JP4562163B2 - Method for producing electrophotographic photosensitive member and electrophotographic photosensitive member - Google Patents

Description

【０１４０】
【表２】

【０１４１】
【表３】

【０１４２】
【表４】

(実施例２)
図３に記載の堆積膜形成装置を用い、直径３０ｍｍ、長さ３５８ｍｍの円筒状アルミニウムシリンダー上に、表５に示した条件で負帯電用電子写真感光体を作製した。
【０１４３】
まず、カーボン原子とシリコン原子が含有する表面層をシリコンウエハー基板とコーニング社製7059ガラス基板上に堆積し、カーボン原子含有量(Ｃ/(Ｓi+Ｃ))と光学的バンドギャップの関係を調べた。本実施例では、シランガスとメタンガスの流量を変化させてカーボン原子含有量(Ｃ/(Ｓi+Ｃ))の増加に伴って光学的バンドギャップが増加する領域と減少する領域を調べた。そして、第一の表面層はカーボン原子含有量(Ｃ/(Ｓi+Ｃ))が増加するに伴って光学的バンドギャップが増加する領域で形成し、第二の表面層はカーボン原子含有量(Ｃ/(Ｓi+Ｃ))が増加するに伴って光学的バンドギャップが減少する領域で形成し、更には第一の表面層と第二の表面層の光学的バンドギャップの差が０.０５eＶになように組み合わせた。
【０１４４】
なお、実施例２においては、第一の表面層に含有させるシリコン原子に対する周期律表第１３族元素の含有量を50原子ppｍ、100原子ppｍ、5000原子ppｍ、10000原子ppｍ、30000原子ppｍ、35000原子ppｍとなるように変化させた。また、本実施例では周期律表第１３族元素を含有させるガス種としてジボランガスを使用した。
【０１４５】
作製した各々の電子写真感光体について実施例１と同様にして相対評価を行った結果を表６に示す。表６から明らかなようにシリコン原子に対する周期律表第１３族元素の含有量が、100原子ppｍ以上30000原子ppｍ以下の第一の表面層を形成した負帯電用電子写真感光体は、帯電能の向上および画像流れの抑制に関して特に効果が得られた。
【０１４６】
【表５】

【０１４７】
【表６】

(実施例３)
図３に記載の堆積膜形成装置を用い、直径３０ｍｍ、長さ３５８ｍｍの円筒状アルミニウムシリンダー上に、表７に示した条件で正帯電用電子写真感光体を作製した。
【０１４８】
まず、カーボン原子とシリコン原子が含有する表面層をシリコンウエハー基板とコーニング社製7059ガラス基板上に堆積し、シランガスとメタンガスの流量を変化させてカーボン原子含有量(Ｃ/(Ｓi+Ｃ))の増加に伴って光学的バンドギャップが増加する領域と減少する領域を調べた。そして、第一の表面層はカーボン原子含有量(Ｃ/(Ｓi+Ｃ))が増加するに伴って光学的バンドギャップが増加する領域で形成し、第二の表面層はカーボン原子含有量(Ｃ/(Ｓi+Ｃ))が増加するに伴って光学的バンドギャップが減少する領域で形成し、更には第一の表面層と第二の表面層の光学的バンドギャップの差が０.１eＶになように組み合わせた。
【０１４９】
なお、実施例３においては、第一の表面層に含有させるシリコン原子に対する周期律表第１５族元素の含有量を50原子ppｍ、100原子ppｍ、5000原子ppｍ、10000原子ppｍ、30000原子ppｍ、35000原子ppｍとなるように変化させた。また、本実施例では周期律表第１５族元素を含有させるガス種としてホスフィンガスを使用した。
【０１５０】
(比較例４)
実施例３と同様に、図３に記載の堆積膜形成装置を用いて表８に示した条件により、アルミニウムシリンダー上に下部電荷注入阻止層、光導電層を順次積層し、続いて表面層を、実施例のように二層に分けず、比較例３と同様に一層積層し正帯電用電子写真感光体を作製した。
【０１５１】
なお、比較例４では、高周波電極に導入する発振周波数は１０５ＭＨzのみで高周波電力導入を行った。
【０１５２】
このようにして作製した正帯電用電子写真感光体を、次の様に特性評価を行った。
【０１５３】
＜帯電能＞
電子写真感光体を電子写真装置(キヤノン製ＧＰ４０５を正帯電評価用に改造したもの)に設置し、プロセススピード２００ｍｍ/sec、前露光(波長６６０nｍのＬＥＤ)光量４lx・s、帯電器の電流値1000μＡの条件にて電子写真装置の現像器位置にセットした表面電位計(ＴＲＥＫ社のＭodel３４４)の電位センサーにより像露光(波長６５５nｍの半導体レーザー)を照射しない状態での感光体の表面電位を測定し、それを帯電能とした。
【０１５４】
＜強露光画像流れ＞
強露光画像流れの評価は、電子写真装置(キヤノン製ＧＰ４０５を正帯電評価用に改造したもの)で図５に示した黒色部と白色部が一定の幅aで並んだテストチャートを用意し、線幅aを狭めていった時に複写画像上において再現し、解像しうる最小の線幅aにより行った。即ち、線幅aを狭めていった時に、ある線幅a以下になると画像上の隣り合う黒色部の輪郭の画像流れによる微少なボケが重なり合い、事実上解像不可となってしまう。その時の線幅aを画像流れの程度を表す指標とした。
【０１５５】
それぞれの項目に関して、比較例４の正帯電用電子写真感光体の評価値を１００として相対比較を行った。
【０１５６】
実施例３、比較例４の結果を表９に示す。表９から明らかなようにシリコン原子に対する周期律表第１５族元素の含有量が、100原子ppｍ以上30000ppｍ以下の第一の表面層を形成した電子写真感光体は、帯電能の向上および画像流れの抑制に関して特に効果が得られた。
【０１５７】
【表７】

【０１５８】
【表８】

【０１５９】
【表９】

【０１６０】
【発明の効果】
本発明によれば、帯電能、感度の向上及び特性むらの低減を高次元で両立するとともに強露光画像流れ、融着および感光体表面に生じる微小なクラックを低減して画像品質を飛躍的に向上させた、シリコン原子を母体とした非単結晶材料で構成された電子写真感光体が得られる。
【図面の簡単な説明】
【図１】本発明の電子写真感光体の好適な層構成の一例を説明するための模式的構成図である。
【図２】本発明に表面層のおけるカーボン含有量と光学的バンドギャップの関係図である。
【図３】本発明に適用しうる堆積膜形成装置の模式図である。
【図４】本発明に適用しうる堆積膜形成装置の模式図である。
【図５】テストチャートの一例を説明するための概略図である。
【符号の説明】
100 電子写真感光体
101 導電性基体
102 光受容層
103 光導電層
104 第一の表面層
105 第二の表面層
106 下部電荷注入阻止層
3100 堆積装置
3110 中心部
3111，4111 反応容器
3112，4112 排気管
3113，4113 円筒状基体
3114，4114 高周波電極
3115，4115 マッチングボックス
3116，3117 高周波電源
3118，4118 原料ガス導入管
3119 シールド
3120，4120 発熱体
3121 回転軸
3122 減速ギア
3123 モータ
3124 電力分岐板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member sensitive to electromagnetic waves such as light (light in a broad sense, meaning infrared rays, visible rays, ultraviolet rays, X-rays, γ rays, etc.), and a method for producing the same. .
[0002]
[Prior art]
In the field of image formation, as a photoconductive material for forming a photoreceptive layer in an electrophotographic photosensitive member, it has a high sensitivity, a high SN ratio (photocurrent (Ip) / dark current (Id)), and spectral characteristics of electromagnetic waves to be irradiated Characteristics such as having an absorption spectrum adapted to the above, fast photoresponsiveness, having a desired dark resistance value, and being harmless to the human body during use are required. In particular, in the case of an electrophotographic photosensitive member incorporated in an electrophotographic apparatus used in an office as an office machine, the above-mentioned pollution-free property is an important point.
[0003]
An electrophotographic photosensitive member made of amorphous silicon (hereinafter abbreviated as a-Si) is attracting attention as a photoconductive material exhibiting excellent properties in this respect.
[0004]
In general, such an electrophotographic photosensitive member is obtained by heating a conductive substrate to 50 ° C. to 350 ° C., and vacuum deposition, sputtering, ion plating, thermal CVD, photo CVD on the substrate. Then, a photoconductive layer made of a-Si is formed by a film forming method such as a plasma CVD method. Among them, a plasma CVD method, that is, a method of decomposing a source gas by high frequency (RF wave, VHF wave) or microwave glow discharge to form an a-Si deposited film on a substrate is put to practical use. Yes.
[0005]
For example, JP-A-57-115556 discloses a photoconductive member having a photoconductive layer formed of an a-Si deposited film, such as electrical and optical characteristics such as dark resistance, photosensitivity, and photoresponsiveness. In order to improve the use environment characteristics such as photoconductive characteristics and moisture resistance, as well as the stability over time, the photoconductive layer made of an amorphous material containing silicon atoms as a base material contains non-silicon atoms and carbon atoms. A technique for providing a surface barrier layer made of a photoconductive amorphous material is described.
[0006]
Further, JP-A-62-028764 discloses a photoconductor comprising a charge blocking layer, a photoconductive layer, an intermediate layer, and a surface modified layer, in which carbon atoms, nitrogen atoms and oxygen atoms contained in the surface modified layer are disclosed. A photoconductor containing at least one of them in a larger amount than the intermediate layer is disclosed.
[0007]
Japanese Patent Application Laid-Open No. Hei 6-22623 discloses that a negatively charged electrophotographic photosensitive member containing amorphous silicon as a main component and containing less than 50 ppm boron between the photoconductive layer and the surface layer, or a conductive material. A technique is disclosed in which an excellent electrophotographic characteristic can be obtained by providing a hole trapping layer that does not contain an element that governs.
[0008]
These techniques have improved the electrical, optical, and photoconductive characteristics of the electrophotographic photosensitive member and the usage environment characteristics, and the image quality has been improved accordingly.
[0009]
In addition, various proposals have been made from the viewpoint of production technology, and various ideas have been devised for further improvement by changing the method of supplying high-frequency power.
[0010]
For example, Japanese Patent Laid-Open No. 56-045760 discloses a plurality of power sources having different frequencies as a power source for exciting a reactive gas, for example, 13.56 MHz and 400 kHz are applied to the same electrode to excite the reactive gas, A technique for forming a deposited film on a processing substrate is disclosed.
[0011]
On the other hand, in recent years, there has been a report of a plasma CVD method using a higher frequency high frequency power source (Plasma Chemistry and Plasma Processing, Vol. 7, No. 3, (1987), p267-273). The possibility that the deposition rate can be improved without degrading the performance of the deposited film by using higher than 13.56 MHz has been shown and is attracting attention. By this method, it is expected that the cost reduction and quality improvement of the product can be achieved at the same time.
[0012]
For example, Japanese Patent Application Laid-Open No. 6-287760 discloses a PCVD apparatus and method using a VHF band frequency which can be used for forming an a-Si electrophotographic photoreceptor.
[0013]
Japanese Patent Laid-Open No. 7-074159 discloses an example of a combination of the above-described method using two types of high-frequency power and a high-frequency high-frequency in a plasma processing method for cleaning a substrate. A technology is disclosed in which high-frequency power and low-frequency power, for example, 60MHz and 400kHz high-frequency power are supplied to the electrodes, and the self-bias voltage that determines the collision energy of positive ions is controlled by changing the power value of the low-frequency power. ing.
[0014]
[Problems to be solved by the invention]
However, conventional electrophotographic photoreceptors composed of a-Si-based materials have dark, resistance, photosensitivity, photoresponsiveness, and other electrical, optical, photoconductive characteristics, and usage environment characteristics. Although the characteristics are individually improved in terms of stability over time and durability, there is still room for further improvement in improving the overall characteristics.
[0015]
In recent years, with the spread of computers and the networking of offices, the electrophotographic apparatus is required not only as a conventional analog copying machine but also to be digitized to serve as a facsimile or printer, Furthermore, since a digital full-color copying machine is required for full-color output of digitized information, an electrophotographic photosensitive member corresponding to the digital full-color photocopier is desired.
[0016]
However, when a conventional electrophotographic photosensitive member is used in a digital system, the following problems are raised.
[0017]
For example, in a digital full-color copying machine, as one of the process conditions, a plurality of developing units are provided around the electrophotographic photosensitive member or a large developing unit is used, so that the distance from the charging unit to the developing unit is easily increased. It may become. For this reason, in order to compensate for the potential drop from the charger to the developer, it is necessary to increase the charging potential more than before, and also to increase the photosensitivity.
[0018]
Further, in a situation where the digital copying machine is increasing in speed and life, for example, fusion may occur depending on the usage environment and the configuration of the electrophotographic apparatus main body under all circumstances. Fusing means that the toner melts and adheres to the surface of the electrophotographic photosensitive member during long-term use, and depending on the degree of adhesion, a fusing mark appears in a solid white image or a halftone image. It will cause trouble. When fusion occurs in this way and appears on the image, the service person must go to the customer to perform maintenance, resulting in an increase in cost. Further, since the photoconductor is removed from the main body of the electrophotographic apparatus and maintenance is performed, there is a risk that the photoconductor may become unusable due to a dent in the work. Furthermore, since the color toner used in the digital full-color electrophotographic apparatus uses a low-melting toner, it is in an environment where fusion is more likely to occur than before, and countermeasures against fusion are required.
[0019]
Further, in the conventional electrophotographic photosensitive member, when the exposure amount is increased in order to obtain an image with high contrast from a color background document, a large amount of light carriers are generated by irradiation of strong exposure, and the portion where the light carriers are easy to move. There is a case in which a phenomenon occurs in which the character portion is blurred and the image portion at the time of strong exposure occurs in which the character portion is blurred. This intense exposure image flow is particularly important to control the composition ratio of atoms contained in the surface layer of the electrophotographic photosensitive member and the content of the impurity element to be added, and it is important to control it in accordance with the production conditions. .
[0020]
In addition, when charging is performed using a corona charger in an electrophotographic apparatus, the surface of the photoreceptor is chemically activated by the ozone product, so that slight impact, friction, etc. may occur depending on the use conditions. In some cases, the surface of the electrophotographic photosensitive member may be slightly cracked, and may not be practically used as an electrophotographic photosensitive member.
[0021]
Therefore, when designing an electrophotographic photosensitive member, it is necessary to make improvements from a comprehensive viewpoint such as the layer structure of the electrophotographic photosensitive member and the chemical composition of each layer so that the above-described problems are solved. In particular, optimization of the composition of the surface layer, the concentration of the impurity elements, and the manufacturing conditions may be required.
[0022]
As for the manufacturing method, the plasma CVD method using the frequency in the VHF band can obtain a film with better characteristics depending on conditions than in the case of using the RF band. Therefore, an optimized manufacturing method is expected. For example, the chemical composition required for the surface layer, the concentration of impurity elements, etc. may differ from the film obtained by the conventional fabrication method. Further, when the VHF frequency is used, the characteristic unevenness becomes a problem. The fact is that there are many unclear points. Therefore, it has been required to establish a surface layer that can obtain optimum electrophotographic characteristics when using a frequency in the VHF band.
[0023]
An object of the present invention is to solve various problems associated with the above-described conventional electrophotographic photosensitive member composed of a-Si.
[0024]
In other words, the main object of the present invention is to improve the image quality by reducing the microcracks generated on the surface of the photosensitive member surface while improving the chargeability, the sensitivity and reducing the characteristic unevenness at a high level, and also reducing the flow of intensely exposed images, fusing and the photoreceptor surface. It is an object of the present invention to provide an electrophotographic photosensitive member made of a non-single crystal material having a silicon atom as a base material, and a method for manufacturing the same.
[0025]
[Means for Solving the Problems]
The method for producing an electrophotographic photosensitive member and the electrophotographic photosensitive member of the present invention are characterized by the following configurations in order to solve the above-described problems.
[0026]
(1) exhaust A conductive substrate is installed in a possible reaction vessel, and plasma is generated by the high-frequency power supplied to the high-frequency electrode. On the photoconductive layer provided in Carbon atom When, Periodic table group 13 element or group 15 element And Containing silicon atoms Non-single crystal film A first surface layer made of silicon and silicon atoms containing carbon atoms are used as a base. Non-single crystal film In the method for producing an electrophotographic photoreceptor in which the second surface layer consisting of
Within the stratum Forming the first surface layer in a region satisfying a relationship in which the optical band gap increases with an increase in carbon atoms contained in Within the stratum And forming the second surface layer in a region satisfying a relationship in which the optical band gap decreases with an increase in carbon atoms contained in the electrophotographic photosensitive member.
[0027]
(2) The electrophotographic photosensitive member according to (1) above, wherein the first surface layer and the second surface layer form a surface layer having substantially the same value. Manufacturing method.
[0028]
(3) The electron according to any one of (1) to (2) above, wherein a difference in optical band gap between the first surface layer and the second surface layer is 0.3 eV or less. A method for producing a photographic photoreceptor.
[0029]
(4) The above-mentioned (1) to (3), wherein the periodic surface group 13 element contained in the first surface layer is a boron atom, and the group 15 element is a phosphorus atom. The method for producing an electrophotographic photosensitive member according to any one of the above.
[0030]
(5) In any one of the above (1) to (4), in the first surface layer, the content of a Group 13 element in the periodic table with respect to silicon atoms is not less than 100 atoms ppm and not more than 30000 atoms ppm A method for producing the electrophotographic photoreceptor according to claim 1.
[0031]
(6) In any one of the above (1) to (4), the content of the Group 15 element of the periodic table with respect to silicon atoms in the first surface layer is not less than 100 atoms ppm and not more than 30000 atoms ppm A method for producing the electrophotographic photoreceptor according to claim 1.
[0032]
(7) The method for producing an electrophotographic photosensitive member according to any one of (1) to (6) above, wherein the high frequency power supplied to the high frequency electrode has an oscillation frequency of 30 MHz to 250 MHz.
[0033]
(8) Said The high-frequency power includes at least two high-frequency power having a frequency of 30 MHz to 250 MHz and is within the frequency range. these For the high-frequency power having the largest power value and the next largest power value among the power values of the high-frequency power, the power value of the high-frequency power having the higher frequency is P1, and the power value of the high-frequency power having the lower frequency is the power value. When P2, the power values P1 and P2 satisfy the condition of 0.1 ≦ P2 / (P1 + P2) ≦ 0.9. Above (7) Of the negatively charged electrophotographic photosensitive member Manufacturing Method.
[0034]
(9) On the conductive substrate, A photoconductive layer; Carbon atom When, Periodic table group 13 element or group 15 element When, Based on silicon atoms containing Non-single crystal film A first surface layer comprising When, Provided on the first surface layer and based on silicon atoms containing carbon atoms Non-single crystal film A second surface layer comprising And having In electrophotographic photoreceptors,
The first surface layer is formed in a region satisfying a relationship in which an optical band gap increases with an increase in carbon atoms contained in the layer, and the second surface layer is contained in the layer. An electrophotographic photoreceptor characterized in that it is formed in a region satisfying a relationship in which the optical band gap decreases as the number of carbon atoms increases.
[0035]
(10) The electrophotographic photosensitive member according to (9) above, wherein the optical band gaps of the first surface layer and the second surface layer have substantially the same value.
[0036]
(11) The electron according to any one of (9) to (10) above, wherein a difference in optical band gap between the first surface layer and the second surface layer is 0.5 eV or less. Photoconductor.
[0037]
(12) The above-mentioned (9) to (11), wherein the periodic surface group 13 element contained in the first surface layer is a boron atom, and the group 15 element is a phosphorus atom. The electrophotographic photosensitive member according to any one of the above.
[0038]
(13) In any one of the above (9) to (12), in the first surface layer, the content of a Group 13 element in the periodic table with respect to silicon atoms is 100 atom ppm or more and 30000 atom ppm or less An electrophotographic photoreceptor according to any one of the above.
[0039]
(14) In any one of the above (9) to (12), the content of the Group 15 element with respect to silicon atoms in the first surface layer is not less than 100 atoms and not more than 30000 atoms. Electrophotographic photoreceptor.
[0040]
(15) The first surface layer contains a Group 13 element in the periodic table, and is used as a negatively charged electrophotographic photosensitive member, according to any one of (9) to (13) above Electrophotographic photoreceptor.
[0041]
(Action)
The inventors of the present invention investigated the correlation between the role, configuration, and manufacturing method of the two-layered surface layer and the characteristics of the electrophotographic photoreceptor over various conditions.
[0042]
The surface layer of the electrophotographic photosensitive member serves as a charge injection blocking layer that prevents the injection of charges from the surface portion of the photosensitive member to the inside during the charging process, as well as oxygen, water vapor, moisture in the air, ozone In addition, it has a function of preventing molecular species generally present in the ambient atmosphere from directly contacting or adsorbing to the surface of the photoconductive layer, and also serves as a protective layer for reducing mechanical breakdown and wear. In view of this, the inventors of the present invention have been diligently studied by adopting a structure of a surface layer that is functionally separated so as to correspond to the role. Specifically, as the first surface layer having a charge injection blocking function and the second surface layer having a role as a surface protective layer, the first surface layer has an electric charge to obtain a surface charge blocking capability. By adding an impurity element that controls conductivity, the chargeability was improved, and the second surface layer was intended to improve wear resistance and mechanical strength. There were many unclear points and I could not find a satisfactory relationship.
[0043]
Therefore, first, the present inventors changed the composition ratio of carbon atoms and silicon atoms contained in the surface layer, while the performance as the first surface layer, the performance of the second surface layer, and the combination of these two layers. The synergistic effect by was investigated in detail. As a result, when the first surface layer is formed in a region where the optical band gap increases as the amount of carbon contained in the surface layer increases, the effect of adding an impurity element that effectively controls conductivity is obtained. Therefore, the antistatic performance is improved, and the resistance value of the film is optimized, so that the exposure of the strong exposure image is suppressed. In addition, when the second surface layer is formed in a region where the optical band gap decreases as the amount of carbon contained in the surface layer increases, fusion occurs due to improved wear resistance and mechanical strength. It has been found that further improvement of sensitivity and suppression of microcracks generated on the surface of the photoreceptor can be achieved at the same time.
[0044]
In the present invention, in the case of an electrophotographic photosensitive member for negative charging, the impurity element for controlling the conductivity added to the first surface layer contains a Group 13 element in the periodic table, and the content thereof is a silicon atom. In contrast, it may be added so that it becomes 100 atom ppm or more and 30000 atom ppm or less. The content of the group 13 element in the periodic table with respect to silicon atoms is preferably 100 atom ppm or more from the viewpoint of obtaining sufficient stopping power to prevent charge injection from the surface, and from the viewpoint of preventing strong exposure image flow. The atomic ppm or less is preferable.
[0045]
On the other hand, in the case of an electrophotographic photosensitive member for positive charging, the impurity element for controlling the conductivity added to the first surface layer contains a Group 15 element in the periodic table, and the content is based on silicon atoms. It may be added so that it becomes 100 atom ppm or more and 30000 atom ppm or less. The content of Group 15 elements in the periodic table relative to silicon atoms is preferably 100 atom ppm or more from the viewpoint of obtaining sufficient stopping power to prevent charge injection from the surface, and from the viewpoint of preventing strong exposure image flow 30000 The atomic ppm or less is preferable.
[0046]
In addition, in the conventional surface layer, an impurity element is added at a considerably high concentration to prevent charge injection from the surface. However, if it is not added properly, the stress of the film may be increased in some cases, resulting in microcracks. There was a case of causing. However, in the first surface layer of the present invention, an increase in the stress difference can be prevented by adding an impurity element in a region that appropriately satisfies the relationship between the content of carbon atoms contained in the film and the optical band gap. It seems that
[0047]
Further, the present inventors have investigated the fusing phenomenon, and it has become clear that fusing may occur depending on the conventional conditions for forming the second surface layer. As a result of organizing these phenomena in light of the formation conditions, the second surface layer is formed in a region satisfying the relationship in which the optical band gap decreases as the carbon atoms contained in the film increase. Only when the film was formed, an effect was seen in suppressing fusion.
[0048]
In addition, in the combination of the first surface layer and the second surface layer, the difference in optical band gap between the two layers is made as small as possible, so that the stopping power can be further improved and the charging performance can be improved. I found out that The reason why the effect is obtained is that the smaller the difference between the optical band gaps of the first surface layer and the second surface layer, the more directly the change in Fermi level due to the impurity element doped in the first surface layer. It will affect the size of the barrier. For this reason, it is considered that an improvement in the stopping power can be obtained by increasing the barrier between the first surface layer and the second surface layer. In addition, combining the first surface layer and the second surface layer, the carrier travel is optimally controlled, so that the sensitivity can be improved.
[0049]
In addition, the present inventor studied various manufacturing methods in order to further improve the surface layer.
[0050]
As a result, when the first surface layer and the second surface layer are formed in the region defined by the present invention, when the plasma CVD method using the high frequency in the VHF band is used, the high frequency in the RF band is used. The above effect can be exhibited more than the above, and the deposition rate can be increased. Although it is not clear as to the cause of this, it is thought that one of the reasons is that high-energy plasma is formed by using a frequency in the VHF band, thereby improving the decomposition efficiency of methane gas that is difficult to be decomposed. This increases the number of good and optimal active species in the plasma, improves the film structure itself, and the proportion of elements belonging to Group 13 or Group 15 of the periodic table doped in three or four coordinates. I guess that different things may have an effect. Therefore, as a specific oscillation frequency range in the present invention, a VHF band of 30 MHz or more and 250 MHz or less is more preferable.
[0051]
However, when the frequency in the VHF band is used, a deposited film can be formed at high speed with high quality, but unevenness due to standing waves may occur on the substrate surface. In order to avoid such a problem, it has been found that the problem can be effectively suppressed by superposing high frequencies of a plurality of different frequencies.
[0052]
Further, in the present invention, as long as the standing wave suppression effect is obtained, the frequency type of the high-frequency power to be used is not particularly limited, but the high-frequency power in a certain frequency range is set to a certain power value ratio. In particular, the first high-frequency power and the second high-frequency power are in a frequency range in which a high deposition rate can be expected, and both are in a frequency range in which the same active species can be generated. It is most desirable that their power balance be set appropriately.
[0053]
In addition, by superimposing the third and fourth high-frequency power having a more appropriate frequency and power value, it is possible to further increase the standing wave suppression effect or obtain other effects (for example, bias effect) depending on the case. However, in order to show the basic concept and operation of the present invention, the case where two different frequencies are used will be described below.
[0054]
When the frequency of the first high-frequency power is f1, the power value is P1, the frequency of the second high-frequency power is f2, and the power value is P2 (where f1> f2), the first and second high-frequency powers For the desired frequency, the lower limit is preferably in the range of 30 MHz or more from the viewpoint of the quality of the deposited film and the deposition rate. On the other hand, if the upper limit is larger than 250 MHz, the attenuation in the traveling direction of the power becomes remarkable, the deviation of the attenuation rate from the high frequency power of different frequencies becomes remarkable, and a sufficient uniformizing effect cannot be obtained. . Therefore, it is preferable to set the frequency to 250 MHz or less because the superposition effect can be effectively obtained.
[0055]
In addition, power values P1 and P2 of two high-frequency powers (however, among the high-frequency powers supplied to the high-frequency electrodes, the highest power value P1 and the next power value among the high-frequency powers within the above-mentioned frequency range) The power value P2 is large.
As for the range of the ratio, the value of P2 with respect to the total power value (P1 + P2) of the two high-frequency powers is preferably 0.1 or more and 0.9 or less. That is, when the ratio of P2 becomes small, it approaches the case of only P1, and the standing wave suppression effect becomes small. On the other hand, if the ratio of P2 becomes too large, it becomes similar to the case of P2 alone, and the effect becomes small. From experimental facts, it was found that the standing wave suppression effect was remarkably obtained by setting at least one high frequency power to 10% or more of the total power of the two. Further, it has become clear from experiments that P2 / (P1 + P2) is most preferably 0.2 or more and 0.7 or less.
[0056]
Further, when the two high-frequency powers are combined, the effects of the present invention can be sufficiently obtained, but a third high-frequency power can also be combined.
[0057]
Through the improvements as described above, the present invention can achieve a high level of compatibility between an improvement in charging ability (blocking ability) and sensitivity of an electrophotographic photosensitive member and suppression of unevenness of characteristics, as well as image flow, fusion, and surface of the photosensitive member. The image quality is dramatically improved by suppressing the generation of microcracks that occur in the product, and all the problems in the prior art described above are solved, and extremely excellent electrical and optical characteristics, image quality and durability are achieved. The present invention provides an electrophotographic photosensitive member having high performance and environmental resistance, and a production method capable of obtaining it with good reproducibility.
[0058]
DETAILED DESCRIPTION OF THE INVENTION
(Example embodiment)
Hereinafter, the method for producing an electrophotographic photosensitive member of the present invention will be described in detail with reference to the drawings.
[0059]
FIG. 1 is a schematic configuration diagram for explaining an example of a preferred layer configuration of an electrophotographic photosensitive member produced by the production method of the present invention.
[0060]
In the electrophotographic photosensitive member 100 of FIG. 1, a light receiving layer 102 is provided on a conductive substrate 101. The photoreceptive layer 102 includes a lower charge injection blocking layer 106 based on silicon, a photoconductive layer 103 based on silicon, a first surface layer 104 based on silicon and carbon, and a second surface layer. 105 are provided in this order.
[0061]
<Substrate>
The substrate used in the present invention may be conductive or electrically insulating. Examples of the conductive substrate include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel.
[0062]
Examples of the electrically insulating material include films or sheets of synthetic resins such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, and polyamide, glass, and ceramic. In the present invention, at least the surface of the electrically insulating substrate on the side where the photosensitive layer is formed can be subjected to a conductive treatment and used as a substrate.
[0063]
<Lower charge injection blocking layer>
In the present invention, a lower charge injection blocking layer 106 that functions to block charge injection from the substrate 101 side is formed on the conductive substrate 101. Provide Is effective. The lower charge injection blocking layer 106 has a function of blocking charge injection from the substrate 101 side to the photoconductive layer 103 side when the photoreceptive layer 102 is subjected to charging treatment with a certain polarity on its free surface. Yes.
[0064]
Examples of the substance that can be a Si supply gas used in forming the lower charge injection blocking layer of the present invention include SiH. _Four , Si ₂ H ₆ , Si _Three H ₈ , Si _Four H _Ten It is mentioned that silicon hydrides (silanes) that are in a gas state or can be gasified are effectively used. Further, SiH can be used in terms of easy handling at the time of layer preparation and good Si supply efficiency. _Four , Si ₂ H ₆ Is preferable.
[0065]
The lower charge injection blocking layer 106 contains a relatively large amount of impurities that control conductivity using silicon as a base material compared to the photoconductive layer 103. As the impurity element contained in the lower charge injection blocking layer 106, a group 13 element or a group 15 element in the periodic table can be used. In the present invention, the content of the impurity element contained in the lower charge injection blocking layer 106 is appropriately determined as desired so that the object of the present invention can be effectively achieved. It is desirable that the atomic pressure is not less than ppm and not more than 10,000 atom ppm, more preferably not less than 50 atom ppm and not more than 7000 atom ppm, and most preferably not less than 100 atom ppm and not more than 5000 atom ppm.
[0066]
Specifically, as a source material for introducing such group 13 atoms, for introducing boron atoms, B ₂ H ₆ , B _Four H _Ten , B _Five H ₉ , B _Five H ₁₁ , B ₆ H _Ten , B ₆ H ₁₂ , B ₆ H ₁₄ Boron hydride such as BF _Three , BCl _Three , BBr _Three And boron halides. In addition, AlCl _Three , GaCl _Three , Ga (CH _Three ) _Three , InCl _Three , TlCl _Three Etc. can also be mentioned.
[0067]
As a raw material for introducing a group 15 atom, it is effective to use PH for introducing a phosphorus atom. _Three , P ₂ H _Four Phosphorus hydrides such as PF _Three , PF _Five , PCl _Three , PCl _Five , PBr _Three , PBr _Five , PI _Three And the like. In addition, AsH _Three , AsF _Three , AsCl _Three , AsBr _Three , AsF _Five , SbH _Three , SbF _Three , SbF _Five , SbCl _Three , SbCl _Five , BiH _Three , BiCl _Three , BiBr _Three Can also be mentioned as effective starting materials for introducing Group 15 atoms.
[0068]
Further, the lower charge injection blocking layer 106 can contain nitrogen and oxygen to improve the adhesion between the lower charge injection blocking layer 106 and the substrate 101. Further, in the case of an electrophotographic photosensitive member for negative charging, it is possible to have excellent stopping power by optimally containing nitrogen and oxygen without doping an impurity element. Specifically, the content of nitrogen and oxygen contained in the entire layer region of the lower charge injection blocking layer 106 is such that the sum of nitrogen and oxygen is 0.1 atomic% or more with respect to silicon atoms, more preferably 1.2. The charge blocking ability is improved by setting the atomic percentage to 40% by atom or more, more preferably 20% by atom or less.
[0069]
Further, hydrogen and / or halogen contained in the lower charge injection blocking layer 106 in the present invention compensates for dangling bonds existing in the layer, and has an effect of improving the film quality. The sum of the contents of atoms contained in the lower charge injection blocking layer 106 is preferably 1 atomic% or more, more preferably 5 atomic% or more, and still more preferably 10 atomic% or more with respect to silicon atoms. On the other hand, 50 atomic% or less is preferable, 40 atomic% or less is more preferable, and 30 atomic% or less is still more preferable.
[0070]
In the present invention, the thickness of the lower charge injection blocking layer 106 is preferably 0.1 to 5 [mu] m, more preferably 0.3 to 4 [mu] m, optimal in view of obtaining desired electrophotographic characteristics and economic effects. Is preferably 0.5 to 3 μm. If the layer thickness is less than 0.1 μm, the ability to prevent injection of charges from the substrate 101 becomes insufficient, and sufficient charging ability cannot be obtained. Even if the layer thickness is greater than 5 μm, no improvement in electrophotographic characteristics can be expected. On the contrary, there is a possibility that adverse effects such as an increase in residual potential may occur.
[0071]
<Photoconductive layer>
The photoconductive layer 103 in the electrophotographic photoreceptor 100 of the present invention is composed of a non-single crystalline film based on silicon atoms, and the film needs to contain hydrogen atoms and / or halogen atoms. This is indispensable for compensating dangling bonds of silicon atoms and improving layer quality, in particular, photoconductivity and charge retention characteristics. The content of hydrogen atom or halogen atom, or the total amount of hydrogen atom and halogen atom is preferably 10 to 40 atom%, more preferably 15 to 25 atom, based on the sum of silicon atom and hydrogen atom or / and halogen atom. % Is desirable. In order to control the amount of hydrogen atoms and / or halogen atoms contained in the photoconductive layer 103, for example, the temperature of the substrate 101, the reaction vessel of the raw material used to contain the hydrogen atoms and / or halogen atoms What is necessary is just to control the quantity introduce | transduced in, discharge electric power, etc.
[0072]
Examples of substances that can serve as Si supply gas used in the formation of the photoconductive layer of the present invention include SiH. _Four , Si ₂ H ₆ , Si _Three H ₈ , Si _Four H _Ten It is mentioned that silicon hydrides (silanes) that are in a gas state or can be gasified are effectively used. Further, SiH can be used in terms of easy handling at the time of layer preparation and good Si supply efficiency. _Four , Si ₂ H ₆ Is preferable.
[0073]
In the present invention, the photoconductive layer 103 may contain an impurity element for controlling conductivity as required. As the impurity element to be contained, a group 13 element or a group 15 element in the periodic table can be used as in the case of the lower charge injection blocking layer 106. The content of the impurity element contained in the photoconductive layer 103 is preferably 1 × 10 ^-2 1 × 10 atom ppm or more ^Four Atomic ppm or less, more preferably 5 × 10 ^-2 Atomic ppm or more 5 × 10 ^Three Atomic ppm or less, optimally 1 × 10 ^-1 1 × 10 atom ppm or more ^Three It is desirable that it be less than atomic ppm.
[0074]
Specifically, as a source material for introducing such group 13 atoms, for introducing boron atoms, B ₂ H ₆ , B _Four H _Ten , B _Five H ₉ , B _Five H ₁₁ , B ₆ H _Ten , B ₆ H ₁₂ , B ₆ H ₁₄ Boron hydride such as BF _Three , BCl _Three , BBr _Three And boron halides. In addition, AlCl _Three , GaCl _Three , Ga (CH _Three ) _Three , InCl _Three , TlCl _Three Etc. can also be mentioned.
[0075]
As a raw material for introducing a group 15 atom, it is effective to use PH for introducing a phosphorus atom. _Three , P ₂ H _Four Phosphorus hydrides such as PF _Three , PF _Five , PCl _Three , PCl _Five , PBr _Three , PBr _Five , PI _Three And the like. In addition, AsH _Three , AsF _Three , AsCl _Three , AsBr _Three , AsF _Five , SbH _Three , SbF _Three , SbF _Five , SbCl _Three , SbCl _Five , BiH _Three , BiCl _Three , BiBr _Three Can also be mentioned as effective starting materials for introducing Group 15 atoms.
[0076]
In the present invention, the layer thickness of the photoconductive layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 10 μm to 50 μm, more preferably 20 μm to 45 μm, Optimally, it is desirable to be 25 μm or more and 40 μm or less.
[0077]
<First surface layer>
In the electrophotographic photoreceptor 100 in which the effects of the present invention can be obtained, the surface layer needs to be composed of the first surface layer 104 and the second surface layer 105. Further, the first surface layer 104 and the second surface layer 105 are made of a non-single crystalline film based on silicon atoms and carbon atoms, so that a common configuration of silicon atoms forming the photoconductive layer 103 is formed. Since the element is included, chemical stability is ensured at the laminated interface.
[0078]
The first surface layer 104 has a function of preventing the charge from being injected from the outermost surface side to the photoconductive layer 103 side when the electrophotographic photosensitive member is subjected to charging treatment on the outermost surface. In order to provide such a function, the first surface layer 104 is required to have a certain level of high-resistance film characteristics, and at the same time, it is necessary to set the charge resistance to an appropriate range by adding an impurity element.
The first surface layer 104 of the present invention needs to be formed in a region that satisfies the relationship in which the optical band gap increases as the number of carbon atoms contained in the layer increases. By forming the first surface layer 104 in this region, the impurity element can be efficiently added, and the stopping power can be improved. Since the impurity element for controlling the conductivity contained in the first surface layer 104 is uniformly distributed in the first surface layer 104, a constant amount may be supplied at all times when the layer is formed. Alternatively, the flow rate of the gas added for non-uniform distribution may be changed over time.
[0079]
Examples of the substance that can be a Si supply gas used in the formation of the first surface layer of the present invention include SiH. _Four , Si ₂ H ₆ , Si _Three H ₈ , Si _Four H _Ten It is mentioned that silicon hydrides (silanes) that are in a gas state or can be gasified are effectively used. Further, SiH can be used in terms of easy handling at the time of layer preparation and good Si supply efficiency. _Four , Si ₂ H ₆ Is preferable.
[0080]
Further, examples of the carbon supply gas include methane gas.
[0081]
Further, in the combination of the first surface layer and the second surface layer of the present invention, it is preferable to reduce the difference in optical band gap between the two layers as much as possible from the viewpoint of further improving the stopping power. It is preferable that the difference in target band gap is 0.3 eV or less. The range of the optical band gap of the first surface layer formed in the present invention varies depending on the production conditions, but is preferably in the range of 1.9 eV to 2.6 eV.
[0082]
Further, the impurity element for controlling the conductivity contained in the first surface layer 104 of the present invention includes atoms belonging to Group 13 of the periodic table giving p-type conductivity and periodic rules giving n-type conductivity. Atoms belonging to Table 15 can be used.
[0083]
Specific examples of group 13 elements in the periodic table include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Boron, aluminum, and gallium are particularly preferable. Is preferred.
[0084]
Specific examples of Group 15 elements in the periodic table include phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), etc., and phosphorus and arsenic are particularly preferable.
In order to structurally introduce Group 13 elements and Group 15 elements of the periodic table, a raw material gas for introducing Group 13 elements such as diborane (B ₂ H ₆ Gas and a raw material gas for introducing a Group 15 element such as phosphine (PH _Three ) A gas may be introduced into the reaction vessel together with another gas for forming the photoconductive layer 103.
[0085]
Specifically, as a source material for introducing such group 13 atoms, for introducing boron atoms, B ₂ H ₆ , B _Four H _Ten , B _Five H ₉ , B _Five H ₁₁ , B ₆ H _Ten , B ₆ H ₁₂ , B ₆ H ₁₄ Boron hydride such as BF _Three , BCl _Three , BBr _Three And boron halides. In addition, AlCl _Three , GaCl _Three , Ga (CH _Three ) _Three , InCl _Three , TlCl _Three Etc. can also be mentioned.
[0086]
As a raw material for introducing a group 15 atom, it is effective to use PH for introducing a phosphorus atom. _Three , P ₂ H _Four Phosphorus hydrides such as PF _Three , PF _Five , PCl _Three , PCl _Five , PBr _Three , PBr _Five , PI _Three And the like. In addition, AsH _Three , AsF _Three , AsCl _Three , AsBr _Three , AsF _Five , SbH _Three , SbF _Three , SbF _Five , SbCl _Three , SbCl _Five , BiH _Three , BiCl _Three , BiBr _Three Can also be mentioned as effective starting materials for introducing Group 15 atoms.
[0087]
In the present invention, the content of the impurity element for controlling the conductivity contained in the first surface layer 104 is, in order to achieve the effect of the present invention, in the case of an electrophotographic photoreceptor for negative charging, silicon atoms. It is desirable to appropriately control the content of Group 13 elements in the periodic table to 100 to 30,000 atoms ppm. Improve the ability to prevent charge injection from the surface when the content of atoms belonging to Group 13 of the periodic table for silicon atoms is 100 atoms ppm or more, and if it is less than 30000 atoms ppm, This is preferable because it can be prevented. In the case of a positively charged electrophotographic photosensitive member, it is desirable to appropriately control the content of atoms belonging to Group 15 of the periodic table with respect to silicon atoms to be from 100 atom ppm to 30000 atom ppm. Improve the ability to prevent charge injection from the surface when the content of atoms belonging to Group 13 of the periodic table for silicon atoms is 100 atoms ppm or more, and if it is less than 30000 atoms ppm, This is preferable because it can be prevented.
[0088]
The thickness of the first surface layer 104 is determined and determined comprehensively depending on the layer thicknesses of the photoconductive layer 103 and the second surface layer 105 and the required electrophotographic characteristics. It is desirable that the thickness be 0.01 μm or more and 1 μm or less because the ability to prevent injection is sufficiently exhibited and the image quality is not affected. If the layer thickness is less than 0.01 μm, the charge injection ability from the surface side becomes insufficient and sufficient charging ability cannot be obtained, and even if it is thicker than 1 μm, no improvement in electrophotographic characteristics can be expected. The characteristics such as sensitivity may be deteriorated.
[0089]
<Second surface layer>
The second surface layer 105 has excellent characteristics mainly in repeated use characteristics, electrical pressure resistance, use environment characteristics, durability, and moisture resistance. In order to obtain such characteristics, it is necessary to have characteristics that have a certain degree of hardness and lubricity.
[0090]
The second surface layer 105 of the present invention needs to be formed in a region that satisfies the relationship in which the optical band gap decreases as the number of carbon atoms contained in the layer increases. By forming the second surface layer 105 in this region, it is excellent in hardness and further improved in lubricity and can prevent fusion.
[0091]
Further, the silicon supply gas used in the formation of the second surface layer of the present invention includes, for example, silane gas, and the carbon supply gas includes, for example, methane gas.
[0092]
The layer thickness of the second surface layer 105 in the present invention is preferably 0.01 μm or more and 3 μm or less, more preferably 0.05 μm or more and 2 μm or less, and further preferably 0.1 μm or more and 1 μm or less. Is. If the layer thickness is less than 0.01 μm, the surface layer is likely to be lost due to wear during use of the light receiving member, and if it exceeds 3 μm, the electrophotographic characteristics may be degraded due to an increase in residual potential. is there.
[0093]
The range of the optical band gap of the second surface layer formed in the present invention varies depending on the production conditions, but is preferably in the range of 2.0 eV to 2.6 eV.
[0094]
In order to form the first surface layer 104 and the second surface layer 105 having the characteristics that can achieve the object of the present invention, the temperature of the substrate 101, the gas pressure in the reaction vessel, and the discharge power are appropriately set as desired. Must be set.
[0095]
Further, the optimum range of the temperature of the substrate 101 is appropriately selected according to the layer design. In a normal case, it is preferably 150 to 350 ° C., more preferably 180 to 330 ° C., and most preferably 200 to 300 ° C. Is desirable.
[0096]
Similarly, the optimum range of the gas pressure in the reaction vessel is appropriately selected according to the layer design. However, when a high frequency in the VHF band is used, preferably 1 × 10 ^-2 Pa or more 5 × 10 ² Pa or less, preferably 5 × 10 ^-2 Pa or more 5 × 10 ¹ Pa or less, optimally 1 × 10 ^-1 Pa or more 1 × 10 ¹ It is preferable to set it to Pa or less.
[0097]
The first surface layer 104 and the second surface layer 105 of the present invention can be produced by, for example, a plasma CVD method using a source gas with a frequency in the RF band, but the effects of the present invention are maximized. Therefore, it is preferable to use a VHF band frequency excellent in hydrocarbon decomposability, and more preferably, a plurality of high frequency powers having different frequencies in the VHF band are appropriately controlled and simultaneously supplied to the high frequency electrode. It is most preferable to make them.
[0098]
<Deposited film forming device>
Next, an apparatus for forming an electrophotographic photoreceptor and a film forming method will be described in detail.
[0099]
3 and 4 are schematic views of an embodiment of a deposited film forming apparatus that can be applied to the present invention.
[0100]
FIG. 3 is a schematic diagram of a deposited film forming apparatus using a plasma CVD method using a VHF band frequency as a power source, and FIG. 4 is a schematic diagram of a deposited film forming apparatus using a plasma CVD method using an RF band frequency.
[0101]
The deposited film forming apparatus of FIG. 3 is an apparatus in which a plurality of high-frequency electrodes 3114 are installed outside a reaction vessel 3111.
[0102]
An exhaust pipe 3112 is formed on the bottom surface of the cylindrical reaction vessel 3111, and the other end of the exhaust pipe 3112 is connected to an exhaust device (not shown). Six cylindrical substrates 3113 on which deposited films are formed are arranged concentrically so as to surround the central portion of the reaction vessel 3111.
[0103]
The side wall of the reaction vessel 3111 is made of a dielectric member, and examples of the material thereof include alumina, mullite, zirconia, cordierite, zircon-cordierite, silicon carbide, boron nitride, aluminum nitride, and beryllium mica-based ceramics. .
[0104]
The source gas is introduced into the reaction vessel via a source gas introduction pipe 3118 arranged concentrically in the reaction vessel 3111.
[0105]
For example, the high frequency power is synthesized from two high frequency power sources 3116 and 3117 having different frequencies through matching circuits in the matching box 3115 and arranged concentrically so as to surround the reaction vessel side wall via the power branch plate 3124. The high frequency electrode 3114 is supplied into the reaction vessel 3111.
[0106]
Further, in order to improve the vacuum processing stability in the initial stage of discharge, the power branch plate 3124 and the high frequency electrode 3114 may be connected via a capacitor.
[0107]
Formation of a deposited film in the case of using the apparatus of FIG. 3 can be performed by the following procedure.
[0108]
First, the cylindrical substrate 3113 is installed in the reaction vessel 3111, and the inside of the reaction vessel 3111 is exhausted through an exhaust pipe 3112 by an exhaust device (not shown). Subsequently, the cylindrical base 3113 is heated and controlled to a predetermined temperature by the heating element 3120.
[0109]
When the cylindrical substrate 3113 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 3111 via the source gas introduction pipe 3118. After confirming that the flow rate of the raw material gas is the set flow rate and that the pressure in the reaction vessel 3111 is stable, two predetermined high frequency power sources 3116 and 3117 having different oscillation frequencies are supplied to the high frequency electrode 3114 via the matching box 3115. Supply high frequency power. As a result, glow discharge occurs in the reaction vessel 3111, the source gas is excited and dissociated, and a deposited film is formed on the cylindrical substrate 3113.
[0110]
The deposited film forming apparatus of FIG. 4 is an apparatus in which a conductive substrate 4113 is installed in a reaction vessel.
[0111]
An exhaust pipe 4112 is formed on the bottom surface of the cylindrical reaction vessel, and the other end of the exhaust pipe 4112 is connected to an exhaust device (not shown).
[0112]
The source gas is introduced into the reaction vessel through the source gas introduction pipe 4118. Further, the high frequency power is supplied from the high frequency electrode 4114 into the reaction vessel via the matching box 4115.
[0113]
Formation of a deposited film in the case of using the apparatus of FIG. 4 can be performed by the following procedure.
[0114]
First, the cylindrical substrate 4113 is installed in the reaction vessel, and the inside of the reaction vessel is exhausted through the exhaust pipe 4112 by an exhaust device (not shown). Subsequently, the cylindrical base 4113 is heated and controlled to a predetermined temperature by the heating element 4120.
[0115]
When the cylindrical substrate 4113 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 4111 through the source gas introduction pipe 4118. After confirming that the flow rate of the source gas is the set flow rate and that the pressure in the reaction vessel is stable, a predetermined high-frequency power is supplied to the high-frequency electrode 4114 via the matching box 4115 from a high-frequency power source with an oscillation frequency of 13.56 MHz. To do. As a result, glow discharge occurs in the reaction vessel, the source gas is excited and dissociated, and a deposited film is formed on the cylindrical substrate 4113.
[0116]
As for the frequency of the present invention, it is preferable to use a high frequency in the VHF band, but it is preferable to simultaneously supply a plurality of high frequency powers having different oscillation frequencies to the same electrode. in this case,
The relationship between the oscillation frequencies of the high frequency power supplies 3116 and 3117 is that, for example, the high frequency power supply 3116 supplies a first high frequency power (frequency f1, power value P1), and 3117 indicates a second high frequency power (frequency. f2 and power value P2) when the second high-frequency power supply is supplied,
30MHz ≦ f2 <f1 ≦ 250MHz
0.1 ≦ P2 / (P1 + P2) ≦ 0.9
A power supply that can be used is used.
[0117]
Further, the first high frequency power supply may be provided with a high pass filter having a cutoff frequency characteristic lower than f1 and higher than f2. Similarly, the second high-frequency power supply may be provided with a low-pass filter having a cutoff frequency characteristic higher than f2 and lower than f1. Higher frequency selectivity is more preferable because the other power that wraps around each high-frequency power source can be reduced.
[0118]
Also, the power range is
0.2 ≦ P2 / (P1 + P2) ≦ 0.7
Is more preferable.
[0119]
【Example】
Examples The effects of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0120]
(Example 1)
Using the deposited film forming apparatus shown in FIG. 3, an electrophotographic photosensitive member for negative charging was produced on a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm according to the method for producing an electrophotographic photosensitive member of the present invention.
[0121]
First, a surface layer containing carbon atoms and silicon atoms is deposited on a silicon wafer substrate and a Corning 7059 glass substrate, and the carbon atom content (C / (Si + C)), that is, the sum of silicon atoms and carbon atoms. The relationship between the carbon atom ratio (C / (Si + C)) and the optical band gap was investigated. The optical band gap of the 7059 glass substrate was measured with a UV-visible measuring device, and the carbon atom content (C / (Si + C)) of the silicon wafer substrate was measured with an RBS (Rutherford backscattering) device. The surface layer was prepared under the conditions shown in Table 1, and the carbon atom content (C / (Si + C)) was changed by changing the gas flow rate. When the relationship between the carbon atom content (C / (Si + C)) and the optical band gap was examined under these conditions, the result of FIG. 2 was obtained.
[0122]
Next, using the same apparatus, a lower charge injection blocking layer and a photoconductive layer were sequentially laminated on the aluminum cylinder according to the film forming procedure described above under the conditions shown in Table 2. Subsequently, according to the condition based on the relationship of FIG. 2, a first surface layer is formed in a region where the optical band gap increases as the carbon atom content (C / (Si + C)) increases. The second surface layer was sequentially laminated in a region where the optical band gap decreased as the carbon atom content (C / (Si + C)) increased. By changing the combination of the first surface layer and the second surface layer by the above procedure, a total of six types of electrophotographic photoreceptors for negative charging A to F were produced. In addition, diborane gas was used for the first surface layer as a gas species containing the Group 13 element of the periodic table, and 3000 atoms ppm was contained with respect to silicon atoms.
[0123]
(Comparative Example 1)
Similar to Example 1, a lower charge injection blocking layer and a photoconductive layer were sequentially laminated on an aluminum cylinder using the deposited film forming apparatus shown in FIG. 3 under the conditions shown in Table 2. Subsequently, in accordance with the condition based on the relationship of FIG. 2, the first surface layer and the first surface layer satisfying the region where the optical band gap increases as the carbon atom content (C / (Si + C)) increases. Two surface layers were sequentially laminated to produce a negatively charged electrophotographic photosensitive member.
[0124]
The surface layer produced in Comparative Example 1 is First surface layer of carbon atom content (C / (Si + C)) and carbon atom content (C / (Si + C)) shown in Table 4 A second surface layer was formed. In addition, diborane gas was used for the first surface layer as a gas species containing the Group 13 element of the periodic table, and 3000 atoms ppm was contained with respect to silicon atoms.
[0125]
(Comparative Example 2)
Similar to Example 1, a lower charge injection blocking layer and a photoconductive layer were sequentially laminated on an aluminum cylinder using the deposited film forming apparatus shown in FIG. 3 under the conditions shown in Table 2. Subsequently, in accordance with the conditions based on the relationship of FIG. 2, the first surface layer and the first surface layer satisfying the region where the optical band gap decreases as the carbon atom content (C / (Si + C)) increases. Two surface layers were sequentially laminated to produce a negatively charged electrophotographic photosensitive member.
[0126]
The surface layer produced in Comparative Example 2 is First surface layer of carbon atom content (C / (Si + C)) and carbon atom content (C / (Si + C)) shown in Table 4 A second surface layer was formed. In addition, diborane gas was used for the first surface layer as a gas species containing the Group 13 element of the periodic table, and 3000 atoms ppm was contained with respect to silicon atoms.
[0127]
(Comparative Example 3)
Similar to Example 1, a lower charge injection blocking layer and a photoconductive layer were sequentially laminated on an aluminum cylinder using the deposited film forming apparatus shown in FIG. 3 under the conditions shown in Table 2. Subsequently, a surface layer having the conditions shown in Table 3 was laminated in one layer without being divided into two layers as in the example, and a negatively charged electrophotographic photosensitive member was produced.
[0128]
In Comparative Example 3, high-frequency power was introduced at an oscillation frequency of 105 MHz only introduced into the high-frequency electrode.
[0129]
Characteristics of the negatively charged electrophotographic photosensitive member thus produced were evaluated as follows.
[0130]
<Chargeability>
The electrophotographic photosensitive member is installed in an electrophotographic apparatus (Canon GP405), the process speed is 200 mm / sec, the pre-exposure (LED with a wavelength of 660 nm), the light quantity is 4 lx · s, and the current value of the charger is −800 μA The surface potential of the photoconductor without irradiation of image exposure (semiconductor laser with a wavelength of 655 nm) was measured by a potential sensor of a surface electrometer (TREK's Model 344) set at the position of the developing unit, and this was used as the charging ability. .
[0131]
<Sensitivity>
After adjusting the current value of the charger so that the surface potential becomes −400 V (dark potential) under the above-mentioned conditions, the electrophotographic photosensitive member is irradiated with image exposure (semiconductor laser with a wavelength of 655 nm), and the image exposure light source The light amount was adjusted so that the surface potential was -50 V (bright potential), and the exposure amount at that time was defined as sensitivity.
[0132]
<Characteristic unevenness>
The charging ability was measured over the entire region of the photoreceptor in the bus bar direction, the maximum value and the minimum value for each average value were determined, and then (maximum value) / (minimum value) was determined. The characteristic having the maximum value was regarded as the characteristic unevenness. The closer the value is to 1, the better the uniformity.
[0133]
<Fusion>
Modify the pressing pressure of the cleaning blade of the electrophotographic apparatus (Canon GP405) to be 1/2 times, further change the environmental conditions to room temperature and low humidity environment of 25 ℃ / 10%, and use 1% original. This created an environment where fusion is likely to occur. An electrophotographic photosensitive member was installed in such an acceleration tester, and 100,000 sheets were endured. The image of the image and the surface of the electrophotographic photosensitive member during and after the endurance and the surface of the electrophotographic photosensitive member were observed with a microscope to observe the number of fusion occurrences.
[0134]
<Strong exposure image flow>
The evaluation of the strong exposure image flow is made by preparing a test chart in which the black portion and the white portion shown in FIG. 5 are arranged with a constant width a and narrowing the line width a with an electrophotographic apparatus (GP405 manufactured by Canon). The measurement was performed with the minimum line width a that can be reproduced and resolved on the copy image. That is, when the line width a is narrowed, if the line width a becomes equal to or smaller than a certain line width a, minute blur due to the image flow of the outline of the adjacent black portion on the image overlaps, effectively making the resolution impossible. The line width a at that time was used as an index representing the degree of image flow.
[0135]
<Micro crack>
Regarding the presence or absence of microcracks, the electrophotographic photosensitive member produced under each condition was left in a container adjusted to a temperature of −50 ° C. for 12 hours, and then immediately adjusted to a temperature of 80 ° C. and a humidity of 80%. Leave in for 2 hours. When this cycle was repeated 10 times and an image was produced with a halftone image, the number of minute cracks that appeared in the image was checked.
[0136]
For each item, a relative comparison was performed by setting the evaluation value of the negatively charged electrophotographic photosensitive member of Comparative Example 3 to 100.
[0137]
The results of Example 1 and Comparative Examples 1 to 3 are shown in Table 4. A first surface layer is formed in a region where the optical band gap increases as the carbon atom content (C / (Si + C)) increases, and the carbon atom content (C / (Si + C)) When the second surface is formed in a region where the optical bandgap decreases as the value increases, fusion, image flow, microcracks, etc. do not occur and very good results are obtained. Good results were also obtained for electrical characteristics. In addition, when the difference in optical band gap between the first surface layer and the second surface layer was 0.3 eV or less, particularly good results were obtained in terms of electrical characteristics.
[0138]
On the other hand, Comparative Example 1 formed with only the increased region of the optical band gap and Comparative Example 2 formed with only the decreased region have a smaller degree of improvement, and in Comparative Example 1, the fusion is worse than Comparative Example 3. Met.
[0139]
[Table 1]

[0140]
[Table 2]

[0141]
[Table 3]

[0142]
[Table 4]

(Example 2)
Using the deposited film forming apparatus shown in FIG. 3, a negatively charged electrophotographic photosensitive member was produced on a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm under the conditions shown in Table 5.
[0143]
First, a surface layer containing carbon atoms and silicon atoms is deposited on a silicon wafer substrate and a Corning 7059 glass substrate, and the relationship between the carbon atom content (C / (Si + C)) and the optical band gap is investigated. It was. In this example, the regions where the optical band gap increases and decreases as the carbon atom content (C / (Si + C)) increases are examined by changing the flow rates of silane gas and methane gas. The first surface layer is formed in a region where the optical band gap increases as the carbon atom content (C / (Si + C)) increases, and the second surface layer has a carbon atom content ( It is formed in a region where the optical band gap decreases as C / (Si + C)) increases, and the difference between the optical band gaps of the first surface layer and the second surface layer is 0.05 eV. It was combined as follows.
[0144]
In Example 2, the content of the Group 13 element of the periodic table with respect to the silicon atoms contained in the first surface layer is 50 atom ppm, 100 atom ppm, 5000 atom ppm, 10000 atom ppm, 30000 atom ppm, It was changed to 35000 atoms ppm. In this example, diborane gas was used as a gas species containing the Group 13 element of the periodic table.
[0145]
Table 6 shows the results of relative evaluation performed on each of the produced electrophotographic photosensitive members in the same manner as in Example 1. As is clear from Table 6, the negatively charged electrophotographic photosensitive member having the first surface layer in which the content of the Group 13 element with respect to the silicon atom is 100 atomic ppm to 30000 atomic ppm is In particular, an effect was obtained with respect to improvement of image quality and suppression of image flow.
[0146]
[Table 5]

[0147]
[Table 6]

Example 3
Using the deposited film forming apparatus shown in FIG. 3, a positively charged electrophotographic photoreceptor was produced on a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm under the conditions shown in Table 7.
[0148]
First, a surface layer containing carbon atoms and silicon atoms is deposited on a silicon wafer substrate and a Corning 7059 glass substrate, and the carbon atom content (C / (Si + C)) is changed by changing the flow rates of silane gas and methane gas. The region in which the optical band gap increases and the region in which the optical band gap decreases with increasing is investigated. The first surface layer is formed in a region where the optical band gap increases as the carbon atom content (C / (Si + C)) increases, and the second surface layer has a carbon atom content ( It is formed in a region where the optical band gap decreases as C / (Si + C)) increases, and the difference between the optical band gaps of the first surface layer and the second surface layer is 0.1 eV. It was combined as follows.
[0149]
In Example 3, the content of the Group 15 element in the periodic table with respect to the silicon atoms contained in the first surface layer is 50 atom ppm, 100 atom ppm, 5000 atom ppm, 10000 atom ppm, 30000 atom ppm, It was changed to 35000 atoms ppm. In this example, phosphine gas was used as a gas species containing the Group 15 element of the periodic table.
[0150]
(Comparative Example 4)
As in Example 3, the lower charge injection blocking layer and the photoconductive layer were sequentially laminated on the aluminum cylinder under the conditions shown in Table 8 using the deposited film forming apparatus shown in FIG. Instead of being divided into two layers as in the examples, a single layer was laminated in the same manner as in Comparative Example 3 to produce a positively charged electrophotographic photosensitive member.
[0151]
In Comparative Example 4, high-frequency power was introduced with an oscillation frequency introduced to the high-frequency electrode only of 105 MHz.
[0152]
The characteristics of the positively charged electrophotographic photosensitive member thus produced were evaluated as follows.
[0153]
<Chargeability>
The electrophotographic photosensitive member is installed in an electrophotographic apparatus (a Canon GP405 modified for positive charge evaluation), the process speed is 200 mm / sec, the pre-exposure (LED with a wavelength of 660 nm), the light quantity of 4 lx · s, the current value of the charger Measure the surface potential of the photoconductor without image exposure (semiconductor laser with a wavelength of 655 nm) by the potential sensor of the surface potentiometer (Model 344 of TREK) set at the position of the developing unit of the electrophotographic apparatus under the condition of 1000 μA. It was designated as charging ability.
[0154]
<Strong exposure image flow>
For the evaluation of strong exposure image flow, a test chart in which a black portion and a white portion shown in FIG. 5 are arranged with a constant width a by an electrophotographic apparatus (a Canon GP405 modified for positive charge evaluation) is prepared. When the line width a was narrowed, the reproduction was performed on the copy image, and the minimum line width a that could be resolved was used. That is, when the line width a is narrowed, if the line width a becomes equal to or smaller than a certain line width a, minute blur due to the image flow of the outline of the adjacent black portion on the image overlaps, effectively making the resolution impossible. The line width a at that time was used as an index representing the degree of image flow.
[0155]
For each item, a relative comparison was performed with the evaluation value of the positively charged electrophotographic photosensitive member of Comparative Example 4 set to 100.
[0156]
Table 9 shows the results of Example 3 and Comparative Example 4. As is apparent from Table 9, the electrophotographic photosensitive member having the first surface layer in which the content of Group 15 element in the periodic table with respect to silicon atoms is 100 atoms to 30,000 ppm is improved in chargeability and image flow. In particular, an effect was obtained with respect to suppression.
[0157]
[Table 7]

[0158]
[Table 8]

[0159]
[Table 9]

[0160]
【The invention's effect】
According to the present invention, the charge quality, the improvement of sensitivity, and the reduction of characteristic unevenness are compatible at a high level, and the image quality is dramatically improved by reducing the strong exposure image flow, fusing and minute cracks generated on the surface of the photoreceptor. An improved electrophotographic photoreceptor composed of a non-single crystal material based on silicon atoms can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram for explaining an example of a suitable layer configuration of an electrophotographic photosensitive member of the present invention.
FIG. 2 is a graph showing the relationship between the carbon content in the surface layer and the optical band gap in the present invention.
FIG. 3 is a schematic view of a deposited film forming apparatus applicable to the present invention.
FIG. 4 is a schematic view of a deposited film forming apparatus applicable to the present invention.
FIG. 5 is a schematic diagram for explaining an example of a test chart.
[Explanation of symbols]
100 electrophotographic photoreceptor
101 Conductive substrate
102 Photoreceptive layer
103 Photoconductive layer
104 First surface layer
105 Second surface layer
106 Lower charge injection blocking layer
3100 Deposition equipment
3110 Center
3111, 4111 reaction vessel
3112, 4112 Exhaust pipe
3113, 4113 Cylindrical substrate
3114, 4114 High frequency electrode
3115, 4115 Matching box
3116, 3117 High frequency power supply
3118, 4118 Source gas introduction pipe
3119 Shield
3120, 4120 heating element
3121 Rotation axis
3122 Reduction gear
3123 motor
3124 Power distribution board

Claims (15)

A conductive substrate is placed in an evacuable reaction vessel, plasma is generated by the high frequency power supplied to the high frequency electrode , carbon atoms and group 13 of the periodic table are formed on the photoconductive layer provided on the conductive substrate. A first surface layer composed of a non-single crystal film based on silicon atoms containing an element or a group 15 element and a second surface layer composed of a non-single crystal film based on silicon atoms containing carbon atoms In the manufacturing method of the electrophotographic photoreceptor to be sequentially laminated,
The first surface layer is formed in a region satisfying the relationship in which the optical band gap increases as the number of carbon atoms contained in the layer increases, and optical increases as the number of carbon atoms contained in the layer increases. And forming the second surface layer in a region satisfying a relation in which the effective band gap decreases. 2. The method for producing an electrophotographic photosensitive member according to claim 1 , wherein a difference in optical band gap between the first surface layer and the second surface layer is 0.3 eV or less. 3. The method of manufacturing an electrophotographic photosensitive member according to claim 2, wherein a surface layer having the same optical band gap between the first surface layer and the second surface layer is formed. Boron atom in the case of periodic table Group 13 element contained in the first surface layer, in the case of Group 15 element according to any one of claims 1 to 3, characterized in that the phosphorus atom A method for producing an electrophotographic photoreceptor. 5. The electrophotography according to claim 1 , wherein in the first surface layer, a content of a Group 13 element in the periodic table with respect to silicon atoms is 100 atom ppm or more and 30000 atom ppm or less. A method for producing a photoreceptor. 5. The electrophotography according to claim 1 , wherein in the first surface layer, the content of a Group 15 element in the periodic table with respect to silicon atoms is 100 atom ppm or more and 30000 atom ppm or less. A method for producing a photoreceptor. 7. The method for producing an electrophotographic photosensitive member according to claim 1 , wherein the high frequency power supplied to the high frequency electrode has an oscillation frequency of 30 MHz to 250 MHz. The high-frequency power includes at least two high-frequency powers having a frequency of 30 MHz to 250 MHz, and has the highest power value and the next highest power value among the power values of these high-frequency powers in the frequency range. When the power value of the high frequency power having the higher frequency is P1 and the power value of the high frequency power having the lower frequency is P2, the power values P1 and P2 are 0.1 ≦ P2 / (P1 + P2) ≦ The method for producing an electrophotographic photosensitive member according to claim 7, wherein the condition of 0.9 is satisfied. A conductive substrate, a photoconductive layer, and the carbon atom, a Group 13 element or Group 15 element of the periodic table, a first surface layer of non-single-crystal film as a matrix of silicon atoms including, An electrophotographic photoreceptor having a second surface layer provided on the first surface layer and comprising a non-single-crystal film based on silicon atoms containing carbon atoms,
The first surface layer is formed in a region satisfying a relationship in which an optical band gap increases with an increase in carbon atoms contained in the layer, and the second surface layer is contained in the layer. An electrophotographic photoreceptor characterized in that it is formed in a region satisfying a relationship in which the optical band gap decreases as the number of carbon atoms increases. The electrophotographic photosensitive member according to claim 9 , wherein a difference in optical band gap between the first surface layer and the second surface layer is 0.3 eV or less. The electrophotographic photosensitive member according to claim 10, wherein optical band gaps of the first surface layer and the second surface layer have the same value . Boron atom in the case of Group 13 elements of the periodic table contained in the first surface layer, in the case of Group 15 element of any one of claims 9 to 11, characterized in that the phosphorus atom Electrophotographic photoreceptor. The electrophotography according to any one of claims 9 to 12 , wherein in the first surface layer, the content of a Group 13 element in the periodic table with respect to silicon atoms is 100 atom ppm or more and 30000 atom ppm or less. Photoconductor. In the first surface layer, the electrophotographic of any of claims 9-12 the content of periodic table Group 15 element based on silicon atoms is equal to or less than 30000 atomic ppm to 100 atomic ppm Photoconductor. The electrophotographic photosensitive member according to any one of claims 9 to 13 , wherein the first surface layer contains a Group 13 element of the periodic table and is used as a negatively charged electrophotographic photosensitive member.

Images