JP2003316041A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor free from the peeling of a protective layer caused by endurable service in repetitive use and excellent in wear and abrasion resistance and electrophotographic characteristic, and to provide a process cartridge and an electrophotographic device having the photoreceptor. <P>SOLUTION: In the electrophotographic photoreceptor having a photoreceptive layer and the protective layer on a conductive supporting body, the protective layer incorporates at least either conductive particles or charge transporting material and thermosetting resin, and the protective layer is formed by passing many stages of drying temperature in a drying stage after coating, and initial drying temperature (A°C) is within ±25°C of the boiling point of a solvent used for the coating paint of the protective layer, and initial drying time is 15 s to 15 min, and the total time of multistage drying except the initial drying time is 20 to 120 min. Thus, the electrophotographic photoreceptor, and the process cartridge and the electrophotographic device having the photoreceptor are provided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a process cartridge and an electrophotographic apparatus, and more specifically, an electrophotographic photoreceptor having a highly durable protective layer,
The present invention relates to a process cartridge having the electrophotographic photosensitive member and an electrophotographic apparatus.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors are used for charging, exposing, developing,
Means such as transfer, cleaning and charge removal are repeatedly applied. The electrostatic latent image formed by charging and exposure becomes a toner image by a fine particle developer called toner. Further, this toner image is transferred to a transfer material such as paper by the transfer means, but not all the toner is transferred, and a part thereof remains on the electrophotographic photosensitive member.

When the amount of the residual toner is large, the image on the transfer material is in a so-called "blurred" state in which transfer failure is further caused, and not only the uniformity of the image is lacked but also the fusion of the toner to the electrophotographic photosensitive member and the The problem of filming occurs.
For these problems, it is required to improve the releasability of the surface layer of the electrophotographic photosensitive member.

Further, the electrophotographic photosensitive member is required to have durability against the above-mentioned electric and mechanical external forces, since it is directly applied thereto. Specifically, durability is required against abrasion and scratches on the surface due to rubbing, and deterioration of the surface layer due to adhesion of active substances such as ozone and NOx generated at the time of charging.

Attempts have been made to provide various protective layers in order to meet the above-mentioned demands for electrophotographic photoreceptors. For example, Japanese Patent Application Laid-Open No. 57-30846 proposes a protective layer capable of controlling resistance by adding a metal oxide as a conductive powder to a resin.

Dispersing the conductive particles in the protective layer of the electrophotographic photosensitive member controls the electric resistance of the protective layer itself and prevents an increase in residual potential in the electrophotographic photosensitive member due to repeated electrophotographic processes. Is its main purpose, while the suitable volume resistivity of the protective layer for an electrophotographic photoreceptor is 10 ¹⁰ ~.
It is known to be 10 ¹⁵ Ω · cm. However, in the resistance value in the above range, the electric resistance of the protective layer is easily affected by ion conduction, and therefore the electric resistance tends to largely change due to changes in the environment.
In particular, when the metal oxide is dispersed in the film, the water absorption of the surface of the metal oxide is high, and therefore the resistance of the protective layer is improved in the entire environment and when the electrophotographic process is repeated. It has been very difficult to maintain the above range. Further, many resins themselves have high water absorption, and the resins themselves often cause a reduction in the resistance of the protective layer.

[0007] Particularly under high humidity, the resistance is lowered by leaving it standing, and ozone and NOx generated by charging are generated.
Repeated adhesion of active substances such as the above to the surface causes a decrease in the resistance of the surface of the electrophotographic photosensitive member and a decrease in the releasability of the toner from the surface layer, resulting in image deletion and uneven image uniformity. There were problems such as being sufficient.

In general, when the conductive particle particles are dispersed in the protective layer, the particle diameter of the particle is smaller than the wavelength of the incident light, that is, 0.3 μm, in order to prevent scattering of the incident light by the dispersed particles. The following is preferable. However, since conductive particles usually tend to aggregate in a resin solution, it is difficult to uniformly disperse them, and secondary dispersion or precipitation easily occurs even if they are once dispersed. Therefore, a good dispersion film of fine particles having a particle size of 0.3 μm or less is obtained. It was very difficult to produce a stable product. Further, it is preferable to disperse ultrafine particles having a particularly small particle size (primary particle size of 0.1 μm or less) from the viewpoint of improving transparency and conductivity uniformity, but the dispersibility and dispersion stability of such ultrafine particles are further improved. It tended to get worse.

In order to make up for the above drawbacks, for example, Japanese Patent Laid-Open No.
No. 306857 discloses a fluorine-containing silane coupling agent, a titanate coupling agent or C ₇ F ₁₅ NC.
A protective layer containing a compound such as O is disclosed in JP-A-62-295.
Japanese Patent Laid-Open No. 2-50167 discloses a protective layer in which a fine metal powder or a fine metal oxide powder having improved dispersibility and moisture resistance is dispersed in a binder resin by a water repellent treatment. A protective layer is disclosed in which a titanate coupling agent, a fluorine-containing silane coupling agent, and a fine metal oxide powder surface-treated with acetoalkoxyaluminum diisopropylate are dispersed in a binder resin.

The electrophotographic apparatus includes an electrophotographic photosensitive member, a charging unit for charging the surface of the electrophotographic photosensitive member, and an exposing unit for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging unit. Developing means for developing the electrostatic latent image formed by the exposing means with toner to form a toner image, transfer means for transferring the toner image formed by the developing means onto a recording medium such as paper, and transfer means In general, the toner image transferred to the recording medium is fixed by a fixing unit that fixes the toner image on the recording medium.

As a charging means, a corona charging device (corona discharger) has been widely used. Further, since it has advantages such as low ozone and low power as compared with the corona charging device, a contact type charging device for charging the electrophotographic photosensitive member by bringing a charging member to which a voltage is applied into contact with the electrophotographic photosensitive member is brought into contact. (Contact charging device) is also in practical use.

In the contact charging device, a conductive charging member such as a roller type, a fur brush type, a magnetic brush type or a blade type is brought into contact with the electrophotographic photosensitive member, and this charging member (hereinafter referred to as a contact charging member). A predetermined charging bias is applied to the surface of the electrophotographic photosensitive member to charge it to a predetermined polarity and potential.

As the charging mechanism for contact charging, two types of charging mechanism, a discharge charging mechanism and a direct injection charging mechanism, are mixed.
Each characteristic appears depending on which is dominant.

However, in principle, generation of ozone in the discharge charging mechanism is unavoidable, and in the direct injection charging mechanism,
It is difficult to directly charge with a simple structure using a charging roller or a fur brush, and image fogging (white background is developed in the case of reversal development) and uneven charging occur due to absolute charging failure.

Therefore, the following method has been proposed as a new charging method. A charging device for charging a surface of an electrophotographic photosensitive member by bringing a charging member to which a voltage is applied into contact with the electrophotographic photosensitive member, wherein the charging member is composed of an elastic body,
The surface of the charging member has a speed difference with respect to the surface of the electrophotographic photosensitive member, and at least the conductive particles are carried on the contact surface between the charging member and the electrophotographic photosensitive member. As a result, sufficient contact property can be obtained in direct charging, and uniform charging is possible.

Further, it has means for supplying the conductive particles. As a result, the charging can be stably performed even when the charging device is used for a long period of time.

The resistance value of the conductive particles is 1 × 10 ⁹ Ω.
・ It is below cm. As a result, it becomes possible to perform uniform and stable charging in direct charging.

The diameter of the conductive particles is 10 nm or more and 1
It is smaller than the size of the pixel. This makes it possible to provide an apparatus capable of obtaining a good image that does not interfere with exposure.

The volume resistance of the outermost surface layer of the electrophotographic photosensitive member is 1
× 10 ¹⁴ Ω · cm or less. Further, the volume resistance of the outermost surface layer of the electrophotographic photoreceptor is 1 × 10 ⁹ Ω · cm or more and 1 × 10.
^{It is 14} Ω · cm or less. As a result, sufficient chargeability can be provided even in a device with a high process speed.

A charger disposed around the electrophotographic photosensitive member to contact the electrophotographic photosensitive member and uniformly charge the electrophotographic photosensitive member, and an electrostatic latent image by exposing the electrophotographic photosensitive member. And an exposing device for forming the electrostatic latent image with a developer,
In addition, the above-described electrophotographic image recording apparatus includes a developing device that collects toner remaining on the electrophotographic photosensitive member and a transfer charger that transfers the toner image on the electrophotographic photosensitive member to a recording medium. Use a charging device. As a result, an excellent charging method has been devised that can provide uniform charging even in the toner recycling image forming apparatus.

[0021]

Even in these protective layers, the resistance under high humidity is low, image blurring occurs, and the durability against abrasion and scratches due to rubbing is not sufficient. At present, no protective layer having satisfactory electrophotographic characteristics has been obtained.

However, as described above, the protective layer is required to have a certain degree of hardness and abrasion resistance, and even though it is important to satisfy the characteristics as an electrophotographic photoreceptor, Using thermosetting resin, charge transport material,
When at least one of the conductive particles is contained, it is necessary to dry at a high temperature for the thermosetting reaction. However, providing sufficient heat for forming the photosensitive layer and obtaining the amount of heat for curing already deteriorates the electrophotographic characteristics of the electrophotographic photosensitive member.

Further, if the temperature for drying the protective layer is high at one time, the conductive particles contained in the protective layer will locally have high heat, and the solvent around the conductive particles will be removed. By volatilizing all at once, a minute void is formed between the protective layer resin and the resin, thereby forming a gap, and the conductive particles are peeled off in a continuous printing durability test, resulting in a black spot in the image. In addition, the charge transport material contained in the protective layer is dried at once, so that the surrounding resin for the protective layer is solidified at once, so that the molecular movement of the charge transport material is hindered, and π
The electrons cannot be overlapped well, and the charge transport function is not fully exerted, resulting in a low concentration.

On the contrary, if the drying temperature is low and drying is carried out at once, the curing is not sufficiently carried out and the protective layer cannot be used.

Furthermore, if the drying temperature is lowered and the drying time is too long, the material in the photosensitive layer is given too much heat, and the thermal history may deteriorate the electrophotographic characteristics. is there. Further, if the drying time is too short, the protective layer is not sufficiently cured and the abrasion resistance is not sufficiently satisfied, as in the case where the drying temperature is low.

In other words, in order to produce an electrophotographic photosensitive member which functions as a protective layer and has sufficiently satisfactory electrophotographic characteristics, it is necessary to achieve a delicate balance between the drying time and the drying temperature.

Further, the new charging system is a charging device for charging a surface of an electrophotographic photosensitive member by bringing a charging member to which a voltage is applied into contact with the electrophotographic photosensitive member, wherein the charging member is composed of an elastic body, and The surface of the charging member has a speed difference with respect to the surface of the electrophotographic photosensitive member, and by carrying conductive particles at least on the contact surface between the charging member and the electrophotographic photosensitive member, sufficient contact can be achieved in direct charging. Property, and uniform charging is possible, so that the photoreceptor used in the device is subjected to a larger load, and it is difficult to achieve durability against abrasion and scratches due to rubbing as a protective layer. The demands placed on the layers are more stringent.

An object of the present invention is to solve the above problems, and to provide an electrophotographic photosensitive member which is free from peeling of a protective layer due to durability of repeated use, and which is excellent in abrasion resistance and electrophotographic characteristics. It is in.

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

[0030]

According to the present invention, in an electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, the protective layer comprises conductive particles, at least one of a charge transport material and a thermosetting material. The protective layer containing a resin is formed through a multi-step drying temperature in the drying process after coating, and the initial drying temperature (A ° C) is within ± 25 ° C of the boiling point of the solvent used for the coating composition of the protective layer. And the initial drying time is 15 seconds or more and 15 minutes or less, and the total time of multi-stage drying excluding the initial drying time is 20 minutes or more and 120 minutes or less.

Further, according to the present invention, there are provided a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

In an electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, the protective layer contains a thermosetting resin and at least one of conductive particles or a charge transport material, and the protective layer is coated. In the subsequent drying process, the initial drying temperature (A ° C.) is formed through a multi-step drying temperature, the solvent used for the coating material of the protective layer is within the boiling point ± 25 ° C., and the initial drying time is 15 seconds or more 15 seconds or more. It is important that the total time for the multistage drying is 20 minutes or more and 120 minutes or less, excluding the initial drying time.

By conducting the drying in multiple stages, the conductive particles contained in the protective layer do not locally have high heat, and the conductive particles do not peel off in the continuous printing durability test, and a good image is obtained. Can be output. Further, even when the charge transport material is contained in the protective layer, the surrounding resin for the protective layer does not solidify at once, so that the optimal arrangement can be achieved and the charge transport function can be sufficiently exerted. , A good image can be output. Furthermore, when the drying is performed in multiple stages, the initial drying temperature is also important.

When an electrophotographic photosensitive member whose initial drying is performed at a temperature higher than the boiling point of the solvent + 25 ° C. or a temperature lower than the boiling point -25 ° C. is used in an electrophotographic apparatus, a black spot image is generated when the durability is increased. This is because when the initial drying temperature is too low, the solvent remains in the protective layer even after the initial drying, and the solvent is volatilized at one time in the drying in the subsequent step, so that between the protective layer and the lower layer,
It is expected that a void like a small bubble is formed, bubbles remain in the protective layer, and when the protective layer is scraped off during durability, the light potential changes only in the bubble portion and is output as a black spot image. Further, even if the initial drying temperature is too high, the solvent in the protective layer evaporates at once, so that the conductive particles contained in the protective layer locally as in the case where the drying is not performed in multiple stages. As it has high heat and the solvent around the conductive particles evaporates at once, a void is created between the conductive layer and the protective layer resin, creating a gap, and the conductive particles peel off in the continuous printing durability test. , It appears in the image as a black spot. In addition, the charge transport material contained in the protective layer causes the surrounding resin for the protective layer to solidify at once by drying the protective layer at once, which hinders the molecular motion of the charge transport material and prevents the overlap of π electrons. If it cannot be made, the charge transport function will not be fully exerted, and as a result, a state of low concentration will be created.

Further, if the initial drying time is set to less than 15 seconds, the solvent in the film cannot be sufficiently removed, and as a result, the solvent is removed by giving a large amount of heat in the post-drying step. Then, the same thing as described above occurs.

On the other hand, it was found that if the initial drying temperature was longer than 15 minutes, the abrasion resistance was poor. This is because relatively low molecular weight substances involved in curing in the protective layer permeate into the lower layer, and as a result, relatively large molecular weight substances increase in the film, making it difficult for the molecules to move, so heat curing It is considered that the reaction is not performed sufficiently.

That is, the protective layer contains a thermosetting resin and at least one of conductive particles or a charge transport material, and the protective layer is formed in a drying process after coating and undergoes a multi-step drying temperature, It has been found that it is important that the initial drying temperature (A ° C.) is within the boiling point ± 25 ° C. of the solvent used for the coating material for the protective layer and the initial drying time is 15 seconds or more and 15 minutes or less.

Further, even if the initial drying conditions are set as described above, it is possible to control the drying process performed later.
It was found that a useful electrophotographic photoreceptor having a protective layer can be obtained.

It is generally known that the thermosetting resin cures better when the drying time is longer at the curing temperature. However, in the electrophotographic photosensitive member using the protective layer of the present invention, a phenomenon in which the image density becomes low was observed when drying was performed for more than 120 minutes. It is presumed that this was caused by the fact that the sensitivity of the electrophotographic photosensitive member was deteriorated due to the large heat history, and the bright portion potential was increased.

On the contrary, when the drying time was less than 20 minutes, it was found that the protective layer was not sufficiently cured and the abrasion resistance was poor.

For these reasons, when a plurality of solvents are mixed and used, the initial drying temperature (A ° C.) is -25 ° C. or higher (lower limit), which is the lowest boiling point of the solvent, and the highest boiling point. It is necessary that the boiling point of the solvent is higher than + 25 ° C. (upper limit).

As a result of intensive studies, the present inventors have found that when a thermosetting resin is used for the protective layer in order to obtain the characteristics as an electrophotographic photoreceptor and the desired hardness as the protective layer, We have found the exquisite conditions for volatilizing the solvent and for sufficient curing.

On the other hand, in the present invention, the upper limit of the initial drying temperature is lower than the curing start temperature of the thermosetting resin even if the boiling point of the solvent is within + 25 ° C. Easy to obtain layers. So in the initial drying,
This means that the protective layer is not cured. It was thought that this is because what was once cured and activated in the initial drying was deactivated before the post-drying and was not sufficiently cured in the post-drying. By the way, in the present invention, the thermosetting start temperature means that the composition is cured after being cured at that temperature for 1 hour. Further, "not cured" was defined as that the protective layer of the electrophotographic photosensitive member was wiped off when wiped with a cloth impregnated with an organic solvent. On the contrary, curing means that the protective layer cannot be wiped off when wiped with a cloth impregnated with an organic solvent.

The thermosetting resin which is the binder resin used in the protective layer in the present invention includes melamine resin, phenol resin,
Phenolic resin is preferable because it is at least one of epoxy resin and isocyanate resin, and many of them cure at a relatively reasonable temperature.

The thermosetting phenolic resin is a resin generally obtained by the reaction of phenols and formaldehyde. There are two types of phenolic resin. Resol type obtained by adding formaldehyde to phenols in excess and reacting with an alkali catalyst, and novolac obtained by adding phenols to formaldehyde in excess and reacting with acid catalyst. It is roughly divided into types.

The resol type is soluble in solvents such as alcohols and ketones, and is heated to be three-dimensionally cross-linked and polymerized to form a cured product. On the other hand, the novolac type generally does not cure when heated as it is, but a cured product is produced by adding a formaldehyde source such as paraformaldehyde or hexamethylenetetramine and heating.

Generally, industrially, resole is used as a varnish for paints, adhesives, cast products and laminated products, and novolac is mainly used as a molding material and a binder.

The phenol resin, which is a thermoplastic resin used as the binder resin in the present invention, can be used in both the above-mentioned resol type and novolac type, but it can be cured without adding a curing agent, and can be used in paints. It is preferable to use a resol type from the viewpoint of operability and the like.

In the present invention, these phenolic resins may be used alone or in combination of two or more, and it is also possible to use a mixture of resole type and novolak type. The phenol resin used in the present invention may be any known phenol resin.

Usually, the resol type phenol resin is produced by subjecting a phenol compound and an aldehyde compound to an alkali catalyst. The main phenols used include, but are not limited to, phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcin and bisphenol. The aldehydes include, but are not limited to, formaldehyde, paraformaldehyde, furfural, acetaldehyde and the like.

Monomers of phenols, dimethylolphenols, trimethylolphenols, and their mixtures, or their oligomers, which are obtained by reacting these phenols with aldehydes under an alkaline catalyst, and Make a mixture of monomers and oligomers. Among them, a relatively large molecule having a repeating structural unit of 2 to 20 is an oligomer, and one is a monomer.

The alkali catalysts used include metal-based alkali compounds, ammonia and amine compounds, and the metal-based alkali compounds include NaOH and KOH.
And hydroxides of alkali metals and alkaline earth metals such as Ca (OH) _{2 and the} like, and amine compounds include ammonia, hexamethylenetetramine, trimethylamine, triethylamine and triethanolamine, but are not limited thereto. Not something. Among them, ammonia and amine compounds are preferably used, and amine compounds are more preferably used in consideration of stability.

The protective layer of the present invention is formed by coating the photosensitive layer with a coating material obtained by dissolving or diluting a thermosetting resin in a solvent or the like. After the coating, a polymerization reaction occurs to form a cured layer. To do. As a form of polymerization, the reaction proceeds by addition and condensation reaction by heat, and after coating the protective layer, heating causes a polymerization reaction to form a polymer cured layer.

The protective layer of the present invention does not essentially move a charge as a resistor, but moves the charge by at least one of the conductive particles and the charge transporting material contained in the protective layer, and thus the protective layer. It maintains the sensitivity of the electrophotographic photosensitive member which has been subjected to, and lowers the residual potential. Therefore, it is not necessary to set the volume resistivity of the resistor to be low, and by setting the volume resistivity to 1 × 10 ¹² Ω · cm or more, the flow of the electrostatic latent image formed can be made higher. Can be suppressed.

The conductive particles in the present invention play an auxiliary role of adjusting the volume resistivity of the protective layer, and are not necessarily used if not necessary.

The conductive particles used in the protective layer of the present invention include metals and metal oxides. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, stainless steel, and the like, or those obtained by vapor-depositing these metals on the surface of plastic particles. Examples of the metal oxides include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony or tantalum, and zirconium oxide doped with antimony. . These may be used alone or in combination of two or more. When two or more kinds are used in combination, they may be simply mixed, or may be in the form of solid solution or fusion.

Further, in the present invention, it is particularly preferable to use a metal oxide among the above-mentioned various conductive particles from the viewpoint of transparency. Further, among these metal oxides, it is particularly preferable to use tin oxide from the viewpoints of transparency, dispersibility, resistance controllability and the like. The tin oxide used here may be subjected to surface treatment or the like for the purpose of improving dispersibility and liquid stability, and may be doped with antimony or tantalum for the purpose of improving resistance controllability.

The average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less in view of transparency of the protective layer.

Since the film strength becomes weaker as the amount of the conductive particles increases, it is preferable to reduce the amount of the conductive particles within a range in which the volume resistance and the residual potential of the protective layer are allowable.

The lubricating particles used in the present invention are preferably fluorine atom-containing resin particles, silicone resin particles, silica particles and alumina particles, and more preferably fluorine atom-containing resin particles. Further, two or more of these may be mixed.

The fluorine atom-containing resin particles include tetrafluoroethylene, trifluoroethylene chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and the like. It is preferable to appropriately select one kind or two or more kinds from the copolymers, and a tetrafluoroethylene resin and a vinylidene fluoride resin are particularly preferable. The molecular weight distribution of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited.

Inorganic particles such as silica particles and alumina particles may not work as lubricating particles as a single particle, but by dispersing and adding them, the surface roughness of the surface protective layer increases. As a result, it has been clarified by the study by the present inventors that the lubricity of the surface protective layer is increased. The term “lubricious particles” as used herein includes particles that impart lubricity.

The fluorine atom-containing resin is added together with the conductive particles in the resin solution so that the mutual particles are not aggregated, and the fluorine atom-containing compound is added during the dispersion of the conductive particles, or the surface of the conductive particles is covered with fluorine atoms. It is preferable to carry out a surface treatment with a contained compound. By adding a fluorine atom-containing compound or subjecting the conductive particles to a surface treatment, the dispersibility and dispersion stability of the conductive particles and the fluorine atom-containing resin particles in the resin solution are higher than in the case where there is no fluorine atom-containing compound. Has improved significantly. In addition, by forming a secondary particle of dispersed particles by dispersing fluorine atom-containing resin particles in a liquid in which a fluorine atom-containing compound is added and conductive particles are dispersed, or in which a surface-treated conductive particle is dispersed. In addition, a coating liquid having excellent dispersibility that is very stable over time can be obtained.

Examples of the fluorine atom-containing compound in the present invention include fluorine-containing silane coupling agents, fluorine-modified silicone oils and fluorine-based surfactants.
Examples of preferable compounds are shown in Tables 1 to 3, but the present invention is not limited to these compounds.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

The surface treatment of the conductive particles is carried out by mixing and dispersing the conductive particles and the surface treating agent in a suitable solvent,
A surface treatment agent is attached to the surface of the conductive particles. As a dispersing method, a usual dispersing means such as a ball mill or a sand mill can be used. Next, the solvent may be removed from this dispersion solution and fixed on the surface of the conductive particles. Further, if necessary, a heat treatment may be further performed thereafter. Also,
A catalyst for accelerating the reaction can be added to the treatment liquid. Furthermore, if necessary, the surface-treated conductive particles can be further pulverized.

The ratio of the fluorine atom-containing compound to the conductive particles is influenced by the particle size, shape and surface area of the particles, but is 1 to 6 relative to the total mass of the surface-treated conductive particles.
5 mass% is preferable, and especially 1 to 50 mass% is preferable.

Further, in the present invention, in order to form a protective layer having more environmental stability, a siloxane compound represented by the following formula (I) is added at the time of dispersing conductive particles, or the following formula (I) is added. By mixing the conductive particles surface-treated with the siloxane compound represented by, it is possible to obtain a protective layer which is more excellent in environmental stability.

[0072]

[Chemical 8]

In the formula, A is a hydrogen atom or a methyl group,
Moreover, the ratio of hydrogen atoms in all A is 0.1 to 50.
%, Α is an integer of 0 or more.

By adding the siloxane compound and then dispersing the coating solution or the surface-treated conductive metal oxide fine particles in a binder resin dissolved in a solvent, secondary particles of dispersed particles are also formed. In addition, a coating liquid that is stable and has good dispersibility over time can be obtained, and a protective layer formed from this coating liquid has high transparency and is particularly excellent in environmental resistance.

The molecular weight of the siloxane compound represented by the general formula (I) is not particularly limited, but when the surface treatment is performed, it is preferable that the viscosity is not too high because of its easiness, and the weight average molecular weight is A few hundred to tens of thousands is suitable.

There are two types of surface treatment methods, wet and dry. In the wet method, the conductive metal oxide particles are dispersed in a solvent with a siloxane compound represented by the general formula (I), and the siloxane compound is attached 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 solution is fixed to the surface of the conductive metal oxide fine particles. In this heat treatment, the Si—H bond in siloxane undergoes oxidation of hydrogen atoms due to oxygen in the air during the heat treatment process to form a new siloxane bond. As a result, siloxane develops into a three-dimensional structure, and the surface of the conductive metal oxide fine particles is covered with this network structure. In this way, the surface treatment is completed by fixing the siloxane compound to the surface of the conductive metal oxide fine particles, but the fine particles after the treatment may be subjected to a crushing treatment, if necessary. In the dry treatment, the siloxane compound and the conductive metal oxide fine particles are mixed and kneaded without using a solvent to adhere the siloxane compound to the fine particle surface. After that, heat treatment and crushing treatment are performed in the same manner as the wet treatment to complete the surface treatment.

The electron transporting material which can be contained in the protective layer of the present invention is preferably a compound having at least one hydroxyl group in the molecule, and particularly, a compound having at least one phenol group in the molecule, A compound having at least one substituent selected from a hydroxyalkyl group, a hydroxyalkoxy group and an optionally substituted hydroxyphenyl group is preferable.

The charge transport material having at least one substituent selected from the group consisting of hydroxyalkyl group, hydroxyalkoxy group and optionally substituted hydroxyphenyl group used in the present invention is represented by the following formulas (1) to (6). It is preferable that it is a compound shown by any one of.

[0079]

[Chemical 9]

In the formula, R ₁ , R ₂ and R ₃ each represent a divalent hydrocarbon group having 1 to 8 carbon atoms which may be branched,
α, β and γ each have a halogen atom as a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a substituent. Represents a benzene ring which may have one or more heterocyclic groups, wherein a, b and d are 0 or 1, and m and n are 0 or 1.

[0081]

[Chemical 10]

In the formula, R ₄ , R ₅ and R ₆ each represent a divalent hydrocarbon group having 1 to 8 carbon atoms which may be branched,
δ and ε each have a halogen atom as a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a substituent. Represents a benzene ring which may have one or more heterocyclic groups, and e, f and g are 0 or 1. p, q, and r are 0 or 1, and all cannot be 0 at the same time. Z ₁ and Z ₂ may each have a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a substituent. It represents a good heterocyclic group and may form a ring together.

[0083]

[Chemical 11]

In the formula, R ₇ , R ₈ , R ₉ and R ₁₀ each represent a divalent hydrocarbon group having 1 to 8 carbon atoms which may be branched, and ζ, η, θ and ι are substituents. Is a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent. One or more benzene rings are shown, h, i, j and k are 0 or 1, and s, t and u are 0 or 1. Z ₃ and Z ₄
Are a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent. They may be shown and jointly formed into a ring.

[0085]

[Chemical 12]

Where R₁₁Is a C1-C8 branched
Is a divalent hydrocarbon group, R ₁₂Is a hydrogen atom, substitution
An alkyl group which may have a group and an alkyl group which may have a substituent
Aralkyl group or phenyl group which may have a substituent is shown.
You Ar₁And Ar₂Is an alkyl which may have a substituent
Group, optionally substituted aralkyl group, optionally substituted
Optionally substituted aryl group or optionally substituted heterocyclic group
Indicates. Ar₃Is an arylene group which may have a substituent or
Represents a heterocyclic group which may have a divalent substituent. v and
w is 0 or 1, respectively. However, when v = 0, w
= 0. κ and λ are halogens as substituents
Atom, optionally substituted alkyl group, having substituent
Optionally alkoxy group, aryl optionally having substituent (s)
Having one or more heterocyclic groups which may have groups or substituents
Represents a good benzene ring.

[0087]

[Chemical 13]

In the formula, R ₁₃ represents a divalent hydrocarbon group having 1 to 8 carbon atoms which may be branched. Ar ₄ and Ar ₅ are an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent. Indicates. μ and ν each have a halogen atom as a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a substituent. Represents a benzene ring which may have one or more heterocyclic groups. In addition,
μ and ν may jointly form a ring via a substituent. x is 0 or 1.

[0089]

[Chemical 14]

In the formula, R ₁₄ and R ₁₅ are each a carbon number of 1 to 1.
8 represents an optionally branched divalent hydrocarbon group. Ar
₆ represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent. ξ, π, ρ
And σ each have a halogen atom as a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or a substituent. A benzene ring which may have one or more good heterocyclic groups is shown. Incidentally, ξ and π and ρ and σ may jointly form a ring via a substituent. y and z are 0 or 1, respectively.

The structures of the substituents and the like in the above formulas (1) to (6) will be described in detail below.

In the formula, R _{1 to} R ₁₁ and R _{13 to} R ₁₅ are divalent hydrocarbon groups such as methylene group, ethylene group, propylene group and butylene group which may be branched and have 1 to 8 carbon atoms. Indicates. R ₁₂ is a hydrogen atom, an alkyl group such as a methyl group which may have a substituent, an ethyl group, a propyl group and a butyl group, an aralkyl group such as a benzyl group which may have a substituent, a phenethyl group and a naphthylmethyl group. Group or phenyl group.

Where α, β, γ, δ, ε, ζ, η, θ,
The substituents that the benzene ring represented by ι, κ, λ, μ, ν, ξ, π, ρ and σ may have include a halogen atom such as fluorine, chlorine, bromine and iodine and a substituent. Methyl group, ethyl group, alkyl group such as propyl group and butyl group, optionally substituted methoxy group, ethoxy group,
An alkoxy group such as a propoxy group and a butoxy group, a phenyl group which may have a substituent, a naphthyl group, an aryl group such as an anthryl group and a pyrenyl group, or a pyridyl group which may have a substituent, a thienyl group, a furyl group. And a heterocyclic group such as a quinolyl group. μ and ν, ξ and π, and ρ and σ may form a cyclic structure such as a fluorene skeleton or a dihydrophenanthrene skeleton through a substituent or the like which is bonded together.

In the formula, Z _{1 to} Z ₄ are a halogen atom such as fluorine, chlorine, bromine and iodine, an alkyl group which may have a substituent, an alkyl group such as an ethyl group, a propyl group and a butyl group and a substituent. A methoxy group which may have, an ethoxy group, an alkoxy group such as a propoxy group and a butoxy group, a phenyl group which may have a substituent, a naphthyl group, an aryl group such as an anthryl group and a pyrenyl group, or a substituent The heterocyclic groups such as pyridyl group, thienyl group, furyl group and quinolyl group which may be present are shown. Z ₁ and Z ₂ and Z ₃ and Z ₄ may form a cyclic structure such as a fluorene skeleton or a dihydrophenanthrene skeleton through a biphenyl skeleton to which they are jointly bonded.

In the formula, Ar ₁ , Ar ₂ , Ar ₄ , Ar ₅ and A
r ₆ is a methyl group which may have a substituent, an alkyl group such as an ethyl group, a propyl group and a butyl group, a benzyl group which may have a substituent, an aralkyl group such as a phenethyl group and a naphthylmethyl group, a substituent Represents an aryl group such as a phenyl group which may have a group, a naphthyl group, an anthryl group and a pyrenyl group, or a heterocyclic group which may have a substituent, such as a pyridyl group, a thienyl group, a furyl group and a quinolyl group. . Ar
₃ represents an arylene group such as a phenylene group, a naphthylene group, an anthrylene group and a pyrenylene group which may have a substituent, or a divalent heterocyclic group such as a pyridylene group or a thienylene group.

In the formulas (1) to (6), the substituent which may be possessed is an alkyl group such as methyl group, ethyl group, propyl group and butyl group, aralkyl group such as benzyl group, phenethyl group and naphthylmethyl group. Group, phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group,
Carbazolyl group, aromatic ring group such as dibenzofuryl group and dibenzothiophenyl group, alkoxy group such as methoxy group, ethoxy group and propoxy group, aryloxy group such as phenoxy group and naphthoxy group, fluorine, chlorine, bromine and iodine etc. Examples thereof include a halogen atom, a nitro group and a cyano group.

The charge-transporting material used in the protective layer in the present invention has good compatibility with the phenol resin, and a protective layer film uniformly dispersed can be easily prepared, but in order to further improve the compatibility. , In the formulas (1) to (3), R
_The divalent hydrocarbon group represented by _{1 to} R ₁₀ preferably has 4 or less carbon atoms, and the number of hydroxyalkyl groups and hydroxyalkoxy groups is preferably 2 or more. Further, in the formulas (4) to (6), the phenol residue contained in the charge transport material reacts with the phenol resin to incorporate the charge transport material into the protective layer matrix, and the strength as the protective layer becomes stronger. .

The charge transport material having a specific structure of formulas (1) to (6) used in the present invention is uniformly dissolved or dispersed in a coating liquid for preparing a protective layer, and formed by coating. To do. The mixing ratio of the charge transport material of the formulas (1) to (6) and the thermoplastic resin is, in mass ratio, charge transport material / thermoplastic resin = 0.1 / 10 to 20/10, preferably 0.5.
/ 10 to 10/10 is preferable. If the amount of the charge transport material is too small with respect to the thermoplastic resin, the effect of lowering the residual potential becomes small, and if it is too large, the strength of the protective layer may be lowered.

The formulas (1) to (1) used in the present invention will be described below.
Specific examples of the charge transport material represented by (6) are shown below. However, the charge transport material of the present invention is not limited to these.

[0100]

[Chemical 15]

[0101]

[Chemical 16]

[0102]

[Chemical 17]

[0103]

[Chemical 18]

[0104]

[Chemical 19]

[0105]

[Chemical 20]

[0106]

[Chemical 21]

[0107]

[Chemical formula 22]

[0108]

[Chemical formula 23]

[0109]

[Chemical formula 24]

[0110]

[Chemical 25]

[0111]

[Chemical formula 26]

[0112]

[Chemical 27]

As the solvent for dispersing the coating material for the protective layer, the thermoplastic resin is sufficiently dissolved, and the charge transport materials represented by the formulas (1) to (6) are also sufficiently dissolved. Its dispersibility is good, and when using lubricating particles such as fluorine atom-containing compounds, fluorine atom-containing resin particles and siloxane compounds, compatibility and processability are good, and further, a charge transport layer that comes into contact with the coating material of the protective layer. A solvent that does not adversely affect the above is preferable.

Therefore, as the solvent, alcohols such as methanol, ethanol and 2-propanol, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethers such as tetrahydrofuran and dioxane, toluene and xylene. It is possible to use aromatic hydrocarbons such as, and halogen-based hydrocarbons such as chlorobenzene and dichloromethane, and these may be mixed and used to prevent cracks and film thickness sagging. Further, when mixed, the initial drying temperature is preferably between the higher boiling point and the lower boiling point of the solvent, though it depends on the mixing ratio. If it is adjusted to a lower boiling point, the solvent in the protective layer cannot be sufficiently removed, and the above-mentioned problems occur.If it is adjusted to a higher boiling point, the drying time is shorter in the initial drying and the lower volatile solvent is used. However, it is likely to evaporate at once and cause the same problem. However, the boiling point is not limited to this as long as it has a close boiling point. Of these, the most suitable solvents in the form of thermoplastic resins, especially phenolic resins, are alcohols such as methanol, ethanol and 2-propanol.

Conventional charge transport materials are generally insoluble or sparingly soluble in alcoholic solvents, and it is difficult to uniformly disperse them in a general phenol resin. However, the formula (1) used in the present invention is difficult. Since most of the charge transport materials shown in (6) to (6) are soluble in a solvent containing alcohols as a main component, they can be dispersed in a phenol resin coating liquid.

As the method for applying the protective layer of the present invention, a general coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method and a blade coating method can be used. it can.

If the protective layer of the present invention is too thin, the durability of the electrophotographic photosensitive member will be impaired, and if it is too thick, the residual potential will increase due to the provision of the protective layer. There is. Specifically, the range of 0.1 μm to 10 μm is preferable, and the range of 0.5 μm to 7 μm is more preferable.

In the present invention, an antioxidant additive may be added to the protective layer for the purpose of preventing deterioration of the protective layer due to adhesion of active substances such as ozone and NOx generated during charging. .

Next, the photosensitive layer will be described below.

The electrophotographic photosensitive member of the present invention preferably mainly has a laminated structure. The electrophotographic photoreceptor of FIG. 1A has a charge generation layer 3 and a charge transport layer 2 on a conductive support 4.
Are sequentially provided, and the protective layer 1 is further provided on the outermost surface. Further, as shown in FIGS. 1B and 1C, a binding layer 5 and a subbing layer 6 for the purpose of preventing interference fringes may be provided between the conductive support and the charge generation layer. .

As the conductive support 4, a support itself having conductivity, for example, aluminum, aluminum alloy or stainless steel can be used. In addition, aluminum, aluminum alloy, indium oxide-tin oxide alloy or the like can be used. A support in which the above-mentioned conductive support having a layer formed by vacuum deposition, plastic, or conductive fine particles (for example, carbon black, tin oxide, titanium oxide and silver particles) is impregnated into plastic or paper together with a suitable binder. A body, a plastic having a conductive binder, or the like can be used.

A binding layer (adhesive layer) having a barrier function and an adhesive function may be provided between the conductive support and the photosensitive layer. The binder layer is for improving the adhesiveness of the photosensitive layer, improving the coating property, protecting the support, covering the defects of the support, improving the charge injection property from the support, protecting the photosensitive layer against electrical breakdown, etc. It is formed. The binder layer can be formed of casein, polyvinyl alcohol, ethyl cellulose, ethylene-acrylic acid copolymer, polyamide, modified polyamide, polyurethane, gelatin or aluminum oxide. The thickness of the binder layer is preferably 5 μm or less, and is 0.1
˜3 μm is more preferred.

The charge generating material used in the present invention includes (1) azo pigments such as monoazo, disazo and trisazo, (2) phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine, (3) indigo and thioindigo, etc. Indigo pigments, (4) perylene pigments such as perylene anhydride and perylene imide, (5) polycyclic quinone pigments such as anthraquinone and pyrenequinone,
(6) squarylium dye, (7) pyrylium salt and thiapyrylium salt, (8) triphenylmethane dye,
(9) Inorganic substances such as selenium, selenium-tellurium, and amorphous silicon, (10) quinacridone pigment, (11) azurenium salt pigment, (12) cyanine dye, (13) xanthene dye, (14) quinoneimine dye, (15) Examples thereof include styryl dyes, (16) cadmium sulfide, and (17) zinc oxide.

Examples of the binder resin used for the charge generation layer include polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin,
Polyvinyl acetal resin, diallyl phthalate resin,
Acrylic resin, methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin, alkyd resin, epoxy resin, urea resin, vinyl chloride-vinyl acetate copolymer resin, and the like. However, the present invention is not limited to these. These can be used alone or as a mixture or as a copolymer of one kind or two or more kinds.

The solvent used for the charge generation layer coating material is selected from the solubility and dispersion stability of the resin and charge generation material used, but as the organic solvent, alcohols, sulfoxides, ketones, ethers and esters are used. , Aliphatic halogenated hydrocarbons, aromatic compounds and the like can be used.

In the charge generating layer 3, the above charge generating material is well dispersed together with 0.3 to 4 times the amount of the binder resin and the solvent by a method such as a homogenizer, ultrasonic wave, ball mill, sand mill, attritor or roll mill. It is applied, dried and formed. The thickness is preferably 5 μm or less, and particularly preferably in the range of 0.01 to 1 μm.

If necessary, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers or known charge generating materials can be added to the charge generating layer.

As the charge transport material used, various triarylamine compounds, various hydrazone compounds,
Examples include various styryl compounds, various stilbene compounds, various pyrazoline compounds, various oxazole compounds, various thiazole compounds, and various triarylmethane compounds.

The binder resin used to form the charge transport layer 2 includes acrylic resin, styrene resin, polyester, polycarbonate resin, polyarylate, polysulfone, polyphenylene oxide, epoxy resin,
Resins selected from polyurethane resins, alkyd resins, unsaturated resins and the like are preferable. As a particularly preferred resin,
Polymethylmethacrylate, polystyrene, styrene-
Examples thereof include acrylonitrile copolymer, polycarbonate resin and diallyl phthalate resin.

The charge transport layer 2 is generally formed by dissolving the above charge transport material and the binder resin in a solvent and coating the solution. The mixing ratio of the charge transport material and the binder resin is about 2: 1 to 1: 2. As the solvent, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene,
Chlorinated hydrocarbons such as chlorobenzene, chloroform and carbon tetrachloride are used. 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. In the temperature range of
It is preferably 5 minutes to 5 hours, more preferably 10 minutes to 2 hours and can be performed under blast drying or static drying.

The charge transport layer is electrically connected to the above-described charge generation layer, receives charge carriers injected from the charge generation layer in the presence of an electric field, and serves as a protective layer for these charge carriers. It has the function of transporting to the interface. Since this charge transport layer has a limit for transporting charge carriers, the film thickness cannot be increased more than necessary.
-40 μm is preferable, and a range of 7-30 μm is particularly preferable.

Further, an antioxidant, an ultraviolet absorber, a plasticizer or a known charge transport material may be added to the charge transport layer as needed.

Further, the present invention is completed by applying the above-mentioned protective layer on the charge transport layer and curing it to form a film.

FIG. 2 shows a schematic structure of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 2, reference numeral 11 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around the shaft 12 in the direction of the arrow at a predetermined peripheral speed. In the rotating process, the electrophotographic photosensitive member 11 is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the primary charging unit 13, and then, an exposing unit (not shown) such as slit exposure or laser beam scanning exposure.
The exposure light 14 intensity-modulated corresponding to the time-series electric digital image signal of the target image information output from 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.

The electrostatic latent image thus formed is then developed by the developing means 1.
5, the toner is developed with toner, and the electrophotographic photosensitive member 11 is provided between the electrophotographic photosensitive member 11 and the transfer unit 16 from a paper feeding unit (not shown).
Of the transfer material 17 taken out and fed in synchronization with the rotation of the
Then, the toner images formed and carried on the surface of the electrophotographic photosensitive member 11 are sequentially transferred by the transfer unit 16.

The transfer material 17 that has received the transfer of the toner image is
After being separated from the surface of the electrophotographic photosensitive member and being introduced into the image fixing means 18 to undergo image fixing, it is printed out as an image formed product (print, copy) to the outside of the apparatus.

The surface of the electrophotographic photosensitive member 11 after the image transfer is
The cleaning unit 19 removes the residual toner after transfer to make it a clean surface, and is subjected to charge elimination processing by pre-exposure light 20 from a pre-exposure unit (not shown), and then repeatedly used for image formation. If the primary charging means 13 is a contact charging means using a charging roller or the like, pre-exposure is not always necessary.

In the present invention, among the above-mentioned electrophotographic photosensitive member 11, primary charging means 13, developing means 15, cleaning means 19 and the like, a plurality of components are housed in a container and integrally combined as a process cartridge. The process cartridge may be detachably attached to the main body of the electrophotographic apparatus 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 the cartridge is attached to and detached from the apparatus main body by using a guide unit 22 such as a rail of the apparatus main body. The process cartridge 21 can be freely used.

When the electrophotographic apparatus is a copying machine or a printer, the exposure light 14 is reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal,
Laser beam scanning and LE performed according to this signal
The light is emitted by driving the D array, driving the liquid crystal shutter array, or the like.

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

FIG. 3 has the electrophotographic photosensitive member of the present invention,
1 shows a schematic configuration of an electrophotographic apparatus including an injection charging type process cartridge.

(Overall Schematic Structure of Image Recording Apparatus) 31
Is an image bearing member, and in this embodiment, is a rotating drum type negative polarity OPC photosensitive member (negative photosensitive member, hereinafter referred to as electrophotographic photosensitive member) having a diameter of 24 mm. The electrophotographic photosensitive member 31 is rotationally driven in a clockwise direction indicated by an arrow at a constant peripheral speed of 47 mm / sec (= process speed PS, printing speed). The electrophotographic photosensitive member 31 will be described in detail in another section.

The charging device 32 is a particle charging type contact charging device, and the charging roller 32 as a contact charging member.
And a charging bias applying power source S1 for the charging roller.

The charging roller 32 is composed of a cored bar 32a and an elastic / medium resistance layer 32b of rubber or foam as a charged particle carrier formed concentrically and integrally on the outer periphery of the cored bar 32a. The outer peripheral surface of the elastic / medium resistance layer 32b is configured to carry charged particles (conductive particles) m. The charging roller 32 is pressed and brought into contact with the electrophotographic photosensitive member 31 with a predetermined amount of penetration, and the charging contact portion n having a predetermined width is n.
Is being formed. The charged particles m carried on the charging roller 32 come into contact with the surface of the electrophotographic photosensitive member 31 at the charging contact portion n.

The charging roller 32 is rotationally driven in the same arrow direction as the electrophotographic photosensitive member 31, and is rotated in the charging contact portion n in the direction opposite to the rotating direction of the electrophotographic photosensitive member 31 (counter), so that the charged particles m are removed. It comes into contact with the surface of the electrophotographic photosensitive member 1 with a speed difference.

Charging roller 3 for electrophotographic photosensitive member 31
The relative speed difference of 2 can also be provided by rotating the charging roller 32 in a direction opposite to that of the charging roller 32 (forward rotation direction of rotation of the electrophotographic photosensitive member 31) and rotating the peripheral speed. However,
Since the charging property of the direct injection charging depends on the ratio of the peripheral speed of the electrophotographic photosensitive member 31 to the peripheral speed of the charging roller 32, the charging roller 3
It is advantageous to rotationally drive 2 in the same direction as the electrophotographic photosensitive member 1 in terms of the number of revolutions, and it is preferable to adopt this configuration also in terms of particle retention.

At the time of image recording by the image recording apparatus, a predetermined charging bias is applied to the core metal 32a of the charging roller 32 from the charging bias applying power source S1.

As a result, the peripheral surface of the electrophotographic photosensitive member 31 is uniformly contact-charged to a predetermined polarity and potential by the direct injection charging method. In this example, a charging bias of −600V was applied to the core metal 32a of the charging roller 32 from the charging bias applying power source S1 to obtain the same charging potential on the surface of the electrophotographic photosensitive member 31 as the applied charging bias.

The charged particles m applied to the outer peripheral surface of the charging roller 32 are the electrophotographic photosensitive member 3 formed by the charging roller 32.
Along with the charging of 1, the toner is attached to the surface of the electrophotographic photosensitive member 31 and carried away.

The charged particles m are added to the developer t of the developing device 35 and adhere to the surface of the electrophotographic photosensitive member 31 together with the toner during the development of the electrostatic latent image on the electrophotographic photosensitive member 31, and the electrophotographic photosensitive member 31. By being carried to the charging contact portion n by the rotation of, the toner is supplied to the charging roller 32 via the electrophotographic photosensitive member 31.

The charging device 32 and the direct injection charging will be described in detail in another section.

A laser beam scanner (exposure device) 34 including a laser diode, a polygon mirror, etc. outputs a laser beam whose intensity is modulated corresponding to a time-series electric digital pixel signal of the target image information. The uniformly charged surface of the rotating electrophotographic photosensitive member 31 is subjected to scanning exposure L.

By this scanning exposure L, an electrostatic latent image corresponding to desired image information is formed on the surface of the rotary electrophotographic photosensitive member 31.

The developing device 35 is a reversal developing device using a one-component magnetic toner (negative toner).

In the developing device, the developer t and charged particles m are
And a mixture t + m of The electrostatic latent image on the surface of the rotating electrophotographic photosensitive member 31 is developed as a toner image at the developing portion a by the developing device 35.

That is, the image recording apparatus of the present example is a toner recycling process, and the transfer residual toner remaining on the surface of the electrophotographic photosensitive member 31 after the image transfer is not removed by a dedicated cleaner (cleaning device) and electronically transferred. As the photographic photosensitive member 31 rotates, the photographic photosensitive member 31 is carried to the charging contact portion n and temporarily collected by the charging roller 32 that counter-rotates with respect to the rotation of the electrophotographic photosensitive member 31 at the charging contact portion n.
As the toner is rotated around the outer circumference of the charging roller, the inverted toner charges are normalized and sequentially discharged to the electrophotographic photosensitive member 31 to reach the developing portion a, where they are collected and reused by the simultaneous developing cleaning in the developing device 35. .

A medium resistance transfer roller 36 as a contact transfer manual throw is pressed against the electrophotographic photosensitive member 31 at a predetermined pressure to form a transfer nip portion b. A transfer material P as a recording medium is fed to the transfer nip portion b from a paper feed portion (not shown) at a predetermined timing, and a predetermined transfer bias voltage is applied to the transfer roller 36 from a transfer bias applying power source S3. As a result, the toner image on the electrophotographic photosensitive member 31 side is sequentially transferred to the surface of the transfer material P fed to the transfer nip portion b.

The transfer roller 36 used in this example is a core metal 36.
A roller resistance value of 5 × with a medium resistance foam layer 36b formed on a
It is of 10 ⁸ Ω, and a voltage of +2.0 kV is applied to the core metal 36.
Transfer was performed by applying to a. The transfer material P introduced into the transfer nip portion b is conveyed while sandwiching the transfer nip portion b,
Toner images formed and carried on the surface of the rotary electrophotographic photosensitive member 31 are sequentially transferred to the surface side thereof by electrostatic force and pressing force.

In the fixing device 37 such as a heat fixing system, the transfer material P fed to the transfer nip portion b and transferred with the toner image on the electrophotographic photosensitive member 31 side is separated from the surface of the rotating electrophotographic photosensitive member 31. Then, the toner image is fixed to the fixing device 37, and the toner image is fixed and discharged as an image-formed product (print copy) to the outside of the device.

Then, the electrophotographic photosensitive member 31 is charged again by the charging device 32 and repeatedly used for image formation.

(3) Charging Roller 32 The charging roller 32 as a contact charging member in this example is
As described above, the core metal 32a and the elastic / medium resistance layer 32 of rubber or foam as a charged particle carrying member formed in a roller shape so as to be concentrically integrated with the outer periphery of the core metal 32a.
It consists of b. The charged particles (conductive particles) m are carried on the outer peripheral surface of the elastic / medium resistance layer 32b of the charging roller 32.

The elastic / medium resistance layer 32b is formulated with a resin (for example, urethane), conductive particles (for example, carbon black), a sulfiding agent, a foaming agent, etc., and is formed in a roller shape on the cored bar 32a. Then, the surface was polished.

The charging roller 32 as a contact charging member is
Particularly different from the commonly used charging roller for discharge in the following points: 1. Surface structure and roughness characteristics for supporting high-density charged particles m on the surface layer Resistance characteristics required for direct injection charging (volume resistance, surface resistance) (3) -1 Surface structure and roughness characteristics Conventionally, the roller surface by discharge is flat and the average surface roughness R
It is sub μm or less in a and the roller hardness is also high. In the charging using discharge, the discharge phenomenon occurs in a gap of several tens of μm, which is slightly apart from the contact portion between the roller and the body to be charged.
When the roller and the surface of the member to be charged have irregularities, the electric field strength is partially different and the discharge phenomenon becomes unstable, resulting in uneven charging. Therefore, the conventional charging roller requires a flat and hard surface.

Next, let us consider why injection charging cannot be carried out by the discharge charging roller. It seems that the surface structure as described above is in close contact with the drum, but at the molecular level required for charge injection. In the sense of micro contactability, there is almost no contact.

On the other hand, the charging roller 32 as the contact charging member in the present invention is required to have a certain degree of roughness because it needs to carry the charged particles m at a high density. With the average roughness Ra,
1 μm to 500 μm is preferable.

If it is smaller than 1 μm, the surface area for supporting the charged particles m becomes insufficient, and when an insulating material (for example, toner) adheres to the roller surface layer, the periphery thereof cannot contact the drum, and the charging performance deteriorates. .

Further, in consideration of the particle holding ability, it is preferable that the charged particles have a roughness larger than the particle diameter of the charged particles.

On the other hand, when it is larger than 500 μm, the unevenness of the roller surface reduces the in-plane charging uniformity of the body to be charged. Ra in this example was 50 μm.

For the measurement of the average roughness Ra, the surface shape measuring microscopes VF-7500 and VF7510 manufactured by Keyence Corp. were used to measure the shape and Ra of the roller surface in a non-contact manner using an objective lens of 250 times to 1250 times. .

(3) -2 Resistance Characteristics In a conventional charging roller using electric discharge, a low resistance base layer is formed on a core metal and then the surface is covered with a high resistance layer. The roller charging due to discharge has a high applied voltage, and if there is a pinhole (exposure of the support due to damage to the film), the voltage drops to the periphery thereof and charging failure occurs. Therefore, it is preferably set to 10 ¹¹ Ω or more.

On the other hand, in the direct injection charging method, since charging at a low voltage is possible, it is not necessary to make the surface layer of the contact charging member have high resistance, and the roller can be composed of a single layer. Rather, in the direct injection charging, the charging roller 32
It is preferable that the surface resistance is 10 ⁴ to 10 ¹⁰ Ω □.

When it is larger than 10 ¹⁰ Ω □, a large potential difference is generated on the roller surface, so that a discharging bias acts on the charged particles and the particles are easily discharged. Further, the uniformity on the charging surface is reduced, unevenness due to the rubbing of the rollers appears as streaks in the halftone image, and the image quality is degraded. On the other hand, when it is smaller than 10 ⁴ Ω □, peripheral voltage drop due to the drum pinhole is likely to occur even in the injection charging.

Further, regarding the volume resistance, 10 ⁴ to 10 ⁷
It is preferably in the range of Ω · cm. 10 ⁴ Ω · cm
If it is smaller than the above, the voltage drop of the power source due to the pinhole leak is likely to occur. On the other hand, if it is larger than 10 ⁷ Ω · cm, the electric current required for charging cannot be secured, and the charging voltage decreases.

The surface resistance and volume resistance of the charging roller 32 used in this embodiment were 10 ⁷ Ω □ and 10 ⁶ Ω · cm.

The resistance of the charging roller 32 was measured by the following procedure. FIG. 4 shows a schematic diagram of the structure at the time of measurement. The roller resistance is a total pressure of 9.8 on the core metal 32a of the charging roller 32.
An electrode was applied to an insulating drum 43 having an outer diameter of 24 mm and a measurement was performed so that a weight of N (1 kgf) was applied. The electrode is the main electrode 42
A guard electrode 41 is arranged around the
The measurement was performed using the wiring diagram shown in. The distance between the main electrode 42 and the guard electrode 41 was adjusted to about the thickness of the elastic / medium resistance layer 32b, and the main electrode 42 had a sufficient width with respect to the guard electrode 41. The main electrode 42 is measured from the power source S4 to +10
0 V was applied and the currents flowing through the ammeters Av and As were measured to measure the volume resistance and the surface resistance, respectively.

(3) -3 Other roller characteristics In the direct injection charging system, it is important that the contact charging member functions as a flexible electrode.

In the main charging device 32, the charging roller 3
This is achieved by adjusting the elastic characteristics of the second elastic / medium resistance layer 32b. The Asker C hardness is preferably in the range of 15 to 50 degrees. More preferably, it is 20 to 40 degrees.

If it is too high, the required amount of penetration cannot be obtained and the charging contact portion n cannot be secured between the charged body and the charged body, so that the charging performance is deteriorated. Further, since the molecular level contact property of the substance cannot be obtained, the contact with the periphery thereof is hindered by the inclusion of foreign matter or the like.

On the other hand, if the hardness is too low, the shape irregularity is not stable, so that the contact pressure with the body to be charged becomes uneven, resulting in uneven charging. Alternatively, a charging failure may occur due to permanent deformation strain of the roller due to long-term storage.

In this example, the charging roller 32 having an Asker C hardness of 22 degrees was used. Further, the charging roller 32 is arranged at an intrusion amount of 0.3 mm with respect to the electrophotographic photosensitive member 31, and in this example, a charging contact portion n of about 2 mm is formed.

(3) -4 Material, Structure, and Size of Charging Roller The material of the elastic / medium resistance layer 32b of the charging roller 32 is EPDM, urethane, NBR, silicone rubber, or the like.
Examples thereof include rubber materials in which a conductive material such as carbon black or metal oxide for adjusting resistance is dispersed in IR or the like. It is also possible to adjust the resistance by using an ion conductive material without dispersing the conductive substance. Thereafter, if necessary, surface roughness is adjusted and molding is performed by polishing or the like. Further, a structure having a plurality of layers with separated functions is also possible.

However, as the form of the elastic / medium resistance layer 32b of the charging roller 32, a porous structure is more preferable. It is also advantageous in manufacturing in that the above-mentioned surface roughness can be obtained at the same time when the roller is molded. The cell diameter of the foam is 1 to
500 μm is suitable. After foam molding, the surface of the porous body is exposed by polishing the surface, whereby the surface structure having the above-mentioned roughness can be produced.

Finally, the diameter is 6 mm and the longitudinal length is 240.
mm core metal 32a having a porous body surface, layer thickness 3 mm
The elastic / medium resistance layer 32b was formed, and the charging roller 32 having an outer diameter of 12 mm and a middle resistance layer longitudinal length of 220 mm was manufactured.

The charging roller 32 is arranged with an intrusion amount of 0.3 mm with respect to the electrophotographic photosensitive member 31 as a member to be charged,
In this embodiment, the charging contact portion n having a contact width of about 2 mm is formed.

(4) Charged Particle m The preferable volume resistance of the charged particle according to the present invention is 1 × 10.
⁻¹ to 1 × 10 ⁹ Ω · cm. When it exceeds 1 × 10 ⁹ Ω · cm, the effect of improving the charging property is not expected when used in an image forming method including a contact charging step. On the other hand, 1 × 1
If it is less than 0 ⁻¹ Ω · cm, the triboelectrification characteristics of the toner under high humidity will be impaired, and in addition to the deterioration of developability, fog and transferability are deteriorated. Since the contamination of the member is aggravated, the effect of improving the charging property due to the large specific surface area cannot be seen.

Here, the resistance of the particles is measured as follows. A cylindrical metal cell is filled with a sample, electrodes are arranged vertically so as to contact the sample, and a load of 7 k is applied to the upper electrode.
Add gf / cm ² . In this state, a voltage V is applied between the electrodes, and the resistance (volume resistivity Rv) is measured from the current I (A) flowing at that time. At this time, the electrode area is changed to S (c
m ² ) and the sample thickness is M (cm), Rv (Ω · cm) = V (V) × S (cm ² ) / I (A)
/ M (cm).

In this embodiment, the contact area S between the electrode and the sample is
= 2.26 cm ² and voltage V = 100V.

Examples of the charged particles in the present invention include fine metal powders of copper, gold, silver, aluminum, nickel and the like; zinc oxide, titanium oxide, tin oxide, aluminum oxide, indium oxide, silicon oxide, magnesium oxide,
Metal oxides such as barium oxide, molybdenum oxide, iron oxide, and tungsten oxide; metal compounds such as molybdenum sulfide, cadmium sulfide, potassium titanate, and conductive fine powders of composite oxides thereof can be used.

Among these, containing at least one kind of oxide selected from zinc oxide, tin oxide and titanium oxide allows the resistance of the charged particles to be set low, and it is white or light color, and it is It is preferable in that the transferred charged particles are not noticeable as fog.

Further, for the purpose of controlling the resistance value of the charged particles, fine particles of a metal oxide containing an element such as antimony or aluminum, fine particles having a conductive material on the surface, etc. can be used as the charged particles. For example, zinc oxide fine particles containing aluminum element, tin oxide fine particles containing antimony element, and the like. However, in general, resistance control by introducing an antimony element is not preferable because it increases the bluish blackness of the powder.

Also, the charged particles have a specific surface area of 5 × 10 ^5.
It is not less than cm ² / cm ^{3 and not} more than 1 × 10 ⁷ cm ² / cm ³ .

When the charged particles have magnetism, for example, when added to a magnetic toner, the fine particles released from the toner often adhere to the toner carrier and contaminate them. May be adversely affected.

Next, the contact densities between the charged particles and the toner particles and between the charged particles and the surface of the charging member will be considered.

When a particle, which is generally assumed to be spherical, contacts a member which is assumed to be substantially flat, the number of contact points is one. This also applies to the contact between the charged particles and the charging member or the toner particles. Therefore, in order to increase the number of contact points with the toner particles and the charging member, if a large number of irregularities are formed on the surface of the material, the number of contact points can be increased, and the number of contact points can be increased. However, it is never preferable to form a large number of irregularities on the surface of the toner particles in terms of triboelectric charging characteristics.
On the other hand, if unevenness is formed on the surface of the charged particles, not only the toner particles but also the number of contact points with the charging member are increased, which simplifies the design of the charging member and is preferable.

That is, forming and using a large number of irregularities on the surface of the charged particles is a technique that can be applied in a wide range without requiring special specifications for the printer main body and the toner used.

The specific surface area of the particle powder is usually used as an index of the number of irregularities on the particle surface. However, the specific surface area generally used is the surface area per unit mass, as can be seen from its unit, cm ² / g, and it is not easy to compare or optimize materials having different specific gravities in the discussion using this numerical value. .

Therefore, the inventors of the present invention, as a specific surface area, are physical properties corresponding to the surface area per fine particle, cm ² /
Using the unit of cm ³ , the relationship between the number of contact points between the charged particles, the toner and the charging member, and the image characteristics and the chargeability was earnestly examined.

As a result, an image forming method including a contact charging step
Method, the specific surface of the charged particles contained in the toner used
Product is 5 × 10^Fivecm²/ Cm³1 x 10 or more⁷cm²/ Cm³
When it is below, the charging property and the image characteristics are greatly improved.
Especially in the image forming method including the direct injection charging mechanism.
Can maintain good chargeability even if the charging member is contaminated
I found that. This is charged particles and toner and charging member
There is no doubt that it is due to the effect of increasing the number of contact points with
I think that the. Preferably 10 × 10^Fivecm²/ Cm³that's all
8 x 10⁶cm²/ Cm³More preferred by doing the following
Ku 1.2 × 10 ⁶cm²/ Cm³Above 4.0 × 10⁶Less than
The charging property and image characteristics are further improved by
It

[0200] Here, the specific surface area of the charged particles was determined as follows. First, according to the BET method, nitrogen gas was adsorbed on the surface of the material using a specific surface area measuring device “Gemini 2375 Ver. 5.0” (manufactured by Shimadzu Corporation), and BET was applied.
The BET specific surface area (cm ² / g) is calculated using the multipoint method.

Next, a dry-type automatic densitometer "Accupyc"
1330 "(manufactured by Shimadzu Corp.)
m ³ ) is calculated. At this time, using a 10 cm ³ sample container,
Helium gas purge was used as the sample pretreatment at a maximum pressure of 19.
Do 10 times at 5 psig. After that, as a pressure equilibrium judgment value of whether or not the pressure in the container has reached equilibrium, the pressure fluctuation in the sample chamber is set to 0.0050 / min as a guide. Start and automatically measure true density. The measurement is performed 5 times, and the average value thereof is calculated to obtain the true density.

Here, the specific surface area of the powder is obtained as follows.

Specific surface area (cm ² / cm ³ ) = BET specific surface area (cm ² / g) × true density (g / cm ³ ) Further, the charged particles have a volume-based median diameter D ₅₀ of 0.
The conductive fine particles are 4 μm or more and 4.0 μm or more.

Generally, the adhesive force due to the interaction between particles is stronger as the difference in particle size between particles is larger. One of the expected effects of the charged particles according to the present invention is the improvement of the triboelectrification characteristics due to contact with the toner. Therefore, the strong adhesion between the charged particles and the toner particles makes the operation difficult.
The toner has a mass average particle diameter of 3.0 μm to 12.0 μm, and an appropriate D ₅₀ of the charged particles is 0.4 μm or more. Charged particles having a D ₅₀ of less than 0.4 μm are difficult to separate from the toner particles and the triboelectric charging property cannot be expected to be improved, so that, for example, sufficient image density cannot be obtained.

On the other hand, when D ₅₀ is large, the interaction with the toner is weakened, and the effect of improving the triboelectrification characteristics is deteriorated. When the D _{50 of the} charged particles is equal to or more than the mass average particle diameter of the toner, the effect of interaction is hardly seen and, in addition, the movement of the toner under the developing electric field is rather hindered and the fog is deteriorated. , The resolution may be reduced. A more preferable D ₅₀ is 0.5 μm or more and 3.5 μm or less.

In this sense, the particle size distribution of charged particles
In the above, it is preferable that the number of fine particles is small. grain
As an index of the distribution on the fine powder side in the degree distribution,
Of D _TenCan be used and this D_TenAs 0.3μ
m or more is more preferable, and 0.4 μm or more is further preferable.
Yes. Similarly, the smaller the number of large particles, the better.
D as an index of distribution on the powder side₉₀Is used, D₉₀Is 4 μm
The following can be said to be more preferable.

Here, D ₁₀ , D ₅₀ and D ₉₀ of the charged particles are measured as follows. A laser diffraction particle size distribution measuring device "LS-230" (manufactured by Coulter, Inc.) was attached to a liquid module to set a particle size range of 0.04 to 2000 µm as a measurement range, and the particle size distribution of the obtained volume standard D ₁₀ of the particles, calculating a D ₅₀ and D _90. For measurement, add about 10 mg of particles to 10 ml of methanol and use an ultrasonic disperser to
After the dispersion for a minute, the measurement is performed under the condition that the measurement time is 90 seconds and the number of measurement is once.

Here, when measuring various physical properties of the charged particles contained in the toner, after printing a large number of sheets in a cleanerless system under the condition that there is no cleaning mode, the toner container is removed and the cleaner is attached. Printing is performed in the constant cleaning mode to collect the charged particles in the cleaner container and collect a sufficient amount before performing each measurement.

(6) The developing device 35a is a non-magnetic rotary developing sleeve as a developer carrying / conveying member which contains a magnet roll 35b therein.
The toner t in the pre-development mixture t + m provided in the developing container 35e is subjected to the layer thickness regulation and the charge application by the regulation blade 35c in the process of being conveyed on the rotary development sleeve 35a. A stirring member 35d circulates the toner in the developing container 35e and sequentially conveys the toner to the periphery of the sleeve.

The toner t coated on the rotary developing sleeve 35a is conveyed to the developing portion (developing area portion) a which is the opposing portion of the electrophotographic photosensitive member 31 and the sleeve 35a by the rotation of the sleeve 35a. A developing bias voltage is applied to the sleeve 35a from a developing bias applying power source S5.

In this example, the developing bias voltage was a superimposed voltage of DC voltage and AC voltage. As a result, the electrostatic latent image on the electrophotographic photosensitive member 31 side is reversely developed by the toner t.

A) Toner t: A one-component magnetic toner t, which is a developer, is prepared by mixing a binder resin, magnetic particles, and a charge control agent, kneading, pulverizing, and classifying, and further charging particles m. And a fluidizing agent are added as external additives. The average particle diameter (D4) of the toner was 8 μm.

(4) Charged Particle Carrying Amount and Coverage In this embodiment, since the toner recycling structure is used, a larger amount of toner contaminates the charging roller surface than in the conventional apparatus. The toner has a resistance value of 10 ¹³ Ω · cm or more in order to maintain electric charges due to frictional charging on the surface. Therefore, when the charging roller 32 is contaminated with the toner, the particle resistance carried on the charging roller 32 increases and the charging performance deteriorates. Even if the resistance of the charged particles is low, the resistance of the powder carried by the mixing of the toner rises and the charging property is impaired. Therefore, even if the amount of charged particles carried is 0.005 to 1 mg / cm ² / μm, preferably 0.02 to 0.3 mg / cm ² / μm in carried amount / Ra, a large amount of toner is contained in the component. In some cases, the charging performance is naturally lowered. In this case, the resistance of the supported particles increases, and the situation can be grasped. That is, in actual use, the resistance of the particles carried on the charging roller 32 (including the mixture of toner and paper powder) is measured by the above-mentioned method, and the value is 10 ⁻¹ to 10 ¹² Ω · cm. Is preferable, and more preferably 10 ⁻¹ to 10 ¹⁰ Ω · cm.

Furthermore, in order to grasp the effective amount of the charged particles m in charging, it is more important to adjust the coverage of the charged particles m. Since the charged particles m are white, they can be distinguished from the black color of the magnetic toner. The area showing white in observation with a microscope is obtained as an area ratio. When the coverage is 0.1 or less, the charging performance is insufficient even if the peripheral speed of the charging roller 32 is increased.
It is preferable to keep the coverage of the charged particles m in the range of 0.2 to 1.

The amount of carried particles was basically adjusted by adjusting the amount of charged particles m added to the developer t. Further, if necessary, an elastic blade was brought into contact with a part of the outer circumference of the charging roller 32 to perform the adjustment. By abutting the members, there is an effect of normalizing the triboelectrification polarity of the toner, and the amount of particles carried on the charging roller 32 can be adjusted.

[0216]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In addition, "part" in an Example shows a mass part.

(Example 1) Diameter 30 mm, longitudinal length 26
A solution prepared by dissolving 10 parts of a copolyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) on a 0 mm conductive substrate in a mixed solution of 60 parts of methanol / 40 parts of butanol, an aluminum cylinder having an outer diameter of 30 mm. It is applied by dip coating on the top and dried by heating at 90 ° C. for 10 minutes to give a film thickness of 0.
An undercoat layer of 5 μm was formed.

Next, a Bragg angle (2θ ± 0.2 °) of 9.0 ° in CuKα characteristic X-ray diffraction represented by the following formula:
And 4 parts of an oxytitanium phthalocyanine pigment having a strong peak at 27.1 °,

[0219]

[Chemical 28] Polyvinyl butyral resin (Product name: S-REC BX-
1, Sekisui Chemical Co., Ltd. 2 parts, cyclohexanone 7
A mixed solution of 0 parts was dispersed by a sand mill for 10 hours, and then 100 parts of ethyl acetate was added to prepare a charge generation layer coating liquid. This coating solution is dip-coated on the subbing layer prepared above and dried by heating at 90 ° C. for 10 minutes to give a film thickness of 0.
A 17 μm charge generation layer was formed.

Next, 7 parts of a triallylamine compound represented by the following formula:

[0221]

[Chemical 29] A solution prepared by dissolving 10 parts of polycarbonate (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) in 70 parts of chlorobenzene is dip-coated on the charge generation layer, and dried by heating at 110 ° C. for 60 minutes. Then, a charge transport layer having a film thickness of 20 μm was formed.

The protective layer was surface-treated with a compound represented by the following formula (treatment amount: 7%), 50 parts of ultrafine antimony-doped tin oxide particles,

[0223]

[Chemical 30] 150 parts of ethanol (boiling point 78 ° C.) was dispersed in a sand mill for 66 hours (average particle size 0.03 μ).
m). After that, resol type phenol resin (trade name: P
L-4804, manufactured by Gunei Chemical Industry Co., Ltd. as a resin component was dissolved in 30 parts to prepare a preparation liquid, and a film was formed on the above charge transport layer by a dip coating method. This electrophotographic photoreceptor is
Initial drying was performed at 0 ° C. for 2 minutes, and immediately thereafter, post-drying was performed at a temperature of 145 ° C. for 60 minutes with hot air to obtain an electrophotographic photosensitive member having a protective layer. The film thickness of the obtained electrophotographic photoreceptor is measured by
Instantaneous multi-photometry system MC due to light interference due to thin film
Measured using PD-2000 (manufactured by Otsuka Electronics Co., Ltd.),
The film thickness was 3 μm. The protective layer coating material was in a good dispersed state, and the produced protective layer was a uniform and uniform film.

Example 2 The phenol resin used in the coating material for the protective layer of the electrophotographic photosensitive member prepared in Example 1 was replaced with a resol type phenol resin (trade name: PL-4852,
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 1 except that drying was performed at 90 ° C. for 1 minute and then at 145 ° C. for 60 minutes instead of Gunei Chemical Industry Co., Ltd.

(Example 3) The phenol resin used in the coating material for the protective layer of the electrophotographic photosensitive member prepared in Example 1 was replaced with a resol type phenol resin (trade name: PR-5312).
3. Instead of Sumitomo Durres Co., Ltd., the solvent was replaced with a mixture of butanol (boiling point 118 ° C.) and ethanol (boiling point 78 ° C.) in a mass ratio of 9: 1, and the protective layer was dried at 10
Except for 1 minute at 0 ° C and then 60 minutes at 145 ° C,
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 1.

(Example 4) The resin for the protective layer prepared in Example 1 was a thermosetting melamine resin (trade name: Cymel C).
-370, Mitsui Cytec Co., Ltd., and an electrophotographic photosensitive member was produced in exactly the same manner as in Example 1 except that the initial drying temperature was 60 ° C. for 15 minutes.

(Example 5) An electrophotographic photosensitive member was prepared in exactly the same manner as in Example 4 except that the initial drying condition of the protective layer in the electrophotographic photosensitive member prepared in Example 4 was 90 ° C for 15 seconds. did.

(Example 6) An electrophotographic photoconductor was produced in exactly the same manner as in Example 5 except that the initial drying condition of the protective layer in the electrophotographic photoconductor produced in Example 5 was 100 ° C for 1 minute. did.

Example 7 An electrophotographic photoconductor was produced in exactly the same manner as in Example 5 except that the initial drying condition of the protective layer in the electrophotographic photoconductor produced in Example 5 was 55 ° C. for 1 minute. did.

Example 8 The protective layer in the electrophotographic photosensitive member produced in Example 7 was post-dried under conditions of 145 ° C. and 12
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was set to 0 minutes.

(Example 9) The conditions for post-drying the protective layer in the electrophotographic photosensitive member prepared in Example 5 were 145 ° C and 20.
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was changed.

(Example 10) The resin of the protective layer prepared in Example 1 was replaced with an epoxy resin in which Epicoat # 815 made by Yuka Shell and Epomate B002 were mixed in a ratio of 2: 1.
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 1 except that the initial drying conditions were 100 ° C. for 1 minute and the subsequent drying conditions were 160 ° C. for 60 minutes.

(Example 11) The same as Example 1 except that the resin for the protective layer prepared in Example 1 was replaced by the following composition and the initial drying temperature was the same as in Example 2. Then, an electrophotographic photosensitive member was produced.

As the coating material for the protective layer, 7 parts of the charge transporting material represented by Exemplified Compound 8 and 10 parts of the solution of the burette modified body represented by the following formula (solid content: 67% by mass) were added with ethanol 4
Dissolved in 0 parts.

[0235]

[Chemical 31]

Example 12 Acetone was used as the solvent used for the protective layer of the electrophotographic photosensitive member prepared in Example 11, and Exemplified Compound 17 was used as the charge transport material for the protective layer. The initial drying conditions were 80 ° C. An electrophotographic photosensitive member was produced in exactly the same manner as in Example 11 except that the time was set to 1 minute.

(Example 13) 70 parts of methanol was used as the solvent used for the protective layer of the electrophotographic photosensitive member prepared in Example 11.
Electrophotographic exposure was carried out in the same manner as in Example 11 except that 30 parts of methoxypropanol (boiling point 172 ° C.) was used, the charge transport material for the protective layer was exemplified compound 30, and the initial drying temperature was 70 ° C. for 20 seconds. The body was made.

(Examples 14 to 17) Example 1 was repeated except that the charge transporting materials for the protective layer of the electrophotographic photosensitive member 11 prepared in Example 11 were changed to Exemplified Compounds 2, 42, 49 and 56.
An electrophotographic photosensitive member was produced in exactly the same manner as in 1.

(Embodiment 18) Diameter 30 mm, longitudinal length 2
A solution of 10 parts of copolymerized nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) on a 60 mm conductive substrate in a mixed solution of 60 parts of methanol / 40 parts of butanol was placed on the aluminum cylinder. Dip coated, 90
It was heated and dried at 0 ° C. for 10 minutes to form a barrier layer having a film thickness of 0.5 (m.

The Bragg angle (2θ ± 0.2 °) of 7.4 ° and 2 in CuKα characteristic X-ray diffraction represented by the following formula:
2 parts of hydroxygallium phthalocyanine pigment having a strong peak at 8.2 °,

[0241]

[Chemical 32] Polyvinyl butyral resin (Product name: S-REC BX-
1, Sekisui Chemical Co., Ltd. 1 part, cyclohexanone 1
A mixed solution consisting of 20 parts was dispersed by a sand mill for 3 hours, and then 120 parts of ethyl acetate was added to prepare a charge generation layer coating liquid. This coating liquid was applied onto the undercoat layer prepared above by dip coating, and dried by heating at 60 ° C. for 20 seconds.

Next, 7 parts of a triarylamine compound represented by the following formula:

[0243]

[Chemical 33] A solution prepared by dissolving 10 parts of polycarbonate (trade name: Yupilon Z-400, manufactured by Mitsubishi Gas Chemical Co., Inc.) in 70 parts of chlorobenzene is dip-coated on the charge generation layer, and the solution is applied at 110 ° C. for 1 hour. It was heated and dried to form a charge transport layer having a film thickness of 20 μm.

As a protective layer, 20 parts of antimony-doped tin oxide ultrafine particles surface-treated with a compound represented by the following formula (treatment amount: 7%),

[0245]

[Chemical 34] Methyl hydrogen silicone oil (trade name: KF9
9, surface-treated with Shin-Etsu Silicone Co., Ltd. (20
%) Antimony-doped tin oxide fine particles 30 parts, ethanol 150 parts, methoxypropanol (boiling point 172 ° C.) 45
Part was dispersed in a sand mill for 66 hours, and further polytetrafluoroethylene fine particles (average particle size 0.18 μm)
20 parts was added and the mixture was dispersed for 2 hours. Then, 30 parts of a thermosetting resol type phenol resin (PL-4852, manufactured by Gunei Chemical Industry Co., Ltd.) was dissolved as a resin component to prepare a preparation liquid.

A film is formed on the charge transport layer by the dip coating method, dried with hot air at 60 ° C. for 20 seconds and then with hot air at 155 ° C. for 1 hour to form a protective layer having a thickness of 3 μm, and an electrophotographic image is formed. A photoconductor was obtained.

(Comparative Example 1) The initial drying condition of the protective layer in the electrophotographic photosensitive member prepared in Example 5 was 60 ° C and 20 ° C.
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was changed.

(Comparative Example 2) The initial drying conditions of the protective layer in the electrophotographic photosensitive member produced in Example 5 were 90 ° C and 15 ° C.
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was set to 2 seconds.

(Comparative Example 3) The initial drying conditions of the protective layer in the electrophotographic photosensitive member produced in Example 5 were 105 ° C and 1
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was changed.

Comparative Example 4 An electrophotographic photosensitive member was prepared in exactly the same manner as in Example 5 except that the initial drying condition of the protective layer in the electrophotographic photosensitive member prepared in Example 5 was 55 ° C. for 1 minute. It was made.

(Comparative Example 5) Electrophotographic sensitization was carried out in the same manner as in Example 5 except that the drying condition after the protective layer in the electrophotographic photosensitive member 5 produced in Example 5 was 145 ° C for 135 minutes. The body was made.

(Comparative Example 6) The drying conditions after the protective layer in the electrophotographic photosensitive member produced in Example 5 were 145 ° C and 1
An electrophotographic photosensitive member was produced in exactly the same manner as in Example 5 except that the time was 5 minutes.

(Comparative Example 7) An electrophotographic photoreceptor was prepared in the same manner as in Example 5 except that the initial drying condition of the protective layer in the electrophotographic photoreceptor prepared in Example 5 was 120 ° C for 60 minutes. Was produced.

(Comparative Example 8) An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 5 except that the initial drying temperature of the electrophotographic photoreceptor prepared in Example 5 was omitted.

(Comparative Example 9) The charge transporting material used in the electrophotographic photosensitive member prepared in Example 11 was changed to Exemplified Compound 2,
An electrophotographic photosensitive member was produced under the drying conditions according to Comparative Example 8.

<Evaluation 1> The obtained electrophotographic photosensitive member was mounted on a laser jet 4000 (manufactured by Hewlett-Packard Co.), and an initial image was evaluated (solid black).
An image was evaluated by continuously outputting 50,000 sheets. Further, the surface of the electrophotographic photosensitive member after continuous output was observed with a microscope to evaluate the scratches on the protective layer. The results are summarized in Tables 4 and 5. Further, in the method shown in Examples and Comparative Examples, the electrophotographic photosensitive member which was only subjected to initial drying was wiped with Kimwipes (manufactured by Tojo Kimberley) containing the solvent for the protective layer used. Although the protective layer of Example 3 was difficult to remove, the others were easily peeled off. The results are shown in Tables 4 and 5.

[0257]

[Table 4]

[0258]

[Table 5]

(Examples 19 to 36) Electrons were prepared in the same manner as in Examples 1 to 18 except that an electrophotographic photosensitive member was produced on a conductive support having a diameter of 24 mm and a longitudinal length of 246 mm. A photographic photoreceptor was produced.

Comparative Examples 10 to 18 Electrons were prepared in the same manner as in Comparative Examples 1 to 9 except that an electrophotographic photosensitive member was prepared on a conductive support having a diameter of 24 mm and a longitudinal length of 246 mm. A photographic photoreceptor was produced.

<Evaluation 2> The obtained electrophotographic photosensitive member was laser jet 1200 (manufactured by Hewlett-Packard Company).
Was mounted on a modified electrophotographic apparatus of the injection charging type shown in FIG. 3, and the same evaluation was performed except that the continuous printing durability test of Evaluation 1 was changed to 25,000 sheets. Examples 18 to 3
In 4, the charged particles have a volume resistivity of 10 ⁶ Ω · cm, a volume-based 10% average particle diameter (D ₁₀ ) 0.8 μm, a 50% average particle diameter (D ₅₀ ) 1.4 μm, and a 90% average particle. Diameter (D ₉₀ )
Conductive tin oxide having a surface area Ra (μm) of 2.32 μm and a specific surface area of 2.8 × 10 ⁶ cm ² / cm ³ was used, and the amount of particles carried on the charged particle support was determined by using the conductive tin oxide. An apparatus was used in which the value divided by was 0.1 mg / cm ² / μm. The results are shown in Table 6.

In Comparative Examples 10 to 18, the charged particles had a volume resistivity of 10 ⁶ Ω · cm, a volume-based 10% average particle diameter (D ₁₀ ) 1.6 μm, and a 50% average particle diameter (D ₅₀ ) 3. .1μ
m, 90% average particle size (D ₉₀ ) 4.2 μm, specific surface area 4 ×
Conductive tin oxide of 10 ⁵ cm ² / cm ³ was used, and the amount of the particles carried on the carrier was determined by the surface roughness R of the charged particle carrier.
An apparatus was used in which the value divided by a (μm) was 1.2 mg / cm ² / μm. The results are shown in Table 7.

[0263]

[Table 6]

[0264]

[Table 7]

As shown above, by conducting the drying in multiple stages, the conductive particles contained in the protective layer do not have high heat locally, and the conductive particles are peeled off in the continuous printing durability test. A good image can be output without dropping. Further, when the protective layer contains a charge transport material,
Since the surrounding resin for the protective layer does not solidify at once, an optimum arrangement can be taken and the charge transporting function can be sufficiently exerted, so that a good image can be output.

Further, if the initial drying is carried out within the boiling point of the solvent of ± 25 ° C., a good image can be always provided without occurrence of image defects such as black spot image and low density.

Furthermore, by setting the initial drying time to 15 seconds or more, the occurrence of image defects such as black spots and low density can be prevented, and by setting the initial drying temperature within 15 minutes, sufficient curing can be achieved. It is possible to provide a photoreceptor having excellent wear resistance.

When the initial drying time is more than 15 minutes, even if the initial drying temperature is close to the lower limit, if the drying time is too long, a small molecular weight such as a curing monomer contained in the resin of the protective layer is obtained. It was considered that the product of No. 1 migrated to the lower layer and the curability was lowered.
Further, if the post-drying is too long, a large amount of heat is applied to the electrophotographic photosensitive member, causing thermal deterioration of the photosensitive layer, and the sensitivity is deteriorated so that the bright part potential is increased and the contrast potential is sufficiently high. Is not obtained, and the concentration becomes low. On the other hand, if the drying temperature of the thermosetting reaction is too short,
The abrasion resistance of the protective layer is not sufficient, causing scratches on the photosensitive layer. In addition, as in Comparative Example 7, when the initial drying temperature was higher than the boiling point of the solvent + 25 ° C. and the thermosetting reaction of the thermosetting resin had begun (not wiped off with the solvent), once in the initial drying step, Since the curable resin has become active, it seems that even after the post-drying step, the resin has already been deactivated and sufficient curability cannot be obtained.

Further, in the case of the injection charging type process cartridge and electrophotographic apparatus of the present invention, which is a process that is more severe for the photoconductor, an image defect occurred at the early stage of the continuous printing durability test. When drying is performed under the conditions described in 1., a good image can be provided.

[0270]

As described above, according to the present invention,
By drying the protective layer under specific conditions, there is no peeling of the protective layer due to durability, excellent abrasion resistance, and an electrophotographic photosensitive member that also sufficiently satisfies electrophotographic characteristics, and a process cartridge or electrophotographic apparatus having the same. It has become possible to provide a device.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of 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 provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

FIG. 3 is a diagram showing a schematic configuration of an injection charging type image device having the electrophotographic photosensitive member of the present invention.

FIG. 4 is an explanatory diagram of a resistance value measuring method of a charging roller.

[Explanation of symbols]

1 protective layer 2 Charge transport layer 3 Charge generation layer 4 Conductive support 5 tie layer 6 Undercoat layer 11 Electrophotographic photoreceptor 12 axes 13 charging means 14 exposure light 15 Developing means 16 Transfer means 17 Transfer material 18 Fixing means 19 Cleaning means 20 Pre-exposure light 21 Process cartridge 22 Guide means 31 photosensitive drum 32 charging roller 32a core metal 32b conductive elastic roller 34 Laser exposure device 35 1-component magnetic developing device 36 Transfer charger 37 Fixing device m Charged conductive particles (charged particles)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/02 101 G03G 15/02 101 21/18 15/00 556 (72) Inventor Koichi Nakata Ota, Tokyo 3-30-2 Shimomaruko-ku, Canon Inc. (72) Inventor Tatsuya Ikematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo In-house Canon Inc. (72) Yosuke Morikawa 3-chome, Shimomaruko, Ota-ku, Tokyo No. 30 No. 2 Canon F-term (Reference) 2H068 AA03 AA04 AA05 AA06 BA12 BA58 BA61 BB29 BB30 BB31 BB33 BB34 BB35 BB37 CA06 CA21 CA32 CA33 CA37 CA44 CA46 CA48 CA49 EA14 EA19 FA27 FC01 2H171 FA02 FA06 GA25 JA02 JA23 JA38 JA40 QA02 QA08 QA11 QA15 QA16 QB03 QB09 QB15 QB32 QC03 QC11 QC22 QC23 TA08 TA15 TB02 TB12 TB13 TB14 2H200 FA02 FA09 GA14 GA16 GA23 GA34 G B12 HA03 HA28 HB12 HB17 HB22 HB45 HB46 HB47 MA01 MA03 MA08 MA14 MA17 MA20 MB01 MB04 MC01 MC06 MC15

Claims (39)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, wherein the protective layer is conductive particles,
At least one of the charge transport materials and a thermosetting resin are contained, and the protective layer is formed through a multi-step drying temperature in the drying process after coating, and the initial drying temperature (A ° C.) is the coating composition of the protective layer. An electron characterized in that the boiling point of the solvent used is within ± 25 ° C., the initial drying time is 15 seconds or more and 15 minutes or less, and the total time of multistage drying excluding the initial drying time is 20 minutes or more and 120 minutes or less. Photoreceptor. 2. The electrophotographic photosensitive member according to claim 1, wherein the initial drying temperature (A ° C.) is lower than the curing start temperature of the thermosetting resin. 3. The relationship between the initial drying temperature (A ° C.) and the final drying temperature of multi-stage drying (B ° C.) satisfies A <B.
Or the electrophotographic photosensitive member according to item 2. 4. The electrophotographic photosensitive member according to claim 1, wherein the thermosetting resin is at least one kind of melamine resin, phenol resin, epoxy resin and isocyanate resin. 5. The electrophotographic photosensitive member according to claim 4, wherein the thermosetting resin is a phenol resin. 6. The electrophotographic photosensitive member according to claim 5, wherein the phenol resin is a resol type phenol resin. 7. The electrophotographic photosensitive member according to claim 1, wherein the conductive particles are metal or metal oxide particles. 8. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains at least one of a fluorine atom-containing compound and a siloxane compound. 9. The protective layer contains lubricating particles.
9. The electrophotographic photosensitive member according to any one of to 8. 10. The electrophotographic photosensitive member according to claim 9, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicone resin particles, silica particles and alumina particles. 11. The electrophotographic photoreceptor according to claim 8, wherein the fluorine atom-containing compound is selected from the group consisting of a fluorine-containing silane coupling agent, a fluorine-modified silicone oil and a fluorine-based surfactant. 12. The electrophotographic photosensitive member according to claim 8, wherein the siloxane compound is a siloxane compound represented by the formula (I). [Chemical 1] (In the formula, A is a hydrogen atom or a methyl group, and the proportion of hydrogen atoms in all A is in the range of 0.1 to 50%,
(n is a positive integer of 0 or more) 13. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting material used for the protective layer has at least one hydroxyl group in the molecule. 14. The charge transport material used for the protective layer is
The electrophotographic photoreceptor according to claim 13, which has at least one hydroxyalkyl group, hydroxyalkoxy group, and optionally substituted hydroxyphenyl group in the molecule. 15. A hydroxyalkyl group, hydroxya
Hydroxypheni which may have a lucoxy group and a substituent
Group having at least one substituent selected from the group
The material to be sent is represented by any of the following formulas (1) to (6)
The electrophotography according to any one of claims 1 to 14,
Photoconductor. [Chemical 2] (In the formula, R₁, R₂And R₃Are branches each having 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be separated, and includes α, β and
γ has a halogen atom as a substituent and a substituent, respectively.
Optionally substituted alkyl group, optionally substituted alkoxy
A group, an aryl group which may have a substituent or a substituent
A benzene ring which may have one or more heterocyclic groups
Where a, b and d are 0 or 1 and m and n are 0 or
Is 1) [Chemical 3] (In the formula, R_Four, R_FiveAnd R₆Are branches each having 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be separated, and δ and ε are
Even if each has a halogen atom as a substituent or a substituent
A good alkyl group, an alkoxy group which may have a substituent,
Optionally substituted aryl group or optionally substituted
Shows a benzene ring which may have one or more good heterocyclic groups.
However, e, f and g are 0 or 1. p, q and r are 0
Or, they are 1 and all cannot be 0 at the same time. Z₁
And Z₂May each have a halogen atom or a substituent.
Alkyl group, optionally substituted alkoxy group,
It may have an aryl group or a substituent.
A heterocyclic group, which may form a ring together) [Chemical 4] (In the formula, R₇, R₈, R₉And R_TenEach has 1 to 1 carbon atoms
8 represents a divalent hydrocarbon group which may be branched,
η, θ and ι are each a halogen atom or a substituent
Alkyl group which may have a substituent, which may have a substituent
An alkoxy group, an aryl group which may have a substituent or a group
A group which may have one or more heterocyclic groups which may have a substituent
Represents a Nzen ring, h, i, j and k are 0 or 1,
s, t and u are 0 or 1. Z₃And Z_FourAre each
Halogen atom, optionally substituted alkyl group, substituted
Alkoxy group which may have a group, which may have a substituent
Represents a heterocyclic group which may have an aryl group or a substituent,
You may form a circle jointly) [Chemical 5] (In the formula, R₁₁Is divalent with 1 to 8 carbon atoms and may be branched
Represents a hydrocarbon group of R, ₁₂Has a hydrogen atom and a substituent
Aralkyl group which may have a substituent or aralkyl group which may have a substituent
Alternatively, it represents a phenyl group which may have a substituent. Ar₁Over
And Ar₂Is an alkyl group which may have a substituent, a substituent
Aralkyl groups that may have and ants that may have a substituent
Group or a heterocyclic group which may have a substituent. Ar
₃Is an arylene group which may have a substituent or a divalent substituent
A heterocyclic group which may have a group is shown. v and w are respectively
It is 0 or 1. However, when v = 0, w = 0.
κ and λ are a halogen atom and a substituent, respectively.
An alkyl group which may have an alkyl group which may have a substituent
Coxy group, aryl group which may have a substituent or substituent
Benzene which may have one or more heterocyclic groups which may have
Ring) [Chemical 6] (In the formula, R₁₃Is divalent with 1 to 8 carbon atoms and may be branched
Shows a hydrocarbon group of. Ar_FourAnd Ar_FiveHas a substituent
Aralkyl, optionally substituted aralkyl
A group, an aryl group which may have a substituent or a substituent
Represents a heterocyclic group which may be present. μ and ν are the substituents
A halogen atom, an alkyl group which may have a substituent,
An alkoxy group which may have a substituent or a substituent which may have a substituent
1 is a heterocyclic group which may have a good aryl group or a substituent.
One or more benzene rings are shown. Note that μ and ν are
You may form a ring jointly via a substituent. x is 0 or 1
Is) [Chemical 7] (In the formula, R₁₄And R₁₅Are each branched with 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be added. Ar₆Is a substituent
An alkyl group which may have a substituent or an alkyl group which may have a substituent
Alkyl group, optionally substituted aryl group or substituent
Represents a heterocyclic group which may have. ξ, π, ρ and σ are
Each may have a halogen atom or a substituent as a substituent.
Alkyl group, optionally substituted alkoxy group,
It may have an aryl group or a substituent.
Represents a benzene ring which may have one or more heterocyclic groups.
Note that ξ and π and ρ and σ form a ring jointly via a substituent.
You may. y and z are 0 or 1 respectively) 16. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is charged by a charging unit, and the electrophotographic photosensitive member on which an electrostatic latent image is formed is developed with toner. Integrally supporting with at least one means selected from the group consisting of a developing means and a cleaning means for collecting the toner remaining on the electrophotographic photosensitive member after the transfer step,
A process cartridge characterized by being detachable from the main body of the electrophotographic apparatus. 17. Charged particles containing conductive particles as a main component,
It has a conductive and elastic surface and is composed of a charged particle carrier that carries the charged particles, and the charged particles are detachable from the main body of the electrophotographic apparatus having a charging device that contacts and charges the electrophotographic photosensitive member. In the process cartridge of 1., the charged particles have a volume resistivity of 1 × 10 ⁹ Ωcm or less and a specific surface area of 5 × 10 ⁵ cm ² / cm ³ or more and 1 × 10 ⁷ cm ²
/ Cm ³ or less, and the volume-based median diameter D ₅₀ is 0.4 μm or more and 4.0 μm.
The value obtained by dividing the amount of the particles carried on the carrier by the surface roughness Ra (μm) of the charged particle carrier is 0.005 to 1 mg.
/ Cm ² / μm, the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 15. 18. When the ratio of the conductive particles coating the charged particle carrier is defined as the coverage Rc, 0.2 ≦ Rc
The process cartridge according to claim 17, wherein ≦ 1. 19. The surface resistance of the charging particle carrying member 10 ⁴
The process cartridge according to claim 17 or 18, wherein the process cartridge has a resistance of -10 ¹⁰ Ω □. 20. The process cartridge according to any one of claims 17 to 19, wherein the charged particle carrier is an elastic body having a porous body surface. 21. The volume resistivity is 10 ⁻¹ to 10 ⁹ Ω · cm.
17. The charged particle supply means for supplying the particles to the surface of the charged particle carrier, comprising:
0. The process cartridge according to 0. 22. The volume-based median diameter D of the charged particles
₅₀ is 0.4 μm or more and 3.5 μm or less.
21. The process cartridge according to any one of 21. 23. The volume-based D _{90 of the} charged particles is 4 μm.
The process cartridge according to any one of claims 17 to 22, which is as follows. 24. The volume-based D _{10 of the} charged particles is 0.3.
The process cartridge according to any one of claims 17 to 23, which has a size of not less than μm. 25. The volume-based D _{10 of the} charged particles is 0.4.
The process cartridge according to claim 24, wherein the process cartridge has a size of not less than μm. 26. The specific surface area of the charged particles is 1.0 × 10.
The process cartridge according to any one of claims 17 to 25, which has a density of ⁶ cm ² / cm ³ or more and 8.0 × 10 ⁶ cm ² / cm ³ or less. 27. The specific surface area of the charged particles is 1.2 × 10.
27. The process cartridge according to claim 26, which has a density of ⁶ cm ² / cm ³ or more and 4.0 × 10 ⁶ cm ² / cm ³ or less. 28. The electrophotographic photosensitive member according to claim 1, a charging unit that charges the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member is exposed to form an electrostatic latent image. An electrophotographic apparatus comprising an exposing means, a developing means for developing with a toner on an electrophotographic photosensitive member on which an electrostatic latent image is formed, and a transferring means for transferring a toner image on the electrophotographic photosensitive member onto a transfer material. . 29. Charged particles containing conductive particles as a main component,
An electrophotographic apparatus comprising a charging device having a conductive and elastic surface and carrying the charged particles, wherein the charged particles contact with an electrophotographic photosensitive member to be charged, The charged particles have a volume resistivity of 1 × 10 ⁹ Ωcm or less and a specific surface area of 5 × 10 ⁵ cm ² / cm ³ or more and 1 × 10 ⁷ cm ^2.
/ Cm ³ or less, and the volume-based median diameter D ₅₀ is 0.4 μm or more and 4.0 μm.
The value obtained by dividing the amount of the particles carried on the carrier by the surface roughness Ra (μm) of the charged particle carrier is 0.005 to 1 mg.
/ Cm ² / μm, the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 16. 30. When the ratio of the conductive particles coating the charged particle carrier is defined as the coverage Rc, 0.2 ≦ Rc
The electrophotographic apparatus according to claim 29, wherein ≦ 1. 31. The surface resistance of the charging particle carrying member 10 ⁴
To 10 ¹⁰ Omega claim 29 or 3, characterized in that a □
The electrophotographic apparatus according to item 0. 32. The electrophotographic apparatus according to claim 29, wherein the charged particle carrier is an elastic body having a porous body surface. 33. The volume resistivity is 10 ⁻¹ to 10 ⁹ Ω · cm.
The charged particle supply means for supplying the particles to the surface of the charged particle carrier, comprising:
2. The electrophotographic apparatus according to any one of 2. 34. The volume-based median diameter D of the charged particles.
₅₀ is 0.4 μm or more and 3.5 μm or less.
33. The electrophotographic apparatus according to any one of 33. 35. The volume-based D _{90 of the} charged particles is 4 μm.
The electrophotographic apparatus according to claim 29, which is as follows. 36. The volume-based D _{10 of the} charged particles is 0.3.
The electrophotographic apparatus according to any one of claims 29 to 35, having a thickness of at least μm. 37. The volume-based D _{10 of the} charged particles is 0.4.
The electrophotographic apparatus according to claim 36, wherein the electrophotographic apparatus has a thickness of at least μm. 38. The specific surface area of the charged particles is 1.0 × 10.
38. The electrophotographic apparatus according to claim 29, which has a density of ⁶ cm ² / cm ³ or more and 8.0 × 10 ⁶ cm ² / cm ³ or less. 39. The specific surface area of the charged particles is 1.2 × 10.
39. The electrophotographic apparatus according to claim 38, having a size of ⁶ cm ² / cm ³ or more and 4.0 × 10 ⁶ cm ² / cm ³ or less.