JP2008070665A - Image forming apparatus, image forming method and process cartridge included in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus using an electrophotographic photoreceptor and toner, which can suppress degradation of an image due to cleaning failure for a long period of time, suppress filming of the toner on the photoreceptor surface and output favorable images. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer on a conductive support and contains fluorocarbon resin fine particles in an outermost surface layer. The fluorocarbon resin fine particles exhibit the following property: the total (projected) area ratios of particles in a range of 0.15≤D≤3 μm with respect to the surface is always kept to 10% to 60% in an initial state and in a polished state of the outermost surface with the lapse of time, wherein D represents an average diameter of primary particles and secondary particles formed by aggregation of a plurality of the primary particles (as projected images of portions exposed to the surface). The toner used in a developing means contains a toner binder made of a polycondensation polyester resin, wherein the polyester resin is prepared in the presence of a titanium-containing catalyst having a specified structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member and a toner that can output a good image without causing defective cleaning even when used repeatedly for a long period of time. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using those toners.

In an image forming apparatus using an electrophotographic method, by conventionally reducing the coefficient of friction on the surface of the photoconductor, unnecessary toner adhesion is prevented, and toner remaining on the photoconductor without being transferred is removed by a blade or It is known that poor cleaning hardly occurs when cleaning with a brush.
Furthermore, it is known that reducing the coefficient of friction on the surface of the photoconductor improves the transfer rate when the toner image formed on the photoconductor is transferred to the transfer target, which leads to suppression of worm-engraving prints. It has been.
Further, since the amount of residual toner after transfer can be reduced, the amount of waste toner can be reduced, and the torque for driving the photosensitive member can be reduced, so that the power consumption of the image forming apparatus can be reduced. Is also known to be obtained.
In particular, with regard to cleaning, recently, due to the demand for higher image quality of electrophotography, it is clear that a high effect can be obtained for cleaning spherical toner produced using an emulsion polymerization method or a suspension polymerization method. It is becoming.
In general, for cleaning the transfer residual toner on the photosensitive member, a method is employed in which a blade formed of urethane rubber or the like is brought into contact with the counter direction and the toner is removed by the blade. However, the spherical toner tends to slip through the contact portion between the cleaning blade and the photosensitive member as compared with the irregular toner, so that the toner tends to slip through and often causes poor cleaning. On the other hand, by reducing the coefficient of friction on the surface of the photosensitive member, slipping of the spherical toner can be suppressed, and defective cleaning can be suppressed.

  As a method for reducing the coefficient of friction on the surface of the photoconductor, a mechanism for supplying a lubricant to the surface of the photoconductor is provided as proposed in Japanese Patent Laid-Open No. 56-142567. An image forming apparatus has been proposed and put into practical use. However, since such a mechanism is provided around the photosensitive member, an increase in size and complexity of the apparatus cannot be avoided, and problems such as an increase in cost and deterioration in maintainability occur.

Further, as a different method for reducing the coefficient of friction of the photoreceptor, it has been proposed to add a lubricant that reduces the friction coefficient to the surface layer of the photoreceptor. Specifically, there is one proposed in Patent Document 2 (Japanese Patent Laid-Open No. 63-31356).
Lubricants include fluorine atom-containing resins such as polytetrafluoroethylene (hereinafter referred to as fluororesins), spherical acrylic resins, polyethylene resins, etc., metal oxide powders such as silicon oxide and aluminum oxide, and silicone oils. Sexual liquids are known. In particular, a fluororesin containing a large amount of fluorine atoms has a large effect as a lubricant because the surface energy is extremely small. Such a fluororesin is used as crystalline fine particles, and after being dispersed in a binder resin such as an acrylic resin, a polyester resin, a polyurethane resin, or a polycarbonate resin, it is formed as a surface layer or a protective layer of the photoreceptor. The
However, when the content of the fluororesin fine particles is relatively small, even if the initial friction coefficient of the photoreceptor surface can be reduced, if the image is repeatedly output, the friction coefficient gradually increases. Therefore, it is conceivable to increase the amount of the fluororesin fine particles added as a means for maintaining a low friction coefficient. However, the property of the fluororesin fine particles has a problem that the tendency of aggregation in the resin solution is strong and uniform dispersion is difficult.

For example, various investigations have been made and proposed for the dispersion method of fluororesin fine particles, and specifically, there are techniques described in Patent Documents 3 to 9.
However, most of the fluororesin fine particle-containing surface layers produced by these methods have a relatively small content, which is insufficient to maintain a low coefficient of friction over a long period of time. Further, in Patent Document 5 (Japanese Patent Laid-Open No. 6-130711) having a description with a large content, there is no description about the particle size after dispersion, and since the content of the fluororesin fine particles is high, it is more likely to aggregate, It is considered difficult to finely disperse. When a coating film is formed using such a coating liquid, there are many large secondary aggregated particles in the coating film, and the unevenness of the coating film surface becomes large, or the fluororesin on the coating film surface. Cause localization of fine particles. If the unevenness on the surface of the coating film becomes large, it may be considered that cleaning failure or toner image disturbance is caused. Further, the localization of the fluororesin fine particles may cause a defective cleaning because the surface of the photoreceptor coating film has a microscopically high friction coefficient portion and a low friction coefficient portion. Furthermore, if the secondary aggregation diameter of the fluorine fine particles is too large, the laser light is scattered on the aggregate, causing disturbance of the exposure latent image and insufficient potential contrast due to insufficient light quantity, which may cause abnormal images. is there.

On the other hand, Patent Document 10 (Japanese Patent Application Laid-Open No. 2005-37562) discloses that the primary particle and the secondary particle formed by agglomerating a plurality of primary particles after dispersion are present on the surface. The amount is prescribed.
In addition, the surface layer in which fluororesin fine particles are appropriately dispersed is also polished with inorganic fine particles such as silica and titanium oxide added to the toner for the refreshing effect to suppress filming, and the surface of the photoconductor is then polished. A method of always refreshing has also been proposed. However, with this technique, if the inorganic fine particles added to the toner are embedded in the toner due to stress over time, the surface layer of the photoreceptor becomes difficult to be scraped, so that it is not refreshed and filming cannot be suppressed. Conceivable.

JP 56-142567 A JP-A-63-131356 JP-A-5-045920 JP-A-5-265243 JP-A-6-130711 Japanese Patent No. 3097940 JP-A-8-087125 JP-A-8-179543 JP 2000-019765 A JP-A-2005-37562

The present invention maintains a state in which the coefficient of friction on the surface of the photoconductor that causes cleaning failure is reduced even after repeated use for a long period of time, thereby suppressing image deterioration due to poor cleaning over a long period of time. An electrophotographic photosensitive member capable of suppressing filming of toner on the surface of the photosensitive member over a long period of time by appropriately polishing the surface layer and outputting a good image, an image forming apparatus using the toner, and an image forming method Is to provide.
Furthermore, another object of the present invention is to provide a process cartridge for an image forming apparatus using such an electrophotographic photosensitive member and toner.

As a result of intensive studies to achieve the above-mentioned problems, the present inventor has found that the object can be achieved by the following present inventions (1) to (16), and has achieved the present invention.
(1) “Charging means for uniformly charging the electrophotographic photosensitive member, exposure means for writing an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and electrostatic latent image formed on the surface of the electrophotographic photosensitive member A developing means for visualizing the image, a transfer means for transferring the visible image on the surface of the electrophotographic photosensitive member directly to the recording member or via an intermediate transfer body, and a fixing means for fixing the visible image on the recording member. An image forming apparatus comprising: cleaning means for cleaning the transfer residual toner on the photoconductor;
The electrophotographic photosensitive member has at least a photosensitive layer on a conductive support, contains fluororesin fine particles in the outermost layer, and the fluororesin fine particles have a plurality of primary particles and a plurality of primary particles in the outermost layer film. When the average diameter of the agglomerated secondary particles (in the projected image of the portion exposed on the surface) is D, the (projected) area of the particles in the range of 0.15 ≦ D ≦ 3 μm. The total ratio is always maintained at 10% to 60% even in the initial state and in the state where the outermost layer has been polished over time, and the toner used in the developing means has a toner binder made of a polycondensation polyester resin, An image forming apparatus, wherein the polyester resin is a resin formed in the presence of at least one titanium-containing catalyst (a) represented by the following general formula (I) or (II).

〔式中、Ｘは炭素数２〜１２のモノもしくはポリアルカノールアミンから１個のＯＨ基のＨを除いた残基であり、ポリアルカノールアミンの他のＯＨ基が、同一のＴｉ原子に直接結合したＯＨ基と分子内で重縮合し環構造を形成していてもよく、他のＴｉ原子に直接結合したＯＨ基と分子間で重縮合し繰り返し構造を形成していてもよい。繰り返し構造を形成する場合の重合度は２〜５である。ＲはＨ、または１〜３個のエーテル結合を含んでいてもよい炭素数１〜８のアルキル基である。ｍは１〜４の整数、ｎは０〜３の整数、ｍとｎの和は４である。ｐは１〜２の整数、ｑは０〜１の整数、ｐとｑの和は２である。ｍまたはｐが２以上の場合、それぞれのＸは同一であっても異なっていてもよい。］〕、
（２）「前記フッ素樹脂微微粒子の一次粒子、及び一次粒子が複数個凝集して形成された二次粒子のうち、平均直径Ｄが０．２≦Ｄ≦１．５μｍの範囲にある粒子の、表面にしめる投影面積比の合計が初期及び経時で最表層が研磨されていった状態でも常に１０％〜６０％を維持することを特徴とする前記第（１）項に記載の画像形成装置」、
（３）「前記フッ素樹脂微粒子の最表層にしめる割合が２０ｖｏｌ％〜７０ｖｏｌ％であることを特徴とする前記第（１）項又は第（２）項に記載の画像形成装置」、
（４）「前記感光層が、少なくとも電荷発生物質、電荷輸送物質を含有する層と、その上に積層された保護層とからなり、該保護層が少なくともバインダー樹脂とフッ素樹脂微粒子を含有する層であることを特徴とする前記第（１）項乃至第（３）項のいずれかに記載の画像形成装置」、
（５）「前記最表層に少なくとも電荷輸送物質を含有することを特徴とする前記第（１）項乃至第（４）項のいずれかに記載の画像形成装置」、
（６）「少なくとも電子写真感光体表面を接触して摺擦する接触部材を具備してなることを特徴とする前記第（１）項乃至第（５）項のいずれかに記載の画像形成装置」、
（７）「前記最表層に含有されるフッ素樹脂微粒子が、前記接触部材によって最表層表面上に延びて被覆されることを特徴とする前記第（６）項に記載の画像形成装置」、
（８）「前記チタン含有触媒（ａ）は、前記一般式（Ｉ）、（II）中のＸが、ジもしくはトリアルカノールアミンから１個のＯＨ基のＨを除いた残基であることを特徴とする前記第（１）項乃至第（７）項のいずれかに記載の画像形成装置」、
（９）「前記チタン含有触媒（ａ）は、前記一般式（Ｉ）、（II）中のｍまたはｐが２以上であり、Ｘがすべて同一の基であることを特徴とする前記第（１）項乃至第（８）項のいずれかに記載の画像形成装置」、
（１０）「前記トナーバインダーは、該ポリエステル樹脂の少なくとも一部がポリエポキシド（ｃ）で変性されてなることを特徴とする前記第（１）項乃至第（９）項のいずれかに記載の画像形成装置」、
（１１）「前記トナーは、トナーバインダー（Ａ）と着色剤（Ｂ）を含有することを特徴とする前記第（１）項乃至第（１０）項のいずれかに記載の画像形成装置」、
（１２）「前記トナーは、さらに、離型剤（Ｃ）、荷電制御剤（Ｄ）、および流動化剤（Ｅ）から選ばれる１種以上の添加剤を含有することを特徴とする前記第（１）項乃至第（１１）項のいずれかに記載の画像形成装置」、
（１３）「前記画像形成装置が、複数の電子写真感光体、帯電手段、現像手段、転写手段、クリーニング手段を有するタンデム型であることを特徴とする前記第（１）項乃至第（１２）項のいずれかに記載の画像形成装置」、
（１４）「前記画像形成装置が、電子写真感光体上に現像されたトナー画像を中間転写体上に一次転写したのち、該中間転写体上のトナー画像を記録材上に二次転写する中間転写手段を有する画像形成装置であって、複数色のトナー画像を中間転写体上に順次重ね合わせてカラー画像を形成し、該カラー画像を記録材上に一括で二次転写することを特徴とする前記第（１）項乃至第（１３）項のいずれかに記載の画像形成装置」、
（１５）「前記第（１）項乃至第（１４）項のいずれかに記載の画像形成装置を用いて画像を形成することを特徴とする画像形成方法」、
（１６）「画像形成装置に着脱自在で、導電性支持体上に少なくとも感光層を有し最表層にフッ素樹脂微粒子を含有し、該フッ素樹脂微粒子が最表層膜中において、一次粒子、及び一次粒子が複数個凝集して形成された二次粒子の（、表面に露出した部分の投影像の）平均直径をＤとした場合、０．１５≦Ｄ≦３μｍの範囲にある粒子の、表面にしめる（投影）面積比の合計が初期状態及び経時で最表層が研磨されていった状態でも常に１０％〜６０％を維持する電子写真感光体、又は、現像手段で使用されるトナーは、トナーバインダーが重縮合ポリエステル樹脂からなり、該ポリエステル樹脂が、下記一般式（Ｉ）または（II）で表わされる少なくとも１種のチタン含有触媒（ａ）の存在下に形成されてなる樹脂であるトナーを用いる現像手段を少なくとも有し、
画像形成装置に装着したときに、該画像形成装置が前記第（１）項乃至第（１４）項のいずれかに記載の画像形成装置を構成するものであることを特徴とする画像形成装置用プロセスカートリッジ。

[Wherein X is a residue obtained by removing H of one OH group from a mono- or polyalkanolamine having 2 to 12 carbon atoms, and other OH groups of polyalkanolamine are directly bonded to the same Ti atom. The OH group may be polycondensed in the molecule to form a ring structure, or the OH group directly bonded to another Ti atom may be polycondensed between the molecules to form a repeating structure. The degree of polymerization in the case of forming a repeating structure is 2-5. R is H or an alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds. m is an integer of 1 to 4, n is an integer of 0 to 3, and the sum of m and n is 4. p is an integer of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. When m or p is 2 or more, each X may be the same or different. ]],
(2) “Of the primary particles of the fluororesin fine particles and the secondary particles formed by agglomerating a plurality of primary particles, particles having an average diameter D in the range of 0.2 ≦ D ≦ 1.5 μm The image forming apparatus according to item (1), wherein the total projected area ratio applied to the surface is always maintained at 10% to 60% even in a state where the outermost layer is polished in the initial stage and over time. ,
(3) “The image forming apparatus according to (1) or (2) above, wherein the ratio of the fluororesin fine particles to the outermost layer is 20 vol% to 70 vol%”;
(4) “The photosensitive layer comprises a layer containing at least a charge generating substance and a charge transporting substance and a protective layer laminated thereon, and the protective layer contains at least a binder resin and fluororesin fine particles. The image forming apparatus according to any one of Items (1) to (3),
(5) "The image forming apparatus according to any one of (1) to (4) above, wherein the outermost layer contains at least a charge transport material",
(6) The image forming apparatus according to any one of (1) to (5), wherein the image forming apparatus includes a contact member that contacts and rubs at least the surface of the electrophotographic photosensitive member. "
(7) “The image forming apparatus according to (6) above, wherein the fluororesin fine particles contained in the outermost layer extend and are coated on the surface of the outermost layer by the contact member”,
(8) “In the titanium-containing catalyst (a), X in the general formulas (I) and (II) is a residue obtained by removing H of one OH group from di- or trialkanolamine. The image forming apparatus according to any one of (1) to (7),
(9) “The titanium-containing catalyst (a) is characterized in that m or p in the general formulas (I) and (II) are 2 or more, and X is the same group ( The image forming apparatus according to any one of 1) to 8),
(10) The image according to any one of (1) to (9), wherein the toner binder is formed by modifying at least a part of the polyester resin with a polyepoxide (c). Forming device ",
(11) “The image forming apparatus according to any one of Items (1) to (10), wherein the toner contains a toner binder (A) and a colorant (B)”,
(12) “The toner further includes one or more additives selected from a release agent (C), a charge control agent (D), and a fluidizing agent (E)”. The image forming apparatus according to any one of (1) to (11) ",
(13) The item (1) to (12), wherein the image forming apparatus is a tandem type having a plurality of electrophotographic photosensitive members, a charging unit, a developing unit, a transfer unit, and a cleaning unit. The image forming apparatus according to any one of items 1 to 3,
(14) “Intermediate transfer of the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member and then secondary transfer of the toner image on the intermediate transfer member onto the recording material. An image forming apparatus having transfer means, wherein a color image is formed by sequentially superimposing toner images of a plurality of colors on an intermediate transfer member, and the color image is secondarily transferred collectively onto a recording material. The image forming apparatus according to any one of (1) to (13),
(15) "Image forming method characterized in that an image is formed using the image forming apparatus according to any one of (1) to (14)",
(16) “Removable / attachable to / from the image forming apparatus, having at least a photosensitive layer on a conductive support and containing fluororesin fine particles in the outermost layer, wherein the fluororesin fine particles are primary particles and primary in the outermost layer film. When the average diameter of the secondary particles formed by agglomerating a plurality of particles (and the projected image of the portion exposed on the surface) is D, the particles are in the range of 0.15 ≦ D ≦ 3 μm. (Projection) The toner used in the electrophotographic photosensitive member or the developing means in which the total area ratio always maintains 10% to 60% even in the initial state and the state where the outermost layer is polished with time is a toner binder. Is a polycondensed polyester resin, and the polyester resin is a resin formed in the presence of at least one titanium-containing catalyst (a) represented by the following general formula (I) or (II) developing Having at least means,
When mounted on an image forming apparatus, the image forming apparatus constitutes the image forming apparatus described in any one of (1) to (14). Process cartridge.

〔式中、Ｘは炭素数２〜１２のモノもしくはポリアルカノールアミンから１個のＯＨ基のＨを除いた残基であり、ポリアルカノールアミンの他のＯＨ基が、同一のＴｉ原子に直接結合したＯＨ基と分子内で重縮合し環構造を形成していてもよく、他のＴｉ原子に直接結合したＯＨ基と分子間で重縮合し繰り返し構造を形成していてもよい。繰り返し構造を形成する場合の重合度は２〜５である。ＲはＨ、または１〜３個のエーテル結合を含んでいてもよい炭素数１〜８のアルキル基である。ｍは１〜４の整数、ｎは０〜３の整数、ｍとｎの和は４である。ｐは１〜２の整数、ｑは０〜１の整数、ｐとｑの和は２である。ｍまたはｐが２以上の場合、それぞれのＸは同一であっても異なっていてもよい。］」。

[Wherein X is a residue obtained by removing H of one OH group from a mono- or polyalkanolamine having 2 to 12 carbon atoms, and other OH groups of polyalkanolamine are directly bonded to the same Ti atom. The OH group may be polycondensed in the molecule to form a ring structure, or the OH group directly bonded to another Ti atom may be polycondensed between the molecules to form a repeating structure. The degree of polymerization in the case of forming a repeating structure is 2-5. R is H or an alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds. m is an integer of 1 to 4, n is an integer of 0 to 3, and the sum of m and n is 4. p is an integer of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. When m or p is 2 or more, each X may be the same or different. ] "

By the above means, the image forming apparatus of the present invention can reduce the coefficient of friction on the surface of the photoreceptor, and can maintain a state in which the coefficient of friction on the surface of the photoreceptor is reduced even if it is used repeatedly for a long period of time. Good cleaning properties can be maintained over a long period of time.
Further, by properly polishing the photoreceptor surface layer, toner filming on the photoreceptor surface can be suppressed over a long period of time, and a good image can be output.

Hereinafter, embodiments of the present invention will be described.
In the electrophotographic photoreceptor, the outermost layer contains fluororesin fine particles, and the fluororesin fine particles in the outermost layer film are primary particles and secondary particles formed by aggregation of a plurality of primary particles (the surface When the average diameter (of the projected image of the exposed part) is defined as D, the outermost layer is polished at the initial time and the total of the ratio of the (projected) area ratio of the particles in the range of 0.15 ≦ D ≦ 3 μm to the surface. It is good to maintain 10% to 60% at all times even if it is in the state.

Here, the average diameter of the projected image refers to a particle or an aggregate of particles seen when the surface of the outermost layer is observed from a substantially vertical direction as one particle. It is an average value measured in degrees.
An electrophotographic photosensitive member having an outermost layer having such a structure maintains a uniform surface with a very small coefficient of friction on the surface of the photosensitive member by uniformly presenting fluororesin fine particles of a suitable size within a suitable range. Therefore, good cleaning properties can be maintained.

Although the reason is not clearly understood, the following can be considered.
When the average diameter of the primary particles and secondary particles formed by agglomerating a plurality of primary particles (and the projected image of the portion exposed on the surface) is D, the range is 0.15 ≦ D ≦ 3 μm. As the case where the sum of the area ratio (projected) of the particles on the surface is smaller than 10% with respect to the surface of the coating film, the following forms can be considered.

As a first form, the content of fluororesin fine particles in the surface layer is small.
As a second form, most of the fluororesin fine particles (including secondary particles) exposed on the surface are smaller than 0.15 μm.
In the third form, most of the fluororesin fine particles exposed on the surface are larger than 3 μm.
In the first embodiment, as described above, since the low friction coefficient of the surface cannot be maintained in repeated use, there is a possibility that cleaning failure or the like will be caused.
In the second mode, since the average diameter of the exposed portion of the coating film surface is less than 0.15 μm and the coating film surface is dispersed with only very small fluororesin particles, it has an effect on reducing the friction coefficient. Becomes insufficient, resulting in poor cleaning. That is, when the mechanism that the toner is improved in slip cleaning property by setting the photosensitive member surface to have a low coefficient of friction is considered, the area where the primary particles and secondary particles of the fluororesin fine particles are in contact with the toner is reduced. For this reason, it is considered that the effect that the toner slides on the surface of the photosensitive member is halved, resulting in poor cleaning.
Further, in the third embodiment, since a large number of particles larger than 3 μm are exposed on the surface, the surface roughness becomes large as described above, causing cleaning failure, or scattering of laser light to cause electrostatic latent images. It is considered that abnormal images are generated due to deterioration of sharpness of the image, decrease in potential contrast, and the like.

Next, as the form in which more than 60% of the particles in the above-mentioned range are present, the following form can be considered.
The first form is when the content of fluorine fine particles in the outermost layer is large.
The second form is a case where fluorine fine particles are unevenly distributed near the surface.
In the first embodiment, the binder resin content is inevitably reduced, so that the mechanical strength of the outermost layer is weakened and the wear resistance is lowered. In general, fluororesins are known to have low mechanical strength and low wear resistance. Photoreceptors with such a coating surface are highly worn, resulting in early image degradation. There is a risk of doing.
In the second mode, the friction coefficient is initially small in repeated use, but the area ratio of the fluororesin fine particles exposed on the surface decreases as wear progresses, so the friction coefficient increases, and eventually cleaning failure, etc. Invite a bug.

Accordingly, as shown in the present invention, the average of the primary particles and the secondary particles formed by agglomerating a plurality of primary particles in the outermost layer film (the projection image of the portion exposed on the surface) When the diameter is D, it is essential that the total ratio of the projected (projected) area of the particles in the range of 0.15 ≦ D ≦ 3 μm is 10% to 60%.
Furthermore, in the present invention, it is recommended that the outermost surface of the photoconductor is appropriately polished with inorganic fine particles added to the toner in order to suppress the filming of the toner on the surface of the photoconductor. However, it is preferable that the total area ratio of the fluororesin fine particles in the range of 0.15 ≦ D ≦ 3 μm is always maintained at 10% to 60%. This makes it possible to maintain good cleaning properties even if polishing with inorganic fine particles added to the toner progresses over time.

In the present invention, the average diameter D of the primary particles and secondary particles formed by agglomerating a plurality of primary particles (in the projected image of the portion exposed on the surface) is 0.2 ≦ D ≦ 1. In a more preferred embodiment, the total ratio of projected (projected) areas of the particles in the range of .5 μm always maintains 10% to 60% even when the outermost layer is polished at the initial stage and over time. It is included as one.
This is because D is in the above range where the size is appropriate, and the ratio of the surface is also in the above range, so that the surface of the photoreceptor is more uniformly reduced in friction coefficient, and the above-mentioned problems are solved. Further, it is considered that the effect of reducing the surface roughness becomes larger.
Further, in the present invention, the outermost surface of the photoconductor is preferably properly polished with inorganic fine particles added to the toner in order to suppress the toner filming on the surface of the photoconductor. However, it is preferable that the total area ratio of the fluororesin fine particles in the range of 0.2 ≦ D ≦ 1.5 μm is always maintained at 10% to 60%. As a result, even if the polishing with the inorganic fine particles added to the toner progresses over time, the above-mentioned problems can be solved and the effect of reducing the surface roughness can be maintained.

  Furthermore, in this invention, it is included as one of the more preferable aspects that fluororesin microparticles | fine-particles contained in outermost layer are 20 vol%-70 vol%.

  Further, the outermost layer in the present invention includes a protective layer on the photosensitive layer and the photosensitive layer itself without the protective layer. In the present invention, the photosensitive layer includes at least a charge generation material and a charge transport material. More preferably, the protective layer is a layer containing at least a binder resin and fluororesin fine particles. This is because the functional layer is separated into a photosensitive layer having a function as an electrophotographic photosensitive member and a protective layer having a low coefficient of friction function, so that the side effect of the electrical characteristics of the photosensitive member is small and the friction coefficient is good. A photoreceptor is provided.

Furthermore, in the present invention, the outermost layer includes at least a charge transport material as a more preferable embodiment.
In particular, when the protective layer is the outermost layer, inclusion of the charge transport material allows smooth charge transfer and suppresses problems such as an increase in residual potential.

In addition, according to the present invention, there is provided an image forming apparatus comprising a contact member that contacts and rubs at least the surface of the electrophotographic photosensitive member while pressing the surface of the electrophotographic photosensitive member. There are provided an image forming apparatus and an image forming method having a configuration in which the fluororesin fine particles contained therein are extended and covered on the surface of the outermost layer by the contact member.
As a result, the surface area with a low coefficient of friction is increased, so that the effect of reducing the coefficient of friction is remarkably improved, and the cleaning property is remarkably increased. Although this effect is not clearly understood, the following mechanism is conceivable.
When the contact member rubs the outermost layer on which the fluororesin fine particles are exposed, the exposed portion of the fluororesin fine particles extends in the rubbing direction to cover the surface of the photoreceptor without the fluororesin fine particles. At this time, as the surface of the outermost layer of the electrophotographic photosensitive member of the present invention, particles having a suitable size are present almost uniformly in a suitable range, so that the content of the fluororesin fine particles is not increased. Since the surface in which the fine particles are not present can be coated over almost the entire region, the friction coefficient can be expressed almost uniformly over the entire surface of the photoreceptor surface. Furthermore, even if the outermost layer is polished, the internal fluororesin fine particles are precipitated, so that it is possible to maintain a surface with a low coefficient of friction over a long period of time, and a high level of cleaning performance can be maintained.
When the surface of the photoreceptor rubbed with the SEM image was observed, the appearance of the fluororesin covering the surface due to the above phenomenon was observed.

Furthermore, as described above, the present invention includes, as one of the preferred embodiments, that the outermost layer of the photoreceptor is appropriately polished by the inorganic fine particles added to the toner and the outermost layer is always refreshed. Thereby, it is thought that the effect which suppresses the filming to the surface of the outermost layer over a long period of time is acquired.
The inorganic fine particles added to the toner initially exist in a state of adhering to the surface of the base, but are gradually embedded in the toner base due to stress due to stirring with the carrier and passing through the doctor of the developing unit over time. End up. If the inorganic fine particles are embedded in the toner base, the effect of polishing the outermost surface of the photoreceptor by the inorganic fine particles cannot be obtained, and filming on the outermost surface is promoted.
However, as in the present invention, the toner binder comprises a polycondensation polyester resin, and the polyester resin is formed in the presence of at least one titanium-containing catalyst (a) represented by the general formula (I) or (II). It was confirmed that by using the resin thus formed, the inorganic fine particles are less likely to be embedded in the toner base material over time, and exhibit a polishing effect.

Hereinafter, the electrophotographic photoreceptor of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of an electrophotographic photosensitive member of the present invention, showing an electrophotographic photosensitive member having a structure in which a photosensitive layer is provided on a conductive support. 2, 3 and 4 show other examples of the structure of the electrophotographic photosensitive member according to the present invention. FIG. 2 shows a function-separated type electrophotographic photoreceptor in which the photosensitive layer is composed of a charge generation layer (CGL) and a charge transport layer (CTL). FIG. 3 shows a conductive support and a function-separated type electrophotographic photoreceptor. An electrophotographic photosensitive member is shown in which an undercoat layer is inserted between CGL and CTL of the photosensitive layer. FIG. 4 shows an electrophotographic photosensitive member in which a protective layer is further formed on the photosensitive layer of the type shown in FIG. The electrophotographic photosensitive member according to the present invention may have other layers other than the above as long as it has at least a photosensitive layer on a conductive support, and the type of the photosensitive layer. May be combined arbitrarily.

As the conductive support used in the electrophotographic photosensitive member in the present invention, a conductor or an insulator subjected to a conductive treatment, for example, a metal such as Al, Ni, Fe, Cu, Au, or an alloy thereof, polyester, A thin film made of a metal such as Al, Ag, Au or a conductive material such as In ₂ O ₃ or SnO ₂ on an insulating substrate such as polycarbonate, polyimide or glass, carbon black, graphite, Al, A resin substrate obtained by uniformly dispersing a metal powder such as Cu or Ni, conductive glass powder or the like and imparting conductivity to the resin, paper subjected to conductive treatment, or the like can be used. The shape of the conductive support is not particularly limited, and any of a plate shape, a drum shape, and a belt shape can be used. However, when a belt-like support is used, it is necessary to provide a driving roller and a driven roller inside. While the equipment is complicated and large, there are advantages such as increased flexibility in layout. However, when forming a protective layer, there is a possibility that cracks called cracks may occur on the surface due to insufficient flexibility of the protective layer, which may cause granular background stains. It is done. For this reason, a drum-like member having high rigidity is preferably used as the support.

If necessary, an undercoat layer may be provided between the conductive support and the photosensitive layer. Such an undercoat layer is provided for the purpose of improving adhesion, preventing moire, improving the coatability of the upper layer, and reducing residual potential. The undercoat layer generally contains a resin as a main component, but these resins are resins having high solubility resistance to general organic solvents in consideration of applying a photosensitive layer thereon with a solvent. It is desirable to be. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resins, alkyd-melamine resins, and epoxy resins. Examples thereof include curable resins that form a three-dimensional network structure. Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added. These undercoat layers can be formed by a common coating method using an appropriate solvent.
Further, as the undercoat layer, a metal oxide layer formed by using, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful.
In addition, as the undercoat layer, an anodized layer of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), or an inorganic material such as SnO ₂ , TiO ₂ , ITO, or CeO ₂ is used. It may be provided by a vacuum thin film manufacturing method.
The thickness of the undercoat layer is suitably about 0.1 to 5 μm.

  As the kind of the photosensitive layer used in the electrophotographic photosensitive member of the present invention, any of Se type, OPC type and the like can be applied. Examples of inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds. In particular, environmentally friendly and inexpensive OPC is good. Of these, the OPC system will be briefly described below.

The photosensitive layer in the present invention may be either a single layer type or a laminated type, but here, a laminated type will be described. First, the charge generation layer will be described.
The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin may be used as necessary. As the charge generation material, inorganic materials and organic materials can be used.

  Examples of inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds.

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Polyacrylamide or the like is used. These binder resins can be used alone or as a mixture of two or more.
Moreover, you may add a charge transport substance as needed. In addition to the binder resin described above, a polymer charge transporting material is also preferably used as the binder resin for the charge generation layer.

As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be largely mentioned.
Examples of the former method include a glow discharge polymerization method, a vacuum deposition method, a CVD method, a sputtering method, a reactive sputtering method, an ion plating method, and an accelerated ion injection method. This vacuum thin film manufacturing method can satisfactorily form the inorganic material or organic material described above.
Further, in order to provide the charge generation layer by the latter casting method, a ball mill using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone together with a binder resin, if necessary, the inorganic or organic charge generation material described above, It can be formed by dispersing with an attritor, sand mill or the like, and applying the solution after diluting the dispersion appropriately. The application can be performed using a commonly used method such as a dip coating method, spray coating, or bead coating method.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

  The charge transport layer is a layer intended to hold a charged charge and to couple the charge generated and separated in the charge generation layer by exposure to the charged charge that has been held. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

  The charge transport layer for satisfying these requirements is composed of a charge transport material and a binder resin used as necessary. Such a charge transport layer can be formed by dissolving or dispersing these charge transport materials and a binder resin in an appropriate solvent, and applying and drying them. If necessary, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent can be added to the charge transport layer in addition to the charge transport material and the binder resin.

Examples of the charge transport material include a hole transport material and an electron transport material.
Examples of the electron transport material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2, 4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophene-4-one, 1,3,7-tri Examples thereof include electron accepting substances such as nitrodibenzothiophene-5,5-dioxide. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline , Phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like. These hole transport materials can be used alone or as a mixture of two or more.

Further, the polymer charge transporting substance may have the following structure.
(A) Polymer having carbazole ring For example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-4-175337 And the compounds described in JP-A-4-183719 and JP-A-6-234841.

(B) Polymer having a hydrazone structure For example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, JP-A-1-134456 179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, JP-A-6-234840, and the like. Is done.

(C) Polysilylene polymer For example, JP-A 63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, JP-A-4-264132, Examples thereof include compounds described in Kaihei 4-264133 and JP-A-4-289867.

(D) Polymer having a triarylamine structure For example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, JP-A-2- Examples thereof include compounds described in JP-A-304456, JP-A-4-133305, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.

(E) Other polymers For example, formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-150749, JP-A-6-234836, JP-A-6-234837 The described compounds and the like are exemplified.

  The polymer having an electron donating group used in the present invention is not limited to the above-mentioned polymer, but also a copolymer of a known monomer, a block polymer, a graft polymer, a star polymer, It is also possible to use a cross-linked polymer having an electron donating group as disclosed in JP-A-3-109406.

  Further, examples of polycarbonates, polyurethanes, polyesters, and polyethers having a triarylamine structure that are further useful as the polymer charge transporting material used in the present invention include, for example, JP-A 64-1728 and JP-A 64- 13061, JP 64-19049, JP 4-11627, JP 4-225014, JP 4-230767, JP 4-320420, JP 5-232727 JP, 7-56374, JP 9-127713, JP 9-222740, JP 9-265197, JP 9-211877, JP 9-304956. And the like.

  Furthermore, as a binder resin that can be used in combination with the charge transport layer, for example, polycarbonate, polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenol resin, epoxy resin, polyurethane, polyvinylidene chloride, alkyd resin, Silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl formal, polyacrylate, polyacrylamide, phenoxy resin, and the like are used. These binder resins can be used alone or as a mixture of two or more.

  The film thickness of the charge transport layer is suitably about 5 to 100 μm. However, due to the recent demand for higher image quality, it has been attempted to make the charge transport layer thinner and achieve higher image quality of 1200 dpi or more. For this purpose, a thickness of about 5 to 30 μm is more preferable.

Additives such as other antioxidants and plasticizers used for rubbers, plastics, fats and the like may be added to the charge transport layer in the present invention.
Furthermore, a leveling agent may be added in the charge transport layer. Examples of such leveling agents include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain, and the amount used is 100 parts by weight of binder resin. From 0 to 1 part by weight is appropriate.

  As the coating method, a commonly used method such as a dip coating method, spray coating, or bead coating method can be used.

Furthermore, when the charge transport layer is the outermost layer of the photoreceptor, at least the charge transport layer contains fluororesin fine particles.
When the fluororesin fine particles are contained in the charge transport layer, it is preferable to increase the content in the vicinity of the surface of the charge transport layer in order to obtain the effect of reducing the friction coefficient more efficiently. That is, it is the fluororesin fine particles exposed on the surface of the photoreceptor that exerts the effect of reducing the friction coefficient, and the film thickness that can no longer function as an electrophotographic photoreceptor due to wear of the charge transport layer due to repeated use. The fluororesin fine particles contained therein may be wasted and may adversely affect the electrophotographic characteristics of the photoreceptor. As a method for producing an electrophotographic photosensitive member containing a large amount of fluororesin fine particles in the vicinity of the surface of the charge transport layer, for example, after applying a coating liquid for forming a charge transport layer that does not contain fluororesin fine particles, A method such as applying the applied charge transport layer forming coating solution is conceivable.

  For example, specifically, a first charge transport layer is first formed on a charge generation layer using a coating liquid for forming a charge transport layer that does not contain fluororesin fine particles, and the content of fluororesin fine particles is formed thereon. A charge transport layer containing a large amount of fluororesin fine particles on the surface can be formed by forming the second charge transport layer using a coating liquid for forming a charge transport layer having a solid content ratio of 40 vol% and drying.

As the coating method, known methods such as dip coating and spray coating can be considered.
The content of the fluororesin fine particles is preferably 20 vol% to 70 vol%, and needs to be dispersed and exposed on the surface so as to be in the above range of the present invention. If the content is less than 20 vol%, the projected area ratio of the fine particles exposed on the surface may be reduced, the sustainability of the low friction coefficient may be reduced, and if the content is greater than 70 vol%, It is considered that the binder resin content is inevitably reduced and the mechanical strength of the coating film is lowered.
Moreover, it is not preferable that the primary particle diameter of the fluororesin fine particles is too large or too small to satisfy the average diameter of the preferred primary particles and secondary particles of the present invention. Specifically, those having an average particle diameter in the range of 0.1 to 0.3 μm are preferable.

Next, observation by a scanning electron microscope (SEM) will be described as an example of a method for calculating the average diameter and area ratio of the projected image of the portion where the fluororesin fine particles of the present invention are exposed on the surface.
The surface of the electrophotographic photosensitive member in which the fluororesin microparticles are dispersed is photographed by SEM, and the fluororesin microparticle image displayed in the obtained SEM image is analyzed by using an image analyzer, so that the average diameter of the microparticles, The number, area ratio, etc. can be obtained. At this time, since the image obtained as the SEM image is projected from a substantially vertical direction on the surface, the image of the fluororesin fine particles displayed is also a projected image in the vertical direction. Here, the average diameter of the projected image is an average value obtained by measuring the inner diameter passing through the center of gravity in increments of 2 degrees with respect to a projected image in which particles or aggregates of particles seen when observed are regarded as one particle.

  The image analysis device is capable of binaryly distinguishing the projection image of the fluororesin fine particles from the surrounding binder resin, and the condition that secondary particles in which a plurality of primary particles are aggregated can be approximated as large particles. It is necessary to be able to select. Furthermore, it is necessary to provide a program that can calculate at least the average diameter and the area ratio for each projected image of the fluororesin fine particles. As such an image analysis device, a computer into which image analysis software Image-Pro Plus (manufactured by Planetron) is introduced, a dedicated device such as a high-detail image analysis system IP-1000 (manufactured by Asahi Engineering), or the like is used. Here, it is a value measured using a computer into which image analysis software Image-Pro Plus (manufactured by Planetron) is introduced.

When the acceleration voltage is high, the SEM image may be obtained as image information up to the inside of the vicinity of the surface. In a system in which fluorine fine particles are dispersed in a binder resin, if the acceleration voltage is high, it may be observed through the fluororesin fine particles that are not exposed on the surface and are present near the surface. It is necessary to adjust so that the fluororesin fine particles exposed on the surface are projected.
For example, when a field emission scanning electron microscope S-4200 (manufactured by Hitachi, Ltd.) is used as the SEM, the acceleration voltage is preferably about 2 kv to 6 kv, which depends on the device and the material of the photoconductor. It is necessary to adjust accordingly.
The surface SEM image obtained in this way is taken into image analysis software, and the average diameter and area ratio of the individual fluororesin fine particles counted in the observation range are calculated. Can be observed.

In addition, when the charge transport layer is the outermost layer, the photoreceptor of the present invention may contain a filler other than the fluororesin fine particles in the charge transport layer.
Filler materials include organic filler materials and inorganic filler materials. Examples of the organic filler material include silicone resin powder and a-carbon powder, and examples of the inorganic filler material include metal powder such as copper, tin, aluminum, and indium, silica, tin oxide, zinc oxide, titanium oxide, Metal oxides such as alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide, tin oxide doped with antimony, tin-doped indium oxide, metal fluorides such as tin fluoride, calcium fluoride, aluminum fluoride, Examples thereof include inorganic materials such as potassium titanate and boron nitride.

Since the filler made of an inorganic material has a higher hardness than the filler made of an organic material, the wear resistance of the outermost layer of the photoreceptor can be further improved. However, generally, when the wear resistance of the latent image carrier is improved, the surface portion of the latent image carrier is hardly worn, but the surface portion is caused by reactive gases such as ozone and NOx generated during charging. It is known that the resistance is lowered, the electrostatic charge on the surface portion is gradually not retained, and the electrostatic charge moves toward the surface. As a result, the electrostatic latent image is blurred and an abnormal image called image blur or image flow that occurs when the electrostatic latent image is developed with toner or the like occurs. Therefore, the filler used in the present invention preferably has a high resistance of 10 ¹⁰ Ωcm or more. By using such a filler, the resistance reduction of the outermost surface of the photoreceptor can be suppressed, and the occurrence of the abnormal image can be significantly suppressed.

Among these fillers, silica, titanium oxide, and alumina can be used effectively. In addition, since these filler materials are cheaper and easier to obtain than other metal oxide fine particles, it is possible to reduce the manufacturing cost of the photoreceptor.
Among them, α-type alumina, which has a hexagonal close-packed structure with high insulation, high thermal stability, and high wear resistance, is particularly useful in terms of suppressing image blur and improving wear resistance. . Such filler materials may be used alone or in admixture of two or more.

These filler materials can be dispersed by using an appropriate disperser together with a charge transport material, a binder resin, a solvent, and the like. The average primary particle size of the filler is 0.05 to 1.0 μm, preferably 0.1 to 0.3 μm.
If the average primary particle size of the filler is too smaller than 0.05 μm, the wear resistance may be insufficient. On the other hand, if the average primary particle diameter of the filler is too larger than 1.0 μm, the optical writing light applied to the latent image carrier is scattered by the filler, resulting in a decrease in transmittance, resulting in image blurring and character thickening. Sometimes.

  The filler concentration in the surface layer varies depending on the type of filler used and also on the electrophotographic process conditions using the photoreceptor, but is preferably 5 to 60% by weight. In addition, these fillers can be contained in the entire charge transport layer, but since the exposed area potential may be high, the outermost surface side of the charge transport layer has the highest filler content, and the conductive support It is preferable to provide a structure in which a filler concentration gradient is provided so that the body side is lowered, or a plurality of charge transport layers are provided so that the filler concentration is sequentially increased from the conductive support side to the surface side.

Next, the case where the photosensitive layer has a single layer structure will be described.
When a single-layer photosensitive layer is provided by a casting method, in many cases, such a single-layer photosensitive layer is obtained by dissolving or dispersing a charge generating substance, a low molecular weight molecule, and a polymer charge transporting substance in an appropriate solvent, and applying and drying the solution. Can be formed. As the charge generating substance and the charge transporting substance, the materials described above can be used.
In addition, a plasticizer can be added to the single-layer photosensitive layer as necessary. Furthermore, as the binder resin that can be used as necessary, the binder resins mentioned above for the charge transport layer can be used as they are. In addition, the binder resin mentioned in the charge generation layer may be mixed and used.
Further, when the single-layer photosensitive layer is the outermost layer of the photoreceptor, at least the single-layer photosensitive layer contains fluororesin fine particles, and the fluororesin fine particles are present in the dispersed state of the present invention.
As a result, the same effect as that of the charge transport layer described above can be obtained.
Further, as in the case of the above-described charge transport layer, it is preferable to increase the content of the fluororesin fine particles in the vicinity of the surface, and the same production method can be used for this method.
The thickness of the photosensitive layer of the single-layer photoreceptor is suitably about 5 to 100 μm.

  In the photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer. Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane, polychlorinated Examples thereof include resins such as vinyl, polyvinylidene chloride, and epoxy resin.

  Moreover, when using a protective layer, since a protective layer becomes the outermost layer, the fluororesin fine particle is contained in the protective layer. The protective layer is mainly intended to improve wear resistance. In the present invention, by containing the fluororesin fine particles in a suitable dispersed state, the low friction coefficient is maintained even after repeated use over a long period of time, and the wear resistance is improved. Furthermore, since the protective layer is provided on the photosensitive layer with a relatively small film thickness, the influence on the electrical characteristics of the photoreceptor is relatively small, and the content is higher than that in the case where the charge transport layer contains fluororesin fine particles. There is an advantage that it can be made large, or it can be functionally separated from the charge transport layer using a formulation specializing in low coefficient of friction and wear resistance.

  Further, the protective layer may contain a filler material in order to impart further wear resistance. As the filler, those described above can be used, and these filler materials can be used alone or in combination of two or more.

In addition, the inclusion of a charge transport material in the protective layer is very useful for suppressing the electrical characteristics of the photoreceptor, in particular, the deterioration of photosensitivity during repeated use and the increase in residual potential. This is considered to be because the charge can be smoothly transferred to the surface of the photoreceptor by providing the protective layer also with charge transportability. As such a charge transporting substance, the charge transporting substance used in the charge transporting layer mentioned above can be used.
Furthermore, various additives may be added to the protective layer of the electrophotographic photoreceptor according to the present invention for the purpose of improving adhesiveness, smoothness, and chemical stability.

The protective layer according to the present invention is formed on the photosensitive layer using a conventional coating method such as dip coating, spray coating, blade coating, knife coating or the like. In particular, dip coating and spray coating are advantageous in terms of mass productivity and coating film quality.
However, since the dispersion state of the fluororesin fine particles on the surface of the photoreceptor also changes depending on various conditions in coating, the setting of conditions for coating is very important.
For example, in spray coating, first, the coating liquid conditions include solid content concentration, in the case of a mixed solvent, its type and mixing ratio, and the spray device conditions include the coating liquid discharge rate, fog The air pressure, the distance between the spray tip and the surface of the application part, the moving speed of the surface of the application object, the number of times of overcoating and the like can be mentioned. For example, when forming a protective layer with a desired film thickness by reducing the discharge amount of the coating liquid and increasing the number of overcoats, the coating film is formed in a dry state, and conversely, the discharge amount is increased. If the number of overcoating is reduced, a coating film is formed in a wetter state. Thus, even if it takes one state of the coating film under coating, it is thought that it influences the state of the surface fluororesin fine particles. Therefore, it is necessary to study various coating conditions and grasp a suitable range so that the surface fluororesin fine particles are in a state as in the present invention.
The thickness of the protective layer thus obtained is suitably in the range of 0.1 to 15 μm, more preferably 1 to 10 μm.

  On the other hand, in the toner used in the present invention, the titanium-containing catalyst (a) is a compound represented by the general formula (I) or (II) as described above, and two or more of them may be used in combination.

  In the general formulas (I) and (II), X is a residue obtained by removing the H atom of one OH group from a mono- or polyalkanolamine having 2 to 12 carbon atoms. The total number of secondary and tertiary amino groups is usually 1 to 2, preferably 1. Examples of the monoalkanolamine include ethanolamine and propanolamine. Polyalkanolamines include dialkanolamines (such as diethanolamine, N-methyldiethanolamine, and N-butyldiethanolamine), trialkanolamines (such as triethanolamine, and tripropanolamine), and tetraalkanolamines (N, N, N). ', N'-tetrahydroxyethylethylenediamine and the like).

  In the case of polyalkanolamine, at least one OH group is present in addition to the OH group that is a residue other than H used to form a Ti—O—C bond with a Ti atom, and this is the same Ti atom. A ring structure may be formed by polycondensation with a directly bonded OH group in the molecule, or a repeating structure may be formed by polycondensation between molecules with an OH group directly bonded to another Ti atom. The degree of polymerization in the case of forming a repeating structure is 2-5. When the degree of polymerization is 6 or more, the catalytic activity is lowered and the oligomer component is increased, which causes deterioration of toner blocking properties.

Preferred as X are residues of dialkanolamine (particularly diethanolamine) and residues of trialkanolamine (particularly triethanolamine), and particularly preferred are residues of triethanolamine.
R is H or an alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds. Specific examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, n-hexyl group, n-octyl group, β-methoxyethyl group, And β-ethoxyethyl group. Of these R, H and an alkyl group having 1 to 4 carbon atoms not containing an ether bond are preferable, and H, an ethyl group, and an isopropyl group are more preferable.

In general formula (I), m is an integer of 1-4, Preferably it is an integer of 1-3. n is an integer of 0 to 3, preferably an integer of 1 to 3. The sum of m and n is 4.
In general formula (II), p is an integer of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. When m or p is 2 or more, a plurality of Xs may be the same or different, but are preferably all the same.

  Specific examples of the titanium-containing catalyst (a) in the present invention represented by the general formula (I) include titanium dihydroxybis (triethanolaminate), titanium trihydroxytriethanolaminate, titanium dihydroxybis ( Diethanolaminate), titanium dihydroxybis (monoethanolamate), titanium dihydroxybis (monopropanolamate), titanium dihydroxybis (N-methyldiethanolamate), titanium dihydroxybis (N-butyldiethanolamate), tetrahydroxytitanium and Reaction products with N, N, N ′, N′-tetrahydroxyethylethylenediamine, and intramolecular or intermolecular polycondensates thereof may be mentioned.

  Specific examples of those represented by the general formula (II) include titanyl bis (triethanolaminate), titanyl bis (diethanolaminate), titanyl bis (monoethanolamate), titanyl hydroxyethanolamate, titanylhydroxytriethanolamate, titanyl. Examples include ethoxytriethanolamate, titanyl isopropoxytriethanolamate, and intramolecular or intermolecular polycondensates thereof.

Among these, preferred are titanium dihydroxybis (triethanolamate), titanium dihydroxybis (diethanolamate), titanylbis (triethanolamate), polycondensates thereof, and combinations thereof, and more preferably , Titanium dihydroxybis (triethanolaminate), its polycondensate, in particular titanium dihydroxybis (triethanolamate).
These titanium-containing catalysts (a) can be stably obtained, for example, by reacting commercially available titanium dialkoxybis (alcohol aminate; manufactured by Dupont, etc.) at 70 to 90 ° C. in the presence of water. it can.

  As the polycondensation polyester resin constituting the toner binder of the present invention, a polyester resin (AX), which is a polycondensate of a polyol and a polycarboxylic acid, (AX) and a modification obtained by further reacting a polyepoxide (c) or the like A polyester resin (AY) etc. are mentioned. (AX), (AY) and the like may be used alone or in combination of two or more.

  Examples of the polyol include a diol (g) and a trivalent or higher polyol (h), and examples of the polycarboxylic acid include a dicarboxylic acid (i) and a trivalent or higher polycarboxylic acid (j). You may use together.

Examples of the polyester resins (AX) and (AY) include the following, and these may be used in combination.
(AX1): Linear polyester resin using (g) and (i) (AX2): Non-linear polyester resin using (h) and / or (j) together with (g) and (i) ( AY1): Modified polyester resin obtained by reacting (AX2) with (c)

As the diol (g), those having a hydroxyl value of 180 to 1900 (mg KOH / g, the same shall apply hereinafter) are preferable. Specifically, alkylene glycol having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, etc.); 4 to 36 alkylene ether glycols (such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polypropylene glycol); alicyclic diols having 6 to 36 carbon atoms (1,4-cyclohexanedimethanol and hydrogen) Added bisphenol A and the like; an alkylene oxide having 2 to 4 carbon atoms of the above alicyclic diol [ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO) and putylene oxide (hereinafter referred to as BO) Adducts (addition mole number 1-30); adducts (additions) of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) having 2 to 4 carbon atoms alkylene oxides (EO, PO, BO, etc.) Mole number 2-30) etc. are mentioned.
Of these, preferred are alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols, and combinations thereof. Particularly preferred are alkylene oxide adducts of bisphenols, alkylene glycols having 2 to 4 carbon atoms. And a combination of two or more of these.
In the above and below, the hydroxyl value and the acid value are measured by the methods specified in JIS K 0070.

The trivalent or higher (3 to 8 or higher) polyol (h) is preferably a hydroxyl value of 150 to 1900. Specifically, an aliphatic polyhydric alcohol having 3 to 36 or more carbon atoms having 3 to 8 or more carbon atoms (an alkane polyol and an intramolecular or intermolecular dehydrate thereof such as glycerin, triethylolethane, trimethylolpropane, pentane). Erythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol; saccharides and derivatives thereof such as sucrose and methyl glucoside; ) Adduct (addition mole number 1-30); Trisphenols (trisphenol PA etc.) C2-C4 alkylene oxide (EO, PO, BO etc.) adduct (addition mole number 2-30); Novolak Resin (phenol novolac and cresol novola Click like: average polymerization degree of 3 to 60 alkylene oxide (EO 2-4 carbon atoms), PO, BO, etc.) adducts (added mole number 2 to 30) are exemplified.
Among these, preferred are 3 to 8 or higher aliphatic polyhydric alcohols and alkylene oxide adducts of novolac resins (addition mole number: 2 to 30), and particularly preferred are alkylene oxide adducts of novolak resins. It is.

  As the dicarboxylic acid (i), those having an acid value of 180 to 1250 (mg KOH / g, the same applies hereinafter) are preferable. Specifically, alkane dicarboxylic acids having 4 to 36 carbon atoms (such as succinic acid, adipic acid, and sebacic acid) and alkenyl succinic acids (such as dodecenyl succinic acid); alicyclic dicarboxylic acids having 4 to 36 carbon atoms [dimer acid] (Dimerized linoleic acid) etc.]; C4-C36 alkene dicarboxylic acid (maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.); C8-36 aromatic dicarboxylic acid (phthalic acid, isophthalic acid) , Terephthalic acid, and naphthalenedicarboxylic acid). Of these, preferred are alkene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. As (i), acid anhydrides or lower alkyl (carbon number 1 to 4) esters (methyl ester, ethyl ester, isopropyl ester, etc.) described above may be used.

  The trivalent or higher (3 to 6 or higher) polycarboxylic acid (j) preferably has an acid value of 150 to 1250 mg. Specifically, an aromatic polycarboxylic acid having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, etc.); vinyl polymer of unsaturated carboxylic acid [number average molecular weight (hereinafter referred to as Mn, gel permeation chromatography) (By GPC): 450-10000] (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, α-olefin / maleic acid copolymer, styrene / fumaric acid copolymer, etc.), and the like. . Among these, preferred are aromatic polycarboxylic acids having 9 to 20 carbon atoms, and particularly preferred are trimellitic acid and pyromellitic acid. As the trivalent or higher polycarboxylic acid (j), acid anhydrides or lower alkyl (1 to 4 carbon atoms) esters (methyl ester, ethyl ester, isopropyl ester, etc.) described above may be used.

  Further, together with (g), (h), (i) and (j), an aliphatic or aromatic hydroxycarboxylic acid (k) having 4 to 20 carbon atoms and a lactone (l) having 6 to 12 carbon atoms are copolymerized. You can also

  Examples of the hydroxycarboxylic acid (k) include hydroxystearic acid and hydrogenated castor oil fatty acid. Examples of the lactone (l) include caprolactone.

Examples of the polyepoxide (c) include polyglycidyl ether [ethylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, phenol novolak ( Average polymerization degree 3 to 60) glycidyl etherified compound, etc.]; diene oxide (pentadiene dioxide, hexadiene dioxide, etc.) and the like. Among these, polyglycidyl ether is preferable, and ethylene glycol diglycidyl ether and bisphenol A diglycidyl ether are more preferable.
The number of epoxy groups per molecule of (c) is preferably 2-8, more preferably 2-6, and particularly preferably 2-4.
The epoxy equivalent of (c) is preferably 50 to 500. The lower limit is more preferably 70, particularly preferably 80, and the upper limit is more preferably 300, particularly preferably 200. When the number of epoxy groups and the epoxy equivalent are within the above ranges, both developability and fixability are good. It is more preferable if the above-mentioned ranges of the number of epoxy groups per molecule and the epoxy equivalent are satisfied at the same time.

  The reaction ratio of the polyol and the polycarboxylic acid is preferably 2/1 to 1/2, more preferably 1.5 / 1, as an equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. ˜1 / 1.3, particularly preferably 1.3 / 1 to 1 / 1.2. The types of polyol and polycarboxylic acid to be used are selected in consideration of molecular weight adjustment so that the glass transition point of the polyester toner binder to be finally adjusted is 45 to 85 ° C.

The toner binder is required to have different physical properties for full color and monochrome use, and the design of the polyester resin is also different.
That is, since a high-gloss image is required for full color use, it is necessary to use a low-viscosity binder. However, for monochrome use, gloss is not particularly required, and hot offset properties are important, so a high-elasticity binder is required. is there.
(AX1), (AX2), (AY1) and mixtures thereof are preferred for obtaining a high gloss image useful for a full-color copying machine or the like. In this case, since low viscosity is preferable, the ratio of (h) and / or (j) constituting these polyester resins is such that the sum of the number of moles of (h) and (j) is (g) to Preferably it is 0-20 mol% with respect to the total number of moles of (j), More preferably, it is 0-15 mol%, Especially 0-10 mol%.

  (AX2), (AY1), and mixtures thereof are preferred for obtaining high hot offset resistance useful for monochrome copying machines and the like. In this case, since it is preferable that it is highly elastic, as this polyester resin, what uses both (h) and (j) is especially preferable. The ratio of (h) and (j) is preferably such that the sum of the number of moles of (h) and (j) is 0.1 to 40 mol% with respect to the total number of moles of (g) to (j). More preferably, it is 0.5-25 mol%, especially 1-20 mol%.

In the case of a full-color polyester resin, the temperature (TE) at which the complex viscosity (η *) is 100 Pa · S is preferably 90 to 170 ° C, more preferably 100 to 165 ° C, and particularly 105 to 150 ° C. Sufficient gloss is obtained at 170 ° C. or lower, and heat resistant storage stability is improved at 90 ° C. or higher.
(TE) is, for example, a block after melt-kneading a resin at 130 ° C. and 70 rpm for 30 minutes using a laboratory blast mill, using a commercially available dynamic viscoelasticity measuring device while changing the resin temperature to a complex viscosity ( (η *) is measured.
Further, the tetrahydrofuran (THF) insoluble content of the full-color polyester resin is preferably 10% or less, more preferably 5% or less, from the viewpoint of glossiness.
In the above and the following, “%” means “% by weight” unless otherwise specified.

The THF-insoluble content and the THF-soluble content are obtained by the following method.
About 0.5 g of a sample is precisely weighed into a 200 ml stoppered Meyer flask, 50 ml of THF is added, and the mixture is stirred and refluxed for 3 hours. After cooling, the insoluble matter is filtered off with a glass filter. The value (%) of THF-insoluble matter is calculated from the weight ratio of the resin content on the glass filter after vacuum drying at 80 ° C. for 3 hours and the weight of the sample.
Note that this filtrate is used as a THF soluble component for the molecular weight measurement described later.

In the case of a monochrome polyester resin, from the viewpoint of hot offset resistance, the temperature (TG) at which the storage elastic modulus (G ′) of the polyester resin is 6000 Pa is preferably 130 to 230 ° C., more preferably 140 to 230 ° C., It is 150-230 degreeC especially.
(TG) is, for example, a block after melt-kneading a resin at 130 ° C. and 70 rpm for 30 minutes using a laboratory blast mill, and using a commercially available dynamic viscoelasticity measuring device while changing the resin temperature (storage modulus ( It is obtained by measuring G ′).

  From the viewpoint of low-temperature fixability and heat-resistant storage stability, the temperature (TE) at which the complex viscosity (η *) of the monochrome polyester resin becomes 1000 Pa · S is preferably 80 to 140 ° C., more preferably 90 to 135 ° C. In particular, it is 105 to 130 ° C.

  The monochrome polyester resin preferably contains 2 to 70% of THF-insoluble matter, more preferably 5 to 60%, particularly 10 to 50%. When the THF insoluble content is 2% or more, the hot offset resistance is good, and when it is 70% or less, good low-temperature fixability is obtained.

  The peak top molecular weight (Mp) of the polyester resin is preferably 1000 to 30000, more preferably 1500 to 25000, and particularly 1800 to 20000 for both monochrome and full color applications. When Mp is 1000 or more, heat-resistant storage stability and powder fluidity are good, and when it is 30000 or less, the pulverization property of the toner is improved and the productivity is good.

  When the toner binder (A) comprising the polyester resin of the present invention is used as a toner, the ratio of the component having a molecular weight of 1500 or less in the toner is preferably 1.8% or less, more preferably 1.3% or less. Particularly preferably, it is 1.1% or less. When the ratio of the component having a molecular weight of 1500 or less is 1.8% or less, the storage stability becomes better.

In the above and the following, the ratio of Mp, Mn, and a component having a molecular weight of 1500 or less in the polyester resin or toner is measured for the THF-soluble component using GPC under the following conditions.
Device: Tosoh HCL-8120
Column: TSKgelGMHXL (2)
TSK gelmultiporeHXL-M (nothing)
Measurement temperature: 40 ° C
Sample solution: 0.25% THF solution Injection volume: 100 μl
Detector: Refractive index detector Reference material: Polystyrene The molecular weight showing the maximum peak height on the obtained chromatogram is referred to as peak top molecular weight (Mp). Furthermore, the abundance ratio of low molecular weight substances is evaluated by the ratio of the peak areas when the molecular weight is 1500.

The acid value of the polyester resin is preferably 0.1 to 60, more preferably 0.2 to 50, and particularly preferably 0.5 to 40 for both monochrome and full color applications. When the acid value is in the range of 0.1 to 60, the chargeability is good.
The hydroxyl value of the polyester resin is preferably 1 to 70, more preferably 3 to 60, and particularly preferably 5 to 55 for both monochrome and full color applications. When the acid value is in the range of 1 to 70, the environmental stability is good.
The glass transition point (Tg) of the polyester resin is preferably 40 to 90 ° C., more preferably 50 to 80 ° C., particularly 55 to 75 ° C. for both monochrome and full color applications. When (Tg) is in the range of 40 ° C. to 90 ° C., the heat resistant storage stability and the low temperature fixability are good.
In the above and below, the (Tg) of the polyester resin is measured by a method (DSC method) defined in ASTM D3418-82 using DSC20, SSC / 580 manufactured by Seiko Denshi Kogyo Co., Ltd.

The polyester resin used as the toner binder (A) in the present invention can be produced in the same manner as in the usual polyester production method. For example, the reaction temperature is preferably 150 to 280 ° C, more preferably 160 to 250 ° C, and particularly preferably 170 to 240 ° C in the presence of a titanium-containing catalyst (a) in an inert gas (nitrogen gas or the like) atmosphere. It can be performed by reacting. The reaction time is preferably 30 minutes or longer, particularly 2 to 40 hours from the viewpoint of reliably performing the polycondensation reaction. It is also effective to reduce the pressure (for example, 1 to 50 mmHg) in order to improve the reaction rate at the end of the reaction.
The addition amount of (a) is preferably 0.0001 to 0.8%, more preferably 0.0002 to 0.6%, particularly preferably 0.0002 to 0.6%, based on the weight of the polymer obtained from the viewpoint of polymerization activity and the like. Preferably it is 0.0015 to 0.55%.
In addition, other esterification catalysts can be used in combination as long as the catalytic effect of (a) is not impaired. Examples of other esterification catalysts include tin-containing catalysts (eg, dibutyltin oxide), antimony trioxide, titanium-containing catalysts other than (a) (eg, titanium alkoxide, potassium titanyl oxalate, and titanium terephthalate), zirconium-containing catalysts (Eg zirconyl acetate), germanium-containing catalysts, alkali (earth) metal catalysts (eg alkali metal or alkaline earth metal carboxylates: lithium acetate, sodium acetate, potassium acetate, calcium acetate, sodium benzoate, and benzoic acid Potassium), and zinc acetate. The addition amount of these other butterflies is preferably 0 to 0.6% with respect to the obtained polymer. By making it within 0.6%, the coloration of the polyester resin is reduced, which is preferable for use in color toners. The content of (a) in all the added catalysts is preferably 50 to 100%.

  As a method for producing the linear polyester resin (AX1), for example, 0.0001 to 0.8% of butterfly (a) with respect to the weight of the obtained polymer, and optionally in the presence of another catalyst, Examples include a method in which the diol (g) and the dicarboxylic acid (i) are heated to 180 ° C. to 260 ° C. and subjected to dehydration condensation under normal pressure and / or reduced pressure conditions to obtain (AX1).

  As a method for producing the non-linear polyester resin (AX2), for example, 0.0001 to 0.8% of the catalyst (a) with respect to the weight of the obtained polymer, and if necessary, in the presence of another catalyst, Diol (g), dicarboxylic acid (i), and trihydric or higher polyol (h) are heated to 180 ° C. to 260 ° C. and subjected to dehydration condensation under normal pressure and / or reduced pressure conditions. The method of reacting polycarboxylic acid (j) and obtaining (AX2) is mentioned. (J) can also be reacted simultaneously with (g), (i) and (h).

Examples of the method for producing the modified polyester resin (AY1) include a method of obtaining (AY1) by adding a polyepoxide (c) to the polyester resin (AX2) and performing a molecular extension reaction of the polyester at 180 ° C. to 260 ° C. .
The acid value of (AX2) to be reacted with (c) is preferably 1 to 60, more preferably 5 to 50. When the acid value is 1 or more, (c) remains unreacted and does not adversely affect the performance of the resin, and when it is 60 or less, the thermal stability of the resin is good.
In addition, the amount of (c) used to obtain (AY1) is preferably 0.01 to 10%, more preferably 0.8% with respect to (AX2), from the viewpoints of low-temperature fixability and hot offset resistance. 05 to 5%.

Further, in the toner binder (A) of the present invention, in addition to the polycondensed polyester resin, other resins and the like can be contained as necessary.
Other resins include styrene resins (such as copolymers of styrene and alkyl (meth) acrylates, copolymers of styrene and diene monomers), epoxy resins (bisphenol A diglycidyl ether ring-opened polymers, etc.), Examples thereof include urethane resins (diols and / or polyaddition products of trivalent or higher polyols and diisocyanates, etc.).
The weight average molecular weight of the other resin is preferably 1000 to 2 million.
The content of the other resin in the toner binder (A) is preferably 0 to 40%, more preferably 0 to 30%, and particularly preferably 0 to 20%.

When two or more polyester resins are used in combination, and when at least one polyester resin and another resin are mixed, powder mixing or melt mixing may be performed in advance, or they may be mixed at the time of toner formation.
The temperature at the time of melt mixing is preferably 80 to 180 ° C, more preferably 100 to 170 ° C, and particularly preferably 120 to 160 ° C.
If the mixing temperature is too low, sufficient mixing cannot be achieved, which may result in non-uniformity. When two or more kinds of polyester resins are mixed, if the mixing temperature is too high, averaging due to transesterification occurs, so that the resin physical properties necessary as a toner binder may not be maintained.
The mixing time in the case of melt mixing is preferably 10 seconds to 30 minutes, more preferably 20 seconds to 10 minutes, and particularly preferably 30 seconds to 5 minutes. When two or more kinds of polyester resins are mixed, if the mixing time is too long, averaging due to transesterification occurs, so that the resin physical properties required as a toner binder may not be maintained.

Examples of the mixing device in the case of melt mixing include a batch type mixing device such as a reaction tank and a continuous mixing device. In order to uniformly mix at an appropriate temperature in a short time, a continuous mixing device is preferable. Examples of the continuous mixing device include an extruder, a continuous kneader, and a three roll. Of these, extruders and container kneaders are preferred.
In the case of powder mixing, it can be mixed with normal mixing conditions and mixing equipment.
As mixing conditions in the case of powder mixing, the mixing temperature is preferably 0 to 80 ° C, more preferably 10 to 60 ° C. The mixing time is preferably 3 minutes or more, more preferably 5 to 60 minutes. Examples of the mixing apparatus include a Henschel mixer, a Nauter mixer, and a Banbury mixer. A Henschel mixer is preferable.

  The electrostatic image developing toner of the present invention is composed of the toner binder (A) of the present invention and a colorant (B), and if necessary, a release agent (C), a charge control agent (D), and fluidization. Contains various additives such as the agent (E).

  The content of (A) in the toner particles is preferably 70 to 98%, more preferably 74 to 96% when a dye or pigment is used as a colorant, and preferably when a magnetic powder is used. Is 20 to 85%, more preferably 35 to 65%.

Known dyes, pigments and magnetic powders can be used as the colorant (B). Specifically, Carbon Black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, Indian First Orange, Irgasin Red, Paranitaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine Examples include FB, rhodamine B lake, methyl violet B lake, phthalocyanine blue, pigment blue, brilliant green, phthalocyanine green, oil yellow GG, Kayaset YG, orazole brown B, oil pink OP, magnetite and iron black.
The content of the colorant (B) in the toner is preferably 2 to 15% when using a dye or pigment, preferably 15 to 70%, more preferably 30 when using magnetic powder. ~ 60%.

Examples of the release agent (C) include carnauba wax (C1), Fischer-Tropsch wax (C2), paraffin wax (C3), and polyolefin wax (C4).
Examples of (C1) include natural carnauba wax and defree fatty acid type carnauba wax.
(C2) includes petroleum-based Fischer-Tropsch wax (such as Paraflint H1, Paraflint H1N4 and Paraflint C105 manufactured by Schumann-Sazol), natural gas-based Fischer-Tropsch wax (such as FT100 manufactured by Shell MDS), and Fischer-Tropsch What refine | purified wax by methods, such as fractional crystallization [Nippon Seiwa Co., Ltd. product MDP-7000, MDP-7010 etc.], etc. are mentioned.
Examples of (C3) include petroleum wax-based paraffin wax [Nippon Seiwa Co., Ltd. paraffin wax HNP-5, HNP-9, HNP-11, etc.].
Examples of (C4) include polyethylene wax (Sanyo Chemical Industries, Ltd., Sun Wax 171P, Sun Wax LEL400P, etc.), and polypropylene wax (Sanyo Chemical Industries, Ltd., Viscol 550P, Viscol 660P, etc.).
Of these waxes, carnauba wax and Fischer-Tropsch wax are preferred, and carnauba wax and petroleum Fischer-Tropsch wax are more preferred. By using these waxes as release agents, the low-temperature fixability when toner is used is excellent.
The content of (C) in the toner is preferably 0 to 10%, more preferably 1 to 7%.

Examples of the charge control agent (D) include nigrosine dyes, quaternary ammonium salt compounds, quaternary ammonium base-containing polymers, mixed metal azo dyes, salicylic acid metal salts, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic rings. And containing polymers.
The content of (D) in the toner is preferably 0 to 5%, more preferably 0.01 to 4%.

Examples of the fluidizing agent (E) include known materials such as colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.
The content of (E) in the toner particles is preferably 0 to 5%.

In the electrostatic image developing toner of the present invention, inorganic fine particles having excellent abrasiveness can be preferably used as an external additive for assisting fluidity, developability and chargeability. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 nm, and particularly preferably 5 nm to 500 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5.0% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine and nylon, thermosetting resin And polymer particles.

  Such a fluidizing agent performs surface treatment to increase hydrophobicity, and can prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

  Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 nm.

  Examples of the method for producing the toner include a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.), but are not limited thereto. The toner of the present invention is preferably a toner having a small particle size and a nearly spherical shape so as to output a high-quality and high-definition image. As a method for producing such a toner, there are a suspension polymerization method, an emulsion polymerization method, a polymer suspension method and the like in which an oil phase is emulsified, suspended or aggregated in an aqueous medium to form toner base particles. Hereinafter, these toner production methods and materials, additives, etc. used in the production methods will be described.

(Suspension polymerization method)
A colorant, a release agent, and the like are dispersed in an oil-soluble polymerization initiator and a polymerizable monomer, and are emulsified and dispersed by an emulsification method in an aqueous medium containing a surfactant and other solid dispersants. At this time, the particle size of the release agent is controlled by conditions such as the stirring speed and temperature for dispersing the release agent. Thereafter, after a polymerization reaction is performed to form particles, a wet process for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.

  Polymerizable monomers such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, acrylamide, methacrylamide, diacetone Functional groups can be introduced on the surface of toner particles by using a part of acrylate or methacrylate such as acrylamide or these methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate and other amino groups. . Further, by selecting a dispersant having an acid group or a basic group as a dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

(Emulsion polymerization aggregation method)
A water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by an ordinary emulsion polymerization technique. Separately, a dispersion in which a colorant, a release agent having a controlled particle size and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of the inorganic fine particles may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer that can be used in the suspension polymerization method.

(Polymer suspension method)
As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. In the oil phase of the toner composition, a colorant such as a resin, a prepolymer, and a pigment, a release agent with a controlled particle size, a charge control agent, and the like are dissolved or dispersed in a volatile solvent. An oil phase composed of a toner composition is dispersed in an aqueous medium in the presence of a surfactant, a solid dispersant, and the like, and a prepolymer is reacted to form particles. Thereafter, wet processing of the inorganic fine particles may be performed.

(Dry grinding method)
As an example of the pulverization system, a toner having at least a step of mechanically mixing raw materials including a binder resin, a charge control agent, and a colorant, a step of melt-kneading, a step of pulverizing, and a step of classifying A manufacturing method can be applied. Further, in order to improve the dispersibility of the colorant, the colorant may be mixed with other raw materials after the masterbatch treatment and processed to the next step.
The mixing step for mechanical mixing may be performed under normal conditions using a normal mixer with rotating wings, and is not particularly limited. When the above mixing process is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. Specific examples of the apparatus for kneading the toner include a batch type two roll, a Banbury mixer and a continuous type twin screw extruder, such as a KTK type twin screw extruder manufactured by Kobe Steel, a TEM type twin screw manufactured by Toshiba Machine Co., Ltd. Extruder, KCK twin screw extruder, Ikekai Iron Works PCM type twin screw extruder, Kurimoto Iron Works KEX type twin screw extruder, continuous single screw kneader, for example Bush Co. kneader Etc. are preferably used.
The melt-kneaded product obtained as described above is cooled and then pulverized. For pulverization, for example, coarsely pulverized using a hammer mill, a funnel plex, etc. A machine can be used. The pulverization is desirably performed so that the average particle diameter is 3 to 15 μm. Furthermore, the pulverized product is adjusted to a particle size of 2.5 to 20 μm by a wind classifier or the like. Subsequently, the external additive is externally added to the toner particles. The toner particles and the external additive are mixed and stirred using a mixer, and the external additive is crushed and coated on the surface of the toner particles.

According to the present invention, there are provided a tandem type image forming apparatus and an image forming method having at least a plurality of electrophotographic photosensitive members, charging means, exposure means, transfer means, and cleaning means.
As a result, a good full-color image can be obtained at a very high speed as compared with a one-drum type image forming apparatus.
Further, according to the present invention, the intermediate transfer means for primarily transferring the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member and then secondary transferring the toner image on the intermediate transfer member onto the recording material. An image forming apparatus including a plurality of color toner images sequentially superimposed on an intermediate transfer member to form a color image, and the color image is secondarily transferred onto a recording material at once to thereby prevent color misregistration. A suppressed and good image is provided. Furthermore, the layout through the intermediate transfer member increases the degree of freedom of the layout in the image forming apparatus, thereby achieving downsizing of the apparatus and improvement in maintainability.

Next, the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 5 is a schematic view for explaining the image forming apparatus of the present invention. Note that the following modifications also belong to the category of the present invention.
As shown in FIG. 5, the image forming apparatus using the electrophotographic photosensitive member according to the present invention includes a drum-shaped photosensitive member (1), a charging charger (3), and a pre-transfer charger (7). And a transfer charger (10), a separation charger (11), a pre-cleaning charger (13), and the like. The shape of the photoreceptor (1) is not limited to a drum shape, and may be, for example, a sheet shape or an endless belt shape. As various chargers, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller can be used.
As the transfer means, the above charger can be generally used, but a combination of a transfer charger and a separation charger as shown in the figure is effective.

Further, light sources such as the image exposure unit (5) and the charge removal lamp (2) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), electroluminescence (EL). ) And other luminescent materials can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Such a light source or the like can irradiate the photosensitive member with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step in combination with light irradiation in addition to the steps shown in FIG. .

The toner developed on the photosensitive member (1) by the developing unit (6) as the developing means is transferred to the transfer paper (9), but not all is transferred, but the photosensitive member (1). The toner remains on the top. Such toner is removed from the photoreceptor by cleaning means including a cleaning brush (14) and a blade (15). Cleaning may be performed with a cleaning brush or a blade alone, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.
When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. As this developing means, a known method is applied, and a known method is also used as the charge eliminating means.

The image forming apparatus of the present invention can include a contact member that contacts and rubs against the electrophotographic photosensitive member.
As the pressurized contact member, a contact member for the purpose of rubbing the exposed portion of the fluororesin fine particles may be provided, a contact charging member such as a charging roller, a cleaning member such as a cleaning blade or a cleaning brush, a transfer A mechanism for applying pressure to a member generally used in an image forming apparatus such as a transfer member such as a belt or an intermediate transfer belt may be provided. Here, a case where the surface of the photoreceptor is rubbed with the cleaning blade (15) will be described as an example. The cleaning blade is preferable because it has a great effect of rubbing the entire surface of the photosensitive member while pressing the surface of the photosensitive member with a substantially uniform pressure so that the fluororesin fine particles are uniformly attached to the surface.
When the fluororesin is coated with the cleaning blade, the various conditions of the cleaning blade include a blade contact angle of 10 to 30 degrees, a contact pressure of 0.1 to 1.0 N / cm, and a rubber hardness 65 to 80 of urethane rubber used as the blade. Rebound resilience at 25 ° C., 20 to 70%, 300% modulus is 300 kg / cm ² or more, thickness is 1.5 to 3.0 mm, free length is 7 to 12 mm, and the amount of blade edge biting into the photoreceptor is 0. A range of 2 to 2 mm is preferred.

  FIG. 6 shows an example of another process using the image forming apparatus according to the present invention. In FIG. 6, a photoconductor (22) is the electrophotographic photoconductor of the present invention, which is driven by a drive roller (23), charged by a charging charger (20), image exposure by a light source (21), and development (not shown). 1), transfer using the transfer charger (25), cleaning with the brush (26), and static elimination with the light source (27) are repeated.

An embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as a full-color image forming apparatus to which the present invention is applied.
FIG. 7 is a schematic configuration diagram of the printer according to the present embodiment. In the drawing, the photosensitive member (56), which is a latent image carrier, is rotated counterclockwise in the drawing, and the surface thereof is uniformly charged by a charging charger (53) using a corotron, a scorotron, etc. The electrostatic latent image is carried in response to scanning of the laser beam (L) emitted from the laser optical device that does not. Since this scanning is performed based on single-color image information obtained by separating a full-color image into yellow, magenta, cyan, and black color information, a single-color image of yellow, magenta, cyan, or black is used on the photosensitive drum (56). An electrostatic latent image is formed. A revolver developing unit (50) is disposed on the left side of the photosensitive drum (56) in the drawing. This has a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit in a rotating drum-shaped casing, and each developing unit is opposed to the photosensitive drum (56) by the rotation. To move sequentially. The yellow developer, magenta developer, cyan developer, and black developer are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. On the photosensitive drum (56), electrostatic latent images for yellow, magenta, cyan, and black are sequentially formed, and these images are sequentially developed by the developing units of the revolver developing unit (50), so that a yellow toner image, magenta A toner image, a cyan toner image, and a black toner image are obtained.

  An intermediate transfer unit is disposed on the downstream side of the photosensitive drum (56) from the development position. This includes an intermediate transfer belt (58) stretched by a stretch roller (59a), an intermediate transfer bias roller (57) as a transfer means, a secondary transfer backup roller (59b), and a belt drive roller (59c). The belt drive roller (59c) is endlessly moved clockwise in the figure by the rotational drive. The yellow toner image, magenta toner image, cyan toner image, and black toner image developed on the photosensitive drum (56) enter the intermediate transfer nip where the photosensitive drum (56) and the intermediate transfer belt (58) are in contact with each other. To do. Then, while being influenced by the bias from the intermediate transfer bias roller (57), the toner image is superimposed on the intermediate transfer belt (58) and intermediately transferred to form a four-color superimposed toner image.

  The surface of the photosensitive drum (56) that has passed through the intermediate transfer nip with the rotation is cleaned of the transfer residual toner by the drum cleaning unit (55). The cleaning unit (55) is for cleaning the transfer residual toner by a cleaning roller to which a cleaning bias is applied. However, the cleaning unit (55) may be a cleaning brush such as a fur brush or a mag fur brush, or a cleaning blade. Good.

  The surface of the photosensitive drum (56) from which the transfer residual toner has been cleaned is discharged by a discharging lamp (54). As the charge removal lamp (54), a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like is used. A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various filters, such as a sharp cut filter, a band pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

  On the other hand, the registration roller pair (61) that sandwiches the transfer paper (60) sent from a paper feed cassette (not shown) between the two rollers has four colors on the intermediate transfer belt (58). The toner is fed toward the secondary transfer nip at a timing at which the toner image can be superimposed. The four-color superimposed toner images on the intermediate transfer belt (58) are collectively applied onto the transfer paper (P) under the influence of the secondary transfer bias from the paper transfer bias roller (63) in the secondary transfer nip. Secondary transferred. A full color image is formed on the transfer paper 60 by this secondary transfer.

The transfer paper (60) on which the full-color image is formed is sent to the paper transport belt (64) by the transfer belt (62).
The conveying belt (64) feeds the transfer paper (60) received from the transfer unit into the fixing means (65).
The fixing means (65) conveys the transferred transfer paper (60) while being sandwiched between fixing nips formed by the contact between the heating roller and the backup roller.
The full-color image on the transfer paper (60) is fixed on the transfer paper (60) under the influence of heating from the heating roller and pressure in the fixing nip.

  Although not shown, a bias for adsorbing the transfer paper (P) is applied to the transfer belt (62) and the conveyance belt (64). In addition, a paper neutralization charger that neutralizes the transfer paper (60) and three belt neutralization chargers that neutralize each belt (intermediate transfer belt (58), transfer belt (62), and conveyance belt (64)) are provided. Yes. The intermediate transfer unit also includes a belt cleaning unit having the same configuration as that of the drum cleaning unit (55), thereby cleaning the transfer residual toner on the intermediate transfer belt (58).

FIG. 8 shows a modification of the image forming apparatus according to this embodiment. This apparatus is a tandem type image forming apparatus having an intermediate transfer belt (87), and does not share the photosensitive drum (80) for each color, but the photosensitive drums (80Y), (80M) for the respective colors. (80C), (80Bk). A drum cleaning unit (85), a charge removal lamp (83), and a charging roller (84) for uniformly charging the drum are also provided for each color. In the printer shown in FIG. 7, the charging charger (53) is provided as the drum uniform charging means, but in this apparatus, the charging roller (84) is provided.
In the tandem method, latent image formation and development of each color can be performed in parallel, so that the image formation speed can be much higher than in the revolver method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, this invention is not limited to the Example and comparative example which are illustrated here. In addition, the part in an Example represents a weight part.
(Production of photoconductor)
First, a preparation example of the photoreceptor used for evaluation will be specifically described. The photoreceptor used in the present invention is not limited to these examples.
[Photoreceptor 1]
15 parts by weight of alkyd resin (Beckolite M6401-50 (manufactured by Dainippon Ink and Chemicals)), 10 parts by weight of melamine resin (Super Becamine G-821-60 (manufactured by Dainippon Ink and Chemicals)) and 150 parts by weight of methyl ethyl ketone 90 parts by weight of titanium oxide powder (Typer CR-EL (manufactured by Ishihara Sangyo Co., Ltd.)) was added thereto and dispersed with a ball mill for 12 hours to prepare an undercoat layer coating solution.
This was coated on a cylindrical aluminum substrate having a diameter of 90 mm and a length of 392 mm by a dip coating method and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 3.5 μm.
Next, 4 parts by weight of polyvinyl butyral resin (XYHL (manufactured by UCC)) was dissolved in 150 parts by weight of cyclohexanone, which is shown in the following structural formula (1).

10 parts by weight was added to the bisazo pigment and dispersed for 48 hours by a ball mill, and further 210 parts by weight of cyclohexanone was added and dispersed for 3 hours. This was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by weight. The charge generation layer coating solution thus obtained was applied onto the intermediate layer and dried at 130 ° C. for 20 minutes to form a charge generation layer having a thickness of 0.2 μm.
Next, in 100 parts by weight of tetrahydrofuran, 10 parts by weight of bisphenol Z-type polycarbonate resin and 0.002 parts by weight of silicone oil (KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)) are dissolved. A charge transport layer coating solution was prepared by adding 10 parts by weight of the charge transport material. The charge transport layer coating solution thus obtained was applied onto the charge generation layer by a dip coating method and then dried at 110 ° C. for 20 minutes to form a charge transport layer having a thickness of 20 μm.

Next, in a mixed solvent of 60 parts by weight of tetrahydrofuran and 20 parts by weight of cyclohexanone, 17 parts by weight of perfluoroalkoxy resin fine particles (PFA) (MPE-056, manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), a dispersion aid (trade name: Modiper) F210 (manufactured by Nippon Oil & Fats Co., Ltd.) is mixed with 3 parts by weight, and is circulated for 1 hour under a pressure of 100 MPa in a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.). Obtained. In addition, a resin solution in which 16 parts by weight of bisphenol Z-type polycarbonate was dissolved in a mixed solvent of 420 parts by weight of tetrahydrofuran and 120 parts by weight of cyclohexanone was prepared, and ultrasonic waves were applied to the coating solution obtained by adding 100 parts by weight of the PFA dispersion. Was irradiated for 10 minutes to prepare a coating solution for forming a protective layer. After the coating solution for forming the protective layer thus obtained was spray coated on the charge transport layer using a spray gun (Peacecon PC308, manufactured by Olympos) at an air pressure of ² kgf / cm ² , and after three times of coating Then, the film was dried at 130 ° C. for 20 minutes to form a protective layer having a thickness of 5 μm.

  The sampled coating film surface was accelerated using FE-SEM (S-4200 scanning electron microscope, manufactured by Hitachi, Ltd.) for any 10 observation points on the surface of the electrophotographic photoreceptor thus obtained. The surface was photographed 4000 times at a voltage of 2 kv, and the obtained SEM photograph was subjected to image processing software (IMAGE Pro Plus), and the number of PFA particles (primary particles and aggregated secondary particles) and the average diameter of each particle. The area and area ratio were analyzed, and the total area ratio of particles having an average diameter of 0.15 to 3 μm was calculated as S1, and the total area ratio of particles having an average diameter of 0.2 to 1.5 μm was calculated as S2.

[Photoreceptor 2]
An ultrasonic wave was irradiated for 10 minutes to a coating solution in which 55 parts by weight of a PFA dispersion was added to a resin solution in which 16 parts by weight of bisphenol Z polycarbonate was dissolved in a mixed solvent of 420 parts by weight of tetrahydrofuran and 120 parts by weight of cyclohexanone. The photoconductor 2 was prepared in the same manner as the photoconductor 1 except that the protective layer-forming coating solution was prepared, and the same measurement as that of the photoconductor 1 was performed.

[Photoreceptor 3]
An ultrasonic wave was irradiated for 10 minutes to a coating solution in which 300 parts by weight of a PFA dispersion was added to a resin liquid in which 16 parts by weight of bisphenol Z-type polycarbonate was dissolved in a mixed solvent of 420 parts by weight of tetrahydrofuran and 120 parts by weight of cyclohexanone. The photoconductor 3 was prepared in the same manner as the photoconductor 1 except that the protective layer forming coating solution was prepared, and the same measurement as that of the photoconductor 1 was performed.

[Photosensitive member 4]
Except that the PFA dispersion was prepared by circulating the dispersion conditions with a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.) under a pressure of 60 MPa for 20 minutes. Photoconductor 4 was prepared and the same measurement as that of photoconductor 1 was performed.

[Photoreceptor 5]
Except for dissolving 16 parts by weight of bisphenol Z-type polycarbonate and 10 parts by weight of the charge transport material of the above structural formula (2) in a mixed solvent of 420 parts by weight of tetrahydrofuran and 120 parts by weight of cyclohexanone to obtain a resin liquid containing a charge transport material. Prepared the photoconductor 5 in the same manner as the photoconductor 1 and measured in the same manner as the photoconductor 1.

[Photoreceptor 6]
A photoconductor 6 was prepared in the same manner as the photoconductor 1 except that polytetrafluoroethylene resin fine particles (PTFE) were used instead of PFA, and the same measurement as that of the photoconductor 1 was performed.

[Photoreceptor 7]
A photoconductor 7 was prepared in the same manner as the photoconductor 2 except that polytetrafluoroethylene resin fine particles (PTFE) were used instead of PFA, and the same measurement as that of the photoconductor 1 was performed.

[Photoreceptor 8]
Photosensitive except that a PFA dispersion was prepared by dispersing for 48 hours in a sand mill using glass beads with a diameter of 1 mm instead of using a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.). A photoconductor 8 was produced in the same manner as the photoconductor 1 and the same measurement as that of the photoconductor 1 was performed.

[Photoreceptor 9]
Photosensitive except that a PFA dispersion was prepared by dispersing for 48 hours in a sand mill using φ1 mm glass beads instead of dispersion by a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.). A photoconductor 9 was prepared in the same manner as the photoconductor 2 and the same measurement as that of the photoconductor 1 was performed.

[Photosensitive member 10]
Photosensitive except that a PFA dispersion was prepared by dispersing for 48 hours in a sand mill using φ1 mm glass beads instead of dispersion by a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.). A photoconductor 10 was prepared in the same manner as the photoconductor 3 and the same measurement as that of the photoconductor 1 was performed.

[Photoreceptor 11]
Instead of dispersing with a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005, manufactured by Sugino Machine Co., Ltd.) A photoconductor 11 was prepared in the same manner as the photoconductor 6 and the same measurement as that of the photoconductor 1 was performed.
The evaluation results thus obtained are shown in Table 1.

(Production of toner)
Next, a preparation example of the toner used for evaluation will be specifically described. The toner used in the present invention is not limited to these examples.
The softening point in the text is measured by the following method.
[Measurement method of softening point]
Using a flow tester, the temperature is raised at a constant speed under the following conditions, and the temperature at which the outflow amount becomes 1/2 is defined as the softening point.
Apparatus: Shimadzu Corporation flow tester, CTF-500D
Load: 20 kgf / cm ²
Die: 1mmΦ-1mm
Temperature increase rate: 6 ° C / min
Sample amount: 1.0 g

[Toner A]
~ Synthesis of titanium-containing catalyst (a) ~
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introducing tube capable of bubbling in the liquid, 1617 parts of titanium diisopropoxybis (triethanolaminate) and 126 parts of ion-exchanged water are placed in the liquid with nitrogen. Under bubbling, the temperature was gradually raised to 90 ° C. and reacted (hydrolyzed) at 90 ° C. for 4 hours to obtain titanium dihydroxybis (triethanolaminate).
The titanium-containing catalyst (a) used in the present invention can be obtained by the same synthesis method for the following prepared toners.

~ Synthesis of linear polyester resin ~
In a reactor equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 430 parts of PO2 molar adduct of bisphenol A, 300 parts of PO3 molar adduct of bisphenol A, 257 parts of terephthalic acid, 65 parts of isophthalic acid, maleic anhydride 10 parts of acid and 2 parts of titanium dihydroxybis (triethanolaminate) as a condensation catalyst were added and reacted for 10 hours at 220 ° C. while distilling off the water produced under a nitrogen stream. Subsequently, it was made to react under the reduced pressure of 5-20 mmHg, and when the acid value became 5, it took out, cooled to room temperature, and grind | pulverized, and the linear polyester resin (AX1-1) was obtained.
(AX1-1) contained no THF-insoluble matter, and had an acid value of 7, a hydroxyl value of 12, Tg of 60 ° C., Mn of 6940, and Mp of 19100. The ratio of components having a molecular weight of 1500 or less was 1.2%.

~ Synthesis of non-linear polyester resin ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 350 parts of EO2 molar adduct of bisphenol A, 326 parts of PO3 molar adduct of bisphenol A, 278 parts of terephthalic acid, 40 parts of phthalic anhydride and condensation As a catalyst, 2 parts of titanium dihydroxybis (triethanolaminate) was added and reacted at 230 ° C. for 10 hours while distilling off the water produced in a nitrogen stream. Next, the reaction is carried out under reduced pressure of 5 to 20 mmHg. When the acid value becomes 2 or less, the mixture is cooled to 180 ° C., added with 62 parts of trimellitic anhydride, taken out after reaction for 2 hours under sealed at normal pressure, and cooled to room temperature. To obtain a non-linear polyester resin (AX2-1).
(AX2-1) contained no THF-insoluble matter, and its acid value was 35, the hydroxyl value was 17, Tg was 69 ° C., Mn was 3920, and Mp was 11200. The ratio of components having a molecular weight of 1500 or less was 0.9%.

~ Synthesis of toner binder ~
400 parts of (AX1-1) and 600 parts of (AX2-1) were melt-mixed with a continuous kneader at a jacket temperature of 150 ° C. and a residence time of 3 minutes. The molten resin was cooled to 30 ° C. for 4 minutes using a steel belt cooler and then pulverized to obtain the toner binder (TB1) of the present invention.

~ Toner creation ~
After pre-mixing 100 parts of toner binder (TB1), 5 parts of carnauba wax and 4 parts of yellow pigment [toner yellow HG VP2155 manufactured by Clariant Co., Ltd.] using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.] It knead | mixed with the biaxial kneader [The product made from Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I] and the particle size D50 8 μm toner particles were obtained. Subsequently, 100 parts of toner particles were mixed with 0.5 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] using a sample mill to obtain toner A.

[Toner B]
~ Synthesis of linear polyester resin ~
A linear polyester resin (AX1-2) was obtained by reacting in the same manner as (AX1-1) of toner A except that the polycondensation catalyst was replaced with titanylbis (triethanolaminate), cooling to room temperature, and pulverizing.
(AX1-2) contained no THF-insoluble matter, and had an acid value of 8, a hydroxyl value of 10, Tg of 60 ° C., Mn of 6820, and Mp of 20180. The ratio of components having a molecular weight of 1500 or less was 1.1%.

~ Synthesis of non-linear polyester resin ~
A linear polyester resin (AX2-2) was obtained by reacting in the same manner as (AX2-1) of toner A except that the polycondensation catalyst was replaced with titanylbis (triethanolaminate), cooling to room temperature, and pulverizing.
(AX2-2) contained no THF-insoluble matter, and its acid value was 33, the hydroxyl value was 14, Tg was 70 ° C., Mn was 4200, and Mp was 11800. The ratio of components having a molecular weight of 1500 or less was 0.8%.

~ Synthesis of toner binder ~
500 parts of polyester (AX1-2) and 500 parts of polyester (AX2-2) were powder mixed for 5 minutes with a Henschel mixer to obtain a toner binder resin (TB2) of the present invention.

~ Toner creation ~
After premixing 100 parts of toner binder (TB2), 5 parts of carnauba wax and 4 parts of yellow pigment [toner yellow HG VP2155 manufactured by Clariant Co., Ltd.] using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.] It knead | mixed with the biaxial kneader [Corporation | KK Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I] and the particle size D50 8 μm toner particles were obtained. Next, 100 parts of the toner particles were mixed with 0.5 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] in a sample mill to obtain toner B.

[Toner C]
~ Synthesis of comparative linear polyester resin ~
The reaction was carried out in the same manner as (AX1-1) of toner A except that the polycondensation catalyst was replaced with titanium tetraisopropoxide. Since the reaction was stopped in the middle due to catalyst deactivation and the generated water could not be distilled, 2 parts of titanium tetraisopropoxide was added four times during the reaction, and a comparative linear polyester resin (CAX1) was added. -1) was obtained.
(CAX1-1) contained no THF-insoluble matter, and had an acid value of 7, a hydroxyl value of 12, Tg of 58 ° C., Mn of 6220, and Mp of 18900. The ratio of components having a molecular weight of 1500 or less was 2.2%.

~ Synthesis of non-linear polyester resin for comparison ~
The reaction was conducted in the same manner as (AX2-1) of toner A, except that the polycondensation catalyst was replaced with titanium tetraisopropoxide. The reaction was allowed to proceed for 16 hours under normal pressure and for 8 hours under reduced pressure. Since the reaction rate was slow, 2 parts of titanium tetrapropoxide were added three times during the reaction to obtain a comparative non-linear polyester resin (CAX2-1).
(CAX2-1) did not contain THF-insoluble matter, and its acid value was 34, the hydroxyl value was 16, Tg was 68 ° C., Mn was 3420, and Mp was 12100. The ratio of components having a molecular weight of 1500 or less was 2.1%.

~ Synthesis of comparative toner binder ~
400 parts of (CAX1-1) and 600 parts of (CAX2-1) were melt-mixed with a continuous kneader at a jacket temperature of 150 ° C. and a residence time of 3 minutes. The molten resin was cooled to 30 ° C. for 4 minutes using a steel belt cooler and then pulverized to obtain a comparative toner binder (CTB1). (CTB1) was a strong purple-brown resin.

~ Toner creation ~
After premixing 100 parts of toner binder (CTB1), 5 parts of carnauba wax and 4 parts of yellow pigment [toner yellow HG VP2155 manufactured by Clariant Co., Ltd.] using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.] It knead | mixed with the biaxial kneader [The product made from Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I] and the particle size D50 8 μm toner particles were obtained. Next, 100 parts of the toner particles were mixed with 0.5 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] using a sample mill to obtain toner C.

[Toner D]
~ Synthesis of modified polyester resin ~
549 parts of bisphenol A propylene oxide 2 mol adduct, 20 parts of bisphenol A propylene oxide 3 mol adduct, 133 parts of bisphenol A ethylene oxide 2 mol adduct in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe , 10 parts of an ethylene oxide 5 mol adduct of phenol novolac (average degree of polymerization about 5), 252 parts of terephthalic acid, 19 parts of isophthalic acid, 10 parts of trimellitic anhydride and 2 parts of titanium dihydroxybis (diethanolamate) as a condensation catalyst The reaction was carried out for 10 hours at 230 ° C. while distilling off the water produced under a nitrogen stream. Subsequently, it was made to react under reduced pressure of 5-20 mmHg, and it was made to react until an acid value became 2 or less. Next, 50 parts of trimellitic anhydride was added and reacted at normal pressure for 1 hour. After reacting under reduced pressure of 20 to 40 mmHg and the softening point reached 105 ° C., 20 parts of bisphenol A diglycidyl ether was added, After taking out at a softening point of 150 ° C., cooling to room temperature, and pulverizing, a modified polyester resin (AY1-1) was obtained.
The acid value of (AY1-1) is 52, the hydroxyl value is 16, Tg is 73 ° C., Mn is 1860, Mp is 6550, THF insoluble matter is 32%, and the ratio of components having a molecular weight of 1500 or less is 1.0%. This was used as a toner binder (TB3).

~ Toner creation ~
100 parts of toner binder (TB3), 8 parts of carbon black MA-100 [manufactured by Mitsubishi Chemical Corporation], 5 parts of carnauba wax, 1 part of charge control agent T-77 (manufactured by Hodogaya Chemical Co., Ltd.) After premixing using FM10B manufactured by Kako Koki Co., Ltd., the mixture was kneaded using a biaxial kneader [manufactured by Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I], and the particle size D50 is 9 μm toner particles were obtained. Next, 100 parts of toner particles and 0.3 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] were mixed in a sample mill to obtain toner D.

[Toner E]
~ Synthesis of modified polyester resin for comparison ~
A modified polyester resin for comparison (CAY1-2) was obtained by reacting in the same manner as the toner D except that the polycondensation catalyst was replaced with titanium tetrabutoxide.
(CAY1-2) has a softening point of 150 ° C., an acid value of 53, a hydroxyl value of 17, Tg of 71 ° C., Mn of 1660, Mp of 6340, a THF insoluble content of 34%, and a ratio of components having a molecular weight of 1500 or less. This was 3.1%, and this was used as a toner binder (CATB2).

~ Toner creation ~
100 parts of toner binder (CATB2), 8 parts of carbon black MA-100 [Mitsubishi Chemical Co., Ltd.], 5 parts of carnauba wax, 1 part of charge control agent T-77 (Hodogaya Chemical Co., Ltd.) After premixing using FM10B manufactured by Kako Koki Co., Ltd., the mixture was kneaded using a twin-screw kneader [manufactured by Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I], and the particle size D50 is 9 μm toner particles were obtained. Next, 100 parts of toner particles were mixed with 0.3 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] in a sample mill to obtain toner E.

[Toner F]
~ Synthesis of non-linear polyester resin ~
132 parts of bisphenol A propylene oxide 2-mole adduct, 371 parts of bisphenol A propylene oxide 3-mole adduct, 20 parts of bisphenol A ethylene oxide 2-mole adduct, 125 parts of propylene oxide 5 mol adduct of phenol novolak (average degree of polymerization about 5), 201 parts of terephthalic acid, 25 parts of maleic anhydride, 35 parts of dimethyl terephthalic acid ester and 2 parts of titanyl bis (triethanolamate) as a condensation catalyst The reaction was carried out for 10 hours at 230 ° C. while distilling off the water produced under a nitrogen stream. Next, the reaction is carried out under a reduced pressure of 5 to 20 mmHg. When the acid value becomes 2 or less, the mixture is cooled to 180 ° C., added with 65 parts of trimellitic anhydride, taken out after reaction for 2 hours under sealed at normal pressure, and cooled to room temperature. To obtain a non-linear polyester resin (AX2-3).
The non-linear polyester resin (AX2-3) has a softening point of 144 ° C., an acid value of 30, a hydroxyl value of 16, Tg of 59 ° C., Mn of 1410, Mp of 4110, a THF insoluble content of 27%, and a molecular weight of 1500 or less. The ratio of this component was 1.0%, and this was used as a toner binder (TB4).

~ Toner creation ~
100 parts of toner binder (TB4), 8 parts of carbon black MA-100 [manufactured by Mitsubishi Chemical Co., Ltd.], 5 parts of carnauba wax, 1 part of charge control agent T-77 (manufactured by Hodogaya Chemical Co., Ltd.) After premixing using FM10B manufactured by Kako Koki Co., Ltd., the mixture was kneaded using a twin-screw kneader [manufactured by Ikegai, PCM-30]. Next, the mixture was finely pulverized using a supersonic jet crusher lab jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], and then classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.], and the particle size D50 was 9 μm. Toner particles were obtained. Next, 100 parts of toner particles were mixed with 0.3 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] in a sample mill to obtain toner F.

[Toner G]
~ Synthesis of non-linear polyester resin ~
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 410 parts of bisphenol A propylene oxide 2 mol adduct, 270 parts of bisphenol A propylene oxide 3 mol adduct, 110 parts terephthalic acid, 125 parts isophthalic acid, 15 parts of maleic anhydride and 2 parts of titanium dihydroxybis (triethanolaminate) as a condensation catalyst were added and reacted at 220 ° C. for 10 hours while distilling off the water produced under a nitrogen stream. Next, the reaction is carried out under a reduced pressure of 5 to 20 mmHg, and when the acid value becomes 2 or less, it is cooled to 180 ° C., 25 parts of trimellitic anhydride is added, taken out after reaction for 2 hours under normal pressure sealing, and cooled to room temperature. By pulverizing, a non-linear polyester resin (AX2-4) was obtained.
(AX2-4) contained no THF-insoluble matter, and had an acid value of 18, a hydroxyl value of 37, Tg of 62 ° C., Mn of 2130, and Mn of 5350. The ratio of components having a molecular weight of 1500 or less was 1.3%.

~ Synthesis of modified polyester resin ~
317 parts of bisphenol A ethylene oxide 2 mol adduct, 57 parts of bisphenol A propylene oxide 2 mol adduct, 298 parts of bisphenol A propylene oxide 3 mol adduct, 75 parts of a propylene oxide 5 mol adduct of phenol novolac (average polymerization degree of about 5), 30 parts of isophthalic acid, 157 parts of terephthalic acid, 27 parts of maleic anhydride and 2 parts of titanium dihydroxybis (triethanolaminate) as a condensation catalyst The reaction was carried out for 10 hours while distilling off the water produced at 230 ° C. under a nitrogen stream. Next, the reaction was carried out under a reduced pressure of 5 to 20 mmHg, and when the acid value became 2 or less, the mixture was cooled to 180 ° C., then 68 parts of trimellitic anhydride was added, and the mixture was reacted at normal pressure for 1 hour. When the softening point is 120 ° C by reaction under reduced pressure, 25 parts of bisphenol A diglycidyl ether is added, taken out at a softening point of 155 ° C, cooled to room temperature, pulverized, and modified polyester resin (AY1-2) is obtained. Obtained.
The acid value of (AY1-2) was 11, the hydroxyl value was 27, Tg was 60 ° C., Mn was 3020, Mp was 6030, and the THF-insoluble content was 35%. The ratio of components having a molecular weight of 1500 or less was 1.1%.

~ Synthesis of toner binder ~
500 parts of (AX2-3) and 500 parts of (AY1-2) were melt-mixed with a continuous kneader at a jacket temperature of 150 ° C. and a residence time of 3 minutes. The molten resin was cooled to 30 ° C. for 4 minutes using a steel belt cooler and then pulverized to obtain a toner binder (TB5) of the present invention.

~ Toner creation ~
100 parts of toner binder (TB5), 8 parts of carbon black MA-100 [Mitsubishi Chemical Co., Ltd.], 5 parts of carnauba wax, 1 part of charge control agent T-77 (Hodogaya Chemical Co., Ltd.) After premixing using FM10B manufactured by Kako Koki Co., Ltd., the mixture was kneaded using a biaxial kneader [manufactured by Ikegai, PCM-30]. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I], and the particle size D50 is 9 μm toner particles were obtained. Next, 100 parts of toner particles were mixed with 0.3 part of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] in a sample mill to obtain toner G.

(Carrier production)
Acrylic resin solution (solid content 50 wt%) 21.0 parts Guanamin solution (solid content 70 wt%) 6.4 parts Alumina particles [0.3 μm, specific resistance 10 ¹⁴ (Ω · cm)] 7.6 parts Silicon resin solution [ Solid content 23 wt% (SR2410: manufactured by Toray Dow Corning Silicone)] 65.0 parts Aminosilane [solid content 100 wt% (SH 6020: manufactured by Toray Dow Corning Silicone)] 1.0 parts Toluene 60 parts Butyl cellosolve 60 parts Was dispersed with a homomixer for 10 minutes to obtain a blend coating film forming solution of an acrylic resin and a silicon resin containing alumina particles. A fired ferrite powder [(MgO) _1.8 (MnO) _49.5 (Fe ₂ O ₃ ) _48.0 : average particle size; 35 μm] was used as the core material, and the coating film forming solution was applied to the surface of the core material. It was applied by a Spira coater (Okada Seiko Co., Ltd.) so as to have a thickness of 0.15 μm and dried. The obtained carrier was baked by standing in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 106 μm to obtain [Carrier]. The measurement of the binder resin film thickness was performed by observing the cross section of the carrier with a transmission electron microscope so that the coating film covering the carrier surface could be observed.

(Preparation of two-component developer)
Using the toners A to G and the carrier, 7 parts by weight of the toner with respect to 100 parts by weight of the carrier were uniformly mixed and charged using a type of tumbler mixer in which the container was rolled and stirred to prepare a developer.

(Examples and Comparative Examples)
The two-component developer and photoreceptor obtained as described above were used in Examples 1 to 9 and Comparative Examples 1 to 4 in the combinations shown in Table 2, and the following evaluations were made. The results are also shown in Table 2.

(Evaluation methods)
A test in which the two-component developer shown in Table 2 and an electrophotographic photosensitive member are set in an evaluation machine which is tuned by remodeling a full-color composite machine Imagio NeoC 455 (manufactured by Ricoh), and becomes an A4 size and an image area ratio of 5%. A running test to output images was performed.

[Abrasion amount measurement]
After running 80,000 sheets, the respective photoreceptors were taken out, and the amount of wear was measured from the difference in the film thickness of the photosensitive layer before and after the running test. For film thickness measurement, an eddy current film thickness meter Fischer scope MMS (manufactured by Fischer) was used.

[Cleanability]
After running 80,000 sheets, each photoconductor is taken out, and the toner remaining on the photoconductor after passing through the cleaning blade is collected by Nitto Denko's Printerac C (thickness 25 μm) and pasted on a white paper, 938 Spectrodencite Using a meter (manufactured by X-Rite), 10 points of ID were measured at an observation light source D ₅₀ and a viewing angle of 2 ° to calculate an average value, and the difference from the blank was 0.005 or less. 006 to 0.010 were evaluated as O, 0.011 to 0.015 as Δ, and 0.016 or more as X.

[Additive burial degree]
The toner is collected from the developing unit sleeve after the completion of 80,000 sheets of running, and the degree of burying of the additive in the toner base is observed with a FE-SEM (S-4200) manufactured by Hitachi, and the additive is not buried at all. The state was ranked 5, and the state where it was completely buried and not present on the toner surface was ranked 1, and the ranking was performed in a 5-level evaluation.
Note that the FE-SEM apparatus is not particularly limited as long as the same observation can be performed.

[S1, S2]
Accelerating voltage of 2 kv using FE-SEM (S-4200 scanning electron microscope, manufactured by Hitachi, Ltd.) for the sampled coating film surface at 10 arbitrary observation points on the surface of the photoreceptor after running 80,000 sheets. The surface of the specimen was photographed at a magnification of 4000 times, and the obtained SEM photograph was subjected to image processing software (IMAGE Pro Plus) to determine the number of PFA particles (primary particles and aggregated secondary particles), the average diameter and area of each particle. The area ratio was analyzed, and the total area ratio of particles having an average diameter of 0.15 to 3 μm was calculated as S1, and the total area ratio of particles having an average diameter of 0.2 to 1.5 μm was calculated as S2.

FIG. 2 is a schematic cross-sectional view illustrating an example of a layer configuration of the electrophotographic photosensitive member of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member of the present invention. 1 is a schematic view of an example of an image forming apparatus of the present invention. It is the schematic which shows the other process of the image forming apparatus of this invention. 1 is a schematic configuration diagram of a printer as an example of an image forming apparatus of the present invention. FIG. 2 is a schematic configuration diagram of a modification example of a printer that is an example of the image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charge charger 5 Image exposure part 6 Developing unit 7 Pre-transfer charger 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Pre-cleaning charger 14 Cleaning brush 15 Blade 20 Charge charger 21 Image exposure Light source 22 Photoconductor 23 Driving roller 24 Tension roller 25 Transfer charger 26 Cleaning brush 27 Static elimination light source 50 Development unit 53 Charge charger 54 Static elimination lamp 55 Drum cleaning unit 56 Photoconductor 57 Bias roller 58 Intermediate transfer belt 59a Stretching roller 59b Backup roller 59c Belt drive roller 60 Transfer paper (image carrier)
61 Registration roller 62 Transfer belt 63 Paper transfer bias roller 64 Conveying belt 65 Fixing unit 80 Photoconductor 81 Exposure light source 82 Development unit 83 Static elimination lamp 84 Charging roller 85 Cleaning kit 86 Bias roller 87 Intermediate transfer belt 88 Registration roller 89 Paper (image bearing) body)
90 Paper transfer bias roller 91 Transfer belt 92 Conveying belt 93 Fixing unit 94 Fur brush L Laser light P Transfer paper

Claims (16)

A charging unit that uniformly charges the electrophotographic photosensitive member, an exposure unit that writes an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and a visible image of the electrostatic latent image formed on the surface of the electrophotographic photosensitive member Developing means, transfer means for transferring a visible image on the surface of the electrophotographic photosensitive member directly or via an intermediate transfer member, fixing means for fixing the visible image on the recording member, and the photosensitive member An image forming apparatus comprising: cleaning means for cleaning the upper transfer residual toner;
The electrophotographic photosensitive member has at least a photosensitive layer on a conductive support, contains fluororesin fine particles in the outermost layer, and the fluororesin fine particles have a plurality of primary particles and a plurality of primary particles in the outermost layer film. When the average diameter of the agglomerated secondary particles (in the projected image of the portion exposed on the surface) is D, the (projected) area of the particles in the range of 0.15 ≦ D ≦ 3 μm. The total ratio is always maintained at 10% to 60% even in the initial state and in the state where the outermost layer has been polished over time, and the toner used in the developing means has a toner binder made of a polycondensation polyester resin, An image forming apparatus, wherein the polyester resin is a resin formed in the presence of at least one titanium-containing catalyst (a) represented by the following general formula (I) or (II).

[Wherein X is a residue obtained by removing H of one OH group from a mono- or polyalkanolamine having 2 to 12 carbon atoms, and other OH groups of polyalkanolamine are directly bonded to the same Ti atom. The OH group may be polycondensed in the molecule to form a ring structure, or the OH group directly bonded to another Ti atom may be polycondensed between the molecules to form a repeating structure. The degree of polymerization in the case of forming a repeating structure is 2-5. R is H or an alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds. m is an integer of 1 to 4, n is an integer of 0 to 3, and the sum of m and n is 4. p is an integer of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. When m or p is 2 or more, each X may be the same or different. ] Of the primary particles of the fluororesin fine particles and the secondary particles formed by agglomerating a plurality of primary particles, projections of particles having an average diameter D in the range of 0.2 ≦ D ≦ 1.5 μm on the surface 2. The image forming apparatus according to claim 1, wherein the total area ratio is always maintained at 10% to 60% even in a state where the outermost surface layer is polished at the initial stage and over time. 3. The image forming apparatus according to claim 1, wherein a ratio of the fluororesin fine particles to the outermost layer is 20 vol% to 70 vol%. The photosensitive layer is composed of a layer containing at least a charge generating substance and a charge transporting substance and a protective layer laminated thereon, and the protective layer is a layer containing at least a binder resin and fluororesin fine particles. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The image forming apparatus according to claim 1, wherein the outermost layer contains at least a charge transport material. 6. The image forming apparatus according to claim 1, further comprising a contact member that contacts and rubs at least the surface of the electrophotographic photosensitive member. The image forming apparatus according to claim 6, wherein the fluororesin fine particles contained in the outermost layer extend and are coated on the surface of the outermost layer by the contact member. The titanium-containing catalyst (a) is characterized in that X in the general formulas (I) and (II) is a residue obtained by removing one OH group H from a di- or trialkanolamine. Item 8. The image forming apparatus according to any one of Items 1 to 7. The titanium-containing catalyst (a) is characterized in that m or p in the general formulas (I) and (II) is 2 or more, and all Xs are the same group. An image forming apparatus according to claim 1. The image forming apparatus according to claim 1, wherein at least a part of the polyester resin is modified with polyepoxide (c) in the toner binder. The image forming apparatus according to claim 1, wherein the toner contains a toner binder (A) and a colorant (B). 12. The toner according to claim 1, wherein the toner further contains at least one additive selected from a release agent (C), a charge control agent (D), and a fluidizing agent (E). The image forming apparatus according to any one of the above. 13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a tandem type having a plurality of electrophotographic photosensitive members, a charging unit, a developing unit, a transfer unit, and a cleaning unit. The image forming apparatus includes an intermediate transfer unit that primarily transfers a toner image developed on an electrophotographic photosensitive member onto an intermediate transfer member and then secondary-transfers the toner image on the intermediate transfer member onto a recording material. 2. An image forming apparatus, wherein a plurality of color toner images are sequentially superimposed on an intermediate transfer member to form a color image, and the color image is secondarily transferred onto a recording material at a time. 14. The image forming apparatus according to any one of items 13 to 13. An image forming method, comprising: forming an image using the image forming apparatus according to claim 1. It is detachable from the image forming apparatus, has at least a photosensitive layer on a conductive support, contains fluororesin fine particles in the outermost layer, and the fluororesin fine particles are primary particles and a plurality of primary particles in the outermost layer film. When the average diameter of the agglomerated secondary particles (in the projected image of the portion exposed on the surface) is D, the (projected) area of the particles in the range of 0.15 ≦ D ≦ 3 μm. The toner binder is a polycondensation polyester in the electrophotographic photoreceptor or the toner used in the developing means in which the total ratio is always maintained at 10% to 60% even when the outermost layer is polished in the initial state and over time. There are few developing means using a toner comprising a resin and the polyester resin is a resin formed in the presence of at least one titanium-containing catalyst (a) represented by the following general formula (I) or (II). Have at least
15. A process cartridge for an image forming apparatus, wherein the image forming apparatus constitutes the image forming apparatus according to claim 1 when mounted on the image forming apparatus.

[Wherein X is a residue obtained by removing H of one OH group from a mono- or polyalkanolamine having 2 to 12 carbon atoms, and other OH groups of polyalkanolamine are directly bonded to the same Ti atom. The OH group may be polycondensed in the molecule to form a ring structure, or the OH group directly bonded to another Ti atom may be polycondensed between the molecules to form a repeating structure. The degree of polymerization in the case of forming a repeating structure is 2-5. R is H or an alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds. m is an integer of 1 to 4, n is an integer of 0 to 3, and the sum of m and n is 4. p is an integer of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. When m or p is 2 or more, each X may be the same or different. ]

Images