Toner set for electrostatic charge image development, electrostatic charge image developer set, toner cartridge set, process cartridge, image forming apparatus, and image forming method

Abstract

To provide a toner set for electrostatic charge image development that is excellent in color unevenness prevention properties in an image to be obtained.SOLUTION: A toner set for electrostatic charge image development has a fluorescent toner including a fluorescent colorant and having a lightness of 75 or more, and a non-fluorescent toner not including a fluorescent colorant. The amount of NH4+ in a surface of the fluorescent toner, which is measured by the ion chromatography method, is 0.05 mg / L or more and 0.30 mg / L or less. The difference between the amount of NH4+ in the surface of the fluorescent toner and the amount of NH4+ in the surface of the non-fluorescent toner, which are measured by the ion chromatography method, is 0.12 mg / L or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a toner carrier for developing an electrostatic latent image with toner supplied to the surface, characterized in that the material constituting at least the surface contains a quaternary ammonium salt group-containing copolymer.

[0003] Patent Document 2 discloses an orange toner characterized by containing a binder resin including a polyester resin having a dodecenyl succinic acid structure as a constituent unit, and CI Pigment Orange 38 in an amount of 5 to 18% by mass relative to the total mass of the toner. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-312136 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-68581 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure relates to the NH4 + or the amount of NH4 on the surface of the fluorescent toner as measured by an ion chromatography method is less than 0.05 mg / L or more than 0.30 mg / L. + and the amount of NH4 on the surface of the non-fluorescent toner. +The object of the present invention is to provide a toner set for developing electrostatic images which is excellent in suppressing color unevenness in the resulting image, compared to when the difference from the amount of the toner set is less than 0.12 mg / L. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> The present invention provides a fluorescent toner containing a fluorescent colorant and having a brightness of 75 or more, and a non-fluorescent toner containing no fluorescent colorant, and a method for measuring the amount of NH4 + The amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is 0.05 mg / L or more and 0.30 mg / L or less. + and the amount of NH4 on the surface of the non-fluorescent toner. + A toner set for developing electrostatic images, the difference between the amount of In addition, the above NH4 + The amount of NH4 detected when the filtrate was analyzed by ion chromatography after weighing 0.5 g of the fluorescent toner or the non-fluorescent toner and adding it to 100 g of ion-exchanged water at 30°C ± 1°C and dispersing it by ultrasonic waves for 30 minutes and then filtering was determined. + The quantity is: <2> NH4 on the surface of the fluorescent toner as measured by ion chromatography + and the amount of NH4 on the surface of the non-fluorescent toner. + The difference between the amount is 0.15 mg / L or more. <1> 10. The toner set for developing electrostatic images according to claim 19. <3> NH4 on the surface of the non-fluorescent toner + The amount is between 0.20 mg / L and 1.00 mg / L <1> 10. The toner set for developing electrostatic images according to claim 19. <4> NH4 on the surface of the fluorescent toner + The amount is between 0.10 mg / L and 0.20 mg / L <1> 10. The toner set for developing electrostatic images according to claim 19. <5> The volume average particle diameter of the fluorescent toner is 5.4 μm or more and 6.2 μm or less. <1> 10. The toner set for developing electrostatic images according to claim 19. <6> The fluorescent colorant contains an azomethine fluorescent pigment having a fluorescent peak wavelength in the wavelength region of the fluorescent spectrum of 500 nm or more and 550 nm or less. <1> 10. The toner set for developing electrostatic images according to claim 19. <7> The fluorescent toner further comprises a non-fluorescent pigment. <1> 10. The toner set for developing electrostatic images according to claim 19. <8> The non-fluorescent pigment in the fluorescent toner contains a non-fluorescent pigment having a reflection peak wavelength in the wavelength region of 480 nm or more and 540 nm or less in the reflection spectrum. <7> 10. The toner set for developing electrostatic images according to claim 19. <9> <1> ~ <8> a first electrostatic image developer containing the fluorescent toner in the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> and a second electrostatic image developer containing the non-fluorescent toner in the toner set for developing electrostatic images according to any one of the above. <10> <1> ~ <8> a first toner cartridge containing the fluorescent toner in the toner set for developing an electrostatic image according to any one of the above items; <1> ~ <8> a second toner cartridge containing the non-fluorescent toner in the toner set for developing electrostatic images according to any one of the above items, and the toner cartridge set is detachably mountable to an image forming apparatus. <11> <9> a first developing means containing the first electrostatic image developer of the electrostatic image developer set described in <9> and a second developing means containing the second electrostatic image developer of the electrostatic image developer set described in 1. above, and the process cartridge is detachably mountable to an image forming apparatus. <12> <1> ~ <8> a first image forming means for forming a first image using the fluorescent toner in the toner set for developing electrostatic images according to any one of the above items; <1> ~ <8> an image forming apparatus comprising: a second image forming means for forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images described in any one of the above items; a transfer means for transferring the first image and the second image onto a recording medium; and a fixing means for fixing the first image and the second image onto the recording medium. <13> <1> ~ <8> a first image forming step of forming a first image using the fluorescent toner of the toner set for developing electrostatic images described in any one of the above items; <1> ~ <8> a second image forming step of forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images described in any one of the above items; a transfer step of transferring the first image and the second image onto a recording medium; and a fixing step of fixing the first image and the second image on the recording medium. [Effects of the Invention]

[0007] <1> or <6> ~ <8> According to the invention, the amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is + or the amount of NH4 on the surface of the fluorescent toner as measured by an ion chromatography method is less than 0.05 mg / L or more than 0.30 mg / L. + and the amount of NH4 on the surface of the non-fluorescent toner. + In comparison with a case where the difference from the amount of the toner of the present invention is less than 0.12 mg / L, a toner set for developing electrostatic images is provided which is excellent in suppressing color unevenness in the resulting image. <2> According to the invention, the amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is + and the amount of NH4 on the surface of the non-fluorescent toner. + In comparison with the case where the difference between the amounts is less than 0.15 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting images. <3> According to the invention, the NH4 + In comparison with when the amount is less than 0.20 mg / L or more than 1.00 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting image. <4> According to the invention, the NH4 + In comparison with when the amount is less than 0.10 mg / L or more than 0.20 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting image. <5> According to the invention, a toner set for developing electrostatic images is provided that is superior in suppressing color unevenness in the resulting image compared to when the volume average particle diameter of the fluorescent toner is less than 5.4 μm or more than 6.2 μm. <9> , <10> , <11> , <12> or <13> According to the invention, in the toner set for developing electrostatic images used, the amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is + or the amount of NH4 on the surface of the fluorescent toner is less than 0.05 mg / L or more than 0.30 mg / L as measured by an ion chromatography method. + and the amount of NH4 on the surface of the non-fluorescent toner. + The present invention provides an electrostatic image developer set, a toner cartridge set, a process cartridge, an image forming apparatus, or an image forming method that are excellent in suppressing color unevenness in the resulting image, compared to when the difference from the amount of the toner cartridge set is less than 0.12 mg / L. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus used in the present embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating an example of a process cartridge used in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[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.

[0010] 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.

[0011] In the present disclosure, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0012] When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0013] 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.

[0014] 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.

[0015] In this disclosure, "toner for developing electrostatic images" is also referred to as "toner," "electrostatic image developer" is also referred to as "developer," and "carrier for developing electrostatic images" is also referred to as "carrier."

[0016] (Electrostatic image developing toner set) The toner set for developing electrostatic images according to the present embodiment includes a fluorescent toner containing a fluorescent colorant and having a brightness of 75 or more, and a non-fluorescent toner containing no fluorescent colorant, and the toner set has a NH4 + The amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is 0.05 mg / L or more and 0.30 mg / L or less. + and the amount of NH4 on the surface of the non-fluorescent toner. + The difference between the amount is 0.12 mg / L or more. In addition, the above NH4 + The amount of NH4 detected when the filtrate was analyzed by ion chromatography after weighing 0.5 g of the fluorescent toner or the non-fluorescent toner and adding it to 100 g of ion-exchanged water at 30°C ± 1°C and dispersing it by ultrasonic waves for 30 minutes and then filtering was determined. + The quantity is:

[0017] Conventionally, when a two-color image is created using a fluorescent toner with high brightness, such as a fluorescent toner containing a fluorescent colorant and having a brightness of 75 or more, and a non-fluorescent toner, the fluorescent intensity of the image obtained varies greatly between areas where the fluorescent toner has an upper layer of non-fluorescent toner and areas where it does not. This has led to the problem that the fluorescent intensity changes in areas where the toner arrangement in the two-color image is disrupted (for example, areas where the fluorescent toner and non-fluorescent toner are swapped), resulting in uneven color. In the toner set for developing electrostatic images according to the present embodiment, the amount of NH4 + The amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is 0.05 mg / L or more and 0.30 mg / L or less. + and the amount of NH4 on the surface of the non-fluorescent toner. + The difference between the amount of NH4 on the toner surface is 0.12 mg / L or more. +It is presumed that the amount of the fluorescent toner acts as a factor for controlling the hydrophilicity / hydrophobicity of the toner surface, and by creating a difference in the hydrophilicity / hydrophobicity of the surface between the fluorescent toner and the non-fluorescent toner, it is possible to suppress mixing of the fluorescent toner and the non-fluorescent toner, resulting in excellent suppression of color unevenness in the resulting image.

[0018] The configuration of the toner set for developing electrostatic images according to this embodiment will be described in detail below.

[0019] [NH4 on the surface of fluorescent or non-fluorescent toner + amount of NH4 on the surface of the fluorescent toner + The amount is 0.05 mg / L or more and 0.30 mg / L or less, and from the viewpoint of suppressing color unevenness in the obtained image (hereinafter also simply referred to as "color unevenness suppression"), it is preferably 0.08 mg / L or more and 0.25 mg / L or less, and more preferably 0.10 mg / L or more and 0.20 mg / L or less.

[0020] NH4 on the surface of the non-fluorescent toner + From the viewpoint of suppressing color unevenness, the amount of is preferably 0.20 mg / L or more and 1.00 mg / L or less, more preferably 0.25 mg / L or more and 0.50 mg / L or less, even more preferably 0.28 mg / L or more and 0.45 mg / L or less, and particularly preferably 0.30 mg / L or more and 0.40 mg / L or less.

[0021] NH4 on the surface of the fluorescent toner or non-fluorescent toner in this embodiment + The amount of NH4 ions detected when the filtrate is analyzed by ion chromatography is measured. + Measure the amount of Specifically, the NH4 + The amount is measured as follows: First, 0.5 g of the toner to be measured is weighed and dispersed in 100 g of ion-exchanged water to which 0.1 g of a nonionic surfactant (Nonipol 10 manufactured by Sanyo Chemical Industries, Ltd.), equivalent to 20% of the toner solids content, has been added, and the toner is dispersed for 30 minutes using an ultrasonic disperser in a thermostatic chamber controlled at 30°C ± 1°C. The liquid after ultrasonic vibration is subjected to solid-liquid separation by suction filtration to remove solid toner, and the obtained filtrate is measured by ion chromatography using an ICS-2000 manufactured by Nippon Dionex Co., Ltd. under the following conditions. Cation separation column: Nippon Dionex Co., Ltd., IonPacCS12A Cation guard column: Nippon Dionex Co., Ltd., IonPacCG12A Eluent: 20 mM methanesulfonic acid Flow rate: 1ml / min Temperature: 35℃ Detection method: Electrical conductivity method (suppressor type)

[0022] [NH4 on the surface of fluorescent toner + The amount of NH4 on the surface of non-fluorescent toner + [difference from the amount of NH4 on the surface of the fluorescent toner as measured by ion chromatography + and the amount of NH4 on the surface of the non-fluorescent toner. + The difference between the amount of the ammonium salt and the amount of the ammonium salt is 0.12 mg / L or more, and from the viewpoint of suppressing color unevenness, it is preferably 0.15 mg / L or more, more preferably 0.15 mg / L or more and 0.30 mg / L or less, and particularly preferably 0.17 mg / L or more and 0.25 mg / L or less.

[0023] NH4 on the surface of fluorescent and non-fluorescent toners + There is no particular limitation on the method for adjusting the amount of NH4 + Examples of the method include a method of adding a source such as an ammonium salt compound, or ammonia and an acid.

[0024] [Fluorescent Toner and Non-Fluorescent Toner] The toner set for developing electrostatic images according to this embodiment includes a fluorescent toner that contains a fluorescent colorant and has a brightness of 75 or more, and a non-fluorescent toner that does not contain a fluorescent colorant. Hereinafter, unless otherwise specified, the term "toner" refers to both fluorescent toner and non-fluorescent toner, and the term "toner particles" refers to both fluorescent toner particles and non-fluorescent toner particles.

[0025] The brightness of the fluorescent toner is 75 or more, and from the viewpoint of further exerting the effects of this embodiment, it is preferably 75 or more and 100 or less, and more preferably 79 or more and 97 or less. Furthermore, in order to maximize the effects of this embodiment, the difference between the brightness of the fluorescent toner and the brightness of the non-fluorescent toner (brightness of the fluorescent toner - brightness of the non-fluorescent toner) is preferably 20 or more, and more preferably 25 or more. There is no particular upper limit, and it is sufficient if it is 100 or less.

[0026] In this embodiment, the brightness of the toner is measured by the following method. A modified ColorPress1000 (FUJIFILM Innovation Co., Ltd.) was prepared as an image forming apparatus for forming an image for evaluation, and the developer was placed in a developing device, and the toner was placed in a toner cartridge. A4 size coated paper (OS coated paper, 127 g / m 2 , Fujifilm Innovation Co., Ltd.) on a single-color solid image (density 100%, size 5cm x 5cm, toner amount 4.0g / m 2 The fixing temperature is 180°C. Using a reflectance spectrodensitometer X-Rite 939 (aperture diameter 4 mm, manufactured by X-Rite Co., Ltd.), CIE1976L was measured at 10 points within the solid image. * a * b * L in color space * Measure the value and L * The average value is calculated and used as the brightness.

[0027] Toner particles The fluorescent toner preferably has toner particles that include a fluorescent colorant. The toner particles in the fluorescent toner contain a fluorescent colorant and a binder resin, and may also contain a release agent and other additives as required. Non-fluorescent toner preferably has toner particles that include a colorant other than a fluorescent colorant. The toner particles in the non-fluorescent toner contain a colorant other than the fluorescent colorant, a binder resin, and, if necessary, a release agent and other additives.

[0028] <Fluorescent colorants> Fluorescent toner includes a fluorescent colorant. Additionally, non-fluorescent toner does not contain fluorescent colorants. The fluorescent colorant may be any colorant that exhibits fluorescence, but is preferably a colorant that exhibits fluorescence in the visible light region (wavelengths of 380 nm or more and 760 nm or less). The light that excites the fluorescent colorant is not particularly limited, but preferably contains at least visible light or ultraviolet light, and more preferably contains at least ultraviolet light. Furthermore, the fluorescent colorant may be either a fluorescent pigment or a fluorescent dye, but is preferably a fluorescent pigment. In this embodiment, a "pigment" is a colorant whose solubility in 100 g of water at 23°C and in 100 g of cyclohexanone at 23°C is less than 0.1 g, and a "dye" is a colorant whose solubility in 100 g of water at 23°C or in 100 g of cyclohexanone at 23°C is 0.1 g or more.

[0029] The color of the fluorescent colorant is not particularly limited and may be selected appropriately as desired. Examples of fluorescent colorants include fluorescent pink colorants, fluorescent red colorants, fluorescent orange colorants, fluorescent yellow colorants, fluorescent green colorants, and fluorescent purple colorants. Among these, a fluorescent pink colorant, a fluorescent red colorant, a fluorescent orange colorant, a fluorescent yellow colorant, or a fluorescent green colorant is preferred, a fluorescent pink colorant, a fluorescent yellow colorant, or a fluorescent green colorant is more preferred, and a fluorescent yellow colorant is even more preferred. Among these, from the viewpoint of further exerting the effects of this embodiment, it is particularly preferable that the fluorescent colorant is an azomethine fluorescent pigment having a fluorescent peak wavelength in the wavelength region of 500 nm or more and 550 nm or less of the fluorescent spectrum.

[0030] The fluorescent peak wavelength of the fluorescent colorant in terms of spectral reflectance can be appropriately selected depending on the desired color. For example, if a fluorescent yellow color is desired, the fluorescent peak wavelength is preferably 500 nm or more and 550 nm or less. The fluorescent peak wavelength is measured by molding the fluorescent colorant into a disk shape and using a spectrophotometer eXact (registered trademark) (manufactured by X-rite). An example of the spectrum for each fluorescent color is shown below. The vertical axis represents the fluorescence intensity, and the horizontal axis represents the wavelength. Note that "mμ" = "nm."

[0031] [ka]

[0032] As the fluorescent colorant, known fluorescent colorants can be used, and specific examples thereof include CI Pigment Yellow 101, Basic Red 1 (Rhodamine 6G), Basic Red 1:1, Basic Red 2, Basic Red 12, Basic Red 13, Basic Red 14, Basic Red 15, Basic Red 36, Basic Violet 7, Basic Violet 10 (Rhodamine B), Basic Violet 11 (Rhodamine 3B), Basic Violet 11:1 (Rhodamine A), Basic Violet 15, Basic Violet 16, Basic Violet 27, Pigment Yellow 101, Basic Yellow 1, Basic Yellow 2, Basic Yellow 9, Basic Yellow 24, Basic Yellow 40, Basic Orange 15, Basic Orange 22, Basic Blue 1, Basic Blue 3, Basic Blue 7, Basic Blue 9, Basic Blue 45, Basic Green 1, Acid Yellow 3, and Acid Yellow. 7, Acid Yellow 73, Acid Yellow 87, Acid Yellow 184, Acid Yellow 245, Acid Yellow 250, Acid Red 51, Acid Red 52, Acid Red 57, Acid Red 77, Acid Red 87, Acid Red 89, Acid Red 92, Acid Blue 9, Acid Black 2, Solvent Yellow 43, Solvent Yellow 44, Solvent Yellow 85, Solvent Yellow 98, Solvent Yellow 116, Solvent Yellow 131, Solvent Yellow 145, Solvent Yellow 160:1, Solvent Yellow 172, Solvent Yellow 185, Solvent Yellow 195, Solvent Yellow 196, Solvent Orange 63, Solvent Orange112, Solvent Red 49, Solvent Red 149, Solvent Red 175, Solvent Red 196, Solvent Red 197, Solvent Blue 5, Solvent Green 5, Solvent Green 7, Direct Yellow 27, Direct Yellow 85, Direct Yellow 96, Direct Orange 8, Direct Red 2, Direct Red 9, Direct Blue 22, Direct Blue 199, Direct Green 6, Disperse Yellow 11, Disperse Yellow 82, Disperse Yellow 139, Disperse Yellow 184, Disperse Yellow 186, Disperse Yellow 199, Disperse Yellow 202, Disperse Yellow 232, Disperse Orange 11, Disperse Orange 32, Disperse Red 58, Disperse Red 274, Disperse Red 277, Disperse Red 303, Disperse Blue 7, Reactive Yellow 78, Vat Red 41, etc.

[0033] The fluorescent toner may contain one type of fluorescent colorant alone or two or more types in combination. From the viewpoints of fluorescence intensity and image granularity, the content of the fluorescent colorant is preferably 1% by mass to 15% by mass, more preferably 3% by mass to 10% by mass, and particularly preferably 5% by mass to 8% by mass, based on the total toner particles when a pigment is used as the fluorescent colorant. When a dye is used as the fluorescent colorant, the content is preferably 0.05% by mass to 2% by mass, more preferably 0.1% by mass to 1.5% by mass, and particularly preferably 0.5% by mass to 1.0% by mass, based on the total toner particles.

[0034] <Colorants other than fluorescent colorants> The fluorescent toner may contain colorants other than fluorescent colorants, and preferably contains non-fluorescent pigments. Furthermore, the non-fluorescent toner preferably contains a colorant other than the fluorescent colorant. Specific examples of colorants other than fluorescent colorants include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 21, 22, 23, 31, 32, 38, 41, 48, 48:1, and 48: 2, 48:3, 48:4, 49, 52, 53:1, 54, 57:1, 58, 60:1, 63, 64:1, 68, 81:1, 81:4, 83, 88, 89, 112, 114, 122, 123, 144, 146, 149, 150, 166, 170 , 176, 177, 178, 179, 184, 185, 187, 202, 206, 207, 208, 209, 210, 220, 221, 238, 242, 245, 253, 254, 255, 256, 258, 264, 266, 269, 28 2nd class, magenta pigments such as Pigment Violet 19, CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122, CI Disperse Red 9, CIMagenta dyes such as Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40, red iron oxide, cadmium red, red lead, mercury sulfide, permanent red 4R, lithol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rotamine lake B, alizarin lake, brilliant carmine 3B, carbon black, black Examples of suitable pigments include various pigments such as Benzidine Yellow, Hansa Yellow, Benzidine Yellow, Threne Yellow, Quinoline Yellow, Pigment Yellow, Permanent Orange GTR, Pyrazolone Orange, Balkan Orange, Brilliant Carmine 3B, Brilliant Carmine 6B, DuPont Oil Red, Lake Red C, Aniline Blue, Ultramarine Blue, Chalco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, and Malachite Green Oxalate, as well as various dyes. The colorants other than the fluorescent colorant may be used alone or in combination of two or more.

[0035] The colorants other than the fluorescent colorant may be surface-treated as needed, or may be used in combination with a dispersant. Furthermore, a plurality of colorants may be used in combination.

[0036] The non-fluorescent pigment in the fluorescent toner preferably has a reflection peak wavelength in the wavelength range of 480 nm to 540 nm in the reflection spectrum. The reflection peak wavelength is measured by molding the non-fluorescent pigment into a disk and using a spectrophotometer eXact (registered trademark) (manufactured by X-rite). It is particularly preferred that the fluorescent colorant in the fluorescent toner contains an azomethine fluorescent pigment having a peak fluorescence wavelength in the wavelength region of 500 nm to 550 nm in the fluorescent spectrum, and the non-fluorescent pigment in the fluorescent toner contains a non-fluorescent pigment having a peak reflection wavelength in the wavelength region of 480 nm to 540 nm in the reflectance spectrum.

[0037] The content of colorants other than fluorescent colorants is, for example, preferably 1% by mass to 30% by mass, more preferably 3% by mass to 15% by mass, based on the total amount of non-fluorescent toner particles. The content of colorants other than fluorescent colorants is preferably 0.1% by mass to 30% by mass, more preferably 0.5% by mass to 15% by mass, based on the total fluorescent toner particles, from the viewpoint of fluorescence intensity and color reproducibility.

[0038] <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 (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.

[0039] 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. However, the content of the crystalline polyester resin is preferably in the range of 2% by mass to 40% by mass (preferably 5% by mass to 25% by mass) relative to the total binder resin. From the viewpoint of low-temperature fixability and heat storage stability, the binder resin preferably contains a crystalline resin, and more preferably contains a crystalline polyester resin.

[0040] The "crystalline" nature of a resin refers to the presence of a clear endothermic peak rather than a stepwise change in endothermic heat 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. On the other hand, 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.

[0041] Amorphous polyester resin Examples of the amorphous polyester resin include a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. Note that, as the amorphous polyester resin, a commercially available product or a synthesized product may be used.

[0042] 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.

[0043] 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.

[0044] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, and more preferably 50°C or higher and 65°C or lower. The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), more specifically, from the "extrapolated glass transition onset temperature" described in JIS K 7121-1987 "Method for measuring transition temperatures of plastics."

[0045] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less. The weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). Molecular weight measurements by GPC are performed using a Tosoh Corporation GPC HLC-8120GPC measuring instrument and a Tosoh Corporation TSKgel SuperHM-M (15 cm) column in tetrahydrofuran (THF) as a 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.

[0046] The amorphous polyester resin can be obtained by a known manufacturing method, for example, by carrying out the reaction at a polymerization temperature of 180°C or higher and 230°C or lower, reducing the pressure in the reaction system as necessary, and removing water and alcohol generated during the condensation. If the raw material monomer is not soluble or compatible at the reaction temperature, a high-boiling solvent may be added as a solubilizer to dissolve it. In this case, the polycondensation reaction is carried out while distilling off the solubilizer. If a monomer with poor compatibility is present, it is advisable to first condense the poorly compatible monomer with the acid or alcohol to be polycondensed, and then polycondense the monomer with the main component.

[0047] Crystalline polyester resin The crystalline polyester resin may be, for example, a polycondensate of a polycarboxylic acid and a polyhydric alcohol. Note that, as the crystalline polyester resin, a commercially available product or a synthesized product may be used. Here, the crystalline polyester resin is preferably a polycondensate using a polymerizable monomer having a linear aliphatic group rather than a polymerizable monomer having an aromatic group, since it easily forms a crystalline structure.

[0048] 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, or lower alkyl esters thereof (for example, 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.

[0049] 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.

[0050] Here, the polyhydric alcohol has an aliphatic diol content of 80 mol % or more, preferably 90 mol % or more.

[0051] 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) by using the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperatures of plastics."

[0052] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0053] The crystalline polyester resin can be obtained by a known manufacturing method, for example, in the same manner as the amorphous polyester.

[0054] The content of the binder resin is, for example, preferably 40% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and even more preferably 60% by mass to 85% by mass, based on the total mass of the toner particles.

[0055] <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.

[0056] The melting temperature of the release agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) by using the "melting peak temperature" as described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperatures of plastics."

[0057] The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, based on the total mass of the toner particles.

[0058] <Other additives> Examples of other additives include well-known additives such as magnetic materials, charge control agents, inorganic powders, etc. These additives are contained in the toner particles as internal additives.

[0059] <Characteristics of toner particles> The toner particles may be toner particles of a single layer structure, or may be toner particles of a so-called core-shell structure composed of a core part (core particle) and a coating layer (shell layer) that coats the core part.

[0060] The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

[0061] The toner particles, various average particle sizes of the toner, and various particle size distribution indices are measured using a Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte is measured using an ISOTON-II (manufactured by Beckman Coulter). For the measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this is then added to 100 ml to 150 ml of the electrolyte. The electrolyte solution containing the suspended sample is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with a particle size range of 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 50,000. Based on the particle size distribution measured, cumulative distributions of volume and number are drawn for each divided particle size range (channel) from the smallest diameter side, and the particle size at 16% of the cumulative total is defined as the volume particle size D16v, the number particle size D16p, the particle size at 50% of the cumulative total as the volume average particle size D50v, the cumulative number average particle size D50p, and the particle size at 84% of the cumulative total as the volume particle size D84v and the number particle size D84p. Using these, the volumetric particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 , the number particle size distribution index (GSDp) is (D84p / D16p) 1 / 2 It is calculated as:

[0062] The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

[0063] The average circularity of toner particles is calculated by (circular equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the particle projected image)]. Specifically, this value is measured by the following method. First, the toner particles to be measured are sucked and collected, forming a flat flow, and a still image of the particles is captured by instantaneously activating a strobe light, and the particle image is analyzed using a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation).The number of samples to be sampled when calculating the average circularity is 3,500. When the toner contains external additives, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additives have been removed.

[0064] [[External additives]] Examples of external additives include inorganic particles, such as SiO2, 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.

[0065] The surfaces of inorganic particles as 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 coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobic treatment agent is preferably, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

[0066] Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and particles of fluorine-based polymers).

[0067] The amount of the external additive added is, for example, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less, based on the toner particles.

[0068] From the viewpoint of suppressing color unevenness, the volume average particle size of the fluorescent toner is preferably larger than the volume average particle size of the non-fluorescent toner. From the viewpoint of suppressing color unevenness, the volume average particle size of the fluorescent toner is preferably 4.5 μm to 7.0 μm, more preferably 5.0 μm to 6.5 μm, and particularly preferably 5.4 μm to 6.2 μm. From the viewpoint of suppressing color unevenness, the volume average particle size of the non-fluorescent toner is preferably 3.5 μm or more and 6.0 μm or less, more preferably 4.0 μm or more and 5.5 μm or less, and particularly preferably 4.4 μm or more and 5.0 μm or less.

[0069] [Toner manufacturing method] The toner can be obtained by producing toner particles and then externally adding an external additive to the toner particles.

[0070] The toner particles may be produced by any of a dry production method (for example, a kneading and pulverization method) and a wet production method (for example, an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method). There are no particular limitations on these production methods, and any known production method may be used. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

[0071] When the toner particles are produced by the aggregation and coalescence method, the following production method is preferred. 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 colorant particle dispersion liquid in which a colorant (e.g., a fluorescent colorant, a colorant other than a fluorescent colorant, etc.) is dispersed (colorant particle dispersion liquid preparation step); a step of aggregating the mixed particles in a mixed dispersion obtained by mixing a resin particle dispersion and a colorant particle dispersion (in a dispersion after mixing other particle dispersions as necessary) 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 to form toner particles (fusion and coalescence step).

[0072] Each step will be described in detail below.

[0073] -Resin particle dispersion preparation process- The resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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, Ltd. LA-700), and the cumulative distribution for the volume of the divided particle size range (channel) is calculated from the smallest particle size side. The particle size at which the cumulative 50% of all particles is obtained is defined as the volume average particle size D50v. The volume average particle sizes of particles in other dispersions are also measured in the same manner.

[0078] 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.

[0079] In addition, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the binder resin particle dispersion. That is, the volume average particle diameter, dispersion medium, dispersion method, and particle content of the particles in the binder resin particle dispersion are the same as those of the colorant particles dispersed in the colorant particle dispersion. The same applies to the release agent particles dispersed in the release agent particle dispersion liquid.

[0080] -Agglomerated particle formation process- A resin particle dispersion, a colorant particle dispersion (for example, a fluorescent colorant dispersion and a non-fluorescent pigment dispersion), and a release agent particle dispersion are mixed together, and in the mixed dispersion, the resin particles, the fluorescent organic pigment, the non-fluorescent organic pigment, and the release agent particles are hetero-aggregated to form aggregated particles containing the resin particles, the fluorescent organic pigment, the non-fluorescent organic pigment, and the release agent particles, and having a diameter close to that of the target toner particles. In the process of forming aggregated particles, an ammonium salt compound or ammonia and an acid such as NH4 + It is preferred to add a source of NH4 + The source is preferably an ammonium salt compound, more preferably ammonium sulfate or ammonium chloride.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] -Fusion / unification process- Next, the aggregated particle dispersion liquid in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10°C to 30°C higher than the glass transition temperature of the resin particles), to fuse and coalesce the aggregated particles and form toner particles.

[0085] Through the above steps, toner particles are obtained. After obtaining an aggregated particle dispersion in which aggregated particles are dispersed, the toner particles may be produced through the following steps: a step of further mixing the aggregated particle dispersion with a resin particle dispersion in which resin particles are dispersed, and aggregating the aggregated particles so that further resin particles adhere to the surfaces of the aggregated particles to form second aggregated particles; and a step of heating the second aggregated particle dispersion in which the second aggregated particles are dispersed, and fusing and coalescing the second aggregated particles to form toner particles having a core-shell structure.

[0086] After the fusion and coalescence process is completed, the toner particles in the dispersion are subjected to a known washing process, solid-liquid separation process, and drying process to obtain dried 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, flash drying, fluidized drying, vibration-type fluidized drying, etc.

[0087] The toner according to this embodiment is produced by, for example, adding an external additive to the obtained dry toner particles and mixing them. The mixing can be carried out using, for example, a V blender, a Henschel mixer, a Loedige mixer, etc. Furthermore, if necessary, coarse particles may be removed from the toner using a vibrating sieve, an air sieve, etc.

[0088] (Electrostatic image developer set) The electrostatic image developer set according to this embodiment includes a first electrostatic image developer containing the fluorescent toner from the toner set for developing electrostatic images according to this embodiment, and a second electrostatic image developer containing the non-fluorescent toner from the toner set for developing electrostatic images according to this embodiment. In the electrostatic image developer set according to this embodiment, each developer may be a one-component developer containing only the toner in the toner set according to this embodiment, or may be a two-component developer in which the toner is mixed with a carrier.

[0089] The carrier is not particularly limited, and known carriers can be used, such as 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 type carrier and the resin impregnated type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and the surface of the core material is coated with a resin.

[0090] Examples of magnetic powder include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0091] 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 other additives such as conductive particles. Examples of conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0092] To coat the surface of the core material with a resin, 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 can be used. The solvent is not particularly limited and may be selected taking into consideration the type of resin used, its suitability for application, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer; a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material; a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air; and a kneader coater method in which the core material of the carrier and the solution for forming a coating layer are mixed in a kneader coater and then the solvent is removed.

[0093] 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.

[0094] (Image forming device, image forming method) An image forming apparatus and an image forming method according to this embodiment will be described. The image forming apparatus according to this embodiment includes a first image forming means for forming a first image using the fluorescent toner of the toner set for developing electrostatic images according to this embodiment, a second image forming means for forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images according to this embodiment, a transfer means for transferring the first image and the second image onto a recording medium, and a fixing means for fixing the first image and the second image onto the recording medium.

[0095] The image forming apparatus according to the present embodiment may be configured to include, as first or second image forming means, image forming means each having 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 surface of the charged image carrier, and a developing means for developing the electrostatic image formed on the surface of the image carrier with an electrostatic image developer into a toner image. In addition, the image forming apparatus according to the present embodiment may have a configuration including an image carrier, a charging means for charging the surface of the image carrier, an electrostatic image forming means for forming an electrostatic image on the charged surface of the image carrier, and first and second developing means as first and second image forming means for developing the electrostatic image formed on the surface of the image carrier with an electrostatic image developer into a toner image.

[0096] In the image forming apparatus according to this embodiment, an image forming method (the image forming method according to this embodiment) is carried out, which includes a first image forming process of forming a first image using the fluorescent toner of the toner set for developing electrostatic images according to this embodiment, a second image forming process of forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images according to this embodiment, a transfer process of transferring the first image and the second image onto a recording medium, and a fixing process of fixing the first image and the second image onto the recording medium.

[0097] The image forming apparatus according to this embodiment may be a known image forming apparatus such as a direct transfer type apparatus that transfers a toner image (in this embodiment, a first image and a second image) formed on the surface of an image carrier directly to a recording medium; an intermediate transfer type apparatus that performs a primary transfer of a toner image formed on the surface of an image carrier to the surface of an intermediate transfer carrier, and then performs a secondary transfer of the toner image transferred to the surface of the intermediate transfer carrier 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; or 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. In the case of an intermediate transfer type device, 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 which primarily transfers the toner image formed on the surface of the image carrier onto the surface of the intermediate transfer body, and a secondary transfer means which secondarily transfers the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

[0098] In order to maximize the effect of this embodiment, it is preferable to have at least a portion where the fluorescent toner is the lower layer and the non-fluorescent toner is the upper layer when fixed.

[0099] In the image forming apparatus according to the present embodiment, for example, a 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 equipped with developing means that accommodates the electrostatic image developer set according to the present embodiment is preferably used.

[0100] An example of an image forming apparatus will be described below. In the following description, the main parts shown in the drawings will be described, and the description of the rest will be omitted.

[0101] FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus used in this embodiment, and is a diagram showing a five-tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in FIG. 1 includes first through fifth electrophotographic image forming units 150Y, 150M, 150C, 150K, and 150B (image forming means) that output images in yellow (Y), magenta (M), cyan (C), black (K), and fluorescent (B) colors based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 150Y, 150M, 150C, 150K, and 150B are arranged side by side horizontally spaced a predetermined distance apart from one another. These units 150Y, 150M, 150C, 150K, and 150B may be process cartridges that are detachably attached to the image forming apparatus.

[0102] An intermediate transfer belt (an example of an intermediate transfer body) 133 extends below each of the units 150Y, 150M, 150C, 150K, and 150B. The intermediate transfer belt 133 is wound around a drive roll 113, a support roll 112, and an opposing roll 114, which are in contact with the inner surface of the intermediate transfer belt 133, and runs in a direction from the first unit 150Y to the fifth unit 150B (the direction of arrow B in FIG. 1). An intermediate transfer body cleaning device 116 is provided on the image bearing surface side of the intermediate transfer belt 133, facing the drive roll 113. Furthermore, a voltage application device 160 is provided upstream of the intermediate transfer body cleaning device 116 in the rotation direction of the intermediate transfer belt 133, which generates a potential difference between the intermediate transfer belt 133 and the supporting roll 113, thereby generating an electric field between the intermediate transfer belt 133 and the intermediate transfer body cleaning device 116. The developing devices (examples of developing means) 120Y, 120M, 120C, 120K, and 120B of each unit 150Y, 150M, 150C, 150K, and 150B are supplied with yellow, magenta, cyan, black, and fluorescent toner contained in toner cartridges 140Y, 140M, 140C, 140K, and 140B, respectively.

[0103] The first to fifth units 150Y, 150M, 150C, 150K, and 150B have the same configuration, operation, and function, so here we will explain the first unit 150Y, which forms a yellow image and is arranged upstream in the direction of travel of the intermediate transfer belt, as a representative.

[0104] The first unit 150Y has a photoconductor 111Y that acts as an image carrier. Around the photoconductor 111Y, there are arranged in this order: a charging roll (an example of a charging means) 118Y that charges the surface of the photoconductor 111Y to a predetermined potential; an exposure device (an example of an electrostatic image forming means) 119Y that exposes the charged surface to a laser beam based on a color-separated image signal to form an electrostatic image; a developing device (an example of a developing means) 120Y that supplies toner to the electrostatic image to develop it; a primary transfer roll (an example of a primary transfer means) 117Y that transfers the developed toner image onto the intermediate transfer belt 133; and a photoconductor cleaning device (an example of a cleaning means) 115Y that removes toner remaining on the surface of the photoconductor 111Y after the primary transfer. The primary transfer roll 117Y is disposed inside the intermediate transfer belt 133 and is provided at a position facing the photosensitive member 111Y. A bias power supply (not shown) that applies a primary transfer bias is connected to the primary transfer rolls 117Y, 117M, 117C, 117K, and 117B of each 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).

[0105] The operation of forming a yellow image in first unit 150Y will be described below. First, prior to operation, the surface of the photosensitive member 111Y is charged to a potential of −600V to −800V by the charging roll 118Y. The photoconductor 111Y has conductivity (for example, a volume resistivity of 1×10 at 20° C. -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate with a resistivity of Ωcm or less. This photosensitive layer normally has a high resistance (the resistance of ordinary resins), but when irradiated with a laser beam, the resistivity of the irradiated portion changes. Therefore, the charged surface of the photosensitive element 111Y is irradiated with a laser beam from the exposure device 119Y in accordance with image data for yellow sent from a control unit (not shown). As a result, an electrostatic charge image of a yellow image pattern is formed on the surface of the photosensitive element 111Y.

[0106] An electrostatic image is an image formed on the surface of the photosensitive element 111Y 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 119Y, causing the charged charges on the surface of the photosensitive element 111Y to flow, while the charges remain in the portions not irradiated by the laser beam. The electrostatic image formed on the photoconductor 111Y rotates to a predetermined development position as the photoconductor 111Y travels, where the electrostatic image on the photoconductor 111Y is developed into a toner image by the developing device 120Y and made visible.

[0107] The developing device 120Y contains an electrostatic image developer containing, for example, at least yellow toner and a carrier. The yellow toner is frictionally charged by being stirred inside the developing device 120Y, and is held on a developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the charge on the photoconductor 111Y. As the surface of the photoconductor 111Y passes through the developing device 120Y, the yellow toner electrostatically adheres to the discharged latent image portion on the surface of the photoconductor 111Y, and the latent image is developed with the yellow toner. The photoconductor 111Y on which the yellow toner image has been formed continues to travel at a predetermined speed, and the toner image developed on the photoconductor 111Y is transported to a predetermined primary transfer position.

[0108] When the yellow toner image on the photoconductor 111Y is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 117Y, and an electrostatic force from the photoconductor 111Y toward the primary transfer roll 117Y acts on the toner image, causing the toner image on the photoconductor 111Y to be transferred onto the intermediate transfer belt 133. The transfer bias applied at this time has a (+) polarity opposite to the (-) polarity of the toner, and is controlled to, for example, +10 μA by a control unit (not shown) in the first unit 150Y. On the other hand, the toner remaining on the photoconductor 111Y is removed and collected by the photoconductor cleaning device 115Y.

[0109] The primary transfer biases applied to the primary transfer rolls 117M, 117C, 117K, and 117B of the second unit 150M and subsequent units are also controlled in accordance with the first unit. In this way, the intermediate transfer belt 133 onto which the yellow toner image has been transferred by the first unit 150Y is conveyed sequentially through the second to fifth units 150M, 150C, 150K, and 150B, and the toner images of each color are superimposed and transferred.

[0110] The intermediate transfer belt 133 onto which the five-color toner images have been multiplex-transferred through the first to fifth units reaches a secondary transfer section made up of the intermediate transfer belt 133, an opposing roll 114 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer means) 134 arranged on the image bearing surface side of the intermediate transfer belt 133. Meanwhile, recording paper (an example of a recording medium) P is fed via a supply mechanism into the gap between the secondary transfer roll 134 and the intermediate transfer belt 133 at a predetermined timing, and a secondary transfer bias is applied to the opposing roll 114. 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 133 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 133 is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to resistance detected by resistance detection means (not shown) that detects resistance in the secondary transfer section, and is voltage-controlled.

[0111] Thereafter, the recording paper P is sent to a pressure contact portion (nip portion) of a pair of fixing rolls in a fixing device (an example of fixing means) 135, where the toner image is fixed onto the recording paper P, forming a fixed image.

[0112] 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.

[0113] 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.

[0114] 1 is an image forming apparatus having a configuration in which toner cartridges 140Y, 140M, 140C, 140K, and 140B are detachably attached, and developing devices 120Y, 120M, 120C, 120K, and 120B are connected to toner cartridges corresponding to the respective developing devices (colors) via toner supply pipes (not shown). When the toner contained in a toner cartridge runs low, the toner cartridge is replaced.

[0115] <Process cartridge / toner cartridge set> The process cartridge of this embodiment is a process cartridge that is detachably attached to an image forming apparatus and includes a first developing means that contains a first electrostatic image developer of the electrostatic image developer set, and a second developing means that contains the second electrostatic image developer of the electrostatic image developer set of this embodiment.

[0116] The configuration is not limited to the above, and may also include a developing device 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.

[0117] An example of a process cartridge will be shown below, but the present invention is not limited to this. Note that only the main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0118] FIG. 2 is a schematic diagram showing the configuration of a process cartridge used in this embodiment. The process cartridge 200 shown in FIG. 2 is configured to integrally combine and hold a photosensitive member 207 (an example of an image carrier), a charging roll 208 (an example of a charging means) provided around the photosensitive member 207, a developing device 211 (an example of a developing means), and a photosensitive member cleaning device 213 (an example of a cleaning means), which are combined and held together by a housing 217 provided with, for example, mounting rails 216 and an opening 218 for exposure, to form a cartridge. In FIG. 2, 209 denotes an exposure device (an example of an electrostatic image forming means), 212 denotes a primary transfer roll (an example of a primary transfer means), 220 denotes an intermediate transfer belt (an example of an intermediate transfer body), 222 denotes a drive roll (an example of an intermediate transfer body de-electrification means) that also serves as an intermediate transfer belt de-electrification means, 224 denotes a support roll, 226 denotes a secondary transfer roll (an example of a secondary transfer means), 228 denotes a fixing device (an example of a fixing means), and 300 denotes recording paper (an example of a recording medium). [Example]

[0119] 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.

[0120] Example 1 [Preparation of fluorescent toner (toner 1)] <Preparation of Fluorescent Pigment Particle Dispersion (1)> Fluorescent yellow pigment (CI Pigment Yellow 101, Lumogen Yellow S 0795, BASF Japan Ltd., fluorescence peak wavelength: 530 nm): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 20 parts (solids concentration 20%) Ion-exchanged water: 200 parts The above components were mixed and pulverized to 0.5 μm using a continuous key mill (KMC-3, manufactured by Inoue Seisakusho Co., Ltd.), and the solid content was adjusted to 20% by mass to obtain fluorescent pigment particle dispersion (1).

[0121] <Preparation of Colorant Particle Dispersion (2)> Green pigment (CI Pigment Green 36, Fastogen Green 2YK, DIC Corporation, peak reflection wavelength: 510 nm): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 20 parts (solids concentration 20%) Ion-exchanged water: 200 parts The above components were mixed and pulverized to 0.2 μm using a continuous key mill (KMC-3, manufactured by Inoue Seisakusho Co., Ltd.), and the solid content was adjusted to 20% by mass to obtain colorant particle dispersion (2).

[0122] <Preparation of Resin Particle Dispersion (1)> Terephthalic acid: 30 parts by mole Fumaric acid: 70 parts by mole Bisphenol A ethylene oxide adduct: 5 mole parts Bisphenol A propylene oxide adduct: 95 parts by mole The above materials were placed in a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column, and the temperature was raised to 220°C over 1 hour. Then, 1 part of titanium tetraethoxide was added per 100 parts of the materials. The temperature was raised to 230°C over 30 minutes while distilling off the resulting water. The dehydration condensation reaction was continued at this temperature for 1 hour, and the reaction mixture was then cooled. This yielded a polyester resin with a weight-average molecular weight of 18,000 and a glass transition temperature of 60°C. A vessel equipped with a temperature control device and a nitrogen purge device was charged with 40 parts of ethyl acetate and 25 parts of 2-butanol to form a mixed solvent. Then, 100 parts of polyester resin was gradually added and dissolved. 0.4 parts by mass of a 25% by mass aqueous solution of sodium hydroxide was added and stirred for 30 minutes. The atmosphere inside the 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. After the addition was completed, the temperature was returned to room temperature (20°C to 25°C), and dry nitrogen was bubbled through the mixture for 48 hours while stirring to obtain a resin particle dispersion in which the ethyl acetate and 2-butanol concentrations were reduced to 1,000 ppm or less. Ion-exchanged water was added to the resin particle dispersion to adjust the solids content to 20% by mass, yielding Resin Particle Dispersion (1).

[0123] <Preparation of Release Agent Particle Dispersion (1)> Paraffin wax (Nippon Seiro Co., Ltd., HNP-9): 100 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water: 350 parts The above materials were mixed and heated to 100°C, dispersed using a homogenizer (manufactured by IKA, trade name Ultra Turrax T50), and then dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin) to obtain a release agent particle dispersion (1) (solid content 20% by mass) in which release agent particles with a volume average particle size of 200 nm were dispersed.

[0124] <Preparation of Toner Particles (1)> ·Resin particle dispersion (1): 400 parts Fluorescent pigment particle dispersion (1): 50 parts Colorant particle dispersion (2): 25 parts Release agent particle dispersion (1): 25 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts Ammonium sulfate (Fujifilm Wako Pure Chemical Industries, Ltd.): 0.05 parts The above materials were placed in a round stainless steel flask, and 0.1 N (=mol / L) nitric acid was added to adjust the pH to 3.5. Then, 30 parts of a nitric acid solution containing 10% by weight of polyaluminum chloride were added. The mixture was then dispersed at 30°C using a homogenizer (Ultra Turrax T50, manufactured by IKA Corporation) and heated to 48°C in a heating oil bath and held for 30 minutes. 50 parts of resin particle dispersion (1) was then added and held for 1 hour. A 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and the mixture was then heated to 84°C and held for 2.5 hours. The mixture was then cooled to 20°C at a rate of 20°C / min. The solids were filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles (1). The volume average particle size of toner particles (1) was 5.8 μm.

[0125] <Preparation of Carrier 1> Ferrite particles (average particle size 35 μm): 100 parts Toluene: 14 parts Polymethyl methacrylate (MMA, weight average molecular weight 75,000): 5 parts Carbon black: 0.2 parts (VXC-72, manufactured by Cabot Corporation, volume resistivity: 100 Ω cm or less) The above materials except for the ferrite particles were dispersed in a sand mill to prepare a dispersion liquid, and this dispersion liquid was placed in a vacuum degassing kneader together with the ferrite particles, and dried under reduced pressure while stirring to obtain Carrier 1.

[0126] <Toner Production> 100 parts by mass of the obtained toner particles (1) were mixed and blended with 1.5 parts by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part by mass of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. The mixture was then sieved through a vibrating sieve with 45 μm openings to prepare toner 1 (fluorescent green (G) toner). The volume average particle size of the obtained toner 1 was 5.8 μm.

[0127] <Preparation of Electrostatic Image Developer> 8 parts of Toner 1 and 92 parts of Carrier 1 were mixed in a V blender to prepare Developer 1 (electrostatic image developer).

[0128] [Preparation of non-fluorescent toner (toner 2)] <Preparation of Colorant Particle Dispersion (3)> Cyan pigment (CI Pigment Blue 15:3, LIONOL BLUE FG-7330, manufactured by Toyo Color Co., Ltd.): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 25 parts (solids concentration 20%) Ion-exchanged water: 200 parts The above components were mixed and dispersed for 1 hour using a high-pressure impact disperser (Ultimizer HJP30006, Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion (3) with a volume average particle size of 180 nm and a solid content of 20%.

[0129] <Preparation of Toner Particles (2)> ·Resin particle dispersion (1): 400 parts Colorant particle dispersion (3): 50 parts Release agent particle dispersion (1): 25 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 10 parts Ammonium sulfate (Fujifilm Wako Pure Chemical Industries, Ltd.): 0.10 parts The above materials were placed in a round stainless steel flask, and 0.1 N (=mol / L) nitric acid was added to adjust the pH to 3.5. Then, 30 parts of a nitric acid solution containing 10% by weight of polyaluminum chloride were added. The mixture was then dispersed at 30°C using a homogenizer (Ultra Turrax T50, manufactured by IKA Corporation) and heated to 45°C in a heating oil bath and held for 30 minutes. 50 parts of resin particle dispersion (1) was then added and held for 1 hour. 0.1 N aqueous sodium hydroxide was added to adjust the pH to 8.5, and the mixture was heated to 84°C and held for 2.5 hours. The mixture was then cooled to 20°C at a rate of 20°C / min. The solids were filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles (2). The volume average particle size of toner particles (2) was 4.7 μm.

[0130] <Toner Production> 100 parts by mass of the obtained toner particles (2) were mixed and blended with 1.5 parts by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part by mass of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. The mixture was then sieved through a vibrating sieve with 45 μm openings to prepare toner 2 (cyan toner). The volume average particle size of the obtained toner 2 was 4.7 μm.

[0131] <Preparation of Electrostatic Image Developer> 8 parts of Toner 2 and 92 parts of Carrier 1 were mixed in a V blender to prepare Developer 2 (electrostatic image developer).

[0132] (Examples 2 to 9 and Comparative Examples 1 to 3) The amount of ammonium sulfate used in the preparation of Toner 1 and Toner 2 was adjusted, and the amount of NH4 + Each toner and each developer were prepared in the same manner as in Example 1, except that the amounts were changed to the following.

[0133] Example 10 Each toner and developer was prepared in the same manner as in Example 1, except that, when preparing the fluorescent toner particles, the temperature in the heating step after dispersion using a homogenizer was changed from 48°C to 47°C, the holding time was changed from 30 minutes to 10 minutes, and the volume average particle size of the resulting toner particles was changed to 5.2 μm.

[0134] Example 11 Each toner and developer was prepared in the same manner as in Example 1, except that, when preparing the fluorescent toner particles, the temperature in the heating step after dispersion using a homogenizer was changed from 48°C to 49°C, the holding time was changed from 30 minutes to 45 minutes, and the volume average particle size of the resulting toner particles was changed to 5.2 μm.

[0135] Example 12 Each toner (fluorescent yellow (Y) toner and cyan (Cyan) toner) and each developer were prepared in the same manner as in Example 3, except that, when preparing the toner particles of the fluorescent toner, the colorant particle dispersion (2) was not used and 50 parts of the fluorescent pigment particle dispersion (1) was used.

[0136] Example 13 <Preparation of Colorant Particle Dispersion (4)> Magenta pigment (CI Pigment Red 122, FASTOGEN SUPER MAGENTA R, manufactured by DIC Corporation): 50 parts Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 25 parts (solids concentration 20%) Ion-exchanged water: 200 parts The above components were mixed and dispersed for 1 hour using a high-pressure impact disperser (Ultimizer HJP30006, Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion (4) having a volume average particle size of 160 nm and a solid content of 20%.

[0137] Each toner (fluorescent yellow (Y) toner and magenta toner) and each developer were prepared in the same manner as in Example 8, except that colorant particle dispersion (4) was used instead of colorant particle dispersion (3) when preparing toner particles of a non-fluorescent toner.

[0138] < Surface NH4 + How to measure the amount of The amount of NH4 ions on the toner surface was measured as follows. First, 0.5 g of the toner to be measured was weighed and dispersed in 100 g of ion-exchanged water to which 0.1 g of a nonionic surfactant (Nonipol 10 manufactured by Sanyo Chemical Industries, Ltd.), equivalent to 20% of the toner solid content, had been added, and the mixture was dispersed for 30 minutes using an ultrasonic disperser in a thermostatic chamber controlled at 30°C ± 1°C. The liquid after ultrasonic vibration was subjected to solid-liquid separation by suction filtration to remove the solid toner, and the obtained filtrate was measured by ion chromatography using an ICS-2000 manufactured by Nippon Dionex Co., Ltd. under the following conditions. Cation separation column: Nippon Dionex Co., Ltd., IonPacCS12A Cation guard column: Nippon Dionex Co., Ltd., IonPacCG12A Eluent: 20 mM methanesulfonic acid Flow rate: 1ml / min Temperature: 35℃ Detection method: Electrical conductivity method (suppressor type)

[0139] <Measurement of volume average particle size> The volume average particle size of the toner and toner particles was measured using a Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte was measured using an ISOTON-II (manufactured by Beckman Coulter). For the measurement, 0.5 mg to 50 mg of the measurement sample was added to 2 ml of a 5 mass % aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this was then added to 100 ml to 150 ml of the electrolyte. The electrolyte solution containing the suspended sample is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with a particle size range of 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 50,000. A cumulative distribution of the volume was drawn for each particle size range (channel) divided based on the particle size distribution measured, from the smallest diameter side, and the particle size at 50% of the cumulative distribution was defined as the volume average particle size D50v.

[0140] <Measurement of brightness> -Image formation- A modified Color1000Press (Fuji Xerox Co., Ltd.) was prepared as an image forming apparatus for forming an image for evaluation, and the developer was placed in a developing device, and the toner was placed in a toner cartridge. A4 size coated paper (OS coated paper, 127 g / m 2 , Fujifilm Business Innovation Co., Ltd.) on a single-color solid image (density 100%, size 5cm x 5cm, toner amount 4.0g / m 2 The fixing temperature was 180°C.

[0141] -brightness- Using a reflectance spectrodensitometer X-Rite 939 (aperture diameter 4 mm, X-Rite Co., Ltd.), CIE1976L was measured at 10 points within the solid image. * a * b * L in color space * Measure the value and L * The values ​​were averaged and the brightness was measured.

[0142] <Evaluation of color unevenness suppression> -Image formation- A modified Color1000Press (Fuji Xerox Co., Ltd.) was prepared as an image forming apparatus for forming an image for evaluation, and the developer was placed in a developing device, and the toner was placed in a toner cartridge. A4 size coated paper (OS coated paper, 127 g / m 2 , Fujifilm Business Innovation Co., Ltd.) to create a two-color secondary image (density 100%, size 5cm x 5cm, toner loading amount 4.0g / m 2 The fixing temperature was 180°C.

[0143] -The difference between the maximum and minimum brightness values- The color was measured at 10 random locations using an X-Rite 939 reflection spectrodensitometer, and the difference between the maximum and minimum brightness values ​​was calculated and evaluated according to the following criteria: The smaller the difference between the maximum and minimum brightness values, the better the color unevenness suppression. A: 0.4 or less B: Over 0.4 and 0.8 or less C: Over 0.8

[0144] <Evaluation of Toner Charging Properties> 1.5g of toner and 15g of carrier were weighed and stirred for 5 minutes in a turbular mixer under normal temperature and humidity conditions (20℃ 50%RH), after which the charge amount per unit mass of toner was measured using a blow-off measuring device. The larger the charge amount, the better the charging properties.

[0145] The evaluation results are summarized in Table 1.

[0146] [Table 1]

[0147] As shown in Table 1, the electrostatic image developing toner sets of Examples 1 to 16 were superior to the electrostatic image developing toner sets of Comparative Examples 1 to 3 in suppressing color unevenness in the resulting images.

[0148] (((1))) A fluorescent toner containing a fluorescent colorant and having a brightness of 75 or more and a non-fluorescent toner containing no fluorescent colorant, wherein the NH4 + The amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is 0.05 mg / L or more and 0.30 mg / L or less. + and the amount of NH4 on the surface of the non-fluorescent toner. + A toner set for developing electrostatic images, the difference between the amount of In addition, the above NH4 + The amount of NH4 detected when the filtrate was analyzed by ion chromatography after weighing 0.5 g of the fluorescent toner or the non-fluorescent toner and adding it to 100 g of ion-exchanged water at 30°C ± 1°C and dispersing it by ultrasonic waves for 30 minutes and then filtering was determined. + The quantity is: (((2))) NH4 on the surface of the fluorescent toner as measured by ion chromatography + and the amount of NH4 on the surface of the non-fluorescent toner. + The toner set for developing electrostatic images according to (((1))), wherein the difference between the amount of (((3))) NH4 on the surface of the non-fluorescent toner + The toner set for developing electrostatic images according to (((1))), wherein the amount of is 0.20 mg / L or more and 1.00 mg / L or less. (((4))) NH4 on the surface of the fluorescent toner +The toner set for developing electrostatic images according to (((1))), wherein the amount of is 0.10 mg / L or more and 0.20 mg / L or less. (((5))) The toner set for developing electrostatic images according to (((1))), wherein the fluorescent toner has a volume average particle size of 5.4 μm or more and 6.2 μm or less. (((6))) The toner set for developing electrostatic images according to (((1))), wherein the fluorescent colorant contains an azomethine fluorescent pigment having a fluorescent peak wavelength in the wavelength region of 500 nm or more and 550 nm or less of the fluorescent spectrum. (((7))) The toner set for developing electrostatic images according to (((1))), wherein the fluorescent toner further contains a non-fluorescent pigment. (((8))) The toner set for developing electrostatic images according to (((7))), wherein the non-fluorescent pigment in the fluorescent toner contains a non-fluorescent pigment having a reflection peak wavelength in the wavelength region of 480 nm or more and 540 nm or less in the reflection spectrum. (((9))) An electrostatic image developer set comprising a first electrostatic image developer containing the fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))), and a second electrostatic image developer containing the non-fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))). (((10))) A toner cartridge set that is detachably attached to an image forming device, comprising: a first toner cartridge that contains the fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))); and a second toner cartridge that contains the non-fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))). (((11))) A process cartridge detachably attached to an image forming apparatus, comprising: a first developing means containing the first electrostatic image developer of the electrostatic image developer set described in (((9))); and a second developing means containing the second electrostatic image developer of the electrostatic image developer set described in (((9))). (((12))) An image forming apparatus comprising: a first image forming means for forming a first image using the fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))); a second image forming means for forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))); a transfer means for transferring the first image and the second image onto a recording medium; and a fixing means for fixing the first image and the second image on the recording medium. (((13))) An image forming method comprising: a first image forming step of forming a first image using the fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))); a second image forming step of forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images described in any one of (((1))) to (((8))); a transfer step of transferring the first image and the second image onto a recording medium; and a fixing step of fixing the first image and the second image on the recording medium.

[0149] According to the inventions (((1))) or (((6))) to (((8))), the amount of NH4 + or the amount of NH4 on the surface of the fluorescent toner is less than 0.05 mg / L or more than 0.30 mg / L as measured by an ion chromatography method. + and the amount of NH4 on the surface of the non-fluorescent toner. + In comparison with a case where the difference from the amount of the toner of the present invention is less than 0.12 mg / L, a toner set for developing electrostatic images is provided which is excellent in suppressing color unevenness in the resulting image. According to the invention (((2))), the amount of NH4 on the surface of the fluorescent toner measured by ion chromatography is + and the amount of NH4 on the surface of the non-fluorescent toner. + In comparison with the case where the difference between the amounts is less than 0.15 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting images. According to the invention related to (((3))), the NH4 + In comparison with when the amount is less than 0.20 mg / L or more than 1.00 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting image. According to the invention related to (((4))), NH4 + In comparison with when the amount is less than 0.10 mg / L or more than 0.20 mg / L, a toner set for developing electrostatic images is provided which is more excellent in suppressing color unevenness in the resulting image. According to the invention related to (((5))), a toner set for developing electrostatic images is provided which is superior in suppressing color unevenness in the resulting images compared to when the volume average particle diameter of the fluorescent toner is less than 5.4 μm or more than 6.2 μm. According to the inventions of (((9)), (((10)), (((11)), (((12))) or (((13)), in the toner set for developing electrostatic images used, the amount of NH4 + or the amount of NH4 on the surface of the fluorescent toner is less than 0.05 mg / L or more than 0.30 mg / L as measured by an ion chromatography method. + and the amount of NH4 on the surface of the non-fluorescent toner. + The present invention provides an electrostatic image developer set, a toner cartridge set, a process cartridge, an image forming apparatus, or an image forming method that are excellent in suppressing color unevenness in the resulting image, compared to when the difference from the amount of the toner cartridge set is less than 0.12 mg / L. [Explanation of symbols]

[0150] 111Y, 111M, 111C, 111K, 111B, 207 Photoconductor 113, 222 Drive roll 112, 224 Support roll 114 Opposing Roll 115Y, 115M, 115C, 115K, 115B cleaning device 116 Intermediate transfer body cleaning device 117Y, 117M, 117C, 117K, 117B, 212 Primary transfer roll 118Y, 118M, 118C, 118K, 118B, 208 charging roll 119Y, 119M, 119C, 119K, 119B, 209 Exposure equipment 120Y, 120M, 120C, 120K, 120B, 211 developing device 133 Intermediate transfer belt 134, 226 Secondary transfer roll 135, 228 Fixing device 140Y, 140M, 140C, 140K, 140B Toner Cartridges 150Y, 150M, 150C, 150K, 150B Image forming unit 200 Process Cartridge 213 Photosensitive drum cleaning device 216 Mounting Rail 217 Cabinet 218 Opening 300, P recording paper

Claims

1. a fluorescent toner containing a fluorescent colorant and having a brightness of 75 or more; a non-fluorescent toner that does not contain a fluorescent colorant, NH on the surface of the fluorescent toner as measured by ion chromatography ４ ＋ The amount of is 0.05 mg / L or more and 0.30 mg / L or less, NH on the surface of the fluorescent toner as measured by ion chromatography ４ ＋ and the amount of NH on the surface of the non-fluorescent toner. ４ ＋ The difference between the amount of Toner set for developing electrostatic images. In addition, the above NH ４ ＋ The amount of NH detected when 0.5 g of the fluorescent toner or the non-fluorescent toner is weighed, put into 100 g of ion-exchanged water at 30° C.±1° C., dispersed by ultrasonic waves for 30 minutes, filtered, and the filtrate is analyzed by ion chromatography is determined. ４ ＋ The quantity is:

2. NH on the surface of the fluorescent toner as measured by ion chromatography ４ ＋ and the amount of NH on the surface of the non-fluorescent toner. ４ ＋ 2. The toner set for developing electrostatic images according to claim 1, wherein the difference between the amount of

3. NH on the surface of the non-fluorescent toner ４ ＋ 2. The toner set for developing electrostatic images according to claim 1, wherein the amount of is 0.20 mg / L or more and 1.00 mg / L or less.

4. NH on the surface of the fluorescent toner ４ ＋ 2. The toner set for developing electrostatic images according to claim 1, wherein the amount of is 0.10 mg / L or more and 0.20 mg / L or less.

5. 2. The toner set for developing electrostatic images according to claim 1, wherein the volume average particle diameter of the fluorescent toner is 5.4 [mu]m or more and 6.2 [mu]m or less.

6. 2. The toner set for developing electrostatic images according to claim 1, wherein the fluorescent colorant comprises an azomethine fluorescent pigment having a fluorescent peak wavelength in the wavelength region of 500 nm or more and 550 nm or less of the fluorescent spectrum.

7. 2. The toner set for developing electrostatic images according to claim 1, wherein said fluorescent toner further contains a non-fluorescent pigment.

8. 8. The toner set for developing electrostatic images according to claim 7, wherein the non-fluorescent pigment in the fluorescent toner contains a non-fluorescent pigment having a reflection peak wavelength in the wavelength region of 480 nm or more and 540 nm or less in the reflection spectrum.

9. a first electrostatic image developer containing the fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; and a second electrostatic image developer containing the non-fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8. Electrostatic image developer set.

10. a first toner cartridge containing the fluorescent toner in the toner set for developing an electrostatic image according to any one of claims 1 to 8; a second toner cartridge containing the non-fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8, Attached to and detached from the image forming device Toner cartridge set.

11. a first developing means containing the first electrostatic image developer of the electrostatic image developer set according to claim 9; a second developing unit containing the second electrostatic image developer of the electrostatic image developer set according to claim 9, Attached to and detached from the image forming device Process cartridge.

12. a first image forming unit for forming a first image using the fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a second image forming unit for forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a transfer means for transferring the first image and the second image onto a recording medium; a fixing unit for fixing the first image and the second image onto the recording medium. Image forming device.

13. a first image forming step of forming a first image using the fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a second image forming step of forming a second image using the non-fluorescent toner of the toner set for developing electrostatic images according to any one of claims 1 to 8; a transfer step of transferring the first image and the second image onto a recording medium; a fixing step of fixing the first image and the second image on the recording medium. Image forming method.

Images