JPH08234485A - Production of electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE: To decrease variation in the distribution of grain size among batches, to render a classifying process unnecessary, and to obtain a toner having sharp distribution of grain size at a high production yield by granulating the toner while monitoring the distribution of grain size with an in-line grain size distribution measuring instrument. CONSTITUTION: In the granulating process of a toner, the distribution of grain size is monitored with an in-line grain size distribution measuring instrument, and when desired distribution of grain size is obtd., the granulating process is stopped. Namely, in this case, an in-line grain size distribution measuring instrument which is generally well-known as an in-line instrument attached to a polymn. reaction tank or the like to monitor the distribution of grain size of resin or liquid drops is used for the production of a toner for which severe control of the distribution of grain size is required. As for the in-line grain size distribution measuring instrument to be used, any instrument which can monitor the distribution of grain size by in-line method can be used, and an instrument using reflective laser scanning method is preferably used.

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 toner for developing an electrostatic latent image.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, as described in US Pat. No. 2,297,691, etc.,
Although many methods are known, generally, a photoconductive material is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed with a toner, Accordingly, the toner image is transferred onto a transfer material such as paper, and then the toner image is fixed by heat or pressure to obtain a copied image. In addition, various methods have been conventionally proposed as a method of developing with a toner or a method of fixing a toner image.

Conventionally, the toners used for these purposes are generally toners having a desired particle size by a fine pulverizer and a classifier after melt-mixing a colorant consisting of dyes and pigments in a thermoplastic resin and uniformly dispersing them. Has been manufactured.

While this method of manufacture can produce fairly good toners, it does have certain limitations, ie, the choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle to be comminuted in an economically feasible manufacturing apparatus. However, if the resin colorant dispersion is made brittle in order to satisfy these requirements, the particle size range of the particles formed when actually pulverized at high speed tends to be wide,
In particular, a problem arises that a relatively large proportion of fine particles is contained in this. Further, such a brittle material is likely to undergo further fine pulverization or pulverization when used for developing such as a copying machine. Further, with this method, it is difficult to disperse solid fine particles such as a colorant into the resin completely and uniformly. Depending on the degree of dispersion, fog increases, image density decreases, and color mixing / transparency Care must be taken in dispersion as it causes defects. In addition, the exposure of the colorant on the fracture surface may cause fluctuations in the developing characteristics.

On the other hand, in order to overcome the problems of the toner by the pulverization method, Japanese Patent Publication No. 36-10231 and 4
Nos. 3-10799 and 51-14895 propose a method for producing a toner by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer, a colorant,
A polymerization initiator and, if necessary, a cross-linking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition, and the monomer composition contains a dispersion stabilizer. The particles are dispersed in a continuous phase, for example, an aqueous phase using a suitable stirrer, and a polymerization reaction is simultaneously performed to obtain toner particles having a desired particle size.

Since this method does not include a crushing step at all, the toner does not need to be brittle, a soft material can be used, and the colorant is not exposed on the surface of the particles. It has the advantage of having excellent triboelectric charging properties. Further, since the obtained toner has a relatively sharp particle size distribution, the toner can be obtained in a high yield even if the classification step is omitted or classified. In addition, since a large amount of a low softening point substance can be included in the toner as a release agent, there is an advantage that the obtained toner has excellent offset resistance.

[0007]

However, the polymerization method toner requires a granulation step and a polymerization step due to the characteristics of the manufacturing method, and it is difficult to manufacture continuously by using a pulverization method toner.
Batch production.

Therefore, although the production method is such that a relatively sharp particle size distribution can be obtained in each batch, a classification step is required to finally obtain a toner having a stable particle size distribution due to fluctuations in the particle size distribution between batches. turn into. Further, in the granulation step, the method of granulating with high shearing force can obtain a toner having a sharp particle size distribution efficiently in a relatively short time,
The amount of fine powder tends to increase as the granulation time becomes longer, which not only broadens the particle size distribution of the toner, but also in the solid-liquid separation (filtration) step that separates the dispersion medium and the toner particles later. Will increase the load on.

Therefore, the object of the present invention is to obtain a toner having a sharp particle size distribution with a high yield, in which fluctuation of the particle size distribution between batches is small, a classification step is not finally required, and even if the particles are classified. It is to provide a manufacturing method.

Another object of the present invention is a granulation step,
An object of the present invention is to provide a method for producing a toner that does not increase the load in the solid-liquid separation (filtration) step even when an efficient apparatus for granulating with high shearing force is used.

Another object of the present invention is to provide a method for producing a toner having excellent fixability.

[0012]

Means and Actions for Solving the Problems The above-mentioned object is a method for producing a toner by a polymerization method including a step of granulating a polymerizable monomer composition and a step of polymerizing, This is achieved by stopping the granulation process when the desired particle size distribution is obtained while monitoring the particle size distribution with an in-line type particle size distribution measuring device.

The present invention will be described in detail below.

As a result of diligent studies, the present inventors conducted granulation at a predetermined particle size distribution while monitoring the particle size distribution with an in-line type particle size distribution analyzer in the toner particle granulation step in the polymerization method. It was found that by stopping the process, the fluctuation of the particle size distribution between batches is small, the classification process is not finally required, and even if the classification is performed, a toner with a high particle size distribution and a sharp particle size distribution can be obtained. It was In addition, in the case of using an efficient granulator with high shearing force in the granulation process, especially when using an in-line type particle size distribution analyzer, the load in the solid-liquid separation (filtration) process can be increased. It was found that a high yield toner having a sharp particle size distribution was obtained.

As described above, the polymerization toner is a batch type production due to the characteristics of its production method. Therefore, even though it is a manufacturing method that can obtain a relatively sharp particle size distribution in each batch, a classification step is necessary to finally obtain a toner having a stable particle size distribution due to fluctuations in the particle size distribution between batches. I will end up.

Conventionally, in order to solve these problems, it is possible to control the granulation conditions (time, temperature, the number of revolutions of the granulator, etc.) and observe the toner particles with a microscope for small-scale production. Although it is possible to deal with the problem to some extent, the above condition management becomes difficult due to the scale-up of the device accompanying mass production.

Further, in the granulation step, the method of granulating with high shearing force is a means for obtaining a toner having a sharp particle size distribution efficiently in a relatively short time. Tends to increase, which not only broadens the particle size distribution of the toner, but also increases the load in the solid-liquid separation (filtration) step of separating the toner particles after the dispersion medium, When such a granulator is used, the particle size distribution can be measured in real time, and it is necessary to stop the granulation process.

As a means for solving these problems, it was found that it is effective to use an in-line type particle size distribution measuring device. An in-line type particle size distribution measuring device is generally known as a device that can be attached to a polymerization reaction tank or the like to monitor the particle size distribution of resin or droplets in line, but the feature of the present invention is that strict control of the particle size distribution is required. It has been applied to the production of toners. As a result, the difference in particle size distribution between batches is reduced, the classification step can be omitted, and even if the particles are classified, a high yield of toner can be obtained. Furthermore, when combined with a granulator using a high shearing force, which is useful in the granulation process, generation of fine powder can be suppressed, the load in the solid-liquid separation (filtration) process described above can be reduced, and efficient toner production can be achieved. It will be possible. Furthermore, in the case of producing a toner having a core / shell structure and a shell portion formed by polymerization so as to have both fixability and blocking resistance, a low softening point substance is contained in each toner particle in the same proportion. However, it is important to control the granulation time and particle size distribution in this respect as well.

The in-line type particle size distribution measuring device used in the present invention may be of any type as long as it can monitor the particle size distribution by an in-line type, but the one using the reflection type laser scanning method is preferably used. it can. Since the particle size distribution obtained by such an in-line type particle size distribution measuring device changes depending on the measurement conditions such as the mounting position of the detector, the average particle size A in the present invention is the weight average of the particle size distribution obtained by the Coulter counter described later. The particle size was adjusted. In the present invention, it is preferable to stop the granulation step at a stage when the ratio of the particle size of 3 A or more is 10% or less of the entire distribution where the average particle size is A. 1
If the granulation step is stopped in the state of exceeding 0%, the particle size distribution of the obtained toner becomes broad, which is not preferable.

The average particle diameter of the toner is preferably 3 to 20 μm, and the number variation coefficient thereof is preferably 40% or less.

The apparatus for granulating with high shearing force used in the present invention may be any apparatus such as TK homomixer (manufactured by Tokushu Kika Kogyo) as long as it is capable of granulating with high shearing force.

When the toner has a core / shell structure, a substance having a low softening point is preferable as the main component of the core portion, and the main maximum peak value measured according to ASTM D3418-8 is 40 to 90 ° C. The compounds shown are preferred. If the maximum peak is less than 40 ° C., the self-aggregating force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable. On the other hand, if the maximum peak exceeds 90 ° C., the fixing temperature becomes high, which is not preferable. Further, when the temperature of the maximum peak value is high, the low softening point substance is mainly precipitated during granulation, which hinders the suspension system, which is not preferable.

In measuring the temperature of the maximum peak value of the present invention,
For example, Perkin Elmer DSC-7 is used. The melting point of indium and zinc is used to correct the temperature of the device detection unit, and the heat of fusion of indium is used to correct the amount of heat. An aluminum pan was used as a sample, an empty pan was set as a control, and measurement was performed at a temperature rising rate of 10 ° C./min.

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

Further, the low softening point substance is added to the toner in an amount of 5 to 30
Addition by weight% is preferable. If it is added in an amount of less than 5% by weight, the above-mentioned residual monomer removal is burdened,
On the other hand, when it exceeds 30% by weight, even in the production by the polymerization method, toner particles are likely to coalesce with each other during granulation, and particles having a wide particle size distribution are likely to be produced, which is not suitable for the present invention.

As a concrete method for encapsulating the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than for the main monomer, and a small amount of a resin having a large polarity or By adding a monomer, a toner having a so-called core / shell structure in which a low softening point substance is coated with an outer shell resin can be obtained. Toner particle size distribution control and particle size control are performed by changing the type and addition amount of a sparingly water-soluble inorganic salt or dispersant that acts as a protective colloid, mechanical device conditions,
For example, the toner of the present invention can be obtained by controlling the stirring conditions such as the peripheral speed of the rotor, the number of passes, the shape of stirring blades, the shape of the container, or the solid content concentration in the aqueous solution.

As a specific method for measuring the tomographic plane of the toner in the present invention, a cured product obtained by sufficiently dispersing the toner in an epoxy resin which is curable at room temperature and then curing it in an atmosphere at a temperature of 40 ° C. for 2 days Was stained with ruthenium tetraoxide and, if necessary, osmium tetraoxide in combination, a thin sample was cut out using a microtome equipped with diamond teeth, and the toner morphology was measured using a transmission electron microscope (TEM). . In the present invention, it is preferable to use the ruthenium tetroxide dyeing method in order to make a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell.

The polymerizable monomer used in the present invention includes styrene, o (m-, p-)-methylstyrene, m
Styrene-based monomers such as (p-)-ethylstyrene; methyl (meth) 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 , (Meth) acrylic acid dimethylaminoethyl, (meth) acrylic acid diethylaminoethyl, and other (meth) acrylic acid ester-based monomers; butadiene, isoprene, cyclohexene, (meth) acrylonitrile, acrylic acid amide, and other ene-based monomers The body is preferably used. These may be used alone or generally in the publication Polymer Handbook Second Edition III-P 139-192 (John Wile).
theoretical glass transition temperature (T
g) is used by appropriately mixing the monomers so that it shows 40 to 80 ° C. When the theoretical glass transition temperature is lower than 40 ° C, problems occur from the viewpoint of storage stability of the toner and durability stability of the toner. On the other hand, when it exceeds 80 ° C, the fixing point is increased, especially in the case of full-color toner. In the case of (3), the color mixture of each color developer is insufficient and the color reproducibility is poor.
It is not preferable from the viewpoint of high image quality because it significantly reduces the transparency of the HP image.

The molecular weight of the binder resin (outer shell resin) is GPC.
It is measured by (gel permeation chromatography). As a specific method for measuring GPC, after the developer was extracted with a Soxhlet extractor in a toluene solvent for 20 hours in advance, the toluene was distilled off with a rotary evaporator, and the low softening point substance was dissolved, but the outer shell was dissolved. The resin is an insoluble organic solvent such as chloroform, and after thorough washing, a solution soluble in THF (tetrahydrofuran) is filtered through a solvent-resistant membrane filter with a pore size of 0.3 μm to produce a sample manufactured by Waters. 1
50C is used, and the column configuration is Showa Denko A-801, 8
02, 803, 804, 805, 806, 807 can be connected and the molecular weight distribution can be measured using the calibration curve of a standard polystyrene resin. Number average molecular weight (Mn) of the obtained resin component
Is 5,000 to 1,000,000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / M
n) is preferably an outer shell resin showing 2 to 100 in the present invention.

In the present invention, when a toner having a core / shell structure is produced, it is particularly preferable to add a polar resin in addition to the outer shell resin in order to encapsulate the low softening point substance in the outer shell 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. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with the shell resin or the monomer in the molecule. In the case of containing a polar resin having an unsaturated group, a crosslinking reaction occurs with a monomer forming the outer shell resin layer, resulting in an extremely high molecular weight as a full-color toner, which is disadvantageous for color mixing of four-color toner, which is not preferable. .

Further, in the present invention, the outermost shell resin layer may be further provided on the surface of the toner.

The glass transition temperature of the outermost shell resin layer is designed to be equal to or higher than the glass transition temperature of the outer shell resin layer in order to further improve the blocking resistance, and is crosslinked to such an extent that the fixability is not impaired. It is preferable. Further, it is preferable that the outermost shell resin layer contains a polar resin and a charge control agent in order to improve the charging property.

The method for providing the outermost shell layer is not particularly limited, but the following method may be mentioned, for example.

1) After the latter half of the polymerization reaction or after the completion of the polymerization reaction, if necessary, a monomer in which a polar resin, a charge control agent, a cross-linking agent, etc. are dissolved and dispersed is added and adsorbed on the polymer particles to give a polymerization initiator. Method of adding and polymerizing.

2) If necessary, emulsion-polymerized particles or soap-free polymerized particles composed of a monomer containing a polar resin, a charge control agent, a cross-linking agent, etc. are added to the reaction system to aggregate on the surface of the polymerized particles, if necessary. According to the method of fixing by heat.

3) A method of mechanically adhering emulsion-polymerized particles or soap-free polymerized particles composed of a monomer containing a polar resin, a charge control agent, a cross-linking agent, etc., to the surface of the toner particles by a dry method, if necessary.

As the colorant used in the present invention, carbon black, a magnetic substance, or a yellow / magenta / cyan colorant shown below, which is toned black, is used.

As the yellow colorant, condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and the like are preferably used.

As the magenta colorant, a condensed azo compound, a diketopyrrolopyrrole compound, an anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound, and a perylene compound are used. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
44, 146, 166, 169, 177, 184, 18
5,202,206,220,221,254 are particularly preferred.

As the cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.

These colorants may be used alone or in combination, and may be used in the form of solid solution. The colorant of the present invention is selected in terms of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in a developer. The colorant is added in an amount of 1 to 20 parts by weight based on 100 parts by weight of the resin.

When a magnetic material is used as the black colorant, unlike the other colorants, the amount is 40 with respect to 100 parts by weight of the resin.
Used up to 150 parts by weight.

The charge control agent used in the present invention includes
Although known compounds can be used, a charge control agent that is colorless and has a high charging speed of the developer and that can stably maintain a constant charge amount is preferable. Furthermore, when the direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibitory property and having no solubilized product in an aqueous system is particularly preferable. Specific compounds include metal compounds of salicylic acid, naphthoic acid, dicarboxylic acid, sulfonic acid, polymer compounds having a carboxylic acid as a side chain, boron compounds, urea compounds, silicon compounds, currys arenes, etc. as negative compounds. A quaternary ammonium salt, a polymer type compound having a side chain of the quaternary ammonium salt, a guanidine compound, an imidazole compound or the like is preferably used as a positive system. The charge control agent is resin 10
0.5 to 10 parts by weight is preferable with respect to 0 parts by weight. However, the addition of the charge control agent is not essential in the present invention, and when the two-component developing method is used, the frictional charging with the carrier is used, and the blade is used even when the non-magnetic one-component blade coating developing method is used. By positively utilizing the triboelectric charging with the member or the sleeve member, it is not always necessary to include the charge control agent in the toner.

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

It is also possible to further add and use a known crosslinking agent, chain transfer agent, polymerization inhibitor or the like in order to control the degree of polymerization.

When suspension polymerization is used in the toner production method of the present invention, the dispersant used is, for example, an inorganic oxide such as tricalcium phosphate, 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, magnetic material, ferrite and the like.
As the organic compound, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like can be dispersed in the aqueous phase and used. It is preferable to use 0.2 to 10.0 parts by weight of these dispersants with respect to 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 dispersed particles having a fine and uniform particle size, the inorganic compound may be produced under high speed stirring in a dispersion medium. it can. For example, in the case of tricalcium phosphate, a dispersant suitable for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high speed stirring.

In order to make these dispersants fine,
You may use together 001-0.1 weight part surfactant.
Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. 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.

That is, a releasing agent, a colorant, a charge control agent, a polymerization initiator and other additives made of a substance having a low softening point are added to a polymerizable monomer and uniformly dissolved by a homogenizer, an ultrasonic disperser or the like. Alternatively, the dispersed monomer system is dispersed with a homomixer or the like while monitoring with an in-line type particle size distribution analyzer in an aqueous phase containing a dispersion stabilizer. The granulation is stopped when the droplets of the monomer composition have the desired toner particle size. After that, stirring may be performed to the extent that the particle state is maintained and the particles are prevented from settling due to the action of the dispersion stabilizer. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 to 90 ° C. for polymerization. Further, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products and the like, the aqueous medium is partially distilled off in the latter half of the reaction or after the reaction is completed. Is also good. After the reaction is completed, the produced toner particles are collected by washing and filtration and dried. In the suspension polymerization method, 300 to 3 parts of water is usually added to 100 parts by weight of the monomer system.
It is preferred to use 000 parts by weight as the dispersion medium.

The external additive used for the purpose of imparting various toner characteristics is preferably a particle diameter of 1/10 or less of the weight average diameter of the toner particles from the viewpoint of durability when added to the toner. . The particle size of this additive has the average particle size obtained by observing the surface of the toner particles with an electron microscope. As the external additive, for example, the following ones are used.

Metal oxides (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.),
Metal salts (calcium sulfate, barium sulfate, calcium carbonate, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, silica, etc.

These external additives are used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the toner particles. These external additives may be used alone or in combination. Those subjected to a hydrophobic treatment are more preferable.

The average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.). In the present invention, Coulter Counter TA-I is used.
PC (980) interface (made by Nikkaki) that outputs number distribution and volume distribution using I type (made by Coulter)
1 Personal computer (manufactured by NEC) is connected, and a 1% NaCl aqueous solution is prepared by using primary sodium chloride as an electrolytic solution. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, the electrolytic aqueous solution is 100 to 150 m.
A surfactant, preferably 0.1 to 5 ml of alkylbenzene sulfonate is added as a dispersant to 1 l, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes.
Using a 00 μm aperture, the volume and number of toner particles of 2 μm or more were measured to calculate the volume distribution and number distribution.
Then, the weight average particle diameter on a volume basis obtained from the volume distribution of at according to the present invention (D _4: the representative value of the channel center value of each channel) and weight coefficient of variation (S _4), determined from number distribution The number-based length average particle diameter (D ₁ ) and the length variation coefficient (S ₁ ) were determined.

The image density is a numerical value obtained by measuring (5 mm square, 5 mm circle, solid black) with a Macbeth densitometer (manufactured by Macbeth Co.).

[0055]

EXAMPLES The present invention will be described in more detail with reference to specific manufacturing methods, examples and comparative examples.

[Preparation Example A of Colored Suspended Particles] 7200 g of 0.1M Na ₃ PO ₄ aqueous solution was added to 1140 g of ion-exchanged water.
Was charged, and after heating to 60 ° C., the mixture was stirred at 9000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). To this, 1090 g of 1.0 M-CaCl ₂ aqueous solution
Was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, (monomer) styrene 2640 g n-butyl acrylate 560 g (colorant) C.I. I. Pigment Blue 15: 3 250 g (charge control agent) salicylic acid metal compound 40 g (polar resin) saturated polyester 150 g (acid value 10, peak molecular weight; 7500) (release agent) ester wax (melting point 70 ° C.) 500 g

The above formulation was heated to 60 ° C. and uniformly dissolved and dispersed at 9000 rpm using a TK homomixer (made by Tokushu Kika Kogyo). In addition to this, the polymerization initiator 2,2 '
-Azobis (2,4-dimethylvaleronitrile) 150
g was dissolved to prepare a polymerizable monomer composition.

The above polymerizable monomer composition was charged into the above aqueous medium, and the mixture was monitored at 60 ° C. in a N ₂ atmosphere while monitoring the particle size distribution, while using a TK homomixer to obtain 900.
The polymerizable monomer composition was granulated by stirring at 0 rpm. Granulation was stopped when the average particle size was 6.6 μm and 8% was 20 μm or more (granulation time: 7.8 minutes). Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. and the reaction was performed for 10 hours. After the completion of the polymerization reaction, residual monomers were distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve calcium phosphate, followed by filtration, washing with water and drying to obtain colored suspended particles A.

[Production Examples B to E of Colored Suspended Particles] Production Example A
Colored Suspended Particles B to E were obtained under the same formulation and conditions. The granulation time of each colored particle is as follows: Particle B: 7.1 minutes, Particle C:
8.4 minutes, particle D: 8.0 minutes, particle E: 8.9 minutes.

Example 1 Colored suspension particles A to E were mixed and the particle size distribution was measured with a Coulter counter. The weight average particle size was 6.7 μm and the coefficient of variation was 33%. Observation of the toner layer surface confirmed a core / shell structure.

BE was added to 100 parts by weight of the obtained particles.
Hydrophobic silica having a specific surface area of 200 m ² / g by the T method was externally added to obtain a suspension polymerization toner 1. 95 parts by weight of an acrylic-coated ferrite carrier was mixed with 5 parts by weight of this toner to obtain a developer. When this developer was used to evaluate the continuous printing of 5000 sheets with a modified CLC500 full-color copying machine manufactured by Canon, no fog was observed, the image density was stable, and good images were obtained.

[Production Examples F to J of Colored Suspended Particles] Production Example A
With the same formulation as above, the granulation time was fixed to 8 minutes (the average granulation time when the colored suspension particles A to E were produced) without using a particle size distribution measuring device, and the same operation was performed thereafter for coloring. Suspended particles F
I got ~ J.

Comparative Example 1 Colored suspension particles F to J were mixed and the particle size distribution was measured with a Coulter counter. The weight average particle diameter was 7.1 μm and the coefficient of variation was 42%.

BE was added to 100 parts by weight of the obtained particles.
Hydrophobic silica having a specific surface area of 200 m ² / g by the T method was externally added to obtain a suspension polymerization toner 2. 95 parts by weight of an acrylic-coated ferrite carrier was mixed with 5 parts by weight of this toner to obtain a developer. When this developer was used to evaluate the continuous printing of 5,000 sheets with a full-color copying machine CLC500 modified by Canon, the result was 3,000.
Fogging occurred from around the sheet.

[0066]

As described above, according to the present invention,
The fluctuation of the particle size distribution between batches is small, a classification step is not finally required, and even if the particles are classified, a high yield toner having a sharp particle size distribution can be obtained.

Claims (6)

[Claims] 1. A method for producing a toner by a polymerization method, which comprises a step of granulating a polymerizable monomer composition and a step of polymerizing, wherein an in-line type particle size distribution analyzer is used in the granulating step. A method for producing a toner for developing an electrostatic charge image, which comprises granulating while monitoring a particle size distribution. 2. In the particle size distribution obtained by the granulation process, the granulation process is stopped when the ratio of the particle size of 3 A or more is 0 to 10% of the entire distribution when the average particle size is A. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein 3. The method for producing an electrostatic charge image developing toner according to claim 1, wherein granulation is performed by applying a high shearing force in the granulation step. 4. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the toner has a core / shell structure. 5. The toner for developing an electrostatic charge image according to claim 4, wherein the main component of the core part is a low softening point substance, and the melting point of the low softening point substance is 40 to 90 ° C. Production method. 6. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the in-line type particle size distribution measuring device uses a reflection laser scanning method.