JP2000075552A - Yellow toner and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner excellent in transparency transmittance, which exhibits hue having excellent balance on an image having a low glossiness by incorporating a binding resin with a yellow colorant having a specified structural formula and a salicylic acid-metal compound. SOLUTION: The toner contains a binding resin, a yellow colorant of the formula and a salicylic acid-metal compound. That is to say, the coloring compound (yellow colorant) excellent in its transparency and dispersibility is used. The coloring compound expressed by the formula has primary particle sizes of 0.01-0.70 μm, preferably, 0.01-0.40 μm and, more preferably, has a coefficient of variation of the particle size number distribution of <=60%. When the particles having primary sizes less than 0.01 μm are used, the light resistance of the particles remarkably decreases and, furthermore, it becomes difficult to handle and to electrify the particles. Further, when the particles having primary particles sizes of >=0.70 μm and a coefficient of variation of the particle size number distribution of >=60% are used, the coagulation of the colorant easily occurs at the time of the production of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yellow toner for developing an electrostatic image formed in an electrophotographic method, an electrostatic printing method or the like, and a method for producing the same. More specifically, the present invention relates to a yellow toner obtained by polymerizing a monomer composition containing at least a yellow colorant, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, digital full-color copying machines and printers have been put to practical use, and high-quality images excellent in color reproducibility without color unevenness as well as in resolving power and gradation can be obtained.

In a digital full-color copying machine, a color image original is separated into colors by B (blue), G (green), and R (red) color filters, and then has a dot diameter of 20 μm to 70 μm corresponding to the original image. Latent image is Y (yellow), M (magenta), C (cyan), B
(Black) Each color developer is developed using the subtractive color mixing action. However, it is necessary to transfer a larger amount of developer from the photoconductor to the transfer material compared to a black and white copier, and further higher image quality in the future In order to cope with such a tendency, a demand for a finer particle size of the developer corresponding to finer dots is expected.

However, when the toner particle size is reduced in accordance with the demand for higher image quality, the resolution and the sharpness of a full-color image will certainly be satisfactory, but it has been found that various effects are caused by the finer particles. Have been.

[0005] In addition, when the particle size of the toner is reduced, there arises a problem that the charging characteristics are easily affected by the uneven distribution of the colorant.

Accordingly, there is a demand for a toner having better dispersion of each color of the color toner than before and having well-balanced hue and spectral reflection characteristics and sufficient saturation.

Further, when the particle size of the toner is reduced, light becomes more liable to be scattered, so that the chromaticity, lightness, density, etc. of the image change, and a color configuration different from that of the prior art is required. Also occurs.

[0008] This is remarkably exhibited when an image is obtained in accordance with the new user orientation accompanying the spread of printers in recent years, that is, a tendency to prefer an image similar to other matte printed matter such as photoengraving printing.

That is, in the prior art, it is necessary that the fixed toner is almost in a state of almost complete melting so that the shape of the toner particles cannot be discriminated so that the toner does not irregularly reflect light and hinder color reproduction. In some cases, in a color image in which several types of toner layers are superimposed, the upper toner layer needs to have transparency that does not interfere with the lower toner layer.

Based on this idea, Japanese Patent Laid-Open No. 59-26
No. 757, JP-A-63-70271, JP-A-1-273072, JP-A-2-293860, JP-A-6-11898, etc., each yellow / magenta / cyan / black. Various other configurations have been proposed.

However, in order to obtain an image having no gloss difference from other printed matter such as photoengraving printing, it is absolutely necessary to fix the gloss value to a value close to the glossiness of paper. Since there is no such situation, the influence of the scattered light of the fine particle toner becomes remarkable, and the color space configuration of the present invention has become insufficient.

Further, if the resin of the toner is designed so that the toner particles do not completely melt,
It has been found that the toner particles cannot be completely melted even on the transparency film, so that the transmitted light is scattered and the color reproduction area is reduced.

Further, it has been found that the hue angle also changes, so that it becomes impossible to obtain a desired color.

Particularly, for yellow, human sensitivity to a change in hue angle is remarkable, so that a change in color angle of transmitted light is not preferred.

In the printer market, there are many machines that output an image in which black characters are mixed. However, in the prior art, there is a difference in the amount of toner applied between the black characters and the color image, so that the difference in glossiness is low. This results in a high gloss color image that appears "emerging".

Further, since light on the image surface is scattered to lower the image density, it has been found that when the coloring power of the toner is increased as a countermeasure, fog becomes noticeable.

That is, since the portion where the toner is scattered at the time of fixing is given a relatively sufficient amount of heat, the glossiness of the image is increased, and as a result, the image density of the scattered portion is increased. And this makes the fog noticeable.

As described above, at present, there is no color toner that can satisfy all of the various problems necessary for obtaining a glossless printed matter.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to provide a yellow toner which solves the above-mentioned drawbacks and which can obtain extremely clear colors on an image having low glossiness, and a method for producing the same.

That is, an object of the present invention is to provide a toner having a balanced hue at a low gloss level and excellent transparency and a method for producing the same.

Another object of the present invention is to provide a yellow toner for use in a full-color image having a uniform image quality without any discomfort even in an image in which black characters are mixed, and a method for producing the same.

Another object of the present invention is to provide a yellow toner having excellent chargeability and a method for producing the same.

[0023]

The present invention relates to a yellow toner containing at least a binder resin, a yellow colorant represented by the following structural formula, and a metal salicylate compound.

[0024]

Embedded image

As a result of intensive studies, the present inventor has found that by using a specific metal compound as a dispersant for the colorant of the present invention which is excellent in color development and transparency, an excellent dispersion state which has not been obtained conventionally can be obtained. The inventors have found that the toner can be obtained even in a toner state, and have reached the present invention.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One of the features of the present invention is that the colorant compound (I) has excellent transparency and dispersibility of the colorant itself.
Is used.

The coloring agent of the present invention is generally C.I. I. Pi
g. It is a colorant classified as Yellow128, and exhibits excellent coloring power when added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the toner binder resin.

The coloring agent of the present invention can be combined with other conventionally known coloring agents for improving the tint. However, the coloring agent of the present invention may be added within a range that does not impair the transparency of the coloring agent of the present invention. Preferably, the amount is less than 20 parts by weight based on 100 parts by weight of the coloring agent of the present invention.

In addition, the present inventor has studied conditions under which the hue angle of the transmitted light of a transparency image whose surface is not completely melted does not change the most, and as a result, a colorant having a specific primary particle size is determined. It has been found that it is possible to suppress to some extent by selecting.

Conventionally, from such a viewpoint, for example, Japanese Patent Laid-Open No.
Japanese Patent No. 42265 describes the primary particle size of a quinacridone pigment, and JP-A-4-204547 describes carbon black as an example for the purpose of giving gradation.

However, when the present invention is simply applied to a transparency image in which the surface is not completely melted as in the present invention, the hue angle and the color gamut are changed, particularly in yellow transmitted light, although it is suppressed as compared with the conventional case. I will.

That is, in the present invention, the transparency of the pigment itself is indispensable from the above-mentioned viewpoints, and the pigment of the present invention is also required in terms of transparency and ease of controlling the dispersion state to a fine particle size. The agent exhibits excellent properties.

In the present invention, the compound (I) has a primary particle size of 0.01 to 0.70 μm, preferably 0.01 to 0.7 μm.
It is preferably 0.40 μm, and more preferably 60% or less as a variation coefficient of the particle size distribution.

When the primary particle size of the compound (I) is less than 0.01 μm, not only the light resistance thereof is extremely lowered, but also
This has an adverse effect on the handling and charging properties during manufacturing.

The compound (I) has a primary particle size of 0.70
If the coefficient of variation of μm and the particle size distribution exceeds 60%, aggregation of the colorant is likely to occur during production, and the hue angle and color gamut of the transmitted light of the transparency image will be different from those on paper. Also, the transmitted image becomes dark.

The particle size of the colorant in the present invention is specifically measured by the following method.

First, after sufficiently dispersing the toner in an epoxy resin curable at room temperature, the cured product is cured in an atmosphere at a temperature of 40 ° C. for 2 days, and the cured product is used together with ruthenium tetroxide and, if necessary, osmium tetroxide. After dyeing, a flaky sample was cut out using a microtome provided with diamond teeth, and the tomographic morphology of the toner was measured using a transmission electron microscope (TEM).

Then, 100 obtained toner cross-sectional images are randomly sampled, and the image information is introduced into an image analyzer (Luzex3, manufactured by Nicole) via an interface, analyzed, and a value obtained as a particle size distribution is obtained. The primary particle size of the colorant was used.

Another feature of the present invention is the use of a metal salicylate compound as a specific colorant dispersant.

The colorant of the present invention is characterized in that its particle size can be easily controlled. However, from the viewpoints of compatibility of the toner binder resin and the release agent, and the toner chargeability, reaggregation and chargeability are considered. There is a tendency for defects to occur easily, and when toner is used, it is not always sufficient.

On the other hand, conventional techniques for improving dispersibility include a so-called flushing method described in, for example, JP-A-2-175770, and JP-A-5-247.
As disclosed in Japanese Patent Publication No. 370, there are disclosed many means such as a method of performing a surface treatment of a pigment, however, in view of versatility for controlling the toner charging property within an appropriate range and simplification of the process, etc. It was not enough.

Therefore, the present inventors have studied a substance which can control the chargeability together with the action of the dispersion improving additive suitable for the colorant of the present invention, and have reached the present invention.

The metal salicylate compound of the present invention includes
Complexes and / or complex salts containing aluminum, chromium, zinc, and iron as the central metal are preferable, and compounds containing aluminum as the central metal are most preferable from the chargeability adaptability to the colorant of the present invention.

As a means for adding and improving the metal salicylate compound to the pigment of the present invention, known means such as forming a master batch in advance can be used. In order to obtain the effect described above, it is preferable to add both at a ratio of 10 to 400 parts by weight, more preferably at a ratio of 10 to 100 parts by weight, based on 100 parts by weight of the pigment.

A further feature of the present invention is that a specific ester wax is added as a release agent having the function of the colorant dispersion aid of the present invention.

This occurs when the ester group in the wax has an affinity for the functional group of the pigment having the structure of the present invention, and the pigment is incorporated into the hydrophobic wax and buried in the toner. thinking.

Therefore, in the present invention, an improvement in chargeability is achieved by combining a wax having an ester group with the pigment of the present invention.

As a result of examination from that viewpoint,
The wax of the present invention more preferably has at least one long-chain ester moiety having 15 or more carbon atoms,
More preferably, it is 0 or less.

If the number of carbon atoms is less than 15, the surface of the pigment is modified, but the colorant is easily transferred to the surface of the fixing roller due to the heat of the fixing machine. This is likely to occur and lowers roller durability.

When the number of carbon atoms exceeds 30, the effect of plasticizing the wax on the resin becomes too large, and the fixability deteriorates. Also, the transparency is deteriorated.

In recent years, the necessity of a full-color double-sided image has been increasing, and when forming a double-sided image, the toner image on the transfer paper formed first on the front surface is also used for forming the image on the rear surface next. There is a possibility that the toner passes through the heating unit of the fixing device again, and it is necessary to sufficiently consider the high-temperature offset resistance of the toner. Therefore, in the present invention, it is necessary to add a large amount of ester wax.

For this reason, the ester wax of the present invention is required to impart releasability / transparency in addition to modifying the pigment, and it is preferable to add 5 to 30% by weight of the ester wax to the toner.

If the addition is less than 5% by weight, sufficient reforming property is not exhibited, and the image on the back side tends to show an offset phenomenon when a double-sided image is fixed.

If the content is more than 30% by weight, during the production of the toner, for example, device fusion or fusion of the toner is likely to occur in the production, and the impact resistance to the drum is reduced, so that filming occurs. It will be easier.

As a means for adding and modifying the ester wax to the pigment of the present invention, known means such as forming a master batch in advance can be used. In order to obtain the effect described above, it is preferable to add the ester wax at a ratio of 100 to 3000 parts by weight to 100 parts by weight of the metal salicylate and the pigment of the present invention at the time of addition.

In the present invention, as the ester wax to be used, a compound having a main peak maximum value of 40 to 90 ° C. measured according to ASTM D3418-8 is preferable. If the maximum peak is less than 40 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the hot offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of color mixing.

For measuring the temperature of the maximum peak value of the present invention,
For example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

The structural formulas of representative compounds of the specific ester waxes preferred for the present invention are shown below as general structural formulas (1) to (4).

[0059]

Embedded image (A and b each represent an integer of 0 to 4, and the sum of a and b is 4
Wherein R ₁ and R ₂ each represent an organic group having an integer of 1 to 40 carbon atoms, and the difference in the number of carbon atoms between R ₁ and R ₂ is 3 or more, and m and n are 0 to 25. And m and n do not become 0 at the same time. )

[0060]

Embedded image (A and b each represent an integer of 0 to 3, and the sum of a and b is 1
And R ₁ and R ₂ each represent an organic group having an integer of 1 to 40 carbon atoms, and the difference in carbon number between R ₁ and R ₂ is 3
R ₃ represents a hydrogen atom or an organic group having 1 or more carbon atoms. However, when the sum of a and b is 2, at least one of R ₃ represents an organic group having 1 or more carbon atoms. Indicates, k
Represents an integer of 1 to 3, m or n represents an integer of 0 to 25, and m and n are never 0 at the same time. )

[0061]

Embedded image (R ₁ and R ₃ represents an organic group having 6 to 32 carbon atoms, R ₁ and R ₃ may or may not be the same, R ₂
Represents an organic group having 1 to 20 carbon atoms. )

[0062]

Embedded image (R ₁ and R ₃ represents an organic group having 6 to 32 carbon atoms, R ₁ and R ₃ may or may not be the same, R _{2
Is, -CH 2 CH 2 OC 6 H} 4 OCH 2 CH 2 -, - (CH
_{(CH 3) CH 2 O)} m -C 6 H 4 C (CH 3) 2 C 6 H 4 -
(OCH ₂ CHCH _{3) m} - or those having a modified bisphenol skeleton, (CH _{2) n} - it indicates, m is an integer of 1 to 10, n is an integer of 1-20. )

[0063]

Embedded image (A represents an integer of 0 to 4, b represents an integer of 1 to 4, the sum of a and b is 4, and R ₁ has ₁ to 4 carbon atoms.
Represents an organic group having an integer of 0, wherein m and n are 0 to 25;
And m and n do not become 0 at the same time. )

In the present invention, the low-softening point substance contained in the toner preferably contains, as a main component, any of the above-mentioned substances. In the present invention, the main component refers to a gas chromatography method (GC
Method) means that the peak area of the substance of the present invention is 55% or more of the sum of the peak areas of all the low softening point substances.

The gas chromatography method (GC method)
It is measured using GC-17A (manufactured by Shimadzu Corporation). A sample was prepared by dissolving 1 μm
is injected into a GC device equipped with an on-column injector. The column was a 0.5 mm diameter x 10 m length Ultra
Use Alloy-1 (HT). Column first 40
° C to 40 ° C / min. At a heating rate of 200 ° C., and further at 15 ° C./min. At 350 ° C. and then at 7 ° C./min. The temperature is increased up to 450 ° C. at the temperature increasing speed. As the carrier gas, He gas flows under a pressure condition of 50 kPa. Then, the content of the substance to be obtained is calculated from the obtained peak area ratio.

The ester wax preferably used in the present invention preferably has a hardness of 0.5 to 5.0.
The hardness of the ester wax is 20 mm in diameter and 5 mm in thickness. After preparing a cylindrical sample, for example, a dynamic ultra-micro hardness tester (DUH-200) manufactured by Shimadzu Corporation
Is a value obtained by measuring Vickers hardness using the above formula. The measurement conditions are as follows. After displacing 10 μm under a load speed of 9.67 mm / sec with a load of 0.5 g and holding it for 15 seconds, the resulting dent shape is measured to determine the Vickers hardness. 0.5 hardness
If the ester wax is less than the above, the pressure dependency and the process speed dependence of the fixing device become large, and the development of the high-temperature offset resistance tends to be insufficient, while if it exceeds 5.0, the storage stability of the toner is poor, and the ester wax is poor. Since the self-cohesive force of itself is small, the high-temperature offset resistance tends to be insufficient. Specific compounds include the following compounds.

[0067]

Embedded image

[0068]

Embedded image

[0069]

Embedded image

[0070]

Embedded image

In the present invention, since the above-mentioned wax causes aggregation inhibition and also exerts a releasing effect, the wax is contained in the toner in an amount of 5 to 2%.
It is preferable to contain 5 wt%. When the content of the wax is less than 5% by weight, the effect of the present invention is not sufficiently exhibited, and the coloring power is slightly reduced. On the other hand, if the content of the wax exceeds 25% by weight, the aggregation of the pigment starts to be inhibited, and the phenomenon that the pigment jumps out of the toner occurs.

A further feature of the present invention is to obtain a toner by directly polymerizing a polymerizable monomer in a medium.

The polymerization method is described, for example, in JP-B-36-10231.
JP, JP-B-43-10799 and JP-B-51
As proposed in JP-A-14895, etc., in the polymerization method, a polymerizable monomer, a colorant, a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent and other additives are uniformly dissolved or dissolved. After being dispersed into a monomer composition, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and simultaneously subjected to a polymerization reaction. This is a method for obtaining a developer having a desired particle size.

When the polymer is directly polymerized in an aqueous medium, the colorant and the charge control agent are uniformly dissolved in the monomer to form a toner. Therefore, the exposure of the colorant to the surface is suppressed. It shows a uniform charging behavior.

In addition, when the colorant of the present invention and the metal salicylate compound are dispersed in the polymerizable monomer, the dispersion in the monomer is particularly stable as compared with the other yellow colorants. The amount of the coloring agent required to obtain the coloring power of the toner may be small, and as a result, a toner having excellent transparency and sharp charge can be obtained.

In the pulverization method, as the particle size measured by a Coulter counter becomes 9 μm or less,
There is a tendency that it is extremely difficult to classify the developer into uniform dispersion and highly pulverizable properties of the raw materials used, which has not been a problem in the past, and further to a sharp particle size distribution, but the coloring agent of the present invention and metal salicylate When the compound is used in the polymerization method, it has excellent properties in that respect, and furthermore, it can use a large amount of a low softening point substance that could not be used in the conventional pulverization method, and the selection range of the material. This is also preferable because it has features such as the spread of

When the pigment of the present invention is added by a polymerization method, the compound (I) of the present invention is dispersed in the monomer in advance in order to facilitate crushing in the polymerizable monomer. It is preferable that the particle size of the previous pigment falls within the range of the present invention, which is close to the dispersed particle size in the toner. Specifically, the particle size distribution of the compound (I) in the alcoholic organic solvent is set to the number average particle size. It is preferably 0.01 to 0.50 μm, more preferably 0.01 to 0.30 μm.

The particle size distribution in the alcoholic organic solvent in the present invention was specifically measured by the following method.

As a measuring device, Coulter Counter L
Using an S type (manufactured by Coulter), a pigment-added solution was prepared in ethanol so as to have a concentration of about 20 to 400 ppm, and the solution was treated with an ultrasonic cleaner (VS-150 manufactured by Iachi).
The number distribution value obtained by measuring after 0 second dispersion was calculated. Then, the number-based length average particle diameter (D1) determined from the number distribution according to the present invention was determined.

In the method for directly obtaining a toner by a polymerization method, a known monomer is preferably used. Specifically, styrene, o (m-, p-)-methylstyrene, m (p
-)-Styrene monomers such as ethylstyrene; (meth)
Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate,
Octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth) acryl (Meth) acrylate monomers such as diethylaminoethyl acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. These may be used alone or generally in the published Polymer Handbook, 2nd Edition, III-P 139-192 (John Wire
y & Sons) theoretical glass temperature (Tg)
However, monomers are appropriately mixed and used so as to show a temperature of 40 to 85 ° C. If the theoretical glass transition temperature is less than 40 ° C,
Problems arise in terms of the storage stability of the toner and the durability stability of the toner. On the other hand, when the temperature exceeds 85 ° C., the fixation point is increased. Poor, moreover OHP
The transparency of the image is remarkably reduced, which is not preferable from the viewpoint of high image quality.

When the pulverization method of the present invention is used, as the binder resin, a styrene-acrylic resin, a maleic acid copolymer, a polyester resin,
A known material such as an epoxy resin can be used, but in the case of the pulverization method, it is preferable to use a polyester resin in order to maintain dispersibility with the present invention and chargeability.

The molecular weight of the polymerized resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, the toner is extracted in advance with a toluene solvent using a Soxhlet extractor for 20 hours, and then toluene is distilled off using a rotary evaporator. Further, the substance having a low softening point is dissolved, but the resin is dissolved. An organic solvent that cannot be obtained, for example, chloroform, was added thereto, and the solution was sufficiently washed. A solution obtained by filtering a solution dissolved in THF (tetrahydrofuran) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm was used to obtain a sample using Waters 150C. The column configuration is A-801, 802, 80 manufactured by Showa Denko
3, 804, 805, 806, 807 can be linked and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve.
The number average molecular weight (Mn) of the obtained resin component is 5000
１，1,000,000, weight average molecular weight (Mw)
And the number average molecular weight (Mn) ratio (Mw / Mn) is 2 to 1
Resins showing 00 are preferred for the present invention.

In the present invention, a polar resin may be further added in addition to the monomer component in order to incorporate a low softening point substance into the resin. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used.

In the present invention, a material having a low softening point may be added to the resin in order to impart a releasing effect.

As the low softening point substance used in the present invention, a compound having a main peak maximum value of 50 to 180 ° C. measured according to ASTM D3418-8 is preferable. If the maximum peak value is less than 50 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high-temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, if the maximum peak value exceeds 180 ° C., the crystallinity and dispersibility of the softening point substance are deteriorated at present, which is not preferable in terms of fixability and transparency.

For measuring the temperature of the maximum peak value of the present invention,
For example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./min. Perform the measurement with.

Specifically, paraffin wax, polyolefin wax, Fischer-Tropsch wax,
Amide waxes, ester waxes, higher fatty acids and their graft / block compounds can be used.

In addition to the metal salicylate compound of the present invention, a charge control agent may be further added to the present invention. As the charge control agent, a known charge control agent can be used, but a charge control agent which is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Further, when a direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous system is particularly preferable. Specific examples of the negative compound include a metal compound of naphthoic acid and dicarboxylic acid, a sulfonic acid, a high molecular compound having a carboxylic acid as a side chain, a boron compound, a urea compound, a silicon compound, and a carricks arene. A quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, or the like is preferably used as a positive compound. The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin. However, in the present invention, the addition of the charge control agent is not essential because the metal salicylate compound has already been added,
When using the two-component developing method, use the frictional charging with the carrier, and when using the non-magnetic one-component blade coating developing method, positively use the frictional charging with the blade member or the sleeve member. Therefore, it is not always necessary to include a charge control agent in the toner.

When the direct polymerization method is used in the present invention,
As the polymerization initiator, for example, 2,2′-azobis- (2,
4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-
Azo or diazo polymerization initiators such as methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl A peroxide-based polymerization initiator such as peroxide is used. The amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5 to 20% by weight based on the monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but may be used alone or in combination with reference to the 10-hour half-life temperature.

In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.

As the dispersant used in the toner production method of the present invention, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide,
Examples include magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, a magnetic material, and ferrite. As an organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like can be used by dispersing them in an aqueous phase. It is preferable to use 0.2 to 2.0 parts by weight of these dispersants based on 100 parts by weight of the polymerizable monomer.

As these dispersants, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound may be formed under high-speed stirring in a dispersion medium. it can. For example, in the case of tricalcium phosphate, a dispersant suitable for suspension polymerization can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.

In order to make these dispersants finer, the content of 0.1.
001 to 0.1 parts by weight of a surfactant may be used in combination.
Specifically, commercially available nonionic, anionic, and cationic surfactants can be used, and examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, and potassium stearate. , Calcium oleate and the like.

When a direct polymerization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method.

That is, a releasing agent comprising a low softening point substance, a coloring agent, a metal salicylate compound, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and a homogenizer, an ultrasonic disperser, etc. The monomer system uniformly dissolved or dispersed by the above method is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the agitation speed and time are adjusted so that the monomer droplets have the desired developer particle size, and granulation is performed. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization temperature is 40 ° C. or higher, generally 50 to 90 ° C.
It is preferable to carry out the polymerization at a temperature set as described above. Further, the temperature may be raised in the latter half of the polymerization reaction, and further, the second half of the reaction or After completion, the aqueous medium may be partially distilled off. After completion of the reaction, the generated developer particles are collected by washing and filtration, and dried. In the suspension polymerization method, usually, 300 to 30 parts of water is added to 100 parts by weight of the monomer system.
It is preferable to use 00 parts by weight as a dispersion medium.

When the pulverization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method.

A part of the binder resin, the coloring agent of the present invention and the metal salicylate compound of the present invention are previously kneaded with a three-roll mill or the like to obtain a master batch. Then, a predetermined binder resin, a release agent, and other additives are added to the master batch, and the mixture is diluted and kneaded, and after pulverization and classification steps are performed, desired toner particles are obtained.

Next, each measuring method used in the present invention will be described.

(1) Measurement of Particle Size Distribution The particle size distribution can be measured by various methods. In the present invention, the measurement was carried out using a Coulter counter.

That is, as the measuring device, Coulter Counter TA-II or Coulter Multisizer II
(Manufactured by Coulter). As the electrolyte, about 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter Inc.) can be used.

The measuring method is as follows.
0.1 to 5 ml of a surfactant, preferably an alkylbenzenesulfonate, is added as a dispersant in ~ 150 ml;
Further, 2 to 20 mg of a measurement sample is added.

The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of the toner were measured using the measuring device with a 100 μm aperture as the aperture. The distribution and number distribution were calculated.

Then, it was determined from the volume distribution according to the present invention.
Weight-average particle size (D 4) (Representative of each channel
Value as a representative value for each channel), and the coefficient of variation
I did.

(2) Color Evaluation Method for Low Gloss Image To 7 parts by weight of toner, 93 parts by weight of an acrylic resin-coated ferrite carrier are mixed to prepare a developer.

Using the obtained developer, the latent image was transferred by a modified full color copier CLC500 made by Canon, which was modified so that the fixing temperature was variable, the upper and lower rollers were made of fluorine, and the fixing oil application mechanism was omitted. The image was transferred onto a material to obtain an image.

At this time, the fixing condition is that the transfer material has a gloss of 4
Weighing 99 g / m ² paper, the amount of toner
A solid monochrome image of 0.7 mg / cm ² was obtained, and the fixing temperature of the image was adjusted so as to have a gloss of 10 to 15.

The density condition of each color is adjusted so that a gray scale and a color patch manufactured by Kodak Co., Ltd. are used as a document and the gray scale can be reproduced as faithfully as possible in a full-color copy image. The concentration was adjusted so as to be 1.1 or more.

Then, using a modified full-color copying machine CLC500 made by Canon in the above state, green (G), which is a superimposed image of yellow (Y) and cyan (C), is output under a fixing condition of glossiness 15 to 20. The overlapping portion of each color at the highest density was evaluated based on the difference in color tone from a color patch manufactured by Kodak Corporation.

The evaluation was performed in five stages. The chromaticity difference formula of CMC (1: 1) was introduced for the lightness L ^* , chroma C ^* , and hue angle h ^* of the image. When

[0110]

ΔE> 110 = × 100 <ΔE ≦ 110 = △ × 90 <ΔE ≦ 100 = △ 70 <ΔE ≦ 90 = △ ΔE ≦ 70 = ○ (ΔE: chromaticity difference).

The formula of CMC is Journal of
he Society of Dyers and C
ollists, 100 128 (1984). The chromaticity equation is evaluated by adding a correction of visual sensation to lightness L ^* , chroma C ^* , and hue angle h ^* , and is expressed by the following equation. ΔE = [(ΔL ^* / ISL) ² + (ΔC ^* / cS
c) ² + (ΔH ^* / SH) ² ] ^1/2 (ISL: correction coefficient for lightness ΔL ^* , cSc: correction coefficient for saturation ΔC ^* , SH: correction coefficient for hue angle ΔH ^* )

Further, a value obtained by subtracting the reflectance at the time of measuring the white paper from the reflectance of the non-image portion was evaluated as a fog reflectance and evaluated as a fog density. Here, TC-6DS (manufactured by Tokyo Denshoku) was used for measuring the reflectance.

(3) Transparency Transmission Image Evaluation Method The transmittance of a transparency image is evaluated as follows.

A commercially available full-color copying machine (CLC500;
Using a remodeling machine, developed and transferred on a transparency sheet (CG3300: 3M) at a development contrast of 320 V under an environment of a temperature of 23 ° C./65% RH and an unfixed image having a gradation. A toner image was obtained.
The obtained product was fixed to an external fixing device in which the surface of the fixing roller was a fluororesin (no oil application function; roller diameter 40
φ), fixing temperature 180 degrees, process speed 30m
At m / sec, a fixed image was obtained.

The image density of the obtained fixed image is 0.4 to 0.1.
The transmittance at 6 locations was measured.

The transmittance was measured using a Shimadzu self-spectrophotometer UV.
2200 (manufactured by Shimadzu Corporation) was used for the measurement. Then, the transmittance of the transparency sheet alone is set to 100
%, And the transmittance at the maximum absorption wavelength at 600 nm was measured.

The evaluation was made based on the following criteria. ：: transmittance is 80% or more △: transmittance is 65% or more and less than 80% △: transmittance is 50% or more and less than 65% ×: transmittance is less than 50%

As for the color space measurement of the transmitted light, the obtained image is transferred to an overhead projector (OHP:
3550, a transmission image, and projecting the image projected on a white wall surface using a spectral radiance meter (P
R650).

Then, the hue angle h ^* (OHP) of the image projected on the white wall surface and the hue angle h ^* of the solid portion on the previous paper ^.
The angle difference Δh ^* from the (paper) is defined as
The results are shown on a scale.

[0120]

Δh ^* > 30 = × 20 <Δh ^* ≦ 30 = △ × 10 <Δh ^* ≦ 20 = △ 5 <Δh ^* ≦ 10 = △ Δh ^* ≦ 5 = ○ (Δh ^* : chromaticity difference) Was evaluated.

[0121]

The present invention will be specifically described below based on examples. The parts in the following formulations are parts by weight unless otherwise specified.

<Example 1> 0.1 M Na_ThreePO_FourAqueous solution
And 1M Ca Cl_TwoPrepare an aqueous solution. High-speed stirrer T
Two-liter four-necked flask equipped with K-type homomixer
Inside, 710 parts of ion-exchanged water and 0.1 M-Na_ThreePO_Fourwater
550 parts of the solution was added, and the number of revolutions was adjusted to 10,000 rpm.
And warmed to 65 ° C. Here, 1M Ca Cl_Two
68 parts of an aqueous solution is gradually added, and a minute poorly water-soluble dispersant C
a_Three(PO_Four)_TwoWas prepared.

On the other hand, the dispersoid system is composed of 160 parts of styrene monomer, 40 parts of n-butyl acrylate monomer, 5 parts of coloring agent [compound (I); average particle size of 0.06 μm], 10 parts of saturated polyester and 10 parts of terephthalic acid- Propylene oxide-modified bisphenol A Acid value 8, peak molecular weight: 7000) Aluminum salicylate compound 3 parts Ester wax [Compound (4); maximum peak value 64.4 ° C] 20 parts The above mixture was dispersed using an attritor for 3 hours. Then, 2,2'-azobis (2,4'-
Dimethyl valeronitrile) was added, and the dispersion was charged into a dispersion medium and granulated for 8 minutes while maintaining the rotation speed. Then change the stirrer from a high-speed stirrer to a propeller stirring blade and
4 hours at 60 ° C while stirring by rotation, then 80 ° C
And polymerization was continued for 4 hours for a total of 8 hours. After the polymerization was completed, the slurry was cooled, and diluted hydrochloric acid was added to remove the dispersant.

By further washing and drying, the weight average diameter of the yellow toner measured by a Coulter counter was 6.6 μm, and the number variation coefficient was 24%.

[0125] Hydrophobized titanium oxide was externally added to the obtained toner by 2% to obtain a toner having excellent fluidity.
Then, 93 parts of a ferrite carrier coated with an acrylic resin were mixed with each other to obtain a developer, and a glossy 15 image and a transparency image were obtained with a modified full-color copying machine CLC500 manufactured by Canon Inc., and the evaluation was performed.

Then, there is almost no change in the hue angle between the image on paper and the transparency transmission image, and the OHP
It was also excellent in transparency.

The pigment is C.I. I. Pig. B15: 3
A cyan toner was produced in the same manner except that the amount was changed to 6 parts, and the reproducibility of green as a secondary color was confirmed together with the yellow toner. As a result, a clear green image was obtained.

<Comparative Example 1> In the formulation of Example 1, the coloring agent was changed from compound (I) to C.I. I. Pig. A yellow toner was manufactured in the same manner as in Example 1 except that the amount was changed to Y837 part.

Example 2 A yellow toner was manufactured in the same manner as in Example 1 except that the amount of the aluminum salicylate compound was changed from 3 parts to 0.2 part in the formulation of Example 1. .

Example 3 Polyester resin (Mn = 2500, Mw = 21000, Tg) obtained by condensing propoxylated bisphenol with fumaric acid and trimellitic acid
= 59 ° C, acid value = 9) 100 parts of compound (I), 2 parts of aluminum salicylate compound, 2 parts of ester wax (maximum peak value: 69.4 ° C) and 2 parts were melted, kneaded, crushed and classified. Yellow particles were obtained. The weight average diameter of the yellow particles was 6.7 μm, and the number variation coefficient was 38%.

Example 4 A yellow toner was prepared in the same manner as in Example 1 except that the colorant was changed to the compound (I) having a particle diameter of 0.60 μm in the formulation of Example 1. Was manufactured.

<Example 5> A yellow toner was produced in the same manner as in Example 1 except that the aluminum salicylate compound was changed to the zinc salicylate compound in the formulation of Example 1.

The characteristics of each toner and the evaluation thereof are shown below.

[0134]

[Table 1]

[0135]

According to the present invention, a clear color can be obtained on an image having a low gloss level, and an image having a well-balanced hue and excellent transparency transmittance can be obtained.

Claims (8)

[Claims] 1. A yellow toner comprising at least a binder resin, a yellow colorant represented by the following structural formula, and a metal salicylate compound. Embedded image 2. The yellow toner according to claim 1, wherein the salicylic acid metal compound is contained in an amount of 10 to 400 parts by weight based on 100 parts by weight of the yellow colorant. 3. The colorant having a number average diameter of 0.01 to 0.1.
The yellow toner according to claim 1, wherein the thickness of the yellow toner is 70 μm. 4. The yellow toner according to claim 1, wherein the salicylic acid metal compound is an aluminum compound. 5. The toner according to claim 1, wherein the toner contains a low softening point substance having at least one long-chain ester moiety having 15 or more carbon atoms. Yellow toner. 6. The yellow toner according to claim 1, wherein the low softening point substance mainly comprises a substance represented by any one of the following structural formulas. Embedded image (A and b each represent an integer of 0 to 4, and the sum of a and b is 4
R ₁ and R ₂ each represent an organic group having an integer of 1 to 40 carbon atoms, and the difference in the number of carbon atoms between R ₁ and R ₂ is 3 or more, and m and n are 0 to 25. And m and n are simultaneously 0
Never be. ) (A and b each represent an integer of 0 to 3, and the sum of a and b is 1
R ₁ and R ₂ each represent an organic group having an integer of 1 to 40 carbon atoms, and the difference in the number of carbon atoms between R ₁ and R ₂ is 3 or more; and R ₃ is a hydrogen atom Or an organic group having 1 or more carbon atoms,
However, when the sum of a and b is 2, at least one of R ₃ represents an organic group having 1 or more carbon atoms, k represents an integer of 1 to 3, and m or n represents 0 to 25. Represents an integer, and m and n are simultaneously 0
Never be. ) (R ₁ and R ₃ represent an organic group having 6 to 32 carbon atoms, R ₁ and R ₃ may or may not be the same, and R ₂ is an organic group having 1 to 20 carbon atoms. Is shown.) (R ₁ and R ₃ represent an organic group having 6 to 32 carbon atoms, R ₁ and R ₃ may or may not be the same, and R ₂ is —CH ₂ CH ₂ OC ₆ H ₄ OCH ₂ CH ₂ -,-(C
_{H (CH 3) CH 2 O} ) m -C 6 H 4 C (CH 3) 2 C 6 H 4 -
(OCH ₂ CHCH _{3) m} - or those having a modified bisphenol skeleton, - (CH _{2) n} - indicates, m is 1 to 10
And n represents an integer of 1 to 20. ) (A represents an integer of 0 to 4, b represents an integer of 1 to 4, the sum of a and b is 4, R ₁ represents an organic group having an integer of 1 to 40 carbon atoms. And m and n represent an integer of 0 to 25, and m and n are 0 at the same time.
Never be. ) 7. The toner according to claim 1, wherein the toner is obtained by directly polymerizing a polymerizable monomer containing at least the colorant and obtaining the toner particles. Yellow toner. 8. A method for producing a yellow toner obtained by directly polymerizing a polymerizable monomer system containing at least a yellow colorant as toner particles, wherein the particle size distribution in an alcohol-based organic solvent is 0 in terms of number average diameter. A method for producing a yellow toner, comprising: adding a colorant having a thickness of 0.01 to 0.50 μm in a polymerizable monomer and then polymerizing the colorant.