JP2007101593A - Method for manufacturing electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing electrostatic charge image developing toner suitable for long-term use and continuous printing on a large number of sheets because of stable charging property and low toner consumption. <P>SOLUTION: In the method for manufacturing the electrostatic charge image developing toner by mixing an external additive into toner base particles containing at least a binder resin and a colorant, the mixing is carried out using a mixer having agitating blades under conditions of A×B≥30, wherein A is the maximum rising rate (°C/min) of the internal temperature of the mixer, and B is continuous mixing time (min). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing toner for developing an electrostatic image used for development by an image forming apparatus such as a copying machine or a printer. Specifically, a method for producing a toner for developing an electrostatic charge image that is suitable for long-term use or continuous printing of a large number of sheets because of good flowability, stable charging properties, and low toner consumption. About. More specifically, the present invention relates to a method for producing a toner for developing an electrostatic charge image, which can produce the toner for developing an electrostatic charge image that exhibits the above-mentioned excellent effects with a high yield.

In general, in an electrophotographic system, an electrostatic latent image of an electrostatic charge is formed by various means on a drum-like or film-like photoreceptor containing various photoconductive substances, and the electrostatic latent image is developed with a developer. If necessary, the developer is transferred onto a substrate such as paper or film, and then fixed by a method such as pressurization or heating.
As the developer, a two-component developer composed of a carrier such as iron powder and ferrite powder and a toner, and a one-component developer (nonmagnetic or magnetic toner) that does not require a carrier are known. As the toner at that time, usually various properties such as fluidity and chargeability are imparted to the toner base particles containing a charge control agent, a release agent, a magnetic material, etc., as required, to a binder resin and a colorant. For this purpose, for example, an external additive of solid fine particles such as silica or a charge control agent such as a metal complex or a dye is attached to the surface.

  In recent years, with the widespread use of copying machines, printers, and the like, the demand for image quality has become more and more advanced, and high-quality images are particularly required for high-speed printing or continuous printing. In order to achieve this, it is necessary to improve the fluidity and charging stability of the toner and to lower the softening point of the toner so that it can be fixed at a low temperature. However, the toner with a low softening point has a problem of poor blocking resistance during long-term storage before use. In order to improve the blocking resistance of the toner, it is necessary to sufficiently attach the external additive to the surface of the toner base particle. However, if a large amount of the external additive is added, the external additive will adhere to the surface of the toner base particle. There was a problem that charging did not occur or image defects occurred due to the fact that they did not adhere or the external additives aggregated. As described above, conventionally, in a low softening point toner or the like, it has been difficult to ensure the fluidity and charging stability of the toner by uniformly adhering a large amount of external additive to the surface of the toner base particles.

On the other hand, Patent Document 1 discloses a high-speed stirring type disperser that performs processing such as mixing, dispersion, surface modification, and compounding by stirring powder or granules at high speed. In the method for producing a toner, using a high-speed stirring type disperser of Patent Document 1, resin particles containing a colorant and charge control agent particles are mixed in a container, and the inner wall surface of the mixing container and the periphery of the rotating body are mixed. Proposes speed. However, even if this method is used, the adhesion of the charge control agent and the external additive to the surface of the toner base particles is not sufficient because the maximum heating rate is low and the continuous mixing and stirring cannot be performed. When adding a large amount of additive, it does not solve the problem of external additives that do not adhere to the surface of the toner base particles or the aggregation of the external additives, and also improves productivity. I could not plan.
That is, in the past, it was not clear how a large amount of external additive can be efficiently and uniformly added to the surface of the toner base particles without agglomerating.
Japanese Patent Laid-Open No. 8-173783 JP 2002-351141 A JP 2002-357929 A JP 200398774 A JP 2003-15357 A JP 2003-140391 A JP 2002-268277 A

  The present invention has been made in view of the above-described prior art, and has good fluidity and charging stability, and even when continuously printed, there is little deterioration in development performance and fixing performance, as well as good blocking resistance, and production efficiency. It is an object of the present invention to provide a method for producing a toner for developing an electrostatic image having a high density.

As a result of intensive studies to solve such problems, the present inventors have found that the above problems can be solved by mixing toner base particles with external additives and / or charge control agents under specific conditions. It has come to be completed.
That is, the gist of the present invention is a method for producing a toner for developing an electrostatic image in which an external additive and / or a charge control agent is mixed with toner base particles containing a binder resin and a colorant, and the mixing has a stirring blade. (1) 30 ≦ A × B and (2) 8 where A is a maximum temperature increase rate of the mixing device and A (° C./min) and B (min) is the continuous mixing time. ≦ A ≦ 50 is satisfied, and the toner is mixed under the condition that the internal temperature of the mixing apparatus does not rise above the endothermic maximum point temperature of the toner base particles by DSC.

  Further, the present invention has found that it is preferable to use a mixing device having a specific structure, and has completed the present invention. That is, the internal temperature rise of the mixing device is not due to heat supply from the outside, the internal temperature rise of the mixing device is suppressed, a fixing member protruding on the inner wall of the mixing device is provided, the inner wall of the mixing device The ratio of the surface area of the fixing member protruding to the surface is 0.1 to 20% with respect to 100% of the surface area of the inner wall of the apparatus.

  Furthermore, the present invention has found that it is preferable to employ a specific toner, and has completed the present invention. In other words, the present invention relates to a method for producing a toner for developing an electrostatic charge image, characterized in that the maximum endothermic temperature of the toner base particles by DSC is 55 to 100 ° C.

  A uniform and high-quality image is required when performing a large amount of electrostatic development at high speed, performing electrostatic development continuously for a long period of time, or performing electrostatic development in a high-temperature and high-humidity environment. It is possible to efficiently produce toner for developing an electrostatic charge image that can be used in various printing machines and copying machines.

Hereinafter, the method for producing the toner for developing an electrostatic charge image of the present invention will be described in detail.
The toner for developing an electrostatic charge image in the production method of the present invention contains a binder resin and a colorant, and if necessary, external toner and / or toner base particles containing wax, a charge control agent and other additives. Alternatively, a charge control agent is attached.
As the binder resin used in the present invention, various known resins suitable for toners can be used. For example, styrene resin, polyester resin, epoxy resin, polyurethane resin, vinyl chloride resin, polyethylene, polypropylene, ionomer resin, Examples thereof include silicone resin, rosin-modified maleic resin, phenol resin, ketone resin, ethylene-ethyl acrylate copolymer, polyvinyl butyral resin, and the like, and a mixture thereof may be used. Particularly preferred resins for use in the present invention include styrene resins and polyester resins, with styrene resins being particularly preferred.

  Examples of styrene resins include polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene- Vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-acrylic acid ester-acrylic acid copolymer, styrene-acrylic acid ester-methacrylic acid copolymer, styrene-methacrylic acid copolymer Acid ester copolymer, styrene-methacrylic acid ester-acrylic acid copolymer, styrene-methacrylic acid ester-methacrylic acid copolymer, styrene-α-methyl chloroacrylate copolymer and styrene-acrylonitrile-acrylic acid ester copolymer Styrene such as polymers Or the homopolymer or copolymer containing a styrene derivative is mentioned, A mixture thereof may be sufficient. Among them, styrene-acrylic acid ester-acrylic acid copolymer, styrene-acrylic acid ester-methacrylic acid copolymer, styrene-methacrylic acid ester-acrylic acid copolymer, styrene-methacrylic acid ester-methacrylic acid copolymer. It is more preferable to include a binder resin having an acid group selected from among them because the toner has excellent fixability and durability, and the charge stability (particularly negative chargeability) of the toner is improved. In addition, although the ester group in acrylic acid ester or methacrylic acid ester is not limited, C1-C8 hydrocarbon ester etc., such as methyl ester, ethyl ester, butyl ester, octyl ester, phenyl ester, etc. are mentioned. In addition, some or all of the acrylic acid and methacrylic acid may be substituted with substituted monocarboxylic acids such as α-chloroacrylic acid and α-bromoacrylic acid, fumaric acid, maleic acid, maleic anhydride, monobutyl maleate and the like. Those substituted with saturated dicarboxylic acids, anhydrides thereof or half esters thereof can also be suitably used.

As the polyester-based resin, those obtained by polycondensation with a polyhydric alcohol component and a polycarboxylic acid component as main components are preferable.
Among the polyhydric alcohol components, examples of the dihydric alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1 , 4-Butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol and other diols, bisphenol A, hydrogenated bisphenol A, etherified bisphenols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A, and other alcohol monomers, and those containing bisphenol A are preferred. It is use.

  Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and diphenic acid. , Cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid Examples include acids, n-octyl succinic acid, isooctyl succinic acid, and anhydrides or lower alkyl esters of these acids. Among them, those containing isophthalic acid are preferably used.

Furthermore, the polyester resin can contain a trivalent or higher alcohol component and / or a trivalent or higher carboxylic acid component. Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned. Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, naphthalenetricarboxylic acid, butanetricarboxylic acid, hexanetricarboxylic acid, 1 , 3-dicarboxyl-2-methyl-2-methylenecarboxypropane, cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, octanetetracarboxylic acid, pyromellitic acid, embol dimer acid, and anhydrides of these acids, And lower alkyl esters. These trivalent or higher alcohol components and / or trivalent or higher carboxylic acid components may be contained in an amount of 0.01 to 30 mol%, preferably 0.1 to 5 mol%, based on all monomers constituting the polyester resin. preferable. By including a trivalent or higher alcohol component and / or a trivalent or higher carboxylic acid component, low temperature fixability required for low-energy fixing and durability required for image stability during continuous shooting are both preferable.

Furthermore, monofunctional alcohols and monofunctional carboxylic acids such as benzoic acid, salicylic acid, myristic acid, palmitic acid and stearic acid can also be included. Moreover, it can also have the segment which has chains other than ester bonds, such as a urethane bond and an amide bond, in the structure of a polyester resin.
The softening point (hereinafter referred to as Sp) of the binder resin is preferably 150 ° C. or less, and more preferably 140 ° C. or less for low energy fixing. Further, from the viewpoint of high temperature offset resistance and durability, the Sp is preferably 80 ° C. or higher, and more preferably 100 ° C. or higher. Here, the Sp is a flow tester (CFT-500 manufactured by Shimadzu Corporation), in which 1.0 g of a sample is a nozzle 1 mm × 10 mm, a load of 30 kg, a preheating time of 50 ° C. for 5 minutes, and a heating rate of 3 ° C./minute. Can be obtained as the temperature at the midpoint of the strand from the start to the end of the flow.

Further, the glass transition point (hereinafter referred to as Tg) of the binder resin is usually preferably 80 ° C. or lower, and more preferably 70 ° C. or lower. When the Tg exceeds 80 ° C., the fixing temperature becomes too high, and the deterioration of OHP transparency becomes a problem. Further, the Tg is preferably 40 ° C. or higher, and more preferably 50 ° C. or higher. When the Tg is less than 40 ° C., the storage stability of the toner is deteriorated. Here, the Tg is determined by heating the toner base particle sample from 30 ° C. to 210 ° C. at a heating rate of 10 ° C./min in a differential scanning calorimeter (DSC-2200, manufactured by Seiko Denshi Co., Ltd.). When cooled to 30 ° C. at a rate of 20 ° C./min and heated again at a rate of temperature increase of 10 ° C./min, a tangent is drawn at the beginning of the transition (inflection) of the measured curve, and the intersection of the two tangents It can be calculated as the temperature.

The Tg of the binder resin in the present invention can be adjusted to the above range by adjusting the kind of resin, the monomer composition ratio, the molecular weight, etc., and the one in the above range is appropriately selected from commercially available resins. I can do it.
When the styrene resin is used as the binder resin, the binder resin has at least one of peak molecular weight (Mp) in gel permeation chromatography (hereinafter, GPC) soluble in THF, preferably 3000 or more. It is preferably 10,000 or more, more preferably 30,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and still more preferably 70,000 or less. When the peak molecular weight is less than 3000, the offset property on the high temperature side is deteriorated, and when it exceeds 100,000, the offset property on the low temperature side is deteriorated. When the number average molecular weight, weight average molecular weight, and peak molecular weight of the styrenic resin are in the above ranges, the durability, storage stability, and fixability of the toner are improved. Here, as the value in GPC, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement.

The colorant used in the present invention is not particularly limited, and various inorganic and organic dyes and pigments generally used as a toner colorant are used. Specifically, for example, iron Powder, metal powder such as copper powder, metal oxide such as bengara, inorganic pigment such as carbon represented by carbon black such as furnace black and lamp black, azo type such as benzidine yellow and benzidine orange, quinoline yellow, Acid dyes, basic dyes such as alkali blues, precipitates of rhodamine, magenta, macalite green, etc. dyes such as tannic acid, phosphomolybdic acid, etc. Acid dyes, basic dyes, metal salts of hydroxyanthraquinones Mordant dyes such as phthalocyanine blue, phthalocyanine series such as copper phthalocyanine sulfonate Organic pigments such as quinacridone red and quinacridone violet, organic pigments such as quinacridone and dioxane, aniline black, azo dyes, naphthoquinone dyes, indigo dyes, nigrosine dyes, phthalocyanine dyes, polymethine dyes, di- and triallylmethane dyes, etc. These can be used in combination. Colorants used in full-color toners include yellow azo pigments (insoluble monoazo, insoluble disazo, condensed azo, etc.), polycyclic pigments (isoindoline, isoindolinone, slen, quinophthalone, etc.) Azo pigments (azo lakes, insoluble monoazos, insoluble disazos, condensed azos, etc.), polycyclic pigments (quinacridone pigments, perylene pigments, etc.) and the like for magenta Examples include phthalocyanine pigments and selenium pigments. The combination of the colorants may be appropriately selected in consideration of the hue and the like. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. At least one selected from CI Pigment Yellow 155 is C.I. I. Pigment red 238, C.I. I. Pigment red 269, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 48: 2, C.I. I. At least one selected from CI Pigment Red 122 is C.I. I. Pigment blue 15, C.I. I. At least one selected from CI Pigment Blue 15: 3 is preferable as furnace black carbon as the black colorant. The content of the colorant is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and particularly 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Is good. When two or more colorants are used in combination, the total amount is preferably 1 to 20 parts by weight.

The colorant may have magnetism, and examples of the magnetic colorant include a ferromagnetic material that exhibits ferrimagnetism or ferromagnetism at a temperature around 0 to 60 ° C., which is a use environment temperature of a copying machine or the like. Is, for example, magnetite (Fe ₃ O ₄ ), maghemite (γ-Fe ₂ O ₃ ), an intermediate or mixture of magnetite and maghematite, M _x Fe _{3 -x} O ₄ ; where M is Mg, Spinel ferrite such as Mn, Fe, Co, Ni, Cu, Zn, Cd, hexagonal ferrite such as BaO.6Fe ₂ O ₃ , SrO.6Fe ₂ O ₃ , Y ₃ Fe ₅ O ₁₂ , Sm ₃ Fe ₅ O Garnet type oxide such as ₁₂ , rutile type oxide such as CrO ₂ , and Cr, Mn, Fe,
Among metals such as Co and Ni or their ferromagnetic alloys, those showing ferromagnetism and ferrimagnetism in the vicinity of 0 to 60 ° C. can be mentioned, and they can be used alone or in combination of two or more. Among these, magnetite, maghematite, or an intermediate between magnetite and maghematite is preferable. When the toner is added from the viewpoint of preventing scattering and charging control while maintaining the characteristics as a non-magnetic toner, the addition amount is 0.5 to 10 parts by weight, preferably 0. 5 to 8 parts by weight, more preferably 1 to 5 parts by weight. Further, when used as a magnetic toner, the addition amount is preferably 20 parts by weight or more and 150 parts by weight or less with respect to 100 parts by weight of the binder resin.

The toner for developing an electrostatic image in the present invention may contain a wax. By containing a wax, the low temperature fixing property, the high temperature offset property, the filming resistance and the like may be improved, which is preferable. The wax is not limited as long as it is usually used for toner applications, and specifically, olefin wax such as low molecular weight polyethylene, low molecular weight polypropylene, copolymer polyethylene, paraffin wax, silicone wax having an alkyl group; A higher fatty acid such as stearic acid; a long-chain aliphatic alcohol such as eicosanol; an ester wax having a long-chain aliphatic group such as behenyl behenate, a montanic acid ester, and stearyl stearate; a long-chain alkyl group such as distearyl ketone; Ketones, plant waxes such as hydrogenated castor oil carnauba wax; esters or partial esters obtained from polyhydric alcohols such as glycerin and pentaerythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide Low Molecular weight polyesters, and the like. The wax suitable for the present invention can be suitably used by selecting from olefin wax such as ester wax, paraffin wax, low molecular weight polypropylene and copolymer polyethylene, and silicone wax having an alkyl group. The wax preferably has at least one endothermic peak due to DSC at 50 to 100 ° C. When the wax is contained, the content thereof is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, still more preferably 1 part by weight or more, and 20 parts by weight or less with respect to 100 parts by weight of the toner. It is preferable that the amount is 15 parts by weight or less. The dispersed particle diameter of the wax in the toner for developing an electrostatic charge image in the present invention is preferably 0.1 μm or more, more preferably 0.3 μm or more, preferably 3 μm or less, more preferably 1 μm or less as an average particle diameter. is there. If the average particle size is less than 0.1 μm, the effect of improving the releasability of the toner may not be sufficient, and if it exceeds 3 μm, it may be easily exposed on the surface of the toner and the chargeability and heat resistance may be reduced. . The dispersed particle diameter of the wax is not only a method of observing an electron microscope after thinning the toner, but also a method of measuring the particle diameter of the wax in the solution by dissolving the binder resin of the toner with an organic solvent or the like in which the wax does not dissolve. Can be confirmed.

  The toner for developing an electrostatic image in the present invention may contain a charge control agent for imparting charge amount and charge stability. As the charge control agent, conventionally known compounds are used. For example, as the positive charge control agent, nigrosine dye, quaternary ammonium salt, triaminotriphenylmethane compound, imidazole compound, polyamine resin, etc. Examples of the negatively chargeable charge control agent include azo complex compound dyes, alkyl salicylic acid complex compounds and curixarene compounds containing atoms such as Cr, Co, Al, Fe, and B. For full-color toners, it is necessary to select a color tone of the charge control agent that is colorless or light in order to avoid a color tone failure as a toner. A quaternary ammonium salt and an imidazole compound are preferable, and the negatively chargeable charge control agent is an alkyl salicylic acid complex compound or a curixarene compound containing atoms such as Cr, Co, Al, Fe, and B. preferable. Moreover, these mixtures may be sufficient. The addition amount of the charge control agent is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

Further, in the present invention, the toner contains various known internal additives such as silicone oil and silicone varnish for the purpose of modifying the adhesiveness, cohesiveness, fluidity, chargeability, surface resistance, etc. of the toner. You can also
Hereinafter, the method for producing the toner for developing an electrostatic charge image of the present invention will be described in detail.
In the method for producing an electrostatic charge image developing toner of the present invention, the method for producing toner mother particles is not limited, and dry methods such as pulverization methods, polymerization methods (suspension polymerization method and emulsion polymerization aggregation method) and solvent precipitation methods. Any manufacturing method such as a wet method can be used. Among these, it is preferable to manufacture by a wet method from the viewpoint of controllability of the particle size distribution and circularity of the obtained toner, more preferably by a polymerization method, and particularly preferably by an emulsion polymerization aggregation method.

When the toner base particles are produced by a pulverization method, it can be performed according to a conventionally known method. That is, usually, first, a binder resin, a colorant, and other components such as a charge control agent and wax added as needed are uniformly dispersed and mixed in a mixer, and then the mixture is Banbury mixer, CM mixer, sealed Melt and knead with a kneader or a single-screw or twin-screw extruder, etc., cool, crush with a crusher, hammer mill, etc., finely pulverize with a jet mill, high-speed rotor rotary mill, etc., and an air classifier (for example, inertia It can be obtained by a classifying method using a classifying elbow jet, a centrifugal classifying microplex, a DS separator, or the like.

  When the toner base particles are produced by a suspension polymerization method, it can be carried out according to a conventionally known method. That is, usually, a polymerizable monomer, a suspension polymerization dispersant, a polymerization initiator, a colorant, and other components such as a charge control agent and a wax that are added as necessary are included in the aqueous medium. After suspending and dispersing to an appropriate particle size using a disperser such as a disperser, the polymerizable monomer is polymerized to obtain toner base particles. The polymerization temperature is preferably from 30 to 200 ° C, more preferably from 60 to 100 ° C. The pressure during polymerization may be any of under pressure, normal pressure, and reduced pressure. The polymerization time is preferably 1 to 15 hours, and more preferably 3 to 10 hours. As the binder resin constituting the toner base particles by the suspension polymerization method, the above-mentioned resin is used, but as the polymerizable monomer as a raw material, the same one as the polymerizable monomer used in the emulsion polymerization aggregation method described later is used. can do.

  When the toner base particles are produced by a solvent precipitation method (chemical pulverization method), it can be carried out according to a conventionally known method. That is, normally, a binder resin and a colorant and, if necessary, a charge control agent, a release agent, and a magnetic substance are dissolved or dispersed in a solvent in which the binder resin is dissolved, and this solution has low solubility in the binder resin. By mixing with a liquid, the particles are precipitated to obtain toner mother particles.

Next, the case of the emulsion polymerization aggregation method that is particularly preferable for producing the toner base particles in the present invention will be described in detail. In the present invention, the emulsion polymerization aggregation method means a production method having a step of aggregating an emulsion containing at least polymer primary particles obtained by the emulsion polymerization method.
In the case of producing toner base particles by the emulsion polymerization aggregation method, usually, an emulsion polymerization step, a mixing step, an aggregation step, and an aging step are included. That is, generally, a colorant, if necessary, a charge control agent, a wax or the like is mixed in an emulsion containing polymer primary particles as a binder resin obtained by emulsion polymerization, and primary particles in this emulsification are mixed. Is agglomerated and aged to form particle aggregates, and the obtained toner base particles are washed and dried.

The polymerizable monomer constituting the polymer primary particle is not limited, and examples thereof include styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, and pn-nonylstyrene. Styrenes, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylic acid n- (Meth) acrylic acid esters such as butyl, isobutyl methacrylate, hydroxyethyl methacrylate, ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylate Ruamido, N, N-dibutyl acrylamide, acrylic acid amide, and the like. Among these styrene, butyl acrylate are particularly preferred. These monomers may be used alone or in combination. In addition, the polymerizable monomer constituting the polymer primary particles may be a monomer having a Bronsted acidic group (hereinafter sometimes simply referred to as an acidic monomer) and / or a Bronsted base together with or in place of the monomer. It is also preferable to use a monomer having a functional group (hereinafter sometimes simply referred to as a basic monomer) as a raw material monomer. Examples of acidic monomers include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, monomers having a sulfonic acid group such as sulfonated styrene, and sulfonamide groups such as vinylbenzenesulfonamide. And the like. Examples of basic monomers include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocycle-containing monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate,
Examples thereof include (meth) acrylic acid esters having an amino group such as diethylaminoethyl methacrylate. These acidic monomers and basic monomers may be used alone or in combination, and may exist as a salt with a counter ion. When an acidic monomer or a basic monomer is used as the monomer constituting the polymer primary particles, the total amount of the acidic monomer or the basic monomer is preferably 0.00 with respect to 100 parts by weight of the total monomers constituting the polymer primary particles. It is desirable that the amount is not less than 05 parts by weight, more preferably not less than 0.5 parts by weight, still more preferably not less than 1 part by weight, preferably not more than 10 parts by weight, more preferably not more than 5 parts by weight. Thus, by using an acidic monomer or a basic monomer, the dispersion stability of the polymer primary particles may be improved.

  Furthermore, a polyfunctional monomer can also be used as a monomer constituting the polymer primary particles. Examples of the multifunctional monomer include divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, diallyl phthalate, and the like. It is also possible to use monomers having a reactive group in the pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radical polymerizable bifunctional monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional monomers may be used alone or in combination.

  When a polyfunctional monomer is used as the monomer constituting the polymer primary particles, the content thereof is preferably 0.005 parts by weight or more, more preferably 100 parts by weight or more based on the total monomers constituting the polymer primary particles. It is desirable that it is 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and still more preferably 1 part by weight or less. By using a polyfunctional monomer in this way, the fixability may be improved.

  Examples of the polymerization initiator include persulfates such as sodium persulfate and ammonium persulfate, organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, and p-menthane hydroperoxide, hydrogen peroxide, and the like. One or two or more inorganic peroxides are usually used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the polymerizable monomer. Of these, inorganic peroxides are preferred as the polymerization initiator. In addition, these polymerization initiators include one or more reducing agents such as reducing organic compounds such as ascorbic acid, tartaric acid and citric acid, and reducing inorganic compounds such as sodium thiosulfate, sodium bisulfite and sodium metabisulfite. It can also be set as the redox type | system | group initiator which used 2 or more types together.

Further, a known chain transfer agent can be used as necessary, and specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is usually used in the range of 5% by weight or less based on the total monomers.
As the emulsifier, nonionic, anionic, cationic and amphoteric surfactants are usually used. Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether, and sorbitan fatty acid esters such as sorbitan monolaurate. Examples of the anionic surfactant include fatty acid salts such as sodium stearate and sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, and alkyl sulfate salts such as sodium lauryl sulfate. Examples of the cationic surfactant include alkylamines such as laurylamine acetate, and 4 such as lauryltrimethylammonium chloride.
Examples of amphoteric surfactants such as quaternary ammonium salts include alkylbetaines such as laurylbetaine, and one or more of these are used. Of these, nonionic surfactants and anionic surfactants are preferred. The amount used as an emulsifier is usually 1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer, and these emulsifiers include, for example, partially or fully saponified polyvinyl alcohols such as saponified polyvinyl alcohol, hydroxyethyl cellulose. 1 type, or 2 or more types, such as cellulose derivatives, etc. can be used together as a protective colloid.

  In addition, the addition of the polymerizable monomer to the reaction system in the emulsion polymerization may be any of batch addition, continuous addition, and intermittent addition, but from the viewpoint of reaction control, continuous addition is preferable. Moreover, when using a some monomer, the addition of each monomer may be added separately, or a plurality of monomers may be mixed and added simultaneously. Furthermore, it is possible to change the monomer composition during the monomer addition. The addition of the emulsifier to the reaction system may be any of batch addition, continuous addition, and intermittent addition. In addition to the emulsifier and the polymerization initiator, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

The polymer primary particles in the present invention can be used in combination with a plurality of different polymer primary particles obtained as described above.
The polymer primary particles in the present invention can be used in combination with particles obtained by the above emulsion polymerization, particles obtained by other polymerization methods, or two or more kinds in combination.

  The volume average particle size of the polymer primary particles in the present invention is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, usually 3 μm or less, preferably 2 μm or less, more preferably 1 μm. The following is desirable. The volume average particle diameter can be measured using, for example, Nikkiso Microtrac UPA. If the volume average particle size is less than 0.02 μm, it may be difficult to control the aggregation rate. If the volume average particle size exceeds 3 μm, the particle size of the toner obtained by aggregation tends to be large. It may be difficult to obtain.

When the toner of the present invention contains a wax, the wax can be added in an agglomeration step, which will be described later. However, the wax-containing polymerization is performed by using seed polymerization as a seed in emulsion polymerization of the polymerizable monomer. Primary particles can also be produced.
In the production of toner particles by the emulsion polymerization aggregation method, a colorant and, if necessary, additives such as a charge control agent, a wax, and other components are added to the emulsion of the polymer primary particles obtained by the emulsion polymerization. Then, while stirring and mixing with a disperser, a mixer, etc., for example, heating, electrolyte addition, pH adjustment, curing agent addition, etc. Aggregation is performed to form an aggregate, and then primary particles in the aggregate are aged (fused) and stabilized by heat treatment.

As an electrolyte in the case of performing aggregation by adding an electrolyte, either an organic salt or an inorganic salt may be used. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , _{MgCl 2, CaCl 2, MgSO 4} , CaSO 4, ZnSO 4, Al 2 (SO 4) 3, Fe 2 (SO 4) 3, CH 3 COONa, C 6 H 5 SO 3 Na and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred. The amount of electrolyte added varies depending on the type of electrolyte, but is usually 0.05 parts by weight or more, preferably 0.1 parts by weight or more, and usually 25 parts by weight or less with respect to 100 parts by weight of the solid component of the mixed dispersion. The amount is preferably 15 parts by weight or more preferably 10 parts by weight or less. When aggregation is performed by adding an electrolyte, if the amount of electrolyte added is less than 0.05 parts by weight, the progress of the agglomeration reaction is delayed, and a fine powder of 1 μm or less remains after the agglomeration reaction, or the obtained particle agglomeration. The average particle size of the aggregate may not reach the target particle size, and if it exceeds 25 parts by weight, rapid aggregation tends to occur, making it difficult to control the particle size. Problems such as inclusion of powder or irregular shapes may occur. In addition, 20-40 degreeC is preferable and the aggregation temperature in the case of performing an aggregation by adding electrolyte has more preferable 25-35 degreeC.

  The heating temperature at the time of fusing and stabilizing the primary particles in the aggregate (ripening) is preferably not less than the glass transition temperature of the polymer constituting the primary particles, more preferably not less than 5 ° C. higher than the glass transition temperature. . Moreover, the temperature below 80 degreeC higher than the glass transition temperature of a polymer is preferable, and the temperature below 50 degreeC is still more preferable. The heating time is preferably 1 to 6 hours. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused together. In addition, the shape of the toner particles can be made nearly spherical. According to such a ripening step, by controlling the temperature and time of the ripening step, a cocoon shape in which primary particles are aggregated, a potato type in which fusion has progressed, a spherical shape in which fusion has further progressed, etc. Various shapes of toner can be produced according to the purpose.

  The toner base particles thus obtained can then undergo a washing and drying process. The liquid used for washing can be performed only by replacing the water in which the toner is immersed in the final step of the emulsion polymerization aggregation method with water of higher purity. It can also be washed. The washing can be performed not only at room temperature but also by heating, and a combination of these methods can also be used. By passing through such a washing step, an emulsifier, a solvent, an unreacted residual monomer and the like can be reduced and removed, which is preferable.

  The toner for developing an electrostatic charge image according to the present invention further comprises a polymer as a main component on the surface of the obtained particles by a method such as a spray drying method, an in-situ method, or a submerged particle coating method. By forming the outer layer preferably with a thickness of 0.01 to 0.5 μm, encapsulated toner base particles can be obtained. The Tg of the outer layer polymer in the encapsulated toner particles is preferably 70 to 110 ° C., and preferably higher than the Tg of the polymer constituting the aggregated (aged) particles.

The volume average particle size of the toner base particles in the present invention is preferably in the range of 3 to 12 μm, more preferably 5 to 10 μm. Here, the volume average particle diameter can be measured using a multisizer (manufactured by Coulter).
The shape of the toner base particles is such that the 50% circularity measured using a flow type particle image analyzer FPIA-2000 is preferably 0.90 or more, more preferably 0.92 or more, still more preferably 0.94 or more. is there. When the 50% circularity is less than 0.90, the image density may be lowered due to deterioration of charging due to adhesion failure of an external additive described later. The 50% circularity is desirably 0.98 or less. If the 50% circularity exceeds 0.98, a cleaning failure may occur. As a method for obtaining toner mother particles having a 50% circularity in the above range, an emulsion polymerization aggregation method can be preferably used.

The Sp of the toner base particles is preferably 150 ° C. or less, and more preferably 140 ° C. or less for low energy fixing. Further, from the viewpoint of high temperature offset resistance and durability, the Sp is preferably 80 ° C. or higher, and more preferably 100 ° C. or higher.
Further, the endothermic maximum point temperature of the toner base particles by the DSC method is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower. When the endothermic maximum point temperature is less than the above range, the storage stability of the toner deteriorates. When the endothermic temperature exceeds the above range, the fixing temperature becomes too high or the OHP transparency deteriorates. The maximum endothermic temperature of the toner base particles by the DSC method is determined by using a differential scanning calorimeter (DSC-2200, manufactured by Seiko Denshi Co., Ltd.).
After heating to 210 ° C at a rate of ° C / min, cooling to 30 ° C at a rate of temperature drop of 20 ° C / min, and again from the maximum absorption peak when heating at a rate of temperature increase of 10 ° C / min I can do it.

The method for producing a toner for developing an electrostatic image according to the present invention is characterized by a method in which toner base particles and an external additive and / or a charge control agent are externally added by mixing.
That is, according to the present invention, at least the toner base particles and the external additive and / or the charge control agent are mixed by a mixing device having a stirring blade, and the maximum temperature increase rate of the mixing device is A (° C./min). When the continuous mixing time is B (minutes), the A × B value is 30 or more, preferably 50 or more, more preferably 80 or more. Mixing under a condition where the value of A × B is 30 or more improves the fluidity and charging stability of the resulting electrostatic image developing toner, so that the image characteristics are improved and the toner consumption is suppressed. The If mixing is performed so that the value of A × B falls within the above range, mixing can be performed strongly and efficiently, so that the effect of crushing the agglomerated external additive is increased and the toner base particles are mixed inside the mixer. The external additive is uniformly dispersed. Therefore, it is considered that the crushed external additive and / or charge control agent can be uniformly attached to the surface of the toner base particles. The upper limit of the value of A × B is not limited, but it is usually 200 or less, preferably 160 or less, more preferably 130 or less. When the value of A × B exceeds the above range, the toner base particles are softened and deformed, or the external additive and / or the charge control agent attached to the toner base particle surface may be embedded in the base particles. In addition, the toner may be fused to the inner wall of the mixing device.

Here, the maximum rising speed A of the mixing device internal temperature is set to the following value. First, the internal temperature of the mixing apparatus is measured every 15 seconds from the start of mixing. Calculate how many degrees C the internal temperature rose every 15 seconds based on the measurement result. The value with the largest increase (° C.) is divided by time to obtain the maximum increase rate A (° C./min).
In the production method of the present invention, the lower limit of the maximum rising speed A of the mixing apparatus internal temperature is 9 ° C./min or more, preferably 10 ° C./min or more, more preferably 15 ° C./min or more, and further preferably 18 ° C./min. The above is desirable. When the maximum rising speed A of the internal temperature of the mixing apparatus is less than the above range, the chargeability of the obtained toner for developing an electrostatic image is unstable, the mixing process takes a long time, and the energy efficiency is poor. On the other hand, the upper limit of the maximum rising speed A of the mixing device internal temperature is 60 ° C./min or less, preferably 50 ° C./min or less, more preferably 40 ° C. or less, and further preferably 35 or less. When the maximum temperature increase rate A of the mixing device exceeds the above range, the control of the manufacturing conditions tends to be difficult due to the rapid temperature increase, and the adhesion of the external additive to the toner base particles becomes uneven, and the toner In some cases, the chargeability of the battery deteriorates.

In the production method of the present invention, the continuous mixing time B (minute) is preferably 3 minutes or longer, more preferably 4 minutes or longer, and further preferably 5 minutes or longer. When the continuous mixing time is less than the above range, the external additive and / or the charge control agent is not sufficiently fixed to the surface of the toner base particles, and the chargeability of the resulting electrostatic image developing toner tends to be unstable. .
The upper limit of the continuous mixing time (B) is not limited, but is usually 40 minutes or less, more preferably 30 minutes or less, and still more preferably 20 minutes or less. If the continuous mixing time (B) exceeds the above range, the toner base particles may be softened and deformed, or the external additive and / or the charge control agent attached to the surface of the toner base particles may be embedded in the base particles. In addition, the toner may be fused to the inner wall of the mixing device. By setting the continuous mixing time within the above range, the total external addition time can be shortened and an appropriate external addition state can be formed.

At this time, when the continuous mixing time is within the above range, care must be taken so that the temperature in the mixer rises and toners do not agglomerate and fuse the toner to the inner wall of the mixer. However, for example, when the control is performed by lowering the temperature inside the mixer by inserting a process of stopping the apparatus, such as a process of repeatedly performing a cycle of stopping for 1 minute after stirring for 2 minutes, the external addition process requires a long time. It is not preferable because the deterioration of the toner base particles is promoted by repeated cooling and heating, and because the continuous stirring time is short, the fixing strength of the external additive and / or the charge control agent is weak.

  In the present invention, the upper limit of the internal temperature of the mixing device is not more than the maximum endothermic temperature of the toner base particles by the DSC method, preferably not more than 7 ° C. below the endothermic maximum point temperature of the toner base particles by the DSC method, more preferably The temperature is 12 ° C. or lower than the endothermic maximum point temperature of the toner base particles by the DSC method. When the internal temperature of the mixing device exceeds the endothermic maximum point temperature of the toner base particles by the DSC method, the toner base particles soften and deform, or the external additive and / or charge control adhered to the toner base particle surface In some cases, the agent may be embedded in the mother particles, and the toner, the external additive, and / or the charge control agent may be fused to the inner wall of the mixing device. In order to adjust the temperature in this way, it can be achieved depending on the stirring conditions, the shape of the stirring blade, etc., but it is preferably achieved by releasing heat (cooling) by heat exchange, such as cooling the inside of the mixing device with a refrigerant. I can do it.

  Here, the increase in the internal temperature of the mixing device is not substantially due to heat supply from outside the mixing chamber, but is caused by mechanical action, that is, rotation of the stirring blade provided in the mixing device. The toner obtained by the additive and / or the charge control agent and the external addition is stirred at high speed, and is based on heat generated by friction or collision between these particles or between the particles and the mixing device member (wall surface, stirring blade, etc.). Means temperature rise.

  In the present invention, it is not excluded to supply heat from outside the mixing chamber or to release (cool) heat from the mixing chamber. Even in such a case, if stirring and mixing are performed under the same conditions except that the heat supply or the heat release is not performed, the process may include a step in which the internal temperature of the mixing device rises as described above. Since the operation is the same, it is included in the present invention.

However, as described above, since the production method of the present invention can give sufficient stirring (mixing) power to the particles to be mixed, it is desirable not to supply heat from outside the mixing chamber. However, for example, when the temperature of the raw material or the apparatus before stirring is low (for example, 20 ° C. or lower) and the temperature of the raw material is adjusted in advance, heat supply may be performed.
On the other hand, it is desirable to use heat release (cooling) as necessary when the internal temperature of the mixing device rises excessively during mixing. For example, a method of cooling from the inside or the outside of the mixing apparatus can be mentioned. Specifically, there are a method of controlling the temperature by passing water through an installed jacket, a method of applying cold air, a cooling method using a Peltier element, a cooling method using a vortex tube, and the like.

  In the present invention, the measurement of the internal temperature of the mixing apparatus is not limited as long as the temperature of the particles during mixing can be substantially measured, but usually the temperature protruding from the inner wall of the mixing apparatus to the mixing chamber. It is measured by a sensor or a temperature sensor attached to a stirring blade. Usually, it is desirable to install the temperature sensor at a position where it is buried in the stationary particles when the stirring blade does not rotate. During the rotation of the stirring blade, the temperature sensor comes into contact with the particles being stirred and the gas in the apparatus, and this temperature is set as the internal temperature. Moreover, as long as the value obtained by the temperature sensor is a means that can be obtained, the measurement is performed by another method, for example, a sensor installed at a position not buried in the particles left stationary when the stirring blade does not rotate. Alternatively, it may be measured by a sensor installed inside the mixing device member without protruding into the mixing chamber, or by a non-contact temperature sensor.

In the present invention, means for including the step of increasing the internal temperature of the mixing apparatus as described above is not limited, but mixing conditions such as the shape of the mixing apparatus, the shape of the stirring blade, the rotation speed of the stirring blade and the stirring time, etc. This can be achieved by optimizing the amount of particles to be introduced, etc. Among these, optimizing the shape of the mixing device is most effective for increasing the internal temperature of the mixing device as described above.

If the mixing apparatus used for this invention has a stirring blade, the shape will not be limited, A substantially vertical cylindrical shape, a substantially spherical shape, a double cone type etc. will be illustrated. Among these, a substantially vertical cylindrical shape or a substantially spherical shape is desirable, and a substantially spherical shape is particularly desirable. The inner wall of the apparatus is preferably a smooth surface with a small surface roughness.
The mixing device is preferably provided with a fixing member protruding from the inner wall of the device. By providing the fixing member protruding on the inner wall of the apparatus, the number of collisions between the particles stirred at high speed by the rotation of the stirring blades or between the particles and the mixing apparatus member is increased, so that the internal temperature of the mixing apparatus rises as described above. This is desirable because it becomes easier.

Here, the substantially spherical shape is not limited to a true spherical shape, and may be any shape close to a spherical shape. For example, when the bottom surface or the top surface is partially flat, Thus, it includes a shape in which surfaces having different curvatures are continuous. Among these, those close to a true sphere are preferable except for the stirring blade portion and the raw material inlet. In this way, by making the mixing chamber of the mixing device substantially spherical, the toner base particles and the external additive released in the centrifugal direction by the rotation of the stirring blade rise along the inner wall of the device and near the top of the tank or Since it reaches the fixing member protruding to the inner wall of the apparatus, the particles collide with each other efficiently, so that the particles that are not stirred can be prevented from staying and the inner wall surface of the mixing chamber can be self-cleaned with the particles.
Hereinafter, a substantially spherical mixing device that is preferably used in the method for producing a toner for developing an electrostatic charge image of the present invention will be described with reference to FIG. 1, but the embodiment of the present invention is limited to that shown in FIG. It is not something.

  The mixing chamber 1 has a substantially spherical shape and is a space formed by the jacket 2. The jacket 2 may have a structure that can be divided into a plurality of parts, for example, a structure that can be divided vertically. The structure in which the jacket 2 can be divided in this way facilitates the cleaning operation when the brand of the product toner is switched. In the case of a structure that can be divided, a flange 3 is usually provided at the connecting portion of the jacket 2.

Moreover, the jacket 2 can heat or cool the particles to be mixed by having a heat source or a heat medium capable of exchanging heat therein. Among them, the jacket 2 is preferably designed so that a heat medium can flow, and may further include two or more systems such as a heating system and a cooling system.
The mixing chamber 1 is usually provided with an inlet 4 for introducing toner base particles, external additives, and other raw materials added as necessary. The position where the inlet 4 is provided is not limited as long as each raw material to be mixed can be supplied to the mixing chamber 1, but is usually provided at the upper portion of the mixing chamber 1. The inlet 4 is preferably provided with an openable / closable shielding plate so that the inner wall of the mixing chamber 1 becomes a continuous curved surface during mixing. The shielding plate is large between the inner wall of the mixing chamber 1. It is desirable to be provided so as not to cause a step.

  The mixing chamber 1 is usually provided with a discharge port 5 for discharging the toner obtained by mixing. The position of the discharge port 5 is not limited as long as the toner can be discharged from the mixing chamber 1, but is usually provided at the lower part or the lower side surface of the mixing chamber 1. The discharge port 5 is preferably provided with an openable / closable shielding plate so that the raw materials are not discharged before the mixing is completed, and the shielding plate has a large step between the inner wall of the mixing chamber 1. It is desirable to be provided so as not to occur. Further, it is desirable that the toner is discharged by rotating the stirring blade 6 at a low speed.

A temperature sensor 7 is provided from the jacket 2 so as to protrude into the mixing chamber 1. The temperature sensor 7 is usually installed at a position where the temperature is buried in the particles when the stirring blades 6 do not rotate and the particles stand still. Apart from this, in the state where the stirring blade 6 does not rotate and the particles are allowed to stand still, they can be separately provided at a position where they do not contact the particles.
The mixing chamber 1 may be pressure-sealed so that the inside can be depressurized or pressurized. When the inside of the mixing chamber 1 is used after being depressurized or pressurized, the mixing chamber 1 is designed so as to be connectable to a depressurizing device or a pressurizing device. Is provided.

  A drive shaft 8 perpendicular to the center of the mixing chamber 1 is normally passed through the bottom of the mixing chamber 1 and can be rotated by external power. The drive shaft 8 is provided with a stirring blade 6. The shape of the stirring blade 6 is not limited as long as it can discharge particles upward along the inner wall of the mixing chamber 1 by its rotation, and the shape of the stirring blade 6 can be optimized depending on the scale of the apparatus, the kind of particles to be mixed, and the like. it can. What is necessary is just to adjust the number of the stirring blades 6 by about 2-10 sheets according to the scale and shape of an apparatus.

  Moreover, the boss | hub 9 of substantially cone shape etc. is arrange | positioned and it may have the stirring blade 6 on the surface. The shape of the boss 9 is not limited to a substantially conical shape, but may be a pyramid shape, a shape in which the gradient of the cone is gentle at the skirt portion, a shape in which a groove is carved in the cone, or the like. The shape of the stirring blade 6 provided on the surface of the boss 9 is not limited as long as it can discharge particles upward along the inner wall of the mixing chamber 1 by its rotation, and the scale of the apparatus, the kind of particles to be mixed, etc. Can be optimized and used. Especially, the case where the stirring blade 6 is provided in the lower end outer peripheral part of the boss | hub 9, and it has a shape along the spherical inner wall of the mixing chamber 1 is preferable. Further, it is also preferable that the auxiliary blade 10 is provided on the upper portion of the boss 9 together with the stirring blade 6. The auxiliary blade 10 may be not only one stage but also multistage. The number of the stirring blades 6 and the auxiliary blades 10 that can be provided as necessary may be adjusted to about 2 to 10 in accordance with the scale and shape of the apparatus. Thus, by using the substantially conical boss 9 and providing the stirring blade 6 on the surface, it becomes easy to increase the rotational speed and rotational torque, and the particles can be efficiently stirred. On the other hand, a large physical load can be applied and the amount of processing can be increased.

The shape of the bottom of the mixing chamber 1 may be different from a substantially spherical shape in accordance with the shape of the stirring blade 6 or the shape of the boss 9 and may be a flat surface. Further, when the boss 9 is used, it is preferable that the gap between the boss 9 and the wall surface (bottom part) of the mixing chamber 1 in contact with the boss 9 is designed to be small so that particles do not enter the gap. It is also preferable to design.
Furthermore, it is preferable that a fixing member 11 protruding from the inner wall is provided on the inner wall of the mixing chamber 1. When the fixing member 11 is not provided, the particles released to the upper part of the mixing chamber 1 by the rotation of the stirring blade 6 collide with each other while reducing the moving speed, and then the lower part of the mixing chamber 1. It will be repeated to fall. On the other hand, when the fixing member 11 is provided, the particles collide with the fixing member 11 at a high speed. As a result, the chance of collision between the toner base particles and the external additive is increased, and aggregation of the external additives can be crushed.

Although the fixing position, shape, and size of the fixing member 11 are not limited, it is desirable to design the fixing member 11 so as not to impair the overall circulation of the particles in the mixing chamber 1 and to prevent the staying of unstirred particles. For this reason, the position of the fixing member 11 is preferably installed above the center of the height of the mixing chamber 1. As shown in FIG. 1, even when the fixing member 11 is installed vertically on the inner wall of the mixing chamber 1, the particles being mixed are blown up to the inner wall of the mixing chamber 1 by the rotating action of the stirring blade 6. , It will collide with the fixing member 11. As for the position of the fixing member 11, in addition to the case where it is attached to the inner wall of the mixing chamber 1 as shown in FIG. 1, the wall surface of the charging port 4 protrudes into the mixing chamber 1 as shown in FIG. It can also be installed on the protrusion.
Further, a shape in which a staying portion is difficult to occur is desirable.
In addition, the size of the fixing member may be any size as long as it can enter the mixing chamber, but if it is too large, a stagnant portion is generated. .

As the mixing device used in the method for producing a toner for developing an electrostatic charge image of the present invention, a device provided with a fixing member on the inner wall of a Q mixer manufactured by Mitsui Mining Co., Ltd., which is a substantially spherical mixing device, can be suitably used.
In the present invention, the amount of particles to be charged into the mixing device is not limited, but the total bulk volume of particles to be charged with respect to the internal volume of the mixing device is preferably 5% by volume or more, more preferably 10% by volume or more, and still more preferably. It is 15 volume% or more, Preferably it is 60 volume% or less, More preferably, it is 50 volume% or less, More preferably, it is 40 volume% or less. When the bulk volume of the particles with respect to the internal volume of the mixing apparatus is less than 5% by volume, the stirring efficiency is poor, and collision between the particles hardly occurs, so the internal temperature rise of the mixing apparatus tends to be insufficient, and 60% by volume In the case of exceeding the range, there is a tendency for poor dispersion due to too many particles.

In the present invention, the rotational peripheral speed of the stirring blade is not limited, and is preferably optimized as appropriate depending on the scale of the apparatus. The rotational peripheral speed of the stirring blade means the maximum speed as the rotation locus of the stirring blade.
The solid fine particles as an external additive used in the present invention can be appropriately selected from various inorganic or organic fine particles.

  Inorganic fine particles include silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, and other carbides, boron nitride, titanium nitride. Various nitrides such as zirconium nitride and silicon nitride, various borides such as zirconium boride, titanium oxide, calcium oxide, magnesium oxide, zinc oxide, zirconium oxide, copper oxide, aluminum oxide, cerium oxide, silica, colloidal silica, etc. Various oxides, various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate, barium titanate, phosphate compounds such as calcium phosphate, sulfides such as molybdenum disulfide, magnesium fluoride, carbon fluoride, etc. Various metal soaps such as fluoride, aluminum stearate, calcium stearate, zinc stearate, magnesium stearate, talc, hydrotalcite, talc, bentonite, various carbon blacks, conductive carbon black, magnetite, ferrite etc. it can. As the organic fine particles, fine particles such as styrene resin, acrylic resin, epoxy resin, and melamine resin can be used. Further, the solid fine particles are obtained by applying the surface of the inorganic or organic fine particles to a silane coupling agent, a titanate coupling agent, a silicone oil, a modified silicone oil, a silicone varnish, a fluorine silane coupling agent, a fluorine silicone oil, an amino acid. What has been subjected to surface treatment such as hydrophobization by a treating agent such as a coupling agent having a group or a quaternary ammonium base can be used, and two or more kinds of the treating agents can be used in combination.

  Among these solid fine particles, silica, titanium oxide, alumina, zinc oxide, various carbon blacks and conductive carbon blacks are particularly preferably used. Further, the externally added fine particles are obtained by applying the surface of the inorganic or organic fine particles to a silane coupling agent, a titanate coupling agent, a silicone oil, a modified silicone oil, a silicone varnish, a fluorine silane coupling agent, a fluorine silicone oil, What has been subjected to surface treatment such as hydrophobization with a treating agent such as a coupling agent having an amino group or a quaternary ammonium base can also be used. Two or more kinds of the treatment agents can be used in combination.

The external additive has a number average particle size of usually 0.001 to 3 μm, preferably 0.005 to 1 μm.
m, and a plurality of particles having different particle diameters can be blended. The average particle diameter of the solid fine particles can be determined by electron microscope observation, conversion from the value of the BET specific surface area, or the like.
In addition, the above-mentioned solid fine particles can be used in combination of two or more different types, and can be used in combination with those which have been surface-treated and those which have not been surface-treated, or those which have been subjected to different surface treatments. In addition, a positively chargeable one and a negatively chargeable one can be used in appropriate combination.

  The addition amount of the external additive is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, still more preferably 0.5 parts by weight or more, based on 100 parts by weight of the toner base particles. Is 6 parts by weight or less, more preferably 5 parts by weight or less, and still more preferably 4 parts by weight or less. When the addition amount is less than 0.01 parts by weight, when used as an electrostatic charge image developing toner, fluidity may be deteriorated and toner consumption may be deteriorated. On the other hand, when it exceeds 4 parts by weight, Image quality defects and white spots may occur due to filming.

  As the charge control agent particles in the present invention, known particles can be used, for example, nigrosine dyes, trifinylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammoniums. Salts (including fluorine-modified quaternary ammonium salts), alkylamides, simple substances or compounds of phosphorus, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, phenolic condensate E- 89 (above, Orient Chemical Industry Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415, zirconium compound TN-105 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LPA-901, LR-146 which is a boron complex (Nippon Carlit) ), Copper phthalocyanine, perylene, quinac Examples thereof include a polymer compound having a functional group such as redone, an azo pigment, and other sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

  The charge control agent is preferably a crystalline compound, and the number average particle size is usually 0.001 to 3 μm, preferably 0.005 to 1 μm, and a plurality of particles having different particle sizes can be blended. The average particle diameter of the solid fine particles can be determined by electron microscope observation, conversion from the value of the BET specific surface area, or the like. These charge control agent particles can also be placed in advance in resin particles containing a colorant for chargeability reinforcement.

  The addition amount of the charge control agent is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, still more preferably 0.1 parts by weight or more, preferably 2 parts by weight with respect to 100 parts by weight of the toner base particles. It is desirable that the amount is not more than parts by weight, more preferably not more than 1 part by weight, still more preferably not more than 0.5 parts by weight. If the addition amount is less than 0.01 parts by weight, the chargeability of the toner is not stable. On the other hand, if it exceeds 2 parts by weight, poor image quality and white spots may occur due to filming.

  As the external addition step of the toner for developing an electrostatic charge image of the present invention, a method in which toner base particles and external additives and / or charge control agents are simultaneously added to the mixing device and mixed and stirred, only the base particles are stirred in advance. There is a method of adding an external additive and / or a charge control agent later, and a method of adding an external additive and / or a charge control agent after stirring only the mother particles in advance is preferable. This is because the external additive efficiency is improved by dispersing the mother particles and raising the surface temperature in advance.

Thus, the toner for developing an electrostatic charge image obtained by the production method of the present invention has a volume average particle diameter (Dv) of preferably 3 μm or more, more preferably 4 μm or more, still more preferably 5 μm or more, preferably 12 μm or less. More preferably, it is 11 μm or less, and further preferably 10 μm or less. If the volume average particle size is less than 3 μm, handling as a powder tends to be difficult, and if the volume average particle size exceeds 10 μm, it may not be suitable for high-resolution image formation.

  Further, a sharp particle size distribution of the electrostatic charge image developing toner tends to make the chargeability between the solid particles more uniform, and is preferable as the electrostatic charge image developing toner for achieving high image quality and high speed. . Specifically, the value (Dv / Dn) obtained by dividing the volume average particle diameter (Dv) by the number average particle diameter (Dn) is preferably 1.0 to 1.25, more preferably 1.0 to 1. 20, More preferably, it is 1.0 to 1.1, and is preferably close to 1.0. As a method for measuring the particle size of the electrostatic image developing toner, a commercially available particle size measuring device can be used, but a precise particle size distribution measuring device Coulter Counter, Multisizer II (manufactured by Beckman Coulter, Inc.) Are preferably used.

  Further, the electrostatic image developing toner obtained by the production method of the present invention preferably has a particle size of 0.6-2.12 μm particles, preferably 15% by number or less, more preferably 10 particles, of the total number of toner particles. % Or less, more preferably 5% by number or less. This means that the amount of fine powder is less than a certain amount, but when the amount of fine powder is small, the fluidity of the toner is improved and the chargeability tends to be uniform. A particle image analyzer can be used as a method for measuring the fine powder content of the electrostatic charge image developing toner, but a flow type particle image analyzer FPIA-2000 (manufactured by Sysmex Corporation) is preferably used. .

  Further, the electrostatic image developing toner obtained by the production method of the present invention preferably has a volume fraction with a particle size of 25 μm or more measured by a Coulter counter, preferably 1% or less, more preferably 0.5% or less, still more preferably. Is preferably 0.1% or less, particularly preferably 0.05% or less. Furthermore, it is desirable that the volume fraction having a particle size of 15 μm or more is preferably 2% or less, more preferably 1% or less, and still more preferably 0.1% or less. This means that the amount of coarse powder is less than a certain amount, but when the amount of coarse powder is small, the amount of toner consumed during continuous development is small and the image quality tends to be stable.

  The electrostatic image developing toner has a 50% circularity measured by using a flow type particle image analyzer FPIA-2000, preferably 0.90 or more, more preferably 0.92 or more, and still more preferably. It is 0.94 or more, preferably 0.98 or less, more preferably 0.96 or less. When the 50% circularity is less than 0.90, there may be an increase in consumption due to defective charging and a decrease in image density. When it exceeds 0.98, there may be a cleaning failure. A method for obtaining such a toner having a 50% circularity is not limited, but it is preferably produced by the emulsion polymerization aggregation method.

  Further, at least one of the peak molecular weights (Mp) in GPC of the THF soluble content of the toner for developing an electrostatic charge image in the present invention is preferably 3000 or more, more preferably 10,000 or more, and further preferably 30,000 or more. Preferably, it is present at 100,000 or less, more preferably 80,000 or less, and still more preferably 70,000 or less. When the peak molecular weight is less than 3000, the offset property on the high temperature side is deteriorated, and when it exceeds 100,000, the offset property on the low temperature side is deteriorated. When the number average molecular weight, weight average molecular weight, and peak molecular weight of the styrenic resin are in the above ranges, the durability, storage stability, and fixability of the toner are improved. Here, as the value in GPC, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement.

Further, the Sp of the electrostatic image developing toner in the present invention is preferably 150 ° C. or less, and more preferably 140 ° C. or less for low energy fixing. Further, from the viewpoint of high temperature offset resistance and durability, the Sp is preferably 80 ° C. or higher, and more preferably 100 ° C. or higher. Here, the Sp is a flow tester (CFT-500 manufactured by Shimadzu Corporation), in which 1.0 g of a sample is a nozzle 1 mm × 10 mm, a load of 30 kg, a preheating time of 50 ° C. for 5 minutes, and a heating rate of 3 ° C./minute. Can be obtained as the temperature at the midpoint of the strand from the start to the end of the flow. Further, the Tg of the toner for developing an electrostatic image in the present invention is preferably 80 ° C. or less, and more preferably 70 ° C. or less for low energy fixing. Moreover, 40 degreeC or more is preferable for blocking resistance, and 50 degreeC or more is more preferable.

  Since the Sp of the toner used in the present invention is greatly affected by the type and composition ratio of the binder resin, it can be adjusted by appropriately optimizing the binder resin. It can also be adjusted by the kind and blending amount of low melting point components such as. In addition, the binder resin used for setting the Sp of the toner of the present invention in the above range can be appropriately selected from commercially available resins.

Further, the charging characteristics of the toner for developing an electrostatic image obtained by the production method of the present invention may be negatively charged or positively charged, and may be set according to the method of the image forming apparatus to be used. it can. The charging characteristics of the toner can be adjusted by the selection and composition ratio of toner base particle components such as a charge control agent, the selection and composition ratio of external additives, and the like.
The toner for developing an electrostatic image obtained by the production method of the present invention is used for a magnetic two-component developer in which magnetic powders such as ferrite and magnetite coexist as a carrier for conveying the toner to an electrostatic latent image portion by magnetic force. Alternatively, it may be used for either a magnetic one-component developer containing such magnetic powder in the toner or a non-magnetic one-component developer that does not use magnetic powder as a developer. In order to exhibit the effect remarkably, it is particularly preferable to use it as a nonmagnetic developer. The toner obtained in the present invention is suitably used as a toner for a non-magnetic one-component developer that is subjected to a load due to contact with a blade or the like during charging because the external additive uniformly and firmly adheres to the toner base particles. be able to.

The electrostatic image developing toner obtained by the production method of the present invention can be suitably used for any of black toner, color toner, and full color toner.
When used as the magnetic two-component developer, the carrier that is mixed with the toner to form the developer may be a known magnetic substance such as an iron powder-based, ferrite-based, or magnetite-based carrier, or the surface thereof. A resin-coated one or a magnetic resin carrier can be used. As the carrier coating resin, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, and the like can be used, but are not limited thereto. It is not a thing. The average particle size of the carrier is not particularly limited, but preferably has an average particle size of 10 to 200 μm. These carriers are preferably used in an amount of 5 to 100 parts by weight with respect to 1 part by weight of the toner.

  Image formation using the toner for developing an electrostatic image obtained by the production method of the present invention can be carried out by a conventional method. Specifically, for example, a charging device, an exposure unit, a developing device that supplies a developer onto the photosensitive member, and an image forming apparatus that includes a fixing device are used to uniformly charge the photosensitive member to form an electrostatic latent image. A desired image is formed by fixing an unfixed image obtained in the process of forming (latent image forming process), developing (developing process) and transferring with toner with a fixing device.

In the image forming method using the electrostatic image developing toner obtained by the production method of the present invention, the developing method is not limited, and may be contact development or non-contact development. The structure of the photoreceptor is not limited, and may be a belt type or a drum type. Also, the material of the photoreceptor is not limited and may be an inorganic compound or an organic compound, but an organic photoreceptor is preferred. When using a non-magnetic one-component image forming apparatus, the developing device is usually composed of a member selected from a toner supply roller, a layer thickness regulating member, a developing roller, a toner stirring member, and the toner of the present invention. A cartridge type can be preferably used.

In the image forming method using the electrostatic image developing toner obtained by the production method of the present invention, the transfer method is not limited, and an intermediate transfer member may be used. The fixing method is not limited, but fixing by a thermocompression bonding method is preferable.
As described above, according to the method for producing a toner for developing an electrostatic charge image of the present invention, the toner base particles can be efficiently coated with the external additive and / or the charge control agent, and the obtained electrostatic charge can be coated. Image development toner has stable adhesion of external additives and / or charge control agents on the surface of the toner particles, and the toner has good fluidity and charge stability. It has an excellent quality that there is little decrease in performance and good blocking resistance.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the following examples, “parts” means “parts by weight”. In addition, the live-action test was conducted by the following method.
<Production of polymer primary particle dispersion A>
The following polylactone dispersion A, wax dispersion A, and demineralized water are charged into a reactor equipped with a stirrer, heating / cooling device, concentrating device, and each raw material / additive charging device, and heated to 90 ° C. under a nitrogen stream. The temperature rose.

Polylactone dispersion A 20 parts Wax dispersion A 1 part Demineralized water 365 parts Next, with the temperature of the reactor maintained at 90 ° C, a mixture comprising the following monomers, an emulsifier aqueous solution, a polymerization initiator, etc. was taken over 5 hours. In addition, the polylactone particles and the wax particles were used as seeds for emulsion copolymerization.
[Monomers]
Styrene 79 parts Butyl acrylate 21 parts Acrylic acid 3 parts 1,6-hexanediol diacrylate 1 part Trichlorobromomethane (chain transfer agent) 1.3 parts [Emulsifier aqueous solution]
10 parts of 10% emulsifier (neogen SC) aqueous solution [initiator aqueous solution]
43 parts of 8% aqueous hydrogen peroxide solution 43 parts of 8% aqueous ascorbic acid solution After that, primary particle dispersion A of styrene-butyl acrylate-acrylic acid copolymer was obtained by cooling. The volume average particle diameter of the particles measured with Nikkiso Microtrac UPA was 0.26 μm.

<Preparation of Colorant Dispersion A>
Pigment Blue 15: 3 (Clariant Japan, Hostaperm Blue B2G) 20 parts, anionic surfactant (Daiichi Kogyo Seiyaku, Neogen SC) 1 part, nonionic surfactant (Daiichi Kogyo Seiyaku, 5 parts of Neugen EA80) and 80 parts of water were dispersed with a sand grinder mill to obtain a black colorant dispersion A. The volume average particle diameter measured by Microtrac UPA was 0.15 μm.

<Manufacture of toner mother particle A>
While adding 6 parts of the colorant dispersion A to 100 parts of the polymer primary particle dispersion A obtained above, and dispersing and stirring with a disperser, the aqueous solution of aluminum sulfate (solid content with respect to 100 parts of the primary particle dispersion A) 0.5 parts) was added dropwise, the temperature was raised to 50 ° C. over 30 minutes with stirring and held for 1 hour, and further the temperature was raised to 52 ° C. with stirring to perform the aggregation step. When the volume average particle size as the primary particle aggregate is about 7 μm, the aqueous solution of Neogen SC (3 parts as solid content with respect to 100 parts of the primary particle dispersion A) is added to complete the aggregation process, followed by stirring. The temperature was raised to 97 ° C. over 50 minutes and held for 1.5 hours to carry out the aging step. Thereafter, cooling, filtration, washing with water, and drying were performed to obtain cyan toner mother particles A as primary particle aggregates / ripened bodies.

The cyan toner base particle A had an Sp of 130 ° C., a volume average particle diameter of the toner measured by a Coulter counter of 7.1 μm (variation coefficient 25%), and a volume fraction of 25 μm or more was 0.01%. Moreover, the 50% circularity was 0.96 as measured by a flow type particle image analyzer FPIA-2000. Furthermore, the endothermic maximum point temperature by the DSC method was 65 ° C.
<Toner base particle B>
Polyester resin FC1198 (Mitsubishi Rayon Co., Ltd.) 100 parts by weight Colorant Pigment Blue 15: 3 8 parts by weight Charge control agent E84 (manufactured by Orient Chemical Co., Ltd.) 2 parts by weight Wax Umex 100TS (manufactured by Sanyo Chemical Co., Ltd.) 3 parts by weight or more of materials were mixed with a mixer, then kneaded with a biaxial kneader (PCM-30 manufactured by Ikekai Tekko), pulverized with a jet mill, and classified to obtain cyan toner base particles B.
The cyan toner base particle B has a softening point of 139 ° C., a glass transition point of 65.7 ° C., a volume average particle size of the toner measured by a Coulter counter is 8.0 μm, and a volume fraction of 25 μm or more is 0.00
%Met. Further, the shape was measured by a flow type particle image analyzer FPIA-2000, and the 50% circularity was 0.92. Further, the endothermic maximum point temperature by the DSC method was 63 ° C.

<Example 1>
In the mixing device (schematic diagram shown in FIG. 1) provided with a fixing member A (1.6% of the surface area of the fixing member, vertically attached to the wall surface) on the inner wall of the Q mixer (Mitsui Mining Co., Ltd.) 100 parts of toner base particles A, 2.0 parts of silica fine particles having an average primary particle size of 0.04 μm hydrophobized with silicone oil, and silica fine particles having an average primary particle diameter of 0.012 μm hydrophobized with silicone oil After adding 5 parts, the mixture was stirred. The total bulk volume of the particles relative to the internal volume of the mixing apparatus was 25% by volume. At this time, the temperature of the toner base particles A and silica was 23 ° C. Mixing was started at a rotating peripheral speed of the stirring blade of 100 m / s. After the mixing time of 4 minutes, the rotational speed was lowered to 87 m / s and mixing was performed so that the internal temperature did not exceed 50 ° C. The internal temperature of the mixing chamber changed as shown in FIG. 3, and after 6 minutes of operation, an electrostatic charge image developing toner was obtained. During mixing, water of 18 ° C. was passed through the jacket of the mixing apparatus. The maximum temperature in the apparatus was 49 ° C., and the maximum rising rate was 20 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the following method.

[Image density (ID)]
The toner obtained above was mounted on a non-magnetic one-component full-color printer having an organic photoconductor (OPC) photoconductor, and a single color image was taken, and image evaluation was performed according to the following method. The evaluation was made based on the initial printing (fifth sheet) image.
A solid portion printed with an image pattern having a solid solid portion was measured with X-lite 936 (light source C2, A response) manufactured by Nippon Flat Plate Equipment Co., Ltd. The evaluation criteria are as follows.

◎: 1.4 or more (very good)
○: 1.2 or more and less than 1.4 (good)
Δ: 1.0 or more and less than 1.2 (can be used)
×: Less than 1.0 (use hindered)
[Toner consumption]
Printing was performed in the same manner as the evaluation of image density, and after 6,000 sheets were printed, consumption was evaluated according to the following criteria.

: Less than 30 g / kp (very good)
○: Less than 36 g / kp 30 g / kp or more (good)
Δ: Less than 50 g / kp 36 g / kp or more (usable)
×: 50 g / kp or more (useful)
<Example 2>
Of the raw materials, the mother particles are changed to toner mother particles B and mixing is started at a rotating peripheral speed of the stirring blade of 100 m / s. After the mixing time of 4 minutes, the rotating peripheral speed is reduced to 60 m / s and the continuous mixing time is 5 minutes. Except for the above, mixing was performed under the same conditions as in Example 1 to obtain an electrostatic image developing toner. When mixing the raw materials, the temperature of the toner base particles B and silica was 26 ° C. The jacket of the mixing apparatus passed water at 18 ° C. The maximum temperature inside the apparatus was 55 ° C., and the maximum rate of increase was 24 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative Example 1>
The same raw material as in Example 2 was charged into a mixing apparatus in which a fixing member B (surface area 1.2%, perpendicular to the lateral wall surface) was provided on the inner wall of a Henschel mixer (Mitsui Mining Co., Ltd.). The total bulk volume of the particles relative to the internal volume of the mixing apparatus was 42% by volume. At this time, the temperature of the toner base particles B and silica was 26 ° C. Mixing was performed at a rotational peripheral speed of the stirring blade of 60 m / s. After running for 15 minutes, an electrostatic image developing toner was obtained. During mixing, water of 18 ° C. was passed through the jacket of the mixing apparatus. The maximum temperature of the internal temperature of the apparatus was 50 ° C., and the maximum increase rate was 6 ° C./min. Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative example 2>
Among the raw materials, mixing is performed under the same conditions as in Comparative Example 1 except that the mother particles are changed to toner mother particles A, the rotating peripheral speed of the stirring blade is 80 m / s, and the continuous mixing time is 5 minutes. Toner was obtained. When mixing the raw materials, the temperature of the toner base particles A and silica was 26 ° C. The jacket of the mixing apparatus passed water at 18 ° C. The maximum temperature inside the apparatus was 57 ° C., and the maximum rising speed was 7 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative Example 3>
Mixing was performed under the same conditions as in Comparative Example 2 except that the rotating peripheral speed of the stirring blade was 60 m / s and the continuous mixing time was 15 minutes, to obtain a toner for developing an electrostatic image. When mixing the raw materials, the temperature of the toner base particles A and silica was 26 ° C. The jacket of the mixing apparatus passed water at 18 ° C. The maximum temperature of the apparatus internal temperature was 45 ° C., and the maximum rising rate was 4 ° C./min. Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative example 4>
A toner for developing an electrostatic charge image was obtained by mixing under the same conditions as in Comparative Example 3 except that the continuous mixing time was 13 minutes. When mixing the raw materials, the temperature of the toner base particles A and silica was 26 ° C. The jacket of the mixing device did not pass water. The maximum temperature inside the apparatus was 47 ° C., and the maximum rate of increase was 5 ° C./min. Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative Example 5>
A toner for developing an electrostatic image was obtained by mixing under the same conditions as in Comparative Example 4 except that the continuous mixing time was 4 minutes. When mixing the raw materials, the temperature of the toner base particles A and silica was 26 ° C. The jacket of the mixing apparatus passed hot water of 45 ° C. The maximum temperature in the apparatus was 57 ° C., and the maximum rate of increase was 8 ° C./min. Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Example 3>
Mixing was performed under the same conditions as in Example 1 except that the fixing member was not provided and the continuous mixing time was 4 minutes at a rotating peripheral speed of the stirring blade of 100 m / s, to obtain an electrostatic image developing toner. When mixing the raw materials, the temperature of the toner base particles A and silica was 23 ° C. During mixing, the jacket of the mixing apparatus passed water at 18 ° C. The maximum temperature inside the apparatus was 40 ° C., and the maximum rate of increase was 9 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.
<Example 4>
Except that no water was passed through the jacket of the mixing apparatus, mixing was performed under the same conditions as in Example 1 to obtain an electrostatic image developing toner. When mixing the raw materials, the temperature of the toner base particles A and silica was 23 ° C. The maximum temperature of the apparatus internal temperature was 60 ° C., and the maximum rising rate was 20 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative Example 6>
Mixing was carried out under the same conditions as in Example 1 except that the continuous mixing time was 1 minute at a rotating blade speed of 100 m / s, to obtain an electrostatic image developing toner. When mixing the raw materials, the temperature of the toner base particles A and silica was 23 ° C. During mixing, the jacket of the mixing apparatus passed water at 18 ° C. The maximum temperature inside the apparatus was 38 ° C., and the maximum rate of increase was 20 ° C./min.
Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

<Comparative Example 7>
Mixing was performed under the same conditions as in Comparative Example 1 except that the rotating peripheral speed of the stirring blade was 80 m / s and the continuous mixing time was 8 minutes. During mixing, water of 18 ° C. was passed through the jacket of the mixing apparatus. However, after mixing, a lump of toner was generated in the mixing apparatus, and performance evaluation could not be performed.

<Comparative Example 8>
The external addition process was performed under the same conditions as in Comparative Example 4 except that the rotating peripheral speed of the stirring blade was 40 m / s and the operation was performed for 20 minutes. The maximum temperature in the apparatus was 35 ° C., and the maximum rate of increase was 1 ° C./min or less. Table 1 shows the results of image density (ID) and toner consumption evaluated by the same method as in Example 1.

It is a conceptual diagram of the mixing apparatus used for this invention. It is a conceptual diagram of the mixing apparatus used for this invention. It is a figure which shows the change of the apparatus internal temperature in mixing in Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mixing chamber 2 Jacket 3 Flange 4 Input port 5 Outlet port 6 Stirring blade 7 Temperature sensor 8 Drive shaft 9 Boss 10 Auxiliary blade 11 Fixing member

Claims (6)

  In the method for producing a toner for developing an electrostatic charge image in which an external additive and / or a charge control agent is mixed with toner base particles containing a binder resin and a colorant, the mixing is performed by a mixing device having a stirring blade, and When the maximum rising speed of the mixing device internal temperature is A (° C./min) and the continuous mixing time is B (min), (1) 30 ≦ A × B and (2) 9 ≦ A ≦ 60 are satisfied, and And a method for producing a toner for developing an electrostatic charge image, wherein the mixing is performed under a condition that the internal temperature of the mixing device does not rise above the endothermic maximum point temperature by DSC of the toner base particles.   2. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the increase in the internal temperature of the mixing device is not caused by external heat supply.   The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein an increase in the internal temperature of the mixing device is suppressed.   4. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein a fixing member protruding from an inner wall of the mixing device is provided.   5. The electrostatic charge image developing device according to claim 1, wherein the ratio of the surface area of the fixing member protruding to the inner wall of the mixing apparatus is 0.1 to 20% with respect to 100% of the surface area of the inner wall of the apparatus. Toner manufacturing method.   6. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the endothermic maximum point temperature of the toner base particles by DSC is 55 to 100.degree.

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