JP2012225968A - Cyan toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cyan toner for electrostatic charge image development having a suitable hue angle as a cyan color and high chroma saturation and being capable of giving high chroma saturation in a wide luminosity area from a low luminosity area to a high luminosity area.SOLUTION: A cyan toner for electrostatic charge image development contains a colorant comprising at least a binder resin and a zinc phthalocyanine compound, where the toner for electrostatic charge image development is characterized in that, in X-ray diffraction spectrum of the toner for electrostatic charge image development, C value calculated by a formula (1) from a diffraction peak at Bragg angle 2θ to characteristic X-ray of CuKα is 80 or more and 150 or less. The formula (1) is C=(A×100)/B (in which, A represents a peak absolute intensity at Bragg angle 2θ=7.0±0.1° and B represents a peak absolute intensity at Bragg angle 2θ=9.3±0.1°).

Description

  The present invention relates to an electrostatic image developing cyan toner, and more particularly to an electrostatic image developing cyan toner used in an electrophotographic image forming apparatus.

  In an electrophotographic image forming method using an electrostatic charge image developing toner (hereinafter, also simply referred to as “toner”), in recent years, in addition to a conventional monochrome image, an opportunity to form a full-color image is increasing. . The electrophotographic full-color image forming method is widely used in the field of light printing because it does not require a printing plate and can produce the required number of printed materials on demand (preparing the required number of copies when necessary).

  The IT revolution that began in the 1990s has led to a marked digitization of the environment surrounding the printing site. With this digitization, the “RGB” conversion of the input data is being standardized, and the data handled is more colored. It has shifted to a wide reproduction area.

  However, the full-color image forming method based on the electrophotographic method expresses color by a subtractive color method using reflected light, and therefore has a much narrower color reproduction range than a television or computer display that expresses color by an additive color method. 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.

  In full-color image formation by electrophotography, a color image is basically formed by three color toners of yellow toner, magenta toner, and cyan toner, but color toner that can form a color image with a wider color reproduction area than before. The demand is growing. Accordingly, as a colorant used in these color toners, a colorant having a higher level of color characteristics such as hue, saturation and brightness is required. Furthermore, in electrophotographic image formation often used for office use, it is required to have high image storage stability. Therefore, a colorant that does not fade by light or heat is required.

  In general, copper phthalocyanine pigments are used as colorants for cyan toners, but these copper phthalocyanine pigments are excellent for color development in low-lightness cyan regions, but high-lightness cyan regions. The color of was not enough.

  Various techniques have been disclosed for the purpose of improving the color developability of cyan in the high brightness region. For example, a cyan colorant containing a phthalocyanine compound having a substituent on the central metal is disclosed (see, for example, Patent Document 1).

  In addition, a technique in which two or more compounds are used in combination in order to improve the color reproducibility of the low brightness and high brightness cyan regions is disclosed. For example, a cyan pigment obtained by wet pulverizing copper phthalocyanine and nickel phthalocyanine in the presence of an inorganic salt and an organic solvent has been disclosed, and this has a smaller particle size and color than copper phthalocyanine when wet pulverized alone. A pigment having a high degree is obtained (for example, see Patent Document 2). Further, a cyan colorant containing a specific ratio of a phthalocyanine compound having a substituent on the central metal atom and a phthalocyanine compound having no substituent on the central metal is disclosed (for example, see Patent Document 3).

  However, even in the colorant using two or more kinds of compounds described above, a toner that has high saturation in both the low-lightness cyan region and the high-lightness cyan region and has sufficient color reproducibility has not yet been realized. Not.

JP 2009-122496 A JP 2009-151162 A JP 2009-128750 A

  In general, if the reproducibility of the low lightness region is high, the reproducibility of the high lightness region is inferior, and if the high lightness region reproducibility is high, the reproducibility of the low lightness region is insufficient. In fact, cyan toner with a wide reproduction area has not been realized yet.

  The present invention solves the above-mentioned problems, and has an appropriate hue angle as a cyan color, has high saturation, and can develop a high saturation in a wide lightness region from a low lightness region to a high lightness region. The purpose is to provide cyan toner for use.

The above-described problems of the present invention are solved by the following configurations.
1. An electrostatic charge image developing toner containing at least a binder resin and a colorant comprising a zinc phthalocyanine compound, wherein the diffraction of the electrostatic charge image developing toner has a Bragg angle of 2θ with respect to a characteristic X-ray of CuKα. A cyan toner for developing an electrostatic charge image, wherein a C value calculated from the peak according to the formula (1) is 80 or more and 150 or less.
Formula (1)
C = (A × 100) / B
(In the formula (1), A represents the absolute intensity of the peak at the Bragg angle 2θ = 7.0 ± 0.1 °, and B represents the absolute intensity of the peak at the Bragg angle 2θ = 9.3 ± 0.1 °). To express.)
2. 2. The cyan toner for electrostatic image development according to 1 above, wherein the zinc phthalocyanine compound is represented by the following general formula (1).

(In the general formula (1), four A's each independently represent an atomic group forming an aromatic ring which may have a substituent.)

  According to the present invention, a cyan toner having a hue angle suitable as a cyan color, high saturation, and capable of reproducing a wide range of brightness from a low brightness area to a high brightness area can be obtained. In addition, an electrostatic image developing cyan toner having a sharp charge amount distribution and excellent development characteristics can be obtained.

It is an example of the X-ray diffraction spectrum of zinc phthalocyanine.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The cyan toner of the present invention is an X-ray diffraction spectrum and is characterized in that the C value calculated by the formula (1) from the diffraction peak of the Bragg angle 2θ with respect to the characteristic X-ray of CuKα is 80 or more and 150 or less.

Formula (1):
C = (A × 100) / B
(In the formula (1), A represents the absolute intensity of the peak at the Bragg angle 2θ = 7.0 ± 0.1 °, and B represents the absolute intensity of the peak at the Bragg angle 2θ = 9.3 ± 0.1 °). To express.)
If the C value is less than 80, the color saturation is low and the coloring property of the coloring material is insufficient, and if it exceeds 150, the lightness becomes too high and the coloring property of the coloring material is lowered.

  Further, the crystal of the zinc phthalocyanine compound of the present invention having a C value within the above range has a feature that the aspect ratio between the major axis and the minor axis is small. For this reason, since the dispersed particle diameter can be reduced, it is presumed that the charge amount distribution is sharpened without being exposed from the toner surface when used in toner. As a result, it is considered that the development characteristics of the individual toner particles are uniform, and excellent color reproduction characteristics can be exhibited from the low brightness area to the high brightness area.

  Hereinafter, the configuration of the present invention will be described in more detail, but the embodiments of the present invention are not limited thereto.

(Zinc phthalocyanine)
The zinc phthalocyanine compound used in the present invention is represented by the following general formula (1).

  In the general formula (1), four A's each independently represent an atomic group that forms an aromatic ring that may have a substituent. Four A's each independently represent an atomic group that forms an aromatic ring which may have a substituent. Specific examples of the atomic group include, for example, the following formula (A-1) to the following formula (A-29). ) Can be exemplified, preferably those represented by the following formula (A-1).

As a substituent in the atomic group A, 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, an alkoxy group such as —O (CH ₂ ) ₇ CH _3, and the like. .

  Specific examples of the zinc phthalocyanine compound of the present invention represented by the general formula (1) include the following compounds, but the zinc aphthalocyanine compound effective in the present invention is not limited thereto.

  (Exemplary compounds)

(Synthesis method)
Examples of the zinc phthalocyanine compound used in the present invention include, for example, Shirai-Kobayashi, published by IPC, “Phthalocyanine—Chemistry and Function” (P. 1-62), C.I. C. Leznoff-A. B. P. Lever co-authored, published by VCH, “Phthalogicanes-Properties and Applications” (P. 1-54), etc., can be synthesized by combining quoted or similar methods.

  The C value of the zinc phthalocyanine compound of the present invention can be controlled by adjusting the solvent, additive, temperature, precipitation rate and the like during crystal precipitation during synthesis. Further, as another method, it can be controlled by an acid paste process or a solvent salt milling process.

(Measurement of X-ray diffraction spectrum)
The X-ray diffraction spectrum of the cyan toner of the present invention is a Cu Kα ray as the X-ray, and the characteristic X-ray having a wavelength of 0.1514 nm (1.541Å) is used, whereby the X-ray diffraction pattern of the cyan toner of the present invention is used. And the X-ray diffraction pattern and coloring of the colorant itself used in the cyan toner of the present invention under the same measurement conditions as those for obtaining the X-ray diffraction pattern of the cyan toner of the present invention. An X-ray diffraction pattern of a toner constituent material other than the colorant (for example, a release agent) is obtained, and the X-ray diffraction pattern of the cyan toner of the present invention, the X-ray diffraction pattern of the colorant itself, and a toner constituent material other than the colorant ( For example, a method of confirming based on the X-ray diffraction pattern of the release agent) is used.

Here, the Bragg angle diffraction peak has an intensity of 0.5 × 10 ³ counts or more, a half-value width of 0.1 ° or more, and preferably 0.1 to 1.0 °.

  The X-ray diffraction pattern for confirming the Bragg angle diffraction peak of the cyan toner of the present invention is a Kα ray of Cu as the X-ray and a characteristic X-ray having a wavelength of 0.1514 nm (1.541Å). It can be measured by a meter.

  Examples of the X-ray diffractometer include “RINT-TTR” series, “RINT-Uitima” series, “RINT-2000” series, “MultiFlex” manufactured by Rigaku Corporation, and “X'Pert PRO MPD” manufactured by Panallytic. Etc. "can be suitably used.

  The X-ray diffraction pattern is 50 kV-300 mA (15 kW) when the glass sample plate or aluminum sample plate having a thickness of 0.5 mm or less is used as the sample. In the case of a type, measurement is performed by operating an X-ray diffractometer at an output of about 80% of the rated output at 40 kV-30 mA, and performing θ-2θ scanning with a concentrated optical system made of Bragg-Brentano.

  The slit conditions for this measurement are 2/3 ° for both the divergent slit and the convergent slit, and 0.3 mm or less for the light receiving slit. The scanning conditions are a scanning range of 5 to 45 ° and a scanning speed of 5 ° / min or less.

  The X-ray diffraction spectrum of FIG. 1 is an X-ray diffraction spectrum of a cyan toner using the zinc phthalocyanine of the present invention as a colorant.

  The addition amount of the cyan colorant comprising the zinc phthalocyanine compound of the present invention is preferably from 0.1 to 15 parts by weight, more preferably from 1 to 10 parts by weight, based on 100 parts by weight of the binder resin. Within this range, a desired image density can be obtained when the toner is used.

  In addition, the cyan toner of the present invention may be used in combination with other colorants, and the addition amount in that case may be within the above range in total.

(L ^* a ^* b ^* color system)
Next, the “L ^* a ^* b ^* color system” used in the present invention will be described.

The “L ^* a ^* b ^* color system” is a uniform color space defined by the CIE (International Commission on Illumination), and is a useful means for representing the color numerically. The L ^* a ^* b ^* table In the L ^* a ^* b ^* coordinate diagram showing the color space according to the color system, the L ^* axis direction represents lightness, the a ^* axis direction represents the hue of red-green direction, and the b ^* axis direction represents yellow-blue direction. Represents the hue of. The lightness refers to the relative brightness of the color, the hue refers to a hue such as red, yellow, green, blue, and purple, and the 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. Both a ^* and b ^* indicate that the color becomes brighter as the absolute value increases and becomes duller as the value 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 following equation (2).

Formula (2):
Saturation C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2
The larger the absolute value of the saturation C ^*, the brighter the color becomes, and the smaller the value, the darker the color.

Specifically, L ^* , a ^* , and b ^* are spectrophotometers “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth), a D65 light source as a light source, and a φ4 mm reflection measurement aperture, 380 to 730 nm are measured at 10 nm intervals, the viewing angle is set to 2 °, and the reference alignment is measured under the condition using a dedicated white tile.

  In the present invention, the hue angle h refers to, for example, a certain coordinate point (a, b) and origin 0 when an x-axis-y-axis plane representing the relationship between hue and saturation when the brightness takes a certain value is formed. Is the angle formed by the straight line extending in the + direction of the x-axis in the counterclockwise direction from the + direction (red direction) of the x-axis, and can be calculated by the following equation (3).

Formula (3):
Hue angle h = tan ⁻¹ (b ^* / a ^* )
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.

(Binder resin)
The binder resin contained in the cyan toner of the present invention is not particularly limited, and a known resin can be used.

  When the toner is manufactured by a pulverization method or the like, for example, a vinyl resin such as a styrene resin, a (meth) acrylic resin, a styrene- (meth) acrylic copolymer resin, a polyester resin, a polyamide resin, A polycarbonate resin, a polyether resin, a polyvinyl acetate resin, a polysulfone resin, an epoxy resin, a polyurethane resin, a urea resin, or the like can be used. These may be used alone or in combination of two or more.

  In addition, when each color toner is manufactured by suspension polymerization, emulsion aggregation, miniemulsion polymerization aggregation, or the like, it is known as a polymerizable monomer for obtaining a binder resin constituting the toner particles. Various polymerizable monomers can be used, and examples of the polymerizable monomer include vinyl monomers.

  Specific examples of the polymerizable monomer for obtaining the binder resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4- Dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, p- Styrene or styrene derivatives such as n-decylstyrene and pn-dodecylstyrene; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-methacrylate Octyl, 2-ethylhexyl methacrylate, stear methacrylate Methacrylic acid ester derivatives such as lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate , Acrylic acid ester derivatives such as isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, and phenyl acrylate; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, fluorine Vinyl halides such as 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 ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; Vinyl compounds such as vinyl naphthalene and vinyl pyridine; Acrylonitrile, methacrylate Examples thereof include vinyl monomers such as acrylic acid such as nitrile and acrylamide, and methacrylic acid derivatives. 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.

  Further, the toner of each color used in the cyan toner of the present invention may contain an internal additive such as a charge control agent and a release agent, and an external additive as 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 are used as long as they are colorless. be able to.

  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 1-20 mass parts.

(External additive)
As the cyan toner of the present invention, the toner particles can be used as they are. However, in order to improve the fluidity, chargeability, cleaning properties, etc. with respect to the toner particles, a fluidizing agent and a cleaning aid, etc. These external additives 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 toner. Various external additives may be used in combination.

(Toner production method)
In the cyan toner of the present invention, toner particles are obtained using a binder resin, a colorant, and an internal additive as required, and an external additive is added to the toner particles as necessary. Can be manufactured.

  Examples of the method for producing each color toner include a pulverization method, a suspension polymerization method, an emulsion aggregation method, and other known methods, but the emulsion aggregation method is preferably used. According to this emulsion aggregation method, the toner particles can be easily reduced in size from the viewpoint of production cost and production stability.

  Here, the emulsion aggregation method refers to a dispersion of binder resin fine particles (hereinafter also referred to as “binder resin fine particles”) produced by emulsification, as colorant fine particles (hereinafter referred to as “colorant fine particles”). ), And agglomerated until a desired toner particle diameter is obtained, and further, the shape is controlled by fusing the binder resin fine particles to produce toner particles. Here, the fine particles of the binder resin may optionally contain a release agent, a charge control agent, and the like.

An example of using the emulsion aggregation method as a method for producing the toner is shown below.
(1) Step of preparing a dispersion liquid in which colorant fine particles are dispersed in an aqueous medium (2) Dispersion liquid in which binder resin fine particles containing an internal additive are dispersed in an aqueous medium as necessary (3) A step of mixing the colorant fine particle dispersion and the binder resin fine particle dispersion and aggregating and fusing the colorant fine particles and the binder resin fine particles to form toner particles (4) ) A step of filtering out toner particles from a dispersion system (aqueous medium) of toner particles and removing a surfactant, etc. (5) A step of drying toner particles (6) A step of adding an external additive to the toner particles As a method for dispersing the binder resin fine particles in the step 2), it is preferable to use an emulsion polymer particle dispersion obtained by emulsion polymerization. The binder resin fine particles may have a multilayer structure of two or more layers made of binder resins having different compositions. For the binder resin fine particles having such a structure, for example, those having a two-layer structure, a dispersion of resin particles is prepared by emulsion polymerization treatment (first stage polymerization) according to a conventional method, and polymerization is started in this dispersion. An agent and a polymerizable monomer are added, and this system can be obtained by a technique of polymerization treatment (second stage polymerization).

  In addition, in the emulsion aggregation method, toner particles having a core-shell structure can be obtained. Specifically, the toner particles having a core-shell structure are first composed of binder resin fine particles and colorant fine particles for core particles. The core particles are prepared by agglomerating and fusing the core particles, and then the binder resin fine particles for the shell layer are added to the core particle dispersion to agglomerate and fuse the binder resin fine particles for the shell layer on the core particle surfaces. It can be obtained by forming a shell layer that coats the surface of the core particles.

  In particular, the cyan toner of the present invention is obtained by mixing a dispersion liquid in which colorant fine particles are dispersed in an aqueous medium and a dispersion liquid in which binder resin fine particles are dispersed in an aqueous medium to obtain colorant fine particles and It is preferably obtained by a process of aggregating and fusing the binder resin fine particles, that is, obtained by a production method such as an emulsion aggregation method.

  The particle diameter of the colorant fine particles in the step (1) of preparing the dispersion is preferably 10 to 300 nm in terms of volume-based median diameter.

(Measurement of dispersed particle size in colorant dispersion)
The dispersion particle diameter of the colorant fine particles in the aqueous medium is a volume average particle diameter, that is, a median diameter in a volume distribution. This median diameter is a value measured using “MICROTRAC UPA150” (manufactured by HONEYWELL).

(Measurement condition)
(1) Sample refractive index: 1.59
(2) 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.

An example of using a pulverization method as a cyan toner manufacturing method is shown below.
(1) Step of mixing binder resin, colorant and, if necessary, internal additive by Henschel mixer etc. (2) Step of kneading the resulting mixture while heating with an extrusion kneader etc. (3) obtained After coarsely grinding the kneaded product with a hammer mill or the like, and further crushing with a turbo mill or the like (4), the obtained pulverized product is finely classified using, for example, an airflow classifier utilizing the Coanda effect. Step of forming toner particles (5) Step of adding external additive to toner particles (particle diameter of toner particles)
The particle diameter of the toner particles of the present invention is preferably 4 to 10 μm, and more preferably 5 to 9 μm, for example, as a 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 the toner particles is an apparatus in which a computer system (Beckman Coulter) equipped with data processing software “Software V3.51” is connected to Coulter Counter Multisizer 3 (Beckman Coulter). Measure and calculate using

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 pipetted into a beaker containing ISOTON II (manufactured by Beckman Coulter, Inc.) in a sample stand until the measured instrument display concentration is 5% to 10%. By setting this concentration range, a reproducible measurement value can be obtained. In the measuring machine, the measurement particle count is set to 25000, the aperture diameter is set to 100 μm, the frequency value is calculated by dividing the measurement range of 2.0 to 60 μm into 256, and the volume integrated fraction is 50 % Particle diameter is defined as a volume-based median diameter (volume D ₅₀ % diameter).

(Temperant softening point temperature)
The toner of the present invention preferably has a softening point temperature (Tsp) of 70 to 130 ° C., more preferably 70 to 120 ° C. The colorant constituting the toner of each color used in 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 in the above range. As a result, the influence of heat applied to the 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, since the toner softening point temperature (Tsp) is in the above range, toner image fixing can be performed at a temperature lower than that of the prior art, and environmentally friendly image formation with reduced power consumption can be realized. Can do.

The softening point temperature (Tsp) 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 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.

(Measurement of softening point temperature)
As a method for measuring the softening point temperature (Tsp) of the toner, for example, “Flow Tester CFT-500 (manufactured by Shimadzu Corp.)” is used. While applying a pressure of 1.96 × 10 ⁶ Pa from the plunger and pushing it out from a nozzle with a diameter of 1 mm and a length of 1 mm, the curve between the plunger drop amount and temperature of the flow tester (softening flow curve) The temperature that flows out first is defined as the melting start temperature, and the temperature corresponding to the drop of 5 mm is defined as the softening point temperature.

(Toner glass transition point)
The toner of the present invention preferably has a glass transition point (Tg) of 20 to 90 ° C, more preferably 30 to 65 ° C.

(Measurement of glass transition point)
The glass transition temperature of the toner of the present invention can be measured using a DSC-7 differential scanning calorimeter (manufactured by PerkinElmer) and a TAC7 / DX thermal analyzer controller (manufactured by PerkinElmer).

  As a measurement procedure, toner 4.5 mg to 5.0 mg is precisely weighed to two decimal places, sealed in an aluminum pan (KITNO.0219-0041), and set in a DSC-7 sample holder. The reference used an empty aluminum pan. The measurement conditions are as follows: measurement temperature 0 ° C. to 200 ° C., temperature increase rate 10 ° C./min, temperature decrease rate 10 ° C./min, with heat-cool-heat temperature control, and analysis based on 2nd Heat data Went.

  The glass transition temperature is obtained by drawing an extension of the baseline before the rise of the first endothermic peak and a tangent line indicating the maximum slope between the rise portion of the first peak and the peak apex, and the intersection is determined by the glass transition temperature ( (Glass transition point).

(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, and 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.

(Transfer material)
As a transfer material used for image formation using the cyan toner of the present invention, 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 Various types of plastic films, cloths, etc. for OHP can be mentioned, but are not limited thereto.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Zinc phthalocyanine]
In the examples, zinc phthalocyanine of Table 1 having different C values was used for the zinc phthalocyanine of the exemplary compound (Y-1).

[Colorant fine particle dispersion adjustment process]
(1) 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 aqueous surfactant solution, 15 parts by mass of compound (1) are gradually added, and dispersion treatment is performed using “Clearmix W Motion CLM-0.8” (manufactured by M Technique Co., Ltd.). A fine particle dispersion [1] was prepared.

The volume-based median diameter of the fine particles in the colorant fine particle dispersion [1] was 174 nm.
(2) Adjustment of Colorant Fine Particle Dispersion [2], [3] In the adjustment of Colorant Dispersion [1], except that Compound (1) is changed to Compound (2), (3) as the colorant. Thus, colorant fine particle dispersions (2) and (3) were prepared.

[Cyan toner preparation example 1 (emulsion aggregation method)] (Toners [1] and [2] were replaced)
(1) Production Example of Core Part Resin Particles [1] Core part resin particles [1] having a multilayer structure were produced through the first stage polymerization, second stage polymerization, and third stage polymerization shown below.

(A) First stage polymerization (Preparation of resin particles [A1])
A surfactant solution prepared by dissolving 4 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate in 3040 parts by mass of ion-exchanged water in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction apparatus. The internal temperature was raised to 80 ° C. while stirring and stirring at a stirring speed of 230 rpm under a nitrogen stream. To this surfactant solution, a polymerization initiator solution in which 10 parts by mass of a polymerization initiator (potassium persulfate: KPS) was dissolved in 400 parts by mass of ion-exchanged water was added to a temperature of 75 ° C., and then 532 masses of styrene. A monomer mixture consisting of 1 part by weight, 200 parts by weight of n-butyl acrylate, 68 parts by weight of methacrylic acid, and 16.4 parts by weight of n-octyl mercaptan was dropped over 1 hour, and this system was kept at 75 ° C. for 2 hours. Polymerization (first stage polymerization) was carried out by heating and stirring to produce resin particles [A1]. The mass average molecular weight (Mw) of the resin particles [A1] produced by the first stage polymerization was 16,500.

(B) Second-stage polymerization (formation of intermediate layer: production of resin particles [A2])
In a flask equipped with a stirrer, a monomer mixture comprising 101.1 parts by mass of styrene, 62.2 parts by mass of n-butyl acrylate, 12.3 parts by mass of methacrylic acid, and 1.75 parts by mass of n-octyl mercaptan In addition, 93.8 parts by mass of paraffin wax “HNP-57” (manufactured by Nippon Seiki Co., Ltd.) was added as a release agent, and the mixture was heated to 90 ° C. and dissolved.

  On the other hand, a surfactant solution in which 3 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate was dissolved in 1560 parts by mass of ion-exchanged water was heated to 98 ° C., and resin particles [A1] 32 were added to the surfactant solution. .8 parts by mass (solid content conversion) was added, and the monomer solution containing the paraffin wax was mixed and dispersed for 8 hours by a mechanical disperser “CLEAMIX” (manufactured by M Technique Co., Ltd.) having a circulation path. A dispersion liquid containing emulsion particles having a dispersion particle diameter of 340 nm was prepared. 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 this emulsified particle dispersion, and the system was polymerized by heating and stirring at 98 ° C. for 12 hours. (Second-stage polymerization) was performed to produce resin particles [A2]. The Mw of the resin particles [A2] prepared by the second stage polymerization was 23,000.

(C) Third-stage polymerization (formation of outer layer: preparation of core part resin particles [1])
A polymerization 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 resin particles [A2], and 293.8 parts by mass of styrene under a temperature condition of 80 ° C., n -A monomer mixed solution consisting of 154.1 parts by mass of butyl acrylate and 7.08 parts by mass of n-octyl mercaptan was added dropwise over 1 hour. After completion of dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain core part resin particles [1]. In addition, Mw of the resin particle for core part [1] was 26,800. The volume average particle diameter of the core part resin particles [1] was 125 nm. Furthermore, the glass transition temperature (Tg) of the resin particles for core part [1] was 28.1 ° C.
(2) Production Step of Resin Particle [1] for Shell Layer In the first stage polymerization of the resin particle for core [1], 548 parts by mass of styrene, 156 parts by mass of 2-ethylhexyl acrylate, and 96 parts by mass of methacrylic acid Parts and n-octyl mercaptan were used in the same manner except that the monomer mixture was changed to 16.5 parts by mass to carry out the polymerization reaction and the post-reaction treatment, thereby producing shell layer resin particles [1]. . The Tg of the resin particles [1] for shell layer was 53.0 ° C.
(3) Preparation Step of Toner Particles [1] (a) Formation of Core Portion Resin Particles for Core Portion [1] 420 parts by mass (in terms of solid content), 900 parts by mass of ion-exchanged water, and colorant fine particle dispersion [ 3] 200 parts by mass were stirred in a reaction vessel equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. After adjusting the temperature in the reaction vessel 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 60 parts by mass of magnesium chloride hexahydrate in 60 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, temperature increase was started, and the system was heated to 80 ° C. over 80 minutes. In this state, the particle size of the associated particles was measured with “Coulter Multisizer 3” (manufactured by Coulter), and when the median diameter (D ₅₀ ) on the volume basis of the associated particles became 6.3 μm, sodium chloride 40 .2 parts by weight of an aqueous solution obtained by dissolving 1000 parts by weight of ion-exchanged water is added to stop the growth of the particle size, and the fusion is continued by heating and stirring at a liquid temperature of 80 ° C. for 1 hour as an aging treatment. The core part [1] was formed. In addition, it was 0.930 when the circularity of core part [1] was measured in "FPIA2100" (made by Systex).

(B) Formation of shell layer (production of toner particles [1])
Next, at 65 ° C., 46.8 parts by mass of the resin particles for shell layer [1] (in terms of solid content) were added, and an aqueous solution in which 2 parts by mass of magnesium chloride hexahydrate was dissolved in 20 parts by mass of ion-exchanged water. After the addition over 10 minutes, the temperature was raised to 80 ° C. (shelling temperature), and stirring was continued for 1 hour to melt the resin particles [1] for the shell layer on the surface of the core [1]. After the deposition, an aging treatment was performed at 80 ° C. to a predetermined circularity to form a shell layer. Here, 40.2 parts by mass of sodium chloride was added, the mixture was cooled to 30 ° C. at 8 ° C./min, the produced fused particles were filtered, washed repeatedly with ion exchange water at 45 ° C., and then 40 ° C. By drying with warm air, toner particles [1] having a shell layer on the surface of the core part and having a volume-based median diameter (D ₅₀ ) of 6.5 μm and Tg of 31 ° C. were obtained.
(4) External additive addition process (preparation of toner [1])
The following external additives are added to 100 parts by mass of toner particles [1], and the peripheral speed of the stirring blade is 35 m / sec, the processing temperature is 35 ° C., and the processing time is 15 minutes using “Henschel mixer” (manufactured by Mitsui Miike Mining Co., Ltd.). Cyan toner [1] was prepared by performing external addition treatment under the conditions.

-Hexamethyldisilazane-treated silica (average primary particle size 12 nm) 0.6 parts by mass-N-octylsilane-treated titanium dioxide (average primary particle size 24 nm) 0.8 parts by mass The softening point of cyan toner [1] is It was 107 ° C.

[Cyan toner production example 2 (pulverization method)]
(1) Mixing step The following materials were mixed with a “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.) at a peripheral speed of a stirring blade of 25 m / sec over 5 minutes to obtain a mixture.

Polyester resin 100 parts by mass (bisphenol A-ethylene oxide adduct, terephthalic acid, trimellitic acid condensate, mass average molecular weight Mw 20,000)
-Colorant (compound (3)) 3 parts by mass-Carnauba wax (manufactured by Celerica NODA) 3 parts by mass (2) Kneading step The resulting mixture was kneaded while being heated to 120 ° C by a twin-screw extrusion kneader and kneaded. After that, the kneaded product was cooled.
(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).
(4) Classification process The obtained fine powder was finely classified by an air classifier to obtain toner particles [2] composed of toner particles having a volume average particle diameter of 8.0 μm.
(5) External additive addition step The following external additive is added to 100 parts by mass of toner particles [2], and the peripheral speed of the stirring blade is 35 m / sec, treatment temperature by “Henschel mixer” (manufactured by Mitsui Miike Mining Co., Ltd.). An external addition process was performed under conditions of 35 ° C. and a processing time of 8 minutes to prepare cyan toner [2].

-0.4 parts by mass of hexamethyldisilazane-treated silica (average primary particle size 12 nm)-0.8 parts by mass of n-octylsilane-treated titanium dioxide (average primary particle size 24 nm) The softening point of cyan toner [2] is It was 110 ° C.

[Production Example 3 of Cyan Toner (Production of Comparative Toner)]
In the production of cyan toner [2], the colorant was changed to compound (1) to produce cyan toner [3]. This was used for comparison.

[Cyan toner production examples 3 and 4 (production of comparative toner)]
Cyan toners [4] and [5] were produced in the same manner as in the production of cyan toner [1] except that compounds (1) and (2) were used as the colorants. This was used for comparison.

[Production of Developers [1] to [5]]
A ferrite carrier having a volume average particle size of 50 μm coated with a silicone resin is mixed with the “cyan toners [1] to [5]” so that the toner concentration is 6% by mass, thereby forming a two-component developer. “Developers [1] to [5]” were prepared.

≪Evaluation method≫
[Saturation of cyan toner]
(Evaluation of color reproduction range of full color image)
(1) Color reproduction range In an environment of a temperature of 20 ° C. and a humidity of 50% RH, a cyan developer [1] to [5] using a full-color high-speed multifunction device “bizhub C6500 (manufactured by Konica Minolta Business Technologies)” The image output of the ECI2002VCMYK chart is “POD gloss coated paper” under the condition that the fixing linear speed is set to 310 mm / min (about 65 sheets / min) using “bizhub C6500” yellow developer and magenta developer. 128 g / m ² "(manufactured by Oji Paper Co., Ltd.). For each output image patch, a spectrophotometer “Gretag Macbeth Spectrolino” (manufactured by Gretag Macbeth) is used, a D65 light source as a light source, a φ4 mm reflection measurement aperture, a viewing angle of 2 °, and a dedicated reference adjustment It shall be measured under conditions using white tiles. Here, in the L ^* a ^* b ^* color space, the hue angle range of 210 to 240 degrees is defined as the color gamut area of the color where L ^* is 50 or more, and the L ^* is 50. The color gamut area was evaluated by setting the color gamut area of the lower color as the area of the low lightness cyan area and the color gamut area when the developer of the comparative cyan toner [3] was used as 100. The color gamut area here was evaluated as an acceptable level of 105 or more. The results are shown in Table 3.

The “L ^* a ^* b ^* color system” is a means that is useful for expressing a color numerically. L: direction represents lightness, and a ^* axis direction represents a hue in the red-green direction. B ^{* The} axis direction represents the hue in the yellow-blue direction.

  As is apparent from the results in Table 3, the cyan toners [1] and [2] of the present invention have higher saturation in the low lightness to high lightness regions than the comparative cyan toners [3] to [5]. I understand.

A Peak at Bragg angle 2θ = 7.0 ± 0.1 ° B Peak at Bragg angle 2θ = 9.3 ± 0.1 °

Claims (2)

An electrostatic charge image developing toner containing at least a binder resin and a colorant comprising a zinc phthalocyanine compound, wherein the diffraction of the electrostatic charge image developing toner has a Bragg angle of 2θ with respect to a characteristic X-ray of CuKα. A cyan toner for developing an electrostatic charge image, wherein a C value calculated from the peak according to the formula (1) is 80 or more and 150 or less.
Formula (1)
C = (A × 100) / B
(In the formula (1), A represents the absolute intensity of the peak at the Bragg angle 2θ = 7.0 ± 0.1 °, and B represents the absolute intensity of the peak at the Bragg angle 2θ = 9.3 ± 0.1 °). To express.) The cyan toner for developing electrostatic images according to claim 1, wherein the zinc phthalocyanine compound is represented by the following general formula (1).

(In the general formula (1), four A's each independently represent an atomic group forming an aromatic ring which may have a substituent.)

Images