JP2008310029A - Image forming apparatus, process cartridge, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method, suppressing the remaining of toner to a photoreceptor after transfer over a long period, and forming a high quality image, and also to provide a process cartridge used for the image forming apparatus. <P>SOLUTION: The image forming apparatus 100 is of a normal development system, and comprises: a photoreceptor 1; a charging device 2 charging the photoreceptor 1; an exposure device 3 forming an electrostatic latent image on the charged photoreceptor 1; and a development device 4 having development units 4a, 4b, 4c and 4d developing the electrostatic latent image with toner. For the photoreceptor 1, in the region where the electrostatic latent image is formed, the ratio of the transit time t<SB>T</SB>of the photoreceptor 1 to the process time T<SB>ed</SB>till the electrostatic latent image is developed from its formation is 1.0 to 1.3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, a process cartridge, and an image forming method.

  In image forming apparatuses such as copying machines, printers, and facsimiles using an electrophotographic system, a charging device is used to uniformly charge the surface of an electrophotographic photosensitive member (hereinafter referred to as a photosensitive member), and the charged photosensitive member. Is exposed so as to correspond to the original image or the input image signal to form an electrostatic latent image. Next, the electrostatic latent image is developed using a developing device to form a toner image, the toner image is transferred to a transfer material using a transfer device, and then the toner image is transferred to the transfer material using a fixing device. The image is fixed and output as a fixed image. Further, the toner remaining on the surface of the photoreceptor is removed using a cleaning device. When the toner is removed, the cleaning member is pressed against the photosensitive member to stop the toner and is scraped off and collected in a waste toner container. However, a blade-type cleaning member is used. Since such a cleaning member is brought into direct contact with the photosensitive member, the toner collecting property is excellent, the cleaning property is maintained for a long time, and the good cleaning property is exhibited even when a large amount of toner remains. However, there are problems such as wear of the photosensitive member (shortening of life), treatment of waste toner, and the necessity of processing the waste toner, and the fact that the image forming apparatus inevitably becomes large due to the provision of the cleaning device.

  Accordingly, simultaneous development cleaning (or cleaner-less) is known as a waste toner-less system from the viewpoints of ecology, life of a photoreceptor, downsizing of an image forming apparatus, effective use of toner, and the like. In the simultaneous cleaning for development, the toner remaining on the photoconductor after transfer is subjected to fog removal bias (difference between the DC voltage applied to the developing device and the surface potential of the photoconductor, the fog removal potential difference) during the subsequent development. It is a method of collecting by applying. This method is a toner recycling process in which the toner remaining on the photoconductor after transfer is removed from the photoconductor using a developing device (developing device), collected in the developing device, and reused. is there. As a result, the remaining toner is collected in the developing device and reused after the next step, so that waste toner can be eliminated and maintenance can be facilitated. In addition, since it is cleaner-free, there are great advantages in terms of space, and the image forming apparatus can be downsized. However, in the simultaneous development cleaning, a reversal development in which the polarity of the toner and the charging polarity of the photoconductor are the same polarity is used as a developing method. For this reason, it is impossible in principle to apply development simultaneous cleaning to a conventional analog copying machine using regular development. In addition, when a laser or LED array is used as the exposure means, it is impossible in principle to apply simultaneous development cleaning to so-called back scanning in which a portion corresponding to the background portion is exposed.

  For this reason, simultaneous development cleaning that can be applied to a system using regular development in which the charging polarity of the toner and the charging polarity of the photosensitive member are opposite polarities is desired. For example, Patent Document 1 discloses an image carrier. Simultaneous development cleaning using elastic deformation of the body is disclosed. However, it is difficult to maintain high-quality image quality over the long term.

  Reference 2 discloses a first charging unit that charges the image carrier after transfer to a polarity opposite to the charging polarity of the toner image, an image carrier after charging by the first charging unit and before development by the developing unit. An image forming apparatus including a second charging unit that charges the residual toner to the same polarity as the charging polarity of the toner image without changing the polarity of the potential is disclosed. However, since there are two charging means, it is necessary to increase the size of the apparatus by the size of the members.

Further, in the simultaneous development cleaning without using a cleaning device, it is essential to rub the surface of the photoreceptor with the toner and the toner carrier. When used for a long period of time, the deterioration of the toner, the surface of the toner carrier, Deterioration or wear of the surface of the photoreceptor is likely to occur. In addition, in the simultaneous development cleaning with a high process speed, it is possible to control the charging of the toner before collection in order to improve the recoverability of the toner remaining on the photoconductor after the transfer, and to maintain the development stability when the collected toner is reused. It is insufficient.
JP 2001-175084 A Japanese Patent No. 3155915

  SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, the present invention provides an image forming apparatus and an image forming apparatus capable of suppressing toner remaining on an image carrier after transfer for a long time and forming a high-quality image. It is an object to provide a method and a process cartridge used in the image forming apparatus.

  The invention according to claim 1 is an image forming apparatus of a regular development system, and forms an electrostatic latent image on the image carrier, charging means for charging the image carrier, and the charged image carrier. An electrostatic latent image forming means and a developing means having a plurality of developing units for developing the electrostatic latent image with toner. The image carrier has an area where the electrostatic latent image is formed in the static image. The ratio of the transit time of the image carrier to the time from the formation of the electrostatic latent image to the development is 1.0 to 1.3.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the electrostatic latent image forming unit includes a scanning optical unit that scans a plurality of laser beams on the image carrier. And

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the scanning optical means has three or more surface emitting lasers.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the scanning optical means has a two-dimensional array including the three or more surface emitting lasers.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the image carrier is a general formula.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、アルキル基、アルコキシル基、シアノ基又はハロゲン基であり、Ｘ及びＹは、それぞれ独立に、一般式

Wherein R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a cyano group or a halogen group, and X and Y are each independently a general formula

（式中、Ｒ_３は、水素原子、アリール基又はアルキル基であり、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７及びＲ_８は、それぞれ独立に、水素原子、水酸基、アルキル基、アルコキシル基、シアノ基、ジアルキルアミノ基、ニトロ基、ハロゲン基又はハロアルキル基であり、Ｚは、置換若しくは無置換の炭素環式芳香族基又は置換若しくは無置換の複素環式芳香族基である。）
で示される官能基である。）
で示される化合物を含有する感光層を有することを特徴とする。

(Wherein R ₃ is a hydrogen atom, an aryl group or an alkyl group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxyl group, A cyano group, a dialkylamino group, a nitro group, a halogen group, or a haloalkyl group, and Z is a substituted or unsubstituted carbocyclic aromatic group or a substituted or unsubstituted heterocyclic aromatic group.
It is a functional group shown by. )
It has the photosensitive layer containing the compound shown by these.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the X and Y are different.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the image carrier has a diffraction angle 2θ in an X-ray diffraction spectrum using a characteristic X-ray of CuKα. ± 0.2 ° has peaks at 9.4 °, 9.6 ° and 24.0 °, the peak at 27.2 ° has the highest intensity, and the peak at 7.3 ° has the smallest angle Photosensitive layer containing a crystal of titanyl phthalocyanine in which no peak exists between the peak at 7.3 ° and the peak at 9.4 °, and no peak at 26.3 ° It is characterized by having.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the image carrier has a protective layer as an outermost layer.

The invention according to claim 9 is the image forming apparatus according to claim 8, wherein the protective layer contains a filler having a specific resistance of 10 ¹⁰ Ω · cm or more.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth or ninth aspect, the protective layer includes at least a trifunctional or higher functional radical polymerizable compound having no charge transport structure, and a charge transport structure. It is formed by hardening | curing the monofunctional radically polymerizable compound which has this.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to the tenth aspect, the monofunctional radically polymerizable compound having the charge transporting structure has the general formula:

（式中、Ｒ_１は、水素原子、ハロゲン基、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアルコキシル基、シアノ基、ニトロ基、一般式
−ＣＯＯＲ_２
（式中、Ｒ_２は、水素原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基又は置換若しくは無置換のアリール基である。）
で示される官能基、一般式
−ＣＯＹ
（式中、Ｙは、ハロゲン基である。）
で示される官能基又は一般式
−ＣＯＮＲ_３Ｒ_４
（式中、Ｒ_３及びＲ_４は、それぞれ独立に、水素原子、ハロゲン基、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基又は置換若しくは無置換のアリール基である。）
で示される官能基であり、Ａｒ_１及びＡｒ_２は、それぞれ独立に、置換又は無置換のアリーレン基であり、Ａｒ_３及びＡｒ_４は、それぞれ独立に、置換又は無置換のアリール基であり、Ｘは、単結合、置換若しくは無置換のアルキレン基、置換若しくは無置換のシクロアルキレン基、置換若しくは無置換のオキシアルキレン基、オキシ基、チオ基又はビニレン基であり、Ｚ_１は、置換若しくは無置換のアルキレン基、置換若しくは無置換のオキシアルキレン基又は一般式
−ＣＯＯＲ_６−
（式中、Ｒ_６は、アルキレン基である。）
で示される官能基であり、ｍは、０以上３以下の整数であり、ｎは、０又は１である。）
で示される化合物を一種以上含有することを特徴とする。

(Wherein R ₁ represents a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxyl group, a cyano group, a nitro group, Group, general formula -COOR ₂
(Wherein R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
A functional group represented by the general formula -COY
(In the formula, Y is a halogen group.)
Or a functional group represented by the general formula —CONR ₃ R ₄
(Wherein R ₃ and R ₄ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted arylene group, Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted aryl group, X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted oxyalkylene group, an oxy group, a thio group, or a vinylene group, and Z ₁ is a substituted or unsubstituted group. A substituted alkylene group, a substituted or unsubstituted oxyalkylene group, or a general formula —COOR ₆ —
(In the formula, R ₆ is an alkylene group.)
, M is an integer of 0 or more and 3 or less, and n is 0 or 1. )
It contains one or more compounds represented by the following.

  According to a twelfth aspect of the present invention, in the image forming apparatus according to the tenth aspect, the monofunctional radically polymerizable compound having the charge transporting structure has a general formula:

（式中、Ｒ_７は、水素原子又はメチル基であり、Ｒ_８及びＲ_９は、それぞれ独立に、炭素数が１以上６以下のアルキル基であり、ｓ及びｔは、それぞれ独立に、０以上３以下の整数であり、Ｚ_２は、単結合、メチレン基、エチレン基又は構造式

(Wherein R ₇ is a hydrogen atom or a methyl group, R ₈ and R ₉ are each independently an alkyl group having 1 to 6 carbon atoms, and s and t are each independently 0 It is an integer of 3 or less and Z ₂ is a single bond, a methylene group, an ethylene group or a structural formula

で示される官能基であり、Ｐｈは、フェニレン基であり、ｏ、ｐ及びｑは、それぞれ独立に、０又は１である。）
で示される化合物を一種以上含有することを特徴とする。

, Ph is a phenylene group, and o, p, and q are each independently 0 or 1. )
It contains one or more compounds represented by the following.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the tenth to twelfth aspects, heating or light irradiation is performed when the curing is performed.

  According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, there is no cleaning means for cleaning the image carrier.

  According to a fifteenth aspect of the present invention, there is provided a process cartridge that is detachable from the main body of the image forming apparatus according to any one of the first to fourteenth aspects, and includes at least the image carrier. .

  The invention according to claim 16 is an image forming method of a regular development system, wherein a charging step for charging the image carrier and formation of an electrostatic latent image on the charged image carrier are formed. And a plurality of development steps for developing the electrostatic latent image with toner, and the image carrier has an area where the electrostatic latent image is formed and the development after the electrostatic latent image is formed. The ratio of the transit time of the image carrier to the time until it is applied is 1.0 or more and 1.3 or less.

  According to a seventeenth aspect of the present invention, in the image forming method according to the sixteenth aspect, an electrostatic latent image is formed on the charged image carrier with a resolution of 1200 dpi or more.

  According to an eighteenth aspect of the present invention, in the image forming method according to the sixteenth or seventeenth aspect, when the electrostatic latent image is formed, a plurality of laser beams are scanned on the image carrier. To do.

  According to a nineteenth aspect of the present invention, in the image forming method according to the eighteenth aspect, a plurality of laser beams are scanned on the image carrier using three or more surface emitting laser arrays. .

  According to a twentieth aspect of the present invention, in the image forming method according to the nineteenth aspect, a plurality of laser light beams are scanned on the image carrier using a two-dimensional array including three or more surface-emitting laser arrays. It is characterized by that.

  According to the present invention, an image forming apparatus and an image forming method capable of suppressing toner remaining on an image carrier after transfer for a long period of time and forming a high quality image, and the image forming apparatus are used. Process cartridges can be provided.

  Next, the best mode for carrying out the present invention will be described.

An image forming apparatus according to the present invention is an image forming apparatus of a regular development system, and includes an image carrier, a charging unit that charges the image carrier, and an electrostatic that forms an electrostatic latent image on the charged image carrier. A latent image forming means and a developing means having a plurality of developing units for developing the electrostatic latent image with toner, and the image carrier has an area where the electrostatic latent image is formed and the electrostatic latent image is formed The ratio t _T / T _ed of the transit time t _T of the image carrier to the process time T _ed from development to development is 1.0 to 1.3. As a result, toner remaining on the image carrier after the transfer can be suppressed for a long time. Furthermore, the image carrier can be uniformly charged, and a high-quality image can be formed even in an image forming apparatus that does not have a cleaning device that collects toner remaining on the image carrier after transfer.

  In the present invention, the electrostatic latent image forming means is preferably a multi-beam scanning optical system having scanning optical means for scanning a plurality of laser beams on the image carrier. As a result, high-quality images can be formed on a long-term basis even with a high-speed machine having a high process speed. The image carrier preferably has a protective layer as the outermost layer. Thereby, abrasion resistance can be improved. Therefore, according to the image forming apparatus of the present invention, it is possible to realize high image quality, high image forming speed and downsizing of the apparatus, and an image with good quality even when the image forming process is repeated. Is obtained. For example, according to the image forming apparatus of the present invention, a high-resolution image having a recording density of 1200 dpi (dot / inch) or more can be formed over a long period of time.

As an exposure means used in an image forming apparatus such as a laser beam printer or a digital copying machine, a laser beam corresponding to an image signal is output from a semiconductor laser, and reflected by a rotating polygon mirror (polygon mirror). There is a means for forming an electrostatic latent image by irradiating the surface. In the case of such an exposure means using a laser beam, it is necessary to increase the scanning speed of the laser beam in order to realize high image quality and high speed of the output image with a single laser beam. However, since the rotational speed of the rotary polygon mirror is limited, it is difficult to achieve high definition and high speed of the output image. Therefore, a method of scanning a plurality of laser beams on the photosensitive member (hereinafter referred to as a multi-beam method) is known. The multi-beam image forming apparatus is considered to be effective for speeding up the image forming process because of the following advantages (1) to (3).
(1) When n (n is an integer greater than or equal to 2) laser beams are used, the scanning speed and the printing speed of the laser beam are set equal to the case where one laser beam is used. Can be increased n times, and a high-resolution image can be formed.
(2) When n (n is an integer of 2 or more) laser beams are used, the scanning speed of the laser beam and the density of the scanning lines are set equal to the case where one laser beam is used. It becomes possible to increase the printing speed by n times.
(3) When n (n is an integer of 2 or more) laser beams are used, each laser beam is set when the print speed and the scanning density of the laser beam are set equal to those when one laser beam is used. The rotation speed of the rotary polygon mirror for forming an electrostatic latent image is increased by 1 / n times by lowering the scanning speed of the laser beam, that is, by reflecting the laser beam and irradiating the surface of the photosensitive member with the reflected beam. Therefore, the mechanism for rotationally driving the rotary polygon mirror can be simplified and the cost can be reduced.

  As such a multi-beam type image forming apparatus, an apparatus having an edge emitting laser whose light resonating direction is parallel to the substrate surface is known (for example, see JP-A-2002-303997). . However, since it is difficult to finely adjust the scanning line interval in the edge-emitting laser, it is not easy to increase the number of laser beams, and image quality improvement and image formation speed increase are insufficient. It may become.

  As a multi-beam type image forming apparatus, one having a surface emitting laser (VCSEL) in which the direction of light resonance is perpendicular to the substrate surface is known (for example, Japanese Patent Laid-Open No. 5-294005). reference). Such an image forming apparatus can increase the number of scanning laser beams (the number of scanning lines simultaneously scanned by the laser beam). At this time, it is preferable to use three or more VCSELs as the light source, and it is more preferable to use a two-dimensional array including three or more VCSELs. As a result, when three or more laser beams are deflected and simultaneously scanned on the photosensitive member, three or more scanning lines can be scanned in one main scan, resulting in higher image quality. In addition, an increase in image forming speed can be achieved.

On the other hand, in the organic photoreceptor, in general, in the region where the process time T _ed is long, the potential of the exposed portion at the time of development is almost constant, but when T _ed is shortened, the exposed portion at the time of development from a certain point (bending point). The potential increases. When the relationship of the potential of the exposed portion during development with respect to the process time T _ed is obtained, a bending point exists as shown in FIG. For convenience, the process time T _ed at this inflection point is referred to as a transit time t _T. From FIG. 1, it can be seen that the shorter the process time T _ed , the more rapidly the potential of the exposed portion during development by shortening the process time T _ed becomes shorter. In the present invention, by setting t _T / T _ed to 1.0 to 1.3, toner transferability can be improved, and output of defective images such as fogging can be suppressed. Such a defective image is often eliminated by increasing the printing speed, and is considered to be caused by the time responsiveness of light attenuation of the surface potential of the photoreceptor.

The time responsiveness of light attenuation of the surface potential of the photoconductor is evaluated using a photoconductor characteristic evaluation apparatus (see Japanese Patent Application Laid-Open No. 2000-275872). Thereby, the process time T _ed can be set to evaluate the relationship (light attenuation curve) of the potential of the exposed portion during development with respect to the exposure amount of the photosensitive member output from the laser diode (LD). Further, it is possible to evaluate the relationship between the process time T _ed and the potential of the exposed portion during development, that is, the time response of light attenuation of the surface potential of the photoreceptor.

  A time-of-flight (TOF) method is also known as a method for evaluating the time responsiveness of the photoattenuation of the surface potential of the photoreceptor (for example, JP-A-10-115944 and JP-A-2001-312077). See the official gazette). However, the charge transport in the photoconductor and the charge transport by the TOF method are different in that the former changes the electric field strength in the layer every moment after exposure, whereas the latter has a constant electric field strength. . Further, the influence of charge generation from the charge generation layer upon exposure and injection behavior from the charge generation layer to the charge transport layer on the charge transport in the multilayer photoreceptor is not reflected in the TOF method.

  Further, as a method for directly evaluating the time responsiveness of light attenuation of the surface potential of the photosensitive member, a xerographic time-of-flight (XTOF) method is also known (see, for example, Japanese Patent Laid-Open No. 2000-305289). This method is a method of measuring a change in the surface potential of a photoconductor after irradiation with pulsed light using a high-speed surface potentiometer, but the light source used for the measurement is often different from the exposure means of the image forming apparatus. .

FIG. 2 shows an example of an apparatus for evaluating the time response of light attenuation of the surface potential of the photoreceptor. This evaluation apparatus includes a photoconductor 1 to be evaluated, a charging device 2 (a scorotron charger), an LD and an ND filter, and the surface potential of the exposure device 3 and the photoconductor 1 that irradiates the photoconductor 1 with (exposure) light 3L. An electrometer 13 (potential probe) is measured. The electrometer 13 is disposed at a place corresponding to a developing device in an actual machine. The photoreceptor 1 is an electrophotographic photoreceptor having a diameter of 30 mm that is rotationally driven in the direction of an arrow. Further, the photoconductor 1 is designed to reach a position where the potential is measured by the electrometer 13 from the exposure position where the light 3L is irradiated by rotating the photoreceptor 1 by 45 °. Therefore, when the moving speed of the surface of the photoreceptor 1 is set to be 270 mm / second, the process time T _ed is
30π × (45 ° / 360 °) / 270 × 1000≈44 [milliseconds]
It becomes.

Hereinafter, a case where a positive toner, that is, a positive toner is applied to the photoconductor having the time response of the light attenuation of the surface potential shown in FIG. 1 will be described. When the process time T _ed is equal to or shorter than the transit time t _T, that is, when t _T / T _ed is equal to or greater than 1, development is performed in a state where the potential (absolute value) of the exposed portion of the photoreceptor is not sufficiently lowered. For this reason, the positive toner is developed with insufficient development contrast. At this time, in an image forming apparatus with a high process speed, the potential of the exposed portion decreases while being affected by an electric field or the like between development and transfer. As a result, the Coulomb force acting between the developed positive toner and the photosensitive member at the time of transfer is lower than at the time of development. For this reason, the toner is easily transferred onto the transfer medium, charging is stably performed, and the problems associated with downsizing of the image forming apparatus of the regular development system can be solved. Furthermore, by setting t _T / T _ed to 1.3 or less, the toner can be more effectively transferred onto the transfer target.

In the present invention, the toner is developed on the unexposed portion of the photoconductor and transferred to the transfer target. By setting t _T / T _ed to 1.0 to 1.3, Since the coulomb force of the toner is reduced, the amount of toner transferred to the transfer target can be increased, and the transferability of the toner can be stably controlled. Furthermore, it can be made cleaner-less without a cleaning step for cleaning the photosensitive member between the transfer step and the next charging step.

  FIG. 3 shows a one-drum type full-color printer as an example of the image forming apparatus of the present invention. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals and description thereof is omitted. The image forming apparatus 100 is a regular development type laser beam printer (digital copying machine) using a transfer type electrophotographic process. The image forming apparatus 100 includes a photoconductor 1, and the photoconductor 1 can be rotated in a direction of an arrow A at a predetermined rotation speed by a driving device (not shown). Further, a charging device 2, a developing device 4 and an intermediate transfer member 5 are arranged along the rotation direction of the photosensitive member 1. The charging device 2 is a contact charging method, and includes a charging roller that uniformly charges the outer peripheral surface of the photosensitive member 1 to a polarity (negative polarity) opposite to that of the toner. An exposure device 3 (laser beam scanning device) is disposed substantially above the charging device 2. As will be described in detail later, the exposure device 3 modulates a plurality of laser beams emitted from a light source according to an image to be formed, deflects them in the main scanning direction, and is charged by the charging device 2. 1 is scanned in parallel with the axis of the photoreceptor 1 to form an electrostatic latent image. Further, the developing device 4 develops the electrostatic latent image formed on the photoreceptor 1 with a developer of each color of yellow (Y), magenta (M), cyan (C), and black (Bk). 4b, 4c and 4d. The intermediate transfer member 5 is an endless intermediate transfer belt and is wound around rollers 10, 11 and 12, and is arranged so that the outer peripheral surface is in contact with the outer peripheral surface of the photoreceptor 1. The rollers 10, 11, and 12 rotate when a driving force of a motor (not shown) is transmitted to rotate the intermediate transfer member 5 in the direction of arrow B. Further, a transfer device 6 having a transfer roller is disposed on the opposite side of the photosensitive member 1 with the intermediate transfer member 5 interposed therebetween. The toner image formed on the outer peripheral surface of the photoreceptor 1 is primarily transferred to the image forming surface of the intermediate transfer member 5 by the transfer device 6. As a result, the charging, exposure, development, and primary transfer processes are sequentially performed as the photosensitive member 1 rotates, and the toner images of the respective colors are superimposed on the intermediate transfer member 5. A transfer device 7 having a transfer roller is arranged on the opposite side of the roller 12 with the intermediate transfer member 5 interposed therebetween. A transfer medium P (paper) conveyed by a roller (not shown) is sent between the intermediate transfer member 5 and the transfer device 7, and a toner image formed on the image forming surface of the intermediate transfer member 5 is transferred to the transfer device 7. Is secondarily transferred to the transfer medium P. A fixing device 8 having a pair of fixing rollers is disposed downstream of the transfer device 7 in the conveyance direction of the transfer medium P, and the transfer medium P to which the toner image has been transferred has the toner image being a fixing device. After being melted and fixed by the image forming apparatus 8, the image forming apparatus 100 is discharged out of the body of the image forming apparatus 100 and placed on a paper discharge tray (not shown). Further, on the opposite side of the developing device 4 with the photoconductor 1 interposed therebetween, a static eliminating device 9 that neutralizes the outer peripheral surface of the photoconductor 1 is disposed. As a result, when the photoreceptor 1 is repeatedly used, a phenomenon that the residual potential of the photoreceptor 1 is brought into the next cycle can be suppressed, so that the image quality can be further improved.

  Next, development and primary transfer in the image forming apparatus 100 will be described. The electrostatic latent image on the photosensitive member 1 is developed with a yellow (Y) developer at a position where the photosensitive member 1 faces the developing unit 4 a in the developing device 4. Next, the photosensitive member 1 is rotated by a driving device (not shown), and the yellow (Y) toner image on the photosensitive member 1 is opposite in polarity to the toner at a position where the photosensitive member 1 faces the intermediate transfer member 5 ( The image is primarily transferred onto the driven intermediate transfer member 5 by the transfer device 6 to which a negative transfer bias is applied. Here, the developing device 4 is rotated about 90 ° by a driving means (not shown) to prepare for developing magenta (M). Further, similar to yellow (Y), magenta (M) development and primary transfer are performed. At this time, control is performed so that the yellow (Y) toner image and the magenta (M) toner image are superimposed on the intermediate transfer member 5. Next, development and primary transfer are performed on cyan (C) and black (Bk) in the same manner as described above, and yellow (Y), magenta (M), cyan (C) and black ( Bk) four color toner images are superimposed.

  FIG. 4 shows another example of the image forming apparatus of the present invention. The image forming apparatus 200 has the same configuration as the image forming apparatus 100 except that the developing units 4a, 4b, 4c, and 4d are sequentially arranged in the rotation direction of the photoreceptor 1.

  Next, development in the image forming apparatus 100 will be described. The electrostatic latent image on the photosensitive member 1 is developed with a yellow (Y) developer at a position where the photosensitive member 1 faces the developing unit 4 a in the developing device 4. Next, the photosensitive member 1 is rotated by a driving device (not shown) to prepare for the development of magenta (M). Further, magenta (M) is developed in the same manner as yellow (Y). At this time, control is performed so that the yellow (Y) toner image and the magenta (M) toner image are superimposed on the photosensitive member 1. Next, cyan (C) and black (Bk) are also developed in the same manner as above, and yellow (Y), magenta (M), cyan (C), and black (Bk) 4 are formed on the photoreceptor 1. Color developers are superimposed.

  In this way, by using the image forming apparatus having the photosensitive member 1 having the above-described characteristics together with the multi-beam type exposure device 3 that forms a latent electrostatic image by scanning a plurality of laser beams on the photosensitive member, It is possible to improve the image quality, increase the image forming speed, and reduce the size of the apparatus, and an image with good image quality can be obtained even if the image forming process is repeated over a long period of time.

  Next, components of the image forming apparatus of the present invention will be described.

  The exposure apparatus includes a surface emitting laser array (not shown) that emits n (n is an integer of 2 or more) laser beams. Note that a surface emitting laser array in which surface emitting lasers are arrayed can be configured to emit, for example, several tens of laser beams. It is also possible to arrange them (for example, in a matrix).

  As a two-dimensional array in which light emitting points that are laser beam generation sources are two-dimensionally arranged, for example, nine light emitting points of three rows in the main scanning direction and three columns in the sub-scanning direction are arranged at predetermined intervals. The thing arrange | positioned two-dimensionally is mentioned. In addition, the light emitting points arranged in the main scanning direction are shifted in steps by one step in the sub scanning direction, with the distance obtained by dividing the distance from the light emitting points arranged in the sub scanning direction into three equal parts. Is arranged. In other words, if it is limited to the sub-scanning direction, a light emitting point is arranged for each step. In this way, by arranging the light emission points in stages in the sub-scanning direction, all the light emission points can scan different scanning lines. Thereby, the laser array can simultaneously scan nine scanning lines.

  The light emitting points of the surface emitting laser array are preferably arranged in 3 rows or more, 3 columns or more, more preferably 4 rows or more, 4 columns or more, and particularly preferably 6 rows or more, 6 columns or more. As a result, it is possible to more reliably realize higher image quality (higher resolution) and higher image formation speed of the image to be formed.

  Further, it is preferable that the exposure apparatus scans two or more laser beams independently on the photoconductor, but from the viewpoint of more effectively achieving high image quality and high speed, the number of beams is preferably 3 or more. preferable.

  As a result, the surface emitting laser array emits n laser beams that are turned on and off at a timing corresponding to the modulation signal, and whose light amount corresponds to the drive amount setting signal. By scanning the surface, an electrostatic latent image is formed on the outer peripheral surface of the photoreceptor.

  As a charging method of the charging device, a contact charging method using a charging roll, a charging brush, a charging film, a charging tube, or the like, or a non-contact method such as corotron or scorotron can be used. Among them, a contact charging type charging device such as a device in which the charging device is disposed close to the surface of the photoreceptor with an appropriate gap is preferable from the viewpoint of miniaturization of the image forming apparatus. In the contact charging method, the surface of the photoconductor is charged by applying a voltage to a conductive member brought into contact with the surface of the photoconductor. Examples of the shape of the conductive member include a brush shape, a blade shape, a pin electrode shape, and a roller shape, and a roller shape is preferable. When the roller-like conductive member is brought into contact with the photosensitive member, it rotates at the same peripheral speed as that of the photosensitive member without any driving means, and functions as a charging device. The driving means may be attached to the roller-like conductive member and rotated at a peripheral speed different from that of the photosensitive member. The voltage applied to the conductive member may be either direct current or alternating current, or may be a superposition of direct current voltage and alternating current voltage.

  In the present invention, since the photoreceptor has excellent mechanical strength, excellent durability is exhibited even when the contact charging method is used.

  A known developing device can be used as the developing device. As the developer, a one-component developer composed of toner, a two-component developer composed of toner and carrier, and the like can be used, but a two-component developer is preferable from the viewpoint of improving image quality. The toner is not particularly limited, and for example, an irregular toner by a pulverization method or a spherical toner by a polymerization method can be used.

  Examples of the transfer device include known transfer chargers such as a contact transfer charger using a belt, a roller, a film, a rubber blade, etc., a scorotron transfer charger using corona discharge, and a corotron transfer charger. Among these, a contact type transfer charger is preferable from the viewpoint of excellent transfer charge compensation capability. In the present invention, a peeling charger or the like can be used in combination with the transfer charger. As a transfer method, for example, a direct transfer method in which a toner image on a photoconductor is directly transferred to a transfer medium, or an intermediate in which a toner image on a photoconductor is transferred to an intermediate transfer body and then transferred to a transfer medium. A transfer method is mentioned.

  Examples of the static eliminator include a tungsten lamp and an LED. Further, examples of the light quality used in the light static elimination process include white light such as a tungsten lamp and red light such as LED light. The intensity of the irradiation light in the photostatic process is preferably about several to 30 times the amount of light showing the half exposure sensitivity of the photoreceptor.

  In this manner, image formation is repeatedly performed by sequentially performing charging, exposure, development, transfer, and charge removal steps. Here, since the photoconductor having the above-described characteristics has achieved sufficiently high wear resistance and electrical characteristics, even when used with a contact charging device, image quality defects such as fogging are eliminated. Occurrence can be suppressed. Therefore, even when used repeatedly over a long period of time, it is possible to obtain an image forming apparatus capable of sufficiently suppressing wear of the photoreceptor and capable of forming a full color image with excellent image quality at high speed. It is done.

  Note that the image forming apparatus of the present invention is not limited to the configuration shown in FIGS. 3 and 4 and may include, for example, a process cartridge. By using the process cartridge, maintenance can be easily performed.

  The process cartridge of the present invention has at least a photoreceptor and is mounted on the main body of the image forming apparatus of the present invention.

  5 and 6 show an example of the process cartridge of the present invention. 5 and 6, the same components as those in FIGS. 2 to 4 are denoted by the same reference numerals and description thereof is omitted. The process cartridge 300 uses an attachment rail (not shown) for the photosensitive member 1, the charging device 2 (scorotron charger), the developing device 4, the intermediate transfer member 5, the transfer device 6, and the openings 301 and 302 for exposure. Are combined and integrated. Similarly, in the process cartridge 400, the photosensitive member 1, the charging device 2, the developing device 4, the intermediate transfer member 5, the transfer device 6, and the openings 401 and 402 for exposure are combined using an attachment rail (not shown). , Integrated. Further, the process cartridges 300 and 400 are detachable from the exposure apparatus 3, the transfer apparatus 7, the fixing apparatus 8, the static eliminator 9, and the main body of the image forming apparatus including other components not shown. The image forming apparatus is configured together with the main body of the image forming apparatus.

  7 and 8 show an example of the photoreceptor used in the present invention. In the photoreceptor used in the present invention, at least a photosensitive layer is formed on a conductive substrate. The photosensitive layer is either a single layer type or a laminated type in which a charge generation layer and a charge transport layer are laminated. May be. In the photoreceptor shown in FIG. 7, an undercoat layer 501, a photosensitive layer 504, and a protective layer 505 are sequentially laminated on a conductive support 500. In the photoreceptor shown in FIG. 8, an undercoat layer 501, a charge generation layer 502, a charge transport layer 503, and a protective layer 505 are sequentially stacked on a conductive support 500. In such a photoreceptor, since the protective layer 505 is formed on the outermost layer, the wear resistance is improved, the fluctuation of the film thickness can be suppressed, and a uniform image can be obtained in the long term.

  Next, constituent elements of the photoreceptor will be described.

  The charge generation layer 502 contains a charge generation material, and may further contain a binder resin as necessary. Examples of the charge generation material include 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, and diphenylamine skeletons. Azo pigments, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, distyrylcarbazole skeleton Azo pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and Methine pigments, indigoid pigments, include bis-benzimidazole pigments may be used alone or in combination. Above all, general formula

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、アルキル基、アルコキシル基、シアノ基又はハロゲン基であり、Ｘ及びＹは、それぞれ独立に、一般式

Wherein R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a cyano group or a halogen group, and X and Y are each independently a general formula

（式中、Ｒ_３は、水素原子、アリール基又はアルキル基であり、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７及びＲ_８は、それぞれ独立に、水素原子、水酸基、アルキル基、アルコキシル基、シアノ基、ジアルキルアミノ基、ニトロ基、ハロゲン基又はハロアルキル基であり、Ｚは、置換若しくは無置換の炭素環式芳香族基又は置換若しくは無置換の複素環式芳香族基である。）
で示されるカプラー残基である。）
で示されるアゾ系顔料、特に、ＸとＹが相異なるアシンメトリーなアゾ系顔料が好ましい。また、フタロシアニン系顔料、特に、ＣｕＫαの特性Ｘ線を用いたＸ線回折スペクトルにおいて、回折角２θ±０．２°が９．４゜、９．６゜及び２４．０゜にピークが存在し、２７．２°に存在するピークの強度が最大であり、７．３°に最小角度のピークが存在し、７．３°に存在するピーク及び９．４゜に存在するピークの間にピークが存在せず、２６．３゜にピークが存在しないチタニルフタロシアニンの結晶が好ましい。

(Wherein R ₃ is a hydrogen atom, an aryl group or an alkyl group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxyl group, A cyano group, a dialkylamino group, a nitro group, a halogen group, or a haloalkyl group, and Z is a substituted or unsubstituted carbocyclic aromatic group or a substituted or unsubstituted heterocyclic aromatic group.
It is a coupler residue shown by. )
In particular, an asymmetric azo pigment in which X and Y are different is preferable. In addition, in the X-ray diffraction spectrum using characteristic X-rays of phthalocyanine pigments, particularly CuKα, the diffraction angles 2θ ± 0.2 ° have peaks at 9.4 °, 9.6 ° and 24.0 °. , Peak intensity at 27.2 ° is maximum, peak at 7.3 ° is at minimum angle, peak between peak at 7.3 ° and peak at 9.4 ° Is preferred, and crystals of titanyl phthalocyanine having no peak at 26.3 ° are preferred.

  As the binder resin, for example, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, Vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, and other thermoplastic resins or thermosetting resins, polyethylene, polypropylene, polyamide, phenoxy Addition polymerization resins such as resins, polyaddition resins, polycondensation resins, styrene-acrylic copolymers, vinyl chloride-vinyl acetate-maleic anhydride Insulating copolymer of the polymer such as poly (N- vinylcarbazole) polymer organic semiconductor such as. These may be used alone or in combination. In addition, it is preferable that it is 0-500 mass parts with respect to 100 mass parts of charge generation substances, and, as for the addition amount of binder resin, 10-300 mass parts is more preferable.

  The charge generation layer 502 is formed by applying a charge generation material, a solvent, and, if necessary, a solution or dispersion containing a binder resin onto the conductive support 500 and drying. The charge generation layer 502 preferably has a thickness of 0.01 to 5 μm, and more preferably 0.1 to 2 μm.

  Examples of the method for dissolving or dispersing the charge generation material and the binder resin in a solvent include a ball mill, an attritor, and a sand mill. In this case, it is preferable to carry out the conditions under which the crystal form of the charge generating material does not change due to the dispersion process. The charge generation material preferably has an average particle size of 0.5 μm or less, more preferably 0.3 μm or less, and particularly preferably 0.15 μm or less.

  Examples of the solvent include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, and the like. You may use together. Among these, non-halogen solvents are preferable from the viewpoint of reducing environmental load. Examples of the non-halogen solvent include cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, aromatic hydrocarbons such as toluene and xylene, and derivatives thereof.

  Examples of the coating method for the charge generation layer 502 include a spray coating method, a beam coating method, and a dipping coating method.

  The charge transport layer 503 contains a charge transport material (a hole transport material or an electron transport material) and a binder resin. Examples of the hole transport material include poly (N-vinylcarbazole) and derivatives thereof, poly (γ-carbazolylethyl glutamate) and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, and polysilane. , Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styryl Anthracene derivative, pyrazoline derivative, divinylbenzene derivative, hydrazone derivative, indene derivative, butadiene derivative, pyrene derivative, bisstilbene derivative, enamine derivative Examples of such an electron donating substance include two or more of them. Examples of the electron transport material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3, Electron accepting substances such as 7-trinitrodibenzothiophene-5,5-dioxide, benzoquinone derivatives and the like may be mentioned, and two or more kinds may be used in combination.

  As the binder resin, a resin similar to that of the charge generation layer 502 can be used. In addition, it is preferable that the addition amount of a charge transport material is 20-300 mass parts with respect to 100 mass parts of binder resin, and 40-150 mass parts is more preferable.

  The charge transport layer 503 may further contain additives such as a low-molecular compound such as a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, and a leveling agent for the purpose of improving gas barrier properties and environmental resistance. . Two or more of these additives may be used in combination. At this time, it is preferable that the addition amount of a low molecular compound is 0.1 to 50 weight% with respect to a high molecular compound, and 0.1 to 20 weight% is further more preferable. Moreover, it is preferable that the addition amount of a leveling agent is 0.001 to 5 weight% with respect to a high molecular compound.

  The charge transport layer 503 is formed by applying and drying a binder resin, a charge transport material, and, if necessary, a solution or dispersion containing an additive on the charge generation layer 502 and drying. The charge transport layer 503 preferably has a thickness of 5 to 30 μm, and more preferably 10 to 25 μm.

  As a method for dissolving or dispersing the charge transport material, the binder resin, and the additive in the solvent, a method similar to that for the charge generation layer 502 can be used. In addition, as a method for applying the charge transport layer 503, a method similar to that for the charge generation layer 502 can be used.

  The photosensitive layer 504 contains the above-described charge generation material, charge transport material (hole transport material, electron transport material), binder resin, and the like. The photosensitive layer 504 may further contain additives such as a low-molecular compound such as a lubricant, a plasticizer, an antioxidant, and an ultraviolet absorber and a leveling agent for the purpose of improving gas barrier properties and environmental resistance. Good. Two or more of these additives may be used in combination. At this time, it is preferable that the addition amount of a low molecular compound is 0.1 to 50 weight% with respect to a high molecular compound, and 0.1 to 20 weight% is further more preferable. Moreover, it is preferable that the addition amount of a leveling agent is 0.001 to 5 weight% with respect to a high molecular compound.

  The photosensitive layer 504 can be formed using a casting method or the like. The film thickness is preferably 5 to 100 μm, and more preferably 10 to 30 μm.

  The protective layer 505 is roughly classified into two types: a filler-dispersed protective layer A and a crosslinked protective film B.

  The protective layer A contains a binder resin, a charge transport material, and a filler (conductive fine particles).

  Examples of the binder resin include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, poly Butylene terephthalate, polycarbonate, polyarylate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride , Polyvinylidene chloride, epoxy resin and the like, and two or more of them may be used in combination. Moreover, you may use together a hardening | curing agent.

  As the charge transporting material, the same materials as those of the charge transporting layer 503 can be used, and among them, a polymer charge transporting material is preferable from the viewpoint of improving the mechanical durability and charge transporting ability of the photoreceptor.

  Examples of the filler include metals or metal oxides such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide-coated titanium oxide, tin-coated indium oxide, antimony-coated tin oxide, or zirconium oxide. Two or more kinds may be used in combination.

  The filler preferably has a volume average particle size of 0.1 to 2 μm, more preferably 0.3 to 1 μm. When the volume average particle size is less than 0.1 μm, the mechanical durability becomes insufficient, and a high-quality image may not be stably formed over a long period of time. The characteristics may be deteriorated, and it may be difficult to form the protective layer A.

The filler preferably has a specific resistance of 10 ¹⁰ Ω · cm or more. Examples of such a filler include alumina, zirconia, titanium oxide, silica, and the like. Among them, α-alumina having a hexagonal close-packed structure and high thermal stability and hardness characteristics has an image quality such as image blur. It is preferable from the viewpoint of suppressing the decrease.

  The specific resistance of the filler is measured using, for example, a measuring apparatus having the same configuration as that described in JP-A-5-94049 (FIG. 1) and JP-A-5-113688 (FIG. 1). can do.

  The filler content in the protective layer A is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. When the content is less than 5% by weight, the abrasion resistance of the photoreceptor may be insufficient, and when it exceeds 50% by weight, the sensitivity of the photoreceptor may be lowered.

  The protective layer A may further contain an additive for the purpose of improving the dispersibility of the filler, the adhesiveness with the binder resin, and the surface smoothness. For improving the dispersibility of the filler, it is preferable to modify the surface of the filler with a coupling agent, a leveling agent, or the like. Furthermore, it is preferable to use a curable resin as the binder resin.

  Moreover, the protective layer A further contains additives such as a low-molecular compound such as a lubricant, a plasticizer, an antioxidant, and an ultraviolet absorber and a leveling agent for the purpose of improving gas barrier properties and environmental resistance. Good. Two or more of these additives may be used in combination. At this time, it is preferable that the addition amount of a low molecular compound is 0.1 to 50 weight% with respect to a high molecular compound, and 0.1 to 20 weight% is further more preferable. Moreover, it is preferable that the addition amount of a leveling agent is 0.001 to 5 weight% with respect to a high molecular compound.

  Here, the lubricant can reduce the friction between the photosensitive member and the charging member, the friction between the photosensitive member and the transfer medium, and reduce the mechanical load on the image forming apparatus. In addition, the releasability of the surface of the photoreceptor is improved, and toner adhesion can be suppressed. As the lubricant, a fluororesin, a silicone resin or a polyolefin resin having a low critical surface tension is preferably used, and a polytetrafluoroethylene resin is particularly preferred. In this case, the content of the lubricant in the protective layer A is preferably 2 to 50% by weight, and more preferably 5 to 40% by weight. If this content is less than 2% by weight, the effect of the lubricant may not be fully exhibited. If it exceeds 50% by weight, the resolution of the image and the sensitivity of the photoreceptor may be lowered.

  The protective layer A is formed by applying a binder resin, a charge transport material, a filler and a solvent, and, if necessary, a dispersion containing an additive onto the charge transport layer 503 or the photosensitive layer 504 and drying. The protective layer A preferably has a thickness of 1 to 15 μm, more preferably 1 to 9 μm. When the film thickness is less than 1 μm, the durability may be insufficient, and a high-quality image may not be stably formed over a long period of time. Sensitivity may decrease.

  As a method of dispersing the binder resin, the charge transport material, the filler, and the additive in the solvent, the same method as that for the charge generation layer 502 can be used. Further, as a method for applying the protective layer A, a method similar to that for the charge generation layer 502 can be used.

  Examples of the solvent include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, halides such as chlorobenzene and dichloromethane, acetic acid Examples thereof include esters such as ethyl and butyl acetate, and two or more of them may be used in combination.

  The protective layer B is formed by curing at least a trifunctional or higher functional radical polymerizable compound not having a charge transport structure and a monofunctional radical polymerizable compound not having a charge transport structure.

  The radical polymerizable functional group of the tri- or higher functional radical polymerizable compound having no charge transporting structure is preferably an acryloyloxy group and / or a methacryloyloxy group. The compound having 3 or more acryloyloxy groups is, for example, an esterification reaction or a transesterification reaction using a compound having 3 or more hydroxyl groups and acrylic acid (salt), an acrylic acid halide, an acrylate ester, or the like. Is obtained. A compound having three or more methacryloyloxy groups can be obtained in the same manner. In addition, the radically polymerizable functional group which the trifunctional or more radically polymerizable compound having no charge transporting structure has may be the same or different.

  Examples of the trifunctional or higher functional radical polymerizable compound having no charge transporting structure include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate. Acrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO Modified glycerol triacrylate, PO modified glycerol triacrylate, (Acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl Modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. Two or more kinds may be used in combination.

  In addition, a trifunctional or higher functional radical polymerizable compound having no charge transport structure has a molecular weight ratio of 250 or less to the number of radical polymerizable functional groups in order to form a dense cross-linked structure in the protective layer B. Is desirable. When this ratio exceeds 250, the protective layer B may be softened and the wear resistance of the photoreceptor may be lowered. For this reason, it is not preferable to use a trifunctional or higher functional radical-polymerizable compound having a modifying group such as HPA, EO, PO, etc. having a large molecular weight.

  Moreover, 20-80% is preferable with respect to the total weight of the protective layer B, and, as for the addition amount of the radically polymerizable compound more than trifunctional which does not have a charge transport structure, 30-70% is more preferable. If this addition amount is less than 20%, the three-dimensional crosslink density of the protective layer B is small, so that the wear resistance may be reduced. If it exceeds 80%, a monofunctional radically polymerizable compound having a charge transporting structure. As a result, the electrical properties may be insufficient.

  The monofunctional radically polymerizable compound having a charge transporting structure preferably has an acryloyloxy group or a methacryloyloxy group. Examples of the charge transporting structure include electrons having a hole transporting structure such as a triarylamine structure, a hydrazone structure, a pyrazoline structure, and a carbazole structure, or a condensed polycyclic quinone structure, a diphenoquinone structure, a cyano group, and a nitro group. An electron transporting structure such as an attractive aromatic ring can be mentioned, among which a triarylamine structure is preferable.

  In the present invention, the monofunctional radically polymerizable compound having a charge transport structure is represented by the general formula (1).

（式中、Ｒ_１は、水素原子、ハロゲン基、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアルコキシル基、シアノ基、ニトロ基、一般式
−ＣＯＯＲ_２
（式中、Ｒ_２は、水素原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基又は置換若しくは無置換のアリール基である。）
で示される官能基、一般式
−ＣＯＹ
（式中、Ｙは、ハロゲン基である。）
で示される官能基又は一般式
−ＣＯＮＲ_３Ｒ_４
（式中、Ｒ_３及びＲ_４は、それぞれ独立に、水素原子、ハロゲン基、置換若しくは無置換のアルキル基、置換若しくは無置換のアラルキル基又は置換若しくは無置換のアリール基である。）
で示される官能基であり、Ａｒ_１及びＡｒ_２は、それぞれ独立に、置換又は無置換のアリーレン基であり、Ａｒ_３及びＡｒ_４は、それぞれ独立に、置換又は無置換のアリール基であり、Ｘは、単結合、置換若しくは無置換のアルキレン基、置換若しくは無置換のシクロアルキレン基、置換若しくは無置換のオキシアルキレン基、オキシ基、チオ基又はビニレン基であり、Ｚ_１は、置換若しくは無置換のアルキレン基、置換若しくは無置換のオキシアルキレン基又は一般式
−ＣＯＯＲ_６−
（式中、Ｒ_６は、アルキレン基である。）
で示される官能基であり、ｍは、０〜３の整数であり、ｎは、０又は１である。）
で示される化合物を一種以上含有することが好ましい。これにより、感度、残留電位等の電気特性を良好に持続することができる。

(Wherein R ₁ represents a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxyl group, a cyano group, a nitro group, Group, general formula -COOR ₂
(Wherein R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
A functional group represented by the general formula -COY
(In the formula, Y is a halogen group.)
Or a functional group represented by the general formula —CONR ₃ R ₄
(Wherein R ₃ and R ₄ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted arylene group, Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted aryl group, X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted oxyalkylene group, an oxy group, a thio group, or a vinylene group, and Z ₁ is a substituted or unsubstituted group. A substituted alkylene group, a substituted or unsubstituted oxyalkylene group, or a general formula —COOR ₆ —
(In the formula, R ₆ is an alkylene group.)
, M is an integer of 0 to 3, and n is 0 or 1. )
It is preferable to contain one or more compounds represented by: Thereby, electrical characteristics such as sensitivity and residual potential can be favorably sustained.

  Specific examples of the substituent in the compound represented by the general formula (1) are shown below.

In R ₁ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, and a naphthylmethyl group. Examples of the alkoxyl group include a methoxy group, an ethoxy group, and a propoxy group. These are halogen groups, nitro groups, cyano groups, alkyl groups such as methyl groups, ethyl groups, alkoxy groups such as methoxy groups and ethoxy groups, aryloxy groups such as phenoxy groups, aryl groups such as phenyl groups and naphthyl groups, It may be substituted with an aralkyl group such as a benzyl group or a phenethyl group. Of these, a hydrogen atom or a methyl group is preferable.

Examples of the aryl group of Ar ₃ and Ar ₄ include a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group.

  The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring. For example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group, s -Indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aseantrilenyl group, triphenylyl group, pyrenyl group, chrysenyl group Group, naphthacenyl group and the like.

  Non-condensed cyclic hydrocarbon groups include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether, diphenyl sulfone, biphenyl alkane, polyphenyl alkane, diphenyl alkane, diphenyl alkene, diphenyl alkyne. , Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane and polyphenylalkene, and ring assembly carbonization such as 9,9-diphenylfluorene The monovalent group of a hydrogen compound is mentioned.

  Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

Further, the aryl group of Ar ₃ and Ar ₄ may have a substituent as shown below.
(1) Halogen group, cyano group, nitro group and the like.
(2) Alkyl group C ₁ -C ₁₂ , preferably C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkyl group, and further a fluoro group, hydroxyl group, cyano group , _C 1 -C ₄ alkoxyl group, which may have a phenyl group or a halogen _group, C 1 -C ₄ alkyl or _C 1 -C ₄ phenyl group substituted with an alkoxy group. Specifically, methyl group, ethyl group, n-butyl group, isopropyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl group 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group.
(3) Alkoxyl group (-OR)
(In the formula, R is an alkyl group defined in (2).)
Specifically, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, t-butoxy group, n-butoxy group, s-butoxy group, isobutoxy group, 2-hydroxyethoxy group, benzyloxy group, trifluoro A methoxy group etc. are mentioned.
(4) The aryloxy group an aryl group, a phenyl group, a naphthyl _group, an alkoxyl group of C 1 -C _4, which may have an alkyl group or a halogen group C 1 -C _4. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(6) Amino group (—NR ₁ R ₂ )
(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group or an aryl group defined in (2). Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. , C ₁ -C ₄ alkoxy group, C ₁ -C ₄ alkyl group or halogen group, and R ₁ and R ₂ may form a ring together.)
Specific examples include amino group, diethylamino group, N-methyl-N-phenylamino group, diphenylamino group, ditolylamino group, dibenzylamino group, piperidino group, morpholino group, and pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group.

Specific examples include a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

Examples of the arylene group of Ar ₁ and Ar ₂ include a divalent group derived from the aryl group of Ar ₃ and Ar ₄ .

The alkylene group of X is a C _{1 to} C ₁₂ , preferably C _{1 to} C ₈ , more preferably a C _{1 to} C ₄ linear or branched alkylene group, and further includes a fluoro group, a hydroxyl group, and a cyano group. _group, C 1 -C ₄ alkoxy group, which may have a phenyl group or a halogen _group, C 1 -C ₄ alkyl or _C 1 -C ₄ phenyl group substituted with an alkoxy group. Specifically, methylene group, ethylene group, n-butylene group, isopropylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene. Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group.

Cycloalkylene group X represents a cyclic alkylene _group of C 5 -C _7, a fluoro group, a hydroxyl _group, which may have an alkyl group or an alkoxy group of _C 1 -C ₄ a C 1 -C _4. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.

  Examples of the oxyalkylene group for X are derived from an oxyalkylene group such as a tyleneoxy group and a propyleneoxy group, an alkylenedioxy group derived from ethylene glycol, propylene glycol, and the like, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the like. Bis (oxyalkylene) oxy group or poly (oxyalkylene) oxy group. The alkylene group of the oxyalkylene group may have a hydroxyl group, a methyl group, an ethyl group, or the like.

  As the vinylene group of X, the general formula

（式中、Ｒは、水素原子、アルキル基（（２）で定義されるアルキル基と同じ）又はアリール基（Ａｒ_３及びＡｒ_４のアリール基と同じ）であり、ａは、１又は２であり、ｂは、１〜３の整数である。）
で示される官能基が挙げられる。

Wherein R is a hydrogen atom, an alkyl group (same as the alkyl group defined in (2)) or an aryl group (same as the aryl group of Ar ₃ and Ar ₄ ), and a is 1 or 2 And b is an integer of 1 to 3.)
The functional group shown by these is mentioned.

Examples of the alkylene group and oxyalkylene group for Z ₁ include the same as those described above for X. In addition, the general formula of —Z ₁ —COOR ₆ —
(In the formula, R ₆ is an alkylene group.)
Examples of the functional group represented by are caprolactone-modified groups.

  In the present invention, the monofunctional radically polymerizable compound having a charge transporting structure is represented by the general formula (2).

（式中、Ｒ_７は、水素原子又はメチル基であり、Ｒ_８及びＲ_９は、それぞれ独立に、炭素数が１〜６のアルキル基であり、ｓ及びｔは、それぞれ独立に、０〜３の整数であり、Ｚ_２は、単結合、メチレン基、エチレン基又は構造式

(Wherein R ₇ is a hydrogen atom or a methyl group, R ₈ and R ₉ are each independently an alkyl group having 1 to 6 carbon atoms, and s and t are each independently 0 to Is an integer of 3, Z ₂ is a single bond, a methylene group, an ethylene group or a structural formula

で示される官能基であり、Ｐｈは、フェニレン基であり、ｏ、ｐ及びｑは、それぞれ独立に、０又は１である。）
で示される化合物を一種以上含有することがさらに好ましい。なお、ｓ又はｔが２又は３である場合は、複数のＲ_８又はＲ_９は、同一であっても異なってもよい。このとき、Ｒ_８及びＲ_９は、それぞれ独立に、メチル基又はエチル基であることが好ましい。

, Ph is a phenylene group, and o, p, and q are each independently 0 or 1. )
It is more preferable to contain one or more compounds represented by the formula: When s or t is 2 or 3, the plurality of R ₈ or R ₉ may be the same or different. At this time, R ₈ and R ₉ are preferably each independently a methyl group or an ethyl group.

  In the present invention, the compound represented by the general formula (1), particularly (2), is copolymerized with a trifunctional or higher functional radical polymerizable compound having no charge transporting structure in the main chain of the cured resin. In addition, it is incorporated into a cross-linked chain between the main chain and the main chain. In addition, in cross-linking, an intermolecular cross-link formed between one polymer and another polymer, and a site with a main chain folded in one polymer and another site are cross-linked. And intramolecular crosslinking. At this time, even when a radically polymerizable compound having three or more functional groups having no charge transporting structure is present in the main chain or in the crosslinked chain, it hangs from the chain portion. The triarylamine structure is bulky. However, since the triarylamine structure is not directly bonded to the chain portion and is suspended from the chain portion via a carbonyl group or the like, it is fixed in a state where the steric positioning is flexible, It is possible to have a spatial arrangement that is reasonably adjacent to each other in the cured resin. For this reason, it is presumed that there is little structural distortion in the molecule, and the protective layer B can adopt an intramolecular structure that is relatively free from interruption of the charge transport path.

  Specific examples of the monofunctional radically polymerizable compound having a charge transporting structure used in the present invention are shown below, but are not limited to these compounds.

電荷輸送性構造を有する１官能のラジカル重合性化合物の添加量は、保護層Ｂの総重量に対して、２０〜８０％であることが好ましく、３０〜７０％がさらに好ましい。この添加量が２０％未満であると、保護層Ｂの電荷輸送性が不十分となり、感度の低下、残留電位の上昇等の電気特性が低下することがあり、８０％を超えると、電荷輸送性構造を有さない３官能以上のラジカル重合性化合物の含有量と共に、架橋密度が低下して、耐摩耗性が不十分となることがある。

The addition amount of the monofunctional radically polymerizable compound having a charge transporting structure is preferably 20 to 80%, more preferably 30 to 70%, based on the total weight of the protective layer B. If this addition amount is less than 20%, the charge transporting property of the protective layer B becomes insufficient, and electrical characteristics such as a decrease in sensitivity and an increase in residual potential may be deteriorated. Along with the content of a trifunctional or higher-functional radically polymerizable compound that does not have an adhesive structure, the crosslinking density may decrease, and the wear resistance may be insufficient.

  Moreover, when forming the protective layer B, in order to advance a hardening reaction efficiently, you may add a polymerization initiator as needed. As the polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator can be used.

  Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5- Peroxide initiators such as bis (peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, azobisisobutylnitrile, azobiscyclohexane Examples include azo initiators such as carbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, and 4,4′-azobis-4-cyanovaleric acid.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl (2-hydroxy -2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl- Acetophenone-based or ketal-based photopolymerization initiators such as 2-morpholino (4-methylthiophenyl) propan-1-one and 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, benzoin, benzoin Methyl ether, benzoin ethyl ether, benzoin isobutyl ether, Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, 1 Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthone photopolymerization such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Initiators are mentioned. Examples of other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl). Phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compound, triazine compound, imidazole compound It is done. A compound having an effect of promoting the photopolymerization reaction can be used alone or in combination with a photopolymerization initiator. Examples of such compounds include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone. 2 or more may be used in combination.

  The addition amount of the polymerization initiator is preferably 0.5 to 40% by weight, more preferably 1 to 20% by weight, based on the radical polymerizable compound.

  The protective layer B is a solution containing a trifunctional or higher functional radical polymerizable compound not having a charge transporting structure, a monofunctional radical polymerizable compound not having a charge transporting structure, and, if necessary, a polymerization initiator. Alternatively, it is formed by applying a dispersion liquid onto the charge transport layer 503 or the photosensitive layer 504, and then curing by applying external energy.

Examples of a method for applying external energy include heating and light irradiation. Examples of the heating method include a method using air, a gas such as nitrogen, steam, various heat media, infrared rays, and electromagnetic waves. At this time, heating may be performed from either the coated surface side or the conductive support 500 side. The heating temperature is preferably 100 to 170 ° C. When the heating temperature is less than 100 ° C., the curing reaction may not proceed sufficiently. When the heating temperature exceeds 170 ° C., the curing reaction proceeds non-uniformly, causing large distortion and a large number of unreacted residues in the protective layer B. In some cases, a reaction termination end may be formed. In order to make the curing reaction proceed uniformly, it is preferable to heat at a temperature of less than 100 ° C. and then heat to 100 ° C. or higher. For light irradiation, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in the ultraviolet region can be used, but depending on the absorption wavelength of the radical polymerizable compound or photopolymerization initiator, A light source may be used. The amount of irradiation light is preferably 50 to 1000 mW / cm ² . When the irradiation light quantity is less than 50 mW / cm ² , it may take time for the curing reaction, and when it exceeds 1000 mW / cm ² , the curing reaction proceeds non-uniformly and local flaws occur on the surface of the protective layer B. May occur, and a large number of unreacted residues and reaction termination ends may be generated. In addition, internal stress may increase due to rapid cross-linking, which may cause cracks and film peeling. Examples of external energy other than these include radiation such as electron beams. Note that heat or light is preferable as the external energy from the viewpoint of easy control of the speed of the curing reaction and simplicity of the apparatus.

  The protective layer B preferably has a thickness of 1 to 10 μm, more preferably 2 to 8 μm. If the film thickness is less than 1 μm, the durability may fluctuate due to uneven film thickness. If the film thickness exceeds 10 μm, the total film thickness of the charge transport layer and the protective layer B increases, so that the reproduction of the image from the diffusion of charges. May decrease.

  As a method for dissolving or dispersing a trifunctional or higher functional radical polymerizable compound not having a charge transporting structure, a monofunctional radical polymerizable compound not having a charge transporting structure, and a polymerization initiator in a solvent, a charge generation layer may be used. A method similar to 502 can be used. Further, as a method for applying the protective layer B, a method similar to that for the charge generation layer 502 can be used.

  Examples of the solvent include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. Examples include ethers, halides such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolvs such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. Good.

  Examples of the conductive support 500 include a metal such as aluminum and stainless steel; a plastic having a coating layer of an aluminum alloy or an indium oxide-tin oxide alloy; paper or plastic impregnated with conductive particles; a conductive polymer Examples include plastic. Examples of the shape of the conductive support 500 include a cylindrical cylinder and a film.

  Conductive support for the purpose of improving adhesion of charge generation layer 502 or photosensitive layer 504, improving coating properties, protecting against electrical breakdown and protecting conductive support 500, covering defects, and improving charge injection properties It is preferable to provide the undercoat layer 501 on the body 500.

  The undercoat layer 501 is formed by applying a resin or, if necessary, a solution or dispersion containing fine metal powder onto the conductive support 500 and drying. The undercoat layer 501 preferably has a thickness of 0.1 to 10 μm, and more preferably 0.1 to 5 μm.

  As the resin, it is preferable to use a resin having high resistance to dissolution in a general organic solvent. 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. Curable resins such as these may be used, and two or more kinds thereof may be used in combination.

  Examples of the metal fine powder include metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide, metal sulfides, metal nitrides, and the like.

  As a method for dissolving or dispersing the resin and the metal fine powder in the solvent, a method similar to that for the charge generation layer 502 can be used. In addition, as a method for applying the undercoat layer 501, a method similar to that for the charge generation layer 502 can be used.

  Furthermore, as the undercoat layer 501, a metal oxide layer formed by a sol-gel method or the like using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can also be used. In addition, those prepared by anodizing alumina, organic materials such as polyparaxylylene (parylene), and inorganic materials such as silicon oxide, tin oxide, titanium oxide, ITO, and ceria by vacuum thin film fabrication methods are subtracted. The layer 501 can be used.

[Preparation of undercoat layer coating solution]
3 parts by mass of beccosol 1307-60-EL (produced by Dainippon Ink and Chemicals) of alkyd resin, 2 parts by mass of superbecamine G-821-60 (produced by Dainippon Ink and Chemicals) of melamine resin, titanium oxide type 20 parts by mass of CR-EL (manufactured by Ishihara Sangyo Co., Ltd.) and 100 parts by mass of 2-butanone were dispersed and mixed to prepare an undercoat layer coating solution.

[Preparation of charge generation layer coating solution 1]
In a ball mill disperser, pre-mixed polyvinyl butyral resin XYHL (UCC) 0.25 parts by mass, cyclohexanone 200 parts by mass and 2-butanone 80 parts by mass, structural formula

で示される電荷発生物質２．５質量部と、直径１０ｍｍのＰＳＺボールを投入し、８５ｒｐｍで７日間分散させ、電荷発生層塗布液１を調製した。

And a PSZ ball having a diameter of 10 mm were charged and dispersed at 85 rpm for 7 days to prepare a charge generation layer coating solution 1.

[Preparation of charge generation layer coating solution 2]
9 parts by weight of titanyl phthalocyanine having the X-ray diffraction spectrum shown in FIG. 9, 5 parts by weight of polyvinyl butyral resin XYHL (manufactured by UCC) and 400 parts by weight of 2-butanone are uniformly dispersed to prepare a charge generation layer coating solution 2 did.

[Preparation of charge transport layer coating solution]
Structural formula

で示されるトリフェニルアミン系化合物（Ａ）７質量部、粘度平均分子量が５００００のポリカーボネート樹脂（ビスフェノールＺ型）パンライトＴＳ−２０５０（帝人化成社製）１０質量部、反応性シリコーンオイルの１質量％のテトラヒドロフラン溶液ＫＦ５０−１００ＣＳ（信越化学工業社製）０．２質量部及びテトラヒドロフラン８０質量部を分散混合し、電荷輸送層塗布液を調製した。

7 parts by weight of a triphenylamine compound (A), 10 parts by weight of polycarbonate resin (bisphenol Z type) Panlite TS-2050 (manufactured by Teijin Chemicals Ltd.) having a viscosity average molecular weight of 50000, and 1 part by weight of reactive silicone oil % Of tetrahydrofuran solution KF50-100CS (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 parts by mass and 80 parts by mass of tetrahydrofuran were dispersed and mixed to prepare a charge transport layer coating solution.

[Preparation of protective layer coating solution 1]
3 parts by mass of a triphenylamine compound (A), 4 parts by mass of a polycarbonate resin (bisphenol Z type) Panlite TS-2050 (manufactured by Teijin Chemicals Ltd.), an average primary particle size of 0.3 μm, a refractive index of 1.7, 0.7 parts by mass of aluminum oxide Sumicorundum AA-03 (manufactured by Sumitomo Chemical Co., Ltd.) having a specific resistance of 10 ¹⁰ Ω · cm or more, 280 parts by mass of tetrahydrofuran and 80 parts by mass of cyclohexanone are dispersed and mixed, and a protective layer coating solution 1 Was prepared.

[Preparation of protective layer coating solution 2]
KAYARAD TMPTA (manufactured by Nippon Kayaku Co., Ltd.), 5 parts by weight of trimethylolpropane triacrylate having a molecular weight of 296 and a molecular weight / functional number of 99, KAYARAD of caprolactone-modified dipentaerythritol hexaacrylate having a molecular weight of 1947 and a molecular weight / functional group of 325 5 parts by mass of DPCA-120 (Nippon Kayaku Co., Ltd.), 10 parts by mass of a monofunctional radical polymerizable compound (No. 54) having a charge transporting structure, IRGACURE 184 of 1-hydroxycyclohexyl phenyl ketone (Ciba Specialty) A protective layer coating solution 2 was prepared by dispersing and mixing 1 part by mass of Chemicals Co., Ltd., 0.02 part by weight of BYK-UV3570 (BIC Chemie Japan) of a reactive silicone compound and 120 parts by mass of tetrahydrofuran.

[Preparation of Photoreceptor 1]
An undercoating layer coating solution, a charge generation layer coating solution 1, a charge transport layer coating solution, and a protective layer coating solution 1 were sequentially laminated by spray coating on an aluminum cylinder having a diameter of 30 mm and a length of 340 mm to produce a photoreceptor 1. . The thickness of the undercoat layer, charge generation layer, charge transport layer, and protective layer was 3.5 μm, 0.2 μm, 22 μm, and 5 μm, respectively. The spray coating conditions were as follows: the spray gun opening was 3/8, the coating liquid discharge pressure was 2.0 kgf / cm ² , the coating speed was 120 rpm, the coating speed was 7.14 mm / sec, and the spray gun The distance between the head and the object to be coated was 50 mm, and the number of coatings was two.

[Preparation of Photoreceptor 2]
A photoconductor 2 was produced in the same manner as the photoconductor 1 except that the charge generation layer coating solution 2 was used instead of the charge generation layer coating solution 1.

[Preparation of Photoreceptor 3]
A photosensitive member 3 is produced in the same manner as the photosensitive member 2 except that the protective layer coating solution 2 is used in place of the protective layer coating solution 1 and the coating and curing conditions of the protective layer coating solution 2 are changed as follows. did. The spray coating conditions were: the spray gun opening was 3.7 / 8, the coating liquid discharge pressure was 3.0 kgf / cm ² , the coating speed was 168 rpm, the coating speed was 10.7 mm / sec, The distance between the spray gun head and the object to be coated was 50 mm, and the number of coatings was one. The curing conditions were as follows: the light source was a metal halide lamp, the power of the light source was 160 W / cm 100%, the distance between the light source and the object to be coated was 110 mm, the number of revolutions of the object to be coated was 25 rpm, the irradiation time was 240 seconds, The temperature was 30 ° C.

[Preparation of Photoreceptor 4]
A photoconductor 4 was produced in the same manner as the photoconductor 3 except that the charge generation layer coating solution 1 was used instead of the charge generation layer coating solution 2.

[Preparation of Toner 1]
4.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.0 mol of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, A polyester resin having a softening point of 120 ° C. was obtained by reacting 4.5 mol of terephthalic acid, 0.5 mol of trimellitic anhydride and 4 g of dibutyltin oxide in a nitrogen atmosphere of 230 ° C. and 8.3 kPa for 8 hours.

  Next, 100 parts by mass of the above polyester resin, 5 parts by mass of MA100 (manufactured by Mitsubishi Chemical Corporation) of carbon black, 4 parts by mass of FCA-201-PS (manufactured by Fujikura Kasei Co., Ltd.) of styrene acrylic polymer, and Umex 110TS of wax ( 4 parts by mass) (manufactured by Sanyo Chemical Industries Co., Ltd.) were mixed in advance and melt kneaded using a twin screw extruder. The obtained melt-kneaded product was roughly crushed to obtain a toner crushed product. Further, the coarsely pulverized toner was finely pulverized with a collision-type airflow pulverizer and then subjected to air classification to obtain base particles having an average particle diameter of about 9 μm. Toner 100 was prepared by externally adding 1.05 parts by mass of RA200HS (manufactured by Nippon Aerosil Co., Ltd.) as silica fine particles to 100 parts by mass of the obtained base particles.

[Preparation of Developer 1]
Developer 1 was prepared by mixing 5 parts by mass of toner 1 with 100 parts by mass of a carrier obtained by coating a ferrite having a volume average particle size of 40 μm with a silicone resin.

[Production of Toner 2]
70.1 parts by mass of styrene, 19.9 parts by mass of n-butyl acrylate and 10.9 parts by mass of methacrylic acid were uniformly dissolved to prepare a monomer solution 1. Next, in a 5 L separable flask equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a cooling tube, 3010 g of ion-exchanged water and 7.08 g of non-ionic surfactant NAROACTY N200 (manufactured by Sanyo Chemical Industries) And heated to 80 ° C. with stirring under a nitrogen stream. Further, a solution in which 9.2 g of potassium persulfate was dissolved in 200 g of ion-exchanged water was added and heated to 75 ° C., and then the monomer solution 1 was added dropwise over 1 hour. After completion of the dropping, the mixture was heated and stirred at 75 ° C. for 2 hours to carry out polymerization (first stage polymerization) to prepare a resin particle dispersion 1.

  In a flask equipped with a stirrer, 122.9 parts by mass of styrene, 49.7 parts by mass of n-butyl acrylate, 16.3 parts by mass of methacrylic acid, and structural formula

で示される離型剤（Ａ）９６．０質量部を投入し、８０℃に加温して、均一に溶解させ、モノマー溶液２を調製した。次に、攪拌装置、温度センサー、冷却管を備えた５Ｌ用のセパラブルフラスコに、イオン交換水１３４０ｇ及び非イオン界面活性剤のナロアクティーＮ２００（三洋化成工業社製）５．７ｇを溶解させた。さらに、８０℃に加温した後、循環経路を有する機械式分散機クレアミックス（ＣＬＥＡＲＭＩＸ）（エム・テクニック社製｝を用いて、モノマー溶液２と２時間分散混合し、分散粒径が６４６ｎｍの乳化粒子（油滴）を有する乳化液を調製した。次に、イオン交換水１４６０ｍＬと、イオン交換水２５４ｍＬに過硫酸カリウム６．５１ｇを溶解させた溶液と、３−メルカプトプロピオン酸ｎ−オクチル０．７５ｇと、樹脂粒子分散液１を加え、８０℃で３時間加熱、攪拌することにより、重合（第２段重合）を行い、樹脂粒子分散液２を調製した。

A monomer solution 2 was prepared by charging 96.0 parts by mass of the release agent (A) represented by the formula (1), heating to 80 ° C., and uniformly dissolving the mixture. Next, in a 5 L separable flask equipped with a stirrer, a temperature sensor, and a cooling tube, 1340 g of ion-exchanged water and 5.7 g of non-ionic surfactant NAROACTY N200 (manufactured by Sanyo Chemical Industries) were dissolved. . Further, after heating to 80 ° C., using a mechanical disperser CLEARMIX having a circulation path (manufactured by M Technique Co., Ltd.), the mixture is dispersed and mixed with the monomer solution 2 for 2 hours, and the dispersed particle size is 646 nm. An emulsion having emulsified particles (oil droplets) was prepared, and then 1460 mL of ion-exchanged water, a solution of 6.51 g of potassium persulfate dissolved in 254 mL of ion-exchanged water, and n-octyl 3-mercaptopropionate 0 .75 g and the resin particle dispersion 1 were added, and the mixture was heated and stirred at 80 ° C. for 3 hours to carry out polymerization (second stage polymerization) to prepare a resin particle dispersion 2.

  A solution prepared by dissolving 8.87 g of a polymerization initiator VA-057 (manufactured by Wako Pure Chemical Industries, Ltd.) in 346 mL of ion-exchanged water is added to the resin particle dispersion 2, and further 322.3 parts by mass of styrene, acrylic acid n-butyl 121.9 parts by mass, methacrylic acid 35.5 parts by mass, structural formula

で示されるアミノアクリル（メタ）アクリルアミド系化合物４．５質量部及びｎ−オクチルメルカプタン６．４質量部の混合物を９５℃で１時間かけて滴下した。滴下終了後、２時間加熱、攪拌することにより、重合（第３段重合）を行った後、２８℃に冷却し、外層用樹脂粒子分散液を調製した。

A mixture of 4.5 parts by mass of an aminoacrylic (meth) acrylamide compound represented by the formula and 6.4 parts by mass of n-octyl mercaptan was added dropwise at 95 ° C. over 1 hour. After completion of dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to prepare a resin particle dispersion for outer layer.

  A flask equipped with a stirrer was charged with 172.9 parts by mass of styrene, 55.0 parts by mass of n-butyl acrylate, 23.1 parts by mass of methacrylic acid, and 96.0 parts by mass of the release agent (A). The mixture was heated to 0 ° C. and dissolved uniformly to prepare a monomer solution 3. Next, in a separable flask for 5 L equipped with a stirrer, a temperature sensor, and a cooling tube, 1340 g of ion-exchanged water and a structural formula

で示されるアニオン性界面活性剤（Ａ）２．５ｇを溶解させた。さらに、８０℃に加温した後、機械式分散機クレアミックス（ＣＬＥＡＲＭＩＸ）（エム・テクニック社製）を用いて、モノマー溶液３と２時間分散混合し、分散粒径が４８２ｎｍの乳化粒子（油滴）を有する乳化液を調製した。次に、イオン交換水１４６０ｍＬを添加した後、イオン交換水１４２ｍＬに過硫酸カリウム７．５ｇを溶解させた溶液と、ｎ−オクタンチオール６．７４ｇを加え、８０℃で３時間加熱、攪拌することにより重合（第１段重合）を行い、樹脂粒子分散液３を調製した。

2.5 g of the anionic surfactant (A) represented by Further, after heating to 80 ° C., using a mechanical disperser CLEARMIX (manufactured by M Technique Co., Ltd.), the mixture is dispersed and mixed with the monomer solution 3 for 2 hours to obtain emulsified particles having a dispersed particle size of 482 nm (oil Emulsions having droplets) were prepared. Next, after adding 1460 mL of ion-exchanged water, add a solution prepared by dissolving 7.5 g of potassium persulfate in 142 mL of ion-exchanged water and 6.74 g of n-octanethiol, and heat and stir at 80 ° C. for 3 hours. Polymerization (first stage polymerization) was performed to prepare resin particle dispersion 3.

  A solution obtained by dissolving 11.6 g of potassium persulfate in 220 mL of ion-exchanged water is added to the resin particle dispersion 3, and 291.2 parts by mass of styrene, 132.2 parts by mass of n-butyl acrylate, 42 of methacrylic acid are added. A mixture of .9 parts by mass and 7.51 parts by mass of n-octanethiol was added dropwise at 80 ° C. over 1 hour. After completion of dropping, the mixture was heated and stirred for 2 hours to perform polymerization (second stage polymerization), and then cooled to 28 ° C. to prepare a resin particle dispersion 4.

  After dissolving 59.0 g of the anionic surfactant (A) in 1600 mL of ion-exchanged water, 280.0 g of yellow pigment C.I. I. Pigment Yellow 74 was gradually added, and further dispersed using a mechanical disperser CLEARMIX (manufactured by M Technique Co., Ltd.) to prepare a colorant dispersion.

  In a four-necked flask equipped with a stirrer, a nitrogen introducing tube, a temperature sensor, and a cooling tube, 259.3 g (solid content conversion) of resin particle dispersion 4, ion-exchanged water 1120 g, and colorant dispersion 237 g Charged and stirred. Further, after heating to 30 ° C., a 5M aqueous sodium hydroxide solution was added to adjust the pH to 10. Next, a solution prepared by dissolving 55.3 g of magnesium chloride hexahydrate in 55.3 mL of ion-exchanged water was added over 10 minutes while stirring at 30 ° C. After standing for 3 minutes, the resin particles and the colorant were finally salted out and fused at 90 ° C. while gradually raising the temperature over 60 minutes. While continuing the heating and stirring, the particle size was measured using a Coulter Counter TA-II (manufactured by Beckman Coulter, Inc.). When the volume average particle size reached 5.5 μm, sodium chloride was added to 100 mL of ion-exchanged water. A solution in which 3 g was dissolved was added to stop the growth of particles, and a colored particle dispersion was prepared.

  5M sodium hydroxide aqueous solution was added to 87.5 g (converted to solid content) of the outer layer resin particle dispersion to adjust the pH to 8.

  On the other hand, the colored particle dispersion is heated and stirred for 1 hour or more to control the shape. When the average circularity reaches 0.944, the pH-adjusted outer layer resin particle dispersion is added, and the colored particles are dispersed. The outer layer resin particles were fused to the surface. Next, an aqueous solution in which 123.9 g of sodium chloride was dissolved in 500 g of ion-exchanged water was added and stirred at 95 ° C. for 2 hours. Further, while gradually cooling at 8 ° C./min, hydrochloric acid was finally added to adjust to pH 2 at 30 ° C., stirring was stopped, and a base particle dispersion was prepared. The base particles had an average circularity of 0.964.

  After subjecting the base particle dispersion to a centrifugal dehydrator, it is washed with 20 times the mass of ion-exchanged water with respect to the solid content, and further dried with a vacuum dryer until the water content becomes 4% by mass, Base particles were obtained.

  0.8 parts by mass of hydrophobic silica R805 (manufactured by Nippon Aerosil Co., Ltd.) is added to the base particles, and the peripheral speed of the rotary blade of the Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.) is set to 30 m / sec and mixed for 25 minutes did. Next, coarse particles were removed using a sieve having an opening of 45 μm, and toner 2 was produced.

[Preparation of Developer 2]
Developer 2 was prepared by mixing 6 parts by mass of toner 2 with 100 parts by mass of a carrier obtained by coating a ferrite having a volume average particle diameter of 40 μm with a silicone resin.

[Measurement of the transit time _{t T} of the photosensitive member]
An optical attenuation curve was obtained by multipoint measurement of the process time T _ed using the evaluation apparatus shown in FIG. Next, in the obtained light attenuation curve, an exposure amount was determined so that a sharp light attenuation of the surface potential of the photoreceptor does not occur. Furthermore, for this exposure, plots the potential of the exposed portion relative to the process time T _ed, the potential of the exposed portion in a short time side of the process time T _ed is calculated the rise start time (transit time t _T). Table 1 shows the transit times t _T of the photoreceptors 1 to 4.

なお、測定条件は、感光体の表面における線速度を２７０ｍｍ／秒、露光光の波長を６５５ｎｍ、副走査方向の解像度を１２００ｄｐｉ、除電電圧を８Ｖ、感光体の帯電電位を−８００Ｖとした。また、プロセス時間Ｔ_ｅｄの調節は、感光体の中心軸から見たときの現像位置に相当する表面電位プローブと露光位置がなす角度θ［°］を変化させることで調整した。このとき、プロセス時間Ｔ_ｅｄ［秒］は、感光体の円周長をＬ［ｍｍ］、感光体の表面における線速度をｖ［ｍｍ／秒］とすると、式
Ｔ_ｅｄ＝Ｌ×（θ／３６０）／ｖ
［実施例１］
図３に示す画像形成装置として、１２００ｄｐｉレーザービームプリンタを用意し、プロセス時間Ｔ_ｅｄを６５ミリ秒に改造した。このとき、露光装置は、発光点が３×３の二次元に配置され、レーザビーム数が９本の面発光レーザアレイを備え、その走査線数を１２００ｄｐｉとした。また、帯電方式を、ゴムローラを当接する接触帯電とした。なお、本実施例では、現像剤１及び感光体１を用いた。

Measurement conditions were such that the linear velocity on the surface of the photoconductor was 270 mm / second, the wavelength of exposure light was 655 nm, the resolution in the sub-scanning direction was 1200 dpi, the charge removal voltage was 8 V, and the charge potential of the photoconductor was -800 V. The process time T _ed was adjusted by changing the angle θ [°] formed by the surface potential probe and the exposure position corresponding to the development position when viewed from the central axis of the photoreceptor. At this time, the process time T _ed [seconds] is expressed by the following formula: T _ed = L × (θ /) where the circumferential length of the photosensitive member is L [mm] and the linear velocity on the surface of the photosensitive member is v [mm / second]. 360) / v
[Example 1]
As an image forming apparatus shown in FIG. 3, a 1200 dpi laser beam printer was prepared, and the process time T _ed was modified to 65 milliseconds. At this time, the exposure apparatus was provided with a surface emitting laser array in which the light emitting points were arranged in a two-dimensional manner of 3 × 3, the number of laser beams was nine, and the number of scanning lines was 1200 dpi. The charging method was contact charging in contact with the rubber roller. In this embodiment, the developer 1 and the photoreceptor 1 are used.

  Process conditions were set so as to suit such an image forming apparatus. The charging potential of the photosensitive member was set to -800 V in the dark part potential.

  Next, an endurance test was conducted by printing out 10 k (= 10000) sheets of a text document having a printing area ratio of 6% continuously with A4 horizontal feed, and the following evaluations were performed.

(1) Image Density A square solid black image having a side of 5 mm was formed, and the image density was measured and evaluated using an image density measuring machine RD918 (manufactured by Macbeth). The image density is very good (1.3 or more) A, the image quality is 1.2 (less than 1.3), B is normal (1.1 or more and less than 1.2). The result was judged as C, and the bad (less than 1.1) as D.

(2) Resolution The resolution was evaluated by the reproducibility of 1200 dpi 21 μm small-diameter isolated dots that were easily closed and difficult to reproduce due to the electric field of the electrostatic latent image. In addition, the thing which is 5 or less defects in 100 is A, the thing which is 6-10 is B, the thing which is 11-20 is C, and the thing which is 21 or more is determined as D.

(3) Transferability The toner remaining on the photoreceptor when a solid black image is formed is removed by taping with a Mylar tape, and only the Mylar tape is put on the paper from the image density of the stripped Mylar tape on the paper. The transferability was evaluated from the numerical value obtained by subtracting the image density of the pasted material. At this time, the image density was measured in the same manner as in (1). The transferability is very good (less than 0.05) A, good (0.05 or more and less than 0.07) is B, and normal (0.07 or more and less than 0.1). The result was judged as C and bad (0.1 or more) as D.

(4) Fogging The toner remaining on the photoreceptor when a solid white image is formed is removed by taping with Mylar tape, and only the Mylar tape is pasted on the paper based on the image density of the stripped Mylar tape on the paper. The fog was evaluated from the numerical value obtained by subtracting the image density of the sample. At this time, the image density was measured in the same manner as in (1). The fog is very good (less than 0.05), A is good (0.05 or more and less than 0.07), and B is normal (0.07 or more and less than 0.1). Was determined as C, and bad (0.1 or more) as D.

(5) Image stain The image after fixing was visually observed to evaluate image stain. Note that the case where no image smear occurred was determined as A, the case where faint occurrence occurred, B, the case where a certain degree of occurrence occurred, and the case where remarkably occurred as D.
In addition, the transferability, fog, resolution, and charging roller contamination were evaluated.

(6) Charging roller contamination The toner weight (mg / cm ² ) per unit area on the charging roller was measured to evaluate the charging roller contamination. In addition, charging roller contamination is not generated (less than 0.1 mg / cm ² ) A, faint (0.1 mg / cm ² or more and less than 0.3 mg / cm ² ) is B, to some extent It was determined that C was generated (0.3 mg / cm ² or more and less than 0.5 mg / cm ² ), and D was remarkably generated (0.5 mg / cm ² or more) as D.

(7) Matching with developing roller After the endurance test was completed, the state of occurrence of sticking of the toner remaining on the surface of the developing roller and the effect on the printed image were visually observed to evaluate the matching with the developing roller. . Note that the matching with the developing roller is very good (toner sticking does not occur) A, the good (toner sticking hardly occurs) B, normal (there is toner sticking, It was judged as C, which has little influence on the image, and D, which is bad (many toner adheres and causes image unevenness).

(8) Matching with the photoconductor After the endurance test was completed, the occurrence of scratches on the surface of the photoconductor and the occurrence of toner sticking and the effect on the printed image were visually observed to evaluate the matching with the photoconductor. . In addition, A with a very good matching with the photoconductor (no scratches on the surface of the photoconductor and no toner sticking), and good (slight scratches on the surface of the photoconductor can be seen) B is normal (there is toner adhesion and scratches on the surface of the photoreceptor, but the influence on the image is small), and C is bad (more toner adhesion, and the vertical It was determined as D that caused streak-like image defects).

(9) Matching with fixing device After the endurance test was completed, the occurrence of scratches on the surface of the fixing roller and the occurrence of toner sticking and the effect on the printed image were visually observed to evaluate the matching with the fixing device. . Note that the matching with the fixing device is very good (no flaws on the surface of the fixing roller or toner sticking occurs) A, and good (a slight toner sticking is seen, but there is no influence on the image) ) Is normal, B is normal (there is toner sticking or flaws on the surface of the fixing roller, but has little effect on the image), C is bad, and the toner is sticking much (resulting in image defects) Was determined as D.

[Examples 2 and 3]
Evaluation was performed in the same manner as in Example 1 except that the process time T _ed was modified to 70 milliseconds and 80 milliseconds, respectively.

[Comparative Examples 1-4]
Evaluation was performed in the same manner as in Example 1 except that the process time T _ed was modified to 50 milliseconds, 60 milliseconds, 90 milliseconds, and 110 milliseconds, respectively.

[Examples 4 to 6]
The photosensitive member 2 is used instead of the photosensitive member 1, the developer 2 is used instead of the developer 1, the image forming apparatus shown in FIG. 4 is used instead of the image forming apparatus shown in FIG. Evaluation was performed in the same manner as in Example 1 except that _ed was modified to 65 milliseconds, 75 milliseconds, and 80 milliseconds, respectively.

[Comparative Examples 5 to 8]
Evaluation was performed in the same manner as in Example 4 except that the process time T _ed was modified to 55 milliseconds, 60 milliseconds, 90 milliseconds, and 100 milliseconds, respectively.

[Examples 7 to 9]
The photosensitive member 3 is used instead of the photosensitive member 2, the image forming apparatus shown in FIG. 5 is used instead of the image forming apparatus shown in FIG. 4, and the process times T _ed are 65 milliseconds, 70 milliseconds, and 80 milliseconds, respectively. Evaluation was performed in the same manner as in Example 4 except that the modification was made to milliseconds.

[Comparative Examples 9-12]
Evaluation was performed in the same manner as in Example 7 except that the process time T _ed was modified to 50 milliseconds, 60 milliseconds, 90 milliseconds, and 110 milliseconds.

[Examples 10 to 12]
The photosensitive member 4 is used instead of the photosensitive member 1, the image forming apparatus shown in FIG. 6 is used instead of the image forming apparatus shown in FIG. 3, and the process time T _ed is set to 65 milliseconds, 75 milliseconds, and 80 milliseconds. Evaluation was performed in the same manner as in Example 1 except that the model was modified in seconds.

[Comparative Examples 13 to 16]
Evaluation was performed in the same manner as in Example 10 except that the process time T _ed was modified to 55 milliseconds, 60 milliseconds, 90 milliseconds, and 100 milliseconds.

  The above evaluation results are shown in Table 2.

実施例１〜１２では、１．０≦ｔ_Ｔ／Ｔ_ｅｄ≦１．３を満たすことにより、トナーの残留が長期的に抑制され、高濃度でカブリのない高品質の画像が得られた。その結果、クリーナーレスプロセスが達成された。

In Examples 1 to 12, by satisfying 1.0 ≦ t _T / T _ed ≦ 1.3, residual toner was suppressed for a long period of time, and high-quality images with high density and no fogging were obtained. As a result, a cleaner-less process was achieved.

It is a figure which shows the change of the electric potential of the exposure part of a photoreceptor with respect to process time. It is a figure which shows an example of the time responsiveness evaluation apparatus of the optical attenuation of the surface potential of a photoreceptor. 1 is a cross-sectional view illustrating an example of an image forming apparatus of the present invention. It is sectional drawing which shows the other example of the image forming apparatus of this invention. It is sectional drawing which shows an example of the process cartridge of this invention. It is sectional drawing which shows the other example of the process cartridge of this invention. It is sectional drawing which shows an example of the photoreceptor used by this invention. It is sectional drawing which shows the other example of the photoreceptor used by this invention. It is a figure which shows the X-ray-diffraction spectrum of the titanyl phthalocyanine of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Exposure apparatus 3L (exposure) light 4 Developing apparatus 4a, 4b, 4c, 4d Developing unit 5 Intermediate transfer body 6, 7 Transfer apparatus 8 Fixing apparatus 9 Static eliminating apparatus 10, 11, 12 Roller 13 Electrometer P Transfer medium 100, 200 Image forming apparatus 300, 400 Process cartridge 301, 302, 401, 402 Opening 500 Conductive support 501 Undercoat layer 502 Charge generation layer 503 Charge transport layer 504 Photosensitive layer 505 Protective layer

Claims (20)

A regular development type image forming apparatus,
An image carrier, a charging unit for charging the image carrier, an electrostatic latent image forming unit for forming an electrostatic latent image on the charged image carrier, and development for developing the electrostatic latent image with toner A developing unit having a plurality of units;
In the image carrier, the ratio of the transit time of the image carrier to the time from the formation of the electrostatic latent image to the development of the region where the electrostatic latent image is formed is 1.0. An image forming apparatus characterized in that it is 1.3 or less.   The image forming apparatus according to claim 1, wherein the electrostatic latent image forming unit includes a scanning optical unit that scans a plurality of laser beams on the image carrier.   The image forming apparatus according to claim 2, wherein the scanning optical unit includes three or more surface emitting lasers.   The image forming apparatus according to claim 3, wherein the scanning optical unit includes a two-dimensional array including the three or more surface-emitting lasers. The image carrier has a general formula

Wherein R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a cyano group or a halogen group, and X and Y are each independently a general formula

(Wherein R ₃ is a hydrogen atom, an aryl group or an alkyl group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxyl group, A cyano group, a dialkylamino group, a nitro group, a halogen group, or a haloalkyl group, and Z is a substituted or unsubstituted carbocyclic aromatic group or a substituted or unsubstituted heterocyclic aromatic group.
It is a functional group shown by. )
The image forming apparatus according to claim 1, further comprising a photosensitive layer containing a compound represented by the formula:   The image forming apparatus according to claim 5, wherein the X and Y are different.   The image carrier has peaks at diffraction angles 2θ ± 0.2 ° of 9.4 °, 9.6 °, and 24.0 ° in an X-ray diffraction spectrum using a characteristic X-ray of CuKα. The intensity of the peak present at .2 ° is maximum, the peak at the minimum angle is present at 7.3 °, and the peak between the peak present at 7.3 ° and the peak present at 9.4 ° 5. The image forming apparatus according to claim 1, further comprising a photosensitive layer containing a crystal of titanyl phthalocyanine having no peak at 26.3 °.   The image forming apparatus according to claim 1, wherein the image carrier has a protective layer as an outermost layer. The image forming apparatus according to claim 8, wherein the protective layer contains a filler having a specific resistance of 10 ¹⁰ Ω · cm or more.   The protective layer is formed by curing at least a trifunctional or higher functional radical polymerizable compound having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure. The image forming apparatus according to claim 8 or 9. The monofunctional radically polymerizable compound having the charge transporting structure has the general formula

(Wherein R ₁ represents a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxyl group, a cyano group, a nitro group, Group, general formula -COOR ₂
(Wherein R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
A functional group represented by the general formula -COY
(In the formula, Y is a halogen group.)
Or a functional group represented by the general formula —CONR ₃ R ₄
(Wherein R ₃ and R ₄ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.)
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted arylene group, Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted aryl group, X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted oxyalkylene group, an oxy group, a thio group, or a vinylene group, and Z ₁ is a substituted or unsubstituted group. A substituted alkylene group, a substituted or unsubstituted oxyalkylene group, or a general formula —COOR ₆ —
(In the formula, R ₆ is an alkylene group.)
, M is an integer of 0 or more and 3 or less, and n is 0 or 1. )
The image forming apparatus according to claim 10, comprising at least one compound represented by the formula: The monofunctional radically polymerizable compound having the charge transporting structure has the general formula

(Wherein R ₇ is a hydrogen atom or a methyl group, R ₈ and R ₉ are each independently an alkyl group having 1 to 6 carbon atoms, and s and t are each independently 0 It is an integer of 3 or less and Z ₂ is a single bond, a methylene group, an ethylene group or a structural formula

, Ph is a phenylene group, and o, p, and q are each independently 0 or 1. )
The image forming apparatus according to claim 10, comprising at least one compound represented by the formula:   The image forming apparatus according to claim 10, wherein heating or light irradiation is performed when the curing is performed.   The image forming apparatus according to claim 1, further comprising a cleaning unit that cleans the image carrier. A process cartridge that is detachable from a main body of the image forming apparatus according to claim 1,
A process cartridge comprising at least the image carrier. A regular development type image forming method,
A charging step for charging the image carrier;
An electrostatic latent image forming step of forming an electrostatic latent image on the charged image carrier;
A plurality of development steps for developing the electrostatic latent image with toner;
In the image carrier, the ratio of the transit time of the image carrier to the time from the formation of the electrostatic latent image to the development of the region where the electrostatic latent image is formed is 1.0. An image forming method, wherein the image forming method is 1.3 or less.   The image forming method according to claim 16, wherein an electrostatic latent image is formed on the charged image carrier with a resolution of 1200 dpi or more.   18. The image forming method according to claim 16, wherein a plurality of laser light beams are scanned on the image carrier when forming the electrostatic latent image.   The image forming method according to claim 18, wherein a plurality of laser light beams are scanned on the image carrier using three or more surface-emitting laser arrays.   20. The image forming method according to claim 19, wherein a plurality of laser light beams are scanned on the image carrier using a two-dimensional array including three or more surface emitting laser arrays.

Images