JP2012133174A - Toner carrier, developing device, and image forming method and apparatus - Google Patents

Abstract

Toner that has low power consumption, stably forms a toner cloud stably for a long period of time, and supplies the toner to the electrostatic latent image on the surface of the photoreceptor to visualize the electrostatic latent image Provided are a carrier, a developing device on which the toner carrier is mounted, an image forming apparatus on which the developing device is mounted, and an image forming method using the toner carrier.
Hopping is performed by developing a latent electrostatic image on a surface of a photoreceptor facing a toner carrier by hopping the toner carried on the toner carrier by an electric field formed by a plurality of electrodes of the toner carrier. The toner carrier used for development, comprising a conductive or insulating support, an insulating layer formed on the support, and a plurality of electrodes arranged at regular intervals on the insulating layer And a surface layer covering the plurality of electrodes, and the insulating layer is made of at least one polyimide resin.
[Selection] Figure 3

Description

  The present invention relates to a toner carrier, a developing device including a toner carrier, an image forming apparatus including the developing device, and an image forming method. More specifically, the present invention relates to a toner hopping toner on a surface of a toner carrier. A developing device that develops by attaching to a latent image on an image carrier (photosensitive member), a toner carrier mounted on the developing device, an image forming apparatus such as a copying machine, a printer, and a facsimile equipped with the developing device, and The present invention relates to an image forming method.

  In an image forming apparatus such as a copying machine or a printer, a developing device using an electrophotographic process is used. Among such developing devices, a non-contact type developing device that performs development without bringing a toner carrier carrying a developer (toner) into contact with a photosensitive member on which an electrostatic latent image is formed has attracted attention. ing. As examples of the non-contact method, a powder round method, a jumping method, a method using an electric field curtain, and the like are known.

In the jumping development method, the toner is supplied to the toner carrier without contacting the photoreceptor and the toner carrier, and the toner particles precharged between the photoreceptor and the toner carrier are jumped. The electrostatic latent image on the photoreceptor is developed with particles. This jumping development method requires an applied voltage that exceeds the adhesion between the toner particles and the toner carrier.
Further, the electric field curtain developing method is formed by applying an alternating electric field to the electrode of a toner carrier having a plurality of electrodes arranged at a constant interval therein, and forming an alternating unequal electric field generated on the surface of the toner carrier. The toner particles charged in advance are hopped by the electric field curtain, and the toner particles are supplied to the electrostatic latent image on the photosensitive member for development. In this electric field curtain developing method, toner particles hop on the surface of the toner carrier, so that the adhesion between the toner particles and the surface of the toner carrier becomes substantially zero, and the toner particles are peeled off from the surface of the toner carrier for development. Since no force is required, the toner can be sufficiently conveyed to the latent image carrier side with a low voltage.

In consideration of such a phenomenon, the electric field curtain type developing device disclosed in Patent Document 1 uses a developer carrying carrier in which a surface protective layer made of an insulating material or the like is coated on a plurality of electrodes. As a result, the toner charge does not leak to the electrode, and the toner charge is not lost to cause hopping failure.
The developing device disclosed in Patent Document 2 supplies the toner particles on the surface of the toner carrier without being tribo-charged in advance, and charges the toner particles by hopping the toner particles by an alternating electric field. It is disclosed that the surface (protective layer) of the toner carrier is formed of a material that promotes frictional charging of the toner toward the normal charging polarity side.
However, since these developing devices are provided with two types of electrodes having different potentials on the insulating layer, leakage is likely to occur between the electrodes when a gap is formed between the electrodes. When leakage occurs between the electrodes, the electric field for hopping the toner is lost because the potential between the two types of electrodes cannot be maintained.

  In addition, the present inventors have previously proposed a developing device using a toner carrier in which a specific toner is used and a surface layer covering an electrode is formed of a polymer compound containing a specific structural unit (Patent Document 3). . According to this developing device, it is possible to stably form a cloud of toner for a long period of time and develop an electrostatic latent image. However, this toner carrier and developing device has not been studied until operation with low power consumption.

  The present invention has been made in view of the above problems, and has an object of low power consumption, stably forming a cloud of toner stably for a long period of time, and applying toner to an electrostatic latent image on the surface of a photoreceptor. A toner carrier capable of developing an electrostatic latent image by supplying the toner, a developing device equipped with the toner carrier, an image forming device equipped with the developing device, and an image forming method using the toner carrier It is to provide.

The present inventors have hopped toner carried on a toner carrier by an electric field formed by a plurality of electrodes of the toner carrier and developed an electrostatic latent image on the surface of the photoreceptor facing the toner carrier. In development, an insulating layer formed between a conductive or insulating support of a toner carrier and a plurality of electrodes is composed of a polyimide resin, so that development can be performed with low power consumption. It has been found that all of the leakage of toner, the flying of toner on the toner carrier, and the occurrence of abnormal images can be suppressed. The present invention has been made based on these findings.
According to the present invention, the following (1) to (12) are provided.

(1) Hopping development in which toner carried on a toner carrier is hopped by an electric field formed by a plurality of electrodes of the toner carrier, and an electrostatic latent image on the surface of the photoreceptor facing the toner carrier is developed. A toner or carrier that is provided on the substrate, a conductive or insulating support, an insulating layer formed on the support, and a plurality of electrodes arranged at regular intervals on the insulating layer; And a surface layer covering the plurality of electrodes, and the insulating layer is made of at least one polyimide resin.
(2) The above support (1) is characterized in that one electrode is constituted by a conductive support, and a voltage is applied to the electrode and the plurality of electrodes to be the other electrode. The toner carrier described in 1.
(3) The support is an insulating support, and the plurality of electrodes include electrodes of a first electrode pattern and electrodes of a second electrode pattern alternately formed in parallel, and the first electrode The toner carrier according to (1) above, wherein a voltage is applied to the electrode of the electrode pattern and the electrode of the second electrode pattern.
(4) The toner carrier according to (3) above, wherein the electrodes of the first electrode pattern and the electrodes of the second electrode pattern are arranged in a comb shape.
(5) The toner carrier according to any one of (1) to (4), wherein the plurality of electrodes are arranged in a toner transport direction and generate an electric field.
(6) The toner carrier according to any one of (1) to (5), wherein the surface layer is made of a polycarbonate resin.

(7) Hopping development in which the toner carried on the toner carrying member is hopped by an electric field formed by a plurality of electrodes of the toner carrying member to develop an electrostatic latent image on the surface of the photoreceptor facing the toner carrying member. In the developing device, the toner carrying member is the toner carrying member according to any one of the above (1) to (6).
(8) The developing device according to (7), wherein the toner carrier is disposed in a non-contact state facing the photoconductor with a space.

(9) electrostatic latent image forming means for forming an electrostatic latent image on the photosensitive member, and toner carried on the toner carrier are hopped by an electric field formed by a plurality of electrodes of the toner carrier, In the image forming apparatus including a hopping developing unit that develops an electrostatic latent image on the surface of the photoreceptor facing the toner carrier, the hopping developing unit is the developing device described in the above (7) or (8). An image forming apparatus.

(10) an electrostatic latent image forming step of forming an electrostatic latent image on the photosensitive member, and the toner carried on the toner carrier is hopped by an electric field formed by a plurality of electrodes of the toner carrier, In the image forming method including a hopping development process for developing an electrostatic latent image on the surface of the photoreceptor facing the toner carrier, the toner carrier is any one of the above (1) to (6). An image forming method characterized by that.

  In the toner carrier of the present invention, when an alternating electric field or a rectangular wave is applied to the electrodes to form an electric field that causes toner hopping, toner hopping can be caused with low power consumption. As a result, a developing device capable of developing the electrostatic latent image by supplying toner to the electrostatic latent image on the surface of the photosensitive member with low power consumption, a toner carrier mounted in the developing device, and an image forming on which the developing device is mounted. A device can be provided.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a diagram showing an embodiment of a developing device for two-component development in the present invention. FIG. 2 is a schematic diagram illustrating a toner cloud state in the developing device illustrated in FIG. 1. It is explanatory drawing of the state of an electric field change of the example of an upper-and-lower electrode type toner carrier in this invention, and the shape of an electrode. It is explanatory drawing of the state of an electric field change of the example of a comb-tooth-type toner carrier in this invention, and the shape of an electrode.

  The toner carrier of the present invention includes an insulating layer formed on a conductive support or an insulating support, a plurality of electrodes arranged on the insulating layer at regular intervals, and a surface layer covering the plurality of electrodes And a conductive support (which functions as one electrode) so that the electric field between the plurality of electrodes and the conductive or insulating support is periodically reversed. Or a voltage applying means for applying a voltage between the electrodes, and the toner is hopped by an electric field between the electrodes to form a toner cloud, and the insulating layer is composed of at least one polyimide resin. It is composed of what is done.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a developing device (and an image forming apparatus using the same) according to an embodiment of the present invention.
In FIG. 1, (1) is a drum-shaped photoconductor rotating in the direction of the arrow (A), (2) is a charging roller for uniformly charging the surface of the photoconductor (1), and (3) is for image information. An exposure device that irradiates the surface of the photoreceptor (1) with laser light or the like, and (4) is a developing device that supplies toner to the electrostatic latent image formed on the surface of the photoreceptor (1). (5) is a transfer roller for transferring the toner image formed by the developing device (3) on the surface of the photoreceptor (1) onto a transfer material (P) such as transfer paper, and (6) is on the transfer material (P). The cleaning device removes toner remaining on the surface of the photoreceptor (1) from the surface of the photoreceptor (1) after transferring the toner image. (7) is a fixing device that heats and presses the unfixed toner image transferred onto the transfer material (P) and fixes it on the transfer material (P).

A method for forming a toner image on the transfer material (P) using this image forming apparatus will be described.
The surface of the photoreceptor (1) rotating in the direction of the arrow (A) is uniformly charged by applying a predetermined voltage by the charging roller (2). An electrostatic latent image is formed on the surface of the photoconductor (1) by irradiating the surface of the photoconductor (1) uniformly charged with laser light corresponding to desired image information from the exposure device (3). To do. Subsequently, toner is supplied from the developing device (4) and electrostatically attached to the electrostatic latent image formed in this way, and the electrostatic latent image is converted into a toner image (visualization). . The toner image thus formed is biased while the surface of the photoreceptor (1) and the transfer material (P) are pressed against each other by the transfer roller (5) and the transfer material (P) is conveyed in the direction of the arrow (B). A voltage is applied to transfer from the surface of the photoreceptor (1) to the surface of the transfer material (P). Thereafter, the toner image transferred onto the transfer material (P) is heated and pressed by the heating roller (7a) and the pressure roller (7b) of the fixing device (7) to be fixed on the transfer material (P). . The photoreceptor (1) having the toner image transferred onto the transfer material P in this way removes the toner remaining on the surface of the photoreceptor (1) by the cleaning device (6), and removes the surface of the photoreceptor (1). It is cleaned and again charged uniformly by the charging roller (2). Thereafter, as described above, an electrostatic latent image is formed by the exposure device (3), the electrostatic latent image is converted into a toner image by the developing device (4), and is transferred onto the transfer material (P) by the transfer roller (5). The operation of transferring the toner image and cleaning the surface of the photoreceptor (1) by the cleaning device (6) is repeated.

As described above, the present invention is characterized by the developing device (4) that converts the electrostatic latent image formed on the surface of the photoreceptor (1) into a toner image with toner.
Here, the charging means in the case of using a one-component developer and a two-component developer will be described as follows.

  In the case of using a one-component developer, as shown in FIG. 1, the developing device (4) according to an embodiment of the present invention places the toner in a container (8) that stores toner (T). A developing roller (9), which is a toner carrier to be supplied from the opening (8a) of the container (8), is rotatably attached to (1), and is rotated in the direction of arrow (C) by a driving means (not shown). It has become. Then, the toner (T) is circulated while being stirred by the circulation paddle (10) to charge the toner (T), and the toner (T) is supplied to the surface of the developing roller (9). Reference numeral (12) in FIG. 1 denotes a toner supply port for supplying replenished toner.

  In the case of using a two-component developer, as shown in FIG. 2, a two-component developer (56) which is another embodiment of the present invention causes a two-component developer ear to be a developing roller (9) ). Specifically, a two-component developer in which a magnetic carrier powder having a particle size of 50 [μm] and a toner having a particle size of about 6 [μm] are mixed in a weight ratio of 7 to 8 [wt%] 56) is conveyed to the developing roller (9) by the magnet sleeve (57) containing the permanent magnets, and a part of the toner is applied to the DC bias potential between the magnet sleeve (57) and the developing roller (9). To the surface of the developing roller (9).

  The toner carrier (9) supplied with the toner (T) in this manner is pumped up while holding the toner (T) on the surface thereof by electrostatic force, and has a predetermined distance from the toner carrier (9). The amount of toner to be pumped is regulated by a blade-like toner regulating member (11) attached to (8). As will be described later, an alternating electric field is applied to the toner carrier (9) at the opening (8a) to form a cloud of toner (T). As a result, the toner (T) is electrostatically supplied from the cloud to the electrostatic latent image on the surface of the photoreceptor (1) to form a toner image.

The toner carrier (9) will be described.
The configuration of the electrode of the toner carrier (9) is such that when the support is a conductive support, an upper and lower electrode application method is adopted, and when the support is an insulating support, a comb-teeth electrode is applied. The method is adopted.

[Upper and lower electrode application method]
As shown in FIG. 4, the toner carrier (9) has a laminated structure in the order of a conductive support (91A), an insulating layer (95), an electrode pattern having an electrode (91Bb), and a surface layer (98) from the bottom. It has become.
More specifically, the toner carrier (9) is shown in FIGS. 4A and 4B (note that FIG. 4A is a cross-sectional view taken along the line AA ′ in the top view of FIG. 4B). As shown in FIG. 2, the first electrode and the second electrode are provided, and the function of one electrode (for example, “first electrode”) is assigned to the conductive support (91A), so that the conductive support ( 91A) is the A phase, and the electrode pattern (91B) having a plurality of linear electrodes (for example, “second electrode”: 91Bb) formed on the insulating layer (95) is the B phase, and the conductive support ( The toner particles are hopped by the potential difference between the electrode 91A) and the electrode 91Bb to form a toner cloud. In this example, the conductive support (91A) is grounded.

In addition, the electrode pattern (91B) is formed by forming a copper thin film by vapor deposition on the peripheral surface of the support (91A) on which an insulating layer (95) is formed and formed into a cylindrical shape. It is possible by processing into a desired shape by a photoresist method. There is no particular limitation on the formation method, and in addition to patterning using a photoresist method, it may be formed by drawing using, for example, an ink jet apparatus.
There is no limitation in particular about the magnitude | size of an electroconductive support body (91A), What is necessary is just to use what the practitioner of this invention selected suitably. Further, the width (d) of the electrode (91Bb) and the distance (D) between the electrodes (91Bb) are not particularly limited, and may be determined appropriately by the practitioner of the invention. Since the interval (D) can be widened, a short circuit can be prevented, which is preferable.

However, since the formation of the toner cloud is affected by the width (d), the interval (D), the alternating voltage, and the like of the electrode pattern (91Bb), in order to form a good cloud, the electrode of the electrode pattern (91Bb) The width (d) and the interval (D) may be set to a width of 40 μm to 250 μm and an interval of 85 μm to 500 μm, respectively. The thickness of the electrode of the electrode pattern (91Bb) is suitably about 1 μm to 20 μm. Moreover, as an alternating voltage, frequency 100Hz-5KHz and 100V-3KV are suitable.
The material constituting the electrode (91Bb) can be used as long as it has a high conductivity (for example, a paste in which silver particles or conductive carbon is dispersed), but if it is in a paste form, an electrode pattern is drawn. This is preferable because of this.

  In the toner carrier (9) in this embodiment, a single-phase alternating voltage is used as the alternating voltage power supply, but a plurality of alternating voltage power supplies having different periods can also be used. . As shown in FIGS. 3 and 4, the positive and negative directions are periodically switched between two electrodes (conductive support (91A) and a plurality of linear electrodes (91Bb)) provided on the toner carrier. By applying a voltage, the electric field on the surface of the toner carrying member is periodically reversed in the reverse direction. Due to the time-varying electric field, the toner particles are separated from the surface of the photoreceptor (1) and the toner carrying member (9). A toner cloud is formed by hopping with the surface layer (98), and the toner (T) of the cloud is electrostatically attracted toward the electrostatic latent image formed on the surface of the photoreceptor (1). A toner image can be formed by adhering.

(Conductive support)
Examples of the conductive support (91A) include metals such as Al, Ni, Fe, Cu, and Au, or alloys thereof, as well as Al, Ag, and Au on an insulating substrate such as polyester, polycarbonate, polyimide, and glass. Metals such as In ₂ O ₃ and SnO ₂ formed into a thin film, carbon black, graphite, aluminum, copper, nickel and other metal powders, conductive glass powder, etc. are uniformly dispersed in the resin In addition, a cylindrical support formed from a resin substrate obtained by imparting conductivity to a resin, paper subjected to conductive treatment, or the like can be used.

(Insulating layer)
The insulating layer (95) sandwiched between the conductive support (91A) and the electrode (91Bb) on the insulating layer will be described.
When an alternating voltage is applied between the conductive support (91A) and the electrode (91Bb), an increase in power consumption is observed due to the insulating layer material. As a result of intensive studies, the present inventors have found that the polyimide resin has excellent insulating properties and low power consumption performance.
In addition, in order to form the insulating layer thin film on the conductive support, the adhesion of the insulating layer material to the conductive support is required. As a result of intensive studies, the present inventors have found that if the insulating layer is composed of at least a polyimide resin, it has adhesiveness to the conductive support.

In general, it is extremely difficult to form a uniform and smooth thin film of micron level on the surface of a substrate. Therefore, a wet thin film formation process capable of forming a uniform and smooth thin film at the micron level is desired. However, a material that is soluble in an organic solvent has a structure such as a functional group that becomes soluble in an organic solvent. Power consumption increases.
Such contradictory functions are required. However, as a result of diligent efforts, the present inventors have been able to form a uniform and smooth thin film on the micron level because the polyimide-based resin is soluble in organic solvents, and has low power consumption. It was found that an insulating layer that realizes the above can be formed.

  The polyimide resin referred to in the present invention means a resin having a polyimide resin and a polyimide structure as a basic skeleton. Here, the polyimide is generally obtained by a condensation reaction between an aromatic polyvalent carboxylic acid anhydride or a derivative thereof and an aromatic diamine. Specifically, a polyamic acid (or polyamic acid to polyimide precursor) soluble in an organic solvent is first synthesized from an aromatic polycarboxylic acid anhydride and an aromatic diamine, and then dehydrated by heating or a chemical method. Polyimide is obtained by forming (imidization) (see Chemical Formula 1).

  Examples of the aromatic polycarboxylic acid anhydride include ethylene tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetra Carboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3 '-Biphenyltetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4- Dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis ( , 4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxylphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3, 6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3 4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8- Examples include phenanthrenetetracarboxylic dianhydride. These may be used alone or in combination of two or more.

  Examples of the aromatic diamine include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4,4′-diaminodiphenyl ether, and 3,3′-diamino. Diphenyl ether, 3,4'-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfide , (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3,3 '-Diaminobenzophenone, 3, '-Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis [4- (3-aminophenoxy) phenyl] methane Bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl]- Ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-amino Phenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3- Minophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4 -Aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, , 4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) ) Biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) pheny Ru] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] Ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4′-bis [3- (4- Aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) benzoyl] di Phenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy ] Diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy] -α, α-dimethylbenzyl] benzene, 1 , 3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, and the like. These are used individually or in mixture of 2 or more types.

  As the polyimide resin, polyimide silicone is marketed by Shin-Etsu Chemical Co., Ltd. Specifically, it is preferable to use a mixture of one or more of SMP-2003PGMEA Resin, SMP-5005PGMEA Resin, SMP-2006PGMEA Resin, etc. manufactured by Shin-Etsu Chemical Co., Ltd.

  The insulating layer can be formed by a common coating method using a suitable solvent. As the solvent, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, butyl carbitol acetate, or the like can be used. As the coating method, a dip coating method, a spray coating method, or the like can be used.

  The thickness of the insulating layer (95) depends on the material, but is preferably 1 μm or more and 100 μm or less, and more preferably 1 μm or more and 50 μm or less. If it is less than 1 μm, it is difficult to insulate so that no charge leakage occurs between the conductive support (91A) and the toner (T). If it is thicker than 100 μm, the electric field from the internal electrode becomes weak, and it is difficult for the toner (T) to separate from the surface layer (98) and to generate an electrostatic force that can be hopped.

(Surface layer)
The surface layer (98) covers the electrode (91Bb), and has a function of preventing leakage to the toner and the like and appropriately charging the toner by frictional charging with the toner. Therefore, the film thickness is 3 μm or more and 20 μm or less. It is preferable that By setting the surface layer (9c) to such a film thickness, the toner cloud is less likely to be unstable due to a decrease in the hopping electric field strength.
The surface layer (98) may be made of any material as long as it satisfies the above-mentioned functions. In particular, bisphenol-based polycarbonate provides both triboelectric charging and toner hopping, and can stably maintain a cloud of toner for a long period of time. The wear resistance can be improved.

  The molecular weight is preferably 30,000 to 60,000 from the viewpoint of ease of handling when dissolved in a solvent. If the molecular weight is too small, it is easy to work when preparing a coating solution, but the volume of the coating will be significantly reduced due to the rapid crystallization and molecular chain rearrangement of polycarbonate in the coated film of the already prepared photoreceptor. The desired endurance strength may be difficult to obtain.

The surface layer (98) may contain a leveling agent as an additive in the polycarbonate resin. When a leveling agent is contained, the content is suitably 0.001 to 1% by weight of the surface layer (98).
As the leveling agent, a known material can be used, but a silicone oil leveling agent capable of imparting a high level of smoothness in a trace amount is particularly preferable. Examples of silicone oils include dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen polysiloxane, cyclic dimethyl polysiloxane, alkyl-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, amino-modified Examples include silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, higher fatty acid-modified silicone oil, and higher fatty acid-containing silicone oil.
In addition, an appropriate amount of additives such as a plasticizer and an antioxidant can be added to the surface layer (98).

The surface layer (98) can be formed by a commonly used coating method such as a dip coating method or a spray coating method using one or more solvents in which a polycarbonate resin such as tetrahydrofuran is soluble.
The thickness of the surface layer (98) may be any as long as it can form an electric field curtain of toner on the surface of the toner carrier and can prevent the electrode electrode (91Bb) from being exposed to the surface of the toner carrier. It is preferably 5 μm or more and 50 μm or less. Below 0.5 μm, it is difficult to insulate so that no charge leakage occurs between the electrode (91Bb) and the toner. On the other hand, since the electric field from the internal electrode becomes weaker than 50 μm, it is difficult for the toner to be released from the surface layer (98) and to generate an electrostatic force that can be hopped. Further, when the thickness of the surface layer (98) is 5 to 50 μm, toner hopping is more stably performed.

  As described above, the present invention, as described above, has a great effect when applied to the upper and lower electrode application type toner carrier shown in FIG. 4, but the comb electrode application type toner carrier shown in FIG. It is possible to apply to, though the effect is small.

[Comb electrode application method]
The developing roller (9), which is a toner carrier, is shown in FIGS. 5A and 5B (note that FIG. 5A is a cross-sectional view taken along the line AA ′ in the top view of FIG. 5B). As shown, the first electrode pattern (9bA) having a plurality of linear electrodes (9bAa) and the second electrode pattern (9bB) having a plurality of linear electrodes (9bBb) are formed into electrodes (9bAa). And electrodes (9bBb) are alternately formed parallel to the axial direction of the developing roller.
In the developing roller (9) in this embodiment, a single-phase alternating voltage is used as the alternating voltage power supply, but a plurality of alternating voltage power supplies having different periods can also be used. In this case, as the electrode pattern (9b), a plurality of electrodes (9b) having different end lengths are formed adjacent to each other corresponding to the period, and a plurality of terminals connected at the end portions having the same length are attached. Alternatively, alternating voltages of different phases may be applied from each terminal. When such a plurality of alternating voltage power supplies having different periods are used, a traveling wave cloud can be formed.

  Formation of the electrode patterns (9bA) and (9bB) is desired by using a photoresist method from a copper thin film formed by evaporation on the peripheral surface of an insulating support (93) formed into a cylindrical shape having a rotation axis. It is possible by processing into the shape of In addition to patterning using a photoresist method, it may be formed by drawing using, for example, an ink jet apparatus. Moreover, there is no restriction | limiting in particular about the magnitude | size of an insulating support body (93), What is necessary is just to use what the practitioner of this invention selected suitably. Also, the width (d) of each of the electrode (9bAa), the electrode (9bBa), and the electrode (9bBb) and the distance (D) between the electrode (9bAa) and the electrode (9bBb) are not particularly limited. The practitioner may determine as appropriate.

However, even in the toner carrier using the comb electrode application method, the formation of the toner cloud is affected by the width (d), the interval (D), the alternating voltage, and the like. The electrode pattern (91Bb) preferably has an electrode width (d) and interval (D) of 40 μm to 250 μm and 85 μm to 500 μm, respectively. The thickness of the electrode of the electrode pattern (91Bb) is suitably about 0.1 μm to 20 μm. Moreover, as an alternating voltage, frequency 100Hz-5KHz and 100V-3KV are suitable.
The material constituting the electrode (9bAa) and the electrode (9bBb) is the same as that described for the upper and lower electrode applying type toner carrier.

(Insulating support)
As the insulating support (93), a cylindrical insulating support formed from a synthetic resin such as polyimide, polycarbonate, nylon, fluorine resin, polyacetal, phenol, polystyrene, or aluminum, aluminum alloy, nickel, A cylindrical metal conductive support (9a) obtained by cutting or polishing titanium, stainless steel, or the like, and coated with the synthetic resin can be used.

(Insulating layer, surface layer)
An insulating layer (95), an electrode (9bAa) and an electrode (9bBb), and a surface layer (98) are sequentially laminated on the insulating support (93). The insulating layer (95) and the surface layer (98) Is the same as that described for the upper and lower electrode application type toner carrier.

  EXAMPLES Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited by these examples, and these examples are appropriately modified without departing from the gist of the present invention. Is also within the scope of the present invention.

[Example 1]
(Preparation of coating solution for insulating layer)
100 parts by weight of polyimide resin (polyimide silicone SMP-2003PGMEA Resin, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 50 parts by weight of propylene glycol monomethyl ether acetate to prepare an insulating layer coating solution.
(Preparation of surface layer coating solution)
A mixture of 70 parts by weight of tetrahydrofuran and 30 parts by weight of cyclohexanone, 3 parts by weight of bisphenol Z-type polycarbonate resin (polymerized compound having a molecular weight of 50000 consisting of structural unit M-15: Panlite TS-2050, manufactured by Teijin Chemicals Ltd.), silicone oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.002 part by weight was dissolved to prepare a surface layer coating solution.

(Production of toner carrier)
On a cylindrical Al conductive support having a diameter of 16 mm and a length of 230 mm, spray coating was performed with the above insulating layer coating solution to form an insulating layer having a thickness of 20 μm. This is referred to as a support (91A) on which an insulating layer has been formed. A 0.8 μm-thick copper foil film, which is a conductive metal foil film, was formed on each support (91A) on which an insulating layer had been formed by vapor deposition. Further, a resist film having a thickness of 5 μm was applied on these copper foil films. A grid pattern separated by a width d = 100 μm, a length L = 200 mm, and a distance D = 200 μm on a support (91A) having an insulating layer covered with a copper film and a resist film was exposed with a laser drawing machine. Then, after developing in an aqueous Na ₂ CO ₃ solution, etching was performed by immersing in an aqueous FeCl ₃ solution to form an electrode (91Bb) having an electrode pattern (91B) having the same shape as the electrode pattern.
Next, one end of the electrode pattern (91B) of the support (91A) on which the insulating layer is formed in which the electrode having the predetermined electrode pattern (91B) is thus formed is masked to cover the maximum film thickness. A 10 μm surface layer (98) was formed by spray coating with the above surface layer forming coating solution. The surface layer (98) was applied with the electrode exposed at the end of the support (91A) on which the insulating layer had been formed.
The toner carrier (9) produced as described above and shown in FIG. 4 was assembled in the developing device (4).

[Example 2]
Instead of 100 parts by weight of the polyimide resin (polyimide silicone SMP-2003PGMEA Resin, manufactured by Shin-Etsu Chemical Co., Ltd.) of Example 1, 100 parts by weight of polyimide resin (polyimide silicone SMP-5005 PGMEA Resin, manufactured by Shin-Etsu Chemical Co., Ltd.) was used. Otherwise, a toner carrier (9) shown in FIG. 4 was produced in the same manner as in Example 1, and this was incorporated into the developing device (4).

Example 3
Instead of 100 parts by weight of the polyimide resin (polyimide silicone SMP-2003PGMEA Resin, manufactured by Shin-Etsu Chemical Co., Ltd.) of Example 1, 100 parts by weight of polyimide resin (polyimide silicone SMP-2006 PGMEA Resin, manufactured by Shin-Etsu Chemical Co., Ltd.) was used. 4 except that 50 parts by weight of propylene glycol monomethyl ether acetate was changed to 30 parts by weight, and a toner carrier (9) shown in FIG. 4 was prepared in the same manner as in Example 1, and this was placed in the developing device (4). Incorporated.

[Comparative Example 1]
Instead of the insulating layer coating solution of Example 1, 110 parts by weight of alkyd resin (Beckolite M6401-50 (manufactured by Dainippon Ink and Chemicals)), melamine resin (Super Becamine G-821-60, Dainippon) A toner carrier (9) shown in FIG. 4 is prepared in the same manner as in Example 1 except that an insulating layer coating solution in which 60 parts by weight of Ink Chemical Industries, Ltd. is dissolved in 110 parts by weight of methyl ethyl ketone is used. Was incorporated into the developing device (4).

[Comparative Example 2]
Except for using the surface layer coating solution of Example 1 instead of the insulating layer coating solution of Example 1, the insulating layer was formed by the same formation method as the surface layer forming method of Example 1, A toner carrier (9) shown in FIG. 4 was produced in the same manner as in Example 1, and this was incorporated into the developing device (4).

[Comparative Example 3]
Insulating layer coating prepared by dissolving 30 parts by weight of polyvinyl butyral resin (Eslex B BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 70 parts by weight of methyl ethyl ketone instead of the insulating layer coating liquid of Example 1. A toner carrier (9) shown in FIG. 4 was produced in the same manner as in Example 1 except that the liquid was used, and this was incorporated into the developing device (4).

[Evaluation]
(Conditions for applying voltage to electrodes)
An AC bias having an average potential of -200 V at each moment having a peak of -400 V and 0 V at a peak and a terminal attached to the opening of the developing device (4) and the conductive support was applied from an AC power source at a frequency of 5 KHz.
As a toner, BK color toner (wax-free pulverized toner) mounted on an image forming apparatus (image Neo Neo C320) manufactured by Ricoh was supplied to the developing device (4) and used.
These developing devices and toner are incorporated into an imagio Neo C320 black station to output an image, the power consumption of the developing device, the presence or absence of leakage between the conductive support and the electrode, the state of toner flying on the toner carrier, abnormal The presence or absence of image generation was compared.

  The measurement results and observation results of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1. As can be seen from Table 1, Examples 1 to 3 have less power consumption than Comparative Example 1. As for Comparative Examples 2 and 3, a phenomenon was observed in which the conductive support and the electrode leaked and became conductive when a voltage was applied to the electrode. Since no potential difference was generated between the conductive support and the electrode, no electric field was generated, and toner hopping did not occur on the surface of the toner carrier. The image could not be output.

Example 4
(Preparation of coating solution for insulating support)
In 60 parts by weight of 2-butanone, 30 parts by weight of alkyd resin and 20 parts by weight of melamine resin were dissolved to prepare a coating liquid for insulating support.

(Production of toner carrier)
An insulating support (9a) was produced by immersing a cylindrical aluminum tube having a diameter of 16 mm and a length of 230 mm in the above-mentioned coating solution for forming an insulating support and covering it with an insulating film having a thickness of 20 μm. On this insulating support (9a), the insulating layer coating liquid of Example 1 was spray-coated to form an insulating layer (95) having a thickness of 20 μm. Next, a 0.8 μm thick copper foil film, which is a conductive metal foil film, was formed on the insulating layer (95) by vapor deposition. Further, a resist film having a thickness of 5 μm was applied on the copper foil film. A plurality of linear electrodes (9bA) and (9bB) having a width (d) = 100 μm and a length (L) = 200 mm are spaced apart (D) on the insulating support (9a) covered with the copper foil film and the resist film. ) = electrode pattern is separated by 200μm to (9b) is exposed by a laser writing apparatus, subsequent to the development of _Na 2 CO ₃ aqueous solution, etched by immersion in FeCl ₃ aqueous solution, having an electrode pattern (9b) Electrodes (9bA) and (9bB) were formed.

  Next, the surface layer-forming coating of Example 1 is formed on the electrodes (9bA) and (9bB) provided on the insulating support (9a) on which the electrodes having the predetermined electrode pattern 9b are thus formed. The working liquid was applied so that the electrode shaft and the electrode shaft were exposed at both ends of the insulating support (9a), and a surface layer (9c) covering these electrodes (9bA) and (9bB) was formed to a thickness of 10 μm. The developing roller (9) produced as described above and shown in FIG. 5 was incorporated into the developing device (4).

Example 5
A toner carrier (9) shown in FIG. 5 was prepared in the same manner as in Example 4 except that the insulating layer coating liquid in Example 2 was used instead of the insulating layer coating liquid in Example 1. This was incorporated into the developing device (4).

Example 6
A toner carrier (9) shown in FIG. 5 was prepared in the same manner as in Example 4 except that the insulating layer coating liquid in Example 3 was used instead of the insulating layer coating liquid in Example 1. This was incorporated into the developing device (4).

[Comparative Example 4]
Instead of the insulating layer coating solution of Example 1, 110 parts by weight of alkyd resin (Beckolite M6401-50, manufactured by Dainippon Ink and Chemicals, Inc.), melamine resin (Super Becamine G-821-60, Dainippon Ink) (Chemical Industry Co., Ltd.) Insulating layer coating solution prepared by dissolving 60 parts by weight of methyl ethyl ketone in 110 parts by weight, and dip coating instead of spray coating of the insulating layer coating solution of Example 1 A toner carrier (9) shown in FIG. 5 was produced in the same manner as in Example 4 except that it was used, and this was incorporated into the developing device (4).

[Comparative Example 5]
Except for using the surface layer coating solution of Example 1 instead of the insulating layer coating solution of Example 1, the insulating layer was formed by the same formation method as the surface layer forming method of Example 1, A toner carrier (9) shown in FIG. 5 was produced in the same manner as in Example 4, and this was incorporated into the developing device (4).

[Comparative Example 6]
Insulating layer coating prepared by dissolving 30 parts by weight of polyvinyl butyral resin (Eslex B BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 70 parts by weight of methyl ethyl ketone instead of the insulating layer coating liquid of Example 1. A toner carrier (9) shown in FIG. 5 was prepared in the same manner as in Example 4 except that the liquid was used, and this was incorporated into the developing device (4).

[Evaluation]
AC bias at a frequency of 5 KHz with an average potential of -200 V by having -400V at one of the two terminals attached to the opening (8a) of the developing device (4) and 0V at the other as a peak. Applied from a power source. In this case, the AC bias of the odd-numbered electrode group (9bA) and the even-numbered electrode group (9bB) are in reverse phase.
The toner and the developing device output the image in the same manner as in Example 1, and the power consumption of the developing device, the presence or absence of leakage between the conductive support and the electrode, the state of toner flying on the toner carrier, the occurrence of abnormal images The presence or absence was compared.

  Table 2 shows the measurement results and observation results of Examples 4 to 6 and Comparative Examples 4 to 6. As seen in Table 2, it can be seen that Examples 4 to 6 consume less power than Comparative Example 4. As for Comparative Examples 2 and 3, a phenomenon was observed in which the conductive support and the electrode leaked and became conductive when a voltage was applied to the electrode. Since no potential difference was generated between the conductive support and the electrode, no electric field was generated, and toner hopping did not occur on the surface of the toner carrier. The image could not be output.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Exposure apparatus 4 Developing apparatus 5 Transfer roller 6 Cleaning apparatus 7 Fixing apparatus 7a Heating roller 7b Pressure roller 8 Container 8a Opening 9 Toner carrier (developing roller)
10 circulating paddle 11 toner regulating member 14 alternating current A rotating direction B conveying direction C rotating direction D interval T toner d width 56 two-component developer 57 magnet sleeve 59 alternating voltage 60 container 61 developer stirring device 62 developer stirring device 63 development Agent 90A Electrode pattern 90Aa Electrode 90B Electrode pattern 90Bb Electrode 91A Conductive support 91B Electrode 91Bb Electrode 93 Support 95 Insulating layer 98 Surface layer

JP-A-3-21967 JP 2007-133388 A JP 2010-217608 A

Claims (10)

  The toner carried on the toner carrying member is hopped by an electric field formed by a plurality of electrodes of the toner carrying member, and used for hopping development for developing an electrostatic latent image on the surface of the photoreceptor facing the toner carrying member. The toner carrier, which is a conductive or insulating support, an insulating layer formed on the support, a plurality of electrodes arranged at regular intervals on the insulating layer, And a surface layer covering the electrode, wherein the insulating layer is made of at least one polyimide resin.   The toner according to claim 1, wherein the support comprises a conductive support and constitutes one electrode, and a voltage is applied to the electrode and the plurality of electrodes serving as the other electrode. Carrier.   The support is an insulating support, and the plurality of electrodes are formed such that electrodes of a first electrode pattern and electrodes of a second electrode pattern are alternately formed in parallel, and the first electrode pattern The toner carrier according to claim 1, wherein a voltage is applied to the electrode and the electrode of the second electrode pattern.   4. The toner carrier according to claim 3, wherein the electrode of the first electrode pattern and the electrode of the second electrode pattern are arranged in a comb shape.   The toner carrying member according to claim 1, wherein the plurality of electrodes are arranged in a toner transport direction and generate an electric field.   6. The toner carrier according to claim 1, wherein the surface layer is made of a polycarbonate resin.   In a hopping developing device that hops toner carried on a toner carrier by an electric field formed by a plurality of electrodes of the toner carrier and develops an electrostatic latent image on the surface of the photoreceptor facing the toner carrier. A developing device, wherein the toner carrier is the toner carrier according to claim 1.   The developing device according to claim 7, wherein the toner carrier is disposed in a non-contact state having a space with the photoconductor and facing the photoconductor.   Electrostatic latent image forming means for forming an electrostatic latent image on a photoreceptor, and toner carried on the toner carrier are hopped by an electric field formed by a plurality of electrodes of the toner carrier, and the toner carrier 9. An image forming apparatus comprising a hopping developing means for developing an electrostatic latent image on the surface of a photoreceptor facing the body, wherein the hopping developing means is the developing apparatus according to claim 7 or 8. .   An electrostatic latent image forming step for forming an electrostatic latent image on the photosensitive member, and toner carried on the toner carrier are hopped by an electric field formed by a plurality of electrodes of the toner carrier, and the toner carrier An image forming method including a hopping development process for developing an electrostatic latent image on the surface of a photoreceptor facing the body, wherein the toner carrier is the toner carrier according to any one of claims 1 to 6. Image forming method.

Images