Method for manufacturing toner particles

Abstract

To provide a manufacturing method that prevents fusion in a step of drying wet toner particles.SOLUTION: A loop-type airflow dryer 4 supplies wet toner particles to an airflow circulating in a loop-type drying tube to dry the particles. The dryer is provided with (i) a loop-type drying tube 8, (ii) a charging port 7 for supplying the wet particles to the drying tube, (iii) a discharge port 13 for discharging the dried particles from the drying tube, (iv) a first blow-in port 10 for blowing in air to the drying tube, and (v) a second blow-in port 12 for blowing in air to the drying tube. The first blow-in port is located on the upstream side of the second blow-in port. When the velocity of air and the volume of air from the first blow-in port are defined as A(m / s) and C(m3 / s), respectively, and the velocity of air and the volume of air from the second blow-in port as B(m / s) and D(m3 / s), respectively, A, B, C, and D satisfy the formulas (1) to (3), and the temperature of the airflow is 60 to 80°C. (1) 4.5≤A≤14.5; (2) 19.0≤B≤38.5; (3) 0.20≤C / (C+D)≤0.60.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing toner particles used in image formation by an electrophotographic method.

Background Art

[0002] In recent years, image forming apparatuses such as copiers and laser beam printers have been required to use toners that melt at lower temperatures in order to respond to energy saving and higher printing speeds. In response to such demands, wet toners that produce toner particles in an aqueous medium are widely used because they are advantageous for introducing a large amount of a release agent or a crystalline resin and because it is easy to control the toner shape. As wet production methods, proposals have been made for toners of wet production methods such as a suspension polymerization method using a polymerizable monomer or the like, an emulsion polymerization aggregation method, and a dissolution suspension method for granulating a binder resin or the like in a solvent. Generally, in these wet production methods, a filtration step of separating a toner particle slurry into solid and liquid to obtain wet toner particles during the production process, and a drying step of drying the wet toner particles by various methods after the filtration step to remove the dispersion medium are performed to obtain toner particles. In the drying step, it is common to use a heat medium to remove the dispersion medium, and an airflow dryer that uses a gas as the heat medium is widely used from the viewpoint of productivity. Among airflow dryers, a loop-type airflow dryer is preferably used because dried toner particles are appropriately discharged from a drying tube, so that the time of being exposed to the drying gas after drying is shorter than that of other airflow dryers and excessive heat is hardly applied, and thus the quality can be kept constant (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the drying gas blown into the loop-type airflow dryer described above uses a high velocity to break down, transport, and dry the wet toner particles. As a result, there are localized areas of high velocity within the drying tube, and toner particles collide with the inside of the pipe. Furthermore, the more easily the toner image is fixed at low temperatures, such as by lowering the glass transition temperature of the toner particles, the greater the problem of fusion adhesion to the inside of the pipe due to these collisions. On the other hand, if the rate of the dry gas is reduced to mitigate these problems, the amount of heat required for drying becomes insufficient, reducing the drying efficiency. The present invention aims to provide a method for manufacturing toner particles that solves the above-mentioned problems. Specifically, the present invention provides a manufacturing method that suppresses fusion that occurs when wet toner particles collide with the inside of a drying tube, without reducing the drying efficiency of the workpiece during the drying process of wet toner particles manufactured by a wet process. [Means for solving the problem]

[0005] The present invention is a method for producing toner particles, comprising the step of drying wet toner particles, which are generated in an aqueous dispersion medium, by a drying means. The drying means is a loop-type airflow dryer that supplies the wet toner particles to an airflow circulating through a loop-type drying tube and dries them, and the loop-type airflow dryer is (i) Loop-type drying tube and (ii) an inlet for supplying the wet toner particles to the drying tube and (iii) an outlet for discharging dried toner particles from the drying tube and (iv) A first inlet for blowing gas into the drying tube and (v) A second inlet for blowing gas into the drying tube and It is equipped with, The first inlet is located upstream of the second inlet in relation to the transport path of the wet toner particles. Let A (m / s) be the air velocity of the gas supplied from the first inlet, B (m / s) be the air velocity of the gas supplied from the second inlet, and C (m) be the air volume of the gas supplied from the first inlet.3 Let D(m) be the airflow rate of the gas supplied from the second inlet (m / s). 3 The present invention relates to a method for producing toner particles, characterized in that, when the temperature is set to / s, A, B, C, and D satisfy the following formulas (1), (2), and (3), and the temperature of the airflow supplied from the first and second inlet is 60°C or higher and 80°C or lower. 4.5 ≤ A ≤ 14.5 (1) 19.0 ≤ B ≤ 38.5 (2) 0.20 ≤ C / (C + D) ≤ 0.60 (3) [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a method for producing toner particles that suppresses fusion adhesion that occurs when wet toner particles collide with the inside of a drying tube, without reducing the drying efficiency of the workpiece. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of a drying system including a loop-type airflow dryer applicable to the present invention. [Figure 2] This is a schematic diagram of a drying system including a loop-type airflow dryer applicable to the present invention. [Figure 3] This is an explanatory diagram of the input port and the transport path for wet toner particles in a loop-type airflow dryer. [Modes for carrying out the invention]

[0008] The embodiments for carrying out the present invention will be described in detail below.

[0009] The present invention relates to a method for producing toner particles having a step of drying wet toner particles obtained by generation in an aqueous dispersion medium by a drying means, wherein the drying means is a loop-type air current dryer that supplies the wet toner particles to an air current circulating in a loop-type drying pipe and dries them, and the loop-type air current dryer comprises: (i) a loop-type drying pipe; (ii) an inlet for supplying the wet toner to the drying pipe; (iii) an outlet for discharging the dried toner particles from the drying pipe; (iv) a first blowing port for blowing gas into the drying pipe; and (v) a second blowing port for blowing gas into the drying pipe, and the first blowing port is located upstream of the second blowing port with respect to the conveyance path of the wet toner particles.

[0010] And, when the wind speed of the gas supplied from the first blowing port is A (m / s), the wind speed of the gas supplied from the second blowing port is B (m / s), the air volume of the gas supplied from the first blowing port is C (m 3 / s), and the air volume of the gas supplied from the second blowing port is D (m 3 / s), A, B, C, and D satisfy the following formulas (1), (2), and (3) 4.5 ≦ A ≦ 14.5 (1) 19.0 ≦ B ≦ 38.5 (2) 0.20 ≦ C / (C + D) ≦ 0.60 (3) and the temperature of the air currents supplied from the first blowing port and the second blowing port is 60°C or higher and 80°C or lower.

[0011] The method for producing toner particles of the present invention having the above configuration includes a drying step of removing a dispersion medium and a cleaning liquid used in a cleaning step from wet toner particles containing a binder resin, a colorant, a release agent, etc., and drying the wet toner particles. The method for producing toner particles of the present invention can be used in a dissolution suspension method, an emulsion aggregation method, a suspension polymerization method, and other wet methods for producing toner particles.

[0012] Hereinafter, as an example, the case where the present invention is used in a method for producing toner particles by a suspension polymerization method will be described.

[0013] The suspension polymerization method is a production method in which a polymerizable monomer composition containing a polymerizable monomer and a colorant is granulated in an aqueous medium to form particles of the polymerizable monomer composition, and the polymerizable monomer contained in the particles of the polymerizable monomer composition is polymerized to obtain toner particles.

[0014] Specifically, it includes a step of preparing a polymerizable monomer composition, a granulation step, a polymerization step, a step of removing organic volatile components, a washing step, a solid-liquid separation step, a drying step, and a classification step.

[0015] Hereinafter, when the present invention is used in the method for producing toner particles by the suspension polymerization method, it will be described step by step.

[0016] (Step of preparing polymerizable monomer composition) A polymerizable monomer composition containing a polymerizable monomer and a colorant is prepared. The colorant may be dispersed in the polymerizable monomer in advance using a medium stirring mill or the like and then mixed with other compositions, or may be dispersed after all the compositions are mixed.

[0017] (Granulation step) The polymerizable monomer composition is put into an aqueous medium containing an inorganic dispersion stabilizer and dispersed to granulate, and a dispersion of the polymerizable monomer composition is obtained by forming particles of the polymerizable monomer composition in the aqueous medium. The granulation step can be carried out, for example, in a vertical stirring tank equipped with a stirrer having a high shearing force. The stirrer having a high shearing force is not particularly limited, and for example, commercially available ones such as the following can be used. High Shear Mixer (manufactured by IKA), T.K. Homomixer (manufactured by Primix Corporation), T.K. Filmixer (manufactured by Primix Corporation), Clear mixer (manufactured by M. Technique Co., Ltd.).

[0018] Examples of inorganic dispersion stabilizers include: carbonates such as barium carbonate, calcium carbonate, and magnesium carbonate; metal phosphates such as aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, and zinc phosphate; sulfates such as barium sulfate and calcium sulfate; and metal hydroxides such as calcium hydroxide, aluminum hydroxide, magnesium hydroxide, and ferric hydroxide. These can be used individually or in combination of two or more. They exert their function as dispersion stabilizers by existing as fine particles in an aqueous medium.

[0019] (Polymerization process) A dispersion of toner particles is obtained by introducing the dispersion of the polymerizable monomer composition obtained as described above into the polymerization process. A general-purpose stirring tank with temperature control can be used for the polymerization process in this invention.

[0020] The polymerization temperature is 40°C or higher, generally 50-90°C. The polymerization temperature may be kept constant throughout the process, but it may be increased in the latter half of the polymerization process to obtain a desired molecular weight distribution. Any type of stirring blade can be used for stirring, as long as it can keep the dispersion of toner raw materials suspended without stagnation and maintain a uniform temperature in the tank. Examples of stirring blades or stirring means include: general stirring blades such as paddle blades, inclined paddle blades, three-blade swept blades, propeller blades, disk turbine blades, helical ribbon blades and anchor blades, as well as "Fullzone" (manufactured by Kobe Steel Environmental Solutions Co., Ltd.), "Twinstar" (manufactured by Kobe Steel Environmental Solutions Co., Ltd.), "Maxblend" (manufactured by Sumitomo Heavy Industries, Ltd.), "Supermix" (manufactured by Satake Chemical Machinery Industry Co., Ltd.) and "Hi-F Mixer" (manufactured by Soken Chemical Co., Ltd.).

[0021] (Removal process of organic volatile components) This process can remove volatile impurities such as unreacted polymerizable monomers and by-products from the toner particle dispersion obtained in the polymerization process. The organic volatile component removal process can be carried out under atmospheric pressure or reduced pressure, and various removal methods can be used to remove organic volatile components to the desired concentration.

[0022] (Washing process, solid-liquid separation process) To remove the dispersion stabilizer adhering to the surface of the toner particles, the toner particle dispersion can be treated with an acid or alkali. After this, the toner particles are separated from the liquid phase by a general solid-liquid separation method. However, to completely remove the acid or alkali and the dispersion stabilizer components dissolved in them, water is added again to wash the toner particles. This washing process is repeated several times until sufficient washing is achieved, after which solid-liquid separation is performed again to obtain wet toner particles.

[0023] (drying process) The resulting wet toner particles can be dried by removing the water and aqueous media they contain. Various drying methods can be used as general drying processes, such as vacuum drying, fluidized bed drying, and airflow drying.

[0024] In this invention, in order to suppress the deterioration of toner performance due to the heat transfer medium used for drying, a loop-type airflow dryer equipped with a first inlet and a second inlet as gas inlets is used.

[0025] In a loop-type airflow dryer, for example, the loop-type airflow dryer 4 shown in Figure 1 heats the gas supplied from the discharge blower 1 using a gas heating device 2 before supplying it. The supplied gas is sent to the loop-type drying pipe 8 from the first inlet 10 and the second inlet 12. To arbitrarily adjust the airflow from the first inlet 10 and the second inlet 12, it is preferable to adjust it by the opening of the airflow adjustment valve 3.

[0026] Wet toner particles are quantitatively supplied from a feeder in the wet toner particle supply hopper 5 and join with the gas circulating in the drying tube 8. The wet toner particles are dried as they circulate with the gas and are sent out of the drying tube 8 system through the discharge port 13.

[0027] The input port 7 refers to the opening formed at the point where the input pipe 6 and the drying pipe 8 or the first blowing pipe 9 are joined. When the first blowing pipe 9 is joined to the input pipe 6, the input port 7 is the opening of the input pipe, which is the part shown by the dotted line in Figure 3. The input port 7 for introducing wet toner particles can be provided at any position relative to the drying pipe 8 and the first blowing pipe 9, but it is more preferable that it be provided at the position where the first blowing pipe 9 is joined. When the input port 7 is joined to the first blowing pipe 9 as shown in Figure 1, the wet toner particles follow the flow of gas blown from the first blowing pipe 9 into the drying pipe, making collisions into the inside of the drying pipe less likely to occur.

[0028] The drying tube 8 is a tube through which wet toner particles circulate. The shape of the drying tube 8 is not particularly limited, but it is preferable that the part where the direction of travel changes has a curved shape.

[0029] The first inlet 10 refers to the opening formed at the joint between the first inlet pipe 9 and the drying pipe 8. The first inlet 10 is provided to supply gas at a lower air velocity than the second inlet 12, thereby providing drying heat while suppressing the collision of toner particles into the drying pipe. The first inlet 10 is located upstream of the wet toner particle transport path 14 (Figure 3) compared to the second inlet 12, and can be positioned as shown in Figures 1 and 2 relative to the drying pipe 8, but is not limited to this. However, it is more preferable that the gas supplied from the first inlet 10 contains wet toner particles before being blown into the drying pipe 8, as shown in Figure 1.

[0030] The second inlet 12 refers to the opening formed at the joint between the second inlet pipe 11 and the drying pipe 8. The second inlet 12 is provided to supply gas at a higher air velocity than the first inlet 10, providing a propulsive force for the wet toner particles to circulate within the drying pipe and to dry them efficiently. This second inlet 12 is located downstream of the first inlet 10 in relation to the wet toner particle transport path 14, and can be provided in the positions shown in Figures 1 and 2 relative to the drying pipe, but is not limited to these positions.

[0031] The outlet 13 refers to the opening formed at the point where the discharge pipe and the drying pipe 8 are joined.

[0032] In the present invention, which uses a loop-type airflow dryer configured as described above, a circulation speed is maintained during the drying of wet toner particles so that the wet toner particles do not collide excessively with the drying tube.

[0033] While airflow drying is highly efficient due to its continuous processing, it requires the use of high-velocity drying gas to break down, transport, and dry the wet toner particles. Furthermore, the wet toner particles experience their highest velocity immediately after passing through the drying gas inlet. This high velocity causes them to collide with the inner walls of the drying tube, resulting in toner fusion. Slowing down this collision velocity is crucial to prevent fusion, but simply reducing the drying gas velocity leads to insufficient drying heat and decreased drying efficiency.

[0034] This invention provides a new air inlet upstream of the conventional air inlet, which allows for a reduction in the velocity of the air while still compensating for the insufficient amount of drying heat. As a result, it is possible to suppress fusion due to collision without reducing drying efficiency.

[0035] In this invention, the air velocity A of the gas supplied from the first inlet (reference numeral 10 in Figure 1) is 4.5 m / s or more and 14.5 m / s or less. If the air velocity A of the gas supplied from the first inlet is 4.5 m / s or more, it is possible to provide the air velocity necessary for circulation in the drying tube, and a decrease in drying efficiency can be prevented. However, if it is less than 4.5 m / s, the speed from the first inlet is too slow, causing wet toner particles to flow back into the inlet, making drying impossible. If the air velocity A of the gas supplied from the first inlet is 14.5 m / s or less, the air velocity inside the drying tube can be increased in stages, making it less likely for toner to collide with the inner wall of the drying tube, and thus suppressing fusion adhesion.

[0036] In this invention, the air velocity of the gas supplied from the second inlet (reference numeral 12 in Figure 1) is 19.0 m / s or more and 38.5 m / s or less. If the air velocity of the gas supplied from the second inlet is 19.0 m / s or more, it is possible to provide the air velocity necessary for circulation in the drying tube, and a decrease in drying efficiency can be prevented. If the air velocity of the gas supplied from the second inlet is 38.5 m / s or less, the air velocity inside the drying tube is sufficiently low, making it less likely for the toner to collide with the inner wall of the drying tube, and thus fusion adhesion can be suppressed.

[0037] In the present invention, when the airflow rate C of the gas supplied from the first inlet and the airflow rate D of the gas supplied from the second inlet, the following equation is satisfied. 0.20 ≤ C / (C+D) ≤ 0.60

[0038] If C / (C+D) is 0.20 or higher, fusion inside the drying tube can be suppressed by blowing in gas at a moderate airflow rate. Furthermore, a value of 0.40 or higher is even more preferable. If C / (C+D) is 0.60 or lower, disturbance to the circulation flow inside the drying tube can be suppressed, preventing accidental recovery at the discharge section and allowing the moisture content of the dried toner particles to be kept at a low level.

[0039] In the present invention, it is more preferable that the temperature of the airflow (gas) supplied from the first and second inlet is 60°C or higher and 80°C or lower. If the temperature of the gas supplied from the inlet is 60°C or higher, a sufficient amount of heat can be supplied to the wet toner particles, thereby increasing the drying efficiency. If the temperature of the gas supplied from the inlet is 80°C or lower, the toner can be dried without becoming thermally weakened, thereby preventing fusion.

[0040] In this invention, it is more preferable to have multiple second inlets. Having multiple second inlets prevents localized increases in air velocity, thus allowing for a more uniform velocity distribution within the drying pipe. This improves the suppression of fusion and enhances drying efficiency. Furthermore, there may also be multiple first inlets.

[0041] In the present invention, it is more preferable that the glass transition temperature (Tg) of the toner particles is 40°C or higher. A Tg of 40°C or higher allows the toner to dry without melting, thus preventing fusion inside the drying pipe.

[0042] (Classification process) The toner particles obtained in this way have a sufficiently sharp particle size compared to toners produced by conventional grinding methods. However, if an even sharper particle size is required, particles that deviate from the desired particle size distribution can be separated and removed by classifying them using an air classifier or similar device.

[0043] Next, we will explain the constituent materials of the toner used in the manufacturing of the toner described above.

[0044] <polymerizable monomers> Suitable polymerizable monomers for use in the toner of the present invention include vinyl polymerizable monomers capable of radical polymerization. These vinyl polymerizable monomers can be monofunctional or polyfunctional. Examples of monofunctional polymerizable monomers include the following:

[0045] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, 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, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl Acrylic monomers such as acrylate and 2-benzoyloxyethyl acrylate; methacrylate polymerizable monomers such as 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, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; vinyl esters such as methylene aliphatic monocarboxylic acid esters, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

[0046] Examples of polyfunctional polymerizable monomers include: diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis(4-(acryloxydiethoxy)phenyl)propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Polyethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 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.

[0047] In the present invention, the above-mentioned monofunctional polymerizable monomers are used individually, in combination of two or more types, or in combination with the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers. Among the above-mentioned monomers, styrene or styrene derivatives are used individually or in combination, or mixed with other monomers, which is preferable from the viewpoint of toner development characteristics and durability.

[0048] <Coloring agent> The following organic pigments or dyes and inorganic pigments are examples of colorants that are preferably used in the present invention.

[0049] As organic pigments or organic dyes used as cyanide colorants, copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds can be used.

[0050] Specifically, the following can be mentioned: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, 66.

[0051] Examples of organic pigments or dyes used as magenta-based colorants include the following:

[0052] Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolon compounds, thioindigo compounds, and perylene compounds.

[0053] Specifically, the following can be listed: CI Pigment Red 2, 3, 5, 6, 7, CI Pigment Violet 19, CI Pigment Red 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254.

[0054] As organic pigments or dyes used as yellow colorants, compounds such as condensed azo compounds, isoin dorinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are commonly used.

[0055] Specifically, the following can be listed: CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 111, 120, 127, 128, 129, 147, 154, 155, 168, 174, 175, 176, 180, 181, 191, 194.

[0056] As black colorants, carbon black and those colored black using the above-mentioned yellow / magenta / cyan colorants are used.

[0057] These colorants can be used individually, in combination, or in solid solution form. The colorants used in the toner of the present invention are selected based on their hue angle, saturation, brightness, lightfastness, OHP transparency, and dispersibility in the toner.

[0058] The coloring agent is preferably used in an amount of 1 to 20 parts by mass per 100 parts by mass of the binder resin.

[0059] When selecting colorants, attention must be paid to their polymerization inhibitory properties and water-phase migration properties. In particular, many dyes and carbon blacks have polymerization inhibitory properties, so caution is required when using them. Preferably, these should be surface modified, for example, by hydrophobizing them with a substance that does not inhibit polymerization. One method for surface treating dyes is to polymerize polymerizable monomers in the presence of these dyes beforehand, and then add the resulting colored polymer to toner raw materials such as polymerizable monomer compositions. Furthermore, in addition to the same treatment as for dyes, carbon black may also be grafted with a substance that reacts with the surface functional groups of carbon black, such as a polyorganosiloxane.

[0060] <Release agent> As the release agent used in the present invention, a wax that is solid at room temperature is preferable in terms of toner blocking resistance, durability for multiple sheets, low-temperature fixing properties, and offset resistance.

[0061] Examples of waxes include: paraffin wax, polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer-Tropsch wax, amide wax, higher fatty acids, long-chain alcohols, ester waxes and their graft compounds, and their block compounds. These waxes have low molecular weight components removed and are preferably those that produce a sharp maximum endothermic peak in the endothermic curve obtained by differential scanning calorimeter. Linear ester waxes are particularly suitable for improving the light transmittance of images fixed to an OHP. Linear ester waxes are preferably contained in an amount of 1 to 40 parts by mass, more preferably 4 to 30 parts by mass, per 100 parts by mass of polymerizable monomer.

[0062] In the present invention, a second release agent having a melting point less than 80°C can be used in combination to increase the plasticity of the toner particles and improve their fixation in the low-temperature range. Preferably, the second release agent is a wax of a linear alkyl alcohol having 15 to 100 carbon atoms, a linear fatty acid, a linear acid amide, a linear ester, or a montan derivative. It is more preferable that impurities such as liquid fatty acids have been removed from these waxes beforehand.

[0063] <Charge control agent> The toner produced by the present invention may contain a charge control agent. Known charge control agents can be used. For example, the following can be used to control the toner's charge properties: Organometallic compounds and chelate compounds are effective, including monoazo dye metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. Furthermore, the following can be used: Urea derivatives, metal-containing salicylic acid compounds, quaternary ammonium salts, calixarenes, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic sulfonic acid copolymers, and nonmetallic carboxylic acid compounds.

[0064] Examples of substances that control the positive charge of toner include: nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate; onium salts such as phosphonium salts and their lake pigments; triphenylmethane dyes and their lake pigments (lake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstenmolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, or ferrocyanide); and metal salts of higher fatty acids. These can be used individually or in combination of two or more. Among these, charge control agents such as quaternary ammonium salts are particularly preferred.

[0065] These charge control agents are preferably used in an amount of 0.01 parts by mass to 20 parts by mass, more preferably 0.5 parts by mass to 10 parts by mass, per 100 parts by mass of polymerizable monomer.

[0066] <Polymerization initiator> Polymerization initiators that can be used in the present invention include azo polymerization initiators. Examples of azo polymerization initiators include: 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonnitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobismethylbutyronitrile.

[0067] In addition, organic peroxide polymerization initiators can be used. Examples of organic peroxide polymerization initiators include: benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, and tert-butyl peroxypivalate.

[0068] In addition, redox polymerization initiators combining oxidizing and reducing substances can be used. Examples of oxidizing substances include hydrogen peroxide, inorganic peroxides such as persulfates (sodium salts, potassium salts, ammonium salts, etc.), and oxidizing metal salts such as tetravalent cerium salts. Examples of reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, trivalent chromium salts), ammonia, lower amines (amines with 1 to 6 carbon atoms such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium hydrosulfite, sodium bisulfite, sodium sulfite, sodium formaldehyde sulfoxylate, lower alcohols (with 1 to 6 carbon atoms), ascorbic acid or its salts, and lower aldehydes (with 1 to 6 carbon atoms). Polymerization initiators are selected based on their 10-hour half-life temperature and are used alone or in combination. The amount of polymerization initiator added varies depending on the desired degree of polymerization, but generally, 0.5 to 20 parts by mass are added per 100 parts by mass of polymerizable monomer.

[0069] <Crosslinking agent> Various crosslinking agents can also be used in the present invention. Examples of crosslinking agents include: divinylbenzene, 4,4'-divinylbiphenyl, hexanediol diacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, glycidyl acrylate, glycidyl methacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate.

[0070] <Binding resin> There are no particular restrictions on the binder resin used in the dissolution suspension method, etc., and it can be appropriately selected from known ones, but examples include homopolymers or copolymers of styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone.

[0071] Examples of polymers of styrene or its substituted products include polystyrene, poly-p-chlorostyrene, polyvinyltoluene, and the like. Examples of styrene-based copolymers include styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, and the like.

[0072] Particularly representative binder resins include, for example, polystyrene resin, polyester resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene resin, and polypropylene resin. These may be used individually or in combination of two or more.

[0073] <External additives> In the manufacturing method of the present invention, external additives can be used to impart various properties to the toner. From the viewpoint of durability when added to the toner, it is preferable that the particle size of the external additive is 1 / 10 or less of the average particle size of the toner particles. Examples of external additives 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 and silica.

[0074] These external additives are used in amounts of 0.01 parts by mass to 10 parts by mass per 100 parts by mass of toner particles, preferably 0.05 parts by mass to 5 parts by mass. The external additives may be used individually or in combination, but it is more preferable that each additive has been hydrophobized.

[0075] <Magnetic materials> The manufacturing method of the present invention can also be applied to the manufacture of magnetic toner containing a magnetic material, and the magnetic material contained in the toner can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner is iron oxide such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; or alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

[0076] These magnetic materials should have a volume-average particle size (Dv) of 0.5 μm or less, preferably 0.1 to 0.5 μm.

[0077] The volume-average particle size (Dv) of a magnetic material is determined using a transmission electron microscope (TEM). The equivalent diameter of a circle equal to the projected area of ​​100 magnetic materials in the field of view is determined from a photograph taken at a magnification of 10,000x or 40,000x, and the volume-average particle size is calculated based on this.

[0078] The amount of the above-mentioned magnetic material in the toner is preferably 20 parts by mass or more and 200 parts by mass or less, and particularly preferably 40 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of polymerizable monomer.

[0079] Furthermore, the magnetic properties of the above magnetic material when 800 kA / m is applied are saturation magnetization (σs) 50~200 Am 2 / kg, residual magnetization (σr)2~20Am 2 A material with a density of / kg is preferred. The magnetic properties of the magnetic material are measured using a vibration-type magnetometer VSM P-1-10 (manufactured by Toei Kogyo Co., Ltd.) at room temperature of 25°C with an external magnetic field of 79.6 kA / m.

[0080] Furthermore, to improve the dispersibility of these magnetic materials in toner particles, it is preferable to hydrophobize the surface of the magnetic materials. Coupling agents such as silane coupling agents and titanium coupling agents are used for the hydrophobization treatment. Among these, silane coupling agents are preferred. Examples of silane coupling agents include: vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacrylateoxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

[0081] <Developer> As described above, the toner produced by the present invention can be used as either a one-component or two-component developer.

[0082] In the case of magnetic toners, which are one-component developers containing a magnetic material, a method is used in which a magnet built into the developing sleeve is used to transport and charge the magnetic toner. Alternatively, when using non-magnetic toners that do not contain a magnetic material, a method is used in which a blade and fur brush are used to forcibly generate frictional charge on the developing sleeve, causing the toner to adhere to the sleeve and be transported.

[0083] When the toner obtained by the manufacturing method of the present invention is used as a two-component developer, a carrier is used together with the toner as the developer. The carrier used in the present invention is not particularly limited, but mainly consists of iron, copper, zinc, nickel, cobalt, manganese, and chromium atoms in single or combined ferrite states.

[0084] The carrier shape is also important because it allows for wide-ranging control of saturation magnetization and electrical resistance. For example, it is preferable to select spherical, flattened, or amorphous shapes, and further control the microstructure of the carrier surface, such as surface roughness. Generally, a method is used in which carrier core particles are generated in advance by calcining and granulating the above-mentioned metal compound, and then coated with resin. To reduce the load of the carrier on the toner, there is a method of kneading the metal compound and resin, then crushing and classifying them to obtain low-density dispersed carriers. Furthermore, it is also possible to use a method in which a mixture of the metal compound and a polymerizable monomer is directly suspended and polymerized in an aqueous medium to obtain polymerized carriers dispersed in a spherical shape.

[0085] The carrier particle size was measured using a dry disperser (Rhodos) manufactured by SYNPATEC. <rodos>) equipped with a laser diffraction particle size distribution analyzer (Heros <helos>The particle size is measured as the 50% average particle size based on the carrier volume using ).

[0086] The 50% average particle size of these carriers, based on volume, is preferably 10 to 100 μm, more preferably 20 to 50 μm.

[0087] When preparing a two-component developer, the mixing ratio of the carrier to the toner in this invention is 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Good results are usually obtained within this range.

[0088] The water content and glass transition temperature in the examples were measured according to the following method.

[0089] <Measurement of moisture content> The moisture content was calculated by placing 5g of toner particles in an aluminum dish, weighing it precisely (A[g]), leaving it in a dryer set to 105°C for 1 hour, and then weighing it precisely after cooling (B[g]), using the following formula. Moisture content [%]=((AB) / A)×100

[0090] <Measurement of the glass transition temperature (Tg) of toner particles> The glass transition temperature (Tg) was measured using a differential scanning calorimetry spectrometer "Q1000" (TA Instruments) in accordance with ASTM D3418-82. The temperature correction for the instrument's detection unit was performed using the melting points of indium and zinc, and the heat correction was performed using the heat of fusion of indium. Specifically, approximately 3 mg of toner particles were accurately weighed and placed in an aluminum pan. An empty aluminum pan was used as a reference, and measurements were taken within the measurement range of 30 to 200°C at a heating rate of 10°C / min. During this heating process, a change in specific heat was obtained in the temperature range of 40°C to 100°C. The straight line extending from the baseline before the change in specific heat was defined as the first straight line, the straight line extending from the baseline after the change in specific heat was defined as the second straight line, and the straight line equidistant in the vertical direction from the first and second straight lines was defined as the third straight line. The temperature at the intersection of the third straight line and the stepped portion of the differential thermal curve (the so-called midpoint glass transition temperature) was defined as the glass transition temperature Tg of the toner particles. [Examples]

[0091] The present invention will be specifically described below with reference to the following examples. Specifically, an example is shown in which wet toner particles are produced and the obtained wet toner particles are subjected to a drying means for drying under predetermined conditions.

[0092] [Preparation of wet toner particles 1] Wet toner particles 1 were manufactured according to the following procedure.

[0093] (Preparation process of pigment dispersion composition) For every 23.0 parts by mass of styrene, 1.88 parts by mass of CI Pigment Yellow 155 and 0.58 parts by mass of a charge control agent (Bontron E88; manufactured by Orient Chemical Industry Co., Ltd.) were prepared. These were introduced into an attritor (manufactured by Nippon Coke Industries Co., Ltd.), and stirred at 200 rpm at 25°C for 300 minutes using zirconia beads with a radius of 5.00 mm to prepare a pigment dispersion composition.

[0094] (Preparation process of colorant-containing composition) The following materials were placed in the same container and mixed and dispersed using a TK homomixer (manufactured by Primix Co., Ltd.) at a peripheral speed of 20 m / sec. • Pigment dispersion composition: 25.02 parts by mass • Styrene 11.51 parts by mass n-butyl acrylate 13.42 parts by mass • Polyester resin 1.92 parts by mass • Styrene-methacrylate-methyl methacrylate-α-methylstyrene copolymer 5.75 parts by mass (styrene / methacrylic acid / methyl methacrylate / α-methylstyrene = 80.85 / 2.50 / 1.65 / 15.0, Mp = 19,700, Mw = 7,900, TgB = 96℃, acid value = 12.0 mgKOH / g, Mw / Mn = 2.1) • Sulfonic acid group-containing resin (Acrybase FCA-1001-NS, manufactured by Fujikura Chemical Co., Ltd.) 0.05 parts by mass Furthermore, after heating to 60°C, 4.79 parts by mass of microcrystalline wax (Hi-Mic-2065; manufactured by Nippon Seiro Co., Ltd.), which has a melting point of 75°C, was added as a release agent, and the mixture was dispersed and mixed for 30 minutes. Then, 4.31 parts by mass of the polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) was dissolved to prepare a colorant-containing composition.

[0095] (Preparation process of aqueous dispersion media) In a granulation tank, 129.71 parts by mass of deionized water, 2.51 parts by mass of sodium phosphate dodecahydrate, and 1.13 parts by mass of 10% hydrochloric acid were added to prepare an aqueous sodium phosphate solution, which was then heated to 60°C. 1.46 parts by mass of calcium chloride dihydrate was dissolved in 10.20 parts by mass of deionized water to obtain an aqueous calcium chloride solution. The aqueous calcium chloride solution was added to the aforementioned aqueous sodium phosphate solution, and the mixture was stirred for 30 minutes at a peripheral speed of 25 m / sec using a TK homomixer (manufactured by Primix Co., Ltd.).

[0096] (granulation process) A colorant-containing composition was added to an aqueous dispersion medium and stirred at a peripheral speed of 25 m / sec for 20 minutes at a temperature of 60°C and under a nitrogen atmosphere using a TK homomixer (manufactured by Primix Co., Ltd.) to obtain a dispersion of the colorant-containing composition.

[0097] (Reaction process) The dispersion of the colorant-containing composition was transferred to another tank and stirred with a paddle agitator while the temperature was raised to 70°C (reaction temperature) and the mixture was allowed to react for 4 hours. After that, the temperature was further raised to 85°C and the mixture was allowed to react for 2 hours to obtain a dispersion of toner particles.

[0098] (Washing / Filtration / Process) After cooling the toner particle dispersion that had undergone the organic volatile matter removal process, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 2 hours. Subsequently, the toner particle dispersion was filtered, and the filtrate was washed and filtered with an equal volume of water to obtain wet toner particles 1. The weight-average particle size of wet toner particles 1 was 7.0 μm, and the water content was 24%.

[0099] [Preparation of wet toner particles 2 and 3] In the preparation process of the colorant-containing composition, wet toner particles 2 and 3 were obtained under the same conditions and methods as wet toner particle 1, except for the differences shown in Table 1.

[0100] [Table 1]

[0101] [Example 1] (drying process) The wet toner particles 1 were dried using the drying system shown in Figure 1 under the following conditions to obtain the toner particles 1. • Wind speed A supplied from the first inlet: 10.0 m / s • Wind speed B supplied from the second inlet: 30.0 m / s • The relationship between the airflow rate C supplied from the first inlet and the airflow rate D supplied from the second inlet is C / (C+D): 0.50 • Gas temperature: 70℃ • Number of second air inlets: 3 Table 2 shows the measured glass transition temperature of the obtained toner particles 1, and Table 3 shows the water content.

[0102] After the drying process was completed, the drying efficiency was evaluated when toner particles with a moisture content of less than 1.0% were obtained, in order to assess the conditions under which these conditions were met. The evaluation criteria for drying efficiency are as follows: A: Supply volume of 70 kg / h or more B: Supply volume of 60 kg / h or more but less than 70 kg / h C: Supply volume of 50 kg / h or more but less than 60 kg / h D: Supply volume less than 50 kg / h, or moisture content of 1.0% or more.

[0103] Furthermore, the drying apparatus was disassembled, and the fusion status inside the drying tube was checked using an endoscope or visual inspection. The evaluation criteria for toner fusion are as follows: A: No adhesion B: There is a slight residue, but it can be easily removed. C: There is a lot of adhesion, and there is fused material with a thickness of 1 mm to less than 1 cm. D: Adhesion has accumulated, and there is fused material with a thickness of 1 cm or more.

[0104] The evaluation results are shown in Table 3.

[0105] [Examples 2 and 3] Toner particles 2 were obtained using the same conditions and methods as in Example 1, except that the wind velocity A of the gas supplied from the first inlet was set to 4.6 m / s during the drying process. Toner particles 3 were also obtained using the same conditions and methods as in Example 1, except that the wind velocity A of the gas was set to 14.3 m / s.

[0106] Table 2 shows the measured glass transition temperatures of the obtained toner particles 2 and 3, and Table 3 shows their water content. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0107] [Examples 4 and 5] Toner particles 4 were obtained using the same conditions and methods as in Example 1, except that the wind velocity B of the gas supplied from the second inlet was set to 19.0 m / s during the drying process. Toner particles 5 were also obtained using the same conditions and methods as in Example 1, except that the wind velocity B of the gas was set to 38.4 m / s.

[0108] The glass transition temperatures of the obtained toner particles 4 and 5 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0109] [Examples 6 and 7] In the drying process, toner particles 6 were obtained under the same conditions and methods as in Example 1, except that the relationship between the airflow rate C of the gas supplied from the first inlet and the airflow rate D of the gas supplied from the second inlet, C / (C+D), was set to 0.20. Toner particles 7 were also obtained under the same conditions and methods as in Example 1, except that the relationship between C / (C+D) was set to 0.60.

[0110] The measured glass transition temperatures of the obtained toner particles 6 and 7 are shown in Table 2, and the water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and is shown in Table 3.

[0111] [Examples 8 and 9] Toner particles 8 were obtained in the same conditions and method as in Example 1, except that the temperature of the gas supplied from the first and second nozzles was set to 60°C during the drying process. Toner particles 9 were also obtained in the same conditions and method as in Example 1, except that the temperature of the gas supplied from the first and second nozzles was set to 80°C.

[0112] The glass transition temperatures of the obtained toner particles 8 and 9 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0113] [Examples 10, 11] In the drying process, toner particles 10 were obtained under the same conditions and methods as in Example 1, except that the wet toner particles 2 were dried. Furthermore, toner particles 11 were obtained under the same conditions and methods as in Example 1, except that the wet toner particles 3 were dried.

[0114] The glass transition temperatures of the obtained toner particles 10 and 11 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0115] [Examples 12 and 13] In the drying process, toner particles 12 were obtained under the same conditions and methods as in Example 1, except that the number of second air inlets was two. Toner particles 13 were also obtained under the same conditions and methods as in Example 1, except that the number of second air inlets was one.

[0116] The glass transition temperatures of the obtained toner particles 12 and 13 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0117] [Example 14] Toner particles 14 were obtained under the same conditions and methods as in Example 1, except that the relationship between the airflow rate C of the gas supplied from the first inlet and the airflow rate D of the gas supplied from the second inlet, C / (C+D), was set to 0.4 during the drying process.

[0118] The glass transition temperature of the obtained toner particles 14 is shown in Table 2, and the water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and is shown in Table 3.

[0119] [Example 15] Toner particles 15 were obtained under the same conditions and methods as in Example 1, except that the drying system shown in Figure 2 was used during the drying process.

[0120] The glass transition temperature of the obtained toner particles 15 is shown in Table 2, and the water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and is shown in Table 3.

[0121] [Comparative Example 1] In the drying process, drying was carried out under the same conditions and methods as in Example 1, except that the air velocity A of the gas supplied from the first inlet was set to 4.2 m / s. As a result, wet toner particles flowed back into the first inlet, and it was not possible to obtain toner particles.

[0122] [Comparative Example 2] Toner particles 16 were obtained under the same conditions and methods as in Example 1, except that the wind velocity A of the gas supplied from the first inlet was set to 14.6 m / s during the drying process. The glass transition temperature of the obtained toner particles 16 is shown in Table 2, and the moisture content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and is shown in Table 3.

[0123] [Comparative Examples 3 and 4] Toner particles 17 were obtained using the same conditions and methods as in Example 1, except that the wind velocity B of the gas supplied from the second inlet was set to 18.9 m / s during the drying process. Toner particles 18 were also obtained using the same conditions and methods as in Example 1, except that the wind velocity B of the gas supplied from the second inlet was set to 38.6 m / s.

[0124] The glass transition temperatures of the obtained toner particles 17 and 18 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0125] [Comparative Examples 5-7] Toner particles 19 were obtained under the same conditions and methods as in Example 1, except that the relationship between the airflow rate C of the gas supplied from the first inlet and the airflow rate D of the gas supplied from the second inlet, C / (C+D), was set to 0.00 during the drying process. Toner particles 20 were obtained under the same conditions and methods as in Example 1, except that the relationship between C / (C+D) was set to 0.18. Furthermore, toner particles 21 were obtained under the same conditions and methods as in Example 1, except that the relationship between C / (C+D) was set to 0.61.

[0126] The glass transition temperatures of the obtained toner particles 19-21 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0127] [Comparative Examples 8 and 9] Toner particles 22 were obtained under the same conditions and methods as in Example 1, except that the temperature of the gas supplied from the first and second inlets was set to 59°C during the drying process. Toner particles 23 were also obtained under the same conditions and methods as in Example 1, except that the temperature of the gas supplied from the first and second inlets was set to 81°C.

[0128] The glass transition temperatures of the obtained toner particles 22 and 23 are shown in Table 2, and their water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 3.

[0129] [Comparative Example 10] In the drying process, toner particles 24 were obtained under the same conditions and methods as in Example 1, except that the temperature of the gas supplied from the first and second inlet was set to 81°C and the amount of wet toner supplied was set to 80 kg / h.

[0130] The glass transition temperature of the obtained toner particles 24 is shown in Table 2, and the water content is shown in Table 3. The evaluation was performed in the same manner as in Example 1, and is shown in Table 3.

[0131] [Table 2]

[0132] [Table 3] [Explanation of Symbols]

[0133] 1: Discharge blower, 2: Gas heating device, 3: Air volume control valve, 4: Loop-type airflow dryer, 5: Wet toner particle supply hopper, 6: Inlet pipe, 7: Inlet port, 8: Drying pipe, 9: First blowing pipe, 10: First blowing port, 11: Second blowing pipe, 12: Second blowing port, 13: Outlet, 14: Wet toner particle transport path< / helos> < / rodos>

Claims

1. A method for producing toner particles, comprising a step of drying wet toner particles produced in an aqueous dispersion medium by a drying means, the drying means is a loop-type airflow dryer that supplies the wet toner particles to an airflow circulating through a loop-type drying tube to dry them; The loop-type flash dryer is (i) a loop-type drying tube; (ii) an inlet for supplying the wet toner particles to the drying tube; (iii) an outlet for discharging dried toner particles from the drying tube; and (iv) a first inlet for blowing gas into the drying tube; (v) a second inlet for blowing gas into the drying tube; Equipped with the first blowing port is located upstream of the second blowing port with respect to a transport path of the wet toner particles; The wind speed of the gas supplied from the first blowing port is A (m / s), The wind speed of the gas supplied from the second blowing port is B (m / s), The volume of gas supplied from the first blowing port is C (m 3 / s), The volume of gas supplied from the second blowing port is D (m 3 / s), A, B, C, and D satisfy the following formulas (1), (2), and (3), The temperature of the airflow supplied from the first blowing port and the second blowing port is 60°C or higher and 80°C or lower.

1. A method for producing toner particles, comprising: 4.5≦A≦14.5 (1) 19.0≦B≦38.5 (2) 0.20≦C / (C+D)≦0.60 (3)

2. 2. The method for producing toner particles according to claim 1, wherein C and D satisfy the following formula (3)': 0.40≦C / (C+D)≦0.60 (3)'

3. 3. The method for producing toner particles according to claim 1, wherein the loop-type flash dryer is provided with a plurality of the second blowing ports.

4. 4. The method for producing toner particles according to claim 1, wherein the toner particles have a glass transition temperature (Tg) of 40° C. or higher.

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