JP4012083B2 - Toner production method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner manufacturing method used in an image forming method for revealing an electrostatic latent image and a toner jet recording method.
[0002]
[Prior art]
Conventionally, a number of methods are known as electrophotographic methods. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is formed with toner. Development is performed to make a visible image, and a toner image is transferred to a transfer material such as paper as necessary. Then, the toner image is fixed on the transfer material by heat or pressure to obtain a copy or printed matter. .
[0003]
Various methods have been proposed for developing with toner or fixing a toner image.
[0004]
Conventionally, toners used for these purposes are generally obtained by melt-kneading a colorant composed of a dye or pigment in a thermoplastic resin, uniformly dispersing it, and then finely pulverizing it with a fine pulverizer. Toner having a desired particle size has been produced by classification with a classifier.
[0005]
Although this method of manufacture can produce fairly good toner, there are certain limitations, i.e., limited choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized with economically possible production equipment. However, if the resin colorant dispersion is made brittle in order to satisfy these requirements, when the dispersion is actually pulverized at high speed, the particle size range of the formed particles tends to be widened, and in particular, a relatively large proportion of fine particles Is included in this.
[0006]
Further, the toner obtained from such a brittle material is likely to be further pulverized or powdered in a developing device such as a copying machine. Also, with this method, it is difficult to completely disperse solid fine particles such as a colorant in the resin. Depending on the degree of dispersion, an increase in fog at the time of image formation, a decrease in image density, color mixing, or transparency Sufficient attention must be paid to the dispersion of the colorant, as this can cause poor color.
[0007]
On the other hand, in order to overcome the problems of the toner by the pulverization method, a toner by chemical synthesis and a manufacturing method thereof have been proposed, including suspension polymerization method toners disclosed in Patent Publications 1-3. For example, in a suspension polymerization toner, a monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer, a colorant and a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives. After that, the monomer composition is dispersed in a medium containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and at the same time, a polymerization reaction is carried out, followed by filtration and drying. Toner particles having a particle size are obtained. In addition, in the emulsion aggregation method toner, the monomer is emulsion-polymerized in a liquid to which an emulsion of necessary additives is added to produce fine polymer particles, and then an organic solvent, an aggregating agent, etc. are added. And can be manufactured by the method of meeting together. A method of preparing by mixing with a dispersion liquid such as a release agent and a colorant necessary for the composition of the toner at the time of association, and a toner component such as a release agent and a colorant dispersed in the monomer And then emulsion polymerization. The steps after filtration and drying can be performed in the same manner as in the suspension polymerization method. Here, the term “association” means that a plurality of resin particles and colorant particles are fused. In general, a toner by chemical synthesis such as a suspension polymerization toner and an emulsion aggregation toner is referred to as a polymerization toner or a polymerization toner. In these methods, the toner does not need to be brittle, and a soft material can be used as the resin. Further, no colorant is exposed to the particle surface, and a toner having uniform triboelectric chargeability can be obtained. There is an advantage. In addition, since the toner particle size distribution obtained is relatively sharp, the toner can be obtained in a high yield in the classification process, so that the cost reduction effect such as energy saving, time reduction, and process yield improvement is great. Further, since a large amount of a low softening point substance can be encapsulated in the toner as a release agent, there is an advantage that the obtained toner has excellent offset resistance.
[0008]
As described above, the polymerization toner is superior in particle size distribution than the pulverized toner, but in order to realize high-definition images in recent years, a sharper particle size distribution is required, and classification is also performed in the polymerization toner. The treatment of non-predetermined non-prescribed particles has been a problem. Patent Document 4 discloses a method in which predetermined outer particles are dissolved in a polymerizable monomer, insoluble components are removed by filtration, and only soluble components are reused. However, since the process is complicated, it is economical. It was not an excellent method of reuse.
[0009]
[Patent Document 1]
Japanese Patent Publication No. 36-10231 [Patent Document 2]
Japanese Patent Publication No. 43-10799 [Patent Document 3]
Japanese Patent Publication No. 51-14895 [Patent Document 4]
JP-A-5-188642 [0010]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a method for producing a toner having a sharp particle size distribution capable of realizing a high-definition image.
[0011]
Another object of the present invention is to provide a method of reusing predetermined outer particles of toner that is excellent in economic efficiency.
[0012]
[Means for Solving the Problems]
The above object is achieved by the present invention described below.
[0013]
That is, the present invention is a method for producing a toner synthesized in an aqueous medium,
And a step of pulverizing or pulverizing coarse particles separated in the classification step to obtain toner particles having a predetermined particle size ,
The toner particles having a predetermined particle size by pulverization or crushing are mixed with toner particles having a predetermined particle size obtained without being separated as coarse particles at a ratio of 1: 100 to 20: 100. a method for producing a toner according to claim to Rukoto.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
[0015]
In order to solve the above-described problems of the prior art, the present inventors have closely observed the predetermined outer particles separated in the polymerization toner classification step. When the ratio of the predetermined outer particles is calculated on a volume basis, We found that the particles were the main. Further, when the coarse particles are closely observed, the coarse particles are divided into a case of one giant particle and a case where a plurality of predetermined inner particles are aggregated. It was found that the particles occupied a large number. Furthermore, it has been found that coarse particles in which a plurality of predetermined inner particles are aggregated can be obtained as a plurality of predetermined inner particles by loosening the aggregation in a slight physical impact, that is, a pulverization step or a crushing step.
[0016]
When loosening the agglomeration, some of the particles are pulverized by volume, so that the mixing ratio with the normal product is preferably 20: 100 or less. In addition, when the ratio is 1: 100 or less, the investment amount required for adding the crushing or crushing process cannot be recovered, so the mixing ratio is preferably 1: 100 to 20: 100.
[0017]
Compared with the disposal costs and recycling costs of coarse particles that have been disposed of or regenerated in the past, the recycling process of the present invention is only economical for the introduction of a crusher or crusher, so it has excellent economic effects. .
[0018]
The following is a detailed description.
[0019]
The toner of the present invention contains at least a resin and a colorant, but may contain a release agent, a charge control agent, or the like, which is a fixability improving agent, if necessary. Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the toner particles containing the resin and the colorant as main components.
[0020]
In the toner of the present invention, a monomer is emulsion-polymerized in a suspension polymerization method or a liquid obtained by adding an emulsion of necessary additives to produce fine polymer particles. It can manufacture by the method of adding an agent etc. and making it associate. A method of preparing by mixing with a dispersion liquid such as a release agent and a colorant necessary for the composition of the toner at the time of association, and a toner component such as a release agent and a colorant dispersed in the monomer And a method of emulsion polymerization. Here, the term “association” means that a plurality of resin particles and colorant particles are fused.
[0021]
Moreover, the aqueous medium as used in the field of this invention shows the thing containing 50 mass% or more of water at least.
[0022]
Although it does not specifically limit as a manufacturing method of a suspension polymerization method, The following manufacturing methods can be raised.
[0023]
That is, various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and then a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser, etc. Various constituent materials are dissolved or dispersed in the polymerizable monomer. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in oil droplets of a desired size as a toner in an aqueous medium containing a dispersion stabilizer using a homomixer or a homogenizer. Then, it transfers to the reaction apparatus which has a stirring mechanism, and a polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention.
[0024]
Further, as a method for producing the toner of the present invention, a method of preparing by fusing resin particles in an aqueous medium can also be mentioned. The method is not particularly limited, and examples thereof include methods described in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904. That is, a method of associating a plurality of dispersed particles of constituent materials such as resin particles and a colorant, or a plurality of fine particles composed of a resin and a colorant, particularly after dispersing them in water using an emulsifier, the critical aggregation concentration The toner of the present invention is obtained by adding the above flocculant and salting out, and simultaneously heat-melting the formed polymer itself at a temperature equal to or higher than the glass transition temperature, and heating and drying the particles in a fluid state while containing water. Can be formed. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the flocculant.
[0025]
Specific examples of preferable monomers used in the present invention include styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid ester monomers such as behenyl acid, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) An ene monomer such as acrylonitrile and acrylamide is preferably used. These monomers are used alone or generally so that the theoretical glass transition temperature (Tg) described in the publication polymer handbook 2nd edition III-P139-192 (John Wiley & Sons) is 40-75 ° C. It is used by mixing appropriately. When the theoretical glass transition temperature is less than 40 ° C., there are problems in terms of storage stability of the toner and durability of the developer. On the other hand, when it exceeds 75 ° C., the fixing point is increased. In some cases, the color toners are not sufficiently mixed, resulting in poor color reproducibility. Further, the transparency of the OHP image is remarkably lowered, which is not preferable from the viewpoint of high image quality.
[0026]
The molecular weight of the outer shell resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, toner is extracted with a toluene solvent for 20 hours in advance using a Soxhlet extractor, and then toluene is distilled off with a rotary evaporator. Further, the low softening point substance is dissolved but the outer shell resin is dissolved. After washing thoroughly with an organic solvent that cannot be dissolved, such as chloroform, a sample obtained by filtering a solution soluble in THF (tetrahydrofuran) with a solvent-resistant membrane filter having a pore size of 0.3 μm was manufactured by Waters. Using 150C, the column configuration can connect A-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko and measure the molecular weight distribution using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5,000 to 100,000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) is 2-100. Preferred for the invention.
[0027]
In the present invention, when a toner having a core / shell structure is produced, it is particularly preferable to further add a polar resin to the outer shell resin in order to encapsulate the low softening point substance.
[0028]
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. The polar resin is particularly preferably one that does not contain much unsaturated groups that can react with the outer shell resin or monomer. If a polar resin having many unsaturated groups is included, a cross-linking reaction occurs with the monomer forming the outer shell resin layer. This is disadvantageous and not preferable.
[0029]
In the present invention, an outermost resin layer may be further provided on the toner surface. The glass transition temperature of the outermost shell resin layer is preferably designed to be higher than the glass transition temperature of the outer shell resin layer in order to further improve the blocking resistance, and is preferably crosslinked to such an extent that the fixing property is not impaired. . Further, the outermost resin layer preferably contains a polar resin or a charge control agent in order to improve chargeability.
[0030]
The method for providing the outermost shell layer is not particularly limited, and examples thereof include the following methods.
1. In the latter half of the polymerization reaction or after completion, if necessary, add a monomer in which a polar resin, charge control agent, cross-linking agent, etc. are dissolved and dispersed in the reaction system and adsorb to the polymer particles, and then add a polymerization initiator to perform polymerization. How to do.
2. If necessary, emulsion-polymerized particles or soap-free polymerized particles consisting of monomers containing a polar resin, a charge control agent, a crosslinking agent, etc. are added to the reaction system and aggregated on the surface of the polymerized particles. How to fix.
3. A method in which emulsion-polymerized particles or soap-free polymerized particles comprising monomers containing a polar resin, a charge control agent, a crosslinking agent, etc. are mechanically fixed to the toner particle surface in a dry manner as required.
It is.
[0031]
As the colorant used in the present invention, a black colorant that is toned in black using carbon black, a magnetic material, and the following yellow / magenta / cyan colorant is used.
[0032]
As the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, etc. are preferably used.
[0033]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.
[0034]
As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, 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.
[0035]
These colorants can be used alone or in combination and further in the form of a solid solution.
[0036]
In the case of a color toner, the colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.
[0037]
When a magnetic material is used as the black colorant, it is used by adding 4 to 150 parts by mass with respect to 100 parts by mass of the resin, unlike other colorants.
[0038]
As the charge control agent used in the present invention, known ones can be used. In the case of a color toner, in particular, a charge control agent that is colorless and has a high toner charging speed and can stably maintain a constant charge amount. preferable. Specific examples of the negative compounds include salicylic acid, naphthoic acid, dicarboxylic acid metal compounds, sulfonic acid, polymer compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene, and the like. As a positive system, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, and the like are preferably used. The charge control agent is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin.
[0039]
Examples of the polymerization initiator used in the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, and 1,1′-azobis (cyclohexane). -1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo-based polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, Peroxide-based polymerization initiators such as cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide are used.
[0040]
The addition amount of the polymerization initiator varies depending on the target degree of polymerization, but generally 0.5 to 20% by mass is added to the monomer. The kind of the initiator is slightly different depending on the polymerization method, but can be used alone or mixed with reference to the 10-hour half-life temperature. Further, 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.
[0041]
In the toner production method of the present invention, it is preferable that the dispersion stabilizer used in the polymerization is an acid-soluble inorganic oxide. Furthermore, the inorganic oxide is preferably a phosphoric acid compound. Examples of the phosphate compound include tricalcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate. These dispersion stabilizers are preferably used in an amount of 0.2 to 10.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.
[0042]
Further, as the dispersion stabilizer, a commercially available one may be used as it is. However, in order to obtain dispersed particles having a fine uniform particle size, the inorganic compound is produced under high-speed stirring in a dispersion medium. It can also be used. For example, in the case of tricalcium phosphate, a dispersion stabilizer preferable 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. Moreover, you may use together 0.001-0.1 mass part surfactant for refinement | miniaturization of these dispersion stabilizers.
[0043]
Specific examples of the surfactant include commercially available nonionic, anionic, and cationic surfactants such as sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, and lauric acid. Sodium, potassium stearate, calcium oleate and the like are preferably used.
[0044]
An external additive may be added to the toner of the present invention to impart various toner performances. Examples of external additives used include metal oxides (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.) and nitrides (silicon nitride, etc.) Carbide (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. are used.
[0045]
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 toner particles. These external additives may be used alone or in combination. Those subjected to hydrophobic treatment are more preferable.
[0046]
A method for reusing coarse particles, which is a feature of the present invention, will be specifically described with reference to the drawings. FIG. 1 shows an example of the flow of the toner manufacturing apparatus used in the present invention, but the present invention is not limited to this flow. The present invention comprises the following steps.
[0047]
A polymerizable monomer, a colorant, a release agent and a charge control agent are mixed to prepare a polymerizable monomer composition (dispersion / dissolution step). The polymerizable monomer composition is charged into a dispersion medium containing a dispersion stabilizer and stirred to form droplets of the polymerizable monomer composition (granulation step). The droplets of the polymerizable monomer composition are polymerized to generate a suspension of polymerized monomer composition polymer particles (polymerization step). The polymerization initiator can be added to any of the dispersion / dissolution step, granulation step, and polymerization step after being dissolved in the polymerizable monomer as necessary. The suspension of polymerized particles of the polymerizable monomer composition is distilled to reduce unreacted monomers (distillation step). Coarse particles are separated from the suspension after distillation by a classification means such as a drum screen (first classification step). Acid or alkali is injected into the suspension that has passed through the first classification step, the dispersion stabilizer is dissolved, and dehydration and washing are repeated to form a wet toner (filter washing step). Moisture of the wet toner and, if necessary, volatile components such as polymerizable monomers are removed to form dry toner particles (drying step). Coarse particles and fine particles are separated from the dry toner particles by means of an airflow classifier or the like to form toner particles (second classification step). An external additive such as inorganic fine particles or organic fine particles is added to the toner particles to obtain a toner (external addition step). The coarse particles separated in the first classification step and the second classification step are pulverized or pulverized by means such as a jet pulverizer or a mechanical pulverizer (pulverization / disintegration step).
[0048]
Note that the fine particles separated in the second classification step are separately treated as necessary.
[0049]
As a classification means that can be used in the first classification step, a classifier using a screen is preferable. As a classifier using a screen, in addition to the drum screen, Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (manufactured by Deoksugaku Kosakusho); Vibrasonic System (manufactured by Dalton Co.); Soniclean (new) Used by Toyo Kogyo Co., Ltd.); turbo screener (manufactured by Turbo Kogyo Co., Ltd.); micro shifter (manufactured by Kanno Sangyo Co., Ltd.); circular vibrating sieve; high volter (manufactured by Shin Tokyo Machinery Co., Ltd.); it can.
[0050]
As a classifying means that can be used in the second classifying step, in addition to the classifier using the screen, an air classifier using a corunder effect and a classifier using a centrifugal force can be used. Elbow Jet (manufactured by Nippon Steel Mining Co., Ltd.) as an airflow classifier using the corander effect, DS classifier (manufactured by Nippon Pneumatic Co., Ltd.) as a classifier using centrifugal force; ATP classifier, TSP classifier, A TTSP classifier (manufactured by Hosokawa Micron) or the like can be used.
[0051]
As a pulverizer that can be used in the pulverization / disintegration step, a jet pulverizer, a mechanical pulverizer, or the like can be used. A jet crusher (Nippon Pneumatic Co., Ltd. IDS) or the like can be used. As the mechanical pulverizer, a turbo mill manufactured by Turbo Industry Co., Ltd., a kryptron manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nissin Engineering Co., Ltd., an inomizer manufactured by Hosokawa Micron Co., Ltd., or the like can be used.
[0052]
A Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter, Inc.) is used as a measuring device for the toner flat diameter and particle size distribution. As the electrolyte, first grade sodium chloride is used to prepare an approximately 1% NaCl aqueous solution.
[0053]
As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added.
[0054]
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toners are measured by using the measuring apparatus with a 100 μm aperture as the aperture. Distribution was calculated.
[0055]
Then, a weight-based weight average particle diameter (D4) obtained from the volume distribution according to the present invention (representing the representative value of each channel as the representative value for each channel) was obtained.
[0056]
In the present invention, the water content is obtained by collecting 5 g of water-containing particles in an aluminum dish, precisely weighing it (A [g]), leaving it in a dryer set at 105 ° C. for 1 hour, g]), and a value calculated by the following equation.
Water content = ((A−B) / A) × 100 [%]
[0057]
【Example】
The basic configuration and features of the present invention have been described above. Hereinafter, the present invention will be described more specifically with reference to examples of the present invention and comparative examples. However, of course, this does not limit the present invention.
[0058]
<Example 1>
1235 g of Na ₃ PO ₄ .12H ₂ O was added to 95 kg of ion-exchanged water, heated to 60 ° C., and then stirred at 3,700 rpm using a CLEARMIX stirrer (manufactured by M Technique). An aqueous solution containing 716 g of CaCl ₂ · 2H ₂ O dissolved in 5 kg of ion exchange water was gradually added thereto to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .
[0059]
Styrene 12000g
n-Butyl acrylate 2500g
C. I. Pigment Blue 15: 3 1100g
2200 g of paraffin wax (mp 70 ° C.)
150 g of charge control agent E-88 (manufactured by Orient Chemical Co., Ltd.)
The above formulation was heated to 60 ° C., and uniformly dissolved and dispersed to prepare a polymerizable monomer composition.
[0060]
The polymerizable monomer composition and the polymerization initiator, 440 g of 2,2′-azobis (2,4-dimethylvaleronitrile), were charged into the aqueous medium. The mixture of the polymerizable monomer composition and the aqueous medium was stirred at 3,700 rpm for 10 minutes using a CLEARMIX stirrer (manufactured by M Technique) in an N ₂ atmosphere at 60 ° C. The product was granulated.
[0061]
Thereafter, the polymerizable monomer composition was transferred to a polymerization apparatus, and the liquid temperature was reacted at 60 ° C. for 5 hours, and then the liquid temperature was 80 ° C. and reacted for 3 hours.
[0062]
After completion of the polymerization reaction, the polymerization solution was transferred to a distillation apparatus, and the distillation was performed for 5 hours at a liquid temperature of 80 ° C.
[0063]
When the distilled suspension was applied to a drum screen having a mesh opening of 2 mm, it was found that the passed product: separated product (= coarse particles) = 99: 1 in terms of the dry mass ratio of the solid content.
[0064]
Hydrochloric acid was added to the distilled suspension that passed through the drum screen to dissolve Ca ₃ (PO ₄ ) ₂ and washed, filtered and dried to obtain dry toner particles. The dry toner particles all had a volume distribution with an arithmetic average particle size of 7.31 μm, 4.0 μm or less 1.11%, 10.1 μm or more 3.66%.
[0065]
The obtained dry toner particles are Elbow Jet Type 5 manufactured by Nittetsu Mining Co., Ltd., all having a volume distribution, arithmetic average diameter of 6.98 μm, 4.0 μm or less, 0.64%, 10.1 μm or more, and 1.02%. Classification into particle size distribution. The mass ratio of the fine particles and coarse particles separated at this time was fine particles: predetermined inner particles: coarse particles = 3: 90: 6.
[0066]
The separated product of the drum screen of the first classifying means and the elbow jet of the second classifying means was added to make fine particles: predetermined internal particles: coarse particles = 3: 90: 7.
[0067]
The coarse particles are pulverized with a turbo mill 250 type manufactured by Turbo Industry Co., Ltd. (rotor peripheral speed 115 m / s, the distance between the rotor and the liner is 1.5 mm, and the pulverization supply amount is 15 kg / H). As a result of classification using an iron mining Co., Ltd. elbow jet type 5, the mass ratio of fine particles to coarse particles was fine particles: predetermined internal particles: coarse particles = 1: 4: 2.
[0068]
Therefore, the final separation ratio was fine particles: predetermined inner particles: coarse particles = 4: 94: 2, and the effective utilization rate of raw materials was 94%.
[0069]
Moreover, the endothermic peak top temperature by DSC measurement was 70 degreeC. Moreover, the amount of residual monomers and by-products (benzaldehyde) was 50 ppm in total.
[0070]
To 100 parts by mass of the obtained toner, 0.7 part by mass of hydrophobic silica having a specific surface area by the BET method of 200 m ² / g was externally added. To 7 parts by mass of this toner, 93 parts by mass of an acrylic-coated ferrite carrier was mixed to obtain a developer. When this developer and externally added toner were used to print out an image using a Canon full color copier CLC-500 remodeling machine, no odor was generated and a good image was obtained.
[0071]
<Reference Example 1>
A toner was prepared and evaluated in the same manner as in Example 1 except that the coarse particles obtained by the first classifying means and the second classifying means were not pulverized / disintegrated.
[0072]
Although there is no problem with the performance of the toner, the separation ratio remains fine particles: predetermined internal particles: coarse particles = 3: 90: 7. Therefore, the effective utilization rate of the raw materials is 90%, which is economical compared to Example 1. The result was inferior.
[0073]
<Example 2>
Without adding up the separation of the drum screen of the first classifying means and the elbow jet of the second classifying means, only the coarse particles of the second classifying means are pulverized by a Japanese pneumatic type I jet mill (pulverization pressure 0.6 kPa). Then, classification was performed again with the second classifying means Elbow Jet Type 5 manufactured by Nittetsu Mining Co., Ltd., and the mass ratio of fine particles to coarse particles was fine particles: predetermined internal particles: coarse particles = 1: 3: 2. It was.
[0074]
Therefore, the final separation ratio was fine particles: predetermined inner particles: coarse particles = 4: 93: 3, and the effective utilization rate of raw materials was 93%.
[0075]
Preparation and evaluation of the toner after reclassification were performed in the same manner as in Example 1, and the toner performance was satisfactory.
[0076]
【The invention's effect】
As described above, according to the present invention, a method for producing a toner having a sharp particle size distribution capable of realizing a high-definition image is provided.
[0077]
Furthermore, according to the present invention, there is provided a method for reusing the predetermined outer particles of the toner excellent in economy.
[Brief description of the drawings]
FIG. 1 is an example of a flow of a toner manufacturing apparatus used in the present invention.

Claims (5)

A method for producing a toner synthesized in an aqueous medium,
And a step of pulverizing or pulverizing coarse particles separated in the classification step to obtain toner particles having a predetermined particle size ,
The toner particles having a predetermined particle size by pulverization or crushing are mixed with toner particles having a predetermined particle size obtained without being separated as coarse particles at a ratio of 1: 100 to 20: 100. the toner manufacturing method according to claim to Rukoto. The toner production method according to claim 1, wherein the classification step is performed by a classifier using a screen. The toner production method according to claim 1, wherein the classification step is performed by a classifier using a Counder effect. Method for producing a toner according to any one of claims 1 to 3, characterized in that a step of the ground or crushed by a jet mill. Method for producing a toner according to any one of claims 1 to 3, characterized in that a step of the ground or crushed by mechanical grinding machine.

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