JP2012068437A - Cyan toner for electrostatic charge image development and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cyan toner having good hue and saturation and a wide color reproduction range.SOLUTION: The cyan toner for electrostatic charge image development comprises cyan toner particles containing at least a binder resin and a cyan colorant. The cyan colorant contains a phthalocyanine compound containing an axial ligand as a colorant. In the toner for electrostatic charge image development, dispersion particles of the phthalocyanine compound containing an axial ligand have a number average particle diameter of 5 nm or more and 50 nm or less, and the ligand metal is one of a silicon atom, a germanium atom and a tin atom.

Description

  The present invention relates to a cyan toner for developing electrostatic images and a method for producing the same, and more particularly to a cyan toner for developing electrostatic images used in an electrophotographic image forming apparatus and a method for producing the same.

  In recent years, in an image forming apparatus such as an electrophotographic copying machine or printer, an opportunity to form a full-color image in addition to a conventional monochrome image is increasing. Since the electrophotographic full-color image forming method does not require a printing plate, it can be easily produced as many times as necessary according to demand, and is widely used in the light printing field. .

  Even in the light printing field, particularly when full-color images such as catalogs and advertisements are formed, it is required to reproduce the hue of the original (original) more faithfully. However, the color reproduction range of a full color image that can be formed by a full color image forming method using an electrophotographic method is much narrower than the color reproduction range of a full color image that can be displayed on a television screen or a computer display. There is a problem that it is difficult to reproduce a full-color image displayed on a display on a transfer material such as paper with the same hue.

  In general, in a full-color image forming method using an electrophotographic method, color reproduction is performed using a combination of three color toners, yellow toner, magenta toner, and cyan toner. Since a color reduction method using a combination of colors is adopted, the color reproduction range is narrower and the brightness and saturation are inferior to full-color images obtained by additive methods such as TV images and computer displays. It was.

  Therefore, in the reproduction of a full-color image by the electrophotographic method, it is required that the basic color toners of the above three colors have high vividness, that is, saturation. Various attempts have been made in the past to expand the color reproduction range with a toner for developing an electrostatic image (hereinafter simply referred to as toner) used for electrophotographic image formation.

  Conventionally, for cyan toners, copper phthalocyanine pigments have been widely used as colorants. Copper phthalocyanine pigments are inexpensive, easy to obtain, stable, safe, and easy to use. However, when used as a pigment for cyan toner, the brightness tends to be low, and as a result, when a halftone dot image is formed, there is a problem that the image becomes rough and granular and lacks in homogeneity.

  In order to improve the drawbacks of this copper phthalocyanine pigment, a technique has been proposed in which an axial ligand-containing colorant compound X pigment is used as a colorant for cyan toner (see, for example, Patent Document 1). This has the effect of improving the hue of cyan toner and further expanding the color reproduction range of green and blue by using a silicon phthalocyanine pigment having high brightness and high saturation as a colorant for cyan toner.

JP 2009-75520 A

  Multi-coloring by adding conventional yellow toner, magenta toner, cyan toner, orange toner, green toner, etc. is effective in terms of expanding the color reproduction area. There were problems such as complications.

  On the other hand, the technology using the axial ligand-containing colorant compound X pigment as the toner colorant has a certain effect on the expansion of the color reproduction range by improving the brightness and saturation, but when dispersed in the toner. Due to the fact that it contains a binder resin and a release agent and because of the aggregation of the colorants, the color tone inherent to the pigment of the axial ligand-containing colorant compound X-based in terms of saturation, etc. I couldn't make full use of it.

  The present invention has been made to solve the above problems, that is, when a pigment of an axial ligand-containing colorant compound X is used as a colorant for cyan toner, the hue and saturation are good, and the color reproduction range. It is an object of the present invention to provide a cyan toner for developing an electrostatic image having a wide range.

The above-described problems of the present invention are solved by the following configuration.
1.
A cyan toner for developing an electrostatic charge image containing cyan toner particles containing at least a binder resin and a cyan colorant,
The cyan colorant contains an axial ligand-containing colorant compound X represented by the following general formula (1), and the axial ligand-containing colorant compound X in the cyan toner for electrostatic image development is A cyan toner for developing electrostatic images, wherein the number average particle diameter of dispersed particles is from 5 nm to 50 nm.

(In the general formula (1), M ¹ represents a group 14 metal atom. Further, two Qs each independently represents a monovalent substituent, and m and n are each 0 or 1, and at least One is 1. Also, four A's each independently represent an atomic group that forms an aromatic ring which may have a substituent.
2.
In the axial ligand-containing colorant compound X represented by the general formula (1), two Qs are each independently an alkyl group, an aryl group, an aryloxy group, an alkoxy group, an acyloxy group, or the following general formula ( 2. The cyan toner for developing electrostatic images according to 1 above, which is a compound group represented by 2).

(In the general formula (2), R ¹ , R ² and R ³ each independently represents an alkyl group, an aryl group, an aryloxy group or an alkoxy group.)
3.
In the axial ligand-containing colorant compounds X, M ¹ is Si, Ge, wherein the one or electrostatic image developing cyan toner according to the 2, characterized in that any of the elements Sn.
4).
4. The cyan toner for developing electrostatic images according to any one of 1 to 3 above, wherein in the axial ligand-containing colorant compound X represented by the general formula (1), M ¹ is Si. .
5.
5. The method for producing a cyan toner for developing an electrostatic charge image according to any one of 1 to 4,
The production method comprises dispersing at least the axial ligand-containing colorant compound X in an aqueous medium in the presence of a surfactant;
Producing a dispersion of resin fine particles;
A cyan toner for developing an electrostatic charge image, comprising: a step of aggregating and assembling an aqueous dispersion of the axial ligand-containing colorant compound X and a dispersion of the resin fine particles to produce toner base particles Production method.
6).
When the axial ligand-containing colorant compound X is dispersed in an aqueous medium, the median diameter (D ₅₀ ) in the number distribution of the dispersed particle diameter of the axial ligand-containing colorant compound X is 5 nm or more and 30 nm or less. 6. The method for producing a cyan toner for developing an electrostatic charge image as described in 5 above.

  By adopting the above-described configuration, the present invention can provide a cyan toner for developing an electrostatic charge image (hereinafter, also simply referred to as a cyan toner) having good hue and saturation and a wide color reproduction range. A full color image faithful to the original can be obtained.

  In general, when the colorant in the toner is agglomerated, the light reflected by the colorant is absorbed by other colorants, resulting in a decrease in brightness and a dark color. Therefore, when the colorant is dissolved in a solvent or the like, that is, in a state where it is dispersed at a molecular level, the colorant can exhibit its performance as a colorant such as hue, saturation and brightness. When the colorant is a pigment as in the present invention, it is considered that the performance inherent to the colorant can be exhibited as the dispersed particle size is made smaller and closer to the molecular level.

(A) L ^* a ^* b ^* L ^* a ^* b ^* coordinate diagram showing the color space by the color system, (b) L ^* a ^* b ^* a ^* b ^* coordinate diagram showing the color space by the color system is there. 1 is a schematic cross-sectional view illustrating an example of an image forming apparatus using a toner according to the present invention.

  The cyan toner of the present invention is an electrostatic charge image developing toner containing at least a binder resin and a colorant, and the colorant is an axial ligand-containing colorant compound X represented by the following general formula (1): The number average particle size of the dispersed particles of the axial ligand-containing colorant compound X in the toner is 5 nm or more and 50 nm or less.

(In the general formula (1), M ¹ represents a group 14 metal atom. Further, two Qs each independently represents a monovalent substituent, and m and n are each 0 or 1, and at least One is 1. Also, four A's each independently represent an atomic group that forms an aromatic ring which may have a substituent.
Axial ligand containing colorant compound X is a compound having an axial ligand in a direction perpendicular to the phthalocyanine ring from the central metal atom M ^1. Here, having the axial ligand in the vertical direction means that there is no axial ligand on the same plane with respect to the phthalocyanine ring, and in the axial ligand-containing colorant compound X, the axial coordination It is not essential that the child is exactly 90 ° C. in the plane.

In the axial ligand-containing colorant compound X represented by the general formula (1), the central metal atom M ¹ is a Group 14 metal atom. Examples of the central metal atom M ^1, for example Si, Ge, can be exemplified a Sn, in particular, in order to sufficiently chromogenic according to high lightness cyan region can be obtained, Si is preferred.

In the general formula (1), two Q's each independently represent a monovalent substituent, specifically, an alkyl group, an aryl group, an aryloxy group, an alkoxy group, an acyloxy group, or the following general formula (2 ), And more preferably an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, and 1 to 22 carbon atoms. An alkoxy group, an acyloxy group having 2 to 30 carbon atoms, specifically, for example, —O (CH ₂ ) ₃ CH ₃ , —O (CH ₂ ) ₅ CH ₃ , —O (CH ₂ ) ₇ CH ₃ , _{-OC 6 H 6, -OCO-CH} 2 CH 2 CH 3, -OSi (CH 3) 3, -OSi (CH 2 CH 3) 3, -OSi (CH 2 CH 2 CH 3) 3 and the like.

  At least one Q in the general formula (1) is any one of the above-described alkyl group, aryl group, aryloxy group, alkoxy group, acyloxy group, or a compound group represented by the following general formula (2). Preferably, two Q's are both the above-mentioned alkyl group, aryl group, aryloxy group, alkoxy group, acyloxy group, or a compound group represented by the following general formula (2).

In the general formula ^{(2), R 1, R} 2, R 3 are each independently an alkyl group, an aryl group, an aryloxy group or an alkoxy group, preferably an alkyl group having 1 to 22 carbon atoms, 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, more preferably an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, An alkoxy group having 1 to 10 carbon atoms or an aryloxy group having 6 to 10 carbon atoms, more preferably an alkyl group having 2 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, and an alkoxy group having 2 to 8 carbon atoms. Or an aryloxy group having 6 to 8 carbon atoms, particularly preferably an n-propyl group, an iso-propyl group, an n-butyl group, an isobutyl group, or a t-butyl group.

  M and n according to two Qs in the general formula (1) are each 0 or 1, and at least one is 1, that is, the axial ligand-containing colorant compound X has at least one axial coordination. It is preferable to have a child.

  Furthermore, in the general formula (1), four A's each independently represent an atomic group that forms an aromatic ring that may have a substituent. Specific examples of the atomic group include, for example, the following formula (A -1)-what is shown to following formula (A-29) can be illustrated, Preferably it is shown to following formula (A-1).

Examples of the substituent in A include a chlorine atom, a salt halogenated methyl group (—CClX ₂ ) (where X is a halogen atom), a fluoromethyl group (—CH ₂ F), a trifluoromethyl group (—CF ₃ ), An electron withdrawing group such as a nitro group (—NO ₂ ), an alkyl group having 4 to 8 carbon atoms such as a t-butyl group, and an alkoxy group such as —O (CH ₂ ) ₇ CH ₃ .

In the general formula (2), R ¹ , R ² and R ³ each independently represents an alkyl group, an aryl group, an aryloxy group or an alkoxy group, preferably 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, more preferably an alkyl group having 1 to 10 carbon atoms and an aryl having 6 to 10 carbon atoms Group, an alkoxy group having 1 to 10 carbon atoms, or an aryloxy group having 6 to 10 carbon atoms, more preferably an alkyl group having 2 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, and 2 to 8 carbon atoms. And an aryloxy group having 6 to 8 carbon atoms, specifically preferably an n-propyl group, an iso-propyl group, an n-butyl group, an isobutyl group, or a t-butyl group.

  Specific examples of the axial ligand-containing colorant compound X represented by the general formula (1) include compounds represented by the following formulas (X-1) to (X-6).

  The axial ligand-containing colorant compound X of the present invention can be easily synthesized by a known method. For example, it can be referred from the contents described in the following patent specifications. U.S. Pat.Nos. 5,428,152, 4,927,735, 5,021,563, 5,219,706, 5,034,309, 5,284,943, 5,075,203, 5,484,585 No., No. 5039600, No. 5438135, No. 5656875, etc.

[L ^* a ^* b ^* color system]
Next, the “L ^* a ^* b ^* color system” used for the evaluation of hue and saturation in the present invention will be described. The "L ^* a ^* b ^* color system", in the uniform color space CIE (International Lighting Society) is defined, a means usefully employed to represent by digitizing the color, L shown in FIG. 1 ^* a ^* b ^* indicates a color space based on the color system. In the L ^* a ^* b ^* coordinate diagram, the L ^* axis direction represents lightness, the a ^* axis direction represents the hue in the red-green direction, and the b ^* axis direction represents the hue in the yellow-blue direction. Lightness refers to the relative brightness of a color, hue refers to a hue such as red, yellow, green, blue, and purple, and saturation refers to the degree of vividness of the color.

It shows that the color becomes brighter as L ^* increases and becomes darker as L ^* decreases. It shows that the color becomes more vivid as the absolute value of both a ^* and b ^* increases, and the color becomes dull as it approaches 0. This makes it possible to digitize one color using L ^* a ^* b ^* .

In addition to “lightness” and “hue”, there is “saturation C ^* ” as a method for digitizing the degree of vividness, which can be obtained by the calculation formula (1).

Formula (1): Saturation (C ^* ) = [(a ^* ) ² + (b ^* ) ² ] ^1/2
In addition, as shown in FIG. 1B, the “hue angle” is a line segment OP ′ between the origin O and the coordinate point P ′ (a, b), for example, on the a ^* axis−b ^* axis plane, The angle θ formed with the a ^* axis is specifically calculated by the following equation (2).

Formula (2): Hue angle = tan ⁻¹ (b ^* / a ^* )
(In the above formula (2), a ^* and b ^* represent the values of a and b at the coordinate points (a and b), respectively).
Specifically, L ^* , a ^* , and b ^* are spectrophotometers “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth), a D65 light source as a light source, a φ4 mm reflection measurement aperture, and a measurement wavelength range 380 to 730 nm are measured at 10 nm intervals, the viewing angle is 2 °, and the reference alignment is measured under the condition using a dedicated white tile.

Further, since L ^* , a ^* , b ^* and the saturation C ^* calculated therefrom also vary depending on the toner adhesion amount, when evaluating, it is necessary to measure with a constant toner adhesion amount.

[Method for producing cyan toner]
The method for producing the cyan toner of the present invention is not particularly limited. For example, in addition to the pulverization method, dissolution suspension method, suspension polymerization method, emulsion polymerization aggregation method, miniemulsion polymerization aggregation method, phase inversion emulsion aggregation method, etc. The wet method and other known methods can be used, but it is preferable to use an emulsion polymerization aggregation method or a miniemulsion polymerization aggregation method. According to the emulsion polymerization aggregation method and the miniemulsion polymerization aggregation method, the cyan toner particles can be easily reduced in size from the viewpoint of production cost and production stability.

  Here, in the emulsion polymerization aggregation method, a dispersion of fine particles of a binder resin produced by the emulsion polymerization method (hereinafter also referred to as “binder resin fine particles”) is used as a dispersion of colorant particles (hereinafter referred to as “colorant fine particles”). And agglomerated until the toner particle diameter is a desired value, and further, the shape is controlled by fusing the binder resin fine particles to produce toner particles. .

An example of using the emulsion polymerization aggregation method as a method for producing the cyan toner of the present invention is shown below.
(1) Step of preparing a dispersion in which fine particles of colorant are dispersed in an aqueous medium (2) Dispersion in which binder resin fine particles containing an internal additive are dispersed in an aqueous medium as required Step of preparing the liquid (3) The colorant fine particle dispersion and the binder resin fine particle dispersion are mixed, and the colorant and the binder resin fine particles are aggregated, associated, and fused to form cyan toner particles. (4) A step of filtering cyan toner particles from a dispersion (aqueous medium) of cyan toner particles to remove a surfactant and the like (5) A step of drying cyan toner particles (6) A cyan toner particle Step of adding and mixing external additives When producing cyan toner by emulsion polymerization aggregation method, the binder resin fine particles obtained by emulsion polymerization method have a multilayer structure of two or more layers made of binder resins having different compositions Have The binder resin fine particles having such a structure, for example, those having a two-layer structure may be prepared by adjusting the dispersion of resin particles by emulsion polymerization treatment (first stage polymerization) according to a conventional method. A polymerization initiator and a polymerizable monomer are added to the liquid, and this system can be obtained by a technique of polymerization treatment (second stage polymerization).

  In addition, cyan toner particles having a core-shell structure can be obtained by an emulsion polymerization aggregation method. Specifically, cyan toner particles having a core-shell structure are obtained by first binding resin particles for core particles and coloring. The core particles are prepared by agglomerating, associating and fusing the fine particles of the agent, and then the binder resin fine particles for the shell layer are added to the core particle dispersion to bind the shell layer to the surface of the core particles. It can be obtained by agglomerating and fusing resin fine particles to form a shell layer covering the core particle surface.

(Dispersing method of colorant)
Next, a method for dispersing the colorant in the aqueous medium will be described.

  When the toner particles are produced by a wet method, an existing well-known disperser can be used. Specifically, an ultrasonic disperser, a homogenizer, a disper mill, a clear mix, a sand mill, an ultra visco mill, a pearl mill, a glen mill, a dyno mill, an agitator mill, a dynamic mill and the like can be used in the presence of a surfactant. For the dispersion of the silicon phthalocyanine pigment of the present invention, CLEARMIX is preferred.

  In the case of using Claremix W Motion CLM0.8 (manufactured by Mtex Co., Ltd.), a glass medium, zirconia beads, or the like can be used as a dispersion medium in the range of 1% by mass to 20% by mass of a surfactant. As these dispersion media, zirconia beads are preferable, and as the particle diameter of the beads, the smaller the dispersion particle diameter, the more preferable is 0.1 mm to 0.8 mm, and further preferable is 0.3 mm. The amount of beads is preferably 30% to 70% by volume of the internal volume of the dispersion tank.

  It is not preferable that the hue angle changes greatly. Copper phthalocyanine changes the hue angle when the dispersed particle size of the colorant dispersion is reduced, but the axial ligand-containing colorant compound X does not change the hue even when the dispersed particle size of the colorant dispersion is reduced. Absent. This is because copper phthalocyanine has a planar structure without an axial ligand, whereas the axial ligand-containing colorant compound X has an axial ligand and has a three-dimensional structure. ing. Since copper phthalocyanine has a planar structure, aggregation of copper phthalocyanine is likely to occur and its properties are likely to change. As a result, the hue angle changes.

  On the other hand, the compound X hardly aggregates between the compounds X due to the steric hindrance of the axial ligand, and the properties thereof do not change. Therefore, no change occurs in the hue angle.

[Surfactant]
In the colorant fine particle dispersion preparation step and / or the binder resin fine particle polymerization step, a surfactant may be added to the aqueous medium in order to stably disperse the fine particles in the aqueous medium. As the surfactant, conventionally known various anionic surfactants, cationic surfactants, nonionic surfactants and the like can be used.

  Examples of the anionic surfactant include higher fatty acid salts such as sodium oleate; alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfate salts such as sodium lauryl sulfate; polyethoxyethylene lauryl ether sodium sulfate Polyoxyethylene alkyl ether sulfate salts of polyoxyethylene alkylaryl ether sulfate salts such as sodium polyoxyethylene nonylphenyl ether sulfate; sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate, etc. Examples thereof include alkyl sulfosuccinic acid ester salts and derivatives thereof.

  Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, and imidazolinium salts.

  Furthermore, examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonylphenyl ether, and sorbitan mono Sorbitan higher fatty acid esters such as laurate, sorbitan monostearate, sorbitan trioleate; polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate; polyoxyethylene monolaurate, polyoxyethylene monostearate Polyoxyethylene higher fatty acid esters such as glycerin higher fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride Ethers; polyoxyethylene - polyoxypropylene - and the like block copolymer.

  The surfactant used for dispersing the axial ligand-containing colorant compound X of the present invention is preferably sodium n-dodecyl sulfate.

(Measurement of dispersed particle size in colorant dispersion)
The dispersion particle diameter of the colorant fine particles in the aqueous medium is the number average particle diameter, that is, the median diameter (D ₅₀ ) in the number distribution. This median diameter was measured using “MICROTRAC UPA 150” (manufactured by HONEYWELL). Value.

(Measurement condition)
(1) Sample refractive index: 1.59
(2) Sample sample specific gravity: 1.05 (in terms of spherical particles)
(3) Solvent refractive index: 1.33
(4) Solvent viscosity: 0.797 at 30 ° C
1.002 at 20 ° C
Ion exchange water was put into the measurement cell and zero point adjustment was performed.

  Here, the dispersed particle diameter of the colorant in the aqueous medium is preferably 5 nm or more and 30 nm or less. If it is less than 5 nm, a great deal of energy is required for dispersion, and it is difficult to disperse substantially. If it exceeds 30 nm, sufficient saturation cannot be obtained when it is converted into a toner.

[Measurement method of colorant dispersed particle size in toner particles]
The number average particle diameter of the colorant dispersed in the cyan toner particles of the present invention is a value measured by the following method. That is, a photographic image obtained by magnifying a cyan toner particle cross-section with a transmission electron microscope “JEM-2000FX” (manufactured by JEOL Ltd.) by 50,000 times is captured by a scanner, and an image processing analyzer LUZEX AP (manufactured by Nireco) ), The ferret direction of the fine colorant particles in the colored cyan toner particles dispersed in the toner binder resin is measured for 10 cyan toners, and the arithmetic average value is calculated. This is the number average particle diameter of the colorant dispersed in the toner. However, the number of colorant-dispersed particles is 100 or more, and when the number is less than 100, the number of toners to be observed is increased. The colorant-dispersed particles refer to particles in a shape that exists independently in the binder resin, not primary particles.

  Here, the dispersed particle diameter of the cyan colorant in the toner particles is preferably 5 nm or more and 50 nm or less. If the thickness is less than 5 nm, a large amount of energy is required for dispersion, and the dispersion cannot substantially be performed. If the thickness exceeds 50 nm, sufficient saturation cannot be obtained.

[Production method of toner by pulverization method]
An example of using the pulverization method as a method for producing the cyan toner of the present invention is shown below.
(1) Step of mixing binder resin, colorant and, if necessary, internal additive with Henschel mixer etc. (2) Step of kneading the obtained mixture while heating with an extrusion kneader etc. (3) obtained After coarsely pulverizing the kneaded product with a hammer mill or the like, and further pulverizing with a turbo mill pulverizer or the like (4) The obtained pulverized product is finely classified using, for example, an air classifier utilizing the Coanda effect. Step of forming cyan toner particles (5) Step of adding and mixing external additives to cyan toner particles In the kneading step of (2) above, it is preferable that the kneading temperature is high and the kneading time is long.

  When a toner is prepared by a pulverization method, a colorant, a binder resin, and other internal additives such as a release agent and a charge control agent are premixed as necessary, and then kneaded in a kneader. scatter. At this time, in addition to the screw configuration, length, number of revolutions, etc., the kneading temperature, kneading time, etc. are adjusted to disperse to an optimum particle size. As the kneader, a twin screw extrusion kneader is most preferably used.

[Binder resin]
As the binder resin contained in the cyan toner of the present invention, for example, when the cyan toner is produced by a pulverization method, a dissolution suspension method, an emulsion aggregation method, or the like, a styrene resin, a (meth) acrylic resin, Styrene- (meth) acrylic copolymer resins, vinyl resins such as olefin resins, polyester resins, polyamide resins, carbonate resins, polyethers, polyvinyl acetate resins, polysulfones, epoxy resins, polyurethane resins, urea Various known resins such as resins can be used. These can be used alone or in combination of two or more.

  For example, when a cyan toner is produced by a suspension polymerization method, an emulsion polymerization aggregation method, a miniemulsion polymerization aggregation method, or the like, as a polymerizable monomer for obtaining a binder resin, for example, styrene, o-methylstyrene , M-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butyl Styrene or styrene derivatives such as styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene; methyl methacrylate, ethyl methacrylate , N-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, Methacrylic acid ester derivatives such as t-butyl tacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate; 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. Acrylic ester derivatives; Olefins such as ethylene, propylene and isobutylene; Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride and vinylidene fluoride Vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl carbazole N-vinyl compounds such as N-vinylindole and N-vinylpyrrolidone; Vinyl compounds such as vinylnaphthalene and vinylpyridine; Acrylic acid such as acrylonitrile, methacrylonitrile and acrylamide, or vinyl-based compounds such as methacrylic acid derivatives A polymer can be mentioned. These vinyl monomers can be used alone or in combination of two or more.

  Further, as the polymerizable monomer for obtaining the binder resin, it is preferable to use a combination of the polymerizable monomer having an ionic dissociation group. The polymerizable monomer having an ionic dissociation group has, for example, a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a constituent group, and specifically includes acrylic acid, methacrylic acid, maleic acid. Acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl methacrylate And 3-chloro-2-acid phosphooxypropyl methacrylate.

  Furthermore, as a polymerizable monomer, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl A binder resin having a crosslinked structure can also be obtained using a polyfunctional vinyl such as glycol diacrylate.

  The cyan toner of the present invention can contain an internal additive and an external additive such as a charge control agent and a release agent, if necessary.

[Charge control agent]
The charge control agent is not particularly limited as long as it can give positive or negative charge by frictional charging, and various known positive charge control agents and negative charge control agents can be used.

  The content of the charge control agent is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

〔Release agent〕
Various known waxes can be used as the release agent. Examples of the wax include polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrystalline wax, long chain hydrocarbon waxes such as paraffin wax and sazol wax, and dialkyls such as distearyl ketone. Ketone wax, carnauba wax, montan wax, behenate behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanedioldi Ester waxes such as stearate, tristearyl trimellitic acid, distearyl maleate, ethylenediamine behenylamide, tristearyl trimellitic acid Such as amide-based waxes such as bromide and the like.

  It is preferable that content of a mold release agent is 0.1-30 mass parts with respect to 100 mass parts of binder resin, More preferably, it is 1-10 mass parts.

(External additive)
As the cyan toner of the present invention, the cyan toner particles can be used as they are. However, in order to improve the fluidity, chargeability, cleaning properties, etc. of the cyan toner particles, a fluidizing agent and a cleaning aid are used. An external additive such as an agent can also be added and used.

  Examples of the external additive include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, strontium titanate, and zinc titanate. Inorganic fine particles such as inorganic titanic acid compound fine particles.

  These inorganic fine particles are preferably those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, or the like from the viewpoint of heat-resistant storage stability and environmental stability.

  The addition amount of the external additive is 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the cyan toner. Various external additives may be used in combination.

[Cyan toner particle diameter]
The particle size of the cyan toner particles constituting the cyan toner of the present invention is preferably 4 to 10 μm, more preferably 5 to 9 μm in terms of volume-based median diameter.

  When the volume-based median diameter is in the above range, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.

  The volume-based median diameter of cyan toner particles is measured and calculated using a measuring device in which a computer system for data processing (manufactured by Beckman Coulter) is connected to “Coulter Multisizer 3” (manufactured by Beckman Coulter). The

  Specifically, 0.02 g of cyan toner is added to 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 cyan toner particles). After being added and blended in, ultrasonic dispersion treatment was performed for 1 minute to prepare a cyan toner particle dispersion, and this cyan toner particle dispersion was prepared as “ISOTON II” (Beckman Coulter, Inc.) in the sample stand. Pipette into the beaker containing) until the display concentration of the measuring device is 5-10%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measurement apparatus, the measurement particle count is 25000, the aperture diameter is 50 μm, the frequency value is calculated by dividing the measurement range of 1 to 30 μm into 256, and the volume integrated fraction is 50 % Is the volume-based median diameter.

[Softening point temperature of cyan toner]
The cyan toner of the present invention preferably has a softening point temperature (Tsp) of 70 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower. The colorant contained in the cyan toner of the present invention has a stable property that the spectrum does not change even under the influence of heat, but the softening point temperature (Tsp) is within the above range. The influence of heat applied to the cyan toner during fixing can be further reduced. Therefore, since image formation can be performed without imposing a burden on the colorant, it is expected that a wider and more stable color reproducibility is expressed.

  In addition, because the softening point temperature (Tsp) of cyan toner is in the above range, it is possible to fix the toner image at a temperature lower than that of the prior art, and to realize environmentally friendly image formation with reduced power consumption. can do.

The softening point temperature (Tsp) of the cyan toner can be controlled by, for example, the following methods alone or in combination. That is,
(1) The type and composition ratio of the monomer that should form the binder resin are adjusted.
(2) The molecular weight of the binder resin is adjusted by the type and amount of chain transfer agent.
(3) Adjust the type and amount of release agent.

As a method for measuring the softening point temperature (Tsp) of the cyan toner, for example, “Flow Tester CFT-500 (manufactured by Shimadzu Corporation)” is used to form a cylindrical shape having a height of 10 mm and heated at a heating rate of 6 ° C./min. While applying a pressure of 1.96 × 10 ⁶ Pa from the plunger while pushing from a nozzle having a diameter of 1 mm and a length of 1 mm, a curve between the plunger drop amount and temperature of the flow tester (softening flow curve) And the first outflow temperature is the melting start temperature, and the temperature for the drop of 5 mm is the softening point temperature.

(Developer)
The cyan toner of the present invention can be used as a non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.

  When used as a two-component developer, the carrier is made of a conventionally known material such as a ferromagnetic metal such as iron, an alloy such as ferromagnetic metal and aluminum and lead, and a compound of ferromagnetic metal such as ferrite and magnetite. Magnetic 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 magnetic fine powder is dispersed in a binder resin, and the like can also be used. The coating resin constituting the coat carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene-acrylic resins, silicone resins, ester resins, and fluorine resins. Moreover, it does not specifically limit as resin which comprises a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic-type resin, a polyester resin, a fluororesin, a phenol resin etc. can be used.

  The volume-based median diameter of the carrier is preferably 20 to 100 μm, more preferably 20 to 60 μm.

  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.

(Image forming method)
The cyan toner of the present invention can be suitably used in a general electrophotographic image forming method together with, for example, three color toners of yellow toner and magenta toner. Further, black toner may be used together with the above three color toners as necessary.

  In addition, as the colorant contained in each color toner other than the cyan toner used in the image forming method using the cyan toner of the present invention, a conventionally known colorant can be used and contained in each color toner. The binder resin, the internal additive, and the like can have the same configuration as that used in the cyan toner of the present invention.

  The yellow toner preferably contains a colorant having a hue angle of 70 to 100 °.

  Specifically, examples of the colorant contained in the yellow toner include C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Pigment yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, and the like. These can be used alone or in combination of two or more. Among these, C.I. I. Pigment Yellow 74 is preferable.

  The content of the colorant contained in the yellow toner is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the binder resin.

  Further, the magenta toner preferably contains a colorant having a hue angle of −40 to 40 °.

  Specifically, examples of the colorant contained in the magenta toner include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, and the like. These can be used alone or in combination of two or more. Among these, C.I. I. Pigment Red 122 is preferable.

  The content of the colorant contained in the magenta toner is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the binder resin.

  The preferred hue angle of the cyan toner is generally in the range of 190 ° to 300 °, but the most preferred hue angle from the above viewpoint is 200 ° to 230 °, and the axial ligand-containing colorant compound X of the present invention is It has a hue angle of 210 ° to 220 °, and this hue angle can be expected to exhibit the most preferable hue angle when it is used as a toner.

  Examples of the colorant contained in the black toner include carbon black, magnetic material, and titanium black. Examples of carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. Examples of magnetic materials include ferromagnetic metals such as iron, nickel, and cobalt, alloys containing these ferromagnetic metals, compounds of ferromagnetic metals such as ferrite and magnetite, and ferromagnetic materials that do not contain ferromagnetic metals but are heat treated. The alloy shown etc. are mentioned. Examples of alloys that exhibit ferromagnetism by heat treatment include Heusler alloys such as manganese-copper-aluminum and manganese-copper-tin, and chromium dioxide.

  The content of the colorant contained in the black toner is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the binder resin.

The hue angles of the cyan toner, yellow toner, and magenta toner of the present invention are present in the order of magenta toner, yellow toner, and cyan toner in the counterclockwise direction in the L ^* a ^* b ^* color system. Just do it.

Specific examples of a method for forming an image using the cyan toner of the present invention and the above-described three color toners include the following methods (1) and (2).
(1) A toner image forming process in which a toner image formed by developing an electrostatic latent image formed on an electrostatic latent image carrier with a toner is directly transferred to a transfer material. Yellow toner, magenta toner, cyan By using four color toners, toner and black toner, a transfer material carrying a toner image is obtained, and an image is formed by fixing these toner images on the transfer material, so-called direct transfer type image formation. Method.
(2) a toner image forming step of transferring a toner image formed by developing the electrostatic latent image formed on the electrostatic latent image carrier to the intermediate transfer member, at least yellow toner, magenta toner, By using four colors of toner, cyan toner and black toner, an intermediate transfer member carrying a toner image is obtained, and these toner images are transferred onto a transfer material and fixed to form an image. Intermediate transfer image forming method.

  Among such image forming methods, an intermediate transfer type image forming method using yellow toner, magenta toner, cyan toner, and black toner will be specifically described below.

<Image forming apparatus>
An image forming apparatus according to the present invention will be described.

An image forming apparatus that realizes the effects of the present invention is as follows.
(1) An electrophotographic photosensitive member having at least the surface layer of the present invention,
(2) Charging means for charging the surface of the electrophotographic photosensitive member described above,
(3) An exposure unit that performs image exposure on the surface of the electrophotographic photosensitive member charged by the charging unit to form a latent image; a developing unit that visualizes the latent image formed by the exposure unit and forms a toner image;
(4) The image forming apparatus includes a transfer unit that transfers the toner image formed on the surface of the electrophotographic photosensitive member by the developing unit onto a transfer medium such as paper or a transfer belt.

  Note that a non-contact charging device is preferably used as the charging means for charging the electrophotographic photosensitive member. Examples of the non-contact charging device include a corona charging device, a corotron charging device, and a scorotron charging device.

  FIG. 2 is a cross-sectional configuration diagram of a color image forming apparatus showing one embodiment of the present invention.

  This color image forming apparatus is called a tandem type color image forming apparatus, and includes four sets of image forming units (image forming units) 10Y, 10M, 10C, and 10Bk, an endless belt-shaped intermediate transfer body unit 7, and a feeding unit. It comprises a paper conveying means 21 and a fixing means 24. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  The image forming unit 10Y that forms a yellow image includes a charging unit (charging step) 2Y, an exposure unit (exposure step) 3Y, and a developing unit disposed around a drum-shaped photoconductor 1Y as a first image carrier. A unit (developing step) 4Y, a primary transfer roller 5Y as a primary transfer unit (primary transfer step), and a cleaning unit 6Y. An image forming unit 10M that forms a magenta image includes a drum-shaped photosensitive member 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, It has a cleaning means 6M. An image forming unit 10C for forming a cyan image includes a drum-shaped photoreceptor 1C as a first image carrier, a charging unit 2C, an exposure unit 3C, a developing unit 4C, and a primary transfer roller 5C as a primary transfer unit. It has cleaning means 6C. The image forming unit 10Bk that forms a black image includes a drum-shaped photoreceptor 1Bk as a first image carrier, a charging unit 2Bk, an exposure unit 3Bk, a developing unit 4Bk, a primary transfer roller 5Bk as a primary transfer unit, and a cleaning unit. 6Bk.

  The four sets of image forming units 10Y, 10M, 10C, and 10Bk include charging means 2Y, 2M, 2C, and 2Bk that rotate around the photosensitive drums 1Y, 1M, 1C, and 1Bk, and image exposure means 3Y, 3M, 3C and 3Bk, rotating developing means 4Y, 4M, 4C and 4Bk, and cleaning means 6Y, 6M, 6C and 6Bk for cleaning the photosensitive drums 1Y, 1M, 1C and 1Bk.

  The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration except that the colors of toner images formed on the photoreceptors 1Y, 1M, 1C, and 1Bk are different, and the image forming unit 10Y is taken as an example in detail. explain.

  The image forming unit 10Y has a charging unit 2Y (hereinafter simply referred to as a charging unit 2Y or a charger 2Y), an exposure unit 3Y, a developing unit 4Y, and a cleaning unit 6Y (around a photosensitive drum 1Y as an image forming body). Hereinafter, the cleaning unit 6Y or the cleaning blade 6Y) is simply disposed, and a yellow (Y) toner image is formed on the photosensitive drum 1Y. In the present embodiment, in the image forming unit 10Y, at least the photosensitive drum 1Y, the charging unit 2Y, the developing unit 4Y, and the cleaning unit 6Y are provided so as to be integrated.

  The charging unit 2Y is a unit that applies a uniform potential to the photosensitive drum 1Y. In the present embodiment, a corona discharge type charger 2Y is used for the photosensitive drum 1Y.

  The image exposure means 3Y performs exposure based on the image signal (yellow) on the photosensitive drum 1Y given a uniform potential by the charger 2Y, and forms an electrostatic latent image corresponding to the yellow image. As the exposure means 3Y, the exposure means 3Y includes an LED in which light emitting elements are arranged in an array in the axial direction of the photosensitive drum 1Y and an imaging element (trade name; Selfoc lens), or A laser optical system or the like is used.

  The image forming apparatus of the present invention is configured by integrally combining the above-described photosensitive member and components such as a developing device and a cleaning device as a process cartridge (image forming unit), and this image forming unit is connected to the apparatus main body. It may be configured to be detachable. In addition, at least one of a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with a photosensitive member to form a process cartridge (image forming unit), which is detachable from the apparatus main body. A single image forming unit may be detachable using guide means such as a rail of the apparatus main body.

  The endless belt-like intermediate transfer body unit 7 includes an endless belt-like intermediate transfer body 70 as a second image carrier having a semiconductive endless belt shape that is wound around a plurality of rollers and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10Bk is sequentially transferred onto a rotating endless belt-shaped intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means. Thus, a synthesized color image is formed. A transfer material P as a transfer material (a support for carrying a fixed final image: for example, plain paper, a transparent sheet, etc.) housed in the paper feed cassette 20 is fed by a paper feed means 21 and a plurality of intermediates. After passing through rollers 22A, 22B, 22C, 22D and registration roller 23, they are conveyed to a secondary transfer roller 5b as a secondary transfer means, and are secondarily transferred onto a transfer material P to transfer a color image all at once. The transfer material P onto which the color image has been transferred is subjected to fixing processing by the fixing unit 24, is sandwiched between paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus. Here, a transfer support for a toner image formed on a photosensitive member such as an intermediate transfer member or a transfer material is collectively referred to as a transfer medium.

  On the other hand, after the color image is transferred to the transfer material P by the secondary transfer roller 5b as the secondary transfer means, the residual toner is removed by the cleaning means 6b from the endless belt-shaped intermediate transfer body 70 in which the transfer material P is separated by curvature. The

  During the image forming process, the primary transfer roller 5Bk is always in contact with the photoreceptor 1Bk. The other primary transfer rollers 5Y, 5M, and 5C are in contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roller 5b contacts the endless belt-shaped intermediate transfer body 70 only when the transfer material P passes through the secondary transfer roller 5b.

  Further, the housing 8 can be pulled out from the apparatus main body A through the support rails 82L and 82R.

  The housing 8 includes image forming units 10Y, 10M, 10C, and 10Bk and an endless belt-shaped intermediate transfer body unit 7.

  The image forming units 10Y, 10M, 10C, and 10Bk are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is disposed on the left side of the photoreceptors 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt-shaped intermediate transfer body unit 7 includes an endless belt-shaped intermediate transfer body 70 that can be rotated by winding rollers 71, 72, 73, 74, primary transfer rollers 5Y, 5M, 5C, 5Bk, and cleaning means 6b. Consists of.

  As described above, the embodiments of the image forming method using the cyan toner of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.

[Transfer material]
As a transfer material used in the image forming method as described above, for example, plain paper from thin paper to thick paper, high-quality paper, coated printing paper such as art paper or coated paper, commercially available Japanese paper or postcard paper, Various examples such as a plastic film and cloth for OHP can be mentioned, but the invention is not limited thereto.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Preparation of Colorant Fine Particle Dispersion [1]]
11.5 parts by mass of sodium n-dodecyl sulfate was added to 160 parts by mass of ion-exchanged water, and dissolved and stirred to prepare an aqueous surfactant solution. In this surfactant aqueous solution, 21.8 parts by mass of the compound of the formula (X-1) is gradually added, and dispersion treatment is performed using “Clearmix W Motion CLM-0.8” (manufactured by M Technique). A colorant fine particle dispersion [1] was prepared.

[Preparation of Colorant Fine Particle Dispersions [2] to [12]]
In the preparation of the colorant fine particle dispersion [1], the colorant fine particle dispersions [2] to [12] were prepared with the colorant, the surfactant amount, the dispersion conditions, etc. as shown in Table 1. Table 1 shows the dispersed particle diameters of the colorant fine particles in each colorant fine particle dispersion.

[Production Example of “Cyan Toner 1” of Example 1]
(1) Preparation Example of Resin Particle [1] (a) First Stage Polymerization: Preparation of Resin Particle [A1] Polyoxyethylene lauryl sulfate in a reaction vessel equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introducing device 4 parts by mass of ether was added together with 3040 parts by mass of ion-exchanged water to prepare an aqueous surfactant solution.

  In this surfactant aqueous solution, a polymerization initiator solution prepared by dissolving 10 parts by mass of potassium persulfate as a polymerization initiator in 400 parts by mass of ion-exchanged water was added, and this system was heated to 75 ° C. A polymerizable monomer mixture composed of the compound was dropped into the reaction vessel 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 dropping the polymerizable monomer mixture, the system is heated and stirred at 75 ° C. for 2 hours. As a result, first-stage polymerization was performed to prepare resin particles [A1].
(B) Second-stage polymerization: Preparation of resin particles [A2] A polymerizable monomer mixed solution composed of the following compounds was charged into a flask equipped with a stirrer, and paraffin wax “HNP-57” ( 93.8 parts by mass) (manufactured by Nippon Seiwa Co., Ltd.) was added and dissolved by heating to 90 ° C.

Styrene 101.1 parts by weight n-butyl acrylate 62.2 parts by weight Methacrylic acid 12.3 parts by weight n-octyl mercaptan 1.75 parts by weight 3 parts by weight of polyoxyethylene lauryl sulfate ether is dissolved in 1560 parts by weight of ion-exchanged water. An aqueous surfactant solution was prepared and heated to 98 ° C. After adding 32.8 parts by mass (in terms of solid content) of resin particles [A1] to this surfactant aqueous solution, and further adding a polymerizable monomer mixture containing paraffin wax, mechanical disperser “Claire” Mix ”(manufactured by MTechnic Co., Ltd.) was used for 8 hours to mix and disperse to prepare an emulsified particle dispersion having emulsified particles having a dispersed particle size of 340 nm.

Next, a polymerization initiator solution in which 6 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added to the emulsified particle dispersion, and this system was heated and stirred at 98 ° C. for 12 hours to obtain the second. Step polymerization was performed to prepare resin particles [A2].
(C) Third stage polymerization: production of resin particles [1] A polymerization initiator solution in which 5.45 parts by mass of potassium persulfate was dissolved in 220 parts by mass of ion-exchanged water was added to resin particles [A2]. Under a temperature condition of 80 ° C., a polymerizable monomer mixed solution composed of the following compounds was added dropwise 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 dropwise addition of this polymerizable monomer mixture, the third stage polymerization is carried out by heating and stirring for 2 hours. And cooled to 28 ° C. to produce resin particles [1].
(2) Production process of resin particles for shell [1] The polymerization reaction and the treatment after the reaction were the same except that the monomer mixture used in the first stage polymerization in (a) was changed to the following. The shell resin particles [1] were produced.

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 (3) Preparation example of cyan toner particles [1] (a) Preparation of core part [1] Resin particles [ 1] 430 parts by mass (in terms of solid content)
900 parts by mass of ion-exchanged water Colorant fine particle dispersion [1] 30 parts by mass (in terms of solid content) was charged into a reaction vessel and stirred. After adjusting the temperature in the reaction vessel to 30 ° C., a 5 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 8-11.

  Subsequently, an aqueous solution in which 50 parts by mass of magnesium chloride hexahydrate was dissolved in 50 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, heating was started, and the system was heated to 80 ° C. over 60 minutes for association.

  In this state, the particle size of the associated particles is measured using “Multisizer 3” (manufactured by Coulter), and when the volume-based median diameter of the associated particles reaches 6.0 μm, 40.2 parts by mass of sodium chloride is ion-exchanged. The association was stopped by adding an aqueous solution dissolved in 1000 parts by mass of water.

  After the association was stopped, the core temperature [1] was produced by continuing the fusion by heating and stirring for 1 hour at a liquid temperature of 70 ° C. as an aging treatment.

When the average circularity of the core [1] was measured by “FPIA2100” (manufactured by Sysmec), it was 0.912.
(B) Formation of Shell: Preparation of Cyan Toner Particles [1] Next, the above liquid was brought to 65 ° C. and 70 parts by mass (converted to solid content) of resin particles for shell [1] were added. An aqueous solution in which 50 parts by mass of hydrate was dissolved in 50 parts by mass of ion-exchanged water was added over 10 minutes, and then the temperature was raised to 70 ° C. and stirring was performed for 1 hour. In this manner, the shell resin particles [1] were fused to the surface of the core [1], and then aged at 75 ° C. for 20 minutes to form a shell.

Thereafter, an aqueous solution in which 40.2 parts by mass of sodium chloride was dissolved in 1000 parts by mass of ion-exchanged water was added to stop shell formation. Further, the particles produced by cooling to 30 ° C. at a rate of 8 ° C./min are filtered, washed repeatedly with ion exchange water at 45 ° C., and then dried with hot air at 40 ° C. Cyan toner particles [1] having
(4) External additive addition example: Preparation of cyan toner 1 The following external additive was added to cyan toner particles [1] prepared as described above, and "Henschel mixer" (manufactured by Mitsui Miike Mining Co., Ltd.) was added. Then, an external addition process was performed to prepare “Cyan Toner 1”.

Silica treated with hexamethylsilazane (average primary particle size 12 nm)
0.6 part by mass n-octylsilane-treated titanium dioxide (average primary particle size 24 nm)
0.8 parts by mass The external addition treatment by the Henschel mixer was performed under the conditions of a peripheral speed of the stirring blade of 35 m / second, a treatment temperature of 35 ° C., and a treatment time of 15 minutes. The produced “Cyan toner 1” had a volume-based median diameter of 6.5 μm and a softening point of 107 ° C.

[Production of “Cyan Toners 2 to 8” in Examples 2 to 8 and “Cyan Toners 10 to 13” in Comparative Examples 1 to 4]
In the production example of “Cyan Toner 1” in Example 1, the same procedure was followed except that the colorant dispersion liquid [1] was changed to [12] instead of the colorant fine particle dispersion liquid [1]. 2 to 8 “Cyan toners 2 to 8” and Comparative Examples 1 to 4 “Cyan toners 10 to 13” were produced. The “cyan toner 9” of Example 9 was prepared by the following pulverization method.

[Example of Preparation of “Cyan Toner 9” of Example 9: Example of Preparation of Toner by Grinding Method]
(1) Mixing step The following materials were mixed with a “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.) with the peripheral speed of the stirring blade set to 25 m / sec over 5 minutes to obtain a mixture.

Polyester resin (Bisphenol A-ethylene oxide adduct, terephthalic acid, trimellitic acid condensate: weight average molecular weight 20,000) 100 parts by weight Colorant (silicon phthalocyanine) 6 parts by weight Release agent (pentaerythritol tetrastearate) 6 parts by mass Charge control agent (boron dibenzylate) 1 part by mass (2) Kneading step The obtained mixture was kneaded while being heated to 110 ° C. by a twin-screw extrusion kneader to obtain a kneaded product, and then the kneaded product was cooled. did.
(3) Grinding step The obtained kneaded material was coarsely pulverized with a “hammer mill” (manufactured by Hosokawa Micron), and then finely pulverized with a “turbo mill T-400 type” (manufactured by Turbo Kogyo).

The dispersed particle diameter of the colorant in this toner was 17.5 nm in terms of number average particle diameter.
(4) Classifying Step Cyan toner particles [9] having a volume-based median diameter of 6.5 μm were obtained by classifying the obtained fine powder with an air classifier.
(5) External additive addition process The following external additives are added to the cyan toner particles [9] and subjected to external addition processing by “Henschel mixer” (manufactured by Mitsui Miike Mining Co., Ltd.) to produce “Cyan toner 9”. did.

Silica fine particles treated with hexamethylsilazane 0.6 part by mass Titanium dioxide fine particles treated with n-octylsilane 0.8 part by mass External addition with a Henschel mixer was performed at a peripheral speed of a stirring blade of 35 m / second and a treatment temperature of 35 ° C. , Under conditions of a processing time of 15 minutes.

[Development of developer]
Each of the cyan toners 1 to 13 prepared as described above and a ferrite carrier having a volume average particle diameter of 50 μm coated with methyl methacrylate and cyclohexyl methacrylate resin are mixed in a V type so that the concentration of each toner is 6% by mass. A cyan developer was prepared by mixing with a machine.

  A developer “bizhub PRO C6500” (manufactured by Konica Minolta Business Technologies) corresponding to the image forming apparatus shown in FIG. 2 was filled with the developer prepared as described above, and the following evaluation was performed. The results are shown in Table 2.

[Evaluation]
A cyan solid image with a toner adhesion amount of 4 g / m ² was formed on “POD gloss coated paper (128 g / m ² )” (manufactured by Oji Paper Co., Ltd.) using only cyan toner, and L ^* , a ^* and b ^* were measured, respectively. did.

Table 2 shows the saturation C ^* shown by the following formula (1) and the hue angle value shown by the following formula (2).

Formula (1): Saturation (C ^* ) = [(a ^* ) ² + (b ^* ) ² ] ^1/2
Note that L ^* , a ^* , and b ^* are spectrophotometers “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth), a D65 light source as a light source, a φ4 mm reflection measurement aperture, and a measurement wavelength range of 380 to 730 nm. Is measured at the intervals of 10 nm, the viewing angle is 2 °, and a standard white tile is used for alignment.

Formula (2): Hue angle = tan ⁻¹ (b ^* / a ^* )
A saturation level of 61 or higher was accepted. Further, if the deviation of the hue angle due to the dispersed particle diameter in the toner is within 10 °, there is no problem even when producing a secondary color or the like, and the difference cannot be confirmed visually.

  As is clear from the above results, although the hue angle changes when copper phthalocyanine decreases the dispersed particle size of the colorant dispersion, the axial ligand-containing colorant compound X is dispersed particle size of the colorant dispersion. The hue does not change even if the value is reduced.

  It can be seen that the cyan toner of the present invention has a hue angle within a preferable range and extremely excellent saturation compared to the comparative cyan toner.

L ^* Lightness a ^* Hue in red-green direction b ^* Hue in yellow-blue direction 1Y, 1M, 1C, 1Bk Photosensitive drum 2Y, 2M, 2C, 2Bk Charging unit 3Y, 3M, 3C, 3Bk Image exposure unit 4Y, 4M, 4C, 4Bk Developing means 6Y, 6M, 6C, 6Bk Cleaning means 10Y, 10M, 10C, 10Bk Image forming unit

Claims (6)

A cyan toner for developing an electrostatic charge image containing cyan toner particles containing at least a binder resin and a cyan colorant,
The cyan colorant contains an axial ligand-containing colorant compound X represented by the following general formula (1), and the axial ligand-containing colorant compound X in the cyan toner for electrostatic image development is A cyan toner for developing electrostatic images, wherein the number average particle diameter of dispersed particles is from 5 nm to 50 nm.

(In the general formula (1), M ¹ represents a group 14 metal atom. Further, two Qs each independently represents a monovalent substituent, and m and n are each 0 or 1, and at least One is 1. Also, four A's each independently represent an atomic group that forms an aromatic ring which may have a substituent. In the axial ligand-containing colorant compound X represented by the general formula (1), two Qs are each independently an alkyl group, an aryl group, an aryloxy group, an alkoxy group, an acyloxy group, or the following general formula ( The cyan toner for developing electrostatic images according to claim 1, wherein the cyan toner is a compound group represented by 2).

(In the general formula (2), R ¹ , R ² and R ³ each independently represents an alkyl group, an aryl group, an aryloxy group or an alkoxy group.) 3. The cyan toner for developing an electrostatic charge image according to claim 1, wherein in the axial ligand-containing colorant compound X, M ¹ is any one element of Si, Ge, and Sn. 4. The electrostatic charge image according to claim 1, wherein in the axial ligand-containing colorant compound X represented by the general formula (1), M ¹ is Si. 5. Cyan toner for development. A method for producing a cyan toner for developing electrostatic images according to any one of claims 1 to 4,
The production method comprises dispersing at least the axial ligand-containing colorant compound X in an aqueous medium in the presence of a surfactant;
Producing a dispersion of resin fine particles;
A cyan toner for developing an electrostatic charge image, comprising: a step of aggregating and assembling an aqueous dispersion of the axial ligand-containing colorant compound X and a dispersion of the resin fine particles to produce toner base particles Production method. When the axial ligand-containing colorant compound X is dispersed in an aqueous medium, the median diameter (D ₅₀ ) in the number distribution of the dispersed particle diameter of the axial ligand-containing colorant compound X is 5 nm or more and 30 nm or less. The method for producing a cyan toner for developing an electrostatic image according to claim 5.

Images