JP2008040055A - Aggregation type polymerized toner and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method where the particle size distribution and charging properties of aggregation type polymerized toner produced by an aggregation process from a resin particle-dispersed liquid and a coloring agent particulate-dispersed material formed by aggregation polymerization are made uniform. <P>SOLUTION: The method for producing aggregation type polymerized toner is characterized in that, in a method for producing aggregation type polymerized toner obtained by aggregating a resin particle-dispersed liquid and a coloring agent particle-dispersed liquid, the resin particle-dispersed liquid is formed by an emulsion polymerization process using acid monomers, and thereafter, the reaction liquid is cooled at a cooling velocity of ≥¾30°C/min¾. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an associative toner, and more particularly, to a method for preparing a resin particle dispersion used in a method for producing an associative polymerized toner and an associative polymer toner formed using the same.

  In recent years, with the progress of color and speedup of copiers, the electrophotographic industry demands low-cost, high-quality and environmentally friendly toners. In order to satisfy this requirement, conversion from conventional pulverized toner to chemical toner is progressing. Various methods for producing chemical toners have been studied, and products are marketed by several methods. Among these, toners produced by an emulsion polymerization association method (see, for example, Patent Documents 1 and 2) are superior in cost, image quality, and environmental safety compared to conventional pulverized toners. However, due to the cost reduction of copiers and printers equipped with toner, the demand for toner characteristics for obtaining high image quality has increased.

  In the toner of the emulsion polymerization association method, if a machine equipped with toner is used for a long time, the inside of the machine may be contaminated by toner scattering from the developing machine, and image quality may be further deteriorated. As a cause of this, it is generally considered that when an image is output continuously for a long time, a part of the toner having a low charge amount stays in the developing cartridge and rises like a smoke.

  Further, even if there is little toner scattering in the apparatus, white spots may occur on the image. This is presumably because there are particles in the toner that are about 10 to 20 μm larger than the average particle diameter of the toner so that they are not detected by the particle size distribution analyzer.

  The cause of both problems is thought to be due to the non-uniformity of the particles at the time of association.

  As a method for improving the non-uniformity of the toner, as a method for making the association of the resin particle dispersion and the colorant dispersion uniform, a technique for stabilizing the association conditions (for example, see Patent Document 3) is disclosed. . Moreover, as a method for stabilizing the association, a method for preparing a resin particle dispersion or a colorant dispersion (see, for example, Patent Documents 4, 5, and 6) is disclosed.

However, there are variations in the reaction at the time of association, variations in the particle size distribution and the chargeability of the finished toner, and there are problems of scattering fogging and white spots in the image, which have not been solved yet.
JP 2002-116574 A JP 2002-351142 A JP 11-60739 A Japanese Patent Laid-Open No. 10-265512 JP 2000-29240 A JP 7-331111 A

  An object of the present invention is to provide a production method for making uniform the particle size distribution and charging characteristics of an associative polymerization toner produced by an association method of a resin particle dispersion formed by emulsion polymerization and a colorant fine particle dispersion. is there.

  The above problem could be solved by the following configuration.

  1. In a method for producing an associative toner obtained by associating a resin particle dispersion and a colorant particle dispersion, after the resin particle dispersion is formed by an emulsion polymerization method containing an acidic monomer, the temperature of the reaction solution is set to | 30. A method for producing an associative polymerization toner, wherein the toner is cooled at a cooling rate of at least ° C / min |.

  2. 2. The method for producing an associative polymerization toner according to 1 above, wherein the cooling start temperature of the reaction liquid is in the range of Tg + 10 ° C. to Tg + 70 ° C. of the resin.

  3. 3. The method for producing an associative polymerization toner according to 1 or 2 above, wherein the reaction solution has a cooling temperature in the range of 10 to 30 ° C.

  4). 4. The method for producing an association-type polymerization toner according to any one of 1 to 3, wherein the reaction liquid is cooled by a heat exchange system.

  5. 5. The method for producing an association-type polymerized toner according to any one of 1 to 4, wherein a throughput of the heat exchange system is 100 to 500 kg / min.

  6). 6. An associative polymerized toner formed by the method for producing an associative polymer toner according to any one of 1 to 5 above.

  According to the present invention, in the method for producing an association polymerization toner of a resin particle dispersion and a colorant fine particle dispersion, after the resin particle dispersion is formed by an emulsion polymerization method containing an acidic monomer, the temperature of the reaction solution is set as much as possible. It has been found that by rapidly cooling to the storage temperature, the uniformity in the subsequent process of the colorant fine particle dispersion and the fusing process is improved, and the uniformity of the formed polymerized toner is greatly improved. Is.

  Hereinafter, the present invention will be described in detail.

  The production method of associative polymerization toner is to prepare a resin particle dispersion and a colorant particle dispersion to be associated in advance, mix them in predetermined amounts, and then add the associative solution while stirring (this is referred to as this). In the invention, it is called an associating liquid.) Then, heating is performed to gradually associate and fuse, and when a predetermined particle size is obtained, a stopper is added to terminate the association, cooling is performed, and melting is performed. The toner particles are obtained by collecting the adhered particles and drying them.

  In the present invention, after the resin particle dispersion to be associated is formed by an emulsion polymerization method containing an acidic monomer, the temperature of the reaction liquid is cooled to the storage temperature as quickly as possible, whereby the subsequent resin particle dispersion and colorant It has been found that the association of the particle dispersion proceeds uniformly, the particle size of the formed particles is uniform, and the properties of the obtained toner are uniform and good.

  In addition, although it is not certain about these mechanisms, by rapidly cooling the temperature of the resin particle dispersion after the reaction, the surface state of the resin particles has a more or less polar group orientation state than that gradually cooled. It is presumed that it has had a positive effect on the subsequent meeting process.

  Hereinafter, the production method of the association polymerization toner will be described in more detail.

[Toner Production Method]
The associative polymerization toner of the present invention can be produced by the following method.

  The toner according to the present invention is produced by a process of associating and fusing a resin particle dispersion and a colorant particle dispersion in an aqueous medium. For example, an emulsion of necessary additives is added. The emulsion is polymerized in a liquid (in an aqueous medium) or the polymerization according to the mini-emulsion method is performed to prepare a fine resin particle dispersion, and the separately prepared colorant particle dispersion is charged as necessary. After adding controllable resin particles and the like, the resin particles are produced by a method of aggregating and fusing the resin particles by adding an aggregating agent such as an organic solvent and salts.

  A coagulant with a critical coagulation concentration or higher is added for salting out, and at the same time, the formed polymer itself is heated and fused at a temperature above the glass transition temperature to gradually grow the particle size while forming fused particles. When the particle size is reached, a large amount of water is added to stop particle size growth, and the shape is controlled by smoothing the particle surface while heating and stirring, and the particles are heated and dried in a fluidized state while containing water. As a result, the associative polymerization toner of the present invention can be formed. Here, a solvent that is infinitely soluble in water may be added simultaneously with the flocculant.

  Moreover, it is preferable that the glass transition temperature of a resin particle is 40-70 degreeC, and a softening point is 80-140 degreeC.

  In the present invention, a polymerizable monomer containing an acidic monomer is prepared in a water-based medium by preparing a resin particle dispersion by an emulsion polymerization method, and then the reaction liquid is cooled to room temperature as quickly as possible. The present inventors have found that a uniform reaction can be performed in the process of associating with the dispersion and fusing.

  The step of forming resin particles by emulsion polymerization in the present invention may be carried out by using a conventionally used emulsion polymerization method. Usually, the reaction temperature is in the range of Tg to Tg + 50 ° C. of the resin to be formed. The cooling start temperature of the present invention means a temperature in the vicinity of the reaction end temperature, and the cooling attainment temperature is a normal storage temperature and is usually in the range of 10 to 30 ° C.

  As a means for cooling as quickly as possible from the reaction temperature to room temperature used in the present invention, cooling is performed by a heat exchange system, and the cooling rate is heat having a cooling capacity of | 30 ° C./min | An exchange system is preferable, and a heat exchange system having a cooling capacity of | 50 ° C. to 100 ° C./min | is preferably used.

  At a cooling rate of less than | 30 ° C./min |, the resin shrinks when it transitions to the glass state, but the polar groups on the surface are convoluted accordingly, and the repulsive force between the particles decreases, and the post-process The association reaction proceeds too much and becomes non-uniform, and when it exceeds | 100 ° C./min |, the shrinkage is too fast to follow the polar group on the surface, and the repulsive force between particles increases due to the open state. The post-association reaction does not proceed and becomes non-uniform. In either case, the toner particle size distribution / chargeability distribution is adversely affected.

There are various types of heat exchange systems such as a multi-tube cylindrical type, a spiral plate type, a double-pipe type, and a plate type. Generally, the cooling capacity depends on the heat transfer area, material, and cooling medium. Although it is a numerical value serving as an index and is related to the amount of treatment, it is preferable to select 30 m ² or more, and the material is preferably SUS from the viewpoint of thermal conductivity and durability. In order to gain this heat transfer area, the liquid to be cooled passes through the bottleneck, but the liquid to be cooled according to the present invention is a reaction liquid containing resin fine particles, and the flow gap is A devised type is preferred. For example, a wide gap type heat exchanger is preferable for the plate type.

  Next, materials used for preparing the resin particle dispersion will be described.

  As the polymerizable monomer used to obtain the resin particles, a radical polymerizable monomer is an essential constituent, and at least one radical polymerizable monomer having an acidic polar group (referred to as an acidic monomer) is included. However, if necessary, a crosslinkable monomer (crosslinking agent) and a radically polymerizable monomer having a basic group can be used.

(1) Radical polymerizable monomer:
The radical polymerizable monomer is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Moreover, it can be used combining 1 type (s) or 2 or more types so that the required characteristic may be satisfy | filled.

  Specifically, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogenated olefin monomers, and the like can be used. .

  Examples of the aromatic vinyl monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, and pn. -Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2,4- Examples thereof include styrene monomers such as dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, Examples include hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of vinyl ether monomers include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of monoolefin monomers include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene, and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

(2) Radical polymerizable monomer having an acidic polar group:
The radical polymerizable monomer having an acidic polar group includes an α, β-ethylenically unsaturated compound having a carboxyl group (—COOH) and an α, β-ethylenically unsaturated compound having a sulfonic acid group (—SO ₂ OH). Can be mentioned.

  Examples of the α, β-ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester, and these Metal salts such as sodium (Na) and zinc (Zn).

  Examples of the α, β-ethylenically unsaturated compound having a sulfonic acid group include sulfonated styrene and a sodium salt thereof, allylsulfosuccinic acid, octyl allylsulfosuccinate, and a sodium salt thereof.

(3) Crosslinkable monomer:
As the crosslinkable monomer, a radical polymerizable crosslinking agent may be added in order to improve the properties of the finally obtained toner. Examples of the radically polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(4) Radical polymerizable monomer having a basic polar group:
As the radical polymerizable monomer having a basic polar group, (a) (meth) of an aliphatic alcohol having 1 to 12, preferably 2 to 8, particularly preferably 2 carbon atoms having an amine group or a quaternary ammonium group. Acrylic acid ester, (b) (meth) acrylic acid amide or (meth) acrylic acid amide mono- or dialkyl-substituted with an alkyl group having 1 to 18 carbon atoms optionally on N, (c) N as ring member Examples thereof include vinyl compounds substituted with a heterocyclic group having (d) N, N-diallyl-alkylamine or a quaternary ammonium salt thereof, among which the amine group or quaternary ammonium group of (a) A monomer in which the (meth) acrylic acid ester of an aliphatic alcohol having a basic polar group is preferred.

  (A) Examples of (meth) acrylic acid esters of aliphatic alcohols having amine groups or quaternary ammonium groups include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and the above four compounds. A quaternary ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, etc. are mentioned.

  (B) (Meth) acrylic acid amide or (meth) acrylic acid amide optionally mono- or dialkyl-substituted on N includes, for example, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butyl methacrylamide, N, N-dimethyl acrylamide, N-octadecyl acrylamide, etc. are mentioned.

  (C) Examples of the vinyl compound substituted with a heterocyclic group having N as a ring member include vinylpyridine, vinylpyrrolidone, vinyl-N-methylpyridinium chloride, vinyl-N-ethylpyridinium chloride, and the like.

  (D) Examples of N, N-diallyl-alkylamine include N, N-diallylmethylammonium chloride and N, N-diallylethylammonium chloride.

  A known chain transfer agent can be used for the purpose of adjusting the molecular weight of the resin particles.

  The chain transfer agent is not particularly limited, and for example, a mercapto compound having a mercapto group such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, etc. is used. A mercapto compound having a short molecular chain is preferably used because a toner with a sharpness is obtained and storage stability, fixing strength and offset resistance are excellent.

  Specifically, preferable examples of the chain transfer agent include propyl thioglycolate, octyl thioglycolate, mercaptopropionic acid n-octyl ester, and octyl mercaptan.

  In the present invention, any radical polymerization initiator may be used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salts, etc.), A peroxide compound etc. are mentioned.

  Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator. By using a redox initiator, the polymerization activity is increased, so that the polymerization temperature can be lowered and the polymerization time can be further shortened.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, and for example, a range of 50 ° C to 90 ° C is used. However, in the case of using a polymerization initiator that starts at room temperature, for example, a hydrogen peroxide-reducing agent (ascorbic acid or the like) combination, it is possible to polymerize at room temperature or higher.

  In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is preferable to perform oil droplet dispersion in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used here, The following ionic surfactant can be mentioned as an example of a suitable thing.

  Examples of ionic surfactants include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, etc.), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate) Beam, calcium oleate and the like).

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc.

[Manufacture of colorant fine particles]
The colorant fine particle dispersion used for obtaining the toner of the present invention is formed by using a dispersing apparatus for finely dispersing the colorant fine particles in an aqueous medium containing a surfactant. That is, as a dispersing device, a shearing force is generated by a screen that forms a stirring chamber and a rotor that rotates at a high speed in the stirring chamber, and the action of the shearing force (in addition, collision force, pressure fluctuation, cavitation, potential core By the action), the colorant is finely dispersed in an aqueous medium containing a surfactant to obtain fine particles.

  Here, the “aqueous dispersion medium” refers to a medium composed of 50% by mass to 100% by mass of water and 0% by mass to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, tetrahydrofuran, and the like, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable. Further, the volume average particle diameter of the colorant dispersed in a fine particle form in the aqueous dispersion medium can be measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

  Here, the surfactant contained in the aqueous medium in which the colorant fine particles are dispersed is dissolved at a concentration equal to or higher than the critical micelle concentration (CMC), and the surfactant used is used in the polymerization step. The same one can be used.

  The volume average particle size (dispersed particle size) of the colorant fine particles is preferably 0.01 to 0.25 μm.

[Colorant]
As the colorant, carbon black, a magnetic material, a dye, a pigment, and the like can be arbitrarily used. As the carbon black, channel black, furnace black, acetylene black, thermal black, lamp black, and the like are used. Magnetic materials include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, a kind of alloy called Heusler alloy such as manganese-copper-aluminum and manganese-copper-tin, chromium dioxide, and the like can be used.

  Examples of the colorant for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48; 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the colorant for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. And CI Pigment Yellow 138.

  Further, as a colorant for green or cyan, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15; 2, C.I. I. Pigment blue 15; 3, C.I. I. Pigment blue 15; 4, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. Pigment blue 66, C.I. I. And CI Pigment Green 7.

  These colorants may be used alone or in combination of two or more as required. The addition amount of the colorant is set in the range of 1 to 30% by mass, preferably 2 to 20% by mass with respect to the whole toner.

[Other additives]
For example, an offset preventive agent, a fluidizing agent, a cleaning aid, a charge control agent and the like may be added to the toner of the present invention.

  Various waxes can be used as an anti-offset agent used to improve toner fixing properties, especially polyolefin waxes such as low molecular weight polypropylene, polyethylene, oxidized polypropylene, oxidized polyethylene, and carnauba wax. The natural wax is preferably used. The offset inhibitor is added in an amount of 1 to 15 parts by weight, preferably 2 to 8 parts by weight, based on 100 parts by weight of the binder resin.

  The charge control agent is not particularly limited as long as it can give positive or negative charge by frictional charging, and various organic or inorganic substances are used.

  Examples of the positive charge control agent include azine compound nigrosine base EX, Bontron N-01, 02, 04, 05, 07, 09, 10, 13 (manufactured by Orient Chemical Co., Ltd.), oil black (manufactured by Chuo Synthetic Chemical Co., Ltd.) , Quaternary ammonium salt P-51, polyamine compound P-52, Sudan Chief Schwarz BB (Solvent Black 3: CI No. 26150), Fettschwarz HBN (CI No. 26150), Brilliant Spirits Schwarz TN (manufactured by Farben Fabricen Bayer), alkoxylated amines, alkylamides, molybdate chelate pigments, imidazole compounds, and the like can be used.

  As the negative charge control agent, for example, chromium complex salt type azo dyes S-32, 33, 34, 35, 37, 38, 40 (manufactured by Orient Chemical Industries), Eisenspiron Black TRH, BHH (manufactured by Hodogaya Chemical Co., Ltd.) ), Kayaset Black T-22,004 (manufactured by Nippon Kayaku Co., Ltd.), copper phthalocyanine-based dye S-39 (manufactured by Orient Chemical Industries), chromium complex E-81, 82 (manufactured by Orient Chemical Industries), zinc complex E-84 (manufactured by Orient Chemical Co., Ltd.), aluminum complex salt E-86 (manufactured by Orient Chemical Co., Ltd.), calixarene compounds and the like can be used.

  These charge control agents are added in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the binder resin.

  Further, a fluidizing agent or a cleaning aid may be mixed with the toner as the post-processing fine particles.

  As a fluidizing agent, silica, aluminum oxide, titanium oxide, magnesium fluoride, silicon carbide, boron carbide, titanium carbide, zirconium carbide, titanium nitride, zirconium nitride, magnetite, molybdenum disulfide, aluminum stearate, magnesium stearate, Various inorganic fine particles such as zinc stearate are used alone or in combination. As these fine particles, it is desirable to use those which have been hydrophobized with a hydrophobizing agent such as a silane coupling agent, a titanium coupling agent, a higher fatty acid, or silicon oil. In particular, it is preferable to use a combination of two types of the above-mentioned inorganic fine particles hydrophobized for full-color toner, and it is particularly preferable to use silica and aluminum oxide or silica and titanium oxide after hydrophobizing.

  Cleaning aids include inorganic fine particles described above as fluidizing agents, metal soaps such as stearates, fluorine-based, silicon-based, styrene-based, acrylic-based, styrene- (meth) acryl-based, benzoguanamine, melamine, epoxy, etc. Various synthetic resin fine particles are used.

  The post-treatment agent is added in an amount of 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the binder resin.

  The toner obtained as described above may be used as a one-component developer or as a two-component developer together with a carrier.

[Carrier]
As the carrier, those usually used such as an iron powder carrier, a ferrite carrier, a coating carrier, and a binder type carrier can be used.

  Specifically, as a ferrite carrier material, an alloy of a metal such as iron, nickel or cobalt and a metal such as zinc, antimony, aluminum, lead, tin, bismuth, beryllium, manganese, selenium, tungsten, zirconium or vanadium or Examples thereof include mixtures, oxides, metal oxides such as titanium oxide and magnesium oxide, nitrides such as chromium nitride and vanadium nitride, mixtures with carbides such as silicon carbide and tungsten carbide, ferromagnetic ferrites, and mixtures thereof. .

  As the coating carrier, those coated with various synthetic resins or ceramic layers using iron or ferrite as a core material are used. Examples of synthetic resins include polystyrene resins, poly (meth) acrylic resins, polyolefin resins, polyamide resins, polycarbonate resins, polyether resins, polysulfonic acid resins, polyester resins, epoxy resins, Various thermoplastic resins such as polybutyral resins, urea resins, urethane / urea resins, silicone resins, polyethylene resins, Teflon (registered trademark) resins, thermosetting resins and mixtures thereof, and these resins Copolymers, block polymers, graft polymers, polymer blends, and the like are used. Furthermore, a resin having various polar groups may be used to improve the chargeability. Further, various organic and / or inorganic materials may be dispersed and / or dissolved in order to improve the chargeability and various other developer properties, and these materials may be fixed on the coating carrier surface. A thing may be used.

  The ceramic coating is obtained by coating various ceramic materials by a thermal spraying method, various plasma methods, a sol-gel method, or the like.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
(Example of production of resin particles for toner)
(Adjustment of polymerized particles) Mw = 13,000 Dissolve 0.71 parts by mass of sodium dodecylbenzenesulfonate in 323 parts by mass of ion-exchanged water in a reaction kettle equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introducing unit. The prepared surfactant solution (aqueous medium) was charged, and the internal temperature was raised to 83 ° C. while stirring at a stirring speed of 70 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution in which 1.2 parts by mass of potassium persulfate was dissolved in 28 parts by mass of ion-exchanged water was added, the temperature was set to 85 ° C., and the following monomer mixture was added for 3 hours. The polymerization was carried out by heating and stirring the system at 85 ° C. for 1 hour.

Styrene 65.0 parts by mass n-butyl acrylate 15.5 parts by mass MAA80 (20% water-containing methacrylic acid) 04.2 parts by mass n-octyl mercaptan 04.9 parts by mass Thereafter, reaction kettle until 85 ° C to 72 ° C In the inside, cold water is allowed to flow through the jacket and gradually cooled (decrease at 1 ° C./min), and the reaction solution is transferred from the kettle to the storage tank with a plate heat exchange system (heat transfer area: 67 m ² , material: SUS316). While being transported by piping (75 L / min), it was rapidly cooled to 30 ° C. (31 ° C./min), and the latex was stored in a storage tank (held at 30 ° C.). This latex is referred to as “latex (1HML)”. The composite resin particles had a weight average particle size of 105 nm (measured with a particle size distribution measuring apparatus MICROTRAC UPA manufactured by Nikkiso Co., Ltd.) and a glass transition point (Tg) of 62 ° C.

<< Measurement of Glass Transition Point (Tg) of Composite Resin Particle >>
It measured using DSC-7 differential scanning calorimeter (made by Perkin Elmer).

  As a measurement procedure, 4.5 mg to 5.0 mg of composite resin particles are precisely weighed to two decimal places, sealed in an aluminum pan (KITNO.0219-0041), and set in a DSC-7 sample holder. The reference used an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and heat-cool-heat temperature control. Analysis was performed based on the data in Heat.

  The glass transition temperature draws an extension of the baseline before the rise of the first endothermic peak and a tangent line indicating the maximum slope between the rise of the first peak and the peak apex, and the intersection is taken as the glass transition point. Show.

(Dispersion of colorant)
(cyan)
100 parts by mass of a disodium surfactant dodecyl sulfate manufactured by Kao Corporation was dissolved in 627 parts by mass of ion-exchanged water with stirring. While stirring this solution, 280 parts by mass of LINOL BLUE 7334E-P-FD (solid content 45%) manufactured by Toyo Ink Co., Ltd. was gradually added, and then a dispersion device “SC Mill” (manufactured by Mitsui Mining Co., Ltd.) A dispersion liquid of colorant particles (hereinafter referred to as “colorant dispersion liquid 1”) was prepared by performing a dispersion treatment using The particle diameter of the colorant particles in this colorant dispersion liquid 1 was 235 nm as measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). (Measured with Nikkiso Co., Ltd. particle size distribution measuring device MICROTRAC UPA)
(Aggregation / Fusion) Association Latex 1 HML 126 parts by mass, ion-exchanged water 200 parts by mass, and “colorant dispersion 1” 9.5 parts by mass were attached with a temperature sensor, a cooling tube, a nitrogen introduction device, and a stirring device. The reaction vessel was stirred. After adjusting the temperature in the container to 30 ° C., 1 mol / L sodium hydroxide aqueous solution was added to this solution to adjust the pH to 9.5.

  Next, an aqueous solution in which 3.3 parts by mass of magnesium chloride hexahydrate was dissolved in 3.3 parts by mass of ion-exchanged water was added at 30 ° C. over 10 minutes with stirring. After standing for 3 minutes, the temperature increase was started and the system was heated to 88 ° C. over 60 minutes. In this state, the particle size of the associated particles was measured with “Coulter Multisizer III”. When the volume average median diameter reached 6.55 μm, 16.5 parts by mass of sodium chloride was changed to 66 parts by mass of ion-exchanged water. The dissolved aqueous solution was added to stop the particle growth. Further, as the aging treatment, the fusion was continued by heating and stirring at a liquid temperature of 84 ° C. for 5 hours, and then cooling to 30 ° C., and the stirring was stopped. . Colored particles having a median diameter of 6.22 μm on a volume average basis were prepared.

(Washing / drying process)
The associated solution of salting-out, agglomeration and fused particles is adjusted to pH 4 with 1 mol / L hydrochloric acid, filtered, washed repeatedly with ion exchange water at 40 ° C., and then dried with hot air at 40 ° C. As a result, colored particles Cy1 were obtained.

(Production of toner particles)
To the colored particles Cy1 obtained above, 1% by mass of hydrophobic silica (number average primary particle size = 12 nm, hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle size = 20 nm, hydrophobicity = 63) was added and mixed with a Henschel mixer to produce toner 1 of the present invention.

Example 2
Example 1 except that after completion of the polymerization, the latex was stored in a storage tank by rapid cooling (transport: 54 L / min, cooling: 31 ° C./min) using a heat exchange system from 85 ° C. to 30 ° C. Toner 2 of the present invention was produced in the same manner as described above.

Example 3
Example 1 except that after completion of the polymerization, the latex was stored in a storage tank by rapid cooling (transport: 125 L / min, cooling: 72 ° C./min) at a stretch using a heat exchange system from 85 ° C. to 30 ° C. The toner 3 of the present invention was prepared in the same manner as described above.

<< Comparative Example 1 >>
After polymerization is completed, cool water is allowed to flow through the jacket in the reaction kettle from 85 ° C. to 30 ° C., and the water is gradually cooled (decrease at 1 ° C./min), and the reaction solution is transferred from the kettle to the storage tank without passing through the heat exchange system. A comparative toner 1 of the present invention was produced in the same manner as in Example 1 except that it was transported.

  Table 1 shows a comparison of the median diameter (μm) and the coarse powder content (content of 10.1 μm or more) (%) on a volume basis of the toners 1 to 3 and the comparative toner 1.

<Production of developer>
Each of the toner particles shown in Table 1 was mixed with a ferrite carrier having a volume average particle size of 40 μm coated with a silicone resin to prepare Examples 1 to 3 and Comparative Developer 1 having a toner concentration of 8%.

<Measurement of volume-based median diameter (volume D50% diameter) of toner>
Measurement was performed using a device in which a computer system for data processing (manufactured by Beckman Coulter) was connected to Coulter Multisizer III (manufactured by Beckman Coulter).

  After 0.02 g of toner was conditioned with 20 ml of a surfactant solution (a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water), ultrasonic dispersion was performed for 1 minute to disperse the toner. Make a liquid. This toner dispersion is injected into a beaker containing ISOTON II (manufactured by Beckman Coulter) with a pipette until the measured instrument concentration is 5% to 10%. Then, the frequency value is calculated by dividing the range of 1 to 30 μm, which is the measurement range, into 256 divisions by setting the number of measured particle counts to 25,000, the aperture diameter to 50 μm. The particle diameter of 50% from the larger volume integrated fraction is defined as the volume-based median diameter.

<Evaluation of chargeability>
The charge amount of the toner in this sample was measured by a charge amount measuring device “Blow-off type TB-200” (manufactured by Toshiba).

Blow-off charge measuring device (TB-200: manufactured by Toshiba Chemical Co., Ltd.) equipped with a 400 mesh stainless steel screen is blown with nitrogen gas for 10 seconds under the condition of blow pressure 4.9 × 10 ⁴ Pa. The charge amount (μC / g) is calculated by dividing the measured charge by the mass of the flying toner.

  Each developer is left in a high temperature and high humidity environment (temperature: 30 ° C., relative humidity: 80%) and a low temperature and low humidity environment (temperature: 15 ° C., relative humidity: 20%) for 24 hours. After adapting to the environment, the charge amount was measured, and the rank evaluation was performed as follows based on the difference.

A: 10 μC or less (charge amount change is extremely good)
○: Less than 15 μC (charge amount change is good)
×: 15 μC or more (charge amount change is bad and cannot be used)
《Image evaluation》
Remodeling machine (development, fixing conditions, etc.) of the image forming apparatus “Di-351” (manufactured by Konica Minolta Business Technologies) employing the electrophotographic system for the obtained developers (implementing developers 1 to 3 and comparative developer 1) The following evaluation was carried out using tuning.

Toner scattering
For each developer, adjust the toner density in the developing unit to 8% while taking 2,000 images with a printing rate of 6%, then take 5,000 images with a printing rate of 1%, and finally, a printing rate of 20%. Take 5,000 images. During this time, the toner scattered from the developing device was collected, and its mass was measured, and the rank was evaluated as follows.

A: 30 mg or less (toner scattering is extremely good)
○: Less than 60 mg (good toner scattering)
×: 60 mg or more (toner scattering is bad and cannot be used)
《Fog evaluation》
In a high-temperature and high-humidity environment (temperature: 30 ° C., relative humidity: 80%), print 5K images continuously, turn off the power, leave it for 72 hours, reprint, and observe the formed images sequentially. The number of missing images in the halftone was counted visually, and the rank was evaluated as follows.

A: 0 to 3 ○: 4 to 10 ×: 10 or more

  It can be seen that the toner formed using the latex obtained by quenching and storing the resin dispersion of the present invention has little scattering and shows excellent performance in fog evaluation.

Claims (6)

In a method for producing an associative toner obtained by associating a resin particle dispersion and a colorant particle dispersion, after the resin particle dispersion is formed by an emulsion polymerization method containing an acidic monomer, the temperature of the reaction solution is set to | 30. A method for producing an associative polymerization toner, wherein the toner is cooled at a cooling rate of at least ° C / min |. The method for producing an associative polymerization toner according to claim 1, wherein the cooling start temperature of the reaction liquid is in the range of Tg + 10 ° C to Tg + 70 ° C of the resin. The method for producing an association-type polymerized toner according to claim 1 or 2, wherein the reaction solution has a cooling temperature in the range of 10 to 30 ° C. The method for producing an associative polymerization toner according to claim 1, wherein the reaction liquid is cooled by a heat exchange system. 5. The method for producing an associative polymerization toner according to claim 1, wherein a processing amount of the heat exchange system is 100 to 500 kg / min. An associative polymerized toner formed by the method for producing an associative polymerized toner according to any one of claims 1 to 5.