Unit and image forming apparatus

Abstract

To provide a unit that forms a lustrous image having a lustrous feeling formed with a photoluminescent toner.SOLUTION: A unit comprises: a developing device that stores a developer having a photoluminescent toner including a photoluminescent pigment and develops an electrostatic charge image formed on a surface of an image holding body with the developer as a toner image; and a fixing device that has a fixing belt, a first roll and a second roll arranged inside the fixing belt and supporting the fixing belt while applying tensile force to the fixing belt, and a pressure roll sandwiching the fixing belt with the first roll to form a nip part, and has a fixing temperature of 130°C or more and 230°C or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a unit and an image forming apparatus. [Background technology]

[0002] In an image forming apparatus (such as a copier, a facsimile, or a printer) using an electrophotographic method, a toner image formed on the surface of an image carrier is transferred to the surface of a recording medium and fixed on the recording medium to form an image.

[0003] In recent years, the use of glittering toners containing glittering pigments has been investigated for the purpose of forming images having a metallic luster.

[0004] For example, Patent Document 1 discloses a "glossy toner comprising a glittering pigment, an organic pigment, a binder resin, a release agent and an external additive, in which the toluene-insoluble matter other than the glittering pigment and the external additives is 8% by mass or more and 40% by mass or less." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-062413 A Summary of the Invention [Problem to be solved by the invention]

[0006] The glittering of an image formed by a glittering toner is realized when the glittering pigment is parallelized on the surface of the recording medium when the toner image is fixed to the recording medium. However, when a glossy image is formed with a glossy toner using a fixing device (hereinafter also referred to as a "specific fixing device") that has a fixing belt, a first roll and a second roll that are arranged inside the fixing belt and support the fixing belt while applying tension to it, and a pressure roll that, together with the first roll, sandwiches the fixing belt to form a nip portion, the glossiness may be reduced.

[0007] The present invention provides a unit including a developing device containing a glossy toner and a specific fixing device, which forms a glossy image with a higher glossiness due to the glossy toner than when the fixing temperature of the fixing device is lower than 130°C. [Means for solving the problem]

[0008] Means for solving the above problems include the following aspects. <1> a developing device that contains a developer having a glittering toner containing a flat glittering pigment and develops an electrostatic image formed on a surface of an image carrier into a toner image by using the developer; a fixing device for fixing a toner image onto a surface of a recording medium, the fixing device comprising: a fixing belt; a first roll and a second roll disposed inside the fixing belt for supporting the fixing belt while applying tension to the fixing belt; and a pressure roll for sandwiching the fixing belt together with the first roll to form a nip portion, the fixing device having a fixing temperature of 130° C. or more and 230° C. or less; A unit equipped with. <2> The nip portion is flat. <1> or <2> The unit described in. <3> The fixing belt is rotated at a linear velocity of 180 mm / sec or more and 450 mm / sec or less. <1> The unit described in. <4> The difference (absolute value) in surface hardness between the first roll and the pressure roll is within 15°. <1> ~ <3> 13. A unit according to any one of claims 1 to 12. <5> The surface hardness of the first roll is 35° or more and 45° or less. <4> The unit described in. <6> The surface hardness of the pressure roll is 40° or more and 50° or less. <4> or <5> The unit described in. <7> The pressure at the nip is 2.0kgf / cm 2 More than 7.0kgf / cm 2 Is less than or equal to <4> ~ <6> 13. A unit according to any one of claims 1 to 12. <8> The pressure at the nip is 4.0kgf / cm 2 More than 7.0kgf / cm 2is less than or equal to <4> ~ <6> 13. A unit according to any one of claims 1 to 12. <9> The outer diameter ratio of the first roll to the pressure roll (first roll / pressure roll) is 0.9 or more and 1.3 or less. <4> ~ <8> 13. A unit according to any one of claims 1 to 12. <10> The glossy toner has a viscosity of 100 Pa·s or more and 1000 Pa·s or less at 130° C. <1> ~ <9> 13. A unit according to any one of claims 1 to 12. <11> The ratio (C / D) of the average maximum thickness C to the average equivalent circular diameter D of the toner particles of the glittering toner is in the range of 0.001 to 0.700. <1> ~ <10> 13. A unit according to any one of claims 1 to 12. <12> An image carrier; <1> ~ <11> a toner image forming device having the developing device among the units described in any one of claims 1 to 5 and forming a toner image on a surface of the image carrier; a transfer device that transfers the toner image formed on the surface of the image carrier onto a surface of a recording medium; A fixing device that fixes the toner image onto a surface of the recording medium, <1> ~ <11> 13. The fixing device of the unit according to claim 12, An image forming apparatus comprising: Effect of the Invention

[0009] <1> According to the invention, there is provided a unit comprising a developing device containing a glossy toner and a fixing device having a specific fixing device, which forms a glossy image with a higher glossiness due to the glossy toner compared to when the fixing temperature of the fixing device is less than 130°C. <2> According to the invention, there is provided a unit comprising a developing device containing a glossy toner and a fixing device having a specific fixing device, which forms a glossy image with a high glossiness due to the glossy toner even when the nip portion is flat, compared to when the fixing temperature of the fixing device is less than 130°C. <3> According to the present invention, a unit is provided that forms a glossy image with a glossy toner having a higher glossiness than when the fixing belt is rotated at a linear velocity of more than 450 mm / sec. <4> According to the invention, in a unit equipped with a developing device containing a glossy toner and a fixing device equipped with a specific fixing device, a unit is provided that forms a glossy image with a high glossiness due to the glossy toner, even when the difference (absolute value) in surface hardness between the first roll and the pressure roll is within 15°, compared to when the fixing temperature of the fixing device is less than 130°C. <5> According to the invention, in a unit equipped with a developing device containing a glossy toner and a fixing device equipped with a specific fixing device, a unit is provided that forms a glossy image with a high glossiness due to the glossy toner, even when the surface hardness of the first roll is 35° or more and 45° or less, compared to when the fixing temperature of the fixing device is less than 130°C. <6> According to the invention, in a unit equipped with a developing device containing a glossy toner and a fixing device equipped with a specific fixing device, a unit is provided that forms a glossy image with a high glossiness due to the glossy toner, even when the surface hardness of the pressure roll is 40° or more and 50° or less, compared to when the fixing temperature of the fixing device is less than 130°C. <7> or <8> According to the invention, in a unit including a developing device containing a glitter toner and a fixing device having a specific fixing device, the pressure in the nip portion is 2.0 kgf / cm 2 or more lower than when the fixing temperature of the fixing device is less than 130° C. 2 More than 7.0kgf / cm 2 Less than or equal to 4.0kgf / cm 2 More than 7.0kgf / cm 2 Even if the amount is less than this, a unit that forms a highly glossy image using glossy toner can be provided. <9> According to the invention, in a unit equipped with a developing device containing a glossy toner and a fixing device equipped with a specific fixing device, a unit is provided that forms a glossy image with a high glossiness due to the glossy toner, even when the outer diameter ratio of the first roll to the pressure roll (first roll / pressure roll) is 0.9 or more and 1.3 or less, compared to when the fixing temperature of the fixing device is less than 130°C. <10> According to the present invention, a unit is provided that forms a glossy image with a higher glossiness due to the glossy toner, compared to when the viscosity of the glossy toner at 130° C. is 100 Pa·s or more and exceeds 1000 Pa·s. <11> According to the invention, in a unit equipped with a developing device containing a glossy toner and a fixing device equipped with a specific fixing device, a unit is provided that forms a glossy image with a high glossiness due to the glossy toner, even when the ratio (C / D) of the average maximum thickness C to the average equivalent circular diameter D of the toner particles possessed by the glossy toner is in the range of 0.001 or more and 0.700 or less, compared to when the fixing temperature of the fixing device is less than 130°C. <12> According to the invention, there is provided a unit comprising a developing device containing a glossy toner and a fixing device having a specific fixing device, which forms a glossy image with a higher glossiness due to the glossy toner compared to a unit in which the fixing temperature of the fixing device is less than 130°C. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view illustrating an example of a glittering toner. [Diagram 3] 2 is a schematic configuration diagram illustrating an example of a unit and a fixing device of an image forming apparatus according to the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the present embodiment, which is an example of the present invention, will be described. These descriptions and examples are merely illustrative of the embodiment, and do not limit the scope of the present invention.

[0012] In the numerical ranges described in the present embodiment, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in the present embodiment. In addition, in the numerical ranges described in the present embodiment, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In this embodiment, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. When the embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the size of the members in each drawing is conceptual, and the relative relationship between the sizes of the members is not limited to this. In this embodiment, each component may contain multiple types of corresponding substances. When referring to the amount of each component in the composition in this embodiment, if multiple substances corresponding to each component are present in the composition, the amount refers to the total amount of the multiple substances present in the composition, unless otherwise specified.

[0013] [unit] The unit according to this embodiment includes a developing device that contains a developer having a photochromic toner that includes a flat photochromic pigment and develops an electrostatic charge image formed on the surface of an image carrier into a toner image using the developer, and a fixing device that fixes the toner image onto the surface of a recording medium, the fixing device having a fixing temperature of 130°C or higher and 230°C or lower. The fixing device (specific fixing device) used in the present invention includes a fixing belt, a first roll and a second roll that are disposed inside the fixing belt and support the fixing belt while applying tension to the fixing belt, and a pressure roll that, together with the first roll, sandwiches the fixing belt to form a nip portion.

[0014] The unit according to the present embodiment, with the above-mentioned configuration, forms a highly glossy image with glossy toner for the following reasons.

[0015] The glittering of an image produced by a glittering toner is realized when the glittering pigment is parallelized to the surface of the recording medium when the toner image is fixed to the recording medium. In other words, the glittering of an image produced by a glittering toner is realized when the glittering pigment is oriented so that the surface facing the thickness direction of the glittering pigment is aligned with the surface of the recording medium when fixed.

[0016] However, when a glossy image is formed using a glossy toner by using a specific fixing device, the glossiness may be reduced.

[0017] Therefore, in the unit according to the present embodiment, the fixing temperature of the specific fixing device is set to 130° C. or higher and 230° C. or lower (preferably 150° C. or higher and 210° C. or lower). This allows the toner image made of the glittering toner to be sufficiently melted in the nip portion, making it easier for the glittering pigment to be parallelized to the surface of the recording medium. This allows the glittering toner to form a glittering image with a high glittering feel.

[0018] Here, the fixing temperature refers to the temperature of the nip portion.

[0019] In addition, in the unit according to the present embodiment, it is preferable that the fixing belt is rotated at a linear speed of 180 mm / sec to 450 mm / sec (preferably 200 mm / sec to 430 mm / sec). By setting the fixing temperature to 130°C to 230°C and reducing the linear speed of the fixing belt within the above range, sufficient heat is applied to the toner image formed by the glitter toner. This makes it possible to form a glitter image with a high glittering feeling by the glitter toner.

[0020] In particular, when the nip portion of the specific fixing device is flat, the glittering pigment is less likely to be parallel to the surface of the recording medium during fixing, and the glittering effect is likely to be reduced. If the nip portion (i.e., the contact surface between the fixing belt and the pressure roll) is curved along the shape of either the opposing first roll or the pressure roll, a large shear force is applied to the glittering toner at the nip portion (especially at the nip portion exit where the curvature of the curve changes significantly), and the glittering pigment is likely to become parallel to the surface of the recording medium during fixing. On the other hand, if the nip portion is flat, the glittering toner is less likely to be subjected to shear force. Therefore, if the nip portion is flat, the glittering feeling is likely to be reduced. However, even in a specific fixing device with a flat nip portion, by setting the fixing temperature to 130° C. or higher and 230° C. or lower, it is possible to form a highly glossy image using glossy toner.

[0021] Here, "the nip portion is flat" means that the opposing first roll and pressure roll are arranged so that they are crushed against each other without biting into each other, and the contact surface between the fixing belt and the pressure roll is not curved along the shape of either the first roll or the pressure roll before they are arranged.

[0022] [Image forming equipment] An image forming apparatus including a unit according to this embodiment will be described below.

[0023] The image forming apparatus according to the present embodiment includes an image carrier and a developing device among the units according to the present embodiment, and includes a toner image forming device that forms a toner image on the surface of the image carrier, a transfer device that transfers the toner image formed on the surface of the image carrier to a surface of a recording medium, and a fixing device that fixes the toner image on the surface of the recording medium, the fixing device being among the units according to the present embodiment.

[0024] An example of a toner image forming device is a device including an image carrier, a charging device that charges the surface of the image carrier, an electrostatic image forming device that forms an electrostatic image on the charged surface of the image carrier, and a developing device that develops the electrostatic image formed on the surface of the image carrier using a developer containing a photoluminescent toner to form a toner image.

[0025] The image forming apparatus according to the present embodiment may be any of known image forming apparatuses, such as a direct transfer type apparatus that transfers a toner image formed on the surface of an image holder directly to a recording medium; an intermediate transfer type apparatus that performs primary transfer of a toner image formed on the surface of an image holder to the surface of an intermediate transfer body, and then performs secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; an apparatus equipped with a cleaning device that cleans the surface of the image holder before charging after the toner image is transferred; an apparatus equipped with a static elimination device that irradiates the surface of the image holder with static elimination light to eliminate static electricity before charging after the toner image is transferred; and an apparatus equipped with an image holder heating member for increasing the temperature of the image holder and reducing the relative temperature. In the case of an intermediate transfer type device, the transfer device is configured to have, for example, an intermediate transfer body onto whose surface a toner image is transferred, a primary transfer device which primarily transfers the toner image formed on the surface of the image carrier onto the surface of the intermediate transfer body, and a secondary transfer device which secondarily transfers the toner image transferred onto the surface of the intermediate transfer body onto the surface of a recording medium.

[0026] An example of an image forming apparatus according to the present embodiment will be described below, but the present invention is not limited to this. In the following description, the main parts shown in the drawings will be described, and the description of the rest will be omitted. In the following description, the glitter toner will be referred to as "silver toner."

[0027] FIG. 1 is a schematic diagram showing an example of an image forming apparatus according to the present embodiment, and shows a five-unit tandem type and intermediate transfer type image forming apparatus. Figure 1 The image forming apparatus shown in FIG. 1 includes first to fifth electrophotographic image forming units 150Y, 150M, 150C, 150K, and 150B (an example of a toner image forming apparatus) that output images of each color, yellow (Y), magenta (M), cyan (C), black (K), and silver (B), based on color-separated image data. These image forming units 150Y, 150M, 150C, 150K, and 150B are arranged in parallel at a predetermined distance from each other in the horizontal direction. These image forming units 150Y, 150M, 150C, 150K, and 150B may be process cartridges that are detachably attached to the image forming apparatus.

[0028] An intermediate transfer belt 133 is provided below each of the image forming units 150Y, 150M, 150C, 150K, and 150B, and extends through each unit. The intermediate transfer belt 133 is provided by being wound around a driving roll 113, a support roll 112, and an opposing roll 114, which are in contact with the inner surface of the intermediate transfer belt 133, and runs in a direction from the first image forming unit 150Y to the fifth image forming unit 150B (in the direction of the arrow B in FIG. 1). An intermediate transfer belt cleaning device 116 is provided on the image carrying surface side of the intermediate transfer belt 133, facing the driving roll 113. In addition, a voltage application device 160 is provided on the upstream side of the intermediate transfer belt cleaning device 116 in the rotation direction of the intermediate transfer belt 133, which generates an electric field between the intermediate transfer belt 133 and the support roll 113 by generating a potential difference between the intermediate transfer belt 133 and the intermediate transfer belt cleaning device 116. The developing devices (examples of developing devices) 120Y, 120M, 120C, 120K, and 120B of each image forming unit 150Y, 150M, 150C, 150K, and 150B are supplied with yellow, magenta, cyan, black, and silver toner contained in toner cartridges 140Y, 140M, 140C, 140K, and 140B, respectively.

[0029] Since the first to fifth image forming units 150Y, 150M, 150C, 150K, and 150B have the same configuration, operation, and function, the first image forming unit 150Y that forms a yellow image and is arranged upstream in the direction in which the intermediate transfer belt travels will be described here as a representative example.

[0030] The first image forming unit 150Y has a photoconductor 111Y that acts as an image carrier. Around the photoconductor 111Y, a charging roll (an example of a charging device) 118Y that charges the surface of the photoconductor 111Y to a predetermined potential, an exposure device (an example of an electrostatic image forming device) 119Y that exposes the charged surface to a laser beam based on a color-separated image signal to form an electrostatic image, a developing device (an example of a developing device) 120Y that supplies toner to the electrostatic image to develop it, a primary transfer roll (an example of a primary transfer device) 117Y that transfers the developed toner image onto the intermediate transfer belt 133, and a photoconductor cleaning device (an example of a cleaning device) 115Y that removes toner remaining on the surface of the photoconductor 111Y after the primary transfer are arranged in this order. The primary transfer roll 117Y is disposed inside the intermediate transfer belt 133, and is provided at a position facing the photoconductor 111Y. A bias power supply (not shown) that applies a primary transfer bias is connected to the primary transfer rolls 117Y, 117M, 117C, 117K, and 117B of each image forming unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

[0031] Hereinafter, the operation of forming a yellow image in first image forming unit 150Y will be described. First, prior to operation, the surface of the photoconductor 111Y is charged to a potential of −600V to −800V by the charging roll 118Y. The photoconductor 111Y has a conductivity (for example, a volume resistivity of 1×10 at 20° C. -6The photosensitive layer is formed by laminating a photosensitive layer on a substrate having a resistivity of Ωcm or less. This photosensitive layer is usually highly resistive (the resistance of ordinary resins), but when irradiated with a laser beam, the resistivity of the portion irradiated with the laser beam changes. Therefore, a laser beam is irradiated from an exposure device 119Y onto the charged surface of the photosensitive member 111Y in accordance with image data for yellow sent from a control unit (not shown). As a result, an electrostatic charge image of a yellow image pattern is formed on the surface of the photosensitive member 111Y.

[0032] An electrostatic image is an image formed on the surface of the photoconductor 111Y by electrostatic charging. The laser beam from the exposure device 119Y reduces the resistivity of the irradiated parts of the photosensitive layer, causing the charged charges on the surface of the photoconductor 111Y to flow, while the charges remain in the parts not irradiated by the laser beam. This is a so-called negative latent image. The electrostatic image formed on the photoconductor 111Y rotates to a predetermined developing position as the photoconductor 111Y travels. At this developing position, the electrostatic image on the photoconductor 111Y is developed into a toner image by the developing device 120Y and made visible.

[0033] The developing device 120Y contains a developer including at least yellow toner and a carrier, for example. The yellow toner is triboelectrically charged by being stirred inside the developing device 120Y, and is held on a developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the charge on the photoconductor 111Y. As the surface of the photoconductor 111Y passes through the developing device 120Y, the yellow toner electrostatically adheres to the discharged latent image portion on the surface of the photoconductor 111Y, and the latent image is developed with the yellow toner. The photoconductor 111Y on which the yellow toner image has been formed continues to travel at a predetermined speed, and the toner image developed on the photoconductor 111Y is transported to a predetermined primary transfer position.

[0034] When the yellow toner image on the photoconductor 111Y is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 117Y, and an electrostatic force from the photoconductor 111Y toward the primary transfer roll 117Y acts on the toner image, and the toner image on the photoconductor 111Y is transferred onto the intermediate transfer belt 133. The transfer bias applied at this time has a polarity (+) opposite to the polarity (-) of the toner, and is controlled to, for example, +10 μA by a control unit (not shown) in the first image forming unit 150Y. On the other hand, the toner remaining on the photoconductor 111Y is removed and collected by the photoconductor cleaning device 115Y.

[0035] The primary transfer bias applied to the primary transfer rolls 117M, 117C, 117K, and 117B subsequent to the second image forming unit 150M is also controlled in accordance with the first image forming unit 150Y. In this manner, the intermediate transfer belt 133 onto which the yellow toner image has been transferred by the first image forming unit 150Y is transported successively through the second to fifth image forming units 150M, 150C, 150K, and 150B, where the toner images of each color are superimposed and multi-transferred.

[0036] The intermediate transfer belt 133 onto which the five color toner images are transferred in multiple layers through the first to fifth image forming units reaches a secondary transfer section that is composed of the intermediate transfer belt 133, the opposing roll 114 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer device) 134 arranged on the image carrying surface side of the intermediate transfer belt 133. Meanwhile, a recording paper (an example of a recording medium) P is fed at a predetermined timing into the gap between the secondary transfer roll 134 and the intermediate transfer belt 133 via a supply mechanism, and a secondary transfer bias is applied to the opposing roll 114. The transfer bias applied at this time has a (-) polarity that is the same as the (-) polarity of the toner, and an electrostatic force from the intermediate transfer belt 133 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 133 is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection device (not shown) that detects the resistance of the secondary transfer section, and is voltage controlled.

[0037] Thereafter, the recording paper P is sent to a pressure contact portion (nip portion) of a pair of fixing rolls in a fixing device (one example of a fixing device) 135, where the toner image is fixed onto the recording paper P, forming a fixed image.

[0038] The recording paper P onto which the toner image is transferred can be, for example, plain paper used in electrophotographic copying machines, printers, etc. In addition to the recording paper P, other examples of the recording medium include overhead projector sheets and the like. To further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper in which the surface of ordinary paper is coated with a resin or the like, art paper for printing, etc. are preferably used.

[0039] After the color image has been fixed, the recording paper P is conveyed toward the discharge section, and the series of color image forming operations is completed.

[0040] Here, the developing device 120B of the image forming unit 150B corresponds to an example of the developing device in the unit according to the present embodiment. The fixing device 135 corresponds to an example of the transfer device in the unit according to the present embodiment. The device including the developing device 120B and the fixing device 135 corresponds to an example of the unit according to the above-mentioned embodiment.

[0041] 1 is an image forming apparatus having a configuration in which toner cartridges 140Y, 140M, 140C, 140K, and 140B are detachably attached, and developing devices 120Y, 120M, 120C, 120K, and 120B are connected to toner cartridges corresponding to the respective developing devices (colors) by toner supply pipes (not shown). When the toner contained in a toner cartridge becomes low, the toner cartridge is replaced.

[0042] [Developing device] The unit and the developing device of the image forming apparatus according to the present embodiment will be described in more detail below. Note that the reference numerals will be omitted in the description. The developing device is provided, for example, downstream in the rotation direction of the image carrier from the position where light is irradiated by the electrostatic image forming device. A container for containing a developer is provided within the developing device. The container contains a developer having a glittering toner containing a glittering pigment. The glittering toner is contained, for example, in a charged state within the developing device. Details of the glittering toner will be described later.

[0043] The developing device 18 includes a developing member that develops the electrostatic image formed on the surface of the image carrier with a developer containing, for example, glitter toner, and a power source that applies a developing voltage to the developing member. The developing member is, for example, electrically connected to the power source.

[0044] The developing member of the developing device is selected depending on the type of developer, and may be, for example, a developing roll having a developing sleeve with a built-in magnet.

[0045] In the developing device (including a power source), for example, a developing voltage is applied to the developing member. The developing member to which the developing voltage is applied is charged to a developing potential corresponding to the developing voltage. Then, the developing member charged to the developing potential holds, for example, the developer contained in the developing device on its surface, and supplies the glitter toner contained in the developer from inside the developing device to the surface of the image carrier.

[0046] The toner supplied onto the image carrier adheres to the electrostatic image on the image carrier by electrostatic force, for example. In detail, the photochromic toner contained in the developer is supplied to the area of ​​the image carrier where the electrostatic image is formed by the potential difference in the area where the image carrier faces the developing member, that is, the potential difference between the potential of the surface of the image carrier in the area and the development potential of the developing member. If the developer contains a carrier, the carrier is returned to the developing device while being held by the developing member.

[0047] For example, an electrostatic image on the image carrier is developed with a photoluminescent toner supplied from a developing member, and a toner image corresponding to the electrostatic image is formed on the image carrier.

[0048] [Brilliant toner] The glittering toner will now be described. The glitter toner contains flat glitter pigment. Specifically, the glitter toner has glitter toner particles containing a glitter pigment. The glitter toner may also contain an external additive.

[0049] (Photoluminescent Toner Particles) The glittering toner particles contain, for example, a binder resin and a glittering pigment. The glittering toner particles may contain a colorant, a release agent, and other components other than the glittering pigment.

[0050] -Binding resin- Examples of the binder resin include vinyl resins made of homopolymers of monomers such as styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), and olefins (e.g., ethylene, propylene, butadiene, etc.), or copolymers of two or more of these monomers. Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin, mixtures of these with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the coexistence of these. These binder resins may be used alone or in combination of two or more kinds.

[0051] In particular, it is preferable to use a combination of an amorphous resin and a crystalline resin as the binder resin. However, the mass ratio of the amorphous resin to the crystalline resin (crystalline resin / amorphous resin) is preferably from 3 / 97 to 50 / 50, and more preferably from 7 / 93 to 30 / 70.

[0052] Here, the term "amorphous resin" refers to a resin that, in a thermal analysis measurement using differential scanning calorimetry (DSC), has only a stepwise endothermic change rather than a clear endothermic peak, is a solid at room temperature, and is thermoplasticized at a temperature equal to or higher than the glass transition temperature. On the other hand, a crystalline resin refers to a resin that has a clear endothermic peak rather than a stepwise change in endothermic amount in differential scanning calorimetry (DSC). Specifically, for example, a crystalline resin means a resin whose half-width of an endothermic peak is within 10°C when measured at a heating rate of 10°C / min, and an amorphous resin means a resin whose half-width exceeds 10°C or a resin in which no clear endothermic peak is observed.

[0053] The amorphous resin will now be described. Examples of the amorphous resin include known amorphous resins such as amorphous polyester resin, amorphous vinyl resin (e.g., styrene-acrylic resin, etc.), epoxy resin, polycarbonate resin, polyurethane resin, etc. Among these, amorphous polyester resin and amorphous vinyl resin (particularly styrene-acrylic resin) are preferred, and amorphous polyester resin is more preferred. In addition, it is also a preferred embodiment to use an amorphous polyester resin and a styrene-acrylic resin in combination as the amorphous resin. It is also a preferred embodiment to use an amorphous resin having an amorphous polyester resin segment and a styrene-acrylic resin segment as the amorphous resin.

[0054] Examples of the crystalline resin include known crystalline resins such as crystalline polyester resins and crystalline vinyl resins (e.g., polyalkylene resins, long-chain alkyl (meth)acrylate resins, etc.) Among these, crystalline polyester resins are preferred from the viewpoints of the mechanical strength and low-temperature fixability of the glittering toner.

[0055] The content of the binder resin is preferably from 40% by mass to 95% by mass, more preferably from 50% by mass to 90% by mass, and even more preferably from 60% by mass to 85% by mass, based on the total amount of the glittering toner particles.

[0056] -Photoluminescent pigments- Examples of the luster pigment include pigments that can impart a sense of luster such as metallic luster.Specific examples of the luster pigment include metal powders such as aluminum (metal of aluminum alone), brass, bronze, nickel, stainless steel, and zinc; mica coated with titanium oxide, yellow iron oxide, and the like; flaky inorganic crystal substrates coated with barium sulfate, layered silicate, layered aluminum silicate, and the like; single crystal plate-like titanium oxide; basic carbonate; bismuth acid oxychloride; natural guanine; flaky glass powder; and flaky glass powder with metal deposition, and there is no particular limit to the luster pigments. Among these, metal powders are preferred as the bright pigment, particularly from the viewpoint of specular reflection intensity, and among these, aluminum is most preferred.

[0057] The average length in the major axis direction of the bright pigment is preferably from 1 μm to 30 μm, more preferably from 3 μm to 20 μm, and even more preferably from 5 μm to 15 μm. The ratio (aspect ratio) of the average length in the major axis direction to the average length in the thickness direction of the shiny pigment is preferably 5 or more and 200 or less, more preferably 10 or more and 100 or less, and even more preferably 30 or more and 70 or less.

[0058] The average length and aspect ratio of each of the bright pigments are measured by the following method: A scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) is used to take a photograph of the bright pigment at a measurable magnification (300 to 100,000 times), and with the resulting image of the bright pigment two-dimensionalized, the length in the major axis direction and the length in the thickness direction of each particle are measured, and the average length in the major axis direction and the aspect ratio of the bright pigment are calculated. Here, the length in the major axis direction of the bright pigment refers to the longest part when the bright pigment is observed in the thickness direction of the bright pigment, and the length in the thickness direction of the bright pigment refers to the longest part when the bright pigment is observed in a direction perpendicular to the thickness direction of the bright pigment.

[0059] The volume average particle size of the bright pigment is preferably from 1.0 μm to 20.0 μm, and more preferably from 2.0 μm to 15.0 μm.

[0060] The volume average particle size of the bright pigment is measured as follows. Based on the particle size distribution measured with a measuring device such as Multisizer II (manufactured by Coulter), a cumulative distribution is drawn for each volume of divided particle size ranges (channels) from the smallest diameter side, and the particle size at which the cumulative 50% is reached is the volume average particle size. The volume average particle size of the glittering pigment in the glittering toner particles after production is measured by mixing and stirring the glittering toner with a solvent that is capable of dissolving only the resin but not the glittering pigment, and after the resin has sufficiently dissolved in the solvent, the glittering pigment is subjected to solid-liquid separation and the volume average particle size is measured using a particle size distribution measuring device similar to that described above.

[0061] The content of the glittering pigment is preferably from 1% by mass to 70% by mass, more preferably from 5% by mass to 50% by mass, and even more preferably from 5% by mass to 40% by mass, based on the total mass of the glittering toner particles.

[0062] -Colorants other than photoluminescent pigments- Examples of colorants other than brilliant pigments include carbon black, chrome yellow, Hansa Yellow, benzidine yellow, threne yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, Balkan orange, watch young red, permanent red, brilliant carmine 3B, brilliant carmine 6B, DuPont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, and aniline. Examples of pigments include blue, ultramarine blue, chalcoil blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, and malachite green oxalate; and dyes such as acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole. The colorants other than the luster pigment may be used alone or in combination of two or more kinds.

[0063] The colorant other than the luster pigment may be a colorant that has been surface-treated as necessary, or may be used in combination with a dispersant. In addition, a plurality of colorants may be used in combination.

[0064] The content of colorants other than the glittering pigment is adjusted according to the color tone of the glittering toner.

[0065] -Release agent- Examples of the release agent include hydrocarbon waxes, natural waxes such as carnauba wax, rice wax, and candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, and ester waxes such as fatty acid esters and montan acid esters. The release agent is not limited to these.

[0066] The melting temperature of the release agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower. The melting temperature of the release agent is determined from a DSC curve obtained by differential scanning calorimetry (DSC) based on the "melting peak temperature" described in the method for determining melting temperature in JIS K7121:1987 "Method for measuring transition temperature of plastics."

[0067] The content of the release agent is preferably from 1% by mass to 20% by mass, and more preferably from 5% by mass to 15% by mass, based on the total amount of the glittering toner particles.

[0068] -Other additives- Examples of other additives include known additives such as magnetic materials, charge control agents, inorganic powders, etc. These additives are contained in the glittering toner particles as internal additives.

[0069] -Characteristics of photoluminescent toner particles- The glittering toner particles are flat and have an average equivalent circle diameter D longer than their average maximum thickness C. If the glittering toner particles are flat with a circular equivalent diameter longer than their thickness (see Figure 2), then in the fixing step of image formation, the glittering toner particles are thought to line up so that their flat surfaces face the recording medium surface due to the pressure applied during fixing. In Figure 2, 2 indicates the glittering toner particles, 4 indicates the glittering pigment, and L indicates the thickness of the glittering toner particles.

[0070] The ratio (C / D) of the average maximum thickness C to the average equivalent circular diameter D is preferably in the range of 0.001 or more and 0.700 or less, more preferably in the range of 0.001 or more and 0.500 or less, even more preferably in the range of 0.100 or more and 0.600 or less, and particularly preferably in the range of 0.300 or more and 0.450 or less. By making the ratio (C / D) 0.001 or more, the strength of the toner particles is ensured, breakage due to stress during image formation is suppressed, and a decrease in charge due to exposure of the glitter pigment and the resulting fogging are suppressed. On the other hand, by making the ratio (C / D) 0.700 or less, excellent glitter is obtained.

[0071] The average maximum thickness C and the average equivalent circle diameter D are measured by the following method. The glittering toner particles are placed on a smooth surface and dispersed evenly by applying vibration. For 1,000 toner particles, the maximum thickness C of the toner particles and the equivalent circle diameter D of the surface as viewed from above are measured at 1,000 times magnification using a color laser microscope "VK-9700" (manufactured by Keyence Corporation), and the arithmetic average value is calculated.

[0072] When a cross section of a glittering toner particle in the thickness direction is observed, the proportion (by number) of glittering pigments in which the angle between the long axis direction of the toner particle in the cross section and the long axis direction of the glittering pigment is in the range of -30° to +30° is preferably 60% or more of all glittering pigments observed.Moreover, this proportion is more preferably 70% or more and 95% or less, and particularly preferably 80% or more and 90% or less. When the above ratio is 60% or more, excellent brilliance can be obtained.

[0073] Here, a method for observing the cross section of the glittering toner particles will be described. The toner particles are embedded in a bisphenol A liquid epoxy resin and a curing agent, and then a cutting sample is prepared. The cutting sample is then cut at -100°C using a cutting machine with a diamond knife, such as an ultramicrotome (UltracutUCT, manufactured by Leica), to prepare a sample for observation. The observation sample is observed, for example, with an ultra-high resolution field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) at a magnification where 1 to 10 photoluminescent pigment toner particles can be seen in one field of view. Specifically, the cross section of a glossy toner particle (cross section along the thickness direction of the glossy toner particle) is observed, and for 100 observed glossy toner particles, the number of glossy pigments for which the angle between the long axis direction in the cross section of the glossy toner particle and the long axis direction of the glossy pigment is in the range of -30° to +30° is counted using image analysis software such as image analysis software (Win ROOF) manufactured by Mitani Shoji Co., Ltd., or an output sample of the observed image and a protractor, and the percentage is calculated.

[0074] The volume average particle size of the glittering toner particles is preferably 3 μm or more and 30 μm or less, and more preferably 5 μm or more and 20 μm or less.

[0075] The various average particle sizes and particle size distribution indexes of the glittering toner particles are measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and the electrolyte is measured using an ISOTON-II (manufactured by Beckman Coulter, Inc.). For the measurement, 0.5 mg to 50 mg of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this is then added to 100 ml to 150 ml of the electrolyte. The electrolyte with the sample suspended in it is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with diameters in the range of 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 50,000. Based on the measured particle size distribution, cumulative distributions of volume and number are drawn for each divided particle size range (channel) from the smallest diameter side, and the particle size at 16% of the cumulative size is defined as the volume particle size D16v, the number particle size D16p, the particle size at 50% of the cumulative size as the volume average particle size D50v, the cumulative number average particle size D50p, and the particle size at 84% of the cumulative size as the volume particle size D84v and number particle size D84p. Using these, the volumetric particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 The number size distribution index (GSDp) is (D84p / D16p) 1 / 2 It is calculated as:

[0076] The ratio (aspect ratio) of the average length in the major axis direction to the average length in the thickness direction of the glittering toner particles is preferably 1.5 or more and 15 or less, more preferably 2 or more and 10 or less, and even more preferably 3 or more and 8 or less. The average length in the thickness direction and the average length in the major axis direction of the glittering toner particles are calculated by placing the glittering toner particles on a smooth surface and dispersing them evenly by applying vibration. For 1,000 glittering toner particles, the maximum thickness and the major axis length of the surface as viewed from above are measured using a color laser microscope "VK-9700" (manufactured by Keyence Corporation) at 1,000 times magnification, and then calculating the arithmetic average value.

[0077] (External additives) Examples of the external additive include inorganic particles, such as SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, K2O·(TiO2)n, Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, and MgSO4.

[0078] The surface of the inorganic particles as an external additive may be subjected to a hydrophobic treatment. The hydrophobic treatment may be performed, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

[0079] Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and fluorine-based polymer particles).

[0080] The amount of the external additive added is, for example, preferably from 0.01% by mass to 5% by mass, and more preferably from 0.01% by mass to 2.0% by mass, based on the toner particles.

[0081] (Characteristics of photoluminescent toner) The glitter toner is sufficiently melted in the nip portion of the fixing device, so that a glitter image having a high glittering feeling can be formed by the glitter toner. Therefore, the viscosity of the glitter toner at 130° C. is preferably 100 Pa·s or more and 1000 Pa·s or less, and more preferably 150 Pa·s or more and 800 Pa·s or less. The viscosity of the glitter toner can be adjusted by the type and molecular weight of the binder resin.

[0082] Here, the viscosity of the glittering toner is measured at 130° C. using an "ARES (apparatus name)" (manufactured by Rheometrics Corporation).

[0083] The "brilliance" of a glossy image produced by a glossy toner refers to the fact that the image has a shine like metallic luster when viewed. Specifically, the glitter toner is used for a solid image (for example, when the amount of glitter toner is 3.5 g / m 2 When the above-mentioned image is formed, it is preferable that the ratio (X / Y) of the reflectance X at a light-receiving angle of +30° to the reflectance Y at a light-receiving angle of -30°, which is measured when the image is irradiated with incident light at an incident angle of -45° using a goniophotometer, is 2 or more and 100 or less.

[0084] A ratio (X / Y) of 2 or more indicates that the light is reflected more to the side opposite the incident side (positive angle side) than to the side where the light is incident (negative angle side), meaning that diffuse reflection of the incident light is suppressed. When diffuse reflection occurs, where incident light is reflected in various directions, the color appears dull when the reflected light is visually inspected. Therefore, when the ratio (X / Y) is less than 2, the gloss cannot be confirmed even when the reflected light is visually inspected, and the brilliance may be poor. On the other hand, if the ratio (X / Y) exceeds 100, the viewing angle at which the reflected light can be seen becomes too narrow, and the regular reflected light component is large, so that the toner may appear black depending on the viewing angle. Also, it is difficult to manufacture a toner with a ratio (X / Y) exceeding 100.

[0085] The ratio (X / Y) is more preferably 4 or more and 50 or less, further preferably 6 or more and 20 or less, and particularly preferably 8 or more and 15 or less.

[0086] -Measurement of the ratio (X / Y) using a goniophotometer- First, the angle of incidence and the angle of reception will be described. In this embodiment, when measuring with a goniophotometer, the angle of incidence is set to -45°. This is because the measurement sensitivity is high for images with a wide range of glossiness. The reason why the light-receiving angles are set to -30° and +30° is that these have the highest measurement sensitivity for evaluating images with a glittery feel and images without a glittery feel.

[0087] Next, the method for measuring the ratio (X / Y) will be described. The image to be measured (glossy image) is irradiated with light at an incident angle of -45° using a GC5000L spectrophotometer manufactured by Nippon Denshoku Industries Co., Ltd., and the reflectance X at an acceptance angle of +30° and the reflectance Y at an acceptance angle of -30° are measured. The reflectance X and reflectance Y are measured at 20 nm intervals for light with wavelengths ranging from 400 nm to 700 nm, and the average reflectance at each wavelength is used. The ratio (X / Y) is calculated from these measurement results.

[0088] From the viewpoint of satisfying the ratio (X / Y), it is preferable that the glittering toner satisfies the following requirements (1) and (2). (1) The average equivalent circle diameter D is longer than the average maximum thickness C of the glittering toner particles. (2) When a cross section of a glossy toner particle in the thickness direction is observed, the proportion of glossy pigments in which the angle between the long axis direction of the toner particle in the cross section and the long axis direction of the glossy pigment is in the range of -30° to +30° is 60% or more of all the glossy pigments observed.

[0089] (Method of manufacturing glittering toner) The glitter toner can be obtained, for example, by producing glitter toner particles and then externally adding an external additive to the glitter toner particles.

[0090] The glittering toner particles may be produced by any of a dry production method (e.g., a kneading and pulverizing method, etc.) and a wet production method (e.g., an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method, etc.). There are no particular limitations on these production methods, and any known production method may be used. Among these, it is preferable to obtain glittering toner particles by the aggregation and coalescence method.

[0091] [Developer] The developer may be a one-component developer containing only glitter toner, or a two-component developer in which glitter toner is mixed with a carrier.

[0092] The carrier is not particularly limited, and may be any known carrier, such as a coated carrier in which the surface of a core material made of magnetic powder is coated with a coating resin, a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin, or a resin impregnated type carrier in which porous magnetic powder is impregnated with a resin. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and are coated with a coating resin.

[0093] In the two-component developer, the mixture ratio (mass ratio) of the toner and the carrier is preferably toner:carrier=1:100 to 30:100, and more preferably 3:100 to 20:100.

[0094] [Fixing device] The unit and the fixing device of the image forming apparatus according to this embodiment will be described in further detail below. 3 is a schematic diagram showing an example of a fixing device (that is, a specific fixing device) of the unit and the image forming apparatus according to the present embodiment. Note that FIG. 3 shows only the main parts of the fixing device.

[0095] The fixing device shown in FIG. 3 includes, for example, a fixing belt 202, a fixing roll 204 (an example of a first roll) and a heating roll 206 (an example of a second roll) arranged inside the fixing belt 202, and a pressure roll 208 arranged opposite the fixing roll 204 with the fixing belt 202 interposed therebetween.

[0096] The fixing belt 202 is supported by a fixing roll 204 and a pressure roll 208 while being given tension. The pressure roll 208 is disposed so as to sandwich the fixing belt 202 with the fixing roll 204 to form a nip portion (that is, a contact portion) N.

[0097] The fixing belt 202 is configured as an endless belt in which, for example, a base layer, an elastic layer, and a release layer are laminated in this order. The substrate layer is composed of a layer of a heat-resistant resin such as a polyimide resin, an aromatic polyamide resin, a polyester resin, a polyethylene terephthalate resin, a polyethersulfone resin, a polyetherketone resin, a polysulfone resin, or a polyimideamide resin. The elastic layer is made of a layer of a heat-resistant elastic material such as silicone rubber or fluororubber. The release layer is composed of a layer of a heat-resistant release agent such as fluororubber, fluororesin, silicone resin, or polyimide resin. The base layer, the elastic layer, and the release layer may contain well-known additives, such as a conductive agent, a filler, and the like.

[0098] The fixing roll 204 is configured, for example, of a roll having a metal roll and an elastic layer provided on the outer circumferential surface of the metal roll. The heating roll 206 is composed of, for example, a metal roll incorporating a heat source (such as a halogen lamp) and a roll having an elastic layer provided on the outer circumferential surface of the metal roll. The pressure roll 208 is composed of, for example, a metal roll incorporating a heat source (such as a halogen lamp) and a roll having an elastic layer provided on the outer circumferential surface of the metal roll. The metal roll is made of, for example, a hollow roll of copper, aluminum, stainless steel (SUS), sulfur-containing steel (SUM), various alloys, or the like. The elastic layer is made of a heat-resistant elastic material such as silicone rubber, fluororubber, etc. The elastic layer may contain well-known additives such as a conductive agent, a filler, etc.

[0099] 3, the fixing roll 204 and the pressure roll 208 are arranged in pressure contact with each other in a state where their elastic layers are crushed via the fixing belt 202. This forms a flat nip portion N. In order to make the nip portion N flat, for example, the fixing roll 204 (an example of a first roll) and the pressure roll 208 may adopt the following configuration. 1) The difference (absolute value) in surface hardness between the fixing roll 204 and the pressure roll 208 is within 15°. 2) The surface hardness of the fixing roll 204 is 35° or more and 45° or less. 3) The surface hardness of the pressure roll 208 is 40° or more and 50° or less. 4) The pressure at the nip N is 2.0 kgf / cm 2 More than 7.0kgf / cm 2 Less than or equal to 4.0kgf / cm 2 More than 7.0kgf / cm 2 The fixing roll 204 and the pressure roll 208 are arranged with a load applied thereto so that the following condition is satisfied: 5) The outer diameter ratio of the fixing roll 204 to the pressure roll 208 (fixing roll 204 / pressure roll 208) is 0.9 or more and 1.3 or less.

[0100] By adopting the above-mentioned aspects 1) to 5) of the fixing roll 204 (an example of a first roll) and the pressure roll 208, the nip portion N becomes flat.

[0101] Here, the surface hardness of the roll is an Asker C hardness, which is a hardness measured by an Asker C hardness tester.

[0102] 3, while the fixing belt 202, the fixing roll 204, the heating roll 206, and the pressure roll 208 are rotating, the fixing belt 202 is heated from its inner circumferential surface by the heat source of the heating roll 206, and the nip portion N is directly heated by the heat source of the pressure roll 208. The linear velocity of the fixing belt 202 at this time is, for example, 180 mm / sec or more and 450 mm / sec or less. Then, the recording medium P onto which the toner image T has been transferred is passed through the nip portion with the fixing temperature (i.e., the temperature of the nip portion) being set to 130° C. or higher and 230° C. or lower. As a result, the toner image T is fixed onto the recording medium P, and an image is formed.

[0103] Here, by setting the fixing temperature (i.e., the temperature of the nip portion) to 130°C or higher and 230°C or lower, even in the fixing device shown in Fig. 3 (i.e., the specific fixing device), the toner image made of the glittering toner is sufficiently melted in the nip portion N, and the glittering pigment is easily parallelized to the surface of the recording medium. As a result, a glittering image with a high glittering feel can be formed by the glittering toner.

[0104] In addition, by rotating the fixing belt at a linear velocity of 180 mm / sec or more and 450 mm / sec or less, even in the fixing device shown in Fig. 3 (i.e., the specific fixing device), sufficient heat is applied to the toner image made of the glittering toner in the nip N, the toner image is further melted, and the glittering pigment is easily parallelized to the surface of the recording medium. This makes it possible to form a glittering image with a high glittering feel using the glittering toner.

[0105] It should be noted that the fixing device shown in FIG. 3 is not limited to the above configuration as long as it corresponds to a specific fixing device. The fixing device shown in FIG. 3 may be configured to include, for example, instead of the heating roll 206, a metal roll that supports the fixing belt 202 and heats it by electromagnetic induction, and an electromagnetic induction unit that is disposed opposite the fixing belt 202 and has an electromagnetic induction coil.

[0106] Here, the image forming apparatus including the fixing device according to the present embodiment includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage, a communication interface, an input unit, and a display unit, all of which are not shown in the figure. Each component is connected to be able to communicate with each other via a bus 28. The CPU is a central processing unit that executes various programs and controls each part. That is, the CPU reads the programs from the ROM or storage and executes the programs using the RAM as a working area. The CPU controls each of the above components and performs various calculation processes according to the programs recorded in the ROM or storage. The ROM stores various programs and various data. RAM temporarily stores programs and data as a working area. The storage is configured with a storage device such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory, and stores various programs including an operating system, and various data. The communication interface is an interface for communicating with other devices, for example, using a wired communication standard such as Ethernet (registered trademark) or FDDI, or a wireless communication standard such as 4G, 5G, or Wi-Fi (registered trademark). The input unit includes a pointing device such as a mouse, and a keyboard, and is used to perform various input operations. The display unit is, for example, a liquid crystal display that displays various information. The display unit may be a touch panel type and function as an input unit.

[0107] For example, the ROM or storage stores a program for controlling the fixing temperature of the fixing device, a program for controlling the rotation speed of the fixing belt (for example, a program for controlling a motor that drives the rotation of the fixing roll), etc. The fixing device is controlled by the CPU reading and executing the programs stored in the ROM or storage.

[0108] In addition, the processing executed by the CPU after reading the software (program) in each of the above embodiments may be executed by various processors other than the CPU. In this case, examples of the processor include a PLD (Programmable Logic Device) such as an FPGA (Field-Programmable Gate Array) whose circuit configuration can be changed after manufacture, and a dedicated electric circuit such as an ASIC (Application Specific Integrated Circuit) which is a processor having a circuit configuration designed exclusively for executing a specific processing. In addition, the processing may be executed by one of these various processors, or may be executed by a combination of two or more processors of the same or different types (for example, a plurality of FPGAs, a combination of a CPU and an FPGA, etc.). In addition, the hardware structure of these various processors is, more specifically, an electric circuit that combines circuit elements such as semiconductor elements.

[0109] Although the present embodiment has been described above, the present invention is not limited to the above embodiment, and various modifications, changes, and improvements are possible. EXAMPLES

[0110] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. In the following description, unless otherwise specified, all "parts" and "%" are based on mass.

[0111] <Developer> [Developer (1)] (Synthesis of binder resin) Dimethyl fumarate: 74 parts Dimethyl terephthalate: 192 parts Bisphenol A ethylene oxide 2 mole adduct: 216 parts Bisphenol A propylene oxide 2 mole adduct: 48 parts Ethylene glycol: 38 parts Tetrabutoxytitanate (catalyst): 0.037 parts,

[0112] The above components were placed in a heated and dried two-necked flask, nitrogen gas was introduced into the container to maintain an inert atmosphere, and the temperature was raised while stirring, after which a polycondensation reaction was carried out at 160°C for 7 hours, after which the pressure was gradually reduced to 10 Torr while the temperature was raised to 220°C and maintained for 4 hours. The pressure was once returned to normal, 9 parts of trimellitic anhydride was added, the pressure was gradually reduced again to 10 Torr, and the mixture was maintained at 220°C for 1 hour to synthesize a binder resin.

[0113] (Preparation of Resin Particle Dispersion) Binder resin: 160 parts Ethyl acetate: 233 parts Sodium hydroxide solution (0.3N): 0.1 part

[0114] The above components were placed in a 1000 ml separable flask, heated to 70°C, and stirred with a Three-One Motor (Shinto Scientific Co., Ltd.) to prepare a resin mixture. While stirring this resin mixture at 90 rpm, 373 parts of ion-exchanged water was gradually added to cause phase inversion emulsification and desolvation to obtain a resin particle dispersion (solid concentration: 30%). The volume average particle diameter of the resin particle dispersion was 162 nm.

[0115] (Preparation of release agent dispersion) Carnauba wax (Toa Kasei Co., Ltd., RC-160): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1.0 part -Ion-exchanged water: 200 parts

[0116] The above ingredients were mixed and heated to 95°C, and dispersed using a homogenizer (Ultra Turrax T50, manufactured by IKA Corporation). After that, a dispersion treatment was carried out for 360 minutes using a Manton-Gaulin high pressure homogenizer (Gaulin Corporation) to prepare a release agent dispersion liquid (solid content concentration: 20%) in which release agent particles having a volume average particle diameter of 0.23 μm were dispersed.

[0117] (Preparation of Metal Pigment Particle Dispersion) Aluminum pigment (Showa Aluminum Powder Co., Ltd., 2173EA): 100 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R): 1.5 parts Ion-exchanged water: 900 parts

[0118] After removing the solvent from the aluminum pigment paste, the above was mixed, dissolved, and dispersed for about 1 hour using an emulsifying disperser Cavitron (manufactured by Pacific Machinery Co., Ltd., CR1010) to prepare a metal pigment particle dispersion (solid content concentration: 10%) in which metal pigment particles (aluminum pigment) were dispersed. The average length in the major axis direction of the aluminum pigment (lustrous pigment) was 8 μm, and the average length in the thickness direction was 0.1 μm.

[0119] (Preparation of Glittering Toner (1)) ·Resin particle dispersion: 380 parts Release agent dispersion: 72 parts Metal pigment particle dispersion: 140 parts

[0120] The above-mentioned metal pigment particle dispersion, resin particle dispersion, and release agent dispersion were placed in a 2 L cylindrical stainless steel container, and dispersed and mixed for 10 minutes while applying shear force at 4000 rpm using a homogenizer (IKA Ultra Turrax T50). Next, 1.75 parts of a 10% aqueous nitric acid solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5000 rpm to disperse and mix for 15 minutes to obtain a raw material dispersion.

[0121] Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer using two paddle stirring blades and a thermometer, the stirring speed was set to 810 rpm, heating was started with a mantle heater, and aggregated particles were grown at 54° C. At this time, the pH of the raw material dispersion was controlled in the range of 2.2 to 3.5 with 0.3 N nitric acid or 1 N sodium hydroxide aqueous solution. The pH was maintained in the above range for about 2 hours to form aggregated particles.

[0122] Next, the resin particle dispersion liquid was added, and the resin particles of the binder resin were attached to the surface of the aggregated particles. The temperature was further increased to 56°C, and the aggregated particles were adjusted while checking the particle size and shape with an optical microscope and a Multisizer II. Thereafter, the pH was increased to 8.0 to fuse the aggregated particles, and the temperature was increased to 67.5°C. After confirming that the aggregated particles were fused with an optical microscope, the pH was lowered to 6.0 while maintaining the temperature at 67.5°C, and heating was stopped after 1 hour, and the mixture was cooled and flattened at a temperature drop rate of 0.1°C / min. The mixture was then sieved through a 20 μm mesh, washed repeatedly with water, and dried in a vacuum dryer to obtain glittering toner particles.

[0123] 100 parts of the heat-treated glittering toner particles were mixed with 1.5 parts of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) using a sample mill at 10,000 rpm for 30 seconds. The mixture was then sieved using a vibrating sieve with 45 μm openings to produce glittering toner (1).

[0124] The average maximum thickness C of the glittering toner particles was 4.27 μm, and the average equivalent circle diameter D of the glittering toner particles was 13.6 μm.

[0125] (Creating the carrier) Ferrite particles (volume average particle size: 35 μm): 100 parts Toluene: 14 parts Perfluorooctylethyl acrylate / methyl methacrylate copolymer: 1.6 parts Carbon black (product name: VXC-72, manufactured by Cabot Corporation): 0.12 parts Crosslinked melamine resin particles (average particle size: 0.3 μm, insoluble in toluene): 0.3 parts

[0126] First, carbon black was diluted with toluene and added to perfluorooctylethyl acrylate / methyl methacrylate copolymer, and dispersed with a sand mill. Next, the above-mentioned components other than ferrite particles were dispersed in the mixture with a stirrer for 10 minutes to prepare a coating layer forming solution. Next, the coating layer forming solution and ferrite particles were placed in a vacuum degassing kneader, stirred at a temperature of 60°C for 30 minutes, and then the pressure was reduced to remove the toluene, forming a resin coating layer and obtaining a carrier.

[0127] (Preparation of developer) 36 parts of the glitter toner and 414 parts of the carrier were placed in a 2-liter V blender and stirred for 20 minutes, and then sieved through a 212 μm sieve to prepare a developer.

[0128] [Developer (2)] The binder resin was synthesized as follows. Dimethyl fumarate: 87 parts Dimethyl terephthalate: 192 parts Bisphenol A ethylene oxide 2 mole adduct: 216 parts Bisphenol A propylene oxide 2 mole adduct: 48 parts Tetrabutoxytitanate (catalyst): 0.037 parts The above components were placed in a heated and dried two-necked flask, nitrogen gas was introduced into the vessel to maintain an inert atmosphere, and the temperature was raised while stirring, after which a polycondensation reaction was carried out at 160°C for 7 hours, after which the pressure was gradually reduced to 10 Torr while the temperature was raised to 220°C and held for 4 hours. The pressure was once returned to normal, the pressure was gradually reduced again to 10 Torr, and the mixture was held at 220°C for 1 hour to synthesize a binder resin. A glittering toner (2) was obtained in the same manner as for the glittering toner (1), except that the obtained binder resin was used. A developer (2) was obtained in the same manner as the developer (1), except that the obtained glittering toner (2) was used. The average maximum thickness C of the glittering toner particles was 1.95 μm, and the average equivalent circle diameter D of the glittering toner particles was 15.6 μm.

[0129] [Developer (3)] A binder resin was obtained in the same manner as in the synthesis of the binder resin in the preparation of the glittering toner (1), except that 82 parts of dimethyl adipate was used instead of 74 parts of dimethyl fumarate. A glittering toner (3) was obtained in the same manner as for the glittering toner (1), except that the obtained binder resin was used. A developer (3) was obtained in the same manner as the developer (1), except that the obtained glittering toner (3) was used. The average maximum thickness C of the glitter toner was 1.133 μm, and the average equivalent circle diameter D of the glitter toner particles was 10.3 μm.

[0130] [Developer (4)] A binder resin was obtained in the same manner as in the synthesis of the binder resin in the preparation of the brilliant toner (1), except that 82 parts of dimethyl adipate were used instead of 74 parts of dimethyl fumarate, the number of parts of bisphenol A propylene oxide 2 mole adduct was changed to 147 parts instead of 48 parts, and trimellitic anhydride was not used. A glittering toner (4) was obtained in the same manner as for the glittering toner (1), except that the obtained binder resin was used. A developer (4) was obtained in the same manner as the developer (1), except that the obtained glittering toner (4) was used. The average maximum thickness C of the glittering toner particles was 2.22 μm, and the average equivalent circle diameter D of the glittering toner particles was 5.4 μm.

[0131] [Developer (5)] A binder resin was obtained in the same manner as in the synthesis of the binder resin in the preparation of the brilliant toner (1), except that 82 parts of dimethyl adipate were used instead of 74 parts of dimethyl fumarate, the number of parts of bisphenol A propylene oxide 2 mole adduct was changed to 147 parts instead of 48 parts, and the number of parts of trimellitic anhydride was changed to 12 parts instead of 9 parts. Glittering toner (5) was obtained in the same manner as for glittering toner (1), except that the obtained binder resin was used. However, glittering toner (5) was obtained by adjusting the viscosity at 130°C to the value shown in Table 1. A developer (4) was obtained in the same manner as the developer (1), except that the obtained glittering toner (5) was used. The average maximum thickness C of the glittering toner particles was 4.27 μm, and the average equivalent circle diameter D of the glittering toner particles was 8.1 μm.

[0132] <Examples 1 to 26 and Comparative Examples 1 to 2> The developer shown in Table 1 was filled into the developing device for forming a glossy image in a modified image forming device "Versant3100iPress" manufactured by Fuji Xerox Co., Ltd. (a modified device equipped with a fixing device having the same configuration as the fixing device shown in Figure 3). However, the configuration of the fixing device was set as shown in Table 1. The nip shape in the fixing device shown in Example 26 is nearly flat and slightly curved. Then, the following evaluations were carried out using this image forming apparatus.

[0133] (Brilliance evaluation) Using the image forming apparatus of each example, a glitter toner was applied to OK topcoat paper (basis weight 127: manufactured by Oji Paper Co., Ltd.) with a loading amount of 3.5 g / m 2 Then, 20 glossy solid images measuring 5cm x 5cm were printed out. The 20th glitter solid image was measured using a GC5000L spectroscopic variable angle color difference meter manufactured by Nippon Denshoku Industries Co., Ltd. as a variable angle photometer by irradiating light at an incident angle of -45° onto the solid image, and the reflectance X at an acceptance angle of +30° and the reflectance Y at an acceptance angle of -30° were measured. The reflectance X and reflectance Y were measured at 20 nm intervals for light with wavelengths ranging from 400 nm to 700 nm, and the average reflectance at each wavelength was calculated. From these measurement results, the ratio (X / Y) was calculated and evaluated according to the following criteria. The higher the ratio (X / Y), the more brilliant the color. The lower the ratio (X / Y), the more dull the color and the less brilliant the color. A: Ratio (X / Y) is between 80 and 100 B: Ratio (X / Y) is 60 or more and less than 80 C: Ratio (X / Y) is 2 or more and less than 60 D: Ratio (X / Y) is less than 2

[0134] [Table 1]

[0135] From the above results, it is understood that the present embodiment can form a glossy image with a high glossiness due to the glossy toner, as compared with the comparative example. [Explanation of symbols]

[0136] 2. Flat toner particles 4. Flat pigments L Thickness of flat toner particles 111Y, 111M, 111C, 111K, 111B photoconductor 113 Driving Roll 112 Support roll 114 Opposing Roll 115Y, 115M, 115C, 115K, 115B Cleaning device 116 Intermediate transfer belt cleaning device 117Y, 117M, 117C, 117K, 117B Primary transfer roll 118Y, 118M, 118C, 118K, 118B Charging Roll 119Y, 119M, 119C, 119K, 119B Exposure equipment 120Y, 120M, 120C, 120K, 120B developing device 133 Intermediate transfer belt 134 Secondary transfer roll 135 Fixing device 140Y, 140M, 140C, 140K, 140B toner cartridges 150Y, 150M, 150C, 150K, 150B Image forming unit

Claims

1. a developing device that contains a developer having a glittering toner that contains a flat glittering pigment and has a viscosity at 130° C. of 100 Pa·s or more and 1000 Pa·s or less, and develops an electrostatic charge image formed on the surface of an image carrier into a toner image by using the developer; a fixing device for fixing a toner image onto a surface of a recording medium, the fixing device comprising: a fixing belt; a first roll and a second roll disposed inside the fixing belt for supporting the fixing belt while applying tension to the fixing belt; and a pressure roll for sandwiching the fixing belt together with the first roll to form a nip portion, the fixing device having a fixing temperature of 130° C. or more and 230° C. or less; A unit equipped with.

2. A unit as described in claim 1, wherein the viscosity of the photoluminescent toner at 130°C is 150 Pa·s or more and 800 Pa·s or less.

3. A unit as claimed in claim 1 or claim 2, wherein the nip portion is flat.

4. 4. The unit according to claim 1, wherein the fixing belt is rotationally driven at a linear velocity of 180 mm / sec or more and 450 mm / sec or less.

5. The unit according to any one of claims 1 to 4, wherein a difference (absolute value) in surface hardness, which is an Asker C hardness, between the first roll and the pressure roll is within 15°.

6. The unit according to claim 5 , wherein the surface hardness of the first roll is 35° or more and 45° or less.

7. 7. The unit according to claim 5 or 6, wherein the surface hardness of the pressure roll is 40° or more and 50° or less.

8. The pressure at the nip is 2.0 kgf / cm ２ More than 7.0 kgf / cm ２ The unit according to any one of claims 5 to 7, wherein:

9. The pressure at the nip is 4.0 kgf / cm ２ More than 7.0 kgf / cm ２ The unit according to any one of claims 5 to 7, wherein:

10. The unit according to any one of claims 5 to 9, wherein an outer diameter ratio between the first roll and the pressure roll (first roll / pressure roll) is 0.9 or more and 1.3 or less.

11. The unit according to any one of claims 1 to 10, wherein the ratio (C / D) of the average maximum thickness C to the average equivalent circular diameter D of the toner particles of the glittering toner is in the range of 0.001 or more and 0.700 or less.

12. a toner image forming device including an image carrier and the developing device of the unit according to any one of claims 1 to 11, the toner image forming device forming a toner image on a surface of the image carrier; a transfer device that transfers the toner image formed on the surface of the image carrier onto a surface of a recording medium; A fixing device that fixes the toner image on a surface of the recording medium, the fixing device being one of the units according to any one of claims 1 to 11; An image forming apparatus comprising:

Images