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

Abstract

To provide a green toner for electrostatic charge image development that reduces the generation of color stripes in an image.SOLUTION: A green toner for electrostatic charge image development includes a green toner particle and a lubricant 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 coated article 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 the fluorescent dye and the resin binder that does not contain the copper phthalocyanine pigment 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 on a mass basis 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 a developer containing a toner to which fine particles having a volume average particle diameter of 80 to 300 nm, an abrasive, and a lubricant are externally added. When the volume average particle diameters of the fine particles, the abrasive, and the toner are A, B, and C, respectively, a developer satisfying the relationship A < B < C is disclosed.

[0007] Patent Document 6 discloses an electrostatic charge image developing toner containing a binder resin, a wax, and a colorant, in which silica particles, abrasive particles, and wax particles are externally added to the toner surface.

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

[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 the green toner, a toner containing a yellow fluorescent dye (for example, C.I. Solvent Green 5) and a green pigment or a blue pigment is known. However, since fluorescent dyes generally exhibit concentration quenching in which luminescence decays as the concentration increases, it is difficult to reproduce colors with higher brightness and higher chroma 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 has been promoted. From the viewpoint of enhancing the brightness and chroma of a green image, it is preferable that the dispersion particle diameter of the fluorescent pigment in the green toner particles be large. However, when the dispersion particle diameter of the fluorescent pigment is large, the filler effect weakens, and the mechanical strength of the green toner particles decreases. When the mechanical strength of the toner particles decreases, the toner particles crack and generate small-diameter toner. The small-diameter toner is difficult to transfer and may form a film on the surface of the image carrier. In addition, the small-diameter toner is difficult to transfer, accumulates on the cleaning blade of the image carrier, is taken into the external addition dam, and may make the external addition dam brittle and break. Additionally, the pigment exposed on the small-diameter toner may excessively wear the surface of the image carrier. All of these may lead to the occurrence of color streaks in the image.

[0012] The present disclosure has been made under the above circumstances. An object of the present disclosure is to provide a green toner for electrostatic charge image development that is less likely to generate color streaks compared to a green toner for electrostatic charge image development to which no lubricant is externally added.

Means for Solving the Problem

[0013] The means for solving the above problem include the following aspects. <1> Containing a binder resin, an azomethine fluorescent pigment having an emission peak in the region of 500 nm or more and 550 nm or less in the emission spectrum, and a non-fluorescent pigment having a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum, 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 to the content M2 of the non-fluorescent pigment is 1 or more and 5 or less, Green toner particles, Including a lubricant externally added to the green toner particles, A green toner for electrostatic charge image development. <2> Containing 0.02 parts by mass or more and 5.0 parts by mass or less of the lubricant with respect to 100 parts by mass of the green toner particles, The green toner for electrostatic charge image development according to <1>. <3> The lubricant contains fatty acid metal salt particles, The green toner for electrostatic charge image development according to <1> or <2>. <4> When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the fatty acid metal salt particles detached from the green toner particles are 10% by mass or more and 30% by mass or less of the fatty acid metal salt particles externally added to the green toner particles, The green toner for electrostatic charge image development according to <3>. <5> Furthermore, including resin particles externally added to the green toner particles, The green toner for electrostatic charge image development according to any one of <1> to <4>. <6> Furthermore, it contains titanate compound particles externally added to the green toner particles, The green toner for electrostatic charge image development according to any one of <1> to <5>. <7> Furthermore, it contains resin particles and titanate compound particles externally added to the green toner particles, The green toner for electrostatic charge image development according to any one of <1> to <4>. <8> 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 <7>. <9> 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 <8>. <10> The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 36, C.I. Pigment Green 7, 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 <9>.

[0014] <11> An electrostatic charge image developer containing the green toner for electrostatic charge image development according to any one of <1> to <10>. <12> A toner cartridge that houses the green toner for electrostatic charge image development according to any one of <1> to <10> and is detachable from an image forming apparatus. <13> It houses the electrostatic charge image developer according to <11>, and includes developing means for developing 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. <14> An image holding member, charging means for charging the surface of the image holding member, electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the image holding member, developing means for accommodating the electrostatic charge developer according to <11> and developing the electrostatic charge image formed on the surface of the image holding member as a toner image with the electrostatic charge developer, transfer means for transferring the toner image formed on the surface of the image holding member 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. <15> A charging step of charging the surface of the image holding member, an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image holding member, a developing step of developing the electrostatic charge image formed on the surface of the image holding member as a toner image with the electrostatic charge developer according to <11>, a transfer step of transferring the toner image formed on the surface of the image holding member 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. <16> An image forming apparatus comprising first to sixth electrophotographic 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 according to <11>. Image forming apparatus. <17> An image forming method having first to sixth electrophotographic 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 according to <11>. Image forming method.

Advantages of the Invention

[0015] According to <1>, <3>, <9> or <10>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner to which no lubricant is externally added. According to <2>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner having an externally added amount of lubricant of less than 0.02 parts by mass. According to <4>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner having fatty acid metal salt particles desorbing from the green toner particles of less than 10% by mass. According to <5>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner to which no resin particles are externally added. According to <6>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner to which no titanate compound particles are externally added. According to <7>, there is provided an electrostatic charge image developing green toner in which color streaks are less likely to occur as compared with an electrostatic charge image developing green toner to which no resin particles are externally added or an electrostatic charge image developing green toner to which no titanate compound particles are externally added. According to <8>, there is provided an electrostatic charge image developing green toner having excellent reflectance as compared with an electrostatic charge image developing green toner containing green toner particles in which the volume average particle diameter D1 of an 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 an azomethine fluorescent pigment and the volume average particle diameter D2 of a non-fluorescent pigment satisfy D1 < D2.

[0016] According to <11>, there is provided an electrostatic charge image developer in which color streaks are less likely to occur as compared with a case where no lubricant is externally added to an electrostatic charge image developing green toner. According to <12>, there is provided a toner cartridge in which color streaks are less likely to occur as compared with a case where no lubricant is externally added to an electrostatic charge image developing green toner. According to <13>, a process cartridge in which color streaks are less likely to occur is provided as compared with the case where no lubricant is externally added to the green toner for electrostatic charge image development. According to <14> or <16>, an image forming apparatus in which color streaks are less likely to occur is provided as compared with the case where no lubricant is externally added to the green toner for electrostatic charge image development. According to <15> or <17>, an image forming method in which color streaks are less likely to occur is provided as compared with the case where no lubricant is externally added to the green toner for electrostatic charge image development.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Mode 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 by using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described 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 an independent step but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0022] When an embodiment is described with reference to the drawings in the present disclosure, the configuration of the embodiment 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, unless otherwise specified, the particle diameter of each component means a value for the mixture of the plurality of types of particles present in the composition.

[0024] In the present disclosure, when a compound is represented by a structural formula, 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 a hydrocarbon chain are omitted.

[0025] In the present disclosure, “(meth)acryl” is an expression that includes both acryl and methacryl, 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 refers to a pigment that emits light by external light energy, and the non-fluorescent pigment refers to 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 include 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 the present embodiment and the reflection peak of the pigment (G) having the largest content among the pigments (G) contained in the green toner particles is preferably 40 nm or less. The smaller the wavelength difference between the emission peak and the reflection peak, the more preferable it is. More preferably, it is 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 the present 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 emission peak and the reflection peak, the more preferable it is. More preferably, it is 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 the present 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 be 13.5 or less. The smaller the color difference ΔE, the more preferable it is, 10 or less is more preferable, 6.5 or less is still more preferable, 3 or less is still more preferable, 1 or less is still more preferable, and 0 is ideal.

[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, and are the values 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 the image formed by the green toner, the color difference ΔE is 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 the sample with a carrier, put it into the developing device of the image forming apparatus, and form a solid image (image with a density of 100%) on the coated paper at a fixing temperature of 180°C and a toner loading of 4.0 g / m 2 The CIE1976L of the formed solid image * 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 a lubricant externally added to the green toner particles. The lubricant is preferably in the form of particle shape (i.e., lubricant particles). From the viewpoint of enhancing the lightness and chroma of the green image, it is preferable that the dispersion particle diameter of the fluorescent pigment in the green toner particles is relatively large. However, this may result in relatively low mechanical strength of the green toner particles and easy generation of small-diameter toner. Small-diameter toner is difficult to be transferred and may film on the surface of the image carrier. Also, the pigment exposed on the small-diameter toner may excessively wear the surface of the image carrier. All of these may lead to the occurrence of color streaks in the image. In contrast, the green toner according to the present embodiment contains a lubricant as an external additive, which makes it difficult to cause filming on the surface of the image carrier and excessive wear of the image carrier, and suppresses the occurrence of color streaks in the image.

[0044] Hereinafter, the configuration of the green toner according to the present 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 contain 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 the azomethine compound (1), the azomethine compound (2), and the azomethine compound (3).

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

[0053] From the viewpoint of achieving a good balance in the dispersibility in toner particles, the color developability on the recording medium, the 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 still 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 measuring device (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 is 50% is defined as the volume average particle diameter.

[0054] From the viewpoint of increasing the reflectance of the reflection peak in the spectral reflectance spectrum, the green toner according to this embodiment preferably has a volume average particle diameter D1 of the azomethine fluorescent pigment (Y) of 30 nm or more and 800 nm or less, and 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 still more preferably 250 nm or more and 400 nm or less.

[0055] - Pigment (G)- Pigment (G) has a reflection peak in the region of 480 nm or more and 540 nm or less in the reflection spectrum. The reflection peak of 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 Pigment (G) include halogenated phthalocyanine compounds and lake pigments of triphenylmethane dyes. As Pigment (G), halogenated phthalocyanine compounds are preferred.

[0057] As 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 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 zinc halogenated phthalocyanine include C.I. Pigment Green 58 (reflection peak 515 nm) and C.I. Pigment Green 59 (reflection peak 520 nm).

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

[0059] From the viewpoint of achieving a good balance in the dispersibility in toner particles, color developability on a recording medium, fixability to the recording medium, etc., the volume average particle diameter D2 of 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 and scattering particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.). A particle size distribution based on volume is plotted 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.

[0060] From the viewpoint of increasing the reflectance of the reflection peak in the spectral reflectance spectrum, 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 viewpoint of increasing 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 still more preferably 1.5 or more and 2 or less.

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

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

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

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

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

[0066] Examples of the polyhydric alcohol include aliphatic diols (such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (such as cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), aromatic diols (such as ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferred, and more preferably aromatic diols. As the polyhydric alcohol, a polyhydric alcohol having a trivalent or higher valency that forms a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the polyhydric alcohol having a trivalent or higher valency include glycerin, trimethylolpropane, 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 5000 or more and 1000000 or less, more preferably 7000 or more and 500000 or less. The number average molecular weight (Mn) of the polyester resin is preferably 2000 or more and 100000 or less. The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or more and 100 or less, more preferably 2 or more and 60 or less. The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out using Tosoh's GPC·HLC-8120GPC as the measuring device, Tosoh's column·TSKgel SuperHM-M (15 cm), and THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using the molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

[0069] The polyester resin is obtained by a known production method. Specifically, for example, it is obtained by a method in which the polymerization temperature is 180°C or higher and 230°C or lower, the inside of the reaction system is depressurized as necessary, and the reaction is carried out while removing water or alcohol generated during condensation. When the monomer of the raw material is not dissolved 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 the polycondensation with the main component.

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

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

[0072] The melting temperature of the release agent is preferably 50°C or more and 110°C or less, and more preferably 60°C or more and 100°C or less. The melting temperature is determined by the "melting peak temperature" described in the method for determining the melting temperature in 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 4% by mass or more and 15% by mass or less, based on the total toner particles.

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

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

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

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

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

[0079] The average circularity of the toner particles is 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 determined by a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation). 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] [Lubricant] Examples of the lubricant include fatty acid metal salt particles and layered structure compound particles. From the viewpoint of excellent effect of suppressing the occurrence of color streaks, fatty acid metal salt particles are preferred.

[0081] Examples of the fatty acid metal salt include stearic acid metal salts and lauric acid metal salts. Examples of the stearic acid metal salt include zinc stearate, calcium stearate, barium stearate, magnesium stearate, aluminum stearate, lithium stearate, potassium stearate, and iron stearate. Examples of the lauric acid metal salt include zinc laurate, calcium laurate, barium laurate, magnesium laurate, aluminum laurate, lithium laurate, potassium laurate, and iron laurate. From the viewpoint of excellent effect of suppressing the occurrence of color streaks, fatty acid metal salt particles are preferred, and zinc stearate particles are more preferred.

[0082] The layered structure compound is a compound having a laminated structure with an interlayer distance on the order of angstroms, and it is considered to exhibit a lubricating action by the layers shifting relative to each other. Examples of the layered structure compound include melamine cyanurate, boron nitride, graphite fluoride, molybdenum disulfide, and mica.

[0083] The volume average particle diameter of the lubricant particles is preferably 0.1 μm or more and 8 μm or less, more preferably 0.2 μm or more and 5 μm or less, and still more preferably 0.5 μm or more and 3 μm or less.

[0084] The method for obtaining the volume average particle diameter of the lubricant particles is as follows. Put 1 g of the green toner into a 1 L beaker, and add 500 g of a 5 mass% aqueous solution of a surfactant (sodium alkylbenzene sulfonate is preferred). Apply ultrasonic waves to desorb the external additive from the toner particles, perform centrifugation, and fractionate the lubricant particles by density. Add 2 ml of the fraction containing the lubricant particles to 100 ml to 150 ml of an electrolytic solution (manufactured by Beckman Coulter, ISOTON-II), and perform dispersion treatment with ultrasonic waves to obtain a measurement sample. Using a Coulter Multisizer II type (manufactured by Beckman Coulter, aperture diameter 100 μm), measure the particle diameters of 5,000 lubricant particles with a particle diameter of 60 μm or less, and take the particle diameter at which the cumulative value from the small diameter side reaches 50% in the volume-based particle size distribution as the volume average particle diameter.

[0085] The green toner according to the present embodiment is preferably such that 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 lubricant particles desorbed from the green toner particles are 10 mass% or more and 30 mass% or less of the lubricant particles externally added to the green toner particles. The mass ratio of the lubricant particles desorbed from the green toner particles by the above ultrasonic treatment is also referred to as the weak adhesion ratio of the lubricant particles.

[0086] When the weak adhesion ratio of the lubricant particles is 10 mass% or more, the lubricant particles easily migrate from the green toner particles to the surface of the image holding body, and the effect of suppressing color streaks is excellent. From this viewpoint, the weak adhesion ratio of the lubricant particles is more preferably 12 mass% or more, and still more preferably 15 mass% or more. When the weak adhesion ratio of the lubricant particles is 30 mass% or less, the amount of the lubricant particles migrating from the green toner particles to the surface of the image holding body is not too large, and it is less likely to cause filming. From this viewpoint, the weak adhesion ratio of the lubricant particles is more preferably 25 mass% or less, and still more preferably 20 mass% or less.

[0087] The green toner according to this embodiment contains fatty acid metal salt particles as a lubricant, and the green toner is dispersed in water containing a surfactant. When ultrasonic treatment is performed at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the fatty acid metal salt particles detached from the green toner particles are preferably 10% by mass or more and 30% by mass or less of the fatty acid metal salt particles externally added to the green toner particles. The mass ratio of the fatty acid metal salt particles detached from the green toner particles by the above ultrasonic treatment is also referred to as the weak adhesion ratio of the fatty acid metal salt particles.

[0088] When the weak adhesion ratio of the fatty acid metal salt particles is 10% by mass or more, the fatty acid metal salt particles easily migrate from the green toner particles to the surface of the image carrier, and the effect of suppressing color streaks is excellent. From this viewpoint, the weak adhesion ratio of the fatty acid metal salt particles is more preferably 12% by mass or more, and still more preferably 15% by mass or more. When the weak adhesion ratio of the fatty acid metal salt particles is 30% by mass or less, the amount of the fatty acid metal salt particles migrating from the green toner particles to the surface of the image carrier is not too large, and it is less likely to cause filming. From this viewpoint, the weak adhesion ratio of the fatty acid metal salt particles is more preferably 25% by mass or less, and still more preferably 20% by mass or less.

[0089] The method for obtaining the weak adhesion ratio of the fatty acid metal salt particles is as follows. The weak adhesion ratio of the lubricant particles and the weak adhesion ratio of the lubricant particles other than the fatty acid metal salt particles are also obtained in the same manner. 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. Pour 50 mL of the aqueous surfactant solution into a 100 mL glass beaker, add 4 g of the green toner thereto, and stir with a magnetic stirrer at a rotation speed of 100 rpm for 5 minutes to prepare a toner dispersion. Prepare two portions of this toner dispersion. Insert the probe of an ultrasonic homogenizer (VCX750, Sonic and Material) into one toner dispersion (insert it until the distance between the probe tip and the beaker bottom surface 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, fatty acid metal salt particles, and other external additives by density, and collect the fraction containing the fatty acid metal salt particles. Dry the fraction and measure the mass of the fatty acid metal salt particles. Let this mass (i.e., the mass of the fatty acid metal salt particles weakly adhering 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 probe tip and the beaker bottom surface 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 sufficient to detach all the fatty acid metal salt particles from the green toner particles. Centrifuge the toner dispersion to fractionate the green toner particles, fatty acid metal salt particles, and other external additives by density, and collect the fraction containing the fatty acid metal salt particles. Dry the fraction and measure the mass of the fatty acid metal salt particles. Let this mass (i.e., the total mass of the fatty acid metal salt particles externally added to the green toner) be S2. Let the value of S1 / S2×100 be the weak adhesion ratio (mass %) of the fatty acid metal salt particles.

[0090] The weak adhesion ratio of the fatty acid metal salt 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 fatty acid metal salt particles.

[0091] The externally added amount of the lubricant is preferably 0.02 parts by mass or more and 5.0 parts by mass or less, more preferably 0.04 parts by mass or more and 2.0 parts by mass or less, and still more preferably 0.08 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the green toner particles.

[0092] [Resin particles] From the perspective of suppressing the occurrence of color streaks in the image, the green toner according to this embodiment preferably contains resin particles as an external additive. Examples of the resin particles include acrylic resin particles, polystyrene resin particles, and melamine resin particles, and acrylic resin particles are preferred from the perspective of the mechanical strength of the particles.

[0093] As the (meth)acrylic acid alkyl ester constituting the acrylic resin particles, a (meth)acrylic acid alkyl ester having 1 to 6 carbon atoms in the alkyl group is preferred. Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and hexyl (meth)acrylate, and methyl (meth)acrylate is preferred.

[0094] From the perspective of uniformly coating the toner particle surface, the average primary particle size of the resin particles is preferably 10 nm or more and 500 nm or less, more preferably 20 nm or more and 400 nm or less, and even more preferably 30 nm or more and 300 nm or less.

[0095] The method for obtaining the average primary particle size of the resin 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 carbon element by EDX analysis, 200 resin particles are specified from within one field of view. The images of 200 resin particles are analyzed with image processing and analysis software WinRoof (Miyaya Shoko Co., Ltd.) to obtain the equivalent circle diameter of the primary particles. The equivalent circle diameter at which the cumulative value reaches 50% from the small diameter side in the number-based distribution of the equivalent circle diameter is defined as the average primary particle size.

[0096] When the green toner according to this embodiment contains resin particles, the external addition amount of the resin particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 parts by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles. When the green toner according to this embodiment contains acrylic resin particles, the external addition amount of the acrylic resin particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 parts by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles.

[0097] [Titanate compound particles] From the viewpoint of suppressing the occurrence of color streaks in the image, the green toner according to this embodiment preferably contains titanate compound particles as an external additive. The titanate compound particles have a polishing action on the surface of the image carrier and suppress filming on the surface of the image carrier.

[0098] The titanate compound particles may be particles mainly composed of a titanate compound. The titanate compound is called a metatitanate and is, for example, a salt formed from titanium oxide and another metal oxide or another metal carbonate.

[0099] As the titanate compound particles, alkaline earth metal titanate salt particles are preferable. The alkaline earth metal titanate is a salt represented by the compositional formula RTiO 3 (wherein R is one or more of alkaline earth metals).

[0100] Examples of the titanate compound particles include strontium titanate (SrTiO 3 ), calcium titanate (CaTiO 3 ), magnesium titanate (MgTiO 3 ), barium titanate (BaTiO 3 ), lead titanate (PbTiO 3 ), zinc titanate (ZnTiO 3Particles such as (...) can be mentioned. The titanate compound particles may be used alone or in combination of two or more.

[0101] The titanate compound particles may contain a dopant. Examples of the dopant include lanthanoids (e.g., lanthanum, cerium), silica, aluminum, magnesium, calcium, barium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, niobium, molybdenum, ruthenium, palladium, indium, antimony, tantalum, tungsten, rhenium, iridium, platinum, bismuth, yttrium, zirconium, niobium, silver, tin.

[0102] When the titanate compound particles contain a dopant, the amount of the dopant is preferably 0.1 mol% or more and 20 mol% or less, more preferably 0.1 mol% or more and 15 mol% or less, and still more preferably 0.1 mol% or more and 10 mol% or less, based on the metal atoms other than titanium. When the alkaline earth metal titanate particles contain a dopant, the amount of the dopant is preferably 0.1 mol% or more and 20 mol% or less, more preferably 0.1 mol% or more and 15 mol% or less, and still more preferably 0.1 mol% or more and 10 mol% or less, based on the alkaline earth metal atoms. When the strontium titanate particles contain a dopant, the amount of the dopant is preferably 0.1 mol% or more and 20 mol% or less, more preferably 0.1 mol% or more and 15 mol% or less, and still more preferably 0.1 mol% or more and 10 mol% or less, based on strontium.

[0103] The surface of the titanate compound particles may be subjected to a hydrophobization treatment. Examples of the hydrophobization treatment agent include silane-based coupling agents, silicone oils, etc. Examples of the silane coupling agent include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, benzyldimethylchlorosilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-butyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and the like. Examples of the silicone oil include dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, and the like.

[0104] From the viewpoint of uniformly coating the surface of the toner particles, the average primary particle diameter of the titanic acid compound particles is preferably 10 nm or more and 100 nm or less, more preferably 15 nm or more and 80 nm or less, and still more preferably 20 nm or more and 60 nm or less. From the viewpoint of polishing the surface of the image carrier and suppressing filming on the surface of the image carrier, the average primary particle diameter of the titanic acid compound particles is more preferably 100 nm or more and 2000 nm or less, still more preferably 300 nm or more and 1800 nm or less, and even more preferably 500 nm or more and 1500 nm or less.

[0105] The method for obtaining the average primary particle diameter of the titanic acid compound particles is as follows. Energy dispersive X-ray analyzer (EDX analyzer) (manufactured by Horiba, Ltd., EMAX Evolution X-Max80mm 2Using a scanning electron microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, S-4800) equipped with , toner is photographed at a magnification of 40,000 times. Based on the presence of titanium and oxygen elements by EDX analysis, 200 titanium acid compound particles are identified from within a single field of view. Images of 200 titanium acid compound particles are analyzed using image processing and analysis software WinRoof (manufactured by Mitani Shoko Co., Ltd.). The equivalent circle diameter of the primary particles is determined, and the equivalent circle diameter at which the cumulative percentage from the smaller diameter side reaches 50% in the equivalent circle diameter distribution is defined as the average primary particle diameter.

[0106] When the green toner according to this embodiment contains titanium acid compound particles, the external addition amount of the titanium acid compound particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles. When the green toner according to this embodiment contains alkaline earth metal titanate particles, the external addition amount of the alkaline earth metal titanate particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles. When the green toner according to this embodiment contains strontium titanate particles, the external addition amount of the strontium titanate particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles.

[0107] From the viewpoint of suppressing the occurrence of color streaks in the image, the green toner according to this embodiment preferably contains lubricant particles, resin particles, and titanium acid compound particles as external additives, and more preferably contains fatty acid metal salt particles, acrylic resin particles, and strontium titanate particles. The preferred forms of the lubricant particles, fatty acid metal salt particles, resin particles, acrylic resin particles, titanium acid compound particles, and strontium titanate particles are as described above.

[0108] When the green toner according to this embodiment contains resin particles and titanate compound particles, the external addition amounts of the resin particles and the titanate compound particles are preferably in the following ranges. The external addition amount of the resin particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 parts by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles. The external addition amount of the titanate compound particles is preferably 0.05 parts by mass or more and 1.0 part by mass or less, more preferably 0.08 parts by mass or more and 0.8 part by mass or less, and still more preferably 0.1 parts by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the green toner particles.

[0109] [Other external additives] The green toner according to this embodiment may contain inorganic particles other than titanate compound particles. Examples of the inorganic particles include SiO 2 , 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.

[0110] The surface of the above inorganic particles is preferably subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents, and the like. These may be used alone or in combination of two or more.

[0111] When the green toner according to the present embodiment contains the above inorganic particles, the externally added amount of the inorganic particles 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 with respect to 100 parts by mass of the toner particles.

[0112] From the viewpoint of achieving a good balance in the fluidity of the toner, the transferability to the recording medium, the suppression of color streaks, etc., the green toner according to the present embodiment preferably contains silica particles, lubricant particles, resin particles, and titanate compound particles as external additives, and more preferably contains hydrophobic silica particles, fatty acid metal salt particles, acrylic resin particles, and strontium titanate particles. The preferred forms of the silica particles, hydrophobic silica particles, lubricant particles, fatty acid metal salt particles, resin particles, acrylic resin particles, titanate compound particles, and strontium titanate particles are as described above.

[0113] [Manufacturing method of green toner] The green toner according to the present 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 a lubricant.

[0114] The green toner particles may be manufactured by any of a dry method (for example, kneading and grinding method, etc.) and a wet method (for example, aggregation method, suspension polymerization method, dissolution suspension method, etc.). There is no particular limitation on these manufacturing methods, and known manufacturing methods are adopted. Among these, it is preferable to obtain toner particles by the aggregation method.

[0115] 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 an adhesive resin are dispersed (resin particle dispersion liquid preparation step); A step of preparing a fluorescent pigment (Y) dispersion liquid in which an azomethine fluorescent pigment (Y) is dispersed (fluorescent pigment (Y) dispersion liquid preparation step); A step of preparing a pigment (G) dispersion liquid in which a pigment (G) is dispersed (pigment (G) dispersion liquid preparation step); A step of aggregating the mixed particles in a mixed dispersion liquid obtained by mixing the resin particle dispersion liquid, the fluorescent pigment (Y) dispersion liquid, and the pigment (G) dispersion liquid to form aggregated particles (aggregated particle formation step); A step of heating an aggregated particle dispersion liquid in which aggregated particles are dispersed to fuse and unite the aggregated particles to form green toner particles (fusion and unification step); The manufacturing method has these steps.

[0116] 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 needed.

[0117] - Resin Particle Dispersion Liquid Preparation Step - The resin particle dispersion liquid is prepared, for example, by dispersing resin particles in a dispersion medium with a surfactant.

[0118] Examples of the dispersion medium used for the resin particle dispersion liquid 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 surfactants include anionic surfactants such as sulfate ester salts, sulfonates, 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. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. The surfactant may be used alone or in combination of two or more.

[0120] In the resin particle dispersion, examples of the method for dispersing the resin particles in the dispersion medium include general dispersion methods such as a rotary shear type homogenizer, a ball mill having media, a sand mill, and a dyno mill. 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 the 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.

[0121] The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is preferably, for example, 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and still more preferably 0.1 μm or more and 0.6 μm or less. The volume average particle diameter of the resin particles is measured using the particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.). For the divided particle size range (channel), the cumulative distribution is drawn from the small particle size side with respect to the volume, and the particle diameter at which the cumulative value becomes 50% with respect to all particles is measured as the volume average particle diameter D50v. The volume average particle diameter of the particles in other dispersions is also measured in the same manner.

[0122] 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.

[0123] 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.

[0124] - 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.

[0125] Examples of the dispersion medium used for the fluorescent pigment (Y) 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.

[0126] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, particularly, anionic surfactants and cationic surfactants are mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0127] Examples of the method for dispersing the azomethine fluorescent pigment (Y) 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.

[0128] The volume average particle diameter of the azomethine fluorescent pigment (Y) dispersed in the fluorescent pigment (Y) dispersion is, for example, preferably 30 nm or more and 800 nm or less, more preferably 50 nm or more and 700 nm or less, still more preferably 150 nm or more and 600 nm or less, and still more preferably 250 nm or more and 400 nm or less. The particle diameter of the azomethine fluorescent pigment (Y) can be adjusted, for example, by the method and time of the dispersion treatment.

[0129] 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.

[0130] - 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.

[0131] Examples of the dispersion medium used for 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.

[0132] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, particularly, anionic surfactants and cationic surfactants are mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

[0133] 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 with media, a sand mill, a dyno mill, a kimi mill, etc.

[0134] The volume average particle diameter of the pigment (G) dispersed in the pigment (G) dispersion is, for example, 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 even 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.

[0135] 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.

[0136] -Agglomerated particle formation step- Mix the resin particle dispersion, the fluorescent pigment (Y) dispersion, the pigment (G) dispersion, and the release agent particle dispersion. Then, in the mixed dispersion, hetero-aggregate the resin particles, the azomethine fluorescent pigment (Y), the pigment (G), and the release agent particles to form agglomerated particles containing the resin particles, the azomethine fluorescent pigment (Y), the pigment (G), and the release agent particles, which have a diameter close to the diameter of the target toner particles.

[0137] Specifically, for example, an aggregating agent is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be 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, the glass transition temperature of the resin particles - 30°C or more and the glass transition temperature of the resin particles - 10°C or less) to aggregate the particles dispersed in the mixed dispersion and form agglomerated particles. In the agglomerated particle formation step, for example, the mixed dispersion may be stirred with a rotary shear homogenizer at room temperature (for example, 25°C), an aggregating agent may be added, the pH of the mixed dispersion may be adjusted to be acidic (for example, pH 2 or more and 5 or less), and a dispersion stabilizer may be added as necessary, and then heating may be performed.

[0138] Examples of the aggregating agent include a surfactant having a polarity opposite to that of 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 aggregating agent, 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 ions of the flocculant may be used as needed together with the flocculant. As this additive, a chelating agent is preferably used.

[0139] Examples of the inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and the like. As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and the like. The addition amount of the chelating agent is preferably 0.01 part by mass or more and 5.0 parts by mass or less, and more preferably 0.1 part by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

[0140] -Fusion and Unification Step- Next, the flocculated particle dispersion in which the flocculated 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 unite the flocculated particles to form toner particles.

[0141] Through the above steps, toner particles are obtained. After obtaining the flocculated particle dispersion in which the flocculated particles are dispersed, the flocculated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed and flocculated so that the resin particles further adhere to the surface of the flocculated particles to form second flocculated particles, and the second flocculated particle dispersion in which the second flocculated particles are dispersed is heated to fuse and unite the second flocculated particles to form toner particles having a core-shell structure. Through these steps, toner particles may be manufactured.

[0142] After the fusion and integration process is completed, the toner particles in the dispersion are subjected to known cleaning, solid-liquid separation, and drying processes to obtain toner particles in a dried state. From the perspective of chargeability, it is advisable to perform sufficient replacement cleaning with ion-exchanged water in the cleaning process. From the perspective of productivity, it is advisable to perform suction filtration, pressure filtration, etc. in the solid-liquid separation process. From the perspective of productivity, it is advisable to perform freeze drying, airflow drying, fluidized drying, vibration-type fluidized drying, etc. in the drying process.

[0143] The toner according to this embodiment is manufactured, for example, by adding and mixing an external additive to the obtained toner particles in a dried state. The mixing may be performed, for example, by a V blender, a Henschel mixer, a Lodige mixer, etc. Further, if necessary, coarse particles of the toner may be removed using a vibrating sieve, an air classifier, etc.

[0144] When mixing the toner particles and the lubricant, the weak adhesion ratio of the lubricant is controlled by adjusting the rotation speed and / or rotation time of the blender or mixer.

[0145] <Electrostatic charge image developer> The electrostatic charge image developer according to this embodiment contains at least the green toner according to this embodiment. The electrostatic charge image developer according to this embodiment may be a one-component developer containing only the green toner according to this embodiment, or a two-component developer in which the green toner and a carrier are mixed.

[0146] 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-dispersed carrier in which magnetic powder is dispersed and blended in a matrix resin; a resin-impregnated carrier in which porous magnetic powder is impregnated with resin; and the like. The magnetic powder-dispersed carrier and the resin-impregnated carrier may be carriers in which the constituent particles of the carrier are used as the core material and the surface thereof is coated with resin.

[0147] Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and the like.

[0148] Examples of the resin for coating and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic ester copolymer, straight silicone resin containing an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenol resin, epoxy resin, acrylic resin, and the like.

[0149] From the viewpoint of the chargeability of the carrier, an acrylic resin is preferable as the resin for coating, and an acrylic resin having an alicyclic structure is more preferable. The mass ratio of the acrylic resin in the entire 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 entire resin of the resin for coating is preferably 50% by mass or more, and more preferably 80% by mass or more.

[0150] 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 the 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 a 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, a (meth)acrylic acid alkyl ester having an alkyl group with 1 to 9 carbon atoms) is preferred. 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, and 2-ethylhexyl (meth)acrylate. These monomers may be used alone or in combination of two or more.

[0151] 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.

[0152] 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.

[0153] To coat the surface of the core material with resin, methods such as coating with a coating solution in which a resin for coating and various additives (used as necessary) are dissolved in an appropriate solvent can be mentioned. The solvent is not particularly limited and may be selected in consideration of the type of resin used, coating applicability, etc. Specific resin coating methods include: an immersion method in which the core material is immersed in a coating solution for forming a coating layer; a spray method in which the coating solution for forming a coating layer is sprayed onto the surface of the core material; a fluidized bed method in which the coating solution for forming a coating layer is sprayed while the core material is suspended by flowing air; a kneader coater method in which the core material of the carrier and the coating solution for forming a coating layer are mixed in a kneader coater and then the solvent is removed; etc.

[0154] The mixing ratio (mass ratio) of the green toner and the carrier in the two-component developer is preferably green toner:carrier = 1:100 to 30:100, and more preferably 3:100 to 20:100.

[0155] <Image forming apparatus, image forming method> The image forming apparatus and image forming method according to this embodiment will be described. The image forming apparatus according to this embodiment includes an image carrier, a charging means for charging the surface of the image carrier, an electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the image carrier, a developing means for accommodating an electrostatic charge image developer and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer, a transfer means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium. And, as the electrostatic charge image developer, the electrostatic charge image developer according to this embodiment is applied.

[0156] In the image forming apparatus according to the present embodiment, there are 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 by 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 (image forming method according to the present embodiment).

[0157] 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 the 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 the recording medium; an apparatus provided with cleaning means for cleaning the surface of the image carrier before charging after the transfer of the toner image; an apparatus provided with charge eliminating means for irradiating the surface of the image carrier with charge eliminating light to eliminate charge before charging after the transfer of the toner image; 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 has, for example, a configuration including an intermediate transfer member on the surface of which a toner image is transferred, a primary transfer means for primarily transferring the toner image formed on the surface of the image carrier 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.

[0158] In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge that houses the electrostatic charge image developer according to the present embodiment and includes developing means is preferably used.

[0159] Hereinafter, an example of the image forming apparatus according to the present embodiment is shown, but the present invention is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the description of the others will be omitted.

[0160] In the following description, as an example of the image forming apparatus according to the present embodiment, a six-unit tandem type image forming apparatus in which six image forming units are arranged in a row will be described. The tandem type image forming apparatus is not limited to this, and a five-unit tandem type image forming apparatus in which five image forming units are arranged in a row, a four-unit tandem type image forming apparatus in which four image forming units are arranged in a row, or the like may be used.

[0161] FIG. 1 is a schematic configuration diagram showing the image forming apparatus according to the present embodiment, and is a diagram showing a six-unit tandem type and intermediate transfer type image forming apparatus. The image forming apparatus shown in FIG. 1 includes first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, and 10G which are electrophotographic image forming means for outputting images of respective colors of pink (P), yellow (Y), magenta (M), cyan (C), black (K), and green (G) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10P, 10Y, 10M, 10C, 10K, and 10G are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10P, 10Y, 10M, 10C, 10K, and 10G may be process cartridges that are detachable from the image forming apparatus.

[0162] 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 configured to travel in the direction from the first unit 10P to the sixth unit 10G. An intermediate transfer body cleaning device 21 is provided on the image holding surface side of the intermediate transfer belt 20 so as to face the driving roll 22.

[0163] To each of the developing devices (an example of developing means) 4P, 4Y, 4M, 4C, 4K, 4G of the respective units 10P, 10Y, 10M, 10C, 10K, 10G, pink, yellow, magenta, cyan, black, and green toners stored in toner cartridges 8P, 8Y, 8M, 8C, 8K, 8G are supplied.

[0164] Since the first to sixth units 10P, 10Y, 10M, 10C, 10K, 10G have the same configuration and operation, here, the sixth unit 10G that forms a green image will be described as a representative.

[0165] The sixth unit 10G has a photosensitive member 1G that acts as an image holding member. Around the photosensitive member 1G, a charging roll (an example of charging means) 2G that charges the surface of the photosensitive member 1G to a predetermined potential, an exposure device (an example of electrostatic charge image forming means) 3G that exposes the charged surface with a laser beam based on a color-separated image signal to form an electrostatic charge image, a developing device (an example of developing means) 4G that supplies toner to the electrostatic charge image to develop the electrostatic charge image, a primary transfer roll (an example of primary transfer means) 5G that transfers the developed toner image onto the intermediate transfer belt 20, and a photosensitive member cleaning device (an example of cleaning means) 6G that removes the toner remaining on the surface of the photosensitive member 1G after primary transfer are arranged in order.

[0166] The primary transfer roll 5G is disposed inside the intermediate transfer belt 20 and is provided at a position facing the photosensitive member 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).

[0167] 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 photosensitive member 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 substrate with conductivity (for example, a volume resistivity of 1×10 -6 Ωcm or less at 20°C). This photosensitive layer is usually of high resistance (the resistance of a general resin), but has the property that when irradiated with a laser beam, the specific resistance of the irradiated portion of the photosensitive layer changes. Therefore, a laser beam is irradiated from the exposure device 3G onto the surface of the charged photoreceptor 1G according to the 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.

[0168] The electrostatic charge image is an image formed on the surface of the photoreceptor 1G by charging, and is a so-called negative latent image formed by the laser beam from the exposure device 3G causing the specific resistance of the irradiated portion of the photosensitive layer to decrease, the charged charges on the surface of the photoreceptor 1G to flow, and the charges in the portion not irradiated with the laser beam to remain. 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.

[0169] Inside the developing device 4G, an electrostatic charge image developer containing, for example, at least green toner and a 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). Then, as the surface of the photoreceptor 1G passes through the developing device 4G, the green toner electrostatically adheres to the discharged latent image portion on the surface of the photoreceptor 1G, and the latent image is developed by the green toner. The photoreceptor 1G on which the green toner image is formed continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1G is conveyed to a predetermined primary transfer position.

[0170] 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, causing the toner image on the photoreceptor 1G to be transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (-) of the toner, and in the first unit 10G, it is controlled, for example, to +10 μA by a control unit (not shown).

[0171] After the toner image is transferred 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.

[0172] The intermediate transfer belt 20 is sequentially conveyed through the first to sixth image forming units 10P, 10Y, 10M, 10C, 10K, 10G, and the toner images of each color are overlapped and multi-transferred.

[0173] The intermediate transfer belt 20 on which the six-color toner images are multi-transferred through the first to sixth units reaches a secondary transfer unit composed of the intermediate transfer belt 20, 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 to the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a feeding mechanism, and a secondary transfer bias is applied to the counter roll 24. The transfer bias applied at this time has a polarity (-) the same as the polarity (-) of the toner, and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, causing the toner image on the intermediate transfer belt 20 to be transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) that detects the resistance of the secondary transfer unit and is voltage-controlled.

[0174] After the toner image is transferred to the recording paper P, the intermediate transfer belt 20 continues to run and contacts the cleaning blade provided in the intermediate transfer member cleaning device 21. The toner remaining on the intermediate transfer belt 20 is removed and recovered by the intermediate transfer member cleaning device 21.

[0175] The recording paper P onto which the toner image has been transferred is fed into the pressure contact portion (nip portion) of a pair of fixing rolls in the fixing device (an example of a fixing means) 28, and the toner image is fixed onto the recording paper P to form a fixed image.

[0176] Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copiers, printers, etc. Examples of the recording medium include OHP sheets in addition to the recording paper P. 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 with the surface of plain paper coated with resin or the like, art paper for printing, etc. are preferably used.

[0177] The recording paper P on which the fixing of the color image has been completed is carried out toward the discharge unit, and a series of color image forming operations are terminated.

[0178] <Process cartridge, toner cartridge> The process cartridge according to this embodiment will be described. The process cartridge according to this embodiment houses the electrostatic charge image developer according to this embodiment, and includes developing means for developing the electrostatic charge image formed on the surface of the image carrier as a toner image, and is a process cartridge that is detachable from the image forming apparatus.

[0179] The process cartridge according to this 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.

[0180] An example of the process cartridge according to the present embodiment is shown below, but the present invention is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the description of the other parts will be omitted.

[0181] FIG. 2 is a schematic configuration diagram showing a 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 holding member), 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 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 is an exposure device (an example of electrostatic charge image forming means), 112 is a transfer device (an example of transfer means), 115 is a fixing device (an example of fixing means), and 300 is a recording paper (an example of a recording medium).

[0182] 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 the image forming apparatus. The toner cartridge houses replenishing toner for supplying to developing means provided in the image forming apparatus.

[0183] 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, and the developing devices 4Y, 4P, 4M, 4C, 4G, and 4K are connected to the toner cartridges corresponding to the respective colors by toner supply pipes (not shown). Further, when the toner housed in the toner cartridge becomes less, the toner cartridge is replaced. An example of the toner cartridge according to the present embodiment is the toner cartridge 8G, and the green toner according to the present embodiment is housed therein. The toner cartridges 8P, 8Y, 8M, 8C, and 8K house pink, yellow, magenta, cyan, and black toners, respectively.

Example

[0184] Hereinafter, embodiments of the invention will be described in detail with reference to 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.

[0185] <Preparation 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 rotation speed of 190 rpm for 30 minutes to obtain a coating agent.

[0186] 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 75°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 screened with a mesh having an opening of 75 μm to remove coarse powder, thereby obtaining a carrier.

[0187] <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 introduction 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 a temperature of 230 °C for 1 hour, and then cool the inside of 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 an amorphous polyester resin was gradually added and dissolved. Next, 3 molar equivalents of a 10% aqueous ammonia solution were added based on the acid value of the amorphous polyester resin, and the mixture was 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 added dropwise 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%.

[0188] [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 perform a dispersion treatment with a pressure discharge type homogenizer (Gorin). Recover when the volume average particle size reaches 200 nm to obtain a release agent particle dispersion (1) with a solid content of 20%.

[0189] [Preparation of pigment dispersion (Y101)] · C.I. Pigment Yellow 101: 70 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume-average particle size of 300 nm using a continuous kneader mill (KMC-3, Inoue Seisakusho Co., Ltd.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (Y101).

[0190] [Preparation of Pigment Dispersion (PG36)] · C.I. Pigment Green 36: 70 parts · Anionic surfactant (Neogen RK, Daiichi Kogyo Seiyaku Co., Ltd.): 30 parts (solid content 20%) · Ion-exchanged water: 200 parts The above materials were mixed and pulverized to a volume-average particle size of 150 nm using a continuous kneader mill (KMC-3, Inoue Seisakusho Co., Ltd.). It was adjusted to a solid content of 20% to obtain a pigment dispersion (PG36).

[0191] [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, Daiichi 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). While stirring the inside of the flask, it was heated to 45 °C in an oil bath for heating and held for 30 minutes. Next, 50 parts of the resin particle dispersion (1) (solid content 20%) was added and held for 1 hour. Then, the pH was adjusted to 8.5 using a 0.1 mol / L aqueous sodium hydroxide solution, and while continuing stirring, it was heated to 84 °C and held for 2.5 hours. Then, it was cooled to room temperature at a rate of 20 °C / min, subjected to solid-liquid separation, and thoroughly washed with ion-exchanged water. The solid content was vacuum-dried to obtain green toner particles (1). The volume average particle diameter of the green toner particles (1) was 5.8 μm.

[0192] [Preparation of Green Toner and Green Developer] · Green toner particles (1): 100 parts · Hydrophobic silica particles (RY50, Nippon Aerosil Co., Ltd.): 3.0 parts · Polymethyl methacrylate resin particles (average primary particle diameter 300 nm): 0.2 part · Strontium titanate particles (average primary particle diameter 1500 nm): 0.2 part · Zinc stearate particles (volume average particle diameter 1500 nm): 0.1 part

[0193] The total amount of green toner particles (1), hydrophobic silica particles, polymethyl methacrylate resin particles, and strontium titanate particles, and half of the amount of zinc stearate particles were put into a sample mill and mixed at a rotational speed of 10000 rpm for 30 seconds. Next, the remaining amount of zinc stearate particles was added to the sample mill and mixed at a rotational speed of 10000 rpm for 30 seconds. After that, it was sieved with a vibrating sieve having an aperture of 45 μm to obtain an externally added toner. 10 parts of the externally added toner and 100 parts of the carrier were put into a V blender and stirred for 20 minutes. Then, it was sieved with a sieve having an aperture of 212 μm to obtain a green developer.

[0194] <Comparative Example 1> In the same manner as in Example 1, except that zinc stearate particles were not externally added, green toner particles, a green toner, and a green developer were produced.

[0195] <Example 2> In the same manner as in Example 1, except that in the production of the green toner particles, C.I. Pigment Green 36 was replaced with C.I. Pigment Green 59, green toner particles, a green toner, and a green developer were produced.

[0196] <Example 3> In the same manner as in Example 1, except that zinc stearate particles were replaced with boron nitride particles (volume average particle diameter: 1200 nm), green toner particles, a green toner, and a green developer were produced.

[0197] <Examples 4 to 7> In the same manner as in Example 1, except that the externally added amount of zinc stearate particles was changed to the specifications described in Table 1, green toner particles, a green toner, and a green developer were produced.

[0198] <Example 8> In the same manner as in Example 1, except that the sample mill treatment when mixing the green toner particles and the external additive was changed to 60 seconds once (that is, the addition of zinc stearate particles was not divided into two times but made once), green toner particles, a green toner, and a green developer were produced.

[0199] <Example 9> In the same manner as in Example 1, except that the sample mill treatment when mixing the green toner particles and the external additive was changed to 45 seconds once (that is, the addition of zinc stearate particles was not divided into two times but made once), green toner particles, a green toner, and a green developer were produced.

[0200] <Example 10> In the same manner as in Example 1, except that the sample mill treatment when mixing the green toner particles and the external additive was changed to 30 seconds for the first time and 25 seconds for the second time, green toner particles, green toner, and green developer were produced.

[0201] <Example 11> In the same manner as in Example 1, except that the sample mill treatment when mixing the green toner particles and the external additive was changed to 30 seconds for the first time and 20 seconds for the second time, green toner particles, green toner, and green developer were produced.

[0202] <Example 12> In the same manner as in Example 1, except that polymethyl methacrylate resin particles were not externally added, green toner particles, green toner, and green developer were produced.

[0203] <Example 13> In the same manner as in Example 1, except that strontium titanate particles were not externally added, green toner particles, green toner, and green developer were produced.

[0204] <Examples 14 to 17, Comparative Examples 2 to 5> In the same manner as in Example 1, except that the amount of the pigment dispersion used in the production of the green toner particles was changed, green toner particles, green toner, and green developer were produced.

[0205] <Examples 18 to 19> 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 were changed to the specifications shown in Table 1, green toner particles, green toner, and 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.

[0206] <Performance Evaluation> [Image Formation] Iridesse Production Press (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 with a temperature of 25°C and a relative humidity of 55%, on A4-sized coated paper (OS coated paper, 127 g / m 2 , Fuji Film Business Innovation Co., Ltd.), a solid green image (concentration 100%, size 5 cm × 5 cm, toner loading 4.0 g / m 2 ) was formed.

[0207] [Reflectance] One hundred images were formed, and 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 within the 100th 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%

[0208] [Color streaks] After forming 100,000 images, the last 10 images were visually observed, and the photoreceptor contact portion of the photoreceptor cleaning blade was magnified 100 times with a microscope (Keyence VH6200) and observed. The number of color streaks generated in the image and the state of the photoreceptor cleaning blade were classified as follows. A: There are 0 color streaks and there is no chip in the photoreceptor cleaning blade. B: There are 0 color streaks and there is a chip in the photoreceptor cleaning blade. C: There are 1 to 5 color streaks and there is a chip in the photoreceptor cleaning blade. D: There are 6 or more color streaks and there is a chip in the photoreceptor cleaning blade.

[0209] The symbols in Table 1 mean the following compounds. · 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 (Toyobo Co., Ltd., LIONOL GREEN 8624, reflection peak 510 nm), one kind of pigment (G) · PG59: C.I. Pigment Green 59 (DIC Corporation, FASTOGEN GREEN C100, reflection peak 520 nm), one kind of pigment (G) · ZnSt: Zinc stearate · BN: Boron nitride · PMMA: Polymethyl methacrylate resin · SrTiO3: Strontium titanate

[0210]

Table 1

[0211] <Image formation with the 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 - sized coated paper based on the image data obtained by color - separating RGB data into the above six colors. An image with good color reproducibility close to the original RGB data was obtained.

[0212] 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.

[0213] (((1))) Containing 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 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 on a mass basis. Green toner particles, and a lubricant externally added to the green toner particles. A green toner for electrostatic charge image development. (((2))) The lubricant is contained in an amount of 0.02 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the green toner particles. The green toner for electrostatic charge image development according to ((1)). (((3))) The lubricant contains fatty acid metal salt particles. The green toner for electrostatic charge image development according to ((1)) or ((2)). (((4))) When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the fatty acid metal salt particles desorbed from the green toner particles are 10% by mass or more and 30% by mass or less of the fatty acid metal salt particles externally added to the green toner particles. The green toner for electrostatic charge image development according to ((3)). (((5))) Furthermore, it contains resin particles externally added to the green toner particles. The green toner for electrostatic charge image development according to any one of ((1)) to ((4)). (((6))) Furthermore, it contains titanate compound particles externally added to the green toner particles. The green toner for electrostatic charge image development according to any one of ((1)) to ((5)). (((7))) Furthermore, it contains resin particles and titanate compound particles externally added to the green toner particles. The green toner for electrostatic charge image development according to any one of ((1)) to ((4)). (((8))) 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, (((1)))~(((7))) Any one of the green toners for electrostatic charge image development described in. (((9))) the azomethine fluorescent pigment is C.I. Pigment Yellow 101, (((1)))~(((8))) Any one of the green toners for electrostatic charge image development described in. (((10))) the non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 36, C.I. Pigment Green 7, C.I. Pigment Green 58, C.I. Pigment Green 59 and C.I. Pigment Blue 76, (((1)))~(((9))) Any one of the green toners for electrostatic charge image development described in.

[0214] (((11))) (((1)))~(((10))) An electrostatic charge image developer containing the green toner for electrostatic charge image development described in any one of the preceding paragraphs. (((12))) (((1)))~(((10))) A toner cartridge that houses the green toner for electrostatic charge image development described in any one of the preceding paragraphs and is detachable from an image forming apparatus. (((13))) (((11))) A developing unit that houses the electrostatic charge image developer described in 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. (((14))) 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 surface of the charged image carrier, Developing means for containing the electrostatic charge image developer described in ((11)) and developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer; Transferring means for transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; Fixing means for fixing the toner image transferred to the surface of the recording medium; An image forming apparatus comprising the above. (((15))) A charging step of charging the surface of the image carrier; An electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image carrier; A developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer described in ((11)); A transferring step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; A fixing step of fixing the toner image transferred to the surface of the recording medium; An image forming method comprising the above. (((16))) An electrophotographic image forming apparatus comprising 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 ((11)); An image forming apparatus. (((17))) An electrophotographic image forming method having 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 ((11)); An image forming method.

[0215] According to ((1)), ((3)), ((9)), or ((10)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur compared to a green toner for electrostatic charge image development to which no lubricant is externally added. According to ((2)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur as compared with a green toner for electrostatic charge image development having an external addition amount of a lubricant of less than 0.02 parts by mass. According to ((4)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur as compared with a green toner for electrostatic charge image development having fatty acid metal salt particles desorbing from the green toner particles of less than 10% by mass. According to ((5)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur as compared with a green toner for electrostatic charge image development to which resin particles are not externally added. According to ((6)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur as compared with a green toner for electrostatic charge image development to which titanate compound particles are not externally added. According to ((7)), there is provided a green toner for electrostatic charge image development in which color streaks are less likely to occur as compared with a green toner for electrostatic charge image development to which resin particles are not externally added or a green toner for electrostatic charge image development to which titanate compound particles are not externally added. According to ((8)), there is provided a green toner for electrostatic charge image development having excellent reflectance as compared with a green toner for electrostatic charge image development containing green toner particles in which the volume average particle diameter D1 of an 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 an azomethine fluorescent pigment and the volume average particle diameter D2 of a non-fluorescent pigment satisfy D1 < D2.

[0216] According to ((11)), there is provided an electrostatic charge image developer in which color streaks are less likely to occur as compared with the case where no lubricant is externally added to a green toner for electrostatic charge image development. According to ((12)), there is provided a toner cartridge in which color streaks are less likely to occur as compared with the case where no lubricant is externally added to a green toner for electrostatic charge image development. According to ((13)), there is provided a process cartridge in which color streaks are less likely to occur as compared with the case where no lubricant is externally added to a green toner for electrostatic charge image development. According to ((14)) or ((16)), there is provided an image forming apparatus in which color streaks are less likely to occur as compared with the case where no lubricant is externally added to the green toner for electrostatic charge image development. According to ((15)) or ((17)), there is provided an image forming method in which color streaks are less likely to occur as compared with the case where no lubricant is externally added to the green toner for electrostatic charge image development.

Explanation of Signs

[0217] 1P, 1Y, 1M, 1C, 1K, 1G Photoreceptor (an example of an image holding member) 2P, 2Y, 2M, 2C, 2K, 2G Charging roll (an example of charging means) 3P, 3Y, 3M, 3C, 3K, 3G Exposure device (an example of electrostatic charge image forming means) 4P, 4Y, 4M, 4C, 4K, 4G Developing device (an example of developing means) 5P, 5Y, 5M, 5C, 5K, 5G Primary transfer roll (an example of primary transfer means) 6P, 6Y, 6M, 6C, 6K, 6G Photoreceptor 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 an intermediate transfer member) 21 Intermediate transfer member cleaning device 22 Driving roll 23 Support roll 24 Opposing roll 26 Secondary transfer roll (an example of secondary transfer means) 28 Fixing device (an example of fixing means) P Recording paper (an example of a recording medium)

[0218] 107 Photoreceptor (an example of an 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 a lubricant externally added to the green toner particles. A green toner for electrostatic charge image development.

2. The green toner for electrostatic charge image development according to claim 1, wherein the lubricant is contained in an amount of 0.02 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the green toner particles. The green toner for electrostatic charge image development according to claim 1.

3. The green toner for electrostatic charge image development according to claim 1, wherein the lubricant contains fatty acid metal salt particles. The green toner for electrostatic charge image development according to claim 1.

4. When the green toner for electrostatic charge image development is dispersed in water containing a surfactant and subjected to ultrasonic treatment at an output of 20 W, a frequency of 20 kHz, and for 1 minute, the fatty acid metal salt particles detached from the green toner particles are 10% by mass or more and 30% by mass or less of the fatty acid metal salt particles externally added to the green toner particles. The green toner for electrostatic charge image development according to claim 3.

5. The green toner for electrostatic charge image development according to claim 1, further comprising resin particles externally added to the green toner particles. The green toner for electrostatic charge image development according to claim 1.

6. The green toner for electrostatic charge image development according to claim 1, further comprising titanate compound particles externally added to the green toner particles. The green toner for electrostatic charge image development according to claim 1.

7. The green toner for electrostatic charge image development according to claim 1, further comprising resin particles and titanate compound particles externally added to the green toner particles. The green toner for electrostatic charge image development according to claim 1.

8. 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.

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

10. The non-fluorescent pigment is at least one selected from the group consisting of C.I. Pigment Green 36, C.I. Pigment Green 7, 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.

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

12. A toner cartridge that houses the green toner for electrostatic charge image development according to any one of claims 1 to 10 and is detachable from an image forming apparatus.

13. A developing unit that houses the electrostatic charge image developer according to claim 11 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.

14. 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 11 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, An image forming apparatus comprising the above components.

15. 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 11, A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, A fixing step of fixing the toner image transferred to the surface of the recording medium, An image forming method comprising the above steps.

16. 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 11. An image forming apparatus.

17. An electrophotographic image forming method having 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 11, Image forming method.

Images