JPH11194535A - Preparation of colored polymerization toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide a polymerization toner which is colored with high density, and which has a small particle size and sharp particle size distribution. SOLUTION: In this preparation, a monomer composition containing a poliymerizable monomer and a dispersion stabilizer is added into a reaction medium comprising mainly an organic solvent, the polymerizable monomer is dissolved in the medium to polymerize the monomer, a resulting polymer synthesized by polymerization of the monomer is precipitated in the medium, and the polymer is colored with a coloring agent. An organic solvent-soluble stabilizer is used for the dispersion stabilizer, and a water-insoluble oil-soluble dye is used as the coloring agent. After the reaction medium with the polymer precipitated is heated and the coloring agent is added to be dissolved into the medium, coloring of a toner particle is carried out by adding gently water to the medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a colored polymerization toner used in electrophotography.

[0002]

2. Description of the Related Art In order to make an electric or magnetic latent image visible on a recording medium, an electro-sensitive or magnetically sensitive fine particle such as toner is attracted to the latent image to form a visible image. There is a forming method. A representative example thereof is electrophotography, and many methods are known, for example, as described in US Pat. No. 2,297,691.
In this electrophotography, generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed with toner to form a toner. After forming an image and transferring the toner image to a transfer material such as paper as necessary, the toner image is fixed to the transfer material using heat, pressure, or solvent vapor to obtain a copy.

[0003] In recent years, the electrophotographic technology as described above has
Because of its high printing quality and quietness of the apparatus during operation, it is widely used in output means such as computers and word processors, so-called printers. In order to improve the printing quality of these printers, the technology to reduce the particle size of the toner used as the developer of the electrostatic latent image and reproduce the electrostatic latent image finely and faithfully is being actively studied. Have been. Normally, toners used in printers and / or copiers are mainly composed of a binder resin, a colorant such as a pigment and a dye such as carbon black, and a magnetic substance and waxes added as needed. And the like, usually having a particle size of 6 to 30 μm.
Within the range. In general, toner production methods include:
A colorant comprising a dye or pigment or a magnetic material is mixed and melted in a thermoplastic resin as a binder resin, and a melt in which the colorant is uniformly dispersed in the resin is cooled and solidified. Is finely pulverized and further classified to obtain a toner product having a desired particle size.

The above-described method of producing a toner by a so-called pulverization method is relatively stable as a technology, and has an advantage that each material and each process can be managed relatively easily. Since the particle size of the toner depends on the mechanical pulverization of the resin, for example, the particle size of the toner
Attempts to reduce the particle size to μm or less, for example, will reduce the product yield as described below. First, in order to form a fine and high-density image in electrophotography, it is required that the toner be charged with a high charge amount and uniformly. Here, the toner has a property that, when the toner is charged by the frictional charging member, the smaller the particle size of the toner, the higher the charge amount. Therefore, in order to accurately and faithfully reproduce the electrostatic latent image, it is necessary to reduce the particle size of the toner used for image formation and to sharpen the particle size distribution. To do this,
In the classifying step, it is necessary to remove a large amount of fine powder and coarse powder, so that the product yield is reduced.

In recent years, a method for producing a toner by a so-called polymerization method, mainly a method for producing a toner by a suspension polymerization method, has been proposed as an improvement over the above-mentioned drawbacks in the method for producing a toner by the pulverization method. The method is described in, for example, JP-B-36-10231 and JP-B-51-14.
895, JP-A-53-177735, JP-A-53-17736, and JP-A-53-1773.
No. 7 is described. These methods usually involve
First, a coloring agent composed of a binder resin, a dye or a pigment such as carbon black, and, if necessary, further included in a toner such as a magnetic substance, a charge control agent, a release agent such as wax or silicone oil, etc. The substance to be dissolved is appropriately dissolved or dispersed in a polymerizable monomer together with a polymerization initiator and a dispersant to prepare a polymerizable composition, and then the composition is dispersed in an aqueous continuous phase containing a dispersion stabilizer. To obtain a dispersion of fine particles. Thereafter, the dispersion is polymerized and solidified to obtain toner particles having a desired particle size and composition. Since this method has no grinding step,
Effects such as energy saving, improvement in process yield, and cost reduction by half are expected, but the particle size distribution of the product varies depending on the manufacturing conditions such as stirring state and manufacturing scale.
In many cases, a toner having a relatively wide particle size distribution can be obtained. Therefore, in the case of the above suspension polymerization method, after obtaining the toner particles, the toner particles are further classified to adjust the particle size to a desired particle size distribution required for obtaining a high-quality, high-definition copy image. Processing is often performed.

Further, as a method for producing a polymerization toner having a sharp particle size distribution, for example, Japanese Patent Publication No.
No. 3, JP-A-61-18965, JP-A-61-18965
There is a method using a so-called dispersion polymerization method proposed in JP-A-18966 and JP-A-61-228458. In this method, in a non-aqueous solvent, a polymer stabilizer and a polymerizable monomer, and an initiator, and if necessary, a colorant, a uniform system in which a charge control agent, etc. are dissolved, are prepared. Heating or irradiating light, etc., initiates the polymerization reaction to generate particles that become the core of the particles, and the particles grow to produce toner particles having a uniform particle size distribution.

[0007] The above-mentioned method for producing a toner by the dispersion polymerization method is regarded as an effective method for producing monodisperse particles having a particle size of about 1 to 10 µm. Further, since the particle size distribution of the toner obtained by the method is very sharp, the charge amount distribution when the toner is charged is also sharp. Therefore, when an image is formed using these toners, the dot reproducibility in development, the fidelity of transfer of the toner image, and the fixability of the transferred toner image are improved by the toner obtained by another method. It is better than when used. However, this method has a problem in that when a charge control agent, a coloring agent, and the like are internally added to the resin particles, the range of selection of materials is narrow. For example, it is necessary to select a charge control agent or a colorant that does not function as a polymerization inhibitor, or to incorporate the resin material into the resin particles in a favorable state in order to add the solubility of the material used in the reaction medium. And the particle size must be carefully considered.
Further, for example, when a colorant such as a pigment is used as a material for forming the toner, it is necessary to perform an operation such as performing a surface treatment on the pigment particles, and if this is not appropriate, uniform particles can be successfully formed. In many cases, the particle size distribution becomes bloat without being used.

As a means for solving the above-mentioned problem when the colorant is added, a colorant such as a pigment is not added internally to the resin particles. A coloring method has been proposed. For example, JP-A-61-18965 describes a method in which a coating layer such as a coloring agent is provided on the surface of polymer particles by a jet mill.
JP-A-3166 and JP-A-63-244057 propose a method of embedding a pigment in a resin surface by mechanical strain. However, these methods have a problem that a sufficient coloring power cannot be obtained as compared with the case where the colorant is internally added to the resin particles.

Japanese Patent Publication No. 7-52307 proposes a method for obtaining a colored toner by heating and stirring resin particles with a dye or the like in an aqueous solvent. But,
In particular, when the above method is applied to the monodisperse particles obtained by the dispersion polymerization method and the toner particles are colored, once the polymer particles are solid-liquid separated and washed from the non-aqueous solvent, and then the aqueous particles are washed. It is necessary to redisperse in a solvent, and there is a problem that the number of steps increases.

Further, JP-A-50-46333, JP-A-61-228458, and JP-A-63-1066.
No. 67, and Japanese Patent Laid-Open No. 1-103631,
A method has been proposed in which resin particles are impregnated in a dye solution and dyed. According to this method, since the dye penetrates into the resin, it is possible to uniformly dye the resin particles, but not all the dye in the dye solution is selectively dyed on the resin. Since the dyeing is carried out according to the partition coefficient between the solvent and the resin, it is necessary to select an appropriate combination of dyes for efficient dyeing. In contrast,
Choosing the right dye combination for each color is very difficult.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polymerized toner which can easily obtain a highly concentrated toner having a small particle size and a sharp particle size distribution. An object of the present invention is to provide a method for producing a toner.

[0012]

The above objects are achieved by the present invention described below. That is, the present invention, a monomer composition containing at least a polymerizable monomer and a dispersion stabilizer is added to a reaction medium mainly composed of an organic solvent, at least the polymerizable monomer in the reaction medium Is polymerized in a dissolved state, and a polymer synthesized by polymerization of the polymerizable monomer is precipitated in the reaction medium, and then the polymer is colored with a colorant to form a toner. In the method for producing a colored polymerization toner for producing particles, (1) a dispersion stabilizer which is soluble in the organic solvent is used;
As the colorant, using an oil-soluble dye insoluble in water,
(3) After heating the reaction medium in which the polymer is precipitated, adding the colorant to the reaction medium and dissolving the colorant in the reaction medium, gently add water to the reaction medium. A method for producing a colored polymerization toner, characterized in that toner particles are colored by adding the toner.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to preferred embodiments of a method for producing a colored polymerization toner of the present invention. The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, in the above-described method for producing a polymerized toner using the dispersion polymerization method, first of all, as a dispersion stabilizer, Second, a water-insoluble oil-soluble dye is used as a coloring agent for coloring the polymerized toner particles, which is soluble in an organic solvent used as a main component and also soluble in water. Further, by adding a colorant to the reaction medium to dissolve the dye, and then slowly adding water, the dye can be selectively dyed on the resin particles, and the dye can be dyed at a high concentration. The inventors have found that a toner having a sharp particle size distribution with a small particle size can be obtained. According to the present invention, as in the case of using the conventional dispersion polymerization method, the polymer particles are subjected to solid-liquid separation from the non-aqueous reaction medium, followed by re-dispersion in an aqueous solvent and then performing a coloring treatment. The above-described excellent effects can be obtained by a simple method without requiring any special steps. In the present invention, “soluble” is defined as the complete dissolution of the dispersion stabilizer in the organic solvent used in the present invention and a mixed solvent of the organic solvent and water in a ratio of 1: 2. In the present invention, “insoluble” is defined as a dye having a solubility in water of 0.1% or less.

In the method for producing a colored polymerization toner according to the present invention, a dispersion stabilizer and a polymerizable polymer are first added to a reaction medium mainly composed of an organic solvent in the same manner as in a conventionally known method for producing a polymerized toner. A homogeneous system in which a monomer, a polymerization initiator, and, if necessary, a charge control agent and the like are dissolved is prepared, and a polymerization reaction of the polymerizable monomer is performed by heating or irradiating the homogeneous system with a particle size. Polymerized toner particles having a small particle size and uniform distribution are produced. At this time, the particle size of the produced particles depends on the dispersion stabilizer used, the reaction medium (particularly, the type and amount of the organic solvent used), the amount ratio of the polymerizable monomer, the polymerization initiator, and other additives. And the particle size distribution can be controlled to an optimum one. Hereinafter, each material used for producing the polymerized toner particles will be described.

First, the reaction medium used in the method for producing the polymerization toner of the present invention is mainly composed of an organic solvent, and the organic solvent used at that time has a solubility in the polymerizable monomer used. In consideration of the solubility of the polymerizable monomer with a polymer obtained by polymerization, and the miscibility with water, a configuration in which polymerization in an optimal state is performed may be determined.
Specific examples of the organic solvent that can be used in the present invention include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and tert-butyl alcohol; ether alcohols such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; And ketones such as methyl ethyl ketone; ethers such as triethylene glycol; and acids such as formic acid, acetic acid and propionic acid. In the present invention, a non-aqueous reaction medium obtained by mixing two or more of these organic solvents may be used, or an aqueous reaction medium obtained by mixing these organic solvents with water. A medium may be used. When constituting the reaction medium, the concentration of the polymerizable monomer with respect to these organic solvents may be 1% by weight to 80% by weight, preferably 10% by weight to 65% by weight.

In the method for producing a polymerization toner according to the present invention, the polymerizable monomer and the polymer obtained from the monomer are uniformly dispersed in the reaction medium having the above-described structure. Although a dispersion stabilizer is required, as the dispersion stabilizer,
Use those that are soluble in the organic solvent that is the main component of the reaction medium and also soluble in water. That is, in this way, a good dispersion state can be maintained both in the polymerization process and in the dyeing process. Examples of those soluble in an organic solvent and also soluble in water include the following polymer dispersion stabilizers. Specific examples of the polymer dispersion stabilizer include, for example, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyvinyl sulfonic acid, polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone, polyvinyl acetate, cellulose acetate, polyvinyl propionate, polyvinyl butyrate Rate, hydroxyethyl cellulose, cellulose nitrate and the like. Further, in the present invention, two or more kinds of polymer dispersion stabilizers selected from these may be mixed and used at the same time, or a copolymer obtained by copolymerizing these polymer dispersion stabilizers may be used. . The concentration of the dispersion stabilizer used in the present invention is 0.1 to 50% by weight based on the organic solvent.
It is preferable that More preferably, the content may be 0.1 to 30% by weight.

As the polymerizable monomer used in the method for producing the polymerization toner of the present invention, any of an addition polymerization type monomer and a condensation polymerization type monomer can be used. In the present invention, an addition polymerization monomer is particularly preferably used. Specific examples of such a material include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, and p-methylstyrene.
-Chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn
-Hexylstyrene, pn-octylstyrene, p-
n-nonylstyrene, pn-decylstyrene, pn
Styrene such as dodecyl styrene and derivatives thereof; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl iodide and the like Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate, ethyl methacrylate, piperyl methacrylate, n-methacrylic acid
Octyl, dodecyl methacrylate, methacrylic acid-2-
Α-methylene fatty acid monocarboxylic esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate and phenyl acrylate; vinyl methyl ether, vinyl Vinyl ethers such as ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole and N-vinyl carb Tetrazole, N- vinyl indole,
N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; acrylonitrile, methacrylonitrile,
An acrylic acid or methacrylic acid derivative such as acrylamide can be used.

In the method for producing a polymerization toner according to the present invention, toner particles are produced by polymerizing the polymerizable monomer as described above in a reaction medium. The initiator can be used to control the reaction to an optimal state. Specific examples of the polymerization initiator that can be used in the present invention include 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvaleronitrile), and 2,2-azobis (2 -Methylbutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), dimethyl-2,2-azobisisobutyrate, 4,4-azobis-4-cyanovaleric acid, 2,2-
Azo compounds such as azobis (4-methoxy-2,4-dimethylvaleronitrile), benzoyl peroxide,
Examples include peroxides such as methyl ethyl ketone peroxide, alkali metals, metal hydroxides, nucleophilic reagents such as Grignard reagents, protonic acids, metal halides, and stable carbonium ions. The use concentration of these polymerization initiators is preferably about 0.1 to 20% by weight, more preferably 0.1 to 10% by weight, based on the polymerizable monomer.
% By weight. In the method for producing the polymerization toner of the present invention, a conventionally known chain transfer agent is used in order to appropriately control the polymerization reaction and to optimize the particle size and particle size distribution of the resin particles to be produced. May be.

In the method for producing a polymerization toner of the present invention, dispersion polymerization is carried out using a monomer composition comprising the above-described forming material to produce resin particles (polymer particles). The resin particles are heated and colored with a coloring agent to obtain colored toner particles. At this time, without solid-liquid separation of the resin particles after the polymerization reaction, a water-insoluble colorant is added to the reaction medium in a state where the polymer is precipitated, and then the water particles are slowly added to color the toner particles. Do.
As the coloring agent, an oil-soluble dye insoluble in water is used. That is, in the present invention, high density coloring is performed on toner particles by the following mechanism. First, the dye is once uniformly dissolved by adding the dye to a reaction medium mainly containing an organic solvent. Thereafter, the water-insoluble dye is slowly precipitated by slowly adding water to the reaction medium. Then, the precipitated dye is selectively dyed on the lipophilic resin particles uniformly dispersed in the reaction medium. As a result, toner particles colored at a high concentration are obtained.

As a specific method of dyeing the resin particles, for example, a powder of an oil-soluble dye, or a solution in which these dyes are dissolved or dispersed in an organic solvent used as a reaction medium, is used as a polymer. It is poured into the reaction medium in a precipitated state with stirring, and then, while heating, gradually adding water little by little using a pump or a dropping funnel into the reaction medium, whereby As mentioned, the dye is selectively dyed onto the polymer particles to obtain highly concentrated toner particles. In the present invention, it is preferable that the refluxing state of the reaction medium be maintained during the coloring treatment so that the polymer particles are colored well. Further, if necessary, an adjustment for optimizing the heating temperature in the reaction vessel may be performed. At this time, the heating temperature and the heating time depend on the type and amount of the material to be used.
The temperature may be maintained at 70 to 100 ° C. for 3 hours.

When the colorant is added to the reaction medium in the state where the polymer is precipitated, the amount of water to be added slowly when water is added slowly is theoretically better, but the size of the reaction vessel and the dyeing Taking into account the time it takes to wear, 0.5
It is preferable to set it to about 2.0 to 2.0 times. Further, it is preferable to use distilled water as the water. In the present invention, the slower the addition rate of water, the better. However, in the case where the addition rate is increased from the viewpoint of efficiency, particularly, due to the rapid addition of water, agglomeration of water-insoluble dye or excessive precipitation. Preferably do not occur. From the balance of both,
The time required for the addition of water is preferably about 1 to 3 hours.

The colorant used in the method for producing the colored polymerization toner of the present invention is an oil-soluble dye, but as described above, a water-insoluble dye is used. Specific examples of such coloring agents include commercially available dyes such as Oil Black and Oil Color Y manufactured by Orient Chemical Industries.
yellow-3G, Yellow-GG-S, Yellow
ow- # 105, Orange-PS, Orange-
PR, Orange- # 201, Scarlet- # 3
08, Red-5B, Brown-GR, Brown-
# 416, Green-BG, Green- # 502,
Blue-BOS, Blue-IIN, Black-H
BB, Black- # 803, Black-BS, BL
ack-EB, Black-EX and the like. The concentration of the coloring agent added to the reaction vessel is preferably about 0.01 to 10% by weight based on the binder resin or the polymerizable monomer.

In the method for producing the polymerization toner of the present invention, the above-mentioned constituent materials are used. Further, in order to improve the charge stability and developability of the obtained toner, a conventionally known charge control agent is used. Can also be used. As the charge control agent used in the present invention, for example, as the positive charge control agent, a nigrosine dye, a quaternary ammonium salt, an electron donating substance such as a resin containing an amino group, and the like, and as the negative charge control agent, And electron accepting substances such as metal complex dyes and salicylic acid metal salts.

Further, in the method for producing a polymerization toner according to the present invention, a known surface modifier is used for various purposes such as improvement of fluidity of the obtained toner, improvement of image quality, and prevention of damage to a photoreceptor. The polymerizable toner particles colored as described above may be further externally added. Examples of the external additives used at this time include resin fine powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder, fatty acid metal salts such as zinc stearate, calcium stearate, and lead stearate; aluminum oxide; Metal oxides such as titanium and zinc oxide; finely divided silica such as wet-process silica and dry-process silica; or those obtained by subjecting such silica to a surface treatment with a silane coupling agent, a titanium coupling agent, silicon oil, or the like. No. In the method for producing a polymerization toner according to the present invention, a magnetic toner can be obtained by adding a magnetic substance when producing polymer particles.

[0025]

EXAMPLES Examples and comparative examples of the present invention will be described below.
The present invention will be described more specifically, but the present invention is not limited by the examples.

Example 1 This example is an example in which a polymerization reaction is carried out in an aqueous reaction medium containing water. First, a material having the following composition was charged into a 1-liter four-necked flask equipped with a reflux condenser, a thermometer, and a nitrogen inlet tube, and mixed well. -70 parts by weight of ethanol-20 parts by weight of water-10 parts by weight of polyvinyl pyrrolidone-28 parts by weight of styrene monomer-7 parts by weight of n-butyl acrylate-1 part by weight of chromium complex salt of di-tert-butylsalicylic acid-2,2 ' -Azobisisobutyronitrile 2 parts by weight Next, nitrogen gas was introduced into the flask containing the above mixture, and the inside of the vessel was sufficiently purged with nitrogen. Then, the flask was placed in an oil bath, and polymerization was carried out while heating and refluxing for 16 hours. At this time, the set temperature of the oil bath was 70 ° C. After the completion of the polymerization reaction, Oil B, which is an oil-soluble dye powder, is added to the obtained reaction mixture while stirring.
2 parts by weight of lac BS (manufactured by Orient Chemical Industries) were added. After confirming that the oil-soluble dye powder was dissolved in the solution, 140 parts by weight of distilled water was dropped at a slow rate of 1 part by weight using a cassette tube pump. The set temperature of the oil bath at this time was 90 ° C. Next, the reaction mixture after the dropwise addition was cooled at room temperature while stirring, and then subjected to suction filtration to perform solid-liquid separation of the colored resin particles. Then, the separated colored resin particles were further repeatedly washed with distilled water and filtered to wash polyvinylpyrrolidone as a polymer matrix. Thereafter, the obtained toner was vacuum-dried to obtain colored polymerized toner particles of this example.

Comparative Example 1 The oil-soluble dye powder Oil Bl was added to the reaction mixture before coloring obtained by the same operation as in Example 1 while stirring.
ack BS (manufactured by Orient Chemical Industries) was added, and after confirming that the dye powder was dissolved in the solution, about 2 parts by weight were added.
The mixture was refluxed for 20 minutes to produce colored polymerization toner particles. Further, the obtained reaction mixture was washed in the same manner as in Example 1, and then dried under vacuum to obtain colored polymerization toner particles.

(Evaluation) In order to compare the degree of coloring of the polymerizable toners obtained in Example 1 and Comparative Example 1, the respective filtrates obtained when the reaction mixture was separated by filtration and solid-liquid separation were dyed. The concentrations were measured and compared. The dye concentration was measured using a spectrophotometer (U3300, manufactured by Hitachi, Ltd.), and the filtrate obtained by filtration was diluted with distilled water to an appropriate concentration suitable for measurement, and the absorbance at 600 nm was measured. As a result, the absorbance of the filtrate obtained in Example 1 was 4.
On the other hand, the absorbance of the filtrate obtained in Comparative Example 1 was 45.45, and the method for producing a colored polymerized toner performed in Example 1 showed that the dye particles were more efficiently used. It turned out to be dyed.

Further, 1.0 g of the polymerizable toner particles obtained in Example 1 and Comparative Example 1 were each dissolved in 10 g of MEK, coated on a transparent PET sheet using a bar coater, and dried. The PET sheet thus obtained was subjected to a reflection densitometer (Macbeth densitometer RD-
1255), the reflection density value per 1 μm of film thickness was compared for the magenta component. As a result, in the case of the polymerizable toner obtained in Example 1, it was 0.221, and in Comparative Example 1, it was 0.180. This is shown in Example 1
Indicates that the dyeing is performed more efficiently.

Example 2 This example is an example in which a polymerization reaction is carried out in a non-aqueous reaction medium containing no water. First, a material having the following composition was charged into a 1-liter four-necked flask equipped with a reflux condenser, a thermometer, and a nitrogen inlet tube, and mixed well. 93 parts by weight of methanol 7 parts by weight of polyvinyl pyrrolidone 28 parts by weight of styrene monomer 7 parts by weight of 2-ethylhexyl acrylate 1 part by weight of chromium complex salt of di-tert-butylsalicylic acid 1 part by weight of 2,2'-azobisisobutyi Lonitrile 2 parts by weight Next, nitrogen gas was introduced into the flask containing the above mixture, and the inside of the vessel was sufficiently purged with nitrogen. Then, the flask was placed in an oil bath, and polymerization was carried out while heating and refluxing for 16 hours. At this time, the set temperature of the oil bath was 70 ° C. After the completion of the polymerization reaction, Oil B, which is an oil-soluble dye powder, is added to the obtained reaction mixture while stirring.
lac BS (manufactured by Orient Chemical Industries) was added, and after confirming that the oil-soluble dye powder was dissolved in the solution, 140 parts by weight of distilled water was slowly added to the solution at a rate of 1 part / minute using a cassette tube pump. It dripped at the speed set as follows. The set temperature of the oil bath at this time was 90 ° C. Next, the reaction mixture after the dropwise addition was cooled at room temperature while stirring, and then subjected to suction filtration to perform solid-liquid separation of the colored resin particles. Then, the separated colored resin particles were further repeatedly washed with distilled water and filtered to wash polyvinylpyrrolidone as a polymer matrix. Thereafter, the obtained toner was vacuum-dried to obtain colored polymerized toner particles of this example.

Comparative Example 2 The oil-soluble dye powder Oil B was added to the reaction mixture before coloring obtained by the same operation as in Example 2 while stirring.
lac BS (manufactured by Orient Chemical Industries) was added, and after confirming that the dye powder was dissolved in the solution, about 2 parts by weight were added.
The mixture was refluxed for 20 minutes to produce colored polymerized toner particles. The obtained reaction mixture was washed in the same manner as in Example 2, and dried under vacuum to obtain polymerized toner particles for comparison.

(Evaluation) In order to compare the degree of coloring of the polymerizable toners obtained in Example 2 and Comparative Example 2, the evaluations performed in Example 1 and Comparative Example 1 were similarly performed. As a result, the absorbance of the filtrate obtained in Example 2 was 0.162.
The filtrate obtained in Comparative Example 2 had an absorbance of 45.45, whereas the filtrate obtained in Comparative Example 2 had an absorbance of 45.45. It was found that the particles stained.

Further, 1.0 g of the polymerizable toner particles obtained in Example 2 and Comparative Example 2 were each dissolved in 10 g of MEK, coated on a transparent PET sheet using a bar coater, and dried. The PET sheet thus obtained was subjected to a reflection densitometer (Macbeth densitometer RD-
1255), the reflection density value per 1 μm of film thickness was compared for the black component. As a result, in the case of the polymerizable toner obtained in Example 2, it was 0.191, and in Comparative Example 2, it was 0.063. This indicates that the dyeing is performed more efficiently in the case of Example 2. Also, as a result of comparison with the case of Example 1, the effect of the present invention was better when polymerized in the non-aqueous reaction medium of Example 2 than in the aqueous reaction medium of Example 1. Was remarkably exhibited.

[0034]

As described above, according to the method for producing the colored polymerization toner of the present invention, the particle diameter is small,
Further, a polymerized toner having a sharp particle size distribution and colored at a high concentration can be easily obtained.

Claims (2)

[Claims] 1. A monomer composition containing at least a polymerizable monomer and a dispersion stabilizer is added to a reaction medium mainly containing an organic solvent, and at least the polymerizable monomer is added to the reaction medium in the reaction medium. The polymerizable monomer is polymerized in a dissolved state, and a polymer synthesized by polymerizing the polymerizable monomer is precipitated in the reaction medium, and then the polymer is colored with a coloring agent to form toner particles. In the method for producing a colored polymerization toner for producing (1), (1) a dispersion agent which is soluble in the organic solvent is used as the dispersion stabilizer, and (2) an oil-soluble dye insoluble in water is used as the colorant. And (3) heating the reaction medium in which the polymer is precipitated, adding the colorant to the reaction medium, dissolving the colorant in the reaction medium, and then adding water to the reaction medium. Coloring toner particles by adding it slowly Of producing a colored polymerization toner. 2. The method for producing a polymerization toner according to claim 1, wherein the dispersion stabilizer is soluble in a 1: 2 mixed solvent of an organic solvent and water.