JP2004012650A - Method for manufacturing electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrostatic charge image developing toner capable of controlling the shape and particle size distribution of particle agglomerates, imparting sharpness to the particle size distribution of toner particles, capable of attaining the objective circularity in a short period of time and ensuring a small amount of coarse powder produced in aging. <P>SOLUTION: In the method for manufacturing the toner including an agglomeration step in which polymer primary particles are agglomerated in a dispersion containing the particles and a colorant and an aging step in which fusion between particles in the resulting particle agglomerates is caused, polymer primary particles are additionally added in the agglomeration step. <P>COPYRIGHT: (C)2004,JPO

Description

【００９６】
上記の結果から、本発明により、凝集工程での粒子凝集体の形状及び粒度分布を制御することができ、トナー粒子の粒度分布がシャープとなり、短時間で目標円形度にすることができ、しかも熟成時の粗粉の発生量も少ないことが分かる。
【００９７】
【発明の効果】
本発明により、粒子凝集体の形状及び粒度分布を制御することができ、トナー粒子の粒度分布がシャープとなり、短時間で目標円形度にすることができ、しかも熟成時の粗粉の発生量も少ない。
また、本発明で製造された静電荷像現像用トナーは、小粒径であり、かつ粒度分布がシャープであるので、高画像及び高画質に適している。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a toner for developing an electrostatic image. More specifically, the present invention relates to a method for producing an electrostatic image developing toner used in an electrophotographic copying machine and a printer. More specifically, the present invention relates to a method for producing a toner for developing an electrostatic charge image, in which the shape and particle size distribution of particle aggregates of polymer primary particles are controlled, the particle size distribution is narrower, and the shape can be easily controlled.
[0002]
[Prior art]
Conventionally, the toner for developing an electrostatic image, which has been widely used in electrophotography, comprises a binder such as styrene / acrylate copolymer or polyester, a coloring agent such as carbon black or a pigment, and a charge if necessary. It has been manufactured by melt-kneading a mixture obtained by adding a control agent and a magnetic substance with an extruder, followed by pulverization and classification. However, the conventional toner obtained by the above-described melt-kneading and pulverizing method has a limitation in controlling the particle size of the toner, and it is possible to produce a toner having an average particle size of substantially 10 μm or less, particularly 8 μm or less with a high yield. It was difficult and could not be said to be enough to achieve the high resolution required for electrophotography in the future.
[0003]
Further, in order to achieve low-temperature fixability, a method has been proposed in which a wax having a low softening point is blended into a toner at the time of melt-kneading. A toner having excellent low-temperature fixing performance could not be obtained. Also, when flakes obtained after melt-kneading are mechanically pulverized into toner, the yield is poor and the particle size distribution is wide. This tendency is remarkable especially when a toner having a small particle diameter is to be obtained.
[0004]
On the other hand, in recent years, a method of producing a polymerized toner by an emulsion polymerization aggregation method, a suspension polymerization method, or the like has been known as a production method replacing the melt-kneading-pulverization method. If these methods are used, the dispersion of the raw materials can be controlled unlike the melt-kneading and pulverizing method. In particular, in the emulsion polymerization aggregation method, the particle size, the particle size distribution, and the toner shape can be controlled.
When a toner is produced by an emulsion polymerization aggregation method, a pigment, a charge controlling agent, and the like are added to an emulsified dispersion containing primary polymer particles having a particle diameter of 0.05 μm to 0.5 μm obtained by emulsion polymerization, and a charge material is further added. And the like to aggregate the polymer primary particles into particle aggregates of 3 to 9 μm, which are then heated at a temperature equal to or higher than the glass transition temperature (Tg) of the polymer primary particles to form particles on the surface and inside of the particle aggregates. The toner particles are aged by fusing to obtain toner particles. Finally, the toner particle slurry is washed and dried to obtain product toner particles. Here, the shape of the toner particles, which has an important effect on the properties of the toner, is controlled by an aging process at a high temperature.
[0005]
However, in this method, the particle aggregate obtained in the aggregation step generally has a wide particle size distribution and a low circularity of the particle aggregate. In the case of a particle aggregate having a higher glass transition temperature (Tg), the particle aggregate is less likely to be deformed at the time of aging, and fusion between particles becomes difficult. Therefore, the toner obtained by this method has a problem that the particle size distribution is wide and the shape control is difficult, the strength of the toner particles is weak, fine powder is easily generated, and the image quality is affected.
[0006]
[Problems to be solved by the invention]
In view of the above problems of the prior art, an object of the present invention is to control the shape and particle size distribution of the particle aggregates of the polymer primary particles, and to easily control the shape and particle size distribution of the toner particles for electrostatic image development. An object of the present invention is to provide a method for producing a toner.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that the problems can be solved by additionally adding polymer primary particles in the aggregation step, and have reached the present invention.
That is, the gist of the present invention is to produce a toner including an aggregation step of aggregating particles in a dispersion containing primary polymer particles and a colorant, and an aging step of causing fusion between particles in the obtained particle aggregate. A method for producing a toner for developing electrostatic images, characterized by additionally adding polymer primary particles during the aggregation step.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
The toner for developing an electrostatic image obtained according to the present invention contains, as essential components, primary particles of a polymer and fine particles of a colorant resin, and if necessary, a particle containing a wax, a charge control agent, and other additives. Things.
[0009]
The toner of the present invention is usually produced by an emulsion polymerization aggregation method. In the emulsion polymerization agglomeration method, at least the polymer primary particles and colorant primary particles obtained by emulsion polymerization, and if necessary, the charge control agent primary particles and the like are coaggregated to form a particle aggregate, and further resin fine particles and the like. The toner is manufactured by attaching or sticking.
First, the emulsion polymerization step for producing the polymer primary particles used in the present invention will be described.
[0010]
In the emulsion polymerization step, by sequentially adding the monomer to the aqueous medium containing the emulsifier and the polymerization initiator, the polymerization of the monomer proceeds in the emulsion to produce an emulsion polymerization latex containing polymer primary particles. I do.
As the emulsifier, a known surfactant such as a cationic surfactant, an anionic surfactant, and a nonionic surfactant is used. Two or more of these surfactants may be used in combination.
[0011]
Specific examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.
Specific examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium lauryl sulfate and the like.
[0012]
Further, specific examples of the nonionic surfactant include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, and monodecanoyl. Sucrose and the like.
In carrying out the emulsion polymerization, a monomer having a Bronsted acidic group (hereinafter, also simply referred to as an acidic group) or a monomer having a Bronsted basic group (hereinafter, also simply referred to as a basic group) and a Bronsted acidic group are successively used. Alternatively, by adding a monomer having no Bronsted basic group (hereinafter, also referred to as other monomer), the polymerization proceeds. At this time, the monomers may be added separately, or a plurality of monomers may be mixed in advance and then added. Further, the monomer composition can be changed during the addition of the monomer. Further, the monomer may be added as it is, or may be added as an emulsified liquid which is previously mixed and adjusted with water or an emulsifier. As the emulsifier, one or a combination of two or more of the above surfactants is selected.
[0013]
Examples of the monomer having a Bronsted acidic group 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 vinylbenzenesulfonamide. And the like having a sulfonamide group.
Examples of the monomer having a Bronsted basic group include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic-containing monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, and diethylaminoethyl methacrylate. (Meth) acrylate having an amino group of
[0014]
The monomer having an acidic group and the monomer having a basic group may each be present as a salt with a counter ion.
The blending ratio of the monomer having a Bronsted acidic group or a Bronsted basic group in the monomer mixture constituting the polymer primary particles is preferably 0.5% by weight or more, more preferably 1% by weight or more. And preferably 10% by weight or less, more preferably 5% by weight or less.
[0015]
Examples of the other monomers include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, pt-butylstyrene, pn-butylstyrene, and pn-nonylstyrene, methyl acrylate, and ethyl acrylate. , Propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate (Meth) acrylic acid esters such as ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutylacrylamide , It may be mentioned acrylic acid amide or the like. Among them, styrene, butyl acrylate and the like are particularly preferable.
[0016]
The resin used for the polymer primary particles is preferably a crosslinked resin. Crosslinking is performed by blending a monomer having at least two functional groups (polyfunctional monomer).
When a crosslinked resin is used for the polymer primary particles, a polyfunctional monomer having radical polymerizability is used as a crosslinker used in combination with the above-described monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, Examples thereof include diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, and diallyl phthalate. It is also possible to use a monomer having a reactive group in the pendant group, for example, glycidyl methacrylate, methylolacrylamide, acrolein and the like.
[0017]
The compounding ratio of such a polyfunctional monomer in the monomer mixture is preferably 0.005% by weight or more, more preferably 0.01% by weight or more, and further preferably 0.05% by weight or more. It is preferably at most 5% by weight, more preferably at most 3% by weight, further preferably at most 1% by weight.
These monomers may be used alone or as a mixture. In this case, the glass transition temperature of the polymer is preferably 40 to 80 ° C. If the glass transition temperature exceeds 80 ° C., the fixing temperature may become too high, or the OHP transparency may deteriorate. On the other hand, if the glass transition temperature of the polymer is less than 40 ° C., the storage stability of the toner may be reduced. May worsen.
[0018]
A known water-soluble polymerization initiator can be used as the polymerization initiator when performing the emulsion polymerization. Specifically, for example, persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, and a redox initiator in which these persulfates are combined as a component with a reducing agent such as sodium acid sulfite, hydrogen peroxide, Water-soluble polymerization initiators such as 4,4'-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, and a redox initiator obtained by combining these water-soluble polymerization initiators as one component with a reducing agent such as a ferrous salt System, benzoyl peroxide, 2,2'-azobisisobutyronitrile and the like are used.
[0019]
These polymerization initiators may be added to the polymerization system at any time before, at the same time as, or after the addition of the monomers, and these addition methods may be combined as necessary.
In the above method, a known chain transfer agent can be used if necessary. Specific examples of such a chain transfer agent include t-dodecylmercaptan, 2-mercaptoethanol, diisopropylxanthogen, and tetrachloride. Carbon, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more kinds, and is usually used in the range of 0 to 5 parts by weight based on 100 parts by weight of the monomer.
[0020]
When the wax is contained in the toner particles as described above, the wax may be added in the coagulation step described later, but is preferably added in the emulsion polymerization step so that the primary polymer particles themselves contain the wax. As the method, a method in which wax is dissolved in a monomer and emulsion polymerization is performed, or more preferably, a method in which a wax mixture obtained by emulsification in the presence of an emulsifier is used as a seed and a monomer mixture is subjected to seed emulsion polymerization. And the like.
[0021]
As the wax, any known wax can be used. Specifically, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; ester waxes having a long-chain aliphatic group such as behenyl behenate, montanic acid ester, and stearyl stearate; Vegetable waxes such as castor oil and carnauba wax; ketones having a long-chain alkyl group such as distearyl ketone; silicones having an alkyl group; higher fatty acids such as stearic acid; long-chain aliphatic alcohols such as eicosanol; glycerin, pentaerythritol and the like Carboxylic acid esters or partial esters of polyhydric alcohols obtained from polyhydric alcohols and long-chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; and low molecular weight polyesters.
[0022]
In order to improve the fixing property among these waxes, the melting point of the wax is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and even more preferably 50 ° C. or higher. Further, the temperature is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, and further preferably 80 ° C. or lower. If the melting point is too low, the wax is exposed to the surface after fixing, and stickiness tends to occur. If the melting point is too high, the fixability at low temperatures tends to be poor.
[0023]
Further, as the compound species of the wax, an ester wax obtained from an aliphatic carboxylic acid and a monohydric or polyhydric alcohol is preferable, and among the ester waxes, those having 20 to 100 carbon atoms are more preferable, and those having carbon atoms of 20 to 100 are preferable. Those having 30 to 60 are more preferred.
Among the esters of monohydric alcohols and aliphatic carboxylic acids, particularly preferred compounds include behenyl behenate and stearyl stearate. Among the esters of polyhydric alcohol and aliphatic carboxylic acid, particularly preferred compounds include stearic acid ester of pentaerythritol and its partial ester, montanic acid ester of glycerin and its partial ester.
[0024]
The waxes may be used alone or as a mixture. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature for fixing the product toner.
In order to enhance the fixability, it is effective to use a mixture of two or more, preferably three or more waxes. Above all, it is preferable to use three or more kinds of wax compounds in combination, and to mix any of the wax compounds so as not to exceed 60% by weight based on the whole wax. It is more preferable that the content is not more than 45% by weight, more preferably not more than 40% by weight.
[0025]
At least one of the wax compounds used in combination is preferably a carboxylic acid ester of the above-mentioned monohydric or polyhydric alcohol. Further, the wax compound having the largest content is more preferably an alkanoic acid ester of a monohydric or polyhydric alcohol, and further preferably an alkanoic acid alkyl ester. When the wax compound having the largest content is an alkyl ester of an alkanoic acid, the second largest amount of the wax compound may be another alkyl alkanoate or an alkanoate of a polyhydric alcohol. preferable.
[0026]
Further, the type of the wax compound used in combination is preferably 4 or more, and more preferably 5 or more. The upper limit of the type of the wax compound used in combination is not particularly limited, but is preferably 50 or less in terms of production.
In addition, the sum of two wax compounds having a large blending amount among the at least three wax compounds is preferably 88% by weight or less, more preferably 85% by weight or less, based on the whole wax. , 80% by weight or less.
[0027]
In addition, the melting point of the wax compound having the largest amount is preferably 40 ° C. or higher, more preferably 50 ° C. or higher. Further, those having a temperature of 90 ° C. or lower are preferable, and those having a temperature of 80 ° C. or lower are more preferable. Further, it is more preferable that the melting points of the two wax compounds having a large blending amount are both 40 ° C. or more and 90 ° C. or less.
The toner obtained from the polymer primary particles obtained by the method of seed emulsion polymerization of the monomer mixture using the wax fine particles as a seed as described above has a structure in which the wax fine particles are relatively uniformly distributed in the toner. If the wax component has a relatively wide temperature range from the start to the end of the melting, that is, if the mixture is a mixture and the purity is low, even if the fixing temperature changes, the wax is discharged from the toner at the time of fixing even if the fixing temperature changes. It is presumed that the toner is good, and that the fixing property is good.
[0028]
The wax fine particles can be obtained by emulsifying the wax in the presence of an emulsifier such as a known cationic surfactant, anionic surfactant, or nonionic surfactant as described above. Two or more of these surfactants may be used in combination. At this time, it is preferable to emulsify at a temperature higher than the melting point of the wax. When the melting point of the wax is equal to or higher than the melting point of the wax, the wax is melted to form droplets in water, and a dispersion of substantially spherical wax fine particles can be obtained.
[0029]
The average particle diameter of the wax fine particles is preferably 0.01 to 3 μm, more preferably 0.1 to 2 μm, and still more preferably 0.3 to 1.5 μm. The average particle diameter can be measured using, for example, LA-500 manufactured by Horiba.
When the average particle size of the wax emulsion is larger than 3 μm, the average particle size of the polymer particles obtained by seed polymerization tends to be too large. When the average particle size of the emulsion is smaller than 0.01 μm, it is generally difficult to prepare a dispersion.
[0030]
The wax-containing polymer primary particles obtained by seed emulsion polymerization as described above are polymer particles substantially containing wax, and as a morphology, core-shell type, phase separation type, Any form such as an occlusion type may be used, and a mixture of these forms may be used. Particularly preferred is the core-shell type.
[0031]
In addition, when the wax content in the toner is to be increased, for example, when the wax fine particles used in the production of the polymer primary particles have a small particle diameter, the polymer primary particles are aggregated in the aggregation step described below. At this time, another wax fine particle can be co-aggregated. However, in consideration of the dispersibility of the wax fine particles in the toner, it is preferable to use substantially all of the wax contained in the primary polymer particles.
[0032]
When obtaining polymer primary particles, the colorant fine particles may be used as seeds for emulsion polymerization simultaneously with the wax fine particles, or the colorant may be used by dissolving or dispersing it in a monomer or wax. At the same time, it is preferable that the colorant fine particles are aggregated to form a particle aggregate, thereby forming a toner core material. At this time, polymer primary particles containing a wax are used, but two or more types of polymer primary particles may be used as necessary. The colorant used here may be any of an inorganic pigment, an organic pigment, an organic dye, or a combination thereof.
[0033]
The volume average particle size of the polymer primary particles obtained by emulsion polymerization is generally in the range of 0.02 to 3 μm, preferably 0.05 to 3 μm, more preferably 0.1 to 2 μm, and further preferably It is 0.1 to 1 μm. The average particle size can be measured, for example, using a Microtrack UPA manufactured by Nikkiso Co., Ltd. When the average particle size is smaller than 0.02 μm, it becomes difficult to control the aggregation speed. If it is larger than 3 μm, the particle size of the toner obtained by aggregation may be too large.
[0034]
The tetrohydrofuran insoluble content of the polymer primary particles is preferably 15 to 80% by weight. When a crosslinked resin is used for the polymer primary particles, the content of tetrahydrofuran insoluble in the polymer primary particles is preferably 15% by weight or more, more preferably 20% by weight or more, and further preferably 25% by weight or more. Further, it is preferably at most 80% by weight, more preferably at most 70% by weight. When the tetrahydrofuran insoluble content is in the above range, offset resistance and OHP transparency tend to be excellent.
[0035]
Among the components constituting the polymer primary particles, the molecular weight peak (Mp) of the tetrahydrofuran-soluble component is preferably 30,000 or more, more preferably 40,000 or more. Moreover, 150,000 or less is preferable, and 100,000 or less is more preferable. In particular, when a crosslinked resin is used, the molecular weight peak is preferably 100,000 or less, more preferably 60,000 or less. If the molecular weight peak is significantly smaller than the above range, the offset property on the high-temperature side will be poor, and if it is significantly larger than the above range, the offset property on the low-temperature side will tend to be poor.
[0036]
Further, among the components constituting the polymer primary particles, the weight average molecular weight (Mw) of the tetrahydrofuran-soluble component is preferably 30,000 or more, more preferably 80,000 or more. Further, it is preferably at most 500,000, more preferably at most 300,000.
Next, the aggregation step will be described.
[0037]
In the aggregation step, the colorant primary particles, and, if necessary, the charge control agent fine particles, the wax fine particles, and other internal additives are emulsified, added to the emulsion polymerization latex containing the polymer primary particles, and dispersed. Coaggregation is caused in the polymer primary particle-containing dispersion obtained by the above-mentioned process to form a particle aggregate.
Specific examples of the coloring agent include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, and monoazo dyes. Any known dyes and pigments such as azo, disazo and condensed azo dyes can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, monoazo-based and condensed azo-based dyes and pigments for yellow, quinacridone and monoazo-based dyes and pigments for magenta, and phthalocyanine blue for cyan, respectively. The colorant is usually used in an amount of 3 to 20 parts by weight based on 100 parts by weight of the binder resin. The “binder resin” means a combination of a resin component constituting the polymer primary particles and a resin component constituting the resin fine particles.
[0038]
In the present invention, as a preferred embodiment for obtaining a particle aggregate (toner core material), there is a method for obtaining a particle aggregate by coaggregating the above-mentioned polymer primary particles and colorant primary particles.
As the colorant primary particles, it is preferable to use those obtained by emulsifying an organic pigment substantially insoluble in water in water in the presence of an emulsifier to form an emulsion, and in this case, the volume of the colorant primary particles The average particle size is preferably from 0.01 to 3 μm.
[0039]
In the present invention, a charge control agent can be contained in the toner as needed. As a method, when obtaining polymer primary particles in the emulsion polymerization step, the charge control agent is used as a seed simultaneously with the wax, or the charge control agent is used by being dissolved or dispersed in a monomer or wax, or in the aggregation step. The toner may be formed by aggregating the primary particles of the charge control agent at the same time as the primary particles of the polymer to form a particle aggregate, or may be used before or simultaneously with or simultaneously with the step of attaching or fixing the resin fine particles. After the step, it is preferable to attach or fix the primary particles of the charge control agent. In this case, the charge control agent is also preferably used as an emulsion (primary particles of the charge control agent) having an average particle size of 0.01 to 3 μm in water.
[0040]
As the charge control agent, any known charge control agent can be used alone or in combination. For example, a quaternary ammonium salt and a basic / electron-donating metal substance can be used as the positively chargeable charge control agent, and metal chelates, metal salts of organic acids, metal-containing dyes, nigrosine dyes can be used as the negatively chargeable charge control agent. Amide group-containing compounds, phenol compounds, naphthol compounds and metal salts thereof, urethane bond-containing compounds, and acidic or electron-withdrawing organic substances.
[0041]
In consideration of the color toner adaptability (the charge control agent itself is colorless or light-colored and there is no color hindrance to the toner), the quaternary ammonium salt compound is used as the positive charge control agent, and the negative charge control agent is used. Metal salts of salicylic acid or alkyl salicylic acid with chromium, zinc or aluminum, metal complexes, metal salts of benzylic acid, metal complexes, amide compounds, phenol compounds, naphthol compounds, phenolamide compounds, 4,4′-methylenebis Hydroxynaphthalene compounds such as [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] are preferred. The amount used may be determined depending on the desired charge amount of the toner, and is usually 0.01 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the binder resin.
[0042]
In the present invention, the toner can also be obtained by aggregating primary polymer particles into a particle aggregate, and adhering or fixing resin fine particles described later thereto. Depending on the toner manufacturing conditions, there are cases where the primary particles in the toner can be observed, and cases where the primary particles are fused and the original primary particles cannot be observed.
In a preferred embodiment of the present invention, the polymer primary particles and the resin fine particles are fused to form a shape in which the boundaries are unclear or boundaries are not recognized.
[0043]
In another preferred embodiment, a crosslinked resin is used for one or both of the polymer primary particles and the resin fine particles covering the particle aggregate, and has a tetrahydrofuran-insoluble content.
The resin fine particles are dispersed in water or a liquid mainly composed of water using an emulsifier such as the above-mentioned surfactant and used as an emulsion. The resin fine particles are preferably obtained by emulsion polymerization.
[0044]
The resin fine particles preferably do not substantially contain wax. In addition, substantially containing no wax means that the wax content in the resin fine particles is 1% by weight or less, preferably 0.5% by weight or less, more preferably 0.1% by weight or less. . When the resin fine particles do not substantially contain wax, it is difficult for the wax to leach to the toner surface portion before the toner is fixed by the fixing device, and it is possible to prevent the device from being stained and to have good blocking resistance. Become.
[0045]
The resin fine particles preferably have a volume average particle size of 0.02 to 3 μm, more preferably 0.05 to 1.5 μm, and are obtained by polymerizing a monomer similar to the monomer used for the aforementioned polymer primary particles. Those obtained can be used.
The resin used for the resin fine particles is preferably crosslinked. As the crosslinking agent, the polyfunctional monomer used for the above-mentioned polymer primary particles can be used.
[0046]
When a crosslinked resin is used as the resin fine particles, the degree of crosslinking is usually at least 5 polymer%, preferably at least 10 polymer%, more preferably at least 15 polymer%, even more preferably at least 60 polymer% as the tetrahydrofuran insoluble matter. Also, it is usually 70% by polymerization or less. In order to make the tetrahydrofuran-insoluble content within the above preferred range, the blending ratio of the polyfunctional monomer is preferably 0.005% by weight or more, more preferably 0.01% by weight or more in the monomer mixture used for the resin fine particles. , 0.05% by weight or more is more preferable. Further, it is preferably at most 5% by weight, more preferably at most 3% by weight, further preferably at most 1% by weight.
[0047]
Among the components constituting the resin fine particles, the molecular weight peak (Mp) of the tetrahydrofuran-soluble component is preferably 30,000 or more, more preferably 40,000 or more. Moreover, 150,000 or less is preferable, and 100,000 or less is more preferable. In particular, when a crosslinked resin is used, the molecular weight peak is preferably 100,000 or less, more preferably 60,000 or less.
[0048]
Further, among the components constituting the resin fine particles, the weight average molecular weight (Mw) of the tetrahydrofuran-soluble component is preferably 30,000 or more, more preferably 50,000 or more. Further, it is preferably at most 500,000, more preferably at most 300,000.
The present invention is characterized in that polymer primary particles are additionally added during the aggregation step.
[0049]
In a preferred embodiment of the aggregation step of the present invention, the above-mentioned polymer primary particles, colorant primary particles, and, if necessary, charge control agent fine particles, wax fine particles, and other internal additives, are each emulsified to form an emulsion. Further, the polymer primary particles are coagulated while being added plural times or continuously and added to form a particle aggregate. Usually, the intermittent addition is preferable since the particle size distribution of the particle aggregate becomes sharper than the case of the continuous addition. In the case of continuous addition, it is preferable to perform the addition so that the total addition time accounts for one third or more of the total aggregation time. Among the components for performing aggregation, the charge control agent dispersion may be added during the aggregation step or may be added after the aggregation step.
[0050]
Here, as a method of aggregation, there are a method of performing aggregation by heating and a method of performing aggregation by adding an electrolyte, and these may be used in combination.
The aggregation temperature when performing aggregation by heating is usually in a temperature range of 5 ° C. to Tg (where Tg is the glass transition temperature of the polymer primary particles), and is in a range of Tg−10 ° C. to Tg−5 ° C. preferable. Within the above temperature range, the toner can be aggregated to a preferable toner particle size without using an electrolyte.
[0051]
In addition, in the case of performing aggregation by heating and performing the aging step subsequent to the aggregation step, the aggregation step and the aging step are performed continuously, and the boundary may be ambiguous. If there is a step in which the temperature is kept in a temperature range of 20 ° C. to Tg for at least 30 minutes, this is regarded as an aggregation step.
The aggregation temperature is preferably maintained at a predetermined temperature for at least 30 minutes to obtain toner particles having a desired particle size. The temperature may be raised at a constant rate up to a predetermined temperature, or may be raised stepwise. The holding time is preferably from 30 minutes to 8 hours, more preferably from 1 hour to less than 4 hours, in the range of Tg-20 ° C to Tg. By doing so, a toner having a small particle size and a sharp particle size distribution can be obtained.
[0052]
In the aggregation step of the present invention, the solid content concentration in the aggregation liquid is usually 10 to 40% by weight, preferably 10 to 20% by weight.
When the electrolyte is added to the mixed dispersion to perform aggregation, the electrolyte may be either an organic salt or an inorganic salt, but preferably a monovalent or divalent or higher polyvalent metal salt is 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.
[0053]
The amount of the electrolyte to be added varies depending on the type of the electrolyte, but is usually used in an amount of 0.05 to 25 parts by weight based on 100 parts by weight of the solid component of the mixed dispersion. Preferably it is 0.1 to 15 parts by weight, more preferably 0.1 to 10 parts by weight.
When the amount of the electrolyte added is significantly less than the above range, the agglutination reaction progresses slowly, and fine powder of 1 μm or less remains after the agglutination reaction, and the average particle size of the obtained agglomerated particles becomes 3 μm or less. Tend to occur. On the other hand, when the amount of the electrolyte added is significantly larger than the above range, the aggregation tends to be rapid and difficult to control, and coarse particles of 25 μm or more are mixed in the obtained aggregated particles, and the shape of the aggregates is irregular and unsharp. It tends to cause problems such as becoming a fixed form.
[0054]
In addition, in the case of performing aggregation by adding an electrolyte, the aggregation temperature is preferably in the range of 5 ° C. to Tg.
In the aggregating step, an ordinary stirring tank is used, and the shape is preferably a substantially cylindrical shape or a substantially spherical shape. When the reaction tank is substantially cylindrical, the shape of the bottom surface is not particularly limited, but an ordinary substantially arc-shaped one is preferably used.
[0055]
In order to improve the stirring efficiency, the volume of the mixed dispersion is preferably 2/3 or less of the volume of the reaction tank, more preferably 3/5 or less. On the other hand, if the volume of the mixed dispersion is extremely small compared to the volume of the reaction tank, bubbling is sharply increased, thickening is increased, coarse powder particles are easily generated, and there are cases where stirring is not performed depending on the shape of the stirring blade, and This ratio is preferably 1/10 or more, more preferably 1/5 or more, since the production efficiency also decreases.
[0056]
As the stirring blade used in the coagulation step, conventionally known and commercially available stirring blades having various shapes can be used.
Commercially available stirring blades include, for example, anchor blades, full zone blades (manufactured by Shinko Pantech Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), max blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), and Hi-F mixer blades (Soken) Stirring wings such as a double helical ribbon wing (manufactured by Shinko Pantech Co., Ltd.). Further, a baffle may be provided in the stirring tank.
[0057]
Usually, from among these stirring blades, those suitable for the viscosity and other physical properties of the reaction solution, or the reaction form, the shape and size of the reaction tank, and the like are selected and used. May be a double helical ribbon wing or an anchor wing, of which a double helical ribbon wing is more preferable.
A feature of the production method of the present invention is that the shape and particle size distribution of toner particles are easily controlled by additionally adding polymer primary particles in the aggregation step.
[0058]
Prior to the agglomeration step, the initial polymer primary particles, colorant primary particles, and, if necessary, an emulsion of charge control agent fine particles, wax fine particles, and other internal additives are mixed. With the initial amount of the polymer primary particles being 100 parts by weight, the amount of the colorant primary particles added is preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, and even more preferably 4 to 10 parts by weight. The added amount of the charge control agent fine particles is preferably 0 to 10 parts by weight. The addition amount of the wax fine particles is preferably 0 to 40 parts by weight, more preferably 0 to 20 parts by weight. The total solid concentration in the mixed solution is preferably 5 to 40% by weight, more preferably 10 to 20% by weight. If necessary, the amount of the mixed solution and the solid content concentration are adjusted by adding water.
[0059]
In the agglomeration step, the mixture is heated or an electrolyte is added, or the both are used in combination to start agglomeration, and then the polymer primary particles are additionally added.
The addition temperature of the additional polymer primary particles in the aggregation step is not particularly limited, but it is preferable to add the additional polymer primary particles at a temperature higher than the initial mixing temperature of the polymer primary particles and the colorant. The addition may be carried out while the mixture is kept at a constant temperature or while the mixture is being heated. From the viewpoint of controlling the shape and particle size distribution of the particle aggregate, it is preferable to add the mixture at a constant aggregation temperature.
[0060]
The method of adding the additional polymer primary particles in the aggregation step may be continuous addition or intermittent addition. In terms of the particle size distribution of the particle aggregates, it is preferable to add in two or more portions, and in that case, it is preferable to allow a stabilization time between each addition. It is also preferred that the addition of the additional polymer primary particles be performed continuously and so that the addition time accounts for one third or more of the total coagulation time.
[0061]
The electrolyte solution may be added simultaneously with the addition of the additional polymer primary particles in the aggregation step. Addition is more preferable in terms of controlling the shape and particle size distribution of the particle aggregate. Furthermore, it is preferable to additionally add the electrolyte solution after the addition of the additional polymer primary particles. Further, when the additional polymer primary particles are divided and added, it is preferable that the additional polymer primary particles and the additional electrolyte solution are alternately added.
[0062]
The additional polymer primary particles added in the aggregation step may be the same as the initial polymer primary particles. When the solid content weight of the initial polymer primary particles is A1, and the solid content weight of the additional polymer primary particles added in the aggregation step is A2, 1.0> A2 / (A1 + A2) ≧ 0.05, It is preferable that there is a relationship of 0.9 ≧ A2 / (A1 + A2) ≧ 0.05, and it is more preferable that there is a relationship of 0.8 ≧ A2 / (A1 + A2) ≧ 0.5. Is more preferred.
[0063]
In the aggregation step, primary colorant particles, charge control agent fine particles, wax fine particles, and other internal additives may be added simultaneously with the additional polymer primary particles. Regarding the addition method, they may be added separately, but they may be mixed in advance and a mixed solution may be added.
It is preferable that toner particles are formed by coating (adhering or fixing) resin fine particles as necessary on the surface of the particle aggregate after the above-mentioned aggregation treatment. When the above-mentioned charge control agent is added after the aggregation treatment, it is preferable to add the fine particles of the resin after adding the charge control agent to the dispersion containing the particle aggregate.
[0064]
Next, the aging step will be described.
In the aging step, toner particles are generated by causing fusion between particles in the particle aggregate in the dispersion containing the particle aggregate obtained in the above-described aggregation step.
That is, after the aggregation step, in order to increase the stability of the particle aggregate (toner particles) obtained in the aggregation step, the polymer is held at a temperature higher than the glass transition temperature (Tg) of the primary particles by 10 ° C. or more for a predetermined time. This causes fusion between the aggregated particles. The temperature of the aging step is usually (Tg + 80 ° C.) or lower and a temperature range not higher than the softening point of the polymer primary particles, but preferably in a temperature range of (Tg + 20 ° C.) to (Tg + 80 ° C.), and The temperature range is equal to or lower than the softening point of the primary polymer particles. This aging step is usually for 1 to 24 hours, preferably 2 to 10 hours.
[0065]
The aging step can be performed using a stirring tank similar to the stirring tank used in the aggregation step.
In order to prevent aggregation between the particle aggregates in the aging step, it is preferable to add a surfactant or raise the pH value of the aggregation liquid before starting the aging step. The aggregation step is completed by adding one or both of the surfactant and the pH adjuster. That is, since the surfactant and the pH adjusting agent serve as an agglutination reaction stopping agent, the temperature of the reaction solution is then raised to a predetermined temperature, and the aging process is started.
[0066]
By adding the aging step, the shape of the toner particles can be made nearly spherical, and the shape can be controlled. The ease with which the shape of the toner particles changes is determined by the glass transition temperature (Tg) and the softening temperature (Sp) of the particle aggregate composed of the primary polymer particles and other additives. The higher the glass transition temperature (Tg) or softening temperature (Sp) of the particle aggregate, the more difficult it is for the shape of the toner particles to change, and a longer aging time is required until the toner particles have a constant shape. If these temperatures are too high, shape control may not be possible in some cases. Further, with the aging for a long time, a coarse powder having a size of 15 μm or more which affects the properties of the toner may be generated.
[0067]
In the aging step, the shape of the toner particles can be more easily controlled by adjusting the solid content concentration of the dispersion by adding water or the like. The water to be mixed to adjust the solid concentration can be mixed at the end of the aggregation step, during the subsequent temperature increase, or at any time after reaching the predetermined ripening step temperature. However, the mixing time of water is preferably earlier, and it is preferable to mix the water at the end of the aggregation step, that is, at the same time as the addition of the surfactant and / or the pH adjuster that serves as the aggregation stopping agent. Further, it is preferable to add the solution before the temperature of the solution reaches (Tg + 10 ° C.).
[0068]
The toner particles obtained through each of the above steps are subjected to solid-liquid separation according to a known method, and the toner particles are collected, washed, and dried if necessary.
When the toner is used in a high-resolution printer or copier, it is preferable that the toner has a relatively small particle size and a sharp particle size distribution because the charge amount of each toner particle tends to be uniform.
[0069]
The volume average particle size of the toner obtained by the method of the present invention is usually 3 to 12 μm, preferably 4 to 10 μm, more preferably 5 to 9 μm, and still more preferably 6 to 8 μm. When the ratio (DV / DN) between the volume average particle size (DV) and the number average particle size (DN) is used as an index representing the particle size distribution, the value of DV / DN is preferably 1.20 or less. , 1.15 or less, more preferably 1.10 or less. The theoretical minimum value of DV / DN is 1, which means that all particles have the same diameter, which is advantageous for high-resolution image formation, but is practically 1 Obtaining a particle size distribution is extremely difficult. According to the present invention, a toner having a practically sufficient DV / DN of 1.10 or less can be produced.
[0070]
【Example】
Next, specific embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.
In the following examples, “parts” means “parts by weight”. The average particle size, weight average molecular weight, glass transition point (Tg), 50% circularity, and melting point of the wax were measured by the following methods.
[0071]
[Measuring method]
Volume average particle size, number average particle size, ratio of toner particles having a particle size of 5 μm or less and 15 μm or more: LA-500 manufactured by Horiba, Ultratrack analyzer manufactured by Nikkiso Co., Ltd., Coulter Counter Multisizer II manufactured by Coulter Co., Ltd. (Abbreviated as counter).
[0072]
Weight average molecular weight (Mw), molecular weight peak (Mp): measured by gel permeation chromatography (GPC) (apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10 μm manufactured by Polymer Laboratories, (Solvent: THF, sample concentration: 0.1 wt%, calibration curve: standard polystyrene)
Glass transition temperature (Tg): measured by DSC7 manufactured by PerkinElmer (heated from 30 ° C to 100 ° C in 7 minutes, rapidly cooled from 100 ° C to -20 ° C, and raised from -20 ° C to 100 ° C in 12 minutes) And the Tg value observed during the second heating was used).
[0073]
50% circularity: The toner was measured by a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation, and the circularity corresponding to the cumulative particle size value at 50% of the value obtained from the following equation was used.
[0074]
(Equation 1)
Circularity = Perimeter of a circle with the same area as the projected area of the particle / Perimeter of the projected image
Melting point of wax: Measurement was performed at a heating rate of 10 ° C./min using DSC-20 manufactured by Seiko Instruments Inc., and the temperature at the peak of the peak showing the maximum endotherm in the DSC curve was defined as the melting point of the wax.
[0075]
[Example 1]
(Wax dispersion-1)
68.33 parts of demineralized water, 30 parts of stearic acid ester of pentaerythritol (manufactured by NOF Corporation, Unistar H476) and 1.67 parts of neogen SC are mixed, emulsified by high-pressure shearing at 90 ° C., and the ester wax fine particles are dispersed. A liquid was obtained. The average particle size of the ester wax fine particles measured by LA-500 was 350 nm. The melting point of the wax was 63 ° C.
[0076]
(Polymer primary particle dispersion-1)
A reactor equipped with a stirrer (Max Blend Blade, manufactured by Sumitomo Heavy Industries, Ltd.), a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries (volume 2 m) ³ )), 44 parts of wax dispersion-1 and 404 parts of demineralized water were charged, and the temperature was raised to 90 ° C. under a nitrogen stream, 1.6 parts of an 8% aqueous hydrogen peroxide solution and 1.6 parts of an 8% ascorbic acid aqueous solution. Was added.
[0077]
Thereafter, a mixture of the following monomers and an aqueous solution of an emulsifier was added over 5 hours from the start of the polymerization, and an aqueous solution of the initiator was added over 6 hours from the start of the polymerization, and the mixture was further held for 30 minutes.
[0078]
[Table 1]
[Monomers]
76 parts of styrene (281 kg)
24 parts of butyl acrylate
Acrylic acid 3 parts
Bromotrichloromethane 0.2 parts
2-mercaptoethanol 0.004 parts
Hexanediol diacrylate 0.9 parts
[Emulsifier aqueous solution]
1 part of 15% Neogen SC aqueous solution
Demineralized water 25 parts
[Initiator aqueous solution]
9 parts of 8% hydrogen peroxide solution
9 parts of 8% ascorbic acid aqueous solution
After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the THF-soluble component of the polymer was 165,000, the average particle size measured by UPA was 195 nm, and the Tg was unclear.
[0079]
(Colorant fine particle dispersion liquid-1)
Pigment Blue 15: 3 aqueous dispersion (manufactured by Dainichi Seika, EP-700 BlueGA, pigment active ingredient 24%). The average particle size measured by UPA was 150 nm.
(Production of toner-1)
[0080]
[Table 2]
Polymer Primary Particle Dispersion-1 (for initial mixing) 22 parts (64 g: as solid content) Polymer Primary Particle Dispersion-1 (for additional addition) 78 parts (38 g: as solid content) (13 parts each time, total) (Added 6 times)
Colorant fine particle dispersion liquid-1 3.0 parts (as solid content)
Using each of the above components, a toner was manufactured by the following procedure.
[0081]
The polymer primary particle dispersion-1 (for initial mixing) and the colorant fine particle dispersion-1 were added to a reactor (2 liter, double helical blade with baffle) and mixed uniformly. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.2 part as a solid content). Thereafter, the temperature was raised to 45 ° C. over 30 minutes with stirring and maintained for 0.5 hour. Next, the polymer primary particle dispersion-1 (for additional addition) and the aluminum sulfate aqueous solution (0.04 part as a solid content) are added to the coagulation liquid in this order, and the operation of holding at 45 ° C. for 30 minutes is performed a total of six times. Repeated. Finally, an aqueous solution of neogen SC (4 parts as a solid content) was added, and the temperature was raised to 95 ° C. over 1 hour and maintained for 2 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner (toner-1).
[0082]
(Evaluation of toner-1)
The volume average particle size of Toner-1 measured by a Coulter counter is 5.7 μm, the ratio of the volume particle size of 4 μm or less is 1.19% by volume, and the ratio of 10 μm or more is 0.441% by volume. The ratio to the diameter was 1.05. The 50% circularity was 0.96.
[0083]
[Example-2]
In the agglomeration step, instead of adding the polymer primary particles-1 (for additional addition) and the aqueous solution of aluminum sulfate in six separate portions, the two are simultaneously and continuously added over 2 hours. Except for this, the same procedure was performed as in Example 1, and aging was performed at 95 ° C. for 2 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner (toner-2).
[0084]
To 100 parts of this toner, 0.6 part of silica subjected to hydrophobic surface treatment was mixed and stirred to obtain a developing toner (developing toner-2).
(Evaluation of toner-2)
The volume average particle diameter of Toner-2 measured by a Coulter counter is 6.1 μm, the ratio of the volume particle size of 4 μm or less is 0.618 vol%, the ratio of the toner particles of 10 μm or more is 0.678 vol%, the volume average particle size and the number average particle size. The diameter ratio was 1.06. The 50% circularity was 0.96.
[0085]
[Example-3]
A reactor equipped with a stirrer (Max Blend Wing, manufactured by Sumitomo Heavy Industries, Ltd.), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device (volume: 2 m) ³ ) Is charged with 5 parts of 15% neogen SC aqueous solution and 372 parts of demineralized water, heated to 90 ° C. under a nitrogen stream, and 1.6 parts of 8% hydrogen peroxide aqueous solution and 1.6 parts of 8% ascorbic acid aqueous solution are added. did.
[0086]
Thereafter, a mixture of the following monomers and an aqueous solution of an emulsifier was added over 5 hours from the start of the polymerization, and an aqueous solution of the initiator was added over 6 hours from the start of the polymerization, and further maintained for 30 minutes.
[0087]
[Table 3]
[Monomers]
88 parts of styrene (308 kg)
12 parts of butyl acrylate
Acrylic acid 2 parts
Bromotrichloromethane 0.5 parts
0.01 parts of 2-mercaptoethanol
Hexanediol diacrylate 0.4 parts
[Emulsifier aqueous solution]
2.5 parts of 15% Neogen SC aqueous solution
Demineralized water 24 parts
[Initiator aqueous solution]
9 parts of 8% hydrogen peroxide solution
9 parts of 8% ascorbic acid aqueous solution
After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the polymer soluble in THF of the polymer was 87,000, the average particle diameter measured by UPA was 123 nm, and the Tg was 85 ° C.
[0088]
(Production of toner-3)
[0089]
[Table 4]
Polymer Primary Particle Dispersion-1 (for initial mixing) 33 parts (60 g: as solids) Polymer Primary Particle Dispersion-1 (for additional addition) 66 parts (41 g: as solids) (22 parts each time, total) (Added 3 times)
4.6 parts of colorant fine particle dispersion liquid-1 (as solid content)
Resin fine particle dispersion-15 parts (10 g: as solid content)
Using each of the above components, a toner was manufactured by the following procedure.
[0090]
The polymer primary particle dispersion-1 (for initial mixing) and the colorant fine particle dispersion-1 were added to a reactor (2 liter, double helical blade with baffle) and mixed uniformly. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.4 part as a solid content). Thereafter, the temperature was raised to 50 ° C. over 30 minutes with stirring and maintained for 0.5 hour. Then, the operation of adding the polymer primary particle dispersion liquid-1 (for additional addition) to the aggregated liquid and maintaining the dispersion at 50 ° C. for 30 minutes was repeated a total of three times. Next, the resin fine particle dispersion liquid 1 and an aqueous solution of aluminum sulfate (0.04 part as a solid content) were added, and the mixture was kept at 52 ° C for 30 minutes. Finally, an aqueous solution of neogen SC (4 parts as a solid content) was added, and the temperature was raised to 95 ° C. over 1 hour and maintained for 2 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner (toner-3).
[0091]
(Evaluation of toner-3)
The volume average particle diameter of Toner-3 measured by a Coulter counter is 6.4 μm, the ratio of the volume particle diameter of 4 μm or less is 2.52% by volume, and the ratio of the toner particles of 10 μm or more is 0.156% by volume. The ratio with the diameter was 1.06. The 50% circularity was 0.95.
[0092]
[Comparative Example 1]
In a reactor (2 liter capacity, double helical blade with baffle), polymer primary particle dispersion-1 (all amounts for initial mixing and additional addition in Example 1) and colorant fine particle dispersion-1 (Example 1 and Example 2) The same was added and mixed uniformly. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.45 part as a solid content). Thereafter, the temperature was raised to 50 ° C. over 30 minutes with stirring and maintained for 2 hours. Finally, an aqueous solution of neogen SC (4 parts as a solid content) was added, and the temperature was raised to 95 ° C. over 45 minutes and maintained for 2 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner (toner-4).
[0093]
(Evaluation of Toner-4)
The volume average particle diameter of Toner-4 measured by a Coulter counter is 6.1 μm, the ratio of the volume particle diameter of 4 μm or less is 9.799 volume%, and the ratio of the toner particle of 4 μm or more is 0.180 volume%. The ratio to the diameter was 1.13. The 50% circularity was 0.94.
[0094]
Table 1 summarizes the change in particle size distribution and circularity of Examples 1 to 3 and Comparative Example 1.
[0095]
[Table 5]

[0096]
From the above results, according to the present invention, the shape and particle size distribution of the particle aggregate in the aggregation step can be controlled, the particle size distribution of the toner particles becomes sharp, and the target circularity can be obtained in a short time. It can be seen that the amount of coarse powder generated during aging is also small.
[0097]
【The invention's effect】
According to the present invention, the shape and particle size distribution of the particle aggregate can be controlled, the particle size distribution of the toner particles is sharpened, the target circularity can be achieved in a short time, and the amount of coarse powder generated during aging is also reduced. Few.
Further, the toner for developing an electrostatic charge image produced by the present invention has a small particle size and a sharp particle size distribution, and thus is suitable for high images and high image quality.

Claims (8)

In a toner production method including an aggregation step of aggregating particles in a dispersion liquid containing polymer primary particles and a colorant and a ripening step of causing fusion between the particles in the obtained particle aggregate, during the aggregation step A method for producing a toner for developing electrostatic images, characterized by additionally adding polymer primary particles. When the solid content weight of the primary polymer primary particles to be mixed with the colorant is A1, and the solid content weight of the additional polymer primary particles added in the aggregation step is A2, 1.0> A2 / (A1 + A2) ≧ 0 The method for producing a toner for developing an electrostatic image according to claim 1, wherein The method for producing a toner for developing an electrostatic image according to claim 1, wherein additional polymer primary particles are added at a temperature higher than the initial mixing temperature of the polymer primary particles and the colorant. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the additional polymer primary particles are added in two or more portions. The toner for developing an electrostatic image according to any one of claims 1 to 3, wherein the addition of the additional polymer primary particles is performed continuously and in such a manner that the addition time accounts for one third or more of the total aggregation time. Manufacturing method. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the polymer primary particles are obtained by an emulsion polymerization method. The method for producing a toner for developing an electrostatic charge image according to claim 6, wherein the polymer primary particles are obtained by an emulsion polymerization method using wax fine particles as seeds. The method for producing a toner for developing an electrostatic image according to any one of claims 1 to 7, wherein the primary particles of the polymer have a tetrahydrofuran-insoluble content of 15 to 80% by weight.