JP6503797B2 - Negatively charged toner for electrostatic image development - Google Patents

Description

  The present invention relates to a negatively charged toner for electrostatic image development, which is excellent in high image quality, low temperature fixability and blocking resistance.

Negatively charged toner for electrostatic charge image development is used in image formation for visualizing an electrostatic charge image in a printer, a copier, a facsimile machine, and the like. For example, in the case of image formation by electrophotography, an electrostatic latent image is first formed on a photosensitive drum, then developed with toner, transferred to a transfer paper or the like, and fixed by heat or the like. Image formation is performed.
As a negatively charged toner for electrostatic image development, a charge control agent, a releasing agent, a magnetic material, etc. are usually dry mixed with a binder resin and a coloring agent, if necessary, and then melt-kneaded with an extruder, etc. Subsequently, for the purpose of imparting various performances such as fluidity to toner particles obtained by the so-called melt-kneading pulverization method of pulverizing and classification, for example, a form in which solid fine particles such as silica are adhered to the surface as external additive Is used.

In recent years, there has been a demand for higher definition image quality in image formation for copying machines, printers, etc.
Polymerization methods such as a suspension polymerization method, an emulsion polymerization aggregation method, and a solution suspension method, which can easily control the particle size and particle size distribution of toner particles, have been proposed.
Furthermore, with the widespread use of copying machines and printers in recent years, in addition to the demand for image quality, toners that are particularly excellent in high-speed printing and low energy fixability are desired, and the low temperature fixability of toner is improved. It has been tried. In order to achieve low temperature fixing, a method of lowering the glass transition temperature of the binder resin and a method of using a crystalline resin in combination are often used, but the low temperature fixing property, the blocking resistance and the high temperature offset resistance are usually There is a trade-off relationship, and it is desirable to achieve both.

To solve these problems, there is a method of maintaining the blocking resistance while maintaining the low temperature fixability of the toner by the core-shell structure in which a hard shell layer is formed on the surface of the core made of low viscoelastic resin excellent in low temperature fixability. It has been done.
When forming core-shell structure, if shell particles are attached and then heated at high temperature, fusion of core particles and shell particles proceeds simultaneously with the occurrence of shell particles being buried, resulting in uncoated parts. It is known that the blocking resistance is insufficient. On the other hand, if the amount of the shell component is too large, the low temperature fixability of the toner is impeded, and if the amount of the shell component is too small, the non-coated portion is generated and the core component is exposed on the toner surface, and the expected blocking resistance performance can not be obtained. It has been known.

Patent Document 1 attempts to achieve both low-temperature fixability and heat-resistant storage stability by forming a granular convex portion integrated at a coverage of 10% to 80% with respect to a spherical toner core surface. In Patent Document 2, the core mainly contains a crystalline resin, the shell is 15% by mass or more and 120% by mass or less with respect to the core, and the shell has a hemispherical protrusion having a step difference of 0.3 μm or more. We are trying to balance the nature and the cleanability.
In any of the patent documents, the shell particles are not embedded but present in the form of protrusions on the toner surface, but the presence or absence of the shell and the degree of improvement of the blocking resistance are not described.

  In Patent Document 3, an intermediate layer composed of inorganic fine particles or organic fine particles is formed on the surface of toner inner core particles, and an outer shell layer is formed on the surface, thereby attempting to achieve both fixability and heat resistance. Although an example using a benzoguanamine resin or tricalcium phosphate as an intermediate layer is shown, it is disadvantageous for obtaining low temperature fixability because a component having no softening property is contained in the intermediate layer.

JP 2008-233430 A JP 2005-274964 A JP 2003-91093

  The present invention has been made in view of the above-mentioned problems, and provides a negatively charged toner for electrostatic image development, which is compatible with low temperature fixability and blocking resistance, and is excellent in image quality.

  The most effective form for achieving both low temperature fixability and blocking resistance is that the shell particle is thinly coated on the surface of the core particle having low temperature fixability at a high coverage, and moreover the core particle surface It is a form that is easy to stay at.

The present invention is based on this finding, and the gist of the present invention is as follows.
An intermediate layer having a polarity opposite to that of the core particle is formed in the aqueous medium on the surface of the core particle containing a <1> binder resin, a colorant and a wax, and then the polarity of the intermediate layer is reversed on the surface of the intermediate layer. A negatively charged toner for electrostatic image development, in which shell particles are formed by adhering shell particles containing at least a binder resin, wherein the intermediate layer has the following repeating structure (A) or (B): A negatively charged toner for electrostatic image development comprising a water soluble cationic resin.

[In the above-mentioned repeating structures (A) and (B), R ¹ and R ² each independently represent a hydrogen atom, or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, X ⁻ Is a halogen ion or a benzenesulfonic acid ion or an alkylbenzenesulfonic acid ion. ]
When the glass transition point of a <2> core particle is set to Tg1, and the glass transition point of a shell particle is set to Tg2,
25 ° C ≦ Tg1 ≦ 55 ° C
55 ° C ≦ Tg2
Tg2-Tg1 ≧ 10 ° C.
<1> the negatively charged toner for electrostatic image development according to <1>.
<3> The negatively charged toner for electrostatic image development according to any one of <1> to <3>, wherein the shell particles contain a sulfonic acid or a sulfonate.
<4> The negatively charged toner for electrostatic image development according to any one of <1> to <3>, which contains an ester wax.
<5> The negatively charged toner for electrostatic image development according to <4>, wherein the ester wax is represented by the following structural formula (1).

[In Formula (1), R ³ is a di- to 8-hydric neopentyl polyol residue, R ⁴ is a linear alkyl group having 13 to 25 carbon atoms, and p is an integer of 2 to 8. ]

According to the present invention, it is possible to provide a negatively charged toner for electrostatic image development, which achieves both low temperature fixability and blocking resistance.
This effect is achieved by providing shell layers with high blocking resistance at a high coverage rate after providing an intermediate layer comprising a water-soluble cationic resin containing quaternary ammonium salt in an aqueous medium on the surface of core particles having low temperature fixability. It is obtained by adhering uniformly. This novel core-shell structure achieves more effective low temperature fixability.

In the present invention, those in the state before having an intermediate layer and shell particles are referred to as core particles, particles having an intermediate layer on the core particles are referred to as intermediate layer-forming particles, and shell particles on the intermediate layer-forming particles. Those having a core-shell structure having the following are referred to as toner base particles, and those having an external additive on the surface of the toner base particles are referred to as toner.
The toner of the present invention contains at least a binder resin and a colorant, and may further contain a wax, a charge control agent, and the like as required.
In the present invention, when forming the intermediate layer on the core particle and when providing the shell particle layer on the intermediate layer-forming particle, the core particle and the material forming the intermediate layer have reverse polarity, and the surface of the intermediate layer-forming particle By using the reverse polarity of and the shell particles to form electrostatically adhering or adhering them, it is possible to uniformly adhere shell particles with high blocking resistance at a high coverage.

<Core particle>
The core particles contain at least a binder resin, a colorant and a wax, and may further contain a charge control agent and the like as required.
Furthermore, it is more preferable that the core particle has a core-shell structure by a known method.
By making the core particles into a core-shell structure, the balance between low temperature fixability and blocking resistance is further improved.

The binder resin is not particularly limited as long as it is generally used as a binder resin when producing a toner, and examples thereof include polystyrene resins, poly (meth) acrylic resins, polyolefin resins, and epoxy resins. Examples thereof include resins, thermoplastic resins such as polyester resins, and mixtures of these resins.
As a monomer component used for producing a binder resin, monomers generally used in producing a binder resin of toner can be appropriately used.

For example, a polymerizable monomer having an acidic group (hereinafter sometimes referred to simply as an acidic monomer), a polymerizable monomer having a basic group (hereinafter simply referred to as a basic monomer) ), Any polymerizable monomer having neither an acidic group nor a basic group (hereinafter, may be referred to as another monomer) can be used.
However, it is important to design the zeta potential of the core particles to be negative.
Therefore, the use of a basic monomer is required to be 15 wt% or less, preferably 10 wt% or less, with respect to the entire resin.

When using a polystyrene resin and a poly (meth) acrylic resin, the following monomers are mentioned as an example.
As the acidic monomer, a polymerizable monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, a polymerizable monomer having a sulfonic acid group such as sulfonated styrene, Examples thereof include polymerizable monomers having a sulfonamide group such as vinyl benzene sulfonamide.

Examples of basic monomers include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocycle-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone, and amino acids such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate. (Meth) acrylic acid ester etc. which have group are mentioned.
These acidic monomers and basic monomers contribute to the stabilization of the core particles in water when the core particles are produced by a suspension polymerization method, an emulsion polymerization aggregation method, a melt suspension method or the like. It may be used alone or in combination of two or more kinds, and may be present as a salt with a counter ion.

  As other monomers, styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-t-butylstyrene, p-n-butylstyrene and p-n-nonylstyrene, methyl acrylate, acrylic acid Acrylic esters such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , Methacrylates such as isobutyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, acrylamide, N-propyl acrylamide, N, N-dimethyl acrylamide, N, N-dipropyl acrylamide, N, N Dibutyl acrylamide, and the like. The other monomers may be used alone or in combination of two or more.

  When a binder resin is used as a crosslinked resin, a polyfunctional monomer is used together with the above-mentioned polymerizable monomer, and, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Examples include dimethacrylate, tetraethylene glycol dimethacrylate, hexaethylene glycol dimethacrylate, nona ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, diallyl phthalate and the like.

Among them, difunctional polymerizable monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional polymerizable monomers may be used alone or in combination of two or more.
It is also possible to use polymerizable monomers having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like.

  If necessary, known chain transfer agents can be used. Specific examples of the chain transfer agent include t-dodecyl mercaptan, dodecanethiol, diisopropyl xanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is used in an amount of 0 to 5% by weight based on the polymerizable monomer.

  If necessary, known polymerization initiators can be used alone or in combination of two or more. For example, a peroxidase such as potassium persulfate, sodium persulfate, ammonium persulfate and the like, and a redox initiator combining these persulfates as one component with a reducing agent such as sodium acid sulfite, hydrogen peroxide, 4, 4 Water-soluble polymerization initiators such as' -azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, etc., and redoxs combining these water-soluble polymerization initiators as one component with reducing agents such as ferrous salts Initiators, benzoyl peroxide, 2,2'-azobis-isobutyronitrile, etc. are used. These polymerization initiators may be added to the polymerization system at any time before, simultaneously with, or after addition of monomers, and these addition methods may be combined as needed.

  If necessary, known suspension stabilizers can be used. Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like. These may be used singly or in combination of two or more, and may be used in an amount of 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

The polymerization initiator and the suspension stabilizer may be added to the polymerization system at any time before, simultaneously with, or after the addition of the polymerizable monomer, and the addition method of these may be added if necessary. It may be combined.
In addition, a pH regulator, a polymerization degree regulator, an antifoamer, etc. can be suitably added to the reaction system.

When the binder resin is polymerized by emulsion polymerization, known emulsifiers can be used, but one or more selected from cationic surfactants, anionic surfactants and nonionic surfactants can be used. An emulsifier can be used in combination.
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, and examples of the anionic surfactant include And fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium lauryl sulfate and the like. Examples of nonionic surfactants include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose and the like. Can be mentioned.

  The amount of the emulsifier used is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. In addition, one or two or more of these emulsifiers may be used in combination as a protective colloid, for example, polyvinyl alcohols such as partially or completely saponified polyvinyl alcohol, and cellulose derivatives such as hydroxyethyl cellulose.

The binder resin preferably has a number average molecular weight in gel permeation chromatography (hereinafter referred to as GPC) of 2000 or more, more preferably 2500 or more, still more preferably 3000 or more, preferably 50,000 or less Preferably, it is 40,000 or less, more preferably 35,000 or less. In addition, the weight average molecular weight similarly determined is preferably 20,000 or more, more preferably 30,000 or more, still more preferably 40,000 or more, preferably 700,000 or less, more preferably 600,000 or less, more preferably It is desirable that it is 500,000 or less. When the number average molecular weight and the weight average molecular weight of the binder resin are in the above ranges, it is desirable because the durability, the storage stability and the fixing property of the toner become good.

The glass transition temperature (Tg) of the binder resin is not particularly limited as long as the effects of the present invention are not impaired, but is preferably 25 ° C. or more, more preferably 35 ° C. or more, preferably 65 ° C. or less More preferably, it is 60 degrees C or less, More preferably, it is 55 degrees C or less.
The Tg of the core particles is preferably 25 ° C. or more, more preferably 30 ° C. or more, and still more preferably 35 ° C. or more. Moreover, Preferably it is 55 degrees C or less, More preferably, it is 50 degrees C or less, More preferably, it is 45 degrees C or less. The core particles contain at least a colorant and a wax in addition to the binder resin, but the binder resin and the wax may be partially compatible with each other and the Tg of the core particles may be lower than the Tg of the binder resin. It is necessary to adjust the Tg of the binder resin according to the wax to be used so that the Tg of the core particles is in the above range.
Waxes can be used as anti-offset agents. There is a trade-off relationship between low temperature fixability, blocking resistance and high temperature offset resistance, and in order to achieve both of them, it is preferable to use a wax as an offset inhibitor at the same time as making the toner into a core-shell structure .

  As the wax used in the toner of the present invention, known waxes can be optionally used, and specifically, low molecular weight polyethylene, low molecular weight polypropylene, olefin wax such as copolymerized polyethylene, paraffin wax, behenic acid Ester-based waxes having long-chain aliphatic groups such as behenyl, montanic acid ester and stearyl stearate, plant-based waxes such as hydrogenated castor oil, carnauba wax, ketones having long-chain alkyl groups such as distearyl ketone, alkyl groups Silicones, higher fatty acids such as stearic acid, long chain fatty acid alcohols, long chain fatty acid polyhydric alcohols such as pentaerythritol, and esters or partial esters thereof, higher fatty acid amides such as oleic acid amide and stearic acid amide, etc. Exemplified, preferably Hydrocarbons such as paraffin wax or Fischer-Tropsch wax, ester wax, and silicone waxes.

  Particularly preferred are ester waxes. More preferable is neopentyl polyol ester represented by the following general formula (1).

In formula (1), R ³ is a di- to 8-hydric neopentyl polyol residue, R ⁴ is a linear alkyl group having 13 to 25 carbon atoms, and p is an integer of 2 to 8.

In the present invention, the waxes may be used alone or in combination. In order to improve the fixing property, the melting point is preferably 120 ° C. or less, more preferably 110 ° C. or less, still more preferably 100 ° C. or less, preferably 40 ° C. or more, and further preferably 50 ° C. or more. If the melting point is too high, the effect of reducing the fixing temperature may be poor. If the melting point is too low, problems may occur in blocking resistance and storage stability.

  In the present invention, the amount of the wax is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and still more preferably 5 parts by mass or more in 100 parts by mass of the toner. Moreover, it is preferable that it is 40 mass parts or less, More preferably, it is 35 mass parts or less, More preferably, it is 30 mass parts or less. If the wax content in the toner is too low, performance such as high temperature offset may not be sufficient. If too much, the blocking resistance is not sufficient, or the wax may leak out of the toner to contaminate the device. May.

  As a method of blending the wax in the polymerization method, it is preferable to previously disperse the wax in water to a volume average particle size of 0.01 μm or more and 2.0 μm or less. It is more preferable that it is 1.0 micrometer or less, and it is still more preferable that it is 0.5 micrometer or less.

  A well-known coloring agent can be used arbitrarily as a coloring agent. Specific examples of colorants include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chromium yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, Any of known dyes and pigments such as disazo dyes and condensed azo dyes and pigments can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, monoazo type, condensed azo type dye, yellow pigment, quinacridone, monoazo type dye and pigment, and phthalocyanine blue as cyan type. The colorant is preferably used in an amount of 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the toner.

  The core particle of the present invention may be produced by any method and is not particularly limited. In the case of the pulverization method, after kneading, pulverizing and classifying each component, a dispersion liquid dispersed in an aqueous medium using an emulsifying agent may be used if necessary. In the case of a polymerization method such as a suspension polymerization method, an emulsion polymerization / aggregation method, or a dissolution suspension method, the slurry liquid at the time of core particle production can be used as it is.

  In the case of production by a suspension polymerization method, colorants, waxes, polymerization initiators and, if necessary, additives such as polar resins, charge control agents and crosslinking agents are contained in the monomers of the above-mentioned binder resin. In addition, a homogeneously dissolved or dispersed monomer composition is prepared. The monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer and the like. Preferably, the stirring speed and time are adjusted and granulated so that droplets of the monomer composition have the desired toner particle size. Thereafter, stirring is performed to maintain the particle state and prevent sedimentation of the particles by the action of the dispersion stabilizer, and core particles can be obtained by polymerization. Then, as described later, toner matrix particles having a core-shell structure can be obtained through the steps of forming an intermediate layer on the surface of the core particle and covering the shell particle on the surface of the intermediate layer.

In the case of production by the emulsion polymerization / aggregation method, a colorant dispersion liquid, wax dispersion liquid, etc. are prepared, and then by emulsion polymerization in the presence of primary particles of a binder resin monomer obtained by emulsion polymerization or wax. After passing through the step of aggregating by mixing the obtained polymer primary particles of the wax-containing binder resin monomer with the colorant dispersion liquid, the wax dispersion liquid, etc. and heating, etc. And, after passing through a step of aggregation by mixing with a polymer primary particle of a binder resin monomer obtained by emulsion polymerization in the presence of a colorant and a wax dispersion or the like, a further ripening step is carried out. And a process of aggregation by mixing with a primary particle of a polymer of binder resin monomer obtained by emulsion polymerization in the presence of a colorant and a wax, a wax dispersion, etc., and heating, etc. After, further ripening process And the like and how to go through is. Core particles can be obtained by these methods. Then, as described later, toner matrix particles having a core-shell structure can be obtained through the steps of forming an intermediate layer on the surface of the core particle and covering the shell particle on the surface of the intermediate layer. When the binder resin monomer is polymerized in the presence of a colorant among the production methods of the above-mentioned emulsion polymerization / aggregation method, the metal in the colorant affects the radical polymerization, making it difficult to control the molecular weight and the rheology of the resin. Since a primary polymer particle of the above may not be obtained, it is preferable not to add a colorant at the time of emulsion polymerization but to add a colorant dispersion in the aggregation step.

  The volume average particle size of the primary polymer particles 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 1 μm or less . When the particle size is smaller than the above range, it may be difficult to control the aggregation rate in the aggregation step, and when it is larger than the above range, the particle size of core particles obtained by aggregation tends to be large, It may be difficult to obtain a toner of the desired particle size.

In order to disperse the wax with a suitable dispersed particle size in the toner, it is preferable to use so-called seed polymerization in which the wax is added as a seed during emulsion polymerization. Since the wax is finely and uniformly dispersed in the toner by being added as a seed, it is possible to suppress the deterioration of the chargeability and heat resistance of the toner.
In addition, a wax / long-chain polymerizable monomer dispersion obtained by dispersing the wax with a long-chain polymerizable monomer such as stearyl acrylate in advance in an aqueous dispersion medium is prepared, and the wax / long-chain polymerizable monomer is prepared. The polymerizable monomer can also be polymerized in the presence of

  The colorant is preferably used in the state of being dispersed in water in the presence of an emulsifier, and the volume average particle diameter of the colorant particles is 0.01 μm or more, more preferably 0.05 μm or more, and 3 μm or less, more preferably It is 1 μm.

  In the aggregation step in the emulsion polymerization / aggregation method, the above-mentioned primary polymer particles, colorant particles, and optionally, charge control agent, wax and other compounding components are mixed simultaneously or sequentially, but the respective components are dispersed in advance. A liquid, that is, a polymer primary particle dispersion, a colorant particle dispersion, and optionally, a charge control agent dispersion and a wax fine particle dispersion are prepared, and these are mixed to obtain a mixed dispersion. In view of the uniformity of the

  In the emulsion polymerization / aggregation method, aggregation is usually carried out in a tank equipped with a stirrer, but there are methods of heating, methods of adding an electrolyte, and methods of combining these. When trying to aggregate polymer primary particles under stirring to obtain particle aggregates of a desired size, the particle diameter of the particle aggregates is controlled from the balance between the cohesion between particles and the shearing force by stirring. However, the cohesion can be increased by heating or adding an electrolyte.

In the case of performing aggregation by adding an electrolyte, any of an acid, an alkali, and a salt, or any of an organic type and an inorganic type may be used. Specifically, as an acid, hydrochloric acid, nitric acid, sulfuric acid, citric acid Etc., as alkali, sodium hydroxide, potassium hydroxide, ammonia water etc., as a salt, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , Ca
Cl 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 can be mentioned. Among these, inorganic salts having a divalent or higher polyvalent metal cation are preferable.

The amount of electrolyte added varies depending on the type of electrolyte, the target particle size, etc., but is preferably 0.02 parts by mass or more, and more preferably 0.05 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. preferable. Further, 25 parts by mass or less is preferable, 15 parts by mass or less, and particularly 10 parts by mass or less is preferable. If the amount added is too small, the progress of aggregation will be delayed, and fine particles of 1 μm or less may remain even after aggregation, or problems such as the average particle diameter of the obtained particle aggregate will not reach the target particle diameter If the amount is too large, it is likely to cause rapid aggregation, making it difficult to control the particle size.
The resulting agglomerated particles may cause problems such as inclusion of coarse powder and amorphous particles. The aggregation temperature in the case of performing aggregation by adding an electrolyte is 20 ° C. or more, more preferably 30 ° C. or more, and 80 ° C. or less, more preferably 70 ° C. or less.

  The time required for aggregation is optimized according to the device shape and processing scale, but in order for the particle size of the toner to reach the target particle size, it is usually maintained at the above-mentioned predetermined temperature for at least 30 minutes or more. desirable. The temperature may be raised at a constant rate, or may be raised stepwise, until reaching a predetermined temperature.

  In order to increase the stability of the particle aggregate obtained in the aggregation step, it is preferable to perform fusion within the aggregated particles in the aging step after the aggregation step. The temperature of the ripening step is preferably not less than Tg of the polymer primary particles, more preferably not less than 5 ° C. higher than Tg, and preferably not more than 80 ° C. higher than Tg, more preferably 60 ° C. higher than Tg It is below. The time required for the ripening step varies depending on the shape of the target toner, but after reaching at least Tg of the polymer primary particles, it is usually maintained for 0.1 to 10 hours, preferably 0.5 to 5 hours. Is desirable.

  It is preferable to add a surfactant, adjust the pH, or use both in combination after the aggregation step, preferably before the aging step or during the aging step. As the surfactant used here, one or more emulsifiers can be selected from emulsifiers which can be used when producing polymer primary particles, but the emulsifier used particularly when polymer primary particles are produced It is preferable to use the same as. Although the addition amount in the case of adding a surfactant is not limited, it is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 100 parts by mass of the solid component of the mixed dispersion. Is 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less. By adding a surfactant after the aggregation step and before the completion of the ripening step or adjusting the pH, it is possible to suppress aggregation and the like of particle aggregates aggregated in the aggregation step, and after the ripening step In some cases, coarse particle formation can be suppressed.

  Particle aggregates before the aging step are considered to be aggregates of electrostatic or physical aggregation of polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregates are mutually fused doing. By controlling the temperature, time, etc. of this ripening step, various shapes can be selected according to the purpose, such as a bowl shape in which polymer primary particles are aggregated, a potato type in which fusion proceeds, and a spherical shape in which fusion further proceeds. The toner can be manufactured.

  In the dispersion of the core particles, it is preferable to remove the dispersant, the emulsifier, and the like present in the core particle dispersion by washing within a range in which aggregates of the core particles are not generated. For example, in the case of core particles obtained by the polymerization method, after removing the emulsifier and soluble impurities contained in water by dehydrating and washing the slurry liquid at the time of core particle production, use the method of redispersion in water Can.

<Middle class>
In the toner of the present invention, an intermediate layer is formed on the surface of core particles. This intermediate layer is a basis for uniformly covering the outermost shell particles, and the shell particles adhere to any part of the intermediate layer surface by reversely designing the chargeability of the intermediate layer and the shell particles. As a result, a thin and dense shell layer can be formed, and as a result, good blocking resistance can be obtained without losing low temperature fixability.
In the present invention, the form of the intermediate layer is not particularly limited, but the intermediate layer is a resin coating layer made of a water-soluble cationic resin containing a quaternary ammonium salt described below. The resin coating layer made of a water-soluble cationic resin (hereinafter sometimes referred to as a water-soluble resin coating layer) is a layer of a film having a substantially smooth surface although it has irregularities derived from the irregularities of the core particle surface. Means The water-soluble resin coating layer may contain a plurality of water-soluble cationic resins as long as the effects of the present invention are not significantly impaired. Here, water solubility indicates that the solubility in water at 25 ° C. is 1 g / 100 ml or more.

  Water-soluble cationic resins containing quaternary ammonium salts can be obtained by ammonium chlorination of polymers containing amino groups. It can also be obtained by polymerizing a monovinyl monomer containing an ammonium salt. However, the method of producing the water-soluble cationic resin is not limited to these methods.

  It is essential that the intermediate layer of the toner of the present invention contains a water-soluble cationic resin having the following repeating structure (A) or (B).

In the above repeating structures (A) and (B), R ¹ and R ² each independently represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and X ⁻ represents , A halogen ion, or a benzene sulfonate ion or an alkyl benzene sulfonate ion. ]

In the quaternary ammonium salt represented by the above repeating structural (A) and (B), X ^- is preferably a chloride ion or toluenesulfonate ion, ^{R 1} and ^{R 2} are each independently _CH 3, It is preferably an alkyl group such as C ₂ H ₅ or C ₃ H ₇ .

  Examples of quaternizing agents used for ammonium chlorination of amino groups include alkyl halides such as methyl iodide, ethyl iodide, methyl bromide and ethyl bromide, methyl para-toluenesulfonate, para-toluene sulfone And ethyl ester and alkyl ester of para-toluenesulfonic acid such as propyl para-toluenesulfonic acid.

  The molecular weight of the water-soluble cationic resin used in the intermediate layer is not particularly limited, but the weight average molecular weight in GPC is 3,000 or more, and preferably 1,000,000 or less. When the weight-average molecular weight is 3,000 or less, the adsorptive power to the core particle surface may be weakened, and when it exceeds 1,000,000, the polymer chain becomes long, and thus can be adsorbed in a cross-linked manner to a plurality of core particles There is sex.

The content of the intermediate layer is not particularly limited as long as the effects of the present invention are not impaired, but generally, it is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, with respect to 100 parts by mass of core particles. Also preferably, it is 3 parts by mass or less. When the amount is less than 0.01 parts by mass, it becomes difficult to obtain the intended intermediate layer as a uniform layer, and when it is used in excess of 3 parts by mass, the fixability of the toner tends to be deteriorated.
<Method of forming intermediate layer on core particle>

  When forming the intermediate layer on the surface of the core particle, it is preferable from the viewpoint of operability to use the water-soluble cationic resin described above as the intermediate layer component in the form of an aqueous solution. An aqueous solution of a water-soluble cationic resin containing a quaternary ammonium salt is added to the core particle dispersion and mixed to form an intermediate layer.

Although the mixing temperature of the core particle and the water-soluble cationic resin aqueous solution at the time of intermediate layer formation is not particularly limited, mixing at a temperature lower by 10 ° C. or more than the Tg of the core particle prevents the formation of aggregates of the core particle, and the core particle and resin It is preferable because the aqueous solution can be uniformly mixed.
When a water-soluble cationic resin is used as an aqueous solution in the intermediate layer, it adsorbs to core particles in a relatively short time. This is considered to be due to the fact that the number of adsorption sites of the water-soluble polymer is large and that it can take a relatively free form in water.

After formation of the intermediate layer, excess water-soluble resin not adhering to the surface of the core particles remaining in the aqueous medium can be removed by washing. As a specific method, the same method as washing of core particles can be used.
Alternatively, the ratio of the core particle to the water-soluble resin can be strictly adjusted so that the excess resin which does not adhere to the surface of the core particle does not remain in the aqueous medium. In this case, the cleaning can be omitted.

  As a method of confirming that the intermediate layer is formed, the sign of the zeta potential of the dispersion before and after the formation of the intermediate layer is reversed, or the charge amount of the powder obtained by washing and drying the dispersion before and after the formation of the intermediate layer It can be confirmed that the sign of is reversed.

<Shell particle>
Resin fine particles are preferable as shell particles to be coated on the surface of the intermediate layer. Further, in the present invention, in order to provide the shell particle layer on the intermediate layer-forming particles by electrostatic attachment or fixation, the shell particles need to be designed such that the zeta potential at pH 2 to 4 is negative. Specifically, a negatively chargeable resin is used for the shell particles as described later.

When the shell particle is a fine resin particle, the resin component is not particularly specified, but may be, for example, a resin generally used as a binder resin, such as styrene type, acrylic type, ester type, or a copolymer type or a blend type of them.
The shell particles may contain a colorant, a wax, a charge control agent, a charge control resin and the like by a known method.

The weight average molecular weight of the resin shell particles is preferably 10,000 to 1,000,000, more preferably 10,000 to 500,000, and particularly preferably 10,000 to 300,000. When the weight average molecular weight of the resin shell particles is too low, the blocking resistance of the toner may be deteriorated or the durability in the cartridge may be deteriorated. When the weight average molecular weight is too high, the low temperature fixability may be deteriorated.
The Tg of the resin shell particles is preferably 55 ° C. or more, more preferably 60 ° C. or more, preferably 100 ° C. or less, more preferably 80 ° C. or less, and still more preferably 75 ° C. or less. In addition, it is preferable that the Tg of the core particle is higher than
+10) ° C. or higher is more preferable, (Tg of core particle +15) ° C. or higher is more preferable, (Tg of core particle +50) ° C. or lower is preferable, and (Tg of core particle +40) ° C. or lower is more preferable. When the Tg of the resin shell particles is too low, the blocking resistance of the toner may be deteriorated, while when it is too high, the low temperature fixability may be deteriorated.

  The content of the shell particles is not particularly limited as long as the effects of the present invention are not impaired, but usually, the content is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more with respect to 100 parts by mass of the core particles. Moreover, preferably it is 8 mass parts or less. If the amount is less than 0.5 parts by mass, it is difficult to obtain an intended shell layer as a uniform layer, the storage stability is deteriorated, and if it exceeds 8 parts by mass, the fixability of the toner tends to be deteriorated.

  It is preferable to use a negatively chargeable resin for the shell particles because a thin and uniform shell layer is easily formed. The negatively chargeable resin is not particularly specified, but a resin obtained by copolymerizing a monomer having a carboxyl group; a sulfonic acid group; a sulfonamide group and a monomer generally used for a binder resin is preferable. At the same time as these monomers impart negative chargeability to the shell particles, they exhibit high negative zeta potential and also impart emulsion stability of the shell particles, so that aggregation of the shell particles occurs during formation of the shell layer. It becomes difficult to occur. Among these, a resin having a sulfonic acid or a sulfonate is preferable.

  The amount of the monomer unit having a functional group that imparts chargeability is preferably 0.5 to 15% by weight, more preferably 1 to 12% by weight, and particularly preferably 2 to 10% by weight in the resin. When the amount of the monomer is too small, the chargeability of the toner after forming the shell layer may be insufficient, and when it is too large, the reduction of the charge amount of the toner under high temperature and high humidity becomes large. Fog may occur.

The resin shell particles may be prepared by dispersing or emulsifying a resin in an aqueous medium, or may be prepared by a polymerization method such as emulsion polymerization or suspension polymerization. A polymerization method is desirable from the viewpoint of particle diameter control and easiness of micronization, and an emulsion polymerization method is more preferable from the viewpoint of particle diameter of fine particles and particle size distribution control.
When resin shell particles are produced by the emulsion polymerization method, they can be produced by the same emulsion polymerization method as the polymer primary particles of the binder resin monomer used in the above-mentioned emulsion polymerization / aggregation method.

  The volume average particle size of the shell particles is not particularly limited as long as the effects of the present invention are not impaired, but 20 nm or more is preferable, and 40 nm or more is more preferable. Moreover, 500 nm or less, preferably 150 nm or less is preferable.

As shell particles, various commercial products can also be used. For example, resin particles obtained by emulsifying and dispersing FCA-1001-NS (trade name, styrene / acrylic resin) manufactured by Fujikura Kasei Co., Ltd. in water by a known method may be mentioned.

<Method of Coating Shell Particles on Intermediate Layer (Capsule Process)>
Hereinafter, the step of coating the shell particles on the intermediate layer may be referred to as a capsule step.
Methods of producing a toner having a core-shell structure include a method of forming a core-shell structure by mixing shell particles in the latter half of the core particle forming step, and a method of coating shell particles on the surface of a finished core particle.

  In the case of the former mode, which is the conventional mode, the shell particle is embedded in the core particle during the manufacturing process, so the core particle component is exposed on the surface of the toner base particle. If it is intended to completely coat the core particles, it is necessary to coat a large amount of shell particles, resulting in the loss of low temperature fixability.

  On the other hand, in the latter case which is an embodiment to realize the present invention, since the intermediate layer and the shell particles are coated on the surface of the finished core particles, the shell particles do not get buried in the core particles in the manufacturing process, The particles can completely coat the core particles. In addition, the chargeability of the intermediate layer and the shell particles is opposite to each other, and the wettability of both resins is not high, which also has the effect of making the shell particles less likely to be embedded.

Also, the shell particles tend to adhere to the surface of the intermediate layer because the chargeability of the intermediate layer and the shell particles is opposite, but since the shell particles have the same chargeability, the shell particles are further formed thereon after the shell particle layer is formed. Adhesion is less likely to occur. Therefore, a thin and uniform shell layer can be easily formed.
From the above, even if the shell layer is thin, it is possible to maintain the blocking resistance, and as a result, it becomes a toner excellent in low temperature fixability.

The step of coating the shell particles on the intermediate layer (capsule step) is carried out by adding and mixing the shell particles in the intermediate layer-forming particle dispersion.
Since the water-soluble cationic resin used in the present invention contains a quaternary ammonium salt, it becomes positively charged under acidic conditions, particularly at a pH of 4.0 or less, and the intermediate layer-forming particles are also positively charged under the same pH conditions. For this reason, it is essential that the shell particles have a negative zwitter potential under these conditions, and the encapsulation step should be carried out under acidic conditions of pH 4.0 or less, preferably at pH 2 to 4.

  The mixing temperature of the intermediate layer-forming particles and the shell particles is not particularly limited, but a temperature lower by at least 10 ° C. than the lowest Tg of the core particles, the intermediate layer and the shell particles prevents formation of particle aggregates. It is preferable because homogeneous mixing can be performed.

  As a method of confirming that the shell layer is formed, the zeta potential of the dispersion before and after formation of the shell layer is reversed, or the charge amount after washing and drying the dispersion before and after formation of the shell layer is determined. When measured, it can be confirmed by reversing the sign.

<Washing and drying of toner mother particles>
The toner base particles coated with the shell particles are separated from the aqueous solvent, washed, dried, and optionally subjected to an external additive treatment to be provided to the negatively charged toner for electrostatic image development.
Although water is used as a liquid used for washing, it can also be washed with an aqueous solution of acid or alkali. Moreover, it can also wash | clean with warm water or a hot water, and can also use these methods together. Suspension stabilizers, emulsifiers, unreacted monomers and the like can be reduced and removed by passing through such a washing step. In the washing step, for example, it is preferable to repeat the operation of making the toner base particles into a thick slurry or wet cake form by filtering, decanting, etc., adding a liquid for fresh washing to this to disperse the toner base particles. Recovering the washed toner base particles in the form of a wet cake is preferable in terms of handling in the subsequent drying step.

  In the drying step, a fluid drying method such as a vibration type fluid drying method or a circulation type fluid drying method, a flash drying method, a vacuum drying method, a freeze drying method, a spray drying method, a flash jet method or the like is used. The operating conditions such as temperature, air volume, and degree of pressure reduction in the drying step are appropriately optimized based on the Tg of the toner base particles, the shape, mechanism, size and the like of the device used.

The volume average particle diameter of the toner of the present invention is preferably 3 μm or more, and more preferably 5 μm or more. Moreover, 15 micrometers or less are preferable, and also 10 micrometers or less are more preferable. The shape is preferably 0.90 or more, more preferably 0.92 or more, still more preferably 0.94 or more, and the average circularity measured using a flow type particle image analyzer FPIA-3000 is preferable. Is less than 0.99. If the average circularity is too small, charging deterioration may occur due to poor adhesion of the external additive to the toner base particles, which may cause a decrease in image density. If it is too large, cleaning failure due to the shape may occur.

<External additive>
In the present invention, an external additive can be added as needed to improve the flowability of the toner and the charge controllability. The external additive can be appropriately selected from various inorganic or organic fine particles and used. In addition, two or more types of external additives may be used in combination.
As the inorganic fine particles, various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, etc., boron nitride, titanium nitride , Various nitrides such as zirconium nitride, various borides such as zirconium boride, titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, copper oxide, aluminum oxide, cerium oxide, various oxides such as colloidal silica, titanium Acid, such as calcium titanate, magnesium titanate, strontium titanate, phosphate compounds such as calcium phosphate, sulfides such as molybdenum disulfide, magnesium fluoride, fluorides such as fluorocarbon, aluminum stearate, stearin Calcium, zinc stearate, can be used various metal soaps such as magnesium stearate, talc, bentonite, various carbon black or conductive carbon black, magnetite, ferrite or the like. As the organic fine particles, fine particles of styrene resin, acrylic resin, epoxy resin, melamine resin and the like can be used. In addition, fine particles containing fluorine atoms can be used to improve charge stability.

Among these external additives, particularly, silica, titanium oxide, alumina, zinc oxide, various carbon blacks, conductive carbon blacks and the like are suitably used. Also, the external additive may be a silane coupling agent such as hexamethyldisilazane (HMDS) or dimethyldichlorosilane (DMDS), a titanate coupling agent, a silicone oil, or a dimethyl silicone, on the surface of the inorganic or organic fine particles described above. Oil, modified silicone oil, silicone oil treatment agent such as amino-modified silicone oil, silicone varnish, fluorine-based silane coupling agent, fluorine-based silicone oil, or treatment agent such as coupling agent having amino group or quaternary ammonium base It can also be used that has been subjected to surface treatment such as hydrophobization. The treating agents can be used in combination of two or more.
The content of the external additive is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, preferably 5 parts by mass or less, more preferably 4 parts by mass with respect to 100 parts by mass of the toner base particles. It is below a mass part.

In the toner of the present invention, conductive fine particles may be used as an external additive from the viewpoint of charge control. The upper limit of the resistance of the conductive fine particles is usually 400 Ω · cm or less, preferably 200 Ω · cm or less, more preferably 100 Ω · cm or less, and still more preferably 60 Ω · cm or less. On the other hand, the lower limit is usually 0.1 Ω · cm or more, preferably 1 Ω · cm or more, more preferably 5 Ω · cm or more, and still more preferably 15 Ω · cm. Examples of the conductive fine particles include metal oxides such as conductive titanium oxide, silica, magnetite and the like, or those obtained by doping a conductive substance thereto, conjugated double bonds such as polyacetylene, polyphenylacetylene, poly-p-phenylene and the like Organic particles in which a conductive substance such as metal is doped into a polymer having carbon, carbon represented by carbon black and graphite, etc., but from the viewpoint of imparting conductivity without impairing the fluidity of the toner, conductive oxidation More preferred is one doped with titanium or its conductive material. The lower limit of the content of the conductive fine particles is usually 0.0 parts by mass to 5 parts by mass, preferably 0.1 parts by mass or more, and 0.2 parts by mass with respect to 100 parts by mass of the toner base particles. It is more preferable that it is more than. On the other hand, the upper limit of the content of the conductive fine particles is usually 3 parts by mass or less, preferably 2 parts by mass or less, and more preferably 1 part by mass or less.

<External addition method of external additive>
Examples of the method of adding the external additive include a method using a high-speed stirrer such as a Henschel mixer, and a method using an apparatus capable of applying a compressive shear stress.
The external additive toner can be prepared by a one-step external addition method in which all external additives are simultaneously added to the toner base particles and externally added, but can also be prepared by a partial external addition method in which external additives are externally added.
In order to prevent the temperature rise during external addition, it is preferable to install a cooling device in the container or to add a partial external stage.

<Others>
The negatively charged toner for electrostatic image development of the present invention may be used in any form of a two-component developer using toner together with a carrier or a magnetic or non-magnetic one-component developer using no carrier. When used as a two-component developer, as the carrier, magnetic substances such as iron powder, magnetite powder, ferrite powder or the like, or those obtained by applying a resin coating to the surface thereof or known magnetic carriers can be used. As a coating resin of the resin-coated carrier, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorocarbon resins, or mixtures thereof can be used.

EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples, "parts" means "parts by mass". Moreover, the live-action test was done by the following method.
Each particle diameter and zeta potential, circularity, electrical conductivity, thermal characteristics, etc. were measured as follows.

<Medium diameter measurement (D50)>
The median diameter (D50) of particles having a median diameter (D50) of less than 1 micron was determined using Nikkiso Co., Ltd. model Microtrac Nanotrac 150 (hereinafter abbreviated as Nanotrack) and its analysis software Microtrac Particle Analyzer Ver 10.1.2-019 EE. Using ion-exchanged water with a conductivity of 0.5 μS / cm as the solvent, solvent refractive index: 1.333, measurement time: 120 seconds, number of measurements: 5 times according to the method described in the instruction manual It measured and calculated the average value. The other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: true spherical, density: 1.04.

<Volume median particle size measurement (Dv 50)>
The volume median particle size (Dv 50) of particles having a volume median particle size (Dv 50) of 1 micron or more is a Beckman Coulter Multisizer III (aperture diameter 100 μm: or less,
The dispersion was measured using a multi-sizer (abbreviated as “a multisizer”) using Isoton II as a dispersion medium so that the dispersoid concentration was 0.03%.

<Mean circularity measurement>
The average circularity is obtained by dispersing the dispersoid in a dispersion medium (Celsheath: manufactured by Sysmex Corporation) so as to be 5720 to 7140 cells / μl, and the amount of HPF analyzed using a flow type particle analyzer (FPIA 3000: manufactured by Sysmex Corporation) It measured by HPF mode under conditions of 0.35 μl, HPF detection amount of 2000 to 2500.

<Electric conductivity measurement>
The measurement of the electrical conductivity was performed using a conductivity meter (CyberScan CON 100 manufactured by As One Corporation).

<Weight average molecular weight (Mw)>
The THF soluble components of the polymer primary particle dispersion and the shell particle dispersion were measured by gel permeation chromatography (GPC) under the following conditions.
Apparatus: Tosoh GPC apparatus HLC-8320, column: TOSOH TSKgel
SuperHM-H (two), solvent: THF, sample concentration: 0.1% by weight, calibration curve: standard polystyrene The interlayer aqueous solution was measured by gel permeation chromatography (GPC) under the following conditions.
Apparatus: Tosoh GPC apparatus HLC-8010, column: Tosoh TSKgel GMPWx1, solvent: 0.5 M acetic acid + 0.2 M aqueous solution of sodium nitrate, sample concentration: 0.2% by weight, calibration curve: polyethylene glycol

<Glass transition temperature (Tg) measurement>
It measured on the conditions of the temperature increase rate of 10 degree-C / min using the differential thermal analyzer (DSC200) made from SEIKO- ELECTRONICS CO., LTD. Tg was determined from the intersection of the extension of the baseline of the DSC curve and the tangent showing the maximum slope in the endothermic curve.

Preparation of Wax Dispersion A1
Heat to 90 ° C with 27.2 parts of paraffin wax (melting point 82 ° C), 2.8 parts of stearyl acrylate, 1.9 parts of 20% DBS aqueous solution, 68.1 parts of demineralized water, The mixture was stirred for 10 minutes using a company mark IIf model). Then, under 90 ° C. heating, start circulating emulsification under high pressure emulsifier at 20 MPa using a high pressure emulsifier, measure the particle size with Nanotrack and disperse until the median diameter (D50) becomes 250 nm or less Dispersion A1 was made. The final particle size (D50) was 244 nm.

Preparation of Wax Dispersion A2
Ester wax 29.8 parts of Nissan Electol WEP-10 (manufactured by NOF Corporation), 0.24 parts of decaglycerin decabehenate (acid value 3.2 mg KOH / g, hydroxyl value 27 mg KOH / g), 20% DBS The aqueous solution 2.75 parts and demineralized water 67.25 parts were heated to 90 ° C. and stirred for 20 minutes. Then, under 100 ° C heating, start circulating emulsification under pressure condition of 30MPa using high pressure emulsifier, measure particle diameter with Nanotrack, disperse until medium diameter (D50) becomes 245nm or less Wax dispersion A2 was made. The final particle size (D50) was 232 nm.

Preparation of Wax Dispersion A3
A wax dispersion A3 was prepared in the same manner as the wax dispersion A2, except that the ester wax was changed to Nissan elector WEP-5 (manufactured by NOF Corporation). The final particle size (D50) was 235 nm.

<Preparation of Polymer Primary Particle Dispersion B1>
36.3 parts of wax dispersion A1 and 260 parts of demineralized water are charged in a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentration device, and each raw material / auxiliary agent charging device, and a nitrogen stream is provided while stirring. The temperature was raised to 90 ° C. below.
Then, the mixture of the following monomers and emulsifier aqueous solution was added over 300 minutes, continuing stirring. The time at which the addition of the mixture of monomers / emulsifier aqueous solution was started was defined as polymerization start, and the following initiator aqueous solution 1 was added over 30 minutes after the start of polymerization from 270 minutes. Thereafter, the initiator aqueous solution 2 was added over 120 minutes. Thereafter, it was kept for 60 minutes while maintaining the internal temperature at 90 ° C. under stirring.

[Monomers]
Styrene 67.8 parts butyl acrylate 32.2 parts acrylic acid 1.5 parts trichlorobromomethane 1.0 part hexanediol diacrylate 0.7 parts [emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part deionized water 67.5 parts [initiator aqueous solution 1]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L-(+) ascorbic acid aqueous solution 15.5 parts [initiator aqueous solution 2]
8% L-(+) ascorbic acid aqueous solution 14.2 parts

  It cooled after completion | finish of a polymerization reaction, and milky white polymer primary particle dispersion liquid B1 was obtained. The median diameter (D50) measured using the nanotrack was 330 nm. The weight average molecular weight (Mw) was 210000. The Tg was 38 ° C.

<Preparation of Polymer Primary Particle Dispersion B2>
42.9 parts of wax dispersion A2 and 261 parts of demineralized water are charged into a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrator, and each raw material / auxiliary agent charging device, and a nitrogen stream is provided while stirring. The temperature was raised to 90 ° C. below.
Then, the mixture of the following monomers and emulsifier aqueous solution was added over 300 minutes, continuing stirring. The time at which the addition of the mixture of monomers / emulsifier aqueous solution was started was defined as polymerization start, and the following initiator aqueous solution 1 was added over 30 minutes after the start of polymerization from 270 minutes. Thereafter, the initiator aqueous solution 2 was added over 120 minutes. Thereafter, it was kept for 60 minutes while maintaining the internal temperature at 90 ° C. under stirring.

[Monomers]
Styrene 69.1 parts butyl acrylate 30.9 parts acrylic acid 1.5 parts trichlorobromomethane 1.0 part hexanediol diacrylate 0.5 parts [emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part deionized water 67.0 parts [initiator aqueous solution 1]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L-(+) ascorbic acid aqueous solution 15.5 parts [initiator aqueous solution 2]
8% L-(+) ascorbic acid aqueous solution 14.2 parts

  It cooled after completion | finish of a polymerization reaction, and milky white polymer primary particle dispersion liquid B2 was obtained. The median diameter (D50) measured using Nanotrack was 244 nm. The weight average molecular weight (Mw) was 330,000. The Tg was 36 ° C.

<Preparation of Polymer Primary Particle Dispersion B3>
Instead of 69.1 parts of styrene, 30.9 parts of butyl acrylate and 0.5 parts of hexanediol diacrylate, 65.5 parts of styrene, 34.5 parts of butyl acrylate, 0.7 parts of hexanediol diacrylate are used instead of A polymer primary particle dispersion B3 was obtained in the same manner as the polymer primary particle dispersion B2, except that the wax dispersion A3 was used instead of the wax dispersion A2.
The median diameter (D50) measured using Nanotrack was 285 nm. The weight average molecular weight (Mw) was 380000. The Tg was 37 ° C.

<Preparation of Polymer Primary Particle Dispersion B4>
Charge 2.0 parts of 20% DBS aqueous solution and 355 parts of demineralized water into a reactor equipped with a stirrer (three blades), a heating and cooling device, a concentrator, and each raw material / auxiliary agent charging device, and a nitrogen stream while stirring The temperature was raised to 90 ° C. below. When the temperature reached 90 ° C., the following pre-charged initiator aqueous solution was added.
Then, the mixture of the following monomer and emulsifier solution was added over 300 minutes, continuing stirring. The time at which the addition of the mixture of monomers / emulsifier aqueous solution was started was defined as polymerization start, and the following initiator aqueous solution 1 was added over 30 minutes after the start of polymerization from 270 minutes. Thereafter, the initiator aqueous solution 2 was added over 120 minutes. Thereafter, it was kept for 60 minutes while maintaining the internal temperature at 90 ° C. under stirring.

[Monomers]
Styrene 76.3 parts butyl acrylate 23.7 parts acrylic acid 1.5 parts trichlorobromomethane 1.0 part hexanediol diacrylate 0.7 parts [emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Deionized water 42.1 parts
8% hydrogen peroxide aqueous solution 3.2 parts 8% L-(+) ascorbic acid aqueous solution 3.2 parts
[Initiator aqueous solution 1]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L-(+) ascorbic acid aqueous solution 15.5 parts [initiator aqueous solution 2]
8% L-(+) ascorbic acid aqueous solution 14.2 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion B4. The median diameter (D50) measured using the nanotrack was 210 nm. The weight average molecular weight (Mw) was 230,000. The Tg was 62 ° C.

<Preparation of Polymer Primary Particle Dispersion B5>
36.0 parts of wax dispersion A1 and 255 parts of demineralized water are charged into a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrator, and each raw material / auxiliary agent charging device, and a nitrogen stream is provided while stirring. The temperature was raised to 90 ° C. below.
Then, the mixture of the following monomers and emulsifier aqueous solution was added over 300 minutes, continuing stirring. The time at which the addition of the mixture of monomers / emulsifier aqueous solution was started was defined as polymerization start, and the following initiator aqueous solution 1 was added over 30 minutes after the start of polymerization from 270 minutes. Thereafter, the initiator aqueous solution 2 was added over 120 minutes. Thereafter, it was kept for 60 minutes while maintaining the internal temperature at 90 ° C. under stirring.

[Monomers]
Styrene 76.8 parts butyl acrylate 23.2 parts acrylic acid 1.5 parts trichlorobromomethane 0.7 parts hexanediol diacrylate 0.7 parts [emulsifier aqueous solution]
20% DBS aqueous solution 0.8 part desalted water 66.9 parts [initiator aqueous solution 1]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L-(+) ascorbic acid aqueous solution 15.5 parts [initiator aqueous solution 2]
8% L-(+) ascorbic acid aqueous solution 14.2 parts

  It cooled after completion | finish of a polymerization reaction, and milky white polymer primary particle dispersion liquid B5 was obtained. The median diameter (D50) measured using the nanotrack was 275 nm. The weight average molecular weight (Mw) was 89,500. The Tg overlapped with the endothermic peak of the wax and could not be measured.

<Preparation of Polymer Primary Particle Dispersion B6>
Charge 2.0 parts of 20% DBS aqueous solution and 355 parts of demineralized water into a reactor equipped with a stirrer (three blades), a heating and cooling device, a concentrator, and each raw material / auxiliary agent charging device, and a nitrogen stream while stirring The temperature was raised to 90 ° C. below. When the temperature reached 90 ° C., the following pre-charged initiator aqueous solution was added.
Then, the mixture of the following monomers etc. and emulsifier aqueous solution was added over 300 minutes with continuing stirring of the said liquid there. The mixture was added dropwise over the course of 300 minutes while continuing to stir, while the mixture was added dropwise over the course of 300 minutes. The time at which the addition of this mixture of monomers and an emulsifier aqueous solution was started was taken as the polymerization start, and the following initiator aqueous solution 1 was added over 300 minutes from 0 minutes after the polymerization start, and the internal temperature was kept at 90 ° C while the stirring was continued. Hold for 60 minutes.

[Monomers]
Styrene 100.0 parts Acrylic acid 0.5 parts Trichlorobromomethane 0.5 parts [Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Deionized water 42.1 parts
8% hydrogen peroxide aqueous solution 3.2 parts 8% L-(+) ascorbic acid aqueous solution 3.2 parts
[Initiator aqueous solution 1]
8% aqueous hydrogen peroxide solution 18.9 parts 8% L-(+) ascorbic acid aqueous solution 18.9 parts

  After completion of the polymerization reaction, the reaction solution was cooled to obtain a milky white polymer primary particle dispersion B6. The median diameter (D50) measured using the nanotrack was 156 nm. The weight average molecular weight (Mw) was 66,600. The Tg was 93 ° C.

Preparation of Core Particle Dispersion C1
100 parts (solid content) of the polymer primary particle dispersion B1 is charged into a mixer equipped with a stirrer, a heating / cooling device, a concentration device, and each raw material / auxiliary agent charging device, and further, a colorant dispersion EP-700 (large) Nisshinsei Co., Ltd. product 4.4 parts (solid content) is added over 10 minutes and uniformly mixed, then 0.31 part of 0.5% aqueous solution of aluminum sulfate (solid content) is added over 15 minutes did. The temperature was further raised to 42 ° C. over 150 minutes. Here, using a multisizer, the volume median particle size (D
When v50) was measured, it was 6.7 μm. Thereafter, 4.1 parts (solid content) of a 20% aqueous DBS solution was added, and the temperature was raised to 96 ° C. over 50 minutes, held for 50 minutes, and then cooled to 30 ° C.
The obtained dispersion was withdrawn, and suction filtered with an aspirator using a filter paper of 5 types C (No. 5C manufactured by Toyo Roshi Co., Ltd.). The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), and ion-exchanged water with an electric conductivity of 1 μS / cm was added and uniformly dispersed, followed by stirring for 30 minutes. After repeating this process until the electric conductivity of the filtrate is 10 μS / cm, ion-exchanged water having an electric conductivity of 1 μS / cm is added to the cake remaining on the filter so that the dispersion concentration becomes 20%, and stirring As a result, core particle dispersion C1 was obtained.
The volume median particle size (Dv50) measured with Multisizer III is 6.8 μm,
The average circularity measured by the flow type particle analyzer was 0.970.
Further, the Tg of the core particles was 40.degree.

Preparation of Core Particle Dispersion C2
In the same manner as in the preparation of the core particle dispersion C1, 85 parts (solid content) of a polymer primary particle dispersion B2 was charged, and further 4.4 parts of a colorant dispersion EP-700 (manufactured by Dainichiseika Co., Ltd.) Solid content was added over 10 minutes and mixed uniformly, then 0.31 part (solid content) of 0.5% aqueous solution of aluminum sulfate was added over 15 minutes. The temperature was raised to an internal temperature of 40 ° C. over 120 minutes. Here, the volume median particle size (Dv 50) was measured using a Multisizer and found to be 6.5 μm. Thereafter, 15 parts (solid content) of polymer primary particle dispersion B3 was added to form a core-shell structure. The volume median particle size (Dv 50) at this time was 6.7 μm. Further, 4.1 parts (solid content) of a 20% aqueous DBS solution was added, and the temperature was raised to 96 ° C. over 50 minutes, held for 50 minutes, and then cooled to 30 ° C. Thereafter, in the same manner as in the core particle dispersion C1, a core particle dispersion C2 was obtained.
The volume median particle size (Dv50) measured with Multisizer III is 6.7 μm,
The average circularity measured by the flow type particle analyzer was 0.971.
Further, the Tg of the core particles was 39.degree.

<Preparation of Core Particle Dispersion C3>
Similar to the preparation of the core particle dispersion C2, except that 85 parts of the polymer primary particle dispersion B2 is changed to 80 parts of the polymer primary particles B2 and 15 parts of the polymer primary particles B3 to 20 parts of the polymer primary particles B1. A particle dispersion C3 was obtained.
The volume median particle size (Dv 50) measured with Multisizer III was 6.8 μm, and the average circularity measured with a flow type particle analyzer was 0.969.
Further, the Tg of the core particles was 39.degree.

<Preparation of Core Particle Dispersion C4>
A core particle dispersion C4 was obtained in the same manner as in the preparation of the core particle dispersion C1, except that the polymer primary particles B1 were changed to polymer primary particles B4, and the temperature was raised to 99 ° C. and held for 150 minutes.
The volume median particle size (Dv50) measured with Multisizer III is 6.8 μm,
The average circularity measured by the flow type particle analyzer was 0.968.
Further, the Tg of the core particles was 62 ° C.

<Preparation of Intermediate Layer Aqueous Solution D1>
480 parts of demineralized water was charged into a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrator, and each raw material / auxiliary agent charging device, and the temperature was raised to 70 ° C. under a nitrogen stream while stirring.
Thereafter, an aqueous initiator solution 1 was added, and after 5 minutes, while the stirring was continued, the following monomers and an aqueous initiator solution 2 were added over 60 minutes. Thereafter, initiator aqueous solution 3 was added over 60 minutes, and the temperature was raised to 90 ° C. simultaneously with the start of the addition. After addition of initiator aqueous solution 3, internal temperature 90 under stirring
The temperature was kept for 90 minutes.

[Monomers]
Blemmer QA (manufactured by NOF Corporation, (2-hydroxy-3-methacryloxypropyl) trimethyl ammonium chloride, 50% aqueous solution) 10.0 parts [initiator aqueous solution 1]
8.0% aqueous solution of 2,2'-azobis (2-methylpropionamidine) dihydrochloride
3.0 parts [initiator aqueous solution 2]
8.0% aqueous solution of 2,2'-azobis (2-methylpropionamidine) dihydrochloride
3.0 parts [initiator aqueous solution 3]
8.0% aqueous solution of 2,2'-azobis (2-methylpropionamidine) dihydrochloride
3.0 parts

It cooled after completion | finish of a polymerization reaction, and obtained middle class aqueous solution D1. The weight average molecular weight (Mw) was 7600.
Further, the Tg of the core particles was 39.degree.

Preparation of Shell Particle Dispersion E1
Charge 2.0 parts of 20% DBS aqueous solution and 323 parts of demineralized water into a reactor equipped with a stirrer (three blades), a heating and cooling device, a concentrator, and each raw material / auxiliary agent charging device, and a nitrogen stream while stirring The temperature was raised to 80 ° C. below.
Then, the initiator aqueous solution was added while stirring was continued, and after 5 minutes, the following mixed emulsion of monomer 1 and emulsifier solution and monomers 2 were added over 210 minutes. Thereafter, the internal temperature was maintained at 80 ° C. for 90 minutes while stirring.

[Monomers 1]
Styrene 83.5 parts butyl acrylate 16.5 parts [Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Deionized water 71.4 parts [Monomers 2]
20 parts of 20% aqueous sodium parastyrene sulfonate solution [initiator aqueous solution]
6.4 parts of a 4.0% aqueous potassium persulfate solution

  After completion of the polymerization reaction, the reaction solution was cooled to obtain a milky white shell particle dispersion E1. The median diameter (D50) measured using Nanotrack was 63 nm. The weight average molecular weight (Mw) was 242,000. The Tg was 73.degree.

<Preparation of Shell Particle Dispersion E2>
A shell particle dispersion E2 was obtained in the same manner as the shell particle dispersion E1, except that 79.0 parts of styrene and 21.0 parts of butyl acrylate were used instead of 83.5 parts of styrene and 16.5 parts of butyl acrylate. . The median diameter (D50) measured using Nanotrack was 98 nm. The weight average molecular weight (Mw) was 247,000. The Tg was 63.degree.

<Preparation of Shell Particle Dispersion E3>
Styrene 61.0 instead of 83.5 parts of styrene and 16.5 parts of butyl acrylate
A shell particle dispersion E2 was obtained in the same manner as the shell particle dispersion E1, except that 1 part and 39.0 parts of butyl acrylate were used. The median diameter (D50) measured using Nanotrack was 60 nm. The weight average molecular weight (Mw) was 232,000. The Tg was 45 ° C.
Example 1

<Production of Toner Base Particle F1>
100 parts (solid content) of the core particle dispersion C1 is charged into a reactor equipped with a stirring device and a heating and cooling device, and it is PAS-J-81 as an aqueous solution of an intermediate layer while stirring at room temperature.
(Nitto-Bo Medical 25% aqueous solution of diallyldimethyl ammonium chloride acrylamide copolymer, weight average molecular weight (Mw) 870,000) 0.07 part (solid content) was added and stirred at room temperature for 30 minutes. Then, after adding by the addition amount of 1N-NaOH aqueous solution 7.5 g / 1 L dispersion volume, 3 parts (solid content) of shell particle dispersion E1 was dripped, and it stirred at room temperature. Then, after dropping with the addition amount of 1 N HCl aqueous solution 10 g / 1 L dispersion volume, the dispersion was heated to an internal temperature of 45 ° C., held for 60 minutes, and then cooled to 20 ° C. The volume median particle size (Dv 50) measured with Multisizer III was 7.1 and the average circularity measured with a flow type particle analyzer was 0.967.

  The resulting dispersion was withdrawn and suction filtered with an aspirator using 5 type C filter paper. The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), ion-exchanged water having a conductivity of 1 μS / cm was added, and the mixture was uniformly dispersed by stirring at 50 rpm.

  This process was repeated until the electric conductivity of the filtrate became 2 μS / cm, and then the obtained cake was dried for 48 hours in a blower dryer set at 40 ° C. to obtain toner base particles F1.

<Production of Toner G1 for Development>
In a sample mill LSMK manufactured by As One Corporation, 100 parts of toner base particles F1 were added, and then 0.5 parts of silica fine particles having a volume average primary particle size of 0.03 μm were added and stirred for 2 minutes in total. Thereafter, 1.0 part of silica fine particles having a volume average primary particle diameter of 0.01 μm is added, stirred for a total of 2 minutes, mixed, and sifted to obtain a developing toner G1.
Example 2

<Production of Toner Base Particle F2>
Instead of 0.07 parts of PAS-J-81 as an interlayer aqueous solution, 0.05 parts of PAS-H-10L (Nitto-Bo Medical, diallyldimethyl ammonium chloride polymer 28% aqueous solution, weight average molecular weight (Mw) 120,000) Toner mother particles F2 were obtained in the same manner as in F1 except that (solid content) was used. The volume median particle size (Dv 50) measured with Multisizer III before washing was 7.0 μm, and the average circularity measured with a flow type particle analyzer was 0.970.

<Production of Toner G2 for Development>
A developing toner G2 was obtained by the same method as G1 except that F2 was used instead of F1.
[Example 3]

<Production of Toner Base Particle F3>
Toner base particles F3 were obtained in the same manner as in F1 except that the shell particle dispersion E2 was used instead of the shell particle dispersion E1. The volume median particle size (Dv50) measured with Multisizer III before washing was 7.1 μm, and the average circularity measured with a flow type particle analyzer was 0.970.

<Production of Toner G3 for Development>
A developing toner G3 was obtained in the same manner as the developing toner G1 except that F3 was used instead of F1.
Example 4

<Production of Toner Base Particle F4>
Instead of the shell particle dispersion E1, a styrene / acrylic acid 2-ethylhexyl / 2-acrylamido-2-methylpropane sulfonic acid copolymer dispersion (containing 2.7% by weight of 2-acrylamido-2-methylpropane sulfonic acid, weight average) Molecular weight (Mw): 14,200, Tg: 70 ° C., median diameter (D50) measured using Nanotrac: 24 nm, solid content concentration: 20% by weight, except using 3.5 parts (solid content) Toner mother particles F4 were obtained in the same manner as in F1. The volume median particle size (Dv50) measured with Multisizer III before cleaning is 7.2
The average circularity measured by the flow type particle analyzer was 0.968.

<Production of Toner G4 for Development>
A developing toner G4 was obtained by the same method as G1 except that F4 was used instead of F1.
[Example 5]

<Production of Toner Base Particle F5>
Toner base particles F5 were obtained in the same manner as the toner base particles F4, except that the core particle dispersion C2 was used instead of the core particle dispersion C1. The volume median particle size (Dv50) measured with Multisizer III before washing was 7.1 μm, and the average circularity measured with a flow type particle analyzer was 0.970.

<Production of Toner G5 for Development>
A developing toner G5 was obtained by the same method as G1 except that F5 was used instead of F1.
[Example 6]

<Production of Toner Base Particle F6>
Toner base particles F5 were obtained in the same manner as the toner base particles F4, except that the core particle dispersion C3 was used instead of the core particle dispersion C1. The volume median particle size (Dv 50) measured with Multisizer III before washing was 6.9 μm, and the average circularity measured with a flow type particle analyzer was 0.967.

<Production of Toner G6 for Development>
A developing toner G6 was obtained by the same method as G1 except that F6 was used instead of F1.

Comparative Example 1
<Production of Toner Base Particle F7>
Toner base particles F7 were obtained in the same manner as in F1 except that 0.15 parts (solid content) of Blemmer QA was used instead of 0.07 parts of the aqueous solution of the intermediate layer PAS-J-81. The volume median particle size (Dv 50) measured with Multisizer III before washing was 11.0 μm.

<Production of Toner G7 for Development>
A developing toner G7 was obtained by the same method as G1 except that F7 was used instead of F1.

Comparative Example 2
<Production of Toner Base Particle F8>
Toner mother particles F8 are obtained by the same method as F2 except that 3.0 parts (solid content) of AERODISP W440 (manufactured by Nippon Aerosil, 40% alumina aqueous dispersion) is used instead of 0.15 parts of the intermediate layer aqueous solution D1. The The volume median particle size (Dv 50) of F9 before washing was measured using Multisizer III, and it was 6.9 μm, and the average circularity measured by a flow type particle analyzer was 0.951.

<Production of Toner G8 for Development>
A developing toner G8 was obtained in the same manner as the developing toner G1 except that F8 was used instead of F1.

Comparative Example 3
<Production of Toner Base Particle F9>
Toner base particles F9 were obtained in the same manner as in F1 except that 0.15 part of the interlayer aqueous solution D1 was used instead of 0.07 parts of the interlayer aqueous solution PAS-J-81.
The volume median particle size (Dv50) of F9 before cleaning was measured using Multisizer III was 7.4
It was μm, and the average circularity measured by a flow type particle analyzer was 0.971.

<Production of Toner G9 for Development>
A developing toner G9 was obtained by the same method as G1 except that F9 was used instead of F1.

Comparative Example 4
<Production of Toner Base Particle F10>
Toner mother particles F10 were obtained in the same manner as in F1, except that the shell particle dispersion E3 was used instead of the shell particle dispersion E1. The volume median particle size (Dv 50) was measured with a Multisizer III and the F10 before washing was 7.4 μm, and the average circularity measured with a flow type particle analyzer was 0.966.

<Production of Toner G10 for Development>
A developing toner G10 was obtained by the same method as G1 except that F10 was used instead of F1.

Comparative Example 5
<Production of Toner Base Particle F11>
Toner base particles F11 were obtained in the same manner as F4, except that core particle dispersion C4 was used instead of core particle dispersion C1. The volume median particle size (Dv 50) of F11 before washing was measured using Multisizer III was 7.3 μm, and the average circularity measured by a flow type particle analyzer was 0.967.

<Production of Toner G11 for Development>
A developing toner G11 was obtained by the same method as G1 except that F11 was used instead of F1.

Comparative Example 6
<Production of Toner Base Particle F12>
Toner mother particles F12 were obtained in the same manner as F4, except that the intermediate layer aqueous solution was not used. In F12, it was assumed that the washing filtrate was cloudy and that shell particles were not attached.

<Production of Toner G12 for Development>
A developing toner G12 was obtained by the same method as G1 except that F12 was used instead of F1.

Comparative Example 7
<Production of Toner Base Particle F13>
Toner mother particles F13 were obtained by the same method as F11 except that the shell particle dispersion E3 was used. The volume median particle size (Dv50) of F13 before cleaning was measured using Multisizer III is 7
. The average circularity measured by the flow type particle analyzer was 0.966.

<Production of Toner G13 for Development>
A developing toner G13 was obtained by the same method as G1 except that F13 was used instead of F1.

Comparative Example 8
<Production of Toner Base Particle F14>
<Preparation of Core Particle Dispersion C5>
In the same manner as in the preparation of the core particle dispersion C1, 90 parts (solid content) of the polymer primary particle dispersion B5 was charged and uniformly mixed, and then 0.12 parts of a 5% aqueous solution of iron sulfate and FeSO ₄ was added over 1 minute Then, 4.9 parts (solid content) of a colorant dispersion EP-700 (manufactured by Dainichiseika Co., Ltd.) was added over 10 minutes and uniformly mixed. Thereafter, 0.1 part (solid content) of a 0.5% aqueous solution of aluminum sulfate was added over 30 minutes. The temperature was further raised to 54 ° C. over 120 minutes. Here, the volume median particle size (Dv 50) was measured using a Multisizer and found to be 6.6 μm. Thereafter, 10 parts (solid content) of polymer primary particle dispersion B6 was added to form a core-shell structure. The volume median particle size (Dv 50) at this time was 6.9 μm. Further, 6 parts (solid content) of a 20% aqueous DBS solution was added, and the temperature was raised to 97 ° C. over 120 minutes, held for 150 minutes, and then cooled to 30 ° C. The volume median particle size (Dv 50) measured with Multisizer III before washing was 6.9 μm, and the average circularity measured with a flow type particle analyzer was 0.968.
In addition, Tg overlapped with the endothermic peak of the wax and could not be measured.

  The resulting dispersion was withdrawn and suction filtered with an aspirator using 5 type C filter paper. The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), ion-exchanged water having a conductivity of 1 μS / cm was added, and the mixture was uniformly dispersed by stirring at 50 rpm.

  This process was repeated until the electric conductivity of the filtrate became 2 μS / cm, and then the obtained cake was dried for 48 hours in a blower dryer set at 40 ° C., to obtain toner base particles F14.

  The developing toners obtained in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Table 1.

<Blocking resistance>
10 g of developing toner is placed in a cylindrical container with an inner diameter of 3 cm and a height of 6 cm, a load of 20 g is applied, and it is left under an environment of 50 ° C. and 55% humidity for 48 hours. The degree of aggregation was confirmed by applying a load.
○ (Good): Collapse under a load of less than 100 g.
Δ (practical use): Collapse under a load of less than 300 g.
X (unusable): Aggregated and can not collapse unless a load of 300 g or more is applied.

<Fixing temperature range test>
The fixing device has a roller diameter of 34 mm, a nip width of 7 mm, and a fixing speed of 195 mm / sec. The upper roller has a heater and the roller surface is made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). Silicone oil is not applied. Prepare a recording paper (excellent white manufactured by Oki Data Co., Ltd.) carrying an unfixed toner image with a toner adhesion amount of about 0.5 mg / cm ² using a printer modification machine for negatively charged toner, and use a heating roller The surface temperature was changed from 120 ° C. to 210 ° C. in steps of 5 ° C., conveyed to the fixing nip portion, and the fixing state when discharged at a speed of 195 mm / sec was observed. A temperature range in which toner offset or sheet winding did not occur on the heating roller during fixing and the toner on the recording sheet after fixing was sufficiently adhered to the recording sheet was determined as the fixing temperature range ΔT as follows.

50 ° C ≦ ΔT
40 40 ° C Δ ΔT <50 ° C
× ΔT <40 ° C

<Measurement method and definition of low temperature fixability>
In the above measurement method, the actual copying test is performed with the roller temperature set at 140 ° C., the fixed image obtained is rubbed under a constant load, and the density decrease before and after rubbing is visually compared, and the following criteria "Low-temperature fixability" was determined.
良好 (Good): No concentration decrease ○ (Good for practical use): A slight decrease in concentration is seen Δ (Insufficient): A marked decrease in concentration is noticeable × (Not available): Almost peeled off

<Evaluation of chargeability>
Using FM-U65 manufactured by Kanto Denka Kogyo Co., Ltd. as a carrier, 10 g of a mixture of weight ratio 1:24 with the carrier is placed in a glass sample bottle with a volume of 30 ml, and a vibration frequency of 600 rpm with a mixer mill made by Mitamura Riken. The sample was shaken for 1 minute, and 0.1 g of this was used to measure the charge amount (Q / M) by a suction blow-off method using a blow-off charge amount measuring apparatus manufactured by Toshiba Chemical Co., Ltd.
Blow condition: 0.05 kg / cm ³ × 3 seconds
Suction pressure: 350 to 400 mm H ₂ O
Screen: 400 mesh
○ (Good): -10 μC / g Q Q / M <-30 μC / g
((Practical): -5 μC / g ≦ Q / M <-10 μC / g
X (not usable): less than -5 μC / g or positively charged

In Comparative Example 1, when the toner base particle surface was observed with a scanning electron microscope, only a small amount of adhesion of shell particles was observed. Since a monomer was used as an intermediate layer component, it is considered that an intermediate layer was not formed on the surface of the core, and therefore no shell particles were attached. Because no shell was formed, the blocking resistance was insufficient. In addition, since the charge amount was positively charged, an image could not be output for a fixing test.
In Comparative Example 2, the blocking resistance was good but the fixability was insufficient. The reason for this is that the formation of the intermediate layer with fine particles causes the intermediate layer to be thick, and the ratio of the total of the intermediate layer and the shell layer in the entire toner increases, so it is thought that the low temperature fixability is impaired. Be It is inferred that when the ratio of the intermediate layer is further increased, it is difficult to obtain low temperature fixability. Similarly, in the shell layer, it can be inferred that low temperature fixability becomes difficult to obtain if the ratio is increased.
In Comparative Example 6, when the toner base particle surface was observed with a scanning electron microscope, almost no shell particles were attached.

Claims (6)

An intermediate layer having a polarity opposite to that of the core particle is present on the surface of the core particle containing the binder resin, the colorant, and the wax, and the surface of the intermediate layer has a polarity opposite to that of the intermediate layer, and at least the binder resin It is a negatively charged toner for electrostatic image development in which shell particles containing the toner adhere and a shell layer is formed,
The intermediate layer contains a water-soluble cationic resin, and the water-soluble cationic resin has the following repeating structure (A
Negatively charged toner for developing electrostatic images which is characterized by containing a).

[Oite the above repeating structure (A), R ¹ and R ² are each independently a hydrogen atom, or a number of 1 to 6 linear carbon atoms, a branched or cyclic alkyl group, X
^- is a halogen ion or sulfonate ion or alkylbenzene sulfonate ion. ] The water-soluble cationic resin further comprises the following repeating structure (C):
The negatively charged toner for electrostatic image development according to claim 1.

Assuming that the glass transition point of core particles is Tg1, and the glass transition point of shell particles is Tg2,
25 ° C ≦ Tg1 ≦ 55 ° C
55 ° C ≦ Tg2
Tg2-Tg1 ≧ 10 ° C.
The negatively charged toner for electrostatic image development according to claim 1 or 2 , 1 to claim shell particles, characterized in that it contains a sulfonic acid or sulfonic acid salt
The negatively charged toner for electrostatic image development according to any one of 3 . Negatively charged toner according to any one of claims 1乃optimum 4, characterized in that it contains an ester wax. The negatively charged toner for electrostatic charge image development according to claim 5 , wherein the ester wax is represented by the following structural formula (1).

[In formula (1), R ³ is a divalent to octavalent neopentyl polyol residue, and R ⁴ is a carbon number of 13 to 25]
Straight-chain alkyl group, and p is an integer of 2-8. ]