Toner manufacturing method

Abstract

To provide a toner manufacturing method for reducing adhesion of scale to a production device such as a wall surface of a reaction tank and a stirring blade.SOLUTION: A toner manufacturing method has a particle forming step in which resin particles are formed with the generation of bubbles in an aqueous medium. The aqueous medium contains fine bubbles. The number average particle diameter of the fine bubbles is 1.0×101 nm or more and 1.0×105 nm or less. The number concentration of the fine bubbles is 1.00×105 / mL or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a toner used in electrophotography, electrostatic recording, and toner jet recording. [Background technology]

[0002] As a method for producing toner, a suspension polymerization method, an emulsion polymerization aggregation method, etc. have been proposed in which a mixture of crystalline components such as polymerizable monomers, colorants, release agents, and crystalline resins is dispersed in an aqueous medium to obtain toner particles. The above-mentioned wet production method for producing toner in an aqueous medium has properties such as the ability to encapsulate release agents and crystalline resins and the ease of controlling the shape, and therefore has superior developability and transferability compared to the pulverization method, which is a dry production method that does not use an aqueous medium. However, such wet toner production methods have the following problems to be solved. For example, under wet conditions, bubbles can be generated during the polymerization reaction depending on the stirring conditions and toner formulation. These bubbles come into contact with a wide area of ​​the reaction vessel wall and the gas-liquid interface of the stirring blades. The bubbles that come into contact with the reaction vessel wall and the stirrer melt or undergo chemical reactions due to heat, forming hard scales. Furthermore, as these deposits accumulate during continuous production, problems such as poor uniform stirring in the reaction vessel, poor temperature control due to deposits, and clogged piping occur. Cleaning the equipment to remove deposits requires time and effort, and the reaction using the reaction vessel must be suspended during this time, resulting in productivity problems. Therefore, there is a widespread demand for methods to suppress the generation of bubbles. Patent Document 1 discloses a production method that reduces scale deposition by, for example, freely dispersing a dispersion stabilizer in a reaction system using a continuous polymerization method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-92184 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, although it is expected that a certain degree of effect in suppressing scale deposition can be achieved by shortening the time that the foam remains in the reaction vessel, foam is inevitably generated even if the time is shortened. Since scale is generated due to the foam, further improvements in suppressing the amount of scale deposition are needed. The present invention provides a method for producing toner that can suppress scale adhesion to production equipment such as reaction vessel walls and stirring blades, and can also reduce coarse particles that do not meet the specifications. [Means for solving the problem]

[0005] The present invention relates to a method for producing a toner, which includes a particle formation step in which resin particles are formed in an aqueous medium while bubbles are generated, wherein the aqueous medium contains fine bubbles; The number-average particle size of the fine bubbles is 1.0 x 10 1 nm or more 1.0×10 5 nm or less, and the number concentration of the fine bubbles is 1.00 × 10 5 The present invention relates to a method for producing a toner, characterized in that the toner concentration is 1 / mL or more. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a method for producing toner that can suppress scale adhesion to production equipment such as reaction vessel walls and stirring blades, and also reduce coarse particles that are non-standard toner particles. DETAILED DESCRIPTION OF THE INVENTION

[0007] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0008] [Features of the present invention] The toner production method of the present invention is a toner production method including a particle formation step in which resin particles are formed in an aqueous medium while bubbles are generated, the aqueous medium is an aqueous medium containing fine bubbles, The number-average particle size of the fine bubbles is 1.0 x 10 1 nm or more 1.0×10 5 nm or less, and the number concentration of the fine bubbles is 1.00 × 10 5 This toner production method is characterized by having a concentration of at least 1 / mL. By using this toner production method, it is possible to produce toner particles that are inhibited from adhering to production equipment such as reaction vessel walls and stirring blades.

[0009] The inventors believe that the reason why the effects of the present invention are exhibited is as follows.

[0010] In the particle formation step, the number average particle size of the fine bubbles contained in the aqueous medium is 1.0 × 10 1 nm~ or more 1.0×10 5 nm or less, and the number concentration of the fine bubbles contained in the aqueous medium is 1.00 × 10 5 When there are more than 10 ... B=4aπr 2 -4 / 3bπr 3 ··· Formula (A) B: Surface energy of the bubble r: bubble radius a and b: Coefficients that change depending on the medium, etc.

[0011] This formula (A) shows that when the bubble diameter is sufficiently small, the smaller the bubble diameter, the more unstable the surface energy of the bubbles. In other words, by using the fine bubbles as nuclei, the bubble diameter caused by the polymerization reaction and stirring becomes smaller, and the surface energy of the bubbles becomes unstable. When the surface energy of the bubbles becomes unstable, the bubble state cannot be maintained, which is thought to lead to rapid bubble breakage and suppression of scale adhesion.

[0012] On the other hand, if fine bubbles are not present in the particle formation process, there are no nuclei such as fine bubbles when bubbles are generated by polymerization reactions or stirring, and therefore the bubbles that are generated have larger diameters that are more energetically stable, and it is thought that their presence over a long period of time worsens scale adhesion.

[0013] [Main configuration of the present invention] The number-average particle size of the fine bubbles is 1.0 x 10 1 nm or more 1.0×10 5 nm or less, and is 1.0 × 10 1 nm or more 1.0×10 3 The particle size is preferably in the range of 1.0×10 nm or less. By being in the above range, fine bubbles can exist in the aqueous medium for a long time, and the effects of the present invention can be obtained. 1 nm or more 1.0×10 3 Fine bubbles in the range of 100 nm or less are specifically called ultrafine bubbles. One of the characteristics of ultrafine bubbles is that they are difficult to disappear and can exist for a long time. Therefore, the effects of the present invention can be more easily achieved.

[0014] One method for controlling the particle size of fine bubbles is to use membrane separation. Specifically, fine bubbles can be separated and classified into those with the desired diameter by passing them through multiple filters with the desired pore size.

[0015] The number-average particle size of fine bubbles in the present invention is a value measured using the aqueous medium used as a raw material. Even if an aqueous medium containing fine bubbles with a different number-average particle size is added during the production process, the number-average particle size is calculated from a theoretical value taking into account the number and number-average particle size of the fine bubbles added in the particle formation process.

[0016] The number concentration of the fine bubbles is 1.00 x 10 5 cells / mL or more, preferably 1.00 × 10 6 The higher the concentration of fine bubbles, the more core fine bubbles there are, and the more likely it is that the effects of the present invention will be achieved.

[0017] The number concentration of fine bubbles per mL can be controlled by passing them through a membrane separation filter, which concentrates the fine bubbles and increases their number. The number concentration can also be increased by circulating the fine bubbles through a known fine bubble generator. Conversely, the number concentration can be decreased by adding an aqueous medium to dilute the solution.

[0018] The number concentration of fine bubbles in this invention is a value measured using the aqueous medium used as a raw material. If aqueous medium is added during production, the number concentration is calculated from the theoretical value taking into account the aqueous medium added in the particle formation process. Even if fine bubbles with a different number concentration (particles / mL) are added, the number concentration is similarly calculated from the theoretical value in the particle formation process.

[0019] When the particle formation process is a process of polymerizing a polymerizable monomer in droplet particles dispersed in an aqueous medium using a polymerization initiator to form resin particles, it is believed that the bubbles generated are mainly due to gas generated as the polymerization initiator cleaves. The bubbles generated as described above tend to be more numerous and involve a greater amount of heat the earlier the polymerization initiator is added. In this case, if there are an abundance of fine bubbles that serve as nuclei, the diameter of the generated bubbles becomes smaller, and small bubbles that become energetically unstable due to the generated thermal energy quickly break down.

[0020] On the other hand, when the particle formation process is a process in which the aqueous medium is stirred, it is considered that the bubbles generated are predominantly those generated in association with stirring. The bubbles generated due to the above-mentioned causes in the present invention are constantly generated by stirring. In this case, if there are an abundant amount of fine bubbles that serve as nuclei, the diameter of the generated bubbles will be small. Small bubbles that are energetically unstable will constantly break, but when the temperature is increased during a process that requires a reaction in the production process, they will receive more energy from the outside, further promoting the breakage of bubbles.

[0021] When the discharge rate of the agitator in the particle formation step is Q (L / min), the total amount of the aqueous medium is V (L), and the temperature of the aqueous medium is T (°C), it is preferable to satisfy the following relational expression (1). T<500×Q / V+30... Formula (1)

[0022] Equation (1) represents the relationship between reaction temperature and discharge volume. In other words, the higher the temperature in the particle formation process, the higher the discharge volume of the agitator blades. This indicates the frequency of contact between the toner particle precursors and the fine bubbles. The higher the reaction temperature in the particle formation process, the more unstable the fine bubbles become, but by increasing the discharge volume of the agitator blades, the frequency of contact between the toner particles and the fine bubbles can be increased. Increasing the frequency of contact between the toner particles and the fine bubbles suppresses the coalescence caused by collisions between toner particles, resulting in an improved and sharper particle size distribution of the toner particles.

[0023] Here, the discharge rate Q (m 3 / sec) is calculated using the following formula: Q=Nq×n×d 3 Nq: Discharge coefficient n: Number of rotations of the stirring blade per unit time (r / sec) d: diameter of the impeller (m)

[0024] Here, the discharge coefficient Nq is a unique value that differs for each agitating impeller, and is a value that is determined by the shape of the agitating impeller, the rotor shape, the screen diameter, and the like.

[0025] The temperature T (° C.) of the aqueous medium is the temperature of the aqueous medium that is measured directly immediately after the aqueous medium reaches the target temperature.

[0026] The temperature T (°C) of the aqueous medium is preferably in the range of 20°C≦T≦80°C, and more preferably in the range of 30°C≦T≦75°C. This is preferable because the temperature is below the upper limit temperature, allowing fine bubbles to stably exist in the aqueous medium. Furthermore, the temperature is above the lower limit temperature, which is preferable from the viewpoint of the reaction in toner particle formation.

[0027] When the number concentration of fine bubbles is A (bubbles / mL) and the number-average particle size of the fine bubbles is B (nm), it is preferable that the following relational expression (2) is satisfied. A / B>1.0×10 3 ··· Equation (2)

[0028] Equation (2) expresses the relationship between the number concentration of fine bubbles and the number-average particle diameter of fine bubbles. In other words, the lower the number concentration of fine bubbles, the smaller the number-average particle diameter of fine bubbles. This indicates the state of the bubbles that form the nuclei. As the number concentration of fine bubbles decreases, the number of bubble nuclei decreases. However, as the number-average particle diameter of fine bubbles decreases, the contact area of ​​bubbles generated during the particle formation process decreases, thereby enabling smaller bubble diameters. A smaller bubble diameter during the particle formation process reduces the surface energy of the bubbles, leading to more rapid bubble breakage and reducing the generation of coarse particles, which are non-standard toner particles caused by bubbles during the particle formation process. Furthermore, while the number-average particle diameter of fine bubbles tends to increase, increasing the number concentration of fine bubbles increases the number of bubble nuclei generated during the particle formation process, ultimately reducing the bubble diameter during the particle formation process. This reduces the generation of coarse particles, which are non-standard toner particles caused by bubbles. That is, the number concentration of fine bubbles and the number average particle size of fine bubbles are interrelated, and coarse particles, which are non-standard toner particles, can be reduced within the range of formula (2).

[0029] Furthermore, the particle formation step is a step of polymerizing polymerizable monomers in droplets dispersed in an aqueous medium using a polymerization initiator to form resin particles, and preferably includes a step of raising the temperature after adding the polymerization initiator, and the temperature is raised at a rate of 0.3°C / min or less in the temperature raising step. This is because, when the gas generated by the cleavage of the polymerization initiator is within the above range, the gas generation is more gradual, and more bubbles can be generated with fine bubbles as nuclei. As a result, the bubble diameter becomes smaller, the surface energy of the bubbles becomes more unstable, leading to quick bubble breakage, and the generation of coarse particles, which are non-standard toner particles caused by bubbles in the particle formation step, can be further reduced.

[0030] The fine bubbles used in the production of the toner particles of the present invention are not particularly limited and may be produced by any conventionally known production method. Specific examples of the fine bubble production method include the following.

[0031] One example of a fine bubble production method is the swirling liquid flow method, which uses the principle of gas phase dispersion through liquid flow shear. In this method, a liquid is poured into a cylindrical container at high speed, generating a high-speed swirling flow inside the container, and the negative pressure generated in the center is used to suck in gas, forming a gas column in the center of the container. The intense shear flow generated at the downstream outlet breaks up the gas column, generating fine bubbles.

[0032] Other fine bubble production methods that use the same principle of gas phase dispersion through liquid flow shear include the static mixer method, mechanical shear method, micro-hole method, and fluid vibration method.

[0033] Furthermore, there are methods for producing fine bubbles that utilize the change in gas solubility in liquid, such as the pressurized dissolution method and the heated precipitation method, methods for producing fine bubbles that utilize the cavitation method, such as the ejector method, the Venturi method, and the ultrasonic method, methods for producing fine bubbles that utilize the phase change of the dispersed phase, such as the mixed vapor condensation method, and methods for producing fine bubbles that utilize the chemical change of the liquid phase, such as the electrolysis method.

[0034] [Toner manufacturing method] The toner manufacturing method is characterized by having a particle formation step in which resin particles are formed in an aqueous medium containing fine bubbles while bubbles are generated. Specifically, known methods for manufacturing toner particles in an aqueous medium, such as a suspension polymerization method, a solution suspension method, or an emulsion aggregation method, can be used. Note that the particle formation step in the present invention includes all steps during which the toner resin particle precursor, or a portion thereof, is in a state of being dispersed in an aqueous medium.

[0035] As an example, the process for producing toner particles by suspension polymerization will be described below step by step.

[0036] The suspension polymerization method is a production method in which particles of a polymerizable monomer composition containing a polymerizable monomer and a colorant are formed in an aqueous medium, and the polymerizable monomer contained in the particles of the polymerizable monomer composition is polymerized to obtain toner particles.

[0037] (Preparation step of 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 the other components, or may be dispersed after all the components have been mixed.

[0038] (granulation process) A polymerizable monomer composition is added to an aqueous medium containing an inorganic dispersion stabilizer, and granulated by dispersing to obtain a polymerizable monomer composition dispersion. The granulation process can be carried out, for example, in a vertical stirring tank equipped with a high-shear stirrer. The high-shear stirrer is not particularly limited, but commercially available stirrers such as a High Shear Mixer (manufactured by IKA Corporation), a TK Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), a TK Filmix (manufactured by Tokushu Kika Kogyo Co., Ltd.), and a Clearmix (manufactured by M Technique Co., Ltd.) can be used.

[0039] 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 alone or in combination of two or more. These function as dispersion stabilizers when present as poorly water-soluble inorganic fine particles in an aqueous medium.

[0040] (Reaction step) The polymerizable monomer in the polymerizable monomer composition dispersion obtained as described above is polymerized to obtain a dispersion of toner particles. A temperature-controllable general stirring tank can be used for the reaction step in the present invention. The polymerization temperature is 40°C or higher, and generally 50 to 90°C. The polymerization temperature may be constant throughout, but may be increased in the latter half of the polymerization step in order to obtain a desired molecular weight distribution.

[0041] Any stirring blade may be used for stirring, as long as it can suspend the polymerizable monomer composition dispersion without stagnation and maintain a uniform temperature in the tank. Examples of the stirring blade or stirring means include common stirring blades such as paddle blades, inclined paddle blades, triple swept blades, propeller blades, disk turbine blades, helical ribbon blades, and anchor blades, as well as "Fullzone" (manufactured by Kobe Steel Pantech Co., Ltd.), "Twinstar" (manufactured by Kobe Steel Pantech Co., Ltd.), "Maxblend" (manufactured by Sumitomo Heavy Industries, Ltd.), "Supermix" (manufactured by Satake Chemical Machinery Co., Ltd.), and "Hi-F Mixer" (manufactured by Soken Chemical & Engineering Co., Ltd.).

[0042] (Process for removing organic volatile components) Volatile impurities such as unreacted polymerizable monomers and by-products present in the dispersion of toner particles obtained in the reaction step can be removed. The organic volatile component removal step can be carried out under normal pressure or reduced pressure, and various removal methods can be used that can remove the organic volatile components to a desired concentration.

[0043] (Washing process, solid-liquid separation process) To remove the dispersion stabilizer adhering to the toner particle surface, the toner particle dispersion is treated with an acid or alkali. After this, the polymer particles are separated from the liquid phase using a typical solid-liquid separation method, but to completely remove the acid or alkali and the dispersion stabilizer components dissolved therein, the toner particles are washed again with water. This washing process is repeated several times, and after sufficient washing, wet toner particles are obtained by solid-liquid separation again.

[0044] (drying process) The obtained wet toner particles are dried to remove the contained water, aqueous medium, etc. As a drying method generally used in the drying step, various drying methods such as vacuum drying, fluidized bed drying, air flow drying, etc. can be used.

[0045] (Classification process) After drying, the toner particles are classified using an air classifier or the like to obtain the desired particle size distribution.

[0046] (External addition process) Toner can be obtained by mixing external additives with toner particles for the purpose of imparting various properties to the toner particles.

[0047] [Components Constituting Toner Particles] Each component constituting the toner particles will be described in more detail below.

[0048] <Polymerizable monomer> The polymerizable monomer, which is also a component of the binder resin described below and is preferably used in the toner of the present invention, includes a vinyl polymerizable monomer capable of radical polymerization. As the vinyl polymerizable monomer, a monofunctional or polyfunctional one can be used. Examples of the monofunctional polymerizable monomer include the following.

[0049] 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, and p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl 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, and dibutyl phosphate ethyl acrylate. acrylate, acrylic monomers such as 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl 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; methylene aliphatic monocarboxylic acid esters, vinyl esters such as 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.

[0050] <Coloring agent> The colorants preferably used in the present invention include the following organic pigments or dyes and inorganic pigments.

[0051] As the organic pigment or organic dye as a cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds can be used.

[0052] Specific examples include: CI Pigment Blue 1, CI Pigment Blue 7, CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Blue 60, CI Pigment Blue 62, and CI Pigment Blue 66.

[0053] Examples of organic pigments or organic dyes as magenta colorants include the following: condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

[0054] Specific examples include the following: CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Violet 19, CI Pigment Red 23, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 57:1, CI Pigment Red 81:1, CI Pigment Red 122, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 150, CI Pigment Red 166, CI Pigment Red 169, CI Pigment Red 177, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 220, CI Pigment Red 221, and CI Pigment Red 254.

[0055] As the organic pigment or organic dye as a yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used.

[0056] Specific examples include the following: CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 17, CI Pigment Yellow 62, CI Pigment Yellow 74, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 111, and CI Pigment Yellow 12. 0, CI Pigment Yellow 127, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 147, CI Pigment Yellow 151, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 168, CI Pigment Yellow 174, CI Pigment Yellow 175, CI Pigment Yellow 176, CI Pigment Yellow 180, CI Pigment Yellow 181, CI Pigment Yellow 191, CI Pigment Yellow 194.

[0057] As the black colorant, carbon black and those toned to black using the above yellow / magenta / cyan colorants are used.

[0058] These colorants can be used alone or in a mixture, or in the form of a solid solution. The colorant used in the toner of the present invention is selected in consideration of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

[0059] The colorant is preferably added in an amount of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the binder resin.

[0060] A magnetic material may also be contained as a colorant, and examples of the magnetic material include magnetic iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel; alloys of these metals with metals such as aluminum, copper, magnesium, tin, zinc, beryllium, calcium, manganese, selenium, titanium, tungsten, and vanadium; and mixtures thereof.

[0061] The content or amount of the magnetic material added is preferably 20 parts by mass or more and 100 parts by mass or less, and more preferably 25 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the binder resin or the polymerizable monomer capable of forming the binder resin.

[0062] <Release agent> As the releasing agent used in the present invention, wax in a solid state at room temperature is preferable in terms of blocking resistance, durability for multiple sheets, low-temperature fixability, and offset resistance of the toner.

[0063] Examples of waxes include paraffin wax, polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer-Tropsch wax, amide wax, higher fatty acid, long-chain alcohol, ester wax, graft compounds thereof, and block compounds thereof.

[0064] <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 to a negative charge: Organometallic compounds and chelate compounds are effective, as are 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 bisphenols. Further examples include: urea derivatives, metal-containing salicylic acid compounds, calixarenes, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic-sulfonic acid copolymers, and non-metallic carboxylic acid compounds.

[0065] Examples of agents that control the positive charge of toner include the following: nigrosine and its modifications with 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 (lacquering agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and ferrocyanide); and metal salts of higher fatty acids.

[0066] 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, per 100 parts by mass of the polymerizable monomer.

[0067] <Polymerization initiator> As the polymerization initiator that can be used in the present invention, various types such as peroxide-based polymerization initiators and azo-based polymerization initiators can be used.

[0068] Examples of organic peroxide polymerization initiators include peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyketals, ketone peroxides, hydroperoxides, and diacyl peroxides.

[0069] Specific examples of organic peroxide polymerization initiators include peroxyesters such as t-butyl peroxyacetate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-hexyl peroxyacetate, t-hexyl peroxypivalate, t-hexyl peroxyisobutyrate, t-butyl peroxyisopropyl monocarbonate, and t-butyl peroxy 2-ethylhexyl monocarbonate; Examples include diacyl peroxides such as benzoyl peroxide; peroxydicarbonates such as diisopropyl peroxydicarbonate; peroxyketals such as 1,1-di-t-hexylperoxycyclohexane; dialkyl peroxides such as di-t-butyl peroxide; and others such as t-butylperoxyallyl monocarbonate.

[0070] Examples of inorganic peroxide polymerization initiators include persulfates and hydrogen peroxide.

[0071] Examples of azo polymerization initiators include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, and dimethyl-2,2'-azobis(2-methylpropionate).

[0072] In the present invention, an organic peroxide polymerization initiator, typically t-butyl peroxypivalate, can be preferably used in terms of polymerization efficiency.

[0073] If necessary, two or more of these polymerization initiators can be used simultaneously.

[0074] The amount of the polymerization initiator used is preferably 0.10 parts by mass or more and 20.0 parts by mass or less relative to 100.0 parts by mass of the polymerizable monomer.

[0075] <Crosslinking agent> Various crosslinking agents can also be used in the present invention, including the following: 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.

[0076] <Binder resin> The binder resin used in the present invention is not particularly limited and can be appropriately selected from known binder resins. Examples of the binder resin 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.

[0077] Examples of the polymer of styrene or a substitution product thereof include polystyrene, poly-p-chlorostyrene, polyvinyltoluene, etc. Examples of the styrene copolymer 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-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc.

[0078] 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, polypropylene resin, etc. These may be used alone or in combination of two or more.

[0079] <External additives> The toner of the present invention may contain external additives as needed, such as resin particles or inorganic particles that function as a charge adjuvant, a conductivity imparting agent, a fluidity imparting agent, an anti-caking agent, a release agent during heat roller fixing, a lubricant, or an abrasive.

[0080] Examples of the lubricant include polyethylene fluoride powder and polyvinylidene fluoride powder. Examples of the abrasive include cerium oxide powder, silicon carbide powder, and strontium titanate powder.

[0081] [Methods for measuring each physical property] Next, the methods for measuring various physical properties, including the characteristics that are evaluated in the examples, will be described.

[0082] <Method for measuring weight-average particle size (D4), number-average particle size (D1) and particle size distribution (D4 / D1) of toner particles> The weight-average particle size (D4) and number-average particle size (D1) of the toner are calculated as follows. The measurement device used is a precision particle size distribution measurement device using the narrow-pore electrical resistance method, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software, the Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.). The measurement is performed using an effective number of measurement channels of 25,000.

[0083] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter).

[0084] Before measurements and analyses were carried out, the dedicated software was set up as follows.

[0085] On the "Change Standard Measurement Method (SOMME)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particles 10.0 μm" (Beckman Coulter). Press the "Threshold / Noise Level Measurement Button" to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

[0086] On the "Pulse to particle size conversion setting" screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set to 2 μm to 60 μm.

[0087] The specific measurement method is as follows. (1) Pour approximately 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Approximately 30 ml of the above-mentioned aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a dilution of Contaminon N (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted approximately three times by mass with ion-exchanged water is added as a dispersant. (3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees. Place approximately 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add approximately 2 mL of Contaminon N to this water tank. (4) Set the beaker (2) in the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C. (6) Using a pipette, add the electrolyte solution (5) containing the dispersed toner to the round-bottom beaker (1) placed in the sample stand, and adjust the measurement concentration to approximately 5%. Then, measure the particle count until it reaches 50,000 particles. (7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight average particle size (D4) and number average particle size (D1). When the dedicated software is set to Graph / Volume %, the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen is the weight average particle size (D4), and when the dedicated software is set to Graph / Number %, the "Average Diameter" on the "Analysis / Number Statistics (Arithmetic Mean)" screen is the number average particle size (D1). D4 / D1 is the particle size distribution.

[0088] <Method for measuring the amount of coarse particles> 500 g of a slurry liquid having a toner particle solid content ratio of 20% is prepared.

[0089] The above slurry liquid was passed through a mesh of NXX7 (NBC Meshtec Co., Ltd.) with an opening of 200 μm, and the toner particles remaining on the filter were thoroughly dried, and then the measured mass (g) was taken as the amount of coarse particles.

[0090] <Number-average particle size and number concentration of fine bubbles> The number-average particle size and number concentration of fine bubbles are measured as follows using a particle size measuring device, ViewSizer 3000 (manufactured by HORIBA), which utilizes the particle tracking method.

[0091] An aqueous medium containing fine bubbles is prepared as a sample.

[0092] 2 ml of the measurement sample is poured into a quartz cell (High Precision Cell: manufactured by Hellma Analytic, 10 x 10 mm) equipped with a stir bar and dedicated jig included with the device, and the cell is set in the cell holder of the device. Launch Nano tracking analysis from the application provided with the device and perform measurements with the following settings. Target temperature: 22 #of videos:30 Frames per second: 30 Exposure: 18 Gain:24 Stirring time:5 Video length:300 Laser power B:70 G:12 R:8

[0093] After the measurement is completed, the Average size value (nm) on the displayed measurement results screen is the number-average particle size of the fine bubbles, and the Particle Concentration value (particles / mL) is the number concentration of the fine bubbles.

[0094] When measuring, turn stirring on in Streaming mode and check that the outlines of the fine bubbles on the image displayed are clear, and with stirring off, check that there is little overlap between the fine bubbles on the image. If the outlines are unclear, use the Focus function to adjust the focus. If there is significant overlap between the fine bubbles, dilute the sample. If the sample is diluted, multiply the obtained Particle Concentration value by the dilution factor to obtain the fine bubble number concentration.

[0095] [Configurations included in the embodiments of the present invention] The disclosure of this embodiment includes the following configuration. (Configuration 1) A method for producing a toner, comprising a particle forming step in which resin particles are formed in an aqueous medium while bubbles are generated, the aqueous medium is an aqueous medium containing fine bubbles, The number-average particle size of the fine bubbles is 1.0 x 10 1 nm or more 1.0×10 5 nm or less, and the number concentration of the fine bubbles is 1.00 × 10 5 1. A method for producing a toner, wherein the toner concentration is 1 / mL or more. (Configuration 2) The method for producing a toner according to Configuration 1, wherein the particle formation step is a step of forming resin particles by polymerizing polymerizable monomers in droplet particles dispersed in an aqueous medium using a polymerization initiator, and the bubbles generated are due to gas generated by cleavage of the polymerization initiator. (Configuration 3) The method for producing a toner according to Configuration 1, wherein the particle formation step is carried out while stirring an aqueous medium, and the bubbles are generated as a result of the stirring. (Configuration 4) When the agitator discharge rate in the particle formation step is Q (L / min), the total amount of the aqueous medium is V (L), and the temperature of the aqueous medium is T (°C), the following relational expression (1) is satisfied: T<500×Q / V+30...Formula (1) 4. The method for producing a toner according to any one of Configurations 1 to 3, which satisfies the above. (Configuration 5) When the number concentration of the fine bubbles is A (number / mL) and the number average particle diameter of the fine bubbles is B (nm), the following relational expression (2) is satisfied: A / B>1.0×10 3 ...Equation (2) 5. The method for producing a toner according to any one of Configurations 1 to 4, which satisfies the above. (Configuration 6) The particle forming step is a step of forming resin particles by polymerizing polymerizable monomers in droplet particles dispersed in an aqueous medium using a polymerization initiator, 6. The method for producing a toner according to any one of Configurations 1 to 5, further comprising a step of increasing the temperature after adding a polymerization initiator, wherein the temperature is increased at a rate of 0.3° C. / min or less in the temperature increasing step. [Example]

[0096] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Parts used in the examples are by weight unless otherwise specified.

[0097] <Example of manufacturing ion-exchanged water containing fine bubbles> (Production of ion-exchanged water 1) Ion-exchanged water was prepared and passed through a fine bubble generator, UP0290M 100V motor type (Shibata Co., Ltd.), to produce ion-exchanged water 1 containing fine bubbles. The number-average particle size and number concentration of the produced fine bubbles were 1.5 × 10 2 nm, 1.70 × 10 6 The number was 1 / mL.

[0098] (Production of ion-exchanged water 2) Fine bubble-containing ion-exchanged water 2 was prepared by diluting ultra-fine air bubble (nanobubble) water (Nanox Co., Ltd.) with 5000 times the amount of ion-exchanged water. The number-average particle size and number concentration of the fine bubbles prepared were 5.5 × 10 1 nm, 1.68 × 10 6 The number was 1 / mL.

[0099] (Production of ion-exchanged water 3) Ion-exchanged water was prepared and passed through a fine bubble generator, UP0290M 100V motor type (manufactured by Shibata Co., Ltd.), to obtain ion-exchanged water containing fine bubbles. Furthermore, the ion-exchanged water containing fine bubbles was passed through a 500 nm pore filter (manufactured by SGP Techno Co., Ltd.). After sufficient permeation, the aqueous medium before passing through the filter was collected, yielding ion-exchanged water 3 containing fine bubbles. The number-average particle size and number concentration of the fine bubbles produced were 9.1 x 10 2 nm, 1.48 × 10 6 The number was 1 / mL.

[0100] (Production of ion-exchanged water 4) Ion-exchanged water was prepared, and a pipe equipped with an SGP membrane filter (manufactured by SGP Techno Co., Ltd.) with a pore size of 10 μm was placed inside the ion-exchanged water. Air was then introduced into the pipe at a pressure of 0.2 MPa to produce ion-exchanged water 4 containing fine bubbles. The number-average particle size and number concentration of the produced fine bubbles were 8.5 × 10 3 nm, 1.18 × 10 5The number was 1 / mL.

[0101] (Production of ion-exchanged water 5) Ion-exchanged water was prepared, and a pipe equipped with an SGP membrane filter (manufactured by SGP Techno Co., Ltd.) with a pore size of 100 μm was placed inside the ion-exchanged water. Air was then introduced into the pipe at a pressure of 0.2 MPa to produce ion-exchanged water 5 containing fine bubbles. The number-average particle size and number concentration of the produced fine bubbles were 9.2 × 10 4 nm, 1.29 × 10 5 The number was 1 / mL.

[0102] (Production of ion-exchanged water 6) Fine bubble-containing ion-exchanged water 1 was diluted 15 times with ion-exchanged water to produce fine bubble-containing ion-exchanged water 6. The number-average particle size and number concentration of the produced fine bubbles were 1.5 x 10 2 nm, 1.13 × 10 5 The number was 1 / mL.

[0103] (Production of ion-exchanged water 7) Ion-exchanged water was prepared, and a pipe equipped with an SGP membrane filter (manufactured by SGP Techno Co., Ltd.) with a pore size of 200 μm was placed inside the ion-exchanged water. Air was then introduced into the pipe at a pressure of 0.2 MPa to produce ion-exchanged water 7 containing fine bubbles. The number-average particle size and number concentration of the produced fine bubbles were 1.6 × 10 5 nm, 1.29 × 10 5 The number was 1 / mL.

[0104] (Production of ion-exchanged water 8) Fine bubble-containing ion-exchanged water 1 was diluted 30 times with ion-exchanged water to produce fine bubble-containing ion-exchanged water 8. The number-average particle size and number concentration of the produced fine bubbles were 1.5 x 10 2 nm, 5.67 × 10 4 The number was 1 / mL.

[0105] <Preparation of Toner Particles 1 (Example 1)> (Preparation of aqueous medium containing dispersion stabilizer) A vessel equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube was charged with 100.00 parts of fine bubble-containing ion-exchanged water 1, 2.00 parts of sodium phosphate, and 0.90 parts of 10% by mass hydrochloric acid to prepare a sodium phosphate aqueous solution, which was then heated to 50°C. A calcium chloride aqueous solution prepared by dissolving 1.2 parts of calcium chloride hexahydrate in 8.20 parts of fine bubble-containing ion-exchanged water 1 was added to the vessel, and the mixture was stirred at a peripheral speed of 8000 rpm for 30 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). This produced an aqueous medium containing calcium phosphate (fine particles) as a dispersion stabilizer.

[0106] (Preparation of Pigment Dispersion Composition) Polymerizable monomer: styrene 39.00 parts Colorant: Carbon black (manufactured by Orion Engineered Carbons, trade name "Printex 35") 6.50 parts Charge control agent (Orient Co., Ltd.: Bontron E-89) 0.25 parts The above materials were placed in an Attritor disperser (Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5 hours to obtain a pigment dispersion composition.

[0107] (Preparation step of polymerizable monomer composition) The following materials were placed in a container and mixed and dispersed at 5000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a polymerizable monomer composition. 45.00 parts of the above pigment dispersion composition Polymerizable monomer: styrene 33.00 parts Polymerizable monomer: n-butyl acrylate 28.00 parts Polar resin 10.00 parts (A saturated polyester resin obtained by the condensation polymerization reaction of 2 moles of propylene oxide adduct of bisphenol A with terephthalic acid and isophthalic acid; weight average molecular weight: 13,000, acid value: 8 mgKOH / g, glass transition temperature: 74°C) Fischer-Tropsch wax 9.00 parts (Schumann Sasol, product name "C80": melting point 83.0°C)

[0108] (granulation process) The polymerizable monomer composition was added to a vessel containing the aqueous medium containing calcium phosphate (fine particles) prepared in the preparation of the aqueous medium containing a dispersion stabilizer, and granulation was carried out by stirring at 8000 rpm for 5 minutes in a TK homomixer while maintaining the temperature at 65°C. To this, 7.50 parts of the polymerization initiator t-butyl peroxypivalate (10-hour half-life temperature: 58°C) was added, and stirring was continued for another 1 minute.

[0109] (Reaction step) The mixture was then transferred to a reaction tank (glass separable flask, capacity 2 L) and heated to 70°C while stirring at 75 rpm with a paddle stirring blade during the polymerization process. The temperature rise rate was 0.25°C / min. When checking the inside of the reaction tank after the temperature rise, it was confirmed that the bubbles that had formed were significantly decreasing.

[0110] After the temperature was raised, stirring was continued for another 4 hours. After the polymerization reaction was completed, a dispersion of toner particles 1 was obtained.

[0111] After performing the above operation 10 times in succession, the mass of the reaction tank vessel that was assumed to have the greatest amount of scale adhesion in the particle formation process of this example was measured, and the amount of adhesion was calculated from the difference from the mass measured before production. Table 1 also shows the temperature T (°C) of the aqueous medium, and Q / V, which is the ratio of the agitator discharge rate Q (L / min) to the total amount V (L) of the aqueous medium.

[0112] Table 2 shows the amount of scale (g) adhering to the reaction tank during the production of toner particle 1, the particle size distribution of the toner particles obtained after the polymerization reaction (D4 / D1; average value of 10 runs), and the amount of coarse particles of the toner particles obtained after the polymerization reaction (average value of 10 runs).

[0113] <Preparation of Toner Particles 2 to 5 and 7 to 13 (Examples 2 to 5 and Examples 7 to 13)> Toner particles 2 to 5 and 7 to 13 were obtained in the same manner as toner particle 1, except for changing the type of ion-exchanged water and the reaction tank conditions shown in Table 1. Table 2 shows the amount of scale (g) adhering to the inside of the reaction tank during the production of these toner particles, the particle size distribution (10-day average value) of the toner particles obtained after the reaction was completed, and the amount of coarse particles (10-day average value) of the toner particles obtained after the reaction was completed.

[0114] <Preparation of Toner Particles 6 (Example 6)> "Synthesis of polyester resin 1" Bisphenol A ethylene oxide 2 mole adduct 8 mol parts Bisphenol A propylene oxide 2 mole adduct 85 mol parts Terephthalic acid 45 mol parts Fumaric acid 28 mol parts Dodecenyl succinic acid 24 mol parts The above monomers were charged into a vessel equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube, and the temperature was raised to 195°C over one hour. It was confirmed that the reaction system was uniformly stirred. 1.0 part of tin distearate was added to 100 parts of the monomers. The temperature was then raised from 195°C to 250°C over five hours while distilling off the resulting water, and the dehydration condensation reaction was carried out at 250°C for an additional two hours.

[0115] As a result, polyester resin 1 having a glass transition temperature of 59.3°C, an acid value of 15.3 mgKOH / g, a hydroxyl value of 26.3 mgKOH / g, a weight average molecular weight of 9,800, and a number average molecular weight of 3,800 was obtained.

[0116] "Synthesis of polyester resin 2" Bisphenol A-ethylene oxide 2 mole adduct 42 mol parts Bisphenol A-propylene oxide 2 mole adduct 42 mole parts Terephthalic acid 69 mol parts Dodecenyl succinic acid 30 mol parts The above monomers were added to a vessel equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube, and the temperature was raised to 195°C over one hour. It was confirmed that the reaction system was uniformly stirred. 0.7 parts of tin distearate were added to 100 parts of these monomers. The temperature was then raised from 195°C to 240°C over five hours while distilling off the resulting water, and a dehydration condensation reaction was carried out at 240°C for another two hours. The temperature was then lowered to 190°C, and 5 mol parts of trimellitic anhydride were gradually added, and the reaction was continued at 190°C for one hour.

[0117] As a result, polyester resin 2 having a glass transition temperature of 55.8°C, an acid value of 13.3 mgKOH / g, a hydroxyl value of 22.1 mgKOH / g, a weight average molecular weight of 41,500, and a number average molecular weight of 5,700 was obtained.

[0118] "Preparation of Resin Particle Dispersion 1" 100 parts polyester resin 50 parts methyl ethyl ketone 20 parts isopropyl alcohol Methyl ethyl ketone and isopropyl alcohol were added to the container. Then, the resin 1 was gradually added and stirred until completely dissolved, yielding a polyester resin 1 solution. The container containing the polyester resin 1 solution was set to 65°C, and while stirring, 10% aqueous ammonia was gradually added dropwise to a total of 5 parts, and then 230 parts of fine bubble-containing ion-exchanged water 1 was gradually added dropwise at a rate of 10 ml / min to cause phase inversion emulsification. The pressure was then reduced in an evaporator to remove the solvent, yielding a resin particle dispersion 1 of polyester resin 1. The volume average particle size of the resin particles was 133 nm. The resin particle solid content was adjusted to 20 mass% with ion-exchanged water 1.

[0119] "Preparation of resin particle dispersion 2" 100 parts polyester resin 2 50 parts methyl ethyl ketone 20 parts isopropyl alcohol Methyl ethyl ketone and isopropyl alcohol were added to the container. Then, the resin 2 was gradually added and stirred until completely dissolved, yielding a polyester resin 2 solution. The container containing the polyester resin 2 solution was set to 40°C, and while stirring, a 10% aqueous ammonia solution was gradually added dropwise to a total of 3.5 parts, followed by 230 parts of fine bubble-containing ion-exchanged water 1, which was gradually added dropwise at a rate of 10 ml / min to induce phase inversion emulsification. The pressure was further reduced to remove the solvent, yielding a resin particle dispersion 2 of polyester resin 2. The volume average particle size of the resin particles was 158 nm. The resin particle solid content was adjusted to 20% by mass with ion-exchanged water 1.

[0120] "Preparation of colorant particle dispersion" Copper phthalocyanine (pigment blue 15:3) 48 parts 5 parts of ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1,190 parts of fine bubble-containing ion-exchanged water The above components were mixed and dispersed for 10 minutes using a homogenizer (Ultra Turrax manufactured by IKA), and then dispersed for 20 minutes using an Ultimizer (opposed collision type wet grinder: manufactured by Sugino Machine Co., Ltd.) at a pressure of 250 MPa, to obtain a colorant particle dispersion liquid having a volume average particle size of 125 nm and a solid content of 20 mass %.

[0121] "Preparation of release agent particle dispersion" Release agent (hydrocarbon wax, melting point: 79°C) 13 parts 2 parts of ionic surfactant Neogen RK (Dai-ichi Kogyo Seiyaku Co., Ltd.) 1,240 parts of fine bubble-containing ion-exchanged water The above mixture was heated to 100°C and thoroughly dispersed using an IKA Ultra Turrax T50, and then heated to 115°C using a pressure discharge Gaulin homogenizer, where dispersion treatment was carried out for 1 hour, to obtain a release agent particle dispersion liquid with a volume average particle size of 155 nm and a solid content of 20 mass%.

[0122] "Production of Toner Particles 6 (Emulsion Aggregation)" ·Resin particle dispersion 1 500 parts ·Resin particle dispersion 2 400 parts Colorant particle dispersion 50 parts Release agent particle dispersion 80 parts First, in the core formation process, the above materials were charged into a reaction tank (glass separable flask, capacity 2 L) and mixed. Subsequently, the mixture was dispersed for 10 minutes at 5000 r / min using a homogenizer, Ultra Turrax T50 (manufactured by IKA). After adding a 1.0% aqueous nitric acid solution and adjusting the pH to 3.0, the mixture was heated to 65°C using a stirring blade in a heating water bath while adjusting the rotation speed to 3000 r / min so that the mixture was stirred. Observing the reaction tank after charging the raw materials into the tank confirmed the generation of bubbles. Furthermore, it was confirmed that the generated bubbles significantly decreased as the reaction tank was heated. The volume average particle size of the formed aggregated particles was appropriately confirmed, and when aggregated particles (cores) measuring 4.3 μm were formed, the following materials were charged into the shell formation process and stirred for 1 hour to form a shell. 1,300 parts of fine bubble-containing ion-exchanged water ·Resin particle dispersion 1 40 parts

[0123] Thereafter, the pH was adjusted to 9.0 using a 5% aqueous solution of sodium hydroxide, and the mixture was heated to 70° C. with continued stirring. When the desired surface shape was obtained, heating was stopped, and a toner particle dispersion was obtained.

[0124] After performing the above operation 10 times in succession, the mass of the reaction tank vessel that was expected to have the highest adhesion amount in the particle formation process of this example was measured, and the adhesion amount was calculated from the difference between this and the mass measured before production. Table 1 also shows the temperature T (°C) of the aqueous medium, and the ratio Q / V, which is the ratio of the agitator discharge rate Q (L / min) to the total volume V (L) of the aqueous medium.

[0125] Table 2 shows the amount of scale (g) adhering to the reaction tank during the production of toner particle 6, the particle size distribution of the toner particles obtained after the reaction (average value of 10 runs), and the amount of coarse particles of the toner particles obtained after the reaction (average value of 10 runs).

[0126] <Preparation of Comparative Toner Particles 1 to 3 (Comparative Examples 1 to 3)> Comparative toner particles 1 to 3 were obtained in the same manner as toner particles 1, except that the type of ion-exchanged water and the conditions of the reaction tank were changed as shown in Table 1. The "ion-exchanged water" for comparative toner particles 3 was the same as that prepared in the above-mentioned production example of fine bubble-containing ion-exchanged water.

[0127] The toner particles were transferred to a reaction tank, and after the temperature increase was completed, the bubbles in the reaction tank were visually checked, and it was confirmed that the amount of bubbles that had formed was increasing significantly. The amount of scale adhesion, the particle size distribution, and the amount of coarse particles during the production of these comparative toner particles are shown in Table 2.

[0128] <Preparation of Comparative Toner Particles 4 (Comparative Example 4)> Comparative toner particles 4 were obtained in the same manner as toner particles 6, except that the type of ion-exchanged water and the conditions of the reaction tank were changed as shown in Table 1. The "ion-exchanged water" for comparative toner particles 4 was the same as that prepared in the above-mentioned production example of fine bubble-containing ion-exchanged water.

[0129] The toner particles were transferred to a reaction tank, and after the temperature increase was completed, the bubbles in the reaction tank were visually checked, and it was confirmed that the amount of bubbles that had formed was increasing significantly. The amount of scale adhesion, the particle size distribution, and the amount of coarse particles during the production of comparative toner particle 4 are shown in Table 2.

[0130] [evaluation] Evaluation was made based on the values ​​obtained in Table 2, and the results were added to Table 2. The evaluation criteria are as follows:

[0131] <Evaluation criteria for adhesion amount> A: 3.0g or less B: More than 3.0g, less than 10.0g C: More than 10.0g, less than 15g.0 D: More than 15.0g, less than 20.0g E: More than 20.0g In this disclosure, a rating of C or higher was deemed to be an acceptable level.

[0132] <Evaluation criteria for particle size distribution> A: 1.15 or less B: More than 1.15, less than 1.25 C: More than 1.25, less than 1.35 D: over 1.35 In this disclosure, a rating of C or higher was deemed to be an acceptable level.

[0133] <Evaluation criteria for coarse particle content> A: 1.0g or less B: More than 1.0g, less than 5.0g C: More than 5.0g, less than 10.0g D: More than 10.0g In this disclosure, a rating of C or higher was deemed to be an acceptable level.

[0134] [Table 1]

[0135] [Table 2]

Claims

1. A toner manufacturing method including a particle forming step in which resin particles are formed in an aqueous medium while bubbles are generated, the aqueous medium is an aqueous medium containing fine bubbles, The number average particle size of the fine bubbles is 1.0 × 10 1 nm or more 1.0×10 5 nm or less, and the number concentration of the fine bubbles is 1.00 × 10 5 1. A method for producing a toner, wherein the toner concentration is 1 / mL or more.

2. 2. The method for producing a toner according to claim 1, wherein the particle forming step is a step of forming resin particles by polymerizing a polymerizable monomer in droplet particles dispersed in an aqueous medium using a polymerization initiator, and the bubbles generated are due to gas generated by cleavage of the polymerization initiator.

3. 2. The method for producing a toner according to claim 1, wherein the particle forming step is a step in which the aqueous medium is stirred, and the bubbles are generated as a result of the stirring.

4. The discharge rate of the agitator in the particle formation step is Q (L / min), the total amount of the aqueous medium is V (L), When the temperature of the aqueous medium is T (°C), the following relational expression (1) is satisfied: T<500×Q / V+30...Formula (1) The method for producing a toner according to claim 1 or 2, which satisfies the above condition.

5. When the number concentration of the fine bubbles is A (number / mL) and the number average particle diameter of the fine bubbles is B (nm), the following relational expression (2) is obtained: A / B>1.0×10 3 Formula (2) The method for producing a toner according to claim 1 or 2, which satisfies the above condition.

6. the particle formation step is a step of forming resin particles by polymerizing a polymerizable monomer in droplet particles dispersed in an aqueous medium using a polymerization initiator, 3. The method for producing a toner according to claim 1, further comprising a step of increasing the temperature after adding the polymerization initiator, wherein the temperature is increased at a rate of 0.3[deg.] C. / min or less in the step of increasing the temperature.

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