JPH1097102A - Electrostatic charge image developing magenta toner, tow-component developer, color image forming method and production of magenta toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner having high coloring power which covers a wide dynamic range from low density to high density, having high chroma and luminosity, excellent transparency for an OHP, excellent dispersibility of a coloring agent and high resistance against light, and showing a tone which matches with a magenta of a process color ink by incorporating a binder resin and a specified quinacridon pigment which has plural peaks in a specified range in a X-ray diffraction spectrum. SOLUTION: The toner contains a binder resin and a quinacridon having two peaks in 5 to 10 deg. of Bragg angle 2θ range in a X-ray diffraction spectrum. This quinacridon pigment contains a mixture of two compds. expressed by formulae. Namely, by using two compds. having a g-type crystalline structure to product the pigment, the quinacridon pigment is sufficiently dispersed in the magenta toner. Therefore, the obtd. image shows good hue and excellent color reproducibility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magenta toner applied to a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a method for producing the same.
Further, the present invention relates to a two-component developer having a magenta toner and a color image forming method.

[0002]

2. Description of the Related Art With the recent reduction in the price of computer equipment intended for personal users, a video communication system using video has become widespread in full color from the visual world. Under such needs, full-color image forming apparatuses such as printers and copiers, which are one of the output means, are rapidly becoming full-colored, mainly in the low-grade machine market, and color images are more familiar to general users. It is becoming something.

As such full-color output devices, there are generally many methods such as a thermal transfer system, an ink ribbon system, and an ink-jet system, but as a whole, electrophotographic systems occupy the majority. In general, an electrophotographic system uses a photoconductive substance to form an electric latent image on a photoreceptor by various means, and then develops the latent image using a toner, and if necessary, forms a transfer material such as paper. After transferring the toner image, the toner image is fixed by heating, pressurizing, heating and pressurizing or solvent vapor to obtain a color image. In the case of full color, yellow toner which is three primary colors of color material,
The color reproduction is performed using three chromatic toners of magenta toner and cyan toner or four toners including black toner. For example, an electrostatic latent image is formed on the photoconductive layer by passing light from a document through a color separation light passing filter that has a complementary color relationship with the color of the toner. Next, the color toner is held on the support through a development step and a transfer step. Next, the above-described steps are sequentially performed a plurality of times, and while the registration is being performed, the color toners are superimposed on the same support, and a final full-color image is obtained by fixing.

In recent years, demands for higher image quality and higher definition in full-color images have been increasing. For general users who have considered printing, full-color copied images are not yet at a satisfactory level, and they want a level closer to printing and a level closer to photography. That is, realization of uniformity of a solid image over a wide image area in a copied image, uniformity of a halftone image, and a wide dynamic range from high density to low density is desired.
There has been an urgent need to develop a toner capable of outputting a high image density, a toner having a color tone similar to that of printing, a toner having excellent OHP transparency (light transmittance), and a toner having excellent light resistance.

[0005] Therefore, as a coloring agent used in a toner, a coloring agent having high coloring power, excellent color clarity and transparency, excellent light resistance, and excellent dispersibility in a resin is naturally used. The fact is that agents are strongly desired.

On the other hand, as the number of cases where a color copying machine is connected to a computer via a controller and used as a high-quality color printer increases, a color management system for managing the color of the entire system has been proposed. As a result, certain users strongly desire that the output image output by the electrophotographic color copier match the output image of the printing based on the process ink in terms of tint, A toner having the same color tone as described above has also been required.

Although some pigments have been proposed as magenta toner pigments, they have excellent color clarity and transparency.
In addition, quinacridone pigments have been widely used because they are excellent in light resistance.

JP-A-49-27228 and JP-A-57-5
4954 and JP-A-1-142559, etc.
A toner containing only 9-dimethylquinacridone is disclosed. Although this toner was excellent in light resistance, it was hardly a sufficiently vivid magenta toner.

JP-A-64-9466 discloses that a combination of a quinacridone pigment and a xanthene dye or a pigment obtained by raked a xanthene dye is used to improve the vividness of the toner. This toner has not yet obtained sufficient vividness, and has a problem that the color changes and the image is discolored when the image is left for a long time.

JP-A-1-154161 discloses the use of a quinacridone pigment having an average particle diameter of 0.5 μm or less in order to improve the transparency of magenta toner. The transparency of the toner is determined by the pigment and resin, and the method and degree of dispersion in the resin.
A highly transparent magenta toner has not always been obtained.

On the other hand, in the case of a full-color image, color reproduction is carried out by using three chromatic toners of three primary colors of a yellow toner, a magenta toner, and a cyan toner, or four toners including a black toner. In order to obtain an image having a desired color tone, the balance with other colors is important, and attempts have been made to slightly change the color tone of magenta toner.

For example, JP-B-63-18628 discloses a mixture of compounds containing two kinds of substituted quinacridones, and JP-A-62-291669 discloses a mixture of 2,9-dimethylquinacridone and It describes that a mixed crystal with unsubstituted quinacridone is used as a colorant for magenta, has a desired hue, and has been proposed as a colorant for the purpose of also improving the triboelectric charging property of a toner. .

[0013] However, although the color shifts toward yellowish as a whole as compared with the case where 2,9-dimethylquinacridone is used alone, the bluish color is stronger than the hue of magenta ink for offset printing. There were many points to be improved.

There have been many studies aimed at improving the dispersibility of the colorant present in the toner.

JP-A-61-117565 and JP-A-61-156054 disclose a method in which a binder resin, a colorant, a charge control agent and the like are dissolved in a solvent in advance, and the solvent is removed to obtain a toner. Although these are disclosed, they have problems that it is difficult to control the dispersibility of the charge control agent, and that the solvent remains in the final product toner and gives an undesirable odor.

Japanese Patent Application Laid-Open No. 61-91666 discloses a method for producing a toner using a halogen-based solvent. This production method is used because the halogen-based solvent has a strong polarity. There is a disadvantage that the colorant is limited.

JP-A-4-39671, JP-A-4-39671
JP-A-39672 and JP-A-4-242275 disclose a method for producing a toner while applying heat and pressure in a kneader. Such a method is more preferable for dispersing a colorant, but the method for dispersing a toner is preferred. The molecular chains of the constituent binder resin are cut by a strong kneading load, and partial reduction of the molecular weight in the polymer is promoted. Therefore, a high-temperature offset easily occurs in the fixing process. Especially in full-color copying, the latitude of high-temperature offset resistance is much more severe than that of black-and-white toner, because the toner of three or four colors is fixed in a layered manner. It easily causes hot offset.

JP-A-5-34978 discloses that a resin and an aqueous presscake of a pigment are charged into a kneading machine and kneaded with heat to achieve dispersion of the pigment into the resin. However, there is no mention of pigments that take into account the tint and color reproducibility of the toner.

[0019]

SUMMARY OF THE INVENTION It is an object of the present invention to have a high coloring power covering a wide dynamic range from a low density to a high density; high chroma and lightness; excellent OHP transparency; The present invention provides a magenta toner, a method for producing the same, a two-component developer, and an image forming method.

It is an object of the present invention to exhibit good fixability and color mixing properties; to have sufficient triboelectricity; to have high gloss to enhance image quality; to sufficiently prevent high-temperature offset and to have a wide fixable temperature. No toner fusing in the developing device, that is, parts such as a sleeve, a blade and a coating roller; and a magenta toner having good cleaning properties and not filming on a photoreceptor, a method for producing the same, and a two-component toner. The present invention provides a system developer and an image forming method.

The object of the present invention is to eliminate fog; excellent in highlight reproducibility; excellent in solid uniformity; excellent in durability stability; magenta toner, its production method, two-component developer and image forming method Is provided.

[0022]

The present invention comprises a binder resin and at least a quinacridone pigment having two peaks in the range of 5 to 10 degrees in the Bragg angle 2θ in the X-ray diffraction spectrum. Magenta toner for developing electrostatic images.

Further, the present invention relates to a two-component developer having a magenta toner and a carrier, wherein the magenta toner comprises a binder resin and two Magenta toners having a Bragg angle 2θ of 5 to 10 degrees in an X-ray diffraction spectrum. A two-component developer containing at least a quinacridone pigment having a peak of

Further, according to the present invention, a color toner image is formed by combining a magenta toner and at least one of a color toner of a cyan toner and a yellow toner on a recording material, and the color toner image is fixed on the recording material. In the color image forming method, the magenta toner contains a binder resin and a Bragg angle of 2 in an X-ray diffraction spectrum.
The present invention relates to a color image forming method characterized by containing at least a quinacridone pigment having two peaks in the range of θ of 5 to 10 degrees.

Further, the present invention provides a first binder resin, a first dispersion medium and the following structural formula (I) insoluble in the first dispersion medium:

[0026]

Embedded image Compound (I) represented by the formula
And 50% by weight of a paste pigment (I), a second dispersion medium, and the following structural formula (II) insoluble in the second dispersion medium:

[0027]

Embedded image Heating the paste pigment (II) containing 5 to 50% by weight, based on the paste weight, of the compound (II) while mixing under non-pressurization to melt the first binder resin; Distributing or transferring the compound (I) in the paste pigment (I) and the compound (II) in the paste pigment (II) to the molten first binder resin; the first binder resin Melt kneading the compound (I) and the compound (II) to obtain a first kneaded material; drying the obtained first kneaded material; drying the first kneaded material and the second A step of melt-kneading a mixture containing at least a binder resin of the formula (1) to obtain a second kneaded substance; and a step of cooling and then pulverizing the obtained second kneaded substance to obtain a magenta toner. Manufacturing method, wherein the obtained magenta toner is an X-ray In folding spectra, a method for manufacturing a magenta toner, characterized by containing a quinacridone pigment Bragg angle 2θ has two peaks in the range of 5 to 10 degrees.

[0028]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below.

In general, the following structural formula (I)

[0030]

Embedded image It is known that unsubstituted quinacridone (hereinafter referred to as “compound (I)”) has an α, β, γ type crystal structure, wherein β is more than α and γ is more than β. Is superior in light resistance.

On the other hand, β-type and γ-type quinacridones show distinct peak pattern differences in the X-ray diffraction spectrum (β-type: see FIG. 5 and γ-type: see FIG. 3), and also have greatly different colors.

Β-type quinacridone has a strong purple tinge, and γ-type quinacridone has a yellowish color shift as compared with the β-type quinacridone, but has a reduced tinting strength. In fact, when used as a colorant, neither a toner of the desired hue nor a highly colored toner could be obtained.

On the other hand, the following structural formula (II)

[0034]

Embedded image 2,9-dimethylquinacridone (hereinafter referred to as “compound (II)”) has an X-ray diffraction spectrum as shown in FIG. 4 and shows a vivid magenta color, which is used as a toner colorant. When used, a toner having high coloring power can be obtained. However, when compared with the magenta hue of the process ink, it has a characteristic that it has a strong blue tint.

Carmine-based pigments have been widely used as magenta pigments for process inks. However, when they are applied to toners, carmine-based pigments have poor light fastness and quinacridone-based pigments. The difference is obvious when compared.

On the other hand, 2,9-dimethylquinacridone has
When a carmine-based red pigment is used in combination, the hue can be changed to yellowish depending on the amount of the pigment added. However, a blend system of different pigments greatly reduces vividness, and high brightness and high chroma cannot be achieved with the obtained toner at all.

The present inventors have conducted intensive studies on a magenta toner which is excellent in light fastness, has high lightness and chroma, and has a wide color reproducibility, and which has a magenta hue of a process ink. It has been found that the above-mentioned object can be achieved by producing a magenta toner using unsubstituted quinacridone having a type crystal structure and 2,9-dimethylquinacridone under specific production conditions described below. is there.

That is, when the quinacridone pigment contained in the magenta toner has two peaks in the range of 5 to 10 degrees in Bragg angle 2θ in X-ray diffraction analysis, the above object can be achieved.

In the X-ray diffraction spectrum of the colorant in the magenta toner, the Bragg angle 2θ is an important physical property indicating the crystal form of the pigment. In the present invention, the color of the toner depends on the diffraction peak position and the number of peaks. The taste is very different.

That is, when the Bragg angle 2θ is 5 to 1
Having two peaks in the range of 0 degrees means that the toner of the present invention has the compound (I) and the compound (II) having a γ-type crystal structure.

Compounds (I) and (II) used in the present invention
Since both have a quinacridone skeleton, even when the above two compounds are used in combination, no reduction in saturation or lightness is observed, and a desired hue can be controlled.

The magenta toner of the present invention differs greatly from the point that a mixed crystal of the compounds (I) and (II) is used, and that a magenta toner having a desired color tone is obtained by making the most of the characteristics of each compound. .

In the quinacridone pigment of the mixed crystal of the compounds (I) and (II), only one peak appears at a Bragg angle 2θ of 5.6 ± 0.4 degrees in the X-ray diffraction spectrum. The desired color toner cannot be obtained.

In the X-ray diffraction spectrum of the quinacridone pigment contained in the magenta toner, the Bragg angle 2θ
Has only one peak in the range of 5 to 10 degrees when the toner contains only one of the compounds (I) and (II), It is considered that the compound (I) does not have a γ-type crystal structure, and a toner having a desired color tone cannot be obtained.

In the X-ray diffraction spectrum of the quinacridone pigment contained in the magenta toner, the Bragg angle 2θ
Has no peak in the range of 5 to 10 degrees, it means that the pigment is not basically a magenta skeleton pigment, and has high light resistance, high brightness, which is the object of the present invention. This cannot be achieved with high-saturation toner.

In the present invention, it is important that the colorant in the magenta toner is highly dispersed. Preferably, the number average particle size of the colorant in the toner is 0.7 μm or less. 60% by number of particles having a particle size of 0.1 to 0.5 μm and 10% by number of particles having a particle size of 0.8 μm or more
It is desirable that the dispersed particle size of the colorant is controlled so as to contain the following.

That is, the number average particle size of the colorant is 0.7
When the particle size is larger than μm, it means that a large number of colorant particles that are not sufficiently dispersed are basically present, whereby the color reproducibility and the transparency of the transparency film are not good, and the If the colorant particles are present as aggregates in a non-uniform state, the variation in charging among the toner particles becomes remarkable, and the so-called tribo distribution becomes broad. In this case, a desired high-quality full-color image cannot be obtained.

Further, the colorant in the toner of the present invention contains 0.1.
It is preferable to contain 60% by number or more of particles having a particle diameter of 1 to 0.5 μm.

That is, when the dispersed particle size of the colorant has been discussed so far, only the average particle size has been regarded as important. However, the dispersed particle size distribution of the dispersed colorant is important for improving color reproducibility. Is extremely important.

More specifically, when the dispersed particle size of the colorant is broad, a great difference occurs in the degree of dispersion of the colorant among the toner particles. Even if the size is small, irregular reflection of light due to relatively large colorant particles that are not sufficiently dispersed cannot be avoided, and the desired color reproduction cannot be achieved. In particular, in the subtractive color mixing method by superimposing three colors of magenta, cyan, and yellow, it is desirable to have a sharply dispersed particle size distribution as much as possible so as to maximize the spectral reflection characteristics of the colorant.

Basically, the colorant particles having a small particle size of 0.5 μm or less are considered not to have an adverse effect on the light reflection and absorption characteristics, and provide good color reproducibility and excellent transparency of the transparency film. provide. On the other hand, if there are many colorant particles having a particle size of 0.8 μm or more, the brightness and color of the projected image will inevitably decrease.

Therefore, in the present invention, 0.1 to 0.5
Colorant particles having a particle size of μm are contained in an amount of 60% by number or more, preferably 65% by number or more, more preferably 70% by number or more.

Further, in the present invention, it is preferable that 10% by number or less of colorant particles having a particle diameter of 0.8 μm or more are contained, and it is basically preferable that the number of particles of 0.8 μm or more be small. In the case where colorant particles having a large particle diameter of 0.8 μm or more are contained in an amount of more than 10% by number, especially if many colorant particles having such a large particle diameter exist near the surface, the toner is inevitably used. Detachment from the surface is inevitable, causing various problems such as fog, drum contamination, and poor cleaning. Further, when such a color toner is used as a two-component developer, problems such as carrier contamination are caused, and a stable image cannot be obtained in long-term durability. Naturally, good color reproducibility cannot be expected and uniform chargeability cannot be obtained.

The magenta toner produced by using the compounds (I) and (II) is not limited to the quinacridone pigment contained in the magenta toner of the present invention.
That is, it does not satisfy that the Bragg angle 2θ has two peaks in the range of 5 to 10 degrees in the X-ray diffraction spectrum of the quinacridone pigment.

The unsubstituted quinacridone having a γ-type crystal structure used in the present invention changes its crystal structure into a β-type crystal structure when subjected to a strong mechanical strain (ie, load). When manufacturing the toner, it is important to manufacture the magenta colorant so that it does not receive strong mechanical strain.

However, the magenta toner of the present invention uses two kinds of quinacridone pigments.
Quinacridone pigments must be sufficiently mixed, and the magenta toner has a color tone when combined with a color toner of another color, and a projected image by OHP of a color image formed on an OHP sheet. As described above, it is necessary that the magenta colorant in the magenta toner be sufficiently dispersed so as to be in a specific dispersion state.

Therefore, simply reducing the mixing conditions and kneading conditions during the production of the toner in order to reduce the mechanical strain force applied during the production of the toner, the mixing properties of the two kinds of quinacridone pigments and the pigments in the toner are not considered. No magenta toner having excellent dispersibility can be obtained.

In the present invention, compounds (I) and (II) having a γ-type crystal structure are used, for example,
By manufacturing a magenta color toner based on specific manufacturing conditions described later, in the magenta toner,
The quinacridone pigment is sufficiently dispersed, and in the X-ray diffraction spectrum, the Bragg angle 2θ is 5 to 10
It is possible to obtain a magenta toner containing a quinacridone pigment having two peaks in the range of degrees.

In the present invention, the compound (I) and the compound (II) are preferably mixed in a weight ratio of 10:90 to 90:10, and more preferably in a ratio of 2: 1.
0:80 to 70:30, more preferably 30:70
60 to 40 is good.

When the ratio of the compound (I) is less than 10, although the tinting power as a toner is high, the control of the color tone, which is one of the objects of the present invention, is insufficient. It makes a big difference. On the other hand, when the ratio of the compound (I) is larger than 90, the coloring power of the toner itself is reduced, and high image density output cannot be performed. In addition, the color shifts greatly to yellow, and as shown above, in the case of a color image,
Three primary colors of yellow, magenta and cyan
Because the color is reproduced in four colors or black plus it, if the color tone of magenta greatly changes to yellow, the reproducibility of the blue-based color that can be output by subtractive color mixing with cyan is greatly reduced. It is not preferable.

In the toner of the present invention, the compound (I)
2 to 15 parts by weight, more preferably 2.5 to 12 parts by weight, still more preferably 3 to 10 parts by weight, based on 100 parts by weight of the binder resin. Good.

When the total content of the compound (I) and the compound (II) is less than 2 parts by weight, the coloring power of the toner is reduced. If it is difficult to obtain a high-quality image with a high image density, and if the amount is more than 15 parts by weight, the transparency of the toner is reduced, and the transparency of the toner is lowered. In addition, the reproducibility of intermediate colors, as represented by human flesh colors, also decreases. Further, the chargeability of the toner becomes unstable, causing problems such as fog in a low-temperature and low-humidity environment and toner scattering in a high-temperature and high-humidity environment.

The toner of the present invention has excellent light fastness,
JIS K
When a long-term exposure test was carried out substantially according to 7102, little change in color was observed.

The degree of color change was quantitatively evaluated by ΔE in the following equation.

[0065]

(Equation 1)

As the binder resin, various resins conventionally known as binder resins for electrophotographic toners are used.

For example, polystyrene, styrene-based copolymers such as styrene-butadiene copolymer and styrene-acrylic copolymer, polyethylene, ethylene-vinyl acetate copolymer, phenolic resin, epoxy resin, acrylic phthalate resin, Polyamide resin, polyester resin,
Although a maleic acid-based resin or the like is used, in the present invention, when a polyester-based resin is used as the binder resin, good pigment dispersibility and charge stabilization can be achieved. In particular, when the compounds (I) and (II) were used in combination as a coloring agent, the effect was remarkable.

That is, the toner using the compounds (I) and (II) in combination exhibits an effect of preventing an excessive charge amount in a low-temperature and low-humidity environment and suppressing a decrease in the charge amount in a high-temperature and high-humidity environment. .

The reason is not clear, but the carboxyl group or hydroxyl group at the terminal of the polyester is partially bonded to the imino group or carbonyl group in the quinacridone skeleton by a hydrogen bond or an electrostatic bond. It is considered that the compatibility between the resin and the pigment is increased, and as a result, the dispersibility of the colorant is improved and the charging is stabilized.

Further, according to the study of the present inventors, compound (II) has a higher positive chargeability than compound (I), and has a higher chargeability than compound (I) alone. Therefore, the negatively modified toner containing a polyester resin is effective in preventing the charge amount from becoming excessively large under a low-temperature and low-humidity environment.

The suppression of the decrease in the charge amount under high temperature and high humidity is because the pigment blocks the adsorption of water to the functional group at the terminal of the binder resin because of the good pigment dispersibility described above. It is expected that a high charge amount can be obtained and stable under the environment.

Therefore, when a polyester resin is used as the binder resin, a high-quality image having a stable image density without fog can be obtained in long-term durability.

In particular, the following formula (III)

[0074]

Embedded image

(Wherein R is an ethylene group or a propylene group, x and y each represent an integer of 1 or more, and x +
The average value of y is 2-10. A) a carboxylic acid component such as a divalent or higher carboxylic acid, an acid anhydride thereof or a lower alkyl ester thereof (for example, fumaric acid, maleic acid, maleic anhydride, phthalic acid, Polyester resins co-condensed with terephthalic acid, trimellitic acid, pyromellitic acid, etc.) are more preferred because they have sharp melting properties.

Particularly, the acid value of the polyester resin is preferably 2 to 25 mgKOH / g, more preferably 3 to 22 mKOH / g.
gKOH / g, more preferably 5-20 mgKOH / g
When g, excellent charging stability is obtained in each environment.

When the acid value is less than 2 mgKOH / g, the toner tends to charge up and the image density tends to be low under a low temperature and low humidity environment.

When the acid value is more than 25 mgKOH / g, the charge stability with time is poor, and the charge amount tends to decrease with the endurance. Particularly, in a high-temperature and high-humidity environment, image defects such as toner scattering and fog tend to occur. .

Further, considering the storage stability of the toner, the glass transition temperature of the polyester resin is preferably 50 to 75 ° C., and more preferably 52 to 65 ° C.

The glass transition temperature of the polyester resin is 50
When the temperature is lower than 0 ° C., although the fixing property is excellent, the offset resistance is reduced, and the fixing roller is contaminated and the winding around the fixing roller occurs, which is not preferable. Further, the gloss of the image surface after fixing becomes too high, and the image quality deteriorates, which is not preferable.

The glass transition temperature of the polyester resin is 75
If the temperature is higher than ° C., the fixability deteriorates, and the fixing temperature of the copying machine must be increased, and the resulting image generally has low gloss and low color mixing for a full-color toner.

The polyester resin used in the present invention comprises:
The number average molecular weight (Mn) is preferably from 1,500 to 50,
000, more preferably 2,000 to 20,000, and the weight average molecular weight (Mw) is preferably 6,000 to 10,
0000, more preferably 8,000 to 90,000
And Mw / Mn is preferably 2 to 8. A polyester resin that satisfies the above conditions has good heat fixability, improves the dispersibility of the colorant, reduces the fluctuation of the charge amount of the toner, and improves the reliability of image quality.

Number average molecular weight (Mn) of polyester resin
Is less than 1,500 or the weight average molecular weight (Mw) is less than 6,000, the smoothness of the fixed image surface is high and the appearance is vivid, but offset occurs in the durability. In addition, there is a concern about new problems such as a decrease in storage stability, a fusion of the toner in the developing device, and a generation of toner spent in which the toner component adheres to the carrier surface. Further, it is difficult to apply a shear when the toner raw materials are melt-kneaded in the production of the toner particles, the dispersibility of the colorant is easily lowered, and the charge amount of the toner is apt to fluctuate.

Number average molecular weight (Mn) of polyester resin
Exceeds 50,000 or the weight average molecular weight (M
When w) exceeds 100,000, all have excellent offset resistance, but the fixing set temperature must be increased, and even if the degree of dispersion of the colorant can be controlled, the In this case, the surface smoothness at the portion is reduced, and the color reproducibility is easily reduced.

When the Mw / Mn of the polyester resin is less than 2, the generally obtained polyester resin has a small molecular weight itself. Therefore, similarly to the case where the molecular weight is small, the offset phenomenon due to durability, the storage stability, and the like. , Toner fusing in the developing device and toner spent on the carrier are liable to occur, and the charge amount of the toner tends to vary.

When the Mw / Mn of the polyester resin exceeds 8, although the offset resistance is excellent, the fixing temperature must be increased, and even if the degree of dispersion of the colorant can be controlled. In addition, the surface smoothness in the image portion is reduced, and the color reproducibility is easily reduced.

Next, a preferred production method for producing a magenta toner which achieves the object of the present invention will be described.

In the present invention, in order to produce a magenta toner containing a quinacridone pigment having a specific X-ray diffraction spectrum as described above, it is insoluble in the first binder resin and the first dispersion medium. A first paste pigment containing 5 to 50% by weight of pigment particles represented by the compound (I), and 5 to 50% by weight of pigment particles represented by the compound (II) insoluble in the second dispersion medium. The second paste pigment to be contained is charged into a kneader or a mixer, and heated while mixing under non-pressure to melt the first binder resin. Compound (I) of
And a first binder resin heated with the pigment of (II),
That is, after being distributed or transferred to the molten resin phase, the first binder resin and the pigment particles of the compounds (I) and (II) are melt-kneaded, the liquid component is removed and evaporated, and the first binder is dried. A first kneaded material having a resin and pigment particles of compounds (I) and (II) is obtained, and then a second binder resin and, if necessary, an additive such as a charge control agent are added to the first kneaded material. The obtained mixture is heated and melt-kneaded to obtain a second kneaded product, and the obtained second kneaded product is preferably cooled and pulverized and classified to form a toner.

Here, the first binder resin and the second binder resin may be the same or different resins. Further, the first dispersion medium and the second dispersion medium may be the same or different, but usually water is used as the dispersion medium.

In the present invention, the above-mentioned paste refers to a state in which the pigment particles are present in the pigment particle production step without undergoing a single drying step. In other words, the pigment particles are in the state of almost primary particles, and 5 to 50
% By weight. The remaining 5 in the paste
Most volatile liquids account for 0-95% by weight with some dispersants, auxiliaries and the like. This volatile liquid is not particularly limited as long as it is a liquid that evaporates by general heating, but water is preferably used in the present invention also from an ecological point of view.

In the present invention, the insoluble pigment particles are:
Pigment particles insoluble in the dispersion medium, which is a volatile liquid in the paste, and can be dispersed in the paste. For example, when water is selected as the volatile liquid, all water-insoluble pigment particles are insoluble pigment particles.

The first and second paste pigments used in the present invention preferably contain 5 to 50% by weight, more preferably 5 to 45% by weight of water-insoluble pigment particles.

When the content of the insoluble pigment exceeds 50% by weight, the dispersion efficiency in the resin is low, the kneading temperature is high,
Alternatively, the kneading time must be set longer. Further, a strong screw or paddle structure is essential for the kneading device, and this easily causes polymer chain breakage.

Conversely, when the paste pigment contains less than 5% by weight of insoluble pigment in solid content, in order to obtain the desired pigment content, a large amount of the paste pigment must be introduced into the apparatus. In addition, the size of the apparatus cannot be avoided. Further, when the content is less than 5% by weight, the step of removing water in the step after the first kneading is strengthened, and water must be completely blown off, resulting in a large load on the resin. Become.

When kneading or mixing the first and second paste pigments and the first binder resin, the compounds (I) and (I) in the first and second paste pigments in terms of solid content are converted.
I) The ratio of the total amount of the pigment to the first binder resin is preferably 10:90 to 50:50, more preferably 15:85.
~ 45: 55 is good.

When the ratio of the total amount of the pigments of the compounds (I) and (II) to the first binder resin is less than 10% by weight, a large amount of the first binder is used for the first and second paste pigments. The resin to be charged is charged into the kneading machine, and the pigments of the compounds (I) and (II) tend to segregate in the kneaded material. In order to bring the pigment into a homogeneous system, the kneading time must be set long. Not get. In this case, an extra load is applied to the resin, and desired resin characteristics cannot be obtained.

When the ratio of the total amount of the pigments of the compounds (I) and (II) to the first binder resin is more than 50% by weight, the pigment particles of the compounds (I) and (II) in the liquid phase In addition, the transition to the binder resin was not performed smoothly, and in addition, even during the melt-kneading after the pigment particles of the compounds (I) and (II) were transferred, the kneaded product did not show a uniform molten state, and High dispersibility cannot be obtained.

In the present invention, the reason for melt-kneading under non-pressure is that the liquid in the first and second paste pigments, for example, water, vigorously attacks the first binder resin under pressure, and particularly the resin is a polyester. In the case of a resin, there is a possibility that a hydrolysis reaction may be partially caused or the resin may be deteriorated. In this case, the properties of the binder resin are largely changed, and the offset resistance may be deteriorated. Therefore, in the present invention, it is preferable to perform melt-kneading of the first binder resin and the first and second paste pigments under no pressure.

In the present invention, examples of the kneading apparatus used in the first kneading step include a heating kneader, a single-screw extruder, a twin-screw extruder, and a kneader, and particularly preferably a heating kneader.

The first kneaded material in which the colorant is uniformly dispersed in the first binder resin in the first kneading step is the second kneaded material.
After kneading with the binder resin, the second kneading is performed.

In the second kneading step, other toner constituent materials such as a charge controlling agent and wax are mixed together with the first kneaded material and the second binder resin to obtain a second mixture. The second kneaded product is obtained by melt-kneading the second mixture.

The purpose of performing the kneading separately in the first kneading step and the second kneading step is to use a paste pigment in the first kneading step when the colorant is melt-kneaded with the binder resin. The object of the present invention is to satisfactorily melt-knead a colorant with a binder resin without applying a too high share and at a very high concentration.

Usually, the content of the colorant in the color toner is 2
~ 15% by weight and the amount of colorant is small,
When the colorant and the binder resin are melt-kneaded at once, it is difficult to sufficiently disperse the colorant in the color toner.

According to the manufacturing method of the present invention in which kneading is performed separately in the first kneading step and the second kneading step,
The content of the colorant in the mixture of the colorant and the first binder resin in the kneading step is set to a very high state as compared with the content of the colorant in the color toner to be produced, In addition, since the kneading can be carried out without using a too high share by using the paste pigment, the colorant is sufficiently dispersed in the first binder resin to obtain a kneaded product, and the kneaded product is manufactured. Increasing the dispersibility of the colorant in the produced color toner by melt-kneading and diluting with the second binder resin again so as to have the set content of the colorant in the color toner to be produced. Can be.

In particular, at the time of the second kneading, it is preferable to use a charge control agent and a wax together with the second binder resin to melt-knead with the first kneaded material.

The mixing ratio of the first kneaded material and the second binder resin at the time of the second kneading is appropriately adjusted so as to become the content set by the colorant contained in the color toner to be produced. Adjusted.

As the kneading apparatus used in the second kneading step, the kneading apparatus used in the above-described first kneading step can be used.

After cooling, the second kneaded material obtained in the second kneading step is coarsely pulverized, and the obtained coarsely pulverized material is finely pulverized.
By classifying the obtained finely pulverized product, color toner particles can be obtained.

When a magenta toner is manufactured using a powder pigment without using the paste pigment described above, it can be manufactured under the following manufacturing conditions.

That is, the powdered pigments of the compounds (I) and (II) and the first binder resin are charged into a kneader-type mixer, the temperature is increased under non-pressure while mixing, and the mixture is sufficiently premixed. The first kneaded product may be obtained by kneading twice or more with a kneader such as a three-roll mill.

When kneading or mixing the pigments of compounds (I) and (II) with the first binder resin, the compound (I)
And the ratio of the total amount of the pigment of (II) to the first binder resin is preferably 10:70 to 50:50, more preferably 1:70 to 50:50.
5:85 to 45:55 is good.

The magenta toner of the present invention can be produced by using the powdered pigment according to the production method described above. However, the high dispersibility of the magenta colorant in the magenta toner and the magenta colorant contained in the magenta toner are not sufficient. The use of paste pigments rather than powder pigments makes it compatible with the fact that the compound (I) having the used γ-type crystal structure is not subjected to a strong load during the production and the crystal structure of the compound (I) used is not changed. It is more preferred to produce a toner.

The magenta toner of the present invention is not particularly limited in negative chargeability and positive chargeability, but uses a polyester resin having high negative chargeability as a binder resin, and uses the above-mentioned structural formulas (I) and (II). When the compound group represented by the formula (1) is included, charging stability can be highly enhanced as a negatively charging magenta toner, and high image quality can be stabilized and durability can be improved.

Further, a charge control agent may be added to the toner of the present invention as needed.

Preferably, when a metal compound of an aromatic carboxylic acid derivative, for example, an organic metal compound such as a chromium compound, an aluminum compound or a zinc compound of di-tert-butylsalicylic acid is contained as a negative charge control agent, The magenta toner of the present invention is further stably charged.

When these charge control agents are contained in the magenta toner, the content is preferably 3 to 10% by weight, more preferably 4% by weight based on the weight of the magenta toner.
The range of from 8% by weight to 8% by weight is preferable, but is not necessarily limited as long as it does not affect the color tone of the magenta toner.

When the charge control agent is used at the above content, the initial variation of the charge amount is small, and the absolute charge amount required at the time of development is easily obtained. As a result, image quality such as "fog" and image density reduction may be impaired. Absent.

Further, if desired, a fatty acid metal salt such as zinc stearate and aluminum stearate may be used as a lubricant; for example, fluorine such as polytetrafluoroethylene, polyvinylidene fluoride and tetrafluoroethylene-vinylidene fluoride copolymer Containing polymer fine powder; or a conductivity imparting agent such as tin oxide or zinc oxide;
May be added.

Further, it is preferable to include a release agent as a fixing aid. For example, aliphatic hydrocarbon waxes, aliphatic hydrocarbon wax oxides, waxes mainly containing fatty acid esters, saturated linear fatty acids, unsaturated fatty acids, saturated alcohols, polyhydric alcohols, fatty acids Examples include amides, saturated fatty acid bisamides, unsaturated fatty acid amides, and aromatic bisamides.

The content of the release agent is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the binder resin. When the content of the release agent exceeds 20 parts by weight, blocking resistance and high-temperature offset resistance are liable to decrease, and when the content is less than 0.1 part by weight, the release effect is small.

Further, these release agents are usually contained in the binder resin by a method of dissolving the resin in a solvent, increasing the temperature of the resin solution and adding and mixing while stirring, or a method of mixing at the time of kneading. Is preferred.

The toner of the present invention preferably contains a fluidity improver. As a fluidity improver,
If the fluidity can be increased before and after the addition, it can be used. For example, metal oxide fine powders such as silicic acid fine powder, alumina fine powder, titanium oxide fine powder, zirconium oxide fine powder, magnesium oxide fine powder; boron nitride fine powder, aluminum nitride fine powder, carbon nitride fine powder Nitride such as a body; or resin fine particles of silicone resin fine particles.

In the present invention, calcium titanate, strontium titanate, barium titanate, magnesium titanate, cerium oxide, zirconium oxide, aluminum oxide, titanium oxide, zinc oxide and calcium carbonate are preferably used. It is particularly preferable to use hydrophobicized titanium oxide fine powder or aluminum oxide fine powder having an average primary particle diameter of 0.01 to 0.2 μm.

In the above-mentioned additives, not only increasing the fluidity of the toner but also not inhibiting the chargeability of the toner is an important factor.

Therefore, in the toner of the present invention, it is preferable that the additive is subjected to a surface hydrophobizing treatment, so that it is possible to simultaneously impart fluidity and stabilize charging.

That is, the effect of moisture, which is a factor that affects the charge amount, is eliminated by the hydrophobic treatment.
It is possible to improve the environmental characteristics by reducing the difference in the amount of charge under high humidity and low humidity, and to prevent the aggregation of primary particles by adding a hydrophobic treatment in the manufacturing process. This makes it possible to uniformly charge the toner.

In the present invention, in particular, the average primary particle diameter of titanium oxide or aluminum oxide is 0.01 to 0.2.
When the particle size is μm, the fluidity is good and the toner is uniformly charged, and as a result, toner scattering and fogging are less likely to occur. Further, the toner is hardly embedded on the surface of the toner particles, so that the toner is hardly deteriorated, and the durability of a large number of sheets is improved. This tendency was more remarkable in the sharp melt toner used in the present invention.

When the toner of the present invention is combined with the fine powder, the amount of the fine powder added is 0.5 to 5.0% by weight, preferably 0.7 to 3.0% by weight, and more preferably 1. 0 to 2.5% by weight is good. When the above range is satisfied, the fluidity of the toner is good, a stable charge amount can be maintained, and the toner is hardly scattered.

The weight average particle diameter of the magenta toner of the present invention is preferably 3 to 10 μm, more preferably 4 to 9 μm.

When the toner of the present invention is used as a two-component developer, the carrier to be used may be, for example, iron, nickel, copper, zinc, cobalt, or the like, whose surface is oxidized or not oxidized.
Magnetic metals such as manganese, chromium and rare earths, their magnetic alloys, their magnetic oxides and their magnetic ferrites can be used.

When the carrier is a carrier obtained by coating a carrier core with a coating material, a method for coating the surface of the carrier core with a resin is to dissolve or suspend a coating material such as a resin in a solvent and apply the coating. Either a method of attaching to a carrier core or a method of simply mixing with a powder can be applied.

The substance to be fixed to the carrier core surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal complex of ditersharry butylsalicylic acid, and styrene. Resin, acrylic resin, polyamide, polyvinyl butyral, nigrosine, amino acrylate resin,
It is suitable to use the basic dye and its lake, fine silica powder and fine alumina powder singly or in combination, but it is not necessarily limited thereto.

The amount of the compound to be treated may be determined as appropriate, but is generally preferably 0.1 to 30% by weight (preferably 0.5 to 20% by weight) based on the total amount of the carrier.

The average particle size of the carrier is 10 to 100 μm,
It preferably has a thickness of 20 to 70 μm.

A particularly preferred embodiment is a magnetic ferrite, the surface of which is (i) a silicone resin or (i)
i) It is preferable to coat with a combination of a fluorine resin and a styrene resin. Examples of the combination of the fluorine resin and the styrene resin include polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene and styrene-methyl methacrylate resin; a fluorine copolymer and a styrene copolymer; The mixing ratio of the fluororesin: styrene-based resin is 9
0:10 to 20:80, preferably 70:30 to 30:
70 is preferable. The magnetic ferrite is coated with the above coating material in an amount of 0.01 to 5% by weight, preferably 0.1 to 1% by weight, and has a 250 mesh pass, 400 mesh on carrier particles having an average particle size of 70% by weight or more. Is preferred. As the fluorine-based copolymer, a vinylidene fluoride tetrafluoroethylene copolymer (copolymerization weight ratio of 10:90)
To 90:10). Examples of the styrene-based copolymer include styrene-2-ethylhexyl acrylate (copolymerization weight ratio: 20:80 to 80:20) and styrene-2-ethylhexyl acrylate-methyl methacrylate (copolymer). Polymerization weight ratio of 20 to 60: 5 to 30:10 to 50).

When the coated magnetic ferrite carrier has a sharp particle size distribution, favorable triboelectrification properties are obtained with respect to the magenta toner of the present invention, and there is an effect of improving electrophotographic properties.

When a two-component developer is prepared by mixing with the magenta toner in the present invention, the mixing ratio is 2 to 15% by weight, preferably 3 to 13% by weight, as the toner concentration in the developer. , More preferably 4% by weight to 1%.
Good results are usually obtained at 0% by weight. If the toner concentration is less than 2% by weight, the image density tends to be low.
If it exceeds 5% by weight, fogging and scattering in the machine tend to occur, and the useful life of the developer tends to be shortened.

Crystal Structure Analysis Method In the present invention, the crystal structure analysis is performed as follows.

When performing X-ray diffraction of the colorant in the magenta toner, the magenta toner is dissolved in THF (tetrahydrofuran) or chloroform, and separated into a soluble component and an insoluble component using a Soxhlet extraction tube. The sample which has been sufficiently dried is left at 23 ° C./60% RH for 24 hours or more to be used as a measurement sample.

When the magenta toner contains a charge control agent which is insoluble in THF or chloroform, the charge control agent is contained in the above-mentioned measurement sample. In some cases, a diffraction pattern based on the charge control agent may appear. Therefore, the charge control agent alone is subjected to X-ray crystal structure analysis to confirm the diffraction pattern of the X-ray diffraction spectrum in advance, and the Bragg angle 2θ is 5 to 5 in the X-ray diffraction spectrum of the charge control agent alone. When the peak has a peak in the range of 10 degrees, the Bragg angle of the colorant is obtained by removing the peak in the range of 5 to 10 degrees based on the charge control agent from the X-ray diffraction spectrum of the measurement sample. The peak has 2θ in the range of 5 to 10 degrees.

In the case of performing X-ray diffraction of a colorant or a charge control agent alone, a sample which has been left at 23 ° C./60% RH for 24 hours or more is used as a measurement sample.

The X-ray crystal structure analysis shows that the characteristic X-ray
In an X-ray diffraction spectrum using α-rays as a radiation source,
It is determined from the diffraction pattern of the Bragg angle (2θ). As a measuring device, for example, a powerful full-automatic X-ray diffractometer MXP
¹⁸ (manufactured by Mac Science) can be used, but there is no particular limitation. In the present invention, the peak is SN
It means that the ratio (signal-noise ratio) is 4 or more.

As an example, the spectrum of the β-type compound (I) is shown in FIG. 5, and the spectrum of the γ-type compound (I) is shown in FIG.
FIG. 4 shows the spectrum of the compound (II).

When 2θ is in the range of 5 to 10 °, the β-type compound (I) has 5.7 ± 0.3 ° (see FIG. 5).
6.3 ± 0.3 degrees for γ-type compound (I) (see FIG. 3)
In the case of compound (II), 5.4 ± 0.3 degrees (see FIG. 4)
A clear peak is observed.

Measurement of Average Particle Diameter of Colorant Toner is added to a 2.3 M sucrose solution, stirred well, and put in a small amount in a sample holder bottle, and then poured into liquid N ₂ to be solidified. Set to.

Samples were prepared by cutting with an ultramicrotome FC4E equipped with a cryo-apparatus (manufactured by Nissan Sangyo) according to a conventional method.

A photograph was taken at an acceleration voltage of 100 kV using an electron microscope Model H-8000 (manufactured by Hitachi, Ltd.). The magnification is arbitrary according to the sample.

The image information is introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, and
Convert to value image data. Among them, only the pigment particles having a particle size of 0.1 μm or more shall be analyzed at random, and the measurement is repeated until the sampling number exceeds 300 times, the number average particle size of the pigment particles required in the present invention, In addition, the particle size distribution was determined.

That is, here, only particles larger than 0.1 μm were measured. In addition, the particle diameter referred to in the present invention is a value defined by a diameter obtained after spherically approximating each pigment particle image.

Measurement of Particle Size Distribution of Toner A Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter Inc.) is used. The electrolyte is about 1% using primary grade sodium chloride.
Prepare an aqueous NaCl solution. For example, ISOTON R
-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant (preferably an alkylbenzene sulfonate) is used as a dispersant in 100 to 150 ml of the electrolytic aqueous solution, and 0.1 to 5 ml.
ml, and 2 to 20 mg of the measurement sample. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic
Using a 00 μm aperture, the volume and number of toner particles are measured for each channel, and the volume distribution and number distribution of toner are calculated. Then, the weight-average particle size (D ₄ ) of the toner on a weight basis determined from the volume distribution of the toner particles.
And a volume average particle diameter (D _V ) (the median value of each channel is a representative value for each channel).

The channels are 2.00 to 2.52
μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm
m; 4.00 to 5.04 μm; 5.04 to 6.35 μm
m; 6.35 to 8.00 μm; 8.00 to 10.08 μm
m; 10.08 to 12.70 μm; 12.70 to 16.
00 μm; 16.00-20.20 μm; 20.20
25.40 μm; 25.40-32.00 μm;
13 channels of 00 to 40.30 μm are used.

Next, the color image forming method of the present invention will be described.

According to the color image forming method of the present invention, a color toner image is formed on a record by using a combination of a magenta toner and a color toner of at least one of a cyan toner and a yellow toner. The image is heated and fixed on the recording material to obtain a color image,
The magenta toner has the structure of the magenta toner of the present invention.

FIG. 6 relates to the color image forming method of the present invention.
A full-color image forming apparatus using the color image forming method of the present invention shown in FIG.

FIG. 6 is a schematic diagram showing an example of an image forming apparatus for forming a full-color image by electrophotography. The image forming apparatus shown in FIG. 6 is used as a full-color copying machine or a full-color printer. In the case of a full-color copying machine, as shown in FIG. 6, a digital color image reader unit is provided at the upper part, and a digital color image printer unit is provided at the lower part.

In the image reader section, the original 30 is placed on an original platen glass 31 and is exposed and scanned by an exposure lamp 32, so that a reflected light image from the original 30 is condensed on a full color sensor 34 by a lens 33, and a color image is formed. Obtain a decomposed image signal. The color-separated image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown) and sent to a digital image printer unit.

In the image printer section, a photosensitive drum 1 as an image carrier has a photosensitive layer having, for example, an organic photoconductor, and is carried rotatably in the direction of the arrow. Around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2, a laser exposure optical system 3, a potential sensor 12, four developing devices 4Y, 4C, 4M, 4K of different colors, and a light amount detecting means 13 on the drum , A transfer device 5 and a cleaning device 6 are arranged.

In the laser exposure optical system, an image signal from the reader section is converted into an optical signal for image scan exposure by a laser output section (not shown), and the converted laser light is reflected by the polygon mirror 3a. The light is projected onto the surface of the photosensitive drum 1 via the lens 3b and the mirror 3c.

[0159] The printer unit is provided with a photosensitive drum 1 for forming an image.
Is rotated in the direction of the arrow, and after the charge is removed by the pre-exposure lamp 11, the photosensitive drum 1 is uniformly negatively charged by the charger 2 to irradiate a light image E for each of the separated colors, and the electrostatic charge is charged on the photosensitive drum 1. Form an image.

Next, a predetermined developing device is operated to develop the electrostatic charge image on the photosensitive drum 1 to form a toner image on the photosensitive drum 1 with toner. Developing units 4Y, 4C, 4M,
4K is each eccentric cam 24Y, 24C, 24M,
By the operation of 24K, development is performed by selectively approaching the photosensitive drum 1 in accordance with each separation color.

The transfer device includes a transfer drum 5a, a transfer charger 5b, an attraction charger 5c for electrostatically attracting a transfer material as a recording material and an attraction roller 5g opposed thereto, an inner charger 5d, and an outer charger. And a disassembly charger 5h. The transfer drum 5a is rotatably supported so as to be rotatable, and a transfer sheet 5f, which is a transfer material carrier that supports a transfer material in an opening area of a peripheral surface thereof, is integrally adjusted on a cylinder. A resin film such as a polycarbonate film is used for the transfer sheet 5f.

The transfer material is transported from the cassette 7a, 7b or 7c to the transfer drum 5a through a transfer sheet transport system, and is carried on the transfer drum 5a. The transfer material carried on the transfer drum 5a is repeatedly conveyed to the transfer position facing the photosensitive drum 1 as the transfer drum 5a rotates, and is transferred onto the transfer material by the action of the transfer charger 5b in the process of passing through the transfer position. Is transferred onto the photosensitive drum 1.

As shown in FIG. 6, the toner image may be directly transferred from the photoconductor to a transfer material, or the toner image on the photoconductor may be transferred to an intermediate transfer member, and the toner image may be transferred from the intermediate transfer member. It may be transferred to a material.

The above-described image forming process is performed by using yellow (Y),
By repeating for magenta (M), cyan (C), and black (K), a color image in which four color toner images are superimposed on the transfer material on the transfer drum 5 is obtained.

The transfer material onto which the four color toner images have been transferred in this manner is separated from the transfer drum 5a by the action of the separation claw 8a, the separation push-up roller 8b, and the separation charger 5h, and is heated and pressed by the fixing device. 9, where the toner is heated and pressurized and fixed to perform color mixing and color development of the toner and fixation to the transfer material. After forming a full-color fixed image, the image is discharged to the tray 10 and the formation of the full-color image is completed. I do.
On the other hand, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned and removed by the cleaning device 6. As the cleaning member, besides the blade, a fur brush or a nonwoven fabric, or a combination thereof may be used.

For the transfer drum 5a, the transfer sheet 5
electrode roller 14 and fur brush 1 facing each other
5, an oil removing roller 16 and a backup brush 17 are provided, and the transfer sheet 5 of the transfer drum 5a is provided.
Cleaning is performed to remove the powder adhered on the transfer sheet 5f and the oil adhered on the transfer sheet 5f. Such cleaning,
It is performed before or after image formation, and is performed as needed when a jam, that is, a paper jam occurs.

The gap between the transfer sheet 5f and the photosensitive drum 1 can be arbitrarily set by operating the eccentric cam 25 at a desired timing and operating the 29 cam follower 5i integrated with the transfer drum 5a. is there. For example, the interval between the transfer drum 5a and the photosensitive drum 1 can be increased during standby or when the power is off.

A full-color image is formed by the image forming apparatus. In the image forming apparatus, a single-color fixed image or a multi-color fixed image can be formed in the single-color mode or the multi-color mode.

The image of the present invention having the color image formed on the recording sheet by fixing the recording sheet and the color toner image having at least the magenta toner of the present invention to the recording material sheet by the image forming process described above. A sheet is obtained.

In the above description, a full-color image is formed using four color toners of black toner in addition to cyan toner, magenta toner and yellow toner. However, black image formation is performed without using black toner. 3 of cyan toner, magenta toner and yellow toner
It is also possible to form a full-color image using the three chromatic toners by using chromatic toners of colors.

[0171]

EXAMPLE 1 Polyoxypropylene (2.2) -2,2-bis 30 mol% (4-hydroxyphenyl) propane Polyoxyethylene (2.0) -2,2-bis 70 mol% (4 -Hydroxyphenyl) propane-30 mol% of terephthalic acid-70 mol% of fumaric acid-0.05 mol% of trimellitic acid 70 parts by weight of a polyester resin obtained by a condensation reaction of the above-mentioned raw materials Contains the compound (I) having a γ-type crystal structure A certain amount of water is removed from the pigment slurry, and a first paste-like pigment having a solid content of 30% by weight (the remaining 70% by weight is water) 50 parts by weight of the compound (II) is obtained without any drying step. The water content is removed to some extent from the pigment slurry contained, and the solid content obtained without passing through the drying step 3 times
0% by weight of the second paste-like pigment (the remaining 70% by weight is water) 50 parts by weight

(First Kneading Step) The above-mentioned raw materials are first charged into a kneader-type mixer with the above-mentioned formulation, and the temperature is raised under non-pressure while mixing. Maximum temperature (necessarily determined by the boiling point of the solvent in the paste, in this case 90 to 10
(About 0 ° C.), the pigment in the aqueous phase is distributed or transferred to the molten resin phase.
The mixture is heated, melted and kneaded for a minute to sufficiently transfer the pigment in the paste. After that, once the mixer was stopped and the hot water was discharged, the temperature was further raised to 130 ° C., and the mixture was heated and kneaded for about 30 minutes to disperse the pigment and distill off the water. After cooling, the kneaded material was taken out to obtain a first kneaded material. The water content of the first kneaded product was about 0.5% by weight.

The first kneaded product (pigment particle content: 30% by weight) 16.7 parts by weight Polyester resin 88.3 parts by weight Aluminum compound of di-tert-butylsalicylic acid (charge control agent) 4.0 parts by weight

(Second Kneading Step) Premixing was sufficiently carried out with a Henschel mixer according to the above formulation, the temperature was set to 100 ° C. with a twin-screw extruder and melt kneading was performed. It was coarsely pulverized to about 2 mm, and then finely pulverized to a particle size of 20 μm or less by a fine pulverizer using an air jet method. Further, the obtained finely pulverized product was classified and selected so that the volume average diameter in the particle size distribution became 6.2 μm, thereby obtaining magenta toner particles (classified product). For the purpose of improving fluidity and imparting charging characteristics, alumina fine powder which has been hydrophobized with a Si-based compound is used as magenta toner particles 100.
1.5 parts by weight of an external additive was added to the parts by weight to obtain a magenta toner (A). The weight average particle size of the obtained magenta toner is 6.5.
μm.

When the degree of dispersion of the magenta colorant in the magenta toner (A) was examined, the number average particle size was found to be 0.
28%, particles of 0.1 to 0.5 μm are 83% of the total,
Particles having a particle diameter of 0.8 μm or more were substantially 0%, and excellent dispersibility was achieved.

After adding the magenta toner (A) to water containing a surfactant and removing external additives by ultrasonic vibration, a measurement sample containing a colorant is prepared by the method described above, and then X-ray Diffraction data was taken. Note that chloroform was used as a solvent for dissolving the magenta toner. The data obtained is shown in FIG. It was separately confirmed that among the spectra in FIG. 1, those other than those shown in FIGS. 2 and 3 were caused by the charge control agent contained in the toner.

In the quinacridone pigment contained in the magenta toner (A), as shown in FIG. 1, two clear peaks were confirmed in the range of 5 to 10 degrees in 2θ in the X-ray diffraction spectrum.

[0179] 6.0 parts by weight of this magenta toner (A) was coated with about 0.35% by weight of styrene-methyl methacrylate (copolymer weight ratio 65:35).
-A Zn-Fe-based ferrite carrier was mixed to make the total amount 100 parts by weight to obtain a two-component developer. The toner concentration in the two-component developer was 6.0% by weight.

This two-component developer was applied to a commercially available plain paper full-color copying machine (color laser copier 80, shown in FIG. 6).
A copy test was performed using the magenta developing device 127M of 0). In this copying test, an initial image was obtained, but the color tone was excellent in saturation and vivid.

Further, even after the endurance of 60,000 sheets, a magenta color image faithfully reproducing the original without fog was obtained, and the color reproducibility was excellent. The conveyance in the copying machine and the detection of the developer density were good, and a stable image density was obtained. Even when the fixing temperature was set to 170 ° C. and the copy was repeated 50000 times, no offset to the fixing roller occurred. The occurrence of offset to the fixing roller was determined by visually observing the surface of the fixing roller after repeated copying.

The charge amount was measured under low temperature and low humidity (15 ° C./10% RH) and high temperature and high humidity (32.5 ° C./85% RH). The charge ratio depending on the environment was 1.35.

As a method of evaluating a color copied image, there is a method of determining the quality of a color image by measuring the gloss (gloss) of the image surface. That is, as the gloss value is higher, the image surface is determined to have a smoother, more glossy color quality with high gloss, and when the gloss value is lower, it is determined that the image surface is less dull and less saturated. In Example 1, the image density at a contrast potential of 300 V was 1.70 (Macbeth reflection density), and the gloss at that time was 21%.

For the measurement of gloss (gloss), a VG-10 type gloss meter manufactured by Nippon Denshoku Co., Ltd. was used. When measuring,
First, the voltage was set to 6 V by a constant voltage device. Then, the light emitting angle and the light receiving angle were adjusted to 60 °, respectively, using a zero point adjustment and a standard plate. After standard setting, three blank sheets were stacked on the sample table. The sample image was placed on the sample and measured, and the numerical value shown in the marked part was read in%.

The desired chromaticity of the obtained image was obtained. That is, a ^* = 75.2b ^* =-2.3 L ^* =
47.3.

The color tone of the toner was quantitatively measured based on the definition of a color system standardized by the International Commission on Illumination (CIE) in 1976. At that time, the image density was fixed at 1.70,
a ^* , b ^* (a ^* , b ^* are chromaticities indicating hue and saturation), L
^* (Lightness) was measured. A spectrophotometer type 938 manufactured by X-Rite was used as the measuring instrument, the light source for observation was C light source, and the viewing angle was 2 °.

Further, the color image formed on the transparency film is transferred to an overhead projector (O).
HP), the transparency of the OHP image projected was also good.

The transparency of the OHP image in the above examples was evaluated based on the following evaluation criteria by projecting a color image formed on a transparency film using a commercially available overhead projector.

(Evaluation Criteria) A: Excellent transparency, no unevenness of light and dark, and excellent color reproducibility. (Good) B: Although there is slight unevenness in brightness, there is no practical problem.
(Possible) C: Light and dark unevenness and poor color reproducibility. (Impossible) The light resistance of the obtained solid image (image density 1.70) was determined by JI
It was confirmed substantially according to SK7102 that the image density after light irradiation for 400 hours was almost the same as the initial image density (1.6).
8) and little change in hue was observed (ΔE
= 2.8). Note that a carbon arc lamp was used as a light source.

The hue change was quantitatively evaluated by determining the ΔE value of the following equation.

[0190]

(Equation 2) Light resistance rank A: Almost no change in 400 hour test B: Almost no change in 200 hour test C: Discoloration in 100 hour test

Using the yellow toner and cyan toner for CLC800 and the above magenta toner (A), CL
When the reproduction of secondary colors of red and blue was observed with C800, high lightness and high chroma were obtained. In particular, the saturation (C ^* ) obtained by the following equation was greatly increased to 83.0 in the red image.

[0192]

(Equation 3)

[0193]

[Table 1]

Further, when a full-color image was formed by CLC800 using the yellow toner, cyan toner, and black toner for CLC800 and the above-described magenta toner (A), color reproducibility was excellent and the entire image had saturation. A vivid full-color image was obtained.

Example 2 70 parts by weight of polyester resin used in Example 1 15 parts by weight of dry powder pigment of compound (I) having a γ-type crystal structure 15 parts by weight of dry powder pigment of 2,9-dimethylquinacridone Department

(First kneading step) The above-mentioned materials were charged into a kneader-type mixer, heated to 130 ° C under no pressure while mixing, and sufficiently preliminarily mixed for about 1 hour. The mixture was melted and kneaded twice at 135 ° C., and after cooling, the kneaded product was taken out to complete the first kneading step.

Next, a second kneading step was performed in the same manner as in Example 1 to obtain a magenta toner (B).

When the evaluation was made in the same manner, the results shown in Table 3 were obtained. Although the saturation and lightness were slightly reduced, an image having a target color tone was obtained.

The degree of dispersion of the magenta colorant in the magenta toner (B) was examined.
42 μm, particles of 0.1 to 0.5 μm account for 61% of the total,
5% of the particles had a particle diameter of 0.8 μm or more. Compared with Example 1, the degree of dispersion of the colorant was worse.

Comparative Example 1 Compound (I) having γ-type crystal structure in Example 1
The first kneading step is completed using only 70 parts by weight of the polyester resin and 100 parts by weight of the second paste pigment (solid content: 30%) of the compound (II) used in Example 1 without using , And thereafter, in the same manner, magenta toner (C)
I got

When the evaluation was performed in the same manner, the initial image density was as high as 1.85, but an image having the desired color tone could not be obtained.

The color reproducibility of red, which is a secondary color, was examined by CLC800 using the yellow toner for CLC800 and the magenta toner (C). The chromaticity (a ^* , b ^* ) and lightness (L ^* ) ) Is as follows, and the saturation (C ^* ) is 75.0.
That is, the color reproduction area was significantly narrower than that of the toner of Example 1.

[0203]

[Table 2]

Comparative Example 2 In Example 1, 70 parts by weight of the polyester resin and the first paste pigment of the compound (I) having a γ-type crystal structure were used without using the second paste pigment of the compound (II). The first kneading step was completed using only 100 parts by weight of a solid content of 30% and the remainder being water. Thereafter, a magenta toner (D) was obtained in the same manner.

When evaluation was made similarly, the initial image density was
The image density was as low as 1.42, and the image density was increased only up to 1.63 even when the image was displayed with the contrast potential increased to 400 V. The chromaticity at this time is a ^* = 68.7, b ^* = 10.5
Thus, a toner having a desired hue could not be obtained.

When the color reproducibility of the secondary color, blue, was examined on the CLC800 using the cyan toner for CLC800 and the above-mentioned magenta toner, the blue color reproduction area was smaller than that of the magenta toner of Example 1. It was narrowing greatly.

Comparative Example 3 70 parts by weight of polyester resin used in Example 1 I. Pigment Red 57: 130 parts by weight

(First Kneading Step) The above-mentioned materials were charged into a kneader-type mixer, and were mixed at 130 ° C. under non-pressure while mixing.
The mixture was melted and kneaded twice at 135 ° C. twice using three rolls.
After cooling, the kneaded material was taken out, and the first kneading step was completed.

Next, a second kneading step was performed in the same manner as in Example 1 to obtain a magenta toner (E).

The magenta colorant isolated from the magenta toner (E) was a strong reddish magenta toner having no clear peak in the range of 5 to 10 degrees in 2θ in the X-ray diffraction spectrum.

The initial charge amount in a high-temperature, high-humidity environment is low, which is presumed to be due to the addition of water to Ca ions contained in the pigment used. When the light resistance of the magenta toner was examined, ΔE after irradiation for 100 hours was as large as 6.8.

Comparative Example 4 70 parts by weight of polyester resin used in Example 1 30 parts by weight of commercially available pigment Hoster pern Pink 02 (manufactured by Hoechst) which is a mixed crystal of unsubstituted quinacridone and 2,9-dimethylquinacridone

(First Kneading Step) The above-mentioned materials were charged into a kneader-type mixer, and were mixed at 130 ° C. under non-pressure while mixing.
The mixture was melted and kneaded twice at 135 ° C. twice using three rolls.
After cooling, the kneaded material was taken out, and the first kneading step was completed.

Next, a second kneading step was performed in the same manner as in Example 1 to obtain a magenta toner (F).

The magenta colorant isolated from the magenta toner (F) showed one clear peak in the range of 5 to 10 degrees in 2θ in the X-ray diffraction spectrum and had a strong blue color tone. .

Although the initial image density was as high as 1.80, the charge amount was high in a low-temperature and low-humidity environment, and the density decreased with the endurance.

Example 3 A magenta toner (G) was prepared in substantially the same manner as in Example 1 except that 100 parts by weight of a styrene / n-butyl acrylate copolymer resin (Tg = 60 ° C.) was used as a binder resin. Obtained.

Although a magenta image having a good color tone was obtained in each environment, when images were formed in three colors together with a yellow toner and a cyan toner for CLC800, green,
The color reproducibility of the red and blue secondary colors was slightly poor, that is, the saturation of the secondary colors was low, and the transparency of the trapene was also lower than that of Example 1. It is considered that this is because the color mixing property of the toner is lower than that of the polyester resin.

Further, fog was slightly observed in each environment. However, everything was within the practical level.

Comparative Example 5 In the first kneading step of Example 1, after the hot water was discharged, the temperature was further raised to 160 ° C., and the heat melting and kneading was performed for about 2 hours. A magenta toner (H) was produced in the same manner as described above.

After the magenta toner (H) was added to water containing a surfactant, and the external additives were removed by ultrasonic vibration, the measurement sample containing the quinacridone pigment prepared by the above-described method was an X-ray In the diffraction spectrum, 2
Only one broad peak was confirmed within the range of θ of 5 to 10 degrees.

When evaluated in the same manner as in Example 1, the color became turbid magenta with a purplish tinge, and both lightness and chroma decreased.

Comparative Example 6 In the first kneading step of Example 1, polyester resin 50 parts by weight Compound (I) paste pigment used in Example 1 100 parts by weight Compound (II) paste used in Example 1 Except that the first kneading step was performed with 100 parts by weight of the pigment and that the first kneaded material was further melt-kneaded eight times with three rolls,
Magenta toner (I) was produced in the same manner as in Example 1.

After the magenta toner (I) was added to water containing a surfactant and the external additives were removed by ultrasonic vibration, the measurement sample containing the quinacridone pigment prepared by the method described above was obtained by X-ray In the diffraction spectrum, 2
Only one broad peak was confirmed within the range of θ of 5 to 10 degrees.

When evaluated in the same manner as in Example 1, no magenta toner having the desired hue could be obtained.

Comparative Example 7 In the first kneading step of Example 2, 70 parts by weight of polyester resin used in Example 1 40 parts by weight of dry powder pigment of compound (I) having γ-type crystal structure 40 parts by weight of a dry powder pigment of 9,9-dimethylquinacridone The above materials were mixed for 3 minutes by using a Henschel mixer having an internal volume of 150 L instead of the kneader-type mixer used in Example 2, and the obtained mixture was mixed in three portions. A magenta toner (J) was produced in the same manner as in Example 2, except that the mixture was melt-kneaded five times with a roll.

After the magenta toner (J) was added to water containing a surfactant and the external additives were removed by ultrasonic vibration, the measurement sample containing the quinacridone pigment prepared by the method described above was obtained by X-ray In the diffraction spectrum, 2
Only one broad peak was confirmed within the range of θ of 5 to 10 degrees.

Evaluation was made in the same manner as in Example 1. As a result, the color became turbid magenta with a purple tinge, and both lightness and chroma decreased.

[0229]

[Table 3]

[0230]

As described above, the magenta toner of the present invention contains a magenta colorant having two peaks in the range of 5 to 10 degrees in Bragg angle 2θ in the X-ray diffraction spectrum. As a result, good hue is exhibited and excellent color reproducibility is obtained.

[Brief description of the drawings]

FIG. 1 is a view showing an X-ray diffraction spectrum of a quinacridone pigment contained in a magenta toner of Example 1.

FIG. 2 is a view showing an X-ray diffraction spectrum of a quinacridone pigment contained in a magenta toner of Comparative Example 5.

FIG. 3 is a view showing an X-ray diffraction spectrum of a γ-type compound (I) used as a colorant in the magenta toner of Example 1.

FIG. 4 is a view showing an X-ray diffraction spectrum of a compound (II) used as a colorant in the magenta toner of Example 1.

FIG. 5: β known as a colorant for magenta toner
FIG. 3 is a view showing an X-ray diffraction spectrum of a compound (I) of a type.

FIG. 6 is a schematic explanatory view showing a full-color image forming apparatus capable of performing a color image forming method using magenta toner of the present invention.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 21, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Embedded image

Embedded image

Embedded image

Embedded image Compound (I) represented by the formula
And 50% by weight of a paste pigment (I), a second dispersion medium, and the following structural formula (II) insoluble in the second dispersion medium:

Embedded image Heating the paste pigment (II) containing 5 to 50% by weight, based on the paste weight, of the compound (II) while mixing under non-pressurization to melt the first binder resin; Distributing or transferring the compound (I) in the paste pigment (I) and the compound (II) in the paste pigment (II) to the molten first binder resin; the first binder resin Melt kneading the compound (I) and the compound (II) to obtain a first kneaded material; drying the obtained first kneaded material; drying the first kneaded material and the second Producing a second kneaded product by melt-kneading a mixture having at least a binder resin of the following; and cooling and pulverizing the obtained second kneaded product to obtain a magenta toner. Wherein the obtained magenta toner is an X-ray In the spectrum, the Bragg angle of 2
A method for producing a magenta toner, comprising a quinacridone pigment having two peaks in the range of θ of 5 to 10 degrees.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 9/10 354 (72) Inventor Ryoichi Fujita 3- 30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Invention Person Iku Iku 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (37)

[Claims] 1. An electrostatic charge containing at least a binder resin and a quinacridone pigment having two peaks in a range of 5 to 10 degrees in Bragg angle 2θ in an X-ray diffraction spectrum. Magenta toner for image development. 2. The electrostatic charge according to claim 1, wherein the quinacridone pigment contains a mixture of a compound represented by the following structural formula (I) and a compound represented by the following structural formula (II). Magenta toner for image development. Embedded image 3. The magenta toner for developing an electrostatic image according to claim 2, wherein the compound represented by the structural formula (I) is an unsubstituted quinacridone having a γ-type crystal structure. 4. The electrostatic image development according to claim 1, wherein the quinacridone pigment dispersed in the magenta toner has a number average particle diameter of 0.7 μm or less. For magenta toner. 5. The quinacridone pigment in the magenta toner contains 60% by number or more of particles having a particle size of 0.1 to 0.5 μm and 10% by number of particles having a particle size of 0.8 μm or more. The magenta toner for developing an electrostatic image according to claim 4, wherein: 6. The compound represented by the structural formula (I) and the compound represented by the structural formula (II) are in a ratio of 10:90 to 90: 1.
3. The composition according to claim 2, wherein the components are mixed at a weight ratio of 0.
3. The magenta toner for developing an electrostatic image according to item 1. 7. A mixture of the compound represented by the structural formula (I) and the compound represented by the structural formula (II) in an amount of 2 to 15 parts by weight based on 100 parts by weight of the binder resin. The magenta toner for developing an electrostatic image according to any one of claims 2 to 6. 8. The magenta toner according to claim 1, wherein the binder resin is a polyester resin. 9. The toner according to claim 1, wherein the magenta toner has a weight average particle diameter of 3 to 10 μm.
The magenta toner for developing an electrostatic image according to any one of the above. 10. A two-component developer having a magenta toner and a carrier, the magenta toner has two peaks in a binder resin and a Bragg angle 2θ of 5 to 10 degrees in an X-ray diffraction spectrum. A two-component developer comprising at least a quinacridone pigment. 11. The two-component composition according to claim 10, wherein the quinacridone pigment contains a mixture of a compound represented by the following structural formula (I) and a compound represented by the following structural formula (II). System developer. Embedded image 12. The compound represented by the structural formula (I) is γ
The two-component developer according to claim 11, which is an unsubstituted quinacridone having a crystal structure of a type. 13. The two-component system according to claim 10, wherein the quinacridone pigment dispersed in the magenta toner has a number average particle size of 0.7 μm or less. Agent. 14. The quinacridone pigment in the magenta toner contains 60% by number or more of particles having a particle size of 0.1 to 0.5 μm and 10% by number of particles having a particle size of 0.8 μm or more. The two-component developer according to claim 13, wherein: 15. The compound represented by Structural Formula (I) and the compound represented by Structural Formula (II) are in a ratio of 10:90 to 90:
The two-component developer according to claim 11, wherein the two-component developer is mixed at a weight ratio of 10. 16. A mixture of the compound represented by the structural formula (I) and the compound represented by the structural formula (II) in an amount of 2 to 15 parts by weight based on 100 parts by weight of the binder resin. The two-component developer according to any one of claims 11 to 15, wherein 17. The two-component developer according to claim 11, wherein the binder resin is a polyester resin. 18. The magenta toner has a particle size of 3 to 10 μm.
18. The two-component developer according to claim 10, having a weight average particle diameter of: 19. The carrier according to claim 10, wherein the carrier comprises a member selected from the group consisting of a magnetic metal, an alloy of a magnetic metal, an oxide of a magnetic metal, and a magnetic ferrite. Two-component developer. 20. The two-component developer according to claim 10, wherein the carrier is a coated carrier obtained by coating a carrier core with a coating material. 21. The carrier according to claim 10, wherein the carrier has an average particle size of 10 to 100 μm.
The two-component developer according to any one of the above. 22. The carrier according to claim 10, wherein the carrier is a resin-coated carrier obtained by coating the surface of a magnetic ferrite with a silicone resin or a mixture of a fluororesin and a styrene-based resin. Two-component developer. 23. A color image in which a magenta toner and at least one of a cyan toner and a yellow toner are combined on a recording material to form a color toner image, and the color toner image is fixed on the recording material. In the forming method, the magenta toner contains at least a binder resin and a quinacridone pigment having two peaks in a range of Bragg angle 2θ of 5 to 10 degrees in an X-ray diffraction spectrum. Color image forming method. 24. The color image according to claim 23, wherein the quinacridone pigment contains a mixture of a compound represented by the following structural formula (I) and a compound represented by the following structural formula (II). Forming method. Embedded image 25. The compound represented by the structural formula (I)
The color image forming method according to claim 23, wherein the quinacridone is an unsubstituted quinacridone having a crystal structure of a type. 26. The color image forming method according to claim 23, wherein the quinacridone pigment dispersed in the magenta toner has a number average particle size of 0.7 μm or less. . 27. The quinacridone pigment in the magenta toner contains 60% by number or more of particles having a particle size of 0.1 to 0.5 μm and 10% by number of particles having a particle size of 0.8 μm or more. The color image forming method according to claim 26, wherein: 28. The compound represented by the structural formula (I) and the compound represented by the structural formula (II) are from 10:90 to 90:
The color image forming method according to claim 24, wherein the components are mixed at a weight ratio of 10. 29. A mixture of the compound represented by the structural formula (I) and the compound represented by the structural formula (II) in an amount of 2 to 15 parts by weight based on 100 parts by weight of the binder resin. The color image forming method according to any one of claims 24 to 28. 30. The color image forming method according to claim 23, wherein the binder resin is a polyester resin. 31. The magenta toner has a particle size of 3 to 10 μm.
The color image forming method according to any one of claims 23 to 30, wherein the color image has a weight average particle diameter of: 32. The color toner image comprising the magenta toner, the cyan toner and the yellow toner, wherein the color image is fixed on the recording material to obtain a full color image. 31. The method for forming a color image according to any one of 31. 33. The color toner image further comprises, in addition to the magenta toner, the cyan toner and the yellow toner,
32. The color image forming method according to claim 23, further comprising a black toner, and fixing the color image to the recording material to obtain a full color image. 34. A first binder resin, a first dispersion medium, and the following structural formula (I) insoluble in the first dispersion medium: Compound (I) represented by the formula
And 50% by weight of the paste pigment (I), the second dispersion medium, and the following structural formula (II) insoluble in the second dispersion medium: Heating the paste pigment (II) containing 5 to 50% by weight based on the weight of the paste of the compound (II) while mixing under non-pressurization to melt the first binder resin; Distributing or transferring the compound (I) in the paste pigment (I) and the compound (II) in the paste pigment (II) to the molten first binder resin; the first binder resin Melt kneading the compound (I) and the compound (II) to obtain a first kneaded material; drying the obtained first kneaded material; drying the first kneaded material and the second Producing a second kneaded product by melt-kneading a mixture having at least a binder resin of the following; and cooling and pulverizing the obtained second kneaded product to obtain a magenta toner. A magenta toner obtained by an X-ray A method for producing a magenta toner, comprising a quinacridone pigment having two peaks in a Bragg angle 2θ of 5 to 10 degrees in a folded spectrum. 35. The method according to claim 34, wherein the first dispersion medium has water, and the second dispersion medium has water. 36. The method for producing a magenta toner according to claim 34, wherein the first binder resin and the second binder resin have the same resin composition. 37. The method according to claim 34, wherein the first binder resin is a polyester resin, and the second binder resin is a polyester resin. .