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

Abstract

To provide a green toner for electrostatic charge image development that reduces the generation of color points in an image.SOLUTION: A green toner for electrostatic charge image development includes a green toner particle and silica particles externally attached to the green toner particle. The green toner particle contains a binder resin, an azomethine fluorescent pigment having an emission peak in a wavelength region of 500 nm or more and 550 nm or less in an emission spectrum, and a non-fluorescent pigment having a reflection peak in a wavelength region of 480 nm or more and 540 nm or less in a reflection spectrum. The mass proportion of the azomethine fluorescent pigment in the green toner particle is 3% by mass or more and 20% by mass or less. The silica particles have an average primary particle diameter of 50 nm or more and 350 nm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a green toner for electrostatic charge image development, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

Background Art

[0002] Patent Document 1 discloses a green toner for electrostatic charge image development containing C.I. Solvent Green 5 and a phthalocyanine-based colorant compound X, wherein the content of C.I. Solvent Green 5 in the total amount of the colorant is 5% by mass or more and 50% by mass or less.

[0003] Patent Document 2 discloses a colorant composition containing a copper phthalocyanine pigment, a fluorescent dye, and a resin binder, wherein the hue angle of the coated product on white paper of the composition is 236° or less, and the maximum reflectance of the visible reflection spectrum of the coating film composed of a fluorescent dye that does not contain a copper phthalocyanine pigment and a resin binder is 90 to 130%.

[0004] Patent Document 3 discloses a toner for electrostatic charge image development containing a yellow non-fluorescent dye having a peak wavelength of the absorption spectrum in the wavelength range of 400 to 480 nm and a fluorescent dye having a peak wavelength of the emission spectrum in the wavelength range of 480 to 560 nm, wherein the content of the non-fluorescent dye is 2 to 8 parts by mass with respect to 100 parts by mass of the binder resin, the content of the fluorescent dye is 0.05 to 0.2 parts by mass with respect to 100 parts by mass of the binder resin, and the content ratio represented by the formula (content of non-fluorescent dye / content of fluorescent dye) is in the range of 15 to 150.

[0005] Patent Document 4 discloses that when the contents based on the mass of the coloring pigment and the fluorescent dye are W G , W F respectively, W G ×0.5 > W F > W G ×0.025 is satisfied, and when the absorption peak wavelength of the coloring pigment is P G and the emission peak wavelength of the fluorescent dye is P F respectively, PG <P F A toner satisfying the following is disclosed.

[0006] Patent Document 5 discloses toner particles including toner mother particles containing a fluorescent pigment and a binder, and an external additive fixed to the surface of the toner mother particles. The content of the fluorescent pigment in the toner mother particles is 0.3 wt% or more and 3.0 wt% or less, and the ratio of the number-based particle size distribution to the volume-based particle size distribution of the toner particles is 0.66 or more and 1.00 or less.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0008] The image display unit of an electronic device generally uses a so-called RGB color mode that expresses colors by a combination of three colors: red (R), green (G), and blue (B). On the other hand, electrophotographic image formation generally uses a so-called CMYK color mode that expresses colors by a combination of four colors: cyan (C), magenta (M), yellow (Y), and black (K). When an image expressed in the RGB color mode is reproduced on a recording medium in the CMYK color mode, secondary colors such as green, pink, or orange tend to fade.

[0009] In electrophotographic image formation, green toner, pink toner, or orange toner has been developed for the purpose of enhancing the color reproducibility of green, pink, or orange. As the green toner, a toner containing a yellow fluorescent dye (for example, C.I. Solvent Green 5) and a green pigment or a blue pigment is known. However, since fluorescent dyes generally exhibit concentration quenching in which luminescence decays as the concentration increases, it is difficult to reproduce colors with higher brightness and higher chroma with green toners containing fluorescent dyes.

[0010] For the purpose of reproducing colors with higher brightness and higher chroma, the development of green toners in which fluorescent dyes are replaced with fluorescent pigments is underway. However, since pigments have a higher specific gravity than dyes, replacing fluorescent dyes with fluorescent pigments increases the specific gravity of the green toner. In addition, the green toner is used less frequently compared to each toner of CMYK color and stays in the developing device for a longer time (that is, the time during which the toner is agitated is long). Therefore, green toners are likely to aggregate with each other by agitation in the developing device, and color spots are likely to occur in the image.

[0011] This disclosure has been made under the above circumstances. An object of this disclosure is to provide a green toner for electrostatic charge image development in which color spots are less likely to occur in an image as compared with a green toner for electrostatic charge image development in which the average primary particle diameter of silica particles as an external additive is less than 50 nm.

Means for Solving the Problem

[0012] Means for solving the above problems include the following aspects. <1> containing a binder resin, an azomethine fluorescent pigment having an emission peak in a region where the wavelength of the emission spectrum is 500 nm or more and 550 nm or less, and a non-fluorescent pigment having a reflection peak in a region where the wavelength of the reflection spectrum is 480 nm or more and 540 nm or less, wherein the mass ratio of the azomethine fluorescent pigment in the green toner particles is 3% by mass or more and 20% by mass or less, green toner particles, including silica particles externally added to the green toner particles wherein the average primary particle diameter of the silica particles is 50 nm or more and 350 nm or less A green toner for electrostatic charge image development <2> wherein the mass ratio of the azomethine fluorescent pigment to the total of the content of the azomethine fluorescent pigment and the content of the non-fluorescent pigment is 30% by mass or more and 90% by mass or less The green toner for electrostatic charge image development according to <1> <3> including 0.5 part by mass or more and 5 parts by mass or less of the silica particles with respect to 100 parts by mass of the green toner particles The green toner for electrostatic charge image development according to <1> or <2> <4> when the green toner for electrostatic charge image development is dispersed in water containing a surfactant, the silica particles detached from the green toner particles are 10% by mass or more and 30% by mass or less of the silica particles externally added to the green toner particles The green toner for electrostatic charge image development according to any one of <1> to <3> <5> when the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 40 W, a frequency of 20 kHz, and for 10 minutes, the silica particles that do not detach from the green toner particles are 1% by mass or more and 5% by mass or less of the silica particles externally added to the green toner particles The green toner for electrostatic charge image development according to any one of <1> to <4> <6> wherein the azomethine fluorescent pigment is C.I. Pigment Yellow 101 The green toner for electrostatic charge image development according to any one of <1> to <5> <7> wherein the non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59, and C.I. Pigment Blue 76 The green toner for electrostatic charge image development according to any one of <1> to <6>.

[0013] <8> An electrostatic charge image developer containing the green toner for electrostatic charge image development according to any one of <1> to <7>. <9> A toner cartridge that houses the green toner for electrostatic charge image development according to any one of <1> to <7> and is detachable from an image forming apparatus. <10> Developing means for housing the electrostatic charge image developer according to <8> and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer. A process cartridge that is detachable from an image forming apparatus. <11> An image carrier, Charging means for charging the surface of the image carrier, Electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the image carrier, Developing means for housing the electrostatic charge image developer according to <8> and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, Transferring means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus comprising: <12> A charging step of charging the surface of the image carrier, An electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, A developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to <8>, A transferring step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, A fixing step of fixing the toner image transferred to the surface of the recording medium, An image forming method comprising: <13> An electrophotographic image forming apparatus including first to sixth image forming units that form images of respective colors of pink, yellow, magenta, cyan, black, and green. An image forming unit that forms the green image contains the electrostatic charge image developer described in <8>. An image forming apparatus. <14> An electrophotographic image forming method including first to sixth image forming steps that form images of respective colors of pink, yellow, magenta, cyan, black, and green. An image forming step that forms the green image uses the electrostatic charge image developer described in <8>. An image forming method.

[0014] According to <1>, <2>, <6>, or <7>, there is provided a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the average primary particle diameter of silica particles as an external additive is less than 50 nm. According to <3>, there is provided a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the external addition amount of silica particles is less than 0.5 parts by mass. According to <4>, there is provided a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the silica particles detached from the green toner particles are less than 10% by mass. According to <5>, there is provided a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the silica particles that do not detach from the green toner particles are more than 5% by mass.

[0015] According to <8>, there is provided an electrostatic charge image developer in which color spots are less likely to occur in an image, as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. According to <9>, there is provided a toner cartridge in which color spots are less likely to occur in an image, as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. According to <10>, a process cartridge in which color dots are less likely to occur in an image is provided as compared with the case where the average primary particle diameter of silica particles, which are an external additive of a green toner for electrostatic charge image development, is less than 50 nm. According to <11> or <13>, an image forming apparatus in which color dots are less likely to occur in an image is provided as compared with the case where the average primary particle diameter of silica particles, which are an external additive of a green toner for electrostatic charge image development, is less than 50 nm. According to <12> or <14>, an image forming method in which color dots are less likely to occur in an image is provided as compared with the case where the average primary particle diameter of silica particles, which are an external additive of a green toner for electrostatic charge image development, is less than 50 nm.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments.

[0018] In the present disclosure, “A and / or B” is synonymous with “at least one of A and B”. That is, “A and / or B” means that it may be only A, only B, or a combination of A and B.

[0019] In the present disclosure, the numerical range indicated by using “~” indicates a range including the numerical values described before and after “~” as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0020] In the present disclosure, the term "step" includes not only an independent step but also the step even when it cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0021] When an embodiment in the present disclosure is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Further, the size of the members in each drawing is conceptual, and the relative relationship of the sizes between the members is not limited thereto.

[0022] In the present disclosure, each component may contain a plurality of corresponding substances. When referring to the amount of each component in the composition, when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition. In the present disclosure, the particles corresponding to each component may contain a plurality of types. When there are a plurality of types of particles corresponding to each component in the composition, unless otherwise specified, the particle diameter of each component means a value for the mixture of the plurality of types of particles present in the composition.

[0023] When the compound is represented by a structural formula in the present disclosure, it may be represented by a structural formula in which the symbols (C and H) representing carbon atoms and hydrogen atoms in the hydrocarbon group and / or hydrocarbon chain are omitted.

[0024] In the present disclosure, "(meth)acryl" is an expression including both acrylic and methacrylic, and "(meth)acrylate" is an expression including both acrylate and methacrylate.

[0025] In the present disclosure, the "toner for electrostatic charge image development" is also referred to as "toner", the "green toner for electrostatic charge image development" is also referred to as "green toner", the "electrostatic charge image developer" is also referred to as "developer", and the "carrier for electrostatic charge image development" is also referred to as "carrier".

[0026] In the present disclosure, Colour Index (color index) is abbreviated as "C.I.".

[0027] <Green toner for electrostatic charge image development> In the present disclosure, the green toner means a toner in which the hue angle h of a solid image (image with a density of 100%) formed on coated paper is 128.5° or more and 144.5° or less. The hue angle h is calculated by the following formula from the a * a * b * value and b * value in the CIE1976L * color system. Hue angle h = tan -1 (b * / a * ) In the present disclosure, the hue angle h of the solid image (image with a density of 100%) formed by the green toner on coated paper is preferably 131° or more and 143° or less, and more preferably 135° or more and 140° or less.

[0028] In the present disclosure, the solid image (image with a density of 100%) formed by the green toner on coated paper has a lightness L * a * b * in the CIE1976L * color system of 70 or more and a chroma C * of 85 or more is preferable. The chroma C * is a value calculated by the following formula from the a * a * b * value and b * value in the CIE1976L * color system. Chroma C * ={(a * ) 2 +(b *) 2 [[ID=2}} 0.5

[0029] In the present disclosure, a fluorescent pigment refers to a pigment that emits light by external light energy, and a non-fluorescent pigment refers to a pigment that does not emit light by external light energy. Generally, a fluorescent pigment exhibits color by reflected light and emitted light, and a non-fluorescent pigment exhibits color only by reflected light.

[0030] The green toner according to the present embodiment contains green toner particles. The green toner particles include a binder resin, an azomethine fluorescent pigment having an emission peak in the region of 500 nm or more and 550 nm or less in the emission spectrum wavelength, and a non-fluorescent pigment having a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum wavelength. That is, the green toner particles in the present embodiment are toner particles containing a yellow fluorescent pigment and a green pigment or a blue pigment.

[0031] Hereinafter, the "azomethine fluorescent pigment having an emission peak in the region of 500 nm or more and 550 nm or less in the emission spectrum wavelength" is referred to as "azomethine fluorescent pigment (Y)", and the "non-fluorescent pigment having a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum wavelength" is referred to as "pigment (G)".

[0032] In the green toner particles in the present embodiment, the mass ratio of the azomethine fluorescent pigment (Y) in the green toner particles is 3% by mass or more and 20% by mass or less. When the mass ratio of the azomethine fluorescent pigment (Y) is less than 3% by mass or more than 20% by mass, it may be difficult for the image to exhibit the desired green color, or density unevenness may occur in the image. From the viewpoints of the image exhibiting the desired green color and excellent uniformity of image density, the mass ratio of the azomethine fluorescent pigment (Y) is 3% by mass or more and 20% by mass or less, preferably 3% by mass or more and 15% by mass or less, and more preferably 3% by mass or more and 10% by mass or less.

[0033] In the green toner particles of the present embodiment, from the viewpoints of the image exhibiting the desired green color and excellent uniformity of image density, the mass ratio of the azomethine fluorescent pigment (Y) in the total of the content of the azomethine fluorescent pigment (Y) and the content of the pigment (G) is preferably 30% by mass or more and 90% by mass or less, more preferably 35% by mass or more and 80% by mass or less, and still more preferably 40% by mass or more and 70% by mass or less.

[0034] In the green toner particles of the present embodiment, the total content of the azomethine fluorescent pigment (Y) and the pigment (G) with respect to the entire green toner particles is preferably 4% by mass or more and 25% by mass or less. When the total content of the two pigments is 4% by mass or more, the chroma of the green image is high. From the viewpoint of increasing the chroma of the green image, the total content of the two pigments is preferably 4% by mass or more, more preferably 5% by mass or more, and still more preferably 6% by mass or more. When the total content of the two pigments is 25% by mass or less, the lightness of the green image is high. From the viewpoint of increasing the lightness of the green image, the total content of the two pigments is preferably 25% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less.

[0035] The wavelength difference between the emission peak of the azomethine fluorescent pigment (Y) having the largest content among the azomethine fluorescent pigments (Y) contained in the green toner particles in the present embodiment and the reflection peak of the pigment (G) having the largest content among the pigments (G) contained in the green toner particles is preferably 40 nm or less from the viewpoints of increasing the lightness and chroma of the green image. The smaller the wavelength difference between the above emission peak and reflection peak, the more preferable, more preferably 30 nm or less, still more preferably 20 nm or less, still more preferably 10 nm or less, still more preferably 5 nm or less, and ideally 0 nm.

[0036] In all combinations of the emission peak of the azomethine fluorescent pigment (Y) and the reflection peak of the pigment (G) contained in the green toner particles in this embodiment, the wavelength difference between the emission peak and the reflection peak is preferably 40 nm or less from the viewpoint of increasing the brightness and saturation of the green image. The smaller the wavelength difference between the emission peak and the reflection peak, the more preferable, and it is more preferably 30 nm or less, more preferably 20 nm or less, even more preferably 10 nm or less, even more preferably 5 nm or less, and ideally 0 nm.

[0037] The green toner according to this embodiment has a CIE1976L standard with a color sample TOKA FLASH VIVA DX 650 (T&K TOKA Corporation) when forming a solid image (image with 100% density) on coated paper. * a * b * The color difference ΔE in the color system is preferably 13.5 or less. The smaller the color difference ΔE, the better, with 10 or less being more preferable, 6.5 or less being even more preferable, 3 or less being even more preferable, 1 or less being even more preferable, and 0 being ideal.

[0038] In this embodiment, the CIE1976L * a * b * The color difference ΔE from the color sample TOKA FLASH VIVA DX 650 (T&K TOKA Corporation) in the color system is defined by the following formula.

[0039]

number

[0040] In the above formula, L 1 , a 1 , b 1 and L 2 , a 2 , b 2 is CIE1976L * a * b * L in color space * Value, a * Value, b* is the value of L 1 , a 1 , b 1 are the L value, a value, and b value of the color sample TOKA FLASH VIVA DX 650, which are the values obtained by measuring the color sample TOKA FLASH VIVA DX 650 with a reflection spectrophotometer. * value, a * value, b * value, which are the values obtained by measuring the color sample TOKA FLASH VIVA DX 650 with a reflection spectrophotometer. 2 , a 2 , b 2 are the L value, a value, and b value of the image formed by the green toner, which are the values obtained by measuring the image with a reflection spectrophotometer. The color sample TOKA FLASH VIVA DX 650 (T&K TOKA Co., Ltd.) is a color sample with an image formed on coated paper, and the image formed by the green toner is also formed on coated paper, and the color difference ΔE is measured. * value, a * value, b * value, which are the values obtained by measuring the image with a reflection spectrophotometer. The color sample TOKA FLASH VIVA DX 650 (T&K TOKA Co., Ltd.) is a color sample with an image formed on coated paper, and the image formed by the green toner is also formed on coated paper, and the color difference ΔE is measured.

[0041] In this embodiment, the CIE1976L * a * b * coordinate values of the color system are measured by the following method. After mixing the green toner to be a sample with a carrier, put it into the developing device of the image forming apparatus, and form a solid image (image with a density of 100%) with a toner loading amount of 4.0 g / m 2 on the coated paper at a fixing temperature of 180°C. For the formed solid image, measure the CIE1976L * a * b * coordinate values of the color system at 10 random locations using a reflection spectrophotometer, and calculate the average values of the L * value, a * value, and b * value.

[0042] Preferably, for the green toner according to this embodiment, the reflectance of the reflection peak in the spectral reflectance spectrum of the solid image formed on the coated paper is 70% or more.

[0043] The green toner according to this embodiment contains silica particles externally added to the green toner particles, and the average primary particle size of the silica particles is 50 nm or more and 350 nm or less. The silica particles with an average primary particle size of 50 nm or more and 350 nm or less act as a spacer on the surface of the green toner particles, suppressing the aggregation of the green toner particles, and as a result, suppressing the occurrence of color spots in the image. When the average primary particle size of the silica particles is less than 50 nm, they are likely to be buried in the green toner particles, and the action as a spacer is weak. From the viewpoint of being difficult to be buried in the green toner particles, the average primary particle size of the silica particles is 50 nm or more, preferably 70 nm or more, more preferably 90 nm or more, and still more preferably 100 nm or more. When the average primary particle size of the silica particles exceeds 350 nm, the charge of the green toner may be reduced, and density unevenness may occur in the image. From the viewpoint of excellent chargeability of the green toner and uniformity of image density, the average primary particle size of the silica particles is 350 nm or less, preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 150 nm or less.

[0044] In the green toner according to this embodiment, {average primary particle size of silica particles / volume average particle size of green toner particles×100} is preferably 0.5 or more and 7 or less, more preferably 0.8 or more and 5 or less, and still more preferably 1 or more and 3 or less.

[0045] Hereinafter, the configuration of the green toner according to this embodiment will be described in detail.

[0046] [Green toner particles] The green toner particles contain a binder resin, an azomethine fluorescent pigment (Y), and a pigment (G), and are configured to contain a release agent and other additives as necessary.

[0047] -Azomethine fluorescent pigment (Y)- The azomethine fluorescent pigment (Y) has an emission peak in the wavelength range of 500 nm or more and 550 nm or less in the emission spectrum. The emission peak of the azomethine fluorescent pigment (Y) is preferably in the wavelength range of 505 nm or more and 540 nm or less, more preferably in the wavelength range of 510 nm or more and 535 nm or less, and even more preferably in the wavelength range of 515 nm or more and 530 nm or less.

[0048] The azomethine fluorescent pigment (Y) is a pigment having an azomethine structure (that is, -R 1 C=N-, R 1 is a hydrogen atom or a monovalent substituent) in the molecule. As the azomethine fluorescent pigment (Y), it is preferably a bisazomethine, that is, -R 1 C=N-N=CR 2 -(R 1 and R 2 are each independently a hydrogen atom or a monovalent substituent) in the molecule.

[0049] Examples of the azomethine fluorescent pigment (Y) include the following azomethine compounds (1) to (3).

[0050]

Chemical formula

[0051] The emission peak of the azomethine compound (1) is 520 nm. The emission peak of the azomethine compound (2) is 510 nm. The emission peak of the azomethine compound (3) is 520 nm.

[0052] The azomethine fluorescent pigment (Y) is preferably at least one selected from the group consisting of the azomethine compound (1), the azomethine compound (2), and the azomethine compound (3).

[0053] As the azomethine fluorescent pigment (Y), C.I. Pigment Yellow 101 is preferred. C.I. Pigment Yellow 101 is the azomethine compound (1).

[0054] The volume average particle diameter D1 of the azomethine fluorescent pigment (Y) is preferably 50 nm or more and 800 nm or less, more preferably 150 nm or more and 600 nm or less, and still more preferably 250 nm or more and 400 nm or less, from the viewpoint of achieving a good balance among the dispersibility in toner particles, color developability on a recording medium, fixability to the recording medium, and the like. The volume average particle diameter of the pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction / scattering particle size distribution analyzer (for example, LA-700 manufactured by Horiba, Ltd.). Draw the particle size distribution based on volume from the small particle size side, and the particle diameter at which the cumulative value becomes 50% is defined as the volume average particle diameter.

[0055] - Pigment (G)- The pigment (G) has a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum. The reflection peak of the pigment (G) is preferably in the region of 485 nm or more and 535 nm or less, more preferably in the region of 490 nm or more and 530 nm or less, and still more preferably in the region of 495 nm or more and 525 nm or less.

[0056] Examples of the pigment (G) include halogenated phthalocyanine compounds and lake pigments of triphenylmethane dyes. As the pigment (G), halogenated phthalocyanine compounds are preferred.

[0057] As the pigment (G), halogenated phthalocyanine compounds are preferred, and at least one selected from the group consisting of copper halogenated phthalocyanine and zinc halogenated phthalocyanine is preferred. Examples of the copper halogenated phthalocyanine include C.I. Pigment Green 7 (reflection peak 500 nm), C.I. Pigment Green 36 (reflection peak 510 nm), and C.I. Pigment Blue 76 (reflection peak 490 nm). Examples of the zinc halogenated phthalocyanine include C.I. Pigment Green 58 (reflection peak 515 nm) and C.I. Pigment Green 59 (reflection peak 520 nm).

[0058] The pigment (G) is preferably at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59, and C.I. Pigment Blue 76.

[0059] From the viewpoint of achieving a good balance among the dispersibility in toner particles, the color rendering property on the recording medium, the fixability to the recording medium, etc., the volume average particle diameter D2 of the pigment (G) is preferably 50 nm or more and 300 nm or less, more preferably 100 nm or more and 250 nm or less, and still more preferably 120 nm or more and 200 nm or less. The volume average particle diameter of the pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction / scattering particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.). Draw the particle size distribution on a volume basis from the small particle size side, and the particle diameter at which the cumulative percentage is 50% is defined as the volume average particle diameter.

[0060] From the viewpoint of enhancing the lightness and chroma of the green image, the ratio D1 / D2 of the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) to the volume average particle diameter D2 of the pigment (G) is preferably 1 or more and 3 or less, more preferably 1.2 or more and 2.5 or less, and still more preferably 1.5 or more and 2 or less.

[0061] The green toner particles may contain other colorants other than the azomethine fluorescent pigment (Y) and the pigment (G). The total amount of the azomethine fluorescent pigment (Y) and the pigment (G) in the total colorants contained in the green toner particles is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 100% by mass.

[0062] -Binder resin- Examples of the binding resin include vinyl resins composed of homopolymers of monomers such as styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), or copolymers obtained by combining two or more of these monomers. Examples of the binding resin also include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, modified rosin, mixtures of these with the vinyl resins, or graft polymers obtained by polymerizing vinyl monomers in the presence of these. These binding resins may be used alone or in combination of two or more.

[0063] As the binding resin, a polyester resin is preferred. Examples of the polyester resin include known polyester resins.

[0064] Examples of the polyester resin include condensation polymers of polyvalent carboxylic acids and polyhydric alcohols. As the polyester resin, commercially available products may be used, or those synthesized may be used.

[0065] Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., having 1 to 5 carbon atoms) alkyl esters thereof. Among these, as the polyvalent carboxylic acid, for example, aromatic dicarboxylic acids are preferred. As the polyvalent carboxylic acid, a carboxylic acid having a trivalent or higher valency that forms a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the carboxylic acid having a trivalent or higher valency include trimellitic acid, pyromellitic acid, anhydrides thereof, or lower (e.g., having 1 to 5 carbon atoms) alkyl esters thereof. The polyvalent carboxylic acid may be used alone or in combination of two or more.

[0066] Examples of the polyhydric alcohol 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.), aromatic diols (e.g., ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferred, and more preferably aromatic diols. As the polyhydric alcohol, a polyhydric alcohol having a trivalent or higher valency that forms a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the polyhydric alcohol having a trivalent or higher valency include glycerin, trimethylolpropane, pentaerythritol. The polyhydric alcohol may be used alone or in combination of two or more.

[0067] The glass transition temperature (Tg) of the polyester resin is preferably 50°C or higher and 80°C or lower, more preferably 50°C or higher and 65°C or lower. The glass transition temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC). More specifically, it is determined by the "extrapolated glass transition start temperature" described in the method for determining the glass transition temperature in JIS K7121-1987 "Method for Measuring the Transition Temperature of Plastics".

[0068] The weight average molecular weight (Mw) of the polyester resin is preferably 5000 or higher and 1000000 or lower, more preferably 7000 or higher and 500000 or lower. The number average molecular weight (Mn) of the polyester resin is preferably 2000 or higher and 100000 or lower. The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or higher and 100 or lower, more preferably 2 or higher and 60 or lower. The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out using Tosoh's GPC·HLC-8120GPC as the measuring device, Tosoh's column·TSKgel SuperHM-M (15 cm), and THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

[0069] The polyester resin is obtained by a known production method. Specifically, for example, it is obtained by a method in which the polymerization temperature is 180°C or higher and 230°C or lower, the inside of the reaction system is depressurized as necessary, and the reaction is carried out while removing water or alcohol generated during condensation. When the monomer of the raw material is insoluble or incompatible at the reaction temperature, a high-boiling solvent may be added as a dissolution aid to dissolve it. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. When there are monomers with poor compatibility, it is advisable to first condense the monomers with poor compatibility with the acid or alcohol to be polycondensed with the monomers, and then carry out the polycondensation with the main components.

[0070] The content of the binder resin is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and still more preferably 60% by mass or more and 85% by mass or less, based on the total toner particles.

[0071] -Release agent- Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters; and the like. The release agent is not limited thereto.

[0072] The melting temperature of the release agent is preferably 50°C or more and 110°C or less, and more preferably 60°C or more and 100°C or less. The melting temperature is determined by the "melting peak temperature" described in the method for determining the melting temperature of JIS K7121-1987 "Method for Measuring the Transition Temperature of Plastics" from the DSC curve obtained by differential scanning calorimetry (DSC).

[0073] The content of the release agent is 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 toner particles.

[0074] -Other additives- Examples of other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are included in the toner particles as internal additives.

[0075] -Properties of toner particles, etc.- The toner particles may be single-layer structured toner particles or so-called core-shell structured toner particles composed of a core part (core particles) and a coating layer (shell layer) covering the core part. The core-shell structured toner particles may be composed of, for example, a core part containing a binder resin and other additives such as a colorant and a release agent as required, and a coating layer containing a binder resin.

[0076] The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less.

[0077] The various average particle diameters and various particle size distribution indices of the toner particles are measured using a Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte used is ISOTON-II (manufactured by Beckman Coulter). At the time of measurement, as a dispersant, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% by mass aqueous solution of a surfactant (sodium alkylbenzene sulfonate is preferred). This is added to 100 ml or more and 150 ml or less of the electrolyte. The electrolyte in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for 1 minute, and the particle size distribution of particles having a particle diameter in the range of 2 μm or more and 60 μm or less is measured using an aperture with an aperture diameter of 100 μm by a Coulter Multisizer II. The number of particles to be sampled is 50,000. For the particle size ranges (channels) divided based on the measured particle size distribution, cumulative distributions of volume and number are drawn from the smaller diameter side, respectively, and the particle diameter at which the cumulative value becomes 16% is defined as the volume particle diameter D16v, the number particle diameter D16p, the particle diameter at which the cumulative value becomes 50% is defined as the volume average particle diameter D50v, the cumulative number average particle diameter D50p, and the particle diameter at which the cumulative value becomes 84% is defined as the volume particle diameter D84v and the number particle diameter D84p. Using these, the volume particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 and the number particle size distribution index (GSDp) is (D84p / D16p) 1 / 2 and is calculated as such.

[0078] The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, more preferably 0.95 or more and 0.98 or less.

[0079] The average circularity of the toner particles is obtained by (circumference equivalent to a circle) / (circumference) [(circumference of a circle having the same projected area as the particle image) / (circumference of the particle projection image)]. Specifically, it is a value measured by the following method. First, toner particles to be measured are aspirated and collected, a flat flow is formed, and stroboscopic light emission is instantaneously performed to capture a particle image as a still image, which is obtained by a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation) that analyzes the particle image. The number of samplings when obtaining the average circularity is set to 3500. When the toner has an external additive, after dispersing the toner (developer) to be measured in water containing a surfactant, ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed.

[0080] [Silica particles] The green toner according to this embodiment contains silica particles as an external additive. Examples of the silica particles include fumed silica particles, sol-gel silica particles, and mixtures thereof.

[0081] The method for manufacturing fumed silica particles is known. The sol-gel method for manufacturing sol-gel silica particles is known. The sol-gel method includes, for example, dropping aqueous ammonia into a mixed solution of tetraalkoxysilane, water, and alcohol to prepare a silica sol suspension, centrifuging wet silica gel from the silica sol suspension, and drying the wet silica gel to obtain silica particles. Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and the like.

[0082] The surface of the silica particles is preferably subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing the silica particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples include silane-based coupling agents, silicone oils, titanate-based coupling agents, and aluminum-based coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobizing agent is, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the silica particles.

[0083] The average primary particle diameter of the silica particles is 50 nm or more and 350 nm or less from the viewpoints of the spacer effect and toner chargeability, preferably 70 nm or more and 300 nm or less, more preferably 90 nm or more and 200 nm or less, and still more preferably 100 nm or more and 150 nm or less. The average primary particle diameter of the silica particles can be controlled, for example, by the amount of material used and the dropping time in the sol-gel method.

[0084] The average circularity of the silica particles is preferably 0.70 or more and 1.00 or less, more preferably 0.80 or more and 1.00 or less, and still more preferably 0.90 or more and 1.00 or less from the viewpoint of easy rolling on the green toner particles.

[0085] The method for obtaining the average primary particle diameter and average circularity of the silica particles is as follows. The green toner is photographed at a magnification of 40,000 times using a scanning electron microscope (SEM) (Hitachi High-Technologies Corporation, S-4800) equipped with an energy dispersive X-ray analyzer (EDX analyzer) (Horiba, Ltd., EMAX Evolution X-Max80mm 2 ). Based on the presence of silicon atoms and oxygen atoms by EDX analysis, 500 primary particles of silica particles are specified from within one field of view. The images of 500 silica particles are analyzed with image processing and analysis software WinRoof (Miyaya Shoko Co., Ltd.) to obtain the equivalent circle diameter, area, and perimeter of each primary particle. The equivalent circle diameter at which the cumulative value reaches 50% from the smaller diameter side in the number-based distribution of the equivalent circle diameter is defined as the average primary particle diameter. The circularity is defined as circularity = 4π × (area of the particle image) ÷ (perimeter of the particle image) 2 . The circularity at which the cumulative value reaches 50% from the smaller side in the number-based distribution of the circularity is defined as the average circularity.

[0086] When the green toner according to this embodiment is dispersed in water containing a surfactant, the silica particles desorbed from the green toner particles are preferably 10% by mass or more and 30% by mass or less of the silica particles externally added to the green toner particles. This mass ratio of the silica particles is also referred to as the weak adhesion ratio of the silica particles.

[0087] When the weak adhesion ratio of the silica particles is 10% by mass or more, the silica particles are likely to roll on the green toner particles, and it is easy to suppress the generation of color spots. From this perspective, the weak adhesion ratio of the silica particles is more preferably 12% by mass or more, and even more preferably 15% by mass or more. When the weak adhesion ratio of the silica particles is 30% by mass or less, the uniformity of the image density is excellent. From this perspective, the weak adhesion ratio of the silica particles is more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0088] The method for obtaining the weak adhesion ratio of the silica particles is as follows. (1) Only 3 g of the green toner particles constituting the green toner are formed into a pellet having a diameter of 30 mm and a thickness of 2 mm under the conditions of a load of 10 t and a pressing time of 60 seconds using an automatic pressure molding machine (BRE-32, manufactured by Maekawa Testing Machine Co., Ltd.). This is designated as sample (0). (2) 3 g of the green toner is formed into a pellet in the same manner as in (1). This is designated as sample (b). (3) Prepare an aqueous surfactant solution containing 0.5% by mass of the surfactant Neugen ET-165 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in ion-exchanged water. Put 50 mL of the aqueous surfactant solution into a 100 mL glass beaker, add 4 g of the green toner thereto, and stir with a magnetic stirrer at a rotation speed of 100 rpm for 5 minutes to prepare a toner dispersion. The toner dispersion is centrifuged (rotation radius 10 cm, rotation speed 3000 rpm, 2 minutes), and the supernatant (containing silica particles weakly adhered to the toner particles) is removed. Add 50 mL of ion-exchanged water to the sediment to prepare a dispersion, and suction filter the dispersion using a suction filter and filter paper (Tongshan funnel filter paper No. 5C 60φm / m, manufactured by Tongshan Co., Ltd.), and collect the solid content remaining on the filter paper. Again, add 50 mL of ion-exchanged water to the solid content to prepare a dispersion, suction filter, and collect the solid content remaining on the filter paper. The solid content is left standing in a constant temperature bath at 40°C for 12 hours to dry. 3 g of the dried product is formed into a pellet in the same manner as in (1). This is designated as sample (a). (4) Using a fluorescent X-ray device (ZSX-100e, manufactured by Rigaku Corporation), quantitative analysis of silicon is performed on each of the sample (0), sample (b), and sample (a). A calibration curve for silicon is prepared in advance, and the amount of silicon is calculated using the calibration curve. Let the amount of silicon in sample (0) be C0, the amount of silicon in sample (b) be Cb, and the amount of silicon in sample (a) be Ca. The strong adhesion ratio of silica particles is calculated from the following formula. Weak adhesion ratio of silica particles (mass%) = (Cb - Ca) / (Cb - C0) × 100

[0089] The green toner according to this embodiment is obtained by dispersing the green toner in water containing a surfactant and subjecting it to ultrasonic treatment at an output of 40 W, a frequency of 20 kHz, and for 10 minutes. It is preferable that the silica particles that do not detach from the green toner particles are 1 mass% or more and 5 mass% or less of the silica particles externally added to the green toner particles. This mass ratio of the silica particles is also referred to as the strong adhesion ratio of the silica particles.

[0090] When the strong adhesion ratio of the silica particles is 1 mass% or more, the uniformity of the image density is excellent. From this perspective, the strong adhesion ratio of the silica particles is more preferably 2 mass% or more, and even more preferably 3 mass% or more. When the strong adhesion ratio of the silica particles is 5 mass% or less, the silica particles are likely to roll on the green toner particles, and it is easy to suppress the generation of color spots. From this perspective, the strong adhesion ratio of the silica particles is more preferably 4 mass% or less.

[0091] The method for obtaining the strong adhesion ratio of the silica particles is as follows. (1) Only 3 g of the green toner particles constituting the green toner are molded into a pellet having a diameter of 30 mm and a thickness of 2 mm under the conditions of a load of 10 t and a pressure application time of 60 seconds using an automatic pressure molding machine (BRE-32, manufactured by Maekawa Testing Machine Co., Ltd.). This is used as sample (0). (2) 3 g of the green toner is molded into a pellet in the same manner as in (1). This is used as sample (b). (3) Prepare an aqueous surfactant solution containing 0.5% by mass of surfactant Neugen ET-165 (Daiichi Kogyo Seiyaku Co., Ltd.) in ion-exchanged water. Put 50 mL of the aqueous surfactant solution into a 100 mL glass beaker, add 4 g of green toner thereto, and stir with a magnetic stirrer at a rotation speed of 100 rpm for 5 minutes to prepare a toner dispersion. Insert the probe of an ultrasonic homogenizer VCX750 (Sonic and Material) into the toner dispersion (insert it until the distance between the tip of the probe and the bottom surface of the beaker is 1.0 cm), and apply ultrasonic waves (output 40 W, frequency 20 kHz) for 10 minutes. Centrifuge the toner dispersion (rotation radius 10 cm, rotation speed 3000 rpm, 2 minutes), and remove the supernatant. Add 50 mL of ion-exchanged water to the sediment (containing silica particles strongly adhering to the toner particles) to prepare a dispersion, and subject the dispersion to suction filtration using a suction filter and filter paper (Tongshan funnel filter paper No. 5C 60φm / m, Tongshan Seisakusho), and collect the solid content remaining on the filter paper. Again, add 50 mL of ion-exchanged water to the solid content to prepare a dispersion, perform suction filtration, and collect the solid content remaining on the filter paper. Leave the solid content in a constant temperature bath at 40°C for 12 hours to dry it. Mold 3 g of the dried product into pellets in the same manner as in (1). This is designated as sample (a). (4) Using a fluorescent X-ray apparatus (ZSX-100e, Rigaku Corporation), perform quantitative analysis of silicon for each of sample (0), sample (b), and sample (a). Prepare a calibration curve for silicon in advance, and calculate the amount of silicon from the calibration curve. Let the amount of silicon in sample (0) be C0, the amount of silicon in sample (b) be Cb, and the amount of silicon in sample (a) be Ca, and calculate the strong adhesion ratio of silica particles from the following formula. Strong adhesion ratio of silica particles (mass%) = (Ca - C0) / (Cb - C0) × 100

[0092] The weak adhesion ratio and strong adhesion ratio of silica particles can be controlled by adjusting the rotation speed and / or rotation time of a blender or mixer when mixing green toner particles and silica particles.

[0093] From the perspective that color spots are less likely to occur in the image, the externally added amount of silica particles is preferably 0.5 parts by mass or more and 5 parts by mass or less, more preferably 0.8 parts by mass or more and 4 parts by mass or less, and still more preferably 1 part by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the green toner particles.

[0094] The content of silica particles is preferably 50% by mass or more and 100% by mass or less with respect to the total amount of externally added agents contained in the green toner.

[0095] [Other externally added agents] The green toner according to this embodiment may contain externally added agents other than silica particles. As externally added agents other than silica particles, SrTiO 3 , TiO 2 , Al 2 O 3 , CuO, ZnO, SnO 2 , CeO 2 , Fe 2 O 3 , MgO, BaO, CaO, K 2 O, Na 2 O, ZrO 2 , CaO·SiO 2 , K 2 O·(TiO 2 ) n , Al 2 O 3 ·2SiO 2 , CaCO 3 , MgCO 3 , BaSO 4 , MgSO 4 and other inorganic particles can be mentioned.

[0096] The surface of the above inorganic particles is preferably subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane-based coupling agents, silicone oils, titanate-based coupling agents, and aluminum-based coupling agents. These may be used alone or in combination of two or more.

[0097] Examples of the external additive include resin particles (such as resin particles of polystyrene, polymethyl methacrylate, melamine resin, etc.), cleaning agents (such as metal salts of higher fatty acids represented by zinc stearate, particles of fluorine-based high molecular weight substances), and the like.

[0098] When the green toner according to this embodiment contains other external additives in addition to silica particles, the addition amount of the other external additives is preferably 0.01 part by mass or more and 5 parts by mass or less, and more preferably 0.01 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the toner particles.

[0099] [Method for manufacturing green toner] The green toner according to this embodiment can be obtained by externally adding an external additive to the green toner particles after manufacturing the green toner particles. The external additive contains at least silica particles.

[0100] The green toner particles may be manufactured by either a dry method (such as a kneading and grinding method, etc.) or a wet method (such as an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method, etc.). There are no particular restrictions on these manufacturing methods, and known manufacturing methods are adopted. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

[0101] When the green toner particles are manufactured by the aggregation and coalescence method, the following manufacturing method is preferable. A step of preparing a resin particle dispersion liquid in which resin particles serving as a binder resin are dispersed (resin particle dispersion liquid preparation step); A step of preparing a fluorescent pigment (Y) dispersion liquid in which an azomethine fluorescent pigment (Y) is dispersed (fluorescent pigment (Y) dispersion liquid preparation step); A step of preparing a pigment (G) dispersion liquid in which a pigment (G) is dispersed (pigment (G) dispersion liquid preparation step); A step of aggregating the mixed particles in a mixed dispersion liquid obtained by mixing the resin particle dispersion liquid, the fluorescent pigment (Y) dispersion liquid, and the pigment (G) dispersion liquid to form aggregated particles (aggregated particle formation step); A step of heating the aggregated particle dispersion liquid in which the aggregated particles are dispersed to fuse and coalesce the aggregated particles to form green toner particles (fusion and coalescence step); The manufacturing method has these steps.

[0102] The details of each step will be described below. In the following description, the green toner particles are simply referred to as toner particles. In the following description, a method for obtaining toner particles containing a release agent will be described, but the release agent is used as needed.

[0103] - Resin Particle Dispersion Preparation Step - The resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium with a surfactant.

[0104] Examples of the dispersion medium used for the resin particle dispersion include aqueous media. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0105] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, particularly, anionic surfactants and cationic surfactants are mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0106] In a resin particle dispersion, as a method for dispersing resin particles in a dispersion medium, for example, general dispersion methods such as a rotary shear type homogenizer, a ball mill having media, a sand mill, a dyno mill, etc. can be mentioned. Further, depending on the type of resin particles, the resin particles may be dispersed in the dispersion medium by an inverse phase emulsification method. The inverse phase emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase) for neutralization, and then an aqueous medium (W phase) is introduced to perform an inversion from W / O to O / W, and the resin is dispersed in the aqueous medium in a particulate form.

[0107] As the volume average particle diameter of the resin particles dispersed in the resin particle dispersion, for example, 0.01 μm or more and 1 μm or less is preferable, 0.08 μm or more and 0.8 μm or less is more preferable, and 0.1 μm or more and 0.6 μm or less is still more preferable. The volume average particle diameter of the resin particles is measured using the particle size distribution obtained by measurement with a laser diffraction type particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.). For the divided particle size range (channel), the cumulative distribution is drawn from the small particle size side with respect to the volume, and the particle diameter at which the cumulative percentage becomes 50% with respect to all particles is measured as the volume average particle diameter D50v. Note that the volume average particle diameter of the particles in other dispersions is also measured in the same manner.

[0108] The content of the 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.

[0109] The method for preparing the release agent particle dispersion is the same as that of the resin particle dispersion. The content of the release agent particles contained in the release agent particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0110] - Fluorescent pigment (Y) dispersion preparation step - The fluorescent pigment (Y) dispersion is prepared, for example, by dispersing an azomethine fluorescent pigment (Y) in a dispersion medium with a surfactant.

[0111] Examples of the dispersion medium used for the fluorescent pigment (Y) dispersion include an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0112] Examples of the surfactant 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 mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0113] Examples of the method for dispersing the azomethine fluorescent pigment (Y) in the dispersion medium include dispersion methods using a rotary shear homogenizer, a ball mill having media, a sand mill, a dyno mill, a kimi mill, and the like.

[0114] The volume average particle diameter of the azomethine fluorescent pigment (Y) dispersed in the fluorescent pigment (Y) dispersion is preferably 30 nm or more and 800 nm or less, more preferably 50 nm or more and 700 nm or less, still more preferably 150 nm or more and 600 nm or less, and still more preferably 250 nm or more and 400 nm or less. The particle diameter of the azomethine fluorescent pigment (Y) can be adjusted, for example, by the method and time of the dispersion treatment.

[0115] The content of the azomethine fluorescent pigment (Y) contained in the fluorescent pigment (Y) 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.

[0116] - Pigment (G) Dispersion Preparation Step - The pigment (G) dispersion is prepared, for example, by dispersing the pigment (G) in a dispersion medium with a surfactant.

[0117] Examples of the dispersion medium used in the pigment (G) dispersion include aqueous media. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0118] Examples of the surfactant 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 mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0119] Examples of the method for dispersing the pigment (G) in the dispersion medium include a dispersion method using a rotary shear type homogenizer, a ball mill having media, a sand mill, a dyno mill, a kneader mill, etc.

[0120] The volume average particle diameter of the pigment (G) dispersed in the pigment (G) dispersion is preferably, for example, 20 nm or more and 400 nm or less, more preferably 50 nm or more and 300 nm or less, still more preferably 100 nm or more and 250 nm or less, and still more preferably 120 nm or more and 200 nm or less. The particle diameter of the pigment (G) can be adjusted, for example, by the method and time of the dispersion treatment.

[0121] The content of the pigment (G) contained in the pigment (G) 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.

[0122] -Agglomerate particle formation step- Mix a resin particle dispersion, a fluorescent pigment (Y) dispersion, a pigment (G) dispersion, and a release agent particle dispersion. Then, in the mixed dispersion, hetero-aggregate the resin particles, the azomethine fluorescent pigment (Y), the pigment (G), and the release agent particles to form aggregated particles containing the resin particles, the azomethine fluorescent pigment (Y), the pigment (G), and the release agent particles, which have a diameter close to the diameter of the target toner particles.

[0123] Specifically, for example, add a flocculant to the mixed dispersion, adjust the pH of the mixed dispersion to acidic (for example, pH 2 or more and 5 or less), add a dispersion stabilizer as necessary, and then heat to a temperature close to the glass transition temperature of the resin particles (specifically, for example, glass transition temperature of the resin particles - 30°C or more and glass transition temperature - 10°C or less) to aggregate the particles dispersed in the mixed dispersion and form aggregated particles. In the aggregated particle formation step, for example, add a flocculant to the mixed dispersion at room temperature (for example, 25°C) while stirring with a rotary shear homogenizer, adjust the pH of the mixed dispersion to acidic (for example, pH 2 or more and 5 or less), add a dispersion stabilizer as necessary, and then perform heating.

[0124] Examples of the flocculant include surfactants with opposite polarities to the surfactants contained in the mixed dispersion, inorganic metal salts, and metal complexes with a valence of 2 or more. When a metal complex is used as the flocculant, the amount of surfactant used is reduced and the charging characteristics are improved. Optionally, an additive that forms a complex or similar bond with the metal ions of the flocculant may be used together with the flocculant. As this additive, a chelating agent is preferably used.

[0125] Examples of the inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and the like. As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and the like. The addition amount of the chelating agent is preferably 0.01 part by mass or more and 5.0 parts by mass or less, more preferably 0.1 part by mass or more and less than 3.0 parts by mass, based on 100 parts by mass of the resin particles.

[0126] -Fusion and unification step- Next, the aggregated particle dispersion 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 unify the aggregated particles and form toner particles.

[0127] Through the above steps, toner particles are obtained. After obtaining the aggregated particle dispersion in which the aggregated particles are dispersed, the aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed, and aggregated so that the resin particles further adhere to the surface of the aggregated particles to form second aggregated particles, and heating is performed on the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and unify the second aggregated particles to form toner particles having a core-shell structure. Through these steps, toner particles may be manufactured.

[0128] After the fusion and unification step is completed, the toner particles in the dispersion are subjected to known washing steps, solid-liquid separation steps, and drying steps to obtain toner particles in a dried state. From the viewpoint of chargeability, it is preferable to sufficiently perform substitution washing with ion-exchanged water in the washing step. From the viewpoint of productivity, it is preferable to perform suction filtration, pressure filtration, etc. in the solid-liquid separation step. From the viewpoint of productivity, it is preferable to perform freeze drying, airflow drying, fluidized drying, vibration-type fluidized drying, etc. in the drying step.

[0129] The toner according to this embodiment is manufactured, for example, by adding and mixing an external additive to the obtained toner particles in a dry state. The mixing may be performed, for example, by a V blender, a Henschel mixer, a Lodige mixer, or the like. Further, if necessary, coarse particles of the toner may be removed using a vibrating sieve, an air classifier, or the like.

[0130] When mixing toner particles and silica particles, the weak adhesion ratio and the strong adhesion ratio of the silica particles are controlled by adjusting the rotation speed and / or the rotation time of the blender or mixer.

[0131] <Electrostatic charge image developer> The electrostatic charge image developer according to this embodiment contains at least the green toner according to this embodiment. The electrostatic charge image developer according to this embodiment may be a one-component developer containing only the green toner according to this embodiment, or may be a two-component developer in which the green toner and a carrier are mixed.

[0132] There is no particular limitation on the carrier, and known carriers can be mentioned. Examples of the carrier include a coated carrier in which a resin is coated on the surface of a core material made of magnetic powder; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a resin impregnated type carrier in which porous magnetic powder is impregnated with a resin; and the like. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with a resin.

[0133] Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and the like.

[0134] Examples of the resin for coating and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic ester copolymer, straight silicone resin containing an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenol resin, epoxy resin, acrylic resin, and the like.

[0135] The resin for coating and the matrix resin may contain other additives such as conductive particles. Examples of the conductive particles include metals such as gold, silver, and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate. Examples of the other additives include silica particles.

[0136] Examples of the method for coating the surface of the core material with a resin include a method of coating with a coating layer-forming solution in which the resin for coating and various additives (used as necessary) are dissolved in an appropriate solvent. The solvent is not particularly limited and may be selected in consideration of the type of resin to be used and the coating applicability. Specific resin coating methods include an immersion method in which the core material is immersed in the coating layer-forming solution; a spray method in which the coating layer-forming solution is sprayed onto the surface of the core material; a fluidized bed method in which the coating layer-forming solution is sprayed in a state where the core material is suspended by flowing air; a kneader coater method in which the core material of the carrier and the coating layer-forming solution are mixed in a kneader coater and then the solvent is removed; and the like.

[0137] In the two-component developer, the mixing ratio (mass ratio) of the green toner and the carrier is preferably green toner:carrier = 1:100 to 30:100, and more preferably 3:100 to 20:100.

[0138] <Image forming apparatus, image forming method> The image forming apparatus and the image forming method according to this embodiment will be described. The image forming apparatus according to this embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image carrier, a developing unit that accommodates an electrostatic charge image developer and develops the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, a transfer unit that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing unit that fixes the toner image transferred to the surface of the recording medium. And, as the electrostatic charge image developer, the electrostatic charge image developer according to this embodiment is applied.

[0139] In the image forming apparatus according to this embodiment, an image forming method (image forming method according to this embodiment) including a charging step of charging the surface of the image carrier, an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, a developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to this embodiment, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium is implemented.

[0140] The image forming apparatus according to this embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image carrier to a recording medium; an intermediate transfer type apparatus that first transfers the toner image formed on the surface of the image carrier to the surface of an intermediate transfer member and then secondarily transfers the toner image transferred to the surface of the intermediate transfer member to the surface of a recording medium; an apparatus provided with cleaning means for cleaning the surface of the image carrier after transfer of the toner image and before charging; an apparatus provided with discharging means for irradiating the surface of the image carrier with discharging light for discharging after transfer of the toner image and before charging; and other known image forming apparatuses are applied. When the image forming apparatus according to this embodiment is an intermediate transfer type apparatus, the transfer unit has a configuration including, for example, an intermediate transfer member on which a toner image is transferred to the surface, a primary transfer unit that primarily transfers the toner image formed on the surface of the image carrier to the surface of the intermediate transfer member, and a secondary transfer unit that secondarily transfers the toner image transferred to the surface of the intermediate transfer member to the surface of a recording medium.

[0141] In the image forming apparatus according to the present embodiment, for example, a portion including developing means may be a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge that houses the electrostatic charge image developer according to the present embodiment and includes developing means is preferably used.

[0142] Hereinafter, an example of the image forming apparatus according to the present embodiment will be shown, but it is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the others will be omitted from the description.

[0143] In the following description, as an example of the image forming apparatus according to the present embodiment, a six-unit tandem type image forming apparatus in which six image forming units are arranged will be described. The tandem type image forming apparatus is not limited to this, and a five-unit tandem type image forming apparatus in which five image forming units are arranged, a four-unit tandem type image forming apparatus in which four image forming units are arranged, and the like may be used.

[0144] FIG. 1 is a schematic configuration diagram showing the image forming apparatus according to the present embodiment, and is a diagram showing a six-unit tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in FIG. 1 includes first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, which are electrophotographic image forming means for outputting images of respective colors of pink (P), yellow (Y), magenta (M), cyan (C), black (K), and green (G) based on color-separated image data. These image forming units (hereinafter, may be simply referred to as "units") 10P, 10Y, 10M, 10C, 10K, and 10G are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10P, 10Y, 10M, 10C, 10K, and 10G may be process cartridges that are detachable from the image forming apparatus.

[0145] Below each of the units 10P, 10Y, 10M, 10C, 10K, and 10G, an intermediate transfer belt (an example of an intermediate transfer member) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22, a support roll 23, and an opposing roll 24 that are in contact with the inner surface of the intermediate transfer belt 20, and is configured to travel in a direction from the first unit 10P toward the sixth unit 10G. On the image holding surface side of the intermediate transfer belt 20, an intermediate transfer member cleaning device 21 is provided opposite to the drive roll 22.

[0146] To each of the developing devices (an example of developing means) 4P, 4Y, 4M, 4C, 4K, and 4G of the units 10P, 10Y, 10M, 10C, 10K, and 10G, supply of each toner of pink, yellow, magenta, cyan, black, and green stored in toner cartridges 8P, 8Y, 8M, 8C, 8K, and 8G is made.

[0147] Since the first to sixth units 10P, 10Y, 10M, 10C, 10K, and 10G have the same configuration and operation, here, the sixth unit 10G that forms a green image will be described representatively.

[0148] The sixth unit 10G has a photosensitive member 1G that acts as an image holding member. Around the photosensitive member 1G, a charging roll (an example of charging means) 2G that charges the surface of the photosensitive member 1G to a predetermined potential, an exposure device (an example of electrostatic charge image forming means) 3G that exposes the charged surface with a laser beam based on a color-separated image signal to form an electrostatic charge image, a developing device (an example of developing means) 4G that supplies toner to the electrostatic charge image to develop the electrostatic charge image, a primary transfer roll (an example of primary transfer means) 5G that transfers the developed toner image onto the intermediate transfer belt 20, and a photosensitive member cleaning device (an example of cleaning means) 6G that removes the toner remaining on the surface of the photosensitive member 1G after primary transfer are arranged in order.

[0149] The primary transfer roll 5G is disposed inside the intermediate transfer belt 20 and provided at a position facing the photoreceptor 1G. Bias power supplies (not shown) for applying a primary transfer bias are respectively connected to the primary transfer rolls 5Y, 5P, 5M, 5C, 5G, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

[0150] Hereinafter, the operation of forming a green image in the sixth unit 10G will be described. First, prior to the operation, the surface of the photoreceptor 1G is charged to a potential of -600 V to -800 V by the charging roll 2G. The photoreceptor 1G is formed by laminating a photosensitive layer on a conductive substrate (for example, having a volume resistivity of 1 × 10 -6 Ωcm or less at 20°C). This photosensitive layer is usually of high resistance (the resistance of a general resin), but has the property that when irradiated with a laser beam, the specific resistance of the irradiated portion of the photosensitive layer changes. Therefore, a laser beam is irradiated from the exposure device 3G onto the charged surface of the photoreceptor 1G in accordance with the green image data sent from a control unit (not shown). Thereby, an electrostatic charge image of the green image pattern is formed on the surface of the photoreceptor 1G.

[0151] The electrostatic charge image is an image formed on the surface of the photoreceptor 1G by charging. By the laser beam from the exposure device 3G, the specific resistance of the irradiated portion of the photosensitive layer decreases, and the charged charges on the surface of the photoreceptor 1G flow, while the charges in the portion not irradiated with the laser beam remain, thereby forming a so-called negative latent image. The electrostatic charge image formed on the photoreceptor 1G rotates to a predetermined development position as the photoreceptor 1G travels. Then, at this development position, the electrostatic charge image on the photoreceptor 1G is developed and visualized as a toner image by the developing device 4G.

[0152] Inside the developing device 4G, for example, a toner for electrostatic latent image development containing at least green toner and a carrier is accommodated. The green toner is triboelectrically charged by being agitated inside the developing device 4G, has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1G, and is held on a developer roll (an example of a developer holding member). Then, as the surface of the photoreceptor 1G passes through the developing device 4G, the green toner electrostatically adheres to the discharged latent image portion on the surface of the photoreceptor 1G, and the latent image is developed by the green toner. The photoreceptor 1G on which the green toner image is formed continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1G is conveyed to a predetermined primary transfer position.

[0153] When the green toner image on the photoreceptor 1G is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5G, and an electrostatic force from the photoreceptor 1G toward the primary transfer roll 5G acts on the toner image, and the toner image on the photoreceptor 1G is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (-) of the toner, and in the first unit 10G, it is controlled, for example, to +10 μA by a control unit (not shown).

[0154] After the toner image is transferred to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with a cleaning blade provided in the photoreceptor cleaning device 6G. The toner remaining on the photoreceptor 1G is removed and recovered by the photoreceptor cleaning device 6G.

[0155] The intermediate transfer belt 20 is sequentially conveyed through the first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, 10G, and toner images of each color are overlapped and multi-transferred.

[0156] The intermediate transfer belt 20 onto which six-color toner images are multi-transferred through the first to sixth units reaches a secondary transfer unit composed of the intermediate transfer belt 20, an opposing roll 24 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of secondary transfer means) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, a recording paper (an example of a recording medium) P is fed at a predetermined timing into a gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a supply mechanism, and a secondary transfer bias is applied to the opposing roll 24. The transfer bias applied at this time has a (-) polarity that is the same polarity as the toner (-), and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 20 is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) that detects the resistance of the secondary transfer unit, and is voltage-controlled.

[0157] After the toner image is transferred to the recording paper P, the intermediate transfer belt 20 continues to run and contacts a cleaning blade provided in the intermediate transfer body cleaning device 21. The toner remaining on the intermediate transfer belt 20 is removed and recovered by the intermediate transfer body cleaning device 21.

[0158] The recording paper P onto which the toner image is transferred is fed into a pressure contact portion (nip portion) of a pair of fixing rolls in a fixing device (an example of fixing means) 28, and the toner image is fixed onto the recording paper P to form a fixed image.

[0159] Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copiers, printers, etc. Examples of the recording medium include OHP sheets in addition to the recording paper P. 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 obtained by coating the surface of plain paper with resin or the like, art paper for printing, etc. are preferably used.

[0160] The recording paper P on which the fixing of the color image is completed is carried out toward the discharging unit, and a series of color image forming operations are terminated.

[0161] <Process cartridge, toner cartridge> The process cartridge according to the present embodiment will be described. The process cartridge according to the present embodiment contains the electrostatic charge image developer according to the present embodiment, and includes developing means for developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer, and is a process cartridge that is detachably attached to an image forming apparatus.

[0162] The process cartridge according to the present embodiment is not limited to the above configuration, and may be configured to include developing means and at least one selected from other means such as, for example, an image carrier, charging means, electrostatic charge image forming means, and transfer means, as necessary.

[0163] Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the others will be omitted from the description.

[0164] FIG. 2 is a schematic configuration diagram showing the process cartridge according to the present embodiment. The process cartridge 200 shown in FIG. 2 is configured by integrally combining and holding, for example, a photosensitive member 107 (an example of an image carrier), a charging roll 108 (an example of charging means) provided around the photosensitive member 107, a developing device 111 (an example of developing means), and a photosensitive member cleaning device 113 (an example of cleaning means) with a housing 117 provided with an attachment rail 116 and an opening 118 for exposure, and is made into a cartridge. In FIG. 2, 109 indicates an exposure device (an example of electrostatic charge image forming means), 112 indicates a transfer device (an example of transfer means), 115 indicates a fixing device (an example of fixing means), and 300 indicates a recording paper (an example of a recording medium).

[0165] Next, the toner cartridge according to the present embodiment will be described. The toner cartridge according to this embodiment is a toner cartridge that houses the green toner according to this embodiment and is detachable from the image forming apparatus. The toner cartridge houses replenishing toner for supplying to developing means provided in the image forming apparatus.

[0166] The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8P, 8M, 8C, 8G, 8K are detachable, and developing devices 4Y, 4P, 4M, 4C, 4G, 4K are connected to toner cartridges corresponding to respective colors by toner supply pipes (not shown). When the toner housed in the toner cartridge runs low, the toner cartridge is replaced. An example of the toner cartridge according to this embodiment is the toner cartridge 8G, in which the green toner according to this embodiment is housed. The toner cartridges 8P, 8Y, 8M, 8C, 8K house pink, yellow, magenta, cyan, and black toners, respectively.

Example

[0167] Hereinafter, embodiments of the invention will be described in detail by way of examples, but the embodiments of the invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are based on mass. Synthesis, processing, manufacturing, etc. were carried out at room temperature (25°C ± 3°C) unless otherwise specified.

[0168] <Production of Carrier> · Cyclohexyl methacrylate resin (weight average molecular weight 50,000): 54 parts · Carbon black (Cabot, VXC72): 6 parts · Toluene: 250 parts · Isopropyl alcohol: 50 parts The above materials and glass beads (diameter 1 mm, the same amount as toluene) were put into a sand mill and stirred at a rotational speed of 190 rpm for 30 minutes to obtain a coating agent.

[0169] 1000 parts of ferrite particles (volume average particle size: 35 μm) and 150 parts of a coating agent were charged into a kneader and mixed at room temperature (25°C) for 20 minutes. Then, the mixture was heated to 70°C and dried under reduced pressure. The dried product was cooled to room temperature (25°C), taken out from the kneader, and sieved through a mesh with an opening of 75 μm to remove coarse powder, thereby obtaining a carrier.

[0170] <Production of Silica Particles> [Silica Particles (S1)] 300 parts of methanol and 70 parts of 10% aqueous ammonia were placed in a glass reaction vessel equipped with a stirrer, a dropping nozzle, and a thermometer and mixed to obtain an alkaline catalyst solution. The alkaline catalyst solution was adjusted to 30°C, and while stirring, 169 parts of tetramethoxysilane (TMOS) and 45 parts of 8.0% aqueous ammonia were simultaneously dropped to obtain a silica particle dispersion (solid content concentration: 12.0%). Here, the dropping time was 29 minutes. Next, the silica particle dispersion was concentrated to a solid content concentration of 40% using a rotary filter to obtain a silica particle dispersion (S1). 62 parts of hexamethyldisilazane (HMDS) as a hydrophobizing agent was added to 250 parts of the silica particle dispersion (S1), the temperature was adjusted to 130°C, and the mixture was reacted for 2 hours. Then, the mixture was cooled to room temperature and spray-dried to obtain hydrophobic silica particles (S1).

[0171] [Silica Particles (S2) to (S5)] In the same manner as the production of silica particles (S1), except that the amounts of methanol, 10% aqueous ammonia, TMOS, and 8% aqueous ammonia used, the dropping times of TMOS and 8% aqueous ammonia, and the amount of HMDS used were changed to the specifications shown in Table 1, silica particles (S2) to (S5) were produced. The average primary particle size and average circularity of the silica particles are shown in Table 1.

[0172]

Table 1

[0173] <Example 1: Green Toner and Green Developer> [Preparation of Resin Particle Dispersion (1)] · Terephthalic acid: 30 mol parts · Fumaric acid: 70 mol parts · Bisphenol A ethylene oxide adduct: 5 mol parts · Bisphenol A propylene oxide adduct: 95 mol parts The above materials were charged into a flask equipped with a stirring device, a nitrogen inlet tube, a temperature sensor, and a rectification column. The temperature was raised to 220 °C over 1 hour, and after confirming that the reaction system was uniformly stirred, 1 part of titanium tetraethoxide was added to 100 parts of the above materials. The temperature was raised to 230 °C over 30 minutes while distilling off the generated water. Stirring was continued at 230 °C for 1 hour, and then the reaction system was cooled to room temperature. Thus, an amorphous polyester resin (weight average molecular weight 18,000, glass transition temperature 60 °C) was obtained. 40 parts of ethyl acetate and 25 parts of 2-butanol were charged into a reaction vessel equipped with a temperature control means and a nitrogen replacement means and mixed, and then 100 parts of the amorphous polyester resin was gradually added and dissolved. Next, 3 molar equivalents of a 10% aqueous ammonia solution were added to the acid value of the amorphous polyester resin and stirred for 30 minutes. Next, the inside of the reaction vessel was replaced with dry nitrogen, and while maintaining the temperature at 40 °C and stirring, 400 parts of ion-exchanged water was dropped at a rate of 2 parts / min to prepare a resin particle dispersion. The resin particle dispersion was cooled to room temperature and bubbled with dry nitrogen for 48 hours while stirring to remove ethyl acetate and 2-butanol to 1000 ppm or less. Ion-exchanged water was added to the resin particle dispersion to obtain a resin particle dispersion (1) with a solid content of 20%.

[0174] [Preparation of Release Agent Particle Dispersion (1)] · Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 100 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 1 part · Ion-exchanged water: 350 parts The above materials were mixed, heated to 100 °C, dispersed with a homogenizer (Ultra Turrax T50, IKA), and then dispersed with a pressure discharge type homogenizer (Gorin). The mixture was recovered when the volume average particle size reached 200 nm, and a mold release agent particle dispersion (1) with a solid content of 20% was obtained.

[0175] [Preparation of Pigment Dispersion (Y101)] · C.I. Pigment Yellow 101: 70 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume average particle size of 300 nm with a continuous kneader mill (KMC-3, Inoue Seisakusho Co., Ltd.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (Y101).

[0176] [Preparation of Pigment Dispersion (PG36)] · C.I. Pigment Green 36: 70 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume average particle size of 150 nm with a continuous kneader mill (KMC-3, Inoue Seisakusho Co., Ltd.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (PG36).

[0177] [Preparation of Green Toner Particles] · Resin particle dispersion (1): 400 parts (solid content 20%) · Mold release agent particle dispersion (1): 25 parts (solid content 20%) · Pigment dispersion (Y101): 20 parts (solid content 20%) · Pigment dispersion (PG36): 20 parts (solid content 20%) · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 12 parts (solid content 20%) The above materials were put into a round stainless steel flask, 0.1 mol / L nitric acid was added to adjust the pH to 3.5, and 30 parts of nitric acid with a 10% polyaluminum chloride concentration were added. The liquid temperature was adjusted to 30°C, and dispersion treatment was carried out using a homogenizer (Ultra Turrax T50, IKA). While stirring the inside of the flask, it was heated to 45°C in an oil bath for heating and held for 30 minutes. Next, 50 parts of the resin particle dispersion (1) (solid content 20%) were added and held for 1 hour. Then, the pH was adjusted to 8.5 using a 0.1 mol / L aqueous sodium hydroxide solution, and while continuing stirring, it was heated to 84°C and held for 2.5 hours. Then, it was cooled to room temperature at a rate of 20°C / min, subjected to solid-liquid separation, and thoroughly washed with ion-exchanged water. The solid content was vacuum dried to obtain green toner particles (1). The volume average particle diameter of the green toner particles (1) was 5.8 μm.

[0178] [Preparation of Green Toner and Green Developer] 100 parts of the green toner particles (1) and 1.7 parts of the silica particles (S1) were put into a sample mill and mixed at a rotational speed of 10,000 rpm for 30 seconds. Then, it was sieved with a vibrating sieve with a mesh opening of 45 μm to obtain externally added toner. 10 parts of the externally added toner and 100 parts of the carrier were put into a V blender and stirred for 20 minutes. Then, it was sieved with a sieve with a mesh opening of 212 μm to obtain a green developer.

[0179] <Examples 2 - 3, Comparative Examples 1 - 2> In the same manner as in Example 1, except that the silica particles (S1) were replaced with any one of the silica particles (S2) - (S5), green toner particles, green toner, and green developer were produced.

[0180] <Examples 4 - 8> In the same manner as in Example 1, except that the rotational speed and rotation time of the sample mill when mixing the green toner particles (1) and the silica particles (S1) were changed, green toner particles, green toner, and green developer were produced.

[0181] <Example 9> In the same manner as in Example 1, except that C.I. Pigment Green 7 was used instead of C.I. Pigment Green 36 in the production of the green toner particles, green toner particles, a green toner, and a green developer were produced.

[0182] <Examples 10 to 12, Comparative Examples 3 to 5> In the same manner as in Example 1, except that the amount of the pigment dispersion used was changed in the production of the green toner particles, green toner particles, a green toner, and a green developer were produced.

[0183] <Performance Evaluation> [Color Development Property] A modified model of DocuCentre Color 400 (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing device, and the toner was put into the toner cartridge. In an environment of a temperature of 22°C and a relative humidity of 55%, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Film Business Innovation Co., Ltd.), a solid green image (concentration 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ) was formed. Using a reflection spectrophotometer X-Rite 938 (X-Rite Co., Ltd.), at the central part within the solid image, the CIE1976L * a * b * values in the color space were measured. Further, the chroma C * value, a * value, and b * value were measured. Furthermore, the chroma C * was calculated from the following formula. Chroma C * ={(a * ) 2 +(b * ) 2} 0.5

[0184] The color development property was classified as follows based on the chroma C * and the lightness L * . The results are shown in Table 2. G1: Chroma C *is 97 or more, and lightness L * is 80 or more G2: Chroma C * is 95 or more, and lightness L * is 78 or more G3: Chroma C * is less than 95, and / or lightness L * is less than 78

[0185] [Reflectance] A modified machine of DocuCentreColor400 (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing unit, and the toner was put into the toner cartridge. In an environment of temperature 22°C and relative humidity 55%, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Film Business Innovation Co., Ltd.), a solid green image (density 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ) was formed. Using a reflection spectrophotometer X-Rite938 (X-Rite Co., Ltd.), the spectral reflectance (400 nm to 700 nm) was measured at the center of the solid image. The spectral reflectance at a wavelength of 530 nm was classified as follows. The results are shown in Table 2. G1: 95% or more G2: 90% or more and less than 95% G3: Less than 90%

[0186] [Image density uniformity] A modified machine of DocuCentreColor400 (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing unit, and the toner was put into the toner cartridge. In an environment of temperature 28°C and relative humidity 85% which is an environment where the toner is relatively difficult to charge, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Film Business Innovation Co., Ltd.), five solid green images (density 100%, size 5 cm × 5 cm) were formed on one sheet of paper. Using a reflection spectrophotometer X-Rite 938 (X-Rite Co., Ltd.), the image density ({(L * ) 2 +(a * ) 2 +(b * ) 2} 0.5 ) was measured at the center of each of the five solid images. The difference between the highest and lowest values among the five measured values was calculated and classified as follows. The results are shown in Table 2. A: The difference in image density is less than 1 B: The difference in image density is 1 or more and less than 3 C: The difference in image density is 3 or more

[0187] [Color dots] A modified machine of DocuCentre Color 400 (Fuji Xerox Business Innovation Co., Ltd.) was prepared, the developer was put into the developing unit, and the toner was put into the toner cartridge. In an environment of a temperature of 22 °C and a relative humidity of 55%, a green single-color halftone image (density 25%, size 5 cm × 5 cm) was formed on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Xerox Business Innovation Co., Ltd.). The halftone image was visually observed, and the number of color dots was classified as follows. The results are shown in Table 2. A: The number of color dots is 5 or less B: The number of color dots is 6 or more and 10 or less C: The number of color dots is 11 or more

[0188] The symbols in Table 2 mean the following pigments. · PY101: C.I. Pigment Yellow 101 (Radiant Color, Radglo VSF-0-01, emission peak 520 nm), one kind of azomethine fluorescent pigment (Y) · PG36: C.I. Pigment Green 36 (Toyo Color Co., Ltd., LIONOL GREEN 8624, reflection peak 510 nm, specific gravity 2.9), one kind of pigment (G) · PG7: C.I. Pigment Green 7 (Toyobo Co., Ltd., LIONOL GREEN 8390, reflection peak 500 nm, specific gravity 2.1), one kind of pigment (G)

[0189] The specific gravity of the pigment is the value measured by the following operation in accordance with 5-2-1 of JIS K 0061:2001. (1) Put 250 mL of ethyl alcohol into a pycnometer and adjust so that the meniscus is at the scale position. (2) Immerse the pycnometer in a constant temperature water bath and accurately read the position of the meniscus at the scale of the pycnometer when the liquid temperature reaches 20.0 °C ± 0.2 °C (accuracy 0.0025 mL). (3) Weigh 100 g of the sample. (4) Put the weighed sample into the pycnometer and remove the bubbles. (5) Immerse the pycnometer in the constant temperature bath and accurately read the position of the meniscus at the scale of the pycnometer when the liquid temperature reaches 20.0 °C ± 0.2 °C (accuracy 0.0025 mL). (6) Calculate the specific gravity by the following formula. · Formula: S = D / 0.9982 · Formula: D = W / (L2 - L1) Here, S is the specific gravity of the sample (20 °C), D is the density of the sample (g / cm 3 , 20 °C), 0.9982 is the density of water at 20 °C (g / cm 3 ), W is the apparent mass of the sample (g), L1 is the reading value of the meniscus before putting the sample into the pycnometer (mL, 20 °C), and L2 is the reading value of the meniscus after putting the sample into the pycnometer (mL, 20 °C).

[0190]

Table 2

[0191] <Image formation by actual machine> An electrophotographic and intermediate transfer type 6-unit tandem image forming apparatus was prepared. Each of the six developing units was filled with a developer of pink color, a developer of yellow color, a developer of magenta color, a developer of cyan color, a developer of black color, and a developer of green color (developer of Example 1). Then, an image was formed on A4-sized coated paper based on the image data obtained by color-separating RGB data into the above six colors. An image with good color reproducibility close to the original RGB data was obtained.

[0192] The green toner for developing an electrostatic charge image, the electrostatic charge image developer, the toner cartridge, the process cartridge, the image forming apparatus, and the image forming method of the present disclosure include the following aspects.

[0193] (((1))) It contains a binder resin, an azomethine fluorescent pigment having an emission peak in the wavelength range of 500 nm or more and 550 nm or less in the emission spectrum, and a non-fluorescent pigment having a reflection peak in the wavelength range of 480 nm or more and 540 nm or less in the reflection spectrum. The mass ratio of the azomethine fluorescent pigment in the green toner particles is 3% by mass or more and 20% by mass or less. Green toner particles, It includes silica particles externally added to the green toner particles. The average primary particle diameter of the silica particles is 50 nm or more and 350 nm or less. A green toner for developing an electrostatic charge image. (((2))) The mass ratio of the azomethine fluorescent pigment in the total content of the azomethine fluorescent pigment and the non-fluorescent pigment is 30% by mass or more and 90% by mass or less. The green toner for developing an electrostatic charge image according to ((1)). (((3))) Based on 100 parts by mass of the green toner particles, 0.5 part by mass or more and 5 parts by mass or less of the silica particles are included. The green toner for developing an electrostatic charge image according to ((1)) or ((2)). (((4))) When the green toner for electrostatic charge image development is dispersed in water containing a surfactant, the silica particles detached from the green toner particles are 10% by mass or more and 30% by mass or less of the silica particles externally added to the green toner particles. ((1)))~(((3))) Any one of the green toners for electrostatic charge image development according to any one of ((5))) When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 40 W, a frequency of 20 kHz, and for 10 minutes, the silica particles that do not detach from the green toner particles are 1% by mass or more and 5% by mass or less of the silica particles externally added to the green toner particles. ((1)))~(((4))) Any one of the green toners for electrostatic charge image development according to any one of ((6))) The azomethine fluorescent pigment is C.I. Pigment Yellow 101. ((1)))~(((5))) Any one of the green toners for electrostatic charge image development according to any one of ((7))) The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59, and C.I. Pigment Blue 76. ((1)))~(((6))) Any one of the green toners for electrostatic charge image development according to any one of

[0194] ((8))) ((1)))~(((7))) Any one of the electrostatic charge image developers containing the green toner for electrostatic charge image development according to any one of ((9))) ((1)))~(((7))) Any one of the toner cartridges that contain the green toner for electrostatic charge image development according to any one of and are detachable from an image forming apparatus. ((10))) Developing means for accommodating the electrostatic charge image developer described in ((8)) and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, A process cartridge detachable from the image forming apparatus. (((11))) An image carrier, Charging means for charging the surface of the image carrier, Electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the image carrier, Developing means for accommodating the electrostatic charge image developer described in ((8)) and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, Transferring means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus comprising the above. (((12))) A charging step of charging the surface of the image carrier, An electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, A developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer described in ((8)), A transferring step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, A fixing step of fixing the toner image transferred to the surface of the recording medium, An image forming method having the above. (((13))) An electrophotographic image forming apparatus including first to sixth image forming units for forming images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming unit for forming the green image accommodates the electrostatic charge image developer described in ((8)). An image forming apparatus. (((14))) It has first to sixth image forming steps of an electrophotographic method for forming images of respective colors of pink, yellow, magenta, cyan, black, and green, and an image forming step for forming the green image uses the electrostatic charge image developer described in (((8))). Image forming method.

[0195] (((1))), (((2))), (((6))), or (((7))) provides a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the average primary particle diameter of silica particles as an external additive is less than 50 nm. (((3))) provides a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the external addition amount of silica particles is less than 0.5 part by mass. (((4))) provides a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the silica particles detached from the green toner particles are less than 10% by mass. (((5))) provides a green toner for electrostatic charge image development in which color spots are less likely to occur in an image, as compared with a green toner for electrostatic charge image development in which the silica particles that do not detach from the green toner particles are more than 5% by mass.

[0196] (((8))) provides an electrostatic charge image developer in which color spots are less likely to occur in an image, as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. (((9))) provides a toner cartridge in which color spots are less likely to occur in an image, as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. (((10))) provides a process cartridge in which color spots are less likely to occur in an image, as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. According to ((11)) or ((13)), an image forming apparatus is provided in which color spots are less likely to occur in an image as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm. According to ((12)) or ((14)), an image forming method is provided in which color spots are less likely to occur in an image as compared with the case where the average primary particle diameter of silica particles as an external additive of a green toner for electrostatic charge image development is less than 50 nm.

Explanation of Signs

[0197] 1P, 1Y, 1M, 1C, 1K, 1G Photoreceptor (an example of an image holding member) 2P, 2Y, 2M, 2C, 2K, 2G Charging roll (an example of a charging means) 3P, 3Y, 3M, 3C, 3K, 3G Exposure device (an example of an electrostatic charge image forming means) 4P, 4Y, 4M, 4C, 4K, 4G Developing device (an example of a developing means) 5P, 5Y, 5M, 5C, 5K, 5G Primary transfer roll (an example of a primary transfer means) 6P, 6Y, 6M, 6C, 6K, 6G Photoreceptor cleaning device (an example of a cleaning means) 8P, 8Y, 8M, 8C, 8K, 8G Toner cartridge 10P, 10Y, 10M, 10C, 10K, 10G Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member) 21 Intermediate transfer member cleaning device 22 Driving roll 23 Support roll 24 Opposing roll 26 Secondary transfer roll (an example of a secondary transfer means) 28 Fixing device (an example of a fixing means) P Recording paper (an example of a recording medium)

[0198] 107 Photoreceptor (an example of an image holding member) 108 Charging roll (an example of a charging means) 109 Exposure device (an example of an electrostatic charge image forming means) 111 Developing device (an example of developing means) 112 Transfer device (an example of transfer means) 113 Photoconductor cleaning device (an example of cleaning means) 115 Fixing device (an example of fixing means) 116 Mounting rail 117 Housing 118 Opening for exposure 200 Process cartridge 300 Recording paper (an example of recording medium)

Claims

1. A green toner particle containing a binder resin, an azomethine fluorescent pigment having an emission peak in the region of 500 nm or more and 550 nm or less in the emission spectrum wavelength, and a non-fluorescent pigment having a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum wavelength, wherein the mass ratio of the azomethine fluorescent pigment in the green toner particle is 3% by mass or more and 20% by mass or less, and silica particles externally added to the green toner particle, wherein the average primary particle diameter of the silica particles is 50 nm or more and 350 nm or less. A green toner for electrostatic charge image development.

2. The mass ratio of the azomethine fluorescent pigment in the total of the content of the azomethine fluorescent pigment and the content of the non-fluorescent pigment is 30% by mass or more and 90% by mass or less. The green toner for electrostatic charge image development according to Claim 1.

3. The green toner for electrostatic charge image development according to Claim 1, containing 0.5 part by mass or more and 5 parts by mass or less of the silica particles with respect to 100 parts by mass of the green toner particles. The green toner for electrostatic charge image development according to Claim 1.

4. When the green toner for electrostatic charge image development is dispersed in water containing a surfactant, the silica particles detached from the green toner particles are 10% by mass or more and 30% by mass or less of the silica particles externally added to the green toner particles. The green toner for electrostatic charge image development according to Claim 1.

5. When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 40 W, a frequency of 20 kHz, and for 10 minutes, the silica particles not detached from the green toner particles are 1% by mass or more and 5% by mass or less of the silica particles externally added to the green toner particles. The green toner for electrostatic charge image development according to Claim 1.

6. The azomethine fluorescent pigment is C.I. Pigment Yellow 101. The green toner for electrostatic charge image development according to Claim 1.

7. The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59, and C.I. Pigment Blue 76. The green toner for electrostatic charge image development according to Claim 1.

8. An electrostatic charge image developer containing the green toner for electrostatic charge image development according to any one of Claims 1 to 7.

9. ​ A toner cartridge that houses the green toner for electrostatic charge image development according to any one of claims 1 to 7 and is detachable from an image forming apparatus.

10. A process cartridge that houses the electrostatic charge image developer according to claim 8 and includes a developing unit that develops an electrostatic charge image formed on the surface of an image carrier as a toner image using the electrostatic charge image developer. The process cartridge is detachable from the image forming apparatus.

11. An image carrier, A charging unit that charges the surface of the image carrier, An electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image carrier, A developing unit that houses the electrostatic charge image developer according to claim 8 and develops an electrostatic charge image formed on the surface of the image carrier as a toner image using the electrostatic charge image developer, A transfer unit that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, A fixing unit that fixes the toner image transferred to the surface of the recording medium, An image forming apparatus comprising the above components.

12. A charging step of charging the surface of the image carrier, An electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image using the electrostatic charge image developer according to claim 8, A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, A fixing step of fixing the toner image transferred to the surface of the recording medium, An image forming method having the above steps.

13. An electrophotographic image forming apparatus including first to sixth image forming units that form images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming unit that forms the green image houses the electrostatic charge image developer according to claim 8. The image forming apparatus.

14. An electrophotographic image forming method having first to sixth image forming steps that form images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming step that forms the green image uses the electrostatic charge image developer according to claim 8. The image forming method.

Images