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

Abstract

To provide a green toner for electrostatic image development that can form a green image with high brightness and saturation. [Solution] The green toner for electrostatic image development contains green toner particles. The green toner particles contain a binder resin, CI pigment yellow 101, and at least one non-fluorescent pigment selected from the group consisting of CI pigment green 7, CI pigment green 36, CI pigment green 58, CI pigment green 59, and CI pigment blue 76, wherein the mass-based ratio M2 / M1 of the content M1 of CI pigment yellow 101 to the content M2 of the non-fluorescent pigment is 0.05 or more and 1.5 or less, and the total content of CI pigment yellow 101 and the non-fluorescent pigment relative to the total green toner particles is 5% by mass or more and 15% by mass or less.

Description

[Technical Field]

[0001] This disclosure relates to green toner particles, green toner for electrostatic image development, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method. [Background technology]

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

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

[0004] Patent Document 3 discloses a toner for developing electrostatic images, which contains a yellow non-fluorescent dye whose absorption spectrum peak wavelength is in the wavelength range of 400 to 480 nm and a fluorescent dye whose emission spectrum peak wavelength is in the wavelength range of 480 to 560 nm, wherein the content of the non-fluorescent dye is 2 to 8 parts by mass per 100 parts by mass of binder resin, and the content of the fluorescent dye is 0.05 to 0.2 parts by mass per 100 parts by mass of binder resin, and the content ratio expressed by the formula (content of non-fluorescent dye / content of fluorescent dye) is in the range of 15 to 150.

[0005] Patent Document 4 specifies that the mass-based content of coloring pigments and fluorescent dyes is W G , W F When that happens, W G ×0.5>W F >W G The ×0.025 requirement is met, and the absorption peak wavelength of the coloring pigment is P G The emission peak wavelength of the fluorescent dye is set to P FWhen P G <P F toners satisfying the requirements are disclosed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] The image display unit of an electronic device generally uses the so-called RGB color mode, which represents colors by a combination of three colors: red (R), green (G), and blue (B). On the other hand, electrophotographic image formation generally uses the so-called CMYK color mode, which represents colors by a combination of four colors: cyan (C), magenta (M), yellow (Y), and black (K). When an image represented 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.

[0008] For the purpose of enhancing the color reproducibility of green, pink, or orange in electrophotographic image formation, green toners, pink toners, or orange toners have been developed. As green toners, toners containing a yellow fluorescent dye (e.g., C.I. Solvent Green 5) and a green pigment or a blue pigment are known. However, since fluorescent dyes generally exhibit concentration quenching where luminescence decays as the concentration increases, it is difficult to reproduce colors with higher brightness and higher chroma in green toners containing a fluorescent dye and a pigment.

[0009] This disclosure was made under the circumstances described above. The object of this disclosure is to provide a green toner for electrostatic image development that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. This disclosure is in accordance with CIE1976L * a * b * Lightness L in a color system * The value is 70 or higher, and the saturation C * The objective is to provide a green toner capable of forming a green image in which the h-value is 85 or higher and the h-value is between 128.5° and 144.5°. This disclosure relates to the color sample TOKA FLASH VIVA DX 650 and CIE1976L * a * b * The objective is to provide a green toner capable of forming a green image with a color difference ΔE of 13.5 or less in the color system. [Means for solving the problem]

[0010] The means for solving the aforementioned problem include the following embodiments.

[0011] <1> Binding resin and an azomethine fluorescent pigment having an emission peak in the emission spectrum wavelength region of 500 nm to 550 nm, A non-fluorescent pigment having a reflectance peak in the region of the reflectance spectrum between 480 nm and 540 nm wavelengths, The mass-based ratio M2 / M1 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 0.05 or more and 1.5 or less. The total content of the azomethine fluorescent pigment and the non-fluorescent pigment relative to the total green toner particles is 5% by mass or more and 15% by mass or less. Green toner particles, Includes a green toner for electrostatic image development. <2> The mass-based ratio M2 / M1 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 0.1 or more and 1.0 or less. The total content of the azomethine fluorescent pigment and the non-fluorescent pigment relative to the entire green toner particles is 10% by mass or more and 15% by mass or less. <1> The green toner for developing electrostatic images as described above. <3> The wavelength difference between the emission peak of the azomethine fluorescent pigment with the highest content among the azomethine fluorescent pigments contained in the green toner particles and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 40 nm or less. <1> or <2> The green toner for developing electrostatic images as described above. <4> The wavelength difference between the emission peak of the azomethine fluorescent pigment with the highest content among the azomethine fluorescent pigments contained in the green toner particles and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 20 nm or less. <1> or <2> The green toner for developing electrostatic images as described above. <5> The azomethine fluorescent pigment is CI Pigment Yellow 101. <1> ~ <4> A green toner for electrostatic image development as described in any one of the items. <6> The non-fluorescent pigment is at least one selected from the group consisting of CI pigment green 7, CI pigment green 36, CI pigment green 58, CI pigment green 59, and CI pigment blue 76. <1> ~ <5> A green toner for electrostatic image development as described in any one of the items. <7> The ratio D1 / D2 of the volume average particle size D1 of the azomethine fluorescent pigment to the volume average particle size D2 of the non-fluorescent pigment is 1 or more and 3 or less. <1> ~ <6> A green toner for electrostatic image development as described in any one of the items. <8> The volume-average particle size D1 of the azomethine fluorescent pigment is 50 nm or more and 800 nm or less. <1> ~ <7> A green toner for electrostatic image development as described in any one of the items. <9> The volume-average particle size D2 of the non-fluorescent pigment is 50 nm or more and 300 nm. <1> ~ <8> A green toner for electrostatic image development as described in any one of the items. <10-0> When a solid image is formed on coated paper, the color sample TOKA FLASH VIVA DX 650 and CIE1976L * a * b * The color difference ΔE in the color system is 13.5 or less. <1> ~ <9> A green toner for electrostatic image development as described in any one of the items.

[0012] <10> The green toner particles include a binder resin, an azomethine fluorescent pigment having an emission peak in the wavelength region of 500 nm to 550 nm in the emission spectrum, and a non-fluorescent pigment having a reflectance peak in the wavelength region of 480 nm to 540 nm in the reflectance spectrum. When a solid image is formed on coated paper, the color sample TOKA FLASH VIVA DX 650 and CIE1976L * a * b * The color difference ΔE in the color system is 13.5 or less. Green toner for developing electrostatic images. <11> The azomethine fluorescent pigment is CI Pigment Yellow 101. <10> The green toner for developing electrostatic images as described above. <12> The non-fluorescent pigment is at least one selected from the group consisting of CI pigment green 7, CI pigment green 36, CI pigment green 58, CI pigment green 59, and CI pigment blue 76. <10> or <11> The green toner for developing electrostatic images as described above.

[0013] <13> <1> ~ <12> A electrostatic image developer containing the green toner for electrostatic image development described in either item <10-0>. <14> <1> ~ <12> A toner cartridge containing the electrostatic image developing green toner described in either item <10-0>, which is attached to and detached from an image forming apparatus. <15> <13> The development means contains the electrostatic image developer described above, and develops the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, A process cartridge that is attached to and detached from an image forming apparatus. <16> Image holder and, A charging means for charging the surface of the image holder, A means for forming an electrostatic image on the surface of the charged image holder, <13> A developing means containing the electrostatic image developer described above, and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus equipped with the following features. <17> A charging step in which the surface of the image holder is charged, A step of forming an electrostatic image on the surface of the charged image holder, <13> A developing step in which the electrostatic image formed on the surface of the image holder is developed as a toner image using the electrostatic image developer described above, A transfer step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium, A fixing step for fixing the toner image transferred to the surface of the recording medium, An image forming method having the following characteristics. <18> It comprises first to sixth image forming units of an electrophotographic method that form images of pink, yellow, magenta, cyan, black, and green, The image forming unit that forms the aforementioned green image <13> Containing the electrostatic image developer described above, Image forming apparatus. <19> The system has first to sixth image forming steps using an electrophotographic method to form images of pink, yellow, magenta, cyan, black, and green. The image forming process that forms the aforementioned green image <13> Use the electrostatic image developer described above. Image forming method. [Effects of the Invention]

[0014] <1> , <2> , <5> , <6> , <8> or <9> According to the invention, a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. <3> According to the invention, a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the wavelength difference between the emission peak of the azomethine fluorescent pigment and the reflection peak of the non-fluorescent pigment is greater than 40 nm. <4> According to the invention, a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the wavelength difference between the emission peak of the azomethine fluorescent pigment and the reflection peak of the non-fluorescent pigment is greater than 20 nm. <7> According to the invention, a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to cases where the ratio D1 / D2 of the volume average particle size D1 of the azomethine fluorescent pigment to the volume average particle size D2 of the non-fluorescent pigment is less than 1 or greater than 3. <10> , <11> , <12> Alternatively, according to the invention related to <10-0>, a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the color difference ΔE with the color sample TOKA FLASH VIVA DX 650 is greater than 13.5.

[0015] <13> According to the invention, an electrostatic image developer is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. <14> According to the invention, a toner cartridge is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. <15> According to the invention, a process cartridge is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. <16> According to the invention, an image forming apparatus is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. <17> According to the invention, an image forming method is provided that can form a green image with higher brightness and saturation compared to the case where the yellow fluorescent colorant is CI Solvent Green 5. <18> According to the invention, an image forming apparatus with a wide reproducible color gamut is provided. <19> According to the invention, an image forming method is provided that allows for the reproduction of a wide color gamut. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram showing an example of an image forming apparatus according to this embodiment. [Figure 2] This is a schematic diagram showing an example of a process cartridge that can be attached to and detached from the image forming apparatus according to this embodiment. [Modes for carrying out the invention]

[0017] The embodiments of this disclosure are described below. These descriptions and embodiments are illustrative and do not limit the scope of the embodiments.

[0018] In this disclosure, the numerical range indicated using "~" represents a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples.

[0019] In this disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, provided that their objectives are achieved.

[0020] When embodiments are described in this disclosure with reference to the drawings, the configuration of such embodiments is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each figure are conceptual, and the relative relationships between the components are not limited thereto.

[0021] In this disclosure, each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition in this disclosure, if there are multiple types of the substance corresponding to each component in the composition, it means the total amount of those multiple types of substances present in the composition unless otherwise specified. In this disclosure, each component may contain multiple types of particles. If multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to the value for a mixture of such multiple types of particles present in the composition, unless otherwise specified.

[0022] In this disclosure, "(meth)acrylic" is a term that includes both acrylic and methacrylic, and "(meth)acrylate" is a term that includes both acrylate and methacrylate.

[0023] In this disclosure, "electrostatic image developing toner" is also referred to as "toner," "electrostatic image developing green toner" is also referred to as "green toner," "electrostatic image developer" is also referred to as "developer," and "electrostatic image developing carrier" is also referred to as "carrier."

[0024] <Green toner for developing electrostatic images> In this disclosure, "green toner" means toner in which the hue angle h of a solid image (100% density image) formed on coated paper is 128.5° or more and 144.5° or less. The hue angle h is defined in CIE1976L * a * b * a in color system * Value and b * This is the angle calculated from the value using the following formula. Hue angle h=tan -1 (b * / a * ) In this disclosure, the hue angle h of the solid image 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.

[0025] In this disclosure, the solid image (100% density image) formed by green toner on coated paper is CIE1976L * a * b * Lightness L in a color system * The value is 70 or higher and the saturation is C * It is preferable that the value is 85 or higher. Saturation C * CIE1976L * a * b * a in color system * Value and b * This value is calculated from the given value using the following formula. Saturation C * ={(a * ) 2 +(b * ) 2} 0.5

[0026] In this disclosure, a fluorescent pigment is a pigment that emits light in response to external light energy, and a non-fluorescent pigment is a pigment that does not emit light in response to external light energy. Generally, fluorescent pigments exhibit color through both reflected and emitted light, while non-fluorescent pigments exhibit color through reflected light only.

[0027] The green toner according to this embodiment includes green toner particles. The green toner particles include a binder resin, an azomethine fluorescent pigment having an emission peak in the wavelength region of 500 nm to 550 nm in the emission spectrum, and a non-fluorescent pigment having a reflectance peak in the wavelength region of 480 nm to 540 nm in the reflectance spectrum. In other words, the green toner particles in this embodiment are toner particles containing a yellow fluorescent pigment and a green or blue pigment.

[0028] Hereinafter, "azomethine fluorescent pigments having an emission peak in the emission spectrum wavelength region of 500 nm to 550 nm" will be referred to as "azomethine fluorescent pigment (Y)," and "non-fluorescent pigments having a reflectance peak in the reflectance spectrum wavelength region of 480 nm to 540 nm" will be referred to as "pigment (G)."

[0029] In the first embodiment, the green toner particles have a mass-based ratio M2 / M1 of the content M1 of azomethine fluorescent pigment (Y) to the content M2 of pigment (G), which is between 0.05 and 1.5. If the ratio M2 / M1 is less than 0.05, the color of the green image will shift towards yellow. If the ratio M2 / M1 is greater than 1.5, the color of the green image will shift towards blue. From the viewpoint of matching the hue of the green image to the color sample TOKA FLASH VIVA DX 650, the ratio M2 / M1 should be between 0.05 and 1.5, preferably between 0.1 and 1.0, and more preferably between 0.3 and 0.8.

[0030] In the first embodiment, the green toner particles have a total content of azomethine fluorescent pigment (Y) and pigment (G) of 5% by mass or more and 15% by mass or less relative to the total green toner particles. If the total content of both pigments is less than 5% by mass, the saturation of the green image will be poor. From the viewpoint of improving the saturation of the green image, the total content of both pigments should be 5% by mass or more, preferably 8% by mass or more, and more preferably 10% by mass or more. If the total content of both pigments exceeds 15% by mass, the brightness of the green image will be poor. From the viewpoint of improving the brightness of the green image, the total content of both pigments should be 15% by mass or less, preferably 14% by mass or less, and more preferably 12% by mass or less.

[0031] In the first embodiment, the wavelength difference between the emission peak of the azomethine fluorescent pigment (Y) with the highest content among the azomethine fluorescent pigments (Y) contained in the green toner particles and the reflection peak of the pigment (G) with the highest content among the pigments (G) contained in the green toner particles 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 better; 30 nm or less is more preferable, 20 nm or less is even more preferable, 10 nm or less is even more preferable, 5 nm or less is even more preferable, and 0 nm is ideal.

[0032] 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 the first 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 better; 30 nm or less is more preferable, 20 nm or less is even more preferable, 10 nm or less is even more preferable, 5 nm or less is even more preferable, and 0 nm is ideal.

[0033] The green toner according to the second embodiment, when a solid image (100% density image) is formed on coated paper, compares to the color sample TOKA FLASH VIVA DX 650 (T&K TOKA Corporation) with CIE1976L * a * b *The color difference ΔE in the color system is 13.5 or less. A smaller color difference ΔE is preferable, preferably 10 or less, more preferably 6.5 or less, even more preferably 3 or less, even more preferably 1 or less, and ideally 0.

[0034] In the second embodiment, CIE1976L relates to green toner. * a * b * The color difference ΔE between the color sample TOKA FLASH VIVA DX 650 (T&K TOKA Corporation) in the color system is defined by the following formula.

[0035]

number

[0036] In the above formula, L1, a1, b1 and L2, a2, b2 are CIE1976L * a * b * L in color systems * value, a * value, b * These are the values. L1, a1, and b1 are the L values ​​of the color sample TOKA FLASH VIVA DX 650. * value, a * value, b * These are values ​​obtained by measuring the color sample TOKA FLASH VIVA DX 650 with a reflectance spectrodensitometer. L2, a2, and b2 are the L values ​​of the image formed by the green toner. * value, a * value, b * This is a value obtained by measuring the image with a reflectance spectrophotometer. The color sample TOKA FLASH VIVA DX 650 (T&K TOKA Corporation) is a color sample with an image formed on coated paper, and the color difference ΔE is also measured after the image formed with green toner is formed on coated paper.

[0037] In the second embodiment, the green toner CIE1976L * a * b *The coordinate values ​​of the color system are measured using the following method. After mixing the green toner sample with a carrier, it was placed in the developer unit of the image forming apparatus and fixed onto coated paper at a fixing temperature of 180°C, resulting in a toner load of 4.0 g / m². 2 A solid image (image with 100% density) is formed. CIE1976L is used to create the solid image. * a * b * The coordinate values ​​of the color system were measured at 10 random locations using a reflectance spectrophotometer, L * value, a * Value and b * Calculate the average value.

[0038] In the second embodiment, the green toner particles preferably have a mass-based ratio M2 / M1 of the content M1 of azomethine fluorescent pigment (Y) to the content M2 of pigment (G) of 0.05 or more and 1.5 or less, more preferably 0.1 or more and 1.0 or less, and even more preferably 0.3 or more and 0.8 or less. In the second embodiment, the green toner particles preferably have a total content of azomethine fluorescent pigment (Y) and pigment (G) of 5% by mass or more and 15% by mass or less relative to the total green toner particles, more preferably 8% by mass or more and 14% by mass or less, and even more preferably 10% by mass or more and 12% by mass or less.

[0039] In the second embodiment, the wavelength difference between the emission peak of the azomethine fluorescent pigment (Y) with the highest content among the azomethine fluorescent pigment (Y) contained in the green toner particles and the reflection peak of the pigment (G) with the highest content among the pigments (G) contained in the green toner particles is preferably 40 nm or less, more preferably 30 nm or less, even more preferably 20 nm or less, even more preferably 10 nm or less, even more preferably 5 nm or less, and ideally 0 nm.

[0040] In all combinations of the emission peak of the azomethine fluorescent pigment (Y) and the reflectance peak of the pigment (G) contained in the green toner particles in the second embodiment, the wavelength difference between the emission peak and the reflectance peak is preferably 40 nm or less, more preferably 30 nm or less, even more preferably 20 nm or less, even more preferably 10 nm or less, even more preferably 5 nm or less, and ideally 0 nm.

[0041] In the second embodiment, the wavelength difference between the emission peak of the azomethine fluorescent pigment (Y) with the highest content among the azomethine fluorescent pigment (Y) contained in the green toner particles and the reflection peak of the pigment (G) with the highest content among the pigments (G) contained in the green toner particles is preferably 0 nm to 30 nm, and more preferably 5 nm to 20 nm, from the viewpoint of achieving both high brightness and saturation of the green image and low color difference ΔE. In all combinations of the emission peak of the azomethine fluorescent pigment (Y) and the reflectance peak of the pigment (G) contained in the green toner particles in the second embodiment, the wavelength difference between the emission peak and the reflectance peak is preferably 0 nm or more and 30 nm or less, and more preferably 5 nm or more and 20 nm or less.

[0042] In the first and second embodiments of the green toner, it is preferable that the reflectance of the reflectance peak in the spectral reflectance spectrum of a solid image formed on coated paper is 70% or more.

[0043] The configuration of the green toner according to this embodiment will be described in detail below.

[0044] [Green Toner Particles] Green toner particles are composed of a binder resin, azomethine fluorescent pigment (Y), and pigment (G), and optionally include a mold release agent and other additives.

[0045] -Azomethine fluorescent pigment (Y)- The azomethine fluorescent pigment (Y) has an emission peak in the wavelength region of 500 nm to 550 nm in its emission spectrum. The emission peak of the azomethine fluorescent pigment (Y) is preferably in the wavelength region of 505 nm to 540 nm, more preferably in the wavelength region of 510 nm to 535 nm, and even more preferably in the wavelength region of 515 nm to 530 nm.

[0046] Azomethine fluorescent pigment (Y) has an azomethine structure (i.e., -R 1 C=N-, R 1 A pigment has a hydrogen atom or a monovalent substituent in its molecule. As an azomethine fluorescent pigment (Y), it must be bisazomethine, i.e., -R 1 C=NN=CR 2 -(R 1 and R 2 Preferably, each of these compounds independently has a hydrogen atom or a monovalent substituent in its molecule.

[0047] Examples of azomethine fluorescent pigments (Y) include the following azomethine compounds (1) to (3).

[0048] [ka]

[0049] The emission peak of azomethine compound (1) is 520 nm. The emission peak of azomethine compound (2) is 510 nm. The emission peak of azomethine compound (3) is 520 nm.

[0050] The azomethine fluorescent pigment (Y) is preferably at least one selected from the group consisting of azomethine compound (1), azomethine compound (2), and azomethine compound (3).

[0051] As the azomethine fluorescent pigment (Y), CI Pigment Yellow 101 is preferred. CI Pigment Yellow 101 is an azomethine compound (1).

[0052] The volume-average particle size D1 of the azomethine fluorescent pigment (Y) is preferably 50 nm to 800 nm, more preferably 150 nm to 600 nm, and even more preferably 250 nm to 400 nm, from the viewpoint of achieving a good balance of dispersibility in toner particles, color development on the recording medium, and fixation on the recording medium. The volume-average particle size of a pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction particle size distribution analyzer (e.g., LA-700 from Horiba, Ltd.). The volume-based particle size distribution is plotted from the smallest particle size side, and the particle size at which the cumulative total reaches 50% is defined as the volume-average particle size.

[0053] -Pigment (G)- Pigment (G) has a reflectance peak in the region of the reflectance spectrum between 480 nm and 540 nm. Preferably, the reflectance peak of pigment (G) is in the region of 485 nm and 535 nm, more preferably in the region of 490 nm and 530 nm, and even more preferably in the region of 495 nm and 525 nm.

[0054] Examples of pigment (G) include halide phthalocyanine compounds and triphenylmethane dye lake pigments. Halide phthalocyanine compounds are preferred as pigment (G).

[0055] As the pigment (G), halogenated phthalocyanine compounds are preferred, and at least one selected from the group consisting of copper phthalocyanine halide and zinc phthalocyanine halide is preferred. Examples of copper phthalocyanine halides include CI Pigment Green 7 (reflection peak 500 nm), CI Pigment Green 36 (reflection peak 510 nm), and CI Pigment Blue 76 (reflection peak 490 nm). Examples of zinc halide phthalocyanines include CI Pigment Green 58 (reflection peak 515 nm) and CI Pigment Green 59 (reflection peak 520 nm).

[0056] The pigment (G) is preferably at least one selected from the group consisting of CI Pigment Green 7, CI Pigment Green 36, CI Pigment Green 58, CI Pigment Green 59, and CI Pigment Blue 76.

[0057] The volume-average particle size D2 of the pigment (G) is preferably 50 nm to 300 nm, more preferably 100 nm to 250 nm, and even more preferably 120 nm to 200 nm, from the viewpoint of achieving a good balance of dispersibility in toner particles, color development on the recording medium, and fixation to the recording medium. The volume-average particle size of a pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction particle size distribution analyzer (e.g., LA-700 from Horiba, Ltd.). The volume-based particle size distribution is plotted from the smallest particle size side, and the particle size at which the cumulative total reaches 50% is defined as the volume-average particle size.

[0058] The ratio D1 / D2 of the volume-average particle size D1 of the azomethine fluorescent pigment (Y) to the volume-average particle size D2 of the pigment (G) is preferably 1 to 3, more preferably 1.2 to 2.5, and even more preferably 1.5 to 2, from the viewpoint of increasing the brightness and saturation of the green image.

[0059] Green toner particles may contain other colorants besides azomethine fluorescent pigment (Y) and pigment (G). The total amount of azomethine fluorescent pigment (Y) and pigment (G) in the total colorant contained in the green toner particles is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass.

[0060] -Binding resin- Examples of binder resins include vinyl resins consisting of monomer homopolymers of styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), etc., or copolymers of two or more of these monomers. Examples of binder resins include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin; mixtures of these with the aforementioned vinyl resins; and graft polymers obtained by polymerizing vinyl monomers in the presence of these. These binding resins may be used individually or in combination of two or more types.

[0061] Polyester resin is preferred as the binder resin. Examples of polyester resins include well-known polyester resins.

[0062] Examples of polyester resins include condensation polymers of polycarboxylic acids and polyhydric alcohols. Commercially available polyester resins may be used, or synthetically produced ones may be used.

[0063] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or their lower alkyl esters (e.g., with 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids. As the polycarboxylic acid, a trivalent or higher carboxylic acid with a crosslinked or branched structure may be used in combination with the dicarboxylic acid. Examples of trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, their anhydrides, or their lower alkyl esters (e.g., having 1 to 5 carbon atoms). Polycarboxylic acids may be used individually or in combination of two or more.

[0064] Examples of polyhydric alcohols include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, aromatic diols and alicyclic diols are preferred as polyhydric alcohols, and aromatic diols are more preferred. As for the polyhydric alcohol, a trihydric or higher polyhydric alcohol with a cross-linked or branched structure may be used in combination with the diol. Examples of trihydric or higher polyhydric alcohols include glycerin, trimethylolpropane, and pentaerythritol. Polyhydric alcohols may be used individually or in combination of two or more types.

[0065] The glass transition temperature (Tg) of the polyester resin is preferably 50°C to 80°C, and more preferably 50°C to 65°C. The glass transition temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, from the "extracorporeal glass transition onset temperature" described in the method for determining the glass transition temperature in JIS K7121-1987 "Method for Measuring the Transition Temperature of Plastics".

[0066] The weight-average molecular weight (Mw) of the polyester resin is preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000. The number-average molecular weight (Mn) of the polyester resin is preferably between 2,000 and 100,000. The molecular weight distribution (Mw / Mn) of the polyester resin is preferably 1.5 to 100, and more preferably 2 to 60. Weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). GPC molecular weight measurement is performed using a Tosoh GPC-HLC-8120GPC analyzer, a Tosoh TSKgel SuperHM-M (15cm) column, and THF solvent. The weight-average molecular weight and number-average molecular weight are calculated from these measurement results using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples.

[0067] Polyester resins can be obtained by known manufacturing methods. Specifically, for example, they can be obtained by a method in which the polymerization temperature is set to 180°C or higher and 230°C or lower, and the reaction system is subjected to reduced pressure as needed, while removing water and alcohol generated during condensation. If the monomers of the raw materials do not dissolve or miscible at the reaction temperature, a high-boiling point solvent may be added as a solubilizer to dissolve them. In this case, the polycondensation reaction should be carried out while distilling off the solubilizer. If there are monomers with poor miscibility, it is advisable to condense the poorly miscible monomers with the acid or alcohol to be polycondensed with them beforehand, and then polycondense them with the main component.

[0068] The binder resin content is preferably 40% to 95% by mass, more preferably 50% to 90% by mass, and even more preferably 60% to 85% by mass, relative to the total toner particles.

[0069] -Release agent- Examples of release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum-based waxes such as montan wax; and ester waxes such as fatty acid esters and montanic acid esters. However, the release agents are not limited to these.

[0070] The melting temperature of the release agent is preferably 50°C to 110°C, and more preferably 60°C to 100°C. The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) using the "melting peak temperature" described in JIS K7121-1987 "Method for determining the transition temperature of plastics".

[0071] The release agent content 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, relative to the total toner particles.

[0072] -Other additives- Other known additives include, for example, magnetic materials, charge control agents, and inorganic powders. These additives are included in the toner particles as internal additives.

[0073] -Characteristics of toner particles, etc.- The toner particles may be single-layer toner particles, or they may be toner particles with a so-called core-shell structure, consisting of a core (core particle) and a coating layer (shell layer) that covers the core. The core-shell structure of the toner particles may consist of, for example, a core made up of a binder resin and, if necessary, other additives such as a colorant and a release agent, and a coating layer made up of a binder resin.

[0074] The volume-average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

[0075] The average particle size and particle size distribution indices of toner particles are measured using the Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte is measured using the ISOTON-II (manufactured by Beckman Coulter). For measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate) as a dispersant. This is then added to 100 ml to 150 ml of electrolyte. The electrolyte containing the suspended sample is dispersed in an ultrasonic disperser for 1 minute. The particle size distribution of particles with a diameter of 2 μm to 60 μm is then measured using a Coulter Multisizer II with a 100 μm aperture. The number of particles sampled is 50,000. Based on the measured particle size distribution, a cumulative distribution of volume and number is drawn for each divided particle size range (channel) from the smallest diameter side. The particle size at which the cumulative total reaches 16% is defined as the volume particle size D16v and the number particle size D16p, the particle size at which the cumulative total reaches 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size at which the cumulative total reaches 84% ​​is defined as the volume particle size D84v and the number particle size D84p. Using these, the volume particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 The GSDp index is (D84p / D16p) 1 / 2 It is calculated as follows.

[0076] The average circularity of the toner particles is preferably 0.94 to 1.00, and more preferably 0.95 to 0.98.

[0077] The average circularity of toner particles is determined by (circular equivalent perimeter) / (perimeter) [(perimeter of a circle with the same projected area as the particle image) / (perimeter of the particle projection image)]. Specifically, it is a value measured by the following method. First, the toner particles to be measured are collected by suction, a flattened flow is formed, and a still image of the particles is captured by instantaneous strobe flashing. This particle image is then analyzed using a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation). The number of samples used to determine the average circularity is 3500. If the toner contains external additives, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additives have been removed.

[0078] [External Additives] Examples of external additives include inorganic particles. These include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n Examples include Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, and MgSO4.

[0079] The surface of the inorganic particles used as an external additive should preferably be hydrophobic. Hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic agent. The hydrophobic agent is not particularly limited, but examples include silane-based coupling agents, silicone oil, titanate-based coupling agents, and aluminum-based coupling agents. These may be used individually or in combination of two or more. The amount of hydrophobic treatment agent is typically, for example, 1 to 10 parts by mass per 100 parts by mass of inorganic particles.

[0080] Examples of external additives include resin particles (such as polystyrene, polymethyl methacrylate, and melamine resin) and cleaning activators (for example, metal salts of higher fatty acids represented by zinc stearate, and fluorine-based high molecular weight particles).

[0081] The amount of external additive added is preferably 0.01% by mass or more and 5% by mass or less relative to the toner particles, and more preferably 0.01% by mass or more and 2.0% by mass or less.

[0082] [How to manufacture green toner] The green toner according to this embodiment is obtained by manufacturing green toner particles and then adding an external additive to the green toner particles.

[0083] Green toner particles may be manufactured by either a dry process (e.g., kneading and grinding) or a wet process (e.g., agglomeration, suspension polymerization, dissolution and suspension). There are no particular restrictions on these methods, and known methods can be used. Among these, obtaining toner particles by agglomeration is preferable.

[0084] When producing green toner particles by the aggregation and coalescence method, the following manufacturing method is preferred. The process involves preparing a resin particle dispersion in which resin particles that will serve as the binder are dispersed (resin particle dispersion preparation process); The process involves preparing a fluorescent pigment (Y) dispersion in which azomethine fluorescent pigment (Y) is dispersed (fluorescent pigment (Y) dispersion preparation process); The process involves preparing a pigment (G) dispersion in which pigment (G) is dispersed (pigment (G) dispersion preparation process); The process involves a step of forming aggregated particles (aggregated particle formation step) in a mixed dispersion obtained by mixing a resin particle dispersion, a fluorescent pigment (Y) dispersion, and a pigment (G) dispersion; A manufacturing method comprising the steps of: heating an aggregated particle dispersion containing dispersed aggregated particles to fuse and combine the aggregated particles to form green toner particles (fusion and combination step);

[0085] The details of each process are described below. In the following explanation, green toner particles will simply be referred to as toner particles. The following explanation describes a method for obtaining toner particles containing a release agent, but the release agent is used only as needed.

[0086] -Resin particle dispersion preparation process- A resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0087] Examples of dispersion media used in resin particle dispersions include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0088] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0089] In resin particle dispersions, common dispersion methods for dispersing resin particles in a dispersion medium include, for example, rotary shear homogenizers, ball mills with media, sand mills, and dyno mills. Depending on the type of resin particles, the resin particles may also be dispersed in the dispersion medium by phase inversion emulsification. Phase inversion emulsification is a method in which the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to neutralize the organic continuous phase (O phase), and then an aqueous medium (W phase) is added to perform a phase inversion from W / O to O / W, thereby dispersing the resin in particulate form in the aqueous medium.

[0090] The volume-average particle size of the resin particles dispersed in the resin particle dispersion is preferably 0.01 μm to 1 μm, more preferably 0.08 μm to 0.8 μm, and even more preferably 0.1 μm to 0.6 μm. The volume-average particle size of the resin particles is measured using a laser diffraction particle size distribution analyzer (e.g., LA-700 manufactured by Horiba, Ltd.). The cumulative distribution is subtracted from the smallest particle size side for each divided particle size range (channel), and the particle size that accounts for 50% of the total particle size is measured as the volume-average particle size D50v. The volume-average particle size of particles in other dispersions is measured in the same manner.

[0091] The resin particle content in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0092] The method for preparing the release agent particle dispersion is the same as for the resin particle dispersion. The release agent particle content in the release agent particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0093] -Preparation process for fluorescent pigment (Y) dispersion- A dispersion of fluorescent pigment (Y) is prepared, for example, by dispersing azomethine fluorescent pigment (Y) in a dispersion medium with a surfactant.

[0094] Examples of dispersion media used in a fluorescent pigment (Y) dispersion include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0095] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0096] Methods for dispersing azomethine fluorescent pigment (Y) in a dispersion medium include, for example, dispersion methods using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, a key mill, etc.

[0097] The volume-average particle size of the azomethine fluorescent pigment (Y) dispersed in the fluorescent pigment (Y) dispersion is preferably 50 nm to 800 nm, more preferably 150 nm to 600 nm, and even more preferably 250 nm to 400 nm. The particle size of the azomethine fluorescent pigment (Y) can be adjusted, for example, by the dispersion method and time.

[0098] The azomethine fluorescent pigment (Y) content 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.

[0099] - Preparation process for pigment (G) dispersion - A pigment (G) dispersion is prepared, for example, by dispersing pigment (G) in a dispersion medium with a surfactant.

[0100] Examples of dispersion media used in pigment (G) dispersions include aqueous media. Examples of aqueous media include water such as distilled water and deionized water, and alcohols. These may be used individually or in combination of two or more.

[0101] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly noteworthy. Nonionic surfactants may be used in combination with anionic or cationic surfactants. Surfactants may be used individually or in combination of two or more types.

[0102] Methods for dispersing the pigment (G) in a dispersion medium include, for example, dispersion methods using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, a key mill, etc.

[0103] The volume-average particle size of the pigment (G) dispersed in the pigment (G) dispersion is preferably 50 nm to 300 nm, more preferably 100 nm to 250 nm, and even more preferably 120 nm to 200 nm. The particle size of the pigment (G) can be adjusted, for example, by the dispersion method and time.

[0104] The pigment (G) content 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.

[0105] -Agglomerated particle formation process- A resin particle dispersion, a fluorescent pigment (Y) dispersion, a pigment (G) dispersion, and a release agent particle dispersion are mixed. Then, in the mixed dispersion, the resin particles, azomethine fluorescent pigment (Y), pigment (G), and release agent particles are heteroaggregated to form aggregated particles containing the resin particles, azomethine fluorescent pigment (Y), pigment (G), and release agent particles, which have a diameter close to that of the target toner particles.

[0106] Specifically, for example, a coagulant is added to a mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, pH 2 to 5), a dispersion stabilizer is added as needed, and then the mixture is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, above -30°C or below -10°C), causing the particles dispersed in the mixed dispersion to coagulate and form coagulated particles. In the agglomerated particle formation process, for example, the mixed dispersion may be stirred in a rotary shear homogenizer, a flocculant may be added at room temperature (e.g., 25°C), the pH of the mixed dispersion may be adjusted to acidic (e.g., pH 2 to 5), a dispersion stabilizer may be added as needed, and then heating may be performed.

[0107] Examples of flocculants include surfactants with opposite polarity to the surfactant contained in the mixed dispersion, inorganic metal salts, and metal complexes with a valency of 2 or higher. When a metal complex is used as a flocculant, the amount of surfactant used is reduced and the electrostatic properties are improved. Along with the flocculant, an additive that forms a complex or similar bond with the metal ions of the flocculant may be used as needed. A chelating agent is preferably used as this additive.

[0108] Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. As a chelating agent, a water-soluble chelating agent may be used. Examples of chelating agents include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; and aminocarboxylic acids such as iminodiacid acetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA). The amount of chelating agent added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of resin particles, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass.

[0109] -Fusion / unification process- Next, the dispersion of aggregated particles is heated to a temperature above the glass transition temperature of the resin particles (for example, 10°C to 30°C higher than the glass transition temperature of the resin particles) to fuse and combine the aggregated particles and form toner particles.

[0110] Toner particles are obtained through the above process. Toner particles may be manufactured by first obtaining an aggregate particle dispersion in which aggregate particles are dispersed, then further mixing the aggregate particle dispersion with a resin particle dispersion in which resin particles are dispersed, and agglomerating the aggregate particles so that the resin particles adhere to the surface of the aggregate particles to form second aggregate particles, and then heating the second aggregate particle dispersion in which the second aggregate particles are dispersed to fuse and combine the second aggregate particles to form toner particles with a core-shell structure.

[0111] After the fusion and combination process is completed, the toner particles in the dispersion are subjected to known washing, solid-liquid separation, and drying processes to obtain dried toner particles. From the viewpoint of electrostatic properties, the washing process should be performed thoroughly by displacement washing with ion-exchanged water. From the viewpoint of productivity, the solid-liquid separation process should be performed by suction filtration, pressure filtration, etc. From the viewpoint of productivity, the drying process should be performed by freeze-drying, air-flow drying, fluidized bed drying, vibratory fluidized bed drying, etc.

[0112] The toner according to this embodiment is manufactured, for example, by adding an external additive to the obtained dried toner particles and mixing them. Mixing is preferably carried out using a V-blender, Henschel mixer, Lödige mixer, etc. Furthermore, if necessary, coarse particles of the toner may be removed using a vibrating screen separator, a wind screen separator, etc.

[0113] <Electrostatic Image Developer> The electrostatic image developer according to this embodiment includes at least the green toner according to this embodiment. The electrostatic image developer according to this embodiment may be a one-component developer containing only the green toner according to this embodiment, or it may be a two-component developer in which the green toner and a carrier are mixed.

[0114] There are no particular restrictions on the carriers, and known carriers can be used. Examples of carriers include coated carriers in which a resin is coated on the surface of a core material made of magnetic powder; magnetic powder dispersed carriers in which magnetic powder is dispersed in a matrix resin; and resin-impregnated carriers in which resin is impregnated into porous magnetic powder. Magnetic powder dispersion carriers and resin-impregnated carriers may be carriers in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with resin.

[0115] Examples of magnetic powders include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0116] Examples of coating resins and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene acrylic acid ester copolymer, straight silicone resin or modified thereof containing organosiloxane bonds, fluororesin, polyester, polycarbonate, phenolic resin, epoxy resin, etc. The coating resin and matrix resin may also contain conductive particles and other additives. Examples of conductive particles include metals such as gold, silver, and copper, carbon black, titanium dioxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, etc.

[0117] To coat the surface of the core material with resin, one method is to coat it with a coating layer-forming solution prepared by dissolving the coating resin and various additives (used as needed) in a suitable solvent. The solvent is not particularly limited and should be selected considering the type of resin used and its suitability for coating. Specific resin coating methods include the immersion method, in which the core material is immersed in a coating layer forming solution; the spray method, in which the coating layer forming solution is sprayed onto the surface of the core material; the fluidized bed method, in which the coating layer forming solution is sprayed onto the core material while it is suspended by fluidized air; and the kneader coater method, in which the carrier core material and the coating layer forming solution are mixed in a kneader coater, and then the solvent is removed.

[0118] In a two-component developer, the mixing ratio (mass ratio) of green toner and carrier is preferably green toner:carrier = 1:100 to 30:100, and more preferably 3:100 to 20:100.

[0119] <Image forming device, image forming method> The image forming apparatus and image forming method according to this embodiment will be described below. The image forming apparatus according to this embodiment comprises an image holder, a charging means for charging the surface of the image holder, an electrostatic image forming means for forming an electrostatic image on the charged surface of the image holder, a developing means for containing an electrostatic image developer and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, a transfer means for transferring the toner image formed on the surface of the image holder to the surface of a recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic image developer according to this embodiment is applied as the electrostatic image developer.

[0120] The image forming apparatus according to this embodiment implements an image forming method (image forming method according to this embodiment) comprising: a charging step of charging the surface of an image holder; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image holder; a developing step of developing the electrostatic image formed on the surface of the image holder as a toner image using an electrostatic image developer according to this embodiment; a transfer step of transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0121] The image forming apparatus according to this embodiment may be any known image forming apparatus such as: a direct transfer apparatus that directly transfers a toner image formed on the surface of an image holder to a recording medium; an intermediate transfer apparatus that first transfers a toner image formed on the surface of an intermediate transfer body to the surface of an intermediate transfer body, and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; an apparatus equipped with cleaning means for cleaning the surface of the image holder before charging after the transfer of the toner image; or an apparatus equipped with static elimination means for irradiating the surface of the image holder with static elimination light before charging after the transfer of the toner image. In the case of an image forming apparatus of the present embodiment, if the image forming apparatus is an intermediate transfer type apparatus, the transfer means may include, for example, an intermediate transfer body on which a toner image is transferred; a primary transfer means for primaryly transferring the toner image formed on the surface of the image holder to the surface of the intermediate transfer body; and a secondary transfer means for secondary transferring the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

[0122] In the image forming apparatus according to this embodiment, for example, the part including the developing means may be a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge containing the electrostatic image developer according to this embodiment and equipped with a developing means is preferably used.

[0123] The following describes an example of an image forming apparatus according to this embodiment, but is not limited to this example. In the following description, only the main parts shown in the figures will be described, and other parts will be omitted.

[0124] In the following description, a six-unit tandem image forming apparatus, in which six image forming units are arranged in a row, will be described as an example of an image forming apparatus according to this embodiment. The tandem image forming apparatus is not limited to this, and may also be a five-unit tandem image forming apparatus, a four-unit tandem image forming apparatus, a four-unit tandem image forming apparatus, and so on.

[0125] Figure 1 is a schematic diagram showing an image forming apparatus according to this embodiment, and is a diagram showing an image forming apparatus with a 6-series tandem system and an intermediate transfer system. The image forming apparatus shown in Figure 1 includes first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, which are electrophotographic image forming means that output images of pink (P), yellow (Y), magenta (M), cyan (C), black (K), and green (G) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10P, 10Y, 10M, 10C, 10K, and 10G are arranged side by side at predetermined distances from each other in the horizontal direction. These units 10P, 10Y, 10M, 10C, 10K, and 10G may also be process cartridges that can be attached to and detached from the image forming apparatus.

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

[0127] Each of the developing devices (examples of developing means) for each unit 10P, 10Y, 10M, 10C, 10K, and 10G, specifically 4P, 4Y, 4M, 4C, 4K, and 4G, is supplied with pink, yellow, magenta, cyan, black, and green toners contained in toner cartridges 8P, 8Y, 8M, 8C, 8K, and 8G.

[0128] Since the first to sixth units 10P, 10Y, 10M, 10C, 10K, and 10G have equivalent configurations and operations, the sixth unit 10G, which forms the green image, will be described as representative here.

[0129] The sixth unit 10G has a photoreceptor 1G that acts as an image holder. Around the photoreceptor 1G are, in order, a charging roll (an example of a charging means) 2G that charges the surface of the photoreceptor 1G to a predetermined potential, an exposure device (an example of a charge image forming means) 3G that exposes the charged surface with a laser beam based on a color-separated image signal to form a charge image, a developing device (an example of a developing means) 4G that supplies toner to the charge image to develop the charge image, a primary transfer roll (an example of a primary transfer means) 5G that transfers the developed toner image onto an intermediate transfer belt 20, and a photoreceptor cleaning device (an example of a cleaning means) 6G that removes toner remaining on the surface of the photoreceptor 1G after primary transfer.

[0130] The primary transfer roll 5G is positioned inside the intermediate transfer belt 20, facing the photoreceptor 1G. Each primary transfer roll 5Y, 5P, 5M, 5C, 5G, and 5K of each unit is connected to a bias power supply (not shown) that applies the primary transfer bias. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll through control by a control unit (not shown).

[0131] The following describes the process of forming a green image in the 6th unit 10G. First, prior to operation, the surface of the photoreceptor 1G is charged to a potential of -600V to -800V by the charging roll 2G. Photoreceptor 1G is conductive (e.g., volume resistivity of 1 × 10 at 20°C). -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate (less than Ωcm). This photosensitive layer normally has high resistance (resistance of general resin), but when irradiated with a laser beam, the resistivity of the irradiated area changes. Therefore, a laser beam is irradiated from the exposure device 3G onto the surface of the charged photoreceptor 1G according to green image data sent from a control unit (not shown). As a result, an electrostatic image of the green image pattern is formed on the surface of the photoreceptor 1G.

[0132] An electrostatic image is an image formed on the surface of the photoreceptor 1G due to electrostatic charge. It is a so-called negative latent image formed when the resistivity of the irradiated portion of the photoreceptor decreases due to the laser beam from the exposure device 3G, causing the charged material on the surface of the photoreceptor 1G to flow, while the charge remains in the portion not irradiated by the laser beam. The electrostatic charge image formed on the photoreceptor 1G rotates to a predetermined development position as the photoreceptor 1G moves. At this development position, the electrostatic charge image on the photoreceptor 1G is developed as a toner image by the developing device 4G and made visible.

[0133] The developing unit 4G contains, for example, an electrostatic image developer including at least green toner and a carrier. The green toner is triboelectrically charged by being agitated inside the developing unit 4G and is held on the developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the static charge on the photoreceptor 1G. As the surface of the photoreceptor 1G passes through the developing unit 4G, the green toner electrostatically adheres to the discharged latent image on the surface of the photoreceptor 1G, and the latent image is developed by the green toner. The photoreceptor 1G, on which the green toner image has been formed, continues to move at a predetermined speed, and the toner image developed on the photoreceptor 1G is transported to a predetermined primary transfer position.

[0134] When the green toner image on the photoreceptor 1G is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5G, and an electrostatic force acts on the toner image from the photoreceptor 1G to the primary transfer roll 5G, transferring the toner image on the photoreceptor 1G onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity opposite to the toner's polarity (-) (+), and in the first unit 10G, it is controlled by a control unit (not shown) to, for example, +10 μA.

[0135] After transferring the toner image to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with the cleaning blades of the photoreceptor cleaning device 6G. Any toner remaining on the photoreceptor 1G is removed and collected by the photoreceptor cleaning device 6G.

[0136] The intermediate transfer belt 20 is sequentially transported through the first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, and the toner images of each color are superimposed and transferred in multiple layers.

[0137] The intermediate transfer belt 20, on which six toner images have been multiple-transferred through the first to sixth units, proceeds to a secondary transfer section consisting of the intermediate transfer belt 20, a counter roll 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer means) 26 positioned on the image-holding surface side of the intermediate transfer belt 20. Meanwhile, recording paper (an example of a recording medium) P is fed via a supply mechanism into the gap between the secondary transfer roll 26 and the intermediate transfer belt 20 at a predetermined timing, and a secondary transfer bias is applied to the counter roll 24. The transfer bias applied at this time has the same polarity (-) as the toner's polarity (-), and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, transferring the toner image on the intermediate transfer belt 20 onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) that detects the resistance of the secondary transfer section, and is voltage-controlled.

[0138] After transferring the toner image to the recording paper P, the intermediate transfer belt 20 continues to move and comes into contact with the cleaning blades of the intermediate transfer body cleaning device 21. Any toner remaining on the intermediate transfer belt 20 is removed and collected by the intermediate transfer body cleaning device 21.

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

[0140] Examples of recording paper P used to transfer toner images include plain paper used in electrophotographic photocopiers and printers. Other recording media besides recording paper P include OHP sheets. To further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper, which is plain paper coated with resin or the like, or art paper for printing are preferably used.

[0141] Once the color image has been fixed onto the recording paper P, it is discharged towards the output section, and the series of color image formation operations is completed.

[0142] <Processor cartridges, toner cartridges> The process cartridge according to this embodiment will be described. The process cartridge according to this embodiment contains the electrostatic image developer according to this embodiment and includes a developing means for developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, and is a process cartridge that can be attached to and detached from an image forming apparatus.

[0143] The process cartridge according to this embodiment is not limited to the above configuration, and may also include a developing means and, as necessary, at least one other means selected from, for example, an image holder, a charging means, an electrostatic image forming means, and a transfer means.

[0144] The following shows an example of a process cartridge according to this embodiment, but it is not limited to this example. In the following description, only the main parts shown in the figure will be described, and other parts will be omitted from the description.

[0145] Figure 2 is a schematic diagram showing the process cartridge according to this embodiment. The process cartridge 200 shown in Figure 2 is constructed by integrally holding a photoreceptor 107 (an example of an image holder), a charging roll 108 (an example of a charging means) provided around the photoreceptor 107, a developing device 111 (an example of a developing means), and a photoreceptor cleaning device 113 (an example of a cleaning means) within a housing 117 equipped with a mounting rail 116 and an opening 118 for exposure, and is then formed into a cartridge. In Figure 2, 109 is an exposure apparatus (an example of electrostatic image formation means), 112 is a transfer apparatus (an example of a transfer means), 115 is a fixing apparatus (an example of a fixing means), and 300 is recording paper (an example of a recording medium).

[0146] Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to this embodiment is a toner cartridge that contains the green toner according to this embodiment and is attached to and detached from an image forming apparatus. The toner cartridge contains replenishment toner for supply to the developing means provided in the image forming apparatus.

[0147] The image forming apparatus shown in Figure 1 is configured to allow the attachment and detachment of toner cartridges 8Y, 8P, 8M, 8C, 8G, and 8K. The developing units 4Y, 4P, 4M, 4C, 4G, and 4K are connected to toner cartridges corresponding to their respective colors by toner supply pipes (not shown). When the toner contained in a toner cartridge becomes low, the toner cartridge is replaced. An example of a toner cartridge according to this embodiment is toner cartridge 8G, which contains the green toner according to this embodiment. Toner cartridges 8P, 8Y, 8M, 8C, and 8K contain pink, yellow, magenta, cyan, and black toners, respectively. [Examples]

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

[0149] <Career> • Cyclohexyl methacrylate resin (weight-average molecular weight 50,000): 54 parts • Carbon black (Cabot, VXC72): 6 parts • Toluene: 250 copies • Isopropyl alcohol: 50 units The above materials and glass beads (1 mm in diameter, in the same amount as toluene) were placed in a sand mill and stirred at a rotation speed of 190 rpm for 30 minutes to obtain a coating agent.

[0150] 1000 parts of ferrite particles (volume average particle size 35 μm) and 150 parts of coating agent were placed in 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 material was cooled to room temperature (25°C), removed from the kneader, and sieved through a 75 μm mesh to remove coarse powder and obtain a carrier.

[0151] <Cyan toner and cyan developer> [Preparation of resin particle dispersion (1)] • Ethylene glycol: 37 parts • Neopentyl glycol: 65 parts • 1,9-nonanediol: 32 parts Terephthalic acid: 96 parts The above materials were placed in a flask, and the temperature was raised to 200°C over 1 hour. After confirming that the reaction system was uniformly stirred, 1.2 parts of dibutyltin oxide were added. The temperature was raised to 240°C over 6 hours while distilling off the generated water, and stirring was continued at 240°C for 4 hours to obtain amorphous polyester resin (weight-average molecular weight 13,000, glass transition temperature 62°C). The amorphous polyester resin, in its molten state, was transferred to an emulsifier / disperser (Cavitron CD1010, Eurotech) at a rate of 100g per minute. Separately, a 0.37% dilute ammonia solution, obtained by diluting reagent ammonia solution with ion-exchanged water, was placed in a tank and transferred to the emulsifier / disperser simultaneously with the polyester resin at a rate of 0.1 liters per minute while being heated to 120°C in a heat exchanger. The emulsifier / disperser was operated at a rotor speed of 60Hz and a pressure of 5kg / cm². 2 The system was operated under the specified conditions to obtain a resin particle dispersion (1) with a volume-average particle size of 160 nm and a solid content of 20%.

[0152] [Preparation of mold release agent particle dispersion (W)] • Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 50 units • Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): Part 2 • Ion-exchanged water: 200 bottles The above materials were heated to 120°C, thoroughly dispersed in a homogenizer (Ultra-Turrax T50, IKA), and then dispersed again in a pressure-discharge homogenizer. When the volume-average particle size reached 200 nm, the mixture was collected to obtain a release agent particle dispersion (W) with a solid content of 20%.

[0153] [Preparation of colorant particle dispersion (C)] • Cyan pigment (CI Pigment Blue 15:3, Dainichi Seika Kogyo Co., Ltd.): 50 units • Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): Part 2 • Ion-exchanged water: 200 bottles The above materials were mixed and dispersed for 1 hour using a high-pressure impact disperser (Ultimizer HJP30006, Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion (C) with a volume-average particle size of 180 nm and a solid content of 20%.

[0154] [Production of Cyantoner Particles] ·Resin particle dispersion (1): 200 parts • Release agent particle dispersion (W): 35 parts • Coloring agent particle dispersion (C): 25 parts • Polyaluminum chloride: 0.4 parts • Ion-exchanged water: 100 bottles The above materials were placed in a round stainless steel flask and thoroughly mixed and dispersed using a homogenizer (Ultra-Turrax T50, IKA). The flask was then heated to 48°C in a heating oil bath while stirring. After maintaining the reaction system at 48°C for 60 minutes, 70 parts of resin particle dispersion (1) were slowly added. Next, the pH was adjusted to 8.0 using a 0.5 mol / L sodium hydroxide aqueous solution. The flask was then sealed, the stirring shaft seal was magnetically sealed, and the mixture was heated to 90°C and maintained for 30 minutes while continuing to stir. Next, the mixture was cooled at a rate of 5°C / min, solid-liquid separation was performed, and the mixture was thoroughly washed with deionized water. Then, solid-liquid separation was performed again, the mixture was redispersed in deionized water at 30°C, and washed by stirring at a rotation speed of 300 rpm for 15 minutes. This washing operation was repeated six more times, and solid-liquid separation was performed when the pH of the filtrate reached 7.54 and the electrical conductivity reached 6.5 μS / cm. The solid components were vacuum-dried for 24 hours to obtain cyan toner particles. The volume-average particle size of the cyan toner particles was 5.7 μm.

[0155] [Preparation of cyan toner and cyan developer] 1.5 parts hydrophobic silica particles (RY50, manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts cyan toner particles and mixed for 30 seconds at 13,000 rpm using a sample mill. The mixture was then sieved using a vibrating sieve with a mesh size of 45 μm to obtain the external toner. Ten parts of external toner and 100 parts of carrier were placed in a V-blender and stirred for 20 minutes. Then, the mixture was sieved through a 212 μm mesh sieve to obtain the cyanide developer.

[0156] <Yellow toner and yellow developer> Except for changing the cyan pigment (CI Pigment Blue 15:3, Dainichi Seika Kogyo Co., Ltd.) to a yellow pigment (CI Pigment Yellow 74, Dainichi Seika Kogyo Co., Ltd.), the yellow toner and yellow developer were manufactured using the same process as the cyan toner and cyan developer.

[0157] <Example 1: Green toner and green developer> [Preparation of resin particle dispersion (1)] • Ethylene glycol: 37 parts • Neopentyl glycol: 65 parts • 1,9-nonanediol: 32 parts Terephthalic acid: 96 parts The above materials were placed in a flask, and the temperature was raised to 200°C over 1 hour. After confirming that the reaction system was uniformly stirred, 1.2 parts of dibutyltin oxide were added. The temperature was raised to 240°C over 6 hours while distilling off the generated water, and stirring was continued at 240°C for 4 hours to obtain amorphous polyester resin (weight-average molecular weight 13,000, glass transition temperature 62°C). The amorphous polyester resin, in its molten state, was transferred to an emulsifier / disperser (Cavitron CD1010, Eurotech) at a rate of 100g per minute. Separately, a 0.37% dilute ammonia solution, obtained by diluting reagent ammonia solution with ion-exchanged water, was placed in a tank and transferred to the emulsifier / disperser simultaneously with the polyester resin at a rate of 0.1 liters per minute while being heated to 120°C in a heat exchanger. The emulsifier / disperser was operated at a rotor speed of 60Hz and a pressure of 5kg / cm². 2 The system was operated under the specified conditions to obtain a resin particle dispersion (1) with a volume-average particle size of 160 nm and a solid content of 20%.

[0158] [Preparation of mold release agent particle dispersion (W)] • Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 50 units • Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): Part 2 • Ion-exchanged water: 200 bottles The above materials were heated to 120°C, thoroughly dispersed in a homogenizer (Ultra-Turrax T50, IKA), and then dispersed again in a pressure-discharge homogenizer. When the volume-average particle size reached 200 nm, the mixture was collected to obtain a release agent particle dispersion (W) with a solid content of 20%.

[0159] [Preparation of Pigment Dispersion (Y101)] CI Pigment Yellow 101: 70 copies • Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts (20% solids) • Ion-exchanged water: 200 bottles The above materials were mixed and ground to a volume-average particle size of 300 nm using a continuous key mill (KMC-3, Inoue Seisakusho Co., Ltd.). The solid content was adjusted to 20% to obtain a pigment dispersion (Y101).

[0160] [Preparation of Pigment Dispersion (PG36)] CI Pigment Green 36: 70 copies • Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts (20% solids) • Ion-exchanged water: 200 bottles The above materials were mixed and ground to a volume-average particle size of 150 nm using a continuous key mill (KMC-3, Inoue Seisakusho Co., Ltd.). The solid content was adjusted to 20% to obtain a pigment dispersion (PG36).

[0161] [Production of Green Toner Particles] ·Resin particle dispersion (1) (solid content 20%): 182.5 parts • Release agent particle dispersion (W) (20% solids): 35 parts • Pigment dispersion (Y101) (20% solids): 28.3 parts • Pigment dispersion (PG36) (20% solids): 14.2 parts • Polyaluminum chloride: 0.4 parts • Ion-exchanged water: 100 bottles The above materials were placed in a round stainless steel flask and thoroughly mixed and dispersed using a homogenizer (Ultra-Turrax T50, IKA). The flask was then heated to 48°C in a heating oil bath while stirring. After maintaining the reaction system at 48°C for 60 minutes, 70 parts of resin particle dispersion (1) (20% solid content) were slowly added. Next, the pH was adjusted to 8.0 using a 0.5 mol / L sodium hydroxide aqueous solution. The flask was then sealed, the stirring shaft seal was magnetically sealed, and the mixture was heated to 90°C and maintained for 30 minutes while continuing to stir. Next, the mixture was cooled at a rate of 5°C / min, solid-liquid separation was performed, and the mixture was thoroughly washed with deionized water. Then, solid-liquid separation was performed again, the mixture was redispersed in deionized water at 30°C, and washed by stirring at a rotation speed of 300 rpm for 15 minutes. This washing operation was repeated six more times, and solid-liquid separation was performed when the pH of the filtrate reached 7.54 and the electrical conductivity reached 6.5 μS / cm. The solid components were vacuum-dried for 24 hours to obtain green toner particles. The volume-average particle size of the green toner particles was 5.6 μm.

[0162] [Preparation of green toner and green developer] 1.5 parts of hydrophobic silica particles (RY50, manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts of green toner particles and mixed for 30 seconds at 13,000 rpm using a sample mill. The mixture was then sieved using a vibrating sieve with a mesh size of 45 μm to obtain the external toner. Ten parts of external toner and 100 parts of carrier were placed in a V-blender and stirred for 20 minutes. Then, the mixture was sieved through a 212 μm mesh sieve to obtain the green developer.

[0163] <Examples 2-20, Comparative Examples 6-10> Green toner particles, green toner, and green developer were produced by the same process as in Example 1, except that the type of non-fluorescent pigment, pigment content, and particle size were changed to the forms shown in Tables 1 and 2. The particle size of the pigment was controlled by the processing time of the continuous key mill when preparing the pigment dispersion.

[0164] <Comparative Example 1> [Preparation of a dispersion of dye-containing resin particles] CI Solvent Green 5:2 parts · Amorphous polyester resin (weight average molecular weight 13,000, glass transition temperature 62°C) : 100 parts The above materials were heated and mixed, and a dye was kneaded into the resin. The kneaded product was rolled and cooled to 30°C or lower. The obtained kneaded product was coarsely pulverized to 1 mm or less with a hammer mill and finely pulverized with a jet mill (AFG, Hosokawa Micron Corporation). The particles obtained by fine pulverization were mixed with 30 parts (solid content 20%) of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts of ion-exchanged water, and pulverized to a volume average particle diameter of 200 nm with a continuous kneader mill (KMC-3, Inoue Manufacturing Co., Ltd.). It was adjusted to a solid content of 20% to obtain a dye-containing resin particle dispersion (SG5).

[0165] [Production of green toner particles] By the same treatment as in Example 1, except that the pigment dispersion (Y101) was changed to a dye-containing resin particle dispersion (SG5) and the amount of the resin particle dispersion (1) used was adjusted, green toner particles were obtained. The volume average particle diameter of the green toner particles was 5.6 μm.

[0166] [Production of green toner and green developer] 1.5 parts of hydrophobic silica particles (RY50 manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts of green toner particles, and they were mixed at 13,000 rpm for 30 seconds using a sample mill. Then, they were sieved with a vibrating sieve having a mesh opening of 45 μm to obtain an 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, they were sieved with a sieve having a mesh opening of 212 μm to obtain a green developer.

[0167] <Comparative Examples 2 to 5> By the same treatment as in Comparative Example 1, except that the type of non-fluorescent pigment and the content of the pigment were changed to the forms described in Table 1, green toner particles, green toner, and green developer were produced.

[0168] <Example 21> Green toner particles, green toner, and green developer were produced by the same process as in Example 1, except that the 182.5 parts of resin particle dispersion (1) initially used were replaced with 91.3 parts of resin particle dispersion (1) and 91.3 parts of resin particle dispersion (2). The resin particle dispersion (2) is the following resin particle dispersion, which is a dispersion of amorphous polyester resin.

[0169] [Resin particle dispersion (2)] • Ethylene glycol: 41 parts • 1,5-Pentanediol: 48 parts Terephthalic acid: 70 parts • Fumaric acid: 30 parts The above materials were placed in a reaction vessel equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectification column. Under a nitrogen gas stream, the temperature was raised to 220°C over 1 hour, and 1 part titanium tetraethoxide was added for every 100 parts of the above materials. The temperature was raised to 240°C over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at 240°C for 1 hour. After that, the reactants were cooled to obtain amorphous polyester resin (weight-average molecular weight 96,000, glass transition temperature 61°C). In a tank equipped with temperature control and nitrogen purging means, 40 parts ethyl acetate and 25 parts 2-butanol were added to make a mixed solvent, and 100 parts amorphous polyester resin was gradually added and dissolved. A 10% aqueous ammonia solution (equivalent to 3 times the molar ratio to the acid value of the resin) was added and stirred for 30 minutes. Next, the reaction vessel was purged with dry nitrogen, and the temperature was maintained at 40°C. While stirring the mixture, 400 parts of deionized water were added dropwise at a rate of 2 parts / minute to carry out emulsification. After the dropwise addition was complete, the emulsion was returned to 25°C, and the solvent was removed under reduced pressure to obtain a resin particle dispersion in which resin particles with a volume-average particle size of 160 nm were dispersed. Deionized water was added to this resin particle dispersion to adjust the solid content to 20% to obtain resin particle dispersion (2).

[0170] <Example 22> Green toner particles, green toner, and green developer were produced by the same process as in Example 1, except that the 182.5 parts of resin particle dispersion (1) initially used were replaced with 152.5 parts of resin particle dispersion (1) and 30 parts of resin particle dispersion (3). The resin particle dispersion (3) is the following resin particle dispersion, which is a dispersion of crystalline polyester resin.

[0171] [Preparation of resin particle dispersion (3)] Decandioic acid: 81 parts Hexanediol: 47 parts The above materials were placed in a flask, and the temperature was raised to 160°C over 1 hour. After confirming that the reaction system was uniformly stirred, 0.03 parts of dibutyltin oxide were added. The temperature was raised to 200°C over 6 hours while distilling off the water produced, and stirring was continued at 200°C for 4 hours. Next, the reaction mixture was cooled, solid-liquid separation was performed, and the solid was dried at 40°C under reduced pressure to obtain a crystalline polyester resin (weight-average molecular weight 15,000, melting point 64°C).

[0172] • Crystalline polyester resin: 50 parts • Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): Part 2 • Ion-exchanged water: 200 bottles The above materials were heated to 120°C and thoroughly dispersed in a homogenizer (Ultra-Turrax T50, IKA Corporation), and then dispersed again in a pressure-discharge homogenizer. When the volume-average particle size reached 180 nm, the mixture was collected to obtain a resin particle dispersion (3) with a solid content of 20%.

[0173] <Example 23> [Production of Green Toner Particles] Amorphous polyester resin (weight-average molecular weight 13,000, glass transition temperature 62°C): 155.4 parts CI Pigment Yellow 101: 16 units CI Pigment Green 36: 8 parts Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 20.6 parts The above materials were put into a Henschel mixer (FM75L, Nippon Coke & Engineering Co., Ltd.) and rotated and mixed for 15 minutes at a rotation speed of 20 rotations per second to obtain a toner composition. Then, it was kneaded with a twin-screw kneading extruder (TEM-48SS, Shibaura Machine Co., Ltd.) set at a temperature of 150°C, the kneaded product was rolled, and cooled to 30°C or lower. The obtained kneaded product was coarsely pulverized to 1 mm or less with a hammer mill and finely pulverized with a jet mill (AFG, Hosokawa Micron Corporation). Classification was performed with an elbow jet classifier (EJ-LABO, Nippon Steel Mining Co., Ltd.) to obtain green toner particles with a volume average particle diameter of 6.5 μm.

[0174] [Preparation of Green Toner and Green Developer] 1.5 parts of hydrophobic silica particles (RY50 manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts of green toner particles and mixed at 13,000 rpm for 30 seconds using a sample mill. Then, it was sieved with a vibrating sieve having a mesh size of 45 μm to obtain an 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 having a mesh size of 212 μm to obtain a green developer.

[0175] [Performance Evaluation] [Image Formation] As an image forming apparatus for forming an evaluation image, a modified ColorPress1000 (Fuji Film Innovation Co., Ltd.) was prepared, the developer was put into the developing device, and the toner was put into the toner cartridge. A4 size coated paper (OS coated paper, 127 g / m 2 , Fuji Film Innovation Co., Ltd.) was used to form a solid green image (concentration 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ). The fixing temperature was set at 180°C. In Reference Example 1 where green was expressed as a secondary color using yellow toner and cyan toner, the yellow toner loading was 4.0 g / m 2 and the cyan toner loading was 4.0 g / m 2 . The fixing temperature was set at 180°C.

[0176] [Brightness, Chroma, Hue Angle] Using a reflection spectrophotometer X-Rite 939 (aperture diameter 4 mm, X-Rite Co., Ltd.), at 10 locations in the solid image, CIE 1976 L * a * b * value in the color system, L * value, a * value and b * value were measured, and the average values of the L * value, a * value and b * value were calculated. Furthermore, chroma C * and hue angle h were calculated from the following formula. The results are shown in Table 1 and Table 2. Brightness L * is preferably 70 or more, and chroma C * is preferably 85 or more. Chroma C * ={ (a * ) 2 +(b * ) 2} 0.5 Hue angle h = tan -1 (b * / a * )

[0177] [Color Difference from Color Sample] Based on the following formula, the color difference ΔE between the solid image and the color sample TOKA FLASH VIVA DX 650 (T&K TOKA Co., Ltd.) was calculated. The results are shown in Table 1 and Table 2.

[0178]

Equation

[0179] [Table 1]

[0180] [Table 2]

[0181] The symbols in Tables 1 and 2 represent the following pigments or dyes. ·SG5 ···CI Solvent Green 5 (BASF, Oracet F Yellow 084, emission peak 520nm), a type of yellow fluorescent dye. • PY101 ···CI Pigment Yellow 101 (Radiant Color, Radglo VSF-0-01, emission peak 520nm), a type of azomethine fluorescent pigment (Y) • PG36 ···CI Pigment Green 36 (manufactured by Toyo Color Co., Ltd., LIONOL GREEN 8624, reflectance peak 510nm), type (G) • PG59 ···CI Pigment Green 59 (DIC Corporation, FASTOGEN GREEN C100, reflectance peak 520nm), one type of pigment (G) • PG58 ···CI Pigment Green 58 (DIC Corporation, FASTOGEN GREEN A110, reflectance peak 515nm), one type of pigment (G) • PG7 ···CI Pigment Green 7 (manufactured by Toyo Color Co., Ltd., LIONOL GREEN 8390, reflectance peak 500nm), one type of pigment (G) ·PB76 ···CI Pigment Blue 76 (DIC Corporation, FASTOGEN BLUE 10GN, reflectance peak 490nm), one type of pigment (G) PB15:3···CI Pigment Blue 15:3 (manufactured by Toyo Color Co., Ltd., LIONOL BLUE FG-7330, reflectance peak 470nm), a type of non-fluorescent pigment.

[0182] <Image formation using actual equipment> A six-tandem electrophotographic and intermediate transfer image forming apparatus was prepared. Each of the six developing units was filled with a pink developer, a yellow developer, a magenta developer, a cyan developer, a black developer, and a green developer (the developer from Example 1). Then, based on the image data obtained by color-separating RGB data into the six colors described above, an image was formed on A4-sized coated paper. An image with good color reproduction close to the original RGB data was obtained.

[0183] (((1))) Binding resin and an azomethine fluorescent pigment having an emission peak in the emission spectrum wavelength region of 500 nm to 550 nm, A non-fluorescent pigment having a reflectance peak in the region of the reflectance spectrum between 480 nm and 540 nm wavelengths, The mass-based ratio M2 / M1 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 0.05 or more and 1.5 or less. The total content of the azomethine fluorescent pigment and the non-fluorescent pigment relative to the total green toner particles is 5% by mass or more and 15% by mass or less. Green toner particles, Includes a green toner for electrostatic image development. (((2))) The mass-based ratio M2 / M1 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 0.1 or more and 1.0 or less. The total content of the azomethine fluorescent pigment and the non-fluorescent pigment relative to the entire green toner particles is 10% by mass or more and 15% by mass or less. The green toner for developing electrostatic images as described in (((1))). (((3))) The wavelength difference between the emission peak of the azomethine fluorescent pigment with the highest content among the azomethine fluorescent pigments contained in the green toner particles and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 40 nm or less. The green toner for developing electrostatic images as described in (((1))) or (((2))). (((4))) The wavelength difference between the emission peak of the azomethine fluorescent pigment with the highest content among the azomethine fluorescent pigments contained in the green toner particles and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 20 nm or less. The green toner for developing electrostatic images as described in (((1))) or (((2))). (((5))) The azomethine fluorescent pigment is CI Pigment Yellow 101. A green toner for developing electrostatic images as described in any one of the items (((1))) to (((4))). (((6))) The non-fluorescent pigment is at least one selected from the group consisting of CI pigment green 7, CI pigment green 36, CI pigment green 58, CI pigment green 59, and CI pigment blue 76. A green toner for developing electrostatic images as described in any one of the items (((1))) to (((5))). (((7))) The ratio D1 / D2 of the volume average particle size D1 of the azomethine fluorescent pigment to the volume average particle size D2 of the non-fluorescent pigment is 1 or more and 3 or less. A green toner for developing electrostatic images as described in any one of the items (((1))) to (((6))). (((8))) The volume-average particle size D1 of the azomethine fluorescent pigment is 50 nm or more and 800 nm or less. A green toner for developing electrostatic images as described in any one of the items (((1))) to (((7))). (((9))) The volume-average particle size D2 of the non-fluorescent pigment is 50 nm or more and 300 nm. A green toner for developing electrostatic images as described in any one of the items (((1))) to (((8))). (((10))) The green toner particles include a binder resin, an azomethine fluorescent pigment having an emission peak in the wavelength region of 500 nm to 550 nm in the emission spectrum, and a non-fluorescent pigment having a reflectance peak in the wavelength region of 480 nm to 540 nm in the reflectance spectrum. When a solid image is formed on coated paper, the color sample TOKA FLASH VIVA DX 650 and CIE1976L * a * b * The color difference ΔE in the color system is 13.5 or less. Green toner for developing electrostatic images. (((11))) The azomethine fluorescent pigment is CI Pigment Yellow 101. The green toner for developing electrostatic images as described in (((10))). (((12))) The non-fluorescent pigment is at least one selected from the group consisting of CI pigment green 7, CI pigment green 36, CI pigment green 58, CI pigment green 59, and CI pigment blue 76. The green toner for developing electrostatic images as described in (((10))) or (((11))).

[0184] (((13))) A charge image developer containing a green toner for developing charge images as described in any one of items (((1))) to (((12))). (((14))) A toner cartridge that contains the electrostatic image developing green toner described in any one of items (((1))) to (((12))) and is attached to and detached from an image forming apparatus. (((15))) The developing means contains the electrostatic image developer described in (((13))) and develops the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, A process cartridge that is attached to and detached from an image forming apparatus. (((16))) Image holder and, A charging means for charging the surface of the image holder, A means for forming an electrostatic image on the surface of the charged image holder, A developing means containing the electrostatic image developer described in (((13))) and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer, A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus equipped with the following features. (((17))) A charging step in which the surface of the image holder is charged, A step of forming an electrostatic image on the surface of the charged image holder, A developing step in which the electrostatic image formed on the surface of the image holder is developed as a toner image using the electrostatic image developer described in (((13))), A transfer step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium, A fixing step for fixing the toner image transferred to the surface of the recording medium, An image forming method having the following characteristics. (((18))) It comprises first to sixth image forming units of an electrophotographic method that form images of pink, yellow, magenta, cyan, black, and green, The image forming unit that forms the green image contains the electrostatic image developer described in (((13))), Image forming apparatus. (((19))) The system has first to sixth image forming steps using an electrophotographic method to form images of pink, yellow, magenta, cyan, black, and green. The image forming step for forming the aforementioned green image uses the electrostatic image developer described in (((13))) Image forming method.

[0185] According to the inventions of (((1))), (((2))), (((5))), (((6))), (((8))), or (((9))), a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((3))), a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the wavelength difference between the emission peak and the reflection peak is greater than 40 nm. According to the invention of (((4))), a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the wavelength difference between the emission peak and the reflection peak is greater than 20 nm. According to the invention of (((7))), a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to cases where the ratio D1 / D2 of the volume average particle size D1 of the azomethine fluorescent pigment to the volume average particle size D2 of the non-fluorescent pigment is less than 1 or greater than 3. According to the inventions of (((10))), (((11))), or (((12))), a green toner for electrostatic image development is provided that can form a green image with higher brightness and saturation compared to the case where the color difference ΔE with the color sample TOKA FLASH VIVA DX 650 is greater than 10.

[0186] According to the invention of (((13))), an electrostatic image developer is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((14))), a toner cartridge is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((15))), a process cartridge is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((16))), an image forming apparatus is provided that can form a green image with higher brightness and saturation compared to when the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((17))), an image forming method is provided that can form a green image with higher brightness and saturation compared to the case where the yellow fluorescent colorant is CI Solvent Green 5. According to the invention of (((18))), an image forming apparatus is provided that can reproduce a wide color gamut. According to the invention of (((19))), an image forming method is provided that has a wide color gamut that can be reproduced. [Explanation of Symbols]

[0187] 1P, 1Y, 1M, 1C, 1K, 1G Photoreceptor (an example of an image retainer) 2P, 2Y, 2M, 2C, 2K, 2G Charging Rolls (Example of Charging Method) 3P, 3Y, 3M, 3C, 3K, 3G exposure equipment (an example of electrostatic image forming means) 4P, 4Y, 4M, 4C, 4K, 4G developing device (an example of a developing method) 5P, 5Y, 5M, 5C, 5K, 5G Primary transfer rolls (an example of a primary transfer method) 6P, 6Y, 6M, 6C, 6K, 6G Photoconductor Cleaning Device (Example of Cleaning Method) 8P, 8Y, 8M, 8C, 8K, 8G Toner Cartridges 10P, 10Y, 10M, 10C, 10K, 10G Image Forming Units 20. Intermediate transfer belt (an example of an intermediate transfer material) 21 Intermediate Transfer Body Cleaning Apparatus 22 Drive Roll 23 Support Roll 24 Opposing Roll 26. Secondary transfer roll (an example of a secondary transfer means) 28 Fixing device (an example of a fixing means) P Recording paper (an example of a recording medium)

[0188] 107 Photoreceptor (an example of an image-retaining element) 108 Charging Roll (Example of Charging Method) 109 Exposure apparatus (an example of a means for forming electrostatic images) 111 Developing apparatus (an example of a developing means) 112 Transfer device (an example of a transfer means) 113 Photoreceptor cleaning device (an example of a cleaning method) 115 Fixing device (an example of a fixing means) 116 Mounting Rail 117 cabinets 118 Aperture for exposure 200 Process Cartridges 300 Recording paper (an example of a recording medium)

Claims

1. Binding resin and C.I. Pigment Yellow 101 and, It comprises at least one non-fluorescent pigment 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 mass-based ratio M2 / M1 of the content M1 of C.I. Pigment Yellow 101 to the content M2 of the non-fluorescent pigment is 0.05 or more and 1.5 or less. The total content of the C.I. Pigment Yellow 101 and the non-fluorescent pigment relative to the total green toner particles is 5% by mass or more and 15% by mass or less. Green toner particles.

2. The mass-based ratio M2 / M1 of the content M1 of C.I. Pigment Yellow 101 to the content M2 of the non-fluorescent pigment is 0.1 or more and 1.0 or less. The total content of the C.I. Pigment Yellow 101 and the non-fluorescent pigment relative to the total amount of the green toner particles is 10% by mass or more and 15% by mass or less. Green toner particles as described in claim 1.

3. The wavelength difference between the emission peak of the C.I. Pigment Yellow 101 and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 40 nm or less. Green toner particles as described in claim 1.

4. The wavelength difference between the emission peak of the C.I. Pigment Yellow 101 and the reflection peak of the non-fluorescent pigment with the highest content among the non-fluorescent pigments contained in the green toner particles is 20 nm or less. Green toner particles as described in claim 1.

5. The ratio D1 / D2 of the volume-average particle size D1 of the C.I. pigment yellow 101 to the volume-average particle size D2 of the non-fluorescent pigment is 1 or more and 3 or less. Green toner particles as described in claim 1.

6. The volume-average particle size D1 of the aforementioned C.I. Pigment Yellow 101 is 50 nm or more and 800 nm or less. Green toner particles as described in claim 1.

7. The volume-average particle size D2 of the non-fluorescent pigment is 50 nm or more and 300 nm. Green toner particles as described in claim 1.

8. Green toner particles according to any one of claims 1 to 7, The green toner particles include an external additive, Green toner for developing electrostatic images.

9. Green toner particles according to any one of claims 1 to 7, The green toner particles contain an external additive, When a solid image is formed on coated paper, the color sample TOKA FLASH VIVA DX 650 is compared to CIE1976L ＊ a ＊ b ＊ The color difference ΔE in the color system is 13.5 or less. Green toner for developing electrostatic images.

10. A electrostatic image developer comprising the green toner for electrostatic image development described in claim 8.

11. A toner cartridge containing the electrostatic image developing green toner described in claim 8, which is attached to and detached from an image forming apparatus.

12. The development means comprises a static charge image developer according to claim 10, and develops a static charge image formed on the surface of an image holder as a toner image using the static charge image developer, A process cartridge that is attached to and detached from an image forming apparatus.

13. Image holder and, A charging means for charging the surface of the image holder, A means for forming an electrostatic image on the surface of the charged image holder, A developing means comprising: containing the electrostatic image developer described in claim 10; and developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer; A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, Fixing means for fixing the toner image transferred to the surface of the recording medium, An image forming apparatus equipped with the following features.

14. A charging step in which the surface of the image holder is charged, A step of forming an electrostatic image on the surface of the charged image holder, A developing step of developing the electrostatic image formed on the surface of the image holder as a toner image using the electrostatic image developer described in claim 10, A transfer step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium, A fixing step for fixing the toner image transferred to the surface of the recording medium, An image forming method having the following characteristics.

15. It comprises first to sixth image forming units of an electrophotographic method that form images of pink, yellow, magenta, cyan, black, and green, The image forming unit that forms the green image contains the electrostatic image developer described in claim 10. Image forming apparatus.

16. The system has first to sixth image forming steps using an electrophotographic method to form images of pink, yellow, magenta, cyan, black, and green. The image forming step for forming the green image uses the electrostatic image developer described in claim 10. Image forming method.

Images