JP2004220005A - Method for finely pulverizing charge control agent for toner, and method for producing toner for electrostatic image development using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulverization method for producing fine particles of a charge control agent having a smaller particle diameter. Further, the present invention provides a method for finely pulverizing a charge control agent for producing fine particles of a charge control agent having a property of being uniformly dispersed on the particle surface of a toner without reaggregation even after fine pulverization. Further, the present invention provides a method for producing a toner for developing an electrostatic charge image using the pulverization method.
A method for finely pulverizing a charge control agent for a toner, the method comprising finely pulverizing the charge control agent by a mechanical pulverizer in the presence of inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g. A method of finely pulverizing a charge control agent for toner is used.
[Selection diagram] None

Description

  The present invention relates to a method for finely pulverizing a charge controlling agent used in a toner for developing an electrostatic image and a method for producing a toner for developing an electrostatic image using the method.

  In order to control the charging of the toner for developing an electrostatic image, a charge control agent such as an organic metal complex or an organic compound having a salt structure, or a resin having a polar group is usually used. The charge control agent exerts a charge control function of the toner by being contained in the toner, but in order to exert the function more effectively, the charge control agent must be uniformly dispersed in the toner particles. It is important that the dispersed particle size is smaller.

  Also, it is considered that the charge control agent works more effectively when it is present on the surface of the toner particles than in the toner particles. A fixing method has been proposed. Also in that method, it is important that the charge control agent having a smaller particle diameter is uniformly dispersed on the surface of the toner particles to impart an appropriate charge to the toner and maintain the charge for a long period of time.

  Conventionally, various studies have been made on a method of forming the charge control agent into fine particles and uniformly fixing the charge control agent on the toner surface. For example, Japanese Patent Application Laid-Open No. 5-127423 discloses an example in which a charge control agent is wet-pulverized using a sand mill in the presence of an organic solvent, dried, and then fixed together with inorganic fine particles to the surface of the base particles of the toner. Have been. Although the BET specific surface area of the finely dispersed charge control agent fine particles is also described, this measurement method serves as an index of the particle size of the primary particles, but cannot determine the presence or absence of aggregation. In order to fix the toner uniformly on the toner surface, the most important issue is how to prevent the charge controlling agent from being dispersed, that is, how to prevent aggregation.

  However, the publication does not describe the degree of aggregation of the charge control agent fine particles, and according to the technology disclosed in the publication, the finely pulverized charge control agent aggregates before being fixed to the surface of the base particles of the toner. Even though fineness has been achieved, it has already been aggregated during drying, so it is difficult to fix the particles uniformly with a smaller particle size, and the charging characteristics of the toner manufactured by the same method are sufficiently satisfactory. It was not something.

JP-A-5-127423 (Paragraph 63, Paragraph 64, Example 1)

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fine pulverizing method for producing fine particles of a charge control agent having a smaller particle diameter. Another object of the present invention is to provide a method of pulverizing a charge control agent for producing charge control agent fine particles having a property of being uniformly dispersed on the particle surface of a toner without reaggregation even after pulverization. Is to do. Still another object of the present invention is to provide a method for producing a toner for developing an electrostatic image using the fine pulverization method.

As a result of intensive studies, the present inventors have found a method of pulverizing a charge control agent for toner that can solve the above-mentioned problems, and have completed the present invention. That is, the present invention relates to a method for finely pulverizing a charge control agent for a toner, the method comprising finely pulverizing the charge control agent with a mechanical pulverizer in the presence of inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g. And a method for finely pulverizing a charge control agent for toner.

  Further, the present invention also provides a colored dispersion obtained by dissolving or dispersing a colorant and a binder resin containing a carboxyl group in an organic solvent in an aqueous medium in the presence of a basic compound. Emulsification step of forming fine particles (A) of the above, evaporation step of forming colored resin fine particles (B) by evaporating and removing the organic solvent in the fine particles (A), and removing the colored resin fine particles (B) from an aqueous medium. A separating and drying step of separating and drying, and a surface treatment step of fixing fine particles of the charge control agent containing the inorganic fine particles obtained by the above method on the surface of the colored resin fine particles (B) are sequentially performed. An object of the present invention is to provide a method for producing a toner for developing an electrostatic image.

The inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g used in the present invention are excellent in fluidity. Therefore, when the charge control agent is finely pulverized in the presence of the inorganic fine particles, the inorganic fine particles adhere or adhere to the charge control agent particles, and the fluidity of the charge control agent particles is improved. As a result, the charge control agent particles are easily crushed. In addition, since the inorganic fine particles adhere or adhere to the charge control agent fine particles after pulverization, the flowability of the charge control agent fine particles is improved, and the fixing to the surface of the base toner particles is performed uniformly. Can be. Further, it is possible to prevent the pulverized charge control agent fine particles from reaggregating, and to fix the fine particles to the surface of the base toner particles while maintaining the state of the fine particle diameter.

  According to the method for finely pulverizing the toner charge control agent of the present invention, the charge control agent fine particles having a smaller particle size, and having the property of being uniformly dispersed on the particle surface of the base toner without reaggregation even after the fine pulverization. Can be manufactured.

  In the present invention, a known charge control agent can be used. For example, as the positive charge control agent, a nigrosine dye, a modified nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt, a resin containing a quaternary ammonium group and / or an amino group, or the like can be used. As trimethylethane dyes, metal salts or complexes of salicylic acid, metal salts or complexes of benzylic acid, copper phthalocyanine, perylene, quinacridone, metal salts or complexes of azo compounds, calixarene-type phenolic condensates, cyclic polysaccharides, Resins containing a carboxyl group and / or a sulfonyl group can be used.

  Suitable positively chargeable charge control agents that can be used in the present invention include, for example, nigrosine dyes such as “NIGROSINE BASE EX”, “OIL BLACK BS”, “BONTRON N-01”, and “BONTRON N-07” (orient And the like, as modified nigrosine dyes, such as "BONTRON N-04", "BONTRON N-21" (above, Orient Chemical Co., Ltd.), "CHUO-3" (Chuo Gosei Chemical Co., Ltd.), etc. Is mentioned. Examples of triphenylmethane include "OIL BLUE" (Orient Chemical Co., Ltd.) and "COPY BLUE PR" (Clariant Co., Ltd.). As quaternary ammonium salts, "TP-415" (Hodogaya Chemical Co., Ltd.), "FCA201PS" (Fujikura Kasei Co., Ltd.), "PX-04", "COPY CHARGE PSY" (Clariant Japan Co., Ltd.) ) And the like. As negative charge control agents, “E-81”, “E-88”, “E-84” (orient Chemical Co., Ltd.), “TN-105” (Hodogaya Chemical Co., Ltd.), “LR” -147 "(Nippon Carlit Co., Ltd.).

The inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g used in the present invention are not particularly limited as long as the BET specific surface area is in the above range. For example, silicon dioxide, titanium oxide, aluminum oxide, oxide Surface treatment with inorganic fine powders such as cerium, zinc oxide, tin oxide, zirconium oxide, silicon carbide, boron carbide, titanium nitride, zirconium nitride, magnesium fluoride, etc. and their hydrophobic treatment agents such as silicone oil and silane coupling agent What was done is used.

  Among them, silicon dioxide (silica) whose surface has been hydrophobized with various polyorganosiloxanes, hexamethylene disilazane, silane coupling agents and the like can be particularly preferably used. As such, for example, there is one that is commercially available under the following trade names.

AEROSIL R972, R974, R202, R805, R812, RX200, RY200, R809, RX50, RA200HS, RA200H [Nippon Aerosil Co., Ltd.]
WACKER HDK H2000, H1018, H2050EP, HDK H3050EP, HVK2150 [Wacker Chemicals East Asia Co., Ltd.]
Nipsil SS-10, SS-15, SS-20, SS-50, SS-60, SS-100, SS-50B, SS-50F, SS-10F, SS-40, SS-70, SS-72F, [ Nippon Silica Industry Co., Ltd.]
CABOSIL TG820F, TS-530, TS-720 [Cabot Specialty Chemicals, Inc.]

The BET specific surface area, more preferably those wherein 30 to 150 m ² / g, it is particularly preferable in 40 to 100 m ² / g.

  The polarity of the inorganic compound with respect to the charge control agent used is preferably the same. Moreover, in order to control the charge control function of the charge control agent, an inorganic compound having a reverse polarity or a conductive inorganic compound may be used. Further, the inorganic fine particles used in the present invention preferably have higher hardness and higher specific gravity than the charge control agent used. When the charge control agent is used alone, it is soft and easily agglomerated even when a shearing force or a compressive force is applied, and it is difficult to perform uniform fine dispersion.

  As the mechanical pulverizer that can be used in the present invention, a pulverizer using media such as glass beads, stainless steel beads, and ceramic beads is preferable, and specific examples include a ball mill, a motor mill, a sand mill, and an SC mill. A high-pressure homogenizer can also be used. Examples of the stirring mixer include a Henschel mixer and a Q-type mixer.

  In the present invention, the charge controlling agent is finely pulverized by the pulverizer in the presence of the inorganic fine particles. In this case, it is preferable to mix the inorganic fine particles and the charge control agent in advance. The mixing ratio (mass ratio) at this time is preferably inorganic fine particles / charge control agent = 10/90 to 80/20. Further, the ratio is more preferably from 20/80 to 70/30, and particularly preferably from 20/80 to 50/50.

  When the inorganic fine particles and the charge control agent are mixed in advance, various mixers such as a Henschel mixer and a Nauter mixer can be used.

  Further, when pulverizing with a fine pulverizer using a medium, it is preferable to perform fine pulverization by a wet method. Among them, water is preferred. When dispersion is difficult using water as a medium, it is preferable to add an organic solvent or both. In addition, it is necessary to pay attention to the solubility of the charge control agent, and it is preferable to select a solvent having as low solubility as possible. It is preferable that the solvent to be selected is appropriately selected depending on the type of the charge controlling agent, while paying attention to the solubility. Organic solvents that can be used at that time include, for example, pentane, hexane, heptane, benzene, toluene, xylene, cyclohexane, hydrocarbons such as petroleum ether; methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, and carbon tetrachloride. Halogenated hydrocarbons; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; These solvents can be used as a mixture of two or more kinds. Among them, a water-soluble organic solvent is preferable, and isopropyl alcohol, methanol, ethanol, and acetone are more preferable.

  When a solvent such as water or an organic solvent is added and finely pulverized, the amount added is preferably from 10/90 to 40/60 in the ratio (mass) of the total mass of the inorganic fine particles and the charge controlling agent to the solvent. Further, the ratio is more preferably 20/80 to 30/70.

A particularly preferred embodiment of the pulverization method is a method in which inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g and a charge control agent are mixed in the above ratio, and water or an organic solvent or both are added in the above ratio. Finely pulverized by a mechanical pulverizer using (a first pulverizing step), then, water or an organic solvent is removed to separate a mixture of inorganic fine particles and a charge controlling agent fine particle (separating step), and dried. (Drying step), a method in which inorganic fine particles are further added to the dried mixture and finely pulverized with a stirring mixer such as a Henschel mixer (second pulverizing step). In this case, in the first pulverizing step, the mass ratio of the inorganic fine particles to the charge control agent is preferably 10/90 to 50/50, and the total mass of the inorganic fine particles to the charge control agent and the mass ratio of the solvent are 10/90 to 50/50. / 90 to 30/70. In the second pulverization step, the inorganic fine particles are added so that the final ratio of the inorganic fine particles to the charge control agent falls within the above-mentioned preferable range.

  As a method of separating a mixture of inorganic fine particles and charge control agent fine particles by removing water or an organic solvent, most of the solvent is distilled off under reduced pressure, or the solvent and the solid content are separated by a centrifuge or the like.・ It may be removed. Next, the solvent is removed by a freeze dryer, which is a commonly used dryer, or a mixed vacuum dryer.

  Thereafter, it is preferable to further pulverize the mixture of the inorganic fine particles and the fine particles of the charge controlling agent, which has been reaggregated in the drying step, by further adding inorganic fine particles in the second pulverizing step, and return to the original finely dispersed state. The amount of the inorganic compound added at this time is preferably 10 to 30% based on the total amount of the mixture of the inorganic fine particles and the fine particles of the charge control agent. In the present invention, the re-agglomerate can be easily pulverized in the drying step because it is a mixture of the inorganic fine particles and the fine particles of the charge controlling agent in advance. With the charge control agent alone, not only the fine dispersion in the wet method becomes insufficient, but also it is difficult to finely disperse the aggregates after drying, and the effect of the production method of the present invention is great.

According to the above-mentioned pulverization conditions, in the present invention, the charge control agent fine powder is produced. As a final particle size distribution, the volume particle size at the peak top is in the range of 0.5 to 2 μm, and the particles or the aggregates larger than 10 μm are obtained. It is preferable to appropriately set the conditions so that the volume particle size of the polymer is 3% or less, preferably 1% or less. Further, the BET specific surface area is preferably 15 to 50 m ² / g. As the particle size distribution of the charge control agent fine powder obtained by the production method of the present invention, the volume particle size at the peak top is measured by LS-910 manufactured by Horiba, Ltd. The volume particle size larger than 10 μm is measured with a Coulter Multisizer TAII type (aperture tube diameter: 100 μm).

  Base particles (hereinafter referred to as base toner) of a toner using the charge control agent fine powder manufactured by the above method can be manufactured by the following method. As the binder resin of the base toner, for example, polystyrene resin, styrene acrylic resin, or vinyl copolymer resin such as styrene butadiene resin, further, polyester resin, epoxy resin, butyral resin, xylene resin, cumarone indene resin Among them, vinyl copolymer resins and polyester resins are preferable, and polyester resins are particularly preferably used because they have a good balance of fixability, offset resistance, transparency and the like.

  The polyester resin is synthesized by dehydrating and condensing a polybasic acid and a polyhydric alcohol. Examples of polybasic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, and naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl succinic anhydride Aliphatic carboxylic acids such as acid and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; These polybasic acids can be used alone or in combination of two or more. Among these polybasic acids, it is preferable to use aromatic carboxylic acids.

  Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane, and pentaerythritol; cyclohexanediol, cyclohexanedicyclohexane Alicyclic diols such as methanol and hydrogenated bisphenol A; and aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. These polyhydric alcohols can be used alone or in combination of two or more. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

  In addition, a monocarboxylic acid and / or a monoalcohol are further added to the polyester resin obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol to esterify a hydroxyl group and / or a carboxyl group at the polymerization end. The acid value of the polyester resin can be adjusted. Examples of the monocarboxylic acid used for such a purpose include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, and propionic anhydride. Examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, trifluoroethanol, trichloroethanol, hexafluoroisopropanol, and phenol.

  The polyester resin can be produced by subjecting the above-mentioned polyhydric alcohol and polyvalent carboxylic acid to a condensation reaction according to a conventional method. For example, the polyhydric alcohol and the polyhydric carboxylic acid are blended in a thermometer, a stirrer, a reaction vessel equipped with a falling condenser, and heated at 150 to 250 ° C. in the presence of an inert gas such as nitrogen, The by-product low-molecular compound is continuously removed from the reaction system, and the reaction is stopped when a predetermined physical property value is reached, followed by cooling, whereby a target reactant can be obtained.

  The synthesis of such a polyester resin can also be performed by adding a catalyst. Examples of the esterification catalyst to be used include organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. When the carboxylic acid component used is a lower alkyl ester, a transesterification catalyst can be used. Examples of the transesterification catalyst include metal acetates such as zinc acetate, lead acetate, and magnesium acetate; metal oxides such as zinc oxide and antimony oxide; and metal alkoxides such as tetrabutyl titanate. The addition amount of the catalyst is preferably in the range of 0.01 to 1% by mass based on the total amount of the raw materials.

  In order to produce a branched or crosslinked polyester resin in such a polycondensation reaction, a polybasic acid having three or more carboxyl groups in one molecule or an anhydride thereof, and / or one molecule A polyhydric alcohol having three or more hydroxyl groups therein may be used as an essential synthesis raw material.

  The glass transition temperature (Tg) of the polyester resin is preferably 50 ° C. or higher, and among them, those having a Tg of 55 ° C. or higher are particularly preferable. When the Tg is 50 ° C. or lower, a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside a developing device of a machine.

  Further, the softening point of the polyester resin is preferably 90 ° C. or higher, more preferably 90 ° C. to 180 ° C., and more preferably 95 ° C. to 160 ° C. When the softening point is lower than 90 ° C., the toner is liable to cause agglomeration, and when storing or printing, trouble tends to occur.

  Further, when full color toner is required to have color reproducibility and transparency at the time of color superposition, the softening point of the resin is preferably in the range of 90 ° C. to 140 ° C., and more preferably 95 ° C. C. to 135.degree.

The softening point of the resin is defined as the T1 / 2 temperature measured using a flow tester CFT-500 manufactured by Shimadzu Corporation which is a constant load extrusion type thin tube rheometer. The measurement conditions of the flow tester were as follows: piston cross-sectional area 1 cm ² , cylinder pressure 0.98 MPa, die length 1 mm, die hole diameter 1 mm, measurement start temperature 50 ° C, heating rate 6 ° C / min, sample mass 1. This was performed under the condition of 5 g.

  Further, a release agent can be contained in the base toner. In this case, the release agent is selected from the group consisting of hydrocarbon waxes such as polypropylene wax, polyethylene wax and Fischer-Tropsch wax, synthetic ester waxes, carnauba wax, and natural ester waxes such as rice wax. A used release agent is used. Among them, natural ester waxes such as carnauba wax and rice wax, and synthetic ester waxes obtained from polyhydric alcohols and long-chain monocarboxylic acids are preferably used. As the synthetic ester wax, for example, WEP-5 (manufactured by NOF CORPORATION) is suitably used. If the content of the release agent is less than 1% by mass, the releasability tends to be insufficient, and if it exceeds 40% by mass, the wax is likely to be exposed on the surface of the toner particles, and the chargeability and storage stability deteriorate. For ease of use, the content is preferably in the range of 1 to 40% by mass.

  Further, a charge control agent may be contained inside the base toner particles. The charge control agent contained in the base toner particles is not particularly limited, but is preferably a compound of the same type as the charge control agent fixed to the surface of the base toner particles after the preparation of the base toner particles.

  The amount of the charge control agent contained in the base toner particles is preferably 0.01 to 10% by mass. In particular, it is preferably 0.1 to 6% by mass. Further, the dispersion diameter of the charge control agent in the base toner particles is preferably in the range of 0.5 to 0.01 μm. The range of 0.2 to 0.01 is more preferable. If it is larger than 0.5 μm, the dispersion of the charge controlling agent in the particles tends to be non-uniform, which adversely affects the charging characteristics, which is not preferable. On the other hand, when it is smaller than 0.01 μm, the function as a charge control agent becomes insufficient, which is not preferable.

  There is no particular limitation on the colorant used in producing the base toner, and a known and commonly used colorant is used. For example, as a black colorant, carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black classified according to the production method; I. Pigment Black 11, iron oxide pigments such as C.I. I. Pigment Black 12 and the like; iron-titanium composite oxide-based pigments; and blue-based colorants include phthalocyanine-based C.I. I. Pigment Blue 1,2,15: 1,15: 2,15: 3,15: 4,15: 6,15,16,17: 1,27,28,29,56,60,63 and the like. As a blue colorant, C.I. I. Pigment Blue 15: 3, 15, 16, 60, and most preferably C.I. I. Pigment Blue 15: 3,60.

  Examples of the yellow colorant include C.I. I. Pigment Yellow 1, 3, 4, 5, 6, 12, 13, 14, 15, 16, 17, 18, 24, 55, 65, 73, 74, 81, 83, 87, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 116, 117, 120, 123, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 156, 168, 169, 170, 171, 172, 173, 180, 185 and the like. Preferably, C.I. I. Pigment Yellow 17, 74, 93, 97, 110, 155, and 180, and more preferably C.I. I. Pigment Yellow 74, 93, 97, 180, and particularly C.I. I. Pigment Yellow 93, 97, 180 is preferred.

  Further, as a red colorant, for example, C.I. I. Pigment Red 1,2,3,4,5,6,7,8,9,10,12,14,15,17,18,22,23,31,37,38,41,42,48: 1 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58: 4, 60: 1. 63: 1, 63: 2, 64: 1, 65, 66, 67, 68, 81, 83, 88, 90, 90: 1, 112, 114, 115, 122, 123, 133, 144, 146, 147, 149,150,151,166,168,170,171,172,174,175,176,177,178,179,185,187,188,189,190,193,194,202,208,209,214, 216,220,221,224,2 42, 243, 243: 1, 245, 246, 247 and the like. Preferably, C.I. I. Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 53: 1, 57: 1, 122 and 209, and most preferably C.I. I. Pigment Red 57: 1, 122 and 209.

  The content of these colorants is preferably from 1 to 20% by mass based on the entire base toner. Among them, the content is more preferably 2 to 15% by mass, and particularly preferably 2 to 10% by mass. These colorants can be used alone or in combination of two or more.

  The method for producing the base toner particles is not particularly limited. For example, using a Henschel mixer, raw materials including a binder resin and a colorant are mixed, and the mixture is kneaded with a melt kneader. Thereafter, the kneaded material is pulverized and classified to obtain a base toner having a predetermined particle size. Such a conventional pulverization type manufacturing method can be used. The shape of the base toner produced by such a method is irregular. However, the spherical base toner produced by the following production method is more surface-treated with the charge control agent fine particles produced by the production method of the present invention than the amorphous base toner obtained by such a pulverization method. This is preferable because uniform processing can be performed.

  When a toner is manufactured using the charge control agent fine particles manufactured by the manufacturing method of the present invention, a preferable method of manufacturing a base toner is to dissolve or disperse a binder resin containing a carboxyl group and a coloring agent in an organic solvent. Emulsifying the colored dispersion thus obtained in an aqueous medium in the presence of a basic compound to form fine particles (A) of the colored dispersion, and evaporating and removing the organic solvent in the fine particles (A). In this method, a toner is produced through an evaporation step of forming colored resin fine particles (B), and a separation drying step of separating the colored resin fine particles (B) from an aqueous medium and drying. In this case, in addition to the binder resin and the colorant, a dispersing step may be performed by adding a release agent or a charge control agent, if necessary. Further, each raw material may be separately subjected to dispersion treatment.

  In addition, among the above production methods, a step of forming an aggregate of the fine particles by coalescing the fine particles (A) after the emulsification step or associating the colored resin fine particles (B) with each other is performed. It is preferable to adopt a method of producing a base toner by separating. According to such a production method, a spherical base toner having no emulsification loss, a sharp particle size distribution, and a curved surface can be obtained easily, in a short time, and with a high yield. Therefore, the charge control agent fine particles can be uniformly fixed to the particle surface, which is preferable.

  It should be noted that the method of producing the colored resin fine particles (B) by performing aggregation and coalescence of the organic solvent-containing fine particles (A) produced by emulsification and dispersion in a single step, and then removing the solvent, is a production method by "coalescence". The coalesced particles before solvent removal are referred to as "unified". Also, the colored resin fine particles (B) are produced by removing the organic solvent in the fine particles (A) produced by emulsification and dispersion, and then aggregated to produce an aggregate. Is referred to as a “association” manufacturing method, and an aggregate of the colored resin fine particles (B) is referred to as an “association”. As a method for producing the base toner, a production method based on “union” is particularly preferable.

Hereinafter, the manufacturing method by union and association will be described. The method for producing a parent toner by coalescence and association is as follows:
First step: a colored dispersion is prepared by dissolving or dispersing a binder resin having a carboxyl group and a colorant in an organic solvent, and then emulsifying the colored dispersion in an aqueous medium using a basic compound. Thereby forming fine particles (A) of the colored dispersion in the aqueous medium,
Second step: a step in which the fine particles (A) are coalesced to produce a unified body, and the organic solvent contained in the unified body is desolvated to produce colored resin fine particles (B); )), After which the organic solvent is removed, and the fine particles are associated with each other to produce an aggregate, thereby producing the colored resin fine particles (B). Third step: The colored resin fine particles (B) are separated from the aqueous medium and dried. , A process of manufacturing a base toner,
It consists of three steps.

  In the first step, a colored dispersion containing the binder resin, the colorant, and the organic solvent is prepared by charging and dissolving or dispersing the binder resin and the colorant in the organic solvent. In this case, if necessary, a release agent, a charge control agent, or other additives can be used together with a binder resin or the like.

  Examples of the organic solvent for dissolving or dispersing the binder resin and a coloring agent or a release agent to be added as needed include hydrocarbons such as pentane, hexane, heptane, benzene, toluene, xylene, cyclohexane, and petroleum ether. Halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, and carbon tetrachloride; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate. Used. These solvents can be used as a mixture of two or more, but it is preferable to use the same type of solvent alone from the viewpoint of solvent recovery. The organic solvent dissolves or disperses the binder resin, and preferably has a relatively low toxicity and a low boiling point, which is easy to remove the solvent in a later step. As such a solvent, methyl ethyl ketone is most preferable.

  Next, the mixture containing the binder resin and the organic solvent is emulsified in an aqueous medium. In this case, the colored dispersion prepared by the above method is mixed with an aqueous medium and emulsified in the presence of a basic neutralizing agent. In this step, a method in which an aqueous medium (water or a liquid medium containing water as a main component) is gradually added to a mixture of a binder resin, a coloring agent, and the like and an organic solvent is preferable. At that time, by gradually adding water to the organic continuous phase of the mixture, a discontinuous phase of Water in Oil is generated, and further adding water to add a discontinuous phase of Oil in Water. To form a suspension / emulsion in which the mixture is suspended as particles (droplets) in an aqueous medium (hereinafter, this method is referred to as phase inversion emulsification).

  In the phase inversion emulsification, water is added so that the ratio of water to the total amount of the organic solvent and the added water is 30 to 70%. It is more preferably 35 to 65%, and particularly preferably 40 to 60%. The aqueous medium used is preferably water, more preferably deionized water.

  The binder resin used in such a method is a binder resin containing a carboxyl group, and a binder resin that becomes self-water dispersible by neutralizing the carboxyl group (hereinafter, referred to as a self-water dispersible resin). The acid value of the self-water dispersible binder resin is preferably from 3 to 30, and more preferably from 3 to 20. A resin having self-water dispersibility becomes an anionic type by neutralizing a carboxyl group with a basic compound. As a result, the hydrophilicity of the resin increases, and the resin can be stably dispersed in an aqueous medium without using a dispersion stabilizer or a surfactant. The basic compound for neutralization is not particularly limited, and examples thereof include an inorganic base such as sodium hydroxide, potassium hydroxide, and ammonia, and an organic base such as diethylamine, triethylamine, and isopropylamine. Of these, inorganic bases such as ammonia, sodium hydroxide and potassium hydroxide are preferred.

  Examples of the method of neutralizing the carboxyl group of the binder resin with a base include (1) a method of producing a mixture containing a binder resin having a carboxyl group, an organic pigment, a wax and an organic solvent, and then neutralizing the mixture with a base; Alternatively, (2) a method in which a basic neutralizing agent is previously mixed in an aqueous medium and the acidic groups of the binder resin contained in the mixture are neutralized during phase inversion emulsification.

  The basic compound is used in an amount of 0.5 to 3 equivalents based on the total amount of the carboxyl groups of the binder resin. It is more preferable that the amount is more than 1 equivalent and not more than 2 equivalents. By adding in excess of the amount required to neutralize the carboxyl groups of the binder resin in this way, it is possible to prevent the formation of irregularly shaped particles, improve the sphericity of the base toner, and And the particle size distribution can be sharpened.

  The 50% volume average particle diameter of the fine particles (A) of the colored dispersion produced in the first step is in the range of more than 1 μm and 6 μm or less, more preferably more than 1 μm and 4 μm. When the thickness is 1 μm or less, when an organic pigment or a release agent is used, the encapsulation is not sufficiently performed by the binder resin, which adversely affects the charging characteristics and the developing characteristics, which is not preferable. When the particle size is large, the particle size of the obtained base toner is limited. Therefore, it is necessary to make the particle size smaller than the target particle size. However, when the particle size is larger than 6 μm, coarse particles are easily generated. Therefore, it is not preferable. In the particle size distribution of the fine particles (A) produced in the first step, the ratio of the volume particle size of 10 μm or more is 2% or less, more preferably 1% or less, and the ratio of the volume particle size of 5 μm or more is 10%. Or less, more preferably 6% or less.

  In the second step, the fine particles (A) obtained in the first step are coalesced or associated to form a united or aggregated body of the fine particles (A), thereby forming base toner particles having a desired particle size. . The production method by the coalescence method and the production method by the association method will be sequentially described.

  In the coalescence method, the dispersion of the fine particles (A) obtained in the first step is diluted with water to adjust the amount of the solvent. Thereafter, a dispersion stabilizer is added, and an aqueous solution of an electrolyte is dropped in the presence of the dispersion stabilizer to promote coalescence, thereby obtaining an aggregate having a predetermined particle size.

  The fine particles (A) obtained in the first step are stably dispersed in the aqueous medium by the action of the electric double layer by the carboxylate. In the second step, the particles are destabilized by adding an electrolyte that breaks or reduces the electric double layer to the aqueous medium in which the fine particles (A) are dispersed. Examples of the electrolyte include acidic substances such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and oxalic acid. In addition, organic and inorganic water-soluble salts such as sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and sodium acetate are also included. It can be used effectively as an electrolyte. These electrolytes may be used alone or as a mixture of two or more substances. Of these, sulfates of monovalent cations such as sodium sulfate and ammonium sulfate are preferred for promoting uniform coalescence.

  By the way, the addition of an electrolyte or the like alone makes the dispersion stability of the fine particles (A) in the system unstable, so that the coalescence becomes uneven and coarse particles and aggregates are generated. In order to prevent the aggregates of the fine particles (A) generated by the electrolyte or the acidic substance from repeating reunion and forming an aggregate having a target particle diameter or more, it is necessary to add an electrolyte or the like before the addition. It is necessary to add an inorganic dispersion stabilizer such as hydroxyapatite or an ionic or nonionic surfactant as a dispersion stabilizer. The dispersion stabilizer to be used needs to have characteristics capable of maintaining dispersion stability even in the presence of an electrolyte to be added later. Examples of dispersion stabilizers having such properties include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester And nonionic emulsifiers such as polyoxyethylene sorbitan fatty acid esters or various pluronics, anionic emulsifiers such as alkyl sulfate salts, and cationic dispersion stabilizers such as quaternary ammonium salts. Above all, even if a small amount of the anionic or nonionic dispersion stabilizer is added, the dispersion stability of the system can be effectively controlled, which is preferable. The cloud point of the nonionic surfactant is preferably 40 ° C. or higher. The surfactants described above may be used alone or as a mixture of two or more. By adding an electrolyte in the presence of a dispersion stabilizer (emulsifier), non-uniform coalescence can be prevented, resulting in a sharp particle size distribution and, consequently, improved yield. Is done.

  In the case of manufacturing a united product, it is preferable to further dilute the dispersion of the fine particles (A) obtained by the phase inversion emulsification in the first step with water. Thereafter, a dispersion stabilizer and an electrolyte are sequentially added to perform coalescence. Alternatively, it is preferable to adjust the amount of the solvent in the dispersion by adding an aqueous solution of a dispersion stabilizer and / or an electrolyte to obtain particles having a predetermined particle size. The amount of the solvent contained in the system before adding the electrolyte is preferably in the range of 15 to 45% by mass. Further, it is more preferably in the range of 20 to 40% by mass, and particularly preferably in the range of 25 to 40% by mass. If the amount of the solvent is less than 15% by mass, the mass of the electrolyte required for coalescence increases, which is not preferable. On the other hand, if the amount of the solvent is more than 45% by mass, the generation of aggregates due to non-uniform coalescence increases, and the addition amount of the dispersion stabilizer increases, which is not preferable.

  The shape of the toner particles after coalescence can be controlled by adjusting the amount of the solvent. When the amount of the solvent is in the range of 25 to 45% by mass, the degree of swelling of the fine particles by the solvent is large, so that spherical to substantially spherical particles can be easily obtained by coalescence. On the other hand, when the amount of the solvent is in the range of 15 to 25% by mass, the degree of swelling of the fine particles by the solvent is small, so that irregularly-shaped or substantially spherical toner particles are easily obtained.

  The amount of the dispersion stabilizer used is preferably, for example, in the range of 0.5 to 3.0% by mass based on the solid content of the fine particles. It is more preferably in the range of 0.5 to 2.5% by mass, particularly preferably in the range of 0.8 to 2.5% by mass. If the amount is less than 0.5% by mass, the desired effect of preventing the generation of coarse particles cannot be obtained. On the other hand, if the content is more than 3.0% by mass, coalescence does not sufficiently proceed even if the amount of the electrolyte is increased, and particles having a predetermined particle size cannot be obtained. Is not preferred because it reduces the

  The amount of the electrolyte is preferably in the range of 0.5 to 15% by mass based on the solid content of the fine particles (A). It is more preferably in the range of 1 to 12% by mass, particularly preferably in the range of 1 to 10% by mass. If the amount of the electrolyte is less than 0.5% by mass, coalescence does not proceed sufficiently, which is not preferable. On the other hand, if the amount of the electrolyte is more than 15% by mass, the coalescence becomes non-uniform, and aggregates are generated and coarse particles are generated, which is not preferable because the yield is reduced.

  The temperature at the time of joining is preferably in the range of 10 to 50 ° C. It is more preferably in the range of 20 to 40C, and particularly preferably 20 to 35C. If the temperature is lower than 10 ° C., coalescence hardly proceeds, which is not preferable. On the other hand, if the temperature is higher than 50 ° C., the coalescence rate is increased, and aggregates and coarse particles are easily generated, which is not preferable. In the production method of the present invention, it is possible to form an aggregate by coalescence under a low temperature condition of, for example, 20 to 40 ° C.

  The integrated shape obtained in the second step can be changed from an irregular shape whose surface is covered with a curved surface to a spherical shape depending on the degree of union. The average circularity can also be determined by taking an SEM (scanning electron microscope) photograph of the finally obtained base toner particles, measuring and calculating the same, and a flow method manufactured by Toa Medical Electronics Co., Ltd. It can be easily measured by using the particle image analyzer FPIP-1000.

  When the shape of the base toner particles is a substantially spherical shape or a spherical shape having an average circularity of 0.97 or more covered with a curved surface, improvement in powder fluidity and transfer efficiency are observed. When used as a toner, the above range is preferable. At the same time, uniform surface treatment is possible, which is preferable.

  In the flow type particle image analyzer FPIP-1000, the average circularity is measured by the following method.

  First, a sample is prepared by suspending parent toner particles in water containing a trace amount of a surfactant. Next, the sample is caused to flow down into a transparent and flat cell provided in a flow type particle image analyzer FPIP-1000. A light source that emits pulsed light is provided on one side of the cell, and an imaging camera is provided on the opposite side of the cell so as to face the light source. The mother toner particles in the sample flowing down in the cell of the FPIP-1000 are captured as a still image by a camera facing the light source with the cell surrounded by the irradiation of the pulse light.

  Based on the image of the base toner particles captured in this way, the contour is extracted by the image analysis device, and the projected area and the perimeter (the perimeter of the base toner particle projected image) are calculated. Further, from the calculated projected area, the circumference of a circle having the same area as the circumference (the circumference of a circle having the same area as the base toner particle projection area) is calculated. The average circularity is obtained by dividing the circumference of a circle having the same area as the base toner particle projection area calculated in this manner by the circumference of the base toner particle projection image.

The conditions for measurement with the above device are as follows.
(1) Preparation of Suspension of Base Toner Particles To 20 g of water, 0.1 g of a surfactant (Eluclear (manufactured by Chugai Photochemical Co., Ltd.)) was added, and 0.04 g of a sample base toner was further added. Then, the base toner particles are suspended in water by an ultrasonic disperser.
(2) Measurement conditions Measurement temperature; 25 ° C
Measurement humidity: 60%
Number of measured base toner particles: 5000 ± 2000

  After coalescing the fine particles (A), the solvent is removed. The method for removing the solvent is not particularly limited, and the solvent is removed under normal pressure or reduced pressure. In order to quickly remove the solvent under low temperature conditions, it is preferable to remove the solvent under reduced pressure.

  Next, the meeting method will be described. In the association method, first, the organic solvent contained in the fine particles (A) obtained in the first step is removed. In the solvent removal step, it is not necessary to completely remove the organic solvent, and it is preferable to remove 60 to 98% of the used organic solvent. Further, it is more preferable to remove 70 to 95%, particularly preferably to remove 80 to 95%. By leaving a part of the organic solvent, the operation of the agglomeration / fusion step of the fine particles performed in the next step becomes easy, and particles having a desired particle shape can be produced. For example, it is a spherical aggregate in which fusion has progressed so as not to keep the shape of the aggregated resin particles, or an irregular aggregate in which the shape of the aggregated fine particles is hardly lost.

  Also, if the amount of the organic solvent remaining in the fine particles (A) is large, coarse particles are likely to be generated at the time of aggregation and fusion, and if the amount of the residual organic solvent is small, the fusion operation requires time or fusion. The temperature must be increased, and coarse particles are likely to be generated, which is not preferable. The remaining organic solvent is completely removed after association.

  In the association method, the dispersion of the fine particles (A) obtained in the first step is diluted with water to adjust the solid content. Thereafter, the association is advanced by dropping an aqueous solution of the electrolyte, and an aggregate having a predetermined particle size is obtained. In that case, it is preferable to add a dispersion stabilizer and perform association. The solid content before dropping the aqueous solution of the electrolyte is preferably in the range of 10 to 30% by mass. If the amount is less than 10% by mass, the amount of kettle obtained is greatly reduced, which is not preferable. On the other hand, if it is more than 30% by mass, it becomes difficult to form an aggregate having a uniform size, which is not preferable. The same electrolyte and dispersion stabilizer as those used at the time of coalescence can be used. The fusion of the aggregated particles is performed by heating the entire aqueous medium in which the aggregates are dispersed at a temperature higher than the glass transition point of the binder resin. The fusion is performed at 60 to 100 ° C, more preferably 70 to 90 ° C.

  In the third step, the united or associated body obtained in the second step is separated from the aqueous medium and dried. Separation from the aqueous medium can be performed by a known and commonly used means such as a centrifuge or a filter press or a belt filter. Then, by drying the particles, base toner particles can be obtained. It is preferable that the toner particles produced using the emulsifier and the dispersion stabilizer are more thoroughly washed.

  As the drying method, any known and commonly used method can be adopted, and examples thereof include a method of drying under normal pressure or reduced pressure at a temperature at which the base toner particles do not fuse or aggregate, a method of freeze-drying, and the like. No. In addition, a method of simultaneously separating and drying the base toner particles from the aqueous medium using a spray drier or the like is also included. In particular, a method of agitating and drying the powder under reduced pressure while heating at a temperature at which the base toner particles do not thermally fuse or agglomerate, or a flash jet drier (Seishin Co., Ltd.) in which the powder is instantaneously dried using a heated drying air flow It is efficient and preferable to use a method such as a corporation.

  Regarding the particle size distribution of the base toner, the 50% volume particle size / 50% number particle size is preferably 1.25 or less, more preferably, as measured by a Coulter Multisizer TAII type (aperture tube diameter: 100 μm). 1.20 or less. When the ratio is 1.25 or less, a good image can be easily obtained, which is preferable. GSD is preferably 1.30 or less, more preferably 1.25 or less. The GSD is a value determined by a square root of (16% volume particle size / 84% volume particle size) in a measurement with a Coulter Multisizer TAII type. The smaller the GSD value, the sharper the particle size distribution, and a better image is obtained.

  As the base toner, the volume average particle diameter is preferably in the range of 1 to 13 μm from the viewpoint of the obtained image quality and the like, and about 3 to 10 μm is easy to obtain matching with the current machine. More preferred. For a color toner, a range in which the volume average particle diameter is 3 to 8 μm is preferable. When the volume average particle diameter is small, not only the resolution and the gradation are improved, but also the effect that the thickness of the toner layer for forming a printed image is reduced and the toner consumption per page is reduced is preferable.

  When the fine particles of the charge control agent containing the inorganic fine particles are fixed to the surface of the base toner produced by the above method, various mixing and stirring devices and various surface modifying devices can be used. As the mixing and stirring device, a known and commonly used one can be used, and examples thereof include a Henschel mixer and a Q-type mixer. Examples of the surface modification device include a hybridization system (manufactured by Nara Machinery Co., Ltd.) and a mechanofusion system (manufactured by Hosokawa Micron Corporation). From the viewpoint of productivity and efficiency, a method of treating with a mixing and stirring device is preferable. If the charge control agent fine particles are not aggregated but are finely dispersed, they can be sufficiently fixed on the toner surface even by surface treatment using a mixing and stirring device.

  Further, the charge control agent fine particles containing inorganic fine particles are preferably added in the range of 0.01 to 1% by mass based on the whole toner. More preferably, it is 0.02 to 0.5% by mass, and particularly preferably 0.05 to 0.3% by mass. If the amount is less than 0.01% by mass, the effect of addition cannot be obtained, which is not preferable. If the amount is more than 1% by mass, uncharged fine particles of the charge control agent which cannot be fixed are easily generated, which is not preferable.

  If necessary, the same or different inorganic fine particles or organic fine particles may be externally added to the toner having the charge control agent fine particles containing the inorganic fine particles fixed on the surface.

  By mixing the toner particles with a carrier, an electrostatic image developer can be obtained. As the core agent (magnetic carrier) of the carrier used in the electrostatic image developer, iron powder, magnetite, ferrite, etc. used in the usual two-component developing system can be used. Among them, the true specific gravity is low, the resistance is high, and the environment is low. Ferrite or magnetite, which has excellent stability and is easy to form into a sphere and has good fluidity, are preferably used. The shape of the core agent can be used without any particular problem, such as a spherical shape and an irregular shape. The average particle size is generally 10 to 200 μm, but is preferably 30 to 110 μm for printing a high-resolution image.

  Examples of the coating resin for covering these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, and polyvinyl chloride / vinyl acetate. Copolymer, styrene / acrylic copolymer, straight silicone resin composed of organosiloxane bond or its modified product, fluororesin, (meth) acrylic resin, polyester, polyurethane, polycarbonate, phenolic resin, amino resin, melamine resin, benzoguanamine resin , Urea resin, amide resin, epoxy resin and the like can be used.

  Among these, silicone resin and (meth) acrylic resin are particularly excellent in charge stability, coating strength and the like, and can be more preferably used. In addition, the charging characteristics of the developer composed of the toner particles and the carrier can be adjusted by adjusting the coating amount of a coating agent such as silicon, adding a charge control agent, and adding a conductive material represented by carbon. That is, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier coated with at least one resin selected from silicon resin and (meth) acrylic resin using ferrite or magnetite as a core agent. It is preferable to add a charge control agent, carbon or the like during coating to adjust the charging characteristics.

  Further, the toner manufactured by the above manufacturing method may be used in a normal non-magnetic one-component developing system printing device, a two-component developing system printing device, a magnetic one-component developing system printing device, or a toner jet printer. Etc. can also be suitably used.

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, parts are parts by mass and water means deionized water unless otherwise specified.

(Fine dispersion method of charge control agent by dry method)
(Example 1)
N-01 (Nigrosine dye: Orient Chemical Industries, Ltd.) as a charge controlling agent was finely dispersed under the following conditions using a batch type high-speed planetary mill Hi-Zee (BX254E type) manufactured by Kurimoto Tekko Co., Ltd.
Into the 170 ml mill pot, 51 ml of 2 mm diameter zirconia beads were filled, and N-01 / HDK H05TA (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g) = an inorganic compound and a charge control agent in a ratio of 50/50. Was charged into a 17 ml container. After that, dispersion was performed for 3 minutes with a gravity of 150 G to perform fine dispersion.

(Fine dispersion method of charge control agent by wet method)
(Example 2)
A 5 mm diameter stainless steel bead was charged in an amount of １ ／ the volume of a ball mill, 72 parts of N-01 (Nigrosine dye: manufactured by Orient Chemical Industries), H05TA (silica manufactured by Wacker Chemicals: BET specific surface area) 8 parts of 50 m ² / g) and 320 parts of water were mixed and mixed and dispersed over 24 hours. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. The obtained dried product was stirred and mixed with a Henschel mixer to obtain fine particles comprising a mixture of an inorganic compound and a charge control agent.

(Example 3)
A 5 mm diameter stainless steel bead was charged in an amount of １ ／ the volume of a ball mill, 72 parts of N-01 (Nigrosine dye: manufactured by Orient Chemical Industries), H05TA (silica manufactured by Wacker Chemicals: BET specific surface area) 8 parts of 50 m ² / g) and 320 parts of water were mixed and mixed and dispersed over 24 hours. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. Next, 2.5 parts of H05TA was added to 20 parts of the obtained dried product of the mixture of the inorganic compound and the charge control agent, and the mixture was stirred and mixed with a Henschel mixer to form fine particles of the mixture of the inorganic compound and the charge control agent. Obtained.

(Example 4)
5 mm diameter stainless steel beads were charged in an amount of の of the ball mill volume, 72 parts of TP-415 (manufactured by Hodogaya Chemical Co., Ltd.), and H05TA (silica manufactured by Wacker Chemicals: BET specific surface area: 50 m ² / g) and 320 parts of water were mixed and mixed and dispersed over 24 hours. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. Next, 4.0 parts of H05TA was added to 20 parts of the obtained dried substance comprising the mixture of the inorganic compound and the charge controlling agent, and the mixture was stirred and mixed with a Henschel mixer to obtain fine particles comprising the mixture of the inorganic compound and the charge controlling agent. Obtained.

(Example 5)
5 mm diameter stainless steel beads were charged in an amount of な る of the ball mill volume, and 24 parts of TP-415 (manufactured by Hodogaya Chemical) and N-01 (nigrosine dye: manufactured by Orient Chemical Industries) were used. Forty-eight parts, 8 parts of H05TA (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g) and 320 parts of water were charged and mixed and dispersed over 24 hours. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. Next, 2.5 parts of H05TA was added to 20 parts of the obtained dried product of the mixture of the inorganic compound and the charge control agent, and the mixture was stirred and mixed with a Henschel mixer to form fine particles of the mixture of the inorganic compound and the charge control agent. Obtained.

(Example 6)
72 parts of E-84 (manufactured by Orient Chemical Industries), 8 parts of H05TD (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g), and 320 parts of a solvent having a water / acetone ratio of 80/20 were charged. After the dispersion, the dispersion was carried out using an Eiger motor mill (M-250, manufactured by Eiger, USA) filled with zirconia beads having a diameter of 1.5 mm. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. Next, 2.5 parts of H05TD was added to 20 parts of the obtained dried product of the mixture of the inorganic compound and the charge control agent, and the mixture was stirred and mixed with a Henschel mixer to obtain fine particles of the mixture of the inorganic compound and the charge control agent. Obtained.

(Comparative Example 1)
5 mm diameter stainless steel beads were charged in an amount of と the volume of the ball mill, 80 parts of N-01 (Nigrosine dye: manufactured by Orient Chemical Industries) and 320 parts of water were charged and mixed for 24 hours. Dispersion was performed. The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. The obtained dried product was stirred and mixed by a Henschel mixer to obtain fine particles consisting only of a charge controlling agent.

(Comparative Example 2)
80 parts of E-84 (manufactured by Orient Chemical Co., Ltd.) and 320 parts of a solvent having a water / acetone ratio of 80/20 were charged and shake-dispersed, and then filled with zirconia beads having a diameter of 1.5 mm. (M-250). The obtained dispersion solution was subjected to solid-liquid separation by a centrifugal separator, and the supernatant was separated by decantation, and the wet cake was dried by a freeze dryer for 24 hours. Next, the obtained dried product was stirred and mixed with a Henschel mixer to obtain fine particles of a charge controlling agent.

  Examples 7 to 11 and Comparative Examples 3 to 6 were produced in the same manner as in Example 3, except that only the charge control agent and the inorganic fine particles shown in Table 1 were changed. Table 1 shows the composition of each Example and Comparative Example.

H-05TA ワッカーケミカルズ社製 シリカ
H-13TA ワッカーケミカルズ社製 シリカ
H-05TD ワッカーケミカルズ社製 シリカ
H-13TD ワッカーケミカルズ社製 シリカ
EC-300 チタン工業（株）社製 導電性チタン
EC-210 チタン工業（株）社製 導電性チタン
SW-360 チタン工業（株）社製 チタン酸ストロンチウム
SW-320 チタン工業（株）社製 チタン酸ストロンチウム

H-05TA Silica made by Wacker Chemicals
H-13TA Silica manufactured by Wacker Chemicals
H-05TD Silica made by Wacker Chemicals
H-13TD Silica manufactured by Wacker Chemicals
EC-300 Conductive titanium made by Titanium Industry Co., Ltd.
EC-210 Conductive titanium made by Titanium Industry Co., Ltd.
SW-360 Strontium titanate manufactured by Titanium Industry Co., Ltd.
SW-320 Strontium titanate manufactured by Titanium Industry Co., Ltd.

  Table 2 shows the evaluation results of the fine particles obtained in Examples and Comparative Examples.

  The peak volume particle size was measured using LS-910 manufactured by Horiba Ltd., and the particle size with the highest volume frequency of the measured values was taken as the measured value. For the volume% of 10 μm or more, a value obtained by measurement with a Coulter Multisizer TAII type (aperture tube diameter: 100 μm) was used as a measured value. The measurement sample was performed after each of the obtained fine particles was added to water to which an emulsifier was added, and dispersed by ultrasonic waves for 1 to 30 minutes. The BET specific surface area was measured using a fluid type specific surface area measuring device (Shimadzu FLOW SORB-II 2300) manufactured by Shimadzu Corporation. The aggregation state is determined by adding the obtained fine particles to water to which an emulsifier has been added or to a mixed solution of water / organic solvent, performing dispersion by ultrasonic waves for 1 to 30 minutes, and then using a 200 × optical microscope. Observation was conducted by, も の: almost no aggregates were observed, を: slightly 5 μm or less aggregates were observed, ○: 5 to 10 μm aggregates were slightly observed, Δ: 20 μm or more aggregates were observed. Is given as x.

(Example of production of base toner)
(Example of polyester resin synthesis)
Trimellitic anhydride (TMA) as a polycarboxylic acid, terephthalic acid (TPA), isophthalic acid (IPA) as a divalent carboxylic acid, and polyoxypropylene (2.4) -2,2-bis (4) as an aromatic diol -Hydroxyphenyl) propane (BPA-PO), polyoxyethylene (2.4) -2,2-bis (4-hydroxyphenyl) propane (BPA-EO), and ethylene glycol (EG) as an aliphatic diol. Using tetramol titanate as a polymerization catalyst in a separable fresco at 0.3% by mass based on the total amount of monomers, a thermometer, a stirring rod, a condenser, and a nitrogen inlet tube were provided above the flask. The reaction was carried out at 220 ° C. for 15 hours under a normal nitrogen flow in an attached electric heating mantle heater. The reaction was continued at mHg. The reaction was followed by a softening point according to ASTM E28-517, and when the softening point reached a predetermined temperature, the vacuum was stopped to terminate the reaction. Table 3 shows the composition and physical property values (characteristic values) of the synthesized resin.

＞６０万；分子量６０万以上の成分の面積比率
＜１万 ；分子量１万以下の成分の面積比率
ＴＭＡ；無水トリメリット酸
ＴＰＡ；テレフタル酸
ＩＰＡ；イソフタル酸
ＢＰＡ−ＰＯ；ポリオキシプロピレン（２．４）−２，２−ビス（４−ヒドロキシフェニル）プロパン
ＢＰＡ−ＥＯ；ポリオキシエチレン（２．４）−２，２−ビス（４−ヒドロキシフェニル）プロパン
ＥＧ；エチレングリコール
ＦＴ値；フローテスター値

>600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less TMA; trimellitic anhydride TPA; terephthalic acid IPA; isophthalic acid BPA-PO; polyoxypropylene (2. 4) -2,2-bis (4-hydroxyphenyl) propane BPA-EO; polyoxyethylene (2.4) -2,2-bis (4-hydroxyphenyl) propane EG; ethylene glycol FT value; flow tester value

As described above, the softening point of the resin in the present invention is defined by the T1 / 2 temperature measured using a flow tester CFT-500 manufactured by Shimadzu Corporation which is a constant load extrusion type capillary rheometer. The measurement conditions of the flow tester were as follows: piston cross-sectional area 1 cm ² , cylinder pressure 0.98 MPa, die length 1 mm, die hole diameter 1 mm, measurement start temperature 50 ° C, heating rate 6 ° C / min, sample mass 1. This was performed under the condition of 5 g. The glass transition temperature “Tg” (° C.) is an on-set value measured by a second run method at a rate of 10 ° C./minute using a differential scanning calorimeter (DSC-50) manufactured by Shimadzu Corporation. .

(Preparation example of release agent dispersion)
After kneading 30 parts of carnauba wax “Carnauba wax No. 1” (imported by Yoko Kato) and 50 parts of a polyester resin (R1 in Table 3) with a pressure kneader, the kneaded product and 185 parts of methyl ethyl ketone were charged into a ball mill. After stirring for an hour, the mixture was taken out, the solid content was adjusted to 35% by mass, and a fine dispersion of a release agent was obtained.

(Preparation example of colorant master chip)
The coloring pigment and the resin R1 were kneaded at a mass ratio of 40/60 according to the composition shown in Table 4 to prepare a coloring agent master chip P1. The color pigment and the resin were kneaded using a pressure kneader.

表４に示した着色剤は以下の通りである。
黒色顔料：チタン工業社製黒色顔料「ETB-100」

The coloring agents shown in Table 4 are as follows.
Black pigment: Black pigment "ETB-100" manufactured by Titanium Industry Co., Ltd.

  After the color pigment and the resin (R1 in Table 3) were melt-kneaded with a heated two-roll in the composition of Table 5, methyl ethyl ketone was added to the obtained kneaded material so that the solid content was 30 to 35% by mass. In addition, a colorant master solution was prepared by wet dispersion with an Eiger motor mill (M-1000, manufactured by Eiger Corporation, USA). The solid content was adjusted to 30% by mass with methyl ethyl ketone.

（帯電制御剤分散液の調製例）
表６の組成にて帯電制御剤とメチルエチルケトンを３０／７０の質量比率で配合し、モーターミル（米国アイガー社製）で分散を行い、固形分含有量を３０質量％に調整し、帯電制御剤分散液を得た。

(Example of preparation of charge control agent dispersion)
The charge controlling agent and methyl ethyl ketone were mixed at a mass ratio of 30/70 in the composition shown in Table 6, dispersed by a motor mill (manufactured by Eiger Corporation, USA), and the solid content was adjusted to 30% by mass. A dispersion was obtained.

・Ｎ−０４；ボントロンＮ−０４（オリエント化学工業社製、ニグロシン染料）

N-04; Bontron N-04 (Nigrosine dye, manufactured by Orient Chemical Co., Ltd.)

(Preparation Example of Mill Base MB1)
47.6 parts of the release agent dispersion (R1 content: 11.7 parts), 24 parts of the colorant master chip P1 (R1 content: 12 parts), diluent resin (additional resin), methyl ethyl ketone The mixture was added and mixed for 3 hours by a disper at a temperature condition of 30 to 40 ° C. to dissolve and disperse. The resulting mixture was mill-based with the solids content adjusted to 60%. At this time, the mass ratio of each raw material was R1 / R2 / colorant / wax = 49.8 / 33.2 / 12/5.

(Preparation Example of Mill Base MB2)
47.6 parts of the release agent dispersion (R2 content: 11.7 parts), 20 parts of the colorant master chip P2 (R2 content: 3 parts), diluent resin (additional resin), and methyl ethyl ketone The mixture was added and mixed for 3 hours by a disper at a temperature condition of 30 to 40 ° C. to dissolve and disperse. The resulting mixture was mill-based with the solids content adjusted to 60%. At this time, the mass ratio of each raw material was R1 / R2 / colorant / wax = 55.2 / 36.8 / 3/5.

  Table 7 shows the properties of the blend resins used in the production of the mill base. The resin blend was prepared by blending resin particles having passed through a 200 mesh at the above-mentioned mass ratio and measuring respective physical property values.

＞６０万；分子量６０万以上の成分の面積比率
＜１万 ；分子量１万以下の成分の面積比率

>600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less

In addition, the resin obtained in each synthesis example was placed in tetrahydrofuran (THF), and the solution was allowed to stand for 12 hours. The solution was filtered, and the molecular weight of the THF-soluble component obtained was measured. For the analysis, the molecular weight was calculated from a calibration curve prepared with standard polystyrene using a gel permeation chromatography (GPC) method.
GPC equipment: HLC-8120GPC manufactured by Tosoh Corporation
Column: Tosoh Corporation TSK Guardcolumn SuperH-H TSK-GEL SuperHM-M 3 concatenation
Concentration: 0.5% by mass
Flow rate: 1.0 ml / min

The tetrahydrofuran-insoluble content of the binder resin was determined by the following method.
A value obtained by precisely weighing 1 g of the resin is defined as (X). This resin is dissolved in 40 ml of tetrahydrofuran, and then filtered using a funnel (diameter 40 mm) in which 2 g of radiolite (# 700 manufactured by Showa Chemical Co., Ltd.) is uniformly filled on Kiriyama filter paper (No. 3). The filtrate is placed on an aluminum Petri dish, dried at 140 ° C. for 1 hour, and the mass (Y) of the resin contained in the filtrate is measured. The tetrahydrofuran insoluble content is calculated by the following equation.
Tetrahydrofuran insoluble matter (%) = {1- (Y) / (X)} × 100

  The acid value was measured according to JIS K6901, and the Tg was measured according to JIS K7121.

(Preparation Example 1 of Base Toner)
A cylindrical 2 L separable flask having a Max blend blade as a stirring blade was charged with 480 parts of millbase MB1, 40 parts of nigrosine dispersion E1, and 25.5 parts of methyl ethyl ketone, and the solid content was adjusted to 55%. Next, 38.4 parts of 1N ammonia water (the equivalent ratio to the total amount of carboxyl groups of the resins R1 and R2 is 1.2) was added, and the mixture was sufficiently stirred at 210 rpm by a three-one motor. In addition, stirring was further performed to adjust the temperature to 23 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to produce a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time was 0.71 m / s. Next, 259 parts of deionized water was added (the amount of deionized water so that the total amount of 1N ammonia water and water was 563 parts) to adjust the amount of solvent.

The equivalent ratio of the basic compound (aqueous ammonia) to the total amount of the carboxyl groups of the resins R1 and R2 in Preparation Example 1 of the parent toner was determined by the following calculation.
(1) Total amount of carboxyl groups of resins R1 and R2 (A)
7.7 (resin acid value) × 288 (mill base solid content) × 0.89 (resin ratio in solid content) /56100=0.0320 mol
(2) Amount of hydroxyl group in 38.4 parts of 1N ammonia water (B)
1 × 38.4 / 1000 = 0.0384 mol
(3) Basic compound (aqueous ammonia) equivalent (B) / (A)
0.0474 / 0.0352 = 1.2

  (Coalescence operation) Then, 2.8 parts of Emal 0 (manufactured by Kao Corporation), which is an anionic emulsifier, was diluted with 30 parts of water and added. Thereafter, the temperature was adjusted to 25 ° C., the number of revolutions was adjusted to 158 rpm, and an aqueous solution of 5.2% ammonium sulfate was dropped until the particle size grew to 5.5 μm, and then the particle size was reduced to 7 μm under the same conditions. Stirring was continued until the growth, and the coalescing operation was completed. Thereafter, solid-liquid separation was performed using a centrifugal separator, and the additive was washed by performing rinsing three times, and then dried using a mixed vacuum dryer to obtain a base toner. The volume average particle size of Dv50 was 7.2 μm, the Dv / Dn was 1.10, and the number% of 5 μm or less was 11.0%. Further, the average circularity was 0.981, and the toner was a spherical base toner whose surface was covered with a curved surface. After the obtained mother toner was embedded in a resin, it was cut with a microtome and observed with a TEM. As a result, it was confirmed that the nigrosine particles were dispersed to 0.5 μm or less.

(Preparation Example 2 of Base Toner)
500 parts of Millbase MB1 and 45.5 parts of methyl ethyl ketone were charged into a cylindrical 2 L separable flask having a Max blend blade as a stirring blade, and the solid content was adjusted to 55%. Next, 49.4 parts of 1N ammonia water (the equivalent ratio to the total amount of carboxyl groups of the resins R1 and R2 is 1.2) was added, and the mixture was sufficiently stirred at 210 rpm by a three-one motor, and 133 parts of deionized water was added. In addition, stirring was further performed to adjust the temperature to 23 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to produce a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time was 0.71 m / s. Next, 248 parts of deionized water was added (the amount of deionized water so that the total amount of 1N ammonia water and water was 563 parts) to adjust the amount of solvent.

  Next, a coalescing operation was performed in the same manner as in Preparation Example 1 of the base toner to obtain a base toner. The volume average particle diameter of Dv50 was 7.3 μm, the Dv / Dn was 1.10, and the number% of 5 μm or less was 10.8%. Further, the average circularity was 0.983, and the toner was a spherical base toner whose surface was covered with a curved surface.

(Preparation Example 3 of parent toner)
500 parts of Millbase MB2 and 45.5 parts of methyl ethyl ketone were charged into a cylindrical 2 L separable flask having a Max blend blade as a stirring blade, and the solid content was adjusted to 55%. Next, 41.7 parts of 1N ammonia water (the equivalent ratio to the total amount of carboxyl groups of the resins R1 and R2 is 1.1) was added, and the mixture was sufficiently stirred at 210 rpm by a three-one motor, and 133 parts of deionized water was added. In addition, stirring was further performed to adjust the temperature to 25 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to produce a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time was 0.71 m / s. Next, 285 parts of deionized water was added (the amount of deionized water so that the total amount of 1N ammonia water and water was 593 parts) to adjust the amount of solvent.

  Next, a coalescing operation was performed in the same manner as in Preparation Example 1 of the base toner to obtain a base toner. The peripheral speed of the stirring blade at this time was 0.54 m / s. The volume average particle diameter of Dv50 was 7.3 μm, Dv / Dn was 1.09, and the number% of 5 μm or less was 9.70%. Further, the average circularity was 0.985, and the toner was a spherical base toner whose surface was covered with a curved surface.

(Application Example 1)
To 100 parts of the base toner obtained in the preparation example of the base toner, 0.075 parts of the fine particles composed of the inorganic compound and the charge control agent obtained in Example 1 were added, and the peripheral speed was 40 m / h using a Henschel mixer. The surface was fixed under the conditions of s and a stirring time of 10 min. In the same manner, toners of Application Examples 2 to 7 were produced. Table 7 shows formulation examples.

  In the same manner as in Application Example 1, the toners of Application Examples 2 to 12 were produced. Table 8 shows formulation examples.

(Reference Example 1)
0.15 parts of the charge control agent fine particles obtained in Comparative Example 2 was added to 100 parts of the base toner obtained in Preparation Example 2 of the base toner, and H05TD (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g). Was added and the surface was fixed with a Henschel mixer at a peripheral speed of 40 m / s and a stirring time of 10 min.

(Reference Example 2)
0.15 parts of the charge control agent fine particles obtained in Comparative Example 2 was added to 100 parts of the base toner obtained in Preparation Example 2 of the base toner, and H05TD (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g). Was added and the surface was fixed with a hybridization system (Nara Machinery Co., Ltd.) under the conditions of a peripheral speed of 60 m / s and a stirring time of 2 min.

(Reference Example 3)
0.10 part of the fine particles of the charge control agent obtained in Comparative Example 1 was added to 100 parts of the base toner obtained in Preparation Example 2 of the base toner, and H05TA (silica manufactured by Wacker Chemicals: BET specific surface area 50 m ² / g). Was added and the surface was fixed with a Henschel mixer at a peripheral speed of 40 m / s and a stirring time of 10 min.

  The toners of Reference Examples 4 to 7 were produced in the same manner as in Reference Example 1. Table 9 shows formulation examples.

（評価方法）
１）ＳＥＭによる固着状態の観察：
応用例、参考例で得られたトナー粒子をＳＥＭで観察してトナー表面への固着状態、及び遊離した帯電制御剤微粒子の有無を目視で評価した。粒子表面へ均一に帯電制御剤微粒子が固着し、遊離した粒子が見られないものを○、１〜２μｍの業種した帯電制御剤粒子が表面に固着しており、均一性がやや劣るが、遊離した帯電制御剤粒子が見られないものを△、遊離した帯電制御剤粒子が確認されるものを×とした。
２）帯電安定性：
シリコンコートフェライトキャリア（パウダーテック社製）と応用例、参考例で得られたトナーの比率を９７／３とした現像剤を調製し、該現像剤を６０min及び180min間攪拌した後の帯電量、及び１８０min後の帯電量の標準偏差をE-SPARTアナライザーの測定により求めた。
評価結果を表１０に示した。

(Evaluation method)
1) Observation of fixation state by SEM:
The toner particles obtained in the application examples and the reference examples were observed with a SEM, and the state of fixation to the toner surface and the presence or absence of the released charge control agent fine particles were visually evaluated. The charge control agent fine particles uniformly adhered to the surface of the particles, and those in which no released particles were observed were evaluated as ○, and the charge control agent particles of 1 to 2 μm in the industry were fixed on the surface, and the uniformity was slightly inferior. A sample in which no charge control agent particles were observed was evaluated as Δ, and a sample in which free charge control agent particles were observed was evaluated as ×.
2) Charging stability:
A silicone-coated ferrite carrier (manufactured by Powdertech) and a developer were prepared in which the ratio of the toner obtained in the application example and the reference example was 97/3, and the developer was stirred for 60 minutes and 180 minutes, And the standard deviation of the charge amount after 180 minutes was determined by measurement with an E-SPART analyzer.
Table 10 shows the evaluation results.

In the application examples 3 to 12, the charge control agent fine particles are uniformly fixed on the particle surface, the charge amount is stable even after stirring with the carrier for a long time, and the number% of different charges is small. On the other hand, in the application examples 1 and 2 in which the fixation state is slightly non-uniform, the charge amount changes with time and the standard deviation of the charge amount tends to increase. Further, in Reference Examples 1 to 7 which include free charge control agent fine particles having a non-uniform surface fixation state, the charge amount changes greatly with time, and the standard deviation of the charge amount also increases. This tendency is correlated with the state of fixation of the charge control agent on the surface of the particles, and the state of fixation is correlated with the state of aggregation of the charge control agent. It turns out that it is important to control the state so that there is no aggregate.

Claims (5)

A method for finely pulverizing a charge control agent for a toner, wherein the method is a method for finely pulverizing the charge control agent with a mechanical pulverizer in the presence of inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g. A method for finely pulverizing a charge control agent for toner. A first pulverizing step of finely pulverizing a toner charge control agent with a mechanical pulverizer in the presence of inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g and water or an organic solvent, and removing the water or organic solvent; Separating a mixture of the inorganic fine particles and the fine particles of the charge control agent, drying the mixture, and adding the inorganic fine particles having a BET specific surface area of 20 to ²⁰⁰ m ² / g to the dried mixture. A method for finely pulverizing a charge control agent for toner, comprising sequentially performing a second pulverization step of finely pulverizing with a stirring mixer. The pulverization method according to claim 1, wherein a total use ratio (mass ratio) of the inorganic fine particles to the charge control agent is 90/10 to 20/80. The color dispersion obtained by dissolving or dispersing a colorant and a binder resin containing a carboxyl group in an organic solvent is emulsified in an aqueous medium in the presence of a basic compound, whereby fine particles (A) of the color dispersion are dispersed. An emulsification step of forming, an evaporation step of forming colored resin fine particles (B) by evaporating and removing an organic solvent in the fine particles (A), and a separation of separating the colored resin fine particles (B) from an aqueous medium and drying. A drying step, and a surface treatment step of fixing fine particles of the charge control agent containing the inorganic fine particles obtained by the method according to any one of claims 1, 2 and 3 on the surface of the colored resin fine particles (B). Are carried out sequentially. After the emulsification step, a coalescence step of coalescing the fine particles (B) of the colored dispersion by adding an electrolyte in the presence of a dispersion stabilizer to form coalesced particles of 3 to 10 μm is performed. 5. The method for producing an electrostatic image developing toner according to item 4.