JP4346793B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member.
[0002]
[Prior art]
  The electrophotographic photosensitive member is repeatedly applied with means such as charging, exposure, development, transfer, cleaning, and static elimination. The electrostatic latent image formed by charging and exposure becomes a toner image by a fine particle developer called toner.
[0003]
  In addition, since the electrophotographic photosensitive member is directly subjected to the electrical and mechanical external forces as described above, durability thereof is required. Specifically, durability against surface abrasion and scratches due to rubbing, deterioration of the surface layer due to adhesion of active substances such as ozone and NOx generated during charging is required.
[0004]
  In order to satisfy the above-described requirements for the electrophotographic photoreceptor, attempts have been made to provide various protective layers. For example, JP-A-57-30846 discloses a protective layer in which resistance can be controlled by adding a metal oxide as a conductive powder to a resin.
[0005]
  Dispersing the conductive particles in the protective layer of the electrophotographic photosensitive member is to control the electrical resistance of the protective layer itself and to prevent an increase in the residual potential in the electrophotographic photosensitive member due to repeated electrophotographic processes. On the other hand, the appropriate volume resistivity of the protective layer for the electrophotographic photoreceptor is 10¹⁰-10¹⁵It is known to be Ω · cm. In general, the volume resistance of the protective layerrateAs a method for controlling the above, a method of adding and dispersing conductive particles is known.
[0006]
  Volume resistance of protective layerrateIs substantially determined by the mass ratio between the conductive particles (P) and the binder resin (B), that is, the P / B ratio. The greater the amount of conductive particles (P), the greater the volume resistancerateThe residual potential is lower in the electrophotographic photosensitive member, but the volume resistance is lower.rateIf it becomes too low, it will be easy to cause image flow. Conversely, if there are too few conductive particles, volume resistancerateThe residual potential tends to be high in an electrophotographic photosensitive member. On the other hand, considering the film strength of the protective layer, the smaller the conductive particles,binderThe greater the amount of resin, the harder and stronger the film will be and the less the amount of shaving due to durability.
[0007]
  In general, when conductive particles are dispersed in the protective layer, the particle diameter of the particles is smaller than the wavelength of the incident light, that is, 0.3 μm or less in order to prevent scattering of incident light by the dispersed particles. Is preferred. However, the conductive particles usually tend to aggregate in the resin solution, and are difficult to uniformly disperse. Even if dispersed once, secondary aggregation and precipitation are likely to occur. It was very difficult to produce the membrane stably. Furthermore, it is preferable to disperse ultrafine particles having a small particle size (primary particle size of 0.1 μm or less) from the viewpoint of improving transparency and conductivity uniformity. The dispersibility and dispersion stability of such ultrafine particles are further improved. There was a tendency to get worse.
[0008]
  In order to compensate for the above drawbacks, for example, JP-A-1-306857 discloses a fluorine-containing silane coupling agent, a titanate coupling agent or C₇F₁₅A protective layer to which a compound such as NCO is added is disclosed in JP-A-62-295066.binderJP-A-2-50167 discloses a protective layer in which metal fine powder or metal oxide fine powder having improved dispersibility and moisture resistance by water-repellent treatment is dispersed in a resin.binderA protective layer is disclosed in which a titanate coupling agent, a fluorine-containing silane coupling agent and a metal oxide fine powder surface-treated with acetoalkoxyaluminum diisopropylate are dispersed in a resin.
[0009]
  However, even in these protective layers, the durability against abrasion and scratches due to rubbing is not sufficient, and there has not yet been obtained a satisfactory electrophotographic characteristic as a protective layer that meets the recent high image quality. is there.
[0010]
  On the other hand, also in the curable protective layer containing a charge transport material, in order to reduce the residual potential, it is necessary to increase the mass ratio of the charge transport material (D) and the binder resin (B), that is, the D / B ratio to some extent. There is. However, when the D / B ratio is increased, there are problems that the film hardness becomes weak and the amount of shaving increases. The resin used for the protective layer is curedTypeWhen it is resin, it hardens in the worst caseTypeIn some cases, the curing of the resin was inhibited. Even in the case of a curable protective layer containing a charge transport material, no curable protective layer has yet been obtained that exhibits sufficient characteristics to satisfy both residual potential and durability.
[0011]
[Problems to be solved by the invention]
  An object of the present invention is to have a surface layer having excellent durability against wear, to maintain high quality image quality, no increase in residual potential in a low humidity environment, and almost no negative ghosting. Another object of the present invention is to provide an electrophotographic photosensitive member capable of obtaining image blur under high humidity and a high-quality image without flow, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.
[0012]
[Means for Solving the Problems]
  In accordance with the present invention, in an electrophotographic photoreceptor having a conductive support and a photosensitive layer and a protective layer formed on the conductive support,
  The protective layer contains a curable phenol resin as a binder resin, and at least one element of an alkali metal element and an alkaline earth metal element,
The protective layer is a layer formed using a protective layer preparation solution to which a solution obtained by dissolving the salt of the element in water is added.Ru
An electrophotographic photosensitive member is provided.
[0013]
  According to the present invention, the electrophotographic photoreceptorAnd charging the electrophotographic photosensitive memberCharging means,The electrostatic latent image formed on the electrophotographic photosensitive member is developed with toner to form a toner image.Development means,as well asAnd removing the transfer residual toner on the electrophotographic photosensitive member.At least one means selected from the group consisting of cleaning meansWhenThe process cartridge is characterized in that it is integrally supported and is detachable from the main body of the electrophotographic apparatus.
[0014]
  Furthermore, according to the present invention, the electrophotographic photoreceptor described above,Charging the electrophotographic photoreceptorCharging means,An electrostatic latent image is formed on the electrophotographic photosensitive member by irradiating the charged electrophotographic photosensitive member with exposure light.Exposure means,The electrostatic latent image formed on the electrophotographic photosensitive member is developed with toner to form a toner image.Developing means, andThe toner image formed on the electrophotographic photosensitive member is transferred onto a transfer material.An electrophotographic apparatus having a transfer unit is provided.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described in detail.
[0016]
  In the present invention, the alkali metal element used in the protective layer is preferably potassium or sodium, and the alkaline earth metal element is preferably calcium or magnesium, but is not limited thereto. Furthermore, as an addition method, these metal hydroxides or salts can be directly added to the preparation liquid, or dissolved in water or the like and added in the form of a solution, but are not limited thereto.
[0017]
  In the protective layer containing conductive particles, the resistance of the protective layer is almost determined by the ratio P / B ratio of the conductive particles (P) and the binder (B), and the volume resistance of the protective layer is determined from residual potential and image blur.rate10¹⁰-10¹⁵As described above, it is required to control to (Ω · cm), but from the viewpoint of film strength, the smaller the P / B ratio is, the harder it is and the less the wear due to repeated use durability. It is preferable to make the P / B ratio smaller and the binder richer within the above resistance range. However, there was a trade-off relationship in which the residual potential increased accordingly.
[0018]
  As a result of various studies, the present inventors have found that the above problem can be solved by adding an alkali metal element or an alkaline earth metal element to the protective layer. In other words, alkali metal elements and alkaline earth metal elements are easily ionized, and even when the P / B ratio is small due to ionic conduction in the protective layer, the volume resistance.rateCan be kept low, and an increase in the residual potential can be suppressed. Furthermore, even when an alkali metal element and an alkaline earth metal element were added, the film strength was hardly affected, and the amount of wear due to repeated use was hardly affected as compared with the case where no alkali metal element or alkaline earth metal element was added. The reason why the amount of wear due to durability does not change is still unclear, but it is probably because alkali metal elements and alkaline earth metal elements in the protective layer film are ionized even with a slight amount of moisture in the air. Is present in an ionic state, is not large enough to affect the film strength, and the concentration is low, so it is considered that the film hardness and the amount of abrasion were not affected.
[0019]
  Meanwhile, charge transportmaterialIn the case of a protective layer containing, of course, charge transportmaterialIt is ideal that sufficient charge transfer occurs only by the charge transport function of the material, the residual potential can be sufficiently lowered, and the film strength is hard and difficult to scrape, but when the binder is particularly curable, the charge transportmaterialWhen a sufficient amount of is added, the film hardness decreases and the amount of chipping increases. Conversely, charge transportmaterialIf the amount is reduced, the residual potential increases. However, the present inventors have added charge transport to this by adding an alkali metal element or alkaline earth metal element.materialIt has been found that a sufficient reduction in the residual potential can be obtained without increasing the amount of addition of the material so much that a sufficient film strength can be obtained and a protective layer having excellent durability can be obtained.
[0020]
  Also, if the amount of the alkali metal element or alkaline earth metal element added is too large, the ionic conductivity increases too much, and the resistance fluctuations become large, resulting in image blurring in a high humidity environment. Since the effect ofThe total content of the elements contained in the protective layer is the protective layerIt is preferable to set it to 0.005 mass% or more and 8 mass% or less with respect to the total mass. More preferably, it is 0.01 mass% or more and 5 mass% or less.
[0021]
  Examples of the conductive particles used for the protective layer include metals, metal oxides, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. . These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.
[0022]
  The average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer. Moreover, in this invention, it is especially preferable to use a metal oxide from the point of transparency among the electroconductive particle mentioned above.
[0023]
  Examples of the lubricating particles used in the present invention include fluorine atom-containing resin particles, silicon particles, and silicone particles. In the present invention, fluorine atom-containing resin particles are particularly preferable. Examples of fluorine atom-containing resin particles include ethylene tetrafluoride, ethylene trifluoride chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and copolymers thereof. Among them, it is preferable to select one or more kinds as appropriate, and particularly preferred are tetrafluoroethylene resin and vinylidene fluoride resin. The molecular weight of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited.
[0024]
  This fluorine atom-containing resinparticleIn order to prevent the particles from aggregating in the resin solution, a fluorine atom-containing compound is added at the time of dispersion, or when conductive particles are contained, a fluorine atom-containing compound is added at the time of dispersion, or conductive particles It is preferable to treat the surface with a fluorine atom-containing compound. Dispersibility and dispersion stability of conductive particles and fluorine atom-containing resin particles in the resin solution compared to the case without fluorine atom-containing compounds by adding fluorine atom-containing compounds or surface treatment of conductive particles Has improved dramatically. Further, by dispersing the fluorine atom-containing resin particles in the liquid in which the fluorine atom-containing compound is added or the surface-treated conductive particles are dispersed, there is no formation of secondary particles of dispersed particles over time. However, a very stable coating solution with good dispersibility can be obtained.
[0025]
  Examples of the fluorine atom-containing compound in the present invention include a fluorine-containing silane coupling agent, a fluorine-modified silicone oil, and a fluorine-based surfactant. Although the example of a preferable compound is given to Table 1-Table 3, this invention is not limited to these compounds.
[0026]
[Table 1]
[0027]
[Table 2]
[0028]
[Table 3]
[0029]
  As a surface treatment method for the conductive particles, the conductive particles and the surface treatment agent are mixed and dispersed in an appropriate solvent, and the surface treatment agent is adhered to the surface of the conductive particles. As a dispersion method, a normal dispersion means such as a ball mill or a sand mill can be used. Next, the solvent may be removed from the dispersion and fixed to the surface of the conductive particles. Moreover, you may heat-process further after this as needed. Further, a catalyst for promoting the reaction can be added to the treatment liquid. Furthermore, if necessary, the conductive particles after the surface treatment can be further pulverized.
[0030]
  The ratio of the fluorine atom-containing compound to the conductive particles is also affected by the particle size of the particles, but is preferably 1 to 65% by mass, particularly 1 to 50% by mass, based on the total mass of the surface-treated conductive particles. Is preferred.
[0031]
  As described above, by dispersing the conductive particles after adding the fluorine atom-containing compound, or by using the conductive particles surface-treated with the fluorine atom-containing compound, the dispersion of the fluorine atom-containing resin particles is stabilized, A protective layer excellent in slipperiness and releasability can be formed.
[0032]
  For the protective layer used in the present inventionbinderAs the resin, a curable resin is more preferable because it has a high surface hardness and excellent wear resistance. Examples of the curable resin include, but are not limited to, an acrylic resin, a urethane resin, an epoxy resin, a silicone resin, and a phenol resin. In the present invention, thermosetting typeofA phenol resin is preferable, and a resol type phenol resin is more preferable.
[0033]
  Said resin is resin containing the monomer or oligomer which hardens | cures with a heat | fever or light. A monomer or oligomer that is cured by heat or light has, for example, a functional group that undergoes a polymerization reaction at the end of the molecule due to heat or light energy, and among these, the number of repeating molecular structural units is about 2 to 20 A large molecule is an oligomer, and a single molecule is a monomer. Examples of the functional group causing the polymerization reaction include those having a carbon-carbon double bond such as acryloyl group, methacryloyl group, vinyl group and acetophenone group, silanol group, and further ring-opening polymerization such as cyclic ether group, and the like. Examples thereof include those in which two or more kinds of molecules react to cause polymerization, such as phenol + formaldehyde.
[0034]
  Further, in the present invention, in order to obtain a more environmentally stable protective layer, a siloxane compound represented by the following general formula (1) is added at the time of dispersing the conductive particles, or a conductive material which has been previously surface-treated. By mixing the conductive particles, it was possible to obtain a protective layer more excellent in environmental stability.
[0035]
[Chemical formula 2]
[0036]
  formula(1)A is a hydrogen atom or a methyl group, and the ratio of hydrogen atoms in all of A is in the range of 0.1 to 50%And, N is an integer of 0 or more.
[0037]
  A coating liquid in which the siloxane compound is added and dispersed, or a conductive material that has been surface-treated.GrainThe child was dissolved in a solventbinderBy dispersing in the resin, there is no formation of secondary particles of dispersed particles, and a coating solution with good dispersibility that is stable over time can be obtained. Further, the protective layer formed from this coating solution has transparency. A film that was high and excellent in environmental resistance was obtained. Furthermore, the resin used for the protective layer is curable.ofIn the case of “hard but brittle resin” such as phenolic resin, although it depends on the type of phenolic resin, streaky irregularities and cells may be formed as the protective layer becomes thicker. Addition of the above-mentioned siloxane compound, or conductive surface treatment of thisGrainBy using a child, it is possible to suppress the formation of streaky irregularities and cells, and there is an unexpected effect such as a leveling agent.
[0038]
  The molecular weight of the siloxane compound represented by the general formula (1) is not particularly limited. However, in the case of surface treatment, it is better that the viscosity is not too high because of its ease, and the weight average molecular weight is several hundreds. About tens of thousands are appropriate.
[0039]
  There are two surface treatment methods, wet and dry. In the wet treatment, the conductive particles and the siloxane compound represented by the general formula (1) are dispersed in a solvent, and the siloxane compound is adhered to the surface of the fine particles. As a dispersing means, a general dispersing means such as a ball mill or a sand mill can be used. Next, this dispersion is made conductive.GrainAdhere to the child surface. In this heat treatment, Si—H bonds in the siloxane are oxidized by hydrogen atoms by oxygen in the air during the heat treatment process, and new siloxane bonds are formed. As a result, the siloxane develops into a three-dimensional structure and becomes conductive.GrainThe child surface is wrapped with this network structure. Thus, the surface treatment makes the siloxane compound conductive.GrainComplete by adhering to the child surface, but after treatment if necessaryGrain ofThe child may be crushed.
[0040]
  In the dry treatment, the siloxane compound and the conductive material are used without using a solvent.GrainThe siloxane compound is mixed by kneading and mixingConductivityAdhere to the particle surface. Thereafter, heat treatment and pulverization are performed in the same manner as the wet treatment to complete the surface treatment.
[0041]
  Conductivity in the present inventionGrainThe ratio of the siloxane compound to the child isConductivityAlthough it depends on the particle size of the particles, the ratio of methyl groups to hydrogen atoms in the siloxane, etc., 1 to 50% by mass is preferable, and 3 to 40% by mass is particularly preferable. In addition, charge transport to a protective layer solution containing conductive particlesmaterialOf course, no conductive particles, charge transportmaterialA protective layer containing
[0042]
  Charge transportmaterialIn the case of a protective layer containingmaterialExamples of the hydrazone compound, the styryl compound, the oxazole compound, the thiazole compound, the triarylmethane compound, and the polyarylalkane compound are not limited thereto. The solvent of the protective layer solution is preferably a solvent that does not adversely affect the charge transporting layer that is in contact with it. Therefore, the solvent includes alcohols such as methanol, ethanol and 2-propanol, ketones such as acetone and MEK, esters such as methyl acetate and ethyl acetate, ethers such as THF and dioxane, and aromatics such as toluene and xylene. Group hydrocarbons or halogenated hydrocarbons such as chlorobenzene and dichloromethane can be used. Among these, the best solvents in the dip coating method with good productivity are alcohols such as methanol, ethanol and 2-propanol.
[0043]
  When the protective layer in the present invention is a thermosetting type, it is usually cured in a hot air drying furnace after the protective layer is applied on the photosensitive layer. The curing temperature at this time is preferably from 100 ° C to 300 ° C, particularly preferably from 120 ° C to 200 ° C. Further, the thickness of the protective layer is preferably 0.5 μm to 10 μm, and particularly preferably 1 μm to 7 μm.
[0044]
  In the present invention, an additive such as an antioxidant may be added to the protective layer.
[0045]
  Next, the photosensitive layer will be described.
[0046]
  The electrophotographic photoreceptor of the present invention has a laminated structure. In the electrophotographic photosensitive member of FIG. 1A, a charge generation layer 3 and a charge transport layer 2 are provided in this order on a conductive support 4, and a protective layer 1 is further provided on the outermost surface. Further, as shown in FIGS. 1B and 1C, a binder layer 5 and an undercoat layer 6 for preventing interference fringes may be provided between the conductive support and the charge generation layer. Good.
[0047]
  As the conductive support 4, the support itself can be conductive, for example, aluminum, aluminum alloy, stainless steel, or the like. In addition, aluminum, aluminum alloy, indium oxide-tin oxide alloy, or the like can be used by vacuum deposition. The conductive support or plastic having a film-formed layer, conductiveGrainA support obtained by impregnating a plastic (for example, carbon black, tin oxide, titanium oxide, and silver particles) with a suitable binder in plastic or paper, a plastic having a conductive binder, or the like can be used.
[0048]
  In addition, a binder layer (adhesive layer) having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer.
[0049]
  The binder layer is used to improve the adhesion of the photosensitive layer, improve the coating property, protect the support, cover defects on the support, improve the charge injection from the support, and protect against electrical breakdown of the photosensitive layer. Formed. The binder layer can be formed of casein, polyvinyl alcohol, ethyl cellulose, ethylene-acrylic acid copolymer, polyamide, modified polyamide, polyurethane, gelatin, aluminum oxide, or the like. The thickness of the binding layer is preferably 5 μm or less, and more preferably 0.2 to 3 μm.
[0050]
  Charge generation used in the present inventionmaterialAs phthalocyanine pigments, azo pigments, indico pigments, polycyclic quinone pigments, perylene pigments, quinacridone pigments, azurenium salt pigments, pyrylium dyes, thiopyrylium dyes, squarylium dyes, cyanine dyes, xanthene dyes, quinoneimine dyes, triphenylmethane dyes, Examples include styryl dyes, selenium, selenium-tellurium, amorphous silicon, cadmium sulfide, and zinc oxide.
[0051]
  The solvent used in the charge generation layer paint is the resin used and the charge generation.materialThe organic solvent may be alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, aromatic compounds, or the like.
[0052]
  The charge generation layer 3 includes the charge generation material in an amount of 0.3 to 4 times the mass ratio.binderAlong with the resin and the solvent, they are well dispersed by a method such as homogenizer, ultrasonic wave, ball mill, sand mill, attritor or roll mill, and are formed by coating and drying. The thickness is preferably 5 μm or less, and particularly preferably in the range of 0.01 to 1 μm.
[0053]
  As the charge transport material, a hydrazone compound, a pyrazoline compound, a styryl compound, an oxazole compound, a thiazole compound, a triarylmethane compound, a polyarylalkane compound, or the like can be used, but is not limited thereto. It is not a thing.
[0054]
  The charge transport layer 2 is generally composed of the charge transport material described above.binderThe resin is dissolved in a solvent and applied to form. Charge transport materials andbinderThe mixing ratio with the resin (mass ratio) is about 2: 1 to 1: 2. Solvents include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene, or chlorinated hydrocarbons such as chlorobenzene, chloroform and carbon tetrachloride. It is done. When applying this solution, for example, a coating method such as a dip coating method, a spray coating method and a spinner coating method can be used, and drying is preferably 10 ° C to 200 ° C, more preferably 20 ° C to 150 ° C. The temperature is in the range of 5 minutes to 5 hours, and more preferably 10 minutes to 2 hours.
[0055]
  Used to form the charge transport layer 2binderThe resin is preferably a resin selected from acrylic resin, styrene resin, polyester, polycarbonate resin, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane resin, alkyd resin, and unsaturated resin. Particularly preferred resins include polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer, polycarbonate resin and diallyl phthalate resin. The thickness of the charge transport layer is preferably 5 to 40 μm, and particularly preferably 10 to 30 μm.
[0056]
  In addition, the charge generation layer or the charge transport layer can contain various additives such as an antioxidant, an ultraviolet absorber, and a lubricant.
[0057]
  Further, the protective layer is applied and cured on the photosensitive layer to form a film.
[0058]
  Conversely, the protective layer may be applied and cured after applying the charge generation layer on the charge transport layer. In addition, charge generationmaterialAnd charge transportmaterialThe protective layer may be applied and cured on a photosensitive layer containing
[0059]
  FIG. 2 shows a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.
[0060]
  In the figure, reference numeral 11 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated about a shaft 12 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the electrophotographic photosensitive member 11 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by the primary charging unit 13, and then from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. The exposure light 14 that is enhanced and modulated corresponding to the time-series electric digital image signal of the target image information to be output is received. In this way, electrostatic latent images corresponding to target image information are sequentially formed on the peripheral surface of the electrophotographic photosensitive member 11.
[0061]
  The formed electrostatic latent image is then developed with toner by the developing means 15 and taken out from a paper feeding unit (not shown) between the electrophotographic photosensitive member 11 and the transfer means 16 in synchronization with the rotation of the electrophotographic photosensitive member 11. The toner image formed and supported on the surface of the electrophotographic photosensitive member 11 is sequentially transferred by the transfer means 16 to the transfer material 17 thus fed.
[0062]
  The transfer material 17 that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member, introduced into the image fixing means 18, and subjected to image fixing to be printed out as an image formed product (print, copy). .
[0063]
  After the image is transferred, the surface of the electrophotographic photosensitive member 11 is cleaned by removing the transfer residual toner by the cleaning unit 19, and is further subjected to charge removal processing by the pre-exposure light 20 from the pre-exposure unit (not shown). Used repeatedly for image formation. When the primary charging unit 13 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.
[0064]
  In the present invention, a plurality of constituent elements such as the electrophotographic photosensitive member 11, the primary charging unit 13, the developing unit 15, and the cleaning unit 19 described above are housed in a container 21 and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 13, the developing unit 15, and the cleaning unit 19 is integrally supported together with the electrophotographic photosensitive member 11 to form a cartridge, and is attached to and detached from the apparatus main body using a guide unit 22 such as a rail of the apparatus main body. A flexible process cartridge can be obtained.
[0065]
  Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 14 is a reflected light or transmitted light from a document, or a signal is read by a document by a sensor, and a laser beam scanning performed according to this signal is performed. Light emitted by driving the LED array, driving the liquid crystal shutter array, or the like.
[0066]
  The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, FAX, liquid crystal printers, and laser plate making. .
[0067]
【Example】
  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, "part" in an Example represents a mass part.
[0068]
  (referenceExamples 1-6)
  Using a 30 mm × 260.5 mm aluminum cylinder as a support, a 5 mass% methanol solution of polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) was applied thereon by a dipping method, and the film thickness was 0.5 μm. An undercoat layer was provided.
[0069]
  Next, in the following structural formula (2)Indicated, CuKα has strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° with Bragg angle 2θ ± 0.2 ° in characteristic X-ray diffraction4 parts of oxytitanium phthalocyanine pigment,
[0070]
[Chemical 3]
[0071]
2 parts of polyvinyl butyral resin BX-1 (manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of cyclohexanone were dispersed for about 4 hours by a sand mill apparatus using φ1 mm glass beads. This solution was applied onto the undercoat layer and dried with hot air at 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.
[0072]
  Next, the following structural formula (3)Indicated by10 parts of a compound,
[0073]
[Formula 4]
[0074]
as well as,10 parts of bisphenol Z-type polycarbonate (trade name: Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 100 parts of monochlorobenzene. This solution was applied onto the charge generation layer and dried with hot air at 105 ° C. over 1 hour to form a charge transport layer having a thickness of 20 μm.
[0075]
  Next, as a protective layer, the following structural formula (4)Compound shown
[0076]
[Chemical formula 5]
[0077]
20 parts of antimony-doped tin oxide ultrafine particles surface-treated with (treatment amount 7%),SaidGeneral30 parts of antimony-doped tin oxide fine particles (20%) surface-treated with methyl hydrogen silicone oil represented by formula (1) (trade name: KF99, manufactured by Shin-Etsu Silicone Co., Ltd.),as well as,Disperse 150 parts of ethanol in a sand mill using 1 mmφ glass beads over 66 hours, add 20 parts of polytetrafluoroethylene fine particles (average particle size 0.18 μm), and further disperse for 2 hours. It was. Then, the following structural formula (5)Compound represented by45 parts,
[0078]
[Chemical 6]
[0079]
as well as,As a photopolymerization initiator, 20 parts of 2-methylthioxanthone is dissolved, and further, 0.1 part, 0.15 part, 1.5 parts, 15 parts, 72 parts of an aqueous sodium acetate solution (about 30% by mass) is added to the liquid. Parts and 100 parts of the added solution were designated as protective layer preparations 1 to 6. Using this preparation solution, a film was formed by dip coating on the charge transport layer, and 800 mW / cm with a high-pressure mercury lamp.²Then, photocuring was performed for 60 seconds at a light intensity of 2, followed by hot-air drying at 120 ° C. for 2 hours to form a protective layer having a thickness of 3 μm. Moreover, the dispersibility of the protective layer preparation liquid was good, and the film surface was a uniform surface without unevenness.
[0080]
  For the evaluation of the test, Canon Inc. LBP-NX (roller contact charging, AC / DC application) was used. As evaluation, initial image evaluation was performed in a 23 ° C./5% RH environment. Furthermore, after endurance of 10,000 sheets in a 23 ° C./80% RH environment, the scraping amount and image evaluation were performed. The residual potential was measured at a position 0.2 seconds after strong exposure using a drum tester manufactured by Gentec Co., Ltd. in an environment of 23 ° C./5% RH.
[0081]
  Further, qualitative analysis of alkali metal elements and alkaline earth metal elements in the protective layer film is measured with a fluorescent X-ray apparatus RIX-3800 (manufactured by Rigaku Corporation) to identify the metal in the protective layer. It was. Next, quantitative analysis was performed using an ICP emission spectroscopic analyzer SPS1700 (manufactured by Seiko Instruments Inc.). First, the protective layer is scraped off and a fixed amount (20 mg) is measured. Next, this was pretreated in a sealed container with a microwave high power sample pretreatment apparatus ETHOS 1600 (Milestone General Co., Ltd.) at an internal temperature of 220 ° C./1 hour, and this was made into aqua regia (about 0.2 g). The sample was dissolved. The amount of aqua regia added at this time is measured accurately so that the concentration can be understood. This sample was analyzed with the ICP analyzer at a high frequency output of 1 KW, and quantitative analysis of alkali metal elements and alkaline earth metal elements was performed. The results are shown in Table 4.
[0082]
  (referenceExamples 7-12)
  referenceIn Examples 1 to 6, instead of sodium acetate, a solution obtained by adding 0.05 part, 0.1 part, 1 part, 10 parts, 48 parts and 80 parts of 30% by weight calcium carbonate aqueous solution was used as protective layer preparation liquid 7 Except for producing a protective layer of ~ 12,referencePerformed exactly as in Examples 1-6. The results are shown in Table 4.
[0083]
  (Comparative Example 1)
  referenceIn Example 1, except that the aqueous sodium acetate solution was not added,referencePerformed exactly as in Example 1. The results are shown in Table 4.
[0084]
  (Comparative Example 2)
  referenceIn Example 1, except that the aqueous solution of sodium acetate was not added and the residual potential was 50 V in an environment of 23 ° C./5% RH, the compound represented by the structural formula (5) was replaced with 15 parts. ,referencePerformed exactly as in Example 1. The results are shown in Table 4.
[0085]
  (Examples 13 to 18)
  referenceIn Examples 1 to 6, no conductive particles were added to the protective layer, and 150 parts of ethanol, 10 parts of polytetrafluoroethylene particles and 0.4 parts of the compound represented by the structural formula (4) were dispersed in a sand mill for 2 hours. 90 parts of a resol-type phenol resin BKS-316 (produced by Showa Polymer Co., Ltd., containing an amine compound other than ammonia) as a resin component was added to the liquid, and an aqueous sodium acetate solution (30% by mass) was added to the solution in an amount of 0.001. 1 part, 0.13 part, 1.5 parts, 15 parts, 62 parts and 100 parts added were used as protective layer preparation liquid 13-18, and a protective layer having a thickness of 1 μm was cured and formed at 145 ° C./1 hour. IsreferencePerformed exactly as in Examples 1-6. The results are shown in Table 4.
[0086]
  (Comparative Example 3)
  In Example 13, it carried out like Example 13 except not having added sodium acetate aqueous solution. The results are shown in Table 4.
[0087]
  (referenceExamples 19-24)
  referenceIn Examples 1 to 6, without adding conductive particles to the protective layer, 150 parts of ethanol, 25 parts of polytetrafluoroethylene particles and 1 part of the compound represented by the structural formula (4) were dispersed in a sand mill for 2 hours. 45 parts of the compound represented by the structural formula (5) and 30 parts of the compound represented by the following structural formula (6).
[0088]
[Chemical 7]
[0089]
And 20 parts of 2-methylthioxanthone is dissolved as a photopolymerization initiator, and 0.1 part, 0.13 part, 1.5 part, 15 part of an aqueous sodium acetate solution (about 30% by mass) is further added to the liquid. Parts, 62 parts, and 100 parts of the liquid were designated as protective layer preparation liquids 19 to 24.
[0090]
  Using this preparation solution, a film was formed by dip coating on the charge transport layer, and 800 mW / cm with a high-pressure mercury lamp.²Except that the film was photocured for 60 seconds and then dried with hot air at 120 ° C. for 2 hours to form a protective layer with a thickness of 3 μm.referencePerformed exactly as in Examples 1-6. The results are shown in Table 4.
[0091]
  (Comparative Example 4)
  referenceIn Example 19, except that the aqueous sodium acetate solution was not added,referencePerformed exactly as in Example 19. The results are shown in Table 4.
[0092]
[Table 4]
[0093]
  As shown in Table 4, in the electrophotographic photosensitive member having a conductive support and a photosensitive layer and a protective layer formed on the conductive support, the protective layer is a curable phenol resin as a binder resin. , Containing at least one element of an alkali metal element and an alkaline earth metal element,The protective layer is a layer formed using a protective layer preparation solution to which a solution obtained by dissolving the salt of the element in water is added.By using an electrophotographic photosensitive member, it has excellent durability against wear, has a low residual potential in a low-humidity environment, hardly generates negative ghosts, and also has an image flow under high humidity. In addition, high durability, high stability and high quality images could be obtained.
[0094]
【The invention's effect】
  As described above, according to the present invention, in an electrophotographic photosensitive member having a conductive support and a photosensitive layer and a protective layer formed on the conductive support, the protective layer is cured as a binder resin. Type phenolic resin and at least one element of alkali metal element and alkaline earth metal element,The protective layer is a layer formed using a protective layer preparation solution to which a solution obtained by dissolving the salt of the element in water is added.By using the electrophotographic photosensitive member, it has excellent durability against wear, has a low residual potential in a low-humidity environment, has almost no negative ghost, and further has no image flow under high humidity. A durable, highly stable and high-quality image could be obtained.
[0095]
  In addition, the process cartridge having the electrophotographic photosensitive member and the electrophotographic apparatus were also able to achieve remarkable effects.
[Brief description of the drawings]
FIG. 1 is a diagram showing a layer structure of an electrophotographic photosensitive member of the present invention.
FIG. 2 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.
[Explanation of symbols]
  1 Protective layer
  2 Charge transport layer
  3 Charge generation layer
  4 Conductive support
  5 binding layers
  6 Underlayer
  11 Electrophotographic photoreceptor
  12 axes
  13 Charging means
  14 Exposure light
  15 Development means
  16 Transfer means
  17 Transfer material
  18 Fixing means
  19 Cleaning means
  20 Pre-exposure light
  21 Process cartridge container
  22 Guide means

Claims (11)

In an electrophotographic photosensitive member having a conductive support and a photosensitive layer and a protective layer formed on the conductive support,
The protective layer contains a curable phenol resin as a binder resin, and at least one element of an alkali metal element and an alkaline earth metal element,
The protective layer, the electrophotographic photosensitive member, wherein a layer der Rukoto formed using a salt of said element protective layer preparations of solutions dissolved in water was added.   The electrophotographic photosensitive member according to claim 1, wherein the element is sodium or calcium. It said salt electrophotographic photosensitive member according to claim 1 or 2 which is sodium acetate or calcium carbonate. The total amount of the element contained in the protective layer, the electrophotographic photosensitive member according to any one of the protective layer according to claim 1-3 total mass or less 0.01 mass% to 5 mass% relative to . The curable phenolic resin, electrophotographic photosensitive member according to any one of claims 1 to 4, which is a resol-type phenolic resin. The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the protective layer contains lubricating particles. The electrophotographic photosensitive member according to claim 6 , wherein the lubricating particles are fluorine atom-containing resin particles. The electrophotographic photosensitive member according to claim 7 , wherein the protective layer contains a fluorine atom-containing compound. The electrophotographic photosensitive member according to claim 8 , wherein the fluorine atom-containing compound is a fluorine-containing silane coupling agent. An electrophotographic photosensitive member according to any one of claims 1 to 9 charging means for charging the electrophotographic photoreceptor, a toner image by developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner And at least one means selected from the group consisting of a developing means for forming the toner and a cleaning means for removing residual toner on the electrophotographic photosensitive member, and is detachably attached to the main body of the electrophotographic apparatus. Process cartridge characterized by. The electrophotographic photosensitive member according to any one of claims 1 to 9 charging means for charging the electrophotographic photoreceptor, charged by irradiating the exposure light with respect to the electrophotographic photosensitive member on the electrophotographic photosensitive member was An exposure unit that forms an electrostatic latent image, a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and an electrostatic latent image formed on the electrophotographic photosensitive member An electrophotographic apparatus comprising transfer means for transferring a toner image onto a transfer material.