.) under a temperature rise condition of 10 ° C./min. be. When the glass transition temperature is 225 ° C. or higher, the thermal motion of the amorphous portion of the thermoplastic resin is suppressed, so that the amount of film scraping when using the electrophotographic photosensitive member is reduced, and the life of the electrophotographic photosensitive member is sufficient. Can be secured. On the other hand, when the glass transition temperature of the thermoplastic resin is 350 ° C. or higher, the interaction between the molecular chains of the thermoplastic resin is too strong, so that there is substantially no solvent capable of dissolving the thermoplastic resin. Therefore, the glass transition temperature of the thermoplastic resin is preferably 350 ° C. or lower. The glass transition temperature of the thermoplastic resin is preferably 250 ° C. or higher and 350 ° C. or lower, more preferably 270 ° C. or higher and 320 ° C. or lower.

上記のように、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂の例には、ポリイミド樹脂、ポリイミドアミド樹脂、ポリエーテルイミド樹脂、ポリエーテルエーテルケトン樹脂、ポリスルホン樹脂、ポリエーテルスルホン樹脂、ポリエーテルサルファイド樹脂、ポリカーボネート樹脂、ポリアリレート樹脂等が含まれる。これらの中でもポリイミド樹脂が耐摩耗性の観点から好ましい。また、これらの熱可塑性樹脂が、ハロゲン原子(フッ素、塩素、臭素、ヨウ素)、シアノ基、ニトロ基、アセチル基、ホルミル基等の電子吸引基を有する場合、熱可塑性樹脂の電子受容性がさらに高まるため好ましい。なお、表面層は、上記熱可塑性樹脂を、1種のみ含んでもよく、2種以上含んでもよい。 As described above, examples of thermoplastic resins having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower include polyimide resins, polyimide amide resins, polyetherimide resins, and polyether ether ketone resins. , Polysulfone resin, polyether sulfone resin, polyether sulfide resin, polycarbonate resin, polyarylate resin and the like are included. Among these, polyimide resin is preferable from the viewpoint of wear resistance. Further, when these thermoplastic resins have electron-withdrawing groups such as halogen atoms (fluorine, chlorine, bromine, iodine), cyano groups, nitro groups, acetyl groups, and formyl groups, the electron acceptability of the thermoplastic resins is further increased. It is preferable because it increases. The surface layer may contain only one type of the above-mentioned thermoplastic resin, or may contain two or more types of the thermoplastic resin.

上記熱可塑性樹脂は、特に溶媒に可溶なポリイミド樹脂(以下、「溶媒可溶性ポリイミド樹脂」とも称する)が好ましい。溶媒に可溶とは、対象となるポリイミド樹脂10gを、25℃において、適切な有機溶媒100gに溶解させたとき、当該溶液の可視光領域における全光線透過率が80%以上となり、かつ当該有機溶媒中で、100nm以上の粒子が形成されないこと、をいう。 The thermoplastic resin is particularly preferably a solvent-soluble polyimide resin (hereinafter, also referred to as “solvent-soluble polyimide resin”). Soluble in solvent means that when 10 g of the target polyimide resin is dissolved in 100 g of an appropriate organic solvent at 25 ° C., the total light transmittance of the solution in the visible light region becomes 80% or more, and the organic substance is used. It means that particles having a diameter of 100 nm or more are not formed in a solvent.

上記熱可塑性樹脂として使用可能な、溶媒可溶性ポリイミド樹脂は市販品であってもよく、その具体例には、Sixef-44(Hoechst Celanese社製)、KPI-MX300F(河村産業株式会社製)、PI-100(丸善石油化学株式会社製)、Q-AD-X1390(株式会社ピーアイ技術研究所製)等が含まれる。 The solvent-soluble polyimide resin that can be used as the thermoplastic resin may be a commercially available product, and specific examples thereof include Sixef-44 (manufactured by Hoechst Celanese), KPI-MX300F (manufactured by Kawamura Sangyo Co., Ltd.), and PI. -100 (manufactured by Maruzen Petrochemical Co., Ltd.), Q-AD-X1390 (manufactured by PI Technology Research Institute Co., Ltd.) and the like are included.

表面層は、上記熱可塑性樹脂以外に、バインダー樹脂として機能するバインダー樹脂成分をさらに含んでいてもよい。ただし、バインダー樹脂成分の量は、上記熱可塑性樹脂の含有量100質量部に対して25質量部以下が好ましく、10質量部以下がより好ましい。バインダー樹脂成分の種類は特に制限されず、上記熱可塑性樹脂と相溶性を有する、公知の熱可塑性樹脂が含まれる。その例には、ポリカーボネート、ポリアリレート等が含まれる。 In addition to the above-mentioned thermoplastic resin, the surface layer may further contain a binder resin component that functions as a binder resin. However, the amount of the binder resin component is preferably 25 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the thermoplastic resin content. The type of the binder resin component is not particularly limited, and a known thermoplastic resin having compatibility with the above-mentioned thermoplastic resin is included. Examples include polycarbonate, polyarylate and the like.

一方、電荷輸送物質は、電荷輸送性を有する物質であればよく、公知の化合物を用いることができる。電荷輸送物質の例には、カルバゾール誘導体、オキサゾール誘導体、オキサジアゾール誘導体、チアゾール誘導体、チアジアゾール誘導体、トリアゾール誘導体、イミダゾール誘導体、イミダゾロン誘導体、イミダゾリジン誘導体、ビスイミダゾリジン誘導体、スチリル化合物、ヒドラゾン化合物、ピラゾリン化合物、オキサゾロン誘導体、ベンズイミダゾール誘導体、キナゾリン誘導体、ベンゾフラン誘導体、アクリジン誘導体、フェナジン誘導体、アミノスチルベン誘導体、トリアリールアミン誘導体、フェニレンジアミン誘導体、スチルベン誘導体、ベンジジン誘導体、ポリ-N-ビニルカルバゾール、ポリ-1-ビニルピレンおよびポリ-9-ビニルアントラセン等が含まれる。表面層は、電荷輸送物質を1種のみ含んでいてもよく、2種以上含んでいてもよい。電荷輸送物質は、特にトリアリールアミン誘導体、ベンジジン誘導体が好ましい。 On the other hand, the charge transporting substance may be any substance having a charge transporting property, and a known compound can be used. Examples of charge-transporting substances include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazol derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline. Compounds, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, aclysine derivatives, phenazine derivatives, aminostilben derivatives, triarylamine derivatives, phenylenediamine derivatives, stillben derivatives, benzidine derivatives, poly-N-vinylcarbazole, poly-1 -Vinylpyrene and poly-9-vinyl anthracene and the like are included. The surface layer may contain only one type of charge transporting substance, or may contain two or more types. As the charge transporting substance, a triarylamine derivative and a benzidine derivative are particularly preferable.

表面層中の電荷輸送物質の量は、上記熱可塑性樹脂100質量部に対して10質量部以上500質量部以下が好ましく、20質量部以上100質量部以下がより好ましい。電荷輸送物質の量が当該範囲であると、表面層の電荷輸送性が良好になり、画像メモリー等が生じ難くなる。 The amount of the charge transporting substance in the surface layer is preferably 10 parts by mass or more and 500 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. When the amount of the charge transporting substance is within the range, the charge transporting property of the surface layer becomes good, and an image memory or the like is less likely to occur.

表面層は、上記熱可塑性樹脂および電荷輸送物質以外に、無機粒子および/または有機粒子を含んでいてもよい。 The surface layer may contain inorganic particles and / or organic particles in addition to the above-mentioned thermoplastic resin and charge transporting substance.

無機粒子の例には、シリカ粒子、酸化スズ粒子、酸化アルミニウム粒子、酸化チタン粒子、チタン酸カルシウム粒子等が含まれる。また、有機粒子の例には、スチレン-アクリル粒子、メラミン粒子、ポリフルオロエチレン粒子、シリコーン粒子等が含まれる。これらの中でも、シリカ粒子、酸化スズ粒子、スチレン-アクリル粒子が好ましい。また、無機粒子および有機粒子の平均一次粒径は10nm以上1000nm以下が、表面層の表面粗さを調整する観点で好ましい。当該平均一次粒径は、電子顕微鏡画像から直接測定した一次粒径の100個平均値として定義されるものである。 Examples of the inorganic particles include silica particles, tin oxide particles, aluminum oxide particles, titanium oxide particles, calcium titanate particles and the like. Examples of organic particles include styrene-acrylic particles, melamine particles, polyfluoroethylene particles, silicone particles and the like. Among these, silica particles, tin oxide particles, and styrene-acrylic particles are preferable. Further, the average primary particle size of the inorganic particles and the organic particles is preferably 10 nm or more and 1000 nm or less from the viewpoint of adjusting the surface roughness of the surface layer. The average primary particle size is defined as a 100-piece average value of the primary particle size measured directly from an electron microscope image.

無機粒子および有機粒子の総量は、表面層の全量に対して1質量%以上50質量%以下が好ましく、2質量%以上20質量%以下がより好ましい。無機粒子および有機粒子の総量が当該範囲であると、表面層の電子受容性や電荷輸送性を阻害し難い。 The total amount of the inorganic particles and the organic particles is preferably 1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 20% by mass or less with respect to the total amount of the surface layer. When the total amount of the inorganic particles and the organic particles is in the above range, it is difficult to inhibit the electron acceptability and charge transport property of the surface layer.

さらに、表面層は、本発明の目的および効果を損なわない範囲で、酸化防止剤やシリコーンオイル等の各種添加剤を含んでいてもよい。酸化防止剤の例には、特開2000-305291号公報に記載されている化合物等が含まれる。 Further, the surface layer may contain various additives such as an antioxidant and silicone oil as long as the object and effect of the present invention are not impaired. Examples of the antioxidant include the compounds described in JP-A-2000-305291.

また、表面層の厚さは、熱可塑性樹脂や電荷輸送物質の特性、およびこれらの混合比等によって適宜選択されるが、通常1μm以上30μm以下が好ましく、3μm以上20μm以下がより好ましい。表面層の厚さが当該範囲であると、表面層によって感光層を十分に保護できる。 The thickness of the surface layer is appropriately selected depending on the characteristics of the thermoplastic resin and the charge transporting substance, the mixing ratio thereof, and the like, but is usually preferably 1 μm or more and 30 μm or less, and more preferably 3 μm or more and 20 μm or less. When the thickness of the surface layer is within the range, the surface layer can sufficiently protect the photosensitive layer.

また、表面層の体積抵抗率は1×1012Ωcm以上が好ましく、1×1013Ωcm以上がより好ましく、1×1014Ωcm以上がさらに好ましい。表面層の体積抵抗率が1×1012Ωcm以上であると、電子写真感光体表面が十分に絶縁性を有し、良好な帯電性が得られる。体積抵抗率は、市販の装置(例えば、ダイヤインスツルメンツ社製のハイレスタ-UP(MCP-450))を用い、温度20℃、相対湿度50%の環境下、印加電圧100V(1分間)で測定して求められる。 The volume resistivity of the surface layer is preferably 1 × 10 12 Ωcm or more, more preferably 1 × 10 13 Ωcm or more, and even more preferably 1 × 10 14 Ωcm or more. When the volume resistivity of the surface layer is 1 × 10 12 Ωcm or more, the surface of the electrophotographic photosensitive member has sufficient insulating properties and good chargeability can be obtained. The volume resistivity is measured at an applied voltage of 100 V (1 minute) in an environment of a temperature of 20 ° C. and a relative humidity of 50% using a commercially available device (for example, High Restor UP (MCP-450) manufactured by Dia Instruments). Is required.

(3)その他の層
上述のように、本発明の電子写真感光体は、導電性支持体と感光層との間に、必要に応じて、他の層を含んでいてもよく、例えば以下の中間層を含んでいてもよい。
(3) Other Layers As described above, the electrophotographic photosensitive member of the present invention may contain another layer between the conductive support and the photosensitive layer, if necessary, for example, the following. It may include an intermediate layer.

中間層は、電荷発生層で発生した電子を導電性支持体側に移動させるための層である。中間層は、例えば、導電性微粒子およびバインダー樹脂を含む層とすることができる。 The intermediate layer is a layer for moving the electrons generated in the charge generation layer to the conductive support side. The intermediate layer can be, for example, a layer containing conductive fine particles and a binder resin.

導電性微粒子の例には、各種金属粒子;酸化アルミニウム、酸化亜鉛、酸化チタン、酸化スズ、酸化アンチモン、酸化インジウム、酸化ビスマス等の金属酸化物粒子;スズをドープした酸化インジウム;アンチモンをドープした酸化スズ;酸化ジルコニウム等が含まれる。中間層は、導電性微粒子を1種のみ含んでいてもよく、2種以上含んでいてもよい。中間層が2種以上の導電性微粒子を含む場合、これらは固溶体であってもよく、融着していてもよい。導電性微粒子の数平均一次粒径は0.3μm以下が好ましく、0.1μm以下がより好ましい。当該平均一次粒径は、電子顕微鏡画像から直接測定した一次粒径の100個平均値として定義されるものである。 Examples of conductive fine particles include various metal particles; metal oxide particles such as aluminum oxide, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, and bismuth oxide; tin-doped indium oxide; antimony-doped. Tin oxide; includes zinc oxide and the like. The intermediate layer may contain only one kind of conductive fine particles, or may contain two or more kinds of conductive fine particles. When the intermediate layer contains two or more kinds of conductive fine particles, these may be a solid solution or may be fused. The number average primary particle size of the conductive fine particles is preferably 0.3 μm or less, more preferably 0.1 μm or less. The average primary particle size is defined as a 100-piece average value of the primary particle size measured directly from an electron microscope image.

バインダー樹脂の例には、ポリアミド樹脂、カゼイン、ポリビニルアルコール樹脂、ニトロセルロース、エチレン-アクリル酸共重合体、塩化ビニル樹脂、酢酸ビニル樹脂、ポリウレタン樹脂およびゼラチン等が含まれる。中間層は、バインダー樹脂を1種のみ含んでいてもよく、2種以上含んでいてもよい。中間層は、バインダー樹脂100質量部に対して、導電性微粒子を20質量部以上400質量部以下含むことが好ましく、50質量部以上200質量部以下含むことがより好ましい。導電性微粒子の量が当該範囲であると、十分な導電性を有する層とすることができる。 Examples of the binder resin include polyamide resin, casein, polyvinyl alcohol resin, nitrocellulose, ethylene-acrylic acid copolymer, vinyl chloride resin, vinyl acetate resin, polyurethane resin, gelatin and the like. The intermediate layer may contain only one kind of binder resin, or may contain two or more kinds of binder resin. The intermediate layer preferably contains 20 parts by mass or more and 400 parts by mass or less of the conductive fine particles, and more preferably 50 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount of the conductive fine particles is in the above range, the layer can be made to have sufficient conductivity.

中間層の膜厚は、0.1μm以上15μm以下が好ましく、0.3μm以上10μm以下がより好ましい。中間層の膜厚が当該範囲であると、十分に強度の高い膜とすることができる。 The film thickness of the intermediate layer is preferably 0.1 μm or more and 15 μm or less, and more preferably 0.3 μm or more and 10 μm or less. When the film thickness of the intermediate layer is within the above range, a film having sufficiently high strength can be obtained.

(4)電子写真感光体の層構成
電子写真感光体の層構成は特に制限されず、電子写真感光体に要求される性能や用途等に応じて適宜選択される。例えば、導電性支持体/電荷発生層/電荷輸送層/表面層がこの順に積層されていてもよく、導電性支持体/電荷発生・輸送層/表面層の順に積層されていてもよい。また、導電性支持体/中間層//電荷発生層/電荷輸送層/表面層がこの順に積層されていてもよく、導電性支持体/中間層/電荷発生・輸送層/表面層の順に積層されていてもよい。
(4) Layer structure of electrophotographic photosensitive member The layer structure of the electrophotographic photosensitive member is not particularly limited, and is appropriately selected according to the performance and application required for the electrophotographic photosensitive member. For example, the conductive support / charge generation layer / charge transport layer / surface layer may be laminated in this order, or the conductive support / charge generation / transport layer / surface layer may be laminated in this order. Further, the conductive support / intermediate layer // charge generation layer / charge transport layer / surface layer may be laminated in this order, and the conductive support / intermediate layer / charge generation / transport layer / surface layer may be laminated in this order. It may have been done.

(5)電子写真感光体の製造方法
上述の電子写真感光体は、導電性支持体を準備し、当該導電性支持体上に感光層を形成する工程(感光層形成工程)と、当該感光層上に表面層を形成する工程(表面層形成工程)と、を行うことによって製造できる。なお、感光層を形成する前に導電性支持体上に中間層を形成する工程(中間層形成工程)を行ってもよい。以下、中間層形成工程、感光層形成工程、および表面層形成工程について説明するが、本発明の電子写真感光体の製造方法は、当該方法に限定されない。
(5) Method for Manufacturing Electrophotographic Photoreceptor The above-mentioned electrophotographic photosensitive member includes a step of preparing a conductive support and forming a photosensitive layer on the conductive support (photosensitive layer forming step) and a step of forming the photosensitive layer. It can be manufactured by performing a step of forming a surface layer on the surface (surface layer forming step). A step of forming an intermediate layer on the conductive support (intermediate layer forming step) may be performed before forming the photosensitive layer. Hereinafter, the intermediate layer forming step, the photosensitive layer forming step, and the surface layer forming step will be described, but the method for producing the electrophotographic photosensitive member of the present invention is not limited to this method.

(中間層形成工程)
中間層形成工程では、上述の導電性支持体を準備し、当該導電性支持体上に上述の中間層を形成する。上記中間層は、上述の導電性微粒子、上述のバインダー樹脂、および溶媒を含む中間層組成物を塗布し、固化させることで形成できる。
(Intermediate layer forming process)
In the intermediate layer forming step, the above-mentioned conductive support is prepared, and the above-mentioned intermediate layer is formed on the above-mentioned conductive support. The intermediate layer can be formed by applying and solidifying an intermediate layer composition containing the above-mentioned conductive fine particles, the above-mentioned binder resin, and a solvent.

中間層組成物が含む溶媒の例には、メタノール、エタノール、n-プロピルアルコール、イソプロピルアルコール、n-ブタノール、t-ブタノール、sec-ブタノール等の炭素数1以上4以下のアルコール類が中間層組成物の塗布性等の観点で好ましい。また、中間層組成物の保存性や導電性微粒子の分散性向上等の観点で、中間層組成物は、ベンジルアルコール、トルエン、シクロヘキサノン、テトラヒドロフラン等をさらに含んでいてもよい。 Examples of the solvent contained in the intermediate layer composition include alcohols having 1 or more and 4 or less carbon atoms such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, and sec-butanol. It is preferable from the viewpoint of the applicability of the substance. Further, from the viewpoint of improving the storage stability of the intermediate layer composition and improving the dispersibility of the conductive fine particles, the intermediate layer composition may further contain benzyl alcohol, toluene, cyclohexanone, tetrahydrofuran and the like.

中間層組成物の調製方法は特に制限されない。例えば溶媒およびバインダー樹脂を先に混合し、後から導電性微粒子を添加してもよい。導電性微粒子の分散は、超音波分散機、ボールミル、サンドグラインダー、ホモミキサー等によって行うことができる。 The method for preparing the intermediate layer composition is not particularly limited. For example, the solvent and the binder resin may be mixed first, and then the conductive fine particles may be added. Dispersion of the conductive fine particles can be performed by an ultrasonic disperser, a ball mill, a sand grinder, a homomixer or the like.

また、中間層組成物の塗布方法は特に制限されず、浸漬コーティング法、スプレーコーティング法、スピンナーコーティング法、ビードコーティング法、ブレードコーティング法、ビームコーティング法、円形量規制型塗布法等であってもよい。さらに、中間層組成物の乾燥方法は、溶媒の種類や形成する膜厚に応じて公知の乾燥方法を適宜選択でき、特に熱乾燥が好ましい。 Further, the coating method of the intermediate layer composition is not particularly limited, and may be a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a circular amount-regulated coating method, or the like. good. Further, as the drying method of the intermediate layer composition, a known drying method can be appropriately selected depending on the type of solvent and the film thickness to be formed, and heat drying is particularly preferable.

(感光層形成工程)
感光層形成工程では、導電性支持体上、または上記中間層上に、感光層を形成する。感光層の形成方法は、感光層の層構成に応じて適宜選択される。例えば、感光層が電荷発生・輸送層の一層のみからなる場合には、電荷発生物質、電荷輸送物質、バインダー樹脂、および溶媒等を含む電荷発生・輸送層組成物を調製し、これを中間層上に塗布・固化させて感光層を形成する。一方で、感光層が、電荷発生層および電荷輸送層の2層からなる場合には、以下のような方法で、各層を順に形成する。
(Photosensitive layer forming process)
In the photosensitive layer forming step, the photosensitive layer is formed on the conductive support or on the intermediate layer. The method for forming the photosensitive layer is appropriately selected according to the layer structure of the photosensitive layer. For example, when the photosensitive layer is composed of only one layer of the charge generating / transporting layer, a charge generating / transporting layer composition containing a charge generating substance, a charge transporting substance, a binder resin, a solvent and the like is prepared, and this is used as an intermediate layer. A photosensitive layer is formed by applying and solidifying on top. On the other hand, when the photosensitive layer is composed of two layers, a charge generation layer and a charge transport layer, each layer is formed in order by the following method.

・電荷発生層の形成
電荷発生層の形成方法は特に制限されず、上述の電荷発生物質、上述のバインダー樹脂、および溶媒を含む電荷発生層組成物を上述の導電性支持体上(中間層形成工程を行う場合には中間層上)に塗布し、固化させることで形成できる。
-Formation of the charge generating layer The method of forming the charge generating layer is not particularly limited, and the charge generating layer composition containing the above-mentioned charge generating substance, the above-mentioned binder resin, and the solvent is placed on the above-mentioned conductive support (intermediate layer formation). When performing the process, it can be formed by applying it on the intermediate layer) and solidifying it.

電荷発生層組成物に使用する溶媒の例には、トルエン、キシレン、メチルエチルケトン、シクロヘキサン、酢酸エチル、酢酸ブチル、メタノール、エタノール、プロパノール、ブタノール、メチルセロソルブ、エチルセロソルブ、テトラヒドロフラン、1-ジオキサン、1,3-ジオキソラン、ピリジンおよびジエチルアミン等が含まれる。電荷発生層組成物は、これらを1種のみ含んでもよく、2種以上含んでもよい。 Examples of solvents used in the charge generation layer composition include toluene, xylene, methyl ethyl ketone, cyclohexane, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1-dioxane, 1, 3-Dioxolane, pyridine, diethylamine and the like are included. The charge generation layer composition may contain only one kind of these, or may contain two or more kinds of these.

電荷発生層組成物の調製方法は、電荷発生物質、バインダー樹脂、および溶媒を十分に混合可能な方法であればよい。例えば、バインダー樹脂と溶媒とを混合し、その後、電荷発生物質を加えてもよい。電荷発生層組成物の調製の際には、超音波分散機、ボールミル、サンドグラインダー、ホモミキサー等の分散装置を使用可能である。 The method for preparing the charge generating layer composition may be any method as long as the charge generating substance, the binder resin, and the solvent can be sufficiently mixed. For example, the binder resin and the solvent may be mixed, and then a charge generating substance may be added. When preparing the charge generation layer composition, a disperser such as an ultrasonic disperser, a ball mill, a sand grinder, or a homomixer can be used.

電荷発生層組成物の塗布方法は特に制限されず、公知の方法とすることができる。その例には、浸漬コーティング法、スプレーコーティング法、スピンナーコーティング法、ビードコーティング法、ブレードコーティング法、ビームコーティング法、円形量規制型塗布法等が含まれる。また、電荷発生層組成物の固化方法は特に制限されず、加熱等によって溶媒を除去して固化させてもよく、自然乾燥等によって固化させてもよい。 The method for applying the charge generating layer composition is not particularly limited, and a known method can be used. Examples include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a circular amount regulation type coating method and the like. Further, the method for solidifying the charge generating layer composition is not particularly limited, and the solvent may be removed and solidified by heating or the like, or may be solidified by natural drying or the like.

・電荷輸送層の形成
上記電荷輸送層の形成方法も特に制限されず、上述の電荷輸送物質、上述のバインダー樹脂、および溶媒を含む電荷輸送層組成物を塗布し、固化させることで、形成できる。
-Formation of the charge transport layer The method for forming the charge transport layer is also not particularly limited, and can be formed by applying and solidifying a charge transport layer composition containing the above charge transport substance, the above binder resin, and a solvent. ..

溶媒の例には、トルエン、キシレン、メチルエチルケトン、シクロヘキサノン、酢酸エチル、酢酸ブチル、メタノール、エタノール、プロパノール、ブタノール、テトラヒドロフラン、1,4-ジオキサン、1,3-ジオキソラン等が含まれる。電荷輸送層組成物は、これらを1種のみ含んでいてもよく、2種以上含んでいてもよい。 Examples of solvents include toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane and the like. The charge transport layer composition may contain only one kind of these, or may contain two or more kinds of these.

電荷輸送物質、バインダー樹脂、および溶媒の混合方法は特に制限されない。公知の撹拌装置等によって混合できる。さらに、電荷輸送層組成物の塗布方法は特に制限されず、公知の方法とすることができる。その例には、浸漬コーティング法、スプレーコーティング法、スピンナーコーティング法、ビードコーティング法、ブレードコーティング法、ビームコーティング法、円形量規制型塗布法等が含まれる。また、電荷輸送層組成物の固化方法は特に制限されず、例えば加熱等によって溶媒を除去して固化させてもよく、自然乾燥等によって固化させてもよい。 The method of mixing the charge transporting substance, the binder resin, and the solvent is not particularly limited. It can be mixed by a known stirring device or the like. Further, the method for applying the charge transport layer composition is not particularly limited, and a known method can be used. Examples include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a circular amount regulation type coating method and the like. Further, the method for solidifying the charge transport layer composition is not particularly limited, and for example, the solvent may be removed and solidified by heating or the like, or may be solidified by natural drying or the like.

(表面層形成工程)
表面層形成工程では、上述の感光層上に表面層を形成する。表面層の形成方法は特に制限されず、例えば上述の熱可塑性樹脂、上述の電荷輸送物質、および溶媒、ならびに必要に応じて他の成分を含む表面層組成物を公知の方法で、上記感光層上に塗布し、固化させることで形成できる。
(Surface layer forming process)
In the surface layer forming step, a surface layer is formed on the above-mentioned photosensitive layer. The method for forming the surface layer is not particularly limited, and for example, a surface layer composition containing the above-mentioned thermoplastic resin, the above-mentioned charge transporting substance, and a solvent, and if necessary, other components is prepared by a known method for the above-mentioned photosensitive layer. It can be formed by applying it on top and solidifying it.

上記表面層組成物が含む溶媒、すなわち熱可塑性樹脂および電荷輸送物質を溶解もしくは分散可能な溶媒の例には、トルエン、キシレン、メチルエチルケトン、シクロヘキサノン、酢酸エチル、酢酸ブチル、メタノール、エタノール、プロパノール、ブタノール、テトラヒドロフラン、1,4-ジオキサン、1,3-ジオキソラン、ジクロロメタン、N,N-ジメチルホルムアミド、N,N-ジメチルアセトアミド、N-メチル-2-ピロリドン等が含まれる。表面層組成物は、これらを1種のみ含んでいてもよく、2種以上含んでいてもよい。 Examples of the solvent contained in the surface layer composition, that is, the solvent capable of dissolving or dispersing the thermoplastic resin and the charge transporting substance, include toluene, xylene, methylethylketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol and butanol. , Tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, dichloromethane, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like. The surface layer composition may contain only one of these, or may contain two or more of them.

上記の中でも、沸点が40℃以上150℃以下である溶媒が好ましく、60℃以上120℃以下である溶媒がより好ましい。溶媒の沸点が150℃以下であると、乾燥後の表面層に残留溶媒が少なくなりやすい。一方、溶媒の沸点が40℃以上であると、表面層組成物の保存時や塗布時に溶媒が揮発し難く、表面層組成物の取扱性が良好になる。なお、溶媒を二種以上含む場合には、各成分溶媒の沸点が上記範囲にあることが好ましい。 Among the above, a solvent having a boiling point of 40 ° C. or higher and 150 ° C. or lower is preferable, and a solvent having a boiling point of 60 ° C. or higher and 120 ° C. or lower is more preferable. When the boiling point of the solvent is 150 ° C. or lower, the residual solvent tends to be reduced in the surface layer after drying. On the other hand, when the boiling point of the solvent is 40 ° C. or higher, the solvent is less likely to volatilize during storage or coating of the surface layer composition, and the handleability of the surface layer composition is improved. When two or more kinds of solvents are contained, it is preferable that the boiling point of each component solvent is in the above range.

熱可塑性樹脂、電荷輸送物質、溶媒等の混合方法は特に制限されない。公知の撹拌装置等によって混合できる。また、表面層組成物の塗布方法は特に制限されず、公知の方法とすることができる。その例には、浸漬コーティング法、スプレーコーティング法、スピンナーコーティング法、ビードコーティング法、ブレードコーティング法、ビームコーティング法、円形量規制型塗布法等が含まれる。さらに、表面層組成物の固化方法は特に制限されず、例えば加熱等によって溶媒を除去して固化させてもよく、自然乾燥等によって固化させてもよい。溶媒を除去する際の温度は、50℃以上140℃以下が好ましく、80℃以上130℃以下がより好ましい。上述のように、溶媒可溶性ポリイミド樹脂を熱可塑性樹脂として用いた場合には、表面層組成物を高温に加熱しなくても、ポリイミド樹脂を含む表面層を形成できる。さらに、未反応の官能基が表面層内に残存し難い、という利点もある。 The mixing method of the thermoplastic resin, the charge transporting substance, the solvent and the like is not particularly limited. It can be mixed by a known stirring device or the like. Further, the method for applying the surface layer composition is not particularly limited, and a known method can be used. Examples include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a circular amount regulation type coating method and the like. Further, the method for solidifying the surface layer composition is not particularly limited, and for example, the solvent may be removed and solidified by heating or the like, or may be solidified by natural drying or the like. The temperature at which the solvent is removed is preferably 50 ° C. or higher and 140 ° C. or lower, and more preferably 80 ° C. or higher and 130 ° C. or lower. As described above, when the solvent-soluble polyimide resin is used as the thermoplastic resin, the surface layer containing the polyimide resin can be formed without heating the surface layer composition to a high temperature. Further, there is an advantage that unreacted functional groups are unlikely to remain in the surface layer.

2.画像形成装置
本発明の画像形成装置は、上述の電子写真感光体、および当該電子写真感光体を帯電するための接触帯電部材を有していればよく、その他の構成は、一般的な画像形成装置と同様とすることができる。当該画像形成装置の一例について、以下説明する。
2. 2. Image forming apparatus The image forming apparatus of the present invention may have the above-mentioned electrophotographic photosensitive member and a contact charging member for charging the electrophotographic photosensitive member, and other configurations are general image forming. It can be similar to the device. An example of the image forming apparatus will be described below.

図1に示す画像形成装置100は、画像読取部110、画像処理部30、画像形成部40、用紙搬送部50および定着装置60を有する。 The image forming apparatus 100 shown in FIG. 1 includes an image reading unit 110, an image processing unit 30, an image forming unit 40, a paper transport unit 50, and a fixing device 60.

画像形成部40は、Y(イエロー)、M(マゼンタ)、C(シアン)、K(ブラック)の各色トナーによる画像を形成する画像形成ユニット41Y、41M、41Cおよび41Kを有する。これらは、収容されるトナー以外はいずれも同じ構成を有するので、以後、色を表す記号を省略することがある。画像形成部40は、さらに、中間転写ユニット42および二次転写ユニット43を有する。 The image forming unit 40 has image forming units 41Y, 41M, 41C and 41K for forming an image with each color toner of Y (yellow), M (magenta), C (cyan) and K (black). Since these have the same configuration except for the toner to be accommodated, the symbol indicating the color may be omitted hereafter. The image forming unit 40 further has an intermediate transfer unit 42 and a secondary transfer unit 43.

画像形成ユニット41は、露光装置411、現像装置412、電子写真感光体413、帯電装置414、およびドラムクリーニング装置415を有する。電子写真感光体413は、上述の電子写真感光体である。帯電装置414は、帯電ローラーや帯電ブラシ、帯電ブレードなどの接触帯電部材を電子写真感光体413に接触させて帯電させる接触帯電装置である。帯電装置414として、非接触型のコロナ放電装置を用いることもできる。露光装置411は、例えば、光源としての半導体レーザーと、形成すべき画像に応じたレーザーを電子写真感光体413に向けて照射する光偏向装置(ポリゴンモータ)とを含む。現像装置412は、二成分現像方式の現像装置であり、二成分現像剤を収容している。 The image forming unit 41 includes an exposure device 411, a developing device 412, an electrophotographic photosensitive member 413, a charging device 414, and a drum cleaning device 415. The electrophotographic photosensitive member 413 is the above-mentioned electrophotographic photosensitive member. The charging device 414 is a contact charging device that charges a contact charging member such as a charging roller, a charging brush, or a charging blade by contacting the electrophotographic photosensitive member 413 with the electrophotographic photosensitive member 413. As the charging device 414, a non-contact type corona discharge device can also be used. The exposure apparatus 411 includes, for example, a semiconductor laser as a light source and a light deflector (polygon motor) that irradiates the electrophotographic photosensitive member 413 with a laser corresponding to an image to be formed. The developing device 412 is a developing device of a two-component developing method and contains a two-component developing agent.

中間転写ユニット42は、中間転写体421、中間転写体421を電子写真感光体413に圧接させる一次転写ローラー422、バックアップローラー423Aを含む複数の支持ローラー423、およびベルトクリーニング装置426を有する。 The intermediate transfer unit 42 includes an intermediate transfer body 421, a primary transfer roller 422 that presses the intermediate transfer body 421 against the electrophotographic photosensitive member 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426.

ベルトクリーニング装置426は、中間転写体421に当接する、弾性を有するクリーニングブレード426aを有する。中間転写体421は、複数の支持ローラー423にループ状に張架される。複数の支持ローラー423のうちの少なくとも一つの駆動ローラーが回転することにより、中間転写体421は矢印A方向に一定速度で走行する。 The belt cleaning device 426 has an elastic cleaning blade 426a that abuts on the intermediate transfer body 421. The intermediate transfer body 421 is stretched in a loop on a plurality of support rollers 423. By rotating at least one drive roller among the plurality of support rollers 423, the intermediate transfer body 421 travels at a constant speed in the direction of arrow A.

二次転写ユニット43は、無端状の二次転写ベルト432、および二次転写ローラー431Aを含む複数の支持ローラー431を有する。二次転写ベルト432は、二次転写ローラー431Aおよび支持ローラー431によってループ状に張架される。 The secondary transfer unit 43 has an endless secondary transfer belt 432 and a plurality of support rollers 431 including the secondary transfer roller 431A. The secondary transfer belt 432 is stretched in a loop by the secondary transfer roller 431A and the support roller 431.

定着装置60は、例えば、定着ローラー62と、定着ローラー62の外周面を覆い、用紙S上のトナー画像を構成するトナーを加熱、融解するための無端状の発熱ベルト10と、用紙Sを定着ローラー62および発熱ベルト10に向けて押圧する加圧ローラー63と、を有する。用紙Sは、記録媒体に相当する。 The fixing device 60, for example, covers the fixing roller 62, the outer peripheral surface of the fixing roller 62, and fixes the endless heat generating belt 10 for heating and melting the toner constituting the toner image on the paper S, and the paper S. It has a roller 62 and a pressure roller 63 that presses against the heating belt 10. Paper S corresponds to a recording medium.

画像読取部110は、給紙装置111およびスキャナー112を有する。用紙搬送部50は、給紙部51、排紙部52、および搬送経路部53を有する。給紙部51を構成する三つの給紙トレイユニット51a~51cには、坪量やサイズなどに基づいて識別された用紙S(規格用紙、特殊用紙)が予め設定された種類ごとに収容される。搬送経路部53は、レジストローラー対53aなどの複数の搬送ローラー対を有する。 The image reading unit 110 includes a paper feeding device 111 and a scanner 112. The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, and a transport path unit 53. The three paper feed tray units 51a to 51c constituting the paper feed unit 51 accommodate paper S (standard paper, special paper) identified based on the basis weight, size, etc. for each preset type. .. The transport path portion 53 has a plurality of transport roller pairs such as a resist roller pair 53a.

画像形成装置100による画像の形成を説明する。 The formation of an image by the image forming apparatus 100 will be described.

スキャナー112は、コンタクトガラス上の原稿Dを光学的に走査して読み取る。原稿Dからの反射光がCCDセンサ112aにより読み取られ、入力画像データとなる。入力画像データは、画像処理部30において所定の画像処理が施され、露光装置411に送られる。 The scanner 112 optically scans and reads the document D on the contact glass. The reflected light from the document D is read by the CCD sensor 112a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure apparatus 411.

電子写真感光体413は一定の周速度で回転する。帯電装置414は、電子写真感光体413の表面を一様に負極性に帯電させる。露光装置411では、ポリゴンモータのポリゴンミラーが高速で回転し、各色成分の入力画像データに対応するレーザーが、電子写真感光体413の軸方向に沿って展開し、当該軸方向に沿って電子写真感光体413の外周面に照射される。こうして電子写真感光体413の表面には、静電潜像が形成される。 The electrophotographic photosensitive member 413 rotates at a constant peripheral speed. The charging device 414 uniformly charges the surface of the electrophotographic photosensitive member 413 to a negative electrode property. In the exposure apparatus 411, the polygon mirror of the polygon motor rotates at high speed, and the laser corresponding to the input image data of each color component is deployed along the axial direction of the electrophotographic photosensitive member 413, and the electrograph is taken along the axial direction. The outer peripheral surface of the photoconductor 413 is irradiated. In this way, an electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 413.

現像装置412では、上記現像容器内の二成分現像剤の撹拌、搬送によってトナー粒子が帯電し、二成分現像剤は現像ローラーに搬送され、当該現像ローラーの表面で磁性ブラシを形成する。帯電したトナー粒子は、上記磁性ブラシから電子写真感光体413における静電潜像の部分に静電的に付着する。こうして、電子写真感光体413の表面の静電潜像が可視化され、電子写真感光体413の表面に、静電潜像に応じたトナー画像が形成される。なお、「トナー画像」とは、トナーが画像状に集合した状態を言う。 In the developing apparatus 412, the toner particles are charged by stirring and transporting the two-component developer in the developing container, and the two-component developer is transferred to the developing roller to form a magnetic brush on the surface of the developing roller. The charged toner particles electrostatically adhere to the electrostatic latent image portion of the electrophotographic photosensitive member 413 from the magnetic brush. In this way, the electrostatic latent image on the surface of the electrophotographic photosensitive member 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 413. The "toner image" refers to a state in which toner is collected in an image shape.

電子写真感光体413の表面のトナー画像は、電子写真感光体413が回転すると、電子写真感光体413と中間転写体421が当接する一次転写領域に移動する。中間転写体421には図示しない電源により負極性の電圧が印加され、所定の表面電位に帯電する。また、この印加電圧によって発生した電界でトナーが移動することで、電子写真感光体413の表面のトナー像が中間転写体421の表面に一次転写される。一次転写後、電子写真感光体413に残存する液体現像剤はベルトクリーニング装置426により除去され、帯電装置414によって電子写真感光体413の表面は再び所定の表面電位に一様に帯電する。 The toner image on the surface of the electrophotographic photosensitive member 413 moves to the primary transfer region where the electrophotographic photosensitive member 413 and the intermediate transfer body 421 come into contact with each other when the electrophotographic photosensitive member 413 rotates. A negative voltage is applied to the intermediate transfer body 421 by a power source (not shown), and the intermediate transfer body 421 is charged to a predetermined surface potential. Further, when the toner moves by the electric field generated by this applied voltage, the toner image on the surface of the electrophotographic photosensitive member 413 is primaryly transferred to the surface of the intermediate transfer body 421. After the primary transfer, the liquid developer remaining on the electrophotographic photosensitive member 413 is removed by the belt cleaning device 426, and the surface of the electrophotographic photosensitive member 413 is uniformly charged to a predetermined surface potential again by the charging device 414.

一次転写ローラー422によって中間転写体421が電子写真感光体413に圧接することにより、電子写真感光体413と中間転写体421とによって、一次転写ニップが電子写真感光体ごとに形成される。当該一次転写ニップにおいて、各色のトナー画像が中間転写体421に順次重なって転写される。 When the intermediate transfer body 421 is pressed against the electrophotographic photosensitive member 413 by the primary transfer roller 422, the primary transfer nip is formed for each electrophotographic photosensitive member by the electrophotographic photosensitive member 413 and the intermediate transfer body 421. At the primary transfer nip, the toner images of each color are sequentially superimposed on the intermediate transfer body 421 and transferred.

一方、二次転写ローラー431Aは、中間転写体421および二次転写ベルト432を介して、バックアップローラー423Aに圧接される。それにより、中間転写体421と二次転写ベルト432とによって、二次転写ニップが形成される。当該二次転写ニップを用紙Sが通過する。用紙Sは、用紙搬送部50によって二次転写ニップへ搬送される。用紙Sの傾きの補正および搬送のタイミングの調整は、レジストローラー対53aが配設されたレジストローラー部により行われる。 On the other hand, the secondary transfer roller 431A is pressed against the backup roller 423A via the intermediate transfer body 421 and the secondary transfer belt 432. As a result, the secondary transfer nip is formed by the intermediate transfer body 421 and the secondary transfer belt 432. Paper S passes through the secondary transfer nip. The paper S is transported to the secondary transfer nip by the paper transport unit 50. The correction of the inclination of the paper S and the adjustment of the transfer timing are performed by the resist roller portion in which the resist roller pair 53a is arranged.

上記二次転写ニップに用紙Sが搬送されると、二次転写ローラー431Aへ転写バイアスが印加される。この転写バイアスの印加によって、中間転写体421に担持されているトナー画像が用紙Sに転写される。トナー画像が転写された用紙Sは、二次転写ベルト432によって、定着装置60に向けて搬送される。 When the paper S is conveyed to the secondary transfer nip, a transfer bias is applied to the secondary transfer roller 431A. By applying this transfer bias, the toner image supported on the intermediate transfer body 421 is transferred to the paper S. The paper S on which the toner image is transferred is conveyed toward the fixing device 60 by the secondary transfer belt 432.

中間転写体421の表面に形成されたフルカラーのトナー像は、中間転写体421が矢印方向に回転することで、中間転写体421と用紙Sが当接する二次転写領域に移動する。二次転写領域では、用紙Sの裏面にある二次転写ローラー431Aによって中間転写体421と用紙Sとの間に線圧が加えられながら、二次転写ローラー431Aには図示しない電源によって負極性の電圧が印加される。また、このとき中間転写体421の表面も所定の表面電位に帯電させられる。この電圧印加により、用紙Sの中間転写体421と向き合う表面も負極性の電位となり、用紙Sの表面電位と中間転写体421の表面電位との間の電位差により、トナー像は用紙Sの表面に引き付けられ、この状態で用紙Sが矢印方向に搬送されて二次転写領域を出ると用紙S上へのトナー像の二次転写が完了する。トナー像が転写された用紙Sは定着ローラー62により定着処理がなされ、画像出力が完成する。トナー像が定着された用紙Sは、排紙ローラー52aを備えた排紙部52により機外に排紙される。 The full-color toner image formed on the surface of the intermediate transfer body 421 moves to the secondary transfer region where the intermediate transfer body 421 and the paper S abut by rotating the intermediate transfer body 421 in the direction of the arrow. In the secondary transfer region, while linear pressure is applied between the intermediate transfer body 421 and the paper S by the secondary transfer roller 431A on the back surface of the paper S, the secondary transfer roller 431A has a negative electrode property due to a power supply (not shown). A voltage is applied. Further, at this time, the surface of the intermediate transfer body 421 is also charged to a predetermined surface potential. By applying this voltage, the surface of the paper S facing the intermediate transfer body 421 also becomes a negative potential, and the potential difference between the surface potential of the paper S and the surface potential of the intermediate transfer body 421 causes the toner image to appear on the surface of the paper S. When the paper S is attracted and is conveyed in the direction of the arrow in this state and exits the secondary transfer region, the secondary transfer of the toner image onto the paper S is completed. The paper S on which the toner image is transferred is fixed by the fixing roller 62, and the image output is completed. The paper S on which the toner image is fixed is discharged to the outside of the machine by the paper ejection unit 52 provided with the paper ejection roller 52a.

以下、本発明の具体的な実施例を比較例とともに説明するが、本発明はこれらに限定されるものではない。なお、実施例中において「部」および「%」は、特に断りのない限り「質量部」および「質量%」を意味する。 Hereinafter, specific examples of the present invention will be described together with comparative examples, but the present invention is not limited thereto. In the examples, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

1.電子写真感光体の作製
〔電子写真感光体1の作製〕
下記のようにして電子写真感光体1を作製した。
1. 1. Fabrication of electrophotographic photosensitive member [Preparation of electrophotographic photosensitive member 1]
The electrophotographic photosensitive member 1 was produced as follows.

<導電性支持体の準備>
直径30mmの円筒形アルミニウム支持体の表面を切削加工し、表面粗さRz=1.5(μm)の導電性支持体を用意した。
<Preparation of conductive support>
The surface of a cylindrical aluminum support having a diameter of 30 mm was machined to prepare a conductive support having a surface roughness Rz = 1.5 (μm).

<中間層の形成>
下記成分を、サンドミルを用いて、バッチ式で10時間分散し、分散液を得た。
(組成)
バインダー樹脂(ポリアミド樹脂CM8000(東レ社製)):1質量部
導電性微粒子(酸化チタンSMT500SAS(テイカ社製)):3質量部
メタノール:10質量部
その後、上記分散液をメタノールにて二倍に希釈し、一夜静置した。静置後の分散液を濾過(フィルター:日本ポール社製リジメッシュ5μmフィルター使用)したものを、中間層組成物とした。当該中間層組成物を、上記導電性支持体上に浸漬塗布法により塗布し、固化させた。中間層の乾燥膜厚は2μmとした。
<Formation of intermediate layer>
The following components were dispersed in a batch system for 10 hours using a sand mill to obtain a dispersion liquid.
(composition)
Binder resin (polyamide resin CM8000 (manufactured by Toray Industries, Inc.)): 1 part by mass Conductive fine particles (titanium oxide SMT500SAS (manufactured by TAYCA)): 3 parts by mass Methanol: 10 parts by mass Then, the above dispersion is doubled with methanol. Diluted and allowed to stand overnight. The dispersion liquid after standing was filtered (filter: using a Rigimesh 5 μm filter manufactured by Nippon Pole Co., Ltd.) to obtain an intermediate layer composition. The intermediate layer composition was applied onto the conductive support by a dip coating method and solidified. The dry film thickness of the intermediate layer was 2 μm.

<感光層の形成>
感光層として、以下の電荷発生層および電荷輸送層を形成した。
<Formation of photosensitive layer>
The following charge generation layer and charge transport layer were formed as the photosensitive layer.

(1)電荷発生層の形成
下記成分を混合し、サンドミルを用いて10時間分散し、電荷発生層組成物を調製した。
(組成)
電荷発生物質(チタニルフタロシアニン顔料(Cu-Kα特性X線回折スペクトル測定で、少なくとも27.3°の位置に最大回折ピークを有するチタニルフタロシアニン顔料)):20質量部
バインダー樹脂(ポリビニルブチラール樹脂(#6000-C:電気化学工業社製)):10質量部
酢酸t-ブチル:700質量部
4-メトキシ-4-メチル-2-ペンタノン:300質量部
上記電荷発生層組成物を上記中間層上に浸漬塗布法で塗布して固化させた。電荷発生層の乾燥膜厚は、0.3μmとした。
(1) Formation of Charge Generation Layer The following components were mixed and dispersed for 10 hours using a sand mill to prepare a charge generation layer composition.
(composition)
Charge generating substance (titanyl phthalocyanine pigment (titanyl phthalocyanine pigment having a maximum diffraction peak at at least 27.3 ° in Cu-Kα characteristic X-ray diffraction spectrum measurement)): 20 parts by mass Binder resin (polyvinyl butyral resin (# 6000) -C: manufactured by Denki Kagaku Kogyo Co., Ltd.)): 10 parts by mass t-butyl acetate: 700 parts by mass 4-methoxy-4-methyl-2-pentanone: 300 parts by mass Immerse the charge generating layer composition on the intermediate layer. It was applied by the coating method and solidified. The dry film thickness of the charge generation layer was 0.3 μm.

(2)電荷輸送層の形成
下記成分を混合し、電荷輸送層組成物を調製した。
(組成)
電荷輸送物質(下記化学式で表される構造を有するCTM-1):150質量部

Figure 2022033542000003
バインダー樹脂(ポリカーボネート(Z-300:三菱ガス化学社製)):300質量部
酸化防止剤(Irganox1010:BASFジャパン社製):6質量部
テトラヒドロフラン:1600質量部
トルエン:400質量部
シリコーンオイル(KF-54:信越化学社製):1質量部
当該電荷輸送層組成物を、上記電荷発生層上に浸漬塗布法で塗布し、固化させた。電荷輸送層の乾燥膜厚は25μmとした。 (2) Formation of Charge Transport Layer The following components were mixed to prepare a charge transport layer composition.
(composition)
Charge transport material (CTM-1 having a structure represented by the following chemical formula): 150 parts by mass
Figure 2022033542000003
Binder resin (Polycarbonate (Z-300: manufactured by Mitsubishi Gas Chemical Company)): 300 parts by mass Antioxidant (Irganox1010: manufactured by BASF Japan): 6 parts by mass tetrahydrofuran: 1600 parts by mass Toluene: 400 parts by mass Silicone oil (KF-) 54: Manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass The charge transport layer composition was applied onto the charge generation layer by a dip coating method and solidified. The dry film thickness of the charge transport layer was 25 μm.

<表面層の形成>
下記成分を混合し、表面層組成物を調製した。
(組成)
電荷輸送物質(上述の化学式で表される化合物CTM-1):150質量部
熱可塑性樹脂(フッ素含有溶媒可溶性ポリイミド樹脂A(Sixef-44:Hoechst Celanese社製)):300質量部
酸化防止剤(Irganox1010:BASFジャパン社製):6質量部
テトラヒドロフラン(沸点66℃):2000質量部
シリコーンオイル(KF-54:信越化学社製):1質量部
上記表面層組成物を、上記電荷発生層上に浸漬塗布法で塗布し、固化させた。表面層の乾燥膜厚は10μmとした。
<Formation of surface layer>
The following components were mixed to prepare a surface layer composition.
(composition)
Charge transport material (Compound CTM-1 represented by the above chemical formula): 150 parts by mass Thermoplastic resin (Fluorine-containing solvent-soluble polyimide resin A (Sixef-44: manufactured by Hoechst Celanese)): 300 parts by mass Antioxidant () Irganox 1010: manufactured by BASF Japan Co., Ltd.): 6 parts by mass tetrahydrofuran (boiling point 66 ° C.): 2000 parts by mass Silicone oil (KF-54: manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass The surface layer composition is placed on the charge generation layer. It was applied by a dip coating method and solidified. The dry film thickness of the surface layer was 10 μm.

なお、上記電荷輸送物質単体、ならびに上記熱可塑性樹脂および上記電荷輸送物質の混合物(質量比2:1)をそれぞれテトラヒドロフランに溶解させ、これらの光吸収スペクトルを分光光度計で測定した。そして、これらの結果を比較したところ、熱可塑性樹脂を含む混合物では、吸収端510nmの吸収帯が観察された。このことから、上記熱可塑性樹脂が、電子受容性を有すると判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により10℃/minの昇温条件で測定したところ、320℃であった。さらに、表面層の体積抵抗率をダイヤインスツルメンツ社製のハイレスタ-UP(MCP-450)を用い、温度20℃、相対湿度50%の環境下、印加電圧100V(1分間)で測定したところ、2×1014Ωcmであった。 The charge-transporting substance alone and the mixture of the thermoplastic resin and the charge-transporting substance (mass ratio 2: 1) were each dissolved in tetrahydrofuran, and their light absorption spectra were measured with a spectrophotometer. When these results were compared, an absorption band having an absorption end of 510 nm was observed in the mixture containing the thermoplastic resin. From this, it can be determined that the thermoplastic resin has electron acceptability. Further, when the glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter under a heating condition of 10 ° C./min, it was 320 ° C. Furthermore, the volume resistivity of the surface layer was measured using a high rester-UP (MCP-450) manufactured by Dia Instruments Co., Ltd. in an environment of a temperature of 20 ° C. and a relative humidity of 50% at an applied voltage of 100 V (1 minute). It was × 10 14 Ωcm.

〔電子写真感光体2の作製〕
表面層組成物に使用する電荷輸送物質を、下記化学式で表される化合物CTM-2に変更したこと以外は、電子写真感光体1と同様に電子写真感光体2を得た。表面層の体積抵抗率を上記と同様に測定したところ、2×1014Ωcmであった。

Figure 2022033542000004
[Preparation of electrophotographic photosensitive member 2]
An electrophotographic photosensitive member 2 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the charge transporting substance used in the surface layer composition was changed to the compound CTM-2 represented by the following chemical formula. When the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 14 Ωcm.
Figure 2022033542000004

〔電子写真感光体3の作製〕
表面層組成物に使用する電荷輸送物質を、下記化学式で表される化合物CTM-3に変更したこと以外は、電子写真感光体1と同様に電子写真感光体3を得た。表面層の体積抵抗率を上記と同様に測定したところ、2×1014Ωcmであった。

Figure 2022033542000005
[Preparation of electrophotographic photosensitive member 3]
An electrophotographic photosensitive member 3 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the charge transporting substance used in the surface layer composition was changed to the compound CTM-3 represented by the following chemical formula. When the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 14 Ωcm.
Figure 2022033542000005

〔電子写真感光体4の作製〕
表面層組成物に平均一次粒径40nmのシリカ粒子(日本アエロジル社製)を60質量部さらに添加したこと以外は、電子写真感光体1と同様に電子写真感光体4を得た。表面層の体積抵抗率を上記と同様に測定したところ、3×1013Ωcmであった。
[Preparation of electrophotographic photosensitive member 4]
An electrophotographic photosensitive member 4 was obtained in the same manner as the electrophotographic photosensitive member 1 except that 60 parts by mass of silica particles (manufactured by Aerosil Japan, Inc.) having an average primary particle size of 40 nm were further added to the surface layer composition. When the volume resistivity of the surface layer was measured in the same manner as above, it was 3 × 10 13 Ωcm.

〔電子写真感光体5の作製〕
表面層組成物に平均一次粒径20nmの酸化スズ粒子(CIKナノテック社製)を60質量部さらに添加したこと以外は、電子写真感光体1と同様に電子写真感光体5を得た。表面層の体積抵抗率を上記と同様に測定したところ、2×1012Ωcmであった。
[Preparation of electrophotographic photosensitive member 5]
An electrophotographic photosensitive member 5 was obtained in the same manner as the electrophotographic photosensitive member 1 except that 60 parts by mass of tin oxide particles (manufactured by CIK Nanotech) having an average primary particle size of 20 nm were further added to the surface layer composition. When the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 12 Ωcm.

〔電子写真感光体6の作製〕
表面層組成物に平均一次粒径100nmの架橋スチレン-アクリル粒子(日本ペイント社製)を30質量部さらに添加したこと以外は、電子写真感光体1と同様に電子写真感光体6を得た。表面層の体積抵抗率を上記と同様に測定したところ、8×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 6]
An electrophotographic photosensitive member 6 was obtained in the same manner as the electrophotographic photosensitive member 1 except that 30 parts by mass of crosslinked styrene-acrylic particles (manufactured by Nippon Paint Co., Ltd.) having an average primary particle size of 100 nm were further added to the surface layer composition. When the volume resistivity of the surface layer was measured in the same manner as above, it was 8 × 10 14 Ωcm.

〔電子写真感光体7の作製〕
表面層組成物の溶媒をテトラヒドロフラン(沸点66℃)1800質量部およびトルエン(沸点111℃)200質量部の混合溶媒に変更したこと以外は、電子写真感光体1と同様に電子写真感光体7を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、2×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 7]
The electrophotographic photosensitive member 7 was similarly used to the electrophotographic photosensitive member 1 except that the solvent of the surface layer composition was changed to a mixed solvent of 1800 parts by mass of tetrahydrofuran (boiling point 66 ° C.) and 200 parts by mass of toluene (boiling point 111 ° C.). Obtained. Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 14 Ωcm.

〔電子写真感光体8の作製〕
表面層組成物の溶媒をテトラヒドロフラン(沸点66℃)1800質量部とo-キシレン(沸点144℃)200質量部の混合溶媒に変更したこと以外は、電子写真感光体1と同様に電子写真感光体8を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、2×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 8]
The electrophotographic photosensitive member is the same as the electrophotographic photosensitive member 1 except that the solvent of the surface layer composition is changed to a mixed solvent of 1800 parts by mass of tetrahydrofuran (boiling point 66 ° C.) and 200 parts by mass of o-xylene (boiling point 144 ° C.). 8 was obtained. Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 14 Ωcm.

〔電子写真感光体9の作製〕
表面層組成物の溶媒をジクロロメタン(沸点40℃)2000質量部に変更したこと以外は、電子写真感光体1と同様に電子写真感光体9を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、3×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 9]
An electrophotographic photosensitive member 9 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the solvent of the surface layer composition was changed to 2000 parts by mass of dichloromethane (boiling point 40 ° C.). Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 3 × 10 14 Ωcm.

〔電子写真感光体10の作製〕
表面層組成物の溶媒をN,N-ジメチルホルムアミド(沸点153℃)2000質量部に変更したこと以外は、電子写真感光体1と同様にして電子写真感光体10を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、1×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 10]
An electrophotographic photosensitive member 10 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the solvent of the surface layer composition was changed to 2000 parts by mass of N, N-dimethylformamide (boiling point 153 ° C.). Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 1 × 10 14 Ωcm.

〔電子写真感光体11の作製〕
表面層組成物の熱可塑性樹脂を溶媒可溶性ポリイミド樹脂B(KPI-MX300F:河村産業社製)300質量部に変更したこと以外は、電子写真感光体1と同様にして電子写真感光体11を得た。なお、上記電荷輸送物質単体、ならびに上記熱可塑性樹脂(溶媒可溶性ポリイミド樹脂B)および上記電荷輸送物質の混合物(質量比2:1)をそれぞれテトラヒドロフランに溶解させ、これらの吸収スペクトルを測定した。そして、これらの結果を比較したところ、熱可塑性樹脂を含む混合物では、吸収端500nmの吸収帯が観察された。このことから、上記熱可塑性樹脂が、電子受容性を有すると判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、297℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、4×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 11]
The electrophotographic photosensitive member 11 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the thermoplastic resin of the surface layer composition was changed to 300 parts by mass of the solvent-soluble polyimide resin B (KPI-MX300F: manufactured by Kawamura Sangyo Co., Ltd.). rice field. The charge transporting substance alone, the thermoplastic resin (solvent-soluble polyimide resin B), and the mixture of the charge transporting substances (mass ratio 2: 1) were each dissolved in tetrahydrofuran, and their absorption spectra were measured. When these results were compared, an absorption band having an absorption end of 500 nm was observed in the mixture containing the thermoplastic resin. From this, it can be determined that the thermoplastic resin has electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 297 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 4 × 10 14 Ωcm.

〔電子写真感光体12の作製〕
表面層組成物に平均一次粒径40nmのシリカ粒子(日本アエロジル社製)を60質量部さらに添加したこと以外は、電子写真感光体1と同様にして電子写真感光体12を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、3×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 12]
An electrophotographic photosensitive member 12 was obtained in the same manner as the electrophotographic photosensitive member 1 except that 60 parts by mass of silica particles (manufactured by Aerosil Japan, Inc.) having an average primary particle size of 40 nm were further added to the surface layer composition. Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 3 × 10 14 Ωcm.

〔電子写真感光体13の作製〕
表面層組成物の熱可塑性樹脂を、溶媒可溶性ポリイミド樹脂C(特開2004-285355号公報の実施例1の記載に従って合成したもの)300質量部に変更し、溶媒をN,N-ジメチルアセトアミド(沸点165℃)に変更したこと以外は、電子写真感光体1と同様に電子写真感光体13を得た。なお、上記電荷輸送物質単体、ならびに上記熱可塑性樹脂(溶媒可溶性ポリイミド樹脂C)および上記電荷輸送物質の混合物(質量比2:1)をそれぞれN,N-ジメチルアセトアミドに溶解させ、これらの吸収スペクトルを測定した。そして、これらの結果を比較したところ、熱可塑性樹脂を含む混合物では、吸収端500nmの吸収帯が観察された。このことから、上記熱可塑性樹脂が、電子受容性を有すると判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、270℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、7×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 13]
The thermoplastic resin of the surface layer composition was changed to 300 parts by mass of a solvent-soluble polyimide resin C (synthesized according to the description of Example 1 of JP-A-2004-285355), and the solvent was changed to N, N-dimethylacetamide (N, N-dimethylacetamide). An electrophotographic photosensitive member 13 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the boiling point was changed to 165 ° C.). The charge transporting substance alone, the thermoplastic resin (solvent-soluble polyimide resin C), and the mixture of the charge transporting substances (mass ratio 2: 1) were dissolved in N and N-dimethylacetamide, respectively, and their absorption spectra were obtained. Was measured. When these results were compared, an absorption band having an absorption end of 500 nm was observed in the mixture containing the thermoplastic resin. From this, it can be determined that the thermoplastic resin has electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 270 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 7 × 10 14 Ωcm.

〔電子写真感光体14の作製〕
表面層組成物の熱可塑性樹脂を溶媒可溶性ポリエーテルスルホン樹脂D(スミカエクセルPES:住友化学社製)2000質量部に変更し、溶媒をN,N-ジメチルホルムアミド(沸点153℃)に変更したこと以外は、電子写真感光体1と同様に電子写真感光体14を得た。上記電荷輸送物質単体、ならびに上記熱可塑性樹脂(溶媒可溶性ポリイミド樹脂D)および上記電荷輸送物質の混合物(質量比2:1)をそれぞれN,N-ジメチルホルムアミドに溶解させ、これらの吸収スペクトルを測定した。そして、これらの結果を比較したところ、熱可塑性樹脂を含む混合物では、吸収端470nmの吸収帯が観察された。このことから、上記熱可塑性樹脂が、電子受容性を有すると判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、225℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、1×1015Ωcmであった。
[Preparation of electrophotographic photosensitive member 14]
The thermoplastic resin of the surface layer composition was changed to 2000 parts by mass of solvent-soluble polyether sulfone resin D (Sumika Excel PES: manufactured by Sumitomo Chemical Co., Ltd.), and the solvent was changed to N, N-dimethylformamide (boiling point 153 ° C.). Except for the above, an electrophotographic photosensitive member 14 was obtained in the same manner as the electrophotographic photosensitive member 1. The charge transporting substance alone, the thermoplastic resin (solvent-soluble polyimide resin D), and the mixture of the charge transporting substances (mass ratio 2: 1) are dissolved in N, N-dimethylformamide, respectively, and their absorption spectra are measured. did. When these results were compared, an absorption band having an absorption end of 470 nm was observed in the mixture containing the thermoplastic resin. From this, it can be determined that the thermoplastic resin has electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 225 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 1 × 10 15 Ωcm.

〔電子写真感光体15の作製〕
電子写真感光体1と同様の方法で電子写真感光体15を作製した。
[Preparation of electrophotographic photosensitive member 15]
The electrophotographic photosensitive member 15 was produced in the same manner as the electrophotographic photosensitive member 1.

〔電子写真感光体16の作製〕
表面層組成物の電荷輸送物質CTM-1を添加せず、表面層の乾燥膜厚を2μmに変更した以外は、電子写真感光体1と同様にして電子写真感光体16を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、4×1016Ωcmであった。
[Preparation of electrophotographic photosensitive member 16]
An electrophotographic photosensitive member 16 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the charge transporting substance CTM-1 of the surface layer composition was not added and the dry film thickness of the surface layer was changed to 2 μm. Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 4 × 10 16 Ωcm.

〔電子写真感光体17の作製〕
表面層組成物の熱可塑性樹脂を溶媒可溶性ポリイミド樹脂E(PI-100:丸善石油化学社製)300質量部に変更し、溶媒をN-メチル-2-ピロリドン(沸点202℃)に変更したこと以外は、電子写真感光体1と同様に電子写真感光体17を得た。上記熱可塑性樹脂(溶媒可溶性ポリイミド樹脂E)と電荷輸送物質(CTM-1)との混合物(質量比2:1)、ならびに上記熱可塑性樹脂(溶媒可溶性ポリイミド樹脂E)および上記電荷輸送物質(CTM-3)の混合物(質量比2:1)をそれぞれN-メチルピロリドンに溶解させ、これらの吸収スペクトルを測定した。また、各電荷輸送物質のみをN-メチルピロリドンに溶解させた溶液についても、吸収スペクトルを測定した。その結果、熱可塑性樹脂を添加した溶液のいずれにおいても、新たな吸収帯が出現せず、上記熱可塑性樹脂は電子受容性を有さないと判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、320℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、1×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 17]
The thermoplastic resin of the surface layer composition was changed to 300 parts by mass of the solvent-soluble polyimide resin E (PI-100: manufactured by Maruzen Petrochemical Co., Ltd.), and the solvent was changed to N-methyl-2-pyrrolidone (boiling point: 202 ° C.). Except for the above, an electrophotographic photosensitive member 17 was obtained in the same manner as the electrophotographic photosensitive member 1. A mixture (mass ratio 2: 1) of the thermoplastic resin (solvent-soluble polyimide resin E) and the charge-transporting substance (CTM-1), and the thermoplastic resin (solvent-soluble polyimide resin E) and the charge-transporting substance (CTM). The mixture of -3) (mass ratio 2: 1) was dissolved in N-methylpyrrolidone, respectively, and their absorption spectra were measured. The absorption spectrum was also measured for a solution in which only each charge transporting substance was dissolved in N-methylpyrrolidone. As a result, no new absorption band appears in any of the solutions to which the thermoplastic resin is added, and it can be determined that the thermoplastic resin does not have electron acceptability. Further, when the glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter, it was 320 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 1 × 10 14 Ωcm.

〔電子写真感光体18の作製〕
表面層組成物の熱可塑性樹脂をポリアミド前駆体のポリアミック酸である樹脂F(パイヤーML:デュポン社製)300質量部に変更し、溶媒をN,N-ジメチルホルムアミド(沸点153℃)1000質量部およびトルエン(沸点111℃)1000質量部の混合溶媒に変更したこと以外は、電子写真感光体1と同様にして電子写真感光体18を得た。上記熱可塑性樹脂(樹脂F)と電荷輸送物質(CTM-1)との混合物(質量比2:1)、ならびに上記熱可塑性樹脂(樹脂F)および上記電荷輸送物質(CTM-3)の混合物(質量比2:1)をそれぞれN-ジメチルホルムアミドに溶解させ、これらの吸収スペクトルを測定した。また、各電荷輸送物質のみをN-ジメチルホルムアミドに溶解させた溶液についても、吸収スペクトルを測定した。その結果、熱可塑性樹脂を添加した溶液のいずれにおいても、新たな吸収帯が出現せず、上記熱可塑性樹脂は電子受容性を有さないと判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、280℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、2×1011Ωcmであった。
[Preparation of electrophotographic photosensitive member 18]
The thermoplastic resin of the surface layer composition was changed to 300 parts by mass of resin F (Pyer ML: manufactured by DuPont) which is a polyamic acid of the polyamide precursor, and the solvent was N, N-dimethylformamide (boiling point 153 ° C.) 1000 parts by mass. An electrophotographic photosensitive member 18 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the solvent was changed to a mixed solvent of 1000 parts by mass of toluene (boiling point: 111 ° C.). A mixture of the thermoplastic resin (resin F) and the charge transporting substance (CTM-1) (mass ratio 2: 1), and a mixture of the thermoplastic resin (resin F) and the charge transporting substance (CTM-3) ( The mass ratio 2: 1) was dissolved in N-dimethylformamide, respectively, and their absorption spectra were measured. The absorption spectrum was also measured for a solution in which only each charge transporting substance was dissolved in N-dimethylformamide. As a result, no new absorption band appears in any of the solutions to which the thermoplastic resin is added, and it can be determined that the thermoplastic resin does not have electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 280 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 11 Ωcm.

〔電子写真感光体19の作製〕
表面層組成物の熱可塑性樹脂を溶媒可溶性ポリイミド樹脂G(Q-AD-X1390:株式会社ピーアイ技術研究所製)300質量部に変更し、溶媒をN-メチル-2-ピロリドン(沸点202℃)に変更したこと以外は、電子写真感光体1と同様にして電子写真感光体19を得た。なお、熱可塑性樹脂(溶媒可溶性ポリイミド樹脂G)は主鎖中にハロゲン原子等の電子吸引基を含有していない。ただし、電荷輸送物質CTM-3単体、ならびに熱可塑性樹脂(溶媒可溶性ポリイミド樹脂G)および電荷輸送物質CTM-3の混合物(質量比2:1)のN-メチル-2-ピロリドン溶液吸収スペクトルをそれぞれ測定したところ、吸収端410nmの吸収帯が新たに出現した。したがって、上記熱可塑性樹脂は電子受容性を有すると判断できる。また、上記熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、150℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、6×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 19]
The thermoplastic resin of the surface layer composition was changed to a solvent-soluble polyimide resin G (Q-AD-X1390: manufactured by PI Technical Research Institute Co., Ltd.) by 300 parts by mass, and the solvent was N-methyl-2-pyrrolidone (boiling point 202 ° C.). An electrophotographic photosensitive member 19 was obtained in the same manner as in the electrophotographic photosensitive member 1 except that the above was changed to. The thermoplastic resin (solvent-soluble polyimide resin G) does not contain an electron-withdrawing group such as a halogen atom in the main chain. However, the absorption spectra of the N-methyl-2-pyrrolidone solution of the charge transport material CTM-3 alone and the mixture of the thermoplastic resin (solvent-soluble polyimide resin G) and the charge transport material CTM-3 (mass ratio 2: 1) are shown. As a result of measurement, a new absorption band with an absorption end of 410 nm appeared. Therefore, it can be determined that the thermoplastic resin has electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 150 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 6 × 10 14 Ωcm.

〔電子写真感光体20の作製〕
表面層組成物の熱可塑性樹脂をポリアリレート樹脂H(M-2000H:ユニチカ社製)300質量部に変更したこと以外は、電子写真感光体1と同様にして電子写真感光体20を得た。なお、熱可塑性樹脂(ポリアリレート樹脂H)と電荷輸送物質(CTM-1)との混合物(質量比2:1)、ならびに上記熱可塑性樹脂(ポリアリレート樹脂H)および上記電荷輸送物質(CTM-3)の混合物(質量比2:1)をテトラヒドロフランに溶解させて吸収スペクトルを測定した。また、各電荷輸送物質のみをN-ジメチルホルムアミドに溶解させた溶液についても、吸収スペクトルを測定した。その結果、熱可塑性樹脂を添加した溶液のいずれにおいても、新たな吸収帯が出現せず、上記熱可塑性樹脂は電子受容性を有さないと判断できる。また、熱可塑性樹脂のガラス転移温度(Tg)を示差走査熱量計により測定したところ、275℃であった。さらに、表面層の体積抵抗率を上記と同様に測定したところ、3×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 20]
An electrophotographic photosensitive member 20 was obtained in the same manner as the electrophotographic photosensitive member 1 except that the thermoplastic resin of the surface layer composition was changed to 300 parts by mass of polyarylate resin H (M-2000H: manufactured by Unitika Ltd.). A mixture (mass ratio 2: 1) of the thermoplastic resin (polyallylate resin H) and the charge transport material (CTM-1), and the thermoplastic resin (polyallylate resin H) and the charge transport material (CTM-). The mixture of 3) (mass ratio 2: 1) was dissolved in tetrahydrofuran and the absorption spectrum was measured. The absorption spectrum was also measured for a solution in which only each charge transporting substance was dissolved in N-dimethylformamide. As a result, no new absorption band appears in any of the solutions to which the thermoplastic resin is added, and it can be determined that the thermoplastic resin does not have electron acceptability. The glass transition temperature (Tg) of the thermoplastic resin was measured by a differential scanning calorimeter and found to be 275 ° C. Further, when the volume resistivity of the surface layer was measured in the same manner as above, it was 3 × 10 14 Ωcm.

〔電子写真感光体21の作製〕
電子写真感光体17と同様の方法で電子写真感光体21を作製した。
[Preparation of electrophotographic photosensitive member 21]
The electrophotographic photosensitive member 21 was produced in the same manner as the electrophotographic photosensitive member 17.

〔電子写真感光体22の作製〕
表面層組成物に、低分子の電子受容性化合物として4-ニトロ-N-フェニルフタルイミド(東京化成)60質量部を添加したこと以外は、電子写真感光体17と同様にして電子写真感光体22を得た。表面層の体積抵抗率を上記と同様に測定したところ、7×1013Ωcmであった。
[Preparation of electrophotographic photosensitive member 22]
The electrophotographic photosensitive member 22 is the same as the electrophotographic photosensitive member 17, except that 60 parts by mass of 4-nitro-N-phenylphthalimide (Tokyo Kasei) is added to the surface layer composition as a small molecule electron-accepting compound. Got When the volume resistivity of the surface layer was measured in the same manner as above, it was 7 × 10 13 Ωcm.

〔電子写真感光体23の作製〕
表面層組成物に低分子の電子受容性化合物として4-ニトロ-N-フェニルフタルイミド(東京化成)60質量部を添加したこと以外は、電子写真感光体20と同様にして電子写真感光体23を得た。また、表面層の体積抵抗率を上記と同様に測定したところ、2×1014Ωcmであった。
[Preparation of electrophotographic photosensitive member 23]
The electrophotographic photosensitive member 23 was prepared in the same manner as the electrophotographic photosensitive member 20 except that 60 parts by mass of 4-nitro-N-phenylphthalimide (Tokyo Kasei) was added to the surface layer composition as a small molecule electron-accepting compound. Obtained. Moreover, when the volume resistivity of the surface layer was measured in the same manner as above, it was 2 × 10 14 Ωcm.

Figure 2022033542000006
Figure 2022033542000006

2.評価
〔電子写真感光体1~23の評価〕
市販のフルカラー複合機で接触帯電方式を採用している「bizhub C658」(コニカミノルタ社製)に電子写真感光体1~14、16~20、22および23を搭載した。また、市販のフルカラー複合機で非接触のコロナ帯電方式を採用している「bizhub C654」(コニカミノルタ社製)に電子写真感光体15および21を搭載した。そして、各電子写真感光体1~23の評価を行った。
2. 2. Evaluation [Evaluation of electrophotographic photosensitive members 1 to 23]
Electrophotographic photoconductors 1 to 14, 16 to 20, 22 and 23 were mounted on a "bizhub C658" (manufactured by Konica Minolta Co., Ltd.), which is a commercially available full-color multifunction device and employs a contact charging method. Further, the electrophotographic photosensitive members 15 and 21 were mounted on "bizhub C654" (manufactured by Konica Minolta Co., Ltd.), which is a commercially available full-color multifunction device and employs a non-contact corona charging method. Then, each electrophotographic photosensitive member 1 to 23 was evaluated.

以下のいずれの試験においても、画像比率5%の文字画像をA4横送りで各20万枚両面連続プリントを行う耐久試験(以下、「長期印刷」ともいう。)を実施した。なお、電子写真感光体19は感光体減耗が激しく10万枚印刷時点で画像が出なくなったので、長期印刷試験後の評価を実施できなかった。 In any of the following tests, a durability test (hereinafter, also referred to as "long-term printing") was carried out in which character images having an image ratio of 5% were continuously printed on both sides of 200,000 sheets in A4 horizontal feed. It should be noted that the electrophotographic photosensitive member 19 could not be evaluated after the long-term printing test because the photoconductor 19 was severely worn and no image was output at the time of printing 100,000 sheets.

(1)耐摩耗性の評価
耐久試験前後における表面層の膜厚を測定し、膜厚減耗量を算出し評価した。表面層の膜厚は均一膜厚部分(塗布の先端部及び後端部の膜厚変動部分を除く)を膜厚測定器によってランダムに10ケ所測定し、その平均値を表面層の膜厚とした。膜厚測定器は、渦電流方式の膜厚測定器「EDDY560C」(HELMUT FISCHER GMBTE CO社製)を用いて行った。そして、耐久試験前後の表面層膜厚の差を膜厚減耗量とした。表2には、100krot(10万回転)あたりの減耗量(μm)を記載した。
(1) Evaluation of wear resistance The film thickness of the surface layer before and after the durability test was measured, and the amount of film thickness wear was calculated and evaluated. As for the film thickness of the surface layer, the uniform film thickness portion (excluding the film thickness fluctuation portion at the front end and the rear end of the coating) is randomly measured at 10 points by a film thickness measuring device, and the average value is taken as the film thickness of the surface layer. did. The film thickness measuring device was used as an eddy current type film thickness measuring device "EDDY560C" (manufactured by HELMUT FISCHER GMBTE CO). Then, the difference in the film thickness of the surface layer before and after the durability test was taken as the amount of film thickness wear. Table 2 shows the amount of wear (μm) per 100 krot (100,000 rpm).

(2)パターンメモリの評価
長期印刷の前後に、温度10℃、湿度15%RHの環境下において、縦方向の帯ベタ画像を、転写材:「A3/PODグロスコート(A3サイズ、100g/m)」(王子製紙社製)上に20枚連続印刷し、続けて全面ベタ画像を3枚印刷した。得られた全面ベタ画像の帯ベタ部の履歴発生、すなわちパターンメモリの発生を、以下の評価基準に従って評価した。濃度計(RD-918;グレタグ・マクベス社製)を用いて、得られた全面ベタ画像のうち帯ベタ履歴部に対応する領域の反射濃度と、帯ベタ履歴部に該当しない領域の反射濃度を測定した。そして、測定された2つの反射濃度差(ΔID)を算出した。結果を表2に示す。
(2) Evaluation of pattern memory Before and after long-term printing, a solid band image in the vertical direction is printed in an environment of temperature 10 ° C. and humidity 15% RH. Transfer material: "A3 / POD gloss coat (A3 size, 100 g / m)" 2 ) ”(manufactured by Oji Paper Co., Ltd.), 20 sheets were continuously printed, and then 3 sheets of solid images were printed on the entire surface. The occurrence of the history of the solid band portion of the obtained solid image, that is, the occurrence of the pattern memory was evaluated according to the following evaluation criteria. Using a densitometer (RD-918; manufactured by Gretag Macbeth), the reflection density of the region corresponding to the solid color band history part and the reflection density of the area not corresponding to the solid color band history part of the obtained full-face solid image are measured. It was measured. Then, the difference between the two measured reflection densities (ΔID) was calculated. The results are shown in Table 2.

(評価基準)
A:全面ベタのΔIDが0.005未満(合格)
B:全面ベタのΔIDが0.005以上0.010未満(合格)
C:全面ベタのΔIDが0.010以上0.030未満(不合格)
D:全面ベタのΔIDが0.030以上(不合格)
(Evaluation criteria)
A: Full solid ΔID is less than 0.005 (pass)
B: Full solid ΔID is 0.005 or more and less than 0.010 (pass)
C: Full solid ΔID is 0.010 or more and less than 0.030 (failure)
D: Full solid ΔID is 0.030 or more (failed)

(3)白地部へのカブリ評価
長期印刷の前後に、温度30℃、湿度80%RHの環境下において、転写材:「A3/PODグロスコート(A3サイズ、100g/m2)」(王子製紙社製)上に、グリッド電圧-900V、現像バイアス-720Vの条件で、無地画像(白ベタ画像)を形成し、ドットアナライザー(DA-7000;王子計測機器製)を用いた黒化率の計測により、白地部へのカブリを評価した。結果を表2に示す。
(3) Evaluation of fog on white background Before and after long-term printing, in an environment of temperature 30 ° C and humidity 80% RH, transfer material: "A3 / POD gloss coat (A3 size, 100 g / m2)" (Oji Paper Co., Ltd.) A plain image (white solid image) is formed on the grid voltage of -900V and development bias of -720V, and the blackening rate is measured using a dot analyzer (DA-7000; manufactured by Oji Measuring Instruments Co., Ltd.). , The fog on the white background was evaluated. The results are shown in Table 2.

(カブリ評価基準)
A:黒化率が0.50%未満(合格)
B:黒化率が0.50%以上1.00%未満(合格)
C:黒化率が1.00%以上5.00%未満(不合格)
D:黒化率が5.00%以上(不合格)

Figure 2022033542000007
(Fog evaluation criteria)
A: Blackening rate is less than 0.50% (pass)
B: Blackening rate is 0.50% or more and less than 1.00% (pass)
C: Blackening rate is 1.00% or more and less than 5.00% (failure)
D: Blackening rate is 5.00% or more (failure)

Figure 2022033542000007

上記表2に示されるように、表面層が、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂と、電荷輸送物質と、を含む電子写真感光体1~15では、いずれもパターンメモリが生じ難く、さらに白地部へのカブリ評価も良好であった。さらに、耐摩耗性も最大で0.41μmであり、非常に優れていた。 As shown in Table 2 above, the electrophotographic photosensitive member 1 contains a thermoplastic resin having an electron accepting property and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, and a charge transporting substance. In all cases of to 15, pattern memory was unlikely to occur, and the fog evaluation on the white background was also good. Further, the wear resistance was 0.41 μm at the maximum, which was very excellent.

一方、表面層が電荷輸送物質を含まない場合には、電荷輸送安定性が低下し、初期からパターンメモリが生じやすかった(電子写真感光体16)。さらに、表面層の熱可塑性樹脂が、電子受容性を有さない場合には、いずれも白地部へのカブリ評価が低かった(電子写真感光体17、18、および20~23)。いずれも、電子写真感光体の帯電安定性が低かったと考えられる。また、上述のように、表面層が含む熱可塑性樹脂のガラス転移温度が225℃未満である電子写真感光体19では、耐久性が非常に低かった。 On the other hand, when the surface layer does not contain the charge transport material, the charge transport stability is lowered and the pattern memory is likely to occur from the initial stage (electrophotographic photosensitive member 16). Furthermore, when the thermoplastic resin in the surface layer did not have electron acceptability, the fog evaluation on the white background was low in all cases (electrophotographic photoconductors 17, 18, and 20 to 23). In all cases, it is probable that the charge stability of the electrophotographic photosensitive member was low. Further, as described above, the electrophotographic photosensitive member 19 having a glass transition temperature of the thermoplastic resin contained in the surface layer of less than 225 ° C. had very low durability.

本発明の電子写真感光体によれば、長期に亘って帯電安定性、耐摩耗性および画像メモリー耐性が優れる。したがって、本発明によれば、電子写真方式の画像形成方法のさらなる普及に寄与することが期待される。 According to the electrophotographic photosensitive member of the present invention, the charge stability, the abrasion resistance and the image memory resistance are excellent for a long period of time. Therefore, according to the present invention, it is expected to contribute to the further spread of the electrophotographic image forming method.

10 発熱ベルト
30 画像処理部
40 画像形成部
41Y、41M、41C、41K 画像形成ユニット
42 中間転写ユニット
43 二次転写ユニット
50 用紙搬送部
51 給紙部
51a、51b、51c 給紙トレイユニット
52 排紙部
52a 排紙ローラー
53 搬送経路部
53a レジストローラー対
60 定着装置
62 定着ローラー
63 加圧ローラー
100 画像形成装置
110 画像読取部
111 給紙装置
112 スキャナー
112a CCDセンサ
411 露光装置
412 現像装置
413 電子写真感光体
414 帯電装置
415 ドラムクリーニング装置
421 中間転写体
422 一次転写ローラー
423 支持ローラー
423A バックアップローラー
426 ベルトクリーニング装置
426a クリーニングブレード
431 支持ローラー
431A 二次転写ローラー
432 二次転写ベルト
D 原稿
S 用紙
10 Heat-generating belt 30 Image processing unit 40 Image forming unit 41Y, 41M, 41C, 41K Image forming unit 42 Intermediate transfer unit 43 Secondary transfer unit 50 Paper transport unit 51 Paper feed unit 51a, 51b, 51c Paper feed tray unit 52 Paper discharge Part 52a Paper ejection roller 53 Conveyance path part 53a Resist roller vs. 60 Fixing device 62 Fixing roller 63 Pressurizing roller 100 Image forming device 110 Image reading unit 111 Feeding device 112 Scanner 112a CCD sensor 411 Exposure device 412 Developer 413 Electrophotosensitive Body 414 Charging device 415 Drum cleaning device 421 Intermediate transfer body 422 Primary transfer roller 423 Support roller 423A Backup roller 426 Belt cleaning device 426a Cleaning blade 431 Support roller 431A Secondary transfer roller 432 Secondary transfer belt D Original S paper

Claims (4)

導電性支持体と、前記導電性支持体上に配置された感光層と、前記感光層上に配置された表面層と、を有し、
前記表面層が、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂と、電荷輸送物質と、を含む、
電子写真感光体。
It has a conductive support, a photosensitive layer arranged on the conductive support, and a surface layer arranged on the photosensitive layer.
The surface layer contains a thermoplastic resin having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, and a charge transporting substance.
Electrophotographic photosensitive member.
前記熱可塑性樹脂が、溶媒に可溶なポリイミド樹脂である、
請求項1に記載の電子写真感光体。
The thermoplastic resin is a polyimide resin that is soluble in a solvent.
The electrophotographic photosensitive member according to claim 1.
請求項1または2に記載の電子写真感光体と、
前記電子写真感光体を帯電させるための接触帯電部材と、
を有する、画像形成装置。
The electrophotographic photosensitive member according to claim 1 or 2,
A contact charging member for charging the electrophotographic photosensitive member and
An image forming apparatus.
導電性支持体上に感光層を配置する工程と、
前記感光層上に、電子受容性を有し、かつガラス転移温度が225℃以上350℃以下である熱可塑性樹脂、電荷輸送物質、および沸点が40℃以上150℃以下である溶媒を含む表面層組成物を塗布し、表面層を形成する工程と、
を有する、電子写真感光体の製造方法。
The process of arranging the photosensitive layer on the conductive support and
A surface layer on the photosensitive layer containing a thermoplastic resin having electron acceptability and a glass transition temperature of 225 ° C. or higher and 350 ° C. or lower, a charge transporting substance, and a solvent having a boiling point of 40 ° C. or higher and 150 ° C. or lower. The process of applying the composition to form the surface layer and
A method for manufacturing an electrophotographic photosensitive member.
JP2020137498A 2020-08-17 2020-08-17 Electrophotographic photoreceptor and method for manufacturing the same, and image forming apparatus Pending JP2022033542A (en)

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