Photoluminescent toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus and image forming method

Abstract

To provide a photoluminescent toner that reduces the likelihood of the occurrence of uneven glossiness of a fixed image caused by scratches in a surface of a fixing member.SOLUTION: A photoluminescent toner includes a photoluminescent toner containing a binder resin, a mold release agent, and a photoluminescent pigment and having mold release agent domains, and a silicone oil-treated silica particle externally added to the photoluminescent toner particle. In observation of the cross section of the photoluminescent toner, the average major axis length Dw of the mold release agent domains and the average major axis length Dp of the photoluminescent pigment satisfy the formula (1). Formula (1): 0.3≤Dw / Dp≤1.0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a photoluminescent 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 glitter toner containing glitter toner particles that contain a glitter pigment and a release agent, in which the length of the long axis direction of the release agent domain is 300 nm or more and 1500 nm or less, and the ratio of the length of the long axis direction to the length of the short axis direction of the release agent domain is 3.0 or more and 15.0 or less. Patent Document 2 discloses a toner that includes a binder resin, a colorant, and a release agent, and in which, when a cross section of the toner before fixing is observed, the release agent has flat domains, the major axis of the domain diameter of the release agent is 0.6 μm or more, and the ratio of the major axis to the minor axis of the domain diameter of the release agent is 2.0 or more, and in which, when a cross section of an image after fixing is observed, the domain diameter of the release agent is 0.5 μm or less. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-142401 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-169899 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a glitter toner that is less likely to cause uneven gloss in fixed images due to scratches on the fixing member surface, compared to a glitter toner in which the average major axis length Dw of the release agent domains and the average major axis length Dp of the glitter pigment do not satisfy formula (1) or a glitter toner to which silicone oil-treated silica particles are not externally added, where formula (1): 0.3≦Dw / Dp≦1.0. [Means for solving the problem]

[0005] The means for solving the above problems include the following aspects.

[0006] <1> A lustrous toner comprising: glittering toner particles containing a binder resin, a release agent, and a glittering pigment and having a release agent domain; and silicone oil-treated silica particles externally added to the glittering toner particles, wherein, upon cross-sectional observation of the glittering toner particles, the average major axis length Dw of the release agent domains and the average major axis length Dp of the glittering pigment satisfy the following formula (1): Formula (1): 0.3≦Dw / Dp≦1.0 <2> In a cross-sectional observation of the glitter toner particle, the average major axis length Dw of the release agent domain and the average major axis length Dp of the glitter pigment satisfy the following formula (1-1): <1> The glitter toner according to claim 1. Formula (1-1): 0.3≦Dw / Dp≦0.8 <3> When a cross section of the glitter toner particle is observed, the average aspect ratio (average of major axis length / minor axis length) of the release agent domain is 1.00 or more and 1.40 or less. <1> or <2> The glitter toner according to claim 1. <4> When a cross section of the glitter toner particle is observed, the average aspect ratio (average of major axis length / minor axis length) of the release agent domain is 1.00 or more and 1.25 or less. <1> ~ <3> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <5> When a cross section of the glitter toner particle is observed, the area of the release agent domain contained in a surface layer portion from the surface of the glitter toner particle to a depth of 1 μm is 50% or more and 100% or less of the total area of the release agent domain contained in the glitter toner particle. <1> ~ <4> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <6> When a cross section of the glitter toner particle is observed, the area of the release agent domain contained in a surface layer portion from the surface of the glitter toner particle to a depth of 1 μm is 70% or more and 100% or less of the total area of the release agent domain contained in the glitter toner particle. <1> ~ <5> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <7> The silicone oil-treated silica particles have an average primary particle size of 40 nm or more and 140 nm or less. <1> ~ <6> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <8> the mass ratio (free oil / releasing agent) of the amount of the releasing agent contained in the glitter toner particles to the amount of free oil present in the glitter toner is 0.03 or more and 2.00 or less; <1> ~ <7> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <9> When a cross section of the glitter toner particle is observed, the average major axis length Dw of the release agent domain is 0.3 μm or more and 2.0 μm or less. <1> ~ <8> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <10> When differential scanning calorimetry is performed, at least one endothermic peak is observed in the temperature range of 80°C to 100°C. <1> ~ <9> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <11> The release agent comprises an ester wax. <1> ~ <10> 10. The glitter toner according to claim 1, wherein the toner is a toner having a glossy finish. <12> <1> ~ <11> 10. An electrostatic image developer comprising the photoluminescent toner according to any one of claims 1 to 9. <13> <1> ~ <11> 10. A toner cartridge containing the glitter toner according to any one of claims 1 to 9, which is detachably mounted on an image forming apparatus. <14> <12> and a developing means for developing an electrostatic image formed on the surface of an image carrier using the electrostatic image developer into a toner image, the process cartridge being detachably mountable to an image forming apparatus. <15> an image carrier; a charging means for charging the surface of the image carrier; an electrostatic image forming means for forming an electrostatic image on the charged surface of the image carrier; <12> a developing means for developing the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer; a transfer means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing means for fixing the toner image transferred onto the surface of the recording medium; An image forming apparatus comprising: <16> a charging step of charging the surface of the image carrier; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier; <12> a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer according to claim 1; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing step of fixing the toner image transferred onto the surface of the recording medium; An image forming method comprising the steps of: [Effects of the Invention]

[0007] <1> , <8> , <9> , <10> or <11> According to the present invention, a glossy toner is provided that is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to a glossy toner that does not satisfy formula (1) or a glossy toner that does not have silicone oil-treated silica particles added externally. <2> According to the invention relating to (1), a glitter toner is provided which is less likely to cause uneven gloss in a fixed image due to scratches on the surface of a fixing member, compared to glitter toners that do not satisfy formula (1-1). <3> or <4> According to the present invention, a glossy toner is provided that is less likely to cause uneven gloss in fixed images due to scratches on the surface of the fixing member, compared to glossy toners in which the average aspect ratio (average of major axis length / minor axis length) of the release agent domains is less than 1.00 or more than 1.40. <5> or <6> According to the invention, a glossy toner is provided that is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to a glossy toner in which the area of the release agent domain contained in the surface layer of the glossy toner particle up to a depth of 1 μm from the surface of the glossy toner particle is less than 50% of the total area of the release agent domain contained in the glossy toner particle. <7> According to the present invention, a glitter toner is provided which is less likely to cause uneven gloss in fixed images due to scratches on the surface of the fixing member, compared to a glitter toner in which the average primary particle size of silicone oil-treated silica particles exceeds 140 nm.

[0008] <12> According to the invention, an electrostatic image developer is provided which is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to an electrostatic image developer using a glossy toner that does not satisfy formula (1) or a glossy toner that does not have silicone oil-treated silica particles externally added. <13> According to the invention, a toner cartridge is provided which is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to a toner cartridge using a glossy toner that does not satisfy formula (1) or a glossy toner that does not have silicone oil-treated silica particles added externally. <14> According to the invention, a process cartridge is provided which is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to a process cartridge using a glossy toner that does not satisfy formula (1) or a glossy toner that does not have silicone oil-treated silica particles added externally. <15> According to the invention, an image forming apparatus is provided which is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to an image forming apparatus which uses a glossy toner that does not satisfy formula (1) or a glossy toner to which silicone oil-treated silica particles are not externally added. <16> According to the present invention, an image forming method is provided which is less likely to cause uneven gloss in the fixed image due to scratches on the surface of the fixing member, compared to an image forming method using a glossy toner that does not satisfy formula (1) or a glossy toner that does not have silicone oil-treated silica particles added externally. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating an example of a process cartridge that is detachably mounted to an image forming apparatus according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0011] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0012] In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved.

[0013] When the present disclosure describes an embodiment with reference to drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of components in each drawing are conceptual, and the relative size relationships between components are not limited to these.

[0014] In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In the present disclosure, the composition may contain multiple types of particles corresponding to each component. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0015] In the present disclosure, "(meth)acrylic" is an expression that includes both acrylic and methacrylic, and "(meth)acrylate" is an expression that includes both acrylate and methacrylate.

[0016] In this disclosure, "toner for developing electrostatic images" is also referred to as "toner," "carrier for developing electrostatic images" is also referred to as "carrier," and "electrostatic image developer" is also referred to as "developer."

[0017] <Brilliant toner> The glitter toner according to this embodiment includes glitter toner particles that contain a binder resin, a release agent, and a glitter pigment and have a release agent domain, and silicone oil-treated silica particles that are externally added to the glitter toner particles. In the glitter toner according to this embodiment, when a cross section of a glitter toner particle is observed, the average major axis length Dw of the release agent domain and the average major axis length Dp of the glitter pigment satisfy the following formula (1). Formula (1): 0.3≦Dw / Dp≦1.0

[0018] The glitter toner according to this embodiment is less likely to cause uneven gloss in a fixed image due to scratches on the surface of the fixing member. The mechanism behind this is presumed to be as follows.

[0019] The glitter toner contains a glitter pigment in the toner particles. The glitter pigment is a hard pigment and may damage the surface of the fixing member. Friction between the recording medium and the transport member easily causes the recording medium to become statically charged, resulting in a potential difference between the recording medium and the fixing member. The potential difference generated in the fixing section causes the glitter toner to rise along the long axis of the glitter pigment, easily damaging the surface of the fixing member. This phenomenon is particularly pronounced when continuous image formation is performed on coated paper at relatively high speed in a low-temperature, low-humidity environment (e.g., a temperature of 10°C and a relative humidity of 10%), as static electricity is likely to be generated between the recording medium and the recording medium transport member. A fixing member with a damaged surface will cause uneven gloss in the fixed image.

[0020] In response to the above phenomenon, the present inventors have discovered that a glitter toner that combines glitter toner particles that satisfy formula (1) with silicone oil-treated silica particles as an external additive is less likely to cause scratches on the surface of a fixing member. Even if the glitter toner stands up along the long axis of the glitter pigment on a recording medium, it will slide down during image fixing, making it less likely to damage the surface of the fixing member.

[0021] Formula (1) specifies that the ratio Dw / Dp of the average major axis length Dw of the release agent domains to the average major axis length Dp of the effective pigment is 0.3 or more and 1.0 or less. If the ratio Dw / Dp is 1.0 or less, the release agent domains are crushed by the bright pigment during image fixing, and the release agent is likely to seep out of the bright toner particles.If the ratio Dw / Dp is more than 1.0, the release agent domains are too large compared to the bright pigment, and the release agent domains are not sufficiently crushed during image fixing. On the other hand, if the ratio Dw / Dp is less than 0.3, the luster pigment prevents the release agent from seeping out of the luster toner particles. From the above viewpoint, the formula (1) is preferably the following formula (1-1). Formula (1-1): 0.3≦Dw / Dp≦0.8

[0022] The release agent that seeps out of the glittering toner particles during image fixing comes into contact with the silicone oil-treated silica, mixes with the silicone oil, and thickens, and an appropriate amount of the release agent mixed with the silicone oil remains in the nip of the fixing member. Although the detailed mechanism is unclear, with external additives other than silicone oil-treated silica, it is difficult to expect the release agent to thicken and remain in the nip.

[0023] In the glitter toner according to this embodiment, the shape of the release agent domains is preferably close to spherical, since the release agent domains are easily crushed during image fixation. Therefore, when observing the cross section of a glitter toner particle, the average aspect ratio of the release agent domains is preferably 1.00 or more and 1.40 or less, more preferably 1.00 or more and 1.25 or less, and even more preferably 1.00 or more and 1.18 or less.

[0024] In the case of the glossy toner according to this embodiment, from the viewpoint that the release agent easily seeps out of the glossy toner particles during image fixation, when a cross-section of a glossy toner particle is observed, the area of the release agent domain contained in the surface layer portion from the surface of the glossy toner particle to a depth of 1 μm is preferably 50% or more and 100% or less, more preferably 60% or more and 100% or less, and even more preferably 70% or more and 100% or less of the total area of the release agent domain contained in the glossy toner particle.

[0025] In the glitter toner according to this embodiment, from the viewpoint that the release agent easily seeps out of the glitter toner particles during image fixation, when a cross section of the glitter toner particle is observed, the average major axis length Dw of the release agent domains is preferably 0.3 μm or more and 2.0 μm or less, more preferably 0.5 μm or more and 1.5 μm or less, and even more preferably 0.5 μm or more and 1.2 μm or less.

[0026] In the glitter toner according to this embodiment, from the viewpoint of achieving a balance between crushing the release agent domains during image fixation and being less likely to damage the fixing member, when a cross-section of a glitter toner particle is observed, the average major axis length Dp of the glitter pigment is preferably 0.5 μm or more and 10.0 μm or less, more preferably 0.5 μm or more and 8.0 μm or less, and even more preferably 0.5 μm or more and 6.5 μm or less.

[0027] The method for observing the cross section of the glitter toner particles and the method for measuring the geometrical quantities will be described below.

[0028] Photoluminescent toner particles (which may contain external additives) are embedded in bisphenol A liquid epoxy resin and a curing agent to prepare a cutting sample. The cutting sample is then cut at -100°C using a cutting machine equipped with a diamond knife (e.g., a LEICA Ultramicrotome, manufactured by Hitachi High-Technologies Corporation) to prepare a sample for observation. If necessary, the observation sample is left in a desiccator in an atmosphere of ruthenium tetroxide and stained. The sample is observed under a scanning transmission electron microscope (STEM), and a STEM image is recorded at a magnification that allows the cross section of a single photoluminescent toner particle to be viewed. The recorded STEM image is analyzed using image analysis software (e.g., WinROOF2015, Mitani Corporation) under conditions of 0.010 μm / pixel. The cross-sectional shape of the glitter toner particles is determined by the difference in brightness (contrast) between the embedding epoxy resin and the binder resin of the glitter toner particles.

[0029] The STEM image contains cross sections of glossy toner particles of various sizes, and glossy toner particle cross sections whose major axis length is 80% or more of the volume average particle size of the glossy toner particles are selected, and 200 glossy toner particle cross sections are randomly selected from these and observed. The reason for selecting a cross section whose major axis length is 80% or more of the volume average particle diameter is that a cross section whose major axis length is less than 80% of the volume average particle diameter is predicted to be a cross section of the end of a glitter toner particle, and the cross section of the end of a glitter toner particle does not well reflect the state of the domains within the glitter toner particle. In the present disclosure, the major axis length is the length of the longest straight line among all straight lines connecting two points on the contour line.

[0030] The average major axis length Dw of the release agent domains is the arithmetic mean of the major axis lengths of the release agent domains when all of the release agent domains contained in 200 glitter toner particles are measured. The average aspect ratio of the release agent domains is the arithmetic mean of the aspect ratios of all the release agent domains contained in 200 glitter toner particles when all of these domains are measured. The aspect ratio of the release agent domain is the ratio of the major axis length to the minor axis length (major axis length / minor axis length). The minor axis length is the length of the longest straight line that is perpendicular to the major axis and connects the opposing contour lines. The average major axis length Dp of the glitter pigment is the arithmetic mean of the major axis lengths of the glitter pigments when all of the glitter pigments contained in 200 glitter toner particles are measured.

[0031] The area of the release agent domain is the total area of all the release agent domains contained in 200 glitter toner particles when these domains are measured. The surface layer portion of the glitter toner particle extending to a depth of 1 μm from the surface of the glitter toner particle is a region extending to a depth of 1 μm on a straight line from the surface of the glitter toner particle to the center of gravity of the glitter toner particle. The center of gravity of the glitter toner particle is determined by the number of pixels in the glitter toner particle, n, and the x and y coordinates of each pixel, x i , y i When (i=1,2,…,n), the x coordinate of the center of gravity = (x i y coordinate of the center of gravity = (y i (total of ) / n.

[0032] In the glitter toner of this embodiment, from the viewpoint that the release agent that seeps out of the glitter toner particles during image fixing thickens and remains in an appropriate amount in the nip portion of the fixing member, the mass ratio of the amount of release agent contained in the glitter toner particles to the amount of free oil present in the glitter toner (free oil / release agent) is preferably 0.03 or more and 2.00 or less, more preferably 0.05 or more and 2.00 or less, even more preferably 0.08 or more and 1.80 or less, and even more preferably 0.10 or more and 1.50 or less.

[0033] A method for measuring the amount of free oil present in a glitter toner will be described. The glossy toner containing the external additives was dispersed in hexane to a toner concentration of 5% by mass, and ultrasonic waves (output 20 W, frequency 20 kHz) were applied for 20 minutes, followed by centrifugation to precipitate the solids. When the mass of the sample glossy toner is Wb and the amount of solids after centrifugation is Wa, the mass percentage (%) of free oil contained in the glossy toner is expressed by the following formula: Mass fraction of free oil (%) = (Wb-Wa) / Wb x 100 The mass of the free oil present in a unit amount of glitter toner is calculated from the mass ratio (%) of the free oil.

[0034] The glossy toner according to this embodiment preferably exhibits at least one endothermic peak in a temperature range of 80°C or higher and 100°C or lower when subjected to differential scanning calorimetry. This thermal characteristic can be achieved by incorporating a release agent having a melting temperature of 80°C or higher and 100°C or lower into the glossy toner particles. In a glossy toner having this thermal characteristic, the release agent easily seeps out of the glossy toner particles during image fixing. Differential scanning calorimetry (DSC) is performed using a differential scanning calorimetry device by placing 5.0 mg±0.3 mg of photoluminescent toner in an aluminum sample pan and measuring the temperature in a nitrogen atmosphere from room temperature to 150°C at a rate of 5°C / min.

[0035] The toner according to this embodiment will be described in detail below.

[0036] [Photoluminescent toner particles] The glitter toner particles contain a binder resin, a release agent, and a glitter pigment, and may also contain other additives as required.

[0037] -Binder resin- Examples of binder resins include homopolymers of monomers such as styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), and olefins (e.g., ethylene, propylene, butadiene, etc.), and vinyl resins made of copolymers of two or more of these monomers. Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin, mixtures of these with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the presence of these. These binder resins may be used alone or in combination of two or more.

[0038] As the binder resin, a polyester resin is preferable. Examples of polyester resins include known amorphous polyester resins. The polyester resin may be used in combination with a crystalline polyester resin. The crystalline polyester resin is preferably used in an amount of 2% by mass to 40% by mass (preferably 2% by mass to 20% by mass) of the total binder resin.

[0039] The "crystalline" nature of a resin refers to the presence of a clear endothermic peak rather than a stepwise change in the amount of heat absorbed in differential scanning calorimetry (DSC). Specifically, this refers to the half-width of the endothermic peak being within 10°C when measured at a heating rate of 10°C / min. The term "amorphous" for a resin means that the half-width exceeds 10°C, that the endothermic amount exhibits a stepwise change, or that no clear endothermic peak is observed.

[0040] Amorphous polyester resin The amorphous polyester resin may be, for example, a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product or a synthesized product may be used.

[0041] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, and sebacic acid), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids. The polycarboxylic acid may be a trivalent or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polycarboxylic acids may be used alone or in combination of two or more.

[0042] 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, preferred polyhydric alcohols are aromatic diols and alicyclic diols, and more preferred are aromatic diols. As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked or branched structure may be used in combination with the diol. Examples of trihydric or higher polyhydric alcohols include glycerin, trimethylolpropane, and pentaerythritol. The polyhydric alcohols may be used alone or in combination of two or more.

[0043] The glass transition temperature (Tg) of the amorphous polyester resin is preferably from 50° C. to 80° C., more preferably from 50° C. to 65° C. The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, is determined from the “extrapolated glass transition onset temperature” described in the method for determining glass transition temperature in JIS K7121-1987 “Method for measuring transition temperature of plastics.”

[0044] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, more preferably 2 or more and 60 or less. The weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). Molecular weight measurement by GPC is performed using a Tosoh GPC HLC-8120GPC measuring device and a Tosoh TSKgel SuperHM-M (15 cm) column in THF solvent. The weight-average molecular weight and number-average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples.

[0045] Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polycarboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthesized product may be used. Since the crystalline polyester resin easily forms a crystalline structure, a polycondensate using a linear aliphatic polymerizable monomer is preferred over a polymerizable monomer having an aromatic ring.

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

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

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

[0049] The melting temperature of the crystalline polyester resin is preferably 50° C. or higher and 100° C. or lower, more preferably 55° C. or higher and 90° C. or lower, and even more preferably 60° C. or higher and 85° C. or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) as the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperatures of plastics."

[0050] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0051] The content of the binder resin is preferably 40% by mass to 70% by mass, more preferably 50% by mass to 65% by mass, and even more preferably 50% by mass to 60% by mass, based on the total amount of the glitter toner particles.

[0052] -Mold release agent- Examples of release agents include hydrocarbon waxes, natural waxes such as carnauba wax, rice wax, and candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, and ester waxes such as fatty acid esters and montanic acid esters, but are not limited thereto.

[0053] As the release agent, ester wax is preferred, and fatty acid ester wax is more preferred, from the viewpoint of easily distributing the release agent on the surface layer portion of the glitter toner particles.

[0054] The melting temperature of the release agent is preferably from 50° C. to 110° C., more preferably from 60° C. to 100° C., and even more preferably from 80° C. to 100° C. The melting temperature of the release agent is determined from a DSC curve obtained by differential scanning calorimetry in accordance with JIS K7121-1987 "Method for measuring transition temperature of plastics" and "Peak melting temperature".

[0055] The content of the release agent is preferably from 1% to 20% by mass, more preferably from 5% to 15% by mass, and even more preferably from 5% to 10% by mass, based on the total amount of the glitter toner particles.

[0056] -Brilliant pigments- The bright pigment is a pigment that exhibits bright properties. The bright pigment preferably has a flat shape from the viewpoint of increasing the intensity of specular reflection.

[0057] Examples of luster pigments include powders of metals such as aluminum, brass, bronze, nickel, stainless steel, and zinc; mica coated with titanium oxide, yellow iron oxide, and the like; flaky or plate-like crystals of aluminosilicates, basic carbonates, barium sulfate, titanium oxide, bismuth oxychloride, and the like; flaky glass powders, flaky glass powders vapor-deposited with metal; and guanine crystals.

[0058] As the bright pigment, metal powder is preferred from the viewpoint of specular reflection intensity, and aluminum is preferred from the viewpoint of ease of obtaining flat powder. That is, flat aluminum powder is preferred as the bright pigment. The surface of the metal powder may be coated with acrylic resin, polyester resin, or the like.

[0059] The average major axis length / average thickness of the bright pigment is preferably 5 or more and 200 or less, more preferably 10 or more and 100 or less, and even more preferably 30 or more and 70 or less.

[0060] The content of the glitter pigment is preferably from 1 to 50% by mass, more preferably from 10 to 30% by mass, and even more preferably from 15 to 25% by mass, based on the total glitter toner particles.

[0061] -Coloring agent- The glittering toner particles may contain a colorant, such as carbon black, chrome yellow, Hansa Yellow, benzidine yellow, threne yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, Balkan orange, watch young red, permanent red, brilliant carmine 3B, brilliant carmine 6B, DuPont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, Examples of suitable dyes include pigments such as ultramarine blue, chalco oil blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, and malachite green oxalate; and dyes such as acridine-based, xanthene-based, azo-based, benzoquinone-based, azine-based, anthraquinone-based, thioindigo-based, dioxazine-based, thiazine-based, azomethine-based, indigo-based, phthalocyanine-based, aniline black-based, polymethine-based, triphenylmethane-based, diphenylmethane-based, and thiazole-based dyes. The colorant may be used alone or in combination of two or more kinds.

[0062] The colorant may be surface-treated as needed, or may be used in combination with a dispersant. A plurality of colorants may be used in combination.

[0063] The content of the colorant is preferably from 1% by mass to 30% by mass, more preferably from 3% by mass to 15% by mass, based on the total amount of the glitter toner particles.

[0064] -Other additives- Examples of other additives include known additives such as magnetic materials, charge control agents, inorganic powders, etc. These additives are contained in the glitter toner particles as internal additives.

[0065] -Characteristics of glitter toner particles- The glitter toner particles may be glitter toner particles of a single layer structure, or may be glitter toner particles of a so-called core-shell structure composed of a core (core particle) and a coating layer (shell layer) that covers the core. The glitter toner particles of a core-shell structure may be composed of, for example, a core containing a binder resin, a release agent, and a glitter pigment, and a coating layer containing a binder resin.

[0066] The volume average particle size of the glitter toner particles is preferably 1 μm or more and 22 μm or less, and more preferably 3 μm or more and 20 μm or less.

[0067] The volume average particle size of photoluminescent toner particles is measured using a Coulter Multisizer II (manufactured by Beckman Coulter) and an 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% by weight aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) 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, and the particle size distribution of particles ranging from 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 50,000.

[0068] From the viewpoint of obtaining good glitter and image quality, the average major axis length of the glitter toner particles is preferably 0.5 μm or more and 30 μm or less, more preferably 1 μm or more and 30 μm or less, even more preferably 3 μm or more and 20 μm or less, and even more preferably 5 μm or more and 15 μm or less. When the average length in the thickness direction of the glitter toner particles is taken as 1, the average major axis length is preferably 5 to 200, more preferably 10 to 100, and even more preferably 30 to 70.

[0069] The major axis length and thickness of the photoluminescent toner particles were determined by image analysis of 200 photoluminescent toner particles in the STEM image described above. The major axis length is the length of the longest straight line among all lines connecting two points on the contour line. The thickness is the length of the longest straight line among lines perpendicular to the major axis that connects opposing contour lines.

[0070] [External additives] The glossy toner according to this embodiment is a toner in which at least silicone oil-treated silica particles are externally added to glossy toner particles. The glossy toner according to this embodiment may also contain external additives other than the silicone oil-treated silica particles.

[0071] The silicone oil of the silicone oil-treated silica particles is preferably dimethyl silicone oil. The silicone oil treatment of silica particles is carried out, for example, by dispersing the particles in silicone oil dissolved in alcohol, and then using an evaporator to remove the alcohol and dry the particles.

[0072] The average primary particle size of the silicone oil-treated silica particles is preferably 40 nm or more and 140 nm or less, more preferably 40 nm or more and 120 nm or less, and even more preferably 40 nm or more and 100 nm or less, from the viewpoint of supplying an appropriate amount of silicone oil to the surface of the glitter toner particles.

[0073] The primary particle size of silicone oil-treated silica particles is the diameter of a circle having the same area as the primary particle image (so-called circle-equivalent diameter), and the average primary particle size is the particle size that is the cumulative 50% from the smallest diameter side in the number-based distribution of primary particle sizes. The method for measuring the primary particle size of the silicone oil-treated silica particles will be described. The bright toner containing external additives was analyzed using an energy dispersive X-ray analyzer (EDX) (Horiba, Ltd., EMAX Evolution X-Max 80mm 2Images were taken at 40,000x magnification using a scanning electron microscope (SEM) (Hitachi High-Technologies, S-4800) equipped with a 3D microscope. EDX analysis was used to identify 500 primary particles of silicone oil-treated silica particles within one field of view based on the presence of silicon and carbon atoms. The identified silicone oil-treated silica particles were analyzed using image processing and analysis software WinRoof (Mitani Shoji Co., Ltd.), and the circle-equivalent diameter of each primary particle image was determined.

[0074] The glitter toner may contain external additives other than the silicone oil-treated silica particles, such as TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n , Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc. The surfaces of these external additives are preferably subjected to a hydrophobic treatment. The hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, and examples thereof include silane-based coupling agents, silicone oil, titanate-based coupling agents, and aluminum-based coupling agents.

[0075] Other external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate, and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and particles of fluorine-based polymers), and the like.

[0076] The content of the silicone oil-treated silica particles contained in the glitter toner is preferably 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less, based on the total amount of external additives contained in the glitter toner.

[0077] The amount of the external additive added is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.5% by mass or less, based on the glitter toner particles.

[0078] [Method for manufacturing glitter toner] The glitter toner according to this embodiment can be obtained by producing glitter toner particles and then externally adding silicone oil-treated silica particles to the glitter toner particles.

[0079] The glitter toner particles may be produced by either a dry production method (for example, a kneading and pulverization method) or a wet production method (for example, an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method, etc.). There are no particular restrictions on these production methods, and any known production method may be used. Among these, it is preferable to obtain glitter toner particles by the aggregation and coalescence method.

[0080] When the glitter toner particles are produced by the aggregation and coalescence method, for example, a step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed (a resin particle dispersion preparation step); a step of preparing a release agent particle dispersion liquid in which release agent particles are dispersed (a release agent particle dispersion liquid preparation step); a step of preparing a bright pigment dispersion in which a bright pigment is dispersed (bright pigment dispersion preparation step); a step of aggregating the mixed particles in a mixed dispersion obtained by mixing a resin particle dispersion, a release agent particle dispersion, and a bright pigment dispersion to form aggregated particles (aggregated particle forming step); a step of heating the aggregated particle dispersion in which the aggregated particles are dispersed to fuse and coalesce the aggregated particles, thereby forming glitter toner particles (a fusion and coalescence step); The glitter toner particles are produced through the above steps.

[0081] -Resin particle dispersion preparation process- The resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0082] Examples of the dispersion medium used in the resin particle dispersion include aqueous media. Examples of aqueous media include water such as distilled water and ion-exchanged water, alcohols, etc. These may be used alone or in combination of two or more.

[0083] Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly preferred. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. The surfactants may be used alone or in combination of two or more.

[0084] In a resin particle dispersion, resin particles can be dispersed in a dispersion medium by common dispersion methods such as a rotary shear homogenizer, a ball mill with media, a sand mill, or a Dynomill. Depending on the type of resin particles, the resin particles may be dispersed in a dispersion medium by a phase inversion emulsification method. The phase inversion emulsification method involves dissolving the resin to be dispersed in a hydrophobic organic solvent in which the resin is soluble, neutralizing the organic continuous phase (O phase) by adding a base, and then introducing an aqueous medium (W phase) to invert the phase from W / O to O / W, thereby dispersing the resin in particulate form in the aqueous medium.

[0085] The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, 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 particle size distribution obtained by measurement with a laser diffraction particle size distribution analyzer (e.g., HORIBA LA-700), and the cumulative distribution for the volume of the divided particle size range (channel) is calculated from the smallest particle size side, and the particle size at which the cumulative 50% of all particles is determined as the volume average particle size D50v. The volume average particle sizes of particles in other dispersions are also measured in the same way.

[0086] The content of resin particles contained 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.

[0087] -Preparation process of release agent particle dispersion- For example, the release agent, the aqueous medium, and the surfactant are mixed and dispersed in a disperser (e.g., a pressure discharge homogenizer or a rotary shear homogenizer) while being heated. The aqueous medium and the surfactant are the same as those described above for the resin particle dispersion.

[0088] After the dispersion treatment, a flocculating agent may be added to aggregate the release agent particles. Examples of the flocculating agent include surfactants having a polarity opposite to that of the surfactant used for dispersion, inorganic metal salts, and divalent or higher metal complexes.

[0089] The volume average particle size of the particles dispersed in the release agent particle dispersion is preferably 0.1 μm or more and 1.0 μm or less. The content of particles contained 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.

[0090] -Brilliant pigment dispersion preparation process- For example, the bright pigment, an aqueous medium, and a surfactant are mixed and dispersed in a disperser (e.g., a rotary shear homogenizer). The aqueous medium and surfactant are the same as those described above for the resin particle dispersion.

[0091] The content of the bright pigment in the bright pigment dispersion is preferably from 5% to 50% by mass, and more preferably from 10% to 40% by mass.

[0092] -Agglomerated particle formation process- Next, the resin particle dispersion, the release agent particle dispersion, and the luster pigment dispersion are mixed together, and the resin particles, the release agent particles, and the luster pigment are hetero-aggregated in the mixed dispersion to form aggregated particles (also referred to as core particles) containing the resin particles, the release agent particles, and the luster pigment.

[0093] Specifically, for example, an aggregating agent is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to be acidic (for example, pH 2 or higher and 5 or lower), and a dispersion stabilizer is added as necessary.Then, the mixed dispersion is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles minus 30°C or higher and the glass transition temperature minus 10°C or lower), causing the particles dispersed in the mixed dispersion to aggregate and form aggregated particles. In the aggregate particle formation step, for example, the mixed dispersion may be stirred with a rotary shear homogenizer, an aggregating agent may be added at room temperature (e.g., 25°C), the pH of the mixed dispersion may be adjusted to an acidic value (e.g., pH 2 or more and 5 or less), a dispersion stabilizer may be added as needed, and then the mixture may be heated.

[0094] Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion, an inorganic metal salt, and a divalent or higher metal complex. When a metal complex is used as the flocculant, the amount of surfactant used can be reduced, and the charging characteristics can be improved. If necessary, an additive that forms a complex or a similar bond with the metal ions of the flocculant may be used together with the flocculant, and a chelating agent is preferably used as this additive.

[0095] 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. The chelating agent may be a water-soluble chelating agent, such as hydroxycarboxylic acid (e.g., tartaric acid, citric acid, gluconic acid), or aminocarboxylic acid (e.g., iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), or ethylenediaminetetraacetic acid (EDTA). The amount of the chelating agent added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, relative to 100 parts by mass of the resin particles.

[0096] -Fusion / unification process- Next, the pH of the aggregated particle dispersion in which the aggregated particles are dispersed is adjusted to alkaline, and the aggregated particles are fused and coalesced by heating to a temperature above the glass transition temperature of the resin particles (for example, a temperature 10 to 30°C higher than the glass transition temperature of the resin particles), forming shiny toner particles. Before heating, the pH of the aggregated particle dispersion is adjusted to alkaline (for example, pH 7 to 9), which swells the binder resin and promotes the growth of release agent domains. After heating, the reached temperature is maintained for, for example, 1 to 6 hours, then the pH is lowered from neutral to weakly acidic, and then the dispersion in which the fused and coalesced particles are dispersed is cooled.

[0097] Through the above steps, glittering toner particles are obtained. After obtaining the aggregated particle dispersion liquid in which the aggregated particles are dispersed, the aggregated particle dispersion liquid may be further mixed with a resin particle dispersion liquid and a release agent particle dispersion liquid to aggregate the aggregated particles so that the resin particles and the release agent particles are further attached to the surfaces of the aggregated particles, thereby forming second aggregated particles; and the second aggregated particle dispersion liquid in which the second aggregated particles are dispersed may be heated to fuse and coalesce the second aggregated particles, thereby forming glittering toner particles having a core-shell structure.

[0098] After the fusion and coalescence process is completed, the glitter toner particles in the dispersion are subjected to a known washing process, solid-liquid separation process, and drying process to obtain dried glitter toner particles. In the washing process, from the viewpoint of chargeability, it is preferable to perform sufficient substitution washing with ion-exchanged water. In the solid-liquid separation process, from the viewpoint of productivity, it is preferable to perform suction filtration, pressure filtration, etc. In the drying process, from the viewpoint of productivity, it is preferable to perform freeze drying, air flow drying, fluidized bed drying, vibration fluidized bed drying, etc.

[0099] The toner according to this embodiment is produced by, for example, adding silicone oil-treated silica particles to the obtained dry glitter toner particles and mixing them. The mixing can be carried out using, for example, a V blender, a Henschel mixer, a Loedige mixer, or the like. Furthermore, if necessary, coarse particles may be removed from the toner using a vibrating sieve, an air sieve, or the like.

[0100] <Electrostatic image developer> The electrostatic image developer according to the present embodiment contains at least the photoluminescent toner according to the present embodiment. The electrostatic image developer according to the present embodiment may be a one-component developer containing only the photoluminescent toner according to the present embodiment, or may be a two-component developer in which the photoluminescent toner is mixed with a carrier.

[0101] The carrier is not particularly limited, and known carriers can be used. Examples of the carrier include coated carriers in which the surface of a core material made of magnetic powder is coated with a resin; magnetic powder dispersion carriers in which magnetic powder is dispersed in a matrix resin; and resin-impregnated carriers in which porous magnetic powder is impregnated with a resin. The magnetic powder dispersion carrier and resin-impregnated carrier may be carriers in which the constituent particles of the carrier are used as a core material and the surface of the core material is coated with a resin.

[0102] Examples of magnetic powder include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0103] 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 resins containing organosiloxane bonds or modified products thereof, fluororesin, polyester, polycarbonate, phenolic resin, and epoxy resin. The coating resin and matrix resin may contain additives such as conductive particles. Examples of conductive particles include metals such as gold, silver, and copper; carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0104] Examples of methods for coating the surface of a core material with a resin include a method of coating with a coating layer-forming solution prepared by dissolving the coating resin and various additives (used as needed) in an appropriate solvent. The solvent is not particularly limited and may be selected taking into consideration the type of resin used, its applicability, and the like. Specific resin coating methods include an immersion method in which the core material is immersed in the coating layer-forming solution; a spray method in which the coating layer-forming solution is sprayed onto the core material surface; a fluidized bed method in which the coating layer-forming solution is sprayed onto the core material while suspended in flowing air; and a 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.

[0105] The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner:carrier=1:100 to 30:100, and more preferably 3:100 to 20:100.

[0106] <Image forming device, image forming method> The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, a developing unit that contains an electrostatic image developer and develops the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer, a transfer unit that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing unit that fixes the toner image transferred to the surface of the recording medium. The electrostatic image developer according to the present embodiment is used as the electrostatic image developer.

[0107] The image forming apparatus according to this embodiment carries out an image forming method (the image forming method according to this embodiment) that includes a charging step of charging the surface of an image carrier, an electrostatic image forming step of forming an electrostatic image on the surface of the charged image carrier, a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer according to this embodiment, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0108] The image forming apparatus according to the present embodiment may be any of known image forming apparatuses, such as a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; an intermediate transfer type apparatus that primarily transfers a toner image formed on the surface of an image carrier to the surface of an intermediate transfer medium, and then secondarily transfers the toner image transferred to the surface of the intermediate transfer medium to the surface of a recording medium; an apparatus equipped with a cleaning means that cleans the surface of the image carrier after the transfer of the toner image but before charging; and an apparatus equipped with a discharging means that irradiates the surface of the image carrier with discharging light to discharge it after the transfer of the toner image but before charging.

[0109] When the image forming apparatus according to the present embodiment is an apparatus of the intermediate transfer type, the transfer means is configured to have, for example, an intermediate transfer body onto whose surface a toner image is transferred, a primary transfer means for primarily transferring the toner image formed on the surface of the image carrier onto the surface of the intermediate transfer body, and a secondary transfer means for secondarily transferring the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

[0110] In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge that contains the electrostatic image developer according to the present embodiment and is equipped with the developing means is preferably used.

[0111] The image forming apparatus according to this embodiment may be a tandem type image forming apparatus in which an image forming unit that forms a glossy toner image and at least one image forming unit that forms a non-glossy toner image are arranged in parallel, or may be an image forming apparatus that is equipped only with an image forming unit that forms a glossy toner image.

[0112] An example of an image forming apparatus according to the present embodiment will be described below, but the present invention is not limited to this. In the following description, the main parts shown in the drawings will be described, and the description of the rest will be omitted.

[0113] FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus according to this embodiment, and is a diagram showing a five-tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in Figure 1 includes first through fifth electrophotographic image forming units 10G, 10Y, 10M, 10C, and 10K (image forming means) that output images in each of the colors glitter (G), yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10G, 10Y, 10M, 10C, and 10K are arranged side by side horizontally spaced a predetermined distance apart from one another. These units 10G, 10Y, 10M, 10C, and 10K may be process cartridges that are detachably attached to the image forming apparatus.

[0114] An intermediate transfer belt (an example of an intermediate transfer body) 20 is provided below each of the units 10G, 10Y, 10M, 10C, and 10K and extends through each unit. The intermediate transfer belt 20 is provided wrapped around a drive roll 22, a support roll 23, and an opposing roll 24, which are in contact with the inner surface of the intermediate transfer belt 20, and runs in a direction from the first unit 10G toward the fifth unit 10K. An intermediate transfer body cleaning device 21 is provided on the image bearing surface side of the intermediate transfer belt 20, facing the drive roll 22.

[0115] The developing devices (examples of developing means) 4G, 4Y, 4M, 4C, and 4K of each unit 10G, 10Y, 10M, 10C, and 10K are supplied with photoluminescent, yellow, magenta, cyan, and black toner contained in toner cartridges 8G, 8Y, 8M, 8C, and 8K, respectively.

[0116] Since the first to fifth units 10G, 10Y, 10M, 10C, and 10K have the same configuration and operation, we will explain here the first unit 10G, which forms a glossy image and is arranged upstream in the direction of travel of the intermediate transfer belt.

[0117] The first unit 10G has a photoconductor 1G that acts as an image carrier. Around the photoconductor 1G, there are arranged in this order: a charging roll (an example of a charging means) 2G that charges the surface of the photoconductor 1G to a predetermined potential; an exposure device (an example of an electrostatic image forming means) 3G that exposes the charged surface to a laser beam based on a color-separated image signal to form an electrostatic image; a developing device (an example of a developing means) 4G that supplies toner to the electrostatic image to develop it; a primary transfer roll (an example of a primary transfer means) 5G that transfers the developed toner image onto the intermediate transfer belt 20; and a photoconductor cleaning device (an example of a cleaning means) 6G that removes toner remaining on the surface of the photoconductor 1G after the primary transfer.

[0118] The primary transfer roll 5G is disposed inside the intermediate transfer belt 20 and is positioned opposite the photoconductor 1G. A bias power supply (not shown) that applies a primary transfer bias is connected to the primary transfer rolls 5G, 5Y, 5M, 5C, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

[0119] The operation of forming a lustrous image in first unit 10G will be described below. First, prior to operation, the surface of the photosensitive member 1G is charged to a potential of -600V to -800V by the charging roll 2G. The photoconductor 1G is conductive (for example, the volume resistivity at 20°C is 1×10 -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate with a resistivity of Ωcm or less. This photosensitive layer is normally highly resistive (the resistance of ordinary resins), but when irradiated with a laser beam, the resistivity of the irradiated portion changes. Therefore, a laser beam is irradiated onto the charged surface of the photosensitive drum 1G from an exposure device 3G in accordance with photoluminescent image data sent from a control unit (not shown). This forms an electrostatic charge image of a photoluminescent image pattern on the surface of the photosensitive drum 1G.

[0120] An electrostatic image is an image formed on the surface of the photosensitive element 1G by charging it; it is a so-called negative latent image formed when the resistivity of the irradiated portion of the photosensitive layer is reduced by the laser beam from the exposure device 3G, causing the charged charges on the surface of the photosensitive element 1G to flow, while the charges remain in the portions not irradiated by the laser beam. The electrostatic image formed on the photoreceptor 1G rotates to a predetermined development position as the photoreceptor 1G moves, where the electrostatic image on the photoreceptor 1G is developed into a toner image by the developing device 4G and made visible.

[0121] The developing device 4G contains an electrostatic image developer containing, for example, at least a photosensitive toner and a carrier. The photosensitive toner is frictionally charged by stirring inside the developing device 4G and is held on a developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the charge on the photosensitive drum 1G. As the surface of the photosensitive drum 1G passes through the developing device 4G, the photosensitive toner electrostatically adheres to the discharged latent image portion on the surface of the photosensitive drum 1G, and the latent image is developed with the photosensitive toner. The photosensitive drum 1G with the photosensitive toner image formed thereon continues to travel at a predetermined speed, and the toner image developed on the photosensitive drum 1G is transported to a predetermined primary transfer position.

[0122] When the glossy 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 from the photoreceptor 1G toward the primary transfer roll 5G acts on the toner image, causing the toner image on the photoreceptor 1G to be transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a (+) polarity opposite to the (-) polarity of the toner, and is controlled by a control unit (not shown) in the first unit 10G to, for example, +10 μA.

[0123] After the toner image is transferred to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with a cleaning blade provided on the photoreceptor cleaning device 6G. The toner remaining on the photoreceptor 1G is removed and collected by the photoreceptor cleaning device 6G.

[0124] The primary transfer biases applied to the primary transfer rolls 5Y, 5M, 5C, and 5K of the second unit 10Y and subsequent units are also controlled in accordance with the first unit. In this way, the intermediate transfer belt 20 onto which the glossy toner image has been transferred in the first unit 10G is conveyed sequentially through the second to fifth units 10Y, 10M, 10C, and 10K, where the toner images of each color are superimposed and transferred.

[0125] The intermediate transfer belt 20, onto which the five-color toner images have been multiplex-transferred through the first to fifth units, reaches a secondary transfer section composed of the intermediate transfer belt 20, an opposing 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 arranged on the image bearing 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 opposing roll 24. The transfer bias applied at this time has a negative polarity, the same as the negative polarity of the toner. 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 based on resistance detected by resistance detection means (not shown) that detects resistance in the secondary transfer section, and is voltage-controlled.

[0126] After transferring the toner image onto the recording paper P, the intermediate transfer belt 20 continues to run and comes into contact with a cleaning blade provided on the intermediate transfer body cleaning device 21. Toner remaining on the intermediate transfer belt 20 is removed and collected by the intermediate transfer body cleaning device 21.

[0127] The recording paper P onto which the toner image has been transferred is sent to the pressure contact portion (nip portion) 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, forming a fixed image.

[0128] Examples of the recording paper P onto which the toner image is transferred include plain paper used in electrophotographic copiers, printers, etc. In addition to the recording paper P, examples of the recording medium include overhead projector sheets and the like. To further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper in which the surface of plain paper is coated with resin or the like, or art paper for printing, etc., is preferably used.

[0129] The recording paper P on which the color image has been fixed is conveyed toward the discharge section, and the series of color image forming operations is completed.

[0130] The image formation mode by the image forming apparatus shown in Fig. 1 is not limited to the above. A mode in which only the first unit 10G is operated to form a glossy image on one side of the recording paper P, and then the recording paper P is sent upstream in the direction of travel of the intermediate transfer belt, and the second unit 10Y to the fifth unit 10K are operated to form a color image on the glossy image on the recording paper P; A mode in which only the first unit 10G is operated to form a glossy image on one side of the recording paper P, and then the recording paper P is sent upstream in the direction of travel of the intermediate transfer belt, and the first unit 10G to the fifth unit 10K are operated to form a color image and a glossy image on the glossy image on the recording paper P; An example of such a configuration is as follows: only the first unit 10G is operated to form a glossy image on one side of the recording paper P, then the recording paper P is sent upstream in the direction of travel of the intermediate transfer belt, only the first unit 10G is operated again to overlay a glossy image on the glossy image on the recording paper P, the recording paper P is returned upstream in the direction of travel of the intermediate transfer belt, and the second unit 10Y to the fifth unit 10K are operated to form a color image on the multi-layer glossy image on the recording paper P.

[0131] <Process cartridges, toner cartridges> The process cartridge according to this embodiment will be described. The process cartridge according to this embodiment is a process cartridge that is detachably attached to an image forming apparatus and that contains the electrostatic image developer according to this embodiment and is equipped with a developing means that develops an electrostatic image formed on the surface of an image carrier using the electrostatic image developer into a toner image.

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

[0133] An example of a process cartridge according to the present embodiment will be described below, but the present invention is not limited to this. In the following description, the main parts shown in the drawings will be described, and the description of the rest will be omitted.

[0134] FIG. 2 is a schematic diagram showing the configuration of the process cartridge according to the present embodiment. The process cartridge 200 shown in FIG. 2 is configured to integrally combine and hold a photosensitive member 107 (an example of an image carrier), a charging roll 108 (an example of a charging means) provided around the photosensitive member 107, a developing device 111 (an example of a developing means), and a photosensitive member cleaning device 113 (an example of a cleaning means), which are held by a housing 117 provided with, for example, mounting rails 116 and an opening 118 for exposure, and is made into a cartridge. In FIG. 2, 109 denotes an exposure device (an example of an electrostatic image forming means), 112 denotes a transfer device (an example of a transfer means), 115 denotes a fixing device (an example of a fixing means), and 300 denotes 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 the present embodiment is a toner cartridge that contains the glitter toner according to the present embodiment and is detachably attached to an image forming apparatus. The toner cartridge contains replenishment toner to be supplied to a developing unit provided in the image forming apparatus.

[0136] The image forming apparatus shown in FIG. 1 is configured to accommodate detachable toner cartridges 8G, 8Y, 8M, 8C, and 8K. The developing devices 4G, 4Y, 4M, 4C, and 4K are connected to the toner cartridges corresponding to the respective colors via toner supply pipes (not shown). When the toner stored in a toner cartridge runs low, the toner cartridge is replaced. An example of a toner cartridge according to this embodiment is toner cartridge 8G, which contains the photoluminescent toner according to this embodiment. Toner cartridges 8Y, 8M, 8C, and 8K contain yellow, magenta, cyan, and black toner, respectively. [Example]

[0137] Hereinafter, the embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are by mass. All syntheses, processing, preparations, etc. were carried out at room temperature (25°C ± 3°C) unless otherwise noted.

[0138] <Preparation of Resin Particle Dispersion> [Amorphous polyester resin particle dispersion (A)] Terephthalic acid: 70 parts Fumaric acid: 30 parts Ethylene glycol: 41 parts 1,5-pentanediol: 48 parts The above materials were placed in a reactor equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column. The temperature was raised to 220°C over 1 hour under a nitrogen gas stream, and 1 part of titanium tetraethoxide was added for every 100 parts of the above materials. The temperature was raised to 240°C over 0.5 hours while distilling off the resulting water. The dehydration condensation reaction was continued at 240°C for 1 hour, and then the reaction mixture was cooled. Thus, an amorphous polyester resin (A) with a weight-average molecular weight of 96,000 and a glass transition temperature of 61°C was obtained.

[0139] A tank equipped with a temperature control device and nitrogen purge device was charged with 40 parts of ethyl acetate and 25 parts of 2-butanol to prepare a mixed solvent. Then, 100 parts of amorphous polyester resin (A) was gradually added and dissolved. A 10% aqueous ammonia solution (equivalent to three times the molar amount of the resin's acid value) was added and stirred for 30 minutes. The atmosphere inside the reaction vessel was then purged with dry nitrogen, the temperature was maintained at 40°C, and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts / min while stirring the mixed solution, resulting in emulsification. After the dropwise addition, the emulsion was returned to 25°C, and the solvent was removed under reduced pressure to obtain a resin particle dispersion containing resin particles with a volume average particle size of 160 nm. Ion-exchanged water was added to this resin particle dispersion to adjust the solids content to 20%, yielding amorphous polyester resin particle dispersion (A).

[0140] [Crystalline polyester resin particle dispersion (C)] 1,10-decanedicarboxylic acid: 265 parts 1,6-Hexanediol: 168 parts Dibutyltin oxide (catalyst): 0.3 parts The above materials were placed in a heated and dried reactor, the air in the reactor was replaced with nitrogen gas to create an inert atmosphere, and the mixture was stirred and refluxed at 180°C for 5 hours using mechanical stirring. The temperature was then gradually increased to 230°C under reduced pressure and stirred for 2 hours. When the mixture became viscous, it was air-cooled to stop the reaction. This yielded a crystalline polyester resin (C) with a weight-average molecular weight of 12,700 and a melting temperature of 73°C.

[0141] 90 parts of crystalline polyester resin (C), 1.8 parts of anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK), and 210 parts of ion-exchanged water were mixed, heated to 120°C, and dispersed using a homogenizer (IKA Ultra-Turrax T50), followed by dispersion treatment using a pressure-discharge Gaulin homogenizer for 1 hour to obtain a resin particle dispersion containing resin particles with a volume average particle size of 160 nm. Ion-exchanged water was added to this resin particle dispersion to adjust the solid content to 20%, obtaining crystalline polyester resin particle dispersion (C).

[0142] <Preparation of release agent particle dispersion> [Release agent particle dispersion (W1)] Ester wax (melting temperature 83°C, Nissan Electol WEP-5, NOF Corporation): 180 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 4.5 parts Ion-exchanged water: 410 parts The above materials were heated to 110°C and dispersed using a homogenizer (IKA Ultra Turrax T50), and then further dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin). After the temperature was lowered to room temperature, ion-exchanged water was added to adjust the solid content to 30%, thereby obtaining a release agent particle dispersion (W1). The volume average particle size of the particles dispersed in the release agent particle dispersion (W1) was 252 nm.

[0143] [Release agent particle dispersion (W2)] A release agent particle dispersion (W2) was prepared in the same manner as in the preparation of the release agent particle dispersion (W1), except that the release agent was changed to Fischer-Tropsch wax (melting temperature 94°C, Nippon Seiro Co., Ltd., FNP0090). The volume average particle size of the particles dispersed in the release agent particle dispersion (W2) was 240 nm.

[0144] [Release agent particle dispersion (W3)] A release agent particle dispersion (W3) was prepared in the same manner as in the preparation of the release agent particle dispersion (W1), except that the pressure conditions were changed. The volume average particle size of the particles dispersed in the release agent particle dispersion (W3) was 320 nm.

[0145] [Release agent particle dispersion (W4)] A release agent particle dispersion (W4) was prepared in the same manner as in the preparation of the release agent particle dispersion (W1), except that the pressure conditions were changed. The volume average particle size of the particles dispersed in the release agent particle dispersion (W4) was 212 nm.

[0146] [Release agent particle dispersion (W5)] A release agent particle dispersion (W5) was prepared in the same manner as in the preparation of the release agent particle dispersion (W1), except that the release agent was changed to paraffin wax (melting temperature 75°C, Nippon Seiro Co., Ltd., HNP9). The volume average particle size of the particles dispersed in the release agent particle dispersion (W5) was 241 nm.

[0147] [Release agent particle dispersion (W6)] Release agent particle dispersion (W6) was prepared in the same manner as in the preparation of release agent particle dispersion (W1), except that the release agent was changed to polyethylene wax (melting temperature 104°C, NuCera Solutions, PW725). The volume average particle size of the particles dispersed in release agent particle dispersion (W6) was 230 nm.

[0148] <Preparation of glitter pigment dispersion> [Brilliant pigment dispersion (G1)] Atomized aluminum powder (average particle size 4 μm): 100 parts Mineral spirits: 120 parts Stearic acid: 3 parts The above materials were mixed and milled in a ball mill for 15 hours. Next, 500 parts of ethyl acetate was added, followed by solid-liquid separation. The process of mixing 500 parts of ethyl acetate with the solids was repeated to obtain a flat-shaped aluminum pigment (1).

[0149] Aluminum pigment (1): 100 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1.5 parts Ion-exchanged water: 900 parts The above materials were mixed and dispersed for 1 hour using a Cavitron emulsifying and dispersing machine to obtain a bright pigment dispersion (G1) with a solid content of 10%.

[0150] [Glitter pigment dispersion (G2)] A bright pigment dispersion (G2) was obtained in the same manner as the bright pigment dispersion (G1), except that the atomized aluminum powder had an average particle size of 2 μm.

[0151] [Glitter pigment dispersion (G3)] A brilliant pigment dispersion (G3) was obtained in the same manner as for the brilliant pigment dispersion (G1), except that the atomized aluminum powder had an average particle size of 2.5 μm and the ball mill grinding time was changed to 8 hours.

[0152] <Preparation of silicone oil-treated silica particles> [Silicone oil-treated silica particles (1)] SiCl4, hydrogen gas, and oxygen gas were mixed in the mixing chamber of a combustion burner and then burned at temperatures between 1000 and 3000°C. Silica powder was extracted from the gas after combustion to obtain a silica substrate. Silica particles (1) with a number-average particle size of 85 nm were obtained by adjusting the molar ratio of hydrogen gas to oxygen gas to 1.02:1.

[0153] 100 parts of silica particles (1) and 500 parts of ethanol were placed in an evaporator and stirred for 15 minutes while maintaining the temperature at 40°C. Next, 10 parts of dimethyl silicone oil was added and stirred for 15 minutes, and then 10 parts of dimethyl silicone oil was added and stirred for 15 minutes. Next, the temperature was raised to 90°C to evaporate the ethanol under reduced pressure, and then the mixture was vacuum-dried at 120°C for 30 minutes. In this way, silicone oil-treated silica particles (1) were obtained.

[0154] [Silicone oil-treated silica particles (2)] Silica particles (2) having a number average particle size of 40 nm were obtained in the same manner as silica particles (1), except that the molar ratio of hydrogen gas to oxygen gas was changed to 0.74:1. The silica particles (2) were treated in the same manner as in the silicone oil-treated silica particles (1) to obtain corn oil-treated silica particles (2).

[0155] [Silicone oil-treated silica particles (3)] Silica particles (3) having a number average particle size of 135 nm were obtained in the same manner as silica particles (1), except that the molar ratio of hydrogen gas to oxygen gas was changed to 1.35:1. Corn oil-treated silica particles (3) were obtained using the silica particles (3) in the same manner as in the silicone oil-treated silica particles (1), except that the amount of dimethyl silicone oil added was changed to 4 parts.

[0156] <Preparation of Toner and Developer> [Example 1] -Preparation of first aggregated particles- Amorphous polyester resin particle dispersion (A) (solid content 20%): 170 parts Crystalline polyester resin particle dispersion (C) (solid content 20%): 12 parts Brilliant pigment dispersion (G1) (solid content 10%): 200 parts Release agent particle dispersion (W1) (solid content 30%): 5 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1.5 parts The above materials were placed in a stirring tank, and 0.1 N nitric acid was added to adjust the pH to 3.5. An aluminum sulfate aqueous solution was prepared by dissolving 2.5 parts of aluminum sulfate in 30 parts of ion-exchanged water, and this was added to the stirring tank. After dispersing at 30°C using a homogenizer (IKA Ultra Turrax T50), the mixture was heated to 45°C in a heating oil bath and maintained there until the volume average particle size of the aggregated particles reached 9.0 μm.

[0157] -Creating second aggregated particles- 133 parts of the amorphous polyester resin particle dispersion (A) (solid content 20%) and 15 parts of the release agent particle dispersion (W1) (solid content 30%) were added to a stirring tank and held for 60 minutes to obtain a dispersion containing second aggregated particles. 20 parts of a 10% by mass NTA (nitrilotriacetic acid) metal salt aqueous solution (Chilest 70, manufactured by Chelest Co., Ltd.) was added to the dispersion containing the second aggregated particles.

[0158] -Fusion / unification process- While continuing stirring in the stirring tank, a 1N aqueous solution of sodium hydroxide was added to adjust the pH to 9.5. The temperature was then raised to 90°C at a rate of 0.5°C / min and maintained at that temperature for 3.5 hours. The temperature was then lowered to 30°C at a rate of 0.5°C / min. The solid content was then filtered, thoroughly washed with ion-exchanged water, and dried to obtain glitter toner particles with a volume average particle size of 11.2 μm.

[0159] -External addition of hydrophobic silica particles- 1.8 parts of silicone oil-treated silica particles (1) were added to 100 parts of glittering toner particles, and mixed using a sample mill at 13,000 rpm for 30 seconds, and then sieved through a vibrating sieve with 45 μm openings to obtain an externally added toner.

[0160] -Mixed with Carrier- 100 parts of the carrier and 5 parts of the externally added toner were placed in a V-blender and stirred for 20 minutes. After that, the mixture was sieved through a sieve with 212 μm openings to obtain a developer. The carrier was prepared as follows.

[0161] -Creating a carrier- Ferrite particles (volume average particle size 50 μm): 100 parts Toluene: 14 parts Styrene / methyl methacrylate copolymer (copolymerization ratio 15 / 85): 3 parts Carbon black: 0.2 parts The above materials except for the ferrite particles were dispersed in a sand mill to prepare a dispersion liquid, and this dispersion liquid was placed in a vacuum degassing kneader together with the ferrite particles, and dried under reduced pressure while stirring to obtain a resin-coated carrier.

[0162] [Examples 2 to 15, Comparative Examples 1 and 2] The same procedures as in Example 1 were carried out, except that the formulation of the release agent particle dispersion, the fusion / coalescence process, and the type and amount of silicone oil-treated silica particles were changed as shown in Table 1, to produce the glitter toner particles, the externally added toner, and the developer of each example.

[0163] <Performance evaluation> [Photoluminescent Image Formation] Using an electrophotographic image forming device (Fuji Xerox, Color1000Press), 5,000 sheets of glossy images were continuously printed on A4-sized coated paper (OK Topcoat+paper, Oji Paper Co., Ltd.) in an environment of 10°C temperature and 10% relative humidity. The glossy images consisted of multiple 100% density strip images crossing vertically and horizontally. Next, one full-surface glossy image with 50% density was printed.

[0164] [Evaluation of gloss unevenness] The measurement sample was a strip-shaped gloss image with 100% density printed on the 5,000th sheet. Using a gloss meter GM-26D (Murakami Color Research Laboratory), gloss was measured at a 75-degree incident light angle to the image. Measurements were taken at nine locations where three strips parallel to the short side of the A4 paper, located 3 cm, 8 cm, and 15 cm from one edge of the long side of the A4 paper, and three strips parallel to the long side of the A4 paper, located 3 cm, 6 cm, and 10 cm from one edge of the short side of the A4 paper, intersected with each other. The differences between the maximum and minimum gloss values at the nine locations were classified as A to D, as shown below. The results are shown in Table 2. A: The difference between the maximum and minimum gloss values is less than 2.0 B: The difference between the maximum and minimum gloss values is 2.0 or more and less than 4.0 C: The difference between the maximum and minimum gloss values is 4.0 or more and less than 10.0 D: The difference between the maximum and minimum gloss values is 10.0 or more

[0165] [Image streak evaluation] The full-surface glossy image with a density of 50% was visually observed and classified into the following categories A to D. The results are shown in Table 2. A: No streak-like image defects are observed. B: Very slight streak-like image defects are observed. C: Minor streak-like image defects are observed. Acceptable. D: Streaky image defects are observed scattered over the entire surface. Unacceptable.

[0166] [Table 1]

[0167] [Table 2] [Explanation of symbols]

[0168] 1G, 1Y, 1M, 1C, 1K Photoconductor (an example of an image carrier) 2G, 2Y, 2M, 2C, 2K Charging roll (an example of charging means) 3G, 3Y, 3M, 3C, 3K exposure equipment (an example of electrostatic image forming means) 4G, 4Y, 4M, 4C, 4K developing device (an example of developing means) 5G, 5Y, 5M, 5C, 5K Primary transfer roll (an example of a primary transfer means) 6G, 6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of a cleaning means) 8G, 8Y, 8M, 8C, 8K toner cartridges 10G, 10Y, 10M, 10C, 10K Image Formation Unit 20 Intermediate transfer belt (an example of an intermediate transfer body) 21 Intermediate transfer body cleaning device 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 fixing means) P Recording paper (an example of a recording medium) 107 Photoconductor (an example of an image carrier) 108 Charging roll (an example of charging means) 109 Exposure device (an example of electrostatic image forming means) 111 Developing device (an example of developing means) 112 Transfer device (an example of transfer means) 113 Photosensitive drum cleaning device (an example of cleaning means) 115 Fixing device (an example of fixing means) 116 Mounting Rail 117 Cabinet 118 Exposure opening 200 Process Cartridge 300 Recording paper (an example of a recording medium)

Claims

1. bright toner particles containing a binder resin, a release agent, and a bright pigment and having a release agent domain; silicone oil-treated silica particles externally added to the glitter toner particles, when a cross section of the glitter toner particle is observed, the average aspect ratio (average of major axis length / minor axis length) of the release agent domain is 1.00 or more and 1.40 or less; In a cross-sectional observation of the glitter toner particle, the average major axis length Dw of the release agent domain and the average major axis length Dp of the glitter pigment satisfy the following formula (1): Glitter toner. Formula (1): 0.3≦Dw / Dp≦1.0

2. bright toner particles containing a binder resin, a release agent, and a bright pigment and having a release agent domain; silicone oil-treated silica particles externally added to the glitter toner particles, when a cross section of the glitter toner particle is observed, an area of the release agent domain contained in a surface layer portion of the glitter toner particle to a depth of 1 μm from the surface of the glitter toner particle is 50% or more and 100% or less of a total area of the release agent domain contained in the glitter toner particle, In a cross-sectional observation of the glitter toner particle, the average major axis length Dw of the release agent domain and the average major axis length Dp of the glitter pigment satisfy the following formula (1): Glitter toner. Formula (1): 0.3≦Dw / Dp≦1.0

3. A photoluminescent toner as described in claim 2, wherein, upon cross-sectional observation of the photoluminescent toner particle, the average aspect ratio (average of major axis length / minor axis length) of the release agent domain is 1.00 or more and 1.40 or less.

4. The glitter toner according to any one of claims 1 to 3, wherein, in a cross-sectional observation of the glitter toner particle, an average major axis length Dw of the release agent domains and an average major axis length Dp of the glitter pigment satisfy the following formula (1-1): Formula (1-1): 0.3≦Dw / Dp≦0.8

5. 5. The glitter toner according to claim 1, wherein, in cross-sectional observation of the glitter toner particle, the average aspect ratio (average of major axis length / minor axis length) of the release agent domains is 1.00 or more and 1.25 or less.

6. 6. The glossy toner according to claim 1, wherein, in a cross-sectional observation of the glossy toner particle, an area of the release agent domain contained in a surface layer portion of the glossy toner particle from the surface to a depth of 1 μm is 70% or more and 100% or less of a total area of the release agent domain contained in the glossy toner particle.

7. 7. The glitter toner according to claim 1, wherein the silicone oil-treated silica particles have an average primary particle size of 40 nm or more and 140 nm or less.

8. 8. The glitter toner according to claim 1, wherein, in cross-sectional observation of the glitter toner particle, the average major axis length Dw of the release agent domains is 0.3 μm or more and 2.0 μm or less.

9. 9. The glitter toner according to claim 1, wherein at least one endothermic peak is observed in a temperature range of 80° C. to 100° C. when measured by differential scanning calorimetry.

10. 10. The glitter toner according to claim 1, wherein the release agent contains an ester wax.

11. An electrostatic image developer comprising the glitter toner according to any one of claims 1 to 10.

12. The glossy toner according to any one of claims 1 to 10 is contained therein, A toner cartridge that is detachably attached to an image forming device.

13. a developing unit containing the electrostatic image developer according to claim 11 and developing an electrostatic image formed on a surface of an image carrier into a toner image by using the electrostatic image developer, A process cartridge is detachably mounted in an image forming apparatus.

14. an image carrier; a charging means for charging the surface of the image carrier; an electrostatic image forming means for forming an electrostatic image on the charged surface of the image carrier; a developing unit containing the electrostatic image developer according to claim 11 and developing the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer; a transfer means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing means for fixing the toner image transferred onto the surface of the recording medium; An image forming apparatus comprising:

15. a charging step of charging the surface of the image carrier; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier; a developing step of developing the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer according to claim 11; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing step of fixing the toner image transferred onto the surface of the recording medium; An image forming method comprising the steps of:

Images