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

Abstract

To provide a green toner for electrostatic charge image development that reduces the occurrence of fogging.SOLUTION: A green toner for electrostatic charge image development includes a green toner particle and oil-treated silica particles externally attached to the green toner particle. The green toner particle contains a binder resin, an azomethine fluorescent pigment having an emission peak in a wavelength region of 500 nm or more and 550 nm or less in an emission spectrum, and a non-fluorescent pigment having a reflection peak in a wavelength region of 480 nm or more and 540 nm or less in a reflection spectrum. The mass proportion of the azomethine fluorescent pigment in the green toner particle is 3% by mass or more and 10% by mass or less. The mass ratio M1 / M2 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 1 or more and 5 or less.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

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

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

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

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

[0006] Patent Document 5 discloses an electrostatic charge image developing toner containing a binder resin containing a polyester resin and a styrene (meth)acrylic resin, toner particles in which the styrene (meth)acrylic resin forms domains having an average diameter of 300 nm or more and 800 nm or less, and oil-treated silica particles having an oil release amount of 3% by mass or more and 30% by mass or less.

[0007] Patent Document 6 discloses a bright toner containing a binder resin, a release agent, and a bright pigment and having release agent domains, and silicone oil-treated silica particles. In the cross-sectional observation of the bright toner particles, a bright toner in which the average major axis length Dw of the release agent domains and the average major axis length Dp of the bright pigment satisfy the formula (1): 0.3 ≦ Dw / Dp ≦ 1.0 is disclosed.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0009] The image display section of an electronic device generally uses the so-called RGB color mode, which expresses colors by combining 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 expresses colors by combining four colors: cyan (C), magenta (M), yellow (Y), and black (K). When reproducing an image expressed in the RGB color mode onto a recording medium in the CMYK color mode, secondary colors such as green, pink, or orange tend to fade.

[0010] For the purpose of enhancing the color reproducibility of green, pink, or orange in electrophotographic image formation, green toner, pink toner, or orange toner has been developed. As green toner, toner containing a yellow fluorescent dye (e.g., C.I. Solvent Green 5) and a green pigment or a blue pigment is 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 using green toner containing a fluorescent dye.

[0011] For the purpose of reproducing colors with higher brightness and higher chroma, the development of green toner in which a fluorescent dye is replaced with a fluorescent pigment is underway. However, since the crystals of fluorescent pigments have relatively low electrical resistance, green toner containing a fluorescent pigment is difficult to triboelectrically charge. And when the charging of the toner is low, fogging (a phenomenon where toner adheres to non-image areas of the recording medium) occurs. Fogging becomes prominent when the residence time of the toner in the developing device is short (i.e., the time the toner is agitated is short), such as when continuously outputting high-density images.

[0012] This disclosure has been made under the above circumstances. An object of this disclosure is to provide an electrostatic charge image developing green toner that is less likely to cause fogging compared to an electrostatic charge image developing green toner without externally added oil-treated silica particles.

Means for Solving the Problem

[0013] Means for solving the above problems include the following aspects. <1> It contains a binder resin, an azomethine fluorescent pigment having an emission peak in the wavelength region of 500 nm or more and 550 nm or less in the emission spectrum, and a non-fluorescent pigment having a reflection peak in the wavelength region of 480 nm or more and 540 nm or less in the reflection spectrum. The mass ratio of the azomethine fluorescent pigment in the green toner particles is 3% by mass or more and 10% by mass or less. The mass ratio M1 / M2 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 1 or more and 5 or less. Green toner particles, Including oil-treated silica particles externally added to the green toner particles. Green toner for electrostatic charge image development. <2> The oil-treated silica particles are oil-treated silica particles having a free oil amount of 5% by mass or more and 30% by mass or less. The green toner for electrostatic charge image development according to <1>. <3> When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the oil-treated silica particles detached from the green toner particles are 20% by mass or more and 40% by mass or less of the oil-treated silica particles externally added to the green toner particles. The green toner for electrostatic charge image development according to <1> or <2>. <4> The average primary particle size of the oil-treated silica particles is 15 nm or more and 200 nm or less. The green toner for electrostatic charge image development according to any one of <1> to <3>. <5> The oil-treated silica particles are silicone oil-treated silica particles. The green toner for electrostatic charge image development according to any one of <1> to <4>. <6> Containing 0.5 parts by mass or more and 5 parts by mass or less of the oil-treated silica particles with respect to 100 parts by mass of the green toner particles, The green toner for electrostatic charge image development according to any one of <1> to <5>. <7> The volume average particle diameter D1 of the azomethine fluorescent pigment is 30 nm or more and 800 nm or less, The volume average particle diameter D1 of the azomethine fluorescent pigment and the volume average particle diameter D2 of the non-fluorescent pigment satisfy the relationship D1 > D2, The green toner for electrostatic charge image development according to any one of <1> to <6>. <8> The azomethine fluorescent pigment is C.I. Pigment Yellow 101, The green toner for electrostatic charge image development according to any one of <1> to <7>. <9> The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59 and C.I. Pigment Blue 76, The green toner for electrostatic charge image development according to any one of <1> to <8>.

[0014] <10> An electrostatic charge image developer containing the green toner for electrostatic charge image development according to any one of <1> to <9>. <11> A toner cartridge that houses the green toner for electrostatic charge image development according to any one of <1> to <9> and is detachable from an image forming apparatus. <12> A developing unit that houses the electrostatic charge image developer according to <10> and develops an electrostatic charge image formed on the surface of an image carrier as a toner image, A process cartridge that is detachable from an image forming apparatus. <13> An image carrier, A charging unit that charges the surface of the image carrier, Electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier; Developing means for accommodating the electrostatic charge developer described in <10> and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge developer; Transfer means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; Fixing means for fixing the toner image transferred to the surface of the recording medium; An image forming apparatus comprising the above. <14> A charging step of charging the surface of the image carrier; An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier; A developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge developer described in <10>; A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; A fixing step of fixing the toner image transferred to the surface of the recording medium; An image forming method having the above. <15> An electrophotographic first to sixth image forming units for forming images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming unit for forming the green image accommodates the electrostatic charge developer described in <10>. An image forming apparatus. <16> An electrophotographic first to sixth image forming steps for forming images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming step for forming the green image uses the electrostatic charge developer described in <10>. An image forming method.

Advantages of the Invention

[0015] According to <1>, <5>, <8> or <9>, there is provided an electrostatic charge image developing green toner in which fogging is less likely to occur as compared with an electrostatic charge image developing green toner to which oil-treated silica particles are not externally added. According to <2>, there is provided an electrostatic charge image developing green toner in which fogging is less likely to occur as compared with an electrostatic charge image developing green toner in which the free oil amount of oil-treated silica particles is less than 5% by mass. According to <3>, there is provided an electrostatic charge image developing green toner in which fogging is less likely to occur as compared with an electrostatic charge image developing green toner in which the oil-treated silica particles detached from the green toner particles are less than 20% by mass. According to <4>, there is provided an electrostatic charge image developing green toner in which fogging is less likely to occur as compared with an electrostatic charge image developing green toner in which the average primary particle diameter of the oil-treated silica particles is less than 15 nm. According to <6>, there is provided an electrostatic charge image developing green toner in which fogging is less likely to occur as compared with an electrostatic charge image developing green toner in which the externally added amount of the oil-treated silica particles is less than 0.5 part by mass. According to <7>, there is provided an electrostatic charge image developing green toner in which fixing offset is less likely to occur as compared with an electrostatic charge image developing green toner containing green toner particles in which the volume average particle diameter D1 of the azomethine fluorescent pigment is less than 30 nm or more than 800 nm, or green toner particles in which the volume average particle diameter D1 of the azomethine fluorescent pigment and the volume average particle diameter D2 of the non-fluorescent pigment satisfy D1 < D2.

[0016] According to <10>, there is provided an electrostatic charge image developer in which fogging is less likely to occur as compared with the case where no oil-treated silica particles are externally added to the electrostatic charge image developing green toner. According to <11>, there is provided a toner cartridge in which fogging is less likely to occur as compared with the case where no oil-treated silica particles are externally added to the electrostatic charge image developing green toner. According to <12>, there is provided a process cartridge in which fogging is less likely to occur as compared with the case where no oil-treated silica particles are externally added to the electrostatic charge image developing green toner. According to <13> or <15>, an image forming apparatus is provided in which fogging is less likely to occur as compared with the case where oil-treated silica particles are not externally added to the green toner for electrostatic charge image development. According to <14> or <16>, an image forming method is provided in which fogging is less likely to occur as compared with the case where oil-treated silica particles are not externally added to the green toner for electrostatic charge image development.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments.

[0019] In the present disclosure, “A and / or B” is synonymous with “at least one of A and B”. That is, “A and / or B” means that it may be only A, only B, or a combination of A and B.

[0020] In the present disclosure, the numerical range indicated using “~” indicates a range including the numerical values described before and after “~” as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stepwise descriptions. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0021] In the present disclosure, the term "step" includes not only independent steps but also steps that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0022] When embodiments in the present disclosure are described with reference to the drawings, the configuration of the embodiments is not limited to the configuration shown in the drawings. Also, the sizes of the members in each drawing are conceptual, and the relative size relationships between the members are not limited thereto.

[0023] In the present disclosure, each component may contain a plurality of corresponding substances. When referring to the amount of each component in a composition, if there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition. In the present disclosure, the particles corresponding to each component may contain a plurality of types. When there are a plurality of types of particles corresponding to each component in the composition, the particle diameter of each component means a value for the mixture of the plurality of types of particles present in the composition, unless otherwise specified.

[0024] When a compound is represented by a structural formula in the present disclosure, it may be represented by a structural formula in which the symbols (C and H) representing carbon atoms and hydrogen atoms in a hydrocarbon group and / or hydrocarbon chain are omitted.

[0025] In the present disclosure, "(meth)acryl" is an expression that includes both acrylic and methacrylic, and "(meth)acrylate" is an expression that includes both acrylate and methacrylate.

[0026] In the present disclosure, "toner for electrostatic charge image development" is also referred to as "toner", "green toner for electrostatic charge image development" is also referred to as "green toner", "electrostatic charge image developer" is also referred to as "developer", and "carrier for electrostatic charge image development" is also referred to as "carrier".

[0027] In the present disclosure, Colour Index is abbreviated as "C.I.".

[0028] <Green toner for electrostatic charge image development> In the present disclosure, the green toner means a toner in which the hue angle h of a solid image (image with a density of 100%) formed on coated paper is 128.5° or more and 144.5° or less. The hue angle h is the angle calculated by the following formula from the a * a * b * value and b * value in the CIE1976L * color system. Hue angle h = tan -1 (b * / a * ) In the present disclosure, the hue angle h of the solid image (image with a density of 100%) formed by the green toner on coated paper is preferably 131° or more and 143° or less, and more preferably 135° or more and 140° or less.

[0029] In the present disclosure, the solid image (image with a density of 100%) formed by the green toner on coated paper has a lightness L * a * b * in the CIE1976L * color system of 70 or more and a chroma C * of 85 or more. The chroma C * is a value calculated by the following formula from the a * a * b * value and b * value in the CIE1976L * color system. Chroma C * ={(a * ) 2 +(b * ) 2} 0.5

[0030] In the present disclosure, the fluorescent pigment means a pigment that emits light by external light energy, and the non-fluorescent pigment means a pigment that does not emit light by external light energy. Generally, the fluorescent pigment exhibits color by reflected light and emitted light, and the non-fluorescent pigment exhibits color only by reflected light.

[0031] The green toner according to this embodiment contains green toner particles. The green toner particles contain a binder resin, an azomethine fluorescent pigment having an emission peak in the region of the emission spectrum with a wavelength of 500 nm or more and 550 nm or less, and a non-fluorescent pigment having a reflection peak in the region of the reflection spectrum with a wavelength of 480 nm or more and 540 nm or less. That is, the green toner particles in this embodiment are toner particles containing a yellow fluorescent pigment and a green pigment or a blue pigment.

[0032] Hereinafter, the "azomethine fluorescent pigment having an emission peak in the region of the emission spectrum with a wavelength of 500 nm or more and 550 nm or less" is referred to as "azomethine fluorescent pigment (Y)", and the "non-fluorescent pigment having a reflection peak in the region of the reflection spectrum with a wavelength of 480 nm or more and 540 nm or less" is referred to as "pigment (G)".

[0033] In the green toner particles in this embodiment, the mass ratio of the azomethine fluorescent pigment (Y) in the green toner particles is 3% by mass or more and 10% by mass or less, and the ratio M1 / M2 of the content M1 of the azomethine fluorescent pigment (Y) to the content M2 of the pigment (G) on a mass basis is 1 or more and 5 or less. When the mass ratio of the azomethine fluorescent pigment (Y) is less than 3% by mass or more than 10% by mass, it is difficult for the image to exhibit the desired green color. From the viewpoint of the image exhibiting the desired green color, the mass ratio of the azomethine fluorescent pigment (Y) is 3% by mass or more and 10% by mass or less, preferably 4% by mass or more and 9% by mass or less, and more preferably 5% by mass or more and 8% by mass or less. When the ratio M1 / M2 is less than 1, the hue of the image shifts to a bluish color. When the ratio M1 / M2 is more than 5, the hue of the image shifts to a yellowish color. From the viewpoint of the image exhibiting the desired green color, the ratio M1 / M2 is 1 or more and 5 or less, preferably 1.5 or more and 4.5 or less, and more preferably 2 or more and 4 or less.

[0034] In the green toner particles in this embodiment, it is preferable that the total content of the azomethine fluorescent pigment (Y) and the pigment (G) with respect to the entire green toner particles is 5% by mass or more and 15% by mass or less. When the total content of the two pigments is 5% by mass or more, the saturation of the green image is high. From the viewpoint of increasing the saturation of the green image, the total content of the two pigments is preferably 5% by mass or more, more preferably 7% by mass or more, and still more preferably 9% by mass or more. When the total content of the two pigments is 15% by mass or less, the lightness of the green image is high. From the viewpoint of increasing the lightness of the green image, the total content of the two pigments is preferably 15% by mass or less, more preferably 14% by mass or less, and still more preferably 12% by mass or less.

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

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

[0037] When the green toner according to this embodiment forms a solid image (image with a density of 100%) on coated paper, the CIE1976L * a * b *It is preferable that the color difference ΔE in the color system is 13.5 or less. The smaller the color difference ΔE, the more preferable it is, more preferably 10 or less, still more preferably 6.5 or less, still more preferably 3 or less, still more preferably 1 or less, and ideally 0.

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

[0039]

Equation

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

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

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

[0043] The green toner according to this embodiment contains oil-treated silica particles externally added to the green toner particles. In the green toner according to this embodiment, since the green toner particles contain an azomethine fluorescent pigment (Y) and are relatively difficult to triboelectrically charge, oil is supplied from the oil-treated silica particles to the carrier, increasing the electrical resistance of the carrier and improving the performance of the carrier to triboelectrically charge the toner. Therefore, the green toner according to this embodiment is sufficiently charged. Therefore, the green toner according to this embodiment is less likely to cause fogging (a phenomenon in which toner adheres to the non-image area of the recording medium) compared to a green toner without externally added oil-treated silica particles.

[0044] Hereinafter, the configuration of the green toner according to this embodiment will be described in detail.

[0045] [Green Toner Particles] The green toner particles contain a binder resin, an azomethine fluorescent pigment (Y), and a pigment (G), and are configured to include a release agent and other additives as necessary.

[0046] -Azomethine Fluorescent Pigment (Y)- The azomethine fluorescent pigment (Y) has an emission peak in the region of 500 nm or more and 550 nm or less in the emission spectrum. The emission peak of the azomethine fluorescent pigment (Y) is preferably in the region of 505 nm or more and 540 nm or less, more preferably in the region of 510 nm or more and 535 nm or less, and still more preferably in the region of 515 nm or more and 530 nm or less.

[0047] The azomethine fluorescent pigment (Y) is a pigment having an azomethine structure (that is, -R 1 C=N-, R 1 is a hydrogen atom or a monovalent substituent) in the molecule. As the azomethine fluorescent pigment (Y), it is preferably a bisazomethine, that is, -R 1 C=N-N=CR 2 -(R 1 and R 2 are each independently a hydrogen atom or a monovalent substituent) in the molecule.

[0048] Examples of the azomethine fluorescent pigment (Y) include the following azomethine compounds (1) to (3).

[0049]

Chemical Formula

[0050] The emission peak of the azomethine compound (1) is 520 nm. The emission peak of the azomethine compound (2) is 510 nm. The emission peak of the azomethine compound (3) is 520 nm.

[0051] 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).

[0052] As the azomethine fluorescent pigment (Y), C.I. Pigment Yellow 101 is preferred. C.I. Pigment Yellow 101 is azomethine compound (1).

[0053] From the viewpoint of achieving a good balance in terms of dispersibility in toner particles, color developability on a recording medium, fixability to the recording medium, etc., the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) is preferably 30 nm or more and 800 nm or less, more preferably 50 nm or more and 700 nm or less, still more preferably 150 nm or more and 600 nm or less, and even more preferably 250 nm or more and 400 nm or less. The volume average particle diameter of the pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction / scattering particle size distribution analyzer (for example, LA-700 manufactured by Horiba, Ltd.). Draw the particle size distribution based on volume from the small particle size side, and the particle diameter at which the cumulative value reaches 50% is defined as the volume average particle diameter.

[0054] From the viewpoint of suppressing fixing offset (a phenomenon in which a toner image adheres to a fixing member and peels off from the recording medium when the toner image is fixed to the recording medium), in the green toner according to this embodiment, the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) is 30 nm or more and 800 nm or less, and it is preferable that the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) and the volume average particle diameter D2 of the pigment (G) satisfy the relationship D1 > D2. In the above, D1 is more preferably 50 nm or more and 700 nm or less, still more preferably 150 nm or more and 600 nm or less, and even more preferably 250 nm or more and 400 nm or less.

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

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

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

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

[0059] From the viewpoint of achieving a good balance among the dispersibility in toner particles, the color rendering property on the recording medium, the fixing property to the recording medium, etc., the volume average particle diameter D2 of the pigment (G) is preferably 20 nm or more and 400 nm or less, more preferably 50 nm or more and 300 nm or less, still more preferably 100 nm or more and 250 nm or less, and still more preferably 120 nm or more and 200 nm or less. The volume average particle diameter of the pigment is measured by dispersing the pigment in an aqueous solution of a surfactant and using a laser diffraction particle size distribution analyzer (e.g., LA-700 manufactured by Horiba, Ltd.). Draw the particle size distribution based on volume from the small particle size side, and the particle diameter at which the cumulative percentage is 50% is defined as the volume average particle diameter.

[0060] From the perspective of achieving a good balance in terms of dispersibility in toner particles, color development on a recording medium, fixing property to the recording medium, etc., it is preferable that the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) and the volume average particle diameter D2 of the pigment (G) satisfy the relationship D1 > D2. From the perspective of enhancing the lightness and chroma of the green image, the ratio D1 / D2 of the volume average particle diameter D1 of the azomethine fluorescent pigment (Y) to the volume average particle diameter D2 of the pigment (G) is preferably more than 1 and 3 or less, more preferably 1.2 or more and 2.5 or less, and even more preferably 1.5 or more and 2 or less.

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

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

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

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

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

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

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

[0068] The weight average molecular weight (Mw) of the polyester resin is preferably 5,000 or higher and 1,000,000 or lower, more preferably 7,000 or higher and 500,000 or lower. The number average molecular weight (Mn) of the polyester resin is preferably 2,000 or higher and 100,000 or lower. The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or higher and 100 or lower, more preferably 2 or higher and 60 or lower. The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out using Tosoh's GPC·HLC-8120GPC as the measuring device, Tosoh's column·TSKgel SuperHM-M (15 cm), and THF solvent. The weight average molecular weight and the number average molecular weight are calculated using the molecular weight calibration curve prepared from this measurement result with a monodisperse polystyrene standard sample.

[0069] The polyester resin is obtained by a known production method. Specifically, for example, it can be obtained by a method in which the polymerization temperature is 180°C or higher and 230°C or lower, and the inside of the reaction system is depressurized as necessary, and the reaction is carried out while removing water and alcohol generated during condensation. When the monomer of the raw material is not soluble or compatible at the reaction temperature, a high-boiling solvent may be added as a dissolution aid to dissolve it. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. When there are monomers with poor compatibility, it is advisable to first condense the monomers with poor compatibility with the acid or alcohol to be polycondensed with that monomer and then carry out polycondensation with the main component.

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

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

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

[0073] The content of the release agent is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, based on the total toner particles.

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

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

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

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

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

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

[0080] [Oil-treated silica particles] The green toner according to this embodiment contains oil-treated silica particles as an external additive. Examples of the silica particles of the oil-treated silica particles include dry silica particles and wet silica particles.

[0081] Examples of the dry silica particles include combustion method silica (fumed silica) obtained by burning a silane compound, and deflagration method silica obtained by explosively burning metallic silicon powder. Examples of the wet silica particles include wet silica particles (precipitated silica synthesized and aggregated under alkaline conditions, gel method silica particles synthesized and aggregated under acidic conditions) obtained by a neutralization reaction between sodium silicate and a mineral acid, colloidal silica particles (silica sol particles) obtained by polymerizing acidic silica after making it alkaline, and sol-gel method silica particles obtained by hydrolysis of an organic silane compound (for example, alkoxysilane).

[0082] Examples of the oil of the oil-treated silica particles include silicone oil, paraffin oil, fluorine oil, mineral oil, and vegetable oil. The oil may be used alone or in combination of two or more.

[0083] The oil treatment of the silica particles is performed, for example, by dispersing the silica particles in a mixed solution of alcohol and oil and then distilling off the alcohol using an evaporator to dry it.

[0084] As the oil-treated silica particles, silicone oil-treated silica particles are preferred. As the silicone oil of the silicone oil-treated silica particles, dimethyl silicone oil is preferred.

[0085] From the viewpoint of supplying an appropriate amount of oil to the carrier, the average primary particle size of the oil-treated silica particles is preferably 15 nm or more and 200 nm or less, more preferably 40 nm or more and 150 nm or less, and still more preferably 80 nm or more and 120 nm or less.

[0086] The method for determining the average primary particle size of the oil-treated silica particles is as follows. The green toner is photographed at a magnification of 40,000 times using a scanning electron microscope (SEM) (Hitachi High-Technologies Corporation, S-4800) equipped with an energy dispersive X-ray analyzer (EDX analyzer) (Horiba, Ltd., EMAX Evolution X-Max80mm 2 ). Based on the presence of silicon atoms, oxygen atoms, and carbon atoms by EDX analysis, 500 primary particles of the oil-treated silica particles are specified from within one field of view. The images of 500 oil-treated silica particles are analyzed with image processing analysis software WinRoof (Miyaya Shoko Co., Ltd.) to obtain the equivalent circle diameter of each primary particle. The equivalent circle diameter at which the cumulative value from the small diameter side reaches 50% in the number-based distribution of the equivalent circle diameter is defined as the average primary particle size.

[0087] The oil-treated silica particles are preferably oil-treated silica particles having a free oil content of 5% by mass or more and 30% by mass or less. When the free oil content of the oil-treated silica particles is 5% by mass or more, an appropriate amount of oil can be supplied to the carrier. From this viewpoint, the free oil content of the oil-treated silica particles is more preferably 8% by mass or more, and still more preferably 10% by mass or more. When the free oil content of the oil-treated silica particles is 30% by mass or less, the inside of the image forming apparatus is less likely to be contaminated with oil. From this viewpoint, the free oil content of the oil-treated silica particles is more preferably 28% by mass or less, and still more preferably 25% by mass or less. The method for determining the free oil content of the oil-treated silica particles is as follows.

[0088] Using oil-treated silica particles as a sample, proton NMR measurement is performed under the following conditions. A calibration curve is created using tetramethylsilane as a reference substance. The amount of free oil is converted from the detected peak intensity. The mass ratio (mass %) of free oil in the total mass of the oil-treated silica particles is calculated. · Nuclear magnetic resonance apparatus: JEOL Ltd. AL-400, magnetic field 9.4 T, H nucleus 400 MHz · Sample tube: Zirconia sample tube, diameter 5 mm · Solvent: Deuterated chloroform · Reference substance: Tetramethylsilane · Measurement frequency: Δ87 kHz / 400 MHz (=Δ20 ppm) · Measurement temperature: 25 °C · Number of integrations: 16 times · Resolution: 0.24 Hz (32000 point)

[0089] The amount of free oil in the oil-treated silica particles can be controlled by increasing or decreasing the amount of oil used during the oil treatment of the silica particles.

[0090] For the green toner according to this embodiment, when the green toner is dispersed in water containing a surfactant and ultrasonic treatment is performed at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the oil-treated silica particles detached from the green toner particles are preferably 20 mass % or more and 40 mass % or less of the oil-treated silica particles externally added to the green toner particles. The mass ratio of the oil-treated silica particles detached from the green toner particles by the above ultrasonic treatment is also referred to as the weak adhesion ratio of the oil-treated silica particles.

[0091] When the weak adhesion ratio of the oil-treated silica particles is 20 mass % or more, an appropriate amount of oil can be supplied to the carrier. From this viewpoint, the weak adhesion ratio of the oil-treated silica particles is more preferably 25 mass % or more, and still more preferably 28 mass % or more. When the weak adhesion ratio of the oil-treated silica particles is 40% by mass or less, the interior of the image forming apparatus is less likely to be contaminated with oil. From this perspective, the weak adhesion ratio of the oil-treated silica particles is more preferably 38% by mass or less, and even more preferably 35% by mass or less.

[0092] The method for determining the weak adhesion ratio of the oil-treated silica particles is as follows. Prepare an aqueous surfactant solution containing 0.5% by mass of a surfactant (Neugen ET-165, Dai-ichi Kogyo Seiyaku Co., Ltd.) in ion-exchanged water. Put 50 mL of the aqueous surfactant solution into a 100 mL glass beaker, add 4 g of green toner thereto, and stir with a magnetic stirrer at a rotation speed of 100 rpm for 5 minutes to prepare a toner dispersion. Prepare two such toner dispersions. Insert the probe of an ultrasonic homogenizer (VCX750, Sonic and Material) into one of the toner dispersions (insert it until the distance between the tip of the probe and the bottom of the beaker is 1.0 cm), and apply ultrasonic waves with an output of 20 W and a frequency of 20 kHz for 1 minute. Centrifuge the toner dispersion to fractionate the green toner particles, the oil-treated silica particles, and other external additives by density, and collect the fraction containing the oil-treated silica particles. Dry the fraction and measure the mass of the oil-treated silica particles. Let this mass (i.e., the mass of the oil-treated silica particles weakly adhered to the green toner particles) be S1. Insert the probe of an ultrasonic homogenizer (VCX750, Sonic and Material) into the other toner dispersion (insert it until the distance between the tip of the probe and the bottom of the beaker is 1.0 cm), and apply ultrasonic waves with an output of 100 W and a frequency of 10 kHz for 30 minutes. This ultrasonic intensity is such that all of the oil-treated silica particles can be detached from the green toner particles. Centrifuge the toner dispersion to fractionate the green toner particles, the oil-treated silica particles, and other external additives by density, and collect the fraction containing the oil-treated silica particles. Dry the fraction and measure the mass of the oil-treated silica particles. Let this mass (i.e., the total mass of the oil-treated silica particles externally added to the green toner) be S2. Let the value of S1 / S2×100 be the weak adhesion ratio (mass %) of the oil-treated silica particles.

[0093] The weak adhesion ratio of the oil-treated silica particles can be controlled by adjusting the rotation speed and / or rotation time of the blender or mixer when mixing the green toner particles and the oil-treated silica particles.

[0094] From the viewpoint of supplying an appropriate amount of oil to the carrier, the external addition amount of the oil-treated silica particles is preferably 0.5 parts by mass or more and 5 parts by mass or less, more preferably 0.8 parts by mass or more and 4 parts by mass or less, and still more preferably 1 part by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the green toner particles.

[0095] The content of the oil-treated silica particles is preferably 50% by mass or more and 100% by mass or less with respect to the total amount of the external additives contained in the green toner.

[0096] [Other external additives] The green toner according to the present embodiment may contain external additives other than the oil-treated silica particles. As the external additives other than the oil-treated silica particles, SrTiO 3 , TiO 2 , Al 2 O 3 , CuO, ZnO, SnO 2 , CeO 2 , Fe 2 O 3 , MgO, BaO, CaO, K 2 O, Na 2 O, ZrO 2 , CaO·SiO 2 , K 2 O·(TiO 2 ) n , Al 2 O 3 ·2SiO 2 , CaCO 3 , MgCO 3 , BaSO 4 , MgSO 4 and other inorganic particles can be mentioned.

[0097] The surface of the above inorganic particles is preferably subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing the inorganic particles in a hydrophobization treatment agent. The hydrophobization treatment agent is not particularly limited, and examples thereof include silane-based coupling agents, silicone oils, titanate-based coupling agents, aluminum-based coupling agents, and the like. These may be used alone or in combination of two or more.

[0098] Examples of the external additive include resin particles (resin particles such as polystyrene, polymethyl methacrylate, and melamine resin), cleaning agents (for example, metal salts of higher fatty acids typified by zinc stearate, particles of fluorine-based high molecular weight substances), and the like.

[0099] When the green toner according to this embodiment contains other external additives other than oil-treated silica particles, the addition amount of the other external additives is preferably 0.01 part by mass or more and 5 parts by mass or less, more preferably 0.01 part by mass or more and 2 parts by mass or less, based on 100 parts by mass of the toner particles.

[0100] [Manufacturing method of green toner] The green toner according to this embodiment is obtained by externally adding an external additive to the green toner particles after manufacturing the green toner particles. The external additive contains at least oil-treated silica particles.

[0101] The green toner particles may be manufactured by any of a dry method (for example, a kneading and pulverizing method, etc.) or a wet method (for example, an aggregation method, a suspension polymerization method, a dissolution and suspension method, etc.). There are no particular limitations on these manufacturing methods, and known manufacturing methods are adopted. Among these, it is preferable to obtain toner particles by the aggregation method.

[0102] When manufacturing the green toner particles by the aggregation method, the following manufacturing method is preferable. A step of preparing a resin particle dispersion liquid in which resin particles serving as a binder resin are dispersed (resin particle dispersion liquid preparation step); A step of preparing a fluorescent pigment (Y) dispersion liquid in which an azomethine fluorescent pigment (Y) is dispersed (fluorescent pigment (Y) dispersion liquid preparation step); A step of preparing a pigment (G) dispersion in which the pigment (G) is dispersed (pigment (G) dispersion preparation step); A step of aggregating the mixed particles in a mixed dispersion obtained by mixing a resin particle dispersion, a fluorescent pigment (Y) dispersion, and a pigment (G) dispersion to form aggregated particles (aggregated particle formation step); A step of heating the aggregated particle dispersion in which the aggregated particles are dispersed to fuse and unite the aggregated particles to form green toner particles (fusion and unification step); A manufacturing method having.

[0103] Hereinafter, the details of each step will be described. In the following description, the green toner particles are simply referred to as toner particles. In the following description, a method for obtaining toner particles containing a release agent will be described, but the release agent is used as necessary.

[0104] - Resin particle dispersion preparation step - The resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium with a surfactant.

[0105] Examples of the dispersion medium used for the resin particle dispersion include aqueous media. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0106] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Nonionic surfactants such as systems are mentioned. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0107] In a resin particle dispersion, as a method for dispersing resin particles in a dispersion medium, for example, general dispersion methods such as a rotary shear type homogenizer, a ball mill having media, a sand mill, a dyno mill, etc. can be mentioned. Further, depending on the type of resin particles, the resin particles may be dispersed in the dispersion medium by a phase inversion emulsification method. The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase) for neutralization, and then an aqueous medium (W phase) is introduced to perform a phase inversion from W / O to O / W, and the resin is dispersed in the aqueous medium in a particulate form.

[0108] As the volume average particle diameter of the resin particles dispersed in the resin particle dispersion, for example, 0.01 μm or more and 1 μm or less is preferable, 0.08 μm or more and 0.8 μm or less is more preferable, and 0.1 μm or more and 0.6 μm or less is still more preferable. The volume average particle diameter of the resin particles is measured using the particle size distribution obtained by measurement with a laser diffraction type particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.). For the divided particle size range (channel), the cumulative distribution is subtracted from the small particle size side with respect to the volume, and the particle diameter at which the cumulative value becomes 50% with respect to all the particles is measured as the volume average particle diameter D50v. Note that the volume average particle diameter of the particles in other dispersions is also measured in the same manner.

[0109] The content of the resin particles contained in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0110] The method for preparing the release agent particle dispersion is the same as that of the resin particle dispersion. The content of the release agent particles contained in the release agent particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0111] - Fluorescent pigment (Y) dispersion preparation step - The fluorescent pigment (Y) dispersion is prepared, for example, by dispersing an azomethine fluorescent pigment (Y) in a dispersion medium with a surfactant.

[0112] Examples of the dispersion medium used for the fluorescent pigment (Y) dispersion include an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0113] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0114] Examples of the method for dispersing the azomethine fluorescent pigment (Y) in the dispersion medium include dispersion methods using a rotary shear homogenizer, a ball mill having media, a sand mill, a dyno mill, a kimi mill, and the like.

[0115] The volume average particle size of the azomethine fluorescent pigment (Y) dispersed in the fluorescent pigment (Y) dispersion is preferably, for example, 30 nm or more and 800 nm or less, more preferably 50 nm or more and 700 nm or less, still more preferably 150 nm or more and 600 nm or less, and still more preferably 250 nm or more and 400 nm or less. The particle size of the azomethine fluorescent pigment (Y) can be adjusted, for example, by the method and time of the dispersion treatment.

[0116] The content of the azomethine fluorescent pigment (Y) contained in the fluorescent pigment (Y) dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0117] - Pigment (G) Dispersion Preparation Step - The pigment (G) dispersion is prepared, for example, by dispersing the pigment (G) in a dispersion medium with a surfactant.

[0118] Examples of the dispersion medium used in the pigment (G) dispersion include aqueous media. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

[0119] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0120] Examples of the method for dispersing the pigment (G) in the dispersion medium include dispersion methods using a rotary shear type homogenizer, a ball mill having media, a sand mill, a dyno mill, a kimi mill, etc.

[0121] The volume average particle diameter of the pigment (G) dispersed in the pigment (G) dispersion is preferably, for example, 20 nm or more and 400 nm or less, more preferably 50 nm or more and 300 nm or less, still more preferably 100 nm or more and 250 nm or less, and still more preferably 120 nm or more and 200 nm or less. The particle diameter of the pigment (G) can be adjusted, for example, by the method and time of the dispersion treatment.

[0122] The content of the pigment (G) contained in the pigment (G) dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0123] -Agglomerate Particle Formation Step- 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, resin particles, an azomethine fluorescent pigment (Y), a pigment (G), and release agent particles are hetero-aggregated to form aggregated particles containing resin particles, an azomethine fluorescent pigment (Y), a pigment (G), and release agent particles, which have a diameter close to the diameter of the target toner particles.

[0124] Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Then, the mixture is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, glass transition temperature of the resin particles - 30°C or more and glass transition temperature of the resin particles - 10°C or less) to aggregate the particles dispersed in the mixed dispersion and form aggregated particles. In the aggregated particle formation step, for example, while stirring the mixed dispersion with a rotary shear homogenizer, a flocculant is added at room temperature (for example, 25°C), the pH of the mixed dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Then, heating may be performed.

[0125] Examples of the flocculant include a surfactant having a reverse polarity to the surfactant contained in the mixed dispersion, an inorganic metal salt, and a metal complex having a valence of 2 or more. When a metal complex is used as the flocculant, the amount of the surfactant used is reduced, and the charging characteristics are improved. An additive that forms a complex or a similar bond with the metal ion of the flocculant may be used as necessary together with the flocculant. As this additive, a chelating agent is preferably used.

[0126] Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and the like. As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and the like. The addition amount of the chelating agent is preferably 0.01 part by mass or more and 5.0 parts by mass or less, more preferably 0.1 part by mass or more and less than 3.0 parts by mass, based on 100 parts by mass of the resin particles.

[0127] -Fusion and unification step- Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10°C to 30°C higher than the glass transition temperature of the resin particles), to fuse and unify the aggregated particles and form toner particles.

[0128] Through the above steps, toner particles are obtained. After obtaining the aggregated particle dispersion in which the aggregated particles are dispersed, the aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed, and aggregated so that the resin particles further adhere to the surface of the aggregated particles to form second aggregated particles, and heating is performed on the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and unify the second aggregated particles to form toner particles having a core-shell structure. Through these steps, toner particles may be manufactured.

[0129] After the fusion and unification step is completed, the toner particles in the dispersion are subjected to a known cleaning step, solid-liquid separation step, and drying step to obtain toner particles in a dried state. From the viewpoint of chargeability, it is preferable to sufficiently perform substitution cleaning with ion-exchanged water in the cleaning step. From the viewpoint of productivity, it is preferable to perform suction filtration, pressure filtration, etc. in the solid-liquid separation step. From the viewpoint of productivity, it is preferable to perform freeze drying, airflow drying, fluidized drying, vibration-type fluidized drying, etc. in the drying step.

[0130] The toner according to this embodiment is manufactured, for example, by adding and mixing an external additive to the obtained toner particles in a dry state. The mixing may be performed, for example, by a V blender, a Henschel mixer, a Lodige mixer, or the like. Further, if necessary, coarse particles of the toner may be removed using a vibrating sieve, an air classifier, or the like.

[0131] When mixing toner particles and oil-treated silica particles, the weakly attached ratio of the oil-treated silica particles is controlled by adjusting the rotation speed and / or rotation time of a blender or a mixer.

[0132] <Electrostatic charge image developer> The electrostatic charge image developer according to this embodiment includes at least the green toner according to this embodiment. The electrostatic charge image developer according to this embodiment may be a one-component developer containing only the green toner according to this embodiment, or may be a two-component developer in which the green toner and a carrier are mixed.

[0133] There is no particular limitation on the carrier, and known carriers can be mentioned. Examples of the carrier include a coated carrier in which a resin is coated on the surface of a core material made of magnetic powder; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a resin impregnated type carrier in which porous magnetic powder is impregnated with a resin; and the like. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with a resin.

[0134] Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and the like.

[0135] Examples of the resin for coating and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester copolymer, straight silicone resin containing an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenol resin, epoxy resin, acrylic resin, and the like.

[0136] From the viewpoint of the chargeability of the carrier, the resin for coating is preferably an acrylic resin, and more preferably an acrylic resin having an alicyclic structure. The mass ratio of the acrylic resin in the total resin of the resin for coating is preferably 50% by mass or more, and more preferably 80% by mass or more. The mass ratio of the acrylic resin having an alicyclic structure in the total resin of the resin for coating is preferably 50% by mass or more, and more preferably 80% by mass or more.

[0137] The acrylic resin having an alicyclic structure preferably contains cyclohexyl (meth)acrylate as a polymerization component. The mass ratio of cyclohexyl (meth)acrylate in all polymerization components is preferably 75% by mass or more and 100% by mass or less, more preferably 85% by mass or more and 100% by mass or less, and still more preferably 95% by mass or more and 100% by mass or less. As the polymerization component other than cyclohexyl (meth)acrylate constituting the acrylic resin having an alicyclic structure, a lower alkyl ester of (meth)acrylic acid (for example, an alkyl (meth)acrylate having 1 to 9 carbon atoms in the alkyl group) is preferable. Examples of the lower alkyl ester of (meth)acrylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like. These monomers may be used alone or in combination of two or more.

[0138] The coating resin preferably further contains a nitrogen-containing (meth)acrylate resin, which preferably has an amino group. Examples of the nitrogen-containing (meth)acrylate resin include homopolymers or copolymers of nitrogen-containing (meth)acrylates such as dimethylaminomethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and dibutylaminomethyl (meth)acrylate; copolymers of nitrogen-containing (meth)acrylates and nitrogen-free monomers; and copolymers of nitrogen-free (meth)acrylates such as cycloalkyl (meth)acrylates and alkyl (meth)acrylates and nitrogen-containing monomers.

[0139] The resin for coating and the matrix resin may contain conductive particles and other additives. Examples of conductive particles include metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate. Examples of other additives include silica particles. The surfaces of these particles may be subjected to a hydrophobic treatment. The average particle size of these particles is preferably from 5 nm to 90 nm, more preferably from 5 nm to 70 nm, and even more preferably from 8 nm to 50 nm.

[0140] Examples of methods for coating the surface of the core material with a resin include a method of coating with a coating layer-forming solution in which the coating resin and various additives (used as necessary) are dissolved in a suitable solvent. The solvent is not particularly limited and may be selected taking into consideration the type of resin used, suitability for application, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer; a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material; a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air; and a kneader coater method in which the carrier core material and the solution for forming a coating layer are mixed in a kneader coater and then the solvent is removed.

[0141] In the two-component developer, the mixing ratio (mass ratio) of the green toner and the carrier is preferably from 1:100 to 30:100, more preferably from 3:100 to 20:100, with respect to green toner:carrier.

[0142] <Image forming apparatus, image forming method> The image forming apparatus and the image forming method according to the present embodiment will be described. The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image carrier, a developing unit that stores an electrostatic charge image developer and develops the electrostatic charge image formed on the surface of the image carrier as a toner image using the electrostatic charge image developer, a transfer unit that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing unit that fixes the toner image transferred to the surface of the recording medium. And, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

[0143] In the image forming apparatus according to the present embodiment, an image forming method (the image forming method according to the present embodiment) including a charging step of charging the surface of the image carrier, an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, a developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image using the electrostatic charge image developer according to the present embodiment, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium is performed.

[0144] The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image carrier to a recording medium; an intermediate transfer type apparatus that first transfers the toner image formed on the surface of the image carrier to the surface of an intermediate transfer member and then secondarily transfers the toner image transferred to the surface of the intermediate transfer member to the surface of a recording medium; an apparatus provided with cleaning means for cleaning the surface of the image carrier after transfer of the toner image and before charging; an apparatus provided with discharging means for discharging by irradiating the surface of the image carrier with discharging light after transfer of the toner image and before charging; and the like, and known image forming apparatuses are applicable. When the image forming apparatus according to the present embodiment is an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer member on which a toner image is transferred to the surface, a primary transfer means for primarily transferring the toner image formed on the surface of the image holding member to the surface of the intermediate transfer member, and a secondary transfer means for secondarily transferring the toner image transferred to the surface of the intermediate transfer member to the surface of the recording medium. A configuration having these components is applied.

[0145] In the image forming apparatus according to the present embodiment, for example, a portion including the developing means may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge that houses the electrostatic charge image developer according to the present embodiment and includes the developing means is preferably used.

[0146] Hereinafter, an example of the image forming apparatus according to the present embodiment is shown, but it is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the description of the others will be omitted.

[0147] In the following description, as an example of the image forming apparatus according to the present embodiment, a 6 - tandem type image forming apparatus in which six image forming units are arranged will be described. The tandem type image forming apparatus is not limited to this, and it may be a 5 - tandem type image forming apparatus in which five image forming units are arranged, a 4 - tandem type image forming apparatus in which four image forming units are arranged, and the like.

[0148] FIG. 1 is a schematic configuration diagram showing the image forming apparatus according to the present embodiment, and is a diagram showing a 6 - tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in Fig. 1 includes first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, which are electrophotographic image forming means for outputting images of respective colors of pink (P), yellow (Y), magenta (M), cyan (C), black (K), and green (G) based on color-separated image data. These image forming units (hereinafter may be simply referred to as "units") 10P, 10Y, 10M, 10C, 10K, and 10G are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10P, 10Y, 10M, 10C, 10K, and 10G may be process cartridges detachable from the image forming apparatus.

[0149] Below each of the units 10P, 10Y, 10M, 10C, 10K, and 10G, an intermediate transfer belt (an example of an intermediate transfer member) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around a driving 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 adapted to travel in a 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 so as to face the driving roll 22.

[0150] Each of the developing devices (an example of developing means) 4P, 4Y, 4M, 4C, 4K, and 4G of the units 10P, 10Y, 10M, 10C, 10K, and 10G is supplied with each toner of pink, yellow, magenta, cyan, black, and green stored in toner cartridges 8P, 8Y, 8M, 8C, 8K, and 8G.

[0151] Since the first to sixth units 10P, 10Y, 10M, 10C, 10K, and 10G have the same configuration and operation, the sixth unit 10G that forms a green image will be described as a representative here.

[0152] The sixth unit 10G has a photoreceptor 1G that acts as an image holding member. Around the photoreceptor 1G, there are arranged in order a charging roll (an example of charging means) 2G that charges the surface of the photoreceptor 1G to a predetermined potential, an exposure device (an example of electrostatic charge image forming means) 3G that exposes the charged surface with a laser beam based on a color-separated image signal to form an electrostatic charge image, a developing device (an example of developing means) 4G that supplies toner to the electrostatic charge image to develop it, a primary transfer roll (an example of primary transfer means) 5G that transfers the developed toner image onto an intermediate transfer belt 20, and a photoreceptor cleaning device (an example of cleaning means) 6G that removes the toner remaining on the surface of the photoreceptor 1G after primary transfer.

[0153] The primary transfer roll 5G is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoreceptor 1G. Bias power supplies (not shown) for applying a primary transfer bias are respectively connected to the primary transfer rolls 5Y, 5P, 5M, 5C, 5G, 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

[0154] Hereinafter, the operation of forming a green image in the sixth unit 10G will be described. First, prior to the operation, the surface of the photoreceptor 1G is charged to a potential of -600 V to -800 V by the charging roll 2G. The photoreceptor 1G is formed by laminating a photosensitive layer on a conductive substrate (for example, the volume resistivity at 20°C is 1×10 -6 Ωcm or less). This photosensitive layer is usually of high resistance (the resistance of a general resin), but has the property that when irradiated with a laser beam, the specific resistance of the portion irradiated with the laser beam changes. Therefore, a laser beam is irradiated from the exposure device 3G onto the charged surface of the photoreceptor 1G in accordance with green image data sent from a control unit (not shown). Thereby, an electrostatic charge image of a green image pattern is formed on the surface of the photoreceptor 1G.

[0155] The electrostatic charge image is an image formed on the surface of the photoreceptor 1G due to charging. By the laser beam from the exposure device 3G, the specific resistance of the irradiated portion of the photosensitive layer decreases, and the charged charges on the surface of the photoreceptor 1G flow. On the other hand, it is a so-called negative latent image formed by the charges remaining in the portion not irradiated with the laser beam. The electrostatic charge image formed on the photoreceptor 1G rotates to a predetermined development position as the photoreceptor 1G travels. And at this development position, the electrostatic charge image on the photoreceptor 1G is developed and visualized as a toner image by the developing device 4G.

[0156] Inside the developing device 4G, for example, an electrostatic charge image developer containing at least green toner and carrier is accommodated. The green toner is triboelectrically charged by being agitated inside the developing device 4G and has the same polarity (negative polarity) charge as the charged charges on the photoreceptor 1G and is held on a developer roll (an example of a developer holding member). And as the surface of the photoreceptor 1G passes through the developing device 4G, the green toner electrostatically adheres to the discharged latent image portion on the surface of the photoreceptor 1G, and the latent image is developed by the green toner. The photoreceptor 1G on which the green toner image is formed continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1G is conveyed to a predetermined primary transfer position.

[0157] When the green toner image on the photoreceptor 1G is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5G, and the electrostatic force from the photoreceptor 1G toward the primary transfer roll 5G acts on the toner image, and the toner image on the photoreceptor 1G is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is the opposite polarity (+) to the polarity (-) of the toner, and in the first unit 10G, it is controlled, for example, to +10 μA by a control unit (not shown).

[0158] After transferring the toner image to the intermediate transfer belt 20, the photoreceptor 1G continues to rotate and comes into contact with the cleaning blade provided in the photoreceptor cleaning device 6G. The toner remaining on the photoreceptor 1G is removed and recovered by the photoreceptor cleaning device 6G.

[0159] The intermediate transfer belt 20 is sequentially conveyed through the first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G, and toner images of each color are superimposed and multi-transferred.

[0160] The intermediate transfer belt 20 on which six-color toner images are multi-transferred through the first to sixth units reaches a secondary transfer section composed 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 secondary transfer means) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, the recording paper (an example of a recording medium) P is fed at a predetermined timing into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a supply mechanism, and a secondary transfer bias is applied to the counter roll 24. The transfer bias applied at this time is a (-) polarity of the same polarity as the polarity (-) of the toner, and an electrostatic force directed from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 20 is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) that detects the resistance of the secondary transfer section, and is voltage-controlled.

[0161] After the toner image is transferred onto the recording paper P, the intermediate transfer belt 20 continues to run and comes into contact with a cleaning blade provided in the intermediate transfer body cleaning device 21. The toner remaining on the intermediate transfer belt 20 is removed and recovered by the intermediate transfer body cleaning device 21.

[0162] The recording paper P onto which the toner image is transferred is fed into the pressure contact portion (nip portion) of a pair of fixing rolls in the fixing device (an example of fixing means) 28, and the toner image is fixed onto the recording paper P to form a fixed image.

[0163] Examples of the recording paper P onto which the toner image is transferred include plain paper used in electrophotographic copiers, printers, etc. Examples of the recording medium include OHP sheets in addition to the recording paper P. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper obtained by coating the surface of plain paper with resin or the like, art paper for printing, etc. are preferably used.

[0164] The recording paper P on which the fixing of the color image is completed is carried out toward the discharging unit, and a series of color image forming operations are terminated.

[0165] <Process cartridge, toner cartridge> The process cartridge according to the present embodiment will be described. The process cartridge according to the present embodiment contains the electrostatic charge image developer according to the present embodiment, and includes developing means for developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer, and is a process cartridge that is detachable from the image forming apparatus.

[0166] The process cartridge according to the present embodiment is not limited to the above configuration, and may be configured to include developing means and at least one selected from other means such as an image carrier, charging means, electrostatic charge image forming means, and transfer means, etc. as necessary.

[0167] Hereinafter, an example of the process cartridge according to the present embodiment is shown, but it is not necessarily limited thereto. In the following description, the main parts shown in the drawings will be described, and the others will be omitted from the description.

[0168] FIG. 2 is a schematic configuration diagram showing the process cartridge according to the present embodiment. The process cartridge 200 shown in FIG. 2 is configured by integrally combining and holding, for example, a photosensitive member 107 (an example of an image carrier), a charging roll 108 (an example of charging means) provided around the photosensitive member 107, a developing device 111 (an example of developing means), and a photosensitive member cleaning device 113 (an example of cleaning means) with a housing 117 provided with an attachment rail 116 and an opening 118 for exposure, and is made into a cartridge. In FIG. 2, 109 represents an exposure device (an example of an electrostatic charge image forming means), 112 represents a transfer device (an example of a transfer means), 115 represents a fixing device (an example of a fixing means), and 300 represents a recording paper (an example of a recording medium).

[0169] Next, the toner cartridge according to the present embodiment will be described. The toner cartridge according to the present embodiment is a toner cartridge that houses the green toner according to the present embodiment and is detachable from an image forming apparatus. The toner cartridge houses replenishing toner for supplying to developing means provided in the image forming apparatus.

[0170] The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8P, 8M, 8C, 8G, and 8K are detachable. Developing devices 4Y, 4P, 4M, 4C, 4G, and 4K are connected to toner cartridges corresponding to respective colors by toner supply pipes (not shown). When the amount of toner housed in the toner cartridge becomes small, the toner cartridge is replaced. An example of the toner cartridge according to the present embodiment is the toner cartridge 8G, in which the green toner according to the present embodiment is housed. Toner cartridges 8P, 8Y, 8M, 8C, and 8K house pink, yellow, magenta, cyan, and black toners, respectively.

Example

[0171] Hereinafter, embodiments of the invention will be described in detail by way of examples, but the embodiments of the invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are based on mass. Synthesis, processing, manufacturing, etc. were carried out at room temperature (25°C ± 3°C) unless otherwise specified.

[0172] <Production of Carrier> · Cyclohexyl methacrylate resin (weight average molecular weight 50,000): 54 parts · Carbon black (Cabot, VXC72): 6 parts · Toluene: 250 parts · Isopropyl alcohol: 50 parts The above materials and glass beads (diameter 1 mm, the same amount as toluene) were put into a sand mill and stirred at a rotational speed of 190 rpm for 30 minutes to obtain a coating agent.

[0173] 1000 parts of ferrite particles (volume average particle diameter 35 μm) and 150 parts of the coating agent were put into a kneader and mixed at room temperature (25 °C) for 20 minutes. Then, it was heated to 70 °C and dried under reduced pressure. The dried product was cooled to room temperature (25 °C), the dried product was taken out from the kneader, and sieved with a mesh having an opening of 75 μm to remove coarse powder, thereby obtaining a carrier.

[0174] <Preparation of oil-treated silica particles> [Oil-treated silica particles (1)] SiCl 4 , hydrogen gas and oxygen gas were mixed in the mixing chamber of a combustion burner and then burned at a temperature of 1000 °C to 3000 °C. Silica powder was taken out from the burned gas to obtain silica particles. At this time, by setting the molar ratio of hydrogen gas to oxygen gas to 1.35:1, silica particles (1) having an average primary particle diameter of 100 nm were obtained.

[0175] 100 parts of silica particles (1) and 500 parts of ethanol were put into an evaporator and stirred for 15 minutes while maintaining the temperature at 40 °C. Then, 10 parts of dimethyl silicone oil was added and stirred for 15 minutes, and further 15 parts of dimethyl silicone oil was added and stirred for 15 minutes. Then, the temperature was raised to 90 °C and ethanol was dried under reduced pressure, and further vacuum dried at 120 °C for 30 minutes. Thus, oil-treated silica particles (1) were obtained.

[0176] [Oil-treated silica particles (2)] In the same manner as silica particles (1), however, by changing the molar ratio of hydrogen gas to oxygen gas to 1.55:1, silica particles (2) having an average primary particle diameter of 20 nm were obtained. The same treatment as that of oil-treated silica particles (1) was performed on silica particles (2) to obtain oil-treated silica particles (2).

[0177] [Oil-treated silica particles (3)] In the same manner as for the silica particles (1), except that the molar ratio of hydrogen gas to oxygen gas was changed to 1.28:1, silica particles (3) with an average primary particle size of 195 nm were obtained. The same treatment as for the oil-treated silica particles (1) was performed on the silica particles (3) to obtain oil-treated silica particles (3).

[0178] [Oil-treated silica particles (4)] 100 parts of silica particles (1) and 500 parts of ethanol were placed in an evaporator and stirred for 15 minutes while maintaining the temperature at 40°C. Next, 5 parts of dimethyl silicone oil were added and stirred for 15 minutes, and then another 5 parts of dimethyl silicone oil were added and stirred for 15 minutes. Then, the temperature was raised to 90°C and the ethanol was dried under reduced pressure, and further vacuum dried at 120°C for 30 minutes. Thus, oil-treated silica particles (4) were obtained.

[0179] [Oil-treated silica particles (5)] 100 parts of silica particles (1) and 500 parts of ethanol were placed in an evaporator and stirred for 15 minutes while maintaining the temperature at 40°C. Next, 15 parts of dimethyl silicone oil were added and stirred for 15 minutes, and then another 25 parts of dimethyl silicone oil were added and stirred for 15 minutes. Then, the temperature was raised to 90°C and the ethanol was dried under reduced pressure, and further vacuum dried at 120°C for 30 minutes. Thus, oil-treated silica particles (5) were obtained.

[0180] <Example 1: Green toner and green developer> [Preparation of resin particle dispersion (1)] · Terephthalic acid: 30 mol parts · Fumaric acid: 70 mol parts · Bisphenol A ethylene oxide adduct: 5 mol parts · Bisphenol A propylene oxide adduct: 95 mol parts Charge the above materials into a flask equipped with a stirring device, a nitrogen inlet tube, a temperature sensor, and a rectification column. Raise the temperature to 220 °C over 1 hour, and after confirming that the reaction system is uniformly stirred, add 1 part of titanium tetraethoxide to 100 parts of the above materials. Raise the temperature to 230 °C over 30 minutes while distilling off the generated water. Continue stirring at 230 °C for 1 hour, and then cool the reaction system to room temperature. Thus, an amorphous polyester resin (weight average molecular weight 18,000, glass transition temperature 60 °C) was obtained. After charging 40 parts of ethyl acetate and 25 parts of 2-butanol into a reaction vessel equipped with a temperature control means and a nitrogen replacement means and mixing them, 100 parts of the amorphous polyester resin was gradually added and dissolved. Next, 3 molar equivalents of a 10% aqueous ammonia solution were added to the acid value of the amorphous polyester resin and stirred for 30 minutes. Next, the inside of the reaction vessel was replaced with dry nitrogen, and while maintaining the temperature at 40 °C and stirring, 400 parts of ion-exchanged water was dropped at a rate of 2 parts / minute to prepare a resin particle dispersion. The resin particle dispersion was cooled to room temperature and bubbled with dry nitrogen for 48 hours while stirring to remove ethyl acetate and 2-butanol to 1000 ppm or less. Ion-exchanged water was added to the resin particle dispersion to obtain a resin particle dispersion (1) with a solid content of 20%.

[0181] [Preparation of release agent particle dispersion (1)] · Paraffin wax (HNP-9, Nippon Seiro Co., Ltd.): 100 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 1 part · Ion-exchanged water: 350 parts Mix the above materials, heat to 100 °C, disperse with a homogenizer (Ultra Turrax T50, IKA), and then disperse with a pressure discharge type homogenizer (Gorin). Recover when the volume average particle diameter reaches 200 nm to obtain a release agent particle dispersion (1) with a solid content of 20%.

[0182] [Preparation of pigment dispersion (Y101)] · C.I. Pigment Yellow 101: 70 parts · Anionic surfactant (Neogen RK, DAI-ICHI KOGYO SEIYAKU CO., LTD.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume average particle size of 300 nm using a continuous kneader mill (KMC-3, INOUE MANUFACTURING CO., LTD.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (Y101).

[0183] [Preparation of Pigment Dispersion (PG36)] · C.I. Pigment Green 36: 70 parts · Anionic surfactant (Neogen RK, DAI-ICHI KOGYO SEIYAKU CO., LTD.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume average particle size of 150 nm using a continuous kneader mill (KMC-3, INOUE MANUFACTURING CO., LTD.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (PG36).

[0184] [Preparation of Green Toner Particles] · Resin particle dispersion (1): 560 parts (solid content 20%) · Release agent particle dispersion (1): 30 parts (solid content 20%) · Pigment dispersion (Y101): 70 parts (solid content 20%) · Pigment dispersion (PG36): 30 parts (solid content 20%) · Anionic surfactant (Neogen RK, DAI-ICHI KOGYO SEIYAKU CO., LTD.): 12 parts (solid content 20%) The above-mentioned materials were put into a round stainless steel flask, 0.1 mol / L nitric acid was added to adjust the pH to 3.5, and 30 parts of nitric acid with a polyaluminum chloride concentration of 10% was added. The liquid temperature was adjusted to 30 °C, and dispersion treatment was carried out using a homogenizer (Ultra Turrax T50, IKA), and while stirring the inside of the flask, it was heated to 45 °C with an oil bath for heating and held for 30 minutes. Next, 50 parts of the resin particle dispersion liquid (1) (solid content 20%) was added, and after holding for 1 hour, the pH was adjusted to 8.5 using a 0.1 mol / L aqueous sodium hydroxide solution, and while continuing stirring, it was heated to 84 °C and held for 2.5 hours. Then, it was cooled to room temperature at a rate of 20 °C / min, subjected to solid-liquid separation, and thoroughly washed with ion-exchanged water. The solid content was vacuum dried to obtain green toner particles (1). The volume average particle diameter of the green toner particles (1) was 5.8 μm.

[0185] [Preparation of Green Toner and Green Developer] 100 parts of green toner particles (1), 2.0 parts of oil-treated silica particles (1), and 1.0 part of hydrophobic titanium oxide particles (T805, Nippon Aerosil Co., Ltd.) were put into a sample mill and mixed at a rotational speed of 10,000 rpm for 30 seconds. Then, it was sieved with a vibrating sieve having a mesh opening of 45 μm to obtain externally added toner. 10 parts of the externally added toner and 100 parts of the carrier were put into a V blender and stirred for 20 minutes. Then, it was sieved with a sieve having a mesh opening of 212 μm to obtain a green developer.

[0186] <Examples 2 - 3> In the same manner as in Example 1, however, in the preparation of the green toner particles, the amount of the pigment dispersion liquid used was changed to produce green toner particles, green toner, and green developer.

[0187] <Example 4> In the same manner as in Example 1, however, in the preparation of the green toner particles, C.I. Pigment Green 36 was replaced with C.I. Pigment Green 59 to produce green toner particles, green toner, and green developer.

[0188] <Comparative Example 1> In the same manner as in Example 1, except that 2.0 parts of oil-treated silica particles (1) were replaced with 2.0 parts of silica particles (1), green toner particles, green toner, and a green developer were produced.

[0189] <Comparative Example 2> In the same manner as in Example 1, except that no oil-treated silica particles (1) were externally added, green toner particles, green toner, and a green developer were produced.

[0190] <Comparative Examples 3 to 4> In the same manner as in Example 1, except that in the preparation of the green toner particles, the amount of the pigment dispersion used was changed, and no oil-treated silica particles (1) were externally added, green toner particles, green toner, and a green developer were produced.

[0191] <Comparative Examples 5 to 7> In the same manner as in Example 1, except that in the preparation of the green toner particles, the amount of the pigment dispersion used was changed, and green toner particles, green toner, and a green developer were produced.

[0192] <Example 5> In the same manner as in Example 1, except that when mixing the green toner particles and the external additive, the rotational speed of the sample mill was changed to 15,000 rpm, and green toner particles, green toner, and a green developer were produced.

[0193] <Example 6> In the same manner as in Example 1, except that when mixing the green toner particles and the external additive, the rotational speed of the sample mill was changed to 5,000 rpm, and green toner particles, green toner, and a green developer were produced.

[0194] <Examples 7 to 8> In the same manner as in Example 1, except that the type and the externally added amount of the oil-treated silica particles were changed to the specifications shown in Table 1, and green toner particles, green toner, and a green developer were produced.

[0195] <Examples 9 - 10> In the same manner as in Example 1, except that the type of oil-treated silica particles was changed to the specifications described in Table 1, green toner particles, green toner, and a green developer were produced.

[0196] <Examples 11 - 15> In the same manner as in Example 1, except that the particle size of the fluorescent pigment and / or the particle size of the non-fluorescent pigment was changed to the specifications described in Table 1, green toner particles, green toner, and a green developer were produced. The particle size of the pigment was controlled by the treatment time of the continuous jet mill when preparing the pigment dispersion.

[0197] <Comparative Examples 8 - 10> In the same manner as in Example 1, except that the particle size of the fluorescent pigment and / or the particle size of the non-fluorescent pigment was changed to the specifications described in Table 1, and without externally adding oil-treated silica particles (1), green toner particles, green toner, and a green developer were produced. The particle size of the pigment was controlled by the treatment time of the continuous jet mill when preparing the pigment dispersion. In Comparative Example 10, 2.0 parts of oil-treated silica particles (1) were replaced with 2.0 parts of silica particles (1).

[0198] <Performance Evaluation> [Color difference ΔE from the color sample] A modified machine of DocuCentre Color 400CP (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing device, and the toner was put into the toner cartridge. In an environment of a temperature of 25°C and a relative humidity of 60%, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Film Business Innovation Co., Ltd.), a solid green image (concentration 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ) was formed. The fixing temperature was set to 180°C. Using a reflection spectrophotometer X-Rite 939 (aperture diameter 4 mm, X-Rite Co., Ltd.), at 10 locations within the solid image, CIE1976L * a * b * in the color system* Value, a * Values and b * Measured the values and L * Value, a * Values and b * Calculated the average value of the values. 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.

[0199]

Equation

[0200] [Reflectance] Prepared a modified machine of DocuCentreColor400CP (Fuji Xerox Business Innovation Co., Ltd.), put the developer into the developing unit, and put the toner into the toner cartridge. In an environment of a temperature of 25°C and a relative humidity of 60%, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Xerox Business Innovation Co., Ltd.), a solid green image (density 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ) was formed. Using a reflection spectrophotometer X-Rite 939 (aperture diameter 4 mm, X-Rite Co., Ltd.), the spectral reflectance (measurement wavelength range 400 nm to 700 nm) was measured at 10 locations in the solid image. The average value of the reflectance at the reflection peak was calculated and classified as follows. A: The reflectance at the reflection peak is 80% or more B: The reflectance at the reflection peak is 70% or more and less than 80% C: The reflectance at the reflection peak is less than 70%

[0201] [fogging] A modified machine of DocuCentre Color 400 CP (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing unit, and the toner was put into the toner cartridge. After leaving the image forming apparatus in an environment of a temperature of 28°C and a relative humidity of 85% for one day, in the same environment, 100,000 sheets of images with a density of 40% were output onto A4 plain paper. Using a reflection spectrophotometer X-Rite 938 (X-Rite Co., Ltd.), the density at locations where fogging is likely to occur (one location per sheet) in the last 10 non-image areas was measured, and the density difference ΔE between the darkest density among them and the density of the plain paper was calculated. The density difference ΔE was classified as follows. G1: The density difference ΔE is less than 0.1 G2: The density difference ΔE is 0.1 or more and less than 0.2 G3: The density difference ΔE is 0.2 or more and less than 0.3 G4: The density difference ΔE is 0.3 or more

[0202] [offset fixing] A modified machine of DocuCentre Color 400 CP (Fuji Film Business Innovation Co., Ltd.) was prepared, the developer was put into the developing unit, and the toner was put into the toner cartridge. The fixing device removed from ApeosPort IV C3370 (Fuji Film Business Innovation Co., Ltd.) was modified to produce a fixing device capable of arbitrarily setting the fixing temperature. In an environment with a temperature of 25°C and a relative humidity of 60%, a solid green image (concentration 100%, size 5 cm × 5 cm, toner loading 4.5 g / m 2 ) of an unfixed image was formed on a film synthetic paper (Yupo paper, Yupo Corporation) and passed through a fixing device. The nip width of the fixing device was 6 mm, the nip thickness was 1.6 kgf / cm 2 , the process speed was 175 mm / sec, and the fixing temperature was set at intervals of 5°C from 160°C to 220°C. The fixed image was visually observed to confirm the presence or absence of offset (the phenomenon where the toner image adheres to the fixing member and peels off from the recording medium). Based on the lowest temperature at which offset occurred, the classification was as follows. A: No offset occurs, or the offset occurrence temperature is 200°C or higher B: The offset occurrence temperature is 170°C or higher and less than 200°C C: The offset occurrence temperature is less than 170°C

[0203] The symbols in Table 1 represent the following pigments. · PY101: C.I. Pigment Yellow 101 (Radiant Color, Radglo VSF-0-01, emission peak 520 nm), one type of azomethine fluorescent pigment (Y) · PG36: C.I. Pigment Green 36 (Toyota Color Co., Ltd., LIONOL GREEN 8624, reflection peak 510 nm), one type of pigment (G) · PG59: C.I. Pigment Green 59 (DIC Corporation, FASTOGEN GREEN C100, reflection peak 520 nm), one type of pigment (G)

[0204]

Table 1

[0205] <Image formation by actual machine> An electrophotographic and intermediate transfer type 6 - tandem type image forming apparatus was prepared. Each of the six developing devices was filled with a pink developer, a yellow developer, a magenta developer, a cyan developer, a black developer, and a green developer (the developer of Example 1). Then, an image was formed on A4 - size coated paper based on the image data obtained by color - separating RGB data into the above six colors. An image with good color reproducibility close to the original RGB data was obtained.

[0206] The green toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method of the present disclosure include the following aspects.

[0207] ((1)) It contains a binder resin, an azomethine fluorescent pigment having an emission peak in the region of a wavelength of 500 nm or more and 550 nm or less in the emission spectrum, and a non - fluorescent pigment having a reflection peak in the region of a wavelength of 480 nm or more and 540 nm or less in the reflection spectrum. The mass ratio of the azomethine fluorescent pigment in the green toner particles is 3% by mass or more and 10% by mass or less. The mass - based ratio M1 / M2 of the content M1 of the azomethine fluorescent pigment and the content M2 of the non - fluorescent pigment is 1 or more and 5 or less. Green toner particles and oil - treated silica particles externally added to the green toner particles. A green toner for electrostatic charge image development. ((2)) The oil - treated silica particles are oil - treated silica particles having a free oil amount of 5% by mass or more and 30% by mass or less. The green toner for electrostatic charge image development according to ((1)). ((3)) When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the oil - treated silica particles detached from the green toner particles are 20% by mass or more and 40% by mass or less of the oil - treated silica particles externally added to the green toner particles. The green toner for electrostatic charge image development according to ((1)) or ((2)). (((4))) The average primary particle diameter of the oil-treated silica particles is 15 nm or more and 200 nm or less, The green toner for electrostatic charge image development according to any one of ((1)) to ((3)). (((5))) The oil-treated silica particles are silicone oil-treated silica particles, The green toner for electrostatic charge image development according to any one of ((1)) to ((4)). (((6))) The green toner contains 0.5 parts by mass or more and 5 parts by mass or less of the oil-treated silica particles with respect to 100 parts by mass of the green toner particles, The green toner for electrostatic charge image development according to any one of ((1)) to ((5)). (((7))) The volume average particle diameter D1 of the azomethine fluorescent pigment is 30 nm or more and 800 nm or less, The volume average particle diameter D1 of the azomethine fluorescent pigment and the volume average particle diameter D2 of the non-fluorescent pigment satisfy the relationship D1 > D2, The green toner for electrostatic charge image development according to any one of ((1)) to ((6)). (((8))) The azomethine fluorescent pigment is C.I. Pigment Yellow 101, The green toner for electrostatic charge image development according to any one of ((1)) to ((7)). (((9))) The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment Green 58, C.I. Pigment Green 59 and C.I. Pigment Blue 76, The green toner for electrostatic charge image development according to any one of ((1)) to ((8)).

[0208] (((10))) An electrophotographic developer containing the green toner for electrostatic charge image development according to any one of ((1)) to ((9)). (((11))) A toner cartridge that houses the green toner for electrostatic charge image development according to any one of ((1)) to ((9)) and is detachable from an image forming apparatus. (((12))) A process cartridge that houses the electrophotographic developer according to ((10)) and includes developing means for developing an electrostatic charge image formed on the surface of an image carrier as a toner image with the electrophotographic developer. A process cartridge detachable from an image forming apparatus. (((13))) An image carrier Charging means for charging the surface of the image carrier Electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the image carrier Developing means for housing the electrophotographic developer according to ((10)) and developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrophotographic developer Transferring means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium Fixing means for fixing the toner image transferred to the surface of the recording medium An image forming apparatus comprising the above. (((14))) A charging step of charging the surface of an image carrier An electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrophotographic developer according to ((10)) A transferring step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium A fixing step of fixing the toner image transferred to the surface of the recording medium An image forming method having the above steps. (((15))) An electrophotographic image forming apparatus including first to sixth image forming units for forming images of respective colors of pink, yellow, magenta, cyan, black, and green. The image forming unit for forming the green image contains the electrostatic charge image developer described in (((10))). Image forming apparatus. (((16))) An electrophotographic image forming method including first to sixth image forming steps for forming images of respective colors of pink, yellow, magenta, cyan, black, and green. The image forming step for forming the green image uses the electrostatic charge image developer described in (((10))). Image forming method.

[0209] (((1))), (((5))), (((8))), or (((9))) provides a green toner for electrostatic charge image development that is less likely to cause fogging compared to a green toner for electrostatic charge image development to which oil-treated silica particles are not externally added. (((2))) provides a green toner for electrostatic charge image development that is less likely to cause fogging compared to a green toner for electrostatic charge image development in which the free oil amount of oil-treated silica particles is less than 5% by mass. (((3))) provides a green toner for electrostatic charge image development that is less likely to cause fogging compared to a green toner for electrostatic charge image development in which the amount of oil-treated silica particles detached from the green toner particles is less than 20% by mass. (((4))) provides a green toner for electrostatic charge image development that is less likely to cause fogging compared to a green toner for electrostatic charge image development in which the average primary particle diameter of the oil-treated silica particles is less than 15 nm. (((6))) provides a green toner for electrostatic charge image development that is less likely to cause fogging compared to a green toner for electrostatic charge image development in which the externally added amount of the oil-treated silica particles is less than 0.5 part by mass. According to ((7)), compared with a green toner for electrostatic charge image development containing green toner particles in which the volume average particle diameter D1 of the azomethine fluorescent pigment is less than 30 nm or more than 800 nm, or green toner particles in which the volume average particle diameter D1 of the azomethine fluorescent pigment and the volume average particle diameter D2 of the non-fluorescent pigment satisfy D1 < D2, a green toner for electrostatic charge image development in which fixing offset is less likely to occur is provided.

[0210] According to ((10)), compared with a case where oil-treated silica particles are not externally added to a green toner for electrostatic charge image development, an electrostatic charge image developer in which fogging is less likely to occur is provided. According to ((11)), compared with a case where oil-treated silica particles are not externally added to a green toner for electrostatic charge image development, a toner cartridge in which fogging is less likely to occur is provided. According to ((12)), compared with a case where oil-treated silica particles are not externally added to a green toner for electrostatic charge image development, a process cartridge in which fogging is less likely to occur is provided. According to ((13)) or ((15)), compared with a case where oil-treated silica particles are not externally added to a green toner for electrostatic charge image development, an image forming apparatus in which fogging is less likely to occur is provided. According to ((14)) or ((16)), compared with a case where oil-treated silica particles are not externally added to a green toner for electrostatic charge image development, an image forming method in which fogging is less likely to occur is provided.

Description of Signs

[0211] 1P, 1Y, 1M, 1C, 1K, 1G Photoconductor (an example of an image holding member) 2P, 2Y, 2M, 2C, 2K, 2G Charging roll (an example of a charging means) 3P, 3Y, 3M, 3C, 3K, 3G Exposure device (an example of an electrostatic charge image forming means) 4P, 4Y, 4M, 4C, 4K, 4G Developing device (an example of a developing means) 5P, 5Y, 5M, 5C, 5K, 5G Primary transfer roll (an example of a primary transfer means) 6P, 6Y, 6M, 6C, 6K, 6G Photoconductor Cleaning Device (An Example of Cleaning Means) 8P, 8Y, 8M, 8C, 8K, 8G Toner Cartridge 10P, 10Y, 10M, 10C, 10K, 10G Image Forming Unit 20 Intermediate Transfer Belt (An Example of Intermediate Transfer Member) 21 Intermediate Transfer Member Cleaning Device 22 Driving Roll 23 Supporting Roll 24 Opposing Roll 26 Secondary Transfer Roll (An Example of Secondary Transfer Means) 28 Fixing Device (An Example of Fixing Means) P Recording Paper (An Example of Recording Medium)

[0212] 107 Photoconductor (An Example of Image Holding Member) 108 Charging Roll (An Example of Charging Means) 109 Exposure Device (An Example of Electrostatic Charge Image Forming Means) 111 Developing Device (An Example of Developing Means) 112 Transfer Device (An Example of Transfer Means) 113 Photoconductor Cleaning Device (An Example of Cleaning Means) 115 Fixing Device (An Example of Fixing Means) 116 Mounting Rail 117 Housing 118 Opening for Exposure 200 Process Cartridge 300 Recording Paper (An Example of Recording Medium)

Claims

1. A green toner comprising a binder resin, an azomethine fluorescent pigment having an emission peak in a region where the wavelength of the emission spectrum is 500 nm or more and 550 nm or less, and a non-fluorescent pigment having a reflection peak in a region where the wavelength of the reflection spectrum is 480 nm or more and 540 nm or less, wherein the mass ratio of the azomethine fluorescent pigment in the green toner particles is 3% by mass or more and 10% by mass or less, and the mass ratio M1 / M2 of the content M1 of the azomethine fluorescent pigment to the content M2 of the non-fluorescent pigment is 1 or more and 5 or less, green toner particles, and oil-treated silica particles externally added to the green toner particles. A green toner for electrostatic charge image development.

2. The oil-treated silica particles are oil-treated silica particles having a free oil amount of 5% by mass or more and 30% by mass or less, The green toner for electrostatic charge image development according to Claim 1.

3. When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the oil-treated silica particles detached from the green toner particles are 20% by mass or more and 40% by mass or less of the oil-treated silica particles externally added to the green toner particles, The green toner for electrostatic charge image development according to Claim 1.

4. The average primary particle diameter of the oil-treated silica particles is 15 nm or more and 200 nm or less, The green toner for electrostatic charge image development according to Claim 1.

5. The oil-treated silica particles are silicone oil-treated silica particles, The green toner for electrostatic charge image development according to Claim 1.

6. The green toner contains 0.5 parts by mass or more and 5 parts by mass or less of the oil-treated silica particles with respect to 100 parts by mass of the green toner particles, The green toner for electrostatic charge image development according to Claim 1.

7. The volume average particle diameter D1 of the azomethine fluorescent pigment is 30 nm or more and 800 nm or less, and the volume average particle diameter D1 of the azomethine fluorescent pigment and the volume average particle diameter D2 of the non-fluorescent pigment satisfy the relationship D1 > D2, The green toner for electrostatic charge image development according to Claim 1.

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

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

10. An electrostatic charge image developer containing the green toner for electrostatic charge image development according to any one of claims 1 to 9.

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

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

13. An image carrier, a charging unit that charges the surface of the image carrier, an electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image carrier, a developing unit that houses the electrostatic charge image developer according to claim 10 and develops an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, a transfer unit that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, a fixing unit that fixes the toner image transferred to the surface of the recording medium, and an image forming apparatus including the above components.

14. A charging step of charging the surface of an image carrier, an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier, a developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 10, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, a fixing step of fixing the toner image transferred to the surface of the recording medium, and an image forming method including the above steps.

15. An electrophotographic image forming apparatus including first to sixth image forming units for forming images of respective colors of pink, yellow, magenta, cyan, black, and green, wherein the image forming unit for forming the green image houses the electrostatic charge image developer according to claim 10. An image forming apparatus.

16. An electrophotographic image forming method including first to sixth image forming steps for forming images of respective colors of pink, yellow, magenta, cyan, black, and green. An image forming step of forming the green image uses the electrostatic charge image developer according to claim 10, Image forming method.

Images