JP3372859B2 - Yellow toner for developing electrostatic images - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION 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 wide color reproducibility of a full-color image, excellent offset resistance and low-temperature fixing property, and further 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 received 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.

In color image formation by full-color electrophotography, color reproduction is generally performed by using color toners of three primary colors of yellow, magenta, and cyan or four colors of black added thereto.

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

Full-color electrophotography in which several kinds of toner layers of different colors transferred onto the transfer material with or without the intermediate transfer material are developed by performing such development a plurality of times. In the method, the fixing property of each color toner is an important factor.

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

Further, it is preferable that the upper color toner layer has transparency that does not hinder the color tone of the different color toner layers of the lower layer, and it is important that the color toner has wide color reproducibility. Is.

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

The color toners described above have a considerably sharp melt property, and when combined with a silicone rubber roller capable of applying silicone oil, the toner particles are heated and pressure-fixed in a state close to complete melting at the time of fixing. Since the shape of (1) changes, favorable glossiness and color reproducibility can be obtained.

In these toners, it means that the viscous term is more important than the elastic term in the viscoelastic characteristic of the binder resin as the fixing characteristic of the toner.

The melt viscosity of these toners rapidly decreases when heated and pressed, and a fixed image having excellent glossiness 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 therefore the toner adheres to the heat roller when passing through the fixing device. The tendency is to increase. In this case, the high temperature offset phenomenon is likely to occur.

In order to solve or reduce the above problems, Japanese Patent Laid-Open Nos. 60960/55 and 20855 / 57-20855.
No. 9, JP-A-58-11953, JP-A-58.
No. 14144 and JP-A No. 60-123852 propose methods of adding a low-molecular-weight polyethylene wax, polypropylene wax, higher fatty acid, etc., which are releasable components, to toner particles. While these methods are effective in preventing offset, inclusion of a large amount of releasing component in order to sufficiently exhibit offset resistance reduces transparency of the OHP image of the color toner; charging property of the color toner Is unstable; adverse effects such as deterioration in durability of a large number of color toners are recognized.

Japanese Patent Laid-Open Nos. 47-12334 and 5
In JP-A 7-37353 and JP-A-57-208559, an etherified bisphenol monomer,
As a binder, a non-linear polyester resin obtained from a monomer component containing a dicarboxylic acid monomer and a trivalent or higher polyvalent alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer Toners containing are proposed. In these toners, a polyester composed of an etherified bisphenol monomer and a dicarboxylic acid monomer is crosslinked with a polyhydric alcohol monomer having a valence of 3 or more and / or a large amount of a polycarboxylic acid monomer having a valence of 3 or more. By including the polyester obtained by the above as a binder resin, the offset prevention performance of the toner is improved. However, these toners have a slightly higher softening point, and 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 fixability and the sharp melt property are poor. Therefore, the color toner using the polyester resin has sufficient color mixing property and color reproducibility. is not. JP-A-57-109825, JP-A-62-78568
JP-A-62-78569, JP-A-59-
In JP 7960 and JP-A 59-29256, an etherified bisphenol monomer, a dicarboxylic acid monomer into which a long-chain aliphatic hydrocarbon is introduced, and other dicarboxylic acid monomers are trivalent or more. Of a non-linear copolymer obtained from the polyhydric alcohol monomer and / or a monomer component containing a polyvalent carboxylic acid monomer having a valence of 3 or more as a main chain and having 3 to 3 carbon atoms in its side chain. A toner containing 22 polyester resins having a saturated or unsaturated aliphatic hydrocarbon group as a binder has been proposed. These polyester resins are mainly intended for use in high-speed copying black toner. As the viscoelastic properties of these polyester resins, contrary to the above-mentioned viscosity-oriented polyester,
By increasing the elastic term, the high temperature offset to the heating roller is remarkably reduced. Then, at the time of fixing, the pressure and heat of the heat and pressure roller fixing device are increased as much as possible, and the toner is pressed in a semi-molten state between the fibers of the transfer paper to perform pressure and heat fixing.

Therefore, in these toners, the toner layer is not completely melted and a continuous film is not formed, and it is almost impossible to obtain a smooth surface. The fixed toner exists in a particle state on the transfer paper, and the obtained color image is dull and has poor saturation. In the OHP image on which these toners are fixed, the light is scattered on the surface of the toner particles, and almost no light is transmitted, which is not practically preferable. In principle, if there are three primary colors, yellow, magenta, and cyan, it is possible to reproduce almost all colors by the subtractive color mixing method, and ideally, any color tone 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 of the toner when superposed and fixed, and the deterioration of the saturation.

When black is obtained by superimposing three colors, a toner layer three times as much as that of a monochromatic color is formed on the transfer paper, which further increases the difficulty of offset resistance.

There is an ever increasing demand for quality of electrophotographic full color images. For a general user who is regarded as a printing user, a full-color image obtained by an electrophotographic method is desired to have a level closer to printing and a level closer to silver halide photography.

One of the methods to meet these requirements is that the colorant present in the toner particles is uniformly dispersed.

In JP-A-61-117565 and JP-A-61-156054, a binder resin, a colorant, a charge control agent and the like are previously dissolved and / or dispersed in a solvent and the solvent is removed. A method of obtaining a toner is disclosed. These are problematic in that it is difficult to control the dispersibility of the charge control agent in the binder resin, and the solvent tends to remain in the final product toner, resulting in 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.

Japanese Unexamined Patent Publication No. 61-91666 discloses a method for producing a toner using a halogen-based solvent.
Since the halogen-based solvent has strong polarity, there is a problem that the colorant used is limited.

JP-A-4-39671 and JP-A-4-39671
Japanese Patent No. 39672 and Japanese Patent Laid-Open No. 4-242752 disclose a method of producing a toner while heating and pressurizing 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 cleaved by a strong kneading load, and the polymer component is partially reduced in molecular weight. Therefore, high temperature offset is likely to occur in the fixing process. Particularly in a full-color image, since toners of three or four colors are layered and fixed, a high-temperature offset is likely to occur due to the molecular weight reduction due to molecular scission in the polymer component.

On the other hand, in the conventional sharp-melting resin having excellent color reproducibility, when the resin and the colorant are kneaded, the shearing force at the time of kneading does not become large, so that the colorant is difficult to disperse. Especially when a pigment having high cohesiveness is used as a colorant, the tendency is remarkable.

Therefore, in order to satisfy both the offset resistance and the fixing property, and also the dispersibility of the colorant, the design of the resin and the selection of the colorant are very important.

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. It develops an electrostatic image. Therefore, in order to obtain a good toner image, it is necessary that the toner has good triboelectric chargeability.

In recent years, demands for high definition and high image quality of copying machines or printers have been increasing in the market, and in this technical field, an attempt has been made to achieve high image quality color by making the particle diameter of color toner fine. ing. When the particle diameter of the toner is small, the surface area per unit weight is increased, and the charge amount of the toner tends to be large, and the image density is low and the durability is apt to deteriorate. In addition, since the charge amount of the toner is large, the adhesion between the toner particles is strong, the fluidity is lowered, and problems such as stability of toner replenishment and imparting tribo to the replenishment toner are likely to occur.

Further, since the color toner does not contain a black conductive material such as a magnetic substance or carbon black, there is no portion for leaking charge, and the charge amount generally tends to be large. This tendency is particularly remarkable when a polyester resin having a high negative charge performance is used as the binder resin.

Polyester resin is widely used as a binder resin for color toners in this technical field, but yellow color toners having polyester resin are generally easily affected by temperature and humidity, and the amount of charge is excessive under low humidity. However, problems such as insufficient charge amount under high humidity are likely to occur, and development of a yellow color toner having a stable charge amount even in a wide range of environments is desired.

It is known that the charge of the yellow color toner changes greatly depending on the degree of dispersibility of the yellow colorant in the binder resin, and in the yellow toner color in which the yellow colorant is poorly dispersed, fog or toner scattering occurs. Such problems as described above are likely to occur, and various problems such as toner spent on the carrier, toner filming on the drum, and contamination of the fixing roller are likely to occur. Therefore, in addition to the color reproducibility, improving the dispersibility of the yellow colorant is an important technical issue.

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

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

Although the above yellow pigment is superior in light resistance to dyes, it is more light-resistant than quinacridone pigments used for magenta toner and copper phthalocyanine pigments used for cyan toner. It is inferior in properties, and there is a problem that in a long-time light exposure test, color resistance or color change is noticeable.

On the other hand, a yellow pigment excellent in light resistance and heat resistance, on the contrary, has too strong hiding power, and the transparency of the toner is extremely deteriorated, so that the yellow pigment for full color image formation is not suitable.

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

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

In order to solve the above-mentioned problems, Japanese Patent Laid-Open No. 8-209017 discloses a yellow pigment in which the specific surface area of the yellow pigment is improved to improve transparency and tinting strength. Electrophotographic toners are described. However, C.I. I. When the pigment classified into Pigment Yellow 180 is miniaturized, the negative chargeability of the pigment itself is significantly reduced, and the toner using the pigment has a shortage of charge amount, in particular, a shortage of charge amount under high temperature and high humidity. The need arises to solve the problem.

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

[0037]

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

The 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 image that has excellent light resistance and is resistant to fading.

An object of the present invention is to provide a yellow toner for developing an electrostatic image capable of forming 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.

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

An object of the present invention is to provide a yellow toner for developing an electrostatic image which is less likely to cause toner fusion to parts such as a developing sleeve, a blade and a coating roller in a developing device.

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 due to the toner on a photoreceptor for forming an electrostatic charge image.

An object of the present invention is to provide a yellow toner for developing an electrostatic image in which the heating roller and the pressure roller are less likely to be contaminated and winding of the transfer material around the heating roller is less likely to occur.

[0046]

SUMMARY OF THE INVENTION The present invention is a yellow toner for developing electrostatic images, which comprises yellow toner particles containing at least a binder resin and a yellow colorant, the yellow toner having an angular frequency of 3.17 rad / sec. Storage modulus G ′ ₁₈₀ of yellow toner at a temperature of 180 ° C. and a temperature of 120 ° C. to 170 ° C.
Ratio of the storage modulus of the yellow toner to the minimum value G'min _(120-170) [G ' ₁₈₀ /
G'min _(120-170) ] is 2.0 to 8.0, the binder resin is a polyester having a glass transition temperature of 50 to 65 ° C. and an acid value of 2.0 to 25.0 mgKOH / g. A yellow colorant containing a resin is represented by the following formula (1)

[0047]

[Outside 3] The primary particles of the yellow colorant having a compound represented by the formula (1) have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of the yellow colorant present as independent particles in the yellow toner particles. The present invention relates to a yellow toner for developing an electrostatic charge image, which has an average diameter of 0.1 to 0.7 μm.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION The yellow pigment represented by the formula (1) (CI Pigment Yellow 180) is usually a needle-shaped crystal form in which primary particles have a ratio of major axis to minor axis of more than 1.6. And has many primary particles with a large major axis. Such primary particles and secondary particles of the yellow pigment are difficult to produce a kneaded product having high transparency even when melt-kneaded with the binder resin. As described above, JP-A-8
-209017 (Corresponding Canadian Application Publication No. 21
No. 59872 or corresponding EP-A-705886) BE
An electrophotographic toner containing an azo yellow pigment represented by the formula (1) having a T specific surface area of more than 45 m ² / g and containing fine particles and having a ratio of major axis to minor axis of 1.6 or less. Is listed. Even in the case of the azo yellow pigment described in JP-A-8-209017, the yellow pigment particles composed of fine primary particles have a strong self-aggregating property when simply melt-kneaded with an ordinary binder resin, and the yellow pigment is a yellow pigment. It was difficult to uniformly disperse the above 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 to 65 ° C. and an acid value of 2.0 to 2.
By using 5.0 mgKOH / g of polyester resin and a resin composition for toner having a viscoelastic property in which the storage elastic modulus G ′ is improved by heating, a number average particle diameter (also referred to as a length average particle diameter) 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, and the azo yellow pigment represented by the formula (1) is uniformly dispersed in the binder resin as fine independent particles. Can be dispersed in.

The yellow toner of the present invention containing the compound represented by the formula (1) as a yellow colorant in a fine state shows a greenish (green) yellow color,
It has preferable spectral characteristics as a yellow toner for forming a full-color image. Further, the yellow toner containing the compound represented by the formula (1) in a fine state has high lightness and saturation. The reproducibility of human skin color in a full-color image is important, but when the yellow toner containing the compound represented by the formula (1) is used, the human skin color can be reproduced well, and the overhead projector (OHP) can be used. Excellent 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. Therefore, the number average particle diameter 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 independent particles (primary particles and secondary particles)
More preferably at least 65% by number, most preferably 7%
Dispersed particle size of the colorant such that 0 number% or more is included and independent particles (primary particles and secondary particles) having a particle size of 0.8 μm or more are included in 10 number%, more preferably 0 to 5 number%. Is preferably controlled.

The number average particle diameter of the yellow colorant is 0.7 μm.
When it is larger than m, it basically means that a large amount of yellow colorant particles which are not sufficiently dispersed are present in the toner particles, which is not good in color reproducibility and transparency of the transparency film. . Further, if the yellow colorant particles in the toner particles are present as an agglomerate in a non-uniform state, the charging variation between the toner particles becomes significant, 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 is 60% by number or more, more preferably 65% by number or more, and most preferably 7% by weight of particles having a particle size of 0.1 to 0.5 μm.
It is preferable that the content is 0% by number or more.

Until now, when discussing the dispersed particle size of the colorant, only the average particle size was inevitably emphasized.
The particle size distribution of the dispersed colorant is extremely important for improving color reproducibility.

When the dispersed particle diameter of the colorant is broad, a large difference occurs in the degree of dispersion of the colorant among the toner particles. If the colorant is not well dispersed, diffused 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 dispersed particle size distribution is as sharp as possible so that the spectral reflection characteristics of the colorant can be maximized.

Basically, it is considered that the colorant having a fine particle diameter smaller than 0.1 μm does not adversely affect the light reflection and absorption characteristics. Particles of colorant less than 0.1 μm contribute to good color reproduction and transparency of OHP sheets with fixed images. On the other hand, when many colorants having a particle size larger than 0.5 μm are present, the brightness and color of the projected image on the OHP sheet tend to be inevitably lowered.

Therefore, 0.1% of the yellow toner particles
It is preferable that the colorant having a particle diameter of 0.5 μm is contained in an amount of 60 number% or more, preferably 65 number% or more, more preferably 70 number% or more. When the yellow toner particles have a predetermined amount of the primary particles and secondary particles of the yellow colorant represented by the formula (1) having a particle diameter of 0.1 to 0.5 μm, the deterioration of the 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 full-color images.

Furthermore, 0.8 μm is contained in the yellow toner particles.
It is preferable that the yellow colorant particles having the above particle diameter are contained in an amount of 0 to 10% by number, more preferably 0 to 5% by number,
Basically, it is preferable that there are no particles of 0.8 μm or more at all or less. When the toner particles contain more than 10% by number of the yellow colorant having a large particle size of 0.8 μm or more, the yellow colorant having such a large particle size exists near the surface of the yellow toner particles. In that case, 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, it causes a problem such as carrier contamination, and it is difficult to obtain a stable image even when it is used for many sheets. Naturally, good color reproducibility cannot be expected, and uniform chargeability is difficult to obtain.

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, based on 100 parts by weight of the binder resin.
More preferably, it is contained in an amount of 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, in addition, the reproducibility of the intermediate color typified by human skin color is lowered. It will be easier. Further, the stability of the triboelectric chargeability of the yellow toner is lowered, and it becomes difficult to obtain the desired negative triboelectric charge amount.

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

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

Acid value of polyester resin is 2.0 mg KO
If it is less than H / g, it is difficult to increase the viscosity of the kneaded product with time during melt-kneading, and the yellow toner tends to have a charge-up tendency, and the image density tends to be low 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 lowered, the charge amount between the yellow toner particles is likely to be different, and fogging is likely to occur in the long-term durability.

Acid value of polyester resin is 25.0 mgK
When it is higher than OH / g, the stability of the yellow toner against charging is deteriorated, and the charge amount is likely to be decreased with the endurance. Particularly in a high temperature and high humidity environment, image defects such as toner scattering and fog 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 acid value of the polyester resin is preferably 3.0 to 22.0 mgKOH / g, more preferably 5.0 to 20.0 mgKOH / g.

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

The polyester resin has a glass transition temperature of 50.
When the temperature is lower than 0 ° C, the fixing property is excellent, but the offset resistance is lowered, 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 will be lowered, and the set fixing temperature of the copier or printer will have to be raised, and the obtained image generally has low gloss, and the color mixing property with other color toners will be lowered. To do.

The polyester resin used in the present invention is
The number average molecular weight (Mn) is preferably 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
10,000, more preferably 10,000 to 90,000
It is 0, and Mw / Mn is preferably 2-8. A polyester resin satisfying the above conditions has good heat fixing property, improves the dispersibility of the yellow colorant, reduces the fluctuation of the charge amount of the yellow toner, and improves the reliability of the image quality.

Number average molecular weight (Mn) of polyester resin
When the value is less than 1,500 or when the weight average molecular weight (Mw) is less than 6,000, the smoothness of the fixed image surface is high and the vividness is visible, but an offset occurs when many sheets are used. In addition, the storage stability is lowered, and toner fusion in the developing device and toner spent in which the toner component adheres to the carrier surface are likely to occur. Further, when melt-kneading the toner raw material at the time of manufacturing the yellow toner particles, shear is less likely to occur, the dispersibility of the yellow colorant is likely to decrease, and the generated triboelectric property of the yellow toner tends to vary.

Number average molecular weight (Mn) of polyester resin
Of more than 50,000 or weight average molecular weight (M
When w) exceeds 100,000, although the offset resistance is excellent, the fixing set temperature is unavoidably increased, and even if the degree of dispersion of the colorant can be controlled, the image area of The surface smoothness deteriorates, and the color reproducibility easily deteriorates.

When the Mw / Mn of the polyester resin is less than 2, the molecular weight of the polyester resin generally obtained becomes small. Therefore, as in the case where the molecular weight is small, an offset phenomenon due to durability and storage stability are obtained. Of the toner, toner fusion in the developing device and toner spent of the carrier easily occur, and blocking of the yellow toner easily occurs.

If the Mw / Mn of the polyester resin exceeds 8, the offset resistance is excellent, but the fixing set temperature must be raised, and even if the degree of dispersion of the colorant can be controlled. As a result, the surface smoothness in the image area is reduced, and the color reproducibility is likely to be reduced.

[0074] In the toner of the present invention, storage at 180 ° C. modulus G _'180 (frequency 3.14rad / se
The ratio of c) to the minimum storage modulus _{G'min (120-170)} in the temperature range of 120 ° C to 170 ° C is _2.0≤G ' ₁₈₀ / G' _{min (120-170)} ≤ One of the features is that it is 8.0. _G'180 / G '
_When the value of _{min (120-170)} is less than 2.0, it means that the increase rate of the viscosity of the resin composition forming the toner with heating is small. Therefore, shearing force is less likely to be applied to the yellow colorant during melt-kneading, and it is difficult to reduce the size of the agglomerated coarse secondary particles of the yellow colorant. On the other hand, G _'180 / G' if the value of _{min (120-170)} is more than 8.0, since the elastic properties of the yellow toner is too increased at a high temperature side, the low-temperature fixability and other during heating pressure fixing The color mixing property with the color toner tends to decrease.

[0075] yellow toner G _'180 / G'
_As one of the preferable means for adjusting the value of _{min (120-170)} to 2.0 to 8.0, melt kneading with a polyester resin having an acid value of 2 to 25 mgKOH / g crosslinked with a polycarboxylic acid. At times, it is possible to use a metal compound of an aromatic carboxylic acid 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 a flow tester curve of 85 ° C. ≦ T.
It is preferable that m ≦ 120 ° C.

The softening point temperature Tm of the yellow toner is 120.
When the temperature is higher than ℃, the anti-offset property is excellent, but the fixing set temperature must be raised, and even if the degree of pigment dispersion 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 the vividness is visible, but the offset tends to occur in the durability of many sheets. Further, the storage stability is poor, and the problem of fusion of the yellow toner in the developing device is likely to occur. The softening point temperature Tm of the yellow color toner is more preferably 90 ° C to 115 ° C.

In the present invention, terephthalic acid, isophthalic acid, phthalic acid, diphenyl-, etc. are used as the divalent acid component or ester component for constituting the polyester resin.
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 and 1,2-diphenoxyethane-P, P'-dicarboxylic acid and ester compounds thereof can be mentioned. Other acid components or ester components include maleic acid, fumaric acid, glital acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid, itaconic acid,
Citraconic acid, sebacic acid, anhydrides of these acids, and lower alkyl esters can be used.

The dihydric alcohol component is represented by the following formula (2)

[0081]

[Outside 4] (In the formula, R ₁ is an alkylene group having 2 to 5 carbon atoms,
X and Y are positive numbers, and examples thereof include diol compounds represented by 2 ≦ X + Y ≦ 6). G'of yellow toner
_In order to adjust the value of ₁₈₀ / _{G'min (120-170)} to 2.0 to 8.0, R ₁ is preferably 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,
Examples include neopentyl glycol, diols such as 1,4-butene diol; 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) is used.

[0084]

[Outside 5] [In the Formula, n is an integer greater than or equal to 3, R is a hydrogen atom, a C1-C18 alkyl group, a C2-C18 alkenyl group, or a C6-C18 aryl group, and each substitution The R's in the groups are the same or different. ] It is preferable to use the polyvalent carboxylic acid or its acid anhydride or ester compound shown by these as a structural component of polyester resin.

Examples of the above-mentioned polyvalent carboxylic acid or ester compound include trimellitic acid, tri-n-ethyl 1,2,4-benzenetricarboxylate, tri-n-butyl 1,2,4-benzenetricarboxylic acid, and 1,2. , 4-benzenetricarboxylic acid tri-n-hexyl, 1,2,4-benzenetricarboxylic acid triisobutyl, 1,2,4-benzenetricarboxylic acid tri-n-octyl, 1,2,4-benzenetricarboxylic acid tri-2-ethylhexyl , Pyromellitic acid, 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. An acid having an alkyl or alkenyl substituent such as and / or an ethylene glycol having an n-dodecenyl group, an isododecenyl group, an n-dodecyl group, an isododecyl group or an isooctyl group, 1,3-propylene diol, tetramethylene glycol, 1 , 4-
It is also preferable to use an alcohol having an alkyl substituent or an alkenyl substituent such as butylene diol and 1,5-pentyl diol as a component for constituting the polyester resin.

Examples of the production method for obtaining the polyester resin include the following methods.

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 becomes more uniform than before. Allow the condensation reaction to proceed slowly and gradually. For example, (i) the reaction is performed at a lower temperature and for a longer time than in the conventional case. (Ii) using a monomer having low reactivity, or
(Iii) The esterification reaction is controlled by using these methods in combination. After that, 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 increase the temperature and slowly to ensure a uniform molecular weight distribution.
Allow the reaction to proceed for a long time, proceed with the crosslinking reaction, and terminate the reaction when the hydroxyl value, acid value or MI value reaches the target value,
A polyester resin suitable for the purpose is obtained.

[0089] The value of _{G '180 / G' min (} 120-170) 2.0
In order to adjust the particle size to 8.0, it is preferable that the toner particles contain a metal compound of an aromatic carboxylic acid. Glass transition temperature is 50 to 65 ° C. and acid value is 2
To 25 mgKOH / g of polyester resin, the average value of the ratio of the major axis to the minor axis of the primary particles is 1.5 or less, and the number average particle diameter of the primary particles is 0.1 to 0.7 μm ( When the yellow colorant represented by 1) and the metal compound of aromatic carboxylic acid are melt-kneaded, a metal cross-linking structure is partially formed in the polyester resin during melt-kneading, and the viscosity of the kneaded product gradually increases during kneading. . Therefore, the melt viscosity of the kneaded product is significantly higher than the melt viscosity of the binder resin alone. Therefore, the self-aggregation force is strong because the primary particles of the yellow colorant are fine, and even if there are coarse secondary particles of the yellow colorant, the coarse secondary particles will not be generated due to sufficient shearing force generated during melt kneading. Primary particles and /
Alternatively, it is crushed into fine secondary particles. As a result, a melt-kneaded product in which the primary particles and the fine secondary particles of the yellow colorant are uniformly dispersed can be efficiently produced.

Although details are not clear, a portion of the imino group in the yellow colorant represented by the formula (1) and a portion of the carbonyl group of the carboxylic acid group in the polyester resin are partially hydrogen-bonded or static. Bonding by electric interaction further enhances the dispersibility of the yellow colorant in the polyester resin, and also suppresses the adsorption of water to the ester bond part in the molecular chain of the polyester resin. It is presumed that it is possible to suppress the decrease in the charge amount in a humid environment. The metal compound of aromatic carboxylic acid also functions as a negative charge control agent that improves and stabilizes the negative triboelectric chargeability of the yellow toner.

Preferred aromatic carboxylic acids for forming the metal compound include salicylic acid, monoalkyl salicylic acid or dialkyl salicylic acid. In particular,
Dialkyl salicylic acid is preferred, especially di-tert.
-Butylsalicylic acid is especially preferred.

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

In the present invention, aluminum is preferable as the metal element of the metal compound of aromatic carboxylic acid. An aluminum compound is preferable to a metal compound such as zinc because the crosslinking reaction with the polyester resin during kneading easily proceeds.

When the metal compound of aromatic carboxylic acid is contained in the yellow toner particles, its content is
The amount is 2 to 10 parts by weight, more preferably 3 to 8 parts by weight, based on 100 parts by weight of the binder resin. When the amount of the metal compound of the aromatic carboxylic acid added is 2 to 10 parts by weight, the crosslinking reaction with the polyester resin proceeds favorably during melt kneading, and the yellow colorant is finely and uniformly dispersed in the polyester resin. It is preferable because the negative triboelectric chargeability 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 polyester resin has few metal cross-linking portions and the melt viscosity does not increase, or even if the melt viscosity increases, the increase rate is small and the negative charge controlling effect of the yellow toner is small. If the amount of the metal compound of aromatic carboxylic acid is more than 10 parts by weight, the amount of the metal cross-linking portion of the polyester resin becomes too large and the low temperature fixing property of the yellow toner and the color mixing property with other color toners are deteriorated. 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 due to the interaction between a specific polyester resin and a metal compound of an aromatic carboxylic acid to increase the share of secondary particles of the yellow colorant during kneading. Due to this, the yellow colorant is finely and uniformly dispersed, and at the time of heat and pressure fixing, it excels in rapid melting property even at low temperature side, strongly exerts elastic properties at high temperature side, and offset occurs. It is a yellow toner designed to be difficult to do. In the yellow toner of the present invention, a fatty acid metal salt (eg, zinc stearate, aluminum stearate) as a lubricant, a fluorine-containing polymer fine powder (eg, polytetrafluoroethylene, polyvinylidene fluoride and tetrafluoro) may be added, if necessary. A fine powder of ethylene-vinylidene fluoride copolymer) or a conductivity-imparting agent such as tin oxide and zinc oxide may be added.

Further, in the present invention, the yellow toner particles may contain a releasing agent. For example, an aliphatic hydrocarbon wax, an oxide of an aliphatic hydrocarbon wax, an ester wax, a wax composition containing a fatty acid ester as a main component, which is solid at room temperature, a saturated linear fatty acid, an unsaturated fatty acid, a saturated alcohol, and a polyhydric alcohol. Alcohol, fatty acid amide,
Examples thereof include saturated fatty acid bisamide, unsaturated fatty acid amide, and aromatic bisamide.

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.

When the content of the release agent exceeds 20 parts by weight, the blocking resistance and the high temperature offset resistance tend to be lowered, and when it is less than 0.1 part by weight, the release effect is small. .

These mold releasing agents are usually prepared by dissolving a resin in a solvent, raising the temperature of the resin solution, adding the mold releasing agent to the binder resin in advance with stirring and mixing, or a toner constituent material at the time of kneading. And a release agent are mixed and contained in the toner particles.

As a method for producing yellow toner particles according to the present invention, a binder resin, a yellow colorant, a metal compound of an aromatic carboxylic acid, and other additives are added and uniformly mixed with a mixer such as a Henschel mixer. After that, the mixture is melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder, mutually compatible and dispersed, cooled and solidified, and then pulverized and strictly classified to produce yellow toner particles having a desired viscosity. There is a method. The melt-kneading temperature is preferably 120 to 170 ° C.

In the present invention, the yellow colorant is added to a part of the binder resin in advance and dispersed, and then the above dispersion is used for the rest of the binder resin, the metal compound of the aromatic carboxylic acid, and further, if necessary. Other additives may be added accordingly, and thereafter melt-kneading, cooling, pulverization, and classification may be performed. Examples of the step of previously dispersing the yellow colorant in the binder resin include a conventionally known masterbatch method and a flushing method.

In the present invention, the weight average particle diameter 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 diameter of the yellow toner particles is 3 μm.
If it is less than m, it becomes difficult to stabilize the charging,
Fogging and toner scattering in the image forming apparatus are likely to occur in the endurance of a large number of sheets.

The weight average particle diameter of the yellow toner particles is 15
When it exceeds μm, the reproducibility of the halftone portion is deteriorated, and the obtained image tends to be a rough image.

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

In the fluidity improver as an external additive, it is an important factor to enhance the fluidity of the yellow toner and not hinder the charging property of the yellow toner.

Therefore, the surface of the titanium oxide fine powder or the aluminum oxide fine powder is preferably hydrophobized, whereby it becomes possible to satisfy both the impartation of fluidity and the stabilization of charging.

Since the titanium oxide fine powder or the aluminum oxide fine powder is subjected to the hydrophobic treatment, the influence of water, which is a factor affecting the charge amount, is excluded, and the difference in the charge amount under high humidity and low humidity is eliminated. It is possible to improve the environmental characteristics of the yellow toner by reducing the amount. Furthermore, it becomes possible to disintegrate the aggregation of primary particles during the hydrophobic treatment step, and it becomes possible for the external additive with less secondary aggregation to give more uniform charge to the yellow toner.

In the present invention, particularly titanium oxide fine powder or alumina fine powder having an average primary particle diameter of 0.005 to 0.1 μm has good fluidity and the negatively chargeable yellow toner is uniformly charged, resulting in toner. It is preferable because scattering and fog are less likely to occur. Furthermore, it is difficult for the toner particles to be embedded on the surface of the yellow toner particles, and toner deterioration is less likely to occur,
The durability of many sheets is improved. This tendency is more remarkable in the yellow toner having a sharp melt property.

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 likely to be embedded on the surface of the yellow color toner particles, and the toner deterioration is likely to occur quickly. Durability easily decreases. This tendency is more remarkable than when it is applied to a yellow toner having a sharp melt property.

When it exceeds 0.1 μm, the fluidity of the yellow toner is low and the yellow toner is liable to be unevenly charged, resulting in a decrease in resolution, toner scattering and fog. It becomes difficult to generate a high-quality toner image.

In the yellow toner of the present invention, the addition amount of titanium oxide fine powder or aluminum oxide fine powder is
It is preferably 0. 0 with respect to 100 parts by weight of yellow toner particles.
5 to 5.0 parts by weight, more preferably 0.7 to 3.0 parts by weight, still more preferably 1.0 to 2.5 parts by weight. The yellow toner satisfying the above range has good fluidity, can maintain a stable charge amount, and is unlikely to cause toner scattering.

When the yellow toner of the present invention is used in a two-component developer, the carrier used is, for example, a surface-oxidized or non-oxidized metal such as iron, nickel, copper, zinc, cobalt, manganese, chromium, or a rare earth metal. Particles and their magnetic alloy particles or magnetic oxide particles and magnetic ferrite particles are mentioned.

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

As the coating material for the carrier core, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, amino acrylate resin is used. Can be mentioned. These are used alone or in plural.

The treatment amount of the above materials may be appropriately determined, but generally, the total amount is 0.01 to 5% by weight, preferably 0.05 to 3% by weight, based on the carrier, based on the carrier.
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, 0.01 to 5% by weight of a resin such as a silicone resin, a fluorine resin, a styrene resin, an acrylic resin and a methacrylate resin is used on the surface of a magnetic core particle such as a magnetic ferrite core particle. A resin-coated magnetic carrier having an average particle diameter of 0.05 to 3% by weight and preferably 70% by weight or more of carrier particles of 250 mesh pass and 400 mesh on is included.

When the resin-coated magnetic carrier has a sharp particle size distribution, it preferably has a triboelectric charging property with respect to the yellow toner of the present invention, and has an effect of improving electrophotographic characteristics.

When a two-component developer is prepared by mixing a yellow toner and a carrier, the mixing ratio is 2% by weight to 15% by weight, preferably 3% by weight to 13% by weight, as a toner concentration in the developer. %, More preferably 4% by weight to 1
At 0% by weight, good results are usually obtained. If the toner density is less than 2% by weight, the image density tends to be low.
If it exceeds 5% by weight, fog or scattering in the machine tends 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 of forming a full-color image by electrophotography.
Will be described with reference to.

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 section and the digital color image printer section are provided below.

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

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 supported 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 and 4K having different colors, and an on-drum light amount detecting means 13 are provided. A transfer device 5 and a cleaning device 6 are arranged.

In the laser exposure optical system, the 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. It is projected onto the surface of the photosensitive drum 1 via the lens 3b and the mirror 3c.

The printer section uses the photosensitive drum 1 during image formation.
Is rotated in the direction of the arrow, and the photosensitive drum 1 is uniformly negatively charged by the charger 2 after the charge is removed by the pre-exposure lamp 11, and the optical image E is irradiated for each separated color, and the electrostatic charge is applied to the photosensitive drum 1. Form an image.

Next, by operating a predetermined developing device, the electrostatic charge image on the photosensitive drum 1 is developed by, for example, a reversal developing method, and a toner image is formed on the photosensitive drum 1 by toner. The developing devices 4Y, 4C, 4M, and 4K have eccentric cams 2 respectively.
By the operations of 4Y, 24C, 24M, and 24K, the photosensitive drum 1 is selectively approached in accordance with each separated color, and development is performed.

The transfer device includes a transfer drum 5a, a transfer charger 5b, an attraction charger 5c for electrostatically attracting a transfer paper or an OHP sheet as a transfer material, an attraction roller 5g facing the attraction roller 5g, and an inner charger 5d. , Outer charger 5e,
It has a separation charger 5h. The transfer drum 5a is rotatably rotatably supported, and a transfer sheet 5f, which is a transfer material carrier that carries a transfer material, is integrally adjusted on a cylinder in an opening area of its peripheral surface. A resin film such as a polycarbonate film is used for the transfer sheet 5f.

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

The toner image may be directly transferred from the photosensitive member to the transfer material as shown in FIG. 3, or the toner image on the photosensitive member 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.

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

The transfer material on which the four color toner images have been transferred in this way is separated from the transfer drum 5a by the action of the separating claw 8a, the separating push-up roller 8b and the separating charger 5h, and is heated and pressed. 9, the toner is mixed under heat and fixed there by fixing the toner on the transfer material by color mixing and color development, and after a full-color fixed image is formed, it is ejected to the tray 10 and the formation of the full-color image is completed. To 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, a fur brush or a non-woven fabric, or a combination thereof may be used instead of the blade.

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

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

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

Next, methods for measuring each physical property will be described below.

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

The number average particle diameter and major axis of the yellow colorant and
Measurement of 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 0.1 μm or more,
The ratio of the average values is taken as the ratio of the major axis and the minor axis.

The number average particle diameter of the yellow colorant is an average value of major axes of the primary particles of the yellow pigment particles.

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

Of the yellow colorant in the yellow toner particles
Measurement of particle size Yellow toner or yellow toner particles are added to a 2.3 M sucrose solution, stirred well, put a small amount on a sample holder pin, then put into liquid N ₂ to solidify, and immediately set on the sample arm head. To do.

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

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

The image information is introduced into the image analysis device (Luzex3) manufactured by Nikole Co. through the interface, and 2
Convert to value image data. Among them, only the pigment particles having a primary particle size of 0.1 μm or more and secondary particles are randomly analyzed, and the sampling number is 30
The measurement is repeated until it exceeds 0 times, and the number average particle size 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 particles and secondary particles of the yellow colorant having a size larger than 0.1 μm are measured.
The particle size referred to in the present invention is to measure the area of each pigment particle image,
The diameter of a circle having the same area as the area is defined as the particle size of each pigment particle.

Measurement of Toner Particles and Particle Size Distribution of Toner As a measuring device, Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter) is used. The electrolyte is approximately 1% using first-grade sodium chloride.
An aqueous NaCl solution is prepared. For example, ISTON R-
II (Made by Coulter Scientific Japan)
Can be used. As a measuring method, the electrolytic aqueous solution 10
To 0 to 150 ml, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and 100 μm as an aperture is measured by the measuring device.
Particle size 2.00 to 40.30 using m aperture
The volume and number of toner particles of μm are measured for each channel to calculate the toner volume distribution and number distribution. Then, the weight-based weight average particle diameter (D4) of the toner particles obtained from the volume distribution of the toner particles (the median value of each channel is set as a representative value for each channel) is calculated.

Particles externally added to the toner particles as external additives have a particle size of 2.00 μm or more, and therefore the weight average particle size (D4 ) Has been confirmed to have a value substantially the same as the weight average particle diameter (D ₄ ) of the toner particles.

The channels are 2.00 to 2.52.
μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm
m; 4.00 to 5.04 μm; 5.04 to 6.35 μ
m; 6.35 to 8.00 μm; 8.00 to 10.08 μm
m; 10.08-12.70 μm; 12.70-16.
00 μm; 16.0-20.20 μm; 20.20
25.40 μm; 25.40-32.00 μm; 32.
13 channels of 00-40.30 μm are used.

Method of measuring acid value 2 to 10 g of a 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 seems to be poor, a small amount of acetone may be added. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titrate with a standardized alcohol solution of 0.1N potassium hydroxide in advance, and calculate the acid value from the consumption of the alcohol potash by the following calculation. .

[0150] Acid value = [KOH (ml number) × N × 56.1] / sample weight (In the formula, N is a factor of 0.1 N KOH solution)

Method for Measuring Triboelectric Charge Amount FIG. 4 is an explanatory diagram of an apparatus for measuring triboelectric charge amount. About 0.5 to 1.5 g of the developer collected from the developing sleeve of the copying machine or the printer is put in a metallic measuring container 52 having a 500 mesh screen 53 at the bottom, and a metallic lid 54 is placed. At this time, weigh the entire measuring container 52 and W
₁ (g). Next, in the suction device 51 (at least the portion in contact with the measurement container 52 is an insulator), suction is performed from the suction port 57 to adjust the air volume control valve 56, and the pressure of the vacuum gauge 55 is adjusted to 2
It is set to 50 mmAq. In this state, the toner is suctioned sufficiently, preferably for 2 minutes to remove the toner by suction. Electrometer 5 at this time
The potential is 9 V (volt). Here, 58 is a condenser, and the capacitance is C (mF). The weight of the entire measuring container after suction is weighed and is W ₂ (g). The triboelectric charge amount (mC / kg) of this sample is calculated by the following formula.

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

Planarization of titanium oxide fine particles and alumina fine particles
Measuring method of uniform particle diameter The primary particle diameter is 300 pieces of 0.005 μm or more of 300 pieces which are magnified 30,000 to 50,000 times in the visual field by observing titanium oxide fine particles and alumina fine particles with a transmission electron microscope. The average particle size is calculated by observing the dispersed particle size on the toner particles with a scanning electron microscope, and 300 titanium and alumina fine particles in the field of view magnified 30,000 to 50,000 times are qualitatively determined by XMA. To determine the average particle size.

Measurement of glass transition temperature Tg: Differential thermal analysis measuring device (DSC measuring device), for example DSC
It measures using -7 (made by Perkin-Elmer company).

The measurement sample is 5 to 20 mg, preferably 10
Precisely weigh mg.

This was placed in an aluminum pan, and an empty aluminum pan was used as a reference, and the measurement temperature range was 30 ° C to 2 ° C.
The measurement is performed at a temperature rising rate of 10 ° C./min between 00 ° C. and normal temperature and normal humidity.

During this temperature rising process, the endothermic peak of the main peak in the temperature range of 40 to 100 ° C. is obtained.

At this time, the intersection between the line at the midpoint of the baseline and the differential heat curve before and after the endothermic peak appears
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. A sample weighs about 1.0 g of a 60 mesh pass product. Using a molding machine, this is pressed for 1 minute with a load of 100 kg / cm ² .

This pressurized sample is subjected to flow tester measurement under the following conditions at room temperature and normal humidity (temperature of about 20 to 30 ° C., humidity of 30 to 70% RH) to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the temperature (= T _1/2 ) 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 (seconds) 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) as a solvent was flowed through the column at this temperature at a flow rate of 1 ml / min to obtain T
Inject 100 μl of HF sample solvent for measurement. When measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, a molecular weight of 10 ² to 10 manufactured by Tosoh or Showa Denko KK
^It is appropriate to use about ⁷ standard polystyrene samples and at least about 10 standard polystyrene samples. R1 for the detector
A (refractive index) detector is used. As the column, it is preferable to use a plurality of commercially available polystyrene gel columns in combination.

For example, Shodex G manufactured by Showa Denko KK
PC KF-801, 802, 803, 804, 80
5,806,807,800P combination, Tosoh 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 mentioned.

The sample is manufactured as follows.

The sample is placed in THF, left for several hours, shaken well and mixed well with THF (until the coalescence of the sample disappears), and left still for 12 hours or more. At this time T
The time of leaving in HF should be 24 hours or more.
Then sample processing filter (pore size 0.45
~ 0.5 μm, for example, Mysholydisk H-25-
5 Tosoh's Excicro disk 25CR, German,
The material that has passed through (for example, Science Japan Co., Ltd. can be used) is used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

Method for Measuring BET Specific Surface Area The BET specific surface area of the pigment is 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. As a pretreatment of the sample, degassing is performed at a temperature of 50 ° C. for 10 hours.

Method for Measuring Average Particle Diameter of Carrier 0.70 to 700 μm was used as a carrier by using Microtrac particle size analyzer SRA type (manufactured by Nikkiso Co., Ltd.).
Measurement is performed with the range setting of 50
In the present invention, the% particle size is the average particle size of the carrier.

[0168]

The present invention will be described in more detail based on examples.

Example 1 Polyester Resin No. 170 parts by weight [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.)] A yellow pigment represented by the following structural formula (number average diameter of 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]

Charge the above materials in a kneader type mixer,
While mixing, the temperature was raised under non-pressurization to thoroughly premix.
Then, the mixture was kneaded twice with a three-roll to obtain a first kneaded product.

The first kneaded material (content of pigment particles: 3
0% by weight) 16.7 parts by weight of polyester resin No. 1 88.3 parts by weight Aluminum compound of di-tertiary-butyl-salicylic acid 4 parts by weight The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded at a temperature of 125 to 130 ° C. with a twin-screw extruder, and after cooling. Coarse pulverization was carried out for about 1 to 2 mm using a hammer mill, and then fine pulverization was carried out by a fine pulverizer using an air jet system. Further, the finely pulverized product thus obtained was subjected to strict removal of fine powder and coarse powder at the same time with a multi-division classifier to obtain a weight average diameter of 6.5 μm
m yellow toner particles are obtained.

On the other hand, hydrophilic titanium oxide fine powder (average primary particle size 0.02) was used as a fluidity improver and a charge stabilizer.
μm, BET specific surface area 140 m ² / g) 100 parts by weight, and surface-treated with 20 parts by weight of n-C ₄ H ₉ —Si (OCH ₃ ) ₃ to obtain a primary average particle diameter of 0.02 μm.
A hydrophobic titanium oxide fine powder A having a hydrophobicity of 70% was obtained.

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

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

The yellow toner No. 1 and magnetic ferrite carrier particles surface-coated with a silicone resin (average particle diameter 40 μm) were mixed so as to have a toner concentration of 6% by weight to obtain a two-component yellow developer.

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

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

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

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

Furthermore, high temperature and high humidity environment (30 ° C., 80%)
Under a low temperature and low humidity environment (15 ° C., 10%), a durability test of 50,000 sheets was carried out, but no fog or scattering occurred, and the image density remained almost stable.

Cyan toner particles having a weight average diameter of 6.5 μm were obtained in substantially the same manner except that 4 parts by weight of a cyan pigment (CI Pigment Blue 15: 3) was used instead of the yellow pigment. Got

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

With respect to 100 parts by weight of the obtained cyan toner particles and 100 parts by weight of magenta toner particles, yellow toner No. Hydrophobic titanium oxide fine powder A in the same manner as in 1.
Cyan toners and magenta toners having hydrophobic titanium oxide fine particles A on the particle surfaces were respectively obtained by mixing 1.5 parts by weight, and the two-component cyan developer and the two-component magenta developer were obtained in the same manner thereafter. Was 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 obtain mg / cm ² , and a solid green image was output using the yellow toner and the cyan toner, and a red solid image was output using 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 (glossiness) of the image surface and the chromaticity of the image. The higher the gloss value, the smoother the image surface is and the more saturated the color (C ^* )
When the gloss value is low and the gloss value is low,
It is judged that the image surface with dull saturation (C ^* ) is rough. Note that "C ^* " means the following formula from the values of a ^* and b ^* measured by the following method.

[0187]

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

A VG-10 type gloss meter manufactured by Nippon Denshoku Co., Ltd. was used for the measurement of gloss (glossiness). In the measurement,
First, set the voltage to 6V by a constant voltage device, then adjust the light projecting angle and the light receiving angle to 60 ° respectively, and use the zero point adjustment and standard plate.
The sample images were placed on top of each other, and the numerical value shown in the marking part was read in%.

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 ^* , b ^* (a ^* , b ^* are chromaticities indicating hue and saturation) and L ^* (lightness) were measured. An X-Rite spectrophotometer type 938 was used as a measuring instrument, a light source for observation was a C light source, and a viewing angle was 2 °.

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

[0191]

[Table 1]

Yellow toner No. 1 of the present invention. When 1 was used, images of secondary colors green and red also had high lightness and saturation.

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

Regarding the transparency of the OHP image in the above examples, a commercially available overhead projector was used to project a color image formed by the above yellow toner on a transparency film, and the transparency was evaluated based on the following evaluation criteria. did.

Evaluation Criteria A: Excellent transparency, no uneven brightness and excellent color reproducibility. (Good) B: Although there is slight unevenness in brightness and darkness, there is no problem in practical use.
(Fair) C: There is uneven brightness, and color reproducibility is poor. (bad)

The light fastness of the obtained yellow solid image (image density 1.70) was confirmed according to JIS K7102, and the image density (1. 63) and ΔE is 3.
6 and the change in hue was only slight. A carbon arc lamp was used as the light source.

The hue change was quantitatively evaluated based on the following light resistance evaluation criteria by obtaining the ΔE value of the following formula.

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

Evaluation criteria for light resistance A: Does not fade even after irradiation for 400 hours. B: Does not fade even after irradiation for 200 hours. C: Fading after irradiation for 100 hours.

Comparative Example 1 Comparative Yellow Toner No. 1 was prepared in the same manner as in Example 1 except that the aluminum compound of ditertiary butylsalicylic acid was not used. Got 1. 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. The graph of G'of No. 1 is shown in FIG.

When the durability was evaluated in the same manner as in Example 1, the image density was reduced from around the 3,000th sheet and some fog started to occur in the durability under the low temperature and low humidity environment.

Under the high temperature and high humidity environment, the comparative yellow toner No. The charge amount of No. 1 decreased, and the image density increased accordingly, and scattering and fogging started to occur.

Further, in the durability test carried out under the normal temperature and normal humidity environment, some offset occurred around the 5,000th sheet, and when the durability roller was discontinued and the fixing roller was examined, the fixing roller was contaminated with the toner. Was there.

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 is lower in lightness and chroma than the toner of Example 1 because the softening point of the toner is low and therefore the gloss of the image is high under the same fixing conditions, but this is because the dispersion of the colorant is low. It is thought that it is due to the badness of.

The transparency of the actual OHP image was never good.

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

No serious problems occurred in the durability under the normal temperature and normal humidity environment, but the charge amount of the toner decreased and the fog occurred during the durability under the high temperature and high humidity environment. In addition, when the fixing roller after running 20,000 sheets was examined, it was found to be contaminated with yellow toner. The results are shown in Tables 2 and 3.

Comparative Example 3 Polyester resin No. 1 used in Example 1 In place of 1, polyester resin No. 3 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid and trimellitic acid crosslinked polyester resin (acid value 15 mg KOH / g, Tg = 59 ° C., Mn = 5
600, Mw = 22000, Tm = 98 ° C.)] and the use of 8 parts by weight of an aluminum compound of diethyl butylsalicylic acid was carried out in the same manner as in Example 1, except that Comparative Yellow Toner No. Got 3. Comparative yellow toner No. _3'G ' ₁₈₀ / G' _{min (120-170)}
Was 8.8 and the softening point was 116 ° C.

Although the initial image had a low gloss as a whole, no fog was observed and the highlight reproducibility was good.
However, when images were printed in a low temperature and low humidity environment, cold offset occurred on the 30th sheet and the durability was interrupted. Further OHP
The transparency of the image was never good either.

Comparative Yellow Toner No. The gloss and chromaticity of the image of No. 3 were examined 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. 3 of Example 1. Compared with No. 1, the toner had a high softening point, so the gloss of the image was low under the same fixing conditions, and the brightness and saturation 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 In place of 1, styrene / acrylic resin [copolymer of styrene and n-butyl acrylate (acid value substantially zero, Tg = 60 ° C., Mn = 4800, Mw =
15000, Tm = 96 ° C.)],
In the same manner as in Example 1, the comparative yellow toner No. Got 4. Comparative yellow toner No. The image of No. 4 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. In No. 4, both lightness and saturation were lower than those in Example 1.

Also, comparative yellow toner No. When No. 4 was used for durability in a low-temperature and low-humidity environment, the amount of charge increased and a low image density occurred, and the durability was interrupted midway.

Comparative Example 5 The number average particle diameter of primary particles was 0.38 μm, the ratio of major axis to minor axis was 1.8, and the specific surface area was 39 m ² / g. I. Comparative Yellow Toner N as in Example 1 except that Pigment 180 is used.
o. 5 was prepared. Comparative yellow toner No. 5'G
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 the primary particles and the secondary particles as independent particles of the yellow pigment in the yellow toner particles is 0.58 μm, and the particle diameter of 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 diameter 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. The results are shown in Table 2.
And shown in Table 3.

Comparative Yellow Toner No. In No. 5, both lightness and saturation were lower than those in Example 1. Comparative yellow toner No. 5 and the cyan toner produced in Example 1 were used to form a green solid image in the same manner as in Example 1. The gloss was 27%, L ^* was 44, and a ^* was -52. And b ^* was 17, and the saturation of the green solid image was low.

Further, the comparative yellow toner No. When No. 5 was used for durability in a low-temperature and low-humidity environment, the amount of charge increased and a low image density occurred.

Comparative Example 6 Instead of the colorant used in Example 1, the following formula (4)

[0220]

[Outside 8] A yellow colorant (C.I.P.) of the compound (4)
IGMENT Yellow 74) was used in the same manner as in Example 1 except that 7 parts by weight of 100 parts by weight of the polyester resin was used. 6
Was obtained and evaluated in the same manner as in Example 1. From the time of about 5,000 sheets in durability of many sheets under high temperature and high humidity environment, the comparative yellow toner No. The charge amount of No. 6 began to decrease, and the fog began to stand out, so the durability was interrupted.

Further, the compound (4) had a lower coloring power than the compound (1) used in Example 1, and the contrast potential of a full-color copying machine was used to obtain an image with high image density. I had to raise it more than in Example 1. The results are shown in Tables 2 and 3.

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

[0223]

[Outside 9] A yellow colorant (C.I.P.) of the compound (5) represented by
IGMENT Yellow 12) is used in the same manner as in Example 1 except that 5 parts by weight of 100 parts by weight of the polyester resin is used. 7
Was prepared and evaluated in the same manner as in Example 1. Although the durability was relatively stable 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,
Obvious fading occurred.

Example 2 Polyester resin No. 1 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 2.4 mg
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. Got 2. When evaluated in the same manner as in Example 1, the image density began to drop from around the 20,000th sheet due to durability in a low temperature and low humidity environment, but was within a practical level.

[0225] 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 Polyester resin No. 1 used in Example 1 Instead of 1.
Polyester resin No. 5 [polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl)
Cross-linked polyester resin synthesized from propane, terephthalic acid, fumaric acid and trimellitic acid (acid value 24.2 m
gKOH / g, Tg = 54 ° C., Mn = 4800, Mw =
11000, Tm = 92 ° C.)], and in the same manner as in Example 1, except for using Yellow Toner No. Got 3. When evaluated in the same manner as in Example 1, there was no problem on the image although the amount of charge was slightly reduced in a high temperature and high humidity environment.

Yellow toner No. 3'G ' ₁₈₀ / G'
_{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) 17 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ was used for 100 parts by weight of the surface treatment. Primary average particle diameter 0.02μ
m, and yellow toner No. 1 was used in the same manner as in Example 1 except that the 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 were almost the same as those of Example 1. The results are shown in Tables 2 and 3.

Example 5 Yellow toner 12 was obtained in the same manner as in Example 1 except that a zinc compound of diethyl butyl salicylate was used instead of the aluminum compound of diethyl butyl salicylate. The yellow toner 12 had a G ′ ₁₈₀ / G ′ _{min (120-170)} of 2.0 and a softening point of 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.

Both the lightness and the saturation were slightly lowered, but it was a yellow image within a practical level. Yellow toner N
o. Image was produced in a low temperature and low humidity environment using
The image was good at the endurance of 10,000 sheets, but after about 20,000 sheets, the density was reduced and fog was observed, and the halftone portion was also rough.

In the high temperature and high humidity environment, the image had some fog from the beginning, but it was within the practical level. The results are shown in Tables 2 and 3.

[0234]

[Table 2]

[0235]

[Table 3]

Example 6 Polyester Resin No. 6 70 parts by weight [condensation polymer composed of polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane, terephthalic acid, fumaric acid, 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) (ratio of major axis to minor axis of primary particles is 1.3, number average particle diameter is 0.28 μm, specific surface area is 77 m ² / g) The above materials were placed in a kneader-type mixer, and the temperature was raised under non-pressurization while mixing, and sufficiently premixed. Then, the mixture was kneaded twice with a three-roll to obtain a first kneaded product.

-Kneaded product (content of pigment particles: 30 parts by weight) 16.7 parts by weight-Polyester resin No. 6 88.3 parts by weight Aluminum compound of di-tertiary-butyl-salicylic acid 4 parts by weight The above materials are sufficiently premixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, and after cooling, about 10% by using a hammer mill. It was roughly pulverized to about 1 to 2 mm, and then finely pulverized by an air jet type fine pulverizer. Further, the finely pulverized product thus obtained was subjected to strict removal of fine powder and coarse powder simultaneously by 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 (average primary particle size 0.005) was used.
μm, BET specific surface area of 250 m ² / g) 100 parts by weight and surface-treated with 30 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ to obtain a primary average particle diameter of 0.005.
A hydrophobic alumina fine powder B having a thickness of 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 yellow toner No. 4 having hydrophobic alumina fine particles on the surface of the yellow toner particles. 6 was prepared.

[0240] The yellow toner No. 6 and magnetic ferrite carrier particles surface-coated with a silicone resin (average particle diameter 40 μm) were mixed so as to have a toner concentration of 6% by weight to obtain a two-component yellow developer.

A commercially available plain paper full color copying machine (color laser copying machine CLC70
No. 0, manufactured by Canon Inc.) and a copy test was conducted, but the image density was as high as 1.7 to 1.8 even in the durability test of 50,000 sheets under the normal temperature and normal humidity environment (23 ° C., 60%). Concentration is shown and there is little initial fluctuation in charging characteristics, about -23 mC
/ Kg to -26 mC / kg remained stable.

Filming due to toner fusion was not observed on the surface of the photosensitive drum after the endurance of 50,000 sheets, and during this period, cleaning failure did not occur at all.

[0243] No offset to the fixing roller occurred at all even after copying 50,000 sheets. The surface of the fixing roller after the durability test was visually observed, but there was no toner contamination.

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

Furthermore, a high temperature and high humidity environment (30 ° C., 80%)
Under a low temperature and low humidity environment (15 ° C., 10%), a durability test of 50,000 sheets was carried out, 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 was used in the same manner except that 4 parts by weight of Pigment Blue 15: 3 was used.
m cyan toner particles were obtained.

Further, instead 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.

To the obtained cyan color toner particles and magenta color toner particles are mixed 1.2 parts by weight of hydrophobic alumina fine powder B in the same manner as for the yellow toner, and the hydrophobic alumina fine particles B are provided on the surface of the particles. Cyan toner and magenta toner were obtained, and thereafter, a two-component cyan developer and a two-component magenta developer were prepared in the same manner.

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 obtain mg / cm ² , and a solid green image was output using the yellow toner and the cyan toner, and a red solid image was output using the yellow toner and the magenta toner.

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

[0251]

[Table 4]

Yellow toner No. 1 of the present invention. When 6 was used, the images of secondary colors green and red also had high lightness and saturation.

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

Regarding the transparency of the OHP image in the above examples, a commercially available overhead projector was used to project the color image formed by the above yellow toner on the transparency film, and the transparency was evaluated based on the following evaluation criteria. 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 major axis to minor axis of primary particle diameter was 2.1, specific surface area was 36 m ² / g,
The weight average particle diameter was 6.6 in the same manner as in Example 6 except that the pigment represented by the formula (1) having a number average particle diameter of 0.42 μm was used.
Comparative yellow toner No. 8 was prepared. When an image was formed and evaluated in the same manner as in Example 6, almost the same result was obtained in terms of durability as compared with Example 6 except that the absolute value of the charge amount was high. The charge amount during durability is -27 to -3
It remained 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 it was not suitable as a full-color yellow toner. Furthermore, when the transparency of OHP was examined, it was inferior to that of Example 7.

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

[0258]

[Table 5]

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

When the durability was evaluated in the same manner as in Example 6, the image density was reduced from around the 3,000th sheet and some fog started to occur in the durability under the low temperature and low humidity environment.

In the high temperature and high humidity environment, the comparative yellow toner No. Since the charge amount of 9 was too low, scattering and fog occurred from the beginning of the durability, and the durability was interrupted.

Further, in the durability test carried out under the normal temperature and normal humidity environment, some offset occurred around the 5000th sheet, and the durability roller was discontinued and the fixing roller was examined. As a result, the fixing roller was contaminated with the toner. Was there.

Comparative Yellow Toner No. The gloss and chromaticity of the image of No. 9 were examined in the same manner as in Example 1. The results are shown in Tables 6 and 7.

Comparative Yellow Toner No. The toner No. 9 has a lower softening point than that of the toner of Example 6, and therefore the gloss and the saturation of the image are low under the same fixing condition, but the lightness and the saturation are low. It is considered that this is due to poor dispersion of the colorant.

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

Comparative Example 10 Polyester resin No. 1 used in Example 6 In place of 6, polyester resin No. 7 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid and trimellitic acid crosslinked polyester resin (acid value 1.9 mg KOH / g, Tg = 59 ° C,
Mn = 4100, Mw = 12000, Tm = 93 ° C.)]
Comparative Yellow Toner No. Got 10. When evaluated in the same manner as in Example 6, the durability was 1000 in a low temperature and low humidity environment.
The image density began to drop from around the 0th sheet, and the image became dull, and fog began to occur as the durability continued. The initial OHP image is a yellow toner No. When compared with 6, the transparency was lowered.

Comparative Example 11 Polyester resin No. 1 used in Example 6 In place of 6, polyester resin No. 8 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, terephthalic acid, fumaric acid, trimellitic acid crosslinked polyester resin (acid value 26.3 mg KOH / g, Tg = 55 ° C, M
n = 4800, Mw = 11000, Tm = 93 ° C.)], and the comparative yellow toner No. 11 (weight average diameter 6.5 μm) was obtained. When evaluated in the same manner as in Example 6, the charge amount was low in a high temperature and high humidity environment, and toner scattering began to stand out as the durability increased.

Comparative Example 12 Polyester resin No. 1 used in Example 6 In place of 6, polyester resin No. 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 mg KOH / g, Tg = 49 ° C., Mn = 3
200, Mw = 10200, Tm = 86 ° C.)], and in the same manner as in Example 6, Comparative Yellow Toner No. 12 (weight average diameter 6.8 μm) was obtained.

[0269] In image formation under normal temperature and normal humidity, 10
After the 0th sheet, the image was wrapped around the fixing roller and the durability was interrupted.

Comparative Example 13 Polyester resin No. 1 used in Example 1 In place of 6, polyester resin No. 10 [Polyoxypropylene (2.2) -2,2-bis (4
-Hydroxyphenyl) propane, isophthalic acid, terephthalic acid and maleic anhydride non-crosslinked polyester resin (acid value 10.7 mg KOH / g, Tg = 69
C, Mn = 5400, Mw = 23300, Tm = 110
C.)] was used in the same manner as in Example 6 except that Comparative Yellow Toner No. 13 (weight average diameter 6.7
μm) was obtained.

In image formation under a normal temperature and normal humidity environment, although good toner chargeability was exhibited at the initial stage of durability, all images had low gloss, and yellow toner No. 6 of Example 6 was used.
Comparing with No. 6, both the saturation and the brightness were greatly reduced. Further, when images were printed in a low temperature and low humidity environment, cold offset occurred on the 15th sheet and the 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 is 1.5, the specific surface area is 72 m ² / g,
A weight average particle diameter of 8.5 was obtained in the same manner as in Example 6 except that the pigment represented by the formula (1) having a number average particle diameter of 0.26 μm was used.
μm yellow toner particles were obtained. Yellow toner 7 was prepared by mixing 100 parts by weight of the yellow toner particles with 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 In place of the hydrophobic alumina fine powder B used in Example 6, hydrophilic alumina fine powder (primary average particle diameter: 0.02 μm)
m, BET specific surface area: 130 m ² / g) 17 parts by weight of iso-C ₄ H ₉ —Si (OCH ₃ ) ₃ was used for 100 parts by weight of the surface treatment. Primary particle size 0.02 μm,
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 were almost the same as those in Example 6.

Example 9 Instead of the hydrophobic alumina fine powder B used in Example 6, hydrophilic titanium oxide fine powder (primary average particle diameter: 0.05 μm) was used.
m, BET specific surface area: 140 m ² / g) 15 parts by weight of n-C ₄ H ₉ -Si (OCH ₃ ) ₃ was used for 100 parts by weight of the surface treatment. Yellow toner No. 1 was prepared in the same manner as in Example 1 except that the 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 were almost the same as those of Example 6.

Example 10 Instead of the hydrophobic alumina fine powder B used in Example 6, hydrophilic titanium oxide fine powder (primary average particle diameter: 0.05 μm) was used.
m, BET specific surface area: 140 m ² / g) was used as it was without surface treatment, and the same procedure as in Example 1 was followed. 10 was prepared and Example 6
It evaluated similarly to.

In a high temperature and high humidity environment, the initial charge amount was as low as −16 mC / kg, which was at the level of the endurance evaluation. When the durability was further advanced under the same environment, the halftone image became dull, but it was within the practical level. However, the charge amount one day after the image was left was reduced by about 3 mC / kg as compared with that before the image was left.

Example 11 In place of the hydrophobic alumina fine powder B used in Example 6, hydrophilic silica (average primary particle size: 0.007 μm, BET
Specific surface area: 380 m ² / g) Except for using hydrophobic silica having a primary particle size of 0.007 μm and a hydrophobicity of 65%, which was surface-treated with 20 parts by weight of hexamethyldisilazane per 100 parts by weight. For yellow toner No. I got 11. Yellow toner No.
11 was used and evaluated in the same manner as in Example 6. In the durability under a low temperature and low humidity environment, the charge amount of the toner started to increase and the image density started to decrease from around 2000th sheet.

[0280]

[Table 6]

[0281]

[Table 7]

[0282]

The yellow toner for developing an electrostatic image of the present invention has the effects of being excellent in low-temperature fixability and anti-offset property, having high coloring power, excellent transparency and light resistance, and 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 drawings]

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

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

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 diagram of a measuring device for measuring the triboelectric charge amount of toner particles and toner.

[Explanation of symbols]

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

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03G 9/08 381 (72) Inventor Tetsuya Ida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference References JP-A-59-214860 (JP, A) JP-A-9-34163 (JP, A) JP-A-8-262799 (JP, A) JP-A-8-209017 (JP, A) JP-A-7- 295290 (JP, A) JP-A-6-266163 (JP, A) JP-A-6-230607 (JP, A) JP-A-6-59504 (JP, A) JP-A-4-353866 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (31)

(57) [Claims] 1. A yellow toner for developing an electrostatic image, comprising yellow toner particles containing at least a binder resin and a yellow colorant, wherein the yellow toner has an angular frequency of 3.17 rad / sec.
In the measurement of the elastic modulus, the storage modulus _{G '180} of the yellow toner at a temperature 180 ° C. and the temperature 120 ° C. to 17
Ratio of the storage modulus of the yellow toner to the minimum value G'min _(120-170) in the range of 0 ° C. [G ′ ₁₈₀ /
G'min _(120-170) ] is 2.0 to 8.0, and the binder resin is a polyester having a glass transition temperature of 50 to 65 ° C. and an acid value of 2.0 to 25.0 mgKOH / g. A yellow colorant containing a resin is represented by the following formula (1) The primary particles of the yellow colorant having a compound represented by the formula (1) have an average value of the ratio of the major axis to the minor axis of 1.5 or less, and the number of the yellow colorant present as independent particles in the yellow toner particles. An electrostatic charge image developing yellow toner having an average diameter of 0.1 to 0.7 μm. 2. The yellow colorant in the yellow toner particles, wherein the content ratio of primary particles and secondary particles existing as independent particles having a particle size of 0.1 to 0.5 μm is 60 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, wherein the content ratio of primary particles and secondary particles existing as independent particles having a particle diameter of 0.1 to 0.5 μm is 65% by number or more. 1 yellow toner. 4. The yellow colorant in the yellow toner particles, wherein the content ratio of primary particles and secondary particles existing as independent particles having a particle diameter of 0.1 to 0.5 μm is 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, monoalkylsalicylic acid and dialkylsalicylic acid. 7. The yellow toner according to claim 5, wherein the aromatic carboxylic acid is ditert-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 alkylsalicylic acid, a metal complex of alkylsalicylic acid, a metal salt of dialkyllithylic acid and a metal complex of dialkylsalicylic 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 aromatic carboxylic acid is an aluminum compound of aromatic hydroxycarboxylic acid. 10. The yellow toner according to claim 5, wherein the metal compound of aromatic carboxylic acid is an aluminum compound of ditertiary butyl salicylic acid. 11. The binder resin has a glass transition temperature of 52 to 52.
The yellow toner according to claim 1, which has a temperature of 65 ° C. 12. The binder resin has a glass transition temperature of 53 to 53.
The yellow toner according to claim 1, which has a temperature of 64 ° C. 13. A polyester resin having an acid value of 5.0 to 2
The yellow toner according to claim 1, which has an amount of 0.0 mgKOH / g. 14. The polyester resin comprises a divalent alcohol, a divalent dicarboxylic acid and a compound represented by the following formula (3): [In the Formula, n is an integer greater than or equal to 3, R is a hydrogen atom, a C1-C18 alkyl group, a C2-C18 alkenyl group, or a C6-C18 aryl group, and each substitution The R's in the groups are the same or different. ] The yellow toner according to any one of claims 1 to 13, which is a polyester resin produced from a polyvalent carboxylic acid represented by the following formula or an acid anhydride thereof or an ester compound thereof. 15. 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 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 an Mw / Mn value of 2 to 8. 18. The yellow toner according to claim 1, wherein the yellow colorant is contained in 1 to 15 parts by weight of yellow toner particles per 100 parts by weight of a binder resin. 19. The yellow toner according to claim 1, wherein the yellow colorant is contained in 3 to 12 parts by weight of 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 4 to 10 parts by weight of the yellow toner particles per 100 parts by weight of the binder resin. 21. The softening point (Tm) of yellow toner is 9
21. The yellow toner according to claim 1, which has a temperature of 0 ° C. to 115 ° C. 22. The yellow toner according to claim 1, wherein the yellow toner particles have a weight average particle diameter (D ₄ ) of 3 to 15 μm. 23. The yellow toner according to claim 1, wherein the yellow toner particles have a weight average particle diameter (D ₄ ) of ₄ to 12 μm. 24. The yellow toner according to claim 1, wherein the yellow toner particles have a weight average particle diameter of 4 to 8 μm. 25. The yellow toner particles have a weight average particle diameter of 4 to 8 μm, and the yellow colorant has a particle diameter of 0.1 to 8 μm.
The content ratio of the particles of 0.5 μm is 70% by number or more,
The yellow toner according to claim 1, wherein the content of particles having a particle diameter of 0.8 μm or more is 0 to 5% by number. 26. The yellow toner has a softening point (T) higher by 3 ° C. or more than the softening point of the polyester resin before melt kneading.
The yellow toner according to any one of claims 1 to 25, having m). 27. The yellow toner has a softening point (T) higher by 4 ° C. or more than the softening point of the polyester resin before melt kneading.
The yellow toner according to any one of claims 1 to 25, having m). 28. The yellow toner particles have an average particle size of 0.
The yellow toner according to any one of claims 1 to 27, to which a titanium oxide fine powder having a hydrophobicity of 005 to 0.1 µm is externally added. 29. The yellow toner particles have an average particle size of 0.
The yellow toner according to any one of claims 1 to 27, to which a hydrophobized aluminum oxide fine powder of 005 to 0.1 µm is externally added. 30. The yellow toner according to claim 1, which has a negative charging property. 31. For yellow toner particles, a mixture containing at least the polyester resin, the yellow colorant and a metal compound of an aromatic hydroxycarboxylic acid is melt-kneaded, the kneaded product is cooled, and the cooled kneaded product is ground. The yellow colored resin particles produced by the above process.
30 to 30.