Fluorescent green toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Abstract

To provide a fluorescent green toner which offers superior capability to suppress gloss steps in formed images.SOLUTION: A fluorescent green toner is provided, comprising toner particles containing a binder resin, a mold release agent, a fluorescent pigment having a hydrophilic group, and a pigment having a halogen atom.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a fluorescent green toner, an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method. [Background technology]

[0002] Patent Document 1 discloses a fluorescent green toner comprising CI solvent green 5 and phthalocyanine-based coloring agent compound X, wherein the content of CI solvent green 5 in the total amount of coloring agents is 5% by mass or more and 50% by mass or less.

[0003] Patent Document 2 discloses a coloring composition for color filters, characterized by comprising a fluorescent dye (A), an organic compound represented by general formula (1) (B), and a binder resin (C). General formula (1) P-Lm [In general formula (1), P: Organic pigment skeleton or aminobenzene skeleton L:L consists of a basic functional group Lb, an acidic functional group La, or a functional group Lp having a phthalimide skeleton. m: An integer between 1 and 4, representing the functional cardinal. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2012-189989 [Patent Document 2] Japanese Patent Publication No. 2013-101166 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present disclosure aims to provide a fluorescent green toner that is superior in suppressing gloss unevenness in the resulting image compared to the case where toner particles contain a binder resin, a release agent, a fluorescent pigment having a hydrophilic group, and a pigment having no halogen atom. **Means for Solving the Problems**

[0006] Specific means for solving the above problems include the following aspects. <1> A fluorescent green toner containing toner particles containing a binder resin, a release agent, a fluorescent pigment having a hydrophilic group, and a pigment having a halogen atom. <2> The fluorescent green toner according to <1>, wherein the pigment having a halogen atom is a phthalocyanine compound. <3> The fluorescent green toner according to <1> or <2>, wherein the pigment having a halogen atom has at least one selected from the group consisting of a chlorine atom and a bromine atom as the halogen atom. <4> The fluorescent green toner according to any one of <1> to <3>, wherein the pigment having a halogen atom has 4 or more halogen atoms. <5> The fluorescent green toner according to <4>, wherein the pigment having a halogen atom has 8 or more halogen atoms. <6> The fluorescent green toner according to any one of <1> to <5>, wherein the fluorescent pigment having a hydrophilic group has a hydroxy group as the hydrophilic group. <7> The fluorescent green toner according to <6>, wherein the ratio of the molecular weight of the hydroxy group to the molecular weight of the entire molecule of the fluorescent pigment having a hydrophilic group is 12% by mass or less. <8> The fluorescent green toner according to any one of <1> to <7>, wherein the fluorescent pigment having a hydrophilic group is an azomethine compound. <9> The fluorescent green toner according to any one of <1> to <8>, wherein the release agent is 2% by mass or more and 20% by mass or less based on the total mass of the toner particles. <10> The fluorescent green toner according to any one of <1> to <9>, wherein the release agent is paraffin wax or polyethylene wax. <11> The domain diameter of the release agent in the toner particles is 25% or less of the volume-average particle size of the toner particles. <1> ~ <10> Fluorescent green toner as described in one of the following. <12> The toner particles have a core-shell structure <1> ~ <11> Fluorescent green toner as described in one of the following. <13> <1> ~ <12> A electrostatic image developer containing the fluorescent green toner described in any one of the following. <14> <1> ~ <12> A toner cartridge containing the fluorescent green toner described in one of the following, which is attached to and detached from an image forming apparatus. <15> <13> A process cartridge that contains the electrostatic image developer described above, and includes a developing means for developing an electrostatic image formed on the surface of an image holder as a toner image using the electrostatic image developer, and is attached to and detached from an image forming apparatus. <16> An image holder, a charging means for charging the surface of the image holder, and a static charge image forming means for forming a static charge image on the charged surface of the image holder, <13> An image forming apparatus comprising: a developing means for containing the electrostatic image developer described in [reference] and developing an electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer; a transfer means for transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing means for fixing the toner image transferred to the surface of the recording medium. <17> A charging step of charging the surface of the image holder, and a static charge image forming step of forming a static charge image on the charged surface of the image holder, <13> An image forming method comprising: a developing step of developing an electrostatic image formed on the surface of an image holder as a toner image using the electrostatic image developer described in [reference]; a transfer step of transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium. <18> The system comprises first to sixth image forming units of an electrophotographic method that form images of pink, yellow, magenta, cyan, black, and green, and the image forming unit that forms the green image is <13> An image forming apparatus containing the electrostatic image developer described above. <19> The system has first to sixth image forming steps in an electrophotographic method for forming images of pink, yellow, magenta, cyan, black, and green, and the image forming step for forming the green image is <13> An image formation method using the electrostatic image developer described above. [Effects of the Invention]

[0007] <1> or <12> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the toner particles contain a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment that does not have halogen atoms. <2> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the pigment having the halogen atom is an azomethine pigment other than a phthalocyanine compound. <3> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the pigment having halogen atoms has only fluorine atoms or elemental atoms as halogen atoms. <4> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the pigment having halogen atoms has fewer than four halogen atoms. <5> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the pigment having halogen atoms has fewer than eight halogen atoms. <6> According to the invention, a fluorescent green toner is provided in which the hydrophilic group-containing fluorescent pigment exhibits superior gloss step suppression in the resulting image compared to the case where the hydrophilic group consists solely of a carboxyl group. <7> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to the case where the ratio of the molecular weight of the hydroxyl group to the total molecular weight of one molecule of the hydrophilic fluorescent pigment exceeds 12% by mass. <8> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the hydrophilic group-containing fluorescent pigment is a triphenylmethane compound. <9> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to cases where the release agent is less than 2% by mass or more than 20% by mass of the total mass of the toner particles. <10> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the release agent is an ester wax. <11> According to the invention, a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the domain diameter of the release agent in the toner particles is greater than 25% of the volume-average particle size of the toner particles. <13> , <14> , <15> , <16> , <17> , <18> or <19> According to the invention, an electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, or image forming method is provided that exhibits superior gloss step suppression in the resulting image compared to cases where the toner particles in the fluorescent green toner contain a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment without halogen atoms. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an example of an image forming apparatus according to this embodiment. [Figure 2] This is a schematic diagram showing an example of a process cartridge that can be attached to and detached from the image forming apparatus according to this embodiment. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure are described below. These descriptions and embodiments are illustrative and do not limit the scope of the embodiments.

[0010] In this disclosure, the numerical range indicated using "~" represents a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples.

[0011] In this disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, provided that their objectives are achieved.

[0012] When embodiments are described in this disclosure with reference to the drawings, the configuration of such embodiments is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each figure are conceptual, and the relative relationships between the components are not limited thereto.

[0013] In this disclosure, each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition in this disclosure, if there are multiple types of the substance corresponding to each component in the composition, it means the total amount of those multiple types of substances present in the composition unless otherwise specified. In this disclosure, each component may contain multiple types of particles. If multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to the value for a mixture of such multiple types of particles present in the composition, unless otherwise specified.

[0014] In this disclosure, "(meth)acrylic" is a term that includes both acrylic and methacrylic, and "(meth)acrylate" is a term that includes both acrylate and methacrylate.

[0015] In the present disclosure, the "toner for electrostatic charge image development" is also referred to as "toner", the "fluorescent green toner" is also referred to as "green toner", the "electrostatic charge image developer" is also referred to as "developer", and the "carrier for electrostatic charge image development" is also referred to as "carrier".

[0016] <Fluorescent green toner> The fluorescent green toner according to this embodiment includes toner particles containing a binder resin, a release agent, a fluorescent pigment having a hydrophilic group, and a pigment having a halogen atom. Further, the fluorescent green toner according to this embodiment is a toner for electrostatic charge image development, and means a toner in which the hue angle h of a solid image formed on coated paper is 120° or more and 150° or less. The hue angle h is the angle calculated by the following formula from the a * a * b * value and the b * value in the CIE1976L * color system. Hue angle h = tan -1 (b * / a * ) In the present disclosure, the hue angle h of the green toner is 120° or more and 150° or less, preferably 128.5° or more and 144.5° or less, and more preferably 135° or more and 140° or less. Furthermore, the fluorescent green toner according to this embodiment is preferably a toner having a core-shell structure.

[0017] The CIE1976L * a * b * coordinate values of the color system are measured by the following method. After mixing the fluorescent green toner to be a sample with a carrier, it is put into a developing device of an image forming apparatus, and a solid image (image with a density of 100%) with a toner loading amount of 4.0 g / m 2 is formed on OS coated paper (manufactured by Oji Paper Co., Ltd., product name: OS Coat 127) at a fixing temperature of 180°C. For the formed solid image, the CIE1976L * a * b *The coordinate values ​​of the color system were measured at 10 random locations using a reflectance spectrodensitometer X-Rite939 (aperture diameter 4 mm, X-Rite Corporation), and L * value, a * Value and b * Calculate the average value.

[0018] Conventional fluorescent green toners are often formulated using a mixture of fluorescent yellow dye and phthalocyanine pigment because there is no single colorant that produces a fluorescent green color. However, since a dye is used for the fluorescent yellow, there is a problem of color transfer when it comes into contact with polyvinyl chloride products containing plasticizers. On the other hand, when a fluorescent yellow pigment is used with a fluorescent green toner, the aforementioned color transfer does not occur, but the release agent does not seep out well, and image roughness occurs in the non-image history area on the fixing belt where there is no release agent from the previous image. When roughness is present on the image surface, ultraviolet light, which is the excitation light for the fluorescent toner, has difficulty reaching the pigment due to surface scattering, so the fluorescence intensity decreases compared to areas without image roughness. As a result, the inventors have found that in fluorescent toners, a noticeable difference in gloss can be observed between areas with and without image roughness. In this embodiment of the fluorescent green toner, by including a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment having halogen atoms, the resulting image exhibits excellent gloss step suppression. It is hypothesized that by using a green pigment that is more hydrophobic due to the effect of halogen atoms in pigments containing halogen atoms, adhesion to the equally hydrophobic release agent is strengthened, causing the green pigment and release agent to adhere to and disperse each other, suppressing the uneven distribution of the release agent, improving the seepage of the release agent during fixing, suppressing surface roughness of the image, and suppressing gloss steps.

[0019] In this embodiment, a fluorescent pigment is a pigment that emits light in response to external light energy, and a non-fluorescent pigment is a pigment that does not emit light in response to external light energy. Generally, fluorescent pigments exhibit color through both reflected and emitted light, while non-fluorescent pigments exhibit color through reflected light only.

[0020] The configuration of the fluorescent green toner according to this embodiment will be described in detail below.

[0021] [Toner particles] The toner particles contain a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment having halogen atoms, and optionally include other additives.

[0022] -Fluorescent pigments with hydrophilic groups- The toner particles contain a fluorescent pigment that has hydrophilic groups. The fluorescent pigment having the hydrophilic group is preferably a yellow fluorescent pigment from the viewpoint of suppressing gloss step, brightness, and saturation of the resulting image. Furthermore, the fluorescent pigment having the hydrophilic group preferably has an emission peak in the wavelength region of 500 nm to 550 nm in the emission spectrum, from the viewpoint of suppressing gloss step differences, brightness, and saturation of the resulting image.

[0023] Examples of hydrophilic groups in the aforementioned fluorescent pigments include hydroxyl groups, primary to tertiary amino groups, carboxyl groups, sulfo groups, and phosphate groups. In particular, from the viewpoint of suppressing gloss step differences in the resulting image, it is preferable that the hydrophilic group of the fluorescent pigment has a hydroxyl group.

[0024] Examples of fluorescent pigments having hydrophilic groups include azomethine compounds, isoindolinone compounds, xanthene compounds (including rhodamine compounds, fluorescein compounds, and eosin compounds), naphthalene compounds, and triarylmethane compounds, all of which have hydrophilic groups. In particular, the fluorescent pigment having the hydrophilic group is preferably an azomethine compound, and more preferably a bizuazomethine compound, from the viewpoint of suppressing gloss step differences in the resulting image. Azomethine compounds include -R 1 C=N-(R 1 Examples include compounds having an azomethine structure represented by a hydrogen atom or a monovalent substituent. As for bisazometine compounds, -R 1 C=NN=CR 2 -(R 1 and R 2 Examples include compounds having a bisazomethine structure in their molecular structure, each independently represented by a hydrogen atom or a monovalent substituent.

[0025] Examples of fluorescent pigments having hydrophilic groups include the following azomethine compounds (1) to (3).

[0026] [ka]

[0027] The emission peak wavelength of azomethine compound (1) is 520 nm. The emission peak wavelength of azomethine compound (2) is 510 nm. The emission peak wavelength of azomethine compound (3) is 520 nm.

[0028] The fluorescent pigment having a hydrophilic group is preferably at least one selected from the group consisting of azomethine compound (1), azomethine compound (2), and azomethine compound (3).

[0029] Furthermore, CI Pigment Yellow 101 is preferred as a fluorescent pigment having hydrophilic groups. CI Pigment Yellow 101 is an azomethine compound (1).

[0030] The ratio of the molecular weight of the hydroxyl group to the total molecular weight of one molecule of the hydrophilic fluorescent pigment is preferably 20% by mass or less, more preferably 12% by mass or less, even more preferably greater than 0% by mass and 12% by mass or less, and particularly preferably 5% by mass or more and 12% by mass or less, from the viewpoint of suppressing gloss step differences in the resulting image.

[0031] The volume-average particle size D1 of the fluorescent pigment having hydrophilic groups is preferably 50 nm to 800 nm, more preferably 150 nm to 600 nm, and even more preferably 250 nm to 400 nm, from the viewpoint of achieving a good balance of dispersibility in toner particles, color development on the recording medium, and fixation on the recording medium. The volume-average particle size of a pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction particle size distribution analyzer (e.g., LA-700 from Horiba, Ltd.). The volume-based particle size distribution is plotted from the smallest particle size side, and the particle size at which the cumulative total reaches 50% is defined as the volume-average particle size.

[0032] The fluorescent pigment having a hydrophilic group may be included alone or in combination of two or more types, but from the viewpoint of brightness and saturation of the resulting image, it is preferable to include only one type. The content of the fluorescent pigment having hydrophilic groups is preferably 0.1% to 30% by mass, more preferably 0.5% to 25% by mass, even more preferably 1% to 20% by mass, and particularly preferably 5% to 15% by mass, relative to the total toner particles, from the viewpoint of suppressing gloss step differences in the resulting image, brightness, and saturation. Furthermore, from the viewpoint of suppressing gloss steps in the resulting image, it is preferable that the content of fluorescent pigments having hydrophilic groups is greater than the content of pigments having halogen atoms.

[0033] -Pigments containing halogen atoms- The toner particles contain a pigment having halogen atoms. The pigment having the halogen atom is preferably a non-fluorescent pigment, and more preferably a non-fluorescent green pigment, from the viewpoint of suppressing gloss step, brightness, and saturation of the resulting image. Furthermore, from the viewpoint of suppressing gloss step differences in the resulting image, brightness, and saturation, it is preferable that the pigment having the halogen atom has a reflectance peak in the region of the reflectance spectrum with wavelengths between 480 nm and 540 nm.

[0034] Examples of halogen atoms in the aforementioned pigments include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. In particular, from the viewpoint of suppressing gloss step differences in the resulting image, the pigment having halogen atoms preferably has at least one selected from the group consisting of chlorine atoms and bromine atoms, and more preferably has both chlorine atoms and bromine atoms. Furthermore, from the viewpoint of suppressing gloss step differences in the resulting image, the pigment having halogen atoms preferably has two or more halogen atoms, more preferably four or more halogen atoms, even more preferably six or more halogen atoms, and particularly preferably eight to 32 halogen atoms.

[0035] Examples of pigments having halogen atoms include lake pigments of halogenated phthalocyanine compounds and halogenated triphenylmethane dyes. As the pigment having the halogen atom, a halogenated phthalocyanine compound is preferred, and at least one selected from the group consisting of copper phthalocyanine halide and zinc phthalocyanine halide is preferred. Examples of copper phthalocyanine halides include CI Pigment Green 7 (hue: bluish-green, containing 15 chlorine atoms), CI Pigment Green 36 (hue: yellowish-green, containing 10 chlorine atoms and 6 bromine atoms), and CI Pigment Blue 76 (hue: blue, containing 8 to 12 chlorine atoms). Examples of zinc halide phthalocyanines include CI Pigment Green 58 (hue: green, containing 3 chlorine atoms and 13 bromine atoms) and CI Pigment Green 59 (hue: green, containing 0 to 16 chlorine atoms and 0 to 16 bromine atoms).

[0036] The pigment having the halogen atom is preferably at least one selected from the group consisting of CI Pigment Green 7, CI Pigment Green 36, CI Pigment Green 58, CI Pigment Green 59, and CI Pigment Blue 76.

[0037] The volume-average particle size D2 of the pigment having the halogen atom is preferably 50 nm to 300 nm, more preferably 100 nm to 250 nm, and even more preferably 120 nm to 200 nm, from the viewpoint of achieving a good balance of dispersibility in toner particles, color development on the recording medium, and fixation on the recording medium.

[0038] The pigment containing halogen atoms may be included individually or in combination of two or more types. The content of the pigment containing halogen atoms is preferably 0.1% to 30% by mass, more preferably 0.2% to 20% by mass, even more preferably 0.5% to 20% by mass, and particularly preferably 1% to 15% by mass, relative to the total toner particles, from the viewpoint of suppressing gloss step differences in the resulting image, brightness, and saturation. Furthermore, from the viewpoint of suppressing gloss steps in the resulting image, it is preferable that the content of fluorescent pigments having hydrophilic groups is greater than the content of pigments having halogen atoms.

[0039] The ratio D1 / D2 of the volume-average particle size D1 of the hydrophilic fluorescent pigment to the volume-average particle size D2 of the halogen atom pigment is preferably 1 to 3, more preferably 1.2 to 2.5, and even more preferably 1.5 to 2, from the viewpoint of increasing the brightness and saturation of the resulting image.

[0040] In the toner particles, the mass-based ratio M2 / M1 of the content M1 of the fluorescent pigment having a hydrophilic group to the content M2 of the pigment having a halogen atom is preferably 0.05 or more and 1.5 or less, from the viewpoint of increasing the brightness and saturation of the resulting image. Furthermore, from the viewpoint of increasing the saturation of the resulting image, the ratio M2 / M1 should be 0.05 or higher, preferably 0.1 or higher, and more preferably 0.3 or higher. Furthermore, from the viewpoint of increasing the brightness of the resulting image, the ratio M2 / M1 is 1.5 or less, preferably 1.0 or less, more preferably less than 1.0, and even more preferably 0.8 or less.

[0041] Preferably, the total content of the fluorescent pigment having a hydrophilic group and the pigment having a halogen atom relative to the entire toner particle is 5% by mass or more and 20% by mass or less. Furthermore, from the viewpoint of increasing the saturation of the resulting image, the total content of both pigments is 5% by mass or more, preferably 8% by mass or more, and more preferably 10% by mass or more. Furthermore, from the viewpoint of increasing the brightness of the resulting image, the total content of both pigments is preferably 18% by mass or less, and more preferably 15% by mass or less.

[0042] From the viewpoint of increasing the brightness and saturation of the resulting image, the wavelength difference between the emission peak of the hydrophilic fluorescent pigment having hydrophilic groups that is present in the largest amount among the toner particles and the reflection peak of the halogen atom pigment having halogen atoms that is present in the green toner particles is preferably 40 nm or less, more preferably 30 nm or less, even more preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 0 nm.

[0043] The toner particles may contain other colorants besides the fluorescent pigment having a hydrophilic group and the pigment having a halogen atom. The total amount of the fluorescent pigment having a hydrophilic group and the pigment having a halogen atom in the total colorant contained in the toner particles is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass.

[0044] -Binding resin- Examples of binder resins include vinyl resins consisting of monomer homopolymers of 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 (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), etc., or copolymers of two or more of these monomers. Examples of binder resins 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 aforementioned vinyl resins; and graft polymers obtained by polymerizing vinyl monomers in the presence of these. These binding resins may be used individually or in combination of two or more types.

[0045] Polyester resin is preferred as the binder resin. Examples of polyester resins include well-known polyester resins.

[0046] Examples of polyester resins include condensation polymers of polycarboxylic acids and polyhydric alcohols. Commercially available polyester resins may be used, or synthetically produced ones may be used.

[0047] Examples of polycarboxylic 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.), their anhydrides, or their lower alkyl esters (e.g., with 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids. As the polycarboxylic acid, a trivalent or higher carboxylic acid with a crosslinked or branched structure may be used in combination with the dicarboxylic acid. Examples of trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, their anhydrides, or their lower alkyl esters (e.g., having 1 to 5 carbon atoms). Polycarboxylic acids may be used individually or in combination of two or more.

[0048] 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, aromatic diols and alicyclic diols are preferred as polyhydric alcohols, and aromatic diols are more preferred. As for the polyhydric alcohol, a trihydric or higher polyhydric alcohol with a cross-linked or branched structure may be used in combination with the diol. Examples of trihydric or higher polyhydric alcohols include glycerin, trimethylolpropane, and pentaerythritol. Polyhydric alcohols may be used individually or in combination of two or more types.

[0049] The glass transition temperature (Tg) of the polyester resin is preferably 50°C to 80°C, and more preferably 50°C to 65°C. The glass transition temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, from the "extracorporeal glass transition onset temperature" described in the method for determining the glass transition temperature in JIS K7121-1987 "Method for Measuring the Transition Temperature of Plastics".

[0050] The weight-average molecular weight (Mw) of the polyester resin is preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000. The number-average molecular weight (Mn) of the polyester resin is preferably between 2,000 and 100,000. The molecular weight distribution (Mw / Mn) of the polyester resin is preferably 1.5 to 100, and more preferably 2 to 60. Weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). GPC molecular weight measurement is performed using a Tosoh GPC-HLC-8120GPC analyzer, a Tosoh TSKgel SuperHM-M (15cm) column, and THF solvent. The weight-average molecular weight and number-average molecular weight are calculated from these measurement results using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples.

[0051] Polyester resins can be obtained by known manufacturing methods. Specifically, for example, they can be obtained by a method in which the polymerization temperature is set to 180°C or higher and 230°C or lower, and the reaction system is subjected to reduced pressure as needed, while removing water and alcohol generated during condensation. If the monomers of the raw materials do not dissolve or miscible at the reaction temperature, a high-boiling point solvent may be added as a solubilizer to dissolve them. In this case, the polycondensation reaction should be carried out while distilling off the solubilizer. If there are monomers with poor miscibility, it is advisable to condense the poorly miscible monomers with the acid or alcohol to be polycondensed with them beforehand, and then polycondense them with the main component.

[0052] The binder resin content is preferably 40% to 95% by mass, more preferably 50% to 90% by mass, and even more preferably 60% to 85% by mass, relative to the total toner particles.

[0053] -Release agent- Examples of release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum-based waxes such as montan wax; and ester waxes such as fatty acid esters and montanic acid esters. However, the release agents are not limited to these. In particular, from the viewpoint of suppressing gloss steps in the resulting image, hydrocarbon waxes are preferred, and paraffin waxes or polyethylene waxes are more preferred.

[0054] The melting temperature of the release agent is preferably 50°C to 110°C, and more preferably 60°C to 100°C. The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) using the "melting peak temperature" described in JIS K7121-1987 "Method for determining the transition temperature of plastics".

[0055] From the viewpoint of suppressing gloss step differences in the resulting image, the domain diameter of the release agent in the toner particles is preferably 40% or less of the particle size of the toner particles, more preferably 25% or less, and particularly preferably 5% to 15% of the particle size of the toner particles.

[0056] The following describes the method for measuring the domain diameter of the mold release agent. The domain diameter of the release agent can be determined by cross-sectional observation of the toner.

[0057] The method for observing the cross-section of toner particles is as follows: Toner particles (or toner particles with external additives attached) are mixed with epoxy resin and embedded, and the epoxy resin is solidified. The resulting solidified material is cut using an ultramicrotome (Leica UltracutUCT) to prepare thin section samples with a thickness of 80 nm to 130 nm. Next, the obtained thin section samples are stained with ruthenium tetroxide in a desiccator at 30°C for 3 hours. Then, transmission mode STEM observation images (acceleration voltage: 30 kV, magnification: 20,000x) of the stained thin section samples are obtained using an ultra-high resolution field emission scanning electron microscope (FE-SEM, Hitachi High-Technologies Corporation S-4800). Within toner particles, the binder resin (crystalline resin and amorphous resin) and release agent are identified based on contrast and shape. In STEM observation images, the binder resin other than the release agent has many double bonds and is stained by ruthenium tetroxide, thus distinguishing the release agent portion from the resin portion other than the release agent. More specifically, with ruthenium staining, the release agent is stained lightest, followed by the crystalline resin (e.g., crystalline polyester resin), and the amorphous resin (e.g., amorphous polyester resin) is stained darkest. By adjusting the contrast, the release agent appears white, the amorphous resin black, and the crystalline resin light gray. In this way, the domains of the release agent can be identified.

[0058] The domain diameter of the release agent is determined by the following method. First, using the aforementioned STEM observation images, domains of the release agent having domains of 0.5 μm or larger are extracted from each toner particle, the maximum diameter of these domains is determined, and their arithmetic mean values ​​are calculated. The same process is performed for 100 toner particles, and the arithmetic mean of the values ​​obtained for these 100 toner particles is calculated and defined as the "domain diameter of the release agent."

[0059] The release agent content is preferably 1% to 20% by mass, more preferably 2% to 20% by mass, and even more preferably 3% to 15% by mass, relative to the total mass of toner particles.

[0060] -Other additives- Other known additives include, for example, magnetic materials, charge control agents, and inorganic powders. These additives are included in the toner particles as internal additives.

[0061] -Characteristics of toner particles, etc.- The toner particles may be single-layer toner particles, or they may be toner particles with a so-called core-shell structure, consisting of a core (core particle) and a coating layer (shell layer) that covers the core. The core-shell structure of the toner particles may consist of, for example, a core made up of a binder resin and, if necessary, other additives such as a colorant and a release agent, and a coating layer made up of a binder resin.

[0062] The volume-average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

[0063] The average particle size and particle size distribution indices of toner particles are measured using the Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte is measured using the ISOTON-II (manufactured by Beckman Coulter). For measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate) as a dispersant. This is then added to 100 ml to 150 ml of electrolyte. The electrolyte containing the suspended sample is dispersed in an ultrasonic disperser for 1 minute. The particle size distribution of particles with a diameter of 2 μm to 60 μm is then measured using a Coulter Multisizer II with a 100 μm aperture. The number of particles sampled is 50,000. Based on the measured particle size distribution, a cumulative distribution of volume and number is drawn for each divided particle size range (channel) from the smallest diameter side. The particle size at which the cumulative total reaches 16% is defined as the volume particle size D16v and the number particle size D16p, the particle size at which the cumulative total reaches 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size at which the cumulative total reaches 84% ​​is defined as the volume particle size D84v and the number particle size D84p. Using these, the volume particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 The GSDp index is (D84p / D16p) 1 / 2 It is calculated as follows.

[0064] The average circularity of the toner particles is preferably 0.94 to 1.00, and more preferably 0.95 to 0.98.

[0065] The average circularity of toner particles is determined by (circular equivalent perimeter) / (perimeter) [(perimeter of a circle with the same projected area as the particle image) / (perimeter of the particle projection image)]. Specifically, it is a value measured by the following method. First, the toner particles to be measured are collected by suction, a flattened flow is formed, and a still image of the particles is captured by instantaneous strobe flashing. This particle image is then analyzed using a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation). The number of samples used to determine the average circularity is 3500. If the toner contains external additives, 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 additives have been removed.

[0066] [External Additives] Examples of external additives include inorganic particles. These include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n Examples include Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, and MgSO4.

[0067] The surface of the inorganic particles used as an external additive should preferably be hydrophobic. Hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic agent. The hydrophobic agent is not particularly limited, but examples include silane-based coupling agents, silicone oil, titanate-based coupling agents, and aluminum-based coupling agents. These may be used individually or in combination of two or more. The amount of hydrophobic treatment agent is typically, for example, 1 to 10 parts by mass per 100 parts by mass of inorganic particles.

[0068] Examples of external additives include resin particles (such as polystyrene, polymethyl methacrylate, and melamine resin) and cleaning activators (for example, metal salts of higher fatty acids represented by zinc stearate, and fluorine-based high molecular weight particles).

[0069] The amount of external additive added is preferably 0.01% by mass or more and 5% by mass or less relative to the toner particles, and more preferably 0.01% by mass or more and 2.0% by mass or less.

[0070] In this embodiment, the fluorescent green toner preferably has a reflectance of 70% or more in the reflectance peak of the spectral reflectance spectrum for a solid image formed on coated paper.

[0071] -Manufacturing method for fluorescent green toner- The fluorescent green toner according to this embodiment is obtained by manufacturing toner particles and then adding an external additive to the toner particles.

[0072] Toner particles may be manufactured by either a dry process (e.g., kneading and grinding) or a wet process (e.g., agglomeration, suspension polymerization, dissolution and suspension). There are no particular restrictions on these methods, and known methods can be used. Among these, obtaining toner particles by agglomeration is preferable.

[0073] When manufacturing toner particles by an aggregation and coalescence method, the following manufacturing method is preferred. The process involves preparing a resin particle dispersion in which resin particles that will serve as the binder are dispersed (resin particle dispersion preparation process); A step of preparing a hydrophilic fluorescent pigment dispersion in which hydrophilic fluorescent pigments are dispersed (a step of preparing a hydrophilic fluorescent pigment dispersion); A step of preparing a halogen-containing pigment dispersion in which a pigment containing halogen atoms is dispersed (a step of preparing a halogen-containing pigment dispersion); The process involves a step of agglomerating the mixed particles in a mixed dispersion obtained by mixing a resin particle dispersion, a fluorescent pigment dispersion having hydrophilic groups, and a pigment dispersion having halogen atoms, thereby forming aggregated particles (aggregated particle formation step); A manufacturing method comprising the steps of: heating an aggregated particle dispersion containing dispersed aggregated particles to fuse and combine the aggregated particles to form green toner particles (fusion and combination step);

[0074] The details of each step are explained below.

[0075] -Resin particle dispersion preparation process- A resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0076] Examples of dispersion media used in resin particle dispersions include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0077] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0078] In resin particle dispersions, common dispersion methods for dispersing resin particles in a dispersion medium include, for example, rotary shear homogenizers, ball mills with media, sand mills, and dyno mills. Depending on the type of resin particles, the resin particles may also be dispersed in the dispersion medium by phase inversion emulsification. Phase inversion emulsification 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 neutralize the organic continuous phase (O phase), and then an aqueous medium (W phase) is added to perform a phase inversion from W / O to O / W, thereby dispersing the resin in particulate form in the aqueous medium.

[0079] The volume-average particle size of the resin particles dispersed in the resin particle dispersion is preferably 0.01 μm to 1 μm, more preferably 0.08 μm to 0.8 μm, and even more preferably 0.1 μm to 0.6 μm. The volume-average particle size of the resin particles is measured using a laser diffraction particle size distribution analyzer (e.g., LA-700 manufactured by Horiba, Ltd.). The cumulative distribution is subtracted from the smallest particle size side for each divided particle size range (channel), and the particle size that accounts for 50% of the total particle size is measured as the volume-average particle size D50v. The volume-average particle size of particles in other dispersions is measured in the same manner.

[0080] The resin particle content in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0081] The method for preparing the release agent particle dispersion is the same as for the resin particle dispersion. The release agent particle content in the release agent particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0082] -Preparation process for a dispersion of fluorescent pigments having hydrophilic groups- A dispersion of a hydrophilic fluorescent pigment is prepared, for example, by dispersing a hydrophilic fluorescent pigment in a dispersion medium with a surfactant.

[0083] Examples of dispersion media used in dispersions of fluorescent pigments having hydrophilic groups include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0084] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0085] Methods for dispersing fluorescent pigments having hydrophilic groups in a dispersion medium include, for example, dispersion methods using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, a key mill, etc.

[0086] The volume-average particle size of the hydrophilic fluorescent pigment dispersed in the hydrophilic fluorescent pigment dispersion is preferably 50 nm to 800 nm, more preferably 150 nm to 600 nm, and even more preferably 250 nm to 400 nm. The particle size of the hydrophilic fluorescent pigment can be adjusted, for example, by the dispersion method and time.

[0087] The content of the hydrophilic fluorescent pigment in the hydrophilic fluorescent pigment dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0088] -Preparation process for pigment dispersion containing halogen atoms- A pigment dispersion containing halogen atoms can be prepared, for example, by dispersing a pigment containing halogen atoms in a dispersion medium using a surfactant.

[0089] Examples of dispersion media used in pigment dispersions containing halogen atoms include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0090] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0091] Methods for dispersing pigments containing halogen atoms in a dispersion medium include, for example, dispersion methods using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, a key mill, etc.

[0092] The volume-average particle size of the halogen-containing pigment dispersed in the halogen-containing pigment dispersion is preferably 50 nm to 300 nm, more preferably 100 nm to 250 nm, and even more preferably 120 nm to 200 nm. The particle size of the halogen-containing pigment can be adjusted, for example, by the dispersion method and time.

[0093] The content of the halogen-containing pigment in the halogen-containing pigment dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0094] -Agglomerated particle formation process- A resin particle dispersion, a fluorescent pigment dispersion having hydrophilic groups, a pigment dispersion having halogen atoms, and a release agent particle dispersion are mixed. Then, in the mixed dispersion, the resin particles, the fluorescent pigment having hydrophilic groups, the pigment having halogen atoms, and the release agent particles are heteroaggregated to form aggregated particles containing the resin particles, the fluorescent pigment having hydrophilic groups, the pigment having halogen atoms, and the release agent particles, which have a diameter close to the diameter of the target toner particles.

[0095] Specifically, for example, a coagulant is added to a mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, pH 2 to 5), a dispersion stabilizer is added as needed, and then the mixture is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, above -30°C or below -10°C), causing the particles dispersed in the mixed dispersion to coagulate and form coagulated particles. In the agglomerated particle formation process, for example, the mixed dispersion may be stirred in a rotary shear homogenizer, a flocculant may be added at room temperature (e.g., 25°C), the pH of the mixed dispersion may be adjusted to acidic (e.g., pH 2 to 5), a dispersion stabilizer may be added as needed, and then heating may be performed.

[0096] Examples of flocculants include surfactants with opposite polarity to the surfactant contained in the mixed dispersion, inorganic metal salts, and metal complexes with a valency of 2 or higher. When a metal complex is used as a flocculant, the amount of surfactant used is reduced and the electrostatic properties are improved. Along with the flocculant, an additive that forms a complex or similar bond with the metal ions of the flocculant may be used as needed. A chelating agent is preferably used as this additive.

[0097] 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; and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. As a chelating agent, a water-soluble chelating agent may be used. Examples of chelating agents include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; and aminocarboxylic acids such as iminodiacid acetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA). The amount of chelating agent added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of resin particles, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass.

[0098] -Fusion / unification process- Next, the dispersion of aggregated particles is heated to a temperature above the glass transition temperature of the resin particles (for example, 10°C to 30°C higher than the glass transition temperature of the resin particles) to fuse and combine the aggregated particles and form toner particles.

[0099] Toner particles are obtained through the above process. Toner particles may be manufactured by first obtaining an aggregate particle dispersion in which aggregate particles are dispersed, then further mixing the aggregate particle dispersion with a resin particle dispersion in which resin particles are dispersed, and agglomerating the aggregate particles so that the resin particles adhere to the surface of the aggregate particles to form second aggregate particles, and then heating the second aggregate particle dispersion in which the second aggregate particles are dispersed to fuse and combine the second aggregate particles to form toner particles with a core-shell structure.

[0100] After the fusion and combination process is completed, the toner particles in the dispersion are subjected to known washing, solid-liquid separation, and drying processes to obtain dried toner particles. From the viewpoint of electrostatic properties, the washing process should be performed thoroughly by displacement washing with ion-exchanged water. From the viewpoint of productivity, the solid-liquid separation process should be performed by suction filtration, pressure filtration, etc. From the viewpoint of productivity, the drying process should be performed by freeze-drying, air-flow drying, fluidized bed drying, vibratory fluidized bed drying, etc.

[0101] The toner according to this embodiment is manufactured, for example, by adding an external additive to the obtained dried toner particles and mixing them. Mixing is preferably carried out using a V-blender, Henschel mixer, Lödige mixer, etc. Furthermore, if necessary, coarse particles of the toner may be removed using a vibrating screen separator, a wind screen separator, etc.

[0102] <Electrostatic Image Developer> The electrostatic image developer according to this embodiment includes at least the green toner according to this embodiment. The electrostatic image developer according to this embodiment may be a one-component developer containing only the green toner according to this embodiment, or it may be a two-component developer in which the green toner and a carrier are mixed.

[0103] There are no particular restrictions on the carriers, and known carriers can be used. Examples of carriers include coated carriers in which a resin is coated on the surface of a core material made of magnetic powder; magnetic powder dispersed carriers in which magnetic powder is dispersed in a matrix resin; and resin-impregnated carriers in which resin is impregnated into porous magnetic powder. Magnetic powder dispersion carriers and resin-impregnated carriers may be carriers in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with resin.

[0104] Examples of magnetic powders include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0105] Examples of coating resins and matrix resins 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 or modified thereof containing organosiloxane bonds, fluororesin, polyester, polycarbonate, phenolic resin, epoxy resin, etc. The coating resin and matrix resin may also contain conductive particles and other additives. Examples of conductive particles include metals such as gold, silver, and copper, carbon black, titanium dioxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, etc.

[0106] To coat the surface of the core material with resin, one method is to coat it with a coating layer-forming solution prepared by dissolving the coating resin and various additives (used as needed) in a suitable solvent. The solvent is not particularly limited and should be selected considering the type of resin used and its suitability for coating. Specific resin coating methods include the immersion method, in which the core material is immersed in a coating layer forming solution; the spray method, in which the coating layer forming solution is sprayed onto the surface of the core material; the fluidized bed method, in which the coating layer forming solution is sprayed onto the core material while it is suspended by fluidized air; and the kneader coater method, in which the carrier core material and the coating layer forming solution are mixed in a kneader coater, and then the solvent is removed.

[0107] In a two-component developer, the mixing ratio (mass ratio) of green toner and carrier is preferably green toner:carrier = 1:100 to 30:100, and more preferably 3:100 to 20:100.

[0108] <Image forming device, image forming method> The image forming apparatus and image forming method according to this embodiment will be described below. The image forming apparatus according to this embodiment comprises 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, a developing means for containing an electrostatic image developer and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, a transfer means for transferring the toner image formed on the surface of the image holder to the surface of a recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic image developer according to this embodiment is applied as the electrostatic image developer.

[0109] The image forming apparatus according to this embodiment implements an image forming method (image forming method according to this embodiment) comprising: a charging step of charging the surface of an image holder; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image holder; a developing step of developing the electrostatic image formed on the surface of the image holder as a toner image using an electrostatic image developer according to this embodiment; a transfer step of transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0110] The image forming apparatus according to this embodiment may be any known image forming apparatus such as: a direct transfer apparatus that directly transfers a toner image formed on the surface of an image holder to a recording medium; an intermediate transfer apparatus that first transfers a toner image formed on the surface of an intermediate transfer body to the surface of an intermediate transfer body, and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; an apparatus equipped with cleaning means for cleaning the surface of the image holder before charging after the transfer of the toner image; or an apparatus equipped with static elimination means for irradiating the surface of the image holder with static elimination light before charging after the transfer of the toner image. In the case of an image forming apparatus of the present embodiment, if the image forming apparatus is an intermediate transfer type apparatus, the transfer means may include, for example, an intermediate transfer body on which a toner image is transferred; a primary transfer means for primaryly transferring the toner image formed on the surface of the image holder to the surface of the intermediate transfer body; and a secondary transfer means for secondary transferring the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

[0111] In the image forming apparatus according to this embodiment, for example, the part including the developing means may be a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge containing the electrostatic image developer according to this embodiment and equipped with a developing means is preferably used.

[0112] The following describes an example of an image forming apparatus according to this embodiment, but is not limited to this example. In the following description, only the main parts shown in the figures will be described, and other parts will be omitted.

[0113] In the following description, a six-unit tandem image forming apparatus, in which six image forming units are arranged in a row, will be described as an example of an image forming apparatus according to this embodiment. The tandem image forming apparatus is not limited to this, and may also be a five-unit tandem image forming apparatus, a four-unit tandem image forming apparatus, a four-unit tandem image forming apparatus, and so on.

[0114] Figure 1 is a schematic diagram showing an image forming apparatus according to this embodiment, and is a diagram showing an image forming apparatus with a 6-series tandem system and an intermediate transfer system. The image forming apparatus shown in Figure 1 includes first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, which are electrophotographic image forming means that output images of pink (P), yellow (Y), magenta (M), cyan (C), black (K), and green (G) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10P, 10Y, 10M, 10C, 10K, and 10G are arranged side by side at predetermined distances from each other in the horizontal direction. These units 10P, 10Y, 10M, 10C, 10K, and 10G may also be process cartridges that can be attached to and detached from the image forming apparatus.

[0115] An intermediate transfer belt (an example of an intermediate transfer body) 20 extends from below each unit 10P, 10Y, 10M, 10C, 10K, and 10G through each unit. The intermediate transfer belt 20 is wound around a drive roll 22, a support roll 23, and an opposing roll 24 that are in contact with the inner surface of the intermediate transfer belt 20, and is configured to travel in the direction from the first unit 10P to the sixth unit 10G. An intermediate transfer body cleaning device 21 is provided on the image holding surface side of the intermediate transfer belt 20, opposite the drive roll 22.

[0116] Each of the developing devices (examples of developing means) for each unit 10P, 10Y, 10M, 10C, 10K, and 10G, specifically 4P, 4Y, 4M, 4C, 4K, and 4G, is supplied with pink, yellow, magenta, cyan, black, and green toners contained in toner cartridges 8P, 8Y, 8M, 8C, 8K, and 8G.

[0117] Since the first to sixth units 10P, 10Y, 10M, 10C, 10K, and 10G have equivalent configurations and operations, the sixth unit 10G, which forms the green image, will be described as representative here.

[0118] The sixth unit 10G has a photoreceptor 1G that acts as an image holder. Around the photoreceptor 1G are, in order, a charging roll (an example of a charging means) 2G that charges the surface of the photoreceptor 1G to a predetermined potential, an exposure device (an example of a charge image forming means) 3G that exposes the charged surface with a laser beam based on a color-separated image signal to form a charge image, a developing device (an example of a developing means) 4G that supplies toner to the charge image to develop the charge image, 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 photoreceptor cleaning device (an example of a cleaning means) 6G that removes toner remaining on the surface of the photoreceptor 1G after primary transfer.

[0119] The primary transfer roll 5G is positioned inside the intermediate transfer belt 20, facing the photoreceptor 1G. Each primary transfer roll 5Y, 5P, 5M, 5C, 5G, and 5K of each unit is connected to a bias power supply (not shown) that applies the primary transfer bias. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll through control by a control unit (not shown).

[0120] The following describes the process of forming a green image in the 6th unit 10G. First, prior to operation, the surface of the photoreceptor 1G is charged to a potential of -600V to -800V by the charging roll 2G. Photoreceptor 1G is conductive (e.g., volume resistivity of 1 × 10 at 20°C). -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate (less than Ωcm). This photosensitive layer normally has high resistance (resistance of general resin), but when irradiated with a laser beam, the resistivity of the irradiated area changes. Therefore, a laser beam is irradiated from the exposure device 3G onto the surface of the charged photoreceptor 1G according to green image data sent from a control unit (not shown). As a result, an electrostatic image of the green image pattern is formed on the surface of the photoreceptor 1G.

[0121] An electrostatic image is an image formed on the surface of the photoreceptor 1G due to electrostatic charge. It is a so-called negative latent image formed when the resistivity of the irradiated portion of the photoreceptor decreases due to the laser beam from the exposure device 3G, causing the charged material on the surface of the photoreceptor 1G to flow, while the charge remains in the portion not irradiated by the laser beam. The electrostatic charge image formed on the photoreceptor 1G rotates to a predetermined development position as the photoreceptor 1G moves. At this development position, the electrostatic charge image on the photoreceptor 1G is developed as a toner image by the developing device 4G and made visible.

[0122] The developing device 4G contains, for example, an electrostatic image developer including at least green toner and a carrier. The green toner is triboelectrically charged by being agitated inside the developing device 4G and is held on the developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the static charge on the photoreceptor 1G. As the surface of the photoreceptor 1G passes through the developing device 4G, the green toner electrostatically adheres to the discharged latent image on the surface of the photoreceptor 1G, and the latent image is developed by the green toner. The photoreceptor 1G, on which the green toner image has been formed, continues to move at a predetermined speed, and the toner image developed on the photoreceptor 1G is transported to a predetermined primary transfer position.

[0123] When the green toner image on the photoreceptor 1G is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5G, and an electrostatic force acts on the toner image from the photoreceptor 1G to the primary transfer roll 5G, transferring the toner image on the photoreceptor 1G onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity opposite to the toner's polarity (-) (+), and in the first unit 10G, it is controlled by a control unit (not shown) to, for example, +10 μA.

[0124] After transferring the toner image to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with the cleaning blades of the photoreceptor cleaning device 6G. Any toner remaining on the photoreceptor 1G is removed and collected by the photoreceptor cleaning device 6G.

[0125] The intermediate transfer belt 20 is sequentially transported through the first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, and the toner images of each color are superimposed and transferred in multiple layers.

[0126] The intermediate transfer belt 20, on which six toner images have been multiple-transferred through the first to sixth units, proceeds to a secondary transfer section consisting of the intermediate transfer belt 20, a counter roll 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer means) 26 positioned on the image-holding surface side of the intermediate transfer belt 20. Meanwhile, recording paper (an example of a recording medium) P is fed via a supply mechanism into the gap between the secondary transfer roll 26 and the intermediate transfer belt 20 at a predetermined timing, and a secondary transfer bias is applied to the counter roll 24. The transfer bias applied at this time has the same polarity (-) as the toner's polarity (-), and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, transferring the toner image on the intermediate transfer belt 20 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.

[0127] After transferring the toner image to the recording paper P, the intermediate transfer belt 20 continues to move and comes into contact with the cleaning blades of the intermediate transfer body cleaning device 21. Any toner remaining on the intermediate transfer belt 20 is removed and collected by the intermediate transfer body cleaning device 21.

[0128] The recording paper P onto which the toner image has been transferred is fed to the contact area (nip area) of a pair of fixing rolls in a fixing device (an example of a fixing means) 28, where the toner image is fixed onto the recording paper P, and a fixed image is formed.

[0129] Examples of recording paper P used to transfer toner images include plain paper used in electrophotographic photocopiers and printers. Other recording media besides recording paper P include OHP sheets. 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, which is plain paper coated with resin or the like, or art paper for printing are preferably used.

[0130] Once the color image has been fixed onto the recording paper P, it is discharged towards the output section, and the series of color image formation operations is completed.

[0131] <Processor cartridges, toner cartridges> The process cartridge according to this embodiment will be described. The process cartridge according to this embodiment contains the electrostatic image developer according to this embodiment and includes a developing means for developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, and is a process cartridge that can be attached to and detached from an image forming apparatus.

[0132] The process cartridge according to this embodiment is not limited to the above configuration, and may also include a developing means and, as necessary, at least one other means selected from, for example, an image holder, a charging means, an electrostatic image forming means, and a transfer means.

[0133] An example of a process cartridge according to this embodiment is shown below, but it is not limited to this example. In the following description, only the main parts shown in the figure will be described, and other parts will be omitted from the description.

[0134] Figure 2 is a schematic diagram showing the process cartridge according to this embodiment. The process cartridge 200 shown in Figure 2 is constructed by integrally holding a photoreceptor 107 (an example of an image holder), a charging roll 108 (an example of a charging means) provided around the photoreceptor 107, a developing device 111 (an example of a developing means), and a photoreceptor cleaning device 113 (an example of a cleaning means) within a housing 117 equipped with a mounting rail 116 and an opening 118 for exposure, and is then formed into a cartridge. In Figure 2, 109 is an exposure apparatus (an example of electrostatic image formation means), 112 is a transfer apparatus (an example of a transfer means), 115 is a fixing apparatus (an example of a fixing means), and 300 is recording paper (an example of a recording medium).

[0135] Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to this embodiment is a toner cartridge that contains the fluorescent green toner according to this embodiment and is attached to and detached from an image forming apparatus. The toner cartridge contains replenishment toner for supply to the developing means provided in the image forming apparatus.

[0136] The image forming apparatus shown in Figure 1 is configured to allow the attachment and detachment of toner cartridges 8Y, 8P, 8M, 8C, 8G, and 8K. The developing units 4Y, 4P, 4M, 4C, 4G, and 4K are connected to toner cartridges corresponding to their respective colors by toner supply pipes (not shown). When the toner contained in a toner cartridge becomes low, the toner cartridge is replaced. An example of a toner cartridge according to this embodiment is toner cartridge 8G, which contains the green toner according to this embodiment. Toner cartridges 8P, 8Y, 8M, 8C, and 8K contain pink, yellow, magenta, cyan, and black toners, respectively. [Examples]

[0137] The embodiments of the invention will be described in detail below with reference to examples, but the embodiments of the invention are not limited to these examples. In the following explanation, unless otherwise specified, "parts" and "%" refer to mass. Synthesis, processing, and manufacturing were carried out at room temperature (25°C ± 3°C) unless otherwise specified.

[0138] <Preparation of colorant particle dispersion (1)> • Fluorescent yellow pigment (CI Pigment Yellow 101 (Radiant Color, Radglo VSF-0-01)): 70 units • Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts (solid content concentration 20%) • Ion-exchanged water: 200 bottles The above components were mixed and ground to 0.3 μm using a continuous key mill (KMC-3), and the solid content was adjusted to 20% by mass to obtain a coloring agent particle dispersion (1).

[0139] <Preparation of coloring agent particle dispersion (2)> • Non-fluorescent green pigment (CI Pigment Green 36 (manufactured by Toyo Color Co., Ltd., LIONOL GREEN 8624)): 70 units • Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts (solid content concentration 20%) • Ion-exchanged water: 200 bottles The above components were mixed and ground to 0.15 μm using a continuous key mill (KMC-3), and the solid content was adjusted to 20% by mass to obtain a coloring agent particle dispersion (2).

[0140] <Preparation of resin particle dispersion (1)> Terephthalic acid: 30 moles Fumaric acid: 70 moles • Bisphenol A ethylene oxide adduct: 5 moles • Bisphenol A propylene oxide adduct: 95 moles The above materials were placed in a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectification column, and the temperature was raised to 220°C over 1 hour. One part titanium tetraethoxide was added for every 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 this temperature for 1 hour. After that, the reactants were cooled. In this way, a polyester resin with a weight-average molecular weight of 18,000 and a glass transition temperature of 60°C was obtained. In a container equipped with temperature control and nitrogen purging means, 40 parts of ethyl acetate and 25 parts of 2-butanol were added to form a mixed solvent. Then, 100 parts of polyester resin were gradually added and dissolved. A 10% by mass aqueous ammonia solution (equivalent to 3 times the molar ratio of the acid value of the resin) was added and stirred for 30 minutes. Next, the container was purged with dry nitrogen, and the temperature was maintained at 40°C. While stirring the mixture, 400 parts of deionized water were added dropwise at a rate of 2 parts / minute. After the dropwise addition was complete, the mixture was returned to room temperature (20°C to 25°C), and while stirring, it was bubbled with dry nitrogen for 48 hours to obtain a resin particle dispersion in which the ethyl acetate and 2-butanol were reduced to 1,000 ppm or less. Deionized water was added to the resin particle dispersion to adjust the solid content to 20% by mass to obtain resin particle dispersion (1).

[0141] <Preparation of mold release agent particle dispersion (1)> • Paraffin wax (manufactured by Nippon Seiro Co., Ltd., HNP-9): 100 units • Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part • Ion-exchanged water: 350 units The above materials were mixed and heated to 100°C, dispersed using a homogenizer (IKA Corporation, product name Ultra-Turrax T50), and then dispersed again using a Manton-Gorin high-pressure homogenizer (Gorin Corporation) to obtain a release agent particle dispersion (1) (solid content 20% by mass) containing release agent particles with a volume average particle size of 200 nm.

[0142] <Preparation of toner particles (1)> ·Resin particle dispersion (1): 340 parts • Coloring agent particle dispersion (1): 40 parts • Coloring agent particle dispersion (2): 20 parts • Release agent particle dispersion (1): 50 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 0.1 N (= mol / L) nitric acid was added to adjust the pH to 3.5. Then, 30 parts of a 10% by mass nitric acid aqueous solution containing aluminum chloride were added. Next, the mixture was dispersed at a liquid temperature of 30°C using a homogenizer (IKA Corporation, product name Ultra-Turrax T50), and then heated to 45°C in a heating oil bath and held for 30 minutes. After that, 50 parts of the resin particle dispersion (1) were added and held for 1 hour, and then a 0.1 N sodium hydroxide aqueous solution was added to adjust the pH to 8.5. After that, it was heated to 84°C and held for 2.5 hours. Next, it was cooled to 20°C at a rate of 20°C / min, the solid components were filtered off, thoroughly washed with deionized water, and dried to obtain toner particles (1). The volume-average particle size of the toner particles (1) was 5.8 μm.

[0143] <Creating 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, volume resistivity: 100 Ωcm or less) The above materials, excluding the ferrite particles, were dispersed in a sand mill to prepare a dispersion. This dispersion was then placed together with the ferrite particles in a vacuum-degassed kneader and dried under reduced pressure while stirring to obtain carrier 1.

[0144] <Toner production> To 100 parts by mass of the obtained toner particles (1), 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) were mixed and blended using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. Subsequently, the mixture was sieved using a vibrating sieve with a mesh size of 45 μm to prepare toner 1 (fluorescent green toner). The volume-average particle size of the obtained toner 1 was 5.8 μm.

[0145] <Preparation of electrostatic image developer> Eight parts toner and ninety-two parts carrier were mixed in a V-blender to prepare developer 1 (electrostatic image developer).

[0146] [Evaluation (gloss step suppression, brightness, and saturation)] A modified Revoria Press PC1120 image forming machine manufactured by Fujifilm Business Innovation Co., Ltd. was prepared, and each of the six developing units was filled with Fujifilm Business Innovation Co., Ltd.'s pink, yellow, magenta, cyan, black, and green developer 1. Under conditions of 22°C and 55% RH humidity, 100 blank images with 0% image density were printed on OS coated paper (manufactured by Oji Paper Co., Ltd., product name: OS Coat 127). Subsequently, the Electronic Photography Society Digital Chart No. 7 was printed on OS coated paper (manufactured by Oji Paper Co., Ltd., product name: OS Coat 127) with 100% image density (toner load of 4.0 g / m² for each color). 2 Print one sheet using ) and then print on OS coated paper (manufactured by Oji Paper Co., Ltd., product name: OS Coat 127) at 100% image density (toner load 4.0 g / m²). 2 A solid image of fluorescent green toner obtained using the method described above was printed. The gloss of the obtained solid image was measured in the image history area and the non-image history area of ​​the previously printed Digital Chart No. 7. Gloss was measured using a portable gloss meter (BYK Gardner Microtrigloss), with 60-degree gloss measurements taken at five locations and averaged. The difference between the gloss measurements of the image history area and the non-image history area was calculated and evaluated according to the following evaluation criteria. G1: The maximum gross difference between the image history section and the non-image history section is less than 1. G2: The maximum gross difference between the image history section and the non-image history section is between 1 and 3. G3: The maximum gross difference between the image history section and the non-image history section is between 3 and 5. G4: The maximum gross difference between the image history section and the non-image history section is 5 or more.

[0147] Furthermore, using a reflectance spectrodensitometer X-Rite939 (aperture diameter 4 mm, X-Rite Corporation), CIE1976L was detected at 10 locations within the solid image. * a *b * L in color systems * value, a * Value and b * Measure the value, L * value, a * Value and b * The average value was calculated. Furthermore, the saturation C was calculated using the following formula. * The following was calculated: Brightness L * It is preferable that the saturation is 70 or higher, C * A value of 85 or higher is preferable. Saturation C * ={(a * ) 2 +(b * ) 2} 0.5

[0148] <Examples 2 to 4> Except for changing the types and contents of the fluorescent pigment, non-fluorescent pigment, and release agent as shown in Table 1, toner was prepared in the same manner as in Example 1, and then a developer was obtained and evaluated in the same manner.

[0149] <Example 5> In preparing the toner particles, the toner was prepared in the same manner as in Example 1, except that it was heated to 84°C and held for 2.5 hours, then cooled to 80°C over 20 minutes, and then cooled to 20°C at a rate of 20°C / min. After obtaining the developer, the evaluation was carried out in the same manner.

[0150] <Examples 6 to 9> Except for changing the types and contents of the fluorescent pigment, non-fluorescent pigment, and release agent as shown in Table 1, toner was prepared in the same manner as in Example 1, and then a developer was obtained and evaluated in the same manner.

[0151] <Example 10> In preparing the toner particles, the toner was prepared in the same manner as in Example 1, except that it was heated to 84°C and held for 2.5 hours, then cooled to 80°C over 30 minutes, and then cooled to 20°C at a rate of 20°C / min. After obtaining the developer, the evaluation was carried out in the same manner.

[0152] <Example 11> Toner particles were prepared using the following kneading and grinding method. Amorphous polyester resin (weight-average molecular weight 18,000, glass transition temperature 60°C): 155.4 parts CI Pigment Yellow 101: 16 parts CI Pigment Green 36:8 parts Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 20.6 parts The above materials were placed in a Henschel mixer (FM75L, Nippon Coke Industries Co., Ltd.) and mixed at a rotation speed of 20 rpm for 15 minutes to obtain a toner composition. Next, the mixture was kneaded in a twin-screw extruder (TEM-48SS, Shibaura Machinery Co., Ltd.) set to a temperature of 150°C, rolled, and cooled to below 30°C. The obtained mixture was coarsely ground to less than 1 mm in a hammer mill and finely ground in a jet mill (AFG, Hosokawa Micron Corporation). Classification was performed in an elbow jet classifier (EJ-LABO, Nippon Steel Mining Co., Ltd.) to obtain green toner particles with a volume average particle size of 6.5 μm. Thereafter, toner was prepared in the same manner as in Example 1, and after obtaining a developer, evaluation was carried out in the same manner.

[0153] <Comparative Example 1 and Comparative Example 2> Except for changing the non-fluorescent pigment as shown in Table 1, toner was prepared in the same manner as in Example 1, and then a developer was obtained and evaluated in the same manner.

[0154] I have confirmed it. <Examples 12 to 21> Except for changing the types and contents of the fluorescent pigment, non-fluorescent pigment, and release agent as shown in Table 1, toner was prepared in the same manner as in Example 1, and then a developer was obtained and evaluated in the same manner.

[0155] [Table 1]

[0156] In Table 1, the domain diameter ratio of the release agent represents the ratio of the domain diameter of the release agent to the volume-average particle size of the toner particles, and the release agent content represents the content of the release agent relative to the total mass of the toner particles.

[0157] The symbols in Table 1 represent the following pigments or dyes. • PY101: CI Pigment Yellow 101 (Radiant Color, Radglo VSF-0-01, emission peak wavelength 520nm), azomethine fluorescent pigment with hydroxyl groups. • Azomethine compound (3): The aforementioned azomethine compound (3) (Note: Azomethine compound (3) was prepared by the method described below), an azomethine fluorescent pigment with an emission peak wavelength of 520 nm and a hydroxyl group. PG36: CI Pigment Green 36 (manufactured by Toyo Color Co., Ltd., LIONOL GREEN 8624, hue: yellowish green), copper phthalocyanine nonfluorescent pigment containing chlorine and bromine atoms. • PG7: CI Pigment Green 7 (manufactured by Toyo Color Co., Ltd., LIONOL GREEN 8390, hue: bluish green), copper phthalocyanine nonfluorescent pigment containing chlorine atoms. • PG10: CI Pigment Green 10 (BASF, Paliotol Yellow L-0830, Hue: Yellowish Green), azomethine nonfluorescent pigment containing chlorine atoms. • PG1: CI Pigment Green 1 (BASF, Fanal Green D 8330, Hue: Bluish Green), a dye lake pigment without halogen atoms. • PB15:3:CI Pigment Blue 15:3 (manufactured by Toyo Color Co., Ltd., LIONOL BLUE FG-7330, hue: blue), a non-fluorescent copper phthalocyanine pigment without halogen atoms. • Polyethylene: Polyethylene wax (manufactured by Toyo Adore Co., Ltd., PW725) • Ester: Ester wax (manufactured by NOF Corporation, WEP-5)

[0158] <Preparation of azomethine compound (3)> • Hydrazine hydrate: 100 moles • Salicylaldehyde: 200 moles Ethanol and the above materials were charged into a flask equipped with a stirring device, and the mixture was heated under reflux for 1 hour while distilling off the water produced in a water bath, after which the reaction product was cooled. The precipitated solid was collected by suction filtration to obtain azomethine compound (3).

[0159] (Example 101) <Image formation using actual equipment> A six-tandem electrophotographic and intermediate transfer image forming apparatus was prepared. Each of the six developing units was filled with a pink developer, a yellow developer, a magenta developer, a cyan developer, a black developer, and a green developer (the developer from Example 1). Then, based on the image data obtained by color-separating RGB data into the six colors described above, an image was formed on A4-sized coated paper. An image with good color reproduction close to the original RGB data was obtained.

[0160] (((1))) Fluorescent green toner containing toner particles containing a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment having halogen atoms. (((2))) The fluorescent green toner according to (((1))), wherein the pigment having the halogen atom is a phthalocyanine compound. (((3))) The fluorescent green toner according to (((1))) or (((2))) wherein the pigment having the halogen atom has at least one selected from the group consisting of chlorine atoms and bromine atoms as the halogen atom. (((4))) The fluorescent green toner according to any one of (((1))) to (((3))), wherein the pigment having halogen atoms has four or more halogen atoms. (((5))) The fluorescent green toner according to (((4))), wherein the pigment having halogen atoms has eight or more halogen atoms. (((6))) The fluorescent green toner according to any one of (((1))) to (((5))) wherein the fluorescent pigment having a hydrophilic group has a hydroxyl group as the hydrophilic group. (((7))) The fluorescent green toner according to (((6))), wherein the ratio of the molecular weight of the hydroxyl group to the total molecular weight of one molecule of the hydrophilic fluorescent pigment is 12% by mass or less. (((8))) The fluorescent green toner according to any one of (((1))) to (((7))) wherein the fluorescent pigment having a hydrophilic group is an azomethine compound. (((9))) The fluorescent green toner according to any one of (((1))) to (((8))), wherein the release agent is 2% by mass or more and 20% by mass or less with respect to the total mass of the toner particles. (((10))) The fluorescent green toner according to any one of (((1))) to (((9))) wherein the mold release agent is paraffin wax or polyethylene wax. (((1))) The fluorescent green toner according to any one of (((1))) to (((10))), wherein the domain diameter of the release agent in the toner particles is 25% or less of the volume average particle size of the toner particles. (((12))) The fluorescent green toner according to any one of (((1))) to (((11))) wherein the toner particles have a core-shell structure. A electrostatic image developer containing the fluorescent green toner described in any one of (((13))) (((1))) to (((12))). A toner cartridge that contains the fluorescent green toner described in any one of (((14))) (((1))) to (((12))) and is attached to and detached from an image forming apparatus. A process cartridge that contains the electrostatic image developer described in (((15))) (((13))), and comprises a developing means for developing an electrostatic image formed on the surface of an image holder as a toner image using the electrostatic image developer, and is attached to and detached from an image forming apparatus. (((16))) An image forming apparatus comprising: an image holder; charging means for charging the surface of the image holder; electrostatic image forming means for forming an electrostatic image on the charged surface of the image holder; developing means for containing the electrostatic image developer described in (((13))) and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer; transfer means for transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and fixing means for fixing the toner image transferred to the surface of the recording medium. (((17))) An image forming method comprising: a charging step of charging the surface of an image holder; a static charge image forming step of forming a static charge image on the charged surface of the image holder; a developing step of developing the static charge image formed on the surface of the image holder as a toner image using the static charge image developer described in (((13))); a transfer step of transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium. (((18))) An image forming apparatus comprising first to sixth electrophotographic image forming units that form images of pink, yellow, magenta, cyan, black, and green, wherein the image forming unit that forms the green image contains the electrostatic image developer described in (((13))). (((19))) An image forming method comprising first to sixth electrophotographic image forming steps for forming images of pink, yellow, magenta, cyan, black, and green, wherein the image forming step for forming the green image uses the electrostatic image developer described in (((13))).

[0161] According to the invention of (((1))) or (((12))), a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the toner particles contain a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment that does not have halogen atoms. According to the invention of (((2))), a fluorescent green toner is provided that is superior in suppressing gloss steps in the resulting image compared to a case where the pigment having the halogen atom is an azomethine pigment other than a phthalocyanine compound. According to the invention of (((3))), a fluorescent green toner is provided that has superior gloss step suppression in the resulting image compared to the case in which the pigment having halogen atoms has only fluorine atoms or elemental atoms as halogen atoms. According to the invention of (((4))), a fluorescent green toner is provided that has superior gloss step suppression in the resulting image compared to the case in which the pigment having halogen atoms has fewer than four halogen atoms. According to the invention of (((5))), a fluorescent green toner is provided that has superior gloss step suppression in the resulting image compared to the case in which the pigment having halogen atoms has fewer than eight halogen atoms. According to the invention of (((6))), a fluorescent green toner is provided that has superior gloss step suppression in the resulting image compared to the case in which the hydrophilic group-containing fluorescent pigment has only a carboxyl group as the hydrophilic group. According to the invention of (((7))), a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to the case where the ratio of the molecular weight of the hydroxyl group to the total molecular weight of one molecule of the hydrophilic fluorescent pigment exceeds 12% by mass. According to the invention of (((8))), a fluorescent green toner is provided that is superior in suppressing gloss steps in the resulting image compared to the case where the fluorescent pigment having a hydrophilic group is a triphenylmethane compound. According to the invention of (((9))), a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to cases where the release agent is less than 2% by mass or more than 20% by mass of the total mass of the toner particles. According to the invention of (((10))), a fluorescent green toner is provided that is superior in suppressing gloss steps in the resulting image compared to when the release agent is an ester wax. According to the invention of (((11))), a fluorescent green toner is provided that exhibits superior gloss step suppression in the resulting image compared to a case where the domain diameter of the release agent in the toner particles is greater than 25% of the volume-average particle size of the toner particles. According to the inventions of (((13))), (((14))), (((15))), (((16))), (((17))), (((18))), or (((19))), an electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, or image forming method is provided that exhibits superior gloss step suppression in the resulting image compared to cases where the toner particles in the fluorescent green toner contain a binder resin, a release agent, a fluorescent pigment having hydrophilic groups, and a pigment without halogen atoms. [Explanation of Symbols]

[0162] 1P, 1Y, 1M, 1C, 1K, 1G Photoreceptor (an example of an image retainer) 2P, 2Y, 2M, 2C, 2K, 2G Charging Rolls (Example of Charging Method) 3P, 3Y, 3M, 3C, 3K, 3G exposure equipment (an example of electrostatic image forming means) 4P, 4Y, 4M, 4C, 4K, 4G developing device (an example of a developing method) 5P, 5Y, 5M, 5C, 5K, 5G Primary transfer rolls (an example of a primary transfer method) 6P, 6Y, 6M, 6C, 6K, 6G Photoconductor Cleaning Device (Example of Cleaning Method) 8P, 8Y, 8M, 8C, 8K, 8G Toner Cartridges 10P, 10Y, 10M, 10C, 10K, 10G Image Forming Units 20. Intermediate transfer belt (an example of an intermediate transfer material) 21 Intermediate Transfer Body Cleaning Apparatus 22 Drive 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)

[0163] 107 Photoreceptor (an example of an image-retaining element) 108 Charging Roll (Example of Charging Method) 109 Exposure apparatus (an example of a means for forming electrostatic images) 111 Developing apparatus (an example of a developing means) 112 Transfer device (an example of a transfer means) 113 Photoreceptor cleaning device (an example of a cleaning method) 115 Fixing device (an example of a fixing means) 116 Mounting Rail 117 cabinets 118 Aperture for exposure 200 Process Cartridges 300 Recording paper (an example of a recording medium)

Claims

1. Binding resin, Release agent, A fluorescent pigment having a hydrophilic group, and Pigments containing halogen atoms Contains toner particles containing The total content of the fluorescent pigment having a hydrophilic group and the pigment having a halogen atom relative to the entire toner particle is 8% by mass or more and 20% by mass or less. Fluorescent green toner.

2. The fluorescent green toner according to claim 1, wherein the pigment having the halogen atom is a phthalocyanine compound.

3. The fluorescent green toner according to claim 1, wherein the pigment having the halogen atom has at least one selected from the group consisting of chlorine atoms and bromine atoms as the halogen atom.

4. The fluorescent green toner according to claim 1, wherein the pigment having halogen atoms has four or more halogen atoms.

5. The fluorescent green toner according to claim 4, wherein the pigment having halogen atoms has eight or more halogen atoms.

6. The fluorescent green toner according to claim 1, wherein the fluorescent pigment having a hydrophilic group has a hydroxyl group as the hydrophilic group.

7. The fluorescent green toner according to claim 6, wherein the ratio of the molecular weight of the hydroxyl group to the total molecular weight of one molecule of the hydrophilic fluorescent pigment is 12% by mass or less.

8. The fluorescent green toner according to claim 1, wherein the fluorescent pigment having a hydrophilic group is an azomethine compound.

9. The fluorescent green toner according to claim 1, wherein the release agent is 2% by mass or more and 20% by mass or less with respect to the total mass of the toner particles.

10. The fluorescent green toner according to claim 1, wherein the mold release agent is paraffin wax or polyethylene wax.

11. The fluorescent green toner according to claim 1, wherein the domain diameter of the release agent in the toner particles is 25% or less of the volume-average particle size of the toner particles.

12. The fluorescent green toner according to claim 1, wherein the toner particles have a core-shell structure.

13. A electrostatic image developer comprising the fluorescent green toner according to any one of claims 1 to 12.

14. A toner cartridge containing the fluorescent green toner described in any one of claims 1 to 12, which is attached to and detached from an image forming apparatus.

15. A process cartridge that contains the electrostatic image developer described in claim 13, and comprises a developing means for developing an electrostatic image formed on the surface of an image holder as a toner image using the electrostatic image developer, and is detachable from an image forming apparatus.

16. Image holder and, A charging means for charging the surface of the image holder, A means for forming an electrostatic image on the surface of the charged image holder, A developing means comprising: containing the electrostatic image developer described in claim 13; and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer; A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus equipped with the following features.

17. A charging step in which the surface of the image holder is charged, A step of forming an electrostatic image on the surface of the charged image holder, A developing step of developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer described in claim 13, A transfer step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium, A fixing step for fixing the toner image transferred to the surface of the recording medium, An image forming method having the following characteristics.

18. It comprises first to sixth image forming units of an electrophotographic method that form images of pink, yellow, magenta, cyan, black, and green, The image forming unit that forms the green image contains the electrostatic image developer described in claim 13. Image forming apparatus.

19. The system has first to sixth image forming steps using an electrophotographic method to form images of pink, yellow, magenta, cyan, black, and green. The image forming step for forming the green image uses the electrostatic image developer described in claim 13. Image forming method.

Images