Electrostatic image developing toner set, electrostatic image developer set, toner cartridge set, process cartridge, image forming apparatus, and image forming method

Abstract

To provide an electrostatic image developing toner set capable of achieving both suppression of a phenomenon in which toner becomes excessively melted during fixing of a toner image and adheres to a fixing member, and suppression of a phenomenon in which toner that is insufficiently melted due to an insufficient amount of heat supplied to toner during fixing of a toner image is transferred to a fixing member.SOLUTION: An electrostatic image developing toner set includes: a yellow toner including a yellow pigment; a magenta toner including a magenta pigment; a cyan toner including a cyan pigment; a black toner including a black pigment; a first toner that is a dye toner or a transparent toner, the first toner having a crystallization temperature T1 of 80°C or more and 95°C or less; and a second toner that is a dye toner or a transparent toner, the second toner having a crystallization temperature T2 of 60°C or more and 75°C or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a toner set for developing an electrostatic image, an electrostatic image developer set, a toner cartridge set, a process cartridge, an image forming apparatus, and an image forming method. [Background technology]

[0002] Patent Document 1 discloses a resin particle set comprising fluorescent resin particles containing a fluorescent colorant and colored resin particles containing a colored colorant, the fluorescent resin particles having a volume average particle size larger than the volume average particle size of the colored resin particles and the fluorescent resin particles having an average circularity of 0.93 or more, and also discloses that the fluorescent resin particles and the colored resin particles are used as a toner for developing electrostatic images.

[0003] Patent Document 2 discloses a toner set for use in an image forming apparatus, which includes a fluorescent toner containing a binder resin and a fluorescent agent, and a color toner containing a binder resin and a colorant, in which the 60 degree glossiness Gf of a solid image of the fluorescent toner is 10 or more and 25 or less, and the difference (Gn-Gf) between the 60 degree glossiness Gn of the solid image of the color toner and the 60 degree glossiness Gf of the solid image of the fluorescent toner is 10 or more and 28 or less. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-127427 [Patent Document 2] JP 2019-056905 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure has an objective of providing a toner set for developing electrostatic images, which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which, compared to a case in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C, suppresses a phenomenon in which the toner melts excessively when a toner image is fixed and adheres to the fixing member (hereinafter also referred to as "hot offset"), and suppresses a phenomenon in which the toner that is not sufficiently melted transfers to the fixing member due to an insufficient amount of heat supplied to the toner when a toner image is fixed (hereinafter also referred to as "cold offset"). [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment; a first toner which is a dye toner or a transparent toner and has a crystallization temperature T1 of 80° C. or more and 95° C. or less; a second toner which is a dye toner or a transparent toner and has a crystallization temperature T2 of 60° C. or more and 75° C. or less; A toner set for developing electrostatic images comprising: <2> The difference between the crystallization temperature T1 and the crystallization temperature T2 is 15° C. or more. <1> 2. A toner set for developing electrostatic images according to claim 1 . <3> The difference between the crystallization temperature T1 and the crystallization temperature T2 is 20° C. or more. <2> 2. A toner set for developing electrostatic images according to claim 1 . <4> When the average value of the crystallization temperatures of the yellow toner, the magenta toner, the cyan toner, and the black toner is defined as a crystallization temperature T3, The difference between the crystallization temperature T1 and the crystallization temperature T3 is 5° C. or less, and the difference between the crystallization temperature T2 and the crystallization temperature T3 is 20° C. or more. <1> ~ <3> 10. The toner set for developing an electrostatic image according to claim 9, <5> the first toner includes first toner particles containing a crystalline resin and a particulate material; The second toner includes second toner particles containing a crystalline resin. <1> ~ <4> 10. The toner set for developing an electrostatic image according to claim 9, <6> The granules are colorless and transparent; <5> 2. A toner set for developing electrostatic images according to claim 1 . <7> The particulate matter is silica particles. <5> or <6> 2. A toner set for developing electrostatic images according to claim 1 . <8> The content of the particulate matter contained in the first toner is 1% by mass or more and 5% by mass or less. <5> ~ <7> 10. The toner set for developing an electrostatic image according to claim 9,

[0007] <9> <1> ~ <8> a yellow developer, a magenta developer, a cyan developer, and a black developer each containing the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a first developer containing the first toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a second developer containing the second toner of the toner set for developing an electrostatic image according to any one of the above items; Electrostatic image developer set comprising: <10> <1> ~ <8> a yellow toner cartridge, a magenta toner cartridge, a cyan toner cartridge, and a black toner cartridge each including the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a first toner cartridge including the first toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a second toner cartridge including the second toner of the toner set for developing an electrostatic image according to any one of the above items; having A toner cartridge set that is detachably attached to an image forming apparatus. <11> <9> a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit each including the yellow developer, the magenta developer, the cyan developer, and the black developer separately, from the electrostatic image developer set described in <9> a first developing means including the first developer in the electrostatic image developer set according to the above item 1; <9> a second developing means including the second developer of the electrostatic image developer set according to claim 1; Equipped with A process cartridge that is detachably attached to an image forming apparatus. <12> <1> ~ <8> a yellow image forming unit, a magenta image forming unit, a cyan image forming unit, and a black image forming unit for forming a yellow image, a magenta image, a cyan image, and a black image, respectively, using the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a first image forming means for forming a first image by the first toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a second image forming means for forming a second image by the second toner of the toner set for developing an electrostatic image according to any one of the above items; a transfer means for transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing unit that fixes a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming apparatus comprising: <13> The toner image has a layer farthest from the recording medium as the first image and a layer second farthest from the recording medium as the second image. <12> 2. The image forming apparatus according to claim 1 . <14> <1> ~ <8> a yellow image forming step, a magenta image forming step, a cyan image forming step, and a black image forming step, in which a yellow image, a magenta image, a cyan image, and a black image are formed by using the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a first image forming step of forming a first image by the first toner of the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a second image forming step of forming a second image by the second toner of the toner set for developing an electrostatic image according to any one of the above items; a transfer step of transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing step of fixing a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming method comprising: <15> The toner image has a layer farthest from the recording medium as the first image and a layer second farthest from the recording medium as the second image. <14> The image forming method according to claim 1. Effect of the Invention

[0008] <1> , <5> , <6> or <7> According to the invention, there is provided a toner set for developing electrostatic images, which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which, compared to a case in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C, suppresses the phenomenon in which the toner melts excessively when the toner image is fixed and adheres to the fixing member (hereinafter also referred to as "hot offset"), and suppresses the phenomenon in which the toner that is not sufficiently melted transfers to the fixing member due to an insufficient amount of heat supplied to the toner when the toner image is fixed (hereinafter also referred to as "cold offset"). <2> According to the present invention, there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, as compared with a case in which the difference between the crystallization temperature T1 and the crystallization temperature T2 is less than 15°C. <3> According to the present invention, there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, as compared with a case in which the difference between the crystallization temperature T1 and the crystallization temperature T2 is less than 20°C. <4> According to the present invention, a toner set for developing electrostatic images is provided which suppresses both hot offset and cold offset, compared to when the difference between the crystallization temperature T1 and the crystallization temperature T3 is less than 5°C or the difference between the crystallization temperature T2 and the crystallization temperature T3 is less than 20°C. <8> According to the present invention, a toner set for developing electrostatic images is provided which suppresses both hot offset and cold offset, compared to when the particulate content in the first toner is less than 1% by mass or more than 5% by mass.

[0009] <9> , <10> , <11> , <12> or <14> According to the invention, there is provided an electrostatic image developer set, a toner cartridge set, a process cartridge, an image forming apparatus, or an image forming method which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner, or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which achieves both suppression of hot offset and suppression of cold offset compared to the application of a toner set for developing electrostatic images in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C. <13> or <15> According to the invention, even if the layer farthest from the recording medium is a first image and the layer second farthest from the recording medium is a second image, an image forming apparatus or image forming method is provided that includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner or a transparent toner, and a second toner which is a dye toner or a transparent toner, and that achieves both suppression of hot offset and suppression of cold offset compared to the case of applying a toner set for developing electrostatic images in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°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 the present disclosure. [Diagram 2] 1 is a schematic configuration diagram illustrating an example of a process cartridge that is detachably attached to an image forming apparatus according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are merely illustrative of the embodiments, and are not intended to limit the scope of the embodiments.

[0012] In the present disclosure, a numerical range indicated using "~" indicates a range that includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.

[0013] In the present disclosure, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0014] When an embodiment of the present disclosure is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, 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.

[0015] In the present disclosure, each component may contain multiple types of corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In the present disclosure, the particles corresponding to each component may include multiple types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0016] In the present disclosure, "(meth)acrylic" is an expression that includes both acrylic and methacrylic, and "(meth)acrylate" is an expression that includes both acrylate and methacrylate. In the present disclosure, the term "main component" refers to a major component, for example, a component that is contained in the largest amount (by mass) relative to the total mass of a mixture of multiple components.

[0017] In this disclosure, "toner for developing electrostatic images" will also be referred to as "toner," "toner set for developing electrostatic images" will also be referred to as "toner set," "electrostatic image developer" will also be referred to as "developer," "electrostatic image developer set" will also be referred to as "developer set," and "carrier for developing electrostatic images" will also be referred to as "carrier."

[0018] [Toner set for developing electrostatic images] A toner set according to one embodiment of the present disclosure includes a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment, a first toner which is a dye toner or a transparent toner and has a crystallization temperature T1 of 80° C. or more and 95° C. or less, and a second toner which is a dye toner or a transparent toner and has a crystallization temperature T2 of 60° C. or more and 75° C. or less.

[0019] In electrophotographic printing, process printing using yellow (Y), magenta (M), cyan (C), and black (K) is mainstream. In this process printing, a toner set including a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment is used. Hereinafter, yellow toner, magenta toner, cyan toner, and black toner will be collectively referred to as "YMCK toner."

[0020] On the other hand, with the evolution and spread of televisions, monitors, tablets, smartphones, etc., it has become common to view photos, videos, illustrations, etc. on vivid monitors. Photos and illustrations (for example, illustrations drawn on a PC, etc.) viewed on monitors not only have a wide color gamut but also bright colors. In order to reproduce this wide color gamut and bright colors, efforts have been made to form images using toner sets that further include dye toners containing dyes such as fluorescent dyes in addition to YMCK toners. In addition, toner sets that further include a transparent toner may be used for the purpose of adjusting the gloss level of an image, imparting adhesion, etc.

[0021] The toner set according to this embodiment includes, in addition to YMCK toner, a first toner which is a dye toner or a clear toner, and a second toner which is a dye toner or a clear toner. In this embodiment, the crystallization temperature T1 of the first toner is 80° C. or more and 95° C. or less, and the crystallization temperature T2 of the second toner is 60° C. or more and 75° C. or less, so that both hot offset and cold offset are suppressed. The reason for this is unclear, but is presumed to be as follows.

[0022] Image formation using a toner set including YMCK toner, a first toner, and a second toner is performed, for example, as follows. Specifically, first, a yellow image, a magenta image, a cyan image, a black image, a first image, and a second image are formed using each of the yellow toner, magenta toner, cyan toner, black toner, the first toner, and the second toner, respectively. Hereinafter, the yellow image, the magenta image, the cyan image, and the black image are collectively referred to as "YMCK image." Then, by transferring each image onto a recording medium, a toner image having six images stacked thereon is obtained, and the toner image having six images stacked thereon is then fixed onto the recording medium. At this time, in the toner image on the recording medium, for example, the first image and the second image are stacked on the side farther from the recording medium than the YMCK image.

[0023] As described above, in image formation using a toner set including the first and second toners in addition to the YMCK toners, a fixing process is performed in which a toner image, which is a stack of six images formed by each toner, is fixed onto a recording medium. Therefore, compared to image formation using a toner set consisting of only the YMCK toners, a larger amount of heat is required to fix the toner image onto the recording medium in the fixing process, and the fixing temperature is higher. When a toner image with six stacked images is fixed to a recording medium at a high fixing temperature, for example, if the crystallization temperatures of both the first toner and the second toner are low, hot offset is likely to occur. Specifically, the load of the fixing member is applied in a state in which both the first image and the second image stacked on the YMCK image and present on the fixing member side have low viscosity and are difficult to solidify. At this time, since the toner image with six stacked images is thick, the load of the fixing member is large, and the molten toner is likely to adhere to the fixing member. In particular, when an image is formed on a recording medium with a small thickness such as thin paper, the above-mentioned hot offset is likely to be noticeable. On the other hand, for example, when the crystallization temperatures of both the first toner and the second toner are high, the amount of heat supplied is insufficient for the amount of heat required to melt the toner image, and cold offset is likely to occur. In particular, when an image is formed on a thick recording medium such as cardboard, the cold offset is likely to be significant.

[0024] In contrast, in this embodiment, the crystallization temperature T1 of the first toner is 80° C. or more and 95° C. or less, and the crystallization temperature T2 of the second toner is 60° C. or more and 75° C. or less. Therefore, compared to when the crystallization temperature T1 is less than 80° C., hot offset, which tends to occur when the crystallization temperatures of both the first toner and the second toner are low, is suppressed. Also, compared to when the crystallization temperature T2 is more than 75° C., cold offset, which tends to occur when the crystallization temperatures of both the first toner and the second toner are high, is suppressed. As a result, it is presumed that both hot offset and cold offset are suppressed.

[0025] When an image is formed using a toner set consisting of only YMCK toner and a second toner, the above-mentioned hot offset is unlikely to occur. Although the reason for this is unclear, it is speculated that this is because the second image in contact with the YMCK image is difficult to separate from the YMCK image due to the adhesiveness of the YMCK image. In addition, when forming an image using only the second toner, the above-mentioned hot offset does not occur easily. Although the reason for this is unclear, it is speculated that the second image in contact with the recording medium has an anchor effect by penetrating into the recording medium, making it difficult to peel off from the recording medium.

[0026] The toner set according to the present disclosure may include at least the YMCK toner, the first toner, and the second toner, and may include toners other than the above six types of toners (hereinafter, also referred to as other toners). Examples of other toners include pigment toners other than the YMCK toners, that is, toners containing toner particles that contain a pigment as the main component of the colorant and in which the content of the dye relative to the total mass of the colorant is less than 10% by mass.

[0027] <Crystallization temperature> The crystallization temperature of the toner is determined by differential scanning calorimetry. Specifically, the toner to be measured is placed in a Shimadzu Corporation differential scanning calorimeter (DSC-50) equipped with an automatic tangent processing system, liquid nitrogen is placed as a cooling medium, and the toner is heated from 20°C to 150°C at a temperature increase rate of 10°C / min to determine the relationship between temperature (°C) and heat (mW). The toner is then cooled to 0°C at a temperature decrease rate of -10°C / min, and the exothermic peak temperature of the temperature decrease spectrum is taken as the crystallization temperature of the toner. When multiple exothermic peaks are shown, the maximum peak is regarded as the crystallization temperature.

[0028] The crystallization temperature T1 of the first toner is 80° C. or more and 95° C. or less, and from the viewpoint of simultaneously suppressing hot offset and cold offset, it is preferably 80° C. or more and 90° C. or less, and more preferably 85° C. or more and 90° C. or less. The crystallization temperature T2 of the second toner is 60° C. or more and 75° C. or less, and from the viewpoint of simultaneously suppressing hot offset and cold offset, it is preferably 60° C. or more and 70° C. or less, and more preferably 65° C. or more and 70° C. or less.

[0029] A combination of a first toner and a second toner in which the crystallization temperature T1 and the crystallization temperature T2 are within the above ranges may be, for example, a combination of a first toner including a first toner particle containing a crystalline resin and a particulate material, and a second toner including a second toner particle containing a crystalline resin. The first toner and the second toner each preferably further contain a release agent. In other words, a combination of a first toner and a second toner in which the crystallization temperature T1 and the crystallization temperature T2 are within the above ranges is preferably a combination of a first toner including a first toner particle containing a crystalline resin, a release agent, and a particulate material, and a second toner including a second toner particle containing a crystalline resin and a release agent. It is preferable that the second toner particles do not substantially contain particulate material, that is, the content of particulate material relative to the entire second toner particles is less than 1% by mass.

[0030] It is believed that the first toner particles contain a crystalline resin and granular materials, and the granular materials serve as crystal nuclei to promote crystallization of the crystalline resin, thereby controlling the crystallization temperature T1 within the above range. In particular, when the first toner particles contain a crystalline resin, a release agent, and granular materials, it is believed that the granular materials serve as crystal nuclei to promote crystallization of the crystalline resin and the release agent, thereby controlling the crystallization temperature T1 within the above range. In addition, when the second toner particles contain a crystalline resin and do not substantially contain particulate matter, there is no material that can become a crystal nucleus, and the crystallization of the crystalline resin is not promoted, so that the crystallization temperature T2 is controlled within the above range. Similarly, when the second toner particles contain a crystalline resin and a release agent and do not substantially contain particulate matter, there is no material that can become a crystal nucleus, and the crystallization of the crystalline resin and the release agent is not promoted, so that the crystallization temperature T2 is controlled within the above range. The crystalline resin and the particulate material will be described in detail later.

[0031] From the viewpoint of simultaneously suppressing hot offset and cold offset, the difference between the crystallization temperature T1 and the crystallization temperature T2 is preferably 15° C. or more, more preferably 20° C. or more, and even more preferably 25° C. or more. The upper limit of the difference between the crystallization temperature T1 and the crystallization temperature T2 is not particularly limited, and may be, for example, 35° C. In a toner set in which the difference between the crystallization temperature T1 and the crystallization temperature T2 is equal to or greater than the lower limit, the crystallization temperature T1 is relatively high and the crystallization temperature T2 is relatively low. Therefore, hot offset is suppressed more than when both the crystallization temperature T1 and the crystallization temperature T2 are low, and cold offset is suppressed more than when both the crystallization temperature T1 and the crystallization temperature T2 are high. As a result, both the hot offset and the cold offset are suppressed.

[0032] The crystallization temperature T3, which is the average value of the crystallization temperatures of the yellow toner, the magenta toner, the cyan toner, and the black toner, is not particularly limited and may be, for example, 80°C or higher and 95°C or lower, preferably 80°C or higher and 90°C or lower, and more preferably 85°C or higher and 90°C or lower. The difference between the crystallization temperature T1 and the crystallization temperature T3 is, for example, 10° C. or less, and from the viewpoint of simultaneously suppressing hot offset and cold offset, it is preferably 5° C. or less, and more preferably 3° C. or less. The difference between the crystallization temperature T2 and the crystallization temperature T3 is, for example, 12° C. or more, and from the viewpoint of simultaneously suppressing hot offset and cold offset, is preferably 20° C. or more, and more preferably 25° C. or more. The upper limit of the difference between the crystallization temperature T2 and the crystallization temperature T3 is not particularly limited, and is, for example, 35° C.

[0033] From the viewpoint of suppressing both hot offset and cold offset, it is preferable that the difference between crystallization temperature T1 and crystallization temperature T3 is 10°C or less and the difference between crystallization temperature T2 and crystallization temperature T3 is 12°C or more, it is more preferable that the difference between crystallization temperature T1 and crystallization temperature T3 is 5°C or less and the difference between crystallization temperature T2 and crystallization temperature T3 is 20°C or more, it is even more preferable that the difference between crystallization temperature T1 and crystallization temperature T3 is 3°C or less and the difference between crystallization temperature T2 and crystallization temperature T3 is 25°C or more.

[0034] Hereinafter, each toner included in an example of the toner set according to this embodiment will be described in detail.

[0035] <YMCKトナー> The YMCK toners are not particularly limited as long as they are a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment. All of the YMCK toners are toners containing a pigment as the main component of the colorant and containing toner particles in which the content of the dye relative to the total mass of the colorant is less than 10% by mass. The YMCK toners are, respectively, conventionally known yellow toners, magenta toners, cyan toners, and black toners. The specific configuration of the YMCK toner may be the same as that of the first toner and the second toner described later, except that pigments of the respective colors are used as colorants.

[0036] <First Toner and Second Toner> The first toner and the second toner are not particularly limited as long as they are dye toners or transparent toners and have crystallization temperatures within the above-mentioned ranges. The dye toner is a toner containing a dye. The dye toner includes dye toner particles, which are toner particles containing a dye. The dye toner particles may contain a colorant other than a dye. When the dye toner particles contain a colorant other than a dye, the dye toner particles are toner particles in which the content of the dye relative to the total mass of the colorant is 10% by mass or more. The dye toner may be, for example, a fluorescent toner, that is, a toner containing toner particles containing a fluorescent dye as a dye. The fluorescent toner may be, for example, a fluorescent green toner, a fluorescent pink toner, a fluorescent red toner, a fluorescent orange toner, a fluorescent yellow toner, a fluorescent blue toner, a fluorescent purple toner, or the like. The fluorescent toner may be an invisible fluorescent toner that is normally colorless and emits light when irradiated with ultraviolet light. A transparent toner is a toner that does not substantially contain a colorant, that is, a toner in which the content of the colorant in the entire toner is less than 1% by mass. In this embodiment, both the first toner and the second toner may be dye toners, the first toner may be a dye toner and the second toner may be a clear toner, or the first toner may be a clear toner and the second toner is a dye toner.

[0037] When both the first toner and the second toner are dye toners, it is preferable that the first toner and the second toner are toners having different hues from each other. Examples of combinations of the first toner and the second toner having different hues from each other include a combination of fluorescent green toner and fluorescent pink toner, a combination of green and pink, a combination of fluorescent green and fluorescent orange, a combination of green and orange, and a combination of fluorescent yellow and fluorescent pink. When both the first toner and the second toner are dye toners, from the viewpoint of obtaining a wide color gamut, the difference in hue angle between the first toner and the second toner is preferably 120 degrees or more and 180 degrees or less, more preferably 135 degrees or more and 180 degrees or less, even more preferably 145 degrees or more and 180 degrees or less, and particularly preferably 160 degrees or more and 180 degrees or less. The difference in saturation between the first toner and the second toner is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. The difference in saturation between the first toner and the second toner may be 0 or 10 or more. The difference in brightness between the first toner and the second toner is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The difference in brightness between the first toner and the second toner may be 0 or 3 or more.

[0038] The hue angle, chroma, and brightness of the toner are measured by the following methods. The toner to be measured is placed in a Revoria Press PC1120 manufactured by Fujifilm Business Innovation Co., Ltd. Using this device, a toner load of 4.0 g / m2 is measured using only the toner to be measured. 2 Under conditions of a fixing temperature of 180° C., a solid image (4.0 cm×2.5 cm) is formed on A4 size OS coated paper (127 gsm) as a recording medium. Hue angle (h), saturation (C * ), and lightness (L * ) is measured 10 times at random using an eXact Advanced (aperture 4 mm: manufactured by X-Rite) on a solid image on a recording medium obtained by the above-mentioned method, and the color gamut of the solid image of the average value is calculated as the color reproduction measurement value (L * , a * , and b * The obtained color reproduction measurement value (L * , a * , and b * ) to the lightness (L * ) and calculate the hue angle (h) and chroma (C * ) is calculated using the following formula: Saturation (C * )=((a * ) 2 +(b * ) 2 )) 1 / 2 Hue angle (h)=tan -1 (b * / a * )

[0039] The first toner and the second toner will be described in detail below. The first toner contains first toner particles and, if necessary, an external additive. The second toner contains second toner particles and, if necessary, an external additive.

[0040] (Toner particles) Each of the first toner particles and the second toner particles contains, for example, a binder resin, and, if necessary, a colorant, a release agent, and other additives. The first toner particles and the second toner particles preferably contain a crystalline resin from the viewpoint of easily controlling the crystallization temperature T1 and the crystallization temperature T2 within the above-mentioned ranges. The crystalline resin is contained in the toner particles, for example, as one component of the binder resin constituting the toner particles. The first toner particles and the second toner particles more preferably contain a crystalline resin and a release agent from the viewpoint of easily controlling the crystallization temperature T1 and the crystallization temperature T2 within the above-mentioned ranges. In addition, the first toner particles preferably contain a particulate material from the viewpoint of easily controlling the crystallization temperature T1 within the above range. When the particulate material is a pigment, which will be described later, the particulate material is contained in the toner particles as one component of a colorant contained in the toner particles as needed. When the particulate material is an inorganic particle, which will be described later, the particulate material is contained in the toner particles as one component of other additives contained in the toner particles as needed. Each component constituting the toner particles will now be described.

[0041] -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.

[0042] As described above, the first toner particles and the second toner particles preferably contain a crystalline resin as one component of the binder resin. Moreover, it is more preferable that the first toner particles and the second toner particles contain a crystalline resin and an amorphous resin as the binder resin.

[0043] The "crystalline" nature of a resin refers to the presence of a clear endothermic peak rather than a stepwise change in the amount of endothermic heat in differential scanning calorimetry (DSC); specifically, the half-width of the endothermic peak is within 10°C when measured at a heating rate of 10 (°C / min). On the other hand, the term "amorphous" for a resin refers to a half-width exceeding 10° C., a stepwise change in endothermic heat quantity, or no clear endothermic peak being observed.

[0044] --Crystalline resin-- 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, from the viewpoints of the mechanical strength and low-temperature fixability of the toner, crystalline polyester resins are preferred as the crystalline resin.

[0045] Crystalline polyester resin The crystalline polyester resin may be, for example, a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. The crystalline polyester resin may be a commercially available product or a synthesized product. Here, the crystalline polyester resin is preferably a polycondensate using a polymerizable monomer having a linear aliphatic group rather than a polymerizable monomer having an aromatic group, since the crystalline polyester resin can easily form a crystalline structure.

[0046] Examples of polyvalent carboxylic acids include aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, etc.), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polyvalent carboxylic acid may be a trivalent or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (e.g., 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), their anhydrides, and their lower alkyl esters (e.g., carbon number 1 to 5). As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids. The polyvalent carboxylic acids may be used alone or in combination of two or more kinds.

[0047] Examples of polyhydric alcohols include aliphatic diols (for example, straight-chain aliphatic diols having 7 to 20 carbon atoms in the main chain). Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosanedecanediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferred as aliphatic diols. The polyhydric alcohol may be a trihydric or higher alcohol having a crosslinked or branched structure in combination with the diol. Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. The polyhydric alcohols may be used alone or in combination of two or more kinds.

[0048] Here, the polyhydric alcohol has an aliphatic diol content of 80 mol % or more, preferably 90 mol % or more.

[0049] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less. The weight average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh GPC HLC-8120GPC as the measuring device, a Tosoh TSKgel SuperHM-M (15 cm) column, and THF solvent. The weight average molecular weight is calculated from the measurement results using a molecular weight calibration curve created with monodisperse polystyrene standard samples.

[0050] The crystalline polyester resin can be obtained by a known manufacturing method, for example, in the same manner as the amorphous polyester described below.

[0051] -Melting temperature of crystalline resin From the viewpoint of controlling the crystallization temperature T1 within the above range, the melting temperature of the crystalline resin contained in the first toner particles is preferably 50°C or higher and 100°C or lower, more preferably 55°C or higher and 90°C or lower, and even more preferably 60°C or higher and 85°C or lower. From the viewpoint of controlling the crystallization temperature T2 within the above range, the melting temperature of the crystalline resin contained in the second toner particles is preferably 50° C. or more and 100° C. or less, more preferably 55° C. or more and 90° C. or less, and even more preferably 60° C. or more and 85° C. or less. The melting temperature 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."

[0052] Crystalline resin content From the viewpoint of controlling the crystallization temperature T1 within the above range, the content of the crystalline resin contained in the first toner particles is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and even more preferably 6% by mass or more and 10% by mass or less, based on the entire first toner particles. From the viewpoint of controlling the crystallization temperature T2 within the above range, the content of the crystalline resin contained in the second toner particles is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and even more preferably 6% by mass or more and 10% by mass or less, based on the entire second toner particles.

[0053] From the viewpoint of controlling the crystallization temperature T1 within the above range, the content of the crystalline resin contained in the first toner particles is preferably from 2% by mass to 40% by mass, more preferably from 2% by mass to 20% by mass, and even more preferably from 5% by mass to 15% by mass, relative to the total binder resin contained in the first toner particles. From the viewpoint of controlling the crystallization temperature T2 within the above range, the content of the crystalline resin contained in the second toner particles is preferably 2% by mass or more and 40% by mass or less, more preferably 2% by mass or more and 20% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, based on the total binder resin contained in the second toner particles.

[0054] --Amorphous resin-- 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.

[0055] Amorphous polyester resin The amorphous polyester resin may be, for example, a condensation polymer of a polyvalent carboxylic acid and a polyhydric alcohol. The amorphous polyester resin may be a commercially available product or a synthesized product.

[0056] Examples of polyvalent carboxylic acids include aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferable as polyvalent carboxylic acids. The polyvalent carboxylic acid may be a trivalent or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (e.g., carbon number 1 to 5) alkyl esters thereof. The polyvalent carboxylic acids may be used alone or in combination of two or more kinds.

[0057] Examples of polyhydric alcohols include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, examples of polyhydric alcohols include aromatic diols and alicyclic diols, and more preferably aromatic diols. As the polyhydric alcohol, a polyhydric alcohol having a crosslinked or branched structure of three or more may be used in combination with the diol. Examples of the polyhydric alcohol having a trihydric or higher valence include glycerin, trimethylolpropane, and pentaerythritol. The polyhydric alcohols may be used alone or in combination of two or more kinds.

[0058] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, and more preferably 50°C or higher and 65°C or lower. The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), more specifically, from the "extrapolated glass transition onset temperature" described in the method for determining glass transition temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics."

[0059] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less. The weight average molecular weight and number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh GPC HLC-8120GPC as the measuring device, a Tosoh TSKgel SuperHM-M (15 cm) column, and THF solvent. The weight average molecular weight and number average molecular weight are calculated from the measurement results using a molecular weight calibration curve created with a monodisperse polystyrene standard sample.

[0060] The amorphous polyester resin can be obtained by a known manufacturing method, for example, by carrying out the reaction while removing water and alcohol generated during condensation by setting the polymerization temperature to 180° C. or higher and 230° C. or lower, and reducing the pressure in the reaction system as necessary. If the raw material monomer is not soluble or compatible at the reaction temperature, a high boiling point solvent may be added as a solubilizing agent to dissolve it. In this case, the polycondensation reaction is carried out while distilling off the solubilizing agent. If a monomer with poor compatibility is present, it is recommended that the monomer with poor compatibility is condensed in advance with the acid or alcohol to be polycondensed, and then polycondensed with the main component.

[0061] --Binder resin content-- The content of the binder resin is, for example, 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 toner particles.

[0062] -Particulate matter- The particulate matter is not particularly limited as long as it is a particle composed of a component other than resin, and examples thereof include pigments and inorganic particles. Examples of the pigment include known pigments used as colorants, and specific examples thereof include aggregation-induced luminescent colorants and non-fluorescent pigments, which will be described later. Examples of inorganic particles include metal oxide particles such as silica, titanium oxide, zinc oxide, and tin oxide; metal compound particles such as barium sulfate, aluminum borate, and potassium titanate; and metal particles such as gold, silver, and copper. The particulate material may be used alone or in combination of two or more kinds.

[0063] When the granular material is an inorganic particle, it is preferable that the granular material is colorless and transparent from the viewpoint of easily controlling the hue of the toner while controlling the crystallization temperature. Here, the granular material being colorless and transparent means that the lightness (L * ) is 95% or more, chromaticity (a * ) is -5 or more and 5 or less, chromaticity (b * ) is between -5 and 5, and the haze value is 5% or less. Specifically, the lightness (L * ), chromaticity (a * ), and chromaticity (b * ) is measured using a spectrophotometer SE7700 (Nippon Denshoku Industries Co., Ltd.) by filling a powder sample of the granular material into a cell. Meanwhile, the haze value is measured using a haze meter HZ-V3 (Suga Test Instruments Co., Ltd.). In measuring the haze value, first, 5 g of granular material and 50 g of acetone are added to 95 g of general-purpose polyester resin and mixed with a paint shaker. Next, a film-like sample is prepared on a glass plate with a bar coater (manufactured by Daiichi Rika Co., Ltd.) to a thickness of 10 μm, and the dried sample is measured. Examples of colorless and transparent granular materials include silica, nano-sized titanium oxide (for example, titanium oxide having a volume average particle size of 100 nm or less), and nano-sized zinc oxide (for example, zinc oxide having a volume average particle size of 100 nm or less).

[0064] When the particulate material is a pigment, the volume average particle size of the particulate material is, for example, 10 nm or more and 150 nm or less, and from the viewpoint of dispersibility, it is preferably 50 nm or more and 150 nm or less, and more preferably 80 nm or more and 130 nm or less. When the particulate matter is an inorganic particle, the volume average particle size of the particulate matter is preferably from 10 nm to 150 nm, more preferably from 10 nm to 100 nm, and even more preferably from 10 nm to 50 nm, from the viewpoint of transparency. The volume average particle size of granular material is measured by using the particle size distribution obtained by measurement with a laser diffraction particle size distribution analyzer (e.g., LA-700 manufactured by Horiba, Ltd.), subtracting the cumulative distribution for the volume from the small particle size side for each divided particle size range (channel), and determining the particle size that is 50% of the total particles as the volume average particle size D50v.

[0065] From the viewpoint of controlling the crystallization temperature T1 within the above range, the content of the particulate matter contained in the first toner particles is preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 8% by mass, and even more preferably 2% by mass to 6% by mass. When the first toner particles contain multiple types of particulate matter, the content of the particulate matter means the total content of the multiple types of particulate matter.

[0066] -Coloring agent- As described above, the dye toner particles contain a dye as a main component of the colorant, and may contain a colorant other than the dye as necessary. The dye toner particles may contain only one type of colorant, or may contain two or more types of colorants. Examples of dyes include fluorescent dyes and non-fluorescent dyes. Fluorescent dyes are dyes that emit light when exposed to external light energy, and non-fluorescent dyes are dyes that do not emit light when exposed to external light energy. In general, fluorescent dyes change color when exposed to both reflected light and light, while non-fluorescent dyes change color only when exposed to reflected light. Colorants other than dyes include aggregation-induced luminescent colorants, non-fluorescent pigments, etc. An aggregation-induced luminescent colorant is a colorant that does not emit fluorescence when the molecule is alone but emits fluorescence when a large number of molecules are gathered in a crystalline state (aggregated state), i.e., has aggregation-induced emission (AIE), and a non-fluorescent pigment is a pigment that does not emit light due to external light energy.

[0067] --Fluorescent dyes-- The fluorescent dyes may include those belonging to the naphthalimides class; cationic or non-cationic coumarins class; xanthenodiquinolizines (e.g. sulforhodamines); azaxanthenes class; naphtholactams class; azlactones class; oxazines class; thiazines class; dioxazines class; monocationic or polycationic fluorescent dyes of the azo, azomethine or methine type, either alone or in mixtures.

[0068] As the fluorescent dye, for example, a fluorescent dye having a cationic group can be mentioned as a preferred example. From the viewpoint of fluorescence intensity, the cationic group is preferably an onium group, more preferably an ammonium group, an iminium group, or a pyridinium group, further preferably an ammonium group, and particularly preferably a quaternary ammonium group. In addition, the fluorescent dye may have only one cationic group or two or more cationic groups. From the viewpoint of fluorescence intensity, however, it is preferable for the fluorescent dye to have one to four cationic groups, more preferable for the fluorescent dye to have one or two cationic groups, and particularly preferable for the fluorescent dye to have only one cationic group.

[0069] Fluorescent dyes include CI Basic Red 1 (Rhodamine 6G), CI Basic Red 1:1, CI Basic Red 2, CI Basic Red 12, CI Basic Red 13, CI Basic Red 14, CI Basic Red 15, CI Basic Red 36, CI Basic Violet 7, CI Basic Violet 10 (Rhodamine B), CI Basic Violet 11 (Rhodamine 3B), CI Basic Violet 11:1 (Rhodamine A), CI Basic Violet 15, CI Basic Violet 16, CI Basic Violet 27, CI Basic Yellow 1, CI Basic Yellow 2, CI Basic Yellow 9, CI Basic Yellow 24, CI Basic Yellow 40, CI Basic Orange 15, CI Basic Orange 22, CI Basic Blue 1, CI Basic Blue 3, CI Basic Blue 7, CI Basic Blue 9, CI Basic Blue 45, CI Basic Green 1, CI Acid Yellow 3, CI Acid Yellow 7, CI Acid Yellow 73, CI Acid Yellow 87, CI Acid Yellow 184, CI Acid Yellow 245, CI Acid Yellow 250, CI Acid Red 51, CI Acid Red 52, CI Acid Red 57, CI Acid Red 77, CI Acid Red 87, CI Acid Red 89, CI Acid Red 92, CI Acid Blue 9, CI Acid Black 2, CI Solvent Yellow 43, CI Solvent Yellow 44, CI Solvent Yellow 85, CI Solvent Yellow 98, CI Solvent Yellow 116, CI Solvent Yellow 131, CI Solvent Yellow 145, CI Solvent Yellow 160:1, CI Solvent Yellow 172, CI Solvent Yellow 185, CI Solvent Yellow 195, CI Solvent Yellow 196, CI Solvent Orange 63, CISolvent Orange 112, CI Solvent Red 49, CI Solvent Red 149, CI Solvent Red 175, CI Solvent Red 196, CI Solvent Red 197, CI Solvent Blue 5, CI Solvent Green 5, CI Solvent Green 7, CI Direct Yellow 27, CI Direct Yellow 85, CI Direct Yellow 96, Direct Orange 8, CI Direct Red 2, CI Direct Red 9, CI Direct Blue 22, CI Direct Blue 199, CI Direct Green 6, CI Disperse Yellow 11, CI Disperse Yellow 82, CI Disperse Yellow 139, CI Disperse Yellow 184, CI Disperse Yellow 186, CI Disperse Yellow 199, CI Disperse Yellow 202, CI Disperse Yellow 232, CI Disperse Orange 11, CI Disperse Orange 32, CI Disperse Red 58, CI Disperse Red 274, CI Disperse Red 277, CI Disperse Red 303, CI Disperse Blue 7, CI Reactive Yellow 78, CI Bat Red 41, etc.

[0070] The fluorescent dye also includes a fluorescent pigment (pigmented fluorescent dye) in which the fluorescent dye is dispersed in a resin to form a pigment. Examples of pigmented fluorescent dyes include resin particles in which the above-mentioned various fluorescent dyes are dispersed in a resin such as melamine resin, alkyd resin, vinyl chloride resin, acrylic resin, polyester resin, amino resin, or formaldehyde condensation resin. Examples of pigmented fluorescent dyes include powdered fluorescent pigments manufactured by Shinroihi Co., Ltd. (Shinroihi Color SX-100 series, SX-200 series, SX-300 series, NEZ-100 series, etc.), fluorescent pigments manufactured by DayGlo (T series, GT series, ZQ series, GPL series, etc.), and fluorescent pigments manufactured by Nippon Fluorescent Chemical Co., Ltd. (NKV-S series, NKW-3200E series, etc.).

[0071] Fluorescent dyes also include fluorescent whitening agents. Examples of the fluorescent whitening agent include benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, stilbene derivatives, coumarin derivatives, biphenyl derivatives, naphthalimide derivatives, and benzidine derivatives. Specific examples include fluorescent whitening agent 184 and fluorescent whitening agent 393.

[0072] --Non-fluorescent dyes-- There are no limitations on the color of the non-fluorescent dye as long as it is a dye that does not have fluorescence, and examples of the non-fluorescent dye include non-fluorescent green dye, non-fluorescent red dye, non-fluorescent yellow dye, non-fluorescent pink dye, non-fluorescent orange dye, and non-fluorescent purple dye.

[0073] --Aggregation-induced luminescent color material-- The aggregation induced luminescent color material is not particularly limited as long as it has the above-mentioned characteristics. Specific examples of aggregation-induced luminescent colorants include CI Pigment Yellow 101, boron difluoride derivatives of CI Pigment Yellow 101, and 1,2,3,4-Tetrachloro-11H-isoindolo[2,1-a]benzimidazole-11-one. Among these, as the aggregation induced luminescent colorant, CI Pigment Yellow 101 is preferred from the viewpoints of saturation and fluorescence intensity.

[0074] 1,2,3,4-Tetrachloro-11H-isoindolo[2,1-a]benzimidazole-11-one is available as Radglo VSF-0-05 manufactured by Radiant Color.

[0075] --Non-fluorescent pigments-- The non-fluorescent pigment is not limited in color, etc., so long as it is a pigment that does not have fluorescence, and examples of the non-fluorescent pigment include a non-fluorescent green pigment, a non-fluorescent red pigment, a non-fluorescent yellow pigment, a non-fluorescent pink pigment, a non-fluorescent orange pigment, and a non-fluorescent purple pigment.

[0076] Examples of non-fluorescent 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, pigment orange, rose bengal, aniline blue, ultramarine blue, chalco oil blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, malachite green oxalate, titanium oxide, zinc oxide, calcium carbonate, basic lead carbonate, zinc sulfide-barium sulfate mixture, zinc sulfide, silicon dioxide, and aluminum oxide.

[0077] --Colorant content-- The content of the colorant is, for example, preferably from 0.5% by mass to 30% by mass, and more preferably from 1% by mass to 15% by mass, based on the total amount of the toner particles.

[0078] -Release agent- Examples of the release agent include hydrocarbon waxes such as microcrystalline wax, natural waxes such as carnauba wax, rice wax, candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, ester waxes such as fatty acid esters and montan acid esters, etc. The release agent is not limited to these.

[0079] From the viewpoint of controlling the crystallization temperature T1 within the above range, the melting temperature of the release agent contained in the first toner particles is preferably 50° C. or more and 110° C. or less, more preferably 60° C. or more and 100° C. or less, and even more preferably 70° C. or more and 100° C. or less. From the viewpoint of controlling the crystallization temperature T2 within the above range, the melting temperature of the release agent contained in the second toner particles is preferably 50° C. or more and 110° C. or less, more preferably 60° C. or more and 100° C. or less, and even more preferably 70° C. or more and 100° C. or less. The melting temperature 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 K 7121-1987 "Method for measuring transition temperature of plastics."

[0080] The content of the release agent is, for example, 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 toner particles.

[0081] -Other additives- Examples of other additives include well-known additives such as magnetic materials, charge control agents, inorganic particles, etc. These additives are contained in the toner particles as internal additives.

[0082] -Characteristics of toner particles, etc.- The toner particles may be toner particles having a single layer structure, or may be toner particles having a so-called core-shell structure composed of a core portion (core particle) and a coating layer (shell layer) that coats the core portion. Here, the toner particles having a core-shell structure may be composed of, for example, a core containing a binder resin and, if necessary, other additives such as a colorant and a release agent, and a coating layer containing the binder resin.

[0083] The volume average particle size (D50v) of the toner particles is preferably from 2 μm to 10 μm, and more preferably from 4 μm to 8 μm.

[0084] The various average particle sizes and particle size distribution indexes of the 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:

[0085] The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

[0086] The average circularity of toner particles is calculated by (circular equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the particle projected image)]. Specifically, it is a value measured by the following method. First, the toner particles to be measured are sucked and collected, flattened, and a still image of the particles is captured by instantaneous strobe light emission, and the particle image is analyzed by a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation). The number of samples to be taken in order to calculate the average circularity is 3,500. When the toner contains an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed.

[0087] (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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] (Toner manufacturing method) Next, a method for producing the toner according to the present embodiment will be described. The toner according to the exemplary embodiment is obtained by producing toner particles and then externally adding an external additive to the toner particles.

[0092] The 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-coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The method for producing the toner particles is not particularly limited, and a well-known production method is adopted. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

[0093] Specifically, for example, when toner particles are produced by the aggregation and coalescence method, The toner particles are manufactured through a process including a step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed (resin particle dispersion preparation process), a step of aggregating the resin particles (or other particles, if necessary) in the resin particle dispersion (in a dispersion after mixing other particle dispersions, if necessary) to form aggregated particles (aggregated particle formation process), and a step of heating the aggregated particle dispersion in which the aggregated particles are dispersed, fusing and coalescing the aggregated particles, and forming toner particles (fusion and coalescence process).

[0094] Each step will be described in detail below. In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as necessary. Of course, additives other than the colorant and the release agent may be used.

[0095] -Resin particle dispersion preparation process- First, a resin particle dispersion in which resin particles serving as a binder resin are dispersed, as well as a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared.

[0096] Here, the resin particle dispersion liquid is prepared, for example, by dispersing resin particles in a dispersion medium with the aid of a surfactant.

[0097] The dispersion medium used in the resin particle dispersion liquid is, for example, an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, alcohols, etc. These may be used alone or in combination of two or more kinds.

[0098] Examples of the surfactant include anionic surfactants such as sulfate salts, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly preferred. The nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. The surfactant may be used alone or in combination of two or more kinds.

[0099] In the resin particle dispersion, examples of the method for dispersing the resin particles in the dispersion medium include general dispersion methods using, for example, a rotary shear type homogenizer, a ball mill having a media, a sand mill, a dyno mill, etc. Depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method. The phase inversion emulsification method is a method in which the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase) to neutralize it, and then an aqueous medium (W phase) is added to effect conversion of the resin from W / O to O / W (so-called phase inversion), resulting in a discontinuous phase, and the resin is dispersed in particulate form in the aqueous medium.

[0100] The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, preferably from 0.01 μm to 1 μm, more preferably from 0.08 μm to 0.8 μm, and even more preferably from 0.1 μm to 0.6 μm. The volume average particle size of the resin particles is measured by using a particle size distribution obtained by measurement using a laser diffraction particle size distribution measuring device (e.g., LA-700 manufactured by Horiba, Ltd.), subtracting the cumulative distribution from the small particle size side for the volume of the divided particle size range (channel), and measuring the particle size at which the cumulative distribution is 50% of all particles as the volume average particle size D50v. The volume average particle sizes of particles in other dispersions are also measured in the same manner.

[0101] The content of the resin particles in the resin particle dispersion is, for example, preferably from 5% by mass to 50% by mass, and more preferably from 10% by mass to 40% by mass.

[0102] In addition, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. That is, the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion are the same for the colorant particles dispersed in the colorant particle dispersion and the release agent particles dispersed in the release agent particle dispersion.

[0103] -Agglomerated particle formation process- Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion. Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are hetero-aggregated to form aggregated particles containing the resin particles, the colorant particles, and the release agent particles and having a diameter close to that of the target toner particles.

[0104] Specifically, for example, an aggregating agent is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (e.g., pH 2 or more and 5 or less), a dispersion stabilizer is added as necessary, and then the mixed dispersion is heated to a temperature of the glass transition temperature of the resin particles (specifically, for example, a temperature of the glass transition temperature of the resin particles -30°C or more and the glass transition temperature -10°C or less), and the particles dispersed in the mixed dispersion are aggregated to form aggregated particles. In the aggregated particle formation process, for example, the above-mentioned aggregating agent may be added to the mixed dispersion at room temperature (e.g., 25°C) while stirring the mixed dispersion with a rotary shear homogenizer, the pH of the mixed dispersion may be adjusted to an acidic state (e.g., pH 2 or more and 5 or less), and a dispersion stabilizer may be added as necessary, followed by the above-mentioned heating.

[0105] Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher metal complex. In particular, when a metal complex is used as the flocculant, the amount of surfactant used is reduced and the charging characteristics are improved. If necessary, an additive that forms a complex or a similar bond with the metal ions of the flocculant may be used, and a chelating agent is preferably used as this additive.

[0106] Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, as well as inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. The chelating agent may be a water-soluble chelating agent, for example, oxycarboxylic acid such as tartaric acid, citric acid, gluconic acid, iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), etc. The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, relative to 100 parts by mass of the resin particles.

[0107] -Fusion / unification process- Next, the aggregated particle dispersion liquid in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10 to 30° C. higher than the glass transition temperature of the resin particles) to fuse and coalesce the aggregated particles, thereby forming toner particles.

[0108] Through the above steps, toner particles are obtained. Note that, after obtaining an aggregated particle dispersion liquid in which aggregated particles are dispersed, the toner particles may be manufactured through a process of further mixing the aggregated particle dispersion liquid with a resin particle dispersion liquid in which resin particles are dispersed, and aggregating the aggregated particles so that the resin particles are further attached to the surfaces of the aggregated particles to form second aggregated particles, and a process of heating the second aggregated particle dispersion liquid in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles to form toner particles having a core / shell structure.

[0109] After the fusion and coalescence process, the toner particles formed in the solution are subjected to a known washing process, solid-liquid separation process, and drying process to obtain toner particles in a dried state. In the washing step, it is preferable to carry out sufficient replacement washing with ion-exchanged water from the viewpoint of electrostatic charge. In addition, the solid-liquid separation step is not particularly limited, but it is preferable to carry out suction filtration, pressure filtration, etc. from the viewpoint of productivity. In addition, in the drying step, there is no particular limit to the method, but it is preferable to carry out freeze drying, air flow drying, fluidized drying, vibration type fluidized drying, etc. from the viewpoint of productivity.

[0110] The toner according to the present embodiment is produced, for example, by adding an external additive to the obtained toner particles in a dry state and mixing them. The mixing may be performed, for example, by using a V blender, a Henschel mixer, a Loedige mixer, etc. Furthermore, if necessary, coarse particles of the toner may be removed using a vibration sieve, an air sieve, etc.

[0111] [Electrostatic image developer set] An electrostatic image developer set according to one embodiment of the present disclosure includes a yellow developer, a magenta developer, a cyan developer, and a black developer each separately containing the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set according to the present disclosure, a first developer containing the first toner of the toner set according to the present disclosure, and a second developer containing the second toner of the toner set according to the present disclosure. Hereinafter, the yellow developer, the magenta developer, the cyan developer, and the black developer will be collectively referred to as "YMCK developer". Each electrostatic image developer may be a one-component developer containing a toner, or a two-component developer in which a toner and a carrier are mixed.

[0112] 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.

[0113] Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

[0114] Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester copolymer, straight silicone resin containing an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenolic resin, and epoxy resin. The coating resin and the matrix resin may contain other additives such as conductive particles. Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0115] Here, in order to coat the surface of the core material with a coating resin, a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent can be mentioned. The solvent is not particularly limited and may be selected taking into consideration the coating resin to be used, the suitability for application, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer, a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material, a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air, and a kneader coater method in which the core material of a carrier and the solution for forming a coating layer are mixed in a kneader coater and the solvent is removed.

[0116] 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.

[0117] [Image forming device / image forming method] An image forming apparatus / image forming method according to the present disclosure will now be described. An image forming apparatus according to one embodiment of the present disclosure includes a yellow image forming means, a magenta image forming means, a cyan image forming means, and a black image forming means for forming a yellow image, a magenta image, a cyan image, and a black image using, respectively, a yellow toner, a magenta toner, a cyan toner, and a black toner of the toner set according to the present disclosure, a first image forming means for forming a first image using a first toner of the toner set according to the present disclosure, a second image forming means for forming a second image using a second toner of the toner set according to the present disclosure, a transfer means for transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium, and a fixing means for fixing a toner image formed by stacking the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto the recording medium.

[0118] In the toner image, the first image and the second image may be laminated in contact with each other. In the present embodiment, since the crystallization temperature T1 and the crystallization temperature T2 are within the above-mentioned ranges, even if the first image and the second image are laminated in contact with each other, both the hot offset and the cold offset are suppressed. In the toner image, one of the layer farthest from the recording medium and the layer second farthest from the recording medium may be the first image, and the other may be the second image. That is, the first toner and the second toner included in the toner set according to the present disclosure may be toners for forming two layers on the side farthest from the recording medium of the toner image (that is, on the side farther from the recording medium than the image formed by the YMCK toner). In this embodiment, since the crystallization temperature T1 and the crystallization temperature T2 are each within the above range, even if the first image and the second image are the two layers on the side farthest from the recording medium of the toner image, both the hot offset suppression and the cold offset suppression are achieved. In the toner image, the layer farthest from the recording medium may be the first image, and the layer second farthest from the recording medium may be the second image. That is, the first toner included in the toner set according to the present disclosure may be a toner for forming the layer farthest from the recording medium in the toner image, and the second toner may be a toner for forming the layer second farthest from the recording medium. In this embodiment, since the crystallization temperature T1 and the crystallization temperature T2 are each within the above range, even if the first image is the layer farthest from the recording medium and the second image is the layer second farthest from the recording medium, both the hot offset suppression and the cold offset suppression are achieved.

[0119] The image forming apparatus according to the present disclosure may be provided with a yellow image forming means, a magenta image forming means, a cyan image forming means, a black image forming means, a first image forming means, and a second image forming means, each of which has an image carrier, a charging means for charging the surface of the image carrier, an electrostatic image forming means for forming an electrostatic image on the charged surface of the image carrier, and a developing means for developing the electrostatic image formed on the surface of the image carrier by an electrostatic image developer into a toner image.

[0120] In addition, the image forming apparatus according to the present disclosure may have a configuration including an image holder, a charging means for charging the surface of the image holder, an electrostatic image forming means for forming an electrostatic image on the charged surface of the image holder, and a yellow developing means, a magenta developing means, a cyan developing means, a black developing means, a first developing means, and a second developing means for developing the electrostatic image formed on the surface of the image holder as a toner image using an electrostatic image developer, as a yellow image forming means, a magenta developing means, a cyan developing means, a black developing means, a first developing means, and a second developing means, as a yellow image forming means, a magenta developing means, a cyan developing means, a black developing means, a first developing means, and a second developing means.

[0121] In the image forming apparatus according to the present disclosure, an image forming method (image forming method according to the present disclosure) is performed, which includes a yellow image forming process, a magenta image forming process, a cyan image forming process, and a black image forming process for forming a yellow image, a magenta image, a cyan image, and a black image using the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set according to the present disclosure, a first image forming process for forming a first image using a first toner of the toner set according to the present disclosure, a second image forming process for forming a second image using a second toner of the toner set according to the present disclosure, a transfer process for transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium, and a fixing process for fixing a toner image formed by stacking the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto the recording medium.

[0122] The image forming apparatus according to the present disclosure may be any of known image forming apparatuses, such as a direct transfer type apparatus in which a toner image formed on the surface of an image holder is directly transferred to a recording medium; an intermediate transfer type apparatus in which a toner image formed on the surface of an image holder is primarily transferred to the surface of an intermediate transfer body, and the toner image transferred to the surface of the intermediate transfer body is secondarily transferred to the surface of a recording medium; an apparatus equipped with a cleaning means for cleaning the surface of the image holder after the transfer of the toner image and before charging; and an apparatus equipped with a discharging means for irradiating the surface of the image holder with discharging light to discharge it after the transfer of the toner image and before charging it. In the case of an intermediate transfer type device, the transfer means has, for example, an intermediate transfer body onto whose surface a toner image is transferred, a primary transfer means 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 means which secondarily transfers the toner image transferred onto the surface of the intermediate transfer body onto the surface of a recording medium.

[0123] An example of an image forming apparatus according to the present disclosure will be described below, but the present disclosure is not limited to this example. In the following description, the main parts shown in the drawings will be described, and the description of the rest will be omitted.

[0124] In the following description, a six-unit tandem image forming apparatus in which six image forming units are arranged will be described as an example of an image forming apparatus according to the present disclosure, although the tandem image forming apparatus is not limited to this.

[0125] FIG. 1 is a schematic diagram showing an image forming apparatus according to the present disclosure, and shows a six-tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in Fig. 1 includes a first image forming unit 10G (an example of a first image forming unit), a second image forming unit 10P (an example of a second image forming unit), a yellow image forming unit 10Y (an example of a yellow image forming unit), a magenta image forming unit 10M (an example of a magenta image forming unit), a cyan image forming unit 10C (an example of a cyan image forming unit), and a black image forming unit 10K (an example of a black image forming unit), which are electrophotographic image forming units that output images of each color of green (G), pink (P), yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10G, 10P, 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. These units 10G, 10P, 10Y, 10M, 10C, and 10K may be process cartridges that are detachably attached to the image forming apparatus. In FIG. 1, pink (P) and green (G) are used, but the present invention is not limited to this.

[0126] An intermediate transfer belt (an example of an intermediate transfer body) 20 is provided below each of the units 10G, 10P, 10Y, 10M, 10C, and 10K and extends through each of the units. The intermediate transfer belt 20 is provided wrapped around a drive roll 22, a support roll 23, and an opposing roll 24 that contact the inner surface of the intermediate transfer belt 20, and runs in a direction from the first unit 10P to the sixth unit 10G. An intermediate transfer body cleaning device 21 is provided on the image bearing surface side of the intermediate transfer belt 20, facing the drive roll 22.

[0127] The developing devices (examples of developing means) 4G, 4P, 4Y, 4M, 4C, and 4K of each unit 10G, 10P, 10Y, 10M, 10C, and 10K are supplied with fluorescent green, fluorescent pink, yellow, magenta, cyan, and black toner contained in toner cartridges 8G, 8P, 8Y, 8M, 8C, and 8K, respectively.

[0128] Since the units 10G, 10P, 10Y, 10M, 10C, and 10K have the same configuration and operation, the unit 10G that forms a green image will be described here as a representative example.

[0129] The unit 10G has a photoconductor 1G that acts as an image carrier. Around the photoconductor 1G, there are sequentially arranged a charging roll (an example of a charging means) 2G that charges the surface of the photoconductor 1G to a predetermined potential, an exposure device (an example of an electrostatic image forming means) 3G 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 means) 4G that supplies toner to the electrostatic image to develop it, a primary transfer roll (an example of a primary transfer means) 5G that transfers the developed toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 6G that removes toner remaining on the surface of the photoconductor 1G after the primary transfer.

[0130] The primary transfer roll 5G is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoconductor 1G. A bias power supply (not shown) that applies a primary transfer bias is connected to the primary transfer rolls 5G, 5P, 5Y, 5M, 5C, and 5K of each 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).

[0131] The operation of forming a green image in unit 10G will be described below. First, prior to operation, the surface of the photoconductor 1G is charged to a potential of -600V to -800V by the charging roll 2G. The photoconductor 1G has a conductivity (for example, a volume resistivity of 1×10 at 20°C). -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate having a resistivity of Ωcm or less. This photosensitive layer is normally 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, the charged surface of the photosensitive member 1G is irradiated with a laser beam from an exposure device 3G in accordance with green image data sent from a control unit (not shown). As a result, an electrostatic charge image of a green image pattern is formed on the surface of the photosensitive member 1G.

[0132] An electrostatic image is an image formed on the surface of the photoconductor 1G by electrostatic charging. The laser beam from the exposure device 3G reduces the resistivity of the irradiated parts of the photosensitive layer, causing the charged charges on the surface of the photoconductor 1G 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 1G rotates to a predetermined developing position as the photoconductor 1G travels. At this developing position, the electrostatic image on the photoconductor 1G is developed into a toner image by the developing device 4G and made visible.

[0133] The developing device 4G contains an electrostatic image developer including at least fluorescent green toner and a carrier. The fluorescent green toner is triboelectrically charged by stirring inside the developing device 4G, 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 1G. As the surface of the photoconductor 1G passes through the developing device 4G, the fluorescent green toner electrostatically adheres to the discharged latent image portion on the surface of the photoconductor 1G, and the latent image is developed with the fluorescent green toner. The photoconductor 1G on which the fluorescent green toner image has been formed continues to travel at a predetermined speed, and the toner image developed on the photoconductor 1G is transported to a predetermined primary transfer position.

[0134] When the fluorescent green toner image on the photoconductor 1G is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5G, and an electrostatic force from the photoconductor 1G toward the primary transfer roll 5G acts on the toner image, causing the toner image on the photoconductor 1G to be transferred onto the intermediate transfer belt 20. 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 unit 10G.

[0135] After the toner image is transferred to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with a cleaning blade provided in the photoreceptor cleaning device 6G. The toner remaining on the photoreceptor 1G is removed and collected by the photoreceptor cleaning device 6G.

[0136] The intermediate transfer belt 20 is conveyed through units 10G, 10P, 10Y, 10M, 10C, and 10K in order, and the toner images of the respective colors are transferred and superimposed.

[0137] The intermediate transfer belt 20 onto which the six color toner images have been transferred in multiple layers through each unit reaches a secondary transfer section that is composed of the intermediate transfer belt 20, an opposing roll 24 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer means) 26 arranged on the image bearing surface side of the intermediate transfer belt 20. 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 26 and the intermediate transfer belt 20 via a supply mechanism, and a secondary transfer bias is applied to the opposing roll 24. 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 20 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 20 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 means (not shown) that detects the resistance of the secondary transfer section, and is voltage-controlled.

[0138] After the toner image is transferred to the recording paper P, the intermediate transfer belt 20 continues to run and comes into contact with a cleaning blade provided in the intermediate transfer body cleaning device 21. The toner remaining on the intermediate transfer belt 20 is removed and collected by the intermediate transfer body cleaning device 21.

[0139] The recording paper P to which the toner image has been transferred is fed into the pressure contact portion (nip portion) of a pair of fixing rolls in a fixing device (one example of a fixing means) 28, where the toner image is fixed onto the recording paper P to form a fixed image.

[0140] 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.

[0141] 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.

[0142] <Process cartridge / toner cartridge set> The process cartridge according to the present disclosure will be described. The process cartridge according to the present disclosure is a process cartridge which is detachably attached to an image forming apparatus and which includes a yellow developing means, a magenta developing means, a cyan developing means, and a black developing means each separately containing the yellow developer, the magenta developer, the cyan developer, and the black developer of the electrostatic image developer set according to the present disclosure, a first developing means containing the first developer of the electrostatic image developer set according to the present disclosure, and a second developing means containing the second developer of the electrostatic image developer set according to the present disclosure.

[0143] In addition, the process cartridge according to the present disclosure is not limited to the above configuration, and may be configured to include a developing device and, as necessary, at least one other means selected from an image carrier, a charging means, an electrostatic image forming means, and a transfer means.

[0144] An example of a process cartridge according to the present disclosure will be described below, but the present disclosure is not limited to this example. Note that only the main parts shown in the drawings will be described, and descriptions of the rest will be omitted.

[0145] FIG. 2 is a schematic configuration diagram showing the process cartridge according to the present disclosure. The process cartridge 200 shown in FIG. 2 is configured by, for example, a housing 117 having a mounting rail 116 and an opening 118 for exposure, and integrally combining and holding a photoconductor 107 (an example of an image carrier), a charging roll 108 (an example of a charging means) provided around the photoconductor 107, a developing device 111 (an example of a developing means), and a photoconductor cleaning device 113 (an example of a cleaning means), which are assembled into a cartridge. In FIG. 2, 109 denotes an exposure device (an example of an electrostatic image forming means), 112 denotes a transfer device (an example of a transfer means), 115 denotes a fixing device (an example of a fixing means), and 300 denotes a recording paper (an example of a recording medium).

[0146] Next, a toner cartridge set according to the present disclosure will be described. The toner cartridge set according to the present disclosure includes a yellow toner cartridge, a magenta toner cartridge, a cyan toner cartridge, and a black toner cartridge each separately containing the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set according to the present disclosure, a first toner cartridge containing the first toner of the toner set according to the present disclosure, and a second toner cartridge containing the second toner of the toner set according to the present disclosure, and is a toner cartridge set that is detachable from an image forming device. Each toner cartridge contains replenishment toner to be supplied to each developing means provided in the image forming apparatus.

[0147] The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8G, 8P, 8Y, 8M, 8C, and 8K are detachably attached, and the developing devices 4G, 4P, 4Y, 4M, 4C, and 4K are connected to toner cartridges corresponding to the respective colors by toner supply pipes (not shown). When the toner contained in the toner cartridge runs low, the toner cartridge is replaced. An example of a toner cartridge set according to the present disclosure is the toner cartridges 8G, 8P, 8Y, 8M, 8C, and 8K, which contain the toner set according to the present disclosure. The toner cartridges 8G, 8P, 8Y, 8M, 8C, and 8K contain fluorescent green, fluorescent pink, yellow, magenta, cyan, and black toners, respectively. EXAMPLES

[0148] Hereinafter, the embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are by mass. Synthesis, processing, preparation, etc. were carried out at room temperature (25°C ± 3°C) unless otherwise noted.

[0149] [Production of fluorescent green toner 1 and developer 1] <Synthesis of crystalline resin particle dispersion (1)> 1,10-dodecanedioic acid: 50 mol% 1,9-nonanediol: 50 mol% The monomer components were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube, and the inside of the reaction vessel was replaced with dry nitrogen gas, after which 0.25 parts of titanium tetrabutoxide (reagent) was added per 100 parts of the monomer components. After stirring and reacting for 3 hours at 170°C under a nitrogen gas stream, the temperature was further raised to 210°C over 1 hour, the pressure inside the reaction vessel was reduced to 3 kPa, and stirring and reacting for 13 hours under reduced pressure was performed to obtain a crystalline polyester resin (1). The resulting crystalline polyester resin (1) had a melting temperature of 73.6° C. as measured by DSC, a mass average molecular weight Mw of 25,000, a number average molecular weight Mn of 10,500, and an acid value AV of 10.1 mgKOH / g as measured by GPC.

[0150] 300 parts of the crystalline polyester resin (1), 160 parts of methyl ethyl ketone (solvent), and 100 parts of isopropyl alcohol (solvent) were placed in a jacketed reaction vessel (BJ-30N, manufactured by Tokyo Rikakikai Co., Ltd.) equipped with a condenser, a thermometer, a water dropping device, and an anchor blade, and the resin was dissolved by stirring and mixing at 100 rpm while maintaining the temperature at 70° C. in a water circulation type thermostatic bath. Thereafter, the stirring speed was changed to 150 rpm, the water circulation type thermostatic bath was set to 66°C, and 17 parts of 10% by mass ammonia water (reagent) was added over 10 minutes, after which a total of 900 parts of ion-exchanged water kept at 66°C was dropped at a rate of 7 parts / min to cause phase inversion and obtain an emulsion. Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were placed in an eggplant flask and set in an evaporator (Tokyo Rikakikai Co., Ltd.) equipped with a vacuum control unit via a trap bulb. The eggplant flask was rotated and heated in a hot water bath at 60°C, and the pressure was reduced to 7 kPa while taking care not to bump, to remove the solvent. When the amount of recovered solvent reached 1,100 parts, the pressure was returned to normal, and the eggplant flask was cooled with water to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle size of the resin particles in this dispersion was 130 nm. Ion-exchanged water was then added to adjust the solid content concentration to 20 mass%, to obtain crystalline resin particle dispersion (1).

[0151] <Preparation of amorphous resin particle dispersion (1)> Terephthalic acid: 30 parts by mole Fumaric acid: 70 parts by mole Bisphenol A ethylene oxide adduct: 5 mole parts Bisphenol A propylene oxide adduct: 95 parts by mole The above materials were charged into a flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a distillation column, and the temperature was raised to 220°C over 1 hour, and 1 part of titanium tetraethoxide was added for 100 parts of the above materials. The temperature was raised to 230°C over 30 minutes while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, after which the reactant was cooled. In this way, an amorphous polyester resin (1) with a weight average molecular weight of 18,000 and a glass transition temperature of 60°C was obtained.

[0152] In a vessel equipped with a temperature control means and a nitrogen substitution means, 40 parts of ethyl acetate and 25 parts of 2-butanol were added to prepare a mixed solvent, and then 100 parts of amorphous polyester resin (1) were gradually added and dissolved, and a 10% by mass aqueous ammonia solution (equivalent to 3 times the amount by molar ratio relative to the acid value of the resin) was added thereto and stirred for 30 minutes. Next, the inside of the vessel was substituted with dry nitrogen, the temperature was kept at 40°C, and 400 parts of ion-exchanged water was dropped at a rate of 2 parts / min while stirring the mixed liquid. After the dropping was completed, the temperature was returned to room temperature (20°C to 25°C), and bubbling with dry nitrogen was performed for 48 hours while stirring to obtain a resin particle dispersion in which ethyl acetate and 2-butanol were reduced to 1,000 ppm or less. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% by mass, and an amorphous resin particle dispersion (1) was obtained.

[0153] <Preparation of Colorant Particle Dispersion (1)> Fluorescent dye Solvent Green 5 (CI Solvent Green 5 (BASF Oracet F Yellow 084, emission peak 520 nm): 2 parts Amorphous polyester resin (weight average molecular weight 13,000, glass transition temperature 62°C): 100 parts The above materials were heated and mixed, and the dye was kneaded into the resin. The kneaded product was rolled and cooled to 30°C or less. The kneaded product obtained was coarsely pulverized to 1 mm or less using a hammer mill, and then finely pulverized using a jet mill (AFG, Hosokawa Micron Corporation). The finely pulverized particles were mixed with 30 parts (20% solid content) of anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts of ion-exchanged water, and pulverized to a volume average particle size of 200 nm using a continuous key mill (KMC-3, Inoue Seisaku Co., Ltd.). The solid content was adjusted to 20% by mass, and a colorant particle dispersion (1) was obtained.

[0154] <Preparation of Colorant Particle Dispersion (2)> Non-fluorescent pigment PG36 (CI Pigment Green 36 (TOYO COLOR Co., Ltd., LIONOL GREEN 8624), volume average particle size: 120 nm): 70 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts (solid content concentration 20%) - Ion-exchanged water: 200 parts The above components were mixed and pulverized to 95 nm using a continuous key mill (KMC-3), and the solid content was adjusted to 20% by mass to obtain colorant particle dispersion (2).

[0155] <Preparation of Release Agent Particle Dispersion (1)> Microcrystalline wax (Nihon Seiro Co., Ltd., HiMic-1090, melting temperature: 87°C): 100 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water: 350 parts The above materials were mixed and heated to 100°C, dispersed using a homogenizer (IKA, product name Ultra Turrax T50), and then dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin), to obtain a release agent particle dispersion (1) (solid content 20% by mass) in which release agent particles having a volume average particle size of 200 nm were dispersed.

[0156] <Preparation of fluorescent green toner particles (1)> ·Crystalline resin particle dispersion (1): 35 parts ·Amorphous resin particle dispersion (1): 100 parts Colorant particle dispersion (1): 125 parts Colorant particle dispersion (2): 17 parts Release agent particle dispersion (1): 40 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts The above materials were placed in a round stainless steel flask, and 0.1N (=mol / L) nitric acid was added to adjust the pH to 3.5, and then 30 parts of a nitric acid aqueous solution with a polyaluminum chloride concentration of 10% by mass was added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA, product name Ultra Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. Then, 100 parts of amorphous resin particle dispersion (1) was added and held for 1 hour, and 0.1N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, and the solid content was filtered, thoroughly washed with ion-exchanged water, and dried to obtain fluorescent green toner particles (1). The volume average particle size of the fluorescent green toner particles (1) was 5.8 μm, and the content of granular matter relative to the entire fluorescent green toner particles (1) was 4% by mass.

[0157] <Toner Production> 100 parts by mass of the obtained fluorescent green toner particles (1) were mixed and blended with 1.5 parts by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part by mass of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. The mixture was then sieved using a vibrating sieve with an opening of 45 μm to prepare fluorescent green toner 1. The volume average particle size of the obtained fluorescent green toner 1 was 5.8 μm.

[0158] <Preparation of Carrier 1> Ferrite particles (average particle size 35 μm): 100 parts Toluene: 14 parts Polymethyl methacrylate (MMA, weight average molecular weight 75,000): 5 parts Carbon black: 0.2 parts (VXC-72, manufactured by Cabot Corporation, volume resistivity: 100 Ω cm or less) The above materials except for the ferrite particles were dispersed in a sand mill to prepare a dispersion liquid, and this dispersion liquid was placed in a vacuum degassing kneader together with the ferrite particles, and the mixture was dried under reduced pressure while stirring to obtain a carrier 1.

[0159] <Preparation of electrostatic image developer> 1:8 parts of fluorescent green toner and 1:92 parts of carrier were mixed in a V blender to prepare developer 1 (electrostatic image developer).

[0160] [Production of fluorescent green toner 2 and developer 2] <Preparation of release agent particle dispersion (2)> Polyethylene wax (manufactured by Nippon Seiro Co., Ltd., ACCULIN 600, melting temperature: 94°C): 100 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water: 350 parts The above materials were mixed and heated to 100°C, dispersed using a homogenizer (IKA Corporation, trade name Ultra Turrax T50), and then dispersed using a Manton-Gaulin high pressure homogenizer (Gaulin Corporation) to obtain a release agent particle dispersion (2) (solid content 20% by mass) in which release agent particles having a volume average particle size of 200 nm were dispersed.

[0161] <Preparation of fluorescent green toner particles (2)> Fluorescent green toner particles (2) were obtained in the same manner as fluorescent green toner particles (1), except that release agent particle dispersion liquid (1) was changed to release agent particle dispersion liquid (2). The volume average particle size of the fluorescent green toner particles (2) was 5.9 μm, and the content of particulate matter relative to the entire fluorescent green toner particles (2) was 4 mass%.

[0162] <Preparation of toner and developer> Fluorescent green toner 2 and developer 2 were obtained in the same manner as fluorescent green toner 1 and developer 1, except that fluorescent green toner particles (2) were used instead of fluorescent green toner particles (1).

[0163] [Production of Fluorescent Green Toner 3 and Developer 3] <Preparation of release agent particle dispersion (3)> Microcrystalline wax (Nihon Seiro Co., Ltd., HiMic-1090, melting temperature: 80°C): 100 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water: 350 parts The above materials were mixed and heated to 100° C., dispersed using a homogenizer (IKA Corporation, product name Ultra Turrax T50), and then dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin Corporation) to obtain a release agent particle dispersion (3) (solid content 20% by mass) in which release agent particles having a volume average particle size of 200 nm were dispersed.

[0164] <Preparation of fluorescent green toner particles (3)> Fluorescent green toner particles (3) were obtained in the same manner as fluorescent green toner particles (1), except that release agent particle dispersion liquid (1) was changed to release agent particle dispersion liquid (3). The fluorescent green toner particles (3) had a volume average particle size of 5.9 μm, and the content of particulate matter relative to the entire fluorescent green toner particles (3) was 4 mass%.

[0165] <Preparation of toner and developer> Fluorescent green toner 3 and developer 3 were obtained in the same manner as fluorescent green toner 1 and developer 1, except that fluorescent green toner particles (3) were used instead of fluorescent green toner particles (1).

[0166] [Production of Fluorescent Green Toner 4 and Developer 4] <Preparation of Colorant Particle Dispersion (3)> Fluorescent dye Solvent Green 3 (CI Solvent Green 3 (BASF OPLAS GREEN 533): 2 parts Amorphous polyester resin (weight average molecular weight 13,000, glass transition temperature 62°C): 100 parts The above materials were heated and mixed, and the dye was kneaded into the resin. The kneaded product was rolled and cooled to 30°C or less. The kneaded product obtained was coarsely pulverized to 1 mm or less using a hammer mill, and then finely pulverized using a jet mill (AFG, Hosokawa Micron Corporation). The finely pulverized particles were mixed with 30 parts (20% solid content) of anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts of ion-exchanged water, and pulverized to a volume average particle size of 200 nm using a continuous key mill (KMC-3, Inoue Seisaku Co., Ltd.). The solid content was adjusted to 20% by mass, and a colorant particle dispersion (3) was obtained.

[0167] <Preparation of fluorescent green toner particles (4)> ·Crystalline resin particle dispersion (1): 35 parts ·Amorphous resin particle dispersion (1): 100 parts Colorant particle dispersion (1): 100 parts Colorant particle dispersion (3): 42 parts Release agent particle dispersion (1): 40 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts The above materials were placed in a round stainless steel flask, and 0.1N (=mol / L) nitric acid was added to adjust the pH to 3.5, and then 30 parts of a nitric acid aqueous solution with a polyaluminum chloride concentration of 10% by mass was added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA, product name Ultra Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. Then, 100 parts of amorphous resin particle dispersion (1) was added and held for 1 hour, and 0.1N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, and the solid content was filtered, thoroughly washed with ion-exchanged water, and dried to obtain fluorescent green toner particles (4). The volume average particle size of the fluorescent green toner particles (4) was 5.7 μm, and the content of granular matter relative to the entire fluorescent green toner particles (4) was 0% by mass.

[0168] <Preparation of toner and developer> Fluorescent green toner 4 and developer 4 were obtained in the same manner as fluorescent green toner 1 and developer 1, except that fluorescent green toner particles (4) were used instead of fluorescent green toner particles (1).

[0169] [Manufacture of Fluorescent Pink Toner 5 and Developer 5] <Preparation of Colorant Particle Dispersion (4)> Fluorescent dye Basic Red 1:1 (CI Basic Red 1:1 (BASF Basonyl Red 485): 2 parts Amorphous polyester resin (weight average molecular weight 13,000, glass transition temperature 62°C): 100 parts The above materials were heated and mixed, and the dye was kneaded into the resin. The kneaded product was rolled and cooled to 30°C or less. The kneaded product obtained was coarsely pulverized to 1 mm or less using a hammer mill, and then finely pulverized using a jet mill (AFG, Hosokawa Micron Corporation). The finely pulverized particles were mixed with 30 parts (20% solid content) of anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts of ion-exchanged water, and pulverized to a volume average particle size of 200 nm using a continuous key mill (KMC-3, Inoue Seisaku Co., Ltd.). The solid content was adjusted to 20% by mass, and a colorant particle dispersion (4) was obtained.

[0170] <Preparation of Colorant Particle Dispersion (5)> Fluorescent dye Basic Violet 11:1 (CI Basic Violet 11:1 (NEELIKON Neeliglow Basic Violet 11:1): 2 parts Amorphous polyester resin (weight average molecular weight 13,000, glass transition temperature 62°C): 100 parts The above materials were heated and mixed, and the dye was kneaded into the resin. The kneaded product was rolled and cooled to 30°C or less. The kneaded product obtained was coarsely pulverized to 1 mm or less using a hammer mill, and then finely pulverized using a jet mill (AFG, Hosokawa Micron Corporation). The finely pulverized particles were mixed with 30 parts (20% solid content) of anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts of ion-exchanged water, and pulverized to a volume average particle size of 200 nm using a continuous key mill (KMC-3, Inoue Seisaku Co., Ltd.). The solid content was adjusted to 20% by mass, and a colorant particle dispersion (5) was obtained.

[0171] <Preparation of fluorescent pink toner particles (5)> ·Crystalline resin particle dispersion (1): 35 parts ·Amorphous resin particle dispersion (1): 100 parts Colorant particle dispersion (4): 71 parts Colorant particle dispersion (5): 71 parts Release agent particle dispersion (1): 40 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts The above materials were placed in a round stainless steel flask, and 0.1N (=mol / L) nitric acid was added to adjust the pH to 3.5, and then 30 parts of a nitric acid aqueous solution with a polyaluminum chloride concentration of 10% by mass was added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA, product name Ultra Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. Then, 100 parts of amorphous resin particle dispersion (1) was added and held for 1 hour, and 0.1N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, and the solid content was filtered, thoroughly washed with ion-exchanged water, and dried to obtain fluorescent pink toner particles (5). The volume average particle size of the fluorescent pink toner particles (5) was 5.7 μm, and the content of granular matter relative to the entire fluorescent pink toner particles (5) was 0% by mass.

[0172] <Preparation of toner and developer> Fluorescent pink toner 5 and developer 5 were obtained in the same manner as fluorescent green toner 1 and developer 1, except that fluorescent pink toner particles (5) were used instead of fluorescent green toner particles (1).

[0173] [Production of Fluorescent Pink Toner 6 and Developer 6] <Synthesis of crystalline resin particle dispersion (2)> 1,10-dodecanedioic acid: 50 mol% 1,2-nonanediol: 50 mol% The monomer components were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube, and the inside of the reaction vessel was replaced with dry nitrogen gas, after which 0.25 parts of titanium tetrabutoxide (reagent) was added per 100 parts of the monomer components. After stirring and reacting for 3 hours at 170°C under a nitrogen gas stream, the temperature was further raised to 210°C over 1 hour, the pressure inside the reaction vessel was reduced to 3 kPa, and stirring and reacting were continued under reduced pressure for 13 hours to obtain a crystalline polyester resin (2). The resulting crystalline polyester resin (2) had a melting temperature of 85.3° C. as measured by DSC, a mass average molecular weight Mw of 24,000, a number average molecular weight Mn of 10,800, and an acid value AV of 11.1 mgKOH / g as measured by GPC.

[0174] 300 parts of the crystalline polyester resin (1), 160 parts of methyl ethyl ketone (solvent), and 100 parts of isopropyl alcohol (solvent) were placed in a jacketed reaction vessel (BJ-30N, manufactured by Tokyo Rikakikai Co., Ltd.) equipped with a condenser, a thermometer, a water dropping device, and an anchor blade, and the resin was dissolved by stirring and mixing at 100 rpm while maintaining the temperature at 70° C. in a water circulation type thermostatic bath. Thereafter, the stirring speed was changed to 150 rpm, the water circulation type thermostatic bath was set to 66°C, and 17 parts of 10% by mass ammonia water (reagent) was added over 10 minutes, after which a total of 900 parts of ion-exchanged water kept at 66°C was dropped at a rate of 7 parts / min to cause phase inversion and obtain an emulsion. Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were placed in an eggplant flask and set in an evaporator (Tokyo Rikakikai Co., Ltd.) equipped with a vacuum control unit via a trap bulb. The eggplant flask was rotated and heated in a hot water bath at 60°C, and the pressure was reduced to 7 kPa while taking care not to bump, to remove the solvent. When the amount of recovered solvent reached 1,100 parts, the pressure was returned to normal, and the eggplant flask was cooled with water to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle size of the resin particles in this dispersion was 130 nm. Ion-exchanged water was then added to adjust the solid concentration to 20 mass%, to obtain crystalline resin particle dispersion (2).

[0175] <Preparation of fluorescent pink toner particles (6)> Fluorescent pink toner particles (6) were obtained in the same manner as fluorescent pink toner particles (5), except that crystalline resin particle dispersion liquid (1) was changed to crystalline resin particle dispersion liquid (2). The fluorescent pink toner particles (6) had a volume average particle size of 5.9 μm, and the particulate matter content relative to the entire fluorescent pink toner particles (6) was 0 mass%.

[0176] <Preparation of toner and developer> Fluorescent pink toner 6 and developer 6 were obtained in the same manner as fluorescent pink toner 5 and developer 5, except that fluorescent pink toner particles (6) were used instead of fluorescent pink toner particles (5).

[0177] [Manufacture of Fluorescent Pink Toner 7 and Developer 7] <Preparation of Release Agent Particle Dispersion (4)> Paraffin wax (Nippon Seiro Co., Ltd., Parafin Wax-140, melting temperature: 61°C): 100 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water: 350 parts The above materials were mixed and heated to 100° C., dispersed using a homogenizer (IKA Corporation, trade name Ultra Turrax T50), and then dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin Corporation) to obtain a release agent particle dispersion (4) (solid content 20% by mass) in which release agent particles having a volume average particle size of 200 nm were dispersed.

[0178] <Preparation of fluorescent pink toner particles (7)> Fluorescent pink toner particles (7) were obtained in the same manner as fluorescent pink toner particles (5), except that release agent particle dispersion liquid (1) was changed to release agent particle dispersion liquid (4). The fluorescent pink toner particles (7) had a volume average particle size of 5.8 μm, and the particulate matter content relative to the entire fluorescent pink toner particles (7) was 0 mass%.

[0179] <Preparation of toner and developer> Fluorescent pink toner 7 and developer 7 were obtained in the same manner as fluorescent pink toner 5 and developer 5, except that fluorescent pink toner particles (7) were used instead of fluorescent pink toner particles (5).

[0180] [Production of Fluorescent Pink Toner 8 and Developer 8] <Preparation of Colorant Particle Dispersion (6)> Non-fluorescent pigment PR122 (CI Pigment Red 122 (DIC FASTOGEN SUPER MAGENTA R), volume average particle size: 100 nm): 70 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts - Ion-exchanged water: 200 parts The above components were mixed and pulverized to 90 nm using a continuous key mill (KMC-3), and the solid content was adjusted to 20% by mass, to obtain a colorant particle dispersion (6).

[0181] <Preparation of fluorescent pink toner particles (8)> ·Crystalline resin particle dispersion (1): 35 parts ·Amorphous resin particle dispersion (1): 100 parts Colorant particle dispersion (4): 125 parts Colorant particle dispersion (6): 17 parts Release agent particle dispersion (1): 40 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts The above materials were placed in a round stainless steel flask, and 0.1N (=mol / L) nitric acid was added to adjust the pH to 3.5, and then 30 parts of a nitric acid aqueous solution with a polyaluminum chloride concentration of 10% by mass was added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA, product name Ultra Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. Then, 100 parts of amorphous resin particle dispersion (1) was added and held for 1 hour, and 0.1N sodium hydroxide aqueous solution was added to adjust the pH to 8.5, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, and the solid content was filtered, thoroughly washed with ion-exchanged water, and dried to obtain fluorescent pink toner particles (8). The volume average particle size of the fluorescent pink toner particles (8) was 5.7 μm, and the content of granular matter relative to the entire fluorescent pink toner particles (8) was 4% by mass.

[0182] <Preparation of toner and developer> Fluorescent pink toner 8 and developer 8 were obtained in the same manner as fluorescent pink toner 5 and developer 5, except that fluorescent pink toner particles (8) were used instead of fluorescent pink toner particles (5).

[0183] [Production of Transparent Toner 9 and Developer 9] <Preparation of inorganic particle dispersion (1)> Silica particles (Shin-Etsu Silicone, product name: X-24-9404, volume average particle size: 50 nm): 70 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts - Ion-exchanged water: 200 parts The above materials were mixed and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50 manufactured by IKA Corporation). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass, and an inorganic particle dispersion (1) having a volume average particle size of 50 nm was obtained.

[0184] <Preparation of transparent toner particles (9)> ·Crystalline resin particle dispersion (1): 35 parts ·Amorphous resin particle dispersion (1): 225 parts ·Inorganic particle dispersion (1): 17 parts Release agent particle dispersion (1): 40 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts The above materials were placed in a round stainless steel flask, and 0.1N (=mol / L) nitric acid was added to adjust the pH to 3.5, and then 30 parts of a nitric acid aqueous solution with a polyaluminum chloride concentration of 10% by mass was added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA, product name Ultra Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. Then, 100 parts of amorphous resin particle dispersion (1) was added and held for 1 hour, and 0.1N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, and the solid content was filtered, thoroughly washed with ion-exchanged water, and dried to obtain transparent toner particles (9). The volume average particle size of the transparent toner particles (9) was 5.7 μm, and the content of granular matter relative to the entire transparent toner particles (9) was 4% by mass.

[0185] <Preparation of toner and developer> Transparent toner 9 and developer 9 were obtained in the same manner as fluorescent green toner 1 and developer 1, except that transparent toner particles (9) were used instead of fluorescent green toner particles (1).

[0186] [Production of transparent toner 10 and developer 10] Transparent toner particles (10) were obtained in the same manner as transparent toner particles (9), except that inorganic particle dispersion liquid (1) was not used. The volume average particle size of transparent toner particles (10) was 5.8 μm, and the content of particulate matter relative to the total amount of transparent toner particles (10) was 0% by mass. Transparent toner 10 and developer 10 were obtained in the same manner as transparent toner 9 and developer 9, except that transparent toner particles (10) were used instead of transparent toner particles (9).

[0187] [Examples 1 to 8, Comparative Examples 1 and 2] The toner and developer obtained as described above were combined as shown in Table 1 to obtain a toner set. As the YMCK toners, commercially available toners of each color were used. Table 1 also shows the crystallization temperature T1, crystallization temperature T2, crystallization temperature T3, the difference between crystallization temperature T1 and crystallization temperature T2 ("T1-T2 (°C)" in the table), the difference between crystallization temperature T1 and crystallization temperature T3 ("|T3-T1| (°C)" in the table), and the difference between crystallization temperature T2 and crystallization temperature T3 ("|T3-T2| (°C)" in the table), all determined for each toner using the method described above.

[0188] [evaluation] <Image forming device> 1, developer A shown in Table 1 was supplied to developing device 4G of first image forming unit 10G, developer B shown in Table 1 was supplied to developing device 4P of second image forming unit 10P, and YMCK developers were supplied to developing device 4Y of yellow image forming unit 10Y, developing device 4M of magenta image forming unit 10M, developing device 4C of cyan image forming unit 10C, and developing device 4K of black image forming unit 10K, respectively. The image forming apparatus was modified so that the fixing temperature of fixing device 28 could be changed, and images were formed. The process speed was 534 mm / sec.

[0189] <Hot offset evaluation> The recording medium is thin wood-free paper (npi wood-free paper, 52 g / m 2 A 50mm x 50mm unfixed image was created by stacking six solid colors with a density of 100% on a paper sheet made by Nippon Seishi Co., Ltd., with a toner loading of 20g / m2 in total. 2 The composition was adjusted so that the thickness was 100 nm. The fixing temperature was varied from 170°C to 230°C, and the unfixed images were fixed at 5°C intervals. The presence or absence of hot offset was visually confirmed, and the lowest temperature at which hot offset occurred was regarded as the hot offset occurrence temperature for evaluation. The evaluation criteria were as follows. The results are shown in Table 1. A: Hot offset occurs at a temperature of 230°C or higher. B: The hot offset occurrence temperature is 210°C or higher and less than 230°C. C: Hot offset occurs at a temperature of 190°C or higher and less than 210°C. D: Hot offset occurrence temperature is less than 190°C.

[0190] <Cold offset evaluation> Recording medium: thick coated paper (Aurora coated paper, 209 g / m 2 A 50mm x 50mm unfixed image was created by stacking six solid colors with a density of 100% on a paper sheet made by Nippon Seishi Co., Ltd., with a toner loading of 20g / m2 in total. 2 The composition was adjusted so that the thickness was 100 nm. The fixing temperature was changed from 150°C to 200°C, and the unfixed images were fixed at 5°C intervals. The presence or absence of cold offset was confirmed by visual inspection, and the lowest temperature at which cold offset occurred was regarded as the cold offset occurrence temperature and evaluated. The evaluation criteria were as follows. The results are shown in Table 1. A: The temperature at which cold offset occurs is 150℃ or less. B: The temperature at which cold offset occurs is greater than 150°C and less than 160°C. C: The temperature at which cold offset occurs is greater than 160°C and less than 170°C. D: The temperature at which cold offset occurs is 180°C or lower.

[0191] [Table 1]

[0192] From the results shown in Table 1, it is evident that the toner set of this embodiment realizes both suppression of hot offset and suppression of cold offset.

[0193] Preferred aspects of the present disclosure are described below. (((1))) a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment; a first toner which is a dye toner or a transparent toner and has a crystallization temperature T1 of 80° C. or more and 95° C. or less; a second toner which is a dye toner or a transparent toner and has a crystallization temperature T2 of 60° C. or more and 75° C. or less; A toner set for developing electrostatic images comprising: (((2))) The toner set for developing electrostatic images according to (((1))), wherein the difference between the crystallization temperature T1 and the crystallization temperature T2 is 15° C. or more. (((3))) The toner set for developing electrostatic images according to (((2))), wherein the difference between the crystallization temperature T1 and the crystallization temperature T2 is 20° C. or more. (((4))) When the average of the crystallization temperatures of the yellow toner, the magenta toner, the cyan toner, and the black toner is defined as a crystallization temperature T3, The toner set for developing electrostatic images according to any one of (((1))) to (((3))), wherein a difference between the crystallization temperature T1 and the crystallization temperature T3 is 5° C. or less, and a difference between the crystallization temperature T2 and the crystallization temperature T3 is 20° C. or more. (((5))) the first toner comprises first toner particles containing a crystalline resin and a particulate material; The second toner includes second toner particles containing a crystalline resin. The toner set for developing electrostatic images according to any one of (((1))) to (((4))). (((6))) The toner set for developing electrostatic images according to (((5))), wherein the particulate matter is colorless and transparent. (((7))) The toner set for developing electrostatic images according to (((5))) or (((6))), wherein the particulate matter is silica particles. (((8))) The toner set for developing electrostatic images according to any one of (((5))) to (((7))), wherein the content of the particulate matter contained in the first toner is 1% by mass or more and 5% by mass or less.

[0194] (((9))) a yellow developer, a magenta developer, a cyan developer, and a black developer each containing the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); A first developer containing the first toner of the toner set for developing electrostatic images according to any one of (((1))) to (((8))); A second developer containing the second toner of the toner set for developing electrostatic images according to any one of (((1))) to (((8))); Electrostatic image developer set comprising: (((10))) a yellow toner cartridge, a magenta toner cartridge, a cyan toner cartridge, and a black toner cartridge each containing the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); a first toner cartridge including the first toner in the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); a second toner cartridge including the second toner in the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); having A toner cartridge set that is detachably attached to an image forming apparatus. (((11))) A yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit each containing the yellow developer, the magenta developer, the cyan developer, and the black developer separately, from the electrostatic image developer set according to (((9))); A first developing means including the first developer of the electrostatic image developer set according to (((9))), A second developing means including the second developer of the electrostatic image developer set according to (((9))), Equipped with A process cartridge that is detachably attached to an image forming apparatus. (((12))) a yellow image forming means, a magenta image forming means, a cyan image forming means, and a black image forming means for forming a yellow image, a magenta image, a cyan image, and a black image, respectively, using the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); A first image forming means for forming a first image using the first toner of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); A second image forming means for forming a second image by the second toner of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); a transfer means for transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing unit that fixes a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming apparatus comprising: (((13))) The image forming apparatus described in (((12))), wherein the layer of the toner image farthest from the recording medium is the first image, and the layer of the toner image second farthest from the recording medium is the second image. (((14))) a yellow image forming step, a magenta image forming step, a cyan image forming step, and a black image forming step, in which a yellow image, a magenta image, a cyan image, and a black image are formed using the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set for developing an electrostatic image according to any one of (((1))) to (((8))); a first image forming step of forming a first image using the first toner of the toner set for developing electrostatic images according to any one of (((1))) to (((8))); A second image forming step of forming a second image using the second toner of the toner set for developing electrostatic images according to any one of (((1))) to (((8))); a transfer step of transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing step of fixing a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming method comprising: (((15))) The image forming method described in (((14))), wherein the layer of the toner image farthest from the recording medium is the first image, and the layer of the toner image second farthest from the recording medium is the second image.

[0195] According to the invention related to (((1))), (((5))), (((6))), or (((7))), there is provided a toner set for developing electrostatic images which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner, or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which, compared to a case in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C, suppresses a phenomenon in which the toner melts excessively when a toner image is fixed and adheres to the fixing member (hereinafter also referred to as "hot offset"), and suppresses a phenomenon in which the toner that is not sufficiently melted when a toner image is fixed is transferred to the fixing member due to an insufficient amount of heat supplied to the toner (hereinafter also referred to as "cold offset"). According to the invention related to (((2))), there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, compared to a case in which the difference between the crystallization temperature T1 and the crystallization temperature T2 is less than 15°C. According to the invention related to (((3))), there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, compared to a case in which the difference between the crystallization temperature T1 and the crystallization temperature T2 is less than 20°C. According to the invention related to (((4))), there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, compared to when the difference between the crystallization temperature T1 and the crystallization temperature T3 is less than 5°C or the difference between the crystallization temperature T2 and the crystallization temperature T3 is less than 20°C. According to the invention related to (((8))), there is provided a toner set for developing electrostatic images which suppresses both hot offset and cold offset, compared to when the particulate content in the first toner is less than 1% by mass or exceeds 5% by mass.

[0196] According to the invention related to (((9))), (((10))), (((11))), (((12))), or (((14))), there is provided an electrostatic image developer set, a toner cartridge set, a process cartridge, an image forming apparatus, or an image forming method which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner, or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which achieves both suppression of hot offset and suppression of cold offset compared to the application of a toner set for developing electrostatic images in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C. According to the invention pertaining to (((13))) or (((15))), even if the layer farthest from the recording medium is a first image and the layer second farthest from the recording medium is a second image, an image forming apparatus or image forming method is provided which includes a first toner which is a yellow toner, a magenta toner, a cyan toner, a black toner, a dye toner or a transparent toner, and a second toner which is a dye toner or a transparent toner, and which achieves both suppression of hot offset and suppression of cold offset compared to the application of a toner set for developing electrostatic images in which the crystallization temperature T1 of the first toner is less than 80°C or the crystallization temperature T2 of the second toner is more than 75°C. [Explanation of symbols]

[0197] 1G, 1P, 1Y, 1M, 1C, 1K Photoconductor (an example of an image carrier) 2G, 2P, 2Y, 2M, 2C, 2K Charging roll (an example of charging means) 3G, 3P, 3Y, 3M, 3C, 3K exposure equipment (an example of electrostatic image forming means) 4G, 4P, 4Y, 4M, 4C, 4K developing device (an example of developing means) 5G, 5P, 5Y, 5M, 5C, 5K Primary transfer roll (an example of a primary transfer means) 6G, 6P, 6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of a cleaning means) 8G, 8P, 8Y, 8M, 8C, 8K toner cartridges 10G, 10P, 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer body) 21 Intermediate transfer body cleaning device 22 Driving Roll 23 Support roll 24 Opposing Roll 26 Secondary transfer roll (an example of a secondary transfer means) 28 Fixing device (an example of a fixing means) P Recording paper (an example of a recording medium)

[0198] 107 Photoconductor (an example of an image carrier) 108 Charging roll (an example of charging means) 109 Exposure device (an example of electrostatic image forming means) 111 Developing device (an example of developing means) 112 Transfer device (an example of a transfer means) 113 Photoconductor cleaning device (an example of a cleaning means) 115 Fixing device (an example of fixing means) 116 Mounting Rail 117 Cabinet 118 Exposure Aperture 200 Process Cartridge 300 Recording paper (an example of a recording medium)

Claims

1. a yellow toner containing a yellow pigment, a magenta toner containing a magenta pigment, a cyan toner containing a cyan pigment, and a black toner containing a black pigment; a first toner which is a dye toner or a transparent toner and has a crystallization temperature T1 of 80° C. or more and 95° C. or less; a second toner which is a dye toner or a transparent toner and has a crystallization temperature T2 of 60° C. or more and 75° C. or less; A toner set for developing electrostatic images comprising:

2. 2. The toner set for developing electrostatic images according to claim 1, wherein the difference between the crystallization temperature T1 and the crystallization temperature T2 is 15[deg.] C. or more.

3. 3. The toner set for developing electrostatic images according to claim 2, wherein the difference between the crystallization temperature T1 and the crystallization temperature T2 is 20[deg.] C. or more.

4. When the average value of the crystallization temperatures of the yellow toner, the magenta toner, the cyan toner, and the black toner is defined as a crystallization temperature T3, 2. The toner set for developing electrostatic images according to claim 1, wherein the difference between said crystallization temperature T1 and said crystallization temperature T3 is 5° C. or less, and the difference between said crystallization temperature T2 and said crystallization temperature T3 is 20° C. or more.

5. the first toner includes first toner particles containing a crystalline resin and particulate matter; the second toner includes second toner particles containing a crystalline resin; The toner set for developing electrostatic images according to claim 1 .

6. 6. The toner set for developing electrostatic images according to claim 5, wherein said particulate matter is colorless and transparent.

7. 6. The toner set for developing electrostatic images according to claim 5, wherein said particulate matter is silica particles.

8. 6. The toner set for developing electrostatic images according to claim 5, wherein the content of the particulate matter contained in the first toner is from 1% by mass to 5% by mass.

9. a yellow developer, a magenta developer, a cyan developer, and a black developer each containing the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8 separately; A first developer including the first toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; A second developer containing the second toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; Electrostatic image developer set comprising:

10. a yellow toner cartridge, a magenta toner cartridge, a cyan toner cartridge, and a black toner cartridge each including the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; A first toner cartridge including the first toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; a second toner cartridge including the second toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; having A toner cartridge set that is detachably attached to an image forming apparatus.

11. a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit each including the yellow developer, the magenta developer, the cyan developer, and the black developer separately, respectively, of the electrostatic image developer set according to claim 9; a first developing means including the first developer of the electrostatic image developer set according to claim 9; a second developing means including the second developer of the electrostatic image developer set according to claim 9; Equipped with A process cartridge that is detachably attached to an image forming apparatus.

12. a yellow image forming unit, a magenta image forming unit, a cyan image forming unit, and a black image forming unit, which form a yellow image, a magenta image, a cyan image, and a black image, respectively, using the yellow toner, the magenta toner, the cyan toner, and the black toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; a first image forming unit for forming a first image using the first toner of the toner set for developing an electrostatic image according to any one of claims 1 to 8; A second image forming unit that forms a second image using the second toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a transfer means for transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing unit for fixing a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming apparatus comprising:

13. 13. The image forming apparatus according to claim 12, wherein the layer of the toner image farthest from the recording medium is the first image, and the layer of the toner image second farthest from the recording medium is the second image.

14. a yellow image forming step, a magenta image forming step, a cyan image forming step, and a black image forming step, in which a yellow image, a magenta image, a cyan image, and a black image are formed by using the yellow toner, the magenta toner, the cyan toner, and the black toner, respectively, of the toner set for developing an electrostatic image according to any one of claims 1 to 8; A first image forming step of forming a first image using the first toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; A second image forming step of forming a second image using the second toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a transfer step of transferring the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image onto a recording medium; a fixing step of fixing a toner image, in which the yellow image, the magenta image, the cyan image, the black image, the first image, and the second image are stacked, onto the recording medium; An image forming method comprising:

15. 15. The image forming method according to claim 14, wherein the layer of the toner image farthest from the recording medium is the first image, and the layer of the toner image second farthest from the recording medium is the second image.

Images