JP2007192905A - Electrophotographic photoreceptor, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly durable and stable electrophotographic photoreceptor which stably exhibits excellent electrophotographic characteristics even in repeated use so that its surface properties do not deteriorate over a prolonged period of time. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer on a conductive support, wherein the photosensitive layer contains a compound obtained by polymerizing a hole transport compound having a siloxane bond and a chain polymerizable functional group, such as a compound represented by formula (1), wherein A<SP>1</SP>is a (l+m)valent hole transporting group; Z<SP>1</SP>is a divalent hydrocarbon group; R<SP>1</SP>-R<SP>3</SP>are each independently an optionally substituted alkyl group, an optionally substituted aryl group or a specific group having a siloxane bond and a chain polymerizable group, provided that at least one of R<SP>1</SP>-R<SP>3</SP>is the specific group; R<SP>4</SP>is a group represented by -Z<SP>2</SP>-P<SP>1</SP>; Z<SP>2</SP>is a divalent hydrocarbon group; P<SP>1</SP>is a chain polymerizable group; l is 0 or an integer of ≥1; and m is an integer of ≥1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

  Conventionally, inorganic materials such as selenium, cadmium sulfide and zinc oxide have been known as photoconductive materials used for electrophotographic photoreceptors. On the other hand, polyvinylcarbazole, phthalocyanine, and azo pigments, which are organic materials, are attracting attention for advantages such as high productivity and non-pollution, and tend to be inferior in terms of photoconductive properties and durability compared to inorganic materials. , Has come to be widely used. These electrophotographic photoreceptors are often used as function-separated electrophotographic photoreceptors in which a charge generation layer and a charge transport layer are laminated in order to satisfy both electrical and mechanical characteristics.

  On the other hand, as a matter of course, the electrophotographic photosensitive member is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. In particular, in an electrophotographic photosensitive member that is repeatedly used, an electric or mechanical external force such as charging, image exposure, toner development, transfer to a transfer material, or cleaning treatment is directly applied to the surface of the electrophotographic photosensitive member. Therefore, durability and stability against them are required. Specifically, durability against the occurrence of surface wear and scratches due to rubbing, surface degradation resistance against discharge products such as ozone and nitrogen oxide during charging, and the like are required. In addition, it is necessary to reduce the energy of the surface of the electrophotographic photosensitive member in order to impart toner adhesion preventing ability to the electrophotographic photosensitive member and excellent cleaning properties and transferability.

  In general, the surface of an electrophotographic photoreceptor is a thin resin layer, and the characteristics of the resin are very important. In recent years, an acrylic resin, a polycarbonate resin, or the like has been selected as a resin that satisfies the above-described conditions to some extent, and has been widely put into practical use as a charge transport layer mixed with a charge transport material.

  However, the surface layer as described above has a limit in mechanical strength because it is a thermoplastic polymer, and a large amount of low-molecular charge transport materials are mixed for the purpose of satisfying electrical characteristics. In terms of wear resistance, it is not sufficient, and various studies have been made.

As an example, it is effective to use a curable resin as the surface protective layer. (For example, refer to Patent Document 1 and Patent Document 2.) A surface layer using an ultraviolet curable resin and a thermosetting resin is disclosed, and an improvement in durability is shown. Among them, curable acrylic resins are used as various hard coats because of their high reactivity and high curing speed, and sufficient durability can be obtained even when they are used in the surface layer of electrophotographic photoreceptors. It has been shown that (For example, Patent Document 3)
There is also an attempt to use a curable resin as a resin for the charge transport layer. (For example, Patent Document 4) Thus, the mechanical strength is increased by curing and crosslinking the charge transport layer using a curable resin as the resin for the charge transport layer, and the abrasion resistance and scratch resistance during repeated use are increased. improves.

  Furthermore, a charge transport material having a carbon-carbon double bond is reacted with heat or light energy to be chemically bonded to the charge transport matrix (for example, Patent Document 5 and Patent Document 6), or a thermoplastic polymer chain. A method for improving the mechanical strength of the surface layer of an electrophotographic photosensitive member by introducing a group having a charge transporting ability (for example, Patent Document 7) is disclosed.

  By increasing the surface hardness in this way, it is possible to improve the wear resistance and scratch resistance, but the decrease in the amount of wear with respect to the usage time of the photoreceptor is due to the accumulation of deterioration due to the discharge products described above. From the viewpoint of this, it cannot be denied that it is a disadvantageous direction, and simply increasing the hardness does not mean that a long-life photoreceptor is completed.

  In response to the problem of deterioration of the discharge product of the curable surface layer, an attempt to achieve both strength and surface characteristics by providing a crosslinkable surface layer using a hydrolyzable siloxane compound has been proposed (for example, patent document) 8) Yes. However, when a hydrolyzable compound is used, the polarity after film formation is high and sufficient hole transportability cannot be obtained. Furthermore, there is a problem of reaction between the hydrolyzable group and moisture in the atmosphere, which causes manufacturing problems such as optimization of film forming conditions and coating stability.

  When the surface hardness is increased and the wear resistance is improved, the deterioration accumulation of discharge products and the like tends to increase. This is because the cleaning property and the image flow become severe in the long-term repeated use of the electrophotographic photosensitive member. Direction. This phenomenon is caused by the wear speed and accumulation speed of an electrophotographic photosensitive member formed using a thermoplastic surface layer such as polycarbonate resin or polyarylate resin whose wear speed is about 10 to 100 times that of a cured surface layer. However, this is not a big problem because the wear speed is equal or higher, but it is a particularly significant problem for the hardened surface layer.

  On the other hand, reducing the energy of the surface of the electrophotographic photosensitive member is an important issue in order to impart toner adhesion preventing ability to the electrophotographic photosensitive member and excellent cleaning properties and transferability as described above. In order to improve such characteristics, it has been proposed to add a material having lubricity to the photosensitive layer, such as a silicon atom or a fluorine atom-containing compound. However, the inclusion of these materials tends to hinder the hole transport property, which causes problems such as endurance potential fluctuations and ghost images.

  In addition, the compatibility between the constituent materials used in the photosensitive layer and the materials added to impart lubricity is low, and there are problems with solubility and liquid stability when used as a coating solution. In addition, the coatability is extremely deteriorated, and problems such as layer separation during film formation or after film formation are likely to occur. Also, due to its high surface migration, it tends to be present in a high concentration only on the surface layer of the electrophotographic photosensitive member, and although it exhibits high lubricity at the beginning, as soon as the electrophotographic photosensitive member is scraped off due to repeated use, its lubrication is achieved. However, there is a problem that a sufficient effect cannot be obtained due to the deterioration of the properties, and that the toner adheres to the silicone component transferred to the surface. In particular, in the case of a curable surface layer, there is a tendency for the accumulation of discharge deterioration to increase with respect to the wear speed, and the action of the lubricant becomes more necessary as the surface layer goes inward than the extreme surface.

  In Patent Document 9, the necessity of optimizing the coating method and drying conditions for the surface layer containing the silicone compound is mentioned in order to solve the problem of the surface migration property of the silicone compound. The manufacturing method is complicated.

  Furthermore, when the surface layer contains a hole transport material, a phenomenon that the hole mobility is lowered by the addition of the silicone compound may occur. On the contrary, depending on the type of lubricant to be added, charge injection near the interface may be caused by being extremely unevenly distributed in the part opposite to the surface (and therefore near the interface between the surface layer and the layer below it). There was also a problem of being disturbed and affecting the potential characteristics.

In Patent Document 10, the problem of surface migration is solved by polymerizing a silicone-based lubricant having a chain polymerizable functional group and a hole transport agent containing a chain polymerizable functional group. From the viewpoint of the use of the electrophotographic photosensitive member in the process, further improvement is necessary to solve the influence of the above-described silicone-based lubricant on the hole transportability and the problem of accumulation of discharge deterioration.
JP-A-51-66834, JP-A 64-72167, JP-A 61-5253, Japanese Patent Laid-Open No. 2-127652, JP-A-5-216249, Japanese Patent Laid-Open No. 7-72640 JP-A-8-248649 JP 2000-171990 A JP 2000-298361 A JP 2001-66561 A JP 2000-66425 A JP 54-143645 A JP-A-10-115612

  An object of the present invention is to provide a highly durable and highly stable electrophotographic photoreceptor that exhibits excellent and excellent electrophotographic characteristics even when used repeatedly, and whose surface properties do not deteriorate over a long period of time.

  Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

  [1] In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer is polymerized with a hole transporting compound having a siloxane bond and a chain polymerizable functional group represented by the following general formula (1). An electrophotographic photoreceptor comprising the above compound.

（式中、Ａ¹は（ｌ＋ｍ）価の正孔輸送性基を示す；Ｚ¹は２価の炭化水素基を示す；Ｒ¹〜Ｒ³はそれぞれ独立に置換基を有してもよいアルキル基、置換基を有してもよいアリール基又は下記一般式（２）で示される基を示す；但し、Ｒ¹〜Ｒ³の少なくとも１つは下記一般式（２）で示される基である；Ｒ⁴は−Ｚ²−Ｐ¹で示される基を示す；Ｚ²は２価の炭化水素基を示す；Ｐ¹は連鎖重合性基を示す；ｌは０又は１以上の整数を示し、ｍは１以上の整数を示す）

(In the formula, A ¹ represents a (l + m) -valent hole transporting group; Z ¹ represents a divalent hydrocarbon group; R ^{1 to} R ³ each independently represents an alkyl which may have a substituent. A group, an aryl group which may have a substituent, or a group represented by the following general formula (2); provided that at least one of R ^{1 to} R ³ is a group represented by the following general formula (2); R ⁴ represents a group represented by -Z ² -P ¹ ; Z ² represents a divalent hydrocarbon group; P ¹ represents a chain polymerizable group; l represents 0 or an integer of 1 or more; m represents an integer of 1 or more)

（式中、Ｚ³は２価の炭化水素基を示す；Ｒ⁵及びＲ⁶はそれぞれ独立に置換基を有してもよいアルキル基、置換基を有してもよいアリール基を示す；Ｐ²は連鎖重合性基を示す；ｎは１以上の整数を示す）
［２］
上記一般式（1）におけるｌ＋ｍが４以下である［１］の電子写真感光体
［３］
上記一般式（1）におけるｎの平均個数が１４以下である［１］〜［２］のいずれかに記載の電子写真感光体
［４］
該感光体の最表面層が上記一般式（１）で示すようなシロキサン結合及び連鎖重合性官能基を有する正孔輸送性化合物を重合した化合物を含有することを特徴とする［１］〜［３］のいずれかに記載の電子写真感光体。

(In the formula, Z ³ represents a divalent hydrocarbon group; R ⁵ and R ⁶ each independently represents an alkyl group which may have a substituent or an aryl group which may have a substituent; P ² represents a chain polymerizable group; n represents an integer of 1 or more)
[2]
The electrophotographic photosensitive member of [1], wherein l + m in the general formula (1) is 4 or less [3]
The electrophotographic photosensitive member according to any one of [1] to [2], wherein the average number of n in the general formula (1) is 14 or less [4]
The outermost surface layer of the photoreceptor contains a compound obtained by polymerizing a hole transporting compound having a siloxane bond and a chain polymerizable functional group as shown in the general formula (1). 3]. The electrophotographic photosensitive member according to any one of [3].

[5]
The electrophotographic photosensitive member according to any one of [1] to [4], wherein the polymerization is performed by radiation.

[6]
An image forming apparatus that integrally supports the electrophotographic photosensitive member according to any one of [1] to [5] and at least one unit selected from a charging unit, a developing unit, a transfer unit, and a cleaning unit. A process cartridge for an image forming apparatus, which is detachable from a main body.

[7]
An image forming apparatus having at least a photoconductor, a charging unit, an image exposure unit, a developing unit, and a transfer unit, wherein the electrophotographic photoconductor according to any one of [1] to [5] is used as the photoconductor. An image forming apparatus.

  According to the present invention, in an electrophotographic photosensitive member having a highly curable, highly durable, and long-life surface layer, there is no problem in compatibility, and stable and excellent electrophotographic characteristics are exhibited even during repeated use. Thus, it is possible to provide a highly durable and highly stable electrophotographic photosensitive member that does not deteriorate its surface property.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  The present invention relates to a material for a photoreceptor surface layer that can provide a highly durable and highly stable electrophotographic photoreceptor that exhibits excellent electrophotographic characteristics even when used repeatedly and does not deteriorate its surface properties over a long period of time. As a result of intensive studies by the inventors, the following considerations were obtained.

(1) The siloxane bond-containing compound has an effect of suppressing deterioration of the surface of the photoreceptor due to discharge and further suppressing the accumulation of discharge products generated by discharge of nitrogen oxide or the like on the surface of the photoreceptor (2). Incorporating hole transporting groups and chain polymerizable groups into the molecular structure of the siloxane bond-containing compound suppresses the surface migration of the siloxane bond-containing compound and makes it almost uniformly present in the surface layer. Even if the body is worn, the surface modification effect of the siloxane bond is not impaired. (3) By having a hole transporting group, siloxane bond, and chain polymerizable group in the same molecular structure, chain polymerization is possible. It is possible to incorporate a hole transport unit and a siloxane unit into a three-dimensional cured matrix that has been cross-linked and polymerized using a group to maintain a suitable hardness. (4) Three-dimensional cured matrix In this process, the presence of a siloxane bond between the hole transporting group and the chain polymerizable group gives flexibility to the arrangement of the hole transporting unit, so that the hole transporting unit can be arranged appropriately. (5) A compound having a highly hydrolyzable group such as an alkoxy group, a hydroxyl group, a halogen, or an amino group is affected by moisture in the air. However, the stability of the paint is improved by adopting a structure in which a silicon group does not contain a highly hydrolyzable group, so that the stability of the paint is improved. By incorporating a compound obtained by polymerizing a hole transporting compound having a siloxane bond and a chain polymerizable functional group as shown in the following general formula (1), a high curability, high durability, and long life table are provided. Electrophotographic photosensitive member having a layer has no problem in compatibility, exhibits stable and excellent electrophotographic characteristics even after repeated use, and has high durability and high stability without deterioration of surface properties over a long period of time. It has been found that a photographic photoreceptor can be provided.

（式中、Ａ¹は（ｌ＋ｍ）価の正孔輸送性基を示す；Ｚ¹は２価の炭化水素基を示す；Ｒ¹〜Ｒ³はそれぞれ独立に置換基を有してもよいアルキル基、置換基を有してもよいアリール基又は下記一般式（２）で示される基を示す；但し、Ｒ¹〜Ｒ³の少なくとも１つは下記一般式（２）で示される基である；Ｒ⁴は−Ｚ²−Ｐ¹で示される基を示す；Ｚ²は２価の炭化水素基を示す；Ｐ¹は連鎖重合性基を示す；ｌは０又は１以上の整数を示し、ｍは１以上の整数を示す）

(In the formula, A ¹ represents a (l + m) -valent hole transporting group; Z ¹ represents a divalent hydrocarbon group; R ^{1 to} R ³ each independently represents an alkyl which may have a substituent. A group, an aryl group which may have a substituent, or a group represented by the following general formula (2); provided that at least one of R ^{1 to} R ³ is a group represented by the following general formula (2); R ⁴ represents a group represented by -Z ² -P ¹ ; Z ² represents a divalent hydrocarbon group; P ¹ represents a chain polymerizable group; l represents 0 or an integer of 1 or more; m represents an integer of 1 or more)

（式中、Ｚ³は２価の炭化水素基を示す；Ｒ⁵及びＲ⁶はそれぞれ独立に置換基を有してもよいアルキル基、置換基を有してもよいアリール基を示す；Ｐ²は連鎖重合性基を示す；ｎは１以上の整数を示す）
また、正孔輸送性基の周りに必要以上に連鎖重合性基が存在すると正孔輸送性基の配置に柔軟性がなくなり、正孔輸送性能が落ちる傾向にあるため、上記一般式（１）におけるｌ＋ｍは４以下であることが好ましい。

(In the formula, Z ³ represents a divalent hydrocarbon group; R ⁵ and R ⁶ each independently represents an alkyl group which may have a substituent or an aryl group which may have a substituent; P ² represents a chain polymerizable group; n represents an integer of 1 or more)
In addition, if a chain polymerizable group is present more than necessary around the hole transporting group, the arrangement of the hole transporting group is not flexible and the hole transporting performance tends to be lowered. L + m in is preferably 4 or less.

  Furthermore, if the siloxane chain length becomes too long, it becomes difficult to suppress the surface migration of siloxane, so the average number of n in the general formula (1) is preferably 14 or less.

  As the chain-polymerizable group, an optimal group selected from functional groups capable of general addition reaction, condensation reaction, dehydration reaction, polymerization reaction, crosslinking reaction, etc. is selected. Sex reactive groups are preferred. Examples of polymerization or crosslinkable reactive groups include chain polymerizable functional groups such as radical polymerization or ionic polymerization, sequential polymerizable functional groups such as addition condensation, polycondensation, and polyaddition, etc., from the viewpoint of reaction efficiency. Chain polymerizable functional groups are preferred. Here, the chain polymerizable functional group will be described in detail.

  The chain polymerization in the present invention refers to the former polymerization reaction mode when the polymer formation reaction is largely divided into chain polymerization and sequential polymerization. For details, see, for example, “Basic Chemistry Resin Chemistry” by Tadahiro Miwa. (New Edition) ”July 25, 1995 (1 edition, 8 prints) As described in FIG. 24, the form mainly refers to unsaturated polymerization, ring-opening polymerization, isomerization polymerization, etc. in which the reaction proceeds via an intermediate such as a radical or ion. Here, specific examples of unsaturated polymerization or ring-opening polymerizable functional groups that occupy most of them and have a wide application range are shown.

  Unsaturated polymerization is a reaction in which unsaturated groups such as C═C, C≡C, C═O, C═N, and C≡N are polymerized by radicals, ions, etc., but mainly C═C. It is. Specific examples of the unsaturated polymerizable functional group are shown in Table 1, but are not limited thereto.

表中、Ｒは置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有しても良いベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有しても良いフェニル基、ナフチル基及びアンスリル基等のアリール基又は水素原子を示す。

In the table, R is an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an optionally substituted benzyl group, a phenethyl group, a naphthylmethyl group, a furfuryl group, and An aryl group such as a thienyl group, an aryl group such as a phenyl group, a naphthyl group and an anthryl group which may have a substituent, or a hydrogen atom.

  Ring-opening polymerization means that unstable cyclic structures with distortions such as carbocycles, oxo rings, and nitrogen heterocycles are activated by the action of a catalyst, and at the same time, the polymerization is repeated to produce a chain polymer. In this case, basically, in this case, most of the ions act as active species. Specific examples of the ring-opening polymerizable functional group are shown in Table 2, but are not limited thereto.

表中、Ｒは置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有しても良いベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有しても良いフェニル基、ナフチル基及びアンスリル基等のアリール基又は水素原子を示す。

In the table, R is an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an optionally substituted benzyl group, a phenethyl group, a naphthylmethyl group, a furfuryl group, and An aryl group such as a thienyl group, an aryl group such as a phenyl group, a naphthyl group and an anthryl group which may have a substituent, or a hydrogen atom.

  Among these chain polymerizable groups, the following are preferable.

正孔輸送性基は、正孔輸送性を示すものであればいずれのものでもよい。このような正孔輸送性基としては、例えば、特許文献１１に記載されているような正孔輸送性基が挙げられる。より具体的には、正孔輸送性基に結合する他の官能基を水素原子に置き換えた水素付加化合物（正孔輸送性化合物）として示したときに、例えばオキサゾール誘導体、オキサジアゾール誘導体、イミダゾール誘導体、ジフェニルアミンやトリフェニルアミン等のジ又はトリアリールアミン誘導体、９−（ｐ−ジエチルアミノスチリル）アントラセン、１，１−ビス−（４−ジベンジルアミノフェニル）プロパン、スチリルアントラセン、スチリルピラゾリン、フェニルヒドラゾン類、チアゾール誘導体、トリアゾール誘導体、フェナジン誘導体、アクリジン誘導体、ベンゾフラン誘導体、ベンズイミダゾール誘導体、チオフェン誘導体及びＮ−フェニルカルバゾール誘導体等が挙げられる。

The hole transporting group may be any group as long as it exhibits hole transportability. Examples of such a hole transporting group include a hole transporting group described in Patent Document 11. More specifically, when it is shown as a hydrogenation compound (hole transporting compound) in which another functional group bonded to the hole transporting group is replaced with a hydrogen atom, for example, an oxazole derivative, an oxadiazole derivative, an imidazole Derivatives, di- or triarylamine derivatives such as diphenylamine and triphenylamine, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenyl Examples include hydrazones, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and N-phenylcarbazole derivatives.

  Further, among the hole transporting compounds, those represented by the following general formula (3) are preferable.

式中、Ａｒ¹、Ａｒ²及びＡｒ³は置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基及び置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、ガルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示す。

In the formula, Ar ¹ , Ar ² and Ar ³ are phenyl groups which may have a substituent and may have an aralkyl group and a substituent such as a benzyl group, a phenethyl group, a naphthylmethyl group, a furfuryl group and a thienyl group. , Naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, galvazolyl group, phenothiazinyl group, benzofuryl group, benzothiophenyl group, dibenzofuryl group and dibenzothiophenyl group An aryl group such as a group is shown.

In addition, any two of Ar ¹ , Ar ² and Ar ^{3 in} the general formula (3) may be bonded directly or via a bonding group, and the bonding group may be a methylene group or an ethylene group. And an alkylene group such as a propylene group, a hetero atom such as an oxygen atom and a sulfur atom, and a CH═CH group.

  Examples of the hole transporting compound in the present invention are shown below. However, the hole transporting compound of the present invention is not limited to the exemplified compounds.

本発明の電子写真感光体の構成は、導電性支持体上に感光層として電荷発生材料を含有する電荷発生層及び電荷輸送材料を含有する電荷輸送層をこの順に積層した構成あるいは逆に積層した構成、また電荷発生材料と電荷輸送材料を同一層中に分散した単層からなる構成のいずれの構成をとることも可能である。前者の積層型においては、電荷輸送層が二層以上の構成、また後者の単層型においては、電荷発生材料と電荷輸送材料を同一に含有する感光層上に更に電荷輸送層を構成してもよく、更には電荷発生層あるいは電荷輸送層上に保護層の形成も可能である。

The electrophotographic photosensitive member of the present invention has a structure in which a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are laminated in this order on a conductive support, or vice versa. It is possible to adopt any configuration including a single layer in which the charge generation material and the charge transport material are dispersed in the same layer. In the former stacked type, the charge transport layer has two or more layers. In the latter single layer type, a charge transport layer is further formed on the photosensitive layer containing the same charge generating material and charge transport material. Further, a protective layer can be formed on the charge generation layer or the charge transport layer.

  The support that the electrophotographic photosensitive member has is only required to have conductivity. For example, aluminum or copper, chromium, nickel, zinc, stainless steel or other metal or alloy molded into a drum or sheet, aluminum or copper or other metal foil laminated on a plastic film, aluminum, indium oxide or tin oxide Or the like deposited on a plastic film, a metal provided with a conductive layer by applying a conductive substance alone or with a binder resin, a plastic film, and paper.

  In the present invention, an undercoat layer having a barrier function and an adhesive function can be provided between the support and the photosensitive layer. The undercoat layer is used to improve the adhesion of the photosensitive layer, improve coating properties, protect the support, cover defects on the support, improve charge injection from the support, and protect against electrical breakdown of the photosensitive layer. It is formed.

  Materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue and gelatin Etc. The undercoat layer is formed by applying a solution prepared by dissolving these materials in a solvent suitable for each of the materials onto a support and drying it. The film thickness is preferably 0.1 to 2 μm.

  The stacked charge generation layer is composed of at least a charge generation material and a binder resin. Examples of charge generation materials include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals and crystal systems, specifically, phthalocyanine compounds having crystal types such as α, β, γ, ε, and X type, Examples include anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, quinocyanine, and amorphous silicon described in Patent Document 12.

  As binder resin, polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, polyvinyl acetal, polycarbonate, polyester , Polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin and epoxy resin.

  The charge generation layer is obtained by dispersing the charge generation material together with 0.3 to 4 times the amount of binder resin and solvent by a method such as homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, adrider and roll mill. The resulting dispersion is applied and dried, or is formed as a single composition film such as a vapor-deposited film of the charge generation material. The film thickness is preferably 5 μm or less, and particularly preferably 0.1 to 2 μm.

  The hole transporting compound having a siloxane bond and a chain polymerizable functional group in the present invention can be used as a charge transporting layer on the charge generation layer described above. Or after forming the 1st charge transport layer which consists of a charge transport substance and binder resin on a charge generation layer, it can use as a 2nd charge transport layer. In the case of a single layer in which the charge generating material and the charge transporting material are dispersed in the same layer, the hole transporting compound having a siloxane bond and a chain polymerizable functional group in the present invention can be used as the charge transporting material. . Alternatively, it can be used as a charge transport layer on a layer in which the charge generation material and the charge transport material are dispersed in the same layer.

  In any case, it is preferable to carry out polymerization / crosslinking reaction after applying the solution containing the hole transporting compound, but after reacting the solution containing the hole transporting compound in advance to obtain a cured product, again, It is also possible to form the surface layer using a material dispersed or dissolved in a solvent.

  A hole transporting compound having a siloxane bond and a chain polymerizable functional group can be used as the charge transporting layer. The thickness of the charge transport layer is preferably 1 to 50 μm, and particularly preferably 3 to 30 μm.

  When a hole transporting compound having a siloxane bond and a chain polymerizable functional group is used as the second charge transporting layer or the charge transporting layer on the layer in which the charge generating material and the charge transporting material are dispersed in the same layer, it corresponds to the lower layer. The first charge transporting layer or the layer in which the charge generating material and the charge transporting material are dispersed in the same layer contains an appropriate charge transporting material, for example, a heterocyclic ring such as poly-N-vinylcarbazole and polystyrylanthracene, or a condensed polycyclic aromatic. High molecular compound, heterocyclic compounds such as pyrazoline, imidazole, oxazole, triazole and carbazole, triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole derivatives Low stilbene derivatives and hydrazine derivatives Can be formed by the child compounds A solution was dispersed / dissolved in a solvent is applied with a suitable binder resin (may be selected from among a resin for the charge generating layer described above), and dried.

  In this case, the ratio of the charge transporting material to the binder resin is preferably 20 to 70% by weight, more preferably 25 to 60% by weight, based on the total weight of both. . If the amount of the charge transport material is less than 20% by weight, the charge transport ability is lowered, and problems such as a decrease in sensitivity and an increase in residual potential are likely to occur. The total thickness of the charge transport layer combined with the upper surface protective layer is preferably 1 to 50 μm, and particularly preferably 5 to 30 μm.

  In any of the cases described above, in the present invention, the charge transport material can be contained in a photosensitive layer containing a cured product of a hole transport compound having a siloxane bond and a chain polymerizable functional group.

  When the hole transporting compound having a siloxane bond and a chain polymerizable functional group is used as the charge transporting layer, the amount of the hole transporting compound is based on the total mass of the charge transporting layer film after polymerization crosslinking. The total amount of the hydrogen adduct of the hole transporting group A1 represented by the general formula (1) and the charge transport material is preferably 20% by mass or more, and particularly preferably 40% by mass or more. If it is less than that, the charge transport ability is lowered, and problems such as a reduction in sensitivity and an increase in residual potential are likely to occur.

  In the case of a single layer type photosensitive layer, it is formed by polymerizing / crosslinking a solution containing both a hole transporting compound and a charge generation material, or a single layer type photosensitive layer containing a charge generation material and a charge transport material It is formed by polymerizing / crosslinking after applying a solution containing a hole transporting compound thereon.

  Various additives can be added to the photosensitive layer in the invention.

  Examples of the method for applying the solution for each layer include a dip coating method, a spray coating method, a curtain coating method, and a spin coating method. The dip coating method is preferable from the viewpoint of efficiency / productivity. Also, vapor deposition, plasma, and other known film forming methods can be appropriately selected.

  In the present invention, as a technique for polymerizing a hole transporting compound having a siloxane bond and a chain polymerizable functional group, it is preferable to use heat, high energy radiation such as ultraviolet rays, γ rays or electron beams, depending on circumstances. Can be used in combination with a polymerization initiator. However, initiators should be carefully selected because they can adversely affect electrophotographic properties. In particular, use of a high energy beam such as an electron beam is preferable in that an initiator is not required and the polymerization efficiency is high.

  When carrying out the polymerization reaction with heat, there are cases where the polymerization reaction proceeds only with thermal energy and a polymerization initiator may be required, but in order to advance the reaction efficiently at a lower temperature, an initiator is used. It is preferable to add.

  The polymerization initiator used in this case is not particularly limited as long as it has a half-life at room temperature or higher. Specific examples thereof include ammonium persulfate, dicumyl peroxide, benzoyl peroxide, cyclohexane peroxide, and t-butyl hydroperoxide. Examples thereof include peroxides such as oxide and di-t-butyl peroxide, and azo compounds such as azobisbutyronitrile. The addition amount is about 0.01 to 10 parts by weight with respect to 100 parts by weight of the compound having a chain polymerizable group, and the temperature of the reaction system can be appropriately selected between room temperature and 200 ° C. depending on the initiator.

  When a polymerization reaction is performed with ultraviolet rays, the reaction rarely proceeds only with light energy, and a photopolymerization initiator is generally used in combination.

  In this case, the polymerization initiator mainly refers to those that absorb ultraviolet rays having a wavelength of 400 nm or less to generate active species such as radicals and ions and initiate polymerization, and specific examples thereof include acetophenone, benzoin, Radical polymerization initiators such as benzophenone and thioxanthone, and ion polymerization initiators such as diazonium compounds, sulfonium compounds, iodonium compounds and metal complex compounds. In recent years, however, polymerization initiators that absorb light in the infrared / visible region at wavelengths of 400 nm or more to generate the above active species have been announced. Is possible. The addition amount of the initiator is about 0.01 to 50 parts by weight with respect to 100 parts by weight of the compound having a chain polymerizable group.

  In the present invention, the aforementioned heat and photopolymerization initiator can be used in combination.

  FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 in a direction indicated by an arrow at a predetermined peripheral speed. In the rotating process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then exposure light from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Receive 4. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1.

  The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner developed image is rotated between the photosensitive member 1 and the transfer unit 6 from a sheet feeding unit (not shown). The image is sequentially transferred by the transfer means 6 to the transfer material 7 that is synchronously taken out and fed. The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy).

  After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9 and further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown), and then repeatedly. Used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5 and the cleaning unit 9 described above are integrally coupled as a process cartridge. May be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photosensitive member 1 to form a cartridge and can be attached to and detached from the apparatus main body using guide means such as a rail 12 of the apparatus main body. The process cartridge 11 can be obtained.

  Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is a reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal, and scanning of the laser beam performed according to this signal, Light emitted by driving the LED array, driving the liquid crystal shutter array, or the like.

  The electrophotographic photosensitive member of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.

  Production examples of the hole transporting compound of the present invention will be shown. However, the following production examples show typical examples and may be produced according to other production methods.

(Synthesis example)
Synthesis of Compound S-1 Synthesis was performed according to the following route.

特許文献１３等に記載の正孔輸送性化合物Ａ７０部、市販の化合物Ｂ（３−アクリロキシプロピルジメチルエトキシシラン）１５０部とトルエン１５０部をフラスコに仕込み、１％塩酸水溶液１００部を２０分間かけて滴下した。滴下４０分後に攪拌を止め、分液後樹脂層を水洗して塩酸を除去した。そこへ活性白土５部を添加し３０分室温で攪拌処理した。活性白土を１．０μｍの濾紙を使用して濾過後、さらに０．５μｍのメンブランフィルターを用い濾過した。得られた濾液をそのままシリカゲルカラム（展開溶媒：トルエン）を用い分離精製し、化合物Ｓ−１を６５部得た。

70 parts of the hole transporting compound A described in Patent Document 13 and the like, 150 parts of a commercially available compound B (3-acryloxypropyldimethylethoxysilane) and 150 parts of toluene are charged into a flask, and 100 parts of 1% hydrochloric acid aqueous solution is applied for 20 minutes. And dripped. Stirring was stopped 40 minutes after the dropping, and after separation, the resin layer was washed with water to remove hydrochloric acid. Thereto, 5 parts of activated clay was added and stirred for 30 minutes at room temperature. The activated clay was filtered using 1.0 μm filter paper, and further filtered using a 0.5 μm membrane filter. The obtained filtrate was separated and purified as it was using a silica gel column (developing solvent: toluene) to obtain 65 parts of compound S-1.

Example 1
First, the coating material for the conductive layer was prepared according to the following procedure. 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% by weight of antimony oxide, 25 parts of phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, An average molecular weight of 3000) 0.002 part was prepared by dispersing for 2 hours in a sand mill using φ1 mm glass beads. This paint was applied on an aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm by a dip coating method and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 16 μm.

  Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare an intermediate layer coating material. This paint was applied on the conductive layer by a dip coating method and dried at 100 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.6 μm.

  Next, 3 parts of crystalline hydroxygallium phthalocyanine having the strongest peak at 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction as a charge generating substance and polyvinyl butyral resin (trade name: ESREC BX) −1, manufactured by Sekisui Chemical Co., Ltd. 2 parts are added to 100 parts of cyclohexanone and dispersed in a sand mill using glass beads having a diameter of 1 mm for 1 hour, and 100 parts of methyl ethyl ketone is added thereto. A charge generation layer coating solution is prepared by dilution, and the charge generation layer coating solution is dip coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.15 μm. Formed.

  Next, 7.5 parts of the following hole transporting compound C,

ポリカーボネート樹脂（商品名：ユーピロンＺ２００、三菱瓦斯化学（株）製。ユーピロンは登録商標。）１０部をモノクロロベンゼン６０部に溶解した第一電荷輸送層用塗料を電荷発生層上に塗布し、１２０℃６０分間乾燥して１８μｍの第一電荷輸送層を得た。

A coating for a first charge transport layer in which 10 parts of polycarbonate resin (trade name: Iupilon Z200, manufactured by Mitsubishi Gas Chemical Co., Ltd., Iupilon is a registered trademark) in 60 parts of monochlorobenzene was applied onto the charge generation layer, and 120 The film was dried at 60 ° C. for 60 minutes to obtain an 18 μm first charge transport layer.

Furthermore, 60 parts of toluene was added to 30 parts of the hole transporting compound of Compound Example S-1 and dissolved on the first charge transporting layer to prepare a coating material for the second charge transporting layer.
This paint is coated on the first charge transport layer, and the resin is cured by irradiating with an electron beam under the conditions of an acceleration voltage of 150 kV and a dose of 2 Mrad to form a second charge transport layer having a thickness of 5 μm. Got the body.

(Example 2 to Example 9)
Instead of 30 parts of the hole transporting compound of Compound Example S-1 of Example 1, Compound Example No. The same as Example 1 except that 30 parts of the hole transporting compound of S-3, S-4, S-10, S-17, S-21, S-23, S-24, S-32 were used. An electrophotographic photosensitive member was produced.

(Example 10)
Instead of 30 parts of the hole transporting compound of Compound Example S-1 of Example 1, Compound Example No. An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that 24 parts of the S-8 hole transporting compound and 6 parts of the hole transporting compound C were used.

(Example 11)
Instead of 30 parts of the hole transporting compound of Compound Example S-1 of Example 1, Compound Example No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 27 parts of the hole transporting compound of S-24 and 3 parts of the following siloxane-containing compound D were used.

（実施例１２）
実施例１の化合物例Ｓ−１の正孔輸送性化合物３０部の代わりに化合物例Ｎｏ．Ｓ−２４の正孔輸送性化合物２４部と化合物例Ｎｏ．Ｓ−３８の正孔輸送性化合物６部を用いた他は実施例１と同様に電子写真感光体を作製した。

(Example 12)
Instead of 30 parts of the hole transporting compound of Compound Example S-1 of Example 1, Compound Example No. 24 parts of a hole transporting compound of S-24 and Compound Example No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 6 parts of the S-38 hole transporting compound was used.

(Example 13)
Instead of 30 parts of the hole transporting compound of Compound Example S-1 of Example 1, Compound Example No. 24 parts of a hole transporting compound of S-24 and Compound Example No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 6 parts of the hole transporting compound of S-39 was used.

(Example 14)
After forming the charge generation layer in Example 1, it was applied on the charge generation layer using a charge transport coating material in which 30 parts of the hole transporting compound of compound S-17 was dissolved in 60 parts of toluene, and the acceleration voltage was applied. The resin was cured by irradiating an electron beam under conditions of 150 kV and a dose of 5 Mrad to form a charge transport layer having a thickness of 20 μm, and an electrophotographic photosensitive member was produced.

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 30 parts of the hole transporting compound E shown below was used instead of 30 parts of the hole transporting compound of Example Compound S-1.

（比較例２）
実施例１の化合物例Ｓ−１の正孔輸送性化合物３０部の代わりに下記正孔輸送性化合物Ｆ・３０部を用いた他は実施例１と同様に電子写真感光体を作製した。

(Comparative Example 2)
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that 30 parts of the hole transporting compound F shown below was used instead of 30 parts of the hole transporting compound of Example Compound S-1 of Example 1.

（比較例３）
実施例１の化合物例Ｓ−１の正孔輸送性化合物３０部の代わりに化合物Ｃの正孔輸送性化合物２０部と化合物Ｄのシロキサン含有化合物１０部を用いた他は実施例１と同様に電子写真感光体を作製した。

(Comparative Example 3)
The same procedure as in Example 1 except that 20 parts of the hole transporting compound of Compound C and 10 parts of the siloxane-containing compound of Compound D were used instead of 30 parts of the hole transporting compound of Example Compound S-1 of Example 1. An electrophotographic photosensitive member was produced.

  The electrophotographic photoreceptor produced as described above was mounted on a copier IR-400 manufactured by Canon Inc. and evaluated in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The initial electrophotographic photosensitive member characteristics [dark portion potential Vd, bright portion potential Vl and residual potential Vsl (potential when a light amount of 3 times the amount of exposure light is irradiated)] are further measured, and 5,000 sheets per day for a total of 40000. A sheet passing durability test was performed, and the amount of scraping per 10,000 sheets of the electrophotographic photosensitive member was measured using an eddy current film thickness measuring device (manufactured by FISCHER, PERMASCOPE TYPE E111, PERMASCOPE is a registered trademark).

  Next, with an evaluation environment of 30 ° C. and a relative humidity of 80%, an endurance test of 10,000 sheets was performed in a mode in which an image in which characters are printed on a halftone image with A4 size paper is output intermittently. It was. Regarding the evaluation of the image flow at the time of the endurance test of 10000 sheets, rank A where no halftone disturbance is confirmed, rank B where slight density unevenness is observed, and rank B where there is slight density unevenness but no blurring of characters. Rank C was ranked D when the character flow was slightly seen, and rank E when the character flowed and could not be identified.

  Further, as an evaluation of the liquid stability, the state of the liquid after the prepared coating material for the second charge transport layer (charge transport paint in Example 13) was circulated in the atmosphere for 30 days so that the solid content did not change. Observation was evaluated as ○ when there was no change from when the paint was prepared, and × when discoloration or turbidity was confirmed.

  The evaluation results are summarized in the table.

FIG. 2 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge container 12 Guide means

Claims (7)

In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, a compound obtained by polymerizing a hole transporting compound having a siloxane bond and a chain polymerizable functional group, the photosensitive layer represented by the following general formula (1): An electrophotographic photosensitive member containing the electrophotographic photosensitive member.

(In the formula, A ¹ represents a (l + m) -valent hole transporting group; Z ¹ represents a divalent hydrocarbon group; R ¹ to R ³ each independently represents an alkyl which may have a substituent. A group, an aryl group which may have a substituent, or a group represented by the following general formula (2); provided that at least one of R ¹ to R ³ is a group represented by the following general formula (2) R ⁴ represents a group represented by -Z ² -P ¹ ; Z ² represents a divalent hydrocarbon group; P ¹ represents a chain polymerizable group; l represents 0 or an integer of 1 or more; m represents an integer of 1 or more)

(In the formula, Z ³ represents a divalent hydrocarbon group; R ⁵ and R ⁶ each independently represents an alkyl group which may have a substituent or an aryl group which may have a substituent; P ² represents a chain polymerizable group; n represents an integer of 1 or more)   The electrophotographic photosensitive member according to claim 1, wherein l + m in the general formula (1) is 4 or less.   The electrophotographic photosensitive member according to claim 1, wherein the average number of n in the general formula (1) is 14 or less.   The outermost surface layer of the photoreceptor contains a compound obtained by polymerizing a hole transporting compound having a siloxane bond and a chain polymerizable functional group as represented by the general formula (1). Item 4. The electrophotographic photosensitive member according to any one of Items 3.   The electrophotographic photosensitive member according to claim 1, wherein the polymerization is performed by radiation.   An image forming apparatus comprising: an electrophotographic photosensitive member according to claim 1; and at least one unit selected from a charging unit, a developing unit, a transfer unit, and a cleaning unit. A process cartridge for an image forming apparatus, which is detachable from a main body.   An image forming apparatus having at least a photoconductor, a charging unit, an image exposure unit, a developing unit, and a transfer unit, wherein the electrophotographic photoconductor according to any one of claims 1 to 5 is used as the photoconductor. An image forming apparatus.

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