JP2006267741A - Electrophotographic magenta toner, and full-color image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic magenta toner which is excellent in image quality by using a specific pigment and is satisfactory in environmental difference of electrostatic charge characteristics, and a full-color image forming method using the same. <P>SOLUTION: The electrophotographic magenta toner containing at least a binder resin and a colorant comprises containing at least a quinacridone based pigment having Ca intensity in fluorescent X-ray analysis ranging from 50 to 150 kcps, and a naphthol based pigment having a 2 to 5° range in the sum of the half band width of the peak higher than 25% in the relative intensity to the intensity of the maximum peak in the X-ray diffraction pattern of a Bragg angle ranging from 0 to 35° as the colorant. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic magenta toner (hereinafter, simply referred to as “toner”) used in an apparatus utilizing an electrophotographic process such as a copying machine, a printer, a facsimile, etc., particularly a color copying machine, and The present invention relates to the full-color image forming method used.

  In the electrophotographic process, a latent image is electrically formed by various means on a photoconductor (electrostatic latent image carrier) using a photoconductive substance, and this latent image is developed with toner, and is exposed to light. The toner image on the body is transferred to a recording medium such as paper with or without an intermediate transfer member, and then the transferred image is heated, pressurized, heated and pressurized, or solvent vapor is used. A fixed image is formed through a plurality of steps of fixing. The toner remaining on the photoreceptor is cleaned by various methods as necessary, and the plurality of steps are repeated.

  In recent years, due to technological advances in the field of electrophotography, such electrophotographic processes have been used not only for copying machines and printers, but also for printing applications. However, it has been demanded more and more to have high image quality and hue equivalent to printed matter.

  Furthermore, in order to achieve such requirements, various proposals have been made regarding toners from various aspects such as the binder resin melting characteristics, colorant type, particle size distribution, and external additives. Specifically, for example, a technique for achieving both hue and high reliability by using a specific pigment (see, for example, Patent Document 1) and a technique for reproducing a wide hue by using a specific toner have been proposed. (For example, refer to Patent Document 2).

  Among color toners used for full-color image formation, red and magenta are important because they have a high effect of improving the image impression. As a representative example of color reproduction of printing, there is Japan Color (JAPAN COLOR). Japan Color was established mainly by the ISO / TC130 National Committee, and is a common color index as a color standard tool for offset sheet-fed printing. The standard of the color gamut is Japan Color Standard Colorimetric Value (JAPAN COLOR SOLID VALUE), and the goal is to reproduce this even in electrophotography. On the other hand, energy saving is also important in recent years, and in the electrophotographic process, reduction of power consumption (fixing at a low temperature) in the fixing process that consumes the most power is a major issue.

  As magenta toner, a technique for improving the blackness of a cyan, yellow, magenta three-color superimposed image by using a quinacridone pigment having an average particle size of 0.5 μm or less is disclosed (for example, refer to Patent Document 3). ). In addition, a technique for improving the sharpness of an image by using a suspension polymerization toner using a quinacridone pigment is disclosed (for example, see Patent Document 4). As described above, quinacridone pigments are generally used.

  In addition, when forming a multi-color image, a technique for improving the sharpness by using a monoazo red pigment, and an average particle size D50 by cumulative volume distribution is 0.05 μm ≦ D50 ≦ 0.2 μm. A technique for improving spectral reflection characteristics and other toner characteristics by containing a monoazo pigment having a structure is disclosed (for example, see Patent Documents 5 and 6). Furthermore, a technique for improving pigment dispersibility by using a polymerized toner containing a naphthol pigment has been disclosed (for example, see Patent Document 7). These also relate to monoazo red pigments (including naphthol pigments) and are generally used.

  As a combination of a quinacridone pigment and a naphthol pigment, a technique for improving the color reproducibility of a secondary color by using an insoluble azo pigment and a quinacridone pigment in a liquid developer (see, for example, Patent Document 8), A technique for improving color reproducibility, gradation and the like by using a toner containing a pigment and a naphthol pigment and having a toner shape factor of 0.95 or more is disclosed (for example, see Patent Documents 8 and 9). ).

  On the other hand, the usage environment of copiers and printers varies greatly. To obtain high reliability under such circumstances, the charging characteristics must be kept constant in any environment. Toners that are less environmentally dependent are needed. In recent years, copying machines and printers are required to have higher speeds, and the required performance of the release agent is also limited. That is, a release agent having a low melt viscosity is used. This low melt viscosity release agent has a larger domain growth in the toner fusion process than the high melt viscosity release agent, which affects the dispersion of the pigment in the toner, thus affecting the color reproducibility. Sometimes. In that case, it is necessary to make the dispersibility of the pigment in the toner better than ever.

However, in any of the above-described techniques, the dispersibility of the pigments is insufficient when both pigments are used, and it is impossible to achieve both the adjustment of the hue and the stabilization of the charging characteristics, resulting in higher image quality, No magenta toner suitable for low-temperature fixing was obtained.
JP-A-5-142867 JP 2000-199982 A JP-A-1-154161 JP-A-2-32365 JP 62-296167 A JP-A-11-272014 JP 2001-249498 A JP-A-4-226477 JP 2002-156895 A

An object of the present invention is to solve the conventional problems and achieve the following objects.
That is, an object of the present invention is to provide an electrophotographic magenta toner having excellent image quality by using a specific pigment and having a good environmental difference in charging characteristics, and a full-color image forming method using the same. .

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> A magenta toner for electrophotography containing at least a binder resin and a colorant,
As the colorant, at least a structure represented by the following general formula (1), a quinacridone pigment having a Ca intensity in the range of 50 to 150 kcps in a fluorescent X-ray analysis, and a structure represented by the following general formula (2) And a naphthol pigment having a sum of half widths of peaks having a relative intensity with respect to the intensity of the maximum peak in the X-ray diffraction pattern having a Bragg angle of 0 to 35 ° in the range of 0 to 35 ° is in the range of 2 to 5 °. An electrophotographic magenta toner.

<2> A release agent is further included, and an average dispersion diameter of the release agent in the cross section of the toner by observation with a transmission electron microscope image is in a range of 150 to 1500 nm, and an area occupied by the release agent in the cross section of the toner is The magenta toner for electrophotography according to <1>, which is in the range of 10 to 35% of the entire cross-sectional area.

<3> When the binder resin contains a crystalline polyester resin and an amorphous polyester resin, the average primary particle size of the quinacridone pigment is Pq50, and the average primary particle size of the naphthol pigment is Pn50. The magenta toner for electrophotography according to <2>, which satisfies the relationship of the following formula (1).
20 nm <Pq50 <Pn50 <150 nm Formula (1)

<4> The melting point of the crystalline polyester resin is in the range of 50 to 120 ° C., and the content of the crystalline polyester resin in the binder resin is in the range of 3 to 30% by mass. <2> or <3> The magenta toner for electrophotography described in 1.

<5> 80% by mass or more of the naphthol pigment is C.I. I. Pigment Red 269, and 80% by mass or more of the quinacridone pigment is C.I. I. The magenta toner for electrophotography according to any one of <2> to <4>, which is CI Pigment Red 122.

<6> The magenta toner for electrophotography according to any one of <2> to <5>, wherein the crystalline polyester resin includes a monomer having a sulfonic acid group as a structural unit.

<7> In any one of <2> to <6>, containing at least one metal element selected from aluminum, iron, zinc, and calcium in a range of 0.01 to 0.5% in terms of element composition ratio The magenta toner for electrophotography described.

<8> The magenta toner for electrophotography according to any one of <1> to <7>, wherein the content of the quinacridone pigment and the naphthol pigment is in the range of 4 to 20% by mass.

<9> The magenta toner for electrophotography according to any one of <1> to <8>, wherein a mass ratio of the quinacridone pigment and the naphthol pigment is in a range of 80:20 to 30:70. .

<10> Polyalkylene is included as the release agent, and the viscosity η140 at 140 ° C. of the polyalkylene according to an E-type viscometer is in the range of 1.5 to 5.0 mPa · s. <1> to <10> The magenta toner for electrophotography according to any one of the above.

<11> Obtained by a wet manufacturing method including an aggregating step of forming aggregated particles in a dispersion in which at least resin particles and colorant particles are dispersed, and a fusion step of fusing the aggregated particles by heating the aggregated particles The electrophotographic magenta toner according to any one of <1> to <10>.

<12> a step of forming an electrostatic latent image on the electrostatic latent image carrier, a step of developing the electrostatic latent image with an electrostatic latent image developer containing toner to form a toner image, and the toner <1> to <11> As a magenta toner among the toners, a full color image forming method including a step of transferring an image onto a transfer medium and a step of thermally fixing the toner image onto a recording medium. A full-color image forming method using the electrophotographic magenta toner described in 1).

<13> A fixing device including a fixing member in which the step of thermally fixing the toner image includes a pair of rotating members that come into contact with the front and back of the recording medium, and at least one of the pair of rotating members is a belt member. <12> The full color image forming method according to <12>.

  According to the present invention, it is possible to provide a magenta toner for electrophotography that is excellent in image quality and has a good environmental difference in charging characteristics by using a specific pigment, and a full-color image forming method using the same.

Hereinafter, the present invention will be described in detail.
The electrophotographic magenta toner of the present invention is an electrophotographic magenta toner containing at least a binder resin and a colorant, and has at least a structure represented by the following general formula (1) as the colorant, A quinacridone pigment having a Ca intensity in the range of 50 to 150 kcps in X-ray analysis and a maximum peak in an X-ray diffraction pattern having a structure represented by the following general formula (2) and a Bragg angle in the range of 0 to 35 ° It comprises a naphthol pigment having a sum of the half-widths of peaks having a relative intensity to the intensity of more than 25% in the range of 2 to 5 °.

  In general, various additives may be added to commercially available pigments in order to impart dispersion stability and colorability. In particular, it is known that quinacridone derivative pigments (quinacridone pigments) generally used as magenta pigments are often added with a rosin salt as an additive for the above purpose. For example, when used as a colorant for paints, printing inks, etc., it is added from several mass% to several tens of mass% with respect to the pigment for the purpose of improving the dispersibility in a binder or a solvent and consequently improving the colorability. Yes.

In particular, as the rosin salt, colorless rosin calcium is used for this purpose, and after pigment synthesis, it is known that a rosin solution is added to the pigment to make it exist on the pigment surface ( “Colored material optical handbook”, edited by Color Materials Association, Asakura Shoten, published on 25 November 1989).
From this point of view, when the toner is prepared by a wet method described later, the rosin calcium is usually added to the colorant dispersion in order to improve the dispersibility of the quinacridone pigment.

  Therefore, when a fluorescent X-ray analysis is performed on the quinacridone pigment taken out from the colorant dispersion, calcium (Ca) is detected, and thus the magenta toner particles produced contain the above-mentioned detected amount of Ca. This will include quinacridone pigments.

  However, some calcium (Ca) in rosin calcium dissolves in the solvent during toner preparation, and coordinates with the charging site of the binder resin to invalidate the charging site. When the amount is large, good toner chargeability cannot be obtained.

In general, it is known that the charging characteristics of a toner produced by an emulsion aggregation method and the like are lowered due to the influence of moisture in the atmosphere in a high temperature and high humidity environment. The toner whose charging site is invalidated due to the Ca being invalidated due to Ca becomes more susceptible to moisture in a high temperature and high humidity environment, and therefore the charge amount in a low temperature and low humidity environment and in a high temperature and high humidity environment is low. The difference increases.
In the aggregation process described later, Ca ions migrate into the medium. Therefore, even if a shell structure is formed on the toner particles, the influence on the charging characteristics cannot be prevented.

  As a result of intensive studies by the present inventors, as the Ca content in the quinacridone pigment represented by the general formula (1) subjected to the rosin calcium treatment, the Ca intensity in the fluorescent X-ray analysis is in the range of 50 to 150 kcps. By doing so, it was found that the dispersibility of the pigment and the toner chargeability can both be achieved. That is, if the Ca intensity in the fluorescent X-ray analysis is less than 50 kcps, the quinacridone pigment is not sufficiently dispersed in the toner particles. On the other hand, if it exceeds 150 kcps, the toner charging characteristics are adversely affected.

The Ca strength is preferably in the range of 70 to 120 kcps, more preferably in the range of 80 to 100 kcps.
The Ca strength of the toner containing a quinacridone pigment having a Ca strength in the range of 50 to 150 kcps is preferably in the range of 1 to 10 kcps.

The Ca content in the quinacridone pigment is measured by the following method.
First, an aluminum ring is filled with a sample, and pressure-molded with an automatic press to prepare a sample for analysis. Next, using a fluorescent X-ray analyzer (Nippon Philips, PW1404 / 10 type machine), the Ca intensity was measured according to the Ca intensity measurement program.

  In the present invention, in addition to the quinacridone pigment, a naphthol pigment represented by the general formula (2) is further used in order to widen the color gamut of the magenta toner and improve the image quality. In the present invention, the sum of the half widths of the peaks (including the maximum peak) having a relative intensity to the maximum peak intensity in the X-ray diffraction pattern of the naphthol pigment in the Bragg angle range of 0 to 35 ° is 2%. A range of ˜5 ° is necessary for high image quality.

  The reason why high image quality can be obtained is assumed as follows. The half width of the X-ray diffraction pattern is an index of crystallinity (crystallinity). That is, if the sum of the half-value widths is greater than 5, the pigment crystal as a whole becomes more amorphous, which is disadvantageous for improving dispersibility in the toner. On the other hand, when the sum of the half widths is smaller than 2, it is stabilized as a crystal, which is disadvantageous for producing a dispersion. Therefore, it is necessary to use a pigment having an appropriate sum of half widths.

The sum of the half widths is preferably in the range of 2.5 to 4.5 °, and more preferably in the range of 3 to 4 °.
The full width at half maximum in the X-ray diffraction pattern of the naphthol pigment is obtained as follows. That is, measurement is performed from a Bragg angle (2θ) of 0 ° to 35 ° with an X-ray diffractometer (manufactured by Rigaku Corporation, MiniFlex) using a Kα ray of Cu characteristic X-ray as a radiation source. It can be obtained from the peak.

Furthermore, in the present invention, in the case of wet toner preparation, the quinacridone pigment is added to the quinacridone pigment in a fusion process in which the final fusion is performed at a temperature higher than the glass transition point of the resin (melting point when a crystalline resin is included). It has been found that Ca, the residue of rosin calcium to be treated, favors maintaining dispersibility in toner particles, especially in the hot state, of naphthol pigments, as is the case for quinacridone pigments. It was done.
Therefore, with the quinacridone pigment and naphthol pigment having the configuration as in the present invention, the dispersibility of the pigment in the toner particles can be improved particularly in the toner preparation by the wet method. Can be improved.

Next, each configuration of the electrophotographic magenta toner of the present invention will be described.
The toner of the present invention contains at least a binder resin and a colorant. Binder resins used include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; Α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers such as vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone; Can.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-maleic anhydride copolymer. Examples thereof include a polymer, polyethylene, and polypropylene. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

The binder resin is preferably excellent in sharp melt property at the time of fixing, and from the viewpoint of obtaining low-temperature fixability and high glossiness in a fixed image, it is preferable to use an amorphous resin and a crystalline resin in combination.
The amorphous resin has only a stepwise endothermic change, not a clear endothermic peak, in a thermal analysis measurement using differential scanning calorimetry (DSC). It refers to those that are thermoplasticized at temperatures above that. The crystalline resin refers to a resin having a clear endothermic peak, not a stepwise change in endothermic amount in differential scanning calorimetry (DSC).

As the amorphous resin, each of the exemplified resins can be used, but from the viewpoint of toner chargeability, it is preferable to use an amorphous polyester resin.
The crystalline resin is not particularly limited as long as it is a resin having crystallinity, and specifically includes a crystalline polyester resin, a crystalline vinyl resin, and the like. A crystalline polyester resin is preferred from the viewpoint of chargeability and adjustment of the melting point within a preferred range. An aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the present invention, the “acid-derived component” refers to an acid component before synthesis of the polyester resin. The “alcohol-derived constituent component” refers to a constituent portion that was an alcohol component before the synthesis of the polyester resin. In the present invention, in the case of a polymer obtained by copolymerizing another component with the crystalline polyester main chain, when the other component is 50% by weight or less, this copolymer is also called a crystalline polyester.

  The acid-derived constituent component is preferably an aliphatic dicarboxylic acid, and particularly preferably a linear carboxylic acid. Examples of the linear carboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10- Decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecane Dicarboxylic acid, etc., or lower alkyl esters and acid anhydrides thereof. Among these, those having 6 to 10 carbon atoms are preferable from the viewpoint of crystal melting point and chargeability. In order to increase the crystallinity, these linear dicarboxylic acids are preferably used in an amount of 95 mol% or more, more preferably 98 mol% or more of the acid component.

  The other monomer is not particularly limited. For example, a conventionally known divalent or carboxylic acid which is a monomer component as described in Polymer Data Handbook: Basics (Science of Polymer Science: Bafukan). And divalent alcohol. Specific examples of these monomer components include divalent carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, and cyclohexanedicarboxylic acid. And dibasic acids such as these, anhydrides thereof, and lower alkyl esters thereof. These may be used individually by 1 type and may use 2 or more types together.

As the acid-derived constituent component, in addition to the above-mentioned aliphatic dicarboxylic acid-derived constituent component, a constituent component such as a dicarboxylic acid-derived constituent component having a sulfonic acid group is preferably included.
The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when a resin particle dispersion is prepared by emulsifying or suspending the entire resin in water, if a sulfonic acid group is present, it can be emulsified or suspended without using a surfactant as described later. Examples of such a dicarboxylic acid having a sulfone group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt is preferable in terms of cost. The content of the dicarboxylic acid having a sulfonic acid group is preferably 0.1 to 2.0 mol%, and more preferably 0.2 to 1.0 mol%. When the content is more than 2 mol%, the chargeability may be deteriorated. In the present invention, “constituent mol%” refers to a percentage when each constituent component (acid-derived constituent component, alcohol-derived constituent component) in the polyester resin is 1 unit (mol).

  The alcohol component is preferably an aliphatic dialcohol, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-dodecanediol, 1,12-undecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,20-eicosanediol, etc., among which those having 6 to 10 carbon atoms are preferred from the viewpoint of crystal melting point and chargeability. In order to enhance crystallinity, these linear dialcohols are preferably used in an amount of 95 mol% or more, more preferably 98 mol% or more of the alcohol constituent.

  Other divalent dialcohols include, for example, bisphenol A, hydrogenated bisphenol A, ethylene oxide or (and) propylene oxide adducts of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, diethylene glycol, Examples include propylene glycol, dipropylene glycol, 1,3-butanediol, and neopentyl glycol. These may be used individually by 1 type and may use 2 or more types together.

  If necessary, monovalent acids such as acetic acid and benzoic acid, monovalent alcohols such as cyclohexanol and benzyl alcohol, benzenetricarboxylic acid, and naphthalenetricarboxylic acid for the purpose of adjusting the acid value and hydroxyl value. And trihydric alcohols such as anhydrides thereof, lower alkyl esters thereof, glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol can also be used.

  The polyester resin can be used in any combination of the monomer components described above, for example, polycondensation (chemical doujin), polymer experiment (polycondensation and polyaddition: Kyoritsu Publishing) and polyester resin handbook (edited by Nikkan Kogyo Shimbun). And the like, and a transesterification method, a direct polycondensation method, and the like can be used alone or in combination. The molar ratio (acid component / alcohol component) for reacting the acid component with the alcohol component varies depending on the reaction conditions and the like, so it cannot be generally stated, but in the case of direct polycondensation, usually about 1/1. In the case of the transesterification method, ethylene glycol, neopentyl glycol, cyclohexanedimethanol, etc. are often used in excess of monomers that can be distilled off under vacuum. The production of the polyester resin is usually performed at a polymerization temperature of 180 to 250 ° C., and the reaction system is subjected to a reaction while reducing the pressure in the reaction system as necessary to remove water and alcohol generated during the condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. If there is a monomer with poor compatibility in the copolymerization reaction, the monomer with poor compatibility and the monomer and the acid or alcohol to be polycondensed may be condensed in advance before polycondensation with the main component. .

  Catalysts that can be used in the production of the polyester resin include alkali metal compounds such as sodium and lithium, alkaline earth metal compounds such as magnesium and calcium, and metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium. , Phosphorous acid compounds, phosphoric acid compounds, amine compounds, etc., specifically, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, stearic acid Zinc, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, trib Ruantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, zirconium naphthenate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Examples of the compound include phosphite, tris (2,4-di-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, and triphenylamine. Among these, a tin-based catalyst and a titanium-based catalyst are preferable from the viewpoint of chargeability, and among them, dibutyltin oxide is preferably used.

  The melting point of the crystalline polyester resin is 50 to 120 ° C, preferably 60 to 110 ° C. When the melting point is lower than 50 ° C., the storage stability of the toner and the storage stability of the toner image after fixing become a problem. On the other hand, when the temperature is higher than 120 ° C., sufficient low-temperature fixing cannot be obtained as compared with the conventional toner. In the present invention, the melting point of the crystalline polyester resin is measured using a differential scanning calorimeter (DSC) to be described later. When a plurality of melting peaks are shown, the maximum peak is regarded as the melting point.

  The crystalline polyester resin preferably has a weight average molecular weight in the range of 5000 to 50000, more preferably in the range of 10000 to 30000, as measured by GPC. If the molecular weight is too small, the effect of plasticizing the toner is increased and the offset is deteriorated. When the molecular weight is too large, the melt viscosity of the toner becomes high and the low-temperature fixability deteriorates.

  The acid value of the crystalline polyester resin is preferably 3.0 to 25.0 mgKOH / g. More preferably, it exists in the range of 6.0-20.0 mgKOH / g, More preferably, it exists in the range of 9.0-18.0 mgKOH / g. If the acid value is lower than 3.0 mgKOH / g, the stability as a resin particle at the time of aggregation is poor, and if it exceeds 25.0 mgKOH / g, the hygroscopicity of the toner increases and the toner is easily affected by the environment. It is not preferable.

  In the toner of the present invention, the content of the crystalline polyester resin is preferably in the range of 3 to 30% by mass, and more preferably in the range of 5 to 20% by mass. When the content of the crystalline resin is less than 3% by mass, the effect of improving the low-temperature fixability may not be obtained. When the content is more than 35% by mass, the hardness of the toner is lowered and the external additive is embedded. It may be easier and the life may be shortened. A part of the crystalline polyester resin is in an amorphous state, and therefore the cause is that the resin strength at room temperature is lower than that of the amorphous resin.

  The amorphous polyester resin can be obtained by using the same monomer as the crystalline polyester resin and using the same method. From the viewpoint of chargeability and fixability, bisphenol A dialcohol and The phthalic acid-based dicarboxylic acid is preferred. Specifically, bisphenol A ethylene oxide disallowed, bisphenol A propylene oxide disallowed, terephthalic acid, and isophthalic acid are mainly used. The amorphous polyester resin may have a crosslinked structure in the molecule. Monomers that form a crosslinked structure include trivalent or higher carboxylic acids such as benzenetricarboxylic acid naphthalenetricarboxylic acid, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, and anhydrides thereof. Acid monomers such as lower alkyl esters, and trivalent or higher alcohol monomers such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used individually by 1 type and may use 2 or more types together.

  The amorphous polyester resin preferably has a weight average molecular weight in the range of 5000 to 30000, more preferably in the range of 7000 to 20000, as measured by GPC. If the molecular weight is too small, the offset property may deteriorate. If the molecular weight is too large, the melt viscosity of the toner increases and the low-temperature fixability may deteriorate.

  The acid value of the amorphous polyester resin is preferably 2.0 to 25.0 mgKOH / g. More preferably, it exists in the range of 3.0-20.0 mgKOH / g, More preferably, it exists in the range of 4.0-15.0 mgKOH / g. If the acid value is lower than 2.0 mgKOH / g, the stability as a resin particle at the time of aggregation is poor, and if it exceeds 25.0 mgKOH / g, the hygroscopicity of the toner increases and the toner is susceptible to environmental influences. It is not preferable.

  The glass transition temperature of the amorphous polyester resin is preferably in the range of 45 ° C to 80 ° C. More preferably, it exists in the range of 50 to 75 degreeC, More preferably, it exists in the range of 55 to 65 degreeC. If the glass transition temperature is too high, the low-temperature fixability may be impaired. If the glass transition temperature is too low, the storage stability of the toner may deteriorate.

The magenta toner for electrophotography of the present invention includes at least a quinacridone pigment and a naphthol pigment having the above characteristics as a colorant.
The quinacridone pigment used in the present invention is represented by the following general formula (1). I. And CI Pigment Red 122, 202, and 209. Among these, C.I. from the viewpoint of manufacturability and chargeability. I. Pigment Red 122 is particularly preferred.

  In addition, as means for controlling the Ca content in the quinacridone pigment used in the present invention within the above-mentioned range, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, an attritor, etc., a high pressure opposed collision type dispersion It is possible to obtain a quinacridone pigment dispersion (colorant dispersion) using a known disperser such as a machine, and then adjust the pH of the dispersion to a range of 5 to 8.

The naphthol pigment used in the present invention is represented by the following general formula (2) (herein, R ′ is preferably a methoxy group (—OCH ₃ ) in the general formula (1)), specifically. Specifically, for example, C.I. I. Pigment Red 31, 146, 147, 150, 176, 184, 238, 269, and the like. Of these, naphthol pigments having a structure represented by the following formula (2) are particularly preferred from the viewpoints of manufacturability and chargeability. I. Pigment red 238, 269 and the like.

  The means for controlling the sum of the half widths in the X-ray diffraction pattern of the naphthol pigment used in the present invention with a Bragg angle of 0 to 35 ° within the above range is a rotary shear type homogenizer, ball mill, sand mill, atomizer. After obtaining a naphthol pigment dispersion (colorant dispersion) using a known disperser such as a lighter or other medium disperser or a high-pressure opposed collision disperser, the dispersion is cooled by a heat exchanger. What is necessary is just to perform the temperature gradient at the time of carrying out at the speed | rate of 100-150 degreeC / min.

In the present invention, when the binder resin in the toner particles contains the crystalline polyester resin and the amorphous polyester resin and further contains a release agent, the average primary particle size of the quinacridone pigment is Pq50, naphthol. When the average primary particle size of the pigment is Pn50, the fact that these satisfy the relationship of the following formula (1) is yellowing of transmitted light due to light scattering of the crystalline resin, in particular, a blue region which is a mixed color of cyan and magenta It is preferable for improving the yellowing of the.
20 nm <Pq50 <Pn50 <150 nm Formula (1)

  The reason for this is not clear, but is estimated as follows. That is, the naphthol pigment has a higher coloring power and a higher ability to hide the lower layer than the quinacridone pigment. If the hiding power is too high, the color reproduction of the secondary color is deteriorated. On the other hand, since the quinacridone pigment has a relatively weak hiding power, it is presumed that the deterioration of the color reproducibility of the secondary color is small even if the pigment particle size is reduced.

  The average primary particle size of the quinacridone pigment and naphthol pigment is measured as follows. The pigment is observed with a transmission electron microscope (TEM) at a magnification of 100,000 times, and among the observed photographs, one that can identify the primary particle diameter of the pigment is picked up. After fixing the tracing paper on the photograph so that it does not move and marking the outline of each pigment with a magic, remove the tracing paper, cut the marked piece and measure the mass. Separately, a circle having the same diameter as the length corresponding to 10 nm of the observed image is created and the mass is measured. Thereafter, the average particle diameter can be obtained by comparing the mass of 10 nm with the same operation up to the equivalent of 200 nm and the actual marking. Therefore, all are counted as the equivalent circle diameter of the projected image. Randomly extracted for 500 pigments.

  The primary particle sizes of the quinacridone pigment and naphthol pigment can be adjusted by a known method. For example, a solvent salt milling method, a dry milling method, and an acid pasting method as described from page 3 in JP-A-2003-89756, and an azo coupling method described in Japanese Patent No. 3055673 Etc. can be used.

The toner of the present invention preferably contains naphthol pigments and quinacridone pigments as colorants in the range of 4 to 20% by mass, and preferably in the range of 6 to 15% by mass. If it is less than 4% by mass, sufficient colorability cannot be obtained, and if it exceeds 20% by mass, the toner productivity may be affected.
Further, when the binder resin in the toner particles contains the crystalline polyester resin and the amorphous polyester resin and further contains a release agent, 80% by mass or more of the naphthol pigment is Pigment Red 269. It is preferable that 80% by mass or more of the quinacridone pigment is Pigment Red 122 in terms of color development.

  The naphthol pigment and quinacridone pigment as the colorant are preferably used in a mixture ratio in the range of 80:20 to 30:70, from the viewpoint of better image quality, more preferably 75. : The range of 25-40: 60, More preferably, it is the range of 70: 30-50: 50. If there is too much naphthol pigment, the hue may shift. On the other hand, if the amount is too small, there may be a problem such as a decrease in density due to insufficient coloring power.

  As the colorant, in addition to the naphthol pigment and quinacridone pigment, other colorants can be used in combination for adjusting the hue, for example, in the range of 20% by mass or less of the total colorant amount. Other colorants include bengara, cadmium red, red lead, mercury sulfide, watching red, permanent red 4R, risor red, brilliant carmine 3B, brilliant carmine 6B, pyrazolone red, rhodamine lake B, lake red C, rose bengal, Examples include eosin red and alizarin lake.

  The dispersion of the pigment in the toner is confirmed by observing the cross-sectional image (100,000 times) of the toner with a transmission electron microscope (TEM) and determining the average dispersion diameter (median diameter) of 500 colorants. Can do. In the present invention, the average dispersion diameter is preferably in the range of 20 to 150 nm.

The toner of the present invention may contain a release agent for the purpose of improving fixability and image storage stability. The average dispersion diameter of the release agent in the cross section of the toner by observation with a transmission electron microscope image is 150 to The area occupied by the release agent in the cross section of the toner is preferably in the range of 1500 nm to 10 to 35% of the entire cross sectional area.
The observation of the transmission electron microscope image is performed at a magnification of 100,000 times, and the average dispersion diameter is an average of the diameters of 500 release agents.

  When the dispersion diameter of the release agent is smaller than 150 nm, the function as a release agent is small and sufficient peelability may not be obtained. If it is larger than 1500 nm, OHP permeability may be impaired. Furthermore, if the area occupied by the release agent in the cross section of the toner determined from the transmission electron microscope image is less than 10% of the entire cross sectional area, the function as the release agent is small and sufficient releasability is obtained. It may not be possible. On the other hand, if it is larger than 35%, the dispersibility of the pigment in the toner deteriorates, and the color reproducibility may deteriorate.

The dispersion diameter is more preferably in the range of 180 to 300 nm. The area occupied by the release agent is more preferably in the range of 12 to 20%.
As a method of controlling the dispersion diameter of the release agent within the above range, the content of the release agent in the toner is in the range of 5 to 10%, and the fusion time in the toner production described later is 2 to 55 hours. This is achieved by setting a range of.

  Examples of the release agent used in the present invention include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene, silicones that exhibit a softening point by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide, and the like. Fatty acid amides such as, carnauba wax, rice wax, candelilla wax, plant wax such as tree wax, jojoba oil, animal wax such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, Examples thereof include mineral-based and petroleum-based waxes such as microcrystalline wax, microcrystalline wax, Fischer-Tropsch wax, and modified products thereof.

  In the present invention, it is preferable to use minerals such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, petroleum wax, and polyalkylene which is a modified product thereof, as the mold release agent. The viscosity η140 at 140 ° C. measured by an E-type viscometer is preferably in the range of 1.5 to 5.0 mPa · s, more preferably in the range of 2.0 to 4.5 mPa · s.

  When the viscosity η140 at 140 ° C. is less than 1.5 mPa · s, the powder fluidity of the toner deteriorates, or the release agent layer formed on the image after fixing becomes non-uniform, resulting in uneven peeling. In some cases, it may cause problems such as uneven image gloss. Also, when the viscosity η is higher than 5.0 mPa · s, the melt viscosity increases and the release property of the release agent decreases, so that between oil and an image fixing member such as a fixing roll during oilless fixing. In addition, there may be a case where the original merit of the mold release agent having a low melt viscosity is lost such that a mold release agent necessary for mold release cannot be supplied and a peeling failure occurs.

The viscosity η140 of the release agent at 140 ° C. is measured with an E-type viscometer. In the measurement, an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) equipped with an oil circulation type thermostatic bath was used. Here, a cone plate having a cone angle of 1.34 ° was used.
Specifically, the measurement is performed as follows. First, the temperature of the circulation device is set to 140 ° C., and an empty sample measurement cup, an empty reference cup, and a cone are set in the measurement device, and kept at a constant temperature while circulating oil. Next, when the temperature is stabilized, 1 g of the sample is put in the sample measuring cup, and the cone is allowed to stand still for 10 minutes. After stabilization, rotate the cone and measure. The rotational speed of the cone is 60 rpm. The measurement was performed three times, and the average value was defined as a viscosity η140 at 140 ° C.

Moreover, it is preferable that the main body maximum peak in the differential scanning calorimetry measured according to ASTM D3418-8 is in the range of 85 to 95 ° C, and in the range of 86 to 93 ° C. Is more preferable.
If the main maximum peak is less than 85 ° C., there may be a problem that an offset is likely to occur. When the temperature exceeds 95 ° C., the toner fixing temperature becomes high, so that the smoothness of the surface of the fixed image cannot be obtained, the glossiness is impaired, and the elution property of the release agent is lowered, so that the oilless releasability is reduced. In some cases, a problem such as a decrease in image quality may occur.

For the measurement of the main maximum peak, for example, DSC-7 manufactured by Perkin Elmer is used. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.
The glass transition point and melting point of the binder resin described above were also measured by the same method as described above.

Further, the content in the toner determined from the height of the endothermic peak at the maximum endothermic value in the differential thermal analysis of the release agent is preferably in the range of 5 to 10% by mass. More preferably, it is the range of 6.5-8.5 mass%.
If the amount of the release agent is less than 5% by mass, although it is advantageous for the drying treatment of the wet toner described later, a sufficient elution amount for peeling at the time of oilless fixing cannot be obtained, the peelability is impaired, and the surface is roughened. As a result, image glossiness may be reduced. On the other hand, if it exceeds 10% by mass, the transfer of the release agent to the surface of the wet toner is facilitated during drying, and not only the powder fluidity of the toner after drying is lowered, but also a discharge roll for discharging a fixed image. Such a contact mark may occur, and the image quality may be impaired.

Next, a preferred method for producing the toner of the present invention will be described.
The toner of the present invention is a wet process including an aggregating step of forming aggregated particles in a dispersion in which at least resin particles and colorant particles are dispersed, and a fusing step of fusing the aggregated particles by heating the aggregated particles. It is possible to easily obtain a small particle diameter toner having a sharp particle size distribution and to form a high-quality full-color image by obtaining it by a manufacturing method (hereinafter sometimes referred to as “aggregation and fusion method”). This is preferable from the viewpoint of obtaining a color toner.

  Further, between the agglomeration step and the fusion step, a step of adding a particle dispersion liquid in which particles are dispersed in an agglomerated particle dispersion liquid and adhering fine particles to the agglomerated particles to form adhering particles (adhesion) Step) may be provided. In this adhesion step, the particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the aggregation step, and the fine particles are adhered to the aggregated particles to form the adhered particles. In this specification, it may be referred to as “additional particles”.

  As the additional particles, in addition to the resin particles, release agent fine particles, colorant fine particles and the like may be used singly or in combination. There is no restriction | limiting in particular as a method of adding and mixing a particle dispersion liquid, For example, you may carry out gradually continuously and may carry out in steps divided | segmented into multiple times. Thus, by adding and mixing particles (additional particles), generation of fine particles can be suppressed, and the particle size distribution of the obtained toner particles can be sharpened.

  Also, by providing an adhesion process, a pseudo core / shell structure can be formed, and the toner surface exposure of internal additives such as colorants and mold release agents can be reduced, resulting in improved chargeability and life. In addition, it is possible to maintain the particle size distribution during fusion in the fusion step, to suppress fluctuations thereof, and to stabilize the surfactant, base, acid, etc. to enhance stability during fusion. It is advantageous in that the addition of the agent is unnecessary or the amount of addition can be suppressed to the minimum, and the cost can be reduced and the quality can be improved. Therefore, when using a release agent, it is preferable to add additional particles mainly composed of resin particles. If this method is used, the toner shape can be easily controlled by adjusting the temperature, the number of stirring, the pH and the like in the fusing step.

  When the crystalline polyester resin is used in the aggregation and fusion method, an emulsification step of emulsifying the crystalline polyester resin to form emulsified particles (droplets) and an aggregate of the emulsified particles (droplets) are formed. And a coalescing step of fusing and aggregating the aggregates. Alternatively, instead of the aggregation process and the coalescence process, the aggregation process and the coalescence process may be performed at the same time, and the aggregation process and the coalescence process may be performed from the viewpoint of particle size controllability and shape controllability. It is preferable to use a separate process. The resin particles correspond to emulsified particles.

In the aggregation step, the obtained emulsified particles may be aggregated by heating to a temperature not higher than the melting point of the polyester resin and not higher than the glass transition temperature of the amorphous polyester resin to form an aggregate. preferable. When the temperature for forming the aggregate is too high, coarse powder and fine powder are generated, and the particle size distribution is deteriorated. Formation of the aggregate of the emulsified particles is performed by acidifying the pH of the emulsion under stirring. As said pH, 2.0-5.0 are preferable and 2.5-4.5 are more preferable. At this time, a dispersant described later may be used in combination according to the stability of the emulsified particles.
Moreover, it is preferable that the resin particle added in the said adhesion process is an amorphous polyester resin emulsified particle. By providing this step, a pseudo core / shell structure can be formed.

  Examples of the resin particles and the additional resin particles used in the aggregation process include particles such as a resin formed from the thermoplastic polymer serving as the binder resin. Among these resins, vinyl resins are particularly preferable. The vinyl resin is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like.

  The method for preparing the dispersion of resin particles is not particularly limited, and a method appropriately selected according to the purpose can be adopted. For example, it can be prepared as follows. When the resin in the resin particles is a homopolymer or copolymer (vinyl resin) of vinyl monomers such as esters having the vinyl group, vinyl nitriles, vinyl ethers, vinyl ketones, etc. Ionizes resin particles made of a homopolymer or copolymer (vinyl resin) of a vinyl monomer by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in an ionic surfactant. It is possible to prepare a dispersion obtained by dispersing in a functional surfactant. In addition, when the resin in the resin particles is a resin other than a homopolymer or copolymer of a vinyl monomer, the resin can be dissolved in an oily solvent having a relatively low solubility in water. The resin is dissolved in the oily solvent, and the dissolved material is added to water together with an ionic surfactant and a polymer electrolyte, and the particles are dispersed using a disperser such as a homogenizer, and then heated or decompressed. Can be prepared by evaporating the oily solvent.

  When the resin particles dispersed in the resin particle dispersion are composite particles containing components other than resin particles, the dispersion in which these composite particles are dispersed can be prepared, for example, as follows. it can. For example, after each component of the composite particles is dissolved and dispersed in a solvent, it is dispersed in water with an appropriate dispersant as described above, and the solvent is removed by heating or decompression, emulsion polymerization, It can be prepared by a method of immobilizing by performing mechanical shearing or electroadsorption on the latex surface prepared by seed polymerization. Moreover, when manufacturing resin particles, you may use the composite resin particle manufactured by adding a coloring agent and a mold release agent.

The particle diameter of the resin particles is 1 μm or less, preferably 50 to 400 nm, more preferably 70 to ₃₅₀ nm in _terms of the number average particle diameter D _50n . If the number average particle size of the resin particles is large, the particle size distribution of the finally obtained toner may be broadened, or free particles may be generated, leading to a decrease in performance and reliability. On the other hand, if it is too small, the solution viscosity at the time of toner production becomes high, and the particle size distribution of the finally obtained toner may become wide. When the average particle diameter of the resin particles is within the above range, the above disadvantages are eliminated, the uneven distribution between the toners is reduced, the dispersion in the toner is good, and the variation in performance and reliability is advantageous. is there.

  Here, the number average particle size of the resin particles can be measured, for example, with a laser diffraction particle size distribution measuring device (manufactured by Horiba: LA-700, manufactured by Nikkiso Co., Ltd .: Microtrac UPA9340).

In the production of the toner of the present invention by the aggregation and fusion method, the average particle diameter of the colorant particles in the colorant particle dispersion is desirably 0.5 μm or less in _terms of the number average particle diameter D _50n , and more desirably is 0. It is 05-0.5 micrometer, More preferably, it is 0.1-0.3 micrometer. When the average particle size of the colorant particles exceeds 0.5 μm, the particle size distribution of the finally obtained toner for developing an electrostatic image is broadened, or free particles are generated, which leads to deterioration in performance and reliability. There is. When the average particle diameter of the colorant particles is smaller than 0.05 μm, not only the colorability in the toner is lowered, but also the shape controllability that is one of the characteristics of the emulsion aggregation method is impaired, and the shape close to a true sphere. Toner may not be obtained.

  Further, the number% of particles of 0.5 μm or more is preferably less than 10%, substantially preferably 0%. The presence of such coarse particles impairs the stability of the agglomeration process, and widens the particle size distribution as well as liberation of coarse colored particles. Further, the number% of particles of 0.03 μm or less is preferably 5% or less. The presence of such fine particles may impair the shape controllability in the fusion process, and a so-called smooth one having a shape factor SF1 of 135 or less may not be obtained. On the other hand, when the average particle diameter, coarse particles, and fine particles of the colorant particles are within the above ranges, there is no such defect, and uneven distribution between the toners is reduced, and dispersion in the toners is improved. Further, it is advantageous that the variation in reliability is reduced.

  In the present invention, the addition amount of the colorant is preferably in the range of 3 to 15% by mass with respect to the toner particles. Here, the number average particle diameter of the colorant particles can be measured with Microtrac (manufactured by Nikkiso Co., Ltd .: Microtrac UPA9340).

  Inorganic or organic particles can be added to the toner of the present invention. These particles can improve the dispersibility of internal additives such as colorants and release agents. Further, the storage elastic modulus of the toner increases due to the reinforcing effect of the particles, and the offset resistance and the peelability from the fixing device may be improved. As the inorganic particles, silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate and the like can be used alone or in combination. Among these, silica is preferably used from the viewpoint of OHP transparency. The particles can be added directly at the time of toner production, but it is preferable to use particles that have been previously dispersed in a water-soluble medium such as water in order to improve dispersibility. In the dispersion, the dispersibility can be improved by using an ionic surfactant, a polymer acid, a polymer base, or the like.

  Known materials such as other charge control agents may be added to the toner of the present invention. The average particle size of the material added at that time is required to be 1 μm or less, or preferably 0.01 to 1 μm. When the average particle size exceeds 1 μm, the particle size distribution of the finally obtained electrostatic image developing toner is broadened or free particles are generated, which tends to deteriorate performance and reliability. On the other hand, when the average particle size is within the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toners is improved, and the variation in performance and reliability is advantageous. The average particle diameter can be measured using, for example, a microtrack.

  In the toner of the present invention, examples of the dispersion medium in the dispersion in which the resin particle dispersion, the colorant dispersion, and other components (particles) are dispersed include an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion exchange water, alcohols, and the like. These may be used individually by 1 type and may use 2 or more types together.

  In the toner of the present invention, the means for preparing various dispersions is not particularly limited, and examples thereof include known dispersion devices such as a rotary shear type homogenizer and a ball mill having a media, a sand mill, and a dyno mill.

  In the toner of the present invention, it is preferable to add and mix a surfactant as a dispersant in the aqueous medium. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol Suitable examples include nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the anionic surfactant include fatty acid soaps such as potassium laurate, sodium oleate and sodium castor oil; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate and nonyl phenyl ether sulfate; lauryl sulfonate, Sodium alkylnaphthalene sulfonate such as dodecyl sulfonate, dodecyl benzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate, naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate, etc. Sulfonates: lauryl phosphate, isopropyl phosphate, noni Phosphoric acid esters such as phenyl ether phosphates; dialkyl sodium sulfosuccinates such as sodium dioctylsulfosuccinate, sodium lauryl sulfosuccinate 2, polyoxyethylene sulfo sulfosuccinate salts such as succinic acid lauryl disodium and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium chloride , Distearyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dihydroxyethyl methyl ammonium chloride, oleyl bis polyoxyethylene methyl ammonium chloride, lauroyl aminopropyl dimethyl ethyl ammonium etosulphate, lauroyl aminopropyl dimethyl hydroxyethyl ammonium perchlorate, alkylbenzene dimethyl ammonium Chloride, alkyl trime Quaternary ammonium salts such as Le ammonium chloride.

  Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate Etc.

Using the materials as described above, in the aggregation step, at least a resin particle dispersion and a colorant dispersion, and if necessary, a dispersion prepared by adding and mixing other components such as a release agent dispersion Is heated at room temperature to a glass transition temperature of the resin plus about 5 ° C. with stirring to agglomerate the resin particles and the colorant to form aggregate particles. The volume average particle diameter of the aggregate particles is preferably in the range of 2 to 9 μm. Resin particles (additional particles) may be added to the aggregate particles formed in this way to form a coating layer on the surface of the aggregate particles (attachment step).

  Next, in the fusing step, for example, heat treatment is performed at a temperature equal to or higher than the glass transition point of the resin, generally 70 to 120 ° C., and the aggregate particles are fused to obtain a toner particle-containing liquid (toner particle dispersion). Next, the obtained toner particle-containing liquid is treated by centrifugal separation or suction filtration to separate the toner particles, and washed 1 to 3 times with ion exchange water. At that time, the cleaning effect can be further enhanced by adjusting the pH. Thereafter, the toner particles are separated by filtration, washed 1 to 3 times with ion exchange water, and dried to obtain toner particles for use in the toner of the present invention.

  Inorganic particles and organic particles can be added to the toner particles as fluidity aids, cleaning aids, abrasives, and the like. Examples of inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, cerium oxide, and all the particles that are usually used as external additives on the toner surface. Examples of the body include all particles usually used as an external additive on the toner surface, such as vinyl resin, polyester resin, silicone resin, and fluorine resin. Further, a lubricant can be added. Examples of the lubricant include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate. Among inorganic particles, it is preferable to add silica hydrophobized as an essential component.

In order to obtain a toner of another color similar to that of the toner of the present invention for forming a full color image, for example, the following colorant can be used.
Examples of the black pigment include carbon black, copper oxide, manganese dioxide, arinin black, activated carbon, nonmagnetic ferrite, and magnetite, and carbon black is particularly preferably used. Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, hansa yellow, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, sren yellow, quinoline yellow, permanent yellow NCG, and the like. In particular, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 185 or the like is preferably used.

  As cyan pigments, bitumen, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, chalcoil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare Rate, and the like. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is preferably used. Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange PK, and indanthrene brilliant orange GK. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake. Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.

  Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenyl Various dyes such as methane, diphenylmethane, thiazine, thiazole, and xanthene are also used. These colorants are used alone or in combination.

  As these colorants, for example, a dispersion of colorant particles can be prepared using a media type dispersing machine such as a rotary shearing homogenizer, a ball mill, a sand mill, or an attritor, or a high-pressure opposed collision type dispersing machine. The colorant can also be dispersed in an aqueous system by a homogenizer using a polar surfactant. At this time, by setting the average dispersion diameter of the colorant to 100 to 330 nm, light transmittance and color developability are improved.

  These colorants are selected from the viewpoints of hue angle, brightness, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The colorant can be added in the range of 4 to 15% by mass with respect to the total mass of the toner constituting solids. When using a magnetic substance as a black colorant, it can be added in the range of 12 to 240% by mass, unlike other colorants. Specifically, a substance that is magnetized in a magnetic field is used, but a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite is used. When the toner is obtained in the aqueous phase in the present invention, it is necessary to pay attention to the aqueous phase transfer property of the magnetic material. Preferably, the surface of the magnetic material is preferably modified in advance and subjected to, for example, a hydrophobic treatment. preferable.

  The toner of the present invention preferably has a shape factor SF1 of 110 to 140, more preferably 113 to 137, and still more preferably 115 to 135. When the shape factor SF1 is less than 110, the adhesion between toner particles becomes weak, and scattering may easily occur during transfer. On the other hand, if SF1 exceeds 140, the transferability may be lowered, or the density of the toner developed image may be lowered.

Here, the shape factor SF1 is obtained by the following equation (3).
SF1 = (ML ² / A) × (π / 4) × 100 (3)
In the above formula, ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles. SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and can be calculated as follows. By taking the image of the optical microscope of the toner dispersed on the slide glass into a Luzex image analyzer through a video camera, obtaining the maximum length and projected area of 100 or more toners, calculating by the above formula, and calculating the average value can get. That is, the shape factor SF1 in the present invention is calculated by analyzing an image observed with an optical microscope with a Luzex image analyzer.
As a method of controlling the shape factor SF1 within the range of 110 to 140, it is preferable from the viewpoint of manufacturing stability that the toner is manufactured by the wet manufacturing method (aggregation fusion method).

The toner of the present invention preferably has a volume average particle diameter D _50V in the range of 2 to 9 μm, more preferably 3 to 8 μm, and further preferably 4 to 7 μm. By setting the volume average particle diameter D _50V in the above range, not only the transferability can be improved as described above, but also the chargeability can be improved.

The toner of the present invention preferably has a volume average particle size distribution index (GSDv) of 1.25 or less. When it is 1.25 or less, the sharpness and resolution of the image are further improved.
Here, the particle size distribution of the toner is divided into 16 channels from a particle size range (number of divisions: 1.26 to 50.8 μm) based on the particle size distribution measured with a Coulter Counter TAII (manufactured by Beckman-Coulter). The log scale is divided into 0.1 intervals, specifically, channel 1 is 1.26 μm or more and less than 1.59, channel 2 is 1.59 μm or more and less than 2.00 μm, and channel 3 is 2.00 μm or more. It was set to be less than 2.52 μm, and the log values of the numerical values on the left side were divided so as to be (log 1.26 =) 0.1, (log 1.59 =) 0.2, 0.3,. ), The cumulative distribution is drawn from the smaller diameter side, and the particle diameter of 16% cumulative is the volume D _16v , the number D _16P , the particle diameter of 50% cumulative is the volume D _50v , the number D _50P , Cumulative 84% Diameter volume D _84v, defined as the number D _84P, using these values, the volume average particle size distribution index (GSDv) is 84 cumulative volume percent of the ratio of the square root for the 16 cumulative volume% in the volume particle size distribution, i.e. (D _84v / D _16V ) ^1/2 .

  In the toner of the present invention, the absolute value of the charge amount is preferably in the range of 10 to 50 μC / g, and more preferably in the range of 15 to 35 μC / g. If the charge amount is less than 10 μC / g, background stains tend to occur, and if it exceeds 50 μC / g, the image density tends to decrease. The ratio of the charge amount under high humidity of 30 ° C. and 80 RH% and low humidity of 10 ° C. and 20 RH% is preferably in the range of 0.5 to 1.5, and in the range of 0.7 to 1.2. More preferred. When this ratio is within the range, a clear image can be obtained without being affected by the environment. In particular, the toner of the present invention is preferably negatively charged.

  The toner of the present invention has a molecular weight distribution represented by a ratio (Mw / Mn) of a weight average molecular weight (Mw) and a number average molecular weight (Mn) measured by gel permeation chromatography, from 1.5 to 30. Is preferably in the range of 2.5 to 20, more preferably in the range of 2.5 to 20. If the molecular weight distribution represented by the ratio (Mw / Mn) exceeds 30, the gloss (glossiness) of the fixed image may be lowered, so that the light transmittance and colorability are not sufficient, especially on the film. In addition, when the electrostatic image developing toner is developed or fixed, an image projected by light transmission may become a blurred and dark image or a projection image that does not transmit and does not develop color. On the other hand, if the viscosity is less than 1.5, the viscosity of the toner at the time of high-temperature fixing is remarkably reduced, and an offset phenomenon is likely to occur. On the other hand, when the molecular weight distribution represented by the ratio (Mw / Mn) is within the above numerical range, the light transmittance and colorability are sufficient, and the viscosity of the toner for developing an electrostatic charge image during high-temperature fixing is reduced. And the occurrence of the offset phenomenon can be effectively suppressed.

Here, the molecular weight distribution is a value obtained under the following conditions. Tosoh Corporation HLC-8120GPC, SC-8020 apparatus was used, TSK gel, SuperHM-H (6.0 mm ID × 15 cm × 2) was used as a column, and THF (tetrahydrofuran) was used as an eluent. As experimental conditions, the sample concentration was 0.5%, and the flow rate was 0.6 ml / min. Sample injection volume 10 μl, measurement temperature 40 ° C., calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: A-500, F-1, F-10, F-80, F-380, A-2500, F -4, F-40, F-128, and F-700. The data collection interval in sample analysis was 300 ms.
The weight average molecular weight of the binder resin used in the present invention can also be measured in the same manner as described above.

  The electrostatic latent image developer used in the present invention is not particularly limited except that it contains the electrophotographic magenta toner of the present invention, and can have an appropriate component composition depending on the purpose. For example, the electrophotographic magenta toner of the present invention may be used alone to prepare a one-component electrostatic image developer, or as a two-component electrostatic image developer in combination with a carrier. It may be prepared.

  The carrier is not particularly limited, and a carrier known per se such as an iron powder carrier or a ferrite carrier can be used. For example, JP-A-62-39879, JP-A-56-11461, etc. Known carriers such as the resin-coated carriers described can be used. The mixing ratio of the electrostatic image developing toner of the present invention and the carrier in the electrostatic image developer is not particularly limited and can be appropriately selected according to the purpose.

Next, the full color image forming method of the present invention will be described.
The full-color image forming method of the present invention includes a step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image with an electrostatic latent image developer containing toner to form a toner image. A full-color image forming method comprising: a step of transferring a toner image onto a transfer target; and a step of thermally fixing the toner image on a transfer target. The electrophotographic magenta toner of the invention is used.

  In the full-color image forming method of the present invention, each of the steps is a general step per se, and is described in, for example, JP-A-56-40868, JP-A-49-91231, etc. The present invention can be suitably applied to the specification. The image forming method of the present invention can be carried out using an image forming apparatus such as a copier or a facsimile machine known per se. Further, the step of transferring the toner image onto the transfer medium may be performed by a method in which the toner image on the electrostatic latent image carrier is transferred directly to the recording medium, or may be transferred via an intermediate transfer medium. You may carry out by the system which transfers to a transfer body. In this case, when the toner image is directly transferred from the photosensitive member to a sheet or the like, the sheet (recorded body) is the transferred body. However, when the intermediate transfer body is used, the intermediate transfer body is also included in the transferred body. It is what

  The full-color image forming method of the present invention can also be applied to an electrophotographic system including a toner recycling process. The toner recycling process is a process of transferring the toner collected in the cleaning process to the developer layer. The present invention can also be applied to a recycling system in which the cleaning process is omitted and toner is collected simultaneously with development.

  In the full-color image forming method of the present invention, the step of thermally fixing the toner image can be performed using a known contact-type heat fixing device. Specifically, for example, a rubber elastic layer is provided on the core metal. And a fixing member comprising a heating roller having a fixing member surface layer as required, and a pressure roller having a rubber elastic layer on the core and optionally having a fixing member surface layer. As a heat roller fixing device or a fixing member, a fixing device in which such a combination of a roller and a roller is replaced with a combination of a roller and a belt or a combination of a belt and a belt can be used. The fixing device may be provided with a release agent coating means such as silicone oil as necessary.

  For the base material (core) of the fixing member, a material having excellent heat resistance, strong strength against deformation, and good thermal conductivity is selected. In the case of a roll type fixing member, for example, aluminum, iron, copper, etc. are selected. In the case of a belt-type fixing member, a material having high heat resistance and durability such as a polyimide film, a polyamideimide film, and a stainless steel belt is selected. As the rubber elastic layer, heat-resistant rubber such as silicone rubber or fluorine rubber is used, and the rubber hardness is preferably in the range of 10 to 80 degrees as Asker C hardness. If the hardness is too low, the durability is inferior. If the hardness is too high, the roll may be insufficiently deformed and the fixability may be impaired. The thickness is preferably 0.05 mm to 5 mm. If the thickness is too thin, deformation may be insufficient and fixability may be impaired. If it is too thick, heating may take time, and practicality may be inferior.

  As the fixing member surface layer, silicone rubber, fluororubber, fluorolatex, and fluororesin are used, and among them, by using fluororesin, a highly reliable fixing performance can be obtained over a long period of time. As the fluororesin used on the surface of the fixing member, a soft fluororesin containing Teflon (registered trademark) (R) such as PFA (perfluoroalkoxyethyl ether copolymer), vinylidene fluoride, or the like can be used. Since fluororesin does not show a drop in releasability due to adhesion or deposition of toner stains compared to silicone rubber or fluororubber, if the releasability on the toner side is sufficient, the length of the fixing member Life expectancy can be improved. The fixing member surface layer preferably has a thickness of 1.0 μm to 80 μm. If the thickness is too thin, the durability is inferior, and if it is too thick, the deformation is insufficient and the fixability may be impaired. The fixing member may contain various additives depending on the purpose. For example, the fixing member contains carbon black, metal oxide, ceramic particles such as SiC, etc. for the purpose of improving wear resistance and controlling resistance. May be.

  In the full-color image forming method of the present invention, the fixing device includes a fixing member that includes a pair of rotating members that are in contact with the front and back of the recording medium, and at least one of the pair of rotating members is a belt member. It is particularly preferable to use a combination of a roller and a belt or a fixing device that combines a belt and a belt as the fixing member. By thermally fixing the toner image using the magenta toner for electrophotography of the present invention with this fixing device, it is possible to further suppress the toner penetration phenomenon and to form a higher quality image.

  The reason for this is not clear, but if a fixing device having a belt member as a fixing member is used, the time for heating the toner can be increased, so the temperature for heating the toner is lower than that of the roller-roller system. As a result, the toner can be fixed with a high viscosity, so that it is presumed that the occurrence of the permeation phenomenon can be suppressed.

  Specific examples of a fixing device having a belt member as a fixing member include, for example, a heating roller having a surface layer made of an elastic layer and a fluororesin layer on a core material as described above, and a belt made of a polyimide film or the like. In addition, a fixing device having a belt-type pressure system including a pressure member that presses the heating roller from the inside of the belt can be used. In the belt-type pressure system, it is preferable that the belt is heated at a temperature lower than that of the heating roller or not heated.

Although it is not necessary to apply release oil to the fixing member, a release agent is preferably applied from the viewpoint of durability and reliability.
The amount of the release oil applied to the fixing member is preferably 1.6 × 10 ^{−6 to} 8.0 × 10 ⁻⁴ mg / cm ² . It is preferable that the amount of the release oil applied is small. However, if the supply amount of the release oil is set to 0 mg / cm ² , the fixing member and the recording medium such as paper come into contact with each other during the fixing process. Since the wear amount increases and the durability of the fixing member may decrease, it is practically preferable that a small amount of release oil is supplied to the fixing member. On the other hand, if the supply amount of the release oil exceeds 8.0 × 10 ⁻⁴ mg / cm ² (0.5 mg per A4 sheet), the release oil adhered to the image surface after fixing. In particular, the image quality deteriorates, and particularly when transmitted light such as OHP is used, the image may appear remarkably.

  The supply amount of the release oil is measured as follows. In other words, when a plain paper (typically, a copy paper manufactured by Fuji Xerox Co., Ltd., trade name J paper) used in a general copying machine is passed through a fixing member supplied with release oil on the surface, the paper is released on the plain paper. Mold oil adheres. The release oil on the plain paper is extracted using a Soxhlet extractor. Hexane is used as the solvent. By quantifying the release oil contained in the hexane with an atomic absorption spectrometer, the amount of the release oil adhering to the plain paper is quantified. This amount is defined as the amount of release oil supplied to the fixing member.

  Although there is no restriction | limiting in particular as said release oil, Liquid release oils, such as heat-resistant oil, for example, modified oils, such as a dimethyl silicone oil, a fluorine oil, a fluoro silicone oil, and an amino modified silicone oil, are mentioned. The use of fluorine oil or fluorosilicone oil as the release oil is not practical in terms of cost since the supply amount of the release oil cannot be reduced in the case of the conventional image forming method. In the case of the full color image forming method of the invention, since the supply amount of the release oil can be drastically reduced, there is no practical problem in terms of cost. The method for supplying the release oil to the surface of the heat roller in the thermocompression bonding apparatus is not particularly limited. For example, a pad method, a web method, a roller method or a non-contact shower method impregnated with a liquid release oil. (Spray method). Among these, the web method and the roller method are preferable. These methods are advantageous in that the release oil can be supplied uniformly and it is easy to control the supply amount. In order to supply the release oil uniformly to the entire fixing member by a shower method, it is necessary to use a separate blade or the like.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. In the following, unless otherwise specified, “part” and “%” mean “% by mass” and “% by mass”, respectively.

<Resin synthesis>
(Crystalline polyester resin (1))
In a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube, 4.9 mol of 1,8-octanedicarboxylic acid, 0.1 mol of sodium dimethyl 5-sulfoisophthalate, 1,6-hexanediol 4 .8 mol and 0.22 mol of ethylene glycol were added, and the inside of the container was put into an inert atmosphere with nitrogen gas, 0.04 mol of dibutyltin oxide was added, and the reaction was stirred at about 180 ° C. for about 5 hours under a nitrogen gas stream. Let

  Thereafter, 0.02 mol of titanium tetrabutoxide was added, and an additional reaction was performed for 4 hours under a reduced pressure of a temperature of 230 ° C. and an internal pressure of the reaction vessel of 10.0 mmHg to obtain a crystalline polyester resin (1). The melting point measured using a differential scanning calorimeter (DSC) was 65 ° C., the molecular weight was measured by gel permeation chromatography (GPC) (polystyrene conversion), the weight average molecular weight (Mw) was 16000, and the number average molecular weight (Mn) was 7300. The acid value measured using an acetone-toluene mixed solution according to JIS-K0070 was 8 KOH mg / g.

(Amorphous polyester resin (1))
In a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, 1.5 mol of bisphenol A ethylene oxide 2 mol adduct, 1.8 mol of bisphenol A trimethylene oxide 2 mol adduct, After adding 1.1 mol of methanol, 0.62 mol of ethylene glycol, 4.0 mol of terephthalic acid, and 1.0 mol of isophthalic acid, the inside of the reaction vessel was replaced with dry nitrogen gas, and then dibutyltin oxide was added in an amount of 0.8. 04 mol was added and stirred and reacted at about 195 ° C. for about 6 hours under a nitrogen gas stream.

  The temperature was further raised to about 240 ° C., and the reaction was stirred for about 6.0 hours. Then, the pressure in the reaction vessel was reduced to 10.0 mmHg, and the reaction was carried out for about 0.5 hours under reduced pressure. A linear polyester resin (1) was obtained. DSC method Tg is 56 ° C, styrene conversion GPC method Mw is 11300, Mn is 4400, Mw / Mn is 2.6, acid value measured using acetone-toluene mixed solution according to JIS-K0070 is 12KOHmg / g there were.

<Preparation and preparation of each colorant>
(Quinacridone pigment A)
Dimethylquinacridone (Pigment Red 122) manufactured by Dainichi Seika Co., Ltd. was used as it was. The average primary particle size of this pigment was 110 nm.

(Quinacridone pigment B)
100 parts of dimethylquinacridone (Pigment Red 122) manufactured by Dainichi Seika Co., Ltd., 500 parts of sodium sulfate, and 150 parts of diethylene glycol were charged into a pressure type kneader and pre-kneaded until a uniform wet product was formed. Next, the internal pressure was set to 6 kg / cm ² , and the internal temperature was maintained at 35 ° C. to 45 ° C., and pulverized for 5 hours. The obtained pulverized product was put into a 2% sulfuric acid aqueous solution heated to 80 ° C., treated for 30 minutes, filtered, washed with water, and vacuum dried in an oven at 40 ° C. to obtain quinacridone pigment B. The average primary particle size of this pigment was 30 nm.

(Naphthol pigment A)
50 parts of 3-amino-4-methoxybenzanilide was dispersed in 1000 parts of water, ice was added to set the temperature to 0 to 5 ° C., and 60 parts of 35% HCl aqueous solution was added and stirred for 20 minutes. Thereafter, 50 parts of 30% sodium nitrite aqueous solution was added and stirred for 60 minutes, and then 2 parts of sulfamic acid was added to eliminate nitrous acid. Further, 50 parts of sodium acetate and 75 parts of 90% acetic acid were added to obtain a diazonium salt solution.

  Separately, 68 parts of N- (5-chloro-2-methoxyphenyl) -3-hydroxy-2-naphthalenecarboxamide was dissolved at a temperature of 80 ° C. or less together with 1000 parts of water and 25 parts of caustic soda to obtain benzenesulfonic acid. 3 parts of sodium (mineralite 100) (against pigment, 2.49%) was added to obtain a coupler solution.

  This solution was added to the diazonium salt solution under a temperature condition of 10 ° C. or lower, a coupling reaction was performed, and a heat treatment at 90 ° C. was performed. Next, after filtration and washing with water, drying at 100 ° C. and pulverization were performed to obtain naphthol pigment A (CI Pigment Red 238). The average primary particle size of this pigment was 70 nm.

(Naphthol pigment B)
Naphthol pigment B (CI Pigment Red 238) was obtained in the same manner as in the preparation of naphthol pigment A, except that the amount of Minerite 100 added was 2.2 parts. The average primary particle size of this pigment was 140 nm.

(Naphthol pigment C)
A naphthol pigment (CI Pigment Red 185) manufactured by Clariant Japan was used as it was. The average primary particle size of this pigment was 160 nm.

<Preparation of each dispersion>
(Resin particle dispersion)
-Resin particle dispersion (1)-
-Styrene (Wako Pure Chemical Industries): 325 parts-n-butyl acrylate (Wako Pure Chemical Industries): 100 parts-Acrylic acid (Rhodia Nikka Co., Ltd.): 13 parts-1,10-decanediol diacrylate (new) Nakamura Chemical Co., Ltd.): 1.5 parts ・ Dodecanethiol (Wako Pure Chemical Industries, Ltd.): 3.0 parts

  The above components are mixed in advance and dissolved to prepare a solution. A surfactant solution prepared by dissolving 9 parts of an anionic surfactant (Dowfax A211 manufactured by Dow Chemical Co., Ltd.) in 580 parts of ion-exchanged water is added to a flask. Then, 400 parts of the above solution was charged, dispersed and emulsified, and slowly stirred and mixed for 10 minutes, and then 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate had been dissolved was added.

Next, after the inside of the flask is sufficiently replaced with nitrogen, the flask is heated with an oil bath while stirring the flask until it reaches 75 ° C., and emulsion polymerization is continued for 5 hours to obtain a resin particle dispersion (1). It was.
When the resin particles were separated from the resin particle dispersion (1) and examined for physical properties, the number average particle diameter was 195 nm, the solid content in the dispersion was 42%, the glass transition point was 51.5 ° C., and the weight average molecular weight Mw. Was 32,000.

-Resin particle dispersion (2)-
The amorphous polyester resin (1) was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Specifically, ion-exchanged water 79%, anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) is 1% (as an active ingredient), and the concentration of the amorphous polyester resin (1) is 20%. The composition was adjusted to pH 8.5 with ammonia, the rotor was rotated at 60 Hz, the pressure was 5 kg / cm ² , and heated by a heat exchanger at 140 ° C. A resin fine particle dispersion (2) having a diameter of 290 nm was obtained.

-Resin particle dispersion (3)-
200 parts of the crystalline polyester resin (1) was put in 800 parts of distilled water, heated to 85 ° C., adjusted to pH 9.0 with ammonia, an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 0.4 parts (as an active ingredient) was added and dispersed at 8000 rpm for 7 minutes with a homogenizer (Ultra Tarax T50, manufactured by IKA Japan Co., Ltd.) while heating to 85 ° C. to obtain a resin particle dispersion (3) Got. The number average particle diameter of the resin particles was 260 nm.

-Additional particle dispersion-
-Resin particle dispersion (2) (amorphous polyester resin concentration: 20%) 150 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount 60%) 1.5 parts ( 0.9 parts as an active ingredient)

  After mixing the above components, a 1.0% aqueous nitric acid solution was added to adjust the pH to 4.0 to prepare additional particles (1).

(Colorant dispersion)
Quinacridone-based colorant dispersions (1) to (6) and naphthol-based colorant dispersions (7) to (13) were prepared as follows.
-Colorant dispersion (1)-
20 parts of quinacridone pigment A (Daiichi Seika Kogyo Co., Ltd., CI Pigment Red 122) 2 parts of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 4 parts of rosin calcium ion exchange 78 parts of water

  Using a homogenizer (Ultra Turrax T50, manufactured by IKA), the above components were mixed with water at 3000 rpm for 2 minutes, further dispersed at 5000 rpm for 10 minutes, and then stirred for one day with a normal stirrer to remove. After foaming, a magenta pigment dispersion was obtained by dispersing for about 1 hour at a pressure of 240 MPa using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). Further, the pH of the dispersion was adjusted to 6.5.

The dispersion was dried and the Ca content in the magenta pigment was measured by fluorescent X-ray analysis. The Ca intensity was 98 kcps. Thereafter, ion exchange water was added to adjust the solid content concentration of the dispersion to 15% to obtain a colorant dispersion (1). The number average particle diameter D _50n of the pigment in the dispersion was 130 nm.

-Colorant dispersions (2) to (5)-
Each dispersion was obtained in the same manner as in the preparation of the colorant dispersion (1) except that the pH adjustment values after dispersion were as shown in Table 1. Each of them was dried in the same manner, and the Ca strength in the pigment was measured. Thereafter, each of the colorant dispersions (2) to (5) was similarly prepared. The respective Ca strengths are also shown in Table 1.

-Colorant dispersion (6)-
-20 parts of quinacridone pigment B (CI Pigment Red 122)-2.4 parts of anionic surfactant (Daigen Kogyo Seiyaku Co., Ltd., Neogen SC) (12% of the colorant as an active ingredient)
・ Rosin calcium 4 parts ・ Ion-exchanged water 77.6 parts

  In a stainless steel container whose liquid level is about 1/3 of the height of the container when all of the above components are added, 28 parts of ion-exchanged water and 2.4 parts of an anionic surfactant After sufficiently dissolving the surfactant, all of the pigment was added, and the mixture was stirred using a stirrer until there was no wet pigment, and was sufficiently degassed. After defoaming, the remaining ion-exchanged water was added, and the mixture was dispersed for 10 minutes at 5000 revolutions using a homogenizer (manufactured by IKA, Ultra Tarrax T50). After defoaming, the mixture was dispersed again at 6000 rpm for 10 minutes using a homogenizer, and then defoamed by stirring for one day with a stirrer.

  The amount of precipitation of the obtained dispersion was 14%, and the volume average particle size of the precipitate was 8 μm. Subsequently, the dispersion liquid was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). The dispersion was equivalent to 30 passes in terms of the total amount of waste and the processing capacity of the apparatus. The obtained dispersion was allowed to stand for 72 hours, and the supernatant was collected to obtain a magenta pigment dispersion. Further, the pH of the dispersion was adjusted to 6.5.

The dispersion was dried and the Ca content in the magenta pigment was measured by fluorescent X-ray analysis. The Ca intensity was 95 kcps. Thereafter, ion exchange water was added to adjust the solid content concentration of the dispersion to 15% to obtain a colorant dispersion (6). The number average particle diameter D _50n of the pigment in the dispersion was 97 nm.
The above is summarized in Table 1.

-Colorant dispersion (7)-
・ Naphthol pigment A (Sanyo Dye, CI Pigment Red 238) 20 parts ・ Anionic surfactant (Daiichi Kogyo Seiyaku, Neogen R) 2 parts ・ Ion-exchanged water 78 parts

  Using a homogenizer (Ultra Turrax T50, manufactured by IKA), the above components were mixed with water at 3000 rpm for 2 minutes, further dispersed at 5000 rpm for 10 minutes, and then stirred for one day with a normal stirrer to remove. After foaming, a magenta pigment dispersion was obtained by dispersing for about 1 hour at a pressure of 240 MPa using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006).

After the completion of dispersion, the mixture was cooled at a rate of 125 ° C./min through a heat exchanger to obtain a magenta pigment dispersion. With respect to the pigment obtained by drying this dispersion, an X-ray diffraction pattern of 0 to 35 ° was obtained with an X-ray diffractometer, and the sum of the half widths was determined to be 3. Thereafter, ion exchange water was added to the pigment to adjust the solid content concentration of the dispersion to 15%, thereby obtaining a colorant dispersion (8). Further, the number average particle diameter D _50n of the pigment in the dispersion was 130 nm.

-Colorant dispersions (8) to (11)-
Each dispersion was obtained in the same manner except that the cooling rate after dispersion was controlled as shown in Table 2 in the preparation of the colorant dispersion (7). Each of them was dried in the same manner, and the X-ray diffraction measurement of the pigment was performed to determine the sum of the half widths. Then, each of the colorant dispersions (8) to (11) was similarly prepared. Each half width is also shown in Table 2.

-Colorant dispersion (12)-
・ Naphthol pigment B (CI Pigment Red 238) 20.0 parts ・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) 2.0 parts (as active ingredient, 10% based on colorant) )
・ 78.0 parts of ion exchange water

  Put 28 parts of ion-exchanged water and 2 parts of an anionic surfactant in a stainless steel container whose liquid level is about 1/3 of the container height when all of the above ingredients are added. After sufficiently dissolving the surfactant, all of the pigment was added, and the mixture was stirred using a stirrer until there was no wet pigment, and the foam was sufficiently degassed. After defoaming, the remaining ion-exchanged water was added, and the mixture was dispersed for 10 minutes at 5000 revolutions using a homogenizer (manufactured by IKA, Ultra Tarrax T50). After defoaming, the mixture was dispersed again at 6000 rpm for 12 minutes using a homogenizer, and then defoamed by stirring for one day with a stirrer.

  The amount of precipitation of the obtained dispersion was 16%, and the volume average particle size of the precipitate was 23 μm. Subsequently, the dispersion liquid was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). Dispersion was performed for 35 passes in terms of the total amount of waste and the processing capacity of the apparatus.

After the completion of dispersion, the mixture was cooled at a rate of 125 ° C./min through a heat exchanger to obtain a magenta pigment dispersion. The dispersion was allowed to stand for 72 hours, and then the supernatant was collected and dried, and an X-ray diffraction pattern of 0 to 35 ° was obtained with an X-ray diffractometer, and the sum of the half widths was obtained. It was 3 °. Thereafter, ion exchange water was added to the pigment to adjust the solid content concentration of the dispersion to 15%, thereby obtaining a colorant dispersion (12). Further, the number average particle diameter D _50n of the pigment in the dispersion was 155 nm. Each half width is also shown in Table 2.

-Colorant dispersion (13)-
-Naphthol pigment C (CI Pigment Red 185) 20.0 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) 2.0 parts (as an active ingredient, 10% with respect to the colorant) )
・ 78.0 parts of ion exchange water

  Put 28 parts of ion-exchanged water and 2 parts of an anionic surfactant in a stainless steel container whose liquid level is about 1/3 of the container height when all of the above ingredients are added. After sufficiently dissolving the surfactant, all of the pigment was added, and the mixture was stirred using a stirrer until there was no wet pigment, and the foam was sufficiently degassed. After defoaming, the remaining ion-exchanged water was added, and the mixture was dispersed for 10 minutes at 5000 revolutions using a homogenizer (manufactured by IKA, Ultra Tarrax T50). After defoaming, the mixture was dispersed again at 6000 rpm for 12 minutes using a homogenizer, and then defoamed by stirring for one day with a stirrer.

  The amount of precipitation of the obtained dispersion was 8%, and the volume average particle size of the precipitate was 16 μm. Subsequently, the dispersion liquid was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). Dispersion was performed for 25 passes in terms of the total amount of dust and the processing capacity of the apparatus.

After the completion of dispersion, the mixture was cooled at a rate of 125 ° C./min through a heat exchanger to obtain a magenta pigment dispersion. The dispersion was allowed to stand for 72 hours, and the supernatant was collected. Thereafter, ion exchange water was added to the pigment to adjust the solid content concentration of the dispersion to 15%, thereby obtaining a colorant dispersion (13). Further, the number average particle diameter D _50n of the pigment in the dispersion was 190 nm. Each half width is also shown in Table 2.

(Release agent dispersion)
-Release agent dispersion (1)-
・ 45 parts of polyalkylene wax (FNP0091, melting point: 90 ° C., Nippon Seiwa Co., Ltd., 140 ° C. viscosity: 3.4 mPa · s) 5 parts of cationic surfactant (Neogen RK, Daiichi Kogyo Seiyaku) ・ Ion exchange 200 parts of water

  The above components are heated to 95 ° C. and sufficiently dispersed with a homogenizer (manufactured by IKA, Ultra Tarrax T50), then dispersed with a pressure discharge type gorin homogenizer, and a release agent having a number average diameter of 190 nm and a solid content of 25%. A dispersion (1) was obtained.

-Release agent dispersion (2)-
Carnauba wax (manufactured by Toa Kasei Co., Ltd., melting point: 85 ° C., 140 ° C. viscosity: 7.4 mPa · s) 27 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 0.84 parts (active ingredient) As a release agent, 3.0%)
・ Ion exchange water 72.16 parts

  The above components are sufficiently dispersed while being heated to 95 ° C. with a homogenizer (IKA, Ultra Tarrax T50), and then dispersed with a pressure discharge type homogenizer (Gorin, Gorin homogenizer) to obtain a release agent particle dispersion. Got. The number average particle diameter D50n of the release agent particles was 210 nm. Thereafter, ion exchange water was added to adjust the solid content concentration to 25.8%.

(Colloidal silica mixed dispersion)
As colloidal silica A, 5 parts of ST-OL (Nissan Chemical Co., Ltd., center particle diameter 40 nm) and 2 parts of colloidal silica B as colloidal silica ST-OS (Nissan Chemical Co., Ltd., center particle diameter 8 nm) are mixed. 15 parts of 0.3 mol / l nitric acid was added, 0.3 parts of polyaluminum chloride was further added, and the mixture was allowed to stand at room temperature for 20 minutes and agglomerated into colloidal silica A (ST-0L) / colloidal silica B ( ST-OS).

<Example 1>
(Production of magenta toner)
Resin particle dispersion (1): 470 parts Colorant dispersion (1): 40 parts Colorant dispersion (7): 40 parts Colloidal silica A (ST-0) / Colloidal silica B (ST-OL ) Mixed dispersion: 135 parts, Release agent dispersion (1): 95 parts

  The above components were sufficiently mixed and dispersed in an round stainless steel flask with Ultra Turrax T50. Subsequently, 6 parts of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 47 ° C. with stirring in an oil bath for heating. After maintaining at 47 ° C. for 60 minutes, 300 parts of the resin particle dispersion (1) was slowly added thereto. Thereafter, the pH in the flask was adjusted to 6.0 with a 0.5 mol / L sodium hydroxide aqueous solution, the stainless steel flask was sealed, and heated to 96 ° C. while continuing stirring using a magnetic seal, and the fusion time For 3.5 hours. When the particle diameter at this time was measured with a Coulter counter, the volume average diameter D50 was 5.8 μm.

After completion of the reaction, it is cooled, filtered, sufficiently washed with ion-exchanged water, and then the solid obtained by removing the aqueous medium is washed and dehydrated to obtain a red toner cake containing a wet toner. Magenta toner particles (1) were obtained by vacuum drying.
The volume average particle size of the magenta toner particles (1) was 5.8 μm, the volume average particle size distribution index GSDv was 1.21, and the shape factor SF1 was 130.

  To 100 parts of the obtained toner particles (1), 1.5 parts of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) And blended for 45 seconds at 10,000 rpm using a sample mill. Thereafter, the mixture was sieved with a vibration sieve having an opening of 45 μm to prepare magenta toner (1).

(Carrier production)
Ferrite particles (volume average particle size: 35 μm) 100 parts Toluene 14 parts Perfluorooctylethyl methacrylate / methyl methacrylate copolymer (copolymerization ratio: 15/85) 2 parts Carbon black (VXC72: manufactured by Cabot Corporation) 0.2 parts

First, the above components excluding ferrite particles are stirred for 10 minutes in a sand mill, the dispersed coating solution is weighed, and then this coating solution and ferrite particles are put into a vacuum degassing type kneader at 60 ° C. with stirring. After reducing the pressure to 20 mHg and mixing for 30 minutes, the temperature was increased / decreased, and the mixture was stirred and dried at 90 ° C./−720 mHg for 30 minutes to obtain a carrier. This carrier had a volume resistivity of 10 ¹¹ Ωcm when an electric field of 1000 V / cm was applied.

(Preparation of developer)
To 100 parts of the carrier, 8 parts of toner (1) were blended for 20 minutes with a V-type blender, and then aggregates were removed by a vibrating screen having an aperture of 212 microns to obtain each color developer.

(Preparation of toner for replenishment)
To 2 parts of the carrier, 10 parts of toner (1) was blended for 20 minutes with a V-type blender, and then aggregates were removed by a vibration sieve having an aperture of 212 microns to obtain a replenishing toner.

(Toner characteristics evaluation)
-Pigment dispersibility-
The pigment dispersion in the magenta toner was evaluated by the following method. That is, a cross-sectional image of the toner was observed with a transmission electron microscope (TEM) (100,000 times), the center diameter of the colorant particles was determined by the above-described method, and the determination was made according to the following criteria. The level up to Δ is at a level where there is no problem in actual use.
A: Center diameter is 130 nm or more and less than 150 nm, very well dispersed O: Center diameter is 150 nm or more and less than 180 nm, well dispersed Δ: Center diameter is 180 nm or more and less than 300 nm, dispersed X: Center diameter Is not dispersed more than 300nm

-Release agent dispersibility-
The degree of dispersion of the release agent in the magenta toner was evaluated by the following method. That is, a cross-sectional image of the toner was observed with a transmission electron microscope (TEM) (100,000 times), and the average dispersion diameter of the release agent particles was determined by the above-described method, and judged based on the following criteria. The level up to ○ is at a level where there is no problem in actual use.
A: The average dispersion diameter is 500 nm or more and less than 1000 nm, growing in the most suitable range.
○: The average dispersion diameter is 150 nm or more and less than 500 nm or 1000 nm or more and less than 1500 nm, growing in a suitable range. X: The average dispersion diameter is less than 150 nm or 1500 nm or more, not growing in a suitable range.

-Releasing agent occupation rate-
The occupation ratio of the release agent in the magenta toner was evaluated by the following method. That is, a cross-sectional image of the toner was observed with a transmission electron microscope (TEM) (100,000 times), the area occupied by the release agent particles in the toner was determined, and judged according to the following criteria. The level up to ○ is at a level where there is no problem in actual use.
A: The occupied area ratio of the release agent is 12% or more and less than 20%, and is growing within the most suitable range.
○: Occupied area ratio of release agent is 10% or more and less than 12% or 20% or more and less than 30%, growing in a suitable range ×: Occupied area ratio of release agent is less than 10% or 30% or more Not growing within a suitable range.

(Actual machine evaluation)
-Toner chargeability-
The magenta developer is set in the magenta developer of the DocuCentre Color 500 CP remodeling machine, and the replenishing toner is set in the toner cartridge. The high temperature and high humidity environment (temperature 28 ° C., humidity 85% RH), the low temperature and low humidity environment (temperature) (10 ° C., humidity 15% RH) for 24 hours, and then the developer was rotated. Next, 0.5 g of the developer was collected from the sleeve, and the toner charge amount was measured by a blow-off method using a charge amount measuring device (Toshiba, TB-200). At this time, the charge amount at high temperature and high humidity was A, the charge amount at low temperature and low humidity was B, and the environmental difference in A / B was evaluated according to the following criteria. The level up to Δ is at a level where there is no problem in actual use.
◎: 0.9 or more and less than 1.1, little environmental difference, no problem ○: 0.7 or more, less than 0.9, little environmental difference, no problem Δ: 0.6 or more, less than 0.7, environmental difference Although there is, there is no problem in actual use ×: less than 0.6, unbearable in actual use

-Image tint-
Under an environment of 22 ° C. and 50% RH, the developing toner amount of a solid magenta image was adjusted to 1.8 g / m ² by an image forming apparatus in which the developer was set. An OHP sheet (manufactured by Fuji Xerox Office Supply Co., Ltd.) was used as the paper, and 5 cm × 5 cm of magenta 100% was produced in the approximate center of the paper, and an image was output. The resulting image was visually evaluated for color vividness and judged according to the following criteria. It should be noted that the level up to Δ is a level that does not cause a problem in actual use.
A: Vivid magenta color, no problem.
○: Slightly dark magenta or practically no problem.
Δ: Slightly dark magenta, but no problem.
×: Black magenta color that cannot be used.
The results are summarized in Table 3. In addition, even in the range of ◎, the points noticed except for the darkening are listed in Table 3.

<Examples 2-5, Comparative Examples 1-4>
Magenta toners were prepared in the same manner except that the colorant dispersion and the fusing time were changed as shown in Table 3 in the preparation of the toner in Example 1, and the same evaluation was performed on these toners.
The results are summarized in Table 3.

<Example 6>
(Production of magenta toner)
-400 parts of ion exchange water-186 parts of resin particle dispersion (3) (crystalline polyester resin concentration: 20%)
-Resin particle dispersion (2) 279 parts (amorphous polyester resin concentration: 20%)
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60%) 1.5 parts (0.9 parts as active ingredient)

  The above components were put into a 3 liter reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and maintained at a temperature of 30 ° C. and a stirring rotational speed of 150 rpm for 30 minutes while controlling the temperature with a mantle heater from the outside. Thereafter, 26.4 parts of colorant dispersion (6) (quinacridone pigment dispersion), 61.6 parts of colorant dispersion (7) (naphthol pigment dispersion), and 60 parts of release agent dispersion (2) are added. And held for 5 minutes. As it was, a 1.0% nitric acid aqueous solution was added to adjust the pH to 3.0. Next, the stirrer and the mantle heater were removed, and 0.33 parts of polyaluminum chloride and 37.5 parts of 0.1% nitric acid aqueous solution were mixed while being dispersed at 3000 rpm with a homogenizer (manufactured by IKA Japan: Ultra Tarax T50). After adding 1/2 of the solution, the dispersion speed was set to 5000 rpm, the remaining 1/2 was added over 1 minute, and the dispersion speed was set to 6500 rpm, and dispersed for 6 minutes.

  A reaction vessel was equipped with a stirrer and a mantle heater, and the temperature was raised to 42 ° C. at 0.5 ° C./min while adjusting the number of revolutions of the stirrer so that the slurry was sufficiently stirred. After being held, the particle size was measured with a Coulter counter TA-II type (aperture diameter: 50 μm, manufactured by Coulter, Inc.) every 10 minutes while raising the temperature at 0.05 ° C./min. When the thickness reached 5.0 μm, the additional particle dispersion was added over 5 minutes. After holding for 30 minutes, the pH was adjusted to 9.0 using a 5% aqueous sodium hydroxide solution. Thereafter, while adjusting the pH to 9.0 every 5 ° C., the temperature was raised to 96 ° C. at a temperature rising rate of 1 ° C./min and maintained at 96 ° C. When the particle shape and surface properties were observed every 30 minutes with an optical microscope and a scanning electron microscope (FE-SEM), the particles became almost spherical in the second hour, so the temperature was lowered to 20 ° C. at 1 ° C./min. Solidified.

  Thereafter, the reaction product is filtered and washed with ion-exchanged water. When the filtrate has a conductivity of 50 mS or less, cake-like particles are taken out, and ion-exchanged water having an amount 10 times the particle weight is taken out. When the particles were sufficiently loosened by stirring with a three-one motor, the pH was adjusted to 3.8 with a 1.0% nitric acid aqueous solution and held for 10 minutes. Thereafter, filtration and washing with water were performed again, and when the conductivity of the filtrate became 10 mS or less, water flow was stopped and solid-liquid separation was performed. The obtained cake-like particles were pulverized by a sample mill and dried in an oven at 40 ° C. for 24 hours. Further, the obtained powder was pulverized by a sample mill and then further vacuum-dried in an oven at 40 ° C. for 5 hours to obtain magenta toner particles.

The obtained toner particles had a volume average particle size of 5.9 μm, a GSDv of 1.21, a GSDp of 1.25, and a shape factor SF1 of 123.
To 100 parts of the obtained toner particles, 1.5 parts of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) are added. And blended for 45 seconds at 10,000 rpm. Thereafter, the mixture was sieved with a vibration sieve having an opening of 45 μm to prepare magenta toner (10).

Using this toner (10), a developer was prepared in the same manner as in Example 1, and the same evaluation was performed.
The results are summarized in Table 3.

<Example 7>
A magenta toner (11) was produced in the same manner as in Example 6 except that the colorant dispersion (7) was changed to the colorant dispersion (12) in the production of the toner of Example 6. The obtained toner (11) had a volume average particle size of 5.8 μm, a GSDv of 1.22, a GSDp of 1.23, and a shape factor SF1 of 122.

Using this toner (11), a developer was prepared in the same manner as in Example 1, and the same evaluation was performed.
The results are summarized in Table 3.

<Example 8>
Example 6 except that the colorant dispersion (7) was changed to the colorant dispersion (12) and the colorant dispersion (6) was changed to the colorant dispersion (1) in the production of the toner of Example 6. A magenta toner (12) was produced in the same manner as described above. The obtained toner (12) had a volume average particle size of 5.8 μm, a GSDv of 1.21, a GSDp of 1.22, and a shape factor SF1 of 121.

Using this toner (12), a developer was prepared in the same manner as in Example 1, and the same evaluation was performed.
The results are summarized in Table 3.

<Example 9>
A magenta toner (13) was produced in the same manner as in Example 6 except that the colorant dispersion (6) was changed to the colorant dispersion (1) in the production of the toner of Example 6. The toner (13) obtained had a volume average particle size of 5.8 μm, a GSDv of 1.21, a GSDp of 1.22, and a shape factor SF1 of 120.

Using this toner (13), a developer was prepared in the same manner as in Example 1, and the same evaluation was performed.
The results are summarized in Table 3.

<Comparative Example 5>
A magenta toner (14) was produced in the same manner as in Example 6 except that the colorant dispersion (7) was changed to the colorant dispersion (13) in the production of the toner of Example 6. The obtained toner (14) had a volume average particle size of 6.0 μm, GSDv of 1.21, GSDp of 1.23 and a shape factor SF1 of 126.

Using this toner (14), a developer was prepared in the same manner as in Example 1, and the same evaluation was performed.
The results are summarized in Table 3.

  As shown in Table 3, the quinacridone pigment has a Ca half intensity of 50 to 150 kcps, and the naphthol pigment has a half-width of a peak whose relative intensity with respect to the maximum peak intensity is greater than 25% in the Bragg angle of 0 to 35 °. It can be seen that when the sum is 2 to 5 °, the pigment dispersion in the toner is good, and as a result, the environmental difference in charging characteristics and the color tone as a magenta toner are good.

Claims (4)

An electrophotographic magenta toner containing at least a binder resin and a colorant,
As the colorant, at least a structure represented by the following general formula (1), a quinacridone pigment having a Ca intensity in the range of 50 to 150 kcps in a fluorescent X-ray analysis, and a structure represented by the following general formula (2) And a naphthol pigment having a sum of half widths of peaks having a relative intensity with respect to the intensity of the maximum peak in the X-ray diffraction pattern having a Bragg angle of 0 to 35 ° in the range of 0 to 35 ° is in the range of 2 to 5 °. A magenta toner for electrophotography, comprising:

  The toner further contains a release agent, and the average dispersion diameter of the release agent in the cross section of the toner by observation with a transmission electron microscope image is in the range of 150 to 1500 nm, and the area occupied by the release agent in the cross section of the toner is the cross sectional area. 2. The magenta toner for electrophotography according to claim 1, wherein the amount is in the range of 10 to 35% of the whole. When the binder resin contains a crystalline polyester resin and an amorphous polyester resin, the average primary particle size of the quinacridone pigment is Pq50, and the average primary particle size of the naphthol pigment is Pn50, these are represented by the following formula ( The magenta toner for electrophotography according to claim 2, wherein the relationship 1) is satisfied.
20 nm <Pq50 <Pn50 <150 nm Formula (1)   Forming an electrostatic latent image on the electrostatic latent image carrier, developing the electrostatic latent image with an electrostatic latent image developer containing toner to form a toner image, and covering the toner image 4. A full-color image forming method comprising a step of transferring onto a transfer body and a step of thermally fixing the toner image onto a recording medium. A full-color image forming method comprising using the electrophotographic magenta toner described in the item.