JPH10293454A - Developer carrier, developing device, developing method, image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and appropriately electrify toner on the surface of a developer carrier by making a coating layer contain binding resin, conductive spherical particles dispersed in the binding resin and having specified number average particle size and true density and nitrogen-containing heterocyclic compound. SOLUTION: A developing sleeve 8 has at least a base substance 6 and the coating layer 7 with which the base substance 6 is coated, the layer 7 contains the binding resin, the conductive spherical particles which are dispersed in the binding resin and whose number average particle size is 0.3 to 30 μm and whose true density is <=3 g/cm<3> and the nitrogen-containing heterocyclic compound. Therefore, uniform surface particle size is held on the surface of the layer 7 of the sleeve 8 and simultaneously toner contamination and toner fusion are hardly caused even when the surface of the layer 7 is worn. By the mutual action with the nitrogen-containing heterocyclic compound contained in the conductive coating layer, the conductive spherical particles enhance the effect of the charge control of the nitrogen-containing heterocyclic compound further, and rapid and uniform electrification is more improved and further electrifying performance is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing an electrostatic latent image formed on a latent image holding member such as an electrophotographic photosensitive member or an electrostatic recording dielectric in an electrophotographic process to visualize the latent image. The present invention relates to a developer carrier used, a developing device using the developer carrier, a developing method, an image forming apparatus, and a process cartridge.

[0002]

2. Description of the Related Art Conventionally, for example, a developing device which visualizes an electrostatic latent image formed on the surface of a photosensitive drum as an electrostatic latent image holding member by a magnetic toner which is a one-component developer has been used.
An apparatus as shown in FIG. 6 is known. In FIG.
The developer container 53 holds a magnetic toner 54 as a one-component developer. The developer container 53 holds a magnetic toner 54 due to mutual particle friction between the magnetic toners and friction between the developing sleeve 58 as a developer carrier and the magnetic toner particles. A charge having a polarity opposite to the electrostatic latent image charge formed on the photosensitive drum 51 and a development reference potential is applied to the magnetic toner particles, and the magnetic toner is applied to the developing sleeve 58 extremely thinly by the magnetic blade 52. In the developing region D in which the photosensitive drum 51 and the developing sleeve 58 are carried and the photosensitive drum 51 are opposed to each other, the magnetic toner carried by the magnet 55 fixed in the developing sleeve 58 causes the carried magnetic toner to fly and Is known which visualizes the electrostatic latent image of the above. A and B indicate the respective rotation directions of the developing sleeve 58 and the photosensitive drum 51, 59 indicates a developing bias means for applying a developing bias voltage during development, and 60 indicates a magnetic toner in the developer container 53. It is a stirring blade for stirring 54.

However, when such a one-component developer is used, it is difficult to adjust the toner charge, and although various measures have been taken with the developer, the non-uniformity of the toner charge and the durability stability of the charge have been attempted. The problem with has not been completely solved.

In particular, as the developing sleeve rotates repeatedly, the charge amount of the toner coated on the developing sleeve becomes too high due to the contact with the developing sleeve, and the toner is reflected by the mirror surface with the developing sleeve surface. As a result, a stationary state is formed on the surface of the developing sleeve, and a so-called charge-up phenomenon, which does not move from the developing sleeve to the latent image on the electrostatic latent image holding member (drum), is likely to occur. When such charge-up occurs, the toner in the upper layer becomes difficult to be charged, and the amount of development of the toner is reduced, which causes problems such as thinning of a line image and low image density of a solid image.

Further, since the toner layer forming state of the image area (toner consuming section) and the non-image area change and the charging state changes, for example, the position where a solid image having a high image density is once developed is located at the developing sleeve. When a halftone image is developed at the development position during the next rotation of the image, a phenomenon in which a solid image appears on the image, that is, a so-called sleeve ghost phenomenon is likely to occur.

[0006] In recent years, in order to improve the quality of electrophotography, the particle size and the particle size of toner have been reduced. For example, in order to improve image quality such as resolution and sharpness and to faithfully reproduce an electrostatic latent image, the weight average particle size of the toner is about 6 to
In general, those having a thickness of 9 μm are used. Further, there is a tendency that the fixing temperature of the toner is lowered for the purpose of shortening the first copy time and reducing the power consumption. Under such circumstances, the toner is more likely to electrostatically adhere to the developing sleeve, and the external surface is subjected to a physical force, so that contamination of the sleeve surface and fusion of the toner are likely to occur. I have.

As a method for solving such a phenomenon, a developing sleeve in which a coating layer in which a conductive lubricant such as a solid lubricant and carbon is dispersed in a resin is provided on a metal substrate is used in a developing device. Suggestions for methods have been made. It is recognized that the use of this method greatly reduces the above-mentioned phenomenon. However, in this method,
Since the shape of the surface of the developing sleeve is not sufficiently uniform and the frictional charge applied portion on the surface of the developing sleeve is also reduced, the uniform charging of the toner and the rise of the charging of the toner may be insufficient. Therefore, the character line image may be scattered, or the image density in a high-temperature, high-humidity environment may be low, which is not yet satisfactory. Further, the above-mentioned method is insufficient in terms of durability due to embrittlement of the coating layer.

Japanese Patent Application Laid-Open No. 3-200986 discloses a developing device in which a conductive coating layer in which a conductive fine powder such as a solid lubricant and carbon and spherical particles are further dispersed in a resin is provided on a metal substrate. There has been a proposal for a method to be used. By using this method, the shape of the surface of the developing sleeve is made uniform, and the uniformity of charging and the abrasion resistance are improved. However, even in this developing sleeve, the ability to quickly and uniformly charge the toner, improve the abrasion resistance of the conductive coating layer, and improve durability performance such as control of toner contamination and toner fusion when abrasion occurs. Further improvements are desired.

Japanese Patent Application Laid-Open No. Hei 2-176762 discloses a developing device in which a charge controlling agent is contained in a coating layer on the surface of a developing sleeve in order to improve the rise of charging of the toner and to further uniformly charge the toner. There has been a proposal for a method to be used. By using this method, the rise of toner charge and the uniform charging of the toner are improved to some extent, but they still exert sufficient effects on high image quality with excellent character sharpness and image density stability under high temperature and high humidity. The ability of the surface of the developing sleeve to provide charge is insufficient. Furthermore, the durability is still not satisfactory, and further improvement is desired.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent the conductive coating layer on the surface of the developer carrier from being deteriorated due to repeated copying or durability, to have high durability and to obtain stable image quality. An object of the present invention is to provide a developer carrier, a developing device having the developer carrier, a developing method, an image forming apparatus, and a process cartridge.

It is an object of the present invention to provide an image processing apparatus which is free from problems such as density reduction, sleeve ghost and fog, has good character line sharpness, and has high image density even under different environmental conditions for a long period of time. An object of the present invention is to provide a developer carrier capable of stably obtaining a high-quality image, a developing device having the developer carrier, a developing method, an image forming apparatus, and a process cartridge.

An object of the present invention is to control non-uniform charging of a toner on the surface of a developer carrying member, which appears when a toner having a small particle diameter is used, and to quickly and properly charge the toner. An object of the present invention is to provide a developer carrier, a developing device having the developer carrier, a developing method, an image forming apparatus, and a process cartridge.

[0013]

The above object is achieved by the following constitution of the present invention.

According to the present invention, there is provided a developer carrier having at least a substrate and a coating layer covering the substrate, wherein the coating layer comprises a binder resin and a number average particle diameter of 0 dispersed in the binder resin. A developer carrier comprising at least conductive spherical particles having a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound.

The present invention provides a developer container for storing a developer,
And carrying the developer contained in the developer container,
And a developing device having a developer carrier for transporting the developer to a development area, wherein the developer carrier has at least a substrate and a coating layer covering the substrate, and the coating layer Contains at least a binder resin, conductive spherical particles having a number average particle diameter of 0.3 to 30 μm, a true density of 3 g / cm ³ or less, and a nitrogen-containing heterocyclic compound dispersed in the binder resin. And a developing device.

According to the present invention, there is provided a step of supporting a developer accommodated in a developer container on a developer carrier; and allowing the developer carried on the developer carrier to electrostatically contact the developer carrier. Conveying the latent image holding member to a developing area facing the latent image holding member; an electrostatic latent image formed on the electrostatic latent image holding member by the developer carried on the developer holding member in the developing area; Developing the image, wherein the developer carrier has at least a substrate and a coating layer covering the substrate, and the coating layer is a binder resin, the binder resin Number average particle diameter 0.3 to 30 μm, true density 3 g dispersed therein
The present invention relates to a developing method comprising at least conductive spherical particles of at most / cm ³ and a nitrogen-containing heterocyclic compound.

According to the present invention, (i) an electrostatic latent image holding member for holding an electrostatic latent image, and (ii) the electrostatic latent image is developed with a developer in a developing area to form a developed image. An image forming apparatus having at least a developing unit for developing, a developing container for storing a developer, a developer contained in the developer container, and a developing area. A developer carrier for transporting the developer to the substrate, the developer carrier having at least a substrate and a coating layer covering the substrate, the coating layer comprising a binder resin, Number average particle size 0.3 to 3 dispersed in binder resin
The present invention relates to an image forming apparatus characterized by containing at least conductive spherical particles having a diameter of 0 μm and a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound.

According to the present invention, there is provided a process cartridge detachable from an image forming apparatus main body, the process cartridge comprising: (i) an electrostatic latent image holder for holding an electrostatic latent image; and (ii) the electrostatic latent image holder. Developing means for developing a latent image with a developer in a developing area to form a developed image, the developing means comprising at least an integrated developer container, a developer container for storing the developer, and the developer container It has a developer carrier for carrying the developer contained therein, and for transporting the developer to the development area, and the developer carrier covers at least the substrate and the substrate. The coating layer comprises a binder resin, a number average particle size of 0.3 to 30 μm dispersed in the binder resin, and a true density of 3 g / cm ^3.
The present invention relates to a process cartridge containing at least the following conductive spherical particles and a nitrogen-containing heterocyclic compound.

The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, added a coating layer on the surface of the developer carrier to specific conductive spherical particles having irregularities, and added a nitrogen-containing heterocyclic compound agent. The coexistence in the binder resin has the effect of rapidly and uniformly charging the developer, and has the effect of significantly improving the durability of the charging performance as compared with those conventionally used. I found it.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail with reference to preferred embodiments.

The conductive spherical particles used for the coating layer coated on the surface of the substrate constituting the developer carrier of the present invention will be described.

The conductive spherical particles used in the present invention have a number average particle diameter of 0.3 to 30 μm, preferably 2 to 30 μm.
Preferably, it is 20 μm and the true density satisfies ³ g / cm ³ or less.

The conductive spherical particles maintain uniform surface roughness on the surface of the coating layer of the developer carrier, and at the same time, have a small change in the surface roughness of the coating layer even when the surface of the coating layer is worn. It is added to make it difficult for toner contamination and toner fusion to occur.

The conductive spherical particles further enhance the effect of controlling the charge of the nitrogen-containing heterocyclic compound by interaction with the nitrogen-containing heterocyclic compound contained in the conductive coating layer, and provide a quick and uniform charge. It also has the effect of improving and stabilizing the charging performance.

The number average particle diameter of the conductive spherical particles is 0.3 μm.
If less than m, the effect of imparting uniform roughness to the surface of the coating layer and the effect of improving the charging performance are small, and the rapid and uniform charging of the developer becomes insufficient, and the toner is charged up due to wear of the coating layer. In addition, toner contamination and toner fusion occur, which tends to cause deterioration of sharpness and ghost of a character line of an obtained image and a decrease in image density. When the number average particle diameter exceeds 30 μm, the surface roughness of the coating layer becomes too large, and it becomes difficult to sufficiently charge the toner, and the mechanical strength of the coating layer is reduced. Absent.

True density of the conductive spherical particles used in the [0026] present invention, 3 g / cm ³ or less, preferably 2.7 g / cm ³ or less, and more preferably are from 0.9~2.3g / cm ³ good. When the true density of the conductive spherical particles exceeds ³ g / cm ³ , the dispersibility of the spherical particles in the conductive coating layer becomes insufficient, so that it is difficult to impart uniform roughness to the surface of the coating layer. At the same time, the nitrogen-containing heterocyclic compound is not uniformly dispersed, and the toner is rapidly and uniformly charged and the strength of the coating layer is insufficient, which is not preferable. When the true density of the conductive spherical particles is too low, the dispersibility of the spherical particles in the conductive coating layer becomes insufficient, which is not preferable.

In the present invention, as the conductivity of the conductive spherical particles, particles having a volume resistance of 10 ⁶ Ω · cm or less, preferably particles having a volume resistance of 10 ³ to 10 ^-6 Ω · cm are used. I do.

In the present invention, when the volume resistivity of the conductive spherical particles exceeds 10 ⁶ Ω · cm, the toner tends to be contaminated or fused with the spherical particles exposed on the surface of the conductive coating layer due to abrasion as nuclei. At the same time, it is difficult to perform quick and uniform charging, which is not preferable.

In the present invention, the term “spherical” in the conductive spherical particles means that the ratio of the major axis / minor axis of the particles is 1.0 to 1.5, and preferably the ratio of the major axis / minor axis is 1.
It is preferred to use particles from 0 to 1.2.

The ratio of the major axis / minor axis of the conductive spherical particles is 1.5
When it exceeds, the dispersibility of the conductive spherical particles in the conductive coating layer is reduced, the dispersibility of the nitrogen-containing heterocyclic compound in the conductive coating layer is reduced, and the surface roughness of the coating layer is not uniform. This is undesirable in terms of quick and uniform charging of the toner and strength of the conductive coating layer.

As a method for obtaining the conductive spherical particles of the present invention, the following methods are preferred, but are not necessarily limited to these methods.

A particularly preferred method for obtaining conductive spherical particles used in the present invention is, for example, a low-density and good graphite obtained by firing resin-based spherical particles or mesocarbon microbeads to carbonize and / or graphitize. A method of obtaining conductive spherical carbon particles may be used. Examples of the resin used for the resin-based spherical particles include phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, and polyacrylonitrile.

The mesocarbon microbeads can be usually produced by washing a spherical crystal produced in the process of heating and firing a medium pitch with a large amount of a solvent such as tar, medium oil and quinoline.

As a more preferable method for obtaining conductive spherical particles, a spherical resin particle surface such as a phenol resin, a naphthalene resin, a furan resin, a xylene resin, a divinylbenzene polymer, a styrene-divinylbenzene copolymer, and a polyacrylonitrile is used. The bulk mesophase pitch is coated by the mechanochemical method, and the coated particles are heat-treated in an oxidizing atmosphere, and then fired in an inert atmosphere or vacuum to be carbonized and / or graphitized, and the inside is carbonized. A method for obtaining graphitized conductive spherical carbon particles may be used. Spherical carbon particles obtained by this method are more preferable because, when they are graphitized, the coating of the obtained spherical carbon particles has advanced crystallization, so that the conductivity is improved.

The conductive spherical carbon particles obtained by the above method can control the conductivity of the obtained spherical carbon particles by changing the firing conditions in any method. It is preferably used.
In some cases, the spherical carbon particles obtained by the above-described method may include a conductive metal and / or a conductive metal particle having a true density not exceeding ³ g / cm ³ in order to further increase the conductivity.
Alternatively, metal oxide plating may be performed.

As another method for obtaining the conductive spherical particles used in the present invention, the conductive fine particles having a particle diameter smaller than the particle diameter of the core particles are appropriately added to the core particles composed of the spherical resin particles. After the conductive fine particles are uniformly attached around the core particles by the action of van der Waals force and electrostatic force by mechanical mixing, a local temperature rise caused by, for example, applying a mechanical impact force A method of softening the surface of the core particles, forming conductive fine particles on the surface of the core particles, and obtaining conductive resin-treated spherical resin particles.

As the core particles, it is preferable to use spherical resin particles made of an organic compound and having a low true density. Examples of the resin include PMMA, acrylic resin, and the like.
Polybutadiene resin, polystyrene resin, polyethylene, polypropylene, polybutadiene, or a copolymer thereof, benzoguanamine resin, phenol resin, polyamide resin, nylon, fluorine resin, silicone resin, epoxy resin, and polyester resin are exemplified.

As the conductive fine particles (small particles) to be adhered to the surface of the core particles (base particles), the particle size of the small particles is ８ of the particle size of the base particles in order to uniformly provide a conductive fine particle coating. It is preferred to use:

Still another method for obtaining the conductive spherical particles used in the present invention is to uniformly disperse the conductive fine particles in the spherical resin particles, thereby obtaining the conductive spherical particles in which the conductive fine particles are dispersed. There is a method of obtaining. As a method of uniformly dispersing the conductive fine particles in the spherical resin particles, for example, after kneading the binder resin and the conductive fine particles to disperse the conductive fine particles, solidify by cooling, and pulverize to a predetermined particle size A method of obtaining conductive spherical particles by mechanical and thermal treatments to obtain conductive spherical particles; or adding a polymerization initiator, conductive fine particles and other additives to a polymerizable monomer, and uniformly dispersing with a dispersing machine. The dispersed monomer composition is suspended in an aqueous phase containing a dispersion stabilizer so as to have a predetermined particle size by a stirrer or the like and polymerized to obtain spherical particles in which conductive fine particles are dispersed. Method.

The conductive spherical particles in which the conductive fine particles obtained by these methods are dispersed are also mechanically mixed with the conductive fine particles having a particle size smaller than the above-mentioned core particles at an appropriate blending ratio, and the van der After the conductive fine particles are uniformly attached around the conductive spherical particles by the action of the Waals force and the electrostatic force, for example, the surface of the conductive spherical particles is caused by a local temperature rise caused by applying a mechanical impact force. May be softened, and conductive fine particles may be formed on the surface to further increase the conductivity.

The structure of the coating layer of the developer carrier of the present invention is such that the binder resin of the coating layer contains a nitrogen-containing heterocyclic compound in combination with the conductive spherical particles so that the coating layer is charged. The performance is significantly improved, and the object of the present invention is achieved.

That is, when the nitrogen-containing heterocyclic compound is contained in the binder resin of the coating layer in combination with the conductive spherical particles,
The interaction between the compound having a nitrogen-containing heterocyclic structure and the conductive spherical particles facilitates the uniform dispersion of the nitrogen-containing heterocyclic compound in the coating layer, and the conductive spherical particles are further dispersed in the binder resin in the coating layer. The presence of the toner makes it difficult for the toner having a high charge amount to adhere to the binder resin surface of the coating layer.
It is possible to effectively exhibit the charge control property of the nitrogen-containing heterocyclic compound. Thus, the use of the developer carrier having the coating layer of the present invention makes it possible to quickly and uniformly charge the toner, and to provide an image having good character line sharpness and high image density even under different environmental conditions. It can be obtained stably.

Furthermore, the uniform unevenness of the surface of the coating layer provided by the conductive spherical particles further promotes uniform charging of the toner, and further reduces toner contamination and toner fusion by the effect of the conductive spherical particles. It hardly occurs on the surface of the coating layer, and the charge controllability of the coating layer due to the nitrogen-containing heterocyclic compound is also improved in terms of durability. Thus, when the developer carrying member having the coating layer of the present invention is used, the deterioration of the surface of the developer carrying member due to repeated copying or durability is unlikely to occur. It is possible to stably obtain a high-quality image having a high image density without causing problems such as fogging, having good character line sharpness.

The above-mentioned nitrogen-containing heterocyclic compound has a number average particle diameter of preferably 20 μm or less, more preferably 0.1 to 10 μm.
It is preferable to use one having a size of 15 μm. When the number average particle diameter of the nitrogen-containing heterocyclic compound exceeds 20 μm, it is difficult to sufficiently obtain the effect of improving the charging performance due to poor dispersibility of the nitrogen-containing heterocyclic compound in the coating layer, which is not preferable.

Examples of the nitrogen-containing heterocyclic compound used in the present invention include imidazole, imidalin, imidazolone, pyrazoline, pyrazole, pyrazolone, oxazoline, oxazole, oxazolone, thiazoline, thiazole, and the like.
Thiazolone, selenazoline, selenazole, selenazolone, oxadiazole, thiadiazole, tetrazole, benzimidazole, benzotriazole, benzoxazole, benzothiazole, benzoselenazole, pyrazine, pyrimidine, pyridazine, triazine,
Nitrogen-containing heterocycles such as oxazine, thiazine, tetrazine, polyazaine, pyridazine, pyrimidine, pyrazine, indole, isoindole, indazole, carbazole, quinoline, pyridine, isoquinoline, cinnoline, quinazoline, quinoxaline, phthalazine, purine, pyrrole, triazole, phenazine And a compound having a group. In the present invention, an imidazole compound is particularly preferable because it promotes the effect of the developer carrier of the present invention.

In particular, among the imidazole compounds, the following general formula (1) or (2)

[0047]

[Outside 3] [Wherein R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and R ₁ and R ₂ may be the same or different. R ₃ and R ₄ represent a linear alkyl group having 3 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different. ]

[0048]

[Outside 4] [Wherein, R ₅ and R ₆ represent a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and R ₅ and R ₆ may be the same. R ₇ has a carbon number represents a linear alkyl group having 3 to 30. The imidazole compound represented by the formula (1) is more preferable in terms of quick and uniform charging property of the toner and strength of the coating layer.

The reason is that the imidazole compound having the structure represented by the general formula (1) or (2) has a straight-chain alkyl group having 3 to 30 carbon atoms as a substituent.
The dispersibility of the coating layer in the resin is good, and when coexisting with the conductive spherical particles and dispersing in the coating layer, the interaction between the imidazole compound and the conductive spherical particles in the coating layer due to the interaction of the latter. It is considered that the dispersibility is improved.

The nitrogen-containing heterocyclic group constituting the nitrogen-containing heterocyclic compound may be a single ring, may be condensed with another group, or may be substituted by a substituent.

When this heterocyclic group is substituted,
Examples of the substituent include an alkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl group, a substituted amino group, a ureido group, a urethane group, an aryloxy group, a sulfamoyl group, a carbamoyl group, an alkyl or arylthio group, and an alkyl group. Or an arylsulfonyl group, an alkyl or arylsulfinyl group, a hydroxy group, a halogen atom, a cyano group, a sulfo group, an aryloxycarbonyl group, an acyl group, an alkoxycarbonyl group, an acyloxy group, a carbonamide group, a sulfonamide group, a carbosyl group, phosphorus An acid amide group, a diacylamino group, an imide group and the like can be used. The above substituents may further have a substituent.

As examples of the substituent, the substituents mentioned here can be used.

When the nitrogen-containing heterocyclic group is condensed with another group, examples of the other group include the above-mentioned nitrogen-containing heterocycle, aromatic hydrocarbon rings such as benzene, naphthalene, fluorene and pyrene, and furan. And aromatic heterocycles such as thiophene, oxadiazole and benzoxazole, and those obtained by bonding the above aromatic rings directly or by using a bonding group, for example, biphenyl, stilbene, oxazole and the like. The other group condensed with the nitrogen-containing heterocyclic ring may further have a substituent. As examples of the substituent, the substituents exemplified for the substituent of the nitrogen-containing heterocyclic ring can be used.

It is preferable to further disperse lubricating particles in the coating layer constituting the developer-carrying member of the present invention since the effect of the present invention is further promoted. Examples of the lubricating particles include graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, talc, and fatty acid metal salts of zinc stearate. Among these, graphite particles are particularly preferably used because the conductivity of the conductive coating layer is not impaired.

These lubricating particles preferably have a number average particle size of about 0.2 to 20 μm, more preferably 1 to 1 μm.
It is better to use one of 5 μm.

If the number average particle diameter of the lubricating particles is less than 0.2 μm, it is difficult to obtain sufficient lubricity, which is not preferable. The roughness becomes uneven, which is not preferable in terms of uniform charging of the toner and strength of the coating layer.

Examples of the binder resin of the coating layer constituting the developer carrier of the present invention include styrene resin, vinyl resin, polyether sulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin,
Thermoplastic resin such as fluororesin, cellulose resin, acrylic resin; heat or light curing such as epoxy resin, polyester resin, alkyd resin, phenol resin, melamine resin, polyurethane resin, urea resin, silicone resin, polyimide resin Resin. Among them, silicone resin, those having a releasable property such as fluororesin, or polyether sulfone, polycarbonate, polyphenylene oxide, polyamide,
Those having excellent mechanical properties such as phenol, polyester, polyurethane, styrene resin, and acrylic resin are more preferable.

In the present invention, the volume resistance of the coating layer of the developer carrying member is 10 ³ Ω · cm or less, more preferably 10 ³ Ω · cm or less.
It is preferably ³ to 10 ⁻² Ω · cm. When the volume resistance of the coating layer exceeds 10 ³ Ω · cm, charge-up of the toner is apt to occur, and ghost deterioration and density reduction are liable to occur.

In the present invention, in order to adjust the volume resistance of the layer to be coated, other conductive fine particles are dispersed and contained in the coating layer in combination with the conductive spherical particles and the nitrogen-containing heterocyclic compound. Is preferred.

The other conductive fine particles have a number average particle diameter of preferably 1 μm or less, more preferably 0.0 μm or less.
The thickness is preferably 1 to 0.8 μm.

The number average particle diameter of the other conductive fine particles is 1
If the thickness exceeds μm, the volume resistance of the conductive coating layer becomes low, making it difficult to control, and the charge-up phenomenon of the toner is likely to occur.

Other conductive fine particles that can be used in the present invention include, for example, carbon black such as furnace black, lamp black, thermal black, acetylene black, and channel black; titanium oxide, tin oxide, zinc oxide, and oxide black. Metal oxides such as molybdenum, potassium titanate, antimony oxide and indium oxide; conductive metals such as aluminum, copper, silver and nickel; and inorganic fillers such as graphite, metal fibers and carbon fibers.

Next, the structure of the developer carrier of the present invention will be described.

The developer-carrying member of the present invention is mainly covered with a metal cylindrical tube as a substrate and surrounding it. And a resin layer. As the metal cylindrical tube, mainly stainless steel and aluminum are preferably used.

The composition ratio of each component constituting the coating layer will be described, which is a particularly preferable range in the present invention.

The content of the conductive spherical particles dispersed in the coating layer is preferably from 2 to 120 parts by weight, more preferably from 2 to 80 parts by weight, based on 100 parts by weight of the binder resin. Good.

When the content of the conductive spherical particles is less than 2 parts by weight, the effect of adding the conductive spherical particles is small, and when it exceeds 120 parts by weight, the chargeability of the toner may be too low. .

The content of the nitrogen-containing heterocyclic compound contained in the coating layer in combination with the conductive spherical particles is as follows.
The amount is preferably 0.5 to 60 parts by weight, more preferably 1 to 50 parts by weight based on 00 parts by weight.

When the content of the nitrogen-containing heterocyclic compound is less than 0.5 part by weight, the effect of adding the nitrogen-containing heterocyclic compound is small, and when it exceeds 60 parts by weight, the volume resistance of the conductive coating layer is reduced. This makes it difficult to control the temperature, making the charge-up phenomenon more likely to occur and making it difficult to obtain the effect of adding the conductive spherical particles.

In the present invention, the ratio of the content of the conductive spherical particles in the coating layer to the content of the nitrogen-containing heterocyclic compound,
That is, the content of the conductive spherical particles: the content of the nitrogen-containing heterocyclic compound is preferably 1: 0.4 to 5.0, more preferably 1: 0.7 to 4.5, and still more preferably 1: 1. .
A value of 2 to 4.0 is preferable because the charging performance of the coating layer and the durability of the charging performance can be further improved.

The ratio of the content of the nitrogen-containing heterocyclic compound to the content of the conductive spherical particles in the coating layer is 0.4%.
When the ratio is less than 5.0, it is difficult to sufficiently control the quick and uniform charging characteristics of the toner. When the ratio is more than 5.0, the rapid and uniform charging of the toner is slightly reduced, and the durability of the charging performance is reduced. Decrease.

When lubricating particles are used in combination in the coating layer, the content of the lubricating particles is preferably 5 to 120 parts by weight, more preferably 10 to 120 parts by weight, based on 100 parts by weight of the binder resin. The content is preferably in the range of 100 parts by weight.

When the content of the lubricating particles exceeds 120 parts by weight, the coating strength and the charge amount of the toner are reduced. When the content is less than 5 parts by weight, the toner having a small particle size of 7 μm or less is used. For example, when the toner is used for a long time, the toner tends to be easily contaminated on the surface of the conductive coating layer.

When the other conductive fine particles are dispersed and contained in the coating layer, the content of the other conductive fine particles is preferably not more than 40 parts by weight, more preferably not more than 40 parts by weight, based on 100 parts by weight of the binder resin. Preferably, it is in the range of 2 to 35 parts by weight.

If the content of the conductive fine particles exceeds 40 parts by weight, the strength of the coating film and the charge amount of the toner are undesirably reduced.

In the present invention, the roughness of the coating layer surface is the center line average roughness (hereinafter referred to as “Ra”). Is preferably in the range of 0.3 to 3.5 μm, and more preferably in the range of 0.5 to 3.0 μm. If the Ra on the surface of the coating layer is less than 0.3 μm, the toner transportability may be reduced and a sufficient image density may not be obtained. If the Ra on the surface of the coating layer exceeds 3.5 μm, the toner Is too large, so that the toner cannot be charged sufficiently.

The thickness of the coating layer having the above structure is preferably 25 μm or less, more preferably 20 μm or less.
More preferably, the thickness is 4 to 20 μm to obtain a uniform film thickness, but the thickness is not particularly limited. The thickness of these layers depends on the material used for the conductive coating layer, but is in the range of 4000 to 20,000 mg as an attached weight.
/ M ² .

Next, a description will be given of a developing device, an image forming apparatus, and a process cartridge in which the above-described developer carrier of the present invention is incorporated.

FIG. 1 is a schematic view of a developing device according to an embodiment having a developer carrier of the present invention.

In FIG. 1, an electrostatic latent image holder for holding an electrostatic latent image formed by a known process, for example, an electrophotographic photosensitive drum 1 is rotated in the direction of arrow B. The developing sleeve 8 as a developer carrying member carries the one-component developer 4 having the magnetic toner supplied by the hopper 3 as a developer container, and rotates in the direction of arrow A to form the developing sleeve 8 with the developing sleeve 8. The developer 4 is transported to a development area D where the photosensitive drum 1 faces. As shown in FIG. 1, the developer 4 is provided inside the developing sleeve 8.
A magnet roller 5 in which a magnet is inscribed is arranged for magnetically attracting and holding.

The developing sleeve 8 used in the developing device of the present invention has a conductive coating layer 7 coated on a metal cylindrical tube 6 as a base. A stirring blade 10 for stirring the developer 4 is provided in the hopper 3. Reference numeral 12 denotes a gap indicating that the developing sleeve 8 and the magnet roller 5 are in a non-contact state.

The developer 4 obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 1 by friction between the magnetic toner and the conductive coating layer 7 on the developing sleeve 8. In the example of FIG. 1, in order to regulate the layer thickness of the developer 4 conveyed to the development area D, the magnetic regulation blade 2 made of a ferromagnetic metal as a developer layer thickness regulation member is moved from the surface of the development sleeve 8. It is suspended from the hopper 3 so as to face the developing sleeve 8 with a gap width of about 50 to 500 μm. The line of magnetic force from the magnetic pole N1 of the magnet roller 5 is concentrated on the magnetic regulating blade 2, so that a thin layer of the developer 4 is formed on the developing sleeve 8. In the present invention, a non-magnetic blade can be used instead of the magnetic regulating blade 2.

Thus, the thickness of the thin layer of the developer 4 formed on the developing sleeve 8 is smaller than the minimum gap between the developing sleeve 8 and the photosensitive drum 1 in the developing area D. Is preferred.

The developer carrier of the present invention is more uniformly and rapidly incorporated into a developing device of the type which develops an electrostatic latent image with a thin layer of the developer as described above, that is, a non-contact type developing device. This is effective because the developing device can achieve higher quality and higher image quality by charging the toner. However, in the developing region D, the thickness of the developer layer is limited between the developing sleeve 8 and the photosensitive drum 1. The developer carrier of the present invention can also be applied to a developing device having a thickness greater than the minimum gap, that is, a contact type developing device.

For the sake of simplicity, the following description will be made by taking the above-described non-contact type developing device as an example.

A developing bias voltage is applied to the developing sleeve 8 by a developing bias power supply 9 serving as a bias means in order to fly the one-component developer 4 having the magnetic toner carried on the developing sleeve 8. When a DC voltage is used as the developing bias voltage, a voltage having a value between the potential of the image portion of the electrostatic latent image (the region where the developer 4 is adhered and visualized) and the potential of the background portion is used as the developing sleeve. 8 is preferably applied.

To increase the density of the developed image or improve the gradation, an alternating bias voltage is applied to the developing sleeve 8 to form an oscillating electric field in which the direction is alternately reversed in the developing region D. You may. In this case, it is preferable to apply to the developing sleeve 8 an alternating bias voltage in which a DC voltage component having a value intermediate between the potential of the developed image portion and the potential of the background portion is superimposed.

In the case of so-called regular development, in which toner is adhered to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion to make it visible, the latent image is charged to a polarity opposite to the polarity of the electrostatic latent image. Use toner.

In the case of so-called reversal development, in which toner is adhered to a low potential portion of an electrostatic latent image having a high potential portion and a low potential portion to make it visible, the latent image is charged to the same polarity as the polarity of the electrostatic latent image. Use toner.

The terms “high potential” and “low potential” are expressed by absolute values. In any of these cases, the developer 4 is charged at least by friction with the developing sleeve 8.

FIG. 2 is a schematic diagram showing a configuration of a developing device according to a second embodiment of the present invention, and FIG. 3 is a schematic diagram showing a configuration of a developing device according to a third embodiment of the present invention.

In the developing device shown in FIGS. 2 and 3, as a developer layer thickness regulating member for regulating the layer thickness of the developer 4 on the developing sleeve 8, a material having rubber elasticity such as urethane rubber or silicone rubber is used. Alternatively, an elastic regulating blade 11 made of an elastic plate made of a material having metal elasticity such as phosphor bronze or stainless steel is used. This elastic regulation blade 11
The developing device of FIG. 2 is in pressure contact with the direction of rotation of the developing sleeve 8 in the opposite direction, and the developing device of FIG. 3 is characterized in that it is pressure contacted with the direction of rotation of the developing sleeve 8 in the forward direction. is there.

In these developing devices, a thin layer of developer is formed on the developing sleeve by elastically pressing the developer layer thickness regulating member 11 against the developing sleeve 8 via the developer layer. Therefore, a thinner developer layer can be formed on the developing sleeve 8 than in the case of the cited example of FIG.

The other basic structure of the developing device shown in FIGS. 2 and 3 is the same as that of the developing device shown in FIG. 1, and the same reference numerals denote the same members.

FIGS. 1 to 3 schematically illustrate the developing device of the present invention, and there are various forms in the shape of the developer container (hopper 3), the presence or absence of the stirring blade 10, and the arrangement of the magnetic poles. Needless to say. Of course, these devices can also be used for development using a two-component developer containing a toner and a carrier.

An example of an image forming apparatus using the developing device of the present invention illustrated in FIG. 3 will be described with reference to FIG.

The surface of the photosensitive drum 101 serving as an electrostatic latent image holding member is negatively charged by a contact (roller) charging means 119 serving as a primary charging means.
5, a digital latent image is formed on the photosensitive drum 101. A multi-pole permanent magnet 1 having an elastic regulating blade 111 as a developer layer thickness regulating member
The digital latent image is reversibly developed by a one-component developer 104 having a magnetic toner in a hopper 103 by a developing device provided with a developing sleeve 108 as a developer carrier in which 05 is included. . As shown in FIG. 4, the conductive substrate of the photosensitive drum 101 is grounded in the developing region D, and an alternating bias, a pulse bias, and / or a DC bias are applied to the developing sleeve 108 by a bias applying unit 109. When the recording material P is conveyed and arrives at the transfer section, the recording material P is charged by the voltage applying means 114 from the back surface (opposite to the photosensitive drum side) of the recording material by the contact (roller) transfer means 113 as a transfer means. The developed image (toner image) formed on the surface of the photosensitive drum 101 is
At 3, the image is transferred onto the recording material P. The recording material P separated from the photosensitive drum 101 is transported to a heating and pressing roller fixing device 117 as a fixing unit, and the fixing device 117 performs a fixing process of the toner image on the recording material P.

The one-component developer 104 remaining on the photosensitive drum 101 after the transfer process is removed by a cleaning blade 118.
It is removed by the cleaning means 118 having a. If the remaining one-component developer 104 is small, the cleaning step can be omitted. After the cleaning, the photosensitive drum 101 is neutralized if necessary by the erase exposure 116, and the above-described steps starting from the charging step by the contact (roller) charging means 119 as the primary charging means are repeated again.

In the above series of steps, the photosensitive drum (that is, the electrostatic latent image holding member) 101 has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. The non-magnetic cylindrical developing sleeve 108, which is a developer carrier, rotates in the developing area D so as to advance in the same direction as the surface of the photosensitive drum 101. Inside the developing sleeve 108, a multi-pole permanent magnet (magnet roll) 105 as a magnetic field generating means is arranged so as not to rotate. The one-component developer 104 in the developer container 103 is applied and carried on the developing sleeve 108 and, for example, due to friction with the surface of the developing sleeve 108 and / or friction between the magnetic toners,
A negative tribo charge is provided. Further, the elastic regulating blade 111 is provided so as to elastically press the developing sleeve 108, and the thickness of the developer layer is reduced (30 to 300 μm).
The photosensitive drum 1 in the developing region D is regulated uniformly.
Then, a developer layer thinner than the gap between the developing sleeve and the developing sleeve is formed. By adjusting the rotation speed of the developing sleeve 108, the surface speed of the developing sleeve 108 is made substantially equal to or close to the speed of the surface of the photosensitive drum 101. In the development area D,
As the developing bias voltage, an AC bias or a pulse bias may be applied to the developing sleeve 108 by the bias applying unit 109. This AC bias is f 200 ~
It is sufficient that 4,000 Hz and Vpp are 500 to 3,000 V. When the developer (magnetic toner) is transferred in the developing area D, the magnetic toner is transferred to the electrostatic latent image side by the electrostatic force on the surface of the photosensitive drum 101 and the action of a developing bias voltage such as an AC bias or a pulse bias.

Instead of the elastic regulating blade 111, a magnetic doctor blade such as iron can be used.

As described above, the primary charging means has been described using the charging roller 119 as the contact charging means, but may be a contact charging means such as a charging blade or a charging brush, or a non-contact corona charging means. However, the contact charging means is preferable in that the generation of ozone due to charging is small. Although the transfer unit has been described using the contact charging unit such as the transfer roller 113 as described above, a non-contact corona transfer unit may be used. However, the contact charging means is also preferable in that the generation of ozone due to transfer is small.

FIG. 5 shows a specific example of the process cartridge of the present invention.

In the following description of the process cartridge, components having the same functions as the components of the image forming apparatus described with reference to FIG. 4 will be described using the same reference numerals as those in FIG.

The process cartridge of the present invention has at least a developing device as a developing means and an electrostatic latent image holding member integrally formed as a cartridge, and has a main body of an image forming apparatus (for example, a copying machine, a laser beam printer, etc.). , Facsimile machine).

In the embodiment shown in FIG.
0, drum-shaped electrostatic latent image holder (photosensitive drum) 101,
A process cartridge 150 in which a cleaning unit 118 having a cleaning blade 118a and a contact (roller) charging unit 119 as a primary unit are integrated is exemplified. In the present embodiment, the developing unit 120 includes an elasticity regulating blade 111 and a one-component developer 104 having a magnetic toner in the developer container 103. The developer 104 is used. A predetermined electric field is formed between the photosensitive drum 101 and the developing sleeve 108 by the bias voltage, and the developing process is performed. In order to carry out this developing step suitably, the photosensitive drum 101
Is very important.

In the above description, the developing means 120, the electrostatic latent image holding member 101, the cleaning means 118, and the primary charging means 1
Although the embodiment in which the fourteen components are integrally formed into a cartridge has been described, in the present invention, at least two components of the developing means and the electrostatic latent image holding member are integrally formed into a cartridge. Any of three components, ie, a developing unit, an electrostatic latent image holding unit, and a cleaning unit, a developing unit, an electrostatic latent image holding unit, and a primary charging unit.
It is also possible to integrally form a cartridge by adding one component or another component.

When the above-described image forming apparatus of the present invention is applied to a facsimile printer, the light image exposure L is an exposure for printing received data. FIG. 6 is a block diagram showing an example of this case.

The controller 21 controls the image reading section 20 and the printer 29. The whole controller 21 is CP
It is controlled by U27. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 23. Data received from the partner station is sent to the printer 29 through the receiving circuit 22. Predetermined image data is stored in the image memory. The printer controller 28 is the printer 2
9 is controlled. 24 is a telephone.

The image received from the line 25 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 22, and then the CPU 27 performs a decoding process of the image information and sequentially executes the image memory 26 Is stored in When at least one page of the image is stored in the memory 26,
The image of the page is recorded. The CPU 27 is a memory 2
6, one page of image information is read out and the combined one-page image information is sent to the printer controller 28. The printer controller 28 receives 1
When the image information of the page is received, the printer 29 is controlled to record the image information of the page.

The CPU 27 receives the next page during recording by the printer 29.

As described above, image reception and recording are performed.

Next, in the present invention, a developer (toner) used for obtaining a visible image from an electrostatic latent image will be described.

The toner contained in the developer is roughly classified into a dry toner and a wet toner. However, since the solvent of the wet toner is volatilized, the dry toner is mainly used at present.
The toner mainly melt-kneads materials such as a binder resin for a toner, a release agent, a charge control agent, and a colorant, cools and solidifies the melt, pulverizes it, and then classifies it to make the particle size distribution uniform. It is a fine powder.

Examples of the binder resin for toner used in the toner include a homopolymer of styrene such as styrene, α-methylstyrene and p-chlorostyrene and a substituted product thereof; a styrene-propylene copolymer, and styrene-vinyl. Toluene copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene
Octyl acrylate copolymer, styrene-dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate Copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer Styrene copolymers such as polymers, polymethyl methacrylate; polybutyl methacrylate; polyvinyl acetate; polyethylene; polypropylene; polyvinyl butyral; polyacrylic resin; rosin, modified rosin; terpene resin; Family hydrocarbon resin, aromatic petroleum resin; include carnauba wax; paraffin wax. These can be used alone or as a mixture.

When the toner is used as a color toner (non-magnetic toner), the toner may contain a pigment as a colorant. Examples of the pigment include carbon black, nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgazine Red, Paranitroaniline Red, and Toluidine Red. , Carmin FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Rake Red C, Rhodamine FB,
Rhodamine B Lake, Methyl Bio Red B Lake,
Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Pomelo First Yellow CGG, Kaya Set Y963, Kaya Set YG, Pomelo First Orange RR, Oil Scarlet, Orazol
Brown B, Pomelo First Scarlet CG, and Oil Pink OP. It is possible to appropriately select and use from these.

When the toner is used as a magnetic toner, a magnetic powder is contained in the toner. As the magnetic powder, a substance which is magnetized in a magnetic field is used. Examples of the magnetic powder include iron, cobalt,
Powder of ferromagnetic metal such as nickel or magnetite,
Examples include alloys and compounds such as hematite and ferrite. The content of these magnetic powders is 1 to the mass of the toner.
It is preferable to set it to about 5 to 70% by mass.

In some cases, various release agents are added to and contained in the toner. Examples of such release agents include polyfluoroethylene, fluororesin, fluorocarbon oil, silicone oil, low molecular weight polyethylene, and low molecular weight polyethylene. Molecular weight polypropylene and various waxes.

In the present invention, various charge control agents may be added to the toner, if necessary, in order to facilitate positive or negative charging.

In order to exhibit F1 effects of the developer carrier of the present invention, it is preferable to use a developer having a negatively chargeable toner.

In the present invention, the non-magnetic toner may be mixed with a carrier and used as a two-component developer.
Alternatively, it can be used as a non-magnetic one-component developer without being mixed with a carrier.

The toner of the developer used in the present invention has a weight average particle diameter (D ₄ ) of preferably 3 μm to 1 μm.
The thickness of 3 μm, more preferably 3.5 μm to 10 μm is good in terms of image density and image quality such as sharpness of character lines.

The toner has a weight average particle diameter (D ₄ ) of 13 μm.
If it exceeds m, the sharpness of the character line tends to decrease, and if it is less than 3 μm, it is difficult to obtain a high image density.

Hereinafter, a method for measuring physical properties according to the present invention will be described.

(1) Measurement of Center Line Average Roughness (Ra) Based on the surface roughness of JIS B0601, about 3 points in the axial direction × 2 points in the circumferential direction = 6 points using a surf coder SE-3300 manufactured by Kosaka Laboratory. Each was measured and the average was taken.

(2) Measurement of Volume Resistance of Particles A granular sample was placed in an aluminum ring having a diameter of 40 mm.
Pressure molding with N is performed, and the volume resistance value is measured with a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka) using a four-terminal probe. The measurement environment was 20 to 25.
C., 50-60% RH.

(3) Measurement of Volume Resistance of Coating Layer A coating layer having a thickness of 7 to 20 μm was formed on a PET sheet having a thickness of 100 μm, and was subjected to the ASTM standard (D-991-8).
2) and Japan Rubber Association Standard SRIS (2301-
1969), using a voltage drop type digital ohmmeter (manufactured by Kawaguchi Electric Works) provided with electrodes having a four-terminal structure for measuring the volume resistance of conductive rubber and plastic. The measurement environment was 20-25 ° C, 50-60RH%.
And

(4) Measurement of True Density of Spherical Particles The true density of the conductive spherical particles used in the present invention was measured using a dry type densitometer Acupic 1330 (manufactured by Shimadzu Corporation).

(5) Measurement of Particle Size of Spherical Particle The particle size is measured using a Coulter LS-130 type particle size distribution analyzer (manufactured by Coulter Inc.) as a laser diffraction type particle size distribution analyzer. As a measurement method, an aqueous module is used, and pure water is used as a measurement solvent. The inside of the measurement system of the particle size distribution meter is washed with pure water for about 5 minutes, and 10 to 25 mg of sodium sulfite is added to the measurement system as an antifoaming agent, and the background function is executed.

Next, 3 to 4 drops of a surfactant are added to 10 ml of pure water, and 5 to 25 mg of a measurement sample is further added. The aqueous solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes to obtain a sample liquid, and the sample liquid is gradually added to the measuring system of the measuring apparatus. 45-55
%, The measurement is performed by adjusting the sample concentration in the measurement system, and the number average particle diameter calculated from the number distribution is obtained.

(6) Measurement of Particle Size of Conductive Fine Particle The particle size of the conductive fine particle is measured using an electron microscope.
The photographing magnification is set at 60,000 times. If it is difficult, the photograph is photographed at a low magnification and then the photograph is enlarged and printed so as to have a magnification of 60,000 times.
Measure the particle size of the primary particles on the photograph. At this time, the major axis and the minor axis are measured, and the average value is defined as the particle diameter. This is measured for 100 samples, and the 50% value is defined as the average particle size.

(7) Measurement of Toner Particle Size The toner particle size is measured using a Coulter Multisizer (manufactured by Coulter Inc.). The electrolyte is 1% N using 1st grade sodium chloride.
An aqueous aCl solution is prepared. For example, ISOTON R
-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, the electrolytic solution 1
0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, as a dispersant in 00 to 150 ml
In addition, 2 to 20 mg of the measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic
Using an aperture, the volume and number of toner particles having a size of 2 μm or more were measured to calculate the volume distribution and the number distribution.

Then, a weight-based weight average particle diameter (D ₄ : the median value of each channel is a representative value for each channel) obtained from the volume distribution according to the present invention is obtained.

(8) Measurement of Friction Charging Characteristics of Toner The toner carried on the developing sleeve is collected by suction using a metal cylindrical tube and a cylindrical filter. The triboelectric charging characteristic of the toner was measured by obtaining the charge amount per unit mass Q / M from the collected toner weight M.

[0134]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the examples do not limit the present invention at all. In the Examples and Comparative Examples, “%” and “parts” are all based on weight unless otherwise specified.

(Example 1) As conductive spherical particles, 100 parts of spherical phenolic resin particles having a number average particle diameter of 7.8 μm were coated on a coal having a number average particle diameter of 2 μm or less using a Raikai machine (automatic mortar, manufactured by Ishikawa Industries). 14 parts of the bulk bulk mesophase pitch powder is uniformly coated, heat-stabilized at 280 ° C. in air, and then calcined at 2,000 ° C. in a nitrogen atmosphere to be graphitized and further classified. .
2 μm spherical conductive carbon particles (conductive spherical particles A-1)
Was used. Table 1 shows the physical properties of the conductive spherical particles A-1.

As the nitrogen-containing heterocyclic compound, a compound represented by the formula B-
The imidazole compound particles having a number average particle size of 3 μm shown in 1 were used.

[0137]

[Outside 5] 200 parts of resol-type phenol resin solution (containing 50% methanol) 7 parts of conductive spherical particles A-1 20 parts of nitrogen-containing heterocyclic compound B-1 (imidazole compound) 20 parts of graphite 50 having a number average particle size of 3.4 μm Parts ・ Conductive carbon black 5 parts ・ Isopropyl alcohol 280 parts

The above materials were dispersed using a sand mill. Resol type phenol resin solution (Methanol 50%
Diluted with a portion of isopropyl alcohol. Conductive carbon black, graphite having a number average particle size of 3.4 μm and the nitrogen-containing heterocyclic compound B-1 were added,
Glass beads having a diameter of 1 mm were dispersed in a sand mill using media particles. The above conductive spherical particles dispersed in the remaining isopropyl alcohol were further added thereto, and further subjected to sand mill dispersion to obtain a coating liquid.

Using this coating solution, a conductive coating layer was formed on an aluminum cylindrical tube having an outer diameter of 16 mm by a spray method, and then heated at 150 ° C. for 30 minutes in a hot air drying furnace to form the conductive coating layer. Cured and developer carrier C-1
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-1.

The image forming apparatus shown in FIG. 4 having the developer carrying member C-1 and having the developing device shown in FIG.
While supplying a one-component developer using 450 (manufactured by Canon Inc.), a durability evaluation test of the developer carrying member was performed.

The following were used as the one-component developer.

• Styrene-acrylic resin 100 parts • Magnetite 100 parts • 3,5-di-tert-butylsalicylate chromium complex 1 part • Low molecular weight polypropylene 5 parts

The above-mentioned materials were kneaded, pulverized and classified by a general dry toner production method, and had a weight average particle size of 5.8 μm.
(Negatively chargeable fine powder) (magnetic toner). This fine powder 1
1.0 part of hydrophobic colloidal silica was externally added to 00 parts,
The negatively-chargeable magnetic toner was used as a one-component developer.

In the image forming apparatus used in this embodiment, a process cartridge in which an electrostatic latent image holder, a developing unit, a cleaning unit, and a primary charging unit are integrally formed as a cartridge is detachably mounted on the main body of the image forming apparatus. The configuration shown in FIG.

Example 2 The procedure of Example 1 was repeated except that the amount of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1 was changed from 20 parts to 4 parts. Thus, a developer carrier C-2 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-2.

Using the developer carrying member of C-2 in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrying member was performed. Was.

(Example 3) The procedure of Example 1 was repeated, except that the addition amount of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1 was changed from 20 parts to 40 parts. Thus, a developer carrier C-3 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-3.

Using the developer carrying member of C-3 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1. .

Example 4 100 parts of spherical phenol resin particles having a number average particle size of 5.1 μm were used as conductive spherical particles using a Raikai machine (automatic mortar, manufactured by Ishikawa Industries) to have a number average particle size of 1.4 μm or less. Coal-based bulk mesophase pitch powder of 14 parts is uniformly coated, heat-stabilized at 280 ° C. in air, and then calcined at 2,000 ° C. in a nitrogen atmosphere to be graphitized, and further classified to obtain a number average particle. 3.8 μm diameter conductive spherical carbon particles (conductive spherical particles A-
2) was used. Table 1 shows the physical properties of the conductive spherical particles A-2.

Example 1 was repeated except that 12.5 parts of conductive spherical particles A-2 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1. In the same manner as in the above, a developer carrying member C-4 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-4.

Using the developer carrying member of C-4 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 1. .

Example 5 Spherical phenol resin particles 100 having a number average particle diameter of 19.5 μm were used as the conductive spherical particles.
Part was uniformly coated with 14 parts of coal-based bulk mesophase pitch powder having a number average particle size of 1.4 μm or less using a raikai machine (automatic mortar, manufactured by Ishikawa Kogyo Co.), and after heat stabilizing treatment at 280 ° C. in air. Spherical conductive carbon particles having a number average particle diameter of 19.8 μm (conductive spherical particles A-3) obtained by graphitization by baking at 2000 ° C. in a nitrogen atmosphere and further classifying were used. First physical properties of conductive spherical particles A-3
It is shown in the table.

Example 1 was repeated except that 2.5 parts of conductive spherical particles A-3 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1. In the same manner as in the above, a developer carrying member C-5 was produced. This developer carrier C
Table 2 shows the physical properties of the conductive coating layer of No. -5.

Using the developer carrying member of C-5 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was carried out while supplying a one-component developer in the same manner as in Example 1. .

(Example 6) As conductive spherical particles, 100 parts of a spherical phenol resin having a number average particle size of 7.5 µm and 14 parts of a coal-based bulk mesophase pitch powder having a number average particle size of 1.4 µm or less were used as in Example 1. Similarly, coat uniformly using a raikai machine (automatic mortar, manufactured by Ishikawa Kogyo Co., Ltd.)
After thermal stabilization at 80 ° C, 1000 ° C under nitrogen atmosphere
, And carbonized by firing, and further classified to obtain spherical conductive carbon particles having a number average particle diameter of 7.5 μm (conductive spherical particles A-4). Table 1 shows the physical properties of the conductive spherical particles A-4.

As in Example 1 except that 7 parts of conductive spherical particles A-4 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1. Thus, a developer carrier C-6 was produced. This developer carrier C-6
Table 2 shows the physical properties of the conductive coating layer.

Using the C-6 developer-carrying member in the same image apparatus as in Example 1, a durability evaluation test of the developer-carrying member was performed while supplying a one-component developer in the same manner as in Example 1. .

(Example 7) As the conductive spherical particles, metal-coated carbon particles having a number average particle diameter of 8.3 μm (electroconductive spherical particles A) obtained by plating the particles of A-4 used in Example 6 with copper and silver were used. -5) was used. Table 1 shows the physical properties of A-5.

[0159] In the same manner as in Example 1 except that 7 parts of conductive spherical particles A-5 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1 Thus, a developer carrying member C-7 was produced. This developer carrier C-7
Table 2 shows the physical properties of the conductive coating layer.

Using the C-7 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

Example 8 The following materials were used as the conductive spherical particles, and kneading, pulverization and classification were performed to obtain conductive particles having a number average particle size of 7.4 μm. Then, a hybridizer (Nara Machinery Co., Ltd.) was used. Spherical resin particles (conductive spherical particles A-
6) was used. Table 1 shows the physical properties of A-6.

・ Styrene-acrylic resin 100 parts ・ Conductive carbon black 25 parts

Developing was conducted in the same manner as in Example 1 except that 7 parts of conductive spherical particles A-6 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1. An agent carrier C-8 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrying member C-8.

Using the C-8 developer-carrying member in the same image apparatus as in Example 1, a durability evaluation test was performed on the developer-carrying member while supplying a one-component developer in the same manner as in Example 1. .

Example 9 As a nitrogen-containing heterocyclic compound,
Imidazole compound particles represented by the general formula B-2 and having a number average particle size of 5 μm were used.

[0166]

[Outside 6]

The developer carrier C was prepared in the same manner as in Example 1 except that B-2 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. -9 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-9.

Using the developer carrying member of C-9 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1. .

Example 10 As a nitrogen-containing heterocyclic compound, imidazole compound particles represented by the general formula B-3 and having a number average particle size of 1.5 μm were used.

[0170]

[Outside 7]

The developer carrier C was prepared in the same manner as in Example 1 except that B-3 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. -10
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-10.

Using the C-10 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

Example 11 As the nitrogen-containing heterocyclic compound, imidazole compound particles represented by the general formula B-4 and having a number average particle size of 1.5 μm were used.

[0174]

[Outside 8]

The developer carrier C-11 was prepared in the same manner as in Example 1 except that B-4 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. Produced.

Table 2 shows the physical properties of the conductive coating layer of this developer carrying member C-11.

Using the C-11 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

Example 12 As a nitrogen-containing heterocyclic compound, imidazole compound particles represented by the general formula B-5 and having a number average particle size of 3.4 μm were used.

[0179]

[Outside 9]

The developer carrier C was prepared in the same manner as in Example 1 except that B-5 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. -12
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-12.

Using the C-12 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

(Example 13) As the nitrogen-containing heterocyclic compound, imidazole compound particles represented by the general formula B-6 and having a number average particle size of 2.1 µm were used.

[0183]

[Outside 10]

The developer carrier C was prepared in the same manner as in Example 1 except that B-6 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. -13
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-13.

Using the C-13 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

Example 14 Nigrosine-based dye particles (B-B) containing an oxazine ring compound and an azine ring compound and having a number average particle size of 2.9 μm as a nitrogen-containing heterocyclic compound were used.
7) was used.

The developer carrier C was prepared in the same manner as in Example 1 except that B-7 was added instead of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1. -14
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-14.

Using the C-14 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

(Example 15) 200 parts of resole type phenol resin solution (containing 50% of methanol) 10 parts of conductive spherical particles A-1 15 parts of nitrogen-containing heterocyclic compound B-1 (imidazole compound) 15 parts of conductivity 30 parts of carbon black ・ 230 parts of isopropyl alcohol

Using the above-mentioned materials, a coating liquid was obtained in the same manner as in Example 1 to prepare a developer carrying member C-15. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-15.

Using the C-15 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

(Example 16) The addition amount of the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1 was changed from 20 parts to 2.2 parts.
A developer carrying member C-16 was produced in the same manner as in Example 1 except that the parts were changed to parts.

Table 2 shows the physical properties of the conductive coating layer of this developer carrying member C-16.

Using the C-16 developer carrier in the same image apparatus as in Example 1, a durability evaluation test of the developer carrier was conducted while supplying a one-component developer in the same manner as in Example 1. .

(Example 17) 200 parts of resole type phenol resin solution (containing 50% methanol) 10 parts of conductive spherical particles A-2 15 parts of nitrogen-containing heterocyclic compound B-1 (imidazole compound) 15 parts Number average Graphite with a particle size of 1.4 μm 50 parts ・ Conductive carbon black 5 parts ・ Isopropyl alcohol 290 parts

Using the above materials, a coating liquid was obtained in the same manner as in Example 1.

Using this coating solution, a conductive coating layer was formed on an aluminum cylindrical tube having an outer diameter of 32 mm by a spray method, and then heated at 150 ° C. for 30 minutes in a hot air drying furnace to form the conductive coating layer. Cured and developer carrier C-1
7 was produced. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-17.

The C-17 developer carrier was used in an image forming apparatus (corona charging means, corona transfer means) NP6060 (manufactured by Canon) shown in FIG. 4 having the developing apparatus shown in FIG. While supplying the developer, a durability evaluation test of the developer carrying member was performed.

The following one-component developer was used.

・ 100 parts of polyester resin ・ 100 parts of magnetite ・ 1 part of 3,5-di-tert-butylsalicylate chromium complex ・ 4 parts of low molecular weight polypropylene

The above-mentioned materials are kneaded, crushed and classified by a general dry toner production method, and have a weight average particle size of 6.4 μm.
, A negatively chargeable fine powder (magnetic toner) was obtained. This fine powder 1
Externally adding 1.1 parts of hydrophobic colloidal silica to 00 parts,
A negatively chargeable magnetic toner was used, and this magnetic toner was used as a one-component developer.

Comparative Example 1 In the same manner as in Example 1 except that amorphous graphite particles a-1 having a number average particle size of 9.2 μm were used instead of the conductive spherical particles A-1. Thus, a coating solution was obtained to prepare a developer carrier D-1. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-1.

Using the developer carrying member of D-1 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 1. .

Comparative Example 2 A conductive PMMA resin particle a-2 having a number average particle size of 7.5 μm and having no conductivity was used in place of the conductive spherical particle A-1, except that the conductive spherical particle A-2 was used. A coating solution was obtained in the same manner as in Example 1, and the developer carrier D-2 was used.
Was prepared. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-2.

Using the developer carrying member of D-2 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was carried out while supplying a one-component developer in the same manner as in Example 1. .

(Comparative Example 3) The following materials were kneaded, crushed and classified in place of the conductive spherical particles A-1.
A coating solution was obtained in the same manner as in Example 1 except that the conductive irregular shaped particles a-3 having a number average particle size of 7.8 μm were used, and a developer carrier D-3 was produced.

Styrene-acrylic resin 100 parts Conductive carbon black 25 parts

Table 2 shows the physical properties of the conductive coating layer of this developer carrying member D-3.

Using the developer carrying member of D-3 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1. .

(Comparative Example 4) Metal-coated carbon particles having a number average particle diameter of 9.5 μm (electroconductive spherical particles a) obtained by plating copper and silver on the particles of A-4 used in Example 6 were used as the conductive spherical particles. -4) was used. The physical properties of the conductive spherical particles a-4 are shown in Table 1. The true density of the conductive spherical particles a-4 was 3.
It was 2 g / cm ³ .

As in Example 1, except that 7 parts of conductive spherical particles a-4 were added instead of 7 parts of conductive spherical particles A-1 used in the coating liquid of Example 1. Thus, a developer carrier D-4 was produced. This developer carrier D-4
Table 2 shows the physical properties of the conductive coating layer.

Using the developer carrying member of D-4 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 1. .

Comparative Example 5 200 parts of resole type phenol resin solution (containing 50% methanol) 7 parts of conductive spherical particles A-1 50 parts of graphite having a number average particle diameter of 3.4 μm 50 parts of conductive carbon black Parts ・ isopropyl alcohol 240 parts

Using the above materials, a coating solution was obtained in the same manner as in Example 1 to prepare a developer carrying member D-5. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-5.

Using the developer carrying member of D-5 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 1. .

(Comparative Example 6) Instead of adding the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1, a quaternary ammonium having a number average particle size of 2.2 µm containing no nitrogen-containing heterocyclic ring was used. Example 1 except that salt particles b-1 were added.
In the same manner as in the above, a developer carrying member D-6 was produced.

[0219]

[Outside 11]

Table 2 shows the physical properties of the conductive coating layer of this developer carrying member D-6.

Using the developer carrying member of D-6 in the same image apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrying member was carried out. .

Comparative Example 7 Instead of adding the nitrogen-containing heterocyclic compound B-1 used in the coating solution of Example 1, triphenylmethane having a number-average particle diameter of 1.8 μm containing no nitrogen-containing heterocyclic ring was used. Example 1 except that particle b-2 was added.
In the same manner as in the above, a developer carrying member D-7 was produced.

[0221]

[Outside 12]

Table 2 shows the physical properties of the conductive coating layer of this developer carrying member D-7.

Using the developer carrying member of D-7 in the same image apparatus as in Example 1, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 1. .

Comparative Example 8 The procedure of Example 17 was repeated, except that amorphous graphite particles a-5 having a number average particle size of 4.1 μm were used instead of the conductive spherical particles A-2. A coating liquid was obtained to prepare a developer carrying member D-8. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-8.

Using the developer carrying member of D-8 in the same image apparatus as in Example 17, a durability evaluation test of the developer carrying member was conducted while supplying a one-component developer in the same manner as in Example 17. .

[0226]

[Table 1]

[0227]

[Table 2]

[Evaluation] A durability test was performed for the following evaluation items, and the developer carrying members of Examples and Comparative Examples were evaluated. Table 3 shows the evaluation results of image density durability, durability fog and durability ghost under low temperature and low humidity. Table 4 shows evaluation results of durability of image density, durability of character sharpness, durability fog, and durability ghost under high temperature and high humidity. In addition, under high temperature and high humidity, in order to evaluate the durability of the rise of toner charge by the developer carrying member, the durability was suspended for 5 days after a certain number of sheets had been run, and the durability was further continued after the pause. The durability of sharpness, durability fog and durability ghost were evaluated.

Table 5 shows the results of the evaluation of the abrasion resistance and the stain resistance.

As the durable environment, low temperature / low humidity (L / L)
The test was carried out for two durable environments under and under high temperature / high humidity (H / H). Specifically, low temperature / low humidity (L / L) 15
C./10% RH environment, and 32.5 ° C./85% RH under high temperature / high humidity (H / H).

(Evaluation Method) (1) Image Density The image density was measured using a reflection densitometer RD918 (manufactured by Macbeth) at five points of the density of a solid black portion when solid printing was performed, and the average value was used as the image density. And

(2) Fog density The reflectance (D1) of the solid white portion of the recording paper on which the image was formed was measured, and the reflectance (D2) of an unused recording paper having the same cut as that of the recording paper used for the image formation was measured. ) Was measured, D1-D2 values were determined at five points, and the average value was defined as the fog density. The reflectance was measured with TC-6DS (manufactured by Tokyo Denshoku).

(3) Ghost The position of the developing sleeve that has developed the image in which the solid white portion and the solid black portion are adjacent comes to the developing position at the next rotation of the developing sleeve, and the halftone image is developed. The density difference appearing on the image was visually evaluated according to the following criteria. ：: No difference in shade was observed. ○ △: A slight difference in shade is observed. Δ: Some difference in shading is observed, but practical. X: The difference in shading is remarkable, and it is not practical.

(4) Abrasion resistance of the coating layer The arithmetic average roughness (Ra) of the surface of the developer carrying member was measured before and after running.

(5) Stain Resistance of Coating Layer The surface of the developer bearing member after durability was observed by SEM, and the degree of toner contamination was evaluated according to the following criteria. : Slight contamination is observed. ○ △: Slight contamination is observed. Δ: Contamination is partially observed. X: Remarkable contamination is observed.

(6) Character sharpness Characters on transfer paper imaged in a high-temperature and high-humidity environment (32.5 ° C., 85%) were magnified about 30 times and evaluated according to the following evaluation criteria. ○ (excellent): The lines are very sharp and there is almost no scattering. ○ △ (good): The line is relatively sharp, with only slight scattering. Δ (Normal): The lines are slightly blurred and the lines are blurred. X (bad): less than the level of △.

[0237]

[Table 3]

[0238]

[Table 4]

[0239]

[Table 5]

[0240]

[Table 6]

[0241]

As described above, according to the present invention,
Maintain a state in which a good image can be provided for a long time because the ability to impart a charge to the toner more uniformly and quickly is improved and the durability is further improved as compared with a conventionally used developer carrier. Becomes possible.

Therefore, according to the present invention, a highly durable developer carrier having a good charge-imparting ability without deterioration such as abrasion of the coating layer on the surface of the developer carrier due to repeated copying or durability and toner contamination can be obtained. It is possible to provide a high-quality image with high image density and good sharpness of character lines without causing deterioration of image density, deterioration of sleeve ghost and fog even under different environments.

[Brief description of the drawings]

FIG. 1 is a schematic view of a developing device according to an embodiment having a developer carrier on which a conductive coating layer of the present invention is formed.

FIG. 2 is a schematic view of a developing device of another embodiment of the present invention in which a regulating member of a developer layer is different in the developing device of FIG.

FIG. 3 is a schematic view of a developing device according to another embodiment of the present invention, which is different from the developing device of FIG.

FIG. 4 is a schematic explanatory view of the image forming apparatus of the present invention.

FIG. 5 is a schematic explanatory view of a specific example of the process cartridge of the present invention.

FIG. 6 is a schematic view of a conventional developing device having a developer carrier on which a resin coating layer is not formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum (electrostatic latent image holding body) 2 Magnetic regulation blade 3 Hopper (developer container) 4 Developer (toner) 5 Magnet roller 6 Metal cylindrical tube 7 Conductive coating layer 8 Developing sleeve 9 Developing bias power supply 10 Stirring blade Reference Signs List 11 elastic regulating blade 12 gap 101 photosensitive drum 103 developer container 104 one-component developer 105 multipolar permanent magnet 108 developing sleeve 109 bias applied voltage 111 elastic regulating blade 113 contact (roller) transfer means 114 voltage applying means 115 exposure 116 erase Exposure 118 Heat and pressure roller fixing device 118a Cleaning blade 119 Contact (roller) charging means 120 Developing means N1, N2, S1, S2 Magnetic pole A Developing sleeve rotation direction B Photosensitive drum rotation direction D Developing area P Recording material

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Saiki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Satoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Yasuhide Goseki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (72)

[Claims] 1. A developer carrier having at least a substrate and a coating layer covering the substrate, wherein the coating layer comprises:
A binder resin, and a number average particle size of 0.1 dispersed in the binder resin.
A developer carrier comprising at least conductive spherical particles having a density of 3 to 30 μm and a true density of 3 g / cm ³ or less, and a nitrogen-containing heterocyclic compound. 2. The developer carrier according to claim 1, wherein the nitrogen-containing heterocyclic compound is an imidazole compound. 3. The imidazole compound represented by the following formula (1):
Or (2) [outside 1] [Wherein R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and R ₁ and R ₂ may be the same or different. R ₃ and R ₄ represent a linear alkyl group having 3 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different. [Outside 2] [Wherein, R ₅ and R ₆ represent a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and R ₅ and R ₆ may be the same. R ₇ has a carbon number represents a linear alkyl group having 3 to 30. 3. The developer carrier according to claim 2, wherein the compound is a compound represented by the formula: 4. The ratio of the major axis / minor axis of the conductive spherical particles is:
3. The developer carrier according to claim 1, wherein the developer carrier is in a range of 1.0 to 1.5. 5. The conductive spherical particles having a volume resistance of 10 ⁶
The developer carrier according to any one of claims 1 to 3, wherein the density is equal to or less than Ω · cm. 6. The developer carrier according to claim 1, wherein the conductive spherical particles are carbon particles. 7. The developer carrier according to claim 5, wherein the surface of the carbon particles is plated with a conductive metal, a conductive metal oxide, or both. 8. The developer carrier according to claim 1, wherein the conductive spherical particles are resin particles whose surfaces are made conductive. 9. The developer carrier according to claim 1, wherein the conductive spherical particles are resin particles in which conductive fine particles are dispersed. 10. The developer carrier according to claim 1, wherein the conductive spherical particles are carbonized inside and carbonized outside. . 11. The conductive spherical particles are obtained by coating a surface of a spherical resin particle with a bulk mesophase pitch, subjecting the coated particles to a heat treatment in an oxidizing atmosphere, and then firing the same in an inert atmosphere or vacuum. The developer carrier according to claim 10, wherein 12. The coating layer according to claim 1, wherein the coating layer further contains lubricating particles in addition to the conductive spherical particles and the nitrogen-containing heterocyclic compound. Developer carrier. 13. The lubricating particles are selected from the group consisting of graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, talc and fatty acid metal salts. 13. The developer carrier according to claim 12, comprising at least one kind. 14. The coating layer according to claim 1, wherein the coating layer further contains conductive fine particles in addition to the conductive spherical particles and the nitrogen-containing heterocyclic compound. Developer carrier. 15. The method according to claim 1, wherein the conductive fine particles contain at least one selected from the group consisting of carbon black, metal oxides, metals and inorganic fillers.
5. The developer carrier according to item 4. 16. The developer carrier according to claim 1, wherein a center line average roughness (Ra) of the surface of the conductive coating layer is 0.3 to 3.5 μm. . 17. The ratio between the content of the conductive spherical particles in the coating layer and the content of the nitrogen-containing heterocyclic compound is as follows: conductive spherical particles: nitrogen-containing heterocyclic compound = 1: 0. .4 ~
17. The developer carrier according to claim 1, wherein the developer carrier satisfies 5.0. 18. The ratio between the content of the conductive spherical particles and the content of the nitrogen-containing heterocyclic compound in the coating layer is as follows: conductive spherical particles: nitrogen-containing heterocyclic compound = 1: 0. .7-
The developer carrier according to any one of claims 1 to 16, wherein 4.5 is satisfied. 19. The ratio between the content of the conductive spherical particles in the coating layer and the content of the nitrogen-containing heterocyclic compound is as follows: conductive spherical particles: nitrogen-containing heterocyclic compound = 1: 1. .2
17. The developer carrier according to claim 1, wherein the developer carrier satisfies 4.0. 20. A developing device comprising: a developer container for storing a developer; and a developer carrying member for carrying the developer contained in the developer container and transporting the developer to a developing area. In the apparatus, the developer carrier has at least a substrate and a coating layer covering the substrate, the coating layer includes a binder resin, and a number average particle size dispersed in the binder resin. 0.3-30μ
m, a developing device comprising at least conductive spherical particles having a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound. 21. The developing device according to claim 20, wherein the developing device further comprises a developer layer thickness regulating member for forming the developer layer on the developer carrier. Developing device. 22. The developing device according to claim 21, wherein said developer layer thickness regulating member is a magnetic regulating blade. 23. The developing device according to claim 21, wherein said developer layer thickness regulating member is elastically pressed against said developer carrier via said developer. 24. The developing device according to claim 23, wherein said developer layer thickness regulating member is an elastic regulating member. 25. The developer according to claim 20, wherein the developer is a magnetic one-component developer containing a magnetic toner.
5. The developing device according to any one of 4. 26. The developer according to claim 20, wherein the developer is a non-magnetic one-component developer containing a non-magnetic toner.
The developing device according to any one of 21, 23 and 24. 27. The developing device according to claim 20, wherein the developer is a two-component developer containing a toner and a carrier. 28. The developing device according to claim 20, wherein said developing device further comprises a power supply having means for forming an oscillating electric field in said developing region. 29. The developing device according to claim 28, wherein said power supply is for applying an alternating bias voltage to said developer carrier. 30. The layer thickness of the developer formed on the surface of the developer carrier is smaller than the minimum gap between the electrostatic latent image carrier for forming the development area and the developer carrier. 28. The developing device according to claim 20, wherein the developing device is also thin. 31. The developing device further includes a power supply having means for forming an oscillating electric field in the developing region, and a layer thickness of the developer formed on a surface of the developer carrier is: 28. The developing device according to claim 20, wherein the developing device is thinner than a minimum gap between the electrostatic latent image holding member for forming the developing region and the developer carrying member. 32. The developer carrier according to claim 2, wherein
21. The developing device according to claim 20, wherein the developer carrier is any one of the above. 33. A step of carrying a developer contained in a developer container on a developer carrier; and carrying the developer carried on the developer carrier with the developer carrier and an electrostatic latent image. Transferring the electrostatic latent image formed on the electrostatic latent image holding member by the developer carried on the developer carrier in the developing region; Developing, the developer carrier has at least a substrate and a coating layer covering the substrate, and the coating layer includes a binder resin and a binder resin. Dispersed number average particle size 0.3-30μ
m, at least a conductive spherical particle having a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound. 34. The developing method according to claim 33, wherein the electrostatic latent image holding member is a photoconductor for electrophotography. 35. The developing method according to claim 33, wherein a layer of the developer is formed on the developer carrying member by a developer layer thickness regulating member. 36. The developing method according to claim 35, wherein said developer layer thickness regulating member is a magnetic regulating blade. 37. The developing method according to claim 35, wherein said developer layer thickness regulating member is elastically pressed against said developer carrying member via a developer. 38. The developing method according to claim 37, wherein said developer layer thickness regulating member is an elastic regulating member. 39. The developer according to claim 33, wherein the developer is a magnetic one-component developer containing a magnetic toner.
9. The developing method according to any one of the above items 8. 40. The developer according to claim 33, wherein the developer is a non-magnetic one-component developer containing a non-magnetic toner.
39. The developing method according to any one of 34, 35, 37 and 38. 41. The developing method according to claim 33, wherein the developer is a two-component developer containing a toner and a carrier. 42. The method according to claim 33, wherein an oscillating electric field is formed in said developing area to develop said electrostatic latent image with a developer carried on said developer carrier. The developing method described in the above. 43. The method according to claim 42, wherein an alternating bias voltage is applied to said developer carrier to develop said electrostatic latent image with a developer carried on said developer carrier. Development method. 44. The layer thickness of the developer formed on the surface of the developer carrier is set to be smaller than the minimum gap between the electrostatic latent image carrier for forming the development area and the developer carrier. 42. The developing method according to claim 33, wherein the electrostatic latent image is developed with a developer carried on the developer carrying member by setting the electrostatic latent image to be thin. 45. The layer thickness of the developer formed on the surface of the developer carrier is set to be smaller than the minimum gap between the electrostatic latent image carrier for forming the development area and the developer carrier. 43. The electrostatic latent image is developed with a developer carried on the developer carrier by forming an oscillating electric field in the developing area by setting the thickness to be thinner. Or the developing method described in the above. 46. The developer carrier according to claim 2, wherein
34. The developing method according to claim 33, wherein the developer carrying member is any one of the above. 47. (i) an electrostatic latent image holding member for holding an electrostatic latent image, and (ii) an electrostatic latent image holding member for developing the electrostatic latent image with a developer in a developing area to form a developed image. In an image forming apparatus having at least a developing device, the developing device carries a developer container containing a developer, and carries the developer contained in the developer container, and transports the developer to a developing area. The developer carrier has at least a substrate and a coating layer covering the substrate, and the coating layer includes a binder resin and the binder. Number average particle size 0.3 to 30μ dispersed in resin
m, an image forming apparatus comprising at least conductive spherical particles having a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound. 48. The image forming apparatus according to claim 47, wherein said electrostatic latent image holding member is a photoconductor for electrophotography. 49. The image forming apparatus according to claim 47, wherein the image forming apparatus further comprises a transfer unit for transferring the developed image onto a recording material. 50. The image forming apparatus according to claim 47, wherein the image forming apparatus further comprises a fixing unit for fixing the developed image on a recording material. apparatus. 51. The developing device according to claim 47, wherein said developing device further comprises a developer layer thickness regulating member for forming said developer layer on said developer carrier. An image forming apparatus according to any one of the above. 52. The image forming apparatus according to claim 51, wherein said developer layer thickness regulating member is a magnetic regulating blade. 53. The image forming apparatus according to claim 51, wherein said developer layer thickness regulating member is elastically pressed against said developer carrier via said developer. 54. The image forming apparatus according to claim 53, wherein said developer layer thickness regulating member is an elastic regulating member. 55. The developer according to claim 47, wherein the developer is a magnetic one-component developer containing a magnetic toner.
5. The image forming apparatus according to any one of 4. 56. The developer according to claim 47, wherein said developer is a non-magnetic one-component developer containing a non-magnetic toner.
The image forming apparatus according to any one of 48, 49, 50, 51, 53, and 54. 57. The image forming apparatus according to claim 47, wherein the developer is a two-component developer containing a toner and a carrier. 58. The image forming apparatus according to claim 47, wherein said developing device further comprises a power supply having means for forming an oscillating electric field in said developing area. . 59. The image forming apparatus according to claim 58, wherein the power supply is for applying an alternating bias voltage to the developer carrier. 60. The layer thickness of the developer formed on the surface of the developer carrier is smaller than the minimum gap between the electrostatic latent image carrier for forming the development area and the developer carrier. The image forming apparatus according to any one of claims 47 to 57, wherein the thickness is also thin. 61. The developing device further comprises a power supply having means for forming an oscillating electric field in the developing area, wherein a layer thickness of the developer formed on a surface of the developer carrier is: 58. The image forming apparatus according to claim 47, wherein the gap is thinner than a minimum gap between the electrostatic latent image holder for forming the developing area and the developer carrier. 62. The developer carrier according to claim 2, wherein
48. The image forming apparatus according to claim 47, wherein the image forming apparatus is the developer carrying member according to any one of the above. 63. A process cartridge detachable from a main body of an image forming apparatus, comprising: (i) an electrostatic latent image holder for holding an electrostatic latent image; and (ii) the electrostatic latent image. Is developed with a developer in a development area, and at least integrally includes a developing unit for forming a developed image, wherein the developing unit includes a developer container that stores the developer, and a developer container. A developer carrying member for carrying the stored developer and transporting the developer to a developing area, the developer carrying member comprising at least a substrate and a coating covering the substrate; A coating layer, and the coating layer has a number average particle diameter of 0.3 to 30 μm dispersed in the binder resin.
m, a process cartridge containing at least conductive spherical particles having a true density of 3 g / cm ³ or less and a nitrogen-containing heterocyclic compound. 64. The process cartridge according to claim 63, wherein said electrostatic latent image holding member is an electrophotographic photosensitive member. 65. The process cartridge according to claim 63, wherein the process cartridge further has a developer layer thickness regulating member for forming a developer layer on the developer carrier. Process cartridge. 66. The process cartridge according to claim 65, wherein said developer layer thickness regulating member is a magnetic regulating blade. 67. The process cartridge according to claim 65, wherein said developer layer thickness regulating member is elastically pressed against said developer carrier via said developer. 68. The process cartridge according to claim 67, wherein said developer layer thickness regulating member is an elastic regulating member. 69. The developer according to claim 63, wherein the developer is a magnetic one-component developer containing a magnetic toner.
9. The process cartridge according to any one of the above items 8. 70. The developer according to claim 63, wherein the developer is a non-magnetic one-component developer containing a non-magnetic toner.
69. The process cartridge according to any one of items 64, 65, 67 or 68. 71. The process cartridge according to claim 63, wherein the developer is a two-component developer containing a toner and a carrier. 72. The developer carrier according to claim 2, wherein
64. The process cartridge according to claim 63, wherein the developer carrier is any one of the above.