JP2001175033A - Yellow toner and method for producing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yellow toner excellent in triboelectric chargeability, transparency, transmittance, etc., and having good reproducibility with respect to particle size distribution and physical properties. SOLUTION: The yellow toner contains at least a pigment classified as C.I. Pigment Yellow 93 and a dye classified as C.I. Solvent Yellow 162 as colorants in a toner bonding resin based on a styrene-acrylic resin or a styrene-methacrylic resin and the circularity of the toner measured with a flow system particle image analyzer(FPIA) is 0.970 to <1.000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yellow toner and a method for producing the yellow toner in electrophotography, electrostatic recording, electrostatic printing, toner jet recording, and the like.

[0002]

2. Description of the Related Art Electrophotography is described in U.S. Pat. No. 2,297,
As described in, for example, US Pat. No. 691 and the like, a number of methods are known. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and the latent image is formed. Is developed using a toner, a toner image is transferred to a recording material such as paper as needed, and then fixed by heating, pressure, solvent vapor, or the like to obtain a copy. Conventionally, various methods have been proposed as a method of developing using toner or a method of fixing a toner image, and a method suitable for each image forming process is adopted.

In recent years, there has been a demand for high-speed copying, high image quality, and colorization of electrophotography.

In general, as a method for producing a toner, a colorant such as a dye or a pigment and an additive such as a charge control agent are melt-mixed in a thermoplastic resin, and the mixture is uniformly dispersed. There is known a method of producing a toner having a desired particle size by performing pulverization and classification by the method, that is, a pulverization method.

According to this production method (pulverization method), a considerably excellent toner can be produced, but there is a certain limitation, that is, the selection range of the toner material is limited. For example, the resin colorant dispersion must be sufficiently brittle and capable of being pulverized with economically available manufacturing equipment. Because of this requirement, the resin colorant dispersion must be made sufficiently brittle, so that when this dispersion is actually finely pulverized at a high speed, particles having a wide particle size range are easily formed, A problem arises in that a large proportion of excessively finely divided particles are included in this group of particles. Further, such a highly brittle material is more susceptible to pulverization or pulverization when actually used for development in a copying machine or the like.

[0006] Further, in the toner obtained by these pulverization methods, there is a restriction when a release agent such as wax is added. That is, in order to obtain a sufficient level of dispersibility of the release agent, it is necessary to maintain a certain degree of viscosity at the kneading temperature with the resin, and the content of the release agent should be about 5 parts by mass or less. And so on. Due to such restrictions, there is a limit to the fixability of the toner by the pulverization method.

Further, in this kneading-pulverization method, it is not easy to completely and uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of dispersion, a distribution of a toner composition occurs, and toner development characteristics In some cases. Further, generally, the resolution, solid portion uniformity, gradation reproducibility, etc. of an image formed by a toner largely depend on the characteristics of the toner, particularly the particle size thereof, and the smaller the particle size, the higher the quality of the image. Recently, printers and high-quality copiers often use a small particle size toner. However, in order to reduce the toner particle size by the pulverization method, the volume average particle size is about 5.0 μm, depending on the capacity of the pulverizer.

On the other hand, there has been proposed a method for producing a toner in which a polymerizable monomer component having at least a polymerizable monomer is subjected to suspension polymerization to obtain toner particles at the same time (hereinafter referred to as “polymerized toner”). JP-B-36-10231). In this suspension polymerization method, a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, and other additives) are uniformly dissolved or dispersed to form a monomer composition.
The monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer using a suitable stirrer, and simultaneously undergoes a polymerization reaction to obtain toner particles having a desired particle size. There are no restrictions on the items described for the pulverized toner, and there are various advantages.

That is, since the toner production method does not include a pulverizing step at all, the toner material does not need to be particularly brittle, and the toner is not exposed to the broken surface of the colorant or the like. Further, regarding the content and dispersibility of the release agent, in the polymerized toner, since the release agent component can be included in the toner particles, the content can be increased as compared with the pulverized toner, and the dispersibility is also satisfied. Can be done.
In addition, the dispersibility of the colorant does not cause any particular problem because it can be uniformly dissolved or dispersed together with other additives in the polymerizable monomer. Furthermore, since the desired particle size and particle size distribution can be controlled by the dispersion / granulation conditions, there is an advantage that it is possible to cope with a reduction in toner size.

However, such a polymerized toner also has problems to be solved as described below.

That is, in a polymerized toner, various materials are dissolved or dispersed in a polymerizable monomer system and suspended and dispersed in an aqueous medium as a polymerizable monomer composition. It is not always technically easy to stably suspend and granulate the polymerizable monomer composition particles by, for example, and complete the polymerization reaction under stable conditions in which particle coalescence does not occur.

In particular, in recent years, systems utilizing electrophotographic technology have been rapidly developed not only in conventional copiers for business processing but also in the field of printers for colorization and computer output. The process configuration has been diversified, and the physical properties of the toner required along with the control have been finely controlled not only from the conventional points of particle size distribution, fluidity and triboelectricity, but also to the control of toner shape, toner surface properties, etc. It is becoming required.

For this reason, the suspension granulation / polymerization stability of the polymerized toner is an important factor that greatly affects not only the productivity but also the physical properties of the toner. The conditions are as follows: particle coalescence / aggregation, particle size distribution,
The triboelectrification is significantly impaired, and as a result
Control of the surface state becomes impossible.

Conventionally, many proposals have been made for the purpose of stability of suspension granulation, prevention of coalescence of particles during polymerization, sharpening of particle size distribution of produced particles, and the like. For example, JP-A-57-
No. 42052, a method for controlling the particle size distribution by using a dispersant and an anionic surfactant in combination, JP-A-57-4164
9, JP-B-1-55643, JP-A-6-73101
And a number of methods for adjusting the particle size by adding an aqueous phase polymerization inhibitor in JP-A-7-165847 and the like.
However, the former has drawbacks such as residual surfactant,
As a result, the triboelectricity of the toner particles becomes unstable,
The development characteristics of the toner particles are significantly reduced. The latter has the advantage of being able to remove by-produced emulsion polymerization fine particles, but has the problem that it is not effective in reducing microsuspension particles which are more problematic as fine particles. In this case, the toner tends to cause clogging of the toner and unevenness of triboelectric charging.

On the other hand, there have been many proposals to improve the dispersion stabilizer to solve the problems of the polymerized toner. For example, as typified by JP-A-9-54457 and JP-A-7-49586, the dispersion stabilizer once produced is solubilized with an acid and then reprecipitated with an alkali to obtain a desired dispersion under an alkali. There is a proposal for a method of obtaining a stabilizer and obtaining polymerized toner particles having a sharp particle size distribution by using the stabilizer. However, at present, control including the toner particle morphology and surface properties is required, but this proposal is not suitable. No proposal has been found that is sufficient and satisfies all required physical properties.

Japanese Patent Application Laid-Open No. 7-301949 and the like disclose a method of directly producing calcium phosphate in a dispersion medium by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride. Although this method is an excellent method, for example, when sodium phosphate used industrially is used, a small amount of sodium hydroxide which is a by-product of manufacturing sodium phosphate is mixed in calcium phosphate, When an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride are mixed to form calcium phosphate salts in a dispersion medium, the pH of the aqueous medium is reduced due to the effect of sodium hydroxide present in the sodium phosphate.
When the dispersion granulation of the polymerizable monomer composition containing the polymerizable monomer, the colorant, the charge control agent, etc. is performed at such a pH, the colorant, the charge control Agents, etc. are easily decomposed, dissolved and denatured into strong alkalis, so depending on the time and temperature required for the production of toner particles, coloring agents,
An additive such as a charge control agent is decomposed, dissolved or denatured, making it difficult to produce toner particles having desired charge controllability and coloring power. Further, when additives such as a coloring agent and a charge control agent are partially dissolved, uniform dispersion of the polymerizable monomer composition particles is inhibited, and the number of fine particles increases, or agglomeration of particles occurs, The particle size distribution of the obtained toner particles tends to be non-uniform. In particular, some additives, such as colorants and charge control agents, which are weak to alkalis, cannot be used because they are severely decomposed, dissolved or denatured. Therefore, if the pH is 1
In order to produce toner particles stable in physical properties and particle size distribution in an aqueous medium near 0, it is necessary to strictly control production conditions, and furthermore, additives such as a coloring agent and a charge control agent to be used are limited. I was

As described above, in the method for producing a polymerized toner, there is no coalescence of particles during suspension granulation and polymerization, the particles are present in a stable state through the reaction, and the generated toner particles are always stable and reproducible. It has good sharp particle size distribution and uniform triboelectric charging ability, and furthermore, it is effective in satisfying all the conditions that the form or surface condition of the toner is controlled and raw materials usable as toner raw materials in this method are not limited. No means have yet been found.

On the other hand, conventional color pigments for yellow toner include C.I. I. Pigment Yellow 12 /
Azo pigments such as 13/17, C.I. I.
Pigment Yellow 74/97/98 and the like are generally used as monoazo pigments and the like. Pigments having excellent light resistance include C.I. I. Pigmen
Pigments typified by t Yellow 93/94/95/180 and the like, and benzimidazole azo pigments described in JP-A-8-262799 have been disclosed.

However, a satisfactory colorant that satisfies the above-mentioned needs and can further improve the image characteristics and the charging characteristics has not yet been obtained.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to provide a yellow toner and a method for producing the yellow toner which have solved the above-mentioned problems.

That is, an object of the present invention is to provide a yellow toner capable of obtaining a clear color even on an image having a low glossiness.

An object of the present invention is to provide a yellow toner having excellent transparency.

An object of the present invention is to provide a yellow toner having excellent light fastness.

An object of the present invention is to provide a polymerizable monomer composition suspended and granulated in an aqueous medium, which is always dispersed stably as particles, and which has good reproducibility without causing coalescence of particles during the polymerization reaction. An object of the present invention is to provide a method for producing a toner.

An object of the present invention is to provide a method for producing a yellow toner in which toner particles are always stable, have a sharp particle size distribution with good reproducibility and uniform triboelectric charging ability.

It is a further object of the present invention to provide a method for producing a yellow toner capable of always controlling the form or surface state of the generated toner particles with good reproducibility.

[0027]

SUMMARY OF THE INVENTION The present invention provides a toner binder resin mainly composed of styrene-acrylic resin or styrene-methacrylic resin, which contains C.I. I. Pigme
Pigment classified as Yellow 93 and C.nt Yellow 93. I. S
a yellow toner containing at least a dye classified as solvent Yellow 162, and having a circularity of 0.970 or more and less than 1.000 as measured by a flow type particle image analyzer (FPIA). And a yellow toner.

In the present invention, the pH of an aqueous medium containing calcium phosphate obtained by mixing an aqueous solution of a phosphate and an aqueous solution of calcium salt is adjusted to 4.0 to 6.0. A polymerizable monomer composition having at least a polymerizable monomer, a colorant, a polar polymer or a polar copolymer having a carboxyl group and a polymerization initiator is dispersed, and particles of the polymerizable monomer composition are dispersed. In the aqueous medium, the polymerizable monomer contained in the particles is polymerized to generate toner particles, and the pH of the aqueous medium is adjusted to 1.0 to 3.
0, wherein the polymerizable monomer has a styrene monomer and an acryl or methacryl monomer, and the colorant is C. I. Pigment Yellow 93 and C.I. I. Solvent Yellow
162, wherein the circularity of the obtained yellow toner measured by a flow-type particle image analyzer (FPIA) is 0.970 or more and less than 1.000. And a method for producing the same.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies on a yellow polymerization toner, the present inventors have found that a styrene-acrylic resin is used as a resin having a small amount of moisture absorption and easy charge control, and a specific yellow pigment is used for this resin. It has been found that by using a dye and a dye together, it is possible to achieve both weather resistance and colorant dispersibility.

First, the coloring agent of the present invention will be described.

One of the features of the colorant of the present invention is C.I. I. P
pigment (Structural Formula (1)) classified into C.I. Yellow 93 and C.I. I. Solvent Yellow
ow 162 and both dyes (structural formulas (2) and (3)).

[0032]

Embedded image

As already disclosed in JP-A-2-210360 and Japanese Patent Publication No. 2632423,
C. I. Pigment Yellow 93 is excellent in weather resistance and heat resistance, and is particularly suitably used for resins such as polyester and epoxy.

However, in the case of a substantially charge-neutral resin such as styrene-acryl, the effect of the chargeability of the colorant itself appears, and C.I. I. Pigment Yellow
In the case of ow93, particularly in a low humidity environment, a phenomenon occurs in which the charge amount gradually rises with the endurance.

Further, from the viewpoint of the coloring power, when the amount of the added coloring agent is increased, electrostatic agglomeration of the coloring agents occurs, and when a transmission image such as transparency is obtained, the yellow tint on the paper is reduced. It has been found that a transmission image of yellow with a strong red tint can be obtained.

For this reason, the present inventors have intensively studied additives having an effect as a charge / dispersion aid, and found that C.I. I. Solvent Ye
It has been found that a desired effect can be obtained by combining dyes classified as low 162, and the present invention has been achieved.

In order to obtain the effects of the present invention, it is preferable to specify the ratio of the colorant to be added. That is, it is preferable that each content of the pigment and the dye satisfies the following formula with respect to 100 parts by mass of the toner binder resin.

Assuming that the content of the pigment is A (parts by mass) and the content of the dye is B (parts by mass), A = 0.5 to 7.5 (more preferably 2 to 5) B = 5 to 1. 5 (more preferably 4 to 2) A / B = 0.5 to 3 When the content of the pigment is less than 0.5 part by mass, the durability of the toner decreases. On the other hand, if the content of the pigment exceeds 7.5 parts by mass, the effect of the present invention is not sufficient, and the phenomenon that the charge amount gradually rises with the endurance occurs.
In addition, when the colorants are electrostatically aggregated with each other and a transmission image such as transparency is obtained, a red transmission image different from the color on paper is obtained.

When the content of the dye exceeds 5 parts by mass, the durability is insufficient, and when it is less than 1.5 parts by mass, the effect of the present invention cannot be obtained.

When the pigment / dye content ratio exceeds 3, reddishness of a transmitted image such as transparency is generated, and 0.5
If it is less than this, the weather resistance and the rise of charging deteriorate.

Further, the total amount of the coloring agent may be selected from the viewpoints of obtaining an appropriate image density and dispersibility and economical efficiency.
The amount is preferably 2 to 7 parts by mass, more preferably 3 to 6 parts by mass with respect to 00 parts by mass.

The calcium phosphates used in the present invention include:
It has a role as a dispersant for a polymerizable monomer composition in an aqueous medium in a polymerization toner.

As substances generally considered as dispersants, for example, calcium phosphate,
Hydroxyapatite, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, etc. No. Examples of the organic compound include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and salts thereof, and starch. These are used by dispersing them in an aqueous phase.

These dispersion stabilizers prevent the aggregation of the polymerizable monomer composition particles which are uniformly dispersed in the aqueous medium and exist as droplets, and are uniformly adsorbed on the surface of the droplets. By doing so, it is considered that the droplet is stabilized. These dispersion stabilizers are solubilized after completion of the polymerization reaction of the polymerizable monomer in the droplets by an acid or alkali treatment, hot water washing, or the like, and separated from the toner particles. However, among the above substances that can be used as a dispersant, it is often difficult to completely remove the substance from the toner particle surface because of the solubility, molecular weight, viscosity, etc. of the substance, and furthermore, strong alkali treatment, hot water washing, and the like. In the steps such as, in particular, the charge / dispersion aid of the yellow pigment of the present invention and a part of the charge control agent are modified,
Since the toner particles are decomposed, eluted, or thermally deformed, the surface properties, triboelectric chargeability, color reproducibility, and the like of the toner particles may be impaired, and the developing characteristics of the toner may be significantly reduced.

Further, since the inorganic dispersant has a strong aggregating action, when the stability of the droplet is reduced due to a change in viscosity during the polymerization reaction of the droplet, the aggregation of the droplet is reversed. -Some may promote unstable development such as coalescence, and it is not easy to select the type of dispersant.

The calcium phosphates used in the present invention include:
The toner particles can be easily removed from the surface of the toner particles only by acid treatment and washing with water without causing the above-mentioned problems, and under these conditions, decomposition and decomposition of the colorant, the pigment dispersing aid, the charge control agent, etc.
Since dissolution does not occur and thermal deformation does not need to be considered, it is particularly effective as a dispersant.

The calcium phosphates described herein are:
Calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, hydroxyapatite, etc., and mixtures thereof. Considering the effects of the crystal size of these salts, the particle size of crystal aggregates, and the solubility to acids, etc. , Hydroxyapatite and calcium phosphate are preferred, and among them, hydroxyapatite is most preferred.

This calcium phosphate salt, when mixed, usually contains a calcium phosphate salt at a pH of 9.0 to 1
The method of generating and using calcium phosphate salts in an aqueous medium from an aqueous phosphate solution and an aqueous calcium salt solution, which is an aqueous medium having a pH of 4.0 (preferably pH 10.0 to 13.0), is a method for producing aggregates. In addition, since it is possible to obtain uniform fine particle crystals, it is most effective when used as a dispersant. When powdered calcium phosphate salts are used as they are, they tend to become strong aggregates as powder,
The particle size is non-uniform as an aggregate, and dispersion in the aqueous phase is quite difficult. Further, as an advantage of the method of forming calcium phosphate salts, a water-soluble neutral salt by-produced in calcium phosphate salts has an effect of preventing dissolution of a polymerizable monomer in water and an effect of increasing the specific gravity of an aqueous medium. That is.

The adjustment of the pH during the formation of the calcium phosphate salt in the present invention will be described.

When a polymerizable monomer composition containing a polymerizable monomer, a colorant, a charge control agent and the like is dispersed and granulated in an aqueous medium having a pH of 9.0 to 14.0, Since the colorant and the charge control agent are easily decomposed, dissolved and denatured into a strong alkali, the colorant and the charge control agent are dissolved depending on the time and temperature required for the production of the toner particles, and the desired charge control is performed. It is difficult to produce toner particles having properties and coloring power. In particular, C.I. I. Dyes classified as Solvent Yellow 162 are difficult to use because they are isomerized under alkali due to their structure and are accompanied by adverse effects such as sublimation and color change due to heat.

Further, when the colorant and the charge control agent are partially dissolved in the aqueous medium, the uniform dispersion of the polymerizable monomer composition is hindered, and the number of fine particles increases and particle aggregation occurs. Therefore, the particle size distribution of the obtained toner particles tends to be non-uniform. Thus, without adjusting the pH of the aqueous medium (ie, at pH 9.0 to 14.0),
C. I. Solvent Yellow 162 dye is used as a charge / dispersion aid for pigments,
Strict control of the production conditions was required to produce a yellow toner particle that suppressed color change and was stable in physical properties and particle size distribution.

According to the study by the present inventors, it has been found that the interface of the calcium phosphate salt as a dispersant contained in the aqueous medium is charged according to the pH of the aqueous medium. It was confirmed by measuring the potential that the interface of the calcium phosphate salt showed negative charge in an alkaline region and showed an equipotential point in a neutral region.

In the present invention, when producing the calcium phosphate salt, the pH of the aqueous medium is adjusted to 4.0 to 6.0, preferably 4.5 to 6.0, so that color reproducibility and toner can be improved. It has become possible to easily produce yellow toner particles having stable physical properties and particle size distribution.

The yellow toner produced by the production method of the present invention is obtained by granulating a polymerizable monomer composition in an aqueous medium,
In the polymerization step, the polar polymer or copolymer having a carboxyl group has an affinity, so that they are unevenly distributed in the outer shell of the droplet and enclose other compositions, have a so-called core / shell structure, and are stable. Expresses triboelectric charging ability.

However, under alkaline conditions, since the interface of the dispersant is negatively charged, the polar polymer or polar copolymer having a negative carboxyl group repels the charge. Or, the polar copolymer component is stable and hardly present in the outer shell, aggregation of droplets occurs during polymerization, and particle size distribution, particle morphology and surface properties, triboelectric charging ability, etc. are difficult to control, and toner Reproducibility tends to deteriorate in manufacturing.

The fact that the toner particles have a core / shell structure can be confirmed by examining the tomographic plane of the toner. Specifically, after sufficiently dispersing the toner particles in a room-temperature curable epoxy resin, the cured product is cured in an atmosphere at a temperature of 40 ° C. for 2 days, and the resulting cured product is ruthenium tetroxide and, if necessary, osmium tetroxide. After dyeing using a combination of the above, a flaky sample is cut out using a microtome provided with diamond teeth, and the sample is measured with a transmission electron microscope (TEM) to confirm the tomographic morphology of the toner. It was confirmed that the toner particles obtained in Examples described later had a core / shell structure.

Therefore, in the present invention, in order to solve such a problem, the pH of the aqueous medium is adjusted to 4.0 to 6.0 (preferably pH) when producing calcium phosphates.
4.5 to 6.0), and a polymerizable monomer, C.I. I. P
pigment Yellow 93 and a C.I. I. Solven
t A polymerizable monomer composition containing at least a dye classified as Yellow 162, a polar polymer or a polar copolymer containing a carboxyl group, and an initiator is dispersed and granulated in the aqueous medium, and a polymerizable monomer is obtained. Body composition particles are obtained.

Here, under conditions where the pH is lower than 4.0,
Since the calcium phosphate salt as a dispersant is rapidly solubilized, a predetermined dispersant concentration cannot be maintained, which is not preferable as a region used as a dispersant.

As the pH adjusting method in the present invention, for example, a water-soluble inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid is used. These inorganic acids may be used after being diluted with water to a predetermined concentration, if necessary. The amount of addition is determined so that the calcium phosphate salt is finally formed, or after the calcium phosphate salt is stably formed, finally becomes stable at pH 4.0 to 6.0 (preferably pH 4.5 to 6.0). The acid may be appropriately adjusted and added.

As a more preferable pH adjustment method, the pH after the calcium phosphate salt is stably formed by adding a predetermined amount to the aqueous phosphate solution to obtain a pH of 4.0 to 6.0 (preferably p-type).
H 4.5 to 6.0) is added in advance, and then an aqueous calcium salt solution is added to produce calcium phosphate salts.

The surface charge of the calcium phosphate salt in the pH range of 4.0 to 6.0 of the present invention is sufficiently stable by positive charge. Under this condition, the positively charged dispersant particles are stably adsorbed on the surface of the polymerizable monomer composition containing the polar polymer having a negative carboxyl group or its copolymer with a stable electrostatic force. Agglomeration and coalescence in the granulation and polymerization of the monomer composition are prevented, and a sharp particle size distribution of the resulting toner particles is achieved with good reproducibility. Further, in the produced toner particles, the negative polar polymer or polar copolymer is always stably localized on the toner particle surface, and the colorant is dispersed in the toner inside to form a core-shell structure. A yellow toner having high triboelectric charging ability and excellent in reproducibility of production and performance can be obtained.

Further, since the droplets granulated in this pH range are stably charged and dispersed in water until the end of the polymerization reaction, the morphology of the formed yellow toner is stable when it is very close to a true sphere. There is a characteristic that can be obtained with good reproducibility.

The circularity of the yellow toner particles thus formed can be determined by the dispersant concentration, the composition of the polymerizable composition, particularly the molecular weight of the polar polymer or copolymer having a carboxyl group,
Although there are slight changes in the addition amount, the yellow pigment, the dye ratio and the addition amount, the flow type particle image analyzer (FPI)
In A), it is 0.970 or more and less than 1.000. In addition, since the toner particles thus generated are stable throughout the granulation and polymerization steps, there is very little dirt or adhesion in the reaction tank, which has been a problem in the past, and a great advantage in terms of production efficiency. Having.

The morphology and surface properties of the generated toner particles vary depending on the electrophotographic system to be combined with the toner particles, and it is therefore desired that they can be arbitrarily controlled according to the system configuration used.

In general, toner particles having a shape close to a perfect sphere having excellent circularity and having a smooth surface are excellent in triboelectric charging ability and stable in charging, so that the toner characteristics are excellent in transferability in an electrophotographic system. Have.

In the present invention, since the toner particles can be constantly and stably manufactured in a state close to a true sphere in the form and surface properties of the toner particles, a yellow toner suitable for an electrophotographic system requiring high transferability as described above is used. This has the advantage that toner particles can be provided.

Since the toner particles produced in the present invention are in a state where calcium phosphate salts are adsorbed on the surface as it is, the pH of the aqueous medium containing the produced toner particles is adjusted to 1.0 to 3.0, and calcium phosphate is added. The salts are completely dissolved, and the toner particles are separated by filtration, washed repeatedly with water, and dried to obtain toner particles.

Here, the solubility of calcium phosphates with respect to pH is determined to be solubilized rapidly in a low pH acidic region with pH = 3.0 to 4.0 as a boundary region, and 100% soluble in a strongly acidic region of pH 3 or less. PH 1.0 or more to completely remove the dispersant particles from the toner particles.
An acid treatment at 3.0 is required.

In this acid treatment, as described above, C.I. I. Pigment Yellow 93 and C.I. I. Solvent Yellow
The dyes and charge control agents classified as w162 do not denature or solubilize as in an alkaline environment, and do not significantly affect the toner characteristics.

The polymerizable monomers used in the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-methoxystyrene and p-methylstyrene.
Styrene monomers such as ethylstyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, Stearyl acrylate, acrylic acid 2-
Chloroethyl, acrylates such as phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-methacrylic acid Ethylhexyl, stearyl methacrylate, phenyl methacrylate,
Examples include methacrylates such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, and monomers such as acrylonitrile, methacrylonitrile, and acrylamide. These monomers can be used alone or as a mixture.

Further, a polar polymer and a polar copolymer having a carboxyl group are added to the monomer system of the polymerization method toner according to the present invention to carry out polymerization.

The polar polymers and polar copolymers that can be used in the present invention are exemplified below.

Polar polymers or polar copolymers using unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and other unsaturated dibasic acids and unsaturated dibasic acid anhydrides, and unsaturated or saturated polyesters. .

These polar polymers or polar copolymers are preferably used in an amount of 1 to 35 parts by mass, more preferably 5 to 20 parts by mass, per 100 parts by mass of the polymerizable monomer. If it exceeds 35 parts by mass, the viscosity is too high and granulation is unstable.

As the polymerization initiator, for example, 2,2′-
Azobis- (2,4-dimethylvaleronitrile), 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butylhydro Peroxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,
4-tert-butylperoxycyclohexyl) propane,
A peroxide initiator such as tris- (t-butylperoxy) triazine, a polymer initiator having a peroxide in a side chain, a persulfate such as potassium persulfate and ammonium persulfate, and hydrogen peroxide are used. You.

The polymerization initiator is preferably added in an amount of 0.5 to 20 parts by mass per 100 parts by mass of the polymerizable monomer, and may be used alone or in combination.

In the present invention, in order to control the molecular weight, a known crosslinking agent or chain transfer agent may be added. The preferable addition amount is 0.001 to 15 parts by mass per 100 parts by mass of the polymerizable monomer. Parts by weight.

Preferred examples of the crosslinking agent include divinylbenzene, divinylnaphthalene and aromatic divinyl compounds which are derivatives thereof, other ethylene glycol dimethacrylate, diethylene glycol methacrylate, triethylene glycol methacrylate, trimethylolpropane triacrylate, allyl methacrylate, tert-butylaminoethyl methacrylate,
Tetraethylene glycol dimethacrylate, 1,3-
All divinyl compounds such as diethylenic carboxylic acid esters such as butanediol dimethacrylate, N, N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, and compounds having three or more vinyl groups are used alone or as a mixture. Can be

In the present invention, a charge control agent can be added to the toner particles for the purpose of controlling the chargeability of the toner.

Examples of the negative charge control agent include metal-containing salicylic acid compounds, metal-containing monoazo dye compounds, styrene-acrylic acid copolymers, imidazole derivatives, styrene-methacrylic acid copolymers (N, N'-diarylurea derivatives). ), Carrick's arene and the like.

Examples of the positive charge controlling agent include denatured products such as nigrosine and fatty acid metal salts; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate;
Quaternary ammonium salts such as tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts, which are analogs thereof, lake pigments thereof, triphenylmethane dyes, and lake pigments thereof. Acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorgano such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Tin oxide; dibutyltin borate,
Diorganotin borates such as dioctyl tin borate and dicyclohexyl tin borate; these can be used alone or in combination of two or more.

The dispersant used in the present invention is a calcium phosphate salt, as described above. Specifically, the dispersant is calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, hydroxyapatite, or a mixture of a plurality thereof. is there. This dispersant is preferably used in an amount of 0.2 to 20 parts by mass based on 100 parts by mass of the polymerizable monomer.

For finely dispersing these dispersants, a surfactant may be used in an amount of 0.001 to 0.1 part by mass based on 100 parts by mass of the polymerizable monomer. This is to promote the desired action of the dispersant, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium lariurate, Potassium stearate and calcium oleate.

The hydroxyapatite or calcium phosphate may be used in the form of a powder as it is, but it is preferable to use a substance such as sodium phosphate and calcium chloride to generate hydroxyapatite or calcium phosphate in water and use the same. . When this method is used, a very fine salt is obtained and a stable suspension state is obtained, so that the granulation property is good.

The releasing component and the low energy fixing component used in the present invention include paraffin / polyolefin waxes and modified products thereof, for example, oxides and grafted products, higher fatty acids and metal salts thereof. , Amide waxes, and ester waxes, for example, polyfunctional polyester compounds having a tertiary or / and / or quaternary carbon and obtained from a difunctional or higher alcohol compound or a carboxylic acid compound, primary or / and secondary A polyfunctional polyester compound having carbon and obtained from a difunctional or higher functional alcohol compound or carboxylic acid compound, and 3
Monofunctional ester compounds having a quaternary or / and quaternary carbon and the like can be mentioned.

In a polymerization method in which toner particles are directly obtained by polymerizing a mixture containing a polymerizable monomer, a colorant and a release agent, in a toner production method, the release agent is used in an amount of 100% by weight of the polymerizable monomer. It is preferable to use 1 to 40 parts by mass, more preferably 3 to 35 parts by mass, per part. More preferably, 5 to 30 parts by mass are used.

As the substance used for adjusting the pH in the present invention, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like are used as water-soluble inorganic acids. Examples of the base include alkaline substances such as ammonium hydroxide, potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, sodium phosphate, and hydrates thereof. Alternatively, an aqueous solution thereof is used. These substances can be diluted as necessary and used as an aqueous solution having a specific concentration.

Examples of the external additives of the toner usable in the present invention include oxides such as alumina, titanium oxide, silica, zirconium oxide, and magnesium oxide, as well as silicon carbide, silicon nitride, boron nitride, and nitrogen. Aluminum oxide, magnesium carbonate, organosilicon compounds, and the like.

Further, the fine powder is preferably subjected to a hydrophobic treatment in order to reduce the dependence of the charge amount of the toner on the environment such as temperature and humidity and to prevent the toner from being released from the toner surface. Examples of the hydrophobizing agent include coupling agents such as silane coupling agents, titanium coupling agents, and aluminum coupling agents, and oils such as silicone oils, fluorine-based oils, and various modified oils.

Among these known external additives, it is preferable to select silica, alumina, titania or a double oxide thereof in order to improve charge stability, developability, fluidity and storage stability. Among them, silica is particularly preferable because the coalescence of primary particles can be controlled to some extent arbitrarily by oxidizing conditions such as a starting material or temperature. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide and an alkoxide, and a so-called wet silica produced from an alkoxide, a water glass and the like, and a dry silica called a fumed silica can be used. However, dry silica having less silanol groups on the surface and in the interior of the silica fine powder and having less production residues such as Na ₂ O and SO ₃ ^2- is preferred. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. Is also included.

The external additive is added in an amount of 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner in order to stabilize the charge of the toner, stabilize the bulk density, and the stability of being left under high humidity. Preferably, these external additives can be used in combination of two or more kinds. Hereinafter, external additives that are preferably used in combination separately will be described.

In order to improve the transfer property and / or the cleaning property, it is preferable to further add inorganic or organic particles having a primary particle diameter of 50 nm or more (preferably having a specific surface area of less than 50 m ² / g). One. For example, spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles are preferably used.

In the toner of the present invention, other additives such as lubricant powders such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, silicon carbide Powder,
Abrasives such as strontium titanate powder; anti-caking agents such as titanium oxide powder and aluminum oxide powder; or conductivity imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder, and organic fine particles of opposite polarity Also, a small amount of inorganic fine particles can be used as a developing property improver.

The toner according to the production method of the present invention can be generally used as a one-component or two-component developer in any developer. For example, when used as a one-component developer, there is a method in which a blade and a fur brush are used to forcibly triboelectrically charge the toner with a developing sleeve and cause toner to adhere to the sleeve, thereby conveying the toner.

On the other hand, when used as a commonly used two-component developer, a carrier is used as a developer together with the toner of the present invention. The carrier used in the present invention is not particularly limited, but is mainly composed of a single ferrite and a composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, and chromium. The carrier shape is also important because saturation magnetization and electric resistance can be controlled in a wide range. For example, it is preferable to select a spherical shape, a flat shape, an irregular shape, and the like, and to further control the fine structure of the carrier surface state, for example, the surface unevenness. . Generally, the above inorganic oxide is calcined,
A method of coating the resin after forming carrier core particles in advance by granulation is used.However, from the viewpoint of reducing the load on the toner of the carrier, the inorganic oxide and the resin are kneaded and then pulverized. , A method of obtaining a low-density dispersion carrier by classification, and a method of directly obtaining a polymerized carrier for obtaining a spherical dispersion carrier by suspension-polymerizing a kneaded product of an inorganic oxide and a monomer in an aqueous medium are also used. It is possible to

A system in which the surface of the carrier is coated with a resin or the like is particularly preferable. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a solvent, coating and adhering to a carrier, and a method of simply mixing with a powder can be applied.

The substance to be fixed to the carrier surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal compound of ditersharry butylsalicylic acid, and styrene. Resin, acrylic resin, polyacid, polyvinyl butyral, nigrosine, amino acrylate resin, basic dyes and lakes thereof, silica fine powder, alumina fine powder, etc. are suitable for use alone or in combination, but are not necessarily limited to this. Not done.

The amount of the compound to be treated is generally 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, per 100 parts by mass of the carrier.

The average particle size of these carriers is 10 to 100.
μm, preferably 20 to 50 μm.

In a particularly preferred embodiment, Cu—Zn—
Fe ternary ferrite, the surface of which is a combination of a resin such as a fluorine resin and a styrene resin, for example, polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene and styrene-methyl methacrylate resin; 90:10 to 20:80, preferably 7 to 10;
A mixture having a ratio of 0:30 to 30:70,
Coated ferrite carrier having the above average particle diameter, in which 0.01 to 5% by mass, preferably 0.1 to 1% by mass is coated and carrier particles of 250 mesh pass and 400 mesh on are 70% by mass or more. Can be As the fluorine-based copolymer, a vinylidene fluoride-tetrafluoroethylene copolymer (10:90 to 90: 1)
0). Examples of the styrene copolymer include styrene-2-ethylhexyl acrylate (20:80 to 80:
20), styrene-2-ethylhexyl acrylate-methyl methacrylate (20-60: 5-30: 10-5)
0) is exemplified.

The coated ferrite carrier has a sharp particle size distribution, provides favorable triboelectrification to the toner of the present invention, and has the effect of improving electrophotographic properties.

When a two-component developer is prepared by mixing with the toner of the present invention, the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Then usually good results are obtained. If the toner concentration is less than 2% by mass, the image density is low and cannot be used practically. If the toner concentration is more than 15% by mass, fog and scattering in the machine are increased, and the useful life of the developer is shortened.

Further, the magnetic properties of the carrier are preferably as follows. 79.58 kA / m after magnetic saturation
The magnetization intensity at (1000 Oe) needs to be 30 to 300 emu / cm ³ . In order to achieve higher image quality, preferably 100 to 2
It is preferably 50 emu / cm ³ . 300 emu /
If it is larger than cm ^3, it becomes difficult to obtain a high quality toner image. If it is less than ³⁰ emu / cm ³ , the magnetic binding force is reduced, so that carrier adhesion is likely to occur.

The gist of the method for producing the toner of the present invention is as follows.

That is, C.I. I. P
pigment yellow 93 and C.I. I. Solvent Yellow 162 and at least both dyes and a polar polymer or polar copolymer having a carboxyl group, a release agent, a charge control agent, a polymerization initiator, and other additives. A monomer composition uniformly dissolved or dispersed by, for example, is prepared. On the other hand, when a phosphate aqueous solution and a calcium salt aqueous solution are mixed to form calcium phosphate salts, the pH of an aqueous medium containing the calcium phosphate salts is adjusted to a dilution of a water-soluble inorganic acid such as hydrochloric acid, sulfuric acid, and nitric acid. To adjust the pH to 4.0-6.0. In pH adjustment, the diluted acid may be added after the calcium phosphate salts are formed by mixing the two components, or may be added in advance to the aqueous phosphate solution or the aqueous calcium salt solution before the two components are mixed, and then the aqueous solution of the calcium salt is added. Alternatively, a calcium phosphate salt may be precipitated by mixing a phosphate aqueous solution. It is advantageous to produce the calcium phosphates in a dispersion granulator such as a homomixer or a homogenizer, but an aqueous dispersion of calcium phosphates that has been separately formed may be introduced into the dispersion granulator. .

The above-mentioned monomer composition is charged into an aqueous medium containing calcium phosphates whose pH has been adjusted in this way, dispersed, and granulated. Thereafter, the pH and the action of the calcium phosphate salt, which is a dispersion stabilizer, stabilize the monomer-based particle state and stir the monomer-based particles to prevent sedimentation. Polymerization is stable with no accompanying particle aggregation and coalescence. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C.

Further, the temperature may be raised in the latter half of the polymerization reaction, and in order to remove unreacted polymerizable monomers and by-products which cause odor at the time of fixing the toner, a part of the reaction is performed in the latter half of the reaction or at the end of the reaction. Alternatively, the aqueous medium may be distilled off. After completion of the reaction, the resulting toner particles are treated with a water-soluble inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid as described above to adjust the pH to 1.0 to 3.0 for a predetermined time in order to remove calcium phosphate salts. After sufficiently washing with water, the toner particles are collected by filtration, dried, and classified as necessary to obtain yellow toner particles.

The respective measuring methods used in the present invention will be described below.

(1) Measurement of Particle Size Distribution as Judgment Criteria for Aggregation and Coalescence of Toner Particles A Coulter Counter TA-II type (manufactured by Coulter Co.) is used as a measuring device, and a number average distribution and a volume average distribution are output. Interface (made by Nikkaki) and CX-
1 Connect a personal computer (manufactured by Canon)
As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride.

The measuring method is as follows.
In 50 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 0.5 to 50 mg of a measurement sample is further added. The electrolyte in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser,
According to the Coulter Counter TA-II, a 100 μm aperture is used as an aperture, and 2 to 40.
The volume average distribution and the number average distribution are determined by measuring the particle size distribution of the μm particles.

From the obtained volume average distribution and number average distribution, a weight average particle diameter D ₄ and a number average particle diameter D ₁ are obtained.

From the D ₄ and D ₁ values, D ₄
/ D ₁ is calculated and used as a criterion for aggregating and coalescing of the generated toner particles. That is, when the value of D ₄ / D ₁ increases, the toner particles form secondary aggregates or seem to be united. When the value of D ₄ / D ₁ approaches 1.0, the particle size distribution of monodispersion is increased. Can be determined to approach.

(2) Amount of triboelectric charge of toner particles The amount of triboelectric charge is determined by leaving the toner and the carrier all day and night under ambient conditions of normal temperature and normal humidity (23 ° C./60%), and then, based on the blow-off method, as follows. The charge amount was measured.

FIG. 1 is an explanatory view of an apparatus for measuring the amount of triboelectric charge of toner. First, in a metal measuring container 2 having a screen 3 of 500 mesh at the bottom, a mixture of a toner and a carrier having a mass ratio of 1:49 to be measured for triboelectric charge is put into a polyethylene bottle having a volume of 50 to 100 ml, and
Shake by hand for 5 to 10 minutes, and add about 0.5 mixture (developer).
Add 1.5 g and cover with metal lid 4. At this time, the mass of the entire measurement container 2 is weighed and defined as W ₁ (g). Next, the suction device 1 (at least a portion in contact with the measurement container 2 is an insulator)
In the above, the pressure of the vacuum gauge 5 is adjusted to 250 mmAq by adjusting the air volume control valve 6 by suctioning through the suction port 7. In this state, suction is sufficiently performed, preferably for 2 minutes, to remove the toner by suction. The potential of the electrometer 9 at this time is set to V (volt).
Here, reference numeral 8 denotes a capacitor, whose capacity is C (μF). In addition, the mass of the whole measurement container after suction is weighed and W
₂ (g). Amount of triboelectric charge of this toner (μC / g)
Is calculated as follows:

[0115]

(Equation 1)

(3) Flow type particle image analyzer (FPI)
Measurement of circularity in A) The circularity in the present invention is used as a simple method for quantitatively expressing the shape of particles, and in the present invention, a flow particle image analyzer FPIA- made by Toa Medical Electronics Co., Ltd. 100
The measurement is performed using 0, and the value obtained from the following equation is defined as circularity.

As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzenesulfonate, is added as a dispersant to 100 to 150 ml of water from which impurity solids have been removed in advance. , And further, the measurement sample is set to 0.
Add about 1-0.5 g. The suspension in which the sample is dispersed is subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the shape of the toner is measured by the above-mentioned apparatus with the concentration of the dispersion being 3000 to 10,000 / μl.

[0118]

(Equation 2)

The degree of circularity in the present invention is an index of the degree of unevenness of toner particles.
000, and the degree of circularity becomes smaller as the surface shape becomes more complicated.

(4) Evaluation of Production Reproducibility of Toner Particles A toner was repeatedly produced 10 times under the same toner formulation and production conditions, and the particle size distribution width (D ₄ / D ₁ ) and friction of each produced toner particle were determined. After measuring the charge amount, the circularity in FPIA, and the transfer efficiency, the standard deviation SD was obtained and used as a parameter of reproducibility.

[0121]

(Equation 3)

In this parameter, as the numerical value is smaller,
This shows that the toner production method is excellent in production reproducibility with little variation in particle size distribution width, triboelectric charge amount and circularity transfer efficiency.

(5) Measurement of Transfer Efficiency of Toner Particles The transfer efficiency was determined by taking a toner image (image density 1.4) formed on a photosensitive drum under a normal environment with a transparent adhesive tape, and collecting the image. The density (D1) is measured using a Macbeth densitometer or a color reflection densitometer (eg, Color refle).
Ction densitometer X-RITE
404A manufacturedby X-Ri
te Co. ). Next, a toner image is formed on the photosensitive drum again, the toner image is transferred to a recording material, and the toner image transferred on the recording material is collected with a transparent adhesive tape,
The image density (D2) is measured similarly. It is calculated as follows from the obtained image densities (D1) and (D2).

Transfer efficiency (%) = (D2 / D1) × 100

(6) Measurement of Hue Reproducibility of Images on Paper and on Transparency First, under normal environment, the amount of toner loaded on paper and on the transparency film was 0.6 mg / mg.
A solid image sample adjusted to cm ² is prepared using a two-component color copying machine (Canon full color copying machine CLC700).

The hue measurement on paper is based on the CIE LAB.
Degree field of view, Color using illuminant D ₆₅ Reflec
Tion Densitometer (X-RITE 9
38 Spectrodensitometer, X-R
ITE Co. Manufactured). The hue measurement of the transmission image on the transparency film is based on the actual transmission image (the distance between the OHT projector and the transmission screen of 2) through an OHT projector (Model # 9550 manufactured by 3M).
m) 2m away from the translucent screen
Ric Spectrophotometer (PR-
650 Photo Research).

The “hue reproducibility” in the present invention means “on hue (h)
₁ ^*) And on transparency (h _Two ^*) And the hue angle difference
The hue angle difference (Δh^*)But
The smaller the value, the better the hue reproducibility.

[0128]

(Equation 4)

(7) Evaluation of Weather Resistance Under a normal environment, a solid image sample (on paper) adjusted to a toner loading of 0.6 mg / cm ² was measured using a two-component color copying machine (Canon full color copying machine CLC700). prepare.

These image samples were exposed under the following equipment and conditions, and the image densities of the samples were successively measured with Color.
Reflection Densitometer
(X-RITE938 Spectrodensito
meter, X-Rite Co. Manufactured), and the weather resistance was evaluated based on the magnitude of the decrease in image density.

Therefore, it is judged that the weather resistance is better for a sample having a smaller image density decrease (ΔD).

Measurement device: Ultraviolet-ray A
auto FadeMeter Test Style: FAL-AU (Suga test
Instruments Co. Ltd) Light source: Ultraviolet-ray C
arbon ArcLamp Temperature / humidity: 63 ° C / 50% Exposure time: 160 hours

[0133]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention in any way. The number of parts in the following formulations is parts by weight unless otherwise specified.

Example 1 1000 parts of ion-exchanged water
0.1 M prepared with industrial grade sodium phosphate
-510 parts of an aqueous solution of sodium phosphate and an appropriate amount of a 1M aqueous solution of hydrochloric acid are added so that the pH after the addition of the aqueous solution of calcium chloride is 5.3, and the mixture is heated to 60 ° C. 12,000 rpm using
And stirred. To this, 75 parts of a 1.0 M calcium chloride aqueous solution prepared with industrial grade calcium chloride was gradually added to obtain an aqueous medium having a pH of 5.3 containing hydroxyapatite which is a calcium phosphate salt.

On the other hand, 80 parts of styrene 20 parts of n-butyl acrylate monomer 10 parts of saturated polyester resin I. Pigment Yellow 93 2.5 parts C.I. I. Solvent Yellow 162 3 parts ・ Di-tert-butylsalicylate aluminum compound 2 parts ・ Microcrystalline wax (sp. = 65 ° C.) 20 parts The above formulation was heated to 60 ° C. Was uniformly dissolved and dispersed at 12000 rpm. Into this, 5 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 10,000 rpm for 10 minutes with a TK homomixer at 60 ° C. in an N ₂ atmosphere. The product was granulated. Thereafter, the temperature was raised to 70 ° C. while stirring with a paddle stirring blade, and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer is distilled off under reduced pressure, and after cooling,
Hydrochloric acid was added to completely dissolve the hydroxyapatite, filtered, washed with water and dried to obtain polymerizable particles.

Next, polymer particles were repeatedly obtained four times under the same formulation and the same manufacturing conditions as a total, and each time, polymer particle size distribution width (D ₄ / D ₁ ), triboelectric chargeability, circularity in FPIA, and transfer efficiency were measured. Each item was measured, and the average value and standard deviation SD value of those values were determined. Furthermore, weather resistance and hue reproducibility were also measured. As a result, in each item, the average value showed a preferable value, and the result that the standard deviation was small was obtained. Table 1 shows the results.

Further, after granulation at the same formulation, for example, at 50 to 60 ° C., polymerization is carried out at the same temperature for 3 to 7 hours.
The polymerization is carried out in accordance with various reaction sequences (combination of temperature and time) such as raising the temperature to 10 ° C. so that the reaction time becomes a total of 10 hours. In the case where the values were changed, a toner having excellent particle size distribution width, triboelectric charging ability, and the like was obtained.

[Example 2] The pH of an aqueous medium containing hydroxyapatite produced by changing the amount of 1M hydrochloric acid aqueous solution added was changed to 4.1, and C.I. I. Pigment Yellow 93
4 parts, C.I. I. Solvent Y
Except that 2.5 parts of 162 were added, polymer particles were obtained in the same manner as in Example 1. Further, the production was repeated four times in total, thereby obtaining polymer particles. The deviation was calculated.

As a result, in each item, the average value showed a preferable value, and the standard deviation was small. Table 1 shows the results.

Example 3 The pH of an aqueous medium containing hydroxyapatite formed by changing the amount of 1M aqueous hydrochloric acid added was changed so as to be 6.0, and C.I.
I. Pigment Yellow 93 2.5 parts,
And C.I. I. Solvent Yellow 162
Polymer particles were obtained in the same manner as in Example 1 except that 2.5 parts were added, and the production was repeated four times in total to obtain polymer particles, and the average value and standard deviation of each item were calculated. did.

As a result, in each item, the average value showed a preferable value, and the standard deviation was small. Table 1 shows the results.

Example 4 The pH of an aqueous medium containing hydroxyapatite formed by changing the amount of 1M aqueous hydrochloric acid added was changed so as to be 4.5. I.
Pigment Yellow 93 5 parts, C.I. I. S
Polymer particles were obtained in the same manner as in Example 1 except that 1625 parts of Yellow Yellow was used, and the production was repeated four times in total to obtain polymer particles, and the average value and standard deviation of each item were calculated. did.

As a result, in each item, the average value showed a preferable value and the standard deviation was small. Table 1 shows the results.

[Comparative Example 1] Polymer particles were obtained in the same manner as in Example 1 except that no 1M aqueous hydrochloric acid solution was used and the pH was not adjusted. The production was repeated to obtain polymer particles, and the average value and standard deviation of each item were calculated. The standard deviation of each item was large, and it was found that the stability and reproducibility of the produced toner particles when the production was repeated under the same prescription and the same conditions were not as good as those in the examples.

Further, for the alkali-isomerized dye,
Reddish stains particularly adhered to the upper part of the reaction tank, and poor results were obtained with respect to the stains.

Further, in the same manner as in Example 1, polymerization was carried out according to various reaction sequences (combinations of temperature and time). As a result, particularly when the reaction is carried out for a long time at a relatively high temperature at a low polymerization conversion rate, aggregates of the produced particles are likely to be generated, stains and adhesion in the reddish reaction tank are increased, and the particle size distribution is increased. A toner having a considerably large width and unstable triboelectric charging ability was obtained.

[Comparative Example 2] The pH of the produced toner particles at the time of acid washing was 3.8. I. Pigment
Yellow 93 only 7 parts, C.I. I. Solv
Except that ent Yellow 162 was not used, polymer particles were obtained in the same manner as in Example 1, and the production was repeated four times under these conditions to obtain polymer particles, and the average value of each item was obtained. And the standard deviation. In this case, the average value of the triboelectric charge amount and the transfer efficiency was low, and the standard deviation in all the items was large, so that the stability and reproducibility of the generated toner particles were found to be poor.

Comparative Example 3 C.I. I. Pigment Y
yellow 93 1 part, C.I. I. Solvent
Instead of Yellow 162, C.I. I. Solven
t Yellow 163 Except that a combination with 6 parts was used, polymer particles were obtained in the same manner as in Example 1, and the production was repeated four more times under these conditions to obtain polymer particles. The average value and standard value for each item were obtained. Deviation was determined. As a result, it was found that weather resistance, hue reproducibility and triboelectric charge amount were not preferable.

The evaluation of the reaction tank contamination in the above Examples and Comparative Examples was performed as follows.

[Evaluation of Reaction Tank Stain] A toner was repeatedly manufactured four times under the same toner prescription and manufacturing conditions, and the reaction tank stain was visually observed and evaluated according to the following criteria. A: No problem in repeated production four times. B: Almost no problem in repeated production four times. C: It becomes gradually dirty in repeated production. D: Each time, the reaction tank becomes dirty.

[0152]

[Table 1]

[0153]

According to the present invention, yellow toner particles having excellent granulation / polymerization stability and reproducibility can be produced. Furthermore, the resulting toner particles are excellent in dispersibility and transparency of yellow pigment, and are excellent in stability and reproducibility in terms of particle size distribution, triboelectrification, particle morphology and surface control, and transfer efficiency. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for measuring a triboelectric charge amount of a toner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction machine 2 Measurement container 3 Conductive screen 4 Lid 5 Vacuum gauge 6 Air flow control valve 7 Suction port 8 Condenser 9 Electrometer

Claims (9)

[Claims] 1. Styrene-acrylic resin or styrene-
In a toner binder resin mainly composed of methacrylic resin, C.I. I. Pigment Yellow 93
Pigments classified as C.I. I. Solvent Yellow
ow 162, and has a circularity of 0.97 as measured by a flow type particle image analyzer (FPIA).
A yellow toner having a value of 0 to less than 1.000. 2. The yellow toner according to claim 1, wherein the content of each of the pigment and the dye satisfies the following formula with respect to 100 parts by mass of the toner binder resin. The pigment content is A (parts by mass), and the dye content is B (parts by mass).
A = 0.5-4 B = 5-1.5 A / B = 0.5-3 3. The pH of an aqueous medium containing calcium phosphates obtained by mixing an aqueous solution of a phosphate and an aqueous solution of calcium salt is adjusted to 4.0 to 6.0, and at least polymerizable water is added to the aqueous medium. Dispersing a monomer, a colorant, a polar polymer or polar copolymer having a carboxyl group and a polymerizable monomer composition having a polymerization initiator to form particles of the polymerizable monomer composition, In an aqueous medium, polymerizable monomers contained in the particles are polymerized to form toner particles, and the pH of the aqueous medium is adjusted to 1.0 to 3.0 to dissolve calcium phosphates. A method for producing a yellow toner, comprising the step of separating toner particles after the process, wherein the polymerizable monomer comprises a styrene monomer and an acrylic or methacrylic monomer; I. Pigment Yellow 9
3 and C.3. I. Solvent Yel
low 162 and a flow type particle image analyzer (F
The circularity measured by PIA) is 0.970 or more and 1.00
A method for producing a yellow toner, which is less than 0. 4. The method for producing a yellow toner according to claim 3, wherein each content of the pigment and the dye satisfies the following formula with respect to 100 parts by mass of the toner binder resin. 5. The yellow toner according to claim 3, wherein a phosphate aqueous solution and a calcium salt aqueous solution which become a pH 9.0 to 14.0 aqueous medium containing calcium phosphates when mixed are used. Production method. 6. The yellow toner according to claim 3, wherein a phosphate aqueous solution and a calcium salt aqueous solution, which become an aqueous medium containing calcium phosphates and have a pH of 10.0 to 13.0 when mixed, are used. Production method. 7. The method for producing a yellow toner according to claim 3, wherein the calcium phosphate salt is hydroxyapatite. 8. The yellow toner according to claim 3, wherein the pH of the aqueous medium before dispersing the polymerizable monomer composition is 4.5 to 6.0. Manufacturing method. 9. A p-type aqueous medium comprising a water-soluble inorganic acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.
The method for producing a yellow toner according to any one of claims 3 to 8, wherein H is adjusted.