JP2015049322A - Developer, developer manufacturing method, developer container, developing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glossy developer having small particle size and causing no filming, a developer manufacturing method, a developer container housing the developer, a developing apparatus which uses the developer for development, and an image forming apparatus.SOLUTION: A developer is obtained by dispersing and granulating an oil phase component, which is formed by dispersing and granulating at least a binder resin and a mold-releasing agent in ethyl acetate, in an aqueous medium containing dispersants. The mold-releasing agent is paraffin wax having solubility of 1.7 to 2.2wt at 40°C with respect to the ethyl acetate, and having a melting point of 62 to 67°C.

Description

  The present invention relates to a developer, a developer manufacturing method, a developer container, a developing device, and an image forming apparatus, for example, a developer used in an electrophotographic printer, a developer manufacturing method, a developer container, and a developing device. The present invention can be applied to an apparatus and an image forming apparatus.

  For example, an electrophotographic image forming process includes a charging process for forming a uniform charge on the surface of the photoreceptor, an exposure process for forming an electrostatic charge image (electrostatic latent image) by irradiating the surface of the photoreceptor with light, A developing process in which a charged developer (toner) is attached to an electrostatic charge image to form a toner image on the photoreceptor, a transfer process in which the toner image is transferred to a recording medium such as paper, and the transferred toner image It consists of a series of processes such as a fixing process for fixing to a recording medium (see Patent Document 1).

JP 204-341122 A

  Incidentally, recent electrophotographic image forming apparatuses are required to increase the speed of image formation and to increase the definition of images. In order to increase the definition of an image, the developer is required to have a smaller particle diameter than conventional base material particles (hereinafter also referred to as toner base particles). Further, the developer is desired to prevent toner filming (hereinafter referred to as filming) in order to improve image quality. In particular, in clear toner, there is a demand for characteristics that do not cause filming and provide gloss.

  Therefore, in view of the above problems, the present invention has a smaller particle size than the prior art, does not cause filming, and has a glossy developer and developer production method, a developer container that contains the developer, It is an object of the present invention to provide a developing device and an image forming apparatus for developing using the developer.

  In order to solve such a problem, the first aspect of the present invention is to disperse an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed. In the developer obtained by granulation, the release agent has a solubility in ethyl acetate in the range of 1.7 wt% to 2.2 wt% at 40 ° C, and a melting point in the range of 62 ° C to 67 ° C. A developer characterized by being paraffin wax.

  The second aspect of the present invention includes at least a binder resin and a solubility in ethyl acetate at a range of 1.7 wt% to 2.2 wt% at 40 ° C, and a melting point of 62 ° C to 67 ° C. Prepare an oil phase component dissolved and dispersed in ethyl acetate using a paraffin wax as a mold release agent, disperse the dispersant in an aqueous medium to prepare an aqueous phase, and mix the oil phase component and the aqueous phase. A developer production method comprising producing a developer by dispersion granulation.

  According to a third aspect of the present invention, there is provided a developer container that contains a developer to be supplied to an electrostatic latent image carrier that carries an electrostatic latent image, wherein the developer includes at least a binder resin and a release agent in ethyl acetate. The oil phase component dissolved and dispersed in is dispersed and granulated in an aqueous medium in which a dispersant is dispersed. The release agent has a solubility in ethyl acetate of 1.7 wt% at 40 ° C. A developer container characterized by being a paraffin wax having a range of 2.2 wt% or less and a melting point of 62 ° C. or more and 67 ° C. or less.

  According to a fourth aspect of the present invention, in the developing device for forming an electrostatic latent image on the electrostatic latent image carrier using the developer supplied from the developer container, the developer includes at least a binder resin and a release agent. Is obtained by dispersing and granulating an oil phase component dissolved and dispersed in ethyl acetate in an aqueous medium in which a dispersing agent is dispersed. The release agent has a solubility in ethyl acetate of 40 ° C. The developing device is a paraffin wax having a range of 1.7 wt% to 2.2 wt% and a melting point of 62 ° C. to 67 ° C.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus for forming an image by transferring an electrostatic latent image formed on an electrostatic latent image carrier to a medium using a developer supplied from a developer container. Is obtained by dispersing and granulating an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed. An image forming apparatus characterized by being a paraffin wax having a solubility in ethyl acetate at a range of 1.7 wt% to 2.2 wt% at 40 ° C. and a melting point of 62 ° C. to 67 ° C. is there.

  According to the present invention, it is possible to provide a glossy developer having a smaller particle size than that of the prior art, without causing filming.

2 is a transmission electron microscope image of a toner cross section of Experimental Example 1. FIG. 4 is a transmission electron microscope image of a toner cross section of Experimental Example 2. 3 is a transmission electron microscope image of a toner cross section of Comparative Example 1. 6 is a transmission electron microscope image of a toner cross section of Comparative Example 3. 1 is a configuration diagram illustrating an internal configuration of an image forming apparatus according to a first embodiment. 1 is a configuration diagram illustrating a configuration of a developing device according to a first embodiment. FIG. 2 is a schematic configuration diagram illustrating an internal configuration of a toner cartridge of the developing device according to the first embodiment. FIG. 3 is an enlarged view of a main part schematically illustrating a configuration of a developing unit of the developing device according to the first embodiment. FIG. 3 is a schematic configuration diagram illustrating a configuration of a fixing unit according to the first embodiment.

(A) First Embodiment Hereinafter, a developer, a developer manufacturing method, a developer container, a developing device, and an image forming apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings. .

  The first embodiment exemplifies a case where the present invention is applied to a color electrophotographic printer using a developer (toner) produced by a dissolution suspension method. The image forming apparatus of the present invention is not limited to a printer, and can be widely applied to image forming apparatuses such as copying machines and facsimile machines.

(A-1) Configuration of First Embodiment (A-1-1) Configuration of Image Forming Apparatus FIG. 5 is a configuration diagram showing an internal configuration of the image forming apparatus 10 according to the first embodiment. In FIG. 5, the image forming apparatus 10 includes a medium storage cassette 11, developing devices 31, 32, 33 and 34, a transfer unit 16, and a fixing unit 40. Furthermore, the image forming apparatus 10 includes transport rollers 45 a to 45 x and transport path switching guides 41 and 42 for transporting the medium 50 from the medium storage cassette 11 to each component.

  The medium storage cassette 11 stores a medium 50 such as a recording sheet in a stacked state. For example, the medium storage cassette 11 is detachably attached to a lower portion in the image forming apparatus 10. The medium transport rollers 45a and 45b feed the medium 50 stored in the medium storage cassette 11 one by one from the top, and transport the medium 50 in the direction of the arrow (l). The transport rollers 45 c and 45 d and the transport rollers 45 e and 45 f correct the skew of the medium 50 while feeding the medium 50 along the arrow (e), and send the medium 50 to the image forming unit 30.

  The image forming unit 30 forms an image on the conveyed medium 50. The image forming unit 30 receives toner images formed by the four developing devices 31, 32, 33, and 34 that are detachably disposed along the medium conveyance path, and the developing devices 31, 32, 33, and 34, respectively. A transfer unit 16 is provided on the upper surface of the medium 50 for transferring by Coulomb force.

  The developing devices 31, 32, 33, and 34 are arranged in order along the medium conveyance path, and perform development processing using an electrostatic charge developing toner described later. Although the detailed description of the configuration of the four developing devices 31, 32, 33, and 34 will be described later, the four developing devices 31, 32, 33, and 34 all have the same configuration, and the color of the toner to be used is the same. Different.

  In the first embodiment, the developing devices 31, 32, 33, and 34 use yellow (Y), magenta (M), cyan (C), and clear (CL) toners, respectively. When black is expressed above, black is expressed by mixing three colors of yellow (Y), magenta (M), and cyan (C). The number of developing devices 31, 32, 33, and 34 is not limited to four, and may be one in the case of a monochrome printer, or may be two or more. Further, for example, in addition to the four developing devices 31, 32, 33 and 34 in FIG. 5, a developing device using black (K) toner may be further arranged.

  The transfer unit 16 is paired with a transfer belt 17 that electrostatically attracts and conveys the medium 50, a drive roller 18 that receives the rotational force from the drive unit and drives the transfer belt 17, and the drive roller 18, for example. A tension roller 19 that stretches the transfer belt 17 and the photosensitive drums 101 (see FIG. 6) of the developing devices 31, 32, 33, and 34 are arranged so as to be in pressure contact with each other and transfer the toner image to the medium 50. The transfer rollers 20 to 23 for applying a voltage to the transfer belt, the toner adhering to the transfer belt 17 is scraped off, the transfer belt cleaning blade 24 for cleaning the surface of the transfer belt 17, and the toner scraped off by the transfer belt cleaning blade 24 are removed. And a toner box 25 to be deposited.

(A-1-2) Configuration of Developing Device FIG. 6 is a configuration diagram showing the configuration of the developing device 34 according to the first embodiment. FIG. 6 illustrates the configuration of the developing device 34 that uses clear (CL) toner as a representative of the developing devices 31, 32, 33, and 34.

  In FIG. 6, the developing device 34 includes a developing unit 100 and a toner cartridge 120 as a developer container. The developing device 34 is detachably mounted at a predetermined position of the image forming apparatus 10 (see FIG. 5), and the toner cartridge 120 is detachably mounted on the developing unit 100.

  FIG. 7 is a schematic configuration diagram illustrating an internal configuration of the toner cartridge 120 of the developing device 34 according to the first embodiment.

  In FIG. 7, the toner cartridge 120 includes a toner storage unit 125, a stirring bar 122, a shutter 123, and a discharge port 124 in the container main body 121.

  The toner cartridge 120 is provided so as to be detachable from the image forming apparatus 10 with the front and back directions in FIG. 7 as the longitudinal direction.

  The toner storage part 125 has a storage part partitioned in the container main body 121, and the electrostatic charge developing toner described later is stored in this storage part. This electrostatic charge developing toner is prepared by a dissolution suspension method as described later, and includes a binder resin containing a polyester resin modified with a long-chain alkyl group to improve hydrophobicity, and an organic solvent. It contains a mold release agent having a solubility in a certain ethyl acetate at a range of 1.7 wt% to 2.2 wt% at 40 ° C and a melting point of 62 ° C to 67 ° C.

  The agitation bar 122 is an example of an agitation member, and agitates the toner 110 in the toner storage unit 125 in order to prevent the toner 100 in the toner storage unit 125 from solidifying or unevenly distributed. The stirring bar 122 extends in the longitudinal direction of the toner cartridge 120 at a predetermined position in the toner storage unit 125 and is rotatably supported. The stirring bar 122 rotates in the directions of arrows (t) and (u) in FIG.

  The discharge port 124 is an opening provided in a lower portion of the container main body 121 and discharges the toner 110 toward the developing unit 100.

  The shutter 123 is an example of an opening / closing member of the discharge port 124, and is slidable in the direction of the arrow (s) in order to open / close the opening of the discharge port 124.

  FIG. 8 is an enlarged view of a main part schematically showing the configuration of the developing unit 100 of the developing device 34 according to the first embodiment.

  In FIG. 8, the developing unit 100 includes a photosensitive drum 101, a charging roller 102, an LED head 103, a developing roller 104, a supply roller 106, a developing blade 107, and a cleaning blade 105.

  The photosensitive drum 101 is an example of an electrostatic latent image carrier, and forms a toner image by attracting the toner 110 from the supply roller 106 to the electrostatic latent image formed by the LED head 103. After the toner image is formed, the photosensitive drum 101 transfers the toner image to the medium 50 on the transfer belt 17 between the photosensitive drum 101 and the transfer roller 20. The photosensitive drum 101 includes, for example, a conductive support and a photoconductive layer. Specifically, the photosensitive drum 101 is an organic photoreceptor having a structure in which a charge generation layer and a charge transport layer as a photoconductive layer are sequentially laminated on an aluminum metal pipe as a conductive support.

  The charging roller 102 is an example of a charging device, is provided in contact with the peripheral surface of the photosensitive drum 101, and charges the surface of the photosensitive drum 101. The charging roller 102 is composed of a metal shaft and a semiconductive shrimp chlorohydrin rubber layer.

  The LED head 103 is an example of an exposure device, and exposes the photosensitive drum 101. The LED head 103 includes, for example, an LED element and a lens array, and the irradiation light output from the LED element forms an image on the surface of the photosensitive drum 101.

  The developing roller 104 is an example of a developer carrying member, and carries the toner 110 supplied from the supply roller 106 and transfers the toner 110 to the electrostatic latent image on the surface of the photosensitive drum 101. The developing roller 104 is constituted by, for example, a metal shaft and a semiconductive urethane rubber layer.

  The supply roller 106 is an example of a developer supply body, and supplies toner 110 as a developer to the developing roller 104 that is in sliding contact. The supply roller 106 is composed of, for example, a metal shaft and a semiconductive foamed silicon sponge layer.

  The toner 110 as the developer is produced by a melt suspension method and uses a polyester resin as a binder resin. The toner 110 includes a polyester resin, a charge control agent as an internal additive, and a release agent. In addition, the toner 110 may be subjected to an external addition process on the surface of the toner in order to improve the fluidity of the toner and the image quality. For example, the toner 110 may contain silica part particles as an external additive.

  The developing blade 107 is an example of a developer regulating member, and regulates the thickness of the toner 110 layer on the surface of the supply roller 106. The developing blade 107 is disposed in a state where the tip end portion of the blade is separated from the supply roller 106 by a predetermined distance. As the developing blade 107, for example, a metal blade such as stainless steel can be used.

  The cleaning blade 105 is an example of a developer collecting member, and is disposed in pressure contact with the surface of the photosensitive drum 101, and collects the toner 110 remaining on the surface of the photosensitive drum 101 after the transfer of the toner image. For example, a member made of urethane rubber can be used for the cleaning blade 105.

  In FIG. 5, the medium 50 on which the toner image of each color is transferred by the image forming unit 30 is conveyed in the direction of the arrow (h) and sent to the fixing unit 40.

  The fixing unit 40 fixes the toner image on the medium 50 by pressing and heating.

  FIG. 9 is a schematic configuration diagram illustrating a configuration of the fixing unit 40 according to the first embodiment. In FIG. 9, the fixing unit 40 according to the embodiment includes a heat roller 141, a pressure roller 144, a thermistor 143, and a heater 142.

  The heat generating roller 141 is formed by, for example, covering a hollow cylindrical cored bar made of aluminum or the like with a heat-resistant elastic layer of silicone rubber, and a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube on the heat-resistant elastic layer. It is formed by coating. Further, a heater 142 (here, a halogen lamp) is disposed in the cored bar of the heat roller 141.

  The pressure roller 144 is configured, for example, by covering a core metal such as aluminum with a heat-resistant elastic layer of silicone rubber and covering the heat-resistant elastic layer with a PFA tube. The pressure roller 144 is disposed so that a pressure contact portion is formed between the pressure roller 144 and the heat generating roller 141.

  The thermistor 143 is means for detecting the surface temperature of the heat generating roller 141. The thermistor 143 is disposed in the vicinity of the heat generating roller 141 in a non-contact manner. The temperature information detected by the thermistor 143 is sent to, for example, a temperature control unit of the image forming apparatus 10 and used for temperature control. Accordingly, the heater 142 can be controlled on / off based on the temperature information detected by the thermistor 143, and the surface temperature of the heat roller 141 can be maintained at a predetermined temperature.

(A-1-3) Image Forming Process Next, an image forming process of the image forming apparatus 10 according to the first embodiment will be described. Here, the development process will be described first.

  As shown in FIG. 8, the photosensitive drum 101 is rotated at a constant peripheral speed in the direction of arrow (a) by driving means such as a motor. The charging roller 102 is provided in contact with the surface of the photosensitive drum 101. The charging roller 1-2 applies a DC voltage supplied from, for example, a high voltage power supply for the charging roller to the surface of the photosensitive drum 101 while rotating in the direction of the arrow (d), and uniformly charges the surface of the photosensitive drum 101. Let

  Next, the LED head 103 provided facing the photosensitive drum 101 irradiates light corresponding to the image signal onto the uniformly and uniformly charged surface of the photosensitive drum 101, and light attenuates the potential of the light irradiation portion. To form an electrostatic latent image.

  On the other hand, when the toner cartridge 120 shown in FIG. 7 is attached to the developing unit 100, the shutter 123 slides in the opening direction by, for example, a lever operation, and the opening is formed as shown in FIG. As a result, the toner 110 in the toner storage unit 125 falls in the direction of the arrow (v) from the discharge port 124, and the toner 110 is supplied to the developing unit 100.

  In FIG. 8, a voltage is applied to the supply roller 106 by, for example, a high-voltage power supply for the supply roller, and the supply roller 106 rotates in the direction of arrow (c), whereby the toner 110 is supplied to the developing roller 104.

  The developing roller 104 is disposed in close contact with the photosensitive drum 101, and a voltage is applied, for example, by a high voltage power supply for the developing roller. The developing roller 104 attracts the toner 110 conveyed by the supply roller 106 and rotates and conveys the toner 110 in the direction of arrow (b). Here, the developing blade 107 is disposed downstream of the supply roller 106 and in pressure contact with the developing roller 104. The developing blade 107 forms a toner layer that equalizes the toner 110 adsorbed to the developing roller 104 to a uniform thickness.

  Further, the developing roller 104 reverses the electrostatic latent image formed on the photosensitive drum 101 by the toner 110 carried as follows. Since a bias voltage is applied between the conductive support of the photosensitive drum 101 and the developing roller 104 by a high-voltage power supply, a static voltage formed on the photosensitive drum 101 is provided between the developing roller 104 and the photosensitive drum 101. Electric lines of force are generated along with the electrostatic latent image. Therefore, the charged toner 110 on the developing roller 104 adheres to the electrostatic latent image portion on the photosensitive drum 101 by electrostatic force, and this portion is developed to form a toner image. The above development process starting from the start of rotation of the photosensitive drum 101 is started at a predetermined timing described later.

  In FIG. 5, the medium 50 stored in the medium storage cassette 11 is taken out from the medium storage cassette 11 one by one in the direction of the arrow (l) by the medium transport rollers 45a and 45b as described above.

  Thereafter, the medium 50 is transported in the arrow (e) direction by the medium transport rollers 45c and 45d and the medium transport rollers 45e and 45f. At this time, since the medium 50 is conveyed along the medium guide, the medium 50 is conveyed while correcting skew. Then, the medium 50 is sent to the transfer belt 17 that rotates in the arrow (f) direction by the drive roller 18 that rotates in the arrow (g) direction. The development process described above is started at a predetermined timing while the medium 50 is conveyed in the direction of the arrow (e).

  Next, as shown in FIG. 9, a transfer process is performed. The transfer roller 20 is disposed in pressure contact with the photosensitive drum 101 of the developing device 31 via the transfer belt 17. Further, a voltage is applied to the transfer roller 20 by, for example, a high-voltage power supply for the transfer roller.

  The medium 50 is conveyed by electrostatic attraction by the transfer belt 17. The transfer belt 20 transfers the yellow toner image formed on the surface of the photosensitive drum 101 by the development process described above onto the medium 50.

  Since the medium 50 is conveyed on the transfer belt 17 along the arrow (f), processes similar to the development process and the transfer process are performed in the order of yellow, magenta, cyan, and transparent. That is, the yellow toner image is transferred by the developing device 31 and the transfer roller 20, the magenta toner image is transferred by the developing device 33 and the transfer roller 21, and then the cyan toner image is transferred by the developing device 33 and the transfer roller 22. The clear toner images are sequentially transferred onto the medium 50 by the developing device 34 and the transfer roller 23. The medium 50 on which the toner image of each color is transferred is conveyed in the direction of the arrow (h).

  Next, the fixing process will be described. As shown in FIG. 9, the medium 50 on which the toner images of the respective colors are transferred is conveyed in the direction of the arrow (h), and is conveyed to the fixing unit 40 that includes the heat roller 141 and the pressure roller 144.

  The heat generating roller 141 of the fixing unit 40 is maintained at a predetermined surface temperature, for example, under the control of a temperature control unit. Then, the medium 50 on which the toner image is transferred is conveyed between the heat roller 141 that rotates in the direction of arrow (i) and the pressure roller 144 that rotates in the direction of arrow (j). Therefore, the heat of the heat generating roller 141 melts the toner image on the medium 50, and the pressure contact portion between the heat generating roller 141 and the pressure roller 142 pressurizes the melted toner image on the medium 50, thereby recording the toner image. Fix to paper 50.

  The recording paper 50 on which the toner image is fixed is conveyed in the direction of the arrow (k) by the medium conveying rollers 45g and 45h and the medium conveying rollers 45i and 45j shown in FIG. Is sent to.

  Next, the cleaning process will be described. As shown in FIG. 8, even after the transfer, some toner 110 may remain on the surface of the photosensitive drum 101. The residual toner 110 is removed by the cleaning blade 105.

  The cleaning blade 105 is arranged in parallel along the rotation axis direction of the photosensitive drum 101 extending in the longitudinal direction (front and back direction in FIG. 8). The base of the cleaning blade 105 is fixed to a rigid support substrate so that the tip of the cleaning blade 105 contacts the surface of the photosensitive drum 101.

  When the photosensitive drum 101 rotates around the rotation axis with the tip of the cleaning blade 105 in contact with the peripheral surface of the photosensitive drum 101, the residual toner on the surface of the photosensitive drum 101 that remains without being transferred. 110 is removed. The photosensitive drum 101 thus cleaned is repeatedly used.

  Further, in the image forming apparatus 10 shown in FIG. 5, a part of the poorly charged toner is transferred to the transfer belt 17 from the photosensitive drum 101 (see FIG. 8) of each of the developing devices 31 to 34 at the time of continuous paper passing. May be transcribed. However, the toner transferred to the transfer belt 17 is removed from the transfer belt 17 by the transfer belt cleaning blade 24 and transferred to the toner box 25 when the transfer belt 17 rotates in the directions of arrows (f) and (r). Stored as poorly charged toner. The transfer belt 17 thus cleaned is repeatedly used.

  Note that the medium transport rollers 45k to 45x and the transport path switching guides 41 and 42 shown in FIG. 5 transport the medium 50 and guide the transport direction when performing double-sided printing. The description is omitted here because it is not related.

(A-1-4) Electrostatic Charge Developing Toner Next, the electrostatic charge developing toner 100 according to the first embodiment will be described with reference to the drawings.

  The electrostatic charge developing toner 100 according to this embodiment contains toner mother particles produced by a dissolution suspension method. That is, the toner 100 according to this embodiment includes an oil phase in which at least a binder resin (binder resin) and an additive are dissolved and dispersed in an organic solvent, and an aqueous phase in which inorganic fine particles as a dispersant are dispersed in an aqueous solvent. Are mixed and suspended to produce oil phase droplets with inorganic fine particles attached to the surface of the oil phase droplets, and then the toner is prepared by removing the solvent and adding the acid to remove the inorganic fine particles. Contains particles.

[Binder resin]
The binder resin used in the toner 100 according to the first embodiment is a polyester resin in which a long-chain alkyl group having a structure represented by the following chemical formula (1) is modified to improve hydrophobicity. As the binder resin, a polyester resin modified with the following long-chain alkyl group may be used alone, or may be combined with other resins.

  The polyester resin that is a binder resin can be produced by condensation polymerization of an alcohol component and a carboxylic acid component.

  The toner 100 according to this embodiment can use polyester obtained by condensation polymerization of an alcohol component and a carboxylic acid component.

  Examples of the alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, xylene glycol, dipropylene glycol, polypropylene glycol, bisphenol A, hydrogenated Examples thereof include divalent or higher alcohols such as bisphenol A, bisphenol A ethylene oxide, bisphenol A propylene oxide, sorbitol, and glycerin, alcohol derivatives, and the like.

  Examples of the carboxylic acid component include maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, trimellitic acid, pyromellitic acid, cyclopentanedicarboxylic acid, succinic anhydride, trimellitic anhydride , Divalent or higher carboxylic acids such as maleic anhydride and dodecenyl succinic anhydride, carboxylic acid derivatives, succinic anhydride and the like.

  In addition, two or more types of alcohol components and carboxylic acid components may be combined.

[Colorants, etc.]
As the colorant blended in the binder resin, known pigments and dyes can be widely used in accordance with the color of the toner (for example, black color, yellow color, magenta color, cyan color, etc.).

  As the black colorant, for example, carbon black such as furnace black and channel black can be used. Examples of the yellow colorant include C.I. I. Pigment yellow 74, cadmium yellow, or the like can be used. Examples of the magenta colorant include C.I. I. Pigment Red 238 or the like can be used. As the cyan colorant, pigment blue 15: 3 or the like can be used.

  The clear toner is used to adhere to colored toner or to a recording medium such as paper in order to obtain gloss. Therefore, the clear toner is configured so that the colored toner can be visually recognized when attached to the colored toner, or the recording medium can be visually recognized when attached to the recording medium. When producing a clear toner, a fluorescent brightening agent may be blended without blending a colorant. The clear toner is externally added with inorganic fine particles (for example, silicon dioxide, titanium dioxide, etc.) as an external additive.

[Organic solvent]
A common organic solvent can be used for the organic solvent used when producing an oil phase. Examples of the organic solvent include esters such as methyl acetate, ethyl acetate, and butyl acetate. Examples of the organic solvent include hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride, chloroform and dichloroethane, alcohols such as methanol and ethanol, and ketones such as acetone, methyl ethyl ketone and cyclohexanone. Two or more organic solvents may be mixed and used.

  In 1st Embodiment, the case where ethyl acetate is used as an organic solvent is illustrated. Since this employs the melt suspension method, the oil phase is charged and suspended in the aqueous phase to form particles, and then the oil phase is selectively evaporated and removed. Therefore, an organic solvent having a boiling point lower than that of water, which is a water phase solvent, and having a relatively low solubility in water is preferable as the organic solvent. In this embodiment, ethyl acetate is used as the organic solvent.

[Release agent]
The release agent is for improving the fixing property and offset resistance of the toner. Examples of the releasing agent include petroleum waxes such as paraffin wax and acid value paraffin wax, synthetic waxes such as polyolefin wax and acid value polyolefin wax, ester waxes, ether waxes, waxes derived from animals and plants, and the like.

  In 1st Embodiment, the case where paraffin wax is used as a mold release agent is illustrated. In the first embodiment, since ethyl acetate is used as the organic solvent, it is possible to use an ester wax in order to improve the hydrophobicity of the polyester resin that is relatively soluble in ethyl acetate and the binder resin. . However, ester wax has a larger average molecular weight than paraffin wax and has a high viscosity when melted. For this reason, when ester wax is used as the release agent for the clear toner, it may be difficult to be uniform on printing, resulting in slightly dull printing. As a result, the print quality is lowered and the gloss is also lowered. Therefore, in the first embodiment, paraffin wax having an average molecular weight smaller than that of ester wax and having a low viscosity at the time of melting is used as a release agent.

[Aqueous medium]
As the aqueous medium for producing the aqueous phase, water is mainly used. The aqueous medium may be a mixture of water and a water-soluble solvent.

[Dispersant]
As the suspension stabilizer as a dispersant, inorganic fine particles can be used. Examples of the suspension stabilizer include tricalcium phosphate, hydroxyapatite, calcium carbonate, titanium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, and silica.

(A-2) Preparation of toner for developing electrostatic charge according to first embodiment The following was prepared by giving a plurality of experimental examples and comparative examples for producing toner for developing electrostatic charge according to the first embodiment. To compare the melting characteristics and particle size distribution of the toner, the evaluation results of filming and gloss with the produced toner, and the like.

  Further, the following experimental examples and comparative examples illustrate the case where the toner base particles of the clear toner are produced by employing the melt suspension method.

  As described above, the melt suspension method includes (a) an aqueous phase preparation step for preparing an aqueous medium in which a dispersant (inorganic dispersant) is dispersed, and (b) a binder resin and a release agent are added to an organic solvent. An oil phase adjustment step for preparing the oil phase, (c) a particle formation step for forming the particles by adding and suspending the oil phase to the aqueous phase, and (d) after dehydrating the particles in the liquid, A toner base particle forming step in which the acid is washed to dissolve the suspension stabilizer, the acid is washed again, and dried to form toner base particles. (E) An external additive is attached to the generated toner base particles. It consists of an external addition process.

  As described above, as the binder resin, a polyester resin in which the long-chain alkyl group having the structure of the chemical formula (1) is modified to improve hydrophobicity is used. Ethyl acetate is used as the organic solvent.

  As the release agent, a paraffin wax having an average molecular weight smaller than that of the ester wax and having a lower viscosity at the time of melting than the ester wax is used.

  Here, regarding the production of the clear toner, in order to obtain gloss characteristics, it is preferable to use a paraffin wax having a lower viscosity at the time of melting than an ester wax as a release agent. However, paraffin wax has low solubility in ethyl acetate, which is an organic solvent, and hardly dissolves. Therefore, for example, there is a method in which paraffin wax is pulverized to about several hundred nm using a disperser such as a bead mill and then paraffin wax is mixed with ethyl acetate.

  However, it is very difficult to pulverize all the paraffin wax to about several hundred nanometers, and if it cannot be finely pulverized, paraffin wax is mixed as coarse particles in the toner and filming occurs. Sometimes. In addition, since a long dispersion process is required to pulverize all the paraffin wax to about several hundreds of nanometers, the burden associated with the production of the clear toner is large, which may significantly deteriorate the production efficiency. is there.

  Therefore, as described below, a clear toner that obtains the glossiness of the clear toner and does not cause filming is produced.

[Experimental Example 1]
(A) Aqueous phase adjustment step First, as a step of obtaining an aqueous medium in which an inorganic dispersant is dispersed, 11110 parts by weight of industrial trisodium phosphate dodecahydrate is mixed with 37680 parts by weight of pure water, and the liquid temperature is 60. After dissolving at 0 ° C., dilute nitric acid for pH adjustment is added. Thereto, an aqueous calcium chloride solution in which 540 parts by weight of industrial calcium chloride anhydride was dissolved in 4360 parts by weight of pure water was added, and the temperature was kept at 60 ° C. at 4300 rpm with Neomixer (manufactured by Primix Co., Ltd.). While stirring for 34 minutes, an aqueous phase containing a suspension stabilizer (dispersant) is prepared.

(B) Oil phase adjustment process Next, the preparation method of the oil phase containing the polyester resin which has a structure of Chemical formula (1) is demonstrated.

5300 parts by weight of ethyl acetate as an organic solvent is heated and stirred at a liquid temperature of 50 ° C., and 56 parts by weight of paraffin wax (SP-0145 melting point: 62 ° C.) is added.

  Table 1 shows the melting point of the release agent used in the first embodiment and the solubility (wt%) in ethyl acetate at 40 ° C. In Table 1, the paraffin wax (paraffin wax A) of Experimental Example 1 has a melting point of 62 ° C. and a solubility in ethyl acetate of 2.2 wt%.

  The paraffin wax of Experimental Example 1 had better solubility in ethyl acetate than ordinary paraffin wax, and the paraffin wax dissolved within a few minutes after the paraffin wax was charged. After dissolving the paraffin wax, 1 part by weight of the charge control resin is sequentially added to the solvent.

  Then, 1090 parts by weight of a polyester resin having a structure of the chemical formula (1) modified with a long-chain alkyl group to increase hydrophobicity, an acid value of 6.3 mg KOH / g, and a glass transition temperature (Tg) of 71 ° C. The oil phase is prepared by stirring until there is no solid matter.

  Here, it is preferable to use the polyester resin prepared so that the acid value becomes low, for example, 4.9 mgKOH / g or more and 7.2 mgKOH / g or less, and in the first embodiment, the acid value of the polyester resin is used. Is 6.3 mg KOH / g. The acid value is the weight of potassium hydroxide necessary to neutralize 1 g of resin.

  The reason for reducing the acid value of the polyester resin will be described. The melt suspension method is preferable because it makes it easy to control the particle size of the toner, but some of the inorganic dispersant is taken into the oil phase droplets, and even if an acid is added, the inorganic fine particles cannot be removed. Inorganic fine particles may remain in the toner. As a result, the hygroscopicity of the toner is increased by the inorganic fine particles contained in the toner, so that the storage stability of the toner can be deteriorated. In a high-temperature and high-humidity environment, the toner charge decreases due to the moisture absorption of the toner, and stains on the printed matter such as “fogging” may occur. One of the causes of the incorporation of the inorganic fine particles is that inorganic fine particles (for example, calcium or magnesium phosphate and functional groups such as carboxyl groups present on the surface of the polyester resin are ionically bonded. Therefore, by reducing the functional groups on the surface of the polyester resin, that is, by reducing the acid value of the polyester resin, the number of ion binding sites is reduced and the suspension stabilizer is prevented from being taken in. .

  Various methods can be applied to the method for preparing the acid value of the polyester resin. For example, increasing the acid value of the polyester resin can be realized by increasing the ratio of the “carboxylic acid component” among the “alcohol component” and the “carboxylic acid component” that are raw materials of the polyester resin. Conversely, the acid value of the polyester resin can be reduced by reducing the ratio of the “carboxylic acid component”.

  Moreover, as an acid value preparation method other than the above, there is a method of adjusting the acid value of the polyester resin according to the polymerization time, for example, when the raw material composition of the polyester resin is the same. For example, when the polymerization time is short, the acid value of the polyester resin increases, and when the polymerization time is long, the acid value of the polyester resin tends to decrease. This characteristic can be used to adjust the acid value of the polyester resin.

(C) Particle formation step Next, the liquid temperature of the aqueous phase is kept at 60 ° C., the oil phase is dropped into the liquid phase, and the mixture is stirred at high speed for 10 minutes at 1700 rpm with a Neomixer (Primix Co., Ltd.). To form particles. Thereafter, ethyl acetate was removed by distillation under reduced pressure.

(D) Toner mother particle forming step After the toner in the liquid is once dehydrated, the dehydrated toner is re-dispersed in pure water, nitric acid is added to adjust the pH to 1.5 or less, and the resultant is washed with an acid to be suspended. Dissolve tricalcium phosphate, a stabilizer. Again, acid cleaning is performed using nitric acid. Further, the dehydrated toner is redispersed in pure water, stirred, and washed with water. Thereafter, the toner is dehydrated and dried to produce the toner.

(E) External Addition Step Next, as an external addition step, 100 parts by weight of the produced toner is added with 1.0 part by weight of hydrophobic silica RX50 (manufactured by Nippon Aerosil Co., Ltd., average primary particle size 40 nm), and hydrophobic silica RX200 (Japan Aerosil). A toner is obtained by adding 0.8 parts by weight of an average primary particle size of 12 nm, manufactured by the company, and stirring for 10 minutes at a rotation speed of 5400 rpm with a 10 liter Henschel mixer.

[Experiment 2]
In Experimental Example 2, paraffin wax (Nippon Seiwa Co., Ltd., PARACOHOL-6150, melting point: 67 ° C.) was used as a release agent. The other conditions are the same as in Experimental Example 1. Further, the toner production process is the same as that in Experimental Example 1.

  In Table 1, the paraffin wax (paraffin wax B) of Experimental Example 2 has a melting point of 67 ° C. and a solubility in ethyl acetate of 1.7 wt%.

  In the oil phase preparation step, when the paraffin wax of Experimental Example 2 is added to ethyl acetate, the paraffin wax of Experimental Example 2 has better solubility in ethyl acetate than ordinary paraffin wax. The paraffin wax was completely dissolved in a few minutes.

[Comparative Example 1]
In Comparative Example 1, paraffin wax (Nippon Seiwa Co., Ltd. Paraffin Wax-120, melting point 50 ° C.) was used as a release agent. The other conditions are the same as in Experimental Example 1. Further, the toner production process is the same as that in Experimental Example 1.

  In Table 1, the paraffin wax (paraffin wax C) of Comparative Example 1 has a melting point of 50 ° C. and a solubility in ethyl acetate of 2.5 wt%.

  In the oil phase preparation step, the paraffin wax of Comparative Example 1 also had better solubility in ethyl acetate than the normal paraffin wax, and the paraffin wax was completely dissolved within a few minutes after the paraffin wax was charged.

[Comparative Example 2]
In Comparative Example 2, a paraffin wax (Nippon Seiwa Co., Ltd. HNP-9 melting point: 75 ° C.) insoluble in ethyl acetate was used as a release agent.

  In Table 1, the paraffin wax (paraffin wax D) of Comparative Example 2 has a melting point of 75 ° C. and is insoluble in ethyl acetate.

  In the oil phase preparation step, the particle size of the paraffin wax of Comparative Example 2 was pulverized to about several hundred nm using a bead mill disperser (manufactured by Imex Corporation), and then the pulverized paraffin wax of Comparative Example 2 was ethyl acetate. Dispersed.

  The other conditions are the same as in Experimental Example 1. Further, the toner production process is the same as that in Experimental Example 1.

[Comparative Example 3]
In Comparative Example 3, an ester wax (NOF CORPORATION, melting point 71 ° C.) was used as a release agent. The other conditions are the same as in Experimental Example 1. Further, the toner production process is the same as that in Experimental Example 1.

  In Table 1, the ester wax of Comparative Example 4 has a melting point of 71 ° C. and a solubility in ethyl acetate of 4.5 wt%.

  In the oil phase preparation step, the ester wax of Comparative Example 3 had good solubility in ethyl acetate, and the ester wax was completely dissolved within a few minutes after the ester wax was added.

[Method for measuring acid value of polyester resin]
The acid value of the polyester resin is measured using a measuring device DL-58 (manufactured by METLER TOLEDO) and an electrode DGl13, weighing about 0.5 to 0.6 g of the sample in a screw tube, and adding a mixed solvent to dissolve it. It measured by potentiometric titration with 0.01 mol / l potassium hydroxide-ethanol solution.

[Toner melting characteristics]
The melting characteristics of the toner were measured with a measuring apparatus flow tester (CFT-500D manufactured by Shimadzu Corporation). As melting characteristics of the toner, glass transition temperature (Tg), outflow start temperature (Tfb), and melting temperature (T1 / 2) showing a softening point by the 1/2 method were measured.

[Toner particle size]
As for the particle size of the toner, the particle size distribution of the toner was measured with a precision particle size distribution measuring device (Multisizer 3 manufactured by Beckman Coulter, Inc.). The particle size distribution of the toner includes a number average particle size distribution (Dn50 / μm) indicating the particle size distribution of the toner based on the observed number of toners, and a volume average particle size distribution (Dw50 / μm) indicating the particle size distribution of the toner based on the volume. μm), Dn50 / Dw50 indicating the ratio between the number average particle size distribution and the volume average particle size distribution was measured.

[Toner gloss]
The glossiness of the toner was determined by measuring the gloss characteristics (glossiness /%) of a printed material using a clear toner with an inspection apparatus gloss meter (Murakami Color Research Laboratory GM-26D) at a measurement angle of 75 degrees.

[Toner cross-section check method]
The cross section of the toner was confirmed by observation with a transmission electron microscope “H-7100 type” (manufactured by Hitachi, Ltd.). The acceleration voltage was 100 kV. Samples were prepared by the RuO ₄ stained ultrathin section method.

[Print Evaluation Method]
When continuous printing was performed, a comprehensive judgment was made based on the presence or absence of filming at the time of printing evaluation, gloss, and appearance. The determination criteria are as follows.

“◯”: “Filming: no occurrence”, “Gloss: over 80”, “Appearance: dullness” are all satisfied.

“Δ”: “Filming: no occurrence”, “Gloss: 60 to less than 80”, “Appearance: Dull” is satisfied.

“×”: “Filming: occurs” or “Gloss: less than 60” is satisfied.

[Evaluation results]
FIG. 1 is an image diagram of a transmission electron microscope of the toner cross section of Experimental Example 1. FIG. FIG. 2 is an image diagram of a transmission electron microscope of the toner cross section of Experimental Example 2. FIG. 3 is a transmission electron microscope image diagram of the toner cross section of Comparative Example 1. FIG. 4 is an image diagram of a transmission electron microscope of the cross section of the toner of Comparative Example 3.

Table 2 below shows the evaluation results of Experimental Examples 1 and 2, and Comparative Examples 1 to 3.

  The paraffin wax (paraffin wax C) used in Comparative Example 1 has good solubility in ethyl acetate. However, as shown in Table 2, the toner produced in Comparative Example 1 had a toner volume average particle size distribution Dw50 of 4.6 μm, and a large number of small particles. Furthermore, when continuous printing was performed using the toner of Comparative Example 1, filming occurred during the evaluation, and the evaluation was stopped. Further, as shown in FIG. 3, in the cross section of the toner of Comparative Example 1, it is confirmed that the release agent (wax) is often located on the surface of the toner base particles, and there is a problem in the inclusion property of the release agent. I understand.

  In Comparative Example 2, a large number of release agents (waxes) of coarse particles of about several hundred μm were confirmed after the acid cleaning in the particle forming step. When continuous printing was performed using the toner of Comparative Example 2, the evaluation was stopped because filming occurred from the initial evaluation.

  The ester wax used in Comparative Example 3 has good solubility in ethyl acetate. Further, in the cross section of the toner of Comparative Example 4, as shown in FIG. 4, a release agent is included in the toner. However, when continuous printing was performed using the toner of Comparative Example 3, filming did not occur, but the gloss (glossiness) was 74, and a print result with a dull appearance was obtained.

  On the other hand, the paraffin wax (paraffin wax A) used in Experimental Example 1 had good solubility in ethyl acetate. Further, as shown in FIG. 1, in the toner cross section of Experimental Example 1, a release agent is included in the toner. When continuous printing was performed using the toner of Experimental Example 1, filming did not occur and the gloss (glossiness) was 87, which was higher than when the toner of Comparative Example 3 was used. It was. Good print results with a glossy appearance were obtained.

  The paraffin wax (paraffin wax B) used in Experimental Example 2 also had good solubility in ethyl acetate. Further, as shown in FIG. 2, in the toner cross section of Experimental Example 2, a release agent is included in the toner. When continuous printing was performed using the toner of Experimental Example 2, filming did not occur and the gloss (glossiness) was 82, which was higher than when the toner of Comparative Example 3 was used. It was. Good print results with a glossy appearance were obtained.

  From the comparison with the evaluation results of Comparative Example 2 above, when the solubility in ethyl acetate at 40 ° C. is smaller than 1.7 wt% and the melting point is higher than 67 ° C., coarse particles of the release agent (wax) are obtained. A lot of toner is mixed. Therefore, a part of the release agent (wax) is dissolved during printing, the release agent (wax) adheres to each member of the developing device, and the release agent (wax) of each member is cleaned. As a result, filming is likely to occur.

  Further, from the comparison with the evaluation result of Comparative Example 1 above, when the solubility in ethyl acetate at 40 ° C. is larger than 2.2 wt% and the melting point becomes lower than 62 ° C., the release agent (wax) is used as the toner. It will be located on the surface of the mother particle. Therefore, a part of the release agent (wax) is dissolved during printing, the release agent (wax) adheres to each member of the developing device, and the release agent (wax) of each member is cleaned. As a result, filming is likely to occur.

(A-3) Effect of First Embodiment From the above, paraffin wax having good solubility in ethyl acetate as a release agent for clear toner (that is, the solubility in ethyl acetate at 40 ° C. is 1.7 wt%). -2.2 wt% paraffin wax having a melting point of 62 ° C. to 67 ° C.), the toner contains the paraffin wax, does not cause filming even during printing, and has a high gloss. Can be produced.

(B) Second Embodiment Next, a second embodiment of the developer, developer manufacturing method, developer container, developing device, and image forming apparatus of the present invention will be described in detail with reference to the drawings. .

  The second embodiment also exemplifies a case where the present invention is applied to a color electrophotographic printer using a developer (toner) produced by a dissolution suspension method. The image forming apparatus of the present invention is not limited to a printer, and can be widely applied to image forming apparatuses such as copying machines and facsimile machines.

(B-1) Production of electrostatic charge developing toner of second embodiment The second embodiment is different from the first embodiment in the electrostatic charge developing toner and the production method thereof. The same developer container as that of the first embodiment can be used. Therefore, also in 2nd Embodiment, it demonstrates using FIGS.

  In the second embodiment, the clear toner and its production method will be mainly described in detail. Examples of the electrostatic charge developing toner according to the second embodiment and comparative examples are given, melting characteristics and particle size distribution of the produced toner, filming and gloss evaluation results of the produced toner, etc. Compare

  Also in the second embodiment, (a) aqueous phase preparation step, (b) oil phase adjustment step, (c) particle formation step, (d) toner base particle formation step, described in the first embodiment, (e ) According to the melt suspension method consisting of an external addition step, but in the second embodiment, in the (c) particle formation step, a surfactant as a suspension stabilizing aid is added before dropping the oil phase. To do.

  The following experimental examples and comparative examples exemplify a case where toner base particles of a clear toner are produced by employing the melt suspension method.

[Experiment 3]
(A) Water Phase Preparation Step First, as a step of obtaining an aqueous medium in which an inorganic dispersant is dispersed, 11110 parts by weight of industrial trisodium phosphate dodecahydrate is mixed with 37680 parts by weight of pure water, and the liquid temperature is 60. After dissolving at ° C., dilute nitric acid for adjusting pH is added to adjust the pH to 7.5. Furthermore, a calcium chloride aqueous solution in which 540 parts by weight of industrial calcium chloride anhydride was dissolved in 4360 parts by weight of pure water was added thereto, and the temperature was adjusted to 60 ° C. at 4300 revolutions / minute with Neomixer (manufactured by Primix Co., Ltd.). While maintaining, the mixture is stirred at high speed for 34 minutes to prepare an aqueous phase containing a dispersant.

(B) Oil phase preparation step 5300 parts by weight of ethyl acetate is heated and stirred at a liquid temperature of 50 ° C., and 56 parts by weight of alcohol-modified paraffin wax (Nippon Seiwa Co., Ltd. PARACOHOL-6150 melting point: 67 ° C.), 1 part by weight of charge control resin. Are added sequentially. In the second embodiment, paraffin wax (paraffin wax B in Table 1) is used as a release agent.

  Then, 1090 parts by weight of a polyester resin having a structure of the chemical formula (1) modified with a long-chain alkyl group to increase hydrophobicity, an acid value of 6.3 mg KOH / g, and a glass transition temperature (Tg) of 71 ° C. The oil phase is prepared by stirring until there is no solid matter.

(C) Particle Forming Step Next, the water temperature of the aqueous phase is maintained at 60 ° C., and before adding the oil phase in droplets, sodium dodecylbenzenesulfonate, which is a surfactant, is added as pure suspension to the suspension stabilization aid. An amount of 69 ppm in terms of weight (ie 2.6 parts by weight) with respect to the whole is added to the aqueous phase, the mixture is stirred at a low speed with a hand mixer and sufficiently dissolved, and then the oil phase is added. Neomixer (manufactured by Primix Co., Ltd.) ) By high-speed stirring at 1700 rpm for 10 minutes to form particles. Thereafter, ethyl acetate was removed by distillation under reduced pressure.

(D) Toner mother particle forming step After the toner in the liquid is once dehydrated, the dehydrated toner is re-dispersed in pure water, nitric acid is added to adjust the pH to 1.5 or less, and the resultant is washed with an acid to be suspended. Dissolve tricalcium phosphate, a stabilizer. Again, acid cleaning is performed using nitric acid. Further, the dehydrated toner is redispersed in pure water, stirred, and washed with water. Thereafter, the toner was dehydrated and dried to produce a toner.

(E) External Addition Step Next, as an external addition step, 100 parts by weight of the produced toner is added with 1.0 part by weight of hydrophobic silica RX50 (manufactured by Nippon Aerosil Co., Ltd., average primary particle size 40 nm), and hydrophobic silica RX200 (Japan Aerosil). A toner is obtained by adding 0.8 parts by weight of an average primary particle size of 12 nm, manufactured by the company, and stirring for 10 minutes at a rotation speed of 5400 rpm with a 10 liter Henschel mixer.

[Experimental Example 4]
In Experimental Example 4, sodium dodecylbenzenesulfonate, which is a surfactant as a suspension stabilizing aid, was added in an amount of 48 ppm in terms of weight (that is, 1.8 parts by weight) with respect to the entire pure water. Formed. The other conditions are the same as in Experimental Example 3. Further, the toner production process is the same as that in Experimental Example 3.

[Comparative Example 4]
In Comparative Example 4, sodium dodecylbenzenesulfonate, which is a surfactant as a suspension stabilizing aid, is added in an amount of 207 ppm in terms of weight (ie, 7.8 parts by weight) with respect to the entire pure water. Formed. The other conditions are the same as in Experimental Example 3. Further, the toner production process is the same as that in Experimental Example 3.

[Evaluation results]
Table 3 below shows the evaluation results of Experimental Example 3 and Experimental Example 4 and Comparative Example 4.

  When toner was produced according to Comparative Example 4, foaming started to occur when stirring with a hand mixer after adding sodium dodecylbenzenesulfonate as a surfactant, and foaming further progressed at high speed stirring at 1700 rpm. At the time of distillation, the experiment was stopped because foaming occurred to cover the entire inside of the tank.

  On the other hand, when the particle size distribution of the toner produced in Example 3 was measured, the number average particle size distribution Dn50 was 5.5 μm, the volume average particle size distribution Dw50 was 7.4 μm, and Dn50 / Dw50 was 0.74. The particle size distribution was improved as compared with Experimental Example 2, and particles of 3 μm or less on the number average particle size distribution were reduced. Further, when continuous printing evaluation was performed using the toner produced in Experiment 3, filming did not occur, and the gloss (glossiness) was measured. As a result, the gloss was 82 and the appearance was good. A glossy printing result was obtained.

  When the particle size distribution of the toner produced in Experiment Example 4 was measured, the number average particle size distribution Dn50 was 7.0 μm, the volume average particle size distribution Dw50 was 8.4 μm, and Dn50 / Dw50 was 0.83. In addition, the particle size distribution was improved, and particles of 3 μm or less on the number average particle size distribution were reduced. In addition, when continuous printing evaluation was performed using the toner produced in Experiment 4, filming did not occur, and gloss (glossiness) was measured. As a result, the gloss was 81. A glossy printing result was obtained.

(B-2) Effect of Second Embodiment From the above, paraffin wax having good solubility in ethyl acetate as a release agent for clear toner (that is, the solubility in ethyl acetate at 40 ° C. is 1.7 wt%). -2.2 wt% paraffin wax having a melting point of 62 ° C. to 67 ° C.), the paraffin wax is included in the toner, and the surfactant (suspension stabilizing aid in the aqueous phase) Sodium dodecylbenzenesulfonate) is introduced into the pure water in the aqueous phase in a concentration range of 48ppm to 69ppm in terms of weight, so that the particle size distribution becomes sharp (small particle size) and fills even during printing. It is possible to produce a clear toner with high gloss without causing ming.

  DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 11 ... Medium storage cassette, 31, 32, 33 and 34 ... Developing device, 16 ... Transfer part, 40 ... Fixing part 40, 45a-45x ... Conveyance roller, 41 and 42 ... Conveyance path switching guide, DESCRIPTION OF SYMBOLS 100 ... Development part 100,101 ... Photoconductor drum, 102 ... Charging roller, 103 ... LED head, 104 ... Developing roller, 106 ... Supply roller, 107 ... Developing blade, 105 ... Cleaning blade, 120 ... Toner cartridge, 121 ... Container A main body, 125... A toner storage unit, 122... A stirring bar, 123.

Claims (9)

In a developer obtained by dispersing and granulating an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed,
The release agent is a paraffin wax having a solubility in ethyl acetate at 40 ° C. in the range of 1.7 wt% to 2.2 wt% and a melting point in the range of 62 ° C. to 67 ° C. Developer.   In the aqueous medium, a surfactant having a concentration of 48 ppm or more and 69 ppm or less of the whole pure water in terms of weight is used, and the particle size distribution of the developer is 0.7 or more in terms of number average particle size distribution / volume average particle size distribution. The developer according to claim 1. The developer according to claim 1, wherein the binder resin is a polyester resin in which a long-chain alkyl group having a structure represented by the following chemical formula is modified.

At least a binder resin and a paraffin wax having a solubility in ethyl acetate at a range of 1.7 wt% to 2.2 wt% at 40 ° C. and a melting point of 62 ° C. to 67 ° C. as a release agent. , Prepare an oil phase component dissolved and dispersed in ethyl acetate,
Preparing a water phase by dispersing a dispersant in an aqueous medium;
A developer production method, wherein the oil phase component and the aqueous phase are mixed and dispersed and granulated to produce a developer.   In the aqueous medium, a surfactant having a concentration of 48 ppm or more and 69 ppm or less of the whole pure water in terms of weight is used, and the particle size distribution of the developer is 0.7 or more in terms of number average particle size distribution / volume average particle size distribution. The developer producing method according to claim 4, wherein: The developer production method according to claim 4, wherein the binder resin is a polyester resin in which a long-chain alkyl group having a structure represented by the following chemical formula is modified.

In a developer container that contains a developer to be supplied to an electrostatic latent image carrier that carries an electrostatic latent image,
The developer is obtained by dispersing and granulating an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed,
The release agent is a paraffin wax having a solubility in ethyl acetate at 40 ° C. in the range of 1.7 wt% to 2.2 wt% and a melting point in the range of 62 ° C. to 67 ° C. A developer container. In a developing device for forming an electrostatic latent image on an electrostatic latent image carrier using a developer supplied from a developer container,
The developer is obtained by dispersing and granulating an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed,
The release agent is a paraffin wax having a solubility in ethyl acetate at 40 ° C. in the range of 1.7 wt% to 2.2 wt% and a melting point in the range of 62 ° C. to 67 ° C. Developing device. In an image forming apparatus that performs image formation by transferring an electrostatic latent image formed on an electrostatic latent image carrier using a developer supplied from a developer container to a medium.
The developer is obtained by dispersing and granulating an oil phase component in which at least a binder resin and a release agent are dissolved and dispersed in ethyl acetate in an aqueous medium in which the dispersant is dispersed,
The release agent is a paraffin wax having a solubility in ethyl acetate at 40 ° C. in the range of 1.7 wt% to 2.2 wt% and a melting point in the range of 62 ° C. to 67 ° C. Image forming apparatus.

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