JP2014081557A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to reliably separate sheets even if thin paper passes through a glossing apparatus.SOLUTION: An image forming apparatus includes: image forming means for forming a toner image using color toner and glossing toner, on a sheet; a fixing apparatus 19 for fixing the toner image on the sheet by applying required heat and pressure to the sheet; and a glossing apparatus 20 for melting and solidifying the glossing toner, while applying the required heat and pressure again to the fixed sheet. The glossing apparatus includes: a belt member 30 stretched on heating means 36 and separation means 37, at least; pressure means 40 which is pressed toward the heating means across the belt member so as to be rotated; a first charging apparatus 43 for charging the sheet with predetermined polarity during melting/solidifying the glossing toner in the belt member; and a second charging apparatus 45 which is arranged facing the separation means and is charged with the polarity opposite the charged recording medium.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine using an electrophotographic system.

  In recent years, in addition to yellow (Y), magenta (M), cyan (C), and black (K) process color image forming color toners, color laser printers that handle special color toners such as intermediate colors have increased. . Also, printers have been used to handle special color toners for adjusting glossiness to give gloss to printed matter called transparent toner (clear toner).

  A user can create a printed matter with high added value by using these toners effectively. For example, there has been proposed a printing apparatus that performs gloss adjustment by printing (overall surface coating or partial coating) with clear toner on the entire surface or portion of a color print.

  With full-surface coating using clear toner, printing clear toner on the entire paper surface after color printing can give the entire surface of the paper a glossy feeling like a photo, and at the same time, due to image surface friction. The effects of color transfer prevention and image protection are also exhibited. When this clear toner is superimposed and normal heating and pressure fixing is performed, the glossiness of the toner image is generally measured by the specular gloss measurement method 3 (Gs (60 °)) of Japanese Industrial Standard (JIS Z 8741). The upper limit is up to 70% in the measurement by.

  In order to further increase the added value as a photographic image, a Gs (20 °) of high gloss on the surface of a silver salt photographic print is required to be 64% or more. In order to achieve this, the image surface toner layer after fixing is heated under pressure on a smooth surface belt, the image surface toner layer is adhered and re-dissolved to the belt, and a cooling device placed on the belt is used. A cooling and peeling type gloss imparting device that obtains high gloss by transferring belt surface smoothness to an image surface toner layer while cooling is known (Patent Document 1).

  It is also important to improve the productivity of photographic images by directly transferring paper from the image forming apparatus to the external glossing apparatus (in-line connection).

  In Patent Document 2, for the purpose of imparting gloss, the image once fixed is re-melted with a heating roller, brought into close contact with a belt having high smoothness, and cooled and peeled to give the image high belt smoothness. An image forming apparatus for transferring and realizing a photographic image is disclosed.

  However, in the conventional apparatus, after the gloss is applied by the gloss applicator, the paper is peeled off from the gloss applicator using the curvature (curved surface) of the separation roller and the rigidity of the paper. There was a problem that the sheet could not be peeled off well and was conveyed while jammed in close contact with the belt.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which a sheet is reliably separated even if a thin sheet is passed through a gloss applying device.

  In order to solve this problem, the present invention provides an image forming unit capable of forming a toner image using a colored toner and a gloss imparting toner on a recording medium, and applying the necessary heat and pressure to the recording medium. The image forming apparatus includes a fixing device that fixes the toner to the recording medium, and a gloss applying device that melts and solidifies the gloss-imparting toner while applying required heat and pressure again to the recording medium after fixing. A belt member wound around at least the heating unit and the separating unit, a pressing unit pressed against the heating unit with the belt member interposed therebetween, and the gloss imparting toner on the belt member. A first charging device for charging the recording medium with a required polarity during melting and solidification; and a second charging device for charging the recording medium with a polarity opposite to that of the charged recording medium. We propose an image forming apparatus according to claim.

  In the gloss applying device, an electric field is applied to the paper at the stage of transporting the paper, and the paper is charged, and an electric field having a polarity opposite to that of the paper is applied at the peeling portion, so that even a thin paper can be peeled reliably.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. It is the control block diagram which showed the production | generation process of each image data transmitted to each exposure machine. It is a schematic block diagram of the glossiness imparting apparatus which concerns on embodiment of this invention. It is a schematic block diagram of the glossiness imparting apparatus which concerns on other embodiment of this invention. It is a graph which shows the relationship between recording medium thickness and an applied voltage.

  FIG. 1 is a schematic view of a tandem electrophotographic apparatus according to the present invention. This apparatus is an example, and the present invention is not limited to the following configuration.

  1 is a main body of a tandem type color copier as an image forming apparatus, 2 is a writing unit that emits laser light based on input image information, 3 is a document conveying unit that conveys a document D to a document reading unit 4, and 4 is a document A document reading unit for reading D image information, 7 a paper feed unit for storing a recording medium P such as transfer paper, 9 a registration roller for adjusting the conveyance timing of the recording medium P, 11T, 11Y, 11M, 11C, 11K Is a photosensitive drum on which a toner image of each color (transparent, yellow, magenta, cyan, black) is formed, 12 is a charging unit that charges each of the photosensitive drums 11T, 11Y, 11M, 11C, and 11K, and 13 is each photosensitive Developing units 14 for developing electrostatic latent images formed on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K, and 14 are formed on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K. Transfer bias roller that transfers the toner image superimposed on the recording medium P, 15 denotes the photosensitive drums 11T, 11Y, 11M, 11C, cleaning unit for collecting the untransferred toner on the 11K, the.

  Reference numeral 16 denotes a transfer belt cleaning unit that cleans the transfer belt 17, reference numeral 17 denotes a transfer belt that conveys the recording medium P so that toner images and transparent toner images of a plurality of colors are superimposed on the recording medium P, and 19 1 shows an electromagnetic induction heating type fixing device that fixes a toner image (unfixed image) on a recording medium P.

The image forming apparatus 1 includes an image forming unit, a fixing device 19, and a gloss applying device 20.
The image forming unit includes a writing unit 2, a transfer belt 17, an image forming unit, an image data generating unit, a paper feeding unit 7, and a transfer bias roller 14.

  Five image forming units are provided along the transfer belt 17 at a predetermined interval at a bridge portion between the driving roller and the driven roller of the transfer belt 17.

These five image forming units have substantially the same mechanical configuration except that the developers used are different.
The developer accommodated in the developing unit is a two-component developer having a carrier and a toner, and the glass transition temperature of the transparent toner is controlled by controlling the molecular weight of the polymer constituting the toner. It is set lower than the glass transition temperature (the molecular weight of the transparent toner is smaller than the molecular weight of the colored toner).

As shown in FIG. 2, the image data generating means includes an RGB image data generating means 24, a YMCK toner image data converting means 25, and a transparent toner image data generating means 26, and each of the above-described exposure devices (writing unit 2). Each image data to be transmitted to () is generated.
The image data generation process will be described with reference to FIG. The image forming apparatus 1 according to the present embodiment includes an image reading unit such as a three-line sensor method or a mosaic method, and is configured to receive image data from a terminal such as a computer.

First, the document reading unit 4 optically reads a document, and the RGB image data generation unit 24 generates RGB image data including R image data, G image data, and B image data corresponding to the document.
The YMCK toner image data conversion means 25 obtains image data for YMCK images, that is, image data for yellow images, image data for magenta images, image data for cyan images, and image data for black images, from the above-described RGB image data. Convert to image data. The image data here is image data of a raster image.

  The YMCK toner image data conversion means 25 further converts the image data of each color of yellow, magenta, cyan, and black into halftone image data of each color. Then, the halftone image data of each color is transmitted to the corresponding exposure device. The YMCK toner image data conversion unit 25 transmits image data (raster image data) of each color of yellow, magenta, cyan, and black to the transparent toner image data generation unit 26.

  When receiving image data of each color of yellow, cyan, magenta, and black transmitted from a terminal such as a computer, the original reading unit 4 does not read the original or generate the RGB image data. The halftone dot image data of the corresponding color is transmitted to each exposure device via the toner image data conversion means 25, and the image data for each color toner image (raster image data) is converted into the transparent toner image data generation means 26. Send to.

  The transparent toner image data generation unit 26 extracts a color image area and a monochrome image area from the image data of each color of yellow, magenta, cyan, and black, and transmits transparent image data (raster image of the raster image) that is the same area as the color image area. Image data). Further, the transparent toner image data generating means 26 converts the image data into halftone dot image data and transmits it to the exposure device for transparent toner image.

  In this embodiment, as described above, an example of generating colorless and transparent image data that is the same area as the color image area from the image data of each color of yellow, magenta, cyan, and black is exemplified. Colorless and transparent image data of the same area as the color area may be generated, or colorless and transparent image data corresponding to the area specified by the user may be generated. Such technical means is not particularly limited.

  The electromagnetic induction heating type fixing device 19 includes an upper fixing roller to be heated and a lower pressure roller. The fixing device 19 passes a sheet on which an unfixed image is formed through a fixing nip where a fixing roller and a pressure roller are in contact with each other, thereby applying heat and pressure at a required fixing temperature to the sheet. The required fixing temperature is a temperature range from the maximum value of the glass transition temperature of yellow, cyan, magenta, and black color toners to the minimum value of the melting point (melting temperature) of yellow, cyan, magenta, and black color toners. Among them, the temperature is optimum for fixing in which an offset phenomenon (a phenomenon in which a part of the toner image is attached to and removed from the fixing belt) does not occur in both the colored toner layer and the transparent toner layer.

  The toner that has reached the fixing temperature is in a rubbery physical state, and when the pressure is applied to the toner in the rubbery physical state and the paper, the toner adheres to the paper and enters between the fibers of the paper. To fix on paper (anchor effect). Further, since the glass transition temperature of the transparent toner is set lower than the glass transition temperature of the colored toners of yellow, cyan, magenta, and black, the transparent toner is also fixed on the paper.

  The above-mentioned treatment temperature is not less than the glass transition temperature of the transparent toner and less than the glass transition temperature of the color toner. For example, the color toner is a pulverized toner set to a glass transition temperature of 63.6 to 65.9 ° C., When the transparent toner is a polymerized toner set to a glass transition temperature of 57.2 to 58.1 ° C., the temperature becomes 58.1 ° C. or more and less than 63.6 ° C. In addition, the hot offset occurrence temperature of the color toner and the transparent toner is preferably 160 ° C. or higher.

  Referring to FIG. 1, the gloss imparting device 20 is disposed on the downstream side of the fixing device 19 and fixes the transparent toner, which is a gloss imparting toner, on the sheet. Here, the gloss imparting device 20 is arranged close to the downstream side of the fixing device 19, but the arrangement is not essential, and may be located outside the image forming apparatus 1, for example.

FIG. 3 is a schematic configuration diagram of the gloss applying device 20 according to the embodiment of the present invention.
The gloss imparting device 20 includes a heating roller 36 as a heating means having a heater as a heat source, a separation roller 37 as a separation means for separating the recording medium P, and a gloss imparting as a belt member wound around these rollers. A first charging device disposed opposite to the belt 30, a pressure roller 40 as a pressure unit that is rotatably pressed against the heating roller 36 with the gloss imparting belt interposed therebetween, an internal cooling fan 42, and the gloss imparting belt And a separation roller 45 as a second charging device disposed opposite to the separation roller 37 with a gloss imparting belt interposed therebetween. The separation roller 45 may be in contact with the belt 30 to form a nip, or may be disposed with a minute gap therebetween.

  The gloss imparting belt 30 is made of polyimide, which is a heat-resistant resin having a thickness of 10 to 200 μm, or a metal such as nickel or SUS, and has an outer diameter of 80 to 300 mm. The surface layer may have an elastic layer made of silicon rubber with a thickness of 5 to 50 μm in order to improve adhesion to the conveyed image surface. Further, the outermost layer may have a release layer coated with a silicon-based or fluorine-based resin in order to ensure the release property at the time of separation. The belt surface, that is, the toner image side contact surface has high surface smoothness (low surface roughness).

  The heating roller 36 has an outer diameter of 30 to 90 mm and is made of Al, SUS, or Fe. In order to form a wide nip (hereinafter referred to as “gloss nip”) with the pressure roller 40, an elastic layer such as silicon rubber may be provided on the surface of the heating roller with a thickness of 0.5 to 5 mm. The heating roller 36 incorporates a heater that heats only the transparent toner placed on the recording medium P to a required processing temperature that can be transformed into a rubbery physical state. Colored toner is formed on the recording medium P, and a surface layer portion that is transparent toner is formed thereon.

The separation roller 37 has an outer diameter of φ10 to 30 mm and is made of Fe, Al, or SUS. The separation roller 45 has a similar configuration. The recording medium is separated from the gloss imparting belt 30 by the curved surface of the separation roller 37.
The pressure roller 40 has an outer diameter of φ30 to 90 mm, and an elastic layer such as fluoro rubber or silicon rubber having a thickness of 1 to 50 mm is formed on a core metal such as Fe, Al, or SUS, and the outermost layer. Is composed of a release layer made of a fluorine compound having a thickness of 5 to 50 μm.

The pressure roller 40 can operate so as to be in contact with and away from the gloss imparting belt 30 by using a cam (not shown), and the pressure roller 40 and the heating roller 36 can be changed by changing the distance between the heating roller 36 and the shaft. The gloss nip width and load formed by can be variably controlled. The pressure roller 40 is connected to a motor (not shown) and is driven to rotate, and the heating roller 36, the gloss applying belt 30, the separation roller 37, and the separation roller 45 are driven to rotate.
Since the pressure roller 40 is provided below the heating roller 36 and forms a gloss nip with the heating roller 36, the recording medium after passing through the gloss nip is conveyed with the image surface side facing upward. The internal cooling fan 42 blows downward to cool the gloss imparting belt 30 and the recording medium.

  Inside the gloss imparting belt 30, an internal cooling fan 42 as a cooling device is disposed. The cooling fan 42 cools the gloss imparting belt 30 by the air blowing, and also cools the image surface side (the surface side of the recording medium) of the recording medium P. Instead, the gloss imparting belt 30 may be cooled by providing a cooling device such as a heat sink, a heat pipe, or a Peltier element. An external cooling fan (not shown) may be provided, and the recording medium P may be rapidly cooled by applying an air flow from the fan to the back side of the recording medium P from the back side of the recording medium.

  The gloss applying device 20 has a glossy nip only at a required processing temperature at which only the surface layer portion of the transparent toner can be transformed into a rubbery physical state, and gradually toward the downstream side of the conveyance until the temperature becomes lower than the glass transition temperature of the transparent toner. The surface temperature of the gloss imparting belt 30 is lowered. In this cooling / conveying process, the recording medium is given gloss.

  The corona charger 43 is a device that charges the recording medium P with a required polarity by corona discharge. The corona charger 43 is disposed opposite to the gloss applying belt 30 on the downstream side of the gloss nip portion formed by the heating roller 36 and the pressure roller 40. Yes. The corona charger 43 is disposed downstream of the pressure roller 40, but is not limited thereto, and may be disposed upstream of the pressure roller 40. The separation roller 45 is a device that charges itself with a polarity opposite to that of the recording medium P, and is disposed to face the separation roller 37. Further, the pressure roller 40 may have a function of a separation roller as the first charging device.

  The recording medium conveyed to the gloss applying device 20 is first charged with a required polarity by corona discharge in the corona charger 43. The recording medium adheres to the gloss imparting belt 30 by the adhesive force of the transparent toner and is conveyed downstream. The separation roller 45 positioned downstream is charged with a reverse polarity by applying a reverse bias to the corona charger 43 by a power source (not shown). Therefore, the recording medium is attracted to and attached to the separation roller 45 side by electrostatic attraction. Therefore, in addition to separation on the curved surface of the separation roller 37 (curvature separation), even this thin paper can be reliably separated from the gloss imparting belt 30 by this auxiliary electrostatic attraction.

FIG. 4 is a schematic configuration diagram of a gloss applying device 20 according to another embodiment of the present invention.
Here, unlike the embodiment of FIG. 3, the pressure roller 40 is provided above the heating roller 36, and the corona charger 43 as the first charging device and the separation roller 45 as the second charging device are the separation roller 37. It is provided above. The internal cooling fan 42 blows upward to cool the gloss imparting belt 30. Also in the present embodiment, even thin paper can be reliably separated from the gloss imparting belt 30 by the auxiliary electrostatic attractive force. Further, in the gloss imparting device 20, since the recording medium is conveyed with the image side facing downward, there is no fear that the recording medium is separated from the gloss imparting belt 30 and dropped during conveyance.

FIG. 5 is a graph showing the relationship between the recording medium thickness and the applied voltage.
The force that the recording medium receives from the separation roller 45 is proportional to the charge that the recording medium P is charged by the corona charger 43 and the magnitude of the voltage applied to the separation roller 45. Accordingly, the larger the amount of charge applied to the recording medium P and the voltage applied to the separation roller 45, the larger the recording medium P receives. On the other hand, if the recording medium is thin, the contribution of the rigidity and the weight of the recording medium to the adhesive force of the transparent toner to the gloss imparting belt 30 is small, and the recording medium is difficult to be separated by the separation roller 37 having a predetermined curvature. On the contrary, if the recording medium is thick, the contribution of the rigidity and the weight of the recording medium to the adhesive force of the transparent toner to the gloss imparting belt 30 is large, and the recording medium is easily separated. Therefore, the thicker the recording medium, the smaller the amount of charge and the applied voltage may be, and the thinner the recording medium, the higher the amount of charge and the applied voltage. Therefore, in order to cancel the adsorption force of the portion where the transparent toner is present to the gloss applying belt 30, a voltage is applied to the separation roller 45 so as to be inversely proportional to the sheet thickness as shown in the figure.

Here, a voltage of 5 V is applied to a 50 g / m ² sheet, and no voltage is applied to a 100 g / m ² sheet. If it exceeds 100 g / m ² , the rigidity and weight of the recording medium will increase, so that it can be separated by the separation roller 37 having a predetermined curvature without applying a voltage. Incidentally, for example, thin paper 52~63g / ^{m 2} approximately, plain paper 63~163g / ^{m 2} approximately, thick paper has a basis weight of about 163~350g / ^{m 2,} but is not limited to this range.
Further, since the belt is charged when the sheet is charged by the charger, a neutralization mechanism is provided on the gloss imparting belt on the downstream side in the running direction (after the sheet separation) from the position where the separation roller 37 and the separation roller 45 face each other. Also good. This is because when the belt is charged, when the paper enters the glossing device, the belt is electrostatically pulled by the belt and enters in an incorrect posture, which may cause wrinkles.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport roller of the document transport unit 3 and placed on the contact glass 5 of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document D placed on the contact glass 5.

  Specifically, the document reading unit 4 scans the image of the document D on the contact glass 5 while irradiating light emitted from an illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, the image processing unit (image data generating means) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like based on the RGB color separation image signals, and transparent, yellow, magenta, cyan, black Get image information.

  The image information of each color of transparent, yellow, magenta, cyan, and black is transmitted to the writing unit 2. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 2 toward the corresponding photosensitive drums 11T, 11Y, 11M, 11C, and 11K.

  On the other hand, the five photosensitive drums 11T, 11Y, 11M, 11C, and 11K rotate in the clockwise direction of FIG. First, the surfaces of the photoconductive drums 11T, 11Y, 11M, 11C, and 11K are uniformly charged at a portion facing the charging unit 12 (a charging process). Thus, a charged potential is formed on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K. Thereafter, the surfaces of the charged photosensitive drums 11T, 11Y, 11M, 11C, and 11K reach the irradiation positions of the respective laser beams.

  In the writing unit 2, laser light corresponding to the image signal is emitted from the five light sources corresponding to each color. Each laser beam passes through a different optical path for each color component of transparent, yellow, magenta, cyan, and black (this is an exposure process).

  The laser beam corresponding to the transparent component is applied to the surface of the first photosensitive drum 11T from the left side of the drawing. At this time, the laser beam of the transparent component is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 11T by a polygon mirror that rotates at high speed. Thus, an electrostatic latent image corresponding to the transparent component is formed on the photosensitive drum 11T charged by the charging unit 12.

  Similarly, the laser beam corresponding to the yellow component is irradiated on the surface of the second photosensitive drum 11Y from the left side of the paper, and an electrostatic latent image corresponding to the yellow component is formed. The laser beam corresponding to the magenta component is irradiated onto the surface of the third photosensitive drum 11M from the left side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The cyan component laser light is applied to the surface of the fourth photosensitive drum 11C from the left side of the paper, and an electrostatic latent image of the cyan component is formed. The black component laser light is applied to the surface of the fifth photosensitive drum 11K from the left side of the paper, and an electrostatic latent image of the black component is formed.

  Thereafter, the surfaces of the photosensitive drums 11T, 11Y, 11M, 11C, and 11K on which the electrostatic latent images of the respective colors are formed reach the positions facing the developing unit 13, respectively. Then, the respective color toners are supplied from the developing units 13 onto the photosensitive drums 11T, 11Y, 11M, 11C, and 11K, and the latent images on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K are developed (see FIG. Development process.)

  Thereafter, the surfaces of the photoconductive drums 11T, 11Y, 11M, 11C, and 11K after the development process reach the facing portions of the transfer belt 17, respectively. Here, a transfer bias roller 14 is installed at each facing portion so as to contact the inner peripheral surface of the transfer belt 17. The toner images of the respective colors formed on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K are sequentially superimposed and transferred onto the recording medium P on the transfer belt 17 at the position of the transfer bias roller 14 ( It is a transfer process.)

  Then, the surfaces of the photosensitive drums 11T, 11Y, 11M, 11C, and 11K after the transfer process reach positions facing the cleaning unit 15, respectively. The untransferred toner remaining on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K is collected by the cleaning unit 15 (this is a cleaning process).

  Thereafter, the surfaces of the photoconductive drums 11T, 11Y, 11M, 11C, and 11K pass through a neutralization unit (not shown), and a series of image forming processes on the photoconductive drums 11T, 11Y, 11M, 11C, and 11K is completed.

  On the other hand, the recording medium P on which the toners of the respective colors on the photosensitive drums 11T, 11Y, 11M, 11C, and 11K are transferred (carrying) in an overlapping manner travels in the direction of the arrow in the figure and is opposed to the separation charger 18. To reach. Then, the charge accumulated in the recording medium P is neutralized at a position facing the separation charger 18, and the recording medium P is separated from the transfer belt 17 without causing toner dust or the like.

  Specifically, the recording medium P fed by the paper feeding roller 8 from the paper feeding unit 7 that stores the recording medium P passes through a conveyance guide (not shown) and is guided to the registration roller 9. The recording medium P that has reached the registration roller 9 is conveyed toward the position of the transfer belt 17 in time.

  The recording medium P to which the full color image has been transferred is separated from the transfer belt 17 and then guided to the fixing device 19. In the fixing device 19, a color image (and a transparent image) is fixed on the recording medium P at a fixing nip between the fixing roller and the pressure roller.

  The fixed recording medium P is guided to the gloss applying device 20 and passes through a gloss nip formed by the heating roller 36 and the pressure roller 40 via the gloss applying belt 30 in a fixed state. While pressure is applied to the recording medium P at the gloss nip, heat is applied from the gloss imparting belt 30, and the remelted transparent toner adheres to the gloss imparting belt 30 and is conveyed together with the recording medium in a tight contact state.

When the recording medium P enters the nip portion, the gloss imparting belt 30 is cooled by blowing air from the internal cooling fan 42, the molten transparent toner image on the recording medium P is solidified, and the surface of the fixed image portion is the belt. The surface is smoothed in accordance with the surface, and a photographic gloss is imparted (a gloss imparting step). The recording medium P that has passed through the gloss nip is first charged with a required polarity by the corona charger 43, and is further in close contact with the gloss imparting belt 30 and further conveyed. Then, downstream of the recording medium P, the separation roller 45 is charged with a polarity opposite to that of the corona charger 43. Therefore, in addition to the curvature separation by the separation roller 37, even thin paper is reliably separated from the gloss imparting belt 30 by electrostatic attraction.
The separated recording medium P is discharged as an output image outside the apparatus main body 1 by a paper discharge roller (not shown), and a series of image forming processes is completed.

Hereinafter, a method for producing a dry two-component toner containing a transparent toner will be described.
The polymerized toner described below is an example, and the present invention is not limited to this production method. In this toner, a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent is crosslinked and / or extended in an aqueous solvent. This is a toner obtained by processing.
First, constituent materials of the toner will be described.

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO), and (DIO) alone or a mixture of (DIO) and a small amount of (TO). preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diol (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenol (bisphenol A, bisphenol F) Bisphenol S); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide scan phenols (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) and a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1. The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; phenol derivatives, oximes, polyisocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acids B1 to B5 blocked (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.). Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester becomes low and the hot offset resistance deteriorates.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or elongation reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator may be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 1 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond. The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.

  The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The glass transition temperature (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If the temperature is lower than 45 ° C., the heat resistance of the toner is deteriorated.

  In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition temperature is low, as compared with known polyester-based toners.

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red, Riazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalo Cyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.
When preparing a transparent toner, it is only necessary to remove the colorant.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salt or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEGVP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face And other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, and petrolatum. And petroleum wax. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .

  The charge control agent and the release agent can be melt-kneaded together with the masterbatch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻² μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

(Toner production method)
1) A toner material liquid is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footgent F-300 (Neos), and the like.

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao Corporation), SGP (manufactured by Soken Co., Ltd.), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).

  In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole , Nitrogen-containing compounds such as ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, polyoxypro Len, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene Polyoxyethylenes such as nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

  3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group. This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is usually 0 to 150 ° C., preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

  Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 19 Fixing apparatus 20 Gloss imparting apparatus 30 Gloss imparting belt (belt)
36 Heating roller 37 Separation roller 40 Pressure roller 43 Corona charger (first charging device)
45 Separation roller (second charging device)

JP 2012-108482 A JP-A-5-158364

Claims (7)

Image forming means capable of forming a toner image using a colored toner and a gloss imparting toner on a recording medium;
A fixing device for fixing the toner image to the recording medium by applying required heat and pressure to the recording medium;
In an image forming apparatus having a gloss-imparting device that melts and solidifies the gloss-giving toner while re-applying required heat and pressure to the recording medium after fixing,
The gloss applying device includes at least a belt member wound around a heating unit and a separation unit, a pressurizing unit that is rotatably pressed toward the heating unit across the belt member, and a belt member A first charging device for charging the recording medium with a required polarity during the melting and solidifying of the gloss-imparting toner, and a second charging device for charging the recording medium with a polarity opposite to that of the charged recording medium. An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the second charging device includes a roller.   The image forming apparatus according to claim 2, wherein the first charging device includes a corona charger.   The image forming apparatus according to claim 1, wherein the pressurizing unit is provided above the heating unit, and the second charging device is provided above the separating unit.   5. The amount of charge applied to the recording medium by the first charging device and / or the magnitude of the applied voltage of the second charging device is changed according to the thickness of the recording medium. The image forming apparatus according to claim 1.   6. The amount of electric charge applied to the recording medium by the first charging device and / or an applied voltage of the second charging device is increased as the thickness of the recording medium is reduced. The image forming apparatus according to one item.   The image forming apparatus according to claim 1, wherein the belt member has a static elimination mechanism on a downstream side in a traveling direction with respect to a position where the separation unit and the second charging device are opposed to each other.

Images