JP2010054800A - Full-color image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a full-color image forming method capable of obtaining a full-color image of preferable image quality without density fluctuation and image roughness even in an image forming environment where the charge distribution of a toner is easily turned to be broad by a supply of additional toner and carrier in the full-color image forming method of two-component developing system which adopts a trickle developing system. <P>SOLUTION: The full-color image forming method includes a process of developing an electrostatic latent image while replenishing additional toner and carrier into a developing device from a replenishing developer storage container, wherein, when each monocolor toner image formed by using only a yellow toner, a magenta toner or a cyan toner presents the maximum chroma, the brightness L<SP>*</SP>exists in each specified range. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a full-color image forming method using a two-component development method, and in particular, when a latent image is developed with color toner, a trickle development method is used in which development is performed while supplying new toner and a carrier to the image forming apparatus. The present invention relates to a full-color image forming method.

  An electrophotographic image forming method in which toner is supplied to a photoreceptor on which an electrostatic latent image is formed to form an image is widely used in full-color print production in addition to monochrome print production represented by document creation. It came to be. Among them, active development in the so-called POD (Print On Demand) area, in which a necessary number of prints are produced without taking the trouble of generating a plate like printing, has been seen. Due to the development in the light printing field where there are many small print orders, full-color prints such as catalogs and advertisements are produced using toner (see, for example, Patent Document 1). However, the scale of print production in the light printing field is much larger than that in offices, and it is assumed that several thousand prints may be produced. There was a need for stability that would not cause fluctuations. In this field, there are many occasions for producing prints containing variable information, and the toner consumption may change with the change in the pixel ratio of the image during print production.

  By the way, in full-color image formation, image formation by a two-component development method using a developer composed of a toner and a carrier is widely performed, but in order to stably provide a full-color image with good image quality. Therefore, a two-component developer that can withstand long-term use has been demanded. In the two-component development method, the toner is rubbed on the carrier surface to be appropriately charged. However, if development is repeated over a long period of time, the resin layer on the carrier surface may be worn away or the toner component may be deposited on the carrier surface. As a result of adhesion and aggregation, the charging ability of the carrier decreases. As a result, there is a problem that it becomes difficult to supply a predetermined amount of toner by the carrier, the image density fluctuates, and in particular, it is difficult to obtain a predetermined color balance in full-color image formation. In addition, there are cases where several thousand prints are produced continuously, but it has been required to produce prints so that the density does not change between prints. It was difficult to achieve image quality stability like a printed matter.

Therefore, a so-called trickle development image forming method has been proposed in which toner is replenished for the amount consumed during development and the carrier is also replenished, and the charging ability of the carrier is maintained by gradually replacing the carrier in use. For example, see Patent Documents 2 and 3). However, when a new carrier is replenished among the deteriorated carriers, the toner charge amount distribution tends to become broad, and this tendency is prominent in large-scale printing in which the toner consumption increases. In this way, in an image forming environment where the amount of toner consumption is large, as the amount of new toner and carrier replenishment increases, so-called weakly charged toner that is not charged to a predetermined level relatively increases. Image defects such as image variations and density changes in the area were generated.
JP 2005-157314 A Japanese Patent Publication No. 2-21591 JP 2001-330985 A

  The present invention is a two-component development type full-color image forming method employing a trickle development method, and even when the toner charge amount distribution is broad and it is difficult to produce a print with good image quality, good image quality can be obtained. An object of the present invention is to provide a full color image forming method. Specifically, the density and color balance do not fluctuate and there is no image in the halftone area even under print production conditions that consume a large amount of toner, as in the case of large-scale continuous printing. A full color image forming method for stably forming a color image is provided.

The said subject is solved by the structure as described below. That is,
The invention described in claim 1
“Developing the electrostatic latent image formed on the photoreceptor using the developer while supplying the toner and the carrier into the developing device from the replenishment developer containing container containing the toner and the carrier. A full color image forming method comprising:
The full-color image forming method includes:
At least a full color image is formed using a developer composed of yellow toner and carrier, a developer composed of magenta toner and carrier, and a developer composed of cyan toner and carrier.
When the toner image formed with only the yellow toner has the maximum saturation, the lightness L ^* _Y is in the range of 80 to 90,
When the toner image formed only with the magenta toner has the maximum saturation, the lightness L ^* _M is in the range of 35 to 51,
A full-color image forming method, wherein a lightness L ^* _C is in a range of 53 to 70 when the toner image formed only of the cyan toner has maximum saturation. ].

The invention described in claim 2
The full-color image forming method according to claim 1, wherein the magenta toner contains a compound represented by the following general formula (1).

[Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₇ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁₅ and R ₁₆ each independently represent a hydrogen atom or carbon number. 1 or 2 alkyl groups are represented. M and n represent an integer of 1 or 2, and (X ⁻ ) represents a counter anion and represents a chlorine ion or a sulfonic acid compound ion. ]].

The invention according to claim 3
2. The full-color image forming method according to claim 1, wherein the magenta toner contains a compound represented by the following general formula (2).

[In the formula, each R ₂₁ independently represents a hydrogen atom or a substituent, R ₂₂ represents —NR ₂₄ R ₂₅ or —OR ₂₆ , and R ₂₃ represents a hydroxyl group, an alkoxy group, an aryloxy group, an amino group, an amide group, an alkylsulfonylamino group. Represents any group of an arylsulfonylamino group. A ₁₁ to A ₁₃ each independently represent a _{-CR 27} = or -N =.

X ₁₁ is an atomic group necessary for forming a 5- or 6-membered aromatic ring or heterocyclic ring, Z ₁ is a substituent necessary for forming a 5- or 6-membered heterocyclic ring containing at least one nitrogen atom And a condensed ring may be formed by the substituent. R _{24 to} R ₂₇ each independently represents a hydrogen atom or a substituent, L ₁₁ represents a linking group having 1 or 2 carbon atoms or a part of a ring structure, and is bonded to R ₂₃ to form a 5- or 6-membered ring structure. May be. p represents an integer of 0 to 3. ]].

The invention according to claim 4
The full-color image forming method according to any one of claims 1 to 3, wherein the cyan toner contains a compound represented by the following general formula (3).

[In the formula, each Z independently represents a hydroxy group, a chlorine group, an aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or a group represented by the following general formula (3-1). Show. A ^{1 to} A ⁴ represent a benzene ring. ]

[Wherein R ⁶¹ , R ⁶² , and R ⁶³ represent an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or an aryloxy group having 6 to 18 carbon atoms. Indicates a group. R ⁶¹ , R ⁶² and R ⁶³ may be the same group or different groups. ]].

  According to the present invention, in a full-color image forming method in which trickle development is performed using a two-component developer, a comfortable full-color image having a visually uncomfortable feeling can be obtained at any time. In other words, even in an image forming environment in which an external additive or the like selectively adheres to a newly replenished carrier surface due to an increase in toner consumption and generates a carrier spent that lowers the charging performance of the carrier. Stable image formation can be performed without lowering or color balance. In particular, since there is no image blur or fogging in the halftone area, for example, when creating a photographic image with a lot of halftone areas, a full-color image with a high-quality finish that is comfortable to the eyes and rich in three-dimensionality and uniformity is produced. It came to be obtained.

  Therefore, in a POD area where there are many opportunities to perform variable information printing, it is possible to stabilize a high-quality finished full-color print that is comfortable to the eye even if the toner consumption may increase rapidly as the pixel ratio of the output image changes. Can now be provided.

  The present invention develops an electrostatic latent image formed on a photoreceptor using a two-component developer composed of a toner and a carrier to form a full color image, and at least yellow toner, magenta toner, cyan toner Is used.

  In the full-color image forming method in which trickle development is performed using a two-component developer, the present inventor has a specific range of lightness when each single-color toner image formed by yellow toner, magenta toner, and cyan toner has maximum saturation. It was found that an image with a comfortable image quality without a sense of incongruity can be obtained. In the present invention, this performance is maintained even when an external additive or the like selectively adheres to the surface of the carrier newly replenished by trickle development to reduce the charging performance of the carrier. Specifically, when continuous printing is performed, density variations and poor color tone are not observed, and a full-color image with good image quality can be obtained. In particular, there are no image defects such as blurring or fogging in the halftone area. For example, when creating a photographic image with many halftone areas, it is a full-color photographic image with a high-quality finish that is comfortable to the eyes and rich in three-dimensionality and homogeneity. Can be obtained.

  In order to obtain a color image having a high-quality color that is comfortable to the eyes, the present inventor has made it possible to produce an image that is optimal for human visibility using toners of three colors of yellow, magenta, and cyan. I thought it was important. Then, by reconstructing the color design theory based on the Munsell color system model, we examined the toner image design that matches the human visual sensitivity.

  In the Munsell color system, the color tone can be illustrated by three attributes of hue, lightness, and saturation, which are called Munsell color solids. That is, the L axis representing the lightness is arranged at the center of the hue circle, the axis toward the bottom from the hue circle is blackened, and the axis toward the top is whitened. Further, the distance from the axis indicates the saturation, and the saturation increases as the distance from the axis increases. Usually, the Munsell color solid is not a perfect sphere, but forms a distorted sphere. This indicates that the human visual sensitivity cannot be detected equally for all hues.

  That is, there are four types of human photoreceptor cells: rod cells, blue cone cells, green cone cells, and red cone cells. Among them, the peak of the sensitivity curve of rod cells that sense brightness is 510 nm. Exists. In addition, blue cone cells (B cone) are sensitive to 400 to 500 nm, and the peak is about 430 nm. Green cone cells (G cones) are sensitive to the mid-wavelength range of 500-600 nm, and the peak is about 530 nm. Further, red cone cells (R cones) are sensitive to a long wavelength region of 550 to 650 nm, and the peak exists at about 560 nm. The peak of the red cone is not necessarily a red region, but rather a yellow-green to yellow region.

  The present inventor has sought to make it possible to set the brightness of the magenta toner, which controls the long wavelength region where the sensitivity of rod cells is low, to be higher than before. In the short wavelength range, the color tone is expressed by magenta and cyan, so the brightness of cyan toner was set to be higher than before. Then, as we continue to study, we realized that simply increasing the brightness of these toner images would reduce the expressive power of the dark part of the image, and after further investigation, by specifying the brightness when taking the maximum saturation, It has been found that the effect is manifested. That is, the ideal distortion of the Munsell color solid, that is, the ideal degree of deformation from the sphere was found. Furthermore, it has been found that an effect is exhibited even in an image forming environment in which an external additive selectively adheres to a carrier newly replenished in the developing device by the trickle developing method, and the charging performance of the carrier is concerned. It is.

  Hereinafter, the present invention will be specifically described.

The present invention forms a full-color image through a process of developing an electrostatic latent image formed on a photoreceptor using at least yellow toner, magenta toner, and cyan toner. The lightness L ^* _Y when the toner image formed with only yellow toner takes the maximum saturation is in the range of 80 to 90, preferably in the range of 85 to 90. Further, the lightness L ^* _M when the toner image formed only with magenta toner takes the maximum saturation is in the range of 35 to 51, preferably in the range of 40 to 49. Further, the lightness L ^* _C when the toner image formed only with cyan toner takes the maximum saturation is in the range of 53 to 70, preferably in the range of 57 to 67.

The lightness L ^* of each single color toner image is defined by the L ^* a ^* b ^* system color system. Here, the L ^* a ^* b ^* system color system is one of means used to express a color numerically. L ^* is a coordinate in the z-axis direction and represents lightness, and a ^* and b ^* are coordinates of the x-axis and the y-axis, respectively, and both represent hue and saturation. Note that lightness refers to the relative brightness of colors, hue refers to shades of red, yellow, green, blue, purple, etc., and saturation refers to the degree of color vividness. , Defined by the following equation (1).

That is, the saturation C ^* is a distance from the coordinate point (a, b) and the origin O, and is calculated from the following equation.

Formula (1): Saturation C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2
In the L ^* a ^* b ^* color system, the color tone can be explained by the concept of hue angle. Here, the hue angle h is, for example, a half connecting a certain coordinate point (a, b) and the origin O on the x-axis-y-axis plane representing the relationship between hue and saturation when the lightness takes a certain value. The straight line is the angle formed by the straight line extending in the + direction (red direction) of the x axis in the counterclockwise direction from the + direction (red direction) of the x axis, and is calculated by the following equation (2).

Formula (1): Hue angle h = tan ⁻¹ (b ^* / a ^* )
In the x-axis-y-axis plane, the-(minus) direction of the x-axis indicated by a ^* is the green direction, and the + (plus) direction of the y-axis indicated by b ^* is the yellow direction. The-(minus) direction of the axis is the blue direction.

The maximum saturation referred to in the present invention is defined as follows. In general, when image formation is performed with toner containing a sufficient amount of colorant, the saturation of the formed toner image tends to increase as the toner adhesion amount on the transfer paper increases. However, when the toner adhesion amount exceeds a certain level, the increase in saturation changes to a stagnation and finally decreases. As described above, there is a case where the saturation of the formed toner image changes from rising to falling even though the toner adhesion amount is increasing, and the saturation at this time is defined as the maximum saturation. In addition, the amount of adhesion is measured by weighing an unfixed patch image of 20 mm × 50 mm together with the transfer paper, and then blow-off with an air gun until the transfer toner cannot be visually confirmed, and the remaining transfer paper is weighed again and transferred. Obtain the toner mass. Then, the toner adhesion amount per unit area is calculated by dividing the mass of the blown-off toner by the patch area. The transfer paper used for the adhesion amount measurement is gloss paper for electrophotography having a basis weight of 128 g / m ² , for example, “POD gloss coated paper” manufactured by Oji Paper Co., Ltd.

  On the other hand, when the toner adhesion amount and saturation maintain a proportional relationship as in the case of setting in the image forming apparatus, the toner adhesion amount on the transfer paper is maximized under the setting conditions of the image forming apparatus. The saturation of time is defined as the maximum saturation.

Specifically, L ^* a ^* b ^* for calculating the saturation C ^* and the hue angle h is measured using a spectrophotometer “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth). As with the measurement of the reflection spectrum, a D65 light source is used as the light source, a φ4 mm reflection measurement aperture is used, the measurement wavelength range is 380 to 730 nm at 10 nm intervals, the viewing angle (observer) is 2 °, and white is used exclusively for reference adjustment. This is done under conditions using tiles.

The relationship between the toner adhesion amount and the saturation can be correlated by measuring the saturation of the toner image formed corresponding to each toner adhesion amount based on the gradation evaluation patch of “ECI2002 image data”. . In addition, the transfer paper used when measuring the saturation and the lightness is one having a basis weight of 128 g / m ² and a lightness of 93. For example, “POD gloss coated paper” manufactured by Oji Paper Co., Ltd. is there. The fixing condition of the toner image when measuring the saturation and the brightness is the standard fixing condition of the image forming apparatus used in the present invention. Further, the glossiness of the toner image when measuring the saturation and lightness is determined by measuring the glossiness of 75 ° using “Gloss Meter (manufactured by Murakami Color Research Laboratory)”, and at least the glossiness of 10 or more. It is measured.

The maximum saturation of a toner image formed only with yellow toner will be described. In the present invention, from the viewpoint of secondary colors formed using yellow toner, that is, green and red, the maximum chroma C ^* _Y of a toner image formed only with yellow toner is 85 to 115. preferable. Here, the maximum saturation of the yellow toner single color image is defined as follows.
(1) When the content of the toner colorant is set to be large, the saturation increases almost proportionally with the increase in the toner adhesion amount. However, if the content exceeds a certain level, the saturation increases even if the adhesion amount increases. It stops and it starts to decline. The saturation at which the saturation changes from rising to falling even though the toner adhesion amount is rising is defined as the maximum saturation in this case.
(2) When the toner adhesion amount is proportional to the saturation, the saturation of the toner image when the toner adhesion amount on the transfer paper that can be set by the image forming apparatus is maximized is defined as the maximum saturation in this case. .

The maximum saturation of yellow is measured at a hue angle of 75 degrees. At this time, the lightness of the yellow image is preferably set so that the lightness L ^* _Y is in the range of 80 to 90 when the yellow toner single color image has the maximum saturation from the viewpoint of green and red color development. ^* Set so that _Y is in the range of 85-90.

Next, the maximum saturation of a toner image formed only with magenta toner will be described. In the present invention, from the viewpoint of secondary colors formed using magenta toner, that is, blue and red, the maximum chroma C ^* _M of a toner image formed only with magenta toner is 70 to 100. preferable. Here, the definition of the maximum saturation of the magenta toner single color image is the same as that performed for the yellow toner single color image.

The maximum saturation of magenta is measured at a hue angle of 315 degrees. At this time, the lightness of the magenta image is preferably such that the lightness L ^* _M is in the range of 35 to 51 when the magenta toner single color image has the maximum saturation from the viewpoint of color development of blue, purple, and red. , L ^* _M is set in the range of 40-49.

Next, the maximum saturation of a toner image formed only with cyan toner will be described. In the present invention, from the viewpoint of secondary colors formed using cyan toner, that is, green and blue, the maximum chroma C ^* _C of a toner image formed only with cyan toner is 50 to 80. preferable. Here, the definition of the maximum saturation of the cyan toner monochromatic image is the same as that performed for the yellow toner monochromatic image.

Note that the maximum saturation of cyan is measured at a hue angle of 195 degrees. At this time, the lightness of the cyan image is preferably set so that the lightness L ^* _C is in the range of 53 to 70 when the cyan toner single-color image has the maximum saturation, from the viewpoint of yellow-green, green, and blue color development. Is set so that L ^* _C is in the range of 57-67.

  In the present invention, when a toner image formed only of yellow, magenta, and cyan toners has the maximum saturation and the lightness is within the range described above, the trickle is developed while supplying new toner and carrier. A stable full-color image can be formed by the development of the system. In other words, even if a carrier spent phenomenon occurs in which a toner external additive adheres to the newly replenished carrier surface and lowers the charging performance of the carrier, a full color image with a predetermined image quality can be stabilized without causing fluctuations in density and color tone. Can be produced. Further, it has become possible to stably produce a full-color image having a predetermined image quality without causing image defects such as image blurring and fogging in a halftone region on the full-color image.

  As a result, according to the present invention, the image quality of a secondary color halftone toner image formed using a plurality of types of color toners is remarkably improved. As a result, high-quality images that are comfortable to the eyes can be created. In addition, since the amount of reflected light of the image is increased, the secondary color reproduction region can be expanded. Furthermore, as the amount of reflected light of the image increases, a rich contrast can be obtained not only for the black toner but also for the dark image formed by overlapping the yellow, magenta and cyan images.

Next, when a toner image formed only of yellow toner, magenta toner, and cyan toner has the maximum saturation, the lightness L ^* _Y , L ^* _M , and L ^* _C are within the above-described ranges. Will be described.

1. Yellow Toner First, a yellow toner that realizes the lightness L ^* _Y will be described.

In the present invention, when a toner image formed only of yellow toner takes the maximum saturation using a trickle-type developing method that develops an electrostatic latent image formed on a photoreceptor while supplying new toner and a carrier. The brightness L ^* _Y is in the range of 80 to 90.

  The yellow toner capable of realizing this is preferably one containing at least one yellow colorant shown in the following group X and group Y as a colorant, for example.

That is, for the colorant for yellow toner that achieves the lightness L ^* _Y , a dispersion liquid such as the following is mixed to adjust the reflection spectrum in the range of the following relational expressions (11) to (14). This work does not give the person skilled in the art much trial and error.

That is, by preparing a colorant particle dispersion for yellow toner and using a colorant whose reflection spectrum satisfies the following relational expressions (11) to (14), a yellow toner image having the lightness L ^* _Y in the above range is used. A yellow toner is formed.

Here, the reflection spectrum of the yellow monochromatic toner image is measured using a spectrophotometer “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth). Measurement conditions were as follows: a D65 light source as a light source, a φ4 mm reflection measurement aperture, a measurement wavelength range of 380 to 730 nm with an interval of 10 nm, a viewing angle (observer) of 2 °, and a dedicated white tile for reference alignment. is there. The single color toner image for the reflection spectrum is formed using transfer paper having a basis weight of 128 g / m ² and a lightness of 93. As an example, “POD gloss coated paper” manufactured by Oji Paper Co., Ltd. is used, and the glossiness of the image is determined by measuring 10 or more. The glossiness of the toner image is measured by using “Gloss Meter (manufactured by Murakami Color Engineering Laboratory)” with a glossiness of 75 degrees. Further, when forming a toner image, the fixing condition is the standard fixing condition of the image forming apparatus.

Relational expression (11) 2 ≦ A ₄₁₅ + A ₄₆₀ ≦ 24
[Wherein, A ₄₁₅ represents the reflectance (unit:%) at a wavelength of 415 nm, and A ₄₆₀ represents the reflectance (unit:%) at a wavelength of 460 nm. ]
Relational expression (12) 20 ≦ A ₅₁₀ −A ₄₉₀ ≦ 40
[Wherein, A ₅₁₀ represents the reflectance (unit:%) at a wavelength of 510 nm, and A ₄₉₀ represents the reflectance (unit:%) at a wavelength of 490 nm. ]
Relational expression (13) 2 ≦ A ₅₅₀ −A ₅₃₀ ≦ 16
Relational expression (14) 70 ≦ A ₅₅₀
[In the formula, A ₅₅₀ represents the reflectance (unit:%) at a wavelength of 550 nm, and A ₅₃₀ represents the reflectance (unit:%) at a wavelength of 530 nm. ]
The yellow colorants belonging to Group X and Group Y are as follows. That is,
[Group X]; I. Pigment yellow 3, C.I. I. Pigment yellow 35, C.I. I. Pigment yellow 65, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 98, C.I. I. Pigment Yellow 111
[Group Y]; I. Pigment yellow 9, C.I. I. Pigment yellow 36, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 181, C.I. I. Pigment Yellow 153
Particularly preferred is a yellow toner in which the mass ratio of the yellow colorant selected from the group X and the yellow colorant selected from the group Y is 65:35 to 95: 5.

2. Next, a magenta toner that realizes the lightness L ^* _M will be described.

In the present invention, when a toner image formed only with magenta toner takes the maximum saturation using a trickle-type developing method that develops an electrostatic latent image formed on a photoreceptor while supplying new toner and a carrier. The brightness L ^* _M is in the range of 35 to 51.

  As a magenta toner capable of realizing this, for example, there are magenta toners containing the following pigments, dyes, and complex compounds as colorants, and 1 to 30% of general-purpose pigments are included in the colorants shown below. A magenta colorant having a relatively strong bluish color is used.

That is, for the colorant for magenta toner that achieves the lightness L ^* _M , a dispersion such as the following is mixed to adjust the reflection spectrum in the range of the following relational expressions (21) to (24). This work does not give the person skilled in the art much trial and error.

That is, by preparing a colorant particle dispersion for magenta toner and using a colorant whose reflection spectrum satisfies the following relational expressions (21) to (24), a magenta toner image having the lightness L ^* _M in the above range. A magenta toner for forming the toner is realized.

Relational expression (21) 30 ≦ B ₄₅₀ −B ₅₂₀ ≦ 85
[In the formula, B ₄₅₀ represents the reflectance (unit:%) at a wavelength of 450 nm, and B ₅₂₀ represents the reflectance (unit:%) at a wavelength of 520 nm. ]
Relational expression (22) 1 ≦ B ₅₃₀ + B ₅₇₀ ≦ 25
[Wherein, B ₅₃₀ represents the reflectance (unit:%) at a wavelength of 530 nm, and B ₅₇₀ represents the reflectance (unit:%) at a wavelength of 570 nm. ]
Relational expression (23) 2 ≦ B ₆₇₀ −B ₆₀₀ ≦ 50
Relational expression (24) 80 ≦ B ₆₇₀
[In the formula, B ₆₇₀ represents the reflectance (unit:%) at a wavelength of 670 nm, and B ₆₀₀ represents the reflectance (unit:%) at a wavelength of 600 nm. ]
The measurement of the reflection spectrum of the magenta toner image is performed under the same conditions as the measurement of the reflection spectrum of the yellow toner image described above.

Specific examples of the pigment include the following. That is,
C. I. Pigment Red 2, 3, 6, 7, 15, 15, 16, 48: 1, 48: 3, 53: 1, 57: 1, 122, 123, 123, 139 144, 149, 166, 177, 178, 208, 208, 209, 222, etc.

Specific examples of the dye include the following. That is,
C. I. Solvent Red 3, 14, 17, 18, 22, 23, 49, 51, 53, 87, 127, 128, 131, 145, 146, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 176, 179 and the like.

  The present inventor has found that the following is preferable for the magenta toner as a preferred embodiment of the invention described in claim 1.

  That is, as described in the second aspect, it has been found that the magenta toner preferably contains a compound represented by the following general formula (1).

R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₇ in the formula each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁₅ and R ₁₆ each independently represent a hydrogen atom or 1 carbon atom. Or it represents the alkyl group of 2. M and n represent an integer of 1 or 2, and (X ⁻ ) represents a counter anion that represents a chlorine ion or a sulfonic acid compound ion.

  Further, as described in the third aspect, it has been found that the magenta toner preferably contains a compound represented by the following general formula (2).

In the formula, each R ₂₁ independently represents a hydrogen atom or a substituent, R ₂₂ represents —NR ₂₄ R ₂₅ or —OR ₂₆ , and R ₂₃ represents a hydroxyl group, an alkoxy group, an aryloxy group, an amino group, an amide group, or an alkylsulfonylamino group. Represents any group of an arylsulfonylamino group. _Also, A 11 _{to A 13} is intended to represent each independently _{-CR 27} = or -N =.

In the formula, X ₁₁ is an atomic group necessary for forming a 5- or 6-membered aromatic ring or heterocyclic ring, and Z ₁ is required for forming a 5- or 6-membered heterocyclic ring containing at least one nitrogen atom. An atomic group that may have a substituent may form a condensed ring with the substituent. R _{24 to} R ₂₇ each independently represent a hydrogen atom or a substituent, L ₁₁ represents a linking group having 1 or 2 carbon atoms or a part of a ring structure, and is bonded to R ₂₃ to form a 5- or 6-membered ring structure. It may be formed. p represents an integer of 0 to 3.

  Specific examples of the compound represented by the general formula (1), which is one of preferable colorants for magenta toners, include the following.

  Specific examples of the compound represented by the general formula (2), which is one of the preferred colorants for the magenta toner, include those shown below.

  The compound represented by the general formula (2) acts as a colorant in the form of a complex compound as shown in complex compounds 1 and 2 below.

  As shown in Examples described later, among the above-described magenta colorants, compounds (1) -25, compounds (1) -26, mixtures of complex compounds 1 and 2, and the like are preferably used.

3. Cyan Toner Next, a cyan toner that realizes the lightness L ^* _C will be described.

In the present invention, when a toner image formed only of cyan toner takes the maximum saturation using a trickle-type developing method that develops an electrostatic latent image formed on a photoreceptor while supplying new toner and a carrier. The lightness L ^* _C is in the range of 53 to 70.

  As a preferable mode for realizing the invention of the first aspect, a cyan toner containing a silicon phthalocyanine compound represented by the following general formula (3) can be cited.

Z in the formula independently represents a hydroxy group, a chlorine group, an aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or a group represented by the following general formula (3-1). Is. A ^{1 to} A ⁴ represent benzene rings.

R ⁶¹ , R ⁶² , and R ⁶³ in the formula are each an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or an aryloxy group having 6 to 18 carbon atoms. Is expressed. R ⁶¹ , R ⁶² and R ⁶³ may be the same group or different groups.

As the colorant for cyan toner that achieves the lightness L ^* _C , for example, a dispersion of a silicon phthalocyanine compound represented by the general formula (3) is reflected in the range of the following relational expressions (31) to (34). This operation does not give the person skilled in the art much trial and error.

That is, by preparing a colorant particle dispersion for cyan toner and using a colorant whose reflection spectrum satisfies the following relational expressions (31) to (34), a cyan toner image having a lightness L ^* _C in the above range. A cyan toner capable of forming a toner is realized.

Relational expression (31) 4 ≦ | C ₄₈₀ −C ₄₅₀ | ≦ 16
[Wherein, C ₄₈₀ represents the reflectance (unit:%) at a wavelength of 480 nm, and C ₄₅₀ represents the reflectance (unit:%) at a wavelength of 450 nm. ]
Relational expression (32) 15 ≦ C ₅₅₀ −C ₅₇₀ ≦ 35
Relational expression (33) 20 ≦ C ₅₇₀ ≦ 50
[Wherein, C ₅₅₀ represents the reflectance (unit:%) at a wavelength of 550 nm, and C ₅₇₀ represents the reflectance (unit:%) at a wavelength of 570 nm. ]
Relational expression (34) 0 ≦ C ₆₂₀ + C ₆₅₀ ≦ 30
[Wherein, C ₆₂₀ represents the reflectance (unit:%) at a wavelength of 620 nm, and C ₆₅₀ represents the reflectance (unit:%) at a wavelength of 650 nm. ]
The measurement of the reflection spectrum of the cyan toner image is performed under the same conditions as the measurement of the reflection spectrum of the yellow toner image described above.

As a preferred embodiment of the cyan toner that realizes the lightness L ^* _C , as described above, a toner containing the silicon phthalocyanine compound represented by the general formula (3) as a colorant can be mentioned. In the silicon phthalocyanine compound represented by the general formula (3), a silicon atom (Si) is used as a metal atom (hereinafter also referred to as a central metal atom) located at the center of the phthalocyanine ring.

Z in the general formula (3) is independently a hydroxy group, chlorine, an aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or the following general formula (3- It represents a compound represented by 1). In the general formula (3-1), R ⁶¹ , R ⁶² and R ^{63 each} represents an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or An aryloxy group having 6 to 18 carbon atoms is shown. Here, R ⁶¹ , R ⁶² , and R ⁶³ may be the same group or different groups. These groups preferably have 1 to 10 carbon atoms, more preferably 2 to 8 carbon atoms. In the general formula (3), A ¹ , A ² , A ³ and A ⁴ each independently represent a benzene ring.

  The silicon phthalocyanine compound represented by the general formula (3) is a phthalocyanine compound having an axial ligand called a tetraazaporphine compound in which a silicon atom is used as a central metal atom. Here, the axial ligand is represented by Z in the general formula (3).

  A toner containing the compound represented by the general formula (3) can exhibit better color reproducibility than a toner containing a phthalocyanine compound having no axial ligand. This is presumed to be because the compound represented by the general formula (3) has a more complicated structure than the phthalocyanine compound having no axial ligand, and the compound is less likely to aggregate and crystallize. As a result, it is considered that the color reproducibility is improved by maintaining the uniform dispersion of the colorant in the toner particles and the fixed image.

  Further, the phthalocyanine compound represented by the general formula (3) is incorporated into the toner particles in a uniformly dispersed state in the toner manufacturing process because of the structure that is difficult to aggregate and crystallize. This is thought to contribute to the expansion of the reproduction range.

  That is, in the full-color image forming method according to the present invention, the color tone reproduction region using the cyan toner is expanded by using the cyan toner containing the compound represented by the general formula (3). In particular, the reproduction of the blue color tone formed by the magenta toner and the cyan toner, which has been difficult to reproduce in the prior art, can be stably performed by the magenta toner and the cyan toner described above. As a result, the reproducibility of a hue region called blue violet, which has been considered to be particularly difficult in reproducing the color tone of a display display image, can be greatly improved.

Z constituting the compound represented by the general formula (3) is preferably a group represented by the general formula (3-1) among the groups described above. R ⁶¹ , R ⁶² and R ⁶³ in the group represented by the general formula (3-1) are preferably an alkyl group having 1 to 6 carbon atoms, an aryl group or an alkoxy group, particularly an n-propyl group, Isopropyl group, n-butyl group, isobutyl group and t-butyl group are preferred. R ⁶¹ , R ⁶² and R ⁶³ may be the same group or different groups.

  The cyan toner preferably used in the present invention can be used alone or in combination of two or more of the phthalocyanine compounds. The content of the phthalocyanine compound in the toner is set in the range of 1 to 30% by mass, preferably 2 to 20% by mass with respect to the whole toner. In particular, since the above compound is expected to have high molecular light absorbency, it is expected to have the possibility of exhibiting the effects of the present invention even if the addition amount is small.

  Specific examples of the tetraazaporphine compound (phthalocyanine compound having an axial ligand) represented by the general formula (3) are shown in Table 1, and are represented by the general formula (3) usable for the toner according to the present invention. The compounds are not limited to those shown in Table 1.

  Examples of the cyan toner preferably used in the full-color image forming method according to the present invention include those containing the above-mentioned phthalocyanine as a colorant, but a cyan toner using the following known cyan colorant in combination with the above phthalocyanine is also preferable. Used. For example, in addition to the above phthalocyanine, C.I. I. And cyan toner using a known cyan colorant such as CI Pigment Blue 15.

  Moreover, as a coloring agent used in combination with the silicon phthalocyanine compound mentioned above in the present invention, there is a compound represented by the following general formula (II).

R ₂ constituting the above structural formula represents a hydrogen atom or an organic group. Specific examples of the compound represented by the general formula (II) include the following.

  Next, a trickle-type developing method used in the full-color image forming method according to the present invention will be described.

  In the present invention, when developing an electrostatic latent image formed on a photoreceptor using a developer, development is performed while replenishing toner and carrier into a developing device from a replenishment developer container containing toner and carrier. A trickle-type developing method is used. That is, when developing the electrostatic latent image formed on the photoreceptor, new toner is replenished corresponding to the toner consumed by the development, and new carriers are replenished to gradually remove the carriers in the developing device. We are updating and developing while suppressing deterioration due to long-term use of the carrier. In this way, by updating the carrier while forming an image, for example, by performing printing at the level of 100,000 sheets, all the carriers initially stored in the developing device are discharged to a new one. It is supposed to be updated.

  FIG. 2 is a cross-sectional view of a typical trickle developing device. The trickle-type developing device that can be used in the present invention is not limited to the arrangement shown in FIG. Further, in the trickle-type developing device shown in FIG. 2, the replenishment developer containing container containing the toner and the carrier in the present invention is not shown. The full-color image forming method according to the present invention includes, for example, loading a trickle-type developing device 4 shown in FIG. 2 for each color of yellow, magenta, cyan, and black into a full-color image forming device shown in FIG. Is to be done.

  The developing device 4 for each color contains a two-component developer of yellow (Y), magenta (M), cyan (C), and black (K), respectively, and is predetermined with respect to the peripheral surface of the photosensitive drum 10. Toner is supplied to the photosensitive drum 1 through the developing sleeves 41 arranged at intervals.

  The developing device 4 in FIG. 2 includes the following. Reference numeral 40 denotes a housing for storing a two-component developer composed of toner and carrier, 42 denotes a magnet roller having a fixed magnetic pole, 41 denotes a developing sleeve in which the magnet roller 42 is disposed, and 43 denotes development formed on the developing sleeve 41. A layer thickness regulating member for regulating the agent layer to a predetermined thickness, 44 is a developer receiving member, 48 is a developer removing plate, 45 is a conveyance supply roller, and 46 and 47 are a pair of stirring screws.

  The developing sleeve 41 is a cylindrical member made of, for example, stainless steel, and is arranged at a predetermined distance from the peripheral surface of the photosensitive drum 10, and with respect to the rotation of the photosensitive drum 10 (clockwise rotation in FIG. 2). It rotates in the reverse direction (clockwise rotation in FIG. 2).

  The magnet roller 42 is contained in the developing sleeve 41 and fixed concentrically with the developing sleeve 41. By alternately arranging a plurality of magnetic poles N1, N2, N3, S1, and S2, the magnet roller 42 is placed on the circumferential surface of the nonmagnetic sleeve. Apply magnetic force.

  The layer thickness regulating member 43 faces the magnetic pole N3 of the magnet roller 42 and is disposed at a predetermined interval from the developing sleeve 41. The layer thickness keeping regulating member 43 is made of, for example, a rod-like or plate-like magnetic stainless material, and regulates the layer thickness of the two-component developer on the peripheral surface of the developing sleeve 41.

  The receiving member 44 is disposed at a predetermined distance from the developing sleeve 41 on the downstream side in the rotation direction of the developing sleeve 41, and the developer layer is separated from the developing sleeve 41 so that the toner does not spill from the developer layer regulated by the layer thickness regulating member 43. It keeps the top stable. The receiving member 44 is made of a nonmagnetic member such as ABS resin, and is disposed adjacent to the end face of the layer thickness regulating member 43, so that it can be integrated with the layer thickness regulating member 43.

  The developer removing plate 48 is provided to face the magnetic pole N2 of the magnet roller 42, and develops from above the developing sleeve 41 by the action of the repulsive magnetic fields of the magnetic poles N2 and N3 and the magnet plate 48a provided on the back surface of the removing plate 48. The agent is removed.

  The transport supply roller 45 transports the developer removed by the removal plate 48 to the stirring screw 46 and supplies the developer stirred by the stirring screw 46 to the layer thickness regulating member 43. 45A constituting the conveyance supply roller 45 is a blade portion for conveying the developer.

  The agitating screws 46 and 47 rotate at a constant speed in opposite directions to agitate and mix the toner and the carrier accommodated in the developing device 4 and disperse them evenly.

  In trickle-type development, development is performed while replenishing toner and carrier. However, replenishment of toner and carrier to the housing 40 is performed by using a top plate 40A constituting the upper portion of the housing 40 provided above the stirring screw 47. The toner supply port H is used. The replenished toner and carrier are agitated and mixed with the developer already contained in the housing 40 by the agitating screws 146 and 147 that rotate at opposite speeds in opposite directions to become a developer having a uniform toner concentration. . The developer is conveyed to the layer thickness regulating member 43 by the conveyance supply roller 45, has a predetermined layer thickness by the layer thickness regulating member 43, and the outer peripheral surface of the developing sleeve 41 as a developer layer of a two-component developer by the receiving member 44. Supplied on top.

  The developer developed from the latent image formed on the photosensitive drum 10 is removed from the developing sleeve 41 by the action of the repulsive magnetic fields of the magnetic poles N2 and N3 and the magnet plate 48a provided on the back surface of the removing plate 48, and is conveyed. It is conveyed again to the stirring screw 146 by the supply roller 45.

  The developer 4 shown in FIG. 2 is supplied with a developer, that is, supplied with toner T and carrier C from a supply developer container (not shown). The supply of the toner T is performed when the toner concentration detection sensor 49 detects that the toner concentration in the housing 40 is lower than a predetermined toner concentration. Further, the supply of the carrier C is performed in a timely manner based on, for example, the integrated amount of printed sheets. The toner T supplied to the developing device 4 is supplied from a toner T supply means, a hopper (not shown) constituting the replenishment developer container referred to in the present invention, to a later-described top plate 40A via a developer transport path (not shown). The developing device 4 is replenished from the replenishing port H provided. Similarly, the carrier C supplied to the developing device 4 also passes through a developer conveyance path (not shown) from a carrier C supply means and a hopper (not shown) constituting the replenishment developer container referred to in the present invention. The developing device 4 is replenished from a replenishing port H provided in the plate 40A.

  The top plate 40A is provided with a replenishment port H (TC) of a developer conveyance path for merging and conveying the toner T and the carrier C on the surface located at the conveyance upstream end of the stirring screw 47. Yes. By arranging the members in this manner, the newly replenished toner T or carrier C is sufficiently agitated by the agitation screws 46 and 47, and the replenished toner T is charged by agitation and conveyed and supplied to the developing sleeve 41. The

  The toner T replenished from a hopper (not shown) is replenished in an amount similar to the toner T consumed by development, but the carrier C replenished from the hopper (not shown) is not consumed. This increases the amount of the developer. Correspondingly, a detection means for detecting the amount of developer D accommodated in the housing 40 is provided. When the detection means detects that the amount of developer D accommodated exceeds a specified amount, an excess amount is detected. The developer D is discharged from the housing 40. In FIG. 2, the detection means and the discharge means are not shown.

  From the replenishment developer container referred to in the present invention, a replenishment developer in which toner and carrier are mixed at a toner content concentration of 60% by mass to 98% by mass, preferably 80% by mass to 96% by mass. From the viewpoint of image density stability. On the other hand, the developer contained in the developing device 4 has a toner concentration of 3% to 12% by mass, preferably 5% to 9% by mass, from the viewpoint of image density stability. . The replenishment developer is stored in the replenishment developer storage container with the developer having the above-mentioned toner-containing concentration, and in addition to supplying the developer, the toner and the carrier are separated and stored. The specification which mixes both in a developing device may be used. As described above, the toner and carrier are separated from each other while being stored in the replenishment developer container. For example, a low-temperature fixing toner having a glass transition temperature of 30 ° C. or lower, or a carrier binding It is suitable for storage of toner containing a colorant that is compatible with the resin.

  In the trickle type developing apparatus usable in the present invention, an alternating voltage is applied to the developing sleeve 41 by applying an AC voltage to the developing sleeve 41, and the toner is transferred onto the photosensitive drum 1 via a magnetic brush formed in the developing area. Is supplied for development. The distance between the developing sleeve 41 and the photosensitive drum 1 is preferably, for example, 100 to 1000 μm from the viewpoint of preventing adhesion of the carrier constituting the magnetic brush to the photosensitive member and improving dot image reproducibility. In this way, by setting the distance between the two, a predetermined amount of toner is supplied to the photoconductor, and the magnetic brush is present in the development area at an appropriate density, thereby maintaining good print production. Preferred above.

  In order to realize sufficient image density, excellent dot reproducibility, and prevention of carrier adhesion to the surface of the photoreceptor, the contact width between the magnetic brush formed on the developing sleeve 41 and the photoreceptor drum 1 ( It is preferable to adjust the developing contact portion) to about 3 to 8 μm, for example. As a method for adjusting the developing contact portion, for example, there is a method of adjusting a distance between the layer thickness regulating member 43 and the developing sleeve 41, a method of adjusting a distance between the photosensitive drum 1 and the developing sleeve 41, or the like. Further, the developing device 4 of FIG. 2 is provided with a scraping blade 48 b that scrapes off the developer supplied with toner to the photosensitive drum 1 from the image forming developing sleeve 41 so that a new developer can be constantly supplied onto the developing sleeve 41. It may be.

  The alternating electric field formed in the development region is preferably set to a voltage of 300 to 3000 V and a frequency of 500 to 10,000 Hz, for example, from the viewpoint of stabilizing the image density. The AC bias waveform for forming the alternating electric field includes, for example, a triangular wave, a rectangular wave, a sine wave, or a waveform with a changed duty ratio. In order to cope with a change in the toner image forming speed, it is preferable to perform development by applying a developing bias voltage (intermittent alternating voltage) having a discontinuous AC bias voltage to the developing sleeve 41. By setting the alternating electric field voltage within the above range, for example, a sufficient image density can be obtained. Further, it is preferable because there is no possibility of fogging in the non-image area and there is no possibility of disturbing the latent image by the magnetic brush. Further, by setting the frequency within the above range, for example, the toner can stably follow the electric field, which is preferable in realizing good image quality.

  Under the conditions as described above, in the present invention, when developing the electrostatic latent image formed on the photosensitive member, the toner consumed by the development is supplied into the developing device, and the carrier is also in the developing device. The so-called trickle-type development for replenishing is performed. Even when there are many opportunities for supplying toner and carrier, as in the case of producing prints on the level of several thousand sheets, the configuration of the present invention realizes full-color image formation with good image quality without density fluctuations and image defects. Can do. The full-color image forming apparatus shown in FIG. 1 on which the trickle developing device can be mounted will be described later.

  Next, the two-component developer used in the present invention will be described. In the full-color image forming method according to the present invention, a two-component developer composed of the toner and the carrier is used.

  Examples of the carrier used in the two-component developer used in the present invention include magnetic materials made of known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead. Particles can be used, and ferrite particles are particularly preferable. As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a binder type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like can also be used.

  The coating resin constituting the coat carrier is not particularly limited, and examples thereof include polyolefin resins, polystyrene resins, styrene-acrylic copolymer resins, silicone resins, polyester resins, and fluorine resins. . Further, the binder resin constituting the binder type carrier is not particularly limited, and a known one can be used. For example, a styrene-acrylic copolymer resin, a polyester resin, a fluorine resin, a phenol resin, or the like can be used. it can.

  The carrier preferably has a volume-based median diameter of 20 to 100 μm, more preferably 20 to 60 μm, from the viewpoint of obtaining a high-quality image and suppressing the occurrence of carrier fog. By using the carrier having the volume-based median diameter, a magnetic brush with uniform spikes is formed on the developing sleeve 41, and a uniform image quality can be obtained when a solid image is formed. In addition, the developer is imparted with appropriate fluidity, and a stable charge rising performance is also exhibited. Furthermore, since the magnetic brush formed on the developing sleeve 41 has an appropriate height, it is possible to stably form a good image quality without the possibility of uneven developer sweeping.

  The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser. When measuring the volume-based median diameter of the carrier by this method, preparation is performed according to the following procedure. First, a developer, a small amount of neutral detergent, and pure water are added to a beaker, and these are thoroughly blended. The supernatant is discarded while applying a magnet to the bottom of the beaker. Furthermore, pure water is added and the supernatant liquid is discarded, whereby the toner and neutral detergent are removed to separate only the carrier. The separated carrier is dried at 40 ° C. to obtain a carrier alone.

  Preferred carriers include, for example, a coated resin using a silicone resin, a copolymer resin of an organopolysiloxane and a vinyl monomer (graft copolymer resin), or a polyester resin as a coating resin. Among them, a coated carrier coated with a resin obtained by reacting an isocyanate with a copolymer resin (graft copolymer resin) of an organopolysiloxane and a vinyl monomer has durability, environmental stability and Particularly preferred from the viewpoint of spent resistance. The vinyl monomer used for the formation of the coat carrier is a monomer having a substituent such as a hydroxyl group reactive with isocyanate.

  The two-component developer used in the present invention can be prepared by mixing the above-described toner and carrier. The mixing ratio of the carrier and the toner is preferably 3 to 12% by mass, more preferably 5 to 9% by mass in the developer in the developing device. The replenishment developer preferably has a toner concentration of 60 to 98% by mass, and more preferably 80 to 96% by mass from the viewpoint of image density stability.

  As a mixing device for mixing the carrier and the toner, for example, known mixing devices such as a Henschel mixer, a Nauter mixer, a V-type mixer, and a turbula mixer can be used. Among these, a Henschel mixer is preferable.

  The coated carrier preferably used in the two-component developer used in the present invention can be produced by forming a resin coating layer on the surface of the magnetic particles by a known method.

  The resin coating layer can be formed on the surface of the magnetic particles by a known dry method, wet method (solvent coating method, solvent immersion method) or the like, and among these, the dry method is preferable from the viewpoint of production cost and environmental load. Here, the dry method is a method in which a thermoplastic carrier particle (binder resin) and a magnetic particle are heated and mixed without using a liquid such as a solvent to form a resin coating layer on the surface of the magnetic particle to produce a coated carrier. is there.

  The wet method is a method of forming a coated carrier by forming a resin coating layer on the surface of magnetic particles using a solvent. In the solvent coating method, which is one of the wet methods, a coated carrier is prepared by coating the surface of magnetic particles with a coating solution obtained by dissolving a binder resin for forming a resin coating layer in a solvent to form a resin coating layer. Is.

  Next, the structure of the yellow, magenta, and cyan toners used in the full color image forming method according to the present invention will be described.

  The yellow toner, magenta toner, and cyan toner used in the present invention preferably have a volume reference median diameter (D50v) of 3 μm or more and 8 μm or less. By setting the volume reference median diameter in the above range, for example, it is possible to faithfully reproduce a very minute dot image at a level of 1200 dpi (dpi; number of dots per inch (2.54 cm)).

  By setting the volume reference median diameter of the yellow toner, magenta toner, and cyan toner used in the present invention within the above-described range, it is possible to form a fine toner image required for producing a photographic image, a fine line image, and the like. In this way, a fine dot image produced by digital image formation is faithfully reproduced, so a high-definition image equivalent to or higher than the printed image can be obtained, so it may be superior to the printed image without taking the trouble of making a plate. It is possible to provide a high-quality full-color print that is not inferior.

  Further, when the particle diameter of the color toner is in the above range, a change in color tone is suppressed regardless of the amount of toner adhesion, and excellent color reproducibility can be obtained. On the other hand, when the particle size of the color toner is less than 3.0 μm in terms of volume-based median diameter, light scattering is likely to occur, and a halftone image formed with a small amount of toner attached and a toner attached with a large amount of toner are formed. There is a risk that the color tone will differ from the solid image. Specifically, a halftone image formed only with color toners may have a bluish hue.

  In the case where the color toner particles are formed by a polymerization method, the particle size of the toner is controlled by the concentration and addition amount of the flocculant, the aggregation time, and further the composition of the polymer itself in the color toner production method. be able to.

  The volume-based median diameter (D50v diameter) of the toner can be measured and calculated using an apparatus in which a computer system for data processing is connected to “Multisizer 3 (manufactured by Beckman Coulter)”.

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is injected into a beaker containing “ISOTONII (manufactured by Beckman Coulter)” in the sample stand with a pipette until the measured concentration reaches 5 to 10%, and the measured particle count is set to 25,000. And measure. In addition, the aperture diameter of the multisizer 3 is 50 μm, and integration is performed from the larger particle volume, and the particle diameter of 50% is set as the volume-based median diameter.

  Further, the yellow toner, magenta toner, and cyan toner used in the present invention preferably have a coefficient of variation (CV value) in the volume-based particle size distribution of 2% to 21%, preferably 5% to 15%. More preferably.

  The coefficient of variation (CV value) in the volume-based particle size distribution represents the degree of dispersion in the particle size distribution of the toner particles on the volume basis, and is defined by the following equation.

CV value (%) = (standard deviation in number particle size distribution) / (median diameter (D50v) in number particle size distribution) × 100
A smaller CV value indicates a sharper particle size distribution, which means that the toner particles have the same size. In other words, since toners with uniform sizes can be obtained, it is possible to reproduce a fine dot image and fine lines required for digital image formation with higher accuracy. Further, when printing a photographic image, it is possible to create a high-quality photographic image of an image level made with printing ink or higher by using small-diameter toner having a uniform size.

  Further, with respect to individual color toner particles constituting the color toner used in the present invention, an average value of circularity (also referred to as “average circularity”) represented by the following formula is 0.930 from the viewpoint of improving transfer efficiency. It is preferably ˜1.000, more preferably 0.950 to 0.995.

Formula: Average circularity = peripheral length of circle determined from equivalent circle diameter / perimeter length of projected particle image The toner softening point temperature (Tsp) is preferably 70 ° C. or higher and 110 ° C. or lower, preferably 70 ° C. or higher. What becomes 100 degrees C or less is more preferable. The colorant used in the toner has a stable property in which the spectrum does not change even under the influence of heat, but the effect of heat applied to the toner during fixing by setting the softening point in the above range Can be further reduced. Therefore, since it becomes possible to form an image without imposing a burden on the colorant, it is expected to express a wider and more stable color reproducibility.

  In addition, by setting the softening point temperatures of yellow, magenta, and cyan toners within the above range, yellow, magenta, and cyan toners can be appropriately melted in the fixing process, and a secondary color image having high color reproducibility can be obtained. Can be formed.

  Here, “appropriate melting state of yellow, magenta, and cyan toner” means that when a color image is formed by superimposing toner images of other colors on each toner image formed of yellow, magenta, and cyan toner. A state in which the yellow, magenta, and cyan colorants contained in the toner image formed with the yellow, magenta, and cyan toners and the colorants constituting the other colors are both uniformly dispersed and colored. Specifically, for example, when a yellow toner image and a magenta toner image are overlaid, the interface between the binder resin layers disappears while being a color image fixed in a color superimposed state on the recording material. Thus, a state in which the yellow colorant and the magenta colorant are uniformly dispersed is realized. At this time, the magenta colorant and the yellow colorant are not exuded in an area outside the color image area.

  Further, by setting the softening point of the toner within the above range, the toner image can be fixed at a temperature lower than that of the prior art, and an environment-friendly image formation with reduced power consumption can be performed.

The softening point of the toner can be controlled by, for example, the following methods alone or in combination. That is,
(1) The type and composition ratio of monomers used for resin formation are adjusted.
(2) The molecular weight of the resin is adjusted according to the type and amount of chain transfer agent.
(3) Adjust the type and amount of wax.

The softening point temperature of the toner is measured as follows. First, in an environment of 20 ° C. and 50% RH, 1.1 g of color toner is put in a petri dish and flattened, and left for 12 hours or more, and then a molding machine “SSP-10A (manufactured by Shimadzu Corporation)”. Is pressed with a force of 3820 kg / cm ² for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm.

  Next, this molded sample was subjected to a load of 196 N (20 kgf), a starting temperature of 60 ° C., and a preheating time of 300 seconds using a flow tester “CFT-500D (manufactured by Shimadzu Corporation)” in an environment of 24 ° C. and 50% RH. Extruding from a cylindrical die hole (1 mm diameter x 1 mm) using a piston with a diameter of 1 cm from the end of preheating under the condition of a heating rate of 6 ° C / min, and an offset value of 5 mm by the melting temperature measurement method of the heating method The offset method temperature Toffset measured with the setting is set as the softening point temperature of the color toner.

  Next, a method for producing yellow toner, magenta toner, and cyan toner used in the present invention will be described.

  The toner used in the present invention is composed of particles (hereinafter also referred to as colored particles) containing at least a resin and a colorant. The colored particles constituting the toner used in the present invention are not particularly limited, and can be produced by a conventional toner production method. That is, a toner manufacturing method by a so-called pulverization method in which a toner is prepared through kneading, pulverization, and classification steps, or a so-called polymerized toner in which a polymerizable monomer is polymerized and at the same time particle formation is performed while controlling the shape and size. It can be produced by applying a production method (for example, an emulsion polymerization method, a suspension polymerization method, a polyester elongation method, etc.).

  Next, the resin, wax, etc. constituting the yellow toner, magenta toner, and cyan toner used in the present invention will be described with specific examples.

  First, the resin that can be used for the toner is not particularly limited, but a polymer formed by polymerizing a polymerizable monomer called a vinyl monomer described below is representative. Is something. The polymer constituting the resin is composed of a polymer obtained by polymerizing at least one polymerizable monomer, and is composed of these vinyl monomers singly or in combination. It is.

Specific examples of vinyl polymerizable monomers are shown below.
(1) Styrene or styrene derivatives Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, etc. (2) Methacrylate derivatives Methyl methacrylate, methacryl Ethyl acetate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethyl methacrylate (3) Acrylic acid ester derivatives Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc. (4) Olefins Ethylene, propylene, isobutylene, etc. (5) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc. (6) Vinyl ether (7) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc. (8) N-vinyl compounds N-vinyl carbazole, N-vinyl indole (9) Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, etc. As the polymerizable monomer, those having an ionic dissociation group shown below can be used. In particular, the colorant of the present invention has weak alkalinity as described above, and the one having an ionic dissociation group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group in the side chain of the monomer is used. Further, the dispersibility in the resin can be further improved, which is preferable. Specifically, there are the following.

  First, those having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. Examples of those having a sulfonic acid group include styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, and examples of those having a phosphoric acid group include acid phosphooxyethyl methacrylate.

  Moreover, it is also possible to produce a resin having a crosslinked structure by using the following polyfunctional vinyls. Specific examples of polyfunctional vinyls are shown below.

  Divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and the like.

Next, as the wax used in the toner that can be used in the present invention, there are known waxes as shown below.
(1) Polyolefin wax Polyethylene wax, polypropylene wax, etc. (2) Long chain hydrocarbon wax, paraffin wax, sazol wax, etc. (3) Dialkyl ketone wax, distearyl ketone, etc. (4) Ester wax Carnauba wax, Montan Wax, trimethylolpropane tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerol tribehenate, 1,18-octadecanediol di Stearate, trimellitic trimellitic acid, distearyl maleate, etc. (5) Amide wax Ethylenediamine dibehenyl amide, trimellitic acid triste The melting point of Riruamido such as wax is usually from 40 to 125 ° C., preferably from 50 to 120 ° C., more preferably from 70 to 90 ° C.. By setting the melting point within the above range, the heat-resistant storage stability of the toner is ensured, and stable toner image formation can be performed without causing cold offset or the like even when fixing at a low temperature. Further, the wax content in the toner is preferably 1% by mass to 30% by mass, and more preferably 5% by mass to 20% by mass.

  Next, the yellow toner, magenta toner, and cyan toner used in the present invention include inorganic fine particles and organic fine particles having a number average primary particle size of 4 to 800 nm as external additives (= external additives) in the production process. It can be added to make a toner.

  By adding the external additive, the fluidity and chargeability of the toner are improved, and the cleaning property is improved. The type of the external additive is not particularly limited, and examples thereof include the following inorganic fine particles, organic fine particles, and lubricants.

  As the inorganic fine particles, conventionally known fine particles can be used. For example, silica, titania, alumina, strontium titanate fine particles and the like are preferable. Moreover, what hydrophobized these inorganic fine particles as needed can also be used.

  Specific examples of the silica fine particles include commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150 manufactured by Hoechst, H -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5, etc. manufactured by Cabot Corporation.

  As the titania fine particles, for example, commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. Specifically, homopolymers such as styrene and methyl methacrylate and copolymers thereof can be used.

  Further, a lubricant can be used to further improve the cleaning property and transfer property, and examples thereof include the following higher fatty acid metal salts. That is, salts of zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, salts of manganese, iron, copper, magnesium, etc., zinc palmitate, salts of copper, magnesium, calcium, etc., linoleic acid There are salts of zinc, calcium and the like, and zinc and calcium of ricinoleic acid.

  The addition amount of these external additives and lubricants is preferably 0.1 to 10.0% by mass with respect to the whole toner. In addition, these external additives and lubricants can be added using various known mixing devices such as a Turbula mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.

  Next, an example of an image forming apparatus capable of performing the full color image forming method according to the present invention will be described. FIG. 1 is a schematic view showing an example of an image forming apparatus capable of forming a full-color image while performing the above-described trickle development using a two-component developer.

  In FIG. 1, 1Y, 1M, 1C and 1K are photoreceptors, 4Y, 4M, 4C and 4K are trickle-type developing devices (developing means), 5Y, 5M, 5C and 5K are primary transfer means as primary transfer means. Rolls 5A are secondary transfer rolls as secondary transfer means, 6Y, 6M, 6C and 6K are cleaning devices, 7 is an intermediate transfer member unit, 24 is a heat roll type fixing device, and 70 is an intermediate transfer member.

  This image forming apparatus is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, an endless belt-shaped intermediate transfer body unit 7 as a transfer unit, and a recording member P. It has an endless belt-like paper feeding and conveying means 21 for conveying and a heat roll type fixing device 24 as a fixing means. A document image reading device SC is disposed above the main body A of the image forming apparatus.

  An image forming unit 10Y that forms a yellow image as one of the different color toner images formed on each photoconductor is arranged around a drum-shaped photoconductor 1Y as the first photoconductor and the photoconductor 1Y. The charging unit 2Y, the exposure unit 3Y, the developing unit 4Y, the primary transfer roll 5Y as the primary transfer unit, and the cleaning unit 6Y are provided. The image forming unit 10M that forms a magenta image as another different color toner image includes a drum-shaped photoconductor 1M as a first photoconductor, and a charge disposed around the photoconductor 1M. Means 2M, exposure means 3M, developing means 4M, primary transfer roll 5M as primary transfer means, and cleaning means 6M. In addition, an image forming unit 10C that forms a cyan image as one of toner images of different colors is a drum-shaped photoconductor 1C as a first photoconductor, and a charge disposed around the photoconductor 1C. Means 2C, exposure means 3C, developing means 4C, primary transfer roll 5C as primary transfer means, and cleaning means 6C.

  Further, the image forming unit 10K that forms a black image as one of the other different color toner images includes a drum-shaped photoconductor 1K as a first photoconductor, and a charge disposed around the photoconductor 1K. Means 2K, exposure means 3K, trickle developing means 4K, primary transfer roll 5K as primary transfer means, and cleaning means 6K.

  The endless belt-like intermediate transfer body unit 7 has an endless belt-like intermediate transfer body 70 as an intermediate transfer endless belt-like second image carrier that is wound around a plurality of rolls and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10K is sequentially transferred and synthesized on the rotating endless belt-shaped intermediate transfer body 70 by the primary transfer rolls 5Y, 5M, 5C, and 5K. A color image is formed. A recording member P such as a sheet as a transfer material accommodated in the sheet feeding cassette 20 is fed by the sheet feeding / conveying means 21, passes through a plurality of intermediate rolls 22 A, 22 B, 22 C, 22 D, and a registration roll 23, and is secondary. A color image is transferred onto the recording member P at a time by being conveyed to a secondary transfer roll 5A as a transfer means. The recording member P to which the color image has been transferred is fixed by the heat roll type fixing device 24, is sandwiched by the paper discharge roll 25, and is placed on the paper discharge tray 26 outside the apparatus.

  On the other hand, after the color image is transferred to the recording member P by the secondary transfer roll 5A, the residual toner is removed by the cleaning unit 6A from the endless belt-shaped intermediate transfer body 70 in which the recording member P is separated by curvature.

  During the image forming process, the primary transfer roll 5K is always in pressure contact with the photoreceptor 1K. The other primary transfer rolls 5Y, 5M, and 5C are in pressure contact with the corresponding photoreceptors 1Y, 1M, 1C, and 1R, respectively, only during color image formation.

  The secondary transfer roll 5A comes into pressure contact with the endless belt-shaped intermediate transfer body 70 only when the recording member P passes through the secondary transfer roll 5A and secondary transfer is performed.

  In this manner, toner images are formed on the photoreceptors 1Y, 1M, 1C, 1R, and 1K by charging, exposure, and development, and the toner images of the respective colors are superimposed on the endless belt-shaped intermediate transfer body 70 and recorded collectively. The image is transferred to the member P and fixed by the fixing device 24 by pressure and heating. The photoreceptors 1Y, 1M, 1C, and 1K after transferring the toner image to the recording member P are subjected to the above-described charging, exposure, and development cycle after the toner remaining on the photoreceptor is removed by the cleaning device 6A. The next image formation is performed.

  In addition, the fixing method that can be performed by the image forming method according to the present invention is not particularly limited, and can be handled by a known fixing method. Known fixing methods include a roller fixing method comprising a heating roller and a pressure roller, a fixing method comprising a heating roller and a pressure belt, a fixing method comprising a heating belt and a pressure roller, and a heating belt and a pressure belt. Belt fixing method and the like, and any method may be used. As a heating method, a heating method such as a halogen lamp method or an IH fixing method can be employed.

  The recording material that can be used in the full-color image forming method according to the present invention is a support capable of holding a color toner image. Specifically, various types of support such as coated paper such as plain paper, fine paper, art paper, or coated paper from thin paper to thick paper, commercially available Japanese paper or postcard paper, plastic film for OHP, cloth, etc. The body can be mentioned, but is not limited thereto.

  Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. The volume-based median diameter of the yellow colorant fine particles was measured under the following measurement conditions using “MICROTRAC UPA 150” (manufactured by HONEWELL).

〔Measurement condition〕
Sample refractive index: 1.59
Sample specific gravity: 1.05 (in terms of spherical particles)
Solvent refractive index: 1.33
Solvent viscosity: 0.797 (30 ° C), 1.002 (20 ° C)
Zero point adjustment: Ion exchange water was put in the measurement cell.

1. Preparation of Colorant Fine Particle Dispersion Used for Toner Preparation “Yellow Colorant Fine Particle Dispersion 1 Used for Making“ Yellow Toner 1-20 ”,“ Magenta Toner 1-20 ”, and“ Cyan Toner 1-20 ” To 20 "," magenta colorant fine particle dispersions 1 to 20 ", and" cyan colorant fine particle dispersions 1 to 20 "were prepared by the following procedure.

(1) Preparation of “Yellow Colorant Fine Particle Dispersion 1” A solution in which 11.5 parts by mass of sodium n-dodecyl sulfate was stirred and dissolved in 160 parts by mass of ion-exchanged water was stirred, and the following yellow was added to the solution. Colorant was added slowly.

C. I. Pigment Yellow 74 22.5 parts by mass C.I. I. Pigment Yellow 83 2.5 parts by mass Next, dispersion processing is performed using a stirrer “CLEARMIX W Motion CLM-0.8” (manufactured by M Technique Co., Ltd.), whereby the volume-based median diameter is 126 nm. A yellow colorant fine particle dispersion 1 ”was prepared.

(2) Preparation of “Yellow Colorant Fine Particle Dispersion 2-20”, “Magenta Colorant Fine Particle Dispersion 1-20”, “Cyan Colorant Fine Particle Dispersion 1-20” “Yellow Colorant Fine Particle Dispersion 1” “Yellow colorant fine particle dispersions 2 to 20” were prepared by the same procedure except that the type and addition amount of the yellow colorant were changed as shown in Table 2. The same procedure was used except that a magenta colorant was used in place of the yellow colorant used in the preparation of “yellow colorant fine particle dispersion 1” and the type and amount of the magenta colorant were changed as shown in Table 3. To prepare “magenta colorant fine particle dispersions 1 to 20”. Further, the same procedure was followed except that a cyan colorant was used instead of the yellow colorant used in the preparation of “yellow colorant fine particle dispersion 1”, and the type and amount of the cyan colorant were changed as shown in Table 4. "Cyan colorant fine particle dispersions 1 to 12" were prepared.

2. 2. Preparation of resin particles for toner preparation 2-1. Production of “core-forming resin particle 1” [Production of “core-forming resin particle 1”]
“Core-forming resin fine particles 1” were prepared by the following procedure.

(1) First-stage polymerization A reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device is charged with 4 parts by mass of an anionic surfactant (Structural Formula 1) represented by the following Structural Formula 1 by ion-exchanged water 3040. A surfactant solution dissolved in parts by mass was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

(Structural Formula 1) C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ SO ₃ Na
To this surfactant solution, an initiator solution in which 10 parts by mass of a polymerization initiator (potassium persulfate: KPS) is dissolved in 400 parts by mass of ion-exchanged water is added to a temperature of 75 ° C. The monomer mixture was added dropwise over 1 hour.

Styrene 532 parts by weight n-butyl acrylate 200 parts by weight Methacrylic acid 68 parts by weight n-octyl mercaptan 16.4 parts by weight After dropwise addition of the monomer mixture, the system was heated and stirred at 75 ° C. for 2 hours. Polymerization (first stage polymerization) was performed to prepare resin fine particles. This is designated as “resin fine particles A1”.

(2) Second stage polymerization (formation of intermediate layer)
Prepare the monomer mixture by adding the following compounds in a flask equipped with a stirrer,
Styrene 101.1 parts by mass n-butyl acrylate 62.2 parts by mass Methacrylic acid 12.3 parts by mass n-octyl mercaptan 1.75 parts by mass
After adding 93.8 parts by mass of paraffin wax “HNP-57” (manufactured by Nippon Seiki Co., Ltd.), the mixture was heated to 80 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 3 parts by mass of the anionic surfactant represented by the structural formula 1 is dissolved in 1560 parts by mass of ion-exchanged water is heated to 80 ° C., and the “resin fine particles” are added to the surfactant solution. The dispersion of “A1” was added in an amount of 32.8 parts in terms of solid content. After the addition, the monomer solution in which the release agent is dissolved is mixed and dispersed for 8 hours by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified having a dispersed particle size of 340 nm. A dispersion containing the particles was prepared.

  Next, an initiator solution in which 6 parts by mass of potassium persulfate is dissolved in 200 parts by mass of ion-exchanged water is added to the dispersion, and this system is heated and stirred at 80 ° C. for 3 hours to perform polymerization (second Step polymerization) to obtain a dispersion of resin fine particles.

(3) Third stage polymerization (formation of outer layer)
An initiator solution prepared by dissolving 5.45 parts by mass of potassium persulfate in 220 parts by mass of ion-exchanged water is added to the dispersion of “resin fine particles A2” obtained as described above, and a temperature condition of 80 ° C. Below, the monomer liquid mixture which consists of the following compound was dripped over 1 hour.

Styrene 293.8 parts by mass n-butyl acrylate 154.1 parts by mass n-octyl mercaptan 7.08 parts by mass After completion of the dropwise addition of the monomer mixture, polymerization is performed by heating and stirring for 2 hours (third stage polymerization). Then, it was cooled to 28 ° C. to produce “core forming resin fine particles 1”. The “core-forming resin fine particles A” produced by the third stage polymerization had a glass transition temperature (Tg) of 28.1 ° C.

[Production of “core forming resin fine particles B”]
(1) First stage polymerization (formation of core particles)
The following compound was added to a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, and heated to 80 ° C. to dissolve it to obtain a polymerizable monomer solution.

Styrene 115.9 parts by mass n-butyl acrylate 47.4 parts by weight Methacrylic acid 12.3 parts by weight Paraffin wax “HNP-57” (manufactured by Nippon Seiki Co., Ltd.) 93.8 parts by weight A surfactant solution was prepared by dissolving 2.9 parts by mass of an anionic surfactant in 1340 parts by mass of ion-exchanged water, and this was heated to 80 ° C. and charged into the reaction vessel.

(Structural Formula 2) C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na
Thereafter, the mixture dispersion treatment is performed for 2 hours by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and a dispersion containing emulsified particles (oil droplets) having a dispersed particle diameter of 245 nm is obtained. Prepared.

  Next, after adding 1460 parts by mass of ion-exchanged water, 6.1 parts by mass of a polymerization initiator (potassium persulfate: KPS) and 1.8 parts by mass of n-octyl mercaptan were dissolved in 237 parts by mass of ion-exchanged water. The initiator solution was added to adjust the temperature to 80 ° C. Thereafter, this system was heated and stirred at 80 ° C. for 3 hours to carry out polymerization (first stage polymerization) to prepare a dispersion of resin fine particles. This is designated as “resin fine particle B1”.

(2) Second stage polymerization (formation of outer layer)
An initiator solution prepared by dissolving 3.8 parts by mass of a polymerization initiator (potassium persulfate: KPS) in 148 parts by mass of ion-exchanged water was added to the dispersion of “resin fine particles B1” produced as described above. Under a temperature condition of ° C., a monomer mixed solution composed of the following compounds was added dropwise over 1 hour.

Styrene 300.9 parts by weight n-butyl acrylate 146.9 parts by weight Methacrylic acid 3 parts by weight n-octyl mercaptan 4.93 parts by weight After completion of the dropping, polymerization is performed by heating and stirring for 2 hours (second stage polymerization). Then, it was cooled to 28 ° C. to obtain a dispersion of “core forming resin fine particles B”. The “core-forming resin fine particles B” had a glass transition temperature (Tg) of 36.0 ° C.

[Production of “core forming resin fine particles C”]
In the production of “core forming resin fine particles B”, the polymerizable monomer solution used in the first stage polymerization was changed to the following. That is,
Styrene 135.9 parts by mass n-Butyl acrylate 27.4 parts by mass Methacrylic acid 12.3 parts by mass In addition, the initiator solution used in the first stage polymerization was changed to a polymerization initiator (potassium persulfate: KPS) 6.1 parts by mass. And 0.8 part by mass of n-octyl mercaptan were changed to those dissolved in 237 parts by mass of ion-exchanged water. Other than that, “core forming resin fine particles C” were prepared in the same procedure. The “core-forming resin fine particles C” had a glass transition temperature (Tg) of 42.6 ° C.

[Preparation of “core resin fine particle D”]
(1) First stage polymerization (formation of core particles)
A surfactant solution in which 4 parts by mass of the anionic surfactant represented by the structural formula 2 is dissolved in 3040 parts by mass of ion-exchanged water is charged into a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction device. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution in which 10 parts by mass of a polymerization initiator (potassium persulfate: KPS) is dissolved in 400 parts by mass of ion-exchanged water is added to a temperature of 75 ° C. The monomer mixture was added dropwise over 1 hour.

Styrene 528 parts by weight n-butyl acrylate 204 parts by weight Methacrylic acid 68 parts by weight n-octyl-3-mercaptopropionic acid ester 24.4 parts by weight After the dropwise addition of the monomer mixture, the system is kept at 75 ° C. for 2 hours. The mixture was heated and stirred for polymerization (first stage polymerization) to prepare resin fine particles. This is designated as “resin fine particle D1”.

(2) Second stage polymerization (formation of intermediate layer)
Prepare the monomer mixture by adding the following compounds in a flask equipped with a stirrer,
Styrene 95 parts by weight n-butyl acrylate 36 parts by weight Methacrylic acid 9 parts by weight n-octyl-3-mercaptopropionate 0.69 parts by weight Paraffin wax “HNP-57 ( (Manufactured by Nippon Wax Co., Ltd.) "77 parts by mass was added, and the mixture was heated to 90 ° C and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 1 part by mass of the anionic surfactant represented by the structural formula 2 is dissolved in 1560 parts by mass of ion-exchanged water is heated to 98 ° C., and the “resin fine particles” are added to the surfactant solution. 28 parts by mass of the dispersion of “D1” in terms of solid content was added. After the addition, the monomer solution in which the release agent is dissolved is mixed and dispersed for 8 hours by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified having a dispersed particle size of 284 nm. A dispersion containing the particles was prepared.

  Next, an initiator solution in which 5 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added to this dispersion, and this system was heated and stirred at 98 ° C. for 12 hours for polymerization (second polymerization). Stepwise polymerization) was performed to obtain a dispersion of “resin fine particles D2.”

(3) Third stage polymerization (formation of outer layer)
An initiator solution in which 6.8 parts by mass of potassium persulfate is dissolved in 265 parts by mass of ion-exchanged water is added to the dispersion of “resin fine particles D2” obtained as described above, and the temperature condition at 80 ° C. Below, the monomer liquid mixture which consists of the following compound was dripped over 1 hour.

Styrene 242.5 parts by mass n-butyl acrylate 96.5 parts by mass Methacrylic acid 18 parts by mass n-octyl-3-mercaptopropionate 8.0 parts by mass Heating for 2 hours after completion of the dropwise addition of the monomer mixture Polymerization (third stage polymerization) was carried out by stirring and then cooled to 28 ° C. to produce “core-forming resin fine particles D”. The “core-forming resin fine particles D” produced by the third stage polymerization had a glass transition temperature (Tg) of 52.3 ° C.

[Production of “core resin fine particles E”]
In the production of “core forming resin fine particles B”, the polymerizable monomer solution used in the second stage polymerization (formation of the outer layer) was changed to the following. That is,
Styrene 135.9 parts by mass n-butyl acrylate 27.4 parts by mass Methacrylic acid 12.3 parts by mass In addition, the initiator solution used in the first stage polymerization was used as a polymerization initiator (potassium persulfate: KPS) 5.1 parts by mass. The part was changed to one dissolved in 197 parts by mass of ion-exchanged water. Other than that, “core forming resin fine particles E” were prepared by the same procedure. The “core-forming resin fine particles E” had a glass transition temperature (Tg) of 9.2 ° C.

2-2. Preparation of “shell resin fine particles 1” In the preparation of the above “core resin fine particles 1”, the monomer mixed solution used in the first stage polymerization was changed to the following compound and added amount. The procedure is the same except that
Styrene 624 parts by weight 2-ethylhexyl acrylate 120 parts by weight Methacrylic acid 56 parts by weight n-octyl mercaptan 16.4 parts by weight Polymerization reaction and post-reaction treatment were performed to produce “shell resin fine particles F”. The “shell resin fine particles F” had a glass transition temperature (Tg) of 62.6 ° C.

3. 3. Production of “Yellow Toner 1-20”, “Magenta Toner 1-20”, “Cyan Toner 1-12” 3-1. Preparation of “Yellow Toner 1” (1) Formation of Core Particles In a reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device,
420.7 parts by mass of “core resin fine particle 1” dispersion (converted to solid content)
900 parts by mass of ion-exchanged water “Yellow colorant fine particle dispersion 1” 200 parts by mass was added and stirred. After adjusting the temperature in the container to 30 ° C., 5 mol / liter sodium hydroxide aqueous solution was added to this solution to adjust the pH to 8-11.

  Next, an aqueous solution obtained by dissolving 2 parts by mass of magnesium chloride hexahydrate in 1000 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, the temperature was raised and the system was heated to 65 ° C. over 60 minutes. In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II” (manufactured by Beckman Coulter), and when the volume-based median diameter (D50) became 5.5 μm, sodium chloride 40. An aqueous solution in which 2 parts by mass was dissolved in 1000 parts by mass of ion-exchanged water was added to stop the particle size growth. Further, as a ripening treatment, the fusion was continued by heating and stirring at a liquid temperature of 70 ° C. for 1 hour to form “core particles 1”. When the circularity of the obtained “core particle 1” was measured by “FPIA2100” (manufactured by Sysmex Corporation), the average circularity was 0.912.

(2) Formation of Shell Layer Next, 96 parts by mass (in terms of solid content) of dispersion of “shell resin fine particles 1” is added at 65 ° C., and 2 parts by mass of magnesium chloride hexahydrate is added to 1000 parts by mass of ion-exchanged water. The aqueous solution dissolved in the part was added over 10 minutes. After the addition, the temperature is raised to 70 ° C. (shelling temperature), stirring is continued for 1 hour, and “shell resin fine particles 1” are fused to the surface of “core particles 1” and then aged at 75 ° C. for 20 minutes. Processing was performed to form a shell layer.

  Here, 40.2 parts by mass of sodium chloride was added, cooled to 30 ° C. under conditions of 6 ° C./min, the produced colored particles were filtered, washed repeatedly with ion-exchanged water at 45 ° C., and then heated to 40 ° C. By drying with warm air, “Yellow Toner 1” having a shell layer formed on the core particle surface was obtained. The types and ratios of the yellow colorant used in “Yellow Toner 1” are as shown in Table 2 above.

3-2. Preparation of “Yellow Toners 2 to 20” “Core forming resin fine particles 1” and “yellow colorant fine particle dispersion 1” used in the preparation of “Yellow Toner 1” are respectively shown in Table 3 below. “Yellow toners 2 to 20” were prepared by the same procedure except that the fine particles and the yellow colorant fine particle dispersion were changed. Table 5 shows the types and ratios of the yellow colorants used for the production of “yellow toners 1 to 20”, the maximum saturation of the toner image, the brightness at the maximum saturation, and the reflectance at each predetermined wavelength. Table 6 shows the core-forming resin fine particles constituting each toner, the glass transition temperature, the weight average molecular weight, and the softening point temperature of each toner.

3-3. Preparation of “Magenta Toner 1-20” In the preparation of “Yellow Toner 1”, “Yellow Colorant Fine Particle Dispersion 1” was changed to “Magenta Colorant Fine Particle Dispersion 1-20” shown in Table 3 above. “Magenta toners 1 to 20” were prepared by the same procedure. Table 7 shows the types and ratios of the magenta colorants used in the produced “magenta toners 1 to 20”, the maximum saturation of the toner image, the brightness at the maximum saturation, and the reflectance at each predetermined wavelength. Table 8 shows the core-forming resin fine particles constituting each toner, the glass transition temperature, the weight average molecular weight, and the softening point temperature of each toner.

3-4. Production of “Cyan Toner 1-12” In the production of “Yellow Toner 1”, “Yellow Colorant Fine Particle Dispersion 1” was changed to “Cyan Colorant Fine Particle Dispersion 1-12” shown in Table 4 above. “Cyan toners 1 to 12” were prepared by the same procedure. Table 9 shows the types and ratios of the cyan colorants used for the produced “cyan toners 1 to 12”, the maximum saturation of the toner image, the brightness at the maximum saturation, and the reflectance at each predetermined wavelength. Table 10 shows the core-forming resin fine particles constituting each toner, the glass transition temperature, the weight average molecular weight, and the softening point temperature of each toner.

4). Preparation of developer 4-1. Production of “Carriers 1-5” (1) Production of “Carrier 1” (Preparation of carbon black (CB) dispersion)
First, 20 parts of carbon black “Mogul-L (manufactured by Cabot Corporation)” is dispersed with 100 parts of toluene using zirconia beads having a particle diameter of 0.5 mm for 4 hours at room temperature, followed by filtration. A carbon black dispersion was prepared.

Next, ferrite particles of Fe ₂ O ₃ / MnO / MgO (content ratio: 50/10/40) having a number average primary particle size of 40 μm were prepared as the conductive core material.

  Furthermore, a silicone resin (trade name: SR-2411, solid content concentration: 20% by mass, manufactured by Toray Dow Corning Silicone Co., Ltd.) was prepared. After mixing 10% by mass of a silane coupling agent (N-phenyl-γ-aminopropylmethyltrimethoxysilane) with respect to the silicone resin solids, the carbon black dispersion was mixed with 5% by mass with respect to the silicone resin solids. After addition, a coating solution was prepared by dissolving in toluene.

  The coating solution is coated to 1% by mass with respect to the conductive core material (ferrite particles), further baked at 250 ° C. for 2 hours, cooled, and then treated with a vibration mill for 10 minutes to obtain “carrier 1”. Was made.

(2) Production of “Carrier 2” “Carrier 2” having a number average primary particle size of 40 μm was the same as that in the production of “Carrier 1” except that carbon black was not added to the coating layer forming coating solution. Was made.

(3) Production of “Carrier 3” Magnetite fine particles (specific resistance 4 × 10 ⁷ (Ω · cm), number average primary particle size 0.30 μm) and hematite fine particles (specific resistance 3 × 10 ⁸ (Ω · cm), The number average primary particle size 0.30 μm) was oleophilicized with 3- (2-aminoethylaminopropyl) trimethoxysilane. The amount of 3- (2-aminoethylaminopropyl) trimethoxysilane added was 3.2% by mass for the magnetite fine particles and 2.0% by mass for the hematite fine particles.

  Next, the following materials, 5 parts by mass of 28% by mass ammonia water and 10 parts by mass of pure water were charged into the flask, and the temperature was raised to 85 ° C. with stirring for 45 minutes, and a polymerization reaction was carried out for 3 hours.

Phenol 10 parts by mass Formaldehyde 37% by weight aqueous solution 10 parts by mass The above lipophilic magnetite fine particles 70 parts by mass The above lipophilic hematite fine particles 10 parts by mass Then, the mixture is cooled to 30 ° C., water is added, and the supernatant liquid is added. The precipitate was removed and washed with water, followed by air drying. After the air drying treatment, the magnetic material-containing resin carrier core was produced by reducing the pressure to 5 hPa or less and drying at 60 ° C. to disperse the magnetic fine particles.

  The magnetic material-containing resin carrier core was put into a coater, and after humidified nitrogen was introduced to adjust the moisture content to 0.3% by mass, the core surface was coated with a shear stress continuously applied. The coating liquid for coating is obtained by diluting a straight silicone resin and γ-aminopropyltrimethoxysilane with toluene. Coating treatment was performed while volatilizing the toluene solvent under a dry nitrogen stream, and 1.0% by mass of a straight silicone resin in which all the substituents were methyl groups and 0.015% by mass of γ-aminopropyltrimethoxysilane on the core surface. The mixture was coated.

  The coated magnetic material-containing resin carrier core was baked at 140 ° C., aggregates were removed with a 100 mesh sieve, and then the particle size distribution was adjusted by removing fine powder and coarse powder with a multi-division wind classifier. . Thereafter, humidity control was performed for 100 hours in a hopper maintained at 23 ° C. and 60% RH to prepare “Carrier 3”. “Carrier 3” had a number average primary particle size of 40 μm.

(4) Production of “Carrier 4” Conductive carbon having a specific surface area of 1270 m ² / g and alumina particles having an average particle diameter of 0.3 μm are each 5 masses with respect to the silicone resin “SR2411 (manufactured by Toray Dow Corning Silicone)”. The liquid prepared so as to be in a percentage was dispersed with a homogenizer for 30 minutes. The obtained dispersion is diluted so that the solid content concentration becomes 10% by mass, and an aminosilane coupling agent having the following structural formula is added to this dispersion so that the solid content becomes 3% by mass with respect to the solid content of the silicone resin. Then, a coating layer forming coating solution was prepared.

Aminosilane coupling agent; H ₂ N (CH ₂ ) ₃ Si (OCH ₃ ) ₃
Next, the coating solution for forming the coating layer was applied to the surface of the core material particles using a fluidized bed type coating device under a coating condition of 50 g / min in an atmosphere of 100 ° C. Furthermore, heat treatment was performed at 250 ° C. for 2 hours, and “Carrier 4” having a number average primary particle size of 40 μm was produced. In addition, when the component analysis of the core material particles used for the production of “Carrier 4” was performed, it was found that Fe ₂ O ₃ was 48.8 mol%, MnO was 48.7 mol%, and MgO was 2.5 mol%. It was a thing.

(5) Production of “Carrier 5” A material for coating layer formation was prepared by putting the following materials into toluene and stirring and dispersing them with a sand mill.

Covering layer magnetic particles (Mn—Ni ferrite, density 4.7 g / cm ³ , number average primary particle size 2 μm, saturation magnetization 66 emu / g, shape factor 115) 2 parts by mass Toluene 8 parts by mass Styrene-methyl methacrylate copolymer Copolymer (copolymerization ratio 20:80, number average molecular weight 85000) 4 parts by mass Carbon black “VXC-72 (manufactured by Cabot)” 0.1 part by mass Cross-linked melamine resin “Eposta S (manufactured by Nippon Shokubai Co., Ltd.)” 0 .1 part by mass The solution for forming the coating layer was vacuumed together with 100 parts by mass of ferrite particles (Mn—Mg ferrite, density 4.7 g / cm ³ , number average primary particle size 40 μm, saturation magnetization 60 emu / g, shape factor 119). The mixture was put into a degassing kneader and the temperature was kept at 60 ° C. and stirred for 10 minutes. Thereafter, the current value of the stirring motor was monitored and the pressure was reduced to distill off toluene. After the distillation, sieved with a sieve having an opening of 75 μm to prepare “Carrier 5” having a number average primary particle size of 40 μm.

4-2. Preparation of Developer (1) Preparation of “Yellow Developer 1” 9 parts by weight of “Yellow Toner 1” is added to 91 parts by weight of “Carrier 1”, and V-type mixer “V-20 (Seishin Enterprise) "Yellow developer 1", which is a two-component developer, was prepared.

(2) Preparation of “Yellow Developer 2-20”, “Magenta Developer 1-20”, “Cyan Developer 1-12” According to the above-mentioned preparation procedure of “Yellow Developer 1”, Table 11 described later As shown, "Yellow Developer 2-20", "Magenta Developer 1-20", and "Cyan Developer 1-12" were prepared by combining "Carriers 1-5" and each toner.

5. Evaluation Experiment The above-mentioned “yellow developer 1-20”, “magenta developer 1-20”, “cyan developer 1-12” are combined as shown in Table 11 to be described later, and a commercially available digital capable of trickle development. It was mounted on a printer “IRC3100 Black Station (manufactured by Canon Inc.)”. Then, after adjusting the initial image density to 1.40 under each image forming environment, continuous printing of 50,000 sheets was performed. Here, “Examples 1 to 13” are prints manufactured under the constituent requirements of the present invention, and “Prints of Comparative Examples 1 to 13” are prints manufactured under conditions that do not satisfy the constituent requirements of the present invention. 10 ". As shown in Table 11, “Comparative Example 10” was evaluated without performing trickle development.

  Evaluation is performed using an original document with an image area of 5% using A4 paper “CLC paper (manufactured by Canon Sales Co., Ltd.)” in a normal temperature and humidity environment (temperature 23 ° C., humidity 60% RH). 50,000 continuous prints were made. Further, the same continuous printing was performed under a normal temperature and low humidity environment (temperature 23 ° C., humidity 5% RH).

  The evaluation was performed for the following blue-violet image reproducibility evaluation, image density stability, and halftone image reproducibility.

<Evaluation of reproducibility of blue-violet images>
A patch image of seven blue-violet color codes is output on the following computer display, and a printed matter corresponding to the patch image is produced. It was determined what color the color tone of the produced printed matter could be identified.

The seven blue-purple color codes used for the evaluation are as follows. That is,
# 7f00ff, # 7700ef, # 7000e0, # 6800d1, # 6000c1, 5900b2, and # 5100a3. Evaluation was made as follows, and ◎ and ○ were accepted. That is,
(Evaluation criteria)
◎; 7 colors could be identified (excellent)
○: 4 or more and less than 7 colors could be identified (good)
X: Only less than 4 colors could be identified (defect).

The computer display conditions for displaying the patch images of the above seven blue-violet color codes are as follows. That is,
(Computer display condition)
・ Computer: iMAC (Apple Computer Co., Ltd.)
・ 24-inch wide screen liquid crystal display screen ・ Screen resolution: 1920 × 1200 pixels ・ 2.16 GHz Intel Core 2 Duo processor 1
・ 4MB shared L2 cache ・ 1GB memory (2 × 512MB SO-DIMM)
・ 250GB serial ATA hard drive 2
・ 8x double layer SuperDrive (DVD + R DL, DVD ± RW, CD-RW)
・ NVIDIA GeForce 7300 GT 128MB GDDR3 memory ・ AirMac Extreme and Bluetooth 2.0 built-in ・ Apple Remote
<Evaluation of image density stability>
The image density stability was evaluated by calculating the amount of change in image density before and after continuous printing of 50,000 sheets. For the image density before and after the continuous printing, the solid image portion density (initial image density is set to 1.40) output on the print image is set to a commercially available color reflection densitometer “X-Rite 404A (manufactured by X-Rite)”. ) ”Was measured 5 times, and the average value was taken as the image density. The density fluctuation difference before and after the continuous printing was evaluated as follows, and A and B were regarded as acceptable. That is,
(Evaluation criteria)
A: Good (density difference before and after continuous printing is less than 0.08)
B: Normal (density difference before and after continuous printing is 0.08 or more and less than 0.15)
C: Slightly bad (density difference between before and after continuous printing is 0.15 or more and less than 0.20)
D: Poor (density difference before and after continuous printing is 0.20 or more)
<Halftone image reproducibility>
Halftone image reproducibility was evaluated by calculating a halftone image density change amount before and after continuous printing of 50,000 sheets. The halftone image portion density (initial image density is set to 0.40) output on the print image is measured five times with a commercially available color reflection densitometer “X-Rite 404A (manufactured by X-Rite)”. The average value was defined as the image density. The density fluctuation difference before and after the continuous printing was evaluated as follows, and A and B were regarded as acceptable. That is,
(Evaluation criteria)
A: Good (density difference before and after continuous printing is less than 0.03)
B: Normal (density difference between before and after continuous printing is 0.03 or more and less than 0.05)
C: Slightly bad (density difference before and after continuous printing is 0.05 or more and less than 0.08)
D: Poor (density difference before and after continuous printing is 0.08 or more)
The results are shown in Table 11.

  As shown in Table 11, all of “Examples 1 to 13” having the configuration of the present invention have good results in the evaluation items of blue-violet image reproducibility evaluation, image density stability, and halftone image reproducibility. Obtained. On the other hand, “Comparative Examples 1 to 9” that do not satisfy the configuration of the present invention did not give good results in the evaluation items. In this way, even under the image forming conditions in which a large amount of new toner and carrier of 50,000 continuous prints are supplied, a color image having a good image quality can be obtained with the configuration of the present invention. An image with good image quality could not be obtained with the image having no color.

1 is a schematic diagram illustrating an example of a tandem type full-color image forming apparatus capable of two-component development type image formation. It is the schematic of the image development apparatus which can implement trickle development.

Explanation of symbols

1 (1Y, 1M, 1C, 1K) Photoconductor 2 (2Y, 2M, 2C, 2K) Charging device 3 (3Y, 3M, 3C, 3K) Exposure device 4 (4Y, 4M, 4C, 4K) Developing device 40 Housing 41 Developing sleeve 42 Magnet roll 45 Conveying and feeding roller 46, 47 Stirring screw 49 Toner density detection sensor 5 (5Y, 5M, 5C, 5K, 5A) Transfer roll 6 (6Y, 6M, 6C, 6K) Cleaning device 7 Intermediate transfer member Unit 70 Intermediate transfer member 10 (10Y, 10M, 10C, 10K) Image forming unit 24 Heat roll type fixing device H Supply port T Toner C Carrier

Claims (4)

A step of developing the electrostatic latent image formed on the photoreceptor using the developer while supplying the toner and the carrier into the developing device from the replenishment developer containing container containing the toner and the carrier. A full color image forming method comprising:
The full-color image forming method includes:
At least a full color image is formed using a developer composed of yellow toner and carrier, a developer composed of magenta toner and carrier, and a developer composed of cyan toner and carrier.
When the toner image formed with only the yellow toner has the maximum saturation, the lightness L ^* _Y is in the range of 80 to 90,
When the toner image formed only with the magenta toner has the maximum saturation, the lightness L ^* _M is in the range of 35 to 51,
A full-color image forming method, wherein a lightness L ^* _C is in a range of 53 to 70 when the toner image formed only of the cyan toner has maximum saturation. The full-color image forming method according to claim 1, wherein the magenta toner contains a compound represented by the following general formula (1).

[Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₇ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁₅ and R ₁₆ each independently represent a hydrogen atom or carbon number. 1 or 2 alkyl groups are represented. M and n represent an integer of 1 or 2, and (X ⁻ ) represents a counter anion and represents a chlorine ion or a sulfonic acid compound ion. ] The full-color image forming method according to claim 1, wherein the magenta toner contains a compound represented by the following general formula (2).

[In the formula, each R ₂₁ independently represents a hydrogen atom or a substituent, R ₂₂ represents —NR ₂₄ R ₂₅ or —OR ₂₆ , and R ₂₃ represents a hydroxyl group, an alkoxy group, an aryloxy group, an amino group, an amide group, an alkylsulfonylamino group. Represents any group of an arylsulfonylamino group. A ₁₁ to A ₁₃ each independently represent a _{-CR 27} = or -N =.
X ₁₁ is an atomic group necessary for forming a 5- or 6-membered aromatic ring or heterocyclic ring, Z ₁ is a substituent necessary for forming a 5- or 6-membered heterocyclic ring containing at least one nitrogen atom And a condensed ring may be formed by the substituent. R _{24 to} R ₂₇ each independently represents a hydrogen atom or a substituent, L ₁₁ represents a linking group having 1 or 2 carbon atoms or a part of a ring structure, and is bonded to R ₂₃ to form a 5- or 6-membered ring structure. May be. p represents an integer of 0 to 3. ] The full-color image forming method according to claim 1, wherein the cyan toner contains a compound represented by the following general formula (3).

[In the formula, each Z independently represents a hydroxy group, a chlorine group, an aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or a group represented by the following general formula (3-1). Show. A ^{1 to} A ⁴ represent a benzene ring. ]

[Wherein R ⁶¹ , R ⁶² , and R ⁶³ represent an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or an aryloxy group having 6 to 18 carbon atoms. Indicates a group. R ⁶¹ , R ⁶² and R ⁶³ may be the same group or different groups. ]

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