JP2016085292A - Manufacturing method of magenta toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a magenta toner that eliminates unevenness in grain size distribution of the magenta toner, and can provide a high-quality image without fogging and stains and having an appropriate image density.SOLUTION: In manufacturing a toner by aggregating a magenta pigment dispersion element and polymer primary particles, when adding a magenta pigment dispersion, the density increase rate of the magenta pigment in an aggregation reaction system is controlled to be within a specific range to sharpen a grain size distribution of the aggregates of the magenta pigment dispersion element and polymer primary particles. In manufacture of a toner having a core-shell structure, the manufacturing method is applied when forming a core layer.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a magenta toner for developing an electrostatic image used for an image forming method by electrophotography.

  In recent years, the use of image forming apparatuses such as electrophotographic copying machines has been expanded, and the market demand for image quality has been increasing. In particular, in office documents, in addition to the development of mapping technology and latent image forming technology for input, the types of character hieroglyphics are more abundant and finer at the time of output. Due to the spread and development, the reproducibility of a latent image with extremely high image quality that has few defects and unclearness in printed images is required. In particular, as a developer used in the case where the electrostatic latent image on the latent image carrier constituting the image forming apparatus is a line image of 100 μm or less (approximately 300 dpi or more), a conventional toner having a large particle diameter has fine line reproducibility. In general, the line image is not clear enough.

  In particular, in an image forming apparatus such as an electrophotographic printer using a digital image signal, a latent image is formed by gathering a certain number of dot units, and a solid portion, a halftone portion, and a light portion have a dot density. It is expressed by changing. However, if the toner base particles are not arranged faithfully in the dot unit, and there is a mismatch between the dot unit position and the actually placed toner position, it corresponds to the ratio of the black and white dot density of the digital latent image. There is a problem that the gradation of the toner image cannot be obtained. Furthermore, when the resolution is improved by reducing the dot size in order to improve the image quality, the reproducibility of the latent image formed from the minute dots becomes more difficult, and the sharpness with high resolution and poor gradation. There is a tendency to become an image lacking.

  In view of this, there has been proposed a device intended to improve the image quality by improving the reproducibility of minute dots by regulating the particle size distribution of the developer. For example, Patent Document 1 describes a toner in which particles of 5 μm or less are about 15 to 65% by number. Further, in Patent Document 2, in a toner particle having a 50% volume particle size of 2 to 8 μm, the number of toner particles having a particle size of “0.7 × 50% number particle size” or less may be 10 number% or less. Have been described.

  Furthermore, these toners have a relatively large proportion of fine powder and coarse powder remaining relative to toner having a predetermined particle size, and in a moment of friction, particularly as in the non-magnetic one-component development method. In a developing method that requires toner that is charged and has a fast charge rise, particles that are not sufficiently charged are generated. Therefore, the toner drops from the developing roller, the toner blows out, and the printing history of the first round after the second round of the developing roller. However, there are problems such as afterimage (ghost) in which the image density selectively rises and falls when picked up, drum cleaning failure, and print image contamination due to poor toner layer formation on the developing roller. No. 3 proposes a toner in which unevenness in the particle size distribution of the toner is improved and fine powder is reduced.

JP 2001-134005 A JP 2004-045948 A JP 2007-293322 A

However, when the above toner is used, the paper fog, the white background stain and the image density are improved for the cyan and black toners, but the fog and the white background stain are still suppressed for the magenta toner. At the same time, it was insufficient in terms of improving the image density.
The present invention has been made in view of the above problems, and provides a method for producing a magenta toner that improves unevenness in the particle size distribution of the magenta toner, and that provides a high-quality image having an appropriate image density without fogging and smudges. It is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has identified the magenta pigment concentration increase rate in the agglomeration reaction system when a toner is produced by aggregating the magenta pigment dispersion and the polymer primary particles. By controlling within this range, it has been found that the particle size distribution of the aggregate of the magenta pigment dispersion and the polymer primary particles can be sharpened, and by using this as a toner, the above problems can be solved.

The gist of the present invention is as follows.
[1] A method for producing a toner for developing an electrostatic charge image having an aggregating step of a magenta pigment dispersion and a polymer primary particle, wherein the magenta pigment concentration increasing rate in the aggregating step is 0.140% / hour or more. A method for producing a magenta toner for developing an electrostatic charge image, characterized by being 640% / hour or less.

  [2] A toner having a core-shell structure in which the electrostatic image developing toner has a core layer and a shell layer, wherein the aggregation step includes forming a shell layer on the core layer. [1] characterized in that it has a second agglomeration step to be formed, and the magenta pigment concentration increasing rate in the first agglomeration step is 0.140% / hour or more and 0.640% / hour or less. A method for producing the toner for developing an electrostatic image according to claim 1.

  According to the present invention, it is possible to obtain a toner capable of suppressing fogging and smearing of an image white background portion and simultaneously obtaining a high-quality image having an appropriate image density.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be arbitrarily modified without departing from the gist of the present invention.
Hereinafter, “magenta toner for developing an electrostatic image” may be simply abbreviated as “magenta toner” or “toner”.
Moreover, what is dispersed in each dispersion is referred to as a dispersion. For example, what is dispersed in a binder resin dispersion is referred to as a binder resin dispersion. The toner before the external additive is fixed or adhered is referred to as “toner mother particles”.

  The method for producing a magenta toner of the present invention is a method for producing toner by producing toner mother particles through a process of aggregating at least a magenta pigment dispersion and a polymer primary particle, and increasing the concentration of magenta pigment in the aggregation process. The speed is 0.140% / hour or more and 0.640% / hour or less.

<Magenta pigment dispersion>
The magenta pigment dispersion is dispersed in a solvent such as water and used as a magenta pigment dispersion in the aggregation step with the polymer primary particles.
The lower limit of the concentration increase rate of the magenta pigment in the aggregation step is 0.140% / hour or more, while the upper limit is 0.640% / hour or less, preferably 0.300% / hour or less.

The concentration increase rate of the magenta pigment in the aggregation process is controlled by adjusting the flow rate when a predetermined amount of the magenta pigment dispersion is added at a constant speed with a pump, thereby controlling the addition time of the entire magenta pigment dispersion to the aggregation process. .
The calculation method of the magenta pigment concentration increase rate in the aggregation step is as shown in the following formula (1).

Magenta pigment concentration increase rate = {addition amount of magenta pigment dispersion (kg) × pigment concentration (%)} ÷ {addition amount of polymer primary particle dispersion (kg) × solid content concentration (%)} ÷ magenta pigment Dispersion addition time (hr): Formula (1)
In the above formula (1), the amount of the polymer primary particle dispersion added is the polymer primary particles for forming the core layer in the case of producing a core-shell toner having a core layer and a shell layer, which will be described later. Refers to the amount of dispersion added.

  The magenta pigment used as the magenta pigment dispersion may be appropriately selected from those known to be usable in toners. Specifically, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 17.3, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, 269, C.I. I. Pigment Violet 19 or the like is preferably used.

The magenta pigment dispersion is prepared by a known method by adding 10 to 30 parts by weight of a magenta pigment and 1 to 15 parts by weight of an emulsifier with respect to 100 parts by weight of water.
The volume average particle diameter of the magenta pigment dispersion in the magenta pigment dispersion is monitored while preparing the dispersion, and finally the volume average particle diameter (Mv) of the magenta pigment dispersion in the magenta pigment dispersion is determined. The thickness is preferably 0.01 μm or more and 3 μm or less, and more preferably controlled in the range of 0.05 μm or more and 0.5 μm or less.

<Polymer primary particles>
The polymer primary particles are used in the aggregation step in a state of being dispersed in a solvent such as water.
There are several methods for preparing the polymer primary particle dispersion. For example, as in the case of producing a toner by the conventional emulsion polymerization aggregation method described in <Toner configuration> described later, polymer primary particles having a styrene or (meth) acrylic monomer as a constituent element The polymer primary particle dispersion can be obtained by emulsion polymerization of a styrene-based or (meth) acrylic monomer and, if necessary, a chain transfer agent using an emulsifier.

  Further, as another method, as in the case of producing a toner by a conventional emulsion aggregation method, a resin is obtained by a method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, and then an aqueous medium is used. The polymer primary particle dispersion is obtained by mixing, heating to a temperature higher than either the melting point of the resin or the glass transition temperature to lower the viscosity of the resin, and applying emulsification with shearing force. Examples of the emulsifier for applying a shearing force include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser.

<Configuration of toner>
The magenta toner produced according to the present invention is configured by appropriately selecting a binder resin, a colorant, a wax, an external additive, and the like.
The binder resin constituting the magenta toner may be appropriately selected from those known to be usable for toner. For example, styrene resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, epoxy resin, saturated or unsaturated polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, Ethylene-acrylate copolymer, xylene resin, polyvinyl butyral resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-anhydrous malein An acid copolymer etc. can be mentioned. These resins can be used alone or in combination.

  It is preferable to add a wax to the magenta toner to impart releasability. Any wax can be used as long as it has releasability, and is not particularly limited. Specifically, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymer polyethylene; paraffin wax; ester waxes having a long-chain aliphatic group such as behenyl behenate, montanate ester, stearyl stearate; water Plant waxes such as soy castor oil and carnauba wax; ketones having long chain alkyl groups such as distearyl ketone; silicones having alkyl groups; higher fatty acids such as stearic acid; long chain aliphatic alcohols such as eicosanol; glycerin and pentaerythritol Examples include carboxylic acid esters or partial esters of polyhydric alcohols obtained from polyhydric alcohols such as polyhydric alcohols and long chain fatty acids; higher fatty acid amides such as oleic acid amides and stearic acid amides; low molecular weight polyesters and the like.

  In order to improve the fixability among these waxes, the melting point of the wax is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Moreover, 100 degrees C or less is preferable, 90 degrees C or less is still more preferable, and 80 degrees C or less is especially preferable. If the melting point is too low, the wax tends to be exposed and sticky after fixing, and if the melting point is too high, the fixability at low temperatures is poor. Furthermore, as the wax compound species, ester waxes obtained from aliphatic carboxylic acids and mono- or polyhydric alcohols are preferred, and ester waxes having 20 to 100 carbon atoms are preferred.

  The above waxes may be used alone or in combination. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature for fixing the toner. The amount of the wax used is preferably 4 to 20 parts by weight, particularly preferably 6 to 18 parts by weight, and more preferably 8 to 15 parts by weight with respect to 100 parts by weight of the toner. In addition, when the volume median diameter (Dv50) of the toner is 7 μm or less, that is, when the toner has a small particle diameter, the exposure of the wax to the toner surface becomes extremely intense as the amount of the wax used increases. The storage stability of the toner is deteriorated. The toner of the present invention has a small particle size with a sharp particle size distribution that does not cause deterioration of the toner characteristics as compared with conventional toners even when the amount of wax used is large as in the above range. It is.

The magenta toner may be one in which a known external additive is blended on the surface of the toner base particles in order to control fluidity and developability. External additives include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc and hydrotalcite, titanium such as calcium titanate, strontium titanate and barium titanate. Examples thereof include acid metal salts, nitrides such as titanium nitride and silicon nitride, carbides such as titanium carbide and silicon carbide, and organic particles such as acrylic resins and melamine resins. Among these, silica, titania, and alumina are preferable, and those that have been surface-treated with, for example, a silane coupling agent or silicone oil are more preferable. The average primary particle diameter is preferably in the range of 1 to 500 nm, more preferably in the range of 5 to 100 nm. It is also preferable to use a combination of a small particle size and a large particle size in the particle size range. The total amount of the external additive is preferably in the range of 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner base particles.

As the binder resin constituting the polymer primary particles used in the emulsion polymerization aggregation method, one or more polymerizable monomers that can be polymerized by the emulsion polymerization method may be appropriately used.
At this time, each polymerizable monomer may be added separately, or a plurality of polymerizable monomers may be mixed in advance and added simultaneously. Furthermore, it is also possible to change the polymerizable monomer composition during the addition of the polymerizable monomer. Further, the polymerizable monomer may be added as it is, or may be added as an emulsion prepared by mixing with water or an emulsifier in advance.

  Among the polymerizable monomers, monomers having an acidic group, particularly (meth) acrylic acid are preferred. The ratio of the total amount of monomers having acidic groups in 100% by mass of all polymerizable monomers constituting the binder resin as the polymer primary particles is preferably 0.05% by mass or more, more preferably 0.3% by mass. Above, especially preferably 0.5% by mass or more, and more preferably 1% by mass or more. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

When it is in the above range, the dispersion stability of the obtained polymer primary particles is improved, and the particle shape and particle diameter can be easily adjusted in the aggregation step.
Other monomers include styrenes such as styrene, methyl styrene, chlorostyrene, p-tert-butyl styrene, pn-butyl styrene, pn-nonyl styrene, methyl acrylate, ethyl acrylate, propyl acrylate Acrylates such as n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid Methacrylic acid esters such as hydroxyethyl and ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutylacrylic Bromide, and amides of acrylic acid and the like. A polymerizable monomer may be used independently and may be used in combination of multiple.

  Moreover, among the above-described polymerizable monomers used in combination, as a preferred embodiment, an acidic monomer and other monomers may be used in combination. More preferably, (meth) acrylic acid is used as the acidic monomer, and a polymerizable monomer selected from styrenes and (meth) acrylic acid esters is used as the other monomer. It is preferable to use (meth) acrylic acid as the monomer, and use a combination of styrene and (meth) acrylic acid esters as the other monomer, and particularly preferably use (meth) acrylic acid as the acidic monomer and other monomers. As a combination of styrene and n-butyl acrylate.

Furthermore, it is also preferable to use a crosslinked resin as the binder resin constituting the polymer primary particles. In that case, a polyfunctional monomer having radical polymerizability is used as a crosslinking agent shared with the above polymerizable monomer. 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. Is mentioned. In addition, a polymerizable monomer having a reactive group in a pendant group such as glycidyl methacrylate, methylol acrylamide, acrolein or the like can be used as a crosslinking agent. Among them, radically polymerizable bifunctional monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable.

  These crosslinking agents such as polyfunctional monomers may be used alone or in combination. When a crosslinked resin is used as the binder resin constituting the polymer primary particles, the blending ratio of the crosslinking agent such as a polyfunctional monomer in the total polymerizable monomer constituting the resin is preferably 0.005% by mass or more, More preferably, it is 0.1 mass% or more, More preferably, it is 0.3 mass% or more, Preferably it is 5 mass% or less, More preferably, it is 3 mass% or less, More preferably, it is 1 mass% or less. desirable.

Known emulsifiers can be used for the emulsion polymerization, but one or more emulsifiers selected from cationic surfactants, anionic surfactants and nonionic surfactants are used in combination. be able to.
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.

Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate.
Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. Is mentioned.

The amount of the 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 completely saponified polyvinyl alcohol such as saponified polyvinyl alcohol, hydroxy One type or two or more types of cellulose derivatives such as ethyl cellulose can be used in combination as a protective colloid.
Examples of the polymerization initiator include hydrogen peroxide; persulfates such as potassium persulfate; organic peroxides such as benzoyl peroxide and lauroyl peroxide; 2,2′-azobisisobutyronitrile; Azo compounds such as 2′-azobis (2,4-dimethylvaleronitrile); redox initiators and the like are used. One or more of them are usually used in an amount of about 0.1 to 3 parts by weight with respect to 100 parts by weight of the polymerizable monomer. Among them, it is preferable that at least part or all of the initiator is hydrogen peroxide or organic peroxides.

Any of the polymerization initiators may be added to the polymerization system before, simultaneously with, or after the addition of the polymerizable monomer, and these addition methods may be combined as necessary.
In the emulsion polymerization, a known chain transfer agent can be used as necessary. Specific examples of such a chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, four Examples thereof include carbon chloride and trichlorobromomethane. The chain transfer agent may be used alone or in combination of two or more, and is usually used in a range of 5% by mass or less based on the total polymerizable monomer. Moreover, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, etc. can be further mix | blended with a reaction system suitably.

In the emulsion polymerization, the polymerizable monomer is polymerized in the presence of a polymerization initiator, and the polymerization temperature is usually 50 to 120 ° C, preferably 60 to 100 ° C, and more preferably 70 to 90 ° C.
The volume average diameter (Mv) of the polymer primary particles obtained by emulsion polymerization is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and usually 3 μm or less, preferably 2 μm or less. More preferably, the thickness is 1 μm or less. When the particle size is less than the above range, it may be difficult to control the aggregation rate. When the particle size exceeds the above range, the particle size of the toner obtained by aggregation tends to be large, and a toner having a target particle size can be obtained. It can be difficult.

In the present invention, a dispersion liquid containing polymer primary particles obtained by emulsion polymerization is added with a dispersion liquid such as a magenta pigment, a charge control agent, and wax, and the primary particles in the dispersion liquid are aggregated to form core particles. The toner base particles are preferably obtained by washing and drying the particles obtained by fixing or adhering resin fine particles or the like and then fusing them.
The resin fine particles may be produced by the same method as the above polymer primary particles, and the structure thereof is not particularly limited, but the polar monomer occupies in 100% by mass of the total polymerizable monomer constituting the binder resin as the resin fine particles. The ratio of the total amount is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more. The upper limit is preferably 3% by mass or less, more preferably 1.5% by mass or less. When it is in the above range, the dispersion stability of the obtained resin fine particles is improved, and it becomes easy to adjust the particle shape and particle diameter in the aggregation process.

  Further, the proportion of the total amount of polar monomers in 100% by mass of the total polymerizable monomer constituting the binder resin as the resin fine particles is in 100% by mass of the total polymerizable monomer constituting the binder resin as the polymer primary particle. It is preferable that the ratio is smaller than the ratio of the total amount of polar monomers in view of easy adjustment of the particle shape and particle diameter in the aggregation process, generation of fine powder can be suppressed, and excellent charging characteristics.

In addition, the Tg of the binder resin as the resin fine particles is preferably higher than the Tg of the binder resin as the polymer primary particles from the viewpoint of storage stability and the like.
The colorant is not particularly limited as long as it is a commonly used colorant. For example, the pigment mentioned above is mentioned. The content of the colorant may be an amount sufficient for the obtained toner to form a visible image by development. For example, the content is preferably in the range of 1 to 25 parts by weight in the toner, more preferably 1 to 15 parts by weight, particularly preferably 3 to 12 parts by weight.

  As a blending method of the magenta pigment in the emulsion polymerization aggregation method, after preparing the polymer primary particle dispersion, the magenta pigment dispersion is added at a constant speed with a pump. At that time, the flow rate of the pump is adjusted to control the addition time of the magenta pigment dispersion. Thereafter, this is aggregated to form particle aggregates. The magenta pigment is preferably used in the state of being emulsified in water in the presence of an emulsifier by mechanical means such as a sand mill or a bead mill. The blend of the colorant dispersion at the time of emulsion aggregation is calculated and used so as to be 2 to 10% by mass in the finished toner base particles after aggregation.

The wax may be contained in the polymer primary particles or in the resin fine particles. However, in general, as the amount of wax used increases, aggregation control tends to deteriorate and the particle size distribution tends to become broader.
Therefore, as a method of blending the wax in the emulsion polymerization aggregation method, a wax dispersion that has been previously emulsified and dispersed in water at a volume average diameter (Mv) of 0.01 to 2.0 μm, more preferably 0.01 to 0.5 μm, is emulsified. It is preferable to add at the time of superposition | polymerization or to add at the aggregation process. In order to disperse the wax with a suitable dispersed particle diameter in the toner, it is preferable to add the wax as a seed during emulsion polymerization. By adding as a seed, polymer primary particles in which wax is encapsulated can be obtained, so that a large amount of wax does not exist on the toner surface, and deterioration of chargeability and heat resistance of the toner can be suppressed. The wax content in the polymer primary particles is preferably 4 to 30% by mass, more preferably 5 to 20% by mass, and particularly preferably 7 to 15% by mass.

The magenta toner may be blended with a charge control agent to impart charge amount and charge stability. Conventionally known compounds are used as the charge control agent. Examples thereof include hydroxycarboxylic acid metal complexes, azo compound metal complexes, naphthol compounds, naphthol compound metal compounds, nigrosine dyes, quaternary ammonium salts, and mixtures thereof.
The blending amount of the charge control agent is preferably in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin.

  When a charge control agent is contained in the toner in the emulsion polymerization aggregation method, the charge control agent is blended with a polymerizable monomer or the like at the time of emulsion polymerization, or is blended in the aggregation process with the polymer primary particles and the colorant. The blended primary particles, the colorant, and the like can be blended by a method such as blending after agglomeration to obtain an appropriate particle size as a toner. Of these, the charge control agent is preferably emulsified and dispersed in water using an emulsifier, and used as an emulsified dispersion having a volume average diameter (Mv) of 0.01 μm to 3 μm. The formulation of the charge control agent dispersion at the time of emulsion aggregation is calculated and used so as to be 0.1 to 5% by mass in the finished toner base particles after aggregation.

The volume average diameter (Mv) of the polymer primary particles, the colorant dispersed particles, the wax dispersed particles, the charge control agent dispersed particles and the like in the dispersion is measured using a nanotrack by the method described in the Examples, It is defined as the measured value.
In the flocculation step in the emulsion polymerization flocculation method, the blended components such as the polymer primary particles, the colorant particles, and, if necessary, the charge control agent and the wax are mixed simultaneously or sequentially. A dispersion, that is, a polymer primary particle dispersion, a colorant particle dispersion, a charge control agent dispersion, and a wax fine particle dispersion are prepared.

  The aggregating treatment usually includes a heating method, a method of adding an electrolyte, a method of combining these, and the like in a stirring tank. When primary particles are agglomerated under stirring to obtain particle agglomerates that are approximately the size of the toner, the particle size of the particle agglomerates is controlled from the balance between the agglomeration force between the particles and the shearing force due to agitation. However, the cohesive force can be increased by heating or adding an electrolyte.

As an electrolyte in the case of performing aggregation by adding an electrolyte, any of an organic salt and an inorganic salt may be used. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO _{4 are used. , 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 the electrolyte blended varies depending on the type of electrolyte, target particle size, and the like, but is usually 0.05 to 25 parts by mass, preferably 0.1 to 15 parts per 100 parts by mass of the solid component of the mixed dispersion. Part by mass, more preferably 0.1 to 10 parts by mass. When the blending amount is less than the above range, the progress of the agglutination reaction is slow, and fine powders of 1 μm or less remain after the agglomeration reaction, the average particle diameter of the obtained particle aggregate does not reach the target particle diameter, etc. There are cases. In addition, when the upper limit of the above range is exceeded, rapid agglomeration tends to occur and it becomes difficult to control the particle size, and the resulting agglomerated particles may cause problems such as inclusion of coarse powder or irregular shapes. .

Here, as a method of controlling the particle size within a specific range, a method of suppressing the blending amount of the electrolyte may be employed. In general, if the amount of the electrolyte is suppressed, the particle growth rate is slow, which is not industrially preferable in terms of production efficiency. However, contrary to the industrial point of view, it is possible to control the particle size within a specific range by intentionally suppressing the amount of electrolyte.
Moreover, 20-70 degreeC is preferable and, as for the aggregation temperature in the case of performing aggregation by adding electrolyte, 30-60 degreeC is more preferable. Here, controlling the temperature before the aggregation step is one of the methods for controlling the particle size within a specific range. Some colorants added to the aggregating step also have the properties of the electrolyte, and may aggregate without adding the electrolyte. Therefore, the aggregation can be prevented by cooling the temperature of the polymer primary particle dispersion in advance when mixing the colorant dispersion. This aggregation easily generates fine powder and causes unevenness in the particle size distribution. In the present invention, the polymer primary particles are preferably cooled in advance in a range of preferably 0 to 15 ° C, more preferably 0 to 12 ° C, and still more preferably 2 to 10 ° C.

The aggregation temperature in the case of performing aggregation only by heating without using an electrolyte is usually in the temperature range of (Tg-20 ° C) to Tg with respect to the glass transition temperature Tg of the polymer primary particles, and (Tg-10 ° C). ) To (Tg-5 ° C.).
The time required for agglomeration is optimized depending on the shape of the apparatus and the processing scale, but in order to reach the target particle size, the toner base particles are usually held at a temperature within the above range for at least 30 minutes. It is desirable. The temperature rise until reaching the predetermined temperature may be raised at a constant rate, or may be raised stepwise.

  In the present invention, a primary polymer particle dispersion can be added (attached or fixed) to the particle aggregate after the above-described aggregation treatment as necessary to form core-shell toner base particles. The production method of the present invention is preferably applied to the case where the core layer is formed when forming the core-shell toner base particles having the core layer and the shell layer. Specifically, the aggregation process includes a first aggregation process for forming the core layer and a second aggregation process for forming a shell layer on the core layer, and the concentration of the magenta pigment is increased in the first aggregation process. The speed is preferably 0.140% / hour or more and 0.640% / hour or less.

When the charge control agent is added after the aggregation treatment, it is preferable to add the resin fine particles after adding the charge control agent to the dispersion containing the particle aggregate.
In the emulsion polymerization aggregation method, in order to increase the stability of the particle aggregate obtained by aggregation, an emulsifier and a pH adjuster are added as a dispersion stabilizer to reduce the cohesive force between the particles, thereby growing the toner base particles. It is preferable to add an aging step for causing fusion between the agglomerated particles after stopping.

Here, the toner of the present invention preferably has a sharp particle size distribution. As a method for controlling the particle size within a specific range, the stirring rotational speed is reduced before the step of adding an emulsifier and a pH adjuster, that is, And a method of reducing the shearing force by stirring.
In the ripening step, the viscosity of the binder resin is lowered by heating to be circularized, but if heated as it is, the growth of the toner base particle size does not stop, so for the purpose of stopping the particle size growth by heating, usually as a dispersion stabilizer It is possible to apply a shearing force by adding an emulsifier or a pH adjuster or increasing the number of stirring revolutions.

Even before the step of adding the dispersion stabilizer, a toner having a specific particle size distribution can be obtained even if the stirring rotational speed is lowered to reduce the shearing force to the aggregated particles. However, in consideration of the point that the amount of the dispersion stabilizer can be adjusted, it is preferable to perform it before the step of adding the dispersion stabilizer.
The temperature of the aging step is preferably not less than Tg of the binder resin constituting the primary particles, more preferably not less than 5 ° C higher than the Tg, and preferably not more than 80 ° C higher than the Tg, more preferably The temperature is 50 ° C. or higher than Tg. The time required for the aging step varies depending on the shape of the target toner, but after reaching the glass transition temperature of the polymer constituting the primary particles, usually 0.1 to 10 hours, preferably 1 to 6 hours. It is desirable to hold.

In the emulsion polymerization aggregation method, it is preferable to add an emulsifier or raise the pH value of the aggregation liquid after the aggregation process, preferably before or during the aging process. As the emulsifier used here, one or more kinds of emulsifiers that can be used when producing the polymer primary particles can be selected and used, and particularly used when the polymer primary particles are produced. It is preferable to use the same emulsifier.

  The blending amount in the case of blending the emulsifier is not limited, but is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, further preferably 3 parts by weight or more with respect to 100 parts by weight of the solid component of the mixed dispersion. Moreover, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less. After the aggregation process, before the completion of the ripening process, by adding an emulsifier or by increasing the pH value of the flocculation liquid, aggregation of the particle aggregates aggregated in the aggregation process can be suppressed. The generation of coarse particles in the toner can be suppressed.

  By such heat treatment, the primary particles in the aggregate are fused and integrated, and the shape of the toner base particles as the aggregate also becomes nearly spherical. 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 base 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 particle aggregate obtained through each of the above steps is subjected to solid / liquid separation according to a known method, the particle aggregate is recovered, then washed as necessary, and then dried. Toner mother particles can be obtained.
Further, an outer layer mainly composed of a polymer is further formed on the surface of the particles obtained by the emulsion polymerization aggregation method by, for example, a spray drying method, an in-situ method, or a submerged particle coating method. It is also possible to obtain encapsulated toner base particles by forming them with a thickness of preferably 0.01 to 0.5 μm.

  In the emulsion polymerization aggregation method toner, the average circularity measured using a flow type particle image analyzer FPIA-3000 (manufactured by Malvern) is preferably 0.90 or more, more preferably 0.92 or more, and still more preferably. Is 0.95 or more. The closer to a sphere, the less the localization of the charge amount in the particles and the developability tends to be uniform, but since it is difficult to produce a perfect spherical toner, the average circularity is Preferably it is 0.995 or less, More preferably, it is 0.990 or less.

  In addition, at least one of the peak molecular weights in gel permeation chromatography (hereinafter sometimes abbreviated as “GPC”) of the tetrahydrofuran (THF) soluble content of the toner is preferably 10,000 or more, more preferably 1. 50,000 or more, more preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, still more preferably 50,000 or less. When the peak molecular weight is lower than the above range, the mechanical durability in the non-magnetic one-component development method may be deteriorated. When the peak molecular weight is higher than the above range, the low temperature fixability and the fixing strength are deteriorated. There is a case.

The THF insoluble content of the toner is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 20% by mass or less, more preferably, when measured by a mass method by celite filtration. It is good that it is 10 mass% or less. If it is not within the above range, it may be difficult to achieve both mechanical durability and low-temperature fixability.
The chargeability of the emulsion polymerization aggregation method toner may be positively charged or negatively charged. Control of the chargeability of the toner may include the selection and content of a charge control agent, the selection and blending amount of an external additive, etc. Can be adjusted by.

  The toner base particles thus obtained may be made into a toner by mixing known external additives on the surface of the toner base particles in order to control fluidity and developability. External additives include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc and hydrotalcite, titanium such as calcium titanate, strontium titanate and barium titanate. Examples thereof include acid metal salts, nitrides such as titanium nitride and silicon nitride, carbides such as titanium carbide and silicon carbide, and organic particles such as acrylic resins and melamine resins. Among these, silica, titania, and alumina are preferable, and those that have been surface-treated with, for example, a silane coupling agent or silicone oil are more preferable.

The average primary particle diameter is preferably in the range of 1 to 500 nm, more preferably in the range of 5 to 100 nm. It is also preferable to use a combination of a small particle size and a large particle size in the particle size range. The total amount of the external additive is preferably in the range of 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner base particles.
The toner for developing an electrostatic image of the present invention is a magnetic two-component developer in which a carrier for conveying the toner to the electrostatic latent image portion by a magnetic force coexists, or a magnetic toner containing a magnetic powder in the toner. It may be used for either a component developer or a non-magnetic one-component developer that does not use magnetic powder as a developer. In order to express the effect of the present invention remarkably, it is particularly preferable to use as a developer for a non-magnetic one-component development system.

  When used as the magnetic two-component developer, the carrier that is mixed with the toner to form the developer is a known magnetic substance such as an iron powder type, ferrite type, or magnetite type carrier, or a resin coating on the surface thereof. 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 mass with respect to 1 part by mass of the toner.

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, “part” means “part by mass”.
Each particle diameter, circularity, electrical conductivity and the like were measured as follows.

<Volume average diameter measurement (MV)>
The volume average diameter (MV) of particles with a volume average diameter (MV) of less than 1 micron is from Nikkiso Co., Ltd. Model Microtrac Nanotrac150 (hereinafter abbreviated as Nanotrack) and analysis software Microtrac Particle Analyzer Ver10.1.2-019EE The method described in the instruction manual using the ion-exchanged water having an electric conductivity of 0.5 μS / cm as the solvent, the solvent refractive index: 1.333, the measurement time: 100 seconds, and the number of measurements: once. Measured with Other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: true sphere, density: 1.04.

<Volume median diameter of wax dispersion>
In order to determine the end point at the time of wax emulsification, Partica LA-950V2 (hereinafter abbreviated as LA950) manufactured by HORIBA, Ltd., which is a laser diffraction scattering type particle size distribution measuring apparatus capable of high-speed measurement, was used. The end point particle size at that time was set as the median diameter. The solvent used was ion exchange water having an electric conductivity of 0.5 μS / cm, and the measurement was performed by adjusting the sample amount in a concentration range of solvent refractive index: 1.333 and visible light transmittance of 70% to 90%.

<Measurement method and definition of median diameter (volume: Dv50 and number: Dn50)>
Regarding the measurement of the particle diameter during the production process of the toner base particles, the filtrate obtained by filtering the agglomerated slurry with a 63 μm mesh was used as the “slurry liquid”.
The median diameter (Dv50 and Dn50) of the particles is Multisizer III manufactured by Beckman Coulter.
(Aperture diameter 100 μm) (hereinafter abbreviated as “Multisizer”), Isoton II made by the same company is used as a dispersion medium, and the above-mentioned “toner dispersion liquid” or “slurry liquid” is used with a dispersoid concentration of 0.03. Dilute to mass% and use a Multisizer III analysis software with a KD value of 118. Measured as 5. The measurement particle size range is from 2.00 to 64.00 μm,
This range is discretized into 256 divisions at equal intervals on a logarithmic scale, and the volume median diameter (Dv50) and the statistical value based on the number are calculated based on the statistical values based on the volume. The number median diameter (Dn50) was calculated as above.

<Measuring method and definition of average circularity>
The “average circularity” in the present invention is measured as follows and is defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) in a range of 5720 to 7140 particles / μL, and a flow type particle image analyzer (manufactured by Sysmex Corporation, FPIA3000) is used. Measured under the following apparatus conditions, the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.

・ Mode: HPF
-HPF analysis amount: 0.35 μL
-Number of HPF detected: 8,000-10,000 The following are measured by the above device and automatically calculated and displayed in the above device, but "roundness" is defined by the following formula The
[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
Then, the number of HPF detected is 8,000 to 10,000, and the arithmetic average (arithmetic mean) of the circularity of each particle is displayed on the apparatus as “average circularity”.

<Electrical conductivity measurement>
The electrical conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

<Method for measuring weight average molecular weight and molecular weight peak>
Measured by gel permeation chromatography (GPC) (apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10μ manufactured by Polymer Laboratory, solvent: tetrahydrofuran, sample concentration: 0.1 wt% Calibration curve: standard polystyrene).

<Measurement method of solid content>
Solid content concentration measuring instrument I N F R A R E D M O IST manufactured by Kett Science Laboratory
1. Sample containing solid content using UREDET ER MIN AT ION BA LAL AN C E Model FD-1100 0 g was precisely weighed on a balance, and the solid content concentration was measured under the conditions of a heater temperature of 120 ° C. and a heating time of 90 minutes.

<Fog>
The toner for development was put in a cartridge of a color page printer ML9600PS (Oki Data Co., Ltd.), 10 solid images were printed, and then left in an environment of 30 ° C. and 80% for 10 hours.
After printing the check image, the toner remaining on the photoconductor was collected with a tape and pasted on a white paper. An unused tape was pasted on a white paper, and a color difference ΔE between the unused tape and the test tape was calculated. For the measurement of ΔE, a Hunter whiteness meter ZE-2000 (manufactured by NIPPON DENSHOKU) was used, and ΔE was calculated from the L * a * b * color system. The fog was determined according to the following criteria.

The evaluation results of Examples 1 to 4, Comparative Examples 1 to 3 and Reference Examples 1 to 4 are shown in Table-1.
Magenta toner and cyan toner ○: ΔE is less than 1.5 ×: ΔE is 1.5 or more Black toner ○: ΔE is less than 2.5 ×: ΔE is 2.5 or more

<Dirt>
The toner for development was put in the cartridge of the color page printer ML9600PS (manufactured by Oki Data Co., Ltd.), and 50 sheets of 1% printing rate charts were continuously printed.

The smear of the image after printing 50 sheets was visually observed and judged according to the following criteria.
The evaluation results of Examples 1 to 4, Comparative Examples 1 to 3 and Reference Examples 1 to 4 are shown in Table-1.
◎: No dirt at all ○: Slightly dirty but usable level △: Partly slightly dirty *: Partly or entirely dirty.

≪Example of toner production≫
<Preparation of wax dispersion A1>
Wax 1 (HiMic-1090 (manufactured by Nippon Seiwa Co., Ltd.)) 29.7 parts, decaglycerin decabehenate (acid value 3.2, hydroxyl value 27) 0.3 part, 20% aqueous solution of sodium dodecylbenzenesulfonate (No. Ichi Kogyo Seiyaku Co., Ltd., Neogen S20D (hereinafter abbreviated as 20% DBS aqueous solution) 2.8 parts aqueous solution, 67.2 parts demineralized water added and heated to 100 ° C., homogenizer with pressure circulation line LAB60-10TBS type) was used for primary circulation emulsification under a pressure of 10 MPa. The particle diameter is measured every few minutes with LA950, and when the median diameter is reduced to around 500 nm, the pressure condition is further increased to 25 MPa, followed by secondary circulation emulsification. A wax dispersion A1 was produced by dispersing until the median diameter was 230 nm or less.
The volume median diameter of the wax dispersion was 215 nm.

<Preparation of wax dispersion A2>
Wax 2 (HNP-9 (Nihon Seiwa Co., Ltd.)) 27.0 parts, 3.0 parts of stearyl acrylate, 20% sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D, hereinafter 20% DBS aqueous solution) Abbreviated) 1.9 parts of aqueous solution and 68.1 parts of demineralized water, heated to 100 ° C., and using a homogenizer with a pressure circulation line (manufactured by Gorin, LAB 60-10TBS type) under a pressure of 10 MPa. Primary circulation emulsification was performed. The particle diameter is measured every few minutes with LA950, and when the median diameter is reduced to around 500 nm, the pressure condition is further increased to 25 MPa, followed by secondary circulation emulsification. A wax dispersion A1 was produced by dispersing until the median diameter was 230 nm or less. The volume median diameter of the wax dispersion was 219 nm.

<Preparation of polymer primary particle dispersion B1>
A reactor equipped with a stirring device (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device was charged with 40.9 parts of the wax dispersion A1 and 260 parts of demineralized water while stirring. The temperature was raised to 90 ° C. under a nitrogen stream.
Thereafter, the mixture of the following “polymerizable monomers and the like” and “emulsifier aqueous solution” was added to the solution over 5 hours while continuing to stir the liquid. The time at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “additional start” The agent aqueous solution ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 75.9 parts Butyl acrylate 24.1 parts Acrylic acid 1.2 parts Hexanediol diacrylate 0.6 parts Trichlorobromomethane 1.0 part
[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 66.9 parts
[Initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 15.5 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.5 parts
[Additional initiator aqueous solution]
8 mass% L (+)-ascorbic acid aqueous solution 14.2 parts It cooled after completion | finish of polymerization reaction, and milky-white polymer primary particle dispersion liquid B1 was obtained. The volume average diameter (Mv) measured using Nanotrac was 275 nm, and the solid content concentration was 23.0% by mass.

<Preparation of polymer primary particle dispersion B2>
A reactor equipped with a stirring device (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device was charged with 35.5 parts of the wax dispersion A2 and 282 parts of demineralized water while stirring. The temperature was raised to 90 ° C. under a nitrogen stream.
Thereafter, the mixture of the following “polymerizable monomers and the like” and “emulsifier aqueous solution” was added to the solution over 5 hours while continuing to stir the liquid. The time at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “additional start” The agent aqueous solution ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 76.8 parts Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Hexanediol diacrylate 0.7 parts Trichlorobromomethane 1.0 part
[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 67.1 parts
[Initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 15.5 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.5 parts
[Additional initiator aqueous solution]
8 mass% L (+)-ascorbic acid aqueous solution 14.2 parts It cooled after completion | finish of polymerization reaction, and milky white polymer primary particle dispersion B2 was obtained. The volume average diameter (Mv) measured using Nanotrac was 260 nm, and the solid content concentration was 20.4% by mass.

<Preparation of polymer primary particle dispersion B3>
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device was charged with 1.7 parts of 20% DBS aqueous solution and 285 parts of demineralized water, and nitrogen was stirred. The temperature was raised to 90 ° C. under an air stream.
Thereafter, the mixture of the following “polymerizable monomers and the like” and “emulsifier aqueous solution” was added to the solution over 5 hours while continuing to stir the liquid. The time at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 5 hours from 0 minutes after the start of polymerization. Further, 5 hours after the start of polymerization, the following “additional initiator aqueous solution” was added. Was added over a period of 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 100 parts Acrylic acid 0.5 parts Trichlorobromomethane 0.75 parts
[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 66.0 parts
[Initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 15.7 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.7 parts
[Additional initiator aqueous solution]
8 mass% L (+)-ascorbic acid aqueous solution 14.2 parts It cooled after completion | finish of polymerization reaction, and milky-white polymer primary particle dispersion B3 was obtained. The volume average diameter (Mv) measured using Nanotrac was 257 nm, and the solid content concentration was 20.0% by mass.

[Example 1]
<Manufacture of developing toner Ma1>
Polymer primary particle dispersion B1 (for core) 80 parts as solid content Polymer primary particle dispersion B2 (for shell) 20 parts as solid content
Polymer primary particle dispersion B3 (for shell) 3 parts as solid matter Magenta pigment dispersion (EP1210 manufactured by Dainichi Seika Co., Ltd. 20.0% pigment concentration) 9 parts as colorant solid content 20% DBS aqueous solution 0. 05 parts Toner base particles were produced by the following procedure using the above components.

Polymer primary particle dispersion B1 (core) in a mixer (volume 12 liters, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device For use) 4016.9 g and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 12 ° C. for 5 minutes. Subsequently, while continuing stirring at an internal temperature of 12 ° C., 0.52 part of 5% aqueous solution of ferrous sulfate as FeSO ₄ .7H ₂ O was added over 5 minutes, and then the magenta pigment dispersion 4
51.9 g was added at a constant rate with a pump. At that time, the flow rate of the pump was adjusted, and the entire magenta pigment dispersion was added over 10 minutes. Thereafter, the mixture was uniformly mixed at an internal temperature of 12 ° C., and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content relative to the resin solid content was 0.20 part). Thereafter, the temperature was raised to 54 ° C. over 75 minutes, and further raised to 56 ° C. over 170 minutes. Here, when the volume median diameter (Dv50) and the particle size distribution (Dv / Dn) were measured using a multisizer, they were 5.7 μm and 1.094. The rate of increase in the pigment concentration was 0.587 as calculated using Equation (1). Thereafter, the polymer primary particle dispersion B2 (for shell) is added over 20 minutes and held as it is for 60 minutes, and then the polymer primary particle dispersion B3 (for shell) is added over 3 minutes and left as it is. Then, 20% DBS aqueous solution (6 parts as solid content) was added over 10 minutes, then heated to 95 ° C. over 30 minutes, and the average circularity was 0.972 over 120 minutes. Stirring was continued until. Then, it cooled to 30 degreeC over 30 minutes, and obtained the slurry. At this time, the particle had a Dv50 of 7.03 μm and an average circularity of 0.972.

  This slurry was subjected to suction filtration with an aspirator using filter paper of type 5 C (No. 5C manufactured by Toyo Roshi Kaisha, Ltd.). The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), added with 8 kg of ion-exchanged water having an electric conductivity of 1 μS / cm, and uniformly dispersed by stirring at 50 rpm. Stirred for 30 minutes. Then, suction filtration is performed with an aspirator again using filter paper of 5 types C (Toyo Filter Paper Co., Ltd. No5C), and the solid matter remaining on the filter paper is again equipped with a stirrer (propeller blade) and has an electric conductivity of 1 μS / cm. It was transferred to a 10 L container with 8 kg of ion-exchanged water, and evenly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm.

The obtained cake was spread on a stainless steel pad so as to have a height of 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain toner mother particles.
Silica having a volume average primary particle size of 0.10 μm, in which 100 parts (500 g) of the obtained toner base particles are put into a 9 L Henschel mixer manufactured by Mitsui Mining Co., Ltd., and then hydrophobized with hexamethyldisilazane. By adding 2.0 parts of fine particles and 0.6 part of silica fine particles having a volume average primary particle size of 0.012 μm hydrophobized with silicone oil, mixing at 3500 rpm for 15 minutes, and sieving with 200 mesh A developing toner Ma1 was obtained.

[Example 2]
<Manufacture of developing toner Ma2>
A developing toner Ma2 was obtained in the same manner as the developing toner Ma1, except that the magenta pigment dispersion was added over 20 minutes.
[Example 3]
<Manufacture of developing toner Ma3>
A developing toner Ma3 was obtained in the same manner as the developing toner Ma1, except that the magenta pigment dispersion was added over 40 minutes.

[Comparative Example 1]
<Manufacture of developing toner Ma4>
A developing toner Ma4 was obtained in the same manner as the developing toner Ma1, except that the magenta pigment dispersion was added over 6 minutes.
[Comparative Example 2]
<Manufacture of developing toner Ma5>
A developing toner Ma5 was obtained in the same manner as the developing toner Ma1, except that the magenta pigment dispersion was added over 45 minutes.

[Example 4]
<Manufacture of developing toner Ma6>
Polymer primary particle dispersion B1 (core) in a mixer (volume 11 sqm, inner diameter 2100 mm, height 3700 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrating device, and raw material / auxiliary charging device A developing toner Ma6 was obtained in the same manner as the developing toner Ma1, except that 6110 kg and a 20% DBS aqueous solution were charged and 740 kg of a magenta pigment dispersion was added over 10 minutes.

[Comparative Example 3]
<Manufacture of developing toner Ma7>
A developing toner Ma7 was obtained in the same manner as the developing toner Ma6 except that the magenta pigment dispersion was added over 46 minutes.
[Reference Example 1]
<Manufacture of developing toner Cy1>
Polymer primary particle dispersion B1 (for core) 80 parts as solid content Polymer primary particle dispersion B2 (for shell) 20 parts as solid content
Cyan pigment dispersion (EP750, manufactured by Dainichi Seika Co., Ltd. 24.0% pigment concentration) 4.4 parts as colorant solids 20% DBS aqueous solution 0.05 parts as solids Toner according to the following procedure using each of the above components Mother particles were produced.

Polymer primary particle dispersion B1 (core) in a mixer (volume 12 liters, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device For use) 4020.76 g and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 12 ° C. for 5 minutes. Subsequently, while stirring at an internal temperature of 12 ° C., 0.52 part of a 5% aqueous solution of ferrous sulfate as FeSO ₄ .7H ₂ O was added over 5 minutes, and then the cyan pigment dispersion 1
84.28 g was added at a constant rate with a pump. At that time, the flow rate of the pump was adjusted, and the total cyan pigment dispersion was added over 6 minutes. Thereafter, the mixture was uniformly mixed at an internal temperature of 12 ° C., and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content relative to the resin solid content was 0.10 parts). Thereafter, the temperature was raised to 54 ° C. over 75 minutes, and further raised to 56 ° C. over 170 minutes. Here, when the volume median diameter (Dv50) and the particle size distribution (Dv / Dn) were measured using a multisizer, they were 6.5 μm and 1.091. The rate of increase in the pigment concentration was 0.478 as calculated using the formula (1). Thereafter, the polymer primary particle dispersion B2 (for shell) is added over 20 minutes and held for 60 minutes, followed by addition of 20% DBS aqueous solution (6 parts as solids) over 10 minutes, and then 30 The temperature was raised to 95 ° C. over a minute, and stirring was continued over 120 minutes until the average circularity reached 0.972. Then, it cooled to 30 degreeC over 30 minutes, and obtained the slurry. At this time, Dv50 of the particles was 6.97 μm, and the average circularity was 0.971.
Thereafter, a developing toner Cy1 was obtained in the same manner as Ma1.

[Reference Example 2]
<Manufacture of developing toner Cy2>
A developing toner Cy2 was obtained in the same manner as the developing toner Cy1 except that the cyan pigment dispersion was added over 25 minutes.

<Preparation of black colorant dispersion>
Carbon black produced by a furnace method with a toluene extract having a UV absorbance of 0.02 and a true density of 1.8 g / cm ³ in a stirrer vessel equipped with a propeller blade (Mitsubishi Chemical Black, Mitsubishi Carbon Black) MA100S) 20 parts, anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen S-20D) 1 part, nonionic surfactant (manufactured by Kao Corporation, Emulgen 120) 4 parts, ion with conductivity 1 μS / cm 75 parts of exchange water was added and predispersed to obtain a pigment premix solution. The volume cumulative 50% diameter Dv50 of carbon black in the dispersion after premixing was about 90 μm. Supply the premix liquid as a raw slurry to a wet bead mill,
One-pass distribution was performed. Note that zirconia beads (true density 6.0 g / cm ³ ) having a diameter of 120 mmφ, a separator having a diameter of 60 mmφ, and a diameter of 50 μm were used as a dispersion medium. The effective internal volume of the stator is about 2 liters, and the media filling volume is 1
. Since it is 4 liters, the media filling rate is 70%. When the rotational speed of the rotor is constant (the peripheral speed at the tip of the rotor is about 11 m / sec), the premix slurry is supplied from the supply port by a non-pulsating metering pump at a supply speed of about 40 liters / hr, and reaches a predetermined particle size. The product was acquired from the outlet. During operation, cooling was performed while circulating cooling water at about 10 ° C. from the jacket to obtain a black colorant dispersion.

[Reference Example 3]
<Manufacture of developing toner Bk1>
Polymer primary particle dispersion B1 (for core) 90 parts as solid content Polymer primary particle dispersion B2 (for shell) 10 parts as solid content
Black colorant dispersion (pigment concentration 20.0%) 6 parts as colorant solids
20% DBS aqueous solution 0.1 parts as solid content Toner base particles were produced by the following procedure using the above components.

Polymer primary particle dispersion B1 (core) in a mixer (volume 12 liters, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device For use) 4511.65 g and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 12 ° C. for 5 minutes. Subsequently, while stirring at an internal temperature of 12 ° C., 0.52 part of a 5% aqueous solution of ferrous sulfate as FeSO ₄ · 7H ₂ O was added over 5 minutes, and then 3000.78 g of the black colorant dispersion was pumped. At a constant rate. At that time, the flow rate of the pump was adjusted, and the total black colorant dispersion was added over 6 minutes. Thereafter, the mixture was uniformly mixed at an internal temperature of 12 ° C., and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content relative to the resin solid content was 0.20 part). Thereafter, the temperature was raised to 54 ° C. over 75 minutes, and further raised to 56 ° C. over 170 minutes. Here, when the volume median diameter (Dv50) and the particle size distribution (Dv / Dn) were measured using a multisizer, they were 6.8 μm and 1.092. The rate of increase in the pigment concentration was 0.580 as calculated using Equation (1). Thereafter, the polymer primary particle dispersion B2 (for shell) is added over 20 minutes and held for 60 minutes, followed by addition of 20% DBS aqueous solution (6 parts as solids) over 10 minutes, and then 30 The temperature was raised to 92 ° C over a period of time, and stirring was continued over 120 minutes until the average circularity reached 0.972. Then, it cooled to 30 degreeC over 30 minutes, and obtained the slurry. At this time, the particle had a Dv50 of 6.99 μm and an average circularity of 0.968.
Thereafter, a developing toner Bk1 was obtained in the same manner as Ma1.

[Reference Example 4]
<Manufacture of developing toner Bk2>
A developing toner Bk2 was obtained in the same manner as the developing toner Bk1, except that the cyan pigment dispersion was added over 30 minutes.

Claims (2)

A method for producing a toner for developing an electrostatic charge image comprising an aggregation step of a magenta pigment dispersion and a polymer primary particle,
A method for producing a toner for developing an electrostatic charge image, wherein the magenta pigment concentration increasing rate in the aggregation step is 0.140% / hour or more and 0.640% / hour or less. The electrostatic charge image developing toner is a toner having a core-shell structure having a core layer and a shell layer,
The aggregation step includes a first aggregation step of forming the core layer and a second aggregation step of forming a shell layer on the core layer;
2. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein a concentration increase rate of the magenta pigment in the first aggregation step is 0.140% / hour or more and 0.640% / hour or less.