JP2008040393A - Method for manufacturing polymerized toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new method for manufacturing toner particles and toner having a very sharp particle size distribution, in a method for manufacturing polymerized toner particles and polymerized toner using external circulation type granulation. <P>SOLUTION: At a granulation step, when the preliminary dispersion liquid of a polymerizable monomer composition is transported to an agitator 4 having high shear force, a positive-displacement pump 2 is used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a polymerized toner for developing an electrostatic image, which is used in electrophotography, electrostatic recording method and the like.

  As a method for producing toner particles used in electrophotography, there has been proposed a method for producing polymerized toner particles in which polymerizable monomers are dispersed in the form of droplets and polymerization is performed to directly obtain toner particles. For example, in the method for producing toner particles by suspension polymerization, a polymerizable monomer, a colorant, a release agent, a polymerization initiator, and a cross-linking agent, a charge control agent and other additives are uniformly added as necessary. After dissolving or dispersing to form a polymerizable monomer composition, this is dispersed in an aqueous medium containing a dispersion stabilizer using an appropriate stirrer, and a polymerization reaction is performed to obtain a desired particle size. A suspension of polymerized toner particles having If necessary, the suspension of the polymerized toner particles is treated with an acid or an alkali to remove the dispersion stabilizer, and then the aqueous medium is separated in a solid-liquid separation step to obtain toner particles.

  Polymerized toner particles obtained by such a method have a spherical or nearly spherical shape and a uniform surface. Therefore, the fluidity and transferability are good, and good development characteristics are exhibited even after a number of continuous developments. The stress on the toner particles is low, and the occurrence of filming on the photoreceptor is low. is doing. Further, since the above method does not include a pulverization step, the particle size distribution of the obtained toner particles is sharp, so that almost no loss occurs even if the classification step is performed. However, to further increase productivity, it is necessary to minimize loss due to classification, and a sharper particle size distribution is required.

  As a method for producing a polymerized toner by suspension polymerization, in a granulation process in which a polymerizable monomer composition is dispersed in an aqueous medium, a batch-type stirring tank equipped with a high shear stirrer is used. Often done at. However, in this method, it is necessary to keep good circulation of the whole liquid while applying a shearing force. For this reason, it is difficult to apply an equal shearing force to all the dispersed liquids, and as a result, the particle size distribution of toner particles obtained by polymerizing the liquid becomes wide.

  As one method for solving this problem, the required power of the high shear stirrer can be increased in order to increase the discharge of the stirrer and improve the circulation state of the liquid in the vertical stirring tank. However, in this method, particularly when the scale of the vertical stirring tank is large, the required power of the high shear stirrer becomes remarkably large, which is disadvantageous in terms of apparatus cost. Moreover, as a result of increasing the required power to improve the circulation of the liquid, the shearing force becomes excessive and the particle size distribution may be disturbed.

  As a method of granulating without using a vertical stirring tank equipped with a high shear stirrer as described above, after dispersing the polymerizable monomer composition in an aqueous medium in a normal stirring tank, A part of this dispersion liquid is extracted and returned to the stirring tank after passing through a high shear stirrer provided outside the stirring tank (see, for example, Patent Document 1). However, since the high shear stirrer used in this method is a general in-line type disperser, the uniformity of the shearing force to the dispersion is insufficient, and the sharpness of the particle size of the obtained toner particles is satisfactory. It is not possible.

  In addition, the above-described method requires a pump for transferring the dispersion liquid to a high shear stirrer provided outside, but the pump used at this time is not quantitative, or pulsation may occur even if it is quantitative. In the case of a simple pump, since the amount of liquid processed with a high shear stirrer per hour is not constant, the particle size of the obtained toner becomes broad. Furthermore, even if it is quantitative, since the rotating blades rotate at high speed in a centrifugal pump or the like, a sharp particle size distribution is lost due to excessive shearing force in this portion.

JP 2001-356523 A

  An object of the present invention is to provide a new method for producing a toner having an extremely sharp particle size distribution in a method for producing a polymerized toner including a granulation step of dispersing a polymerizable monomer composition in an aqueous medium. .

As a result of intensive studies to solve the above problems, the present inventors have found the following method.
(1) Agitation means comprising a granulating step of dispersing a polymerizable monomer composition containing at least a colorant and a polymerizable monomer in an aqueous medium to obtain an aqueous medium dispersion of the polymerizable monomer composition; In the method for producing a polymerized toner by circulating between the first container in which the toner is installed and the second container in which the stirring means having a high shearing force is installed, the volume as a means for performing the circulation A method for producing a polymerized toner, comprising using a pump.
(2) The above-described positive displacement pump is a uniaxial eccentric screw pump that transfers an object to be transferred by inserting an externally threaded rotor into an internally threaded stator so as to be rotatable. The method for producing a polymerized toner according to (1).
(3) When the above-described positive displacement pump is kept in non-contact with a small gap around two parallel axes, the two screw rotors mesh with each other and rotate synchronously in opposite directions, (2) The method for producing a polymerized toner according to (1), which is a biaxial screw pump for transporting a transported material.
(4) The method for producing a polymerized toner according to (1), wherein the positive displacement pump is a rotary pump.
(5) The required power of the positive displacement pump is 0.10 kW or more and 0.50 kW or less per 1 m ³ of the flow rate of the aqueous medium dispersion of the polymerizable monomer composition circulating in one hour. The method for producing a polymerized toner according to any one of (1) to (4).
(6) The ratio of the rotational diameter d (m) of the outermost peripheral portion of the stirring means having the high shear force and the inner diameter D (m) of the second container is 0.3 ≦ d / D ≦ 0.8, and The polymerization according to any one of (1) to (5), wherein A represented by the following formula (1) satisfies 200 ≦ A ≦ 1500 and B represented by the following formula (2) satisfies 2000 ≦ B ≦ 20000 Toner manufacturing method.
Formula (1)
A = 5.95 × 10 ⁻³ × ρn ² d ²
(Where ρ (kg / m ³ ) is the density of the aqueous dispersion of the polymerizable monomer composition, n (s ⁻¹ ) is the rotational speed of the stirring means having a high shearing force, and d (m) is high This represents the rotational diameter of the outermost peripheral portion of the stirring means having a shearing force).
Formula (2)
B = 1.19 × 10 ⁻³ × ρtn ³ d ⁵ / V
(Where ρ (kg / m ³ ) is the density of the aqueous dispersion of the polymerizable monomer composition, t (s) is the time for the granulation step, and n (s ⁻¹ ) has a high shearing force. The rotational speed of the stirring means, d (m) represents the rotational diameter of the outermost periphery of the stirring means having a high shearing force, and V (m ³ ) represents the total volume of the aqueous medium dispersion of the polymerizable monomer composition. )

  According to the present invention, a polymerized toner particle including a granulation step of dispersing a polymerizable monomer composition in an aqueous medium and a method for producing the polymerized toner, a new method for producing a polymerized toner having a very sharp particle size distribution. Can be provided.

  The present invention can be suitably used in a suspension polymerization method in which a polymerizable monomer composition is dispersed in an aqueous medium using a mechanical stirring means and then polymerized to obtain polymerized toner particles.

  An example of the apparatus used for the manufacturing method of the present invention is shown in FIG. The polymerizable monomer composition and the aqueous medium are put into a stirring tank denoted by reference numeral 7 in the figure and stirred to obtain a preliminary dispersion of the polymerizable monomer composition. At this time, either the polymerizable monomer composition or the aqueous medium may be prepared in a stirring tank, and the other prepared externally may be added here. The obtained preliminary dispersion is transferred to the tank 1 represented by reference numeral 1. Alternatively, either the polymerizable monomer composition or the aqueous medium can be prepared in a stirring tank, charged into the other prepared in the tank 1, and preliminarily dispersed in the tank 1. While stirring the preliminary dispersion in the tank 1, a part of the preliminary dispersion is extracted by a pump 2, installed in the middle of the extraction line 5, and introduced into the tank 2, 3. The tank 2 is provided with a high-speed stirrer represented by reference numeral 4, and after the preliminary dispersion is granulated into a polymerizable monomer composition dispersion, the tank 1 is fed to the tank 1 through a return line 6. Returned. After granulation for a predetermined time, the polymerizable monomer composition dispersion is transferred to a polymerization tank denoted by reference numeral 8 and polymerized toner particles are obtained by performing a polymerization step while stirring.

  Next, another example of the apparatus used in the manufacturing method of the present invention is shown in FIG. The polymerizable monomer composition and the aqueous medium are put into a stirring tank denoted by reference numeral 17 in the figure and stirred to obtain a preliminary dispersion of the polymerizable monomer composition. At this time, either the polymerizable monomer composition or the aqueous medium may be prepared in a stirring tank, and the other prepared externally may be added here. The obtained preliminary dispersion is transferred to the tank 1 denoted by reference numeral 11. Alternatively, either the polymerizable monomer composition or the aqueous medium can be prepared in a stirring tank, charged into the other prepared in the tank 1, and preliminarily dispersed in the tank 1. While stirring the preliminary dispersion liquid in the tank 1, a part of the preliminary dispersion liquid is continuously extracted by a pump of reference numeral 12 installed in the middle of the extraction line of reference numeral 15 and introduced into the tank 2 of reference numeral 13. The tank 2 is provided with a high-speed stirrer represented by reference numeral 14, and after the preliminary dispersion is granulated into a polymerizable monomer composition dispersion, the tank 1 is supplied to the tank 1 through a return line 16. Returned. After the granulation for a predetermined time, the granulation process is stopped, and the polymerized toner particles are obtained by performing the polymerization process while stirring the obtained polymerizable monomer composition dispersion in the tank 1 as it is.

  Next, another example of the apparatus used in the manufacturing method of the present invention is shown in FIG. The polymerizable monomer composition and the aqueous medium are put into a tank 1 denoted by reference numeral 21 in the figure and stirred to obtain a preliminary dispersion of the polymerizable monomer composition. At this time, either the polymerizable monomer composition or the aqueous medium may be prepared in the tank 1, and the other prepared externally may be charged here. A part of the preliminary dispersion is continuously extracted by a pump denoted by reference numeral 22 installed in the middle of the extraction line denoted by reference numeral 25 and introduced into the tank 2 denoted by reference numeral 23. The tank 2 is provided with a high-speed stirrer represented by reference numeral 24, and the preliminary dispersion liquid is granulated here to become a polymerizable monomer composition dispersion liquid, and then is supplied to the tank 1 through a return line 26. Returned. After granulation for a predetermined time, the polymerizable monomer composition dispersion is transferred to a polymerization tank denoted by reference numeral 27, and polymerized toner particles are obtained by performing a polymerization step while stirring.

  Next, another example of the apparatus used in the production method of the present invention is shown in FIG. The polymerizable monomer composition and the aqueous medium are put into a tank 1 denoted by reference numeral 31 in the drawing and stirred to obtain a preliminary dispersion of the polymerizable monomer composition. At this time, either the polymerizable monomer composition or the aqueous medium may be prepared in the tank 1, and the other prepared externally may be charged here. A part of the preliminary dispersion is continuously extracted by a pump indicated by reference numeral 32 installed in the middle of the extraction line indicated by reference numeral 35 and introduced into the tank 2 indicated by reference numeral 33. The tank 2 is provided with a high-speed stirrer represented by reference numeral 34, and the preliminary dispersion liquid is granulated here to become a polymerizable monomer composition dispersion liquid, and then is supplied to the tank 1 through a return line 36. Returned. After granulating for a predetermined time, a polymerized toner particle is obtained by performing a polymerization step while stirring the polymerizable monomer composition dispersion in the tank 1 as it is.

  Hereinafter, an example using the apparatus shown in FIG. 3 as a manufacturing method of the present invention will be described in detail.

  A polymerizable monomer composition is prepared by mixing / dispersing at least a colorant, and if necessary, a release agent, a charge control agent and other additives in the polymerizable monomer.

  On the other hand, an aqueous medium containing a suspension stabilizer is prepared in the tank 1 represented by reference numeral 21. The above polymerizable monomer composition is put into the tank 1 and stirred to obtain a preliminary dispersion of the polymerizable monomer composition. If the polymerizable monomer composition is dispersed in an aqueous medium in advance before the granulation step, the load on the stirring means having a high shearing force in the granulation step can be reduced, and the particle size can be further sharpened. .

  Next, a part of the preliminary dispersion of the polymerizable monomer composition in the tank 1 is extracted by a pump represented by reference numeral 22 installed in the middle of the extraction line 25 and introduced into the tank 2 denoted by reference numeral 23. The tank 2 is provided with a stirring means having a high shearing force represented by reference numeral 24, and the introduced preliminary dispersion is supplied to the tank 1 through the return line 26 after being subjected to the granulation step. Returned.

  The pumps used to extract liquid from the tank 1 are gear pumps, rotary pumps, screw pumps, and two screw rotors mesh with each other while keeping a small gap around two parallel axes. By rotating synchronously in the opposite direction, the biaxial screw pump that transports the transported object, the male threaded rotor is rotatably inserted into the female threaded stator and rotated eccentrically, thereby transporting the transported object. A positive displacement type pump such as a uniaxial eccentric screw pump is used. These pumps are quantitative, do not cause pulsation like diaphragm pumps and plunger pumps, and have excessive shearing force on the polymerizable monomer composition dispersion like centrifugal pumps such as turbine pumps and volute pumps. Therefore, the particle size distribution of the obtained toner particles can be made extremely sharp. Among them, rotary pumps such as stamp rotary pumps (manufactured by Stamp Pump Co., Ltd.), biaxial screw pumps such as radial screw pumps (manufactured by Futoko Metal Industry), and single-shaft eccentric screw pumps such as MONO pumps (manufactured by Hyojin) Is preferable from the viewpoint of quantitativeness, no pulsation, and no excessive shear force.

The required power of the positive displacement pump is preferably 0.1 kW or more and 0.5 kW or less per 1 m ³ of the flow rate of the polymerizable monomer composition dispersion liquid circulating in one hour. The required power of the pump is almost proportional to the flow rate to be discharged, but under an operating condition in which this is smaller than 0.1 kW, the tank 2 in which the stirring means in which the polymerizable monomer composition dispersion has high shearing force is installed. Since the average number of passes is insufficient, it adversely affects granulation. Also, under the operating conditions where the required power is greater than 0.5 kW, the peripheral speed of the tip of the rotary member of the pump becomes too high, and excessive shear force is exerted on the polymerizable monomer composition dispersion. It adversely affects granulation.

  The linear velocity of the dispersion flowing in the circulation pipe during the granulation step is preferably in the range of 0.1 to 2.5 m / s. If the linear velocity is less than 0.1 m / s, the pipe diameter has to be very large in order to obtain a predetermined flow rate. In this case, depending on the specific gravity of the polymerizable monomer composition, the pipe speed is insufficient in the pipe. Sedimentation may occur, which is not preferable. If the linear velocity is higher than 2.5 m / s, excessive shearing force due to turbulent flow in the pipe may adversely affect the granulation property, and it may cause abnormal vibration of the pipe. It is not preferable.

  Examples of agitation means having a high shearing force used in the granulation process include general edged turbine blades, ultra turrax (manufactured by IKA), T.I. K. A high-speed stirrer such as a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) or Claremix (manufactured by M Technique Co., Ltd.) can be used.

  The ratio of the rotational diameter d (m) of the outermost periphery of the stirring means 24 having the high shearing force and the inner diameter D (m) of the tank 2 is in the range of 0.3 ≦ d / D ≦ 0.8. preferable. When d / D is less than 0.3, the discharge amount by the stirring means becomes small, and the circulation flow rate inside the tank 2 becomes insufficient, resulting in nonuniformity in the shearing history of the dispersion, and the particle size deteriorates. If d / D is larger than 0.8, the distance between the outermost periphery of the stirring means and the inner wall of the tank 2 becomes too close, and an excessive shear force is generated at this portion, which is also not preferable.

Further, A represented by the following formula (1) is preferably in the range of 200 ≦ A ≦ 1500. When A is smaller than 200, a sufficient shearing force cannot be applied to the dispersion, and a sufficiently sharp particle size cannot be obtained. When A is larger than 1500, the shearing force becomes excessive and the particle size is disturbed.
Formula (1)
A = 5.95 × 10 ⁻³ × ρn ² d ²

Here, ρ (kg / m ³ ) is the density of the aqueous medium dispersion of the polymerizable monomer composition, n (s ⁻¹ ) is the rotational speed of the stirring means having a high shear force, and d (m) is the high shear. It represents the rotation diameter of the outermost peripheral part of the stirring means having a force.

Further, B represented by the following formula (2) preferably satisfies 2000 ≦ B ≦ 20000. When B is smaller than 2000, the dropped energy is insufficient, so that a sharp particle size cannot be obtained. Even if B is larger than 20000, sharpness beyond a certain particle size cannot be expected, and it is not preferable because it is necessary to increase the required power unnecessarily or lengthen the granulation time.
Formula (2)
B = 1.19 × 10 ⁻³ × ρtn ³ d ⁵ / V

Here, ρ (kg / m ³ ) is the density of the aqueous medium dispersion of the polymerizable monomer composition, t (s) is the time for performing the granulation step, and n (s ⁻¹ ) is a stirrer having high shearing force The rotational speed of the means, d (m) is the rotational diameter of the outermost periphery of the stirring means having a high shearing force, and V (m ³ ) is the total volume of the aqueous medium dispersion of the polymerizable monomer composition.

  Any stirring blade may be used as the stirring blade used in the tank 1 as long as it can flow the polymerizable monomer composition dispersion liquid without stagnation and keep the temperature in the tank uniform. . For example, paddle wing, inclined paddle wing, three-bladed wing, propeller wing, disk turbine wing, helical ribbon wing, anchor wing, full zone (made by Shinko Pantech), twin star (made by Shinko Pantech), Max Blend ( Sumitomo Heavy Industries, Ltd.), Supermix (Satake Chemical Machinery Co., Ltd.), Hi-F mixer (Soken Chemical Co., Ltd.), etc. can be used.

  Further, regarding the stirring in the tank 1, it is necessary to consider the excessive entrainment of bubbles. If the amount of bubbles involved is excessive, when performing the granulation process, the pump discharge becomes unstable, or if the bubbles reach the tank 2 as they are, the power of the agitator will not be transmitted well. The granulation property is disturbed.

  Moreover, it is preferable that the pressure in the tank 2 at the time of a granulation process is maintained at 0.01 Mpa or more with a gauge pressure. When the pressure in the tank 2 is less than 0.01 MPa, cavitation is likely to occur when stirring is performed by a stirring means having a high shearing force. If cavitation occurs, the energy of stirring is not easily transmitted to the dispersion, and the particle size is not sharp.

  It is preferable that the inside of the tank 2 is filled with the dispersion liquid during the granulation step, and the gas phase portion does not exist. If a gas phase portion exists, a free liquid surface is formed, so that the stirring energy is dissipated here, and as a result, the granulation property is lowered.

  If it is necessary to add a polymerization initiator, it is carried out during the pre-dispersion step or during the granulation step. When added during the preliminary dispersion step, a polymerization initiator is put into the tank 1. When added during the granulation step, it can be introduced into any of the tank 1, the tank 2 and the flow path connecting the two.

  After the granulation step, the polymerizable monomer composition dispersion in the tank 1, the tank 2, the pump and the pipe connecting them is transferred to a polymerization tank represented by reference numeral 27, and the polymerization step is performed. In the polymerization step, stirring is performed while maintaining the polymerizable monomer composition dispersion at a predetermined temperature. A stirring blade similar to that used for the tank 1 can be used for the polymerization tank.

  The polymerization temperature is 40 ° C. or higher, generally 50 to 90 ° C. The polymerization temperature may be constant from beginning to end, but may be raised in the latter half of the polymerization step for the purpose of obtaining a desired molecular weight distribution.

  As the material of each member constituting the apparatus used in the above-described manufacturing apparatus, commonly used materials such as stainless steel, steel, glass, FRP (fiber reinforced plastic), ceramic, and the like can be used. Further, these surfaces may be subjected to treatments such as electrolytic polishing, fluororesin coating, and glass lining.

  In order to remove volatile impurities such as unreacted polymerizable monomers and by-products, a part of the aqueous medium may be distilled off by a distillation step after the completion of the polymerization step. The distillation step can be performed under normal pressure or reduced pressure.

  In order to remove the dispersion stabilizer adhering to the surface of the polymer fine particles, the polymer fine particle dispersion can be treated with an acid or an alkali. Thereafter, the polymer fine particles are separated from the liquid phase by a general solid-liquid separation method, but in order to completely remove the acid or alkali and the dispersion stabilizer dissolved therein, water is added again to remove the polymer fine particles. Wash. This process is repeated several times, and after sufficient washing, solid-liquid separation is performed again to obtain toner particles. The obtained toner particles are dried by a known drying means if necessary.

  The toner obtained by the production method of the present invention may be only the toner particles obtained by the polymerization method described above, or may be a one-component developer obtained by externally adding other additives to the toner particles as necessary. The toner particles and carrier may be mixed to form a two-component developer.

  As the polymerizable monomer suitably used in the present invention, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

Examples of the monofunctional polymerizable monomer include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, and pn-. Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, styrene derivatives such as p-phenylstyrene;
Methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate Acrylic polymerizable monomers such as n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate;
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate Methacrylic polymerizable monomers such as n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate;
Vinyl esters such as methylene aliphatic monocarboxylic acid esters, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate;
Examples include vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

  Examples of the polyfunctional polymerizable monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tripropylene. Glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tri Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethyleneglycol Rudimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4- (methacryloxydiethoxy) phenyl) propane 2,2′-bis (4- (methacryloxypolyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like.

  In the present invention, the above-mentioned monofunctional polymerizable monomers are used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers are combined, Or a polyfunctional polymerizable monomer is used individually or in combination of 2 or more types. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination, or in combination with other monomers from the viewpoints of development characteristics and durability of the toner.

Examples of the colorant used in the present invention include carbon black and iron black,
C. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modern Tread 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modern Blue 7, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes like Basic Green 6,
Yellow lead, Cadmium yellow, Mineral fast yellow, Navel yellow, Naphthol yellow S, Hansa yellow G, Permanent yellow NCG, Tartrazine lake, Molybdenum orange, Permanent orange GTR, Benzidine orange G, Cadmium red, Permanent red 4R, Watching red calcium Salt, Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Bitumen, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green Lake, Final Yellow Green And pigments such as G.

  In selecting a colorant, it is necessary to pay attention to the polymerization inhibitory property and water phase transferability of the colorant. In particular, since dyes and carbon blacks often have polymerization inhibiting properties, care must be taken when using them. These are preferably subjected to surface modification, for example, a hydrophobic treatment with a substance that does not inhibit polymerization. Examples of the method for surface-treating the dye include a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the polymerizable monomer composition. In addition to carbon black, the carbon black may be grafted with a material that reacts with the surface functional groups of the carbon black, such as polyorganosiloxane.

  As the release agent used in the present invention, a wax in a solid state at room temperature may be used in terms of toner blocking resistance, durability of a large number of sheets, low-temperature fixability, and offset resistance.

  As the wax, polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, Fischer-Tropsch wax, linear alkyl alcohol having 15 to 100 carbon atoms, linear fatty acid, linear acid amide, linear And waxes of ester-like esters or montan derivatives and their derivatives such as graft compounds and block compounds. These are preferably removed from the low molecular weight component and have a sharp maximum endothermic peak in the endothermic curve obtained by a differential scanning calorimeter.

  In order to improve the translucency of the image fixed on the OHP, a linear ester wax is particularly preferably used.

  The linear ester wax is preferably contained in an amount of 1 to 40 parts by mass, more preferably 4 to 30 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  The toner produced according to the present invention may contain a charge control agent. Known charge control agents can be used. The charge control agent can be externally added to the toner particles, but can also be added inside the toner particles by dispersion in the polymerizable monomer composition or the like.

  For example, organometallic compounds and chelate compounds are effective for controlling the toner to be negatively charged, and monoazo dye metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metals Examples thereof include salts, anhydrides, esters, and phenol derivatives such as bisphenol. Examples of toners that are negatively charged include urea derivatives, metal-containing salicylic acid compounds, quaternary ammonium salts, calixarene, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, Examples include styrene-acrylic-sulfonic acid copolymers and non-metallic carboxylic acid compounds.

  Examples of toners that are controlled to be positively charged include denatured products of nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, And onium salts such as phosphonium salts thereof and their lake pigments, triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid) , Lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids, diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide, dibutyltin borate, dioctyl Rusuzuboreto, there is diorgano tin borate, and the like, such as dicyclohexyl tin borate, may be used alone or in combination of two or more. Among these, a charge control agent such as a nigrosine-based quaternary ammonium salt is particularly preferably used.

  These charge control agents are preferably used in an amount of 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  In order to polymerize the polymerizable monomer, a polymerization initiator can be used. Examples of the polymerization initiator that can be used in the present invention include azo polymerization initiators. As the azo polymerization initiator, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) ), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobismethylbutyronitrile, and the like.

  An organic peroxide initiator can also be used. Organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, bis (4-t-butyl) (Cyclohexyl) peroxydicarbonate, 1,1-bis (t-butylperoxy) cyclododecane, t-butylperoxymaleic acid, bis (t-butylperoxy) isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy Examples include 2-ethylhexanoate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and the like.

  A redox initiator in which an oxidizing substance and a reducing substance are combined can also be used. Examples of the oxidizing substance include inorganic peroxides such as hydrogen peroxide and persulfates (sodium salts, potassium salts, ammonium salts, etc.), and oxidizing metal salts such as tetravalent cerium salts. Reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, trivalent chromium salts, etc.), ammonia, lower amines (amines having about 1 to 6 carbon atoms such as methylamine and ethylamine). , Amino compounds such as hydroxylamine, sodium thiosulfate, sodium hydrosulfite, sodium hydrogen sulfite, sodium sulfite, sodium formaldehyde sulfoxylate and other reducing sulfur compounds, lower alcohols (about 1 to 6 carbon atoms), ascorbic acid or Examples thereof include salts and lower aldehydes (about 1 to 6 carbon atoms).

  The polymerization initiator is selected with reference to a 10-hour half-life temperature, and is used alone or in combination. Although the addition amount of the said polymerization initiator changes with the target degree of polymerization, generally 0.5-20 mass parts is added with respect to 100 mass parts of polymerizable monomers.

  In the present invention, for example, when a polymerizable monomer is polymerized, various crosslinking agents can be used. Examples of the crosslinking agent include divinylbenzene, 4,4′-divinylbiphenyl, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycidyl (meth) acrylate, and trimethylolpropane tri (meth) acrylate. Examples include functional compounds.

  As the dispersion medium, which is a continuous phase when the polymerizable monomer composition is dispersed, known ones used in various polymerization methods can be used, and the dispersion medium is appropriately determined depending on the polymerizable monomer or polymerization method used. It is selected and is not particularly limited. In suspension polymerization, an aqueous medium is used. The aqueous medium is a medium mainly composed of water or water containing a water-soluble component such as a water-soluble organic solvent or a water-soluble inorganic salt, and the polymerizable monomer composition is dispersed as droplets. If it does not specifically limit.

  As the dispersion stabilizer for satisfactorily dispersing the polymerizable monomer composition in the aqueous medium, any of inorganic compounds and organic compounds can be used. Examples of inorganic compounds include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, and barium sulfate. , Bentonite, silica, alumina, titania, hydroxyapatite and the like. Examples of the organic compound include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like. It is preferable that 0.2-10.0 mass parts is used for a dispersion stabilizer with respect to 100 mass parts of polymerizable monomers.

  As the dispersion stabilizer, a commercially available one may be used as it is, but when the above inorganic compound is used, in order to obtain dispersed particles having a fine uniform particle size, the inorganic compound is generated under stirring in a dispersion medium. You can also For example, in the case of tricalcium phosphate, a dispersion stabilizer suitable for suspension polymerization can be obtained by charging and mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution with sufficient stirring.

  In the case of a polymerization method using an aqueous medium such as suspension polymerization, the inclusion of a release agent can be promoted by adding a polar resin to the polymerizable monomer composition. When a polar resin is present in a polymerizable monomer composition suspended in an aqueous medium, the polar resin moves to the vicinity of the interface between the aqueous medium and the polymerizable monomer composition due to the difference in affinity for water. Therefore, the polar resin is unevenly distributed on the surface of the toner particles. As a result, the toner particles have a core-shell structure, and the inclusion property of the release agent is improved even when a large amount of the release agent is contained.

  In addition, if a resin with a high melting temperature is selected as the polar resin used for the shell, even if the binder resin is designed to be melted at a lower temperature for the purpose of fixing at low temperature, it may cause problems such as blocking during storage. Can be suppressed.

  As such a polar resin, since the fluidity of the polar resin itself can be expected when the shell is formed unevenly distributed on the surface of the toner particles, a saturated or unsaturated polyester resin is particularly preferable.

  As said polyester-type resin, what carried out the condensation polymerization of the acid component monomer and alcohol component monomer which are mentioned below can be used. Acid monomers include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, camphor An acid, cyclohexane dicarboxylic acid, trimellitic acid, etc. are mentioned.

Examples of the alcohol component monomer include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxy Methyl) cyclohexane and other alkylene glycols and polyalkylene glycols, bisphenol A, hydrogenated bisphenol,
Examples include bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin, trimethylolpropane, and pentaerythritol.

In the production method of the present invention, an external additive can be used for the purpose of imparting various properties to the toner. The external additive preferably has a particle size of 1/10 or less of the average particle size of the toner particles from the viewpoint of durability when added to the toner. Examples of the external additive include metal oxides such as aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, and zinc oxide,
Nitrides such as silicon nitride, carbides such as silicon carbide, inorganic metal salts such as calcium sulfate, barium sulfate and calcium carbonate, fatty acid metal salts such as zinc stearate and calcium stearate, carbon black, silica and the like are used.

  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. The external additives may be used alone or in combination of two or more, but it is more preferable to use a hydrophobized one.

  Furthermore, the production method of the present invention can also be applied to a production method of a magnetic toner containing a magnetic material. In this case, the magnetic material contained in the toner particles can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, hematite and ferrite, metals such as iron, cobalt and nickel, and these metals and aluminum, cobalt, copper, lead, magnesium and tin. , Zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium metal alloys, and mixtures thereof.

  These magnetic materials have an average particle diameter of 2 μm or less, preferably about 0.1 to 0.5 μm. The content of the magnetic material in the toner particles is about 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight with respect to 100 parts by weight of the polymerizable monomer. Is good.

The magnetic material has a coercive force (Hc) of 1.6 to 24 kA / m, a saturation magnetization (σs) of 50 to 200 Am ² / kg, and a residual magnetization (σr) of 800 kA / m. It is preferable that it is 2-20 Am < ² > / kg. These magnetic properties can be measured using a vibration type magnetometer, for example, VSM P-1-10 (manufactured by Toei Kogyo Co., Ltd.) under conditions of, for example, 25 ° C. and an external magnetic field of 800 kA / m.

  In order to improve the dispersibility of these magnetic materials in the toner particles, it is also preferable to subject the surface of the magnetic material to a hydrophobic treatment. For the hydrophobization treatment, coupling agents such as a silane coupling agent and a titanium coupling agent are used, and among them, a silane coupling agent is preferably used. As silane coupling agents, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, Examples include dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

  As described above, the toner produced according to the present invention can be used for either a one-component developer or a two-component developer. The toner produced in the present invention is used for image formation by an appropriate method according to the type. For example, in the case of a magnetic toner containing a magnetic material in a toner particle as a one-component developer, the magnetic toner is conveyed using a magnet built in the developing sleeve when an image is formed using the magnetic toner. A method of charging is used. When non-magnetic toner containing no magnetic material is used, during image formation using this non-magnetic toner, for example, a blade and a fur brush are used to forcibly frictionally charge the developing sleeve, and the toner is placed on the sleeve. The method of conveying by attaching is used.

  On the other hand, when the toner obtained by the production method of the present invention is used as a commonly used two-component developer, it is used as a developer using a carrier together with the toner. The carrier used in the present invention is not particularly limited, but particles containing single or composite ferrite mainly composed of iron, copper, zinc, nickel, cobalt, manganese and chromium elements are used.

  The carrier shape is also important because the saturation magnetization and electric resistance can be controlled over a wide range. For example, it is preferable to select the shape of the carrier from spherical, flat, indeterminate, etc., and to control the fine structure of the surface of the carrier, for example, the surface irregularity.

  As the carrier, generally, a resin-coated carrier obtained by firing and granulating the above metal compound to produce carrier core particles and coating the resin thereon. From the viewpoint of reducing the load on the toner of the carrier, a low-density dispersion carrier obtained by kneading a magnetic material and a resin, then pulverizing and classifying, or a kneaded product of a metal compound and a monomer directly in an aqueous medium. Polymer carriers obtained by suspension polymerization and dispersion in a true sphere can also be used as the carrier. The carrier core particles can be used for the carrier.

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

  When the two-component developer is prepared, the mixing ratio of the carrier and the toner produced in the present invention is usually 2-15% by mass, preferably 4-13% by mass as the toner concentration in the developer. Is obtained. When the toner concentration is less than 2% by mass, the image density is low and practical use is difficult. When the toner concentration exceeds 15% by mass, fogging and scattering in the apparatus increase, and image deterioration and developer consumption may occur.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited at all by these. In the examples, the following method was used to measure the particle size distribution of the toner.

(1) Measurement of volume average particle diameter of toner particles 0.1 to 5 ml of alkylbenzene sulfonate as a surfactant is added to 100 to 150 ml of 1% by mass sodium chloride aqueous solution. Further, 0.5 to 50 mg of a measurement sample was added, and this sample dispersion was dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the number of toner particles was measured with a Coulter Multisizer (manufactured by Coulter) using a 100 μm aperture. Standard and volume-based particle size distributions were measured. The number variation coefficient was obtained from the number average diameter and number standard deviation obtained by Coulter Multisizer by the following formula, and used as an index of the sharpness of the particle size distribution. Here, the smaller the value of the number variation coefficient, the sharper the particle size distribution.
Number variation coefficient (%) = number standard deviation ÷ number average diameter × 100

(2) Image quality evaluation To 100 parts by mass of toner particles, a hydrophobic silica fine powder having a specific surface area measured by the BET method of 300 m ² / g is externally added to 1.5 parts by mass, and one-component development is performed. An agent was obtained. The developer was subjected to an image printing endurance test by continuous paper passing under a non-fluctuating environment using a Canon laser printer LBP-2160, and image density fluctuation, image unevenness, and the like were visually evaluated.

In addition, the reflectance of plain paper before printing and the reflectance of a solid white image were measured with a reflectometer (TC-6DS manufactured by Tokyo Denshoku Co., Ltd.), and the fog (%) was calculated by the following formula. did.
Fog (%) = reflectance of plain paper-reflectance of solid white image

The obtained fog value was evaluated in five steps according to the following evaluation criteria.
A: Very good level (less than 0.5%)
B: Good level (0.5% or more and less than 1.0%)
C: No problem level (1.0% or more and less than 2.0%)
D: Acceptable level (2.0% or more and less than 3.0%)
E: Bad level (3.5% or more)

<Example 1>
Using the apparatus having the configuration illustrated in FIG. 3, toner particles were produced by the following procedure.

(Preparation of colorant dispersion)
Styrene 50.0 parts by mass Salicylic acid compound aluminum complex (Bontron E-88 manufactured by Orient Chemical Industries)
0.95 parts by mass Carbon black 10.0 parts by mass The above components were charged into a temperature-controllable stirring tank and stirred sufficiently to blend in, and then an SC mill (Mitsui Mining Co., Ltd.) was incorporated in the middle. A colorant dispersion was prepared by circulating 90 minutes in the circulation line using a pump. Zirconia beads having a diameter of 0.5 mm were used for the SC mill, and the rotor peripheral speed in the SC mill was 10.0 m / s.

(Preparation of polymerizable monomer composition)
Styrene 33.0 parts by weight Colorant dispersion 60.95 parts by weight n-butyl acrylate 17.0 parts by weight Terephthalic acid-propylene oxide modified bisphenol A polymer (average molecular weight: 7500, acid value: 10 mg KOH / g) 0 parts by mass behenyl behenate (melting point: 73 ° C.) 13.75 parts by mass Among the above components, other than behenyl behenate was put into a temperature-controllable stirring tank and stirred and mixed at room temperature. After raising the temperature to 0 ° C., behenyl behenate was charged into the stirring tank, and stirring was continued to obtain a polymerizable monomer composition.

(Preparation of aqueous medium)
Water 97.8 parts by mass Trisodium phosphate 1.4 parts by mass The above components were put into a temperature-adjustable stirring tank (tank 1) equipped with a full zone blade (manufactured by Shinko Pantech Co., Ltd.), and the temperature was raised to 60 ° C. After that, the mixture was stirred at a low speed until the trisodium phosphate was completely dissolved. Next, an aqueous solution in which 0.8 part by mass of calcium chloride was dissolved in water was added, and the mixture was stirred for 30 minutes at a rotation speed of 170 rotations / minute to obtain an aqueous medium that was an aqueous suspension of hydroxyapatite fine particles.

(Preparation of polymerization initiator solution)
2.3 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 9.2 parts by mass of styrene are stirred and mixed with respect to 100 parts by mass of the polymerizable monomer composition, and polymerization is performed. An initiator solution was prepared.

(Preliminary dispersion process)
The aqueous medium in the tank 1 described above is kept at 60 ° C., and the polymerizable monomer composition at 60 ° C. is also contained therein so that the mass ratio of the aqueous medium and the polymerizable monomer composition is 2: 1. The mixture was stirred and stirred with a full zone blade to prepare a preliminary dispersion of the polymerizable monomer composition. Next, the polymerization initiator solution was added to the polymerizable monomer composition so as to have a mass ratio of 0.115, and further stirred.

(Granulation process)
A part of the pre-dispersion liquid of the polymerizable monomer composition in the tank 1 is extracted from the extraction line opened at the bottom of the tank 1 using a rotary pump, and equipped with CLEARMIX 7.5S (manufactured by M Technique). Was introduced into the tank 2 at a flow rate of 0.001 m ³ / s. The ratio d / D between the rotor diameter of the Clairemix and the inner diameter of the tank 2 was 0.38. The preliminary dispersion liquid introduced into the tank 2 is granulated by a CLEARMIX rotating at 117 s ⁻¹ and then returns to the tank 1 through a return line. By carrying out such circulation for 450 seconds, a polymerizable monomer composition dispersion was obtained. At this time, the required power per 1 m ³ flow rate of the aqueous dispersion of the polymerizable monomer composition circulating in one hour of the pump was 0.28 kW, A was 287, and B was 2723.

(Polymerization process)
The above-mentioned polymerizable monomer composition dispersion is transferred to a polymerization tank, and while stirring with a full zone blade, the liquid temperature is kept at 60 ° C. for 5 hours, and then the liquid temperature is raised to 80 ° C. The polymerization process was further continued for 4 hours to obtain a polymer fine particle dispersion.

(Washing / Solid-liquid separation / Drying process)
Hydrochloric acid was added to the obtained polymer fine particle dispersion and stirred to dissolve the hydroxyapatite covering the polymer fine particles, and then solid-liquid separation was performed using a known filter such as a pressure filter, a filter press, or a belt filter. As a result, polymer fine particles were obtained. This was put into water and stirred to obtain a dispersion again, followed by solid-liquid separation with the above-mentioned filter. After redispersion of polymer fine particles in water and solid-liquid separation are repeated until the hydroxyapatite is sufficiently removed, the final solid-liquid separation of the polymer fine particles is performed using a fluidized bed dryer or airflow drying. The toner particles were sufficiently dried by a known drying means such as a machine. When the particle size distribution of the obtained toner particles was measured, the volume average particle size was 6.9 μm, the number variation coefficient was 22.2%, and the particle size distribution was very sharp, and almost no classification step was required. .

(Evaluation of toner image quality)
The obtained toner particles were externally added with the hydrophobic silica fine powder to obtain a toner (one-component developer). Using this toner, continuous 20000 printing was performed to evaluate the image quality. The image density did not vary and the image was not uneven, and a clear image was stably obtained. The fog evaluation was A.

<Example 2>
Except that a part of the predispersed dispersion of the polymerizable monomer composition in the tank 1 was extracted from the extraction line opened at the bottom of the tank 1 during the granulation process, a biaxial screw pump was used. In the same manner, toner particles were produced. At this time, the required power per 1 m ³ of the flow rate of the aqueous medium dispersion liquid of the polymerizable monomer composition circulating in one hour of the pump was 0.31 kW. The obtained toner particles had a volume average particle size of 6.8 μm and a number variation coefficient of 22.1%, which was a very sharp particle size distribution as in Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog evaluation was A.

<Example 3>
Except for using a uniaxial eccentric screw pump when extracting a part of the predispersed dispersion of the polymerizable monomer composition in the tank 1 from the extraction line opened at the bottom of the tank 1 during the granulation step, exactly the same as in Example 1. In the same manner, toner particles were produced. At this time, the required power per 1 m ³ of the flow rate of the aqueous medium dispersion liquid of the polymerizable monomer composition circulating in one hour of the pump was 0.35 kW. The obtained toner particles had a volume average particle size of 6.7 μm and a number variation coefficient of 22.3%, which was an extremely sharp particle size distribution as in Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog evaluation was A.

<Example 4>
The toner particles were produced in the same manner as in Example 1 except that the rotation speed of the CLEARMIX during the granulation step was 95 s ^-1 and the granulation time was 630 seconds, so that A was 189 and B was 2041. went. The obtained toner particles had a volume average particle diameter of 7.2 μm and a number variation coefficient of 22.8%, which was a sharp particle size distribution almost the same as in Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as B.

<Example 5>
Production of toner particles in exactly the same manner as in Example 1 except that the number of revolutions of the CLEARMIX during the granulation step was 270 s ^-1 and the granulation time was 260 seconds, so that A was set to 1530 and B was set to 19336. Went. The obtained toner particles have a volume average particle size of 7.5 μm and a number variation coefficient of 23.2%, which is generally sharp, but the particle size distribution is slightly more coarse than that of Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as C.

<Example 6>
Toner particles were produced in the same manner as in Example 1 except that the granulation time was 300 seconds, and A was 287 and B was 1816. The obtained toner particles had a volume average particle size of 7.0 μm and a number variation coefficient of 22.8%, which was a sharp particle size distribution similar to that in Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as B.

<Example 7>
By changing the rotor diameter of the CLEARMIX during the granulation step to set d / D to 0.57, the rotation speed to 100 s ⁻¹ , and the granulation time to 900 seconds, A was set to 472 and B was set to 25824. Other than that, toner particles were produced in the same manner as in Example 1. The obtained toner particles had a volume average particle size of 7.2 μm and a number variation coefficient of 23.5%, which was a relatively sharp particle size distribution. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as C.

<Example 8>
Except that the required power per 1 m ³ of the flow rate of the aqueous dispersion of the polymerizable monomer composition circulating through the pump for 1 hour is 0.08 kW and the flow rate is 0.0003 m ³ / s. Toner particles were produced in the same manner as in Example 1. The obtained toner particles had a volume average particle diameter of 7.5 μm and a number variation coefficient of 23.1%, which was a slightly broader particle size distribution than that of Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as C.

<Example 9>
Except that the required power per 1 m ³ of the flow rate of the aqueous dispersion of the polymerizable monomer composition circulating through the pump for 1 hour is 0.7 kW and the flow rate is 0.002 m ³ / s. Toner particles were produced in the same manner as in Example 1. The obtained toner particles had a volume average particle size of 7.3 μm and a number variation coefficient of 22.9%, which was a slightly broader particle size distribution than that of Example 1. When the toner particles were externally added to the toner particles in the same manner as in Example 1 and the image quality was evaluated, there was no fluctuation in the image density and there was no unevenness in the image, and a clear image was stably obtained. The fog was evaluated as B.

<Comparative Example 1>
Example 1 except that a centrifugal turbine pump was used when a part of the preliminary dispersion of the polymerizable monomer composition in the tank 1 was extracted from the extraction line opened at the bottom of the tank 1 during the granulation step. Toner particles were produced in exactly the same manner. At this time, the required power per 1 m ³ of the flow rate of the aqueous medium dispersion liquid of the polymerizable monomer composition circulating in one hour of the pump was 0.21 kW. The obtained toner particles had a volume average particle diameter of 7.8 μm and a number variation coefficient of 24.8%, which is a broad particle size distribution as compared with Example 1. When the toner particles were externally added in the same manner as in Example 1 and the image quality was evaluated, white streaks and density unevenness were observed from a relatively early stage. The fog evaluation was E.

  Table 1 summarizes the results for comparison.

It is the schematic which shows an example of the apparatus used for the manufacturing method of the polymerization toner particle of this invention. It is the schematic which shows another example of the apparatus used for the manufacturing method of the polymerization toner particle of this invention. It is the schematic which shows another example of the apparatus used for the manufacturing method of the polymerization toner particle of this invention. It is the schematic which shows another example of the apparatus used for the manufacturing method of the polymerization toner particle of this invention.

Explanation of symbols

1 Tank 1
2 Pump 3 Tank 2
4 High-speed stirrer 5 Extraction line 6 Return line 7 Stirring tank 8 Polymerization tank 11 Tank 1
12 Pump 13 Tank 2
14 High-speed stirrer 15 Extraction line 16 Return line 17 Stirring tank 21 Tank 1
22 Pump 23 Tank 2
24 High-speed stirrer 25 Extraction line 26 Return line 27 Polymerization tank 31 Tank 1
32 Pump 33 Tank 2
34 High-speed agitator 35 Extraction line 36 Return line

Claims (6)

A stirring means is provided for the granulation step in which a polymerizable monomer composition containing at least a colorant and a polymerizable monomer is dispersed in an aqueous medium to obtain an aqueous medium dispersion of the polymerizable monomer composition. In the method for producing a polymerized toner, which is performed by circulating between the first container and the second container in which the stirring means having a high shear force is installed,
A method for producing a polymerized toner, wherein a positive displacement pump is used as a means for circulating and circulating.   2. The above-described positive displacement pump is a uniaxial eccentric screw pump for transferring a transfer object by inserting a male screw type rotor into a female screw type stator so as to be rotatable and rotating eccentrically. A method for producing the polymerized toner described in 1.   The above-mentioned positive displacement pump keeps non-contact with a small gap around two parallel axes, and the two screw rotors mesh with each other and rotate synchronously in opposite directions. The method for producing a polymerized toner according to claim 1, wherein the method is a biaxial screw pump that transfers the polymer toner.   The method for producing polymerized toner according to claim 1, wherein the positive displacement pump is a rotary pump. The required power of the positive displacement pump is 0.10 kW or more and 0.50 kW or less per 1 m ³ of the flow rate of the aqueous medium dispersion of the polymerizable monomer composition circulating in one hour. Item 5. A method for producing a polymerized toner according to any one of Items 1 to 4. The ratio of the rotational diameter d (m) of the outermost peripheral portion of the stirring means having the high shear force described above to the inner diameter D (m) of the second container is 0.3 ≦ d / D ≦ 0.8, and the following (1 6. The method for producing a polymerized toner according to claim 1, wherein A represented by the formula satisfies 200 ≦ A ≦ 1500, and B represented by the following formula (2) satisfies 2000 ≦ B ≦ 20000.
Formula (1)
A = 5.95 × 10 ⁻³ × ρn ² d ²
(Where ρ (kg / m ³ ) is the density of the aqueous dispersion of the polymerizable monomer composition, n (s ⁻¹ ) is the rotational speed of the stirring means having a high shearing force, and d (m) is high (Represents the rotational diameter of the outermost periphery of the stirring means having a shearing force.)
Formula (2)
B = 1.19 × 10 ⁻³ × ρtn ³ d ⁵ / V
(Where ρ (kg / m ³ ) is the density of the aqueous dispersion of the polymerizable monomer composition, t (s) is the time for the granulation step, and n (s ⁻¹ ) has a high shearing force. The rotational speed of the stirring means, d (m) represents the rotational diameter of the outermost periphery of the stirring means having a high shearing force, and V (m ³ ) represents the total volume of the aqueous medium dispersion of the polymerizable monomer composition. )

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