JP2011013523A - Method for manufacturing toner particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing toner particles by which a toner showing excellent developability is obtained by irradiating the toner particles with ultrasonic waves during a polymerization reaction, and which is adaptable to a mass production scale, with respect to a method for manufacturing toner particles manufactured by a wet process.SOLUTION: In a step where a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is dispersed in an aqueous dispersion medium and the polymerizable monomer in the resulting dispersion is polymerized, an ultrasonic treatment is carried out by vibrating a vibrator 2 of an ultrasonic generator 1 in the dispersion. The vibrator 2 for emitting ultrasonic waves has protrusions in the circumferential direction of a cylinder, wherein the protrusions form coaxial circles relative to the cylinder.

Description

  The present invention relates to a method for producing toner particles contained in a toner for developing an electrostatic latent image in an image forming method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, or a toner jet method.

  Conventionally, in electrophotography, an electric latent image is formed on a photoreceptor by various means, and then the latent image is developed with toner, and the toner image is transferred to a transfer material such as paper as necessary. Thereafter, the toner image is fixed by heating, pressure, heating pressure or solvent vapor.

  In recent years, toners are roughly classified into pulverized toners and wet granulated toners. In the pulverized toner, a colorant is melt-mixed in a thermoplastic resin and uniformly dispersed, and then the melt-kneaded product is cooled and solidified. The kneaded product is pulverized by a pulverizer, and the pulverized product is classified by a classifier. It is manufactured by obtaining toner particles having a desired particle size.

  On the other hand, wet granulated toner is attracting attention because it can reduce the particle size and sharpen the particle size distribution and is advantageous for introducing a large amount of a release agent. This is because electrophotography demands high-definition and high-quality images from many users, and reducing the particle size of toner and sharpening the particle size distribution can be effective means.

  As specific toner production methods for wet granulation, various polymerization method production methods such as suspension polymerization method, emulsion polymerization method, dissolution suspension method using separately polycondensed polyester, etc. have been proposed. ing.

  For example, in the suspension polymerization method, a polymerizable monomer and a colorant (and a release agent, a polymerization initiator, a crosslinking agent, a charge control agent and other additives as necessary) are dispersed and / or dissolved to be polymerizable. A monomer composition is prepared. This polymerizable monomer composition is granulated and polymerized with toner particles having a desired particle size in a liquid dispersion medium using various granulating apparatuses to obtain a toner particle dispersion. Thereafter, the toner particles are obtained through filtration, washing and drying, and classification as necessary. A toner is manufactured by adding a predetermined additive to the obtained toner particles (see Patent Document 1).

  The dispersion state of the colorant or the like in the toner particles described above greatly affects the developability such as the coloring power of the obtained toner. Therefore, in order to improve the dispersibility of the colorant and the compatibility with other components, the configuration of the disperser and the method of adding the coupling agent are disclosed (see Patent Documents 2 and 3). These techniques yield toners that exhibit the effect of improving the dispersibility of colorants and the like and improving the compatibility and exhibiting excellent developability. However, the dispersibility of the colorant is lost in the course of the granulation / polymerization process following the dispersion / dissolution process of these raw materials, and the re-aggregation of the colorant and segregation of the dissolved components occur, resulting in loss of uniformity in the system. . For this reason, it does not fully satisfy the needs for high definition and high image quality of images that have recently been demanded, and further improvements are required.

  From the viewpoint of controlling the particle size and particle size distribution of the toner particles, a method of irradiating ultrasonic waves during the polymerization reaction in the presence of a surfactant, or superposition during the polymerization reaction to prevent the droplets from being coalesced during polymerization. There is a method of irradiating a sound wave (see Patent Documents 4 and 5). In addition, a method for deoxygenating the system by irradiating ultrasonic waves at the initial stage of polymerization for the purpose of controlling the oxygen concentration at the initial stage of polymerization is also disclosed (see Patent Document 6). These are effective means for sharpening the particle size distribution of the obtained toner particles, but have not been verified at all in terms of dispersion of colorants, etc., and have high image definition and high image quality. There is a need for further technology exploration.

  On the other hand, the toner manufacturing method is required to improve mass productivity in order to cope with further cost reduction. When an ultrasonic generator is used in an actual plant for the purpose of mass production, a large ultrasonic generator is required. When the equipment becomes large, the ultrasonic generator has very poor conversion efficiency from driving means such as electric power to ultrasonic waves due to its device characteristics. For this reason, until now, scale-up of ultrasonic generators has been limited to a limited size in an actual plant aimed at mass production. And to scale up beyond that size, a technique called numbering up corresponding to mass production by arranging several devices was taken. However, this numbering UP method cannot be expected to reduce the cost by increasing the size of the system. That is, the equipment cost for initial investment is high, and it is difficult to cope with the cost reduction of the toner manufacturing method. In addition, the toner manufacturing methods described in Patent Documents 4, 5, and 6 do not describe means for solving these problems in mass production, and further technical deepening has been demanded.

Japanese Patent Laid-Open No. 51-14895 JP 2005-292422 A JP 2006-201543 A Japanese Patent Laid-Open No. 01-099062 JP 2000-162813 A JP-A 63-046474

  An object of the present invention is to provide a method for producing toner particles that solves the above-described problems.

  That is, the present invention provides a method for producing toner particles that can be applied to a mass production scale, in a method for producing toner particles produced by a wet method, to obtain a toner exhibiting excellent developability by irradiating ultrasonic waves during a polymerization reaction. The purpose is to do.

  As a result of intensive studies, the present inventors have found a technique for obtaining toner particles exhibiting excellent developability when irradiated with ultrasonic waves by a special ultrasonic generator during the polymerization reaction of the toner particles, and completed the present invention. It was. That is, when an ultrasonic generator having a special structure of the vibrator is used, the present invention has found that the conversion efficiency does not decrease when driving means such as electricity is converted to ultrasonic even in a large-scale machine of mass production scale. Was completed.

  That is, the present invention includes at least a polymerization step of polymerizing a polymerizable monomer in a dispersion obtained by dispersing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium. In the polymerization step, the method includes a vibrator for irradiating ultrasonic waves having convex portions in the circumferential direction of the cylinder, and the convex portions are concentric with the cylinder. A method for producing toner particles, wherein ultrasonic treatment is performed to vibrate the vibrator of an ultrasonic generator, which is a convex portion forming the surface, in a dispersion.

  According to the present invention, in a method for producing toner particles produced in a wet process, the production of toner particles that can be applied to a mass production scale when ultrasonic particles are irradiated during the polymerization reaction to obtain toner particles exhibiting excellent developability. A method can be provided.

It is the schematic of the ultrasonic generator concerning this invention. It is an example of the circulating polymerization system incorporating the ultrasonic generator according to the present invention. It is another example of the superposition | polymerization system incorporating the ultrasonic generator concerning this invention. It is the schematic of the conventional ultrasonic generator. It is an example of the circulation polymerization system incorporating the conventional ultrasonic generator. It is an example of the superposition | polymerization system incorporating the conventional ultrasonic generator. It is an example of the superposition | polymerization system which has arrange | positioned several conventional ultrasonic generators in series.

  FIG. 1 is a schematic view of an ultrasonic generator used in the present invention. 2 and 3 are preferable examples of a granulation system using the ultrasonic generator. However, the present invention is not limited to these. Hereinafter, the present invention will be described in detail.

  In the polymerization system shown in FIGS. 2 and 3, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant prepared in advance is dispersed in an aqueous dispersion medium in the described granulation step to be polymerizable. A dispersion of the monomer composition is obtained. This dispersion is transferred to the polymerization tank 9 through the pipe 18 and stirred by the stirring blade 7. A polymerization process for polymerizing the polymerizable monomer in the polymerizable monomer composition dispersion in the polymerization tank 9 is advanced. Ultrasonic waves are irradiated by the ultrasonic generator 1 during the polymerization process. As a result, the colorant in the dispersed droplets of the polymerizable monomer composition is redispersed.

  An ultrasonic generator 1 suitably used in the present invention shown in FIG. 1 has an ultrasonic transducer 2 for irradiating an ultrasonic wave having a convex portion in the circumferential direction of a cylinder, and the convex portion is It is a convex part which forms a concentric circle with respect to a cylinder, and the upper surface and the bottom face of the convex part are an apparatus called an ultrasonic irradiation unit 3. Moreover, the convex part of the ultrasonic transducer | vibrator 2 has a special structure provided with two or more in the height direction of this cylinder. Conventionally, as shown in FIG. 4, the ultrasonic generator 13 has a structure having an ultrasonic irradiation unit 17 at the bottom of the cylinder of the vibrator 14 and locally generates ultrasonic waves. When a large ultrasonic wave is to be output from the ultrasonic generator having such a structure, an output loss occurs because the ultrasonic output per unit area is large and it is necessary to locally generate the ultrasonic wave. This large output loss makes it difficult to manufacture a large machine, and even if a large machine is manufactured, the efficiency of converting ultrasonic driving force (for example, electricity) into ultrasonic waves is deteriorated. That is, since the ultrasonic generator 1 according to the present invention includes the special ultrasonic irradiation unit 3, it can perform ultrasonic irradiation from a wide range. As a result, the efficiency of converting the ultrasonic driving force (for example, electricity) into ultrasonic waves is improved, and it is possible to manufacture a large machine capable of responding to mass production. As described above, the dispersed droplets of the polymerizable monomer composition irradiated with ultrasonic waves by the large ultrasonic generator equipped with the special ultrasonic irradiation unit 3 shown in FIG. Toner particles exhibiting developability can be obtained.

  In this polymerization system, the frequency, amplitude, driving power, and stirring rotation speed of the ultrasonic generator can be changed, and preferable conditions are appropriately determined from the viscosity of the polymerizable monomer composition, the performance of the desired toner particles, and the like. Can be set. Furthermore, the ultrasonic irradiation method can be arbitrarily set according to the viscosity and polymerization rate of the polymerizable monomer composition, and may be irradiated continuously for a certain period of time, irradiation or non-irradiation. You may repeat at arbitrary intervals. Further, in this polymerization system, in order to perform polymerization at a certain constant temperature, the polymerization tank has a jacket structure (not shown), and warm water or steam, cold water or the like is allowed to flow through the jacket, It is preferable to perform temperature control. In the present invention, heat may be generated when the ultrasonic generator is driven. However, the heat may be effectively used for the temperature control. The particles that have undergone the polymerization are sent to a subsequent process, and become toner particles through filtration, washing, and classification as required.

  FIG. 2 shows an example in which the ultrasonic generator 1 according to the present invention shown in FIG. 1 is incorporated in a circulation polymerization system. In FIG. 2, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant prepared in advance is dispersed in an aqueous dispersion medium by the described granulation step. A dispersion is obtained. The dispersion is transferred to the polymerization tank 9 via the pipe 18 and the polymerization process is advanced while stirring with the stirring blade 7. During polymerization of the polymerizable monomer, a part of the dispersion in the polymerization tank 9 is driven by the pump 10 to drive the pressure gauge 5b, the thermometer 4b, the ultrasonic processing chamber 19, the thermometer 4a, the pressure gauge 5a, and the back pressure valve 20. Then, the ultrasonic generator 1 is started by circulating through the circulation line 12 in the order of the circulation outlet 6.

  As described above, the ultrasonic generator 1 provided outside the polymerization tank that contains the dispersion has the special ultrasonic irradiation unit 3. On the other hand, FIG. 7 shows an example in which the conventional ultrasonic generator 13 is incorporated into a circulation polymerization system for mass production. Conventionally, for the reason that it is difficult to manufacture a large-sized ultrasonic generator, a plurality of ultrasonic generators are connected in series as shown in FIG. With this method, it is necessary to install a large number of ultrasonic generators 13, which not only increases initial investment, but also requires careful attention to each of the plurality of units in maintenance, which requires much labor.

  On the other hand, since the ultrasonic generator 1 according to the present invention includes the special ultrasonic irradiation unit 3, it is possible to manufacture a large machine capable of being mass-produced. In other words, as shown in FIG. 2, when incorporating into a mass production-use circulation polymerization system, the system can be assembled with a minimum number of ultrasonic generators (one example in FIG. 2).

  As described above, the dispersed droplets of the polymerizable monomer composition irradiated with ultrasonic waves by the system shown in FIG. 2 are toner particles exhibiting excellent developability due to progress of redispersion of the colorant during polymerization of the monomer. Can be obtained. In this circulation polymerization system, the frequency of the ultrasonic generator, the driving power, the stirring rotation speed, the pump discharge amount, and the circulation pressure can be changed, and the viscosity of the colorant-containing polymerizable monomer composition and finally desired The preferable conditions can be appropriately used depending on the particle diameter and the like.

  Further, in this circulation polymerization system, in order to carry out polymerization at a certain constant temperature, the polymerization tank 9 and the ultrasonic treatment chamber have a jacket structure (not shown), and hot water or steam is contained in the jacket, as necessary. It is preferable to flow cold water or the like to control the temperature in the container. Further, the temperature control may be performed by covering the circulation pipe with a heat insulating material or by forming a jacket structure (both not shown). Furthermore, the heat generated by the ultrasonic generator described above may be used for the temperature control. Thereafter, the polymerization-completed particles are sent to a post-process and become toner particles through filtration, washing, and classification as required.

  Further, when this circulation polymerization system is assembled, it is preferable that the circulation outlet 6 is in the dispersion of the polymerizable monomer composition in the polymerization tank 9. If the circulation outlet is arranged outside the dispersion, the gas in the polymerization tank 9 is entrained in the dispersion when the dispersion passing through the circulation line 12 is discharged from the circulation outlet. This gas is not preferable because it deteriorates the efficiency of ultrasonic irradiation to the dispersion.

Further, when the output per ultrasonic generator is A (W) and the ultrasonic irradiation area per ultrasonic generator is B (cm ² ), A ≧ 2000 and A / B is 25. ≦ A / B ≦ 70 is preferable. A <2000 results in a small machine as described above, and many ultrasonic generators are required for mass production, which is not preferable. Further, when A / B <25, the desired dispersion ability cannot be obtained, and the dispersion of the pigment in the obtained toner particles becomes insufficient, and the pigment is unevenly distributed. Further, when A / B> 70, the ultrasonic output is locally performed as described above, the efficiency of ultrasonic generation from the (for example, electric) driving means is deteriorated, and a large-sized apparatus that can cope with mass production. Is not preferred.

  In the polymerization step, when the total amount V (l) of the dispersion of the polymerizable monomer composition, the circulation flow rate C (l / min) of the dispersion, and the ultrasonic treatment time T (min), C · It is preferable that T / V ≧ 2. In the case of C · T / V <2, a considerable amount of the untreated polymerizable monomer composition dispersion remains without being sent to the ultrasonic irradiation chamber. The toner particles produced from this untreated dispersion have a low coloring power because the pigment is not dispersed. As a result, toner particles having low coloring power are included in the entire toner particles obtained, which leads to a decrease in toner performance, which is not preferable.

  Further, at least the conversion rate of the polymerizable monomer in the dispersion is sonicated within the range of 15% or more and 80% or less, and the sonication time t (min) within the conversion rate range is 30. It is preferable to be within the range of ≦ t. When the conversion rate is less than 15% and irradiation with ultrasonic waves is performed, the polymerizable monomer droplets are unstable, so that a part of the dispersed droplets of the polymerizable monomer composition is overdispersed and the desired particle size is reduced. Predetermined outer particles smaller than the diameter are generated and the particle size distribution becomes broad. These non-predetermined particles deteriorate the developability. Further, although the developability is somewhat improved by removing predetermined non-specific particles by classification in a subsequent step, it is not preferable because a decrease in yield is unavoidable as compared with normal classification. When the conversion rate exceeds 80%, polymerization of the polymerizable monomer is progressing, so the polymer in the dispersed droplets of the polymerizable monomer composition inhibits the dispersion of the colorant. The colorant redispersibility due to is reduced. From the above, it is effective and desirable to irradiate ultrasonic waves within a conversion rate of 15% to 80%. Further, when the ultrasonic wave irradiation time within the conversion rate range is less than 30 minutes, the effect of improving the pigment dispersibility in the toner particles by the ultrasonic wave irradiation cannot be obtained sufficiently.

  Pressure may be applied to the dispersion of the polymerizable monomer composition during ultrasonic irradiation, and the pressure P (kPa) at this time is preferably in the range of 5 ≦ P ≦ 400. When the pressure is less than 5 kPa, energy due to ultrasonic irradiation is not easily transmitted to the dispersed droplets of the polymerizable monomer composition. When the pressure is higher than 400 kPa, cavitation generated by ultrasonic irradiation is less likely to occur. For this reason, since the pigment dispersion state in the toner particles to be generated is lowered, the pressure is preferably in the range of 5 ≦ P ≦ 400.

  When using a polymerization initiator in order to initiate the polymerization reaction of the polymerizable monomer in the polymerizable monomer composition, it is desirable to add it after preparing a dispersion of the polymerizable monomer composition. This is not preferable because the particle size distribution of toner particles obtained by adding a polymerization initiator before the dispersion of the polymerizable monomer composition and sonicating in the polymerization process is broadened. On the other hand, what prepared the dispersion liquid of the polymerizable monomer composition and added the polymerization initiator is sharp. When a polymerization initiator is added after preparing the dispersion, the initiator acts from the outside of the dispersion droplet of the polymerizable monomer composition. For this reason, it is speculated that the polymerization of the polymerizable monomer proceeds from the outside of the dispersed droplets and the stability of the droplets increases, and the particle size distribution is not easily broken even by ultrasonic irradiation.

  The method for producing toner particles of the present invention can also be preferably used for a method for producing magnetic toner particles. For example, a magnetic material used for producing magnetic toner particles in a wet granulation method using a suspension polymerization method will be described below.

  The surface of the magnetic material used in the magnetic toner is preferably hydrophobized. When hydrophobizing the magnetic material, it is very preferable to use a method in which the surface treatment is carried out while hydrolyzing the coupling agent while dispersing the magnetic material particles as primary particles in an aqueous medium. In this hydrophobization method, the magnetic particles are less likely to coalesce than in the gas phase, and the magnetic repulsion action between the magnetic particles due to the hydrophobization treatment works, so the magnetic material is almost in the state of primary particles. Surface treatment with.

  The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates gas, such as chlorosilanes and silazanes. In addition, since the magnetic particles can be easily united in the gas phase so far, it is possible to use a highly viscous coupling agent that has been difficult to perform well, so the effect of hydrophobization is tremendous. It is.

  Examples of the coupling agent that can be used in the surface treatment of the magnetic material according to the present invention include a silane coupling agent and a titanium coupling agent.

  Further, the magnetic material can be suitably used as a colorant contained in the toner particles, but as a colorant other than the above magnetic material that can be suitably used in the toner produced in the present invention, carbon black and the following And yellow / magenta / cyan colorants shown in FIG.

  As a colorant suitable for the yellow color, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, 191 and C.I. I. Bat yellow 1, 3, 20, etc. Examples of the dye include C.I. I. Solvent yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162 etc. are mentioned. These may be used alone or in combination of two or more.

  As a colorant suitable for magenta, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48; 2, 48; 3, 48; 4, 49, 50, 51, 52, 53, 54, 55, 57, 57; 1, 58, 60, 63, 64, 68, 81, 81; 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, etc., C.I. I. Pigment violet 19; C.I. I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35, etc. Examples of the dye include C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122, etc. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27 etc., C.I. I. Oil-soluble dyes such as disperse violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, etc. I. Basic violet 1,3,7,10,14,15,21,25,26,27,28 etc. basic dyes etc. are mentioned. These may be used alone or in combination of two or more.

  As a colorant suitable for cyan, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66, etc., C.I. I. Bat Blue 6, C.I. I. Acid Blue 45. Examples of the dye include C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. are mentioned. These may be used alone or in combination of two or more.

  These colorants can be used singly or in combination of two or more, or can be used in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. For example, in the case of the wet granulation method by the suspension polymerization method, the colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  The toner particles produced in the present invention may contain a release agent. Examples of the release agent that can be used for the toner particles in the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method, polyethylene And natural waxes and derivatives thereof such as carnauba wax and candelilla wax, which include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like can also be used.

  Specific examples of the wax that can be used as a release agent include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries); High wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals); Sazol H1, H2, C80, C105, C77 (Schumann Sazol); HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12, HNP-51 (Nippon Seiki Co., Ltd.); Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.); wood wax, beeswax, rice wax, candelilla wax, carnauba wax ( Available), and the like by a formula company Cerarica NODA.

  A charge control agent may be blended in the toner particles used in the present invention. A well-known thing can be utilized as a charge control agent. Further, for example, in the case of a wet granulation method using a suspension polymerization method, when producing toner particles, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, sulfones Examples thereof include a polymer compound having an acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  As a method of adding a charge control agent to the toner, there are a method of adding it inside the toner particles and a method of adding it externally to the toner particles. The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. When added internally, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. In the case of external addition, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner particles.

  In the present invention, for example, in the case of a wet granulation method by a suspension polymerization method, examples of the polymerizable monomer contained in the toner include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate Class; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide.

  In the toner production method of the present invention, for example, in the case of wet granulation by suspension polymerization, resin may be added to the polymerizable monomer for polymerization. Monomers containing hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, nitrile groups, etc. that cannot be used because they are soluble in aqueous suspension and cause emulsion polymerization. It can be applied when it is desired to introduce a monomer component into the toner. That is, in the form of a random copolymer of these groups and a vinyl compound such as styrene or ethylene, a block copolymer, a copolymer such as a graft copolymer, or a polycondensate such as polyester or polyamide. Or in the form of a polyaddition polymer such as polyether or polyimine.

  In addition, resins other than those mentioned above may be added to the monomer system. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substitution products thereof; 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-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, Styrene-vinyl methyl ether copolymer, styrene Nyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Copolymer: Polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin Aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins and the like can be used alone or in combination.

  The addition amount of these resins is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the monomer. If the amount is less than 1 part by mass, the effect of addition is small, while if it is added more than 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner.

  Further, a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer may be dissolved in the monomer for polymerization.

  In the method for producing a toner of the present invention, when a polymerization initiator is used for initiating a polymerization reaction of a polymerizable monomer, a monomer having a half-life of 0.5 to 30 hours during the polymerization reaction is used. When the polymerization reaction is carried out at an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the monomer, a polymer having a maximum between 10,000 and 100,000 can be obtained. Good melting characteristics. As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene Examples thereof include peroxide polymerization initiators such as hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, and t-butylperoxypivalate.

  When the toner of the present invention is produced, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, and the like; Divinyl aniline, divinyl ether, divinyl sulfide, divinyl sulfone and other divinyl compounds; and compounds having three or more vinyl groups are used alone or as a mixture of two or more.

  A general toner production method by the suspension polymerization method will be described.

  First, pigments, release agents, plasticizers, charge control agents, cross-linking agents, and other components necessary as toners and other additives such as high molecular weight polymers are appropriately added to the polymerizable monomer to uniformly By dissolving or dispersing, a colorant-containing polymerizable monomer composition is obtained. At this time, you may perform temperature control operation as needed. This colorant-containing polymerizable monomer composition is suspended and granulated in an aqueous medium containing a dispersion stabilizer. The feature of the present invention is to use a large-sized ultrasonic apparatus capable of mass production as a means for performing this suspension.

  At this time, the colorant-containing polymerizable monomer composition is granulated at the same time or after granulation, and then the polymerization composition is polymerized by adding a polymerization initiator (polymerization step). The specific timing of addition of the polymerization initiator may be added simultaneously with the addition of other additives in the polymerizable monomer, or may be added and mixed immediately before being suspended in the aqueous medium. . Moreover, a polymerization initiator dissolved in an additional polymerizable monomer or solvent during the polymerization reaction can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed to such an extent that the particle state is maintained and particle floating and sedimentation are prevented by using a normal stirrer while adjusting the temperature.

  Known dispersion stabilizers and organic / inorganic dispersants can be used as dispersion stabilizers for producing the toner particles. Among these, inorganic dispersants are preferred because they are less likely to produce harmful ultrafine powders, and because dispersion stability is obtained due to their steric hindrance, stability is not easily lost even when the reaction temperature is changed. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic salts; inorganic hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; inorganic oxides such as silica, bentonite, and alumina.

  These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by weight with respect to 100 parts by weight of the polymerizable monomer, but 0.001 to 0.1 parts by weight of a surfactant is added. You may use together.

  Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of calcium phosphate, water-insoluble calcium phosphate can be generated by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under ultrasonic irradiation or stirring, or under ultrasonic irradiation and stirring. More uniform and fine dispersion is possible.

  At the same time, a water-soluble sodium chloride salt is produced as a by-product. However, if a water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and an ultrafine toner based on emulsion polymerization is produced. Since it becomes difficult to generate | occur | produce, it is more convenient. The inorganic dispersant can be dissolved with an acid or an alkali after the completion of the polymerization and removed almost completely by the next step such as filtration and washing.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. Further, in order to consume the remaining polymerizable monomer, the reaction temperature can be increased to 90 to 150 ° C. at the end of the polymerization reaction. After completion of the polymerization reaction, the obtained toner particle dispersion is filtered and washed with a suitable solid-liquid separation device, preferably a belt filter, and then dried with a suitable drying device.

  In general, toner particles obtained by removing coarse powder and fine powder out of a desired particle size range in the classification process are obtained. The classification step can be carried out by a known method used in conventional toner production, and is not particularly limited. A toner can be obtained by mixing an external additive such as an inorganic fine powder with the toner particles obtained through the classification step and adhering them to the surface of the toner particles.

  In the present invention, it is one of desirable modes to directly obtain the toner by omitting the classification process from the manufacturing process or to cut coarse powder and fine powder with high precision by performing a more accurate classification process.

  In the present invention, it is also preferable that inorganic fine particles having a number average primary particle diameter of 4 to 80 nm are added to the toner as a fluidizing agent among the external additives.

Silica, alumina, titanium oxide, etc. can be used as the inorganic fine particles used in the present invention. For example, as the silicic acid fine powder, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. some, but less silanol groups on the inner surface and the silica fine powder, also Na ₂ O, SO ₃ ^- it is preferable less dry silica of manufacturing residue such. In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process, They are also included.

  The amount of inorganic fine particles having an average primary particle size of 4 to 80 nm is preferably 0.1 to 3.0% by mass with respect to the toner base particles. If the addition amount is less than 0.1% by mass, the effect is not sufficient, and if it is more than 3.0% by mass, the fixability may be deteriorated. In addition, content of inorganic fine powder can be quantified using the analytical curve created from the standard sample using the fluorescent X ray analysis.

  The inorganic fine particles are preferably hydrophobized in view of characteristics in a high temperature and high humidity environment. As treatment agents for hydrophobic treatment, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds may be used alone or in combination. May be used. As a method for treating the inorganic fine particles, for example, a method of forming a hydrophobic thin film on the surface with silicone oil as a second-stage reaction after performing a silylation reaction as a first-stage reaction to eliminate silanol groups by chemical bonding. Can be mentioned.

The silicone oil may have a viscosity of 10 to 200,000 mm ² / s at 25 ° C., and more preferably from 3,000 to 80,000mm ² / s. If it is less than 10 mm ² / s, the inorganic fine particles are not stable, and the image quality tends to deteriorate due to heat and mechanical stress. If it exceeds 200,000 mm ² / s, uniform processing tends to be difficult.

  As the silicone oil used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable.

  As a method for treating silicone oil, for example, inorganic fine particles treated with a silane compound and silicone oil may be directly mixed using a mixer such as an FM mixer, or a method of spraying silicone oil onto inorganic fine particles. It may be used. Alternatively, after dissolving or dispersing silicone oil in a suitable solvent, inorganic fine particles may be added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of inorganic fine particle aggregates is relatively small.

  The treatment amount of the silicone oil is 1 to 40 parts by mass, preferably 3 to 35 parts by mass with respect to 100 parts by mass of the inorganic fine particles.

Silica used in the present invention, in order to impart good fluidity to the toner, the specific surface area measured by the BET method by nitrogen adsorption of preferably those in the range of 20 to 350m ² / g, 25 to 300 meters ² / g is more preferable.

  In accordance with the BET method, the specific surface area is obtained by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) and calculating the specific surface area using the BET multipoint method.

In addition, the toner of the present invention is a toner having, as an external additive, inorganic or organic spherical fine particles having a primary particle size of more than 30 nm, more preferably 50 nm or more, for the purpose of improving cleaning properties. It is one of the preferable forms to be added to the particles. As the inorganic or organic fine particles, those having a specific surface area of less than 50 m ² / g (more preferably a specific surface area of less than 30 m ² / g) can be preferably used. As such fine particles, for example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  In the toner used in the present invention, other external additives can be further added to the toner particles within a range that does not substantially adversely affect the toner. For example, lubricant powder such as polyfluorinated ethylene powder, zinc stearate powder, polyvinylidene fluoride powder; abrasive such as cerium oxide powder, silicon carbide powder, strontium titanate powder; imparting fluidity such as titanium oxide powder, aluminum oxide powder Agents; anti-caking agents and the like. In addition, a small amount of organic fine particles or inorganic fine particles having a reverse polarity can be used as a developability improver. These external additives can also be used after the surface is hydrophobized.

  The toner that can be produced in the present invention can be used as a one-component developer. For example, as a one-component developer, in the case of a polymerized toner containing a magnetic material in the toner, there is a method of conveying and charging the polymerized toner using a magnet built in the developing sleeve. However, the developer is not necessarily limited to the one-component developer as described above, and may be used as a two-component developer.

  When used as a two-component developer, a magnetic carrier is used together with the toner. As the magnetic carrier, an element selected from iron, copper, zinc, nickel, cobalt, manganese and chromium is used alone or in a composite ferrite state. The magnetic carrier has a spherical shape, a flat shape, or an indeterminate shape. Furthermore, it is preferable to control the fine structure (for example, surface unevenness) of the surface state of the magnetic carrier particles. Generally, after the inorganic oxide is fired and granulated to previously generate magnetic carrier core particles, a method of coating the carrier core particles with a resin is used. For the purpose of reducing the load of the magnetic carrier on the toner, a method of obtaining a low density dispersion carrier by kneading and classifying an inorganic oxide and a resin, or a kneaded product of an inorganic oxide and a monomer directly in an aqueous medium It is also possible to use a method in which suspension polymerization is performed to obtain a true spherical magnetic carrier.

  Among these, a coated carrier obtained by coating the surface of the carrier core particle with a resin is particularly preferable. As a method of coating the surface of the carrier core particles with the resin, the resin is dissolved or suspended in a solvent and applied to the carrier core by coating, or the resin powder and the carrier core particles are mixed and attached. Can be applied.

  When a two-component developer is prepared by mixing the toner used in the present invention and a magnetic carrier, the mixing ratio is such that the toner concentration in the developer is 2 to 15% by mass, preferably 4 to 13% by mass. Usually good results are obtained.

  Measurement of the particle size distribution of toner used in the present invention and calculation of the number variation coefficient will be described.

<Measuring method of weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In 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 bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle size (D4). When the number% is set, the “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

<Calculation method of number variation coefficient>
The coefficient of variation in the number distribution is calculated from the following equation.
Coefficient of variation (%) = [S / D1] × 100
[Wherein S represents a standard deviation in the number distribution of toner particles. ]
Number variation coefficient: Less than 22% A Very good
: 22% or more and less than 26% B Good
: 26% or more and less than 30% C Normal
: Over 30% D Poor

<Calculation method of conversion>
In the present invention, the conversion rate was calculated from the remaining amount of styrene monomer in the polymerizable monomer composition.

  The amount of residual styrene monomer in the polymerizable monomer composition is measured by gas chromatography (GC) as follows.

  About 1000 mg of toner is precisely weighed and placed in a sample bottle. About 15 g of acetone precisely weighed is added to the lid, mixed well, and mixed well. A tabletop ultrasonic cleaner having an oscillation frequency of 42 kHz and an electric output of 125 W (for example, “B2510J-MTH”, manufactured by Branson) ) For 30 minutes. Thereafter, filtration is performed using a solvent-resistant membrane filter “Maesori Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm, and 2 μl of the filtrate is analyzed by gas chromatography. And the residual amount of a residual styrene monomer is computed with the analytical curve created beforehand using styrene.

The measurement apparatus and measurement conditions are as follows.
GC: HP 6890GC
Column: HP INNOWax (200 μm × 0.40 μm × 25 m)
Carrier gas: He (constant pressure mode: 20 psi)
Oven: (1) Hold at 50 ° C. for 10 minutes, (2) Temperature rise to 200 ° C. at 10 ° C./minute, (3) Hold at 200 ° C. for 5 minutes Inlet: 200 ° C., pulsed splitless mode (20 → 40 psi, until 0.5 min)
Split ratio: 5.0: 1.0
Detector: 250 ° C. (FID)

<Image evaluation>
Evaluation method A commercially available LBP-3700 (manufactured by Canon Inc.) was used as an evaluation machine. Also, remove the product toner from the commercially available cyan cartridge, clean the inside by air blow, peel off the resin film laminated on the surface of the toner regulating member, replace the toner carrier as appropriate, and remove the toner of the present invention. With respect to other magenta, yellow, and black cartridges filled with 100 g, the product toner was removed and inserted into each station for evaluation.
・ Image density of 2% printing using Xx75g / m ² paper in H / H (30 ° C, 80% RH) environment and L / L (15 ° C, 10% RH) environment In an image-printing test for printing out up to 10,000 sheets, a solid image was output at the end of durability evaluation, and the density was measured for evaluation. The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co., Ltd.) to measure the relative density with respect to an image of a white background portion having a document density of 0.00.
A: Very good 1.40 or more B: Good 1.25 or more, less than 1.40 C: Normal 1.10 or more, less than 1.25 D: Poor 1.10

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but these do not limit the present invention in any way.

[Example 1]
With respect to 100 parts by mass of the styrene monomer, C.I. I. 15 parts by mass of Pigment Blue 15: 3 and 3.0 parts by mass of an aluminum compound of 3,5-di-tert-butylsalicylic acid [Bontron E88 (manufactured by Orient Chemical Co., Ltd.)] were prepared. These were introduced into a dispersion tank and stirred with a propeller blade to prepare a mixed solution. A part of the prepared mixed solution was sequentially transferred to a media dispersion type disperser SC100 (manufactured by Nippon Coke Kogyo Co., Ltd.) with a circulation pump for dispersion treatment. The mixed solution dispersed in SC100 was returned to the dispersion tank and circulated for 120 minutes to obtain a pigment dispersion. The operating conditions of SC100 at this time are as follows.
・ Rotating rotor peripheral speed: 13 m / s
・ Media diameter: 0.5mm beads (Material: Zirconia)
・ Media filling rate: 95%
・ Back pressure: 0.1 MPa
・ Circulating flow rate: 10 L / min
450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water, heated to 60 ° C. with stirring, and then 1.0 mol / liter-CaCl ₂ aqueous solution 67 .7 parts by mass was added to obtain an aqueous medium containing a calcium phosphate compound.

On the other hand, 40 parts by weight of pigment dispersion, 27.5 parts by weight of styrene monomer, 18.5 parts by weight of n-butyl acrylate monomer, 19 parts by weight of low molecular weight polystyrene (Mw = 3,000, Mn = 1,050) , Tg = 55 ° C.)
Hydrocarbon wax 9 parts by mass (Fischer-Tropsch wax, maximum endothermic peak = 80 ° C., Mw = 750)
Polyester resin 5 parts by mass (bisphenol A-propylene oxide 2 mol adduct: terephthalic acid = 1: 1 polycondensate, Tg = 65 ° C., Mw = 10,000, Mn = 6,000)
-Divinylbenzene 0.01 mass part The said prescription was heated at 60 degreeC, stirring, and it melt | dissolved and disperse | distributed uniformly and adjusted the polymerizable monomer composition.

The polymerizable monomer composition is put into the aqueous medium, and stirred at 10,000 rpm for 25 minutes in a TK homomixer at 65 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer composition. A dispersion of a polymerizable monomer composition was prepared.

  This dispersion was introduced into the polymerization tank of the circulation polymerization system shown in FIG. 2, and the polymerization initiator 1,1,3,3-tetramethylbutylperoxy-2-ethyl was stirred with a full zone stirring blade (manufactured by Shinko Pantech Co., Ltd.). 10 parts by mass of 70% toluene solution of hexanoate was added. Thereafter, the temperature was raised to 67 ° C. 30 minutes after the addition of the polymerization initiator, the dispersion was sequentially sent to the ultrasonic processing chamber by a pump, and an ultrasonic generator (A = 2000 W, A / B = 42) was activated to perform ultrasonic processing. At this time, the dispersion liquid after the ultrasonic treatment was returned to the polymerization tank through a circulation outlet provided in the dispersion liquid in the polymerization tank. At this time, the pressure gauge 5 showed 200 kPa, and was adjusted so that C · T / V = 6. After 50 minutes of ultrasonic treatment in this circulation polymerization system, the ultrasonic generator was stopped (the circulation of the dispersion continued). Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min).

  When the polymerization conversion rate reached 90%, a 0.1 mol / liter sodium hydroxide aqueous solution was added to adjust the pH of the aqueous dispersion medium to 9. Furthermore, it heated up at 80 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 4 hours.

  After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles measured at this time. After cooling, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt. After filtration and washing with water, it was dried at 40 ° C. for 12 hours to obtain cyan toner particles.

  With respect to 100 parts by mass of the toner particles, 1.0 part by mass of hydrophobic silica fine powder surface-treated with hexamethyldisilazane (number average primary particle size: 7 nm), 0.15 part by mass of rutile titanium oxide fine powder ( The number average primary particle size: 30 nm) was dry mixed with an FM mixer FM mixer (Nihon Coke Kogyo Co., Ltd.) for 5 minutes to obtain a toner. Table 1 shows the image evaluation results of the obtained toner.

[Example 2]
The same procedure as in Example 1 was performed until the preparation of the polymerizable monomer composition dispersion.

  The prepared dispersion was introduced into a polymerization tank of the polymerization system shown in FIG. 3 and stirred with a full zone stirring blade (manufactured by Shinko Pantech Co., Ltd.) while polymerization initiator 1,1,3,3-tetramethylbutylperoxy-2-ethyl was added. 10 parts by mass of 70% toluene solution of hexanoate was added. Thereafter, the temperature was raised to 67 ° C. 30 minutes after the addition of the polymerization initiator, an ultrasonic generator (A = 2000W, A / B = 42) was activated to perform ultrasonic treatment. After 50 minutes of ultrasonication in this polymerization system, the ultrasonic generator was stopped. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min).

  When the polymerization conversion rate reached 90%, a 0.1 mol / liter sodium hydroxide aqueous solution was added to adjust the pH of the aqueous dispersion medium to 9. Furthermore, it heated up at 80 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 4 hours.

  After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. The particle size distribution of the toner particles measured at this time is shown in Table 2. After cooling, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt. After filtration and washing with water, it was dried at 40 ° C. for 12 hours to obtain cyan toner particles.

  With respect to 100 parts by mass of the toner particles, 1.0 part by mass of hydrophobic silica fine powder surface-treated with hexamethyldisilazane (number average primary particle size: 7 nm), 0.15 part by mass of rutile titanium oxide fine powder ( The number average primary particle size: 30 nm) was dry mixed with an FM mixer (Nihon Coke Kogyo Co., Ltd.) for 5 minutes to obtain the toner of the present invention. Table 1 shows the image evaluation results of the obtained toner.

Example 3
Toner particles were produced under the same conditions and method as in Example 1 except that a vibrator having an output A (W) / vibration irradiation area B (cm ² ) per ultrasonic generator of 80 was used. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 4
Toner particles were produced under the same conditions and method as in Example 1, except that a vibrator having an output A (W) per ultrasonic generator / vibration irradiation area B (cm ² ) of 70 was used. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 5
Toner particles were produced under the same conditions and method as in Example 1 except that a vibrator having an output A (W) per ultrasonic generator / vibration irradiation area B (cm ² ) of 25 was used. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 6
Toner particles were produced under the same conditions and method as in Example 1 except that a vibrator having an output A (W) per unit of ultrasonic generator / vibration irradiation area B (cm ² ) of 15 was used. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 7
Example except that an ultrasonic generator having an output A of 1600 W was used and a vibrator having an output A (W) / vibration irradiation area B (cm ² ) of 19 per ultrasonic generator was used. Toner particles were produced under the same conditions and method as in Example 1, and a toner was obtained by the same method as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 8
Circulation flow rate C (l / min) of dispersion liquid × Sonication time T (min) / Total liquid volume V (l) of dispersion liquid
A toner particle was produced by the same conditions and method as in Example 1 except that the circulation flow rate was adjusted so that the value of was 2 and a toner was obtained by the same method as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 9
Toner particles were produced under the same conditions and method as in Example 1 except that the dispersion liquid was circulated and ultrasonic irradiation was performed simultaneously with the addition of the polymerization initiator, and ultrasonic treatment was performed for 40 minutes. A toner was obtained by the same method. The conversion rate after 15 minutes from the start of ultrasonic irradiation was 15%. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 10
After addition of the polymerization initiator, toner particles were produced under the same conditions and method as in Example 1, except that the circulation of the dispersion and the irradiation of ultrasonic irradiation were started after 100 minutes, and the ultrasonic treatment was performed for 45 minutes. A toner was obtained in the same manner as in Example 1. The conversion rate after the lapse of 118 minutes from the start of ultrasonic irradiation was 80%. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 11
Simultaneously with the addition of the polymerization initiator, circulation of the dispersion and irradiation of ultrasonic irradiation are started, and ultrasonic treatment is performed for 15 minutes. Toner particles are produced under the same conditions and method as in Example 1 except that the circulation flow rate is adjusted so that the total liquid volume V (l) of the dispersion is 2.3. The same method as in Example 1 A toner was obtained. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 12
After addition of the polymerization initiator, the toner particles were produced under the same conditions and method as in Example 1 except that the dispersion liquid was circulated and ultrasonic irradiation was started after the elapse of 140 minutes and the ultrasonic treatment was performed for 50 minutes. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 13
After addition of the polymerization initiator, toner particles were produced under the same conditions and method as in Example 1, except that the dispersion liquid was circulated and ultrasonic irradiation was started after 17 minutes and ultrasonic treatment was performed for 30 minutes. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 14
After addition of the polymerization initiator, toner particles were produced under the same conditions and method as in Example 1, except that the dispersion liquid was circulated and ultrasonic irradiation was started after 90 minutes and ultrasonic treatment was performed for 30 minutes. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 15
A separately prepared polymerizable monomer composition was put into an aqueous medium, stirred at 10,000 rpm with a TK homomixer at 65 ° C. in an N ₂ atmosphere, and after 15 minutes from the start of stirring, a polymerization initiator Was added. After addition of the polymerization initiator, the mixture was further stirred for 10 minutes to granulate the polymerizable monomer composition to prepare a dispersion of the polymerizable monomer composition. Furthermore, Example 1 was carried out except that after the introduction of the dispersion prepared by the above method into the polymerization tank was completed, the mixture was stirred for 5 minutes, and then the dispersion was circulated and ultrasonic irradiation was started and sonication was performed for 50 minutes. Toner particles were produced under the same conditions and method as in Example 1, and a toner was obtained by the same method as in Example 1.

  Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min).

  Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 16
Toner particles were produced under the same conditions and method as in Example 1 except that the opening of the back pressure valve was adjusted and the indicated value of the pressure gauge was 400 kPa. Toner was obtained by the same method as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 17
Except for adjusting the opening of the back pressure valve and setting the indicated value of the pressure gauge to 5 kPa, toner particles were produced under the same conditions and method as in Example 1, and toner was obtained by the same method as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 18
Toner particles were produced under the same conditions and method as in Example 1 except that a circulation outlet was installed in the gas phase part of the polymerization tank and the ultrasonically treated dispersion was discharged into the gas phase part. A toner was obtained by the same method. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

Example 19
A separately prepared polymerizable monomer composition was put into an aqueous medium, stirred at 10,000 rpm with a TK homomixer at 65 ° C. in an N ₂ atmosphere, and after 15 minutes from the start of stirring, a polymerization initiator Was added. After addition of the polymerization initiator, the mixture was further stirred for 10 minutes to granulate the polymerizable monomer composition to prepare a dispersion of the polymerizable monomer composition. Further, after the addition of the polymerization initiator, the dispersion liquid was circulated and ultrasonic irradiation was started after 150 minutes, and ultrasonic treatment was performed for 50 minutes. At this time, the opening of the back pressure valve is adjusted so that the indicated value of the pressure gauge is 5 kPa,
Circulation flow rate C (l / min) of dispersion liquid × Sonication time T (min) / Total liquid volume V (l) of dispersion liquid
A toner particle was produced by the same method and method as in Example 18 except that the value of was set to 1.5, and a toner was obtained by the same method as in Example 1.

  Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

[Comparative Example 1]
Production of toner particles under the same conditions and method as in Example 1 except that the ultrasonic generator (A = 2000 W, A / B = 100) having the shape shown in FIG. 4 is incorporated in the circulation polymerization system shown in FIG. Then, a toner was obtained by the same method as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

[Comparative Example 2]
Toner particles were produced under the same conditions and method as in Example 2 except that the ultrasonic generator (A = 2000 W, A / B = 100) having the shape shown in FIG. 4 was incorporated in the polymerization system shown in FIG. A toner was obtained in the same manner as in Example 1. Table 1 shows the conversion rate at the start and end of ultrasonic irradiation, and the conversion rate from 15% to 80% ultrasonic treatment time t (min). Table 2 shows the weight average particle diameter (D4) and the number variation coefficient of the toner particles when the residual monomer was distilled off, and the image evaluation results of the obtained toner.

  DESCRIPTION OF SYMBOLS 1 Ultrasonic generator suitable for this invention, 2 Ultrasonic vibrator suitable for this invention, 3 Ultrasonic irradiation part suitable for this invention, 4a, 4b Thermometer, 5a, 5b Pressure gauge, 6 Circulation discharge port, 7 Stirring blade, 8 Stirring motor, 9 Polymerization tank, 10 Pump, 11 Granulation tank, 12 Circulation line, 13 Conventional ultrasonic generator, 14 Conventional ultrasonic transducer, 17 Conventional ultrasonic irradiation unit, 18 Piping , 19 Ultrasonic treatment chamber, 20 Back pressure valve

Claims (5)

Production of toner particles including at least a polymerization step of polymerizing a polymerizable monomer in a dispersion obtained by dispersing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium A method,
In the polymerization step, the ultrasonic wave generation has a vibrator for irradiating an ultrasonic wave having a convex portion in the circumferential direction of the cylinder, and the convex portion is a convex portion forming a concentric circle with respect to the cylinder. A method for producing toner particles, wherein ultrasonic treatment is performed to vibrate the vibrator of the apparatus.   The ultrasonic treatment is performed by feeding the dispersion liquid from a polymerization tank containing the dispersion liquid to an ultrasonic generator provided outside the polymerization tank, ultrasonic treatment of the dispersion liquid, 2. The method for producing toner particles according to claim 1, wherein the toner particles are continuously circulated to the polymerization tank. In the polymerization step, when A (W) is an output per ultrasonic generator and B (cm ² ) is an ultrasonic irradiation area per ultrasonic generator, A ≧ 2000 and A The toner production method according to claim 1, wherein / B is in a range of 25 ≦ A / B ≦ 70.   In the polymerization step, C · T / V ≧ 2 when the total liquid volume V (l) of the dispersion liquid, the circulation flow rate C (l / min) of the dispersion liquid, and the ultrasonic treatment time T (min). The method for producing toner particles according to any one of claims 1 to 3, wherein the toner particles are produced.   In the polymerization step, at least the conversion rate of the polymerizable monomer in the dispersion is sonicated within a range of 15% or more and 80% or less, and the sonication time t ( The method for producing toner particles according to claim 1, wherein min) is in a range of 30 ≦ t.

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