JP2005352128A - Electrostatic charge image developing full color toner and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrostatic charge image developing full color toner which has excellent moisture absorption resistance while attaining a sufficient image density, and retains good charging property over a prolonged period of time, and to provide a method for manufacturing the same. <P>SOLUTION: The electrostatic charge image developing full color toner includes toner particles obtained by flocculating/fusing at least fine binder resin particles and a colorant in an aqueous medium, an acid value of the toner is ≤10 mg KOH/g, and a transmission density (TD) of an image in the case of a toner coating weight of 4 g/m<SP>2</SP>is ≥1.2 in the case of black toner and ≥0.9 in the case of cyan toner, magenta toner and yellow toner. In the method for manufacturing the electrostatic charge image developing full color toner in which at least a fine binder resin particle dispersion and a colorant dispersion are mixed and those particles are flocculated/fused to form toner particles, an anionic surfactant A is contained in the colorant dispersion and an anionic surfactant B whose valence is different from that of the anionic surfactant A is contained in a mixed dispersion system in the flocculation/fusion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a full-color toner for developing electrostatic images and a method for producing the same.

  At present, toners containing toner particles obtained by agglomerating / fusing resin fine particles and colorants such as carbon black particles in an aqueous medium have already been put on the market, but have the following drawbacks.

Resin fine particles, which are organic components, and colorants, particularly carbon black classified as inorganic pigments, have different aggregation rates when they are aggregated due to a difference in hydrophilicity in an aqueous system. For this reason, the colorant particles having relatively high hydrophilicity are aggregated in the initial stage of the aggregation process, resulting in poor dispersion of the colorant in the toner, causing problems such as poor charging and insufficient density. For example, in a uniform black solid image with a toner adhesion amount of 4 g / m ² , it is difficult to ensure a transmission density (TD) of about 1.2 or more, and the toner consumption increases. Even if the content is increased, it is difficult to improve the lack of concentration because the colorant is not effectively dispersed and contained. In addition, the problem of poor charging and accompanying transfer failure is particularly noticeable in high humidity environment conditions (relative humidity of 70% or more), and also during printing durability. These problems can be solved to some extent by using a monomer composition that increases the hydrophilicity on the resin fine particle side. For example, in a styrene acrylic copolymer composition that can be produced by an emulsion polymerization method, the hydrophilicity of the resin is increased by increasing the amount of acid components such as acrylic acid and methacrylic acid, and the aggregation balance with the colorant particles is improved. Colorant dispersibility can be improved.

  However, another problem occurs in the toner using resin fine particles with an increased amount of such an acid component. The problem is the problem of moisture absorption resistance accompanying the increase in the hydrophilicity of the toner particles. For example, when the total monomer composition of the resin fine particles contains 5% or more of an acid component, the obtained toner has a high temperature and high humidity. It has been found that the moisture content can reach 2% in the environment. Such a toner is not preferable because of problems such as an increase in the environmental fluctuation of the charge amount and an environmental fluctuation in the melting characteristics of the toner. In particular, the problem of toner scattering and fogging due to poor charging and poor transfer at the time of printing in a high temperature and high humidity environment are remarkable.

  Moreover, in order to improve the dispersibility of the colorant particles in the dispersion, a method of adding a monovalent anionic surfactant is known and common (for example, Patent Document 1). The initial aggregation of the colorant cannot be sufficiently prevented.

Further, as a means for controlling the aggregation speed of the resin fine particles and the colorant particles during the production of the toner particles, a means for adding a surfactant to the aggregation reaction system is generally used (for example, Patent Document 2). ). In this case, a method of adding a cationic surfactant or a monovalent anionic surfactant is known and common, but in this case as well, the above-described initial aggregation of the colorant cannot be sufficiently prevented.
Therefore, in the toner of such a manufacturing method, it is the actual situation that either the dispersibility (image density) of the colorant or the moisture absorption resistance of the toner must be sacrificed.
JP 2002-351142 A JP 2001-117263 A

  An object of the present invention is to provide a full-color toner for developing an electrostatic image that has excellent moisture absorption resistance while achieving a sufficient image density and maintains good chargeability over a long period of time, and a method for producing the same. .

The present invention comprises toner particles obtained by aggregating / fusing at least binder resin fine particles and a colorant in an aqueous medium, the toner has an acid value of 10 mg · KOH / g or less, and a toner adhesion amount of 4 g / The present invention relates to a full-color toner for developing an electrostatic charge image, wherein the image transmission density (TD) at m ² is 1.2 or more for black toner and 0.9 or more for cyan toner, magenta toner and yellow toner.

  The present invention is also a method for producing a full-color toner for developing an electrostatic image, wherein at least a binder resin fine particle dispersion and a colorant dispersion are mixed, and the particles are aggregated / fused to form toner particles. An anionic surfactant A is contained in the colorant dispersion, and an anionic surfactant B having a valence different from that of the anionic surfactant A is contained in the mixed dispersion system at the time of aggregation / fusion. The present invention relates to a method for producing a full-color toner for electrostatic charge image development.

  The toner of the present invention has excellent moisture absorption resistance while achieving a sufficient image density, and can maintain good chargeability over a long period of time.

  The full-color toner for developing an electrostatic image of the present invention has a small amount of acidic functional groups on the surface of the toner particles, and the acid value of the whole toner is 10 mg · KOH / g or less, preferably 1 to 9 mg · KOH / g. Therefore, the moisture content in a high-temperature and high-humidity (temperature 30 ° C., humidity 80%) environment is 1.5% or less, and particularly excellent moisture absorption resistance of 0.2 to 1.5%. If the acid value is too large, the moisture absorption resistance is lowered, so that the toner charge amount fluctuates with environmental fluctuations and fogging occurs.

The acid value is a value measured by the following method. However, it does not have to be measured by the following method, and may be measured by any method as long as the acid value of the entire toner can be measured.
(Measuring method)
Dissolve 10 mg of sample in 50 ml of toluene and remove the colorant with a 0.1 μm membrane filter. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titrated with a standardized N / 10 potassium hydroxide / alcohol solution and calculated from the consumption of N / 10 potassium hydroxide / alcohol solution. is there.

Further, since the dispersibility of the colorant in the toner particles is excellent, the toner image density becomes very high. That is, even with a relatively small amount of uniform solid image with a toner adhesion amount of 4 g / m ² , a relatively high transmission density (TD) is ensured. It is preferably 1.4 or more, and 0.9 or more, preferably 1.0 or more for cyan toner, magenta toner, and yellow toner. If the image density is too low, it is necessary to set a large amount of toner adhesion on the paper in order to obtain a desired image density, which increases the toner consumption and increases the printing cost. In particular, when forming a color image in which toner layers of a plurality of colors are superimposed, the thickness of the image is increased, so that transfer efficiency is remarkably reduced, and the secondary color and the tertiary color when toners are superimposed are displayed. The character's hollowed out and scattered performance deteriorates.

  In the present invention, the transmission density is determined by transmitting natural light to an image formed on plain paper (Konica Minolta; CF paper) and transmitting light having a specific wavelength in the transmitted light using a Macbeth transmission densitometer (TD-904; manufactured by Macbeth). ) Is used. The light of a specific wavelength to be measured is different for each toner color. For example, a white filter wheel is selected for black toner, a red filter wheel is selected for cyan toner, and a magenta toner is selected. In this case, the green filter wheel is selected, and in the case of yellow toner, the blue filter wheel is selected to measure the transmission density. The transmission density does not have to be measured by the above densitometer, but may be measured by any device as long as it follows the same principle and principle as the above densitometer.

The transmission density when the toner adhesion amount is 4 g / m ² can be easily calculated from the relationship between the toner adhesion amount and the transmission density in each image by forming multiple uniform solid images with arbitrarily different toner adhesion amounts. is there. The toner adhesion amount and the transmission density have a linear function relationship up to about 1.4 for black toner, and about 1.0 for cyan, magenta, and yellow toners when the toner of the present invention with good pigment dispersion is used. It is.

  Since the toner of the present invention is excellent in moisture absorption resistance and colorant dispersibility as described above, good chargeability can be maintained over a long period of time. If the moisture absorption resistance is poor, the toner absorbs moisture, and thus good chargeability cannot be maintained. If the colorant dispersibility is poor, the ratio of exposure of the colorant to the toner particle surface increases, and the chargeability decreases.

  In the so-called emulsion polymerization aggregation method, the toner of the present invention can be used as a surfactant contained in a colorant dispersion and a surfactant contained in a mixed dispersion system during aggregation / fusion. It can be manufactured by using an activator. By using such a surfactant in combination, a toner having good dispersibility of the colorant, particularly carbon black, can be produced even if the amount of the acid monomer component constituting the resin fine particles is reduced.

Specifically, the toner of the present invention can be produced by, for example, the following method;
(1) A process for producing and preparing a dispersion (polymer latex) of binder resin fine particles (resin fine particles),
(2) a step of aggregating / fusing at least resin fine particles and a colorant in an aqueous medium to obtain toner particles;
(3) A filtration / washing process in which the toner particles are filtered off from the toner particle dispersion (aqueous medium) and the surfactant is removed from the toner particles.
(4) A drying step of drying the washed toner particles, and (5) a step of adding and mixing an external additive to the dried toner particles.
Hereinafter, each step will be described in detail.

(1) a step of preparing a dispersion of resin fine particles;
By the emulsion polymerization method, a dispersion of resin particles having a uniform and small particle diameter can be obtained. As an example of the polymerization method, a radical polymerization initiator is dissolved in an aqueous medium and heated, and when it reaches a predetermined temperature (polymerization temperature), polymerization including a radical polymerizable monomer (monomer mixture) is performed. The composition is dispersed in oil droplets and the system is heated with stirring, usually under a nitrogen atmosphere. The weight average molecular weight of the resin fine particles is desirably 5,000 to 100,000, particularly 8,000 to 50,000. The molecular weight of the resin fine particles can be adjusted by the amount of the polymerization initiator, the reaction temperature, and the addition amount of the chain transfer agent. When a chain transfer agent is used to adjust the molecular weight of the resin fine particles, it is preferable to add the chain transfer agent mixed with a radical polymerizable monomer. The polymerization temperature and the polymerization time can be appropriately set within the range where the polymerization reaction occurs. The particle diameter of the resin fine particles thus obtained is preferably in the range of 50 to 500 nm in terms of weight average particle diameter.

  The resin fine particles preferably have a molecular weight distribution of two or more peaks. As a suitable method for producing such resin fine particles, resin fine particles are prepared according to a conventional method such as an emulsion polymerization method, and a polymerization composition is added to and dispersed in the dispersion liquid of the resin fine particles. The method of carrying out multilayering (compositing) by performing multistage emulsion polymerization to perform can be mentioned. Even when the resin fine particles have a molecular weight distribution of two or more peaks, the weight average molecular weight of the resin fine particles is preferably within the above range.

  As the weight average molecular weight, a value measured by the following method in GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a solvent is used. However, it does not have to be measured by the following method, and may be measured by any method as long as it can be measured according to the same principle and principle as the following method.

  As a method for measuring the molecular weight of a resin by GPC, 1 cc of THF is added to 0.5 to 5.0 mg (specifically 1 mg) of a measurement sample, and the mixture is sufficiently dissolved by stirring with a magnetic stirrer at room temperature. Next, after processing with a membrane filter having a pore size of 0.45 to 0.50 μm, it is injected into GPC. As GPC measurement conditions, the column is stabilized at 40 ° C., THF is allowed to flow at a flow rate of 0.35 cc / min, and about 10 μl of a sample having a concentration of 1 mg / cc is injected for measurement. The column is preferably used in combination with a commercially available polystyrene gel column. For example, combinations of TSKge1 Super HZ1000, HZ2000, HZ2500, HZ3000, HZ4000, HZM-N, HZM-M, HZM-H, TSKguardcolumn SuperHZ-L, and HZ-H manufactured by Tosoh Corporation may be mentioned. Further, it is preferable to use a refractive index detector or a UV detector as the detector. In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. It is recommended to use about 10 points as polystyrene for calibration curve measurement.

  In the present invention, a seed that undergoes emulsion polymerization by forming droplets of a polymerization composition containing a polymerizable monomer in the presence of other toner component particles such as wax and charge control agent previously emulsified and dispersed in an aqueous medium. Emulsion polymerization may be performed to obtain resin fine particles, or other toner components such as wax and charge control agent may be contained in the polymerization composition, and the polymer composition may be used to obtain resin fine particles. . Further, when the emulsion polymerization is performed in multiple stages, particularly in three stages, it is preferable to contain a wax in the intermediate layer.

  The polymerizable monomer constitutes the binder resin in the toner particles, and is not particularly limited as long as it is a monomer having radical polymerizability. Examples of such a polymerizable monomer include a carboxyl group-containing monomer and a carboxyl group-free monomer. In the present invention, from the viewpoint of achieving the toner acid value and improving the moisture absorption resistance, the amount of the carboxyl group-containing monomer used is 5% by weight or less based on the total polymerizable monomers constituting the resin fine particles, In particular, 3% by weight or less is preferable. When the resin fine particles have a multi-layered structure, the amount of the carboxyl group-containing monomer used with respect to all the polymerizable monomers constituting the outermost layer of the resin fine particles may be within the above range. In this case, the amount of the carboxyl group-containing monomer used for the total polymerizable monomer constituting the core particle (core material) and the amount of the carboxyl group-containing monomer used for the total polymerizable monomer constituting the intermediate layer are They are usually 0 to 10% by weight and 0 to 10% by weight, respectively. Moreover, when using 2 or more types of resin microparticles | fine-particles, the carboxyl group-containing monomer usage-amount with respect to all the polymerizable monomers in all the resin microparticles used should just be in the said range.

  The carboxyl group-containing monomer is not particularly limited as long as it has the group and has radical polymerizability, and a conventionally known monomer can be used. In addition, one or a combination of two or more can be used so as to satisfy the required characteristics. Specific examples include (meth) acrylic acid, itaconic acid, itaconic acid monobutyl ester, maleic acid, maleic acid monomethyl ester, maleic acid monobutyl ester, and the like.

  The carboxyl group-free monomer is not particularly limited as long as it has no such group and has radical polymerizability, and conventionally known monomers can be used. In addition, one or a combination of two or more can be used so as to satisfy the required characteristics. For example, vinyl aromatic monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogenated Olefin monomers and the like can be used.

  Specific examples of the vinyl aromatic monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-ethylstyrene, and p-n. -Butyl styrene, p-isobutyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene P-2-ethylhexyl styrene, 2,4-dimethyl styrene, p-chloro styrene, 3,4-dichloro styrene, α-methyl styrene, p-styrene sulfonate, 2-vinyl pyridine, 4-vinyl pyridine, etc. Aromatic monomers and derivatives thereof are mentioned.

  Specific examples of (meth) acrylic acid ester monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic Acid butyl, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid-2-ethylhexyl (meth) acrylate phenyl, (meth) acrylate cyclohexyl, ( Examples include dimethylaminoethyl methacrylate, diethylaminoethyl (meth) acrylate, ethyl β-hydroxyacrylate, and propyl γ-aminoacrylate.

Specific examples of vinyl ester monomers include vinyl acetate, vinyl propionate, vinyl benzoate, and the like.
Specific examples of vinyl ether monomers include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether, and the like.
Specific examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.
Specific examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

  The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble. For example, persulfates (for example, potassium persulfate, ammonium persulfate, etc.), azo compounds (for example, 4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) Salt), peroxide compounds (hydrogen peroxide, etc.) and the like. Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator.

A known chain transfer agent can be added to the polymerization composition for the purpose of adjusting the molecular weight.
The chain transfer agent is not particularly limited. Thioglycolate such as butyl thioglycolate, t-butyl thioglycolate, -2-ethylhexyl thioglycolate, octyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, 3-mercaptopropionic acid, 3-mercapto Ethyl propionate, propyl 3-mercaptopropionate, butyl 3-mercaptopropionate, t-butyl 3-mercaptopropionate, 3-ethylhexyl 3-mercaptopropionate, 3-me Mercaptopropionate such as octyl captopropionate, decyl 3-mercaptopropionate, octyl 2-methyl-3-mercaptopropionate, ethylene glycol bis (thioglycolate), t, 4-butanediol bis (3-mercaptopro Pionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetra (3-mercaptopropionate) and other polythiols, α-methylstyrene dimer, α-terpinene, terpinolene, etc. Examples include hydrocarbon compounds, halogenated carbons such as carbon tetrabromide and carbon tetrachloride. Of these, alkyl mercaptans are preferably used from the viewpoints of molecular weight controllability, consideration for recycling, environmental stability, decomposition stability during production and fixing, economy, odor, and the like.

The aqueous medium usually contains a surfactant. The surfactant that can be used in this case is not particularly limited, and the following ionic surfactants can be given as examples of suitable compounds.
Examples of the ionic surfactant include sulfonate (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfone diphenylurea-4,4-diazo-bis-amino-8-naphthol- 6-sulfonate sodium, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonate sodium, etc.) , Sulfate salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, me Calcium phosphate and the like).

  The content of the surfactant in the aqueous medium is not particularly limited, but is usually 0.01 to 3.0% by weight, preferably 0.1 to 1.0% by weight, more preferably 0.2 to 0.6% by weight in the resin fine particle dispersion. % Content.

(2) a step of agglomerating / fusing at least resin fine particles and a colorant in an aqueous medium to obtain toner particles;
In this step, at least the resin fine particle dispersion and the colorant dispersion obtained in the above step and, if desired, a dispersion of other toner component particles such as wax and charge control agent are mixed, and these particles are agglomerated / fused. To form toner particles.

In this specification, “aggregation” is used based on the concept that at least a plurality of resin fine particles are simply attached. By “aggregation”, so-called hetero-aggregated particles (groups) are formed in which the constituent particles are in contact with each other, but no bonding due to melting of resin fine particles or the like is formed. A group of particles formed by such “aggregation” is referred to as “aggregated particles”.
“Fusion” is a concept that is intended to form a bond as a unit of use and handling by forming a bond due to melting of resin fine particles, etc., at least at a part of the interface of each constituent particle in the aggregated particles. And The particle group that has undergone such “fusion” is referred to as “fused particles”.
“Aggregation / fusion” refers to an action in which aggregation and fusion occur simultaneously or in stages, or an action in which aggregation and fusion occur simultaneously or in stages.

  The colorant dispersion is obtained by dispersing a colorant in an aqueous medium. In the present invention, the colorant dispersion contains an anionic surfactant A, and an anionic surfactant B having a valence different from that of the anionic surfactant A in the mixed dispersion system during aggregation / fusion. Is contained. That is, the mixed dispersion system at the time of aggregation / fusion includes not only the anionic surfactant A contained in the colorant dispersion contained in the mixed dispersion system, but also the anionic surfactant A and the valence. Anionic surfactants B with different levels are present. Therefore, even if the amount of the acid monomer component constituting the resin fine particles is reduced, initial aggregation of the colorant, particularly carbon black, can be effectively prevented, and toner particles excellent in colorant dispersibility can be obtained. Although the details of the mechanism are not clear, it is thought to be based on the following mechanism. When at least two types of anionic surfactants A and B having different valences are present at the time of aggregation / fusion, both the resin fine particles and the colorant particles are effectively stabilized, and their aggregation speed is appropriately approximated. As a result, it is considered that one of the resin fine particles and the colorant particles, particularly the colorant particles are preferentially aggregated, is avoided, and the colorant is effectively dispersed in the toner particles. If only one of the anionic surfactants A or B is contained in the mixed dispersion system, the colorant is not effectively dispersed at the time of agglomeration and fusion, and not only the desired image density can be achieved, but also the charging property is uniform. descend. For example, when a monovalent anionic surfactant is contained in the colorant dispersion and the same surfactant is newly added to the mixed dispersion, or nothing is added to the mixed dispersion. When only a monovalent anionic surfactant is contained, the resin fine particles are excessively stabilized and preferential aggregation of the colorant particles occurs, and the dispersibility of the colorant is deteriorated at the time of aggregation / fusion. Further, for example, when the divalent anionic surfactant is contained in the colorant dispersion and the same surfactant is newly added to the mixed dispersion, or nothing is added, the mixed dispersion is used. When the resin contains only a divalent anionic surfactant, the resin fine particles are hardly stabilized, so that the aggregation speed of the resin fine particles and the colorant particles cannot be appropriately approximated. In addition to the deterioration of the incorporation into the resin, aggregation of the resin particles occurs, resulting in a decrease in dispersibility.

  Examples of the anionic surfactant A contained in the colorant dispersion include monovalent and divalent anionic surfactants, and usually one of the monovalent or divalent anionic surfactants. The divalent anionic surfactant is preferably used alone.

  As the monovalent anionic surfactant, for example, monosulfonate, monosulfate, monocarboxylate, monophosphate, and the like can be used.

（式中、R^４およびR^５はそれぞれ独立して炭素数4〜16、好ましくは6〜12の１価脂肪族飽和炭化水素基である；M^ｎ＋およびｎは前記と同様である）で表されるジアルキルサクシネートモノスルホン酸塩、ならびに
3，3−ジスルホンジフェニル尿素−4，4−ジアゾ−ビス−アミノ−8−ナフトール−6−スルホン酸ナトリウム、オルト−カルボキシベンゼン−アゾ−ジメチルアニリン、2，2，5，5−テトラメチル−トリフェニルメタン−4，4−ジアゾ−ビス−β−ナフトール−6−スルホン酸ナトリウム等の他のモノスルホン酸塩が挙げられる。 As the monosulfonate, for example, for example,
_{^{Formula; (R 1 -Ar 1 -SO 3}} ) - n · M n + (I)
Wherein R ¹ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms, preferably 10 to 14 carbon atoms; Ar ¹ is a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms, preferably 6 carbon atoms. M ^{n +} is a monovalent or divalent metal ion or ammonium ion, and examples of the metal ion include sodium ion, potassium ion, and calcium ion; n is the valence of the metal ion or ammonium ion And is an alkylaryl monosulfonate represented by 1 or 2,
Arylalkyl polyether monosulfonates,
General formula;

Wherein R ⁴ and R ⁵ are each independently a monovalent aliphatic saturated hydrocarbon group having 4 to 16 carbon atoms, preferably 6 to 12 carbon atoms; M ^{n +} and n are as defined above. Dialkyl succinate monosulfonates, and
3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate sodium, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-tri Other monosulfonates such as phenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonate.

Preferable specific examples of the alkylaryl monosulfonate include sodium dodecylbenzenesulfonate.
Preferable specific examples of the arylalkyl polyether monosulfonate include Triton X-200 available from Rohm & Haas.
Specific examples of preferable dialkyl succinate monosulfonate include sodium dioctyl sulfosuccinate.

As the monosulfate ester salt, in detail, for example,
_{^{Formula; (R 6 -O-SO 3}} ) - n · M n + (III)
(Wherein R ⁶ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms, preferably 8 to 16 carbon atoms; M ^{n +} and n are as defined above) Is mentioned.

  Preferable specific examples of the alkyl monosulfate ester salt include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate and the like.

For example, as a monocarboxylate,
_{^{Formula; (R 7 -COO) - n}} · M n + (IV)
Wherein R ⁷ is a saturated or unsaturated monovalent aliphatic hydrocarbon group having 3 to 20 carbon atoms, preferably 5 to 17 carbon atoms; M ^{n +} and n are as defined above. Is mentioned.

  Specific examples of the fatty acid salt include sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate and the like.

  Preferred monovalent anionic surfactants are monosulfate esters, especially alkyl monosulfate esters.

  As the divalent anionic surfactant, for example, disulfonate can be used.

As the disulfonate, in detail, for example,
General formula;

または

Or

(In the formulas (V) and (VI), R ¹⁰ is a divalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms, preferably 8 to 16; X ⁺ is a monovalent metal ion or ammonium ion. And examples of the metal ion include sodium ions and potassium ions; Y ²⁺ is a divalent metal ion such as calcium ions),
General formula;

または

Or

(In Formula (VII) and Formula (VIII), R ¹¹ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms, preferably 10 to 14 carbon atoms; X ⁺ and Y ²⁺ are the same as above) An alkyl diphenyl ether disulfonate represented by the general formula:

または

Or

(In Formula (IX) and Formula (X), R ¹² and R ¹³ are each independently a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms, preferably 10 to 14 carbon atoms; X ⁺ and Y ²⁺ Is the same as described above), and dialkyl succinate disulfonate.

Preferred divalent anionic surfactants are disulfonates, especially alkyl diphenyl ether disulfonates.
Preferable specific examples of the alkyl diphenyl ether disulfonate include disodium dodecyl diphenyl ether disulfonate, dipotassium dodecyl diphenyl ether disulfonate, diammonium dodecyl diphenyl ether disulfonate, calcium dodecyl diphenyl ether disulfonate, and the like.

  The content of the anionic surfactant A in the colorant dispersion is such that the colorant is effectively dispersed in the colorant dispersion and the amount of the monovalent and divalent anionic surfactants in the mixed dispersion is present. Is within the range described below, it is not particularly limited, and is usually 0.1 to 20% by weight, particularly 1 to 15% by weight, more preferably 3 to 10% by weight, based on the total amount of the colorant dispersion. As long as the object of the present invention is achieved, the present invention does not prevent the monovalent and divalent surfactants A from being used in combination. In that case, those total contents should just be in the said range.

  The anionic surfactant B contained in the mixed dispersion system at the time of aggregation / fusion can be any method as long as the amount of the monovalent and divalent anionic surfactants in the mixed dispersion system is within the range described below. May be supplied by For example, a method of supplying the anionic surfactant B by newly adding to the mixed dispersion system may be adopted, or a resin fine particle dispersion, a colorant dispersion, and / or other toner components to be mixed. A method of supplying the mixed dispersion system by adding an anionic surfactant B to the particle dispersion in advance or a combination of these methods may be employed. From the viewpoint of maintaining the pigment dispersibility in the toner, a method of supplying the anionic surfactant B by newly adding the anionic surfactant B to the mixed dispersion system is preferably employed.

  The anionic surfactant B has a valence different from that of the anionic surfactant A, and the anionic surfactant B may further contain the same valence as the anionic surfactant A. That is, when the anionic surfactant A is a monovalent anionic surfactant among the above, the anionic surfactant B is the divalent anionic surfactant, and the monovalent and divalent surfactants. A combination of anionic surfactants may also be used. When the anionic surfactant A is a divalent anionic surfactant among the above, the anionic surfactant B is the monovalent anionic surfactant, and the monovalent and divalent anions A combination of functional surfactants may be used. When a monovalent and divalent anionic surfactant is used in combination as the anionic surfactant A, the anionic surfactant B may be either a monovalent or divalent anionic surfactant, or A combination thereof may also be used.

The content of the anionic surfactant B in the mixed dispersion system is such a value that the amount of the monovalent and divalent anionic surfactants in the mixed dispersion system falls within the following range. When the monovalent and divalent surfactants are used in combination as the anionic surfactant B, the amount of the monovalent and divalent anionic surfactants in the mixed dispersion system falls within the following range. Contained.
Abundance of monovalent anionic surfactant: 0.1% by weight or more, particularly 1 to 15% by weight, preferably 2 to 10% by weight based on the total amount of the mixed dispersion system;
The amount of divalent anionic surfactant present: 0.1% by weight or more, particularly 0.5 to 10% by weight, preferably 1 to 8% by weight, based on the total amount of the mixed dispersion.

If the amount of the monovalent anionic surfactant is too small, the resin fine particles are hardly stabilized, so that the aggregation speed of the resin fine particles and the colorant particles cannot be effectively approximated, and the dispersibility of the colorant is low. descend. Moreover, aggregation of latex cannot be stabilized. On the other hand, even if the abundance is too much, the effect obtained is almost the same, and the manufacturing cost increases.
When the amount of the divalent anionic surfactant is too small, the resin fine particles are excessively stabilized and preferential aggregation of the colorant particles occurs, so that the dispersibility of the colorant is lowered. On the other hand, even if the abundance is too large, the obtained effect is hardly changed, and there is a side effect when the environmental fluctuation of the charging property of the toner becomes large, and the manufacturing cost increases.

  Aggregation in the mixed dispersion containing the surfactant is caused by salting out. The salting-out is described in detail in, for example, literature and books on colloids, published by Polymer Publishing Co., Ltd., Soichi Muroi, “Chemistry of Polymer Latex”, Chapter 6 and later. The electric double layer of dispersed particles is compressed to aggregate the particles.

  Examples of the flocculant used in the present invention include polar functional groups of resin fine particles, surfactants having a polarity opposite to the surfactant used in the resin fine particle dispersion and colorant particle dispersion, and divalent or higher inorganic metals. A salt can be suitably used. In general, the higher the valence, the greater the cohesive force. Therefore, the coagulant is selected in consideration of the particle aggregation speed and the stability of the production process in this step.

  Specific examples of the flocculant are illustrated. For example, monovalent metal salts such as sodium chloride, potassium chloride, lithium chloride, divalent metal salts such as calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, calcium nitrate, barium chloride, magnesium chloride, chloride Examples thereof include trivalent metal salts such as aluminum, iron chloride, and aluminum sulfate, and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide.

  These flocculants are preferably added in an amount equal to or higher than the critical aggregation concentration. The critical flocculation concentration is an index related to the stability of the dispersion in the mixed dispersion system, and indicates the addition concentration of the flocculating agent when the flocculating agent is added and flocculation occurs. This critical coagulation concentration varies greatly depending on the latex itself and the dispersant. For example, it is described in Seizo Okamura et al., Polymer Chemistry 17,601 (1960), etc., and the value can be known by following these descriptions. As another method, a desired salt is added to the target particle dispersion at a different concentration, the ζ potential of the dispersion is measured, and the salt concentration at the point where the ζ potential begins to change is defined as the critical aggregation concentration. It is also possible to do.

  In adding the flocculant, it is generally preferable to keep the temperature of the mixed dispersion system at 40 ° C. or lower from the viewpoint of suppressing abrupt aggregation in the mixed dispersion system. If the flocculant is added under conditions where the temperature exceeds 40 ° C., rapid agglomeration occurs, which may make it difficult to control the particle size, and the bulk density of the obtained particles may be problematic. Thereafter, the mixture is heated to produce aggregated particles. Stirring may be carried out in a reaction tank having a conventional well-known stirrer such as a paddle wing, squid wing, three retreat wings, Max blend wing, double helical, etc., or a homogenizer, homomixer, Henschel mixer, etc. are used. You can also. The number of rotations of stirring is preferably set so that the system is in a turbulent state.

  The particle size growth by the salting-out reaction is carried out until toner particles having substantially the same size as the toner particles are obtained, but can be controlled relatively easily by adjusting the pH and temperature of the dispersion. . Although the pH value varies depending on the zeta potential and isoelectric point of the reaction system, the type / amount of coagulant used, the type / amount of surfactant, and the target toner particle size, it cannot be uniquely defined. For example, when an aluminum-based flocculant is used, the pH at which the salting-out effect is effectively expressed is 2 to 6, and in the case of a magnesium-based flocculant, the pH is 7 to 12.

Similarly to pH, the reaction temperature cannot be uniquely defined, but it is preferable that the reaction temperature be in the range of 40 to 95 ° C. so that the particle size growth can be controlled. A temperature higher than this range is not preferable because the shape tends to be almost spherical due to the simultaneous progress of aggregation and fusion and lacks shape controllability. The reaction is held at a predetermined temperature for at least 10 minutes or more, more preferably 20 minutes or more to obtain toner particles having a desired particle diameter. If the reaction temperature is lower than the Tg of the resin, the particles only agglomerate and the fusion does not proceed. If the reaction temperature is higher than the Tg, the aggregation and fusion of the particles proceed simultaneously. If the fusion does not proceed in this step, the fusion is performed by raising the temperature at the end of this step.
In this step, the temperature may be increased at a constant rate up to a predetermined temperature, or may be increased stepwise. You may adjust suitably the rotation speed of the stirring blade of a system.

  The particle agglomeration speed and particle size control can be controlled by operating the reaction temperature and the number of revolutions of stirring while monitoring the agglomeration state of the particles in the system with a microscope or particle size measuring instrument until the desired particle size is reached. Do. When the desired particle size is reached, an operation of reducing the cohesive force may be performed in order to stop the growth of the particle size of the system or slow down the growth rate.

  As a means for reducing the cohesive force of the system, a means for increasing the stability of the particles or a means for reducing the coagulant action of the coagulant can be used. For example, as a means for increasing the stability of the particles, the pH of the system A method of adjusting to the stable side (for example, adjusting from neutral to alkaline when coagulating under acidic conditions, adjusting from neutral to acidic when coagulating under alkaline conditions) or the above-described surfactant (monovalent or divalent) Or anionic surfactant) is used. In addition, as a means for reducing the aggregating action of the aggregating agent, metal cations having different valences can be added, and the aggregating force can be remarkably reduced by an antagonistic action. It is possible to increase the temperature after reducing the cohesive force to promote fusion or control the shape to the spherical side. The shape of the particles can be monitored at any time by a shape measuring device FPIA-2000 (manufactured by Sysmex Corporation). The shape of the toner particles obtained as described above can be controlled by adjusting the heating conditions in the aging process of the salting-out / fusion process. A preferable average circularity of the toner particles is 0.930 or more, particularly 0.950 to 0.990.

  In the present invention, various inorganic pigments and organic pigments can be used as the colorant. A conventionally well-known thing can be used as an inorganic pigment. Any inorganic pigment can be used, but suitable inorganic pigments are exemplified below. For example, carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used. These inorganic pigments can be used alone or in combination as required.

  A conventionally well-known thing can be used as an organic pigment. Although any organic pigment can be used, specific organic pigments are exemplified below. Magenta or red pigments include CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 48: 1 CI Pigment Red 53: 1, CI Pigment Red 57: 1, CI Pigment Red 81: 3, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 139, CI Pigment Red 144, CI Pigment Red 149, CI Pigment Red 166, CI Pigment Red 177, CI Pigment Red 178, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 222, CI Pigment Red 238, and the like.

The pigments for orange or yellow include CI Pigment Orange 31, CI Pigment Orange 43, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 17, CI Pigment Yellow 74, CI CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 97, CI Pigment Yellow 138, CI Pigment Yellow 180, and the like.
Examples of the pigment for green or cyan include CI pigment blue 15, CI pigment blue 15: 2, CI pigment blue 15: 3, CI pigment blue 16, CI pigment blue 60, CI pigment green 7, and the like.

  In particular, the effect of the present invention becomes more remarkable when carbon black, which is difficult to produce toner by the aggregation / fusion method under high pigment filling, is used.

  The amount of the colorant used is not particularly limited as long as uniform dispersion in the toner particles is achieved, and may be adjusted so as to obtain the desired image transmission density. Usually, the amount in the toner particles is 2 to 20 parts by weight, preferably 3 to 15 parts by weight with respect to 100 parts by weight of the binder resin. When black toner is used as the magnetic toner, it is preferable that 20 to 60% by weight of the colorant content is replaced with magnetic powder.

  The toner particles constituting the toner of the present invention may contain a wax. As described above, when the wax dispersion is added to and mixed with the mixed dispersion system and the wax particles are aggregated / fused together with the resin fine particles, a method for producing the wax dispersion is, for example, published in March 1995 by the Polymer Society of Japan. As described in the Reaction Engineering Research Report-1 “Emulsification / Dispersion Technology and Particle Size Control of Polymer Fine Particles, Chapter 3”, any conventionally known method using an emulsification / dispersion device can be used. it can. The wax dispersion preferably has a dispersed particle size of 1 μm or less, more preferably in the range of 100 to 500 nm.

  As the wax, various known ones can be exemplified. Specific examples include olefin waxes such as polypropylene and polyethylene, modified products of these olefin waxes, natural waxes such as carnauba wax and rice wax, amide waxes such as fatty acid bisamides, and paraffin waxes. .

As a suitable wax constituting the toner of the present invention, the following general formula:
^{R 21 - (OCO-R 22} ) p
(Wherein R ²¹ and R ²² each represents a hydrocarbon group having 1 to 40 carbon atoms which may have a substituent, and p is an integer of 1 to 4). Can be mentioned which are composed of a water-soluble ester compound (hereinafter referred to as “specific ester compound”).

In the general formula showing a specific ester compound, R ²¹ and R ²² each represents a hydrocarbon group which may have a substituent. The hydrocarbon group R ²¹ has 1 to 40 carbon atoms, preferably 1 to 20 carbon atoms, more preferably 2 to 5 carbon atoms. The hydrocarbon group R ²² has 1 to 40 carbon atoms, preferably 16 to 30, and more preferably 18 to 26 carbon atoms. In the above general formula, p is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, particularly preferably 4.
The specific ester compound can be suitably synthesized by a dehydration condensation reaction between an alcohol and a carboxylic acid.

  Specific examples of the specific ester compound include the compounds (1w) to (22w) shown below.

  Among these waxes, a wax having a melting point of 100 ° C. or lower is more preferable for improving fixability, and a more preferable wax has a melting point in the range of 40 to 100 ° C., particularly preferably in the range of 60 to 90 ° C. It is. When the melting point exceeds 100 ° C., the effect of reducing the fixing temperature is poor. The wax dispersion used in the present invention is obtained by emulsification in the presence of at least one surfactant selected from the above surfactants. Two or more surfactants may be used in combination.

  As the charge control agent, any known one can be used alone or in combination. In consideration of color toner adaptability (the charge control agent itself is colorless or light color and there is no color tone hindrance to the toner), the quaternary ammonium salt compound is positively charged, the negative charge is salicylic acid or alkylsalicylic acid chromium, Metal salts with zinc, aluminum and the like, metal complexes, metal salts of benzylic acid, metal complexes, amide compounds, phenol compounds, naphthol compounds, phenolamide compounds, calixarene compounds and the like are preferable. For example, these charge control agents can be made into an emulsified dispersion using at least one selected from the above surfactants, and can be contained in the toner in the same manner as the above colorants and waxes.

(3) A filtration / washing process in which the toner particles are filtered off from the toner particle dispersion (aqueous medium) and the surfactant is removed from the toner particles;
In this filtration / washing step, a filtration treatment for filtering the toner particles from the dispersion of toner particles obtained in the above step, and a surfactant and agglomeration from the filtered toner particles (cake-like aggregate) are performed. And a cleaning process for removing deposits such as an agent.
Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using Nutsche or the like, a filtration method using a filter press or the like.

  A conventionally known cleaning method is used as a means for cleaning the filtered toner particles, such as a method of reslurrying and stirring the filtered toner particles with pure water in a container equipped with a stirring device, or vacuum filtration. Alternatively, a method such as applying pure water during centrifugal filtration is used. Further, at this time, in order to elute / remove the surfactant and metal salts remaining in the toner, an acidic or alkaline treatment may be performed before washing with pure water.

However, in the present invention, the anionic surfactants A and B are used as described above, and these surfactants cannot be completely removed even if the filtration / washing treatment as described above is performed. The toner of the present invention contains monovalent and divalent anionic surfactants. That is, the toner of the present invention contains monovalent and divalent anionic surfactants in the proportions shown below;
Monovalent anionic surfactant; 1.0% by weight or less, particularly 0.5% by weight or less of the total toner;
Divalent anionic surfactant; 1.0% by weight or less, particularly 0.5% by weight or less of the total toner.

  The content of monovalent and divalent anionic surfactants in the toner of the present invention can be measured by high performance liquid chromatography.

(4) a drying step of drying the washed toner particles;
This step is a step of drying the washed toner particles. Examples of dryers used in this process include spray dryers, vacuum freeze dryers, vacuum dryers, etc., stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers It is preferable to use a stirring dryer or the like. The moisture content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

  In addition, when the toner particles that have been dried are aggregated due to weak interparticle attraction, the aggregate may be crushed. Here, as the crushing treatment apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(5) A step of adding and treating an external additive to the toner particles obtained by drying;
This step is a step of obtaining a toner by adding a single or plural kinds of external additives to the dried toner particles. Examples of the apparatus used for adding the external additive include various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer. In addition, when a plurality of types of external additives are added in the step of the external addition treatment, all the additives may be mixed at a time or may be divided and mixed. After the mixing treatment, it is desirable to remove coarse particles from the obtained toner with a sieve having an opening of about 30 to 200 μm.

  It is preferable to add various organic / inorganic fine particles as external additives. As 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, diamond carbon lactam, etc. Various nitrides such as boron nitride, titanium nitride and zirconium nitride, borides such as zirconium boride, oxides, titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica, colloidal silica, etc. Various oxides, various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and carbon fluoride, aluminum stearate, calcium stearate Zinc stearate, various metal soaps such as magnesium stearate, talc, various non-magnetic inorganic fine particles of bentonite can be used alone or in combination. Especially for inorganic fine particles such as silica, titanium oxide, alumina, and zinc oxide, conventionally used hydrophobizing agents such as silane coupling agents, titanate coupling agents, silicone oils, and silicone varnishes, and fluorine-based ones. It is preferable that the surface treatment is carried out by a known method with a treatment agent such as a silane coupling agent, a fluorine-based silicone oil, a coupling agent having an amino group or a quaternary ammonium base, or a modified silicone oil.

The toner of the present invention preferably has the following physical properties in addition to achieving the acid value and image density described above.
The loose apparent density of the toner of the present invention is 0.30 to 0.45 g / cm ³ , preferably 0.33 to 0.42 g / cm ³ , and the particle size is preferably 3 to 9 μm in volume average particle size, more preferably 3 ˜7 μm. In the toner production method, the particle size can be controlled by the concentration of the flocculant, the amount of the organic solvent added, the aggregation / fusion time, and the polymer composition.

The volume average particle diameter of the toner is measured with a Coulter Counter TA-II or Coulter Multisizer II (Beckman Coulter, Inc.). In the present invention, a Coulter Multisizer II is used, and an interface (Beckman Coulter, Inc.) that outputs a particle size distribution and a personal computer are connected. A 50 μm aperture was used in the Coulter Multisizer II, and a toner volume distribution of 0.99 μm or more (for example, 2 to 40 μm) was measured to calculate a particle size distribution and an average particle size.
[Measurement conditions] (1) Aperture: 50 μm (2) Sample preparation method: Electrolyte [ISOTON-II-pc (manufactured by Beckman Coulter)] Add an appropriate amount of surfactant (neutral detergent) to 50-100 ml and stir To this, 10-20 mg of a measurement sample is added. This system is prepared by dispersing for 1 minute with an ultrasonic disperser.

As the shape of the toner particles of the present invention, the average circularity (average circularity represented by the following formula) is preferably 0.930 to 0.990, more preferably 0.950 to 0.980.
Circularity = (circle circumference obtained from equivalent circle diameter) / (perimeter of particle projection image)

Further, it is preferable that the circularity distribution is sharp, the standard deviation of circularity is preferably 0.10 or less, and the CV value calculated by the following formula is preferably 30% or less, particularly preferably 25% or less. More preferably, it is less than 20%, More preferably, it is less than 10%.
CV value = (standard deviation of circularity / average circularity) x 100
By setting the standard deviation of the circularity to 0.10 or less, it is possible to obtain a toner having a uniform shape, and it is possible to reduce the difference in the stress resistance and the cleaning property at the regulating portion between the toners. In addition, by setting the CV value in the above range, a sharp shape distribution can be obtained in the same manner, and the above effects can be exhibited more remarkably.

  The method for measuring the average circularity is not limited. For example, a photograph in which toner particles are magnified 500 times with an electron microscope is taken, and the circularity is measured for 500 or more toners using an image analyzer. The average circularity can be calculated by obtaining the arithmetic average value. Moreover, as a simple measuring method, it can be measured by “FPIA-2000” (manufactured by Sysmex Corporation).

  The toner of the present invention preferably has a softening point in the range of 70 to 150 ° C, more preferably 80 to 130 ° C, and still more preferably 85 to 120 ° C.

The softening point (Tm) of the resin or toner is a value measured by the following method.
Using a flow tester (CFT-500: manufactured by Shimadzu Corporation), weigh 1.0 g of the sample to be measured, and use a h1.0 mm x φ1.0 mm die, heating rate 3.0 ° C / min, preheating time 180 seconds, Measurement was performed under conditions of a load of 30 kg and a measurement temperature range of 60 to 160 ° C., and the temperature at which the above sample flowed out 1/2 was defined as a resin softening point (Tm).

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this. In the text, “part” means “part by mass”.

(Colorant dispersion K1)
210 g of sodium n-dodecyl sulfate was dissolved in 3290 ml of ion exchange water with stirring. While stirring this solution, 500 g of carbon black “Mogal L” (Cabot Corporation) was gradually added, and then dispersed by using “Cleamix” (M Technique Co., Ltd.) to give a color. A dispersion of agent particles (hereinafter referred to as “colorant dispersion K1”) was prepared. The particle diameter of the colorant particles in this colorant dispersion K1 was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), and the weight average particle diameter was 105 nm.

(Colorant dispersion K2)
185 g of disodium dodecyl diphenyl ether disulfonate was stirred and dissolved in 3315 ml of ion-exchanged water. While stirring this solution, 500 g of carbon black “Mogal L” (Cabot Corporation) is gradually added, and then dispersed by using “Cleamix” (M Technique Co., Ltd.) to give a color. A dispersion of agent particles (hereinafter referred to as “colorant dispersion K2”) was prepared. The particle diameter of the colorant particles in this colorant dispersion K2 was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), and the weight average particle diameter was 130 nm.

(Colorant dispersion K3)
370 g of disodium dodecyl diphenyl ether disulfonate was stirred and dissolved in 3130 ml of ion-exchanged water. While stirring this solution, 500 g of carbon black “Mogal L” (Cabot Corporation) is gradually added, and then dispersed by using “Cleamix” (M Technique Co., Ltd.) to give a color. A dispersion of agent particles (hereinafter referred to as “colorant dispersion K3”) was prepared. When the particle diameter of the colorant particles in this colorant dispersion K3 was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the weight average particle diameter was 120 nm.

(Colorant dispersion C1, M1, Y1)
In the same manner as the colorant dispersion K1, except that instead of carbon black, copper phthalocyanine Pigment Blue 15:30 (cyan pigment), Pigment Red 122 (magenta pigment) or CI Pigment Yellow 74 (yellow pigment) was used. Colorant dispersions C1, M1, and Y1 were prepared. The weight average particle diameter of the colorant particles was as follows.
Colorant dispersion C1; 200 nm
Colorant dispersion M1; 230 nm
Colorant dispersion Y1; 210nm

(Colorant dispersion C2, M2, Y2)
Disperse the colorant in the same way as the colorant dispersion K2, except that the same pigment as C1, M1, Y1 is used, and the medialess dispersion device CLEAR-SS5 (M Technique Co., Ltd.) is used as the dispersion device. Liquids C2, M2, and Y2 were prepared. The weight average particle diameter of the colorant particles was as follows.
Colorant dispersion C2; 170 nm
Colorant dispersion M2; 190nm
Colorant dispersion Y2; 180nm

(Colorant dispersion C3, M3, Y3)
Colorant dispersions C3, M3, and Y3 were prepared in the same manner as the colorant dispersion K3, except that the same pigments as C1, M1, and Y1 were used. The weight average particle diameter of the colorant particles was as follows.
Colorant dispersion C3; 200 nm
Colorant dispersion M3; 210 nm
Colorant dispersion Y3; 190nm

(Preparation of latex 1HML)
(1) Preparation of core particles (first stage polymerization):
The following dispersion medium 1 was charged into a 5000 ml separable flask equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introduction device, and the temperature in the flask was raised to 80 ° C while stirring at a stirring speed of 230 rpm under a nitrogen stream. Allowed to warm.
(Dispersion medium 1)
Sodium dodecyl sulfate 4.05g
Ion exchange water 2500.00g
(Monomer solution 1)
Styrene 568.00g
n-Butyl acrylate 164.00g
Methacrylic acid 68.00g
n-octyl mercaptan 16.51 g
To this activator solution, an initiator solution prepared by dissolving 9.62 g of a polymerization initiator (potassium persulfate) in 200 g of ion-exchanged water was added, and the monomer solution was added dropwise over 90 minutes. Polymerization (first stage polymerization) was carried out by heating and stirring at 2 ° C. for 2 hours to prepare a latex. This is called “latex (1H)”. The weight average particle diameter of the latex (1H) was 68 nm.

(2) Formation of intermediate layer (second stage polymerization):
(Monomer solution 2)
Styrene 123.81g
n-Butyl acrylate 39.51g
Methacrylic acid 12.29g
n-octyl mercaptan 0.72 g
WEP-5 (manufactured by NOF Corporation) 93.80g
In a flask equipped with a stirrer, the above monomer solution 2 was charged, and heated to 80 ° C. and dissolved to prepare a monomer solution.
(Dispersion medium 2)
C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na 0.60 g
Ion exchange water 2700.00g
On the other hand, after the dispersion medium 2 is heated to 98 ° C. and 32 g of the latex (1H), which is a dispersion medium of core particles, is added to the dispersion medium in terms of solid content, a machine having a circulation path is added to the dispersion liquid. Dispersion (emulsion) containing emulsified particles (oil droplets) was prepared by mixing and dispersing the monomer solution 2 for 8 hours using a type disperser “CLEARMIX” (M Technique Co., Ltd.). .

  Next, an initiator solution prepared by dissolving 6.12 g of a polymerization initiator (potassium persulfate) in 250 ml of ion-exchanged water is added to this dispersion (emulsion), and the system is heated and stirred at 82 ° C. for 12 hours. Thus, polymerization (second stage polymerization) was performed to obtain latex (a dispersion of composite resin particles having a structure in which the surface of latex (1H) particles was coated). This is called “latex (1HM)”.

(3) Formation of outer layer (third stage polymerization):
An initiator solution obtained by dissolving 8.8 g of a polymerization initiator (KPS) in 350 ml of ion-exchanged water was added to the latex (1HM) obtained as described above, and the simple solution shown in Table 1 was obtained under a temperature condition of 82 ° C. A solution obtained by adding 1.0 mol% of n-octyl mercaptan to monomer solution 3-1 and stirring uniformly was added dropwise over 1 hour. After completion of the dropping, polymerization (third stage polymerization) is carried out by heating and stirring for 2 hours, followed by cooling to 28 ° C. and latex (center part made of latex (1H) and intermediate layer made of second stage polymer resin) And an outer layer made of a third-stage polymerization resin, and a dispersion of a composite resin in which WEP-5 is contained in the second-stage polymerization resin layer). This latex is referred to as “latex (1HML)”.

(Preparation of latex 2HML and 3HML)
Prepare latex in the same manner as latex 1HML, except that the monomer solution 3-1 during the third stage polymerization is changed to the monomer solution 3-2 or 3-3 in Table 1, and latex (2HML) and latex respectively. (3HML) was obtained.

Experimental Example 1 (Black toner )
(Toner particle 1)
250.0 g of latex (1HML) (converted to solid content), 1000 g of ion-exchanged water, 150 g of colorant dispersion K1, and 3.6 g of disodium dodecyl diphenyl ether disulfonate as a surfactant, temperature sensor, cooling pipe, nitrogen introduction It stirred in the reaction container (four-necked flask) which attached the apparatus and the stirring apparatus. After adjusting the temperature in the container to 30 ° C., 5N aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0.

  Next, an aqueous solution prepared by dissolving 53 g of magnesium chloride hexahydrate in 10 ml of ion-exchanged water was added at 30 ° C. over 10 minutes with stirring. After standing for 3 minutes, the temperature was raised to 92 ° C. to produce aggregated particles. In that state, the particle size of the aggregated particles was measured with “Coulter Counter TA-II”. When the number average particle size reached 6.2 μm, an aqueous solution in which 80 g of sodium chloride was dissolved in 1000 ml of ion-exchanged water was added. Then, the particle growth was stopped and the mixture was further heated and stirred as a ripening treatment at a liquid temperature of 94 ° C. to continue particle fusion and phase separation of the crystalline substance (ripening step). In this state, the shape of the fused particles was measured with “FPIA-2000”. When the shape factor reached 0.960, the mixture was cooled to 30 ° C., and stirring was stopped. The produced fused particles were filtered, repeatedly washed with ion exchanged water at 45 ° C., and then dried with hot air at 40 ° C. to obtain toner particles 1.

(Toner particles 2 to 10)
Except for changing the latex to be used, the colorant dispersion, the surfactant and the amount thereof as described in Table 2, the same operation as in the toner particle 1 was performed to obtain toner particles 2 to 10, respectively. . In the production of toner particles 10, no surfactant was added.

(Manufacture of toner)
Hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68) is added to each obtained toner particle at a ratio of 1.0% by mass, and hydrophobic titanium oxide (number average primary particle size = 20 nm). The degree of hydrophobicity = 63) was added at a ratio of 1.2% by mass, and the mixture was mixed with a Henschel mixer to produce a toner. The shape and particle size of the toner particles were not changed by the addition of hydrophobic silica and hydrophobic titanium oxide.

(Toner evaluation)
<Acid value>
Dissolve 10 mg of sample in 50 ml of toluene and remove the colorant with a 0.1 μm membrane filter. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titrated with a standardized N / 10 potassium hydroxide / alcohol solution, and calculated from the consumption of N / 10 potassium hydroxide / alcohol solution. is there.

<Hygroscopic resistance>
The sample is dried in a vacuum dryer for 24 hours in advance and then conditioned in a high-temperature and high-humidity environment (30 ° C, 80%) for 24 hours, and the moisture content is measured with a Karl Fischer moisture meter.
○: Moisture content is 1.5% or less;
Δ: Moisture content is less than 2.0%;
X: Water content is 2.0% or more.

<Image density>
As an evaluation machine, a modified machine of magicolor 2300 DL (manufactured by Minolta EMS) modified so that a printed image can be output without using a fixing device was used, and the following evaluation was performed.
Using the machine connected to the personal computer, the belt-like unfixed solid image is output to CF80 paper (manufactured by Minolta Co., Ltd.) while gradually changing the density. A part of the obtained solid image is removed by suction, and the adhesion amount of each image is calculated from the removed area and the removed toner amount. This image is passed through a fixing tester (set temperature 180 ° C.) composed only of the fixing unit of the magicolor 2300 DL, and the density of the obtained fixed image is measured with a transmission densitometer (manufactured by Macbeth). . An image density of 4.0 g / m ² was calculated from the image density of each adhesion amount.
Black toner A: Image density is 1.4 or more;
○: Image density is 1.2 or more;
X: The image density is less than 1.2.
Cyan toner, magenta toner, and yellow toner A: The image density is 1.0 or more;
○: Image density is 0.9 or more;
X: The image density is less than 0.9.

<Durability test with actual machine (chargeability)>
The chargeability was evaluated by measuring the charge amount as follows.
Using magicolor 2300DL, a Y / M / C / K C / W ratio was 5%. A total of 4 colors and 20% images were continuously tested for 4,500 sheets. The toner charge amount of the developing roller at this time was measured by a suction method. Here, the suction method is a method in which the charged toner on the developing roller is sucked, and the charge amount is measured from the toner weight peeled off from the developing roller and the moving charge amount measured by an electrometer.

<Evaluation results>
In Examples 1A to 6A, good results were obtained for all the evaluation items.
In Comparative Example 1A, aggregation of only carbon black occurred, the dispersibility deteriorated, and the image density and chargeability became poor. In Comparative Example 2 A, the aggregation speed could not be controlled and the agglomeration was felt, the dispersibility was deteriorated, and the image density and the chargeability were poor. In Comparative Example 3 A, since a latex having a high acid value was used, the hygroscopicity was deteriorated, resulting in poor charging in a low temperature and low humidity environment. In Comparative Example 4A, rapid aggregation occurred, making it impossible to control the particle size (shape). Dispersibility deteriorated, data reproducibility could not be obtained in the measurement of acid value and the like, and toner particles that could be actually evaluated could not be obtained.
As described above, according to the present invention, a toner having good carbon black dispersibility and low hygroscopicity was obtained.

Experiment 2 (Cyan toner )
Except for changing the latex to be used, the colorant dispersion, the surfactant and the amount thereof as described in Table 4, the same operation as in the toner particle 1 was performed to obtain toner particles 11 to 20, respectively. . In the production of the toner particles 20, no surfactant was added.

A toner was obtained in the same manner as in Experimental Example 1, and the toner was evaluated.

Experiment 3 (Magenta toner )
Except for changing the latex to be used, the colorant dispersion, the surfactant and the amount thereof as described in Table 6, the same operation as in the toner particle 1 was performed to obtain toner particles 21 to 30, respectively. . In the production of toner particles 30, no surfactant was added.

A toner was obtained in the same manner as in Experimental Example 1, and the toner was evaluated.

Experiment 4 (yellow toner )
Except for changing the latex to be used, the colorant dispersion, the surfactant and the amount thereof as described in Table 8, the same operation as in the toner particle 1 was performed to obtain toner particles 31 to 40, respectively. . In the production of the toner particles 40, no surfactant was added.

A toner was obtained in the same manner as in Experimental Example 1, and the toner was evaluated.

Claims (6)

It comprises toner particles obtained by agglomerating / fusing at least binder resin fine particles and a colorant in an aqueous medium, the toner has an acid value of 10 mg · KOH / g or less, and a toner adhesion amount of 4 g / m ² A full-color toner for developing an electrostatic charge image, wherein the image transmission density (TD) is 1.2 or more when black toner, and 0.9 or more when cyan toner, magenta toner and yellow toner.   The full-color toner for developing electrostatic images according to claim 1, comprising monovalent and divalent anionic surfactants. The monovalent anionic surfactant is of the general formula;
_{^{(R 6 -O-SO 3)}} - n · M n + (III)
(Wherein R ⁶ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms; M ^{n +} is a monovalent or divalent metal ion or an ammonium ion; n is 1 or 2) An alkyl monosulfate ester salt represented by:
A divalent anionic surfactant is a general formula;

Or

(In Formula (VII) and Formula (VIII), R ¹¹ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms; X ⁺ is a monovalent metal ion or ammonium ion; Y ²⁺ is 2 The full-color toner for developing an electrostatic charge image according to claim 2, wherein the toner is an alkyl diphenyl ether disulfonate represented by the formula:   A method for producing a full-color toner for developing an electrostatic image, wherein at least a binder resin fine particle dispersion and a colorant dispersion are mixed, and the particles are aggregated / fused to form toner particles. The anionic surfactant A is contained, and the anionic surfactant B having a valence different from that of the anionic surfactant A is contained in the mixed dispersion system at the time of aggregation / fusion. A method for producing a full-color toner for developing electrostatic images according to any one of 1 to 3.   5. The anionic surfactant A is one surfactant of a monovalent or divalent anionic surfactant, and the anionic surfactant B is the other surfactant. A method for producing a full-color toner for developing an electrostatic charge image according to claim 1. The monovalent anionic surfactant is of the general formula;
_{^{(R 6 -O-SO 3)}} - n · M n + (III)
(Wherein R ⁶ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms; M ^{n +} is a monovalent or divalent metal ion or an ammonium ion; n is 1 or 2) An alkyl monosulfate ester salt represented by:
A divalent anionic surfactant is a general formula;

Or

(In Formula (VII) and Formula (VIII), R ¹¹ is a monovalent aliphatic saturated hydrocarbon group having 8 to 20 carbon atoms; X ⁺ is a monovalent metal ion or ammonium ion; Y ²⁺ is 2 6. The method for producing a full-color toner for developing an electrostatic charge image according to claim 5, wherein the alkyl diphenyl ether disulfonate is represented by a valent metal ion.