JPH11237765A - Electrostatic charge image developing yellow toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve low temperature fixability and offset resistance and to enhance coloring performance and transparence and light resistance and fading resistance by specifying a composition of the yellow toner and a binder resin and a yellow colorant. SOLUTION: The yellow toner has a storage elastic modulus G'180 at 180 deg.C and a minimum storage elastic modulus G'min in the range of 120 deg.C-170 deg.C and a ratio of G'180 /G'min of 2.0-8.0, and the binder resin contains a polyester resin having a glass transition point of 50 deg.C-65 deg.C and an acid value of 2.0-25.0 mgKOH/g, and the yellow colorant has a compound represented by the formula and the primary particles of the yellow colorant have an average ratio of longer diameter to shorter diameter of <=1.5 and the yellow colorant present as independent particles has a number average particle diameter of 0.1-0.7 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a yellow toner for developing an electrostatic image in electrophotography, electrostatic recording and electrostatic printing. In particular, the present invention relates to a yellow toner for forming a full-color image or a multi-color image, which has excellent color reproducibility of a full-color image, excellent offset resistance and low-temperature fixability, and excellent environmental stability and durability stability.

[0002]

2. Description of the Related Art In recent years, a full-color copying machine or a full-color printer has attracted attention. In particular, a full-color copying machine or a full-color printer that develops a digitized electrostatic image has attracted attention and is being widely deployed in the market.

[0003] Color image formation by full-color electrophotography generally reproduces colors using three primary color toners of three colors, yellow, magenta, and cyan, or four colors including black.

In the color image forming method, light from an original is passed through a color separation light transmitting filter having a complementary color relationship with the color of the toner, and dots are formed on the photoconductive layer by laser light based on data based on the light passing through the filter. To form an electrostatic image. Next, the toner is held on a support through development and transfer steps. The above-described steps are sequentially performed a plurality of times, and while the registration is being performed, the toner is superimposed on the same support, and the final full-color image of the toner image on the transfer material is obtained by the heat and pressure fixing step.

[0005] A full-color electrophotography in which several types of toner layers having different colors transferred onto a transfer material with or without an intermediate transfer material by performing development a plurality of times as described above is heated and pressed. In the method, the fixing properties of each color toner are important factors.

The fixed color toner is required to suppress irregular reflection due to toner particles as much as possible and to have appropriate gloss and luster.

It is preferable that the upper color toner layer has transparency so as not to hinder the color tone of the lower color toner layer having a different color tone, and it is important that the color toner has a wide color reproducibility. It is.

The present applicants have disclosed in Japanese Patent Application Laid-Open Nos. 50-62442, 51-144625, and 59-144.
No. 57256 proposes a novel color toner in which a binder resin for a color toner and a colorant are combined.

The color toners described above have considerable sharp melt properties, and when combined with a silicone rubber roller capable of being coated with silicone oil, are heated and pressurized in a state close to complete melting at the time of fixing to form toner particles. Changes in shape, so that preferable glossiness and color reproducibility can be obtained.

[0010] In these toners, as a fixing characteristic of the toner, it means that the viscosity term is more important than the elastic term in the viscoelastic property of the binder resin.

When these toners are heated and pressurized, the melt viscosity sharply decreases, and a fixed image having excellent gloss can be obtained.

However, such a binder resin design emphasizing the viscosity term inevitably reduces intermolecular agglomeration in the binder resin at the time of heat melting, and the toner adheres to the heat roller when passing through the fixing device. Also tend to increase. In this case, the high-temperature offset phenomenon easily occurs.

In order to solve or alleviate the above problems, Japanese Patent Application Laid-Open Nos. 55-60960 and 57-20855
No. 9, JP-A-58-11953 and JP-A-58-19553.
JP-A-14144 and JP-A-60-123852 have proposed a method of adding a low-molecular weight polyethylene wax, polypropylene wax, higher fatty acid or the like as a releasing component to toner particles. Although these methods are effective in preventing offset, the inclusion of a large amount of a releasable component in order to sufficiently exhibit offset resistance reduces the transparency of the OHP image of the color toner; the charging characteristics of the color toner Becomes unstable; adverse effects such as a decrease in durability of a large number of color toner sheets are observed.

JP-A-47-12334, JP-A-5-12334
In JP-A-7-37353 and JP-A-57-208559, an etherified bisphenol monomer is used.
Non-linear polyester resin obtained from a monomer component containing a dicarboxylic acid monomer and a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer as a binder Contained toners have been proposed. These toners are obtained by crosslinking a polyester comprising an etherified bisphenol monomer and a dicarboxylic acid monomer with a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer. The offset prevention performance of the toner is improved by incorporating the resulting polyester as a binder resin. However, these toners have a slightly higher softening point, and thus it is difficult to achieve good low-temperature fixing. Further, when used for forming a full-color image, the high-temperature offset resistance is improved, but the low-temperature fixing property and the sharp melt property are difficult. Therefore, the color toner using the polyester resin has a sufficient color mixing property and color reproducibility. is not. JP-A-57-109825, JP-A-62-78568
JP-A-62-78569 and JP-A-59-78569.
No. 7,960, JP-A-59-29256 discloses an etherified bisphenol monomer, a dicarboxylic acid monomer into which a long-chain aliphatic hydrocarbon is introduced, and other dicarboxylic acid monomers, A non-linear copolymer obtained from a monomer component containing a polyhydric alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer as a main chain, and a side chain having 3 to 3 carbon atoms. There has been proposed a toner containing a polyester resin having 22 saturated or unsaturated aliphatic hydrocarbon groups as a binder. The main purpose of these polyester resins is to use them in black toner for high-speed copying. As the viscoelastic properties of these polyester resins, completely opposite to the above-mentioned viscosity-oriented polyester,
The elasticity term is increased, thereby significantly reducing the hot offset to the heating roller. Then, at the time of fixing, the pressure and heating of the heating and pressing roller fixing machine are increased as much as possible, and the toner is pressed between the fibers of the transfer paper in a semi-molten state to perform pressure and heat fixing.

Therefore, these toners do not completely melt the toner layer, do not form a continuous film, and can hardly obtain a smooth surface. The fixed toner is present in the form of particles on the transfer paper, and the resulting color image is dull and has low saturation. In the OHP image in which these toners are fixed, light is scattered on the surface of the toner particles and hardly transmits light, which is not practically preferable. In principle, if there are three primary colors, yellow, magenta, and cyan, almost all colors can be reproduced by the subtractive color mixing method. Ideally, any color tone can be reproduced in any density range. However, in reality, there are still points to be improved such as the spectral reflection characteristics of the toner, the mixing property at the time of superimposing and fixing the toner, and the reduction of the saturation.

When a black color is obtained by superimposing three colors, three times more toner layers are formed on the transfer paper than in the case of a single color, and the difficulty in offset resistance is further increased.

The demand for the quality of a full-color image by electrophotography is increasing more and more. For general users who have considered printing, it is desired that a full-color image by electrophotography has a level closer to printing and a level closer to silver halide photography.

One way to meet these requirements is for the colorant present in the toner particles to be uniformly dispersed.

[0019] JP-A-61-117565 and JP-A-61-156054 disclose a binder resin, a colorant, a charge control agent and the like in a solvent which are dissolved and / or dispersed in advance and the solvent is removed. A method for obtaining a toner is disclosed. These have problems in that it is difficult to control the dispersibility of the charge control agent in the binder resin, that the solvent tends to remain in the final product toner, and that there is a problem of odor. When the solvent is an aromatic solvent such as xylene or toluene, or a ketone solvent such as methyl ethyl kettle or acetone, it is necessary to consider not only the odor but also the effect on the human body.

JP-A-61-91666 discloses a method for producing a toner using a halogen-based solvent.
Since the halogen-based solvent has a strong polarity, there is a problem that a coloring agent to be used 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. Although this method is preferable for dispersing the colorant in the binder resin, the molecular chain of the binder resin constituting the toner is cut by a strong kneading load, and the molecular weight of the polymer component is partially reduced. Therefore, a high-temperature offset easily occurs in the fixing process. In particular, in a full-color image, a toner in which three or four colors of toner are layered is fixed, so that high-temperature offset is likely to occur due to a reduction in molecular weight due to molecular cutting in a polymer component.

On the other hand, in the conventional sharp-melt resin having excellent color reproducibility, when the resin and the colorant are kneaded, the shearing force at the time of kneading does not increase, so that the colorant is hardly dispersed. This tendency is particularly remarkable when a pigment having a high cohesiveness is used as a coloring agent.

Therefore, the design of the resin and the selection of the colorant have a very significant meaning so as to satisfy both the offset resistance and the fixability and also the dispersibility of the colorant.

When a two-component developer having a toner and a carrier is used as the developer, the toner is charged to a required charge amount and charge polarity by friction with the carrier, and the toner is charged by electrostatic attraction. This is for developing an electrostatic image. Therefore, in order to obtain a good toner image, it is necessary that the toner has good triboelectric charging properties.

In recent years, the demand for high definition and high image quality of copying machines or printers has been increasing in the market, and in this technical field, attempts have been made to achieve high image quality and color by reducing the particle size of color toner. ing. As the particle size of the toner becomes smaller, the surface area per unit weight increases, the charge amount of the toner tends to increase, and the image density tends to be low and the durability tends to deteriorate. In addition, since the charge amount of the toner is large, the adhesive force between the toner particles is strong, the fluidity is reduced, and problems are likely to occur in the stability of toner replenishment and the application of tribo to the replenished toner.

Further, in the case of a color toner, since there is no black conductive material such as a magnetic material or carbon black, there is no portion that leaks charge, and the charge amount generally tends to be large. This tendency is more remarkable especially when a polyester resin having high negative charging performance is used as the binder resin.

Although polyester resins are widely used in the art today as binder resins for color toners, yellow color toners having polyester resins are generally susceptible to temperature and humidity, and have an excessive charge under low humidity. In addition, a problem such as insufficient charge amount under high humidity is likely to occur, and development of a yellow color toner having a stable charge amount even in a wide range of environments is expected.

It is known that the charge of the yellow color toner varies greatly depending on the degree of dispersibility of the yellow colorant in the binder resin. For a yellow toner color in which the dispersion of the yellow colorant is poor, fog or toner scattering occurs And various problems such as toner spent on a carrier, toner filming on a drum, and contamination of a fixing roller. Therefore, improvement of the dispersibility of the yellow colorant is an important technical issue in addition to the color reproducibility.

There are many known colorants for yellow toner. For example, JP-A-2-207273 discloses C.I. I. Solvent Yellow 112, JP2
JP-207274 discloses C.I. I. Solvent Yellow 160 and JP-A-8-36275 describe C.I. I. Dyes such as Solvent Yellow 162 are described. JP-A-50-62442 discloses a benzidine yellow pigment, JP-A-2-87160 discloses a monoazo yellow toner, and JP-A-2-208.
No. 662 discloses that C.I. I. Pigment Yellow 120,
Pigments such as 151, 154, 156 are described.

However, conventionally known colorants for yellow toner, although dye-based colorants are generally excellent in transparency, are inferior in light resistance and have a problem in storage stability of images.

Although the above-mentioned yellow pigment is superior in light resistance as compared with dyes, it is more light-fast than quinacridone pigment used for magenta toner and copper phthalocyanine pigment used for cyan toner. However, in a long-time light exposure test, there is a problem that the color is fast or a change in hue is conspicuous.

On the other hand, a yellow pigment which is excellent in light resistance and heat resistance, on the contrary, has too strong concealing property, resulting in an extremely low transparency of the toner, and is not suitable for a yellow pigment for forming a full-color image.

Japanese Patent Publication No. 2-37949 proposes a disazo compound having excellent light resistance and a method for producing the same. This is C.I. I. A group of compounds represented by CI Pigment Yellow 180, which is not only excellent in light resistance and heat resistance, but also one of azo pigments satisfying ecological requirements.

C. I. Pigment Yellow 180 is disclosed in JP-A-6-230607.
JP-A-6-266163, JP-A-8-26279
No. 9, the toner using the above pigment has poor coloring power and transparency is not always good.
Further improvement is required for the yellow toner for full-color image formation.

Japanese Patent Application Laid-Open No. Hei 8-209017 discloses that in order to solve the above-mentioned problem, transparency and coloring power are improved by using a yellow pigment in which the yellow pigment is finely divided to improve the specific surface area of the yellow pigment. And electrophotographic toners. However, C.I. I. When the pigment classified as Pigment Yellow 180 is miniaturized, the negative chargeability of the pigment itself is significantly reduced, and a toner using the pigment has a new charge amount, particularly a charge amount shortage under high temperature and high humidity. The need to solve the problem has arisen.

In addition, since the above-mentioned colorant has a strong self-aggregating property, it is difficult to disperse well in the binder resin constituting the toner. According to our study, in a toner in which the colorant is not well dispersed, it is difficult to stabilize charging, and problems such as fog and toner scattering have occurred.

[0037]

SUMMARY OF THE INVENTION An object of the present invention is to provide a yellow toner for developing an electrostatic charge image which solves the above-mentioned problems.

An object of the present invention is to provide good low-temperature fixability and
Excellent offset resistance, high coloring power, excellent transparency,
An object of the present invention is to provide a yellow toner for developing an electrostatic charge image which has excellent light fastness and does not easily fade.

An object of the present invention is to provide a yellow toner for developing an electrostatic image, which can form a fixed image having high gloss.

An object of the present invention is to provide a yellow toner for developing an electrostatic image in which a yellow colorant in yellow toner particles is finely and uniformly dispersed.

An object of the present invention is to provide a yellow toner for developing an electrostatic image, which is excellent in negative triboelectric charging characteristics.

It is an object of the present invention to provide a yellow toner for developing an electrostatic image, which is excellent in color mixing when forming a full-color image.

An object of the present invention is to provide a yellow toner for developing an electrostatic charge image in which toner fusing to parts such as a developing sleeve, a blade, and a coating roller in a developing device hardly occurs.

An object of the present invention is to provide a yellow toner for developing an electrostatic charge image, which is less likely to cause filming by the toner on a photosensitive member for forming an electrostatic charge image.

An object of the present invention is to provide a yellow toner for developing an electrostatic charge image which is less likely to contaminate a heating roller and a pressure roller and is less likely to cause the transfer material to wind around the heating roller.

[0046]

According to the present invention, there is provided a yellow toner for developing an electrostatic image having yellow toner particles containing at least a binder resin and a yellow colorant. minimum G'mi storage modulus of the yellow toner in the range of the storage modulus G _'180 and the temperature of 120 ° C. to 170 ° C.
n _(120-170) [G ' ₁₈₀ / G'min
_(120-170) ] is 2.0 to 8.0, and the binder resin is
It contains a polyester resin having a glass transition temperature of 50 to 65 ° C., an acid value of 2.0 to 25.0 mg KOH / g, and a yellow colorant represented by the following formula (1)

[0047]

[Outside 3] Wherein the primary particles of the yellow colorant have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of yellow colorants present as independent particles in the yellow toner particles. The present invention relates to a yellow toner for developing an electrostatic image, having an average diameter of 0.1 to 0.7 μm.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION The yellow pigment (CI Pigment Yellow 180) represented by the formula (1) is usually in the form of an acicular crystal in which primary particles have a ratio of major axis to minor axis of more than 1.6. , And contains many particles having a large major axis of primary particles. Such primary particles and secondary particles of the yellow pigment are difficult to produce a highly transparent kneaded product even when melt-kneaded with the binder resin. As mentioned above,
-209017 (Corresponding Canadian Application Publication No. 21)
No. 59872 or corresponding EP-A-705886) to BE
An electrophotographic toner containing an azo yellow pigment represented by the formula (1) containing fine particles having a T specific surface area of more than 45 m ² / g and having a ratio of major axis to minor axis of 1.6 or less. Is described. Even if the azo yellow pigment described in JP-A-8-209017 is simply melt-kneaded with a normal binder resin, the yellow pigment particles composed of fine primary particles have a strong self-aggregating property and the yellow pigment Is difficult to disperse uniformly in the binder resin in the form of fine secondary particles.

In the present invention, the binder resin has a glass transition temperature of 50-65 ° C. and an acid value of 2.0-2.
By using a 5.0 mg KOH / g polyester resin and a toner resin composition having viscoelastic properties in which the storage elastic modulus G 'is improved by heating, a number average particle size (also referred to as a length average particle size) is obtained. ) Is 0.1 to 0.7 μm and the ratio of the major axis to the minor axis of the primary particles is 1.5 or less. Can be dispersed.

The yellow toner of the present invention containing the compound represented by the formula (1) in a fine state as a yellow colorant exhibits a greenish (green) yellow.
It has preferable spectral characteristics as a yellow toner for full-color image formation. Further, the yellow toner containing the compound represented by the formula (1) in a fine state has high lightness and chroma. The reproducibility of human flesh color is important in a full-color image. However, when a yellow toner containing the compound represented by the formula (1) is used, human flesh color can be well reproduced, and the overhead projector (OHP) It is excellent in transparency even when a color image formed on an OHP sheet is projected.

In the present invention, it is important that the yellow colorant in the yellow toner particles is highly dispersed, so that the number average particle size of the yellow colorant in the toner particles is 0.1 to 0.7 μm. is there. Preferably, the colorant in the yellow toner particles has a particle size of 0.1 to 0.5 μm.
60% by number of independent particles (primary particles and secondary particles)
More preferably at least 65% by number, most preferably 7%
Dispersion particle size of the colorant such that 0% by number or more and independent particles (primary particles and secondary particles) having a particle size of 0.8 μm or more are contained in 10% by number, more preferably 0 to 5% by number. Is preferably controlled.

The number average particle size of the yellow colorant is 0.7 μm.
When it is larger than m, it means that a large amount of yellow colorant particles that are not sufficiently dispersed are present in the toner particles, and thus the color reproducibility and the transparency of the transparency film are not good. . Further, if the yellow colorant particles in the toner particles are present as an aggregate in a non-uniform state, the variation in charging between the toner particles becomes remarkable, and the tribo distribution becomes broad. Therefore, a high-quality yellow color image cannot be obtained,
It is also difficult to form a good full-color image.

The yellow colorant in the yellow toner particles comprises particles having a particle diameter of 0.1 to 0.5 μm in an amount of 60% by number or more, more preferably 65% by number or more, and most preferably 7% by number.
It is preferable to contain 0% by number or more.

Until now, when discussing the dispersed particle size of the colorant, only the average particle size has been regarded as important.
The particle size distribution of the dispersed colorant is extremely important for improving color reproducibility.

When the dispersion particle size of the colorant is broad, a large difference occurs in the degree of dispersion of the colorant among the toner particles. If the dispersion of the colorant is poor, irregular reflection of light occurs due to relatively large colorant particles that are not sufficiently dispersed, and it is difficult to achieve the desired color reproduction satisfactorily. In particular, in the subtractive color mixing method by superimposing three colors of magenta, cyan, and yellow, it is preferable that the colorant has as sharp a dispersion particle size distribution as possible so as to maximize the spectral reflection characteristics of the colorant.

It is considered that a coloring agent having a fine particle diameter smaller than 0.1 μm basically does not adversely affect light reflection and absorption characteristics. Colorant particles of less than 0.1 μm contribute to good color reproducibility and transparency of OHP sheets with fixed images. On the other hand, if there are many colorants having a particle size larger than 0.5 μm, the brightness and color of the projected image on the OHP sheet tend to be reduced.

Therefore, 0.1% of the yellow toner particles
It is preferable that the colorant having a particle size of 0.5 μm is contained in an amount of 60% by number or more, preferably 65% by number or more, more preferably 70% by number or more. When a predetermined amount of primary particles and secondary particles of the yellow colorant represented by the formula (1) having a particle size of 0.1 to 0.5 μm is present in the yellow toner particles, a decrease in light resistance of the yellow toner is suppressed. Further, since the yellow color tone becomes greenish, it is more preferable as a yellow toner for a full-color image.

Further, 0.8 μm
It is preferable that yellow colorant particles having the above particle size are contained in an amount of 0 to 10% by number, more preferably 0 to 5% by number,
Basically, it is preferable that there is no or less than 0.8 μm particles. When the yellow colorant having a large particle size of 0.8 μm or more is contained in the toner particles in an amount of more than 10% by number, the yellow colorant having such a large particle size is present near the surface of the yellow toner particles. If so, the yellow colorant is inevitably detached from the surface of the yellow toner particles, and various problems such as fog, drum contamination, and poor cleaning are likely to occur. Further, when such a yellow color toner is used as a two-component developer, a problem such as carrier contamination is caused, and it is difficult to obtain a stable image in multi-sheet durability. Naturally, good color reproducibility cannot be expected, and uniform chargeability is hardly obtained.

In the present invention, the yellow toner contains the yellow colorant represented by the formula (1) in an amount of 1 to 15 parts by weight, preferably 3 to 12 parts by weight, per 100 parts by weight of the binder resin.
More preferably, the content is 4 to 10 parts by weight.

When the content of the yellow colorant represented by the formula (1) is more than 15 parts by weight, the transparency is lowered, and the reproducibility of an intermediate color represented by human skin color is also lowered. It will be easier. Further, the stability of the triboelectrification of the yellow toner is reduced, and it is difficult to obtain a desired negative triboelectric charge.

When the content of the yellow colorant represented by the formula (1) is less than 1 part by weight, it is difficult to obtain a desired coloring power, and it is difficult to obtain a high quality image having a high image density.

The polyester resin has an acid value of 2.0 to 2
When the concentration is 5.0 mgKOH / g, the viscosity of the kneaded material is easily increased gradually during the melt-kneading, and the yellow toner is preferable because excellent charging stability can be obtained in each environment.

The acid value of the polyester resin is 2.0 mg KO
If it is smaller than H / g, it is difficult to increase the viscosity of the kneaded material with time during melt-kneading, and the yellow toner tends to charge up and tends to have a low image density in a low-temperature and low-humidity environment. In addition, the dispersibility of the yellow colorant represented by the formula (1) in the binder resin is reduced, the difference in the amount of charge between the yellow toner particles is likely to occur, and fog tends to occur slightly with long-term durability.

The acid value of the polyester resin is 25.0 mgK
If it is larger than OH / g, the stability over time of the charging of the yellow toner is reduced, and the charging amount is apt to be reduced with the durability. Particularly in a high-temperature and high-humidity environment, image defects such as toner scattering and fogging are likely to occur. Further, it becomes difficult to block the adsorption of moisture of the yellow colorant represented by the formula (1) contained in the yellow toner particles.

The polyester resin preferably has an acid value of 3.0 to 22.0 mgKOH / g, more preferably 5.0 to 20.0 mgKOH / g.

Further, in consideration of the storability and fixability of the yellow toner and the color mixing with other color toners, the glass transition temperature of the polyester resin is 50 to 65 ° C., preferably 52 to 65 ° C., more preferably The temperature is preferably 53 to 64 ° 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.

The glass transition temperature of the polyester resin is 65
If the temperature is higher than ℃, the fixing property is reduced, and the fixing temperature of the copying machine or the printer body must be increased, and the obtained image generally has a low gloss and a low color mixing property with other color toners. I do.

The polyester resin used in the present invention is:
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 10,000 to 90,00
0, 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 yellow colorant, reduces the variation in the charge amount of the yellow 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 when many sheets are used. In addition, storage stability is reduced, and toner fusing in a developing device and toner spent in which a toner component adheres to the carrier surface are likely to occur. Further, shear is not easily applied during melt-kneading of the toner raw material during the production of the yellow toner particles, the dispersibility of the yellow colorant is easily reduced, and the frictional charging characteristics of the generated yellow toner are liable to change.

Number average molecular weight (Mn) of polyester resin
Exceeds 50,000 or the weight average molecular weight (M
When w) exceeds 100,000, 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, even if the degree of dispersion of the colorant can be controlled, Surface smoothness is reduced, and color reproducibility is likely to be 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, an offset phenomenon due to durability and storage stability are obtained. , Toner fusing in the developing device and toner spent of the carrier are liable to occur, and yellow toner is likely to be blocked.

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.

In the toner of the present invention, the storage elastic modulus at 180 ° C. G ′ ₁₈₀ (frequency 3.14 rad / sec)
c) and the ratio of the minimum storage modulus G ′ _{min (120-170)} within the temperature range of 120 ° C. to 170 ° C. is 2.0 ≦ G ′ ₁₈₀ / G ′ _{min (120-170)} ≦ 8.0 is one of the features. _G'180 / G '
_When the value of _{min (120-170)} is less than 2.0, it means that the rate of increase in viscosity over time due to heating of the resin composition constituting the toner is small. Therefore, it is difficult to apply a shearing force to the yellow colorant at the time of melt-kneading, and it is difficult to reduce the coarse secondary particles of the agglomerated yellow colorant. On the other hand, when the value of G ′ ₁₈₀ / G ′ _{min (120-170)} exceeds 8.0, the elasticity of the yellow toner is too high at the high temperature side, so that the low-temperature fixability at the time of heat and pressure fixing and other factors are low. Tends to decrease the color mixing with the color toner.

G ' ₁₈₀ / G' of yellow toner
One of the preferable means for adjusting the value of _{min (120-170)} to 2.0-8.0 is melt kneading with a polyester resin having an acid value of 2-25 mgKOH / g crosslinked with a polyvalent carboxylic acid. Sometimes, a metal compound of an aromatic carboxylic acid is used as a constituent material of yellow toner particles so that a metal crosslinked structure is newly formed.

The yellow toner of the present invention has a softening point temperature Tm calculated from the flow tester curve of 85 ° C. ≦ T
Preferably, m ≦ 120 ° C.

The softening point temperature Tm of the yellow toner is 120
When the temperature is higher than ℃, although the offset resistance is excellent, the fixing set temperature must be increased, and even if the degree of dispersion of the pigment can be controlled, the surface smoothness in the image area is significantly reduced. It is difficult to achieve high color reproducibility.

When the Tm of the yellow toner is lower than 85 ° C., the smoothness of the surface of the fixed image is high, and although the appearance of the image is vivid, offset tends to occur in the durability of many sheets. Further, the storage stability is poor, and problems such as fusing of the yellow toner in the developing device easily occur. The softening point temperature Tm of the yellow color toner is more preferably 90 ° C. to 115 ° C.

In the present invention, the divalent acid component or ester component for constituting the polyester resin includes terephthalic acid, isophthalic acid, phthalic acid, diphenyl-
P, P'-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane-P, P'-dicarboxylic acid, benzophenone-
Aromatic dicarboxylic acids such as 4,4'-dicarboxylic acid, 1,2-diphenoxyethane-P, P'-dicarboxylic acid, and ester compounds thereof. Other acid or ester components include maleic acid, fumaric acid, glutaric acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid, itaconic acid,
Citraconic acid, sebacic acid, anhydrides and lower alkyl esters of these acids can be used.

As the dihydric alcohol component, the following formula (2)

[0081]

[Outside 4] (Wherein, R ₁ is an alkylene group having 2 to 5 carbon atoms;
X and Y are positive numbers, and include diol compounds represented by 2 ≦ X + Y ≦ 6). G 'of yellow toner
It is preferred ₁₈₀ / G _'min value of _(120-170) for adjusting the 2.0 to 8.0 of R ₁ is an ethylene group.

Other dihydric alcohol components include:
Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,
3-propylene glycol, 1,4-butanediol,
Diols such as neopentyl glycol, 1,4-butenediol; 1,4-bis (hydroxymethyl) cyclohexane, and hydrogenated bisphenol A.

In order to form a crosslinked structure in the polyester resin in advance, the following formula (3)

[0084]

[Outside 5] [In the formula, n is an integer of 3 or more, and R is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. The radicals R are the same or different. It is preferable to use a polycarboxylic acid or an acid anhydride or ester compound thereof as a constituent component of the polyester resin.

Examples of the polycarboxylic acid or ester compound include trimellitic acid, tri-n-ethyl 1,2,4-benzenetricarboxylate, tri-n-butyl 1,2,4-benzenetricarboxylate, Tri-n-hexyl 1,4-benzenetricarboxylate, triisobutyl 1,2,4-benzenetricarboxylate, tri-n-octyl 1,2,4-benzenetricarboxylate, tri-2-ethylhexyl 1,2,4-benzenetricarboxylate , Pyromellitic acid, and tetramethyl ester or tetraethyl ester of 1,2,4,5-benzenetetracarboxylic acid.

In the polyester resin used in the present invention, maleic acid, fumaric acid, glutaric acid, succinic acid, malonic acid, adipic acid having an n-dodecenyl group, an isododecenyl group, an n-dodecyl group, an isododecyl group or an isooctyl group are used. And / or ethylene glycol, 1,3-propylene diol, tetramethylene glycol, or n-dodecenyl group, isododecenyl group, n-dodecyl group, isododecyl group or isooctyl group having an alkyl or alkenyl substituent. , 4-
It is also preferable to use an alcohol having an alkyl substituent or an alkenyl substituent such as butylene diol or 1,5-pentyldiol as a component for constituting a polyester resin.

As a production method for obtaining a polyester resin, for example, the following method can be mentioned.

First, a linear condensate is formed, and in the process, the molecular weight is adjusted so as to be 1.5 to 3 times the target acid value and hydroxyl value, and the molecular weight is made higher than before so that the molecular weight becomes uniform. The condensation reaction proceeds slowly and gradually. For example, (i) the reaction is performed at a lower temperature and for a longer time than before. (Ii) using a monomer having low reactivity, or
(Iii) The esterification reaction is controlled by using these methods in combination. Thereafter, a crosslinking acid component and, if necessary, an alcohol component and / or an acid component are further added and reacted to form a polyester resin. Further raise the temperature, slowly so that the molecular weight distribution becomes uniform,
Let react for a long time, advance the crosslinking reaction, and terminate the reaction when the hydroxyl value or acid value or MI value reaches the target value,
Obtain a polyester resin suitable for the purpose.

The value of G ′ ₁₈₀ / G ′ _{min (120-170)} is 2.0
In order to make the average molecular weight fall within the range of from 8.0 to 8.0, it is preferable that the toner particles contain a metal compound of aromatic carboxylic acid. Glass transition temperature is 50-65 ° C and acid value is 2
A formula (1) wherein the average value of the ratio of the major axis to the minor axis of the polyester resin of the primary resin and the primary particle is from 1.5 to 25 mgKOH / g, and the number average particle diameter of the primary particle is from 0.1 to 0.7 μm. When the yellow colorant shown in 1) and the metal compound of the aromatic carboxylic acid are melt-kneaded, a metal cross-linked structure is partially formed in the polyester resin during the melt-kneading, and the viscosity of the kneaded material gradually increases during the kneading. . Therefore, the melt viscosity of the kneaded material is significantly higher than the melt viscosity of the binder resin alone. Therefore, since the primary particles of the yellow colorant are fine, the self-cohesive force is strong, and even if coarse secondary particles of the yellow colorant are present, the coarse secondary particles due to sufficient shearing force generated during melt-kneading are Primary particles and / or
Or it is crushed into fine secondary particles. As a result, it is possible to efficiently produce a melt-kneaded material in which primary particles and fine secondary particles of the yellow colorant are uniformly dispersed.

Although details are unknown, the site of the imino group in the yellow colorant represented by the formula (1) and the site of the carbonyl group of the carboxylic acid group in the polyester resin are partially hydrogen bonded or static. The bonding by the electric interaction further enhances the dispersibility of the yellow colorant in the polyester resin, and suppresses the adsorption of moisture to the ester bond in the molecular chain of the polyester resin, thereby increasing the temperature of the yellow toner. It is presumed that a decrease in the charge amount in a humid environment can be suppressed. The metal compound of the aromatic carboxylic acid also functions as a negative charge control agent for improving and stabilizing the negative triboelectric charging property of the yellow toner.

Preferred aromatic carboxylic acids for forming the metal compound include salicylic acid, monoalkyl salicylic acid and dialkyl salicylic acid. Especially,
Dialkyl salicylic acid is preferred, and among them, di-tert
-Butylsalicylic acid is particularly preferred.

As the metal compound of the aromatic carboxylic acid,
Salicylic acid metal salt, salicylic acid metal complex, alkyl salicylic acid metal salt, alkyl salicylic acid metal complex,
Examples thereof include metal salts of dialkylsalicylic acid and metal complexes of dialkylsalicylic acid.

In the present invention, the metal element of the metal compound of the aromatic carboxylic acid is preferably aluminum. Aluminum compounds are preferred over metal compounds such as zinc because the crosslinking reaction with the polyester resin during kneading proceeds easily.

When the metal compound of the aromatic carboxylic acid is contained in the yellow toner particles, the content thereof is as follows.
It is 2 to 10 parts by weight, more preferably 3 to 8 parts by weight, per 100 parts by weight of the binder resin. When the amount of the metal compound of the aromatic carboxylic acid is 2 to 10 parts by weight, the crosslinking reaction with the polyester resin proceeds well during melt-kneading, and the yellow colorant is finely and uniformly dispersed in the polyester resin. This is preferable because the negative frictional charging property of the yellow toner is adjusted to a suitable range. When the amount of the metal compound of the aromatic carboxylic acid is less than 2 parts by weight, the amount of the crosslinked metal of the polyester resin is small and the melt viscosity does not increase, or even if it increases, the rate of increase is small, and the negative charge control effect of the yellow toner is small. If the amount of the metal compound of the aromatic carboxylic acid is more than 10 parts by weight, the crosslinked portion of the metal of the polyester resin becomes too large, and the low-temperature fixability of the yellow toner and the color mixing with other color toners are reduced. Further, under low temperature and low humidity, the yellow toner is easily charged up.

The yellow toner of the present invention causes a cross-linking reaction by an interaction between a specific polyester resin and a metal compound of an aromatic carboxylic acid, thereby increasing the share of secondary particles of the yellow colorant during kneading. The yellow colorant is finely and evenly dispersed, and is excellent in quick melting property even at low temperature during heating and pressing fixation, and exhibits elastic properties strongly at high temperature, causing offset. This is a yellow toner designed to be difficult to perform. In the yellow toner of the present invention, if necessary, a fatty acid metal salt (eg, zinc stearate, aluminum stearate), a fluorine-containing polymer fine powder (eg, polytetrafluoroethylene, polyvinylidene fluoride, An ethylene-vinylidene fluoride copolymer fine powder) or a conductivity imparting agent such as tin oxide and zinc oxide may be added.

Further, in the present invention, a release agent may be contained in the yellow toner particles. For example, aliphatic hydrocarbon wax, an aliphatic hydrocarbon wax oxide, an ester wax, a wax composition mainly containing a fatty acid ester, a saturated linear fatty acid, an unsaturated fatty acid, a saturated alcohol, and a polyhydric alcohol at room temperature. Alcohols, fatty acid amides,
Examples include saturated fatty acid bisamides, unsaturated fatty acid amides, and aromatic bisamides.

The content of the release agent in the yellow toner particles is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin.

[0098] When the content of the release agent exceeds 20 parts by weight, the 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 low. .

These release agents are usually prepared by dissolving the resin in a solvent, raising the temperature of the resin solution, adding the release agent and adding the mixture to the binder resin in advance with stirring, or the toner constituent material during kneading. And a method in which the mixture is mixed with a release agent and contained in the toner particles.

The method for producing yellow toner particles according to the present invention is as follows. A binder resin, a yellow colorant, a metal compound of an aromatic carboxylic acid, and other additives are added and uniformly mixed by a mixer such as a Henschel mixer. Thereafter, the mixture is melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder, and is mutually compatible and dispersed. After cooling and solidifying, pulverization and strict classification are performed to produce yellow toner particles having a desired viscosity. Method. The melt-kneading temperature is preferably from 120 to 170C.

In the present invention, after the yellow colorant is added to a part of the binder resin in advance and dispersed, the above dispersion is mixed with the remaining binder resin, the metal compound of aromatic carboxylic acid, and further, if necessary. If necessary, other additives may be added, and thereafter, melt kneading, cooling, pulverization, and classification may be performed. Examples of the step of dispersing the yellow colorant in the binder resin in advance include a conventionally known master batch method and a flushing method.

In the present invention, the weight average particle size of the yellow toner particles is preferably 3 to 15 μm, more preferably 4 to 12 μm, and most preferably 4 to 8 μm.

The weight average particle size of the yellow toner particles is 3 μm.
When it is less than m, it becomes difficult to stabilize charging,
In multi-sheet durability, fog and toner scattering in the image forming apparatus are likely to occur.

The weight average particle size of the yellow toner particles is 15
If it exceeds μm, the reproducibility of the halftone portion is reduced, and the resulting image tends to be rough.

In the yellow toner of the present invention, a hydrophobicity-imparted titanium oxide fine powder or a hydrophobized aluminum oxide having an average primary particle diameter of 0.005 to 0.1 μm is used as a fluidity improver for the yellow toner particles. It is better to externally add fine powder.

An important factor in the fluidity improver as an external additive is to increase the fluidity of the yellow toner and not to impair the chargeability of the yellow toner.

Accordingly, the surface of the titanium oxide fine powder or the aluminum oxide fine powder is preferably subjected to a hydrophobic treatment, whereby it is possible to simultaneously impart fluidity and stabilize charging.

Since the titanium oxide fine powder or the aluminum oxide fine powder has been subjected to a hydrophobic treatment, the influence of water, which is a factor that affects the charge amount, is excluded, and the difference in the charge amount between high and low humidity conditions. , The environmental characteristics of the yellow toner can be improved. Furthermore, it becomes possible to break up the aggregation of the primary particles during the hydrophobizing treatment step, and the external additive with less secondary aggregation can apply a uniform charge to the yellow toner.

In the present invention, in particular, titanium oxide fine powder or alumina fine powder having an average primary particle diameter of 0.005 to 0.1 μm has a good fluidity and the negatively charged yellow toner is uniformly charged. It is preferable because scattering and fogging hardly occur. Further, the toner is hardly embedded on the surface of the yellow toner particles, and the toner is hardly deteriorated.
Multi-sheet durability is improved. This tendency is more remarkable in a yellow toner having sharp melt properties.

When the average primary particle diameter of the titanium oxide fine powder or the aluminum oxide fine powder is less than 0.005 μm, the treated fine powder is easily embedded on the surface of the yellow color toner particles, and the toner is apt to deteriorate quickly. The durability tends to decrease. This tendency is more remarkable than when applied to a yellow toner having sharp melt properties.

When the thickness exceeds 0.1 μm, the fluidity of the yellow toner is low and the charging of the yellow toner is likely to be non-uniform. As a result, the resolution is reduced, the toner is scattered and fog is liable to occur. It becomes difficult to generate a high quality toner image.

In the yellow toner of the present invention, the addition amount of the titanium oxide fine powder or the aluminum oxide fine powder is
Preferably, the amount is 0.1 to 100 parts by weight of the yellow toner particles.
5 to 5.0 parts by weight, more preferably 0.7 to 3.0 parts by weight, even more preferably 1.0 to 2.5 parts by weight. The yellow toner that satisfies the above range has good fluidity, can maintain a stable charge amount, and hardly causes toner scattering.

When the yellow toner of the present invention is used in a two-component developer, the carrier used may be, for example, a metal such as iron, nickel, copper, zinc, cobalt, manganese, chromium, or a rare earth element, which has been oxidized or not oxidized. Particles and their magnetic alloy or magnetic oxide particles and magnetic ferrite particles.

When the carrier is a coated carrier obtained by coating a carrier core with a coating material, a method for coating the surface of the carrier core with the coating material is to dissolve or suspend the coating material in a solvent, apply the coating material, and adhere to the carrier core. How to make
A method of simply mixing in a powder state can be applied.

Examples of the coating material for the carrier core include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. No. These may be used alone or in combination.

The amount of the material to be treated may be determined as appropriate, but is generally 0.01 to 5% by weight, preferably 0.05 to 3% by weight, based on the carrier in total amount.
Most preferably, it is 0.10 to 2% by weight.

The carrier preferably has an average particle size of 10 to 10.
The thickness is preferably 100 μm, more preferably 20 to 80 μm.

As a particularly preferred carrier, the surface of a magnetic core particle such as a magnetic ferrite core particle is coated with a resin such as a silicone resin, a fluorine resin, a styrene resin, an acrylic resin and a methacrylate resin in an amount of 0.01 to 5% by weight. Preferably, a resin-coated magnetic carrier coated with 0.05 to 3% by weight and having the above average particle size of 70% by weight or more of carrier particles of 250 mesh pass and 400 mesh on is included.

When the particle size distribution of the resin-coated magnetic carrier is sharp, triboelectrification to the yellow toner of the present invention is preferable, and the effect of improving electrophotographic properties is obtained.

When a two-component developer is prepared by mixing a yellow toner and a carrier, 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 density is less than 2% by weight, the image density tends to be low.
If the content is more than 1% by weight, fogging and scattering in the machine tend to occur, and the useful life of the developer tends to be shortened.

Next, the yellow toner of the present invention is applied,
FIG. 3 shows a method for forming a full-color image by electrophotography.
This will be described with reference to FIG.

FIG. 3 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. 3 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. 3, the digital color image reader is provided, and a digital color image printer is provided below.

In the image reader section, the original 30 is placed on the original platen glass 31 and is exposed and scanned by the exposure lamp 32, so that the reflected light image from the original 30 is condensed on the full color sensor 34 by the lens 33 and the color image is reflected. 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, the photosensitive drum 1, which is an electrostatic image carrier, has a photosensitive layer having, for example, an organic photoconductor, and is rotatably carried 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.

At the time of image formation, the printer unit
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 separation color, and the electrostatic charge 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 by, for example, a reversal developing method, thereby forming a toner image on the photosensitive drum 1 with toner. The developing devices 4Y, 4C, 4M, and 4K are provided with respective eccentric cams 2.
By the operations of 4Y, 24C, 24M, and 24K, development is performed by selectively approaching the photosensitive drum 1 according to each separation color.

The transfer device includes a transfer drum 5a, a transfer charger 5b, a suction charger 5c for electrostatically attracting a transfer paper or an OHP sheet as a transfer material, a suction roller 5g opposed thereto, and an inner charger 5d. , The outer charger 5e,
It has a separation 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 with the rotation of the transfer drum 5a, and is transferred onto the transfer material by the action of the transfer charger 5b while passing through the transfer position. Is transferred onto the photosensitive drum 1.

As shown in FIG. 3, the toner image may be directly transferred from the photoconductor to the transfer material, or the toner image on the photoconductor may be transferred to the intermediate transfer member, and the toner image may be transferred from the intermediate transfer member. It may be transferred to a material.

[0131] The above image forming step 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 deposited on the transfer sheet 5f. Such cleaning is performed before or after image formation, and at any time when a jam, that is, a paper jam occurs.

The gap between the transfer sheet 5f and the processing 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. And 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.

The image forming apparatus forms a full-color image. 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.

Next, the method of measuring each physical property will be described below.

Measurement of Rheological Properties of Yellow Toner A toner is molded under pressure into a disk-shaped sample having a diameter of about 40 mm and a thickness of about 2 mm. Next, set it on the parallel plate,
The temperature is gradually increased within a temperature range of 0 to 200 ° C., and the temperature dispersion is measured. The heating rate was 10 ° C./min. The angular frequency (ω) is fixed at 3.14 rad / sec, and the distortion factor is automatic. Taking the temperature on the horizontal axis and G 'on the vertical axis, the value at each temperature is read. In the measurement, for example, RDA-I
I (manufactured by Rheometrics) is used.

The number average particle diameter and the long diameter of the yellow colorant
Measurement of the ratio of minor axis The major axis and minor axis of the primary particles of the yellow pigment particles constituting the yellow colorant are magnified 30,000 to 50,000 times in the visual field by observing the yellow pigment particles themselves with a scanning electron microscope. Measure the length of 300 pigment particles of 0.1μm or more,
The ratio of the average value is taken as the ratio of the major axis to the minor axis.

The number average particle size of the yellow colorant is the average value of the major diameters of the primary particles of the yellow pigment particles.

The value of the number average particle diameter and the ratio of the major axis to the minor axis of the yellow colorant can be measured from the yellow colorant in the yellow toner particles described later, and there is no substantial difference in the measured values.

The yellow colorant in the yellow toner particles
Adding yellow toner or a yellow toner particles to sucrose solution particle size measurement 2.3M, dipped well stirred small amount of this sample holder pin, then allowed to put solidified in liquid N _2, immediately set in the sample arm head I do.

A sample is prepared by cutting with an ultramicrotome FC4E equipped with a cryo device (manufactured by Nissan Sangyo) according to a conventional method.

Using an electron microscope H-8000 (manufactured by Hitachi, Ltd.), a photograph was taken at an acceleration voltage of 100 kV. The magnification is 30,000 to 50,000 times.

The image information is introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, and
Convert to value image data. Of these, only the pigment particles having a primary particle size and a secondary particle size of 0.1 μm or more are analyzed at random, and the number of samples is 30
The measurement is repeated until the number of times exceeds 0, and the number average particle diameter of the pigment particles, the particle size distribution, and the ratio of the major axis to the minor axis are determined.

Here, only the primary and secondary particles of the yellow colorant larger than 0.1 μm are measured.
Particle size referred to in the present invention, measuring the area of each pigment particle image,
The diameter of a circle having the same area as the area is defined as the particle diameter of each pigment particle.

Measurement of Toner Particles and Particle Size Distribution of Toner A Coulter Counter TA-II or a 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, ISTON R-
II (manufactured by Coulter Scientific Japan)
Can be used. The measuring method is as follows.
0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) as a dispersant is added to 0 to 150 ml, and 2 to 20 mg of a measurement sample is further added. 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 an m aperture, the particle size is between 2.00 and 40.30.
The volume and the number of μm toner particles are measured for each channel, and the volume distribution and the number distribution of the toner are calculated. Then, the weight average particle diameter (D4) of the toner particles on a weight basis (the median value of each channel is set as a representative value for each channel) is determined from the volume distribution of the toner particles.

The particles externally added to the toner particles as an external additive have very few particles having a particle size of 2.00 μm or more. Therefore, even when the toner having the external additive is measured, the weight average particle size (D4 ) Has been confirmed to exhibit substantially the same value as the weight average particle size (D ₄ ) of the toner particles.

As channels, 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.

Method for Measuring Acid Value A 2 to 10 g sample is weighed in a 200 to 300 ml Erlenmeyer flask, and about 50 ml of a mixed solvent of methanol: toluene = 30: 70 is added to dissolve the polyester resin.
If the solubility is poor, a small amount of acetone may be added. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titrate with a pre-specified alcoholic solution of 0.1N potassium hydroxide, and calculate the acid value from the consumption of the potassium alcohol solution by the following calculation. .

Acid value = [KOH (ml number) × N × 56.1] / weight of sample (where N is a factor of a 0.1 N KOH solution)

[0151] Measurement method 4 of triboelectric charge is an illustration of an apparatus for measuring a triboelectric charge quantity. Approximately 0.5 to 1.5 g of the developer collected from above the developing sleeve of the copier or printer is placed in a metal measuring container 52 having a 500-mesh screen 53 at the bottom, and a metal lid 54 is provided. At this time, the weight of the entire measurement container 52 is weighed and W
₁ (g). Next, in the suction device 51 (at least the portion in contact with the measurement container 52 is at least an insulator), the air is suctioned from the suction port 57 to prepare the air volume control valve 56 to reduce the pressure of the vacuum gauge 55 to 2
50 mmAq. In this state, suction is sufficiently performed, preferably for 2 minutes, to remove the toner by suction. Electrometer 5 at this time
It is assumed that the potential V is 9 (volts). Here, 58 is a capacitor whose capacity is C (mF). Further, the weight of the whole measurement container after suction is weighed to be W ₂ (g). The triboelectric charge (mC / kg) of this sample is calculated as shown below.

Amount of triboelectric charge of sample (mC / kg) = C × V
/ (W ₁ -W ₂ )

The fine particles of titanium oxide fine particles and alumina fine particles
Measurement method of uniform particle diameter The primary particle diameter was measured by observing titanium oxide fine particles and alumina fine particles with a transmission electron microscope, and measuring 300 particle diameters of 0.005 μm or more in a visual field of 30,000 to 50,000 times. Obtain the average particle diameter by using a scanning electron microscope. The particle diameter of the dispersed particles on the toner particles is quantified by XMA with 300 titanium fine particles and alumina fine particles magnified 30,000 to 50,000 times in the visual field. Is measured to determine the average particle size.

Measurement of glass transition temperature Tg Differential thermal analysis measurement device (DSC measurement device), for example, DSC
-7 (manufactured by PerkinElmer).

The measurement sample is 5 to 20 mg, preferably 10
Weigh the mg precisely.

This was put in an aluminum pan, and an empty aluminum pan was used as a reference.
The measurement is performed at a temperature rising rate of 10 ° C./min under normal temperature and normal humidity between 00 ° C.

In this heating process, an endothermic peak of a main peak in a temperature range of 40 to 100 ° C. is obtained.

The intersection between the line of the midpoint of the baseline and the differential heat curve before and after the endothermic peak at this time is expressed by:
The glass transition temperature is Tg.

Measurement of Softening Point Temperature of Resin or Toner A flow tester CFT-500 type (manufactured by Shimadzu Corporation) is used. The sample weighs about 1.0 g of a 60 mesh pass product. This is pressurized with a load of 100 kg / cm ² for 1 minute using a molding machine.

The pressurized sample is subjected to a flow tester measurement under the following conditions under normal temperature and normal humidity (temperature: about 20 to 30 ° C., humidity: 30 to 70% RH) to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the temperature (= T _1/2 ) at the time when the sample flows out by 50% by volume is determined, and this is defined as the softening point temperature Tm of the resin or toner.

RATE TEMP 6.0 (° C./min) SET TEMP 50.0 (° C.) MAX TEMP 180.0 (° C.) INTERVAL 3.0 (° C.) PREHEAT 300.0 (second) LOAD 10.0 (kg) DTE (Diameter) 1.0 (mm) DIE (Length) 1.0 (mm) PLUNGER 1.0 (cm ² )

Method for Measuring Molecular Weight of Polyester Resin Mn, Mw and Mw / Mn of the polyester resin are measured by gel permeation chromatography (GPC). The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) was passed through the column at this temperature as a solvent at a flow rate of 1 ml / min.
Measure by injecting 100 μl of HF sample solvent. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As the standard polystyrene samples for preparing the calibration curve, for example, manufactured by Tosoh Corporation or molecular weight of Showa Denko KK is 10 ² to 10
^It is appropriate to use about ⁷ samples and at least about 10 standard polystyrene samples. The detector has R1
A (refractive index) detector is used. As the column, a combination of a plurality of commercially available polystyrene gel columns is preferably used.

For example, Shodex G manufactured by Showa Denko KK
PC KF-801,802,803,804,80
5,806,807,800P, TSKgel G1000H (H _XL ), G2000
H (H _XL ), G3000H (H _XL ), G4000H (H
_{XL), G5000H (H XL)} , G6000H (H XL),
G7000H (H _XL ), TSKguardcolumn
Can be cited.

The sample is prepared as follows.

After placing the sample in THF and leaving it to stand for several hours, it is shaken well, mixed well with THF (until the sample is no longer united), and left still for 12 hours or more. Then T
The time of leaving in HF is set to 24 hours or more.
After that, the sample processing filter (pore size 0.45
０．５0.5 μm, for example, Myshodisk H-25-
5 Tosoh Co., Ltd., Exiclo Disc 25CR, Germanic,
(A product of Science Japan Co., Ltd.) can be used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

Measurement Method of BET Specific Surface Area The BET specific surface area of the pigment was measured by Yuasa Ionics Co., Ltd.
Fully automatic gas adsorption amount measuring device: using Auto Soap 1,
It is determined by the BET multipoint method using nitrogen as the adsorption gas. In addition, as pretreatment of a sample, deaeration is performed at a temperature of 50 ° C. for 10 hours.

Method for Measuring Average Particle Size of Carrier Using a Microtrac particle size analyzer SRA type (manufactured by Nikkiso Co., Ltd.), the carrier was measured at 0.7 to 700 μm.
The measurement is performed with the range setting of
In the present invention, the% particle size is defined as the average particle size of the carrier.

[0168]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 Polyester Resin No. 170 parts by weight [A crosslinked polyester resin synthesized from polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane, terephthalic acid, fumaric acid and trimellitic acid (acid value 10.5 mgKOH / g, Tg = 56 ° C, Mn =
4000, Mw = 9000, Tm = 90 ° C.)] ・ Yellow pigment represented by the following structural formula (number-average diameter: 0.
25 μm, ratio of major axis to minor axis 1.4, BET specific surface area 6
2m ² / g) 30 parts by weight

[0170]

[Outside 6]

The above materials were charged into a kneader type mixer,
While mixing, the temperature was raised under no pressure, and the mixture was sufficiently premixed.
Thereafter, the mixture was kneaded twice with three rolls to obtain a first kneaded material.

The first kneaded product (pigment particle content 3
0% by weight) 16.7 parts by weight Polyester resin No. 188.3 parts by weight-Aluminum compound of di-tert-butylsalicylic acid 4 parts by weight The above materials are sufficiently premixed by a Henschel mixer, melt-kneaded at a temperature of 125 to 130 ° C by a twin-screw extruder, and cooled. It was roughly pulverized about 1 to 2 mm using a hammer mill, and then finely pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized material is strictly removed at the same time by a multi-segmentation classifier to remove fine powder and coarse powder at the same time.
m yellow toner particles were obtained.

On the other hand, hydrophilic titanium oxide fine powder (primary average particle size 0.02
μm, BET specific surface area: 140 m ² / g) 100 parts by weight of nC ₄ H ₉ —Si (OCH ₃ ) ₃ and 20 parts by weight of a surface treatment to obtain a primary average particle diameter of 0.02 μm.
A hydrophobic titanium oxide fine powder A having a degree of hydrophobicity of 70% was obtained.

A mixture of 100 parts by weight of yellow toner particles and 1.5 parts by weight of hydrophobic titanium oxide fine powder A was mixed with yellow toner No. 1 having hydrophobic titanium oxide fine particles on the surface of the yellow toner particles. 1 was prepared.

The yellow toner No. _G'180 / G 'of 1
_{min (120-170)} is 3.1, yellow toner No. The softening point of No. 1 is 97 ° C., the number average particle diameter including primary particles and secondary particles as independent particles of the yellow pigment in the yellow toner particles is 0.38 μm, and the particle diameter is 0.1 to 0.5 μm.
The content ratio of m yellow pigment particles is 78% by number,
The content ratio of the yellow pigment having a particle size of 0.8 μm was 1.2% by number. Yellow toner No. FIG. 1 shows a graph of G 'of FIG.

The yellow toner no. No. 1 and magnetic ferrite carrier particles (average particle size: 40 μm) surface-coated with a silicone resin were mixed so that the toner concentration became 6% by weight to obtain a two-component yellow developer.

The above two-component yellow developer was introduced into a commercially available plain paper full-color copying machine (color laser copying machine CLC700, manufactured by Canon Inc.) having a heat and pressure fixing device, and a copying test was conducted at a fixing temperature of 170 ° C. Even in a durability test of 50,000 sheets in a normal temperature and normal humidity environment (temperature 23 ° C., humidity 60% RH), the image density shows a high image density of 1.7 to 1.8, and there is little initial fluctuation in charging characteristics. -22mC
/ Kg to -25 mC / kg.

After the endurance of 50,000 sheets, the surface of the OPC photosensitive drum is
No filming due to fusion of the toner was observed, and no cleaning failure occurred during this time.

No offset to the heating (fixing) roller occurred at all even in 50,000-sheet durability copying. The surface of the heat roller after the endurance was visually observed, and there was no contamination by the yellow toner.

When the surface of the carrier in the developer after 50,000 sheets of durability was observed by SEM, almost no toner spent was observed.

Further, in a high temperature and high humidity environment (30 ° C., 80%)
A durability test was performed on 50,000 sheets under a low-temperature and low-humidity environment (15 ° C., 10%), but no fog or scattering occurred, and the image density remained almost stable.

Next, cyan toner particles having a weight average diameter of 6.5 μm were substantially the same except that 4 parts by weight of a cyan pigment (CI Pigment Blue 15: 3) was used instead of the yellow pigment. I got

Further, magenta pigment (CI Pigment Red 122) was used instead of the yellow pigment.
Magenta toner particles having a weight average diameter of 6.3 μm were obtained in substantially the same manner except that parts by weight were used.

With respect to 100 parts by weight of the obtained cyan toner particles and 100 parts by weight of magenta toner particles, the yellow toner No. In the same manner as in Example 1, the hydrophobic titanium oxide fine powder A
1.5 parts by weight were mixed to obtain a cyan toner and a magenta toner each having the hydrophobic titanium oxide fine particles A on the particle surface, and thereafter, a two-component cyan developer and a two-component magenta developer were similarly obtained. Was prepared.

The amount of toner on the unfixed transfer material is 0.8% for the yellow toner, magenta toner and cyan toner.
The contrast potential of the main body was adjusted so as to be mg / cm ² , and a green solid image was output with the yellow toner and the cyan toner, and a red solid image was output with the yellow toner and the magenta toner.

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 and the chromaticity of the image. The higher the gross value, the smoother the surface of the image and the more lustrous saturation (C ^* )
Color quality is high, and if the gloss value is low,
It is determined that the image surface with poor dull saturation (C ^* ) is rough. Note that “C ^* ” is calculated from the values of a ^* and b ^* measured by the following method using the following formula.

[0187]

[Outside 7] The larger the C ^* , the brighter the image.

For measurement of gloss (gloss), a VG-10 type gloss meter manufactured by Nippon Denshoku Co., Ltd. was used. When measuring,
First, set the voltage to 6 V with a constant voltage device, then adjust the light projection angle and the light reception angle to 60 °, respectively, adjust the zero point and use a standard plate.
The samples were stacked, and the sample image was further placed thereon, and the numerical values indicated in the markings were read in units of%.

The color tone of the toner was quantitatively measured based on the definition of the color system standardized by the International Commission on Illumination (CIE) in 1976. That is, a ^* and b ^* (a ^* and b ^* are chromaticities indicating hue and saturation) and L ^* (brightness) were 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 °.

The gloss and chromaticity of each image in Example 1 are as shown in Table 1 below.

[0191]

[Table 1]

According to the yellow toner No. of the present invention, When using No. 1, the images of green and red, which are the secondary colors, also had high brightness and saturation.

Further, the transparency film on which a color image was formed using the transparency film as a transfer material was transferred to an overhead projector (OH
The transparency of the OHP image projected on P) was also good.

The transparency of the OHP image in the above embodiment was evaluated based on the following evaluation criteria by projecting a color image formed with the above-mentioned yellow toner on a transparency film using a commercially available overhead projector. did.

Evaluation criteria A: excellent in transparency, no unevenness in brightness and darkness, and excellent in 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. (bad)

When the light fastness of the obtained solid yellow image (image density 1.70) was confirmed substantially according to JIS K7102, the image density after light irradiation for 400 hours was almost the same as the initial image density (1.70). 63), and ΔE is 3.
6, and the hue change was only slight. A carbon arc lamp was used as a light source.

The change in hue was determined by calculating the ΔE value of the following formula, and quantitatively evaluating it based on the following light resistance evaluation criteria.

ΔE = ｛(L ₁ ^* −L ₂ ^* ) ² + (a ₁ ^*
−a ₂ ^* ) ² + (b ₁ ^* −b ₂ ^* ) ² ｝ ^1/2 L ₁ ^* : brightness of image before light irradiation a ₁ ^* , b ₁ ^* : hue and saturation of image before light irradiation L ₂ ^* : lightness of image after light irradiation a ₂ ^* , b ₂ ^* : chromaticity indicating hue and saturation of image after light irradiation

Evaluation standard of light resistance A: No fading even after irradiation for 400 hours. B: Does not fade even after irradiation for 200 hours. C: Discolored after irradiation for 100 hours.

Comparative Example 1 Comparative Example 1 was carried out in the same manner as in Example 1 except that the aluminum compound of di-tert-butylsalicylic acid was not used. 1 was obtained. Comparative Yellow Toner No. 1 of _{G '180 / G' min (} 120-170)
Was 0.75 and the softening point was 91 ° C. Comparative Yellow Toner No. FIG. 2 shows a graph of G ′ of FIG.

When the durability was evaluated in the same manner as in Example 1, in the durability under a low-temperature and low-humidity environment, the image density was reduced from about the 3000th sheet, and fogging began to occur slightly.

In a high-temperature, high-humidity environment, comparative yellow toner The charge amount of No. 1 decreased, and the image density increased accordingly, and some scattering and fogging began to occur.

In the endurance performed in a normal temperature and normal humidity environment, a part of offset occurred around the 5000th sheet. When the endurance was stopped and the fixing roller was examined, the fixing roller was contaminated with toner. I was

Comparative Yellow Toner No. The gloss and chromaticity of the image No. 1 were examined in the same manner as in Example 1. The results are shown in Tables 2 and 3.

Comparative Yellow Toner No. No. 1 has lower lightness and chroma than the toner of Example 1 despite the fact that the gloss of the image is higher under the same fixing conditions because the softening point of the toner is lower. It is thought to be due to the badness of the.

The transparency of the actual OHP image was not always good.

Comparative Example 2 The polyester resin No. used in Example 1 Polyester resin No. 1 2 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) non-crosslinked polyester resin synthesized from propane and fumaric acid (acid value 12 mgKOH / g,
Tg = 56 ° C., Mn = 4000, Mw = 11000, T
m = 90 ° C.)], except that Comparative Yellow Toner No. 2 was obtained. G ′ ₁₈₀ / G ′ _{min (120-170)} of the yellow toner 5 is 0.98,
The softening point was 93 ° C.

Although no particular problem occurred in the durability under normal temperature and normal humidity environment, the charge amount of the toner decreased and fog occurred during the durability under high temperature and high humidity environment. When the fixing roller after 20,000 sheets of durability was examined, it was found that the fixing roller was contaminated with yellow toner. The results are shown in Tables 2 and 3.

Comparative Example 3 Polyester resin No. 1 used in Example 1 Polyester resin No. 1 3 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid, and crosslinked polyester resin synthesized from trimellitic acid (acid value 15 mgKOH / g, Tg = 59 ° C, Mn = 5
600, Mw = 22000, Tm = 98 ° C.)] and using 8 parts by weight of an aluminum compound of di-tert-butylsalicylic acid in the same manner as in Example 1 except that Comparative Yellow Toner No. 3 was obtained. Comparative Yellow Toner No. 3 of _{G '180 / G' min (} 120-170)
Was 8.8 and the softening point was 116 ° C.

Although the initial image had low gloss as a whole, it had no fog and had good reproducibility of highlights.
However, when images were imaged in a low-temperature and low-humidity environment, cold offset occurred on the 30th sheet, and durability was interrupted. More OHP
The transparency of the image was also never good.

Comparative Yellow Toner No. The image No. 3 was examined for gloss and chromaticity in the same manner as in Example 1. The results are shown in Tables 2 and 3.

Comparative Yellow Toner No. No. 3 is the yellow toner No. of Example 1. As compared with Example 1, the gloss of the image was low under the same fixing conditions because the softening point of the toner was high, and the lightness and chroma were lower than those in Example 1, and a bright yellow image was not obtained. .

Comparative Example 4 Polyester resin No. 1 used in Example 1 1. Styrene / acrylic resin [copolymer of styrene and n-butyl acrylate (substantially zero acid value, Tg = 60 ° C., Mn = 4800, Mw =
15000, Tm = 96 ° C.)
In the same manner as in Example 1, the comparative yellow toner No. 4 was obtained. Comparative Yellow Toner No. The gloss and chromaticity of the image No. 4 were examined in the same manner as in Example 1. The results are shown in Tables 2 and 3.

Comparative Yellow Toner No. In No. 4, both lightness and chroma were lower than those in Example 1.

Further, the comparative yellow toner no. 4 was used in a low-temperature and low-humidity environment. As a result, the charge amount increased and the image density became low.

Comparative Example 5 C.I. having a number average particle diameter of primary particles of 0.38 μm, a ratio of major axis to minor axis of 1.8, and a specific surface area of 39 m ² / g. I. Pigment 180, except that Pigment 180 was used.
o. 5 was prepared. Comparative Yellow Toner No. G 'of 5
₁₈₀ / _{G'min (120-170)} is 2.8, and the comparative yellow toner No. The softening point of No. 5 is 96 ° C., the number average particle diameter including primary particles and secondary particles as independent particles of the yellow pigment in the yellow toner particles is 0.58 μm, and the particle diameter is 0.1 to 0.5 μm. The content ratio of the yellow pigment particles was 38% by number, and the content ratio of the yellow pigment having a particle size of 0.8 μm was 8% by number. Comparative Yellow Toner No.
The gloss and chromaticity of No. 5 were examined in the same manner as in the example. Table 2 shows the results
And Table 3.

Comparative Yellow Toner No. In No. 5, both lightness and chroma were lower than in Example 1. Comparative Yellow Toner No. 5 and the cyan toner generated in Example 1, a solid green image was formed in the same manner as in Example 1. The gloss was 27%, L ^* was 44, and a ^* was -52. , B ^* was 17, and the saturation of the green solid image was low.

Further, Comparative Yellow Toner No. 5 was used in a low-temperature and low-humidity environment. As a result, the charge amount increased and the image density was low.

Comparative Example 6 The following formula (4) was used in place of the coloring agent used in Example 1.

[0220]

[Outside 8] The yellow colorant of compound (4) (CIP
Comparative Yellow Toner No. 7 in the same manner as in Example 1 except that 7 parts by weight of the yellow toner 74) was used per 100 parts by weight of the polyester resin. 6
And evaluated in the same manner as in Example 1. From the point of time of about 5,000 sheets under the high temperature and high humidity environment, the comparative yellow toner No. The endurance was suspended because the charge amount of No. 6 began to decrease and fog began to be noticeable.

The compound (4) has a lower coloring power than the compound (1) used in Example 1, and in order to obtain an image with a high image density, the contrast potential of a full-color copying machine must be adjusted. It had to be higher than in Example 1. The results are shown in Tables 2 and 3.

Comparative Example 7 The following formula (5) was used in place of the yellow colorant used in Example 1.

[0223]

[Outside 9] The yellow colorant of compound (5) (CIP
Comparative Yellow Toner No. 12 in the same manner as in Example 1 except that 5 parts by weight of CI Pigment Yellow 12) was used per 100 parts by weight of the polyester resin. 7
Was prepared and evaluated in the same manner as in Example 1. Although the durability changed relatively stably under each environment, the obtained yellow image was subjected to a light resistance acceleration test of carbon arc lamp irradiation, and ΔE was 12 after 100 hours of light irradiation,
Apparent discoloration occurred.

Example 2 The polyester resin No. used in Example 1 Instead of 1,
Polyester resin No. 4 [polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl)
Crosslinked polyester resin synthesized from propane, terephthalic acid, fumaric acid and trimellitic acid (acid value 2.4mg
KOH / g, Tg = 59 ° C., Mn = 4200, Mw = 1
2000, Tm = 95 ° C.)]
In the same manner as in Example 1, the yellow toner No. 2 was obtained. Evaluation was performed in the same manner as in Example 1. As a result, the image density began to decrease from around the 20,000th sheet due to durability in a low-temperature and low-humidity environment, but was within a practical level.

The yellow toner No. 2 G ' ₁₈₀ / G'
_{The min (120-170)} was 2.1 and the softening point was 100 ° C. The results are shown in Tables 2 and 3.

Example 3 The polyester resin No. used in Example 1 Instead of 1,
Polyester resin No. 5 [polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl)
Crosslinked polyester resin synthesized from propane, terephthalic acid, fumaric acid and trimellitic acid (acid value 24.2m
gKOH / g, Tg = 54 ° C., Mn = 4800, Mw =
11000, Tm = 92 ° C.) except that yellow toner No. 1 is used. 3 was obtained. Evaluation was made in the same manner as in Example 1. As a result, although the charge amount was slightly reduced in a high-temperature and high-humidity environment, no problem occurred on the image.

The yellow toner No. _G'180 / G 'of 3
_{The min (120-170)} was 3.4 and the softening point was 99 ° C. The results are shown in Tables 2 and 3.

Example 4 Instead of the hydrophobic titanium oxide fine powder A used in Example 1,
Hydrophilic alumina fine powder (primary average particle size: 0.02μ)
m, BET specific surface area: 130 m ² / g) 100 parts by weight, and 17 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ were used for surface treatment. Primary average particle size 0.02μ
m, and a yellow toner No. 1 in the same manner as in Example 1 except that hydrophobic alumina fine powder A having a hydrophobicity of 70% was used. 4 was prepared and evaluated in the same manner as in Example 1.

Under each environment, good durability was exhibited, and light resistance and hue showed almost the same tendency as in Example 1. The results are shown in Tables 2 and 3.

Example 5 A yellow toner 12 was obtained in the same manner as in Example 1, except that a zinc compound of g-tert-butylsalicylic acid was used instead of the aluminum compound of g-tert-butylsalicylic acid. The G ′ ₁₈₀ / G ′ _{min (120-170)} of the yellow toner 12 was 2.0, and the softening point was 93 ° C.

The gloss and chromaticity of the image of the yellow toner 12 were examined in the same manner as in Example 1. The results are shown in Tables 2 and 3.

Although both lightness and chroma were slightly reduced, the yellow image was within a practical level. Yellow toner N
o. The image was extracted under low temperature and low humidity environment using
The image was good in endurance of 10,000 sheets, but after about 20,000 sheets, a decrease in density and fogging were observed, and the halftone portion was rough.

In the high-temperature, high-humidity environment, the image was slightly fogged from the beginning, but was within a practical level. The results are shown in Tables 2 and 3.

[0234]

[Table 2]

[0235]

[Table 3]

Example 6 Polyester Resin No. 70 parts by weight [Condensed polymer composed of polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane, terephthalic acid, fumaric acid, and trimellitic acid (acid value 10.
3 mg KOH / g, Tg = 56 ° C., Mn = 3900, M
w = 12700, Tm = 90 ° C.) 30 parts by weight of the yellow pigment represented by the structural formula (1) (the ratio of the major axis to the minor axis of the primary particles is 1.3, the number average particle diameter is 0.28 μm, and the specific surface area is 30% by weight. 77m ² / g) The above-mentioned materials were charged into a kneader-type mixer, the temperature was raised under non-pressure while mixing, and the mixture was sufficiently premixed. Thereafter, the mixture was kneaded twice with three rolls to obtain a first kneaded material.

16.7 parts by weight of the above kneaded material (pigment particle content: 30 parts by weight) 6 88.3 parts by weight-Aluminum compound of di-tert-butylsalicylic acid 4 parts by weight The above-mentioned materials are sufficiently premixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, cooled, and then cooled by a hammer mill. It was roughly pulverized by about 1 to 2 mm, and then finely pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized material was strictly and simultaneously removed with a multi-division classifier to obtain yellow toner particles having a weight average diameter of 6.5 μm.

On the other hand, as a fluidity improver and a charge stabilizer, hydrophilic alumina fine powder (primary average particle diameter 0.005
μm, BET specific surface area: 250 m ² / g) 100 parts by weight, and surface treatment using 30 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ to give a primary average particle diameter of 0.005
A hydrophobic alumina fine powder B having a particle size of 70 μm and a hydrophobicity of 70% was obtained.

100 parts by weight of yellow toner particles and 1.2 parts by weight of hydrophobic alumina fine powder B were mixed to obtain a yellow toner having hydrophobic alumina fine particles on the surface of yellow toner particles. 6 was prepared.

The yellow toner No. No. 6 and magnetic ferrite carrier particles (average particle size: 40 μm) surface-coated with a silicone resin were mixed so that the toner concentration became 6% by weight to obtain a two-component yellow developer.

The above two-component yellow developer was used in a commercial plain paper full-color copying machine (color laser copying machine CLC70).
0, manufactured by Canon Inc.), and a copy test was performed. The image density was as high as 1.7 to 1.8 even in a durability test of 50,000 sheets under a normal temperature and normal humidity environment (23 ° C., 60%). Shows the density and the initial fluctuation is small in the charging characteristics.
/ Kg to -26 mC / kg.

After the end of 50,000 sheets, no filming due to fusion of the toner was observed on the surface of the photosensitive drum, and no cleaning failure occurred during this time.

No offset to the fixing roller occurred at all in the 50,000-sheet durability copy. The surface of the fixing roller after the endurance was visually observed, and there was no contamination by the toner.

When the surface of the carrier in the developer after 50,000 sheets of durability was observed by an SEM, almost no toner spent was observed.

Further, in a high temperature and high humidity environment (30 ° C., 80%)
A durability test was performed on 50,000 sheets under a low-temperature and low-humidity environment (15 ° C., 10%), but no fog or scattering occurred, and the image density remained almost stable.

Next, instead of the yellow pigment, C.I. I.
Pigment Blue 15: 3 is used in an amount of 6.5 parts by weight in the same manner as above except that 4 parts by weight of Pigment Blue 15: 3 is used.
m cyan toner particles were obtained.

Further, in place of the yellow pigment, C.I.
I. Pigment Red 122 is used in the same manner except that 5 parts by weight of Pigment Red 122 is used.
m magenta toner particles were obtained.

The obtained cyan color toner particles and magenta color toner particles were each mixed with 1.2 parts by weight of hydrophobic alumina fine powder B in the same manner as the yellow toner to have hydrophobic alumina fine particles B on the particle surface. A cyan toner and a magenta toner were obtained, respectively, and thereafter, a two-component cyan developer and a two-component magenta developer were similarly prepared.

The amount of toner on the unfixed transfer material is 0.8% for yellow toner, magenta toner and cyan toner.
The contrast potential of the main body was adjusted so as to be mg / cm ² , and a green solid image was output with the yellow toner and the cyan toner, and a red solid image was output with the yellow toner and the magenta toner.

The gloss and chromaticity of each image in Example 6 are as shown in Table 4 below.

[0251]

[Table 4]

According to the yellow toner No. of the present invention, By using No. 6, images of green and red, which are secondary colors, were also high in brightness and saturation.

Further, the transparency film on which a color image was formed using the transparency film as a transfer material was transferred to an overhead projector (OH
The transparency of the OHP image projected on P) was also good.

The transparency of the OHP image in the above embodiment was evaluated based on the following evaluation criteria by projecting a color image formed by the above-mentioned yellow toner on a transparency film using a commercially available overhead projector. did. The results are shown in Tables 6 and 7.

Comparative Example 8 Instead of the yellow pigment used in Example 6, the ratio of the major axis to the minor axis of the primary particle diameter was 2.1, the specific surface area was 36 m ² / g,
Except that the pigment represented by the formula (1) having a number average particle diameter of 0.42 μm was used, the weight average diameter was 6.6 in the same manner as in Example 6.
μm of comparative yellow toner no. 8 was prepared. When the image formation was evaluated in the same manner as in Example 6, almost the same results were obtained in terms of the durability, except that the absolute value of the charge amount was higher than that in Example 6. The charge amount during durability is -27 to -3
The value fluctuated between 0 mC / kg and the image density was relatively stable.

However, the hue of the obtained yellow image was reddish as a whole, and was not suitable as a full-color yellow toner. Further, when the transparency of OHP was examined, it was inferior to that of Example 7.

Comparative Yellow Toner No. When the gloss and the chromaticity of the image No. 8 were examined in the same manner as in Example 6, the results shown in Table 5 were obtained.

[0258]

[Table 5]

Comparative Example 9 Comparative Yellow Toner No. 9 was prepared in the same manner as in Example 6, except that the aluminum compound of tert-butylsalicylic acid was not used. 9 was obtained.

When the durability was evaluated in the same manner as in Example 6, in the durability under a low-temperature and low-humidity environment, the image density was reduced from about the 3000th sheet and fogging began to occur slightly.

In a high-temperature, high-humidity environment, the comparative yellow toner no. The charge amount of No. 9 was too low, and scattering and fogging occurred from the beginning of the endurance, and the endurance was interrupted.

In the endurance performed in a normal temperature and normal humidity environment, a part of offset occurred around the 5,000th sheet. When the endurance was suspended and the fixing roller was examined, the fixing roller was contaminated with toner. I was

Comparative Yellow Toner No. Ninth image was examined for gloss and chromaticity in the same manner as in Example 1. The results are shown in Tables 6 and 7.

Comparative Yellow Toner No. 9 has a lower softening point than the toner of Example 6, so that the brightness and the chroma are lower under the same fixing conditions, despite the fact that the gloss of the image is higher. This is considered to be due to poor dispersion of the colorant.

The transparency of the actual OHP image was not very good.

Comparative Example 10 The polyester resin No. used in Example 6 In place of polyester resin No. 6 7 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid, and crosslinked polyester resin synthesized from trimellitic acid (acid value 1.9 mgKOH / g, Tg = 59 ° C,
(Mn = 4100, Mw = 12000, Tm = 93 ° C.)]
In the same manner as in Example 6, except that Comparative Yellow Toner No. 10 was obtained. When evaluated in the same manner as in Example 6, the durability in a low-temperature and low-humidity environment was 1000.
From around the 0th sheet, the image density began to decrease and the image became rough, and when the durability was further continued, fogging started. The initial OHP image was converted to yellow toner No. As compared with No. 6, the transparency was reduced.

Comparative Example 11 The polyester resin No. used in Example 6 In place of polyester resin No. 6 8 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid, crosslinked polyester resin synthesized from trimellitic acid (acid value 26.3 mgKOH / g, Tg = 55 ° C, M
n = 4800, Mw = 11000, Tm = 93 ° C.), except that Comparative Yellow Toner No. 11 (weight average diameter 6.5 μm) was obtained. Evaluation was made in the same manner as in Example 6. As a result, the amount of charge was low under a high-temperature and high-humidity environment, and toner scattering began to be noticeable as well as durability.

Comparative Example 12 The polyester resin No. used in Example 6 In place of polyester resin No. 6 9 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, non-crosslinked polyester resin synthesized from fumaric acid and alkenylsuccinic acid (acid value 9.8 mgKOH / g, Tg = 49 ° C., Mn = 3
200, Mw = 10200, Tm = 86 ° C.), except that Comparative Yellow Toner No. 12 (weight average diameter: 6.8 μm) was obtained.

In image formation under normal temperature and normal humidity environment, 10
The image wrapped around the fixing roller around the 0th sheet, and the durability was interrupted.

Comparative Example 13 Polyester resin No. 1 used in Example 1 In place of polyester resin No. 6 10 [polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, non-crosslinked polyester resin synthesized from isophthalic acid, terephthalic acid and maleic anhydride (acid value 10.7 mgKOH / g, Tg = 69
° C, Mn = 5400, Mw = 23300, Tm = 110
C.)) except that Comparative Yellow Toner No. 13 (weight average diameter 6.7
μm).

In image formation under a normal temperature and normal humidity environment, good toner chargeability was exhibited in the initial stage of durability, but all images had low gloss.
When compared with No. 6, both the chroma and the lightness were greatly reduced. Further, when images were imaged in a low-temperature and low-humidity environment, cold offset occurred on the fifteenth sheet and durability was interrupted.

Example 7 Instead of the yellow pigment used in Example 6, the ratio of the major axis to the minor axis of the primary particle diameter was 1.5, the specific surface area was 72 m ² / g,
Except that the pigment represented by the formula (1) having a number average particle diameter of 0.26 μm was used, the weight average diameter was 8.5 in the same manner as in Example 6.
μm yellow toner particles were obtained. A yellow toner 7 was prepared by mixing 100 parts by weight of the yellow toner particles and 1.0 part by weight of the hydrophobic alumina fine powder B used in Example 6. The results are shown in Tables 6 and 7.

Example 8 A hydrophilic alumina fine powder (primary average particle diameter: 0.02 μm) was used in place of the hydrophobic alumina fine powder B used in Example 6.
m, BET specific surface area: 130 m ² / g) 100 parts by weight, and 17 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ were used for surface treatment. Primary particle diameter 0.02 μm,
A yellow toner N was prepared in the same manner as in Example 6 except that hydrophobic alumina fine powder C having a hydrophobicity of 70% was used.
o. 8 was prepared and evaluated in the same manner as in Example 6.

Under each environment, good durability was exhibited, and light resistance and hue showed almost the same tendency as in Example 6.

Example 9 A hydrophilic titanium oxide fine powder (primary average particle diameter: 0.05 μm) was used in place of the hydrophobic alumina fine powder B used in Example 6.
m, BET specific surface area: 140 m ² / g) 100 parts by weight of n-C ₄ H ₉ —Si (OCH ₃ ) ₃ was used for surface treatment using 15 parts by weight. The same procedure as in Example 1 was carried out except that hydrophobic titanium oxide fine powder B having a primary particle diameter of 0.05 μm and a hydrophobicity of 70% was used.
9 was prepared and evaluated in the same manner as in Example 6.

Under each environment, good durability was exhibited, and light resistance and hue showed almost the same tendency as in Example 6.

Example 10 A hydrophilic titanium oxide fine powder (primary average particle size: 0.05 μm) was used in place of the hydrophobic alumina fine powder B used in Example 6.
m, BET specific surface area: 140 m ² / g), except that it was used as it was without surface treatment. 10 was prepared and Example 6 was prepared.
The evaluation was performed in the same manner as described above.

In a high-temperature, high-humidity environment, the initial charge amount was as low as -16 mC / kg, which was almost the level of durability evaluation. Furthermore, when the durability was advanced under the same environment, the image became rough with a halftone portion, but it was within a practical level. However, the charge amount one day after the image was left standing was reduced by about 3 mC / kg as compared to that before the image was left standing.

Example 11 Hydrophobic silica (primary average particle size: 0.007 μm, BET) was used in place of the hydrophobic alumina fine powder B used in Example 6.
(Specific surface area: 380 m ² / g) Except for using hydrophobic silica having a primary particle diameter of 0.007 μm and a hydrophobicity of 65%, which was surface-treated using 20 parts by weight of hexamethyldisilazane with respect to 100 parts by weight. In the same manner as in Example 6, the yellow toner No. 11 was obtained. Yellow toner No.
11 and evaluated in the same manner as in Example 6. In durability under a low-temperature and low-humidity environment, the charge amount of the toner began to increase and the image density began to decrease around the 2,000th sheet.

[0280]

[Table 6]

[0281]

[Table 7]

[0282]

The yellow toner for developing an electrostatic image of the present invention has excellent low-temperature fixability and anti-offset properties, high coloring power, excellent transparency and light resistance, and has the effects of being resistant to fading. Therefore, the yellow toner of the present invention can be suitably used as a yellow toner for forming a full-color image.

[Brief description of the drawings]

FIG. 1 is a graph showing a storage modulus of a yellow toner according to Example 1 of the present invention.

FIG. 2 is a diagram illustrating a graph of a conventional general yellow toner in which the storage elastic modulus of the yellow toner decreases as the temperature increases.

FIG. 3 is a schematic explanatory view showing an example of a full-color image forming apparatus to which the yellow toner of the present invention can be applied.

FIG. 4 is a schematic explanatory view of a measuring device for measuring a triboelectric charge amount of toner particles and toner.

[Explanation of symbols]

 Reference Signs List 51 suction machine 52 measuring container 53 screen 54 lid 55 vacuum gauge 56 air flow control valve 57 suction port 58 condenser 59 electrometer

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[Procedure amendment]

[Submission date] April 17, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Outside 1] Wherein the primary particles of the yellow colorant have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of yellow colorants present as independent particles in the yellow toner particles. An electrostatic image developing yellow toner having an average diameter of 0.1 to 0.7 μm.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction contents]

[0047]

[Outside 3] Wherein the primary particles of the yellow colorant have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of yellow colorants present as independent particles in the yellow toner particles. The present invention relates to a yellow toner for developing an electrostatic image, having an average diameter of 0.1 to 0.7 μm.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0170

[Correction method] Change

[Correction contents]

[0170]

[Outside 6]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 9/08 381 (72) Inventor Tetsuya Ida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (31)

[Claims] 1. A yellow toner for developing an electrostatic image having yellow toner particles containing at least a binder resin and a yellow colorant, wherein the yellow toner has a storage elastic modulus G ′ _{180 of} 180 ° C. and a temperature of 180 ° C. The minimum value G ′ of the storage elastic modulus of the yellow toner in the range of 120 ° C. to 170 ° C.
min _(120-170) [G ' ₁₈₀ / G'min
_(120-170) ] is 2.0 to 8.0, and the binder resin contains a polyester resin having a glass transition temperature of 50 to 65 ° C and an acid value of 2.0 to 25.0 mgKOH / g. The yellow colorant has the following formula (1) Wherein the primary particles of the yellow colorant have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of yellow colorants present as independent particles in the yellow toner particles. An electrostatic image developing yellow toner having an average diameter of 0.1 to 0.7 μm. 2. The yellow colorant in the yellow toner particles has a content ratio of primary particles and secondary particles present as independent particles having a particle size of 0.1 to 0.5 μm of 60% by number or more. The content ratio of independent primary particles and secondary particles having a diameter of 0.8 µm or more is 0 to 10% by number.
Yellow toner. 3. The yellow colorant in the yellow toner particles contains 65% by number or more of primary particles and secondary particles present as independent particles having a particle size of 0.1 to 0.5 μm. 1 yellow toner. 4. The yellow colorant in the yellow toner particles has a content ratio of primary particles and secondary particles present as independent particles having a particle size of 0.1 to 0.5 μm of 70% by number or more. 1 yellow toner. 5. The yellow toner according to claim 1, wherein the yellow toner particles contain a metal compound of an aromatic carboxylic acid. 6. The yellow toner according to claim 5, wherein the aromatic carboxylic acid is an aromatic hydroxycarboxylic acid selected from the group consisting of salicylic acid, monoalkyl salicylic acid and dialkyl salicylic acid. 7. The yellow toner according to claim 5, wherein the aromatic carboxylic acid is di-tert-butyl salicylic acid. 8. The metal compound of an aromatic carboxylic acid comprises a metal salt of salicylic acid, a metal complex of salicylic acid, a metal salt of alkyl salicylic acid, a metal complex of alkyl salicylic acid, a metal salt of dialkyl lithic acid, and a metal complex of dialkyl salicylic acid. The yellow toner according to claim 5, which is a metal compound selected from the group. 9. The yellow toner according to claim 5, wherein the metal compound of the aromatic carboxylic acid is an aluminum compound of an aromatic hydroxycarboxylic acid. 10. The yellow toner according to claim 5, wherein the metal compound of the aromatic carboxylic acid is an aluminum compound of di-tert-butylsalicylic acid. 11. The binder resin has a glass transition temperature of 52 to 50.
The yellow toner according to any one of claims 1 to 10, wherein the temperature is 65 ° C. 12. The binder resin has a glass transition temperature of from 53 to 53.
The yellow toner according to any one of claims 1 to 10, wherein the temperature is 64 ° C. 13. The polyester resin having an acid value of 5.0 to 2
The yellow toner according to any one of claims 1 to 12, wherein the amount is 0.0 mgKOH / g. 14. A polyester resin comprising a dihydric alcohol, a divalent dicarboxylic acid and the following formula (3): [In the formula, n is an integer of 3 or more, and R is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. The radicals R are the same or different. The yellow toner according to any one of claims 1 to 13, wherein the polyester resin is a polyester resin produced from the polyvalent carboxylic acid, an acid anhydride thereof, or an ester compound thereof. 15. The polyester resin according to claim 1, wherein the polyester resin has a number average molecular weight (Mn) of 1,500 to 50,000 and a weight average molecular weight (Mw) of 6,000 to 100,000. Yellow toner. 16. The polyester resin according to claim 1, wherein the polyester resin has a number average molecular weight (Mn) of 2,000 to 20,000 and a weight average molecular weight (Mw) of 10,000 to 90,000. Yellow toner. 17. The yellow toner according to claim 1, wherein the polyester resin has a value of Mw / Mn of 2 to 8. 18. The yellow toner according to claim 1, wherein the yellow colorant is contained in the yellow toner particles in an amount of 1 to 15 parts by weight per 100 parts by weight of the binder resin. 19. The yellow toner according to claim 1, wherein the yellow colorant is contained in 3 to 12 parts by weight of the yellow toner particles per 100 parts by weight of the binder resin. 20. The yellow toner according to claim 1, wherein the yellow colorant is contained in the yellow toner particles in an amount of 4 to 10 parts by weight per 100 parts by weight of the binder resin. 21. The yellow toner has a softening point (Tm) of 9
The yellow toner according to any one of claims 1 to 20, wherein the temperature is 0C to 115C. 22. The yellow toner according to claim 1, wherein the weight average particle diameter (D ₄ ) of the yellow toner particles is ₃ to 15 μm. 23. The yellow toner according to claim 1, wherein the weight average particle diameter (D ₄ ) of the yellow toner particles is ₄ to 12 μm. 24. The yellow toner according to claim 1, wherein the weight average particle diameter of the yellow toner particles is 4 to 8 μm. 25. The yellow toner particles have a weight average particle size of 4 to 8 μm, and the yellow colorant has a particle size of 0.1 to 8 μm.
The content ratio of 0.5 μm particles is 70% by number or more,
2. The yellow toner according to claim 1, wherein the content ratio of the particles having a particle diameter of 0.8 [mu] m or more is 0 to 5% by number. 26. The yellow toner has a softening point (T) higher than the softening point of the polyester resin before melt-kneading by 3 ° C. or more.
The yellow toner according to any one of claims 1 to 25, wherein m) is satisfied. 27. The yellow toner has a softening point (T) higher by at least 4 ° C. than the softening point of the polyester resin before melt-kneading.
The yellow toner according to any one of claims 1 to 25, wherein m) is satisfied. 28. The yellow toner particles have an average particle diameter of 0.1.
The yellow toner according to any one of claims 1 to 27, further comprising externally added titanium oxide fine powder having a hydrophobicity of 005 to 0.1 µm. 29. The yellow toner particles have an average particle size of 0.1.
The yellow toner according to any one of claims 1 to 27, further comprising externally added aluminum oxide fine powder having a hydrophobicity of 005 to 0.1 µm. 30. The yellow toner according to claim 1, wherein the yellow toner has negative chargeability. 31. The yellow toner particles are obtained by melt-kneading a mixture containing at least the polyester resin, the yellow colorant and a metal compound of an aromatic hydroxycarboxylic acid, cooling the kneaded material, and pulverizing the cooled kneaded material. 2. A yellow colored resin particle produced by the above method.
Any one of the yellow toners of (1) to (30).